WorldWideScience

Sample records for model mobile load

  1. CDMA coverage under mobile heterogeneous network load

    NARCIS (Netherlands)

    Saban, D.; van den Berg, Hans Leo; Boucherie, Richardus J.; Endrayanto, A.I.

    2002-01-01

    We analytically investigate coverage (determined by the uplink) under non-homogeneous and moving traffic load of third generation UMTS mobile networks. In particular, for different call assignment policies, we investigate cell breathing and the movement of the coverage gap occurring between cells

  2. CDMA coverage under mobile heterogeneous network load

    NARCIS (Netherlands)

    Saban, Dorin; Berg, van den Hans; Boucherie, Richard J.; Endrayanto, Irwan

    2002-01-01

    We analytically investigate coverage (determined by the uplink) under non-homogeneous and moving traffic load of third generation UMTS mobile networks. In particular, for different call assignment policies, we investigate cell breathing and the movement of the coverage gap occurring between cells wh

  3. Maximum Allowable Dynamic Load of Mobile Manipulators with Stability Consideration

    Directory of Open Access Journals (Sweden)

    Heidary H. R.

    2015-09-01

    Full Text Available High payload to mass ratio is one of the advantages of mobile robot manipulators. In this paper, a general formula for finding the maximum allowable dynamic load (MADL of wheeled mobile robot is presented. Mobile manipulators operating in field environments will be required to manipulate large loads, and to perform such tasks on uneven terrain, which may cause the system to reach dangerous tip-over instability. Therefore, the method is expanded for finding the MADL of mobile manipulators with stability consideration. Moment-Height Stability (MHS criterion is used as an index for the system stability. Full dynamic model of wheeled mobile base and mounted manipulator is considered with respect to the dynamic of non-holonomic constraint. Then, a method for determination of the maximum allowable loads is described, subject to actuator constraints and by imposing the stability limitation as a new constraint. The actuator torque constraint is applied by using a speed-torque characteristics curve of a typical DC motor. In order to verify the effectiveness of the presented algorithm, several simulation studies considering a two-link planar manipulator, mounted on a mobile base are presented and the results are discussed.

  4. Residential mobility microsimulation models

    Science.gov (United States)

    Wang, Yifei; Wu, Lun

    2010-09-01

    Residential mobility refers to the spatial movement of individuals and households between dwellings within an urban area. This considerable amount of intra-urban movement affects the urban structure and has significant repercussions for urban transportation. In order to understand and project related impacts, a considerable number of residential mobility models has been developed and used in the regional planning process. Within this context, the history and state-of-art residential mobility models are discussed and indicated. Meanwhile, a residential mobility Microsimulation model, called URM-Microsim (Urban Residential Mobility Microsimulation), is introduced and discussed.

  5. Electrical load modeling

    Energy Technology Data Exchange (ETDEWEB)

    Valgas, Helio Moreira; Pinto, Roberto del Giudice R.; Franca, Carlos [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil); Lambert-Torres, Germano; Silva, Alexandre P. Alves da; Pires, Robson Celso; Costa Junior, Roberto Affonso [Escola Federal de Engenharia de Itajuba, MG (Brazil)

    1994-12-31

    Accurate dynamic load models allow more precise calculations of power system controls and stability limits, which are critical mainly in the operation planning of power systems. This paper describes the development of a computer program (software) for static and dynamic load model studies using the measurement approach for the CEMIG system. Two dynamic load model structures are developed and tested. A procedure for applying a set of measured data from an on-line transient recording system to develop load models is described. (author) 6 refs., 17 figs.

  6. Complex Mobile Learning That Adapts to Learners' Cognitive Load

    Science.gov (United States)

    Deegan, Robin

    2015-01-01

    Mobile learning is cognitively demanding and frequently the ubiquitous nature of mobile computing means that mobile devices are used in cognitively demanding environments. This paper examines the use of mobile devices from a Learning, Usability and Cognitive Load Theory perspective. It suggests scenarios where these fields interact and presents an…

  7. Complex Mobile Learning That Adapts to Learners' Cognitive Load

    Science.gov (United States)

    Deegan, Robin

    2015-01-01

    Mobile learning is cognitively demanding and frequently the ubiquitous nature of mobile computing means that mobile devices are used in cognitively demanding environments. This paper examines the use of mobile devices from a Learning, Usability and Cognitive Load Theory perspective. It suggests scenarios where these fields interact and presents an…

  8. Comparison of contact stresses of the test tyres used by the one third scale model mobile load simulator (MMLS3) and the full-scale test tyres of the Heavy Vehicle Simulator (HVS) - a summary

    CSIR Research Space (South Africa)

    De Beer, Morris

    2007-07-01

    Full Text Available This paper summarises the results of a study in which the maximum vertical contact stressess of the one third scale test tyres of the Model Mobile Load Simulator (MMLS3) were compared with those measured for three types of full-scale test tyres...

  9. Charging of mobile services by mobile payment reference model

    OpenAIRE

    Pousttchi, Key; Wiedemann, Dietmar Georg

    2005-01-01

    The purpose of the paper is to analyze mobile payments in the mobile commerce scenario. Therefore, we first classify the mobile payment in the mobile commerce scenario by explaining general offer models, charging concepts, and intermediaries. Second, we describe the mobile payment reference model, especially, the mobile payment reference organization model and different mobile payment standard types. Finally, we conclude our findings.

  10. Efficient Load Balancing Routing Technique for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Mahdi Abdulkader Salem

    2016-05-01

    Full Text Available The mobile ad hoc network (MANET is nothing but the wireless connection of mobile nodes which provides the communication and mobility among wireless nodes without the need of any physical infrastructure or centralized devices such as access point or base station. The communication in MANET is done by routing protocols. There are different categories of routing protocols introduced with different goals and objectives for MANETs such as proactive routing protocols (e.g. DSDV, reactive routing protocols (e.g. ADOV, geographic routing protocols (e.g. GRP, hybrid routing protocols etc. There are two important research problems with such routing protocols to address such as efficient load balancing and energy efficiency. In this paper, we are focusing on evaluation and analysis of efficient load balancing protocol design for MANET. Inefficient load balancing technique results in increasing routing overhead, poor packet delivery ratio, and other Quality of Service (QoS parameters. In literature, there are a number of different methods proposed for improving the performance of routing protocols by efficient load balancing among mobile nodes communication. However, most of the methods suffer from various limitations. In this paper, we propose a novel technique for improved the QoS performance of load balancing approach as well as increasing the network lifetime. Evaluation of Network lifetime is out of scope of this paper.

  11. Load Balancing on Open Networks: A Mobile Agent Approach

    Directory of Open Access Journals (Sweden)

    R. B. Patel

    2006-01-01

    Full Text Available In order to disperse the load on a Web server, generally the server cluster is configured to distribute access requests, or mirror servers are distributed geographically on different networks. Use of the Internet and the World-Wide-Web (WWW has become widespread in recent years and mobile agent technology has proliferated at an equally rapid rate to evenly distribute the requests to web servers through load balancing. There are various loads balancing policies came into picture. Primitive one is Message Passing Interface (MPI. Its wide availability and portability make it an attractive choice, however the communication requirements are sometimes inconventior and inefficient when implementing the primitives provided by MPI. Mobile agent (MA based approach have the merits of high flexibility, efficiency, low network traffic, less communication latency as well as highly asynchronous. In this study we present dynamic load balancing using mobile agent technology in which when a node is overloaded, task migrates to less utilized nodes so as to share the workload. However, the decision of which nodes receive migrating task is made in real-time by design and implementation of a framework called Platform for Load balancing (PLB. It is implemented on PMADE (A Platform for Mobile Agent Distribution and Execution. PLB integrated web servers can dispatch MAs to retrieve load information and accomplish load redistribution on all servers. The performance evaluation demonstrates that the PLB framework provides a foundation to develop efficient load balancing schemes on wide range of web server systems from cluster to open network and the results of a comparison of PLB, with some existing ones, is also reported.

  12. Changing Trends in Modeling Mobility

    Directory of Open Access Journals (Sweden)

    Aarti Munjal

    2012-01-01

    Full Text Available A phenomenal increase in the number of wireless devices has led to the evolution of several interesting and challenging research problems in opportunistic networks. For example, the random waypoint mobility model, an early, popular effort to model mobility, involves generating random movement patterns. Previous research efforts, however, validate that movement patterns are not random; instead, human mobility is predictable to some extent. Since the performance of a routing protocol in an opportunistic network is greatly improved if the movement patterns of mobile users can be somewhat predicted in advance, several research attempts have been made to understand human mobility. The solutions developed use our understanding of movement patterns to predict the future contact probability for mobile nodes. In this work, we summarize the changing trends in modeling human mobility as random movements to the current research efforts that model human walks in a more predictable manner. Mobility patterns significantly affect the performance of a routing protocol. Thus, the changing trend in modeling mobility has led to several changes in developing routing protocols for opportunistic networks. For example, the simplest opportunistic routing protocol forwards a received packet to a randomly selected neighbor. With predictable mobility, however, routing protocols can use the expected contact information between a pair of mobile nodes in making forwarding decisions. In this work, we also describe the previous and current research efforts in developing routing protocols for opportunistic networks.

  13. Application Scheduling in Mobile Cloud Computing with Load Balancing

    Directory of Open Access Journals (Sweden)

    Xianglin Wei

    2013-01-01

    Full Text Available Mobile cloud computing (MCC enables the mobile devices to offload their applications to the cloud and thus greatly enriches the types of applications on mobile devices and enhances the quality of service of the applications. Under various circumstances, researchers have put forward several MCC architectures. However, how to reduce the response latency while efficiently utilizing the idle service capacities of the mobile devices still remains a challenge. In this paper, we firstly give a definition of MCC and divide the recently proposed architectures into four categories. Secondly, we present a Hybrid Local Mobile Cloud Model (HLMCM by extending the Cloudlet architecture. Then, after formulating the application scheduling problems in HLMCM and bringing forward the Hybrid Ant Colony algorithm based Application Scheduling (HACAS algorithm, we finally validate the efficiency of the HACAS algorithm by simulation experiments.

  14. Intelligent Mobility Modeling and Simulation

    Science.gov (United States)

    2015-03-04

    cog.cs.drexel.edu/act-r/index.html) •Models sensory / motor performance of human driver or teleoperator 27UNCLASSIFIED: Distribution Statement A. Approved for...U.S. ARMY TANK AUTOMOTIVE RESEARCH, DEVELOPMENT AND ENGINEERING CENTER Intelligent Mobility Modeling and Simulation 1 Dr. P. Jayakumar, S. Arepally...Prescribed by ANSI Std Z39-18 Contents 1. Mobility - Autonomy - Latency Relationship 2. Machine - Human Partnership 3. Development of Shared Control

  15. Mobile Learning Application Interfaces: First Steps to a Cognitive Load Aware System

    Science.gov (United States)

    Deegan, Robin

    2013-01-01

    Mobile learning is a cognitively demanding application and more frequently the ubiquitous nature of mobile computing means that mobile devices are used in cognitively demanding environments. This paper examines the nature of this use of mobile devices from a Learning, Usability and Cognitive Load Theory perspective. It suggests scenarios where…

  16. Performance Evaluation of Mobility Anchor Point with Guard Load Reservation in Hierarchical Mobile IPv6

    Institute of Scientific and Technical Information of China (English)

    Yung-Chung Wang; Li-Hsin Chiang; Hung-Pin Lin

    2014-01-01

    Hierarchical mobile IPv6 (HMIPv6) introduces a mobility anchor point to reduce the signaling overhead and handoff latency. In this paper, we apply the matrix-analytical approach to explore the performance measures of the ongoing mobile nodes (MNs) drop and new MNs block probabilities of mobility anchor point with a guard bandwidth reservation scheme. We apply the Markovian arrival process (MAP) to model ongoing MNs and new MNs. Five related performance measures are derived, including the long-term new MN block and ongoing MN drop probabilities, and the three short-term measures of average length of a block period and a non-block period, as well as the conditional ongoing MN drop probability during a block period. These performance measures greatly assist the guard bandwidth reservation mechanism in determining a proper threshold guard bandwidth. The results presented in this paper can provide guidelines for designing adaptive algorithms to adjust the threshold in the guard bandwidth reservation scheme.

  17. Modelling Mobility: A Discrete Revolution

    CERN Document Server

    Clementi, Andrea; Silvestri, Riccardo

    2010-01-01

    We introduce a new approach to model and analyze \\emph{Mobility}. It is fully based on discrete mathematics and yields a class of mobility models, called the \\emph{Markov Trace} Model. This model can be seen as the discrete version of the \\emph{Random Trip} Model including all variants of the \\emph{Random Way-Point} Model \\cite{L06}. We derive fundamental properties and \\emph{explicit} analytical formulas for the \\emph{stationary distributions} yielded by the Markov Trace Model. Such results can be exploited to compute formulas and properties for concrete cases of the Markov Trace Model by just applying counting arguments. We apply the above general results to the discrete version of the \\emph{Manhattan Random Way-Point} over a square of bounded size. We get formulas for the total stationary distribution and for two important \\emph{conditional} ones: the agent spatial and destination distributions. Our method makes the analysis of complex mobile systems a feasible task. As a further evidence of this important...

  18. The Models and Politics of Mobile Media

    Directory of Open Access Journals (Sweden)

    Gerard Goggin

    2008-01-01

    Full Text Available In this paper I seek to critically evaluate the models at play in an important area of new media cultures -- mobile media. By 'mobile', I mean the new technologies, cultural practices, and arrangements of production, consumption, and exchange, emerging with hand-held, networked devices --especially those based on mobile cellular networks. These mobile phone technologies are now commonly being framed as media; and so we see the appearance of objects such as mobile television, mobile film, mobile games, and mobile Internet. This much-heralded move, with its large cultural and commercial claims, raises important theoretical and political questions. To zero in on what it at stake in the shift from mobile phone to mobile media, I consider three distinct though related models that for ease of reference I will term: phones; commons; publics. Firstly, I look at the model of the telephone (latterly, telecommunications that is still strongly influential in the shaping of mobiles as they now figure as media. This is something that is not widely recognised, however -- for instance, when mobiles as simply seen as an extension of new media cultures based on ideas formed through the experience of the Internet. Secondly, I consider the model of the commons and what light it throws on the politics of mobile media. Discussions of the commons -- for instance, the lucid work of Yochai Benkler in his 2006 The Wealth of Networks -- typically take the Internet as their paradigm example. But what how does the model of commons relate to mobiles, and what might it tell us about mobile media? Thirdly, while the telephone and mobile phone also have often been modelled through the concept of 'community', mobile media encourage us to think about the different and sometimes opposed model of publics. In drawing upon recent work on publics, what I am interested here is how new kinds of publics are emerging with mobile media.

  19. The Economic Mobility in Money Transfer Models

    CERN Document Server

    Ding, N; Wang, Y; Ding, Ning; Xi, Ning; Wang, Yougui

    2005-01-01

    In this paper, we investigate the economic mobility in some money transfer models which have been applied into the research on monetary distribution. We demonstrate the mobility by recording the agents' ranks time series and observing the volatility. We also compare the mobility quantitatively by employing an index, "the per capita aggregate change in log-income", raised by economists. Like the shape of distribution, the character of mobility is also decided by the trading rule in these transfer models. It is worth noting that even though different models have the same type of distribution, their mobility characters may be quite different.

  20. The economic mobility in money transfer models

    Science.gov (United States)

    Ding, Ning; Xi, Ning; Wang, Yougui

    2006-07-01

    In this paper, we investigate the economic mobility in four money transfer models which have been applied into the research on wealth distribution. We demonstrate the mobility by recording the time series of agents’ ranks and observing their volatility. We also compare the mobility quantitatively by employing an index, “the per capita aggregate change in log-income”, proposed by economists. Like the shape of distribution, the character of mobility is also decided by the trading rule in these transfer models. It is worth noting that even though two models have the same type of distribution, their mobility characters may be quite different.

  1. Classification and Evaluation of Mobility Metrics for Mobility Model Movement Patterns in Mobile Ad-Hoc Networks

    Directory of Open Access Journals (Sweden)

    Santosh Kumar S

    2011-10-01

    Full Text Available A mobile ad hoc network is collection of self configuring and adaption of wireless link between communicating devices (mobile devices to form an arbitrary topology and multihop wireless connectivity without the use of existing infrastructure. It requires efficient dynamic routing protocol to determine the routes subsequent to a set of rules that enables two or more devices to communicate with each others. This paper basically classifies and evaluates the mobility metrics into two categories- direct mobility metrics and derived mobility metrics. These two mobility metrics has been used to measure different mobility models, this paper considers some of mobility models i.e Random Waypoint Model, Reference Point Group Mobility Model, Random Direction Mobility Model, Random Walk Mobility Model, Probabilistic Random Walk, Gauss Markov, Column Mobility Model, Nomadic Community Mobility Model and Manhattan Grid Model.

  2. Evaluation Of Scheduling And Load Balancing Techniques In Mobile Grid Architecture

    Directory of Open Access Journals (Sweden)

    Debabrata Singh

    2011-09-01

    Full Text Available Recent advances in mobile communications and computing are strong interest of the scientific community in the Grid have led to research into the Mobile Grid. Based on a realistic Mobile Grid architecture we formulate the problem of job scheduling and load balancing techniques in a mobile environment and performance metrics. We extended the work by introducing a new scheduling policy and load balancing policy based on the notion of installments and intra cluster load balancing algorithm and continue the evaluation of the expanded set of scheduling and load balancing strategies in an effort to overcome the intermittent character of connectivity in a mobile environment. On real wireless traces, we demonstrated the superiority of the proposed policy, and showed the feasibility of a Mobile Grid system and design the efficient scheduling and load balancing policies subject to the underlying mobility were based a small part of the offered resources is wasted and a small part of the workload has to be processed again .The size of the installments increases as the size of the aborted fragments of the workload increases.

  3. Modeling and control of thermostatically controlled loads

    OpenAIRE

    2011-01-01

    As the penetration of intermittent energy sources grows substantially, loads will be required to play an increasingly important role in compensating the fast time-scale fluctuations in generated power. Recent numerical modeling of thermostatically controlled loads (TCLs) has demonstrated that such load following is feasible, but analytical models that satisfactorily quantify the aggregate power consumption of a group of TCLs are desired to enable controller design. We develop such a model for...

  4. Mobile Education-proposing a Mobile Learning Model for Designing an Institutional Mobile Scenario

    Directory of Open Access Journals (Sweden)

    Ouiame Filali Marzouki

    2014-05-01

    Full Text Available Inspired by the theory of activity, the context model and previous researches, this paper proposes a model bringing together the key concepts of a mobile learning environment based on the concept of contextualization, major advantage of mobile learning. It details the learning mobile environment, its main components, its characteristics and the different interactions between them. The proposed model meets the constraint of mobile learning complementarity, allowing flexibility in its integration with classroom learning such as e-learning or blended learning. It mainly improves upon conventional learning methods and advocates others such as situated, interactive and connectivist learning. Indeed, research several that mobile learning enhances the educational program and reinstates it into the daily lives of learners through their own mobile technologies. Properly implemented, Mobile Learning can make learning activities as fun, as beneficial and certainly more motivating for learners and educators especially in the mobile era where traditional learning methods don’t meet all learners’ needs. Mobiles, connected and in constant social interaction, learners require learning systems more adapted to their communicative and interactive nature. This paper is an early implementation of this concept in learning systems. It aims to help educators to integrate mobile technologies into their learning activities without alternating their educational goals.

  5. Future mobile internet services : business model scenarios

    OpenAIRE

    2004-01-01

    In this report we explore future business models for mobile internet services. Based on four different scenarios, we sketch out how future conditions in the mobile industry may influence value propositions, value networks, and financial aspects of mobile services. The four scenarios vary along two dimensions - technological development and social identity, and different combinations of these two dimensions provide us with four scenarios where quite different business models can be expected. M...

  6. Modeling of Generic Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; Bendtsen, Jan Dimon; la Cour-Harbo, Anders

    2009-01-01

    This paper presents the result of the modelling and verification of a generic slung load system using a small-scale helicopter. The model is intended for use in simulation, pilot training, estimation, and control. The model is derived using a redundant coordinate formulation based on Gauss......' Principle of Least Constraint using the Udwadia-Kalaba equation and can be used to model all body to body slung load suspension types. The model provides intuitive and easy-to-use means of modelling and simulating different slung load suspension types. It includes detection of, and response to, wire...... slackening and tightening as well as aerodynamic coupling between the helicopter and the load. Furthermore, it is shown how the model can be easily used for multi-lift systems either with multiple helicopters or multiple loads. A numerical stabilisation algorithm is introduced and finally the use...

  7. Modelling the scaling properties of human mobility

    Science.gov (United States)

    Song, Chaoming; Koren, Tal; Wang, Pu; Barabási, Albert-László

    2010-10-01

    Individual human trajectories are characterized by fat-tailed distributions of jump sizes and waiting times, suggesting the relevance of continuous-time random-walk (CTRW) models for human mobility. However, human traces are barely random. Given the importance of human mobility, from epidemic modelling to traffic prediction and urban planning, we need quantitative models that can account for the statistical characteristics of individual human trajectories. Here we use empirical data on human mobility, captured by mobile-phone traces, to show that the predictions of the CTRW models are in systematic conflict with the empirical results. We introduce two principles that govern human trajectories, allowing us to build a statistically self-consistent microscopic model for individual human mobility. The model accounts for the empirically observed scaling laws, but also allows us to analytically predict most of the pertinent scaling exponents.

  8. Modelling of Generic Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; Bendtsen, Jan Dimon; La Cour-Harbo, Anders

    2006-01-01

    of Least Constraint using the Udwadia-Kalaba equation and can be used to model all body to body slung load suspension types. The model gives an intuitive and easy-to-use way of modelling and simulating di erent slung load suspension types and it includes detection and response of wire slacking......This paper presents the result of modelling and verification of a generic slung load system using a small-scale helicopter. The model is intended for use in simulation, pilot training, estimation, and control. The model is derived using a redundant coordinate formulation based on Gauss Principle...

  9. Modelling and Control of a Mobile Robot

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg

    1998-01-01

    In order to control a mobile robot, kinematic odels as well as dynamic models are required. This parer describes these basic models for an experimental mobile robot under construction at the Department of Control and Engineering Design. A description of a set of trajectory control rules is given...

  10. Smart Mobility Stakeholders - Curating Urban Data & Models

    Energy Technology Data Exchange (ETDEWEB)

    Sperling, Joshua [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-01

    This presentation provides an overview of the curation of urban data and models through engaging SMART mobility stakeholders. SMART Mobility Urban Science Efforts are helping to expose key data sets, models, and roles for the U.S. Department of Energy in engaging across stakeholders to ensure useful insights. This will help to support other Urban Science and broader SMART initiatives.

  11. Spreading the load: mobile information and communications technologies and their effect on information overload

    Directory of Open Access Journals (Sweden)

    D.K. Allan

    2005-01-01

    Full Text Available Introduction. We report on a small-scale research project which examined the impact of mobile technologies on the users' experience of information overload. The project focused on a group of worker who have had relatively little attention in both the mobile technology and information overload literatures: senior managers. Method. The case study approach was adopted, as complementary to an incremental approach to theory building. An inductive approach is adopted, in which data are collected and the findings are interpreted in the light of previous work. The case site was West Yorkshire Police Force in the UK where BlackBerry handhelds were being used by senior officers. Analysis. A semi-structured interview schedule was developed and applied in face-to-face interviews with the Senior Management Team and their secretaries. All interviews were recorded and the transcripts of the interviews analysed, using qualitative coding. Results. A conceptual model of the interactions and relationships among the key elements that drive and mediate the information flows and information behaviour within a complex organizational environment was developed. Managers' information behaviour and coping strategies were found to have changed since the introduction of mobile devices. Officers are more likely to deal with information received sooner, thereby resulting in less queuing of messages (although filtering strategies still prevail. Approximation (responding in a non-precise way was also found to have increased. In this particular implementation, the mobile technology has not altered the information-pull behaviour of managers. Conclusion. The main finding is that personal information management is now distributed more evenly throughout the day. Thus, the technology has enabled officers to 'spread the load' and, in doing so, has helped to ease some of the pressures created by information overload.

  12. Modeling sediment mobilization using a distributed hydrological model coupled with a bank stability model

    Science.gov (United States)

    Stryker, J.; Wemple, B.; Bomblies, A.

    2017-03-01

    In addition to surface erosion, stream bank erosion and failure contributes significant sediment and sediment-bound nutrients to receiving waters during high flow events. However, distributed and mechanistic simulation of stream bank sediment contribution to sediment loads in a watershed has not been achieved. Here we present a full coupling of existing distributed watershed and bank stability models and apply the resulting model to the Mad River in central Vermont. We fully coupled the Bank Stability and Toe Erosion Model (BSTEM) with the Distributed Hydrology Soil Vegetation Model (DHSVM) to allow the simulation of stream bank erosion and potential failure in a spatially explicit environment. We demonstrate the model's ability to simulate the impacts of unstable streams on sediment mobilization and transport within a watershed and discuss the model's capability to simulate watershed sediment loading under climate change. The calibrated model simulates total suspended sediment loads and reproduces variability in suspended sediment concentrations at watershed and subbasin outlets. In addition, characteristics such as land use and road-to-stream ratio of subbasins are shown to impact the relative proportions of sediment mobilized by overland erosion, erosion of roads, and stream bank erosion and failure in the subbasins and watershed. This coupled model will advance mechanistic simulation of suspended sediment mobilization and transport from watersheds, which will be particularly valuable for investigating the potential impacts of climate and land use changes, as well as extreme events.

  13. Final Project Report Load Modeling Transmission Research

    Energy Technology Data Exchange (ETDEWEB)

    Lesieutre, Bernard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bravo, Richard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yinger, Robert [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chassin, Dave [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Huang, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Ning [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hiskens, Ian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Venkataramanan, Giri [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-03-31

    The research presented in this report primarily focuses on improving power system load models to better represent their impact on system behavior. The previous standard load model fails to capture the delayed voltage recovery events that are observed in the Southwest and elsewhere. These events are attributed to stalled air conditioner units after a fault. To gain a better understanding of their role in these events and to guide modeling efforts, typical air conditioner units were testing in laboratories. Using data obtained from these extensive tests, new load models were developed to match air conditioner behavior. An air conditioner model is incorporated in the new WECC composite load model. These models are used in dynamic studies of the West and can impact power transfer limits for California. Unit-level and systemlevel solutions are proposed as potential solutions to the delayed voltage recovery problem.

  14. Wideband Tunable PIFA Antenna with Loaded Slot Structure for Mobile Handset and LTE Applications

    Directory of Open Access Journals (Sweden)

    I. Elfergani

    2014-04-01

    Full Text Available A compact planar inverted F antenna (PIFA with a tunable frequency response is presented. Tuning of the resonant frequency is realized by loading a varactor on an embedded slot of the proposed antenna structure without further optimizing other antenna geometry parameters. The antenna exhibits a wide frequency range from 1570 to 2600 MHz with a good impedance matching (S11 ≤-10 dB covering the GPS, PCS, DCS, UMTS, WLAN and LTE systems. To validate the theoretical model and design concept, the antenna prototype was fabricated and measured. The compact size of the antenna is 15mm × 8mm × 3mm, which makes this antenna a good candidate for mobile handset and wireless communication applications.

  15. Business Models for NFC based mobile payments

    Directory of Open Access Journals (Sweden)

    Johannes Sang Un Chae

    2015-01-01

    Full Text Available Purpose: The purpose of the paper is to develop a business model framework for NFC based mobile payment solutions consisting of four mutually interdepended components: the value service, value network, value architecture, and value finance. Design: Using a comparative case study method, the paper investigates Google Wallet and ISIS Mobile Wallet and their underlying business models. Findings: Google Wallet and ISIS Mobile Wallet are focusing on providing an enhanced customer experience with their mobile wallet through a multifaceted value proposition. The delivery of its offering requires cooperation from multiple stakeholders and the creation of an ecosystem. Furthermore, they focus on the scalability of their value propositions. Originality / value: The paper offers an applicable business model framework that allows practitioners and academics to study current and future mobile payment approaches.

  16. Business Models for NFC Based Mobile Payments

    DEFF Research Database (Denmark)

    Chae, Johannes Sang-Un; Hedman, Jonas

    2015-01-01

    from multiple stakeholders and the creation of an ecosystem. Furthermore, they focus on the scalability of their value propositions. Originality / value: The paper offers an applicable business model framework that allows practitioners and academics to study current and future mobile payment approaches.......Purpose: The purpose of the paper is to develop a business model framework for NFC based mobile payment solutions consisting of four mutually interdepended components: the value service, value network, value architecture, and value finance. Design: Using a comparative case study method, the paper...... investigates Google Wallet and ISIS Mobile Wallet and their underlying business models. Findings: Google Wallet and ISIS Mobile Wallet are focusing on providing an enhanced customer experience with their mobile wallet through a multifaceted value proposition. The delivery of its offering requires cooperation...

  17. Load-Aware Modeling and Analysis of Heterogeneous Cellular Networks

    CERN Document Server

    Dhillon, Harpreet S; Andrews, Jeffrey G

    2012-01-01

    Random spatial models are attractive for modeling heterogeneous cellular networks (HCNs) due to their realism, tractability, and scalability. A major limitation of such models to date in the context of HCNs is the neglect of network traffic and load: all base stations (BSs) have typically been assumed to always be transmitting. Small cells in particular will have a lighter load than macrocells, and so their contribution to the network interference may be significantly overstated in a fully loaded model. This paper incorporates a flexible notion of BS load by introducing a new idea of conditionally thinning the interference field. For a $K$-tier HCN where BSs across tiers differ in terms of transmit power, supported data rate, deployment density, and now load, we derive the coverage probability for a typical mobile, which connects to the strongest BS signal. Conditioned on this connection, the interfering BSs of the $i^{th}$ tier are assumed to transmit independently with probability $p_i$, which models the lo...

  18. Mobility-Aware and Load Balancing Based Clustering Algorithm for Energy Conservation in MANET

    Institute of Scientific and Technical Information of China (English)

    XU Li; ZHENG Bao-yu; GUO Gong-de

    2005-01-01

    Mobile ad hoc network (MANET) is one of wireless communication network architecture that has received a lot of attention. MANET is characterized by dynamic network topology and limited energy. With mobility-aware and load balancing based clustering algorithm (MLCA), this paper proposes a new topology management strategy to conserve energy. Performance simulation results show that the proposed MLCA strategy can balances the traffic load inside the whole network, so as to prolong the network lifetime, meanly, at the same time, achieve higher throughput ratio and network stability.

  19. Dynamic Modelling and Adaptive Traction Control for Mobile Robots

    Directory of Open Access Journals (Sweden)

    A. Albagul

    2008-11-01

    Full Text Available Mobile robots have received a great deal of research in recent years. A significant amount of research has been published in many aspects related to mobile robots. Most of the research is devoted to design and develop some control techniques for robot motion and path planning. A large number of researchers have used kinematic models to develop motion control strategy for mobile robots. Their argument and assumption that these models are valid if the robot has low speed, low acceleration and light load. However, dynamic modelling of mobile robots is very important as they are designed to travel at higher speed and perform heavy duty work. This paper presents and discusses a new approach to develop a dynamic model and control strategy for wheeled mobile robot which I modelled as a rigid body that roles on two wheels and a castor. The motion control strategy consists of two levels. The first level is dealing with the dynamic of the system and denoted as `Low' level controller. The second level is developed to take care of path planning and trajectory generation.

  20. Dynamic Modelling and Adaptive Traction Control for Mobile Robots

    Directory of Open Access Journals (Sweden)

    A. Albagul

    2004-09-01

    Full Text Available Mobile robots have received a great deal of research in recent years. A significant amount of research has been published in many aspects related to mobile robots. Most of the research is devoted to design and develop some control techniques for robot motion and path planning. A large number of researchers have used kinematic models to develop motion control strategy for mobile robots. Their argument and assumption that these models are valid if the robot has low speed, low acceleration and light load. However, dynamic modelling of mobile robots is very important as they are designed to travel at higher speed and perform heavy duty work. This paper presents and discusses a new approach to develop a dynamic model and control strategy for wheeled mobile robot which I modelled as a rigid body that roles on two wheels and a castor. The motion control strategy consists of two levels. The first level is dealing with the dynamic of the system and denoted as ‘Low’ level controller. The second level is developed to take care of path planning and trajectory generation.

  1. Information Service Model with Mobile Agent Supported

    Institute of Scientific and Technical Information of China (English)

    邹涛; 王继成; 张福炎

    2000-01-01

    Mobile Agent is a kind of novel agent technology characterized by mobile, intelligent, parallel and asynchronous computing. In this paper, a new information service model that adopts mobile agent technology is introduced first,and then an experimental system DOLTRIA system that is implemented based on the model is described. The DOLTRIA system implemented by WWW framework and Java can search for relevant HTML documents on a set of Web servers. The result of experiments shows that performance improvement can be achieved by this model, and both the elapsed time and network traffic are reduced significantly.

  2. Load-balancing algorithms for climate models

    Energy Technology Data Exchange (ETDEWEB)

    Foster, I.T.; Toonen, B.R.

    1994-06-01

    Implementations of climate models on scalable parallel computer systems can suffer from load imbalances due to temporal and spatial variations in the amount of computation required for physical parameterizations such as solar radiation and convective adjustment. We have developed specialized techniques for correcting such imbalances. These techniques are incorporated in a general-purpose, programmable load-balancing library that allows the mapping of computation to processors to be specified as a series of maps generated by a programmer-supplied load-balancing module. The communication required to move from one map to another is performed automatically by the library, without programmer intervention. In this paper, we de scribe the load-balancing problem and the techniques that we have developed to solve it. We also describe specific load-balancing algorithms that we have developed for PCCM2, a scalable parallel implementation of the community Climate Model, and present experimental results that demonstrate the effectiveness of these algorithms on parallel computers.

  3. Load-balancing algorithms for climate models

    Science.gov (United States)

    Foster, I. T.; Toonen, B. R.

    Implementations of climate models on scalable parallel computer systems can suffer from load imbalances due to temporal and spatial variations in the amount of computation required for physical parameterizations such as solar radiation and convective adjustment. We have developed specialized techniques for correcting such imbalances. These techniques are incorporated in a general-purpose, programmable load-balancing library that allows the mapping of computation to processors to be specified as a series of maps generated by a programmer-supplied load-balancing module. The communication required to move from one map to another is performed automatically by the library, without programmer intervention. In this paper, we describe the load-balancing problem and the techniques that we have developed to solve it. We also describe specific load-balancing algorithms that we have developed for PCCM2, a scalable parallel implementation of the community climate model, and present experimental results that demonstrate the effectiveness of these algorithms on parallel computers.

  4. Model checking mobile stochastic logic.

    NARCIS (Netherlands)

    De Nicola, Rocco; Katoen, Joost P.; Latella, Diego; Loreti, Michele; Massink, Mieke

    2007-01-01

    The Temporal Mobile Stochastic Logic (MOSL) has been introduced in previous work by the authors for formulating properties of systems specified in STOKLAIM, a Markovian extension of KLAIM. The main purpose of MOSL is to address key functional aspects of global computing such as distribution

  5. Model checking mobile stochastic logic.

    NARCIS (Netherlands)

    De Nicola, Rocco; Katoen, Joost-Pieter; Latella, Diego; Loreti, Michele; Massink, Mieke

    2007-01-01

    The Temporal Mobile Stochastic Logic (MOSL) has been introduced in previous work by the authors for formulating properties of systems specified in STOKLAIM, a Markovian extension of KLAIM. The main purpose of MOSL is to address key functional aspects of global computing such as distribution awarenes

  6. Modeling and control of thermostatically controlled loads

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, Scott N [Los Alamos National Laboratory; Sinitsyn, Nikolai [Los Alamos National Laboratory; Kundu, S. [UNIV OF MICHIGAN; Hiskens, I. [UNIV OF MICHIGAN

    2011-01-04

    As the penetration of intermittent energy sources grows substantially, loads will be required to play an increasingly important role in compensating the fast time-scale fluctuations in generated power. Recent numerical modeling of thermostatically controlled loads (TCLs) has demonstrated that such load following is feasible, but analytical models that satisfactorily quantify the aggregate power consumption of a group of TCLs are desired to enable controller design. We develop such a model for the aggregate power response of a homogeneous population of TCLs to uniform variation of all TCL setpoints. A linearized model of the response is derived, and a linear quadratic regulator (LQR) has been designed. Using the TCL setpoint as the control input, the LQR enables aggregate power to track reference signals that exhibit step, ramp and sinusoidal variations. Although much of the work assumes a homogeneous population of TCLs with deterministic dynamics, we also propose a method for probing the dynamics of systems where load characteristics are not well known.

  7. Measurements and Modelling of Base Station Power Consumption under Real Traffic Loads

    Directory of Open Access Journals (Sweden)

    Goran Petrovic

    2012-03-01

    Full Text Available Base stations represent the main contributor to the energy consumption of a mobile cellular network. Since traffic load in mobile networks significantly varies during a working or weekend day, it is important to quantify the influence of these variations on the base station power consumption. Therefore, this paper investigates changes in the instantaneous power consumption of GSM (Global System for Mobile Communications and UMTS (Universal Mobile Telecommunications System base stations according to their respective traffic load. The real data in terms of the power consumption and traffic load have been obtained from continuous measurements performed on a fully operated base station site. Measurements show the existence of a direct relationship between base station traffic load and power consumption. According to this relationship, we develop a linear power consumption model for base stations of both technologies. This paper also gives an overview of the most important concepts which are being proposed to make cellular networks more energy-efficient.

  8. Modelling and Simulation of Wave Loads

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    A simple model of the wave load on slender members of offshore structures is described. The wave elevation of the sea state is modelled by a stationary Gaussian process. A new procedure to simulate realizations of the wave loads is developed. The simulation method assumes that the wave particle...... velocity can be approximated by a Gaussian Markov process. Known approximate results for the first-passage density or equivalently, the distribution of the extremes of wave loads are presented and compared with rather precise simulation results. It is demonstrated that the approximate results...

  9. Modelling and Simulation of Wave Loads

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1985-01-01

    A simple model of the wave load on stender members of offshore structures is described . The wave elevation of the sea stateis modelled by a stationary Gaussian process. A new procedure to simulate realizations of the wave loads is developed. The simulation method assumes that the wave particle...... velocity can be approximated by a Gaussian Markov process. Known approximate results for the first passage density or equivalently, the distribution of the extremes of wave loads are presented and compared with rather precise simulation results. It is demonstrated that the approximate results...

  10. A secure operational model for mobile payments.

    Science.gov (United States)

    Chang, Tao-Ku

    2014-01-01

    Instead of paying by cash, check, or credit cards, customers can now also use their mobile devices to pay for a wide range of services and both digital and physical goods. However, customers' security concerns are a major barrier to the broad adoption and use of mobile payments. In this paper we present the design of a secure operational model for mobile payments in which access control is based on a service-oriented architecture. A customer uses his/her mobile device to get authorization from a remote server and generate a two-dimensional barcode as the payment certificate. This payment certificate has a time limit and can be used once only. The system also provides the ability to remotely lock and disable the mobile payment service.

  11. A Secure Operational Model for Mobile Payments

    Directory of Open Access Journals (Sweden)

    Tao-Ku Chang

    2014-01-01

    Full Text Available Instead of paying by cash, check, or credit cards, customers can now also use their mobile devices to pay for a wide range of services and both digital and physical goods. However, customers’ security concerns are a major barrier to the broad adoption and use of mobile payments. In this paper we present the design of a secure operational model for mobile payments in which access control is based on a service-oriented architecture. A customer uses his/her mobile device to get authorization from a remote server and generate a two-dimensional barcode as the payment certificate. This payment certificate has a time limit and can be used once only. The system also provides the ability to remotely lock and disable the mobile payment service.

  12. Modelling of Generic Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; Bendtsen, Jan Dimon; La Cour-Harbo, Anders

    2006-01-01

    This paper presents the result of modelling and verification of a generic slung load system using a small-scale helicopter. The model is intended for use in simulation, pilot training, estimation, and control. The model is derived using a redundant coordinate formulation based on Gauss Principle ...

  13. Load Balancing Based on Anycast and Pseudo-Mobility in IPv6

    Institute of Scientific and Technical Information of China (English)

    FENGYanjun; SONGCheng; KANZhigang; MAJian; YERunguo

    2004-01-01

    We proposed a new Load balancing mechanism, called LBAM (Load balancing based on anycast and pseudo-mobility in IPv6), by which sessions can be distributed across a pool of servers for maximum performance. Load balancing is needed in many fields, such as Web server, FTP (File transfer protocol) server and NAT-PT (Network address translation-protocol translation) gateway, and there exist several approaches for load balancing. However, current approaches have problems such as poor scalability, inability to balance session flow,long latency time, and topological constraint on server pools. In this paper, we describe how LBAM works in principle without the above problems. We also present our simulation work using NS-2 and discuss performance comparison between LBAM and other load balancing mechanisms. The results show that LBAM has very advanced performance and scalability. Finally, the ubiquitous applications of LBAM in NGI (Next generation Internet) are presented.

  14. Stochastic Load Models and Footbridge Response

    DEFF Research Database (Denmark)

    Pedersen, Lars; Frier, Christian

    2015-01-01

    Pedestrians may cause vibrations in footbridges and these vibrations may potentially be annoying. This calls for predictions of footbridge vibration levels and the paper considers a stochastic approach to modeling the action of pedestrians assuming walking parameters such as step frequency...... the footbridge and when describing the action of the pedestrians (such as for instance the number of load harmonics). Focus is on estimating vertical structural response to single person loading....

  15. Gust modelling for wind loading

    NARCIS (Netherlands)

    Verheij, F.J.; Cleijne, J.W.; Leene, J.A.

    1992-01-01

    In this paper the TNO gust analysis method and the resulting TNO gust model are described. The method has been applied to a set of 700 hours of stationary wind speed time series measured at the meteorological mast at Cabauw, The Netherlands. The results are discussed in this paper. The TNO gust mode

  16. Gust modelling for wind loading

    NARCIS (Netherlands)

    Verheij, F.J.; Cleijne, J.W.; Leene, J.A.

    1992-01-01

    In this paper the TNO gust analysis method and the resulting TNO gust model are described. The method has been applied to a set of 700 hours of stationary wind speed time series measured at the meteorological mast at Cabauw, The Netherlands. The results are discussed in this paper. The TNO gust

  17. Risk Assessment Model for Mobile Malware

    Directory of Open Access Journals (Sweden)

    George Stanescu

    2015-03-01

    Full Text Available The mobile technology is considered to be the fastest-developing IT security area. Only in the last year security threats around mobile devices have reached new heights in terms of both quality and quantity. The speed of this development has made possible several types of security attacks that, until recently, were only possible on computers. In terms of the most targeted mobile operating systems, Android continues to be the most vulnerable, although new ways of strengthening its security model were introduced by Google. The aim of this article is to provide a model for assessing the risk of mobile infection with malware, starting from a statistical analysis of the permissions required by each application installed into the mobile system. The software implementation of this model will use the Android operating system and in order to do so, we will start by analyzing its permission-based security architecture. Furthermore, based on statistical data regarding the most dangerous permissions, we build the risk assessment model and, to prove its efficiency, we scan some of the most popular apps and interpret the results. To this end, we offer an overview of the strengths and weaknesses of this permission-based model and we also state a short conclusion regarding model’s efficiency.

  18. Modeling and Engineering Algorithms for Mobile Data

    DEFF Research Database (Denmark)

    Blunck, Henrik; Hinrichs, Klaus; Sondern, Joëlle;

    2006-01-01

    In this paper, we present an object-oriented approach to modeling mobile data and algorithms operating on such data. Our model is general enough to capture any kind of continuous motion while at the same time allowing for encompassing algorithms optimized for specific types of motion. Such motion...

  19. Sensitivity of Footbridge Response to Load Modeling

    DEFF Research Database (Denmark)

    Pedersen, Lars; Frier, Christian

    The paper considers a stochastic approach to modeling the actions of walking and has focus on the vibration serviceability limit state of footbridges. The use of a stochastic approach is novel but useful as it is more advanced than the quite simplistic deterministic load models seen in many desig...... matter to foresee their impact. The paper contributes by examining how some of these decisions influence the outcome of serviceability evaluations. The sensitivity study is made focusing on vertical footbridge response to single person loading....

  20. Sensitivity of Footbridge Response to Load Modeling

    DEFF Research Database (Denmark)

    Pedersen, Lars; Frier, Christian

    2012-01-01

    The paper considers a stochastic approach to modeling the actions of walking and has focus on the vibration serviceability limit state of footbridges. The use of a stochastic approach is novel but useful as it is more advanced than the quite simplistic deterministic load models seen in many design...... matter to foresee their impact. The paper contributes by examining how some of these decisions influence the outcome of serviceability evaluations. The sensitivity study is made focusing on vertical footbridge response to single person loading....

  1. Sensitivity of Footbridge Response to Load Modeling

    DEFF Research Database (Denmark)

    Pedersen, Lars; Frier, Christian

    The paper considers a stochastic approach to modeling the actions of walking and has focus on the vibration serviceability limit state of footbridges. The use of a stochastic approach is novel but useful as it is more advanced than the quite simplistic deterministic load models seen in many design...... matter to foresee their impact. The paper contributes by examining how some of these decisions influence the outcome of serviceability evaluations. The sensitivity study is made focusing on vertical footbridge response to single person loading....

  2. Predicting Footbridge Response using Stochastic Load Models

    DEFF Research Database (Denmark)

    Pedersen, Lars; Frier, Christian

    2013-01-01

    Walking parameters such as step frequency, pedestrian mass, dynamic load factor, etc. are basically stochastic, although it is quite common to adapt deterministic models for these parameters. The present paper considers a stochastic approach to modeling the action of pedestrians, but when doing s...... as it pinpoints which decisions to be concerned about when the goal is to predict footbridge response. The studies involve estimating footbridge responses using Monte-Carlo simulations and focus is on estimating vertical structural response to single person loading....

  3. Mobile agents basic concepts, mobility models, and the tracy toolkit

    CERN Document Server

    Braun, Peter

    2005-01-01

    Mobile agents are software nomads that act as your personal representative, working autonomously through networks. They are able to visit network nodes directly using available computing power and are not limited by platform. This emerging field is now poised to become a cornerstone for new Web-based ubiquitous computing environments. Mobile Agents provides a practical introduction to mobile agent technology and surveys the state of the art in mobile agent research. Students and researchers can use the book as an introduction to the concepts and possibilities of this field and as an overview of ongoing research. Developers can use it to identify the capabilities of the technology to decide if mobile agents are the right solution for them. Practioners can also gain hands-on experience in programming mobile agents through exploration of the source code for a complete mobile agent environment available through the companion website.*Summarizes the state of the art in mobile agent research*Identifies the benefits...

  4. Effect of mobility models on infrastructure based wireless networks ...

    African Journals Online (AJOL)

    Effect of mobility models on infrastructure based wireless networks. ... In this paper, the effect of handoff procedure on the performance of random mobile nodes in wireless networks was investigated. Mobility of node is defined ... Article Metrics.

  5. Multi-Layer Mobility Load Balancing in a Heterogeneous LTE Network

    DEFF Research Database (Denmark)

    Fotiadis, Panagiotis; Polignano, Michele; Laselva, Daniela;

    2012-01-01

    This paper analyzes the behavior of a distributed Mobility Load Balancing (MLB) scheme in a multi-layer 3GPP (3rd Generation Partnership Project) Long Term Evolution (LTE) deployment with different User Equipment (UE) densities in certain network areas covered with pico cells. Target of the study...... user performance. Results have shown that the proposed MLB scheme can significantly improve the overall network resources utilization by eliminating potential load imbalances amongst the deployment layers and consequently enhance user experience. However this occurs at the cost of increased Radio Link...

  6. WiBro Mobility Simulation Model

    Directory of Open Access Journals (Sweden)

    Junaid Qayyum

    2011-09-01

    Full Text Available WiBro, or Wireless Broadband, is the newest variety of mobile wireless broadband access. WiBro technology is being developed by the Korean Telecoms industry. It is based on the IEEE 802.16e (Mobile WiMax international standard. Korean based fixed-line operators KT, SK Telecom were the first to get the licenses by the South Korean government to provide WiBro Commercially. Samsung had a demonstration on WiBro Mobile Phones and Systems at the "APEC IT Exhibition 2006". WiBro is comprised of two phases namely WiBro Phase I and WiBro Phase II. Samsung Electronics has been extensively contributing to Koreas WiBro (Wireless Broadband initiative as well as the IEEE 802.16 standards. The WiBro is a specific subset of the 802.16 standards, specially focusing on supporting full mobility of wireless access systems with OFDMA PHY interface. In this work, we have developed a simulation model of the WiBro system consisting of a set of Base Stations and Mobile Subscriber Stations by using the OPNET Modeler. The simulation model has been utilized to evaluate effective MAC layer throughput, resource usage efficiency, QoS class differentiation, and system capacity and performance under various simulation scenarios.

  7. Modelling dengue epidemic spreading with human mobility

    Science.gov (United States)

    Barmak, D. H.; Dorso, C. O.; Otero, M.

    2016-04-01

    We explored the effect of human mobility on the spatio-temporal dynamics of Dengue with a stochastic model that takes into account the epidemiological dynamics of the infected mosquitoes and humans, with different mobility patterns of the human population. We observed that human mobility strongly affects the spread of infection by increasing the final size and by changing the morphology of the epidemic outbreaks. When the spreading of the disease is driven only by mosquito dispersal (flight), a main central focus expands diffusively. On the contrary, when human mobility is taken into account, multiple foci appear throughout the evolution of the outbreaks. These secondary foci generated throughout the outbreaks could be of little importance according to their mass or size compared with the largest main focus. However, the coalescence of these foci with the main one generates an effect, through which the latter develops a size greater than the one obtained in the case driven only by mosquito dispersal. This increase in growth rate due to human mobility and the coalescence of the foci are particularly relevant in temperate cities such as the city of Buenos Aires, since they give more possibilities to the outbreak to grow before the arrival of the low-temperature season. The findings of this work indicate that human mobility could be the main driving force in the dynamics of vector epidemics.

  8. Load test with the mobile telescopic crane (160 T) for handling LHC magnets

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    CERN has taken delivery of a new telescopic mobile crane. The new crane will be required to load LHC dipole magnets made in Building SM18 onto a trailer that will take them to the Prévessin site, where they will be put in storage until they can be lowered into the tunnel. It has passed its first operating tests, which consisted of lifting a 37-tonne concrete block.

  9. The Syntax Model of Mobile Maps Generation

    Directory of Open Access Journals (Sweden)

    TIAN Jiangpeng

    2016-11-01

    Full Text Available Using the method of formal language (FL, the syntax model of mobile map generation is studied. The syntax model is located in the level of logical calculus of map generation based on the analysis of its process. Combined the hierarchical and recursive characteristics of map representation, the simplest form of syntax structure is abstracted as carto-lexicons and syntax-rules. The classification system of carto-lexicons is established as well as the model of the spatial relation predicate system, and the map operation rules and rules of different levels of syntactic units are discussed. The compilation process and key techniques of the syntax model are discussed, and the feasibility of the model is verified through mobile maps generation experiment. The essence of the model is a kind of formal language grammar, which uses finite rules and lexicons to generate maps automatically, as well as a kind of high-level cartography interface of human-computer interactive.

  10. Load sharing in models with communication delays

    NARCIS (Netherlands)

    Geest, R.A.B. van der

    1994-01-01

    Computer systems may be connected in a network to share workload. A control problem then is to decide which computer should carry out which task. Novel in this report is a model for load sharing with communication delays. It takes nonnegligible time for information from one computer to reach the oth

  11. Electricity load modelling using computational intelligence

    NARCIS (Netherlands)

    Ter Borg, R.W.

    2005-01-01

    As a consequence of the liberalisation of the electricity markets in Europe, market players have to continuously adapt their future supply to match their customers' demands. This poses the challenge of obtaining a predictive model that accurately describes electricity loads, current in this thesis.

  12. An Efficient Admission Control Algorithm for Load Balancing In Hierarchical Mobile IPv6 Networks

    CERN Document Server

    Harini, Prof P

    2009-01-01

    In hierarchical Mobile IPv6 networks, Mobility Anchor Point (MAP) may become a single point of bottleneck as it handles more and more mobile nodes (MNs). A number of schemes have been proposed to achieve load balancing among different MAPs. However, signaling reduction is still imperfect because these schemes also avoid the effect of the number of CNs. Also only the balancing of MN is performed, but not the balancing of the actual traffic load, since CN of each MN may be different. This paper proposes an efficient admission control algorithm along with a replacement mechanism for HMIPv6 networks. The admission control algorithm is based on the number of serving CNs and achieves actual load balancing among MAPs. Moreover, a replacement mechanism is introduced to decrease the new MN blocking probability and the handoff MN dropping probability. By simulation results, we show that, the handoff delay and packet loss are reduced in our scheme, when compared with the standard HMIPv6 based handoff.

  13. General Ripple Mobility Model: A Novel Mobility Model of Uniform Spatial Distribution and Diverse Average Speed

    Science.gov (United States)

    Chen, Chun-Hung; Wu, Ho-Ting; Ke, Kai-Wei

    Simulations are often deployed to evaluate proposed mechanisms or algorithms in Mobile Ad Hoc Networks (MANET). In MANET, the impacts of some simulation parameters are noticeable, such as transmission range, data rate etc. However, the effect of mobility model is not clear until recently. Random Waypoint (RWP) is one of the most applied nodal mobility models in many simulations due to its clear procedures and easy employments. However, it exhibits the two major problems: decaying average speed and border effect. Both problems will overestimate the performance of the employed protocols and applications. Although many recently proposed mobility models are able to reduce or eliminate the above-mentioned problems, the concept of Diverse Average Speed (DAS) has not been introduced. DAS aims to provide different average speeds within the same speed range. In most mobility models, the average speed is decided when the minimum and maximum speeds are set. In this paper, we propose a novel mobility model, named General Ripple Mobility Model (GRMM). GRMM targets to provide a uniform nodal spatial distribution and DAS without decaying average speed. The simulations and analytic results have demonstrated the merits of the outstanding properties of the GRMM model.

  14. Measurement-based load modeling: Theory and application

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Load model is one of the most important elements in power system operation and control. However, owing to its complexity, load modeling is still an open and very difficult problem. Summarizing our work on measurement-based load modeling in China for more than twenty years, this paper systematically introduces the mathematical theory and applications regarding the load modeling. The flow chart and algorithms for measurement-based load modeling are presented. A composite load model structure with 13 parameters is also proposed. Analysis results based on the trajectory sensitivity theory indicate the importance of the load model parameters for the identification. Case studies show the accuracy of the presented measurement-based load model. The load model thus built has been validated by field measurements all over China. Future working directions on measurement- based load modeling are also discussed in the paper.

  15. MODELLING DYNAMIC PATTERNS USING MOBILE DATA

    Directory of Open Access Journals (Sweden)

    uhad Faisal Behadili

    2016-01-01

    Full Text Available Understanding, modeling and simulating human mobility among urban regions is very challengeable effort. It is very important in rescue situations for many kinds of events, either in the indoor events like evacuation of buildings or outdoor ones like public assemblies, community evacuation, in exigency situations there are several incidents could be happened, the overcrowding causes injuries and death cases, which are emerged during emergency situations, as well as it serves urban planning and smart cities. The aim of this study is to explore the characteristics of human mobility patterns, and model them mathematically depending on inter-event time and traveled distances (displacements parameters by using CDRs (Call Detailed Records during Armada festival in France. However, the results of the numerical simulation endorse the other studies findings in that the most of real systems patterns are almost follows an exponential distribution. In the future the mobility patterns could be classified according (work or off days, and the radius of gyration could be considered as effective parameter in modelling human mobility.

  16. Learning anatomy via mobile augmented reality: Effects on achievement and cognitive load.

    Science.gov (United States)

    Küçük, Sevda; Kapakin, Samet; Göktaş, Yüksel

    2016-10-01

    Augmented reality (AR), a new generation of technology, has attracted the attention of educators in recent years. In this study, a MagicBook was developed for a neuroanatomy topic by using mobile augmented reality (mAR) technology. This technology integrates virtual learning objects into the real world and allow users to interact with the environment using mobile devices. The purpose of this study was to determine the effects of learning anatomy via mAR on medical students' academic achievement and cognitive load. The mixed method was applied in the study. The random sample consisted of 70 second-year undergraduate medical students: 34 in an experimental group and 36 in a control group. Academic achievement test and cognitive load scale were used as data collection tool. A one-way MANOVA test was used for analysis. The experimental group, which used mAR applications, reported higher achievement and lower cognitive load. The use of mAR applications in anatomy education contributed to the formation of an effective and productive learning environment. Student cognitive load decreased as abstract information became concrete in printed books via multimedia materials in mAR applications. Additionally, students were able to access the materials in the MagicBook anytime and anywhere they wanted. The mobile learning approach helped students learn better by exerting less cognitive effort. Moreover, the sensory experience and real time interaction with environment may provide learning satisfaction and enable students to structure their knowledge to complete the learning tasks. Anat Sci Educ 9: 411-421. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

  17. Investigation of Control Algorithms for Tracked Vehicle Mobility Load Emulation for a Combat Hybrid Electric Power System

    Science.gov (United States)

    2009-07-30

    Investigation of Control Algorithms for Tracked Vehicle Mobility Load Emulation for a Combat Hybrid Electric Power System Jarrett Goodell and...TITLE AND SUBTITLE Investigation of Control Algorithms for Tracked Vehicle Mobility Load Emulation for a Combat Hybrid Electric Power System 5a...for ~ 22 ton tracked vehicle • Tested and Developed: – Motors, Generators, Batteries, Inverters, DC-DC Converters , Thermal Management, Pulse Power

  18. Sensitivity Study of Stochastic Walking Load Models

    DEFF Research Database (Denmark)

    Pedersen, Lars; Frier, Christian

    2010-01-01

    On flexible structures such as footbridges and long-span floors, walking loads may generate excessive structural vibrations and serviceability problems. The problem is increasing because of the growing tendency to employ long spans in structural design. In many design codes, the vibration...... serviceability limit state is assessed using a walking load model in which the walking parameters are modelled deterministically. However, the walking parameters are stochastic (for instance the weight of the pedestrian is not likely to be the same for every footbridge crossing), and a natural way forward...... investigates whether statistical distributions of bridge response are sensitive to some of the decisions made by the engineer doing the analyses. For the paper a selected part of potential influences are examined and footbridge responses are extracted using Monte-Carlo simulations and focus is on estimating...

  19. Modeling of STATCOM under different loading conditions

    DEFF Research Database (Denmark)

    George, G.J.; Ramachandran, Rakesh; Kowsalya, M.

    2012-01-01

    This paper deals with the study and analysis of Flexible AC Transmission Systems (FACTS), mainly the modeling of STATCOM. Reactive Power Compensation plays a very important role in the transmission of Electric Power. A comparative study of how the reactive power is injected into the transmission ...... system with and without STATCOM under different loading condition is also illustrated in this paper. Simulations are performed using MATLAB/SIMULINK software. © 2012 IEEE....

  20. A unified algorithm for mobility load balancing in 3GPP LTE multi-cell networks

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; LIU Nan; LI ZhiHang; WU Ping; PAN ZhiWen; YOU XiaoHu

    2013-01-01

    3GPP long term evolution (LTE) is a promising candidate for the next-generation wireless network, which is expected to achieve high spectrum efficiency by using advanced physical layer techniques and flat network structures. However, the LTE network still faces the problem of load imbalance as in GSM/WCDMA networks, and this may cause significant deterioration of system performance. To deal with this problem, mobility load balancing (MLB) has been proposed as an important use case in 3GPP self-organizing network (SON), in which the serving cell of a user can be selected to achieve load balancing rather than act as the cell with the maximum received power. Furthermore, the LTE network aims to serve users with different quality-of-service (QoS) requirements, and the network-wide objective function for load balancing is distinct for different kinds of users. Thus, in this paper, a unified algorithm is proposed for MLB in the LTE network. The load balancing problem is first formulated as an optimization problem with the optimizing variables being cell-user connections. Then the complexity and overhead of the optimal solution is analyzed and a practical and distributed algorithm is given. After that, the proposed algorithm is evaluated for users with different kinds of QoS requirements, i.e., guaranteed bit rate (GBR) users with the objective function of load balance index and non-GBR (nGBR) users with the objective function of total utility, respectively. Simulation results show that the proposed algorithm leads to significantly balanced load distribution for GBR users to decrease the new call blocking rate, and for nGBR users to improve the cell-edge throughput at the cost of only slight deterioration of total throughput.

  1. Hybrid model for wireless mobility management using IPv6

    Science.gov (United States)

    Howie, Douglas P.; Sun, Junzhao; Koivisto, Antti T.

    2001-07-01

    Within the coming decade, there will be a dramatic increase in the availability of inexpensive, computationally powerful mobile devices running applications which use the Internet Protocol (IP) to access multimedia services over broad-band wireless connections. To this end, there has been extensive research and standardization in the areas of Mobile IP and IPv6. The purpose of this paper is to apply this work to the issues involved in designing a mobility model able to adapt to different wireless mobile IP scenarios. We describe the usefulness of this model in the 4th generation mobile multimedia systems to come. This new model has been synthesized through a comparative analysis of current mobile IP models where particular attention has been given to the problems of mobile IP handoff and mobility management and their impact on QoS. By applying a unique perspective to these problems, our model is used to set a roadmap for future mobile IPv6 testbed construction.

  2. Modeling neck mobility in fossil turtles.

    Science.gov (United States)

    Werneburg, Ingmar; Hinz, Juliane K; Gumpenberger, Michaela; Volpato, Virginie; Natchev, Nikolay; Joyce, Walter G

    2015-05-01

    Turtles have the unparalleled ability to retract their heads and necks within their shell but little is known about the evolution of this trait. Extensive analysis of neck mobility in turtles using radiographs, CT scans, and morphometry reveals that basal turtles possessed less mobility in the neck relative to their extant relatives, although the anatomical prerequisites for modern mobility were already established. Many extant turtles are able to achieve hypermobility by dislocating the central articulations, which raises cautions about reconstructing the mobility of fossil vertebrates. A 3D-model of the Late Triassic turtle Proganochelys quenstedti reveals that this early stem turtle was able to retract its head by tucking it sideways below the shell. The simple ventrolateral bend seen in this stem turtle, however, contrasts with the complex double-bend of extant turtles. The initial evolution of neck retraction therefore occurred in a near-synchrony with the origin of the turtle shell as a place to hide the unprotected neck. In this early, simplified retraction mode, the conical osteoderms on the neck provided further protection. © 2014 Wiley Periodicals, Inc.

  3. Mobile Modelling for Crowdsourcing Building Interior Data

    Science.gov (United States)

    Rosser, J.; Morley, J.; Jackson, M.

    2012-06-01

    Indoor spatial data forms an important foundation to many ubiquitous computing applications. It gives context to users operating location-based applications, provides an important source of documentation of buildings and can be of value to computer systems where an understanding of environment is required. Unlike external geographic spaces, no centralised body or agency is charged with collecting or maintaining such information. Widespread deployment of mobile devices provides a potential tool that would allow rapid model capture and update by a building's users. Here we introduce some of the issues involved in volunteering building interior data and outline a simple mobile tool for capture of indoor models. The nature of indoor data is inherently private; however in-depth analysis of this issue and legal considerations are not discussed in detail here.

  4. Towards More Realistic Mobility Model in Vehicular Ad Hoc Network

    OpenAIRE

    Dhananjay S. Gaikwad; Mahesh Lagad; Prashant Suryawanshi; Vaibhav Maske

    2012-01-01

    Mobility models or the movement patterns of nodes communicating wirelessely, play a vital role in the simulation-based evaluation of vehicular Ad Hoc Networks (VANETs). Even though recent research has developed models that better corresponds to real world mobility, we still have a limited understanding of the level of the required level of mobility details for modeling and simulating VANETs. In this paper, we propose a new mobility model for VANETs that works on the city area and map the topo...

  5. Topobathymetric model of Mobile Bay, Alabama

    Science.gov (United States)

    Danielson, Jeffrey J.; Brock, John C.; Howard, Daniel M.; Gesch, Dean B.; Bonisteel-Cormier, Jamie M.; Travers, Laurinda J.

    2013-01-01

    Topobathymetric Digital Elevation Models (DEMs) are a merged rendering of both topography (land elevation) and bathymetry (water depth) that provides a seamless elevation product useful for inundation mapping, as well as for other earth science applications, such as the development of sediment-transport, sea-level rise, and storm-surge models. This 1/9-arc-second (approximately 3 meters) resolution model of Mobile Bay, Alabama was developed using multiple topographic and bathymetric datasets, collected on different dates. The topographic data were obtained primarily from the U.S. Geological Survey (USGS) National Elevation Dataset (NED) (http://ned.usgs.gov/) at 1/9-arc-second resolution; USGS Experimental Advanced Airborne Research Lidar (EAARL) data (2 meters) (http://pubs.usgs.gov/ds/400/); and topographic lidar data (2 meters) and Compact Hydrographic Airborne Rapid Total Survey (CHARTS) lidar data (2 meters) from the U.S. Army Corps of Engineers (USACE) (http://www.csc.noaa.gov/digitalcoast/data/coastallidar/). Bathymetry was derived from digital soundings obtained from the National Oceanic and Atmospheric Administration’s (NOAA) National Geophysical Data Center (NGDC) (http://www.ngdc.noaa.gov/mgg/geodas/geodas.html) and from water-penetrating lidar sources, such as EAARL and CHARTS. Mobile Bay is ecologically important as it is the fourth largest estuary in the United States. The Mobile and Tensaw Rivers drain into the bay at the northern end with the bay emptying into the Gulf of Mexico at the southern end. Dauphin Island (a barrier island) and the Fort Morgan Peninsula form the mouth of Mobile Bay. Mobile Bay is 31 miles (50 kilometers) long by a maximum width of 24 miles (39 kilometers) with a total area of 413 square miles (1,070 square kilometers). The vertical datum of the Mobile Bay topobathymetric model is the North American Vertical Datum of 1988 (NAVD 88). All the topographic datasets were originally referenced to NAVD 88 and no transformations

  6. Modeling cell dynamics under mobile phone radiation.

    Science.gov (United States)

    Minelli, Tullio Antonio; Balduzzo, Maurizio; Milone, Francesco Ferro; Nofrate, Valentina

    2007-04-01

    Perturbations by pulse-modulated microwave radiation from GSM mobile phones on neuron cell membrane gating and calcium oscillations have been suggested as a possible mechanism underlying activation of brain states and electroencephalographic epiphenomena. As the employ of UMTS phones seems to reveal other symptoms, a unified phenomenological framework is needed. In order to explain possible effects of mobile phone radiation on cell oscillations, GSM and UMTS low-frequency envelopes have been detected, recorded and used as input in cell models. Dynamical systems endowed with contiguous regular and chaotic regimes suitable to produce stochastic resonance can both account for the perturbation of the neuro-electrical activity and even for the low intensity of the signal perceived by high sensitive subjects. Neuron models of this kind can be employed as a reductionist hint for the mentioned phenomenology. The Hindmarsh-Rose model exhibits frequency enhancement and regularization phenomena induced by weak GSM and UMTS. More realistic simulations of cell membrane gating and calcium oscillations have been performed with the help of an adaptation of the Chay-Keizer dynamical system. This scheme can explain the suspected subjective sensitivity to mobile phone signals under the thermal threshold, in terms of cell calcium regularity mechanisms. Concerning the two kinds of emission, the stronger occupation of the ELF band of last generation UMTS phones is compensated by lower power emitted.

  7. Modelling an Institutional Mobile Learning Readiness Analyser

    Science.gov (United States)

    Ireri, Bonface Ngari; Omwenga, Elijah I.

    2015-01-01

    Due to the affordability, ease of use and availability of mobile devices, many people in Africa and developing countries have acquired at least a mobile device. The penetration of mobile devices places many learning institution in a position to adopt mobile learning, however there are few tools for measuring mobile learning readiness for an…

  8. Dynamic Axle Load of an Automotive Vehicle When Driven on a Mobile Measurement Platform

    Directory of Open Access Journals (Sweden)

    Jagiełowicz-Ryznar C.

    2014-08-01

    Full Text Available An analysis of the dynamic axle load of an automotive vehicle (AV when it is driven on a mobile measurement platform is presented in this paper. During the ride, the time characteristic of the dynamic force N(t, acting on the axle, was recorded. The effect of the vehicle axle mass on the maximum dynamic force value and the dynamic coefficient were studied. On this basis it was attempted to calculate the total vehicle’s weight. Conclusions concerning the dynamic loads of the vehicle axles in relation to the reduced axle mass, were drawn. The optimal axle mass value, for which the dynamic coefficient reaches a minimum, was calculated

  9. E-Commerce Mobile Marketing Model Resolving Users Acceptance Criteria

    Directory of Open Access Journals (Sweden)

    Veronica S. Moertini

    2012-12-01

    Full Text Available The growth of e-commerce and mobile services has been creating business opportunities. Among these,mobile marketing is predicted to be a new trend of marketing. As mobile devices are personal tools suchthat the services ought to be unique, in the last few years, researches have been conducted studies relatedto the user acceptance of mobile services and produced results. This research aims to develop a model ofmobile e-commerce mobile marketing system, in the form of computer-based information system (CBISthat addresses the recommendations or criteria formulated by researchers. In this paper, the criteriaformulated by researches are presented then each of the criteria is resolved and translated into mobileservices. A model of CBIS, which is an integration of a website and a mobile application, is designed tomaterialize the mobile services. The model is presented in the form of business model, system procedures,network topology, software model of the website and mobile application, and database models.

  10. Using NASTRAN to model missile inertia loads

    Science.gov (United States)

    Marvin, R.; Porter, C.

    1985-01-01

    An important use of NASTRAN is in the area of structural loads analysis on weapon systems carried aboard aircraft. The program is used to predict bending moments and shears in missile bodies, when subjected to aircraft induced accelerations. The missile, launcher and aircraft wing are idealized, using rod and beam type elements for solution economy. Using the inertia relief capability of NASTRAN, the model is subjected to various acceleration combinations. It is found to be difficult to model the launcher sway braces and hooks which transmit compression only or tension only type forces respectively. A simple, iterative process was developed to overcome this modeling difficulty. A proposed code modification would help model compression or tension only contact type problems.

  11. Probabilistic Mobility Models for Mobile and Wireless Networks

    DEFF Research Database (Denmark)

    Song, Lei; Godskesen, Jens Christian

    2010-01-01

    In this paper we present a probabilistic broadcast calculus for mobile and wireless networks whose connections are unreliable. In our calculus broadcasted messages can be lost with a certain probability, and due to mobility the connection probabilities may change. If a network broadcasts a message....... It is possible to have weak bisimular networks which have different probabilistic connectivity information. We also examine the relation between our weak bisimulation and a minor variant of PCTL*. Finally we apply our calculus on a small example called the ZeroConf protocol....

  12. Probabilistic Mobility Models for Mobile and Wireless Networks

    DEFF Research Database (Denmark)

    Song, Lei; Godskesen, Jens Christian

    2010-01-01

    In this paper we present a probabilistic broadcast calculus for mobile and wireless networks whose connections are unreliable. In our calculus broadcasted messages can be lost with a certain probability, and due to mobility the connection probabilities may change. If a network broadcasts a message....... It is possible to have weak bisimular networks which have different probabilistic connectivity information. We also examine the relation between our weak bisimulation and a minor variant of PCTL*. Finally we apply our calculus on a small example called the ZeroConf protocol....

  13. A transitions model for sustainable mobility

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, Jonathan [Fraunhofer-Institut fuer System- und Innovationsforschung ISI (Germany); Whitmarsh, Lorraine; Haxeltine, Alex [Tyndall Centre for Climate Change Research, ZICER, School of Environmental Sciences, University of East Anglia, Norwich, Norfolk, NR4 7TJ (United Kingdom); Nykvist, Bjoern [Stockholm Environment Institute, Kraeftriket 2B, SE-106 91 Stockholm (Sweden); Schilperoord, Michel [UCD Innovation Research Unit (IRU), Complex Adaptive Systems Laboratory CASL, University College Dublin 8 Belfield Office Park, Beaver Row, Clonskeagh, Dublin 4 (Ireland); Bergman, Noam [Environmental Change Institute, Oxford University Centre for the Environment, South Parks Road, Oxford, OX1 3QY (United Kingdom)

    2009-10-15

    This paper reports on the development of a model for assessing transitions to sustainable mobility. The model uses the concepts of transition theory as a framework for assessing possible pathways by which a transition to a sustainable mobility society might happen. The modelling approach combines agent-based modelling techniques with a system dynamics structure. It is original in that there are two levels of agent. There are a small number of complex agents, which have an internal structure and are therefore subsystems within society, and a larger number of simple agents. Based on the UK data, the results show that Hydrogen Fuel Cell Vehicles (FCVs) come to dominate, but only in the very long run (after 2030), while biofuels and ICE (Internal Combustion Engine)-electric hybrids are the main alternatives to the regime in the next 10-30 years, because a) they are already developed and b) they fit better into current infrastructures. The model shows that technological transitions are most likely. Lifestyle change transitions require sustained pressure from the environment on society and behavioural change from consumers. (author)

  14. Discrete Element Modeling for Mobility and Excavation

    Science.gov (United States)

    Knuth, M. A.; Hopkins, M. A.

    2011-12-01

    The planning and completion of mobility and excavation efforts on the moon requires a thorough understanding of the planetary regolith. In this work, a discrete element method (DEM) model is created to replicate those activities in the laboratory and for planning mission activities in the future. The crux of this work is developing a particle bed that best replicates the regolith tool/wheel interaction seen in the laboratory. To do this, a DEM geotechnical triaxial strength cell was created allowing for comparison of laboratory JSC-1a triaxial tests to DEM simulated soils. This model relies on a triangular lattice membrane covered triaxial cell for determining the macroscopic properties of the modeled granular material as well as a fast and efficient contact detection algorithm for a variety of grain shapes. Multiple grain shapes with increasing complexity (ellipsoid, poly-ellipsoid and polyhedra) have been developed and tested. This comparison gives us a basis to begin scaling DEM grain size and shape to practical values for mobility and excavation modeling. Next steps include development of a DEM scoop for percussive excavation testing as well as continued analysis of rover wheel interactions using a wide assortment of grain shape and size distributions.

  15. Distributional Analysis for Model Predictive Deferrable Load Control

    OpenAIRE

    Chen, Niangjun; Gan, Lingwen; Low, Steven H.; Wierman, Adam

    2014-01-01

    Deferrable load control is essential for handling the uncertainties associated with the increasing penetration of renewable generation. Model predictive control has emerged as an effective approach for deferrable load control, and has received considerable attention. In particular, previous work has analyzed the average-case performance of model predictive deferrable load control. However, to this point, distributional analysis of model predictive deferrable load control has been elusive. In ...

  16. Catastrophe model and its experimental verification of static loading rock system under impact load

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    According to the catastrophe model for impact buckling of static loading structures, a new catastrophe model for impact loading failure of a static loading rock system was established, and one dimension (1D) catastrophe model was analyzed. The analysis results indicate that the furcation collection where catastrophe may take place is not only decided by mechanical system itself but also relates to exterior loading, which is different from the results obtained under mono-static loading where the bifurcation collection is only determined by mechanics of the system itself and has nothing to do with exterior loading. In addition, the corresponding 1D coupled static-dynamic loading experiment is designed to verify the analysis results of catastrophe model The test is done with Instron 1342 electroservo controlled testing system, in which medium strain rate is caused by monotony rising dynamic load. The parameters are obtained combining theoretical model with experiment. The experimental and theoretical curves of critical dynamic load vs static load are rather coincided, thus the new model is proved to be correct.

  17. A Swarm Intelligence Based Model for Mobile Cloud Computing

    Directory of Open Access Journals (Sweden)

    Ahmed S. Salama

    2015-01-01

    Full Text Available Mobile Computing (MC provides multi services and a lot of advantages for millions of users across the world over the internet. Millions of business customers have leveraged cloud computing services through mobile devices to get what is called Mobile Cloud Computing (MCC. MCC aims at using cloud computing techniques for storage and processing of data on mobile devices, thereby reducing their limitations. This paper proposes architecture for a Swarm Intelligence Based Mobile Cloud Computing Model (SIBMCCM. A model that uses a proposed Parallel Particle Swarm Optimization (PPSO algorithm to enhance the access time for the mobile cloud computing services which support different E Commerce models and to better secure the communication through the mobile cloud and the mobile commerce transactions.

  18. Performance Evaluation of Two Reactive Routing Protocols of MANET using Group Mobility Model

    Directory of Open Access Journals (Sweden)

    Harminder S. Bindra

    2010-05-01

    Full Text Available Mobile ad-hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any stand-alone infrastructure or centralized administration. Mobile ad-hoc network have the attributes such as wireless connection, continuously changing topology, distributed operation and ease of deployment. In this paper we have compared the performance of two reactive MANET routing protocol AODV and DSR by using Group mobility model. Both share similar On-Demand behavior, but the protocol's internal mechanism leads to significant performance difference. We have analyzed the performance of protocols by varying network load, mobility and type of traffic (CBR and TCP. Group Mobility model has been generated by IMPORTANT (Impact of Mobility Patterns on Routing in Ad-hoc NeTwork tool. A detailed simulation has been carried out in NS2. The metrics used for performance analysis are Packet Delivery Fraction, Average end-to-end Delay, Routing Overhead and Normalized Routing Load. It has been observed that AODV gives better performance in CBR traffic and real time delivery of packet. Where as DSR gives better results in TCP traffic and under restricted bandwidth condition.

  19. Performance Analysis of MANET Routing Protocols in Different Mobility Models

    Directory of Open Access Journals (Sweden)

    Anuj K. Gupta

    2013-05-01

    Full Text Available A mobile ad-hoc network (MANET is basically called as a network without any central administration or fixed infrastructure. It consists of a number of mobile nodes that use to send data packets through a wireless medium. There is always a need of a good routing protocol in order to establish the connection between mobile nodes since they possess the property of dynamic changing topology. Further, in all the existing routing protocols, mobility of a node has always been one of the important characteristics in determining the overall performance of the ad hoc network. Thus, it is essential to know about various mobility models and their effect on the routing protocols. In this paper, we have made an attempt to compare different mobility models and provide an overview of their current research status. The main focus is on Random Mobility Models and Group Mobility Models. Firstly, we present a survey of the characteristics, drawbacks and research challenges of mobility modeling. At the last we present simulation results that illustrate the importance of choosing a mobility model in the simulation of an ad hoc network protocol. Also, we illustrate how the performance results of an ad hoc network protocol drastically change as a result of changing the mobility model simulated.

  20. Mobile news - a review and model of journalism in an age of mobile media

    DEFF Research Database (Denmark)

    Westlund, Oscar

    2012-01-01

    . This article explores the production of mobile news, by discussing and synthesising the findings of the contemporary literature found in the nexus of journalism and mobile media. It posits a model of journalism focusing on the roles of humans and technology in activities characterised by customising......The technological convergence of mobile “phones” and multimedia has been taking place since the 1990s, but it was not until the commercial birth of touchscreen-enabled mobile devices, offered with flat-rate subscriptions for mobile internet, that widespread production and use of news......-related content and services began to flourish. Accessing mobile news has gained traction in the everyday life of the public. In parallel, legacy news media have in recent years developed news provision, by repurposing or customising journalistic content published for mobile sites and/or applications...

  1. The Mobile Robot HILARE: Dynamic Modeling and Motion Simulation

    OpenAIRE

    M. Ghazal; A. Talezadeh; Taheri, M.; M. Nazemi-Zade

    2014-01-01

    To perform mission in variant environment, several types of mobile robot has been developed an implemented. The mobile robot HILARE is a known wheeled mobile robot which has two fixed wheels and an off-entered orientable wheel. Due to extended application of this robot, its dynamic analysis has attracted a great deal of interests. This article investigates dynamic modeling and motion analysis of the mobile robot HILARE. As the wheels of the robot have kinematic constraints, the constraints of...

  2. Multivariate Modelling of Extreme Load Combinations for Wind Turbines

    DEFF Research Database (Denmark)

    Dimitrov, Nikolay Krasimirov

    2015-01-01

    We demonstrate a model for estimating the joint probability distribution of two load components acting on a wind turbine blade cross section. The model addresses the problem of modelling the probability distribution of load time histories with large periodic components by dividing the signal...... into a periodic part and a perturbation term, where each part has a known probability distribution. The proposed model shows good agreement with simulated data under stationary conditions, and a design load envelope based on this model is comparable to the load envelope estimated using the standard procedure...... for determining contemporaneous loads. By defining a joint probability distribution and full return-period contours for multiple load components, the suggested procedure gives the possibility for determining the most critical loading direction in a blade cross section, or for carrying out reliability analysis...

  3. Bed load tracer mobility in a mixed bedrock/alluvial channel

    Science.gov (United States)

    Ferguson, R. I.; Sharma, B. P.; Hodge, R. A.; Hardy, R. J.; Warburton, J.

    2017-04-01

    The presence of bare or partially covered rock in an otherwise alluvial river implies a downstream change in transport capacity relative to supply. Field investigations of this change and what causes it are lacking. We used two sets of magnet-tagged tracer clasts to investigate bed load transport during the same sequence of floods in fully alluvial, bare rock, and partial-cover reaches of an upland stream. High-flow shear stresses in different reaches were calculated by using stage loggers. Tracers seeded in the upstream alluvial channel moved more slowly than elsewhere until the frontrunners reached bare rock and sped up. Tracers seeded on bare rock moved rapidly off it and accumulated just upstream from, and later in, a partial-cover zone with many boulders. The backwater effect of the boulder-rich zone is significant in reducing tracer mobility. Tracer movement over full or partial sediment cover was size selective but dispersion over bare rock was not. Along-channel changes in tracer mobility are interpreted in terms of measured differences in shear stress and estimated differences in threshold stress.

  4. Autonomous Coordination and Online Motion Modeling for Mobile Robots

    Science.gov (United States)

    2007-09-01

    COORDINATION AND ONLINE MOTION MODELING FOR MOBILE ROBOTS by Eric Sjoberg September 2007 Co-Advisors: Kevin Squire Craig Martell...AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE Autonomous Coordination and Online Motion Modeling for Mobile Robots 6. AUTHOR Eric J...unlimited AUTONOMOUS COORDINATION AND ONLINE MOTION MODELING FOR MOBILE ROBOTS Eric J. Sjoberg Captain, United States Marine Corps B.S

  5. A Brownian Bridge Movement Model to Track Mobile Targets

    Science.gov (United States)

    2016-09-01

    BRIDGE MOVEMENT MODEL TO TRACK MOBILE TARGETS by Chun Chieh Cheng September 2016 Thesis Advisor: Dashi I. Singham Second Reader: Michael P...DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE A BROWNIAN BRIDGE MOVEMENT MODEL TO TRACK MOBILE TARGETS 5. FUNDING NUMBERS 6. AUTHOR(S...Approved for public release. Distribution is unlimited. A BROWNIAN BRIDGE MOVEMENT MODEL TO TRACK MOBILE TARGETS Chun Chieh Cheng Major

  6. Rapid world modelling from a mobile platform

    Energy Technology Data Exchange (ETDEWEB)

    Barry, R.E.; Jones, J.P. [Oak Ridge National Lab., TN (United States); Little, C.Q. [Sandia National Labs., Albuquerque, NM (United States); Wilson, C.W.

    1997-04-01

    The ability to successfully use and interact with a computerized world model is dependent on the ability to create an accurate world model. The goal of this project was to develop a prototype system to remotely deploy sensors into a workspace, collect surface information, and rapidly build an accurate world model of that workspace. A key consideration was that the workspace areas are typically hazardous environments, where it is difficult or impossible for humans to enter. Therefore, the system needed to be fully remote, with no external connections. To accomplish this goal, an electric, mobile platform with battery power sufficient for both the platform and sensor electronics was procured and 3D range sensors were deployed on the platform to capture surface data within the workspace. A radio Ethernet connection was used to provide communications to the vehicle and all on-board electronics. Video from on-board cameras was also transmitted to the base station and used to teleoperate the vehicle. Range data generated by the on-board 3D sensors was transformed into surface maps, or models. Registering the sensor location to a consistent reference frame as the platform moved through the workspace allowed construction of a detailed 3D world model of the extended workspace.

  7. Mobile Cloud Computing: A Comparison of Application Models

    CERN Document Server

    Kovachev, Dejan; Klamma, Ralf

    2011-01-01

    Cloud computing is an emerging concept combining many fields of computing. The foundation of cloud computing is the delivery of services, software and processing capacity over the Internet, reducing cost, increasing storage, automating systems, decoupling of service delivery from underlying technology, and providing flexibility and mobility of information. However, the actual realization of these benefits is far from being achieved for mobile applications and open many new research questions. In order to better understand how to facilitate the building of mobile cloud-based applications, we have surveyed existing work in mobile computing through the prism of cloud computing principles. We give a definition of mobile cloud coputing and provide an overview of the results from this review, in particular, models of mobile cloud applications. We also highlight research challenges in the area of mobile cloud computing. We conclude with recommendations for how this better understanding of mobile cloud computing can ...

  8. A PROPOSED HYBRID AGILE FRAMEWORK MODEL FOR MOBILE APPLICATIONS DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Ammar Khader Almasri

    2016-03-01

    Full Text Available With the increasing in mobile application systems and a high competition between companies, that led to increase in the number of mobile application projects. Mobile software development is a group of process for creating software for mobile devices with limited resources like small screen, low-power. The development of mobile applications is a big challenging because of rapidly changing business requirements and technical constraints for mobile systems. So, developers faced the challenge of a dynamic environment and the Changing of mobile application requirements. Moreover, Mobile applications should adapt appropriate software development methods that act in response efficiently to these challenges. However, at the moment, there is limited knowledge about the suitability of different software practices for the development of mobile applications. According to many researchers ,Agile methodologies was found to be most suitable for mobile development projects as they are short time, require flexibility, reduces waste and time to market. Finally, in this research we are looking for a suitable process model that conforms to the requirement of mobile application, we are going to investigate agile development methods to find a way, making the development of mobile application easy and compatible with mobile device features.

  9. EXAMINING THE MOVEMENTS OF MOBILE NODES IN THE REAL WORLD TO PRODUCE ACCURATE MOBILITY MODELS

    Directory of Open Access Journals (Sweden)

    TANWEER ALAM

    2010-09-01

    Full Text Available All communication occurs through a wireless median in an ad hoc network. Ad hoc networks are dynamically created and maintained by the individual nodes comprising the network. Random Waypoint Mobility Model is a model that includes pause times between changes in destination and speed. To produce a real-world environment within which an ad hoc network can be formed among a set of nodes, there is a need for the development of realistic, generic and comprehensive mobility models. In this paper, we examine the movements of entities in the real world and present the production of mobility model in an ad hoc network.

  10. Mobile Laser Scanning for Indoor Modelling

    Science.gov (United States)

    Thomson, C.; Apostolopoulos, G.; Backes, D.; Boehm, J.

    2013-10-01

    The process of capturing and modelling buildings has gained increased focus in recent years with the rise of Building Information Modelling (BIM). At the heart of BIM is a process change for the construction and facilities management industries whereby a BIM aids more collaborative working through better information exchange, and as a part of the process Geomatic/Land Surveyors are not immune from the changes. Terrestrial laser scanning has been proscribed as the preferred method for rapidly capturing buildings for BIM geometry. This is a process change from a traditional measured building survey just with a total station and is aided by the increasing acceptance of point cloud data being integrated with parametric building models in BIM tools such as Autodesk Revit or Bentley Architecture. Pilot projects carried out previously by the authors to investigate the geometry capture and modelling of BIM confirmed the view of others that the process of data capture with static laser scan setups is slow and very involved requiring at least two people for efficiency. Indoor Mobile Mapping Systems (IMMS) present a possible solution to these issues especially in time saved. Therefore this paper investigates their application as a capture device for BIM geometry creation over traditional static methods through a fit-for-purpose test.

  11. Power System Aggregate Load Area Modelling by Particle Swarm Optimization

    Institute of Scientific and Technical Information of China (English)

    Jian-Lin Wei; Ji-Hong Wang; Q.H.Wu; Nan Lu

    2005-01-01

    This paper presents a new approach for deriving a power system aggregate load area model (ALAM). In this approach, an equivalent area load model is derived to represent the load characters for a particular area load of a power system network. The Particle Swarm Optimization (PSO) method is employed to identify the unknown parameters of the generalised system, ALAM, based on the system measurement directly using a one-step scheme. Simulation studies are carried out for an IEEE 14-Bus power system and an IEEE 57-Bus power system. Simulation results show that the ALAM can represent the area load characters accurately under different operational conditions and at different power system states.

  12. Flying Ad-Hoc Networks: Routing Protocols, Mobility Models, Issues

    Directory of Open Access Journals (Sweden)

    Muneer Bani Yassein

    2016-06-01

    Full Text Available Flying Ad-Hoc Networks (FANETs is a group of Unmanned Air Vehicles (UAVs which completed their work without human intervention. There are some problems in this kind of networks: the first one is the communication between (UAVs. Various routing protocols introduced classified into three categories, static, proactive, reactive routing protocols in order to solve this problem. The second problem is the network design, which depends on the network mobility, in which is the process of cooperation and collaboration between the UAV. Mobility model of FANET is introduced in order to solve this problem. In Mobility Model, the path and speed variations of the UAV and represents their position are defined. As of today, Random Way Point Model is utilized as manufactured one for Mobility in the greater part of recreation situations. The Arbitrary Way Point model is not relevant for the UAV in light of the fact that UAV do not alter their course and versatility, speed quickly at one time because of this reason, we consider more practical models, called Semi-Random Circular Movement (SRCM Mobility Model. Also, we consider different portability models, Mission Plan-Based (MPB Mobility Model, Pheromone-Based Model. Moreover, Paparazzi Mobility Model (PPRZM. This paper presented and discussed the main routing protocols and main mobility models used to solve the communication, cooperation, and collaboration in FANET networks.

  13. Mobile news - a review and model of journalism in an age of mobile media

    DEFF Research Database (Denmark)

    Westlund, Oscar

    2012-01-01

    . This article explores the production of mobile news, by discussing and synthesising the findings of the contemporary literature found in the nexus of journalism and mobile media. It posits a model of journalism focusing on the roles of humans and technology in activities characterised by customising...

  14. Realistic Mobility Modeling for Vehicular Ad Hoc Networks

    Science.gov (United States)

    Akay, Hilal; Tugcu, Tuna

    2009-08-01

    Simulations used for evaluating the performance of routing protocols for Vehicular Ad Hoc Networks (VANET) are mostly based on random mobility and fail to consider individual behaviors of the vehicles. Unrealistic assumptions about mobility produce misleading results about the behavior of routing protocols in real deployments. In this paper, a realistic mobility modeling tool, Mobility for Vehicles (MOVE), which considers the basic mobility behaviors of vehicles, is proposed for a more accurate evaluation. The proposed model is tested against the Random Waypoint (RWP) model using AODV and OLSR protocols. The results show that the mobility model significantly affects the number of nodes within the transmission range of a node, the volume of control traffic, and the number of collisions. It is shown that number of intersections, grid size, and node density are important parameters when dealing with VANET performance.

  15. Risk Assessment Model for Mobile Malware

    OpenAIRE

    George Stanescu

    2015-01-01

    The mobile technology is considered to be the fastest-developing IT security area. Only in the last year security threats around mobile devices have reached new heights in terms of both quality and quantity. The speed of this development has made possible several types of security attacks that, until recently, were only possible on computers. In terms of the most targeted mobile operating systems, Android continues to be the most vulnerable, although new ways of strengthening its security mod...

  16. Modeling Terrain Impact on Mobile Ad Hoc Networks (MANET) Connectivity

    Science.gov (United States)

    2014-05-01

    Modeling Terrain Impact on Mobile Ad Hoc Networks ( MANET ) Connectivity Lance Joneckis Corinne Kramer David Sparrow David Tate I N S T I T U T E F...SUBTITLE Modeling Terrain Impact on Mobile Ad Hoc Networks ( MANET ) Connectivity 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...1882 ljonecki@ida.org Abstract—Terrain affects connectivity in mobile ad hoc net- works ( MANET ). Both average pairwise link closure and the rate

  17. The Pattern as a Reusable Component to Adaptive Framework for Load Balancing Mobile Agent in Internet Banking

    Directory of Open Access Journals (Sweden)

    A. Meiappane

    2012-03-01

    Full Text Available In recent years, the Software Architecture (SA of an Internet banking has become one of the most challengeable and risky fields of modern technology. The advent of the Internet has revolutionized the way banking is being done. In Internet banking, we analyzed some attributes such as usage, security, availability, load balancing and so on. Among those attributes Load Balancing is a serious problem in the Internet and it is necessary to build new systems incorporating load balancing as integral part of their design. The use of patterns, which is of a reusable component, is a good tool to help designers build load balancing systems. In this paper we are going to propose cluster load balancing technique by using mobile agent.

  18. Modeling of Closed-Die Forging for Estimating Forging Load

    Science.gov (United States)

    Sheth, Debashish; Das, Santanu; Chatterjee, Avik; Bhattacharya, Anirban

    2017-02-01

    Closed die forging is one common metal forming process used for making a range of products. Enough load is to exert on the billet for deforming the material. This forging load is dependent on work material property and frictional characteristics of the work material with the punch and die. Several researchers worked on estimation of forging load for specific products under different process variables. Experimental data on deformation resistance and friction were used to calculate the load. In this work, theoretical estimation of forging load is made to compare this value with that obtained through LS-DYNA model facilitating the finite element analysis. Theoretical work uses slab method to assess forging load for an axi-symmetric upsetting job made of lead. Theoretical forging load estimate shows slightly higher value than the experimental one; however, simulation shows quite close matching with experimental forging load, indicating possibility of wide use of this simulation software.

  19. Software Reuse of Mobile Systems based on Modelling

    Directory of Open Access Journals (Sweden)

    Guo Ping

    2016-01-01

    Full Text Available This paper presents an architectural style based modelling approach for architectural design, analysis of mobile systems. The approach is developed based on UML-like meta models and graph transformation techniques to support sound methodological principals, formal analysis and refinement. The approach could support mobile system development.

  20. Community Mobilization Model Applied to Support Grandparents Raising Grandchildren

    Science.gov (United States)

    Miller, Jacque; Bruce, Ann; Bundy-Fazioli, Kimberly; Fruhauf, Christine A.

    2010-01-01

    This article discusses the application of a community mobilization model through a case study of one community's response to address the needs of grandparents raising grandchildren. The community mobilization model presented is one that is replicable in addressing diverse community identified issues. Discussed is the building of the partnerships,…

  1. Optimization of the computational load of a hypercube supercomputer onboard a mobile robot

    Energy Technology Data Exchange (ETDEWEB)

    Barhen, J.; Toomarian, N.; Protopopescu, V.

    1987-12-01

    A combinatorial optimization methodology is developed, which enables the efficient use of hypercube multiprocessors onboard mobile intelligent robots dedicated to time-critical missions. The methodology is implemented in terms of large-scale concurrent algorithms based either on fast simulated annealing, or on nonlinear asynchronous neural networks. In particular, analytic expressions are given for the effect of single-neuron perturbations on the systems' configuration energy. Compact neuromorphic data structures are used to model effects such as precedence constraints, processor idling times, and task-schedule overlaps. Results for a typical robot-dynamics benchmark are presented.

  2. Data Modeling for Mobile Services in the Real World

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Pedersen, Torben Bach; Speicys, L.

    2003-01-01

    . In contrast, this paper describes holistic concepts and techniques for mobile data modeling that are readily applicable in practice. Focus is on services to be delivered to mobile users, such as route guidance, point-of-interest search, road pricing, parking payment, traffic monitoring, etc. While geo......Research contributions on data modeling, data structures, query processing, and indexing for mobile services may have an impact in the longer term, but each contribution typically offers an isolated solution to one small part of the practical problem of delivering mobile services in the real world...

  3. Stochastic Characteristics and Simulation of the Random Waypoint Mobility Model

    CERN Document Server

    Ahuja, A; Krishna, P Venkata

    2012-01-01

    Simulation results for Mobile Ad-Hoc Networks (MANETs) are fundamentally governed by the underlying Mobility Model. Thus it is imperative to find whether events functionally dependent on the mobility model 'converge' to well defined functions or constants. This shall ensure the long-run consistency among simulation performed by disparate parties. This paper reviews a work on the discrete Random Waypoint Mobility Model (RWMM), addressing its long run stochastic stability. It is proved that each model in the targeted discrete class of the RWMM satisfies Birkhoff's pointwise ergodic theorem [13], and hence time averaged functions on the mobility model surely converge. We also simulate the most common and general version of the RWMM to give insight into its working.

  4. Towards Modeling Realistic Mobility for Performance Evaluations in MANET

    Science.gov (United States)

    Aravind, Alex; Tahir, Hassan

    Simulation modeling plays crucial role in conducting research on complex dynamic systems like mobile ad hoc networks and often the only way. Simulation has been successfully applied in MANET for more than two decades. In several recent studies, it is observed that the credibility of the simulation results in the field has decreased while the use of simulation has steadily increased. Part of this credibility crisis has been attributed to the simulation of mobility of the nodes in the system. Mobility has such a fundamental influence on the behavior and performance of mobile ad hoc networks. Accurate modeling and knowledge of mobility of the nodes in the system is not only helpful but also essential for the understanding and interpretation of the performance of the system under study. Several ideas, mostly in isolation, have been proposed in the literature to infuse realism in the mobility of nodes. In this paper, we attempt a holistic analysis of creating realistic mobility models and then demonstrate creation and analysis of realistic mobility models using a software tool we have developed. Using our software tool, desired mobility of the nodes in the system can be specified, generated, analyzed, and then the trace can be exported to be used in the performance studies of proposed algorithms or systems.

  5. A Fusion Model for CPU Load Prediction in Cloud Computing

    Directory of Open Access Journals (Sweden)

    Dayu Xu

    2013-11-01

    Full Text Available Load prediction plays a key role in cost-optimal resource allocation and datacenter energy saving. In this paper, we use real-world traces from Cloud platform and propose a fusion model to forecast the future CPU loads. First, long CPU load time series data are divided into short sequences with same length from the historical data on the basis of cloud control cycle. Then we use kernel fuzzy c-means clustering algorithm to put the subsequences into different clusters. For each cluster, with current load sequence, a genetic algorithm optimized wavelet Elman neural network prediction model is exploited to predict the CPU load in next time interval. Finally, we obtain the optimal cloud computing CPU load prediction results from the cluster and its corresponding predictor with minimum forecasting error. Experimental results show that our algorithm performs better than other models reported in previous works.

  6. Modelling Social Mobility in Rural Tamil Nadu

    OpenAIRE

    Djurfeldt, Göran; Athreya, Venkatesh B.; N.JAYAKUMAR; Lindberg, Staffan; Rajagopal, A; Vidyasagar, R.

    2007-01-01

    This is a study of social mobility over 25 years in six villages in the former Tiruchy District in Tamil Nadu. The two most important external drivers are local industrialization and social policy in a broad sense. Analyzing mobility matrices by means of regression techniques, it is shown that the overall effect is a centripetal tendency in agrarian structure, with tendencies towards a strengthened position for family farming and for both the topdogs and the underdogs in the old agrarian soci...

  7. Popularity Modeling for Mobile Apps: A Sequential Approach.

    Science.gov (United States)

    Zhu, Hengshu; Liu, Chuanren; Ge, Yong; Xiong, Hui; Chen, Enhong

    2015-07-01

    The popularity information in App stores, such as chart rankings, user ratings, and user reviews, provides an unprecedented opportunity to understand user experiences with mobile Apps, learn the process of adoption of mobile Apps, and thus enables better mobile App services. While the importance of popularity information is well recognized in the literature, the use of the popularity information for mobile App services is still fragmented and under-explored. To this end, in this paper, we propose a sequential approach based on hidden Markov model (HMM) for modeling the popularity information of mobile Apps toward mobile App services. Specifically, we first propose a popularity based HMM (PHMM) to model the sequences of the heterogeneous popularity observations of mobile Apps. Then, we introduce a bipartite based method to precluster the popularity observations. This can help to learn the parameters and initial values of the PHMM efficiently. Furthermore, we demonstrate that the PHMM is a general model and can be applicable for various mobile App services, such as trend based App recommendation, rating and review spam detection, and ranking fraud detection. Finally, we validate our approach on two real-world data sets collected from the Apple Appstore. Experimental results clearly validate both the effectiveness and efficiency of the proposed popularity modeling approach.

  8. MODEL-BASED PERFORMANCE EVALUATION APPROACH FOR MOBILE AGENT SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Li Xin; Mi Zhengkun; Meng Xudong

    2004-01-01

    Claimed as the next generation programming paradigm, mobile agent technology has attracted extensive interests in recent years. However, up to now, limited research efforts have been devoted to the performance study of mobile agent system and most of these researches focus on agent behavior analysis resulting in that models are hard to apply to mobile agent systems. To bridge the gap, a new performance evaluation model derived from operation mechanisms of mobile agent platforms is proposed. Details are discussed for the design of companion simulation software, which can provide the system performance such as response time of platform to mobile agent. Further investigation is followed on the determination of model parameters. Finally comparison is made between the model-based simulation results and measurement-based real performance of mobile agent systems. The results show that the proposed model and designed software are effective in evaluating performance characteristics of mobile agent systems. The proposed approach can also be considered as the basis of performance analysis for large systems composed of multiple mobile agent platforms.

  9. A LOAD BALANCING MODEL USING FIREFLY ALGORITHM IN CLOUD COMPUTING

    Directory of Open Access Journals (Sweden)

    A. Paulin Florence

    2014-01-01

    Full Text Available Cloud computing is a model that points at streamlining the on-demand provisioning of software, hardware and data as services and providing end-users with flexible and scalable services accessible through the Internet. The main objective of the proposed approach is to maximize the resource utilization and provide a good balanced load among all the resources in cloud servers. Initially, a load model of every resource will be derived based on several factors such as, memory usage, processing time and access rate. Based on the newly derived load index, the current load will be computed for all the resources shared in virtual machine of cloud servers. Once the load index is computed for all the resources, load balancing operation will be initiated to effectively use the resources dynamically with the process of assigning resources to the corresponding node to reduce the load value. So, assigning of resources to proper nodes is an optimal distribution problem so that many optimization algorithms such as genetic algorithm and modified genetic algorithm are utilized for load balancing. These algorithms are not much effective in providing the neighbour solutions since it does not overcome exploration and exploration problem. So, utilizing the effective optimization procedure instead of genetic algorithm can lead to better load balancing since it is a traditional and old algorithm. Accordingly, I have planned to utilize a recent optimization algorithm, called firefly algorithm to do the load balancing operation in our proposed work. At first, the index table will be maintained by considering the availability of virtual servers and sequence of request. Then, load index will be computed based on the newly derived formulae. Based on load index, load balancing operation will be carried out using firefly algorithm. The performance analysis produced expected results and thus proved the proposed approach is efficient in optimizing schedules by balancing the

  10. A multibody modelling approach to determine load sharing between passive elements of the lumbar spine.

    Science.gov (United States)

    Abouhossein, Alireza; Weisse, Bernhard; Ferguson, Stephen J

    2011-06-01

    The human spinal segment is an inherently complex structure, a combination of flexible and semi-rigid articulating elements stabilised by seven principal ligaments. An understanding of how mechanical loading is shared among these passive elements of the segment is required to estimate tissue failure stresses. A 3D rigid body model of the complete lumbar spine has been developed to facilitate the prediction of load sharing across the passive elements. In contrast to previous multibody models, this model includes a non-linear, six degrees of freedom intervertebral disc, facet bony articulations and all spinal ligaments. Predictions of segmental kinematics and facet joint forces, in response to pure moment loading (flexion-extension), were compared to published in vitro data. On inclusion of detailed representation of the disc and facets, the multibody model fully captures the non-linear flexibility response of the spinal segment, i.e. coupled motions and a mobile instantaneous centre of rotation. Predicted facet joint forces corresponded well with reported values. For the loading case considered, the model predicted that the ligaments are the main stabilising elements within the physiological motion range; however, the disc resists a greater proportion of the applied load as the spine is fully flexed. In extension, the facets and capsular ligaments provide the principal resistance. Overall patterns of load distribution to the spinal ligaments are in agreement with previous predictions; however, the current model highlights the important role of the intraspinous ligament in flexion and the potentially high risk of failure. Several important refinements to the multibody modelling of the passive elements of the spine have been described, and such an enhanced passive model can be easily integrated into a full musculoskeletal model for the prediction of spinal loading for a variety of daily activities.

  11. Traversable Terrain Modeling and Performance Measurement of Mobile Robots

    Science.gov (United States)

    2004-08-01

    In this paper, we have described a technique for terrain traversability assessment modeling of mobile robots operating in natural terrain and...presented a fast near-optimum algorithm for autonomous navigational path planning of mobile robots in rough terrain environments. The proposed method is

  12. Dynamic Pathloss Model for Future Mobile Communication Networks

    DEFF Research Database (Denmark)

    Kumar, Ambuj; Mihovska, Albena Dimitrova; Prasad, Ramjee

    2016-01-01

    — Future mobile communication networks (MCNs) are expected to be more intelligent and proactive based on new capabilities that increase agility and performance. However, for any successful mobile network service, the dexterity in network deployment is a key factor. The efficiency of the network...... that incorporates the environmental dynamics factor in the propagation model for intelligent and proactively iterative networks...

  13. A Top-Down Spatially Resolved Electrical Load Model

    Directory of Open Access Journals (Sweden)

    Martin Robinius

    2017-03-01

    Full Text Available The increasing deployment of variable renewable energy sources (VRES is changing the source regime in the electrical energy sector. However, VRES feed-in from wind turbines and photovoltaic systems is dependent on the weather and only partially predictable. As a result, existing energy sector models must be re-evaluated and adjusted as necessary. In long-term forecast models, the expansion of VRES must be taken into account so that future local overloads can be identified and measures taken. This paper focuses on one input factor for electrical energy models: the electrical load. We compare two different types to describe this, namely vertical grid load and total load. For the total load, an approach for a spatially-resolved electrical load model is developed and applied at the municipal level in Germany. This model provides detailed information about the load at a quarterly-hour resolution across 11,268 German municipalities. In municipalities with concentrations of energy-intensive industry, high loads are expected, which our simulation reproduces with a good degree of accuracy. Our results also show that municipalities with energy-intensive industry have a higher simulated electric load than neighboring municipalities that do not host energy-intensive industries. The underlying data was extracted from publically accessible sources and therefore the methodology introduced is also applicable to other countries.

  14. Small World Model-Based Polylogarithmic Routing Using Mobile Nodes

    Institute of Scientific and Technical Information of China (English)

    Jie Wu; Shu-Hui Yang

    2008-01-01

    The use of mobile nodes to improve network system performance has drawn considerable attention recently.The movement-assisted model considers mobility as a desirable feature, where routing is based on the store-carry-forward paradigm with random or controlled movement of resource rich mobile nodes. The application of such a model has been used in several emerging networks, including mobile ad hoc networks (MANETs), wireless sensor networks (WSNs), and delay tolerant networks (DTNs). It is well known that mobility increases the capacity of MANETs by reducing the number of relays for routing, prolonging the lifespan of WSNs by using mobile nodes in place of bottleneck static sensors, and ensuring network connectivity in DTNs using mobile nodes to connect different parts of a disconnected network. Trajectory planning and the coordination of mobile nodes are two important design issues aiming to optimize or balance several measures,including delay, average number of relays, and moving distance. In this paper, we propose a new controlled mobility model with an expected polylogarithmic number of relays to achieve a good balance among several contradictory goals, including delay, the number of relays, and moving distance. The model is based on the small-world model where each static node has "short" link connections to its nearest neighbors and "long" link connections to other nodes following a certain probability distribution. Short links are regular wireless connections whereas long links are implemented using mobile nodes. Various issues are considered, including trade-offs between delay and average number of relays, selection of the number of mobilenodes, and selection of the number of long links. The effectiveness of the proposed model is evaluated analytically as well as through simulation.

  15. Safe motion planning for mobile agents: A model of reactive planning for multiple mobile agents

    Energy Technology Data Exchange (ETDEWEB)

    Fujimura, Kikuo.

    1990-01-01

    The problem of motion planning for multiple mobile agents is studied. Each planning agent independently plans its own action based on its map which contains a limited information about the environment. In an environment where more than one mobile agent interacts, the motions of the robots are uncertain and dynamic. A model for reactive agents is described and simulation results are presented to show their behavior patterns. 18 refs., 2 figs.

  16. Modeling the propagation of mobile phone virus under complex network.

    Science.gov (United States)

    Yang, Wei; Wei, Xi-liang; Guo, Hao; An, Gang; Guo, Lei; Yao, Yu

    2014-01-01

    Mobile phone virus is a rogue program written to propagate from one phone to another, which can take control of a mobile device by exploiting its vulnerabilities. In this paper the propagation model of mobile phone virus is tackled to understand how particular factors can affect its propagation and design effective containment strategies to suppress mobile phone virus. Two different propagation models of mobile phone viruses under the complex network are proposed in this paper. One is intended to describe the propagation of user-tricking virus, and the other is to describe the propagation of the vulnerability-exploiting virus. Based on the traditional epidemic models, the characteristics of mobile phone viruses and the network topology structure are incorporated into our models. A detailed analysis is conducted to analyze the propagation models. Through analysis, the stable infection-free equilibrium point and the stability condition are derived. Finally, considering the network topology, the numerical and simulation experiments are carried out. Results indicate that both models are correct and suitable for describing the spread of two different mobile phone viruses, respectively.

  17. Load Composition Model Workflow (BPA TIP-371 Deliverable 1A)

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Cezar, Gustavo V.; /SLAC

    2017-07-17

    This project is funded under Bonneville Power Administration (BPA) Strategic Partnership Project (SPP) 17-005 between BPA and SLAC National Accelerator Laboratory. The project in a BPA Technology Improvement Project (TIP) that builds on and validates the Composite Load Model developed by the Western Electric Coordinating Council's (WECC) Load Modeling Task Force (LMTF). The composite load model is used by the WECC Modeling and Validation Work Group to study the stability and security of the western electricity interconnection. The work includes development of load composition data sets, collection of load disturbance data, and model development and validation. This work supports reliable and economic operation of the power system. This report was produced for Deliverable 1A of the BPA TIP-371 Project entitled \\TIP 371: Advancing the Load Composition Model". The deliverable documents the proposed work ow for the Composite Load Model, which provides the basis for the instrumentation, data acquisition, analysis and data dissemination activities addressed by later phases of the project.

  18. A Performance Comparison of Stability, Load-Balancing and Power-Aware Routing Protocols for Mobile Ad Hoc Networks

    Science.gov (United States)

    2010-06-01

    and on-demand protocols like the Dynamic Source Routing (DSR) [5], Ad hoc On-demand Distance Vector ( AODV ) routing [6], Location-aided Routing (LAR...minimum residual battery power of a node in the route . MMBCR can be implemented on the top of any on-demand routing protocol like DSR, AODV and etc...Comparison of Stability, Load-Balancing and Power-Aware Routing Protocols for Mobile Ad Hoc Networks Natarajan Meghanathan1 and Leslie C. Milton2

  19. Physical Modelling of Bucket Foundations Subjected to Axial Loading

    DEFF Research Database (Denmark)

    Vaitkunaite, Evelina

    displacement rates and tensile cyclic loading. A new laboratory testing facility is constructed allowing large scale foundation model testing under long-term cyclic loadings. Another test set-up - a pressure tank – is employed for the displacement rate analysis. The extensive testing campaign provides valuable...

  20. Model Predictive Load Scheduling Using Solar Power Forecasting

    OpenAIRE

    Habib, Abdulelah H.; Kleissl, Jan; de Callafon, Raymond A.

    2016-01-01

    In this paper a model is developed to solve the on/off scheduling of (non-linear) dynamic electric loads based on predictions of the power delivery of a (standalone) solar power source. Knowledge of variations in the solar power output is used to optimally select the timing and the combinations of a set of given electric loads, where each load has a desired dynamic power profile. The optimization exploits the desired power profiles of the electric loads in terms of dynamic power ramp up/down ...

  1. An alternative method for centrifugal compressor loading factor modelling

    Science.gov (United States)

    Galerkin, Y.; Drozdov, A.; Rekstin, A.; Soldatova, K.

    2017-08-01

    The loading factor at design point is calculated by one or other empirical formula in classical design methods. Performance modelling as a whole is out of consideration. Test data of compressor stages demonstrates that loading factor versus flow coefficient at the impeller exit has a linear character independent of compressibility. Known Universal Modelling Method exploits this fact. Two points define the function – loading factor at design point and at zero flow rate. The proper formulae include empirical coefficients. A good modelling result is possible if the choice of coefficients is based on experience and close analogs. Earlier Y. Galerkin and K. Soldatova had proposed to define loading factor performance by the angle of its inclination to the ordinate axis and by the loading factor at zero flow rate. Simple and definite equations with four geometry parameters were proposed for loading factor performance calculated for inviscid flow. The authors of this publication have studied the test performance of thirteen stages of different types. The equations are proposed with universal empirical coefficients. The calculation error lies in the range of plus to minus 1,5%. The alternative model of a loading factor performance modelling is included in new versions of the Universal Modelling Method.

  2. A Simplified Geometric Channel Model for Mobile-to-Mobile Communications

    Directory of Open Access Journals (Sweden)

    K. B. Baltzis

    2011-12-01

    Full Text Available In Mobile-to-Mobile (M2M communications, the communicating nodes are surrounded by scatterers and equipped with low elevation antennas. This paper proposes a simple 2-D geometric scattering model for M2M channels. The model is also applicable in cellular systems when we employ low height base station antennas. In our approach, the scatterers are uniformly distributed in ellipses with arbitrary size and orientation around each communicating node. We provide simple formulas for the calculation of the angular spread and delay variation of the propagating signal. Simulation results verify the accuracy of the model. In order to validate the generalization of the approach, we compare it against notable models in the literature. As an application example, we investigate the impact of scatterer distribution and separation between mobiles on the angle and time of arrival statistics of the multipaths.

  3. A model for equivalent axle load factors

    OpenAIRE

    Amorim, Sara I.R.; Pais, Jorge; Vale, Aline C.; Minhoto, Manuel

    2014-01-01

    Most design methods for road pavements require the design traffic, based on the transformation of the traffic spectrum, to be calculated into a number of equivalent passages of a standard axle using the equivalent axle load factors. Generally, these factors only consider the type of axle (single, tandem or tridem), but they do not consider the type of wheel on the axles, i.e., single or dual wheel. The type of wheel has an important influence on the calculation of the design traffic. The exis...

  4. A Reference Model for Mobile Social Software for Learning

    NARCIS (Netherlands)

    De Jong, Tim; Specht, Marcus; Koper, Rob

    2007-01-01

    De Jong, T., Specht, M., & Koper, R. (2008). A reference model for mobile social software for learning. International Journal of Continuing Engineering Education and Life-Long Learning, 18(1), 118-138.

  5. Study of Self-Organization Model of Multiple Mobile Robot

    OpenAIRE

    Li Shu-qin; Ceng Xian-yi; Xia De-shen

    2006-01-01

    A good organization model of multiple mobile robot should be able to improve the efficiency of the system, reduce the complication of robot interactions, and detract the difficulty of computation. From the sociology aspect of topology, structure and organization, this paper studies the multiple mobile robot organization formation and running mechanism in the dynamic, complicated and unknown environment. It presents and describes in detail a Hierarchical- Web Recursive Organization Model (HWRO...

  6. From Push To Pull: Emerging Models For Mobilizing Resources

    Directory of Open Access Journals (Sweden)

    John Hagel III

    2011-05-01

    Full Text Available The signs are around us.  We are on the cusp of a shift to a new common sense model that will re-shape many facets of our life, including how we identify ourselves, participate with others, connect with others, mobilize resources and learn.  This paper will focus on only one facet of this new common sense model – emerging approaches for mobilizing resources.

  7. The more, the less: age and chemotherapy load are predictive of poor stem cell mobilization in patients with hematologic malignancies

    Institute of Scientific and Technical Information of China (English)

    YANG Shen-miao; CHEN Huan; CHEN Yu-hong; ZHU Hong-hu; ZHAO Ting; LIU Kai-yan

    2012-01-01

    Background Intensive treatment such as autologous peripheral blood stem cell (PBSC) transplantation is an important therapeutic strategy in many hematologic malignancies.A number of factors have been reported to impact PBSC mobilization,but the predictive factors varied from one study to another.This retrospective study assessed our current mobilization and collection protocols,and explored the factors predictive of PBSC mobilization in patients with hematologic malignancies.Methods Data of 64 consecutive patients with hematologic malignancies (multiple myeloma,n=22; acute leukemia,n=27; lymphoma,n=15) who underwent PBSC mobilization for over 1 year were analyzed.Four patients with response to treatment of near complete remission or better were administered granulocyte colony-stimulating factor (G-CSF) to mobilize PBSCs.Sixty patients received G-CSF followed by chemotherapy mobilizing regimens.Poor mobilization (PM) was defined as when ≤2.0×106 CD34+ cells/kg body weight were collected within three leukapheresis procedures.Results The incidence of PM at the first mobilization attempt was 19% (12/64).The PM group was older than the non-PM group (median age,51 vs.40 years; P=0.013).In univariate analysis,there were no significant differences in gender,diagnosis,and body weight between the PM and non-PM groups.A combination of chemotherapy and G-CSF was more effective than G-CSF alone as a mobilizing regimen (P=0.019).Grade Ⅲ or Ⅳ hematopoietic toxicity of chemotherapy had no significant effect on the mobilization efficacy.Supportive care and the incidence of febrile neutropenia were not significantly different between the two groups.In multivariate analysis,age (odds ratio (OR),9.536;P=-0.002) and number of previous chemotherapy courses (OR 3.132; P=0.024) were two independent negative predictive factors for CD34+ cell yield.PM patients could be managed well by remobilization.Conclusion Older age and a heavy load of previous chemotherapy are the negative

  8. Dynamic Load Model using PSO-Based Parameter Estimation

    Science.gov (United States)

    Taoka, Hisao; Matsuki, Junya; Tomoda, Michiya; Hayashi, Yasuhiro; Yamagishi, Yoshio; Kanao, Norikazu

    This paper presents a new method for estimating unknown parameters of dynamic load model as a parallel composite of a constant impedance load and an induction motor behind a series constant reactance. An adequate dynamic load model is essential for evaluating power system stability, and this model can represent the behavior of actual load by using appropriate parameters. However, the problem of this model is that a lot of parameters are necessary and it is not easy to estimate a lot of unknown parameters. We propose an estimating method based on Particle Swarm Optimization (PSO) which is a non-linear optimization method by using the data of voltage, active power and reactive power measured at voltage sag.

  9. Dynamic Regression Intervention Modeling for the Malaysian Daily Load

    Directory of Open Access Journals (Sweden)

    Fadhilah Abdrazak

    2014-05-01

    Full Text Available Malaysia is a unique country due to having both fixed and moving holidays.  These moving holidays may overlap with other fixed holidays and therefore, increase the complexity of the load forecasting activities. The errors due to holidays’ effects in the load forecasting are known to be higher than other factors.  If these effects can be estimated and removed, the behavior of the series could be better viewed.  Thus, the aim of this paper is to improve the forecasting errors by using a dynamic regression model with intervention analysis.   Based on the linear transfer function method, a daily load model consists of either peak or average is developed.  The developed model outperformed the seasonal ARIMA model in estimating the fixed and moving holidays’ effects and achieved a smaller Mean Absolute Percentage Error (MAPE in load forecast.

  10. Dynamical Model of Rocket Propellant Loading with Liquid Hydrogen

    Data.gov (United States)

    National Aeronautics and Space Administration — A dynamical model describing the multi-stage process of rocket propellant loading has been developed. It accounts for both the nominal and faulty regimes of...

  11. Modeling and Simulation of MIMO Mobile-to-Mobile Wireless Fading Channels

    Directory of Open Access Journals (Sweden)

    Gholamreza Bakhshi

    2012-01-01

    Full Text Available Analysis and design of multielement antenna systems in mobile fading channels require a model for the space-time cross-correlation among the links of the underlying multipleinput multiple-output (MIMO Mobile-to-Mobile (M-to-M communication channels. In this paper, we propose the modified geometrical two-ring model, a MIMO channel reference model for M-to-M communication systems. This model is based on the extension of single-bounce two-ring scattering model for flat fading channel under the assumption that the transmitter and the receiver are moving. Assuming single-bounce scattering model in both isotropic and nonisotropic environment, a closed-form expression for the space-time cross-correlation function (CCF between any two subchannels is derived. The proposed model provides an important framework in M-to-M system design, where includes many existing correlation models as special cases. Also, two realizable statistical simulation models are proposed for simulating both isotropic and nonisotropic reference model. The realizable simulation models are based on Sum-of-Sinusoids (SoS simulation model. Finally, the correctness of the proposed simulation models is shown via different simulation scenarios.

  12. Application of neural models as controllers in mobile robot velocity control loop

    Science.gov (United States)

    Cerkala, Jakub; Jadlovska, Anna

    2017-01-01

    This paper presents the application of an inverse neural models used as controllers in comparison to classical PI controllers for velocity tracking control task used in two-wheel, differentially driven mobile robot. The PI controller synthesis is based on linear approximation of actuators with equivalent load. In order to obtain relevant datasets for training of feed-forward multi-layer perceptron based neural network used as neural model, the mathematical model of mobile robot, that combines its kinematic and dynamic properties such as chassis dimensions, center of gravity offset, friction and actuator parameters is used. Neural models are trained off-line to act as an inverse dynamics of DC motors with particular load using data collected in simulation experiment for motor input voltage step changes within bounded operating area. The performances of PI controllers versus inverse neural models in mobile robot internal velocity control loops are demonstrated and compared in simulation experiment of navigation control task for line segment motion in plane.

  13. A model for voltage collapse study considering load characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, L.B. [Companhia de Energia Eletrica da Bahia (COELBA), Salvador, BA (Brazil)

    1994-12-31

    This paper presents a model for analysis of voltage collapse and instability problem considering the load characteristics. The model considers fundamentally the transmission lines represented by exact from through the generalized constants A, B, C, D and the loads as function of the voltage, emphasizing the cases of constant power, constant current and constant impedance. the study treats of the system behavior on steady state and presents illustrative graphics about the problem. (author) 12 refs., 4 figs.

  14. Neuro-fuzzy and model-based motion control for mobile manipulator among dynamic obstacles

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper focuses on autonomous motion control of a nonholonomic platform with a robotic arm, which is called mobile manipulator. It serves in transportation of loads in imperfectly known industrial environments with unknown dynamic obstacles. A union of both procedures is used to solve the general problems of collision-free motion. The problem of collision-free motion for mobile manipulators has been approached from two directions, Planning and Reactive Control. The dynamic path planning can be used to solve the problem of locomotion of mobile platform, and reactive approaches can be employed to solve the motion planning of the arm. The execution can generate the commands for the servo-systems of the robot so as to follow a given nominal trajectory while reacting in real-time to unexpected events. The execution can be designed as an Adaptive Fuzzy Neural Controller. In real world systems, sensor-based motion control becomes essential to deal with model uncertainties and unexpected obstacles.

  15. Analysing an Analytical Solution Model for Simultaneous Mobility

    Directory of Open Access Journals (Sweden)

    Md. Ibrahim Chowdhury

    2013-12-01

    Full Text Available Current mobility models for simultaneous mobility h ave their convolution in designing simultaneous movement where mobile nodes (MNs travel randomly f rom the two adjacent cells at the same time and also have their complexity in the measurement of th e occurrences of simultaneous handover. Simultaneou s mobility problem incurs when two of the MNs start h andover approximately at the same time. As Simultaneous mobility is different for the other mo bility pattern, generally occurs less number of tim es in real time; we analyze that a simplified simultaneou s mobility model can be considered by taking only symmetric positions of MNs with random steps. In ad dition to that, we simulated the model using mSCTP and compare the simulation results in different sce narios with customized cell ranges. The analytical results shows that with the bigger the cell sizes, simultaneous handover with random steps occurrences become lees and for the sequential mobility (where initial positions of MNs is predetermined with ran dom steps, simultaneous handover is more frequent.

  16. A constitutive model for unsaturated cemented soils under cyclic loading

    CERN Document Server

    Yang, C; Pereira, Jean-Michel; Huang, M S

    2008-01-01

    On the basis of plastic bounding surface model, the damage theory for structured soils and unsaturated soil mechanics, an elastoplastic model for unsaturated loessic soils under cyclic loading has been elaborated. Firstly, the description of bond degradation in a damage framework is given, linking the damage of soil's structure to the accumulated strain. The Barcelona Basic Model (BBM) was considered for the suction effects. The elastoplastic model is then integrated into a bounding surface plasticity framework in order to model strain accumulation along cyclic loading, even under small stress levels. The validation of the proposed model is conducted by comparing its predictions with the experimental results from multi-level cyclic triaxial tests performed on a natural loess sampled beside the Northern French railway for high speed train and about 140 km far from Paris. The comparisons show the capabilities of the model to describe the behaviour of unsaturated cemented soils under cyclic loading.

  17. A Forensically Sound Adversary Model for Mobile Devices.

    Directory of Open Access Journals (Sweden)

    Quang Do

    Full Text Available In this paper, we propose an adversary model to facilitate forensic investigations of mobile devices (e.g. Android, iOS and Windows smartphones that can be readily adapted to the latest mobile device technologies. This is essential given the ongoing and rapidly changing nature of mobile device technologies. An integral principle and significant constraint upon forensic practitioners is that of forensic soundness. Our adversary model specifically considers and integrates the constraints of forensic soundness on the adversary, in our case, a forensic practitioner. One construction of the adversary model is an evidence collection and analysis methodology for Android devices. Using the methodology with six popular cloud apps, we were successful in extracting various information of forensic interest in both the external and internal storage of the mobile device.

  18. A Forensically Sound Adversary Model for Mobile Devices.

    Science.gov (United States)

    Do, Quang; Martini, Ben; Choo, Kim-Kwang Raymond

    2015-01-01

    In this paper, we propose an adversary model to facilitate forensic investigations of mobile devices (e.g. Android, iOS and Windows smartphones) that can be readily adapted to the latest mobile device technologies. This is essential given the ongoing and rapidly changing nature of mobile device technologies. An integral principle and significant constraint upon forensic practitioners is that of forensic soundness. Our adversary model specifically considers and integrates the constraints of forensic soundness on the adversary, in our case, a forensic practitioner. One construction of the adversary model is an evidence collection and analysis methodology for Android devices. Using the methodology with six popular cloud apps, we were successful in extracting various information of forensic interest in both the external and internal storage of the mobile device.

  19. Prediction limits of mobile phone activity modelling

    Science.gov (United States)

    Kondor, Dániel; Grauwin, Sebastian; Kallus, Zsófia; Gódor, István; Sobolevsky, Stanislav; Ratti, Carlo

    2017-02-01

    Thanks to their widespread usage, mobile devices have become one of the main sensors of human behaviour and digital traces left behind can be used as a proxy to study urban environments. Exploring the nature of the spatio-temporal patterns of mobile phone activity could thus be a crucial step towards understanding the full spectrum of human activities. Using 10 months of mobile phone records from Greater London resolved in both space and time, we investigate the regularity of human telecommunication activity on urban scales. We evaluate several options for decomposing activity timelines into typical and residual patterns, accounting for the strong periodic and seasonal components. We carry out our analysis on various spatial scales, showing that regularity increases as we look at aggregated activity in larger spatial units with more activity in them. We examine the statistical properties of the residuals and show that it can be explained by noise and specific outliers. Also, we look at sources of deviations from the general trends, which we find to be explainable based on knowledge of the city structure and places of attractions. We show examples how some of the outliers can be related to external factors such as specific social events.

  20. Spreading the Load: Mobile Information and Communications Technologies and Their Effect on Information Overload

    Science.gov (United States)

    Allen, David K.; Shoard, M.

    2005-01-01

    Introduction: We report on a small-scale research project which examined the impact of mobile technologies on the users' experience of information overload. The project focused on a group of worker who have had relatively little attention in both the mobile technology and information overload literatures: senior managers. Method: The case study…

  1. MODELLING AND ANALYSIS OF THE MOBILE PLATFORM UNDER ITS WORK CONDITIONS

    Directory of Open Access Journals (Sweden)

    Rafał GOSZYC

    2014-03-01

    Full Text Available In this work the calculation model of mobile platform, type HAULOTTE - H1150E, and its strength analysis under work conditions have been completed. The model has been obtained by using finite element method with application of the SolidWorks package. The model can be useful as well in static, free vibration and stability analyses for any arbitrary chosen work configuration and load of the object. In the work the sample numerical results concerning the strength and free vibration analysis for the chosen platform work configuration have been presented. The conclusion concerning the analysis results have been added.

  2. Measurement-Based Vehicle Load Model for Urban Expressway Bridges

    Directory of Open Access Journals (Sweden)

    Bin Chen

    2014-01-01

    Full Text Available Significant changes in vehicle loads have occurred in China due to the development of the automobile industry and transportation within the past two decades, particularly the rapid increase in traffic flow and the large-scale emergence of heavy trucks. However, research into vehicle loadings on urban bridges is not well developed. In this study, based on traffic flow data collected using a weigh-in-motion system installed on an expressway in an urban logistics zone, we analyzed the traffic flow, vehicle types, and gross vehicle weight (GVW features and developed models for the vehicle load and fatigue load. According to the axle space, axle types, and axle number, the trucks in the traffic flow were classified into 10 representative vehicle types. The probability distribution of the GVW was fitted to a three-class mixed log-normal distribution. Using the improved Gumbel method, we determined the extreme value distribution of the vehicle loadings in the purpose reference period and assessed the vehicle loadings of urban bridges. In addition, using the equivalent damage theory, six equivalent vehicle models were established according to the measurements of the axle weight and axle space, thereby obtaining a simplified model of fatigue vehicle loadings on urban expressway bridges.

  3. Tube-Load Model Parameter Estimation for Monitoring Arterial Hemodynamics

    Directory of Open Access Journals (Sweden)

    Guanqun eZhang

    2011-11-01

    Full Text Available A useful model of the arterial system is the uniform, lossless tube with parametric load. This tube-load model is able to account for wave propagation and reflection (unlike lumped-parameter models such as the Windkessel while being defined by only a few parameters (unlike comprehensive distributed-parameter models. As a result, the parameters may be readily estimated by accurate fitting of the model to available arterial pressure and flow waveforms so as to permit improved monitoring of arterial hemodynamics. In this paper, we review tube-load model parameter estimation techniques that have appeared in the literature for monitoring wave reflection, large artery compliance, pulse transit time, and central aortic pressure. We begin by motivating the use of the tube-load model for parameter estimation. We then describe the tube-load model, its assumptions and validity, and approaches for estimating its parameters. We next summarize the various techniques and their experimental results while highlighting their advantages over conventional techniques. We conclude the review by suggesting future research directions and describing potential applications.

  4. Tube-Load Model Parameter Estimation for Monitoring Arterial Hemodynamics

    Science.gov (United States)

    Zhang, Guanqun; Hahn, Jin-Oh; Mukkamala, Ramakrishna

    2011-01-01

    A useful model of the arterial system is the uniform, lossless tube with parametric load. This tube-load model is able to account for wave propagation and reflection (unlike lumped-parameter models such as the Windkessel) while being defined by only a few parameters (unlike comprehensive distributed-parameter models). As a result, the parameters may be readily estimated by accurate fitting of the model to available arterial pressure and flow waveforms so as to permit improved monitoring of arterial hemodynamics. In this paper, we review tube-load model parameter estimation techniques that have appeared in the literature for monitoring wave reflection, large artery compliance, pulse transit time, and central aortic pressure. We begin by motivating the use of the tube-load model for parameter estimation. We then describe the tube-load model, its assumptions and validity, and approaches for estimating its parameters. We next summarize the various techniques and their experimental results while highlighting their advantages over conventional techniques. We conclude the review by suggesting future research directions and describing potential applications. PMID:22053157

  5. Accurate Mobility Modeling and Location Prediction Based on Pattern Analysis of Handover Series in Mobile Networks

    Directory of Open Access Journals (Sweden)

    Péter Fülöp

    2009-01-01

    Full Text Available The efficient dimensioning of cellular wireless access networks depends highly on the accuracy of the underlying mathematical models of user distribution and traffic estimations. Mobility prediction also considered as an effective method contributing to the accuracy of IP multicast based multimedia transmissions, and ad hoc routing algorithms. In this paper we focus on the tradeoff between the accuracy and the complexity of the mathematical models used to describe user movements in the network. We propose mobility model extension, in order to utilize user's movement history thus providing more accurate results than other widely used models in the literature. The new models are applicable in real-life scenarios, because these rely on additional information effectively available in cellular networks (e.g. handover history, too. The complexity of the proposed models is analyzed, and the accuracy is justified by means of simulation.

  6. TSI Model 3936 Scanning Mobility Particle Spectrometer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3936 Scanning Mobility Particle Spectrometer (SMPS) measures the size distribution of aerosols ranging from 10 nm up to 1000 nm. The SMPS uses a bipolar aerosol charger to keep particles within a known charge distribution. Charged particles are classified according to their electrical mobility, using a long-column differential mobility analyzer (DMA). Particle concentration is measured with a condensation particle counter (CPC). The SMPS is well-suited for applications including: nanoparticle research, atmospheric aerosol studies, pollution studies, smog chamber evaluations, engine exhaust and combustion studies, materials synthesis, filter efficiency testing, nucleation/condensation studies, and rapidly changing aerosol systems.

  7. Change of Geographic Information Service Model in Mobile Context

    Institute of Scientific and Technical Information of China (English)

    REN Fu; DU Qingyun

    2005-01-01

    A research on that how the topic of mobility, which is completely different but tightly relevant to space, provides new approaches and methods so as to promote the further development of geographic information services, will accumulate basic experience for different types of relative information systems in the wide fields of location based services. This paper analyzes the meaning of mobility and the change for geographic information service model, it describes the differences and correlation between M-GIS and traditional GIS. It sets a technical framework of geographic information services according to mobile context and provides a case study.

  8. Load influence on gear noise. [mathematical model for determining acoustic pressure level as function of load

    Science.gov (United States)

    Merticaru, V.

    1974-01-01

    An original mathematical model is proposed to derive equations for calculation of gear noise. These equations permit the acoustic pressure level to be determined as a function of load. Application of this method to three parallel gears is reported. The logical calculation scheme is given, as well as the results obtained.

  9. Sensor Fusion and Model Verification for a Mobile Robot

    DEFF Research Database (Denmark)

    Bisgaard, Morten; Vinther, Dennis; Østergaard, Kasper Zinck

    2005-01-01

    This paper presents the results of modeling, sensor fusion and model verification for a four-wheel driven, four-wheel steered mobile robot moving in outdoor terrain. The model derived for the robot describes the actuator and wheel dynamics and the vehicle kinematics, and includes friction terms...

  10. Mathematical human modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Hoof, J.F.A.M. van; Lange, R. de

    2001-01-01

    Mathematical modeling of the human body is widely used for automotive crash-safety research and design. Simulations have contributed to a reduction of injury numbers by optimization of vehicle structures and restraint systems. Currently, such simulations are largely performed using occupant models b

  11. Mathematical human modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Hoof, J.F.A.M. van; Lange, R. de

    2001-01-01

    Mathematical modeling of the human body is widely used for automotive crash-safety research and design. Simulations have contributed to a reduction of injury numbers by optimization of vehicle structures and restraint systems. Currently, such simulations are largely performed using occupant models

  12. Mathematical human body modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models

  13. Mathematical human body modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models b

  14. Immune modelling and programming of a mobile robot demo

    Institute of Scientific and Technical Information of China (English)

    GONG Tao; CAI Zi-xing; HE Han-gen

    2006-01-01

    An artificial immune system was modelled with self/non-self selection to overcome abnormity in a mobile robot demo. The immune modelling includes the innate immune modelling and the adaptive immune modelling. The self/non-self selection includes detection and recognition, and the self/non-self detection is based on the normal model of the demo. After the detection, the non-self recognition is based on learning unknown non-self for the adaptive immunization. The learning was designed on the neural network or on the learning mechanism from examples. The last step is elimination of all the non-self and failover of the demo. The immunization of the mobile robot demo is programmed with Java to test effectiveness of the approach. Some worms infected the mobile robot demo, and caused the abnormity. The results of the immunization simulations show that the immune program can detect 100% worms,recognize all known Worms and most unknown worms, and eliminate the worms. Moreover, the damaged files of the mobile robot demo can all be repaired through the normal model and immunization. Therefore, the immune modelling of the mobile robot demo is effective and programmable in some anti-worms and abnormity detection applications.

  15. Experimental validation and calibration of pedestrian loading models for footbridges

    DEFF Research Database (Denmark)

    Ricciardelli, Fransesco; Briatico, C; Ingólfsson, Einar Thór

    2006-01-01

    Different patterns of pedestrian loading of footbridges exist, whose occurrence depends on a number of parameters, such as the bridge span, frequency, damping and mass, and the pedestrian density and activity. In this paper analytical models for the transient action of one walker and for the stat......Different patterns of pedestrian loading of footbridges exist, whose occurrence depends on a number of parameters, such as the bridge span, frequency, damping and mass, and the pedestrian density and activity. In this paper analytical models for the transient action of one walker...... on a model footbridge will be shown, aimed at setting the limits of applicability of the proposed models....

  16. Virtual reality mobility model for wireless ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    Yu Ziyue; Gong Bo; He Xingui

    2008-01-01

    For wireless ad hoc networks simulation.node's mobility pattern and traffic pattern are two key elements.A new simulation model is presented based on the virtual reality collision detection algorithm in obstacle environment,and the model uses the path planning method to avoid obstacles and to compute the node's moving path.Obstacles also affect node's signal propagation.Considering these factors,this study implements the mobility model for wireless ad hoc networks.Simulation results show that the model has a significant impact on the performance of protocols.

  17. Mobilities

    DEFF Research Database (Denmark)

    simple movements of people, goods, and information from A to B. The ‘mobilities turn’ has made it its hallmark to explore the ‘more than’ effects of a world increasingly on the move. This new title in the Routledge Series ‘Critical Concepts in Built Environment’ creates a state-of-the-art reference work......The world is on the move. This is a widespread understanding by many inhabitants of contemporary society across the Globe. But what does it actually mean? During over one decade the ‘mobilities turn’ within the social sciences have provided a new set of insights into the repercussions of mobilities...... to social networks, personal identities, and our relationship to the built environment. The omnipresence of mobilities within everyday life, high politics, technology, and tourism (to mention but a few) all point to a key insight harnessed by the ‘mobilities turn’. Namely that mobilities is much more than...

  18. Comparison of MANET Routing Protocols in Different Traffic and Mobility Models

    Directory of Open Access Journals (Sweden)

    J. Baraković

    2010-06-01

    Full Text Available Routing protocol election in MANET (Mobile Ad Hoc Network is a great challenge, because of its frequent topology changes and routing overhead. This paper compares performances of three routing protocols: Destination Sequenced Distance Vector (DSDV, Ad Hoc Ondemand Distance Vector (AODV and Dynamic Source Routing (DSR, based on results analysis obtained using simulations with different load and mobility scenarios performed with Network Simulator version 2 (NS-2. In low load and low mobility scenarios routing protocols perform in a similar manner. However, with mobility and load increasing DSR outperforms AODV and DSDV protocols.

  19. Vertical bearing capacity of pile based on load transfer model

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ming-hua; YANG Ming-hui; ZOU Xin-jun

    2005-01-01

    The load transfer analytical method is applied to study the bearing mechanism of piles with vertical load in this paper. According to the different hardening rules of soil or rock around the pile shaft, such as work-softening, ideal elasto-plastic and work-hardening, a universal tri-linear load transfer model is suggested for the development of side and tip resistance by various types of soil (rock) with the consideration of sediment at the bottom of the pile. Based on the model, a formula is derived for the relationship between the settlement and load on the pile top to determine the vertical bearing capacity, taking into account such factors as the characteristics of the stratum, the side resistance along the shaft, and tip resistance under the pile tip. A close agreement of the calculated results with the measured data from a field test pile lends confidence to the future application of the present approach in engineering practice.

  20. Biomechanical Modeling Analysis of Loads Configuration for Squat Exercise

    Science.gov (United States)

    Gallo, Christopher A.; Thompson, William K.; Lewandowski, Beth E.; Jagodnik, Kathleen; De Witt, John K.

    2017-01-01

    INTRODUCTION: Long duration space travel will expose astronauts to extended periods of reduced gravity. Since gravity is not present to assist loading, astronauts will use resistive and aerobic exercise regimes for the duration of the space flight to minimize loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Unlike the International Space Station (ISS), the area available for an exercise device in the next generation of spacecraft for travel to the Moon or to Mars is limited and therefore compact resistance exercise device prototypes are being developed. The Advanced Resistive Exercise Device (ARED) currently on the ISS is being used as a benchmark for the functional performance of these new devices. Biomechanical data collection and computational modeling aid the device design process by quantifying the joint torques and the musculoskeletal forces that occur during exercises performed on the prototype devices. METHODS The computational models currently under development utilize the OpenSim [1] software platform, consisting of open source code for musculoskeletal modeling, using biomechanical input data from test subjects for estimation of muscle and joint loads. The OpenSim Full Body Model [2] is used for all analyses. The model incorporates simplified wrap surfaces, a new knee model and updated lower body muscle parameters derived from cadaver measurements and magnetic resonance imaging of young adults. The upper body uses torque actuators at the lumbar and extremity joints. The test subjects who volunteer for this study are instrumented with reflective markers for motion capture data collection while performing squat exercising on the Hybrid Ultimate Lifting Kit (HULK) prototype device (ZIN Technologies, Middleburg Heights, OH). Ground reaction force data is collected with force plates under the feet, and device loading is recorded through load cells internal to the HULK. Test variables include

  1. Mobile phone use while driving: a hybrid modeling approach.

    Science.gov (United States)

    Márquez, Luis; Cantillo, Víctor; Arellana, Julián

    2015-05-01

    The analysis of the effects that mobile phone use produces while driving is a topic of great interest for the scientific community. There is consensus that using a mobile phone while driving increases the risk of exposure to traffic accidents. The purpose of this research is to evaluate the drivers' behavior when they decide whether or not to use a mobile phone while driving. For that, a hybrid modeling approach that integrates a choice model with the latent variable "risk perception" was used. It was found that workers and individuals with the highest education level are more prone to use a mobile phone while driving than others. Also, "risk perception" is higher among individuals who have been previously fined and people who have been in an accident or almost been in an accident. It was also found that the tendency to use mobile phones while driving increases when the traffic speed reduces, but it decreases when the fine increases. Even though the urgency of the phone call is the most important explanatory variable in the choice model, the cost of the fine is an important attribute in order to control mobile phone use while driving. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Illumination modelling of a mobile device environment for effective use in driving mobile apps

    Science.gov (United States)

    Marhoubi, Asmaa H.; Saravi, Sara; Edirisinghe, Eran A.; Bez, Helmut E.

    2015-05-01

    The present generation of Ambient Light Sensors (ALS) of a mobile handheld device suffer from two practical shortcomings. The ALSs are narrow angle, i.e. they respond effectively only within a narrow angle of operation and there is a latency of operation. As a result mobile applications that operate based on the ALS readings could perform sub-optimally especially when operated in environments with non-uniform illumination. The applications will either adopt with unacceptable levels of latency or/and may demonstrate a discrete nature of operation. In this paper we propose a framework to predict the ambient illumination of an environment in which a mobile device is present. The predictions are based on an illumination model that is developed based on a small number of readings taken during an application calibration stage. We use a machine learning based approach in developing the models. Five different regression models were developed, implemented and compared based on Polynomial, Gaussian, Sum of Sine, Fourier and Smoothing Spline functions. Approaches to remove noisy data, missing values and outliers were used prior to the modelling stage to remove their negative effects on modelling. The prediction accuracy for all models were found to be above 0.99 when measured using R-Squared test with the best performance being from Smoothing Spline. In this paper we will discuss mathematical complexity of each model and investigate how to make compromises in finding the best model.

  3. Fuzzy based Cross Layer Feed Back Mechanism for Mobility Aware Load Balanced Routing in WSN

    Directory of Open Access Journals (Sweden)

    R. Ravi

    2015-04-01

    Full Text Available Wireless Sensor Networks (WSNs are made up of small nodes which have the ability to sense, compute and communicate wirelessly. Essential design issue in WSN routing is energy awareness as the sensors are energy constrained. Various routing, power management and data dissemination protocols designed for WSNs are available in the literature. Energy awareness and reliable data transmissions are handled in Medium Access Control (MAC and Network layers. Decisions to achieve data reliability and energy efficiency trade-off were considered in layers. This study considers mobility, energy and link qualities to ward off poor link connectivity which reduce retransmissions and prolong WSN life. To achieve this, a fuzzy based cross layer protocol is proposed using an enhanced MAC protocol to provide better contention during mobility of the node and a network layer protocol based on link quality and mobility is proposed. Input to the fuzzy system is link quality and mobility. Output is decision for cluster head selection.

  4. Holistic Security Model for Mobile Database in Nigeria

    Directory of Open Access Journals (Sweden)

    Fidelis C. Obodoeze

    2016-07-01

    Full Text Available Due to proliferation on the usage of mobile computing devices such as mobile phones, smart phones, Tablet PCs and Portable Digital Assistant (PDA in Nigeria and world over, it is expected that these light-weight, powerful, low-cost computing devices will pave way for data-driven applications in mobile environments. These portal mobile devices can be connected to corporate database and application servers so that application processing can take place at any time and from anywhere. This can throw up a lot of security challenges. Hackers, malicious programs and rival firms can penetrate the corporate servers through various security holes or vulnerabilities. This paper examines these security holes that can emanate from three major windows- the mobile device, the mobile network and the corporate database server and critically x-rays various solutions that can ward them off in order to protect critical data from attack, eavesdropping, disruption, destruction and modification. This paper finally proposes a holistic security model to protect corporate mobile database in Nigeria

  5. Load-balancing algorithms for the parallel community climate model

    Energy Technology Data Exchange (ETDEWEB)

    Foster, I.T.; Toonen, B.R.

    1995-01-01

    Implementations of climate models on scalable parallel computer systems can suffer from load imbalances resulting from temporal and spatial variations in the amount of computation required for physical parameterizations such as solar radiation and convective adjustment. We have developed specialized techniques for correcting such imbalances. These techniques are incorporated in a general-purpose, programmable load-balancing library that allows the mapping of computation to processors to be specified as a series of maps generated by a programmer-supplied load-balancing module. The communication required to move from one map to another is performed automatically by the library, without programmer intervention. In this paper, we describe the load-balancing problem and the techniques that we have developed to solve it. We also describe specific load-balancing algorithms that we have developed for PCCM2, a scalable parallel implementation of the Community Climate Model, and present experimental results that demonstrate the effectiveness of these algorithms on parallel computers. The load-balancing library developed in this work is available for use in other climate models.

  6. Modeling of D-STATCOM in distribution systems load flow

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents modeling of Distribution STATCOM (D-STATCOM) in load flow calculations for the steadystate voltage compensation. An accurate model for D-STATCOM is derived to use in load flow calculations. The rating of this device as well as the direction of required reactive power injection for voltage compensation in the desired value (1 p.u.) is derived and discussed analytically and mathematically by the phasor diagram method. Furthermore, an efficient method for node and line identification used in load flow calculations is presented. The validity of the proposed model is examined by using two standard distribution systems consisting of 33 and 69 nodes, respectively. The best location of D-STATCOM for under voltage problem mitigation approach in the distribution networks is determined. The results validate the proposed model for DSTATCOM in large distribution systems.

  7. A Review on Mobile Device's Digital Forensic Process Models

    Directory of Open Access Journals (Sweden)

    Anahita Farjamfar

    2014-07-01

    Full Text Available The main purpose of this study is to discuss the different comparative studies on digital forensics process models specially in the field of mobile devices. In order to legally pursue digital criminals, investigation should be conducted in a forensically sound manner so that the acquired evidence would be accepted in the court of law. Digital forensic process models define the important steps that should be followed to assure the investigation is performed successfully. There are a number of digital forensic process models developed by various organizations worldwide, but yet, there is no agreement among forensics investigation and legislative delegation which procedures to adhere to; specially in the case of facing mobile devices with latest technologies. This is vital, as mobile phones and other mobile devices such as PDAs or tablets are becoming ever-present as the main technology platform around the world and people are obtaining and using mobile phones more than ever. In this study we will give a review of the proposed digital forensics process models within last 7 years and to discuss the need for a consensus to follow the same underlying approaches while continually updating digital forensics process models to cover new emerging technologies and devices.

  8. A COLLABORATIVE LOCATION MODEL FOR CELLULAR MOBILE POSITION LOCATION

    Institute of Scientific and Technical Information of China (English)

    Deng Ping; Liu Lin; Fan Pingzhi

    2004-01-01

    In cellular network, several Time Difference Of Arrival (TDOA) location algorithms can be applied to mobile position estimation. However, each algorithm has its own limitations and none of them is proved to be the most reliable one in different channel environments. In this paper Kleine-Ostmann's data fusion model is modified and a collaborative location model which incorporates position estimate of two TDOA location algorithms is proposed.Analysis and simulation show that more reliable and accurate mobile position estimation can be achieved based on this model.

  9. A cellular automaton evacuation model based on mobile robot's behaviors

    Institute of Scientific and Technical Information of China (English)

    WENG WenGuo; YUAN HongYong; FAN WeiCheng

    2007-01-01

    The research of evacuation in some emergencies, e.g. fire, is of great benefit to reducing the injuries of persons. In this paper, a cellular automaton evacuation model based on mobile robot's behaviors is presented. Each person is treated as an intelligent mobile robot, and motor schemas, including move-to-goal, avoid-obstacle, swirl-obstacle and nervous-motion, drive persons to interact with their environment. The motor schemas are combined with cellular automaton theory, and an evacuation model is built. Evacuation simulation of persons with different move velocities shows that the presented model can predict accurately the evacuation phenomena in some emergencies.

  10. Performance Comparison Study of Connected Dominating Set Algorithms for Mobile Ad hoc Networks under Different Mobility Models

    Directory of Open Access Journals (Sweden)

    Natarajan Meghanathan

    2013-05-01

    Full Text Available The high-level contribution of this paper is an exhaustive simulation-based comparison study of three categories (density, node id and stability-based of algorithms to determine connected dominating sets (CDS for mobile ad hoc networks and evaluate their performance under two categories (random node mobility and grid-based vehicular ad hoc network of mobility models. The CDS algorithms studied are the maximum density-based (MaxD-CDS, node ID-based (ID-CDS and the minimum velocity-based (MinV-CDS algorithms representing the density, node id and stability categories respectively. The node mobility models used are the Random Waypoint model (representing random node mobility and the City Section and Manhattan mobility models (representing the grid-based vehicular ad hoc networks. The three CDS algorithms under the three mobility models are evaluated with respect to two critical performance metrics: the effective CDS lifetime (calculated taking into consideration the CDS connectivity and absolute CDS lifetime and the CDS node size. Simulations are conducted under a diverse set of conditions representing low, moderate and high network density, coupled with low, moderate and high node mobility scenarios. For each CDS, the paper identifies the mobility model that can be employed to simultaneously maximize the lifetime and minimize the node size with minimal tradeoff. For the two VANET mobility models, the impact of the grid block length on the CDS lifetime and node size is also evaluated.

  11. A universal model for mobility and migration patterns.

    Science.gov (United States)

    Simini, Filippo; González, Marta C; Maritan, Amos; Barabási, Albert-László

    2012-02-26

    Introduced in its contemporary form in 1946 (ref. 1), but with roots that go back to the eighteenth century, the gravity law is the prevailing framework with which to predict population movement, cargo shipping volume and inter-city phone calls, as well as bilateral trade flows between nations. Despite its widespread use, it relies on adjustable parameters that vary from region to region and suffers from known analytic inconsistencies. Here we introduce a stochastic process capturing local mobility decisions that helps us analytically derive commuting and mobility fluxes that require as input only information on the population distribution. The resulting radiation model predicts mobility patterns in good agreement with mobility and transport patterns observed in a wide range of phenomena, from long-term migration patterns to communication volume between different regions. Given its parameter-free nature, the model can be applied in areas where we lack previous mobility measurements, significantly improving the predictive accuracy of most of the phenomena affected by mobility and transport processes.

  12. Probabilistic traffic load model for short-span city bridges

    NARCIS (Netherlands)

    Hellebrandt, L.; Blom, C.B.M.; Steenbergen, R.D.J.M.

    2014-01-01

    In the coming years numerous existing traffic bridges in cities are subject to re-evaluation. In this paper a new probabilistic traffic load model for short-span bridges is proposed. As an example, site-specific weigh-in-motion data from Rotterdam, the Netherlands, is included in the model. The

  13. A constitutive model for unsaturated cemented soils under cyclic loading

    OpenAIRE

    2008-01-01

    International audience; On the basis of plastic bounding surface model, the damage theory for structured soils and unsaturated soil mechanics, an elastoplastic model for unsaturated loessic soils under cyclic loading has been elaborated. Firstly, the description of bond degradation in a damage framework is given, linking the damage of soil's structure to the accumulated strain. The Barcelona Basic Model (BBM) was considered for the suction effects. The elastoplastic model is then integrated i...

  14. Economic inequality and mobility in kinetic models for social sciences

    Science.gov (United States)

    Letizia Bertotti, Maria; Modanese, Giovanni

    2016-10-01

    Statistical evaluations of the economic mobility of a society are more difficult than measurements of the income distribution, because they require to follow the evolution of the individuals' income for at least one or two generations. In micro-to-macro theoretical models of economic exchanges based on kinetic equations, the income distribution depends only on the asymptotic equilibrium solutions, while mobility estimates also involve the detailed structure of the transition probabilities of the model, and are thus an important tool for assessing its validity. Empirical data show a remarkably general negative correlation between economic inequality and mobility, whose explanation is still unclear. It is therefore particularly interesting to study this correlation in analytical models. In previous work we investigated the behavior of the Gini inequality index in kinetic models in dependence on several parameters which define the binary interactions and the taxation and redistribution processes: saving propensity, taxation rates gap, tax evasion rate, welfare means-testing etc. Here, we check the correlation of mobility with inequality by analyzing the mobility dependence from the same parameters. According to several numerical solutions, the correlation is confirmed to be negative.

  15. Modeling, Estimation, and Control of Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten

    This thesis treats the subject of autonomous helicopter slung load flight and presents the reader with a methodology describing the development path from modeling and system analysis over sensor fusion and state estimation to controller synthesis. The focus is directed along two different....... To enable slung load flight capabilities for general cargo transport, an integrated estimation and control system is developed for use on already autonomous helicopters. The estimator uses vision based updates only and needs little prior knowledge of the slung load system as it estimates the length...... of the suspension system together with the system states. The controller uses a combined feedforward and feedback approach to simultaneously prevent exciting swing and to actively dampen swing in the slung load. For the mine detection application an estimator is developed that provides full system state information...

  16. Modelling of a chaotic load of wind turbines drivetrain

    Science.gov (United States)

    Bielecki, Andrzej; Barszcz, Tomasz; Wójcik, Mateusz

    2015-03-01

    The purpose of this paper is to present a model of the load of the wind turbine gears for simulation of real, varying operational conditions for modelling of wind turbine vibration. The characteristics of the wind, which generates chaotically varying loads on the drivetrain components generating load in teeth and bearings of gears during torque transfer, are discussed. A generator of variable load of wind turbines drivetrain is proposed. Firstly, the module for generation of wind speed is designed. It is based on the approach in which the wind speed was considered as a time series approximated by the Weierstrass function. Secondly, the rotational speed of the main shaft is proposed as a function of the wind speed value. The function depends on a few parameters that are fitted by using a genetic algorithm. Finally, the model of torque of the main shaft is introduced. This model has been created by using a multi-layer artificial neural network. The results show that the proposed approach yields a very good fit for the experimental data. The fit brings about the proper reproducing of all the aspects of the load that are crucial for causing fatigue and, as a consequence, damaging of gears of the wind turbines.

  17. Modelling the Load Torques of Electric Drive for Polymerization Process

    Directory of Open Access Journals (Sweden)

    Andrzej Popenda

    2007-01-01

    Full Text Available The problems of mathematical modelling the load torques on shaft of driving motor designed for applications in polymerization reactors are presented in the paper. The real load of polymerization drive is determined as a function of angular velocity. Mentioned function results from friction in roll-formed slide bearing as well as from friction of ethylene molecules with mixer arms in polymerization reactor chamber. Application of mathematical formulas concerning the centrifugal ventilator is proposed to describe the mixer in reactor chamber. The analytical formulas describing the real loads of polymerization drive are applied in mathematical modelling the power unit of polymerization reactor with specially designed induction motor. The numerical analysis of transient states was made on the basis of formulated mathematical model. Examples of transient responses and trajectories resulting from analysis are presented in the paper.

  18. Load and Flexibility Models for Distribution Grid Management

    DEFF Research Database (Denmark)

    Kouzelis, Konstantinos

    changing the energy flow in low voltage distribution grids, several grid complications are bound to emerge like, for instance, capacity adequacy limitations, power quality issues, reverse power flows etc. One of the Distribution System Operator options to manage these complications is to proceed...... so as to cope with load and generation changes is indeed innovative; nevertheless, its implementation is, up to day, impaired by many practical difficulties. In this Ph.D. study, four of these issues are detected, elaborated and consequently solved by dedicated grid and/or load models. These issues......, a simple, generic, and automated load forecasting technique based on machine learning principles is proposed. Unlike other benchmark forecasting models, this non-parametric approach does not introduce any assumptions regarding the system model and is solely based on past observations. Thus, this method...

  19. [The influence of the leg load and the support mobility under leg on the anticipatory postural adjustment].

    Science.gov (United States)

    Kazennikov, O V; Kireeva, T B; Shlykov, V Iu

    2015-01-01

    Anticipatory postural adjustment is an essential part of equilibrium maintainance during standing in human. So changes in stance condition could affect both control of equilibrium and anticipatory adjustment. Anticipatory changes in the stabilogram of each leg were studied in standing subject during the early stage of quick right arm lifting while legs were on two separated supports. The center of pressure (CP) movement was analyzed in three variants of experiment: both legs on immovable support, with only right leg on the movable support and with only left leg on the moveable support. In each standing condition subject stood with symmetrical load on two legs or with the load voluntary transferred to one leg. The anticipatory CP shift depended on the mobility of the support under the leg and on loading of the leg. While standing on unmovable supports with symmetrical load on the legs before lifting of the right arm CP of right leg shifted backward and CP of left leg--forward. While standing with one leg on movable support the anticipatory CP shift of this leg was small and did not depend on the load on the leg. However the shift of CP of the leg that was placed on the unmovable support depended on the load in the same way as in the case when both legs were on unmovable supports. Results suggested that since on movable support the support and proprioceptive afferent flow from distal part of the leg that was did not supply unambiguous information about body position, the role of distal joints in posture control is reduced.

  20. Sensor Fusion and Model Verification for a Mobile Robot

    OpenAIRE

    Bisgaard, Morten; Vinther, Dennis; Østergaard, Kasper Zinck; Bendtsen, Jan Dimon; Izadi-Zamanabadi, Roozbeh

    2005-01-01

    This paper presents the results of modeling, sensor fusion and model verification for a four-wheel driven, four-wheel steered mobile robot moving in outdoor terrain. The model derived for the robot describes the actuator and wheel dynamics and the vehicle kinematics, and includes friction terms as well as slip. An Unscented Kalman Filter (UKF) based on the dynamic model is used for sensor fusion, feeding sensor measurements back to the robot controller in an intelligent manner. Through practi...

  1. The Design and Implementation of a Novel Skew Scenario Model in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    N. Vetrivelan

    2010-01-01

    Full Text Available Problem statement: In this research, it had been presented a novel Skew Scenario Model that has been developed and implemented for mobile ad hoc networks. There exist several mobility patterns that try to capture the behavior of the mobile devices under different circumstances, whereas in our work, the direction movement of the nodes is significantly specified horizontally, vertically and diagonally in the simulation area. Approach: Our novel Skew Scenario Model and the impact of mobility on MANET protocols had been compared and analyzed. The performance of DSDV and DSR under SSM in terms of packet delivery fraction, routing load and latency for varying source and destination traffic from 10, 20, 30, 40 and 50 under 100 nodes environment had been analyzed. Apart from this, our SSM with the existing waypoint model in 100 nodes environment had been compared. A suitable algorithm for SSM has also been developed. Results: Our simulation result showed that the functioning of our SSM had greatly influenced the performance of routing protocols in MANET environment. Simulation experiments confirm that for DSR under SSM, the PDF is highest between 93.56-99.43%, routing load is lowest between 1.005-1.068 and Latency is very less between 0.0163-0.049 sec, in the case of DSDV under SSM, the PDF is 63.22-79.104%, routing load is 1.20-1.58 and latency is 0.018-0.050 sec. The result revealed the fact that the reactive routing protocol DSR outperforms much more than the Proactive routing protocol DSDV. Our Novel Model has performed well when we compared it with existing waypoint mobility model while setting many source-destination connections. In DSR under SSM and waypoint model, PDF is between 93.56-99.43% in SSM and in waypoint 94.20-98.88%. Routing load in SSM is 1.0056-1.068, waypoint 1.01-1.06 seconds. Latency is between 0.026-0.063 in SSM and in waypoint 0.026-0.1235 sec. Conclusion: This study revealed the fact that the DSR discovers new routes faster

  2. Mobile learning: a comparison of knowledge acquisition between two mobile course models

    Directory of Open Access Journals (Sweden)

    Antonio Giardi

    2017-01-01

    Full Text Available Mobile has become the preferred way for internet access. This important change has generated transformations “equally important” in education and teaching fields, significantly increasing the importance of mobile learning. Using the User-Centered Design and Participatory Planning methodologies, 20 university students were involved in the mobile course model design, defined as “USiena model”. The objective of this research was to compare the model course designed with a model course used by other institutions present in iTunesU platform, hereinafter described as a “Sparring model”. Using the experimental method, 32 students were involved in a “pilot study” built to evaluate the learning level of both models, comparing the knowledge acquired by learners. The experimental hypothesis was that the USiena model, compared to the Sparring model, would facilitate the contents transmission to learners improving learning.  The results of the experimentation confirmed our hypothesis.Mobile learning: una comparazione sull’acquisizione della conoscenza utilizzando due modelli di corsoIl mobile è diventato la modalità privilegiata per l’accesso a internet. Questo importante cambiamento ha generato trasformazioni “altrettanto importanti” nel campo dell’istruzione e dell’insegnamento, facendo aumentare sensibilmente l’importanza dell’apprendimento in mobilità. Utilizzando le metodologie dello User-Centered Design e del Participatory Planning, 20 studenti universitari sono stati coinvolti nella progettazione di un modello di corso mobile, da ora in avanti definito come “modello USiena”. L’obiettivo della presente ricerca era di comparare il modello di corso che è stato progettato, con uno dei modelli di corso utilizzati da altre istituzioni presenti nella piattaforma iTunesU, di seguito descritto come “modello Sparring”. Utilizzando il metodo sperimentale, 32 studenti sono stati coinvolti in uno “studio pilota

  3. A Simple Hybrid Model for Short-Term Load Forecasting

    Directory of Open Access Journals (Sweden)

    Suseelatha Annamareddi

    2013-01-01

    Full Text Available The paper proposes a simple hybrid model to forecast the electrical load data based on the wavelet transform technique and double exponential smoothing. The historical noisy load series data is decomposed into deterministic and fluctuation components using suitable wavelet coefficient thresholds and wavelet reconstruction method. The variation characteristics of the resulting series are analyzed to arrive at reasonable thresholds that yield good denoising results. The constitutive series are then forecasted using appropriate exponential adaptive smoothing models. A case study performed on California energy market data demonstrates that the proposed method can offer high forecasting precision for very short-term forecasts, considering a time horizon of two weeks.

  4. Blast Load Simulator Experiments for Computational Model Validation: Report 2

    Science.gov (United States)

    2017-02-01

    O’Daniel, 2016. Blast load simulator experiments for computational model validation – Report 1. ERDC/GSL TR-16-27. Vicksburg, MS: U.S. Army Engineer ...ER D C/ G SL T R- 16 -2 7 Blast Load Simulator Experiments for Computational Model Validation Report 2 G eo te ch ni ca l a nd S tr uc...Approved for public release; distribution is unlimited. The U.S. Army Engineer Research and Development Center (ERDC) solves the nation’s toughest

  5. Modeling vertical loads in pools resulting from fluid injection. [BWR

    Energy Technology Data Exchange (ETDEWEB)

    Lai, W.; McCauley, E.W.

    1978-06-15

    Table-top model experiments were performed to investigate pressure suppression pool dynamics effects due to a postulated loss-of-coolant accident (LOCA) for the Peachbottom Mark I boiling water reactor containment system. The results guided subsequent conduct of experiments in the /sup 1///sub 5/-scale facility and provided new insight into the vertical load function (VLF). Model experiments show an oscillatory VLF with the download typically double-spiked followed by a more gradual sinusoidal upload. The load function contains a high frequency oscillation superimposed on a low frequency one; evidence from measurements indicates that the oscillations are initiated by fluid dynamics phenomena.

  6. Symplectic Modeling of Beam Loading in Electromagnetic Cavities

    CERN Document Server

    Abell, Dan T; Webb, Stephen D

    2016-01-01

    Simulating beam loading in radiofrequency accelerating structures is critical for understanding higher-order mode effects on beam dynamics, such as beam break-up instability in energy recovery linacs. Full wave simulations of beam loading in radiofrequency structures are computationally expensive, while reduced models can ignore essential physics and can be difficult to generalize. We present a self-consistent algorithm derived from the least-action principle which can model an arbitrary number of cavity eigenmodes and with a generic beam distribution.

  7. Computer modeling of ORNL storage tank sludge mobilization and mixing

    Energy Technology Data Exchange (ETDEWEB)

    Terrones, G.; Eyler, L.L.

    1993-09-01

    This report presents and analyzes the results of the computer modeling of mixing and mobilization of sludge in horizontal, cylindrical storage tanks using submerged liquid jets. The computer modeling uses the TEMPEST computational fluid dynamics computer program. The horizontal, cylindrical storage tank configuration is similar to the Melton Valley Storage Tanks (MVST) at Oak Ridge National (ORNL). The MVST tank contents exhibit non-homogeneous, non-Newtonian rheology characteristics. The eventual goals of the simulations are to determine under what conditions sludge mobilization using submerged liquid jets is feasible in tanks of this configuration, and to estimate mixing times required to approach homogeneity of the contents of the tanks.

  8. Role Models for boosting mobility of women scientists in geosciences

    Science.gov (United States)

    Avellis, Giovanna; Theodoridou, Magdalini

    2017-04-01

    More and more women today are choosing to study science and undertake scientific careers. Likewise mobility during one's career is increasingly important as research tends to be undertaken via international collaboration, often within networks based on the researchers mobility, especially in geosciences. We have developed an ebook on Role Models for boosting mobility of women scientists to showcase the careers of women scientists who have undertaken mobility during their careers. It is hoped that their stories will provide young women who are just starting out in their science careers with inspirational role models, and that these stories give them realistic information about career opportunities: many of them are women scientists in geosciences. These are not famous scientists, but rather real examples of people who express all the passion of the world of science. It is hoped that reading about successful scientists who have achieved a healthy work-life balance while moving to new locations will be particularly helpful for those individuals considering mobility in their own career. The ebook is available to be used by programs that support the development of systematic approaches to increasing the representation and advancement of women in science, engineering and technology, since mobility plays a key role in these programs. The stories contained herein will be useful to mentoring or advising program focusing on career, networking opportunities, discussion and grants opportunities in conjunction with mobility. There is still a gap between female graduates and the pool of female job applicants - even though the proportion of female graduate students and postdocs in most scientific fields is higher today than it is ever been. Therefore we suggest that focus should be placed on examining the real challenges which women need to overcome, particularly when "mobility" comes into play. Role models who have overcome these challenges will continue to play an important

  9. COMPARISON BETWEEN MODELS FOR CALCULATION OF INDUSTRIAL HOT ROLLING LOADS

    Directory of Open Access Journals (Sweden)

    Antonio Augusto Gorni

    2012-09-01

    Full Text Available An evaluation is made about the precision of hot strip rolling mill loads at the F1 stand calculated according to the theoretical models of Orowan, Sims, Alexander-Ford, Orowan-Pascoe, Ekelund and Tselikov in comparison to real values got for carbon-manganese steels. In the deterministic approach, without any fit of the calculated values to real data, Orowan, Sims and Alexander-Models show best levels of precision, as expected from the information got in the literature. However, in the semi-empirical approach, after a linear fit between calculated values and real data, Tselikov and Ekelund models show better adequacy to the industrial data, a fact that can be attributed to more significant errors occurring in the sub-models of temperature, tribology and hot strength than in the rolling load models. For its turn, neural network models show the best levels of precision which make very attractive the adoption of this approach.

  10. A Mobile-based Platform for Big Load Profiles Data Analytics in Non-Advanced Metering Infrastructures

    Directory of Open Access Journals (Sweden)

    Moussa Sherin

    2016-01-01

    Full Text Available With the rapidly increase of electricity demand around the world due to industrialization and urbanization, this turns the availability of precise knowledge about the consumption patterns of consumers to a valuable asset for electricity providers, given the current competitive electricity market. This would allow them to provide satisfactory services in time of load peaks and to control fraud and abuse cases. Despite of this crucial necessity, this is currently very hard to achieve in many developing countries since smart meters or advanced metering infrastructures (AMIs are not yet settled there to monitor and report energy usages. Whereas the communication and information technologies have widely emerged in such nations, allowing the enormous spread of smart devices among population. In this paper, we present mobile-based BLPDA, a novel platform for big data analytics of consumerss’ load profiles (LPs in the absence of AMIs’ establishment. The proposed platform utilizes mobile computing in order to collect the consumptions of consumers, build their LPs, and analyze the aggregated usages data. Thus, allowing electricity providers to have better vision for an enhanced decision making process. The experimental results emphasize the effectiveness of our platform as an adequate alternative for AMIs in developing countries with minimal cost.

  11. The Impact of Supported and Annotated Mobile Learning on Achievement and Cognitive Load

    Science.gov (United States)

    Shadiev, Rustam; Hwang, Wu-Yuin; Huang, Yueh-Min; Liu, Tzu-Yu

    2015-01-01

    We designed activities for learning English as a foreign language in a mobile learning environment with familiar authentic support for this study. Students learned at school and then applied their newly gained knowledge to solve daily life problems by first using a tablet to take pictures of objects they wished to learn about, then describing them…

  12. Learning Anatomy via Mobile Augmented Reality: Effects on Achievement and Cognitive Load

    Science.gov (United States)

    Küçük, Sevda; Kapakin, Samet; Göktas, Yüksel

    2016-01-01

    Augmented reality (AR), a new generation of technology, has attracted the attention of educators in recent years. In this study, a MagicBook was developed for a neuroanatomy topic by using mobile augmented reality (mAR) technology. This technology integrates virtual learning objects into the real world and allow users to interact with the…

  13. The analysis of reactively loaded microstrip antennas by finite difference time domain modelling

    Science.gov (United States)

    Hilton, G. S.; Beach, M. A.; Railton, C. J.

    1990-01-01

    In recent years, much interest has been shown in the use of printed circuit antennas in mobile satellite and communications terminals at microwave frequencies. Although such antennas have many advantages in weight and profile size over more conventional reflector/horn configurations, they do, however, suffer from an inherently narrow bandwidth. A way of optimizing the bandwidth of such antennas by an electronic tuning technique using a loaded probe mounted within the antenna structure is examined, and the resulting far-field radiation patterns are shown. Simulation results from a 2D finite difference time domain (FDTD) model for a rectangular microstrip antenna loaded with shorting pins are given and compared to results obtained with an actual antenna. It is hoped that this work will result in a design package for the analysis of microstrip patch antenna elements.

  14. Modeling on Flash Flood Disaster Induced by Bed Load

    Institute of Scientific and Technical Information of China (English)

    CAO Shuyou; LIU Xingnian; HUANG Er; YANG Keiun

    2008-01-01

    Flash floods result from a complex interaction among hydro-meteorological, hydrologi-cal, and hydraulic processes across various spatial and temporal scales. Sichuan Province suffers flash floods frequently owing to mountain weather and topography. A flash flood and gravel bed load transport are two key relative problems in mountain river engineering. Bed materials are often encountered in alternate scouring and deposition in mountain fluvial processes during a flash flood.In this circumstance, CRS-1 bed load numerical model jointly with scale physical model is em-ployed to predict water level and gravel bed scour and deposition for design of flood control dykes and flash flood disaster mitigation. A case study on the mechanism of a flash flood disaster in-duced by bed load transport for a hydropower station in Sichuan Province is conducted. Finally,suggestions to protect the hydropower station are proposed.

  15. Identifiability and identification of a Synthesis Load Model

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A Synthesis Load Model (SLM) including both the power load and the distribution network has been proposed in the references. The identifiability of SLM is analyzed at first, it is concluded that the model parameters are identifiable if one of the resistance, reactance and the ratio of them is known. The conclusion is validated through a simulation example. A strategy for parameter identification of SLM is proposed with the combination of the component based approach and the measurement based approach. During parameter identification, only the key parameters playing very important roles in the dynamics of the load and the system are estimated, while the other parameters playing limited role are set as the default values. The proposed strategy is verified by the field measurements.

  16. Numerical modeling of centrifuge cyclic lateral pile load experiments

    Institute of Scientific and Technical Information of China (English)

    Nikos Gerolymos; Sandra Escoffer; George Gazetas; Jacques Gamier

    2009-01-01

    To gain insight into the inelastic behavior of piles, the response of a vertical pile embedded in dry sand and subjected to cyclic lateral loading was studied experimentally in centrifuge tests conducted in Laboratoire Central des Ponts et Chaussees. Three types of cyclic loading were applied, two asymmetric and one symmetric with respect to the unloaded pile. An approximately square-root variation of soil stiffness with depth was obtained from indirect in-flight density measurements, laboratory tests on reconstituted samples, and well-established empirical correlations. The tests were simulated using a cyclic nonlinear Winkler spring model, which describes the full range of inelastic phenomena, including separation and re-attachment of the pile from and to the soil. The model consists of three mathematical expressions capable of reproducing a wide variety of monotonic and cyclic experimental p-y curves. The physical meaning of key model parameters is graphically explained and related to soil behavior. Comparisons with the centrifuge test results demonstrate the general validity of the model and its ability to capture several features of pile-soil interaction, including: soil plastification at an early stage of loading, "pinching" behavior due to the formation of a relaxation zone around the upper part of the pile, and stiffness and strength changes due to cyclic loading. A comparison of the p-y curves derived from the test results and the proposed model, as well as those from the classical curves of Reese et al. (1974) for sand, is also presented.

  17. Dynamic queuing transmission model for dynamic network loading

    DEFF Research Database (Denmark)

    Raovic, Nevena; Nielsen, Otto Anker; Prato, Carlo Giacomo

    2017-01-01

    This paper presents a new macroscopic multi-class dynamic network loading model called Dynamic Queuing Transmission Model (DQTM). The model utilizes ‘good’ properties of the Dynamic Queuing Model (DQM) and the Link Transmission Model (LTM) by offering a DQM consistent with the kinematic wave theory...... and allowing for the representation of multiple vehicle classes, queue spillbacks and shock waves. The model assumes that a link is split into a moving part plus a queuing part, and p that traffic dynamics are given by a triangular fundamental diagram. A case-study is investigated and the DQTM is compared...

  18. Computer modeling of road bridge for simulation moving load

    Directory of Open Access Journals (Sweden)

    Miličić Ilija M.

    2016-01-01

    Full Text Available In this paper is shown computational modelling one span road structures truss bridge with the roadway on the upper belt of. Calculation models were treated as planar and spatial girders made up of 1D finite elements with applications for CAA: Tower and Bridge Designer 2016 (2nd Edition. The conducted computer simulations results are obtained for each comparison of the impact of moving load according to the recommendations of the two standards SRPS and AASHATO. Therefore, it is a variant of the bridge structure modeling application that provides Bridge Designer 2016 (2nd Edition identical modeled in an environment of Tower. As important information for the selection of a computer applications point out that the application Bridge Designer 2016 (2nd Edition we arent unable to treat the impacts moving load model under national standard - V600. .

  19. Mobility dependent recombination models for organic solar cells

    Science.gov (United States)

    Wagenpfahl, Alexander

    2017-09-01

    Modern solar cell technologies are driven by the effort to enhance power conversion efficiencies. A main mechanism limiting power conversion efficiencies is charge carrier recombination which is a direct function of the encounter probability of both recombination partners. In inorganic solar cells with rather high charge carrier mobilities, charge carrier recombination is often dominated by energetic states which subsequently trap both recombination partners for recombination. Free charge carriers move fast enough for Coulomb attraction to be irrelevant for the encounter probability. Thus, charge carrier recombination is independent of charge carrier mobilities. In organic semiconductors charge carrier mobilities are much lower. Therefore, electrons and holes have more time react to mutual Coulomb-forces. This results in the strong charge carrier mobility dependencies of the observed charge carrier recombination rates. In 1903 Paul Langevin published a fundamental model to describe the recombination of ions in gas-phase or aqueous solutions, known today as Langevin recombination. During the last decades this model was used to interpret and model recombination in organic semiconductors. However, certain experiments especially with bulk-heterojunction solar cells reveal much lower recombination rates than predicted by Langevin. In search of an explanation, many material and device properties such as morphology and energetic properties have been examined in order to extend the validity of the Langevin model. A key argument for most of these extended models is, that electron and hole must find each other at a mutual spatial location. This encounter may be limited for instance by trapping of charges in trap states, by selective electrodes separating electrons and holes, or simply by the morphology of the involved semiconductors, making it impossible for electrons and holes to recombine at high rates. In this review, we discuss the development of mobility limited

  20. Mobile, Alabama Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico....

  1. A Liquid-Solid Coupling Hemodynamic Model with Microcirculation Load

    Directory of Open Access Journals (Sweden)

    Bai Li

    2016-01-01

    Full Text Available From the aspect of human circulation system structure, a complete hemodynamic model requires consideration of the influence of microcirculation load effect. This paper selected the seepage in porous media as the simulant of microcirculation load. On the basis of a bi-directional liquid-solid coupling tube model, we built a liquid-solid-porous media seepage coupling model. The simulation parameters accorded with the physiological reality. Inlet condition was set as transient single-pulse velocity, and outlet as free outlet. The pressure in the tube was kept at the state of dynamic stability in the range of 80–120 mmHg. The model was able to simulate the entire propagating process of pulse wave. The pulse wave velocity simulated was 6.25 m/s, which accorded with the physiological reality. The complex pressure wave shape produced by reflections of pressure wave was also observed. After the model changed the cardiac cycle length, the pressure change according with actual human physiology was simulated successfully. The model in this paper is well-developed and reliable. It demonstrates the importance of microcirculation load in hemodynamic model. Moreover the properties of the model provide a possibility for the simulation of dynamic adjustment process of human circulation system, which indicates a promising prospect in clinical application.

  2. 101 Modelling and Forecasting Periodic Electric Load for a ...

    African Journals Online (AJOL)

    User

    2012-01-24

    Jan 24, 2012 ... In this work, three models are used to analyze the electric load capacity of a ..... Forecasting electricity prices for a day-ahead pool-based electric energy market. ... Control, Operation and Management, Hong Kong pgs.782–7.

  3. An Innovative Model for Training Orientation and Mobility Assistants.

    Science.gov (United States)

    Wiener, W. R.

    1993-01-01

    A model was developed to prepare specialists in orientation and mobility (O&M) who work with people with visual impairments, with the specialists in turn training and supervising O&M assistants. The project developed curriculum guidelines, training methods, a national workshop, and regional seminars. (DB)

  4. Model Programmes and Practice Issues in Orientation and Mobility.

    Science.gov (United States)

    Hill, Mary-Maureen; Hill, Everett W.

    1990-01-01

    Discusses diversity in the population of individuals with visual impairments, the changing role of orientation and mobility (O&M) specialists, and the broadened definition of O&M. An overview of best practices and model demonstration programs for providing O&M services to a diverse population of persons with visual impairments is presented. (SM)

  5. A Performance Comparison of Stability, Load-Balancing and Power-Aware Routing Protocols for Mobile Ad Hoc Networks

    CERN Document Server

    Meghanathan, Natarajan

    2010-01-01

    The high-level contribution of this paper is a simulation-based detailed performance comparison of three different classes of routing protocols for mobile ad hoc networks: stability-based routing, power-aware routing and load-balanced routing. We choose the Flow-Oriented Routing protocol (FORP), the traffic interference based Load Balancing Routing (LBR) protocol and Min-Max Battery Cost Routing (MMBCR) as representatives of the stability-based routing, load-balancing and power-aware routing protocols respectively. Among the three routing protocols, FORP incurs the least number of route transitions; while LBR incurs the smallest hop count and lowest end-to-end delay per data packet. Energy consumed per node is the least for MMBCR, closely followed by LBR. MMBCR is the most fair in terms of node usage and hence it incurs the largest time for first node failure. FORP tends to repeatedly use nodes lying on the stable path and hence is the most unfair of the three routing protocols and it incurs the smallest valu...

  6. A Survey of Fading Models for Mobile Radio Channel Characterization

    Directory of Open Access Journals (Sweden)

    L. D. Arya

    2010-02-01

    Full Text Available Future 3G and 4G mobile communication systems will be required to support wide range of data rates and quality of service matrix. For the efficient design of data link and transport protocols system designer needs knowledge of the statistical properties of physicallayer. Studies have shown that without proper characterization of the channel, blind application of existing protocols and transmission policy may results in disastrous performance unless proper measures are not being taken. Channel characterization also helps in llocation of resources, selection of transmission policy andprotocols. A feasible measure is to have an accurate and thoroughly reproducible optimum channel model which can mimic the mobile radio channel in diversities of fading error environments. Objective of channel model is to supply proper outputs for designing of upper layer protocol in such a fashion as if it were running on the actualphysical layer. The model should fit very well to the measured data and should easily handle analytically. Various approaches for characterization of fading mobile channels have appeared in iterature over last five decades. This article surveys the fading channel models for proper characterization of the radio channel andprovides approaches to classify the existing channel models. The paper also presents the contribution made by these channel models with their assumptions, suitability, applications, shortcomingsand further improvement issues. In present environment Markov Models are best suited for characterization of the fading radio channel. Inthese models radio channel is presented in terms of fading states and modeled as stochastic process. A proper constructed channel model may be valuable means to enhance the reliability and capacity of future mobile radio channel.

  7. Dynamic response of scale models subjected to impact loading

    Science.gov (United States)

    Hillsdon, Graham K.

    1997-05-01

    Presented with the problem of possible failure of large structures due to dynamic loading, and the cost of staging full scale tests. The Oxford University's Department of Engineering Science, supported by British Gas and Rolls Royce, has been scale modeling these events experimentally. The paper looks at two areas of research: (1) The structural integrity of a particular type of Liquified Natural Gas Storage Tank, and its vulnerability to blast loading. (2) The ability of Large Aero Engine Fan blades to withstand impacts associated with birds, stones, ice etc.

  8. Capacitive top-loading of a mobile phone antenna for size reduction

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2004-01-01

    Capacitive top loading for size reduction of the Planar Inverted F Antenna (PIFA) is presented in this paper. A measured 39% reduction from 1.8 to 1.22 GHz of the resonant frequency is accomplished by using a 1.1 pF distributed capacitor. The simulated –6 dB bandwidth is 9% with a peak radiation...

  9. Averaged hole mobility model of biaxially strained Si

    Institute of Scientific and Technical Information of China (English)

    Song Jianjun; Zhu He; Yang Jinyong; Zhang Heming; Xuan Rongxi; Hu Huiyong

    2013-01-01

    We aim to establisha model of the averaged hole mobility of strained Si grown on (001),(101),and (111) relaxed Si1-xGex substrates.The results obtained from our calculation show that their hole mobility values corresponding to strained Si (001),(101) and (111) increase by at most about three,two and one times,respectively,in comparison with the unstrained Si.The results can provide a valuable reference to the understanding and design of strained Si-based device physics.

  10. Modeling the consequences of tongue surgery on tongue mobility

    CERN Document Server

    Buchaillard, Stéphanie; Perrier, Pascal; Payan, Yohan

    2007-01-01

    This paper presents the current achievements of a long term project aiming at predicting and assessing the impact of tongue and mouth floor surgery on tongue mobility. The ultimate objective of this project is the design of a software with which surgeons should be able (1) to design a 3D biomechanical model of the tongue and of the mouth floor that matches the anatomical characteristics of each patient specific oral cavity, (2) to simulate the anatomical changes induced by the surgery and the possible reconstruction, and (3) to quantitatively predict and assess the consequences of these anatomical changes on tongue mobility and speech production after surgery.

  11. Modeling the Responses of TSM Resonators under Various Loading Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bandey, H.L.; Cernosek, R.W.; Hillman, A.R.; Martin, S.J.

    1998-12-04

    We develop a general model that describes the electrical responses of thickness shear mode resonators subject to a variety of surface loadkgs. The model incorporates a physically diverse set of single component loadings, including rigid solids, viscoelastic media and fluids (Newtonian or Maxwellian). The model allows any number of these components to be combined in any configuration. Such multiple loadings are representative of a variety of physical situations encountered in electrochemical and other liquid phase applications, as well as gas phase applications. In the general case, the response of the composite is not a linear combination of the individual component responses. We discuss application of the model in a qualitative diagnostic fashion, to gain insight into the nature of the interracial structure, and in a quantitative fashion, to extract appropriate physical parameters, such as liquid viscosity and density and polymer shear moduli.

  12. Vortex Lattice UXO Mobility Model Integration

    Science.gov (United States)

    2015-03-01

    16  2.2  ADVANTAGES AND LIMITATIONS OF THE TECHNOLOGY .................... 17  3.0  PERFORMANCE OBJECTIVES...2  Figure 2. SCM for UXO showing the UXO MM analysis (lower left) as part of source quantification efforts...ordnance” (Johnson et al., 2002). A site conceptual model ( SCM ) was developed under this program and is shown schematically in Figure 2. After

  13. COMPARISON BETWEEN MODELS FOR CALCULATION OF INDUSTRIAL HOT ROLLING LOADS

    OpenAIRE

    Antonio Augusto Gorni; Marcos Roberto Soares da Silva

    2012-01-01

    An evaluation is made about the precision of hot strip rolling mill loads at the F1 stand calculated according to the theoretical models of Orowan, Sims, Alexander-Ford, Orowan-Pascoe, Ekelund and Tselikov in comparison to real values got for carbon-manganese steels. In the deterministic approach, without any fit of the calculated values to real data, Orowan, Sims and Alexander-Models show best levels of precision, as expected from the information got in the literature. However, i...

  14. Crack simulation models in variable amplitude loading - a review

    Directory of Open Access Journals (Sweden)

    Luiz Carlos H. Ricardo

    2016-02-01

    Full Text Available This work presents a review of crack propagation simulation models considering plane stress and plane strain conditions. It is presented also a chronological different methodologies used to perform the crack advance by finite element method. Some procedures used to edit variable spectrum loading and the effects during crack propagation processes, like retardation, in the fatigue life of the structures are discussed. Based on this work there is no consensus in the scientific community to determine the best way to simulate crack propagation under variable spectrum loading due the combination of metallurgic and mechanical factors regarding, for example, how to select and edit the representative spectrum loading to be used in the crack propagation simulation.

  15. Probabilistic Models and Process Calculi for Mobile Ad Hoc Networks

    DEFF Research Database (Denmark)

    Song, Lei

    Due to the wide use of communicating mobile devices, mobile ad hoc networks (MANETs) have gained in popularity in recent years. In order that the devices communicate properly, many protocols have been proposed working at different levels. Devices in an MANET are not stationary but may keep moving......, thus the network topology may undergo constant changes. Moreover the devices in an MANET are loosely connected not depending on pre-installed infrastructure or central control components, they exchange messages via wireless connections which are less reliable compared to wired connections. Therefore...... issues in MANETs e.g. mobility and unreliable connections. Specially speaking, 1. We first propose a discrete probabilistic process calculus with which we can model in an MANET that the wireless connection is not reliable, and the network topology may undergo changes. We equip each wireless connection...

  16. Modelling human mobility patterns using photographic data shared online.

    Science.gov (United States)

    Barchiesi, Daniele; Preis, Tobias; Bishop, Steven; Moat, Helen Susannah

    2015-08-01

    Humans are inherently mobile creatures. The way we move around our environment has consequences for a wide range of problems, including the design of efficient transportation systems and the planning of urban areas. Here, we gather data about the position in space and time of about 16 000 individuals who uploaded geo-tagged images from locations within the UK to the Flickr photo-sharing website. Inspired by the theory of Lévy flights, which has previously been used to describe the statistical properties of human mobility, we design a machine learning algorithm to infer the probability of finding people in geographical locations and the probability of movement between pairs of locations. Our findings are in general agreement with official figures in the UK and on travel flows between pairs of major cities, suggesting that online data sources may be used to quantify and model large-scale human mobility patterns.

  17. Coarse grained model for calculating the ion mobility of hydrocarbons

    Science.gov (United States)

    Kuroboshi, Y.; Takemura, K.

    2016-12-01

    Hydrocarbons are widely used as insulating compounds. However, their fundamental characteristics in conduction phenomena are not completely understood. A great deal of effort is required to determine reasonable ionic behavior from experiments because of their complicated procedures and tight controls of the temperature and the purity of the liquids. In order to understand the conduction phenomena, we have theoretically calculated the ion mobilities of hydrocarbons and investigated their characteristics using the coarse grained model in molecular dynamics simulations. We assumed a molecule of hydrocarbons to be a bead and simulated its dependence on the viscosity, electric field, and temperature. Furthermore, we verified the suitability of the conformation, scale size, and long-range interactions for the ion mobility. The results of the simulations show that the ion mobility values agree reasonably well with the values from Walden's rule and depend on the viscosity but not on the electric field. The ion mobility and self-diffusion coefficient exponentially increase with increasing temperature, while the activation energy decreases with increasing molecular size. These values and characteristics of the ion mobility are in reasonable agreement with experimental results. In the future, we can understand not only the ion mobilies of hydrocarbons in conduction, but also we can predict general phenomena in electrochemistry with molecular dynamics simulations.

  18. Interpretation and mapping of geological features using mobile devices for 3D outcrop modelling

    Science.gov (United States)

    Buckley, Simon J.; Kehl, Christian; Mullins, James R.; Howell, John A.

    2016-04-01

    Advances in 3D digital geometric characterisation have resulted in widespread adoption in recent years, with photorealistic models utilised for interpretation, quantitative and qualitative analysis, as well as education, in an increasingly diverse range of geoscience applications. Topographic models created using lidar and photogrammetry, optionally combined with imagery from sensors such as hyperspectral and thermal cameras, are now becoming commonplace in geoscientific research. Mobile devices (tablets and smartphones) are maturing rapidly to become powerful field computers capable of displaying and interpreting 3D models directly in the field. With increasingly high-quality digital image capture, combined with on-board sensor pose estimation, mobile devices are, in addition, a source of primary data, which can be employed to enhance existing geological models. Adding supplementary image textures and 2D annotations to photorealistic models is therefore a desirable next step to complement conventional field geoscience. This contribution reports on research into field-based interpretation and conceptual sketching on images and photorealistic models on mobile devices, motivated by the desire to utilise digital outcrop models to generate high quality training images (TIs) for multipoint statistics (MPS) property modelling. Representative training images define sedimentological concepts and spatial relationships between elements in the system, which are subsequently modelled using artificial learning to populate geocellular models. Photorealistic outcrop models are underused sources of quantitative and qualitative information for generating TIs, explored further in this research by linking field and office workflows through the mobile device. Existing textured models are loaded to the mobile device, allowing rendering in a 3D environment. Because interpretation in 2D is more familiar and comfortable for users, the developed application allows new images to be captured

  19. Forces Mobilization Model (FORCEMOB): Unclassified Training Tutorial

    Science.gov (United States)

    2015-08-01

    industrial output occur 6. Models the use of emergency investment to redress shortfalls; computes investment demand iv Table 1. FORCEMOB Input...use of emergency investment to redress shortfalls and compute emergency investment demand  This section will give a high level overview of how...this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data

  20. Validation of ice loads predicted from meteorological models

    Energy Technology Data Exchange (ETDEWEB)

    Veal, A.; Skea, A. [UK Met Office, Exeter, England (United Kingdom); Wareing, B. [Brian Wareing Tech Ltd., England (United Kingdom)

    2005-07-01

    Results of a field trial conducted on 2 Gerber PVM-100 instruments at Deadwater Fell test site in the United Kingdom were presented. The trials were conducted to assess whether the instruments were capable of measuring the liquid water content of the air, as well as to validate an ice model in terms of accretion rates on different sized conductors. Ambient air temperature, wind speed and direction were monitored at the Deadwater Fell weather station along with load cell values. Time lapse video recorders and a web camera system were used to view the performance of the conductors in varying weather conditions. All data was collected and stored at the site. It was anticipated that output from the instruments could be related to the conditions under which overhead line conductors suffer from ice loads, and help to revise weather maps which have proved to be incompatible with utility experience and the lifetimes achieved by overhead line designs. The data provided from the Deadwater work included logged data from the Gerbers, weather data and load data from a 10 mm diameter aluminium alloy conductor. When the combination of temperature, wind direction and Gerber output indicated icing conditions, they were confirmed by the conductor's load cell data. The tests confirmed the validity of the Gerber instruments to predict the occurrence of icing conditions, when combined with other meteorological data. It was concluded that the instruments may aid in optimized prediction methods for ice loads and icing events. 2 refs., 4 figs.

  1. Constrained motion model of mobile robots and its applications.

    Science.gov (United States)

    Zhang, Fei; Xi, Yugeng; Lin, Zongli; Chen, Weidong

    2009-06-01

    Target detecting and dynamic coverage are fundamental tasks in mobile robotics and represent two important features of mobile robots: mobility and perceptivity. This paper establishes the constrained motion model and sensor model of a mobile robot to represent these two features and defines the k -step reachable region to describe the states that the robot may reach. We show that the calculation of the k-step reachable region can be reduced from that of 2(k) reachable regions with the fixed motion styles to k + 1 such regions and provide an algorithm for its calculation. Based on the constrained motion model and the k -step reachable region, the problems associated with target detecting and dynamic coverage are formulated and solved. For target detecting, the k-step detectable region is used to describe the area that the robot may detect, and an algorithm for detecting a target and planning the optimal path is proposed. For dynamic coverage, the k-step detected region is used to represent the area that the robot has detected during its motion, and the dynamic-coverage strategy and algorithm are proposed. Simulation results demonstrate the efficiency of the coverage algorithm in both convex and concave environments.

  2. Parameter Selection and Performance Analysis of Mobile Terminal Models Based on Unity3D

    Institute of Scientific and Technical Information of China (English)

    KONG Li-feng; ZHAO Hai-ying; XU Guang-mei

    2014-01-01

    Mobile platform is now widely seen as a promising multimedia service with a favorable user group and market prospect. To study the influence of mobile terminal models on the quality of scene roaming, a parameter setting platform of mobile terminal models is established to select the parameter selection and performance index on different mobile platforms in this paper. This test platform is established based on model optimality principle, analyzing the performance curve of mobile terminals in different scene models and then deducing the external parameter of model establishment. Simulation results prove that the established test platform is able to analyze the parameter and performance matching list of a mobile terminal model.

  3. Differences in Anatomy and Kinematics in Asian and Caucasian TKA Patients: Influence on Implant Positioning and Subsequent Loading Conditions in Mobile Bearing Knees

    Directory of Open Access Journals (Sweden)

    Allan Maas

    2014-01-01

    Full Text Available The objective of our study was to determine the mechanical stress conditions under tibiofemoral loading with an overlay of knee kinematics in deep flexion on two different mobile bearing designs in comparison to in vivo failure modes. This study investigates the seldom but severe complication of fatigue failure of polyethylene components at mobile bearing total knee arthroplasty designs. Assuming a combination of a floor-based lifestyle and tibial malrotation as a possible reason for a higher failure rate in Asian countries we developed a simplified finite element model considering a tibiofemoral roll-back angle of 22° and the range of rotational motion of a clinically established floating platform design (e.motion FP at a knee flexion angle of 120° in order to compare our results to failure modes found in retrieved implants. Compared to the failure mode observed in the clinical retrievals the locations of the occurring stress maxima as well as the tensile stress distribution show analogies. From our observations, we conclude that the newly introduced finite element model with an overlay of deep knee flexion (lateral roll-back and considerable internally rotated tibia implant positioning is an appropriate analysis for knee design optimizations and a suitable method to predict clinical failure modes.

  4. Improved Security Models & Protocols in Online Mobile Business Financial Transactions

    OpenAIRE

    Sreeramana Aithal

    2017-01-01

    Chapter I : Introduction to Mobile Business and Mobile Banking Chapter II : Review of Literature on Mobile Business Technology, Mobile Banking Services & Security Chapter III : Research Objectives and Methodology Chapter IV : Results and Discussion Chapter V : Summary and Conclusions Bibliography

  5. Mobilization

    Science.gov (United States)

    1987-01-01

    istic and romantic emotionalism that typifies this genre. Longino, James C., et al. “A Study of World War Procurement and Industrial Mobilization...States. Harrisburg, PA: Military Service Publishing Co., 1941. CARL 355.22 J72b. Written in rough prose , this World War II era document explains the

  6. FEM modelling of soil behaviour under compressive loads

    Science.gov (United States)

    Ungureanu, N.; Vlăduţ, V.; Biriş, S. Şt

    2017-01-01

    Artificial compaction is one of the most dangerous forms of degradation of agricultural soil. Recognized as a phenomenon with multiple negative effects in terms of environment and agricultural production, soil compaction is strongly influenced by the size of external load, soil moisture, size and shape of footprint area, soil type and number of passes. Knowledge of soil behavior under compressive loads is important in order to prevent or minimize soil compaction. In this paper were developed, by means of the Finite Element Method, various models of soil behavior during the artificial compaction produced by the wheel of an agricultural trailer. Simulations were performed on two types of soil (cohesive and non-cohesive) with known characteristics. By applying two loads (4.5 kN and 21 kN) in footprints of different sizes, were obtained the models of the distributions of stresses occuring in the two types of soil. Simulation results showed that soil stresses increase with increasing wheel load and vary with soil type.

  7. Dynamic modeling and simulation for nonholonomic welding mobile robot

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the Newton-Euler method, the dynamic behaviors of the left and right driving wheels and the robot body for the welding mobile robot were derived. In order to realize the combination control of body turning and slider adjustment, the dynamic behaviors of sliders were also investigated. As a result, a systematic and complete dynamic model for the welding mobile robot was constructed. In order to verify the effectiveness of the above model, a sliding mode tracking control method was proposed and simulated, the lateral error stabilizes between -0.2 mm and +0.2 mm, and the total distance of travel for the slider is consistently within ±2 mm. The simulation results verify the effectiveness of the established dynamic model and also show that the seam tracking controller based on the dynamic model has excellent performance in terms of stability and robustness. Furthermore, the model is found to be very suitable for practical applications of the welding mobile robot.

  8. Load optimal design for a primary test stand facility based on a zero-dimensional load model

    Institute of Scientific and Technical Information of China (English)

    Zhao Hai-Long; Deng Jian-Jun; Wang Gang-Hua; Zou Wen-Kang

    2011-01-01

    In order to couple the numerical simulation of a primary test stand driver with an optimal load design,a zero dimensional wire array load model is designed based on the Saturn load model using PSPICE,which is an upgraded version of the Simulation Program with Integrated Circuit Emphasis (SPICE) designed by the ORCAD Corporation to perform circuit simulations.This paper calculates different load parameters and discusses factors influencing the driving current curve.With appropriate driving current curves chosen,further magneto-hydrodynamic calculations are carried out and discussed to provide the best results for experiments.The suggested optimal load parameters play an important role in experimental load design.

  9. Comparison of Building Energy Modeling Programs: Building Loads

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Dandan [Tsinghua Univ., Beijing (China); Hong, Tianzhen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yan, Da [Tsinghua Univ., Beijing (China); Wang, Chuang [Tsinghua Univ., Beijing (China)

    2012-06-01

    This technical report presented the methodologies, processes, and results of comparing three Building Energy Modeling Programs (BEMPs) for load calculations: EnergyPlus, DeST and DOE-2.1E. This joint effort, between Lawrence Berkeley National Laboratory, USA and Tsinghua University, China, was part of research projects under the US-China Clean Energy Research Center on Building Energy Efficiency (CERC-BEE). Energy Foundation, an industrial partner of CERC-BEE, was the co-sponsor of this study work. It is widely known that large discrepancies in simulation results can exist between different BEMPs. The result is a lack of confidence in building simulation amongst many users and stakeholders. In the fields of building energy code development and energy labeling programs where building simulation plays a key role, there are also confusing and misleading claims that some BEMPs are better than others. In order to address these problems, it is essential to identify and understand differences between widely-used BEMPs, and the impact of these differences on load simulation results, by detailed comparisons of these BEMPs from source code to results. The primary goal of this work was to research methods and processes that would allow a thorough scientific comparison of the BEMPs. The secondary goal was to provide a list of strengths and weaknesses for each BEMP, based on in-depth understandings of their modeling capabilities, mathematical algorithms, advantages and limitations. This is to guide the use of BEMPs in the design and retrofit of buildings, especially to support China’s building energy standard development and energy labeling program. The research findings could also serve as a good reference to improve the modeling capabilities and applications of the three BEMPs. The methodologies, processes, and analyses employed in the comparison work could also be used to compare other programs. The load calculation method of each program was analyzed and compared to

  10. Innovative research of AD HOC network mobility model

    Science.gov (United States)

    Chen, Xin

    2017-08-01

    It is difficult for researchers of AD HOC network to conduct actual deployment during experimental stage as the network topology is changeable and location of nodes is unfixed. Thus simulation still remains the main research method of the network. Mobility model is an important component of AD HOC network simulation. It is used to describe the movement pattern of nodes in AD HOC network (including location and velocity, etc.) and decides the movement trail of nodes, playing as the abstraction of the movement modes of nodes. Therefore, mobility model which simulates node movement is an important foundation for simulation research. In AD HOC network research, mobility model shall reflect the movement law of nodes as truly as possible. In this paper, node generally refers to the wireless equipment people carry. The main research contents include how nodes avoid obstacles during movement process and the impacts of obstacles on the mutual relation among nodes, based on which a Node Self Avoiding Obstacle, i.e. NASO model is established in AD HOC network.

  11. A Nonlocal Model for Carbon Nanotubes under Axial Loads

    Directory of Open Access Journals (Sweden)

    Raffaele Barretta

    2013-01-01

    Full Text Available Various beam theories are formulated in literature using the nonlocal differential constitutive relation proposed by Eringen. A new variational framework is derived in the present paper by following a consistent thermodynamic approach based on a nonlocal constitutive law of gradient-type. Contrary to the results obtained by Eringen, the new model exhibits the nonlocality effect also for constant axial load distributions. The treatment can be adopted to get new benchmarks for numerical analyses.

  12. Optimisation models and solution methods for load management

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Stig-Inge [Linkoeping Univ. (Sweden). Div. of Wood Science and Technology; Roennqvist, Mikael; Claesson, Marcus [Linkoeping Univ. (Sweden). Div. of Optimisation

    2001-02-01

    The electricity market in Sweden has changed during recent years. Electricity for industrial use can nowadays be purchased from a number of competing electricity suppliers. Hence, the price for each kilowatt-hour is significantly lower than just two years ago and the interest for electricity conservation measures has declined. Part of the electricity tariff is, however, almost the same as before, i.e. the demand cost expressed in Swedish Kronor, SEK, for each kilowatt. This has put focus on load management measures in order to decrease this specific cost. Saving one kWh might lead to monetary savings between 0.22 to 914 SEK and this paper shows how to save only those kWh which really save money. A load management system has been installed in a small carpentry factory and the device can turn off equipment due to a certain priority and for a number of minutes each hour. The question is now, what level on the electricity load is optimal in a strict mathematical sense, i.e. how many kW should be set in the load management computer in order to get the best profitability? In this paper we develop a mathematical model which can be used both as a tool to find a best profitable subscription level and as a tool to control the turn of choices. Numerical results from a case study are presented.

  13. Authentication Model Based Bluetooth-enabled Mobile Phone

    Directory of Open Access Journals (Sweden)

    Rania Abdelhameed

    2005-01-01

    Full Text Available Authentication is a mechanism to establish proof of identities, the authentication process ensure that who a particular user is. Current PC, laptop user authentication systems are always done once and hold until it explicitly revoked by the user, or asking the user to frequently reestablish his identity which encouraging him to disable authentication. Zero-Interaction Authentication (ZIA provides solution to this problem. In ZIA, a user wears a small authentication token that communicates with a laptop over a short-range, wireless link. ZIA combine authentication with a file encryption. Here we proposed a Laptop-user Authentication Based Mobile phone (LABM, in our model of authentication, a user uses his Bluetooth-enabled mobile phone, which work as an authentication token that provides the authentication for laptop over a Bluetooth wireless link, in the concept of transient authentication with out combining it with encryption file system. The user authenticate to the mobile phone infrequently. In turn, the mobile phone continuously authenticates to the laptop by means of the short-range, wireless link.

  14. A Novel Model for Cloud Based Mobile Learning System

    Directory of Open Access Journals (Sweden)

    Areej Omar Baalghusun

    2014-12-01

    Full Text Available Mobile learning (M-learning becomes revolutionary way to educate the world with the mass advancement in information and communications technology (ICT. It is difficult to deal with m-learning due to increasing number of users, services, education contents and resources and modes to deploy. Cloud computing, with its dynamic scalability and virtualized resources usage, is widely deployed for several applications in many organizations. It has a significant impact in the educational and learning environment. This paper presents a new model for mobile learning system in cloud computing environment that is enriched with high performance computing (HPC and graphical processing unit (GPU cluster infrastructure. This model aggregates the power with new technologies to implement M-leaning process more effective with high performance and quick response.

  15. Mutual Interference Models for CDMA Mobile Communication Networks

    OpenAIRE

    Hrudkay, K.; Wieser, V.

    2002-01-01

    Nowadays we are witnesses of a huge development one of the most progressive communication technology - mobile networks. The main problem in these networks is an elimination of the mutual interference, which, mainly in non-orthogonal CDMA networks, is the principal obstacle for reaching high transmission rates The aim of this contribution is to give simplified view to mutual interference models for orthogonal and non-orthogonal CDMA networks. The contribution is intended mainly for PhD. studen...

  16. Sensor Fusion Based Model for Collision Free Mobile Robot Navigation

    Directory of Open Access Journals (Sweden)

    Marwah Almasri

    2015-12-01

    Full Text Available Autonomous mobile robots have become a very popular and interesting topic in the last decade. Each of them are equipped with various types of sensors such as GPS, camera, infrared and ultrasonic sensors. These sensors are used to observe the surrounding environment. However, these sensors sometimes fail and have inaccurate readings. Therefore, the integration of sensor fusion will help to solve this dilemma and enhance the overall performance. This paper presents a collision free mobile robot navigation based on the fuzzy logic fusion model. Eight distance sensors and a range finder camera are used for the collision avoidance approach where three ground sensors are used for the line or path following approach. The fuzzy system is composed of nine inputs which are the eight distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot’s wheels, and 24 fuzzy rules for the robot’s movement. Webots Pro simulator is used for modeling the environment and the robot. The proposed methodology, which includes the collision avoidance based on fuzzy logic fusion model and line following robot, has been implemented and tested through simulation and real time experiments. Various scenarios have been presented with static and dynamic obstacles using one robot and two robots while avoiding obstacles in different shapes and sizes.

  17. Sensor Fusion Based Model for Collision Free Mobile Robot Navigation.

    Science.gov (United States)

    Almasri, Marwah; Elleithy, Khaled; Alajlan, Abrar

    2015-12-26

    Autonomous mobile robots have become a very popular and interesting topic in the last decade. Each of them are equipped with various types of sensors such as GPS, camera, infrared and ultrasonic sensors. These sensors are used to observe the surrounding environment. However, these sensors sometimes fail and have inaccurate readings. Therefore, the integration of sensor fusion will help to solve this dilemma and enhance the overall performance. This paper presents a collision free mobile robot navigation based on the fuzzy logic fusion model. Eight distance sensors and a range finder camera are used for the collision avoidance approach where three ground sensors are used for the line or path following approach. The fuzzy system is composed of nine inputs which are the eight distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot's wheels, and 24 fuzzy rules for the robot's movement. Webots Pro simulator is used for modeling the environment and the robot. The proposed methodology, which includes the collision avoidance based on fuzzy logic fusion model and line following robot, has been implemented and tested through simulation and real time experiments. Various scenarios have been presented with static and dynamic obstacles using one robot and two robots while avoiding obstacles in different shapes and sizes.

  18. Planetary Gear Profile Modification Design Based on Load Sharing Modelling

    Institute of Scientific and Technical Information of China (English)

    IGLESIAS Miguel; FERNÁNDEZ DEL RINCÓN Alfonso; DE-JUAN Ana Magdalena; GARCIA Pablo; DIEZ Alberto; VIADERO Fernando

    2015-01-01

    In order to satisfy the increasing demand on high performance planetary transmissions, an important line of research is focused on the understanding of some of the underlying phenomena involved in this mechanical system. Through the development of models capable of reproduce the system behavior, research in this area contributes to improve gear transmission insight, helping developing better maintenance practices and more efficient design processes. A planetary gear model used for the design of profile modifications ratio based on the levelling of the load sharing ratio is presented. The gear profile geometry definition, following a vectorial approach that mimics the real cutting process of gears, is thoroughly described. Teeth undercutting and hypotrochoid definition are implicitly considered, and a procedure for the incorporation of a rounding arc at the tooth tip in order to deal with corner contacts is described. A procedure for the modeling of profile deviations is presented, which can be used for the introduction of both manufacturing errors and designed profile modifications. An easy and flexible implementation of the profile deviation within the planetary model is accomplished based on the geometric overlapping. The contact force calculation and dynamic implementation used in the model are also introduced, and parameters from a real transmission for agricultural applications are presented for the application example. A set of reliefs is designed based on the levelling of the load sharing ratio for the example transmission, and finally some other important dynamic factors of the transmission are analyzed to assess the changes in the dynamic behavior with respect to the non-modified case. Thus, the main innovative aspect of the proposed planetary transmission model is the capacity of providing a simulated load sharing ratio which serves as design variable for the calculation of the tooth profile modifications.

  19. A Transport Model of Mobile Agent Based on Secure Hybrid Encryption

    Institute of Scientific and Technical Information of China (English)

    SUNZhixin; CHENZhixian; WANGRuchuan

    2005-01-01

    The solution of security problems of mobile agents is a key issue, which will decide whether mobile agents can be widely used. The paper analyzes main security problems, which currently are confronted with mobile agent systems and existing protection solutions. And then the paper presents a Security Transport model of mobile agents based on a hybrid encryption algorithm (TMSHE).Meanwhile, it expatiates on implementation of the algorithm. The algorithm of TMSHE model mainly consists of two parts, i.e., employing a hybrid encryption algorithm to encrypt mobile agents and using Transport layer security (TLS) to encrypt communication channel. Mobile agents by hybrid encryption move through communication channels, which are encrypted by TLS. The simulation results indicate that the model can protect mobile agents' security effectively, and consequently the security and steadiness of the whole mobile agent system are also improved. The model has succeeded in getting application in a prototypesystem- Intrusion detection system based on mobile agents.

  20. Transparent settlement model between mobile network operator and mobile voice over Internet protocol operator

    Directory of Open Access Journals (Sweden)

    Luzango Pangani Mfupe

    2014-12-01

    Full Text Available Advances in technology have enabled network-less mobile voice over internet protocol operator (MVoIPO to offer data services (i.e. voice, text and video to mobile network operator's (MNO's subscribers through an application enabled on subscriber's user equipment using MNO's packet-based cellular network infrastructure. However, this raises the problem of how to handle interconnection settlements between the two types of operators, particularly how to deal with users who now have the ability to make ‘free’ on-net MVoIP calls among themselves within the MNO's network. This study proposes a service level agreement-based transparent settlement model (TSM to solve this problem. The model is based on concepts of achievement and reward, not violation and punishment. The TSM calculates the MVoIPO's throughput distribution by monitoring the variations of peaks and troughs at the edge of a network. This facilitates the determination of conformance and non-conformance levels to the pre-set throughput thresholds and, subsequently, the issuing of compensation to the MVoIPO by the MNO as a result of generating an economically acceptable volume of data traffic.

  1. Comparison of multiaxial fatigue damage models under variable amplitude loading

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong; Shang, De Guang; Tian, Yu Jie [Beijing Univ. of Technology, Beijing (China); Liu, Jian Zhong [Beijing Institute of Aeronautical Materials, Beijing (China)

    2012-11-15

    Based on the cycle counting method of Wang and Brown and on the linear accumulation damage rule of Miner, four multiaxial fatigue damage models without any weight factors proposed by Pan et al., Varvani Farahani, Shang and Wang, and Shang et al. are used to compute fatigue damage. The procedure is evaluated using the low cycle fatigue experimental data of 7050 T7451 aluminum alloy and En15R steel under tension/torsion variable amplitude loading. The results reveal that the procedure is convenient for engineering design and application, and that the four multiaxial fatigue damage models provide good life estimates.

  2. Quasistatic Modeling of Concentric Tube Robots with External Loads.

    Science.gov (United States)

    Lock, Jesse; Laing, Genevieve; Mahvash, Mohsen; Dupont, Pierre E

    2010-12-03

    Concentric tube robots are a subset of continuum robots constructed by combining pre-curved elastic tubes. As the tubes are rotated and translated with respect to each other, their curvatures interact elastically, enabling control of the robot's tip configuration as well as the curvature along its length. This technology is projected to be useful in many types of minimally invasive medical procedures. Because these robots are flexible by design, they deflect considerably when applying forces to the external environment. Thus, in contrast to rigid-link robots, their kinematic and static force models are coupled. This paper derives a multi-tube quasistatic model that relates tube rotations and translations together with externally applied loads to robot shape and tip configuration. The model can be applied in robot design, procedure planning as well as control. For validation, the multi-tube model is compared experimentally to a computationally-efficient single-tube approximate model.

  3. Loading models for electric vehicles; Lademodelle fuer Elektrofahrzeuge

    Energy Technology Data Exchange (ETDEWEB)

    Mezger, Tomas [Forschungsstelle fuer Energiewirtschaft e.V., Muenchen (Germany)

    2011-07-01

    About 5 to 7 million electric vehicles have adverse effects on the electricity grid. Thus, there is a need to develop optimized loading concepts, which generate an added value both for the energy industry as well as for the vehicle owners. A two-stage analysis method is used for this. Within the first step it is examined, how defined fleet of electric vehicles can be loaded optimally with electricity taking into account the specific vehicle usage. In the second step, the charging models are again evaluated from a user perspective. The impact of the driving behavior and charge characteristics on the aging of the battery are considered specifically. Charging possibilities are identified in order to increase the battery life.

  4. Numerical modelling of electromagnetic loads on fusion device structures

    Science.gov (United States)

    Bettini, Paolo; Furno Palumbo, Maurizio; Specogna, Ruben

    2014-03-01

    In magnetic confinement fusion devices, during abnormal operations (disruptions) the plasma begins to move rapidly towards the vessel wall in a vertical displacement event (VDE), producing plasma current asymmetries, vessel eddy currents and open field line halo currents, each of which can exert potentially damaging forces upon the vessel and in-vessel components. This paper presents a methodology to estimate electromagnetic loads, on three-dimensional conductive structures surrounding the plasma, which arise from the interaction of halo-currents associated to VDEs with a magnetic field of the order of some Tesla needed for plasma confinement. Lorentz forces, calculated by complementary formulations, are used as constraining loads in a linear static structural analysis carried out on a detailed model of the mechanical structures of a representative machine.

  5. Mechanical Model for Dynamic Behavior of Concrete Under Impact Loading

    Science.gov (United States)

    Sun, Yuanxiang

    Concrete is a geo-material which is used substantively in the civil building and military safeguard. One coupled model of damage and plasticity to describe the complex behavior of concrete subjected to impact loading is proposed in this research work. The concrete is assumed as homogeneous continuum with pre-existing micro-cracks and micro-voids. Damage to concrete is caused due to micro-crack nucleation, growth and coalescence, and defined as the probability of fracture at a given crack density. It induces a decrease of strength and stiffness of concrete. Compaction of concrete is physically a collapse of the material voids. It produces the plastic strain in the concrete and, at the same time, an increase of the bulk modulus. In terms of crack growth model, micro-cracks are activated, and begin to propagate gradually. When crack density reaches a critical value, concrete takes place the smashing destroy. The model parameters for mortar are determined using plate impact experiment with uni-axial strain state. Comparison with the test results shows that the proposed model can give consistent prediction of the impact behavior of concrete. The proposed model may be used to design and analysis of concrete structures under impact and shock loading. This work is supported by State Key Laboratory of Explosion science and Technology, Beijing Institute of Technology (YBKT14-02).

  6. Cortical and trabecular bone adaptation to incremental load magnitudes using the mouse tibial axial compression loading model.

    Science.gov (United States)

    Weatherholt, Alyssa M; Fuchs, Robyn K; Warden, Stuart J

    2013-01-01

    The mouse tibial axial compression loading model has recently been described to allow simultaneous exploration of cortical and trabecular bone adaptation within the same loaded element. However, the model frequently induces cortical woven bone formation and has produced inconsistent results with regards to trabecular bone adaptation. The aim of this study was to investigate bone adaptation to incremental load magnitudes using the mouse tibial axial compression loading model, with the ultimate goal of revealing a load that simultaneously induced lamellar cortical and trabecular bone adaptation. Adult (16 weeks old) female C57BL/6 mice were randomly divided into three load magnitude groups (5, 7 and 9N), and had their right tibia axially loaded using a continuous 2-Hz haversine waveform for 360 cycles/day, 3 days/week for 4 consecutive weeks. In vivo peripheral quantitative computed tomography was used to longitudinally assess midshaft tibia cortical bone adaptation, while ex vivo micro-computed tomography and histomorphometry were used to assess both midshaft tibia cortical and proximal tibia trabecular bone adaptation. A dose response to loading magnitude was observed within cortical bone, with increasing load magnitude inducing increasing levels of lamellar cortical bone adaptation within the upper two thirds of the tibial diaphysis. Greatest cortical bone adaptation was observed at the midshaft where there was a 42% increase in estimated mechanical properties (polar moment of inertia) in the highest (9N) load group. A dose response to load magnitude was not clearly evident within trabecular bone, with only the highest load (9N) being able to induce measureable adaptation (31% increase in trabecular bone volume fraction at the proximal tibia). The ultimate finding was that a load of 9N (engendering a tensile strain of 1833 με on medial surface of the midshaft tibia) was able to simultaneously induce measurable lamellar cortical and trabecular bone adaptation

  7. On the Influence of Weather Forecast Errors in Short-Term Load Forecasting Models

    OpenAIRE

    Fay, D; Ringwood, John; Condon, M.

    2004-01-01

    Weather information is an important factor in load forecasting models. This weather information usually takes the form of actual weather readings. However, online operation of load forecasting models requires the use of weather forecasts, with associated weather forecast errors. A technique is proposed to model weather forecast errors to reflect current accuracy. A load forecasting model is then proposed which combines the forecasts of several load forecasting models. This approach allows the...

  8. A Mobile Commerce Model for Automobile Rescue Services

    OpenAIRE

    Zhang, Liyi; Liu, Qihua

    2010-01-01

    With the advance of mobile commerce technology, mobile businesses rapidly gain its popularity. Many factors, including LBS (Location-Based Services) SMS and Electronic Map are becoming the key words of mobile business. The authors comprehend those factors as

  9. Modeling cognitive loads for evolving shared mental models in human-agent collaboration.

    Science.gov (United States)

    Fan, Xiaocong; Yen, John

    2011-04-01

    Recent research on human-centered teamwork highly demands the design of cognitive agents that can model and exploit human partners' cognitive load to enhance team performance. In this paper, we focus on teams composed of human-agent pairs and develop a system called Shared Mental Models for all--SMMall. SMMall implements a hidden Markov model (HMM)-based cognitive load model for an agent to predict its human partner's instantaneous cognitive load status. It also implements a user interface (UI) concept called shared belief map, which offers a synergic representation of team members' information space and allows them to share beliefs. An experiment was conducted to evaluate the HMM-based load models. The results indicate that the HMM-based load models are effective in helping team members develop a shared mental model (SMM), and the benefit of load-based information sharing becomes more significant as communication capacity increases. It also suggests that multiparty communication plays an important role in forming/evolving team SMMs, and when a group of agents can be partitioned into subteams, splitting messages by their load status can be more effective for developing subteam SMMs.

  10. Economic MPC based on LPV model for thermostatically controlled loads

    DEFF Research Database (Denmark)

    Zemtsov, Nikita; Hlava, Jaroslav; Frantsuzova, Galina

    2017-01-01

    Rapid increase of the renewable energy share in electricity production requires optimization and flexibility of the power consumption side. Thermostatically controlled loads (TCLs) have a large potential for regulation service provision. Economic model predictive control (MPC) is an advanced...... control method which can be used to syncronize the power consumption with undispatchable renewable electricity production. Thermal behavior of TCLs can be described by linear models based on energy balance of the system. In some cases, parameters of the model may be time-varying. In this work, we present....... As a case study, we present control system that minimizes operational cost of swimming pool heating system, where parameters of the model depend on the weather forecast. Simulation results demonstrate that the proposed method is able to deal with this kind of systems....

  11. Cognitive load and modelling of an algebra problem

    Science.gov (United States)

    Chinnappan, Mohan

    2010-09-01

    In the present study, I examine a modelling strategy as employed by a teacher in the context of an algebra lesson. The actions of this teacher suggest that a modelling approach will have a greater impact on enriching student learning if we do not lose sight of the need to manage associated cognitive loads that could either aid or hinder the integration of core concepts with processes that are at play. Results here also show that modelling a problem that is set within an authentic context helps learners develop a better appreciation of variables and relations that constitute the model. The teacher's scaffolding actions revealed the use of strategies that foster the development of connected, meaningful and more useable algebraic knowledge.

  12. Common Mobile Learning Characteristics--An Analysis of Mobile Learning Models and Frameworks

    Science.gov (United States)

    Imtinan, Umera; Chang, Vanessa; Issa, Tomayess

    2013-01-01

    Mobile learning offers learning opportunities to learners without the limitations of time and space. Mobile learning has introduced a number of flexible options to the learners across disciplines and at different educational levels. However, designing mobile learning content is an equally challenging task for the instructional designers.…

  13. A Danger Theory Based Mobile Virus Detection Model and Its Application in Inhibiting Virus

    Directory of Open Access Journals (Sweden)

    Tianliang Lu

    2012-08-01

    Full Text Available According to the propagation and destruction characteristics of mobile phone viruses, a virus detection model based on the Danger Theory is proposed. This model includes four phases: danger capture, antigen presentation, antibody generation and antibody distribution. In this model, local knowledge of mobile phones is exploited by the agents that are running in mobile phones to discover danger caused by viruses. The Antigen Presenting Cells (APCs present the antigen from mobile phones in the danger zone, and the Decision Center confirms the infection of viruses. After the antibody is generated by self-tolerating using the negative selection algorithm, the Decision Center distributes the antibody to mobile phones. Due to the distributed and cooperative mechanism of artificial immune system, the proposed model lowers the storage and computing consumption of mobile phones. The simulation results show that based on the mobile phone virus detection model, the proposed virus immunization strategy can effectively inhibit the propagation of mobile phone viruses.

  14. Estimating Demand Response Load Impacts: Evaluation of BaselineLoad Models for Non-Residential Buildings in California

    Energy Technology Data Exchange (ETDEWEB)

    Coughlin, Katie; Piette, Mary Ann; Goldman, Charles; Kiliccote,Sila

    2008-01-01

    Both Federal and California state policymakers areincreasingly interested in developing more standardized and consistentapproaches to estimate and verify the load impacts of demand responseprograms and dynamic pricing tariffs. This study describes a statisticalanalysis of the performance of different models used to calculate thebaseline electric load for commercial buildings participating in ademand-response (DR) program, with emphasis onthe importance of weathereffects. During a DR event, a variety of adjustments may be made tobuilding operation, with the goal of reducing the building peak electricload. In order to determine the actual peak load reduction, an estimateof what the load would have been on the day of the event without any DRactions is needed. This baseline load profile (BLP) is key to accuratelyassessing the load impacts from event-based DR programs and may alsoimpact payment settlements for certain types of DR programs. We testedseven baseline models on a sample of 33 buildings located in California.These models can be loosely categorized into two groups: (1) averagingmethods, which use some linear combination of hourly load values fromprevious days to predict the load on the event, and (2) explicit weathermodels, which use a formula based on local hourly temperature to predictthe load. The models were tested both with and without morningadjustments, which use data from the day of the event to adjust theestimated BLP up or down.Key findings from this study are: - The accuracyof the BLP model currently used by California utilities to estimate loadreductions in several DR programs (i.e., hourly usage in highest 3 out of10 previous days) could be improved substantially if a morning adjustmentfactor were applied for weather-sensitive commercial and institutionalbuildings. - Applying a morning adjustment factor significantly reducesthe bias and improves the accuracy of all BLP models examined in oursample of buildings. - For buildings with low load

  15. Mobility Models for Next Generation Wireless Networks Ad Hoc, Vehicular and Mesh Networks

    CERN Document Server

    Santi, Paolo

    2012-01-01

    Mobility Models for Next Generation Wireless Networks: Ad Hoc, Vehicular and Mesh Networks provides the reader with an overview of mobility modelling, encompassing both theoretical and practical aspects related to the challenging mobility modelling task. It also: Provides up-to-date coverage of mobility models for next generation wireless networksOffers an in-depth discussion of the most representative mobility models for major next generation wireless network application scenarios, including WLAN/mesh networks, vehicular networks, wireless sensor networks, and

  16. Modelling of pressure loads in a pressure suppression pool

    Energy Technology Data Exchange (ETDEWEB)

    Timperi, A.; Chauhan, M.; Paettikangas, T.; Niemi, J. [VTT Technical Research Centre of Finland (Finland)

    2013-06-15

    Rapid collapse of a large steam bubble is analyzed by using CFD and FEM calculations. In addition, a 1D code is written which takes into account the finite condensation rate. The 1D simulations are compared with the PPOOLEX experiment COL-01. By adjusting the condensation rate, the calculated pressure peak near the vent outlet could be made same as in the experiment. Scaling of the measured pressure loads to full-scale is studied by dimensional analyses and by review of the analysis of Sonin (1981). The structural response of containment during chugging is studied by using an FEM of containment with simplified geometry and loading which was created based on experimental data. The results are compared to the case in which desynchronization is absent, and chugging occurs simultaneously in every vent pipe. The desynchronized loading is created by giving random initiation times for chugs out of distribution corresponding to the desynchronization time presented by Kukita and Namatame (1985). CFD simulations of the PPOOLEX experiment MIX-03 were performed. In the experiment, clear chugging behavior was observed. In the simulation, the interphasial surface was much more stable and oscillation occurred at a higher frequency than in the experiment. The differences are likely caused by the turbulence model and too coarse numerical mesh, which causes numerical diffusion. (Author)

  17. Simulation model of load balancing in distributed computing systems

    Science.gov (United States)

    Botygin, I. A.; Popov, V. N.; Frolov, S. G.

    2017-02-01

    The availability of high-performance computing, high speed data transfer over the network and widespread of software for the design and pre-production in mechanical engineering have led to the fact that at the present time the large industrial enterprises and small engineering companies implement complex computer systems for efficient solutions of production and management tasks. Such computer systems are generally built on the basis of distributed heterogeneous computer systems. The analytical problems solved by such systems are the key models of research, but the system-wide problems of efficient distribution (balancing) of the computational load and accommodation input, intermediate and output databases are no less important. The main tasks of this balancing system are load and condition monitoring of compute nodes, and the selection of a node for transition of the user’s request in accordance with a predetermined algorithm. The load balancing is one of the most used methods of increasing productivity of distributed computing systems through the optimal allocation of tasks between the computer system nodes. Therefore, the development of methods and algorithms for computing optimal scheduling in a distributed system, dynamically changing its infrastructure, is an important task.

  18. Using Pulse Rate in Estimating Workload Evaluating a Load Mobilizing Activity

    Directory of Open Access Journals (Sweden)

    Juan Alberto Castillo

    2014-06-01

    Full Text Available Introduction: The pulse rate is a direct indicator of the state of the cardiovascular system, in ad-dition to being an indirect indicator of the energy expended in performing a task. The pulse of a person is the number of pulses recorded in a peripheral artery per unit time; the pulse appears as a pressure wave moving along the blood vessels, which are flexible, “in large arterial branches, speed of 7-10 m/s in the small arteries, 15 to 35 m/s”. Materials and methods: The aim of this study was to assess heart rate, using the technique of recording the frequency of the pulse, oxy-gen consumption and observation of work activity in the estimation of the workload in a load handling task for three situations: lift/transfer/deposit; before, during and after the task the pulse rate is recorded for 24 young volunteers (10 women and 14 men under laboratory conditions. We performed a gesture analysis of work activity and lifting and handling strategies. Results: We observed an increase between initial and final fp in both groups and for the two tasks, a dif¬ference is also recorded in the increase in heart rate of 17.5 for charging 75 % of the participants experienced an increase in fp above 100 lat./min. Par 25 kg, registered values indicate greater than 114 lat./min and 17.5 kg than 128 lat./min values. Discussion: The pulse rate method is recommended for its simplicity of use for operational staff, supervisors and managers and indus¬trial engineers not trained in the physiology method can also be used by industrial hygienists.

  19. Integration of LUTI models into sustainable urban mobility plans (SUMPs

    Directory of Open Access Journals (Sweden)

    Nikolaos Gavanas

    2016-06-01

    Full Text Available A literature review indicates that there is an increasing number of Land Use/Transport Interaction (LUTI models being used in policy analysis and support of urban land use, transport and environmental planning. In this context, LUTI models are considered to be useful for the development of scenarios during the preparatory stage of Sustainable Urban Mobility Plans (SUMPs. A SUMP can be defined as a strategic planning framework, proposed by the European Commission, for planning and design of an urban multimodal transport system, which combines multi-disciplinary policy analysis and decision making. The objective of a SUMP is to achieve sustainable urban mobility, i.e. accessibility for all, safety and security, reduction in emissions and energy consumption, efficient and cost-effective transport and an improvement in the urban environment. Based on the overall conceptual and methodological framework of LUTI models (Geurs and van Wee 2004, the scope of the proposed research is to fully integrate a LUTI model into a contemporary transport planning framework and, more specifically, into the SUMP structure. This paper focuses on the configuration of the integration pattern, according to which a LUTI model may evolve and interact with the planning process throughout the eleven elements of the SUMP, as well as the evaluation of the benefits and drawbacks from the implementation of the proposed pattern for the enhancement of SUMP and overall promotion of sustainable urban planning.

  20. Effects of Different Text Display Types on Reading Comprehension, Sustained Attention and Cognitive Load in Mobile Reading Contexts

    Science.gov (United States)

    Chen, Chih-Ming; Lin, Yu-Ju

    2016-01-01

    Despite the popularity of mobile reading devices, many studies have indicated that small screens restrict information transmission, adversely affecting reading performance on mobile devices. Moreover, mobile reading typically occurs in different reading contexts. Therefore, suitable text display type for mobile reading in different reading…

  1. Early Ankle Mobilization Promotes Healing in a Rabbit Model of Achilles Tendon Rupture.

    Science.gov (United States)

    Jielile, Jiasharete; Asilehan, Batiza; Wupuer, Aikeremu; Qianman, Bayixiati; Jialihasi, Ayidaer; Tangkejie, Wulanbai; Maimaitiaili, Abudouheilil; Shawutali, Nuerai; Badelhan, Aynaz; Niyazebieke, Hadelebieke; Aizezi, Adili; Aisaiding, Amuding; Bakyt, Yerzat; Aibek, Rakimbaiev; Wuerliebieke, Jianati

    2016-01-01

    The use of early mobilization of the ankle joint without orthosis in the treatment of Achilles tendon rupture has been advocated as the optimal management. The goal of this study was to compare outcomes in a postoperative rabbit model of Achilles tendon rupture between early mobilization and immobilized animals using a differential proteomics approach. In total, 135 rabbits were randomized into the control group (n=15), the postoperative cast immobilization (PCI) group (n=60), and the early mobilization (EM) group (n=60). A rupture of the Achilles tendon was created in each animal model and repaired microsurgically, and tendon samples were removed at 3, 7, 14, and 21 days postoperatively. Proteins were separated using 2-dimensional polyacrylamide gel electrophoresis and identified using peptide mass fingerprinting, tandem mass spectrometry, NCBI database searches, and bioinformatics analyses. A series of differentially expressed proteins were identified between groups, some of which may play an important role in Achilles tendon healing. Notable candidate proteins that were upregulated in the EM group were identified, such as CRMP-2, galactokinase 1, tropomyosin-4, and transthyretin. The healing of ruptured Achilles tendons appears to be affected at the level of protein expression with the use of early mobilization. The classic postoperative treatment of Achilles tendon rupture with an orthosis ignored the self-protecting instinct of humans. With a novel operative technique, the repaired tendon can persist the load that comes from traction in knee and ankle joint functional movement. In addition, kinesitherapy provided an excellent experimental outcome via a mechanobiological mechanism. Copyright 2016, SLACK Incorporated.

  2. Informal Workshop on Burial and Mobility Modeling of Munitions in the Underwater Environment

    Science.gov (United States)

    2014-12-01

    WORKSHOP REPORT Informal Workshop on Burial and Mobility Modeling of Munitions in the Underwater Environment DECEMBER 2014 SERDP and...SUBTITLE Informal Workshop on Burial and Mobility Modeling of Munitions 5a. CONTRACT NUMBER in the Underwater Environment 5b. GRANT...relevant project efforts. Quite often, underwater environments can be dynamic locations where munitions are more likely subject to mobility, burial , and

  3. Modeling and Control of a teletruck using electronic load sensing

    DEFF Research Database (Denmark)

    Hansen, Rico Hjerm; Iversen, Asger Malte; Jensen, Mads Schmidt;

    2010-01-01

    system is most commonly controlled using a hydro-mechanical control scheme called Hydraulic Load Sensing (HLS). However, with the demands for increased efficiency and controllability the HLS solutions are reaching their limits. Motivated by availability of electronic controllable fluid power...... the controller design for the ELS system, a complete model of the teletruck’s articulated arm and fluid power system is developed. To show the feasibility, a preliminary control structure for the ELS system is developed. The controller is tested on the machine, validating that features such as pump pressure...

  4. Physical and JIT Model Based Hybrid Modeling Approach for Building Thermal Load Prediction

    Science.gov (United States)

    Iino, Yutaka; Murai, Masahiko; Murayama, Dai; Motoyama, Ichiro

    Energy conservation in building fields is one of the key issues in environmental point of view as well as that of industrial, transportation and residential fields. The half of the total energy consumption in a building is occupied by HVAC (Heating, Ventilating and Air Conditioning) systems. In order to realize energy conservation of HVAC system, a thermal load prediction model for building is required. This paper propose a hybrid modeling approach with physical and Just-in-Time (JIT) model for building thermal load prediction. The proposed method has features and benefits such as, (1) it is applicable to the case in which past operation data for load prediction model learning is poor, (2) it has a self checking function, which always supervises if the data driven load prediction and the physical based one are consistent or not, so it can find if something is wrong in load prediction procedure, (3) it has ability to adjust load prediction in real-time against sudden change of model parameters and environmental conditions. The proposed method is evaluated with real operation data of an existing building, and the improvement of load prediction performance is illustrated.

  5. Aggregated Residential Load Modeling Using Dynamic Bayesian Networks

    Energy Technology Data Exchange (ETDEWEB)

    Vlachopoulou, Maria; Chin, George; Fuller, Jason C.; Lu, Shuai

    2014-09-28

    Abstract—It is already obvious that the future power grid will have to address higher demand for power and energy, and to incorporate renewable resources of different energy generation patterns. Demand response (DR) schemes could successfully be used to manage and balance power supply and demand under operating conditions of the future power grid. To achieve that, more advanced tools for DR management of operations and planning are necessary that can estimate the available capacity from DR resources. In this research, a Dynamic Bayesian Network (DBN) is derived, trained, and tested that can model aggregated load of Heating, Ventilation, and Air Conditioning (HVAC) systems. DBNs can provide flexible and powerful tools for both operations and planing, due to their unique analytical capabilities. The DBN model accuracy and flexibility of use is demonstrated by testing the model under different operational scenarios.

  6. Spatial correlations in bed load transport: evidence, importance, and modelling

    CERN Document Server

    Heyman, J; Mettra, F; Ancey, C

    2016-01-01

    This article examines the spatial {dynamics of bed load particles} in water. We focus particularly on the fluctuations of particle activity, which is defined as the number of moving particles per unit bed {length}. Based on a stochastic model recently proposed by \\citet{Ancey2013}, we derive the second moment of particle activity analytically; that is the spatial correlation functions of particle activity. From these expressions, we show that large moving particle clusters can develop spatially. Also, we provide evidence that fluctuations of particle activity are scale-dependent. Two characteristic lengths emerge from the model: a saturation length $\\ell_{sat}$ describing the length needed for a perturbation in particle activity to relax to the homogeneous solution, and a correlation length $\\ell_c$ describing the typical size of moving particle clusters. A dimensionless P\\'eclet number can also be defined according to the transport model. Three different experimental data sets are used to test the theoretica...

  7. Verifying a theoretical model of loads on an asymmetric disk

    Energy Technology Data Exchange (ETDEWEB)

    Krauze, K.

    1985-02-01

    The results are evaluated of testing a single asymmetric disk cutter used for coal cutting under operational conditions in an underground mine. The tests were aimed at verifying a mathematical model of coal cutting. The mean conventional pressure, a term used by the author, was determined. Forces acting on an asymmetric cutting disk calculated by mathematical modeling were compared to those determined in the tests. Comparisons showed that the model accurately describes coal cutting: in the case of tangential force error was not higher than 18%, in the case of lateral force it was not higher than 46% and in the case of compression force it was not higher than 15%. The method for calculating loads on an asymmetric disk cutter was characterized by reduced labor consumption and low number of tests. 1 reference.

  8. Modelling individual routines and spatio-temporal trajectories in human mobility

    CERN Document Server

    Pappalardo, Luca

    2016-01-01

    Human mobility modelling is of fundamental importance in a wide range of applications, such as the developing of protocols for mobile ad hoc networks or for what-if analysis and simulation in urban ecosystems. Current generative models generally fail in accurately reproducing the individuals' recurrent daily schedules and at the same time in accounting for the possibility that individuals may break the routine and modify their habits during periods of unpredictability of variable duration. In this article we present DITRAS (DIary-based TRAjectory Simulator), a framework to simulate the spatio-temporal patterns of human mobility in a realistic way. DITRAS operates in two steps: the generation of a mobility diary and the translation of the mobility diary into a mobility trajectory. The mobility diary is constructed by a Markov model which captures the tendency of individuals to follow or break their routine. The mobility trajectory is produced by a model based on the concept of preferential exploration and pref...

  9. Applicability of an exposure model for the determination of emissions from mobile phone base stations

    DEFF Research Database (Denmark)

    Breckenkamp, J; Neitzke, H P; Bornkessel, C

    2008-01-01

    Applicability of a model to estimate radiofrequency electromagnetic field (RF-EMF) strength in households from mobile phone base stations was evaluated with technical data of mobile phone base stations available from the German Net Agency, and dosimetric measurements, performed...

  10. Description and History of the MOBILE Highway Vehicle Emission Factor Model

    Science.gov (United States)

    MOBILE is an EPA model for estimating pollution from highway vehicles. It has been superseded by the Motor Vehicle Emission Simulator (MOVES). MOBILE calculates emissions of hydrocarbons (HC), oxides of nitrogen (NOx) and carbon monoxide (CO).

  11. Reliability-Based Modeling of Moisture and Load-Duration Effects

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Svensson, Staffan

    2005-01-01

    and moisture processes. Permanent and snow load sand moisture variations are considered and stochastic models are formulated in accordance with the load models in the Danish structural codes. A damage accumulation model based on fracture mechanics that accounts for both load duration and moisture effects...

  12. Towards Analytical Modeling for Persuasive Design Choices in Mobile Apps

    Directory of Open Access Journals (Sweden)

    Hamid Mukhtar

    2016-11-01

    Full Text Available Persuasive technology has emerged as a new field of research in the past decade with its applications in various domains including web-designing, human-computer interaction, healthcare systems, and social networks. Although persuasive technology has its roots in psychology and cognitive sciences, researchers from the computing disciplines are also increasingly interested in it. Unfortunately, the existing theories, models, and frameworks for persuasive system design fall short due to absence of systematic design processes mostly used in the computing domains as well as lack of support for appropriate post-analysis. This work provides some insight into such limitations and identifies the importance of analytical modeling for persuasion in mobile applications design. The authors illustrate, using a case study, that appropriate mathematical models can be applied together with user modeling to develop a persuasive system that will allow the designer to consider several design choices simultaneously.

  13. Modeling, Control and Simulation of a Novel Mobile Robotic System

    Science.gov (United States)

    Bai, Xiaoli; Davis, Jeremy; Doebbler, James; Turner, James D.; Junkins, John L.

    We in the Department of Aerospace Engineering at Texas A&M University are developing an autonomous mobile robotic system to emulate six degree of freedom (DOF) relative spacecraft motion during proximity operations. The base uses an active split offset castor (ASOC) drive train to achieve omni-directional planar motion with desired tracking position errors in the ± 1 cm range and heading angle error in the ±0.5° range. With six independently controlled wheels, we achieve a nominally uniform motor torque distribution and reduce the total disturbances with system control redundancy. A CAD (Computer-aided Design) sketch of our onethird scale model prototype is shown.

  14. Sonar sensor models and their application to mobile robot localization.

    Science.gov (United States)

    Burguera, Antoni; González, Yolanda; Oliver, Gabriel

    2009-01-01

    This paper presents a novel approach to mobile robot localization using sonar sensors. This approach is based on the use of particle filters. Each particle is augmented with local environment information which is updated during the mission execution. An experimental characterization of the sonar sensors used is provided in the paper. A probabilistic measurement model that takes into account the sonar uncertainties is defined according to the experimental characterization. The experimental results quantitatively evaluate the presented approach and provide a comparison with other localization strategies based on both the sonar and the laser. Some qualitative results are also provided for visual inspection.

  15. Mutual Interference Models for CDMA Mobile Communication Networks

    Directory of Open Access Journals (Sweden)

    K. Hrudkay

    2002-12-01

    Full Text Available Nowadays we are witnesses of a huge development one of the mostprogressive communication technology - mobile networks. The mainproblem in these networks is an elimination of the mutual interference,which, mainly in non-orthogonal CDMA networks, is the principalobstacle for reaching high transmission rates The aim of thiscontribution is to give simplified view to mutual interference modelsfor orthogonal and non-orthogonal CDMA networks. The contribution isintended mainly for PhD. students to help them to obtain an orientationin such a complicated areas, as the interference models for CDMAnetworks are.

  16. Model of knowledge management in mobile systems used for training

    Directory of Open Access Journals (Sweden)

    Chadwick CARRETO ARELLANO

    2014-11-01

    Full Text Available This work shows the development of a Knowledge Management Model (MAC applied to the training process in mobile devices for ease of use and access of different types of users to relevant information (anywhere and anytime. The MAC permit to manage knowledge, so that helps in the process of collection, classification and search of information according to a profile and academic needs as well as services related to the transformation of data and information for knowledge generation. The MAC aims to provide users, tools for skills development and allow the development of the training process with the use of limited capacity device with Internet connection.

  17. SWIM: A Simple Model to Generate Small Mobile Worlds

    CERN Document Server

    Mei, Alessandro

    2008-01-01

    This paper presents small world in motion (SWIM), a new mobility model for ad-hoc networking. SWIM is relatively simple, is easily tuned by setting just a few parameters, and generates traces that look real--synthetic traces have the same statistical properties of real traces. SWIM shows both experimentally and theoretically the presence of the power law and exponential decay dichotomy of inter-contact times, and, most importantly, our experiments show that it can predict very accurately the performance of forwarding protocols.

  18. Mammalian limb loading and chondral modeling during ontogeny.

    Science.gov (United States)

    Hammond, Ashley S; Ning, Jie; Ward, Carol V; Ravosa, Matthew J

    2010-04-01

    The adaptive growth response of cartilage, or chondral modeling, can result in changes in joint and limb proportions during ontogeny and ultimately contribute to the adult form. Despite Hamrick's (1999) reevaluation of the mechanisms of chondral modeling, the process of chondral modeling remains poorly studied in animal models. Here, we characterize the macro- and microanatomical responses of the femoral growth plate, articular cartilage, and bone in 15 juvenile Sus scrofa domestica subjected to different locomotor activity patterns. The exercised animals exhibit thinner cartilage zones, greater cellularity and larger proliferative chondrocyte areas in the growth plate, as well as larger femoral dimensions and a more elongate femoral head compared with sedentary controls. In general, the growth plate demonstrates greater adaptive changes than articular cartilage. Moreover, chondrocyte hypertrophy and proliferation were found to be responsive to locomotor loading and thus more important factors in chondral modeling than the extracellular matrix variables that were examined herein. In sum, the underlying mechanisms of adaptive chondrogenesis and bone plasticity are key to informing evolutionary and translational studies regarding determinants of variation in joint form and function. Given the disparity between the predictions of chondral modeling theory and our experimental findings, this suggests a need for further evaluation of chondral modeling responses during ontogeny.

  19. Numerical Modeling of Arsenic Mobility during Reductive Iron-Mineral Transformations.

    Science.gov (United States)

    Rawson, Joey; Prommer, Henning; Siade, Adam; Carr, Jackson; Berg, Michael; Davis, James A; Fendorf, Scott

    2016-03-01

    Millions of individuals worldwide are chronically exposed to hazardous concentrations of arsenic from contaminated drinking water. Despite massive efforts toward understanding the extent and underlying geochemical processes of the problem, numerical modeling and reliable predictions of future arsenic behavior remain a significant challenge. One of the key knowledge gaps concerns a refined understanding of the mechanisms that underlie arsenic mobilization, particularly under the onset of anaerobic conditions, and the quantification of the factors that affect this process. In this study, we focus on the development and testing of appropriate conceptual and numerical model approaches to represent and quantify the reductive dissolution of iron oxides, the concomitant release of sorbed arsenic, and the role of iron-mineral transformations. The initial model development in this study was guided by data and hypothesized processes from a previously reported,1 well-controlled column experiment in which arsenic desorption from ferrihydrite coated sands by variable loads of organic carbon was investigated. Using the measured data as constraints, we provide a quantitative interpretation of the processes controlling arsenic mobility during the microbial reductive transformation of iron oxides. Our analysis suggests that the observed arsenic behavior is primarily controlled by a combination of reductive dissolution of ferrihydrite, arsenic incorporation into or co-precipitation with freshly transformed iron minerals, and partial arsenic redox transformations.

  20. Phase transition and surface sublimation of a mobile Potts model.

    Science.gov (United States)

    Bailly-Reyre, A; Diep, H T; Kaufman, M

    2015-10-01

    We study in this paper the phase transition in a mobile Potts model by the use of Monte Carlo simulation. The mobile Potts model is related to a diluted Potts model, which is also studied here by a mean-field approximation. We consider a lattice where each site is either vacant or occupied by a q-state Potts spin. The Potts spin can move from one site to a nearby vacant site. In order to study the surface sublimation, we consider a system of Potts spins contained in a recipient with a concentration c defined as the ratio of the number of Potts spins N(s) to the total number of lattice sites N(L)=N(x)×N(y)×N(z). Taking into account the attractive interaction between the nearest-neighboring Potts spins, we study the phase transitions as functions of various physical parameters such as the temperature, the shape of the recipient, and the spin concentration. We show that as the temperature increases, surface spins are detached from the solid phase to form a gas in the empty space. Surface order parameters indicate different behaviors depending on the distance to the surface. At high temperatures, if the concentration is high enough, the interior spins undergo a first-order phase transition to an orientationally disordered phase. The mean-field results are shown as functions of temperature, pressure, and chemical potential, which confirm in particular the first-order character of the transition.

  1. Mobile intelligent agent entity model towards QoS guarantee

    Institute of Scientific and Technical Information of China (English)

    LI Jie; WANG Ru-chuan; BIAN Zhen-gai

    2006-01-01

    Implementing a flexible configuration of the QoS parameter in a distributed computing network has become a problem due to the weak scalability of current approaches.In an effort to solve this problem,an inner basic model of an intelligent agent (IA) is presented.The IA functionality was extended by introducing a primarily mobile agent.A QoS guarantee scheme was subsequently designed and implemented based on the model as well.By utilizing the proposed scheme,the IA can sense,predict and configure the data flow traffic.Since the communicating ability was considered and provided,the competition among different devices could be eliminated effectively and the global traffic can be optimized.The results of the simulations have shown that the proposed model can provide a QoS guarantee.

  2. Modeling the Determinants Influencing the Diffusion of Mobile Internet

    Science.gov (United States)

    Alwahaishi, Saleh; Snášel, Václav

    2013-04-01

    Understanding individual acceptance and use of Information and Communication Technology (ICT) is one of the most mature streams of information systems research. In Information Technology and Information System research, numerous theories are used to understand users' adoption of new technologies. Various models were developed including the Innovation Diffusion Theory, Theory of Reasoned Action, Theory of Planned Behavior, Technology Acceptance Model, and recently, the Unified Theory of Acceptance and Use of Technology. This research composes a new hybrid theoretical framework to identify the factors affecting the acceptance and use of Mobile Internet -as an ICT application- in a consumer context. The proposed model incorporates eight constructs: Performance Expectancy (PE), Effort Expectancy (EE), Facilitating Conditions (FC), Social Influences (SI), Perceived Value (PV), Perceived Playfulness (PP), Attention Focus (AF), and Behavioral intention (BI). Individual differences-namely, age, gender, education, income, and experience are moderating the effects of these constructs on behavioral intention and technology use.

  3. Mathematical Modeling of Column-Base Connections under Monotonic Loading

    Directory of Open Access Journals (Sweden)

    Gholamreza Abdollahzadeh

    2014-12-01

    Full Text Available Some considerable damage to steel structures during the Hyogo-ken Nanbu Earthquake occurred. Among them, many exposed-type column bases failed in several consistent patterns, such as brittle base plate fracture, excessive bolt elongation, unexpected early bolt failure, and inferior construction work, etc. The lessons from these phenomena led to the need for improved understanding of column base behavior. Joint behavior must be modeled when analyzing semi-rigid frames, which is associated with a mathematical model of the moment–rotation curve. The most accurate model uses continuous nonlinear functions. This article presents three areas of steel joint research: (1 analysis methods of semi-rigid joints; (2 prediction methods for the mechanical behavior of joints; (3 mathematical representations of the moment–rotation curve. In the current study, a new exponential model to depict the moment–rotation relationship of column base connection is proposed. The proposed nonlinear model represents an approach to the prediction of M–θ curves, taking into account the possible failure modes and the deformation characteristics of the connection elements. The new model has three physical parameters, along with two curve-fitted factors. These physical parameters are generated from dimensional details of the connection, as well as the material properties. The M–θ curves obtained by the model are compared with published connection tests and 3D FEM research. The proposed mathematical model adequately comes close to characterizing M–θ behavior through the full range of loading/rotations. As a result, modeling of column base connections using the proposed mathematical model can give crucial beforehand information, and overcome the disadvantages of time consuming workmanship and cost of experimental studies.

  4. Modelling Efficient Process Oriented Architecture for Secure Mobile Commerce Using Hybrid Routing Protocol in Mobile Adhoc Network

    Directory of Open Access Journals (Sweden)

    Chitra Kiran N

    2012-01-01

    Full Text Available The proposed research work presents a novel approach of process oriented architecture for secure mobile commerce framework using uniquely designed hybrid mobile adhoc routing protocols using reactive and proactive type in real time test-bed. The research work discusses about deployment of mobile commerce which is one of the emerging trend in mobile applications with huge demands. Majority of the existing system lacks either QoS or efficient security protocol when it relates to secure mobile transaction due to the reason that development in wireless technology involved in m-commerce is still in its nascent stage. The real time test bed has been implemented with 20 Intel Atom processor with 32 bit OS establishing an adhoc network and by providing a random mobility to achieve any file type transfer from node to node. For the real-time set up purpose, the experiment is conducted in wireless infrastructure with mobility using G-based Linksys wireless router. Iteration of experiments conducted shows a satisfactory results. This research journal will provide insights with various parameters, security requirements, and concepts which is required in creating a robust model for secure m-commerce system.

  5. Health behavior models in the age of mobile interventions: are our theories up to the task?

    Science.gov (United States)

    Riley, William T; Rivera, Daniel E; Atienza, Audie A; Nilsen, Wendy; Allison, Susannah M; Mermelstein, Robin

    2011-03-01

    Mobile technologies are being used to deliver health behavior interventions. The study aims to determine how health behavior theories are applied to mobile interventions. This is a review of the theoretical basis and interactivity of mobile health behavior interventions. Many of the mobile health behavior interventions reviewed were predominately one way (i.e., mostly data input or informational output), but some have leveraged mobile technologies to provide just-in-time, interactive, and adaptive interventions. Most smoking and weight loss studies reported a theoretical basis for the mobile intervention, but most of the adherence and disease management studies did not. Mobile health behavior intervention development could benefit from greater application of health behavior theories. Current theories, however, appear inadequate to inform mobile intervention development as these interventions become more interactive and adaptive. Dynamic feedback system theories of health behavior can be developed utilizing longitudinal data from mobile devices and control systems engineering models.

  6. A stochastic model of randomly accelerated walkers for human mobility

    Science.gov (United States)

    Gallotti, Riccardo; Bazzani, Armando; Rambaldi, Sandro; Barthelemy, Marc

    2016-08-01

    Recent studies of human mobility largely focus on displacements patterns and power law fits of empirical long-tailed distributions of distances are usually associated to scale-free superdiffusive random walks called Lévy flights. However, drawing conclusions about a complex system from a fit, without any further knowledge of the underlying dynamics, might lead to erroneous interpretations. Here we show, on the basis of a data set describing the trajectories of 780,000 private vehicles in Italy, that the Lévy flight model cannot explain the behaviour of travel times and speeds. We therefore introduce a class of accelerated random walks, validated by empirical observations, where the velocity changes due to acceleration kicks at random times. Combining this mechanism with an exponentially decaying distribution of travel times leads to a short-tailed distribution of distances which could indeed be mistaken with a truncated power law. These results illustrate the limits of purely descriptive models and provide a mechanistic view of mobility.

  7. Cavitation Influence in 1D Part-load Vortex Models

    Science.gov (United States)

    Dörfler, P. K.

    2016-11-01

    Residual swirl in the draft tube of Francis turbines may cause annoying low- frequency pulsation of pressure and power output, in particular during part-load operation. A 1D analytical model for these dynamic phenomena would enable simulation by some conventional method for computing hydraulic transients. The proper structure of such a model has implications for the prediction of prototype behaviour based on laboratory tests. The source of excitation as well as the dynamic transmission behaviour of the draft tube flow may both be described either by lumped or distributed parameters. The distributed version contains more information and, due to limited possibilities of identification, some data must be estimated. The distributed cavitation compliance is an example for this dilemma. In recent publications, the customary assumption of a constant wave speed has produced dubious results. The paper presents a more realistic model for distributed compressibility. The measured influence of the Thoma number is applied with the local cavitation factor. This concept is less sensitive to modelling errors and explains both the Thoma and Froude number influence. The possible effect of the normally unknown non-condensable gas content in the vortex cavity is shortly commented. Its measurement in future tests is recommended. It is also recommended to check the available analytical vortex models for possible dispersion effects.

  8. Low-complexity energy disaggregation using appliance load modelling

    Directory of Open Access Journals (Sweden)

    Hana Altrabalsi

    2016-01-01

    Full Text Available Large-scale smart metering deployments and energy saving targets across the world have ignited renewed interest in residential non-intrusive appliance load monitoring (NALM, that is, disaggregating total household’s energy consumption down to individual appliances, using purely analytical tools. Despite increased research efforts, NALM techniques that can disaggregate power loads at low sampling rates are still not accurate and/or practical enough, requiring substantial customer input and long training periods. In this paper, we address these challenges via a practical low-complexity lowrate NALM, by proposing two approaches based on a combination of the following machine learning techniques: k-means clustering and Support Vector Machine, exploiting their strengths and addressing their individual weaknesses. The first proposed supervised approach is a low-complexity method that requires very short training period and is fairly accurate even in the presence of labelling errors. The second approach relies on a database of appliance signatures that we designed using publicly available datasets. The database compactly represents over 200 appliances using statistical modelling of measured active power. Experimental results on three datasets from US, Italy, Austria and UK, demonstrate the reliability and practicality.

  9. Comparing the Impact of Mobile Nodes Arrival Patterns in Manets using Poisson and Pareto Models

    Directory of Open Access Journals (Sweden)

    John Tengviel

    2013-10-01

    Full Text Available Mobile Ad hoc Networks (MANETs are dynamic networks populated by mobile stations, or mobile nodes(MNs. Mobility model is a hot topic in many areas, for example, protocol evaluation, networkperformance analysis and so on.How to simulate MNs mobility is the problem we should consider if wewant to build an accurate mobility model. When new nodes can join and other nodes can leave the networkand therefore the topology is dynamic.Specifically, MANETs consist of a collection of nodes randomlyplaced in a line (not necessarily straight. MANETs do appear in many real-world network applicationssuch as a vehicular MANETs built along a highway in a city environment or people in a particularlocation. MNs in MANETs are usually laptops, PDAs or mobile phones.This paper presents comparative results that have been carried out via Matlab software simulation. Thestudy investigates the impact of mobility predictive models on mobile nodes’ parameters such as, thearrival rate and the size of mobile nodes in a given area using Pareto and Poisson distributions. Theresults have indicated that mobile nodes’ arrival rates may have influence on MNs population (as a largernumber in a location. The Pareto distribution is more reflective of the modeling mobility for MANETsthan the Poisson distribution.

  10. A Model Driven Framework to Address Challenges in a Mobile Learning Environment

    Science.gov (United States)

    Khaddage, Ferial; Christensen, Rhonda; Lai, Wing; Knezek, Gerald; Norris, Cathie; Soloway, Elliot

    2015-01-01

    In this paper a review of the pedagogical, technological, policy and research challenges and concepts underlying mobile learning is presented, followed by a brief description of categories of implementations. A model Mobile learning framework and dynamic criteria for mobile learning implementations are proposed, along with a case study of one site…

  11. A Model Driven Framework to Address Challenges in a Mobile Learning Environment

    Science.gov (United States)

    Khaddage, Ferial; Christensen, Rhonda; Lai, Wing; Knezek, Gerald; Norris, Cathie; Soloway, Elliot

    2015-01-01

    In this paper a review of the pedagogical, technological, policy and research challenges and concepts underlying mobile learning is presented, followed by a brief description of categories of implementations. A model Mobile learning framework and dynamic criteria for mobile learning implementations are proposed, along with a case study of one site…

  12. Perceived Convenience in an Extended Technology Acceptance Model: Mobile Technology and English Learning for College Students

    Science.gov (United States)

    Chang, Chi-Cheng; Yan, Chi-Fang; Tseng, Ju-Shih

    2012-01-01

    Since convenience is one of the features for mobile learning, does it affect attitude and intention of using mobile technology? The technology acceptance model (TAM), proposed by David (1989), was extended with perceived convenience in the present study. With regard to English language mobile learning, the variables in the extended TAM and its…

  13. Augmented models for improving vision control of a mobile robot

    DEFF Research Database (Denmark)

    Andersen, Gert Lysgaard; Christensen, Anders C.; Ravn, Ole

    1994-01-01

    This paper describes the modelling phases for the design of a path tracking vision controller for a three wheeled mobile robot. It is shown that, by including the dynamic characteristics of vision and encoder sensors and implementing the total system in one multivariable control loop, one can...... obtain good performance even when using standard low cost equipment and a comparatively low sampling rate. The plant model is a compound of kinematic, dynamic and sensor submodels, all integrated into a discrete state space representation. An intelligent strategy is applied for the vision sensor......, including the start up, normal operation, exception handling and shut down phases. Laboratory experiments show the validity of the approach using standard Kalman filter/LQR control design...

  14. Mobile phone model with metamaterials to reduce the exposure

    Science.gov (United States)

    Pinto, Yenny; Begaud, Xavier

    2016-04-01

    This work presents a terminal mobile model where an Inverted-F Antenna (IFA) is associated with three different kinds of metamaterials: artificial magnetic conductor (AMC), electromagnetic band gap (EBG) and resistive high-impedance surface (RHIS). The objective was to evaluate whether some metamaterials may be used to reduce exposure while preserving the antenna performances. The exposure has been evaluated using a simplified phantom model. Two configurations, antenna in front of the phantom and antenna hidden by the ground plane, have been evaluated. Results show that using an optimized RHIS, the SAR 10 g is reduced and the antenna performances are preserved. With RHIS solution, the SAR 10 g peak is reduced by 8 % when the antenna is located in front of the phantom and by 6 % when the antenna is hidden by ground plane.

  15. A combined gray neural network model of seasonal heating load forecast

    Institute of Scientific and Technical Information of China (English)

    QIAOXiaozhuang; YANGChangzhi

    2003-01-01

    Seasonal heating load time sequence has the double trends of increasing and fluctuating, so it''s difficult to select a model to forecast it. In this paper, a combined model of gray model and artificial neural network model was presented to forecast seasonal heating load. A concrete model was established and was verified through actual examples.

  16. An electricity price model with consideration to load and gas price effects

    Institute of Scientific and Technical Information of China (English)

    黄民翔; 陶小虎; 韩祯祥

    2003-01-01

    Some characteristics of the electricity load and prices are studied, and the relationship between electricity prices and gas (fuel) prices is analyzed in this paper. Because electricity prices are strongly dependent on load and gas prices, the authors constructed a model for electricity prices based on the effects of these two factors; and used the Geometric Mean Reversion Brownian Motion (GMRBM) model to describe the electricity load process, and a Geometric Brownian Motion(GBM) model to describe the gas prices; deduced the price stochastic process model based on the above load model and gas price model. This paper also presents methods for parameters estimation, and proposes some methods to solve the model.

  17. Electromagnetic simulations of simple models of ferrite loaded kickers

    CERN Document Server

    Zannini, Carlo; Salvant, B; Metral, E; Rumolo, G

    2010-01-01

    The kickers are major contributors to the CERN SPS beam coupling impedance. As such, they may represent a limitation to increasing the SPS bunch current in the frame of an intensity upgrade of the LHC. In this paper, CST Particle Studio time domain electromagnetic simulations are performed to obtain the longitudinal and transverse impedances/wake potentials of simplified models of ferrite loaded kickers. The simulation results have been successfully compared with some existing analytical expressions. In the transverse plane, the dipolar and quadrupolar contributions to the wake potentials have been estimated from the results of these simulations. For some cases, simulations have also been benchmarked against measurements on PS kickers. It turns out that the large simulated quadrupolar contributions of these kickers could explain both the negative total (dipolar+quadrupolar) horizontal impedance observed in bench measurements and the positive horizontal tune shift measured with the SPS beam.

  18. Sand - rubber mixtures submitted to isotropic loading: a minimal model

    Science.gov (United States)

    Platzer, Auriane; Rouhanifar, Salman; Richard, Patrick; Cazacliu, Bogdan; Ibraim, Erdin

    2017-06-01

    The volume of scrap tyres, an undesired urban waste, is increasing rapidly in every country. Mixing sand and rubber particles as a lightweight backfill is one of the possible alternatives to avoid stockpiling them in the environment. This paper presents a minimal model aiming to capture the evolution of the void ratio of sand-rubber mixtures undergoing an isotropic compression loading. It is based on the idea that, submitted to a pressure, the rubber chips deform and partially fill the porous space of the system, leading to a decrease of the void ratio with increasing pressure. Our simple approach is capable of reproducing experimental data for two types of sand (a rounded one and a sub-angular one) and up to mixtures composed of 50% of rubber.

  19. Development of Vehicle Model Test for Road Loading Analysis of Sedan Model

    Science.gov (United States)

    Mohd Nor, M. K.; Noordin, A.; Ruzali, M. F. S.; Hussen, M. H.

    2016-11-01

    Simple Structural Surfaces (SSS) method is offered as a means of organizing the process for rationalizing the basic vehicle body structure load paths. The application of this simplified approach is highly beneficial in the design development of modern passenger car structure especially during the conceptual stage. In Malaysia, however, there is no real physical model of SSS available to gain considerable insight and understanding into the function of each major subassembly in the whole vehicle structures. Based on this motivation, a physical model of SSS for sedan model with the corresponding model vehicle tests of bending and torsion is proposed in this work. The proposed approach is relatively easy to understand as compared to Finite Element Method (FEM). The results show that the proposed vehicle model test is capable to show that satisfactory load paths can give a sufficient structural stiffness within the vehicle structure. It is clearly observed that the global bending stiffness reduce significantly when more panels are removed from a complete SSS model. It is identified that parcel shelf is an important subassembly to sustain bending load. The results also match with the theoretical hypothesis, as the stiffness of the structure in an open section condition is shown weak when subjected to torsion load compared to bending load. The proposed approach can potentially be integrated with FEM to speed up the design process of automotive vehicle.

  20. Developing mobile educational apps: development strategies, tools and business models

    Directory of Open Access Journals (Sweden)

    Serena Pastore

    Full Text Available The mobile world is a growing and evolving market in all its aspects from hardware, networks, operating systems and applications. Mobile applications or apps are becoming the new frontier of software development, since actual digital users use mobile devi ...

  1. Open Data in Mobile Applications, New Models for Service Information

    Directory of Open Access Journals (Sweden)

    Manuel GÉRTRUDIX BARRIO

    2016-06-01

    Full Text Available The combination of open data generated by government and the proliferation of mobile devices enables the creation of new information services and improved delivery of existing ones. Significantly, it allows citizens access to simple,quick and effective way to information. Free applications that use open data provide useful information in real time, tailored to the user experience and / or geographic location. This changes the concept of “service information”. Both the infomediary sector and citizens now have new models of production and dissemination of this type of information. From the theoretical contextualization of aspects such as processes datification of reality, mobile registration of everyday experience, or reinterpretation of the service information, we analyze the role of open data in the public sector in Spain and its application concrete in building apps based on this data sets. The findings indicate that this is a phenomenon that will continue to grow because these applications provide useful and efficient information to decision-making in everyday life.

  2. Use of Hidden Markov Mobility Model for Location Based Services

    Directory of Open Access Journals (Sweden)

    Bhakti D. Shelar

    2014-07-01

    Full Text Available These days people prefer to use portable and wireless devices such as laptops, mobile phones, They are connected through satellites. As user moves from one point to other, task of updating stored information becomes difficult. Provision of Location based services to users, faces some challenges like limited bandwidth and limited client power. To optimize data accessibility and to minimize access cost, we can store frequently accessed data item in cache of client. So small size of cache is introduced in mobile devices. Data fetched from server is stored on cache. So requested data from user is provided from cache and not from remote server. Question arises that which data should be kept in the cache? Performance of cache majorly depends on the cache replacement policies which select data suitable for eviction from cache. This paper presents use of Hidden Markov Models(HMMs for prediction of user‟s future location. Then data item irrelevant to this predicted location is fetched out from the cache. The proposed approach clusters location histories according to their location characteristics and also it considers each user‟s previous actions. This results in producing high packet delivery ratio and minimum delay.

  3. Data-Driven Residential Load Modeling and Validation in GridLAB-D

    Energy Technology Data Exchange (ETDEWEB)

    Gotseff, Peter; Lundstrom, Blake

    2017-05-11

    Accurately characterizing the impacts of high penetrations of distributed energy resources (DER) on the electric distribution system has driven modeling methods from traditional static snap shots, often representing a critical point in time (e.g., summer peak load), to quasi-static time series (QSTS) simulations capturing all the effects of variable DER, associated controls and hence, impacts on the distribution system over a given time period. Unfortunately, the high time resolution DER source and load data required for model inputs is often scarce or non-existent. This paper presents work performed within the GridLAB-D model environment to synthesize, calibrate, and validate 1-second residential load models based on measured transformer loads and physics-based models suitable for QSTS electric distribution system modeling. The modeling and validation approach taken was to create a typical GridLAB-D model home that, when replicated to represent multiple diverse houses on a single transformer, creates a statistically similar load to a measured load for a given weather input. The model homes are constructed to represent the range of actual homes on an instrumented transformer: square footage, thermal integrity, heating and cooling system definition as well as realistic occupancy schedules. House model calibration and validation was performed using the distribution transformer load data and corresponding weather. The modeled loads were found to be similar to the measured loads for four evaluation metrics: 1) daily average energy, 2) daily average and standard deviation of power, 3) power spectral density, and 4) load shape.

  4. Managing charging loads of electric vehicles by monetary incentives. A model-based optimization; Monetaere Anreize zur Steuerung der Ladelast von Elektrofahrzeugen. Eine modellgestuetzte Optimierung

    Energy Technology Data Exchange (ETDEWEB)

    Paetz, Alexandra-Gwyn; Kaschub, Thomas; Kopp, Martin; Jochem, Patrick; Fichtner, Wolf [Karlsruher Institut fuer Technologie, Karlsruhe (Germany). Inst. fuer Industriebetriebslehre und Industrielle Produktion

    2013-03-15

    Electric mobility is supposed to contribute to climate policy targets by reducing CO{sub 2}-emissions in the transportation sector. Increasing penetration rates of electric vehicles (EV) can lead to new challenges in the electricity sector, especially with regard to local distribution networks. Thus the management of charging loads is discussed as a key issue in energy economics. Due to their long parking times, high electricity and power demand, EV seem to be predestined for load management. Monetary incentives as dynamic pricing can be suitable for that: They reflect the current supply situation, pass the information to the consumers and can thus lead to a corresponding charging behaviour. In this article we analyse this interaction between dynamic pricing and charging loads. For this reason we have developed the optimization model DS-Opt+. It models a total number of 4,000 households in two residential areas of a major city with regard to its electricity demand, its mobility behaviour and its equipment of photovoltaic systems. Four different pricing models are tested for their effects on charging behaviour and thus the total load of the residential area. The results illustrate that only fairly high penetration rates of EV lead to remarkably higher electricity demand and require some load management. The tested dynamic pricing models are suitable for influencing charging loads; load-based tariffs are best in achieving a balanced load curve. In our analysis uncontrolled charging strategies are superior regarding a balanced load curve than controlled strategies by time-varying tariffs. Our results lead to several implications relevant for the energy industry and further research.

  5. A dynamic modelling approach for estimating critical loads of nitrogen based on plant community changes under a changing climate

    Energy Technology Data Exchange (ETDEWEB)

    Belyazid, Salim, E-mail: salim@belyazid.com [Belyazid Consulting and Communication, Stationsvaegen 13, SE-517 34 Bollebygd (Sweden); Kurz, Dani [EKG Geoscience, Maulbeerstrasse 14, CH-3011 Bern (Switzerland); Braun, Sabine [Institut fuer Angewandte Planzenbiologie, Sandgrubenstrasse 25, CH-4124 Schoenenbuch (Switzerland); Sverdrup, Harald [Department of Chemical Engineering, Lund University, PO Box 124, SE-221 00 Lund (Sweden); Rihm, Beat [Meteotest, Fabrikstrasse 14, CH-3012 Bern (Switzerland); Hettelingh, Jean-Paul [Coordination Centre for Effects, PO Box 303, NL-3720 AH Bilthoven (Netherlands)

    2011-03-15

    A dynamic model of forest ecosystems was used to investigate the effects of climate change, atmospheric deposition and harvest intensity on 48 forest sites in Sweden (n = 16) and Switzerland (n = 32). The model was used to investigate the feasibility of deriving critical loads for nitrogen (N) deposition based on changes in plant community composition. The simulations show that climate and atmospheric deposition have comparably important effects on N mobilization in the soil, as climate triggers the release of organically bound nitrogen stored in the soil during the elevated deposition period. Climate has the most important effect on plant community composition, underlining the fact that this cannot be ignored in future simulations of vegetation dynamics. Harvest intensity has comparatively little effect on the plant community in the long term, while it may be detrimental in the short term following cutting. This study shows: that critical loads of N deposition can be estimated using the plant community as an indicator; that future climatic changes must be taken into account; and that the definition of the reference deposition is critical for the outcome of this estimate. - Research highlights: > Plant community changes can be used to estimate critical loads of nitrogen. > Climate change is decisive for future changes of geochemistry and plant communities. > Climate change cannot be ignored in estimates of critical loads. > The model ForSAFE-Veg was successfully used to set critical loads of nitrogen. - Plant community composition can be used in dynamic modelling to estimate critical loads of nitrogen deposition, provided the appropriate reference deposition, future climate and target plant communities are defined.

  6. Modeling Prioritized Hard Handoff Management Scheme for Wireless Mobile Networks

    Directory of Open Access Journals (Sweden)

    BISWAJIT BHOWMIK

    2012-08-01

    Full Text Available The channel associated with the current connection serviced by a base station is changed while a call is in progress. Usually, continuous service is achieved by supporting handoff from one cell to another. It is often initiated either by crossing a cell boundary or by deterioration in quality of the signal in the current channel. The existing call is then changed to a new base station. For the traffics which are non stationary at and are away from the servicing base station, the chances of a call to be handed off are increasing. In this paper we propose a scheme MH_2S to modeling and implementing a traffic model with handoff behavior for wireless mobile networks . The simulation model MH_2S with priority is developed to investigate the performance behavior of hard handoff strategy. Novelty of the proposed model MH_2S results that it can improve call blocking rate of handoff calls. In addition to this, measurement of blocking probabilities for both originating calls and handoff calls is another impressive achievement of the model.

  7. Steady States in SIRS Epidemical Model of Mobile Individuals

    Institute of Scientific and Technical Information of China (English)

    ZHANG Duan-Ming; LIU Dan; HE Min-Hua; YU Xiao-Ling; PAN Gui-Jun; SUN Hong-Zhang; SU Xiang-Ying; SUN Fan; YIN Yan-Ping; LI Rui

    2006-01-01

    We consider an epidemical model within socially interacting mobile individuals to study the behaviors of steady statesof epidemic propagation in 2D networks. Using mean-field approximation and large scale simulations, we recover the usual epidemic behavior with critical thresholds δc and pc below which infectious disease dies out. For the population density δ far above δc, it is found that there is linear relationship between contact rate λ and the population density δ in the main. At the same time, the result obtained from mean-field approximation is compared with our numerical result, and it is found that these two results are similar by and large but not completely the same.

  8. Steady States in SIRS Epidemical Model of Mobile Individuals

    Science.gov (United States)

    Zhang, Duan-Ming; He, Min-Hua; Yu, Xiao-Ling; Pan, Gui-Jun; Sun, Hong-Zhang; Su, Xiang-Ying; Sun, Fan; Yin, Yan-Ping; Li, Rui; Liu, Dan

    2006-01-01

    We consider an epidemical model within socially interacting mobile individuals to study the behaviors of steady states of epidemic propagation in 2D networks. Using mean-field approximation and large scale simulations, we recover the usual epidemic behavior with critical thresholds δc and pc below which infectious disease dies out. For the population density δ far above δc, it is found that there is linear relationship between contact rate λ and the population density δ in the main. At the same time, the result obtained from mean-field approximation is compared with our numerical result, and it is found that these two results are similar by and large but not completely the same.

  9. A Trust Model Based on Service Classification in Mobile Services

    CERN Document Server

    Liu, Yang; Xia, Feng; Lv, Xiaoning; Bu, Fanyu

    2010-01-01

    Internet of Things (IoT) and B3G/4G communication are promoting the pervasive mobile services with its advanced features. However, security problems are also baffled the development. This paper proposes a trust model to protect the user's security. The billing or trust operator works as an agent to provide a trust authentication for all the service providers. The services are classified by sensitive value calculation. With the value, the user's trustiness for corresponding service can be obtained. For decision, three trust regions are divided, which is referred to three ranks: high, medium and low. The trust region tells the customer, with his calculated trust value, which rank he has got and which authentication methods should be used for access. Authentication history and penalty are also involved with reasons.

  10. Earthquake Early Warning Beta Users: Java, Modeling, and Mobile Apps

    Science.gov (United States)

    Strauss, J. A.; Vinci, M.; Steele, W. P.; Allen, R. M.; Hellweg, M.

    2014-12-01

    Earthquake Early Warning (EEW) is a system that can provide a few to tens of seconds warning prior to ground shaking at a user's location. The goal and purpose of such a system is to reduce, or minimize, the damage, costs, and casualties resulting from an earthquake. A demonstration earthquake early warning system (ShakeAlert) is undergoing testing in the United States by the UC Berkeley Seismological Laboratory, Caltech, ETH Zurich, University of Washington, the USGS, and beta users in California and the Pacific Northwest. The beta users receive earthquake information very rapidly in real-time and are providing feedback on their experiences of performance and potential uses within their organization. Beta user interactions allow the ShakeAlert team to discern: which alert delivery options are most effective, what changes would make the UserDisplay more useful in a pre-disaster situation, and most importantly, what actions users plan to take for various scenarios. Actions could include: personal safety approaches, such as drop cover, and hold on; automated processes and procedures, such as opening elevator or fire stations doors; or situational awareness. Users are beginning to determine which policy and technological changes may need to be enacted, and funding requirements to implement their automated controls. The use of models and mobile apps are beginning to augment the basic Java desktop applet. Modeling allows beta users to test their early warning responses against various scenarios without having to wait for a real event. Mobile apps are also changing the possible response landscape, providing other avenues for people to receive information. All of these combine to improve business continuity and resiliency.

  11. New ways of innovation: an application of the Cyclical Innovation Model to the mobile telecom industry

    NARCIS (Netherlands)

    Berkhout, A.J.G.; Van der Duin, P.

    2006-01-01

    New developments in the mobile telecom industry, such as growing transmisson bandwidth and sector-crossing business alliances, change the way in which mobile telco’s are innovating. Traditional innovation models, such as the well-known single-company linear model ('pipeline model'), do not describe

  12. Numerical Model for Conduction-Cooled Current Lead Heat Loads

    CERN Document Server

    White, M J; Brueck, H D; 10.1063/1.4706965

    2012-01-01

    Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world, however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. The XFEL (X-Ray Free Electron Laser) magnets are operated at 2 K, which makes vapor-cooled current leads impractical due to the sub-atmospheric bath pressure. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal inte...

  13. Load distribution model and voltage static profile of Smart Grid

    Institute of Scientific and Technical Information of China (English)

    SUN Qiu-ye; LI Zhong-xu; YANG Jun; LUO Yan-hong

    2010-01-01

    Voltage profiles of feeders with the connection of distributed generations(DGs)were investigated.A unified typical load distribution model was established.Based on this model,exact expressions of feeder voltage profile with single and double DGs were derived and used to analyze the impact of DG's location and capacity on the voltage profile quantitatively.Then,a general formula of the voltage profile was derived.The limitation of single DG and necessity of multiple DGs for voltage regulation were also discussed.Through the simulation,voltage profiles of feeders with single and double DGs were compared.The voltage excursion rate is 7.40% for only one DG,while 2.48% and 2.36% for double DGs.It is shown that the feeder voltage can be retained in a more appropriate range with multiple DGs than with only one DG.Distributing the total capacity of DGs is better than concentrating it at one point.

  14. Modeling the Dynamic Load/Unload Behavior of Ceramics under Impact Loading

    Science.gov (United States)

    1990-07-01

    34The Mechanics of Fracture under High-rate Stress Loading," in: A.P. Bazant , ed., Preprints of the William Prager Symposium on Mechanics of...A120 3 Ceramics," Jour. of Appl. Phy., Vol 42, Number 1, Jan 71, p 276. 8. W. Herrmann, R.J. Lawrence, and D.S. Mason, "Strain Hardening and

  15. Security Model for Microsoft Based Mobile Sales Management Application in Private Cloud Computing

    Directory of Open Access Journals (Sweden)

    Kuan Chee Houng

    2013-05-01

    Full Text Available The Microsoft-based mobile sales management application is a sales force management application that currently running on Windows Mobile 6.5. It handles sales-related activity and cuts down the administrative task of sales representative. Then, Windows launch a new mobile operating system, Windows Phone and stop providing support to Windows Mobile. This has become an obstacle for Windows Mobile development. From time to time, Windows Mobile will be eliminated from the market due to no support provided by Microsoft. Besides that, Windows Mobile application cannot run on Windows Phone mobile operating system due to lack of compatibility. Therefore, applications those run on Windows Mobile need to find a solution addressing this problem. The rise of cloud computing technology in delivering software as a service becomes a solution. The Microsoft-based mobile sales management application delivers a service to run in a web browser, rather than limited by certain type of mobile that run the Windows Mobile operating system. However, there are some security issues need to concern in order to deliver the Microsoft-based mobile application as a service in private cloud computing. Therefore, security model is needed to answer the security issues in private cloud computing. This research is to propose a security model for the Microsoft-based mobile sales management application in private cloud computing. Lastly, a User Acceptance Test (UAT is carried out to test the compatibility between proposed security model of Microsoft-based mobile sales management application in a private cloud and tablet computers.

  16. TCP performance evaluation over AODV and DSDV in RW and SN mobility models

    Institute of Scientific and Technical Information of China (English)

    REN Wei; YEUNG D.Y.; JIN Hai

    2006-01-01

    This paper presents evaluation and comparison of the TCP performance in different mobile scenarios generated by Random Waypoint (RW) and Social Network (SN) mobility models. To our knowledge, TCP performance in SN mobility is discussed for the first time. The impact of AODV and DSDV routing protocols on the TCP goodput, delay and drop rate performance is also discussed. Extensive simulation results and analysis showed that TCP has better performance over AODV than over DSDV and has more stable performance in SN mobility than in RW mobility. We suggest using more mobility models, in particular, such as SN, in the evaluations of the transport layer or routing layer protocols because the mobility patterns have impacts on the protocol performance.

  17. The M-2 ocean tide loading wave in Alaska: vertical and horizontal displacements, modelled and observed

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Scherneck, H.G.

    2003-01-01

    Crustal deformations caused by surface load due to ocean tides are strongly dependent on the surface load closest to the observing site. In order to correctly model this ocean loading effect near irregular coastal areas, a high-resolution coastline is required. A test is carried out using two GPS...

  18. A model for Quick Load Analysis for monopile-type offshore wind turbine substructures

    DEFF Research Database (Denmark)

    Schløer, Signe; Castillo, Laura Garcia; Fejerskov, Morten

    2016-01-01

    A model for Quick Load Analysis, QuLA, of an offshore wind turbine substructure is presented. The aerodynamic rotor loads and damping are precomputed for a load-based configuration. The dynamic structural response is represented by the first global fore-aft mode only and is computed in the freque...

  19. Evaluation of Atmospheric Loading and Improved Troposphere Modelling

    Science.gov (United States)

    Zelensky, Nikita P.; Chinn, Douglas S.; Lemoine, F. G.; Le Bail, Karine; Pavlis, Despina E.

    2012-01-01

    Forward modeling of non-tidal atmospheric loading displacements at geodetic tracking stations have not routinely been included in Doppler Orbitography and Radiopositionning Integrated by Satellite (DORIS) or Satellite Laser Ranging (SLR) station analyses for either POD applications or reference frame determination. The displacements which are computed from 6-hourly models such as the ECMWF and can amount to 3-10 mm in the east, north and up components depending on the tracking station locations. We evaluate the application of atmospheric loading in a number ways using the NASA GSFC GEODYN software: First we assess the impact on SLR & DORIS-determined orbits such as Jason-2, where we evaluate the impact on the tracking data RMS of fit and how the total orbits are changed with the application of this correction. Preliminary results show an RMS radial change of 0.5 mm for Jason-2 over 54 cycles and a total change in the Z-centering of the orbit of 3 mm peak-to-peak over one year. We also evaluate the effects on other DORIS-satellites such as Cryosat-2, Envisat and the SPOT satellites. In the second step, we produce two SINEX time series based on data from available DORIS satellites and assess the differences in WRMS, scale and Helmert translation parameters. Troposphere refraction is obviously an important correction for radiometric data types such as DORIS. We evaluate recent improvements in DORIS processing at GSFC including the application of the Vienna Mapping Function (VMF1) grids with a-priori hydrostatic (VZHDs) and wet (VZWDs) zenith delays. We reduce the gridded VZHD at the stations height using pressure and temperature derived from GPT (strategy 1) and Saastamoinen. We discuss the validation of the VMF1 implementation and its application to the Jason-2 POD processing, compared to corrections using the Niell mapping function and the GMF. Using one year of data, we also assess the impact of the new troposphere corrections on the DORIS-only solutions, most

  20. Modelling and simulation of load connected fixed blade wind turbine with permanent magnet synchronous generators

    OpenAIRE

    Al-Toma, AS; Taylor, GA; Abbod, M

    2015-01-01

    This paper presents the modelling and simulation of a wind turbine driven Permanent Magnet Synchronous Generator connected to a load. The system has been tested at different wind speeds. The machine side controller has been designed to match Maximum Power Point Tracking (MPPT) to obtain high extraction of wind power when connected to a load, while the load side controller fixes the DC voltage that is converted to the AC load voltage. Detailed plots of voltage and current profiles are also pre...

  1. A model of human walking energetics with an elastically-suspended load.

    Science.gov (United States)

    Ackerman, Jeffrey; Seipel, Justin

    2014-06-03

    Elastically-suspended loads have been shown to reduce the peak forces acting on the body while walking with a load when the suspension stiffness and damping are minimized. However, it is not well understood how elastically-suspended loads can affect the energetic cost of walking. Prior work shows that elastically suspending a load can yield either an increase or decrease in the energetic cost of human walking, depending primarily on the suspension stiffness, load, and walking speed. It would be useful to have a simple explanation that reconciles apparent differences in existing data. The objective of this paper is to help explain different energetic outcomes found with experimental load suspension backpacks and to systematically investigate the effect of load suspension parameters on the energetic cost of human walking. A simple two-degree-of-freedom model is used to approximate the energetic cost of human walking with a suspended load. The energetic predictions of the model are consistent with existing experimental data and show how the suspension parameters, load mass, and walking speed can affect the energetic cost of walking. In general, the energetic cost of walking with a load is decreased compared to that of a stiffly-attached load when the natural frequency of a load suspension is tuned significantly below the resonant walking frequency. The model also shows that a compliant load suspension is more effective in reducing the energetic cost of walking with low suspension damping, high load mass, and fast walking speed. This simple model could improve our understanding of how elastic load-carrying devices affect the energetic cost of walking with a load.

  2. Modelling of Building Interiors with Mobile Phone Sensor Data

    Directory of Open Access Journals (Sweden)

    Julian Rosser

    2015-06-01

    Full Text Available Creating as-built plans of building interiors is a challenging task. In this paper we present a semi-automatic modelling system for creating residential building interior plans and their integration with existing map data to produce building models. Taking a set of imprecise measurements made with an interactive mobile phone room mapping application, the system performs spatial adjustments in accordance with soft and hard constraints imposed on the building plan geometry. The approach uses an optimisation model that exploits a high accuracy building outline, such as can be found in topographic map data, and the building topology to improve the quality of interior measurements and generate a standardised output. We test our system on building plans of five residential homes. Our evaluation shows that the approach enables construction of accurate interior plans from imprecise measurements. The experiments report an average accuracy of 0.24 m, close to the 0.20 m recommended by the CityGML LoD4 specification.

  3. Model-based description of environment interaction for mobile robots

    Science.gov (United States)

    Borghi, Giuseppe; Ferrari, Carlo; Pagello, Enrico; Vianello, Marco

    1999-01-01

    We consider a mobile robot that attempts to accomplish a task by reaching a given goal, and interacts with its environment through a finite set of actions and observations. The interaction between robot and environment is modeled by Partially Observable Markov Decision Processes (POMDP). The robot takes its decisions in presence of uncertainty about the current state, by maximizing its reward gained during interactions with the environment. It is able to self-locate into the environment by collecting actions and perception histories during the navigation. To make the state estimation more reliable, we introduce an additional information in the model without adding new states and without discretizing the considered measures. Thus, we associate to the state transition probabilities also a continuous metric given through the mean and the variance of some significant sensor measurements suitable to be kept under continuous form, such as odometric measurements, showing that also such unreliable data can supply a great deal of information to the robot. The overall control system of the robot is structured as a two-levels layered architecture, where the low level implements several collision avoidance algorithms, while the upper level takes care of the navigation problem. In this paper, we concentrate on how to use POMDP models at the upper level.

  4. Wind load modeling for topology optimization of continuum structures

    NARCIS (Netherlands)

    Zakhama, R.; Abdalla, M.M.; Gürdal, Z.; Smaoui, H.

    2010-01-01

    Topology optimization of two and three dimensional structures subject to dead and wind loading is considered. The wind loading is introduced into the formulation by using standard expressions for the drag force, and a strategy is devised so that wind pressure is ignored where there is no surface obs

  5. Physical Modelling of Cyclic Laterally Loaded Pile in Cohesionless Soil

    DEFF Research Database (Denmark)

    Hansen, Mette; Wolf, Torben K.; Rasmussen, Kristian L.

    Offshore wind turbines are normally founded with large diameter monopiles and placed in rough environments subjected to variable lateral loads from wind and waves. A long-term lateral loading may create rotation (tilt) of the pile by change in the pile-soil system which is critical in the service...

  6. Bi-Modal Authentication in Mobile Environments Using Session Variability Modelling

    OpenAIRE

    Motlicek, Petr; El Shafey, Laurent; Wallace, Roy; McCool, Chris; Marcel, Sébastien

    2012-01-01

    We present a state-of-the-art bi-modal authentication system for mobile environments, using session variability modelling. We examine inter-session variability modelling (ISV) and joint factor analysis (JFA) for both face and speaker authentication and evaluate our system on the largest bi-modal mobile authentication database available, the MOBIO database, with over 61 hours of audio-visual data captured by 150 people in uncontrolled environments on a mobile phone. Our system achieves 2.6% an...

  7. Deformations in the Shoulder Tissues During Load Carriage: A Computational Model.

    Science.gov (United States)

    Hadid, Amir; Belzer, Noa; Shabshin, Nogah; Epstein, Yoram; Gefen, Amit

    2015-11-01

    Shoulder soft tissue deformations seem to be one of the limiting factors of load carriage among soldiers and recreational backpackers that are required to carry heavy loads. Yet, there are no loading limits related to the forces borne by the shoulders, and the backpacks designs are not consistent with providing pressure relief from this sensitive anatomical region. The aim of this study was to develop a model that will enable to study the biomechanical loads that develop in the shoulder under heavy loads and to help in optimizing load carriage systems design. A 3-dimensional, anatomically accurate finite element model of a human shoulder was constructed based on MRI scans. The model was developed to calculate the effective stresses on the skin below the shoulder strap (superficial loads) and the effective strain in the brachial plexus region (inner tissue deformation) for loads of up to 35 kg. The model successfully predicted deformations in the soft tissue surrounding the brachial plexus when compared with deformations measured from load-bearing MRI scans. The model yielded a skin pressure mapping, which showed pressure hotspots in the clavicle region. Inner tissue deformations mapping, as assessed by brachial plexus envelop strains, were found to peak at 30% effective strain at the lateral aspect below the pectoralis muscle. The newly developed model successfully predicted soft tissue deformations in the shoulder related to backpacks. This model can be used to optimize load carriage systems for better distribution of pressure over the shoulders and lower inner tissue deformations.

  8. User Demand Aware Grid Scheduling Model with Hierarchical Load Balancing

    Directory of Open Access Journals (Sweden)

    P. Suresh

    2013-01-01

    Full Text Available Grid computing is a collection of computational and data resources, providing the means to support both computational intensive applications and data intensive applications. In order to improve the overall performance and efficient utilization of the resources, an efficient load balanced scheduling algorithm has to be implemented. The scheduling approach also needs to consider user demand to improve user satisfaction. This paper proposes a dynamic hierarchical load balancing approach which considers load of each resource and performs load balancing. It minimizes the response time of the jobs and improves the utilization of the resources in grid environment. By considering the user demand of the jobs, the scheduling algorithm also improves the user satisfaction. The experimental results show the improvement of the proposed load balancing method.

  9. Improving the Model for Energy Consumption Load Demand Forecasting

    Science.gov (United States)

    Bunnoon, Pituk; Chalermyanont, Kusumal; Limsakul, Chusak

    This paper proposes an application of a filter method in preprocessing stage for mid-term load demand forecasting to improve electricity load forecasting and to guarantee satisfactory forecasting accuracy. Case study employs the historical electricity consumption demand data in Thailand which were recorded in the 12 years of 1997 through to 2007. The load demand forecasted value is used for unit commitment and fuel reserve planning in the power system. This method consists of a trend component and a cyclical component decomposed from the original load demand using the Hodrick-Prescott (HP) filter in the preprocessing stage and the forecasting of each component using Double Neural Networks (DNNs) in the forecasting stage. Experimental results show that with preprocessing before forecasting can predict the load demand better than that without preprocessing.

  10. Probabilistic model for multi-axial load combinations for wind turbines

    DEFF Research Database (Denmark)

    Dimitrov, Nikolay Krasimirov

    2016-01-01

    for determining contemporaneous loads. Using examples with simulated loads on a 10 MW wind turbine,the behavior of the bending moments acting on a blade section is illustrated under different conditions.The loading direction most critical for material failure is determined using a finite-element model......The article presents a model describing the joint probability distribution of multiple load components acting on a wind turbine blade cross section. The problem of modelling the probability distribution of load time histories with large periodic components is addressed by dividing the signal...... of the blade cross section on which load combinations with different directions but with equal probability are applied. By defining a joint probability distribution and return-period contours for multiple load components,the suggested procedure is applicable to different aspects of the design of wind turbine...

  11. Experimental study on settlement of model piles in frozen soil under dynamic loading

    Institute of Scientific and Technical Information of China (English)

    张建明; 朱元林; 张家懿

    1999-01-01

    Test results show that the settlement process of model piles is mainly the rheological process of frozen soil under shear loading. The settlement rate of model piles increases with increasing temperature of frozen soil, decreasing roughness of pile surface and increasing rigidity of pile foundation. As the water content of frozen soil reaches its saturation value, the settlement rate is the least. When the level of loading is higher, the settlement rate under dynamic loading is less than that under static loading. With the level of loading lowering, the effect between dynamic and static loading on the settlement rate becomes close gradually. Under the present test conditions, the settlement rate of model piles is independent of the frequency of dynamic loads.

  12. Does loading influence the severity of cartilage degeneration in the canine groove-model of OA?

    NARCIS (Netherlands)

    Vos, P.; Intema, F.; El, B. van; Groot, J. de; Bijlsma, J.W.J.; Lafeber, F.; Mastbergen, S.

    2009-01-01

    Many animal models are used to study osteoarthritis (OA). In these models the role of joint loading in the development of OA is not fully understood. We studied the effect of loading on the development of OA in the canine Groove-model. In ten female beagle dogs OA was induced in one knee according t

  13. Does Loading Influence the Severity of Cartilage Degeneration in the Canine Groove-Model of OA?

    NARCIS (Netherlands)

    Vos, Petra; Intema, Femke; van El, Benno; DeGroot, Jeroen; Bijlsma, J. W. J.; Lafeber, Floris; Mastbergen, Simon

    2009-01-01

    Many animal models are used to study osteoarthritis (OA). In these models the role of joint loading in the development of CA is not fully understood. We studied the effect of loading on the development of CIA in the canine Groove-model. In ten female beagle dogs OA was induced in one knee according

  14. A New Traffic Model for Mobile Wireless Networks

    Institute of Scientific and Technical Information of China (English)

    ZHAO Fang-ming; JIANC Ling-ge; HE Chen

    2007-01-01

    A new traffic model for mobile wireless networks was given and analysed.In the model, it is considered of traffic characteristic for two special periods of time.A pre-emptive priority scheme combined with channel borrowing strategy according to the speciality was proposed.All the channels can be used by non-real-time services,and real-time services are given higher priority for they are allowed to pre-empt channels used by non-real-time services.Either real-time handoff requests or non-real-time handoff requests can be queued in queues when there is no channel can be used.Some channels are reserved for real-time handoff requests, which can also be used by nonreal-time service when they are idle.Simulation results are also given.It is seen that our scheme performs better than other schemes when the arrival rate of real-time services is much higher than non-real-time services.

  15. A 3D world model builder with a mobile robot

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.; Faugeras, O. (INRIA, Valbonne (France))

    1992-08-01

    This article describes a system to incrementally build a world model with a mobile robot in an unknown environment. The model is, for the moment, segment based. A trinocular stereo system is used to build a local map about the environment. A global map is obtained by integrating a sequence of stereo frames taken when the robot navigates in the environment. The emphasis of this article is on the representation of the uncertainty of 3D segments from stereo and on the integration of segments from multiple views. The proposed representation is simple and very convenient to characterize the uncertainty of segment. A Kalman filter is used to merge matched line segments. An important characteristic of this integration strategy is that a segment observed by the stereo system corresponds only to one part of the segment in space, so the union of the different observations gives a better estimate on the segment in space. The authors have succeeded in integrating 35 stereo frames taken in their robot room.

  16. Mobility Model for Self-Organizing and Cooperative MSN and MANET Systems

    Directory of Open Access Journals (Sweden)

    Andrzej Sikora

    2012-03-01

    Full Text Available Self-organization mechanisms are used for building scalable systems consisting of a huge number of subsystems. In computer networks, self-organizing is especially important in ad hoc networking. A self-organizing ad hoc network is a collection of wireless devices that collaborate with each other to form a network system that adapts to achieve a goal or goals. Such network is often built from mobile devices that may spontaneously create a network and dynamically adapted to changes in an unknown environment. Mobility pattern is a critical element that influences the performance characteristics of mobile sensor networks (MSN and mobile ad hoc networks (MANET. In this paper, we survey main directions to mobility modeling. We describe a novel algorithm for calculating mobility patterns for mobile devices that is based on a cluster formation and an artificial potential function. Finally, we present the simulation results of its application to a rescue mission planning.

  17. Using Video Modeling and Mobile Technology to Teach Social Skills

    Science.gov (United States)

    Haydon, Todd; Musti-Rao, Shobana; McCune, Ashley; Clouse, Diane E.; McCoy, Dacia M.; Kalra, Hilary D.; Hawkins, Renee O.

    2017-01-01

    There has been growing interest in the field of education regarding the use of technology in classrooms to improve student outcomes. Specifically, researchers have demonstrated positive outcomes for using mobile technology with students with autism spectrum disorder (ASD). Fewer studies have used mobile technology with students with emotional and…

  18. MoCha, a model for distributed mobile channels

    NARCIS (Netherlands)

    J.V. Guillen Scholten (Juan)

    2004-01-01

    textabstractA mobile channel is a link that provides an asynchronous and anonymous means of communication between components in a distributed system. A channel is called mobile if either of its (channel-)ends can be moved from one component to another without the knowledge of the component at its

  19. Using Video Modeling and Mobile Technology to Teach Social Skills

    Science.gov (United States)

    Haydon, Todd; Musti-Rao, Shobana; McCune, Ashley; Clouse, Diane E.; McCoy, Dacia M.; Kalra, Hilary D.; Hawkins, Renee O.

    2017-01-01

    There has been growing interest in the field of education regarding the use of technology in classrooms to improve student outcomes. Specifically, researchers have demonstrated positive outcomes for using mobile technology with students with autism spectrum disorder (ASD). Fewer studies have used mobile technology with students with emotional and…

  20. WhichWayNC: A Model for Mobile Media Development

    Science.gov (United States)

    Clark, Meredith D.

    2015-01-01

    This student newsroom ethnography examines the emergent culture and values of a group-created news and information content with a mobile-first focus. Using semi-structured interviews from 12 participants working on a mobile-optimized summer news project, the study provides insights on the work practices of the digital student newsroom. Validated…

  1. Fatigue Load Estimation through a Simple Stochastic Model

    Directory of Open Access Journals (Sweden)

    Pedro G. Lind

    2014-12-01

    Full Text Available We propose a procedure to estimate the fatigue loads on wind turbines, based on a recent framework used for reconstructing data series of stochastic properties measured at wind turbines. Through a standard fatigue analysis, we show that it is possible to accurately estimate fatigue loads in any wind turbine within one wind park, using only the load measurements at one single turbine and the set of wind speed measurements. Our framework consists of deriving a stochastic differential equation that describes the evolution of the torque at one wind turbine driven by the wind speed. The stochastic equation is derived directly from the measurements and is afterwards used for predicting the fatigue loads for neighboring turbines. Such a framework could be used to mitigate the financial efforts usually necessary for placing measurement devices in all wind turbines within one wind farm. Finally, we also discuss the limitations and possible improvements of the proposed procedure.

  2. Model-based Diagnostics for Propellant Loading Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The loading of spacecraft propellants is a complex, risky operation. Therefore, diagnostic solutions are neces- sary to quickly identify when a fault occurs, so that...

  3. Fatigue Loads Estimation Through a Simple Stochastic Model

    CERN Document Server

    Lind, Pedro G; Peinke, Joachim

    2014-01-01

    We propose a procedure to estimate the fatigue loads on wind turbines, based in a recent framework used for reconstructing data series of stochastic properties measured at wind turbines. Through a standard fatigue analysis, we show that it is possible to accurately estimate fatigue loads in any wind turbine within one wind park, using only the load measurements at one single turbine and the set of wind speed measurements. Our framework consists of deriving a stochastic differential equation that describes the evolution of the torque at one wind turbine driven by the wind speed. The stochastic equation is derived directly from the measurements and is afterwards used for predicting the fatigue loads at neighboring turbines. Such a framework could be used to mitigate the financial efforts usually necessary for placing measurement devices in all wind turbines within one wind farm. Finally, we also discuss the limitations and possible improvements of the proposed procedure.

  4. Molecular mobility with respect to accessible volume in Monte Carlo lattice model for polymers

    Science.gov (United States)

    Diani, J.; Gilormini, P.

    2017-02-01

    A three-dimensional cubic Monte Carlo lattice model is considered to test the impact of volume on the molecular mobility of amorphous polymers. Assuming classic polymer chain dynamics, the concept of locked volume limiting the accessible volume around the polymer chains is introduced. The polymer mobility is assessed by its ability to explore the entire lattice thanks to reptation motions. When recording the polymer mobility with respect to the lattice accessible volume, a sharp mobility transition is observed as witnessed during glass transition. The model ability to reproduce known actual trends in terms of glass transition with respect to material parameters, is also tested.

  5. Morpes: A Model for Personalized Rendering of Web Content on Mobile Devices

    CERN Document Server

    Kuppusamy, K S; 10.5121/ijfcst.2012.2204

    2012-01-01

    With the tremendous growth in the information communication sector, the mobile phones have become the prime information communication devices. The convergence of traditional telephony with the modern web enabled communication in the mobile devices has made the communication much effective and simpler. As mobile phones are becoming the crucial source of accessing the contents of the World Wide Web which was originally designed for personal computers, has opened up a new challenge of accommodating the web contents in to the smaller mobile devices. This paper proposes an approach towards building a model for rendering the web pages in mobile devices. The proposed model is based on a multi-dimensional web page segment evaluation model. The incorporation of personalization in the proposed model makes the rendering user-centric. The proposed model is validated with a prototype implementation.

  6. Testing for time-varying loadings in dynamic factor models

    DEFF Research Database (Denmark)

    Mikkelsen, Jakob Guldbæk

    factors. The squared correlation coefficient times the sample size has a limiting chi-squared distribution. The test can be made robust to serial correlation in the idiosyncratic errors. We find evidence for factor loadings variance in over half of the variables in a dataset for the US economy, while...... there is evidence of time-varying loadings on the risk factors underlying portfolio returns for around 80% of the portfolios....

  7. Support Vector Regression Model Based on Empirical Mode Decomposition and Auto Regression for Electric Load Forecasting

    Directory of Open Access Journals (Sweden)

    Hong-Juan Li

    2013-04-01

    Full Text Available Electric load forecasting is an important issue for a power utility, associated with the management of daily operations such as energy transfer scheduling, unit commitment, and load dispatch. Inspired by strong non-linear learning capability of support vector regression (SVR, this paper presents a SVR model hybridized with the empirical mode decomposition (EMD method and auto regression (AR for electric load forecasting. The electric load data of the New South Wales (Australia market are employed for comparing the forecasting performances of different forecasting models. The results confirm the validity of the idea that the proposed model can simultaneously provide forecasting with good accuracy and interpretability.

  8. On dynamic loads in parallel shaft transmissions. 1: Modelling and analysis

    Science.gov (United States)

    Lin, Edward Hsiang-Hsi; Huston, Ronald L.; Coy, John J.

    1987-01-01

    A model of a simple parallel-shaft, spur-gear transmission is presented. The model is developed to simulate dynamic loads in power transmissions. Factors affecting these loads are identified. Included are shaft stiffness, local compliance due to contact stress, load sharing, and friction. Governing differential equations are developed and a solution procedure is outlined. A parameter study of the solutions is presented in NASA TM-100181 (AVSCOM TM-87-C-3).

  9. CACM: A New Coordination Model in Mobile Agent-Based Information Retrieval Applications

    Institute of Scientific and Technical Information of China (English)

    TANGXinhuai; ZHANGYaying; YAOYinxiong; YOUJinyuan

    2005-01-01

    In mobile agent systems, an application may be composed of several mobile agents that cooperatively perform a task. Multiple mobile agents need to communicate and interact with each other to accomplish their cooperative goal. Coordination model aims to provide solutions to interactions between concurrent activities, hiding the computing details and focusing on interaction between activities. A Context-aware coordination model (CACM), which combines mobility and coordination, is proposed for mobile agent applications, i.e. in mobile agent based information retrieval applications. The context-aware coordination model transfers interactions between agents from globally coupling interactions to locally uncoupling tuple space interactions. In addition, programmable tuple space is adopted to solve the problems of context-aware coordination introduced by mobility and data heterogeneity in mobile agent systems. Furthermore, environment specific and application specific coordination policy can be integrated into the programmable tuple space for customized requirements. Finally an application sample system-information retrieval in mobile agent applications is carried out to test the performance of the proposed model.

  10. GMove: Group-Level Mobility Modeling Using Geo-Tagged Social Media

    Science.gov (United States)

    Zhang, Chao; Zhang, Keyang; Yuan, Quan; Zhang, Luming; Hanratty, Tim; Han, Jiawei

    2017-01-01

    Understanding human mobility is of great importance to various applications, such as urban planning, traffic scheduling, and location prediction. While there has been fruitful research on modeling human mobility using tracking data (e.g., GPS traces), the recent growth of geo-tagged social media (GeoSM) brings new opportunities to this task because of its sheer size and multi-dimensional nature. Nevertheless, how to obtain quality mobility models from the highly sparse and complex GeoSM data remains a challenge that cannot be readily addressed by existing techniques. We propose GMove, a group-level mobility modeling method using GeoSM data. Our insight is that the GeoSM data usually contains multiple user groups, where the users within the same group share significant movement regularity. Meanwhile, user grouping and mobility modeling are two intertwined tasks: (1) better user grouping offers better within-group data consistency and thus leads to more reliable mobility models; and (2) better mobility models serve as useful guidance that helps infer the group a user belongs to. GMove thus alternates between user grouping and mobility modeling, and generates an ensemble of Hidden Markov Models (HMMs) to characterize group-level movement regularity. Furthermore, to reduce text sparsity of GeoSM data, GMove also features a text augmenter. The augmenter computes keyword correlations by examining their spatiotemporal distributions. With such correlations as auxiliary knowledge, it performs sampling-based augmentation to alleviate text sparsity and produce high-quality HMMs. Our extensive experiments on two real-life data sets demonstrate that GMove can effectively generate meaningful group-level mobility models. Moreover, with context-aware location prediction as an example application, we find that GMove significantly outperforms baseline mobility models in terms of prediction accuracy.

  11. GMove: Group-Level Mobility Modeling Using Geo-Tagged Social Media.

    Science.gov (United States)

    Zhang, Chao; Zhang, Keyang; Yuan, Quan; Zhang, Luming; Hanratty, Tim; Han, Jiawei

    2016-08-01

    Understanding human mobility is of great importance to various applications, such as urban planning, traffic scheduling, and location prediction. While there has been fruitful research on modeling human mobility using tracking data (e.g., GPS traces), the recent growth of geo-tagged social media (GeoSM) brings new opportunities to this task because of its sheer size and multi-dimensional nature. Nevertheless, how to obtain quality mobility models from the highly sparse and complex GeoSM data remains a challenge that cannot be readily addressed by existing techniques. We propose GMove, a group-level mobility modeling method using GeoSM data. Our insight is that the GeoSM data usually contains multiple user groups, where the users within the same group share significant movement regularity. Meanwhile, user grouping and mobility modeling are two intertwined tasks: (1) better user grouping offers better within-group data consistency and thus leads to more reliable mobility models; and (2) better mobility models serve as useful guidance that helps infer the group a user belongs to. GMove thus alternates between user grouping and mobility modeling, and generates an ensemble of Hidden Markov Models (HMMs) to characterize group-level movement regularity. Furthermore, to reduce text sparsity of GeoSM data, GMove also features a text augmenter. The augmenter computes keyword correlations by examining their spatiotemporal distributions. With such correlations as auxiliary knowledge, it performs sampling-based augmentation to alleviate text sparsity and produce high-quality HMMs. Our extensive experiments on two real-life data sets demonstrate that GMove can effectively generate meaningful group-level mobility models. Moreover, with context-aware location prediction as an example application, we find that GMove significantly outperforms baseline mobility models in terms of prediction accuracy.

  12. QUEUEING MODELS IN MOBILE AD-HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    S. Baskar

    2014-01-01

    Full Text Available The Mobile Ad-hoc Networks (MANETs has gain an essential part of the attention of researchers and become very well-liked in last few years. MANETs can operate with no fixed communications and can live rapid changes in the network topology. They can be studied officially as graphs in which the set of boundaries varies in time. One of the main methods to determine the presentation of MANETs is simulation. This study proposes Enhanced Probabilistic Adhoc on Demand Distance Vector (EPAODV routing protocol, which solves the broadcast storm problem of Adhoc on Demand Distance Vector (AODV. Our evaluation of MANETs is based on the evaluation of the throughput, end to end delay and packet delivery ratio. We evaluated the end to end delay as it is one of the most important characteristic evaluation metric in computer networks. In our proposed algorithm, using a queueing model M/M/C: ∞/FIFO, we are able to enhance that better results are obtained in the case EPAODV protocol such as increasing throughput, data delivery ratio and then decreasing the end delay compare to the existing protocols.

  13. Clinical practice models in nursing education: implication for students' mobility.

    Science.gov (United States)

    Dobrowolska, B; McGonagle, I; Jackson, C; Kane, R; Cabrera, E; Cooney-Miner, D; Di Cara, V; Pajnkihar, M; Prlić, N; Sigurdardottir, A K; Kekuš, D; Wells, J; Palese, A

    2015-03-01

    In accordance with the process of nursing globalization, issues related to the increasing national and international mobility of student and qualified nurses are currently being debated. Identifying international differences and comparing similarities for mutual understanding, development and better harmonization of clinical training of undergraduate nursing students is recommended. The aim of the study was to describe and compare the nature of the nursing clinical practice education models adopted in different countries. A qualitative approach involving an expert panel of nurses was adopted. The Nominal Group Technique was employed to develop the initial research instrument for data collection. Eleven members of the UDINE-C network, representing institutions engaged in the process of professional nursing education and research (universities, high schools and clinical institutes), participated. Three data collection rounds were implemented. An analysis of the findings was performed, assuring rigour. Differences and homogeneity are reported and discussed regarding: (a) the clinical learning requirements across countries; (b) the prerequisites and clinical learning process patterns; and (c) the progress and final evaluation of the competencies achieved. A wider discussion is needed regarding nursing student exchange and internalization of clinical education in placements across European and non-European countries. A clear strategy for nursing education accreditation and harmonization of patterns of organization of clinical training at placements, as well as strategies of student assessment during this training, are recommended. There is also a need to develop international ethical guidelines for undergraduate nursing students gaining international experience. © 2015 International Council of Nurses.

  14. Behavioral analysis of EPA`s MOBILE emission factor model. Discussion paper

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, W.; McConnell, V.D.; Cannon, M.

    1998-06-01

    This report provides a review and assessment of several important aspects of the MOBILE model, EPA`s computer model for estimating emission factors for mobile sources. Inventory models like MOBILE have many uses, but the authors focus primarily on the Model`s role for estimation of emission reduction credits from I/M [Inspection/Maintenance] programs. The authors concentrate on how the model incorporates behavioral responses to I/M regulations. The effectiveness of I/M programs in practice are likely to be strongly influenced by the behavior of motorists, mechanics and even state regulatory authorities. In addition to an examination of model structure and assumptions, the authors examine the empirical data used to calibrate the model, much of which is hard coded and not amenable to change by users. Finally, the authors test the sensitivity of MOBILE results to certain assumptions with behavioral content.

  15. Determinants of Mobile Service Acceptance in Saudi Arabia: A Revised UTAUT Model

    OpenAIRE

    Mutlaq B. Alotaibi

    2013-01-01

    This paper identifies factors that determine user acceptance of the mobile version of the stock exchange system in Saudi Arabia (Tadawul). It examines the conditions under which users use Mobile Tadawul (M-Tadawul), the findings will provide an in-depth understanding of the mobile financial services for developers, potential users and Information Technology (IT) managers. The study proposed a theoretical framework based on the Unified Theory of Acceptance and Use of Technology (UTAUT) model. ...

  16. Comparison of Random Waypoint & Random Walk Mobility Model under DSR, AODV & DSDV MANET Routing Protocols

    CERN Document Server

    Aslam, Muhammad Zaheer

    2011-01-01

    Mobile Adhoc Network is a kind of wireless ad hoc network where nodes are connected wirelessly and the network is self configuring. MANET may work in a standalone manner or may be a part of another network. In this paper we have compared Random Walk Mobility Model and Random Waypoint Mobility Model over two reactive routing protocols Dynamic Source Routing (DSR) and Adhoc On-Demand Distance Vector Routing (AODV) protocol and one Proactive routing protocol Distance Sequenced Distance Vector Routing (DSDV) Our analysis showed that DSR, AODV & DSDV under Random Walk and Random Way Point Mobility models have similar results for similar inputs however as the pause time increases so does the difference in performance rises. They show that their motion, direction, angle of direction, speed is same under both mobility models. We have made their analysis on packet delivery ratio, throughput and routing overhead. We have tested them with different criteria like different number of nodes, speed and different maximum...

  17. Research of dynamic loading in a drivetrain by means of mathematical modeling

    Science.gov (United States)

    Sokolov-Dobrev, N. S.; Ljashenko, M. V.; Shekhovtsov, V. V.; Potapov, P. V.

    2017-02-01

    This paper describes the development of the initial full dynamic model of a caterpillar agricultural tractor ‘Chetra 6C-315’ drivetrain, the processes of the model reduction; the mathematical apparatus for defining loads acting on drivetrain shafting elements. The main results of computational researches of dynamic loadings of drivetrain elements in various tractor operation modes are presented.

  18. Three-dimensional loading model for periodontal ligament regeneration in vitro

    NARCIS (Netherlands)

    Berendsen, A.D.; Smit, T.H.; Walboomers, X.F.; Everts, V.; Jansen, J.A.; Bronckers, A.L.J.J.

    2009-01-01

    In this study we present a new three-dimensional (3D) model to study effects of mechanical loading on tendon/ligament formation in vitro. The model mimics a functional periodontal ligament (PDL), which anchors dental roots to the jaw bone and transfers the axial load of mastication to the jaw bone.

  19. Three-dimensional loading model for periodontal ligament regeneration in vitro.

    NARCIS (Netherlands)

    Berendsen, A.D.; Smit, T.H.; Walboomers, X.F.; Everts, V.; Jansen, J.A.; Bronckers, A.L.

    2009-01-01

    In this study we present a new three-dimensional (3D) model to study effects of mechanical loading on tendon/ligament formation in vitro. The model mimics a functional periodontal ligament (PDL), which anchors dental roots to the jaw bone and transfers the axial load of mastication to the jaw bone.

  20. Low Load Model of a Once-through Boiler with Recirculation

    DEFF Research Database (Denmark)

    Trangbæk, Klaus

    2006-01-01

    A dynamic simulation model of a once-through boiler in low to medium load is developed. When the system is in low load, water from the evaporator is recirculated through a bottle. This recirculation system is included in the model, which is then shown to fit closed-loop data from a real plant...

  1. Finite element models for the steady state analysis of moving loads

    NARCIS (Netherlands)

    Kok, A.W.M.

    2000-01-01

    The analysis of structures subjected to fast moving loads is a subject of growing interest in railway and pavement engineering. The applications of transient analyses using finite element models, however, are still very limited. The faster a load moves the more elements we need to model the structu

  2. Three-dimensional loading model for periodontal ligament regeneration in vitro.

    NARCIS (Netherlands)

    Berendsen, A.D.; Smit, T.H.; Walboomers, X.F.; Everts, V.; Jansen, J.A.; Bronckers, A.L.

    2009-01-01

    In this study we present a new three-dimensional (3D) model to study effects of mechanical loading on tendon/ligament formation in vitro. The model mimics a functional periodontal ligament (PDL), which anchors dental roots to the jaw bone and transfers the axial load of mastication to the jaw bone.

  3. Three-dimensional loading model for periodontal ligament regeneration in vitro

    NARCIS (Netherlands)

    A.D. Berendsen; T.H. Smit; X.F. Walboomers; V. Everts; J.A. Jansen; A.L.J.J. Bronckers

    2009-01-01

    In this study we present a new three-dimensional (3D) model to study effects of mechanical loading on tendon/ligament formation in vitro. The model mimics a functional periodontal ligament (PDL), which anchors dental roots to the jaw bone and transfers the axial load of mastication to the jaw bone.

  4. Physical Modelling of Bucket Foundation Under Long-Term Cyclic Lateral Loading

    DEFF Research Database (Denmark)

    Foglia, Aligi; Ibsen, Lars Bo; Andersen, Lars Vabbersgaard

    2012-01-01

    functioning. In this article a 1g physical model of bucket foundation under horizontal and moment cyclic loading is described. A testing program including four tests was carried out. Every test was conducted for at least 30000 cycles, each with different loading features. The capability of the model...

  5. A Hybrid Short-Term Power Load Forecasting Model Based on the Singular Spectrum Analysis and Autoregressive Model

    Directory of Open Access Journals (Sweden)

    Hongze Li

    2014-01-01

    Full Text Available Short-term power load forecasting is one of the most important issues in the economic and reliable operation of electricity power system. Taking the characteristics of randomness, tendency, and periodicity of short-term power load into account, a new method (SSA-AR model which combines the univariate singular spectrum analysis and autoregressive model is proposed. Firstly, the singular spectrum analysis (SSA is employed to decompose and reconstruct the original power load series. Secondly, the autoregressive (AR model is used to forecast based on the reconstructed power load series. The employed data is the hourly power load series of the Mid-Atlantic region in PJM electricity market. Empirical analysis result shows that, compared with the single autoregressive model (AR, SSA-based linear recurrent method (SSA-LRF, and BPNN (backpropagation neural network model, the proposed SSA-AR method has a better performance in terms of short-term power load forecasting.

  6. New ways of innovation: an application of the Cyclical Innovation Model to the mobile telecom industry

    OpenAIRE

    Berkhout, A.J.G.; Van der Duin, P.

    2006-01-01

    New developments in the mobile telecom industry, such as growing transmisson bandwidth and sector-crossing business alliances, change the way in which mobile telco’s are innovating. Traditional innovation models, such as the well-known single-company linear model ('pipeline model'), do not describe anymore how innovation occurs in today's practice. An alternative way of looking at innovation is the boundary-crossing Cyclic Innovation Model (CIM). It views innovation processes as coupled 'cycl...

  7. Modeling of damage evaluation in thin composite plate loaded by pressure loading

    Directory of Open Access Journals (Sweden)

    Dudinský M.

    2012-12-01

    Full Text Available This article presents the results of numerical analysis of elastic damage of thin laminated long fiber-reinforced composite plate consisting of unidirectional layers which is loaded by uniformly distributed pressure. The analysis has been performed by means of the finite element method (FEM. The numerical implementation uses layered plate finite elements based on the Kirchhoff plate theory. System of nonlinear equations has been solved by means of the Newton- Raphson procedure. Evolution of damage has been solved using the return-mapping algorithm based on the continuum damage mechanics (CDM. The analysis was performed using own program created in MATLAB. Problem of laminated fiber-reinforced composite plate fixed on edges for two different materials and three different laminate stacking sequences (LSS was simulated. Evolution of stresses vs. strains and also evolution of damage variables in critical points of the structure are shown.

  8. A Mobile Forensic Readiness Model aimed at Minimizing Cyber Bullying

    National Research Council Canada - National Science Library

    Victor R Kebande; Nickson M Karie; Stacey Omeleze

    2016-01-01

    .... Trends of cyber-bullying, for example, are on the increase and recent studies in South Africa have shown that the use of mobile devices among school pupils between the ages of 2 to 17 years is at 60...

  9. A stochastic model of randomly accelerated walkers for human mobility

    National Research Council Canada - National Science Library

    Gallotti, Riccardo; Bazzani, Armando; Rambaldi, Sandro; Barthelemy, Marc

    2016-01-01

    Recent studies of human mobility largely focus on displacements patterns and power law fits of empirical long-tailed distributions of distances are usually associated to scale-free superdiffusive random walks called Lévy flights...

  10. MEMO2 - MEthane goes MObile - MEasurements and Modelling - Part 2

    Science.gov (United States)

    Röckmann, Thomas; Walter, Sylvia

    2017-04-01

    As mitigation of climate change is a key scientific and societal challenge, the 2015 United Nations Climate Change Conference in Paris (COP21) agreed to limit global warming "well below" 2˚ C and, if possible, below 1.5˚ C. Reaching this target requires massive reductions of greenhouse gas emissions, and achieving significant reduction of greenhouse gas emissions is a logical headline targets of the EU climate action and of the H2020 strategy. CH4 emissions are a major contributor to Europe's global warming impact and emissions are not well quantified yet. There are significant discrepancies between official inventories of emissions and estimates derived from direct atmospheric measurement. Effective emission reduction can only be achieved if sources are properly quantified, and mitigation efforts are verified. New advanced combinations of measurement and modelling are needed to archive such quantification. MEMO2 will contribute to the targets of the EU with a focus on methane (CH4). The project will bridge the gap between large-scale scientific estimates from in situ monitoring programs and the 'bottom-up' estimates of emissions from local sources that are used in the national reporting by I) developing new and advanced mobile methane (CH4) measurements tools and networks, II) isotopic source identification, and III) modelling at different scales. Within the project qualified scientists will be educated in the use and implementation of interdisciplinary knowledge and techniques that are essential to meet and verify emission reduction goals. MEMO2 will facilitate intensive collaboration between the largely academic greenhouse gas monitoring community and non-academic partners who are responsible for evaluating and reporting greenhouse gas emissions to policy makers. MEMO2 is a European Training Network with more than 20 collaborators from 7 countries. It is a 4-years project and we will present the project and its objectives to the scientific community to foster

  11. Sensor Fusion Based Model for Collision Free Mobile Robot Navigation

    OpenAIRE

    Marwah Almasri; Khaled Elleithy; Abrar Alajlan

    2015-01-01

    Autonomous mobile robots have become a very popular and interesting topic in the last decade. Each of them are equipped with various types of sensors such as GPS, camera, infrared and ultrasonic sensors. These sensors are used to observe the surrounding environment. However, these sensors sometimes fail and have inaccurate readings. Therefore, the integration of sensor fusion will help to solve this dilemma and enhance the overall performance. This paper presents a collision free mobile robot...

  12. Model Fidelity Study of Dynamic Transient Loads in a Wind Turbine Gearbox: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y.; Keller, J.; Moan, T.; Xing, Y.

    2013-04-01

    Transient events cause high loads in the drivetrain components so measuring and calculating these loads can improve confidence in drivetrain design. This paper studies the Gearbox Reliability Collaborative 750kW wind turbine gearbox response during transient events using a combined experimental and modeling approach. The transient events include emergency shut-downs and start-ups measured during a field testing period in 2009. The drivetrain model is established in the multibody simulation tool Simpack. A detailed study of modeling fidelity required for accurate load prediction is performed and results are compared against measured loads. A high fidelity model that includes shaft and housing flexibility and accurate bearing stiffnesses is important for the higher-speed stage bearing loads. Each of the transient events has different modeling requirements.

  13. Expert System Models for Forecasting Forklifts Engagement in a Warehouse Loading Operation: A Case Study

    Directory of Open Access Journals (Sweden)

    Dejan Mirčetić

    2016-08-01

    Full Text Available The paper focuses on the problem of forklifts engagement in warehouse loading operations. Two expert system (ES models are created using several machine learning (ML models. Models try to mimic expert decisions while determining the forklifts engagement in the loading operation. Different ML models are evaluated and adaptive neuro fuzzy inference system (ANFIS and classification and regression trees (CART are chosen as the ones which have shown best results for the research purpose. As a case study, a central warehouse of a beverage company was used. In a beverage distribution chain, the proper engagement of forklifts in a loading operation is crucial for maintaining the defined customer service level. The created ES models represent a new approach for the rationalization of the forklifts usage, particularly for solving the problem of the forklifts engagement incargo loading. They are simple, easy to understand, reliable, and practically applicable tool for deciding on the engagement of the forklifts in a loading operation.

  14. Object Oriented Modeling of Thermostatically Controlled Devices for Cold Load Pick-up

    Directory of Open Access Journals (Sweden)

    Alexandre A. Mota

    2011-01-01

    Full Text Available Problem statement: During service restoration, the power level at buses can significantly differ from the one presented under steady-state conditions, demanding an amount of electric power significantly higher than the normal load. Hence, their post-outage behavior must be adequately forecasted in order to permit the development of reliable restoration plans, or to avoid inadequate actions that may lead to a subsequent shutdown of the electric power system. This problem is known in the literature as cold load pick-up and the thermostatically controlled loads can be pointed as the main responsible for this behavior. Approach: This study proposes a methodology to model the thermostatically controlled load behavior during the reenergization process, based on object oriented programming and the physical modeling of individual loads, avoiding the explicitly modeling of the electric distribution feeder. In this context, the load aggregation is also implemented using “feeder” classes in an hierarchical structure. Results: The methodology was tested considering distinct devices distributed along a hypothetical feeder and the results show the impacts of interruption duration and environmental temperature in the load behavior. Conclusion: The Cold-load phenomena can be successfully simulated based on physical parameters of thermostatically controlled loads using objectoriented programming, yielding satisfactory results. In special, the impacts of the environmental temperature in the load to be restored can be assessed in detail.

  15. An Optimal Mobile Service for Telecare Data Synchronization using a Role-based Access Control Model and Mobile Peer-to-Peer Technology.

    Science.gov (United States)

    Ke, Chih-Kun; Lin, Zheng-Hua

    2015-09-01

    The progress of information and communication technologies (ICT) has promoted the development of healthcare which has enabled the exchange of resources and services between organizations. Organizations want to integrate mobile devices into their hospital information systems (HIS) due to the convenience to employees who are then able to perform specific healthcare processes from any location. The collection and merage of healthcare data from discrete mobile devices are worth exploring possible ways for further use, especially in remote districts without public data network (PDN) to connect the HIS. In this study, we propose an optimal mobile service which automatically synchronizes the telecare file resources among discrete mobile devices. The proposed service enforces some technical methods. The role-based access control model defines the telecare file resources accessing mechanism; the symmetric data encryption method protects telecare file resources transmitted over a mobile peer-to-peer network. The multi-criteria decision analysis method, ELECTRE (Elimination Et Choice Translating Reality), evaluates multiple criteria of the candidates' mobile devices to determine a ranking order. This optimizes the synchronization of telecare file resources among discrete mobile devices. A prototype system is implemented to examine the proposed mobile service. The results of the experiment show that the proposed mobile service can automatically and effectively synchronize telecare file resources among discrete mobile devices. The contribution of this experiment is to provide an optimal mobile service that enhances the security of telecare file resource synchronization and strengthens an organization's mobility.

  16. A Mechanism for the Loading-Unloading Substorm Cycle Missing in MHD Global Magnetospheric Simulation Models

    Science.gov (United States)

    Klimas, A. J.; Uritsky, V.; Vassiliadis, D.; Baker, D. N.

    2005-01-01

    Loading and consequent unloading of magnetic flux is an essential element of the substorm cycle in Earth's magnetotail. We are unaware of an available global MHD magnetospheric simulation model that includes a loading- unloading cycle in its behavior. Given the central role that MHD models presently play in the development of our understanding of magnetospheric dynamics, and given the present plans for the central role that these models will play in ongoing space weather prediction programs, it is clear that this failure must be corrected. A 2-dimensional numerical driven current-sheet model has been developed that incorporates an idealized current- driven instability with a resistive MHD system. Under steady loading, the model exhibits a global loading- unloading cycle. The specific mechanism for producing the loading-unloading cycle will be discussed. It will be shown that scale-free avalanching of electromagnetic energy through the model, from loading to unloading, is carried by repetitive bursts of localized reconnection. Each burst leads, somewhat later, to a field configuration that is capable of exciting a reconnection burst again. This process repeats itself in an intermittent manner while the total field energy in the system falls. At the end of an unloading interval, the total field energy is reduced to well below that necessary to initiate the next unloading event and, thus, a loading-unloading cycle results. It will be shown that, in this model, it is the topology of bursty localized reconnection that is responsible for the appearance of the loading-unloading cycle.

  17. Residential Saudi load forecasting using analytical model and Artificial Neural Networks

    Science.gov (United States)

    Al-Harbi, Ahmad Abdulaziz

    In recent years, load forecasting has become one of the main fields of study and research. Short Term Load Forecasting (STLF) is an important part of electrical power system operation and planning. This work investigates the applicability of different approaches; Artificial Neural Networks (ANNs) and hybrid analytical models to forecast residential load in Kingdom of Saudi Arabia (KSA). These two techniques are based on model human modes behavior formulation. These human modes represent social, religious, official occasions and environmental parameters impact. The analysis is carried out on residential areas for three regions in two countries exposed to distinct people activities and weather conditions. The collected data are for Al-Khubar and Yanbu industrial city in KSA, in addition to Seattle, USA to show the validity of the proposed models applied on residential load. For each region, two models are proposed. First model is next hour load forecasting while second model is next day load forecasting. Both models are analyzed using the two techniques. The obtained results for ANN next hour models yield very accurate results for all areas while relatively reasonable results are achieved when using hybrid analytical model. For next day load forecasting, the two approaches yield satisfactory results. Comparative studies were conducted to prove the effectiveness of the models proposed.

  18. Centrifuge modelling of a laterally cyclic loaded pile

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Leth, Caspar Thrane; Hededal, Ole

    2010-01-01

    A total number of 9 static and 6 cyclic centrifuge tests on laterally loaded piles in very dense, dry sand was erformed. The prototype dimensions of the piles were 1 meter in diameter and penetration depths varying from 6 to 10 meters. The static tests were used to investigate the initial subgrade...... reaction modulus and as a reference for cyclic tests. For the cyclic tests the accumulation of deflections and the change in secant stiffness of the soil from repetitive loading were investigated. From all the tests carried out accumulations of deflections were seen. rom the centrifuge tests it was seen...

  19. Modeling and Accomplishment of Loading-and-Unloading Equipment Optimum Allocation System at Bulk Terminal

    Directory of Open Access Journals (Sweden)

    Xueping Wang

    2011-06-01

    Full Text Available The configuration of port’s loading-and-unloading equipment is an optimization problem, which endeavors to put limited handling equipment to each operating line to achieve the maximum overall production efficiency. We set up the T-stage decision-making model of loading-and-unloading line equipment configuration by using the method of Multi-stage Decision, and design the algorithm of the mathematical model. Research results in this paper lay the foundation for the development of loading-and-unloading equipment configuration system, and provide scientific basis for the decision of type selection and rational quantity of loading-and-unloading equipment.

  20. Maximum Likelihood Estimation of Time-Varying Loadings in High-Dimensional Factor Models

    DEFF Research Database (Denmark)

    Mikkelsen, Jakob Guldbæk; Hillebrand, Eric; Urga, Giovanni

    In this paper, we develop a maximum likelihood estimator of time-varying loadings in high-dimensional factor models. We specify the loadings to evolve as stationary vector autoregressions (VAR) and show that consistent estimates of the loadings parameters can be obtained by a two-step maximum...... likelihood estimation procedure. In the first step, principal components are extracted from the data to form factor estimates. In the second step, the parameters of the loadings VARs are estimated as a set of univariate regression models with time-varying coefficients. We document the finite...

  1. A Mobility and Traffic Generation Framework for Modeling and Simulating Ad Hoc Communication Networks

    Directory of Open Access Journals (Sweden)

    Chris Barrett

    2004-01-01

    Full Text Available We present a generic mobility and traffic generation framework that can be incorporated into a tool for modeling and simulating large scale ad~hoc networks. Three components of this framework, namely a mobility data generator (MDG, a graph structure generator (GSG and an occlusion modification tool (OMT allow a variety of mobility models to be incorporated into the tool. The MDG module generates positions of transceivers at specified time instants. The GSG module constructs the graph corresponding to the ad hoc network from the mobility data provided by MDG. The OMT module modifies the connectivity of the graph produced by GSG to allow for occlusion effects. With two other modules, namely an activity data generator (ADG which generates packet transmission activities for transceivers and a packet activity simulator (PAS which simulates the movement and interaction of packets among the transceivers, the framework allows the modeling and simulation of ad hoc communication networks. The design of the framework allows a user to incorporate various realistic parameters crucial in the simulation. We illustrate the utility of our framework through a comparative study of three mobility models. Two of these are synthetic models (random waypoint and exponentially correlated mobility proposed in the literature. The third model is based on an urban population mobility modeling tool (TRANSIMS developed at the Los Alamos National Laboratory. This tool is capable of providing comprehensive information about the demographics, mobility and interactions of members of a large urban population. A comparison of these models is carried out by computing a variety of parameters associated with the graph structures generated by the models. There has recently been interest in the structural properties of graphs that arise in real world systems. We examine two aspects of this for the graphs created by the mobility models: change associated with power control (range of

  2. Structural equation modelling of determinants of customer satisfaction of mobile network providers: Case of Kolkata, India

    Directory of Open Access Journals (Sweden)

    Shibashish Chakraborty

    2014-12-01

    Full Text Available The Indian market of mobile network providers is growing rapidly. India is the second largest market of mobile network providers in the world and there is intense competition among existing players. In such a competitive market, customer satisfaction becomes a key issue. The objective of this paper is to develop a customer satisfaction model of mobile network providers in Kolkata. The results indicate that generic requirements (an aggregation of output quality and perceived value, flexibility, and price are the determinants of customer satisfaction. This study offers insights for mobile network providers to understand the determinants of customer satisfaction.

  3. Future consumer mobile phone security: A case study using the data-centric security model

    NARCIS (Netherlands)

    Cleeff, van A.

    2008-01-01

    Consumer mobile phone security requires more attention, now that their data storage capacity is increasing. At the same time, much effort is spent on data-centric security for large enterprises. In this article we try to apply data-centric security to consumer mobile phones. We show a maturity model

  4. A reference model and technical framework for mobile social software for learning

    NARCIS (Netherlands)

    De Jong, Tim; Specht, Marcus; Koper, Rob

    2008-01-01

    De Jong,T., Specht, M., & Koper, R. (2008). A reference model and technical framework for mobile social software for learning. In I. A. Sánchez & P. Isaías (Eds.), Proceedings of the IADIS Mobile Learning Conference 2008 (pp. 206-210). April, 11-13, 2008, Carvoeiro, Portugal.

  5. Future consumer mobile phone security: A case study using the data-centric security model

    NARCIS (Netherlands)

    van Cleeff, A.

    Consumer mobile phone security requires more attention, now that their data storage capacity is increasing. At the same time, much effort is spent on data-centric security for large enterprises. In this article we try to apply data-centric security to consumer mobile phones. We show a maturity model

  6. Future consumer mobile phone security: A case study using the data-centric security model

    NARCIS (Netherlands)

    van Cleeff, A.

    2008-01-01

    Consumer mobile phone security requires more attention, now that their data storage capacity is increasing. At the same time, much effort is spent on data-centric security for large enterprises. In this article we try to apply data-centric security to consumer mobile phones. We show a maturity model

  7. Urban Modality: Modelling and evaluating the sustainable mobility of urban areas in the city-region

    NARCIS (Netherlands)

    Gil, J.A.

    2016-01-01

    This thesis proposes a framework for evaluating the mobility potential and performance of urban areas in the city region, as an instrument to support urban development that contributes positively to regional sustainable mobility objectives. The research takes a quantitative approach, modelling and

  8. A PANEL-DATA SWITCHING REGRESSION-MODEL OF MOBILITY AND CAR OWNERSHIP

    NARCIS (Netherlands)

    MEURS, H

    1993-01-01

    The objective of this paper is to present a panel data model of car ownership and mobility. Unobserved heterogeneity is controlled for by including correlated random effects in the equations describing car ownership and mobility. A mass-points approach is adopted to control for unobserved heterogene

  9. Analysis of Korean Students' International Mobility by 2-D Model: Driving Force Factor and Directional Factor

    Science.gov (United States)

    Park, Elisa L.

    2009-01-01

    The purpose of this study is to understand the dynamics of Korean students' international mobility to study abroad by using the 2-D Model. The first D, "the driving force factor," explains how and what components of the dissatisfaction with domestic higher education perceived by Korean students drives students' outward mobility to seek…

  10. What input data are needed to accurately model electromagnetic fields from mobile phone base stations?

    NARCIS (Netherlands)

    Beekhuizen, Johan; Kromhout, Hans; Bürgi, Alfred; Huss, Anke; Vermeulen, Roel

    2015-01-01

    The increase in mobile communication technology has led to concern about potential health effects of radio frequency electromagnetic fields (RF-EMFs) from mobile phone base stations. Different RF-EMF prediction models have been applied to assess population exposure to RF-EMF. Our study examines what

  11. Urban Modality: Modelling and evaluating the sustainable mobility of urban areas in the city-region

    NARCIS (Netherlands)

    Gil, J.A.

    2016-01-01

    This thesis proposes a framework for evaluating the mobility potential and performance of urban areas in the city region, as an instrument to support urban development that contributes positively to regional sustainable mobility objectives. The research takes a quantitative approach, modelling and m

  12. Mobile Learning Model and Process Optimization in the Era of Fragmentation

    Science.gov (United States)

    Zhang, Shi-Jun; Yu, Gui-Hua

    2017-01-01

    In the context of mobile Internet, college students' leisure time has fragmentation characteristics to improve the value of time, it is of great practical significance to make full use of fragmentation time to study effectively. This research focuses on mobile learning model and its effect, firstly, qualitative research is used to construct the…

  13. A PANEL-DATA SWITCHING REGRESSION-MODEL OF MOBILITY AND CAR OWNERSHIP

    NARCIS (Netherlands)

    MEURS, H

    1993-01-01

    The objective of this paper is to present a panel data model of car ownership and mobility. Unobserved heterogeneity is controlled for by including correlated random effects in the equations describing car ownership and mobility. A mass-points approach is adopted to control for unobserved

  14. Aeroelastic Loads Modeling for Composite Aircraft Design Support

    NARCIS (Netherlands)

    Baluch, H.A.

    2009-01-01

    With regard to the simulation of structural vibrations and consequent aeroelastic loads in aircraft components, the use of elastic axis e.a as reference of vibrations is quite common. The e.a decouples the bending and torsion degrees of freedom (D.o.F) during the dynamic analysis. The use of the e.a

  15. Aeroelastic Loads Modeling for Composite Aircraft Design Support

    NARCIS (Netherlands)

    Baluch, H.A.

    2009-01-01

    With regard to the simulation of structural vibrations and consequent aeroelastic loads in aircraft components, the use of elastic axis e.a as reference of vibrations is quite common. The e.a decouples the bending and torsion degrees of freedom (D.o.F) during the dynamic analysis. The use of the e.a

  16. Transient multiphase flow modeling of gas well liquid loading

    NARCIS (Netherlands)

    Veeken, K.; Hu, B.; Schiferli, W.

    2009-01-01

    Gas well liquid loading occurs when gas production becomes insufficient to lift the associated liquids to surface. When that happens gas production first turns intermittent and eventually stops. Hence in depleting gas reservoirs the technical abandonment pressure and ultimate recovery are typically

  17. Traffic load model based on weigh in motion measurements

    NARCIS (Netherlands)

    Steenbergen, R.D.J.M.; Morales Napoles, O.

    2012-01-01

    The assessment of the structural safety of existing bridges and viaducts becomes increasingly important in many countries. Within the actions applied to the bridges, the traffic load is, in general, the most significant variable action to be considered when the ultimate limit states are under

  18. Aeroelastic model identification of winglet loads from flight test data

    NARCIS (Netherlands)

    Reijerkerk, M.J.

    2008-01-01

    Numerical computational methods are getting more and more sophisticated every day, enabling more accurate aircraft load predictions. In the structural design of aircraft higher levels of flexibility can be tolerated to arrive at a substantial weight reduction. The result is that aircraft of the futu

  19. Modeling of dynamically loaded hydrodynamic bearings at low Sommerfeld numbers

    DEFF Research Database (Denmark)

    Thomsen, Kim

    . The challenging main bearing operation conditions in a wind turbine pose a demanding development task for the design of a hydrodynamic bearing. In general these conditions include operation at low Reynolds numbers with frequent start and stop at high loads as well as difficult operating conditions dictated...

  20. A Meta-model Describing the Development Process of Mobile Learning

    Science.gov (United States)

    Wingkvist, Anna; Ericsson, Morgan

    This paper presents a meta-model to describe the development process of mobile learning initiatives. These initiatives are often small scale trials that are not integrated in the intended setting, but carried out outside of the setting. This results in sustainability issues, i.e., problems to integrate the results of the initiative as learning aids. In order to address the sustainability issues, and in turn help to understand the scaling process, a meta-model is introduced. This meta-model divides the development into four areas of concern, and the life cycle of any mobile learning initiative into four stages. The meta-model was developed by analyzing and describing how a podcasting initiative was developed, and is currently being evaluated as a tool to both describe and evaluate mobile learning initiatives. The meta-model was developed based on a mobile learning initiative, but the meta-model itself is extendible to other forms of technology-enhanced learning.

  1. The Inclusion of Arbitrary Load Histories in the Strength Decay Model for Stress Rupture

    Science.gov (United States)

    Reeder, James R.

    2014-01-01

    Stress rupture is a failure mechanism where failures can occur after a period of time, even though the material has seen no increase in load. Carbon/epoxy composite materials have demonstrated the stress rupture failure mechanism. In a previous work, a model was proposed for stress rupture of composite overwrap pressure vessels (COPVs) and similar composite structures based on strength degradation. However, the original model was limited to constant load periods (holds) at constant load. The model was expanded in this paper to address arbitrary loading histories and specifically the inclusions of ramp loadings up to holds and back down. The broadening of the model allows for failures on loading to be treated as any other failure that may occur during testing instead of having to be treated as a special case. The inclusion of ramps can also influence the length of the "safe period" following proof loading that was previously predicted by the model. No stress rupture failures are predicted in a safe period because time is required for strength to decay from above the proof level to the lower level of loading. Although the model can predict failures during the ramp periods, no closed-form solution for the failure times could be derived. Therefore, two suggested solution techniques were proposed. Finally, the model was used to design an experiment that could detect the difference between the strength decay model and a commonly used model for stress rupture. Although these types of models are necessary to help guide experiments for stress rupture, only experimental evidence will determine how well the model may predict actual material response. If the model can be shown to be accurate, current proof loading requirements may result in predicted safe periods as long as 10(13) years. COPVs design requirements for stress rupture may then be relaxed, allowing more efficient designs, while still maintaining an acceptable level of safety.

  2. A model of rotationally-sampled wind turbulence for predicting fatigue loads in wind turbines

    Science.gov (United States)

    Spera, David A.

    1995-01-01

    Empirical equations are presented with which to model rotationally-sampled (R-S) turbulence for input to structural-dynamic computer codes and the calculation of wind turbine fatigue loads. These equations are derived from R-S turbulence data which were measured at the vertical-plane array in Clayton, New Mexico. For validation, the equations are applied to the calculation of cyclic flapwise blade loads for the NASA/DOE Mod-2 2.5-MW experimental HAWT's (horizontal-axis wind turbines), and the results compared to measured cyclic loads. Good correlation is achieved, indicating that the R-S turbulence model developed in this study contains the characteristics of the wind which produce many of the fatigue loads sustained by wind turbines. Empirical factors are included which permit the prediction of load levels at specified percentiles of occurrence, which is required for the generation of fatigue load spectra and the prediction of the fatigue lifetime of structures.

  3. Model-Based Load Estimation for Predictive Condition Monitoring of Wind Turbines

    DEFF Research Database (Denmark)

    Perisic, Nevena; Pederen, Bo Juul; Grunnet, Jacob Deleuran

    for application in condition monitoring. Fatigue loads are estimated online using a load observer and grey box models which include relevant WTG dynamics. Identification of model parameters and calibration of observer are performed offline using measurements from WTG prototype. Signal processing of estimated load...... signal is performed online, and a Load Indicator Signal (LIS) is formulated as a ratio between current estimated accumulated fatigue loads and its expected value based only on a priori knowledge (WTG dynamics and wind climate). LOT initialisation is based on a priori knowledge and can be obtained using...... a high-fidelity aero-elastic simulation code as LACflex to increase LIS rate of convergence. Additionally, statistical uncertainties in the convergence of estimated fatigue loads due to climate parameters are taken into account in the LIS function. LIS may play a central role in condition maintenance...

  4. Integration of MHD load models with circuit representations the Z generator.

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Christopher A.; Ampleford, David J.; Jones, Brent Manley; McBride, Ryan D.; Bailey, James E.; Jones, Michael C.; Gomez, Matthew Robert.; Cuneo, Michael Edward; Nakhleh, Charles; Stygar, William A.; Savage, Mark Edward; Wagoner, Timothy C.; Moore, James K.

    2013-03-01

    MHD models of imploding loads fielded on the Z accelerator are typically driven by reduced or simplified circuit representations of the generator. The performance of many of the imploding loads is critically dependent on the current and power delivered to them, so may be strongly influenced by the generators response to their implosion. Current losses diagnosed in the transmission lines approaching the load are further known to limit the energy delivery, while exhibiting some load dependence. Through comparing the convolute performance of a wide variety of short pulse Z loads we parameterize a convolute loss resistance applicable between different experiments. We incorporate this, and other current loss terms into a transmission line representation of the Z vacuum section. We then apply this model to study the current delivery to a wide variety of wire array and MagLif style liner loads.

  5. A Disruption-Tolerant Model for Building a Mobile Application Using Web Service

    Directory of Open Access Journals (Sweden)

    Maryati M. Yusof

    2010-01-01

    Full Text Available Problem statement: The emerging technology in broadband telecommunication and mobile devices has increased the use of mobile applications. However, the use of mobile application is affected with low bandwidth or disrupted broadband telecommunication due to building blockage or out of coverage area. Approach: We proposed a Disruption-Tolerant Mobile Application Model (DTMA that enables remote data access and overcomes constraint due to dysfunctional telecommunication. The interview process of Educational Service Officer at the Malaysian Educational Service Commissioner (MESC is selected as the case study. Design of the mobile application is based on the Smart Client and wireless Internet application concepts. The main components of the model are mobile devices with its own processing power, data storage, business logic and Web service. These features enable the application to become disruption-tolerant, which can be run even when communication line is not available or disrupted. In order to prove that the proposed model is effective, a prototype based on the DTMA model is developed and evaluated. Results: The prototype is known as Mobile Interview Information System (MIIS and it was developed using Visual Basic and .Net’s programming language in .NET Framework. Visual Studio is used as the platform. Users have performed MIIS testing and DTMA usability assessment in a real environment. The test showed that MIIS based on the DTMA model is disruption-tolerant. MIIS enables information to be accessed and updated even in a disrupted network. MIIS also enables information to be accessed and transmitted from or to the MESC’s headquarter via mobile devices. Further, MIIS enables the interview process to be implemented in a more efficient manner without any disruption. Conclusion: Mobile application developed based on the proposed DTMA model was proved to be disruption tolerant. Such application can save time, operational cost and

  6. Electricity demand loads modeling using AutoRegressive Moving Average (ARMA) models

    Energy Technology Data Exchange (ETDEWEB)

    Pappas, S.S. [Department of Information and Communication Systems Engineering, University of the Aegean, Karlovassi, 83 200 Samos (Greece); Ekonomou, L.; Chatzarakis, G.E. [Department of Electrical Engineering Educators, ASPETE - School of Pedagogical and Technological Education, N. Heraklion, 141 21 Athens (Greece); Karamousantas, D.C. [Technological Educational Institute of Kalamata, Antikalamos, 24100 Kalamata (Greece); Katsikas, S.K. [Department of Technology Education and Digital Systems, University of Piraeus, 150 Androutsou Srt., 18 532 Piraeus (Greece); Liatsis, P. [Division of Electrical Electronic and Information Engineering, School of Engineering and Mathematical Sciences, Information and Biomedical Engineering Centre, City University, Northampton Square, London EC1V 0HB (United Kingdom)

    2008-09-15

    This study addresses the problem of modeling the electricity demand loads in Greece. The provided actual load data is deseasonilized and an AutoRegressive Moving Average (ARMA) model is fitted on the data off-line, using the Akaike Corrected Information Criterion (AICC). The developed model fits the data in a successful manner. Difficulties occur when the provided data includes noise or errors and also when an on-line/adaptive modeling is required. In both cases and under the assumption that the provided data can be represented by an ARMA model, simultaneous order and parameter estimation of ARMA models under the presence of noise are performed. The produced results indicate that the proposed method, which is based on the multi-model partitioning theory, tackles successfully the studied problem. For validation purposes the produced results are compared with three other established order selection criteria, namely AICC, Akaike's Information Criterion (AIC) and Schwarz's Bayesian Information Criterion (BIC). The developed model could be useful in the studies that concern electricity consumption and electricity prices forecasts. (author)

  7. DEPTH-INTEGRATED MODELING FOR AGGRADING/DEGRADING MOBILE CHANNELS I: MODEL DEVELOPMENT

    Institute of Scientific and Technical Information of China (English)

    En-Tian LIN; Chih-Tsung HSU; Keh-Chia YEH

    2006-01-01

    A depth-integrated model has been developed to simulate the alluvial process of channel bed under overloading and under-loading sediment discharge conditions. The hydrodynamic sub-model based on the explicit-finite-analytic method is used to obtain the flow field. Then the sediment transport modes, including the bed-load and suspended load, are modeled with the aid of the empirically auxiliary relations. In the depth-integrated model, the sediment exchange rate is treated as a source term specified at the reference level, rather than a boundary condition as usually adopted in vertical 2-D or 3-D models. The deposition or erosion rate of the bed is then determined by comparing the flow-laden suspended-sediment concentration profile against the equilibrium concentration profile, and their difference is used to compute the sediment exchange rate for a given time interval. Assessment of the good accuracy of the proposed model is demonstrated by using van Rijn's (1981) experiment for the case of clear water passing a movable bed. In the companion paper, the verification and the field application of the proposed model are presented.

  8. Modeling and Analysis of Commercial Building Electrical Loads for Demand Side Management

    Science.gov (United States)

    Berardino, Jonathan

    In recent years there has been a push in the electric power industry for more customer involvement in the electricity markets. Traditionally the end user has played a passive role in the planning and operation of the power grid. However, many energy markets have begun opening up opportunities to consumers who wish to commit a certain amount of their electrical load under various demand side management programs. The potential benefits of more demand participation include reduced operating costs and new revenue opportunities for the consumer, as well as more reliable and secure operations for the utilities. The management of these load resources creates challenges and opportunities to the end user that were not present in previous market structures. This work examines the behavior of commercial-type building electrical loads and their capacity for supporting demand side management actions. This work is motivated by the need for accurate and dynamic tools to aid in the advancement of demand side operations. A dynamic load model is proposed for capturing the response of controllable building loads. Building-specific load forecasting techniques are developed, with particular focus paid to the integration of building management system (BMS) information. These approaches are tested using Drexel University building data. The application of building-specific load forecasts and dynamic load modeling to the optimal scheduling of multi-building systems in the energy market is proposed. Sources of potential load uncertainty are introduced in the proposed energy management problem formulation in order to investigate the impact on the resulting load schedule.

  9. An electricity price model with consideration to load and gas price effects

    Institute of Scientific and Technical Information of China (English)

    黄民翔; 陶小虎; 韩祯祥

    2003-01-01

    Some characteristics of the electricity load and prices are studied, and the relationship between electricity prices and gas (fnel) prices is analyzed in this paper. Because electricity prices are strongly depen-dent on load and gas prices, the authors constructed a model for electricity prices based on the effects of these two factors; and used the Geometric Mean Reversion Brownian Motion (GMRBM) model to describe the electricity load process, and a Geometric Brownian Motion(GBM) model to describe the gas prices ; deduced the price stochastic process model based on the above load model and gas price model. This paper also presents methods for parameters estimation, and proposes some methods to solve the model.

  10. Constitutive model of rock under static-dynamic coupling loading and experimental investigation

    Institute of Scientific and Technical Information of China (English)

    LI Xi-bing; ZUO Yu-jun; WANG Wei-hua; MA Chun-de; ZHOU Zi-long

    2006-01-01

    The importance of study on constitutive model of statically loaded rock experiencing dynamic load is set forth, and the studying methods on dynamic constitutive model are classified according to the current studying status. By way of combining statistic damage model and viscoelastic model, uni-axial and multi-axial constitutive models of statically loaded rock experiencing dynamic load (static-dynamic coupling constitutive model) under intermediate strain rate are established. The verification experiment on 2D constitutive model under different static stress and dynamic stress with different frequencies is designed and performed. It is found that there is a good agreement between the experimental stress-strain curves and the theoretical stress-strain curves.

  11. Architecture control and model identification of a Omni-Directional Mobile Robot

    OpenAIRE

    António Paulo Gomes Mendes Moreira; Paulo José Cerqueira Gomes da Costa; André Gustavo Scolari Conceição

    2005-01-01

    This paper presents a architecture control and model identification of a onmi-Directional Mobile Robot It is divided into the three stages. Stage one proposes a procedure for dynamic model identification and control of the "motor + reduction + encoder" process of the Robotapos;s Motors. Second, proposes the identification of a dynamic model for the whole mobile robot considering it as a multi-variable system. Third, presents a algorithm for perfect trajectory tracking of Omni-Directional Mobi...

  12. Modelling Feature Interaction Patterns in Nokia Mobile Phones using Coloured Petri Nets and Design/CPN

    DEFF Research Database (Denmark)

    Lorentsen, Louise; Tuovinen, Antti-Pekka; Xu, Jianli

    2002-01-01

    This paper describes the first results of a project on modelling of important feature interaction patterns of Nokia mobile phones using Coloured Petri Nets. A modern mobile phone supports many features: voice and data calls, text messaging, personal information management (phonebook and calendar....... In this paper, we look at the problem of feature interaction in the user interface of Nokia mobile phones. We present a categorization of feature interactions and describe our approach to the modelling of feature interactions using Coloured Petri Nets (CP-nets or CPN). The CPN model is extended...

  13. Context-Aware Mobile Collaborative Systems: Conceptual Modeling and Case Study

    Directory of Open Access Journals (Sweden)

    Luis G. Montané-Jiménez

    2012-10-01

    Full Text Available A Mobile Collaborative System (MCOS enable the cooperation of the members of a team to achieve a common goal by using a combination of mobile and fixed technologies. MCOS can be enhanced if the context of the group of users is considered in the execution of activities. This paper proposes a novel model for Context-Aware Mobile COllaborative Systems (CAMCOS and a functional architecture based on that model. In order to validate both the model and the architecture, a prototype system in the tourism domain was implemented and evaluated.

  14. Spatially-explicit modelling of nutrient loading to the landscape in the Great Lakes Basin

    Science.gov (United States)

    Hamlin, Q. F.; Kendall, A. D.; Martin, S. L.; Whitenack, H. D.; Hyndman, D. W.

    2016-12-01

    Loading of nitrogen and phosphorus to the landscape has resulted in dangerous algal blooms, contaminated drinking water, and decreased biodiversity. Here, we developed a GIS model to estimate spatially explicit nutrient loading across the Great Lakes Basin. The model expands on previous work in the lower peninsula of Michigan by Luscz et al. (2015). Inputs to the model include point source loads to streams along with five non-point source landscape loads: atmospheric deposition, chemical agricultural fertilizer, chemical non-agricultural fertilizer, manure application, and septic tanks. Scaling up from Michigan to the eight U.S. states and two Canadian provinces in the Great Lakes Basin provided unique challenges. In the case of the septic tank inputs, we compiled a multistate database of drinking water wells for use in an automated Python script to delineate wastewater treatment plant service areas and to estimate placement of septic tanks appropriately within the landscape. Using a model with individual nutrient inputs showed that even within a single land use class, there is high variability in loading rates. This variability suggests that simply prescribing loading estimates based on land use class is insufficient. Modelling high resolution and source specific landscape nutrient loading will be valuable to target strategies to decrease excessive anthropogenic nutrient loading in the Great Lakes Basin.

  15. Approaches to probabilistic model learning for mobile manipulation robots

    CERN Document Server

    Sturm, Jürgen

    2013-01-01

    Mobile manipulation robots are envisioned to provide many useful services both in domestic environments as well as in the industrial context. Examples include domestic service robots that implement large parts of the housework, and versatile industrial assistants that provide automation, transportation, inspection, and monitoring services. The challenge in these applications is that the robots have to function under changing, real-world conditions, be able to deal with considerable amounts of noise and uncertainty, and operate without the supervision of an expert. This book presents novel learning techniques that enable mobile manipulation robots, i.e., mobile platforms with one or more robotic manipulators, to autonomously adapt to new or changing situations. The approaches presented in this book cover the following topics: (1) learning the robot's kinematic structure and properties using actuation and visual feedback, (2) learning about articulated objects in the environment in which the robot is operating,...

  16. Mobility Management Algorithms for the Client-Driven Mobility Frame System–Mobility from a Brand New Point of View

    Directory of Open Access Journals (Sweden)

    Péter Fülöp

    2009-01-01

    Full Text Available In this paper a new mobility management is introduced. The main idea in this approach is that the mobil node should manage the mobility for itself not the network. The network nodes provide only basic services for mobile entities: connectivity and administration. We construct a framework called the Client-based Mobility Frame System (CMFS for this mobility environment. We developed the CMFS protocol as a solution over IPv4 and we show how to use Mobile IPv6 to realize our concept. We propose some basic mobility management solutions that can be implemented into the mobile clients and give details about a working simulation of a complete Mobility Management System. Example mobility management approaches such as the centralized- and hierarchical- or cellular-like ones are also defined and hints are given what kind of algorithms might be implemented upon the Client-based Mobility Frame System over IPv4 and IPv6 as well. We introduce some example algorithms that can work with the CMFS making mobility management efficient by minimizing signalling load on the network. In the present work modeling and detailed discussion on the parameters of the algorithms is given and comparison to existing mobility approaches and protocols is done. We prepared a simulation to test our protocol and to back up the proposals we provide the reader with simulation results. We stress that still one the most important benefit of our findings is that all the MNs can run different management strategies and can optimize mobility for themselves.

  17. Conceptual models for linking Drivers, Limits and Mobility

    DEFF Research Database (Denmark)

    Gudmundsson, Henrik

    attributes of mobility that are desirable for labor market productivity and society in general. Several international studies as well as practical experience suggest that solutions based on technical system improvements and infrastructure expansion may not be sufficiently effective or expedient to fully...... the setting of policy agendas to quantified fine tuning of existing policy instruments. Based on theory on policy change and knowledge utilization the paper will present a typology to classify evidence based policy advice in regard to managing mobility, and apply this typology to interpret selected research...

  18. Mobile Parallel Manipulators, Modelling and Data-Driven Motion Planning

    Directory of Open Access Journals (Sweden)

    Amar Khoukhi

    2013-11-01

    Full Text Available This paper provides a kinematic and dynamic analysis of mobile parallel manipulators (MPM. The study is conducted on a composed multi-degree of freedom (DOF parallel robot carried by a wheeled mobile platform. Both positional and differential kinematics problems for the hybrid structure are solved, and the redundancy problem is solved using joint limit secondary criterion- based generalized-pseudo-inverse. A minimum time trajectory parameterization is obtained via cycloidal profile to initialize multi-objective trajectory planning of the MPM. Considered objectives include time energy minimization redundancy resolution and singularity avoidance. Simulation results illustrating the effectiveness of the proposed approach are presented and discussed.

  19. Statistical Analysis of Baseline Load Models for Non-Residential Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Coughlin, Katie; Piette, Mary Ann; Goldman, Charles; Kiliccote, Sila

    2008-11-10

    Policymakers are encouraging the development of standardized and consistent methods to quantify the electric load impacts of demand response programs. For load impacts, an essential part of the analysis is the estimation of the baseline load profile. In this paper, we present a statistical evaluation of the performance of several different models used to calculate baselines for commercial buildings participating in a demand response program in California. In our approach, we use the model to estimate baseline loads for a large set of proxy event days for which the actual load data are also available. Measures of the accuracy and bias of different models, the importance of weather effects, and the effect of applying morning adjustment factors (which use data from the day of the event to adjust the estimated baseline) are presented. Our results suggest that (1) the accuracy of baseline load models can be improved substantially by applying a morning adjustment, (2) the characterization of building loads by variability and weather sensitivity is a useful indicator of which types of baseline models will perform well, and (3) models that incorporate temperature either improve the accuracy of the model fit or do not change it.

  20. Controlled Loading Fragmentation: Experiments and Continuum Damage Modeling

    Science.gov (United States)

    2010-07-01

    of tungsten particles in a composite nickel/ cobalt matrix. Among tungsten heavy alloys, Aerojet Ordnance Tennessee (AOT) has developed a...explosively loaded in a series of tests conducted at Eglin Air Force Base. The Aero 224 is an alloy composed of tungsten particles in a nickel/ cobalt ...main charge consisted of an aluminized PBX explosive surrounded by the metals under investigation. In both configurations the main charge was

  1. Decision Model for Life Cycle Assessment of Power Transformer during Load Violation

    Directory of Open Access Journals (Sweden)

    S. S. Bhandari

    2010-05-01

    Full Text Available Utility have normally planned the power transformer based on its designed load demand for the long term. Due to unexpected penetration, the actual load profile does not always follow the designed load and load violation will occur at some points during the life cycle of the power transformer for which the utility is inevitably required to make strategic decision. In the past, the decisions were mainly focused on the technical condition of the assetwithout any consideration to investment budget limitation. In this paper, an alternative methodology comprising of knowledge based model, financial model and decision criteria is proposed to make an optimal decision during load violation. A generic power system similar to Nepal Electricity Authority’s context was utilized as a case study. The result depicts that this model can effectively assess the life cycle of power transformer balancing both the financialand technical constraints.

  2. Varactor Modelling for Power Factor Correction in a Varying Load

    Directory of Open Access Journals (Sweden)

    Agwu D. D.

    2016-06-01

    Full Text Available : For efficient system operation, it is desirable to keep the power factor at, or very close to unity. One of the very often used methods is application of suitable power factor correction technology. Capacitors are good candidate for constant load power factor correction due to suitability and cost effectiveness. However for varying loads, synchronous condensers are preferred despite having high initial cost as a result of their being able to supply varying leading or lagging reactive power; according to their field excitation. Due to the high acquisition and operation cost of synchronous condensers, this paper presents varactors as a possible alternative for power factor correction. These are diodes that vary their capacitances and leading reactive power according to supply voltage. Applying this involves looking at variation of power factor with supply voltage; and the option of aggregating and harnessing the junction capacitance of varactors for power factor correction of varying loads at low voltage AC levels. This innovation may lead to great improvement in distribution systems requiring quality power supply

  3. A Comparison Study on Selective Traffic Models with Handoff Management Scheme for Wireless Mobile Network Infrastructure

    Directory of Open Access Journals (Sweden)

    Biswajit Bhowmik

    2013-01-01

    Full Text Available Wireless and Mobile Network Infrastructure services generally examine how different infrastructure providers are positioning themselves to compete in wireless services. These services analyze the opportunities and challenges facing by the infrastructure providers selling to wireless and mobile network operators worldwide. The opportunities and challenges are the review of strategies, market positioning, and future direction in the market for wireless and mobile network infrastructure. The service covers all generations of wireless and mobile network infrastructure: 2G, 2.5G, 3G, and 4G so on global in scope. Majority of the users are mobile while availing these services. Mobility is the most important feature of any wireless and mobile network. Usually, continuous service is achieved by supporting handoff from one cell to another. Poorly designed handoff schemes tend to generate very heavy signaling traffic and, thereby, lead to a dramatic decrease in quality of service. In this paper we make a comparison study on some selective traffic models with priority handoff scheme. The study shows how a handoff procedure has a significant impact on wireless mobile network performance on the basis of two primary criteria – Blocking probability of originating calls and the forced termination probability of ongoing calls. In addition to this the study shows arrival rate of handoff calls, and approximate number of mobile users that get serviced by underlying base station.

  4. Incorporating Mobility in Growth Modeling for Multilevel and Longitudinal Item Response Data.

    Science.gov (United States)

    Choi, In-Hee; Wilson, Mark

    2016-01-01

    Multilevel data often cannot be represented by the strict form of hierarchy typically assumed in multilevel modeling. A common example is the case in which subjects change their group membership in longitudinal studies (e.g., students transfer schools; employees transition between different departments). In this study, cross-classified and multiple membership models for multilevel and longitudinal item response data (CCMM-MLIRD) are developed to incorporate such mobility, focusing on students' school change in large-scale longitudinal studies. Furthermore, we investigate the effect of incorrectly modeling school membership in the analysis of multilevel and longitudinal item response data. Two types of school mobility are described, and corresponding models are specified. Results of the simulation studies suggested that appropriate modeling of the two types of school mobility using the CCMM-MLIRD yielded good recovery of the parameters and improvement over models that did not incorporate mobility properly. In addition, the consequences of incorrectly modeling the school effects on the variance estimates of the random effects and the standard errors of the fixed effects depended upon mobility patterns and model specifications. Two sets of large-scale longitudinal data are analyzed to illustrate applications of the CCMM-MLIRD for each type of school mobility.

  5. New model of load transfer function for pile analysis based on disturbed state model

    Institute of Scientific and Technical Information of China (English)

    LIU Qijian; YANG Linde; WU Jun

    2007-01-01

    Based on the disturbed state concept (DSC),a new model of load transfer function for pile analysis is established by the idea that the deformed material between pile and soil can be treated as a mixture of two constituent parts,which are in intact or critical state and assumed to obey random distribution.Starting from the homogenization theory of heterogeneous materials and statistics method,a parameter D to describe the disturbance degree is proposed,and a formula to determine the parameter has been derived by using the plastic displacement of a pile as distribution variable.In the model,shear intensity of elements in an intact state are simulated by Duncan-Zhang model and that in a critical state by Mohr-Coulomb criterion.The model of this paper has few parameters,which can reflect the aspects of load transfer function,such as hardening,softening and the effects of confining pressure.The well agreement between the in-situ data and the predicted shows that the validity of the model herein.So the proposed model in this paper is easy to be used in engineering practice.

  6. Simulation of the stochastic wave loads using a physical modeling approach

    DEFF Research Database (Denmark)

    Liu, W.F.; Sichani, Mahdi Teimouri; Nielsen, Søren R.K.

    2013-01-01

    an efficient way of simulating realizations of the stochastic load processes. However it requires many random variables, i.e. in the order of magnitude of 1000, to be included in the load model. Unfortunately having too many random variables in the problem makes considerable difficulties in analyzing system...

  7. 78 FR 13874 - Watershed Modeling To Assess the Sensitivity of Streamflow, Nutrient, and Sediment Loads to...

    Science.gov (United States)

    2013-03-01

    ... AGENCY Watershed Modeling To Assess the Sensitivity of Streamflow, Nutrient, and Sediment Loads to... Streamflow, Nutrient, and Sediment Loads to Climate Change and Urban Development in 20 U.S. Watersheds (EPA... and Development and is intended to characterize the sensitivity of streamflow, nutrient (nitrogen and...

  8. Stakeholder Models for Social and Mobile Media CSR Projects

    DEFF Research Database (Denmark)

    Kampf, Constance Elizabeth

    2014-01-01

    This paper is intended to demonstrate current uses of smartphone and social media technology by consumers. The three cases discussed show ways in which consumers have built communities through social and mobile media for a range of purposes—1) to organize their purchasing activities to get busine...

  9. [A mobile reanimation model (reanimationmobile) for initial newborn infant care].

    Science.gov (United States)

    Lang, N; Hansmann, M; Niesen, M

    1976-12-01

    A mobile unit for reanimation of the newborn is reported to be used alternatively in the deliveryroom or in the surgical tract. The following adventages are achieved: a large working plate easily accessible from three sides, a complete and variable instrumentation, an efficent warmth supply and the possibility for easy cleaning and desinfection.

  10. Stakeholder Models for Social and Mobile Media CSR Projects

    DEFF Research Database (Denmark)

    Kampf, Constance Elizabeth

    2014-01-01

    This paper is intended to demonstrate current uses of smartphone and social media technology by consumers. The three cases discussed show ways in which consumers have built communities through social and mobile media for a range of purposes—1) to organize their purchasing activities to get busine...... and mobile media to address strategy issues with businesses. Thus, these cases reveal a technology-enabled blurring of the boundaries between companies and their stakeholders through consumers' actions.......This paper is intended to demonstrate current uses of smartphone and social media technology by consumers. The three cases discussed show ways in which consumers have built communities through social and mobile media for a range of purposes—1) to organize their purchasing activities to get...... have built up an increasingly global presence since their founding in 2007-2008. Given the longevity of these organizations, which are still operating in 2012, their versions of CSR, and the internet presences they have built up, these cases demonstrate examples of consumers mobilizing through social...

  11. Wavelet time series MPARIMA modeling for power system short term load forecasting

    Institute of Scientific and Technical Information of China (English)

    冉启文; 单永正; 王建赜; 王骐

    2003-01-01

    The wavelet power system short term load forecasting(STLF) uses a mulriple periodical autoregressive integrated moving average(MPARIMA) model to model the mulriple near-periodicity, nonstationarity and nonlinearity existed in power system short term quarter-hour load time series, and can therefore accurately forecast the quarter-hour loads of weekdays and weekends, and provide more accurate results than the conventional techniques, such as artificial neural networks and autoregressive moving average(ARMA) models test results. Obtained with a power system networks in a city in Northeastern part of China confirm the validity of the approach proposed.

  12. Physical scale modeling of single free head piles under lateral loading in cohesive soils

    Directory of Open Access Journals (Sweden)

    Edgar Leonardo Salamanca-Medina

    2017-06-01

    Full Text Available This paper presents the results of the small scale modeling of free head wood piles under horizontal loading in cohesive soils, tested in order to compare the results with analytical models proposed by various authors. Characteristic Load (CLM and P-Y Curves methods were used for the prediction of lateral deflections at the head of the piles and the method proposed by Broms for estimating the ultimate lateral load. These predictions were compared with the results of the physical modeling, obtaining a good approximation between them.

  13. Elysium region, Mars - Tests of lithospheric loading models for the formation of tectonic features

    Science.gov (United States)

    Hall, J. Lynn; Solomon, Sean C.; Head, James W.

    1986-01-01

    The hypothesis that the tectonic features in the Elysium region are the product of stress produced by loading of the Martian lithosphere is tested. The lithospheric loading models for the formation of tectonic features in the Elysium region are evaluated under local loading, regional loading of the lithosphere from above and below, and quasi-global loading by Tharsis. The physiographic features in the Elysium region are described. The stress fields predicted by volcanic loading and uplift of the Martian lithosphere are compared with the tectonic features in the Elysium region. It is noted that the comparison suggests the succession of stress fields operating at different times in the region and supports the hypothesis.

  14. Applying the Rasch Model to Measure Mobility of Women: A Comparative Analysis of Mobility of Informal Workers in Fisheries in Kerala, India.

    Science.gov (United States)

    Menon, Nikhila

    2016-01-01

    Mobility or freedom and ability to move is gendered in many cultural contexts. In this paper I analyse mobility associated with work from the capability approach perspective of Sen. This is an empirical paper which uses the Rasch Rating Scale Model (RSM) to construct the measure of mobility of women for the first time in the development studies discourse. I construct a measure of mobility (latent trait) of women workers engaged in two types of informal work, namely, peeling work and fish vending, in fisheries in the cultural context of India. The scale measure enables first, to test the unidimensionality of my construct of mobility of women and second, to analyse the domains of mobility of women workers. The comparative analysis of the scale of permissibility of mobility constructed using the RSM for the informal women workers shows that women face constraints on mobility in social and personal spaces in the socially advanced state of Kerala in India. Work mobility does not expand the real freedoms, hence work mobility can be termed as bounded capability which is a capability limited or bounded by either the social, cultural and gender norms or a combination of all of these. Therefore at the macro level, growth in informal employment in sectors like fisheries which improve mobility of women through work mobility does not necessarily expand the capability sets by contributing to greater freedoms and transformational mobility. This paper has a significant methodological contribution in that it uses an innovative method for the measurement of mobility of women in the development studies discipline.

  15. Modeling and Depletion Simulations for a High Flux Isotope Reactor Cycle with a Representative Experiment Loading

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Betzler, Ben [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Hirtz, Gregory John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Ilas, Germina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Sunny, Eva [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division

    2016-09-01

    The purpose of this report is to document a high-fidelity VESTA/MCNP High Flux Isotope Reactor (HFIR) core model that features a new, representative experiment loading. This model, which represents the current, high-enriched uranium fuel core, will serve as a reference for low-enriched uranium conversion studies, safety-basis calculations, and other research activities. A new experiment loading model was developed to better represent current, typical experiment loadings, in comparison to the experiment loading included in the model for Cycle 400 (operated in 2004). The new experiment loading model for the flux trap target region includes full length 252Cf production targets, 75Se production capsules, 63Ni production capsules, a 188W production capsule, and various materials irradiation targets. Fully loaded 238Pu production targets are modeled in eleven vertical experiment facilities located in the beryllium reflector. Other changes compared to the Cycle 400 model are the high-fidelity modeling of the fuel element side plates and the material composition of the control elements. Results obtained from the depletion simulations with the new model are presented, with a focus on time-dependent isotopic composition of irradiated fuel and single cycle isotope production metrics.

  16. A Device Model for Polymer Light-Emitting Diodes with Mobile Ions

    NARCIS (Netherlands)

    Jong, M.J.M. de; Blom, P.W.M.

    1996-01-01

    A model is presented for the device operation of a polymer light-emitting diode (PLED) with mobile ions. It is calculated that the low efficiency of a PLED with a high injection barrier increases as the ions migrate.

  17. Formal and Executable Specification of Random Waypoint Mobility Model Using Timed Coloured Petri Nets for WMN

    Directory of Open Access Journals (Sweden)

    Naeem Akhtar Khan

    2014-01-01

    Full Text Available The wireless mesh network (WMN is an emerging and cost-effective alternative paradigm for the next generation wireless networks in many diverse applications. In the performance evaluation of routing protocol for the WMN, it is essential that it should be evaluated under realistic conditions. The usefulness of specific mobility protocol can be determined by selection of mobility model. This paper introduces a coloured Petri nets (CP-nets based formal model for implementation, simulation, and analysis of most widely used random waypoint (RWP mobility model for WMNs. The formal semantics of hierarchical timed CP-nets allow us to investigate the terminating behavior of the transitions using state space analysis techniques. The proposed implementation improves the RWP mobility model by removing the “border effect” and resolves the “speed decay” problem.

  18. A reference model and technical framework for mobile social software for learning

    NARCIS (Netherlands)

    De Jong, Tim; Specht, Marcus; Koper, Rob

    2008-01-01

    De Jong, T., Specht, M., & Koper, R. (2008). A reference model and technical framework for mobile social software for learning. Presented at the IADIS m-learning 2008 Conference. April, 11-13, 2008, Carvoeiro, Portugal.

  19. Using cloud models of heartbeats as the entity identifier to secure mobile devices.

    Science.gov (United States)

    Fu, Donglai; Liu, Yanhua

    2017-01-01

    Mobile devices are extensively used to store more private and often sensitive information. Therefore, it is important to protect them against unauthorised access. Authentication ensures that authorised users can use mobile devices. However, traditional authentication methods, such as numerical or graphic passwords, are vulnerable to passive attacks. For example, an adversary can steal the password by snooping from a shorter distance. To avoid these problems, this study presents a biometric approach that uses cloud models of heartbeats as the entity identifier to secure mobile devices. Here, it is identified that these concepts including cloud model or cloud have nothing to do with cloud computing. The cloud model appearing in the study is the cognitive model. In the proposed method, heartbeats are collected by two ECG electrodes that are connected to one mobile device. The backward normal cloud generator is used to generate ECG standard cloud models characterising the heartbeat template. When a user tries to have access to their mobile device, cloud models regenerated by fresh heartbeats will be compared with ECG standard cloud models to determine if the current user can use this mobile device. This authentication method was evaluated from three aspects including accuracy, authentication time and energy consumption. The proposed method gives 86.04% of true acceptance rate with 2.73% of false acceptance rate. One authentication can be done in 6s, and this processing consumes about 2000 mW of power.

  20. Valiant load-balanced robust routing under hose model for WDM mesh networks

    Science.gov (United States)

    Zhang, Xiaoning; Li, Lemin; Wang, Sheng

    2006-09-01

    In this paper, we propose Valiant Load-Balanced robust routing scheme for WDM mesh networks under the model of polyhedral uncertainty (i.e., hose model), and the proposed routing scheme is implemented with traffic grooming approach. Our Objective is to maximize the hose model throughput. A mathematic formulation of Valiant Load-Balanced robust routing is presented and three fast heuristic algorithms are also proposed. When implementing Valiant Load-Balanced robust routing scheme to WDM mesh networks, a novel traffic-grooming algorithm called MHF (minimizing hop first) is proposed. We compare the three heuristic algorithms with the VPN tree under the hose model. Finally we demonstrate in the simulation results that MHF with Valiant Load-Balanced robust routing scheme outperforms the traditional traffic-grooming algorithm in terms of the throughput for the uniform/non-uniform traffic matrix under the hose model.

  1. Hierarchical models for failure analysis of plates bent by distributed and localized transverse loadings

    Institute of Scientific and Technical Information of China (English)

    Erasmo CARRERA; Gaetano GIUNTA

    2008-01-01

    The failure analysis of simply supported, isotropic, square plates is addressed. Attention focuses on minimum failure load amplitudes and failure locations, von Mises' equivalent stress along the plate thickness is also addressed. Several distributed and localized loading conditions are considered. Loads act on the top of the plate. Bi-sinusoidal and uniform loads are taken into account for distributed loadings, while stepwise constant centric and off-centric loadings are addressed in the case of localized loadings. Analysis is performed considering plates whose length-to-thickness ratio a/h can be as high as 100 (thin plates) and as low as 2 (very thick plates). Results are obtained via several 2D plate models. Classical theories (CTs) and higher order models are applied. Those theories are based on polynomial approximation of the displacement field. Among the higher order theories (HOTs), HOTsd models account for the transverse shear deformations, while HOTs models account for both transverse shear and transverse normal deformations. LHOTs represent a local application of the higher order theories. A layerwise approach is thus assumed: by means of mathematical interfaces, the plate is considered to be made of several fictitious layers. The exact 3D solution is presented in order to determine the accuracy of the results obtained via the 2D models. In this way a hierarchy among the 2D theories is established. CTs provide highly accurate results for a/h greater than 10 in the case of distributed loadings and greater than 20 for localized Ioadings. Results obtained via HOTs are highly accurate in the case of very thick plates for bi-sinusoidal and centric loadings. In the case of uniform and off-centric loadings a high gradient is present in the neighborhood of the plate top. In those cases, LHOTs yield results that match the exact solution.

  2. Optimization of small portable hoist load-capacity model

    Science.gov (United States)

    Tang, Yuanheng; Yin, Hao; Liang, Zuotang; Xu, Cheng

    2017-04-01

    Small Portable Hoist (SPH) is needed in many special occasions; the load-capacity (LC) is one of the most important metrics. There are few researches direct related on SPH and the LC is calculated by Euler's formula in most published related literatures. Because of the SPH's unique, experimental research is carried out on the LC, an optimization of Euler's formula is got by analyzing the effects of wrap angle φ, end tension FB, and relative size of r and R. This optimization is more accurate and it deepens the understanding of the friction between wheel and the bending rope.

  3. The relationships between internal and external training load models during basketball training.

    Science.gov (United States)

    Scanlan, Aaron T; Wen, Neal; Tucker, Patrick S; Dalbo, Vincent J

    2014-09-01

    The present investigation described and compared the internal and external training loads during basketball training. Eight semiprofessional male basketball players (mean ± SD, age: 26.3 ± 6.7 years; stature: 188.1 ± 6.2 cm; body mass: 92.0 ± 13.8 kg) were monitored across a 7-week period during the preparatory phase of the annual training plan. A total of 44 total sessions were monitored. Player session ratings of perceived exertion (sRPE), heart rate, and accelerometer data were collected across each training session. Internal training load was determined using the sRPE, training impulse (TRIMP), and summated-heart-rate-zones (SHRZ) training load models. External training load was calculated using an established accelerometer algorithm. Pearson product-moment correlations with 95% confidence intervals (CIs) were used to determine the relationships between internal and external training load models. Significant moderate relationships were observed between external training load and the sRPE (r42 = 0.49, 95% CI = 0.23-0.69, p basketball settings. Basketball coaching and conditioning professionals should not assume a linear dose-response between accelerometer and internal training load models during training and are recommended to combine internal and external approaches when monitoring training load in players.

  4. Finite element analysis to characterize how varying patellar loading influences pressure applied to cartilage: model evaluation.

    Science.gov (United States)

    Shah, Kushal S; Saranathan, Archana; Koya, Bharath; Elias, John J

    2015-01-01

    A finite element analysis (FEA) modeling technique has been developed to characterize how varying the orientation of the patellar tendon influences the patellofemoral pressure distribution. To evaluate the accuracy of the technique, models were created from MRI images to represent five knees that were previously tested in vitro to determine the influence of hamstrings loading on patellofemoral contact pressures. Hamstrings loading increased the lateral and posterior orientation of the patellar tendon. Each model was loaded at 40°, 60°, and 80° of flexion with quadriceps force vectors representing the experimental loading conditions. The orientation of the patellar tendon was represented for the loaded and unloaded hamstrings conditions based on experimental measures of tibiofemoral alignment. Similar to the experimental data, simulated loading of the hamstrings within the FEA models shifted the center of pressure laterally and increased the maximum lateral pressure. Significant (p pressure and maximum lateral pressure from paired t-tests carried out at the individual flexion angles. The ability to replicate experimental trends indicates that the FEA models can be used for future studies focused on determining how variations in the orientation of the patellar tendon related to anatomical or loading variations or surgical procedures influence the patellofemoral pressure distribution.

  5. Load history-based model for prestressed concrete beam damage evaluation

    Institute of Scientific and Technical Information of China (English)

    Yuan Jianli; Wang Yi; Qian Zhonghui

    2007-01-01

    The residual capability of a damaged structure to resist further load is essential in optimal seismic design and post-earthquake strengthening.An experimental study on the hysteretic characteristics of prestressed concrete frame beams under different loading histories was performed to explore the influence of load history on energy dissipation and failure characteristics of the member.Based on the test results,the failure of the beam is defined,and the relationship between the failure moment under cyclic load and from the skeleton curve is formulated.Finally,based on displacement and energy dissipation,a model for prestressed concrete beam damage-failure evaluation is developed.In this model,the effect of deformation level,cumulative dissipated energy,and loading history on prestressed concrete beam damage-failure is incorporated,thus it is applicable to stochastic earthquake forces.

  6. Hop-by-HopWorm Propagation with Carryover Epidemic Model in Mobile Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jun-Won Ho

    2015-10-01

    Full Text Available In the internet, a worm is usually propagated in a random multi-hop contact manner. However, the attacker will not likely select this random multi-hop propagation approach in a mobile sensor network. This is because multi-hop worm route paths to random vulnerable targets can be often breached due to node mobility, leading to failure of fast worm spread under this strategy. Therefore, an appropriate propagation strategy is needed for mobile sensor worms. To meet this need, we discuss a hop-by-hop worm propagation model in mobile sensor networks. In a hop-by-hop worm propagation model, benign nodes are infected by worm in neighbor-to-neighbor spread manner. Since worm infection occurs in hop-by-hop contact, it is not substantially affected by a route breach incurred by node mobility. We also propose the carryover epidemic model to deal with the worm infection quota deficiency that might occur when employing an epidemic model in a mobile sensor network. We analyze worm infection capability under the carryover epidemic model. Moreover, we simulate hop-by-hop worm propagation with carryover epidemic model by using an ns-2 simulator. The simulation results demonstrate that infection quota carryovers are seldom observed where a node’s maximum speed is no less than 20 m/s.

  7. Improving Network Performance with Affinity based Mobility Model in Opportunistic Network

    CERN Document Server

    Batabyal, Suvadip; 10.5121/ijwmn.2012.4213

    2012-01-01

    Opportunistic network is a type of Delay Tolerant Network which is characterized by intermittent connectivity amongst the nodes and communication largely depends upon the mobility of the participating nodes. The network being highly dynamic, traditional MANET protocols cannot be applied and the nodes must adhere to store-carry-forward mechanism. Nodes do not have the information about the network topology, number of participating nodes and the location of the destination node. Hence, message transfer reliability largely depends upon the mobility pattern of the nodes. In this paper we have tried to find the impact of RWP (Random Waypoint) mobility on packet delivery ratio. We estimate mobility factors like number of node encounters, contact duration(link time) and inter-contact time which in turn depends upon parameters like playfield area (total network area), number of nodes, node velocity, bit-rate and RF range of the nodes. We also propose a restricted form of RWP mobility model, called the affinity based ...

  8. A very simple dynamic soil acidification model for scenario analyses and target load calculations

    NARCIS (Netherlands)

    Posch, M.; Reinds, G.J.

    2009-01-01

    A very simple dynamic soil acidification model, VSD, is described, which has been developed as the simplest extension of steady-state models for critical load calculations and with an eye on regional applications. The model requires only a minimum set of inputs (compared to more detailed models) and

  9. Propagation Modeling and Defending of a Mobile Sensor Worm in Wireless Sensor and Actuator Networks

    Science.gov (United States)

    Wang, Tian; Wu, Qun; Wen, Sheng; Cai, Yiqiao; Tian, Hui; Chen, Yonghong; Wang, Baowei

    2017-01-01

    WSANs (Wireless Sensor and Actuator Networks) are derived from traditional wireless sensor networks by introducing mobile actuator elements. Previous studies indicated that mobile actuators can improve network performance in terms of data collection, energy supplementation, etc. However, according to our experimental simulations, the actuator’s mobility also causes the sensor worm to spread faster if an attacker launches worm attacks on an actuator and compromises it successfully. Traditional worm propagation models and defense strategies did not consider the diffusion with a mobile worm carrier. To address this new problem, we first propose a microscopic mathematical model to describe the propagation dynamics of the sensor worm. Then, a two-step local defending strategy (LDS) with a mobile patcher (a mobile element which can distribute patches) is designed to recover the network. In LDS, all recovering operations are only taken in a restricted region to minimize the cost. Extensive experimental results demonstrate that our model estimations are rather accurate and consistent with the actual spreading scenario of the mobile sensor worm. Moreover, on average, the LDS outperforms other algorithms by approximately 50% in terms of the cost. PMID:28098748

  10. Propagation Modeling and Defending of a Mobile Sensor Worm in Wireless Sensor and Actuator Networks.

    Science.gov (United States)

    Wang, Tian; Wu, Qun; Wen, Sheng; Cai, Yiqiao; Tian, Hui; Chen, Yonghong; Wang, Baowei

    2017-01-13

    WSANs (Wireless Sensor and Actuator Networks) are derived from traditional wireless sensor networks by introducing mobile actuator elements. Previous studies indicated that mobile actuators can improve network performance in terms of data collection, energy supplementation, etc. However, according to our experimental simulations, the actuator's mobility also causes the sensor worm to spread faster if an attacker launches worm attacks on an actuator and compromises it successfully. Traditional worm propagation models and defense strategies did not consider the diffusion with a mobile worm carrier. To address this new problem, we first propose a microscopic mathematical model to describe the propagation dynamics of the sensor worm. Then, a two-step local defending strategy (LDS) with a mobile patcher (a mobile element which can distribute patches) is designed to recover the network. In LDS, all recovering operations are only taken in a restricted region to minimize the cost. Extensive experimental results demonstrate that our model estimations are rather accurate and consistent with the actual spreading scenario of the mobile sensor worm. Moreover, on average, the LDS outperforms other algorithms by approximately 50% in terms of the cost.

  11. Analytical model of carrier mobility in a Polymer Field Effect Transistor

    Directory of Open Access Journals (Sweden)

    Milošević Milan M.

    2007-01-01

    Full Text Available In this paper, the carrier mobility analytical model in a POFET (Polymer Field Effect Transistor channel is proposed. The model was developed on the basis of existing models and experimental results. The proposed model is universal because it encompasses the carrier mobility dependence on temperature, electric field and trap density in the POFET channel. The model is comparatively simple, easy for application and gives valuable results. According to the presented model, simulations of mobility as a function of the parameters of interest were performed. The obtained results are shown graphically. In comparison to accessible experimental results excellent correspondence was found. This model enables the calculation of simple POFET current-voltage I (V characteristics.

  12. Mobile-PKI Service Model for Ubiquitous Environment

    Science.gov (United States)

    Jeun, Inkyung; Chun, Kilsoo

    One of the most important things in PKI(Public Key Infrastructure) is the private key management issue. The private key must be deal with safely for secure PKI service. Even though PKI service is usually used for identification and authentication of user in e-commerce, PKI service has many inconvenient factors. Especially, the fact that storage media of private key for PKI service is limited to PC hard disk drive or smart card users must always carry, gives an inconvenience to user and is not suitable in ubiquitous network. This paper suggests the digital signature service using a mobile phone(m-PKI service) which is suitable in future network. A mobile phone is the most widely used for personal communication means and has a characteristic of high movability. We can use the PKI service anytime and anywhere using m-PKI.

  13. Learning to Automatically Detect Features for Mobile Robots Using Second-Order Hidden Markov Models

    Directory of Open Access Journals (Sweden)

    Olivier Aycard

    2004-12-01

    Full Text Available In this paper, we propose a new method based on Hidden Markov Models to interpret temporal sequences of sensor data from mobile robots to automatically detect features. Hidden Markov Models have been used for a long time in pattern recognition, especially in speech recognition. Their main advantages over other methods (such as neural networks are their ability to model noisy temporal signals of variable length. We show in this paper that this approach is well suited for interpretation of temporal sequences of mobile-robot sensor data. We present two distinct experiments and results: the first one in an indoor environment where a mobile robot learns to detect features like open doors or T-intersections, the second one in an outdoor environment where a different mobile robot has to identify situations like climbing a hill or crossing a rock.

  14. Learning to Automatically Detect Features for Mobile Robots Using Second-Order Hidden Markov Models

    Directory of Open Access Journals (Sweden)

    Richard Washington

    2008-11-01

    Full Text Available In this paper, we propose a new method based on Hidden Markov Models to interpret temporal sequences of sensor data from mobile robots to automatically detect features. Hidden Markov Models have been used for a long time in pattern recognition, especially in speech recognition. Their main advantages over other methods (such as neural networks are their ability to model noisy temporal signals of variable length. We show in this paper that this approach is well suited for interpretation of temporal sequences of mobile-robot sensor data. We present two distinct experiments and results: the first one in an indoor environment where a mobile robot learns to detect features like open doors or T- intersections, the second one in an outdoor environment where a different mobile robot has to identify situations like climbing a hill or crossing a rock.

  15. Determining critical load in the multispan beams with the nonlinear model

    Science.gov (United States)

    DemÑ-r, D. Dönmez; Sinir, B. G.; Usta, L.

    2017-01-01

    The beams which are one of the most commonly used structural members are quite important for many researchers. Mathematical models determining the response of beams under external loads are concluded from elasticity theory through a series of assumptions concerning the kinematics of deformation and constitutive behavior. In this study, the derivation of the nonlinear model is introduced to determine the critical load in the multispan beams. Since the engineering practice of this kind of problems is very common, determining the critical load is quite important. For this purpose, the nonlinear mathematical model of the multispan Euler-Bernoulli beam is firstly obtained. To be able to obtain the independent of the material and the geometry, the present model are became dimensionless. Then, the critical axial load can be determined via the nonlinear solution of the governing equation.

  16. Trimming Behavior of H_2-Loaded Silica Fiber Modeled by Rate Equations

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Photosensitivity behavior of H2-loaded silica fiber was modeled by rate equations for activated particles. The theoretical deductions give a close explanation to experimental phenomena on post-exposure growth in fiber gratings.

  17. Improving regression-model-based streamwater constituent load estimates derived from serially correlated data

    Science.gov (United States)

    Aulenbach, Brent T.

    2013-10-01

    A regression-model based approach is a commonly used, efficient method for estimating streamwater constituent load when there is a relationship between streamwater constituent concentration and continuous variables such as streamwater discharge, season and time. A subsetting experiment using a 30-year dataset of daily suspended sediment observations from the Mississippi River at Thebes, Illinois, was performed to determine optimal sampling frequency, model calibration period length, and regression model methodology, as well as to determine the effect of serial correlation of model residuals on load estimate precision. Two regression-based methods were used to estimate streamwater loads, the Adjusted Maximum Likelihood Estimator (AMLE), and the composite method, a hybrid load estimation approach. While both methods accurately and precisely estimated loads at the model's calibration period time scale, precisions were progressively worse at shorter reporting periods, from annually to monthly. Serial correlation in model residuals resulted in observed AMLE precision to be significantly worse than the model calculated standard errors of prediction. The composite method effectively improved upon AMLE loads for shorter reporting periods, but required a sampling interval of at least 15-days or shorter, when the serial correlations in the observed load residuals were greater than 0.15. AMLE precision was better at shorter sampling intervals and when using the shortest model calibration periods, such that the regression models better fit the temporal changes in the concentration-discharge relationship. The models with the largest errors typically had poor high flow sampling coverage resulting in unrepresentative models. Increasing sampling frequency and/or targeted high flow sampling are more efficient approaches to ensure sufficient sampling and to avoid poorly performing models, than increasing calibration period length.

  18. Mobilities Mobilities

    Directory of Open Access Journals (Sweden)

    César Pompeyo

    2011-12-01

    Full Text Available Urry, John (2007 Mobilities.Oxford: Polity Press.Urry, John (2007 Mobilities.Oxford: Polity Press.John Urry (1946-, profesor en la Universidad de Lancaster, es un sociólogo de sobra conocido y altamente reputado en el panorama internacional de las ciencias sociales. Su dilatada carrera, aparentemente dispersa y diversificada, ha seguido senderos bastante bien definidos dejando tras de sí un catálogo extenso de obras sociológicas de primer nivel. Sus primeros trabajos se centraban en el campo de la teoría social y la filosofía de las ciencias sociales o de la sociología del poder [...

  19. Flying Ad-Hoc Networks: Routing Protocols, Mobility Models, Issues

    OpenAIRE

    Muneer Bani Yassein; “Nour Alhuda” Damer

    2016-01-01

    Flying Ad-Hoc Networks (FANETs) is a group of Unmanned Air Vehicles (UAVs) which completed their work without human intervention. There are some problems in this kind of networks: the first one is the communication between (UAVs). Various routing protocols introduced classified into three categories, static, proactive, reactive routing protocols in order to solve this problem. The second problem is the network design, which depends on the network mobility, in which is the process of cooperati...

  20. Peer-to-peer model for the area coverage and cooperative control of mobile sensor networks

    Science.gov (United States)

    Tan, Jindong; Xi, Ning

    2004-09-01

    This paper presents a novel model and distributed algorithms for the cooperation and redeployment of mobile sensor networks. A mobile sensor network composes of a collection of wireless connected mobile robots equipped with a variety of sensors. In such a sensor network, each mobile node has sensing, computation, communication, and locomotion capabilities. The locomotion ability enhances the autonomous deployment of the system. The system can be rapidly deployed to hostile environment, inaccessible terrains or disaster relief operations. The mobile sensor network is essentially a cooperative multiple robot system. This paper first presents a peer-to-peer model to define the relationship between neighboring communicating robots. Delaunay Triangulation and Voronoi diagrams are used to define the geometrical relationship between sensor nodes. This distributed model allows formal analysis for the fusion of spatio-temporal sensory information of the network. Based on the distributed model, this paper discusses a fault tolerant algorithm for autonomous self-deployment of the mobile robots. The algorithm considers the environment constraints, the presence of obstacles and the nonholonomic constraints of the robots. The distributed algorithm enables the system to reconfigure itself such that the area covered by the system can be enlarged. Simulation results have shown the effectiveness of the distributed model and deployment algorithms.

  1. Loading Processes Dynamics Modelling Taking into Account the Bucket-Soil Interaction

    Directory of Open Access Journals (Sweden)

    Carmen Debeleac

    2007-10-01

    Full Text Available The author propose three dynamic models specialized for the vibrations and resistive forces analysis that appear at the loading process with different construction equipment like frontal loaders and excavators.The models used putting into evidence the components of digging: penetration, cutting, and loading.The conclusions of this study consist by evidentiate the dynamic overloads that appear on the working state and that induced the self-oscillations into the equipment structure.

  2. Simplified rotor load models and fatigue damage estimates for offshore wind turbines.

    Science.gov (United States)

    Muskulus, M

    2015-02-28

    The aim of rotor load models is to characterize and generate the thrust loads acting on an offshore wind turbine. Ideally, the rotor simulation can be replaced by time series from a model with a few parameters and state variables only. Such models are used extensively in control system design and, as a potentially new application area, structural optimization of support structures. Different rotor load models are here evaluated for a jacket support structure in terms of fatigue lifetimes of relevant structural variables. All models were found to be lacking in accuracy, with differences of more than 20% in fatigue load estimates. The most accurate models were the use of an effective thrust coefficient determined from a regression analysis of dynamic thrust loads, and a novel stochastic model in state-space form. The stochastic model explicitly models the quasi-periodic components obtained from rotational sampling of turbulent fluctuations. Its state variables follow a mean-reverting Ornstein-Uhlenbeck process. Although promising, more work is needed on how to determine the parameters of the stochastic model and before accurate lifetime predictions can be obtained without comprehensive rotor simulations.

  3. Modeling on the Effect of Coal Loads on Kinetic Energy of Balls for Ball Mills

    Directory of Open Access Journals (Sweden)

    Yan Bai

    2015-07-01

    Full Text Available This paper presents a solution for the detection and control of coal loads that is more accurate and convenient than those currently used. To date, no research has addressed the use of a grinding medium as the controlled parameter. To improve the accuracy of the coal load detection based on the kinetic energy of balls in a tubular ball mill, a Discrete Element Method (DEM model for ball kinematics based on coal loads is proposed. The operating process for a ball mill and the ball motion, as influenced by the coal quality and the coal load, was analyzed carefully. The relationship between the operating efficiency of a coal pulverizing system, coal loads, and the balls’ kinetic energy was obtained. Origin and Matlab were utilized to draw the variation of parameters with increasing coal loads in the projectile and cascading motion states. The parameters include the balls’ real-time kinetic energy, the friction energy consumption, and the mill’s total work. Meanwhile, a method of balanced adjacent degree and a physical experiment were proposed to verify the considerable effect of the balls’ kinetic energy on coal loads. The model and experiment results indicate that a coal load control method based on the balls’ kinetic energy is therefore feasible for the optimized operation of a coal pulverizing system.

  4. Design And Modeling An Automated Digsilent Power System For Optimal New Load Locations

    Directory of Open Access Journals (Sweden)

    Mohamed Saad

    2015-08-01

    Full Text Available Abstract The electric power utilities seek to take advantage of novel approaches to meet growing energy demand. Utilities are under pressure to evolve their classical topologies to increase the usage of distributed generation. Currently the electrical power engineers in many regions of the world are implementing manual methods to measure power consumption for farther assessment of voltage violation. Such process proved to be time consuming costly and inaccurate. Also demand response is a grid management technique where retail or wholesale customers are requested either electronically or manually to reduce their load. Therefore this paper aims to design and model an automated power system for optimal new load locations using DPL DIgSILENT Programming Language. This study is a diagnostic approach that assists system operator about any voltage violation cases that would happen during adding new load to the grid. The process of identifying the optimal bus bar location involves a complicated calculation of the power consumptions at each load bus As a result the DPL program would consider all the IEEE 30 bus internal networks data then a load flow simulation will be executed. To add the new load to the first bus in the network. Therefore the developed model will simulate the new load at each available bus bar in the network and generate three analytical reports for each case that captures the overunder voltage and the loading elements among the grid.

  5. MODELING OF THE SNOW LOAD ON THE ROOFS OF INDUSTRIAL BUILDINGS

    Directory of Open Access Journals (Sweden)

    Zolina Tat’yana Vladimirovna

    2016-08-01

    Full Text Available When designing load-bearing framework structures using the method of limiting states it is necessary to determine the maximum possible value of snow load for the entire period of operation of an industrial building for the possibility of transition. The magnitude of the snow load is randomly changed over the time, and therefore the most appropriate form of its display is a probabilistic model of random process. The authors have identified the most preferable approach to modeling of snow load. It consists in presenting a selective sequence of the year maximums in the form of a continuous random variable distributed according to the Gumbel law. Its parameters are expressed through the mathematical expectation and the standard sample set of meteorological observations. According to the calculated values of the parameters the authors have built a graphic interpretation of the law of distribution of this random variable. When building a model of the total snow load on the roof of a building the influence of various factors should be considered, such as: • snow shedding at a given roof slope; • snow movement caused by wind; • distribution of snow depending on the roof shape; • snow melting depending on the thermal characteristics of the roof; • the ability to drain meltwater from the surface of the roof. The resulting model of snow load is adapted for implementation using software complex “DINCIB-new” developed by the authors. The proposed approach to the modeling of the snow load on the roof of an industrial building allows correlating the repeatability period of its limit calculated value with the residual life of the research object. This has become possible due to the multiple implementation of an automated algorithm for calculating an industrial building, which was developed by the authors, with account of the varying values of snow load in relation to the corresponding mathematical expectation, with registering the quantities of

  6. Modelling of Dynamic Strain Aging with a Dislocation-Based Isotropic Hardening Model and Investigation of Orthogonal Loading

    NARCIS (Netherlands)

    Berisha, B.; Hora, P.; Tong, L.; Wahlen, A.; Boogaard, van den A.H.

    2008-01-01

    Based on experimental results, a dislocation material model describing the dynamic strain aging effect at different temperatures is presented. One and two stage loading tests were performed in order to investigate the influence of the loading direction as well as the temperature influence due to the

  7. Coopetitive Business Models in Future Mobile Broadband with Licensed Shared Access (LSA

    Directory of Open Access Journals (Sweden)

    P. Ahokangas

    2016-08-01

    Full Text Available Spectrum scarcity forces mobile network operators (MNOs providing mobile broadband services to develop new business models that address spectrum sharing. It engages MNOs into coopetitive relationship with incumbents. Licensed Shared Access (LSA concept complements traditional licensing and helps MNOs to access new spectrum bands on a shared basis. This paper discusses spectrum sharing with LSA from business perspective. It describes how coopetition and business model are linked conceptually, and identifies the influence of coopetition on future business models in LSA. We develop business models for dominant and challenger MNOs in traditional licensing and future with LSA. The results indicate that coopetition and business model concepts are linked via value co-creation and value co-capture. LSA offers different business opportunities to dominant and challenger MNOs. Offering, value proposition, customer segments and differentiation in business models become critical in mobile broadband.

  8. FAST Mast Structural Response to Axial Loading: Modeling and Verification

    Science.gov (United States)

    Knight, Norman F., Jr.; Elliott, Kenny B.; Templeton, Justin D.; Song, Kyongchan; Rayburn, Jeffery T.

    2012-01-01

    The International Space Station s solar array wing mast shadowing problem is the focus of this paper. A building-block approach to modeling and analysis is pursued for the primary structural components of the solar array wing mast structure. Starting with an ANSYS (Registered Trademark) finite element model, a verified MSC.Nastran (Trademark) model is established for a single longeron. This finite element model translation requires the conversion of several modeling and analysis features for the two structural analysis tools to produce comparable results for the single-longeron configuration. The model is then reconciled using test data. The resulting MSC.Nastran (Trademark) model is then extended to a single-bay configuration and verified using single-bay test data. Conversion of the MSC. Nastran (Trademark) single-bay model to Abaqus (Trademark) is also performed to simulate the elastic-plastic longeron buckling response of the single bay prior to folding.

  9. Stochastic empirical loading and dilution model for analysis of flows, concentrations, and loads of highway runoff constituents

    Science.gov (United States)

    Granato, Gregory E.; Jones, Susan C.

    2014-01-01

    In cooperation with FHWA, the U.S. Geological Survey developed the stochastic empirical loading and dilution model (SELDM) to supersede the 1990 FHWA runoff quality model. The SELDM tool is designed to transform disparate and complex scientific data into meaningful information about the adverse risks of runoff on receiving waters, the potential need for mitigation measures, and the potential effectiveness of such measures for reducing such risks. The SELDM tool is easy to use because much of the information and data needed to run it are embedded in the model and obtained by defining the site location and five simple basin properties. Information and data from thousands of sites across the country were compiled to facilitate the use of the SELDM tool. A case study illustrates how to use the SELDM tool for conducting the types of sensitivity analyses needed to properly assess water quality risks. For example, the use of deterministic values to model upstream stormflows instead of representative variations in prestorm flow and runoff may substantially overestimate the proportion of highway runoff in downstream flows. Also, the risks for total phosphorus excursions are substantially affected by the selected criteria and the modeling methods used. For example, if a single deterministic concentration is used rather than a stochastic population of values to model upstream concentrations, then the percentage of water quality excursions in the downstream receiving waters may depend entirely on the selected upstream concentration.

  10. Modification of the in vivo four-point loading model for studying mechanically induced bone adaptation.

    Science.gov (United States)

    Forwood, M R; Bennett, M B; Blowers, A R; Nadorfi, R L

    1998-09-01

    We modified the noninvasive, in vivo technique for strain application in the tibiae of rats (Turner et al., Bone 12:73-79, 1991). The original model applies four-point bending to right tibiae via an open-loop, stepper-motor-driven spring linkage. Depending on the magnitude of applied load, the model produces new bone formation at periosteal (Ps) or endocortical surfaces (Ec.S). Due to the spring linkage, however, the range of frequencies at which loads can be applied is limited. The modified system replaces this design with an electromagnetic vibrator. A load transducer in series with the loading points allows calibration, the loaders' position to be adjusted, and cyclic loading completed under load control as a closed servo-loop. Two experiments were conducted to validate the modified system: (1) a strain gauge was applied to the lateral surface of the right tibia of 5 adult female rats and strains measured at applied loads from 10 to 60 N; and (2) the bone formation response was determined in 28 adult female Sprague-Dawley rats. Loading was applied as a haversine wave with a frequency of 2 Hz for 18 sec, every second day for 10 days. Peak bending loads were applied at 33, 40, 52, and 64 N, and a sham-loading group was included at 64 N. Strains in the tibiae were linear between 10 and 60 N, and the average peak strain at the Ps.S at 60 N was 2664 +/- 250 microstrain, consistent with the results of Turner's group. Lamellar bone formation was stimulated at the Ec.S by applied bending, but not by sham loading. Bending strains above a loading threshold of 40 N increased Ec lamellar bone formation rate, bone forming surface, and mineral apposition rate with a dose response similar to that reported by Turner et al. (J Bone Miner Res 9:87-97, 1994). We conclude that the modified loading system offers precision for applied loads of between 0 and 70 N, versatility in the selection of loading rates up to 20 Hz, and a reproducible bone formation response in the rat tibia

  11. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix

    that of ‘mobilities design’. The book revolves around the following research question: How are design decisions and interventions staging mobilities? It builds upon the Staging Mobilities model (Jensen 2013) in an explorative inquiry into the problems and potentials of the design of mobilities. The exchange value...... between mobilities and design research is twofold. To mobilities research this means getting closer to the ‘material’, and to engage in the creative, explorative and experimental approaches of the design world which offer new potentials for innovative research. Design research, on the other hand, might...... enter into a fruitful relationship with mobilities research, offering a relational and mobile design thinking and a valuable base for a reflective design practice around the ubiquitous structures, spaces and systems of mobilities....

  12. Service Oriented Architectural Model for Load Flow Analysis in Power Systems

    Science.gov (United States)

    Muthu, Balasingh Moses; Veilumuthu, Ramachandran; Ponnusamy, Lakshmi

    2011-07-01

    The main objective of this paper is to develop the Service Oriented Architectural (SOA) Model for representation of power systems, especially of computing load flow analysis of large interconnected power systems. The proposed SOA model has three elements namely load flow service provider, power systems registry and client. The exchange of data using XML makes the power system services standardized and adaptable. The load flow service is provided by the service provider, which is published in power systems registry for enabling universal visibility and access to the service. The message oriented style of SOA using Simple Object Access Protocol (SOAP) makes the service provider and the power systems client to exist in a loosely coupled environment. This proposed model, portraits the load flow services as Web services in service oriented environment. To suit the power system industry needs, it easily integrates with the Web applications which enables faster power system operations.

  13. RBFNN Model for Predicting Nonlinear Response of Uniformly Loaded Paddle Cantilever

    Directory of Open Access Journals (Sweden)

    Abdullah H. Abdullah

    2009-01-01

    Full Text Available The Radial basis Function neural network (RBFNN model has been developed for the prediction of nonlinear response for paddle Cantilever with built-in edges and different sizes, thickness and uniform loads. Learning data was performed by using a nonlinear finite element program, incremental stages of the nonlinear finite element analysis were generated by using 25 schemes of built paddle Cantilevers with different thickness and uniform distributed loads. The neural network model has 5 input nodes representing the uniform distributed load and paddle size, length, width and thickness, eight nodes at hidden layer and one output node representing the max. deflection response (1500×1 represent the deflection response of load. Regression analysis between finite element results and values predicted by the neural network model shows the least error.

  14. Physics Based Model for Cryogenic Chilldown and Loading. Part I: Algorithm

    Science.gov (United States)

    Luchinsky, Dmitry G.; Smelyanskiy, Vadim N.; Brown, Barbara

    2014-01-01

    We report the progress in the development of the physics based model for cryogenic chilldown and loading. The chilldown and loading is model as fully separated non-equilibrium two-phase flow of cryogenic fluid thermally coupled to the pipe walls. The solution follow closely nearly-implicit and semi-implicit algorithms developed for autonomous control of thermal-hydraulic systems developed by Idaho National Laboratory. A special attention is paid to the treatment of instabilities. The model is applied to the analysis of chilldown in rapid loading system developed at NASA-Kennedy Space Center. The nontrivial characteristic feature of the analyzed chilldown regime is its active control by dump valves. The numerical predictions are in reasonable agreement with the experimental time traces. The obtained results pave the way to the development of autonomous loading operation on the ground and space.

  15. Mobile Outreach Crisis Services (MOCS): an innovative model for taking psychiatric care into the community.

    Science.gov (United States)

    McCarley, T D; Yates, W R

    1998-11-01

    Mobile outreach psychiatric services have become a popular model of providing care to the mentally ill. A mobile program has been instituted in Tulsa, Oklahoma, to provide care to homeless mentally ill in Tulsa County and to assist with emergency crisis intervention. The SPMI (Severely and Persistently Mentally III) have been a challenge for both medical and psychiatric providers, and MOCS (Mobile Outreach Crisis Services) was developed to address these problems. This article describes MOCS, briefly reviews recent literature, and discusses ways this program can benefit primary care physicians.

  16. Design and Implementation of Mobile Blended Learning Model Based on WeChat Public Platform

    Directory of Open Access Journals (Sweden)

    Han Yanyan

    2017-01-01

    Full Text Available Merging together the ideas of mobile learning, blended learning and flipped classroom, a Mobile Blended Learning Model (MBLM is constructed. Based on WeChat Public Platform (WPP, MBLM can optimize the instructional process and improve the learning efficiency. A Mobile Blended Learning System(MBLS is implemented by using MBLM, and it is constructed by both WPP and auxiliary learning system which based on Java Web. This system has reasonable designed function, easy operation, and beautiful interface, so it can effectively promote the popularization of MBLM.

  17. A cooling change-point model of community-aggregate electrical load

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Muhammad Tauha; Mokhtar, Marwan; Chiesa, Matteo; Armstrong, Peter [Mechanical Engineering Program, Masdar Institute of Science and Technology, PO Box 54224, Abu Dhabi (United Arab Emirates)

    2011-01-15

    Estimates of daily electrical cooling load for a city of 800,000 are developed based on the relationship between weather variables and daily-average electricity consumption over 1 year. The relationship is found to be nearly linear above a threshold temperature. Temperature and humidity were found to be the largest, at 59%, and second largest, at 21%, contributors to electrical cooling load. Direct normal irradiation intercepted by a vertical cylinder, DNI sin {theta}, was found to be a useful explanatory variable when modeling aggregates of buildings without a known or dominant orientation. The best study case model used DNI sin {theta} and diffuse horizontal irradiation (DHI) as distinct explanatory variables with annual electrical cooling load contributions of 9% and 11% respectively. Although the seasonal variation in electrical cooling load is large - on peak summer days more than 1.5 times the winter base load - the combined direct and diffuse solar contribution is essentially flat through the year, a condition at odds with the common assumption that solar cooling always provides a good match between supply and demand. The final model gives an electrical cooling load estimate for Abu Dhabi Island that corresponds to 40% of the total annual electrical load and 61% on the peak day. (author)

  18. Modelling and Dynamic Response of Steel Reticulated Shell under Blast Loading

    Directory of Open Access Journals (Sweden)

    Ximei Zhai

    2013-01-01

    Full Text Available Explicit finite element programme LS-DYNA was used to simulate a long-span steel reticulated shell under blast loading to investigate the structural dynamic responses in this paper. The elaborate finite element model of the Kiewitt-8 single-layer reticulated shell with span of 40 m subjected to central blast loading was established and all the process from the detonation of the explosive charge to the demolition, including the propagation of the blast wave and its interaction with structure was reproduced. The peak overpressure from the numerical analysis was compared with empirical formulas to verify the credibility and applicability of numerical simulation for blast loading. The dynamic responses of the structure under blast loading with different TNT equivalent weights of explosive and rise-span ratios were obtained. In addition, the response types of Kiewitt-8 single-layer reticulated shell subjected to central explosive blast loading were defined.

  19. Evaluation of physical load of hand-rim wheelchair propulsion on barrier-free model courses

    Directory of Open Access Journals (Sweden)

    Hiroshi Ikeda

    2010-07-01

    Full Text Available The aim of this study was to examine the effect of sidewalk developments on the physical load of hand-rim wheelchair propulsion using a barrier-free model course. Non-wheelchair users performed wheelchair exercise tests and R–R interval time, discomfort rating, and postural changes of seating were measured. As a result, due to excessively heavy load on certain parts of the body during active propulsion on the sidewalk, it was shown that barrier-free developments did not lead to a reduction of physical load. The results suggest the importance of a well-balanced barrier-free sidewalk design that takes into account the individual character of the wheelchair user's seating posture and physical load at the time of maneuvering. In addition, it is shown that the reduction of physical load can be considered as an effective method of evaluation.

  20. Ab initio charge-carrier mobility model for amorphous molecular semiconductors

    Science.gov (United States)

    Massé, Andrea; Friederich, Pascal; Symalla, Franz; Liu, Feilong; Nitsche, Robert; Coehoorn, Reinder; Wenzel, Wolfgang; Bobbert, Peter A.

    2016-05-01

    Accurate charge-carrier mobility models of amorphous organic molecular semiconductors are essential to describe the electrical properties of devices based on these materials. The disordered nature of these semiconductors leads to percolative charge transport with a large characteristic length scale, posing a challenge to the development of such models from ab initio simulations. Here, we develop an ab initio mobility model using a four-step procedure. First, the amorphous morphology together with its energy disorder and intermolecular charge-transfer integrals are obtained from ab initio simulations in a small box. Next, the ab initio information is used to set up a stochastic model for the morphology and transfer integrals. This stochastic model is then employed to generate a large simulation box with modeled morphology and transfer integrals, which can fully capture the percolative charge transport. Finally, the charge-carrier mobility in this simulation box is calculated by solving a master equation, yielding a mobility function depending on temperature, carrier concentration, and electric field. We demonstrate the procedure for hole transport in two important molecular semiconductors, α -NPD and TCTA. In contrast to a previous study, we conclude that spatial correlations in the energy disorder are unimportant for α -NPD. We apply our mobility model to two types of hole-only α -NPD devices and find that the experimental temperature-dependent current density-voltage characteristics of all devices can be well described by only slightly decreasing the simulated energy disorder strength.