WorldWideScience

Sample records for efficient distributed location

  1. Efficient Location of Distribution Centres and Warehouses in the Territory of a Region

    Directory of Open Access Journals (Sweden)

    Pavel Vladimirovich Popov

    2017-09-01

    Full Text Available The article is devoted to the creation of efficient regional logistic infrastructure that has currently a special relevance. The additional task of this problem is a warehouse network formation. The efficient location of warehouses is one of the priority objectives for cross-border regions as it allows them to benefit from membership in a global supply chain, promotes the creation of additional jobs and, finally, leads to the growth of Gross Regional Product (GRP. The authors offer an approach to determine the location of distribution centres and warehouses in the territory of the regions of the Russian Federation. This approach allows solving the problem of the efficient location of warehouse network in a region taking into account its key indicators of socioeconomic development. The implementation of the approach identified the indicators that have a significant impact on a choice of the location of warehouses of a region. Methodological framework of the conducted research includes the methods of ABC and cluster analyses. That provides the identification of the cities and municipal districts of a region, in the territory of which it is expedient to locate warehouses. The developed approach was tested on the example of the Volgograd region. The solution of the problem of warehouse network in this region belongs to the priority one, considering its geographical position and industrial capacity. The analysis of indicator values for the period of 2010–2014 by means of the methods of classical and modern ABC analysis as well as the two-stage cluster analysis allowed the territorial binding of the warehouse network in the Volgograd region. Further, the research showed that when splitting the cities and municipal districts of the region into clusters, the greatest influence is made by such indicators as investments into fixed capital, goods turnover of the motor transport and transportation of goods by the motor transport.

  2. Energy Efficient Content Distribution

    OpenAIRE

    Araujo J.; Giroire F.; Liu Y; Modrzejewski R.; Moulierac J.

    2016-01-01

    To optimize energy efficiency in network, operators try to switch off as many network devices as possible. Recently, there is a trend to introduce content caches as an inherent capacity of network equipment, with the objective of improving the efficiency of content distribution and reducing network congestion. In this work, we study the impact of using in-network caches and CDN cooperation on an energy-efficient routing. We formulate this problem as Energy Efficient Content Distribution. The ...

  3. New Location Improves Efficiency | Poster

    Science.gov (United States)

    By Nancy Parrish, Staff Writer The physical proximity of the SAIC-Frederick Intellectual Property (IP) Office to the NCI Technology Transfer Center (NCI-TTC) is one of the many benefits of being at the Advanced Technology Research Facility (ATRF), according to Courtney Silverthorn, Ph.D. Being in one location “has increased the effectiveness of both informal communication and formal meetings. We have already brainstormed solutions for several issues in the hallway during an informal chat,” said Silverthorn, an SAIC-Frederick IP specialist.

  4. Efficient Location of Information in Special Education.

    Science.gov (United States)

    Kissinger, Patricia; Ary, Donald

    Many individuals are concerned that the "knowledge explosion" in special education is making it difficult to keep up with research in the field. However, at the same time that knowledge has been expanding, efficient ways of locating knowledge have developed and additional sources of integrative reviews of research have appeared. The paper…

  5. Reconstructing Spatial Distributions from Anonymized Locations

    Energy Technology Data Exchange (ETDEWEB)

    Horey, James L [ORNL; Forrest, Stephanie [University of New Mexico, Albuquerque; Groat, Michael [University of New Mexico, Albuquerque

    2012-01-01

    Devices such as mobile phones, tablets, and sensors are often equipped with GPS that accurately report a person's location. Combined with wireless communication, these devices enable a wide range of new social tools and applications. These same qualities, however, leave location-aware applications vulnerable to privacy violations. This paper introduces the Negative Quad Tree, a privacy protection method for location aware applications. The method is broadly applicable to applications that use spatial density information, such as social applications that measure the popularity of social venues. The method employs a simple anonymization algorithm running on mobile devices, and a more complex reconstruction algorithm on a central server. This strategy is well suited to low-powered mobile devices. The paper analyzes the accuracy of the reconstruction method in a variety of simulated and real-world settings and demonstrates that the method is accurate enough to be used in many real-world scenarios.

  6. Valuating the Investment Efficiency of Distribution Companies

    Directory of Open Access Journals (Sweden)

    M. Karajica

    2007-01-01

    Full Text Available The task of this study is to valuate the investment efficiency of distribution companies. Although a series of publications and studies has been dedicated to this topic, it is difficult to find a general consensus in defining the investment efficiency of a company. Nevertheless if we simplify an imaginary  company as a production unit in which a series of actions transforms inputs to outputs, efficiency can be understood as like an effort to achieve maximum value of the outputs together with minimum usage of inputs, where the inputs constitute investments by a company. The investment efficiency of a company can be measured by expressing the absolute values of selected inputs and outputs, a relative expression of inputs and outputs, and perhaps an expression of the difference between them. However, an examination of the efficiency of a certain company is impossible without a valuation of other companies. In view of the amount of benchmarking, it should be emphasized, that this study is dedicated to a certain category of benchmarking, which we may term investment benchmarking. This benchmarking can be defined as a comparison of companies in terms investment efficiency. The purpose of this comparison is not only to investigate levels of investment efficiency and to relate them to other companies from the same branch, but also to locate the greatest efficiency and indicate potential improvement. 

  7. Distribution Locational Marginal Pricing for Optimal Electric Vehicle Charging Management

    DEFF Research Database (Denmark)

    Li, Ruoyang; Wu, Qiuwei; Oren, Shmuel S.

    2013-01-01

    This paper presents an integrated distribution locational marginal pricing (DLMP) method designed to alleviate congestion induced by electric vehicle (EV) loads in future power systems. In the proposed approach, the distribution system operator (DSO) determines distribution locational marginal...... prices (DLMPs) by solving the social welfare optimization of the Electric distribution system which considers EV aggregators as Price takers in the local DSO market and demand price elasticity. Nonlinear optimization has been used to solve the social welfare optimization problem in order to obtain...

  8. Distribution Locational Marginal Pricing for Optimal Electric Vehicle Charging Management

    OpenAIRE

    Li, Ruoyang; Wu, Qiuwei; Shmuel S Oren

    2013-01-01

    This paper presents an integrated distribution locational marginal pricing (DLMP) method designed to alleviate congestion induced by electric vehicle (EV) loads in future power systems. In the proposed approach, the distribution system operator (DSO) determines distribution locational marginal prices (DLMPs) by solving the social welfare optimization of the Electric distribution system which considers EV aggregators as Price takers in the local DSO market and demand price elasticity. Nonlinea...

  9. An Efficient Location Verification Scheme for Static Wireless Sensor Networks.

    Science.gov (United States)

    Kim, In-Hwan; Kim, Bo-Sung; Song, JooSeok

    2017-01-24

    In wireless sensor networks (WSNs), the accuracy of location information is vital to support many interesting applications. Unfortunately, sensors have difficulty in estimating their location when malicious sensors attack the location estimation process. Even though secure localization schemes have been proposed to protect location estimation process from attacks, they are not enough to eliminate the wrong location estimations in some situations. The location verification can be the solution to the situations or be the second-line defense. The problem of most of the location verifications is the explicit involvement of many sensors in the verification process and requirements, such as special hardware, a dedicated verifier and the trusted third party, which causes more communication and computation overhead. In this paper, we propose an efficient location verification scheme for static WSN called mutually-shared region-based location verification (MSRLV), which reduces those overheads by utilizing the implicit involvement of sensors and eliminating several requirements. In order to achieve this, we use the mutually-shared region between location claimant and verifier for the location verification. The analysis shows that MSRLV reduces communication overhead by 77% and computation overhead by 92% on average, when compared with the other location verification schemes, in a single sensor verification. In addition, simulation results for the verification of the whole network show that MSRLV can detect the malicious sensors by over 90% when sensors in the network have five or more neighbors.

  10. Protection of Location Privacy Based on Distributed Collaborative Recommendations.

    Science.gov (United States)

    Wang, Peng; Yang, Jing; Zhang, Jian-Pei

    2016-01-01

    In the existing centralized location services system structure, the server is easily attracted and be the communication bottleneck. It caused the disclosure of users' location. For this, we presented a new distributed collaborative recommendation strategy that is based on the distributed system. In this strategy, each node establishes profiles of their own location information. When requests for location services appear, the user can obtain the corresponding location services according to the recommendation of the neighboring users' location information profiles. If no suitable recommended location service results are obtained, then the user can send a service request to the server according to the construction of a k-anonymous data set with a centroid position of the neighbors. In this strategy, we designed a new model of distributed collaborative recommendation location service based on the users' location information profiles and used generalization and encryption to ensure the safety of the user's location information privacy. Finally, we used the real location data set to make theoretical and experimental analysis. And the results show that the strategy proposed in this paper is capable of reducing the frequency of access to the location server, providing better location services and protecting better the user's location privacy.

  11. Energy Efficiency in Grocery Distribution in Denmark

    DEFF Research Database (Denmark)

    Jørgensen, Kaj

    1997-01-01

    Evaluation of the development of the energy efficiency of grocery distribution from 1960 to the present in Denmark, covering both the distribution to the shops and the shopping transport (distribution from shops to individual homes)......Evaluation of the development of the energy efficiency of grocery distribution from 1960 to the present in Denmark, covering both the distribution to the shops and the shopping transport (distribution from shops to individual homes)...

  12. On the Design of Energy-Efficient Location Tracking Mechanism in Location-Aware Computing

    Directory of Open Access Journals (Sweden)

    MoonBae Song

    2005-01-01

    Full Text Available The battery, in contrast to other hardware, is not governed by Moore's Law. In location-aware computing, power is a very limited resource. As a consequence, recently, a number of promising techniques in various layers have been proposed to reduce the energy consumption. The paper considers the problem of minimizing the energy used to track the location of mobile user over a wireless link in mobile computing. Energy-efficient location update protocol can be done by reducing the number of location update messages as possible and switching off as long as possible. This can be achieved by the concept of mobility-awareness we propose. For this purpose, this paper proposes a novel mobility model, called state-based mobility model (SMM to provide more generalized framework for both describing the mobility and updating location information of complexly moving objects. We also introduce the state-based location update protocol (SLUP based on this mobility model. An extensive experiment on various synthetic datasets shows that the proposed method improves the energy efficiency by 2 ∼ 3 times with the additional 10% of imprecision cost.

  13. Location Analysis of Freight Distribution Terminal of Jakarta City, Indonesia

    Directory of Open Access Journals (Sweden)

    Nahry Nahry

    2016-03-01

    Full Text Available Currently Jakarta has two freight terminals, namely Pulo Gebang and Tanah Merdeka. But, both terminals are just functioned for parking and have not been utilized properly yet, e.g. for consolidation. Goods consolidation, which is usually performed in distribution terminal, may reduce number of freight flow within the city. This paper is aimed to determine the best location of distribution terminal in Jakarta among those two terminals and two additional alternative sites, namely Lodan and Rawa Buaya. It is initialized by the identification of important factors that affect the location selection. It is carried out by Likert analysis through the questionnaires distributed to logistics firms. The best location is determined by applying Overlay Analysis using ArcGIS 9.2. Four grid maps are produced to represent the accessibility, cost, time, and environment factors as the important factors of location. The result shows that the ranking from the best is; Lodan, Tanah Merdeka, Pulo Gebang, and Rawa Buaya.

  14. Logistics Distribution Center Location Optimizatio Model An Example Study

    Directory of Open Access Journals (Sweden)

    Li Lingling

    2017-01-01

    Full Text Available This paper analyzes and investigates the situation of the today’s site of distribution centers .Then taking SF Express for an example ,In the light of minimize the total expense ,the location models for single distribution centers is established with the corresponding resolutions given .After that ,The location of the single distribution center of SF Express ,the starting point of which is Zhengzhou Railway Station ,can be determined with the help of distance-testing function of 360 map to conclude its coordinate and then determine its exact service spot .This paper will test the feasibility of above models by the chosen cases with the application of LINGO software.

  15. Using Weighted Graphs for Computationally Efficient WLAN Location Determination

    DEFF Research Database (Denmark)

    Thomsen, Bent; Hansen, Rene

    2007-01-01

    Indoor location-based services hold promise for a multitude of valuable services, but require micro-detailed geo-referencing not achievable with "outdoor" technologies such as GPS and cellular networks. A widely used technique for accurate indoor positioning is location fingerprinting which makes...... use of existing WLAN infrastructures. The technique consists of building a radio map of signal strength measurements which is searched to determine a position estimate. While the fingerprinting technique has produced good positioning accuracy results, the technique incurs a substantial computational...... burden for large buildings and is thus problematic for tracking users in real time on processor-constrained mobile devices. In this paper we present a technique for improving the computational efficiency of the fingerprinting technique such that location determination becomes tractable on a mobile device...

  16. Optimal location of distributed generation for loss minimization in ...

    African Journals Online (AJOL)

    Accurate loss minimization is the critical component for efficient electrical power flow. The introduction of distributed generation (DG) in networks is bound to have significant effect in network losses. Such dispersed generators can reduce distribution system loss by appropriate allocation. With the integration of DG into an ...

  17. Energy efficient distributed computing systems

    CERN Document Server

    Lee, Young-Choon

    2012-01-01

    The energy consumption issue in distributed computing systems raises various monetary, environmental and system performance concerns. Electricity consumption in the US doubled from 2000 to 2005.  From a financial and environmental standpoint, reducing the consumption of electricity is important, yet these reforms must not lead to performance degradation of the computing systems.  These contradicting constraints create a suite of complex problems that need to be resolved in order to lead to 'greener' distributed computing systems.  This book brings together a group of outsta

  18. AN INTEGRATED PRODUCTION, INVENTORY, WAREHOUSE LOCATION AND DISTRIBUTION MODE

    Directory of Open Access Journals (Sweden)

    Lokendra Kumar Devangan

    2016-12-01

    Full Text Available This paper proposes an integrated production and distribution planning optimization model for multiple manufacturing locations, producing multiple products with deterministic demand at multiple locations. There are multiple modes of transport from plants to demand locations and warehouses. This study presents a model which allows decision makers to optimize plant production, transport and warehouse location simultaneously to fulfill the demands at customer locations within a multi-plant, multi-product, and multi-route supply chain system when the locations of the plants are already fixed. The proposed model is solved for sample problems and tested using real data from a cement manufacturing company in India. An analysis of the results suggests that this model can be used for various strategic and tactical production and planning decisions.

  19. Locational distribution of gene functional classes in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    King Ross D

    2007-03-01

    Full Text Available Abstract Background We are interested in understanding the locational distribution of genes and their functions in genomes, as this distribution has both functional and evolutionary significance. Gene locational distribution is known to be affected by various evolutionary processes, with tandem duplication thought to be the main process producing clustering of homologous sequences. Recent research has found clustering of protein structural families in the human genome, even when genes identified as tandem duplicates have been removed from the data. However, this previous research was hindered as they were unable to analyse small sample sizes. This is a challenge for bioinformatics as more specific functional classes have fewer examples and conventional statistical analyses of these small data sets often produces unsatisfactory results. Results We have developed a novel bioinformatics method based on Monte Carlo methods and Greenwood's spacing statistic for the computational analysis of the distribution of individual functional classes of genes (from GO. We used this to make the first comprehensive statistical analysis of the relationship between gene functional class and location on a genome. Analysis of the distribution of all genes except tandem duplicates on the five chromosomes of A. thaliana reveals that the distribution on chromosomes I, II, IV and V is clustered at P = 0.001. Many functional classes are clustered, with the degree of clustering within an individual class generally consistent across all five chromosomes. A novel and surprising result was that the locational distribution of some functional classes were significantly more evenly spaced than would be expected by chance. Conclusion Analysis of the A. thaliana genome reveals evidence of unexplained order in the locational distribution of genes. The same general analysis method can be applied to any genome, and indeed any sequential data involving classes.

  20. A probabilistic methodology for distributed generation location in isolated electrical service area

    Energy Technology Data Exchange (ETDEWEB)

    Khodr, H.M.; Silva, Marco R.; Vale, Zita; Ramos, Carlos [GECAD - Knowledge Engineering and Decision-Support Research Center of the Polytechnic Institute of Porto (ISEP/IPP), Rua Dr. Antonio Bernardino de Almeida 431, 4200-072 Porto (Portugal)

    2010-04-15

    Distributed generation unlike centralized electrical generation aims to generate electrical energy on small scale as near as possible to load centers, interchanging electric power with the network. This work presents a probabilistic methodology conceived to assist the electric system planning engineers in the selection of the distributed generation location, taking into account the hourly load changes or the daily load cycle. The hourly load centers, for each of the different hourly load scenarios, are calculated deterministically. These location points, properly weighted according to their load magnitude, are used to calculate the best fit probability distribution. This distribution is used to determine the maximum likelihood perimeter of the area where each source distributed generation point should preferably be located by the planning engineers. This takes into account, for example, the availability and the cost of the land lots, which are factors of special relevance in urban areas, as well as several obstacles important for the final selection of the candidates of the distributed generation points. The proposed methodology has been applied to a real case, assuming three different bivariate probability distributions: the Gaussian distribution, a bivariate version of Freund's exponential distribution and the Weibull probability distribution. The methodology algorithm has been programmed in MATLAB. Results are presented and discussed for the application of the methodology to a realistic case and demonstrate the ability of the proposed methodology for efficiently handling the determination of the best location of the distributed generation and their corresponding distribution networks. (author)

  1. optimal location of distributed generation on the nigerian power ...

    African Journals Online (AJOL)

    user

    The optimal sizing and location of distributed generators (DG) remain crucial factors in their application for active power loss minimization as well as voltage profile improvement. This paper describes an analytical method for the optimal sizing and placement of DG in the Nigerian power network for active power loss ...

  2. Voltage Sags Matching to Locate Faults for Underground Distribution Networks

    Directory of Open Access Journals (Sweden)

    BAKAR, A. H. A.

    2011-05-01

    Full Text Available A voltage sags matching to locate a fault for underground distribution network is presented in this paper. Firstly the method identifies the faulted section by matching a voltage sags measured at the primary substation during a fault with pre-developed voltage sag database. From the identified faulted section, the distance of a fault from sending-end is calculated. The problem of multiple sections is addressed by ranking approach. Test results on an underground distribution network shows most faults can be located by the first attempt within high accuracy distance. Only few faulted sections found by the second attempt. Since the method is using only voltage sag data, monitored at the primary substation, the method is considers economical to be implemented for a rural distribution network.

  3. Learning a Probability Distribution Efficiently and Reliably

    Science.gov (United States)

    Laird, Philip; Gamble, Evan

    1988-01-01

    A new algorithm, called the CDF-Inversion Algorithm, is described. Using it, one can efficiently learn a probability distribution over a finite set to a specified accuracy and confidence. The algorithm can be extended to learn joint distributions over a vector space. Some implementation results are described.

  4. A story about distributions of dimensions and locations of boulders

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager

    2006-01-01

    distributions are well modeled by a Markov chain type of model. Different details of the data and their statistical analysis support several modeling conjectures concerning the glacial history of boulder deposition. In a companion paper it is described how the results of this beach boulder investigation...... for making a bored tunnel through the till deposit. Geographical universality was discovered through the statistical analysis of observations of boulder coordinates and dimension measures from wide spread cliff beach locations. One conclusion is that the joint size distribution up to some degree of modeling...

  5. A two-level facility location problem for the location of distribution centers

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.

    1994-12-31

    This paper makes an attempt to build a location choice model for distribution centers. This model follows the form of the (one-level) facility location problem (FLP), takes the less-than-truckload (routing) factor into account, and becomes a two-level facility location problem. The upper-level subproblem of the two-level FLP is the uncapacitated FLP and the lower-level subproblem is the capacitated FLP with single source. Heuristics algorithms are developed based on the characteristics of the two-level FLP. That`s, the upper-level subproblem is solved by enumeration or greedy, the lower-level subproblem is solved by a Lagrangian Relaxation algorithm, and then, two-level algorithms which combine different algorithms to solve subproblems, respectively, are developed. The real-world case, a firm which manufactures goods for daily use choosing distribution centers from several candidate sites, is tested by making use of the two-level FLP. The outputs with the one-level FLP and two-level FLP are different, i.e., the less-than-truckload factor simplified to the truckload factor may result in a bias location choice.

  6. Estimation of the location parameter of distributions with known coefficient of variation by record values

    Directory of Open Access Journals (Sweden)

    N. K. Sajeevkumar

    2014-09-01

    Full Text Available In this article, we derived the Best Linear Unbiased Estimator (BLUE of the location parameter of certain distributions with known coefficient of variation by record values. Efficiency comparisons are also made on the proposed estimator with some of the usual estimators. Finally we give a real life data to explain the utility of results developed in this article.

  7. Iron distribution on a chronosequence located at Imo River ...

    African Journals Online (AJOL)

    Iron distribution on a chronosequence located at Imo River floodplain, South Eastern Nigeria. ... We also postulated that soil pH could be used to predict availability of Fe forms based result of correlation (r = 0.78 -0.82, p=0.05, n =15) and coefficient of determination (r2 = 0.61 - 0.70, p = 0.05 n =15). International Journal of ...

  8. Design and implementation of urban logistics distribution center location optimization system

    Directory of Open Access Journals (Sweden)

    Peng GUO

    2017-02-01

    Full Text Available In order to improve the efficiency of urban logistics distribution center location selection, and to overcome the shortcomings of the traditional method based on human aided calculation, the online map is used to obtain the path distance information. Considering the practical construction and operation situation of the logistics distribution center, the cost related impact factors are determined and the location optimization frame is described. Then the mathematical formulation is proposed for minimizing the total cost, and the genetic algorithm based on integer code is designed to solve the problem under consideration. The corresponding system is implemented by C# language. The system is tested based on the practical data, and the computational results demonstrate that the proposed system can automatically obtain the distance information between various nodes and perform the location optimization. Finally the optimal feasible location scheme is delivered by the proposed system.

  9. Solute location in a nanoconfined liquid depends on charge distribution

    Science.gov (United States)

    Harvey, Jacob A.; Thompson, Ward H.

    2015-07-01

    Nanostructured materials that can confine liquids have attracted increasing attention for their diverse properties and potential applications. Yet, significant gaps remain in our fundamental understanding of such nanoconfined liquids. Using replica exchange molecular dynamics simulations of a nanoscale, hydroxyl-terminated silica pore system, we determine how the locations explored by a coumarin 153 (C153) solute in ethanol depend on its charge distribution, which can be changed through a charge transfer electronic excitation. The solute position change is driven by the internal energy, which favors C153 at the pore surface compared to the pore interior, but less so for the more polar, excited-state molecule. This is attributed to more favorable non-specific solvation of the large dipole moment excited-state C153 by ethanol at the expense of hydrogen-bonding with the pore. It is shown that a change in molecule location resulting from shifts in the charge distribution is a general result, though how the solute position changes will depend upon the specific system. This has important implications for interpreting measurements and designing applications of mesoporous materials.

  10. Optimizing lengths of confidence intervals: fourth-order efficiency in location models

    NARCIS (Netherlands)

    Klaassen, C.; Venetiaan, S.

    2010-01-01

    Under regularity conditions the maximum likelihood estimator of the location parameter in a location model is asymptotically efficient among translation equivariant estimators. Additional regularity conditions warrant third- and even fourth-order efficiency, in the sense that no translation

  11. An Efficient Lattice-based Distributed IBE

    Directory of Open Access Journals (Sweden)

    Yin Lu

    2016-01-01

    Full Text Available This paper improves the lattice-based secret sharing method presented by Bansarkhani and Meziani and combines the method with the IBE based on the standard LWE problem constructing an efficient lattice-based distributed decryption IBE. Our construction avoids the weakness in the traditional method like Lagrange interpolation, Blakley’s space geometry method or Chinese remainder theorem method. Through theoretical analysis, compared with the bilinear pairing based distributed IBE, our scheme refrains from the complex pairing operation and has less calculation cost. A proof of security holds in the standard model.

  12. Efficient Location Uncertainty Treatment for Probabilistic Modelling of Portfolio Loss from Earthquake Events

    Science.gov (United States)

    Scheingraber, Christoph; Käser, Martin; Allmann, Alexander

    2017-04-01

    Probabilistic seismic risk analysis (PSRA) is a well-established method for modelling loss from earthquake events. In the insurance industry, it is widely employed for probabilistic modelling of loss to a distributed portfolio. In this context, precise exposure locations are often unknown, which results in considerable loss uncertainty. The treatment of exposure uncertainty has already been identified as an area where PSRA would benefit from increased research attention. However, so far, epistemic location uncertainty has not been in the focus of a large amount of research. We propose a new framework for efficient treatment of location uncertainty. To demonstrate the usefulness of this novel method, a large number of synthetic portfolios resembling real-world portfolios is systematically analyzed. We investigate the effect of portfolio characteristics such as value distribution, portfolio size, or proportion of risk items with unknown coordinates on loss variability. Several sampling criteria to increase the computational efficiency of the framework are proposed and put into the wider context of well-established Monte-Carlo variance reduction techniques. The performance of each of the proposed criteria is analyzed.

  13. Efficient Indoor Proximity and Separation Detection for Location Fingerprinting

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Treu, Georg; Ruppel, Peter

    2008-01-01

    Detecting proximity and separation among mobile targets is a basic mechanism for many location-based services (LBSs) and requires continuous positioning and tracking. However, realizing both mechanisms for indoor usage is still a major challenge. Positioning methods like GPS cannot be applied there......, and for distance calculations the particular building topology has to be taken into account. To address these challenges, this paper presents a novel approach for indoor proximity and separation detection, which uses location fingerprinting for indoor positioning of targets and walking distances for modeling...

  14. Optimization of pressure gauge locations for water distribution systems using entropy theory.

    Science.gov (United States)

    Yoo, Do Guen; Chang, Dong Eil; Jun, Hwandon; Kim, Joong Hoon

    2012-12-01

    It is essential to select the optimal pressure gauge location for effective management and maintenance of water distribution systems. This study proposes an objective and quantified standard for selecting the optimal pressure gauge location by defining the pressure change at other nodes as a result of demand change at a specific node using entropy theory. Two cases are considered in terms of demand change: that in which demand at all nodes shows peak load by using a peak factor and that comprising the demand change of the normal distribution whose average is the base demand. The actual pressure change pattern is determined by using the emitter function of EPANET to reflect the pressure that changes practically at each node. The optimal pressure gauge location is determined by prioritizing the node that processes the largest amount of information it gives to (giving entropy) and receives from (receiving entropy) the whole system according to the entropy standard. The suggested model is applied to one virtual and one real pipe network, and the optimal pressure gauge location combination is calculated by implementing the sensitivity analysis based on the study results. These analysis results support the following two conclusions. Firstly, the installation priority of the pressure gauge in water distribution networks can be determined with a more objective standard through the entropy theory. Secondly, the model can be used as an efficient decision-making guide for gauge installation in water distribution systems.

  15. Computation of Locational and Hourly Maximum Output of a Distributed Generator Connected to a Distribution Feeder

    Science.gov (United States)

    Hayashi, Yasuhiro; Matsuki, Junya; Hanai, Yuji; Hosokawa, Shinpei; Kobayashi, Naoki

    Recently, the total number of distributed generation such as photovoltaic generation system and wind turbine generation system connected to distribution network is drastically increased. Distributed generation utilizing renewable energy can reduce the distribution loss and emission of CO2. However the distribution network with the distributed generators must be operated keeping reliability of power supply and power quality. In this paper, the authors propose a computation method to determine the maximum output of a distributed generator under the operational constrains ((1) voltage limit, (2) line current capacity, and (3) no reverse flow to bank) at arbitrary connection point and hourly period. In the proposed method, three-phase iterative load flow calculation is applied to evaluate the above operational constraints. Three-phase iterative load flow calculation has two simple procedures: (Procedure1) addition of load currents from terminal node of feeder to root one, and (Procedure2) subtraction of voltage drop from root node of feeder to terminal one. In order to check the validity of the proposed method, numerical simulations are accomplished for a distribution system model. Furthermore, characteristics of locational and hourly maximum output of distributed generator connected to distribution feeder are analyzed by several numerical examples.

  16. INEMO: Distributed RF-Based Indoor Location Determination with Confidence Indicator

    Science.gov (United States)

    Li, Hongbin; Shen, Xingfa; Zhao, Jun; Wang, Zhi; Sun, Youxian

    2007-12-01

    Using radio signal strength (RSS) in sensor networks localization is an attractive method since it is a cost-efficient method to provide range indication. In this paper, we present a two-tier distributed approach for RF-based indoor location determination. Our approach, namely, INEMO, provides positioning accuracy of room granularity and office cube granularity. A target can first give a room granularity request and the background anchor nodes cooperate to accomplish the positioning process. Anchors in the same room can give cube granularity if the target requires further accuracy. Fixed anchor nodes keep monitoring status of nearby anchors and local reference matching is used to support room separation. Furthermore, we utilize the RSS difference to infer the positioning confidence. The simulation results demonstrate the efficiency of the proposed RF-based indoor location determination.

  17. INEMO: Distributed RF-Based Indoor Location Determination with Confidence Indicator

    Directory of Open Access Journals (Sweden)

    Youxian Sun

    2007-12-01

    Full Text Available Using radio signal strength (RSS in sensor networks localization is an attractive method since it is a cost-efficient method to provide range indication. In this paper, we present a two-tier distributed approach for RF-based indoor location determination. Our approach, namely, INEMO, provides positioning accuracy of room granularity and office cube granularity. A target can first give a room granularity request and the background anchor nodes cooperate to accomplish the positioning process. Anchors in the same room can give cube granularity if the target requires further accuracy. Fixed anchor nodes keep monitoring status of nearby anchors and local reference matching is used to support room separation. Furthermore, we utilize the RSS difference to infer the positioning confidence. The simulation results demonstrate the efficiency of the proposed RF-based indoor location determination.

  18. Differential Location and Distribution of Hepatic Immune Cells

    Directory of Open Access Journals (Sweden)

    Maria Alice Freitas-Lopes

    2017-12-01

    Full Text Available The liver is one of the main organs in the body, performing several metabolic and immunological functions that are indispensable to the organism. The liver is strategically positioned in the abdominal cavity between the intestine and the systemic circulation. Due to its location, the liver is continually exposed to nutritional insults, microbiota products from the intestinal tract, and to toxic substances. Hepatocytes are the major functional constituents of the hepatic lobes, and perform most of the liver’s secretory and synthesizing functions, although another important cell population sustains the vitality of the organ: the hepatic immune cells. Liver immune cells play a fundamental role in host immune responses and exquisite mechanisms are necessary to govern the density and the location of the different hepatic leukocytes. Here we discuss the location of these pivotal cells within the different liver compartments, and how their frequency and tissular location can dictate the fate of liver immune responses.

  19. Location Distribution Optimization of Photographing Sites for Indoor Panorama Modeling

    Science.gov (United States)

    Zhang, S.; Wu, J.; Zhang, Y.; Zhang, X.; Xin, Z.; Liu, J.

    2017-09-01

    Generally, panoramas image modeling is costly and time-consuming because of photographing continuously to capture enough photos along the routes, especially in complicated indoor environment. Thus, difficulty follows for a wider applications of panoramic image modeling for business. It is indispensable to make a feasible arrangement of panorama sites locations because the locations influence the clarity, coverage and the amount of panoramic images under the condition of certain device. This paper is aim to propose a standard procedure to generate the specific location and total amount of panorama sites in indoor panoramas modeling. Firstly, establish the functional relationship between one panorama site and its objectives. Then, apply the relationship to panorama sites network. We propose the Distance Clarity function (FC and Fe) manifesting the mathematical relationship between panoramas and objectives distance or obstacle distance. The Distance Buffer function (FB) is modified from traditional buffer method to generate the coverage of panorama site. Secondly, transverse every point in possible area to locate possible panorama site, calculate the clarity and coverage synthetically. Finally select as little points as possible to satiate clarity requirement preferentially and then the coverage requirement. In the experiments, detailed parameters of camera lens are given. Still, more experiments parameters need trying out given that relationship between clarity and distance is device dependent. In short, through the function FC, Fe and FB, locations of panorama sites can be generated automatically and accurately.

  20. A Distribution-class Locational Marginal Price (DLMP) Index for Enhanced Distribution Systems

    Science.gov (United States)

    Akinbode, Oluwaseyi Wemimo

    The smart grid initiative is the impetus behind changes that are expected to culminate into an enhanced distribution system with the communication and control infrastructure to support advanced distribution system applications and resources such as distributed generation, energy storage systems, and price responsive loads. This research proposes a distribution-class analog of the transmission LMP (DLMP) as an enabler of the advanced applications of the enhanced distribution system. The DLMP is envisioned as a control signal that can incentivize distribution system resources to behave optimally in a manner that benefits economic efficiency and system reliability and that can optimally couple the transmission and the distribution systems. The DLMP is calculated from a two-stage optimization problem; a transmission system OPF and a distribution system OPF. An iterative framework that ensures accurate representation of the distribution system's price sensitive resources for the transmission system problem and vice versa is developed and its convergence problem is discussed. As part of the DLMP calculation framework, a DCOPF formulation that endogenously captures the effect of real power losses is discussed. The formulation uses piecewise linear functions to approximate losses. This thesis explores, with theoretical proofs, the breakdown of the loss approximation technique when non-positive DLMPs/LMPs occur and discusses a mixed integer linear programming formulation that corrects the breakdown. The DLMP is numerically illustrated in traditional and enhanced distribution systems and its superiority to contemporary pricing mechanisms is demonstrated using price responsive loads. Results show that the impact of the inaccuracy of contemporary pricing schemes becomes significant as flexible resources increase. At high elasticity, aggregate load consumption deviated from the optimal consumption by up to about 45 percent when using a flat or time-of-use rate. Individual load

  1. More efficient distribution of district cooling; Effektivare Distribution av Fjaerrkyla

    Energy Technology Data Exchange (ETDEWEB)

    Kaellman, Olle; Hindersson, Per [Jarl Magnusson AB, Stockholm (Sweden); Nord, Boerje [BN Consulting (Sweden)

    2004-07-01

    The output in a network for district cooling is directly proportional to the temperature difference. A lower return temperature gives a higher water through-flow, which in turn leads to a lower system efficiency and thereby higher costs to both supplier and customer. A network in which the customer receives the agreed return temperature, or higher, gives greater reliability of supply and lower costs. The report presents various technical options and measures that can be installed in a property for an effective distribution of district cooling. The focus has been oriented towards options and measures for increasing the return temperature in the network. Simulations and calculations have been conducted for three different cases with cooling systems that supply a modular-structured 2,000 m{sup 2} office with cooling. Case A: Basic case with cooled supply air - minimum flow as per requirements; Case B: VAV system with cooled supply air - increased air flow; Case C: CAV system with cooled supply air and active cooling baffles. On the basis of the above cases, the report discusses which technical measures can be carried out in order to increase the efficiency of district cooling distribution. The most important conclusions drawn from this project can be summarised as follows: Increasing the number of water channels in a coil for cooling outdoor air is a very effective way of increasing the return temperature in a property brine cycle. It is possible to place higher demands than 16 deg C and 18 deg C on the return temperature from coils for the cooling of outdoor air A higher outdoor design temperature when sizing cooling coils is not to be recommended as a practicable way of raising the return temperature in a district cooling system Sizing on the basis of a higher outdoor design temperature gives a higher subscribed power that is used for a few hours per year. The alternative involving a lower outdoor design temperature releases power for new customers There must not be

  2. optimal location of distributed generation on the nigerian power ...

    African Journals Online (AJOL)

    user

    28-bus Nigerian power network are explained in. Section 4 with the conclusions and areas of future research in ... minimization in a network system based on bus admittance, generation information and load ..... determine the optimal location and sizing of DGs. The installation of DG unit at non optimal places can result.

  3. An Efficient Algorithm for Fault Location on Mixed Line-Cable Transmission Corridors

    NARCIS (Netherlands)

    Popov, M.; Rietveld, G.; Radojevic, Z.; Terzija, V.

    2013-01-01

    This paper presents a fault location algorithm that can be used to accurately locate the fault at any place along mixed line-cable transmission corridors. The algorithm is an impedance based line/cable parameter dependent algorithm. The fault location algorithm is derived using distributed line

  4. Autonomy-oriented mechanisms for efficient energy distribution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiming; Shi, Benyun

    2010-09-15

    Due to the uneven geographical availability of energy resources, it is essential for the energy suppliers and consumers in different countries/regions to most efficiently, economically, as well as reliably distribute energy resources. In this paper, starting from a specific energy distribution problem, we present a decentralized behavior-based paradigm that draws on the methodology of autonomy-oriented computing. The goal is twofold: (i) to characterize the underlying mechanism of the energy distribution systems, (ii) to provide scalable solutions for efficient energy distribution. We conjecture that efficient energy trading markets can emerge from appropriate behavior-based mechanisms, which can autonomously improve energy distribution efficiency.

  5. Extraction of density distributions and particle locations from hologram images

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Koji; Ikeda, Koh; Madarame, Haruki [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    1996-10-01

    In this study, the simultaneous measurement technique for three-dimensional density and three-dimensional velocity distributions was evaluated. The Holographic Particle Image Velocimetry (HPIV) was the technique to record the three-dimensional position of the tracer particle on the hologram. When there were density distributions in the interrogation region, the plane optical wave may be modulated because of the difference of the refraction indices. Then, both of the plane wave modulated by density and the spherical wave by particle scatter were interfered with the reference beam, being recorded on the hologram. With reconstructing the hologram, the both of the modulated plane wave and spherical wave were reconstructed. Since the plane wave and spherical wave had low and high frequency, respectively, the two information could be separated using low-pass and high-pass filter. In the experiment, a jet of carbon-dioxide into air with mist were measured. Both mist particle position and the fringe shift caused by the density distribution were well observed, showing the effectiveness of the proposed technique. (author)

  6. Efficient Session Type Guided Distributed Interaction

    Science.gov (United States)

    Sivaramakrishnan, K. C.; Nagaraj, Karthik; Ziarek, Lukasz; Eugster, Patrick

    Recently, there has been much interest in multi-party session types (MPSTs) as a means of rigorously specifying protocols for interaction among multiple distributed participants. By capturing distributed interaction as series of typed interactions, MPSTs allow for the static verification of compliance of corresponding distributed object programs. We observe that explicit control flow information manifested by MPST opens intriguing avenues also for performance enhancements. In this paper, we present a session type assisted performance enhancement framework for distributed object interaction in Java. Experimental evaluation within our distributed runtime infrastructure illustrates the costs and benefits of our composable enhancement strategies.

  7. FAST SS-ILM: A COMPUTATIONALLY EFFICIENT ALGORITHM TO DISCOVER SOCIALLY IMPORTANT LOCATIONS

    Directory of Open Access Journals (Sweden)

    A. S. Dokuz

    2017-11-01

    Full Text Available Socially important locations are places which are frequently visited by social media users in their social media lifetime. Discovering socially important locations provide several valuable information about user behaviours on social media networking sites. However, discovering socially important locations are challenging due to data volume and dimensions, spatial and temporal calculations, location sparseness in social media datasets, and inefficiency of current algorithms. In the literature, several studies are conducted to discover important locations, however, the proposed approaches do not work in computationally efficient manner. In this study, we propose Fast SS-ILM algorithm by modifying the algorithm of SS-ILM to mine socially important locations efficiently. Experimental results show that proposed Fast SS-ILM algorithm decreases execution time of socially important locations discovery process up to 20 %.

  8. Fast Ss-Ilm a Computationally Efficient Algorithm to Discover Socially Important Locations

    Science.gov (United States)

    Dokuz, A. S.; Celik, M.

    2017-11-01

    Socially important locations are places which are frequently visited by social media users in their social media lifetime. Discovering socially important locations provide several valuable information about user behaviours on social media networking sites. However, discovering socially important locations are challenging due to data volume and dimensions, spatial and temporal calculations, location sparseness in social media datasets, and inefficiency of current algorithms. In the literature, several studies are conducted to discover important locations, however, the proposed approaches do not work in computationally efficient manner. In this study, we propose Fast SS-ILM algorithm by modifying the algorithm of SS-ILM to mine socially important locations efficiently. Experimental results show that proposed Fast SS-ILM algorithm decreases execution time of socially important locations discovery process up to 20 %.

  9. Tests of Location Equality Under Non-Identical Distributions

    Directory of Open Access Journals (Sweden)

    İrem YILMAZ

    2017-12-01

    Full Text Available The ANOVA-F test is the most known procedure for comparing at least three population means. However, this conventional test might give misleading results when it’s underlying assumptions are violated. In this study, Welch’s test with trimmed mean, Welch’s test with trimmed mean and a bootstrap-t, newly proposed test and ANOVA-F test were compared in terms of actual Type I error rates under not only non-normality and heteroscedasticity, but also with non-identical distribution shapes. The newly proposed method outperformed ANOVA-F and other alternatives under various situations.

  10. A Moving-Object Index for Efficient Query Processing with PeerWise Location Privacy

    DEFF Research Database (Denmark)

    Lin, Dan; Jensen, Christian S.; Zhang, Rui

    2011-01-01

    attention has been paid to enabling so-called peer-wise privacy—the protection of a user’s location from unauthorized peer users. This paper identifies an important efficiency problem in existing peer-privacy approaches that simply apply a filtering step to identify users that are located in a query range...

  11. Feed efficiency phenotypes in lambs involve changes in ruminal, colonic, and small-intestine-located microbiota.

    Science.gov (United States)

    Perea, K; Perz, K; Olivo, S K; Williams, A; Lachman, M; Ishaq, S L; Thomson, J; Yeoman, C J

    2017-06-01

    Several studies have revealed differences in rumen-located microbes between greatly efficient and inefficient animals; however, how the microbiota vary in the hind gastrointestinal tract (GIT) has only been sparsely explored and how they vary in the small intestine remains to be determined. We therefore sampled the microbiota of the duodenum, jejunum, ileum, colon, and colorectally-obtained feces, in addition to the rumen of 12 lambs that, in a residual feed intake trial, were found to be at either extreme of feed efficiency phenotypes. The 16S rRNA gene (V3-V4 region) profiles of all samples were analyzed and revealed unique microbiota in all GIT locations except the jejunum and ileum (ANOSIM > 0.2, feed efficiency extends beyond the rumen, transcending these regions, and involves increases in both rumen- and colon-located fibrolytic taxa, increases in bifidobacterial species in the small intestine, and reductions in small intestine and distal GIT-located Proteobacteria.

  12. Metrics for Energy Efficiency in Logistics of Freight Distribution

    Directory of Open Access Journals (Sweden)

    Mihaela Stet

    2016-12-01

    Full Text Available The paper is a study on the energy efficiency indicators that can be used for the activities in logistics of freight distribution, at the company level, as well as at macroeconomic level. There are highlighted also some solutions for increasing energy efficiency in distribution channels, starting from technical and logistics management actions, at the company level. There are revealed also the impacts of energy efficiency measures.

  13. Economic analysis of efficient distribution transformer trends

    Energy Technology Data Exchange (ETDEWEB)

    Downing, D.J.; McConnell, B.W.; Barnes, P.R.; Hadley, S.W.; Van Dyke, J.W.

    1998-03-01

    This report outlines an approach that will account for uncertainty in the development of evaluation factors used to identify transformer designs with the lowest total owning cost (TOC). The TOC methodology is described and the most highly variable parameters are discussed. The model is developed to account for uncertainties as well as statistical distributions for the important parameters. Sample calculations are presented. The TOC methodology is applied to data provided by two utilities in order to test its validity.

  14. Location Model for Distribution Centers for Fulfilling Electronic Orders of Fresh Foods under Uncertain Demand

    Directory of Open Access Journals (Sweden)

    Hao Zhang

    2017-01-01

    Full Text Available The problem of locating distribution centers for delivering fresh food as a part of electronic commerce is a strategic decision problem for enterprises. This paper establishes a model for locating distribution centers that considers the uncertainty of customer demands for fresh goods in terms of time-sensitiveness and freshness. Based on the methodology of robust optimization in dealing with uncertain problems, this paper optimizes the location model in discrete demand probabilistic scenarios. In this paper, an improved fruit fly optimization algorithm is proposed to solve the distribution center location problem. An example is given to show that the proposed model and algorithm are robust and can effectively handle the complications caused by uncertain demand. The model proposed in this paper proves valuable both theoretically and practically in the selection of locations of distribution centers.

  15. Energy Efficiency of Distributed Environmental Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Khalifa, H. Ezzat; Isik, Can; Dannenhoffer, John F. III

    2011-02-23

    In this report, we present an analytical evaluation of the potential of occupant-regulated distributed environmental control systems (DECS) to enhance individual occupant thermal comfort in an office building with no increase, and possibly even a decrease in annual energy consumption. To this end we developed and applied several analytical models that allowed us to optimize comfort and energy consumption in partitioned office buildings equipped with either conventional central HVAC systems or occupant-regulated DECS. Our approach involved the following interrelated components: 1. Development of a simplified lumped-parameter thermal circuit model to compute the annual energy consumption. This was necessitated by the need to perform tens of thousands of optimization calculations involving different US climatic regions, and different occupant thermal preferences of a population of ~50 office occupants. Yearly transient simulations using TRNSYS, a time-dependent building energy modeling program, were run to determine the robustness of the simplified approach against time-dependent simulations. The simplified model predicts yearly energy consumption within approximately 0.6% of an equivalent transient simulation. Simulations of building energy usage were run for a wide variety of climatic regions and control scenarios, including traditional “one-size-fits-all” (OSFA) control; providing a uniform temperature to the entire building, and occupant-selected “have-it-your-way” (HIYW) control with a thermostat at each workstation. The thermal model shows that, un-optimized, DECS would lead to an increase in building energy consumption between 3-16% compared to the conventional approach depending on the climate regional and personal preferences of building occupants. Variations in building shape had little impact in the relative energy usage. 2. Development of a gradient-based optimization method to minimize energy consumption of DECS while keeping each occupant

  16. LPPS: A Distributed Cache Pushing Based K-Anonymity Location Privacy Preserving Scheme

    Directory of Open Access Journals (Sweden)

    Ming Chen

    2016-01-01

    Full Text Available Recent years have witnessed the rapid growth of location-based services (LBSs for mobile social network applications. To enable location-based services, mobile users are required to report their location information to the LBS servers and receive answers of location-based queries. Location privacy leak happens when such servers are compromised, which has been a primary concern for information security. To address this issue, we propose the Location Privacy Preservation Scheme (LPPS based on distributed cache pushing. Unlike existing solutions, LPPS deploys distributed cache proxies to cover users mostly visited locations and proactively push cache content to mobile users, which can reduce the risk of leaking users’ location information. The proposed LPPS includes three major process. First, we propose an algorithm to find the optimal deployment of proxies to cover popular locations. Second, we present cache strategies for location-based queries based on the Markov chain model and propose update and replacement strategies for cache content maintenance. Third, we introduce a privacy protection scheme which is proved to achieve k-anonymity guarantee for location-based services. Extensive experiments illustrate that the proposed LPPS achieves decent service coverage ratio and cache hit ratio with lower communication overhead compared to existing solutions.

  17. APPROACHES TO DISTRIBUTION CENTRE'S LOCATION PROBLEM AND ITS ROLE IN GREEN SUPPLY CHAIN MANAGEMENT

    OpenAIRE

    Masa Slabinac

    2013-01-01

    Location represents one of the five integrative areas of a supply chain management that refers to situating of facilit ies within a given space. Facilit ies of each supply chain member differ in the role one plays in supply chain and their objective function. As such, facility location problem solving accounts for different indices included into a model. Distribution centres are facilities of key importance for supply chain management. Proper location decision might add value and create value...

  18. Distribution efficiency of Sorghum marketing in selected areas of ...

    African Journals Online (AJOL)

    Distribution efficiency of Sorghum marketing in selected areas of Adamawa central zone of Nigeria. ... Data were analyzed using descriptive statistics and budgeting techniques. It was observed that ... The study reveals that sorghum marketing system was performing fairly efficient in Adamawa central zone. The study make ...

  19. Using the Efficient Frontier to Obtain the Best Solution for the Storage Location Assignment Problem

    Directory of Open Access Journals (Sweden)

    Marcele Elisa Fontana

    2014-01-01

    Full Text Available The main variables that influence the efficiency of a warehouse are the use of space and the order picking distance. In the literature, there are proposals to add the costs with space and order picking in order to evaluate each alternative for storage location assignment. However, there were problems with the adoption of this methodology, including difficulties in determining the costs and tradeoffs between them. These difficulties can result in solutions that are suboptimal. Based on these facts, this paper proposes a class-based storage process and storage location assignment by a cube-per-order index (COI that analyzes the space required and the total order picking distance by Pareto-optimal calculations. The efficient frontier possibilities allow the reduction of the set of alternatives, and the DM can analyze only the alternatives on efficient frontier.

  20. Distribution Locational Marginal Pricing for Optimal Electric Vehicle Charging through Chance Constrained Mixed-Integer Programming

    DEFF Research Database (Denmark)

    Liu, Zhaoxi; Wu, Qiuwei; Oren, Shmuel S.

    2017-01-01

    This paper presents a distribution locational marginal pricing (DLMP) method through chance constrained mixed-integer programming designed to alleviate the possible congestion in the future distribution network with high penetration of electric vehicles (EVs). In order to represent the stochastic...

  1. Monitoring, protection and fault location in power distribution networks using system-wide measurements

    OpenAIRE

    Janssen, Pierre

    2013-01-01

    This work takes place in the context of distribution grids with high level of distributed generation, for example in microgrids. With high level of distributed generation, it has been shown that selective, fast and sensitive network protection is expected to be more difficult. Furthermore, during system restoration, the accurate fault location could be more challenging to assess, thereby increasing the average outage duration.Thanks to cost reductions and improvement of information and commun...

  2. A neural space vector fault location for parallel double-circuit distribution lines

    Energy Technology Data Exchange (ETDEWEB)

    Sousa Martins, L.; Martins, J.F.; Fernao Pires, V. [Politecnico de Setubal (Portugal). Escola Sup. Tecnol.; Alegria, C.M. [Instituto Superior Tecnico, Lisbon (Portugal)

    2005-03-01

    A new approach to fault location for parallel double-circuit distribution power lines is presented. This approach uses the Clark-Concordia transformation and an artificial neural network based learning algorithm. The {alpha}, {beta}, 0 components of double line currents resulting from the Clarke-Concordia transformation are used to characterize different states of the system. The neural network is trained to map the non-linear relationship existing between fault location and characteristic eigenvalue. The proposed approach is able to identify and to locate different types of faults such as: phase-to-earth, phase-to-phase, two-phase-to-earth and three-phase. Using the eigenvalue as neural network inputs the proposed algorithm locates the fault distance. Results are presented which show the effectiveness of the proposed algorithm for a correct fault location on a parallel double-circuit distribution line. (author)

  3. Detection efficiency of the VLF World-Wide Lightning Location Network (WWLLN: initial case study

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2006-12-01

    Full Text Available An experimental Very Low Frequency (VLF World-Wide Lightning Location Network (WWLLN has been developed through collaborations with research institutions across the world, providing global real-time locations of lightning discharges. As of April 2006, the network included 25 stations providing coverage for much of the Earth. In this paper we examine the detection efficiency of the WWLLN by comparing the locations from this network with lightning location data purchased from a commercial lightning location network operating in New Zealand. Our analysis confirms that WWLLN favours high peak current return stroke lightning discharges, and that discharges with larger currents are observed by more stations across the global network. We then construct a first principles detection efficiency model to describe the WWLLN, combining calibration information for each station with theoretical modelling to describe the expected amplitudes of the VLF sferics observed by the network. This detection efficiency model allows the prediction of the global variation in WWLLN lightning detection, and an estimate of the minimum CG return stroke peak current required to trigger the network. There are strong spatial variations across the globe, primarily due to station density and sensitivity.

    The WWLLN is currently best suited to study the occurrence and impacts of high peak-current lightning. For example, in 2005 about 12% of the global elve-producing lightning will have been located by the network. Since the lightning-EMP which produce elves has a high mean rate (210 per minute it has the potential to significantly influence the ionosphere on regional scales.

  4. Detection efficiency of the VLF World-Wide Lightning Location Network (WWLLN: initial case study

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2006-12-01

    Full Text Available An experimental Very Low Frequency (VLF World-Wide Lightning Location Network (WWLLN has been developed through collaborations with research institutions across the world, providing global real-time locations of lightning discharges. As of April 2006, the network included 25 stations providing coverage for much of the Earth. In this paper we examine the detection efficiency of the WWLLN by comparing the locations from this network with lightning location data purchased from a commercial lightning location network operating in New Zealand. Our analysis confirms that WWLLN favours high peak current return stroke lightning discharges, and that discharges with larger currents are observed by more stations across the global network. We then construct a first principles detection efficiency model to describe the WWLLN, combining calibration information for each station with theoretical modelling to describe the expected amplitudes of the VLF sferics observed by the network. This detection efficiency model allows the prediction of the global variation in WWLLN lightning detection, and an estimate of the minimum CG return stroke peak current required to trigger the network. There are strong spatial variations across the globe, primarily due to station density and sensitivity. The WWLLN is currently best suited to study the occurrence and impacts of high peak-current lightning. For example, in 2005 about 12% of the global elve-producing lightning will have been located by the network. Since the lightning-EMP which produce elves has a high mean rate (210 per minute it has the potential to significantly influence the ionosphere on regional scales.

  5. Efficient GRASP based heuristics for the capacitated continuous location-allocation problem

    Science.gov (United States)

    Luis, Martino; Ramli, Mohammad Fadzli; Saputra, Ruswiati Surya

    2015-05-01

    This paper explores the np-hard capacitated continuous location-allocation problem, where the number of facilities to be located is specified and each of which has a constant capacity. Efficient greedy randomised adaptive search procedure (GRASP) based heuristics are proposed to tackle the problem. A scheme that applies the furthest distance rule (FDR) and self-adjusted threshold parameters to generate initial facility locations that are situated sparsely within GRASP framework is also put forward. The construction of the restricted candidate list (RCL) within GRASP is also guided by applying a concept of restricted regions that prevents new facility locations to be sited too close to the previous selected facility locations. The performance of the proposed GRASP heuristics is evaluated by conducting experiments using data sets taken from the literature typically used for the uncapacitated continuous location-allocation problem. The preliminary computational experiments show that the proposed methods provide encouraging solutions when compared to recently published papers. Some future research avenues on the subject are also briefly highlighted.

  6. Logistics Distribution Center Location Evaluation Based on Genetic Algorithm and Fuzzy Neural Network

    Science.gov (United States)

    Shao, Yuxiang; Chen, Qing; Wei, Zhenhua

    Logistics distribution center location evaluation is a dynamic, fuzzy, open and complicated nonlinear system, which makes it difficult to evaluate the distribution center location by the traditional analysis method. The paper proposes a distribution center location evaluation system which uses the fuzzy neural network combined with the genetic algorithm. In this model, the neural network is adopted to construct the fuzzy system. By using the genetic algorithm, the parameters of the neural network are optimized and trained so as to improve the fuzzy system’s abilities of self-study and self-adaptation. At last, the sampled data are trained and tested by Matlab software. The simulation results indicate that the proposed identification model has very small errors.

  7. Optimal pressure sensor placement in water distribution networks minimizing leak location uncertainty

    OpenAIRE

    Nejjari, Fatiha; Sarrate, Ramon; Blesa, Joaquim

    2015-01-01

    In this paper an optimal sensor placement strategy based on pressure sensitivity matrix analysis and an exhaustive search strategy that maximizes some diagnosis specifications for a water distribution network is presented. An average worst leak expansion distance as a new leak location performance measure has been proposed. This metric is later used to assess the leak location uncertainty provided by a sensor configuration. The method is combined with a clustering technique in order to reduce...

  8. Electricity End Uses, Energy Efficiency, and Distributed Energy Resources Baseline

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Lisa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Morrow, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Deason, Jeff [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schiller, Steven R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leventis, Greg [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Smith, Sarah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leow, Woei Ling [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Levin, Todd [Argonne National Lab. (ANL), Argonne, IL (United States); Plotkin, Steven [Argonne National Lab. (ANL), Argonne, IL (United States); Zhou, Yan [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)

    2017-01-01

    This report was developed by a team of analysts at Lawrence Berkeley National Laboratory, with Argonne National Laboratory contributing the transportation section, and is a DOE EPSA product and part of a series of “baseline” reports intended to inform the second installment of the Quadrennial Energy Review (QER 1.2). QER 1.2 provides a comprehensive review of the nation’s electricity system and cover the current state and key trends related to the electricity system, including generation, transmission, distribution, grid operations and planning, and end use. The baseline reports provide an overview of elements of the electricity system. This report focuses on end uses, electricity consumption, electric energy efficiency, distributed energy resources (DERs) (such as demand response, distributed generation, and distributed storage), and evaluation, measurement, and verification (EM&V) methods for energy efficiency and DERs.

  9. Efficient load rebalancing for distributed file system in Clouds

    Directory of Open Access Journals (Sweden)

    Mr. Mohan S. Deshmukh

    2016-05-01

    Full Text Available Cloud computing is an upcoming era in software industry. It’s a very vast and developing technology. Distributed file systems play an important role in cloud computing applications based on map reduce techniques. While making use of distributed file systems for cloud computing, nodes serves computing and storage functions at the same time. Given file is divided into small parts to use map reduce algorithms in parallel. But the problem lies here since in cloud computing nodes may be added, deleted or modified any time and also operations on files may be done dynamically. This causes the unequal load distribution of load among the nodes which leads to load imbalance problem in distributed file system. Newly developed distributed file system mostly depends upon central node for load distribution but this method is not helpful in large-scale and where chances of failure are more. Use of central node for load distribution creates a problem of single point dependency and chances of performance of bottleneck are more. As well as issues like movement cost and network traffic caused due to migration of nodes and file chunks need to be resolved. So we are proposing algorithm which will overcome all these problems and helps to achieve uniform load distribution efficiently. To verify the feasibility and efficiency of our algorithm we will be using simulation setup and compare our algorithm with existing techniques for the factors like load imbalance factor, movement cost and network traffic.

  10. Geographic location, network patterns and population distribution of rural settlements in Greece

    Science.gov (United States)

    Asimakopoulos, Avraam; Mogios, Emmanuel; Xenikos, Dimitrios G.

    2016-10-01

    Our work addresses the problem of how social networks are embedded in space, by studying the spread of human population over complex geomorphological terrain. We focus on villages or small cities up to a few thousand inhabitants located in mountainous areas in Greece. This terrain presents a familiar tree-like structure of valleys and land plateaus. Cities are found more often at lower altitudes and exhibit preference on south orientation. Furthermore, the population generally avoids flat land plateaus and river beds, preferring locations slightly uphill, away from the plateau edge. Despite the location diversity regarding geomorphological parameters, we find certain quantitative norms when we examine location and population distributions relative to the (man-made) transportation network. In particular, settlements at radial distance ℓ away from road network junctions have the same mean altitude, practically independent of ℓ ranging from a few meters to 10 km. Similarly, the distribution of the settlement population at any given ℓ is the same for all ℓ. Finally, the cumulative distribution of the number of rural cities n(ℓ) is fitted to the Weibull distribution, suggesting that human decisions for creating settlements could be paralleled to mechanisms typically attributed to this particular statistical distribution.

  11. THE PROBABILITY DENSITY LOCATION OF LIGHT AIRCRAFT WITHIN AIRPORT AND THEIR DISTRIBUTION FROM RUNWAY

    Directory of Open Access Journals (Sweden)

    І. Государська

    2011-04-01

    Full Text Available The accident locations of light aircraft with take-off weight less 4 tones were collected. Statistical datawere taken from ADREP (ІСАО, NTSB, ALPA, Aіrclaіms, CAA-UK, ASRS, AІDS databases for 30 year period. Dynamics of accident rate was represented for light aircraft in republics of participantsAgreement of civil aviation (including Ukraine for period from 1982 to 2009. Distributions of location ofthe light aircraft accident from runway end were determined. Bivariate and three-dimensional distributionsof location of light aircraft accident within airports were found

  12. Optimum aggregation of geographically distributed flexible resources in strategic smart-grid/microgrid locations

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu P.; Myers, Kurt S.; Bak-Jensen, Birgitte

    2017-01-01

    This study determines optimum aggregation areas for a given distribution network considering spatial distribution of loads and costs of aggregation. An elitist genetic algorithm combined with a hierarchical clustering and a Thevenin network reduction is implemented to compute strategic locations ...... configuration, steady-state performance of aggregated network is significantly accurate (≈±≈±1.5% error) compared to very high errors associated with forecast of individual consumer demand....

  13. Optimization of distribution transformer efficiency characteristics. Final report, March 1979

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    A method for distribution transformer loss evaluation was derived. The total levalized annual cost method was used and was extended to account properly for conditions of energy cost inflation, peak load growth, and transformer changeout during the evaluation period. The loss costs included were the no-load and load power losses, no-load and load reactive losses, and the energy cost of regulation. The demand and energy components of loss costs were treated separately to account correctly for the diversity of load losses and energy cost inflation. The complete distribution transformer loss evaluation equation is shown, with the nomenclature and definitions for the parameters provided. Tasks described are entitled: Establish Loss Evaluation Techniques; Compile System Cost Parameters; Compile Load Parameters and Loading Policies; Develop Transformer Cost/Performance Relationship; Define Characteristics of Multiple Efficiency Transformer Package; Minimize Life Cycle Cost Based on Single Efficiency Characteristic Transformer Design; Minimize Life Cycle Cost Based on Multiple Efficiency Characteristic Transformer Design; and Interpretation.

  14. Acoustic Emission Source Location Using a Distributed Feedback Fiber Laser Rosette

    Directory of Open Access Journals (Sweden)

    Fang Li

    2013-10-01

    Full Text Available This paper proposes an approach for acoustic emission (AE source localization in a large marble stone using distributed feedback (DFB fiber lasers. The aim of this study is to detect damage in structures such as those found in civil applications. The directional sensitivity of DFB fiber laser is investigated by calculating location coefficient using a method of digital signal analysis. In this, autocorrelation is used to extract the location coefficient from the periodic AE signal and wavelet packet energy is calculated to get the location coefficient of a burst AE source. Normalization is processed to eliminate the influence of distance and intensity of AE source. Then a new location algorithm based on the location coefficient is presented and tested to determine the location of AE source using a Delta (Δ DFB fiber laser rosette configuration. The advantage of the proposed algorithm over the traditional methods based on fiber Bragg Grating (FBG include the capability of: having higher strain resolution for AE detection and taking into account two different types of AE source for location.

  15. Acoustic emission source location using a distributed feedback fiber laser rosette.

    Science.gov (United States)

    Huang, Wenzhu; Zhang, Wentao; Li, Fang

    2013-10-17

    This paper proposes an approach for acoustic emission (AE) source localization in a large marble stone using distributed feedback (DFB) fiber lasers. The aim of this study is to detect damage in structures such as those found in civil applications. The directional sensitivity of DFB fiber laser is investigated by calculating location coefficient using a method of digital signal analysis. In this, autocorrelation is used to extract the location coefficient from the periodic AE signal and wavelet packet energy is calculated to get the location coefficient of a burst AE source. Normalization is processed to eliminate the influence of distance and intensity of AE source. Then a new location algorithm based on the location coefficient is presented and tested to determine the location of AE source using a Delta (Δ) DFB fiber laser rosette configuration. The advantage of the proposed algorithm over the traditional methods based on fiber Bragg Grating (FBG) include the capability of: having higher strain resolution for AE detection and taking into account two different types of AE source for location.

  16. Multiple human location in a distributed binary pyroelectric infrared sensor network

    Science.gov (United States)

    Yang, Bo; Wei, Qifan; Zhang, Meng

    2017-09-01

    This paper proposes a multi-human locating method for distributed wireless sensor network with binary pyroelectric infrared sensors. The uniformly deployed infrared sensor network consists of one sink node and nine sensor nodes, which can detect infrared information of moving human targets. An anti-logic bearing-crossing location and clustering algorithm is proposed to locate different targets. Firstly, dynamic virtual detection lines are generated based on the angular bisector of sensor's FOV(field of view) and all intersection points of these detection lines are primary measurement points. The location of multi-human targets can be achieved by first clustering the primary measurement points and then assigning these clusters to each target, which can simplify the assignment problem from multiple points to several clusters. Finally an anti-logic primary measurement points filtering method is used to get the location result of each target. Simulation and experimental results have shown that the measurement points can be obtained and assigned to different targets effectively, and our proposed location method can locate and track two human targets well.

  17. Integrated Location-Production-Distribution Planning in a Multiproducts Supply Chain Network Design Model

    Directory of Open Access Journals (Sweden)

    Vincent F. Yu

    2015-01-01

    Full Text Available This paper proposes integrated location, production, and distribution planning for the supply chain network design which focuses on selecting the appropriate locations to build a new plant and distribution center while deciding the production and distribution of the product. We examine a multiechelon supply chain that includes suppliers, plants, and distribution centers and develop a mathematical model that aims at minimizing the total cost of the supply chain. In particular, the mathematical model considers the decision of how many plants and distribution centers to open and where to open them, as well as the allocation in each echelon. The LINGO software is used to solve the model for some problem cases. The study conducts various numerical experiments to illustrate the applicability of the developed model. Results show that, in small and medium size of problem, the optimal solution can be found using this solver. Sensitivity analysis is also conducted and shows that customer demand parameter has the greatest impact on the optimal solution.

  18. Energy Efficient Content Distribution in an ISP Network

    OpenAIRE

    Modrzejewski, Remigiusz; Chiaraviglio, Luca; Tahiri, Issam; Giroire, Frédéric; Rouzic, Esther Le; Bonetto, Edoardo; Masumeci, Francesco; Gonzalez, Roberto; Guerro, Carmen

    2013-01-01

    International audience; We study the problem of reducing power consump- tion in an Internet Service Provider (ISP) network by designing the content distribution infrastructure managed by the operator. We propose an algorithm to optimally decide where to cache the content inside the ISP network. We evaluate our solution over two case studies driven by operators feedback. Results show that the energy-efficient design of the content infrastructure brings substantial savings, both in terms of ene...

  19. Efficient channel estimation in massive MIMO systems - a distributed approach

    KAUST Repository

    Al-Naffouri, Tareq Y.

    2016-01-21

    We present two efficient algorithms for distributed estimation of channels in massive MIMO systems. The two cases of 1) generic, and 2) sparse channels is considered. The algorithms estimate the impulse response for each channel observed by the antennas at the receiver (base station) in a coordinated manner by sharing minimal information among neighboring antennas. Simulations demonstrate the superior performance of the proposed methods as compared to other methods.

  20. Optimal Location and Sizing of UPQC in Distribution Networks Using Differential Evolution Algorithm

    Directory of Open Access Journals (Sweden)

    Seyed Abbas Taher

    2012-01-01

    Full Text Available Differential evolution (DE algorithm is used to determine optimal location of unified power quality conditioner (UPQC considering its size in the radial distribution systems. The problem is formulated to find the optimum location of UPQC based on an objective function (OF defined for improving of voltage and current profiles, reducing power loss and minimizing the investment costs considering the OF's weighting factors. Hence, a steady-state model of UPQC is derived to set in forward/backward sweep load flow. Studies are performed on two IEEE 33-bus and 69-bus standard distribution networks. Accuracy was evaluated by reapplying the procedures using both genetic (GA and immune algorithms (IA. Comparative results indicate that DE is capable of offering a nearer global optimal in minimizing the OF and reaching all the desired conditions than GA and IA.

  1. Extension of the Accurate Voltage-Sag Fault Location Method in Electrical Power Distribution Systems

    Directory of Open Access Journals (Sweden)

    Youssef Menchafou

    2016-03-01

    Full Text Available Accurate Fault location in an Electric Power Distribution System (EPDS is important in maintaining system reliability. Several methods have been proposed in the past. However, the performances of these methods either show to be inefficient or are a function of the fault type (Fault Classification, because they require the use of an appropriate algorithm for each fault type. In contrast to traditional approaches, an accurate impedance-based Fault Location (FL method is presented in this paper. It is based on the voltage-sag calculation between two measurement points chosen carefully from the available strategic measurement points of the line, network topology and current measurements at substation. The effectiveness and the accuracy of the proposed technique are demonstrated for different fault types using a radial power flow system. The test results are achieved from the numerical simulation using the data of a distribution line recognized in the literature.

  2. Determining the optimal location for a distribution centre in Allier, France.

    OpenAIRE

    Doriath, Maeva

    2015-01-01

    The current dissertation aims at determining the optimal location of a distribution centre in the department of Allier, in France. This particular topic is inspired by the strategic geographical position of the department in France but also at the European level. This strategic position links to the transportation network whether it be Europe-wide, national-wide or department-wide enables to reach most of the main European area of consumption in less than one day. In order to fully unde...

  3. Optimal Sensor Placement for Leak Location in Water Distribution Networks Using Genetic Algorithms

    OpenAIRE

    Casillas, Myrna V.; Puig, Vicenc; Garza-Castanon, Luis E.; Rosich, Albert

    2013-01-01

    This paper proposes a new sensor placement approach for leak location in water distribution networks (WDNs). The sensor placement problem is formulated as an integer optimization problem. The optimization criterion consists in minimizing the number of non-isolable leaks according to the isolability criteria introduced. Because of the large size and non-linear integer nature of the resulting optimization problem, genetic algorithms (GAs) are used as the solution approach. The obtained results ...

  4. Role of origin and release location in pre-spawning distribution and movements of anadromous alewife

    Science.gov (United States)

    Frank, Holly J.; Mather, M. E.; Smith, Joseph M.; Muth, Robert M.; Finn, John T.

    2011-01-01

    Capturing adult anadromous fish that are ready to spawn from a self sustaining population and transferring them into a depleted system is a common fisheries enhancement tool. The behaviour of these transplanted fish, however, has not been fully evaluated. The movements of stocked and native anadromous alewife, Alosa pseudoharengus (Wilson), were monitored in the Ipswich River, Massachusetts, USA, to provide a scientific basis for this management tool. Radiotelemetry was used to examine the effect of origin (native or stocked) and release location (upstream or downstream) on distribution and movement during the spawning migration. Native fish remained in the river longer than stocked fish regardless of release location. Release location and origin influenced where fish spent time and how they moved. The spatial mosaic of available habitats and the entire trajectory of freshwater movements should be considered to restore effectively spawners that traverse tens of kilometres within coastal rivers.

  5. Location of lightning stroke on OPGW by use of distributed optical fiber sensor

    Science.gov (United States)

    Lu, Lidong; Liang, Yun; Li, Binglin; Guo, Jinghong; Zhang, Hao; Zhang, Xuping

    2014-12-01

    A new method based on a distributed optical fiber sensor (DOFS) to locate the position of lightning stroke on the optical fiber ground wire (OPGW) is proposed and experimentally demonstrated. In the method, the lightning stroke process is considered to be a heat release process at the lightning stroke position, so Brillouin optical time domain reflectometry (BOTDR) with spatial resolution of 2m is used as the distributed temperature sensor. To simulate the lightning stroke process, an electric anode with high pulsed current and a negative electrode (the OPGW) are adopted to form a lightning impulse system with duration time of 200ms. In the experiment, lightning strokes with the quantity of electric discharge of 100 Coul and 200 Coul are generated respectively, and the DOFS can sensitively capture the temperature change of the lightning stroke position in the transient electric discharging process. Experimental results show that DOFS is a feasible instrument to locate the lightning stroke on the OPGW and it has excellent potential for the maintenance of electric power transmission line. Additionally, as the range of lightning stroke is usually within 10cm and the spatial resolution of a typical DOFS is beyond 1m, the temperature characteristics in a small area cannot be accurately represented by a DOFS with a large spatial resolution. Therefore, for further application of distributed optical fiber temperature sensors for lightning stroke location on OPGW, such as BOTDR and ROTDR, it is important to enhance the spatial resolution.

  6. GLN standard as a facilitator of physical location identification within process of distribution

    Directory of Open Access Journals (Sweden)

    Davor Dujak

    2017-09-01

    Full Text Available Background: Distribution, from the business point of view, is a set of decisions and actions that will provide the right products at the right time and place, in line with customer expectations. It is a process that generates significant cost, but also effectively implemented, significantly affects the positive perception of the company. Institute of Logistics and Warehousing (IliM, based on the research results related to the optimization of the distribution network and consulting projects for companies, indicates the high importance of the correct description of the physical location within the supply chains in order to make transport processes more effective. Individual companies work on their own geocoding of warehouse locations and location of their business partners (suppliers, customers, but the lack of standardization in this area causes delays related to delivery problems with reaching the right destination. Furthermore, the cooperating companies do not have a precise indication of the operating conditions of each location, e.g. Time windows of the plant, logistic units accepted at parties, supported transport etc. Lack of this information generates additional costs associated with re-operation and the costs of lost benefits for the lack of goods on time. The solution to this problem seems to be a wide-scale implementation of GS1 standard which is the Global Location Number (GLN, that, thanks to a broad base of information will assist the distribution processes. Material and methods: The results of survey conducted among Polish companies in the second half of 2016 indicate an unsatisfactory degree of implementation of the transport processes, resulting from incorrect or inaccurate description of the location, and thus, a significant number of errors in deliveries. Accordingly, authors studied literature and examined case studies indicating the possibility of using GLN standard to identify the physical location and to show the

  7. [Optimization of electrode location and size on simulation in electric field distribution of atrial defibrillation].

    Science.gov (United States)

    Wang, Cong; Yang, Shengjun; Zheng, Yi; Wu, Xiaomei; Wang, Qunshan; Wei, Daming

    2014-03-01

    A distributed simulation method of electric field based on the atrial defibrillation of the heart modeling and finite element solution is proposed in this study. In order to solve the problem that ordinary clinical trials could not measure the actual distribution of the defibrillation electric field in the heart accurately, this method provides a research tool for electrical defibrillation. A complete atrial anatomical structure in the heart model is used in the research, the finite element method is proceeded to solve; Three parameters: defibrillation threshold voltage, the high field strength rate and the defibrillation threshold energy are set to evaluate the effect of defibrillation. The heart electric field distributions of transvenous atrial defibrillation with different electrode locations or sizes are simulated. The simulation results and the reported results match fairly well, which initially verify the feasibility of this method.

  8. A complex network theory approach for optimizing contamination warning sensor location in water distribution networks

    OpenAIRE

    Nazempour, Rezvan; Monfared, Mohammad Ali Saniee; Zio, Enrico

    2016-01-01

    Drinking water for human health and well-being is crucial. Accidental and intentional water contamination can pose great danger to consumers. Optimal design of a system that can quickly detect the presence of contamination in a water distribution network is very challenging for technical and operational reasons. However, on the one hand improvement in chemical and biological sensor technology has created the possibility of designing efficient contamination detection systems. On the other hand...

  9. Multi criteria decision making methods for location selection of distribution centers

    Directory of Open Access Journals (Sweden)

    Romita Chakraborty

    2013-10-01

    Full Text Available In recent years, major challenges such as, increase in inflexible consumer demands and to improve the competitive advantage, it has become necessary for various industrial organizations all over the world to focus on strategies that will help them achieve cost reduction, continual quality improvement, increased customer satisfaction and on time delivery performance. As a result, selection of the most suitable and optimal facility location for a new organization or expansion of an existing location is one of the most important strategic issues, required to fulfill all of these above mentioned objectives. In order to sustain in the global competitive market of 21st century, many industrial organizations have begun to concentrate on the proper selection of the plant site or best facility location. The best location is that which results in higher economic benefits through increased productivity and good distribution network. When a choice is to be made from among several alternative facility locations, it is necessary to compare their performance characteristics in a decisive way. As the facility location selection problem involves multiple conflicting criteria and a finite set of potential candidate alternatives, different multi-criteria decision-making (MCDM methods can be effectively applied to solve such type of problem. In this paper, four well known MCDM methods have been applied on a facility location selection problem and their relative ranking performances are compared. Because of disagreement in the ranks obtained by the four different MCDM methods a final ranking method based on REGIME has been proposed by the authors to facilitate the decision making process.

  10. Efficiently Building On-line Tools for Distributed Heterogeneous Environments

    Directory of Open Access Journals (Sweden)

    Günther Rackl

    2002-01-01

    Full Text Available Software development is getting more and more complex, especially within distributed middleware-based environments. A major drawback during the overall software development process is the lack of on-line tools, i.e. tools applied as soon as there is a running prototype of an application. The MIMO MIddleware MOnitor provides a solution to this problem by implementing a framework for an efficient development of on-line tools. This paper presents a methodology for developing on-line tools with MIMO. As an example scenario, we choose a distributed medical image reconstruction application, which represents a test case with high performance requirements. Our distributed, CORBA-based application is instrumented for being observed with MIMO and related tools. Additionally, load balancing mechanisms are integrated for further performance improvements. As a result, we obtain an integrated tool environment for observing and steering the image reconstruction application. By using our rapid tool development process, the integration of on-line tools shows to be very convenient and enables an efficient tool deployment.

  11. Sensor Location Problem Optimization for Traffic Network with Different Spatial Distributions of Traffic Information.

    Science.gov (United States)

    Bao, Xu; Li, Haijian; Qin, Lingqiao; Xu, Dongwei; Ran, Bin; Rong, Jian

    2016-10-27

    To obtain adequate traffic information, the density of traffic sensors should be sufficiently high to cover the entire transportation network. However, deploying sensors densely over the entire network may not be realistic for practical applications due to the budgetary constraints of traffic management agencies. This paper describes several possible spatial distributions of traffic information credibility and proposes corresponding different sensor information credibility functions to describe these spatial distribution properties. A maximum benefit model and its simplified model are proposed to solve the traffic sensor location problem. The relationships between the benefit and the number of sensors are formulated with different sensor information credibility functions. Next, expanding models and algorithms in analytic results are performed. For each case, the maximum benefit, the optimal number and spacing of sensors are obtained and the analytic formulations of the optimal sensor locations are derived as well. Finally, a numerical example is proposed to verify the validity and availability of the proposed models for solving a network sensor location problem. The results show that the optimal number of sensors of segments with different model parameters in an entire freeway network can be calculated. Besides, it can also be concluded that the optimal sensor spacing is independent of end restrictions but dependent on the values of model parameters that represent the physical conditions of sensors and roads.

  12. Three-Phase AC Optimal Power Flow Based Distribution Locational Marginal Price: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui; Zhang, Yingchen

    2017-05-17

    Designing market mechanisms for electricity distribution systems has been a hot topic due to the increased presence of smart loads and distributed energy resources (DERs) in distribution systems. The distribution locational marginal pricing (DLMP) methodology is one of the real-time pricing methods to enable such market mechanisms and provide economic incentives to active market participants. Determining the DLMP is challenging due to high power losses, the voltage volatility, and the phase imbalance in distribution systems. Existing DC Optimal Power Flow (OPF) approaches are unable to model power losses and the reactive power, while single-phase AC OPF methods cannot capture the phase imbalance. To address these challenges, in this paper, a three-phase AC OPF based approach is developed to define and calculate DLMP accurately. The DLMP is modeled as the marginal cost to serve an incremental unit of demand at a specific phase at a certain bus, and is calculated using the Lagrange multipliers in the three-phase AC OPF formulation. Extensive case studies have been conducted to understand the impact of system losses and the phase imbalance on DLMPs as well as the potential benefits of flexible resources.

  13. Location-Based Mapping Services to Support Collaboration in Spatially Distributed Workgroups

    Science.gov (United States)

    Meyer, Eike Michael; Wichmann, Daniel; Büsch, Henning; Boll, Susanne

    Mobile devices and systems reached almost every part of our daily life. Following the mobile computing trend, also business logics of distributed, cooperative applications started to move into the mobile client applications. With this shift, the cooperation aspect may also exploit the user’s location and situation context and capabilities of the mobile device and integrate it into the actual cooperation and collaboration. In this paper, we present an approach for a Collaborative Map that exploits the spatial context of the member of a distributed group as a means to visualize and provide collaboration functionality. Then, a number of location-related cooperation methods become feasible such as getting an overview of the spatial distribution of the team members, identify an ad-hoc meeting place nearby, or chat with a group member who has a certain expertise in his or her profile. With CoMa, we move from standard collaboration tools that marginally consider spatial information towards context-aware mobile collaborative systems that can support a wide range of applications such as emergency response, maintenance work or event organization where human resources have to be coordinated in a spatial context and tasks need to be assigned dynamically depending on capabilities and situation context.

  14. High-efficiency reconciliation for continuous variable quantum key distribution

    Science.gov (United States)

    Bai, Zengliang; Yang, Shenshen; Li, Yongmin

    2017-04-01

    Quantum key distribution (QKD) is the most mature application of quantum information technology. Information reconciliation is a crucial step in QKD and significantly affects the final secret key rates shared between two legitimate parties. We analyze and compare various construction methods of low-density parity-check (LDPC) codes and design high-performance irregular LDPC codes with a block length of 106. Starting from these good codes and exploiting the slice reconciliation technique based on multilevel coding and multistage decoding, we realize high-efficiency Gaussian key reconciliation with efficiency higher than 95% for signal-to-noise ratios above 1. Our demonstrated method can be readily applied in continuous variable QKD.

  15. Efficiently Building On-line Tools for Distributed Heterogeneous Environments

    OpenAIRE

    Günther Rackl; Thomas Ludwig; Markus Lindermeier; Alexandros Stamatakis

    2002-01-01

    Software development is getting more and more complex, especially within distributed middleware-based environments. A major drawback during the overall software development process is the lack of on-line tools, i.e. tools applied as soon as there is a running prototype of an application. The MIMO MIddleware MOnitor provides a solution to this problem by implementing a framework for an efficient development of on-line tools. This paper presents a methodology for developing on-line tools with M...

  16. Distributed Detection of Randomly Located Targets in Mobility-Assisted Sensor Networks with Node Mobility Management

    Directory of Open Access Journals (Sweden)

    Jayaweera SudharmanK

    2010-01-01

    Full Text Available Performance gain achieved by adding mobile nodes to a stationary sensor network for target detection depends on factors such as the number of mobile nodes deployed, mobility patterns, speed and energy constraints of mobile nodes, and the nature of the target locations (deterministic or random. In this paper, we address the problem of distributed detection of a randomly located target by a hybrid sensor network. Specifically, we develop two decision-fusion architectures for detection where in the first one, impact of node mobility is taken into account for decisions updating at the fusion center, while in the second model the impact of node mobility is taken at the node level decision updating. The cost of deploying mobile nodes is analyzed in terms of the minimum fraction of mobile nodes required to achieve the desired performance level within a desired delay constraint. Moreover, we consider managing node mobility under given constraints.

  17. Comparison of impedance based fault location methods for power distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Mora-Florez, J. [Electrical Engineering School, Technological University of Pereira (UTP), La Julita, Pereira (Colombia); Melendez, J. [Electronics, Computer Engineering and Automatics Department, University of Girona (UdG), EPS, Campus Montilivi, 17071 Girona (Spain); Carrillo-Caicedo, G. [Electrical Engineering School, Industrial University of Santander (UIS), Cra 27-Cll 9, Bucaramanga (Colombia)

    2008-04-15

    Performance of 10 fault location methods for power distribution systems has been compared. The analyzed methods use only measurements of voltage and current at the substation. Fundamental component during pre-fault and fault are used in these methods to estimate the apparent impedance viewed from the measurement point. Deviation between pre-fault and fault impedance together with the system parameters are used to estimate the distance to the fault point. Fundamental aspects of each method have been considered in the analysis. Power system topology, line and load models and the necessity of additional information are relevant aspects that differentiate one method from another. The 10 selected methods have been implemented, tested and compared in a simulated network. The paper reports the results for several scenarios defined by significant values of the fault location and impedance. The estimated error has been used as a performance index in the comparison. (author)

  18. TGF location, flux and fluence distribution with off-axis angle derived from FERMI data and WWLLN locations

    Science.gov (United States)

    Connell, Paul

    2017-04-01

    The FERMI science support centre has published an online catalogue of 3356 TGFs, along with a subset of 1049 TGFs with a WWLLN temporal association. We have used these tables to create scatter plots and the angular distribution of TGF angles in the FERMI nadir FOV - originally to see what the ASIM/MXGS gamma-ray imager could expect to observe in its FOV. We have also used photon counts from the two FERMI BGO detectors to derive an estimate of TGF flux distribution and fluence with nadir angle. One interesting result is the observation of TGFs out to 50 degrees off-axis, but even more interesting is an angular flux distribution which seems to indicate that a TGF has either a very wide beam angle or that TGFs are narrow beams whose axis has a very wide angular distribution from the earth radial. Whether this indicates TGFs originate by acceleration in macro scale electric fields in storm clouds, or in the micro scale electric fields in lightning leaders, is not clear but the results do call for a more detailed analysis taking FERMI orientation into account. We have not seen any publication of this TGF off-axis angle analysis and show our results for the interest of the TGF research community.

  19. The opponent channel population code of sound location is an efficient representation of natural binaural sounds.

    Science.gov (United States)

    Młynarski, Wiktor

    2015-05-01

    In mammalian auditory cortex, sound source position is represented by a population of broadly tuned neurons whose firing is modulated by sounds located at all positions surrounding the animal. Peaks of their tuning curves are concentrated at lateral position, while their slopes are steepest at the interaural midline, allowing for the maximum localization accuracy in that area. These experimental observations contradict initial assumptions that the auditory space is represented as a topographic cortical map. It has been suggested that a "panoramic" code has evolved to match specific demands of the sound localization task. This work provides evidence suggesting that properties of spatial auditory neurons identified experimentally follow from a general design principle- learning a sparse, efficient representation of natural stimuli. Natural binaural sounds were recorded and served as input to a hierarchical sparse-coding model. In the first layer, left and right ear sounds were separately encoded by a population of complex-valued basis functions which separated phase and amplitude. Both parameters are known to carry information relevant for spatial hearing. Monaural input converged in the second layer, which learned a joint representation of amplitude and interaural phase difference. Spatial selectivity of each second-layer unit was measured by exposing the model to natural sound sources recorded at different positions. Obtained tuning curves match well tuning characteristics of neurons in the mammalian auditory cortex. This study connects neuronal coding of the auditory space with natural stimulus statistics and generates new experimental predictions. Moreover, results presented here suggest that cortical regions with seemingly different functions may implement the same computational strategy-efficient coding.

  20. The opponent channel population code of sound location is an efficient representation of natural binaural sounds.

    Directory of Open Access Journals (Sweden)

    Wiktor Młynarski

    2015-05-01

    Full Text Available In mammalian auditory cortex, sound source position is represented by a population of broadly tuned neurons whose firing is modulated by sounds located at all positions surrounding the animal. Peaks of their tuning curves are concentrated at lateral position, while their slopes are steepest at the interaural midline, allowing for the maximum localization accuracy in that area. These experimental observations contradict initial assumptions that the auditory space is represented as a topographic cortical map. It has been suggested that a "panoramic" code has evolved to match specific demands of the sound localization task. This work provides evidence suggesting that properties of spatial auditory neurons identified experimentally follow from a general design principle- learning a sparse, efficient representation of natural stimuli. Natural binaural sounds were recorded and served as input to a hierarchical sparse-coding model. In the first layer, left and right ear sounds were separately encoded by a population of complex-valued basis functions which separated phase and amplitude. Both parameters are known to carry information relevant for spatial hearing. Monaural input converged in the second layer, which learned a joint representation of amplitude and interaural phase difference. Spatial selectivity of each second-layer unit was measured by exposing the model to natural sound sources recorded at different positions. Obtained tuning curves match well tuning characteristics of neurons in the mammalian auditory cortex. This study connects neuronal coding of the auditory space with natural stimulus statistics and generates new experimental predictions. Moreover, results presented here suggest that cortical regions with seemingly different functions may implement the same computational strategy-efficient coding.

  1. The Opponent Channel Population Code of Sound Location Is an Efficient Representation of Natural Binaural Sounds

    Science.gov (United States)

    Młynarski, Wiktor

    2015-01-01

    In mammalian auditory cortex, sound source position is represented by a population of broadly tuned neurons whose firing is modulated by sounds located at all positions surrounding the animal. Peaks of their tuning curves are concentrated at lateral position, while their slopes are steepest at the interaural midline, allowing for the maximum localization accuracy in that area. These experimental observations contradict initial assumptions that the auditory space is represented as a topographic cortical map. It has been suggested that a “panoramic” code has evolved to match specific demands of the sound localization task. This work provides evidence suggesting that properties of spatial auditory neurons identified experimentally follow from a general design principle- learning a sparse, efficient representation of natural stimuli. Natural binaural sounds were recorded and served as input to a hierarchical sparse-coding model. In the first layer, left and right ear sounds were separately encoded by a population of complex-valued basis functions which separated phase and amplitude. Both parameters are known to carry information relevant for spatial hearing. Monaural input converged in the second layer, which learned a joint representation of amplitude and interaural phase difference. Spatial selectivity of each second-layer unit was measured by exposing the model to natural sound sources recorded at different positions. Obtained tuning curves match well tuning characteristics of neurons in the mammalian auditory cortex. This study connects neuronal coding of the auditory space with natural stimulus statistics and generates new experimental predictions. Moreover, results presented here suggest that cortical regions with seemingly different functions may implement the same computational strategy-efficient coding. PMID:25996373

  2. Detection of Short-Circuit Location in Distribution Mains Line within Functions of Micro-Processor Current Protection

    Directory of Open Access Journals (Sweden)

    F. A. Romaniuk

    2010-01-01

    Full Text Available The paper considers a method for improvement of micro-processor current protection lines that permits to expand a zone of instantaneous short-circuit cut-off  and decrease a number of discriminating elements. In order to reach this purpose the paper proposes additionally to determine a distance up to the short circuit location within functions of the lines concerned. A distance principle for determination of a distance up to the damage place can be laid down in the basis for сalculation of short-circuit location while using an algorithm of orthogonal components or a 3-counting algorithm. The first mentioned algorithm is characterized by higher accuracy but it is sensitive to frequency changes. The 3-counting algorithm is practically insensitive to frequency changes but it is less accurate. Altogether each of the considered algorithms is operational and ensures obtaining of the required information for efficient realization of functions for detection of damage location.The given propositions can be used while developing algorithms for operation of micro-processor current directed protections of distribution mains lines.

  3. A location-inventory model for distribution centers in a three-level supply chain under uncertainty

    Directory of Open Access Journals (Sweden)

    Ali Bozorgi-Amiri

    2013-01-01

    Full Text Available We study a location-inventory problem in a three level supply chain network under uncertainty, which leads to risk. The (r,Q inventory control policy is applied for this problem. Besides, uncertainty exists in different parameters such as procurement, transportation costs, supply, demand and the capacity of different facilities (due to disaster, man-made events and etc. We present a robust optimization model, which concurrently specifies: locations of distribution centers to be opened, inventory control parameters (r,Q, and allocation of supply chain components. The model is formulated as a multi-objective mixed-integer nonlinear programming in order to minimize the expected total cost of such a supply chain network comprising location, procurement, transportation, holding, ordering, and shortage costs. Moreover, we develop an effective solution approach on the basis of multi-objective particle swarm optimization for solving the proposed model. Eventually, computational results of different examples of the problem and sensitivity analysis are exhibited to show the model and algorithm's feasibility and efficiency.

  4. Auction-based distributed efficient economic operations of microgrid systems

    Science.gov (United States)

    Zou, Suli; Ma, Zhongjing; Liu, Xiangdong

    2014-12-01

    This paper studies the economic operations of the microgrid in a distributed way such that the operational schedule of each of the units, like generators, load units, storage units, etc., in a microgrid system, is implemented by autonomous agents. We apply and generalise the progressive second price (PSP) auction mechanism which was proposed by Lazar and Semret to efficiently allocate the divisible network resources. Considering the economic operation for the microgrid systems, the generators play as sellers to supply energy and the load units play as the buyers to consume energy, while a storage unit, like battery, super capacitor, etc., may transit between buyer and seller, such that it is a buyer when it charges and becomes a seller when it discharges. Furthermore in a connected mode, each individual unit competes against not only the other individual units in the microgrid but also the exogenous main grid possessing fixed electricity price and infinite trade capacity; that is to say, the auctioneer assigns the electricity among all individual units and the main grid with respect to the submitted bid strategies of all individual units in the microgrid in an economic way. Due to these distinct characteristics, the underlying auction games are distinct from those studied in the literature. We show that under mild conditions, the efficient economic operation strategy is a Nash equilibrium (NE) for the PSP auction games, and propose a distributed algorithm under which the system can converge to an NE. We also show that the performance of worst NE can be bounded with respect to the system parameters, say the energy trading price with the main grid, and based upon that, the implemented NE is unique and efficient under some conditions.

  5. Statistical Feature Extraction for Fault Locations in Nonintrusive Fault Detection of Low Voltage Distribution Systems

    Directory of Open Access Journals (Sweden)

    Hsueh-Hsien Chang

    2017-04-01

    Full Text Available This paper proposes statistical feature extraction methods combined with artificial intelligence (AI approaches for fault locations in non-intrusive single-line-to-ground fault (SLGF detection of low voltage distribution systems. The input features of the AI algorithms are extracted using statistical moment transformation for reducing the dimensions of the power signature inputs measured by using non-intrusive fault monitoring (NIFM techniques. The data required to develop the network are generated by simulating SLGF using the Electromagnetic Transient Program (EMTP in a test system. To enhance the identification accuracy, these features after normalization are given to AI algorithms for presenting and evaluating in this paper. Different AI techniques are then utilized to compare which identification algorithms are suitable to diagnose the SLGF for various power signatures in a NIFM system. The simulation results show that the proposed method is effective and can identify the fault locations by using non-intrusive monitoring techniques for low voltage distribution systems.

  6. Distributed measurement of acoustic vibration location with frequency multiplexed phase-OTDR

    Science.gov (United States)

    Iida, Daisuke; Toge, Kunihiro; Manabe, Tetsuya

    2017-07-01

    All-fiber distributed vibration sensing is attracting attention in relation to structural health monitoring because it is cost effective, offers high coverage of the monitored area and can detect various structural problems. And in particular the demand for high-speed vibration sensing operating at more than 10 kHz has increased because high frequency vibration indicates high energy and severe trouble in the monitored object. Optical fiber vibration sensing with phase-sensitive optical time domain reflectometry (phase-OTDR) has long been studied because it can be used for distributed vibration sensing in optical fiber. However, pulse reflectometry such as OTDR cannot measure high-frequency vibration whose cycle is shorter than the repetition time of the OTDR. That is, the maximum detectable frequency depends on fiber length. In this paper, we describe a vibration sensing technique with frequency-multiplexed OTDR that can detect the entire distribution of a high-frequency vibration thus allowing us to locate a high-speed vibration point. We can measure the position, frequency and dynamic change of a high-frequency vibration whose cycle is shorter than the repetition time. Both frequency and position are visualized simultaneously for a 5-km fiber with an 80-kHz frequency response and a 20-m spatial resolution.

  7. The optimal number, type and location of devices in automation of electrical distribution networks

    Directory of Open Access Journals (Sweden)

    Popović Željko N.

    2015-01-01

    Full Text Available This paper presents the mixed integer linear programming based model for determining optimal number, type and location of remotely controlled and supervised devices in distribution networks in the presence of distributed generators. The proposed model takes into consideration a number of different devices simultaneously (remotely controlled circuit breakers/reclosers, sectionalizing switches, remotely supervised and local fault passage indicators along with the following: expected outage cost to consumers and producers due to momentary and long-term interruptions, automated device expenses (capital investment, installation, and annual operation and maintenance costs, number and expenses of crews involved in the isolation and restoration process. Furthermore, the other possible benefits of each of automated device are also taken into account (e.g., benefits due to decreasing the cost of switching operations in normal conditions. The obtained numerical results emphasize the importance of consideration of different types of automation devices simultaneously. They also show that the proposed approach have a potential to improve the process of determining of the best automation strategy in real life distribution networks.

  8. Economic feasibility of an energy efficiency project for a steam distribution system in a chemical industry

    Directory of Open Access Journals (Sweden)

    Flavia Melo Menezes

    2017-12-01

    Full Text Available The burning of fossil fuels majorly contributes to the increase in global warming, and it represents 93% of greenhouse gases emissions in the chemical industry. Most of the energy demand in this sector is associated with steam systems, where 1/3 of the energy efficiency opportunities are located in its distribution system. However, most of the literature focuses on the design of new systems. Those that deal with existing systems, not always use simple and available methods. Furthermore, they address energy losses of steam systems only due to thermal insulation, ignoring those due to leakages of traps. Given this context, the purpose of this paper is to determine the economic feasibility of an energy efficiency project for a steam distribution system in a chemical industry, located in the metropolitan region of Salvador, Brazil. First, the energy lost in the steam distribution system through heat insulation and steam traps was estimated by applying thermodynamic principles, and technic consulting, respectively. Then, investments were estimated using commercial prices for new thermal insulation and steam traps. Finally, an economic evaluation of the improvement project was made, through the construction of a cash flow, and calculation of economic indicators: payback time, net present value (NPV, and internal rate of return (IRR. Economic indicators showed that the project is economically viable. The NPV and IRR reached approximately 5 million reais, and 66% per year, respectively. Additionally, this project also had social and environmental benefits, such as a reduction in greenhouse gases emissions, and increased local water availability.

  9. BECSI: Bandwidth Efficient Certificate Status Information Distribution Mechanism for VANETs

    Directory of Open Access Journals (Sweden)

    Carlos Gañán

    2013-01-01

    Full Text Available Certificate revocation is a challenging task, especiallyin mobile network environments such as vehicular ad Hoc networks (VANETs.According to the IEEE 1609.2 security standard for VANETs, public keyinfrastructure (PKI will provide this functionality by means of certificate revocation lists (CRLs.When a certificate authority (CAneeds to revoke a certificate, itglobally distributes CRLs.Transmitting these lists pose a problem as they require high update frequencies and a lot of bandwidth. In this article, we propose BECSI, aBandwidth Efficient Certificate Status Informationmechanism to efficiently distributecertificate status information (CSI in VANETs.By means of Merkle hash trees (MHT, BECSI allowsto retrieve authenticated CSI not onlyfrom the infrastructure but also from vehicles actingas mobile repositories.Since these MHTs are significantly smaller than the CRLs, BECSIreduces the load on the CSI repositories and improves the response time for the vehicles.Additionally, BECSI improves the freshness of the CSIby combining the use of delta-CRLs with MHTs.Thus, vehicles that have cached the most current CRLcan download delta-CRLs to have a complete list of revoked certificates.Once a vehicle has the whole list of revoked certificates, it can act as mobile repository.

  10. Efficient estimation of smooth distributions from coarsely grouped data.

    Science.gov (United States)

    Rizzi, Silvia; Gampe, Jutta; Eilers, Paul H C

    2015-07-15

    Ungrouping binned data can be desirable for many reasons: Bins can be too coarse to allow for accurate analysis; comparisons can be hindered when different grouping approaches are used in different histograms; and the last interval is often wide and open-ended and, thus, covers a lot of information in the tail area. Age group-specific disease incidence rates and abridged life tables are examples of binned data. We propose a versatile method for ungrouping histograms that assumes that only the underlying distribution is smooth. Because of this modest assumption, the approach is suitable for most applications. The method is based on the composite link model, with a penalty added to ensure the smoothness of the target distribution. Estimates are obtained by maximizing a penalized likelihood. This maximization is performed efficiently by a version of the iteratively reweighted least-squares algorithm. Optimal values of the smoothing parameter are chosen by minimizing Akaike's Information Criterion. We demonstrate the performance of this method in a simulation study and provide several examples that illustrate the approach. Wide, open-ended intervals can be handled properly. The method can be extended to the estimation of rates when both the event counts and the exposures to risk are grouped. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.

  11. Efficient Vaccine Distribution Based on a Hybrid Compartmental Model.

    Directory of Open Access Journals (Sweden)

    Zhiwen Yu

    Full Text Available To effectively and efficiently reduce the morbidity and mortality that may be caused by outbreaks of emerging infectious diseases, it is very important for public health agencies to make informed decisions for controlling the spread of the disease. Such decisions must incorporate various kinds of intervention strategies, such as vaccinations, school closures and border restrictions. Recently, researchers have paid increased attention to searching for effective vaccine distribution strategies for reducing the effects of pandemic outbreaks when resources are limited. Most of the existing research work has been focused on how to design an effective age-structured epidemic model and to select a suitable vaccine distribution strategy to prevent the propagation of an infectious virus. Models that evaluate age structure effects are common, but models that additionally evaluate geographical effects are less common. In this paper, we propose a new SEIR (susceptible-exposed-infectious šC recovered model, named the hybrid SEIR-V model (HSEIR-V, which considers not only the dynamics of infection prevalence in several age-specific host populations, but also seeks to characterize the dynamics by which a virus spreads in various geographic districts. Several vaccination strategies such as different kinds of vaccine coverage, different vaccine releasing times and different vaccine deployment methods are incorporated into the HSEIR-V compartmental model. We also design four hybrid vaccination distribution strategies (based on population size, contact pattern matrix, infection rate and infectious risk for controlling the spread of viral infections. Based on data from the 2009-2010 H1N1 influenza epidemic, we evaluate the effectiveness of our proposed HSEIR-V model and study the effects of different types of human behaviour in responding to epidemics.

  12. Location, Location, Location!

    Science.gov (United States)

    Ramsdell, Kristin

    2004-01-01

    Of prime importance in real estate, location is also a key element in the appeal of romances. Popular geographic settings and historical periods sell, unpopular ones do not--not always with a logical explanation, as the author discovered when she conducted a survey on this topic last year. (Why, for example, are the French Revolution and the…

  13. Commercial milk distribution profiles and production locations. Hanford Environmental Dose Reconstruction Project

    Energy Technology Data Exchange (ETDEWEB)

    Deonigi, D.E.; Anderson, D.M.; Wilfert, G.L.

    1994-04-01

    The Hanford Environmental Dose Reconstruction (HEDR) Project was established to estimate radiation doses that people could have received from nuclear operations at the Hanford Site since 1944. For this period iodine-131 is the most important offsite contributor to radiation doses from Hanford operations. Consumption of milk from cows that ate vegetation contaminated by iodine-131 is the dominant radiation pathway for individuals who drank milk (Napier 1992). Information has been developed on commercial milk cow locations and commercial milk distribution during 1945 and 1951. The year 1945 was selected because during 1945 the largest amount of iodine-131 was released from Hanford facilities in a calendar year (Heeb 1993); therefore, 1945 was the year in which an individual was likely to have received the highest dose. The year 1951 was selected to provide data for comparing the changes that occurred in commercial milk flows (i.e., sources, processing locations, and market areas) between World War II and the post-war period. To estimate the doses people could have received from this milk flow, it is necessary to estimate the amount of milk people consumed, the source of the milk, the specific feeding regime used for milk cows, and the amount of iodine-131 contamination deposited on feed.

  14. Tsunami hazard assessments with consideration of uncertain earthquake slip distribution and location

    Science.gov (United States)

    Sepúlveda, Ignacio; Liu, Philip L.-F.; Grigoriu, Mircea; Pritchard, Matthew

    2017-09-01

    This paper proposes a stochastic approach to model the earthquake uncertainties in terms of the rupture location and the slip distribution for a future event, with an expected earthquake magnitude. Once the statistical properties of earthquake uncertainties are described, they are then propagated into the tsunami response and the inundation at assessed coastal areas. The slip distribution is modeled as a random field within a nonrectangular rupture area. The Karhunen-Lòeve (K-L) expansion method is used to generate samples of the random slip, and a translation model is employed to obtain target probability properties. A strategy is developed to specify the accuracy of the random samples in terms of numbers of subfaults of the rupture area and the truncation of the K-L expansion. The propagation of uncertainty into the tsunami response is performed by means of a Stochastic Reduced Order Model. To illustrate the methodology, we investigated a study case in north Chile. We first demonstrate that the stochastic approach generates consistent earthquake samples with respect to the target probability properties. We also show that the results obtained from SROM are more accurate than those obtained with classic Monte Carlo simulations. To validate the methodology, we compared the simulated tsunamis and the tsunami records for the 2014 Chilean earthquake. Results show that leading wave measurements fall within the tsunami sample space. At later times, however, there are mismatches between measured data and the simulated results, suggesting that other sources of uncertainties are as relevant as the uncertainty of earthquakes.

  15. Distributed solar photovoltaic array location and extent dataset for remote sensing object identification

    Science.gov (United States)

    Bradbury, Kyle; Saboo, Raghav; L. Johnson, Timothy; Malof, Jordan M.; Devarajan, Arjun; Zhang, Wuming; M. Collins, Leslie; G. Newell, Richard

    2016-12-01

    Earth-observing remote sensing data, including aerial photography and satellite imagery, offer a snapshot of the world from which we can learn about the state of natural resources and the built environment. The components of energy systems that are visible from above can be automatically assessed with these remote sensing data when processed with machine learning methods. Here, we focus on the information gap in distributed solar photovoltaic (PV) arrays, of which there is limited public data on solar PV deployments at small geographic scales. We created a dataset of solar PV arrays to initiate and develop the process of automatically identifying solar PV locations using remote sensing imagery. This dataset contains the geospatial coordinates and border vertices for over 19,000 solar panels across 601 high-resolution images from four cities in California. Dataset applications include training object detection and other machine learning algorithms that use remote sensing imagery, developing specific algorithms for predictive detection of distributed PV systems, estimating installed PV capacity, and analysis of the socioeconomic correlates of PV deployment.

  16. Distributed solar photovoltaic array location and extent dataset for remote sensing object identification.

    Science.gov (United States)

    Bradbury, Kyle; Saboo, Raghav; L Johnson, Timothy; Malof, Jordan M; Devarajan, Arjun; Zhang, Wuming; M Collins, Leslie; G Newell, Richard

    2016-12-06

    Earth-observing remote sensing data, including aerial photography and satellite imagery, offer a snapshot of the world from which we can learn about the state of natural resources and the built environment. The components of energy systems that are visible from above can be automatically assessed with these remote sensing data when processed with machine learning methods. Here, we focus on the information gap in distributed solar photovoltaic (PV) arrays, of which there is limited public data on solar PV deployments at small geographic scales. We created a dataset of solar PV arrays to initiate and develop the process of automatically identifying solar PV locations using remote sensing imagery. This dataset contains the geospatial coordinates and border vertices for over 19,000 solar panels across 601 high-resolution images from four cities in California. Dataset applications include training object detection and other machine learning algorithms that use remote sensing imagery, developing specific algorithms for predictive detection of distributed PV systems, estimating installed PV capacity, and analysis of the socioeconomic correlates of PV deployment.

  17. Aerosol number size distributions over a coastal semi urban location: Seasonal changes and ultrafine particle bursts

    Energy Technology Data Exchange (ETDEWEB)

    Babu, S. Suresh, E-mail: s_sureshbabu@vssc.gov.in [Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram 695022 (India); Kompalli, Sobhan Kumar [Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram 695022 (India); Moorthy, K. Krishna [Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bangalore 560 012 (India)

    2016-09-01

    Number-size distribution is one of the important microphysical properties of atmospheric aerosols that influence aerosol life cycle, aerosol-radiation interaction as well as aerosol-cloud interactions. Making use of one-yearlong measurements of aerosol particle number-size distributions (PNSD) over a broad size spectrum (~ 15–15,000 nm) from a tropical coastal semi-urban location-Trivandrum (Thiruvananthapuram), the size characteristics, their seasonality and response to mesoscale and synoptic scale meteorology are examined. While the accumulation mode contributed mostly to the annual mean concentration, ultrafine particles (having diameter < 100 nm) contributed as much as 45% to the total concentration, and thus constitute a strong reservoir, that would add to the larger particles through size transformation. The size distributions were, in general, bimodal with well-defined modes in the accumulation and coarse regimes, with mode diameters lying in the range 141 to 167 nm and 1150 to 1760 nm respectively, in different seasons. Despite the contribution of the coarse sized particles to the total number concentration being meager, they contributed significantly to the surface area and volume, especially during transport of marine air mass highlighting the role of synoptic air mass changes. Significant diurnal variation occurred in the number concentrations, geometric mean diameters, which is mostly attributed to the dynamics of the local coastal atmospheric boundary layer and the effect of mesoscale land/sea breeze circulation. Bursts of ultrafine particles (UFP) occurred quite frequently, apparently during periods of land-sea breeze transitions, caused by the strong mixing of precursor-rich urban air mass with the cleaner marine air mass; the resulting turbulence along with boundary layer dynamics aiding the nucleation. These ex-situ particles were observed at the surface due to the transport associated with boundary layer dynamics. The particle growth rates from

  18. Sub-micron particle number size distribution characteristics at two urban locations in Leicester

    Science.gov (United States)

    Hama, Sarkawt M. L.; Cordell, Rebecca L.; Kos, Gerard P. A.; Weijers, E. P.; Monks, Paul S.

    2017-09-01

    The particle number size distribution (PNSD) of atmospheric particles not only provides information about sources and atmospheric processing of particles, but also plays an important role in determining regional lung dose. Owing to the importance of PNSD in understanding particulate pollution two short-term campaigns (March-June 2014) measurements of sub-micron PNSD were conducted at two urban background locations in Leicester, UK. At the first site, Leicester Automatic Urban Rural Network (AURN), the mean number concentrations of nucleation, Aitken, accumulation modes, the total particles, equivalent black carbon (eBC) mass concentrations were 2002, 3258, 1576, 6837 # cm-3, 1.7 μg m-3, respectively, and at the second site, Brookfield (BF), were 1455, 2407, 874, 4737 # cm-3, 0.77 μg m-3, respectively. The total particle number was dominated by the nucleation and Aitken modes, with both consisting of 77%, and 81% of total number concentrations at AURN and BF sites, respectively. This behaviour could be attributed to primary emissions (traffic) of ultrafine particles and the temporal evolution of mixing layer. The size distribution at the AURN site shows bimodal distribution at 22 nm with a minor peak at 70 nm. The size distribution at BF site, however, exhibits unimodal distribution at 35 nm. This study has for the first time investigated the effect of Easter holiday on PNSD in UK. The temporal variation of PNSD demonstrated a good degree of correlation with traffic-related pollutants (NOX, and eBC at both sites). The meteorological conditions, also had an impact on the PNSD and eBC at both sites. During the measurement period, the frequency of NPF events was calculated to be 13.3%, and 22.2% at AURN and BF sites, respectively. The average value of formation and growth rates of nucleation mode particles were 1.3, and 1.17 cm-3 s-1 and 7.42, and 5.3 nm h-1 at AURN, and BF sites, respectively. It can suggested that aerosol particles in Leicester originate mainly

  19. COORDINATED LOCATION, DISTRIBUTION AND INVENTORY DECISIONS IN SUPPLY CHAIN NETWORK DESIGN: A MULTI-OBJECTIVE APPROACH

    Directory of Open Access Journals (Sweden)

    G. Reza Nasiri

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: This research presents an integrated multi-objective distribution model for use in simultaneous strategic and operational food supply chain (SC planning. The proposed method is adopted to allow use of a performance measurement system that includes conflicting objectives such as distribution costs, customer service level (safety stock holding, resource utilisation, and the total delivery time, with reference to multiple warehouse capacities and uncertain forecast demands. To deal with these objectives and enable the decision makers (DMs to evaluate a greater number of alternative solutions, three different approaches are implemented in the proposed solution procedure. A detailed case study derived from food industrial data is used to illustrate the preference of the proposed approach. The proposed method yields an efficient solution and an overall degree of DMs’ satisfaction with the determined objective values.

    AFRIKAANSE OPSOMMING: Die navorsing behandel ’n geïntegreerde multidoelwit distribusiemodel vir strategiese beplanning van ’n voedseltoevoerketting. Om met die model doelmatig te werk, moet ’n versameling van randvoorwaardes hanteer word om die saamgestelde optimiseringsdoelwit te bereik teen ’n agtergrond van uiteenlopende sienings.

  20. Facility Location Modeling in Multi-Echelon Distribution System: A Case Study of Indonesian Liquefied Petroleum Gas Supply Chain

    Directory of Open Access Journals (Sweden)

    Ilyas Masudin

    2013-04-01

    Full Text Available This paper presents model of Indonesian LPG supply chain by opening new facilities (new echelon taking into account the current facilities. The objective is to investigate the relation between distribution costs such as transportation, inventory cost and facility location in Indonesian multi-echelon LPG supply chain. Fixed-charged capacitated facility location problem is used to determine the optimal solution of the proposed model. In the sensitivity analysis, it is reported that the trade-offs between facility locations and distribution costs are exist. Results report that as the number of facility increases, total transportation and inventory cost also increase.

  1. Where-Fi: a dynamic energy-efficient multimedia distribution framework for MANETs

    Science.gov (United States)

    Mohapatra, Shivajit; Carbunar, Bogdan; Pearce, Michael; Chaudhri, Rohit; Vasudevan, Venu

    2008-01-01

    Next generation mobile ad-hoc applications will revolve around users' need for sharing content/presence information with co-located devices. However, keeping such information fresh requires frequent meta-data exchanges, which could result in significant energy overheads. To address this issue, we propose distributed algorithms for energy efficient dissemination of presence and content usage information between nodes in mobile ad-hoc networks. First, we introduce a content dissemination protocol (called CPMP) for effectively distributing frequent small meta-data updates between co-located devices using multicast. We then develop two distributed algorithms that use the CPMP protocol to achieve "phase locked" wake up cycles for all the participating nodes in the network. The first algorithm is designed for fully-connected networks and then extended in the second to handle hidden terminals. The "phase locked" schedules are then exploited to adaptively transition the network interface to a deep sleep state for energy savings. We have implemented a prototype system (called "Where-Fi") on several Motorola Linux-based cell phone models. Our experimental results show that for all network topologies our algorithms were able to achieve "phase locking" between nodes even in the presence of hidden terminals. Moreover, we achieved battery lifetime extensions of as much as 28% for fully connected networks and about 20% for partially connected networks.

  2. Optimal sensor placement for leak location in water distribution networks using genetic algorithms.

    Science.gov (United States)

    Casillas, Myrna V; Puig, Vicenç; Garza-Castañón, Luis E; Rosich, Albert

    2013-11-04

    This paper proposes a new sensor placement approach for leak location in water distribution networks (WDNs). The sensor placement problem is formulated as an integer optimization problem. The optimization criterion consists in minimizing the number of non-isolable leaks according to the isolability criteria introduced. Because of the large size and non-linear integer nature of the resulting optimization problem, genetic algorithms (GAs) are used as the solution approach. The obtained results are compared with a semi-exhaustive search method with higher computational effort, proving that GA allows one to find near-optimal solutions with less computational load. Moreover, three ways of increasing the robustness of the GA-based sensor placement method have been proposed using a time horizon analysis, a distance-based scoring and considering different leaks sizes. A great advantage of the proposed methodology is that it does not depend on the isolation method chosen by the user, as long as it is based on leak sensitivity analysis. Experiments in two networks allow us to evaluate the performance of the proposed approach.

  3. Geophysical flows under location uncertainty, Part II: Quasi-geostrophy and efficient ensemble spreading

    CERN Document Server

    Resseguier, Valentin; Chapron, Bertrand

    2016-01-01

    Models under location uncertainty are derived assuming that a component of the velocity is uncorrelated in time. The material derivative is accordingly modified to include an advection correction, inhomogeneous and anisotropic diffusion terms and a multiplicative noise contribution. In this paper, simplified geophysical dynamics are derived from a Boussinesq model under location uncertainty. Invoking usual scaling approximations and a moderate influence of the subgrid terms, stochastic formulations are obtained for the stratified Quasi-Geostrophy (QG) and the Surface Quasi-Geostrophy (SQG) models. Based on numerical simulations, benefits of the proposed stochastic formalism are demonstrated. A single realization of models under location uncertainty can restore small-scale structures. An ensemble of realizations further helps to assess model error prediction and outperforms perturbed deterministic models by one order of magnitude. Such a high uncertainty quantification skill is of primary interests for assimil...

  4. Efficient Top-k Spatial Locality Search for Co-located Spatial Web Objects

    DEFF Research Database (Denmark)

    Qu, Qiang; Liu, Siyuan; Yang, Bin

    2014-01-01

    In step with the web being used widely by mobile users, user location is becoming an essential signal in services, including local intent search. Given a large set of spatial web objects consisting of a geographical location and a textual description (e.g., online business directory entries...... sets with more textually relevant objects render these studies inapplicable. We propose localitySearch, a query that returns top-k sets of spatial web objects and integrates spatial distance and textual relevance in one ranking function. We show that computing the query is NP-hard, and we present two...

  5. Efficient design and inference in distributed Bayesian networks: an overview

    NARCIS (Netherlands)

    de Oude, P.; Groen, F.C.A.; Pavlin, G.; Bezhanishvili, N.; Löbner, S.; Schwabe, K.; Spada, L.

    2011-01-01

    This paper discusses an approach to distributed Bayesian modeling and inference, which is relevant for an important class of contemporary real world situation assessment applications. By explicitly considering the locality of causal relations, the presented approach (i) supports coherent distributed

  6. An Efficient Local Algorithm for Distributed Multivariate Regression

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper offers a local distributed algorithm for multivariate regression in large peer-to-peer environments. The algorithm is designed for distributed...

  7. Determining irrigation distribution uniformity and efficiency for nurseries

    Science.gov (United States)

    R. Thomas Fernandez

    2010-01-01

    A simple method for testing the distribution uniformity of overhead irrigation systems is described. The procedure is described step-by-step along with an example. Other uses of distribution uniformity testing are presented, as well as common situations that affect distribution uniformity and how to alleviate them.

  8. Effect of locus of resource control on operational efficiency in distributed operations

    Science.gov (United States)

    Geoffroy, A. L.

    1991-01-01

    The following topics are presented in view graph form: space network control (SNC) usage in the Advanced Tracking and Data Relay Satellite (ATDRSS) era; an acronym and icon list; demands of the SNC; tightness of resources coupling; sharing information and sharing control; potential ways of distributing control; efficiency problems unrelated to distribution of control; efficiency problems related to distribution of control; and recommendations.

  9. Biomass bale stack and field outlet locations assessment for efficient infield logistics

    Science.gov (United States)

    Harvested hay or biomass are traditionally baled for better handling and they are transported to the outlet for final utilization. For better management of bale logistics, producers often aggregate bales into stacks so that bale-hauling equipment can haul multiple bales for improved efficiency. Obje...

  10. Location-Routing Problem with Simultaneous Home Delivery and Customer’s Pickup for City Distribution of Online Shopping Purchases

    Directory of Open Access Journals (Sweden)

    Lin Zhou

    2016-08-01

    Full Text Available With the increasing interest in online shopping, the Last Mile delivery is regarded as one of the most expensive and pollutive—and yet the least efficient—stages of the e-commerce supply chain. To address this challenge, a novel location-routing problem with simultaneous home delivery and customer’s pickup is proposed. This problem aims to build a more effective Last Mile distribution system by providing two kinds of service options when delivering packages to customers. To solve this specific problem, a hybrid evolution search algorithm by combining genetic algorithm (GA and local search (LS is presented. In this approach, a diverse population generation algorithm along with a two-phase solution initialization heuristic is first proposed to give high quality initial population. Then, advantaged solution representation, individual evaluation, crossover and mutation operations are designed to enhance the evolution and search efficiency. Computational experiments based on a large family of instances are conducted, and the results obtained indicate the validity of the proposed model and method.

  11. A Collection-Distribution Center Location and Allocation Optimization Model in Closed-Loop Supply Chain for Chinese Beer Industry

    Directory of Open Access Journals (Sweden)

    Kai Kang

    2017-01-01

    Full Text Available Recycling waste products is an environmental-friendly activity that can result in manufacturing cost saving and economic efficiency improving. In the beer industry, recycling bottles can reduce manufacturing cost and the industry’s carbon footprint. This paper presents a model for a collection-distribution center location and allocation problem in a closed-loop supply chain for the beer industry under a fuzzy random environment, in which the objectives are to minimize total costs and transportation pollution. Both random and fuzzy uncertainties, for which return rate and disposal rate are considered fuzzy random variables, are jointly handled in this paper to ensure a more practical problem solution. A heuristic algorithm based on priority-based global-local-neighbor particle swarm optimization (pb-glnPSO is applied to ensure reliable solutions for this NP-hard problem. A beer company case study is given to illustrate the application of the proposed model and to demonstrate the priority-based global-local-neighbor particle swarm optimization.

  12. An efficient and accurate new method for locating the F3 position for prefrontal TMS applications.

    Science.gov (United States)

    Beam, William; Borckardt, Jeffrey J; Reeves, Scott T; George, Mark S

    2009-01-01

    The International 10-20 system is a method for standardized placement of electroencephalogram (EEG) electrodes. The 10-20 system correlates external skull locations with the underlying cortical areas. This system accounts for variability in patient skull size by using certain percentages of the circumference and distances between four basic anatomical landmarks. This 10-20 system has recently been used in transcranial magnetic stimulation (TMS) research for locating specific cortical areas. In the treatment of depression (and some types of pain), the desired placement of the TMS coil is often above the left dorsalateral prefrontal cortex (DLPFC) which corresponds to the F3 location given by the 10-20 system. However, for an administrator with little experience with the 10-20 system, the numerous measurements and calculations can be excessively time-consuming. Additionally, with more measurements comes more opportunity for human error. For this reason we have developed a new, simpler and faster way to find the F3 position using only three skull measurements. In this paper, we describe and illustrate the application of the new F3 location system, provide the formulas used in the calculation of the F3 position, and summarize data from 10 healthy adults. After using both the International 10-20 system and this new method, it appears that the new method is sufficiently accurate; however, future investigations may be warranted to conduct more in dept analyses of the method's utility and potential limitations. This system requires less time and training to find the optimal position for prefrontal coil placement and it saves considerable time compared to the 10-20 EEG system.

  13. Exergy efficient production, storage and distribution of solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Sandnes, Bjoernar

    2003-07-01

    There are two main themes in this thesis. 1) Exergy efficient utilization of solar energy, where the introduction of alternative technologies such as photovoltaic/thermal collectors and phase change energy storage in a low temperature solar system is investigated. 2) The possibility of storing thermal energy in supercooled liquids is investigated. The introductory chapters introduce the concept of exergy, and focus on the use of solar heat as an inherently low quality source for covering low quality demands associated with space heating and hot water. The different stages of solar energy production, storage, and distribution of heat is discussed, with emphasis on exergy relevant issues. With the low temperature solar heating system as background, the introduction of some additional technologies that are investigated. A section of this thesis presents a study of a small scale PV/T collector as a possible component in a low temperature system. In another section the instrumentation that has been built for studies of full-size PV and thermal systems is described, and the possibility of using the PV unit outputs as parameters for controlling the thermal system operation is briefly discussed. It is suggested that the design of the PV/T unit in terms of whether priority should be given to electricity or heat production should be based on how consumption of high quality auxiliary energy is minimized, and not on adding up the combined exergy which is being produced. Solar combisystems require larger heat storage capacities compared to the more common solar hot water systems. Increased volumetric heat storage capacity can be achieved by latent heat storage systems where thermal energy is stored as heat of fusion in phase change materials (PCMs). A section presents a study where spherically encapsulated PCM is incorporated in a solar heat store. Solar combisystems are often complex, and have a relatively large number of interacting components. Another section describes a

  14. An efficient fringe integral equation method for optimizing the antenna location on complex bodies

    DEFF Research Database (Denmark)

    Jørgensen, Erik; Meincke, Peter; Breinbjerg, Olav

    2001-01-01

    in conventional integral equation solvers, a peaked current poses a challenging problem since it necessitates a large number of unknowns and excessive computation times. A fringe dual-surface magnetic field integral equation (F-DMFIE) that eliminates the problem of peaked currents and fields, even for impressed...... sources located arbitrarily close to the surface of the structure, was presented by Jorgensen, Meincke and Breinbjerg (see Proc. of the Applied Computational Electromagnetic Symp., Monterey, CA,. March 2001). In this formulation, the surface current on the structure is obtained by evaluating a number...

  15. EPPRD: An Efficient Privacy-Preserving Power Requirement and Distribution Aggregation Scheme for a Smart Grid

    National Research Council Canada - National Science Library

    Lei Zhang; Jing Zhang

    2017-01-01

    ...’ private information. Therefore, improving the individual power requirement and distribution efficiency to ensure communication reliability while preserving user privacy is a new challenge for SG...

  16. Innovation Steps towards Efficient Goods Distribution Systems for Urban Areas

    NARCIS (Netherlands)

    Van Binsbergen, A.J.; Visser, J.G.S.N.

    2001-01-01

    The distribution of goods for urban areas is vital to the prosperity of these areas. Nevertheless, there are various environmental and accessibility problems related to the urban goods distribution process. Only a comprehensive set of policy actions, that addresses the problems at different

  17. A chain-of-states acceleration method for the efficient location of minimum energy paths

    Energy Technology Data Exchange (ETDEWEB)

    Hernández, E. R., E-mail: Eduardo.Hernandez@csic.es; Herrero, C. P. [Instituto de Ciencia de Materiales de Madrid (ICMM–CSIC), Campus de Cantoblanco, 28049 Madrid (Spain); Soler, J. M. [Departamento de Física de la Materia Condensada and IFIMAC, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2015-11-14

    We describe a robust and efficient chain-of-states method for computing Minimum Energy Paths (MEPs) associated to barrier-crossing events in poly-atomic systems, which we call the acceleration method. The path is parametrized in terms of a continuous variable t ∈ [0, 1] that plays the role of time. In contrast to previous chain-of-states algorithms such as the nudged elastic band or string methods, where the positions of the states in the chain are taken as variational parameters in the search for the MEP, our strategy is to formulate the problem in terms of the second derivatives of the coordinates with respect to t, i.e., the state accelerations. We show this to result in a very simple and efficient method for determining the MEP. We describe the application of the method to a series of test cases, including two low-dimensional problems and the Stone-Wales transformation in C{sub 60}.

  18. Responses of European precipitation distributions and regimes to different blocking locations

    Science.gov (United States)

    Sousa, Pedro M.; Trigo, Ricardo M.; Barriopedro, David; Soares, Pedro M. M.; Ramos, Alexandre M.; Liberato, Margarida L. R.

    2017-02-01

    In this work we performed an analysis on the impacts of blocking episodes on seasonal and annual European precipitation and the associated physical mechanisms. Distinct domains were considered in detail taking into account different blocking center positions spanning between the Atlantic and western Russia. Significant positive precipitation anomalies are found for southernmost areas while generalized negative anomalies (up to 75 % in some areas) occur in large areas of central and northern Europe. This dipole of anomalies is reversed when compared to that observed during episodes of strong zonal flow conditions. We illustrate that the location of the maximum precipitation anomalies follows quite well the longitudinal positioning of the blocking centers and discuss regional and seasonal differences in the precipitation responses. To better understand the precipitation anomalies, we explore the blocking influence on cyclonic activity. The results indicate a split of the storm-tracks north and south of blocking systems, leading to an almost complete reduction of cyclonic centers in northern and central Europe and increases in southern areas, where cyclone frequency doubles during blocking episodes. However, the underlying processes conductive to the precipitation anomalies are distinct between northern and southern European regions, with a significant role of atmospheric instability in southern Europe, and moisture availability as the major driver at higher latitudes. This distinctive underlying process is coherent with the characteristic patterns of latent heat release from the ocean associated with blocked and strong zonal flow patterns. We also analyzed changes in the full range of the precipitation distribution of several regional sectors during blocked and zonal days. Results show that precipitation reductions in the areas under direct blocking influence are driven by a substantial drop in the frequency of moderate rainfall classes. Contrarily, southwards of

  19. Approaching hydrate and free gas distribution at the SUGAR-Site location in the Danube Delta

    Science.gov (United States)

    Bialas, Joerg; Dannowski, Anke; Zander, Timo; Klaeschen, Dirk; Klaucke, Ingo

    2017-04-01

    Gas hydrates did receive a lot of attention over the last decades when investigating their potential to serve as a possible source for Methane production. Among other world-wide programs the German SUGAR project sets out to investigate the entire chain from exploitation to production in Europe. Therefore research in the scope of the SUGAR project sets out to investigate a site in European EEZ for the detailed studies of hydrate and gas distribution in a permeable sediment matrix. Among others one aim of the project is to provide in situ samples of natural methane hydrate for further investigations by MEBO drilling. The Danube paleo-delta with its ancient canyon and levee systems was chosen as a possible candidate for hydrate formation within the available drilling range of 200 m below seafloor. In order to decide on the best drilling location cruise MSM34 (Bialas et al., 2014) of the German RV MARIA S MERIAN set out to acquire geophysical, geological and geochemical datasets for assessment of the hydrate content within the Danube paleo-delta, Black Sea. The Black Sea is well known for a significant gas content in the sedimentary column. Reports on observations of bottom simulating reflectors (BSR) by Popescu et al. (2007) and others indicate that free gas and hydrate occurrence can be expected within the ancient passive channel levee systems. A variety of inverted reflection events within the gas hydrate stability zone (GHSZ) were observed within the drilling range of MEBO and chosen for further investigation. Here we report on combined seismic investigations of high-resolution 2D & 3D multichannel seismic (MCS) acquisition accompanied by four component Ocean-Bottom-Seismometer (OBS) observations. P- and converted S-wave arrivals within the OBS datasets were analysed to provide overall velocity depth models. Due to the limited length of profiles the majority of OBS events are caused by near vertical reflections. While P-wave events have a significant lateral

  20. OPTSDNA: Performance evaluation of an efficient distributed bioinformatics system for DNA sequence analysis.

    Science.gov (United States)

    Khan, Mohammad Ibrahim; Sheel, Chotan

    2013-01-01

    Storage of sequence data is a big concern as the amount of data generated is exponential in nature at several locations. Therefore, there is a need to develop techniques to store data using compression algorithm. Here we describe optimal storage algorithm (OPTSDNA) for storing large amount of DNA sequences of varying length. This paper provides performance analysis of optimal storage algorithm (OPTSDNA) of a distributed bioinformatics computing system for analysis of DNA sequences. OPTSDNA algorithm is used for storing various sizes of DNA sequences into database. DNA sequences of different lengths were stored by using this algorithm. These input DNA sequences are varied in size from very small to very large. Storage size is calculated by this algorithm. Response time is also calculated in this work. The efficiency and performance of the algorithm is high (in size calculation with percentage) when compared with other known with sequential approach.

  1. Spatiotemporal distribution of location and object effects in reach-to-grasp kinematics

    Science.gov (United States)

    Rouse, Adam G.

    2015-01-01

    In reaching to grasp an object, the arm transports the hand to the intended location as the hand shapes to grasp the object. Prior studies that tracked arm endpoint and grip aperture have shown that reaching and grasping, while proceeding in parallel, are interdependent to some degree. Other studies of reaching and grasping that have examined the joint angles of all five digits as the hand shapes to grasp various objects have not tracked the joint angles of the arm as well. We, therefore, examined 22 joint angles from the shoulder to the five digits as monkeys reached, grasped, and manipulated in a task that dissociated location and object. We quantified the extent to which each angle varied depending on location, on object, and on their interaction, all as a function of time. Although joint angles varied depending on both location and object beginning early in the movement, an early phase of location effects in joint angles from the shoulder to the digits was followed by a later phase in which object effects predominated at all joint angles distal to the shoulder. Interaction effects were relatively small throughout the reach-to-grasp. Whereas reach trajectory was influenced substantially by the object, grasp shape was comparatively invariant to location. Our observations suggest that neural control of reach-to-grasp may occur largely in two sequential phases: the first determining the location to which the arm transports the hand, and the second shaping the entire upper extremity to grasp and manipulate the object. PMID:26445870

  2. Distribution of Barnacle Geese Branta leucopsis in relation to food resources, distance to roosts, and the location of refuges

    NARCIS (Netherlands)

    Si, Y.; Skidmore, A.K.; Wang, T.; De Boer, W.F.; Toxopeus, A.G.; Schlerf, M.; Oudshoorn, M.; Zwerver, S.; Van der Jeugd, H.P.; Exo, K-M.; Prins, H.H.T.

    2011-01-01

    We used GPS satellite tracking data and field measurements of vegetation to investigate the effect of food resources, distance to roosts, and the location of refuges on the distribution of Barnacle Geese Branta leucopsis in the northern part of The Netherlands. To deal with spatial dependence among

  3. Secure Computation, I/O-Efficient Algorithms and Distributed Signatures

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Kölker, Jonas; Toft, Tomas

    2012-01-01

    adversary corrupting a constant fraction of the players and servers. Using packed secret sharing, the data can be stored in a compact way but will only be accessible in a block-wise fashion. We explore the possibility of using I/O-efficient algorithms to nevertheless compute on the data as efficiently...... as if random access was possible. We show that for sorting, priority queues and data mining, this can indeed be done. We show actively secure protocols of complexity within a constant factor of the passively secure solution. As a technical contribution towards this goal, we develop techniques for generating...

  4. Accurate and efficient long-range lightning geo-location using a VLF radio atmospheric waveform bank

    Science.gov (United States)

    Said, Ryan Khalil

    2009-07-01

    On average there are ˜50 lightning flashes worldwide every second, with activity varying by region and season. Many systems currently exist that detect and locate lightning flashes for a broad range of commercial and scientific applications, including air traffic control, insurance claims, climate modeling, and the investigation of secondary atmospheric and magnetospheric electrical phenomena. These lightning detection systems have varying degrees of coverage area and location accuracy. Commercial ground-based systems that excel at locating return strokes in cloud-to-ground lightning use radio detection in the LF (30-300 kHz) band to provide very accurate location data, with a typical accuracy of ˜0.5 km, but they require a dense network of receivers separated by ˜400 km and are therefore primarily limited to monitoring the land areas within the network. In addition to radiating in the LF band, each lightning strike generates a broadband electromagnetic pulse containing frequencies from a few Hz through to the optical band with a peak component at VLF (3-30 kHz). Radio waves at VLF propagate through the waveguide formed by the Earth and the ionosphere with relatively low attenuation (˜3 dB per 1000 km), enabling the detection of these pulses, called radio atmospherics, at great distances from the lightning strike. Several existing networks utilize this efficient guiding to geo-locate lightning strikes often at distances greater than 5000 km from a given receiver. However, the Earth-ionosphere waveguide also presents a complex and time-varying channel that heavily disperses the pulse as it propagates away from the strike location. These networks fail to adequately address the path-dependence of the received impulse and suffer a lower location accuracy as a result (˜20 km). A new technique of long-range global lightning location is presented that both takes advantage of the efficient propagation at VLF and addresses the path-dependence of the propagation channel

  5. An Efficient Asymmetric Distributed Lock for Embedded Multiprocessor Systems

    NARCIS (Netherlands)

    Rutgers, J.H.; Bekooij, Marco Jan Gerrit; Smit, Gerardus Johannes Maria

    2012-01-01

    Efficient synchronization is a key concern in an embedded many-core system-on-chip (SoC). The use of atomic read-modify-write instructions combined with cache coherency as synchronization primitive is not always an option for shared-memory SoCs due to the lack of suitable IP. Furthermore, there are

  6. Optimization of Mass and Stiffness Distribution for Efficient Bipedal Walking

    NARCIS (Netherlands)

    Duindam, V.; Stramigioli, Stefano

    2005-01-01

    Energy-efficient control of bipedal walking robots requires both minimization of mechanical energy losses (often mainly due to impacts) and the use of natural oscillations in a mechanism to minimize actuator torques (as shown by research on passive dynamic walking). In this paper, we discuss how

  7. Efficient, Robust and Constant-Round Distributed RSA Key Generation

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Mikkelsen, Gert Læssøe

    2010-01-01

    We present the first protocol for distributed RSA key generation which is constant round, secure against malicious adversaries and has a negligibly small bound on the error probability, even using only one iteration of the underlying primality test on each candidate number.......We present the first protocol for distributed RSA key generation which is constant round, secure against malicious adversaries and has a negligibly small bound on the error probability, even using only one iteration of the underlying primality test on each candidate number....

  8. Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Shu Y.; Lee, Myungwoon; Wang, Tuo [Massachusetts Institute of Technology, Department of Chemistry (United States); Sergeyev, Ivan V. [Bruker Biospin (United States); Hong, Mei, E-mail: meihong@mit.edu [Massachusetts Institute of Technology, Department of Chemistry (United States)

    2016-03-15

    Although dynamic nuclear polarization (DNP) has dramatically enhanced solid-state NMR spectral sensitivities of many synthetic materials and some biological macromolecules, recent studies of membrane-protein DNP using exogenously doped paramagnetic radicals as polarizing agents have reported varied and sometimes surprisingly limited enhancement factors. This motivated us to carry out a systematic evaluation of sample preparation protocols for optimizing the sensitivity of DNP NMR spectra of membrane-bound peptides and proteins at cryogenic temperatures of ~110 K. We show that mixing the radical with the membrane by direct titration instead of centrifugation gives a significant boost to DNP enhancement. We quantify the relative sensitivity enhancement between AMUPol and TOTAPOL, two commonly used radicals, and between deuterated and protonated lipid membranes. AMUPol shows ~fourfold higher sensitivity enhancement than TOTAPOL, while deuterated lipid membrane does not give net higher sensitivity for the membrane peptides than protonated membrane. Overall, a ~100 fold enhancement between the microwave-on and microwave-off spectra can be achieved on lipid-rich membranes containing conformationally disordered peptides, and absolute sensitivity gains of 105–160 can be obtained between low-temperature DNP spectra and high-temperature non-DNP spectra. We also measured the paramagnetic relaxation enhancement of lipid signals by TOTAPOL and AMUPol, to determine the depths of these two radicals in the lipid bilayer. Our data indicate a bimodal distribution of both radicals, a surface-bound fraction and a membrane-bound fraction where the nitroxides lie at ~10 Å from the membrane surface. TOTAPOL appears to have a higher membrane-embedded fraction than AMUPol. These results should be useful for membrane-protein solid-state NMR studies under DNP conditions and provide insights into how biradicals interact with phospholipid membranes.

  9. Learning to merge search results for efficient Distributed Information Retrieval

    NARCIS (Netherlands)

    Tjin-Kam-Jet, Kien; Hiemstra, Djoerd

    2010-01-01

    Merging search results from different servers is a major problem in Distributed Information Retrieval. We used Regression-SVM and Ranking-SVM which would learn a function that merges results based on information that is readily available: i.e. the ranks, titles, summaries and URLs contained in the

  10. Smart Caching for Efficient Information Sharing in Distributed Information Systems

    Science.gov (United States)

    2008-09-01

    Leighton, Matthew Levine, Daniel Lewin , Rina Panigrahy (1997), “Consistent Hashing and Random Trees: Distributed Caching Protocols for Relieving Hot...Danzig, Chuck Neerdaels, Michael Schwartz and Kurt Worrell (1996), “A Hierarchical Internet Object Cache,” in USENIX Proceedings, 1996. 51 INITIAL

  11. Efficiently Computing Latency Distributions by combined Performance Evaluation Techniques

    NARCIS (Netherlands)

    van den Berg, Freek; Haverkort, Boudewijn R.H.M.; Hooman, Jozef; Knottenbelt, William; Wolter, Katinka; Busic, Ana; Gribaudo, Marco; Reinecke, Philipp

    2015-01-01

    Service-oriented systems are designed for interconnecting with other systems. The provided services face timing con- straints, the so-called latencies. We present a high-level per- formance evaluation technique that can be used by a system designer to obtain distributions of these latencies. This

  12. Chromosomal Location of Traits Associated with Wheat Seedling Water and Phosphorus Use Efficiency under Different Water and Phosphorus Stresses

    Directory of Open Access Journals (Sweden)

    Wei-Yi Song

    2009-09-01

    Full Text Available The objective of this study was to locate chromosomes for improving water and phosphorus-deficiency tolerance of wheat at the seedling stage. A set of Chinese Spring- Egyptian Red wheat substitution lines and their parent Chinese Spring (recipient and Egyptian Red (donor cultivars were measured to determine the chromosomal locations of genes controlling water use efficiency (WUE and phosphorus use efficiency (PUE under different water and phosphorus conditions. The results underlined that chromosomes 1A, 7A, 7B, and 3A showed higher leaf water use efficiency (WUEl = Pn/Tr; Pn = photosynthetic rate; Tr = transpiration rate under W-P (Hoagland solution with1/2P, -W-P (Hoagland solution with 1/2P and 10% PEG. Chromosomes 7A, 3D, 2B, 3B, and 4B may carry genes for positive effects on individual plant water use efficiency (WUEp = biomass/TWC; TWC = total water consumption under WP (Hoagland solution, W-P and -W-P treatment. Chromosomes 7A and 7D carry genes for PUE enhancement under WP, -WP (Hoagland solution with 10% PEG and W-P treatment. Chromosome 7A possibly has genes for controlling WUE and PUE simultaneously, which indicates that WUE and PUE may share the same genetic background. Phenotypic and genetic analysis of the investigated traits showed that photosynthetic rate (Pn and transpiration rate (Tr, Tr and WUEl showed significant positive and negative correlations under WP, W-P, -WP and -W-P, W-P, -WP treatments, respectively. Dry mass (DM, WUEP, PUT (phosphorus uptake all showed significant positive correlation under WP, W-P and -WP treatment. PUE and phosphorus uptake (PUT = P uptake per plant showed significant negative correlation under the four treatments. The results might provide useful information for improving WUE and PUE in wheat genetics.

  13. On intra-supply chain system with an improved distribution plan, multiple sales locations and quality assurance.

    Science.gov (United States)

    Chiu, Singa Wang; Huang, Chao-Chih; Chiang, Kuo-Wei; Wu, Mei-Fang

    2015-01-01

    Transnational companies, operating in extremely competitive global markets, always seek to lower different operating costs, such as inventory holding costs in their intra- supply chain system. This paper incorporates a cost reducing product distribution policy into an intra-supply chain system with multiple sales locations and quality assurance studied by [Chiu et al., Expert Syst Appl, 40:2669-2676, (2013)]. Under the proposed cost reducing distribution policy, an added initial delivery of end items is distributed to multiple sales locations to meet their demand during the production unit's uptime and rework time. After rework when the remaining production lot goes through quality assurance, n fixed quantity installments of finished items are then transported to sales locations at a fixed time interval. Mathematical modeling and optimization techniques are used to derive closed-form optimal operating policies for the proposed system. Furthermore, the study demonstrates significant savings in stock holding costs for both the production unit and sales locations. Alternative of outsourcing product delivery task to an external distributor is analyzed to assist managerial decision making in potential outsourcing issues in order to facilitate further reduction in operating costs.

  14. Energy Efficient Distributed Fault Identification Algorithm in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Meenakshi Panda

    2014-01-01

    Full Text Available A distributed fault identification algorithm is proposed here to find both hard and soft faulty sensor nodes present in wireless sensor networks. The algorithm is distributed, self-detectable, and can detect the most common byzantine faults such as stuck at zero, stuck at one, and random data. In the proposed approach, each sensor node gathered the observed data from the neighbors and computed the mean to check whether faulty sensor node is present or not. If a node found the presence of faulty sensor node, then compares observed data with the data of the neighbors and predict probable fault status. The final fault status is determined by diffusing the fault information from the neighbors. The accuracy and completeness of the algorithm are verified with the help of statistical model of the sensors data. The performance is evaluated in terms of detection accuracy, false alarm rate, detection latency and message complexity.

  15. The hemodynamic effects of the LVAD outflow cannula location on the thrombi distribution in the aorta: A primary numerical study.

    Science.gov (United States)

    Zhang, Yage; Gao, Bin; Yu, Chang

    2016-09-01

    Although a growing number of patients undergo LVAD implantation for heart failure treatment, thrombi are still the devastating complication for patients who used LVAD. LVAD outflow cannula location and thrombi generation sources were hypothesized to affect the thrombi distribution in the aorta. To test this hypothesis, numerical studies were conducted by using computational fluid dynamic (CFD) theory. Two anastomotic configurations, in which the LVAD outflow cannula is anastomosed to the anterior and lateral ascending aortic wall (named as anterior configurations and lateral configurations, respectively), are designed. The particles, whose sized are same as those of thrombi, are released at the LVAD output cannula and the aortic valve (named as thrombiP and thrombiL, respectively) to calculate the distribution of thrombi. The simulation results demonstrate that the thrombi distribution in the aorta is significantly affected by the LVAD outflow cannula location. In anterior configuration, the thrombi probability of entering into the three branches is 23.60%, while that in lateral configuration is 36.68%. Similarly, in anterior configuration, the thrombi probabilities of entering into brachiocephalic artery, left common carotid artery and left subclavian artery, is 8.51%, 9.64%, 5.45%, respectively, while that in lateral configuration it is 11.39%, 3.09%, 22.20% respectively. Moreover, the origins of thrombi could affect their distributions in the aorta. In anterior configuration, the thrombiP has a lower probability to enter into the three branches than thrombiL (12% vs. 25%). In contrast, in lateral configuration, the thrombiP has a higher probability to enter into the three branches than thrombiL (47% vs. 35%). In brief, the LVAD outflow cannula location significantly affects the distribution of thrombi in the aorta. Thus, in the clinical practice, the selection of outflow location of LVAD and the risk of thrombi formed in the left ventricle should be paid more

  16. Efficient Intra-household Allocations and Distribution Factors

    DEFF Research Database (Denmark)

    Browning, Martin; Bourguignon, François; Chiappori, Pierre-André

    and general test of the Pareto efficiency hypothesis, which is consistent with all possible assumptions on the private or public nature of goods, all possible consumption externalities between household members, and all types of interdependent individual preferences and domestic production technology......; moreover, the test is proved to be necessary and sufficient. We then provide a complete analysis of the identification problem; we show under which assumptions it is possible to identify, from the observation of the household consumption of private goods, the allocation of these goods within the household...... as well as the Engel curves of individual household members...

  17. Effects of cluster location and cluster distribution on performance on the traveling salesman problem.

    Science.gov (United States)

    MacGregor, James N

    2015-10-01

    Research on human performance in solving traveling salesman problems typically uses point sets as stimuli, and most models have proposed a processing stage at which stimulus dots are clustered. However, few empirical studies have investigated the effects of clustering on performance. In one recent study, researchers compared the effects of clustered, random, and regular stimuli, and concluded that clustering facilitates performance (Dry, Preiss, & Wagemans, 2012). Another study suggested that these results may have been influenced by the location rather than the degree of clustering (MacGregor, 2013). Two experiments are reported that mark an attempt to disentangle these factors. The first experiment tested several combinations of degree of clustering and cluster location, and revealed mixed evidence that clustering influences performance. In a second experiment, both factors were varied independently, showing that they interact. The results are discussed in terms of the importance of clustering effects, in particular, and perceptual factors, in general, during performance of the traveling salesman problem.

  18. Condensation of earthquake location distributions: Optimal spatial information encoding and application to multifractal analysis of south Californian seismicity.

    Science.gov (United States)

    Kamer, Yavor; Ouillon, Guy; Sornette, Didier; Wössner, Jochen

    2015-08-01

    We present the "condensation" method that exploits the heterogeneity of the probability distribution functions (PDFs) of event locations to improve the spatial information content of seismic catalogs. As its name indicates, the condensation method reduces the size of seismic catalogs while improving the access to the spatial information content of seismic catalogs. The PDFs of events are first ranked by decreasing location errors and then successively condensed onto better located and lower variance event PDFs. The obtained condensed catalog differs from the initial catalog by attributing different weights to each event, the set of weights providing an optimal spatial representation with respect to the spatially varying location capability of the seismic network. Synthetic tests on fractal distributions perturbed with realistic location errors show that condensation improves spatial information content of the original catalog, which is quantified by the likelihood gain per event. Applied to Southern California seismicity, the new condensed catalog highlights major mapped fault traces and reveals possible additional structures while reducing the catalog length by ∼25%. The condensation method allows us to account for location error information within a point based spatial analysis. We demonstrate this by comparing the multifractal properties of the condensed catalog locations with those of the original catalog. We evidence different spatial scaling regimes characterized by distinct multifractal spectra and separated by transition scales. We interpret the upper scale as to agree with the thickness of the brittle crust, while the lower scale (2.5 km) might depend on the relocation procedure. Accounting for these new results, the epidemic type aftershock model formulation suggests that, contrary to previous studies, large earthquakes dominate the earthquake triggering process. This implies that the limited capability of detecting small magnitude events cannot be used

  19. Lexical distributional cues, but not situational cues, are readily used to learn abstract locative verb-structure associations.

    Science.gov (United States)

    Twomey, Katherine E; Chang, Franklin; Ambridge, Ben

    2016-08-01

    Children must learn the structural biases of locative verbs in order to avoid making overgeneralisation errors (e.g., (∗)I filled water into the glass). It is thought that they use linguistic and situational information to learn verb classes that encode structural biases. In addition to situational cues, we examined whether children and adults could use the lexical distribution of nouns in the post-verbal noun phrase of transitive utterances to assign novel verbs to locative classes. In Experiment 1, children and adults used lexical distributional cues to assign verb classes, but were unable to use situational cues appropriately. In Experiment 2, adults generalised distributionally-learned classes to novel verb arguments, demonstrating that distributional information can cue abstract verb classes. Taken together, these studies show that human language learners can use a lexical distributional mechanism that is similar to that used by computational linguistic systems that use large unlabelled corpora to learn verb meaning. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Efficiently passing messages in distributed spiking neural network simulation.

    Science.gov (United States)

    Thibeault, Corey M; Minkovich, Kirill; O'Brien, Michael J; Harris, Frederick C; Srinivasa, Narayan

    2013-01-01

    Efficiently passing spiking messages in a neural model is an important aspect of high-performance simulation. As the scale of networks has increased so has the size of the computing systems required to simulate them. In addition, the information exchange of these resources has become more of an impediment to performance. In this paper we explore spike message passing using different mechanisms provided by the Message Passing Interface (MPI). A specific implementation, MVAPICH, designed for high-performance clusters with Infiniband hardware is employed. The focus is on providing information about these mechanisms for users of commodity high-performance spiking simulators. In addition, a novel hybrid method for spike exchange was implemented and benchmarked.

  1. Efficient Estimation of Smooth Distributions From Coarsely Grouped Data

    DEFF Research Database (Denmark)

    Rizzi, Silvia; Gampe, Jutta; Eilers, Paul H C

    2015-01-01

    Ungrouping binned data can be desirable for many reasons: Bins can be too coarse to allow for accurate analysis; comparisons can be hindered when different grouping approaches are used in different histograms; and the last interval is often wide and open-ended and, thus, covers a lot of information...... in the tail area. Age group-specific disease incidence rates and abridged life tables are examples of binned data. We propose a versatile method for ungrouping histograms that assumes that only the underlying distribution is smooth. Because of this modest assumption, the approach is suitable for most...... to the estimation of rates when both the event counts and the exposures to risk are grouped....

  2. Do as I say, not as I do:a lexical distributional account of English locative verb class acquisition

    OpenAIRE

    Twomey, Katherine; Chang, Franklin; Ambridge, Ben

    2014-01-01

    Children overgeneralise verbs to ungrammatical structures early in acquisition, but retreat from these overgeneralisations as they learn semantic verb classes. In a large corpus of English locative utterances (e.g., the woman sprayed water onto the wall/wall with water), we found structural biases which changed over development and which could explain overgeneralisation behaviour. Children and adults had similar verb classes and a correspondence analysis suggested that lexical distributional ...

  3. Measuring efficiency and productivity change (PTF) in the Peruvian electricity distribution companies after reforms

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Reyes, Raul [Organismo Supervisor de la Inversion en Energia y Mineria, Osinergmin (Peru); Tovar, Beatriz [Infrastructure and Transport Research Group (EIT), Department of Applied Economics, University of Palmas de Gran Canaria (Spain)

    2009-06-15

    This paper analyzes the evolution of productivity of the electricity distribution companies in Peru, to assess whether reforms have improved the efficiency in this sector. The paper also identifies potential sources of productivity changes, based on market restructuring the electricity sector and changes in property. To do this, we rely on a set of data for 14 distribution companies, for the period 1996-2006. Our analysis suggests that improvements in the efficiency and productivity of electricity distribution in Peru have occurred, and that there is a relationship between the restructuring of distribution sector and the enhancement of productivity. (author)

  4. Efficient distribution of toy products using ant colony optimization algorithm

    Science.gov (United States)

    Hidayat, S.; Nurpraja, C. A.

    2017-12-01

    CV Atham Toys (CVAT) produces wooden toys and furniture, comprises 13 small and medium industries. CVAT always attempt to deliver customer orders on time but delivery costs are high. This is because of inadequate infrastructure such that delivery routes are long, car maintenance costs are high, while fuel subsidy by the government is still temporary. This study seeks to minimize the cost of product distribution based on the shortest route using one of five Ant Colony Optimization (ACO) algorithms to solve the Vehicle Routing Problem (VRP). This study concludes that the best of the five is the Ant Colony System (ACS) algorithm. The best route in 1st week gave a total distance of 124.11 km at a cost of Rp 66,703.75. The 2nd week route gave a total distance of 132.27 km at a cost of Rp 71,095.13. The 3rd week best route gave a total distance of 122.70 km with a cost of Rp 65,951.25. While the 4th week gave a total distance of 132.27 km at a cost of Rp 74,083.63. Prior to this study there was no effort to calculate these figures.

  5. Efficient Extraction of High Centrality Vertices in Distributed Graphs

    Energy Technology Data Exchange (ETDEWEB)

    Kumbhare, Alok [Univ. of Southern California, Los Angeles, CA (United States); Frincu, Marc [Univ. of Southern California, Los Angeles, CA (United States); Raghavendra, Cauligi S. [Univ. of Southern California, Los Angeles, CA (United States); Prasanna, Viktor K. [Univ. of Southern California, Los Angeles, CA (United States)

    2014-09-09

    Betweenness centrality (BC) is an important measure for identifying high value or critical vertices in graphs, in variety of domains such as communication networks, road networks, and social graphs. However, calculating betweenness values is prohibitively expensive and, more often, domain experts are interested only in the vertices with the highest centrality values. In this paper, we first propose a partition-centric algorithm (MS-BC) to calculate BC for a large distributed graph that optimizes resource utilization and improves overall performance. Further, we extend the notion of approximate BC by pruning the graph and removing a subset of edges and vertices that contribute the least to the betweenness values of other vertices (MSL-BC), which further improves the runtime performance. We evaluate the proposed algorithms using a mix of real-world and synthetic graphs on an HPC cluster and analyze its strengths and weaknesses. The experimental results show an improvement in performance of upto 12x for large sparse graphs as compared to the state-of-the-art, and at the same time highlights the need for better partitioning methods to enable a balanced workload across partitions for unbalanced graphs such as small-world or power-law graphs.

  6. Locating distribution/service centers based on multi objective decision making using set covering and proximity to stock market

    Directory of Open Access Journals (Sweden)

    Mazyar Dabibi

    2016-09-01

    Full Text Available In the present competitive world, facility location is an important aspect of the supply chain (sc optimization. It involves selecting specific locations for facility construction and allocation of the distribution channel among different SC levels. In fact, it is a strategic issue which directly affects many operational/tactical decisions. Besides the accessibility, which results in customer satisfaction, the present paper optimizes the establishment costs of a number of distribution channels by considering their proximity to the stock market of the goods they distribute, and proposes mathematical models for two objective functions using the set covering problem. Then, two objective functions are proposed into one through the ε-constraint method and solved by the metaheuristic Genetic Algorithm (GA. To test the resulted model, a smaller scale problem is solved. Results from running the algorithm with different ε-values show that, on average, a 10% increase in ε, which increases the value of the second objective function - distance covered by customers will cause a 2% decrease in the value of the first objective function including the costs of establishing distribution centers. The repeatability and solution convergence of the two-objective model presented by the GA are other results obtained in this study.

  7. Development of Distributed System for Informational Location and Control on the Corporate Web Portal "Analytical Chemistry in Russia"

    Science.gov (United States)

    Shirokova, V. I.; Kolotov, V. P.; Alenina, M. V.

    A new Internet portal developed by community of Russian analysts has been launched in 2001 (http://www.geokhi.ru/~rusanalytchem, http://www.rusanalytchem.org) Corporate Web Portal information, "Analytical Chemistry in Russia" , Corporate Web Portal information, "Analytical Chemistry in Russia" ). Now the portal contains a large amount of information, great part of it is stored in the form of SQL data base (MS SQL). The information retrieval is made by means of ASP pages, containing VB Scripts. The obtained experience of work with such topical portal has detected some weak points, related with its centralized administration and updating. It has been found that urgent supporting of all requests from different persons/organizations on information allocation on the portal's server takes a lot of efforts and time. That is why, the further development of portal we relate with development of a distributed system for information allocation and control, under preserving of centralized administration for ensuring of security and stable working of the portal. Analysis and testing of some available technologies lead us to conclusion to apply MS Share Point technologies. A MS Share Point Team Services (SPTS) has been selected as a technology supporting relatively small groups, where MS SQL is used for storage data and metadata. The last feature was considered as decisive one for SPTS selection, allowing easy integration with data base of the whole portal. SPTS was launched as an independent Internet site accessible from home page of the portal. It serves as a root site to exit to dozens of subsites serving different bodies of Russian Scientific Council on analytical chemistry and external organizations located over the whole Russia. The secure functioning of such hierarchical system, which includes a lot of remote information suppliers, based on use of roles to manage user rights independently for each subsite. The root site is controlled by portal administrator, whereas the

  8. Spatial distribution of soil water repellency in a grassland located in Lithuania

    Science.gov (United States)

    Pereira, Paulo; Novara, Agata

    2014-05-01

    Soil water repellency (SWR) it is recognized to be very heterogeneous in time in space and depends on soil type, climate, land use, vegetation and season (Doerr et al., 2002). It prevents or reduces water infiltration, with important impacts on soil hydrology, influencing the mobilization and transport of substances into the soil profile. The reduced infiltration increases surface runoff and soil erosion. SWR reduce also the seed emergency and plant growth due the reduced amount of water in the root zone. Positive aspects of SWR are the increase of soil aggregate stability, organic carbon sequestration and reduction of water evaporation (Mataix-Solera and Doerr, 2004; Diehl, 2013). SWR depends on the soil aggregate size. In fire affected areas it was founded that SWR was more persistent in small size aggregates (Mataix-Solera and Doerr, 2004; Jordan et al., 2011). However, little information is available about SWR spatial distribution according to soil aggregate size. The aim of this work is study the spatial distribution of SWR in fine earth (Drop Penetration Method, which involves placing three drops of distilled water onto the soil surface and registering the time in seconds (s) required for the drop complete penetration (Wessel, 1988). Data did not respected Gaussian distribution, thus in order to meet normality requirements it was log-normal transformed. Spatial interpolations were carried out using Ordinary Kriging. The results shown that SWR was on average in fine earth 2.88 s (Coeficient of variation % (CV%)=44.62), 2-1mm 1.73 s (CV%=45.10), 1-0.5 mm 2.02 s (CV%=93.75), 0.5-0.25 mm 3.12 s (CV%=233.68) and in pattern was identified and the SWR was heterogeneously distributed. This suggests that the spatial distribution of SWR is very different according to the aggregate size. Future studies are needed in order to identify the causes and consequences of such dynamic. Acknowledgements The authors appreciated the support of the project "Litfire", Fire effects

  9. Efficient packet transportation on complex networks with nonuniform node capacity distribution

    Science.gov (United States)

    He, Xuan; Niu, Kai; He, Zhiqiang; Lin, Jiaru; Jiang, Zhong-Yuan

    2015-03-01

    Provided that node delivery capacity may be not uniformly distributed in many realistic networks, we present a node delivery capacity distribution in which each node capacity is composed of uniform fraction and degree related proportion. Based on the node delivery capacity distribution, we construct a novel routing mechanism called efficient weighted routing (EWR) strategy to enhance network traffic capacity and transportation efficiency. Compared with the shortest path routing and the efficient routing strategies, the EWR achieves the highest traffic capacity. After investigating average path length, network diameter, maximum efficient betweenness, average efficient betweenness, average travel time and average traffic load under extensive simulations, it indicates that the EWR appears to be a very effective routing method. The idea of this routing mechanism gives us a good insight into network science research. The practical use of this work is prospective in some real complex systems such as the Internet.

  10. Arsenic distribution in soils and rye plants of a cropland located in an abandoned mining area

    Energy Technology Data Exchange (ETDEWEB)

    Álvarez-Ayuso, Esther, E-mail: esther.alvarez@irnasa.csic.es [Department of Environmental Geochemistry, IRNASA (CSIC), C/ Cordel de Merinas 40-52, 37008 Salamanca (Spain); Abad-Valle, Patricia [Department of Environmental Geochemistry, IRNASA (CSIC), C/ Cordel de Merinas 40-52, 37008 Salamanca (Spain); Murciego, Ascensión [Department of Geology, Plza. de los Caídos s/n, Salamanca University, 37008 Salamanca (Spain); Villar-Alonso, Pedro [Saloro SLU, Avda. Italia 8, 37006 Salamanca (Spain)

    2016-01-15

    A mining impacted cropland was studied in order to assess its As pollution level and the derived environmental and health risks. Profile soil samples (0–50 cm) and rye plant samples were collected at different distances (0–150 m) from the near mine dump and analyzed for their As content and distribution. These cropland soils were sandy, acidic and poor in organic matter and Fe/Al oxides. The soil total As concentrations (38–177 mg kg{sup −1}) and, especially, the soil soluble As concentrations (0.48–4.1 mg kg{sup −1}) importantly exceeded their safe limits for agricultural use of soils. Moreover, the soil As contents more prone to be mobilized could rise up to 25–69% of total As levels as determined using (NH{sub 4}){sub 2}SO{sub 4}, NH{sub 4}H{sub 2}PO{sub 4} and (NH{sub 4}){sub 2}C{sub 2}O{sub 4}·H{sub 2}O as sequential extractants. Arsenic in rye plants was primarily distributed in roots (3.4–18.8 mg kg{sup −1}), with restricted translocation to shoots (TF = 0.05–0.26) and grains (TF = < 0.02–0.14). The mechanism for this excluder behavior should be likely related to arsenate reduction to arsenite in roots, followed by its complexation with thiols, as suggested by the high arsenite level in rye roots (up to 95% of the total As content) and the negative correlation between thiol concentrations in rye roots and As concentrations in rye shoots (| R | = 0.770; p < 0.01). Accordingly, in spite of the high mobile and mobilizable As contents in soils, As concentrations in rye above-ground tissues comply with the European regulation on undesirable substances in animal feed. Likewise, rye grain As concentrations were below its maximum tolerable concentration in cereals established by international legislation. - Highlights: • Environmental assessment of a rye cultivated area impacted by past mining activities. • Soil As contents exceeded the recommended safe limits for agricultural use of soils. • Soil soluble As concentrations attained high

  11. A mitochondrial location for haemoglobins—Dynamic distribution in ageing and Parkinson's disease☆

    Science.gov (United States)

    Shephard, Freya; Greville-Heygate, Oliver; Marsh, Oliver; Anderson, Susan; Chakrabarti, Lisa

    2014-01-01

    Haemoglobins are iron-containing proteins that transport oxygen in the blood of most vertebrates. The mitochondrion is the cellular organelle which consumes oxygen in order to synthesise ATP. Mitochondrial dysfunction is implicated in neurodegeneration and ageing. We find that α and β haemoglobin (Hba and Hbb) proteins are altered in their distribution in mitochondrial fractions from degenerating brain. We demonstrate that both Hba and Hbb are co-localised with the mitochondrion in mammalian brain. The precise localisation of the Hbs is within the inner membrane space and associated with inner mitochondrial membrane. Relative mitochondrial to cytoplasmic ratios of Hba and Hbb show changing distributions of these proteins during the process of neurodegeneration in the pcd5j mouse brain. A significant difference in mitochondrial Hba and Hbb content in the mitochondrial fraction is seen at 31 days after birth, this corresponds to a stage when dynamic neuronal loss is measured to be greatest in the Purkinje Cell Degeneration mouse. We also report changes in mitochondrial Hba and Hbb levels in ageing brain and muscle. Significant differences in mitochondrial Hba and Hbb can be seen when comparing aged brain to muscle, suggesting tissue specific functions of these proteins in the mitochondrion. In muscle there are significant differences between Hba levels in old and young mitochondria. To understand whether the changes detected in mitochondrial Hbs are of clinical significance, we examined Parkinson's disease brain, immunohistochemistry studies suggest that cell bodies in the substantia nigra accumulate mitochondrial Hb. However, western blotting of mitochondrial fractions from PD and control brains indicates significantly less Hb in PD brain mitochondria. One explanation could be a specific loss of cells containing mitochondria loaded with Hb proteins. Our study opens the door to an examination of the role of Hb function, within the context of the mitochondrion

  12. A Novel Power Efficient Location-Based Cooperative Routing with Transmission Power-Upper-Limit for Wireless Sensor Networks

    Science.gov (United States)

    Shi, Juanfei; Calveras, Anna; Cheng, Ye; Liu, Kai

    2013-01-01

    The extensive usage of wireless sensor networks (WSNs) has led to the development of many power- and energy-efficient routing protocols. Cooperative routing in WSNs can improve performance in these types of networks. In this paper we discuss the existing proposals and we propose a routing algorithm for wireless sensor networks called Power Efficient Location-based Cooperative Routing with Transmission Power-upper-limit (PELCR-TP). The algorithm is based on the principle of minimum link power and aims to take advantage of nodes cooperation to make the link work well in WSNs with a low transmission power. In the proposed scheme, with a determined transmission power upper limit, nodes find the most appropriate next nodes and single-relay nodes with the proposed algorithm. Moreover, this proposal subtly avoids non-working nodes, because we add a Bad nodes Avoidance Strategy (BAS). Simulation results show that the proposed algorithm with BAS can significantly improve the performance in reducing the overall link power, enhancing the transmission success rate and decreasing the retransmission rate. PMID:23676625

  13. Distribution of Age and Location of Chordoma in 39 Cases and Review of Treatment Options

    Directory of Open Access Journals (Sweden)

    Alireza Khoshnevisan

    2012-02-01

    Full Text Available Introduction:Skull base chordomas are rare neoplasms arising from the notochord.Although histologically benign, these tumors are locally aggressive and present significant management challenges. There are some studies on chordoma cases but there was no study about Iranian cases.In this study we evaluated the location, age and gender of the patients with Chordoma in two referral centers in Tehran. Methods: A database of patients with chordoma tumors referred to two centers (Shariati and Imam Hospitals, Tehran from 2001 to 2011 was retrospectively reviewed. Results: In our subjects tumors affect men nearly twice as frequently as women, and they are most commonly diagnosed in middle-aged (mean age was 50.6. Tumors typically occur in the axial skeleton and have a tendency for the spheno-occipital region of the skull base and sacral region. In adults 33.3% of chordomas involve the sacrococcygeal region, 53% occured at the base of the skull near the spheno-occipital area, and near 14% were found in the vertebral column. The cranial nerves mostly affected were abducens, oculomotor and trochlear, with some overlaps. All patients were treated with surgery and some cases referred for gamma-knife radiosurgery (GKS.Discussion:Findings of this study showed more involvement of males compare to females; that is different from other studies, however, few studies reported more male to female ratio. Despite the progress in current surgical techniques and some encouraging results with the use of targeted therapy, disease control and long-term prognosis of patients are still poor.

  14. Locating ethics in data science: responsibility and accountability in global and distributed knowledge production systems.

    Science.gov (United States)

    Leonelli, Sabina

    2016-12-28

    The distributed and global nature of data science creates challenges for evaluating the quality, import and potential impact of the data and knowledge claims being produced. This has significant consequences for the management and oversight of responsibilities and accountabilities in data science. In particular, it makes it difficult to determine who is responsible for what output, and how such responsibilities relate to each other; what 'participation' means and which accountabilities it involves, with regard to data ownership, donation and sharing as well as data analysis, re-use and authorship; and whether the trust placed on automated tools for data mining and interpretation is warranted (especially as data processing strategies and tools are often developed separately from the situations of data use where ethical concerns typically emerge). To address these challenges, this paper advocates a participative, reflexive management of data practices. Regulatory structures should encourage data scientists to examine the historical lineages and ethical implications of their work at regular intervals. They should also foster awareness of the multitude of skills and perspectives involved in data science, highlighting how each perspective is partial and in need of confrontation with others. This approach has the potential to improve not only the ethical oversight for data science initiatives, but also the quality and reliability of research outputs.This article is part of the themed issue 'The ethical impact of data science'. © 2015 The Authors.

  15. Dynamic Consensus Algorithm Based Distributed Global Efficiency Optimization of a Droop Controlled DC Microgrid

    DEFF Research Database (Denmark)

    Meng, Lexuan; Dragicevic, Tomislav; Guerrero, Josep M.

    2014-01-01

    In a DC microgrid, several paralleled conversion systems are installed in distributed substations for transferring power from external grid to a DC microgrid. Droop control is used for the distributed load sharing among all the DC/DC converters. Considering the typical efficiency feature of power...

  16. Screening for the Location of RNA using the Chloride Ion Distribution in Simulations of Virus Capsids.

    Science.gov (United States)

    Larsson, Daniel S D; van der Spoel, David

    2012-07-10

    The complete structure of the genomic material inside a virus capsid remains elusive, although a limited amount of symmetric nucleic acid can be resolved in the crystal structure of 17 icosahedral viruses. The negatively charged sugar-phosphate backbone of RNA and DNA as well as the large positive charge of the interior surface of the virus capsids suggest that electrostatic complementarity is an important factor in the packaging of the genomes in these viruses. To test how much packing information is encoded by the electrostatic and steric envelope of the capsid interior, we performed extensive all-atom molecular dynamics (MD) simulations of virus capsids with explicit water molecules and solvent ions. The model systems were two small plant viruses in which significant amounts of RNA has been observed by X-ray crystallography: satellite tobacco mosaic virus (STMV, 62% RNA visible) and satellite tobacco necrosis virus (STNV, 34% RNA visible). Simulations of half-capsids of these viruses with no RNA present revealed that the binding sites of RNA correlated well with regions populated by chloride ions, suggesting that it is possible to screen for the binding sites of nucleic acids by determining the equilibrium distribution of negative ions. By including the crystallographically resolved RNA in addition to ions, we predicted the localization of the unresolved RNA in the viruses. Both viruses showed a hot-spot for RNA binding at the 5-fold symmetry axis. The MD simulations were compared to predictions of the chloride density based on nonlinear Poisson-Boltzmann equation (PBE) calculations with mobile ions. Although the predictions are superficially similar, the PBE calculations overestimate the ion concentration close to the capsid surface and underestimate it far away, mainly because protein dynamics is not taken into account. Density maps from chloride screening can be used to aid in building atomic models of packaged virus genomes. Knowledge of the principles of

  17. A multi-objective possibilistic programming approach for locating distribution centers and allocating customers demands in supply chains

    Directory of Open Access Journals (Sweden)

    Seyed Ahmad Yazdian

    2011-01-01

    Full Text Available In this paper, we present a multi-objective possibilistic programming model to locate distribution centers (DCs and allocate customers' demands in a supply chain network design (SCND problem. The SCND problem deals with determining locations of facilities (DCs and/or plants, and also shipment quantities between each two consecutive tier of the supply chain. The primary objective of this study is to consider different risk factors which are involved in both locating DCs and shipping products as an objective function. The risk consists of various components: the risks related to each potential DC location, the risk associated with each arc connecting a plant to a DC and the risk of shipment from a DC to a customer. The proposed method of this paper considers the risk phenomenon in fuzzy forms to handle the uncertainties inherent in these factors. A possibilistic programming approach is proposed to solve the resulted multi-objective problem and a numerical example for three levels of possibility is conducted to analyze the model.

  18. Redundancy and Aging of Efficient Multidimensional MDS-Parity Protected Distributed Storage Systems

    OpenAIRE

    Arslan, Suayb S.

    2013-01-01

    The effect of redundancy on the aging of an efficient Maximum Distance Separable (MDS) parity--protected distributed storage system that consists of multidimensional arrays of storage units is explored. In light of the experimental evidences and survey data, this paper develops generalized expressions for the reliability of array storage systems based on more realistic time to failure distributions such as Weibull. For instance, a distributed disk array system is considered in which the array...

  19. What influences national and foreign physicians’ geographic distribution? An analysis of medical doctors’ residence location in Portugal

    Directory of Open Access Journals (Sweden)

    Russo Giuliano

    2012-07-01

    Full Text Available Abstract Background The debate over physicians’ geographical distribution has attracted the attention of the economic and public health literature over the last forty years. Nonetheless, it is still to date unclear what influences physicians’ location, and whether foreign physicians contribute to fill the geographical gaps left by national doctors in any given country. The present research sets out to investigate the current distribution of national and international physicians in Portugal, with the objective to understand its determinants and provide an evidence base for policy-makers to identify policies to influence it. Methods A cross-sectional study of physicians currently registered in Portugal was conducted to describe the population and explore the association of physician residence patterns with relevant personal and municipality characteristics. Data from the Portuguese Medical Council on physicians’ residence and characteristics were analysed, as well as data from the National Institute of Statistics on municipalities’ population, living standards and health care network. Descriptive statistics, chi-square tests, negative binomial and logistic regression modelling were applied to determine: (a municipality characteristics predicting Portuguese and International physicians’ geographical distribution, and; (b doctors’ characteristics that could increase the odds of residing outside the country’s metropolitan areas. Results There were 39,473 physicians in Portugal in 2008, 51.1% of whom male, and 40.2% between 41 and 55 years of age. They were predominantly Portuguese (90.5%, with Spanish, Brazilian and African nationalities also represented. Population, Population’s Purchasing Power, Nurses per capita and Municipality Development Index (MDI were the municipality characteristics displaying the strongest association with national physicians’ location. For foreign physicians, the MDI was not statistically significant

  20. Dip distribution of Oita-Kumamoto Tectonic Line located in central Kyushu, Japan, estimated by eigenvectors of gravity gradient tensor

    Science.gov (United States)

    Kusumoto, Shigekazu

    2016-09-01

    We estimated the dip distribution of Oita-Kumamoto Tectonic Line located in central Kyushu, Japan, by using the dip of the maximum eigenvector of the gravity gradient tensor. A series of earthquakes in Kumamoto and Oita beginning on 14 April 2016 occurred along this tectonic line, the largest of which was M = 7.3. Because a gravity gradiometry survey has not been conducted in the study area, we calculated the gravity gradient tensor from the Bouguer gravity anomaly and employed it to the analysis. The general dip distribution of the Oita-Kumamoto Tectonic Line was found to be about 65° and tends to be higher towards its eastern end. In addition, we estimated the dip around the largest earthquake to be about 60° from the gravity gradient tensor. This result agrees with the dip of the earthquake source fault obtained by Global Navigation Satellite System data analysis.[Figure not available: see fulltext.

  1. A LOCATION-INVENTORY MODEL INCLUDING DELIVERY DELAY COST AND CAPACITY CONSTRAINTS IN A STOCHASTIC DISTRIBUTION NETWORK

    Directory of Open Access Journals (Sweden)

    A. Ahmadi Javid

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: In this paper, we present a distribution network design problem in a supply chain system that minimises the total cost of location, inventory, and delivery delay. Customers’ demands are random, and multiple capacity levels are available for the distribution centers. The problem is first formulated as a mixed integer convex programming model to optimally solve medium-sized instances, and then a heuristic is developed for solving large-sized instances.

    AFRIKAANSE OPSOMMING: In hierdie artikel word ‘n distribusienetwerkprobleem in ‘n voorsieningsketting voorgehou waar die totale koste van die ligging, voorraad en afleweringsvertragings geminimiseer word. Die vraag is lukraak en verskeie kapasiteitsvlakke is beskikbaar in die verspreidingsentra. Die problem word eers geformuleer as ‘n gemengde-heeltal-konvekse model sodat mediumgrootte gevalle geoptimiseer kan word, waarna ‘n heuristieke benadering ontwikkel word vir die oplos van grootskaalse aktiwiteite.

  2. Assessing serum metabolite profiles as predictors for feed efficiency in broiler chickens reared at geographically distant locations.

    Science.gov (United States)

    Metzler-Zebeli, B U; Magowan, E; Hollmann, M; Ball, M E E; Molnár, A; Lawlor, P G; Hawken, R J; O'Connell, N E; Zebeli, Q

    2017-12-01

    1. The objective of this study was to investigate differences in growth performance, serum intermediary metabolites, acute-phase proteins and white blood cells in low, medium and high-residual feed intake (RFI) chickens. It was also assessed if the environment affects the feed efficiency (FE) and FE-related performance and serum profiles of chickens. 2. Individual body weight (BW) and feed intake (FI) were recorded from d 7 of life. At 5 weeks of age, female and male broiler chickens (Cobb 500) were selected according to their RFI (L1: Austria; L2: UK; n = 9/RFI group, sex and locatity -45on) and blood samples were collected. 3. Chickens at L1 had similar FI but a 15% higher BW gain compared to chickens at L2. The RFI values of female chickens were -231, 8 and 215 g and those of male chickens -197, 0 and 267 g for low, medium and high RFI, respectively. 4. Location affected serum glucose, urea, cholesterol, non-esterified fatty acids (NEFA) and ovotransferrin in females, and serum glucose and triglycerides in male chickens. Serum uric acid and NEFA linearly increased from low to high RFI in females, whereas in males, cholesterol showed the same linear response from low to high RFI. Serum alpha-1-acid glycoprotein and blood heterophil-to-lymphocyte ratio linearly increased by 35% and 68%, respectively, from low to high RFI but only in male chickens at L1. 5. Regression analysis showed significant positive relationships between RFI and serum uric acid (R2 = 0.49) and cholesterol (R2 = 0.13). 6. It was concluded that RFI-related variation in serum metabolites of chickens was largely similar for the two environments and that serum metabolite patterns could be used to predict RFI in chickens.

  3. An efficient algorithm for double-difference tomography and location in heterogeneous media, with an application to the Kilauea volcano

    Science.gov (United States)

    Monteiller, V.; Got, J.-L.; Virieux, J.; Okubo, P.

    2005-01-01

    Improving our understanding of crustal processes requires a better knowledge of the geometry and the position of geological bodies. In this study we have designed a method based upon double-difference relocation and tomography to image, as accurately as possible, a heterogeneous medium containing seismogenic objects. Our approach consisted not only of incorporating double difference in tomography but also partly in revisiting tomographic schemes for choosing accurate and stable numerical strategies, adapted to the use of cross-spectral time delays. We used a finite difference solution to the eikonal equation for travel time computation and a Tarantola-Valette approach for both the classical and double-difference three-dimensional tomographic inversion to find accurate earthquake locations and seismic velocity estimates. We estimated efficiently the square root of the inverse model's covariance matrix in the case of a Gaussian correlation function. It allows the use of correlation length and a priori model variance criteria to determine the optimal solution. Double-difference relocation of similar earthquakes is performed in the optimal velocity model, making absolute and relative locations less biased by the velocity model. Double-difference tomography is achieved by using high-accuracy time delay measurements. These algorithms have been applied to earthquake data recorded in the vicinity of Kilauea and Mauna Loa volcanoes for imaging the volcanic structures. Stable and detailed velocity models are obtained: the regional tomography unambiguously highlights the structure of the island of Hawaii and the double-difference tomography shows a detailed image of the southern Kilauea caldera-upper east rift zone magmatic complex. Copyright 2005 by the American Geophysical Union.

  4. Genus Distribution of Bacteria and Fungi Associated with Keratitis in a Large Eye Center Located in Southern China.

    Science.gov (United States)

    Lin, Lixia; Lan, Weizhong; Lou, Bingsheng; Ke, Hongmin; Yang, Yuanzhe; Lin, Xiaofeng; Liang, Lingyi

    2017-04-01

    To investigate the genus distribution of bacteria and fungi associated with keratitis in a large eye center located in Southern China and to compare the results with existing data from other areas in China. All results of corneal microbiological examinations from 2009 to 2013 of patients who had been clinically diagnosed with bacterial or fungal keratitis were obtained chronologically and anonymously from the microbiology database at Zhongshan Ophthalmic Center. Smear/culture data were reviewed and analyzed. Antibiotic resistance of the harvested bacteria was also evaluated. Of 2973 samples, the microbial detection rate was 46.05%; in which 759 eyes (25.5%) were positive for bacteria, 796 eyes (26.8%) were positive for fungi, and 186 eyes (6.3%) were co-infected with both fungi and bacteria. The most common type of bacteria isolated was Staphylococcus epidermidis (31.9%), followed by Pseudomonas aeruginosa (12.4%). The most common type of fungus was Fusarium species (29.3%), followed by Aspergillus species (24.1%). For the bacteria harvested, mean antibiotic resistance was chloromycetin (34.6%), cephalosporins (20.0%), fluoroquinolones (18.6%), and aminoglycosides (10.5%). The genus distribution of organisms detected in keratitis cases in the largest eye center located in Southern China differs from those in other areas in China. In Southern China during the time period studied, S. epidermidis and Fusarium sp. were the most common pathogens of infectious keratitis. Monitoring the changing trend of pathogens as well as antibiotic resistance are warranted.

  5. Levels and spatial distribution of airborne chemical elements in a heavy industrial area located in the north of Spain.

    Science.gov (United States)

    Lage, J; Almeida, S M; Reis, M A; Chaves, P C; Ribeiro, T; Garcia, S; Faria, J P; Fernández, B G; Wolterbeek, H T

    2014-01-01

    The adverse health effects of airborne particles have been subjected to intense investigation in recent years; however, more studies on the chemical characterization of particles from pollution emissions are needed to (1) identify emission sources, (2) better understand the relative toxicity of particles, and (3) pinpoint more targeted emission control strategies and regulations. The main objective of this study was to assess the levels and spatial distribution of airborne chemical elements in a heavy industrial area located in the north of Spain. Instrumental and biomonitoring techniques were integrated and analytical methods for k0 instrumental neutron activation analysis and particle-induced x-ray emission were used to determine element content in aerosol filters and lichens. Results indicated that in general local industry contributed to the emissions of As, Sb, Cu, V, and Ni, which are associated with combustion processes. In addition, the steelwork emitted significant quantities of Fe and Mn and the cement factory was associated with Ca emissions. The spatial distribution of Zn and Al also indicated an important contribution of two industries located outside the studied area.

  6. A multi-objective model for locating distribution centers in a supply chain network considering risk and inventory decisions

    Directory of Open Access Journals (Sweden)

    Sara Gharegozloo Hamedani

    2013-04-01

    Full Text Available This paper presents a multi-objective location problem in a three level supply chain network under uncertain environment considering inventory decisions. The proposed model of this paper considers uncertainty for different parameters including procurement, transportation costs, supply, demand and the capacity of various facilities. The proposed model presents a robust optimization model, which specifies locations of distribution centers to be opened, inventory control parameters (r, Q, and allocation of supply chain components, concurrently. The resulted mixed-integer nonlinear programming minimizes the expected total cost of such a supply chain network comprising location, procurement, transportation, holding, ordering, and shortage costs. The model also minimizes the variability of the total cost of relief chain and minimizes the financial risk or the probability of not meeting a certain budget. We use the ε-constraint method, which is a multi-objective technique with implicit trade-off information given, to solve the problem and using a couple of numerical instances, we examine the performance of the proposed approach.

  7. Stochastic frontier model approach for measuring stock market efficiency with different distributions.

    Directory of Open Access Journals (Sweden)

    Md Zobaer Hasan

    Full Text Available The stock market is considered essential for economic growth and expected to contribute to improved productivity. An efficient pricing mechanism of the stock market can be a driving force for channeling savings into profitable investments and thus facilitating optimal allocation of capital. This study investigated the technical efficiency of selected groups of companies of Bangladesh Stock Market that is the Dhaka Stock Exchange (DSE market, using the stochastic frontier production function approach. For this, the authors considered the Cobb-Douglas Stochastic frontier in which the technical inefficiency effects are defined by a model with two distributional assumptions. Truncated normal and half-normal distributions were used in the model and both time-variant and time-invariant inefficiency effects were estimated. The results reveal that technical efficiency decreased gradually over the reference period and that truncated normal distribution is preferable to half-normal distribution for technical inefficiency effects. The value of technical efficiency was high for the investment group and low for the bank group, as compared with other groups in the DSE market for both distributions in time-varying environment whereas it was high for the investment group but low for the ceramic group as compared with other groups in the DSE market for both distributions in time-invariant situation.

  8. Stochastic frontier model approach for measuring stock market efficiency with different distributions.

    Science.gov (United States)

    Hasan, Md Zobaer; Kamil, Anton Abdulbasah; Mustafa, Adli; Baten, Md Azizul

    2012-01-01

    The stock market is considered essential for economic growth and expected to contribute to improved productivity. An efficient pricing mechanism of the stock market can be a driving force for channeling savings into profitable investments and thus facilitating optimal allocation of capital. This study investigated the technical efficiency of selected groups of companies of Bangladesh Stock Market that is the Dhaka Stock Exchange (DSE) market, using the stochastic frontier production function approach. For this, the authors considered the Cobb-Douglas Stochastic frontier in which the technical inefficiency effects are defined by a model with two distributional assumptions. Truncated normal and half-normal distributions were used in the model and both time-variant and time-invariant inefficiency effects were estimated. The results reveal that technical efficiency decreased gradually over the reference period and that truncated normal distribution is preferable to half-normal distribution for technical inefficiency effects. The value of technical efficiency was high for the investment group and low for the bank group, as compared with other groups in the DSE market for both distributions in time-varying environment whereas it was high for the investment group but low for the ceramic group as compared with other groups in the DSE market for both distributions in time-invariant situation.

  9. Determine Neuronal Tuning Curves by Exploring Optimum Firing Rate Distribution for Information Efficiency

    Science.gov (United States)

    Han, Fang; Wang, Zhijie; Fan, Hong

    2017-01-01

    This paper proposed a new method to determine the neuronal tuning curves for maximum information efficiency by computing the optimum firing rate distribution. Firstly, we proposed a general definition for the information efficiency, which is relevant to mutual information and neuronal energy consumption. The energy consumption is composed of two parts: neuronal basic energy consumption and neuronal spike emission energy consumption. A parameter to model the relative importance of energy consumption is introduced in the definition of the information efficiency. Then, we designed a combination of exponential functions to describe the optimum firing rate distribution based on the analysis of the dependency of the mutual information and the energy consumption on the shape of the functions of the firing rate distributions. Furthermore, we developed a rapid algorithm to search the parameter values of the optimum firing rate distribution function. Finally, we found with the rapid algorithm that a combination of two different exponential functions with two free parameters can describe the optimum firing rate distribution accurately. We also found that if the energy consumption is relatively unimportant (important) compared to the mutual information or the neuronal basic energy consumption is relatively large (small), the curve of the optimum firing rate distribution will be relatively flat (steep), and the corresponding optimum tuning curve exhibits a form of sigmoid if the stimuli distribution is normal. PMID:28270760

  10. Determine Neuronal Tuning Curves by Exploring Optimum Firing Rate Distribution for Information Efficiency.

    Science.gov (United States)

    Han, Fang; Wang, Zhijie; Fan, Hong

    2017-01-01

    This paper proposed a new method to determine the neuronal tuning curves for maximum information efficiency by computing the optimum firing rate distribution. Firstly, we proposed a general definition for the information efficiency, which is relevant to mutual information and neuronal energy consumption. The energy consumption is composed of two parts: neuronal basic energy consumption and neuronal spike emission energy consumption. A parameter to model the relative importance of energy consumption is introduced in the definition of the information efficiency. Then, we designed a combination of exponential functions to describe the optimum firing rate distribution based on the analysis of the dependency of the mutual information and the energy consumption on the shape of the functions of the firing rate distributions. Furthermore, we developed a rapid algorithm to search the parameter values of the optimum firing rate distribution function. Finally, we found with the rapid algorithm that a combination of two different exponential functions with two free parameters can describe the optimum firing rate distribution accurately. We also found that if the energy consumption is relatively unimportant (important) compared to the mutual information or the neuronal basic energy consumption is relatively large (small), the curve of the optimum firing rate distribution will be relatively flat (steep), and the corresponding optimum tuning curve exhibits a form of sigmoid if the stimuli distribution is normal.

  11. Effect of particle size distribution on the separation efficiency in liquid chromatography.

    Science.gov (United States)

    Horváth, Krisztián; Lukács, Diána; Sepsey, Annamária; Felinger, Attila

    2014-09-26

    In this work, the influence of the width of particle size distribution (PSD) on chromatographic efficiency is studied. The PSD is described by lognormal distribution. A theoretical framework is developed in order to calculate heights equivalent to a theoretical plate in case of different PSDs. Our calculations demonstrate and verify that wide particle size distributions have significant effect on the separation efficiency of molecules. The differences of fully porous and core-shell phases regarding the influence of width of PSD are presented and discussed. The efficiencies of bimodal phases were also calculated. The results showed that these packings do not have any advantage over unimodal phases. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Does Weather Have an Impact on Electricity Distribution Efficiency? Evidence from South America

    OpenAIRE

    Anaya, K. L.; Pollitt, M.G.

    2014-01-01

    This paper analyses the influence of weather variables on the efficiency of electricity distribution utilities in Argentina, Brazil, Chile and Peru. The data covers 82 firms that operate in the previously mentioned countries which represent more than 90 per cent of the distribution market of energy delivered for the period 1998-2008. The stochastic frontier analysis (SFA) is applied with a translog input distance function approach. A combination of cost and cost-quality models is proposed to ...

  13. Optimal Location, Sizing, and Appropriate Technology Selection of Distributed Generators for Minimizing Power Loss Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    T. R. Ayodele

    2015-01-01

    Full Text Available Genetic algorithm (GA is utilized to select most suitable Distributed Generator (DG technology for optimal operation of power system as well as determine the optimal location and size of the DG to minimize power loss on the network. Three classes of DG technologies, synchronous generators, asynchronous generators, and induction generators, are considered and included as part of the variables for the optimization problem. IEEE 14-bus network is used to test the applicability of the algorithm. The result reveals that the developed algorithm is able to successfully select the most suitable DG technology and optimally size and place the DGs to minimize power loss in the network. Furthermore, optimum multiple placement of DG is considered to see the possible impact on power loss in the network. The result reveals that multiple placements can further reduce the power loss in the network.

  14. A Novel Method to Incorporate the Spatial Location of the Lung Dose Distribution into Predictive Radiation Pneumonitis Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradskiy, Yevgeniy, E-mail: yvinogra@mdanderson.org [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Tucker, Susan L. [Department of Bioinformatics and Computational Biology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Liao, Zhongxing [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Martel, Mary K. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

    2012-03-15

    Purpose: Studies have proposed that patients who receive radiation therapy to the base of the lung are more susceptible to radiation pneumonitis than patients who receive therapy to the apex of the lung. The primary purpose of the present study was to develop a novel method to incorporate the lung dose spatial information into a predictive radiation pneumonitis model. A secondary goal was to apply the method to a 547 lung cancer patient database to determine whether including the spatial information could improve the fit of our model. Methods and Materials: The three-dimensional dose distribution of each patient was mapped onto one common coordinate system. The boundaries of the coordinate system were defined by the extreme points of each individual patient lung. Once all dose distributions were mapped onto the common coordinate system, the spatial information was incorporated into a Lyman-Kutcher-Burman predictive radiation pneumonitis model. Specifically, the lung dose voxels were weighted using a user-defined spatial weighting matrix. We investigated spatial weighting matrices that linearly scaled each dose voxel according to the following orientations: superior-inferior, anterior-posterior, medial-lateral, left-right, and radial. The model parameters were fit to our patient cohort with the endpoint of severe radiation pneumonitis. The spatial dose model was compared against a conventional dose-volume model to determine whether adding a spatial component improved the fit of the model. Results: Of the 547 patients analyzed, 111 (20.3%) experienced severe radiation pneumonitis. Adding in a spatial parameter did not significantly increase the accuracy of the model for any of the weighting schemes. Conclusions: A novel method was developed to investigate the relationship between the location of the deposited lung dose and pneumonitis rate. The method was applied to a patient database, and we found that for our patient cohort, the spatial location does not influence

  15. A novel method to incorporate the spatial location of the lung dose distribution into predictive radiation pneumonitis modeling.

    Science.gov (United States)

    Vinogradskiy, Yevgeniy; Tucker, Susan L; Liao, Zhongxing; Martel, Mary K

    2012-03-15

    Studies have proposed that patients who receive radiation therapy to the base of the lung are more susceptible to radiation pneumonitis than patients who receive therapy to the apex of the lung. The primary purpose of the present study was to develop a novel method to incorporate the lung dose spatial information into a predictive radiation pneumonitis model. A secondary goal was to apply the method to a 547 lung cancer patient database to determine whether including the spatial information could improve the fit of our model. The three-dimensional dose distribution of each patient was mapped onto one common coordinate system. The boundaries of the coordinate system were defined by the extreme points of each individual patient lung. Once all dose distributions were mapped onto the common coordinate system, the spatial information was incorporated into a Lyman-Kutcher-Burman predictive radiation pneumonitis model. Specifically, the lung dose voxels were weighted using a user-defined spatial weighting matrix. We investigated spatial weighting matrices that linearly scaled each dose voxel according to the following orientations: superior-inferior, anterior-posterior, medial-lateral, left-right, and radial. The model parameters were fit to our patient cohort with the endpoint of severe radiation pneumonitis. The spatial dose model was compared against a conventional dose-volume model to determine whether adding a spatial component improved the fit of the model. Of the 547 patients analyzed, 111 (20.3%) experienced severe radiation pneumonitis. Adding in a spatial parameter did not significantly increase the accuracy of the model for any of the weighting schemes. A novel method was developed to investigate the relationship between the location of the deposited lung dose and pneumonitis rate. The method was applied to a patient database, and we found that for our patient cohort, the spatial location does not influence the risk of pneumonitis. Copyright © 2012 Elsevier

  16. Variation in size frequency distribution of coral populations under different fishing pressures in two contrasting locations in the Indian Ocean.

    Science.gov (United States)

    Grimsditch, G; Pisapia, C; Huck, M; Karisa, J; Obura, D; Sweet, M

    2017-10-01

    This study aimed to assess how the size-frequency distributions of coral genera varied between reefs under different fishing pressures in two contrasting Indian Ocean locations (the Maldives and East Africa). Using generalized linear mixed models, we were able to demonstrate that complex interactions occurred between coral genera, coral size class and fishing pressure. In both locations, we found Acropora coral species to be more abundant in non-fished compared to fished sites (a pattern which was consistent for nearly all the assessed size classes). Coral genera classified as 'stress tolerant' showed a contrasting pattern i.e. were higher in abundance in fished compared to non-fished sites. Site specific variations were also observed. For example, Maldivian reefs exhibited a significantly higher abundance in all size classes of 'competitive' corals compared to East Africa. This possibly indicates that East African reefs have already been subjected to higher levels of stress and are therefore less suitable environments for 'competitive' corals. This study also highlights the potential structure and composition of reefs under future degradation scenarios, for example with a loss of Acropora corals and an increase in dominance of 'stress tolerant' and 'generalist' coral genera. Copyright © 2017. Published by Elsevier Ltd.

  17. Combining Facility Location and Routing Decisions in Sustainable Urban Freight Distribution under Horizontal Collaboration: How Can Shippers Be Benefited?

    Directory of Open Access Journals (Sweden)

    Hanan Ouhader

    2017-01-01

    Full Text Available This article investigates the potential economic, environmental, and social effects of combining depot location and vehicle routing decisions in urban road freight transportation under horizontal collaboration. We consider a city in which several suppliers decide to joint deliveries to their customers and goods are delivered via intermediate depots. We study a transportation optimization problem from the perspective of sustainability development. This quantitative approach is based on three-objective mathematical model for strategic, tactical, and operational decision-making as a two-echelon location routing problem (2E-LRP. The objectives are to minimize cost and CO2 emissions of the transportation and maximize the created job opportunities. The model was solved with the ε-constraint method using extended known instances reflecting the real distribution in urban area to evaluate several goods’ delivery strategies. The obtained results by comparing collaborative and noncollaborative scenarios show that collaboration leads to a reduction in CO2 emissions, transportation cost, used vehicles, and travelled distances in addition to the improvement of the vehicles load rate but collaboration affects negatively social impact. To evaluate the effect of the method used to allocate the total gains to the different partners, we suggest to decision makers a comparison between well-known allocation methods.

  18. Pediatricians' practice location choice-Evaluating the effect of Japan's 2004 postgraduate training program on the spatial distribution of pediatricians.

    Science.gov (United States)

    Sakai, Rie; Fink, Günther; Kawachi, Ichiro

    2014-01-01

    To explore determinants of change in pediatrician supply in Japan, and examine impacts of a 2004 reform of postgraduate medical education on pediatricians' practice location choice. Data were compiled from secondary data sources. The dependent variable was the change in the number of pediatricians at the municipality ("secondary tier of medical care" [STM]) level. To analyze the determinants of pediatrician location choices, we considered the following predictors: initial ratio of pediatricians per 1000 children under five years of age (pediatrician density) and under-5 mortality as measures of local area need, as well as measures of residential quality. Ordinary least-squares regression models were used to estimate the associations. A coefficient equality test was performed to examine differences in predictors before and after 2004. Basic comparisons of pediatrician coverage in the top and bottom 10% of STMs were conducted to assess inequality in pediatrician supply. Increased supply was inversely associated with baseline pediatrician density both in the pre-period and post-period. Estimated impact of pediatrician density declined over time (P = 0.026), while opposite trends were observed for measures of residential quality. More specifically, urban centers and the SES composite index were positively associated with pediatrician supply for the post-period, but no such associations were found for the pre-period. Inequality in pediatrician distribution increased substantially after the reform, with the best-served 10% of communities benefitting from five times the pediatrician coverage compared to the least-served 10%. Residential quality increasingly became a function of location preference rather than public health needs after the reform. New placement schemes should be developed to achieve more equity in access to pediatric care.

  19. Combined use of thermal methods and seepage meters to efficiently locate, quantify, and monitor focused groundwater discharge to a sand-bed stream

    Science.gov (United States)

    Rosenberry, Donald O.; Briggs, Martin; Delin, Geoffrey N.; Hare, Danielle K.

    2016-01-01

    Quantifying flow of groundwater through streambeds often is difficult due to the complexity of aquifer-scale heterogeneity combined with local-scale hyporheic exchange. We used fiber-optic distributed temperature sensing (FO-DTS), seepage meters, and vertical temperature profiling to locate, quantify, and monitor areas of focused groundwater discharge in a geomorphically simple sand-bed stream. This combined approach allowed us to rapidly focus efforts at locations where prodigious amounts of groundwater discharged to the Quashnet River on Cape Cod, Massachusetts, northeastern USA. FO-DTS detected numerous anomalously cold reaches one to several m long that persisted over two summers. Seepage meters positioned upstream, within, and downstream of 7 anomalously cold reaches indicated that rapid groundwater discharge occurred precisely where the bed was cold; median upward seepage was nearly 5 times faster than seepage measured in streambed areas not identified as cold. Vertical temperature profilers deployed next to 8 seepage meters provided diurnal-signal-based seepage estimates that compared remarkably well with seepage-meter values. Regression slope and R2 values both were near 1 for seepage ranging from 0.05 to 3.0 m d−1. Temperature-based seepage model accuracy was improved with thermal diffusivity determined locally from diurnal signals. Similar calculations provided values for streambed sediment scour and deposition at subdaily resolution. Seepage was strongly heterogeneous even along a sand-bed river that flows over a relatively uniform sand and fine-gravel aquifer. FO-DTS was an efficient method for detecting areas of rapid groundwater discharge, even in a strongly gaining river, that can then be quantified over time with inexpensive streambed thermal methods.

  20. Does the Distribution of Efficiency Scores Depend on the Input Mix?

    DEFF Research Database (Denmark)

    Asmild, Mette; Leth Hougaard, Jens; Kronborg, Dorte

    In this paper we examine the possibility of using the standard Kruskal-Wallis rank test in order to evaluate whether the distribution of efficiency scores resulting from Data Envelopment Analysis (DEA) is independent of the input (or output) mix. Recently, a general data generating process (DGP...

  1. Efficiency Analyses of a DC Residential Power Distribution System for the Modern Home

    Directory of Open Access Journals (Sweden)

    GELANI, H. E.

    2015-02-01

    Full Text Available The electric power system started as DC back in the nineteenth century. However, the DC paradigm was soon ousted by AC due to inability of DC to change its voltage level. Now, after many years, with the development of power electronic converters capable of stepping-up and down DC voltage and converting it to-and-from AC, DC appears to be challenging AC and attempting a comeback. We now have DC power generation by solar cells, fuel cells and wind farms, DC power transmission in the form of HVDC (High Voltage DC transmission, DC power utilization by various modern electronic loads and DC power distribution that maybe regarded as still in research phase. This paper is an attempt to investigate feasibility of DC in the distribution portion of electrical power system. Specifically, the efficiency of a DC distribution system for residential localities is determined while keeping in view the concept of daily load variation. The aim is to bring out a more practical value of system efficiency as the efficiencies of DC/DC converters making up the system vary with load variation. This paper presents the modeling and simulation of a DC distribution system and efficiency results for various scenarios are presented.

  2. 10 CFR 431.197 - Manufacturer's determination of efficiency for distribution transformers.

    Science.gov (United States)

    2010-01-01

    ... basic model over a reasonable period of time (approximately 180 days), then it must test each unit... 10 Energy 3 2010-01-01 2010-01-01 false Manufacturer's determination of efficiency for distribution transformers. 431.197 Section 431.197 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY...

  3. Efficient identification of opportunities for Distributed Generation based on Smart Grid Technology

    DEFF Research Database (Denmark)

    Mutule, Anna; Obushevs, Artjoms; Lvov, Aleksandr

    2013-01-01

    The paper presents the main goals and achievements of the Smart Grids ERA-NET project named “Efficient identification of opportunities for Distributed Generation based on Smart Grid Technology (SmartGen)” during the second stage of project implementation. A description of Smart Grid Technology (SGT...

  4. A Study of Data Compression and Efficient Memory Utilization in Multiprocessor and Distributed Systems.

    Science.gov (United States)

    1980-08-31

    of data compression and efficient memory final 9/1/78 - 8/31/80 utilization in multiprocessor and distributed systems s. PERORMING ORG . REPORT MUME 7...only has to know the current module initiated. In Fig. ,the Gantt Chart for the operation of a 4-way interleaved memory with RR scheduling algorithm is

  5. Hybrid centralized-distributed power conditioning system for thermoelectric generator with high energy efficiency

    DEFF Research Database (Denmark)

    Wu, Hongfei; Sun, Kai; Chen, Min

    2013-01-01

    The unbalanced temperature distribution influences the power output of thermoelectric generator (TEG) system, which leads to mismatch power among TEG modules. This mismatch power degrades the energy efficiency of TEG systems based on the series-connected TEG modules. A hybrid centralized......-distributed (HCD) power conditioning system for TEG and its control strategy are proposed in this paper. The HCD power conditioning system is composed by a centralized power conversion stage and multiple distributed power conversion stages. Most of the power is processed by the centralized power conversion stage...... while only the mismatched power among the TEG modules is processed by the distributed power conversion stages. As a result, accurate distributed maximum power point tracking (MPPT) for each TEG module and single-stage power conversion between TEG modules and the load can be achieved by using...

  6. EPPRD: An Efficient Privacy-Preserving Power Requirement and Distribution Aggregation Scheme for a Smart Grid

    Science.gov (United States)

    Zhang, Lei; Zhang, Jing

    2017-01-01

    A Smart Grid (SG) facilitates bidirectional demand-response communication between individual users and power providers with high computation and communication performance but also brings about the risk of leaking users’ private information. Therefore, improving the individual power requirement and distribution efficiency to ensure communication reliability while preserving user privacy is a new challenge for SG. Based on this issue, we propose an efficient and privacy-preserving power requirement and distribution aggregation scheme (EPPRD) based on a hierarchical communication architecture. In the proposed scheme, an efficient encryption and authentication mechanism is proposed for better fit to each individual demand-response situation. Through extensive analysis and experiment, we demonstrate how the EPPRD resists various security threats and preserves user privacy while satisfying the individual requirement in a semi-honest model; it involves less communication overhead and computation time than the existing competing schemes. PMID:28783122

  7. Discriminatory Taxes are Unpopular Even when they are Efficient and Distributionally Fair

    DEFF Research Database (Denmark)

    Sausgruber, Rupert; Tyran, Jean-Robert Karl

    the same – but low – income to participants in all markets. The “discriminatory tax” (DT) imposes a higher burden on markets with inelastic demand and is therefore efficient but it is also unfair in that incomes are unequal across markets. We find that DT are unpopular, as predicted. Surprisingly, however......, DT remain unpopular when they are both efficient and produce a fair (equal) distribution. We conclude that non-discrimination (equal treatment) is a salient fairness principle in taxation that shapes voting on commodity taxes above and beyond concerns for efficiency and equal distribution......We explore the political acceptance of taxation in commodity markets. Participants in our experiment earn incomes by trading and must collectively choose one of two tax regimes to raise a given tax revenue. A “uniform tax” (UT) imposes the same tax rate on all markets and is fair in that it yields...

  8. Discriminatory taxes are unpopular—Even when they are efficient and distributionally fair

    DEFF Research Database (Denmark)

    Sausgruber, Rupert; Tyran, Jean-Robert Karl

    2014-01-01

    in that it yields the same – but low – income to participants in all markets. The “discriminatory tax” (DT) imposes a higher burden on markets with inelastic demand and is therefore efficient but it is also unfair in that incomes are unequal across markets. We find that DT is unpopular, as predicted. Surprisingly......, however, DT remains unpopular when they are both efficient and produce a fair (equal) distribution. We conclude that non-discrimination (equal treatment) is a salient fairness principle in taxation that shapes voting on commodity taxes above and beyond concerns for efficiency and equal distribution.......We explore the political acceptance of taxation in commodity markets. Participants in our experiment earn incomes by trading and must collectively choose one of the two tax regimes to raise a given tax revenue. A “uniform tax” (UT) imposes the same tax rate on all markets and is fair...

  9. EPPRD: An Efficient Privacy-Preserving Power Requirement and Distribution Aggregation Scheme for a Smart Grid.

    Science.gov (United States)

    Zhang, Lei; Zhang, Jing

    2017-08-07

    A Smart Grid (SG) facilitates bidirectional demand-response communication between individual users and power providers with high computation and communication performance but also brings about the risk of leaking users' private information. Therefore, improving the individual power requirement and distribution efficiency to ensure communication reliability while preserving user privacy is a new challenge for SG. Based on this issue, we propose an efficient and privacy-preserving power requirement and distribution aggregation scheme (EPPRD) based on a hierarchical communication architecture. In the proposed scheme, an efficient encryption and authentication mechanism is proposed for better fit to each individual demand-response situation. Through extensive analysis and experiment, we demonstrate how the EPPRD resists various security threats and preserves user privacy while satisfying the individual requirement in a semi-honest model; it involves less communication overhead and computation time than the existing competing schemes.

  10. An efficient algorithm for the single facility location problem with polyhedral norms and disk-shaped demand regions

    NARCIS (Netherlands)

    Berger, Andre; Grigoriev, Alexander; Winokurow, Andrej

    2017-01-01

    The single facility location problem with demand regions seeks for a facility location minimizing the sum of the distances from n demand regions to the facility. The demand regions represent sales markets where the transportation costs are negligible. In this paper, we assume that all demand regions

  11. Energy efficiency analysis: biomass-to-wheel efficiency related with biofuels production, fuel distribution, and powertrain systems.

    Directory of Open Access Journals (Sweden)

    Wei-Dong Huang

    Full Text Available BACKGROUND: Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV, and battery electric vehicles (BEV. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW analysis including three separate conversion elements--biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case--corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. SIGNIFICANCE: In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year, through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens.

  12. Energy Efficiency Analysis: Biomass-to-Wheel Efficiency Related with Biofuels Production, Fuel Distribution, and Powertrain Systems

    Science.gov (United States)

    Huang, Wei-Dong; Zhang, Y-H Percival

    2011-01-01

    Background Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE) vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV), and battery electric vehicles (BEV). Methodology/Principal Findings We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW) analysis including three separate conversion elements -- biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case – corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. Significance In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass) would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year), through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens. PMID:21765941

  13. Energy efficiency analysis: biomass-to-wheel efficiency related with biofuels production, fuel distribution, and powertrain systems.

    Science.gov (United States)

    Huang, Wei-Dong; Zhang, Y-H Percival

    2011-01-01

    Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE) vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV), and battery electric vehicles (BEV). We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW) analysis including three separate conversion elements--biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case--corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass) would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year), through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens.

  14. Atmospheric aerosols size distribution properties in winter and pre-monsoon over western Indian Thar Desert location

    Energy Technology Data Exchange (ETDEWEB)

    Panwar, Chhagan, E-mail: chhaganpanwar@gmail.com; Vyas, B. M. [Department of Physics, M.L. Sukhadia University, Udaipur-313001 (India)

    2016-05-06

    The first ever experimental results over Indian Thar Desert region concerning to height integrated aerosols size distribution function in particles size ranging between 0.09 to 2 µm such as, aerosols columnar size distribution (CSD), effective radius (R{sub eff}), integrated content of total aerosols (N{sub t}), columnar content of accumulation and coarse size aerosols particles concentration (N{sub a}) (size < 0.5 µm) and (N{sub c}) (size between 0.5 to 2 µm) have been described specifically during winter (a stable weather condition and intense anthropogenic pollution activity period) and pre-monsoon (intense dust storms of natural mineral aerosols as well as unstable atmospheric weather condition period) at Jaisalmer (26.90°N, 69.90°E, 220 m above surface level (asl)) located in central Thar desert vicinity of western Indian site. The CSD and various derived other aerosols size parameters are retrieved from their average spectral characteristics of Aerosol Optical Thickness (AOT) from UV to Infrared wavelength spectrum measured from Multi-Wavelength solar Radiometer (MWR). The natures of CSD are, in general, bio-modal character, instead of uniformly distributed character and power law distributions. The observed primary peaks in CSD plots are seen around about 10{sup 13} m{sup 2} μm{sup −1} at radius range 0.09-0.20 µm during both the seasons. But, in winter months, secondary peaks of relatively lower CSD values of 10{sup 10} to 10{sup 11} m{sup 2}/μm{sup −1} occur within a lower radius size range 0.4 to 0.6 µm. In contrast to this, while in dust dominated and hot season, the dominated secondary maxima of the higher CSD of about 10{sup 12} m{sup 2}μm{sup −3} is found of bigger aerosols size particles in a rage of 0.6 to 1.0 µm which is clearly demonstrating the characteristics of higher aerosols laden of bigger size aerosols in summer months relative to their prevailed lower aerosols loading of smaller size aerosols particles (0

  15. HAlign-II: efficient ultra-large multiple sequence alignment and phylogenetic tree reconstruction with distributed and parallel computing

    National Research Council Canada - National Science Library

    Shixiang Wan; Quan Zou

    2017-01-01

    .... files more than 1 GB) sequence analyses. Based on HAlign and Spark distributed computing system, we implement a highly cost-efficient and time-efficient HAlign-II tool to address ultra-large multiple biological sequence alignment...

  16. Efficient determination of distribution tariffs for the prevention of congestion from EV Charging

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Wu, Qiuwei; Østergaard, Jacob

    2012-01-01

    A dual objective electric vehicle (EV) charging schedule optimisation is proposed here whereby both consumer driving requirements and grid constraints are respected. A day-ahead dynamic tariff (DT) for distribution systems is proposed as a price signal to EV fleet operators (FO) bidding...... into the day-ahead market. The DT acts to disperse charging at congested periods and locations, thereby preventing congestion on a day-ahead basis. The magnitude of the DT is determined from a simulated locational marginal prices (LMPs), and the time extent of the DT is determined from analysis of the system...... loading curve prior to the application of the DT. Case studies were performed using a sample distribution network modelled on a network from the Danish island of Bornholm. A variety of price profiles were used to illustrate the efficacy of this approach. The case study results show that this approach...

  17. Effect of the Pore Size Distribution on the Displacement Efficiency of Multiphase Flow in Porous Media

    Directory of Open Access Journals (Sweden)

    Yang Yongfei

    2016-01-01

    Full Text Available Due to the complexity of porous media, it is difficult to use traditional experimental methods to study the quantitative impact of the pore size distribution on multiphase flow. In this paper, the impact of two pore distribution function types for three-phase flow was quantitatively investigated based on a three-dimensional pore-scale network model. The results show that in the process of wetting phase displacing the non-wetting phase without wetting films or spreading layers, the displacement efficiency was enhanced with the increase of the two function distribution’s parameters, which are the power law exponent in the power law distribution and the average pore radius or standard deviation in the truncated normal distribution, and vice versa. Additionally, the formation of wetting film is better for the process of displacement.

  18. THE USE OF NEW DISTRIBUTION CHANNELS TO INCREASE THE EFFICIENCY OF INSURANCE COMPANIES

    Directory of Open Access Journals (Sweden)

    Olga N. Kozlova

    2017-09-01

    Full Text Available The article deals with the issues of increasing the efficiency of insurance companies on the basis of using new non-traditional distribution channels. The relevance of the topic is justified by the automation of management processes, a new generation of consumers focused on new technologies, the use of the Internet, growing and selling functional mobile gadgets. The insurance companies use new distribution channels via the Internet network along with the traditional means for the expansion of the insurance portfolio and attracting active and passive consumers. The calculations carried out on the basis of the data of the Bank of Russia show that the share of such sales is growing, but not leading. The use of the Internet depends on many factors, but primarily on the types of insurance. The authors carry out calculations on the use of distribution channels in various types of insurance. The complexity and variety of products on life insurance requires qualified intermediaries, therefore, the use of new distribution channels here is not widespread in contrast to classical accident insurance or compulsory insurance, where sales are more efficient when organizing through the Internet. Selling through Internet has a number of advantages that reduce the cost of doing business, reduce the agency network, the cost of print advertising to attract passive and strengthen the relationship with active consumers. The authors also conduct analysis of the advantages and disadvantages of using mobile gadgets to work with potential customers, quantitative and qualitative benefits of implementing mobile apps in the work of insurance companies. The conclusions are made about the complexity of calculation of economic efficiency of implementing mobile applications. The possible directions of increasing the efficiency of using new distribution channels by insurance companies are defined.

  19. Sedimentation and trace metal distribution in selected locations of Sundarbans mangroves and Hooghly estuary, northeast coast of India.

    Science.gov (United States)

    Banerjee, Kakolee; Senthilkumar, B; Purvaja, R; Ramesh, R

    2012-02-01

    Four sediment cores were collected from selected locations of Sundarbans mangroves and Hooghly estuary, northeast coast of India to establish (210)Pb geochronology and trace metal distribution in sediments. Core sites were chosen to reflect a matrix of variable anthropogenic input and hydrological conditions. The vertical distribution of (210)Pb(xs) ((210)Pb(total)-(226)Ra) provided reliable geochronological age to calculate the mass accumulation rates and historic trace element inputs and their variations. The mass accumulation rates ranged from 0.41 g cm(-2) year(-1) (estuarine region) to 0.66 g cm(-2) year(-1) (mangrove region). Both in mangroves and estuarine systems, Fe-Mn oxy-hydroxides are observed to be a major controlling factor for trace metal accumulation when compared to organic carbon. Core collected from Hooghly estuary shows less contamination when compared to the mangrove region due to high energy and mostly coarse grained. Fe-normalized enrichment factors (EFs) of trace metals were calculated based on crustal trace element abundances. The EFs are typically >1 for Cd, Pb, Co, and Cu indicating that these metals are highly enriched while other metals such as Zn, Ni, Cr, and Mn show no enrichment or depletion. Both Sundarbans mangroves and Hooghly estuary have been receiving considerable pollution loads from anthropogenic sources such as industrial, domestic, and shipping activities in recent times, indicating high concentration of metals in the top few layers. This study suggests that the variation in trace metals content with depth or between mangrove and estuarine system results largely from metal input due to anthropogenic activities rather than diagenetic processes. © Springer Science+Business Media B.V. 2011

  20. Characteristic location and growth patterns of functioning pituitary adenomas: correlation with histological distribution of hormone-secreting cells in the pituitary gland.

    Science.gov (United States)

    Baik, Jun Seung; Lee, Mi Hyun; Ahn, Kook-Jin; Choi, Hyun Seok; Jung, So Lyung; Kim, Bum-Soo; Jeun, Sin Soo; Hong, Yong-Kil

    2015-01-01

    To evaluate the correlation between the magnetic resonance imaging findings of functional pituitary adenomas and histological distribution of hormone-secreting cells in pituitary gland. Forty-nine patients with pathologically confirmed functional micro and macro pituitary adenomas were retrospectively reviewed for its location and growth direction. Micro-prolactin, micro-adrenocorticotropic hormone (ACTH), and micro-growth hormone (GH) producing adenomas showed specific location (P-value adenomas showed specific growth direction (P-value adenomas did not. The functional pituitary microadenomas' location and macroadenomas' growth pattern correlate well with histological distribution of hormone-secreting cells in pituitary gland. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Opportunities for Efficiency Improvements in the U.S. Electricity Transmission and Distribution System

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Onar, Omer C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kirkham, Harold [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Emily [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Burkes, Klaehn [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Starke, Michael R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mohammed, Olama [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Weeks, George [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-04-01

    Since 2000, more than 172 quads of electricity have been transmitted on the US transmission and distribution (T&D) grid. Given this significant amount of energy flow, establishing and maintaining an efficient T&D grid is paramount. As shown in the figure below, the total percentage of overall losses in the US electric grid is approximately 6% (5.12% in 2012) (30% lower than the world average since 2000). While these efficiency losses appear to be relatively small from a percentage perspective, the total estimated electricity loss during this time is 10.8 quads.

  2. Skip-webs: Efficient distributed data structures for multi-dimensional data sets

    DEFF Research Database (Denmark)

    Arge, Lars; Eppstein, David; Goodrich, Michael T.

    2005-01-01

    We present a framework for designing efficient distributed data structures for multi-dimensional data. Our structures, which we call skip-webs, extend and improve previous randomized distributed data structures, including skipnets and skip graphs. Our framework applies to a general class of data......, and O(log n / log log n) messages for one-dimensional data. Finally, we show how to apply a blocking strategy to skip-webs to further improve message complexity for one-dimensional data when hosts can store more data....

  3. a Hadoop-Based Distributed Framework for Efficient Managing and Processing Big Remote Sensing Images

    Science.gov (United States)

    Wang, C.; Hu, F.; Hu, X.; Zhao, S.; Wen, W.; Yang, C.

    2015-07-01

    Various sensors from airborne and satellite platforms are producing large volumes of remote sensing images for mapping, environmental monitoring, disaster management, military intelligence, and others. However, it is challenging to efficiently storage, query and process such big data due to the data- and computing- intensive issues. In this paper, a Hadoop-based framework is proposed to manage and process the big remote sensing data in a distributed and parallel manner. Especially, remote sensing data can be directly fetched from other data platforms into the Hadoop Distributed File System (HDFS). The Orfeo toolbox, a ready-to-use tool for large image processing, is integrated into MapReduce to provide affluent image processing operations. With the integration of HDFS, Orfeo toolbox and MapReduce, these remote sensing images can be directly processed in parallel in a scalable computing environment. The experiment results show that the proposed framework can efficiently manage and process such big remote sensing data.

  4. An efficient numerical algorithm for computing densely distributed positive interior transmission eigenvalues

    Science.gov (United States)

    Li, Tiexiang; Huang, Tsung-Ming; Lin, Wen-Wei; Wang, Jenn-Nan

    2017-03-01

    We propose an efficient eigensolver for computing densely distributed spectra of the two-dimensional transmission eigenvalue problem (TEP), which is derived from Maxwell’s equations with Tellegen media and the transverse magnetic mode. The governing equations, when discretized by the standard piecewise linear finite element method, give rise to a large-scale quadratic eigenvalue problem (QEP). Our numerical simulation shows that half of the positive eigenvalues of the QEP are densely distributed in some interval near the origin. The quadratic Jacobi-Davidson method with a so-called non-equivalence deflation technique is proposed to compute the dense spectrum of the QEP. Extensive numerical simulations show that our proposed method processes the convergence efficiently, even when it needs to compute more than 5000 desired eigenpairs. Numerical results also illustrate that the computed eigenvalue curves can be approximated by nonlinear functions, which can be applied to estimate the denseness of the eigenvalues for the TEP.

  5. Distribution of structural funds: Equity, efficiency and public procurement (Czech Republic)

    OpenAIRE

    Hájek, Oldřich; Novosák, Jiří; Nekolová, Jana; Smékalová, Lenka

    2016-01-01

    This article deals with structural funds allocation for projects realized by Czech regional and local authorities in the programming period 2007-2013. Geographical distribution of structural funds in the context of the equity and efficiency goals is mapped. Two research questions are formulated in this regard. The first research question concerns the position of lagging regions in structural funds allocation. The second research question maps spatial spillovers of public procurement contracts...

  6. High Efficient Secret Key Distillation for Long Distance Continuous Variable Quantum Key Distribution

    OpenAIRE

    Zhao, Yi-bo; Han, Zheng-fu; Chen, Jin-jian; Gui, You-zhen; Guo, Guang-can

    2006-01-01

    The continuous variable quantum key distribution is expected to provide high secret key rate without single photon source and detector, but the lack of the secure and effective key distillation method makes it unpractical. Here, we present a secure single-bit-reverse-reconciliation protocol combined with secret information concentration and post-selection, which can distill the secret key with high efficiency and low computational complexity. The simulation results show that this protocol can...

  7. Distributed Energy-Efficient Topology Control Algorithm in Home M2M Networks

    OpenAIRE

    Chao-Yang Lee; Chu-Sing Yang

    2012-01-01

    Because machine-to-machine (M2M) technology enables machines to communicate with each other without human intervention, it could play a big role in sensor network systems. Through wireless sensor network (WSN) gateways, various information can be collected by sensors for M2M systems. For home M2M networks, this study proposes a distributed energy-efficient topology control algorithm for both topology construction and topology maintenance. Topology control is an effective method of enhancing e...

  8. Distributed Particle Swarm Optimization and Simulated Annealing for Energy-efficient Coverage in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dao-Wei Bi

    2007-05-01

    Full Text Available The limited energy supply of wireless sensor networks poses a great challenge for the deployment of wireless sensor nodes. In this paper, we focus on energy-efficient coverage with distributed particle swarm optimization and simulated annealing. First, the energy-efficient coverage problem is formulated with sensing coverage and energy consumption models. We consider the network composed of stationary and mobile nodes. Second, coverage and energy metrics are presented to evaluate the coverage rate and energy consumption of a wireless sensor network, where a grid exclusion algorithm extracts the coverage state and Dijkstra’s algorithm calculates the lowest cost path for communication. Then, a hybrid algorithm optimizes the energy consumption, in which particle swarm optimization and simulated annealing are combined to find the optimal deployment solution in a distributed manner. Simulated annealing is performed on multiple wireless sensor nodes, results of which are employed to correct the local and global best solution of particle swarm optimization. Simulations of wireless sensor node deployment verify that coverage performance can be guaranteed, energy consumption of communication is conserved after deployment optimization and the optimization performance is boosted by the distributed algorithm. Moreover, it is demonstrated that energy efficiency of wireless sensor networks is enhanced by the proposed optimization algorithm in target tracking applications.

  9. Fuzzy-Logic Based Distributed Energy-Efficient Clustering Algorithm for Wireless Sensor Networks

    Science.gov (United States)

    Zhang, Ying; Wang, Jun; Han, Dezhi; Wu, Huafeng; Zhou, Rundong

    2017-01-01

    Due to the high-energy efficiency and scalability, the clustering routing algorithm has been widely used in wireless sensor networks (WSNs). In order to gather information more efficiently, each sensor node transmits data to its Cluster Head (CH) to which it belongs, by multi-hop communication. However, the multi-hop communication in the cluster brings the problem of excessive energy consumption of the relay nodes which are closer to the CH. These nodes’ energy will be consumed more quickly than the farther nodes, which brings the negative influence on load balance for the whole networks. Therefore, we propose an energy-efficient distributed clustering algorithm based on fuzzy approach with non-uniform distribution (EEDCF). During CHs’ election, we take nodes’ energies, nodes’ degree and neighbor nodes’ residual energies into consideration as the input parameters. In addition, we take advantage of Takagi, Sugeno and Kang (TSK) fuzzy model instead of traditional method as our inference system to guarantee the quantitative analysis more reasonable. In our scheme, each sensor node calculates the probability of being as CH with the help of fuzzy inference system in a distributed way. The experimental results indicate EEDCF algorithm is better than some current representative methods in aspects of data transmission, energy consumption and lifetime of networks. PMID:28671641

  10. A traction control strategy with an efficiency model in a distributed driving electric vehicle.

    Science.gov (United States)

    Lin, Cheng; Cheng, Xingqun

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention.

  11. Efficient LIDAR Point Cloud Data Managing and Processing in a Hadoop-Based Distributed Framework

    Science.gov (United States)

    Wang, C.; Hu, F.; Sha, D.; Han, X.

    2017-10-01

    Light Detection and Ranging (LiDAR) is one of the most promising technologies in surveying and mapping city management, forestry, object recognition, computer vision engineer and others. However, it is challenging to efficiently storage, query and analyze the high-resolution 3D LiDAR data due to its volume and complexity. In order to improve the productivity of Lidar data processing, this study proposes a Hadoop-based framework to efficiently manage and process LiDAR data in a distributed and parallel manner, which takes advantage of Hadoop's storage and computing ability. At the same time, the Point Cloud Library (PCL), an open-source project for 2D/3D image and point cloud processing, is integrated with HDFS and MapReduce to conduct the Lidar data analysis algorithms provided by PCL in a parallel fashion. The experiment results show that the proposed framework can efficiently manage and process big LiDAR data.

  12. A Traction Control Strategy with an Efficiency Model in a Distributed Driving Electric Vehicle

    Science.gov (United States)

    Lin, Cheng

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention. PMID:25197697

  13. IMPACTS OF REFRIGERANTLINE LENGTH ON SYSTEM EFFICIENCY IN RESIDENTIAL HEATING AND COOLING SYSTEMS USING REFRIGERANT DISTRIBUTION.

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS, J.W.

    2001-04-01

    The effects on system efficiency of excess refrigerant line length are calculated for an idealized residential heating and cooling system. By excess line length is meant refrigerant tubing in excess of the 25 R provided for in standard equipment efficiency test methods. The purpose of the calculation is to provide input for a proposed method for evaluating refrigerant distribution system efficiency. A refrigerant distribution system uses refrigerant (instead of ducts or pipes) to carry heat and/or cooling effect from the equipment to the spaces in the building in which it is used. Such systems would include so-called mini-splits as well as more conventional split systems that for one reason or another have the indoor and outdoor coils separated by more than 25 ft. This report performs first-order calculations of the effects on system efficiency, in both the heating and cooling modes, of pressure drops within the refrigerant lines and of heat transfer between the refrigerant lines and the space surrounding them.

  14. Physical evidence that the variations in the efficiency of homologous series of antioxidants in emulsions are a result of differences in their distribution.

    Science.gov (United States)

    Costa, Marlene; Losada-Barreiro, Sonia; Paiva-Martins, Fátima; Bravo-Díaz, Carlos

    2017-01-01

    The relationships between the hydrophilic-lipophilic balance (HLB) of antioxidants (AOs) and their distributions and efficiencies in emulsions are not fully understood. Recent reports indicate that, for series of homologous antioxidants of different hydrophobicity, the variation of their efficiency with the HLB of the AO increases with the alkyl chain length up to a maximum (C3 -C8 ester) followed by a decrease (cut-off effect). We determined the distributions of a series of caffeic acid derivatives in intact soybean emulsions by employing a specifically designed chemical probe located in the interfacial region of the emulsion. We also determined the AO efficiencies in the very same emulsions. We demonstrate that the variation of the percentage of AO in the interfacial region of soybean oil-in-water emulsions with the AO HLB parallels that of their antioxidant efficiency. The results provide physical evidence that the variations in the efficiency of homologous series of antioxidants in emulsions are the result of differences in their distribution. The results confirm that, with other things being equal, there is a direct relationship between the percentage of AO in the interfacial region of the emulsions and their efficiency, providing a natural explanation, based on molecular properties, of the cut-off effect. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. Efficient calculation of local dose distributions for response modeling in proton and heavier ion beams

    DEFF Research Database (Denmark)

    Greilich, Steffen; Hahn, Ute; Kiderlen, Markus

    2014-01-01

    We present an algorithm for fast and accurate computation of the local dose distribution in MeV beams of protons, carbon ions or other heavy charged particles. It uses compound Poisson modeling of track interaction and successive convolutions for fast computation. It can handle arbitrary complex ...... mixed particle fields over a wide range of fluences. Since the local dose distribution is the essential part of several approaches to model detector efficiency and cellular response it has potential use in ion-beam dosimetry, radiotherapy, and radiobiology.......We present an algorithm for fast and accurate computation of the local dose distribution in MeV beams of protons, carbon ions or other heavy charged particles. It uses compound Poisson modeling of track interaction and successive convolutions for fast computation. It can handle arbitrary complex...

  16. The prevalence and distribution of gastrointestinal parasites of stray and refuge dogs in four locations in India.

    Science.gov (United States)

    Traub, Rebecca J; Pednekar, Riddhi P; Cuttell, Leigh; Porter, Ronald B; Abd Megat Rani, Puteri Azaziah; Gatne, Mukulesh L

    2014-09-15

    A gastrointestinal parasite survey of 411 stray and refuge dogs sampled from four geographical and climactically distinct locations in India revealed these animals to represent a significant source of environmental contamination for parasites that pose a zoonotic risk to the public. Hookworms were the most commonly identified parasite in dogs in Sikkim (71.3%), Mumbai (48.8%) and Delhi (39.1%). In Ladakh, which experiences harsh extremes in climate, a competitive advantage was observed for parasites such as Sarcocystis spp. (44.2%), Taenia hydatigena (30.3%) and Echinococcus granulosus (2.3%) that utilise intermediate hosts for the completion of their life cycle. PCR identified Ancylostoma ceylanicum and Ancylostoma caninum to occur sympatrically, either as single or mixed infections in Sikkim (Northeast) and Mumbai (West). In Delhi, A. caninum was the only species identified in dogs, probably owing to its ability to evade unfavourable climatic conditions by undergoing arrested development in host tissue. The expansion of the known distribution of A. ceylanicum to the west, as far as Mumbai, justifies the renewed interest in this emerging zoonosis and advocates for its surveillance in future human parasite surveys. Of interest was the absence of Trichuris vulpis in dogs, in support of previous canine surveys in India. This study advocates the continuation of birth control programmes in stray dogs that will undoubtedly have spill-over effects on reducing the levels of environmental contamination with parasite stages. In particular, owners of pet animals exposed to these environments must be extra vigilant in ensuring their animals are regularly dewormed and maintaining strict standards of household and personal hygiene. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Distribution of sexually transmitted diseases and risk factors by work locations among female sex workers in Tijuana, Mexico.

    Science.gov (United States)

    Rusch, Melanie L A; Brouwer, Kimberly C; Lozada, Remedios; Strathdee, Steffanie A; Magis-Rodríguez, Carlos; Patterson, Thomas L

    2010-10-01

    Sex work is regulated in the Zona Roja (red light district) in Tijuana, Mexico, where HIV and sexually transmitted disease (STD) prevalence is high among female sex workers (FSWs). We examined the spatial distribution of STDs by work venue among FSWs in Tijuana. FSWs aged 18 years and older who reported unprotected sex with ≥ 1 client in the past 2 months underwent testing for HIV, syphilis, gonorrhea, and Chlamydia. HIV/STDs were mapped by venue (i.e., bar, hotel) and Getis-Ord Gi statistics were used to identify geographic hotspots. High-risk venues were then identified using a standardized STD ratio (high risk defined as a ratio ≥ 1.25). Logistic regression was used to assess correlates of working at a high risk venue. Of 474 FSWs, 176 (36.4%) had at least 1 bacterial sexually transmitted infection (STI); 36 (7.6%) were HIV-positive. Within the Zona Roja, 1 venue was identified as a geographic "hotspot," with a higher than expected number of HIV/STD-positive FSW (P < 0.05) as compared to neighboring venues. Using the STD ratio definition, 11 venues were identified as high-risk; FSWs working in these locations had higher education, were more likely to report always using drugs with sex, and having mostly US clients. They were less likely to be registered FSWs or to live at their work venue. A relatively few number of sex work venues accounted for a large proportion of the HIV/STI burden among FSWs in Tijuana. Structural interventions that focus on sex work venues could help increase STI diagnosis, prevention, and treatment among FSWs in Tijuana.

  18. Efficient and universal quantum key distribution based on chaos and middleware

    Science.gov (United States)

    Jiang, Dong; Chen, Yuanyuan; Gu, Xuemei; Xie, Ling; Chen, Lijun

    2017-01-01

    Quantum key distribution (QKD) promises unconditionally secure communications, however, the low bit rate of QKD cannot meet the requirements of high-speed applications. Despite the many solutions that have been proposed in recent years, they are neither efficient to generate the secret keys nor compatible with other QKD systems. This paper, based on chaotic cryptography and middleware technology, proposes an efficient and universal QKD protocol that can be directly deployed on top of any existing QKD system without modifying the underlying QKD protocol and optical platform. It initially takes the bit string generated by the QKD system as input, periodically updates the chaotic system, and efficiently outputs the bit sequences. Theoretical analysis and simulation results demonstrate that our protocol can efficiently increase the bit rate of the QKD system as well as securely generate bit sequences with perfect statistical properties. Compared with the existing methods, our protocol is more efficient and universal, it can be rapidly deployed on the QKD system to increase the bit rate when the QKD system becomes the bottleneck of its communication system.

  19. Offloading Method for Efficient Use of Local Computational Resources in Mobile Location-Based Services Using Clouds

    Directory of Open Access Journals (Sweden)

    Yunsik Son

    2017-01-01

    Full Text Available With the development of mobile computing, location-based services (LBSs have been developed to provide services based on location information through communication networks or the global positioning system. In recent years, LBSs have evolved into smart LBSs, which provide many services using only location information. These include basic services such as traffic, logistic, and entertainment services. However, a smart LBS may require relatively complicated operations, which may not be effectively performed by the mobile computing system. To overcome this problem, a computation offloading technique can be used to perform certain tasks on mobile devices in cloud and fog environments. Furthermore, mobile platforms exist that provide smart LBSs. The smart cross-platform is a solution based on a virtual machine (VM that enables compatibility of content in various mobile and smart device environments. However, owing to the nature of the VM-based execution method, the execution performance is degraded compared to that of the native execution method. In this paper, we introduce a computation offloading technique that utilizes fog computing to improve the performance of VMs running on mobile devices. We applied the proposed method to smart devices with a smart VM (SVM and HTML5 SVM to compare their performances.

  20. An efficient biological pathway layout algorithm combining grid-layout and spring embedder for complicated cellular location information.

    Science.gov (United States)

    Kojima, Kaname; Nagasaki, Masao; Miyano, Satoru

    2010-06-18

    Graph drawing is one of the important techniques for understanding biological regulations in a cell or among cells at the pathway level. Among many available layout algorithms, the spring embedder algorithm is widely used not only for pathway drawing but also for circuit placement and www visualization and so on because of the harmonized appearance of its results. For pathway drawing, location information is essential for its comprehension. However, complex shapes need to be taken into account when torus-shaped location information such as nuclear inner membrane, nuclear outer membrane, and plasma membrane is considered. Unfortunately, the spring embedder algorithm cannot easily handle such information. In addition, crossings between edges and nodes are usually not considered explicitly. We proposed a new grid-layout algorithm based on the spring embedder algorithm that can handle location information and provide layouts with harmonized appearance. In grid-layout algorithms, the mapping of nodes to grid points that minimizes a cost function is searched. By imposing positional constraints on grid points, location information including complex shapes can be easily considered. Our layout algorithm includes the spring embedder cost as a component of the cost function. We further extend the layout algorithm to enable dynamic update of the positions and sizes of compartments at each step. The new spring embedder-based grid-layout algorithm and a spring embedder algorithm are applied to three biological pathways; endothelial cell model, Fas-induced apoptosis model, and C. elegans cell fate simulation model. From the positional constraints, all the results of our algorithm satisfy location information, and hence, more comprehensible layouts are obtained as compared to the spring embedder algorithm. From the comparison of the number of crossings, the results of the grid-layout-based algorithm tend to contain more crossings than those of the spring embedder algorithm due to

  1. Efficient string similarity join in multi-core and distributed systems.

    Science.gov (United States)

    Yan, Cairong; Zhao, Xue; Zhang, Qinglong; Huang, Yongfeng

    2017-01-01

    In big data area a significant challenge about string similarity join is to find all similar pairs more efficiently. In this paper, we propose a parallel processing framework for efficient string similarity join. First, the input is split into some disjoint small subsets according to the joint frequency distribution and the interval distribution of strings. Then the filter-verification strategy is adopted in the computation of string similarity for each subset so that the number of candidate pairs is reduced before an effective pruning strategy is used to improve the performance. Finally, the operation of string join is executed in parallel. Para-Join algorithm based on the multi-threading technique is proposed to implement the framework in a multi-core system while Pada-Join algorithm based on Spark platform is proposed to implement the framework in a cluster system. We prove that Para-Join and Pada-Join cannot only avoid reduplicate computation but also ensure the completeness of the result. Experimental results show that Para-Join can achieve high efficiency and significantly outperform than state-of-the-art approaches, meanwhile, Pada-Join can work on large datasets.

  2. Distributed Bees Algorithm Parameters Optimization for a Cost Efficient Target Allocation in Swarms of Robots

    Directory of Open Access Journals (Sweden)

    Álvaro Gutiérrez

    2011-11-01

    Full Text Available Swarms of robots can use their sensing abilities to explore unknown environments and deploy on sites of interest. In this task, a large number of robots is more effective than a single unit because of their ability to quickly cover the area. However, the coordination of large teams of robots is not an easy problem, especially when the resources for the deployment are limited. In this paper, the Distributed Bees Algorithm (DBA, previously proposed by the authors, is optimized and applied to distributed target allocation in swarms of robots. Improved target allocation in terms of deployment cost efficiency is achieved through optimization of the DBA’s control parameters by means of a Genetic Algorithm. Experimental results show that with the optimized set of parameters, the deployment cost measured as the average distance traveled by the robots is reduced. The cost-efficient deployment is in some cases achieved at the expense of increased robots’ distribution error. Nevertheless, the proposed approach allows the swarm to adapt to the operating conditions when available resources are scarce.

  3. Decreasing-Rate Pruning Optimizes the Construction of Efficient and Robust Distributed Networks.

    Directory of Open Access Journals (Sweden)

    Saket Navlakha

    2015-07-01

    Full Text Available Robust, efficient, and low-cost networks are advantageous in both biological and engineered systems. During neural network development in the brain, synapses are massively over-produced and then pruned-back over time. This strategy is not commonly used when designing engineered networks, since adding connections that will soon be removed is considered wasteful. Here, we show that for large distributed routing networks, network function is markedly enhanced by hyper-connectivity followed by aggressive pruning and that the global rate of pruning, a developmental parameter not previously studied by experimentalists, plays a critical role in optimizing network structure. We first used high-throughput image analysis techniques to quantify the rate of pruning in the mammalian neocortex across a broad developmental time window and found that the rate is decreasing over time. Based on these results, we analyzed a model of computational routing networks and show using both theoretical analysis and simulations that decreasing rates lead to more robust and efficient networks compared to other rates. We also present an application of this strategy to improve the distributed design of airline networks. Thus, inspiration from neural network formation suggests effective ways to design distributed networks across several domains.

  4. mHealthMon: toward energy-efficient and distributed mobile health monitoring using parallel offloading.

    Science.gov (United States)

    Ahnn, Jong Hoon; Potkonjak, Miodrag

    2013-10-01

    Although mobile health monitoring where mobile sensors continuously gather, process, and update sensor readings (e.g. vital signals) from patient's sensors is emerging, little effort has been investigated in an energy-efficient management of sensor information gathering and processing. Mobile health monitoring with the focus of energy consumption may instead be holistically analyzed and systematically designed as a global solution to optimization subproblems. This paper presents an attempt to decompose the very complex mobile health monitoring system whose layer in the system corresponds to decomposed subproblems, and interfaces between them are quantified as functions of the optimization variables in order to orchestrate the subproblems. We propose a distributed and energy-saving mobile health platform, called mHealthMon where mobile users publish/access sensor data via a cloud computing-based distributed P2P overlay network. The key objective is to satisfy the mobile health monitoring application's quality of service requirements by modeling each subsystem: mobile clients with medical sensors, wireless network medium, and distributed cloud services. By simulations based on experimental data, we present the proposed system can achieve up to 10.1 times more energy-efficient and 20.2 times faster compared to a standalone mobile health monitoring application, in various mobile health monitoring scenarios applying a realistic mobility model.

  5. Toward energy-efficient and distributed mobile health monitoring using parallel offloading.

    Science.gov (United States)

    Ahnn, Jong Hoon; Potkonjak, Miodrag

    2013-01-01

    Although mobile health monitoring where mobile sensors continuously gather, process, and update sensor readings (e.g. vital signals) from patient's sensors is emerging, little effort has been investigated in an energy-efficient management of sensor information gathering and processing. Mobile health monitoring with the focus of energy consumption may instead be holistically analyzed and systematically designed as a global solution to optimization subproblems. We propose a distributed and energy-saving mobile health platform, called mHealthMon where mobile users publish/access sensor data via a cloud computing-based distributed P2P overlay network. The key objective is to satisfy the mobile health monitoring application's quality of service requirements by modeling each subsystem: mobile clients with medical sensors, wireless network medium, and distributed cloud services. By simulations based on experimental data, we present the proposed system can achieve up to 10.1 times more energy-efficient and 20.2 times faster compared to a standalone mobile health monitoring application, in various mobile health monitoring scenarios applying a realistic mobility model.

  6. Efficient calculation of steady state probability distribution for stochastic biochemical reaction network.

    Science.gov (United States)

    Karim, Shahriar; Buzzard, Gregery T; Umulis, David M

    2012-01-01

    The Steady State (SS) probability distribution is an important quantity needed to characterize the steady state behavior of many stochastic biochemical networks. In this paper, we propose an efficient and accurate approach to calculating an approximate SS probability distribution from solution of the Chemical Master Equation (CME) under the assumption of the existence of a unique deterministic SS of the system. To find the approximate solution to the CME, a truncated state-space representation is used to reduce the state-space of the system and translate it to a finite dimension. The subsequent ill-posed eigenvalue problem of a linear system for the finite state-space can be converted to a well-posed system of linear equations and solved. The proposed strategy yields efficient and accurate estimation of noise in stochastic biochemical systems. To demonstrate the approach, we applied the method to characterize the noise behavior of a set of biochemical networks of ligand-receptor interactions for Bone Morphogenetic Protein (BMP) signaling. We found that recruitment of type II receptors during the receptor oligomerization by itself doesn't not tend to lower noise in receptor signaling, but regulation by a secreted co-factor may provide a substantial improvement in signaling relative to noise. The steady state probability approximation method shortened the time necessary to calculate the probability distributions compared to earlier approaches, such as Gillespie's Stochastic Simulation Algorithm (SSA) while maintaining high accuracy.

  7. Optimal Strategy of Efficiency Power Plant with Battery Electric Vehicle in Distribution Network

    Science.gov (United States)

    Ma, Tao; Su, Su; Li, Shunxin; Wang, Wei; Yang, Tiantian; Li, Mengjuan; Ota, Yutaka

    2017-05-01

    With the popularity of electric vehicles (EVs), such as plug-in electric vehicles (PHEVs) and battery electric vehicles (BEVs), an optimal strategy for the coordination of BEVs charging is proposed in this paper. The proposed approach incorporates the random behaviours and regular behaviours of BEV drivers in urban environment. These behaviours lead to the stochastic nature of the charging demand. The optimal strategy is used to guide the coordinated charging at different time to maximize the efficiency of virtual power plant (VPP). An innovative peer-to-peer system is used with BEVs to achieve the goals. The actual behaviours of vehicles in a campus is used to validate the proposed approach, and the simulation results show that the optimal strategy can not only maximize the utilization ratio of efficiency power plant, but also do not need additional energies from distribution grid.

  8. Exploring Efficiencies in Data Reduction, Analysis, and Distribution in the Exascale Era

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    DataDirect Networks (DDN) is world leader in massively scalable storage. Fellinger will discuss how the growth of data sets beyond the petabyte boundary presents new challenges to researchers in delivering and extracting usable information. He will also explore a Big Data processing architecture that overcomes constraints in network bandwidth and service layers in large-scale data distribution to enable researchers to request raw data through a filter or an analysis library. This technology, operating directly within the storage device, enables the reduction of service latency and process cycles to provide a more efficient feedback loop in iterative scientific experiments to increase data-intensive processing efficiency by up to 400%. About the speaker Dave Fellinger has over three decades of engineering experience, including film systems, ASIC design and development, GaAs semiconductor manufacture, RAID and storage systems, and video processing devices, and has architected high-performance storage syst...

  9. Spatiotemporal distribution of location and object effects in the electromyographic activity of upper extremity muscles during reach-to-grasp

    Science.gov (United States)

    Rouse, Adam G.

    2016-01-01

    In reaching to grasp an object, proximal muscles that act on the shoulder and elbow classically have been viewed as transporting the hand to the intended location, while distal muscles that act on the fingers simultaneously shape the hand to grasp the object. Prior studies of electromyographic (EMG) activity in upper extremity muscles therefore have focused, by and large, either on proximal muscle activity during reaching to different locations or on distal muscle activity as the subject grasps various objects. Here, we examined the EMG activity of muscles from the shoulder to the hand, as monkeys reached and grasped in a task that dissociated location and object. We quantified the extent to which variation in the EMG activity of each muscle depended on location, on object, and on their interaction—all as a function of time. Although EMG variation depended on both location and object beginning early in the movement, an early phase of substantial location effects in muscles from proximal to distal was followed by a later phase in which object effects predominated throughout the extremity. Interaction effects remained relatively small. Our findings indicate that neural control of reach-to-grasp may occur largely in two sequential phases: the first, serving to project the entire upper extremity toward the intended location, and the second, acting predominantly to shape the entire extremity for grasping the object. PMID:27009156

  10. Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

    Science.gov (United States)

    Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

    2014-09-09

    A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

  11. Dynamics of electricity efficiency in commercial air-distribution systems in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Christiansson, Lena

    1996-04-01

    This paper illustrates the long-term potential for reducing future electricity demand for air-distribution in commercial buildings in Sweden. The objective has been to develop a general quantitative scenario-based framework to describe some possible paths for electricity demand for air distribution and to analyze how governmental and utility-sponsored policy measures can affect electricity demand. The focus is on improved electricity efficiency, i.e. a reduction of electricity demand for the same level of services. The results suggest that higher electricity prices will not be very effective in reducing electricity demand, whereas significant electricity savings can be reached by implementing various policy programs, particularly standards. 56 refs, 4 figs, 5 tabs

  12. An Efficient Scheme for Aggregation and Presentation of Network Performance in Distributed Brokering Systems

    Directory of Open Access Journals (Sweden)

    Gurhan Gunduz

    2003-12-01

    Full Text Available The Internet is presently being used to support increasingly complex interaction models as a result of more and more applications, services and frameworks becoming network centric. Efficient utilization of network and networkedresources is of paramount importance. Network performance gathering is a precursor to any scheme that seeks to provide adaptive routing capabilities for interactions. In this paper we present a network performance aggregation framework that is extensible and appropriate for distributed messaging systems that span multiple realms, disparate communication protocols and support different applications.

  13. Distribution and Antioxidant Efficiency of Resveratrol in Stripped Corn Oil Emulsions

    Directory of Open Access Journals (Sweden)

    Sonia Losada-Barreiro

    2014-04-01

    Full Text Available We investigated the effects of resveratrol (RES on the oxidative stability of emulsions composed of stripped corn oil, acidic water and Tween 20 and determined its distribution in the intact emulsions by employing a well-established kinetic method. The distribution of RES is described by two partition constants, that between the oil-interfacial region, POI, and that between the aqueous and interfacial region, PWI. The partition constants, POI and PWI, are obtained in the intact emulsions from the variations of the observed rate constant, kobs, for the reaction between the hydrophobic 4-hexadecylbenzenediazonium ion and RES with the emulsifier volume fraction, ФI. The obtained POI and PWI values are quite high, PWI = 4374 and POI = 930, indicating that RES is primarily located in the interfacial region of the emulsions, %RESI > 90% at ФI = 0.005, increasing up to 99% at ФI = 0.04. The oxidative stability of the corn oil emulsions was determined by measuring the formation of conjugated dienes at a given time in the absence and in the presence of RES. The addition of RES did not improve their oxidative stability in spite that more than 90% of RES is located in the interfacial region of the emulsion, because of the very low radical scavenging activity of RES.

  14. An efficient reliability algorithm for locating design point using the combination of importance sampling concepts and response surface method

    Science.gov (United States)

    Shayanfar, Mohsen Ali; Barkhordari, Mohammad Ali; Roudak, Mohammad Amin

    2017-06-01

    Monte Carlo simulation (MCS) is a useful tool for computation of probability of failure in reliability analysis. However, the large number of required random samples makes it time-consuming. Response surface method (RSM) is another common method in reliability analysis. Although RSM is widely used for its simplicity, it cannot be trusted in highly nonlinear problems due to its linear nature. In this paper, a new efficient algorithm, employing the combination of importance sampling, as a class of MCS, and RSM is proposed. In the proposed algorithm, analysis starts with importance sampling concepts and using a represented two-step updating rule of design point. This part finishes after a small number of samples are generated. Then RSM starts to work using Bucher experimental design, with the last design point and a represented effective length as the center point and radius of Bucher's approach, respectively. Through illustrative numerical examples, simplicity and efficiency of the proposed algorithm and the effectiveness of the represented rules are shown.

  15. Simulation of Thermal Distribution and Airflow for Efficient Energy Consumption in a Small Data Centers

    Directory of Open Access Journals (Sweden)

    Jing Ni

    2017-04-01

    Full Text Available Data centers have become ubiquitous in the last few years in an attempt to keep pace with the processing and storage needs of the Internet and cloud computing. The steady growth in the heat densities of IT servers leads to a rise in the energy needed to cool them, and constitutes approximately 40% of the power consumed by data centers. However, many data centers feature redundant air conditioning systems that contribute to inefficient air distribution, which significantly increases energy consumption. This remains an insufficiently explored problem. In this paper, a typical, small data center with tiles for an air supply system with a raised floor is used. We use a fluent (Computational Fluid Dynamics, CFD to simulate thermal distribution and airflow, and investigate the optimal conditions of air distribution to save energy. The effects of the airflow outlet angle along the tile, the cooling temperature and the rate of airflow on the beta index as well as the energy utilization index are discussed, and the optimal conditions are obtained. The reasonable airflow distribution achieved using 3D CFD calculations and the parameter settings provided in this paper can help reduce the energy consumption of data centers by improving the efficiency of the air conditioning.

  16. Wireless system for location of permanent faults by short circuit current monitoring in electric power distribution network; Sistema wireless para localizacao de faltas permanentes atraves da monitoracao da corrente de curto-circuito em redes de distribuicao de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Machado, A.G.; Correa, A.C.; Machado, R.N. das M.; Ferreira, A.M.D.; Pinto, J.A.C. [Instituto Federal de Educacao, Ciencia e Tecnologia do Para (IFPA), Belem, PA (Brazil)], E-mail: alcidesmachado000@yahoo.com.br; Barra Junior, W. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Inst. de Tecnologia. Faculdade de Engenharia Eletrica], E-mail: walbarra@ufpa.br

    2009-07-01

    This paper presents the development of an automatic system for permanent short-circuits location in medium voltage (13.8 kV) electric power system distribution feeders, by indirect monitoring of the line current. When a permanent failure occurs, the developed system uses mobile telephony (GSM) text messages (SMS) to inform the power company operation center where the failure most likely took place. With this information in real time, the power company operation center may provide the network restoration in a faster and efficient way. (author)

  17. Modeling the Clustering of Distribution Centers around Amsterdam Airport Schiphol: location endowments, economies of agglomeration, locked-in logistics and policy implications

    NARCIS (Netherlands)

    P.M.J. Warffemius (Pim)

    2007-01-01

    textabstractThis thesis deals with the explanation of why European Distribution Centers (EDCs) cluster around Amsterdam Airport Schiphol. We present and test a new model of the clustering of EDCs around the airport. The Netherlands is an attractive location for EDCs. Approximately one-half of all

  18. Variation in Sitting Pressure Distribution and Location of the Points of Maximum Pressure with Rotation of the Pelvis, Gender and Body Characteristics

    NARCIS (Netherlands)

    Moes, C.C.M.

    2007-01-01

    The pressure distribution and the location of the points of maximum pressure, usually below the ischial tuberosities, was measured for subjects sitting on a flat, hard and horizontal support, and varying angle of the rotation of the pelvis. The pressure data were analyzed for force- and

  19. A model for distribution centers location-routing problem on a multimodal transportation network with a meta-heuristic solving approach

    Science.gov (United States)

    Fazayeli, Saeed; Eydi, Alireza; Kamalabadi, Isa Nakhai

    2017-07-01

    Nowadays, organizations have to compete with different competitors in regional, national and international levels, so they have to improve their competition capabilities to survive against competitors. Undertaking activities on a global scale requires a proper distribution system which could take advantages of different transportation modes. Accordingly, the present paper addresses a location-routing problem on multimodal transportation network. The introduced problem follows four objectives simultaneously which form main contribution of the paper; determining multimodal routes between supplier and distribution centers, locating mode changing facilities, locating distribution centers, and determining product delivery tours from the distribution centers to retailers. An integer linear programming is presented for the problem, and a genetic algorithm with a new chromosome structure proposed to solve the problem. Proposed chromosome structure consists of two different parts for multimodal transportation and location-routing parts of the model. Based on published data in the literature, two numerical cases with different sizes generated and solved. Also, different cost scenarios designed to better analyze model and algorithm performance. Results show that algorithm can effectively solve large-size problems within a reasonable time which GAMS software failed to reach an optimal solution even within much longer times.

  20. Impaired small-world network efficiency and dynamic functional distribution in patients with cirrhosis.

    Directory of Open Access Journals (Sweden)

    Tun-Wei Hsu

    Full Text Available Hepatic encephalopathy (HE is a complex neuropsychiatric syndrome and a major complication of liver cirrhosis. Dysmetabolism of the brain, related to elevated ammonia levels, interferes with intercortical connectivity and cognitive function. For evaluation of network efficiency, a 'small-world' network model can quantify the effectiveness of information transfer within brain networks. This study aimed to use small-world topology to investigate abnormalities of neuronal connectivity among widely distributed brain regions in patients with liver cirrhosis using resting-state functional magnetic resonance imaging (rs-fMRI. Seventeen cirrhotic patients without HE, 9 with minimal HE, 9 with overt HE, and 35 healthy controls were compared. The interregional correlation matrix was obtained by averaging the rs-fMRI time series over all voxels in each of the 90 regions using the automated anatomical labeling model. Cost and correlation threshold values were then applied to construct the functional brain network. The absolute and relative network efficiencies were calculated; quantifying distinct aspects of the local and global topological network organization. Correlations between network topology parameters, ammonia levels, and the severity of HE were determined using linear regression and ANOVA. The local and global topological efficiencies of the functional connectivity network were significantly disrupted in HE patients; showing abnormal small-world properties. Alterations in regional characteristics, including nodal efficiency and nodal strength, occurred predominantly in the association, primary, and limbic/paralimbic regions. The degree of network organization disruption depended on the severity of HE. Ammonia levels were also significantly associated with the alterations in local network properties. Results indicated that alterations in the rs-fMRI network topology of the brain were associated with HE grade; and that focal or diffuse lesions

  1. Cooperative ad hoc networks for energy and delay efficient content distribution with fast channel variations

    KAUST Repository

    Atat, Rachad

    2012-11-20

    Cooperative ad hoc networks for the efficient distribution of content of common interest are studied in the case of fast channel variations. Mobiles are grouped into cooperative clusters for the purpose of receiving the content with optimized energy efficiency. Data are sent to mobile terminals on a long range (LR) link, and then, the terminals exchange the content by using an appropriate short range wireless technology. When channel state information is available for the LR links, unicasting is used on the LR. When accurate channel state information is not available, threshold-based multicasting is implemented on the LR. Energy minimization is formulated as an optimization problem for each scenario, and the optimal solutions are determined in closed form in scenarios with fast channel variations. Results show significant energy savings in the proposed schemes compared with the noncooperative case and other previous related work. Furthermore, the energy minimizing solutions are shown to lead to reduced delay in the content distribution process. Practical implementation aspects of the proposed methods are also discussed. © 2012 John Wiley & Sons, Ltd.

  2. Review of water, lighting, and cooling energy efficiency measures for low-income homes located in warm climates

    Energy Technology Data Exchange (ETDEWEB)

    Martin, M.A.; Gettings, M.B.

    1998-02-01

    In support of the U.S. Department of Energy`s Weatherization Assistance Program, Oak Ridge National Laboratory has performed a literature review of weatherization measures applicable for homes located in warm climate regions. Sources for this information included: (1) documented engineering estimates, (2) vendor information, (3) reported performance from research and field tests, and (4) direct discussions with researchers, vendors, and field reporters. Estimated savings are extrapolated from reported energy savings and applied to the end-use energy consumption for low-income homes reported by the Energy Information Administration. Additionally, installation costs, savings-to-investment ratios, and parameters indicating performance sensitivity to issues such as occupancy, construction, client education, and maintenance requirements are presented. The report is comprised of two sections: (1) an overview of measure performance, and (2) an appendix. The overview of measures is in a tabular format, which allows for quick reference. More detailed discussions and references for each measure are presented in the Appendix and it is highly recommended that these be reviewed prior to measure selection.

  3. Efficient Algorithm for Locating and Sizing Series Compensation Devices in Large Transmission Grids: Solutions and Applications (PART II)

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, Vladimir [Moscow Inst. of Physics and Technology (MIPT), Moscow (Russian Federation); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-14

    In a companion manuscript, we developed a novel optimization method for placement, sizing, and operation of Flexible Alternating Current Transmission System (FACTS) devices to relieve transmission network congestion. Specifically, we addressed FACTS that provide Series Compensation (SC) via modification of line inductance. In this manuscript, this heuristic algorithm and its solutions are explored on a number of test cases: a 30-bus test network and a realistically-sized model of the Polish grid (~2700 nodes and ~3300 lines). The results on the 30-bus network are used to study the general properties of the solutions including non-locality and sparsity. The Polish grid is used as a demonstration of the computational efficiency of the heuristics that leverages sequential linearization of power flow constraints and cutting plane methods that take advantage of the sparse nature of the SC placement solutions. Using these approaches, the algorithm is able to solve an instance of Polish grid in tens of seconds. We explore the utility of the algorithm by analyzing transmission networks congested by (a) uniform load growth, (b) multiple overloaded configurations, and (c) sequential generator retirements

  4. Efficient Algorithm for Locating and Sizing Series Compensation Devices in Large Transmission Grids: Model Implementation (PART 1)

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, Vladimir [Moscow Inst. of Physics and Technology (MIPT), Moscow (Russian Federation); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-14

    We explore optimization methods for planning the placement, sizing and operations of Flexible Alternating Current Transmission System (FACTS) devices installed to relieve transmission grid congestion. We limit our selection of FACTS devices to Series Compensation (SC) devices that can be represented by modification of the inductance of transmission lines. Our master optimization problem minimizes the l1 norm of the inductance modification subject to the usual line thermal-limit constraints. We develop heuristics that reduce this non-convex optimization to a succession of Linear Programs (LP) which are accelerated further using cutting plane methods. The algorithm solves an instance of the MatPower Polish Grid model (3299 lines and 2746 nodes) in 40 seconds per iteration on a standard laptop—a speed up that allows the sizing and placement of a family of SC devices to correct a large set of anticipated congestions. We observe that our algorithm finds feasible solutions that are always sparse, i.e., SC devices are placed on only a few lines. In a companion manuscript, we demonstrate our approach on realistically-sized networks that suffer congestion from a range of causes including generator retirement. In this manuscript, we focus on the development of our approach, investigate its structure on a small test system subject to congestion from uniform load growth, and demonstrate computational efficiency on a realistically-sized network.

  5. EFFICIENT LIDAR POINT CLOUD DATA MANAGING AND PROCESSING IN A HADOOP-BASED DISTRIBUTED FRAMEWORK

    Directory of Open Access Journals (Sweden)

    C. Wang

    2017-10-01

    Full Text Available Light Detection and Ranging (LiDAR is one of the most promising technologies in surveying and mapping,city management, forestry, object recognition, computer vision engineer and others. However, it is challenging to efficiently storage, query and analyze the high-resolution 3D LiDAR data due to its volume and complexity. In order to improve the productivity of Lidar data processing, this study proposes a Hadoop-based framework to efficiently manage and process LiDAR data in a distributed and parallel manner, which takes advantage of Hadoop’s storage and computing ability. At the same time, the Point Cloud Library (PCL, an open-source project for 2D/3D image and point cloud processing, is integrated with HDFS and MapReduce to conduct the Lidar data analysis algorithms provided by PCL in a parallel fashion. The experiment results show that the proposed framework can efficiently manage and process big LiDAR data.

  6. Efficient content distribution for peer-to-peer overlays on mobile ad hoc networks

    Directory of Open Access Journals (Sweden)

    Afzal Mawji

    2011-07-01

    Full Text Available Peer-to-peer (P2P networks existing on a MANET are a natural evolution since both are decentralized and have dynamic topologies. As MANETs grow in use due to the increasing popularity of wireless mesh and 4G networks, it is expected that P2P applications will remain as a popular means of obtaining files. Network coding has been shown as an efficient means of sharing large files in a P2P network. With network coding, all file blocks have the same relative importance. This paper presents an efficient content distribution scheme that uses network coding to share large files in a P2P overlay running on a MANET. Peers request file blocks from multiple server nodes and servers multicast blocks to multiple receivers, providing efficient multipoint-to-multipoint communication. Simulation results show that compared to other common download techniques, the proposed scheme performs very well, having lower download time and energy consumption. Also, more peers participate in uploading the file, resulting in greater fairness.

  7. Evaluation of hydraulic efficiency of disinfection systems based on residence time distribution curves.

    Science.gov (United States)

    Wilson, Jordan M; Venayagamoorthy, Subhas K

    2010-12-15

    Hydraulic efficiency is a vital component in evaluating the disinfection capability of a contact system. Current practice evaluates these systems based upon the theoretical detention time (TDT) and the rising limb of the residence time distribution (RTD) curve. This evaluation methodology is expected because most systems are built based on TDT under a "black-box" approach to disinfection system design. Within recent years, the proliferation of computational fluid dynamics (CFD) has allowed a more insightful approach to disinfection system design and analysis. Research presented in this study using CFD models and physical tracer studies shows that evaluation methods based upon TDT tend to overestimate, severely in some instances, the actual hydraulic efficiency as obtained from the system's flow and scalar transport dynamics and subsequent RTD curve. The main objective of this study was to analyze an alternative measure of hydraulic efficiency, the ratio t(10)/t(90), where t(10) and t(90) are the time taken for 10 and 90% of the input concentration to be observed at the outlet of a system, respectively, for various disinfection systems, primarily a pipe loop system, pressurized tank system, and baffled tank system, from their respective RTD curves and compare the results to the current evaluation method.

  8. Synchronization in Array of Coupled Neural Networks with Unbounded Distributed Delay and Limited Transmission Efficiency

    Directory of Open Access Journals (Sweden)

    Xinsong Yang

    2013-01-01

    Full Text Available This paper investigates global synchronization in an array of coupled neural networks with time-varying delays and unbounded distributed delays. In the coupled neural networks, limited transmission efficiency between coupled nodes, which makes the model more practical, is considered. Based on a novel integral inequality and the Lyapunov functional method, sufficient synchronization criteria are derived. The derived synchronization criteria are formulated by linear matrix inequalities (LMIs and can be easily verified by using Matlab LMI Toolbox. It is displayed that, when some of the transmission efficiencies are limited, the dynamics of the synchronized state are different from those of the isolated node. Furthermore, the transmission efficiency and inner coupling matrices between nodes play important roles in the final synchronized state. The derivative of the time-varying delay can be any given value, and the time-varying delay can be unbounded. The outer-coupling matrices can be symmetric or asymmetric. Numerical simulations are finally given to demonstrate the effectiveness of the theoretical results.

  9. Efficient sampling in fragment-based protein structure prediction using an estimation of distribution algorithm.

    Directory of Open Access Journals (Sweden)

    David Simoncini

    Full Text Available Fragment assembly is a powerful method of protein structure prediction that builds protein models from a pool of candidate fragments taken from known structures. Stochastic sampling is subsequently used to refine the models. The structures are first represented as coarse-grained models and then as all-atom models for computational efficiency. Many models have to be generated independently due to the stochastic nature of the sampling methods used to search for the global minimum in a complex energy landscape. In this paper we present EdaFold(AA, a fragment-based approach which shares information between the generated models and steers the search towards native-like regions. A distribution over fragments is estimated from a pool of low energy all-atom models. This iteratively-refined distribution is used to guide the selection of fragments during the building of models for subsequent rounds of structure prediction. The use of an estimation of distribution algorithm enabled EdaFold(AA to reach lower energy levels and to generate a higher percentage of near-native models. [Formula: see text] uses an all-atom energy function and produces models with atomic resolution. We observed an improvement in energy-driven blind selection of models on a benchmark of EdaFold(AA in comparison with the [Formula: see text] AbInitioRelax protocol.

  10. DISTANCE ESTIMATION TO THE INTERPHASE-FAULT LOCATION IN THE DISTRIBUTIVE AIR-LINE GRIDS BASED ON ANALYSIS OF THE HARMONIC COMPONENT PARAMETERS OF THE OPERATING EMERGENCY CONDITIONS

    Directory of Open Access Journals (Sweden)

    E. V. Kalentionok

    2015-01-01

    Full Text Available Most techniques of the fault location based on the one-side measurement of the emergency mode characteristics use the short-circuit steady-regime parameters in the fundamental mode frequency. This approach compels to seek additional devices for tuning out the loadings of transformer-substations. Besides, it is susceptible to the nonlinearity effect of closed-circuit arc in the fault location which significantly reduces the accuracy of the remote location of the failure.For estimating the distance to the location of interphase failure on the aerial distributive transmission lines the article proposes a new technique employing the harmonic components of the operating emergency parameters. The algorithm of the present method realization includes: taking down oscillograms of the emergency-mode parameter values (e. g. in doublephase failure – the short-circuit current, the linear voltage between the faulty phases with necessary discretization interval; expansion of the operating emergency parameters in a Fourier series (realized with a quick Fourier expansion algorithm; estimating the distance to the fault location by the analytical expression; performing the statistical analysis of a row of distance values and finding the most probable distance to the fault location.For effectiveness investigation of the proposed method of trapping harmonic components the paper considers a 10 kV distributive electrical grid feeding nine transformer substations. The authors performed calculation of normal and emergency modes utilizing computer program MatLab in dynamic simulating environment Simulink. The arc is represented by a block describing the linearized dynamic volt-ampere characteristic of the arc. The built characteristic curves demonstrate dependence of the fault-location distance value from the frequency at which this value is obtained and the number if its reiterations. Based on the calculations, the authors establish that the accuracy of the distance

  11. Evaluation of hypocenter location techniques with applications to southern Utah: regional earthquake distributions and seismicity of geothermal areas

    Energy Technology Data Exchange (ETDEWEB)

    Wechsler, D.J.; Smith, R.B.

    1979-12-01

    Three techniques for the computation of earthquake hypocenter locations were compared through empirical results of synthetic test cases utilizing four different computer programs. The three approaches: (1) the single event method, (2) the master event method, and (3) the joint hypocenter determination method, were analyzed with respect to their application to regional (epicenter-to-station distances from 10 to 500 km) and local (epicentral distances from 0 to 70 km) seismic network recording situations. It was found that the joint hypocenter technique can significantly correct for inadequacies in assumed velocity models by simultaneous computation of station adjustments. Earthquakes located using the joint hypocenter technique are located more precisely with respect to each other. The joint epicenter location technique was then applied to relocations of epicenters in southern Utah below 40/sup 0/N latitude with the intent of resolving some spatial relationships of epicenter occurrence on this regional scale. Earthquakes in Utah occur in a diffuse zone 150 km to 200 km wide that coincides with the physiographic boundary of the Colorado Plateau. Swarm activity is prevalent where the zone changes from a north-south to a southwest orientation, but except for a cluster northwest of Cedar City, the only major alignments of epicenters are north-south.

  12. Applied Distributed Model Predictive Control for Energy Efficient Buildings and Ramp Metering

    Science.gov (United States)

    Koehler, Sarah Muraoka

    Industrial large-scale control problems present an interesting algorithmic design challenge. A number of controllers must cooperate in real-time on a network of embedded hardware with limited computing power in order to maximize system efficiency while respecting constraints and despite communication delays. Model predictive control (MPC) can automatically synthesize a centralized controller which optimizes an objective function subject to a system model, constraints, and predictions of disturbance. Unfortunately, the computations required by model predictive controllers for large-scale systems often limit its industrial implementation only to medium-scale slow processes. Distributed model predictive control (DMPC) enters the picture as a way to decentralize a large-scale model predictive control problem. The main idea of DMPC is to split the computations required by the MPC problem amongst distributed processors that can compute in parallel and communicate iteratively to find a solution. Some popularly proposed solutions are distributed optimization algorithms such as dual decomposition and the alternating direction method of multipliers (ADMM). However, these algorithms ignore two practical challenges: substantial communication delays present in control systems and also problem non-convexity. This thesis presents two novel and practically effective DMPC algorithms. The first DMPC algorithm is based on a primal-dual active-set method which achieves fast convergence, making it suitable for large-scale control applications which have a large communication delay across its communication network. In particular, this algorithm is suited for MPC problems with a quadratic cost, linear dynamics, forecasted demand, and box constraints. We measure the performance of this algorithm and show that it significantly outperforms both dual decomposition and ADMM in the presence of communication delay. The second DMPC algorithm is based on an inexact interior point method which is

  13. CycleFreeFlux: efficient removal of thermodynamically infeasible loops from flux distributions.

    Science.gov (United States)

    Desouki, Abdelmoneim Amer; Jarre, Florian; Gelius-Dietrich, Gabriel; Lercher, Martin J

    2015-07-01

    Constraint-based metabolic modeling methods such as Flux Balance Analysis (FBA) are routinely used to predict metabolic phenotypes, e.g. growth rates, ATP yield or the fitness of gene knockouts. One frequent difficulty of constraint-based solutions is the inclusion of thermodynamically infeasible loops (or internal cycles), which add nonbiological fluxes to the predictions. We propose a simple postprocessing of constraint-based solutions, which removes internal cycles from any given flux distribution [Formula: see text] without disturbing other fluxes not involved in the loops. This new algorithm, termed CycleFreeFlux, works by minimizing the sum of absolute fluxes [Formula: see text] while (i) conserving the exchange fluxes and (ii) using the fluxes of the original solution to bound the new flux distribution. This strategy reduces internal fluxes until at least one reaction of every possible internal cycle is inactive, a necessary and sufficient condition for the thermodynamic feasibility of a flux distribution. If alternative representations of the input flux distribution in terms of elementary flux modes exist that differ in their inclusion of internal cycles, then CycleFreeFlux is biased towards solutions that maintain the direction given by [Formula: see text] and towards solutions with lower total flux [Formula: see text]. Our method requires only one additional linear optimization, making it computationally very efficient compared to alternative strategies. We provide freely available R implementations for the enumeration of thermodynamically infeasible cycles as well as for cycle-free FBA solutions, flux variability calculations and random sampling of solution spaces. lercher@cs.uni-duesseldorf.de. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Efficient implementation of multidimensional fast fourier transform on a distributed-memory parallel multi-node computer

    Energy Technology Data Exchange (ETDEWEB)

    Bhanot, Gyan V [Princeton, NJ; Chen, Dong [Croton-On-Hudson, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

    2012-01-10

    The present in invention is directed to a method, system and program storage device for efficiently implementing a multidimensional Fast Fourier Transform (FFT) of a multidimensional array comprising a plurality of elements initially distributed in a multi-node computer system comprising a plurality of nodes in communication over a network, comprising: distributing the plurality of elements of the array in a first dimension across the plurality of nodes of the computer system over the network to facilitate a first one-dimensional FFT; performing the first one-dimensional FFT on the elements of the array distributed at each node in the first dimension; re-distributing the one-dimensional FFT-transformed elements at each node in a second dimension via "all-to-all" distribution in random order across other nodes of the computer system over the network; and performing a second one-dimensional FFT on elements of the array re-distributed at each node in the second dimension, wherein the random order facilitates efficient utilization of the network thereby efficiently implementing the multidimensional FFT. The "all-to-all" re-distribution of array elements is further efficiently implemented in applications other than the multidimensional FFT on the distributed-memory parallel supercomputer.

  15. Efficient heuristic algorithm used for optimal capacitor placement in distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Segura, Silvio; Rider, Marcos J. [Department of Electric Energy Systems, University of Campinas, Campinas, Sao Paulo (Brazil); Romero, Ruben [Faculty of Engineering of Ilha Solteira, Paulista State University, Ilha Solteira, Sao Paulo (Brazil)

    2010-01-15

    An efficient heuristic algorithm is presented in this work in order to solve the optimal capacitor placement problem in radial distribution systems. The proposal uses the solution from the mathematical model after relaxing the integrality of the discrete variables as a strategy to identify the most attractive bus to add capacitors to each step of the heuristic algorithm. The relaxed mathematical model is a non-linear programming problem and is solved using a specialized interior point method. The algorithm still incorporates an additional strategy of local search that enables the finding of a group of quality solutions after small alterations in the optimization strategy. Proposed solution methodology has been implemented and tested in known electric systems getting a satisfactory outcome compared with metaheuristic methods. The tests carried out in electric systems known in specialized literature reveal the satisfactory outcome of the proposed algorithm compared with metaheuristic methods. (author)

  16. An efficient two-tier causal protocol for mobile distributed systems.

    Science.gov (United States)

    Dominguez, Eduardo Lopez; Pomares Hernandez, Saul E; Gomez, Gustavo Rodriguez; Medina, Maria Auxilio

    2013-01-01

    Causal ordering is a useful tool for mobile distributed systems (MDS) to reduce the non-determinism induced by three main aspects: host mobility, asynchronous execution, and unpredictable communication delays. Several causal protocols for MDS exist. Most of them, in order to reduce the overhead and the computational cost over wireless channels and mobile hosts (MH), ensure causal ordering at and according to the causal view of the Base Stations. Nevertheless, these protocols introduce certain disadvantage, such as unnecessary inhibition at the delivery of messages. In this paper, we present an efficient causal protocol for groupware that satisfies the MDS's constraints, avoiding unnecessary inhibitions and ensuring the causal delivery based on the view of the MHs. One interesting aspect of our protocol is that it dynamically adapts the causal information attached to each message based on the number of messages with immediate dependency relation, and this is not directly proportional to the number of MHs.

  17. An efficient two-tier causal protocol for mobile distributed systems.

    Directory of Open Access Journals (Sweden)

    Eduardo Lopez Dominguez

    Full Text Available Causal ordering is a useful tool for mobile distributed systems (MDS to reduce the non-determinism induced by three main aspects: host mobility, asynchronous execution, and unpredictable communication delays. Several causal protocols for MDS exist. Most of them, in order to reduce the overhead and the computational cost over wireless channels and mobile hosts (MH, ensure causal ordering at and according to the causal view of the Base Stations. Nevertheless, these protocols introduce certain disadvantage, such as unnecessary inhibition at the delivery of messages. In this paper, we present an efficient causal protocol for groupware that satisfies the MDS's constraints, avoiding unnecessary inhibitions and ensuring the causal delivery based on the view of the MHs. One interesting aspect of our protocol is that it dynamically adapts the causal information attached to each message based on the number of messages with immediate dependency relation, and this is not directly proportional to the number of MHs.

  18. Regulating the spatial distribution of metal nanoparticles within metal-organic frameworks to enhance catalytic efficiency

    Science.gov (United States)

    Yang, Qiu; Liu, Wenxian; Wang, Bingqing; Zhang, Weina; Zeng, Xiaoqiao; Zhang, Cong; Qin, Yongji; Sun, Xiaoming; Wu, Tianpin; Liu, Junfeng; Huo, Fengwei; Lu, Jun

    2017-01-01

    Composites incorporating metal nanoparticles (MNPs) within metal-organic frameworks (MOFs) have broad applications in many fields. However, the controlled spatial distribution of the MNPs within MOFs remains a challenge for addressing key issues in catalysis, for example, the efficiency of catalysts due to the limitation of molecular diffusion within MOF channels. Here we report a facile strategy that enables MNPs to be encapsulated into MOFs with controllable spatial localization by using metal oxide both as support to load MNPs and as a sacrificial template to grow MOFs. This strategy is versatile to a variety of MNPs and MOF crystals. By localizing the encapsulated MNPs closer to the surface of MOFs, the resultant MNPs@MOF composites not only exhibit effective selectivity derived from MOF cavities, but also enhanced catalytic activity due to the spatial regulation of MNPs as close as possible to the MOF surface. PMID:28195131

  19. Methodology for the Efficient Progressive Distribution and Visualization of 3D Building Objects

    Directory of Open Access Journals (Sweden)

    Bo Mao

    2016-10-01

    Full Text Available Three-dimensional (3D, city models have been applied in a variety of fields. One of the main problems in 3D city model utilization, however, is the large volume of data. In this paper, a method is proposed to generalize the 3D building objects in 3D city models at different levels of detail, and to combine multiple Levels of Detail (LODs for a progressive distribution and visualization of the city models. First, an extended structure for multiple LODs of building objects, BuildingTree, is introduced that supports both single buildings and building groups; second, constructive solid geometry (CSG representations of buildings are created and generalized. Finally, the BuildingTree is stored in the NoSQL database MongoDB for dynamic visualization requests. The experimental results indicate that the proposed progressive method can efficiently visualize 3D city models, especially for large areas.

  20. Energy-Efficient Distributed Filtering in Sensor Networks: A Unified Switched System Approach.

    Science.gov (United States)

    Zhang, Dan; Shi, Peng; Zhang, Wen-An; Yu, Li

    2016-04-21

    This paper is concerned with the energy-efficient distributed filtering in sensor networks, and a unified switched system approach is proposed to achieve this goal. For the system under study, the measurement is first sampled under nonuniform sampling periods, then the local measurement elements are selected and quantized for transmission. Then, the transmission rate is further reduced to save constrained power in sensors. Based on the switched system approach, a unified model is presented to capture the nonuniform sampling, the measurement size reduction, the transmission rate reduction, the signal quantization, and the measurement missing phenomena. Sufficient conditions are obtained such that the filtering error system is exponentially stable in the mean-square sense with a prescribed H∞ performance level. Both simulation and experiment studies are given to show the effectiveness of the proposed new design technique.

  1. Efficient optimization of lithographic process conditions using a distributed, combined global/local search approach

    Science.gov (United States)

    Fühner, Tim; Popp, Stephan; Dürr, Christoph; Erdmann, Andreas

    2006-03-01

    This paper presents improvements and extensions that have been applied to our earlier presented approach of mutually optimizing lithographic illumination and mask settings. Our work aims at two aspects: (1) improvements of the optimization approach and (2) of the simulation scheme used for the optimization. As described earlier, the main problem of the proposed optimization approach is the high requirement of computation time. One solution is to extensively distribute calculations onto different computers. As an alternative to the former approach using MPI, a new improved technique is proposed, which makes use of the Python powered framework Twisted. This allows for a fail-safe and load-balanced distribution of calculations in a heterogeneous network environment. Another enhancement is the integration of local optimization routines into the proposed concept. For that, the state-of-the-art optimization toolkit of Matlab has been integrated into our approach. By combining our genetic algorithm with local search methods it is not only possible to increase the overall optimization performance, but also to evaluate local environments in the search space, which helps to assess the technical stability of solutions. As a first example the non-linear SQP (sequential quadratic programming) has been used, allowing for constrained problem specifications. Furthermore, the simulation itself was drastically improved in terms of efficiency. For example, instead of evaluating all solutions at the same numerical resolution, as a first step, a coarse-grained evaluation is performed, only if a solution's merit lies above a certain threshold, a detailed analysis at a higher (numerical) resolution is conducted. Various tests demonstrate not only the increase in efficiency obtained with the newly incorporated measures, but also show new results for a combined optimization of different mask features.

  2. Efficiency effects of quality of service and environmental factors. Experience from Norwegian electricity distribution

    Energy Technology Data Exchange (ETDEWEB)

    Growitsch, Christian [WIK Wissenschaftliches Institut fuer Infrastruktur und Kommunikationsdienste GmbH, Bad Honnef (Germany). Dept. of Energy Markets and Energy Regulation; Jamasb, Tooraj [Edinburgh Univ. (United Kingdom). Dept. of Economics; Wetzel, Heike [Cologne Univ. (Germany). Dept. of Economics

    2010-08-15

    Since the 1990s, efficiency and benchmarking analysis has increasingly been used in network utilities research and regulation. A recurrent concern is the effect of environmental factors that are beyond the influence of firms (observable heterogeneity) and factors that are not identifiable (unobserved heterogeneity) on measured cost and quality performance of firms. This paper analyses the effect of geographic and weather factors and unobserved heterogeneity on a set of 128 Norwegian electricity distribution utilities for the 2001-2004 period. We utilize data on almost 100 geographic and weather variables to identify real economic inefficiency while controlling for observable and unobserved heterogeneity. We use the factor analysis technique to reduce the number of environmental factors into few composite variables and to avoid the problem of multicollinearity. We then estimate the established stochastic frontier models of Battese and Coelli (1992; 1995) and the recent true fixed effects models of Greene (2004; 2005) without and with environmental variables. In the former models some composite environmental variables have a significant effect on the performance of utilities. These effects vanish in the true fixed effects models. However, the latter models capture the entire unobserved heterogeneity and therefore show significantly higher average efficiency scores. (orig.)

  3. Energy Efficient Power Allocation for Distributed Antenna System over Shadowed Nakagami Fading Channel

    Directory of Open Access Journals (Sweden)

    Ying Wang

    2015-12-01

    Full Text Available In this paper, the energy efficiency (EE of downlink distributed antenna system (DAS with multiple receive antennas is investigated over composite fading channel that takes the path loss, shadow fading and Nakagami-m fading into account. Our aim is to maximize EE which is defined as the ratio of the transmission rate to the total consumed power under the constraints of maximum transmit power of each remote antenna. According to the definition of EE and using the upper bound of average EE, the optimized objective function is provided. Based on this, utilizing Karush-Kuhn-Tucker (KKT conditions and mathematical derivation, a suboptimal energy efficient power allocation (PA scheme is developed, and closed-form PA coefficients are obtained. The developed scheme has the EE performance close to the existing optimal scheme. Moreover, it has relatively lower complexity than the existing scheme because only the statistic channel information and less iteration are required. Besides, it includes the scheme in composite Rayleigh channel as a special case. Simulation results show the effectiveness of the developed scheme.

  4. Energy Efficient Cooperative Spectrum Sensing in Cognitive Radio Networks Using Distributed Dynamic Load Balanced Clustering Scheme

    Directory of Open Access Journals (Sweden)

    Muthukkumar R.

    2016-07-01

    Full Text Available Cognitive Radio (CR is a promising and potential technique to enable secondary users (SUs or unlicenced users to exploit the unused spectrum resources effectively possessed by primary users (PUs or licenced users. The proven clustering approach is used to organize nodes in the network into the logical groups to attain energy efficiency, network scalability, and stability for improving the sensing accuracy in CR through cooperative spectrum sensing (CSS. In this paper, a distributed dynamic load balanced clustering (DDLBC algorithm is proposed. In this algorithm, each member in the cluster is to calculate the cooperative gain, residual energy, distance, and sensing cost from the neighboring clusters to perform the optimal decision. Each member in a cluster participates in selecting a cluster head (CH through cooperative gain, and residual energy that minimises network energy consumption and enhances the channel sensing. First, we form the number of clusters using the Markov decision process (MDP model to reduce the energy consumption in a network. In this algorithm, CR users effectively utilize the PUs reporting time slots of unavailability. The simulation results reveal that the clusters convergence, energy efficiency, and accuracy of channel sensing increased considerably by using the proposed algorithm.

  5. Effect of Pressurized Metered Dose Inhaler Spray Characteristics and Particle Size Distribution on Drug Delivery Efficiency.

    Science.gov (United States)

    Yousefi, Morteza; Inthavong, Kiao; Tu, Jiyuan

    2017-10-01

    A key issue in pulmonary drug delivery is improvement of the delivery device for effective and targeted treatment. Pressurized metered dose inhalers (pMDIs) are the most popular aerosol therapy device for treating lung diseases. This article studies the effect of spray characteristics: injection velocity, spray cone angle, particle size distribution (PSD), and its mass median aerodynamic diameter (MMAD) on drug delivery. An idealized oral airway geometry, extending from mouth to the main bronchus, was connected to a pMDI device. Inhalation flow rates of 15, 30, and 60 L/min were used and drug particle tracking was a one-way coupled Lagrangian model. The results showed that most particles deposited in the pharynx, where the airway has a reduced cross-sectional area. Particle deposition generally decreased with initial spray velocity and with increased spray cone angle for 30 and 60 L/min flow rates. However, for 15 L/min flow rate, the deposition increased slightly with an increase in the spray velocity and cone angle. The effect of spray cone angle was more significant than the initial spray velocity on particle deposition. When the MMAD of a PSD was reduced, the deposition efficiency also reduces, suggesting greater rates of particle entry into the lung. The deposition rate showed negligible change when the MMAD was more than 8 μm. Spray injection angle and velocity change the drug delivery efficacy; however, the efficiency shows more sensitivity to the injection angle. The 30 L/min airflow rate delivers spray particles to the lung more efficiently than 15 and 60 L/min airflow rate, and reducing MMAD can help increase drug delivery to the lung.

  6. Energy efficient distributed cluster head scheduling scheme for two tiered wireless sensor network

    Directory of Open Access Journals (Sweden)

    G. Kannan

    2015-07-01

    Full Text Available Wireless Sensor Network (WSN provides a significant contribution in the emerging fields such as ambient intelligence and ubiquitous computing. In WSN, optimization and load balancing of network resources are critical concern to provide the intelligence for long duration. Since clustering the sensor nodes can significantly enhance overall system scalability and energy efficiency this paper presents a distributed cluster head scheduling (DCHS algorithm to achieve the network longevity in WSN. The major novelty of this work is that the network is divided into primary and secondary tiers based on received signal strength indication of sensor nodes from the base station. The proposed DCHS supports for two tier WSN architecture and gives suggestion to elect the cluster head nodes and gateway nodes for both primary and secondary tiers. The DCHS mechanism satisfies an ideal distribution of the cluster head among the sensor nodes and avoids frequent selection of cluster head, based on Received Signal Strength Indication (RSSI and residual energy level of the sensor nodes. Since the RSSI is the key parameter for this paper, the practical experiment was conducted to measure RSSI value by using MSP430F149 processor and CC2500 transceiver. The measured RSSI values were given input to the event based simulator to test the DCHS mechanism. The real time experimental study validated the proposed scheme for various scenarios.

  7. DLTAP: A Network-efficient Scheduling Method for Distributed Deep Learning Workload in Containerized Cluster Environment

    Directory of Open Access Journals (Sweden)

    Qiao Wei

    2017-01-01

    Full Text Available Deep neural networks (DNNs have recently yielded strong results on a range of applications. Training these DNNs using a cluster of commodity machines is a promising approach since training is time consuming and compute-intensive. Furthermore, putting DNN tasks into containers of clusters would enable broader and easier deployment of DNN-based algorithms. Toward this end, this paper addresses the problem of scheduling DNN tasks in the containerized cluster environment. Efficiently scheduling data-parallel computation jobs like DNN over containerized clusters is critical for job performance, system throughput, and resource utilization. It becomes even more challenging with the complex workloads. We propose a scheduling method called Deep Learning Task Allocation Priority (DLTAP which performs scheduling decisions in a distributed manner, and each of scheduling decisions takes aggregation degree of parameter sever task and worker task into account, in particularly, to reduce cross-node network transmission traffic and, correspondingly, decrease the DNN training time. We evaluate the DLTAP scheduling method using a state-of-the-art distributed DNN training framework on 3 benchmarks. The results show that the proposed method can averagely reduce 12% cross-node network traffic, and decrease the DNN training time even with the cluster of low-end servers.

  8. Power-efficient distributed resource allocation under goodput QoS constraints for heterogeneous networks

    Science.gov (United States)

    Andreotti, Riccardo; Del Fiorentino, Paolo; Giannetti, Filippo; Lottici, Vincenzo

    2016-12-01

    This work proposes a distributed resource allocation (RA) algorithm for packet bit-interleaved coded OFDM transmissions in the uplink of heterogeneous networks (HetNets), characterized by small cells deployed over a macrocell area and sharing the same band. Every user allocates its transmission resources, i.e., bits per active subcarrier, coding rate, and power per subcarrier, to minimize the power consumption while both guaranteeing a target quality of service (QoS) and accounting for the interference inflicted by other users transmitting over the same band. The QoS consists of the number of information bits delivered in error-free packets per unit of time, or goodput (GP), estimated at the transmitter by resorting to an efficient effective SNR mapping technique. First, the RA problem is solved in the point-to-point case, thus deriving an approximate yet accurate closed-form expression for the power allocation (PA). Then, the interference-limited HetNet case is examined, where the RA problem is described as a non-cooperative game, providing a solution in terms of generalized Nash equilibrium. Thanks to the closed-form of the PA, the solution analysis is based on the best response concept. Hence, sufficient conditions for existence and uniqueness of the solution are analytically derived, along with a distributed algorithm capable of reaching the game equilibrium.

  9. Simplified Equation to Evaluate the Stress Intensity Factor of an Arbitrarily Located Circumferential Crack in a Cylinder under Radial Temperature Distribution

    OpenAIRE

    飯井, 俊行; 渡邊, 勝彦

    1998-01-01

    A simplified equation to directly calculate the stress intensity factor of an arbitrarily located circumferential crack in a cylinder under radial temperature distribution was theoretically derived, based on the theory of cylindrical shell and compliance. The effects of the cylinder length and the crack position on the stress intensity factor can be evaluated by the equation. From the numerical illustration, it was shown that the stress intensity factor of a short cylinder is smaller than tha...

  10. [Measurements of location of body fat distribution: an assessment of colinearity with body mass, adiposity and stature in female adolescents].

    Science.gov (United States)

    Pereira, Patrícia Feliciano; Serrano, Hiara Miguel Stanciola; Carvalho, Gisele Queiroz; Ribeiro, Sônia Machado Rocha; Peluzio, Maria do Carmo Gouveia; Franceschini, Sylvia do Carmo Castro; Priore, Silvia Eloiza

    2015-01-01

    To verify the correlation between body fat location measurements with the body mass index (BMI), percentage of body fat (%BF) and stature, according to the nutritional status in female adolescents. A controlled cross sectional study was carried out with 113 adolescents (G1: 38 eutrophic, but with high body fat level, G2: 40 eutrophic and G3: 35 overweight) from public schools in Viçosa-MG, Brazil. The following measures have been assessed: weight, stature, waist circumference (WC), umbilical circumference (UC), hip circumference (HC), thigh circumference, waist-to-hip ratio (WHR), waist-to-stature ratio (WSR), waist-to-thigh ratio (WTR), conicity index (CI), sagittal abdominal diameter (SAD), coronal diameter (CD), central skinfolds (CS) and peripheral (PS). The %BF was assessed by tetrapolar electric bioimpedance. The increase of central fat, represented by WC, UC, WSR, SAD, CD and CS, and the increase of peripheral fat indicated by HC and thigh were proportional to the increase of BMI and %BF. WC and especially the UC showed the strongest correlations with adiposity. Weak correlation between WHR, WTR, CI and CS/PS with adiposity were observed. The stature showed correlation with almost all the fat location measures, being regular or weak with waist. The results indicate colinearity between body mass and total adiposity with central and peripheral adipose tissue. We recommend the use of UC for assessing nutritional status of adolescents, because it showed the highest ability to predict adiposity in each group, and also presented regular or weak correlation with stature. Copyright © 2014 Associação de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  11. Visibiome: an efficient microbiome search engine based on a scalable, distributed architecture.

    Science.gov (United States)

    Azman, Syafiq Kamarul; Anwar, Muhammad Zohaib; Henschel, Andreas

    2017-07-24

    Given the current influx of 16S rRNA profiles of microbiota samples, it is conceivable that large amounts of them eventually are available for search, comparison and contextualization with respect to novel samples. This process facilitates the identification of similar compositional features in microbiota elsewhere and therefore can help to understand driving factors for microbial community assembly. We present Visibiome, a microbiome search engine that can perform exhaustive, phylogeny based similarity search and contextualization of user-provided samples against a comprehensive dataset of 16S rRNA profiles environments, while tackling several computational challenges. In order to scale to high demands, we developed a distributed system that combines web framework technology, task queueing and scheduling, cloud computing and a dedicated database server. To further ensure speed and efficiency, we have deployed Nearest Neighbor search algorithms, capable of sublinear searches in high-dimensional metric spaces in combination with an optimized Earth Mover Distance based implementation of weighted UniFrac. The search also incorporates pairwise (adaptive) rarefaction and optionally, 16S rRNA copy number correction. The result of a query microbiome sample is the contextualization against a comprehensive database of microbiome samples from a diverse range of environments, visualized through a rich set of interactive figures and diagrams, including barchart-based compositional comparisons and ranking of the closest matches in the database. Visibiome is a convenient, scalable and efficient framework to search microbiomes against a comprehensive database of environmental samples. The search engine leverages a popular but computationally expensive, phylogeny based distance metric, while providing numerous advantages over the current state of the art tool.

  12. ZTEK`s ultra-high efficiency fuel cell/gas turbine system for distributed generation

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, M.; Nathanson, D. [Ztek Corp., Waltham, MA (United States); Bradshaw, D.T. [Tennessee Valley Authority, Chattanooga, TN (United States)] [and others

    1996-12-31

    Ztek`s Planar Solid Oxide Fuel Cell (SOFC) system has exceptional potential for utility electric power generation because of: simplicity of components construction, capability for low cost manufacturing, efficient recovery of very high quality by-product heat (up to 1000{degrees}C), and system integration simplicity. Utility applications of the Solid Oxide Fuel Cell are varied and include distributed generation units (sub-MW to 30MW capacity), repowering existing power plants (i.e. 30MW to 100MW), and multi-megawatt central power plants. A TVA/EPRI collaboration program involved functional testing of the advanced solid oxide fuel cell stacks and design scale-up for distributed power generation applications. The emphasis is on the engineering design of the utility modules which will be the building blocks for up to megawatt scale power plants. The program has two distinctive subprograms: Verification test on a 1 kW stack and 25kW module for utility demonstration. A 1 kW Planar SOFC stack was successfully operated for 15,000 hours as of December, 1995. Ztek began work on a 25kW SOFC Power System for TVA, which plans to install the 25kW SOFC at a host site for demonstration in 1997. The 25kW module is Ztek`s intended building block for the commercial use of the Planar SOFC. Systems of up to megawatt capacity can be obtained by packaging the modules in 2-dimensional or 3-dimensional arrays.

  13. Lunar pickup ions observed by ARTEMIS: Spatial and temporal distribution and constraints on species and source locations

    Science.gov (United States)

    Halekas, J. S.; Poppe, A. R.; Delory, G. T.; Sarantos, M.; Farrell, W. M.; Angelopoulos, V.; McFadden, J. P.

    2012-06-01

    ARTEMIS observes pickup ions around the Moon, at distances of up to 20,000 km from the surface. The observed ions form a plume with a narrow spatial and angular extent, generally seen in a single energy/angle bin of the ESA instrument. Though ARTEMIS has no mass resolution capability, we can utilize the analytically describable characteristics of pickup ion trajectories to constrain the possible ion masses that can reach the spacecraft at the observation location in the correct energy/angle bin. We find that most of the observations are consistent with a mass range of ˜20-45 amu, with a smaller fraction consistent with higher masses, and very few consistent with masses below ˜15 amu. With the assumption that the highest fluxes of pickup ions come from near the surface, the observations favor mass ranges of ˜20-24 and ˜36-40 amu. Although many of the observations have properties consistent with a surface or near-surface release of ions, some do not, suggesting that at least some of the observed ions have an exospheric source. Of all the proposed sources for ions and neutrals about the Moon, the pickup ion flux measured by ARTEMIS correlates best with the solar wind proton flux, indicating that sputtering plays a key role in either directly producing ions from the surface, or producing neutrals that subsequently become ionized.

  14. An Efficient Distributed Algorithm for Constructing Spanning Trees in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Rosana Lachowski

    2015-01-01

    Full Text Available Monitoring and data collection are the two main functions in wireless sensor networks (WSNs. Collected data are generally transmitted via multihop communication to a special node, called the sink. While in a typical WSN, nodes have a sink node as the final destination for the data traffic, in an ad hoc network, nodes need to communicate with each other. For this reason, routing protocols for ad hoc networks are inefficient for WSNs. Trees, on the other hand, are classic routing structures explicitly or implicitly used in WSNs. In this work, we implement and evaluate distributed algorithms for constructing routing trees in WSNs described in the literature. After identifying the drawbacks and advantages of these algorithms, we propose a new algorithm for constructing spanning trees in WSNs. The performance of the proposed algorithm and the quality of the constructed tree were evaluated in different network scenarios. The results showed that the proposed algorithm is a more efficient solution. Furthermore, the algorithm provides multiple routes to the sensor nodes to be used as mechanisms for fault tolerance and load balancing.

  15. Observation of Significant Quantum Efficiency Enhancement from a Polarized Photocathode with Distributed Bragg Reflector

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shukui [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Poelker, Matthew [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Stutzman, Marcy L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Chen, Yiqiao [SVT Associates, Inc., Eden Prairie, MN (United States); Moy, Aaron [SVT Associates, Inc., Eden Prairie, MN (United States)

    2015-09-01

    Polarized photocathodes with higher Quantum efficiency (QE) would help to reduce the technological challenge associated with producing polarized beams at milliampere levels, because less laser light would be required, which simplifies photocathode cooling requirements. And for a given amount of available laser power, higher QE would extend the photogun operating lifetime. The distributed Bragg reflector (DBR) concept was proposed to enhance the QE of strained-superlattice photocathodes by increasing the absorption of the incident photons using a Fabry-Perot cavity formed between the front surface of the photocathode and the substrate that includes a DBR, without compromising electron polarization. Here we present recent results showing QE enhancement of a GaAs/GaAsP strained-superlattice photocathode made with a DBR structure. Typically, a GaAs/GaAsP strained-superlattice photocathode without DBR provides a QE of 1%, at a laser wavelength corresponding to peak polarization. In comparison, the GaAs/GaAsP strained-superlattice photocathodes with DBR exhibited an enhancement of over 2 when the incident laser wavelength was tuned to meet the resonant condition for the Fabry-Perot resonator.

  16. An Efficient MapReduce-Based Parallel Clustering Algorithm for Distributed Traffic Subarea Division

    Directory of Open Access Journals (Sweden)

    Dawen Xia

    2015-01-01

    Full Text Available Traffic subarea division is vital for traffic system management and traffic network analysis in intelligent transportation systems (ITSs. Since existing methods may not be suitable for big traffic data processing, this paper presents a MapReduce-based Parallel Three-Phase K-Means (Par3PKM algorithm for solving traffic subarea division problem on a widely adopted Hadoop distributed computing platform. Specifically, we first modify the distance metric and initialization strategy of K-Means and then employ a MapReduce paradigm to redesign the optimized K-Means algorithm for parallel clustering of large-scale taxi trajectories. Moreover, we propose a boundary identifying method to connect the borders of clustering results for each cluster. Finally, we divide traffic subarea of Beijing based on real-world trajectory data sets generated by 12,000 taxis in a period of one month using the proposed approach. Experimental evaluation results indicate that when compared with K-Means, Par2PK-Means, and ParCLARA, Par3PKM achieves higher efficiency, more accuracy, and better scalability and can effectively divide traffic subarea with big taxi trajectory data.

  17. Study of detection efficiency distribution and areal homogeneity of SiPMs

    Energy Technology Data Exchange (ETDEWEB)

    Tesar, Michal; Jendrysik, Christian; Simon, Frank; Ninkovic, Jelena; Moser, Hans-Guenther; Richter, Rainer [Max-Planck-Institut for Physics, Munich (Germany)

    2012-07-01

    Silicon photomultipliers (SiPM) are a very attractive option for light detection in highly granular scintillator-based sampling calorimeters in future high energy physics experiments at Linear Colliders (ILC, CLIC). The CALICE collaboration has already successfully operated a 1 m{sup 3} physics prototype with about 8 000 small scintillator tiles, each read out by a SiPM, demonstrating the power of this new technology. We have developed a setup for the measurement of relative photon detection efficiency (PDE), crosstalk probability and other important characteristics of SiPMs to study the performance of different devices. The precise positioning system of the setup together with excellent focusing of the light source provides scanning capabilities that allow a study of the spatial distributions of PDE, crosstalk etc. over large sensor areas with sub-pixel resolution. A brief description of the setup, final results of a study of two types of Hamamatsu MPPCs and first scans of SiMPl devices, developed at MPI Semiconductor Lab, are presented.

  18. A High Efficiency DC-DC Converter Topology Suitable for Distributed Large Commercial and Utility Scale PV Systems

    Energy Technology Data Exchange (ETDEWEB)

    Agamy, Mohammed S; Harfman-Todorovic, Maja; Elasser, Ahmed; Steigerwald, Robert L; Sabate, Juan A; Chi, Song; McCann, Adam J; Zhang, Li; Mueller, Frank

    2012-09-01

    In this paper a DC-DC power converter for distributed photovoltaic plant architectures is presented. The proposed converter has the advantages of simplicity, high efficiency, and low cost. High efficiency is achieved by having a portion of the input PV power directly fed forward to the output without being processed by the converter. The operation of this converter also allows for a simplified maximum power point tracker design using fewer measurements

  19. Seasonal changes of trophic transfer efficiencies in a plankton food web derived from biomass size distributions and network analysis

    OpenAIRE

    Gaedke, Ursula; Straile, Dietmar

    1994-01-01

    The trophic transfer efficiencies in the planktonic food web of large, deep, and mesoeutrophic Lake Constance were derived independently from biomass size distributions and from mass-balanced carbon flow diagrams based on comprehensive data for biomass, production, and food web structure. The main emphasis was on the transfer of primary production to herbivores since this process dominates the flow of matter within the food web. Biomass size distributions offer an ecosystem approach which rel...

  20. D-Search: an efficient and exact search algorithm for large distribution sets

    OpenAIRE

    Matsubara, Yasuko; SAKURAI, Yasushi; Yoshikawa, Masatoshi

    2011-01-01

    Distribution data naturally arise in countless domains, such as meteorology, biology, geology, industry and economics. However, relatively little attention has been paid to data mining for large distribution sets. Given n distributions of multiple categories and a query distribution Q, we want to find similar clouds (i.e., distributions) to discover patterns, rules and outlier clouds. For example, consider the numerical case of sales of items, where, for each item sold, we record the unit pri...

  1. Efficient immune-GA method for DNOs in sizing and placement of distributed generation units

    OpenAIRE

    Soroudi, Alireza; Ehsan, Mehdi

    2011-01-01

    This paper proposes a hybrid heuristic optimization method based on genetic algorithm and immune systems to maximize the benefits of Distribution Network Operators (DNOs) accrued due to sizing and placement of Distributed Generation (DG) units in distribution networks. The effects of DG units in reducing the reinforcement costs and active power losses of distribution network have been investigated. In the presented method, the integration of DG units in distribution network is done considerin...

  2. EFFICIENCY OF GRID MAPPING METHOD FOR DETECTING NEW LOCATIONS OF RARE PLANTS (ON THE EXAMPLE OF THE SOUTHEASTERN PART OF OREL REGION

    Directory of Open Access Journals (Sweden)

    L. L. Kiselyova

    2017-01-01

    Full Text Available In Orel Region since 1999, work is being carried out to study floristic diversity using GIS technologies. One of thematic layers of the mapping database “Natural Resources of Orel Region”, created in the GIS MapInfo, is “Rare and Protected Plants of Orel Region”. This thematic layer contains point maps of 425 rare and protected plants in the region. In 2015, in the environment of the GIS MapInfo there was created a thematic layer “Flora of Orel Region”, containing grid maps of the distribution of 945 species of vascular plants in the southeastern part of the region.The purpose of this study was to evaluate the effectiveness of the grid mapping method to identify new locations of rare and protected plants by the example of the southeastern part of Orel Region.In 2015 the study of the flora of the 7 administrative districts of the southeastern part of Orel Region by the method of grid mapping resulted in identifying 77 new sites of 17 vascular plant species included in the Red Book of Orel Region, of which 24 new localities of 5 species included in the Red Book of the Russian Federation.For 9 species of the Red Book of Orel Region, the application of the grid mapping method allowed increasing significantly (from 60% to 100% the number of locations in the southeast of the region.The conducted research has shown that the grid mapping method is most effective for revealing new locations of rare and protected plants. 

  3. Nitrogen uptake, distribution, turnover, and efficiency of use in a CO2-enriched sweetgum forest

    Energy Technology Data Exchange (ETDEWEB)

    Norby, Richard J [ORNL; Iversen, Colleen M [ORNL

    2006-01-01

    The Progressive Nitrogen Limitation (PNL) hypothesis suggests that ecosystems in a CO2-enriched atmosphere will sequester C and N in long-lived biomass and soil organic pools, thereby limiting available N and constraining the continued response of net primary productivity to elevated [CO2]. Here, we present a six-year record of N dynamics of a sweetgum (Liquidambar styraciflua) stand exposed to elevated [CO2] in the free-air CO2 enrichment (FACE) experiment at Oak Ridge, Tennessee, USA. We also evaluate the concept of PNL for this ecosystem from the perspective of N uptake, content, distribution, and turnover, and N-use efficiency. Leaf N content was 11% lower on a leaf mass basis (NM) and 7% lower on a leaf area basis (N{sub A}) in CO2-enriched trees. However, there was no effect of [CO2] on total canopy N content. Resorption of N during senescence was not altered by [CO2], so NM of litter, but not total N content, was reduced. The NM of fine roots was not affected, but the total amount of N required for fine-root production increased significantly, reflecting the large stimulation of fine-root production in this stand. Hence, total N requirement of the trees was higher in elevated [CO2], and the increased requirement was met through an increase in N uptake rather than increased retranslocation of stored reserves. Increased N uptake was correlated with increased net primary productivity (NPP). N-use efficiency, however, did not change with CO2 enrichment because increased N productivity was offset by lower mean residence time of N in the trees. None of the measured responses of plant N dynamics in this ecosystem indicated the occurrence of PNL, and the stimulation of NPP by elevated [CO2] was sustained for the first six years of the experiment. Although there are some indications of developing changes in the N economy, the N supply in the soil at this site may be sufficient to meet an increasing demand for available N, especially as the roots of CO2-enriched trees

  4. In vivo evaluation of the effect of stimulus distribution on FIR statistical efficiency in event-related fMRI.

    Science.gov (United States)

    Jansma, J Martijn; de Zwart, Jacco A; van Gelderen, Peter; Duyn, Jeff H; Drevets, Wayne C; Furey, Maura L

    2013-05-15

    Technical developments in MRI have improved signal to noise, allowing use of analysis methods such as Finite impulse response (FIR) of rapid event related functional MRI (er-fMRI). FIR is one of the most informative analysis methods as it determines onset and full shape of the hemodynamic response function (HRF) without any a priori assumptions. FIR is however vulnerable to multicollinearity, which is directly related to the distribution of stimuli over time. Efficiency can be optimized by simplifying a design, and restricting stimuli distribution to specific sequences, while more design flexibility necessarily reduces efficiency. However, the actual effect of efficiency on fMRI results has never been tested in vivo. Thus, it is currently difficult to make an informed choice between protocol flexibility and statistical efficiency. The main goal of this study was to assign concrete fMRI signal to noise values to the abstract scale of FIR statistical efficiency. Ten subjects repeated a perception task with five random and m-sequence based protocol, with varying but, according to literature, acceptable levels of multicollinearity. Results indicated substantial differences in signal standard deviation, while the level was a function of multicollinearity. Experiment protocols varied up to 55.4% in standard deviation. Results confirm that quality of fMRI in an FIR analysis can significantly and substantially vary with statistical efficiency. Our in vivo measurements can be used to aid in making an informed decision between freedom in protocol design and statistical efficiency. Published by Elsevier B.V.

  5. Biomass distribution efficiency of rose cv. Charlotte grown in soil and substrates at second production peak

    Directory of Open Access Journals (Sweden)

    María Y González G

    2013-12-01

    Full Text Available Growing plants in substrates is an alternative for the production of roses under unfavorable soil conditions. The objective of this study was to determine the biomass distribution efficiency of rose cv. Charlotte grown in soil and substrates under greenhouse conditions until second production peak. In this trial, soil and substrates with 100% burned rice husk (100BR H; 65% burned rice husk: 35% coconut fiber (65BR H; 35% burned rice husk: 65% coconut fiber (35BR H; and 100% coconut fiber (100CF were used. The experimental design consisted of a randomized complete block design with three repetitions. Destructive sampling was carried out using whole plants and flowering stems at previously determined bud stages. Leaf area and dry matter in organs were measured and growth rate and physiological indexes were calculated. The assessed variables were fitted to logistic and exponential models. The plants grown in substrates with BR H (burned rice husk showed similar values regarding dry matter and fresh weight accumulation in organs. Plants in the soil treatment were the last ones to reach the different development stages of the flowering buds, while those that were grown in 100CF were the first ones. The treatments 35BR H and 100CF showed less growth of flowering stems, which was expressed in terms of relative dry matter increase per day. The plants grown in soil showed more dry matter in leaves and stems but less in flower buds. The 65BR H treatment showed some of the highest dry matter accumulations in leaves, stems and flower buds and also showed the highest leaf area ratio, leaf weight ratio, and specific leaf area values

  6. Efficient Energy Distribution in a Smart Grid using Multi-Player Games

    Directory of Open Access Journals (Sweden)

    Thomas Brihaye

    2016-07-01

    Full Text Available Algorithms and models based on game theory have nowadays become prominent techniques for the design of digital controllers for critical systems. Indeed, such techniques enable automatic synthesis: given a model of the environment and a property that the controller must enforce, those techniques automatically produce a correct controller, when it exists. In the present paper, we consider a class of concurrent, weighted, multi-player games that are well-suited to model and study the interactions of several agents who are competing for some measurable resources like energy. We prove that a subclass of those games always admit a Nash equilibrium, i.e. a situation in which all players play in such a way that they have no incentive to deviate. Moreover, the strategies yielding those Nash equilibria have a special structure: when one of the agents deviate from the equilibrium, all the others form a coalition that will enforce a retaliation mechanism that punishes the deviant agent. We apply those results to a real-life case study in which several smart houses that produce their own energy with solar panels, and can share this energy among them in micro-grid, must distribute the use of this energy along the day in order to avoid consuming electricity that must be bought from the global grid. We demonstrate that our theory allows one to synthesise an efficient controller for these houses: using penalties to be paid in the utility bill as an incentive, we force the houses to follow a pre-computed schedule that maximises the proportion of the locally produced energy that is consumed.

  7. A Location Privacy Aware Friend Locator

    DEFF Research Database (Denmark)

    Siksnys, Laurynas; Thomsen, Jeppe Rishede; Saltenis, Simonas

    2009-01-01

    to trade their location privacy for quality of service, limiting the attractiveness of the services. The challenge is to develop a communication-efficient solution such that (i) it detects proximity between a user and the user’s friends, (ii) any other party is not allowed to infer the location of the user...

  8. Calibrating and Controlling the Quantum Efficiency Distribution of Inhomogeneously Broadened Quantum Rods by Using a Mirror Ball

    DEFF Research Database (Denmark)

    Hansen, Per Lunnemann; Rabouw, Freddy T.; van Dijk-Moes, Relinde J. A.

    2013-01-01

    -in-rod emitters. The emitters are of large current interest due to their improved stability and reduced blinking. We retrieve a room-temperature ensemble average quantum efficiency of 0.87 ± 0.08 at a mean lifetime around 20 ns. We confirm a log-normal distribution of decay rates as often assumed in literature...

  9. The Optimization of Distributed Photovoltaic Comprehensive Efficiency Based on the Construction of Regional Integrated Energy Management System in China

    Directory of Open Access Journals (Sweden)

    Xiaohua Song

    2016-11-01

    Full Text Available In the context of energy crisis, environmental pollution, and energy abandoning in the large-scale centralized clean energy generation, distributed energy has become an inevitable trend in the development of China’s energy system. Distributed photovoltaic boasts great potential for development in China due to resource advantages and policy support. However, we need improve the efficiency of photovoltaic generation, which is restricted by technology and dislocation of supply and demand. With a view to optimizing the efficiency of distributed photovoltaic, based on the concept of comprehensive efficiency, this paper discusses the influencing factors and chooses the optimization direction according to system dynamics (SD. The optimizing content is further clarified on the basis of energy management system. From the perspective of technology, this paper puts forward optimization methods from resource side, energy conversion and demand side, and the simulation results of applying the three methods verify the feasibility of the method. Comprehensive efficiency would be improved as the result of regional integrated energy management system and policy mechanisms. The conclusions of this paper will provide theoretical basis and optimized reference for the improvement of distributed photovoltaic comprehensive utilization in China.

  10. BlueDetect: An iBeacon-Enabled Scheme for Accurate and Energy-Efficient Indoor-Outdoor Detection and Seamless Location-Based Service

    Directory of Open Access Journals (Sweden)

    Han Zou

    2016-02-01

    Full Text Available The location and contextual status (indoor or outdoor is fundamental and critical information for upper-layer applications, such as activity recognition and location-based services (LBS for individuals. In addition, optimizations of building management systems (BMS, such as the pre-cooling or heating process of the air-conditioning system according to the human traffic entering or exiting a building, can utilize the information, as well. The emerging mobile devices, which are equipped with various sensors, become a feasible and flexible platform to perform indoor-outdoor (IO detection. However, power-hungry sensors, such as GPS and WiFi, should be used with caution due to the constrained battery storage on mobile device. We propose BlueDetect: an accurate, fast response and energy-efficient scheme for IO detection and seamless LBS running on the mobile device based on the emerging low-power iBeacon technology. By leveraging the on-broad Bluetooth module and our proposed algorithms, BlueDetect provides a precise IO detection service that can turn on/off on-board power-hungry sensors smartly and automatically, optimize their performances and reduce the power consumption of mobile devices simultaneously. Moreover, seamless positioning and navigation services can be realized by it, especially in a semi-outdoor environment, which cannot be achieved by GPS or an indoor positioning system (IPS easily. We prototype BlueDetect on Android mobile devices and evaluate its performance comprehensively. The experimental results have validated the superiority of BlueDetect in terms of IO detection accuracy, localization accuracy and energy consumption.

  11. Size distributions of elemental carbon and its contribution to light extinction in urban and rural locations in the pearl river delta region, China

    Science.gov (United States)

    Yu, H.; Wu, C.; Wu, D.; Yu, J. Z.

    2010-06-01

    Elemental carbon (EC) in size-segregated aerosol samples were determined at five urban, one suburban, and one rural locations in the Pearl River Delta region in South China during 2006-2008 period. The size modal characteristics of EC were different at the urban and suburban/rural locations. The urban EC had a dominant condensation mode with a mass median aerodynamic diameter (MMAD) in the 0.36-0.43 μm range and a slightly less abundant mode in the droplet mode size (MMAD: 0.8-1.1 μm), while the suburban/rural EC had a prominent mode in the droplet mode size (MMAD: 0.7-1.1 μm) and a minor condensation mode (MMAD: 0.22-0.33 μm). Calculations using Mie theory and the measured size distributions of EC, organic carbon, and major inorganic ions indicate that EC-containing particles contributed 76±20% of the observed light extinction at the urban sites. Among the EC-containing particles, EC mass alone contributed 21±11% of the observed light extinction while non-EC materials on the EC particles (i.e., organic matter, ammonium sulfate, and water) contributed 55±15%. At the suburban/rural locations, EC-containing particles contributed 37-48% of the measured light extinction, with EC mass contributing 4-10% and non-EC coating materials contributing the remaining light extinction. Our results suggest that EC-containing particles were important to the overall light extinction in the urban atmospheres due to their more abundant presence from vehicular emissions. The EC-containing particles in the suburban/rural locations had a reduced but still significant contribution to light extinction budget.

  12. Size distributions of elemental carbon and its contribution to light extinction in urban and rural locations in the pearl river delta region, China

    Directory of Open Access Journals (Sweden)

    H. Yu

    2010-06-01

    Full Text Available Elemental carbon (EC in size-segregated aerosol samples were determined at five urban, one suburban, and one rural locations in the Pearl River Delta region in South China during 2006–2008 period. The size modal characteristics of EC were different at the urban and suburban/rural locations. The urban EC had a dominant condensation mode with a mass median aerodynamic diameter (MMAD in the 0.36–0.43 μm range and a slightly less abundant mode in the droplet mode size (MMAD: 0.8–1.1 μm, while the suburban/rural EC had a prominent mode in the droplet mode size (MMAD: 0.7–1.1 μm and a minor condensation mode (MMAD: 0.22–0.33 μm. Calculations using Mie theory and the measured size distributions of EC, organic carbon, and major inorganic ions indicate that EC-containing particles contributed 76±20% of the observed light extinction at the urban sites. Among the EC-containing particles, EC mass alone contributed 21±11% of the observed light extinction while non-EC materials on the EC particles (i.e., organic matter, ammonium sulfate, and water contributed 55±15%. At the suburban/rural locations, EC-containing particles contributed 37–48% of the measured light extinction, with EC mass contributing 4–10% and non-EC coating materials contributing the remaining light extinction. Our results suggest that EC-containing particles were important to the overall light extinction in the urban atmospheres due to their more abundant presence from vehicular emissions. The EC-containing particles in the suburban/rural locations had a reduced but still significant contribution to light extinction budget.

  13. PDMS and MWCNT – How to Obtain an Efficient and Controlled Distribution of Conductive Fillers in PDMS

    DEFF Research Database (Denmark)

    Hassonueh, S. S.; Goswami, Kaustav; Skov, Anne Ladegaard

    to their outstanding electrical and mechanical properties. However, the use of MWCNT for many new applications requires efficient processing strategies in order to result in elastomers with an efficient dispersion of the nanomaterial. If it is possible to obtain an efficient dispersion of the nanomaterial in the PDMS...... precursors the mixture should additionally be able to crosslink without interference from the nanofiller1. There are several possible pathways to obtain such dispersions, where these could be divided into two main strategies, direct mixing using processing equipment or modification of the MWCNT followed....... It is very clear that in order to obtain sufficiently effective dispersion, it is necessary to use the more efficient methods such as roll milling or speed mixing to distribute the fillers. Processing aids such as ionic liquids have been tested and found effective, though it requires higher amounts...

  14. The discrimination filters to increase the reliability of EEW association on the location using geometric distribution of triggered stations with upgrading a travel time model.

    Science.gov (United States)

    Chi, H. C.; Park, J. H.; Lim, I. S.; Seong, Y. J.

    2015-12-01

    In operation of Earthquake Early Warning System (EEWS), the alerting criteria are one of the most important parameters in optimizing acceptable warning system. During early stage of testing EEW systems from 2011 to 2013, we adapted ElarmS by UC Berkeley BSL to Korean seismic network and applied very simple criteria for event alerting with the combination of the numbers of station and magnitude. As a result of the testing we found out that the real-time test result of Earthquake Early Warning (EEW) system in Korea showed that all events located within seismic network with bigger than magnitude 3.0 were well detected. However, two events located at sea between land and island gave false results with magnitude over 4.0 related to the teleseismic waves and one event located in land gave false results with magnitude over 3.0 related to the teleseismic waves. These teleseismic-relevant false events were caused by logical co-relation during association procedure and the corresponding geometric distribution of associated stations is crescent-shaped. Seismic stations are not deployed uniformly, so the expected bias ratio varies with evaluated epicentral location. This ratio is calculated in advance and stored into database, called as TrigDB, for the discrimination of teleseismic-origin false alarm. We developed a method, so called 'TrigDB back filling', updating location with supplementary association of stations comparing triggered times between sandwiched stations which was not associated previously based on predefined criteria such as travel-time. Because EEW program assume that all events are local, teleseismic-relevant events can give more triggered stations by using back filling of the unassociated stations than the normal association. And we also developed a travel time curve (K-SEIS-1DTT2015) to reduce split event for EEWS. After applying the K-SEIS-1DTT2015 model, these teleseismic-relevant false events are reduced. As a result of these methods we could get more

  15. Detection of arcing ground fault location on a distribution network connected PV system; Hikarihatsuden renkei haidensen ni okeru koko chiryaku kukan no kenshutsuho

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M.; Iwaya, K.; Morooka, Y. [Hachinohe Institute of Technology, Aomori (Japan)

    1996-10-27

    In the near future, it is supposed that a great number of small-scale distributed power sources, such as photovoltaic power generation for general houses, will be interconnected with the ungrounded neutral distribution system in Japan. When ground fault of commercial frequency once occurs, great damage is easily guessed. This paper discusses the effect of the ground fault on the ground phase current using a 6.6 kV high-voltage model system by considering the non-linear self-inductance in the line, and by considering the non-linear relation of arcing ground fault current frequency. In the present method, the remarkable difference of series resonance frequency determined by the inductance and earth capacity between the source side and load side is utilized for the detection of high-voltage arcing ground fault location. In this method, there are some cases in which the non-linear effect obtained by measuring the inductance of sound phase including the secondary winding of transformer can not be neglected. Especially, for the actual high-voltage system, it was shown that the frequency characteristics of transformer inductance for distribution should be theoretically derived in the frequency range between 2 kHz and 6 kHz. 2 refs., 5 figs., 1 tab.

  16. An efficient distributed localisation algorithm for wireless sensor networks: based on smart reference-selection method

    CSIR Research Space (South Africa)

    Abu-Mahfouz, Adnan M

    2013-05-01

    Full Text Available of the available references to enhance their performance. However, to implement an efficient localisation algorithm for WSNs one should reconsider this assumption. This paper introduces an efficient localisation algorithm that is based on a novel smart reference-selection...

  17. Combined effects of phase-shift and power distribution on efficiency of dual-high-frequency sonochemistry.

    Science.gov (United States)

    Waldo, Nicholas B; Vecitis, Chad D

    2018-03-01

    In an effort to increase the efficiency of sonochemical reactors, this study investigates a single-source, dual-high-frequency ultrasound reactor. Experiments were conducted with a variety of piezoelectric crystals and reactor components, and for each reactor design a range of power distributions and phase shifts between the two frequencies were evaluated. Certain dual-frequency configurations produced up to a threefold increase in sonochemical efficiency, while others yeilded no improvement over a single frequency. These results led to two significant findings. First, phase-shift had a strong effect on sonochemical efficiency for both harmonic and non-harmonic frequency combinations. Second, the most efficient dual-harmonic-frequency waveforms had a single peak per half-cycle, rather than two unique peaks. If dual-frequency, single-source ultrasound reactors are to become more efficient they must be able to consistently control the phase angle of and power distribution between harmonic waves to create an optimal waveform. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Efficient Sustainable Operation Mechanism of Distributed Desktop Integration Storage Based on Virtualization with Ubiquitous Computing

    National Research Council Canada - National Science Library

    Kim, Hyun-Woo; Park, Jong; Majigsuren, Duinkhorjav; Jeong, Young-Sik

    2015-01-01

    .... Studies regarding diverse virtualization are currently in progress. These studies aim to determine ways to efficiently store and process the big data generated by the multitude of devices and services in use...

  19. Leveraging Complementary Distribution Channels for an Effective, Efficient Global Supply Chain

    Science.gov (United States)

    2007-01-01

    their strengths , the channels become complementary elements of an effective, efficient global supply chain. The Department of Defense’s inventory...leverage their individual strengths , these channels become complementary elements of an effective, efficient global supply chain. - 3 - 2. Major...commercial premium air delivery carriers such as FedEx, DHL , and UPS through blanket contracts that are all part of the WWX program. “Surface-direct” is

  20. Location and determination of steps of capacitors in shunt for distribution power lines; Localizacion y determinacion de pasos de capacitores en derivacion para lineas de distribucion

    Energy Technology Data Exchange (ETDEWEB)

    Pampin Vergara, Gabriela; Sarmiento Uruchurtu, Hector [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    A methodology is presented to determine the optimal location of the capacitor banks in shunt for distribution networks. The proposed tool allows knowing the bank type to install (fixed, disconnect able or of pass), as well as the electrical parameters of the feeder and the economic benefit that the banks of capacitors represent, with a minimum of input data. Its development in a spreadsheet allows the analysis of numerous alternatives in an easy way. The method is based on that the structure of the feeders of distribution is, generally, of radial type, with which, and by means of an iterative process, the optimal location of the capacitor banks in shunt is looked for. The type of bank is determined based of the demand, as well as the number of steps. The results of the analysis in feeders of the network of the central area are shown. [Spanish] Se presenta una metodologia para determinar la localizacion optima de los bancos de capacitores en derivacion en redes de distribucion. La herramienta propuesta permite conocer el tipo de banco a instalar (fijo, desconcectable o de paso), asi como los parametros electricos del alimentador y el beneficio economico que representan los bancos de capacitores, con un minimo de datos de entrada. Su desarrollo en una hoja de calculo permite el analisis de numerosas alternativas de manera facil. El metodo se basa en que la estructura de los alimentadores de distribucion es, por lo general, de tipo radial, con lo cual, y por medio de un proceso iterativo, se busca la localizacion optima de los bancos de capacitores en derivacion. Se determina el tipo de banco en funcion de la demanda, asi como el numero de pasos. Se muestran resultados del analisis en alimentadores de la red del area central.

  1. Efficient Integration, Validation and Troubleshooting in Multimodal Distributed Diagnostic Schemes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Qualtech Systems Inc. (QSI) proposes to develop a well defined process for integration of distributed diagnostic schemes. The process includes a set of guidelines to...

  2. On the relevance of efficient, integrated computer and network monitoring in HEP distributed online environment

    CERN Document Server

    Carvalho, D F; Delgado, V; Albert, J N; Bellas, N; Javello, J; Miere, Y; Ruffinoni, D; Smith, G

    1996-01-01

    Large Scientific Equipments are controlled by Computer System whose complexity is growing driven, on the one hand by the volume and variety of the information, its distributed nature, thhe sophistication of its trearment and, on the over hand by the fast evolution of the computer and network market. Some people call them generically Large-Scale Distributed Data Intensive Information Systems or Distributed Computer Control Systems (DCCS) for those systems dealing more with real time control. Taking advantage of (or forced by) the distributed architecture, the tasks are more and more often implemented as Client-Server applications. In this frame- work the monitoring of the computer nodes, the communications network and the applications becomes of primary importance for ensuring the safe running and guaranteed performance of the system. With the future generation of HEP experiments, such as those at the LHC in view, it is to integrate the various functions of DCCS monitoring into one general purpose Multi-layer ...

  3. More efficient approaches to the exponentiated half-logistic distribution based on record values

    National Research Council Canada - National Science Library

    Seo, Jung-In; Kang, Suk-Bok

    2016-01-01

    ... perspectives if record values have an exponentiated half-logistic distribution. In the frequentist approach, estimation methods based on pivotal quantities are proposed which require no complex computation unlike the maximum likelihood method...

  4. Probabilistic Distributed Algorithms for Energy Efficient Routing and Tracking in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Paul G. Spirakis

    2009-02-01

    Full Text Available In this work we focus on the energy efficiency challenge in wireless sensor networks, from both an on-line perspective (related to routing, as well as a network design perspective (related to tracking. We investigate a few representative, important aspects of energy efficiency: a the robust and fast data propagation b the problem of balancing the energy dissipation among all sensors in the network and c the problem of efficiently tracking moving entities in sensor networks. Our work here is a methodological survey of selected results that have already appeared in the related literature. In particular, we investigate important issues of energy optimization, like minimizing the total energy dissipation, minimizing the number of transmissions as well as balancing the energy load to prolong the system’s lifetime. We review characteristic protocols and techniques in the recent literature, including probabilistic forwarding and local optimization methods. We study the problem of localizing and tracking multiple moving targets from a network design perspective i.e. towards estimating the least possible number of sensors, their positions and operation characteristics needed to efficiently perform the tracking task. To avoid an expensive massive deployment, we try to take advantage of possible coverage overlaps over space and time, by introducing a novel combinatorial model that captures such overlaps. Under this model, we abstract the tracking network design problem by a covering combinatorial problem and then design and analyze an efficient approximate method for sensor placement and operation.

  5. Influence of pH, layer charge location and crystal thickness distribution on U(VI) sorption onto heterogeneous dioctahedral smectite

    Energy Technology Data Exchange (ETDEWEB)

    Guimarães, Vanessa [Instituto de Ciências da Terra – Porto, DGAOT, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Geobiotec. Departamento de Geociências da Universidade de Aveiro, Campo Universitário de Santiago, 3810-193 Aveiro (Portugal); Rodríguez-Castellón, Enrique; Algarra, Manuel [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga. Campus de Teatino s/n, 29071 Málaga (Spain); Rocha, Fernando [Geobiotec. Departamento de Geociências da Universidade de Aveiro, Campo Universitário de Santiago, 3810-193 Aveiro (Portugal); Bobos, Iuliu, E-mail: ibobos@fc.up.pt [Instituto de Ciências da Terra – Porto, DGAOT, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2016-11-05

    Highlights: • The UO{sub 2}{sup 2+} sorption at pH 4 and 6 on heterogeneous smectite structure. • The cation exchange process is affected by layer charge distribution. • Surface complexation and cation exchange modelling. • New binding energy components identified by X-ray photoelectron spectroscopy. - Abstract: The UO{sub 2}{sup 2+} adsorption on smectite (samples BA1, PS2 and PS3) with a heterogeneous structure was investigated at pH 4 (I = 0.02 M) and pH 6 (I = 0.2 M) in batch experiments, with the aim to evaluate the influence of pH, layer charge location and crystal thickness distribution. Mean crystal thickness distribution of smectite crystallite used in sorption experiments range from 4.8 nm (sample PS2), to 5.1 nm (sample PS3) and, to 7.4 nm (sample BA1). Smaller crystallites have higher total surface area and sorption capacity. Octahedral charge location favor higher sorption capacity. The sorption isotherms of Freundlich, Langmuir and SIPS were used to model the sorption experiments. The surface complexation and cation exchange reactions were modeled using PHREEQC-code to describe the UO{sub 2}{sup 2+} sorption on smectite. The amount of UO{sub 2}{sup 2+} adsorbed on smectite samples decreased significantly at pH 6 and higher ionic strength, where the sorption mechanism was restricted to the edge sites of smectite. Two binding energy components at 380.8 ± 0.3 and 382.2 ± 0.3 eV, assigned to hydrated UO{sub 2}{sup 2+} adsorbed by cation exchange and by inner-sphere complexation on the external sites at pH 4, were identified after the U4f{sub 7/2} peak deconvolution by X-photoelectron spectroscopy. Also, two new binding energy components at 380.3 ± 0.3 and 381.8 ± 0.3 eV assigned to ≡AlOUO{sub 2}{sup +} and ≡SiOUO{sub 2}{sup +} surface species were observed at pH 6.

  6. Influence of denitrification reactor retention time distribution (RTD) on dissolved oxygen control and nitrogen removal efficiency.

    Science.gov (United States)

    Raboni, Massimo; Gavasci, Renato; Viotti, Paolo

    2015-01-01

    Low concentrations of dissolved oxygen (DO) are usually found in biological anoxic pre-denitrification reactors, causing a reduction in nitrogen removal efficiency. Therefore, the reduction of DO in such reactors is fundamental for achieving good nutrient removal. The article shows the results of an experimental study carried out to evaluate the effect of the anoxic reactor hydrodynamic model on both residual DO concentration and nitrogen removal efficiency. In particular, two hydrodynamic models were considered: the single completely mixed reactor and a series of four reactors that resemble plug-flow behaviour. The latter prove to be more effective in oxygen consumption, allowing a lower residual DO concentration than the former. The series of reactors also achieves better specific denitrification rates and higher denitrification efficiency. Moreover, the denitrification food to microrganism (F:M) ratio (F:MDEN) demonstrates a relevant synergic action in both controlling residual DO and improving the denitrification performance.

  7. Improved harmonic suppression efficiency of single-phase APFs in distorted distribution systems

    Science.gov (United States)

    Biricik, Samet; Redif, Soydan; Khadem, Shafiuzzaman K.; Basu, Malabika

    2016-02-01

    In this study, a control method is proposed to improve the harmonic suppression efficiency of the single-phase active power filter in a distorted power system to suppress current harmonics and reactive power. The proposed method uses the self-tuning filter (STF) algorithm to process single-phase grid voltage in order to provide a uniform reference grid current, which increases the efficiency of the system. The results of the simulation study are presented to verify the effectiveness of the proposed control technique in this study.

  8. A Hardware Efficient Random Number Generator for Nonuniform Distributions with Arbitrary Precision

    Directory of Open Access Journals (Sweden)

    Christian de Schryver

    2012-01-01

    number generators is a very active research field. However, most state-of-the-art architectures are either tailored to specific distributions or use up a lot of hardware resources. At ReConFig 2010, we have presented a new design that saves up to 48% of area compared to state-of-the-art inversion-based implementation, usable for arbitrary distributions and precision. In this paper, we introduce a more flexible version together with a refined segmentation scheme that allows to further reduce the approximation error significantly. We provide a free software tool allowing users to implement their own distributions easily, and we have tested our random number generator thoroughly by statistic analysis and two application tests.

  9. Efficient kesterite solar cells with high open-circuit voltage for applications in powering distributed devices

    Science.gov (United States)

    Antunez, Priscilla D.; Bishop, Douglas M.; Luo, Yu; Haight, Richard

    2017-11-01

    Simultaneously achieving high voltage and high efficiency in thin-film solar cells is of paramount importance for real-world applications. While solar cells fabricated from the Earth-abundant kesterite absorber Cu2ZnSn(SxSe1-x)4 provide an attractive, non-toxic, energy harvesting solution, their utilization has been constrained by relatively low open-circuit voltages that limit efficiency. Increasing the sulfur content to widen the bandgap boosts the voltage, but usually at the expense of efficiency. Here, we report important progress on this fundamental problem by fabricating solar cells with high sulfur content that exhibit efficiencies up to 11.89% with open-circuit voltages as high as 670 mV. In a multistep process, fully functional solar cells are separated from their growth substrate, and a high-work-function back contact is subsequently deposited. With this approach, we fabricated a series-connected device that produces 5.7 V under 1 Sun illumination and 2 V under low lighting conditions, below 10-3 Suns.

  10. CFD modeling to improve safe and efficient distribution of chlorine dioxide gas for packaging fresh produce

    Science.gov (United States)

    The efficiency of the packaging system in inactivating food borne pathogens and prolonging the shelf life of fresh-cut produce is influenced by the design of the package apart from material and atmospheric conditions. Three different designs were considered to determine a specific package design ens...

  11. How is water-use efficiency of terrestrial ecosystems distributed and changing on Earth?

    DEFF Research Database (Denmark)

    Tang, Xuguang; Li, Hengpeng; Desai, Ankur R.

    2015-01-01

    A better understanding of ecosystem water-use efficiency (WUE) will help us improve ecosystem management for mitigation as well as adaption to global hydrological change. Here, long-term flux tower observations of productivity and evapotranspiration allow us to detect a consistent latitudinal tre...

  12. Mesquite root distribution and water use efficiency in response to long-term soil moisture manipulations

    Science.gov (United States)

    R. J. Ansley; T. W. Boutton; P. W. Jacoby

    2007-01-01

    This study quantified honey mesquite (Prosopis glandulosa) root growth and water use efficiency following chronic soil drought or wetness on a clay loam site in north Texas. Root systems of mature trees were containerized with barriers inserted into the soil. Soil moisture within containers was manipulated with irrigation (Irrigated) or rain...

  13. An efficient Markov chain Monte Carlo method for distributions with intractable normalising constants

    DEFF Research Database (Denmark)

    Møller, Jesper; Pettitt, A. N.; Reeves, R.

    2006-01-01

    Maximum likelihood parameter estimation and sampling from Bayesian posterior distributions are problematic when the probability density for the parameter of interest involves an intractable normalising constant which is also a function of that parameter. In this paper, an auxiliary variable method...... is presented which requires only that independent samples can be drawn from the unnormalised density at any particular parameter value. The proposal distribution is constructed so that the normalising constant cancels from the Metropolis–Hastings ratio. The method is illustrated by producing posterior samples...

  14. Increasing power distribution mains efficiency through new mains configurations; Effizienzsteigerung im Verteilnetz durch neue Netzkonfigurationen

    Energy Technology Data Exchange (ETDEWEB)

    Hoeckel, M.

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) summarises the findings of a study that sought to find new approaches to minimise distribution losses in medium and low voltage power grids. Options examined included the optimisation of distribution-station density, increasing the nominal voltage of the low-voltage grid and the implementation of decentralised energy production. Data from real-life grids were used together with simulations to analyse possible solutions. The conclusions of these analyses are presented and discussed. In addition, qualitative and detailed examinations were made concerning grid quality factors such as availability and voltage stability.

  15. Efficient magnetohydrodynamic simulations on distributed multi-GPU systems using a novel GPU Direct-MPI hybrid approach

    Science.gov (United States)

    Wong, Un-Hong; Aoki, Takayuki; Wong, Hon-Cheng

    2014-07-01

    Modern graphics processing units (GPUs) have been widely utilized in magnetohydrodynamic (MHD) simulations in recent years. Due to the limited memory of a single GPU, distributed multi-GPU systems are needed to be explored for large-scale MHD simulations. However, the data transfer between GPUs bottlenecks the efficiency of the simulations on such systems. In this paper we propose a novel GPU Direct-MPI hybrid approach to address this problem for overall performance enhancement. Our approach consists of two strategies: (1) We exploit GPU Direct 2.0 to speedup the data transfers between multiple GPUs in a single node and reduce the total number of message passing interface (MPI) communications; (2) We design Compute Unified Device Architecture (CUDA) kernels instead of using memory copy to speedup the fragmented data exchange in the three-dimensional (3D) decomposition. 3D decomposition is usually not preferable for distributed multi-GPU systems due to its low efficiency of the fragmented data exchange. Our approach has made a breakthrough to make 3D decomposition available on distributed multi-GPU systems. As a result, it can reduce the memory usage and computation time of each partition of the computational domain. Experiment results show twice the FLOPS comparing to common 2D decomposition MPI-only implementation method. The proposed approach has been developed in an efficient implementation for MHD simulations on distributed multi-GPU systems, called MGPU-MHD code. The code realizes the GPU parallelization of a total variation diminishing (TVD) algorithm for solving the multidimensional ideal MHD equations, extending our work from single GPU computation (Wong et al., 2011) to multiple GPUs. Numerical tests and performance measurements are conducted on the TSUBAME 2.0 supercomputer at the Tokyo Institute of Technology. Our code achieves 2 TFLOPS in double precision for the problem with 12003 grid points using 216 GPUs.

  16. CompatPM: enabling energy efficient multimedia workloads for distributed mobile platforms

    Science.gov (United States)

    Nathuji, Ripal; O'Hara, Keith J.; Schwan, Karsten; Balch, Tucker

    2007-01-01

    The computation and communication abilities of modern platforms are enabling increasingly capable cooperative distributed mobile systems. An example is distributed multimedia processing of sensor data in robots deployed for search and rescue, where a system manager can exploit the application's cooperative nature to optimize the distribution of roles and tasks in order to successfully accomplish the mission. Because of limited battery capacities, a critical task a manager must perform is online energy management. While support for power management has become common for the components that populate mobile platforms, what is lacking is integration and explicit coordination across the different management actions performed in a variety of system layers. This papers develops an integration approach for distributed multimedia applications, where a global manager specifies both a power operating point and a workload for a node to execute. Surprisingly, when jointly considering power and QoS, experimental evaluations show that using a simple deadline-driven approach to assigning frequencies can be non-optimal. These trends are further affected by certain characteristics of underlying power management mechanisms, which in our research, are identified as groupings that classify component power management as "compatible" (VFC) or "incompatible" (VFI) with voltage and frequency scaling. We build on these findings to develop CompatPM, a vertically integrated control strategy for power management in distributed mobile systems. Experimental evaluations of CompatPM indicate average energy improvements of 8% when platform resources are managed jointly rather than independently, demonstrating that previous attempts to maximize battery life by simply minimizing frequency are inappropriate from a platform-level perspective.

  17. Xenobiotic removal efficiencies in wastewater treatment plants: residence time distributions as a guiding principle for sampling strategies.

    Science.gov (United States)

    Majewsky, Marius; Gallé, Tom; Bayerle, Michael; Goel, Rajeev; Fischer, Klaus; Vanrolleghem, Peter A

    2011-11-15

    The effect of mixing regimes and residence time distribution (RTD) on solute transport in wastewater treatment plants (WWTPs) is well understood in environmental engineering. Nevertheless, it is frequently neglected in sampling design and data analysis for the investigation of polar xenobiotic removal efficiencies in WWTPs. Most studies on the latter use 24-h composite samples in influent and effluent. The effluent sampling period is often shifted by the mean hydraulic retention time assuming that this allows a total coverage of the influent load. However, this assumption disregards mixing regime characteristics as well as flow and concentration variability in evaluating xenobiotic removal performances and may consequently lead to biased estimates or even negative elimination efficiencies. The present study aims at developing a modeling approach to estimate xenobiotic removal efficiencies from monitoring data taking the hydraulic RTD in WWTPs into consideration. For this purpose, completely mixed tanks-in-series were applied to address hydraulic mixing regimes in a Luxembourg WWTP. Hydraulic calibration for this WWTP was performed using wastewater conductivity as a tracer. The RTD mixing approach was coupled with first-order biodegradation kinetics for xenobiotics covering three classes of biodegradability during aerobic treatment. Model simulations showed that a daily influent load is distributed over more than one day in the effluent. A 24-h sampling period with an optimal time offset between influent and effluent covers less than the half of the influent load in a dry weather scenario. According to RTD calculations, an optimized sampling strategy covering four consecutive measuring days in the influent would be necessary to estimate the full-scale elimination efficiencies with sufficient accuracy. Daily variations of influent flow and concentrations can substantially affect the reliability of these sampling results. Commonly reported negative removal

  18. Analysis and distributed control of power flow in DC microgrids to improve system efficiency

    DEFF Research Database (Denmark)

    Chen, Fang; Burgos, Rolando; Boroyevich, Dushan

    2016-01-01

    . An enhanced current regulator is adopted to guarantee the accurate load sharing considering the impact from sensor error and line resistance. A tie line power flow control method is proposed to regulate the tie line power and increase the system efficiency at light load. All the considered methods only need......DC Microgrid attains popularity in integrating renewable energy sources and batteries. It also has the potential to achieve higher efficiency than ac power grid under the condition of optimized power flow. In this paper, a general dc microgrid is modeled based on a cluster of general dc nodes......, which includes constant power renewables generation, droop-controlled voltage source and different kinds of load. Then the dc power flow is solved for optimization. A voltage restoration method based on consensus communication is used to restore the voltage deviation from droop characteristic...

  19. Modeling of non-linear CHP efficiency curves in distributed energy systems

    DEFF Research Database (Denmark)

    Milan, Christian; Stadler, Michael; Cardoso, Gonçalo

    2015-01-01

    operation has mainly been found important for fuel cell units. The micro-turbine is found almost exclusively in full load, thus rendering the application of the new approaches for this technology unnecessary for the considered unit sizes and building types. The approach using binary variables was the most...... for these technologies, detailed system models are needed. These models are often formulated as linear programming problems to keep computational costs and complexity in a reasonable range. However, CHP systems involve variations of the efficiency for large nameplate capacity ranges and in case of part load operation...... approaches are formulated using binary and Special-Ordered-Set (SOS) variables. Both suggestions have been implemented into the optimization model DER–CAM to simulate investment decisions of CHP micro-turbines and CHP fuel cells with variable efficiencies. The approaches have further been applied...

  20. Linear Distributed GaN MMIC Power Amplifier with Improved Power-added Efficiency

    Science.gov (United States)

    2017-03-01

    QPSK LTE waveform, the ACPR1improved by ~10 dBc at average output power of 23 dBm, without digital pre-distortion. Keywords: GaN, linear amplifiers...wideband amplifier, OIP3, LTE Introduction RF communications with spectral efficiency utilizes complex modulation schemes that require amplifier...QPSK) long-term evolution ( LTE ) waveforms also improved by ~10 dBc at an average linear power of 23 dBm. Figure 1. (a) A schematic drawing of

  1. A communication efficient and scalable distributed data mining for the astronomical data

    Science.gov (United States)

    Govada, A.; Sahay, S. K.

    2016-07-01

    In 2020, ∼60PB of archived data will be accessible to the astronomers. But to analyze such a paramount data will be a challenging task. This is basically due to the computational model used to download the data from complex geographically distributed archives to a central site and then analyzing it in the local systems. Because the data has to be downloaded to the central site, the network BW limitation will be a hindrance for the scientific discoveries. Also analyzing this PB-scale on local machines in a centralized manner is challenging. In this, virtual observatory is a step towards this problem, however, it does not provide the data mining model (Zhang et al., 2004). Adding the distributed data mining layer to the VO can be the solution in which the knowledge can be downloaded by the astronomers instead the raw data and thereafter astronomers can either reconstruct the data back from the downloaded knowledge or use the knowledge directly for further analysis. Therefore, in this paper, we present Distributed Load Balancing Principal Component Analysis for optimally distributing the computation among the available nodes to minimize the transmission cost and downloading cost for the end user. The experimental analysis is done with Fundamental Plane (FP) data, Gadotti data and complex Mfeat data. In terms of transmission cost, our approach performs better than Qi et al. and Yue et al. The analysis shows that with the complex Mfeat data ∼90% downloading cost can be reduced for the end user with the negligible loss in accuracy.

  2. Space-time Coordinated Distributed Sensing Algorithms for Resource Efficient Narrowband Target Localization and Tracking

    OpenAIRE

    Shashi Phoha; John Koch; Eric Grele; Christopher Griffin; Bharat Madan

    2005-01-01

    Distributed sensing has been used for enhancing signal to noise ratios for space-time localization and tracking of remote objects using phased array antennas, sonar, and radio signals. The use of these technologies in identifying mobile targets in a field, emitting acoustic signals, using a network of low-cost narrow band acoustic micro-sensing devices randomly dispersed over the region of interest, presents unique challenges. The effects of wind, turbulence, and temperature gradients and oth...

  3. Reduced Efficiency of Chlorine Disinfection of Naegleria fowleri in a Drinking Water Distribution Biofilm.

    Science.gov (United States)

    Miller, Haylea C; Wylie, Jason; Dejean, Guillaume; Kaksonen, Anna H; Sutton, David; Braun, Kalan; Puzon, Geoffrey J

    2015-09-15

    Naegleria fowleri associated with biofilm and biological demand water (organic matter suspended in water that consumes disinfectants) sourced from operational drinking water distribution systems (DWDSs) had significantly increased resistance to chlorine disinfection. N. fowleri survived intermittent chlorine dosing of 0.6 mg/L for 7 days in a mixed biofilm from field and laboratory-cultured Escherichia coli strains. However, N. fowleri associated with an attached drinking water distribution biofilm survived more than 30 times (20 mg/L for 3 h) the recommended concentration of chlorine for drinking water. N. fowleri showed considerably more resistance to chlorine when associated with a real field biofilm compared to the mixed laboratory biofilm. This increased resistance is likely due to not only the consumption of disinfectants by the biofilm and the reduced disinfectant penetration into the biofilm but also the composition and microbial community of the biofilm itself. The increased diversity of the field biofilm community likely increased N. fowleri's resistance to chlorine disinfection compared to that of the laboratory-cultured biofilm. Previous research has been conducted in only laboratory scale models of DWDSs and laboratory-cultured biofilms. To the best of our knowledge, this is the first study demonstrating how N. fowleri can persist in a field drinking water distribution biofilm despite chlorination.

  4. Root iron uptake efficiency of Ulmus laevis and U. minor and their distribution in soils of the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Martin eVenturas

    2014-03-01

    Full Text Available The calcifuge and calcicole character of wild plants has been related to nutrient availability shortages, including iron (Fe-deficiency. Surprisingly, just a few studies examined the relation between root Fe uptake and plant distribution in different soil types. We assessed the root Fe acquisition efficiency of two Ulmus species with calcareous (U. minor and siliceous (U. laevis soil distribution patterns in the Iberian Peninsula. Seedlings of both elm species were grown hydroponically with different Fe concentrations during six weeks. Plant physiological responses to Fe-limiting conditions were evaluated as were the ferric reductase activity and proton (H+ extrusion capacity of the roots. Iron deprived elm seedlings of both species were stunted and suffered severe Fe-chlorosis symptoms. After Fe re-supply leaf chlorophyll concentrations rose according to species-dependent patterns. While U. minor leaves and seedlings re-greened evenly, U. laevis did so along the nerves of new growing leaves. Ulmus minor had a higher root ferric reductase activity and H+-extrusion capability than U. laevis and maintained a better nutrient balance when grown under Fe-limiting conditions. The two elm species were found to have different iron acquisition efficiencies which may be related to their natural distribution in calcareous and siliceous soils of the Iberian Peninsula.

  5. Robustness in facility location

    OpenAIRE

    Van Lokven, Sander W.M.

    2009-01-01

    Facility location concerns the placement of facilities, for various objectives, by use of mathematical models and solution procedures. Almost all facility location models that can be found in literature are based on minimizing costs or maximizing cover, to cover as much demand as possible. These models are quite efficient for finding an optimal location for a new facility for a particular data set, which is considered to be constant and known in advance. In a real world situation, input da...

  6. Efficient workload management in geographically distributed data centers leveraging autoregressive models

    Science.gov (United States)

    Altomare, Albino; Cesario, Eugenio; Mastroianni, Carlo

    2016-10-01

    The opportunity of using Cloud resources on a pay-as-you-go basis and the availability of powerful data centers and high bandwidth connections are speeding up the success and popularity of Cloud systems, which is making on-demand computing a common practice for enterprises and scientific communities. The reasons for this success include natural business distribution, the need for high availability and disaster tolerance, the sheer size of their computational infrastructure, and/or the desire to provide uniform access times to the infrastructure from widely distributed client sites. Nevertheless, the expansion of large data centers is resulting in a huge rise of electrical power consumed by hardware facilities and cooling systems. The geographical distribution of data centers is becoming an opportunity: the variability of electricity prices, environmental conditions and client requests, both from site to site and with time, makes it possible to intelligently and dynamically (re)distribute the computational workload and achieve as diverse business goals as: the reduction of costs, energy consumption and carbon emissions, the satisfaction of performance constraints, the adherence to Service Level Agreement established with users, etc. This paper proposes an approach that helps to achieve the business goals established by the data center administrators. The workload distribution is driven by a fitness function, evaluated for each data center, which weighs some key parameters related to business objectives, among which, the price of electricity, the carbon emission rate, the balance of load among the data centers etc. For example, the energy costs can be reduced by using a "follow the moon" approach, e.g. by migrating the workload to data centers where the price of electricity is lower at that time. Our approach uses data about historical usage of the data centers and data about environmental conditions to predict, with the help of regressive models, the values of the

  7. Decision factors affecting transmission and distribution efficiency improvements by Northwest electric utilities

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, P.L.; Darwin, R.F.

    1986-01-01

    The principal objective of this report was to assess and document the attitude of Northwest electric utilities toward possible BPA conservation acquisition programs that may provide incentive(s) to reduce losses on T and D lines. Secondary objectives were to examine existing incentives for making such improvements, to categorize prior T and D efficiency improvements, and to examine factors affecting the decision-making process for system improvements. Much of the information presented in the report is derived from a survey administered during personal interviews at 29 Northwest electric utilities between November 1984 and January 1985.

  8. NON-INVASIVE DETERMINATION OF THE LOCATION AND DISTRIBUTION OF FREE-PHASE DENSE NONAQUEOUS PHASE LIQUIDS (DNAPL) BY SEISMIC REFLECTION TECHNIQUES

    Energy Technology Data Exchange (ETDEWEB)

    Michael G. Waddell; William J. Domoracki; Tom J. Temples; Jerome Eyer

    2001-05-01

    The Earth Sciences and Resources Institute, University of South Carolina is conducting a 14 month proof of concept study to determine the location and distribution of subsurface Dense Nonaqueous Phase Liquid (DNAPL) carbon tetrachloride (CCl{sub 4}) contamination at the 216-Z-9 crib, 200 West area, Department of Energy (DOE) Hanford Site, Washington by use of two-dimensional high resolution seismic reflection surveys and borehole geophysical data. The study makes use of recent advances in seismic reflection amplitude versus offset (AVO) technology to directly detect the presence of subsurface DNAPL. The techniques proposed are a noninvasive means towards site characterization and direct free-phase DNAPL detection. This report covers the results of Task 3 and change of scope of Tasks 4-6. Task 1 contains site evaluation and seismic modeling studies. The site evaluation consists of identifying and collecting preexisting geological and geophysical information regarding subsurface structure and the presence and quantity of DNAPL. The seismic modeling studies were undertaken to determine the likelihood that an AVO response exists and its probable manifestation. Task 2 is the design and acquisition of 2-D seismic reflection data designed to image areas of probable high concentration of DNAPL. Task 3 is the processing and interpretation of the 2-D data. Task 4, 5, and 6 were designing, acquiring, processing, and interpretation of a three dimensional seismic survey (3D) at the Z-9 crib area at 200 west area, Hanford.

  9. Diode laser for endodontic treatment: investigations of light distribution and disinfection efficiency

    Science.gov (United States)

    Stock, Karl; Graser, Rainer; Udart, Martin; Kienle, Alwin; Hibst, Raimund

    2011-03-01

    Diode lasers are used in dentistry mainly for oral surgery and disinfection of root canals in endodontic treatment. The purpose of this study was to investigate and to improve the laser induced bacteria inactivation in endodontic treatment. An essential prerequisite of the optimization of the irradiation process and device is the knowledge about the determinative factors of bacteria killing: light intensity? light dosis? temperature? In order to find out whether high power NIR laser bacterial killing is caused by a photochemical or a photothermal process we heated bacteria suspensions of E. coli K12 by a water bath and by a diode laser (940 nm) with the same temporal temperature course. Furthermore, bacteria suspensions were irradiated while the temperature was fixed by ice water. Killing of bacteria was measured via fluorescence labeling. In order to optimize the irradiation of the root canal, we designed special fiber tips with radial light emission characteristic by optical ray tracing simulations. Also, we calculated the resulting light distribution in dentin by voxelbased Monte Carlo simulations. Furthermore, we irradiated root canals of extracted human teeth using different fiber tip geometries and measured the resulting light and heat distribution by CCD-camera and thermography. Comparison of killing rates between laser and water based heating shows no significant differences, and irradiation of ice cooled suspensions has no substantial killing effect. Thus, the most important parameter for bacterial killing is the maximum temperature. Irradiation of root canals using fiber tips with radial light emission results in a more defined irradiated area with minor irradiation of the apex and higher intensity and therefore higher temperature increase on root canal surface. In conclusion, our experiments show that at least for E. coli bacteria inactivation by NIR laser irradiation is solely based on a thermal process and that heat distribution in root canal can be

  10. Impact of the spatial distribution of morphological pattern on the efficiency of electrocatalytic gas evolving reactions

    Directory of Open Access Journals (Sweden)

    Žerađanin Aleksandar R.

    2014-01-01

    Full Text Available The efficiency of electrocatalytic gas evolving reactions (hydrogen, chlorine and oxygen evolution is a key challenge for the important industrial processes, such as chlor-alkali electrolysis or water electrolysis. Central issue for the aforementioned electrocatalytic processes is huge power consumption. Experimental results accumulated in the past, as well as some predictive models ("volcano" plots indicate that altering the nature of the electrode material cannot significantly increase the activity of mentioned reactions. Consequently, it is necessary to find a qualitatively different strategy for improving the energy efficiency of electrocatalytic gas evolving reactions. Usually disregarded fact is that the gas evolution is an oscillatory phenomenon. Given the oscillatory behavior, a key parameter of macrokinetics of gas electrode is the frequency of gas-bubble detachment. Bearing in mind that the gas evolution greatly depends on the surface morphology, a methodology is proposed that establishes a rational link between the morphological pattern of electrode with electrode activity and stability. Characterization was performed using advanced analytical tools. Frequency of gas-bubble detachment is obtained in the configuration of scanning electrochemical microscopy (SECM while the corrosion stability is analyzed using miniaturized scanning flow electrochemical cell connected to the mass spectrometer (SFC-ICPMS.

  11. Using Perturbed Underdamped Langevin Dynamics to Efficiently Sample from Probability Distributions

    Science.gov (United States)

    Duncan, A. B.; Nüsken, N.; Pavliotis, G. A.

    2017-12-01

    In this paper we introduce and analyse Langevin samplers that consist of perturbations of the standard underdamped Langevin dynamics. The perturbed dynamics is such that its invariant measure is the same as that of the unperturbed dynamics. We show that appropriate choices of the perturbations can lead to samplers that have improved properties, at least in terms of reducing the asymptotic variance. We present a detailed analysis of the new Langevin sampler for Gaussian target distributions. Our theoretical results are supported by numerical experiments with non-Gaussian target measures.

  12. Electric co-heating in the ASHRAE standard method of test for thermal distribution efficiency: Test results on two New York State homes

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W.; Krajewski, R.F.; Strasser, J.J.

    1995-10-01

    Electric co-heating tests on two single-family homes with forced-air heating systems were carried out in March 1995. The goal of these tests was to evaluate procedures being considered for incorporation in a Standard Method of Test for thermal distribution system efficiency now being developed by ASHRAE. Thermal distribution systems are the ductwork, piping, or other means used to transport heat or cooling effect from the building equipment that produces this thermal energy to the spaces in which it is used. Furthering the project goal, the first objective of the tests was to evaluate electric co-heating as a means of measuring system efficiency. The second objective was to investigate procedures for obtaining the distribution efficiency, using system efficiency as a base. Distribution efficiencies of 0.63 and 0.70 were obtained for the two houses.

  13. Effects of kaolin application on light absorption and distribution, radiation use efficiency and photosynthesis of almond and walnut canopies.

    Science.gov (United States)

    Rosati, Adolfo; Metcalf, Samuel G; Buchner, Richard P; Fulton, Allan E; Lampinen, Bruce D

    2007-02-01

    Kaolin applied as a suspension to plant canopies forms a film on leaves that increases reflection and reduces absorption of light. Photosynthesis of individual leaves is decreased while the photosynthesis of the whole canopy remains unaffected or even increases. This may result from a better distribution of light within the canopy following kaolin application, but this explanation has not been tested. The objective of this work was to study the effects of kaolin application on light distribution and absorption within tree canopies and, ultimately, on canopy photosynthesis and radiation use efficiency. Photosynthetically active radiation (PAR) incident on individual leaves within the canopy of almond (Prunus dulcis) and walnut (Juglans regia) trees was measured before and after kaolin application in order to study PAR distribution within the canopy. The PAR incident on, and reflected and transmitted by, the canopy was measured on the same day for kaolin-sprayed and control trees in order to calculate canopy PAR absorption. These data were then used to model canopy photosynthesis and radiation use efficiency by a simple method proposed in previous work, based on the photosynthetic response to incident PAR of a top-canopy leaf. Kaolin increased incident PAR on surfaces of inner-canopy leaves, although there was an estimated 20 % loss in PAR reaching the photosynthetic apparatus, due to increased reflection. Assuming a 20 % loss of PAR, modelled photosynthesis and photosynthetic radiation use efficiency (PRUE) of kaolin-coated leaves decreased by only 6.3 %. This was due to (1) more beneficial PAR distribution within the kaolin-sprayed canopy, and (2) with decreasing PAR, leaf photosynthesis decreases less than proportionally, due to the curvature of the photosynthesis response-curve to PAR. The relatively small loss in canopy PRUE (per unit of incident PAR), coupled with the increased incident PAR on the leaf surface on inner-canopy leaves, resulted in an estimated

  14. Highly efficient high power single-mode fiber amplifier utilizing the distributed mode filtering bandgap rod fiber

    DEFF Research Database (Denmark)

    Laurila, Marko; Alkeskjold, Thomas T.; Jørgensen, Mette Marie

    2012-01-01

    We report on an ytterbium doped single mode distributed mode filtering rod fiber in an amplifier configuration delivering high average output power, up to 292 watts, using a mode-locked 30ps source at 1032nm with good power conversion efficiency. We study the modal stability of the output beam...... at high average output power levels and demonstrate a 44% power improvement before the threshold-like onset of mode instabilities by operating the rod fiber in a leaky waveguide regime. We investigate the guiding dynamics of the rod fiber and explain the improved performance by thermally induced...

  15. The SmartOR: a distributed sensor network to improve operating room efficiency.

    Science.gov (United States)

    Huang, Albert Y; Joerger, Guillaume; Fikfak, Vid; Salmon, Remi; Dunkin, Brian J; Bass, Barbara L; Garbey, Marc

    2017-02-24

    Despite the significant expense of OR time, best practice achieves only 70% efficiency. Compounding this problem is a lack of real-time data. Most current OR utilization programs require manual data entry. Automated systems require installation and maintenance of expensive tracking hardware throughout the institution. This study developed an inexpensive, automated OR utilization system and analyzed data from multiple operating rooms. OR activity was deconstructed into four room states. A sensor network was then developed to automatically capture these states using only three sensors, a local wireless network, and a data capture computer. Two systems were then installed into two ORs, recordings captured 24/7. The SmartOR recorded the following events: any room activity, patient entry/exit time, anesthesia time, laparoscopy time, room turnover time, and time of preoperative patient identification by the surgeon. From November 2014 to December 2015, data on 1003 cases were collected. The mean turnover time was 36 min, and 38% of cases met the institutional goal of ≤30 min. Data analysis also identified outlier cases (>1 SD from mean) in the domains of time from patient entry into the OR to intubation (11% of cases) and time from extubation to patient exiting the OR (11% of cases). Time from surgeon identification of patient to scheduled procedure start time was 11 min (institution bylaws require 20 min before scheduled start time), yet OR teams required 22 min on average to bring a patient into the room after surgeon identification. The SmartOR automatically and reliably captures data on OR room state and, in real time, identifies outlier cases that may be examined closer to improve efficiency. As no manual entry is required, the data are indisputable and allow OR teams to maintain a patient-centric focus.

  16. Modern Energy Markets Real-Time Pricing, Renewable Resources and Efficient Distribution

    CERN Document Server

    Kopsakangas-Savolainen, Maria

    2012-01-01

    Energy has moved to the forefront in terms of societal and economic development. Modern Energy Markets is a comprehensive, economically oriented, exploration of modern electricity networks from production and distribution to deregulation and liberalization processes. Updating previous work by the authors, different aspects are considered resulting in a complete and detailed picture of  the systems and characteristics of modern electricity markets. Modern Energy Markets provides clear detail whilst encompassing a broad scope of topics and includes: •A method to model energy production systems including the main characteristics of future demand side management, •Different applications of this model in nuclear and renewable energy scenarios, •An analysis of Real-Time Pricing of electricity and its potential effects across the market, and, •A discussion of the need for regulation in an easily monopolized industry. Engineering and Economics students alike will find that Modern Energy Markets is a succinct...

  17. Distributed Arithmetic for Efficient Base-Band Processing in Real-Time GNSS Software Receivers

    Directory of Open Access Journals (Sweden)

    Grégoire Waelchli

    2010-01-01

    Full Text Available The growing market of GNSS capable mobile devices is driving the interest of GNSS software solutions, as they can share many system resources (processor, memory, reducing both the size and the cost of their integration. Indeed, with the increasing performance of modern processors, it becomes now feasible to implement in software a multichannel GNSS receiver operating in real time. However, a major issue with this approach is the large computing resources required for the base-band processing, in particular for the correlation operations. Therefore, new algorithms need to be developed in order to reduce the overall complexity of the receiver architecture. Towards that aim, this paper first introduces the challenges of the software implementation of a GPS receiver, with a main focus given to the base-band processing and correlation operations. It then describes the already existing solutions and, from this, introduces a new algorithm based on distributed arithmetic.

  18. Dynamic Allocation and Efficient Distribution of Data Among Multiple Clouds Using Network Coding

    DEFF Research Database (Denmark)

    Sipos, Marton A.; Fitzek, Frank; Roetter, Daniel Enrique Lucani

    2014-01-01

    of random linear network coding to exploit multiple commercially available cloud storage providers simultaneously with the possibility to constantly adapt to changing cloud performance in order to optimize data retrieval times. The main contribution of this paper is a new data distribution mechanisms...... that cleverly stores and moves data among different clouds in order to optimize performance. Furthermore, we investigate the trade-offs among storage space, reliability and data retrieval speed for our proposed scheme. By means of real-world implementation and measurements using well-known and publicly...... accessible cloud service providers, we can show close to 9x less network use for the adaptation compared to more conventional dense recoding approaches, while maintaining similar download time performance and the same reliability....

  19. The Efficiency of the Regulation for Horizontal Mergers Among Electricity Distribution Operators in Norway

    DEFF Research Database (Denmark)

    Agrell, Per J.; Bogetoft, Peter; Gammeltvedt, Thor Erik

    2015-01-01

    Merger analysis is usually drawing on concepts derived from competitive horizontal markets, such as market concentration, predatory foreclosure and economies of scale in marketing. In evaluating horizontal mergers among energy network operators, regulators must use different tools to evaluate...... the attractiveness of mergers. Norway is one country having implemented an ex ante regulation for mergers among electricity distribution operators (DSOs). We investigate whether the actual mergers of Norwegian DSOs in the period 1995-2004 can be rationalized as cost saving exercises or whether they should...... be interpreted in other ways. We use Data Envelopment Analysis (DEA) to estimate the potential cost savings from mergers ex ante, and we decompose the gains into gains from learning best practice and from improving economies of scale and scope. Moreover, we compare the sources of post merger performance...

  20. Gene Locater

    DEFF Research Database (Denmark)

    Anwar, Muhammad Zohaib; Sehar, Anoosha; Rehman, Inayat-Ur

    2012-01-01

    UNLABELLED: Locating genes on a chromosome is important for understanding the gene function and its linkage and recombination. Knowledge of gene positions on chromosomes is necessary for annotation. The study is essential for disease genetics and genomics, among other aspects. Currently available...... software's for calculating recombination frequency is mostly limited to the range and flexibility of this type of analysis. GENE LOCATER is a fully customizable program for calculating recombination frequency, written in JAVA. Through an easy-to-use interface, GENE LOCATOR allows users a high degree...

  1. The efficient market hypothesis of brazilian capital market, 2000-2010: an event study of distribution of dividends

    Directory of Open Access Journals (Sweden)

    Daniel Moreira Carvalho

    2013-11-01

    Full Text Available In the semi-strong form of the Efficient Markets Hypothesis - EMH, developed by Fama (1970, 1991, the prices reflect both the past and any information disclosed by companies, making impossible to an investor to get abnormal returns consistently, based on this type of information. In this paper we analyze the price behavior of common shares of 87 listed companies in the BM&FBovespa, in the announcements of 452 events of dividend distribution, occurred between January 2000 and September 2010, in order to identify the EMH in semi-strong form of Brazilian capital market. We used an event study, which evaluates abnormal returns of stocks relative to the market return (Ibovespa. The analysis of the abnormal return in the event window (10 days before and after the dividend distribution announcement showed an upward trend, with significant positive abnormal returns on days t-5, t-3, and t-1 to t+1. The results go in the direction of other studies of national literature and contribute to attest that the Brazilian capital market lacks the semi-strong form of informational efficiency.

  2. Highly Efficient Lead Distribution by Magnetic Sewage Sludge Biochar: Sorption Mechanisms and Bench Applications.

    Science.gov (United States)

    Ifthikar, Jerosha; Wang, Jia; Wang, Qiliang; Wang, Ting; Wang, Huabin; Khan, Aimal; Jawad, Ali; Sun, Tingting; Jiao, Xiang; Chen, Zhuqi

    2017-08-01

    Highly efficient magnetic sewage sludge biochar (MSSBC) discloses feasible fabrication process with lower production cost, superior adsorption capacity, usage of waste sewage sludge as resource, selected by external magnetic field and exceptional regeneration property. 2gL-1 MSSBC exhibited a high adsorption capacity of 249.00mgg-1 in 200ppmPb(II) and the lead-MSSBC equilibrium was achieved within one hour, owing to the existence of the copious active sites. The adsorption kinetics was well described by the pseudo-second-order model while the adsorption isotherm could be fitted by Langmuir model. Mechanism study demonstrated the adsorption involved electrostatic attraction, ion exchange, inner-sphere complexation and formation of co-precipitates at the surface of MSSBC. Additionally, adsorption performance maintained remarkable in a broad pH window. These outcomes demonstrated the promising waste resource utilization by a feasible approach that turns the solid waste of sewage sludge into biochar adsorbent with auspicious applications in elimination of Pb(II) from wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Programmatic implications of implementing the relational algebraic capacitated location (RACL algorithm outcomes on the allocation of laboratory sites, test volumes, platform distribution and space requirements

    Directory of Open Access Journals (Sweden)

    Naseem Cassim

    2017-02-01

    Full Text Available Introduction: CD4 testing in South Africa is based on an integrated tiered service delivery model that matches testing demand with capacity. The National Health Laboratory Service has predominantly implemented laboratory-based CD4 testing. Coverage gaps, over-/under-capacitation and optimal placement of point-of-care (POC testing sites need investigation.Objectives: We assessed the impact of relational algebraic capacitated location (RACL algorithm outcomes on the allocation of laboratory and POC testing sites.Methods: The RACL algorithm was developed to allocate laboratories and POC sites to ensure coverage using a set coverage approach for a defined travel time (T. The algorithm was repeated for three scenarios (A: T = 4; B: T = 3; C: T = 2 hours. Drive times for a representative sample of health facility clusters were used to approximate T. Outcomes included allocation of testing sites, Euclidian distances and test volumes. Additional analysis included platform distribution and space requirement assessment. Scenarios were reported as fusion table maps.Results: Scenario A would offer a fully-centralised approach with 15 CD4 laboratories without any POC testing. A significant increase in volumes would result in a four-fold increase at busier laboratories. CD4 laboratories would increase to 41 in scenario B and 61 in scenario C. POC testing would be offered at two sites in scenario B and 20 sites in scenario C.Conclusion: The RACL algorithm provides an objective methodology to address coverage gaps through the allocation of CD4 laboratories and POC sites for a given T. The algorithm outcomes need to be assessed in the context of local conditions.

  4. Programmatic implications of implementing the relational algebraic capacitated location (RACL algorithm outcomes on the allocation of laboratory sites, test volumes, platform distribution and space requirements

    Directory of Open Access Journals (Sweden)

    Naseem Cassim

    2017-02-01

    Full Text Available Introduction: CD4 testing in South Africa is based on an integrated tiered service delivery model that matches testing demand with capacity. The National Health Laboratory Service has predominantly implemented laboratory-based CD4 testing. Coverage gaps, over-/under-capacitation and optimal placement of point-of-care (POC testing sites need investigation. Objectives: We assessed the impact of relational algebraic capacitated location (RACL algorithm outcomes on the allocation of laboratory and POC testing sites. Methods: The RACL algorithm was developed to allocate laboratories and POC sites to ensure coverage using a set coverage approach for a defined travel time (T. The algorithm was repeated for three scenarios (A: T = 4; B: T = 3; C: T = 2 hours. Drive times for a representative sample of health facility clusters were used to approximate T. Outcomes included allocation of testing sites, Euclidian distances and test volumes. Additional analysis included platform distribution and space requirement assessment. Scenarios were reported as fusion table maps. Results: Scenario A would offer a fully-centralised approach with 15 CD4 laboratories without any POC testing. A significant increase in volumes would result in a four-fold increase at busier laboratories. CD4 laboratories would increase to 41 in scenario B and 61 in scenario C. POC testing would be offered at two sites in scenario B and 20 sites in scenario C. Conclusion: The RACL algorithm provides an objective methodology to address coverage gaps through the allocation of CD4 laboratories and POC sites for a given T. The algorithm outcomes need to be assessed in the context of local conditions.

  5. Library Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Carnegie Library of Pittsburgh locations including address, coordinates, phone number, square footage, and standard operating hours. The map below does not display...

  6. TOPOLOGICALLY CONSISTENT MODELS FOR EFFICIENT BIG GEO-SPATIO-TEMPORAL DATA DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    M. W. Jahn

    2017-10-01

    Full Text Available Geo-spatio-temporal topology models are likely to become a key concept to check the consistency of 3D (spatial space and 4D (spatial + temporal space models for emerging GIS applications such as subsurface reservoir modelling or the simulation of energy and water supply of mega or smart cities. Furthermore, the data management for complex models consisting of big geo-spatial data is a challenge for GIS and geo-database research. General challenges, concepts, and techniques of big geo-spatial data management are presented. In this paper we introduce a sound mathematical approach for a topologically consistent geo-spatio-temporal model based on the concept of the incidence graph. We redesign DB4GeO, our service-based geo-spatio-temporal database architecture, on the way to the parallel management of massive geo-spatial data. Approaches for a new geo-spatio-temporal and object model of DB4GeO meeting the requirements of big geo-spatial data are discussed in detail. Finally, a conclusion and outlook on our future research are given on the way to support the processing of geo-analytics and -simulations in a parallel and distributed system environment.

  7. Topologically Consistent Models for Efficient Big Geo-Spatio Data Distribution

    Science.gov (United States)

    Jahn, M. W.; Bradley, P. E.; Doori, M. Al; Breunig, M.

    2017-10-01

    Geo-spatio-temporal topology models are likely to become a key concept to check the consistency of 3D (spatial space) and 4D (spatial + temporal space) models for emerging GIS applications such as subsurface reservoir modelling or the simulation of energy and water supply of mega or smart cities. Furthermore, the data management for complex models consisting of big geo-spatial data is a challenge for GIS and geo-database research. General challenges, concepts, and techniques of big geo-spatial data management are presented. In this paper we introduce a sound mathematical approach for a topologically consistent geo-spatio-temporal model based on the concept of the incidence graph. We redesign DB4GeO, our service-based geo-spatio-temporal database architecture, on the way to the parallel management of massive geo-spatial data. Approaches for a new geo-spatio-temporal and object model of DB4GeO meeting the requirements of big geo-spatial data are discussed in detail. Finally, a conclusion and outlook on our future research are given on the way to support the processing of geo-analytics and -simulations in a parallel and distributed system environment.

  8. Beyond histograms: Efficiently estimating radial distribution functions via spectral Monte Carlo

    Science.gov (United States)

    Patrone, Paul N.; Rosch, Thomas W.

    2017-03-01

    Despite more than 40 years of research in condensed-matter physics, state-of-the-art approaches for simulating the radial distribution function (RDF) g(r) still rely on binning pair-separations into a histogram. Such methods suffer from undesirable properties, including subjectivity, high uncertainty, and slow rates of convergence. Moreover, such problems go undetected by the metrics often used to assess RDFs. To address these issues, we propose (I) a spectral Monte Carlo (SMC) quadrature method that yields g(r) as an analytical series expansion and (II) a Sobolev norm that assesses the quality of RDFs by quantifying their fluctuations. Using the latter, we show that, relative to histogram-based approaches, SMC reduces by orders of magnitude both the noise in g(r) and the number of pair separations needed for acceptable convergence. Moreover, SMC reduces subjectivity and yields simple, differentiable formulas for the RDF, which are useful for tasks such as coarse-grained force-field calibration via iterative Boltzmann inversion.

  9. An Efficient Distributed Coverage Hole Detection Protocol for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Prasan Kumar Sahoo

    2016-03-01

    Full Text Available In wireless sensor networks (WSNs, certain areas of the monitoring region may have coverage holes and serious coverage overlapping due to the random deployment of sensors. The failure of electronic components, software bugs and destructive agents could lead to the random death of the nodes. Sensors may be dead due to exhaustion of battery power, which may cause the network to be uncovered and disconnected. Based on the deployment nature of the nodes in remote or hostile environments, such as a battlefield or desert, it is impossible to recharge or replace the battery. However, the data gathered by the sensors are highly essential for the analysis, and therefore, the collaborative detection of coverage holes has strategic importance in WSNs. In this paper, distributed coverage hole detection algorithms are designed, where nodes can collaborate to detect the coverage holes autonomously. The performance evaluation of our protocols suggests that our protocols outperform in terms of hole detection time, limited power consumption and control packet overhead to detect holes as compared to other similar protocols.

  10. Reflectance bandwidth and efficiency improvement of light-emitting diodes with double-distributed Bragg reflector.

    Science.gov (United States)

    Ding, Xinghuo; Gui, Chengqun; Hu, Hongpo; Liu, Mengling; Liu, Xingtong; Lv, Jiajiang; Zhou, Shengjun

    2017-05-20

    Distributed Bragg reflectors (DBR) with metal film on the bottom have been demonstrated to further improve the light output power of GaN-based light-emitting diodes (LEDs). Periods of TiO2/SiO2 stacks, thickness of metal film, and material of metallic reflector were designed and optimized in simulation software. The maximal bandwidth of double-DBR stacks have reached up to 272 nm, which was 102 nm higher than a single-DBR stack. The average reflectance of LEDs with wavelength from 380 nm to 780 nm in double-DBR stacks is 95.09% at normal incident, which was much higher than that of a single-DBR stack whose average reflectance was 91.38%. Meanwhile, maximal average reflectance of LEDs for double-DBR stacks with an incident angle from 0 to 90° was 97.41%, which was 3.2% higher than that of a single-DBR stack with maximal average reflectance of 94.21%. The light output power of an LED with double-DBR stacks is 3% higher than that of an LED with a single-DBR stack, which was attributed to high reflectance of double-DBR stacks.

  11. Beam loss distribution calculation and collimation efficiency simulation of a cooler storage ring in a heavy ion research facility

    Directory of Open Access Journals (Sweden)

    Peng Li

    2014-08-01

    Full Text Available The Heavy Ion Research Facility in Lanzhou is an ion cooler storage ring facility in China’s Institute of Modern Physics. The beams are accumulated, electron cooled, accelerated, and extracted from the main cooler storage ring (CSRm to the experimental ring or different terminals. The heavy ion beams are easily lost at the vacuum chamber along the CSRm when it is used to accumulate intermediate charge state particles. The vacuum pressure bump due to the ion-induced desorption in turn leads to an increase in beam loss rate. In order to avoid the complete beam loss, the collimation system is investigated and planned to be installed in the CSRm. First, the beam loss distribution is simulated considering the particle charge exchanged process. Then the collimation efficiency of the lost particles is calculated and optimized under different position and geometry of the collimators and beam emittance and so on. Furthermore, the beam orbit distortion that is caused by different types of errors in the ring will affect the collimation efficiency. The linearized and inhomogeneous equations of particle motion with these errors are derived and solved by an extended transfer matrix method. Actual magnet alignment errors are adopted to investigate the collimation efficiency of the lost particles in the CSRm. Estimation of the beam loss positions and optimization of the collimation system is completed by a newly developed simulation program.

  12. Effects of narrow plant spacing on root distribution and physiological nitrogen use efficiency in summer maize

    Directory of Open Access Journals (Sweden)

    Wenshun Jiang

    2013-10-01

    Full Text Available The objective of this study was to understand the effects of plant spacing on grain yield and root competition in summer maize (Zea mays L.. Maize cultivar Denghai 661 was planted in rectangular tanks (0.54 m × 0.27 m × 1.00 m under 27 cm (normal and 6 cm (narrow plant spacing and treated with zero and 7.5 g nitrogen (N per plant. Compared to normal plant spacing, narrow plant spacing generated less root biomass in the 0–20 cm zone under both N rates, slight reductions of dry root weight in the 20–40 cm and 40–70 cm zones at the mid-grain filling stage, and slight variation of dry root weights in the 70–100 cm zone during the whole growth period. Narrow plant spacing decreased root reductive activity in all root zones, especially at the grain-filling stage. Grain yield and above-ground biomass were 5.0% and 8.4% lower in the narrow plant spacing than with normal plant spacing, although narrow plant spacing significantly increased N harvest index and N use efficiency in both grain yield and biomass, and higher N translocation rates from vegetative organs. These results indicate that the reductive activity of maize roots in all soil layers and dry weights of shallow roots were significantly decreased under narrow plant spacing conditions, resulting in lower root biomass and yield reduction at maturity. Therefore, a moderately dense sowing is a basis for high yield in summer maize.

  13. Effect of subcellular distribution on nC₆₀ uptake and transfer efficiency from Scenedesmus obliquus to Daphnia magna.

    Science.gov (United States)

    Chen, Qiqing; Hu, Xialin; Yin, Daqiang; Wang, Rui

    2016-06-01

    The potential uptake and trophic transfer ability of nanoparticles (NPs) in aquatic organisms have not been well understood yet. There has been an increasing awareness of the subcellular fate of NPs in organisms, but how the subcellular distribution of NPs subsequently affects the trophic transfer to predator remains to be answered. In the present study, the food chain from Scenedesmus obliquus to Daphnia magna was established to simulate the trophic transfer of fullerene aqueous suspension (nC60). The nC60 contaminated algae were separated into three fractions: cell wall (CW), cell organelle (CO), and cell membrane (CM) fractions, and we investigated the nC60 uptake amounts and trophic transfer efficiency to the predator through dietary exposure to algae or algal subcellular fractions. The nC60 distribution in CW fraction of S. obliquus was the highest, following by CO and CM fractions. nC60 uptake amounts in D. magna were found to be mainly relative to the NPs' distribution in CW fraction and daphnia uptake ability from CW fraction, whereas the nC60 trophic transfer efficiency (TE) were mainly in accordance with the transfer ability of NPs from the CO fraction. CW fed group possessed the highest uptake amount, followed by CO and CM fed groups, but the presence of humic acid (HA) significantly decreased the nC60 uptake from CW fed group. The CO fed groups acquired high TE values for nC60, while CM fed groups had low TE values. Moreover, even though CW fed group had a high TE value; it decreased significantly with the presence of HA. This study contributes to the understanding of fullerene NPs' dietary exposure to aquatic organisms, suggesting that NPs in different food forms are not necessarily equally trophically available to the predator. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Verification of the efficiency of chemical disinfection and sanitation measures in in-building distribution systems.

    Science.gov (United States)

    Lenz, J; Linke, S; Gemein, S; Exner, M; Gebel, J

    2010-06-01

    Previous investigations of biofilms, generated in a silicone tube model have shown that the number of colony forming units (CFU) can reach 10(7)/cm(2), the total cell count (TCC) of microorganisms can be up to 10(8)cells/cm(2). The present study focuses on the situation in in-building distribution systems. Different chemical disinfectants were tested for their efficacy on drinking water biofilms in silicone tubes: free chlorine (electrochemically activated), chlorine dioxide, hydrogen peroxide (H(2)O(2)), silver, and fruit acids. With regard to the widely differing manufacturers' instructions for the usage of their disinfectants three different variations of the silicone tube model were developed to simulate practical use conditions. First the continuous treatment, second the intermittent treatment, third the efficacy of external disinfection treatment and the monitoring for possible biofilm formation with the Hygiene-Monitor. The working experience showed that it is important to know how to handle the individual disinfectants. Every active ingredient has its own optimal application concerning its concentration, exposure time, physical parameters like pH, temperature or redox potential. When used correctly all products tested were able to reduce the CFU to a value below the detection limit. Most of the active ingredients could not significantly reduce the TCC/cm(2), which means that viable microorganisms may still be present in the system. Thus the question arises what happened with these cells? In some cases SEM pictures of the biofilm matrix after a successful disinfection still showed biofilm residues. According to these results, no general correlation between CFU/cm(2), TCC/cm(2) and the visualised biofilm matrix on the silicone tube surface (SEM) could be demonstrated after a treatment with disinfectants. Copyright 2010 Elsevier GmbH. All rights reserved.

  15. Generic Network Location Service

    Directory of Open Access Journals (Sweden)

    Laban Mwansa

    2010-11-01

    Full Text Available This work presents the Generic Network Location Service based on the Chord implementation utilizing data structures called distributed hash tables (DHT or structured overlay networks, which are used to build scalable self-managing distributed systems. The provided algorithms guarantee resilience in the presence of dynamism: they guarantee consistent lookup results in the presence of nodes failing and leaving. Generic Network Location Service provides a Location Service system based on DHT technology, which is storing device location records in nodes within a Chord DHT. Location records are consisting of network device identification keys as attributes, which are used to create replicas of additional location records through established Chord hashing mechanisms. Storing device location records, in places address-able (using the DHT lookup by individual location record keys provides a simple way of implementing transla¬tion functions similar to well¬ known network services (e.g. ARP, DNS, ENUM. The generic network location ser¬vice presented in the paper is not supposed to be a substitu¬tion of the existing translation techniques (e.g. ARP, DNS, ENUM, but it is considered as an overlay service that uses data available in existing systems and provides some translations currently unavailable.

  16. Assessment of reliability and efficiency of mining coal seams located above or below extracted coal seams with support coal pillars. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I.

    1981-04-01

    Mining thin (under 1.1 m) coal seams located above or below extracted thicker coal seams in which coal support pillars were left is one of the ways of increasing coal output without major investment in Donbass coal mines. It is planned that by 1985 25 thin coal seams will be mined in the Donbass. Investigations show that mining thin coal seams with gradients up to 12 degrees by a system of raise faces without leaving coal pillars is economical using mining systems available at present. This mining scheme is economical also in the case of coal seams located in zones of geologic dislocations. Using integrated mining systems (coal cutter, powered supports and face conveyor) in this coal seams would reduce mining cost from 0.2 to 0.3 rubles/t. Using automated integrated mining systems is economical in working faces with coal output exceeding 900 t/d. (3 refs.) (In Russian)

  17. Spatial and temporal distribution of cotton squares and small cotton bolls fallen on ground after damage by boll weevil and the efficiency of the equipment used to collect them

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Domingues da Silva

    Full Text Available ABSTRACT: In this study, we determined the spatial and temporal distribution of fallen cotton squares and small cotton bolls fallen damaged by boll weevil and the efficiency and time interval of the equipment used to collect cotton samples. Spatial and temporal distribution of cotton squares and small cotton bolls fallen on the soil damaged by boll weevil among cotton rows was determined in an experimental design of randomized blocks in a factorial arrangement of 4x3, represented by soil surface tracks located at 1-11cm, 12-22cm, 23-33cm, and 34-44cm away from the planting row of cotton plants 70, 85, and 100 days of age. Efficiency and collection time interval of the cotton samples fallen on the soil infested by boll weevil by plastic rakes that were straight or fan-shaped, big broom, collector instrument model CNPA and aspirator of leaves ‘Trapp’ were determined in randomized block design with five treatments, 10 repetitions for each. Results demonstrated that the collection of cotton samples must be performed with greater attention to soil strips located below the cotton top projection and aspirator ‘Trapp’ of leaves was more appropriate for the operation as it used less time of collection with similar efficiency to other available equipment.

  18. Effect of Plant Characteristics and Within-Plant Distribution of Prey on Colonization Efficiency of Cryptolaemus montrouzieri (Coleoptera: Coccinellidae Adults

    Directory of Open Access Journals (Sweden)

    Folukemi Adedipe

    2012-01-01

    Full Text Available Cryptolaemus montrouzieri (Coleoptera: Coccinellidae has been widely used in classical and inundative biological control of mealybugs, including the long-tailed mealybug, Pseudococcus longispinus (Hemiptera: Pseudococcidae. This study was conducted to investigate colonization and establishment efficiency of C. montrouzieri to manage P. longispinus on three different ornamental plant species (Ficus elastica, Lilium longiflorum, and Dieffenbachia seguine. Within-plant distribution pattern of P. longispinus and the colonization ecology of adult C. montrouzieri were investigated. Significantly more P. longispinus were found on the upper parts of the plants regardless of plant species, and C. montrouzieri adults discovered P. longispinus significantly faster when they were released on the top of the plants than on the bottom. Choice tests revealed that C. montrouzieri adults preferred smaller P. longispinus nymphs. The implications for utilization of C. montrouzieri for biological control of mealybugs on various ornamental plants are discussed.

  19. Efficient, graph-based white matter connectivity from orientation distribution functions via multi-directional graph propagation

    Science.gov (United States)

    Boucharin, Alexis; Oguz, Ipek; Vachet, Clement; Shi, Yundi; Sanchez, Mar; Styner, Martin

    2011-03-01

    The use of regional connectivity measurements derived from diffusion imaging datasets has become of considerable interest in the neuroimaging community in order to better understand cortical and subcortical white matter connectivity. Current connectivity assessment methods are based on streamline fiber tractography, usually applied in a Monte-Carlo fashion. In this work we present a novel, graph-based method that performs a fully deterministic, efficient and stable connectivity computation. The method handles crossing fibers and deals well with multiple seed regions. The computation is based on a multi-directional graph propagation method applied to sampled orientation distribution function (ODF), which can be computed directly from the original diffusion imaging data. We show early results of our method on synthetic and real datasets. The results illustrate the potential of our method towards subjectspecific connectivity measurements that are performed in an efficient, stable and reproducible manner. Such individual connectivity measurements would be well suited for application in population studies of neuropathology, such as Autism, Huntington's Disease, Multiple Sclerosis or leukodystrophies. The proposed method is generic and could easily be applied to non-diffusion data as long as local directional data can be derived.

  20. Leaf gas exchange and nutrient use efficiency help explain the distribution of two Neotropical mangroves under contrasting flooding and salinity

    Science.gov (United States)

    Cardona-Olarte, Pablo; Krauss, Ken W.; Twilley, Robert R.

    2013-01-01

    Rhizophora mangle and Laguncularia racemosa co-occur along many intertidal floodplains in the Neotropics. Their patterns of dominance shift along various gradients, coincident with salinity, soil fertility, and tidal flooding. We used leaf gas exchange metrics to investigate the strategies of these two species in mixed culture to simulate competition under different salinity concentrations and hydroperiods. Semidiurnal tidal and permanent flooding hydroperiods at two constant salinity regimes (10 g L−1 and 40 g L−1) were simulated over 10 months. Assimilation (A), stomatal conductance (gw), intercellular CO2 concentration (Ci), instantaneous photosynthetic water use efficiency (PWUE), and photosynthetic nitrogen use efficiency (PNUE) were determined at the leaf level for both species over two time periods. Rhizophora mangle had significantly higher PWUE than did L. racemosa seedlings at low salinities; however, L. racemosa had higher PNUE and stomatal conductance and gw, accordingly, had greater intercellular CO2 (calculated) during measurements. Both species maintained similar capacities for assimilation at 10 and 40 g L−1 salinity and during both permanent and tidal hydroperiod treatments. Hydroperiod alone had no detectable effect on leaf gas exchange. However, PWUE increased and PNUE decreased for both species at 40 g L−1 salinity compared to 10 g L−1. At 40 g L−1 salinity, PNUE was higher for L. racemosa than R. mangle with tidal flooding. These treatments indicated that salinity influences gas exchange efficiency, might affect how gases are apportioned intercellularly, and accentuates different strategies for distributing leaf nitrogen to photosynthesis for these two species while growing competitively.

  1. Leaf Gas Exchange and Nutrient Use Efficiency Help Explain the Distribution of Two Neotropical Mangroves under Contrasting Flooding and Salinity

    Directory of Open Access Journals (Sweden)

    Pablo Cardona-Olarte

    2013-01-01

    Full Text Available Rhizophora mangle and Laguncularia racemosa cooccur along many intertidal floodplains in the Neotropics. Their patterns of dominance shift along various gradients, coincident with salinity, soil fertility, and tidal flooding. We used leaf gas exchange metrics to investigate the strategies of these two species in mixed culture to simulate competition under different salinity concentrations and hydroperiods. Semidiurnal tidal and permanent flooding hydroperiods at two constant salinity regimes (10 g L−1 and 40 g L−1 were simulated over 10 months. Assimilation (A, stomatal conductance (gw, intercellular CO2 concentration (Ci, instantaneous photosynthetic water use efficiency (PWUE, and photosynthetic nitrogen use efficiency (PNUE were determined at the leaf level for both species over two time periods. Rhizophora mangle had significantly higher PWUE than did L. racemosa seedlings at low salinities; however, L. racemosa had higher PNUE and gw and, accordingly, had greater intercellular CO2 (calculated during measurements. Both species maintained similar capacities for A at 10 and 40 g L−1 salinity and during both permanent and tidal hydroperiod treatments. Hydroperiod alone had no detectable effect on leaf gas exchange. However, PWUE increased and PNUE decreased for both species at 40 g L−1 salinity compared to 10 g L−1. At 40 g L−1 salinity, PNUE was higher for L. racemosa than R. mangle with tidal flooding. These treatments indicated that salinity influences gas exchange efficiency, might affect how gases are apportioned intercellularly, and accentuates different strategies for distributing leaf nitrogen to photosynthesis for these two species while growing competitively.

  2. Distributing and storing required data efficiently by means of specifically tailored data formats in the ATLAS collaboration

    CERN Document Server

    Koeneke, K; The ATLAS collaboration

    2011-01-01

    With the start of the LHC physics program, the ATLAS experiment started to record vast amounts of data. This data has to be distributed and stored on the world-wide computing grid in a smart way in order to enable an effective and efficient analysis by physicists. There are in principle two classes of analysis that are required. In the commissioning phase of the ATLAS experiment, low-level Event Summary Data (ESD), the result of the event reconstruction, has to be analyzed to evaluate the performance of the individual subdetectors, the performance of the reconstruction and particle identification algorithms, and to obtain calibration coefficients. For later physics analysis, it is usually sufficient to use the less detailed Analysis Object Data (AOD), which is a less-detailed version of the ESD. In the grid model of distributed analysis, these data must be transferred to Tier-2 sites before they can be analyzed. However, the large size of ESD (~1 MByte/event) constrains the amount of detailed data that can be...

  3. Effects of the distribution density of a biomass combined heat and power plant network on heat utilisation efficiency in village-town systems.

    Science.gov (United States)

    Zhang, Yifei; Kang, Jian

    2017-11-01

    The building of biomass combined heat and power (CHP) plants is an effective means of developing biomass energy because they can satisfy demands for winter heating and electricity consumption. The purpose of this study was to analyse the effect of the distribution density of a biomass CHP plant network on heat utilisation efficiency in a village-town system. The distribution density is determined based on the heat transmission threshold, and the heat utilisation efficiency is determined based on the heat demand distribution, heat output efficiency, and heat transmission loss. The objective of this study was to ascertain the optimal value for the heat transmission threshold using a multi-scheme comparison based on an analysis of these factors. To this end, a model of a biomass CHP plant network was built using geographic information system tools to simulate and generate three planning schemes with different heat transmission thresholds (6, 8, and 10 km) according to the heat demand distribution. The heat utilisation efficiencies of these planning schemes were then compared by calculating the gross power, heat output efficiency, and heat transmission loss of the biomass CHP plant for each scenario. This multi-scheme comparison yielded the following results: when the heat transmission threshold was low, the distribution density of the biomass CHP plant network was high and the biomass CHP plants tended to be relatively small. In contrast, when the heat transmission threshold was high, the distribution density of the network was low and the biomass CHP plants tended to be relatively large. When the heat transmission threshold was 8 km, the distribution density of the biomass CHP plant network was optimised for efficient heat utilisation. To promote the development of renewable energy sources, a planning scheme for a biomass CHP plant network that maximises heat utilisation efficiency can be obtained using the optimal heat transmission threshold and the nonlinearity

  4. A new approach for an efficiently distributed processing in wireless sensor networks; Ein neues Modell zur energiebewussten verteilten Verarbeitung in drahtlosen Sensornetzen

    Energy Technology Data Exchange (ETDEWEB)

    Lantow, Birger

    2012-07-01

    The limited resource energy is the biggest obstacle for the introduction of new application fields to WSN (Wireless Sensor Networks). Generally, this is caused by a limited amount of energy available to each node of a WSN during the nodes' lifetime. In other cases, the power supply for WSN-nodes is highly limited. Thus, Energy-efficiency is an important design goal of WSN hard- and software. This thesis introduces a new modell for the description of distributed data processing energy consumption. Based on this model, distributions of processing load are discussed with respect to energy efficiency. Here, energy efficiency is defined as the ratio between reached system lifetime and initial energy amount supplied to the sensor nodes. Design principles are developed for the implementation of protocols which generate energy efficient processing load distributions. For a deterministic version of the energy consumption model, optimal processing load distributions and their determination are shown. This includes a comparison with processing load distributions that minimize total energy consumption. Generally, decisions about processing load distribution in WSN have to be done perpetually and under insufficient information. Therefore, the quality of found optimal distributions for the deterministic model is evaluated for this process of online decisions. Based on this, future research activities on the topic are discussed. (orig.)

  5. Energy production, distribution, and pollution controls: Combining engineering and economic analysis to enhance efficiency and policy design

    Science.gov (United States)

    Perkis, David F.

    Three published articles are presented which focus on enhancing various aspects of the energy supply chain. While each paper adopts a different methodology, all three combine engineering data and/or techniques with economic analysis to improve efficiency or policy design within energy markets. The first paper combines a chemical engineering plant design model with an economic assessment of product enhancements within an ethanol production facility. While a new chemical process is shown to achieve greater ethanol yields, the animal feed by-products are denatured and decrease in value due to the degradation of a key nutritional amino acid. Overall, yield increases outweigh any costs, providing additional value to firms adopting this process. The second paper uses a mixed integer linear model to assess the optimal location of cellulosic ethanol production facilities within the state of Indiana. Desired locations with low costs are linked to regions with high yield corn growth, as these areas provide an abundance of corn stover, a by-product of corn and a cellulosic source of ethanol. The third paper implements experimental economic methods to assess the effectiveness of policies intended to control prices in emissions permit markets. When utilizing reserve permit auctions as an alternative to setting explicit maximum prices, prices are elevated beyond the theoretical predictions of the model within the conditions of the experiment. The most likely cause of higher prices is the negotiating power provided to sellers by grandfathering permits as evidenced by higher than expected welfare gains to sellers. Before presenting the articles, a discussion is introduced regarding the role of assumptions used by economists. For each article, a key assumption is highlighted and the consequences of making a different assumption are provided. Whether the consequences are large or small, the benefits of elucidating our models with assumptions based on real world behaviors are clearly

  6. The response of a simulated mesoscale convective system to increased aerosol pollution: Part I: Precipitation intensity, distribution, and efficiency

    Science.gov (United States)

    Clavner, Michal; Cotton, William R.; van den Heever, Susan C.; Saleeby, Stephen M.; Pierce, Jeffery R.

    2018-01-01

    Mesoscale Convective Systems (MCSs) are important contributors to rainfall in the High Plains of the United States and elsewhere in the world. It is therefore of interest to understand how different aerosols serving as cloud condensation nuclei (CCN) may impact the total amount, rates and spatial distribution of precipitation produced by MCSs. In this study, different aerosol concentrations and their effects on precipitation produced by an MCS are examined by simulating the 8 May 2009 "Super-Derecho" MCS using the Regional Atmospheric Modeling System (RAMS), a cloud-resolving model (CRM) with sophisticated aerosol and microphysical parameterizations. Three simulations were conducted that differed only in the initial concentration, spatial distribution, and chemical composition of aerosols. Aerosol fields were derived from the output of GEOS-Chem, a 3D chemical transport numerical model. Results from the RAMS simulations show that the total domain precipitation was not significantly affected by variations in aerosol concentrations, however, the pollution aerosols altered the precipitation characteristics. The more polluted simulations exhibited higher precipitation rates, higher bulk precipitation efficiency, a larger area with heavier precipitation, and a smaller area with lighter precipitation. These differences arose as a result of aerosols enhancing precipitation in the convective region of the MCS while suppressing precipitation from the MCS's stratiform-anvil. In the convective region, several processes likely contributed to an increase of precipitation. First, owing to the very humid environment of this storm, the enhanced amount of cloud water available to be collected overwhelmed the reduction in precipitation efficiency associated with the aerosol-induced production of smaller droplets which led to a net increase in the conversion of cloud droplets to precipitation. Second, higher aerosol concentrations led to invigoration of convective updrafts which

  7. Application of HVJ-liposome mediated gene transfer in lung transplantation-distribution and transfection efficiency in the lung.

    Science.gov (United States)

    Ohmori, Kenichi; Takeda, Shin-ichi; Miyoshi, Shinichiro; Minami, Masato; Nakane, Shigeru; Ohta, Mitsunori; Sawa, Yoshiki; Matsuda, Hikaru

    2005-05-01

    A novel hemagglutinating virus of Japan (HVJ)-liposome-mediated gene transfer system has been shown to have benefits of a high efficiency of transfection and low immunogenicity. The aims of this study were to determine the effect of re-transfection of the HVJ-liposome system via the airway, and to quantify the distribution of gene expression between transtracheal and transplantation approaches. Beta-galactosidase (beta-gal) plasmid DNA was introduced into lung tissues using the HVJ-liposome method. Two groups of Sprague-Dawley (SD) rats received intratracheal instillation of 10 microg of the beta-gal gene, once on Day 0 in 1 group (Group Tb-1, n=4) and 3 times on Days 0-2 in another (Group Tb-3, n=4). In a third group of SD rats (Group Tx, n=5), an orthotopic left lung transplantation was performed after the donor lung was flushed with an HVJ-liposome complex solution and preserved for 1h. Gene expression and distribution in lung tissue was then quantified by counting the X-gal stained cells. Both the transtracheal and transplantation approaches resulted in low levels of transfection in the vascular endothelial cells (0.2+/-0.1 and 4.0+/-1.8%), respectively, but a moderate degree of transfection to the airway (11.0+/-7.1 and 28.0+/-20.7%) and alveolar cells (3.0+/-1.8 and 6.0+/-3.6%). Three repetitive injections via the airway increased gene expression in airway epithelial cells of 41.0+/-12.0% compared with the single administration of 11.0+/-4.3%. Our results suggest that the repeated transtracheal gene transfection using HVJ-liposome may have benefits for treatment of problems after lung transplantation. In addition, gene transfer using a flushing solution during harvest may provide an opportunity for gene manipulation in the setting of lung transplantation.

  8. Distribution of mercury in Gypsy Cortinarius caperatus mushrooms from several populations: an efficient accumulator species and estimated intake of element.

    Science.gov (United States)

    Falandysz, Jerzy

    2014-12-01

    Mushroom Cortinarius caperatus is one of the several edible wild-grown species that are widely collected by fanciers. For specimens collected from 20 spatially and distantly distributed sites in Poland the median values of Hg contents of caps ranged from 0.81 to 2.4mgkg(-1) dry matter and in stipes they were 2.5-fold lower. C. caperatus efficiently accumulates Hg and the median values of the bioconcentration factor for caps range from 120 to 18 and for stipes from 47 to 7.3. This mushroom even when collected at background (uncontaminated) forested areas could be a source of elevated intake of Hg. The irregular consumption of the caps or whole fruiting bodies is not considered to pose a risk. Frequent eating of C. caperatus during the fruiting season by fanciers should be avoided because of possible health risk from Hg. Available data on Hg contents of C. caperatus from several places in Europe are also summarized. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Comparison between whole distribution- and average-based approaches to the determination of fluorescence resonance energy transfer efficiency in ensembles of proteins in living cells.

    Science.gov (United States)

    Singh, Deo R; Raicu, Valerică

    2010-05-19

    Current methods for analysis of data from studies of protein-protein interactions using fluorescence resonance energy transfer (FRET) emerged from several decades of research using wide-field microscopes and spectrofluorometers to measure fluorescence from individual cells or cell populations. Inherent to most measurements is an averaging of the distributions of FRET efficiencies over large populations of protein complexes, which washes out information regarding the stoichiometry and structure of protein complexes. Although the introduction of laser-scanning microscopes in principle could facilitate quantification of the distributions of FRET efficiencies in live cells, only comparatively recently did this potential fully materialize, through development of spectral- or lifetime-based approaches. To exploit this new opportunity in molecular imaging, it is necessary to further develop theoretical models and methods of data analysis. Using Monte Carlo simulations, we investigated FRET in homogenous and inhomogeneous spatial distributions of molecules. Our results indicate that an analysis based on distributions of FRET efficiencies presents significant advantages over the average-based approach, which include allowing for proper identification of biologically relevant FRET. This study provides insights into the effect of molecular crowding on FRET, and it offers a basis for information extraction from distributions of FRET efficiencies using simulations-based data fitting. Copyright 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  10. Using publically available forest inventory data in climate-based modes of tree species distribution: Examining effects of true versus altered location coordinates

    Science.gov (United States)

    Jacob Gibson; Gretchen Moisen; Tracey Frescino; Thomas C. Edwards

    2013-01-01

    Species distribution models (SDMs) were built with US Forest Inventory and Analysis (FIA) publicly available plot coordinates, which are altered for plot security purposes, and compared with SDMs built with true plot coordinates. Six species endemic to the western US, including four junipers (Juniperus deppeana var. deppeana, J. monosperma, J. occidentalis, J....

  11. Highly efficient single-pass frequency doubling of a continuous-wave distributed feedback laser diode using a PPLN waveguide crystal at 488 nm.

    Science.gov (United States)

    Jechow, Andreas; Schedel, Marco; Stry, Sandra; Sacher, Joachim; Menzel, Ralf

    2007-10-15

    A continuous-wave distributed feedback diode laser emitting at 976 nm was frequency doubled by the use of a periodically poled lithium niobate waveguide crystal with a channel size of 3 microm x 5 microm and an interaction length of 10 mm. A laser to waveguide coupling efficiency of 75% could be achieved resulting in 304 mW of incident infrared light inside the waveguide. Blue laser light emission of 159 mW at 488 nm has been generated, which equals to a conversion efficiency of 52%. The resulting wall plug efficiency was 7.4%.

  12. Nitrogen uptake, distribution, turnover, and efficiency of use in a CO2-enriched sweetgum forest

    Energy Technology Data Exchange (ETDEWEB)

    Norby, Richard J [ORNL; Iversen, Colleen M [ORNL

    2006-01-01

    The Progressive Nitrogen Limitation (PNL) hypothesis suggests that ecosystems in a CO2-enriched atmosphere will sequester C and N in long-lived biomass and soil organic pools, thereby limiting available N and constraining the continued response of net primary productivity to elevated [CO2]. Here, we present a six-year record of N dynamics of a sweetgum (Liquidambar styraciflua) stand exposed to elevated [CO2] in the free-air CO2 enrichment (FACE) experiment at Oak Ridge, Tennessee, USA. We also evaluate the concept of PNL for this ecosystem from the perspective of N uptake, content, distribution, and turnover, and N-use efficiency. Leaf N content was 11 percent lower on a leaf mass basis (NM) and 7 percent lower on a leaf area basis (NA) in CO2-enriched trees. However, there was no effect of [CO2] on total canopy N content. Resorption of N during senescence was not altered by [CO2], so NM of litter, but not total N content, was reduced. The NM of fine roots was not affected, but the total amount of N required for fine-root production increased significantly, reflecting the large stimulation of fine-root production in this stand. Hence, total N requirement of the trees was higher in elevated [CO2], and the increased requirement was met through an increase in N uptake rather than increased retranslocation of stored reserves. Increased N uptake was correlated with increased net primary productivity (NPP). N-use efficiency, however, did not change with CO2 enrichment because increased N productivity was offset by lower mean residence time of N in the trees. None of the measured responses of plant N dynamics in this ecosystem indicated the occurrence of PNL, and the stimulation of NPP by elevated [CO2] was sustained for the first six years of the experiment. Although there are some indications of developing changes in the N economy, the N supply in the soil at this site may be sufficient to meet an increasing demand for available N, especially as the roots of CO2

  13. An Adaptive Tabu Search Heuristic for the Location Routing Pickup and Delivery Problem with Time Windows with a Theater Distribution Application

    Science.gov (United States)

    2006-08-01

    where each type (e.g., able to walk , needs a wheelchair , etc.) requires suitable space on a vehicle from an origin to a destination (Mitrovic-Minic...planning theater distribution. These tools are designed to assist staff officers in developing information to facilitate the preparation of estimates...operations and across various terrains . For example, the Third Infantry Division (Mechanized) during Operation IRAQI FREEDOM (OIF) fought an asymmetric

  14. Rapid, Efficient and Versatile Strategies for Functionally Sophisticated Polymers and Nanoparticles: Degradable Polyphosphoesters and Anisotropic Distribution of Chemical Functionalities

    Science.gov (United States)

    Zhang, Shiyi

    The overall emphasis of this dissertation research included two kinds of asymmetrically-functionalized nanoparticles with anisotropic distributions of chemical functionalities, three degradable polymers synthesized by organocatalyzed ring-opening polymerizations, and two polyphosphoester-based nanoparticle systems for various biomedical applications. Inspired by the many hierarchical assembly processes that afford complex materials in Nature, the construction of asymmetrically-functionalized nanoparticles with efficient surface chemistries and the directional organization of those building blocks into complex structures have attracted much attention. The first method generated a Janus-faced polymer nanoparticle that presented two orthogonally click-reactive surface chemistries, thiol and azido. This robust method involved reactive functional group transfer by templating against gold nanoparticle substrates. The second method produced nanoparticles with sandwich-like distribution of crown ether functionalities through a stepwise self-assembly process that utilized crown ether-ammonium supramolecular interactions to mediate inter-particle association and the local intra-particle phase separation of unlike hydrophobic polymers. With the goal to improve the efficiency of the production of degradable polymers with tunable chemical and physical properties, a new type of reactive polyphosphoester was synthesized bearing alkynyl groups by an organocatalyzed ring-opening polymerization, the chemical availability of the alkyne groups was investigated by employing "click" type azide-alkyne Huisgen cycloaddition and thiol-yne radical-mediated reactions. Based on this alkyne-functionalized polyphosphoester polymer and its two available "click" type reactions, two degradable nanoparticle systems were developed. To develop the first system, the well defined poly(ethylene oxide)-block-polyphosphester diblock copolymer was transformed into a multifunctional Paclitaxel drug

  15. Experiences with Implementing a Distributed and Self-Organizing Scheduling Algorithm for Energy-Efficient Data Gathering on a Real-Life Sensor Network Platform

    NARCIS (Netherlands)

    Zhang, Y.; Chatterjea, Supriyo; Havinga, Paul J.M.

    2007-01-01

    We report our experiences with implementing a distributed and self-organizing scheduling algorithm designed for energy-efficient data gathering on a 25-node multihop wireless sensor network (WSN). The algorithm takes advantage of spatial correlations that exist in readings of adjacent sensor nodes

  16. Single- versus multi-channel distribution strategies in the German life insurance market: A cost and profit efficiency analysis

    OpenAIRE

    Trigo Gamarra, Lucinda

    2007-01-01

    Until its liberalisation in 1994 exclusive agents dominated the distribution of products in the German life insurance industry. Since then, their importance has been declining for the benefit of both distribution via direct distribution channel and independent agents. However, the market shares of specialized direct and independent agent insurers have remained small, while multi-channel insurers increasingly incorporate direct and independent distribution channels, and represent the dominant ...

  17. Distribution and mobility of lead (Pb), copper (Cu), zinc (Zn), and antimony (Sb) from ammunition residues on shooting ranges for small arms located on mires.

    Science.gov (United States)

    Mariussen, Espen; Johnsen, Ida Vaa; Strømseng, Arnljot Einride

    2017-04-01

    An environmental survey was performed on shooting ranges for small arms located on minerotrophic mires. The highest mean concentrations of Pb (13 g/kg), Cu (5.2 g/kg), Zn (1.1 g/kg), and Sb (0.83 g/kg) in the top soil were from a range located on a poor minerotrophic and acidic mire. This range had also the highest concentrations of Pb, Cu, Zn, and Sb in discharge water (0.18 mg/L Pb, 0.42 mg/L Cu, 0.63 mg/L Zn, and 65 μg/L Sb) and subsurface soil water (2.5 mg/L Pb, 0.9 mg/L Cu, 1.6 mg/L Zn, and 0.15 mg/L Sb). No clear differences in the discharge of ammunition residues between the mires were observed based on the characteristics of the mires. In surface water with high pH (pH ~7), there was a trend with high concentrations of Sb and lower relative concentrations of Cu and Pb. The relatively low concentrations of ammunition residues both in the soil and soil water, 20 cm below the top soil, indicates limited vertical migration in the soil. Channels in the mires, made by plant roots or soil layer of less decomposed materials, may increase the rate of transport of contaminated surface water into deeper soil layers and ground water. A large portion of both Cu and Sb were associated to the oxidizable components in the peat, which may imply that these elements form inner-sphere complexes with organic matter. The largest portion of Pb and Zn were associated with the exchangeable and pH-sensitive components in the peat, which may imply that these elements form outer-sphere complexes with the peat.

  18. NON-INVASIVE DETERMINATION OF THE LOCATION AND DISTRIBUTION OF FREE-PHASE DENSE NONAQUEOUS PHASE LIQUIDS (DNAPL) BY SEISMIC REFLECTION TECHNIQUES

    Energy Technology Data Exchange (ETDEWEB)

    Michael G. Waddell; William J. Domoracki; Tom J. Temples

    2001-12-01

    This annual technical progress report is for part of Task 4 (site evaluation), Task 5 (2D seismic design, acquisition, and processing), and Task 6 (2D seismic reflection, interpretation, and AVO analysis) on DOE contact number DE-AR26-98FT40369. The project had planned one additional deployment to another site other than Savannah River Site (SRS) or DOE Hanford Site. After the SUBCON midyear review in Albuquerque, NM, it was decided that two additional deployments would be performed. The first deployment is to test the feasibility of using non-invasive seismic reflection and AVO analysis as a monitoring tool to assist in determining the effectiveness of Dynamic Underground Stripping (DUS) in removal of DNAPL. The second deployment is to the Department of Defense (DOD) Charleston Naval Weapons Station Solid Waste Management Unit 12 (SWMU-12), Charleston, SC to further test the technique to detect high concentrations of DNAPL. The Charleston Naval Weapons Station SWMU-12 site was selected in consultation with National Energy Technology Laboratory (NETL) and DOD Naval Facilities Engineering Command Southern Division (NAVFAC) personnel. Based upon the review of existing data and due to the shallow target depth, the project team collected three Vertical Seismic Profiles (VSP) and an experimental P-wave seismic reflection line. After preliminary data analysis of the VSP data and the experimental reflection line data, it was decided to proceed with Task 5 and Task 6. Three high resolution P-wave reflection profiles were collected with two objectives; (1) design the reflection survey to image a target depth of 20 feet below land surface to assist in determining the geologic controls on the DNAPL plume geometry, and (2) apply AVO analysis to the seismic data to locate the zone of high concentration of DNAPL. Based upon the results of the data processing and interpretation of the seismic data, the project team was able to map the channel that is controlling the DNAPL plume

  19. Flow characteristics in occupied zone – An experimental study with symmetrically located thermal plumes and low-momentum diffuse ceiling air distribution

    DEFF Research Database (Denmark)

    Lestinen, Sami; Kilpeläinen, Simo; Kosonen, Risto

    2018-01-01

    (width) x 3.2 m (height) with symmetrical set-up of cylindrical heat sources that gave a thermal load of 40–80 W/floor-m2. The ventilation air was supplied through a diffuse ceiling with 0.5% degree of perforation. The observations indicate that the mean air speed and the airflow fluctuation increase......Airflow interaction between thermal plumes and vertical air distribution may cause significant effects on airflow characteristics such as velocity and temperature fields, turbulence intensity and fluctuation frequency. The flow interaction creates a random flow motion, vortical structures...... with thermal load. Furthermore, the results show that a range of length scales increases with thermal load and with mean air speed. The results indicate that it can be difficult to fulfill the standard air velocity criteria for highly occupied spaces, where the maximum allowable mean air velocity is relatively...

  20. Location Aggregation of Spatial Population CTMC Models

    Directory of Open Access Journals (Sweden)

    Luca Bortolussi

    2016-10-01

    Full Text Available In this paper we focus on spatial Markov population models, describing the stochastic evolution of populations of agents, explicitly modelling their spatial distribution, representing space as a discrete, finite graph. More specifically, we present a heuristic approach to aggregating spatial locations, which is designed to preserve the dynamical behaviour of the model whilst reducing the computational cost of analysis. Our approach combines stochastic approximation ideas (moment closure, linear noise, with computational statistics (spectral clustering to obtain an efficient aggregation, which is experimentally shown to be reasonably accurate on two case studies: an instance of epidemic spreading and a London bike sharing scenario.

  1. The distribution of RFLP markers on chromosome 2(2H) of barley in relation to the physical and genetic location of 5S rDNA.

    Science.gov (United States)

    Laurie, D A; Pratchett, N; Devos, K M; Leitch, I J; Gale, M D

    1993-10-01

    The 5S rDNA locus on the long arm of barley chromosome 2(2H) was genetically mapped in two crosses in relation to 30 other RFLP loci. Comparison of the genetic maps with the previously published physical position of the 5S rDNA, determined by in-situ hybridization, showed that there was a marked discrepancy between physical and genetic distance in both crosses, with recombination being less frequent in the proximal part of the arm. Pooled information from the present study and other published genetic maps showed that at least 26 of the 44 (59%) RFLPs that have been mapped on 2(2H)L lie distal to the 5S rDNA locus even though this region is only 27% of the physical length of the arm. The distribution of RFLP markers is significantly different from expected (P < 0.01), implying that the low-copy sequences used for RFLP analysis occur more frequently in distal regions of the arm and, or, that sequences in distal regions are more polymorphic.

  2. NON-INVASIVE DETERMINATION OF THE LOCATION AND DISTRIBUTION OF FREE-PHASE DENSE NONAQUEOUS PHASE LIQUIDS (DNAPL) BY SEISMIC REFLECTION TECHNIQUES

    Energy Technology Data Exchange (ETDEWEB)

    Michael G. Waddell; William J. Domoracki; Tom J. Temples

    2001-05-01

    This semi-annual technical progress report is for Task 4 site evaluation, Task 5 seismic reflection design and acquisition, and Task 6 seismic reflection processing and interpretation on DOE contact number DE-AR26-98FT40369. The project had planned one additional deployment to another site other than Savannah River Site (SRS) or DOE Hanford. During this reporting period the project had an ASME peer review. The findings and recommendation of the review panel, as well at the project team response to comments, are in Appendix A. After the SUBCON midyear review in Albuquerque, NM and the peer review it was decided that two additional deployments would be performed. The first deployment is to test the feasibility of using non-invasive seismic reflection and AVO analysis as monitoring to assist in determining the effectiveness of Dynamic Underground Stripping (DUS) in removal of DNAPL. Under the rescope of the project, Task 4 would be performed at the Charleston Navy Weapons Station, Charleston, SC and not at the Dynamic Underground Stripping (DUS) project at SRS. The project team had already completed Task 4 at the M-area seepage basin, only a few hundred yards away from the DUS site. Because the geology is the same, Task 4 was not necessary. However, a Vertical Seismic Profile (VSP) was conducted in one well to calibrate the geology to the seismic data. The first deployment to the DUS Site (Tasks 5 and 6) has been completed. Once the steam has been turned off these tasks will be performed again to compare the results to the pre-steam data. The results from the first deployment to the DUS site indicated a seismic amplitude anomaly at the location and depths of the known high concentrations of DNAPL. The deployment to another site with different geologic conditions was supposed to occur during this reporting period. The first site selected was DOE Paducah, Kentucky. After almost eight months of negotiation, site access was denied requiring the selection of another site

  3. Energy efficiency through design and sustainable construction of houses located in the Mexican Caribbean; Eficiencia Energetica a traves del diseno y construccion sostenible de viviendas ubicadas en el Caribe Mexicano

    Energy Technology Data Exchange (ETDEWEB)

    Bojorquez, I. B.; Perez, M. S.; Aguilar, J. A.

    2008-07-01

    Public policies focused to the Environment conservation and, low power consumption construction systems, are some of the Housing Sustainable Construction bases in an urban setting. This work approach to the analysis of the correlation power efficiency-design in the social housing located in the tropical-humid climate characteristic of the Mexican Caribbean, like starting point to define the recommendations of a Sustainable construction in this sector. the legal aspects were considered on sustainable construction and some experiences of investigation in the subject were reviewed. Also an exercise for the calculation of thermal gain was made as it bases of this analysis. This exercise is part of the project in process, that will define the recommendations of design for energy saving in the social housing. (Author)

  4. Prediction efficiency of the hydrographical parameters as related to distribution patterns of the Pleuromamma species in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Jayalakshmy, K.V.; Saraswathy, M.

    Among species of the genus Pleuromamma, P. indica was the only species existing in the Northern Indian Ocean. In the rest of the Indian Ocean the most abundant species was P. gracilis, and P. abdominalis was almost homogeneously distributed...

  5. RFID Location Algorithm

    Directory of Open Access Journals (Sweden)

    Wang Zi Min

    2016-01-01

    Full Text Available With the development of social services, people’s living standards improve further requirements, there is an urgent need for a way to adapt to the complex situation of the new positioning technology. In recent years, RFID technology have a wide range of applications in all aspects of life and production, such as logistics tracking, car alarm, security and other items. The use of RFID technology to locate, it is a new direction in the eyes of the various research institutions and scholars. RFID positioning technology system stability, the error is small and low-cost advantages of its location algorithm is the focus of this study.This article analyzes the layers of RFID technology targeting methods and algorithms. First, RFID common several basic methods are introduced; Secondly, higher accuracy to political network location method; Finally, LANDMARC algorithm will be described. Through this it can be seen that advanced and efficient algorithms play an important role in increasing RFID positioning accuracy aspects.Finally, the algorithm of RFID location technology are summarized, pointing out the deficiencies in the algorithm, and put forward a follow-up study of the requirements, the vision of a better future RFID positioning technology.

  6. FRONTIER METHODOLOGIES FOR THE DETERMINATION OF EFFICIENCIES IN DISTRIBUTION COSTS METODOLOGÍAS FRONTERAS PARA LA DETERMINACIÓN DE EFICIENCIA EN COSTOS DE DISTRIBUCIÓN

    Directory of Open Access Journals (Sweden)

    Raúl Sanhueza Hormazábal

    2007-12-01

    Full Text Available The efficiency of electric distribution companies is assessed under a productive efficiency criterion viewpoint. The analysis methodology consists of the estimation of frontier production costs functions; a parametric and a non parametric function. Two individual technical efficiency measurements for the distribution business are obtained from these functions. The assessment confirms actions and strategies that result in cost reductions in distribution companies. An application within the framework of the last Chilean regulatory process is illustrated in this work.Este trabajo analiza la eficiencia de empresas de distribución eléctrica, bajo el punto de vista del criterio de la eficiencia productiva. La metodología de análisis consiste en la estimación de funciones de costo de producción frontera, una paramétrica y otra no paramétrica. A partir de las mismas se obtienen dos medidas de la eficiencia técnica individual de cada explotación, lo que deja en evidencia acciones y estrategias que conducen a una reducción de costos para las empresas de distribución. Se ilustra su aplicación dentro del marco del último proceso regulatorio chileno.

  7. Location of Urban Logistic Terminals as Hub Location Problem

    Directory of Open Access Journals (Sweden)

    Jasmina Pašagić Škrinjar

    2012-09-01

    Full Text Available In this paper the problems of locating urban logistic terminals are studied as hub location problems that due to a large number of potential nodes in big cities belong to hard non-polynomial problems, the so-called NP-problems. The hub location problems have found wide application in physical planning of transport and telecommunication systems, especially systems of fast delivery, networks of logistic and distribution centres and cargo traffic terminals of the big cities, etc. The paper defines single and multiple allocations and studies the numerical examples. The capacitated single allocation hub location problems have been studied, with the provision of a mathematical model of selecting the location for the hubs on the network. The paper also presents the differences in the possibilities of implementing the exact and heuristic methods to solve the actual location problems of big dimensions i.e. hub problems of the big cities.

  8. Gasification of bio-oil: Effects of equivalence ratio and gasifying agents on product distribution and gasification efficiency.

    Science.gov (United States)

    Zheng, Ji-Lu; Zhu, Ming-Qiang; Wen, Jia-Long; Sun, Run-Cang

    2016-07-01

    Bio-oil derived from fast pyrolysis of rice husk was gasified for producing gas. The effectiveness of equivalence ratio and gasifying agents on the gas composition, ratio of H2/CO, tar amount, low heating value, degree of oxidation and cold gas efficiency of the gas were comprehensively investigated. Under different equivalence ratios and gasifying agents, the gases can be used as synthesis gas for Fischer-Tropsch synthesis, fuel gas for gas turbines in a power plant and reducing gas for ore reduction, respectively. The H2 concentration, CO level and cold gas efficiency of the resulted gas derived from gasification of bio-oil were significantly higher, while tar content was remarkably lower than those derived from gasification of solid biomass using the same equivalent ratio value and gasifying agent. In short, bio-oil gasification is economically feasible for large scale production of fuels and chemicals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Optimal Locations of Bus Stops Connecting Subways near Urban Intersections

    Directory of Open Access Journals (Sweden)

    Yuan Cui

    2015-01-01

    Full Text Available Unsuitable locations of bus stops which provide feeder transportation connecting subways near urban intersections usually lead to the low efficiency of public transport and level of passenger service. A multiobjective optimization model to distribute such stop locations is proposed to attain the shortest total walk distance of passengers and minimum delay time of cars through intersections and travel time of buses. The Pareto frontier and optimal solutions for the proposed model are given by the distance-based and enumerative methods. The Xizhimen bus stop is selected to implement case studies for verifying the validity of the proposed model. The analysis of sensitivity on possible solutions is also carried out in the case studies. The results show that the proposed model is capable of optimizing the locations of bus stops connecting subways near intersections and helpful to improve the level of passengers service and operational efficiency of public transportation.

  10. Efficient use of an improved radiative transfer code to simulate near-global distributions of satellite-measured radiances.

    Science.gov (United States)

    Nakajima, Takashi Y; Murakami, Hiroshi; Hori, Masahiro; Nakajima, Teruyuki; Aoki, Teruo; Oishi, Tomohiko; Tanaka, Akihiko

    2003-06-20

    Two new extension modules that give the water-leaving radiance from the ocean and the snow bidirectional reflectance distribution function were implemented in the latest radiative transfer code. In addition, to simulate the near-global distributions of satellite-measured radiances by using the improved radiative transfer code, we tested and applied the look-up table method together with the process-separation technique of the radiative transfer calculation. The computing time was reduced from 1 year to 20 s to simulate one channel, one scene of the Global Imager image by use of an Alpha 21164A-2 (600-MHz) machine. The error analyses showed that the radiances were simulated with less than 1% error for the nonabsorbing visible channels and approximately 2% error for absorbing channels by use of this method.

  11. A Physicochemical Study of the Effects of Acidity on the Distribution and Antioxidant Efficiency of Trolox in Olive Oil-in-Water Emulsions.

    Science.gov (United States)

    Galan, Anna; Losada-Barreiro, Sonia; Bravo-Díaz, Carlos

    2016-01-18

    The efficiency of antioxidants to inhibit the oxidation of lipid-based emulsions depends on several factors including their nature and their concentration at the reaction site. Here, we have analyzed the effects of acidity and of surfactant concentration on the distribution and efficiency of the vitamin E analog Trolox (TR) in stripped olive oil-in-water emulsions stabilized with Tween 20. The distribution was assessed in the intact emulsions by employing a kinetic method that exploits the reaction between the hydrophobic 4-hexadecylbenzenediazonium ions and TR. Kinetic results are interpreted on the grounds of the pseudophase model. The effects of TR on the oxidative stability of the emulsion were determined at different pH values by monitoring the formation of conjugated dienes over time. The results show that the efficiency of TR increases upon increasing pH even though its concentration in the interfacial region decreases. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Methodology for locating faults in the Eastern distribution system PDVSA, Punta de Mata and Furrial Divisions; Metodologia para la localizacion de fallas en el sistema de distribucion de PDVSA Oriente, Divisiones Punta de Mata y Furrial

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, F [Universidad Nacional Experimental Politecnica, Antonio Jose de Sucre, Guayana, Bolivar (Venezuela)]. E-mail: fco_martinez@outlook.com; Vasquez, C [Petroleos de Venezuela S.A., Maturin, Monagas (Venezuela)]. E-mail: vasquezcp@pdvsa.com

    2013-03-15

    Fault location in distribution systems has received a lot of attention in recent years in order to increase the availability of electricity supply. Due to the characteristics of distribution networks, fault location is a complicated task, so methods have been developed based on the variation of current and voltage values measured at the source substation, in normal operating condition and under the occurrence of short circuits. This article presents the implementation in MATLAB of a fault location algorithm applied to distribution systems, based on graphical analysis of the fault reactance which is determined by the minimum value of the reactance, using serial impedance matrix and fault/prefault voltage and current metering. Developed Tool Accuracy was verified by comparing the results obtained through it with actual recorded event data (Multilin SR 760) and distance to a known failure point. Additionally the method was applied to an experimental case that was compared with network fault simulation using ETAP Software. For both evaluated cases, the absolute error did not exceed 7%. [Spanish] La localizacion de fallas en sistemas de distribucion ha recibido atencion en los ultimos anos con el fin de aumentar la disponibilidad del suministro de energia electrica. Debido a las caracteristicas propias de las redes de distribucion, la ubicacion de fallas resulta una tarea complicada, por lo que se han desarrollado metodos basados en la variacion de los valores de corriente y voltaje medidos en la subestacion fuente, en condicion normal de operacion y ante la ocurrencia de cortocircuitos. Este articulo presenta la implementacion en MATLAB de un algoritmo de localizacion de fallas en sistemas de distribucion que se fundamenta en el analisis grafico de la reactancia de falla, mediante el cual se determina el minimo valor de la reactancia, utilizando la matriz de impedancia serie y la medicion de los voltajes y corrientes de prefalla y falla. Se verifico la precision de la

  13. Ultramicroporous carbon with extremely narrow pore distribution and very high nitrogen doping for efficient methane mixture gases upgrading

    KAUST Repository

    Yao, Kexin

    2017-06-24

    It is notably challenging to fabricate heavily heteroatom-doped porous carbonaceous materials with narrow ultramicropore size distributions for highly effective mixed-gas separation. In this study, new carbon-based materials with narrow ultramicropore size (<7 Å) distributions (>95%) and high N doping contents (>10 at%) are fabricated through the pyrolysis of a perchloro-substituted porous covalent triazine-based framework (ClCTF). In particular, the sample prepared at 650 °C (ClCTF-1-650) possesses the highest ultramicropores content (98%) and large N content (12 at%) and demonstrates a very high CH and CO capacity, as well as a low N uptake under ambient conditions. The extraordinarily high CH/N and CO/N selectivities correlate with both the ideal adsorption solution theory (IAST) method and performed dynamic separation experiments (breakthrough experiments). The results reported in this study far exceed the CH/N and CO/N selectivities of previously reported carbon-based adsorbents including various nitrogen-doped ones. These results are believed to be associated with the unusually high N content, as well as the suitably narrow ultramicropore size distribution. This report introduces a new pathway to design porous absorbents with precisely controlled ultramicropores for gas separation.

  14. Global diffuse distribution in the brain and efficient gene delivery to the dorsal root ganglia by intrathecal injection of adeno-associated viral vector serotype 1.

    Science.gov (United States)

    Iwamoto, Naotaka; Watanabe, Atsushi; Yamamoto, Motoko; Miyake, Noriko; Kurai, Toshiyuki; Teramoto, Akira; Shimada, Takashi

    2009-06-01

    The success of gene therapy for inherited neurodegenerative diseases such as metachromatic leukodystrophy (MLD) depends on the development of efficient gene delivery throughout the brain guarded by the blood-brain barrier and achieves distribution of the deficient enzyme throughout the brain. Direct injection of viral vector into the brain parenchyma is too invasive and may not be sufficient to treat the entire brain. As an alternative approach, we examined the feasibility of intrathecal (IT) injection of adeno-associated viral vector serotype 1 (AAV1). AAV1 vector expressing arylsulfatase A (ASA) and green fluorescence protein (GFP) was intrathecally injected into ASA knockout MLD model mice. Expression of GFP was assessed by fluorescence microscopy and immunohistochemical methods, whereas the concentration of ASA was determined by a quantitative enzyme-linked immunosorbent assay. Broad distribution of GFP expression was seen throughout the brain after IT injection of AAV1 vector. In addition, a large number of nerve fibers in the dorsal spinal cord and many neural cell bodies in the dorsal root ganglia were efficiently transduced. Widespread distribution of ASA activity and a significant reduction of sulfatide content were confirmed in treated MLD model mice. IT injection of AAV1 vector is a useful and non-invasive method for widespread gene delivery to the brain and dorsal root ganglia. (c) 2009 John Wiley & Sons, Ltd.

  15. An algorithm for LQ optimal actuator location

    Science.gov (United States)

    Darivandi, Neda; Morris, Kirsten; Khajepour, Amir

    2013-03-01

    The locations of the control hardware are typically a design variable in controller design for distributed parameter systems. In order to obtain the most efficient control system, the locations of control hardware as well as the feedback gain should be optimized. These optimization problems are generally non-convex. In addition, the models for these systems typically have a large number of degrees of freedom. Consequently, existing optimization schemes for optimal actuator placement may be inaccurate or computationally impractical. In this paper, the feedback control is chosen to be an optimal linear quadratic regulator. The optimal actuator location problem is reformulated as a convex optimization problem. A subgradient-based optimization scheme which leads to the global solution of the problem is used to optimize actuator locations. The optimization algorithm is applied to optimize the placement of piezoelectric actuators in vibration control of flexible structures. This method is compared with a genetic algorithm, and is observed to be faster and more accurate. Experiments are performed to verify the efficacy of optimal actuator placement.

  16. Efficient up-conversion in Yb:Er:NaT(XO42 thermal nanoprobes. Imaging of their distribution in a perfused mouse.

    Directory of Open Access Journals (Sweden)

    Carlos Zaldo

    Full Text Available Yb and Er codoped NaT(XO42 (T = Y, La, Gd, Lu and X = Mo, W disordered oxides show a green (Er3+ related up-conversion (UC efficiency comparable to that of Yb:Er:β-NaYF4 compound and unless 3 times larger UC ratiometric thermal sensitivity. The similar UC efficiency of Yb:Er doped NaT(XO42 and β-NaYF4 compounds allowed testing equal subcutaneous depths of ex-vivo chicken tissue in both cases. This extraordinary behavior for NaT(XO42 oxides with large cutoff phonon energy (ħω≈ 920 cm-1 is ascribed to 4F9/2 electron population recycling to higher energy 4G11/2 level by a phonon assisted transition. Crystalline nanoparticles of Yb:Er:NaLu(MoO42 have been synthesized by sol-gel with sizes most commonly in the 50-80 nm range, showing a relatively small reduction of the UC efficiency with regards to bulk materials. Fluorescence lifetime and multiphoton imaging microscopies show that these nanoparticles can be efficiently distributed to all body organs of a perfused mouse.

  17. Pressure Transducer Locations

    Data.gov (United States)

    National Aeronautics and Space Administration — Files are located here, defining the locations of the pressure transducers on the HIRENASD model. These locations also correspond to the locations that analysts...

  18. Enhancing the Light-Extraction Efficiency of AlGaN Nanowires Ultraviolet Light-Emitting Diode by using Nitride/Air Distributed Bragg Reflector Nanogratings

    KAUST Repository

    Alias, Mohd Sharizal

    2017-09-11

    The performance and efficiency of AlGaN ultraviolet light-emitting diodes have been limited by the extremely low light-extraction efficiency (LEE) due to the intrinsic material properties of AlGaN. Here, to enhance the LEE of the device, we demonstrate an AlGaN nanowires light-emitting diode (NWs-LED) integrated with nitride/air Distributed Bragg Reflector (DBR) nanogratings. Compared to a control device (only mesa), the AlGaN NWs-LED with the nitride/air DBR nanogratings exhibit enhancement in the light output power and external quantum efficiency (EQE) by a factor of ∼1.67. The higher light output power and EQE are attributed mainly to the multiple reflectances laterally for the transverse magnetic (TM)-polarized light and scattering introduced by the nanogratings. To further understand the LEE enhancement, the electrical field distribution, extraction ratio and polar pattern of the AlGaN NWs-LED with and without the nitride/air DBR nanogratings were analyzed using the finite-difference-time-domain method. It was observed that the TM-field emission was confined and scattered upward whereas the polar pattern was intensified for the AlGaN NWs-LED with the nanogratings. Our approach to enhance the LEE via the nitride/air DBR nanogratings can provide a promising route for increasing the efficiency of AlGaN-based LEDs, also, to functioning as facet mirror for AlGaN-based laser diodes.

  19. An efficient hybrid evolutionary algorithm based on PSO and HBMO algorithms for multi-objective Distribution Feeder Reconfiguration

    Energy Technology Data Exchange (ETDEWEB)

    Niknam, Taher [Electronic and Electrical Engineering Department, Shiraz University of Technology, Shiraz (Iran)

    2009-08-15

    This paper introduces a robust searching hybrid evolutionary algorithm to solve the multi-objective Distribution Feeder Reconfiguration (DFR). The main objective of the DFR is to minimize the real power loss, deviation of the nodes' voltage, the number of switching operations, and balance the loads on the feeders. Because of the fact that the objectives are different and no commensurable, it is difficult to solve the problem by conventional approaches that may optimize a single objective. This paper presents a new approach based on norm3 for the DFR problem. In the proposed method, the objective functions are considered as a vector and the aim is to maximize the distance (norm2) between the objective function vector and the worst objective function vector while the constraints are met. Since the proposed DFR is a multi objective and non-differentiable optimization problem, a new hybrid evolutionary algorithm (EA) based on the combination of the Honey Bee Mating Optimization (HBMO) and the Discrete Particle Swarm Optimization (DPSO), called DPSO-HBMO, is implied to solve it. The results of the proposed reconfiguration method are compared with the solutions obtained by other approaches, the original DPSO and HBMO over different distribution test systems. (author)

  20. Distributing and storing required data efficiently by means of specifically tailored data formats in the ATLAS collaboration

    CERN Document Server

    Köneke, K; The ATLAS collaboration

    2010-01-01

    With the start of the LHC physics program, the ATLAS experiment started to record vast amounts of data. This data has to be distributed and stored on the world-wide computing grid in a smart way in order to enable an e®ective and e±cient analysis by physicists. There are in principle two classes of analysis that are required. In the commissioning phase of the ATLAS experiment, low{level Event Sum- mary Data (ESD), the result of the event reconstruction, has to be an- alyzed to evaluate the performance of the individual subdetectors, the performance of the reconstruction and particle identi¯cation algorithms, and to obtain calibration coe±cients. For later physics analysis, it is usu- ally su±cient to use the less detailed Analysis Object Data (AOD), which is a less-detailed version of the ESD. In the grid model of distributed analysis, these data must be trans- ferred to Tier-2 sites before they can be analyzed. However, the large size of ESD ('1 MByte/event) constrains the amount of detailed data that c...

  1. Single-longitudinal mode distributed-feedback fiber laser with low-threshold and high-efficiency

    Science.gov (United States)

    Jiang, Man; Zhou, Pu; Gu, Xijia

    2018-01-01

    Single-frequency fiber laser has attracted a lot of interest in recent years due to its numerous application potentials in telecommunications, LIDAR, high resolution sensing, atom frequency standard, etc. Phosphate glass fiber is one of the candidates for building compact high gain fiber lasers because of its capability of high-concentration of rare-earth ions doping in fiber core. Nevertheless, it is challenging for the integration of UV-written intra-core fiber Bragg gratings into the fiber laser cavity due to the low photosensitivity of phosphate glass fiber. The research presented in this paper will focus on demonstration of UV-written Bragg gratings in phosphate glass fiber and its application in direct-written short monolithic single-frequency fiber lasers. Strong π-phase shift Bragg grating structure is direct-inscribed into the Er/Yb co-doped gain fiber using an excimer laser, and a 5-cm-long phase mask is used to inscribe a laser cavity into the Er/Yb co-doped phosphate glass fibers. The phase mask is a uniform mask with a 50 μm gap in the middle. The fiber laser device emits output power of 10.44 mW with a slope efficiency of 21.5% and the threshold power is about 42.8 mW. Single-longitudinal mode operation is validated by radio frequency spectrum measurement. Moreover, the output spectrum at the highest power shows an excellent optical signal to noise ratio of about 70 dB. These results, to the best of our knowledge, show the lowest power threshold and highest efficiency among the reports that using the same structure to achieve single-longitudinal mode laser output.

  2. On the Efficient Simulation of the Distribution of the Sum of Gamma-Gamma Variates with Application to the Outage Probability Evaluation Over Fading Channels

    KAUST Repository

    Ben Issaid, Chaouki

    2016-06-01

    The Gamma-Gamma distribution has recently emerged in a number of applications ranging from modeling scattering and reverbation in sonar and radar systems to modeling atmospheric turbulence in wireless optical channels. In this respect, assessing the outage probability achieved by some diversity techniques over this kind of channels is of major practical importance. In many circumstances, this is intimately related to the difficult question of analyzing the statistics of a sum of Gamma-Gamma random variables. Answering this question is not a simple matter. This is essentially because outage probabilities encountered in practice are often very small, and hence the use of classical Monte Carlo methods is not a reasonable choice. This lies behind the main motivation of the present work. In particular, this paper proposes a new approach to estimate the left tail of the sum of Gamma-Gamma variates. More specifically, we propose a mean-shift importance sampling scheme that efficiently evaluates the outage probability of L-branch maximum ratio combining diversity receivers over Gamma-Gamma fading channels. The proposed estimator satisfies the well-known bounded relative error criterion, a well-desired property characterizing the robustness of importance sampling schemes, for both identically and non-identically independent distributed cases. We show the accuracy and the efficiency of our approach compared to naive Monte Carlo via some selected numerical simulations.

  3. Multidistribution Center Location Based on Real-Parameter Quantum Evolutionary Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Huaixiao Wang

    2014-01-01

    Full Text Available To determine the multidistribution center location and the distribution scope of the distribution center with high efficiency, the real-parameter quantum-inspired evolutionary clustering algorithm (RQECA is proposed. RQECA is applied to choose multidistribution center location on the basis of the conventional fuzzy C-means clustering algorithm (FCM. The combination of the real-parameter quantum-inspired evolutionary algorithm (RQIEA and FCM can overcome the local search defect of FCM and make the optimization result independent of the choice of initial values. The comparison of FCM, clustering based on simulated annealing genetic algorithm (CSAGA, and RQECA indicates that RQECA has the same good convergence as CSAGA, but the search efficiency of RQECA is better than that of CSAGA. Therefore, RQECA is more efficient to solve the multidistribution center location problem.

  4. Modeling and experimental performance of an intermediate temperature reversible solid oxide cell for high-efficiency, distributed-scale electrical energy storage

    Science.gov (United States)

    Wendel, Christopher H.; Gao, Zhan; Barnett, Scott A.; Braun, Robert J.

    2015-06-01

    Electrical energy storage is expected to be a critical component of the future world energy system, performing load-leveling operations to enable increased penetration of renewable and distributed generation. Reversible solid oxide cells, operating sequentially between power-producing fuel cell mode and fuel-producing electrolysis mode, have the capability to provide highly efficient, scalable electricity storage. However, challenges ranging from cell performance and durability to system integration must be addressed before widespread adoption. One central challenge of the system design is establishing effective thermal management in the two distinct operating modes. This work leverages an operating strategy to use carbonaceous reactant species and operate at intermediate stack temperature (650 °C) to promote exothermic fuel-synthesis reactions that thermally self-sustain the electrolysis process. We present performance of a doped lanthanum-gallate (LSGM) electrolyte solid oxide cell that shows high efficiency in both operating modes at 650 °C. A physically based electrochemical model is calibrated to represent the cell performance and used to simulate roundtrip operation for conditions unique to these reversible systems. Design decisions related to system operation are evaluated using the cell model including current density, fuel and oxidant reactant compositions, and flow configuration. The analysis reveals tradeoffs between electrical efficiency, thermal management, energy density, and durability.

  5. Uptake and distribution of soil applied zinc by citrus trees-addressing fertilizer use efficiency with 68Zn labeling.

    Directory of Open Access Journals (Sweden)

    Franz Walter Rieger Hippler

    Full Text Available The zinc (Zn supply increases the fruit yield of Citrus trees that are grown, especially in the highly weathered soils of the tropics due to the inherently low nutrient availability in the soil solution. Leaf sprays containing micronutrients are commonly applied to orchards, even though the nutrient supply via soil could be of practical value. This study aimed to evaluate the effect of Zn fertilizers that are applied to the soil surface on absorption and partitioning of the nutrient by citrus trees. A greenhouse experiment was conducted with one-year-old sweet orange trees. The plants were grown in soils with different textures (18.1 or 64.4% clay that received 1.8 g Zn per plant, in the form of either ZnO or ZnSO4 enriched with the stable isotope 68Zn. Zinc fertilization increased the availability of the nutrient in the soil and the content in the orange trees. Greater responses were obtained when ZnSO4 was applied to the sandy loam soil due to its lower specific metal adsorption compared to that of the clay soil. The trunk and branches accumulated the most fertilizer-derived Zn (Zndff and thus represent the major reserve organ for this nutrient in the plant. The trees recovered up to 4% of the applied Zndff. Despite this relative low recovery, the Zn requirement of the trees was met with the selected treatment based on the total leaf nutrient content and increased Cu/Zn-SOD activity in the leaves. We conclude that the efficiency of Zn fertilizers depends on the fertilizer source and the soil texture, which must be taken into account by guidelines for fruit crop fertilization via soil, in substitution or complementation of traditional foliar sprays.

  6. High Efficiency Integrated Space Conditioning, Water Heating and Air Distribution System for HUD-Code Manufactured Housing

    Energy Technology Data Exchange (ETDEWEB)

    Henry DeLima; Joe Akin; Joseph Pietsch

    2008-09-14

    Recognizing the need for new space conditioning and water heating systems for manufactured housing, DeLima Associates assembled a team to develop a space conditioning system that would enhance comfort conditions while also reducing energy usage at the systems level. The product, Comboflair® was defined as a result of a needs analysis of project sponsors and industry stakeholders. An integrated system would be developed that would combine a packaged airconditioning system with a small-duct, high-velocity air distribution system. In its basic configuration, the source for space heating would be a gas water heater. The complete system would be installed at the manufactured home factory and would require no site installation work at the homesite as is now required with conventional split-system air conditioners. Several prototypes were fabricated and tested before a field test unit was completed in October 2005. The Comboflair® system, complete with ductwork, was installed in a 1,984 square feet, double-wide manufactured home built by Palm Harbor Homes in Austin, TX. After the home was transported and installed at a Palm Harbor dealer lot in Austin, TX, a data acquisition system was installed for remote data collection. Over 60 parameters were continuously monitored and measurements were transmitted to a remote site every 15 minutes for performance analysis. The Comboflair® system was field tested from February 2006 until April 2007. The cooling system performed in accordance with the design specifications. The heating system initially could not provide the needed capacity at peak heating conditions until the water heater was replaced with a higher capacity standard water heater. All system comfort goals were then met. As a result of field testing, we have identified improvements to be made to specific components for incorporation into production models. The Comboflair® system will be manufactured by Unico, Inc. at their new production facility in St. Louis

  7. An Efficient Method of Sharing Mass Spatio-Temporal Trajectory Data Based on Cloudera Impala for Traffic Distribution Mapping in an Urban City

    Directory of Open Access Journals (Sweden)

    Lianjie Zhou

    2016-10-01

    Full Text Available The efficient sharing of spatio-temporal trajectory data is important to understand traffic congestion in mass data. However, the data volumes of bus networks in urban cities are growing rapidly, reaching daily volumes of one hundred million datapoints. Accessing and retrieving mass spatio-temporal trajectory data in any field is hard and inefficient due to limited computational capabilities and incomplete data organization mechanisms. Therefore, we propose an optimized and efficient spatio-temporal trajectory data retrieval method based on the Cloudera Impala query engine, called ESTRI, to enhance the efficiency of mass data sharing. As an excellent query tool for mass data, Impala can be applied for mass spatio-temporal trajectory data sharing. In ESTRI we extend the spatio-temporal trajectory data retrieval function of Impala and design a suitable data partitioning method. In our experiments, the Taiyuan BeiDou (BD bus network is selected, containing 2300 buses with BD positioning sensors, producing 20 million records every day, resulting in two difficulties as described in the Introduction section. In addition, ESTRI and MongoDB are applied in experiments. The experiments show that ESTRI achieves the most efficient data retrieval compared to retrieval using MongoDB for data volumes of fifty million, one hundred million, one hundred and fifty million, and two hundred million. The performance of ESTRI is approximately seven times higher than that of MongoDB. The experiments show that ESTRI is an effective method for retrieving mass spatio-temporal trajectory data. Finally, bus distribution mapping in Taiyuan city is achieved, describing the buses density in different regions at different times throughout the day, which can be applied in future studies of transport, such as traffic scheduling, traffic planning and traffic behavior management in intelligent public transportation systems.

  8. High-efficiency grid-connected photovoltaic module integrated converter system with high-speed communication interfaces for small-scale distribution power generation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Woo-Young; Lai, Jih-Sheng (Jason) [Future Energy Electronics Center, Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA (United States)

    2010-04-15

    This paper presents a high-efficiency grid-connected photovoltaic (PV) module integrated converter (MIC) system with reduced PV current variation. The proposed PV MIC system consists of a high-efficiency step-up DC-DC converter and a single-phase full-bridge DC-AC inverter. An active-clamping flyback converter with a voltage-doubler rectifier is proposed for the step-up DC-DC converter. The proposed step-up DC-DC converter reduces the switching losses by eliminating the reverse-recovery current of the output rectifying diodes. To reduce the PV current variation introduced by the grid-connected inverter, a PV current variation reduction method is also suggested. The suggested PV current variation reduction method reduces the PV current variation without any additional components. Moreover, for centralized power control of distributed PV MIC systems, a PV power control scheme with both a central control level and a local control level is presented. The central PV power control level controls the whole power production by sending out reference power signals to each individual PV MIC system. The proposed step-up DC-DC converter achieves a high-efficiency of 97.5% at 260 W output power to generate the DC-link voltage of 350 V from the PV voltage of 36.1 V. The PV MIC system including the DC-DC converter and the DC-AC inverter achieves a high-efficiency of 95% with the PV current ripple less than 3% variation of the rated PV current. (author)

  9. How Efficient are Agitators in Biogas Digesters? Determination of the Efficiency of Submersible Motor Mixers and Incline Agitators by Measuring Nutrient Distribution in Full-Scale Agricultural Biogas Digesters

    Directory of Open Access Journals (Sweden)

    Andreas Lemmer

    2013-12-01

    Full Text Available The goal of this work was to evaluate the efficiency of two different agitation systems by measuring the nutrient distribution in a digester fed with renewable energy crops and animal manure. The study was carried out at the practical research biogas plant of Hohenheim University. A unique probe sampling system has been developed that allows probe sampling from the top of the concrete roof into different parts and heights of the digester. The samples were then analyzed in the laboratory for natural fatty acids concentrations. Three different agitation setups were chosen for evaluation at continuous stirring and feeding procedures. The results showed that the analysis approach for agitator optimization through direct measurement of the nutrients distribution in the digester is promising. The type of the agitators and the agitation regime showed significant differences on local concentrations of organic acids, which are not correlated to the dry matter content. Simultaneous measurements on electric energy consumption of the different agitator types verify that by using the slow-moving incline agitator with large propeller diameters in favor of the fast-moving submersible mixer with smaller propeller diameters, the savings potential rises up to 70% by maintaining the mixing quality.

  10. Efficient generation of 1.9  W yellow light by cascaded frequency doubling of a distributed Bragg reflector tapered diode

    DEFF Research Database (Denmark)

    Hansen, Anders Kragh; Christensen, Mathias; Noordegraaf, Danny

    2016-01-01

    Watt-level yellow emitting lasers are interesting for medical applications, due to their high hemoglobin absorption, and for efficient detection of certain fluorophores. In this paper, we demonstrate a compact and robust diode-based laser system in the yellow spectral range. The system generates 1.......9 W of single-frequency light at 562.4 nm by cascaded single-pass frequency doubling of the 1124.8 nm emission from a distributed Bragg reflector (DBR) tapered laser diode. The absence of a free-space cavity makes the system stable over a base-plate temperature range of 30 K. At the same time, the use...... of a laser diode enables the modulation of the pump wavelength by controlling the drive current. This is utilized to achieve a power modulation depth above 90% for the second harmonic light, with a rise time below 40  μs....

  11. Peptide Dendrimer/Lipid Hybrid Systems Are Efficient DNA Transfection Reagents: Structure–Activity Relationships Highlight the Role of Charge Distribution Across Dendrimer Generations

    Science.gov (United States)

    2013-01-01

    Efficient DNA delivery into cells is the prerequisite of the genetic manipulation of organisms in molecular and cellular biology as well as, ultimately, in nonviral gene therapy. Current reagents, however, are relatively inefficient, and structure–activity relationships to guide their improvement are hard to come by. We now explore peptide dendrimers as a new type of transfection reagent and provide a quantitative framework for their evaluation. A collection of dendrimers with cationic and hydrophobic amino acid motifs (such as KK, KA, KH, KL, and LL) distributed across three dendrimer generations was synthesized by a solid-phase protocol that provides ready access to dendrimers in milligram quantities. In conjunction with a lipid component (DOTMA/DOPE), the best reagent, G1,2,3-KL ((LysLeu)8(LysLysLeu)4(LysLysLeu)2LysGlySerCys-NH2), improves transfection by 6–10-fold over commercial reagents under their respective optimal conditions. Emerging structure–activity relationships show that dendrimers with cationic and hydrophobic residues distributed in each generation are transfecting most efficiently. The trigenerational dendritic structure has an advantage over a linear analogue worth up to an order of magnitude. The success of placing the decisive cationic charge patterns in inner shells rather than previously on the surface of macromolecules suggests that this class of dendrimers significantly differs from existing transfection reagents. In the future, this platform may be tuned further and coupled to cell-targeting moieties to enhance transfection and cell specificity. PMID:23682947

  12. Automatic location of short circuit faults

    Energy Technology Data Exchange (ETDEWEB)

    Lehtonen, M. [VTT Energy, Espoo (Finland); Hakola, T.; Antila, E. [ABB Power Oy, Helsinki (Finland); Seppaenen, M. [North-Carelian Power Company (Finland)

    1996-12-31

    In this presentation, the automatic location of short circuit faults on medium voltage distribution lines, based on the integration of computer systems of medium voltage distribution network automation is discussed. First the distribution data management systems and their interface with the substation telecontrol, or SCADA systems, is studied. Then the integration of substation telecontrol system and computerised relay protection is discussed. Finally, the implementation of the fault location system is presented and the practical experience with the system is discussed

  13. Automatic location of short circuit faults

    Energy Technology Data Exchange (ETDEWEB)

    Lehtonen, M. [VTT Energy, Espoo (Finland); Hakola, T.; Antila, E. [ABB Power Oy (Finland); Seppaenen, M. [North-Carelian Power Company (Finland)

    1998-08-01

    In this chapter, the automatic location of short circuit faults on medium voltage distribution lines, based on the integration of computer systems of medium voltage distribution network automation is discussed. First the distribution data management systems and their interface with the substation telecontrol, or SCADA systems, is studied. Then the integration of substation telecontrol system and computerized relay protection is discussed. Finally, the implementation of the fault location system is presented and the practical experience with the system is discussed

  14. The ANEEL and the criteria for the resource application in energy efficiency of the electric energy distribution companies; A ANEEL e os criterios para aplicacao de recursos em programas de eficiencia energetica das distribuidoras de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Jamil [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Inst. de Sistemas Eletrico e Energia. Grupo de Estudos Energeticos (GEE)]. E-mail: jamil@unifei.edu.br

    2006-07-01

    Each year the ANEEL establishes the criteria for the of the Energy Efficiency Programs of the electric power distribution companies. This subject has an importance nevertheless to be highlighted only when conjunctural circumstances occur such as the 2001/2002 electric energy crisis. Such characteristics increase the ANEEL responsibility, because the regulation must observe the structural character which performs the energy efficiency actions. Recently, the ANEEL altered the criteria for the resource application by the electric power distribution companies. This article describes the importance of the energy efficiency and make comments on these frequent regulatory changes. (author)

  15. On the Efficient Simulation of the Distribution of the Sum of Gamma-Gamma Variates with Application to the Outage Probability Evaluation Over Fading Channels

    KAUST Repository

    Ben Issaid, Chaouki

    2017-01-26

    The Gamma-Gamma distribution has recently emerged in a number of applications ranging from modeling scattering and reverberation in sonar and radar systems to modeling atmospheric turbulence in wireless optical channels. In this respect, assessing the outage probability achieved by some diversity techniques over this kind of channels is of major practical importance. In many circumstances, this is related to the difficult question of analyzing the statistics of a sum of Gamma- Gamma random variables. Answering this question is not a simple matter. This is essentially because outage probabilities encountered in practice are often very small, and hence the use of classical Monte Carlo methods is not a reasonable choice. This lies behind the main motivation of the present work. In particular, this paper proposes a new approach to estimate the left tail of the sum of Gamma-Gamma variates. More specifically, we propose robust importance sampling schemes that efficiently evaluates the outage probability of diversity receivers over Gamma-Gamma fading channels. The proposed estimators satisfy the well-known bounded relative error criterion for both maximum ratio combining and equal gain combining cases. We show the accuracy and the efficiency of our approach compared to naive Monte Carlo via some selected numerical simulations.

  16. Efficient calculation of potential distribution in two-layer earth; Niso kozo daichikei ni okeru denki tansa no tame no koritsuteki den`i keisan shuho

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, M.; Okamoto, Y. [Chiba Institute of Technology, Chiba (Japan); Endo, M.; Noguchi, K. [Waseda University, Tokyo (Japan); Teramachi, Y.; Akabane, H. [University of Industrial Technology, Kanagawa (Japan); Agu, M. [Ibaraki University, Ibaraki (Japan)

    1997-05-27

    An efficient calculation method of potential distribution in the presence of an embedded body in multi-layer earth has been proposed by expanding the method of image with a consideration of multiple reflection between the ground surface and each underground boundary. For this method, when solving boundary integral equation with the potential of embedded body surface as only one unknown, i.e., when obtaining discretization equation, ordinary boundary element program developed for analyzing the finite closed region can be used. As an example, numerical calculation was conducted for the two-layer earth. The analysis expression of potential distribution in the case of the certain embedded body in two-layer earth has never published. Accordingly, the calculated results were compared with those by the integral equation method. As a result, it was concluded that the primary potential obtained from the present method agreed well with that obtained from the integral equation method. However, there was a disregarded difference in the secondary potential. For confirming the effectiveness, it was necessary to compare with another numerical calculation method, such as finite element method. 5 refs., 5 figs.

  17. Study on Dissemination Patterns in Location-Aware Gossiping Networks

    Science.gov (United States)

    Kami, Nobuharu; Baba, Teruyuki; Yoshikawa, Takashi; Morikawa, Hiroyuki

    We study the properties of information dissemination over location-aware gossiping networks leveraging location-based real-time communication applications. Gossiping is a promising method for quickly disseminating messages in a large-scale system, but in its application to information dissemination for location-aware applications, it is important to consider the network topology and patterns of spatial dissemination over the network in order to achieve effective delivery of messages to potentially interested users. To this end, we propose a continuous-space network model extended from Kleinberg's small-world model applicable to actual location-based applications. Analytical and simulation-based study shows that the proposed network achieves high dissemination efficiency resulting from geographically neutral dissemination patterns as well as selective dissemination to proximate users. We have designed a highly scalable location management method capable of promptly updating the network topology in response to node movement and have implemented a distributed simulator to perform dynamic target pursuit experiments as one example of applications that are the most sensitive to message forwarding delay. The experimental results show that the proposed network surpasses other types of networks in pursuit efficiency and achieves the desirable dissemination patterns.

  18. Models for disaster relief shelter location and supply routing.

    Science.gov (United States)

    2013-01-01

    This project focuses on the development of a natural disaster response planning model that determines where to locate points of distribution for relief supplies after a disaster occurs. Advance planning (selecting locations for points of distribution...

  19. Multi-Unit Facility Location Games

    OpenAIRE

    Ben-Porat, Omer; Tennenholtz, Moshe

    2016-01-01

    Motivated by applications in clustering and information retrieval, we extend the classical Hotelling setting to deal with multi-facility location duels. In the classical Hotelling setting, customers' locations are taken from the uniform distribution on the $[0,1]$ segment, and there are two facility owners, each needs to decide on the location of her (single) facility, aiming to maximize the proportion of customers closer to it. We extend the Hotelling setting to multi-unit facility location ...

  20. Development of efficient and cost-effective distributed hydrological modeling tool MWEasyDHM based on open-source MapWindow GIS

    Science.gov (United States)

    Lei, Xiaohui; Wang, Yuhui; Liao, Weihong; Jiang, Yunzhong; Tian, Yu; Wang, Hao

    2011-09-01

    Many regions are still threatened with frequent floods and water resource shortage problems in China. Consequently, the task of reproducing and predicting the hydrological process in watersheds is hard and unavoidable for reducing the risks of damage and loss. Thus, it is necessary to develop an efficient and cost-effective hydrological tool in China as many areas should be modeled. Currently, developed hydrological tools such as Mike SHE and ArcSWAT (soil and water assessment tool based on ArcGIS) show significant power in improving the precision of hydrological modeling in China by considering spatial variability both in land cover and in soil type. However, adopting developed commercial tools in such a large developing country comes at a high cost. Commercial modeling tools usually contain large numbers of formulas, complicated data formats, and many preprocessing or postprocessing steps that may make it difficult for the user to carry out simulation, thus lowering the efficiency of the modeling process. Besides, commercial hydrological models usually cannot be modified or improved to be suitable for some special hydrological conditions in China. Some other hydrological models are open source, but integrated into commercial GIS systems. Therefore, by integrating hydrological simulation code EasyDHM, a hydrological simulation tool named MWEasyDHM was developed based on open-source MapWindow GIS, the purpose of which is to establish the first open-source GIS-based distributed hydrological model tool in China by integrating modules of preprocessing, model computation, parameter estimation, result display, and analysis. MWEasyDHM provides users with a friendly manipulating MapWindow GIS interface, selectable multifunctional hydrological processing modules, and, more importantly, an efficient and cost-effective hydrological simulation tool. The general construction of MWEasyDHM consists of four major parts: (1) a general GIS module for hydrological analysis, (2) a

  1. Stochastic dominance theory for location-scale family

    Directory of Open Access Journals (Sweden)

    Wing-Keung Wong

    2006-01-01

    Full Text Available Meyer (1987 extended the theory of mean-variance criterion to include the comparison among distributions that differ only by location and scale parameters and to include general utility functions with only convexity or concavity restrictions. In this paper, we make some comments on Meyer's paper and extend the results from Tobin (1958 that the indifference curve is convex upwards for risk averters, concave downwards for risk lovers, and horizontal for risk neutral investors to include the general conditions stated by Meyer (1987. We also provide an alternative proof for the theorem. Levy (1989 extended Meyer's results by introducing some inequality relationships between the stochastic-dominance and the mean-variance efficient sets. In this paper, we comment on Levy's findings and show that these relationships do not hold in certain situations. We further develop some properties among the first- and second-degree stochastic dominance efficient sets and the mean-variance efficient set.

  2. Residential Location, Job Location, and Wages: Theory and Empirics

    DEFF Research Database (Denmark)

    Vejlin, Rune Majlund

    I develop a stylized partial on-the-job equilibrium search model which incorporate a spatial dimension. Workers reside on a circle and can move at a cost. Each point on the circle has a wage distribution. Implications about wages and job mobility are drawn from the model and tested on Danish...... matched employer-employee data. The model predictions hold true. I find that workers working farther away from their residence earn higher wages. When a worker is making a job-to-job transition where he changes workplace location he experiences a higher wage change than a worker making a job-to-job...... transition without changing workplace location. However, workers making a job-to-job transition which makes the workplace location closer to the residence experiences a wage drop. Furthermore, low wage workers and workers with high transportation costs are more likely to make job-to-job transitions, but also...

  3. Law Enforcement Locations

    Data.gov (United States)

    Kansas Data Access and Support Center — Law Enforcement Locations in Kansas Any location where sworn officers of a law enforcement agency are regularly based or stationed. Law enforcement agencies "are...

  4. Muscle glycogen and cell function - Location, location, location

    DEFF Research Database (Denmark)

    Ørtenblad, N; Nielsen, Joachim

    2015-01-01

    that the subcellular localization of glycogen has to be considered to fully understand the role of glycogen metabolism and signaling in skeletal muscle function. Here, we propose that the effect of low muscle glycogen on excitation-contraction coupling may serve as a built-in mechanism, which links the energetic state......The importance of glycogen, as a fuel during exercise, is a fundamental concept in exercise physiology. The use of electron microscopy has revealed that glycogen is not evenly distributed in skeletal muscle fibers, but rather localized in distinct pools. In this review, we present the available...... evidence regarding the subcellular localization of glycogen in skeletal muscle and discuss this from the perspective of skeletal muscle fiber function. The distribution of glycogen in the defined pools within the skeletal muscle varies depending on exercise intensity, fiber phenotype, training status...

  5. Shapley Facility Location Games

    OpenAIRE

    Ben-Porat, Omer; Tennenholtz, Moshe

    2017-01-01

    Facility location games have been a topic of major interest in economics, operations research and computer science, starting from the seminal work by Hotelling. Spatial facility location models have successfully predicted the outcome of competition in a variety of scenarios. In a typical facility location game, users/customers/voters are mapped to a metric space representing their preferences, and each player picks a point (facility) in that space. In most facility location games considered i...

  6. Location, Location, Location: Where Do Location-Based Services Fit into Your Institution's Social Media Mix?

    Science.gov (United States)

    Nekritz, Tim

    2011-01-01

    Foursquare is a location-based social networking service that allows users to share their location with friends. Some college administrators have been thinking about whether and how to take the leap into location-based services, which are also known as geosocial networking services. These platforms, which often incorporate gaming elements like…

  7. Location, location, location: the BRMS1 protein and melanoma progression

    Directory of Open Access Journals (Sweden)

    Riker Adam I

    2012-02-01

    Full Text Available Abstract The metastasis suppressor, BRMS1, has been demonstrated to cause dramatic regression of metastatic lesions without blocking orthotopic tumor growth. The role of BRMS1 is well-documented for several non-melanoma malignancies, such as breast cancer, ovarian cancer and non-small-cell lung cancer. However, its role in melanoma is just beginning to be understood, with a recent article by Slipicevic et al. highlighting the levels of expression of BRMS1 in benign nevi, primary and metastatic melanoma samples. Their findings emphasize that the intracellular location of BRMS1 protein (cytoplasmic or nuclear, appears to have a significant impact upon the metastatic capacity of melanoma cells. Interestingly, this selective localization translates into a statistically significant decrease in the relapse-free period in melanoma patients, further associated with a thicker Breslow's depth of primary melanomas. However, and more importantly, this study begins to define a clearer role for BRMS1 in melanoma that is strictly dependent upon its cellular location, with nuclear expression associated with invasive and metastatic capacity and cytoplasmic expression resulting in repressive effects upon progression and metastasis. Please see related article: http://www.biomedcentral.com/1471-2407/12/73

  8. Arbitrary mandibular hinge axis locations.

    Science.gov (United States)

    Simpson, J W; Hesby, R A; Pfeifer, D L; Pelleu, G B

    1984-06-01

    This study compared selected arbitrary hinge axis locations with the kinematic axis location. Fifty subjects were studied, and the data were statistically analyzed. Results showed significant differences between the location of experimental arbitrary axis point and those of Beyron, Gysi, and Bergstrom in relation to the kinematic axis. The arbitrary points of Beyron, Gysi, and Bergstrom showed directional tendencies, whereas the experimental arbitrary points were evenly distributed around the kinematic axis. This study indicates that the experimental arbitrary axis point more closely and consistently approximated the kinematic axis than the arbitrary points of Beyron, Gysi, and Bergstrom. The finding suggests that the clinical use of a point on Camper's line, 10 mm from the superior border of the tragus, results in a more accurate transfer of the maxillary cast to the articulator.

  9. Smartphones as locative media

    CERN Document Server

    Frith, Jordan

    2015-01-01

    Smartphone adoption has surpassed 50% of the population in more than 15 countries, and there are now more than one million mobile applications people can download to their phones. Many of these applications take advantage of smartphones as locative media, which is what allows smartphones to be located in physical space. Applications that take advantage of people's location are called location-based services, and they are the focus of this book. Smartphones as locative media raise important questions about how we understand the complicated relationship between the Internet and physical space

  10. Noise Source Location Optimization

    Directory of Open Access Journals (Sweden)

    Ed O’Keefe

    1994-01-01

    Full Text Available This article describes a method to determine locations of noise sources that minimize modal coupling in complex acoustic volumes. Using the acoustic source scattering capabilities of the boundary element method, predictions are made of mode shape and pressure levels due to various source locations. Combining knowledge of the pressure field with a multivariable function minimization technique, the source location generating minimum pressure levels can be determined. The analysis also allows for an objective comparison of “best/worst” locations. The technique was implemented on a personal computer for the U.S. Space Station, predicting 5–10 dB noise reduction using optimum source locations.

  11. Pre-aggregation for Probability Distributions

    DEFF Research Database (Denmark)

    Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach

    Motivated by the increasing need to analyze complex uncertain multidimensional data (e.g., in order to optimize and personalize location-based services), this paper proposes novel types of {\\em probabilistic} OLAP queries that operate on aggregate values that are probability distributions...... and the techniques to process these queries. The paper also presents the methods for computing the probability distributions, which enables pre-aggregation, and for using the pre-aggregated distributions for further aggregation. In order to achieve good time and space efficiency, the methods perform approximate...... multidimensional data analysis that is considered in this paper (i.e., approximate processing of probabilistic OLAP queries over probability distributions)....

  12. Rationale behind the optimum efficiency of columns packed with new 1.9μm fully porous particles of narrow particle size distribution.

    Science.gov (United States)

    Catani, Martina; Ismail, Omar H; Cavazzini, Alberto; Ciogli, Alessia; Villani, Claudio; Pasti, Luisa; Bergantin, Caterina; Cabooter, Deirdre; Desmet, Gert; Gasparrini, Francesco; Bell, David S

    2016-07-08

    Columns packed with new commercially available 1.9 fully porous particles of narrow particle size distribution (nPSD) are characterized by extremely high efficiency. Under typical reversed phase conditions, these columns are able to generate very high number of theoretical plates (in the order of 300,000plates/m and more). In this paper, we investigate the origin of the high performance of these nPSD columns by performing a series of measurements that include, in addition to the traditional determination of the van Deemter curve, peak parking, pore blocking and inverse size exclusion experiments. Two nPSD columns (both 100×3.0mm) have been considered in this study: the first one, packed with particles of 80Å pore size, is commercially available. The second one is a prototype column packed with 1.9 fully porous particles of 120Å pore size. The main conclusion of our study is that these nPSD columns are characterized by extremely low eddy dispersion, while longitudinal diffusion and mass transfer kinetics are substantially equivalent to those of other fully porous particles of similar chemistry. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Efficient simultaneous reverse Monte Carlo modeling of pair-distribution functions and extended x-ray-absorption fine structure spectra of crystalline disordered materials.

    Science.gov (United States)

    Németh, Károly; Chapman, Karena W; Balasubramanian, Mahalingam; Shyam, Badri; Chupas, Peter J; Heald, Steve M; Newville, Matt; Klingler, Robert J; Winans, Randall E; Almer, Jonathan D; Sandi, Giselle; Srajer, George

    2012-02-21

    An efficient implementation of simultaneous reverse Monte Carlo (RMC) modeling of pair distribution function (PDF) and EXAFS spectra is reported. This implementation is an extension of the technique established by Krayzman et al. [J. Appl. Cryst. 42, 867 (2009)] in the sense that it enables simultaneous real-space fitting of x-ray PDF with accurate treatment of Q-dependence of the scattering cross-sections and EXAFS with multiple photoelectron scattering included. The extension also allows for atom swaps during EXAFS fits thereby enabling modeling the effects of chemical disorder, such as migrating atoms and vacancies. Significant acceleration of EXAFS computation is achieved via discretization of effective path lengths and subsequent reduction of operation counts. The validity and accuracy of the approach is illustrated on small atomic clusters and on 5500-9000 atom models of bcc-Fe and α-Fe(2)O(3). The accuracy gains of combined simultaneous EXAFS and PDF fits are pointed out against PDF-only and EXAFS-only RMC fits. Our modeling approach may be widely used in PDF and EXAFS based investigations of disordered materials. © 2012 American Institute of Physics

  14. [Rare location of arachnoid cysts. Extratemporal cysts].

    Science.gov (United States)

    Martinez-Perez, Rafael; Hinojosa, José; Pascual, Beatriz; Panaderos, Teresa; Welter, Diego; Muñoz, María J

    2016-01-01

    The therapeutic management of arachnoid cysts depends largely on its location. Almost 50% of arachnoid cysts are located in the temporal fossa-Sylvian fissure, whereas the other half is distributed in different locations, sometimes exceptional. Under the name of infrequent location arachnoid cysts, a description is presented of those composed of 2 sheets of arachnoid membrane, which are not located in the temporal fossa, and are primary or congenital. Copyright © 2015 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  15. Comparing methods for Earthquake Location

    Science.gov (United States)

    Turkaya, Semih; Bodin, Thomas; Sylvander, Matthieu; Parroucau, Pierre; Manchuel, Kevin

    2017-04-01

    There are plenty of methods available for locating small magnitude point source earthquakes. However, it is known that these different approaches produce different results. For each approach, results also depend on a number of parameters which can be separated into two main branches: (1) parameters related to observations (number and distribution of for example) and (2) parameters related to the inversion process (velocity model, weighting parameters, initial location etc.). Currently, the results obtained from most of the location methods do not systematically include quantitative uncertainties. The effect of the selected parameters on location uncertainties is also poorly known. Understanding the importance of these different parameters and their effect on uncertainties is clearly required to better constrained knowledge on fault geometry, seismotectonic processes and at the end to improve seismic hazard assessment. In this work, realized in the frame of the SINAPS@ research program (http://www.institut-seism.fr/projets/sinaps/), we analyse the effect of different parameters on earthquakes location (e.g. type of phase, max. hypocentral separation etc.). We compare several codes available (Hypo71, HypoDD, NonLinLoc etc.) and determine their strengths and weaknesses in different cases by means of synthetic tests. The work, performed for the moment on synthetic data, is planned to be applied, in a second step, on data collected by the Midi-Pyrénées Observatory (OMP).

  16. Lost in Location

    DEFF Research Database (Denmark)

    Hansen, Lone Koefoed

    2009-01-01

    performance, the article examines how the growing locative media industry can learn from the location-aware performative strategies employed by artists who create situated and urban performances for the curious participant. The academic frames employed in the analysis draw on psychogeography, site......-specific performance, social and cultural geography, and aspects of phenomenology....... traversed. While becoming destination aware, the individual loses her location awareness. The article proposes that the reason people get lost when using sat-nav is due to a wrong location-performative paradigm. As an alternative, the article introduces and analyzes two performance-related examples...

  17. Smart Location Database - Download

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Smart Location Database (SLD) summarizes over 80 demographic, built environment, transit service, and destination accessibility attributes for every census block...

  18. Smart Location Database - Service

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Smart Location Database (SLD) summarizes over 80 demographic, built environment, transit service, and destination accessibility attributes for every census block...

  19. Methodology for selection of attributes and operating conditions for SVM-Based fault locator's

    Directory of Open Access Journals (Sweden)

    Debbie Johan Arredondo Arteaga

    2017-01-01

    Full Text Available Context: Energy distribution companies must employ strategies to meet their timely and high quality service, and fault-locating techniques represent and agile alternative for restoring the electric service in the power distribution due to the size of distribution services (generally large and the usual interruptions in the service. However, these techniques are not robust enough and present some limitations in both computational cost and the mathematical description of the models they use. Method: This paper performs an analysis based on a Support Vector Machine for the evaluation of the proper conditions to adjust and validate a fault locator for distribution systems; so that it is possible to determine the minimum number of operating conditions that allow to achieve a good performance with a low computational effort. Results: We tested the proposed methodology in a prototypical distribution circuit, located in a rural area of Colombia. This circuit has a voltage of 34.5 KV and is subdivided in 20 zones. Additionally, the characteristics of the circuit allowed us to obtain a database of 630.000 records of single-phase faults and different operating conditions. As a result, we could determine that the locator showed a performance above 98% with 200 suitable selected operating conditions. Conclusions: It is possible to improve the performance of fault locators based on Support Vector Machine. Specifically, these improvements are achieved by properly selecting optimal operating conditions and attributes, since they directly affect the performance in terms of efficiency and the computational cost.

  20. Distributed generation

    Energy Technology Data Exchange (ETDEWEB)

    Ness, E.

    1999-09-02

    Distributed generation, locating electricity generators close to the point of consumption, provides some unique benefits to power companies and customers that are not available from centralized electricity generation. Photovoltaic (PV) technology is well suited to distributed applications and can, especially in concert with other distributed resources, provide a very close match to the customer demand for electricity, at a significantly lower cost than the alternatives. In addition to augmenting power from central-station generating plants, incorporating PV systems enables electric utilities to optimize the utilization of existing transmission and distribution.

  1. Industrial location and competitiveness

    NARCIS (Netherlands)

    S. Brakman (Steven); J.H. Garretsen (Harry); J.G.M. van Marrewijk (Charles)

    2006-01-01

    textabstractThe interaction between the extent of location advantages and the intensity of firm competition relative to the size of the market jointly determines the location of industrial activity. Technology, factor endowments, geography, and scale economies are influential for determining

  2. Study of DNA uptake locations in single E. coli cells

    Science.gov (United States)

    Xu, C. Shan; Meadow Anderson, L.; Yang, Haw

    2006-03-01

    Artificial gene transfer of bacteria, such as E. coli, has become the main stream technique in genetic engineering and molecular cell biology studies. In spite of the great improvements in transformation efficiency, some fundamental questions remained to be answered. For instance, what are the DNA uptake channels and how do they form and function under external stimuli? Furthermore, where are these channels located on the cell membrane? Here we report a study aimed at DNA uptake locations in the two widely used gene transformation techniques: electroporation and heat shock. A direct visualization of the settling location of single DNA molecules inside individual E. coli cells was obtained by fluorescence imaging and spectroscopy. Electroporation and heat shock exhibit two distinct characteristics of DNA uptake locations. A preferential distribution toward cell poles during electroporation is consistent with earlier experiments and previously proposed models. However, the result from heat shock is unanticipated in which the majority of DNA enters the cell near the center. Such observation suggests that uptake channels form preferentially where newly-synthesized membrane is located under cation and low temperature treatment

  3. Achieve Location Privacy-Preserving Range Query in Vehicular Sensing.

    Science.gov (United States)

    Kong, Qinglei; Lu, Rongxing; Ma, Maode; Bao, Haiyong

    2017-08-08

    Modern vehicles are equipped with a plethora of on-board sensors and large on-board storage, which enables them to gather and store various local-relevant data. However, the wide application of vehicular sensing has its own challenges, among which location-privacy preservation and data query accuracy are two critical problems. In this paper, we propose a novel range query scheme, which helps the data requester to accurately retrieve the sensed data from the distributive on-board storage in vehicular ad hoc networks (VANETs) with location privacy preservation. The proposed scheme exploits structured scalars to denote the locations of data requesters and vehicles, and achieves the privacy-preserving location matching with the homomorphic Paillier cryptosystem technique. Detailed security analysis shows that the proposed range query scheme can successfully preserve the location privacy of the involved data requesters and vehicles, and protect the confidentiality of the sensed data. In addition, performance evaluations are conducted to show the efficiency of the proposed scheme, in terms of computation delay and communication overhead. Specifically, the computation delay and communication overhead are not dependent on the length of the scalar, and they are only proportional to the number of vehicles.

  4. The VSV polymerase can initiate at mRNA start sites located either up or downstream of a transcription termination signal but size of the intervening intergenic region affects efficiency of initiation.

    Science.gov (United States)

    Barr, J N; Tang, Xiaoling; Hinzman, Edward; Shen, Ruizhong; Wertz, Gail W

    2008-05-10

    Transcription by the vesicular stomatitis virus (VSV) polymerase has been characterized as obligatorily sequential with transcription of each downstream gene dependent on termination of the gene immediately upstream. In studies described here we investigated the ability of the VSV RNA-dependent RNA polymerase (RdRp) to access mRNA initiation sites located at increasing distances either downstream or upstream of a transcription termination signal. Bi-cistronic subgenomic replicons were constructed containing progressively extended intergenic regions preceding the initiation site of a downstream gene. The ability of the RdRp to access the downstream sites was progressively reduced as the length of the intergenic region increased. Alternatively, bi-cistronic replicons were constructed containing an mRNA start signal located at increasing distances upstream of a termination site. Analysis of transcription of these "overlapped" genes showed that for an upstream mRNA start site to be recognized it had to contain not only the canonical 3'-UUGUCnnUAG-5' gene start signal, but that signal needed also to be preceded by a U7 tract. Access of these upstream mRNA initiation sites by the VSV RdRp was proportionately reduced with increasing distance between the termination site and the overlapped initiation signal. Possible mechanisms for how the RdRp accesses these upstream start sites are discussed.

  5. High efficiency, narrow particle size distribution, sub-2 μm based macrocyclic glycopeptide chiral stationary phases in HPLC and SFC.

    Science.gov (United States)

    Barhate, Chandan L; Wahab, M Farooq; Breitbach, Zachary S; Bell, David S; Armstrong, Daniel W

    2015-10-22

    State of the art chiral chromatography still employs 3-5 μm bonded or immobilized chiral selectors in 10-25 cm columns. With the availability of 1.9 μm narrow particle size distribution (NPSD) silica, it is now possible to make ever shorter, high efficiency columns practical for sub-minute chiral separations. Three macrocyclic glycopeptides (teicoplanin, teicoplanin aglycone, and vancomycin) were bonded onto 1.9 μm NPSD particles. Such packed columns had ∼80% lower backpressure as compared to polydisperse (PD) 1.7 μm silica materials when using the same mobile phase. The decreased backpressure allowed for diminution of frictional heating and allowed for the use of the 1.9 μm NPSD particle based columns at high flow rates. The 1.9 μm NPSD particle based columns showed up to 190,000 plates m(-1) for chiral molecules and 210,000 plates m(-1) for achiral probes. Representative enantiomeric separations are shown for wide classes of compounds, including different types of amino acids, β-blockers, and pharmaceutically important heterocyclic compounds such as oxazolidinones. Applications in three liquid chromatography modes, namely, reversed phase, polar organic mode and normal phase chiral separations were shown with resolution values ranging from 1.5 to 5.7. Additionally, the same columns were used with supercritical fluid chromatography (SFC) for ultrafast separations. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Measurements of Capture Efficiency of Range Hoods in Homes

    DEFF Research Database (Denmark)

    Simone, Angela; Sherman, Max H.; Walker, Iain S.

    2015-01-01

    mapped the pollution distribution in the room, and showed that the pollutants escape more at the sides of the cooktop. These preliminary results suggest that more measurements should be conducted investigating the capture efficiency at different pollutant source temperature, size and location...

  7. Estimating statistical uncertainty of Monte Carlo efficiency-gain in the context of a correlated sampling Monte Carlo code for brachytherapy treatment planning with non-normal dose distribution.

    Science.gov (United States)

    Mukhopadhyay, Nitai D; Sampson, Andrew J; Deniz, Daniel; Alm Carlsson, Gudrun; Williamson, Jeffrey; Malusek, Alexandr

    2012-01-01

    Correlated sampling Monte Carlo methods can shorten computing times in brachytherapy treatment planning. Monte Carlo efficiency is typically estimated via efficiency gain, defined as the reduction in computing time by correlated sampling relative to conventional Monte Carlo methods when equal statistical uncertainties have been achieved. The determination of the efficiency gain uncertainty arising from random effects, however, is not a straightforward task specially when the error distribution is non-normal. The purpose of this study is to evaluate the applicability of the F distribution and standardized uncertainty propagation methods (widely used in metrology to estimate uncertainty of physical measurements) for predicting confidence intervals about efficiency gain estimates derived from single Monte Carlo runs using fixed-collision correlated sampling in a simplified brachytherapy geometry. A bootstrap based algorithm was used to simulate the probability distribution of the efficiency gain estimates and the shortest 95% confidence interval was estimated from this distribution. It was found that the corresponding relative uncertainty was as large as 37% for this particular problem. The uncertainty propagation framework predicted confidence intervals reasonably well; however its main disadvantage was that uncertainties of input quantities had to be calculated in a separate run via a Monte Carlo method. The F distribution noticeably underestimated the confidence interval. These discrepancies were influenced by several photons with large statistical weights which made extremely large contributions to the scored absorbed dose difference. The mechanism of acquiring high statistical weights in the fixed-collision correlated sampling method was explained and a mitigation strategy was proposed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Global Volcano Locations Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC maintains a database of over 1,500 volcano locations obtained from the Smithsonian Institution Global Volcanism Program, Volcanoes of the World publication. The...

  9. Uranium Location Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — A GIS compiled locational database in Microsoft Access of ~15,000 mines with uranium occurrence or production, primarily in the western United States. The metadata...

  10. SGA Project Locations

    Data.gov (United States)

    Vermont Center for Geographic Information — The stream geomorphic assessment is a physical assessment competed by geomorphologists to determine the condition and sensitivity of a stream. The SGA locations...

  11. Waste Recovery Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Locations where City residents are encouraged to drop off and dispose or recycle of unwanted materials. Information provided is subject to change. Please call ahead...

  12. USAID Activity Locations

    Data.gov (United States)

    US Agency for International Development — The USAID Activities dataset is a snapshot of activities supported by USAID including their geographical locations within countries at the time of the snapshot. The...

  13. Smart Location Mapping

    Science.gov (United States)

    The Smart Location Database, Access to Jobs and Workers via Transit, and National Walkability Index tools can help assess indicators related to the built environment, transit accessibility, and walkability.

  14. Allegheny County Dam Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the point locations of dams in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

  15. VT Hospital Site Locations

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This data layer contains point locations of all major community, regional, comprehensive health, and healthcare provider hospitals in the state of...

  16. District heating biofuel burner efficiency and energy balance

    OpenAIRE

    Okoro, Oluwashola Aderemi

    2015-01-01

    District heating is an optimal system of distributing heat to residential building in a centralized location through pipeline networks. The district heating of woodchip is cost effective, improve energy efficiency, reduce gas emissions and improve energy security. The thermal efficiency and energy balance in a boiler is obtained by combustion analysis of the wood (fuel). In this report, the district heating bio fuel burner in Skien Fjernvarme is considered. The capacity of the boiler is 6MW a...

  17. Improvement of Piezoelectric Energy Harvester Efficiency Through Optimal Patch Configuration

    OpenAIRE

    Gosliga, Julian S.; Ganilova, Olga A.

    2016-01-01

    The aim of this paper is to explore how to improve the efficiency of a vibrating hybrid energy harvester through changing the patch configuration. The results of this work identify the patch configuration that maximises output while using the same amount of piezoelectric material. Using 6 patches was found to be the most efficient when looking at the energy output from a single cycle. Stress distributions generated using ANSYS show that this was because the patches were all locate...

  18. Indoor Positioning with Radio Location Fingerprinting

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun

    . A promising indoor positioning technique is radio-based location ngerprinting, having the major advantage of exploiting already existing radio infrastructures, like IEEE 802.11 or GSM, which avoids extra deployment costs and eort. The research goal of this thesis is to address the limitations of current...... are heterogeneous even when only considering clients for the same technology. The heterogeneity is due to dierent radios, antennas, and rmwares causing measurements for location ngerprinting not to be directly comparable among clients. Heterogeneity is a challenge for location ngerprinting because it severely...... decreases the precision of location ngerprinting. To support many clients location ngerprinting has to address how to scale estimate calculation, measurement distribution, and distribution of position estimates. This is a challenge because of the number of calculations involved and the frequency...

  19. Location and logistics

    OpenAIRE

    Alumura, Sibel A.; Karab, Bahar Y.; Melo, M. Teresa

    2013-01-01

    Facility location decisions play a critical role in designing logistics networks. This article provides some guidelines on how location decisions and logistics functions can be integrated into a single mathematical model to optimize the configuration of a logistics network. This will be illustrated by two generic models, one supporting the design of a forward logistics network and the other addressing the specific requirements of a reverse logistics network. Several special cases and extensio...

  20. Transformer Efficiency Assessment - Okinawa, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L. Baldwin; Robert J. Turk; Kurt S. Myers; Jake P. Gentle; Jason W. Bush

    2012-05-01

    The US Army Engineering & Support Center, Huntsville (USAESCH), and the US Marine Corps Base (MCB), Okinawa, Japan retained Idaho National Laboratory (INL) to conduct a Transformer Efficiency Assessment of “key” transformers located at multiple military bases in Okinawa, Japan. The purpose of this assessment is to support the Marine Corps Base, Okinawa in evaluating medium voltage distribution transformers for potential efficiency upgrades. The original scope of work included the MCB providing actual transformer nameplate data, manufacturer’s factory test sheets, electrical system data (kWh), demand data (kWd), power factor data, and electricity cost data. Unfortunately, the MCB’s actual data is not available and therefore making it necessary to de-scope the original assessment. Note: Any similar nameplate data, photos of similar transformer nameplates, and basic electrical details from one-line drawings (provided by MCB) are not a replacement for actual load loss test data. It is recommended that load measurements are performed on the high and low sides of transformers to better quantify actual load losses, demand data, and power factor data. We also recommend that actual data, when available, be inserted by MCB Okinawa where assumptions have been made and then the LCC analysis updated. This report covers a generalized assessment of modern U.S. transformers in a three level efficiency category, Low-Level efficiency, Medium-Level efficiency, and High-Level efficiency.

  1. Transformer Efficiency Assessment - Okinawa, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L. Baldwin; Robert J. Turk; Kurt S. Myers; Jake P. Gentle; Jason W. Bush

    2012-08-01

    The US Army Engineering & Support Center, Huntsville (USAESCH), and the US Marine Corps Base (MCB), Okinawa, Japan retained Idaho National Laboratory (INL) to conduct a Transformer Efficiency Assessment of “key” transformers located at multiple military bases in Okinawa, Japan. The purpose of this assessment is to support the Marine Corps Base, Okinawa in evaluating medium voltage distribution transformers for potential efficiency upgrades. The original scope of work included the MCB providing actual transformer nameplate data, manufacturer’s factory test sheets, electrical system data (kWh), demand data (kWd), power factor data, and electricity cost data. Unfortunately, the MCB’s actual data is not available and therefore making it necessary to de-scope the original assessment. Note: Any similar nameplate data, photos of similar transformer nameplates, and basic electrical details from one-line drawings (provided by MCB) are not a replacement for actual load loss test data. It is recommended that load measurements are performed on the high and low sides of transformers to better quantify actual load losses, demand data, and power factor data. We also recommend that actual data, when available, be inserted by MCB Okinawa where assumptions have been made and then the LCC analysis updated. This report covers a generalized assessment of modern U.S. transformers in a three level efficiency category, Low-Level efficiency, Medium-Level efficiency, and High-Level efficiency.

  2. A Hybrid Algorithm for Fault Locating in Looped Microgrids

    DEFF Research Database (Denmark)

    Beheshtaein, Siavash; Savaghebi, Mehdi; Quintero, Juan Carlos Vasquez

    2016-01-01

    ride through (LVRT). Besides these challenges, it is desired to eliminate the relays for distribution lines and locate faults based on distributed generations (DGs) voltage or current. On the other hands increasing in the number of DGs and lines would result in high computation burden and degradation......Protection is the last obstacle to realizing the idea of microgrid. Some of the main challenges in microgrid protection include topology changes of microgrid, week-infeed fault, bidirectional power flow effects, blinding of the protection, sympathetic tripping, high impedance fault, and low voltage...... the efficiency and accuracy of the methods that utilize all these information. This paper deals with this issue by analyzing only DGs’ voltage. In the first step, a fault is detected by the voltage of each DG, then the DG with the highest voltage collapse injects 333 Hz harmonic to find another DG that the fault...

  3. Planning Pharmacies: An Operational Method to Find the Best Location

    Directory of Open Access Journals (Sweden)

    Simona Tondelli

    2014-05-01

    Full Text Available The theme of the spatial distribution of the pharmacies on the territory is closely connected to urban planning and to services supply. In Italy, the regulatory change that took place in 2012, triggered partly by the need to adhere more to a constantly changing economic system, has led to a revision of the existing situation, consisting both on the method to quantify the pharmacies distribution and on the efficiency of the service. If Law 27/2012 has effectively allowed municipalities to increase the number of pharmacies that they can settle on the municipal territory, it has also started a process of rethinking the logic of pharmacies location and of their catchment areas. In this framework, the present paper aims to discuss the merits of a regulatory evolutions that sparked the process of liberalization of locations, integrating the law guidelines and goals with an operating logic process, usable and useful to translate goals into planning actions in a continuous dialogue between law and territory, constraints and opportunities, equity and accessibility of the care services. Following this logic operations, we have investigated the urban context of Castelfranco Emilia, assuming the location of new offices on the basis of pharmaceutical analyzes.

  4. Facility location and staffing analysis for TransAlta Utilities

    Energy Technology Data Exchange (ETDEWEB)

    Erkut, E.; Myroon, T. [Alberta Univ., Edmonton, AB (Canada); Strangway, K. [TransAlta Utilities, St. Albert, AB (Canada)

    1998-10-01

    TransAlta Utilities is planning major changes in the way it does business. The utility has been a major supplier of electricity to Albertans since 1911. It currently has a decentralized dispatching system with a large number of customer service representatives (CSR) over their service area which is divided into three regions and 19 areas. There are at present a total of 57 customer service facilities which are open to the public. The utility concluded that the current service organization was no longer adequate and efficient to carry on its business and decided to consolidate its CSRs in a centralized call centre to be located in Calgary. It is believed that a central call centre will improve efficiency through centralized dispatching and remove the arbitrary borders between service areas of the facilities. The optimal number of facilities needed in a distribution system was determined by the tradeoff between facility costs and transport costs. The p-median model was used to select facility locations so as to minimize the sum of the travel distances between facilities and demand points. It was suggested that anywhere between 55 and 60 facilities could be run efficiently. However, unlike present facilities which are open to the public, future facilities will be simply home-bases for the linemen, where communication equipment, terrain maps, repair equipment and trucks will be kept. Details of the study leading to these recommendations are discussed. 2 refs.

  5. A Simple and Automatic Method for Locating Surgical Guide Hole

    Science.gov (United States)

    Li, Xun; Chen, Ming; Tang, Kai

    2017-12-01

    Restoration-driven surgical guides are widely used in implant surgery. This study aims to provide a simple and valid method of automatically locating surgical guide hole, which can reduce operator's experiences and improve the design efficiency and quality of surgical guide. Few literatures can be found on this topic and the paper proposed a novel and simple method to solve this problem. In this paper, a local coordinate system for each objective tooth is geometrically constructed in CAD system. This coordinate system well represents dental anatomical features and the center axis of the objective tooth (coincide with the corresponding guide hole axis) can be quickly evaluated in this coordinate system, finishing the location of the guide hole. The proposed method has been verified by comparing two types of benchmarks: manual operation by one skilled doctor with over 15-year experiences (used in most hospitals) and automatic way using one popular commercial package Simplant (used in few hospitals).Both the benchmarks and the proposed method are analyzed in their stress distribution when chewing and biting. The stress distribution is visually shown and plotted as a graph. The results show that the proposed method has much better stress distribution than the manual operation and slightly better than Simplant, which will significantly reduce the risk of cervical margin collapse and extend the wear life of the restoration.

  6. Electron-Microscopic Examination of the Distribution of Sodium in Corti’s Organ of Animals, That Are Located in the State of Relative Rest and in the Conditions of Sonic Action

    Science.gov (United States)

    1992-03-18

    plasmatic membrane , which covers the lateral surfaces of receptor cells, is extremely poor in the granules of pyroantimonate of sodium. In the...granules. In the nervous interlacements the reaction products distinctly are outlined along the plasmatic membrane of DOC = 91123500 PAGE 7 nervous...elongation/extent of plasmatic membrane . In the cytoplasm and in the cristae of mitochondria separate small granules are encountered. The latter are located

  7. Geostar - Navigation location system

    Science.gov (United States)

    Keyser, Donald A.

    The author describes the Radiodetermination Satellite Service (RDSS). The initial phase of the RDSS provides for a unique service enabling central offices and headquarters to obtain position-location information and receive short digital messages from mobile user terminals throughout the contiguous United States, southern Canada, and northern Mexico. The system employs a spread-spectrum, CDMA modulation technique allowing multiple customers to use the system simultaneously, without preassigned coordination with fellow users. Position location is currently determined by employing an existing radio determination receiver, such as Loran-C, GPS, or Transit, in the mobile user terminal. In the early 1990s position location will be determined at a central earth station by time-differential ranging of the user terminals via two or more geostationary satellites. A brief overview of the RDSS system architecture is presented with emphasis on the user terminal and its diverse applications.

  8. A hybrid algorithm for stochastic single-source capacitated facility location problem with service level requirements

    Directory of Open Access Journals (Sweden)

    Hosseinali Salemi

    2016-04-01

    Full Text Available Facility location models are observed in many diverse areas such as communication networks, transportation, and distribution systems planning. They play significant role in supply chain and operations management and are one of the main well-known topics in strategic agenda of contemporary manufacturing and service companies accompanied by long-lasting effects. We define a new approach for solving stochastic single source capacitated facility location problem (SSSCFLP. Customers with stochastic demand are assigned to set of capacitated facilities that are selected to serve them. It is demonstrated that problem can be transformed to deterministic Single Source Capacitated Facility Location Problem (SSCFLP for Poisson demand distribution. A hybrid algorithm which combines Lagrangian heuristic with adjusted mixture of Ant colony and Genetic optimization is proposed to find lower and upper bounds for this problem. Computational results of various instances with distinct properties indicate that proposed solving approach is efficient.

  9. Locating Hidden Servers

    National Research Council Canada - National Science Library

    Oeverlier, Lasse; Syverson, Paul F

    2006-01-01

    .... Announced properties include server resistance to distributed DoS. Both the EFF and Reporters Without Borders have issued guides that describe using hidden services via Tor to protect the safety of dissidents as well as to resist censorship...

  10. Robust facility location

    OpenAIRE

    Carrizosa Priego, Emilio José; Nickel, Stefan

    2003-01-01

    Let A be a nonempty finite subset of the plane representing the geographical coordinates of a set of demand points (towns, …), to be served by a facility, whose location within a given region S is sought. Assuming that the unit cost for a∈A if the facility is located at x∈S is proportional to dist(x,a) — the distance from x to a — and that demand of point a is given by ωa, minimizing the total transportation cost TC(ω,x) amounts to solving the Weber problem. In practice, it may be the case, h...

  11. Location-based games

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine

    to create meaningful experiences; and of the prerequisites of a meaningful meeting between players and locations. The dissertation contributes to the field of LBG research by offering an enhanced understanding of LBGs, and LBG player experiences, as well as providing an expanded vocabulary describing LBG...... elements. In addition, the dissertation provides design knowledge concerning creating LBGs that uses certain emergent opportunities when combining location-aware technologies with game mechanics to make use of the six dimensions of LBGs and to involve the player’s body – i.e. make a meaningful meeting...

  12. Eficiencia de la estrategia de gestión y localización de los residuos de la Comunidad de Madrid / Efficiency of management strategy and location of Madrid Autonomous Region waste

    Directory of Open Access Journals (Sweden)

    Clara Martínez Miguel

    2012-09-01

    started by an inefficient infrastructure network of domestic waste. The heterogeneity between different areas and dumps management is the key to this investigation.KeywordsDumps, domestic waste, management and location, dump loading, waste moving, General Urban Development Plan.

  13. 40 CFR 141.605 - Subpart V compliance monitoring location recommendations.

    Science.gov (United States)

    2010-07-01

    ... residence time compliance monitoring location (maximum residence time compliance monitoring location for... location. (7) Existing subpart L average residence time compliance monitoring location (maximum residence... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Initial Distribution...

  14. Crime Location Choice

    NARCIS (Netherlands)

    Bernasco, Wim; Ruiter, Stijn

    2014-01-01

    Most behavior of interest to social scientists is choice behavior: actions people commit while they could also have done something else. In geographical and environmental criminology, a new framework has emerged for analyzing individual crime location choice. It is based on the principle of random

  15. The Czech Locative Chameleon

    Directory of Open Access Journals (Sweden)

    Tarald Taraldsen

    2007-12-01

    Full Text Available We show that under certain circumstances, the Czech locative prepositions (LOC show up as directional prepositions (DIR and vice versa, (under different circumstances the Czech DIR PPs show up as LOC. We argue that such a chameleon life of the PPs is structurally dependent.

  16. Tracking, say, SKYPE Locations

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Tracking, say, SKYPE Locations. Real Time Communication: Peer-to-Peer (P2P). Datagram flows between the two conversing partners; Exposes the IP addresses of all the participants to one another. If A knows B's VoIP ID, she can establish a call with Bob & obtain his current ...

  17. General minisum circle location

    DEFF Research Database (Denmark)

    Körner, Mark; Brimberg, Jack; Juel, Henrik

    2009-01-01

    In our paper we approximate a set of given points by a general circle. More precisely, we consider the problem of locating and scaling the unit ball of some given norm k1 with respect to xed points on the plane such that the sum of weighted distances between the circle and the xed points...

  18. ATL: ASA Tutor Locator

    NARCIS (Netherlands)

    Brouwers, Maurice; Brouns, Francis; Van Rosmalen, Peter; Sloep, Peter; Koper, Rob

    2006-01-01

    ASA Tutor Locator creates ad hoc transient communities consisting of peer tutors, seeded with document fragments found in the learning network, to answer content questions of students. The sources are available from http://sourceforge.net/projects/asa-atl. Available under the three clause BSD

  19. ATL: A Tutor Locator

    NARCIS (Netherlands)

    De Jong, André; Brouwers, Maurice; Brouns, Francis; Van Rosmalen, Peter; Kester, Liesbeth; Sloep, Peter

    2007-01-01

    A Tutor Locator creates ad hoc transient communities consisting of peer tutors, seeded with document fragments found in the learning network, to answer content questions of students. The sources are available from http://sourceforge.net/projects/asa-atl.Available under the three clause BSD licence,

  20. Immigrants' location preferences

    DEFF Research Database (Denmark)

    Damm, Anna Piil

    This paper exploits a spatial dispersal policy for refugee immigrants to estimate the importance of local and regional factors for refugees' location preferences. The main results of a mixed proportional hazard competing risks model are that placed refugees react to high regional unemployment...