WorldWideScience

Sample records for urban expressway network

  1. STUDY ON SUPPORTING FOR DRAWING UP THE BCP FOR URBAN EXPRESSWAY NETWORK USING BY TRAFFIC SIMULATION SYSTEM

    Science.gov (United States)

    Yamawaki, Masashi; Shiraki, Wataru; Inomo, Hitoshi; Yasuda, Keiichi

    The urban expressway network is an important infrastructure to execute a disaster restoration. Therefore, it is necessary to draw up the BCP (Business Continuity Plan) to enable securing of road user's safety and restoration of facilities, etc. It is important that each urban expressway manager execute decision and improvement of effective BCP countermeasures when disaster occurs by assuming various disaster situations. Then, in this study, we develop the traffic simulation system that can reproduce various disaster situations and traffic actions, and examine some methods supporting for drawing up the BCP for an urban expressway network. For disaster outside assumption such as tsunami generated by a huge earthquake, we examine some approaches securing safety of users and cars on the Hanshin Expressway Network as well as on general roads. And, we aim to propose a tsunami countermeasure not considered in the current urban expressway BCP.

  2. Variable speed limit strategies analysis with link transmission model on urban expressway

    Science.gov (United States)

    Li, Shubin; Cao, Danni

    2018-02-01

    The variable speed limit (VSL) is a kind of active traffic management method. Most of the strategies are used in the expressway traffic flow control in order to ensure traffic safety. However, the urban expressway system is the main artery, carrying most traffic pressure. It has similar traffic characteristics with the expressways between cities. In this paper, the improved link transmission model (LTM) combined with VSL strategies is proposed, based on the urban expressway network. The model can simulate the movement of the vehicles and the shock wave, and well balance the relationship between the amount of calculation and accuracy. Furthermore, the optimal VSL strategy can be proposed based on the simulation method. It can provide management strategies for managers. Finally, a simple example is given to illustrate the model and method. The selected indexes are the average density, the average speed and the average flow on the traffic network in the simulation. The simulation results show that the proposed model and method are feasible. The VSL strategy can effectively alleviate traffic congestion in some cases, and greatly promote the efficiency of the transportation system.

  3. A Real-time Breakdown Prediction Method for Urban Expressway On-ramp Bottlenecks

    Science.gov (United States)

    Ye, Yingjun; Qin, Guoyang; Sun, Jian; Liu, Qiyuan

    2018-01-01

    Breakdown occurrence on expressway is considered to relate with various factors. Therefore, to investigate the association between breakdowns and these factors, a Bayesian network (BN) model is adopted in this paper. Based on the breakdown events identified at 10 urban expressways on-ramp in Shanghai, China, 23 parameters before breakdowns are extracted, including dynamic environment conditions aggregated with 5-minutes and static geometry features. Different time periods data are used to predict breakdown. Results indicate that the models using 5-10 min data prior to breakdown performs the best prediction, with the prediction accuracies higher than 73%. Moreover, one unified model for all bottlenecks is also built and shows reasonably good prediction performance with the classification accuracy of breakdowns about 75%, at best. Additionally, to simplify the model parameter input, the random forests (RF) model is adopted to identify the key variables. Modeling with the selected 7 parameters, the refined BN model can predict breakdown with adequate accuracy.

  4. Traffic Multiresolution Modeling and Consistency Analysis of Urban Expressway Based on Asynchronous Integration Strategy

    Directory of Open Access Journals (Sweden)

    Liyan Zhang

    2017-01-01

    Full Text Available The paper studies multiresolution traffic flow simulation model of urban expressway. Firstly, compared with two-level hybrid model, three-level multiresolution hybrid model has been chosen. Then, multiresolution simulation framework and integration strategies are introduced. Thirdly, the paper proposes an urban expressway multiresolution traffic simulation model by asynchronous integration strategy based on Set Theory, which includes three submodels: macromodel, mesomodel, and micromodel. After that, the applicable conditions and derivation process of the three submodels are discussed in detail. In addition, in order to simulate and evaluate the multiresolution model, “simple simulation scenario” of North-South Elevated Expressway in Shanghai has been established. The simulation results showed the following. (1 Volume-density relationships of three submodels are unanimous with detector data. (2 When traffic density is high, macromodel has a high precision and smaller error and the dispersion of results is smaller. Compared with macromodel, simulation accuracies of micromodel and mesomodel are lower but errors are bigger. (3 Multiresolution model can simulate characteristics of traffic flow, capture traffic wave, and keep the consistency of traffic state transition. Finally, the results showed that the novel multiresolution model can have higher simulation accuracy and it is feasible and effective in the real traffic simulation scenario.

  5. On the Effects of Central Japan Expressway's Commuter Toll Discount Policy in Nagoya Area

    Institute of Scientific and Technical Information of China (English)

    YING Jiangqian; Ryosuke Ando

    2007-01-01

    Road pricing policies have two equally important objectives that have to be considered: the optimal use of the road network and the fiscal sustainability for the management of the network. The aim of this work is to examine the effects on these two objectives of a recent pricing policy implemented in Japan's expressway networks. Recently the Nippon (Japan) Expressway Companies (NEXCO, operators of Japan's nation wide expressway network) have implemented several toll discount policies for users equipped with electronic toll collectors (ETCs). One of the policies is the commuter discount policy that discounts 50% for a journey on the NEXCO expressway no longer than 100 km during the commuting peak hours. This paper examines its effect on congestion reduction in the road network of Nagoya area and its influence on the use of expressways operated by another major local public expressway company in Nagoya. The congestion easing effect of this policy is compared with a potential marginal cost pricing scheme. These observations suggest that policy coordination regarding toll levels is needed for expressway corporations and transportation authorities for improving transportation efficiency of utilization of the whole network.

  6. Consumer preferences relative to the price and network capability of small urban vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Burns, L.D.

    1979-09-01

    Preferences of consumers for small urban vehicle concepts differing only with respect to their hypothetical purchase prices and network capabilities (i.e., whether they are capable of operating on expressways, major arterials, or local streets) are analyzed using statistical techniques based on psychological scaling theories. Results from these analyses indicate that a vast majority of consumers are not readily willing to give up the accessibility provided by conventional automobiles. More specifically, over the range of hypothetical prices considered here, network capability dominates as a determinant of preferences for vehicle concepts. Also, the ability to operate vehicles on expressways is of utmost importance to consumers.

  7. Impacts of Snowy Weather Conditions on Expressway Traffic Flow Characteristics

    Directory of Open Access Journals (Sweden)

    Jiancheng Weng

    2013-01-01

    Full Text Available Snowy weather will significantly degrade expressway operations, reduce service levels, and increase driving difficulty. Furthermore, the impact of snow varies in different types of roads, diverse cities, and snow densities due to different driving behavior. Traffic flow parameters are essential to decide what should be appropriate for weather-related traffic management and control strategies. This paper takes Beijing as a case study and analyzes traffic flow data collected by detectors in expressways. By comparing the performance of traffic flow under normal and snowy weather conditions, this paper quantitatively describes the impact of adverse weather on expressway volume and average speeds. Results indicate that average speeds on the Beijing expressway under heavy snow conditions decrease by 10–20 km/h when compared to those under normal weather conditions, the vehicle headway generally increases by 2–4 seconds, and the road capacity drops by about 33%. This paper also develops a specific expressway traffic parameter reduction model which proposes reduction coefficients of expressway volumes and speeds under various snow density conditions in Beijing. The conclusions paper provide effective foundational parameters for urban expressway controls and traffic management under snow conditions.

  8. Case studies: Application of SEA in provincial level expressway infrastructure network planning in China - Current existing problems

    International Nuclear Information System (INIS)

    Zhou Kaiyi; Sheate, William R.

    2011-01-01

    Since the Law of the People's Republic of China on Environmental Impact Assessment was enacted in 2003 and Huanfa 2004 No. 98 was released in 2004, Strategic Environmental Assessment (SEA) has been officially being implemented in the expressway infrastructure planning field in China. Through scrutinizing two SEA application cases of China's provincial level expressway infrastructure (PLEI) network plans, it is found that current SEA practice in expressway infrastructure planning field has a number of problems including: SEA practitioners do not fully understand the objective of SEA; its potential contributions to strategic planning and decision-making is extremely limited; the employed application procedure and prediction and assessment techniques are too simple to bring objective, unbiased and scientific results; and no alternative options are considered. All these problems directly lead to poor quality SEA and consequently weaken SEA's effectiveness.

  9. EIA application in China's expressway infrastructure: clarifying the decision-making hierarchy.

    Science.gov (United States)

    Zhou, Kai-Yi; Sheate, William R

    2011-06-01

    China's EIA Law came into effect in 2003 and formally requires road transport infrastructure development actions to be subject to Environmental Impact Assessment (EIA). EIAs (including project EIA and plan EIA, or strategic environmental impact assessment, SEA) have been being widely applied in the expressway infrastructure planning field. Among those applications, SEA is applied to provincial level expressway network (PLEI) plans, and project EIA is applied to expressway infrastructure development 'projects' under PLEI plans. Three case studies (one expressway project EIA and two PLEI plan SEAs) were examined to understand currently how EIAs are applied to expressway infrastructure development planning. Through the studies, a number of problems that significantly influence the quality of EIA application in the field were identified. The reasons causing those problems are analyzed and possible solutions are suggested aimed at enhancing EIA practice, helping deliver better decision-making and ultimately improving the environmental performance of expressway infrastructure. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. A real-time crash prediction model for the ramp vicinities of urban expressways

    Directory of Open Access Journals (Sweden)

    Moinul Hossain

    2013-07-01

    Full Text Available Ramp vicinities are arguably the known black-spots on urban expressways. There, while maintaining high speed, drivers need to respond to several complex events such as maneuvering, reading road signs, route planning and maintaining safe distance from other maneuvering vehicles simultaneously which demand higher level of cognitive response to ensure safety. Therefore, any additional discomfort caused by traffic dynamics may induce driving error resulting in a crash. This manuscript presents a methodology for identifying these dynamically forming hazardous traffic conditions near the ramp vicinities with high resolution real-time traffic flow data. It separates the ramp vicinities into four zones – upstream and downstream of entrance and exit ramps, and builds four separate real-time crash prediction models. Around two year (December 2007 to October 2009 crash data as well as their matching traffic sensor data from Shibuya 3 and Shinjuku 4 expressways under the jurisdiction of Tokyo Metropolitan Expressway Company Limited have been utilized for this research. Random multinomial logit, a forest of multinomial logit models, has been used to identify the most important variables. Finally, a real-time modeling method, Bayesian belief net (BBN, has been employed to build the four models using ramp flow, flow and congestion index in the upstream and flow and speed in the downstream of the ramp location as variables. The newly proposed models could predict 50%, 42%, 43% and 55% of the future crashes with around 10% false alarm for the downstream of entrance, downstream of exit, upstream of entrance and upstream of exit ramps respectively. The models can be utilized in combination with various traffic smoothing measures such as ramp metering, variable speed limit, warning messages through variable message signs, etc. to enhance safety near the ramp vicinities.

  11. A Simplified Approach to Estimate the Urban Expressway Capacity after Traffic Accidents Using a Micro-Simulation Model

    Directory of Open Access Journals (Sweden)

    Hong Chen

    2013-01-01

    Full Text Available Based on the decomposition of the evolution processes of the urban expressway capacity after traffic accidents and the influence factors analysis, an approach for estimating the capacity has been proposed. Firstly, the approach introduces the Decision Tree ID algorithm, solves the accident delay time of different accident types by the Information Gain Value, and determines congestion dissipation time by the Traffic Flow Wave Theory. Secondly, taking the accident delay time as the observation cycle, the maximum number of the vehicles through the accident road per unit time was considered as its capacity. Finally, the attenuation simulation of the capacity for different accident types was calculated by the VISSIM software. The simulation results suggest that capacity attenuation of vehicle anchor is minimal and the rate is 30.074%; the next is vehicles fire, rear-end, and roll-over, and the rate is 38.389%, 40.204%, and 43.130%, respectively; the capacity attenuation of vehicle collision is the largest, and the rate is 50.037%. Moreover, the further research shows that the accident delay time is proportional to congestion dissipation time, time difference, and the ratio between them, but it is an inverse relationship with the residual capacity of urban expressway.

  12. Properties of Phase Transition of Traffic Flow on Urban Expressway Systems with Ramps and Accessory Roads

    International Nuclear Information System (INIS)

    Mei Chaoqun; Liu Yejin

    2011-01-01

    In this paper, we develop a cellular automaton model to describe the phase transition of traffic flow on urban expressway systems with on-off-ramps and accessory roads. The lane changing rules are given in detailed, the numerical results show that the main road and the accessory road both produce phase transitions. These phase transitions will often be influenced by the number of lanes, lane changing, the ramp flow, the input flow rate, and the geometry structure. (interdisciplinary physics and related areas of science and technology)

  13. An analysis of roadway noise at residential estates in close proximity to expressways in Singapore

    Directory of Open Access Journals (Sweden)

    Indraneel Bhanap

    2013-01-01

    Full Text Available Singapore is a city-state of 5 million people. The entire urban population has expanded from 4.4 million to 5 million in a matter of 5 years. Because of the scarcity of land available, more major roads and expressways are being run close to residential developments, exposing the residents to expressway noise. Recognizing the problems of noise in a high-density urban society such as Singapore, the National Environmental Agency of Singapore (NEA has set prescribed noise limits for residential areas. The purpose of this paper is to analyze the noise level in one such development that is adjacent to an expressway, examine the effect of building height on noise and to compare the results with the NEA standards. The paper concludes with the implications of the results and a discussion on the solution to the problem.

  14. Traffic accidents on expressways: new threat to China.

    Science.gov (United States)

    Zhao, Jinbao; Deng, Wei

    2012-01-01

    As China is building one of the largest expressway systems in the world, expressway safety problems have become serious concerns to China. This article analyzed the trends in expressway accidents in China from 1995 to 2010 and examined the characteristics of these accidents. Expressway accident data were obtained from the Annual Report for Road Traffic Accidents published by the Ministry of Public Security of China. Expressway mileage data were obtained from the National Statistics Yearbook published by the National Bureau of Statistics of China. Descriptive statistical analyses were conducted based on these data. Expressway deaths increased by 10.2-fold from 616 persons in 1995 to 6300 persons in 2010, and the average annual increase was 17.9 percent over the past 15 years, and the overall other road traffic deaths was -0.33 percent. China's expressway mileage accounted for only 1.85 percent of highway mileage driven in 2010, but expressway deaths made up 13.54 percent of highway traffic deaths. The average annual accident lethality rate [accident deaths/(accident deaths + accident injuries)] for China's expressways was 27.76 percent during the period 1995 to 2010, which was 1.33 times higher than the accident lethality rate of highway traffic accidents. China's government should pay attention to expressway construction and safety interventions during the rapid development period of expressways. Related causes, such as geographic patterns, speeding, weather conditions, and traffic flow composition, need to be studied in the near future. An effective and scientific expressway safety management services system, composed of a speed monitoring system, warning system, and emergency rescue system, should be established in developed and underdeveloped provinces in China to improve safety on expressway.

  15. Spatial equity analysis on expressway network development in Japan: Empirical approach using the spatial computable general equilibrium model RAEM-light

    NARCIS (Netherlands)

    Koike, A.; Tavasszy, L.; Sato, K.

    2009-01-01

    The authors apply the RAEM-Light model to analyze the distribution of social benefits from expressway network projects from the viewpoint of spatial equity. The RAEM-Light model has some innovative features. The spatial behavior of producers and consumers is explicitly described and is endogenously

  16. A Bayesian network based framework for real-time crash prediction on the basic freeway segments of urban expressways.

    Science.gov (United States)

    Hossain, Moinul; Muromachi, Yasunori

    2012-03-01

    The concept of measuring the crash risk for a very short time window in near future is gaining more practicality due to the recent advancements in the fields of information systems and traffic sensor technology. Although some real-time crash prediction models have already been proposed, they are still primitive in nature and require substantial improvements to be implemented in real-life. This manuscript investigates the major shortcomings of the existing models and offers solutions to overcome them with an improved framework and modeling method. It employs random multinomial logit model to identify the most important predictors as well as the most suitable detector locations to acquire data to build such a model. Afterwards, it applies Bayesian belief net (BBN) to build the real-time crash prediction model. The model has been constructed using high resolution detector data collected from Shibuya 3 and Shinjuku 4 expressways under the jurisdiction of Tokyo Metropolitan Expressway Company Limited, Japan. It has been specifically built for the basic freeway segments and it predicts the chance of formation of a hazardous traffic condition within the next 4-9 min for a particular 250 meter long road section. The performance evaluation results reflect that at an average threshold value the model is able to successful classify 66% of the future crashes with a false alarm rate less than 20%. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Drivers' Visual Characteristics when Merging onto or Exiting an Urban Expressway.

    Directory of Open Access Journals (Sweden)

    Ying Cheng

    Full Text Available The aim of this study is to examine drivers' visual and driving behavior while merging onto or exiting an urban expressway with low and high traffic densities. The analysis was conducted according to three periods (approaching, merging or exiting, and accelerating or decelerating. A total of 10 subjects (8 males and 2 females with ages ranging from 25 to 52 years old (M = 30.0 years old participated in the study. The research was conducted in a natural driving situation, and the drivers' eye movements were monitored and recorded using an eye tracking system. The results show that the influence of traffic density on the glance duration and scan duration is more significant when merging than when exiting. The results also demonstrate that the number of glances and the mean glance duration are mainly related to the driving task (e.g., the merging period. Therefore, drivers' visual search strategies mainly depend on the current driving task. With regard to driving behavior, the variation tendencies of the duration and the velocity of each period are similar. These results support building an automated driving assistant system that can automatically identify gaps and accelerate or decelerate the car accordingly or provide suggestions to the driver to do so.

  18. Marginal Congestion Cost on a Dynamic Expressway Network

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Small, Kenneth A.

    2012-01-01

    a dynamic econometric model using unusually complete and accurate data from Danish motorways. We use the results to estimate the marginal external cost of adding a vehicle to a link's entry flow, finding it is highly influenced by the dynamic properties of the system of relationships between travel times......We formulate an empirical model of congestion for a series of sequential expressway links where queues may form and spill back. Its purpose is to disentangle the dynamic effect that a marginal vehicle has on the distribution of travel times experienced there and on connected links. We estimate...

  19. A Density-Based Ramp Metering Model Considering Multilane Context in Urban Expressways

    Directory of Open Access Journals (Sweden)

    Li Tang

    2017-01-01

    Full Text Available As one of the most effective intelligent transportation strategies, ramp metering is regularly discussed and applied all over the world. The classic ramp metering algorithm ALINEA dominates in practical applications due to its advantages in stabilizing traffic flow at a high throughput level. Although ALINEA chooses the traffic occupancy as the optimization parameter, the classic traffic flow variables (density, traffic volume, and travel speed may be easier obtained and understood by operators in practice. This paper presents a density-based ramp metering model for multilane context (MDB-RM on urban expressways. The field data of traffic flow parameters is collected in Chengdu, China. A dynamic density model for multilane condition is developed. An error function represented by multilane dynamic density is introduced to adjust the different usage between lanes. By minimizing the error function, the density of mainstream traffic can stabilize at the set value, while realizing the maximum decrease of on-ramp queues. Also, VISSIM Component Object Model of Application Programming Interface is used for comparison of the MDB-RM model with a noncontrol, ALINEA, and density-based model, respectively. The simulation results indicate that the MDB-RM model is capable of achieving a comprehensive optimal result from both sides of the mainstream and on-ramp.

  20. The impact of selected planned motorways and expressways on the potential accessibility of the Polish-Slovak borderland with respect to tourism development

    Directory of Open Access Journals (Sweden)

    Michniak Daniel

    2015-03-01

    Full Text Available Further tourism development in the Polish-Slovak borderland, as well as its overall economic development, depends on the construction of a motorway and expressway network. This paper analyses the impact of selected planned motorways and expressways (D1, A4, D3/S69, R1/R3/S7, and R4/S19 on the potential accessibility of the Polish-Slovak borderland with respect to the development of tourism. The most important investment project in Slovakia is the completion of the (started D1 motorway. The R4/S19 and the R1/R3/S7 expressways and the D3 motorway/S69 expressway are expected to contribute to improved cross-border connections.

  1. Expressway deformation mapping using high-resolution TerraSAR-X images

    KAUST Repository

    Shi, Xuguo

    2014-01-27

    Monitoring deformation of linear infrastructures such as expressway and railway caused by natural processes or anthropogenic activities is a vital task to ensure the safety of human lives and properties. Interferometric Synthetic Aperture Radar (InSAR) has been widely recognized as an effective technology to carry out large-area surface deformation mapping. However, its application in linear infrastructure deformation monitoring has not been intensively studied till now. In this article, a modified Small BAseline Subset (SBAS) method is proposed to retrieve the deformation patterns of the expressway. In our method, only the point-like targets identified on the expressway were kept in our analysis, and two complementary subsets of interferograms were formed to better separate the signals of height error and deformation from inteferometric phase observations. We successfully applied this method with multitemporal high-resolution TerraSAR-X images to retrieve the spatialoral pattern of surface deformation along the Beian-Heihe expressway that is located in island-permafrost areas and threatened by geohazards. © 2014 Taylor & Francis.

  2. Expressway deformation mapping using high-resolution TerraSAR-X images

    KAUST Repository

    Shi, Xuguo; Liao, Mingsheng; Wang, Teng; Zhang, Lu; Shan, Wei; Wang, Chunjiao

    2014-01-01

    Monitoring deformation of linear infrastructures such as expressway and railway caused by natural processes or anthropogenic activities is a vital task to ensure the safety of human lives and properties. Interferometric Synthetic Aperture Radar (InSAR) has been widely recognized as an effective technology to carry out large-area surface deformation mapping. However, its application in linear infrastructure deformation monitoring has not been intensively studied till now. In this article, a modified Small BAseline Subset (SBAS) method is proposed to retrieve the deformation patterns of the expressway. In our method, only the point-like targets identified on the expressway were kept in our analysis, and two complementary subsets of interferograms were formed to better separate the signals of height error and deformation from inteferometric phase observations. We successfully applied this method with multitemporal high-resolution TerraSAR-X images to retrieve the spatialoral pattern of surface deformation along the Beian-Heihe expressway that is located in island-permafrost areas and threatened by geohazards. © 2014 Taylor & Francis.

  3. Rural expressway intersection safety toolbox : desktop reference.

    Science.gov (United States)

    2011-06-01

    This document is intended to be a guide for planning-level decisions concerning safety : issues and subsequent potential improvements at rural expressway intersections. It is : NOT a design guide. It simply presents the gamut of safety treatment opti...

  4. Swift fox survey along Heartland Expressway Corridor.

    Science.gov (United States)

    2015-05-01

    The swift fox (Vulpes velox) is a small canid classified as endangered within the : state of Nebraska. Future construction of the Heartland Expressway Corridor (HEC), a : 300 km road expansion project in the panhandle of the state, may impact the res...

  5. ANALYSIS ON THE INFLUENCE OF ACCUMULATION EFFECT OF LANDSCAPE COLOR ON TRAFFIC SAFETY IN THE FOGGY SECTIONS OF EXPRESSWAYS

    OpenAIRE

    Xilei Li; Boming Tang; Qianghui Song

    2017-01-01

    The landscape color of expressways has a significant impact on a driver's visual response, thus affecting the incidence of expressways traffic accidents. Although this problem has been analyzed and discussed from different angles, there is rare quantitative analysis on the influence of accumulation effect of landscape color on the traffic safety in foggy sections of expressways. In this paper, the color combination and stroboflash of fog lamps on both sides of the road were designed from the ...

  6. Stability Analysis of Landslide on the R1 Expressway by Limit Equilibrium and Finite Element Methods

    Science.gov (United States)

    Janták, Viktor

    2017-12-01

    The most difficult problem by designing the superior infrastructure is tracing the expressways and higways in an environment of Quaternary and Neogene complexes of finegrained cohesive and non-cohesive soils. At the last time the typical examples are stability problems on the R1 Nitra - Tekovské Nemce Expressway. The article is focused on the description of reasons of stability loss in the deep earth cut in the 79,000 km of expressway R1, the course of the landslide, slide correction and especially slope-stability assessment before and after the occurrence of slope failures by limit equilibrium and finite elements methods by comparing the behaviour of the slope in the various model situations.

  7. Pollution level assessment of road dust from islamabad expressway

    International Nuclear Information System (INIS)

    Faiz, Y.; Siddiqui, N.

    2013-01-01

    Thirteen road dust and four soil samples were analyzed using Instrumental Neutron Activation Analysis (INAA) and Flame Atomic Absorption Spectroscopy (FAAS) to determine the elemental composition of road dust collected from Islamabad Expressway. Pollution parameters and indicators such as Enrichment Factors (EFs), Pollution Load Index (PLI), Geoaccumulation Index (I G eo), Pollution Index (PI) and Integrated Pollution Index (IPI) were calculated and showed that the area around Islamabad Expressway is low to moderately polluted especially by elements such as Mg and Sb. The IPI of the elements was found to vary in the order; Mg>Sb>Cu>Sr ≅Pb>Ga>Na >Sn≅ Zn>Yb>Se>Hf. The 5 samples collected around the busy intersections of Faizabad and Zero Point have higher amounts of most of the elements determined. Moreover the pollution indices for these samples indicate that these sites are more contaminated than the remaining 8 sampling sites. (author)

  8. Urban Green Network Design: Defining green network from an urban planning perspective

    OpenAIRE

    Andrea Tulisi

    2017-01-01

    From the theoretical context of Smart City various studies have emerged that adopt an analytical approach and description of urban phenomena based on the principles of “network design”; this line of research uses the network systems theory to define the principles that regulate the relationships among the various elements of urban sub-systems in order to optimize their functionality. From the same theoretical basis, urban greenspaces have also been studied as networks, by means of the creatio...

  9. Urban Green Network Design: Defining green network from an urban planning perspective

    Directory of Open Access Journals (Sweden)

    Andrea Tulisi

    2017-08-01

    Full Text Available From the theoretical context of Smart City various studies have emerged that adopt an analytical approach and description of urban phenomena based on the principles of “network design”; this line of research uses the network systems theory to define the principles that regulate the relationships among the various elements of urban sub-systems in order to optimize their functionality. From the same theoretical basis, urban greenspaces have also been studied as networks, by means of the creation of models capable of measuring the performance of the system in its entirety, posing the basis of a new multy-disciplinary research field called green network. This paper presents the results of research aimed at clarifying the meaning of green network from an urban planning perspective through a lexical analysis applied to a textual corpus of more than 300 abstracts of research papers that have dealt with this topic over the last twenty years. The results show that the concept of green network appears still fuzzy and unclear, due to the different meaning given to the term “green” and to an incorrect use of the term “network”, often referred to as a generic set of natural areas present in a city, without any reference to the network system theory or to the basic rules linking these elements together. For this reason, the paper proposes a unique definition of green network from an urban planning perspective that takes into account the contribution of other research areas to effective green infrastructure planning. This is the concept of “urban green network design” defined as “an urban planning practice, supported by decision support tools able to model green infrastructure as network, composed by natural and semi-natural areas, whose connections are modelled according to specific variables, in order to deliver an equal distribution of public services for enhancing the quality of life as well as a wide range of ecosystem services”.

  10. APPLICATION OF TRAVEL TIME RELIABILITY FOR PERFORMANCE ORIENTED OPERATIONAL PLANNING OF EXPRESSWAYS

    Science.gov (United States)

    Mehran, Babak; Nakamura, Hideki

    Evaluation of impacts of congestion improvement scheme s on travel time reliability is very significant for road authorities since travel time reliability repr esents operational performance of expressway segments. In this paper, a methodology is presented to estimate travel tim e reliability prior to implementation of congestion relief schemes based on travel time variation modeling as a function of demand, capacity, weather conditions and road accident s. For subject expressway segmen ts, traffic conditions are modeled over a whole year considering demand and capacity as random variables. Patterns of demand and capacity are generated for each five minute interval by appl ying Monte-Carlo simulation technique, and accidents are randomly generated based on a model that links acci dent rate to traffic conditions. A whole year analysis is performed by comparing de mand and available capacity for each scenario and queue length is estimated through shockwave analysis for each time in terval. Travel times are estimated from refined speed-flow relationships developed for intercity expressways and buffer time index is estimated consequently as a measure of travel time reliability. For validation, estimated reliability indices are compared with measured values from empirical data, and it is shown that the proposed method is suitable for operational evaluation and planning purposes.

  11. Effects of Lane Width, Lane Position and Edge Shoulder Width on Driving Behavior in Underground Urban Expressways: A Driving Simulator Study

    Directory of Open Access Journals (Sweden)

    Shuo Liu

    2016-10-01

    Full Text Available This study tested the effects of lane width, lane position and edge shoulder width on driving behavior for a three-lane underground urban expressway. A driving simulator was used with 24 volunteer test subjects. Five lane widths (2.85, 3.00, 3.25, 3.50, and 3.75 m and three shoulder widths (0.50, 0.75, and 1.00 m were studied. Driving speed, lane deviation and subjective perception of driving behavior were collected as performance measures. The results show that lane and shoulder width have significant effects on driving speed. Average driving speed increases from 60.01 km/h in the narrowest lane to 88.05 km/h in the widest lane. While both narrower lanes and shoulders result in reduced speed and lateral lane deviation, the effect of lane width is greater than that of shoulder width. When the lane and shoulder are narrow, drivers in the left or right lane tend to shy away from the tunnel wall, even encroaching into the neighboring middle lane. As the lane or shoulder gets wider, drivers tend to stay in the middle of the lane. An interesting finding is that although few participants acknowledged that lane position had any great bearing on their driving behaviors, the observed driving speed is statistically higher in the left lane than in the other two lanes when the lane width is narrow (in 2.85, 3 and 3.25 m lanes. These findings provided support for amending the current design specifications of urban underground roads, such as the relationship between design speed and lane width, speed limit, and combination form of lanes.

  12. Origin and destination survey results for the Orlando-Orange County Expressway Authority

    Science.gov (United States)

    2000-09-01

    This report describes the design, administration, and analysis of the Origin/Destination survey of users of the Orlando-Orange County Expressway System. The basic survey form consisted of a letter-sized paper with the questionnaire on one side and a ...

  13. Urban Networking vs. Smart City

    Directory of Open Access Journals (Sweden)

    Păuna Carmen Beatrice

    2017-04-01

    Full Text Available Taking into consideration that the development of strong partnerships involving local citizens, civil society, the local economy and the various levels of government is an indispensable element for an Integrated Sustainable Urban Development, our paper is focusing on the role of an appropriate urban networking in the relationship with the objectives of a smart city. In this context, the Romanian good practices - as Oradea city - are worth to mention. In compliance with Europe 2020 Strategy’s objectives there will be discussed the particularities of urban networking in order to strengthen the resilience of cities, and to ensure synergies amongst the investments supported by European Structural and Investment (ESI funds. According to economic literature the urban network is not a funding instrument but a way for cities to share feedback on the use of these new approaches. The estimated results of our research are related to the conclusion that the urban networks act as a forum for capacity building and exchange between the cities pioneering new techniques and developing integrated investments.

  14. Level and Contamination Assessment of Soil along an Expressway in an Ecologically Valuable Area in Central Poland.

    Science.gov (United States)

    Radziemska, Maja; Fronczyk, Joanna

    2015-10-23

    Express roads are a potential source of heavy metal contamination in the surrounding environment. The Warsaw Expressway (E30) is one of the busiest roads in the capital of Poland and cuts through the ecologically valuable area (Mazowiecki Natural Landscape Park). Soil samples were collected at distances of 0.5, 4.5 and 25 m from the expressway. The concentrations of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) were determined in the soils by the flame atomic absorption spectrometry method (FAAS). Soils located in the direct proximity of the analyzed stretch of road were found to have the highest values of pH and electrical conductivity (EC), which decreased along with an increase in the distance from the expressway. The contents of Cd, Cu and Zn were found to be higher than Polish national averages, whereas the average values of Ni and Pb were not exceeded. The pollution level was estimated based on the geo-accumulation index (Igeo), and the pollution index (PI). The results of Igeo and PI indexes revealed the following orders: Cu zinc, lead and cadmium.

  15. Landslide susceptibility mapping along PLUS expressways in Malaysia using probabilistic based model in GIS

    Science.gov (United States)

    Yusof, Norbazlan M.; Pradhan, Biswajeet

    2014-06-01

    PLUS Berhad holds the concession for a total of 987 km of toll expressways in Malaysia, the longest of which is the North-South Expressway or NSE. Acting as the backbone' of the west coast of the peninsula, the NSE stretches from the Malaysian-Thai border in the north to the border with neighbouring Singapore in the south, linking several major cities and towns along the way. North-South Expressway in Malaysia contributes to the country economic development through trade, social and tourism sector. Presently, the highway is good in terms of its condition and connection to every state but some locations need urgent attention. Stability of slopes at these locations is of most concern as any instability can cause danger to the motorist. In this paper, two study locations have been analysed; they are Gua Tempurung (soil slope) and Jelapang (rock slope) which are obviously having two different characteristics. These locations passed through undulating terrain with steep slopes where landslides are common and the probability of slope instability due to human activities in surrounding areas is high. A combination of twelve (12) landslide conditioning factors database on slope stability such as slope degree and slope aspect were extracted from IFSAR (interoferometric synthetic aperture radar) while landuse, lithology and structural geology were constructed from interpretation of high resolution satellite data from World View II, Quickbird and Ikonos. All this information was analysed in geographic information system (GIS) environment for landslide susceptibility mapping using probabilistic based frequency ratio model. Consequently, information on the slopes such as inventories, condition assessments and maintenance records were assessed through total expressway maintenance management system or better known as TEMAN. The above mentioned system is used by PLUS as an asset management and decision support tools for maintenance activities along the highways as well as for data

  16. Landslide susceptibility mapping along PLUS expressways in Malaysia using probabilistic based model in GIS

    International Nuclear Information System (INIS)

    Yusof, Norbazlan M; Pradhan, Biswajeet

    2014-01-01

    PLUS Berhad holds the concession for a total of 987 km of toll expressways in Malaysia, the longest of which is the North-South Expressway or NSE. Acting as the backbone' of the west coast of the peninsula, the NSE stretches from the Malaysian-Thai border in the north to the border with neighbouring Singapore in the south, linking several major cities and towns along the way. North-South Expressway in Malaysia contributes to the country economic development through trade, social and tourism sector. Presently, the highway is good in terms of its condition and connection to every state but some locations need urgent attention. Stability of slopes at these locations is of most concern as any instability can cause danger to the motorist. In this paper, two study locations have been analysed; they are Gua Tempurung (soil slope) and Jelapang (rock slope) which are obviously having two different characteristics. These locations passed through undulating terrain with steep slopes where landslides are common and the probability of slope instability due to human activities in surrounding areas is high. A combination of twelve (12) landslide conditioning factors database on slope stability such as slope degree and slope aspect were extracted from IFSAR (interoferometric synthetic aperture radar) while landuse, lithology and structural geology were constructed from interpretation of high resolution satellite data from World View II, Quickbird and Ikonos. All this information was analysed in geographic information system (GIS) environment for landslide susceptibility mapping using probabilistic based frequency ratio model. Consequently, information on the slopes such as inventories, condition assessments and maintenance records were assessed through total expressway maintenance management system or better known as TEMAN. The above mentioned system is used by PLUS as an asset management and decision support tools for maintenance activities along the highways as well as for

  17. Developing a Traffic Management Framework for Coastal Expressway Bridges under Adverse Weather Conditions: Case Study of Rain Day in Shenzhen, China

    Directory of Open Access Journals (Sweden)

    Chenming Jiang

    2015-01-01

    Full Text Available Adverse weather can reduce visibility and road surface friction, lower vehicle maneuverability, and increase crash frequency and injury severity. The impacts of adverse weather and its interactions with drivers and roadway on the operation and management of expressway or expressway bridges have drawn the researchers’ and managers’ attention to develop traffic management frameworks to mitigate the negative influence. Considering the peculiar geographical location and meteorological conditions, the Guangshen Coast Expressway-Shenzhen Segment (GSCE-SS was selected as a case in this study to illustrate the proposed traffic management framework on rain days. Conditions categorized by rainfall intensity and traffic flow were the main precondition to make the management decisions. CORSIM simulator was used to develop the alternate routes choice schemes, providing reference for other systems in the proposed traffic management framework. Maps of (a entrance ramp control (ERC strategies; (b mainline control strategies; (c alternate routes choice; (d information release schemes, under scenarios of different volume and rainstorm warning grades (BLUE to RED, were drawn to present a reference or demonstration for managers of long-span expressway bridges not only in China, but even in the world.

  18. Grid Mapping for Spatial Pattern Analyses of Recurrent Urban Traffic Congestion Based on Taxi GPS Sensing Data

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2017-03-01

    Full Text Available Traffic congestion is one of the most serious problems that impact urban transportation efficiency, especially in big cities. Identifying traffic congestion locations and occurring patterns is a prerequisite for urban transportation managers in order to take proper countermeasures for mitigating traffic congestion. In this study, the historical GPS sensing data of about 12,000 taxi floating cars in Beijing were used for pattern analyses of recurrent traffic congestion based on the grid mapping method. Through the use of ArcGIS software, 2D and 3D maps of the road network congestion were generated for traffic congestion pattern visualization. The study results showed that three types of traffic congestion patterns were identified, namely: point type, stemming from insufficient capacities at the nodes of the road network; line type, caused by high traffic demand or bottleneck issues in the road segments; and region type, resulting from multiple high-demand expressways merging and connecting to each other. The study illustrated that the proposed method would be effective for discovering traffic congestion locations and patterns and helpful for decision makers to take corresponding traffic engineering countermeasures in order to relieve the urban traffic congestion issues.

  19. Research on centrality of urban transport network nodes

    Science.gov (United States)

    Wang, Kui; Fu, Xiufen

    2017-05-01

    Based on the actual data of urban transport in Guangzhou, 19,150 bus stations in Guangzhou (as of 2014) are selected as nodes. Based on the theory of complex network, the network model of Guangzhou urban transport is constructed. By analyzing the degree centrality index, betweenness centrality index and closeness centrality index of nodes in the network, the level of centrality of each node in the network is studied. From a different point of view to determine the hub node of Guangzhou urban transport network, corresponding to the city's key sites and major transfer sites. The reliability of the network is determined by the stability of some key nodes (transport hub station). The research of network node centralization can provide a theoretical basis for the rational allocation of urban transport network sites and public transport system planning.

  20. Analysis of robustness of urban bus network

    Science.gov (United States)

    Tao, Ren; Yi-Fan, Wang; Miao-Miao, Liu; Yan-Jie, Xu

    2016-02-01

    In this paper, the invulnerability and cascade failures are discussed for the urban bus network. Firstly, three static models(bus stop network, bus transfer network, and bus line network) are used to analyse the structure and invulnerability of urban bus network in order to understand the features of bus network comprehensively. Secondly, a new way is proposed to study the invulnerability of urban bus network by modelling two layered networks, i.e., the bus stop-line network and the bus line-transfer network and then the interactions between different models are analysed. Finally, by modelling a new layered network which can reflect the dynamic passenger flows, the cascade failures are discussed. Then a new load redistribution method is proposed to study the robustness of dynamic traffic. In this paper, the bus network of Shenyang City which is one of the biggest cities in China, is taken as a simulation example. In addition, some suggestions are given to improve the urban bus network and provide emergency strategies when traffic congestion occurs according to the numerical simulation results. Project supported by the National Natural Science Foundation of China (Grant Nos. 61473073, 61374178, 61104074, and 61203329), the Fundamental Research Funds for the Central Universities (Grant Nos. N130417006, L1517004), and the Program for Liaoning Excellent Talents in University (Grant No. LJQ2014028).

  1. The Homogeneity Research of Urban Rail Transit Network Performance

    Directory of Open Access Journals (Sweden)

    Wang Fu-jian

    2016-01-01

    Full Text Available Urban Rail Transit is an important part of the public transit, it is necessary to carry out the corresponding network function analysis. Previous studies mainly about network performance analysis of a single city rail transit, lacking of horizontal comparison between the multi-city, it is difficult to find inner unity of different Urban Rail Transit network functions. Taking into account the Urban Rail Transit network is a typical complex networks, so this paper proposes the application of complex network theory to research the homogeneity of Urban Rail Transit network performance. This paper selects rail networks of Beijing, Shanghai, Guangzhou as calculation case, gave them a complex network mapping through the L, P Space method and had a static topological analysis using complex network theory, Network characteristics in three cities were calculated and analyzed form node degree distribution and node connection preference. Finally, this paper studied the network efficiency changes of Urban Rail Transit system under different attack mode. The results showed that, although rail transport network size, model construction and construction planning of the three cities are different, but their network performance in many aspects showed high homogeneity.

  2. Urban networks of tomorrow

    International Nuclear Information System (INIS)

    Bothe, D; Kaufmann, T.

    2016-01-01

    The requirements for urban utility grids are subject to a considerable change. The diversification of the energy supply and the changing feed-in structure (central -> decentral) also influence the operation of the existing networks considerably. Therefore, the focus of future studies will be on the flexibility of energy supply and the energy-carrier-wide network analysis or planning. These aspects are addressed, among other things, within the URBEM project, with a focus on a holistic, interdisciplinary approach. On the basis of separately performed thermal and electrical network calculations an optimization task is defined (for example, minimization of operating resources, minimization of CO2 emissions) and solved under technical conditions. The scenarios for the period 2030 and 2050 developed in the URBEM project serve as the basis for the optimization. The results of the calculations show current utilization or bottlenecks in the supply networks as well as optimum future supply structures for development areas in urban areas. (rössner) [de

  3. Level and Contamination Assessment of Soil along an Expressway in an Ecologically Valuable Area in Central Poland

    Directory of Open Access Journals (Sweden)

    Maja Radziemska

    2015-10-01

    Full Text Available Express roads are a potential source of heavy metal contamination in the surrounding environment. The Warsaw Expressway (E30 is one of the busiest roads in the capital of Poland and cuts through the ecologically valuable area (Mazowiecki Natural Landscape Park. Soil samples were collected at distances of 0.5, 4.5 and 25 m from the expressway. The concentrations of cadmium (Cd, copper (Cu, nickel (Ni, lead (Pb, and zinc (Zn were determined in the soils by the flame atomic absorption spectrometry method (FAAS. Soils located in the direct proximity of the analyzed stretch of road were found to have the highest values of pH and electrical conductivity (EC, which decreased along with an increase in the distance from the expressway. The contents of Cd, Cu and Zn were found to be higher than Polish national averages, whereas the average values of Ni and Pb were not exceeded. The pollution level was estimated based on the geo-accumulation index (Igeo, and the pollution index (PI. The results of Igeo and PI indexes revealed the following orders: Cu < Zn < Ni < Cd < Pb and Cu < Ni < Cd < Zn < Pb, and comparison with geochemical background values showed higher concentration of zinc, lead and cadmium.

  4. Mathematical Analysis of Urban Spatial Networks

    CERN Document Server

    Blanchard, Philippe

    2009-01-01

    Cities can be considered to be among the largest and most complex artificial networks created by human beings. Due to the numerous and diverse human-driven activities, urban network topology and dynamics can differ quite substantially from that of natural networks and so call for an alternative method of analysis. The intent of the present monograph is to lay down the theoretical foundations for studying the topology of compact urban patterns, using methods from spectral graph theory and statistical physics. These methods are demonstrated as tools to investigate the structure of a number of real cities with widely differing properties: medieval German cities, the webs of city canals in Amsterdam and Venice, and a modern urban structure such as found in Manhattan. Last but not least, the book concludes by providing a brief overview of possible applications that will eventually lead to a useful body of knowledge for architects, urban planners and civil engineers.

  5. ANALYSIS ON THE INFLUENCE OF ACCUMULATION EFFECT OF LANDSCAPE COLOR ON TRAFFIC SAFETY IN THE FOGGY SECTIONS OF EXPRESSWAYS

    Directory of Open Access Journals (Sweden)

    Xilei Li

    2017-10-01

    Full Text Available The landscape color of expressways has a significant impact on a driver's visual response, thus affecting the incidence of expressways traffic accidents. Although this problem has been analyzed and discussed from different angles, there is rare quantitative analysis on the influence of accumulation effect of landscape color on the traffic safety in foggy sections of expressways. In this paper, the color combination and stroboflash of fog lamps on both sides of the road were designed from the perspective of the color research of road landscapes, and the cumulative effect of colors and stroboflash of fog lamps on the drivers’ mind was also studied. Then the interactive cumulative model based on landscape color and driving time in heavy-fog environment was established. Finally, multi-group of fog-lamp colors and spacing experiment program allowing a visibility of 200–500m in fog environments was designed by using Tobii eye-movement instrument and the UC-win/Road simulation software. According to the program, simulations were performed on several drivers to test the influence of road-landscape colors in foggy environments on the drivers' visual psychology. The results of the simulation experiment showed that the colors and stroboflash of fog lamps on both sides of the road have a positive effect on the drivers’ safety when the visibility range is 200–500m, and the driving speed is less than 70 km/h, in addition, the red and yellow were found to have the largest influence among all the studied colors. These results show that it is necessary to design landscape colors in the foggy sections of expressways.

  6. Heuristic urban transportation network design method, a multilayer coevolution approach

    Science.gov (United States)

    Ding, Rui; Ujang, Norsidah; Hamid, Hussain bin; Manan, Mohd Shahrudin Abd; Li, Rong; Wu, Jianjun

    2017-08-01

    The design of urban transportation networks plays a key role in the urban planning process, and the coevolution of urban networks has recently garnered significant attention in literature. However, most of these recent articles are based on networks that are essentially planar. In this research, we propose a heuristic multilayer urban network coevolution model with lower layer network and upper layer network that are associated with growth and stimulate one another. We first use the relative neighbourhood graph and the Gabriel graph to simulate the structure of rail and road networks, respectively. With simulation we find that when a specific number of nodes are added, the total travel cost ratio between an expanded network and the initial lower layer network has the lowest value. The cooperation strength Λ and the changeable parameter average operation speed ratio Θ show that transit users' route choices change dramatically through the coevolution process and that their decisions, in turn, affect the multilayer network structure. We also note that the simulated relation between the Gini coefficient of the betweenness centrality, Θ and Λ have an optimal point for network design. This research could inspire the analysis of urban network topology features and the assessment of urban growth trends.

  7. Connected vehicle pilot deployment program phase I : security management operational concept, Tampa Hillsborough Expressway Authority (THEA).

    Science.gov (United States)

    2016-05-01

    The Tampa Hillsborough Expressway Authority (THEA) Connected Vehicle (CV) Pilot Deployment Program is intended to develop a suite of applications that utilize vehicle to infrastructure (V2I) and vehicle to vehicle (V2V) communication technology to re...

  8. Modeling urbanization patterns with generative adversarial networks

    OpenAIRE

    Albert, Adrian; Strano, Emanuele; Kaur, Jasleen; Gonzalez, Marta

    2018-01-01

    In this study we propose a new method to simulate hyper-realistic urban patterns using Generative Adversarial Networks trained with a global urban land-use inventory. We generated a synthetic urban "universe" that qualitatively reproduces the complex spatial organization observed in global urban patterns, while being able to quantitatively recover certain key high-level urban spatial metrics.

  9. Ecological networks in urban landscapes

    NARCIS (Netherlands)

    Cook, E.A.

    2000-01-01

    This research focuses on the topic of ecological networks in urban landscapes. Analysis and planning of ecological networks is a relatively new phenomenon and is a response to fragmentation and deterioration of quality of natural systems. In agricultural areas and with existing nature

  10. Measuring Shared Social Appreciation of Community Goods: An Experiment for the East Elevated Expressway of Rome

    Directory of Open Access Journals (Sweden)

    Saverio Miccoli

    2015-11-01

    Full Text Available Many large projects held over the last few decades in Europe have been based on the enhancement of community goods as a strategy to put in place sustainable urban regeneration. The inclusive nature of these goods and the social importance of the related decision-making processes suggests the need to involve the relevant community and to take into account its intentions and wishes regarding planning and organization. Therefore, before even starting to plan possible interventions, it is crucial to know what the members of the community think about the good in terms of social appreciation, in order to achieve socially sustainable choices. This paper offers a method to measure the social appreciation of community goods and describes the following: (a deliberative esteem value technology to measure the social appreciation based on a combination between stated preference techniques and deliberative methods; (b the criterion and methodology of the valuation technique proposed; and (c an experimental application of the valuation technique pertinent to the specific case of the East Elevated Expressway of Rome.

  11. Traffic supervisory/control system for Kobe-Awaji- Naruto expressway of Honshu-Shikoku Bridge Authority; Honshu Shikoku Renrakukyo Kodan nonyu no Kobe Awaji Naruto jidoshado kotsu kansei shisetsu seigyo system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Toshiba delivered the traffic supervisory/control system for Kobe-Awaji-Naruto expressway of Honshu-Shikoku Bridge Authority opened in May 1998. This traffic supervisory system rapidly exactly collects and services the information on the expressway of 89km including Akashi Kaikyo bridge and O-Naruto bridge. The facility control system totally efficiently maintains and controls various facilities for lighting and air circulation of tunnels on the expressway. The previous control system transmitted road information on traffic volume and traffic congestion to offices by using specific lines and terminals, while this system with a monitoring function using intranet can easily service such information by existing PCs. (translated by NEDO)

  12. Traffic supervisory/control system for Kobe-Awaji- Naruto expressway of Honshu-Shikoku Bridge Authority. Honshu Shikoku Renrakukyo Kodan nonyu no Kobe Awaji Naruto jidoshado kotsu kansei shisetsu seigyo system

    Energy Technology Data Exchange (ETDEWEB)

    1999-03-01

    Toshiba delivered the traffic supervisory/control system for Kobe-Awaji-Naruto expressway of Honshu-Shikoku Bridge Authority opened in May 1998. This traffic supervisory system rapidly exactly collects and services the information on the expressway of 89km including Akashi Kaikyo bridge and O-Naruto bridge. The facility control system totally efficiently maintains and controls various facilities for lighting and air circulation of tunnels on the expressway. The previous control system transmitted road information on traffic volume and traffic congestion to offices by using specific lines and terminals, while this system with a monitoring function using intranet can easily service such information by existing PCs. (translated by NEDO)

  13. Multilayered complex network datasets for three supply chain network archetypes on an urban road grid

    Directory of Open Access Journals (Sweden)

    Nadia M. Viljoen

    2018-02-01

    Full Text Available This article presents the multilayered complex network formulation for three different supply chain network archetypes on an urban road grid and describes how 500 instances were randomly generated for each archetype. Both the supply chain network layer and the urban road network layer are directed unweighted networks. The shortest path set is calculated for each of the 1 500 experimental instances. The datasets are used to empirically explore the impact that the supply chain's dependence on the transport network has on its vulnerability in Viljoen and Joubert (2017 [1]. The datasets are publicly available on Mendeley (Joubert and Viljoen, 2017 [2]. Keywords: Multilayered complex networks, Supply chain vulnerability, Urban road networks

  14. Study on the complex network characteristics of urban road system based on GIS

    Science.gov (United States)

    Gao, Zhonghua; Chen, Zhenjie; Liu, Yongxue; Huang, Kang

    2007-06-01

    Urban road system is the basic bone of urban transportation and one of the most important factors that influent and controls the urban configuration. In this paper, an approach of modeling, analyzing and optimizing urban road system is described based on complex network theory and GIS technology. The urban road system is studied on three focuses: building the urban road network, modeling the computational procedures based on urban road networks and analyzing the urban road system of Changzhou City as the study case. The conclusion is that the urban road network is a scale-free network with small-world characteristic, and there is still space for development of the whole network as a small-world network, also the key road crosses should be kept expedite.

  15. Urban Water Innovation Network (UWIN): Transitioning Toward Sustainbale Urban Water Systems

    Science.gov (United States)

    Arabi, M.

    2015-12-01

    City water systems are at risk of disruption from global social and environmental hazards, which could have deleterious effects on human health, property, and loss of critical infrastructure. The Urban Water Innovation Network (UWIN), a consortium of 14 academic institutions and other key partners across the U.S., is working to address challenges that threaten urban water systems across the nation. UWIN's mission is to create technological, institutional and management solutions to help communities increase the resilience of their water systems and enhance their preparedness for responding to water crisis. The network seeks solutions that achieve widespread adoption consistent with inclusive, equitable and sustainable urban development. The integrative and adaptive analysis framework of UWIN is presented. The framework identifies a toolbox of sustainable solutions by simultaneously minimizing pressures, enhancing resilience to extreme events, and maximizing cobenefits. The benefits of sustainable urban water solutions for linked urban ecosystems, economies, and arrangements for environmental justice and social equity, will be discussed. The network encompasses six U.S. regions with varying ecohydrologic and climatic regimes ranging from the coastal moist mid-latitude climates of the Mid-Atlantic to the subtropical semi-arid deserts of the Southwest. These regions also represent a wide spectrum of demographic, cultural, and policy settings. The opportunities for cross-site assessments that facilitate the exploration of locally appropriate solutions across regions undergoing various development trajectories will be discussed.

  16. CONSIDERING TRAVEL TIME RELIABILITY AND SAFETY FOR EVALUATION OF CONGESTION RELIEF SCHEMES ON EXPRESSWAY SEGMENTS

    Directory of Open Access Journals (Sweden)

    Babak MEHRAN

    2009-01-01

    Full Text Available Evaluation of the efficiency of congestion relief schemes on expressways has generally been based on average travel time analysis. However, road authorities are much more interested in knowing the possible impacts of improvement schemes on safety and travel time reliability prior to implementing them in real conditions. A methodology is presented to estimate travel time reliability based on modeling travel time variations as a function of demand, capacity and weather conditions. For a subject expressway segment, patterns of demand and capacity were generated for each 5-minute interval over a year by using the Monte-Carlo simulation technique, and accidents were generated randomly according to traffic conditions. A whole year analysis was performed by comparing demand and available capacity for each scenario and shockwave analysis was used to estimate the queue length at each time interval. Travel times were estimated from refined speed-flow relationships and buffer time index was estimated as a measure of travel time reliability. it was shown that the estimated reliability measures and predicted number of accidents are very close to observed values through empirical data. After validation, the methodology was applied to assess the impact of two alternative congestion relief schemes on a subject expressway segment. one alternative was to open the hard shoulder to traffic during the peak period, while the other was to reduce the peak period demand by 15%. The extent of improvements in travel conditions and safety, likewise the reduction in road users' costs after implementing each improvement scheme were estimated. it was shown that both strategies can result in up to 23% reduction in the number of occurred accidents and significant improvements in travel time reliability. Finally, the advantages and challenging issues of selecting each improvement scheme were discussed.

  17. Looking for Sustainable Urban Mobility through Bayesian Networks

    Directory of Open Access Journals (Sweden)

    Giovanni Fusco

    2004-11-01

    Full Text Available There is no formalised theory of sustainable urban mobility systems. Observed patterns of urban mobility are often considered unsustainable. But we don’t know what a city with sustainable mobility should look like. It is nevertheless increasingly apparent that the urban mobility system plays an important role in the achievement of the city’s wider sustainability objectives.In this paper we explore the characteristics of sustainable urban mobility systems through the technique of Bayesian networks. At the frontier between multivariate statistics and artificial intelligence, Bayesian networks provide powerful models of causal knowledge in an uncertain context. Using data on urban structure, transportation offer, mobility demand, resource consumption and environmental externalities from seventy-five world cities, we developed a systemic model of the city-transportation-environment interaction in the form of a Bayesian network. The network could then be used to infer the features of the city with sustainable mobility.The Bayesian model indicates that the city with sustainable mobility is most probably a dense city with highly efficient transit and multimodal mobility. It produces high levels of accessibility without relying on a fast road network. The achievement of sustainability objectives for urban mobility is probably compatible with all socioeconomic contexts.By measuring the distance of world cities from the inferred sustainability profile, we finally derive a geography of sustainability for mobility systems. The cities closest to the sustainability profile are in Central Europe as well as in affluent countries of the Far East. Car-dependent American cities are the farthest from the desired sustainability profile.

  18. Network Analysis of Urban Traffic with Big Bus Data

    OpenAIRE

    Zhao, Kai

    2016-01-01

    Urban traffic analysis is crucial for traffic forecasting systems, urban planning and, more recently, various mobile and network applications. In this paper, we analyse urban traffic with network and statistical methods. Our analysis is based on one big bus dataset containing 45 million bus arrival samples in Helsinki. We mainly address following questions: 1. How can we identify the areas that cause most of the traffic in the city? 2. Why there is a urban traffic? Is bus traffic a key cause ...

  19. Urbanism, Neighborhood Context, and Social Networks.

    Science.gov (United States)

    Cornwell, Erin York; Behler, Rachel L

    2015-09-01

    Theories of urbanism suggest that the urban context erodes individuals' strong social ties with friends and family. Recent research has narrowed focus to the neighborhood context, emphasizing how localized structural disadvantage affects community-level cohesion and social capital. In this paper, we argue that neighborhood context also shapes social ties with friends and family- particularly for community-dwelling seniors. We hypothesize that neighborhood disadvantage, residential instability, and disorder restrict residents' abilities to cultivate close relationships with neighbors and non-neighbor friends and family. Using data from the National Social Life, Health, and Aging Project (NSHAP), we find that older adults who live in disadvantaged neighborhoods have smaller social networks. Neighborhood disadvantage is also associated with less close network ties and less frequent interaction - but only among men. Furthermore, residents of disordered neighborhoods have smaller networks and weaker ties. We urge scholars to pay greater attention to how neighborhood context contributes to disparities in network-based access to resources.

  20. Dutch City Network feeds the Innovation of Urban Agriculture

    NARCIS (Netherlands)

    Jansma, J.E.; Veen, E.J.; Kop, van de P.J.; Eijk, van O.N.M.

    2015-01-01

    Since 2010, the Dutch City Network on Urban Agriculture (Stedennetwerk in Dutch), has linked up civil servants of fourteen cities in order to see opportunities, share knowledge and solve issues on urban agriculture in their cities. Though it started as an internally focused network for civil

  1. Knowledge Production, Urban Locations and the Importance of Local Networks

    DEFF Research Database (Denmark)

    Skytt-Larsen, Christine Benna; Winther, Lars

    2015-01-01

    This paper analyses the relationship between knowledge production and urban locations in industrial design, a knowledge-intensive business service (KIBS). KIBS concentrate in urban locations. This is often explained by the co-location of client firms and market access in large cities. Recent...... research on knowledge production, however, reveals that knowledge productive networks are significant for both the competitiveness and location of KIBS. Thus, to understand the urban location of industrial design, it is important to analyse how knowledge production is organized within the industry....... Industrial design is concentrated in urban locations, but most of its clients are located elsewhere. Hence, it seems that industrial design firms concentrate in urban locations mainly because their knowledge networks include specific types of formal and informal local social networks....

  2. The Network Analysis of Urban Streets: A Dual Approach

    OpenAIRE

    Porta, Sergio; Crucitti, Paolo; Latora, Vito

    2004-01-01

    The application of the network approach to the urban case poses several questions in terms of how to deal with metric distances, what kind of graph representation to use, what kind of measures to investigate, how to deepen the correlation between measures of the structure of the network and measures of the dynamics on the network, what are the possible contributions from the GIS community. In this paper, the authors addresses a study of six cases of urban street networks characterised by diff...

  3. The Topological Analysis of Urban Transit System as a Small-World Network

    OpenAIRE

    Zhaosheng Yang; Huxing Zhou; Peng Gao; Hong Chen; Nan Zhang

    2011-01-01

    This paper proposes a topological analysis of urban transit system based on a functional representation network constructed from the urban transit system in Beijing. The representation gives a functional view on nodes named a transit line. Statistical measures are computed and introduced in complex network analysis. It shows that the urban transit system forms small-world networks and exhibits properties different from random networks and regular networks. Furthermore, the topological propert...

  4. Decentralized Sensor Fusion for Ubiquitous Networking Robotics in Urban Areas

    Science.gov (United States)

    Sanfeliu, Alberto; Andrade-Cetto, Juan; Barbosa, Marco; Bowden, Richard; Capitán, Jesús; Corominas, Andreu; Gilbert, Andrew; Illingworth, John; Merino, Luis; Mirats, Josep M.; Moreno, Plínio; Ollero, Aníbal; Sequeira, João; Spaan, Matthijs T.J.

    2010-01-01

    In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites), a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted. PMID:22294927

  5. Procedural modeling of urban layout: population, land use, and road network

    NARCIS (Netherlands)

    Lyu, X.; Han, Q.; de Vries, B.

    2017-01-01

    This paper introduces an urban simulation system generating urban layouts with population, road network and land use layers. The desired urban spatial structure is obtained by generating a population map based on population density models. The road network is generated at two spatial levels

  6. Decentralized Sensor Fusion for Ubiquitous Networking Robotics in Urban Areas

    Directory of Open Access Journals (Sweden)

    Aníbal Ollero

    2010-03-01

    Full Text Available In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites, a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted.

  7. Multilayered complex network datasets for three supply chain network archetypes on an urban road grid.

    Science.gov (United States)

    Viljoen, Nadia M; Joubert, Johan W

    2018-02-01

    This article presents the multilayered complex network formulation for three different supply chain network archetypes on an urban road grid and describes how 500 instances were randomly generated for each archetype. Both the supply chain network layer and the urban road network layer are directed unweighted networks. The shortest path set is calculated for each of the 1 500 experimental instances. The datasets are used to empirically explore the impact that the supply chain's dependence on the transport network has on its vulnerability in Viljoen and Joubert (2017) [1]. The datasets are publicly available on Mendeley (Joubert and Viljoen, 2017) [2].

  8. Envisioning Networked Urban Mobilities : Art, Performances, Impacts

    NARCIS (Netherlands)

    Kjaerulf, Aslak Aamot; Kesselring, Sven; Peters, Peter; Hannam, Kevin

    2017-01-01

    Envisioning Networked Urban Mobilities brings together scientific reflections on the relations of art and urban mobilities and artistic research on the topic. The editors open the book by setting out the concept grounded in the exhibition curated by Aslak Aamot Kjærulff and refers to earlier work on

  9. URBAN COHESION: A PUBLIC SPACE NETWORK ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Ana Júlia Pinto

    2015-07-01

    With this in mind, we have analysed one study case in Barcelona – the Barceloneta neighbourhood, a historic quarter outside the old walled city that is now part of its consolidated urban fabric. The analysis of this case allows us to assess both (1 the role that the urban layout plays in the configuration of the public space network, forcing us to reflect on the role of “boundaries” as fundamental elements in the articulation among the local and overall public space networks in the city; and (2 the role of several socio-economic dynamics affecting to the everyday life of these neighbourhoods

  10. Predicting expressway crash frequency using a random effect negative binomial model: A case study in China.

    Science.gov (United States)

    Ma, Zhuanglin; Zhang, Honglu; Chien, Steven I-Jy; Wang, Jin; Dong, Chunjiao

    2017-01-01

    To investigate the relationship between crash frequency and potential influence factors, the accident data for events occurring on a 50km long expressway in China, including 567 crash records (2006-2008), were collected and analyzed. Both the fixed-length and the homogeneous longitudinal grade methods were applied to divide the study expressway section into segments. A negative binomial (NB) model and a random effect negative binomial (RENB) model were developed to predict crash frequency. The parameters of both models were determined using the maximum likelihood (ML) method, and the mixed stepwise procedure was applied to examine the significance of explanatory variables. Three explanatory variables, including longitudinal grade, road width, and ratio of longitudinal grade and curve radius (RGR), were found as significantly affecting crash frequency. The marginal effects of significant explanatory variables to the crash frequency were analyzed. The model performance was determined by the relative prediction error and the cumulative standardized residual. The results show that the RENB model outperforms the NB model. It was also found that the model performance with the fixed-length segment method is superior to that with the homogeneous longitudinal grade segment method. Copyright © 2016. Published by Elsevier Ltd.

  11. Procedural modeling of urban layout: population, land use, and road network

    OpenAIRE

    Lyu, X.; Han, Q.; de Vries, B.

    2017-01-01

    This paper introduces an urban simulation system generating urban layouts with population, road network and land use layers. The desired urban spatial structure is obtained by generating a population map based on population density models. The road network is generated at two spatial levels corresponding to the road hierarchy. The land use allocation is based on the What If? allocation model. The expected results are urban layouts suitable for academic scenario analysis.

  12. Outlier Detection in Urban Air Quality Sensor Networks

    NARCIS (Netherlands)

    van Zoest, V.M.; Stein, A.; Hoek, Gerard

    2018-01-01

    Low-cost urban air quality sensor networks are increasingly used to study the spatio-temporal variability in air pollutant concentrations. Recently installed low-cost urban sensors, however, are more prone to result in erroneous data than conventional monitors, e.g., leading to outliers. Commonly

  13. Networks as Tools for Urban Sustainability

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole; Tollin, Nicola

    2004-01-01

    Due to the increasing number of networks related to sustainable development (SUD) the paper focuses on understanding in which way networks can be considered useful tools for sustainable urban development, taking particularly into consideration the networks potential of spreading innovative policies...... will be discussed through a case study of a Danish municipal network on Sustainable Development, Dogme 2000 . This network has become quite successful in terms of learning and innovation, committing actors, and influencing local policies, to a larger extent than other SUD-networks the municipalities are involved in....... By applying the GREMI -theories of “innovative milieux” (Aydalot, 1986; Camagni, 1991) to the case study, we will suggest some reasons for the benefits achieved by the Dogme-network, compared to other networks. This analysis will point to the existence of an “innovative milieu” on sustainability within...

  14. An Intelligent Cooperative Visual Sensor Network for Urban Mobility.

    Science.gov (United States)

    Leone, Giuseppe Riccardo; Moroni, Davide; Pieri, Gabriele; Petracca, Matteo; Salvetti, Ovidio; Azzarà, Andrea; Marino, Francesco

    2017-11-10

    Smart cities are demanding solutions for improved traffic efficiency, in order to guarantee optimal access to mobility resources available in urban areas. Intelligent video analytics deployed directly on board embedded sensors offers great opportunities to gather highly informative data about traffic and transport, allowing reconstruction of a real-time neat picture of urban mobility patterns. In this paper, we present a visual sensor network in which each node embeds computer vision logics for analyzing in real time urban traffic. The nodes in the network share their perceptions and build a global and comprehensive interpretation of the analyzed scenes in a cooperative and adaptive fashion. This is possible thanks to an especially designed Internet of Things (IoT) compliant middleware which encompasses in-network event composition as well as full support of Machine-2-Machine (M2M) communication mechanism. The potential of the proposed cooperative visual sensor network is shown with two sample applications in urban mobility connected to the estimation of vehicular flows and parking management. Besides providing detailed results of each key component of the proposed solution, the validity of the approach is demonstrated by extensive field tests that proved the suitability of the system in providing a scalable, adaptable and extensible data collection layer for managing and understanding mobility in smart cities.

  15. Analyzing the Impact of Highways Associated with Farmland Loss under Rapid Urbanization

    Directory of Open Access Journals (Sweden)

    Jie Song

    2016-06-01

    Full Text Available Highway construction has accelerated urban growth and induced direct and indirect changes to land use. Although many studies have analyzed the relationship between highway construction and local development, relatively less attention has been paid to clarifying the various impacts of highways associated with farmland loss. This paper integrates GIS spatial analysis, remote sensing, buffer analysis and landscape metrics to analyze the landscape pattern change induced by direct and indirect highway impacts. This paper explores the interaction between the impact of highways and farmland loss, using the case of the highly urbanized traffic hubs in eastern China, Hang-Jia-Hu Plain. Our results demonstrate that the Hang-Jia-Hu Plain experienced extensive highway construction during 1990–2010, with a clear acceleration of expressway development since 2000. This unprecedented highway construction has directly fragmented the regional landscape and indirectly disturbed the regional landscape by attracting a large amount of built-up land transition from farmland during the last two decades. In the highway-effect zone, serious farmland loss initially occurred in the urban region and then spread to the rural region. Moreover, we found the discontinuous expansion of built-up land scattered the farmland in the rural region and expressway-effect zone. Furthermore, farmland protection policies in the 1990s had the effect of controlling the total area of farmland loss. However, the cohesive farmland structure was still fragmented by the direct and indirect impacts of highway construction. We suggest that an overall farmland protection system should be established to enhance spatial control and mitigate the adverse impacts caused by highway construction. This work improves the understanding of regional sustainable development, and provides a scientific basis for balanced urban development with farmland protection in decision-making processes.

  16. Understanding structure of urban traffic network based on spatial-temporal correlation analysis

    Science.gov (United States)

    Yang, Yanfang; Jia, Limin; Qin, Yong; Han, Shixiu; Dong, Honghui

    2017-08-01

    Understanding the structural characteristics of urban traffic network comprehensively can provide references for improving road utilization rate and alleviating traffic congestion. This paper focuses on the spatial-temporal correlations between different pairs of traffic series and proposes a complex network-based method of constructing the urban traffic network. In the network, the nodes represent road segments, and an edge between a pair of nodes is added depending on the result of significance test for the corresponding spatial-temporal correlation. Further, a modified PageRank algorithm, named the geographical weight-based PageRank algorithm (GWPA), is proposed to analyze the spatial distribution of important segments in the road network. Finally, experiments are conducted by using three kinds of traffic series collected from the urban road network in Beijing. Experimental results show that the urban traffic networks constructed by three traffic variables all indicate both small-world and scale-free characteristics. Compared with the results of PageRank algorithm, GWPA is proved to be valid in evaluating the importance of segments and identifying the important segments with small degree.

  17. Experimental research on safety impacts of the inside shoulder based on driving simulation.

    Science.gov (United States)

    Zhao, Xiaohua; Ding, Han; Wu, Yiping; Ma, Jianming; Zhong, Liande

    2015-03-01

    Statistical data shows that single-vehicle crashes account for half of all traffic crashes on expressways in China, and previous research has indicated that main contributing factors were related to whether and how the inside shoulder was paved. The inside shoulder provides space for drivers to make evasive maneuvers and accommodate driver errors. However, lower-cost construction solutions in China have resulted in the design of numerous urban expressway segments that lack inside shoulders. This paper has two objectives. The first is to reveal the safety impacts of inside shoulders on urban expressways by driving simulator experiment. The second objective is to propose optimal range and recommended value of inside shoulder width for designing inside shoulders of urban expressways. The empirical data, including subjects' eye movement data, heart rate (HR) and the lateral position of vehicles, were collected in a driving simulator. The data were analyzed to evaluate the safety impacts of the inside shoulder. The results have revealed that the inside shoulder has an impact on drivers' visual perception, behaviors, and psychology; in particular, it has a significant effect on vehicle operations. In addition, this paper recommends the desired and optimal inside shoulder widths for eight-lane, two-way divided expressways. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. An Intelligent Cooperative Visual Sensor Network for Urban Mobility

    Science.gov (United States)

    Leone, Giuseppe Riccardo; Petracca, Matteo; Salvetti, Ovidio; Azzarà, Andrea

    2017-01-01

    Smart cities are demanding solutions for improved traffic efficiency, in order to guarantee optimal access to mobility resources available in urban areas. Intelligent video analytics deployed directly on board embedded sensors offers great opportunities to gather highly informative data about traffic and transport, allowing reconstruction of a real-time neat picture of urban mobility patterns. In this paper, we present a visual sensor network in which each node embeds computer vision logics for analyzing in real time urban traffic. The nodes in the network share their perceptions and build a global and comprehensive interpretation of the analyzed scenes in a cooperative and adaptive fashion. This is possible thanks to an especially designed Internet of Things (IoT) compliant middleware which encompasses in-network event composition as well as full support of Machine-2-Machine (M2M) communication mechanism. The potential of the proposed cooperative visual sensor network is shown with two sample applications in urban mobility connected to the estimation of vehicular flows and parking management. Besides providing detailed results of each key component of the proposed solution, the validity of the approach is demonstrated by extensive field tests that proved the suitability of the system in providing a scalable, adaptable and extensible data collection layer for managing and understanding mobility in smart cities. PMID:29125535

  19. An Intelligent Cooperative Visual Sensor Network for Urban Mobility

    Directory of Open Access Journals (Sweden)

    Giuseppe Riccardo Leone

    2017-11-01

    Full Text Available Smart cities are demanding solutions for improved traffic efficiency, in order to guarantee optimal access to mobility resources available in urban areas. Intelligent video analytics deployed directly on board embedded sensors offers great opportunities to gather highly informative data about traffic and transport, allowing reconstruction of a real-time neat picture of urban mobility patterns. In this paper, we present a visual sensor network in which each node embeds computer vision logics for analyzing in real time urban traffic. The nodes in the network share their perceptions and build a global and comprehensive interpretation of the analyzed scenes in a cooperative and adaptive fashion. This is possible thanks to an especially designed Internet of Things (IoT compliant middleware which encompasses in-network event composition as well as full support of Machine-2-Machine (M2M communication mechanism. The potential of the proposed cooperative visual sensor network is shown with two sample applications in urban mobility connected to the estimation of vehicular flows and parking management. Besides providing detailed results of each key component of the proposed solution, the validity of the approach is demonstrated by extensive field tests that proved the suitability of the system in providing a scalable, adaptable and extensible data collection layer for managing and understanding mobility in smart cities.

  20. An Optimal Balance between Efficiency and Safety of Urban Drainage Networks

    Science.gov (United States)

    Seo, Y.

    2014-12-01

    Urban drainage networks have been developed to promote the efficiency of a system in terms of drainage time so far. Typically, a drainage system is designed to drain water from developed areas promptly as much as possible during floods. In this regard, an artificial drainage system have been considered to be more efficient compared to river networks in nature. This study examined artificial drainage networks and the results indicate they can be less efficient in terms of network configuration compared with river networks, which is counter-intuitive. The case study of 20 catchments in Seoul, South Korea shows that they have wide range of efficiency in terms of network configuration and consequently, drainage time. This study also demonstrates that efficient drainage networks are more sensitive to spatial and temporal rainfall variation such as rainstorm movement. Peak flows increase more than two times greater in effective drainage networks compared with inefficient and highly sinuous drainage networks. Combining these results, this study implies that the layout of a drainage network is an important factor in terms of efficient drainage and also safety in urban catchments. Design of an optimal layout of the drainage network can be an alternative non-structural measures that mitigate potential risks and it is crucial for the sustainability of urban environments.

  1. Coordination between Subway and Urban Space: A Networked Approach

    Directory of Open Access Journals (Sweden)

    Lei Mao

    2014-05-01

    Full Text Available This paper selects Changsha as a case study and constructs the models of the subway network and the urban spatial network by using planning data. In the network models, the districts of Changsha are regarded as nodes and the connections between each pair of districts are regarded as edges. The method is based on quantitative analysis of the node weights and the edge weights, which are defined in the complex network theory. And the structures of subway and urban space are visualized in the form of networks. Then, through analyzing the discrepancy coefficients of the corresponding nodes and edges, the paper carries out a comparison between the two networks to evaluate the coordination. The results indicate that only 21.4% of districts and 13.2% of district connections have a rational coordination. Finally, the strategies are put forward for optimization, which suggest adjusting subway transit density, regulating land-use intensity and planning new mass transits for the uncoordinated parts.

  2. Integration of Neural Networks and Cellular Automata for Urban Planning

    Institute of Scientific and Technical Information of China (English)

    Anthony Gar-on Yeh; LI Xia

    2004-01-01

    This paper presents a new type of cellular automata (CA) model for the simulation of alternative land development using neural networks for urban planning. CA models can be regarded as a planning tool because they can generate alternative urban growth. Alternative development patterns can be formed by using different sets of parameter values in CA simulation. A critical issue is how to define parameter values for realistic and idealized simulation. This paper demonstrates that neural networks can simplify CA models but generate more plausible results. The simulation is based on a simple three-layer network with an output neuron to generate conversion probability. No transition rules are required for the simulation. Parameter values are automatically obtained from the training of network by using satellite remote sensing data. Original training data can be assessed and modified according to planning objectives. Alternative urban patterns can be easily formulated by using the modified training data sets rather than changing the model.

  3. The anatomy of urban social networks and its implications in the searchability problem

    Science.gov (United States)

    Herrera-Yagüe, C.; Schneider, C. M.; Couronné, T.; Smoreda, Z.; Benito, R. M.; Zufiria, P. J.; González, M. C.

    2015-01-01

    The appearance of large geolocated communication datasets has recently increased our understanding of how social networks relate to their physical space. However, many recurrently reported properties, such as the spatial clustering of network communities, have not yet been systematically tested at different scales. In this work we analyze the social network structure of over 25 million phone users from three countries at three different scales: country, provinces and cities. We consistently find that this last urban scenario presents significant differences to common knowledge about social networks. First, the emergence of a giant component in the network seems to be controlled by whether or not the network spans over the entire urban border, almost independently of the population or geographic extension of the city. Second, urban communities are much less geographically clustered than expected. These two findings shed new light on the widely-studied searchability in self-organized networks. By exhaustive simulation of decentralized search strategies we conclude that urban networks are searchable not through geographical proximity as their country-wide counterparts, but through an homophily-driven community structure. PMID:26035529

  4. Passenger flow analysis of Beijing urban rail transit network using fractal approach

    Science.gov (United States)

    Li, Xiaohong; Chen, Peiwen; Chen, Feng; Wang, Zijia

    2018-04-01

    To quantify the spatiotemporal distribution of passenger flow and the characteristics of an urban rail transit network, we introduce four radius fractal dimensions and two branch fractal dimensions by combining a fractal approach with passenger flow assignment model. These fractal dimensions can numerically describe the complexity of passenger flow in the urban rail transit network and its change characteristics. Based on it, we establish a fractal quantification method to measure the fractal characteristics of passenger follow in the rail transit network. Finally, we validate the reasonability of our proposed method by using the actual data of Beijing subway network. It has been shown that our proposed method can effectively measure the scale-free range of the urban rail transit network, network development and the fractal characteristics of time-varying passenger flow, which further provides a reference for network planning and analysis of passenger flow.

  5. Networks Within Cities and Among Cities: A Paradigm for Urban Development and Governance

    OpenAIRE

    Pompili, Tomaso

    2006-01-01

    Networks and networking have become fashionable concepts and terms in regional science, and in particular in regional and urban geography in the last decade: we speak about network firms, network society, network economy but also network cities, city-networks, reti urbane, reseaux de villes. Only catch-words for somebody; a true new scientific paradigm according to others. Our opinion is that in fact we are confronted with a new paradigm in spatial sciences, under some precise conditions: - t...

  6. The improved degree of urban road traffic network: A case study of Xiamen, China

    Science.gov (United States)

    Wang, Shiguang; Zheng, Lili; Yu, Dexin

    2017-03-01

    The complex network theory is applied to the study of urban road traffic network topology, and we constructed a new measure to characterize an urban road network. It is inspiring to quantify the interaction more appropriately between nodes in complex networks, especially in the field of traffic. The measure takes into account properties of lanes (e.g. number of lanes, width, traffic direction). As much, it is a more comprehensive measure in comparison to previous network measures. It can be used to grasp the features of urban street network more clearly. We applied this measure to the road network in Xiamen, China. Based on a standard method from statistical physics, we examined in more detail the distribution of this new measure and found that (1) due to the limitation of space geographic attributes, traditional research conclusions acquired by using the original definition of degree to study the primal approach modeled urban street network are not very persuasive; (2) both of the direction of the network connection and the degree's odd or even classifications need to be analyzed specifically; (3) the improved degree distribution presents obvious hierarchy, and hierarchical values conform to the power-law distribution, and correlation of our new measure shows some significant segmentation of the urban road network.

  7. Pollution level and health risk assessment of road dust from Islamabad expressway, Pakistan

    International Nuclear Information System (INIS)

    Faiz, Y.; Siddique, N.

    2012-01-01

    Thirteen road dust and four soil samples were analyzed using instrumental neutron activation analysis (INAA) to determine the elemental composition of road dust collected from Islamabad Expressway. The amounts of most of the elements determined were generally in the lower range of the global data with the exception of Ce, Nd, Sn and Zr which were measured at higher concentrations in Islamabad. Pollution parameters and indicators such as Enrichment Factors (EFs), Pollution Load Index (PLI), Geo accumulation Index (Igeo), Pollution Index (PI) and Integrated Pollution Index (IPI) showed that the area around Islamabad Expressway is low to moderately polluted especially by elements such as Mg and Sb. The IPI of the elements was found to vary in the order; Mg>Sb>Cu>Sr Pb>Ga>Na >Sn Zn>Yb>Se>Hf. Elemental health risk was assessed through dose calculations for carcinogenic and non carcinogenic metals; and by the determination of LADD (lifetime average daily dose). The carcinogenic metals studied showed the following variation in their LADD values; Cr>Ni>Co>Cd>As. Dose calculations for non-cancerous and cancerous elements showed the data obtained to lie within the safe threshold of 10 3 10 6 mg kg/sup -1/ day/sup -1/ for most elements. The soil based elements Al, Fe, K, Mg, Na and Ti were the exception and originated from the exposed soil around the highway. Moreover highest Hazard Index (HI) was found to be associated with the presence of Al, Cr, Pb and V in road dust showing soil, transport and industry to be the major sources of road dust. (orig./A.B.)

  8. High Resolution Sensing and Control of Urban Water Networks

    Science.gov (United States)

    Bartos, M. D.; Wong, B. P.; Kerkez, B.

    2016-12-01

    We present a framework to enable high-resolution sensing, modeling, and control of urban watersheds using (i) a distributed sensor network based on low-cost cellular-enabled motes, (ii) hydraulic models powered by a cloud computing infrastructure, and (iii) automated actuation valves that allow infrastructure to be controlled in real time. This platform initiates two major advances. First, we achieve a high density of measurements in urban environments, with an anticipated 40+ sensors over each urban area of interest. In addition to new measurements, we also illustrate the design and evaluation of a "smart" control system for real-world hydraulic networks. This control system improves water quality and mitigates flooding by using real-time hydraulic models to adaptively control releases from retention basins. We evaluate the potential of this platform through two ongoing deployments: (i) a flood monitoring network in the Dallas-Fort Worth metropolitan area that detects and anticipates floods at the level of individual roadways, and (ii) a real-time hydraulic control system in the city of Ann Arbor, MI—soon to be one of the most densely instrumented urban watersheds in the United States. Through these applications, we demonstrate that distributed sensing and control of water infrastructure can improve flash flood predictions, emergency response, and stormwater contaminant mitigation.

  9. Networks as Tools for Sustainable Urban Development

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole; Tollin, Nicola

    will be discussed through a case study of a Danish municipal network on Sustainable Development, Dogme 20001. This network has become quite successful in terms of learning and innovation, committing actors, and influencing local policies, to a larger extent than other SUD-networks the municipalities are involved in....... By applying the GREMI2-theories of “innovative milieux” (Aydalot, 1986; Camagni, 1991) to the case study, we will suggest some reasons for the benefits achieved by the Dogme-network, compared to other networks. This analysis will point to the existence of an “innovative milieu” on sustainability within......Due to the increasing number of networks related to sustainable development (SUD) the paper focuses on understanding in which way networks can be considered useful tools for sustainable urban development, taking particularly into consideration the networks potential of spreading innovative policies...

  10. Bird-plant interaction networks: a study on frugivory in Brazilian urban areas

    Directory of Open Access Journals (Sweden)

    Diego Silva Freitas Oliveira

    2015-12-01

    Full Text Available In Brazil, few studies compare the consumption of native and exotic fruits, especially in an urban environment. The Network Theory may be useful in such studies, because it allows evaluating many bird and plant species involved in interactions. The goals of this study were: evaluate a bird frugivory interaction network in an urban environment; checking the role played by native and exotic plants in the network and comparing the consumer assemblies of these two plant groups. A literature review on bird frugivory in Brazilian urban areas was conducted, as well as an analysis to create an interaction network on a regional scale. The analysis included 15 papers with 70 bird species eating fruits from 15 plant species (6 exotic and 9 native. The exotic and native fruit consumers did not form different groups and the interaction network was significantly nested (NODF = 0.30; p < 0.01 and not modular (M = 0.36; p = 0.16. Two exotic plant species are in the generalist core of the frugivory network (Ficus microcarpa and Michelia champaca. The results point out that a relatively diversified bird group eats fruits in Brazilian urban areas in an opportunistic way, with no preference for native or exotic plants.

  11. Model and Empirical Study on Several Urban Public Transport Networks in China

    Science.gov (United States)

    Ding, Yimin; Ding, Zhuo

    2012-07-01

    In this paper, we present the empirical investigation results on the urban public transport networks (PTNs) and propose a model to understand the results obtained. We investigate some urban public traffic networks in China, which are the urban public traffic networks of Beijing, Guangzhou, Wuhan and etc. The empirical results on the big cities show that the accumulative act-degree distributions of PTNs take neither power function forms, nor exponential function forms, but they are described by a shifted power function, and the accumulative act-degree distributions of PTNs in medium-sized or small cities follow the same law. In the end, we propose a model to show a possible evolutionary mechanism for the emergence of such network. The analytic results obtained from this model are in good agreement with the empirical results.

  12. Vulnerability Analysis of Urban Drainage Systems: Tree vs. Loop Networks

    Directory of Open Access Journals (Sweden)

    Chi Zhang

    2017-03-01

    Full Text Available Vulnerability analysis of urban drainage networks plays an important role in urban flood management. This study analyzes and compares the vulnerability of tree and loop systems under various rainfall events to structural failure represented by pipe blockage. Different pipe blockage scenarios, in which one of the pipes in an urban drainage network is assumed to be blocked individually, are constructed and their impacts on the network are simulated under different storm events. Furthermore, a vulnerability index is defined to measure the vulnerability of the drainage systems before and after the implementation of adaptation measures. The results obtained indicate that the tree systems have a relatively larger proportion of critical hydraulic pipes than the loop systems, thus the vulnerability of tree systems is substantially greater than that of the loop systems. Furthermore, the vulnerability index of tree systems is reduced after they are converted into a loop system with the implementation of adaptation measures. This paper provides an insight into the differences in the vulnerability of tree and loop systems, and provides more evidence for development of adaptation measures (e.g., tanks to reduce urban flooding.

  13. Planning of Green Space Ecological Network in Urban Areas: An Example of Nanchang, China.

    Science.gov (United States)

    Li, Haifeng; Chen, Wenbo; He, Wei

    2015-10-15

    Green space plays an important role in sustainable urban development and ecology by virtue of multiple environmental, recreational, and economic benefits. Constructing an effective and harmonious urban ecological network and maintaining a sustainable living environment in response to rapid urbanization are the key issues required to be resolved by landscape planners. In this paper, Nanchang City, China was selected as a study area. Based on a series of landscape metrics, the landscape pattern analysis of the current (in 2005) and planned (in 2020) green space system were, respectively, conducted by using FRAGSTATS 3.3 software. Considering the actual situation of the Nanchang urban area, a "one river and two banks, north and south twin cities" ecological network was constructed by using network analysis. Moreover, the ecological network was assessed by using corridor structure analysis, and the improvement of an ecological network on the urban landscape was quantitatively assessed through a comparison between the ecological network and green space system planning. The results indicated that: (1) compared to the green space system in 2005, the planned green space system in 2020 of the Nanchang urban area will decline in both districts (Changnan and Changbei districts). Meanwhile, an increase in patch density and a decrease in mean patch size of green space patches at the landscape level implies the fragmentation of the urban green space landscape. In other words, the planned green space system does not necessarily improve the present green space system; (2) the ecological network of two districts has high corridor density, while Changnan's ecological network has higher connectivity, but Changbei's ecological network is more viable from an economic point of view, since it has relatively higher cost efficiency; (3) decrease in patch density, Euclidean nearest neighbor distance, and an increase in mean patch size and connectivity implied that the ecological network

  14. Variability of multifractal parameters in an urban precipitation monitoring network

    Science.gov (United States)

    Licznar, Paweł; De Michele, Carlo; Dżugaj, Dagmara; Niesobska, Maria

    2014-05-01

    Precipitation especially over urban areas is considered a highly non-linear process, with wide variability over a broad range of temporal and spatial scales. Despite obvious limitations of rainfall gauges location at urban sites, rainfall monitoring by gauge networks is a standard solution of urban hydrology. Often urban precipitation gauge networks are formed by modern electronic gauges and connected to control units of centralized urban drainage systems. Precipitation data, recorded online through these gauge networks, are used in so called Real-Time-Control (RTC) systems for the development of optimal strategies of urban drainage outflows management. As a matter of fact, the operation of RTC systems is motivated mainly by the urge of reducing the severity of urban floods and combined sewerage overflows, but at the same time, it creates new valuable precipitation data sources. The variability of precipitation process could be achieved by investigating multifractal behavior displayed by the temporal structure of precipitation data. There are multiply scientific communications concerning multifractal properties of point-rainfall data from different worldwide locations. However, very little is known about the close variability of multifractal parameters among closely located gauges, at the distances of single kilometers. Having this in mind, here we assess the variability of multifractal parameters among gauges of the urban precipitation monitoring network in Warsaw, Poland. We base our analysis on the set of 1-minute rainfall time series recorded in the period 2008-2011 by 25 electronic weighing type gauges deployed around the city by the Municipal Water Supply and Sewerage Company in Warsaw as a part of local RTC system. The presence of scale invariance and multifractal properties in the precipitation process was investigated with spectral analysis, functional box counting method and studying the probability distributions and statistical moments of the rainfall

  15. Hybrid Evolutionary Metaheuristics for Concurrent Multi-Objective Design of Urban Road and Public Transit Networks

    NARCIS (Netherlands)

    Miandoabchi, Elnaz; Farahani, Reza Zanjirani; Dullaert, Wout; Szeto, W. Y.

    This paper addresses a bi-modal multi-objective discrete urban road network design problem with automobile and bus flow interaction. The problem considers the concurrent urban road and bus network design in which the authorities play a major role in designing bus network topology. The road network

  16. Vulnerability Analysis of Urban Rail Transit Networks: A Case Study of Shanghai, China

    Directory of Open Access Journals (Sweden)

    Daniel (Jian Sun

    2015-05-01

    Full Text Available Rail transit is developing rapidly in major cities of China and has become a key component of urban transport. Nevertheless, the security and reliability in operation are significant issues that cannot be neglected. In this paper, the network and station vulnerabilities of the urban rail transit system were analyzed based on complex network and graph theories. A vulnerability evaluation model was proposed by accounting metro interchange and passenger flow and further validated by a case study of Shanghai Metro with full-scale network and real-world traffic data. It is identified that the urban rail transit network is rather robust to random attacks, but is vulnerable to the largest degree node-based attacks and the highest betweenness node-based attacks. Metro stations with a large node degree are more important in maintaining the network size, while stations with a high node betweenness are critical to network efficiency and origin-destination (OD connectivity. The most crucial stations in maintaining network serviceability do not necessarily have the highest passenger throughput or the largest structural connectivity. A comprehensive evaluation model as proposed is therefore essential to assess station vulnerability, so that attention can be placed on appropriate nodes within the metro system. The findings of this research are of both theoretical and practical significance for urban rail transit network design and performance evaluation.

  17. Urban acid deposition. Results from the GMADS network, 1990

    Energy Technology Data Exchange (ETDEWEB)

    Conlan, D.E.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E.

    1991-07-01

    This fourth annual data report of the Greater Manchester Acid Deposition Survey (GMADS) gives results from the urban precipitation chemistry network across Greater Manchester and Warrington for 1990. Full analytical methods are described along with precision and accuracy of the methods used. The spatial variability of precipitation chemistry and deposition over this urban region was investigated using a network of twenty collectors. Concentrations of non marine sulphate, ammonium, calcium and hydrogen, and nitrogen dioxide gas concentrations all show significant spatial variability. The spatial variability of the deposition rates of non marine sulphate, nitrate, ammonium, hydrogen and calcium were significant. 40 refs., 13 figs., 9 tabs., 1 app.

  18. Network design for quantifying urban CO2 emissions: assessing trade-offs between precision and network density

    Directory of Open Access Journals (Sweden)

    A. J. Turner

    2016-11-01

    Full Text Available The majority of anthropogenic CO2 emissions are attributable to urban areas. While the emissions from urban electricity generation often occur in locations remote from consumption, many of the other emissions occur within the city limits. Evaluating the effectiveness of strategies for controlling these emissions depends on our ability to observe urban CO2 emissions and attribute them to specific activities. Cost-effective strategies for doing so have yet to be described. Here we characterize the ability of a prototype measurement network, modeled after the Berkeley Atmospheric CO2 Observation Network (BEACO2N in California's Bay Area, in combination with an inverse model based on the coupled Weather Research and Forecasting/Stochastic Time-Inverted Lagrangian Transport (WRF-STILT to improve our understanding of urban emissions. The pseudo-measurement network includes 34 sites at roughly 2 km spacing covering an area of roughly 400 km2. The model uses an hourly 1  ×  1 km2 emission inventory and 1  ×  1 km2 meteorological calculations. We perform an ensemble of Bayesian atmospheric inversions to sample the combined effects of uncertainties of the pseudo-measurements and the model. We vary the estimates of the combined uncertainty of the pseudo-observations and model over a range of 20 to 0.005 ppm and vary the number of sites from 1 to 34. We use these inversions to develop statistical models that estimate the efficacy of the combined model–observing system in reducing uncertainty in CO2 emissions. We examine uncertainty in estimated CO2 fluxes on the urban scale, as well as for sources embedded within the city such as a line source (e.g., a highway or a point source (e.g., emissions from the stacks of small industrial facilities. Using our inversion framework, we find that a dense network with moderate precision is the preferred setup for estimating area, line, and point sources from a combined uncertainty and cost

  19. Neighborhood disorder, peer network health, and substance use among young urban adolescents.

    Science.gov (United States)

    Mason, Michael J; Light, John M; Mennis, Jeremy; Rusby, Julie C; Westling, Erika; Crewe, Stephanie; Zaharakis, Nikola; Way, Thomas; Flay, Brian R

    2017-09-01

    The current study investigated the moderating effect of peer networks on neighborhood disorder's association with substance use in a sample of primarily African American urban adolescents. A convenience sample of 248 adolescents was recruited from urban health care settings and followed for two years, assessing psychological, social, and geographic risk and protective characteristics. A subset of 106 substance using participants were used for the analyses. A moderation model was tested to determine if the influence of neighborhood disorder (percent vacant housing, assault index, percent single parent headed households, percent home owner occupied, percent below poverty line) on substance use was moderated by peer network health (sum of peer risk and protective behaviors). Evidence for hypothesized peer network moderation was supported. A latent growth model found that peer network health is most strongly associated with lower baseline substance use for young adolescents residing in more disordered neighborhoods. Over the course of two years (ages approximately 14-16) this protective effect declines, and the decline is stronger for more disordered neighborhoods. Understanding the longitudinal moderating effects of peer networks within high-risk urban settings is important to the development and testing of contextually sensitive peer-based interventions. suggest that targeting the potential protective qualities of peer networks may be a promising approach for interventions seeking to reduce substance use, particularly among younger urban adolescents living in high-risk neighborhoods. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Functional Topology of Evolving Urban Drainage Networks

    Science.gov (United States)

    Yang, Soohyun; Paik, Kyungrock; McGrath, Gavan S.; Urich, Christian; Krueger, Elisabeth; Kumar, Praveen; Rao, P. Suresh C.

    2017-11-01

    We investigated the scaling and topology of engineered urban drainage networks (UDNs) in two cities, and further examined UDN evolution over decades. UDN scaling was analyzed using two power law scaling characteristics widely employed for river networks: (1) Hack's law of length (L)-area (A) [L∝Ah] and (2) exceedance probability distribution of upstream contributing area (δ) [P>(A≥δ>)˜aδ-ɛ]. For the smallest UDNs ((A≥δ>) plots for river networks are abruptly truncated, those for UDNs display exponential tempering [P>(A≥δ>)=aδ-ɛexp⁡>(-cδ>)]. The tempering parameter c decreases as the UDNs grow, implying that the distribution evolves in time to resemble those for river networks. However, the power law exponent ɛ for large UDNs tends to be greater than the range reported for river networks. Differences in generative processes and engineering design constraints contribute to observed differences in the evolution of UDNs and river networks, including subnet heterogeneity and nonrandom branching.

  1. Exploring the patterns and evolution of self-organized urban street networks through modeling

    Science.gov (United States)

    Rui, Yikang; Ban, Yifang; Wang, Jiechen; Haas, Jan

    2013-03-01

    As one of the most important subsystems in cities, urban street networks have recently been well studied by using the approach of complex networks. This paper proposes a growing model for self-organized urban street networks. The model involves a competition among new centers with different values of attraction radius and a local optimal principle of both geometrical and topological factors. We find that with the model growth, the local optimization in the connection process and appropriate probability for the loop construction well reflect the evolution strategy in real-world cities. Moreover, different values of attraction radius in centers competition process lead to morphological change in patterns including urban network, polycentric and monocentric structures. The model succeeds in reproducing a large diversity of road network patterns by varying parameters. The similarity between the properties of our model and empirical results implies that a simple universal growth mechanism exists in self-organized cities.

  2. Study on the correlation between the hierarchical urban system and high-speed railway network planning in China

    Directory of Open Access Journals (Sweden)

    Hong Sun

    2016-09-01

    Full Text Available This study examines the interrelatedness between the hierarchical structure of China׳s urban system and high-speed railway (HSR network planning at the national level. As a multi-layered system, the Chinese HSR can be categorized into three sub-networks, namely, the national HSR trunk network, the national HSR extensional network, and the intercity HSR network. By examining the direct HSR network connection, HSR nodal connection, and HSR operational frequency of 287 prefecture-level cities, this study demonstrates that the hierarchies of China׳s administrative, demographic, and economic urban systems strongly influence HSR network planning. The national HSR trunk network prioritizes the connection of top-level central cities, whereas the extensional network prioritizes cities at the lower level of the urban system. Moreover, the national HSR system forms the backbone of the HSR network structure based on a national scale, whereas the intercity HSR system satisfies the travel needs within urban agglomerations based on the regional level.

  3. Simulating urban growth by emphasis on connective routes network (case study: Bojnourd city

    Directory of Open Access Journals (Sweden)

    Mehdi Saadat Novin

    2017-06-01

    Full Text Available Development of urban construction and ever-increasing growth of population lead to landuse changes especially in agricultural lands, which play an important role in providing human food. According to this issue, a proper landuse planning is required to protecting and preserving the valuable agricultural lands and environment, in today’s world. The prediction of urban growth can help in understanding the potential impacts on a region’s water resource, economy and people. One of the effective parameters in development of cities is connective routes network and their different types and qualities that play an important role in decreasing or increasing the growth of the city. On the other hand, the type of the connective routes network is an important factor for the speed and quality of development. In this paper, two different scenarios were used to simulate landuse changes and analyzing their results. In first scenario, modeling is based on the effective parameters in urban growth without classification of connective routes network. In the second scenario, effective parameters in urban growth were considered and connective routes were classified in 6 different classes with different weights in order to examine their effect on urban development. Simulation of landuse has been carried out for 2020–2050. The results clearly showed the effect of the connective routes network classification in output maps so that the effect of the first and second main routes network in development, is conspicuous.

  4. MmWave Vehicle-to-Infrastructure Communication :Analysis of Urban Microcellular Networks

    Science.gov (United States)

    2017-05-01

    Vehicle-to-infrastructure (V2I) communication may provide high data rates to vehicles via millimeterwave (mmWave) microcellular networks. This report uses stochastic geometry to analyze the coverage of urban mmWave microcellular networks. Prior work ...

  5. Urban networks and Arctic outlands: Craft specialists and reindeer antler in Viking towns

    DEFF Research Database (Denmark)

    Ashby, Steven P.; Coutu, Ashley N.; Sindbæk, Søren Michael

    2015-01-01

    This paper presents the results of the use of a minimally destructive biomolecular technique to explore the resource networks behind one of the first specialized urban crafts in early mediaeval northern Europe: the manufacture of composite combs of deer antler. The research incorporates the largest...... the 780s ad at the latest, presenting the earliest unambiguous evidence for exchange-links between urban markets in the southern North Sea region and the Scandinavian Peninsula. The results demonstrate that the common conceptual distinction between urban hinterlands and long-distance trade conceals...... a vital continuity. Long-range networks were vital to urban activities from the first appearance of towns in this part of the world, preceding the historically documented maritime expansion of the Viking Age. We consequently suggest that urbanism is more appropriately defined and researched in terms...

  6. NETWORKING - THE URBAN AND REGIONAL DEVELOPMENT STRATEGY?

    Directory of Open Access Journals (Sweden)

    MARIA NOWICKA-SKOWRON

    2011-01-01

    Full Text Available The concept of innovations embraces everything that is connected with creation and application of new knowledge in order to win competitive advantage. A traditional approach applied by organizational and management sciences are not enough to explain and manage the development of enterprises as well as that of cities, regions and countries. According to a new approach to innovativeness, creation of innovations depends on a complex/system approach. A phenomenon of particular importance is the approach to network pro-innovation structures from the urban and regional point of view. What makes a network work is a mutual relation between actors who have same rights to access and participate in the network. The whole system must be perceived by every actor. Simultaneously, every actor is partially responsible for the whole. The nature of networking can be understood as a differentiated system of relations (particularly personal ones inside the network. Tolerance and trust are other foundations of information flow and information return.

  7. Fine-resolution Modeling of Urban-Energy Systems' Water Footprint in River Networks

    Science.gov (United States)

    McManamay, R.; Surendran Nair, S.; Morton, A.; DeRolph, C.; Stewart, R.

    2015-12-01

    Characterizing the interplay between urbanization, energy production, and water resources is essential for ensuring sustainable population growth. In order to balance limited water supplies, competing users must account for their realized and virtual water footprint, i.e. the total direct and indirect amount of water used, respectively. Unfortunately, publicly reported US water use estimates are spatially coarse, temporally static, and completely ignore returns of water to rivers after use. These estimates are insufficient to account for the high spatial and temporal heterogeneity of water budgets in urbanizing systems. Likewise, urbanizing areas are supported by competing sources of energy production, which also have heterogeneous water footprints. Hence, a fundamental challenge of planning for sustainable urban growth and decision-making across disparate policy sectors lies in characterizing inter-dependencies among urban systems, energy producers, and water resources. A modeling framework is presented that provides a novel approach to integrate urban-energy infrastructure into a spatial accounting network that accurately measures water footprints as changes in the quantity and quality of river flows. River networks (RNs), i.e. networks of branching tributaries nested within larger rivers, provide a spatial structure to measure water budgets by modeling hydrology and accounting for use and returns from urbanizing areas and energy producers. We quantify urban-energy water footprints for Atlanta, GA and Knoxville, TN (USA) based on changes in hydrology in RNs. Although water intakes providing supply to metropolitan areas were proximate to metropolitan areas, power plants contributing to energy demand in Knoxville and Atlanta, occurred 30 and 90km outside the metropolitan boundary, respectively. Direct water footprints from urban landcover primarily comprised smaller streams whereas indirect footprints from water supply reservoirs and energy producers included

  8. Social Networks and Health: Understanding the Nuances of Healthcare Access between Urban and Rural Populations.

    Science.gov (United States)

    Amoah, Padmore Adusei; Edusei, Joseph; Amuzu, David

    2018-05-13

    Communities and individuals in many sub-Saharan African countries often face limited access to healthcare. Hence, many rely on social networks to enhance their chances for adequate health care. While this knowledge is well-established, little is known about the nuances of how different population groups activate these networks to improve access to healthcare. This paper examines how rural and urban dwellers in the Ashanti Region in Ghana distinctively and systematically activate their social networks to enhance access to healthcare. It uses a qualitative cross-sectional design, with in-depth interviews of 79 primary participants (28 urban and 51 rural residents) in addition to the views of eight community leaders and eight health personnel. It was discovered that both intimate and distanced social networks for healthcare are activated at different periods by rural and urban residents. Four main stages of social networks activation, comprising different individuals and groups were observed among rural and urban dwellers. Among both groups, physical proximity, privacy, trust and sense of fairness, socio-cultural meaning attached to health problems, and perceived knowledge and other resources (mainly money) held in specific networks inherently influenced social network activation. The paper posits that a critical analysis of social networks may help to tailor policy contents to individuals and groups with limited access to healthcare.

  9. The Benefits of Using Dense Temperature Sensor Networks to Monitor Urban Warming

    Science.gov (United States)

    Twine, T. E.; Snyder, P. K.; Kucharik, C. J.; Schatz, J.

    2015-12-01

    Urban heat islands (UHIs) occur when urban and suburban areas experience temperatures that are elevated relative to their rural surroundings because of differences in the fraction of gray and green infrastructure. Studies have shown that communities most at risk for impacts from climate-related disasters (i.e., lower median incomes, higher poverty, lower education, and minorities) tend to live in the hottest areas of cities. Development of adequate climate adaptation tools for cities relies on knowledge of how temperature varies across space and time. Traditionally, a city's urban heat island has been quantified using near-surface air temperature measurements from a few sites. This methodology assumes (1) that the UHI can be characterized by the difference in air temperature from a small number of points, and (2) that these few points represent the urban and rural signatures of the region. This methodology ignores the rich information that could be gained from measurements across the urban to rural transect. This transect could traverse elevations, water bodies, vegetation fraction, and other land surface properties. Two temperature sensor networks were designed and implemented in the Minneapolis-Saint Paul, MN and Madison, WI metropolitan areas beginning in 2011 and 2012, respectively. Both networks use the same model sensor and record temperature every 15 minutes from ~150 sensors. Data from each network has produced new knowledge of how temperature varies diurnally and seasonally across the cities and how the UHI magnitude is influenced by weather phenomena (e.g., wind, snow cover, heat waves) and land surface characteristics such as proximity to inland lakes. However, the two metropolitan areas differ in size, population, structure, and orientation to water bodies. In addition, the sensor networks were established in very different manners. We describe these differences and present lessons learned from the design and ongoing efforts of these two dense networks

  10. Network Capacity Assessment of CHP-based Distributed Generation on Urban Energy Distribution Networks

    Science.gov (United States)

    Zhang, Xianjun

    The combined heat and power (CHP)-based distributed generation (DG) or dis-tributed energy resources (DERs) are mature options available in the present energy market, considered to be an effective solution to promote energy efficiency. In the urban environment, the electricity, water and natural gas distribution networks are becoming increasingly interconnected with the growing penetration of the CHP-based DG. Subsequently, this emerging interdependence leads to new topics meriting serious consideration: how much of the CHP-based DG can be accommodated and where to locate these DERs, and given preexisting constraints, how to quantify the mutual impacts on operation performances between these urban energy distribution networks and the CHP-based DG. The early research work was conducted to investigate the feasibility and design methods for one residential microgrid system based on existing electricity, water and gas infrastructures of a residential community, mainly focusing on the economic planning. However, this proposed design method cannot determine the optimal DG sizing and siting for a larger test bed with the given information of energy infrastructures. In this context, a more systematic as well as generalized approach should be developed to solve these problems. In the later study, the model architecture that integrates urban electricity, water and gas distribution networks, and the CHP-based DG system was developed. The proposed approach addressed the challenge of identifying the optimal sizing and siting of the CHP-based DG on these urban energy networks and the mutual impacts on operation performances were also quantified. For this study, the overall objective is to maximize the electrical output and recovered thermal output of the CHP-based DG units. The electricity, gas, and water system models were developed individually and coupled by the developed CHP-based DG system model. The resultant integrated system model is used to constrain the DG's electrical

  11. Intra-Urban Movement Flow Estimation Using Location Based Social Networking Data

    Science.gov (United States)

    Kheiri, A.; Karimipour, F.; Forghani, M.

    2015-12-01

    In recent years, there has been a rapid growth of location-based social networking services, such as Foursquare and Facebook, which have attracted an increasing number of users and greatly enriched their urban experience. Location-based social network data, as a new travel demand data source, seems to be an alternative or complement to survey data in the study of mobility behavior and activity analysis because of its relatively high access and low cost. In this paper, three OD estimation models have been utilized in order to investigate their relative performance when using Location-Based Social Networking (LBSN) data. For this, the Foursquare LBSN data was used to analyze the intra-urban movement behavioral patterns for the study area, Manhattan, the most densely populated of the five boroughs of New York city. The outputs of models are evaluated using real observations based on different criterions including distance distribution, destination travel constraints. The results demonstrate the promising potential of using LBSN data for urban travel demand analysis and monitoring.

  12. INTRA-URBAN MOVEMENT FLOW ESTIMATION USING LOCATION BASED SOCIAL NETWORKING DATA

    Directory of Open Access Journals (Sweden)

    A. Kheiri

    2015-12-01

    Full Text Available In recent years, there has been a rapid growth of location-based social networking services, such as Foursquare and Facebook, which have attracted an increasing number of users and greatly enriched their urban experience. Location-based social network data, as a new travel demand data source, seems to be an alternative or complement to survey data in the study of mobility behavior and activity analysis because of its relatively high access and low cost. In this paper, three OD estimation models have been utilized in order to investigate their relative performance when using Location-Based Social Networking (LBSN data. For this, the Foursquare LBSN data was used to analyze the intra-urban movement behavioral patterns for the study area, Manhattan, the most densely populated of the five boroughs of New York city. The outputs of models are evaluated using real observations based on different criterions including distance distribution, destination travel constraints. The results demonstrate the promising potential of using LBSN data for urban travel demand analysis and monitoring.

  13. Trans-European transport networks and urban systems in European Union

    Directory of Open Access Journals (Sweden)

    Maksin-Mićić Marija

    2003-01-01

    Full Text Available The trans-European transport network has different effects at interregional macro-regional and mezzo-regional level, and its effectiveness rises at the lower regional levels. Possible approaches to the trans-European transport network impact and effect survey and policy options have been pointed out. In that respect the brief review of survies, strategic framework and policies in European Union has been given. The importance of increased accessibility and mobility for regional expansion and for more balanced and polycentric system of city networks has been underlined. The question is how the new major transport infrastructure affects the development of functional complementarity between cities and regions. The new trans-European or major transport infrastructure does not per se create regional and urban system network development, although it can affect the conditions for the processes that create growth and development. The effects can be increased by co-ordination of measures of regional and urban policy, land use, transport and other policies. The necessary measure is the introduction of spatial impact assessment as sectorial policy instrument for the large transport infrastructure projects.

  14. CO2 Urban Synthesis and Analysis ("CO2-USA") Network

    Science.gov (United States)

    Lin, J. C.; Hutyra, L.; Loughner, C.; Stein, A. F.; Lusk, K.; Mitchell, L.; Gately, C.; Wofsy, S. C.

    2017-12-01

    Emissions of carbon associated with cities comprise a large component of the anthropogenic source. A number of cities have announced plans to reduce greenhouse gas emissions, but the scientific knowledge to quantitatively track emissions and assess the efficacy of mitigation is lacking. As the global population increasingly resides in urban regions, scientific knowledge about how much, where, and why a particular city emits carbon becomes increasingly important. To address this gap, researchers have initiated studies of carbon emissions and cycling in several U.S. cities, making it timely to develop a collaborative network to exchange information on community standards and common measurements, facilitate data sharing, and create analysis frameworks and cross-city syntheses to catalyze a new generation of researchers and enable new collaborations tackling important objectives that are difficult to address in isolation. We describe initial results from an incipient network focusing initially on cities in the U.S. with low barriers of entry that entrains a cross-section of U.S. urban centers with varying characteristics: size, population density, vegetation, urban form, infrastructure, development rates, climate, and meteorological patterns. Results will be reported that emerge from an initial workshop covering data harmonization & integration, inventory comparison, stakeholder outreach, network design, inverse modeling, and collaboration.

  15. Trans-European transport networks influence on the regional development and urban systems: Serbian experience

    Directory of Open Access Journals (Sweden)

    Maksin-Mićić Marija

    2004-01-01

    Full Text Available The trans-European transport network has different effects at macro-regional, mezzo-regional and micro-regional level, and on urban systems development, and its effectiveness rises at the lower regional levels. Possible approaches to the trans-European transport network impact and effect survey and policy options have been pointed out. The importance of increased accessibility and mobility for regional expansion and for more balanced and polycentric system of city networks has been underlined. The question is how the new major transport infrastructure affects the development of functional complementarity between cities and regions. Changes of the spatial organization, utilization and structure of cities, as well as of social benefits and losses subsequent to impacts of trans-European transport corridor "X" on urban system Ćuprija-Jagodina-Paraćin at section Belgrade-Nis have been analysed. The new trans-European or major transport infrastructure does not per se create regional and urban system network development, although it can affect the conditions for the processes that create growth and development. The effects can be increased by co-ordination of measures of regional and urban policy, land use, transport and other policies. The guidances and options of urban systems and urban centres development policies in trans-European transport corridor, as well as possibilities to improve our planning system have been given. The necessary measure is the introduction of spatial impact assessment as sectorial policy instrument for the large transport infrastructure projects.

  16. Hydrologic performance of bioretention in an expressway service area.

    Science.gov (United States)

    Gao, Jianping; Pan, Junkui; Hu, Ning; Xie, Chengzuo

    2018-04-01

    Bioretention can be an effective measure for stormwater treatment. However, there is a lack of systematic analysis of the impact of bioretention design parameters on hydrologic performance. Herein, SWMM and RECARGA models were applied to generate the typical annual rainfall runoff and simulate the water balance of the bioretention system in an expressway service area. The purpose of the investigation was to identify key design parameters for the bioretention system and delineate the priorities in developing the design. Results showed that the average groundwater recharge ratios for bioretention basins with and without an underdrain were 58.29% and 92.27%, respectively, the average overflow ratios were 4.13% and 4.19%, the average evapotranspiration ratios were 4.48% and 4.47%, and the average outflow ratio for bioretention with an underdrain was 33.94%. The ratio of the bioretention area to drainage area, and the saturated infiltration rates of planting soil and native soil were the main factors influencing water balance, while the underdrain diameter and gravel layer depth exerted little effect. Based on the impact analysis, multivariate nonlinear regression models of runoff reduction rate for two types of bioretention basin were established, which both exhibited high determination coefficients and acceptable Nash-Sutcliffe coefficients.

  17. Internet use among urban Malaysians: Network diversity effects

    Directory of Open Access Journals (Sweden)

    De Rycker Antoon

    2017-01-01

    Full Text Available This study examines social network diversity in urban areas relative to residents’ usage of information and communication technologies (ICTs. Individual-level variation in social network diversity was measured using position generator data collected as part of a survey conducted in Malaysia’s Klang Valley (N = 808. Regression analyses were performed to assess the extent to which network diversity is related to ICTs. We find that most ICTs have a negative effect on diversity. Only frequent use of the Internet at work, mobile access to the Internet, and reading online news or blogs contribute positively to diversity. Findings support both a tendency toward ‘networked individualism’ and the more recent ‘glocalization’ thesis that some ICTs may also afford participation within local space rather than only across distant space.

  18. Lessons learned on solar powered wireless sensor network deployments in urban, desert environments

    KAUST Repository

    Dehwah, Ahmad H.

    2015-05-01

    The successful deployment of a large scale solar powered wireless sensor network in an urban, desert environment is a very complex task. Specific cities of such environments cause a variety of operational problems, ranging from hardware faults to operational challenges, for instance due to the high variability of solar energy availability. Even a seemingly functional sensor network created in the lab does not guarantee reliable long term operation, which is absolutely necessary given the cost and difficulty of accessing sensor nodes in urban environments. As part of a larger traffic flow wireless sensor network project, we conducted several deployments in the last two years to evaluate the long-term performance of solar-powered urban wireless sensor networks in a desert area. In this article, we share our experiences in all domains of sensor network operations, from the conception of hardware to post-deployment analysis, including operational constraints that directly impact the software that can be run. We illustrate these experiences using numerous experimental results, and present multiple unexpected operational problems as well as some possible solutions to address them. We also show that current technology is far from meeting all operational constraints for these demanding applications, in which sensor networks are to operate for years to become economically appealing.

  19. Mental Health, School Problems, and Social Networks: Modeling Urban Adolescent Substance Use

    Science.gov (United States)

    Mason, Michael J.

    2010-01-01

    This study tested a mediation model of the relationship with school problems, social network quality, and substance use with a primary care sample of 301 urban adolescents. It was theorized that social network quality (level of risk or protection in network) would mediate the effects of school problems, accounting for internalizing problems and…

  20. Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks.

    Science.gov (United States)

    Artuñedo, Antonio; Del Toro, Raúl M; Haber, Rodolfo E

    2017-04-26

    Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller ( TLC ) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks.

  1. Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks

    Directory of Open Access Journals (Sweden)

    Antonio Artuñedo

    2017-04-01

    Full Text Available Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks.

  2. OUT-OF-SCHOOL EDUCATIONAL INSTITUTIONS NETWORK AS THE PART OF URBAN SUSTEM

    Directory of Open Access Journals (Sweden)

    MERYLOVA I. O.

    2017-02-01

    Full Text Available Summary. Formulation of the problem. Abstract. Formulation of the problem. The solution of urban development problems of an extensive and accessible network of out-of-school educational institutions, the formation of proposals for the placement of out-of-school institutions in the structure of the building and functional and planning features of the organization of territories of out-of-school institutions has systemically character. The system approach involves studying not only the internal functional structure of the territory, buildings and structures, but also the analysis of the connections of out-of-school institutions with all urban buildings, with industrial enterprises and research organizations, with a network of public service institutions and with other educational establishments. Article purpose: to analyze theoretical research in the field of urban planning, which should be taken into account when developing principles and methods for optimizing the network of out-of-school educational institutions. Conclusions. The research found that the systematic approach implies relation of out-of-school educational institutions with all urban environment, as well as with industrial enterprises and research organizations, with a network of public service institutions and, most importantly, with other educational establishments. The formation of a network of out-of-school educational institutions directly depends on the tendency of the development of social-pedagogical programs and the reform of the educational sector as a whole. The main system properties of a network of out-of-school educational institutions were determined. It was found that the cooperation of the resources of out-of-school and general education institutions is one of the effective ways to develop continuing education. In the state programs of educational reform is noted that the cooperation of the resources between the out-of-school institutions and general educational

  3. Spatiotemporal responses of dengue fever transmission to the road network in an urban area.

    Science.gov (United States)

    Li, Qiaoxuan; Cao, Wei; Ren, Hongyan; Ji, Zhonglin; Jiang, Huixian

    2018-07-01

    Urbanization is one of the important factors leading to the spread of dengue fever. Recently, some studies found that the road network as an urbanization factor affects the distribution and spread of dengue epidemic, but the study of relationship between the distribution of dengue epidemic and road network is limited, especially in highly urbanized areas. This study explores the temporal and spatial spread characteristics of dengue fever in the distribution of road network by observing a dengue epidemic in the southern Chinese cities. Geographic information technology is used to extract the spatial location of cases and explore the temporal and spatial changes of dengue epidemic and its spatial relationship with road network. The results showed that there was a significant "severe" period in the temporal change of dengue epidemic situation, and the cases were mainly concentrated in the vicinity of narrow roads, the spread of the epidemic mainly along the high-density road network area. These results show that high-density road network is an important factor to the direction and scale of dengue epidemic. This information may be helpful to the development of related epidemic prevention and control strategies. Copyright © 2018. Published by Elsevier B.V.

  4. ON THE MANAGEMENT OF URBAN ELECTRIC NETWORKS IN THE CONDITIONS OF THE SMART GRID

    Directory of Open Access Journals (Sweden)

    M. А. Fursanov

    2018-01-01

    Full Text Available The issues of prospective operation of the city electric networks in the conditions of the MART GRID, which will be quite different as compared to the traditional understanding and approaches, are under consideration. This requires the selection and application of appropriate analytical criteria and approaches to assessment, analysis and control of the networks. With this regard the following criteria are recommended: in a particular case – the optimal (minimal technological electric power consumption (losses, while in general – economically reasonable (minimal cost value of electric power transmission. It should be also borne in mind that contemporary urban networks are actively saturated with distributed sources of small generation that have radically changed the structure of electrical networks; therefore, account for such sources is an absolutely necessary objective of management regimes of urban electric networks, both traditional and in associated with the SMART GRID. A case of the analysis and control of urban electric 10 kV networks with distributed small sources of generation has been developed and presented according to the theoretical criterion of minimum relative active power losses in the circuit as a control case. The conducted research makes it possible to determine the magnitude of the tolerance network mode from the point of the theoretical minimum. 

  5. Space evolution model and empirical analysis of an urban public transport network

    Science.gov (United States)

    Sui, Yi; Shao, Feng-jing; Sun, Ren-cheng; Li, Shu-jing

    2012-07-01

    This study explores the space evolution of an urban public transport network, using empirical evidence and a simulation model validated on that data. Public transport patterns primarily depend on traffic spatial-distribution, demands of passengers and expected utility of investors. Evolution is an iterative process of satisfying the needs of passengers and investors based on a given traffic spatial-distribution. The temporal change of urban public transport network is evaluated both using topological measures and spatial ones. The simulation model is validated using empirical data from nine big cities in China. Statistical analyses on topological and spatial attributes suggest that an evolution network with traffic demands characterized by power-law numerical values which distribute in a mode of concentric circles tallies well with these nine cities.

  6. Dendritic Connectivity, Heterogeneity, and Scaling in Urban Stormwater Networks: Implications for Socio-Hydrology

    Science.gov (United States)

    Mejia, A.; Jovanovic, T.; Hale, R. L.; Gironas, J. A.

    2017-12-01

    Urban stormwater networks (USNs) are unique dendritic (tree-like) structures that combine both artificial (e.g., swales and pipes) and natural (e.g., streams and wetlands) components. They are central to stream ecosystem structure and function in urban watersheds. The emphasis of conventional stormwater management, however, has been on localized, temporal impacts (e.g., changes to hydrographs at discrete locations), and the performance of individual stormwater control measures. This is the case even though control measures are implemented to prevent impacts on the USN. We develop a modeling approach to retrospectively study hydrological fluxes and states in USNs and apply the model to an urban watershed in Scottsdale, Arizona, USA. Using outputs from the model, we analyze over space and time the network properties of dendritic connectivity, heterogeneity, and scaling. Results show that as the network growth over time, due to increasing urbanization, it tends to become more homogenous in terms of topological features but increasingly heterogeneous in terms of dynamic features. We further use the modeling results to address socio-hydrological implications for USNs. We find that the adoption over time of evolving management strategies (e.g., widespread implementation of vegetated swales and retention ponds versus pipes) may be locally beneficial to the USN but benefits may not propagate systematically through the network. The latter can be reinforced by sudden, perhaps unintended, changes to the overall dendritic connectivity.

  7. Limited urban growth: London's street network dynamics since the 18th century.

    Directory of Open Access Journals (Sweden)

    A Paolo Masucci

    Full Text Available We investigate the growth dynamics of Greater London defined by the administrative boundary of the Greater London Authority, based on the evolution of its street network during the last two centuries. This is done by employing a unique dataset, consisting of the planar graph representation of nine time slices of Greater London's road network spanning 224 years, from 1786 to 2010. Within this time-frame, we address the concept of the metropolitan area or city in physical terms, in that urban evolution reveals observable transitions in the distribution of relevant geometrical properties. Given that London has a hard boundary enforced by its long standing green belt, we show that its street network dynamics can be described as a fractal space-filling phenomena up to a capacitated limit, whence its growth can be predicted with a striking level of accuracy. This observation is confirmed by the analytical calculation of key topological properties of the planar graph, such as the topological growth of the network and its average connectivity. This study thus represents an example of a strong violation of Gibrat's law. In particular, we are able to show analytically how London evolves from a more loop-like structure, typical of planned cities, toward a more tree-like structure, typical of self-organized cities. These observations are relevant to the discourse on sustainable urban planning with respect to the control of urban sprawl in many large cities which have developed under the conditions of spatial constraints imposed by green belts and hard urban boundaries.

  8. Limited urban growth: London's street network dynamics since the 18th century.

    Science.gov (United States)

    Masucci, A Paolo; Stanilov, Kiril; Batty, Michael

    2013-01-01

    We investigate the growth dynamics of Greater London defined by the administrative boundary of the Greater London Authority, based on the evolution of its street network during the last two centuries. This is done by employing a unique dataset, consisting of the planar graph representation of nine time slices of Greater London's road network spanning 224 years, from 1786 to 2010. Within this time-frame, we address the concept of the metropolitan area or city in physical terms, in that urban evolution reveals observable transitions in the distribution of relevant geometrical properties. Given that London has a hard boundary enforced by its long standing green belt, we show that its street network dynamics can be described as a fractal space-filling phenomena up to a capacitated limit, whence its growth can be predicted with a striking level of accuracy. This observation is confirmed by the analytical calculation of key topological properties of the planar graph, such as the topological growth of the network and its average connectivity. This study thus represents an example of a strong violation of Gibrat's law. In particular, we are able to show analytically how London evolves from a more loop-like structure, typical of planned cities, toward a more tree-like structure, typical of self-organized cities. These observations are relevant to the discourse on sustainable urban planning with respect to the control of urban sprawl in many large cities which have developed under the conditions of spatial constraints imposed by green belts and hard urban boundaries.

  9. A Mobile Sensor Network to Map CO2 in Urban Environments

    Science.gov (United States)

    Lee, J.; Christen, A.; Nesic, Z.; Ketler, R.

    2014-12-01

    Globally, an estimated 80% of all fuel-based CO2 emissions into the atmosphere are attributable to cities, but there is still a lack of tools to map, visualize and monitor emissions to the scales at which emissions reduction strategies can be implemented - the local and urban scale. Mobile CO2 sensors, such as those attached to taxis and other existing mobile platforms, may be a promising way to observe and map CO2 mixing ratios across heterogenous urban environments with a limited number of sensors. Emerging modular open source technologies, and inexpensive compact sensor components not only enable rapid prototyping and replication, but also are allowing for the miniaturization and mobilization of traditionally fixed sensor networks. We aim to optimize the methods and technologies for monitoring CO2 in cities using a network of CO2 sensors deployable on vehicles and bikes. Our sensor technology is contained in a compact weather-proof case (35.8cm x 27.8cm x 11.8cm), powered independently by battery or by car, and includes the Li-Cor Li-820 infrared gas analyzer (Licor Inc, lincoln, NB, USA), Arduino Mega microcontroller (Arduino CC, Italy) and Adafruit GPS (Adafruit Technologies, NY, USA), and digital air temperature thermometer which measure CO2 mixing ratios (ppm), geolocation and speed, pressure and temperature, respectively at 1-second intervals. With the deployment of our sensor technology, we will determine if such a semi-autonomous mobile approach to monitoring CO2 in cities can determine excess urban CO2 mixing ratios (i.e. the 'urban CO2 dome') when compared to values measured at a fixed, remote background site. We present results from a pilot study in Vancouver, BC, where the a network of our new sensors was deployed both in fixed network and in a mobile campaign and examine the spatial biases of the two methods.

  10. Disruption and adaptation of urban transport networks from flooding

    Directory of Open Access Journals (Sweden)

    Pregnolato Maria

    2016-01-01

    Full Text Available Transport infrastructure networks are increasingly vulnerable to disruption from extreme rainfall events due to increasing surface water runoff from urbanization and changes in climate. Impacts from such disruptions typically extend far beyond the flood footprint, because of the interconnection and spatial extent of modern infrastructure. An integrated flood risk assessment couples high resolution information on depth and velocity from the CityCAT urban flood model with empirical analysis of vehicle speeds in different depths of flood water, to perturb a transport accessibility model and determine the impact of a given event on journey times across the urban area. A case study in Newcastle-upon-Tyne (UK shows that even minor flooding associate with a 1 in 10 year event can cause traffic disruptions of nearly half an hour. Two adaptation scenarios are subsequently tested (i hardening (i.e. flood protection a single major junction, (ii introduction of green roofs across all buildings. Both options have benefits in terms of reduced disruption, but for a 1 in 200 year event greening all roofs in the city provided only three times the benefit of protecting one critical road junction, highlighting the importance of understanding network attributes such as capacity and flows.

  11. Monitoring travel times in an urban network using video, GPS and Bluetooth

    NARCIS (Netherlands)

    Jie, L.; Van Zuylen, H.J.; Chunhua, L.; Shoufeng, L.

    2011-01-01

    The travel time is an important measure for the quality of traffic. This paper discusses a few methods to measure or estimate the travel time in urban road networks. First of all, it is important to know that urban travel times display a large variation, so that the measurement of a single (average)

  12. Urban Ecological Stewardship: Understanding the Structure, Function and Network of Community-based Urban Land Management

    Directory of Open Access Journals (Sweden)

    Lindsay K. Campbell

    2008-01-01

    Full Text Available Urban environmental stewardship activities are on the rise in cities throughout the Northeast. Groups participating in stewardship activities range in age, size, and geography and represent an increasingly complex and dynamic arrangement of civil society, government and business sectors. To better understand the structure, function and network of these community-based urban land managers, an assessment was conducted in 2004 by the research subcommittee of the Urban Ecology Collaborative. The goal of the assessment was to better understand the role of stewardship organizations engaged in urban ecology initiatives in selected major cities in the Northeastern U.S.: Boston, New Haven, New York City, Pittsburgh, Baltimore, and Washington, D.C. A total of 135 active organizations participated in this assessment. Findings include the discovery of a dynamic social network operating within cities, and a reserve of social capital and expertise that could be better utilized. Although often not the primary land owner, stewardship groups take an increasingly significant responsibility for a wide range of land use types including street and riparian corridors, vacant lots, public parks and gardens, green roofs, etc. Responsibilities include the delivery of public programs as well as daily maintenance and fundraising support. While most of the environmental stewardship organizations operate on staffs of zero or fewer than ten, with small cohorts of community volunteers, there is a significant difference in the total amount of program funding. Nearly all respondents agree that committed resources are scarce and insufficient with stewards relying upon and potentially competing for individual donations, local foundations, and municipal support. This makes it a challenge for the groups to grow beyond their current capacity and to develop long-term programs critical to resource management and education. It also fragments groups, making it difficult for planners and

  13. Networks Versus Need: Drivers of Urban Out-Migration in the Brazilian Amazon.

    Science.gov (United States)

    Randell, Heather F; VanWey, Leah K

    2014-12-01

    As urbanization rates rise globally, it becomes increasingly important to understand the factors associated with urban out-migration. In this paper, we examine the drivers of urban out-migration among young adults in two medium-sized cities in the Brazilian Amazon-Altamira and Santarém-focusing on the roles of social capital, human capital, and socioeconomic deprivation. Using household survey data from 1,293 individuals in the two cities, we employ an event history model to assess factors associated with migration and a binary logit model to understand factors associated with remitting behavior. We find that in Altamira, migration tends to be an individual-level opportunistic strategy fostered by extra-local family networks, while in Santarém, migration tends to be a household-level strategy driven by socioeconomic deprivation and accompanied by remittances. These results indicate that urban out-migration in Brazil is a diverse social process, and that the relative roles of extra-local networks versus economic need can function quite differently between geographically proximate but historically and socioeconomically distinct cities.

  14. Urban MEMS based seismic network for post-earthquakes rapid disaster assessment

    Science.gov (United States)

    D'Alessandro, Antonino; Luzio, Dario; D'Anna, Giuseppe

    2014-05-01

    Life losses following disastrous earthquake depends mainly by the building vulnerability, intensity of shaking and timeliness of rescue operations. In recent decades, the increase in population and industrial density has significantly increased the exposure to earthquakes of urban areas. The potential impact of a strong earthquake on a town center can be reduced by timely and correct actions of the emergency management centers. A real time urban seismic network can drastically reduce casualties immediately following a strong earthquake, by timely providing information about the distribution of the ground shaking level. Emergency management centers, with functions in the immediate post-earthquake period, could be use this information to allocate and prioritize resources to minimize loss of human life. However, due to the high charges of the seismological instrumentation, the realization of an urban seismic network, which may allow reducing the rate of fatalities, has not been achieved. Recent technological developments in MEMS (Micro Electro-Mechanical Systems) technology could allow today the realization of a high-density urban seismic network for post-earthquakes rapid disaster assessment, suitable for the earthquake effects mitigation. In the 1990s, MEMS accelerometers revolutionized the automotive-airbag system industry and are today widely used in laptops, games controllers and mobile phones. Due to their great commercial successes, the research into and development of MEMS accelerometers are actively pursued around the world. Nowadays, the sensitivity and dynamics of these sensors are such to allow accurate recording of earthquakes with moderate to strong magnitude. Due to their low cost and small size, the MEMS accelerometers may be employed for the realization of high-density seismic networks. The MEMS accelerometers could be installed inside sensitive places (high vulnerability and exposure), such as schools, hospitals, public buildings and places of

  15. Urban ecological stewardship: understanding the structure, function and network of community-based urban land management

    Science.gov (United States)

    Erika s. Svendsen; Lindsay K. Campbell

    2008-01-01

    Urban environmental stewardship activities are on the rise in cities throughout the Northeast. Groups participating in stewardship activities range in age, size, and geography and represent an increasingly complex and dynamic arrangement of civil society, government and business sectors. To better understand the structure, function and network of these community-based...

  16. Research on the network structure of the urban economic ties in Shanghai

    Directory of Open Access Journals (Sweden)

    CHEN Wenyan

    2015-04-01

    Full Text Available Assessing the network structure of the urban economic ties (NSUET of a city can help us understand its development level.Using the gravity model,the social network analysis method and the Arcgis tool,this paper has done some researches about the NSUET in Shanghai.The research results show that the NSUET in Shanghai was improved gradually from 2000 to 2010 and is in a stable status now.In the future,the NSUET in Shanghai should be adjusted to meet the need of urban development;the more focuses should be placed on the districts with better infrastructure,while the other areas are also considered to develop the NSUET.

  17. The carbon commute: Effects of urbanization on dissolved organic carbon quality on a suburban New England river network

    Science.gov (United States)

    Balch, E.; Robison, A.; Wollheim, W. M.

    2017-12-01

    Understanding anthropogenic influence on the sources and fluxes of carbon is necessary for interpreting the carbon cycle and contaminant transport throughout a river system. As urbanization increases worldwide, it is critical to understand how urbanization affects the carbon cycle so that we may be able to predict future changes. Rivers act as both transporters of terrestrial dissolved organic carbon (DOC) to coastal regions, and active transformers of DOC. The character (lability) of the carbon found within a river network is influenced by its sources and fluxes, as determined by the ecological processes, land use, and discharge, which vary throughout the network. We have characterized DOC quantity and quality throughout a suburban New England river network (Ipswich River, MA) in an attempt to provide a detailed picture of how DOC quality varies within a network, and how urbanization influences these changes. We conducted a synoptic survey of 45 sites over two hydrologically similar days in the Ipswich River network in northeast Massachusetts, USA. We collected discrete grab samples for DOC quantity and quality analyses. We also collected dissolved oxygen, conductivity, and nutrients (major anions and cations) as an extension of the synoptic survey. We plan to determine the source of the DOC by using excitation-emission matrices (EEMs), and specific UV absorption (SUVA) at 254 nm. These analyses will provide us with a detailed picture of how DOC quality varies within a network, and how urbanization influences these changes. Using land use data of the Ipswich River watershed, we are able to model the changes in DOC quality throughout the network. In highly urbanized headwaters, through the progressively more forested and wetland dominated main stem reaches, we expect to see the imprint of urbanization throughout the network due to its decreased lability. Studying the imprint of urbanization on DOC throughout a river network helps us complete our understanding of

  18. Estimating Urban Traffic Patterns through Probabilistic Interconnectivity of Road Network Junctions.

    Directory of Open Access Journals (Sweden)

    Ed Manley

    Full Text Available The emergence of large, fine-grained mobility datasets offers significant opportunities for the development and application of new methodologies for transportation analysis. In this paper, the link between routing behaviour and traffic patterns in urban areas is examined, introducing a method to derive estimates of traffic patterns from a large collection of fine-grained routing data. Using this dataset, the interconnectivity between road network junctions is extracted in the form of a Markov chain. This representation encodes the probability of the successive usage of adjacent road junctions, encoding routes as flows between decision points rather than flows along road segments. This network of functional interactions is then integrated within a modified Markov chain Monte Carlo (MCMC framework, adapted for the estimation of urban traffic patterns. As part of this approach, the data-derived links between major junctions influence the movement of directed random walks executed across the network to model origin-destination journeys. The simulation process yields estimates of traffic distribution across the road network. The paper presents an implementation of the modified MCMC approach for London, United Kingdom, building an MCMC model based on a dataset of nearly 700000 minicab routes. Validation of the approach clarifies how each element of the MCMC framework contributes to junction prediction performance, and finds promising results in relation to the estimation of junction choice and minicab traffic distribution. The paper concludes by summarising the potential for the development and extension of this approach to the wider urban modelling domain.

  19. Vulnerability analysis and passenger source prediction in urban rail transit networks.

    Directory of Open Access Journals (Sweden)

    Junjie Wang

    Full Text Available Based on large-scale human mobility data collected in San Francisco and Boston, the morning peak urban rail transit (URT ODs (origin-destination matrix were estimated and the most vulnerable URT segments, those capable of causing the largest service interruptions, were identified. In both URT networks, a few highly vulnerable segments were observed. For this small group of vital segments, the impact of failure must be carefully evaluated. A bipartite URT usage network was developed and used to determine the inherent connections between urban rail transits and their passengers' travel demands. Although passengers' origins and destinations were easy to locate for a large number of URT segments, a few show very complicated spatial distributions. Based on the bipartite URT usage network, a new layer of the understanding of a URT segment's vulnerability can be achieved by taking the difficulty of addressing the failure of a given segment into account. Two proof-of-concept cases are described here: Possible transfer of passenger flow to the road network is here predicted in the cases of failures of two representative URT segments in San Francisco.

  20. Topological patterns in street networks of self-organized urban settlements

    Science.gov (United States)

    Buhl, J.; Gautrais, J.; Reeves, N.; Solé, R. V.; Valverde, S.; Kuntz, P.; Theraulaz, G.

    2006-02-01

    Many urban settlements result from a spatially distributed, decentralized building process. Here we analyze the topological patterns of organization of a large collection of such settlements using the approach of complex networks. The global efficiency (based on the inverse of shortest-path lengths), robustness to disconnections and cost (in terms of length) of these graphs is studied and their possible origins analyzed. A wide range of patterns is found, from tree-like settlements (highly vulnerable to random failures) to meshed urban patterns. The latter are shown to be more robust and efficient.

  1. Dispersion of a Passive Scalar Within and Above an Urban Street Network

    Science.gov (United States)

    Goulart, E. V.; Coceal, O.; Belcher, S. E.

    2018-03-01

    The transport of a passive scalar from a continuous point-source release in an urban street network is studied using direct numerical simulation (DNS). Dispersion through the network is characterized by evaluating horizontal fluxes of scalar within and above the urban canopy and vertical exchange fluxes through the canopy top. The relative magnitude and balance of these fluxes are used to distinguish three different regions relative to the source location: a near-field region, a transition region and a far-field region. The partitioning of each of these fluxes into mean and turbulent parts is computed. It is shown that within the canopy the horizontal turbulent flux in the street network is small, whereas above the canopy it comprises a significant fraction of the total flux. Vertical fluxes through the canopy top are predominantly turbulent. The mean and turbulent fluxes are respectively parametrized in terms of an advection velocity and a detrainment velocity and the parametrization incorporated into a simple box-network model. The model treats the coupled dispersion problem within and above the street network in a unified way and predictions of mean concentrations compare well with the DNS data. This demonstrates the usefulness of the box-network approach for process studies and interpretation of results from more detailed numerical simulations.

  2. Assessing urban strategies for reducing the impacts of extreme weather on infrastructure networks.

    Science.gov (United States)

    Pregnolato, Maria; Ford, Alistair; Robson, Craig; Glenis, Vassilis; Barr, Stuart; Dawson, Richard

    2016-05-01

    Critical infrastructure networks, including transport, are crucial to the social and economic function of urban areas but are at increasing risk from natural hazards. Minimizing disruption to these networks should form part of a strategy to increase urban resilience. A framework for assessing the disruption from flood events to transport systems is presented that couples a high-resolution urban flood model with transport modelling and network analytics to assess the impacts of extreme rainfall events, and to quantify the resilience value of different adaptation options. A case study in Newcastle upon Tyne in the UK shows that both green roof infrastructure and traditional engineering interventions such as culverts or flood walls can reduce transport disruption from flooding. The magnitude of these benefits depends on the flood event and adaptation strategy, but for the scenarios considered here 3-22% improvements in city-wide travel times are achieved. The network metric of betweenness centrality, weighted by travel time, is shown to provide a rapid approach to identify and prioritize the most critical locations for flood risk management intervention. Protecting just the top ranked critical location from flooding provides an 11% reduction in person delays. A city-wide deployment of green roofs achieves a 26% reduction, and although key routes still flood, the benefits of this strategy are more evenly distributed across the transport network as flood depths are reduced across the model domain. Both options should form part of an urban flood risk management strategy, but this method can be used to optimize investment and target limited resources at critical locations, enabling green infrastructure strategies to be gradually implemented over the longer term to provide city-wide benefits. This framework provides a means of prioritizing limited financial resources to improve resilience. This is particularly important as flood management investments must typically exceed

  3. Artificial neural networks as a tool in urban storm drainage

    DEFF Research Database (Denmark)

    Loke, E.; Warnaars, E.A.; Jacobsen, P.

    1997-01-01

    The introduction of Artificial Neural Networks (ANNs) as a tool in the field of urban storm drainage is discussed. Besides some basic theory on the mechanics of ANNs and a general classification of the different types of ANNs, two ANN application examples are presented: The prediction of runoff...

  4. A Long-Term Tourism Strategy within a Networked Urban Regeneration Process for Historical Quarters

    Directory of Open Access Journals (Sweden)

    Han Jie

    2012-12-01

    Full Text Available During 1970s, the de-industrialization in many western countries caused large unemployment and decay of industrial cities. Accordingly, as an urban revitalization strategy, tourism was initiated in many urban historical quarters to revitalize the economy and to improve the decaying city image. Many de-industrialized cities witnessed the rise of place marketing-led tourism in historical quarters. Many quarters have removed and replaced the existing residents and original functions which were thought to convey negative images. Meanwhile, new images and attractions, including museums, crafts, arts, cultural heritage, and festivals have been introduced in these empty physical fabrics to attract investors and tourists. More recently, the strategy of tourism development tends to be closely related with other urban planning strategies, especially in historical quarters’ revitalization process, which usually link tourism with other development strategies such as cultural industry and creative industry (Tiesdell et al., 1996, Cunningham, 2002 to transform these quarters into cultural hubs or creative dismissions (Roodhouse, 2010, aiming to attract not only tourists but also local people, enhance the quarters’ cultural ambience, and promote local cultural production consumption without emptying all the residents and functions. In recent decades, many Chinese cities have experienced huge urban changes. With many urban historical quarters being demolished to gain development profits and new city image, many old neighbourhoods collapsed with their residents relocated to frontier areas. This paper conducts a comparative study on recent creative hub initiated by Shanghai government—Tianzi Fang and the Xi’an Muslim Quarter. It analyzes the recycling mode, the everyday life , the experience of uniqueness, and social network based on the two cases. It also explores the tensions, conflicts, and cooperation within the network of disciplines, governmental

  5. Eco-Polycentric Urban Systems: An Ecological Region Perspective for Network Cities

    Directory of Open Access Journals (Sweden)

    André Botequilha-Leitão

    2012-04-01

    Full Text Available The research presented in this paper is a work in progress. It provides linkages between the author’s earlier research under the sustainable land planning framework (SLP and emergent ideas and planning and design strategies, centered on the (landscape ecological dimension of cities’ sustainability. It reviews several concepts, paradigms, and metaphors that have been emerging during the last decade, which can contribute to expand our vision on city planning and design. Among other issues, city form—monocentric, polycentric, and diffused—is discussed. The hypothesis set forth is that cities can improve the pathway to sustainability by adopting intermediate, network urban forms such as polycentric urban systems (PUS under a broader vision (as compared to the current paradigm, to make way to urban ecological regions. It discusses how both the principles of SLP and those emergent ideas can contribute to integrate PUS with their functional hinterland, adopting an ecosystemic viewpoint of cities. It proposes to redirect the current dominant economic focus of PUS to include all of the other functions that are essential to urbanites, such as production (including the 3Rs, recreation, and ecology in a balanced way. Landscape ecology principles are combined with complexity science in order to deal with uncertainty to improve regional systems’ resilience. Cooperation in its multiple forms is seen as a fundamental social, but also economic process contributing to the urban network functioning, including its evolving capabilities for self-organization and adaptation.

  6. Risk analysis of urban gas pipeline network based on improved bow-tie model

    Science.gov (United States)

    Hao, M. J.; You, Q. J.; Yue, Z.

    2017-11-01

    Gas pipeline network is a major hazard source in urban areas. In the event of an accident, there could be grave consequences. In order to understand more clearly the causes and consequences of gas pipeline network accidents, and to develop prevention and mitigation measures, the author puts forward the application of improved bow-tie model to analyze risks of urban gas pipeline network. The improved bow-tie model analyzes accident causes from four aspects: human, materials, environment and management; it also analyzes the consequences from four aspects: casualty, property loss, environment and society. Then it quantifies the causes and consequences. Risk identification, risk analysis, risk assessment, risk control, and risk management will be clearly shown in the model figures. Then it can suggest prevention and mitigation measures accordingly to help reduce accident rate of gas pipeline network. The results show that the whole process of an accident can be visually investigated using the bow-tie model. It can also provide reasons for and predict consequences of an unfortunate event. It is of great significance in order to analyze leakage failure of gas pipeline network.

  7. [Scale effect of Nanjing urban green infrastructure network pattern and connectivity analysis.

    Science.gov (United States)

    Yu, Ya Ping; Yin, Hai Wei; Kong, Fan Hua; Wang, Jing Jing; Xu, Wen Bin

    2016-07-01

    Based on ArcGIS, Erdas, GuidosToolbox, Conefor and other software platforms, using morphological spatial pattern analysis (MSPA) and landscape connectivity analysis methods, this paper quantitatively analysed the scale effect, edge effect and distance effect of the Nanjing urban green infrastructure network pattern in 2013 by setting different pixel sizes (P) and edge widths in MSPA analysis, and setting different dispersal distance thresholds in landscape connectivity analysis. The results showed that the type of landscape acquired based on the MSPA had a clear scale effect and edge effect, and scale effects only slightly affected landscape types, whereas edge effects were more obvious. Different dispersal distances had a great impact on the landscape connectivity, 2 km or 2.5 km dispersal distance was a critical threshold for Nanjing. When selecting the pixel size 30 m of the input data and the edge wide 30 m used in the morphological model, we could get more detailed landscape information of Nanjing UGI network. Based on MSPA and landscape connectivity, analysis of the scale effect, edge effect, and distance effect on the landscape types of the urban green infrastructure (UGI) network was helpful for selecting the appropriate size, edge width, and dispersal distance when developing these networks, and for better understanding the spatial pattern of UGI networks and the effects of scale and distance on the ecology of a UGI network. This would facilitate a more scientifically valid set of design parameters for UGI network spatiotemporal pattern analysis. The results of this study provided an important reference for Nanjing UGI networks and a basis for the analysis of the spatial and temporal patterns of medium-scale UGI landscape networks in other regions.

  8. Measuring urban rainfall using microwave links from commercial cellular communication networks

    NARCIS (Netherlands)

    Overeem, A.; Leijnse, H.; Uijlenhoet, R.

    2011-01-01

    The estimation of rainfall using commercial microwave links is a new and promising measurement technique. Commercial link networks cover large parts of the land surface of the earth and have a high density, particularly in urban areas. Rainfall attenuates the electromagnetic signals transmitted

  9. Expressway construction in landslide areas. ; Construction work between Fujioka interchange and Saku interchange of Joshin'etsu expressway. Ugoku yama wo tsuranuku. ; Joshin'etsu Jidoshado Fujioka IC/Saku IC kan kensetsu koji

    Energy Technology Data Exchange (ETDEWEB)

    Togo, Y [Japan Highway Public Corp., Tokyo (Japan)

    1993-03-15

    The Joshin'etsu motorway is a 204km expressway. Various technological studies have been made for the remediation work for the 69.5km section which is opened to traffic this spring, because not only a series of tunnels, bridges, long cut and fill soil particular to mountain roads are included but also the section has many landslide areas. The length of the Higureyama tunnel is 2,314m. Although strong andesite is prevailing as the nature of the soil, the central area of the tunnel is consisted of brittle mudstone and self-crushing andesite with faults because the tunnel runs through the lower portion of a landslide zone. The mudstone is a squeezing ground, and buckling of H supporting, breakage of lock bolts, and damage of sprayed concrete occurred in many places. 2 years and 10 months are required for the construction of the tunnel. The average monthly drilling is only 10m/month which is an unprecedented case in tunnel excavation. Even limited to large-scale landslides, 13 occurrences are experienced. 10 figs., 1 tab.

  10. Airborne particle monitoring with urban closed-circuit television camera networks and a chromatic technique

    International Nuclear Information System (INIS)

    Kolupula, Y R; Jones, G R; Deakin, A G; Spencer, J W; Aceves-Fernandez, M A

    2010-01-01

    An economic approach for the preliminary assessment of 2–10 µm sized (PM10) airborne particle levels in urban areas is described. It uses existing urban closed-circuit television (CCTV) surveillance camera networks in combination with particle accumulating units and chromatic quantification of polychromatic light scattered by the captured particles. Methods for accommodating extraneous light effects are discussed and test results obtained from real urban sites are presented to illustrate the potential of the approach

  11. Characterisation of an urban bus network for environmental purposes.

    Science.gov (United States)

    André, Michel; Villanova, André

    2004-12-01

    Since pollutant emissions are closely related to the operating conditions of vehicles, their evaluation usually involves studying these operating conditions (through bus instrumentation and monitoring under actual operation), the design of representative driving or engine test cycles and the measurement of pollutant emissions. A preliminary characterisation of the routes on a bus network should make it possible to identify typical routes, the driving conditions and pollutant emissions of which are then studied. Two approaches are envisaged and applied to the Paris area, for which a wealth of information is available, which should be transferable to other bus networks. Both approaches are based on factorial analysis and automatic clustering, to allow optimum description and the identification of a pertinent typology of the bus routes in several classes. The first attempt at characterisation is based on statistics relating to bus operations: route characteristics (length, dedicated bus lanes, number of stops, location of stops: schools, tourist sites, hospitals, railways or underground stations), travel time, commercial speed, annual statistics (number of passengers, number of vehicles per hour, total kilometres), the irregularity of travel (variation of travel times, injuries, congestion.), as well as information on the problems encountered (congestion, distribution of the passenger load, junctions, bends). A second approach is based on the analysis of the "urban context" in which buses are driven. Population, employment, housing, road network, traffic and places that generate or disturb traffic (schools, railway stations, shopping areas, etc.) are calculated for the Ile de France region, by cells of 100 x 100 m, and collected in a geographical information system (GIS). Statistical analyses enable a typology of these urban cells to be established, the main parameters being density, type of housing, road types and traffic levels. The bus routes are then analysed

  12. Problem-Solving Methods for the Prospective Development of Urban Power Distribution Network

    Directory of Open Access Journals (Sweden)

    A. P. Karpenko

    2014-01-01

    Full Text Available This article succeeds the former A. P. K nko’ and A. I. Kuzmina’ ubl t on titled "A mathematical model of urban distribution electro-network considering its future development" (electronic scientific and technical magazine "Science and education" No. 5, 2014.The article offers a model of urban power distribution network as a set of transformer and distribution substations and cable lines. All elements of the network and new consumers are determined owing to vectors of parameters consistent with them.A problem of the urban power distribution network design, taking into account a prospective development of the city, is presented as a problem of discrete programming. It is in deciding on the optimal option to connect new consumers to the power supply network, on the number and sites to build new substations, and on the option to include them in the power supply network.Two methods, namely a reduction method for a set the nested tasks of global minimization and a decomposition method are offered to solve the problem.In reduction method the problem of prospective development of power supply network breaks into three subtasks of smaller dimension: a subtask to define the number and sites of new transformer and distribution substations, a subtask to define the option to connect new consumers to the power supply network, and a subtask to include new substations in the power supply network. The vector of the varied parameters is broken into three subvectors consistent with the subtasks. Each subtask is solved using an area of admissible vector values of the varied parameters at the fixed components of the subvectors obtained when solving the higher subtasks.In decomposition method the task is presented as a set of three, similar to reduction method, reductions of subtasks and a problem of coordination. The problem of coordination specifies a sequence of the subtasks solution, defines the moment of calculation termination. Coordination is realized by

  13. Using mobile probes to inform and measure the effectiveness of traffic control strategies on urban networks.

    Science.gov (United States)

    2015-07-01

    Urban traffic congestion is a problem that plagues many cities in the United States. Testing strategies to alleviate this : congestion is especially challenging due to the difficulty of modeling complex urban traffic networks. However, recent work ha...

  14. Robustness Assessment of Urban Road Network with Consideration of Multiple Hazard Events.

    Science.gov (United States)

    Zhou, Yaoming; Sheu, Jiuh-Biing; Wang, Junwei

    2017-08-01

    Robustness measures a system's ability of being insensitive to disturbances. Previous studies assessed the robustness of transportation networks to a single disturbance without considering simultaneously happening multiple events. The purpose of this article is to address this problem and propose a new framework to assess the robustness of an urban transportation network. The framework consists of two layers. The upper layer is to define the robustness index based on the impact evaluation in different scenarios obtained from the lower layer, whereas the lower layer is to evaluate the performance of each hypothetical disrupted road network given by the upper layer. The upper layer has two varieties, that is, robustness against random failure and robustness against intentional attacks. This robustness measurement framework is validated by application to a real-world urban road network in Hong Kong. The results show that the robustness of a transport network with consideration of multiple events is quite different from and more comprehensive than that with consideration of only a single disruption. We also propose a Monte Carlo method and a heuristic algorithm to handle different scenarios with multiple hazard events, which is proved to be quite efficient. This methodology can also be applied to conduct risk analysis of other systems where multiple failures or disruptions exist. © 2017 Society for Risk Analysis.

  15. Optimization of hydrometric monitoring network in urban drainage systems using information theory.

    Science.gov (United States)

    Yazdi, J

    2017-10-01

    Regular and continuous monitoring of urban runoff in both quality and quantity aspects is of great importance for controlling and managing surface runoff. Due to the considerable costs of establishing new gauges, optimization of the monitoring network is essential. This research proposes an approach for site selection of new discharge stations in urban areas, based on entropy theory in conjunction with multi-objective optimization tools and numerical models. The modeling framework provides an optimal trade-off between the maximum possible information content and the minimum shared information among stations. This approach was applied to the main surface-water collection system in Tehran to determine new optimal monitoring points under the cost considerations. Experimental results on this drainage network show that the obtained cost-effective designs noticeably outperform the consulting engineers' proposal in terms of both information contents and shared information. The research also determined the highly frequent sites at the Pareto front which might be important for decision makers to give a priority for gauge installation on those locations of the network.

  16. Species turnover and geographic distance in an urban river network

    DEFF Research Database (Denmark)

    Rouquette, James R.; Dallimer, Martin; Armsworth, Paul R.

    2013-01-01

    AimUnderstanding the relationships between species turnover, environmental features and the geographic distance between sites can provide important insights into the processes driving species diversity. This is particularly relevant where the effective distance between sites may be a function...... patterns of species turnover and to determine whether these patterns differ between different taxonomic groups. LocationSheffield area, UK. MethodsAquatic (macroinvertebrates, diatoms) and terrestrial (birds, plants, butterflies) organisms were surveyed at 41 sites across an urban river network. We...... of the geographic distance measures, although network distance remained significant for birds and some plant groups after removing the effect of environmental distance. Water-dispersed and neophyte plant groups were significantly related to network and flow distance. Main conclusionsThe results suggest that aquatic...

  17. Urban networks among Chinese cities along "the Belt and Road": A case of web search activity in cyberspace.

    Science.gov (United States)

    Zhang, Lu; Du, Hongru; Zhao, Yannan; Wu, Rongwei; Zhang, Xiaolei

    2017-01-01

    "The Belt and Road" initiative has been expected to facilitate interactions among numerous city centers. This initiative would generate a number of centers, both economic and political, which would facilitate greater interaction. To explore how information flows are merged and the specific opportunities that may be offered, Chinese cities along "the Belt and Road" are selected for a case study. Furthermore, urban networks in cyberspace have been characterized by their infrastructure orientation, which implies that there is a relative dearth of studies focusing on the investigation of urban hierarchies by capturing information flows between Chinese cities along "the Belt and Road". This paper employs Baidu, the main web search engine in China, to examine urban hierarchies. The results show that urban networks become more balanced, shifting from a polycentric to a homogenized pattern. Furthermore, cities in networks tend to have both a hierarchical system and a spatial concentration primarily in regions such as Beijing-Tianjin-Hebei, Yangtze River Delta and the Pearl River Delta region. Urban hierarchy based on web search activity does not follow the existing hierarchical system based on geospatial and economic development in all cases. Moreover, urban networks, under the framework of "the Belt and Road", show several significant corridors and more opportunities for more cities, particularly western cities. Furthermore, factors that may influence web search activity are explored. The results show that web search activity is significantly influenced by the economic gap, geographical proximity and administrative rank of the city.

  18. Urban networks among Chinese cities along "the Belt and Road": A case of web search activity in cyberspace.

    Directory of Open Access Journals (Sweden)

    Lu Zhang

    Full Text Available "The Belt and Road" initiative has been expected to facilitate interactions among numerous city centers. This initiative would generate a number of centers, both economic and political, which would facilitate greater interaction. To explore how information flows are merged and the specific opportunities that may be offered, Chinese cities along "the Belt and Road" are selected for a case study. Furthermore, urban networks in cyberspace have been characterized by their infrastructure orientation, which implies that there is a relative dearth of studies focusing on the investigation of urban hierarchies by capturing information flows between Chinese cities along "the Belt and Road". This paper employs Baidu, the main web search engine in China, to examine urban hierarchies. The results show that urban networks become more balanced, shifting from a polycentric to a homogenized pattern. Furthermore, cities in networks tend to have both a hierarchical system and a spatial concentration primarily in regions such as Beijing-Tianjin-Hebei, Yangtze River Delta and the Pearl River Delta region. Urban hierarchy based on web search activity does not follow the existing hierarchical system based on geospatial and economic development in all cases. Moreover, urban networks, under the framework of "the Belt and Road", show several significant corridors and more opportunities for more cities, particularly western cities. Furthermore, factors that may influence web search activity are explored. The results show that web search activity is significantly influenced by the economic gap, geographical proximity and administrative rank of the city.

  19. HOW TRAVEL DEMAND AFFECTS DETECTION OF NON-RECURRENT TRAFFIC CONGESTION ON URBAN ROAD NETWORKS

    Directory of Open Access Journals (Sweden)

    B. Anbaroglu

    2016-06-01

    Full Text Available Occurrence of non-recurrent traffic congestion hinders the economic activity of a city, as travellers could miss appointments or be late for work or important meetings. Similarly, for shippers, unexpected delays may disrupt just-in-time delivery and manufacturing processes, which could lose them payment. Consequently, research on non-recurrent congestion detection on urban road networks has recently gained attention. By analysing large amounts of traffic data collected on a daily basis, traffic operation centres can improve their methods to detect non-recurrent congestion rapidly and then revise their existing plans to mitigate its effects. Space-time clusters of high link journey time estimates correspond to non-recurrent congestion events. Existing research, however, has not considered the effect of travel demand on the effectiveness of non-recurrent congestion detection methods. Therefore, this paper investigates how travel demand affects detection of non-recurrent traffic congestion detection on urban road networks. Travel demand has been classified into three categories as low, normal and high. The experiments are carried out on London’s urban road network, and the results demonstrate the necessity to adjust the relative importance of the component evaluation criteria depending on the travel demand level.

  20. Return period curves for extreme 5-min rainfall amounts at the Barcelona urban network

    Science.gov (United States)

    Lana, X.; Casas-Castillo, M. C.; Serra, C.; Rodríguez-Solà, R.; Redaño, A.; Burgueño, A.; Martínez, M. D.

    2018-03-01

    Heavy rainfall episodes are relatively common in the conurbation of Barcelona and neighbouring cities (NE Spain), usually due to storms generated by convective phenomena in summer and eastern and south-eastern advections in autumn. Prevention of local flood episodes and right design of urban drainage have to take into account the rainfall intensity spread instead of a simple evaluation of daily rainfall amounts. The database comes from 5-min rain amounts recorded by tipping buckets in the Barcelona urban network along the years 1994-2009. From these data, extreme 5-min rain amounts are selected applying the peaks-over-threshold method for thresholds derived from both 95% percentile and the mean excess plot. The return period curves are derived from their statistical distribution for every gauge, describing with detail expected extreme 5-min rain amounts across the urban network. These curves are compared with those derived from annual extreme time series. In this way, areas in Barcelona submitted to different levels of flood risk from the point of view of rainfall intensity are detected. Additionally, global time trends on extreme 5-min rain amounts are quantified for the whole network and found as not statistically significant.

  1. Effect of watershed urbanization on N2O emissions from the Chongqing metropolitan river network, China

    Science.gov (United States)

    He, Yixin; Wang, Xiaofeng; Chen, Huai; Yuan, Xingzhong; Wu, Ning; Zhang, Yuewei; Yue, Junsheng; Zhang, Qiaoyong; Diao, Yuanbin; Zhou, Lilei

    2017-12-01

    Watershed urbanization, an integrated anthropogenic perturbation, is another considerable global concern in addition to that of global warming and may significantly enrich the N loadings of watersheds, which then greatly influences the nitrous oxide (N2O) production and fluxes of these aquatic systems. However, little is known about the N2O dynamics in human-dominated metropolitan river networks. In this study, we present the temporal and spatial variations in N2O saturation and emission in the Chongqing metropolitan river network, which is undergoing intensified urbanization. The N2O saturation and fluxes at 84 sampling sites ranged from 126% to 10536% and from 4.5 to 1566.8 μmol N2O m-2 d-1, with means of 1780% and 261 μmol N2O m-2 d-1. The riverine N2O saturation and fluxes increased along with the urbanization gradient and urbanization rate, with disproportionately higher values in urban rivers due to the N2O-rich sewage inputs and enriched in situ N substrates. We found a clear seasonal pattern of N2O saturation, which was co-regulated by both water temperature and precipitation. Regression analysis indicated that the N substrates and dissolved oxygen (DO) that controlled nitrogen metabolism acted as good predictors of the N2O emissions of urban river networks. Particularly, phosphorus (P) and hydromorphological factors (water velocity, river size and bottom substrate) had stronger relationships with the N2O saturation and could also be used to predict the N2O emission hotspots in regions with rapid urbanization. In addition, the default emission factors (EF5-r) used in the Intergovernmental Panel on Climate Change (IPCC) methodology may need revision given the differences among the physical and chemical factors in different rivers, especially urban rivers.

  2. Assessing and comparing relationships between urban environmental stewardship networks and land cover in Baltimore and Seattle

    Science.gov (United States)

    Michele Romolini; J. Morgan Grove; Dexter H. Locke

    2013-01-01

    Implementation of urban sustainability policies often requires collaborations between organizations across sectors. Indeed, it is commonly agreed that governance by environmental networks is preferred to individual organizations acting alone. Yet research shows that network structures vary widely, and that these variations can impact network effectiveness. However,...

  3. The role of “network of cities” in construction of global urban culture

    OpenAIRE

    Baycan-Levent, Tüzin; Kundak, Seda; Gülümser, Aliye Ahu

    2004-01-01

    The globalization process has led to an increased interaction between cities and to a new urban system/network in which they need to be competitive and complementary at the same time. “Network of cities”, such as World Cities, Eurocities or Sister Cities are among the well known examples of interaction and cooperation of the cities at the regional and global level. The cities of different regions and countries tend to share their experiences and their cultures within these networks in order t...

  4. Smart network expansion - (no) an issue for urban network operators. With hot spot analysis to smart grid; Smarter Netzausbau - (k)ein Thema fuer staedtische Netzbetreiber. Mit Hotspotanalyse zum Smart Grid

    Energy Technology Data Exchange (ETDEWEB)

    Safirov, Janko; Guarente, Andreas; Haas, Hans-Juergen [Stadtwerke Solingen Netz GmbH, Solingen (Germany); Ladermann, Alexander; Seeger, Nick; Fritz, Wolfgang [Consentec GmbH, Aachen (Germany)

    2013-04-29

    The ongoing construction of production facilities based on renewable energy sources in distribution networks has led to measures to reinforce power distribution systems with many network operators, or this occurs in the near future. Many areal network operators with extended network structures and often lower load in comparison to the installed generation capacity are in the focus of these developments. In contrast, it is frequently assumed for urban distribution networks that these are affected at most sporadic by measures to reinforce power distribution systems. However, basically also for urban network operators the question concerning the development of the supply task rises.

  5. Complex Network Theory Applied to the Growth of Kuala Lumpur's Public Urban Rail Transit Network.

    Science.gov (United States)

    Ding, Rui; Ujang, Norsidah; Hamid, Hussain Bin; Wu, Jianjun

    2015-01-01

    Recently, the number of studies involving complex network applications in transportation has increased steadily as scholars from various fields analyze traffic networks. Nonetheless, research on rail network growth is relatively rare. This research examines the evolution of the Public Urban Rail Transit Networks of Kuala Lumpur (PURTNoKL) based on complex network theory and covers both the topological structure of the rail system and future trends in network growth. In addition, network performance when facing different attack strategies is also assessed. Three topological network characteristics are considered: connections, clustering and centrality. In PURTNoKL, we found that the total number of nodes and edges exhibit a linear relationship and that the average degree stays within the interval [2.0488, 2.6774] with heavy-tailed distributions. The evolutionary process shows that the cumulative probability distribution (CPD) of degree and the average shortest path length show good fit with exponential distribution and normal distribution, respectively. Moreover, PURTNoKL exhibits clear cluster characteristics; most of the nodes have a 2-core value, and the CPDs of the centrality's closeness and betweenness follow a normal distribution function and an exponential distribution, respectively. Finally, we discuss four different types of network growth styles and the line extension process, which reveal that the rail network's growth is likely based on the nodes with the biggest lengths of the shortest path and that network protection should emphasize those nodes with the largest degrees and the highest betweenness values. This research may enhance the networkability of the rail system and better shape the future growth of public rail networks.

  6. Nonzero-Sum Relationships in Mitigating Urban Carbon Emissions: A Dynamic Network Simulation.

    Science.gov (United States)

    Chen, Shaoqing; Chen, Bin; Su, Meirong

    2015-10-06

    The "stove-pipe" way of thinking has been mostly used in mitigating carbon emissions and managing socioeconomics because of its convenience of implementation. However, systems-oriented approaches become imperative in pursuit of an efficient regulation of carbon emissions from systems as complicated as urban systems. The aim of this paper is to establish a dynamic network approach that is capable of assessing the effectiveness of carbon emissions mitigation in a more holistic way. A carbon metabolic network is constructed by modeling the carbon flows between economic sectors and environment. With the network shocked by interventions to the sectoral carbon flows, indirect emissions from the city are accounted for under certain carbon mitigation strategies. The nonzero-sum relationships between sectors and environmental components are identified based on utility analysis, which synthesize the nature of direct and indirect network interactions. The results of the case study of Beijing suggest that the stove-pipe mitigation strategies targeted the economic sectors might be not as efficient as they were expected. A direct cutting in material or energy import to the sectors may result in a rebound in indirect emissions and thus fails to achieve the carbon mitigation goal of the city as a whole. A promising way of foreseeing the dynamic mechanism of emissions is to analyze the nonzero-sum relationships between important urban components. Thinking cities as systems of interactions, the network approach is potentially a strong tool for appraising and filtering mitigation strategies of carbon emissions.

  7. Together we have fun: native-place networks and sexual risk behaviours among Chinese male rural-urban migrants.

    Science.gov (United States)

    Yang, Xiaozhao Yousef; Kelly, Brian C; Yang, Tingzhong

    2016-05-01

    Some scholars argue that the maintenance of social networks contributes to the lower prevalence of deviant behaviours and fewer adverse health effects among migrants. But others suggest that if migrants are embedded in homogeneous networks, such networks may enable the formation of a deviant subculture that promotes risk taking. Facing this dilemma, the present study investigates how native-place networks influence sexual risk behaviours (SRBs), specifically the pursuit of commercial sex and condomless sex with sex workers, for male rural-urban migrants. Using a multi-stage sample of 1,591 male rural-urban migrants from two major migrant-influx cities within China, we assessed migrants' general friend network ties and native place networks (townsmen in migrants' local networks) and tested their associations with SRBs. Multiple logistic regression analyses indicate that native-place network ties are associated with paying for sex (OR = 1.33, p < 0.001) and condomless sex with sex workers (OR = 1.33, p < 0.001), while general friendship network ties reduce such risks (OR = 0.74, p < 0.001; OR = 0.84, p < 0.01) even after controlling for demographic background, housing conditions, length of stay, health beliefs and behaviours, and spousal companionship. Our findings suggest that native-place networks among Chinese male rural-urban migrants are associated with SRBs because homogenous networks may serve as a platform for the emergence of a deviant subculture that promotes risk behaviours. A Virtual Abstract of this paper is available at: https://www.youtube.com/watch?v=3Wg20I6j8XQ. © 2015 Foundation for the Sociology of Health & Illness.

  8. Development of Pavement Maintenance Management System (PMMS of Urban Road Network Using HDM-4 Model

    Directory of Open Access Journals (Sweden)

    Tanuj Chopra

    2017-04-01

    Full Text Available The aim of the study is to develop Pavement Maintenance Management System (PMMS for four road sections of urban road network (Patiala, Punjab, India using Highway Development and Management (HDM-4 model. The HDM-4 provides a deterministic approach in data input and process data of existing road condition, traffic volume and pavement composition to predict road deterioration as per the urban road conditions in terms of International Roughness Index (IRI value. This study presents the use of HDM-4 model for the computation of optimum Maintenance and Rehabilitation (M&R strategy for each road section and comparative study of scheduled and condition responsive M&R strategies. The results of present study will be useful for gaining better support for decision-makers for adequate and timely fund allocations for preservation of the urban road network.

  9. Using mobile probes to inform and measure the effectiveness of macroscopic traffic control strategies on urban networks.

    Science.gov (United States)

    2015-06-01

    Urban traffic congestion is a problem that plagues many cities in the United States. Testing strategies to alleviate this : congestion is especially challenging due to the difficulty of modeling complex urban traffic networks. However, recent work ha...

  10. Urban transport, the environment and the network society

    DEFF Research Database (Denmark)

    Hansen, Carsten Jahn

    2005-01-01

    Based on the conclusions of a completed Ph.D. thesis and post doctoral research activities, this paper describes and analyses environmental objectives and strategies have materialised in three cases of local transport policy making and planning; in the urban areas of Lund (Sweden), Groningen (The...... succeeded over conventional and more hierarchical ways of public policymaking. As such, these cases offer illuminating examples of collaborative dialogue, expressed through networks in which argumentative approaches and increased reflexivity about the ´rules of the game´ have been central elements. Finally...

  11. Trans-European transport networks influence on the regional development and urban systems: Serbian experience

    OpenAIRE

    Maksin-Mićić Marija

    2004-01-01

    The trans-European transport network has different effects at macro-regional, mezzo-regional and micro-regional level, and on urban systems development, and its effectiveness rises at the lower regional levels. Possible approaches to the trans-European transport network impact and effect survey and policy options have been pointed out. The importance of increased accessibility and mobility for regional expansion and for more balanced and polycentric system of city networks has been underlined...

  12. The Impact of Drainage Network Structure on Flooding in a Small Urban Watershed in Metropolitan Baltimore, MD

    Science.gov (United States)

    Meierdiercks, K. L.; Smith, J. A.; Miller, A. J.

    2006-12-01

    The impact of urban development on watershed-scale hydrology is examined in a small urban watershed in the Metropolitan Baltimore area. Analyses focus on Dead Run, a 14.3 km2 tributary of the Gwynns Falls, which is the principal study watershed of the Baltimore Ecosystem Study. Field observations of rainfall and discharge have been collected for storms occurring in the 2003, 2004, and 2005 warm seasons including the flood of record for the USGS Dead Run at Franklintown gage (7 July 2004), in which 5 inches of rain fell in less than 4 hours. Dead Run has stream gages at 6 locations with drainage areas ranging from 1.2 to 14.3 km2. Hydrologic response to storm events varies greatly in each of the subwatersheds due to the diverse development types located there. These subwatersheds range in land use from medium-density residential, with and without stormwater management control, to commercial/light industrial with large impervious lots and an extensive network of stormwater management ponds. The unique response of each subwatershed is captured using field observations in conjunction with the EPA Stormwater Management Model (SWMM), which routes storm runoff over the land surface and through the drainage network of a watershed. Of particular importance to flood response is the structure of the drainage network (both surface channels and storm drain network) and its connectivity to preferential flow paths within the watershed. The Dead Run drainage network has been delineated using geospatial data derived from aerial photography and engineering planning drawings. Model analyses are used to examine the characteristics of flow paths that control flood response in urban watersheds. These analyses aim to identify patterns in urban flow pathways and use those patterns to predict response in other urban watersheds.

  13. A versatile sensor network for urban search and rescue operations

    Science.gov (United States)

    Känsälä, Klaus; Korkalainen, Marko; Mäyrä, Aki

    2011-11-01

    The presentation is based in the research work carried out in EU funded project SGL for USaR (Second Generation Locator for Urban Search and Rescue Operations). The aim of this project is to develop wireless standalone communication system with embedded sensor network which can be globally used in rescue operations after accidents or terrorist attacks. The system should be able to operate without external support for several days: it should have autonomy with power supply and communication. The devices must be lightweight so that rescue team can easily carry them and finally they must be easy to install and use. The range of the wireless communication must cover an area of several square kilometers. The embedded sensor system must be able to detect sings of life but also detect hazards threatening the rescue operators thus preventing more accidents. It should also support positioning and digital mapping as well as the management of the search and rescue operation. This sensor network for urban search and rescue operations has been tested on a field conditions and it has proven to be robust and reliable and provides an energy efficient way of communication and positioning on harsh conditions.

  14. Urban Thermodynamic Island in a Coastal City Analysed from an Optimized Surface Network

    Science.gov (United States)

    Pigeon, Grégoire; Lemonsu, Aude; Long, Nathalie; Barrié, Joël; Masson, Valéry; Durand, Pierre

    2006-08-01

    Within the framework of ESCOMPTE, a French experiment performed in June and July 2001 in the south-east of France to study the photo-oxidant pollution at the regional scale, the urban boundary layer (UBL) program focused on the study of the urban atmosphere over the coastal city of Marseille. A methodology developed to optimize a network of 20 stations measuring air temperature and moisture over the city is presented. It is based on the analysis of a numerical simulation, performed with the non-hydrostatic, mesoscale Meso-NH model, run with four nested-grids down to a horizontal resolution of 250 m over the city and including a specific parametrization for the urban surface energy balance. A three-day period was modelled and evaluated against data collected during the preparatory phase for the project in summer 2000. The simulated thermodynamic surface fields were analysed using an empirical orthogonal function (EOF) decomposition in order to determine the optimal network configuration designed to capture the dominant characteristics of the fields. It is the first attempt of application of this kind of methodology to the field of urban meteorology. The network, of 20 temperature and moisture sensors, was implemented during the UBL-ESCOMPTE experiment and continuously recorded data from 12 June to 14 July 2001. The measurements were analysed in order to assess the urban thermodynamic island spatio-temporal structure, also using EOF decomposition. During nighttime, the influence of urbanization on temperature is clear the field is characterized by concentric thermo-pleths around the old core of the city, which is the warmest area of the domain. The moisture field is more influenced by proximity to the sea and airflow patterns. During the day, the sea breeze often moves from west or south-west and consequently the spatial pattern for both parameters is characterized by a gradient perpendicular to the shoreline. Finally, in order to assess the methodology adopted, the

  15. Optimal redistribution of an urban air quality monitoring network using atmospheric dispersion model and genetic algorithm

    Science.gov (United States)

    Hao, Yufang; Xie, Shaodong

    2018-03-01

    Air quality monitoring networks play a significant role in identifying the spatiotemporal patterns of air pollution, and they need to be deployed efficiently, with a minimum number of sites. The revision and optimal adjustment of existing monitoring networks is crucial for cities that have undergone rapid urban expansion and experience temporal variations in pollution patterns. The approach based on the Weather Research and Forecasting-California PUFF (WRF-CALPUFF) model and genetic algorithm (GA) was developed to design an optimal monitoring network. The maximization of coverage with minimum overlap and the ability to detect violations of standards were developed as the design objectives for redistributed networks. The non-dominated sorting genetic algorithm was applied to optimize the network size and site locations simultaneously for Shijiazhuang city, one of the most polluted cities in China. The assessment on the current network identified the insufficient spatial coverage of SO2 and NO2 monitoring for the expanding city. The optimization results showed that significant improvements were achieved in multiple objectives by redistributing the original network. Efficient coverage of the resulting designs improved to 60.99% and 76.06% of the urban area for SO2 and NO2, respectively. The redistributing design for multi-pollutant including 8 sites was also proposed, with the spatial representation covered 52.30% of the urban area and the overlapped areas decreased by 85.87% compared with the original network. The abilities to detect violations of standards were not improved as much as the other two objectives due to the conflicting nature between the multiple objectives. Additionally, the results demonstrated that the algorithm was slightly sensitive to the parameter settings, with the number of generations presented the most significant effect. Overall, our study presents an effective and feasible procedure for air quality network optimization at a city scale.

  16. "Coming to town": the impact of urbanicity, cigarette advertising, and network norms on the smoking attitudes of black women in Cape Town, South Africa.

    Science.gov (United States)

    Williams, Chyvette T; Grier, Sonya A; Marks, Amy Seidel

    2008-07-01

    This study was conducted to examine the effect of urban living on smoking attitudes among black African women in South Africa. We examine how urbanicity affects attitudes toward smoking and how it moderates the relationship between both advertising exposure and network norms on black women's smoking attitudes. Respondents were 975 black women currently living in Cape Town townships, some of which were raised in rural villages or small towns. Respondents completed a cross-sectional survey, which included data on smoking attitudes, norms, and exposure to cigarette advertising. Multiple linear regression analysis was performed with smoking attitudes as the response variable, and urbanicity, cigarette advertising exposure, and network smoking norms as primary explanatory variables. Interactions were tested to determine whether urbanicity modified the effect of advertising exposure and network norms on smoking attitudes. Independent effects of urbanicity, exposure to cigarette advertising, and greater smoking prevalence within women's networks were associated with more favorable smoking attitudes. In addition, urbanicity moderated the relationship between network smoking norms and smoking attitudes, but not cigarette advertising exposure and smoking attitudes. Urbanicity, cigarette advertising, and networks play important roles in women's attitudes toward smoking, and potentially, smoking behavior. Overall, our results suggest that strong and creative anti-smoking efforts are needed to combat the potential for a smoking epidemic among an increasingly urbanized population of black women in South Africa and similar emerging markets. Additional research is warranted.

  17. Comparison study on qualitative and quantitative risk assessment methods for urban natural gas pipeline network.

    Science.gov (United States)

    Han, Z Y; Weng, W G

    2011-05-15

    In this paper, a qualitative and a quantitative risk assessment methods for urban natural gas pipeline network are proposed. The qualitative method is comprised of an index system, which includes a causation index, an inherent risk index, a consequence index and their corresponding weights. The quantitative method consists of a probability assessment, a consequences analysis and a risk evaluation. The outcome of the qualitative method is a qualitative risk value, and for quantitative method the outcomes are individual risk and social risk. In comparison with previous research, the qualitative method proposed in this paper is particularly suitable for urban natural gas pipeline network, and the quantitative method takes different consequences of accidents into consideration, such as toxic gas diffusion, jet flame, fire ball combustion and UVCE. Two sample urban natural gas pipeline networks are used to demonstrate these two methods. It is indicated that both of the two methods can be applied to practical application, and the choice of the methods depends on the actual basic data of the gas pipelines and the precision requirements of risk assessment. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  18. Networked Mobilities and Performative Urban Environments

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    , an increasing number of such mobile practices are mediated by technologies of tangible and less tangible sorts. Thus by focusing on the complex relationship between material and virtual technologies within the sphere of mobility it is shown that we need to move beyond dichotomies of; global or local, nomad...... or sedentary, digital or material. The paper investigates the meaning of mobility and the potential in mediation and technologies to enhance the experiences and interaction in relation to urban transit spaces. In understanding the importance of mediation, global-local interactions, networks....... By studying embedded technologies and ‘ambient environments' we increase our knowledge about the over layering of the material environment with digital technologies. The presences of GPS, mediated surfaces, mobile agents (robots), RFID and other technologies that all relate to contemporary mobility practices...

  19. Urban energy consumption: Different insights from energy flow analysis, input–output analysis and ecological network analysis

    International Nuclear Information System (INIS)

    Chen, Shaoqing; Chen, Bin

    2015-01-01

    Highlights: • Urban energy consumption was assessed from three different perspectives. • A new concept called controlled energy was developed from network analysis. • Embodied energy and controlled energy consumption of Beijing were compared. • The integration of all three perspectives will elucidate sustainable energy use. - Abstract: Energy consumption has always been a central issue for sustainable urban assessment and planning. Different forms of energy analysis can provide various insights for energy policy making. This paper brought together three approaches for energy consumption accounting, i.e., energy flow analysis (EFA), input–output analysis (IOA) and ecological network analysis (ENA), and compared their different perspectives and the policy implications for urban energy use. Beijing was used to exemplify the different energy analysis processes, and the 42 economic sectors of the city were aggregated into seven components. It was determined that EFA quantifies both the primary and final energy consumption of the urban components by tracking the different types of fuel used by the urban economy. IOA accounts for the embodied energy consumption (direct and indirect) used to produce goods and services in the city, whereas the control analysis of ENA quantifies the specific embodied energy that is regulated by the activities within the city’s boundary. The network control analysis can also be applied to determining which economic sectors drive the energy consumption and to what extent these sectors are dependent on each other for energy. So-called “controlled energy” is a new concept that adds to the analysis of urban energy consumption, indicating the adjustable energy consumed by sectors. The integration of insights from all three accounting perspectives further our understanding of sustainable energy use in cities

  20. Complex Network Theory Applied to the Growth of Kuala Lumpur's Public Urban Rail Transit Network.

    Directory of Open Access Journals (Sweden)

    Rui Ding

    Full Text Available Recently, the number of studies involving complex network applications in transportation has increased steadily as scholars from various fields analyze traffic networks. Nonetheless, research on rail network growth is relatively rare. This research examines the evolution of the Public Urban Rail Transit Networks of Kuala Lumpur (PURTNoKL based on complex network theory and covers both the topological structure of the rail system and future trends in network growth. In addition, network performance when facing different attack strategies is also assessed. Three topological network characteristics are considered: connections, clustering and centrality. In PURTNoKL, we found that the total number of nodes and edges exhibit a linear relationship and that the average degree stays within the interval [2.0488, 2.6774] with heavy-tailed distributions. The evolutionary process shows that the cumulative probability distribution (CPD of degree and the average shortest path length show good fit with exponential distribution and normal distribution, respectively. Moreover, PURTNoKL exhibits clear cluster characteristics; most of the nodes have a 2-core value, and the CPDs of the centrality's closeness and betweenness follow a normal distribution function and an exponential distribution, respectively. Finally, we discuss four different types of network growth styles and the line extension process, which reveal that the rail network's growth is likely based on the nodes with the biggest lengths of the shortest path and that network protection should emphasize those nodes with the largest degrees and the highest betweenness values. This research may enhance the networkability of the rail system and better shape the future growth of public rail networks.

  1. A network centrality measure framework for analyzing urban traffic flow: A case study of Wuhan, China

    Science.gov (United States)

    Zhao, Shuangming; Zhao, Pengxiang; Cui, Yunfan

    2017-07-01

    In this paper, we propose an improved network centrality measure framework that takes into account both the topological characteristics and the geometric properties of a road network in order to analyze urban traffic flow in relation to different modes: intersection, road, and community, which correspond to point mode, line mode, and area mode respectively. Degree, betweenness, and PageRank centralities are selected as the analysis measures, and GPS-enabled taxi trajectory data is used to evaluate urban traffic flow. The results show that the mean value of the correlation coefficients between the modified degree, the betweenness, and the PageRank centralities and the traffic flow in all periods are higher than the mean value of the correlation coefficients between the conventional degree, the betweenness, the PageRank centralities and the traffic flow at different modes; this indicates that the modified measurements, for analyzing traffic flow, are superior to conventional centrality measurements. This study helps to shed light into the understanding of urban traffic flow in relation to different modes from the perspective of complex networks.

  2. Lessons learned on solar powered wireless sensor network deployments in urban, desert environments

    KAUST Repository

    Dehwah, Ahmad H.; Mousa, Mustafa; Claudel, Christian G.

    2015-01-01

    The successful deployment of a large scale solar powered wireless sensor network in an urban, desert environment is a very complex task. Specific cities of such environments cause a variety of operational problems, ranging from hardware faults

  3. Analysis of changes in farm pond network connectivity in the peri-urban landscape of the Taoyuan area, Taiwan.

    Science.gov (United States)

    Huang, Shu-Li; Lee, Ying-Chieh; Budd, William W; Yang, Min-Chia

    2012-04-01

    The farm pond system for irrigation is the most prominent feature in the Taoyuan area, Taiwan, giving the region a unique landscape and hydrological character. Although this area had more than 3,290 ponds in the 1970s, fewer than 1,800 now remain. This study analyzes changes in irrigation farm ponds and the canal network landscape in the Taoyuan area. The spatial and temporal changes to ponds and the canal network on the Taoyuan plain were examined graphically for each spatial unit (2,765 m × 2,525 m) using aerial photographs for 1979 and 2005. Landscape metrics were calculated to analyze landscape change associated with increased urbanization. Landscape indices of connectivity and circuitry were utilized to describe changes in the configuration of ponds and canal networks. The total length of canals and total number of ponds in the study area decreased significantly during 1979-2005. The average values of connectivity indices (γ- and α-index) also decreased during 1979-2005, reflecting degradation of canal networks due to urban sprawl. A multivariate technique was applied to portion the study area into three zones according to changes to land cover, ponds, and canal networks. The effects of urban sprawl on the spatial pattern of ponds and canal networks are discussed.

  4. On the feasibility of measuring urban air pollution by wireless distributed sensor networks.

    Science.gov (United States)

    Moltchanov, Sharon; Levy, Ilan; Etzion, Yael; Lerner, Uri; Broday, David M; Fishbain, Barak

    2015-01-01

    Accurate evaluation of air pollution on human-wellbeing requires high-resolution measurements. Standard air quality monitoring stations provide accurate pollution levels but due to their sparse distribution they cannot capture the highly resolved spatial variations within cities. Similarly, dedicated field campaigns can use tens of measurement devices and obtain highly dense spatial coverage but normally deployment has been limited to short periods of no more than few weeks. Nowadays, advances in communication and sensory technologies enable the deployment of dense grids of wireless distributed air monitoring nodes, yet their sensor ability to capture the spatiotemporal pollutant variability at the sub-neighborhood scale has never been thoroughly tested. This study reports ambient measurements of gaseous air pollutants by a network of six wireless multi-sensor miniature nodes that have been deployed in three urban sites, about 150 m apart. We demonstrate the network's capability to capture spatiotemporal concentration variations at an exceptional fine resolution but highlight the need for a frequent in-situ calibration to maintain the consistency of some sensors. Accordingly, a procedure for a field calibration is proposed and shown to improve the system's performance. Overall, our results support the compatibility of wireless distributed sensor networks for measuring urban air pollution at a sub-neighborhood spatial resolution, which suits the requirement for highly spatiotemporal resolved measurements at the breathing-height when assessing exposure to urban air pollution. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Flood forecasting within urban drainage systems using NARX neural network.

    Science.gov (United States)

    Abou Rjeily, Yves; Abbas, Oras; Sadek, Marwan; Shahrour, Isam; Hage Chehade, Fadi

    2017-11-01

    Urbanization activity and climate change increase the runoff volumes, and consequently the surcharge of the urban drainage systems (UDS). In addition, age and structural failures of these utilities limit their capacities, and thus generate hydraulic operation shortages, leading to flooding events. The large increase in floods within urban areas requires rapid actions from the UDS operators. The proactivity in taking the appropriate actions is a key element in applying efficient management and flood mitigation. Therefore, this work focuses on developing a flooding forecast system (FFS), able to alert in advance the UDS managers for possible flooding. For a forecasted storm event, a quick estimation of the water depth variation within critical manholes allows a reliable evaluation of the flood risk. The Nonlinear Auto Regressive with eXogenous inputs (NARX) neural network was chosen to develop the FFS as due to its calculation nature it is capable of relating water depth variation in manholes to rainfall intensities. The campus of the University of Lille is used as an experimental site to test and evaluate the FFS proposed in this paper.

  6. Building social networks for maternal and newborn health in poor urban settlements: a cross-sectional study in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Alayne M Adams

    Full Text Available The beneficial influence of social networks on health and wellbeing is well-established. In poor urban settlements in Bangladesh, BRAC's Manoshi programme trains community health workers (CHWs to support women through pregnancy, delivery and postpartum periods. This paper test the hypothesis that the introduction of CHWs as weak ties into the social networks of Manoshi members mediates improvements in maternal and neonatal health (MNH best practices by providing support, facilitating ideational change, connecting mother to resources, and strengthening or countering the influence of strong ties.1000 women who had given birth in the last three months were identified and interviewed as part of ongoing monitoring of 5 poor urban settlements in Dhaka, Bangladesh. A social networks questionnaire was administered which elicited women's perceived networks around pregnancy, delivery and post-partum periods. Mediation analysis was performed to test the hypothesis that penetration of Manoshi CHWs into women's perceived networks has a beneficial effect on MNH best practises.The presence and influence of Manoshi CHWs in women's networks significantly mediated the effect of Manoshi membership on MNH best practices. Respondents who were Manoshi members and who listed Manoshi CHWs as part of their support networks were significantly more likely to deliver with a trained birth attendant (OR 3.61; 95%CI 2.36-5.51, to use postnatal care (OR 3.09; 95%CI 1.83-5.22, and to give colostrum to their newborn (OR 7.51; 95%CI 3.51-16.05.Manoshi has succeeded in penetrating the perceived pregnancy, delivery and post-partum networks of poor urban women through the introduction of trained CHWs. Study findings demonstrate the benefits of moving beyond urban health care delivery models that concentrate on the provision of clinical services by medical providers, to an approach that nurtures the power of social networks as a means to support the poorest and most marginalized in

  7. Building social networks for maternal and newborn health in poor urban settlements: a cross-sectional study in Bangladesh.

    Science.gov (United States)

    Adams, Alayne M; Nababan, Herfina Y; Hanifi, S M Manzoor Ahmed

    2015-01-01

    The beneficial influence of social networks on health and wellbeing is well-established. In poor urban settlements in Bangladesh, BRAC's Manoshi programme trains community health workers (CHWs) to support women through pregnancy, delivery and postpartum periods. This paper test the hypothesis that the introduction of CHWs as weak ties into the social networks of Manoshi members mediates improvements in maternal and neonatal health (MNH) best practices by providing support, facilitating ideational change, connecting mother to resources, and strengthening or countering the influence of strong ties. 1000 women who had given birth in the last three months were identified and interviewed as part of ongoing monitoring of 5 poor urban settlements in Dhaka, Bangladesh. A social networks questionnaire was administered which elicited women's perceived networks around pregnancy, delivery and post-partum periods. Mediation analysis was performed to test the hypothesis that penetration of Manoshi CHWs into women's perceived networks has a beneficial effect on MNH best practises. The presence and influence of Manoshi CHWs in women's networks significantly mediated the effect of Manoshi membership on MNH best practices. Respondents who were Manoshi members and who listed Manoshi CHWs as part of their support networks were significantly more likely to deliver with a trained birth attendant (OR 3.61; 95%CI 2.36-5.51), to use postnatal care (OR 3.09; 95%CI 1.83-5.22), and to give colostrum to their newborn (OR 7.51; 95%CI 3.51-16.05). Manoshi has succeeded in penetrating the perceived pregnancy, delivery and post-partum networks of poor urban women through the introduction of trained CHWs. Study findings demonstrate the benefits of moving beyond urban health care delivery models that concentrate on the provision of clinical services by medical providers, to an approach that nurtures the power of social networks as a means to support the poorest and most marginalized in changing

  8. Trans-European transport networks influence on the regional development and urban systems: Serbian experience

    Directory of Open Access Journals (Sweden)

    Maksin-Mićić Marija

    2004-01-01

    Full Text Available The trans-European transport network has different effects at macro regional mezzo-regional and micro-regional level, and its effectiveness rises with the lower regional levels. Possible approaches to the trans-European transport network impact and effect survey and policy options have been pointed out. The importance of increased accessibility and mobility for regional expansion and for a more balanced and polycentric system of city networks has been underlined. Changes in the spatial organization utilization and structure of cities, as well as in social benefits and losses subsequent to impacts of trans-European transport corridor "X" section Belgrade-Niš have been analyzed. The new trans-European or major transport infrastructure does not per se create regional and urban system network development, although it can affect the conditions for the processes that create growth and development. The effects can be increased by co-ordination of measures of regional, spatial and urban policy, land use transport, environmental and other policies. The necessary measure is the introduction of spatial impact assessment as sartorial policy instrument for the large transport infrastructure plans and projects.

  9. Toward an Understanding of Citywide Urban Environmental Governance: An Examination of Stewardship Networks in Baltimore and Seattle.

    Science.gov (United States)

    Romolini, Michele; Morgan Grove, J; Ventriss, Curtis L; Koliba, Christopher J; Krymkowski, Daniel H

    2016-08-01

    Efforts to create more sustainable cities are evident in the proliferation of sustainability policies in cities worldwide. It has become widely proposed that the success of these urban sustainability initiatives will require city agencies to partner with, and even cede authority to, organizations from other sectors and levels of government. Yet the resulting collaborative networks are often poorly understood, and the study of large whole networks has been a challenge for researchers. We believe that a better understanding of citywide environmental governance networks can inform evaluations of their effectiveness, thus contributing to improved environmental management. Through two citywide surveys in Baltimore and Seattle, we collected data on the attributes of environmental stewardship organizations and their network relationships. We applied missing data treatment approaches and conducted social network and comparative analyses to examine (a) the organizational composition of the network, and (b) how information and knowledge are shared throughout the network. Findings revealed similarities in the number of actors and their distribution across sectors, but considerable variation in the types and locations of environmental stewardship activities, and in the number and distribution of network ties in the networks of each city. We discuss the results and potential implications of network research for urban sustainability governance.

  10. A wireless sensor network for urban traffic characterization and trend monitoring.

    Science.gov (United States)

    Fernández-Lozano, J J; Martín-Guzmán, Miguel; Martín-Ávila, Juan; García-Cerezo, A

    2015-10-15

    Sustainable mobility requires a better management of the available infrastructure resources. To achieve this goal, it is necessary to obtain accurate data about road usage, in particular in urban areas. Although a variety of sensor alternates for urban traffic exist, they usually require extensive investments in the form of construction works for installation, processing means, etc. Wireless Sensor Networks (WSN) are an alternative to acquire urban traffic data, allowing for flexible, easy deployment. Together with the use of the appropriate sensors, like Bluetooth identification, and associate processing, WSN can provide the means to obtain in real time data like the origin-destination matrix, a key tool for trend monitoring which previously required weeks or months to be completed. This paper presents a system based on WSN designed to characterize urban traffic, particularly traffic trend monitoring through the calculation of the origin-destination matrix in real time by using Bluetooth identification. Additional sensors are also available integrated in different types of nodes. Experiments in real conditions have been performed, both for separate sensors (Bluetooth, ultrasound and laser), and for the whole system, showing the feasibility of this approach.

  11. Towards a network of Urban Forest Eddy Covariance stations: a unique case study in Naples

    Science.gov (United States)

    Guidolotti, Gabriele; Pallozzi, Emanuele; Esposito, Raffaela; Mattioni, Michele; Calfapietra, Carlo

    2015-04-01

    Urban forests are by definition integrated in highly human-made areas, and interact with different components of our cities. Thanks to those interactions, urban forests provide to people and to the urban environment a number of ecosystem services, including the absorption of CO2 and air pollutants thus influencing the local air quality. Moreover, in urban areas a relevant role is played by the photochemical pollution which is strongly influenced by the interactions between volatile organic compounds (VOC) and nitrogen oxides (NOx). In several cities, a high percentage of VOC is of biogenic origin mainly emitted from the urban trees. Despite their importance, experimental sites monitoring fluxes of trace gases fluxes in urban forest ecosystems are still scarce. Here we show the preliminary results of an innovative experimental site located in the Royal Park of Capodimonte within the city of Naples (40°51'N-14°15'E, 130 m above sea level). The site is mainly characterised by Quercus ilex with some patches of Pinus pinea and equipped with an eddy-covariance tower measuring the exchange of CO2, H2O, N2O, CH4, O3, PM, VOCs and NOx using state-of-the art instrumentations; it is running since the end of 2014 and it is part of the large infrastructural I-AMICA project. We suggest that the experience gained with research networks such as Fluxnet and ICOS should be duplicated for urban forests. This is crucial for carbon as there is now the ambition to include urban forests in the carbon stocks accounting system. This is even more important to understand the difficult interactions between anthropogenic and biogenic sources that often have negative implications for urban air quality. Urban environment can thus become an extraordinary case study and a network of such kind of stations might represent an important strategy both from the scientific and the applicative point of view.

  12. Decentralized State-Observer-Based Traffic Density Estimation of Large-Scale Urban Freeway Network by Dynamic Model

    Directory of Open Access Journals (Sweden)

    Yuqi Guo

    2017-08-01

    Full Text Available In order to estimate traffic densities in a large-scale urban freeway network in an accurate and timely fashion when traffic sensors do not cover the freeway network completely and thus only local measurement data can be utilized, this paper proposes a decentralized state observer approach based on a macroscopic traffic flow model. Firstly, by using the well-known cell transmission model (CTM, the urban freeway network is modeled in the way of distributed systems. Secondly, based on the model, a decentralized observer is designed. With the help of the Lyapunov function and S-procedure theory, the observer gains are computed by using linear matrix inequality (LMI technique. So, the traffic densities of the whole road network can be estimated by the designed observer. Finally, this method is applied to the outer ring of the Beijing’s second ring road and experimental results demonstrate the effectiveness and applicability of the proposed approach.

  13. The Relationship of Policymaking and Networking Characteristics among Leaders of Large Urban Health Departments.

    Science.gov (United States)

    Leider, Jonathon P; Castrucci, Brian C; Harris, Jenine K; Hearne, Shelley

    2015-08-06

    The relationship between policy networks and policy development among local health departments (LHDs) is a growing area of interest to public health practitioners and researchers alike. In this study, we examine policy activity and ties between public health leadership across large urban health departments. This study uses data from a national profile of local health departments as well as responses from a survey sent to three staff members (local health official, chief of policy, chief science officer) in each of 16 urban health departments in the United States. Network questions related to frequency of contact with health department personnel in other cities. Using exponential random graph models, network density and centrality were examined, as were patterns of communication among those working on several policy areas using exponential random graph models. All 16 LHDs were active in communicating about chronic disease as well as about use of alcohol, tobacco, and other drugs (ATOD). Connectedness was highest among local health officials (density = .55), and slightly lower for chief science officers (d = .33) and chiefs of policy (d = .29). After accounting for organizational characteristics, policy homophily (i.e., when two network members match on a single characteristic) and tenure were the most significant predictors of formation of network ties. Networking across health departments has the potential for accelerating the adoption of public health policies. This study suggests similar policy interests and formation of connections among senior leadership can potentially drive greater connectedness among other staff.

  14. Pollution source localization in an urban water supply network based on dynamic water demand.

    Science.gov (United States)

    Yan, Xuesong; Zhu, Zhixin; Li, Tian

    2017-10-27

    Urban water supply networks are susceptible to intentional, accidental chemical, and biological pollution, which pose a threat to the health of consumers. In recent years, drinking-water pollution incidents have occurred frequently, seriously endangering social stability and security. The real-time monitoring for water quality can be effectively implemented by placing sensors in the water supply network. However, locating the source of pollution through the data detection obtained by water quality sensors is a challenging problem. The difficulty lies in the limited number of sensors, large number of water supply network nodes, and dynamic user demand for water, which leads the pollution source localization problem to an uncertainty, large-scale, and dynamic optimization problem. In this paper, we mainly study the dynamics of the pollution source localization problem. Previous studies of pollution source localization assume that hydraulic inputs (e.g., water demand of consumers) are known. However, because of the inherent variability of urban water demand, the problem is essentially a fluctuating dynamic problem of consumer's water demand. In this paper, the water demand is considered to be stochastic in nature and can be described using Gaussian model or autoregressive model. On this basis, an optimization algorithm is proposed based on these two dynamic water demand change models to locate the pollution source. The objective of the proposed algorithm is to find the locations and concentrations of pollution sources that meet the minimum between the analogue and detection values of the sensor. Simulation experiments were conducted using two different sizes of urban water supply network data, and the experimental results were compared with those of the standard genetic algorithm.

  15. Improving the urban green system and green network through the rehabilitation of railway rust areas

    Directory of Open Access Journals (Sweden)

    Hutter Dóra

    2014-11-01

    Full Text Available The Industrial Revolution had a negative impact on both the city and the environment. By the second half of the 19th century, the urban erosion of industrial cities cried for direct intervention and curing. The methods developed either along an urban or an anti-urban philosophy: they resulted in the new models of green belt systems aimed at solving all the main urban problems with restructuring the urban fabric, controlling the urban spread into the rural landscape, the lack of green areas and open spaces for recreation and social life, and the lack of green spaces for ventilation. Nowadays, the major cities and capitals around the globe are competing for titles such as healthier, more liveable or even greener city. Given the unfortunate attributes of the urban structure in the historical cities, the development of new transportation sites or green areas is an extremely difficult issue. On the other hand, in the big cities, the brownfield sites are considered as reserve areas for sustainable urban development. Reusing the brownfields and rust areas is already a land saving urban development approach and in case of a complex and ecological urban rehabilitation it can underlie the development of an efficient urban green system and green network.

  16. Portraying Temporal Dynamics of Urban Spatial Divisions with Mobile Phone Positioning Data: A Complex Network Approach

    Directory of Open Access Journals (Sweden)

    Meng Zhou

    2016-12-01

    Full Text Available Spatial structure is a fundamental characteristic of cities that influences the urban functioning to a large extent. While administrative partitioning is generally done in the form of static spatial division, understanding a more temporally dynamic structure of the urban space would benefit urban planning and management immensely. This study makes use of a large-scale mobile phone positioning dataset to characterize the diurnal dynamics of the interaction-based urban spatial structure. To extract the temporally vibrant structure, spatial interaction networks at different times are constructed based on the movement connections of individuals between geographical units. Complex network community detection technique is applied to identify the spatial divisions as well as to quantify their temporal dynamics. Empirical analysis is conducted using data containing all user positions on a typical weekday in Shenzhen, China. Results are compared with official zoning and planned structure and indicate a certain degree of expansion in urban central areas and fragmentation in industrial suburban areas. A high level of variability in spatial divisions at different times of day is detected with some distinct temporal features. Peak and pre-/post-peak hours witness the most prominent fluctuation in spatial division indicating significant change in the characteristics of movements and activities during these periods of time. Findings of this study demonstrate great potential of large-scale mobility data in supporting intelligent spatial decision making and providing valuable knowledge to the urban planning sectors.

  17. Urban Freight Management with Stochastic Time-Dependent Travel Times and Application to Large-Scale Transportation Networks

    Directory of Open Access Journals (Sweden)

    Shichao Sun

    2015-01-01

    Full Text Available This paper addressed the vehicle routing problem (VRP in large-scale urban transportation networks with stochastic time-dependent (STD travel times. The subproblem which is how to find the optimal path connecting any pair of customer nodes in a STD network was solved through a robust approach without requiring the probability distributions of link travel times. Based on that, the proposed STD-VRP model can be converted into solving a normal time-dependent VRP (TD-VRP, and algorithms for such TD-VRPs can also be introduced to obtain the solution. Numerical experiments were conducted to address STD-VRPTW of practical sizes on a real world urban network, demonstrated here on the road network of Shenzhen, China. The stochastic time-dependent link travel times of the network were calibrated by historical floating car data. A route construction algorithm was applied to solve the STD problem in 4 delivery scenarios efficiently. The computational results showed that the proposed STD-VRPTW model can improve the level of customer service by satisfying the time-window constraint under any circumstances. The improvement can be very significant especially for large-scale network delivery tasks with no more increase in cost and environmental impacts.

  18. Urban Heat Island Growth Modeling Using Artificial Neural Networks and Support Vector Regression: A case study of Tehran, Iran

    Science.gov (United States)

    Sherafati, Sh. A.; Saradjian, M. R.; Niazmardi, S.

    2013-09-01

    Numerous investigations on Urban Heat Island (UHI) show that land cover change is the main factor of increasing Land Surface Temperature (LST) in urban areas. Therefore, to achieve a model which is able to simulate UHI growth, urban expansion should be concerned first. Considerable researches on urban expansion modeling have been done based on cellular automata. Accordingly the objective of this paper is to implement CA method for trend detection of Tehran UHI spatiotemporal growth based on urban sprawl parameters (such as Distance to nearest road, Digital Elevation Model (DEM), Slope and Aspect ratios). It should be mentioned that UHI growth modeling may have more complexities in comparison with urban expansion, since the amount of each pixel's temperature should be investigated instead of its state (urban and non-urban areas). The most challenging part of CA model is the definition of Transfer Rules. Here, two methods have used to find appropriate transfer Rules which are Artificial Neural Networks (ANN) and Support Vector Regression (SVR). The reason of choosing these approaches is that artificial neural networks and support vector regression have significant abilities to handle the complications of such a spatial analysis in comparison with other methods like Genetic or Swarm intelligence. In this paper, UHI change trend has discussed between 1984 and 2007. For this purpose, urban sprawl parameters in 1984 have calculated and added to the retrieved LST of this year. In order to achieve LST, Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+) night-time images have exploited. The reason of implementing night-time images is that UHI phenomenon is more obvious during night hours. After that multilayer feed-forward neural networks and support vector regression have used separately to find the relationship between this data and the retrieved LST in 2007. Since the transfer rules might not be the same in different regions, the satellite image of the city has

  19. Nitrous oxide emissions in the Shanghai river network: implications for the effects of urban sewage and IPCC methodology.

    Science.gov (United States)

    Yu, Zhongjie; Deng, Huanguang; Wang, Dongqi; Ye, Mingwu; Tan, Yongjie; Li, Yangjie; Chen, Zhenlou; Xu, Shiyuan

    2013-10-01

    Global nitrogen (N) enrichment has resulted in increased nitrous oxide (N(2)O) emission that greatly contributes to climate change and stratospheric ozone destruction, but little is known about the N(2)O emissions from urban river networks receiving anthropogenic N inputs. We examined N(2)O saturation and emission in the Shanghai city river network, covering 6300 km(2), over 27 months. The overall mean saturation and emission from 87 locations was 770% and 1.91 mg N(2)O-N m(-2) d(-1), respectively. Nitrous oxide (N(2)O) saturation did not exhibit a clear seasonality, but the temporal pattern was co-regulated by both water temperature and N loadings. Rivers draining through urban and suburban areas receiving more sewage N inputs had higher N(2)O saturation and emission than those in rural areas. Regression analysis indicated that water ammonium (NH(4)(+)) and dissolved oxygen (DO) level had great control on N(2)O production and were better predictors of N(2)O emission in urban watershed. About 0.29 Gg N(2)O-N yr(-1) N(2)O was emitted from the Shanghai river network annually, which was about 131% of IPCC's prediction using default emission values. Given the rapid progress of global urbanization, more study efforts, particularly on nitrification and its N(2)O yielding, are needed to better quantify the role of urban rivers in global riverine N(2)O emission. © 2013 John Wiley & Sons Ltd.

  20. The Relationship of Policymaking and Networking Characteristics among Leaders of Large Urban Health Departments

    Directory of Open Access Journals (Sweden)

    Jonathon P. Leider

    2015-08-01

    Full Text Available Background: The relationship between policy networks and policy development among local health departments (LHDs is a growing area of interest to public health practitioners and researchers alike. In this study, we examine policy activity and ties between public health leadership across large urban health departments. Methods: This study uses data from a national profile of local health departments as well as responses from a survey sent to three staff members (local health official, chief of policy, chief science officer in each of 16 urban health departments in the United States. Network questions related to frequency of contact with health department personnel in other cities. Using exponential random graph models, network density and centrality were examined, as were patterns of communication among those working on several policy areas using exponential random graph models. Results: All 16 LHDs were active in communicating about chronic disease as well as about use of alcohol, tobacco, and other drugs (ATOD. Connectedness was highest among local health officials (density = .55, and slightly lower for chief science officers (d = .33 and chiefs of policy (d = .29. After accounting for organizational characteristics, policy homophily (i.e., when two network members match on a single characteristic and tenure were the most significant predictors of formation of network ties. Conclusion: Networking across health departments has the potential for accelerating the adoption of public health policies. This study suggests similar policy interests and formation of connections among senior leadership can potentially drive greater connectedness among other staff.

  1. Promoting and developing a trail network across suburban, rural, and urban communities.

    Science.gov (United States)

    Schasberger, Michele G; Hussa, Carol S; Polgar, Michael F; McMonagle, Julie A; Burke, Sharon J; Gegaris, Andrew J

    2009-12-01

    The Wyoming Valley Wellness Trails Partnership received an Active Living by Design grant late in 2003 for a project centered on a growing trail network linking urban, suburban, and rural communities in northeast Pennsylvania, a former coal region, in order to increase physical activity among residents. The partnership conducted research, collected information, created promotional documents, worked with partners on events and programs, and participated in trail planning. Local trail organizations continued planning and construction toward developing a trail network. Other partners spearheaded policy change in schools and worksites and worked toward downtown revitalization. The partnership assisted these efforts by providing a forum in which organizations could meet. The partnership became a central resource for information about local parks, trails, and outdoor recreational activities. The partnership increased awareness and use of recreational facilities. Trail partners constructed 22 miles of walking and biking trails. The partnership took advantage of an allied effort that created organizational capacity for wellness in schools and worksites. Messages promoting social and entertainment benefits of physical activity were more successful than those promoting health benefits. The existence of multiple small, independent trail organizations can help advance trail development through concurrent development efforts. Urban, suburban, and rural residents' conceptions of walkability may differ. Trails provide options for recreational and transportation-related physical activity across urban, suburban, and rural landscapes that are supported by all constituents. Trail builders can be strong allies in bringing active living to suburban and rural places.

  2. Urban Traffic Signal System Control Structural Optimization Based on Network Analysis

    Directory of Open Access Journals (Sweden)

    Li Wang

    2013-01-01

    Full Text Available Advanced urban traffic signal control systems such as SCOOT and SCATS normally coordinate traffic network using multilevel hierarchical control mechanism. In this mechanism, several key intersections will be selected from traffic signal network and the network will be divided into different control subareas. Traditionally, key intersection selection and control subareas division are executed according to dynamic traffic counts and link length between intersections, which largely rely on traffic engineers’ experience. However, it omits important inherent characteristics of traffic network topology. In this paper, we will apply network analysis approach into these two aspects for traffic system control structure optimization. Firstly, the modified C-means clustering algorithm will be proposed to assess the importance of intersections in traffic network and furthermore determine the key intersections based on three indexes instead of merely on traffic counts in traditional methods. Secondly, the improved network community discovery method will be used to give more reasonable evidence in traffic control subarea division. Finally, to test the effectiveness of network analysis approach, a hardware-in-loop simulation environment composed of regional traffic control system, microsimulation software and signal controller hardware, will be built. Both traditional method and proposed approach will be implemented on simulation test bed to evaluate traffic operation performance indexes, for example, travel time, stop times, delay and average vehicle speed. Simulation results show that the proposed network analysis approach can improve the traffic control system operation performance effectively.

  3. Simulation and evaluation of urban rail transit network based on multi-agent approach

    Directory of Open Access Journals (Sweden)

    Xiangming Yao

    2013-03-01

    Full Text Available Purpose: Urban rail transit is a complex and dynamic system, which is difficult to be described in a global mathematical model for its scale and interaction. In order to analyze the spatial and temporal characteristics of passenger flow distribution and evaluate the effectiveness of transportation strategies, a new and comprehensive method depicted such dynamic system should be given. This study therefore aims at using simulation approach to solve this problem for subway network. Design/methodology/approach: In this thesis a simulation model based on multi-agent approach has been proposed, which is a well suited method to design complex systems. The model includes the specificities of passengers’ travelling behaviors and takes into account of interactions between travelers and trains. Findings: Research limitations/implications: We developed an urban rail transit simulation tool for verification of the validity and accuracy of this model, using real passenger flow data of Beijing subway network to take a case study, results show that our simulation tool can be used to analyze the characteristic of passenger flow distribution and evaluate operation strategies well. Practical implications: The main implications of this work are to provide decision support for traffic management, making train operation plan and dispatching measures in emergency. Originality/value: A new and comprehensive method to analyze and evaluate subway network is presented, accuracy and computational efficiency of the model has been confirmed and meet with the actual needs for large-scale network.

  4. Spatial Linkage and Urban Expansion: AN Urban Agglomeration View

    Science.gov (United States)

    Jiao, L. M.; Tang, X.; Liu, X. P.

    2017-09-01

    Urban expansion displays different characteristics in each period. From the perspective of the urban agglomeration, studying the spatial and temporal characteristics of urban expansion plays an important role in understanding the complex relationship between urban expansion and network structure of urban agglomeration. We analyze urban expansion in the Yangtze River Delta Urban Agglomeration (YRD) through accessibility to and spatial interaction intensity from core cities as well as accessibility of road network. Results show that: (1) Correlation between urban expansion intensity and spatial indicators such as location and space syntax variables is remarkable and positive, while it decreases after rapid expansion. (2) Urban expansion velocity displays a positive correlation with spatial indicators mentioned above in the first (1980-1990) and second (1990-2000) period. However, it exhibits a negative relationship in the third period (2000-2010), i.e., cities located in the periphery of urban agglomeration developing more quickly. Consequently, the hypothesis of convergence of urban expansion in rapid expansion stage is put forward. (3) Results of Zipf's law and Gibrat's law show urban expansion in YRD displays a convergent trend in rapid expansion stage, small and medium-sized cities growing faster. This study shows that spatial linkage plays an important but evolving role in urban expansion within the urban agglomeration. In addition, it serves as a reference to the planning of Yangtze River Delta Urban Agglomeration and regulation of urban expansion of other urban agglomerations.

  5. Filling the gap between disaster preparedness and response networks of urban emergency management: Following the 2013 Seoul Floods.

    Science.gov (United States)

    Song, Minsun; Jung, Kyujin

    2015-01-01

    To examine the gap between disaster preparedness and response networks following the 2013 Seoul Floods in which the rapid transmission of disaster information and resources was impeded by severe changes of interorganizational collaboration networks. This research uses the 2013 Seoul Emergency Management Survey data that were collected before and after the floods, and total 94 organizations involving in coping with the floods were analyzed in bootstrap independent-sample t-test and social network analysis through UCINET 6 and STATA 12. The findings show that despite the primary network form that is more hierarchical, horizontal collaboration has been relatively invigorated in actual response. Also, interorganizational collaboration networks for response operations seem to be more flexible grounded on improvisation to coping with unexpected victims and damages. Local organizations under urban emergency management are recommended to tightly build a strong commitment for joint response operations through full-size exercises at the metropolitan level before a catastrophic event. Also, interorganizational emergency management networks need to be restructured by reflecting the actual response networks to reduce collaboration risk during a disaster. This research presents a critical insight into inverse thinking of the view designing urban emergency management networks and provides original evidences for filling the gap between previously coordinated networks for disaster preparedness and practical response operations after a disaster.

  6. Cooperating Mobile GIS and Wireless Sensor Networks for Managing Transportation Infrastructures in Urban areas

    Directory of Open Access Journals (Sweden)

    R. Shad

    2013-10-01

    Full Text Available Time management is a major subject which, in order to optimize trip conditions, emphasizes on interpreting processes and classifying individual's information. In this paper, with the aim of providing an optimal system for urban commuting in proper time in Mashhad, each user using SMS and introducing some of his/her mental priorities to the system, will be able to select the best option depending on the timing of movement of the available public transport system. The present study adopts a newly developed method of time management which is evaluated for urban transportation considering dynamic conditions of a spatial database. For this purpose, regarding time management, processed data such as bus lines, taxi networks, and the subway system are combined in a spatial framework of a designed Mobile GIS based on a wireless network. So, multiple potential paths which end to a desirable destination.

  7. Coherent Network Optimizing of Rail-Based Urban Mass Transit

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    Ying Zhang

    2012-01-01

    Full Text Available An efficient public transport is more than ever a crucial factor when it comes to the quality of life and competitiveness of many cities and regions in Asia. In recent years, the rail-based urban mass transit has been regarded as one of the key means to overcoming the great challenges in Chinese megacities. The purpose of this study is going to develop a coherent network optimizing for rail-based urban mass transit to find the best alternatives for the user and to demonstrate how to meet sustainable development needs and to match the enormous capacity requirements simultaneously. This paper presents an introduction to the current situation of the important lines, and transfer points in the metro system Shanghai. The insufficient aspects are analyzed and evaluated; while the optimizing ideas and measurements are developed and concreted. A group of examples are used to illustrate the approach. The whole study could be used for the latest reference for other megacities which have to be confronted with the similar situations and processes with enormous dynamic travel and transport demands.

  8. Shuttle Planning for Link Closures in Urban Public Transport Networks

    DEFF Research Database (Denmark)

    van der Hurk, Evelien; Koutsopoulos, Haris N.; Wilson, Nigel

    2016-01-01

    Urban public transport systems must periodically close certain links for maintenance, which can have significant effects on the service provided to passengers. In practice, the effects of closures are mitigated by replacing the closed links with a simple shuttle service. However, alternative...... cost, which includes transfers and frequency-dependent waiting time costs. This model is applied to a shuttle design problem based on a real-world case study of the Massachusetts Bay Transportation Authority network of Boston, Massachusetts. The results show that additional shuttle routes can reduce...

  9. Detection and localization capability of an urban seismic sinkhole monitoring network

    Science.gov (United States)

    Becker, Dirk; Dahm, Torsten; Schneider, Fabian

    2017-04-01

    Microseismic events linked to underground processes in sinkhole areas might serve as precursors to larger mass dislocation or rupture events which can cause felt ground shaking or even structural damage. To identify these weak and shallow events, a sensitive local seismic monitoring network is needed. In case of an urban environment the performance of local monitoring networks is severely compromised by the high anthropogenic noise level. We study the detection and localization capability of such a network, which is already partly installed in the urban area of the city of Hamburg, Germany, within the joint project SIMULTAN (http://www.gfz-potsdam.de/en/section/near-surface-geophysics/projects/simultan/). SIMULTAN aims to monitor a known sinkhole structure and gain a better understanding of the underlying processes. The current network consists of six surface stations installed in the basement of private houses and underground structures of a research facility (DESY - Deutsches Elektronen Synchrotron). During the started monitoring campaign since 2015, no microseismic events could be unambiguously attributed to the sinkholes. To estimate the detection and location capability of the network, we calculate synthetic waveforms based on the location and mechanism of former events in the area. These waveforms are combined with the recorded urban seismic noise at the station sites. As detection algorithms a simple STA/LTA trigger and a more sophisticated phase detector are used. While the STA/LTA detector delivers stable results and is able to detect events with a moment magnitude as low as 0.35 at a distance of 1.3km from the source even under the present high noise conditions the phase detector is more sensitive but also less stable. It should be stressed that due to the local near surface conditions of the wave propagation the detections are generally performed on S- or surface waves and not on P-waves, which have a significantly lower amplitude. Due to the often

  10. Quantifying the benefits of urban forest systems as a component of the green infrastructure stormwater treatment network

    Science.gov (United States)

    Eric Kuehler; Jon Hathaway; Andrew Tirpak

    2017-01-01

    The use of green infrastructure for reducing stormwater runoff is increasingly common. One under‐studied component of the green infrastructure network is the urban forest system. Trees can play an important role as the “first line of defense” for restoring more natural hydrologic regimes in urban watersheds by intercepting rainfall, delaying runoff, infiltrating, and...

  11. MULTI-CRITERIA EVALUATION OF THE EXPANSION OF NATURAL GAS DISTRIBUTION NETWORK BY THE URBAN DYNAMICS

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    Vanessa M. Massara

    2010-01-01

    Full Text Available The objective of this work is to analyze the expansion of the infrastructure of natural gas distribution, identifying priorities from large metropolis using the energy planning based on urban design tools like urban dynamics and techniques like AHP (analytic hierarchy process. The methodology proposed uses matrices considering the relations between the concept of urban dynamics, quality of life and the possibilities of natural gas displacing other energy forms. The matrices are made up of information about social and urban development, costs of establishing the infrastructure and projections of the consumption potential in various sectors. Relating the consumption to urban development parameters and the real estate future of the areas in study, the methodology allows indicating for each district, the viability of implementing a gas network. As conclusion, the model presents the integration between the cities profile and the natural gas use, by means of a growth natural gas on districts of São Paulo City as a specific case study.

  12. Agent-Based Modeling of China's Rural-Urban Migration and Social Network Structure.

    Science.gov (United States)

    Fu, Zhaohao; Hao, Lingxin

    2018-01-15

    We analyze China's rural-urban migration and endogenous social network structures using agent-based modeling. The agents from census micro data are located in their rural origin with an empirical-estimated prior propensity to move. The population-scale social network is a hybrid one, combining observed family ties and locations of the origin with a parameter space calibrated from census, survey and aggregate data and sampled using a stepwise Latin Hypercube Sampling method. At monthly intervals, some agents migrate and these migratory acts change the social network by turning within-nonmigrant connections to between-migrant-nonmigrant connections, turning local connections to nonlocal connections, and adding among-migrant connections. In turn, the changing social network structure updates migratory propensities of those well-connected nonmigrants who become more likely to move. These two processes iterate over time. Using a core-periphery method developed from the k -core decomposition method, we identify and quantify the network structural changes and map these changes with the migration acceleration patterns. We conclude that network structural changes are essential for explaining migration acceleration observed in China during the 1995-2000 period.

  13. Agent-based modeling of China's rural-urban migration and social network structure

    Science.gov (United States)

    Fu, Zhaohao; Hao, Lingxin

    2018-01-01

    We analyze China's rural-urban migration and endogenous social network structures using agent-based modeling. The agents from census micro data are located in their rural origin with an empirical-estimated prior propensity to move. The population-scale social network is a hybrid one, combining observed family ties and locations of the origin with a parameter space calibrated from census, survey and aggregate data and sampled using a stepwise Latin Hypercube Sampling method. At monthly intervals, some agents migrate and these migratory acts change the social network by turning within-nonmigrant connections to between-migrant-nonmigrant connections, turning local connections to nonlocal connections, and adding among-migrant connections. In turn, the changing social network structure updates migratory propensities of those well-connected nonmigrants who become more likely to move. These two processes iterate over time. Using a core-periphery method developed from the k-core decomposition method, we identify and quantify the network structural changes and map these changes with the migration acceleration patterns. We conclude that network structural changes are essential for explaining migration acceleration observed in China during the 1995-2000 period.

  14. Ubiquitous Integrity via Network Integration and Parallelism—Sustaining Pedestrian/Bike Urbanism

    Directory of Open Access Journals (Sweden)

    Li-Yen Hsu

    2013-08-01

    Full Text Available Nowadays, due to the concern regarding environmental issues, establishing pedestrian/bike friendly urbanism is widely encouraged. To promote safety-assured, mobile communication environments, efficient, reliable maintenance, and information integrity need to be designed, especially in highly possibly interfered places. For busy traffic areas, regular degree-3 dedicated short range communication (DSRC networks are safety and information featured with availability, reliability, and maintainability in paths of multi-lanes. For sparsely populated areas, probes of wireless sensors are rational, especially if sensor nodes can be organized to enhance security, reliability, and flexibility. Applying alternative network topologies, such as spider-webs, generalized honeycomb tori, and cube-connected cycles, for comparing and analyzing is proposed in DSRC and cellular communications to enhance integrity in communications.

  15. Intelligent Pressure Management to Reduce Leakage in Urban Water Supply Networks, A Case Study of Sarafrazan District, Mashhad

    Directory of Open Access Journals (Sweden)

    Mohammad Soltani Asl

    2009-09-01

    Full Text Available Water losses are inevitable in urban water distribution systems. The two approaches adopted nowadays to combat this problem include management of hydraulic parameters such as pressure and leakage detection in the network. Intellitgent pressure management is a suitable technique for controlling leakage and reducing damages due to high operating pressures in a network. This paper aims to investigate the effects of pressure reduction on leakage. The EPANET 2.10 software is used to simulate the water distribution network in the Sarafrazan District,Mashhad, assuming leakage from network nodes. The results are then used to develop a pressure variation program based on the patterns obtained from the simulation, which is applied to the pressure reducing valve. The results show that pressure management can reduce nightly leakage by up to 35% while maintaining a more uniform pressure distribution. Implementation of the time-dependent pressure pattern by applying programmable pressure reducing valves in a real urban water distribution network is feasible and plays a key role in reducing water losses to leakage.

  16. Identifying socio-ecological networks in rural-urban gradients: Diagnosis of a changing cultural landscape.

    Science.gov (United States)

    Arnaiz-Schmitz, C; Schmitz, M F; Herrero-Jáuregui, C; Gutiérrez-Angonese, J; Pineda, F D; Montes, C

    2018-01-15

    Socio-ecological systems maintain reciprocal interactions between biophysical and socioeconomic structures. As a result of these interactions key essential services for society emerge. Urban expansion is a direct driver of land change and cause serious shifts in socio-ecological relationships and the associated lifestyles. The framework of rural-urban gradients has proved to be a powerful tool for ecological research about urban influences on ecosystems and on sociological issues related to social welfare. However, to date there has not been an attempt to achieve a classification of municipalities in rural-urban gradients based on socio-ecological interactions. In this paper, we developed a methodological approach that allows identifying and classifying a set of socio-ecological network configurations in the Region of Madrid, a highly dynamic cultural landscape considered one of the European hotspots in urban development. According to their socio-ecological links, the integrated model detects four groups of municipalities, ordered along a rural-urban gradient, characterized by their degree of biophysical and socioeconomic coupling and different indicators of landscape structure and social welfare. We propose the developed model as a useful tool to improve environmental management schemes and land planning from a socio-ecological perspective, especially in territories subject to intense urban transformations and loss of rurality. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Modeling urbanization patterns at a global scale with generative adversarial networks

    Science.gov (United States)

    Albert, A. T.; Strano, E.; Gonzalez, M.

    2017-12-01

    Current demographic projections show that, in the next 30 years, global population growth will mostly take place in developing countries. Coupled with a decrease in density, such population growth could potentially double the land occupied by settlements by 2050. The lack of reliable and globally consistent socio-demographic data, coupled with the limited predictive performance underlying traditional urban spatial explicit models, call for developing better predictive methods, calibrated using a globally-consistent dataset. Thus, richer models of the spatial interplay between the urban built-up land, population distribution and energy use are central to the discussion around the expansion and development of cities, and their impact on the environment in the context of a changing climate. In this talk we discuss methods for, and present an analysis of, urban form, defined as the spatial distribution of macroeconomic quantities that characterize a city, using modern machine learning methods and best-available remote-sensing data for the world's largest 25,000 cities. We first show that these cities may be described by a small set of patterns in radial building density, nighttime luminosity, and population density, which highlight, to first order, differences in development and land use across the world. We observe significant, spatially-dependent variance around these typical patterns, which would be difficult to model using traditional statistical methods. We take a first step in addressing this challenge by developing CityGAN, a conditional generative adversarial network model for simulating realistic urban forms. To guide learning and measure the quality of the simulated synthetic cities, we develop a specialized loss function for GAN optimization that incorporates standard spatial statistics used by urban analysis experts. Our framework is a stark departure from both the standard physics-based approaches in the literature (that view urban forms as fractals with a

  18. Connectivity-oriented urban projects

    NARCIS (Netherlands)

    Philibert Petit, E.

    2006-01-01

    This thesis is about connections in the built environment, networked connections for the mobility of people at the smallest scale of the urban realm: the pedestrian scale. It deals with applications of the new science of networks as a tool for observation and assessment of connectivity in the urban

  19. Urban Modality

    Directory of Open Access Journals (Sweden)

    Jorge Gil

    2016-02-01

    Full Text Available This thesis proposes a framework for evaluating the mobility potential and performance of urban areas in the city region, as an instrument to support urban development that contributes positively to regional sustainable mobility objectives. The research takes a quantitative approach, modelling and measuring the characteristics of a city-region and of its individual urban areas, in terms of travel patterns and socioeconomic characteristics of the resident population, and in terms of built environment characteristics. It then explores how the built environment defines the affordances of urban areas for travelling by particular modes of transport, i.e. its walk-ability, cycleability, drive-ability and transit-ability, by developing a typology of what I call their ‘urban modality’. And finally the work combines this typology with the socio-economic characteristics of urban areas to determine their sustainable mobility potential and performance. It focuses on the case of the Randstad region of the Netherlands and its VINEX neighbourhoods, which are an emblematic example of new urban areas created under a policy programme with sustainable mobility objectives. A key stance in this work is the understanding that the location of an urban area in the region can be indicative of its population’s travel patterns, because the built environment (infrastructural and socio-economic characteristics are interrelated and present strong regional spatial patterns. What types of urban areas support sustainable travel patterns, and what are their spatial characteristics? How do new neighbourhoods compare to the best performing urban areas, and to other areas of the same ‘modality’ type? These are some of the questions addressed in this study. There are two main contributions of this research: the methods for building and analysing integrated multimodal network models, and the framework for contextual performance evaluation using urban area typologies. The

  20. A Case-Based Reasoning for Regulation of an Urban Transportation Network

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    Karim Bouamrane

    2005-01-01

    Full Text Available This paper presents a classification-based approach to case-based reasoning. This approach has been implemented in a decision-making system for regulating an urban transportation network. Planning relies on two classification processes: strong classification to retrieve a similar planning perturbation and smooth classification when the former fails. Smooth classification is an original mechanism that can become of general use in case-based reasoning. We discuss in this paper the two processes from general and applicative point of view.

  1. Application of Source-Sink Landscape Influence Values to Commuter Traffic: A Case Study of Xiamen Island

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    Tong Wu

    2017-12-01

    Full Text Available Landscape patterns are closely related to ecological processes. Different spatial scales and research methods may lead to different results. Therefore, it is crucial to choose suitable research methods when studying different landscape patterns and ecological processes. In the present study, the methods of source-sink landscape theory were applied to the interactions between urban landscape characteristics and commuter traffic behavior around the arterial roads in Xiamen Island. After classification of land use types using remote sensing images from the IKONOS satellite and ArcGIS software (ESRI, Redlands, CA, USA, the landscape patterns of areas surrounding arterial roads (within 1 km were evaluated using source-sink landscape influence (SLI. The results showed that Xiamen Island’s urban expressway had the highest SLI value (0.191, followed by the state highways (0.067, the provincial highways (0.030, and the county roads (0.025. When considering all road types, the correlation between a road’s SLI value and its commuter traffic flow was 0.684. This result was explained by three observations: (1 The contribution of the core area of each landscape pattern to traffic flow was positively correlated with the traffic flow. (2 Areas surrounding the urban expressway and the state highways had lower values for Shannon’s diversity index, indicating that these areas had a lower degree of landscape fragmentation. (3 The landscape patterns surrounding the urban expressway and the state highways were more concentrated and complex than those around other road types. The application of source-sink landscape pattern theory allows for researchers to integrate the relationships between landscape patterns surrounding roads and commuter traffic flow on those roads and to analyze the reasons for these relationships.

  2. Modeling and Density Estimation of an Urban Freeway Network Based on Dynamic Graph Hybrid Automata.

    Science.gov (United States)

    Chen, Yangzhou; Guo, Yuqi; Wang, Ying

    2017-03-29

    In this paper, in order to describe complex network systems, we firstly propose a general modeling framework by combining a dynamic graph with hybrid automata and thus name it Dynamic Graph Hybrid Automata (DGHA). Then we apply this framework to model traffic flow over an urban freeway network by embedding the Cell Transmission Model (CTM) into the DGHA. With a modeling procedure, we adopt a dual digraph of road network structure to describe the road topology, use linear hybrid automata to describe multi-modes of dynamic densities in road segments and transform the nonlinear expressions of the transmitted traffic flow between two road segments into piecewise linear functions in terms of multi-mode switchings. This modeling procedure is modularized and rule-based, and thus is easily-extensible with the help of a combination algorithm for the dynamics of traffic flow. It can describe the dynamics of traffic flow over an urban freeway network with arbitrary topology structures and sizes. Next we analyze mode types and number in the model of the whole freeway network, and deduce a Piecewise Affine Linear System (PWALS) model. Furthermore, based on the PWALS model, a multi-mode switched state observer is designed to estimate the traffic densities of the freeway network, where a set of observer gain matrices are computed by using the Lyapunov function approach. As an example, we utilize the PWALS model and the corresponding switched state observer to traffic flow over Beijing third ring road. In order to clearly interpret the principle of the proposed method and avoid computational complexity, we adopt a simplified version of Beijing third ring road. Practical application for a large-scale road network will be implemented by decentralized modeling approach and distributed observer designing in the future research.

  3. Multi-agent control of urban transportation networks and of hybrid systems with limited information sharing

    NARCIS (Netherlands)

    Luo, R.

    2016-01-01

    This thesis aims at developing efficient methods for control of large-scale systems by employing state-of-the-art control methods and optimization techniques. This thesis is divided into two parts. In the first part, we address dynamic traffic routing for urban transportation networks. In the second

  4. The visualization and analysis of urban facility pois using network kernel density estimation constrained by multi-factors

    Directory of Open Access Journals (Sweden)

    Wenhao Yu

    Full Text Available The urban facility, one of the most important service providers is usually represented by sets of points in GIS applications using POI (Point of Interest model associated with certain human social activities. The knowledge about distribution intensity and pattern of facility POIs is of great significance in spatial analysis, including urban planning, business location choosing and social recommendations. Kernel Density Estimation (KDE, an efficient spatial statistics tool for facilitating the processes above, plays an important role in spatial density evaluation, because KDE method considers the decay impact of services and allows the enrichment of the information from a very simple input scatter plot to a smooth output density surface. However, the traditional KDE is mainly based on the Euclidean distance, ignoring the fact that in urban street network the service function of POI is carried out over a network-constrained structure, rather than in a Euclidean continuous space. Aiming at this question, this study proposes a computational method of KDE on a network and adopts a new visualization method by using 3-D "wall" surface. Some real conditional factors are also taken into account in this study, such as traffic capacity, road direction and facility difference. In practical works the proposed method is implemented in real POI data in Shenzhen city, China to depict the distribution characteristic of services under impacts of multi-factors.

  5. Use of neural networks for monitoring surface water quality changes in a neotropical urban stream.

    Science.gov (United States)

    da Costa, Andréa Oliveira Souza; Silva, Priscila Ferreira; Sabará, Millôr Godoy; da Costa, Esly Ferreira

    2009-08-01

    This paper reports the using of neural networks for water quality analysis in a tropical urban stream before (2002) and after sewerage building and the completion of point-source control-based sanitation program (2003). Mathematical modeling divided water quality data in two categories: (a) input of some in situ water quality variables (temperature, pH, O2 concentration, O2 saturation and electrical conductivity) and (b) water chemical composition (N-NO2(-); N-NO3(-); N-NH4(+) Total-N; P-PO4(3-); K+; Ca2+; Mg+2; Cu2+; Zn2+ and Fe+3) as the output from tested models. Stream water data come from fortnightly sampling in five points along the Ipanema stream (Southeast Brazil, Minas Gerais state) plus two points downstream and upstream Ipanema discharge into Doce River. Once the best models are consistent with variables behavior we suggest that neural networking shows potential as a methodology to enhance guidelines for urban streams restoration, conservation and management.

  6. A statistical intercomparison between "urban" and "rural" precipitation chemistry data from greater Manchester and two nearby secondary national network sites in the United Kingdom

    Science.gov (United States)

    Lee, David S.; Longhurst, James W. S.

    Precipitation chemistry data from a dense urban monitoring network in Greater Manchester, northwest England, were compared with interpolated values from the U.K. secondary national acid deposition monitoring network for the year 1988. Differences were found to be small. However, when data from individual sites from the Greater Manchester network were compared with data from the two nearest secondary national network sites, significant differences were found using simple and complex statistical analyses. Precipitation chemistry at rural sites could be similar to that at urban sites, but the sources of some ions were thought to be different. The synoptic-scale gradients of precipitation chemistry, as shown by the secondary national network, also accounted for some of the differences.

  7. Urban Growth Modeling Using AN Artificial Neural Network a Case Study of Sanandaj City, Iran

    Science.gov (United States)

    Mohammady, S.; Delavar, M. R.; Pahlavani, P.

    2014-10-01

    Land use activity is a major issue and challenge for town and country planners. Modelling and managing urban growth is a complex problem. Cities are now recognized as complex, non-linear and dynamic process systems. The design of a system that can handle these complexities is a challenging prospect. Local governments that implement urban growth models need to estimate the amount of urban land required in the future given anticipated growth of housing, business, recreation and other urban uses within the boundary. There are so many negative implications related with the type of inappropriate urban development such as increased traffic and demand for mobility, reduced landscape attractively, land use fragmentation, loss of biodiversity and alterations of the hydrological cycle. The aim of this study is to use the Artificial Neural Network (ANN) to make a powerful tool for simulating urban growth patterns. Our study area is Sanandaj city located in the west of Iran. Landsat imageries acquired at 2000 and 2006 are used. Dataset were used include distance to principle roads, distance to residential areas, elevation, slope, distance to green spaces and distance to region centers. In this study an appropriate methodology for urban growth modelling using satellite remotely sensed data is presented and evaluated. Percent Correct Match (PCM) and Figure of Merit were used to evaluate ANN results.

  8. URBAN GROWTH MODELING USING AN ARTIFICIAL NEURAL NETWORK A CASE STUDY OF SANANDAJ CITY, IRAN

    Directory of Open Access Journals (Sweden)

    S. Mohammady

    2014-10-01

    Full Text Available Land use activity is a major issue and challenge for town and country planners. Modelling and managing urban growth is a complex problem. Cities are now recognized as complex, non-linear and dynamic process systems. The design of a system that can handle these complexities is a challenging prospect. Local governments that implement urban growth models need to estimate the amount of urban land required in the future given anticipated growth of housing, business, recreation and other urban uses within the boundary. There are so many negative implications related with the type of inappropriate urban development such as increased traffic and demand for mobility, reduced landscape attractively, land use fragmentation, loss of biodiversity and alterations of the hydrological cycle. The aim of this study is to use the Artificial Neural Network (ANN to make a powerful tool for simulating urban growth patterns. Our study area is Sanandaj city located in the west of Iran. Landsat imageries acquired at 2000 and 2006 are used. Dataset were used include distance to principle roads, distance to residential areas, elevation, slope, distance to green spaces and distance to region centers. In this study an appropriate methodology for urban growth modelling using satellite remotely sensed data is presented and evaluated. Percent Correct Match (PCM and Figure of Merit were used to evaluate ANN results.

  9. A Survey on Urban Traffic Management System Using Wireless Sensor Networks

    Science.gov (United States)

    Nellore, Kapileswar; Hancke, Gerhard P.

    2016-01-01

    Nowadays, the number of vehicles has increased exponentially, but the bedrock capacities of roads and transportation systems have not developed in an equivalent way to efficiently cope with the number of vehicles traveling on them. Due to this, road jamming and traffic correlated pollution have increased with the associated adverse societal and financial effect on different markets worldwide. A static control system may block emergency vehicles due to traffic jams. Wireless Sensor networks (WSNs) have gained increasing attention in traffic detection and avoiding road congestion. WSNs are very trendy due to their faster transfer of information, easy installation, less maintenance, compactness and for being less expensive compared to other network options. There has been significant research on Traffic Management Systems using WSNs to avoid congestion, ensure priority for emergency vehicles and cut the Average Waiting Time (AWT) of vehicles at intersections. In recent decades, researchers have started to monitor real-time traffic using WSNs, RFIDs, ZigBee, VANETs, Bluetooth devices, cameras and infrared signals. This paper presents a survey of current urban traffic management schemes for priority-based signalling, and reducing congestion and the AWT of vehicles. The main objective of this survey is to provide a taxonomy of different traffic management schemes used for avoiding congestion. Existing urban traffic management schemes for the avoidance of congestion and providing priority to emergency vehicles are considered and set the foundation for further research. PMID:26828489

  10. A Five-Year School Building and Future Sites Program 1966-1970.

    Science.gov (United States)

    1965

    Five-year school building and site needs and related financial requirements are summarized for Milwaukee's schools. Educational policies concerning the school building program are stated, and consideration is given to factors affecting school board needs such as birth rate, public housing projects, urban renewal, highways, and expressways. School…

  11. New Integration Period? Changing Tendencies of the Urban Network in South East Europe

    Directory of Open Access Journals (Sweden)

    Szilárd Rácz

    2014-09-01

    Full Text Available The past two decades have brought basic changes in the whole Balkan Peninsula, where spatial structures and settlement network were not devoid of changes either. Due to the change of the economic, political and social regime and the new borders spatial structures became differentiated along new factors. Cooperation programs of the Euro-Atlantic integration hold many new challenges and opportunities. Historical and political literature studying the single countries’ transformation is large and far reaching, however, a settlement network and spatial structure focused overview has been, so far, missing from the range of researches. The aim of this study is to examine the urban features and the spatial transition of the Balkan states.

  12. Stormwater management network effectiveness and implications for urban watershed function: A critical review

    Science.gov (United States)

    Jefferson, Anne J.; Bhaskar, Aditi S.; Hopkins, Kristina G.; Fanelli, Rosemary; Avellaneda, Pedro M.; McMillan, Sara K.

    2017-01-01

    Deleterious effects of urban stormwater are widely recognized. In several countries, regulations have been put into place to improve the conditions of receiving water bodies, but planning and engineering of stormwater control is typically carried out at smaller scales. Quantifying cumulative effectiveness of many stormwater control measures on a watershed scale is critical to understanding how small-scale practices translate to urban river health. We review 100 empirical and modelling studies of stormwater management effectiveness at the watershed scale in diverse physiographic settings. Effects of networks with stormwater control measures (SCMs) that promote infiltration and harvest have been more intensively studied than have detention-based SCM networks. Studies of peak flows and flow volumes are common, whereas baseflow, groundwater recharge, and evapotranspiration have received comparatively little attention. Export of nutrients and suspended sediments have been the primary water quality focus in the United States, whereas metals, particularly those associated with sediments, have received greater attention in Europe and Australia. Often, quantifying cumulative effects of stormwater management is complicated by needing to separate its signal from the signal of urbanization itself, innate watershed characteristics that lead to a range of hydrologic and water quality responses, and the varying functions of multiple types of SCMs. Biases in geographic distribution of study areas, and size and impervious surface cover of watersheds studied also limit our understanding of responses. We propose hysteretic trajectories for how watershed function responds to increasing imperviousness and stormwater management. Even where impervious area is treated with SCMs, watershed function may not be restored to its predevelopment condition because of the lack of treatment of all stormwater generated from impervious surfaces; non-additive effects of individual SCMs; and

  13. Using Multivariate Adaptive Regression Spline and Artificial Neural Network to Simulate Urbanization in Mumbai, India

    Science.gov (United States)

    Ahmadlou, M.; Delavar, M. R.; Tayyebi, A.; Shafizadeh-Moghadam, H.

    2015-12-01

    Land use change (LUC) models used for modelling urban growth are different in structure and performance. Local models divide the data into separate subsets and fit distinct models on each of the subsets. Non-parametric models are data driven and usually do not have a fixed model structure or model structure is unknown before the modelling process. On the other hand, global models perform modelling using all the available data. In addition, parametric models have a fixed structure before the modelling process and they are model driven. Since few studies have compared local non-parametric models with global parametric models, this study compares a local non-parametric model called multivariate adaptive regression spline (MARS), and a global parametric model called artificial neural network (ANN) to simulate urbanization in Mumbai, India. Both models determine the relationship between a dependent variable and multiple independent variables. We used receiver operating characteristic (ROC) to compare the power of the both models for simulating urbanization. Landsat images of 1991 (TM) and 2010 (ETM+) were used for modelling the urbanization process. The drivers considered for urbanization in this area were distance to urban areas, urban density, distance to roads, distance to water, distance to forest, distance to railway, distance to central business district, number of agricultural cells in a 7 by 7 neighbourhoods, and slope in 1991. The results showed that the area under the ROC curve for MARS and ANN was 94.77% and 95.36%, respectively. Thus, ANN performed slightly better than MARS to simulate urban areas in Mumbai, India.

  14. Epidemic Wave Dynamics Attributable to Urban Community Structure: A Theoretical Characterization of Disease Transmission in a Large Network

    Science.gov (United States)

    Eggo, Rosalind M; Lenczner, Michael

    2015-01-01

    Background Multiple waves of transmission during infectious disease epidemics represent a major public health challenge, but the ecological and behavioral drivers of epidemic resurgence are poorly understood. In theory, community structure—aggregation into highly intraconnected and loosely interconnected social groups—within human populations may lead to punctuated outbreaks as diseases progress from one community to the next. However, this explanation has been largely overlooked in favor of temporal shifts in environmental conditions and human behavior and because of the difficulties associated with estimating large-scale contact patterns. Objective The aim was to characterize naturally arising patterns of human contact that are capable of producing simulated epidemics with multiple wave structures. Methods We used an extensive dataset of proximal physical contacts between users of a public Wi-Fi Internet system to evaluate the epidemiological implications of an empirical urban contact network. We characterized the modularity (community structure) of the network and then estimated epidemic dynamics under a percolation-based model of infectious disease spread on the network. We classified simulated epidemics as multiwave using a novel metric and we identified network structures that were critical to the network’s ability to produce multiwave epidemics. Results We identified robust community structure in a large, empirical urban contact network from which multiwave epidemics may emerge naturally. This pattern was fueled by a special kind of insularity in which locally popular individuals were not the ones forging contacts with more distant social groups. Conclusions Our results suggest that ordinary contact patterns can produce multiwave epidemics at the scale of a single urban area without the temporal shifts that are usually assumed to be responsible. Understanding the role of community structure in epidemic dynamics allows officials to anticipate epidemic

  15. Urban Growth Modelling with Artificial Neural Network and Logistic Regression. Case Study: Sanandaj City, Iran

    Directory of Open Access Journals (Sweden)

    SASSAN MOHAMMADY

    2013-01-01

    Full Text Available Cities have shown remarkable growth due to attraction, economic, social and facilities centralization in the past few decades. Population and urban expansion especially in developing countries, led to lack of resources, land use change from appropriate agricultural land to urban land use and marginalization. Under these circumstances, land use activity is a major issue and challenge for town and country planners. Different approaches have been attempted in urban expansion modelling. Artificial Neural network (ANN models are among knowledge-based models which have been used for urban growth modelling. ANNs are powerful tools that use a machine learning approach to quantify and model complex behaviour and patterns. In this research, ANN and logistic regression have been employed for interpreting urban growth modelling. Our case study is Sanandaj city and we used Landsat TM and ETM+ imageries acquired at 2000 and 2006. The dataset used includes distance to main roads, distance to the residence region, elevation, slope, and distance to green space. Percent Area Match (PAM obtained from modelling of these changes with ANN is equal to 90.47% and the accuracy achieved for urban growth modelling with Logistic Regression (LR is equal to 88.91%. Percent Correct Match (PCM and Figure of Merit for ANN method were 91.33% and 59.07% and then for LR were 90.84% and 57.07%, respectively.

  16. An optimal general type-2 fuzzy controller for Urban Traffic Network

    DEFF Research Database (Denmark)

    Khooban, Mohammad Hassan; Vafamand, Navid; Liaghat, Alireza

    2017-01-01

    Urban traffic network model is illustrated by state-charts and object-diagram. However, they have limitations to show the behavioral perspective of the Traffic Information flow. Consequently, a state space model is used to calculate the half-value waiting time of vehicles. In this study......, a combination of the general type-2 fuzzy logic sets and the Modified Backtracking Search Algorithm (MBSA) techniques are used in order to control the traffic signal scheduling and phase succession so as to guarantee a smooth flow of traffic with the least wait times and average queue length. The parameters...

  17. Effects of cost metric on cost-effectiveness of protected-area network design in urban landscapes.

    Science.gov (United States)

    Burkhalter, J C; Lockwood, J L; Maslo, B; Fenn, K H; Leu, K

    2016-04-01

    A common goal in conservation planning is to acquire areas that are critical to realizing biodiversity goals in the most cost-effective manner. The way monetary acquisition costs are represented in such planning is an understudied but vital component to realizing cost efficiencies. We sought to design a protected-area network within a forested urban region that would protect 17 birds of conservation concern. We compared the total costs and spatial structure of the optimal protected-area networks produced using three acquisition-cost surrogates (area, agricultural land value, and tax-assessed land value). Using the tax-assessed land values there was a 73% and 78% cost savings relative to networks derived using area or agricultural land value, respectively. This cost reduction was due to the considerable heterogeneity in acquisition costs revealed in tax-assessed land values, especially for small land parcels, and the corresponding ability of the optimization algorithm to identify lower-cost parcels for inclusion that had equal value to our target species. Tax-assessed land values also reflected the strong spatial differences in acquisition costs (US$0.33/m(2)-$55/m(2)) and thus allowed the algorithm to avoid inclusion of high-cost parcels when possible. Our results add to a nascent but growing literature that suggests conservation planners must consider the cost surrogate they use when designing protected-area networks. We suggest that choosing cost surrogates that capture spatial- and size-dependent heterogeneity in acquisition costs may be relevant to establishing protected areas in urbanizing ecosystems. © 2015 Society for Conservation Biology.

  18. Comprehensive Forecast of Urban Water-Energy Demand Based on a Neural Network Model

    Directory of Open Access Journals (Sweden)

    Ziyi Yin

    2018-03-01

    Full Text Available Water-energy nexus has been a popular topic of rese arch in recent years. The relationships between the demand for water resources and energy are intense and closely connected in urban areas. The primary, secondary, and tertiary industry gross domestic product (GDP, the total population, the urban population, annual precipitation, agricultural and industrial water consumption, tap water supply, the total discharge of industrial wastewater, the daily sewage treatment capacity, total and domestic electricity consumption, and the consumption of coal in industrial enterprises above the designed size were chosen as input indicators. A feedforward artificial neural network model (ANN based on a back-propagation algorithm with two hidden layers was constructed to combine urban water resources with energy demand. This model used historical data from 1991 to 2016 from Wuxi City, eastern China. Furthermore, a multiple linear regression model (MLR was introduced for comparison with the ANN. The results show the following: (a The mean relative error values of the forecast and historical urban water-energy demands are 1.58 % and 2.71%, respectively; (b The predicted water-energy demand value for 2020 is 4.843 billion cubic meters and 47.561 million tons of standard coal equivalent; (c The predicted water-energy demand value in the year 2030 is 5.887 billion cubic meters and 60.355 million tons of standard coal equivalent; (d Compared with the MLR, the ANN performed better in fitting training data, which achieved a more satisfactory accuracy and may provide a reference for urban water-energy supply planning decisions.

  19. COST Action TU1206 "SUB-URBAN - A European network to improve understanding and use of the ground beneath our cities"

    Science.gov (United States)

    Campbell, Diarmad; de Beer, Johannes; Lawrence, David; van der Meulen, Michiel; Mielby, Susie; Hay, David; Scanlon, Ray; Campenhout, Ignace; Taugs, Renate; Eriksson, Ingelov

    2014-05-01

    Sustainable urbanisation is the focus of SUB-URBAN, a European Cooperation in Science and Technology (COST) Action TU1206 - A European network to improve understanding and use of the ground beneath our cities. This aims to transform relationships between experts who develop urban subsurface geoscience knowledge - principally national Geological Survey Organisations (GSOs), and those who can most benefit from it - urban decision makers, planners, practitioners and the wider research community. Under COST's Transport and Urban Development Domain, SUB-URBAN has established a network of GSOs and other researchers in over 20 countries, to draw together and evaluate collective urban geoscience research in 3D/4D characterisation, prediction and visualisation. Knowledge exchange between researchers and City-partners within 'SUB-URBAN' is already facilitating new city-scale subsurface projects, and is developing a tool-box of good-practice guidance, decision-support tools, and cost-effective methodologies that are appropriate to local needs and circumstances. These are intended to act as catalysts in the transformation of relationships between geoscientists and urban decision-makers more generally. As a result, the importance of the urban sub-surface in the sustainable development of our cities will be better appreciated, and the conflicting demands currently placed on it will be acknowledged, and resolved appropriately. Existing city-scale 3D/4D model exemplars are being developed by partners in the UK (Glasgow, London), Germany (Hamburg) and France (Paris). These draw on extensive ground investigation (10s-100s of thousands of boreholes) and other data. Model linkage enables prediction of groundwater, heat, SuDS, and engineering properties. Combined subsurface and above-ground (CityGML, BIMs) models are in preparation. These models will provide valuable tools for more holistic urban planning; identifying subsurface opportunities and saving costs by reducing uncertainty in

  20. Reliability Indicators of Urban Electric Network Schemes for Supply of Second and Third Category Consumers

    Directory of Open Access Journals (Sweden)

    M. A. Korotkevich

    2012-01-01

    Full Text Available The paper considers two schemes of the urban distributive electric network for supply of the second and third category consumers for whom indicators of reliability have been determined.As for a network scheme of the 2nd category it has been determined that while installing low-oil and vacuum switches at a distributive point the most remote transformer substation has the highest non-availability  factor which is higher of the corresponding non-availability  factor of the nearest transformer substation by 1,21–1,23 fold  accordingly.As for a network scheme of the 3rd category consumers it has been obtained the data that reliability of consumers receiving supply from bus-bars of transformer substations with 0,38 kW voltage changes  significantly (by 1,2–1,9-fold while changing a breakpoint of the network with 10 kW voltage.

  1. A Visual Analytics Approach for Extracting Spatio-Temporal Urban Mobility Information from Mobile Network Traffic

    Directory of Open Access Journals (Sweden)

    Euro Beinat

    2012-11-01

    Full Text Available In this paper we present a visual analytics approach for deriving spatio-temporal patterns of collective human mobility from a vast mobile network traffic data set. More than 88 million movements between pairs of radio cells—so-called handovers—served as a proxy for more than two months of mobility within four urban test areas in Northern Italy. In contrast to previous work, our approach relies entirely on visualization and mapping techniques, implemented in several software applications. We purposefully avoid statistical or probabilistic modeling and, nonetheless, reveal characteristic and exceptional mobility patterns. The results show, for example, surprising similarities and symmetries amongst the total mobility and people flows between the test areas. Moreover, the exceptional patterns detected can be associated to real-world events such as soccer matches. We conclude that the visual analytics approach presented can shed new light on large-scale collective urban mobility behavior and thus helps to better understand the “pulse” of dynamic urban systems.

  2. Review of the Literature: A Rural-Urban Comparison of Social Networks of Older Adults Living With HIV.

    Science.gov (United States)

    Gannon, Brittany N; Stacciarini, Jeanne-Marie R

    2016-01-01

    Globally, aging populations and older persons living with HIV (OPLWH) are emerging socioeconomic and health care concerns. Aging adults living in rural communities have less access to and lower utilization of health care services; they rely heavily on available peer and family networks. Although social networks have been linked to positive mental and physical health outcomes, there is a lack of understanding about social networks in rural-dwelling OPLWH. The purpose of this integrative literature review was to compare emerging themes in the social network components of rural versus urban-dwelling OPLWH and network benefits and barriers. Overarching themes include: limited and/or fragile networks, social inclusion versus social isolation, social capital, and health outcomes. Results demonstrate an overall lack of rural-focused research on OPLWH and a universal lack of informal and formal networks due to isolation, lack of health care services, and omnipresent HIV stigma. Copyright © 2016 Association of Nurses in AIDS Care. Published by Elsevier Inc. All rights reserved.

  3. Urban acid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Conlan, D.E.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E.

    1991-07-01

    In this document results from the Greater Manchester Acid Deposition Survey (GMADS), an urban precipitation chemistry network, for 1990 are presented. Full analytical methods are described along with the precision and accuracy of the methods used. The spatial variability of precipitation chemistry and deposition over this urban region was investigated using a network of twenty collectors. Concentrations of non marine sulphate, ammonium, calcium and hydrogen, and nitrogen dioxide gas concentrations all show significant spatial variability. The spatial variability of the deposition rates of non marine sulphate, nitrate, ammonium, hydrogen and calcium were significant. (Author).

  4. URBAN REGIONAL NETWORKS AND TERRITORIAL DEVELOPMENT: AN ANALYSIS OF “MINAS GERAIS” NORTHWEST TERRITORY IN RECENT YEARS

    Directory of Open Access Journals (Sweden)

    Clesio Marcelino Jesus

    2016-09-01

    Full Text Available This article aims to show that the establishment of a rural area as a cutout for implementation of public policies for development needs to consider the configuration of the urban network of the municipalities that compose it, identifying what are the hierarchical relationships between the municipalities that make up the territory and if the most dynamic centers radiate influence to the whole. We present the case study of the Northwest Territory of Minas, where were identified various limits for the implementation of territorial development policies. In this article it is shown that such limits are manifested largely because the territory groups municipalities that have different polarizations and establish differentiated functional relationships within the regional urban network. It was found that in this territorial clipping are articulated different social production systems and that the delimitation of the territory does not match even with the regionalization of state and federal agencies.

  5. How to evaluate network initiatives in urban planning - studying area based initiatives (Kvarterløft) in Denmark"

    DEFF Research Database (Denmark)

    Agger, Annika

    This article presents a theoretical and empirical contribution to the discussions of more inclusive and participatory modes of governing that are taking place in many western countries. It develops a critical evaluation framework for assessing the qualities and outcomes of citizens participating ...... planning process in a urban environment in Denmark that focus on improving deprived urban neighbourhoods by mobilising networks....... in collaborative planning processes. This is done by introducing the concepts of institutional capacity and empowerment that derives from different fields of literature, but that covers different perspectives when assessing citizen participation. Some of the central questions raised in the article are: What...

  6. Functional Polycentrism and Urban Network Development in the Greater South East UK: Evidence from Commuting Patterns, 1981-2001

    NARCIS (Netherlands)

    B. de Goei (Bastiaan); M.J. Burger (Martijn); F.G. van Oort (Frank); M. Kitson (Michael)

    2009-01-01

    textabstractIn contemporary literature on changing urban systems, it is often argued that the traditional central place conceptualisation is outdated and should be replaced by a network view that emphasises the increasing criss-crossing pattern of interdependencies between spatial units. This paper

  7. Intelligent Pressure Management to Reduce Leakage in Urban Water Supply Networks, A Case Study of Sarafrazan District, Mashhad

    OpenAIRE

    Mohammad Soltani Asl; Mahmoud Faghfour Maghrebi

    2009-01-01

    Water losses are inevitable in urban water distribution systems. The two approaches adopted nowadays to combat this problem include management of hydraulic parameters such as pressure and leakage detection in the network. Intellitgent pressure management is a suitable technique for controlling leakage and reducing damages due to high operating pressures in a network. This paper aims to investigate the effects of pressure reduction on leakage. The EPANET 2.10 software is used to simulate the w...

  8. Assessment of the service performance of drainage system and transformation of pipeline network based on urban combined sewer system model.

    Science.gov (United States)

    Peng, Hai-Qin; Liu, Yan; Wang, Hong-Wu; Ma, Lu-Ming

    2015-10-01

    In recent years, due to global climate change and rapid urbanization, extreme weather events occur to the city at an increasing frequency. Waterlogging is common because of heavy rains. In this case, the urban drainage system can no longer meet the original design requirements, resulting in traffic jams and even paralysis and post a threat to urban safety. Therefore, it provides a necessary foundation for urban drainage planning and design to accurately assess the capacity of the drainage system and correctly simulate the transport effect of drainage network and the carrying capacity of drainage facilities. This study adopts InfoWorks Integrated Catchment Management (ICM) to present the two combined sewer drainage systems in Yangpu District, Shanghai (China). The model can assist the design of the drainage system. Model calibration is performed based on the historical rainfall events. The calibrated model is used for the assessment of the outlet drainage and pipe loads for the storm scenario currently existing or possibly occurring in the future. The study found that the simulation and analysis results of the drainage system model were reliable. They could fully reflect the service performance of the drainage system in the study area and provide decision-making support for regional flood control and transformation of pipeline network.

  9. Limits—Urban Density and Mobility Networks in West Berlin during the Period of Containment

    Directory of Open Access Journals (Sweden)

    Vanessa Miriam Carlow

    2014-10-01

    Full Text Available If space may be conceptualized as a natural resource, much like gas, oil, or minerals, then its production and use can also be thought of as something to be properly managed, taken care of, and not wasted. Limiting the expansion of the footprint of built-up land in urban areas forces this particular resource (space to be used more efficiently—in a sense, compelling it to be more creative and productive. These spatial constraints on urban areas generate different kinds of densification processes within the existing city, propagating densification, and with it new patterns and uses in urban development, as well as novel approaches to mitigating the hazards of dense urban environments. This paper examines the case of how spatial containment in West Berlin during the period of the Berlin Wall (1961–1989 produced such outcomes. West Berlin during this period can be considered a unique case of spatial containment, where a relatively large and vibrant modern city had to work around a clear and indelible limit to its physical expansion. This paper will discuss ways in which the containment influenced patterns of development in West Berlin toward densification and connectivity, focusing on the expansion of its infrastructural networks, and discuss the development of a new building culture around transformation and densification, including hybrid architectures and mitigation devices to deal with difficult sites produced by the densification.

  10. Parametric laws to model urban pollutant dispersion with a street network approach

    Science.gov (United States)

    Soulhac, L.; Salizzoni, P.; Mejean, P.; Perkins, R. J.

    2013-03-01

    This study discusses the reliability of the street network approach for pollutant dispersion modelling in urban areas. This is essentially based on a box model, with parametric relations that explicitly model the main phenomena that contribute to the street canyon ventilation: the mass exchanges between the street and the atmosphere, the pollutant advection along the street axes and the pollutant transfer at street intersections. In the first part of the paper the focus is on the development of a model for the bulk transfer street/atmosphere, which represents the main ventilation mechanisms for wind direction that are almost perpendicular to the axis of the street. We then discuss the role of the advective transfer along the street axis on its ventilation, depending on the length of the street and the direction of the external wind. Finally we evaluate the performances of a box model integrating parametric exchange laws for these transfer phenomena. To that purpose we compare the prediction of the model to wind tunnel experiments of pollutant dispersion within a street canyon placed in an idealised urban district.

  11. Integrated Urban Flood Analysis considering Optimal Operation of Flood Control Facilities in Urban Drainage Networks

    Science.gov (United States)

    Moon, Y. I.; Kim, M. S.; Choi, J. H.; Yuk, G. M.

    2017-12-01

    eavy rainfall has become a recent major cause of urban area flooding due to the climate change and urbanization. To prevent property damage along with casualties, a system which can alert and forecast urban flooding must be developed. Optimal performance of reducing flood damage can be expected of urban drainage facilities when operated in smaller rainfall events over extreme ones. Thus, the purpose of this study is to execute: A) flood forecasting system using runoff analysis based on short term rainfall; and B) flood warning system which operates based on the data from pump stations and rainwater storage in urban basins. In result of the analysis, it is shown that urban drainage facilities using short term rainfall forecasting data by radar will be more effective to reduce urban flood damage than using only the inflow data of the facility. Keywords: Heavy Rainfall, Urban Flood, Short-term Rainfall Forecasting, Optimal operating of urban drainage facilities. AcknowledgmentsThis research was supported by a grant (17AWMP-B066744-05) from Advanced Water Management Research Program (AWMP) funded by Ministry of Land, Infrastructure and Transport of Korean government.

  12. Performative Urban Environments

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Thomsen, Bo Stjerne

    2008-01-01

    The chapter explores how temporary architectural structures can become media for bottom-up approaches to urban development. Urban interactions in the city developed from the sidewalks were seen as locally bounded neighbourhoods. However, with the advent of contemporary network technologies....... In investigating architectural media-constructions the paper draws on the notion of ‘Capsular Civilization'. Arguing that architectural capsules in the cities' in-between spaces may become the media and places of meaningful interaction by establishing a feedback loop guided by social interaction. Architecture thus......-organizing, communicative environments for an organized complexity between flows of local interactions and network behaviour. The chapter applies the concepts on the case of the Pavilion Project, NoRA, built for the 10th International Architecture Biennale in Venice for the network of Food College Denmark....

  13. New Challenges for Urban History: Culture, Networks, Globalization

    Directory of Open Access Journals (Sweden)

    Hietala, Marjatta

    2012-12-01

    Full Text Available Urban history is a very lively and dynamic research field, showing strict parallelism with the fast increasing of the urban population. Today, competitiveness is one of the key aims for cities in the globalized world. Factors such as accessibility and infrastructure, industry, human capital, innovation, and investment, green spaces, affordable housing, business support and quality of education are necessaries. However, the OECD recognizes three dilemmas in this strategic vision, concerning the spill over of metro-regions, the public strategic vision, and the relationship between economic dynamism and the liveable city. Today urban historians are facing some general challenges: comparative aspects are needed; also interdisciplinarity to develop cooperation between disciplines; and for maintaining the professional status of academic urban history. The expanding networks between towns and cities, and the meeting places as conferences and exhibitions are considered, as they are the multitudinous challenges and threats, especially for those cities suffering continuously of major natural and man-made disasters. Moreover, new amalgams of hazard are being created in metropolitan areas with overlapping natural, technological, biological and social risks, exposing more people and places, needing safety and security.

    La historia urbana es un campo de investigación muy vivo y dinámico, mostrando un paralelismo estricto con el rápido incremento de la población urbana. La competencia es hoy uno de los objetivos claves para las ciudades en el mundo globalizado. Factores tales como la accesibilidad y las infraestructuras, la industria, el capital humano, la innovación y la inversión, los espacios verdes, la vivienda accesible, el apoyo a los negocios y la calidad de la educación son necesarios. Sin embargo, la OCDE reconoce tres dilemas en esa visión estratégica, el desarrollo de las metrópolis, la visión estratégica pública y la relaci

  14. Integrated Urban Wastewater System Data Network - Data network system : Diagnostic Report Cali, Colombia

    NARCIS (Netherlands)

    Unesco-IHE

    2008-01-01

    The pressure on the Urban Wastewater Systems (UWwS) increases as urbanization continues relentlessly and climate change appears to lead to more extreme rainfall events. These pressures have a negative effect on the efficiency of UWwS to reduce the urban pollution reaching water-receiving systems.

  15. Catchment & sewer network simulation model to benchmark control strategies within urban wastewater systems

    DEFF Research Database (Denmark)

    Saagi, Ramesh; Flores Alsina, Xavier; Fu, Guangtao

    2016-01-01

    This paper aims at developing a benchmark simulation model to evaluate control strategies for the urban catchment and sewer network. Various modules describing wastewater generation in the catchment, its subsequent transport and storage in the sewer system are presented. Global/local overflow based...... evaluation criteria describing the cumulative and acute effects are presented. Simulation results show that the proposed set of models is capable of generating daily, weekly and seasonal variations as well as describing the effect of rain events on wastewater characteristics. Two sets of case studies...

  16. Modeling e-logistics for urban B2C in Europe

    OpenAIRE

    Galván, Dante; Robusté Antón, Francesc; Estrada Romeu, Miguel Ángel; Campos Cacheda, Jose Magin

    2005-01-01

    Major cities need to carry out good delivery operations that coexist with the rest of urban functions. The efficiency in city organisation depends directly on the proper management of logistic networks. In this context, Urban Logistics is born to improve the efficiency in public facilities dealing with the organisation of supply networks, especially in urban freight transport networks. This paper quantitatively models supply chains in the vehicle routing problem with time windows, especially ...

  17. The influence of digital elevation model resolution on overland flow networks for modelling urban pluvial flooding.

    Science.gov (United States)

    Leitão, J P; Boonya-Aroonnet, S; Prodanović, D; Maksimović, C

    2009-01-01

    This paper presents the developments towards the next generation of overland flow modelling of urban pluvial flooding. Using a detailed analysis of the Digital Elevation Model (DEM) the developed GIS tools can automatically generate surface drainage networks which consist of temporary ponds (floodable areas) and flow paths and link them with the underground network through inlets. For different commercially-available Rainfall-Runoff simulation models, the tool will generate the overland flow network needed to model the surface runoff and pluvial flooding accurately. In this paper the emphasis is placed on a sensitivity analysis of ponds and preferential overland flow paths creation. Different DEMs for three areas were considered in order to compare the results obtained. The DEMs considered were generated using different acquisition techniques and hence represent terrain with varying levels of resolution and accuracy. The results show that DEMs can be used to generate surface flow networks reliably. As expected, the quality of the surface network generated is highly dependent on the quality and resolution of the DEMs and successful representation of buildings and streets.

  18. An entropy approach for evaluating the maximum information content achievable by an urban rainfall network

    Directory of Open Access Journals (Sweden)

    E. Ridolfi

    2011-07-01

    Full Text Available Hydrological models are the basis of operational flood-forecasting systems. The accuracy of these models is strongly dependent on the quality and quantity of the input information represented by rainfall height. Finer space-time rainfall resolution results in more accurate hazard forecasting. In this framework, an optimum raingauge network is essential in predicting flood events.

    This paper develops an entropy-based approach to evaluate the maximum information content achievable by a rainfall network for different sampling time intervals. The procedure is based on the determination of the coefficients of transferred and nontransferred information and on the relative isoinformation contours.

    The nontransferred information value achieved by the whole network is strictly dependent on the sampling time intervals considered. An empirical curve is defined, to assess the objective of the research: the nontransferred information value is plotted versus the associated sampling time on a semi-log scale. The curve has a linear trend.

    In this paper, the methodology is applied to the high-density raingauge network of the urban area of Rome.

  19. Personal networks and locus of control in large urban centers of Argentina

    Directory of Open Access Journals (Sweden)

    Pablo De Grande

    2013-12-01

    Full Text Available This study analyzes the relationship between locus of control and interpersonal relations structures in Argentina. After a representative sample (n = 1500 of households in seven major urban centers (>200,000 inhabitants, it examines the relationship between the externality of locus of control and different aspects of personal networks of each respondent. The results show that people having more relations experiment lower levels of externality of locus of control. Likewise, lower levels of externality are informed when personal ties outside the neighborhood are available, as well as ties high educational level. In this regard, significant associations are verified between control and personal relations structures.

  20. The Dallas-Fort Worth (DFW) Urban Radar Network: Enhancing Resilience in the Presence of Floods, Tornadoes, Hail and High Winds

    Science.gov (United States)

    Chandra*, Chandrasekar V.; the full DFW Team

    2015-04-01

    Currently, the National Weather Service (NWS) Next Generation Weather Radar (NEXRAD) provides observations updated every five-six minutes across the United States. However, at the maximum NEXRAD operating range of 230 km, the 0.5 degree radar beam (lowest tilt) height is about 5.4 km above ground level (AGL) because of the effect of Earth curvature. Consequently, much of the lower atmosphere (1-3 km AGL) cannot be observed by the NEXRAD. To overcome the fundamental coverage limitations of today's weather surveillance radars, and improve the spatial and temporal resolution issues, at urban scale, the National Science Foundation Engineering Research Center (NSF-ERC) for Collaborative Adaptive Sensing of the Atmosphere (CASA) has embarked the development of Dallas-Fort worth (DFW) urban remote sensing network to conduct high-resolution sensing in the lower atmosphere for a metropolitan environment, communicate high resolution observations and nowcasting of severe weather including flash floods, hail storms and high wind events. Being one of the largest inland metropolitan areas in the U.S., the DFW Metroplex is home to over 6.5 million people by 2012 according to the North Central Texas Council of Governments (NCTCOG). It experiences a wide range of natural weather hazards, including urban flash flood, high wind, tornado, and hail, etc. Successful monitoring of the rapid changing meteorological conditions in such a region is necessary for emergency management and decision making. Therefore, it is an ideal location to investigate the impacts of hazardous weather phenomena, to enhance resilience in an urban setting and demonstrate the CASA concept in a densely populated urban environment. The DFW radar network consists of 8 dual-polarization X-band weather radars and standard NEXRAD S-band radar, covering the greater DFW metropolitan region. This paper will present high resolution observation of tornado, urban flood, hail storm and damaging wind event all within the

  1. Supersampling and Network Reconstruction of Urban Mobility.

    Directory of Open Access Journals (Sweden)

    Oleguer Sagarra

    Full Text Available Understanding human mobility is of vital importance for urban planning, epidemiology, and many other fields that draw policies from the activities of humans in space. Despite the recent availability of large-scale data sets of GPS traces or mobile phone records capturing human mobility, typically only a subsample of the population of interest is represented, giving a possibly incomplete picture of the entire system under study. Methods to reliably extract mobility information from such reduced data and to assess their sampling biases are lacking. To that end, we analyzed a data set of millions of taxi movements in New York City. We first show that, once they are appropriately transformed, mobility patterns are highly stable over long time scales. Based on this observation, we develop a supersampling methodology to reliably extrapolate mobility records from a reduced sample based on an entropy maximization procedure, and we propose a number of network-based metrics to assess the accuracy of the predicted vehicle flows. Our approach provides a well founded way to exploit temporal patterns to save effort in recording mobility data, and opens the possibility to scale up data from limited records when information on the full system is required.

  2. Prioritizing conservation areas for coastal plant diversity under increasing urbanization.

    Science.gov (United States)

    Doxa, Aggeliki; Albert, Cécile Hélène; Leriche, Agathe; Saatkamp, Arne

    2017-10-01

    Coastal urban expansion will continue to drive further biodiversity losses, if conservation targets for coastal ecosystems are not defined and met. Prioritizing areas for future protected area networks is thus an urgent task in such urbanization-threatened ecosystems. Our aim is to quantify past and future losses of coastal vegetation priority areas due to urbanization and assess the effectiveness of the existing protected area network for conservation. We conduct a prioritization analysis, based on 82 coastal plants, including common and IUCN red list species, in a highly-urbanized but biotically diverse region, in South-Eastern France. We evaluate the role of protected areas, by taking into account both strict and multi-use areas. We assess the impact of past and future urbanization on high priority areas, by combining prioritization analyses and urbanization models. We show that half of the highly diverse areas have already been lost due to urbanization. Remaining top priority areas are also among the most exposed to future urban expansion. The effectiveness of the existing protected area (PA) network is only partial. While strict PAs coincide well with top priority areas, they only represent less than one third of priority areas. The effectiveness of multi-use PAs, such as the Natura 2000 network, also remains limited. Our approach highlights the impact of urbanization on plant conservation targets. By modelling urbanization, we manage to identify those areas where protection could be more efficient to limit further losses. We suggest to use our approach in the future to expand the PA network in order to achieve the 2020 Aichi biodiversity targets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Mobile wireless network for the urban environment

    Science.gov (United States)

    Budulas, Peter; Luu, Brian; Gopaul, Richard

    2005-05-01

    As the Army transforms into the Future Force, particular attention must be paid to operations in Complex and Urban Terrain. Our adversaries increasingly draw us into operations in the urban environment and one can presume that this trend will continue in future battles. In order to ensure that the United States Army maintains battlefield dominance, the Army Research Laboratory (ARL) is developing technology to equip our soldiers for the urban operations of the future. Sophisticated soldier borne systems will extend sensing to the individual soldier, and correspondingly, allow the soldier to establish an accurate picture of their surrounding environment utilizing information from local and remote assets. Robotic platforms will be an integral part of the future combat team. These platforms will augment the team with remote sensing modalities, task execution capabilities, and enhanced communication systems. To effectively utilize the products provided by each of these systems, collected data must be exchanged in real time to all affected entities. Therefore, the Army Research Laboratory is also developing the technology that will be required to support high bandwidth mobile communication in urban environments. This technology incorporates robotic systems that will allow connectivity in areas unreachable by traditional systems. This paper will address some of the issues of providing wireless connectivity in complex and urban terrain. It will further discuss approaches developed by the Army Research Laboratory to integrate communications capabilities into soldier and robotic systems and provide seamless connectivity between the elements of a combat team, and higher echelons.

  4. Comparative analysis of the performance of One-Way and Two-Way urban road networks

    Science.gov (United States)

    Gheorghe, Carmen

    2017-10-01

    The fact that the number of vehicles is increasing year after year represents a challenge in road traffic management because it is necessary to adjust the road traffic, in order to prevent any incidents, using mostly the same road infrastructure. At this moment one-way road network provides efficient traffic flow for vehicles but it is not ideal for pedestrians. Therefore, a proper solution must be found and applied when and where it is necessary. Replacing one-way road network with two-way road network may be a viable solution especially if in the area is high pedestrian traffic. The paper aims to highlight the influence of both, one-way and two-way urban road networks through an experimental research which was performed by using traffic data collected in the field. Each of the two scenarios analyzed were based on the same traffic data, the same geometrical conditions of the road (lane width, total road segment width, road slopes, total length of the road network) and also the same signaling conditions (signalised intersection or roundabout). The analysis which involves two-way scenario reveals changes in the performance parameters like delay average, stops average, delay stop average and vehicle speed average. Based on the values obtained, it was possible to perform a comparative analysis between the real, one-way, scenario and the theoretical, two-way, scenario.

  5. Urban transitions: on urban resilience and human-dominated ecosystems.

    Science.gov (United States)

    Ernstson, Henrik; van der Leeuw, Sander E; Redman, Charles L; Meffert, Douglas J; Davis, George; Alfsen, Christine; Elmqvist, Thomas

    2010-12-01

    Urbanization is a global multidimensional process paired with increasing uncertainty due to climate change, migration of people, and changes in the capacity to sustain ecosystem services. This article lays a foundation for discussing transitions in urban governance, which enable cities to navigate change, build capacity to withstand shocks, and use experimentation and innovation in face of uncertainty. Using the three concrete case cities--New Orleans, Cape Town, and Phoenix--the article analyzes thresholds and cross-scale interactions, and expands the scale at which urban resilience has been discussed by integrating the idea from geography that cities form part of "system of cities" (i.e., they cannot be seen as single entities). Based on this, the article argues that urban governance need to harness social networks of urban innovation to sustain ecosystem services, while nurturing discourses that situate the city as part of regional ecosystems. The article broadens the discussion on urban resilience while challenging resilience theory when addressing human-dominated ecosystems. Practical examples of harnessing urban innovation are presented, paired with an agenda for research and policy.

  6. A statistical intercomparison between 'urban' and 'rural' precipitation chemistry data from Greater Manchester and the two nearby secondary national network sites in the United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.S.; Longhurst, J.W.S. (Manchester Polytechnic, Manchester (United Kingdom). Acid Rain Information Centre, Dept. of Environmental and Graphical Studies)

    1992-11-01

    Precipitation chemistry data from a dense urban monitoring network in Greater Manchester, northwest England, were compared with interpolated values from the U.K. secondary national acid deposition monitoring network for the year 1988. Differences were found to be small. However, when data from individual sites from the Greater Manchester network were compared with data from the two nearest secondary national network sites, significant differences were found using simple and complex statistical analyses. Precipitation chemistry at rural sites could be similar to that at urban sites, but the sources of some ions were thought to be different. The synoptic-scale gradients of precipitation chemistry, as shown by the secondary national network, also accounted for some of the differences. 34 refs., 7 figs., 8 tabs.

  7. Effects of Using High-Density Rain Gauge Networks and Weather Radar Data on Urban Hydrological Analyses

    Directory of Open Access Journals (Sweden)

    Seong-Sim Yoon

    2017-11-01

    Full Text Available Flood prediction is difficult in urban areas because only sparse gauge data and radar data of low accuracy are usually used to analyze flooding and inundation. Sub-basins of urban areas are extremely small, so rainfall data of high spatial resolution are required for analyzing complex drainage systems with high spatial variability. This study aimed to produce three types of quantitative precipitation estimation (QPE products using rainfall data that was derived from 190 gauges, including the new high-density rain-gauge network operated by the SK Planet company, and the automated weather stations of the Korea Meteorological Administration, along with weather radar data. This study also simulated urban runoff for the Gangnam District of Seoul, South Korea, using the obtained QPE products to evaluate hydraulic and hydrologic impacts according to three rainfall fields. The accuracy of this approach was assessed in terms of the amount and spatial distribution of rainfall in an urban area. The QPE products provided highly accurate results and simulations of peak runoff and overflow phenomena. They also accurately described the spatial variability of the rainfall fields. Overall, the integration of high-density gauge data with radar data proved beneficial for quantitative rainfall estimation.

  8. ZONAL IMPACT ANALYSIS OF A STRATEGIC PLANNING APPROACH FOR LAND DEVELOPMENT CONTROLS

    Directory of Open Access Journals (Sweden)

    Karin LIMAPORNWANITCH

    2004-01-01

    Full Text Available Due to rapid urban developments in developing cities, the integration of land-use and transportation planning is very necessary. However, up-to-date land-use and transportation interaction planning is still difficult, because of rapid urbanization and complex relationships. The lack of human resources, budget, and necessary data are some of the hindrances. The planners in Bangkok have tried to utilize Traffic Impact Assessment (TIA in harmonizing land developments and transportation improvements, but without a complete land-use comprehensive plan, the TIA cannot effectively manage urbanization. This paper intends to propose a Zonal Impact Analysis (ZIA framework as a strategic planning tool to balance travel demands of land developments and performance of transportation systems over urban areas. First, the land-use planning situation in Bangkok is explained, afterwards the framework is described. The framework is applied into Bangkapi areas as a case study. Both single and simultaneous development cases are considered. It was found that more comprehensive development alternatives were established. The most suitable zone for a single project is Zone 179, as the advantages of location in the center of radial networks, so full accessibility can be provided. Without any network improvements in Zone 179, the simultaneous developments should be implemented in Zone 168 and 173, as high capacities of the expressway are available. The results give a better understanding on the characteristics of land-use and transportation planning in Bangkapi. Finally, it was emphasized that the ZIA framework is a strategic planning alternative to increase the capabilities of growth management for sustainable developments.

  9. The rational operation of the urban transport line network by minimisation of the needed vehicles

    OpenAIRE

    Daněk, Jan; Plevný, Miroslav; Teichmann, Dušan

    2010-01-01

    The construction of the urban transport line network is one of the fundamental problems in the traffic practice. Efficient functioning of the public mass transportation supported from the public sources in the towns is more urgent at present, when the individual automobile traffic leads to congestions in central parts of the cities. The demand to increase the culture of travelling in the public mass transportation requires, however, substantial costs. Therefore it is necessary to solve the ba...

  10. Evaluating the impact and risk of pluvial flash flood on intra-urban road network: A case study in the city center of Shanghai, China

    Science.gov (United States)

    Yin, Jie; Yu, Dapeng; Yin, Zhane; Liu, Min; He, Qing

    2016-06-01

    Urban pluvial flood are attracting growing public concern due to rising intense precipitation and increasing consequences. Accurate risk assessment is critical to an efficient urban pluvial flood management, particularly in transportation sector. This paper describes an integrated methodology, which initially makes use of high resolution 2D inundation modeling and flood depth-dependent measure to evaluate the potential impact and risk of pluvial flash flood on road network in the city center of Shanghai, China. Intensity-Duration-Frequency relationships of Shanghai rainstorm and Chicago Design Storm are combined to generate ensemble rainfall scenarios. A hydrodynamic model (FloodMap-HydroInundation2D) is used to simulate overland flow and flood inundation for each scenario. Furthermore, road impact and risk assessment are respectively conducted by a new proposed algorithm and proxy. Results suggest that the flood response is a function of spatio-temporal distribution of precipitation and local characteristics (i.e. drainage and topography), and pluvial flash flood is found to lead to proportionate but nonlinear impact on intra-urban road inundation risk. The approach tested here would provide more detailed flood information for smart management of urban street network and may be applied to other big cities where road flood risk is evolving in the context of climate change and urbanization.

  11. AVIRIS data and neural networks applied to an urban ecosystem

    Science.gov (United States)

    Ridd, Merrill K.; Ritter, Niles D.; Bryant, Nevin A.; Green, Robert O.

    1992-01-01

    Urbanization is expanding on every continent. Although urban/industrial areas occupy a small percentage of the total landscape of the earth, their influence extends far beyond their borders, affecting terrestrial, aquatic, and atmospheric systems globally. Yet little has been done to characterize urban ecosystems of their linkages to other systems horizontally or vertically. With remote sensing we now have the tools to characterize, monitor, and model urban landscapes world-wide. However, the remote sensing performed on cities so far has concentrated on land-use patterns as distinct from land-cover or composition. The popular Anderson system is entirely land-use oriented in urban areas. This paper begins with the premise that characterizing the biophysical composition of urban environments is fundamental to understanding urban/industrial ecosystems, and, in turn, supports the modeling of other systems interfacing with urban systems. Further, it is contended that remote sensing is a tool poised to provide the biophysical composition data to characterize urban landscapes.

  12. The impact of cost and network topology on urban mobility: a study of public bicycle usage in 2 U.S. cities.

    Science.gov (United States)

    Jurdak, Raja

    2013-01-01

    Understanding the drivers of urban mobility is vital for epidemiology, urban planning, and communication networks. Human movements have so far been studied by observing people's positions in a given space and time, though most recent models only implicitly account for expected costs and returns for movements. This paper explores the explicit impact of cost and network topology on mobility dynamics, using data from 2 city-wide public bicycle share systems in the USA. User mobility is characterized through the distribution of trip durations, while network topology is characterized through the pairwise distances between stations and the popularity of stations and routes. Despite significant differences in station density and physical layout between the 2 cities, trip durations follow remarkably similar distributions that exhibit cost sensitive trends around pricing point boundaries, particularly with long-term users of the system. Based on the results, recommendations for dynamic pricing and incentive schemes are provided to positively influence mobility patterns and guide improved planning and management of public bicycle systems to increase uptake.

  13. "You Have to Hold Your Own": Investigating the Social Networks of a Diverse Group of Disenfranchised Urban Male Youth

    Science.gov (United States)

    Esposito, Jennifer; Happel, Alison

    2015-01-01

    This ethnographic case study investigates social networks and forms of social capital accessed by a group of five urban male youth (ages 15-19), from diverse racial backgrounds, who were disenfranchised economically. We refer to the youth as "disenfranchised" because they were disconnected from forms of institutional support, especially…

  14. Ecological relationship analysis of the urban metabolic system of Beijing, China

    International Nuclear Information System (INIS)

    Li Shengsheng; Zhang Yan; Yang Zhifeng; Liu Hong; Zhang Jinyun

    2012-01-01

    Cities can be modelled as giant organisms, with their own metabolic processes, and can therefore be studied using the same tools used for biological metabolic systems. The complicated distribution of compartments within these systems and the functional relationships among them define the system's network structure. Taking Beijing as an example, we divided the city's internal system into metabolic compartments, then used ecological network analysis to calculate a comprehensive utility matrix for the flows between compartments within Beijing's metabolic system from 1998 to 2007 and to identify the corresponding functional relationships among the system's compartments. Our results show how ecological network analysis, utility analysis, and relationship analysis can be used to discover the implied ecological relationships within a metabolic system, thereby providing insights into the system's internal metabolic processes. Such analyses provide scientific support for urban ecological management. - Highlights: ► Urban metabolic processes can be analyzed by treating cities as superorganisms. ► We developed an ecological network model for an urban system. ► We studied the system's network relationships using ecological network analysis. ► We developed indices for judging the system's synergism and degree of stability. - Using Beijing as an example of an urban superorganism, we used ecological network analysis to describe the ecological relationships among the urban metabolic system's compartments.

  15. Flying Real-Time Network to Coordinate Disaster Relief Activities in Urban Areas

    Directory of Open Access Journals (Sweden)

    Matias Micheletto

    2018-05-01

    Full Text Available While there have been important advances within wireless communication technology, the provision of communication support during disaster relief activities remains an open issue. The literature in disaster research reports several major restrictions to conducting first response activities in urban areas, given the limitations of telephone networks and radio systems to provide digital communication in the field. In search-and-rescue operations, the communication requirements are increased, since the first responders need to rely on real-time and reliable communication to perform their activities and coordinate their efforts with other teams. Therefore, these limitations open the door to improvisation during disaster relief efforts. In this paper, we argue that flying ad-hoc networks can provide the communication support needed in these scenarios, and propose a new solution towards that goal. The proposal involves the use of flying witness units, implemented using drones, that act as communication gateways between first responders working at different locations of the affected area. The proposal is named the Flying Real-Time Network, and its feasibility to provide communication in a disaster scenario is shown by presenting both a real-time schedulability analysis of message delivery, as well as simulations of the communication support in a physical scenario inspired by a real incident. The obtained results were highly positive and consistent, therefore this proposal represents a step forward towards the solution of this open issue.

  16. Nineteenth-century transnational urban history

    DEFF Research Database (Denmark)

    Jørgensen, Claus Møller

    2017-01-01

    The aim of this article is to take stock of nineteenth-century transnational urban history. After a short introduction to transnational history, general urban histories are analysed with respect to the ways in which transnational perspectives are incorporated into the narratives. Specific...... contributions to urban history in a transnational perspective are analysed. Approaches to urban planning history that focus on transnational linkages and international organization are discussed. Approaches to urban history within enlarged geographical scales that go beyond the nation-state framework......, with a particular focus on cities as nodes in translocal networks, are analysed. The article concludes with a critical discussion of nineteenth-century transnational urban history....

  17. [Heat vulnerability assessment in Jinan city: a comparison between residents living in urban centers and urban-fringe areas].

    Science.gov (United States)

    Wan, Fangjun; Xin, Zheng; Zhou, Lin; Bai, Li; Wang, Yongming; Gu, Shaohua; Liu, Shouqin; Li, Mengmeng; Sang, Shaowei; Zhang, Ji; Liu, Qiyong

    2014-06-01

    To find out the differences in regional characteristics of heat vulnerability between people living in urban centers and urban-fringe areas of Jinan city so as to provide basis for the development of adaptation measures to heat. A cross-sectional survey on heat vulnerability was conducted in urban center and urban-fringe areas of Jinan city, using a self-designed questionnaire among 801 residents at the age of 16 years or older in August 2013. Data of 23 indicators related to heat vulnerability were collected and aggregated to 7 dimensions:health and medical insurance, social networks, heat perception and adaptive behavior, economic status, resources, living environment and working environment. An index score was calculated using a balanced weighted average approach for each dimension, ranging from 0 to 1, with the closer to 1 as greater vulnerability. The scores on heat perception and adaptive behavior, economic status, resources and working environment dimensions for urban-fringe areas were 0.42,0.63,0.55 and 0.62, statistically significantly higher than the urban center area of 0.41,0.51,0.26 and 0.41. Scores of living environment, social networks and health/medical insurance dimensions for urban center area were 0.57,0.49 and 0.31, which were all higher than the urban-fringe areas of 0.50,0.46 and 0.25, with differences statistically significant. Residents living in the urban center might be more vulnerable to heat in terms of living environment, health/medical insurance and social networks while residents living in the urban-fringe areas might more be vulnerable in terms of heat perception and adaptive behavior, economic status, life resources and working environment. These facts indicated that heat vulnerability among residents could be quite different, even at a fine geographic sale. We would thus suggest that intervention strategies on protecting people from heat, should be more targeted.

  18. Examining The Evolution Of The Khuzestan Urban Population Using The Urban Primacy Indexes

    Directory of Open Access Journals (Sweden)

    Mokhtar Karami

    2017-12-01

    Full Text Available Examining the status of a city in the surrounding metropolitan area network not only helpful for Specialists to understand the ups and downs of city life and surrounding it but also can set the groundwork for hierarchical relationships settlements and planners for discipline the urban network is studied. Research to study the evolution of the urban population in Khuzestan province was conducted during the statistical period 1957-2012. The method is a descriptive and analytical study. To collect the data in addition the study of literature the Facts Sheet the statistical yearbooks and census of population and housing censuses in all courses has been used. Then to enter data and analysis it the Excel and Minitab software was used. Models used in this study are Ginsberg index Urban Primacy Index Two City Index Four City Index Mehtas Four City Index Moomav and Alwosabi. The results show that is balance between the parameters of the Urban Primacy Indexes in Khuzestan province since 1957 to 1977. The process of balancing continue and is destroy until the beginning of the Imposed war and the depletion of the population of cities and in 1987 the Urban Primacy Index reached its highest level and due to the problems of the war in Ahvaz it earns the highest the Urban Primacy Index. Since 1987 the Urban Primacy Index reduced and their balancing process continues until 2012 that this balancing process due to natural population growth since after 1997.

  19. Tracking artificial sweeteners and pharmaceuticals introduced into urban groundwater by leaking sewer networks.

    Science.gov (United States)

    Wolf, Leif; Zwiener, Christian; Zemann, Moritz

    2012-07-15

    There is little quantitative information on the temporal trends of pharmaceuticals and other emerging compounds, including artificial sweeteners, in urban groundwater and their suitability as tracers to inform urban water management. In this study, pharmaceuticals and artificial sweeteners were monitored over 6 years in a shallow urban groundwater body along with a range of conventional sewage tracers in a network of observation wells that were specifically constructed to assess sewer leakage. Out of the 71 substances screened, 24 were detected at above the analytical detection limit. The most frequent compounds were the iodinated X-ray contrast medium amidotrizoic acid (35.3%), the anticonvulsant carbamazepine (33.3%) and the artificial sweetener acesulfame (27.5%), while all other substances occurred in less than 10% of the screened wells. The results from the group of specifically constructed focus wells within 10 m of defective sewers confirmed sewer leaks as being a major entrance pathway into the groundwater. The spatial distribution of pharmaceuticals and artificial sweeteners corresponds well with predictions by pipeline leakage models, which operate on optical sewer condition monitoring data and hydraulic information. Correlations between the concentrations of carbamazepine, iodinated X-ray contrast media and artificial sweeteners were weak to non-existent. Peak concentrations of up to 4130 ng/l of amidotrizoic acid were found in the groundwater downstream of the local hospital. The analysis of 168 samples for amidotrizoic acid, taken at 5 different occasions, did not show significant temporal trends for the years 2002-2008, despite changed recommendations in the medical usage of amidotrizoic acid. The detailed results show that the current mass balance approaches for urban groundwater bodies must be adapted to reflect the spatially distributed leaks and the variable wastewater composition in addition to the lateral and horizontal groundwater fluxes. Crown

  20. Are autonomous cities our urban future?

    Science.gov (United States)

    Norman, Barbara

    2018-05-29

    Cities are rapidly expanding in size, wealth and power, with some now larger than nation states. Smart city solutions and strong global urban networks are developing to manage massive urban growth. However, cities exist within a wider system and it may take more than technological advances, innovation and city autonomy to develop a sustainable urban future.

  1. Development of flood probability charts for urban drainage network in coastal areas through a simplified joint assessment approach

    Directory of Open Access Journals (Sweden)

    R. Archetti

    2011-10-01

    Full Text Available The operating conditions of urban drainage networks during storm events depend on the hydraulic conveying capacity of conduits and also on downstream boundary conditions. This is particularly true in coastal areas where the level of the receiving water body is directly or indirectly affected by tidal or wave effects. In such cases, not just different rainfall conditions (varying intensity and duration, but also different sea-levels and their effects on the network operation should be considered. This paper aims to study the behaviour of a seaside town storm sewer network, estimating the threshold condition for flooding and proposing a simplified method to assess the urban flooding severity as a function of climate variables. The case study is a portion of the drainage system of Rimini (Italy, implemented and numerically modelled by means of InfoWorks CS code. The hydraulic simulation of the sewerage system identified the percentage of nodes of the drainage system where flooding is expected to occur. Combining these percentages with both climate variables' values has lead to the definition of charts representing the combined degree of risk "rainfall-sea level" for the drainage system under investigation. A final comparison between such charts and the results obtained from a one-year rainfall-sea level time series has demonstrated the reliability of the analysis.

  2. An environmental pressure index proposal for urban development planning based on the analytic network process

    International Nuclear Information System (INIS)

    Gomez-Navarro, Tomas; Garcia-Melon, Monica; Acuna-Dutra, Silvia; Diaz-Martin, Diego

    2009-01-01

    This paper introduces a new approach to prioritize urban planning projects according to their environmental pressure in an efficient and reliable way. It is based on the combination of three procedures: (i) the use of environmental pressure indicators, (ii) the aggregation of the indicators in an Environmental Pressure Index by means of the Analytic Network Process method (ANP) and (iii) the interpretation of the information obtained from the experts during the decision-making process. The method has been applied to a proposal for urban development of La Carlota airport in Caracas (Venezuela). There are three options which are currently under evaluation. They include a Health Club, a Residential Area and a Theme Park. After a selection process the experts chose the following environmental pressure indicators as ANP criteria for the project life cycle: used land area, population density, energy consumption, water consumption and waste generation. By using goal-oriented questionnaires designed by the authors, the experts determined the importance of the criteria, the relationships among criteria, and the relationships between the criteria and the urban development alternatives. The resulting data showed that water consumption is the most important environmental pressure factor, and the Theme Park project is by far the urban development alternative which exerts the least environmental pressure on the area. The participating experts coincided in appreciating the technique proposed in this paper is useful and, for ranking ordering these alternatives, an improvement from traditional techniques such as environmental impact studies, life-cycle analysis, etc.

  3. Urban wet deposition nitrate: a comparison to non-urban deposition

    International Nuclear Information System (INIS)

    Schultz, J.A.M.

    1994-01-01

    The concentration of nitrate in both wet and dry deposition has both increased historically and currently, and recently parallels emissions in NO x . Since NO x is produced in amounts comparable to SO 2 , it is an important contributor to acid deposition, and is produced in higher amounts in urban areas due to concentrated sources. Prior to to this study, national acid deposition monitoring networks in the United States have been and remain established in non-urban areas. This research study consisted of a comparison of precipitation sampling and analysis of wet deposition nitrate and pH for each deposition event in each of two urban sites over a 15 mo period. Also, a comparison of urban data and data generated at a nearby non-urban NADP site was made by examination of both monthly and seasonal data. This research suggests that national monitoring programs should consider inclusion of urban and non-urban monitoring sites in order to achieve a more representative regional assessment. 24 refs., 2 figs., 2 tabs

  4. Climate change impacts on urban wildfire and flooding policy in Idaho: a comparative policy network perspective

    Science.gov (United States)

    Lindquist, E.; Pierce, J. L.

    2013-12-01

    Numerous frameworks and models exist for understanding the dynamics of the public policy process. A policy network approach considers how and why stakeholders and interests pay attention to and engage in policy problems, such as flood control or developing resilient and fire resistant landscapes. Variables considered in this approach include what the relationships are between these stakeholders, how they influence the process and outcomes, communication patterns within and between policy networks, and how networks change as a result of new information, science, or public interest and involvement with the problem. This approach is useful in understanding the creation of natural hazards policy as new information or situations, such as projected climate change impacts, influence and disrupt the policy process and networks. Two significant natural hazard policy networks exist in the semi-arid Treasure Valley region of Southwest Idaho, which includes the capitol city of Boise and the surrounding metropolitan area. Boise is situated along the Boise River and adjacent to steep foothills; this physiographic setting makes Boise vulnerable to both wildfires at the wildland-urban interface (WUI) and flooding. Both of these natural hazards have devastated the community in the past and floods and fires are projected to occur with more frequency in the future as a result of projected climate change impacts in the region. While both hazards are fairly well defined problems, there are stark differences lending themselves to comparisons across their respective networks. The WUI wildfire network is large and well developed, includes stakeholders from all levels of government, the private sector and property owner organizations, has well defined objectives, and conducts promotional and educational activities as part of its interaction with the public in order to increase awareness and garner support for its policies. The flood control policy network, however, is less defined

  5. Optimal urban networks via mass transportation

    CERN Document Server

    Buttazzo, Giuseppe; Stepanov, Eugene; Solimini, Sergio

    2009-01-01

    Recently much attention has been devoted to the optimization of transportation networks in a given geographic area. One assumes the distributions of population and of services/workplaces (i.e. the network's sources and sinks) are known, as well as the costs of movement with/without the network, and the cost of constructing/maintaining it. Both the long-term optimization and the short-term, "who goes where" optimization are considered. These models can also be adapted for the optimization of other types of networks, such as telecommunications, pipeline or drainage networks. In the monograph we study the most general problem settings, namely, when neither the shape nor even the topology of the network to be constructed is known a priori.

  6. Tree agency and urban forest governance

    DEFF Research Database (Denmark)

    Konijnendijk, Cecil Cornelis

    2016-01-01

    governance also involving businesses and civic society. However, governance theory usually does not consider the role of non-human agency, which can be considered problematic due to, for example, the important role of urban trees in place making. The purpose of this paper is to provide further insight...... into the importance of considering tree agency in governance. Design/methodology/approach – Taking an environmental governance and actor network theory perspective, the paper presents a critical view of current urban forest governance, extending the perspective to include not only a wide range of human actors......, but also trees as important non-human actors. Findings – Urban forest governance has become more complex and involves a greater range of actors and actor networks. However, the agency of trees in urban forest governance is seldom well developed. Trees, in close association with local residents, create...

  7. Decades of urban growth and development on the Asian megadeltas

    Science.gov (United States)

    Small, Christopher; Sousa, Daniel; Yetman, Gregory; Elvidge, Christopher; MacManus, Kytt

    2018-06-01

    The current and ongoing expansion of urban areas worldwide represents the largest mass migration in human history. It is well known that the world's coastal zones are associated with large and growing concentrations of population, urban development and economic activity. Among coastal environments, deltas have long been recognized for both benefits and hazards. This is particularly true on the Asian megadeltas, where the majority of the world's deltaic populations reside. Current trends in urban migration, combined with demographic momentum suggest that the already large populations on the Asian megadeltas will continue to grow. In this study, we combine recently released gridded population density (circa 2010) with a newly developed night light change product (1992 to 2012) and a digital elevation model to quantify the spatial distribution of population and development on the nine Asian megadeltas. Bivariate distributions of population as functions of elevation and coastal proximity quantify potential exposure of deltaic populations to flood and coastal hazards. Comparison of these distributions for the Asian megadeltas show very different patterns of habitation with peak population elevations ranging from 2 to 11 m above sea level over a wide range of coastal proximities. Over all nine megadeltas, over 174 million people reside below a peak population elevation of 7 m. Changes in the spatial extent of anthropogenic night light from 1992 to 2012 show widely varying extents and changes of lighted urban development. All of the deltas except the Indus show the greatest increases in night light brightness occurring at elevations <10 m. At global and continental scales, growth of settlements of all sizes takes the form of evolving spatial networks of development. Spatial networks of lighted urban development in Asia show power law scaling properties consistent with other continents, but much higher rates of growth. The three largest networks of development in China all

  8. Roads Belong in the Urban Landscape

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2013-01-01

    Roads are often associated with a fragmentation or splintering of landscapes and their natural connectivity; particularly in relation to ‘green infrastructure’ they are often considered problematic elements that rupture and barricade. Conversely, as part of larger networks, roads can be considered...... important elements in the creation of new, ‘green infrastructures’ that can qualify urban landscapes in terms of improving their overall porosity and connectivity. This argument will be unfolded and substantiated in this article through theoretical reflections which conceptually re-locate road networks...... in the urban landscape, supported by relevant reference projects that illustrate the potential of road networks as a platform for ‘green infrastructure’....

  9. Urban Knowledge Arena

    Directory of Open Access Journals (Sweden)

    Karel Schmeidler

    2008-01-01

    Full Text Available COST Action C20 – Urban Knowledge Arena is research programme supported by European Co-operation in the Field of Scientific and Technical Research. It is co-ordinated by COST Office and European Science Foundation. The main objective of this Action is to explore and develop a European Arena for cross boundary, integrated knowledge and Know-how on complex urban problems, which is termed Urban Knowledge Arena. The COST Domain Transport and Urban Development aims at fostering international research networking activities of scientist and experts dealing with transport systems and infrastructures, spatial planning, urban land use and development, urban design, architecture and design and civil engineering issues. The focus is on multi and interdisciplinary approaches and the aim is to cover both basic and applied research activities and their changeovers that are relevant to policy and decision making processes. A significant concern is devoted to activities exploring new research needs and developments.

  10. Urban economies and occupation space: can they get "there" from "here"?

    Science.gov (United States)

    Muneepeerakul, Rachata; Lobo, José; Shutters, Shade T; Goméz-Liévano, Andrés; Qubbaj, Murad R

    2013-01-01

    Much of the socioeconomic life in the United States occurs in its urban areas. While an urban economy is defined to a large extent by its network of occupational specializations, an examination of this important network is absent from the considerable body of work on the determinants of urban economic performance. Here we develop a structure-based analysis addressing how the network of interdependencies among occupational specializations affects the ease with which urban economies can transform themselves. While most occupational specializations exhibit positive relationships between one another, many exhibit negative ones, and the balance between the two partially explains the productivity of an urban economy. The current set of occupational specializations of an urban economy and its location in the occupation space constrain its future development paths. Important tradeoffs exist between different alternatives for altering an occupational specialization pattern, both at a single occupation and an entire occupational portfolio levels.

  11. Spatial correlation analysis of urban traffic state under a perspective of community detection

    Science.gov (United States)

    Yang, Yanfang; Cao, Jiandong; Qin, Yong; Jia, Limin; Dong, Honghui; Zhang, Aomuhan

    2018-05-01

    Understanding the spatial correlation of urban traffic state is essential for identifying the evolution patterns of urban traffic state. However, the distribution of traffic state always has characteristics of large spatial span and heterogeneity. This paper adapts the concept of community detection to the correlation network of urban traffic state and proposes a new perspective to identify the spatial correlation patterns of traffic state. In the proposed urban traffic network, the nodes represent road segments, and an edge between a pair of nodes is added depending on the result of significance test for the corresponding correlation of traffic state. Further, the process of community detection in the urban traffic network (named GWPA-K-means) is applied to analyze the spatial dependency of traffic state. The proposed method extends the traditional K-means algorithm in two steps: (i) redefines the initial cluster centers by two properties of nodes (the GWPA value and the minimum shortest path length); (ii) utilizes the weight signal propagation process to transfer the topological information of the urban traffic network into a node similarity matrix. Finally, numerical experiments are conducted on a simple network and a real urban road network in Beijing. The results show that GWPA-K-means algorithm is valid in spatial correlation analysis of traffic state. The network science and community structure analysis perform well in describing the spatial heterogeneity of traffic state on a large spatial scale.

  12. Spatial variation and sources of polycyclic aromatic hydrocarbons influenced by intensive land use in an urbanized river network of East China.

    Science.gov (United States)

    Bi, Chunjuan; Wang, Xueping; Jia, Jinpu; Chen, Zhenlou

    2018-06-15

    The concentrations and distribution of polycyclic aromatic hydrocarbons (PAHs) in urbanized river networks are strongly influenced by intensive land use, industrial activities and population density. The spatial variations and their influencing factors of 16 priority PAHs were investigated in surface water, suspended particulate matter (SPM) and sediments among areas under different intensive land uses (industrial areas, agricultural areas, inner city, suburban towns and island areas) in the Shanghai river network, East China. Source apportionment was carried out using isomer ratios of PAHs and Positive Matrix Factorization (PMF). Total concentrations of 16 PAHs ranged from 105.2 to 400.5 ng/L, 108.1 to 1058.8 ng/L and 104.4 to 19,480.0 ng/g in water, SPM and sediments, respectively. The concentrations of PAHs in SPM and sediments varied significantly among areas (p natural gas combustion in water and SPM, and vehicular emissions in sediments. Vehicular emissions were the strongest contributors in SPM and sediments of the inner city, indicating the strong influence of vehicular transportation to PAHs pollution in the urbanized river network. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Quantifying the robustness of metro networks

    NARCIS (Netherlands)

    Wang, X.; Koç, Y.; Derrible, S.; Nasir Ahmad, Sk.; Kooij, R.E.

    2015-01-01

    Metros (heavy rail transit systems) are integral parts of urban transportation systems. Failures in their operations can have serious impacts on urban mobility, and measuring their robustness is therefore critical. Moreover, as physical networks, metros can be viewed as network topological entities,

  14. Interfacial modulation of urban affect

    DEFF Research Database (Denmark)

    Samson, Kristine

    Urban culture can increasingly be understood as interface culture (Munster) in which urban design, cultural institutions and architecture increasingly operate as affective interfaces distributing and mediating human perception, consumption and social encounters. As noted by Amin and Thrift (2002......, Massey 2006), they also exclude in depth social and human interaction. Through analysis of three examples of urban affective interfaces (The High Line in New York, Superkilen in Copenhagen and Stålsat By, Frederiksværk, the paper examines how affective urban interfaces modulate and mediate urban...... environments as bodily and sensorial experiences. It asks what is mediated through the interface – whether the. It also asks, what is excluded when urban environments become affective interfaces in the global networked city. Whereas urban interface collect and distribute the bodily and sensible in relational...

  15. E – urban systems

    Directory of Open Access Journals (Sweden)

    Franc J. Zakrajšek

    2000-01-01

    Full Text Available Information and tele-communication technology are increasingly affecting life and employment. According to predictions, more than 80% of all business operations will be carried out electronically through so called e-business. Recently even in Slovenia discussions have begun on “e-government”. Despite desired or undesired control, virtual networks are changing urban systems into e-urban systems. The extent of benefits to the public also depend on planners. The article presents concepts with the signature “e” to describe urban systems, day-to-day life, real-estate and simulation.

  16. A methodology for urban flood resilience assessment

    Science.gov (United States)

    Lhomme, Serge; Serre, Damien; Diab, Youssef; Laganier, Richard

    2010-05-01

    In Europe, river floods have been increasing in frequency and severity [Szöllösi-Nagy and Zevenbergen, 2005]. Moreover, climate change is expected to exacerbate the frequency and intensity of hydro meteorological disaster [IPCC, 2007]. Despite efforts made to maintain the flood defense assets, we often observe levee failures leading to finally increase flood risk in protected area. Furthermore, flood forecasting models, although benefiting continuous improvements, remain partly inaccurate due to uncertainties arising all along data calculation processes. In the same time, the year 2007 marks a turning point in history: half of the world population now lives in cities (UN-Habitat, 2007). Moreover, the total urban population is expected to double from two to four billion over the next 30 to 35 years (United Nations, 2006). This growing rate is equivalent to the creation of a new city of one million inhabitants every week, and this during the next four decades [Flood resilience Group]. So, this quick urban development coupled with technical failures and climate change have increased flood risk and corresponding challenges to urban flood risk management [Ashley et al., 2007], [Nie et al., 2009]. These circumstances oblige to manage flood risk by integrating new concepts like urban resilience. In recent years, resilience has become a central concept for risk management. This concept has emerged because a more resilient system is less vulnerable to risk and, therefore, more sustainable [Serre et al., 2010]. But urban flood resilience is a concept that has not yet been directly assessed. Therefore, when decision makers decide to use the resilience concept to manage urban flood, they have no tool to help them. That is why this paper proposes a methodology to assess urban flood resilience in order to make this concept operational. Networks affect the well-being of the people and the smooth functioning of services and, more generally, of economical activities. Yet

  17. Urban economies and occupation space: can they get "there" from "here"?

    Directory of Open Access Journals (Sweden)

    Rachata Muneepeerakul

    Full Text Available Much of the socioeconomic life in the United States occurs in its urban areas. While an urban economy is defined to a large extent by its network of occupational specializations, an examination of this important network is absent from the considerable body of work on the determinants of urban economic performance. Here we develop a structure-based analysis addressing how the network of interdependencies among occupational specializations affects the ease with which urban economies can transform themselves. While most occupational specializations exhibit positive relationships between one another, many exhibit negative ones, and the balance between the two partially explains the productivity of an urban economy. The current set of occupational specializations of an urban economy and its location in the occupation space constrain its future development paths. Important tradeoffs exist between different alternatives for altering an occupational specialization pattern, both at a single occupation and an entire occupational portfolio levels.

  18. Floyd-A∗ Algorithm Solving the Least-Time Itinerary Planning Problem in Urban Scheduled Public Transport Network

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2014-01-01

    Full Text Available We consider an ad hoc Floyd-A∗ algorithm to determine the a priori least-time itinerary from an origin to a destination given an initial time in an urban scheduled public transport (USPT network. The network is bimodal (i.e., USPT lines and walking and time dependent. The modified USPT network model results in more reasonable itinerary results. An itinerary is connected through a sequence of time-label arcs. The proposed Floyd-A∗ algorithm is composed of two procedures designated as Itinerary Finder and Cost Estimator. The A∗-based Itinerary Finder determines the time-dependent, least-time itinerary in real time, aided by the heuristic information precomputed by the Floyd-based Cost Estimator, where a strategy is formed to preestimate the time-dependent arc travel time as an associated static lower bound. The Floyd-A∗ algorithm is proven to guarantee optimality in theory and, demonstrated through a real-world example in Shenyang City USPT network to be more efficient than previous procedures. The computational experiments also reveal the time-dependent nature of the least-time itinerary. In the premise that lines run punctually, “just boarding” and “just missing” cases are identified.

  19. Towards an Urbanism of Entanglement

    DEFF Research Database (Denmark)

    Tietjen, Anne

    2009-01-01

    perspectives on polarised urban development in Denmark. Starting from a dynamic relational concept of the city, East and North Jutland can be perceived as different regional situations within a potentially unlimited networked urban landscape. At the same time, the enhancement of active site relationships comes...... a radical urbanisation process that challenges the domain and the procedures of urban design. Key words are regionalisation, dissolution of the city/countryside dichotomy, and regional, national and transnational networks. At the same time, the discourse on polarisation marks a shift from an ideal...... of spatial equality throughout Denmark to an ideal of balanced development. This shift dates back to the 1980s but has gained new topicality in light of increased spatial inequality. Current Danish spatial policy targets the two large city regions around Copenhagen and in East Jutland as the engines...

  20. Linking urbanization to the Biological Condition Gradient (BCG) for stream ecosystems in the Northeastern United States using a Bayesian network approach

    Science.gov (United States)

    Kashuba, Roxolana; McMahon, Gerard; Cuffney, Thomas F.; Qian, Song; Reckhow, Kenneth; Gerritsen, Jeroen; Davies, Susan

    2012-01-01

    Urban development alters important physical, chemical, and biological processes that define urban stream ecosystems. An approach was developed for quantifying the effects of these processes on aquatic biota, and then linking those effects to endpoints that can be used for environmental management. These complex, interacting systems are challenging to model from a scientific standpoint. A desirable model clearly shows the system, simulates the interactions, and ultimately predicts results of management actions. Traditional regression techniques that calculate empirical relations between pairs of environmental factors do not capture the interconnected web of multiple stressors, but urban development effects are not yet understood at the detailed scales required to make mechanistic modeling approaches feasible. Therefore, in contrast to a fully deterministic or fully statistical modeling approach, a Bayesian network model provides a hybrid approach that can be used to represent known general associations between variables while acknowledging uncertainty in predicted outcomes. It does so by quantifying an expert-elicited network of probabilistic relations between variables. Advantages of this modeling approach include (1) flexibility in accommodating many model specifications and information types; (2) efficiency in storing and manipulating complex information, and to parameterize; and (3) transparency in describing the relations using nodes and arrows and in describing uncertainties with discrete probability distributions for each variable.

  1. Case Study: Does training of private networks of Family Planning clinicians in urban Pakistan affect service utilization?

    OpenAIRE

    Qureshi, Asma M

    2010-01-01

    Abstract Background To determine whether training of providers participating in franchise clinic networks is associated with increased Family Planning service use among low-income urban families in Pakistan. Methods The study uses 2001 survey data consisting of interviews with 1113 clinical and non-clinical providers working in public and private hospitals/clinics. Data analysis excludes non-clinical providers reducing sample size to 822. Variables for the analysis are divided into client vol...

  2. Flying Real-Time Network to Coordinate Disaster Relief Activities in Urban Areas †

    Science.gov (United States)

    Micheletto, Matias; Orozco, Javier; Mosse, Daniel

    2018-01-01

    While there have been important advances within wireless communication technology, the provision of communication support during disaster relief activities remains an open issue. The literature in disaster research reports several major restrictions to conducting first response activities in urban areas, given the limitations of telephone networks and radio systems to provide digital communication in the field. In search-and-rescue operations, the communication requirements are increased, since the first responders need to rely on real-time and reliable communication to perform their activities and coordinate their efforts with other teams. Therefore, these limitations open the door to improvisation during disaster relief efforts. In this paper, we argue that flying ad-hoc networks can provide the communication support needed in these scenarios, and propose a new solution towards that goal. The proposal involves the use of flying witness units, implemented using drones, that act as communication gateways between first responders working at different locations of the affected area. The proposal is named the Flying Real-Time Network, and its feasibility to provide communication in a disaster scenario is shown by presenting both a real-time schedulability analysis of message delivery, as well as simulations of the communication support in a physical scenario inspired by a real incident. The obtained results were highly positive and consistent, therefore this proposal represents a step forward towards the solution of this open issue. PMID:29789458

  3. Network structure of subway passenger flows

    Science.gov (United States)

    Xu, Q.; Mao, B. H.; Bai, Y.

    2016-03-01

    The results of transportation infrastructure network analyses have been used to analyze complex networks in a topological context. However, most modeling approaches, including those based on complex network theory, do not fully account for real-life traffic patterns and may provide an incomplete view of network functions. This study utilizes trip data obtained from the Beijing Subway System to characterize individual passenger movement patterns. A directed weighted passenger flow network was constructed from the subway infrastructure network topology by incorporating trip data. The passenger flow networks exhibit several properties that can be characterized by power-law distributions based on flow size, and log-logistic distributions based on the fraction of boarding and departing passengers. The study also characterizes the temporal patterns of in-transit and waiting passengers and provides a hierarchical clustering structure for passenger flows. This hierarchical flow organization varies in the spatial domain. Ten cluster groups were identified, indicating a hierarchical urban polycentric structure composed of large concentrated flows at urban activity centers. These empirical findings provide insights regarding urban human mobility patterns within a large subway network.

  4. Roads Belong In the Urban Landscape

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2012-01-01

    In spite of being an essential part of the system of automobility and as such playing an important role in the development of urban landscapes, road networks seldom attracts much attention among architects involved in the planning and design of urban landscapes. One reason is probably found...... in the dominance of the zoning approach to planning, where road planning easily becomes isolated and reduced to a matter of traffic regulation and transport economy. Another possible reason could be, as suggested by the Australian landscape architect Christopher Sawyer, that road networks like other...... as landscape architects engage with road networks in profound ways, which moves beyond the purely visual and pictorial? Is it possible to conceptually (re)locate road networks in the landscape? The paper will address these questions by discussing different understandings of landscape and its relation...

  5. Heat networks in France in 2014. Heat networks: which price for the consumer?

    International Nuclear Information System (INIS)

    Reynaud, Didier; Gong, Zheng; Moreau, Sylvain; Bottin, Anne; Reperant, Patricia

    2016-04-01

    A first document publishes and comments various statistics regarding heat networks in France in 2014: distribution in terms of quantity of supplied heat, main urban units, distribution in terms of urban unit size and in terms of community type (land, isolated town, outskirts, centre town). It also indicates the types, percentages and evolution of energies consumed in these heat networks, the shares of fossil and renewable energies, and the distribution of networks in terms of energy type. Some regional data are briefly commented (energy shares in each region, number of primary housing connected to an urban heating network). This publication also indicates methodological aspects and the definitions of the main components and characteristics of a heat network. Notably based on some of these data, the second document comments the price of heat supplied in these heat networks in 2014 as these prices are not regulated and depend on agreements between clients and providers. These prices are analysed in terms of linear thermal density, of heat quantity supplied by delivery point, of sector (industry, housing, office building), of rate of renewable energy, and of operator status (public service delegation or private ownership)

  6. A "Network" and a "Dictum"

    DEFF Research Database (Denmark)

    Harder, Henrik

    2003-01-01

    safety and accessibility problems in the urban areas created by the car. The strong ideal shared by the people within the "network" were based on the dictum "forms follow function" about mans behaviour, the car and the structure of the urban areas and was based on very little empirical research. The use...... of the urban planning thoughts expressed as road planning principles indicated and supported a changing perception of the urban areas, although people in the "network" (Le Corbusier, F. and Clarence S. Stein, US) had very different ideas about how the urban ideal itself should be expressed. Basically......, the recommendation concerning traffic and specifically the car was the same, segregation. This shift in perception had spatial implications: Firstly through the recommendation of turning the individual urban (residential) areas inwards or upwards i.e. away from the car traffic on the streets. Secondly...

  7. Beyond urban legends: an emerging framework of urban ecology, as illustrated by the Baltimore Ecosystem Study

    Science.gov (United States)

    Steward T.A. Pickett; Mary L. Cadenasso; J. Morgan Grove; Peter M. Groffman; Lawrence E. Band; Christopher G. Boone; William R., Jr. Burch; Susan B. Grimmond; John Hom; Jennifer C. Jenkins; Neely L. Law; Charles H. Nilon; Richard V. Pouyat; Katalin Szlavecz; Paige S. Warren; Matthew A. Wilson

    2008-01-01

    The emerging discipline of urban ecology is shifting focus from ecological processes embedded within cities to integrative studies of large urban areas as biophysical-social complexes. Yet this discipline lacks a theory. Results from the Baltimore Ecosystem Study, part of the Long Term Ecological Research Network, expose new assumptions and test existing assumptions...

  8. Urban Automation Networks: Current and Emerging Solutions for Sensed Data Collection and Actuation in Smart Cities.

    Science.gov (United States)

    Gomez, Carles; Paradells, Josep

    2015-09-10

    Urban Automation Networks (UANs) are being deployed worldwide in order to enable Smart City applications. Given the crucial role of UANs, as well as their diversity, it is critically important to assess their properties and trade-offs. This article introduces the requirements and challenges for UANs, characterizes the main current and emerging UAN paradigms, provides guidelines for their design and/or choice, and comparatively examines their performance in terms of a variety of parameters including coverage, power consumption, latency, standardization status and economic cost.

  9. Urban Automation Networks: Current and Emerging Solutions for Sensed Data Collection and Actuation in Smart Cities

    Directory of Open Access Journals (Sweden)

    Carles Gomez

    2015-09-01

    Full Text Available Urban Automation Networks (UANs are being deployed worldwide in order to enable Smart City applications. Given the crucial role of UANs, as well as their diversity, it is critically important to assess their properties and trade-offs. This article introduces the requirements and challenges for UANs, characterizes the main current and emerging UAN paradigms, provides guidelines for their design and/or choice, and comparatively examines their performance in terms of a variety of parameters including coverage, power consumption, latency, standardization status and economic cost.

  10. Do motorways shape urban growth?

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick; Hovgesen, Henrik Harder

    2005-01-01

    results suggest that the motorway most markedly influences the location of non-residential building activities within the city – in favour of locations near the entrance points to/from the motorway network. The development can be explained in part by municipal planning, which in some instances has opened......The paper is an offspring from the Research project Town, Road and Landscape that aims to assess the effect of the Danish motorway network (specifically the last 20 years) on urban growth and interaction patterns. As one of the main interests of the project is the changing urban form...... and the changing character of the roadscape, the impact of the motorway is in part analysed with micro level data, spatial statistics and GIS – to allowing mapping of changing development trends in motorway corridors. The paper presents analysis of the impact of motorway openings on urban form in two Danish...

  11. Bushmeat networks link the forest to urban areas in the trifrontier region between Brazil, Colombia, and Peru

    Directory of Open Access Journals (Sweden)

    Nathalie van Vliet

    2015-09-01

    Full Text Available Recent studies have intended to quantify urban consumption and trade in Amazonian towns. However, little is still known about the different ways in which bushmeat is made available in urban areas, including commercial and noncommercial flows, and how those flows contribute to link forests to urban livelihoods. In this study we qualitatively describe the structure and functioning of bushmeat flows in terms of species, catchment area, stakeholders involved, and the motivations for their activity in the main towns of the Amazon trifrontier region between Brazil, Colombia, and Peru. We show that bushmeat trade to urban areas exists under an organized but invisible commodity chain providing a source of income to about 195 persons. Bushmeat is made available either directly from the hunter to the urban consumer, at the main market place, or in food stalls and restaurants. On the Colombian border, the trade is totally invisible, whereas in Peru and Brazil, bushmeat is sold in open markets despite regulations. The catchment area comprises the main rivers: up to Caballococha along the Amazon River, along the Atacuary River in Peru, along the Javari River between Peru and Brazil, and along the Loretoyacu and Amacayacu rivers in Colombia and in periurban forests. Although the trade is rather localized (no commercial flows to larger towns, international transborder trade is commonplace, disregarding Convention on International Trade in Endangered Species of Wild Fauna and Flora regulations. Bushmeat clients in urban areas are mainly nonindigenous or mestizos who can afford bushmeat as a luxury meal. Instead, indigenous people in urban areas do not access bushmeat through the market but rather through their social networks with whom they maintain noncommercial flows including immediate exchange and long-term exchange mechanisms. Although bushmeat is no longer consumed as a daily meal among urban and periurban indigenous families, it constitutes what could be

  12. Urban traffic simulated from the dual representation: Flow, crisis and congestion

    International Nuclear Information System (INIS)

    Hu Maobin; Jiang Rui; Wang Ruili; Wu Qingsong

    2009-01-01

    We propose a traffic simulation model for urban system based on the dual graph representation of a urban road network and with a random entering vehicle rate. To avoid the shortcoming of 'Space Syntax' of ignoring the road's metric distance, we consider both the motion of the vehicles along roads and the navigation of the vehicles in the network. Simulations have shown some basic properties of urban traffic system, such as flux fluctuation, crisis and dissipation, phase transition from a free flow to jams, overall capacity, the distribution of traveling time, and the fundamental diagram. The system's behavior greatly depends on the topology of the transportation network. A well-planned lattice grid can keep more vehicles travelling. The critical entering vehicle rate is much greater in lattice grid than in a self-organized network. The vehicles have to travel longer time in a self-organized urban system due to the navigation cost.

  13. Internet use and the network composition of people living with HIV/AIDS in an urban area in Peru.

    Science.gov (United States)

    Busse, Peter; Curioso, Walter H

    2010-12-01

    This study examines the association between Internet use and (1) the number of close ties (people with whom a person is closely acquainted), and (2) the percentage of HIV-positive individuals in the personal network of people living with HIV/AIDS (PLHA) in an urban area of Peru. Ninety-four PLHA responded to a survey; 72% were male, and the average age was 36.65 (SD = 7.92). Internet use was not associated with the number of close ties or with a greater number of close ties who are HIV-positive in one's personal network. Internet use was higher among those with greater than a high school education and females reported more social ties than males.

  14. Urban infrastructure influences dissolved organic matter quality and bacterial metabolism in an urban stream network

    Science.gov (United States)

    Urban streams are degraded by a suite of factors, including burial beneath urban infrastructure (i.e., roads, parking lots) that eliminates light and reduces direct organic matter inputs to streams, with likely consequences for organic matter metabolism by microbes and carbon lim...

  15. Predicting a roadkill hotspots based on spatial distribution of Korean water deer (Hydropotes inermis argyropus) using Maxent model in South Korea Expressway : In Case of Cheongju-Sangju Expressway

    Science.gov (United States)

    Park, Hyomin; Lee, Sangdon

    2016-04-01

    Road construction has direct and indirect effects on ecosystems. Especially wildlife-vehicle conflicts (roadkills) caused by roads are a considerable threat for population of many species. This study aims to identify the effects of topographic characteristics and spatial distribution of Korean water deer (Hydropotes inermis). Korean water deer is indigenous and native species in Korea that listed LC (least concern) by IUCN redlist categories. Korean water deer population is growing every year occupying for most of roadkills (>70%) in Korean express highway. In order to predict a distribution of the Korean water deer, we selected factors that most affected water deer's habitat. Major habitats of waterdeer are known as agricultural area, forest area and water. Based on this result, eight factors were selected (land cover map, vegetation map, age class of forest, diameter class of tree, population, slope of study site, elevation of study site, distance of river), and made a thematic map by using GIS program (ESRI, Arc GIS 10.3.1 ver.). To analyze the affected factors of waterdeer distribution, GPS data and thematic map of study area were entered into Maxent model (Maxent 3.3.3.k.). Results of analysis were verified by the AUC (Area Unit Curve) of ROC (Receiver Operating Characteristic). The ROC curve used the sensitivity and specificity as a reference for determining the prediction efficiency of the model and AUC area of ROC curve was higher prediction efficiency closer to '1.' Selecting factors that affected the distribution of waterdeer were land cover map, diameter class of tree and elevation of study site. The value of AUC was 0.623. To predict the water deer's roadkills hot spot on Cheongju-Sangju Expressway, the thematic map was prepared based on GPS data of roadkill spots. As a result, the topographic factors that affected waterdeer roadkill were land cover map, actual vegetation map and age class of forest and the value of AUC was 0.854. Through this study, we

  16. Incorporating real-time traffic and weather data to explore road accident likelihood and severity in urban arterials.

    Science.gov (United States)

    Theofilatos, Athanasios

    2017-06-01

    The effective treatment of road accidents and thus the enhancement of road safety is a major concern to societies due to the losses in human lives and the economic and social costs. The investigation of road accident likelihood and severity by utilizing real-time traffic and weather data has recently received significant attention by researchers. However, collected data mainly stem from freeways and expressways. Consequently, the aim of the present paper is to add to the current knowledge by investigating accident likelihood and severity by exploiting real-time traffic and weather data collected from urban arterials in Athens, Greece. Random Forests (RF) are firstly applied for preliminary analysis purposes. More specifically, it is aimed to rank candidate variables according to their relevant importance and provide a first insight on the potential significant variables. Then, Bayesian logistic regression as well finite mixture and mixed effects logit models are applied to further explore factors associated with accident likelihood and severity respectively. Regarding accident likelihood, the Bayesian logistic regression showed that variations in traffic significantly influence accident occurrence. On the other hand, accident severity analysis revealed a generally mixed influence of traffic variations on accident severity, although international literature states that traffic variations increase severity. Lastly, weather parameters did not find to have a direct influence on accident likelihood or severity. The study added to the current knowledge by incorporating real-time traffic and weather data from urban arterials to investigate accident occurrence and accident severity mechanisms. The identification of risk factors can lead to the development of effective traffic management strategies to reduce accident occurrence and severity of injuries in urban arterials. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

  17. Structural change in a system of urban places: the 20th-century evolution of Hungary's urban settlement network.

    Science.gov (United States)

    Zovanyi, G

    1986-02-01

    A review of urban change in Hungary in the twentieth century is presented. Both the traditional approach to studying urban change, involving changes in the percentage of those residing in urban areas, and the newly developed approach, focusing on regional aspects of urbanization, are used in the analysis. "In sharp contrast to most European countries Hungary is shown to evidence continued centralization of urban development, but the recent experience of Budapest and other indicators are said to portend future decentralization." (summary in FRE, GER) excerpt

  18. Urban rivers as hotspots of regional nitrogen pollution

    International Nuclear Information System (INIS)

    Zhang, Xiaohong; Wu, Yiyun; Gu, Baojing

    2015-01-01

    Excess nitrogen inputs to terrestrial ecosystems via human activities have deteriorated water qualities on regional scales. Urban areas as settlements of over half global population, however, were usually not considered in the analysis of regional water pollution. Here, we used a 72-month monitoring data of water qualities in Hangzhou, China to test the role of urban rives in regional nitrogen pollution and how they response to the changes of human activities. Concentrations of ammonium nitrogen in urban rivers were 3–5 times higher than that in regional rivers. Urban rivers have become pools of reactive nitrogen and hotspots of regional pollution. Moreover, this river pollution is not being measured by current surface water monitoring networks that are designed to measure broader regional patterns, resulting in an underestimation of regional pollution. This is crucial to urban environment not only in China, but also in other countries, where urban rivers are seriously polluted. - Highlights: • Nitrogen concentrations in urban rivers are much higher than that in regional rivers. • Domestic wastewater is the main source of urban river pollution in Hangzhou. • Pollutant collecting and water diversion can sharply reduce the urban river pollution. - Urban river pollution is not being measured by the current monitoring networks that are designed to measure regional patterns causing an underestimation

  19. Indoor-air microbiome in an urban subway network: diversity and dynamics.

    Science.gov (United States)

    Leung, Marcus H Y; Wilkins, David; Li, Ellen K T; Kong, Fred K F; Lee, Patrick K H

    2014-11-01

    Subway systems are indispensable for urban societies, but microbiological characteristics of subway aerosols are relatively unknown. Previous studies investigating microbial compositions in subways employed methodologies that underestimated the diversity of microbial exposure for commuters, with little focus on factors governing subway air microbiology, which may have public health implications. Here, a culture-independent approach unraveling the bacterial diversity within the urban subway network in Hong Kong is presented. Aerosol samples from multiple subway lines and outdoor locations were collected. Targeting the 16S rRNA gene V4 region, extensive taxonomic diversity was found, with the most common bacterial genera in the subway environment among those associated with skin. Overall, subway lines harbored different phylogenetic communities based on α- and β-diversity comparisons, and closer inspection suggests that each community within a line is dependent on architectural characteristics, nearby outdoor microbiomes, and connectedness with other lines. Microbial diversities and assemblages also varied depending on the day sampled, as well as the time of day, and changes in microbial communities between peak and nonpeak commuting hours were attributed largely to increases in skin-associated genera in peak samples. Microbial diversities within the subway were influenced by temperature and relative humidity, while carbon dioxide levels showed a positive correlation with abundances of commuter-associated genera. This Hong Kong data set and communities from previous studies conducted in the United States formed distinct community clusters, indicating that additional work is required to unravel the mechanisms that shape subway microbiomes around the globe. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  20. MUWS (Microbiology in Urban Water Systems – an interdisciplinary approach to study microbial communities in urban water systems

    Directory of Open Access Journals (Sweden)

    P. Deines

    2010-07-01

    Full Text Available Microbiology in Urban Water Systems (MUWS is an integrated project, which aims to characterize the microorganisms found in both potable water distribution systems and sewer networks. These large infrastructure systems have a major impact on our quality of life, and despite the importance of these systems as major components of the water cycle, little is known about their microbial ecology. Potable water distribution systems and sewer networks are both large, highly interconnected, dynamic, subject to time and varying inputs and demands, and difficult to control. Their performance also faces increasing loading due to increasing urbanization and longer-term environmental changes. Therefore, understanding the link between microbial ecology and any potential impacts on short or long-term engineering performance within urban water infrastructure systems is important. By combining the strengths and research expertise of civil-, biochemical engineers and molecular microbial ecologists, we ultimately aim to link microbial community abundance, diversity and function to physical and engineering variables so that novel insights into the performance and management of both water distribution systems and sewer networks can be explored. By presenting the details and principals behind the molecular microbiological techniques that we use, this paper demonstrates the potential of an integrated approach to better understand how urban water system function, and so meet future challenges.

  1. Strategic Planning & Urban Projects : Responses to Globalization from 15 cities

    NARCIS (Netherlands)

    Carmona, M.; Burgess, R.

    2001-01-01

    This book draws upon the ongoing research activities of agiobal network of urban researchers - the IBIS network. The IBIS network is a European Community funded network of four European universities and South American universities. The network involves postgraduate student exchanges and the

  2. Measuring the Complexity of Urban Form and Design

    OpenAIRE

    Boeing, Geoff

    2017-01-01

    Complex systems have become a popular lens for conceptualizing cities, and complexity has substantial implications for urban performance and resilience. This paper develops a typology of methods and measures for assessing the complexity of the built form at the scale of urban design. It extends quantitative methods from urban planning, network science, ecosystems studies, fractal geometry, and information theory to the physical urban form and the analysis of qualitative human experience. Metr...

  3. Website applications in urbanism and architecture

    Directory of Open Access Journals (Sweden)

    Furundžić Danilo S.

    2003-01-01

    Full Text Available In the context of rapid technology development, followed by Internet spreading worldwide, the amount of information related to urbanism and architecture has remarkably increased. This paper lists a website selection with the aim to present the state of Internet based information sources on urbanism and architecture. The idea is to help colleagues cope with numerous available on-line contents. The websites are, according to their contents, classified into following categories: associations and institutions, international documents, urban planning and design, information and communication technologies in urbanism, on-line available magazines and books, civic networks, architectural design, famous architects and best examples.

  4. A REDE URBANA EM GOIÁS: UMA ANÁLISE DO PADRÃO ESPACIAL NA PRIMEIRA DÉCADA DO SÉCULO XXI / THE URBAN NETWORK IN GOIÁS: AN ANALYSIS OF SPATIAL PATTERN IN THE FIRST DECADE OF THIS CENTURY XXI.

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Roscoche

    2017-08-01

    Full Text Available The urban network corresponds to the articulation of urban centers through its functions. From considerations of this concept will be discussed in this paper the spatial pattern of the urban network in Goiás, being guided by the analysis of secondary data studies of Areas of Influence of Cities (REGIC and other surveys released by the Brazilian Institute of Geography and Statistics (IBGE. In this sense, the objective is to understand the genesis and development of the urban network of Goiás, highlighting its main building blocks. It presents the assumption that the presence of two cities in the territory of Goiás - Goiânia and Brasília - provides a private setting at the national level, indicating the absence of intermediate urban centers (regional capital as a result of the centrality exercised by the two cities.

  5. Introduction to Global Urban Climatology

    Science.gov (United States)

    Varquez, A. C. G.; Kanda, M.; Kawano, N.; Darmanto, N. S.; Dong, Y.

    2016-12-01

    Urban heat island (UHI) is a widely investigated phenomenon in the field of urban climate characterized by the warming of urban areas relative to its surrounding rural environs. Being able to understand the mechanism behind the UHI formation of a city and distinguish its impact from that of global climate change is indispensable when identifying adaptation and mitigation strategies. However, the lack of UHI studies many cities especially for developing countries makes it difficult to generalize the mechanism for UHI formation. Thus, there is an impending demand for studies that focus on the simultaneous analyses of UHI and its trends throughout the world. Hence, we propose a subfield of urban climatology, called "global urban climatology" (GUC), which mainly focuses on the uniform understanding of urban climates across all cities, globally. By using globally applicable methodologies to quantify and compare urban heat islands of cities with diverse backgrounds, including their geography, climate, socio-demography, and other factors, a universal understanding of the mechanisms underlying the formation of the phenomenon can be established. The implementation of GUC involves the use of globally acquired historical observation networks, gridded meteorological parameters from climate models, global geographic information system datasets; the construction of a distributed urban parameter database; and the development of techniques necessary to model the urban climate. Research under GUC can be categorized into three approaches. The collaborative approach (1st) relies on the collection of data from micro-scale experiments conducted worldwide with the aid or development of professional social networking platforms; the analytical approach (2nd) relies on the use of global weather station datasets and their corresponding objectively analysed global outputs; and the numerical approach (3rd) relies on the global estimation of high-resolution urban-representative parameters as

  6. A window on urban sustainability

    International Nuclear Information System (INIS)

    Stigt, Rien van; Driessen, Peter P.J.; Spit, Tejo J.M.

    2013-01-01

    Sustainable urban development requires the integration of environmental interests in urban planning. Although various methods of environmental assessment have been developed, plan outcomes are often disappointing due to the complex nature of decision-making in urban planning, which takes place in multiple arenas within multiple policy networks involving diverse stakeholders. We argue that the concept of ‘decision windows’ can structure this seemingly chaotic chain of interrelated decisions. First, explicitly considering the dynamics of the decision-making process, we further conceptualized decision windows as moments in an intricate web of substantively connected deliberative processes where issues are reframed within a decision-making arena, and interests may be linked within and across arenas. Adopting this perspective in two case studies, we then explored how decision windows arise, which factors determine their effectiveness and how their occurrence can be influenced so as to arrive at more sustainable solutions. We conclude that the integration of environmental interests in urban planning is highly dependent on the ability of the professionals involved to recognize and manipulate decision windows. Finally, we explore how decision windows may be opened. -- Highlights: • Decision-making about sustainable urban development occurs in networks. • The concept of ‘decision windows’ was further elaborated. • Decision windows help understand how environmental interests enter decision-making. • Decision windows can, to some extent, be influenced

  7. A window on urban sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Stigt, Rien van, E-mail: rien.vanstigt@hu.nl [Research Center for Technology and Innovation, Utrecht University of Applied Sciences, P.O. Box 182, 3500 AD Utrecht (Netherlands); Driessen, Peter P.J., E-mail: p.driessen@uu.nl [Copernicus Institute of Sustainable Development, Faculty of Geosciences, Utrecht University, P.O. Box 80.115, 3508 TC Utrecht (Netherlands); Spit, Tejo J.M., E-mail: T.J.M.Spit@uu.nl [Department of Human Geography and Spatial Planning, Faculty of Geosciences, Utrecht University, P.O. Box 80.115, 3508 TC Utrecht (Netherlands)

    2013-09-15

    Sustainable urban development requires the integration of environmental interests in urban planning. Although various methods of environmental assessment have been developed, plan outcomes are often disappointing due to the complex nature of decision-making in urban planning, which takes place in multiple arenas within multiple policy networks involving diverse stakeholders. We argue that the concept of ‘decision windows’ can structure this seemingly chaotic chain of interrelated decisions. First, explicitly considering the dynamics of the decision-making process, we further conceptualized decision windows as moments in an intricate web of substantively connected deliberative processes where issues are reframed within a decision-making arena, and interests may be linked within and across arenas. Adopting this perspective in two case studies, we then explored how decision windows arise, which factors determine their effectiveness and how their occurrence can be influenced so as to arrive at more sustainable solutions. We conclude that the integration of environmental interests in urban planning is highly dependent on the ability of the professionals involved to recognize and manipulate decision windows. Finally, we explore how decision windows may be opened. -- Highlights: • Decision-making about sustainable urban development occurs in networks. • The concept of ‘decision windows’ was further elaborated. • Decision windows help understand how environmental interests enter decision-making. • Decision windows can, to some extent, be influenced.

  8. Power-Hop: A Pervasive Observation for Real Complex Networks

    Science.gov (United States)

    2016-03-14

    e.g., power grid, the Internet and the web-graph), social (e.g., friendship networks — Facebook , Gowalla—and co- authorship networks ), urban (e.g...Mislove A., Cha M. and Gummadi K.P. On the evolution of user interaction in Facebook . In Proc. Workshop on Online Social Networks 2009. doi...scale-free distribution is pervasive and describes a large variety of networks , ranging from social and urban to technological and biological networks

  9. “Coming to Town”: The Impact of Urbanicity, Cigarette Advertising, and Network Norms on the Smoking Attitudes of Black Women in Cape Town, South Africa

    OpenAIRE

    Williams, Chyvette T.; Grier, Sonya A.; Marks, Amy Seidel

    2008-01-01

    This study was conducted to examine the effect of urban living on smoking attitudes among black African women in South Africa. We examine how urbanicity affects attitudes toward smoking and how it moderates the relationship between both advertising exposure and network norms on black women’s smoking attitudes. Respondents were 975 black women currently living in Cape Town townships, some of which were raised in rural villages or small towns. Respondents completed a cross-sectional survey, whi...

  10. City Expansion and Agricultural Land Loss within the Peri-Urban ...

    African Journals Online (AJOL)

    1 Department of Urban and Regional Planning, University of Ibadan, Oyo .... physical development as a result of interaction between urban and rural land uses. ..... This research adopted a descriptive survey and a case study approach. ...... Environment Research Network (PERN) Cyber seminar, Urban Expansion: The ...

  11. Vehicular Visible Light Networks for Urban Mobile Crowd Sensing

    Directory of Open Access Journals (Sweden)

    Barbara M. Masini

    2018-04-01

    Full Text Available Crowd sensing is a powerful tool to map and predict interests and events. In the future, it could be boosted by an increasing number of connected vehicles sharing information and intentions. This will be made available by on board wireless connected devices able to continuously communicate with other vehicles and with the environment. Among the enabling technologies, visible light communication (VLC represents a low cost solution in the short term. In spite of the fact that vehicular communications cannot rely on the sole VLC due to the limitation provided by the light which allows communications in visibility only, VLC can however be considered to complement other wireless communication technologies which could be overloaded in dense scenarios. In this paper we evaluate the performance of VLC connected vehicles when urban crowd sensing is addressed and we compare the performance of sole vehicular visible light networks with that of VLC as a complementary technology of IEEE 802.11p. Results, obtained through a realistic simulation tool taking into account both the roadmap constraints and the technologies protocols, help to understand when VLC provides the major improvement in terms of delivered data varying the number and position of RSUs and the FOV of the receiver.

  12. Vehicular Visible Light Networks for Urban Mobile Crowd Sensing.

    Science.gov (United States)

    Masini, Barbara M; Bazzi, Alessandro; Zanella, Alberto

    2018-04-12

    Crowd sensing is a powerful tool to map and predict interests and events. In the future, it could be boosted by an increasing number of connected vehicles sharing information and intentions. This will be made available by on board wireless connected devices able to continuously communicate with other vehicles and with the environment. Among the enabling technologies, visible light communication (VLC) represents a low cost solution in the short term. In spite of the fact that vehicular communications cannot rely on the sole VLC due to the limitation provided by the light which allows communications in visibility only, VLC can however be considered to complement other wireless communication technologies which could be overloaded in dense scenarios. In this paper we evaluate the performance of VLC connected vehicles when urban crowd sensing is addressed and we compare the performance of sole vehicular visible light networks with that of VLC as a complementary technology of IEEE 802.11p. Results, obtained through a realistic simulation tool taking into account both the roadmap constraints and the technologies protocols, help to understand when VLC provides the major improvement in terms of delivered data varying the number and position of RSUs and the FOV of the receiver.

  13. Neighborhood and Network Disadvantage among Urban Renters

    Directory of Open Access Journals (Sweden)

    Matthew Desmond

    2015-06-01

    Full Text Available Drawing on novel survey data, this study maps the distribution of neighborhood and network disadvantage in a population of Milwaukee renters and evaluates the relationship between each disadvantage and multiple social and health outcomes. We find that many families live in neighborhoods with above average disadvantage but are embedded in networks with below average disadvantage, and vice versa. Neighborhood (but not network disadvantage is associated with lower levels of neighborly trust but also with higher levels of community support (e.g., providing neighbors with food. Network (but not neighborhood disadvantage is associated with lower levels of civic engagement. Asthma and diabetes are associated exclusively with neighborhood disadvantage, but depression is associated exclusively with network disadvantage. These findings imply that some social problems may be better addressed by neighborhood interventions and others by network interventions.

  14. Data-driven modeling of solar-powered urban microgrids.

    Science.gov (United States)

    Halu, Arda; Scala, Antonio; Khiyami, Abdulaziz; González, Marta C

    2016-01-01

    Distributed generation takes center stage in today's rapidly changing energy landscape. Particularly, locally matching demand and generation in the form of microgrids is becoming a promising alternative to the central distribution paradigm. Infrastructure networks have long been a major focus of complex networks research with their spatial considerations. We present a systemic study of solar-powered microgrids in the urban context, obeying real hourly consumption patterns and spatial constraints of the city. We propose a microgrid model and study its citywide implementation, identifying the self-sufficiency and temporal properties of microgrids. Using a simple optimization scheme, we find microgrid configurations that result in increased resilience under cost constraints. We characterize load-related failures solving power flows in the networks, and we show the robustness behavior of urban microgrids with respect to optimization using percolation methods. Our findings hint at the existence of an optimal balance between cost and robustness in urban microgrids.

  15. Analyses and optimization of Lee propagation model for LoRa 868 MHz network deployments in urban areas

    Directory of Open Access Journals (Sweden)

    Dobrilović Dalibor

    2017-01-01

    Full Text Available In the recent period, fast ICT expansion and rapid appearance of new technologies raised the importance of fast and accurate planning and deployment of emerging communication technologies, especially wireless ones. In this paper is analyzed possible usage of Lee propagation model for planning, design and management of networks based on LoRa 868MHz technology. LoRa is wireless technology which can be deployed in various Internet of Things and Smart City scenarios in urban areas. The analyses are based on comparison of field measurements with model calculations. Besides the analyses of Lee propagation model usability, the possible optimization of the model is discussed as well. The research results can be used for accurate design, planning and for preparation of high-performance wireless resource management of various Internet of Things and Smart City applications in urban areas based on LoRa or similar wireless technology. The equipment used for measurements is based on open-source hardware.

  16. Assessing measurement uncertainty in meteorology in urban environments

    International Nuclear Information System (INIS)

    Curci, S; Lavecchia, C; Frustaci, G; Pilati, S; Paganelli, C; Paolini, R

    2017-01-01

    Measurement uncertainty in meteorology has been addressed in a number of recent projects. In urban environments, uncertainty is also affected by local effects which are more difficult to deal with than for synoptic stations. In Italy, beginning in 2010, an urban meteorological network (Climate Network ® ) was designed, set up and managed at national level according to high metrological standards and homogeneity criteria to support energy applications. The availability of such a high-quality operative automatic weather station network represents an opportunity to investigate the effects of station siting and sensor exposure and to estimate the related measurement uncertainty. An extended metadata set was established for the stations in Milan, including siting and exposure details. Statistical analysis on an almost 3-year-long operational period assessed network homogeneity, quality and reliability. Deviations from reference mean values were then evaluated in selected low-gradient local weather situations in order to investigate siting and exposure effects. In this paper the methodology is depicted and preliminary results of its application to air temperature discussed; this allowed the setting of an upper limit of 1 °C for the added measurement uncertainty at the top of the urban canopy layer. (paper)

  17. Assessing measurement uncertainty in meteorology in urban environments

    Science.gov (United States)

    Curci, S.; Lavecchia, C.; Frustaci, G.; Paolini, R.; Pilati, S.; Paganelli, C.

    2017-10-01

    Measurement uncertainty in meteorology has been addressed in a number of recent projects. In urban environments, uncertainty is also affected by local effects which are more difficult to deal with than for synoptic stations. In Italy, beginning in 2010, an urban meteorological network (Climate Network®) was designed, set up and managed at national level according to high metrological standards and homogeneity criteria to support energy applications. The availability of such a high-quality operative automatic weather station network represents an opportunity to investigate the effects of station siting and sensor exposure and to estimate the related measurement uncertainty. An extended metadata set was established for the stations in Milan, including siting and exposure details. Statistical analysis on an almost 3-year-long operational period assessed network homogeneity, quality and reliability. Deviations from reference mean values were then evaluated in selected low-gradient local weather situations in order to investigate siting and exposure effects. In this paper the methodology is depicted and preliminary results of its application to air temperature discussed; this allowed the setting of an upper limit of 1 °C for the added measurement uncertainty at the top of the urban canopy layer.

  18. From the network city to the neo-liberal city

    DEFF Research Database (Denmark)

    Ribeiro, Gustavo

    2005-01-01

    Network Cities: Globalization and Urban Transformation in Oslo, Stockholm and Copenhagen aims to probe relationships between planning discourses, planning practices and urban transformations. By bringing together practitioners and academics we aim at focussing the discussion on developments...... in the three Schandinavian capitals, namely Oslo, Stockholm and Copenhagen. Relationships between urban transformations and global networks (economic, cultural, informational), are closely related to considerations by planners, decision makers and academics about themes such as the competition between cities......, the forging of regional identities, the impact of information technologies on urban development, the development of networked infrastructures (transport, telecommunications) and spatial consequences such as the changing status of public space, social polarization, amongst others. The central purpose...

  19. Construction of road network vulnerability evaluation index based on general travel cost

    Science.gov (United States)

    Leng, Jun-qiang; Zhai, Jing; Li, Qian-wen; Zhao, Lin

    2018-03-01

    With the development of China's economy and the continuous improvement of her urban road network, the vulnerability of the urban road network has attracted increasing attention. Based on general travel cost, this work constructs the vulnerability evaluation index for the urban road network, and evaluates the vulnerability of the urban road network from the perspective of user generalised travel cost. Firstly, the generalised travel cost model is constructed based on vehicle cost, travel time, and traveller comfort. Then, the network efficiency index is selected as an evaluation index of vulnerability: the network efficiency index is composed of the traffic volume and the generalised travel cost, which are obtained from the equilibrium state of the network. In addition, the research analyses the influence of traffic capacity decrease, road section attribute value, and location of road section, on vulnerability. Finally, the vulnerability index is used to analyse the local area network of Harbin and verify its applicability.

  20. Unsustaineble pseudo-urban consequences of legal and urban terminology

    Directory of Open Access Journals (Sweden)

    Ćerimović Velimir Lj.

    2011-01-01

    Full Text Available City planning is a complex task and through this work we face the space and natural resources that expose the exploitation (that are to be exploited and prone to unsustainable change. Often without environmental responsibility and the imperative of creating certain measures we make superstructure no matter how much the environment may be disrupted, and whether such relationships create a better society, better network of urban settlements and a better man. At that may also affect our knowledge which is often due to a variety of doctrines and legislative regulations that are applied in the planning and management space. From this it can be seen that modern architecture did not contribute to the creation of better cities. Also, urban planning is mainly restricted to the regulation and it neglected the creative action, regional-planning is lost in theoretical research, while the consideration of the whole problem is abandoned. In addition to this, in today’s transitional terms and the domineering (dominant urban crisis unsustainable combination and identification of the “2D” and the “3D” terminology is recognizable, which is only indicators that in the field of urban planning some transitional trends are prevailing. This unsustainable state of affairs in the transitional planning of urban areas can be applied in the most suitable way to pseudo-urbanization, sub-urbanization, unbalanced eco-reciprocity, non-standard construction of the urban tissue, discontinuity inherited and newly constructed urban substance. In this regard, consequently expressed negative environmental legacy of reproduction and the increased effect of the negative consequences of greenhouse gases from the threatening climate change, only shows that urban planners are not sinless and, they more or less (unconsciously complicit and participate in the contamination of urban and environment. In the end, it definitely guides us to the need to leave or transformation of the

  1. Urban flood mitigation planning for Guwahati: A case of Bharalu basin.

    Science.gov (United States)

    Sarmah, Tanaya; Das, Sutapa

    2018-01-15

    Guwahati, the capital city of Assam and the gateway to the seven north-eastern Indian states, is located in the Brahmaputra valley-one of the most flood prone regions of the world. The city receives an average annual rainfall of 1688 mm and is highly vulnerable towards frequent urban floods because of uncontrolled dumping of solid waste and siltation have choked the natural water channels. This coupled with the absence of an integrated drainage network and rapid urbanisation causes floods in many parts of the city, after a quick downpour. Bharalu river is the main natural water channel of the city and Bharalu basin is the most vulnerable one. The present paper is an attempt to plan for urban flood mitigation, by designing an integrated drainage network for the Bharalu basin which includes the low-lying urbanized areas bordered by the Guwahati-Shillong Road, the Radha Gobindo Baruah Road and the Rajgarh Road. Data regarding land use, flood level, rainfall, urban pattern and vulnerability towards urban flood were collected from available literature, field survey to find highest water level for 11.4 km road stretch, expert opinion survey from 18 experts and feedback from 77 community elders who have been residing in the city since the 1980s. The Bharalu basin is divided into seven drainage blocks and storm run-off has been calculated based on the inputs. Seven different trapezoidal drainage sections were designed to form an integrated drainage network which is 'self-healing' to a certain extent. This can serve as a template for the other catchment basins and to design a drainage network for the entire Guwahati city, thereby reducing urban flood hazard to a significant extent. The study illustrates the necessity of an urban flood mitigation planning approach in sub-Himalayan urban settlements such as Guwahati. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Urban Interaction Design

    DEFF Research Database (Denmark)

    Brynskov, Martin; Bermúdez, Juan Carlos Carvajal; Fernández, Manu

    This book is an effort to explore the newly emerging field of urban interaction design that addresses these issues. In the first part of the book, 'Foundations', we look into its origins. Where do its practitioners come from? How are they working together? What methodologies do they bring...... to the table? What are the key concepts they are addressing in their work? In the second part of the book named 'Trends', we go into current developments in the networked city and how urban interaction design as a field addresses these. Taken together, these sections will not give the definite definition...

  3. African Urban Harvest: Agriculture in the Cities of Cameroon, Kenya ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-01-01

    Jan 1, 2010 ... Over the past two decades, how has urban agriculture changed in sub-Saharan Africa? ... and urban environment present a unique collection of case studies that ... Prior to that, he led a network in Asia that supported research and ... was the sub-Saharan Africa Regional Coordinator for Urban Harvest.

  4. The informal sector in urban Nigeria: Reflections from almost four ...

    African Journals Online (AJOL)

    It was the ILO city-study mission to Lagos in 1975 that pioneered the concept ... Manie Geyer (Director), Centre for Regional & Urban Innovation and Statistical .... reverse is the case with men (65.2%) ... titled Urban development, income ..... banks (26.6%-31.6%); cooperative ...... network: Exploring the matters arising. Urban ...

  5. Redes verdes y planeamiento urbanístico

    Directory of Open Access Journals (Sweden)

    Francesca Lotta

    2013-09-01

    Abstract: The importance of Urban Planning’s role to safeguard green areas and to build up green chains has gradually increased. The latter played not only an ecological function into the city’s environment requalification, but it becomes also an occasion to find social space. The present research thesis investigated the concept of the green chain, the declination and implementation modes that this topic had in the local planning instrument and, more specifically, in which way the urban planning is working to defining and managing the reticular continuity. Proceeding from the terminology analysis of network and system concepts, the research intended to identify and to characterize the current use of these terms into the planning legislation, both into the national and regional levels, and moreover to study the implementation that the network concept get into the planning instrument. Two European situations were explored, Italian and Spanish: a comparative and descriptive methodology was used to analyze the different interpretations and use of the green chainsterms into the national and local scale (Ferraraand Santiago de Compostela towns. The different use of urban planning terms in the theoretical and practical evolution of green chain concept was described from model to paradigm and still to process. The investigation aimed to understanding the different paths on which the planning practices are moving to create and manage network systems of green and urban spaces.

  6. Modelling the impact of Water Sensitive Urban Design technologies on the urban water cycle

    DEFF Research Database (Denmark)

    Locatelli, Luca

    Alternative stormwater management approaches for urban developments, also called Water Sensitive Urban Design (WSUD), are increasingly being adopted with the aims of providing flood control, flow management, water quality improvements and opportunities to harvest stormwater for non-potable uses....... To model the interaction of infiltration based WSUDs with groundwater. 4. To assess a new combination of different WSUD techniques for improved stormwater management. 5. To model the impact of a widespread implementation of multiple soakaway systems at the catchment scale. 6. Test the models by simulating...... the hydrological performance of single devices relevant for urban drainage applications. Moreover, the coupling of soakaway and detention storages is also modeled to analyze the benefits of combining different local stormwater management systems. These models are then integrated into urban drainage network models...

  7. Does Urban Form Affect Urban NO2? Satellite-Based Evidence for More than 1200 Cities.

    Science.gov (United States)

    Bechle, Matthew J; Millet, Dylan B; Marshall, Julian D

    2017-11-07

    Modifying urban form may be a strategy to mitigate urban air pollution. For example, evidence suggests that urban form can affect motor vehicle usage, a major contributor to urban air pollution. We use satellite-based measurements of urban form and nitrogen dioxide (NO 2 ) to explore relationships between urban form and air pollution for a global data  set of 1274 cities. Three of the urban form metrics studied (contiguity, circularity, and vegetation) have a statistically significant relationship with urban NO 2 ; their combined effect could be substantial. As illustration, if findings presented here are causal, that would suggest that if Christchurch, New Zealand (a city at the 75th percentile for all three urban-form metrics, and with a network of buses, trams, and bicycle facilities) was transformed to match the urban form of Indio - Cathedral City, California, United States (a city at the 25th percentile for those same metrics, and exhibiting sprawl-like suburban development), our models suggest that Christchurch's NO 2 concentrations would be ∼60% higher than its current level. We also find that the combined effect of urban form on NO 2 is larger for small cities (β × IQR = -0.46 for cities urban population and are where much of the future urban growth is expected to occur. This work highlights the need for future study of how changes in urban form and related land use and transportation policies impact urban air pollution, especially for small cities.

  8. Mathematical Modeling of Air Flowfield at Urban Environment: the Case of Road Network at the Historical Centre of Kifissia's Municipality

    Science.gov (United States)

    Papakonstantinou, K.; Belias, C.

    2008-09-01

    The present paper refers to the numerical analysis of air flowfield at urban environments and the conducting thermal comfort after the evaluation of the examined space using CFD methods, taking into account bioclimatic principles at the architectural design. More specially, the paper draws attention to the physical procedures governing air movement at an urban environment (a road network) at Kifissia (a Municipality of north Athens), trying to form them in such way that will lead to the thermal comfort of the area's users. The study presents a mathematical model, implemented in a general computer code that can provide detailed information on velocity, prevailing in three-dimensional spaces of any geometrical complexity. Turbulent flow is simulated and buoyancy effects are taken into account. This simulation procedure is intended to contribute to the effort towards designing urban environments, using thermal comfort criteria at the bioclimatic design. A computer model of this kind will provide the architects or the environmental engineers with powerful and economical means of evaluating alternative spaces' designs.

  9. Beyond passive consumption : Dis/ordering water supply and sanitation at Hanoi’s urban edge

    NARCIS (Netherlands)

    Schramm, S.; Wright-Contreras, Lucía

    2017-01-01

    In Hanoi people access, expand and create water and sanitation infrastructures in multiple ways that include, but are not restricted to, external provision of networked services. Urban master planning and the construction of large technological networks aim at integrating the urban region based on

  10. Implications of Urban Development-Induced Resettlement on Poor ...

    African Journals Online (AJOL)

    They are moved away from their areas of work, their social networks .... for Urban Development and Urban Good Governance (FDRE 2007) discusses the three pillars ... about their experiences of past practices of resettlement. ..... women and single-headed families, empowering such families to enable them to engage in ...

  11. Key Challenges and Potential Urban Modelling Opportunities in ...

    African Journals Online (AJOL)

    Chris Wray

    1Gauteng City-Region Observatory (GCRO), a partnership between the University of ... and guide urban development that is socially, economically and ecologically .... new transport network link may result in an increased investment in land and .... determinants of urban growth in the period 1993-2000 through a case study ...

  12. Synchronization between Different Networks with Time-Varying Delay and Its Application in Bilayer Coupled Public Traffic Network

    Directory of Open Access Journals (Sweden)

    Wenju Du

    2016-01-01

    Full Text Available In order to study the dynamic characteristics of urban public traffic network, this paper establishes the conventional bus traffic network and the urban rail traffic network based on the space R modeling method. Then regarding these two networks as the subnetwork, the paper presents a new bilayer coupled public traffic network through the transfer relationship between subway and bus, and this model well reflects the connection between the passengers and bus operating vehicles. Based on the synchronization theory of coupling network with time-varying delay and taking “Lorenz system” as the network node, the paper studies the synchronization of bilayer coupled public traffic network. Finally, numerical results are given to show the impact of public traffic dispatching, delayed departure, the number of public bus stops between bus lines, and the number of transfer stations between two traffic modes on the bilayer coupled public traffic network balance through Matlab simulation.

  13. The transformation in the urban ecosystems

    International Nuclear Information System (INIS)

    Camargo Ponce de Leon, German

    2002-01-01

    In the last century cities has grown until representing about 80% of world population. Urban environment has grown more in population than in extension. Today more people than ever lives and construct urban environments, the question is not about people and human events that have concentrated in the frontiers of a few settlements, but about urban relationships from and beyond the cities. Urban determination of all fluxes and interchanges has spread over the earth, covered and controlled today by a vast urban-regional networks. In which way cities grows from the social nature and the ecological human behavior, as a need for evolution, is a relevant question in the analysis about the increasing way in which earth and the human habitat are transformed. Is this question that is addressed in some detail in this paper

  14. Tiering strategic environmental assessment and project environmental impact assessment in highway planning in Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Sanchez, Luis E.; Silva-Sanchez, Solange S.

    2008-01-01

    Constructing highways in dense urban areas is always a challenge. In Sao Paulo Metropolitan Region, heavy truck traffic contributes to clog streets and expressways alike. As part of the traffic neither originates nor head to the region, a peripheral highway has been proposed to reduce traffic problems. This project, called Rodoanel, is an expressway approximately 175 km long. The fact that the projected south and north sections would cross catchments that supply most of the metropolis water demand was strongly disputed and made the environmental permitting process particularly difficult. The agency in charge commissioned a strategic environmental assessment (SEA) of a revamped project, and called it the Rodoanel Programme. However, the SEA report failed to satisfactorily take account of significant strategic issues. Among these, the highway potential effect of inducing urban sprawl over water protection zones is the most critical issue, as it emerged later as a hurdle to project licensing. Conclusion is that, particularly where no agreed-upon framework for SEA exists, when vertical tiering with downstream project EIA is sought, then a careful scoping of strategic issues is more than necessary. If an agreement on 'what is strategic' is not reached and not recognized by influential stakeholders, then the unsettled conflicts will be transferred to project EIA. In such a context, SEA will have added another loop to the usually long road to project approval

  15. Urbanisation processes in Slovenia and their effects on urban networks

    Directory of Open Access Journals (Sweden)

    Kaliopa Dimitrovska Andrews

    2000-01-01

    Full Text Available The article presents processes of changes in the structure of settlement systems in Europe and Slovenia. Hypotheses that have to be given adequate respect as starting points in the development of the urban system follow particular levels of discourse, from the European and national, regional level to the local level. Thus directing urbanisation is different on different levels. Two examples of directing urbanisation processes on the local level are presented, for the functional urban region of Ljubljana and the municipality of Domžale. In conclusion ideas about measures and instruments for achieving urban development policies are shown.

  16. Decisions of hypermarkets location in dense urban area – effects on streets network congestion in the Bucharest case

    Directory of Open Access Journals (Sweden)

    Eugen ROSCA

    2008-01-01

    Full Text Available The paper represents some partial results of the research carried out by the Transportation, Traffic and Logistics Department - University POLITEHNICA of Bucharest, funded by the Romanian Ministry of Research and Education through the National University Research Council. In this paper we provide: a brief description of the interrelation between the life style changes of Romanian people during the last decades and the car traffic congestion in large cities; the streets network modelling of a radial-circular urban structure (the characteristic of a historically developed city as Bucharest city is, in case of car traffic congestion; the assessment model of the additional car traffic congestion for certain locations with large attractivity. Having an important effect on the entire lifestyle of urban people, the decision of a hypermarket location might be a complex one, taking into consideration the new leisure and shopping tendencies but also the additional car traffic congestion caused by the chosen location.

  17. A New Era for Urban Modelling

    OpenAIRE

    Pumain , Denise

    1994-01-01

    International audience; In the last two decades, several interesting innovations have appeared in the field of urban research. New paradigms such as the dynamics of open systems, self-organization, synergetics, chaos, evolution, were recognized as conveying fruitful analogies for urban theory. New types of modeling were investigated, as sets of non-linear differential equations for spatial systems, cellular automata, multi-agents models, fractal growth, neural networks, evolutionary models… H...

  18. Governance of urban transitions: towards sustainable resource efficient urban infrastructures

    Science.gov (United States)

    Swilling, Mark; Hajer, Maarten

    2017-12-01

    The transition to sustainable resource efficient cities calls for new governance arrangements. The awareness that the doubling of the global urban population will result in unsustainable levels of demand for natural resources requires changes in the existing socio-technical systems. Domestic material consumption could go up from 40 billion tons in 2010, to 89 billion tons by 2050. While there are a number of socio-technical alternatives that could result in significant improvements in the resource efficiency of urban systems in developed and developing countries (specifically bus-rapid transit, district energy systems and green buildings), we need to rethink the urban governance arrangements to get to this alternative pathway. We note modes of urban governance have changed over the past century as economic and urban development paradigms have shifted at the national and global levels. This time round we identify cities as leading actors in the transition to more sustainable modes of production and consumption as articulated in the Sustainable Development Goals. This has resulted in a surge of urban experimentation across all world regions, both North and South. Building on this empirically observable trend we suggest this can also be seen as a building block of a new urban governance paradigm. An ‘entrepreneurial urban governance’ is proposed that envisages an active and goal-setting role for the state, but in ways that allows broader coalitions of urban ‘agents of change’ to emerge. This entrepreneurial urban governance fosters and promotes experimentation rather than suppressing the myriad of such initiatives across the globe, and connects to global city networks for systemic learning between cities. Experimentation needs to result in a contextually appropriate balance between economic, social, technological and sustainable development. A full and detailed elaboration of the arguments and sources for this article can be found in chapter 6 of Swilling M et

  19. Long-term urban carbon dioxide observations reveal spatial and temporal dynamics related to urban characteristics and growth.

    Science.gov (United States)

    Mitchell, Logan E; Lin, John C; Bowling, David R; Pataki, Diane E; Strong, Courtenay; Schauer, Andrew J; Bares, Ryan; Bush, Susan E; Stephens, Britton B; Mendoza, Daniel; Mallia, Derek; Holland, Lacey; Gurney, Kevin R; Ehleringer, James R

    2018-03-20

    Cities are concentrated areas of CO 2 emissions and have become the foci of policies for mitigation actions. However, atmospheric measurement networks suitable for evaluating urban emissions over time are scarce. Here we present a unique long-term (decadal) record of CO 2 mole fractions from five sites across Utah's metropolitan Salt Lake Valley. We examine "excess" CO 2 above background conditions resulting from local emissions and meteorological conditions. We ascribe CO 2 trends to changes in emissions, since we did not find long-term trends in atmospheric mixing proxies. Three contrasting CO 2 trends emerged across urban types: negative trends at a residential-industrial site, positive trends at a site surrounded by rapid suburban growth, and relatively constant CO 2 over time at multiple sites in the established, residential, and commercial urban core. Analysis of population within the atmospheric footprints of the different sites reveals approximately equal increases in population influencing the observed CO 2 , implying a nonlinear relationship with CO 2 emissions: Population growth in rural areas that experienced suburban development was associated with increasing emissions while population growth in the developed urban core was associated with stable emissions. Four state-of-the-art global-scale emission inventories also have a nonlinear relationship with population density across the city; however, in contrast to our observations, they all have nearly constant emissions over time. Our results indicate that decadal scale changes in urban CO 2 emissions are detectable through monitoring networks and constitute a valuable approach to evaluate emission inventories and studies of urban carbon cycles.

  20. Long-term urban carbon dioxide observations reveal spatial and temporal dynamics related to urban characteristics and growth

    Science.gov (United States)

    Mitchell, Logan E.; Lin, John C.; Bowling, David R.; Pataki, Diane E.; Strong, Courtenay; Schauer, Andrew J.; Bares, Ryan; Bush, Susan E.; Stephens, Britton B.; Mendoza, Daniel; Mallia, Derek; Holland, Lacey; Gurney, Kevin R.; Ehleringer, James R.

    2018-03-01

    Cities are concentrated areas of CO2 emissions and have become the foci of policies for mitigation actions. However, atmospheric measurement networks suitable for evaluating urban emissions over time are scarce. Here we present a unique long-term (decadal) record of CO2 mole fractions from five sites across Utah’s metropolitan Salt Lake Valley. We examine “excess” CO2 above background conditions resulting from local emissions and meteorological conditions. We ascribe CO2 trends to changes in emissions, since we did not find long-term trends in atmospheric mixing proxies. Three contrasting CO2 trends emerged across urban types: negative trends at a residential-industrial site, positive trends at a site surrounded by rapid suburban growth, and relatively constant CO2 over time at multiple sites in the established, residential, and commercial urban core. Analysis of population within the atmospheric footprints of the different sites reveals approximately equal increases in population influencing the observed CO2, implying a nonlinear relationship with CO2 emissions: Population growth in rural areas that experienced suburban development was associated with increasing emissions while population growth in the developed urban core was associated with stable emissions. Four state-of-the-art global-scale emission inventories also have a nonlinear relationship with population density across the city; however, in contrast to our observations, they all have nearly constant emissions over time. Our results indicate that decadal scale changes in urban CO2 emissions are detectable through monitoring networks and constitute a valuable approach to evaluate emission inventories and studies of urban carbon cycles.

  1. URBAN EXPANSION AND LOSS OF AGRICULTURAL LAND IN ...

    African Journals Online (AJOL)

    Dr Osondu

    1987-09-23

    Sep 23, 1987 ... study and to assess its influence on agricultural lands. ... average annual rates of urban growth in Uyo Urban area were 4.48%, 0.56% between 1978/1988, 8.57% .... region (Woodwell et, al; 1984 and Williams, ... The reverse was the case with agricultural land. ... cohesive, organized network of vegetable.

  2. Outer Synchronization between Two Coupled Complex Networks and Its Application in Public Traffic Supernetwork

    Directory of Open Access Journals (Sweden)

    Wen-ju Du

    2016-01-01

    Full Text Available The paper presents a new urban public traffic supernetwork model by using the existing bus network modeling method, consisting of the conventional bus traffic network and the urban rail traffic network. We investigate the synchronization problem of urban public traffic supernetwork model by using the coupled complex network’s outer synchronization theory. Analytical and numerical simulations are given to illustrate the impact of traffic dispatching frequency and traffic lines optimization to the urban public traffic supernetwork balance.

  3. Traffic Command Gesture Recognition for Virtual Urban Scenes Based on a Spatiotemporal Convolution Neural Network

    Directory of Open Access Journals (Sweden)

    Chunyong Ma

    2018-01-01

    Full Text Available Intelligent recognition of traffic police command gestures increases authenticity and interactivity in virtual urban scenes. To actualize real-time traffic gesture recognition, a novel spatiotemporal convolution neural network (ST-CNN model is presented. We utilized Kinect 2.0 to construct a traffic police command gesture skeleton (TPCGS dataset collected from 10 volunteers. Subsequently, convolution operations on the locational change of each skeletal point were performed to extract temporal features, analyze the relative positions of skeletal points, and extract spatial features. After temporal and spatial features based on the three-dimensional positional information of traffic police skeleton points were extracted, the ST-CNN model classified positional information into eight types of Chinese traffic police gestures. The test accuracy of the ST-CNN model was 96.67%. In addition, a virtual urban traffic scene in which real-time command tests were carried out was set up, and a real-time test accuracy rate of 93.0% was achieved. The proposed ST-CNN model ensured a high level of accuracy and robustness. The ST-CNN model recognized traffic command gestures, and such recognition was found to control vehicles in virtual traffic environments, which enriches the interactive mode of the virtual city scene. Traffic command gesture recognition contributes to smart city construction.

  4. Catchment Dispersion Mechanisms in an Urban Context

    Science.gov (United States)

    Gironas, J. A.; Mejia, A.; Rossel, F.; Rinaldo, A.; Rodriguez, F.

    2014-12-01

    Dispersion mechanisms have been examined in-depth in natural catchments in previous studies. However, these dispersion mechanisms have been studied little in urban catchments, where artificial transport elements and morphological arrangements are expected to modify travel times and mobilize excess rainfall from spatially distributed impervious sites. Thus, these features can modify the variance of the catchment's travel times and hence the total dispersion. This work quantifies the dispersion mechanisms in an urban catchment using the theory of transport by travel times as represented by the Urban Morpho-climatic Instantaneous Unit Hydrograph (U-McIUH) model. This model computes travel times based on kinematic wave theory and accounts explicitly for the path heterogeneities and altered connectivity patterns characteristic of an urban drainage network. The analysis is illustrated using the Aubinière urban catchment (France) as a case study. We found that kinematic dispersion is dominant for small rainfall intensities, whereas geomorphologic dispersion becomes more dominant for larger intensities. The total dispersion scales with the drainage area in a power law fashion. The kinematic dispersion is dominant across spatial scales up to a threshold of approximately 2-3 km2, after which the geomorphologic dispersion becomes more dominant. Overall, overland flow is responsible for most of the dispersion, while conduits tend to counteract the increase of the geomorphologic dispersion with a negative kinematic dispersion. Further studies with other catchments are needed to assess whether the latter is a general feature of urban drainage networks.

  5. Geomorphic Assessment of Floods within the Urban Environment of ...

    African Journals Online (AJOL)

    This study examined urban geomorphic conditions that lead to flooding in urban areas of ... the elimination of vegetation cover as well as deficient drainage networks ... Department of Geography & Resource Development, University of Ghana, Legon, .... A number of case studies from different parts of the world dealing.

  6. An hybrid and non-modern approach to urban studies

    Directory of Open Access Journals (Sweden)

    Marc Grau i Solés

    2012-03-01

    Full Text Available This article draws upon the so-called Forat de la Vergonya urban controversy and the urban transformation process of a neighborhood in Barcelona: el Casc Antic. Drawing on inputs from Actor-Network Theory (ANT, the city is explored as a multiple urban assemblage. Besides, we analyze the dichotomous nature of the modern notion of politics. Especially, the role of object-subject dichotomy is explored. Through the analysis of citizen participation opportunities we propose a new hybrid notion of citizen participation and urban policy.

  7. Adaptive governance to promote ecosystem services in urban green spaces

    Science.gov (United States)

    Managing urban green space as part of an ongoing social-ecological transformationposes novel governance issues, particularly in post-industrial settings. Urban green spaces operate as small-scale nodes in larger networks of ecological reserves that provide and maintain key ecosys...

  8. SmartScapes : Big data and urban informatics for performative cities

    NARCIS (Netherlands)

    Psyllidis, A.

    2013-01-01

    The distribution of sensor networks throughout the contemporary urban environment together with advances in mobile and web-related technologies, create new opportunities for practice and research in Urbanism. Digitally-driven systems and devices provide immense amounts of real-time data streams,

  9. A convergent model for distributed processing of Big Sensor Data in urban engineering networks

    Science.gov (United States)

    Parygin, D. S.; Finogeev, A. G.; Kamaev, V. A.; Finogeev, A. A.; Gnedkova, E. P.; Tyukov, A. P.

    2017-01-01

    The problems of development and research of a convergent model of the grid, cloud, fog and mobile computing for analytical Big Sensor Data processing are reviewed. The model is meant to create monitoring systems of spatially distributed objects of urban engineering networks and processes. The proposed approach is the convergence model of the distributed data processing organization. The fog computing model is used for the processing and aggregation of sensor data at the network nodes and/or industrial controllers. The program agents are loaded to perform computing tasks for the primary processing and data aggregation. The grid and the cloud computing models are used for integral indicators mining and accumulating. A computing cluster has a three-tier architecture, which includes the main server at the first level, a cluster of SCADA system servers at the second level, a lot of GPU video cards with the support for the Compute Unified Device Architecture at the third level. The mobile computing model is applied to visualize the results of intellectual analysis with the elements of augmented reality and geo-information technologies. The integrated indicators are transferred to the data center for accumulation in a multidimensional storage for the purpose of data mining and knowledge gaining.

  10. Urban Floods Adaptation and Sustainable Drainage Measures

    Directory of Open Access Journals (Sweden)

    Helena M. Ramos

    2017-11-01

    Full Text Available Sustainability is crucial to the urban zones, especially related to the water management, which is vulnerable to flood occurrence. This research applies the procedure contemplated by the Soil Conservation Service (SCS to determine the generated volumes when the impervious areas can exceed the drainage capacity of existing pluvial water networks. Several computational simulations were developed for the current scenario of an existing basin in Lisbon. Using CivilStorm software from Bentley Systems (Bentley EMEA, Bentley Systems International Limited, Dublin, Ireland, it enabled the evaluation of the volumes of flood peaks and the hydraulic behavior of a small hydrographic basin in the continuation of an urbanization process, considering the modification of its superficial impervious parts and the growth of the urbanized area. Several measures are suggested to solve the limited capacity of the existing drainage system. This study analyzes the efficiency of the application of constructive measures, pondering the viability of their effectiveness, individually and combined. The option that best minimizes the effects of the urbanization is the combination of different structural measures, in particular retention ponds, storage blocks, ditches and specific drainage interventions in some parts of the network.

  11. Urban sustainability : complex interactions and the measurement of risk

    Directory of Open Access Journals (Sweden)

    Lidia Diappi

    1999-05-01

    Full Text Available This paper focuses on the concept of asustainable city and its theoretical implications for the urban system. Urban sustainability is based on positive interactions among three different urban sub-systems : social, economic and physical, where social well-being coexists with economic development and environmental quality. This utopian scenario doesn’t appear. Affluent economy is often associated with poverty and criminality, labour variety and urban efficiency coexist with pollution and congestion. The research subject is the analysis of local risk and opportunity conditions, based on the application of a special definition of risk elaborated and made operative with the production of a set of maps representing the multidimensional facets of spatial organisation in urban sustainability. The interactions among the economic/social and environmental systems are complex and unpredictable and present the opportunity for a new methodology of scientific investigation : the connectionistic approach, processed by Self-Reflexive Neural Networks (SRNN. These Networks are a useful instrument of investigation and analogic questioning of the Data Base. Once the SRNN has learned the structure of the weights from the DB, by querying the network with the maximization or minimization of specific groups of attributes, it is possible to read the related properties and to rank the areas. The survey scale assumed by the research is purposefully aimed at the micro-scale and concerns the Municipality of Milan which is spatially divided into 144 zones.

  12. Research on Access Zone Luminance of Expressway Tunnel in Southwest Mountainous Areas of Zhejiang Province%浙西南山区高速公路隧道洞外亮度研究

    Institute of Scientific and Technical Information of China (English)

    涂耘; 王少飞; 侯伶; 张琦; 蔡坚健; 谢晓辉; 刘琦; 潘永杰

    2012-01-01

    The shortcomings for traditional measurement method of L20(S)are analyzed,and a novel measurement method of L20(S)based digital technology is introduced,making large-scale and high efficiency measurement is possible. Using this method and means test lighting environment of road tunnels in Jin-Li-Wen and Liang-Long Expressway,and recommended value of L20(S)in southwest mountainous areas of Zhejiang Province is put forward,it can provide the reference for energy-saving operation and transformation design of road tunnel lighting system. Based on landscape theory,measures are also proposed to reduce light for access zone that consistent with "environmentally friendly"designing philosophy of expressway tunnel in mountainous areas. This research result has the better economic and social and ecological benefits that can be fully application in practical engineering.%在分析传统公路隧道洞外亮度L20(S)测算方法不足的基础上,介绍一种基于数码技术的公路隧道洞外亮度L20(S)测试方法,使得大规模、高效率地实测公路隧道洞外亮度L20(S)成为可能.采用上述方法和手段对金丽温、两龙高速公路隧道洞口光环境进行实测,提出浙西南山区高速公路隧道洞外亮度L20(S)建议值,可供高速公路隧道照明系统节能运营及改造设计时参考.基于环境景观理论,提出符合“环境友好型”山区高速公路隧道设计理念的接近段减光措施.研究成果具有较好的经济效益、社会效益和生态效益,可在实际工程中全面推广应用.

  13. Urban Malaria: Understanding its Epidemiology, Ecology, and Transmission across Seven Diverse ICEMR Network Sites

    Science.gov (United States)

    Wilson, Mark L.; Krogstad, Donald J.; Arinaitwe, Emmanuel; Arevalo-Herrera, Myriam; Chery, Laura; Ferreira, Marcelo U.; Ndiaye, Daouda; Mathanga, Don P.; Eapen, Alex

    2015-01-01

    A major public health question is whether urbanization will transform malaria from a rural to an urban disease. However, differences about definitions of urban settings, urban malaria, and whether malaria control should differ between rural and urban areas complicate both the analysis of available data and the development of intervention strategies. This report examines the approach of the International Centers of Excellence for Malaria Research (ICEMR) to urban malaria in Brazil, Colombia, India (Chennai and Goa), Malawi, Senegal, and Uganda. Its major theme is the need to determine whether cases diagnosed in urban areas were imported from surrounding rural areas or resulted from transmission within the urban area. If infections are being acquired within urban areas, malaria control measures must be targeted within those urban areas to be effective. Conversely, if malaria cases are being imported from rural areas, control measures must be directed at vectors, breeding sites, and infected humans in those rural areas. Similar interventions must be directed differently if infections were acquired within urban areas. The hypothesis underlying the ICEMR approach to urban malaria is that optimal control of urban malaria depends on accurate epidemiologic and entomologic information about transmission. PMID:26259941

  14. URBAN-NET: A Network-based Infrastructure Monitoring and Analysis System for Emergency Management and Public Safety

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangkeun (Matt) [ORNL; Chen, Liangzhe [ORNL; Duan, Sisi [ORNL; Chinthavali, Supriya [ORNL; Shankar, Mallikarjun (Arjun) [ORNL; Prakash, B. Aditya [Virginia Tech, Blacksburg, VA

    2016-01-01

    Abstract Critical Infrastructures (CIs) such as energy, water, and transportation are complex networks that are crucial for sustaining day-to-day commodity flows vital to national security, economic stability, and public safety. The nature of these CIs is such that failures caused by an extreme weather event or a man-made incident can trigger widespread cascading failures, sending ripple effects at regional or even national scales. To minimize such effects, it is critical for emergency responders to identify existing or potential vulnerabilities within CIs during such stressor events in a systematic and quantifiable manner and take appropriate mitigating actions. We present here a novel critical infrastructure monitoring and analysis system named URBAN-NET. The system includes a software stack and tools for monitoring CIs, pre-processing data, interconnecting multiple CI datasets as a heterogeneous network, identifying vulnerabilities through graph-based topological analysis, and predicting consequences based on what-if simulations along with visualization. As a proof-of-concept, we present several case studies to show the capabilities of our system. We also discuss remaining challenges and future work.

  15. Establishing an air pollution monitoring network for intra-urban population exposure assessment : a location-allocation approach

    Energy Technology Data Exchange (ETDEWEB)

    Kanaroglou, P.S. [McMaster Univ., Hamilton, ON (Canada). School of Geography and Geology; Jerrett, M.; Beckerman, B.; Arain, M.A. [McMaster Univ., Hamilton, ON (Canada). School of Geography and Geology]|[McMaster Univ., Hamilton, ON (Canada). McMaster Inst. of Environment and Health; Morrison, J. [Carleton Univ., Ottawa, ON (Canada). School of Computer Science; Gilbert, N.L. [Health Canada, Ottawa, ON (Canada). Air Health Effects Div; Brook, J.R. [Meteorological Service of Canada, Toronto, ON (Canada)

    2004-10-01

    A study was conducted to assess the relation between traffic-generated air pollution and health reactions ranging from childhood asthma to mortality from lung cancer. In particular, it developed a formal method of optimally locating a dense network of air pollution monitoring stations in order to derive an exposure assessment model based on the data obtained from the monitoring stations and related land use, population and biophysical information. The method for determining the locations of 100 nitrogen dioxide monitors in Toronto, Ontario focused on land use, transportation infrastructure and the distribution of at-risk populations. The exposure assessment produced reasonable estimates at the intra-urban scale. This method for locating air pollution monitors effectively maximizes sampling coverage in relation to important socio-demographic characteristics and likely pollution variability. The location-allocation approach integrates many variables into the demand surface to reconfigure a monitoring network and is especially useful for measuring traffic pollutants with fine-scale spatial variability. The method also shows great promise for improving the assessment of exposure to ambient air pollution in epidemiologic studies. 19 refs., 3 tabs., 4 figs.

  16. Modelling Altitude Information in Two-Dimensional Traffic Networks for Electric Mobility Simulation

    Directory of Open Access Journals (Sweden)

    Diogo Santos

    2016-06-01

    Full Text Available Elevation data is important for electric vehicle simulation. However, traffic simulators are often two-dimensional and do not offer the capability of modelling urban networks taking elevation into account. Specifically, SUMO - Simulation of Urban Mobility, a popular microscopic traffic simulator, relies on networks previously modelled with elevation data as to provide this information during simulations. This work tackles the problem of adding elevation data to urban network models - particularly for the case of the Porto urban network, in Portugal. With this goal in mind, a comparison between different altitude information retrieval approaches is made and a simple tool to annotate network models with altitude data is proposed. The work starts by describing the methodological approach followed during research and development, then describing and analysing its main findings. This description includes an in-depth explanation of the proposed tool. Lastly, this work reviews some related work to the subject.

  17. Urban Malaria: Understanding its Epidemiology, Ecology, and Transmission Across Seven Diverse ICEMR Network Sites.

    Science.gov (United States)

    Wilson, Mark L; Krogstad, Donald J; Arinaitwe, Emmanuel; Arevalo-Herrera, Myriam; Chery, Laura; Ferreira, Marcelo U; Ndiaye, Daouda; Mathanga, Don P; Eapen, Alex

    2015-09-01

    A major public health question is whether urbanization will transform malaria from a rural to an urban disease. However, differences about definitions of urban settings, urban malaria, and whether malaria control should differ between rural and urban areas complicate both the analysis of available data and the development of intervention strategies. This report examines the approach of the International Centers of Excellence for Malaria Research (ICEMR) to urban malaria in Brazil, Colombia, India (Chennai and Goa), Malawi, Senegal, and Uganda. Its major theme is the need to determine whether cases diagnosed in urban areas were imported from surrounding rural areas or resulted from transmission within the urban area. If infections are being acquired within urban areas, malaria control measures must be targeted within those urban areas to be effective. Conversely, if malaria cases are being imported from rural areas, control measures must be directed at vectors, breeding sites, and infected humans in those rural areas. Similar interventions must be directed differently if infections were acquired within urban areas. The hypothesis underlying the ICEMR approach to urban malaria is that optimal control of urban malaria depends on accurate epidemiologic and entomologic information about transmission. © The American Society of Tropical Medicine and Hygiene.

  18. Generalized Cartographic and Simultaneous Representation of Utility Networks for Decision-Support Systems and Crisis Management in Urban Environments

    Science.gov (United States)

    Becker, T.; König, G.

    2015-10-01

    Cartographic visualizations of crises are used to create a Common Operational Picture (COP) and enforce Situational Awareness by presenting relevant information to the involved actors. As nearly all crises affect geospatial entities, geo-data representations have to support location-specific analysis throughout the decision-making process. Meaningful cartographic presentation is needed for coordinating the activities of crisis manager in a highly dynamic situation, since operators' attention span and their spatial memories are limiting factors during the perception and interpretation process. Situational Awareness of operators in conjunction with a COP are key aspects in decision-making process and essential for making well thought-out and appropriate decisions. Considering utility networks as one of the most complex and particularly frequent required systems in urban environment, meaningful cartographic presentation of multiple utility networks with respect to disaster management do not exist. Therefore, an optimized visualization of utility infrastructure for emergency response procedures is proposed. The article will describe a conceptual approach on how to simplify, aggregate, and visualize multiple utility networks and their components to meet the requirements of the decision-making process and to support Situational Awareness.

  19. Modeling Urban Collaborative Growth Dynamics Using a Multiscale Simulation Model for the Wuhan Urban Agglomeration Area, China

    Directory of Open Access Journals (Sweden)

    Yan Yu

    2018-05-01

    Full Text Available Urban agglomeration has become the predominant form of urbanization in China. In this process, spatial interaction evidently played a significant role in promoting the collaborative development of these correlated cities. The traditional urban model’s focus on individual cities should be transformed to an urban system model. In this study, a multi-scale simulation model has been proposed to simulate the agglomeration development process of the Wuhan urban agglomeration area by embedding the multi-scale spatial interaction into the transition rule system of cellular automata (CA. A system dynamic model was used to predict the demand for new urban land at an aggregated urban agglomeration area scale. A data field approach was adopted to measuring the interaction of intercity at city scale. Neighborhood interaction was interpreted with a logistic regression method at the land parcel scale. Land use data from 1995, 2005, and 2015 were used to calibrate and evaluate the model. The simulation results show that there has been continuing urban growth in the Wuhan urban agglomeration area from 1995 to 2020. Although extension-sprawl was the predominant pattern of urban spatial expansion, the trend of extensive growth to intensive growth is clear during the entire period. The spatial interaction among these cities has been reinforced, which guided the collaborative development and formed the regional urban system network.

  20. Ecological sustainability and urban greenspace

    DEFF Research Database (Denmark)

    Attwell, K.(red.); Beer, A.(red.)

    . The background of the network was to join forces in support of the developing scientific and political interest in urban greenstructure. The point of departure of the seminar was the local approach to sustainable greenspace planning and management and the special focus was the potential role of greenspace...... in relation to urban metabolism and biodiversity. The report includes contributions presented at the seminar. The Danish papers are on the town of Ringkøbing, which was the location of the seminar and the subject of the seminar workshop....

  1. Renewal or rehabilitation of urban river and stream corridors

    Directory of Open Access Journals (Sweden)

    Matjaž Mikoš

    2001-01-01

    Full Text Available Analyses of the morphological state of urban streams and rivers in the Municipality of Ljubljana and research concerning the hydrographical network show that the condition of their morphological preservation is alarming. Efforts put in the new spatial development concept, guidelines and proposals for urban rehabilitation are therefore also an opportunity for rehabilitation measures on the municipal hydrographical network. Adequate care should be given to their improved morphological state even because of the recently adopted European framework water directive (annex 5, that after a certain period demands such a status of surface water in signatory countries.

  2. Influence of landscape mosaic on streamflow of a peri-urban catchment under Mediterranean climate

    Science.gov (United States)

    Ferreira, Carla; Walsh, Rory; Ferreira, António

    2017-04-01

    Peri-urban areas tend to be characterized by patchy landscape mosaics of different land-uses. Although the impact of land-use changes on catchment hydrology have been widely investigated, the impact of mixed land-use patterns on the streamflow of peri-urban areas is still poorly understood. This study aims to (i) explore and quantify streamflow delivery from sub-catchments characterized by distinct landscape mosaics; (ii) assess the impact of different urbanization styles on hydrograph properties; and (iii) explore the influence of urbanization type on flow connectivity and stream discharge. The study was carried out in Ribeira dos Covões, a small (6.2km2) peri-urban catchment in central Portugal. The climate is Mediterranean, with a mean annual rainfall of 892mm. Catchment geology comprises sandstone (56%), limestone (41%) and alluvial deposits (3%). Soils developed on sandstone are generally deep (>3m) Fluvisols and Podsols, whereas on limestone the Leptic Cambisols are typically shallow (blocks and of high population density (9900 inhabitants km-2). The study uses hydrological data recorded over three hydrological years, starting in November 2010, in a monitoring network comprising eight streamflow gauging stations (instrumented with water level recorders) and five rainfall gauges. The gauging stations provide information on the discharge response to rainstorms of the catchment outlet and upstream sub-catchments of different size, urban pattern (in terms of percentage urban land-use and impervious area, distance to the stream network, and storm water management), and lithology (either sandstone or limestone). Annual storm runoff coefficients were lowest (13.7%) in catchments dominated by forest (>80%) and greatest (17.3-17.6%) in the most urbanized sub-catchments (49-53% urban). Impervious area seems to control streamflow particularly during dry periods. Winter runoff (streamflow per unit area) was 2-4 times higher than summer runoff in highly urbanized areas

  3. Deadlocks and breakthroughs in urban renewal : A network analysis in Amsterdam

    NARCIS (Netherlands)

    Haffner, M.E.A.; Elsinga, M.

    2009-01-01

    Urban renewal in the Netherlands has become a matter of ‘networking’. Housing associations, Dutch social landlords, became financially independent in the 1990s and have a responsibility in urban renewal. It is a joint responsibility in which local authority, social landlord and tenants are dependent

  4. From cities and towns to urban networks in Germany – intra regional competition versus regional co-operation and inter regional competitiveness

    Directory of Open Access Journals (Sweden)

    Bernhard Mueller

    2000-01-01

    Full Text Available For many decades of the 20th century particular cities and towns were understood as integral parts of national and international urban systems. For many years the theory on central places and hierarchy of central places, first developed by Christaller and amended by Loesch, had a decisive influence on spatial research and regional development policies with guiding principles for urbanisation and the development of settlement patterns. However it is becoming ever more evident, that the planned effects of concepts for harmonising intra- and inter-regional differences were not reached. Moreover, inter-regional competition between neighbouring municipalities, as well as modern life styles and residential choices have caused the emergence of new settlement structures with dispersed spatial patterns and string functional ties. It is also true, that urban networking isn’t an easy task and that it inherently carries numerous obstacles.

  5. Controlling Urban Sprawl with Integrated Approach of Space-Transport Development Strategies

    NARCIS (Netherlands)

    Ambarwati, L.; Verhaeghe, R.; Pel, A.J.; Van Arem, B.

    2014-01-01

    Urban sprawl phenomenon has been a huge issue since 20th century characterized by a rapid and unbalanced settlement development with transportation network particularly in a suburban area. The improvement of public transport system is a major requirement to minimize urban sprawl. Academic

  6. Refueling availability for alternative fuel vehicle markets: Sufficient urban station coverage

    International Nuclear Information System (INIS)

    Melaina, Marc; Bremson, Joel

    2008-01-01

    Alternative fuel vehicles can play an important role in addressing the challenges of climate change, energy security, urban air pollution and the continued growth in demand for transportation services. The successful commercialization of alternative fuels for vehicles is contingent upon a number of factors, including vehicle cost and performance. Among fuel infrastructure issues, adequate refueling availability is one of the most fundamental to successful commercialization. A commonly cited source reports 164,300 refueling stations in operation nationwide. However, from the perspective of refueling availability, this nationwide count tends to overstate the number of stations required to support the widespread deployment of alternative fuel vehicles. In terms of spatial distribution, the existing gasoline station networks in many urban areas are more than sufficient. We characterize a sufficient level of urban coverage based upon a subset of cities served by relatively low-density station networks, and estimate that some 51,000 urban stations would be required to provide this sufficient level of coverage to all major urban areas, 33 percent less than our estimate of total urban stations. This improved characterization will be useful for engineering, economic and policy analyses. (author)

  7. Runoff Modelling in Urban Storm Drainage by Neural Networks

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Brorsen, Michael; Schaarup-Jensen, Kjeld

    1995-01-01

    A neural network is used to simulate folw and water levels in a sewer system. The calibration of th neural network is based on a few measured events and the network is validated against measureed events as well as flow simulated with the MOUSE model (Lindberg and Joergensen, 1986). The neural...... network is used to compute flow or water level at selected points in the sewer system, and to forecast the flow from a small residential area. The main advantages of the neural network are the build-in self calibration procedure and high speed performance, but the neural network cannot be used to extract...... knowledge of the runoff process. The neural network was found to simulate 150 times faster than e.g. the MOUSE model....

  8. Reconfiguring Urban Sustainability Transitions, Analysing Multiplicity

    Directory of Open Access Journals (Sweden)

    Mike Hodson

    2017-02-01

    Full Text Available Cities, and the networked infrastructures that sustain urban life, are seen as crucial sites for creating more sustainable futures. Yet, although there are many plans, the realisation of sustainable urban infrastructures on the ground is uneven. To develop better ways of understanding why this is the case, the paper makes a conceptual contribution by engaging with current understanding of urban sustainability transitions, using urban sustainable mobility as a reference point. It extends these insights to argue that urban transitions are not about technological or social innovation per se, but about how multiple innovations are experimented with, combined and reconfigured in existing urban contexts and how such processes are governed. There are potentially many ways in which urban sustainable mobility can be reconfigured contextually. Innovation is in the particular form of reconfiguration rather than individual technologies. To make analytical sense of this multiplicity, a preliminary framework is developed that offers the potential to think about urban transitions as contextual and reconfigurational. We argue that there is a need to embrace multiplicity and to understand its relationships to forms of reconfiguration, through empirical exploration and further theoretical and conceptual development. The preliminary framework is a contribution to doing so and we set out future directions for research.

  9. The modeling of attraction characteristics regarding passenger flow in urban rail transit network based on field theory.

    Science.gov (United States)

    Li, Man; Wang, Yanhui; Jia, Limin

    2017-01-01

    Aimed at the complicated problems of attraction characteristics regarding passenger flow in urban rail transit network, the concept of the gravity field of passenger flow is proposed in this paper. We establish the computation methods of field strength and potential energy to reveal the potential attraction relationship among stations from the perspective of the collection and distribution of passenger flow and the topology of network. As for the computation methods of field strength, an optimum path concept is proposed to define betweenness centrality parameter. Regarding the computation of potential energy, Compound Simpson's Rule Formula is applied to get a solution to the function. Taking No. 10 Beijing Subway as a practical example, an analysis of simulation and verification is conducted, and the results shows in the following ways. Firstly, the bigger field strength value between two stations is, the stronger passenger flow attraction is, and the greater probability of the formation of the largest passenger flow of section is. Secondly, there is the greatest passenger flow volume and circulation capacity between two zones of high potential energy.

  10. The modeling of attraction characteristics regarding passenger flow in urban rail transit network based on field theory.

    Directory of Open Access Journals (Sweden)

    Man Li

    Full Text Available Aimed at the complicated problems of attraction characteristics regarding passenger flow in urban rail transit network, the concept of the gravity field of passenger flow is proposed in this paper. We establish the computation methods of field strength and potential energy to reveal the potential attraction relationship among stations from the perspective of the collection and distribution of passenger flow and the topology of network. As for the computation methods of field strength, an optimum path concept is proposed to define betweenness centrality parameter. Regarding the computation of potential energy, Compound Simpson's Rule Formula is applied to get a solution to the function. Taking No. 10 Beijing Subway as a practical example, an analysis of simulation and verification is conducted, and the results shows in the following ways. Firstly, the bigger field strength value between two stations is, the stronger passenger flow attraction is, and the greater probability of the formation of the largest passenger flow of section is. Secondly, there is the greatest passenger flow volume and circulation capacity between two zones of high potential energy.

  11. Vulnerability of complex networks

    Science.gov (United States)

    Mishkovski, Igor; Biey, Mario; Kocarev, Ljupco

    2011-01-01

    We consider normalized average edge betweenness of a network as a metric of network vulnerability. We suggest that normalized average edge betweenness together with is relative difference when certain number of nodes and/or edges are removed from the network is a measure of network vulnerability, called vulnerability index. Vulnerability index is calculated for four synthetic networks: Erdős-Rényi (ER) random networks, Barabási-Albert (BA) model of scale-free networks, Watts-Strogatz (WS) model of small-world networks, and geometric random networks. Real-world networks for which vulnerability index is calculated include: two human brain networks, three urban networks, one collaboration network, and two power grid networks. We find that WS model of small-world networks and biological networks (human brain networks) are the most robust networks among all networks studied in the paper.

  12. Equity, sustainability and governance in urban settings.

    Science.gov (United States)

    Rice, Marilyn; Hancock, Trevor

    2016-03-01

    In this commentary the urban setting is explored from the perspective of ecological sustainability and social equity. Urban-related issues are highlighted related to social inequality, deficits in urban infrastructures, behavior-related illnesses and risks, global ecological changes, and urban sprawl. Approaches to addressing these issues are described from the perspective of urban governance, urban planning and design, social determinants of health, health promotion, and personal and community empowerment. Examples of successful strategies are provided from Latin America, including using participatory instruments (assessments, evaluation, participatory budgeting, etc.), establishing intersectoral committees, increasing participation of civil society organizations, and developing virtual forums and networks to channel participatory and collaborative processes. A way forward is proposed, using the urban setting to show the imperative of creating intersectoral policies and programs that produce environments that are both healthy and sustainable. It will be important to include new forms of social participation and use social media to facilitate citizen decision-making and active participation of all sectors of society, especially excluded groups. © The Author(s) 2015.

  13. Locating Automated External Defibrillators in a Complicated Urban Environment Considering a Pedestrian-Accessible Network that Focuses on Out-of-Hospital Cardiac Arrests

    Directory of Open Access Journals (Sweden)

    Pil Kwon

    2017-02-01

    Full Text Available Automated external defibrillators (AEDs are portable devices that defibrillate and diagnose sudden-cardiac-arrest patients. Therefore, AEDs are widely installed in public places such as airports, schools, sport complexes, etc., and the installation of AEDs is required by law in these places. However, despite their usefulness, AEDs are mostly installed indoors with limited coverage outdoors. Hence, this study conducts research in the placement of AEDs in outdoor locations. This study considers a complicated urban environment using a pedestrian network dataset and network barriers. We draw on the Teitz and Bart’s (1968 heuristic method that was built in the location-allocation solver in ArcMap. The results of this study found that a total of 455 AEDs, including 227 pre-installed AEDs, could be placed in the study area, thus providing an additional 228 devices. Compared with 10 different installation methods that were set as experimental groups, our test results found that additional installations were able to cover 10% to 30% more actual out-of-hospital cardiac-arrest cases. The main contribution of this study is the proposal of a new method in locating AEDs in optimal areas while considering complicated urban environments. We predict that the cardiac-arrest-related mortality rate would be reduced through implementing the findings of this study.

  14. Urban metabolism: A review of research methodologies

    International Nuclear Information System (INIS)

    Zhang, Yan

    2013-01-01

    Urban metabolism analysis has become an important tool for the study of urban ecosystems. The problems of large metabolic throughput, low metabolic efficiency, and disordered metabolic processes are a major cause of unhealthy urban systems. In this paper, I summarize the international research on urban metabolism, and describe the progress that has been made in terms of research methodologies. I also review the methods used in accounting for and evaluating material and energy flows in urban metabolic processes, simulation of these flows using a network model, and practical applications of these methods. Based on this review of the literature, I propose directions for future research, and particularly the need to study the urban carbon metabolism because of the modern context of global climate change. Moreover, I recommend more research on the optimal regulation of urban metabolic systems. Highlights: •Urban metabolic processes can be analyzed by regarding cities as superorganisms. •Urban metabolism methods include accounting, assessment, modeling, and regulation. •Research methodologies have improved greatly since this field began in 1965. •Future research should focus on carbon metabolism and optimal regulation. -- The author reviews research progress in the field of urban metabolism, and based on her literature review, proposes directions for future research

  15. Complex Network Analysis of Guangzhou Metro

    OpenAIRE

    Yasir Tariq Mohmand; Fahad Mehmood; Fahd Amjad; Nedim Makarevic

    2015-01-01

    The structure and properties of public transportation networks can provide suggestions for urban planning and public policies. This study contributes a complex network analysis of the Guangzhou metro. The metro network has 236 kilometers of track and is the 6th busiest metro system of the world. In this paper topological properties of the network are explored. We observed that the network displays small world properties and is assortative in nature. The network possesses a high average degree...

  16. Discovering urban mobility patterns with PageRank based traffic modeling and prediction

    Science.gov (United States)

    Wang, Minjie; Yang, Su; Sun, Yi; Gao, Jun

    2017-11-01

    Urban transportation system can be viewed as complex network with time-varying traffic flows as links to connect adjacent regions as networked nodes. By computing urban traffic evolution on such temporal complex network with PageRank, it is found that for most regions, there exists a linear relation between the traffic congestion measure at present time and the PageRank value of the last time. Since the PageRank measure of a region does result from the mutual interactions of the whole network, it implies that the traffic state of a local region does not evolve independently but is affected by the evolution of the whole network. As a result, the PageRank values can act as signatures in predicting upcoming traffic congestions. We observe the aforementioned laws experimentally based on the trajectory data of 12000 taxies in Beijing city for one month.

  17. Watershed Urbanization Linked to Differences in Stream Bacterial Community Composition

    Directory of Open Access Journals (Sweden)

    Jacob D. Hosen

    2017-08-01

    Full Text Available Urbanization strongly influences headwater stream chemistry and hydrology, but little is known about how these conditions impact bacterial community composition. We predicted that urbanization would impact bacterial community composition, but that stream water column bacterial communities would be most strongly linked to urbanization at a watershed-scale, as measured by impervious cover, while sediment bacterial communities would correlate with environmental conditions at the scale of stream reaches. To test this hypothesis, we determined bacterial community composition in the water column and sediment of headwater streams located across a gradient of watershed impervious cover using high-throughput 16S rRNA gene amplicon sequencing. Alpha diversity metrics did not show a strong response to catchment urbanization, but beta diversity was significantly related to watershed impervious cover with significant differences also found between water column and sediment samples. Samples grouped primarily according to habitat—water column vs. sediment—with a significant response to watershed impervious cover nested within each habitat type. Compositional shifts for communities in urbanized streams indicated an increase in taxa associated with human activity including bacteria from the genus Polynucleobacter, which is widespread, but has been associated with eutrophic conditions in larger water bodies. Another indicator of communities in urbanized streams was an OTU from the genus Gallionella, which is linked to corrosion of water distribution systems. To identify changes in bacterial community interactions, bacterial co-occurrence networks were generated from urban and forested samples. The urbanized co-occurrence network was much smaller and had fewer co-occurrence events per taxon than forested equivalents, indicating a loss of keystone taxa with urbanization. Our results suggest that urbanization has significant impacts on the community composition

  18. Analysis of land suitability for urban development in Ahwaz County in southwestern Iran using fuzzy logic and analytic network process (ANP).

    Science.gov (United States)

    Malmir, Maryam; Zarkesh, Mir Masoud Kheirkhah; Monavari, Seyed Masoud; Jozi, Seyed Ali; Sharifi, Esmail

    2016-08-01

    The ever-increasing development of cities due to population growth and migration has led to unplanned constructions and great changes in urban spatial structure, especially the physical development of cities in unsuitable places, which requires conscious guidance and fundamental organization. It is therefore necessary to identify suitable sites for future development of cities and prevent urban sprawl as one of the main concerns of urban managers and planners. In this study, to determine the suitable sites for urban development in the county of Ahwaz, the effective biophysical and socioeconomic criteria (including 27 sub-criteria) were initially determined based on literature review and interviews with certified experts. In the next step, a database of criteria and sub-criteria was prepared. Standardization of values and unification of scales in map layers were done using fuzzy logic. The criteria and sub-criteria were weighted by analytic network process (ANP) in the Super Decision software. Next, the map layers were overlaid using weighted linear combination (WLC) in the GIS software. According to the research findings, the final land suitability map was prepared with five suitability classes of very high (5.86 %), high (31.93 %), medium (38.61 %), low (17.65 %), and very low (5.95 %). Also, in terms of spatial distribution, suitable lands for urban development are mainly located in the central and southern parts of the Ahwaz County. It is expected that integration of fuzzy logic and ANP model will provide a better decision support tool compared with other models. The developed model can also be used in the land suitability analysis of other cities.

  19. Electricity (in)accessibility to the urban poor in developing countries

    DEFF Research Database (Denmark)

    Singh, Rozita; Wang, Xiao; Mendoza, Juan Carlos

    2015-01-01

    More than half of the world’s population now lives in urban areas. The difficulties involved in providing new urban residents with a wide variety of services reveals a new face of poverty, one in which urban communities cannot access or afford basic modern energy services for their development...... and empowerment. As an enabler of development processes, access to electricity in urban and peri-urban contexts plays a key role in providing possibilities and solutions to the urban poor. Energy poverty is no longer a rural-only phenomenon, and a concerted effort is needed to find solutions. Taking...... this into account, the Global Network on Energy for Sustainable Development (GNESD) initiated the Urban Peri-Urban Energy Access (UPEA) project in 2006. The objective was to understand the barriers to energy access in the context of the urban poor in seven countries. Barriers from both the supply and demand sides...

  20. Relation between the St. Louis urban precipitation anomaly and synoptic weather factors

    International Nuclear Information System (INIS)

    Vogel, J.L.; Huff, F.A.

    1978-01-01

    The summer (June--August) rainfall distribution on the METROMEX network was analyzed to determine the synoptic conditions during which the urban-industrial regions of St. Louis affect the precipitation process. The rainfall patterns were stratified by direction of movement of convective entities in storm systems, surface wind direction, and basic synoptic weather types. The results provide support for enhancement of rainfall downstorm from the urban-industrial region. Although only 23% of the 330 storms moved from the west-southwest, the storms produced 42% of the network rainfall and were strong contributors to the rainfall anomaly that maximizes 25--30 km northeast of St. Louis. Cold front conditions with the major convective entities moving from the southwest, and squall lines with any storm motion were associated with the most intense rainstorms over the raingage network, and these storms were also largely responsible for the rainfall anomaly. The rainfall pattern based on air mass storms did not indicate any The rainfall pattern based on air mass storms did not indicate any significant urban enhancement of rainfall and study of squall zone storms suggested possible reduction of rainfall in the urban region

  1. A Case Study on Nitrogen Uptake and Denitrification in a Restored Urban Stream in Baltimore, Maryland

    Science.gov (United States)

    Restoring urban infrastructure and managing the nitrogen cycle represent emerging challenges for urban water quality. We investigated whether stormwater control measures (SCMs), a form of green infrastructure, integrated into restored and degraded urban stream networks can influe...

  2. 城市生态网络功能性连接辨识方法%Identifying and evaluating functional connectivity for building urban ecological networks

    Institute of Scientific and Technical Information of China (English)

    陈春娣; Meurk D. Colin; Ignatieva E. Maria; Stewart H. Glenn; 吴胜军

    2015-01-01

    城市生态网络是景观生态学应用领域研究的热点和重点之一,识别、评估生境之间的连接是构建生态网络的关键环节。在总结已有连接辨识方法的基础上,提出采用最小费用模型和图论分析相结合的方法,探讨功能性连接的辨识和优先恢复途径。以新西兰基督城为案例,分别利用景观发展强度指数建立阻力面,新西兰鸡毛松( Dacrycarpus dacrydioides)种子最大传播距离作为连接阈值来模拟、评价网络连接。结果表明:在1200 m 距离阈值下,共有408条连接,其重要性分为10类。其中Richmond—Petrie公园,Hansons—Auburn保护地,Centaurus公园—King George保护地是整个生态网络的关键连接;若去除,景观整体连接度将下降31.73%。此外,研究发现连接重要值与两端的源面积之和没有显著相关性,即面积大的源斑块之间的连接不一定对网络构建起关键作用,这一结论还有待进一步证明。针对缺少动物迁移资料的城市环境,改进最小费用模型和网络连接分析的部分参数;可操作性与实用性强,对中国城市区域生态恢复建设、栖息地选择具有借鉴意义。%With rapid urbanization and industrialization, habitat fragmentation and loss are inevitable. Under these circumstances, landscape connectivity and ecological networks have become a focus of applied landscape ecology. A well-connected ecological network is believed to facilitate energy and resource fluxes, species dispersal, genetic exchange and multiple other ecological processes, and to contribute to the maintenance of ecosystem stability and integrity. Identifying and evaluating functional connectivity between habitat patches is the key step in designing and building well-connected ecological networks. Based on a review of literature on linkage identification approaches, our study combined least-cost path modeling with graph-theory based network analysis to simulate, identify

  3. Participatory urban transformations in Savamala, Belgrade - capacities and limitations

    Directory of Open Access Journals (Sweden)

    Cvetinović Marija

    2016-01-01

    Full Text Available This paper analyses the implications of participatory urban design in Belgrade, namely of the series of recent unsolicited activities that has contributed to setting up a specific micro environment in the neighbourhood of Savamala. Its main aim is to promote bottom-up urban development, surpass current profit-oriented trends, and benefit from sociospatial contradictions as opportunities for creativity and participation. The Savamala neighbourhood is among the most important landmarks in Belgrade. Endowed with rich historical heritage and extraordinary spatial potential, Savamala is now a traffic bottleneck with intense pollution, urban noise and socio-spatial conflicts. In order to set up an engine for urban development, several streams of participatory activities have been launched by NGOs and IOs, such as: online campaigns and networking, informal research activities, pop-up events and instant actions for societal progress and bottom-up economic activities. The Actor-network theory (ANT methodological approach demystifies the circumstances of participation and the role of various actors in building pathways of urban transformations in Savamala, while the Multi-agent system (MAS proposes the framework for tracing their behaviour at the neighbourhood level. A complex post-socialist framework presents a challenge for these participatory activities to provide opportunities for urban transformations, based on social interest rather than on real estate speculations. In the lack of official strategies and institutionalised support, the MAS-ANT method involves estimating whether an economy of social exchange could contribute to improving the quality of life and functionality of urban systems.

  4. Spatial networks

    Science.gov (United States)

    Barthélemy, Marc

    2011-02-01

    Complex systems are very often organized under the form of networks where nodes and edges are embedded in space. Transportation and mobility networks, Internet, mobile phone networks, power grids, social and contact networks, and neural networks, are all examples where space is relevant and where topology alone does not contain all the information. Characterizing and understanding the structure and the evolution of spatial networks is thus crucial for many different fields, ranging from urbanism to epidemiology. An important consequence of space on networks is that there is a cost associated with the length of edges which in turn has dramatic effects on the topological structure of these networks. We will thoroughly explain the current state of our understanding of how the spatial constraints affect the structure and properties of these networks. We will review the most recent empirical observations and the most important models of spatial networks. We will also discuss various processes which take place on these spatial networks, such as phase transitions, random walks, synchronization, navigation, resilience, and disease spread.

  5. TrajAnalytics: A Web-Based Visual Analytics Software of Urban Trajectory

    OpenAIRE

    Zhao, Ye; AL-Dohuki, Shamal; Eynon, Thomas; Kamw, Farah; Sheets, David; Ma, Chao; Ye, Xinyue; Hu, Yueqi; Feng, Tinghao; Yang, Jing

    2017-01-01

    Advanced technologies in sensing and computing have created urban trajectory datasets of humans and vehicles travelling over urban road networks. Understanding and analyzing the large-scale, complex data reflecting city dynamics is of great importance to enhance both human lives and urban environments. Domain practitioners, researchers, and decision-makers need to store, manage, query and visualize such big datasets. We develop a software system named TrajAnalytics, which explicitly supports ...

  6. Importance of latrine communication in European rabbits shifts along a rural-to-urban gradient.

    Science.gov (United States)

    Ziege, Madlen; Bierbach, David; Bischoff, Svenja; Brandt, Anna-Lena; Brix, Mareike; Greshake, Bastian; Merker, Stefan; Wenninger, Sandra; Wronski, Torsten; Plath, Martin

    2016-06-14

    Information transfer in mammalian communication networks is often based on the deposition of excreta in latrines. Depending on the intended receiver(s), latrines are either formed at territorial boundaries (between-group communication) or in core areas of home ranges (within-group communication). The relative importance of both types of marking behavior should depend, amongst other factors, on population densities and social group sizes, which tend to differ between urban and rural wildlife populations. Our study is the first to assess (direct and indirect) anthropogenic influences on mammalian latrine-based communication networks along a rural-to-urban gradient in European rabbits (Oryctolagus cuniculus) living in urban, suburban and rural areas in and around Frankfurt am Main (Germany). The proportion of latrines located in close proximity to the burrow was higher at rural study sites compared to urban and suburban ones. At rural sites, we found the largest latrines and highest latrine densities close to the burrow, suggesting that core marking prevailed. By contrast, latrine dimensions and densities increased with increasing distance from the burrow in urban and suburban populations, suggesting a higher importance of peripheral marking. Increased population densities, but smaller social group sizes in urban rabbit populations may lead to an increased importance of between-group communication and thus, favor peripheral over core marking. Our study provides novel insights into the manifold ways by which man-made habitat alterations along a rural-to-urban gradient directly and indirectly affect wildlife populations, including latrine-based communication networks.

  7. Participatory Design in an Urban Context

    DEFF Research Database (Denmark)

    Gøtze, John

    of the conditions necessary for estab-lishing urban social networks, and different methodologies for doing so are examined. As part of this, a study is done on electronic democracy, i.e., different forms of information and communi-cation technologies (IT/ICT, Internet) that are actually and potentially applicable...... to innovative urban community development. The project combines theories of communication, dialogue and innovation with theories of systems, information, media and decision making. The project involves a comparative study of selected projects in the capital regions of Den-mark (Copenhagen) and Japan (Tokyo...

  8. Towards Scalable Distributed Framework for Urban Congestion Traffic Patterns Warehousing

    Directory of Open Access Journals (Sweden)

    A. Boulmakoul

    2015-01-01

    Full Text Available We put forward architecture of a framework for integration of data from moving objects related to urban transportation network. Most of this research refers to the GPS outdoor geolocation technology and uses distributed cloud infrastructure with big data NoSQL database. A network of intelligent mobile sensors, distributed on urban network, produces congestion traffic patterns. Congestion predictions are based on extended simulation model. This model provides traffic indicators calculations, which fuse with the GPS data for allowing estimation of traffic states across the whole network. The discovery process of congestion patterns uses semantic trajectories metamodel given in our previous works. The challenge of the proposed solution is to store patterns of traffic, which aims to ensure the surveillance and intelligent real-time control network to reduce congestion and avoid its consequences. The fusion of real-time data from GPS-enabled smartphones integrated with those provided by existing traffic systems improves traffic congestion knowledge, as well as generating new information for a soft operational control and providing intelligent added value for transportation systems deployment.

  9. Microsensing networks for sustainable cities

    CERN Document Server

    Lambrechts, Johannes

    2016-01-01

    This book explores the microsensing technologies and systems now available to monitor the quality of air and water within the urban environment and examines their role in the creation of sustainable cities against the background of the challenges posed by rapid urbanization. The opening section addresses the theoretical and conceptual background of microsensing networks. The coverage includes detailed description of microsensors, supported by design-specific equations, and clear explanation of the ways in which devices that harvest energy from ambient sources can detect and quantify pollution. The practical application of such systems in addressing environmental impacts within cities and in sustainable urban planning is then discussed with the aid of case studies in developing countries. The book will be of interest to all who wish to understand the benefits of microsensing networks in promoting sustainable cities through better delivery of information on health hazards and improved provision of data to envir...

  10. Citizen Management of Technology: A Science and Technology Studies approach to wireless networks and urban governance trough guifi.net

    Directory of Open Access Journals (Sweden)

    Yann Bona Beauvois

    2011-03-01

    Full Text Available Thesis presented at the Departament de Psicologia Social de la UAB by Yann Bona on December, 2010. Directed by Dr. Joan Pujol Tarrés.This dissertation explores the many ways in which citizens aiming to manage technologies in urban scape relate to public administrations. To accomplish it's task, it brings forward certain STS notions such as cosmopolitics, hybrid composition or technical democracy. On a general level, this thesis seeks an answer to Bruno Latour concern with what does it mean to conceive the technical as political?. We offer a set of conclusions based on what we choose to name a Sociotechnique of Public Policy .Our work relies on a case study focused on a free and open wireless network (located in Catalunya for the most part and called guifi.net that emerged from the desire and will of Civil Society wich, up to date, turns out to be the world's biggest free wireless network.

  11. Urban sharing culture

    DEFF Research Database (Denmark)

    Fjalland, Emmy Laura Perez

    of the structures of the networked urban mobilities and holds the potentials to change the future mobilities. References Bauman, Zygmunt. 2000. Liquid Modernity. Cambridge: Polity. Beck, Ulrich. 1992. Risk Society: Towards a New Modernity (Published in Association with Theory, Culture & Society). London: SAGE......In urban areas sharing cultures, services and economies are rising. People share, rent and recycle their homes, cars, bikes, rides, tools, cloths, working space, knowhow and so on. The sharing culture can be understood as mobilities (Kesselring and Vogl 2013) of goods, values and ideas reshaping...... problems and side effects from concentration of consumption and contamination; and due to the shift from ownership to access it change our basic social cultural norms (Sayer 2005; Sayer 2011) about the ‘good’ life and social status (Freudendal-Pedersen 2007), commons and individuality, responsibility...

  12. Can Aerosol Offset Urban Heat Island Effect?

    Science.gov (United States)

    Jin, M. S.; Shepherd, J. M.

    2009-12-01

    The Urban Heat Island effect (UHI) refers to urban skin or air temperature exceeding the temperatures in surrounding non-urban regions. In a warming climate, the UHI may intensify extreme heat waves and consequently cause significant health and energy problems. Aerosols reduce surface insolation via the direct effect, namely, scattering and absorbing sunlight in the atmosphere. Combining the National Aeronautics and Space Administration (NASA) AERONET (AErosol RObotic NETwork) observations over large cities together with Weather Research and Forecasting Model (WRF) simulations, we find that the aerosol direct reduction of surface insolation range from 40-100 Wm-2, depending on seasonality and aerosol loads. As a result, surface skin temperature can be reduced by 1-2C while 2-m surface air temperature by 0.5-1C. This study suggests that the aerosol direct effect is a competing mechanism for the urban heat island effect (UHI). More importantly, both aerosol and urban land cover effects must be adequately represented in meteorological and climate modeling systems in order to properly characterize urban surface energy budgets and UHI.

  13. Urban effects on convective precipitation in Mexico city

    Science.gov (United States)

    Jauregui, Ernesto; Romales, Ernesto

    This paper reports on urban-related convective precipitation anomalies in a tropical city. Wet season (May-October) rainfall for an urban site (Tacubaya) shows a significant trend for the period 1941-1985 suggesting an urban effect that has been increasing as the city grew. On the other hand, rainfall at a suburban (upwind) station apparently unaffected by urbanization, has remained unchanged. Analysis of historical records of hourly precipitation for an urban station shows that the frequency of intense (> 20 mm h -1) rain showers has increased in recent decades. Using a network of automatic rainfall stations, areal distribution of 24 h isoyets show a series of maxima within the urban perimeter which may be associated to the heat island phenomenon. Isochrones of the beginning of rain are used to estimate direction and speed of movement of the rain cloud cells. The daytime heat island seems to be associated with the intensification of rain showers.

  14. Prioritizing recovery of urban lifelines in the aftermath of hazards: Transportation in post-Harvey Houston

    Science.gov (United States)

    Warner, M. E.; Bhatia, U.; Sela, L.; Wang, R.; Kodra, E.; Ganguly, A. R.

    2017-12-01

    A well-designed recovery strategy for lifeline infrastructure networks can lead to faster and more reliable restoration of essential services in the aftermath of natural catastrophes such as hurricanes or earthquakes. Urban and regional lifelines impact one another, while the recovery of urban lifelines in turn impacts regional infrastructural resilience, owing to the interdependence of lifelines across scales. Prior work by our team, often in collaboration, has led to the development of new recovery approaches based on network science and engineering, including centrality measures from network science, information theoretic metrics, and network optimization approaches. We have developed proof-of-concept demonstrations at both regional scales, such as for the Indian Railways Network and the US National Airspace System both subjected to multiple hazards, and to urban settings, such as the post-Hurricane recovery of combined power-subway system-of-systems in Boston and the New York City MTA after Hurricane Sandy. Here we make an attempt to understand how such methods may have been, or continue to be, applicable to the transportation network in Houston post-Harvey, and more broadly, how and to what extent lessons learned in urban and regional resilience may generalize across cases. We make an assessment of the state of the literature, process understanding, simulation models, data science methods, and best practices, necessary to address problems of this nature, with a particular focus on post-Harvey recovery of transportation services in Houston.

  15. AUTOMATIC EXTRACTION AND TOPOLOGY RECONSTRUCTION OF URBAN VIADUCTS FROM LIDAR DATA

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2015-08-01

    Full Text Available Urban viaducts are important infrastructures for the transportation system of a city. In this paper, an original method is proposed to automatically extract urban viaducts and reconstruct topology of the viaduct network just with airborne LiDAR point cloud data. It will greatly simplify the effort-taking procedure of viaducts extraction and reconstruction. In our method, the point cloud first is filtered to divide all the points into ground points and none-ground points. Region growth algorithm is adopted to find the viaduct points from the none-ground points by the features generated from its general prescriptive designation rules. Then, the viaduct points are projected into 2D images to extract the centerline of every viaduct and generate cubic functions to represent passages of viaducts by least square fitting, with which the topology of the viaduct network can be rebuilt by combining the height information. Finally, a topological graph of the viaducts network is produced. The full-automatic method can potentially benefit the application of urban navigation and city model reconstruction.

  16. Evaluatiopn of Strategies for Modifying Urban Storm Water Drainage System Using Risk-based Criteria

    Directory of Open Access Journals (Sweden)

    mahsa soleimani

    2016-01-01

    Full Text Available Appropriate modification of existing urban storm water drainage networks may help reduce network inundation and flood-borne pollution risks. It will, therefore, be necessary to analyze the risks associated with water quantity and quality during urban flooding before any reconstruction strategies can be identified that are adaptable to, or compatible with, urban sustainable development strategies. In this paper, three network modification strategies are evaluated against the three criteria of network inundation at different sections, flood pollution risks, and modification plan costs. The modification strategies evaluated include the conventional approach of increasing conduit dimensions as well as the two novels swale and bio-retention systems. The strategies are then prioritised using a Multi-Criteria Decision Analysis (MCDA method. The application of the proposed methodology is illustrated in the case study of urban storm water drainage systems in the Golestan City in Tehran Province for which a hydrological and hydraulic simulation model has been developed using the SWMM software. The results show that the swale system is the best strategy with an approximate cost of 20 billion Rials (almost US$ 6 million. Compared to the existing system in operation, the proposed system will be capable of reducing 59% of the quantitative risk of flooding (inundation and 26% of the water quality risk (pollution loads.

  17. TIGeR : A Traffic-Aware Intersection-Based Geographical routing protocol for urban VANETs

    NARCIS (Netherlands)

    Tavakoli, Rasool; Nabi, M.

    2013-01-01

    In recent years, vehicular ad-hoc networks (VANETs) have received increasing interests because of their promising solutions in many urban applications. VANETs are distinguished from other kinds of ad-hoc networks, such as Mobile Ad-hoc Networks (MANETs), by high mobility and reduced communications.

  18. Potential travel cost saving in urban public-transport networks using smartphone guidance

    Science.gov (United States)

    2018-01-01

    Public transport (PT) is a key element in most major cities around the world. With the development of smartphones, available journey planning information is becoming an integral part of the PT system. Each traveler has specific preferences when undertaking a trip, and these preferences can also be reflected on the smartphone. This paper considers transit assignment in urban public-transport networks in which the passengers receive smartphone-based information containing elements that might influence the travel decisions in relation to line loads, as well as passenger benefits, and the paper discusses the transition from the current widespread choosing approach to a personalized decision-making approach based on smartphone information. The approach associated with smartphone guidance that considers passengers’ preference on travel time, waiting time and transfer is proposed in the process of obtaining his/her preferred route from the potential travel routes generated by the Deep First Search (DFS) method. Two other approaches, based on the scenarios reflecting reality, include passengers with access to no real time information, and passengers that only have access to the arrival time at the platform are used as comparisons. For illustration, the same network proposed by Spiess and Florian is utilized on the experiments in an agent-based model. Two experiments are conducted respectively according to whether each passenger’s choosing method is consistent. As expected, the results in the first experiment showed that the travel for consistent passengers with smartphone guidance was clearly shorter and that it can reduce travel time exceeding 15% and weighted cost exceeding 20%, and the average saved time approximated 3.88 minutes per passenger. The second experiment presented that travel cost, as well as cost savings, gradually decreased by employing smartphone guidance, and the maximum cost savings accounted for 14.2% of the total weighted cost. PMID:29746528

  19. Potential travel cost saving in urban public-transport networks using smartphone guidance.

    Science.gov (United States)

    Song, Cuiying; Guan, Wei; Ma, Jihui

    2018-01-01

    Public transport (PT) is a key element in most major cities around the world. With the development of smartphones, available journey planning information is becoming an integral part of the PT system. Each traveler has specific preferences when undertaking a trip, and these preferences can also be reflected on the smartphone. This paper considers transit assignment in urban public-transport networks in which the passengers receive smartphone-based information containing elements that might influence the travel decisions in relation to line loads, as well as passenger benefits, and the paper discusses the transition from the current widespread choosing approach to a personalized decision-making approach based on smartphone information. The approach associated with smartphone guidance that considers passengers' preference on travel time, waiting time and transfer is proposed in the process of obtaining his/her preferred route from the potential travel routes generated by the Deep First Search (DFS) method. Two other approaches, based on the scenarios reflecting reality, include passengers with access to no real time information, and passengers that only have access to the arrival time at the platform are used as comparisons. For illustration, the same network proposed by Spiess and Florian is utilized on the experiments in an agent-based model. Two experiments are conducted respectively according to whether each passenger's choosing method is consistent. As expected, the results in the first experiment showed that the travel for consistent passengers with smartphone guidance was clearly shorter and that it can reduce travel time exceeding 15% and weighted cost exceeding 20%, and the average saved time approximated 3.88 minutes per passenger. The second experiment presented that travel cost, as well as cost savings, gradually decreased by employing smartphone guidance, and the maximum cost savings accounted for 14.2% of the total weighted cost.

  20. SOME EMPIRICAL RELATIONS BETWEEN TRAVEL SPEED, TRAFFIC VOLUME AND TRAFFIC COMPOSITION IN URBAN ARTERIALS

    Directory of Open Access Journals (Sweden)

    Eleni I. VLAHOGIANNI, Ph.D.

    2007-01-01

    Full Text Available The effects of traffic mix (the percentage of cars, trucks, buses and so on are of particular interest in the speed-volume relationship in urban signalized arterials under various geometric and control characteristics. The paper presents some empirical observations on the relation between travel speed, traffic volume and traffic composition in urban signalized arterials. A methodology based on emerging self-organizing structures of neural networks to identify regions in the speed-volume relationship with respect to traffic composition and Bayesian networks to evaluate the effect of different types of motorized vehicles on prevailing traffic conditions is proposed. Results based on data from a large urban network indicate that the variability in traffic conditions can be described by eight regions in speed-volume relationship with respect to traffic composition. Further evaluation of the effect of motorized vehicles in each region separately indicates that the effect of traffic composition decreases with the onset of congestion. Moreover, taxis and motorcycles are the primary affecting parameter of the form of the speed-volume relationship in urban arterials.

  1. Using smartphone batteries as an urban thermometer

    Science.gov (United States)

    Droste, Arjan; Pape, Jan-Jaap; Overeem, Aart; Leijnse, Hidde; Steeneveld, Gert-Jan; Van Delden, Aarnout; Uijlenhoet, Remko

    2017-04-01

    Taking meteorological measurements in the urban environment is notoriously difficult due to the complex geometry at street and neighbourhood level. Traditional weather stations are absent in cities because of WMO regulations, so urban data has to come from typically expensive measurement-networks, or short intensive campaigns. While traditional measurements are scarce, there is an abundance of smart devices in cities: the well-known Internet of Things. It is for these reasons that crowdsourcing data has an enormous potential in cities, to deliver vast quantities of data without the maintenance costs of a measurement network. A promising source of potentially valuable data is the smartphone, because of its ubiquity and the many sensors most newer phone models now possess. Since most people nowadays have a smartphone, and carry it around wherever they go, data logged by the phone can be used to estimate the urban air temperature. A persistent log taken by nearly all smartphone models, even those without air temperature sensors, is the smartphone's battery temperature. The free OpenSignal smartphone application logs this battery temperature (among many other variables) and the position of the smartphone, which makes it possible to estimate the urban air temperature through a straightforward heat transfer model relating battery temperature to air and body temperature. The obtained urban temperatures are accurate within 1 to 2 degrees of certified measurement stations, proving the huge potential of this innovative method. This poster focuses on describing how thousands of daily smartphone battery temperature measurements can be translated to a relatively robust estimation of an urban air temperature, using 2 years of data from São Paulo in Brazil. Analysis of the results is presented in a separate session.

  2. Smart thermal networks for smart cities - Introduction of concepts and measures

    Science.gov (United States)

    Schmidt, R. R.; Pol, O.; Basciotti, D.; Page, J.

    2012-10-01

    In order to contribute to high living standards, climate mitigation and energy supply security, future urban energy systems require a holistic approach. In particular an intelligent integration of thermal networks is necessary. This paper will briefly present the "smart city" concept and introduce an associated definition for smart thermal networks defined on three levels: 1. the interaction with urban planning processes and the interface to the overall urban energy system, 2. the adaptation of the temperature level and 3. supply and demand-side management strategies.

  3. Fluid Mechanics of Urban Environments

    Science.gov (United States)

    Fernando, Harindra J.

    2008-11-01

    The rapid urbanization of the Earth has led to highly populated cities that act as concentrated centers of anthropogenic stressors on the natural environment. The degradation of environmental quality due to such stressors, in turn, greatly impacts human behavior. Anthropogenic stressors largely originate as a result of coupling between man-made urban elements (i.e., networks of engineering and socio-economic infrastructures) and the environment, for which surrounding fluid motions play a key role. In recent years, research efforts have been directed at the understanding and modeling of fluid motions in urban areas, infrastructure dynamics and interactions thereof, with the hope of identifying environmental impacts of urbanization and complex outcomes (or ``emergent properties'') of nominally simple interactions between infrastructures and environment. Such consequences play an important role in determining the ``resilience'' of cities under anthropogenic stressors, defined as maintaining the structure and essential functions of an urbanity without regime shifts. Holistic integrated models that meld the dynamics of infrastructures and environment as well as ``quality of life'' attributes are becoming powerful decision-making tools with regard to sustainability of urban areas (continuance or even enhancement of socio-economic activities in harmony with the environment). The rudimentary forms of integrated models are beginning to take shape, augmented by comprehensive field studies and advanced measurement platforms to validate them. This presentation deals with the challenges of modeling urban atmosphere, subject to anthropogenic forcing. An important emergent property, the Urban Heat Island, and its role in determining resilience and sustainability of cities will be discussed based on the prediction of a coupled model.

  4. Automatic Generalizability Method of Urban Drainage Pipe Network Considering Multi-Features

    Science.gov (United States)

    Zhu, S.; Yang, Q.; Shao, J.

    2018-05-01

    Urban drainage systems are indispensable dataset for storm-flooding simulation. Given data availability and current computing power, the structure and complexity of urban drainage systems require to be simplify. However, till data, the simplify procedure mainly depend on manual operation that always leads to mistakes and lower work efficiency. This work referenced the classification methodology of road system, and proposed a conception of pipeline stroke. Further, length of pipeline, angle between two pipelines, the pipeline belonged road level and diameter of pipeline were chosen as the similarity criterion to generate the pipeline stroke. Finally, designed the automatic method to generalize drainage systems with the concern of multi-features. This technique can improve the efficiency and accuracy of the generalization of drainage systems. In addition, it is beneficial to the study of urban storm-floods.

  5. Quantification of groundwater infiltration and surface water inflows in urban sewer networks based on a multiple model approach.

    Science.gov (United States)

    Karpf, Christian; Krebs, Peter

    2011-05-01

    The management of sewer systems requires information about discharge and variability of typical wastewater sources in urban catchments. Especially the infiltration of groundwater and the inflow of surface water (I/I) are important for making decisions about the rehabilitation and operation of sewer networks. This paper presents a methodology to identify I/I and estimate its quantity. For each flow fraction in sewer networks, an individual model approach is formulated whose parameters are optimised by the method of least squares. This method was applied to estimate the contributions to the wastewater flow in the sewer system of the City of Dresden (Germany), where data availability is good. Absolute flows of I/I and their temporal variations are estimated. Further information on the characteristics of infiltration is gained by clustering and grouping sewer pipes according to the attributes construction year and groundwater influence and relating these resulting classes to infiltration behaviour. Further, it is shown that condition classes based on CCTV-data can be used to estimate the infiltration potential of sewer pipes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Cumulative Causation of Rural Migration and Initial Peri-Urbanization in China.

    Science.gov (United States)

    Hao, Lingxin

    2012-01-01

    This paper posits that rural migration feeds the high demand for cheap labor in peri-urbanization, which is driven by globalization, flows of foreign capital, and entrepreneurial local governments. While the gravity model and push/pull perspective ignore the dynamics of migratory course, we use the cumulative causation of migration theory to conceptualize social expectations for outmigration and social resources from migrant networks in destinations. Four major findings are drawn from this demographic analysis based on micro data from China's 2000 Census. First, the expectation of outmigration significantly increases outmigration, and this effect is independent of push factors. Second, foreign direct investment (FDI) contributes to attracting rural labor migrants from other provinces to peri-urban areas as it does to cities. Third, social resources from migrant networks play an important role in attracting rural labor migrants to both city and noncity destinations. Fourth, the importance of wage differentials declines in gravitating rural labor migrants to peri-urban areas. These findings provide tentative evidence that rural labor migration is indispensable during initial peri-urbanization. Infused with flows of FDI and entrepreneurial local governments, rural migration has created a favorable initial condition for peri-urbanization.

  7. Mobility Network and Safety

    Directory of Open Access Journals (Sweden)

    Adriana Galderisi

    2010-04-01

    Full Text Available Mobility network is crucial for ensuring territorial safety with respect to natural and technological hazards. They represent a basic support to community’s everyday life although being exposed elements often characterized by high vulnerability to different hazards and, in the meanwhile, strategic equipments for emergency management. Physical damages or the lack in functioning of those networks may greatly increase the loss of human lives caused by hazardous events as well as produce relevant economic damages at medium and long term. Although the relevance of the mobility networks in assuring territorial safety is at present largely recognized, risk analyses have been long focused on buildings’ vulnerability or, even where they have paid attention to mobility network, they have been mainly focused on the physical damages that a given hazard could may induce on individual elements of such network. It is recent the awareness that mobility network represents a system, characterized by relevant interdependences both among its elements and among network infrastructures and urban systems. Based on these assumptions, this paper points out the heterogeneous aspects of the mobility network vulnerability and their relevance in increasing the overall territorial or urban vulnerability to hazardous events. Therefore, an in-depth investigation of the concept of mobility network vulnerability is provided, in order to highlight the aspects mostly investigated and more recent research perspectives. Finally, a case study in the Campania Region is presented in order to point out how traditional risk analyses, generally referred to individual hazards, can sometimes led to invest in the mobility network improvement or development which, targeted to increase the security of a territory result, on the opposite, in an increase of the territorial vulnerability.

  8. Safety analysis of urban arterials at the meso level.

    Science.gov (United States)

    Li, Jia; Wang, Xuesong

    2017-11-01

    Urban arterials form the main structure of street networks. They typically have multiple lanes, high traffic volume, and high crash frequency. Classical crash prediction models investigate the relationship between arterial characteristics and traffic safety by treating road segments and intersections as isolated units. This micro-level analysis does not work when examining urban arterial crashes because signal spacing is typically short for urban arterials, and there are interactions between intersections and road segments that classical models do not accommodate. Signal spacing also has safety effects on both intersections and road segments that classical models cannot fully account for because they allocate crashes separately to intersections and road segments. In addition, classical models do not consider the impact on arterial safety of the immediately surrounding street network pattern. This study proposes a new modeling methodology that will offer an integrated treatment of intersections and road segments by combining signalized intersections and their adjacent road segments into a single unit based on road geometric design characteristics and operational conditions. These are called meso-level units because they offer an analytical approach between micro and macro. The safety effects of signal spacing and street network pattern were estimated for this study based on 118 meso-level units obtained from 21 urban arterials in Shanghai, and were examined using CAR (conditional auto regressive) models that corrected for spatial correlation among the units within individual arterials. Results showed shorter arterial signal spacing was associated with higher total and PDO (property damage only) crashes, while arterials with a greater number of parallel roads were associated with lower total, PDO, and injury crashes. The findings from this study can be used in the traffic safety planning, design, and management of urban arterials. Copyright © 2017 Elsevier Ltd. All

  9. Public private co-operation in urban regeneration investment planning

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole; Larsen, Jacob Norvig

    development. However, we believe that municipalities can become much better at attracting private investors and developers, partly because there is knowledge about the motives and backgrounds for the developers' engagement in the urban regeneration. Based on data from a number of case studies and interviews......Increasing renovation costs and ever more limited public funding for urban regeneration in combination with a political desire to stimulate the development of a sense of ownership in urban regeneration neighbourhoods has brought about a growing interest in attracting private sector funding...... with developers we argue that developers own networks are more likely to lead them to the urban regeneration areas, than knowledge of the urban regeneration itself. Also, the study reveals a mutual knowledge-gap between the municipal planners and developers; planners have limited knowledge of developers...

  10. Network analysis applications in hydrology

    Science.gov (United States)

    Price, Katie

    2017-04-01

    Applied network theory has seen pronounced expansion in recent years, in fields such as epidemiology, computer science, and sociology. Concurrent development of analytical methods and frameworks has increased possibilities and tools available to researchers seeking to apply network theory to a variety of problems. While water and nutrient fluxes through stream systems clearly demonstrate a directional network structure, the hydrological applications of network theory remain under­explored. This presentation covers a review of network applications in hydrology, followed by an overview of promising network analytical tools that potentially offer new insights into conceptual modeling of hydrologic systems, identifying behavioral transition zones in stream networks and thresholds of dynamical system response. Network applications were tested along an urbanization gradient in Atlanta, Georgia, USA. Peachtree Creek and Proctor Creek. Peachtree Creek contains a nest of five long­term USGS streamflow and water quality gages, allowing network application of long­term flow statistics. The watershed spans a range of suburban and heavily urbanized conditions. Summary flow statistics and water quality metrics were analyzed using a suite of network analysis techniques, to test the conceptual modeling and predictive potential of the methodologies. Storm events and low flow dynamics during Summer 2016 were analyzed using multiple network approaches, with an emphasis on tomogravity methods. Results indicate that network theory approaches offer novel perspectives for understanding long­ term and event­based hydrological data. Key future directions for network applications include 1) optimizing data collection, 2) identifying "hotspots" of contaminant and overland flow influx to stream systems, 3) defining process domains, and 4) analyzing dynamic connectivity of various system components, including groundwater­surface water interactions.

  11. Quantifying Urban Groundwater in Environmental Field Observatories

    Science.gov (United States)

    Welty, C.; Miller, A. J.; Belt, K.; Smith, J. A.; Band, L. E.; Groffman, P.; Scanlon, T.; Warner, J.; Ryan, R. J.; Yeskis, D.; McGuire, M. P.

    2006-12-01

    Despite the growing footprint of urban landscapes and their impacts on hydrologic and biogeochemical cycles, comprehensive field studies of urban water budgets are few. The cumulative effects of urban infrastructure (buildings, roads, culverts, storm drains, detention ponds, leaking water supply and wastewater pipe networks) on temporal and spatial patterns of groundwater stores, fluxes, and flowpaths are poorly understood. The goal of this project is to develop expertise and analytical tools for urban groundwater systems that will inform future environmental observatory planning and that can be shared with research teams working in urban environments elsewhere. The work plan for this project draws on a robust set of information resources in Maryland provided by ongoing monitoring efforts of the Baltimore Ecosystem Study (BES), USGS, and the U.S. Forest Service working together with university scientists and engineers from multiple institutions. A key concern is to bridge the gap between small-scale intensive field studies and larger-scale and longer-term hydrologic patterns using synoptic field surveys, remote sensing, numerical modeling, data mining and visualization tools. Using the urban water budget as a unifying theme, we are working toward estimating the various elements of the budget in order to quantify the influence of urban infrastructure on groundwater. Efforts include: (1) comparison of base flow behavior from stream gauges in a nested set of watersheds at four different spatial scales from 0.8 to 171 km2, with diverse patterns of impervious cover and urban infrastructure; (2) synoptic survey of well water levels to characterize the regional water table; (3) use of airborne thermal infrared imagery to identify locations of groundwater seepage into streams across a range of urban development patterns; (4) use of seepage transects and tracer tests to quantify the spatial pattern of groundwater fluxes to the drainage network in selected subwatersheds; (5

  12. Mapping the urban form of coastal fishing towns in Algarve: Olhão and Vila Real de Santo António

    Directory of Open Access Journals (Sweden)

    Mafalda Batista Pacheco

    Full Text Available Abstract The paper examines the urban growth patterns of two coastal fishing towns in southern Portugal: Olhão and Vila Real de Santo António. The goal is to investigate the relationship between the configurational and network properties of the urban forms in order to identify generative or emergent patterns, understanding their particular urban morphology. The Space Syntax Theory, applied to the syntactical modelling of these towns, is used to understand the urban processes. Topological variables, such as connectivity, integration and intelligibility, are calculated by DepthMap Software and the Theory of the “Deformed Wheel” is used to represent the evolutionary trends and to identify generic rules. The study is developed by comparing the two urban networks in two moments of their evolution, first in the mid-20th century, which corresponds to the historic core, and second corresponding to the present day. The main results demonstrate a contrast between the segregated network of Olhão's irregular historic centre and the integrated network of Vila Real de Santo António's regular historic centre, revealed by the value of integration variable. The urban expansion of these towns during the last decades decreased the value of integration and aggravated the intelligibility of the urban fabric. The application of syntactic approaches, with quantitative analysis, aims to complement the traditional procedures of the History of Urbanism, developing an operational method adaptable to the study of urban morphology.

  13. Urban flood simulation based on the SWMM model

    Directory of Open Access Journals (Sweden)

    L. Jiang

    2015-05-01

    Full Text Available China is the nation with the fastest urbanization in the past decades which has caused serious urban flooding. Flood forecasting is regarded as one of the important flood mitigation methods, and is widely used in catchment flood mitigation, but is not widely used in urban flooding mitigation. This paper, employing the SWMM model, one of the widely used urban flood planning and management models, simulates the urban flooding of Dongguan City in the rapidly urbanized southern China. SWMM is first set up based on the DEM, digital map and underground pipeline network, then parameters are derived based on the properties of the subcatchment and the storm sewer conduits; the parameter sensitivity analysis shows the parameter robustness. The simulated results show that with the 1-year return period precipitation, the studied area will have no flooding, but for the 2-, 5-, 10- and 20-year return period precipitation, the studied area will be inundated. The results show the SWMM model is promising for urban flood forecasting, but as it has no surface runoff routing, the urban flooding could not be forecast precisely.

  14. AUTOMATIC GENERALIZABILITY METHOD OF URBAN DRAINAGE PIPE NETWORK CONSIDERING MULTI-FEATURES

    Directory of Open Access Journals (Sweden)

    S. Zhu

    2018-05-01

    Full Text Available Urban drainage systems are indispensable dataset for storm-flooding simulation. Given data availability and current computing power, the structure and complexity of urban drainage systems require to be simplify. However, till data, the simplify procedure mainly depend on manual operation that always leads to mistakes and lower work efficiency. This work referenced the classification methodology of road system, and proposed a conception of pipeline stroke. Further, length of pipeline, angle between two pipelines, the pipeline belonged road level and diameter of pipeline were chosen as the similarity criterion to generate the pipeline stroke. Finally, designed the automatic method to generalize drainage systems with the concern of multi-features. This technique can improve the efficiency and accuracy of the generalization of drainage systems. In addition, it is beneficial to the study of urban storm-floods.

  15. Social networks and substance use among at-risk emerging adults living in disadvantaged urban areas in the southern United States: a cross-sectional naturalistic study.

    Science.gov (United States)

    Tucker, Jalie A; Cheong, JeeWon; Chandler, Susan D; Crawford, Scott M; Simpson, Cathy A

    2015-09-01

    Substance use and risk-taking are common during emerging adulthood, a transitional period when peer influences often increase and family influences decrease. Investigating relationships between social network features and substance use can inform community-based prevention programs. This study investigated whether substance use among emerging adults living in disadvantaged urban areas was influenced by peer and family social network messages that variously encouraged and discouraged substance use. Cross-sectional, naturalistic field study. Lower-income neighborhoods in Birmingham, Alabama, USA with 344 participants (110 males, 234 females, ages 15-25 years; mean = 18.86 years), recruited via respondent-driven sampling. During structured interviews conducted in community locations, the Alcohol, Smoking and Substance Involvement Screening Test assessed substance use and related problems. Predictor variables were network characteristics, including presence of substance-using peers, messages from friends and family members about substance use and network sources for health information. Higher substance involvement was associated with friend and family encouragement of use and having close peer network members who used substances (Ps Social networks appear to be important in both promoting and preventing substance use in disadvantaged young adults in the United States. © 2015 Society for the Study of Addiction.

  16. An Urban Way of Life

    DEFF Research Database (Denmark)

    Haase, Kirstine

    This paper presents how my PhD project “An Urban Way of life – practices, networks and identities in Odense 1100-1500 AD” engages with the overall research perspectives presented in the research and public outreach project “Urban Encounters”. I will explore how urbanism in Medieval Odense can...... of the cultural deposits and sampling for scientific analysis. It resulted in an extensive finds assemblage and well-preserved structures such as booths, houses, byres and stables, latrines, paths, roads, fences, manure heaps and much more with a vast potential for further research. One of the features...... was a large latrine from the 15th century that contained a variety of finds such as coopered beakers, seeds from plants or fruits and ceramics. The latrine does not only tell about people and practices of daily life but studied with a contextual approach and chaine operatoire as point of departure...

  17. High-Speed Railways and Urban Networks in China

    NARCIS (Netherlands)

    Yang, Haoran

    2018-01-01

    Worldwide, High-Speed Railway (HSR) networks have been developed intensely over the last few decades, such as Tokyo-Osaka, the first HSR corridor in Japan, the TGV in France and the ICE in Germany. HSR has also experienced exponential growth in China so that currently China’s HSR networks are the

  18. Contributions of fuel combustion to pollution by airborne particles in urban and non-urban environments

    International Nuclear Information System (INIS)

    1995-06-01

    The application of ion beam analysis (IBA) techniques to aerosol pollution problems has been used in a number of countries since the late 1970's and early 1980's. The technique, however, had not been tested in Australia. This document is the final report of a project which aimed to establish a fine particle monitoring network covering the greater Wollongong/Sydney/ Newcastle ares, investigate the relationships between fuel combustion and fine particle aerosols in urban and non urban environments, add to the limited database of baseline information on concentrations of fine particles resulting from such processes as fossil fuel burning and industrial manufacturing, identify and quantify sources of fine particles in New South Wales, and introduce into Australia accelerator based IBA techniques for the analysis of filter papers obtained from large scale monitoring networks. These objectives were addressed by the project which identified and quantified some sources of fine particles and established some relationships between fuel combustion and fine aerosols. More work is required to fully quantify relationships between natural and anthropogenic fine particle sources. 24 tabs., 44 figs., 83 refs

  19. City networks collaboration and planning for health and sustainability

    CERN Document Server

    Migdalas, Athanasios; Rassia, Stamatina; Pardalos, Panos

    2017-01-01

    Sustainable development within urban and rural areas, transportation systems, logistics, supply chain management, urban health, social services, and architectural design are taken into consideration in the cohesive network models provided in this book. The ideas, methods, and models presented consider city landscapes and quality of life conditions based on mathematical network models and optimization. Interdisciplinary Works from prominent researchers in mathematical modeling, optimization, architecture, engineering, and physics are featured in this volume to promote health and well-being through design.   Specific topics include: -          Current technology that form the basis of future living in smart cities -          Interdisciplinary design and networking of large-scale urban systems  -          Network communication and route traffic optimization -          Carbon dioxide emission reduction -          Closed-loop logistics chain management and operation ...

  20. Flooding the sanitary city : Planning discourse and the materiality of urban sanitation in Hanoi

    OpenAIRE

    Schramm, S.

    2016-01-01

    Urban water flows are constitutive elements of Hanoi’s morphology. Regular floods across the city illustrate that Hanoi’s amphibious character is a central impediment to the installa- tion of a ‘dry and sanitary city’, the global modernist ideal of a separation of urban waste- water flows from public space through their redirection into large underground networks. Currently, the first attempt by the city government to construct a citywide sewerage network since the colonial period is taking p...

  1. Investigating the consequences of urban volcanism using a scenario approach II: Insights into transportation network damage and functionality

    Science.gov (United States)

    Blake, Daniel M.; Deligne, Natalia I.; Wilson, Thomas M.; Lindsay, Jan M.; Woods, Richard

    2017-06-01

    Transportation networks are critical infrastructure in urban environments. Before, during and following volcanic activity, these networks can incur direct and indirect impacts, which subsequently reduces the Level-of-Service available to transportation end-users. Additionally, reductions in service can arise from management strategies including evacuation zoning, causing additional complications for transportation end-users and operators. Here, we develop metrics that incorporate Level-of-Service for transportation end-users as the key measure of vulnerability for multi-hazard volcanic impact and risk assessments. A hypothetical eruption scenario recently developed for the Auckland Volcanic Field, New Zealand, is applied to describe potential impacts of a small basaltic eruption on different transportation modes, namely road, rail, and activities at airports and ports. We demonstrate how the new metrics can be applied at specific locations worldwide by considering the geophysical hazard sequence and evacuation zones in this scenario, a process that was strongly informed by consultation with transportation infrastructure providers and emergency management officials. We also discuss the potential implications of modified hazard sequences (e.g. different wind profiles during the scenario, and unrest with no resulting eruption) on transportation vulnerability and population displacement. The vent area of the eruption scenario used in our study is located north of the Māngere Bridge suburb of Auckland. The volcanic activity in the scenario progresses from seismic unrest, through phreatomagmatic explosions generating pyroclastic surges to a magmatic phase generating a scoria cone and lava flows. We find that most physical damage to transportation networks occurs from pyroclastic surges during the initial stages of the eruption. However, the most extensive service reduction across all networks occurs 6 days prior to the eruption onset, largely attributed to the

  2. Where is the UK's pollinator biodiversity? The importance of urban areas for flower-visiting insects.

    Science.gov (United States)

    Baldock, Katherine C R; Goddard, Mark A; Hicks, Damien M; Kunin, William E; Mitschunas, Nadine; Osgathorpe, Lynne M; Potts, Simon G; Robertson, Kirsty M; Scott, Anna V; Stone, Graham N; Vaughan, Ian P; Memmott, Jane

    2015-03-22

    Insect pollinators provide a crucial ecosystem service, but are under threat. Urban areas could be important for pollinators, though their value relative to other habitats is poorly known. We compared pollinator communities using quantified flower-visitation networks in 36 sites (each 1 km(2)) in three landscapes: urban, farmland and nature reserves. Overall, flower-visitor abundance and species richness did not differ significantly between the three landscape types. Bee abundance did not differ between landscapes, but bee species richness was higher in urban areas than farmland. Hoverfly abundance was higher in farmland and nature reserves than urban sites, but species richness did not differ significantly. While urban pollinator assemblages were more homogeneous across space than those in farmland or nature reserves, there was no significant difference in the numbers of rarer species between the three landscapes. Network-level specialization was higher in farmland than urban sites. Relative to other habitats, urban visitors foraged from a greater number of plant species (higher generality) but also visited a lower proportion of available plant species (higher specialization), both possibly driven by higher urban plant richness. Urban areas are growing, and improving their value for pollinators should be part of any national strategy to conserve and restore pollinators.

  3. Toward a Theory of Integrated Urban Ecology: Complementing Pickett et al.

    Directory of Open Access Journals (Sweden)

    Robert Mugerauer

    2010-12-01

    Full Text Available The analyses substantially delineating "integrative studies of large urban areas as bio-physical-social complexes" and the suggestions by Pickett et al. in "Beyond Urban Legends" (Bioscience 2008 58 139-150 provide an initial framework for a theory of urban ecology. This article intends to contribute to the project by: 1 improving the philosophical rigor of critical concepts and epistemologies; 2 making explicit the complementary theoretical and empirical work in urban ecology already being done that can be better integrated, for example, studies from outside the U.S. and uses of actor network theory; 3 bringing forward more disciplines and theories which successfully deploy modes of thinking, research procedures, and practices more adequate to the phenomena at all scales and levels of particularity, i.e., micro, phenomenal, macro, to fill in some of the empirical gaps in the middle, specifically those having to do with human values and the richness of the everyday lifeworld. In addition to what is available within complexity theory itself, chief among the approaches to be utilized are phenomenology, ethnographic thick description, and actor network theory.

  4. Efficient predictive model-based and fuzzy control for green urban mobility

    NARCIS (Netherlands)

    Jamshidnejad, A.

    2017-01-01

    In this thesis, we develop efficient predictive model-based control approaches, including model-predictive control (MPC) andmodel-based fuzzy control, for application in urban traffic networks with the aim of reducing a combination of the total time spent by the vehicles within the network and the

  5. Nonlinear Dynamics on Interconnected Networks

    Science.gov (United States)

    Arenas, Alex; De Domenico, Manlio

    2016-06-01

    Networks of dynamical interacting units can represent many complex systems, from the human brain to transportation systems and societies. The study of these complex networks, when accounting for different types of interactions has become a subject of interest in the last few years, especially because its representational power in the description of users' interactions in diverse online social platforms (Facebook, Twitter, Instagram, etc.) [1], or in representing different transportation modes in urban networks [2,3]. The general name coined for these networks is multilayer networks, where each layer accounts for a type of interaction (see Fig. 1).

  6. Third-world development: urbanizing for the future.

    Science.gov (United States)

    Mcilwaine, C

    1997-01-01

    This article reviews some issues reflected in the 1996 UN Habitat II agenda and recent research on urbanization. The themes of the 1996 Habitat conference were urban development, urban poverty, and governance, civil society, and social capital. It is expected that over 50% of total world population will live in cities in the year 2000. Cities are viewed both as engines of economic growth and centers of severe economic, environmental, and social problems. There is some disagreement about whether cities are rational economic structures or what the World Bank's urban agenda is and its relationship with macroeconomic policy. Discussions of global urban issues are criticized for their neglect of issues of equity and poverty, cultural diversity, and identity and representation. Habitat II also stressed urban sustainability. There is growing recognition that urban management involves more than the "Brown Agenda" of environmental and physical aspects of urban growth. Recent studies identify how politics and power affect people's access to basic urban services. Urban economic activity can also contribute to environmental problems. Urban growth affects the provision of health services. Although there is not a consensus on the role of cities in expanding economic and social development and the best management practices, there is sufficient evidence to indicate that urban processes are varied throughout the developing world. The links between urban and rural areas differentiate cities and expose the need to understand the role of intermediate urban areas surrounding and between larger cities. Poverty has become increasingly urbanized, but the extent of poverty is unknown. Habitat II was an unprecedented effort to engage nongovernment groups, local government staff, trade unions, and the private sector and to emphasize community participation. Networks of trust and reciprocity are key to solving poverty, inequality, and disempowerment problems.

  7. Optimization of municipal pressure pumping station layout and sewage pipe network design

    Science.gov (United States)

    Tian, Jiandong; Cheng, Jilin; Gong, Yi

    2018-03-01

    Accelerated urbanization places extraordinary demands on sewer networks; thus optimization research to improve the design of these systems has practical significance. In this article, a subsystem nonlinear programming model is developed to optimize pumping station layout and sewage pipe network design. The subsystem model is expanded into a large-scale complex nonlinear programming system model to find the minimum total annual cost of the pumping station and network of all pipe segments. A comparative analysis is conducted using the sewage network in Taizhou City, China, as an example. The proposed method demonstrated that significant cost savings could have been realized if the studied system had been optimized using the techniques described in this article. Therefore, the method has practical value for optimizing urban sewage projects and provides a reference for theoretical research on optimization of urban drainage pumping station layouts.

  8. Border detection in complex networks

    International Nuclear Information System (INIS)

    Travencolo, Bruno A N; Viana, Matheus Palhares; Costa, Luciano da Fontoura

    2009-01-01

    One important issue implied by the finite nature of real-world networks regards the identification of their more external (border) and internal nodes. The present work proposes a formal and objective definition of these properties, founded on the recently introduced concept of node diversity. It is shown that this feature does not exhibit any relevant correlation with several well-established complex networks measurements. A methodology for the identification of the borders of complex networks is described and illustrated with respect to theoretical (geographical and knitted networks) as well as real-world networks (urban and word association networks), yielding interesting results and insights in both cases.

  9. Evaluation of j-turn intersection design performance in Missouri, final report.

    Science.gov (United States)

    2013-12-01

    Research shows that a high percentage of crashes that take place on high-speed rural expressways occur at intersections : with minor roads. One low-cost alternative design for improving the safety of at-grade intersections on such expressways is : th...

  10. Evaluation of j-turn intersection design performance in Missouri.

    Science.gov (United States)

    2013-12-01

    Research shows that a high percentage of crashes that take place on high-speed rural expressways occur at intersections with : minor roads. One low-cost alternative design for improving the safety of at-grade intersections on such expressways is the ...

  11. Exploring space-time structure of human mobility in urban space

    Science.gov (United States)

    Sun, J. B.; Yuan, J.; Wang, Y.; Si, H. B.; Shan, X. M.

    2011-03-01

    Understanding of human mobility in urban space benefits the planning and provision of municipal facilities and services. Due to the high penetration of cell phones, mobile cellular networks provide information for urban dynamics with a large spatial extent and continuous temporal coverage in comparison with traditional approaches. The original data investigated in this paper were collected by cellular networks in a southern city of China, recording the population distribution by dividing the city into thousands of pixels. The space-time structure of urban dynamics is explored by applying Principal Component Analysis (PCA) to the original data, from temporal and spatial perspectives between which there is a dual relation. Based on the results of the analysis, we have discovered four underlying rules of urban dynamics: low intrinsic dimensionality, three categories of common patterns, dominance of periodic trends, and temporal stability. It implies that the space-time structure can be captured well by remarkably few temporal or spatial predictable periodic patterns, and the structure unearthed by PCA evolves stably over time. All these features play a critical role in the applications of forecasting and anomaly detection.

  12. The renaissance of tramways and urban redevelopment in France

    Directory of Open Access Journals (Sweden)

    Boquet Yves

    2017-03-01

    Full Text Available Tramways have made a remarkable comeback in France since the 1980s. An organization of public transport based on the decentralized administration system set up in the early 1980s has allowed local urban authorities to make their own choices to develop public transport networks in the context of automobile domination. As in many other countries, worries about fossil fuel dependency and demands concerning sustainable urban development appear as strong elements in favour of urban light rail. However, in France, tramways are not just technical solutions for traffic congestion, they have also become a symbol of a cultural mutation in urban development planning. Coupled with a national political push for a more inclusive city in social terms, tramways are the backbone of contemporary urban policies, in a French version of transit-oriented development (TOD, especially for mid-size cities.

  13. A Multilayer perspective for the analysis of urban transportation systems.

    Science.gov (United States)

    Aleta, Alberto; Meloni, Sandro; Moreno, Yamir

    2017-03-15

    Public urban mobility systems are composed by several transportation modes connected together. Most studies in urban mobility and planning often ignore the multi-layer nature of transportation systems considering only aggregated versions of this complex scenario. In this work we present a model for the representation of the transportation system of an entire city as a multiplex network. Using two different perspectives, one in which each line is a layer and one in which lines of the same transportation mode are grouped together, we study the interconnected structure of 9 different cities in Europe raging from small towns to mega-cities like London and Berlin highlighting their vulnerabilities and possible improvements. Finally, for the city of Zaragoza in Spain, we also consider data about service schedule and waiting times, which allow us to create a simple yet realistic model for urban mobility able to reproduce real-world facts and to test for network improvements.

  14. Detecting Development Pattern of Urban Business Facilities Using Reviews Data

    Directory of Open Access Journals (Sweden)

    JIANG Botao

    2015-09-01

    Full Text Available This paper reveals and utilizes the growing power of online customer reviews in the space and time context. The location of commercial facilities and online customer reviews offered by Dianping.com provide an important data source for the study of spatial and temporal dynamics of urban commercial facilities. The constraints of road network are taken into account towards computing the density of urban commercial facilities and associated online customer reviews, as well as their spatial distribution, temporal trend, and the coupling relationship between facility number and stratification level. This paper maps the spatial distribution of commercial facilities onto the nearby road network, reflecting the influences of the locations, number and satisfaction levels of other commercial facilities across various street types. Because more and more customers tend to make a final shopping decision by sorting through search results by ratings and feedback, the research conducted in this paper can provide the proof for quantitative evaluation of urban planning on commercial facility development.

  15. Networking: Addressing Urban Students' Self-Esteem.

    Science.gov (United States)

    Tobias, Randolf; Turner, Thomas M.

    1997-01-01

    Describes Network in the Schools (NIS), a project to enhance teens' academic achievement and self-esteem, which uses small group classroom discussions regarding self-affirmation, social concerns, self-improvement, and reflection, and meetings for group sharing and self-expression. Presents findings that the program results in enhanced parent…

  16. Spatio-temporal networks: reachability, centrality and robustness.

    Science.gov (United States)

    Williams, Matthew J; Musolesi, Mirco

    2016-06-01

    Recent advances in spatial and temporal networks have enabled researchers to more-accurately describe many real-world systems such as urban transport networks. In this paper, we study the response of real-world spatio-temporal networks to random error and systematic attack, taking a unified view of their spatial and temporal performance. We propose a model of spatio-temporal paths in time-varying spatially embedded networks which captures the property that, as in many real-world systems, interaction between nodes is non-instantaneous and governed by the space in which they are embedded. Through numerical experiments on three real-world urban transport systems, we study the effect of node failure on a network's topological, temporal and spatial structure. We also demonstrate the broader applicability of this framework to three other classes of network. To identify weaknesses specific to the behaviour of a spatio-temporal system, we introduce centrality measures that evaluate the importance of a node as a structural bridge and its role in supporting spatio-temporally efficient flows through the network. This exposes the complex nature of fragility in a spatio-temporal system, showing that there is a variety of failure modes when a network is subject to systematic attacks.

  17. Urban heat island research of Novi Sad (Serbia: A review

    Directory of Open Access Journals (Sweden)

    Savić Stevan

    2013-01-01

    Full Text Available In the second part of the 20th century, urbanization accelerated and reached enormous magnitude, which results more and more people live in urbanized regions. Nowadays, about half of the human population is affected by the burdens of urban environments and furthermore the modified parameters of the urban atmosphere compared to the natural environment. Novi Sad (45°15’N, 19°50’E is located in the northern part of Serbia, i.e. on the southern part of the Pannonian Plain and it is the second largest city in the country with a population of about 320,000 in a built-up area of approximately 80 km2. The geographical area is plain, from 80 to 86 m a.s.l., with a gentle relief, so its climate is free from orographic effects. According to Köppen-Geiger climate classification, this region is categorised as Cfa climate (temperate warm climate with a rather uniform annual distribution of precipitation. In the last 20 years, a few papers have been published considering urban heat island (UHI investigations of Novi Sad. The first publication in 1994 is theoretically based and presents all parameters, methods and measurements, which have to be used in order to work on UHI research of Novi Sad. The next studies from 1995 and 2006 analyzed various temperature parameters based on 30-40 year long time series and used rural and urban stations in order to get urban-rural temperature differences. Based on meteorological parameters and the structure of urban area, in 2010 the necessity of defining locations of an urban climate network was showed in order to advance further UHI research. In the last two publications from 2011 a new empirical modeling method, adjusted for cities located on plains, has been used in order to determine locations for representative stations of an urban climate network in Novi Sad.

  18. REVIEW OF THE EUROPEAN SYSTEMS RESEARCH PROGRAMS OF URBAN TERRITORIES

    Directory of Open Access Journals (Sweden)

    L. N. Kovalskyi

    2017-01-01

    Full Text Available The model of sustainable development of the territory should be in a state of control and management. The system of urban monitoring of Ukraine does not fully provide information on the level of sustainable development of settlements and regions. Therefore, it is necessary to create systems for monitoring indicators of sustainable development of human settlements and regions. The objective of this study is to analyze the existing programs for stimulating sustainable development in European countries and to develop recommendations on the need to organize such systems in Ukraine and to improve the system of urban monitoring. The article describes such systems and programs: URBACT is a program for sharing best practices between cities by creating thematic networks. URBACT’s mission is to encourage cities to work together and develop integrated solutions to common urban problems, through networking, to learn from each other’s experiences and identify best practices in order to improve urban policies; URBAN AUDIT – a large set of statistical information. The main objective of the system is to provide objective and comparable statistical data on European cities; URBAN ATLAS – provides a pan-European comparison of urban land use data. The information is in the form of open geospatial data. The system is aimed at facilitating work on site planning and site accounting. It is necessary to adopt the best practices of implementing sustainable development technology and apply it in other countries that have chosen a model for their development – a model for sustainable development of the territory. The current system of town-planning monitoring in Ukraine needs to be improved and given a new task – to take into account indicators of sustainable development of the territories. This system is most suitable for this task, since urban monitoring already takes into account certain indicators in the form of spatial data.

  19. Determinants of Network Outcomes

    DEFF Research Database (Denmark)

    Ysa, Tamyko; Sierra, Vicenta; Esteve, Marc

    2014-01-01

    The literature on network management is extensive. However, it generally explores network structures, neglecting the impact of management strategies. In this article we assess the effect of management strategies on network outcomes, providing empirical evidence from 119 urban revitalization...... networks. We go beyond current work by testing a path model for the determinants of network outcomes and considering the interactions between the constructs: management strategies, trust, complexity, and facilitative leadership. Our results suggest that management strategies have a strong effect on network...... outcomes and that they enhance the level of trust. We also found that facilitative leadership has a positive impact on network management as well as on trust in the network. Our findings also show that complexity has a negative impact on trust. A key finding of our research is that managers may wield more...

  20. Mobility and power in networked European space

    DEFF Research Database (Denmark)

    Richardson, Tim; Jensen, Ole B.

    This paper seeks to contribute to debates about how urban, social and critical theory can conceptualise the socio-technologies of connection, resilience, mobility, and collapse in contemporary urban space. The paper offers a theoretical frame for conceptualising this New Urban Condition, focusing...... on themes of mobility, power, flow, network and scale. The analysis suggests the importance of close atention to the knowledge claims which are deployed in multi-level struggles to assert smooth futures in face of dysfunction....

  1. Smart thermal networks for smart cities – Introduction of concepts and measures

    Directory of Open Access Journals (Sweden)

    Basciotti D.

    2012-10-01

    Full Text Available In order to contribute to high living standards, climate mitigation and energy supply security, future urban energy systems require a holistic approach. In particular an intelligent integration of thermal networks is necessary. This paper will briefly present the “smart city” concept and introduce an associated definition for smart thermal networks defined on three levels: 1. the interaction with urban planning processes and the interface to the overall urban energy system, 2. the adaptation of the temperature level and 3. supply and demand-side management strategies.

  2. Understanding congested travel in urban areas

    Science.gov (United States)

    Çolak, Serdar; Lima, Antonio; González, Marta C.

    2016-03-01

    Rapid urbanization and increasing demand for transportation burdens urban road infrastructures. The interplay of number of vehicles and available road capacity on their routes determines the level of congestion. Although approaches to modify demand and capacity exist, the possible limits of congestion alleviation by only modifying route choices have not been systematically studied. Here we couple the road networks of five diverse cities with the travel demand profiles in the morning peak hour obtained from billions of mobile phone traces to comprehensively analyse urban traffic. We present that a dimensionless ratio of the road supply to the travel demand explains the percentage of time lost in congestion. Finally, we examine congestion relief under a centralized routing scheme with varying levels of awareness of social good and quantify the benefits to show that moderate levels are enough to achieve significant collective travel time savings.

  3. Global Optimization for Transport Network Expansion and Signal Setting

    OpenAIRE

    Liu, Haoxiang; Wang, David Z. W.; Yue, Hao

    2015-01-01

    This paper proposes a model to address an urban transport planning problem involving combined network design and signal setting in a saturated network. Conventional transport planning models usually deal with the network design problem and signal setting problem separately. However, the fact that network capacity design and capacity allocation determined by network signal setting combine to govern the transport network performance requires the optimal transport planning to consider the two pr...

  4. DOD Eye Sensors to Give 'Urban Canyon Visibility

    National Research Council Canada - National Science Library

    Bender, Bryan

    2000-01-01

    Washington DC -- The US Department of Defense (DoD) is considering supplying troops with low-cost, disposable hand-held sensors that can be flised into an intelligence network accessible at the lowest levels on the future urban battlefield...

  5. Rerouting Urban Waters: A Historic Examination of the Age of Imperviousness

    Science.gov (United States)

    Hopkins, K. G.; Bain, D. J.

    2011-12-01

    From the 1600's to the 1900's landscapes along the Eastern United States underwent dramatic changes, including transitions from forest to production agriculture and eventually urban development. Legacy effects from decisions on sewer and water infrastructure built during the early 1900's are emerging today in degraded urban waterways. Impervious cover is often a factor used to predict water impairment. However, does imperviousness age or change through the course of landscape evolution? This study reconstructs the history of imperviousness in the Panther Hollow watershed (161 ha, Pittsburgh, PA) to examine these changes. We reconstruct the importance of factors influencing effective imperviousness from the 1800's to present including; (1) pipe and road network technological transitions, (2) land cover changes, particularly the loss of forest cover, and (3) modifications to local topography. Analysis reveals effective imperviousness (impervious area in the basin directly connected to stream channels) increased dramatically after 1900. Prior to 1900, water and sewer infrastructure was very limited. Local drainage networks generally followed the natural topography and households accessed water supplies from wells, precipitation harvesting or surface water. Road networks were sparse and predominantly dirt or aggregate surfaces. Forests and large family farms dominated land cover. Around 1910 public water supply expanded, significantly increasing effective imperviousness due to installation of brick and ceramic sewer infrastructure that routed waste waters directly to stream channels. Road networks also expanded and began transitioning from dirt roads to brick and eventually asphalt. Shifting to impervious paving materials required the installation of stormwater drainage. New drainage systems altered historic flow paths by re-routed large quantities of water through macro-pore sewer networks to local waterways. While this improvement prevented flooding to roadways, it

  6. Adaptive governance to promote ecosystem services in urban ...

    Science.gov (United States)

    Managing urban green space as part of an ongoing social-ecological transformationposes novel governance issues, particularly in post-industrial settings. Urban green spaces operate as small-scale nodes in larger networks of ecological reserves that provide and maintain key ecosystem services such as pollination, water retention and infiltration, and sustainable food production. In an urban mosaic, a myriad of social and ecological components factor into aggregating and managing land to maintain or increase the flow of ecosystem services associated with green spaces. Vacant lots (a form of urban green space) are being repurposed for multiple functions, such as habitat for biodiversity, including arthropods that provide pollination services to other green areas; to capture urban runoff that eases the burden on ageing wastewater systems and other civic infrastructure; and to reduce urban heat island effects. Urban green spaces provide vital ecosystem services at varying degrees, depending on the size, function, and management of these spaces. Governance of linked social-ecological systems to maximize those services poses unique challenges given the uncertainty of ecological responses and the social political complexity of managing ecological resources in an urban context where fiscal and human resources are strained. In North America, many cities are facing fiscal austerity because of shrinkage in manufacturing and industrial sectors and the foreclosure crisis. As

  7. EMERGING CITIES ON THE ARABIAN PENINSULA: URBAN SPACE IN THE KNOWLEDGE ECONOMY CONTEXT

    Directory of Open Access Journals (Sweden)

    Alain Thierstein

    2008-07-01

    Full Text Available Networks of the growing knowledge economy significantly influence spatial development on different scales. This paper proposes a framework for analyzing the impact of global knowledge economy networks on the rapidly developing urban space of emerging cities on the Arabian Peninsula, and vice versa. Two aspects of the described research are innovative: First, a global relational geography-perspective builds the basis for approaching the analysis of urban space development in emerging cities on the Arabian Peninsula. Second, the empirical methodology of the research project is a newly defined method triangulation, setting an example for systematic analysis of local urban development in a global context. The method triangulation combines three different research angles: A knowledge economy firm perspective, an on-site observation perspective and a planner perspective. The method triangulation defines the procedure for the research application in selected case study cities on the Arabian Peninsula. Initial results from applying the research methodology in the city of Dubai give a first indication, that emerging cities on the Arabian Peninsula play a significant role in the global and regional knowledge economy networks. Locally developed urban spaces reflect and influence the significance of cities in the global knowledge economy context. Especially the global visibility of urban spaces on a city district scale, which specifically address the needs of knowledge economy players, contributes significantly to the attractiveness of emerging cities on the Arabian Peninsula.

  8. Modelling Pollutant Dispersion in a Street Network

    Science.gov (United States)

    Salem, N. Ben; Garbero, V.; Salizzoni, P.; Lamaison, G.; Soulhac, L.

    2015-04-01

    This study constitutes a further step in the analysis of the performances of a street network model to simulate atmospheric pollutant dispersion in urban areas. The model, named SIRANE, is based on the decomposition of the urban atmosphere into two sub-domains: the urban boundary layer, whose dynamics is assumed to be well established, and the urban canopy, represented as a series of interconnected boxes. Parametric laws govern the mass exchanges between the boxes under the assumption that the pollutant dispersion within the canopy can be fully simulated by modelling three main bulk transfer phenomena: channelling along street axes, transfers at street intersections, and vertical exchange between street canyons and the overlying atmosphere. Here, we aim to evaluate the reliability of the parametrizations adopted to simulate these phenomena, by focusing on their possible dependence on the external wind direction. To this end, we test the model against concentration measurements within an idealized urban district whose geometrical layout closely matches the street network represented in SIRANE. The analysis is performed for an urban array with a fixed geometry and a varying wind incidence angle. The results show that the model provides generally good results with the reference parametrizations adopted in SIRANE and that its performances are quite robust for a wide range of the model parameters. This proves the reliability of the street network approach in simulating pollutant dispersion in densely built city districts. The results also show that the model performances may be improved by considering a dependence of the wind fluctuations at street intersections and of the vertical exchange velocity on the direction of the incident wind. This opens the way for further investigations to clarify the dependence of these parameters on wind direction and street aspect ratios.

  9. Representing soakaways in a physically distributed urban drainage model – Upscaling individual allotments to an aggregated scale

    DEFF Research Database (Denmark)

    Roldin, Maria Kerstin; Mark, Ole; Kuczera, George

    2012-01-01

    the infiltration rate based on water depth and soil properties for each time step, and controls the removal of water from the urban drainage model. The model is intended to be used to assess the impact of soakaways on urban drainage networks. The model is tested using field data and shown to simulate the behavior......The increased load on urban stormwater systems due to climate change and growing urbanization can be partly alleviated by using soakaways and similar infiltration techniques. However, while soakaways are usually small-scale structures, most urban drainage network models operate on a larger spatial...... of individual soakaways well. Six upscaling methods to aggregate individual soakaway units with varying saturated hydraulic conductivity (K) in the surrounding soil have been investigated. In the upscaled model, the weighted geometric mean hydraulic conductivity of individual allotments is found to provide...

  10. Urban Quality Development & Management

    DEFF Research Database (Denmark)

    Lehmann, Martin; Fryd, Ole

    2008-01-01

    Purpose: The purpose of this article is to describe and discuss the development and the structure of a new international master on the subject of Urban Quality Development & Management, and explore the potential of the process and the outcome in serving as models adoptable by faculty at other......: Urban quality development and management is dependent on human resource development, institutionalised networks and confident exchange of knowledge, and must identify and incorporate multiple environmental, social, economic and cultural aspects. The authors find that at the core of innovative societies......, an interlinkage exists between practice (business, civil society, governance) and theory (research, education). The case illustrates how a new curriculum takes time to develop and implement and how it relies on confidence and trust between partners, in this case cities and universities, before being able to plant...

  11. Green urbanity

    Directory of Open Access Journals (Sweden)

    Alenka Fikfak

    2012-01-01

    Full Text Available Tourism and other culture-based types of small business, which are the leitmotif in the planning of the Europark Ruardi, are becoming the guiding motif in the spatial development of urban centres that are influenced by dynamic transformation processes. The system should build upon the exploitation of both local and regional environmental features. This would encourage the quest for special environmental features, with an emphasis on their conservation, i.e. sustainable development, and connections in a wider context.The Europark is seen as a new strategic point of the Zasavje Region (the region of the central Sava Valley, which is linked to other important points in a region relevant for tourism. Due to the "smallness" of the region and/or the proximity of such points, development can be fast and effective. The interaction of different activities in space yields endless opportunities for users, who choose their own goals and priorities in the use of space. Four theme areas of the Europark area planning are envisaged. The organisation of activities is based on the composition of the mosaic field patterns, where green fields intertwine with areas of different, existing and new, urban functions. The fields of urban and recreation programmes are connected with a network of green areas and walking trails, along which theme park settings are arranged.

  12. An Empirical Study on Transit-Oriented Low-Carbon Urban Land Use Planning

    DEFF Research Database (Denmark)

    Dou, Yi; Luo, Xiao; Dong, Liang

    2016-01-01

    Low-carbon urban development is a hot spot of global concerns for fighting against climate change for China, transportation sector has a significant contribution to urban CO2 emissions, while the emissions are still increasing. Transit-Oriented Development (TOD) strategies provide a novel approach...... for urban planners to facilitate the urban carbon mitigation from transportation sector in long-term. While TOD strategies are emerging cases, they are merely qualitatively discussed in China, lacking practical indicators and quantitative verification for supporting the real urban plan...... population and transportation accessibility with Geographic Weighted Regression model. Results highlight that TOD can effectively improve the transportation network with higher accessibility and lower urban carbon emissions. The outcomes of this study provide critical insights to the recent practice...

  13. Social Networks and Health Knowledge in India

    DEFF Research Database (Denmark)

    Blunch, Niels-Hugo; Datta Gupta, Nabanita

    such as education and access to social networks explain part of the gap, a substantial part of the health knowledge gap is left unexplained. All groups have greater health knowledge in urban than in rural areas, but the gap is even wider in urban than in rural areas. Additionally, high caste women benefit more...... in terms of health knowledge from having health networks than women from other groups; except if the health person is of the same caste/religion, in which case low caste and Muslim women sometimes benefit by as much as double that of high caste women, or even more. It may therefore not be enough to give...... individuals access to high quality networks if caste and religion-related gaps in health knowledge are to be reduced; such networks also have to be homophilous, to have the maximum effect. Improved treatment from and confidence in the medical profession is found to be part of the mechanism linking health...

  14. Introducing a Method for Social-ecological Assessment of Small Urban Parks

    Directory of Open Access Journals (Sweden)

    Zanariah Jasman

    2016-06-01

    Full Text Available Small parks in cities are important to support overall urban biodiversity and ecological network. The aim of this paper is to introduce a method of identifying and assessing the ecological characteristics and anthropogenic factors of small urban parks. We developed a framework that combined structured observation and field measurement. The method suggests an integrative assessment that is practical and understandable to the park planners and managers to enhance small parks to support overall urban biodiversity and ecosystem services. High biodiversity can provide opportunities for humans to experience nature and wildlife in cities, thus contributing to the quality of life of urban dwellers.

  15. Case Study: Does training of private networks of Family Planning clinicians in urban Pakistan affect service utilization?

    Science.gov (United States)

    2010-01-01

    Background To determine whether training of providers participating in franchise clinic networks is associated with increased Family Planning service use among low-income urban families in Pakistan. Methods The study uses 2001 survey data consisting of interviews with 1113 clinical and non-clinical providers working in public and private hospitals/clinics. Data analysis excludes non-clinical providers reducing sample size to 822. Variables for the analysis are divided into client volume, and training in family planning. Regression models are used to compute the association between training and service use in franchise versus private non-franchise clinics. Results In franchise clinic networks, staff are 6.5 times more likely to receive family planning training (P = 0.00) relative to private non-franchises. Service use was significantly associated with training (P = 0.00), franchise affiliation (P = 0.01), providers' years of family planning experience (P = 0.02) and the number of trained staff working at government owned clinics (P = 0.00). In this setting, nurses are significantly less likely to receive training compared to doctors (P = 0.00). Conclusions These findings suggest that franchises recruit and train various cadres of health workers and training maybe associated with increased service use through improvement in quality of services. PMID:21062460

  16. Case Study: Does training of private networks of Family Planning clinicians in urban Pakistan affect service utilization?

    Directory of Open Access Journals (Sweden)

    Qureshi Asma M

    2010-11-01

    Full Text Available Abstract Background To determine whether training of providers participating in franchise clinic networks is associated with increased Family Planning service use among low-income urban families in Pakistan. Methods The study uses 2001 survey data consisting of interviews with 1113 clinical and non-clinical providers working in public and private hospitals/clinics. Data analysis excludes non-clinical providers reducing sample size to 822. Variables for the analysis are divided into client volume, and training in family planning. Regression models are used to compute the association between training and service use in franchise versus private non-franchise clinics. Results In franchise clinic networks, staff are 6.5 times more likely to receive family planning training (P = 0.00 relative to private non-franchises. Service use was significantly associated with training (P = 0.00, franchise affiliation (P = 0.01, providers' years of family planning experience (P = 0.02 and the number of trained staff working at government owned clinics (P = 0.00. In this setting, nurses are significantly less likely to receive training compared to doctors (P = 0.00. Conclusions These findings suggest that franchises recruit and train various cadres of health workers and training maybe associated with increased service use through improvement in quality of services.

  17. Case Study: Does training of private networks of Family Planning clinicians in urban Pakistan affect service utilization?

    Science.gov (United States)

    Qureshi, Asma M

    2010-11-09

    To determine whether training of providers participating in franchise clinic networks is associated with increased Family Planning service use among low-income urban families in Pakistan. The study uses 2001 survey data consisting of interviews with 1113 clinical and non-clinical providers working in public and private hospitals/clinics. Data analysis excludes non-clinical providers reducing sample size to 822. Variables for the analysis are divided into client volume, and training in family planning. Regression models are used to compute the association between training and service use in franchise versus private non-franchise clinics. In franchise clinic networks, staff are 6.5 times more likely to receive family planning training (P = 0.00) relative to private non-franchises. Service use was significantly associated with training (P = 0.00), franchise affiliation (P = 0.01), providers' years of family planning experience (P = 0.02) and the number of trained staff working at government owned clinics (P = 0.00). In this setting, nurses are significantly less likely to receive training compared to doctors (P = 0.00). These findings suggest that franchises recruit and train various cadres of health workers and training maybe associated with increased service use through improvement in quality of services.

  18. Integrated policy analysis of sustainable urban and transportation development

    NARCIS (Netherlands)

    Zhang, J.; Feng, T.; Fujiwara, A.; Fujiwara, A.; Zhang, Junyi

    2013-01-01

    Sustainable urban and transportation development needs to balance economic sustainability, environmental sustainability, and social equity. This study conducts integrated policy analyses by explicitly incorporating these sustainability goals and optimizing the performance of transportation networks.

  19. Spatial characterization of catchment dispersion mechanisms in an urban context

    Science.gov (United States)

    Rossel, Florian; Gironás, Jorge; Mejía, Alfonso; Rinaldo, Andrea; Rodriguez, Fabrice

    2014-12-01

    Previous studies have examined in-depth the dispersion mechanisms in natural catchments. In contrast, these dispersion mechanisms have been studied little in urban catchments, where artificial transport elements and morphological arrangements are expected to modify travel times and mobilize excess rainfall from spatially distributed impervious sites. This has the ability to modify the variance of the catchment's travel times and hence the total dispersion. This work quantifies the dispersion mechanisms in an urban catchment using the theory of transport by travel times as represented by the Urban Morpho-climatic Instantaneous Unit Hydrograph (U-McIUH) model. The U-McIUH computes travel times based on kinematic wave theory and accounts explicitly for the path heterogeneities and altered connectivity patterns characteristic of an urban drainage network. The analysis is illustrated using the Aubinière urban catchment in France as a case study. We found that kinematic dispersion is dominant for small rainfall intensities, whereas geomorphologic dispersion becomes more dominant for larger intensities. The total dispersion scales with the drainage area in a power law fashion. The kinematic dispersion is dominant across spatial scales up to a threshold of approximately 2-3 km2, after which the geomorphologic dispersion becomes more dominant. Overall, overland flow is responsible for most of the dispersion in the catchment, while conduits tend to counteract the increase of the geomorphologic dispersion with a negative kinematic dispersion. Further study with other catchments is needed to asses if the latter is a general feature of urban drainage networks.

  20. Growing Better Cities: Urban Agriculture for Sustainable Development

    International Development Research Centre (IDRC) Digital Library (Canada)

    As the cities grow, so does the number of urban poor. ... Case studies: ... It describes the growth of city networks in Africa and Latin America that focus on ... partners will showcase critical work on adaptation and resilience in hot spot regions.

  1. Why is child malnutrition lower in urban than rural areas?

    OpenAIRE

    Smith, Lisa C.; Ruel, Marie T.; Ndiaye, Aida

    2004-01-01

    "While ample evidence documents that urban children generally have better nutritional status than their rural counterparts, recent research suggests that urban malnutrition is on the rise. The environment, choices, and opportunities of urbanites differ greatly from those of rural dwellers' from employment conditions to social and family networks to access to health care and other services. Given these differences, understanding the relative importance of the various determinants of child maln...

  2. : Urban design, urban project, urban art, urban composition ... a question of vocabulary?

    OpenAIRE

    Pinson , Daniel

    2014-01-01

    Actes à paraître; International audience; The term "urbanism" of Pierre Clerget (1910) put the mess in the practice and the formations in France. Urban planning is thus, on the academic level, a coexistence of disciplinary approaches, which does not help to a multidisciplinary urban training. Thinking about "urban design", after beautifull city, urban composition, or alongside the urban project and other territorial approaches can help to see more clearly in town planning.; Le terme « urbanis...

  3. Entrepreneurship within Urban and Rural Areas

    DEFF Research Database (Denmark)

    Freire-Gibb, L. Carlos; Nielsen, Kristian

    2014-01-01

    The entrepreneurial dynamics of urban and rural areas are different, and this paper explores creativity and social networks factors in both places. The probabilities of becoming an entrepreneur and of surviving are analyzed. The results are based on longitudinal data combined with a questionnaire......, common entrepreneurship beliefs can be questioned and entrepreneurship theory benefited....

  4. Model Predictive Control of Sewer Networks

    DEFF Research Database (Denmark)

    Pedersen, Einar B.; Herbertsson, Hannes R.; Niemann, Henrik

    2016-01-01

    The developments in solutions for management of urban drainage are of vital importance, as the amount of sewer water from urban areas continues to increase due to the increase of the world’s population and the change in the climate conditions. How a sewer network is structured, monitored and cont...... benchmark model. Due to the inherent constraints the applied approach is based on Model Predictive Control....

  5. Urban resilience: Helping vulnerable city dwellers adapt to climate ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-03-06

    Mar 6, 2018 ... As cities expand, climate change compounds the stress on poor communities that already ... Ensure that our research partners are engaging with the best international networks on urban climate ... Siblings paddling to school.

  6. Implications of groundwater quality to corrosion problem and urban ...

    African Journals Online (AJOL)

    Bheema

    Surface and groundwater chemistry being an important factor in urban ... a network of pipes, conduits, metallic rods, reinforced concrete footings and other ... the WNW running fault belts (Wukro, Mekelle, Chelekot and Felega Mariam) and Rift.

  7. Evaluation of Seasonality in Shallow Groundwater Dynamics and Storage in an Urban Prairie Nature Preserve Using a High-Frequency Sensing Network

    Science.gov (United States)

    Rivera, V. A.; Hernandez-Gonzalez, L. M.; Phillips, C. B.; Nair, A.; Negri, M. C.; Gnaedinger, K. J.; Miller, W. M.; Packman, A. I.

    2017-12-01

    Changing regional climate applies stresses to urban areas in the form of altered weather patterns, requiring new strategies for stormwater runoff management and flood mitigation. At the same time, the proportion of people residing in urban areas is increasing and cities are turning to greenspace as a tool for managing runoff. Gensburg Markham Prairie (GMP), located in Markham, Illinois south of Chicago, is an urban prairie nature preserve and a U.S. National Natural Landmark. Owned by Northeastern Illinois University and managed by the Nature Conservancy, GMP receives runoff from surrounding urban areas and provides valuable stormwater storage, while also hosting high biodiversity and providing critical habitat for sensitive and endemic. A successful management strategy for GMP should preserve both of these valuable ecosystem services. To understand GMP's role within the urban environment, we installed a suite of instruments in 2016 and 2017 to measure surface and groundwater levels, rainfall, soil moisture, and electrical conductivity throughout the prairie. This monitoring network includes 40 sensors collecting high frequency data (every 30 minutes). We are also collecting monthly distributed surface and groundwater samples to quantify a range of anions and cations that signal potentially detrimental anthropogenic impacts on the prairie. In addition, we are using historical and ongoing plant distribution surveys to explore the interactions between spatial patterns in vegetation and water dynamics in the prairie. The high measurement frequency and large diversity of sensor types supports holistic investigation of the response of the prairie to diverse events, including summer thunderstorms, winter road salt runoff, and spring snowmelt. The 18 months of data collected to date reveals clear patterns in response to weather events with influence from soil type and spatial variables. We are using time-series analysis with MODFLOW modelling to explore surface

  8. Three-dimensional slum urban reconstruction in Envisat and Google Earth Egypt

    Science.gov (United States)

    Marghany, M.; Genderen, J. v.

    2014-02-01

    This study aims to aim to investigate the capability of ENVISAT ASAR satellite and Google Earth data for three-dimensional (3-D) slum urban reconstruction in developed country such as Egypt. The main objective of this work is to utilize 3-D automatic detection algorithm for urban slum in ENVISAT ASAR and Google Erath images were acquired in Cairo, Egypt using Fuzzy B-spline algorithm. The results show that fuzzy algorithm is the best indicator for chaotic urban slum as it can discriminate them from its surrounding environment. The combination of Fuzzy and B-spline then used to reconstruct 3-D of urban slam. The results show that urban slums, road network, and infrastructures are perfectly discriminated. It can therefore be concluded that fuzzy algorithm is an appropriate algorithm for chaotic urban slum automatic detection in ENVSIAT ASAR and Google Earth data.

  9. Three-dimensional slum urban reconstruction in Envisat and Google Earth Egypt

    International Nuclear Information System (INIS)

    Marghany, M; Genderen, J v

    2014-01-01

    This study aims to aim to investigate the capability of ENVISAT ASAR satellite and Google Earth data for three-dimensional (3-D) slum urban reconstruction in developed country such as Egypt. The main objective of this work is to utilize 3-D automatic detection algorithm for urban slum in ENVISAT ASAR and Google Erath images were acquired in Cairo, Egypt using Fuzzy B-spline algorithm. The results show that fuzzy algorithm is the best indicator for chaotic urban slum as it can discriminate them from its surrounding environment. The combination of Fuzzy and B-spline then used to reconstruct 3-D of urban slam. The results show that urban slums, road network, and infrastructures are perfectly discriminated. It can therefore be concluded that fuzzy algorithm is an appropriate algorithm for chaotic urban slum automatic detection in ENVSIAT ASAR and Google Earth data

  10. Solving local problems through local involvement? Experiences from Danish Urban Regeneration

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole

    -down approaches or massive public subsidies, the public regeneration schemes from the last decade have increasingly emphasized the need for involving local actors in the urban regeneration e.g. through partnerships, network building, involvement and participation of local actors and institutions, and financially...... agenda, and what can be learned from the development so far. Although ‘local involvement’ is a commonly used term in various urban regeneration programs, it can have many different meanings and implications. Therefore, the paper will discuss local involvement in the urban regeneration based on four...

  11. [Contribution of migrations to the process of urbanization].

    Science.gov (United States)

    Bocquier, P

    1997-10-01

    An average of 22% of the populations of the Sahel countries resided in urban areas in the mid-1970s, a lower level than in the rest of sub-Saharan Africa. The proportion urban has increased by about 5.5% annually over the past 2 decades. By 1993, four Sahel countries had over 30% of their populations in urban areas, and only Burkina Faso had less than 20% urban. The landlocked Sahel countries of Burkina Faso, Mali, Niger, and Chad have maintained rates of urbanization comparable to those of the coastal countries (Cape Verde, Gambia, Mauritania, and Senegal), which had more significant levels of urbanization in the past. The rate of growth of the urban population of all of sub-Saharan Africa was around 5.0% during the past 20 years. Only Dakar among the Sahel capitals has a population of over 1 million. Cities are small, and the urban environment is usually limited to the capital. In Guinea-Bissau, for example, the capital concentrates nearly 85% of the urban population. The increased rates of urbanization are due mainly to migration. In the landlocked countries covered by surveys of the Migration and Urbanization Networks in Western Africa (Burkina Faso, Mali, and Niger), the rural exodus was directed primarily to other countries. In Senegal and Mauritania, on the other hand, around two-thirds of migrations were internal. Women contribute more than men to urban growth in the Sahel. Returning migrants also show a strong preference for capital cities. Labor markets are international for men but national for women. Urban unemployment rates in the Sahel countries studied were lower for migrants than nonmigrants.

  12. Urban Ecology and Transformation of Technical Infrastructure

    DEFF Research Database (Denmark)

    Nielsen, Susanne Balslev

    1999-01-01

    -down strategies instead of seeing such strategies as incompatible. Today´s planning practice and the momentum of the established systems require new forums for stratgic debates if urban ecology is to be included in future network management. A methodolgy is presented for structuring a debate on future sustainable...

  13. NETWORKING - THE URBAN AND REGIONAL DEVELOPMENT STRATEGY?

    Directory of Open Access Journals (Sweden)

    PIOTR PACHURA

    2008-01-01

    Full Text Available It has become more and more common to claim that the concept of innovations embraces everything that is connected with creation and application of new knowledge in order to win competitive advantage. In this respect innovations concern as well, apart from technology, economy, society and culture. A traditional approach applied by organizational and management sciences is not enough to explain and manage the development of enterprises as well as that of cities, regions and countries. Simultaneously, according to a new approach to innovativeness, creation of innovations depends on a complex/system approach. The word complex is vital since this approach should embrace the complexity of innovative networks as well as complexity of relations of cooperation and the whole network environment together with social context.

  14. The role of storm scale, position and movement in controlling urban flood response

    Science.gov (United States)

    ten Veldhuis, Marie-claire; Zhou, Zhengzheng; Yang, Long; Liu, Shuguang; Smith, James

    2018-01-01

    The impact of spatial and temporal variability of rainfall on hydrological response remains poorly understood, in particular in urban catchments due to their strong variability in land use, a high degree of imperviousness and the presence of stormwater infrastructure. In this study, we analyze the effect of storm scale, position and movement in relation to basin scale and flow-path network structure on urban hydrological response. A catalog of 279 peak events was extracted from a high-quality observational dataset covering 15 years of flow observations and radar rainfall data for five (semi)urbanized basins ranging from 7.0 to 111.1 km2 in size. Results showed that the largest peak flows in the event catalog were associated with storm core scales exceeding basin scale, for all except the largest basin. Spatial scale of flood-producing storm events in the smaller basins fell into two groups: storms of large spatial scales exceeding basin size or small, concentrated events, with storm core much smaller than basin size. For the majority of events, spatial rainfall variability was strongly smoothed by the flow-path network, increasingly so for larger basin size. Correlation analysis showed that position of the storm in relation to the flow-path network was significantly correlated with peak flow in the smallest and in the two more urbanized basins. Analysis of storm movement relative to the flow-path network showed that direction of storm movement, upstream or downstream relative to the flow-path network, had little influence on hydrological response. Slow-moving storms tend to be associated with higher peak flows and longer lag times. Unexpectedly, position of the storm relative to impervious cover within the basins had little effect on flow peaks. These findings show the importance of observation-based analysis in validating and improving our understanding of interactions between the spatial distribution of rainfall and catchment variability.

  15. Pathogen and nutrient pulsing and attenuation in "accidental" urban wetland networks along the Salt River in Phoenix, AZ

    Science.gov (United States)

    Palta, M. M.; Grimm, N. B.

    2013-12-01

    Increases in available nutrients and bacteria in urban streams are at the forefront of research concerns within the ecological and medical communities, and both pollutants are expected to become more problematic under projected changes in climate. Season, discharge, instream conditions (oxygen, water velocity), and weather conditions (antecedent moisture) all may influence loading rates to and the retention capabilities of wetlands fed by urban runoff and storm flow. The aim of this research was to examine the effect of these variables on nutrient (nitrogen, phosphorus) and Escherichia coli (E. coli) loading and attenuation along flow paths in urban wetland networks along the Salt River in Phoenix, AZ. Samples were collected for one year along flowpaths through wetlands that formed below six perennially flowing outfalls. Collection took place monthly during baseflow (dry season) conditions, and before and immediately following storm events, in the summer monsoon and winter rainy seasons. Water quality was assessed at the following points: immediately downstream of the outfall, mid-wetland, and downstream of the wetland. For determination of E. coli counts, samples were plated on coliform-selective media (Chromocult) and incubated for 24 hours. Plates were then used to enumerate E. coli. For determination of nutrient concentrations, samples were filtered and frozen until they could be analyzed by ion chromatography and automated wet chemistry. During both summer and winter, total discharge into the wetlands increased during storm events. Concentrations of PO43+, NH4+, and E. coli were significantly higher following storm events than during baseflow conditions, and post-storm peaks in concentration ('pulses') were higher during the summer monsoon than in winter storms. Pulses of pollutants during storms were highest when preceded by hot, dry conditions. NO3- was high in both base and stormflow. E. coli counts and nutrient concentrations dropped along flowpaths

  16. ARTICULATED MODES OF INTEGRATION: THE STRUCTURING OF THE EUROPEAN URBAN SYSTEM

    OpenAIRE

    Rozenblat, Céline; Pumain, Denise

    2008-01-01

    European integration is for its essential part reflected in the building of urban networks that are increasing interdependencies between cities. Evidence of this process is brought through the observation of a variety of networks whose nodes are located in cities, especially the development of international functions. Analysis of airlines networks (2000) as well as the economic linkages between multinational firms (1990,1996) provide a good illustration reflecting the dominant features of suc...

  17. Community Based Networks and 5G

    DEFF Research Database (Denmark)

    Williams, Idongesit

    2016-01-01

    The deployment of previous wireless standards has provided more benefits for urban dwellers than rural dwellers. 5G deployment may not be different. This paper identifies that Community Based Networks as carriers that deserve recognition as potential 5G providers may change this. The argument....... The findings indicate that 5G connectivity can be extended to rural areas by these networks, via heterogenous networks. Hence the delivery of 5G data rates delivery via Wireless WAN in rural areas can be achieved by utilizing the causal factors of the identified models for Community Based Networks....

  18. A Meta-Analysis of Urban Climate Change Adaptation ...

    Science.gov (United States)

    The concentration of people, infrastructure, and ecosystem services in urban areas make them prime sites for climate change adaptation. While advances have been made in developing frameworks for adaptation planning and identifying both real and potential barriers to action, empirical work evaluating urban adaptation planning processes has been relatively piecemeal. Existing assessments of current experience with urban adaptation provide necessarily broad generalizations based on the available peer-reviewed literature. This paper uses a meta-analysis of U.S. cities’ current experience with urban adaptation planning drawing from 54 sources that include peer-reviewed literature, government reports, white papers, and reports published by non-governmental organizations. The analysis specifically evaluates the institutional support structures being developed for urban climate change adaptation. The results demonstrate that adaptation planning is driven by a desire to reduce vulnerability and often catalyzes new collaborations and coordination mechanisms in urban governance. As a result, building capacity for urban climate change adaptation planning requires a focus not only on city governments themselves but also on the complex horizontal and vertical networks that have arisen around such efforts. Existing adaptation planning often lacks attention to equity issues, social vulnerability, and the influence of non-climatic factors on vulnerability. Engaging city govern

  19. Geospatial scenario based modelling of urban and agricultural intrusions in Ramsar wetland Deepor Beel in Northeast India using a multi-layer perceptron neural network

    Science.gov (United States)

    Mozumder, Chitrini; Tripathi, Nitin K.

    2014-10-01

    In recent decades, the world has experienced unprecedented urban growth which endangers the green environment in and around urban areas. In this work, an artificial neural network (ANN) based model is developed to predict future impacts of urban and agricultural expansion on the uplands of Deepor Beel, a Ramsar wetland in the city area of Guwahati, Assam, India, by 2025 and 2035 respectively. Simulations were carried out for three different transition rates as determined from the changes during 2001-2011, namely simple extrapolation, Markov Chain (MC), and system dynamic (SD) modelling, using projected population growth, which were further investigated based on three different zoning policies. The first zoning policy employed no restriction while the second conversion restriction zoning policy restricted urban-agricultural expansion in the Guwahati Municipal Development Authority (GMDA) proposed green belt, extending to a third zoning policy providing wetland restoration in the proposed green belt. The prediction maps were found to be greatly influenced by the transition rates and the allowed transitions from one class to another within each sub-model. The model outputs were compared with GMDA land demand as proposed for 2025 whereby the land demand as produced by MC was found to best match the projected demand. Regarding the conservation of Deepor Beel, the Landscape Development Intensity (LDI) Index revealed that wetland restoration zoning policies may reduce the impact of urban growth on a local scale, but none of the zoning policies was found to minimize the impact on a broader base. The results from this study may assist the planning and reviewing of land use allocation within Guwahati city to secure ecological sustainability of the wetlands.

  20. A network model for the propagation of Hepatitis C with HIV co-infection

    Science.gov (United States)

    Nucit, Arnaud; Randon-Furling, Julien

    2017-05-01

    We define and examine a model of epidemic propagation for a virus such as Hepatitis C (with HIV co-infection) on a network of networks, namely the network of French urban areas. One network level is that of the individual interactions inside each urban area. The second level is that of the areas themselves, linked by individuals travelling between these areas and potentially helping the epidemic spread from one city to another. We choose to encode the second level of the network as extra, special nodes in the first level. We observe that such an encoding leads to sensible results in terms of the extent and speed of propagation of an epidemic, depending on its source point.