WorldWideScience

Sample records for capacitated vehicle routing

  1. The pyramidal capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    2010-01-01

    This paper introduces the pyramidal capacitated vehicle routing problem (PCVRP) as a restricted version of the capacitated vehicle routing problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the pyramidal traveling salesman problem (PTSP). A pyramidal....... A main feature of the algorithm is that exact pricing over elementary routes are done in pseudo-polynomial time. Computational results suggest that PCVRP solutions are highly useful for obtaining near-optimal solutions to the CVRP. Furthermore, pricing of pyramidal routes may prove to be very useful...

  2. The Pyramidal Capacitated Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    This paper introduces the Pyramidal Capacitated Vehicle Routing Problem (PCVRP) as a restricted version of the Capacitated Vehicle Routing Problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the Pyramidal Traveling Salesman Problem (PTSP). A pyramidal...... of a pyramidal route is such that its traversal can be divided in two parts, where on the first part of the route, customers are visited in nondecreasing distance from the depot, and on the remaining part of the route, customers are visited in nonincreasing distance from the depot. Such a route shape is indeed...... found in many optimal solutions to CVRP instances. An optimal solution to the PCVRP may therefore be useful in itself as a heuristic solution to the CVRP. Further, an attempt can be made to find an even better CVRP solution by solving a TSP, possibly leading to a non-pyramidal route, for each...

  3. Fund allocation using capacitated vehicle routing problem

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita; Darus, Maslina

    2014-09-01

    In investment fund allocation, it is unwise for an investor to distribute his fund into several assets simultaneously due to economic reasons. One solution is to allocate the fund into a particular asset at a time in a sequence that will either maximize returns or minimize risks depending on the investor's objective. The vehicle routing problem (VRP) provides an avenue to this issue. VRP answers the question on how to efficiently use the available fleet of vehicles to meet a given service demand, subjected to a set of operational requirements. This paper proposes an idea of using capacitated vehicle routing problem (CVRP) to optimize investment fund allocation by employing data of selected stocks in the FTSE Bursa Malaysia. Results suggest that CRVP can be applied to solve the issue of investment fund allocation and increase the investor's profit.

  4. Locating Depots for Capacitated Vehicle Routing

    CERN Document Server

    Goertz, Inge Li

    2011-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input is a set of demand locations in a metric space and a fleet of k vehicles each of capacity Q. The objective is to locate k depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for this problem. To achieve this result, we reduce to the k-median-forest problem, which generalizes both k-median and minimum spanning tree, and which might be of independent interest. We give a (3+c)-approximation algorithm for k-median-forest, which leads to a (12+c)-approximation algorithm for the above location-routing problem, for any constant c>0. The algorithm for k-median-forest is just t-swap local search, and we prove that it has locality gap 3+2/t; this generalizes the corresponding result known for k-median. Finally we consider the "non-uniform" k-median-forest problem which has different cost ...

  5. Locating Depots for Capacitated Vehicle Routing

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath

    2011-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input to k-LocVRP is a set of demand locations in a metric space and a fleet of k vehicles each of capacity Q. The objective is to locate k depots, one for each vehicle, and compute routes for the vehicles so...... median forest, which leads to a (12+E)-approximation algorithm for k-LocVRP, for any constant E > 0. The algorithm for k median forest is t-swap local search, and we prove that it has locality gap 3 + 2 t ; this generalizes the corresponding result for k median [3]. Finally we consider the k median...... forest problem when there is a different (unrelated) cost function c for the MST part, i.e. the objective is Eu∈V d(u, S) + c(MST(V/S) ). We show that the locality gap for this problem is unbounded even under multi-swaps, which contrasts with the c = d case. Nevertheless, we obtain a constant...

  6. An Effective Hybrid Optimization Algorithm for Capacitated Vehicle Routing Problem

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Capacitated vehicle routing problem (CVRP) is an important combinatorial optimization problem. However, it is quite difficult to achieve an optimal solution with the traditional optimization methods owing to the high computational complexity. A hybrid algorithm was developed to solve the problem, in which an artificial immune clonal algorithm (AICA) makes use of the global search ability to search the optimal results and simulated annealing (SA) algorithm employs certain probability to avoid becoming trapped in a local optimum. The results obtained from the computational study show that the proposed algorithm is a feasible and effective method for capacitated vehicle routing problem.

  7. Capacitated Vehicle Routing with Non-Uniform Speeds

    CERN Document Server

    Gortz, Inge Li; Nagarajan, Viswanath; Ravi, R

    2010-01-01

    The capacitated vehicle routing problem (CVRP) involves distributing (identical) items from a depot to a set of demand locations, using a single capacitated vehicle. We study a generalization of this problem to the setting of multiple vehicles having non-uniform speeds (that we call Heterogenous CVRP), and present a constant-factor approximation algorithm. The technical heart of our result lies in achieving a constant approximation to the following TSP variant (called Heterogenous TSP). Given a metric denoting distances between vertices, a depot r containing k vehicles with possibly different speeds, the goal is to find a tour for each vehicle (starting and ending at r), so that every vertex is covered in some tour and the maximum completion time is minimized. This problem is precisely Heterogenous CVRP when vehicles are uncapacitated. The presence of non-uniform speeds introduces difficulties for employing standard tour-splitting techniques. In order to get a better understanding of this technique in our con...

  8. Ant Colony Optimization for Capacitated Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    H. V. Seow

    2012-01-01

    Full Text Available Problem statement: The Capacitated Vehicle Routing Problem (CVRP is a well-known combinatorial optimization problem which is concerned with the distribution of goods between the depot and customers. It is of economic importance to businesses as approximately 10-20% of the final cost of the goods is contributed by the transportation process. Approach: This problem was tackled using an Ant Colony Optimization (ACO combined with heuristic approaches that act as the route improvement strategies. The proposed ACO utilized a pheromone evaporation procedure of standard ant algorithm in order to introduce an evaporation rate that depends on the solutions found by the artificial ants. Results: Computational experiments were conducted on benchmark data set and the results obtained from the proposed algorithms shown that the application of combination of two different heuristics in the ACO had the capability to improve the ants’ solutions better than ACO embedded with only one heuristic. Conclusion: ACO with swap and 3-opt heuristic has the capability to tackle the CVRP with satisfactory solution quality and run time. It is a viable alternative for solving the CVRP.

  9. A branch-and-cut-and-price algorithm for the cumulative capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Wøhlk, Sanne; Lysgaard, Jens

    2014-01-01

    The paper considers the Cumulative Capacitated Vehicle Routing Problem (CCVRP), which is a variation of the well-known Capacitated Vehicle Routing Problem (CVRP). In this problem, the traditional objective of minimizing total distance or time traveled by the vehicles is replaced by minimizing the...... the sum of arrival times at the customers. A branch-and-cut-and-price algorithm for obtaining optimal solutions to the problem is proposed. Computational results based on a set of standard CVRP benchmarks are presented.......The paper considers the Cumulative Capacitated Vehicle Routing Problem (CCVRP), which is a variation of the well-known Capacitated Vehicle Routing Problem (CVRP). In this problem, the traditional objective of minimizing total distance or time traveled by the vehicles is replaced by minimizing...

  10. A branch-and-cut algorithm for the capacitated open vehicle routing problem

    DEFF Research Database (Denmark)

    Letchford, A.N.; Lysgaard, Jens; Eglese, R.W.

    2007-01-01

    In open vehicle routing problems, the vehicles are not required to return to the depot after completing service. In this paper, we present the first exact optimization algorithm for the open version of the well-known capacitated vehicle routing problem (CVRP). The algorithm is based on branch...... assess the quality of existing heuristic methods, and to compare the relative difficulty of open and closed versions of the same problem....

  11. A Branch-and-Cut Algorithm for the Capacitated Open Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Letchford, Adam N.; Lysgaard, Jens; Eglese, Richard W.

    In open vehicle routing problems, the vehicles are not required to return to the depot after completing service. In this paper, we present the first exact optimization algorithm for the open version of the well-known capacitated vehicle routing problem (CVRP). The algorithm is based on branch...... assess the quality of existing heuristic methods, and to compare the relative difficulty of open and closed versions of the same problem....

  12. Hybrid discrete particle swarm optimization algorithm for capacitated vehicle routing problem

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Capacitated vehicle routing problem (CVRP) is an NP-hard problem. For large-scale problems, it is quite difficult to achieve an optimal solution with traditional optimization methods due to the high computational complexity. A new hybrid approximation algorithm is developed in this work to solve the problem. In the hybrid algorithm, discrete particle swarm optimization (DPSO) combines global search and local search to search for the optimal results and simulated annealing (SA) uses certain probability to avoid being trapped in a local optimum. The computational study showed that the proposed algorithm is a feasible and effective approach for capacitated vehicle routing problem, especially for large scale problems.

  13. Optimization of Capacitated Vehicle Routing Problem by Nested Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Karuppusamy Kanthavel

    2011-01-01

    Full Text Available Problem statement: Vehicle routing problem determines the optimum route for each vehicle as a sequence of visiting cities. The problem has been defined as NP-hard and exact solution is relatively difficult to achieve for real time large scale models. Though several attempts to solve the problem were made in the literature, new approaches may be tried to solve the problem to further reduce computational efforts. Approach: In this context this study focuses on maximum utilization of loading capacity and determines the optimum set of vehicle routes for Capacitated Vehicle Routing Problem (CVRP by a Nested Particle Swarm Optimization (NPSO technique. The algorithm is implemented as Master PSO and slave PSO for the identification of candidate list and route sequence in nested form to optimize the model. Results: Benchmarking data set of capacitated vehicle routing is considered for the evaluations. The total distance of set vehicle route obtained by the new approach is compared with the best known solution and other existing techniques. Conclusions/Recommendations: The NPSO produces significant results and computational performance than the existing PSO algorithms. This newly proposed NPSO algorithm develops the vehicle schedule without any local optimization technique.

  14. A Food Chain Algorithm for Capacitated Vehicle Routing Problem with Recycling in Reverse Logistics

    Science.gov (United States)

    Song, Qiang; Gao, Xuexia; Santos, Emmanuel T.

    2015-12-01

    This paper introduces the capacitated vehicle routing problem with recycling in reverse logistics, and designs a food chain algorithm for it. Some illustrative examples are selected to conduct simulation and comparison. Numerical results show that the performance of the food chain algorithm is better than the genetic algorithm, particle swarm optimization as well as quantum evolutionary algorithm.

  15. Hybrid self organizing migrating algorithm - Scatter search for the task of capacitated vehicle routing problem

    Science.gov (United States)

    Davendra, Donald; Zelinka, Ivan; Senkerik, Roman; Jasek, Roman; Bialic-Davendra, Magdalena

    2012-11-01

    One of the new emerging application strategies for optimization is the hybridization of existing metaheuristics. The research combines the unique paradigms of solution space sampling of SOMA and memory retention capabilities of Scatter Search for the task of capacitated vehicle routing problem. The new hybrid heuristic is tested on the Taillard sets and obtains good results.

  16. An Artificial Bee Colony Algorithm for the Capacitated Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Szeto, W.Y.; Wu, Yongzhong; Ho, Sin C.

    This paper introduces an artificial bee colony heuristic for the capacitated vehicle routing problem. The artificial bee colony heuristic is a swarm-based heuristic, which mimics the foraging behavior of a honey bee swarm. The performance of the heuristic is evaluated on two sets of benchmark...

  17. A branch-and-price algorithm for the capacitated vehicle routing problem with stochastic demands

    DEFF Research Database (Denmark)

    Christiansen, Christian Holk; Lysgaard, Jens

    2007-01-01

    This article introduces a new exact algorithm for the Capacitated Vehicle Routing Problem with Stochastic Demands (CVRPSD). The CVRPSD can be formulated as a Set Partitioning Problem and it is shown that the associated column generation subproblem can be solved using a dynamic programming scheme...

  18. A new approach on auxiliary vehicle assignment in capacitated location routing problem

    Science.gov (United States)

    Bashiri, Mahdi; Rasoulinejad, Zeinab; Fallahzade, Ehsan

    2016-03-01

    The location routing problem (LRP) considers locating depots and vehicle routing decisions simultaneously. In classic LRP the number of customers in each route depends on the capacity of the vehicle. In this paper a capacitated LRP model with auxiliary vehicle assignment is presented in which the length of each route is not restricted by main vehicle capacity. Two kinds of vehicles are considered: main vehicles with higher capacity and fixed cost and auxiliary vehicles with lower capacity and fixed cost. The auxiliary vehicles can be added to the transportation system as an alternative strategy to cover the capacity limitations and they are just used to transfer goods from depots to vehicles and cannot serve the customers by themselves. To show the applicability of the proposed model, some numerical examples derived from the well-known instances are used. Moreover the model has been solved by some meta-heuristics for large sized instances. The results show the efficiency of the proposed model and the solution approach, considering the classic model and the exact solution approach, respectively.

  19. A new formulation for the 2-echelon capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Røpke, Stefan; Spoorendonk, Simon

    The 2-echelon capacitated vehicle routing problem (2E-CVRP) is a transportation and distribution problem where goods are transported from a depot to a set of customers possible via optional satellite facilities. The 2E-CVRP is relevant in city-logistic applications where legal restrictions make...... proposed for the previous formulations are redundant and that many model symmetries can now be avoided. A branch-and-cut algorithm is developed to solve this model to optimality....

  20. Capacitated Vehicle Routing with Non-Uniform Speeds

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Molinaro, Marco; Nagarajan, Viswanath;

    2011-01-01

    -uniform speeds introduces difficulties for employing standard tour-splitting techniques. In order to get a better understanding of this technique in our context, we appeal to ideas from the 2-approximation for minimum makespan scheduling in unrelated parallel machines of Lenstra et al. [19]. This motivates...... the introduction of a new approximate MST construction called Level-Prim, which is related to Light Approximate Shortest-path Trees [18]. The last component of our algorithm involves partitioning the Level-Prim tree and matching the resulting parts to vehicles. This decomposition is more subtle than usual since...

  1. A Simulation-Based Algorithm for the Capacitated Vehicle Routing Problem with Stochastic Travel Times

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    2013-01-01

    Full Text Available This paper presents a flexible solution methodology for the capacitated vehicle routing problem with stochastic travel times (CVRPSTT. One of the basic ideas of the methodology is to consider a vehicle working time lower than the actual maximum vehicle working time when designing CVRPSTT solutions. In this way, the working time surplus can be used to cope with unexpected congestions when necessary. Another important idea is to transform the CVRPSTT instance to a limited set of capacitated vehicle routing problems (CVRP, each of which is defined by a given percentage of the maximum vehicle working time. Thus, our approach can take advantage of any efficient heuristic that already exists for the CVRP. Based on the two key ideas, this paper presents a simulation-based algorithm, in which Monte Carlo simulation is used to obtain estimates of the cost and the reliability of each solution, and the Clarke and Wright heuristic is improved to generate more reliable solutions. Finally, a number of numerical experiments are done in the paper with the purpose of analyzing the efficiency of the described methodology under different uncertainty scenarios.

  2. A branch-and-cut algorithm for the symmetric two-echelon capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Spoorendonk, Simon; Røpke, Stefan

    2013-01-01

    This paper presents an exact method for solving the symmetric two-echelon capacitated vehicle routing problem, a transportation problem concerned with the distribution of goods from a depot to a set of customers through a set of satellite locations. The presented method is based on an edge flow...... model that is a relaxation and provides a valid lower bound. A specialized branching scheme is employed to obtain feasible solutions. Out of a test set of 93 instances the algorithm is able to solve 47 to optimality surpassing previous exact algorithms....

  3. An artificial bee colony algorithm for the capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Szeto, W.Y.; Wu, Yongzhong; Ho, Sin C.

    2011-01-01

    This paper introduces an artificial bee colony heuristic for solving the capacitated vehicle routing problem. The artificial bee colony heuristic is a swarm-based heuristic, which mimics the foraging behavior of a honey bee swarm. An enhanced version of the artificial bee colony heuristic is also...... proposed to improve the solution quality of the original version. The performance of the enhanced heuristic is evaluated on two sets of standard benchmark instances, and compared with the original artificial bee colony heuristic. The computational results show that the enhanced heuristic outperforms...

  4. A Column Generation Approach to the Capacitated Vehicle Routing Problem with Stochastic Demands

    DEFF Research Database (Denmark)

    Christiansen, Christian Holk; Lysgaard, Jens

    In this article we introduce a new exact solution approach to the Capacitated Vehicle Routing Problem with Stochastic Demands (CVRPSD). In particular, we consider the case where all customer demands are distributed independently and where each customer's demand follows a Poisson distribution....... The CVRPSD can be formulated as a Set Partitioning Problem. We show that, under the above assumptions on demands, the associated column generation subproblem can be solved using a dynamic programming scheme which is similar to that used in the case of deterministic demands. To evaluate the potential of our...

  5. Capacitated vehicle routing problem for PSS uses based on ubiquitous computing: An emerging markets approach

    Directory of Open Access Journals (Sweden)

    Alberto Ochoa-Ortíz

    2015-01-01

    Full Text Available El problema de ruteo de vehículos bajo las limitaciones de capacidad y basado en computación ubicua desde una perspectiva relacionada con PSS (Producto-Servicio de Sistemas para desarrollar configuraciones para el transporte urbano de mercancías es abordado. Éste trabajo considera las especificidades de la logística urbana bajo un contexto de mercados emergentes. En este caso, involucra: i bajas competencias logísticas de los tomadores de decisiones; ii la limitada disponibilidad de datos; y iii restringido acceso a tecnología de alto desempeño para calcular rutas de transporte óptimas. Por lo tanto, se propone el uso de un software libre que proporciona soluciones de bajo costo (en tiempo y recursos. El artículo muestra la aplicación de los resultados de una herramienta de software basado en la Teoría de Grafos utilizado para analizar y resolver un CVRP (Capacitated Vehicle Routing Problem. Se utilizó el caso de una empresa local de distribución de alimentos situada en una gran ciudad de México. Sobre la base de una flora de vehículos pequeños, todos con las mismas especificaciones técnicas y una capacidad de carga comparable.

  6. An optimization algorithm for a capacitated vehicle routing problem with time windows

    Indian Academy of Sciences (India)

    PINAR KIRCI

    2016-05-01

    In this paper, vehicle routing problem (VRP) with time windows and real world constraints are considered as a real-world application on google maps. Also, tabu search is used and Hopfield neural networks is utilized. Basic constraints consist of customer demands, time windows, vehicle speed, vehicle capacity andworking hours. Recently, cost and on-time delivery are the most important actors in logistics. Thus, the logistic applications attract attention of companies. In logistic management, determining the locations of delivery points and deciding the path are the vital components that should be considered. Deciding the paths of vehicles provides companies to use their vehicles efficiently. And with utilizing optimized paths, big amounts of cost and time savings will be gained. The main aim of the work is providing the best path according to the needs of the customers, minimizing the costs with utilizing the VRP and presenting an application for companies that need logistic management. To compare the results, simulated annealing is used on special scenarios. And t-test is performed in the study for the visited path in km with p-value of 0.05.

  7. An Approximation Algorithm for the Capacitated Arc Routing Problem

    DEFF Research Database (Denmark)

    Wøhlk, Sanne

    2008-01-01

    In this paper we consider approximation of the Capacitated Arc Routing Problem, which is the problem of servicing a set of edges in a graph using a fleet of capacity constrained vehicles. We present a 7/2 - 3/W-approximation algorithm for the problem and prove that this algorithm outperforms...

  8. Capacitated arc routing problem and its extensions in waste collection

    Energy Technology Data Exchange (ETDEWEB)

    Fadzli, Mohammad; Najwa, Nurul [Institut Matematik Kejuruteraan, Universiti Malaysia Perlis, Kampus Pauh Putra, 02600 Arau, Perlis (Malaysia); Luis, Martino [Othman Yeop Abdullah Graduate School of Business, Universiti Utara Malaysia, 06010 Sintok, Kedah (Malaysia)

    2015-05-15

    Capacitated arc routing problem (CARP) is the youngest generation of graph theory that focuses on solving the edge/arc routing for optimality. Since many years, operational research devoted to CARP counterpart, known as vehicle routing problem (VRP), which does not fit to several real cases such like waste collection problem and road maintenance. In this paper, we highlighted several extensions of capacitated arc routing problem (CARP) that represents the real-life problem of vehicle operation in waste collection. By purpose, CARP is designed to find a set of routes for vehicles that satisfies all pre-setting constraints in such that all vehicles must start and end at a depot, service a set of demands on edges (or arcs) exactly once without exceeding the capacity, thus the total fleet cost is minimized. We also addressed the differentiation between CARP and VRP in waste collection. Several issues have been discussed including stochastic demands and time window problems in order to show the complexity and importance of CARP in the related industry. A mathematical model of CARP and its new version is presented by considering several factors such like delivery cost, lateness penalty and delivery time.

  9. Capacitated arc routing problem and its extensions in waste collection

    Science.gov (United States)

    Fadzli, Mohammad; Najwa, Nurul; Luis, Martino

    2015-05-01

    Capacitated arc routing problem (CARP) is the youngest generation of graph theory that focuses on solving the edge/arc routing for optimality. Since many years, operational research devoted to CARP counterpart, known as vehicle routing problem (VRP), which does not fit to several real cases such like waste collection problem and road maintenance. In this paper, we highlighted several extensions of capacitated arc routing problem (CARP) that represents the real-life problem of vehicle operation in waste collection. By purpose, CARP is designed to find a set of routes for vehicles that satisfies all pre-setting constraints in such that all vehicles must start and end at a depot, service a set of demands on edges (or arcs) exactly once without exceeding the capacity, thus the total fleet cost is minimized. We also addressed the differentiation between CARP and VRP in waste collection. Several issues have been discussed including stochastic demands and time window problems in order to show the complexity and importance of CARP in the related industry. A mathematical model of CARP and its new version is presented by considering several factors such like delivery cost, lateness penalty and delivery time.

  10. An evolutionary algorithm for the capacitated arc routing problem.

    Directory of Open Access Journals (Sweden)

    Dalessandro Soares Vianna

    2006-08-01

    Full Text Available The Capacitated Arc Routing Problem (CARP consists of visiting a subset of edges of the graph that describes the problem. CARP applications include urban waste collection and inspection of power lines. The CARP is NP-hard, even in the single-vehicle case (called Rural Postman Problem. In this case, the use of metaheuristics is an efficient solution strategy. This paper proposes a hybrid genetic algorithm for the CARP, which is tested on available instances of the literature. The results obtained until now show the effectiveness of the proposed algorithm when it is compared with lower bounds described in the literature.

  11. General heuristics algorithms for solving capacitated arc routing problem

    Science.gov (United States)

    Fadzli, Mohammad; Najwa, Nurul; Masran, Hafiz

    2015-05-01

    In this paper, we try to determine the near-optimum solution for the capacitated arc routing problem (CARP). In general, NP-hard CARP is a special graph theory specifically arises from street services such as residential waste collection and road maintenance. By purpose, the design of the CARP model and its solution techniques is to find optimum (or near-optimum) routing cost for a fleet of vehicles involved in operation. In other words, finding minimum-cost routing is compulsory in order to reduce overall operation cost that related with vehicles. In this article, we provide a combination of various heuristics algorithm to solve a real case of CARP in waste collection and benchmark instances. These heuristics work as a central engine in finding initial solutions or near-optimum in search space without violating the pre-setting constraints. The results clearly show that these heuristics algorithms could provide good initial solutions in both real-life and benchmark instances.

  12. Capacitated Vehicle Routing Problem Based on Improved Immune Genetic Algorithm%基于改进免疫算法的有能力约束车辆路径问题

    Institute of Scientific and Technical Information of China (English)

    梁勤欧

    2011-01-01

    针对遗传算法、免疫遗传算法在解决车辆路径问题(VRP)中存在的问题与不足,提出了一种改进免疫遗传算法.该算法主要在检查个体的多样性程度方面进行了简化,运用多样性指数阈值控制种群个体的多样性.通过有能力约束VRP的实验验证了新算法,得到了满意的效果.%There are some problems when genetic algorithm and immune genetic algorithm are used to solve Vehicle Routing Problem ( VRP). An improved immune genetic algorithm was proposed to overcome these disadvantages. The characteristic of the improved immune genetic algorithm is that the diversity detection method was simplified and population diversity was controlled by threshold determination method. Then a simple example of capacitated vehicle routing problem was conducted, and an improved immune genetic algorithm and perfect results were obtained.

  13. Stochastic Vehicle Routing with Recourse

    CERN Document Server

    Goertz, Inge Li; Saket, Rishi

    2012-01-01

    We study the classic Vehicle Routing Problem in the setting of stochastic optimization with recourse. StochVRP is a two-stage optimization problem, where demand is satisfied using two routes: fixed and recourse. The fixed route is computed using only a demand distribution. Then after observing the demand instantiations, a recourse route is computed -- but costs here become more expensive by a factor lambda. We present an O(log^2 n log(n lambda))-approximation algorithm for this stochastic routing problem, under arbitrary distributions. The main idea in this result is relating StochVRP to a special case of submodular orienteering, called knapsack rank-function orienteering. We also give a better approximation ratio for knapsack rank-function orienteering than what follows from prior work. Finally, we provide a Unique Games Conjecture based omega(1) hardness of approximation for StochVRP, even on star-like metrics on which our algorithm achieves a logarithmic approximation.

  14. THE PERIODIC CAPACITATED ARC ROUTING PROBLEM LINEAR PROGRAMMING MODEL,METAHEURISTIC AND LOWER BOUNDS

    Institute of Scientific and Technical Information of China (English)

    Feng CHU; Nacima LABADI; Christian PRINS

    2004-01-01

    The Periodic Capacitated Arc Routing Problem (PCARP) generalizes the well known NP-hard Capacitated Arc Routing Problem (CARP) by extending the single period to multi-period horizon.The Capacitated Arc Routing Problem (CARP) is defined on an undirected network in which a fleet of identical vehicles is based at a depot node. A subset of edges, called tasks, must be serviced by a vehicle. The CARP consists of determining a set of feasible vehicle trips that minimizes the total cost of traversed edges. The PCARP involves the assignment of tasks to periods and the determination of vehicles trips in each period, to minimize the total cost on the whole horizon. This new problem arises in various real life applications such as waste collection, mail delivery, etc. In this paper, a new linear programming model and preliminary lower bounds based on graph transformation are proposed. A meta-heuristic approach - Scatter Search (SS) is developed for the PCARP and evaluated on a large variety of instances.

  15. Multi-objective model and methods for capacitated vehicle routing problem facing different target preference%面向不同目标偏好的 CVRP多目标模型及其求解方法

    Institute of Scientific and Technical Information of China (English)

    王超; 金淳; 韩庆平

    2016-01-01

    This paper proposed a multi-objective model for capacitated vehicle routing problem (CVRP)facing different target preference (MOCVRPFDTP)to solve CVRP more effectively and evaluate transportation cost comprehensively.There were three different preference structures in this model,which were joint optimization of loading and CVRP,absolute minimum vehi-cles preference,and path optimization preference.To solve this model,this paper constructed an algorithm framework with cor-responding algorithms.In experiments,the model and its solving methods display satisfactory performance in the testing for VR-PLIB,and they are more suitable for practical instance.%为了更有效地求解车辆路径问题、全方位地评估物流运输成本,提出了面向不同目标偏好的车载能力约束车辆路径问题的多目标优化模型(MOCVRPFDTP),其包括三种不同的偏好结构:装载与 CVRP 联合优化、绝对最小车辆数偏好及路径优化偏好。为了求解该模型,设计了算法架构及具体算法。在实验中,该模型及其求解方法对 CVRP 国际标准算例 VRPLIB 的测试结果显示了令人满意的性能,并且它更适用于实际 CVRP 问题的求解。

  16. Classification of Dynamic Vehicle Routing Systems

    DEFF Research Database (Denmark)

    Larsen, Allan; Madsen, Oli B.G.; Solomon, Marius M.

    2007-01-01

    to classify dynamic vehicle routing systems. Methods for evaluation of the performance of algorithms that solve on-line routing problems are discussed and we list some of the most important issues to include in the system objective. Finally, we provide a three-echelon classification of dynamic vehicle routing......This chapter discusses important characteristics seen within dynamic vehicle routing problems. We discuss the differences between the traditional static vehicle routing problems and its dynamic counterparts. We give an in-depth introduction to the degree of dynamism measure which can be used...

  17. A mathematical modeling proposal for a Multiple Tasks Periodic Capacitated Arc Routing Problem

    Directory of Open Access Journals (Sweden)

    Cleverson Gonçalves dos Santos

    2015-12-01

    Full Text Available The countless accidents and incidents occurred at dams at the last years, propelled the development of politics related with dams safety. One of the strategies is related to the plan for instrumentation and monitoring of dams. The monitoring demands from the technical team the reading of the auscultation data, in order to periodically monitor the dam. The monitoring plan of the dam can be modeled as a problem of mathematical program of the periodical capacitated arcs routing program (PCARP. The PCARP is considered as a generalization of the classic problem of routing in capacitated arcs (CARP due to two characteristics: 1 Planning period larger than a time unity, as that vehicle make several travels and; 2 frequency of associated visits to the arcs to be serviced over the planning horizon. For the dam's monitoring problem studied in this work, the frequent visits, along the time horizon, it is not associated to the arc, but to the instrument with which is intended to collect the data. Shows a new problem of Multiple tasks Periodic Capacitated Arc Routing Problem and its elaboration as an exact mathematical model. The new main characteristics presented are: multiple tasks to be performed on each edge or edges; different frequencies to accomplish each of the tasks; heterogeneous fleet; and flexibility for more than one vehicle passing through the same edge at the same day. The mathematical model was implemented and examples were generated randomly for the proposed model's validation.

  18. Vehicle routing problem in investment fund allocation

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita; Mohd, Ismail

    2013-04-01

    Since its introduction by Dantzig and Ramser in 1959, vehicle routing problem keeps evolving in theories, applications and variability. The evolution in computing and technology are also important contributors to research in solving vehicle routing problem. The main sectors of interests among researchers and practitioners for vehicle routing problem are transportation, distribution and logistics. However, literature found that concept and benefits of vehicle routing problem are not taken advantages of by researchers in the field of investment. Other methods found used in investment include multi-objective programming, linear programming, goal programming and integer programming. Yet the application of vehicle routing problem is not fully explored. A proposal on a framework of the fund allocation optimization using vehicle routing problem is presented here. Preliminary results using FTSE Bursa Malaysia data testing the framework are also given.

  19. Vehicle Routing With User Generated Trajectory Data

    DEFF Research Database (Denmark)

    Ceikute, Vaida; Jensen, Christian S.

    Rapidly increasing volumes of GPS data collected from vehicles provide new and increasingly comprehensive insight into the routes that drivers prefer. While routing services generally compute shortest or fastest routes, recent studies suggest that local drivers often prefer routes that are neither...... shortest nor fastest, indicating that drivers value route properties that are diverse and hard to quantify or even identify. We propose a routing service that uses an existing routing service while exploiting the availability of historical route usage data from local drivers. Given a source and destination......, the service recommends a corresponding route that is most preferred by local drivers. It uses a route preference function that takes into account the number of distinct drivers and the number of trips associated with a route, as well as temporal aspects of the trips. The paper provides empirical studies...

  20. A variable neighborhood descent based heuristic to solve the capacitated location-routing problem

    Directory of Open Access Journals (Sweden)

    M. S. Jabal-Ameli

    2011-01-01

    Full Text Available Location-routing problem (LRP is established as a new research area in the context of location analysis. The primary concern of LRP is on locating facilities and routing of vehicles among established facilities and existing demand points. In this work, we address the capacitated LRP which arises in many practical applications within logistics and supply chain management. The objective is to minimize the overall system costs which include the fixed costs of opening depots and using vehicles at each depot site, and the variable costs associated with delivery activities. A novel heuristic is proposed which is based on variable neighborhood descent (VND algorithm to solve the resulted problem. The computational study indicates that the proposed VND based heuristic is highly competitive with the existing solution algorithms in terms of solution quality.

  1. Disruption management of the vehicle routing problem with vehicle breakdown

    DEFF Research Database (Denmark)

    Mu, Q; Fu, Z; Lysgaard, Jens;

    2011-01-01

    This paper introduces a new class of problem, the disrupted vehicle routing problem (VRP), which deals with the disruptions that occur at the execution stage of a VRP plan. The paper then focuses on one type of such problem, in which a vehicle breaks down during the delivery and a new routing...

  2. Optimum Route Selection for Vehicle Navigation

    Directory of Open Access Journals (Sweden)

    Dalip

    2016-02-01

    Full Text Available The objective of Optimum Route Selection for Vehicle Navigation System (ORSVNS article is to develop a system, which provides information about real time alternate routes to the drivers and also helps in selecting the optimal route among all the alternate routes from an origin to destination. Two types of query systems, special and general, are designed for drivers. Here, the criterion for route selection is introduced using primary and secondary road attributes. The presented methodology helps the drivers in better decision making to choose optimal route using fuzzy logic. For experimental results ORSVNS is tested over 220 km portion of Haryana state in India.

  3. A Capacitated Location Routing Problem with Semi Soft Time Windows

    Directory of Open Access Journals (Sweden)

    Maryam Gharavani

    2015-03-01

    Full Text Available In this article we address The Location Routing Problem (LRP, where there is a set of customers with known demand and a set of potential depot site and there is a set of heterogeneous vehicle with a certain capacity. Due to the similarity of the problem with real world, the constraints of depot capacity and vehicle capacity as well as route length have been considered simultaneously. The model provided in this article is described concerning the semi soft time window in which that a delay in service delivery time results in delay costs. The total costs in the proposed model include, the total fixed costs of construction depot, fixed costs associated with the use of vehicles, the total distance traveled by the vehicles, the total time within the system for the vehicle and penalty cost associated with the violation of working hour of vehicles and penalty costs associated with delay time in the start of service to customers and the aim is to minimize the total cost. Due to its complexity, two Meta-Heuristic algorithms of Genetic and Tabu Search algorithm have been used. Since the performance of the Meta-Heuristic algorithms is significantly influenced by their parameters, Taguchi Method is used to set the parameters of developed algorithms. Finally, the result represents that the Genetic Algorithm and Tabu Search are significantly efficient in terms of better quality of solution and computational time respectively.

  4. Stochastic vehicle routing: from theory to practice

    OpenAIRE

    Weyland, Dennis; Gambardella, Luca Maria; Montemanni, Roberto

    2013-01-01

    In this thesis we discuss practical and theoretical aspects of various stochastic vehicle routing problems. These are combinatorial optimization problems related to the field of transportation and logistics in which input data is (partially) represented in a stochastic way. More in detail, we focus on two-stage stochastic vehicle routing problems and in particular on so-called a priori optimization problems. The results are divided into a theoretical part and a practical part. In fact, the ...

  5. Optimizing departure times in vehicle routes

    NARCIS (Netherlands)

    Kok, A.L.; Hans, E.W.; Schutten, J.M.J.

    2008-01-01

    Most solution methods for the vehicle routing problem with time windows (VRPTW) develop routes from the earliest feasible departure time. However, in practice, temporal traffic congestions make that such solutions are not optimal with respect to minimizing the total duty time. Furthermore, VRPTW sol

  6. Implementation Weather-Type Models of Capacitated Arc Routing Problem via Heuristics

    Directory of Open Access Journals (Sweden)

    Zuhaimy Ismail

    2011-01-01

    Full Text Available Problem statement: In this study, we introduced a new and real-life condition of Capacitated Arc Routing Problem (CARP, a model that represents vehicles operation in waste collection. In general, we studied the element of rain drops that affected the collected waste weight in total by imposed a new variable namely rainy weight age. In rainy days, the household refusals did not increase in volumes, but in weights due to rain drops. Consequently, this matter thus burdened vehicles capacity and prolonged its operation time. This dynamic variable thus changes the initial CARP model where the existing model did not consider other external elements that have effected onto the model. Approach: Then we developed and enhanced CARP by integrating stochastic demand and time windows to suit the models with our specific case. Results: Objectively, CARP with stochastic demand (CARPSD and CARP with time windows (CARPTW were designed to minimize the total routing cost and number of trips for a vehicle. Our approach is to design CARP models in almost likely to road layout in residential area and graphically this model is called mesh network. We also developed a constructive heuristic that is called nearest procedure based on highest demand/cost (NPHDC and work in conjunction with switching rules to search the feasible solution. Conclusion: Our preliminary results show a higher cost and more trips are needed when the vehicle operates in rainy day compared to normal day operation.

  7. Rich Vehicle Routing Problems and Applications

    DEFF Research Database (Denmark)

    Wen, Min

    of these problems was motivated by our cooperation with industrial companies, particularly Transvision A/S and its client distributors, and Danish Crown. The models and methods proposed in the thesis are general and can be applied to practical routing problems arising in many other distribution companies as well...... the company’s solution in terms of all the objectives, including the travel time, customer waiting and daily workload balances, under the given constraints considered in the work. Finally, we address an integrated vehicle routing and driver scheduling problem, in which a large number of practical constraints......The Vehicle Routing Problem (VRP) is one of the most important and challenging optimization problems in the field of Operations Research. It was introduced by Dantzig and Ramser (1959) and defined as the problem of designing the optimal set of routes for a fleet of vehicles in order to serve...

  8. Stochastic vehicle routing with recourse

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath; Saket, Rishi

    2012-01-01

    instantiations, a recourse route is computed - but costs here become more expensive by a factor λ. We present an O(log2n ·log(nλ))-approximation algorithm for this stochastic routing problem, under arbitrary distributions. The main idea in this result is relating StochVRP to a special case of submodular...... orienteering, called knapsack rank-function orienteering. We also give a better approximation ratio for knapsack rank-function orienteering than what follows from prior work. Finally, we provide a Unique Games Conjecture based ω(1) hardness of approximation for StochVRP, even on star-like metrics on which our...

  9. Genetic algorithms for the vehicle routing problem

    Science.gov (United States)

    Volna, Eva

    2016-06-01

    The Vehicle Routing Problem (VRP) is one of the most challenging combinatorial optimization tasks. This problem consists in designing the optimal set of routes for fleet of vehicles in order to serve a given set of customers. Evolutionary algorithms are general iterative algorithms for combinatorial optimization. These algorithms have been found to be very effective and robust in solving numerous problems from a wide range of application domains. This problem is known to be NP-hard; hence many heuristic procedures for its solution have been suggested. For such problems it is often desirable to obtain approximate solutions, so they can be found fast enough and are sufficiently accurate for the purpose. In this paper we have performed an experimental study that indicates the suitable use of genetic algorithms for the vehicle routing problem.

  10. Shortest Paths and Vehicle Routing

    DEFF Research Database (Denmark)

    Petersen, Bjørn

    This thesis presents how to parallelize a shortest path labeling algorithm. It is shown how to handle Chvátal-Gomory rank-1 cuts in a column generation context. A Branch-and-Cut algorithm is given for the Elementary Shortest Paths Problem with Capacity Constraint. A reformulation of the Vehicle...

  11. Vehicle Coordinated Strategy for Vehicle Routing Problem with Fuzzy Demands

    Directory of Open Access Journals (Sweden)

    Chang-shi Liu

    2016-01-01

    Full Text Available The vehicle routing problem with fuzzy demands (VRPFD is considered. A fuzzy reasoning constrained program model is formulated for VRPFD, and a hybrid ant colony algorithm is proposed to minimize total travel distance. Specifically, the two-vehicle-paired loop coordinated strategy is presented to reduce the additional distance, unloading times, and waste capacity caused by the service failure due to the uncertain demands. Finally, numerical examples are presented to demonstrate the effectiveness of the proposed approaches.

  12. Routing Autonomous Vehicles in Congested Transportation Networks: Structural Properties and Coordination Algorithms

    OpenAIRE

    Zhang, Rick; Rossi, Federico; Pavone, Marco

    2016-01-01

    This paper considers the problem of routing and rebalancing a shared fleet of autonomous (i.e., self-driving) vehicles providing on-demand mobility within a capacitated transportation network, where congestion might disrupt throughput. We model the problem within a network flow framework and show that under relatively mild assumptions the rebalancing vehicles, if properly coordinated, do not lead to an increase in congestion (in stark contrast to common belief). From an algorithmic standpoint...

  13. Vehicle routing problem for save fuel consumption

    Institute of Scientific and Technical Information of China (English)

    LIU Hao; AI Wen-wen

    2016-01-01

    This study has extended a vehicle routing problem,by considering economy of fuel,and constructing a LF-VRP model,to obtain optimal fixed costs.Our objective was to minimize not only distance,but also the fuel consumption.A example were developed to solve the proposed models.It was found that our proposed models yielded better results than the traditional VRP models.

  14. Application of Harmony Search to Vehicle Routing

    Directory of Open Access Journals (Sweden)

    Zong W.  Geem

    2005-01-01

    Full Text Available A phenomenon-inspired meta-heuristic algorithm, harmony search, imitating music improvisation process, is introduced and applied to vehicle routing problem, then compared with one of the popular evolutionary algorithms, genetic algorithm. The harmony search algorithm conceptualized a group of musicians together trying to search for better state of harmony. This algorithm was applied to a test traffic network composed of one bus depot, one school and ten bus stops with demand by commuting students. This school bus routing example is a multi-objective problem to minimize both the number of operating buses and the total travel time of all buses while satisfying bus capacity and time window constraints. Harmony search could find good solution within the reasonable amount of time and computation.

  15. Flexible Bond Wire Capacitive Strain Sensor for Vehicle Tyres.

    Science.gov (United States)

    Cao, Siyang; Pyatt, Simon; Anthony, Carl J; Kubba, Ammar I; Kubba, Ali E; Olatunbosun, Oluremi

    2016-01-01

    The safety of the driving experience and manoeuvrability of a vehicle can be improved by detecting the strain in tyres. To measure strain accurately in rubber, the strain sensor needs to be flexible so that it does not deform the medium that it is measuring. In this work, a novel flexible bond wire capacitive strain sensor for measuring the strain in tyres is developed, fabricated and calibrated. An array of 25 micron diameter wire bonds in an approximately 8 mm × 8 mm area is built to create an interdigitated structure, which consists of 50 wire loops resulting in 49 capacitor pairs in parallel. Laser machining was used to pattern copper on a flexible printed circuit board PCB to make the bond pads for the wire attachment. The wire array was finally packaged and embedded in polydimethylsiloxane (PDMS), which acts as the structural material that is strained. The capacitance of the device is in a linear like relationship with respect to the strain, which can measure the strain up to at least ±60,000 micro-strain (±6%) with a resolution of ~132 micro-strain (0.013%). In-tyre testing under static loading has shown the ability of the sensor to measure large tyre strains. The technology used for sensor fabrication lends itself to mass production and so the design is considered to be consistent with low cost commercialisable strain sensing technology. PMID:27338402

  16. Flexible Bond Wire Capacitive Strain Sensor for Vehicle Tyres

    Science.gov (United States)

    Cao, Siyang; Pyatt, Simon; Anthony, Carl J.; Kubba, Ammar I.; Kubba, Ali E.; Olatunbosun, Oluremi

    2016-01-01

    The safety of the driving experience and manoeuvrability of a vehicle can be improved by detecting the strain in tyres. To measure strain accurately in rubber, the strain sensor needs to be flexible so that it does not deform the medium that it is measuring. In this work, a novel flexible bond wire capacitive strain sensor for measuring the strain in tyres is developed, fabricated and calibrated. An array of 25 micron diameter wire bonds in an approximately 8 mm × 8 mm area is built to create an interdigitated structure, which consists of 50 wire loops resulting in 49 capacitor pairs in parallel. Laser machining was used to pattern copper on a flexible printed circuit board PCB to make the bond pads for the wire attachment. The wire array was finally packaged and embedded in polydimethylsiloxane (PDMS), which acts as the structural material that is strained. The capacitance of the device is in a linear like relationship with respect to the strain, which can measure the strain up to at least ±60,000 micro-strain (±6%) with a resolution of ~132 micro-strain (0.013%). In-tyre testing under static loading has shown the ability of the sensor to measure large tyre strains. The technology used for sensor fabrication lends itself to mass production and so the design is considered to be consistent with low cost commercialisable strain sensing technology. PMID:27338402

  17. A Branch-and-Price Algorithm for the Capacitated Arc Routing Problem with Stochastic Demands

    DEFF Research Database (Denmark)

    Christiansen, Christian Holk; Lysgaard, Jens; Wøhlk, Sanne

    2009-01-01

    We address the Capacitated Arc Routing Problem with Stochastic Demands (CARPSD), which we formulate as a Set Partitioning Problem. The CARPSD is solved by a Branch-and-Price algorithm, which we apply without graph transformation. The demand's stochastic nature is incorporated into the pricing...

  18. The vehicle routing problem with backhauls

    Energy Technology Data Exchange (ETDEWEB)

    Goetschalckx, M.; Jacobs-Blecha, C.

    1989-09-05

    The Vehicle Routing Problem with Backhauls is a pickup/delivery problem where on each route all deliveries must be made before any pickups. A two-phased solution methodology is proposed. In the first phase, a high quality initial feasible solution is generated based on spacefilling curves. In the second phase, this solution is improved based on optimization of the subproblems identified in a mathematical model of the problem. An extensive computational analysis of several initial solution algorithms is presented, which identifies the tradeoffs between solution quality and computational requirements. The class of greedy algorithms is capacity oriented, while K-median algorithms focus on distance. It is concluded that the greedy and K-median algorithms generate equivalent tour lengths, but that the greedy procedure reduces the required number of trucks and increases the truck utilization. The effect of exchange improvement procedures as well as optimal procedures on solution quality and run time is demonstrated. Comparisons with the Clark-Wright method adapted to backhauls are also given. 4 figs., 26 refs.

  19. A new efficient transformation of the generalized vehicle routing problem into the classical vehicle routing problem

    Directory of Open Access Journals (Sweden)

    Pop Petrica

    2011-01-01

    Full Text Available Classical combinatorial optimization problems can be generalized in a natural way by considering a related problem relative to a given partition of the nodes of the graph into node sets. In the literature one can find generalized problems such as: generalized minimum spanning tree, generalized traveling salesman problem, generalized Steiner tree problem, generalized vehicle routing problem, etc. These generalized problems typically belong to the class of NP-complete problems; they are harder than the classical ones, and nowadays are intensively studied due to their interesting properties and applications in the real world. Because of the complexity of finding the optimal or near-optimal solution in case of the generalized combinatorial optimization problems, great effort has been made, by many researchers, to develop efficient ways of their transformation into classical corresponding variants. We present in this paper an efficient way of transforming the generalized vehicle routing problem into the vehicle routing problem, and a new integer programming formulation of the problem.

  20. Distributed Decision Making in Combined Vehicle Routing and Break Scheduling

    OpenAIRE

    Meyer, Christoph Manuel; Kopfer, Herbert; Kok, Adrianus Leendert; Schutten, Marco

    2009-01-01

    The problem of combined vehicle routing and break scheduling comprises three subproblems: clustering of customer requests, routing of vehicles, and break scheduling. In practice, these subproblems are usually solved in the interaction between planners and drivers. We consider the case that the planner performs the clustering and the drivers perform the routing and break scheduling. To analyze this problem, we embed it into the framework of distributed decision making proposed by Schneeweiss (...

  1. Route Elimination Heuristic for Vehicle Routing Problem with Time Windows

    Directory of Open Access Journals (Sweden)

    Sándor Csiszár

    2005-11-01

    Full Text Available The paper deals with the design of a route elimination (RE algorithm for thevehicle routing problem with time windows (VRPTW. The problem has two objectives, oneof them is the minimal number of routes the other is the minimal cost. To cope with theseobjectives effectively two-phase solutions are often suggested in the relevant literature. Inthe first phase the main focus is the route elimination, in the second one it is the costreduction. The algorithm described here is a part of a complete VRPWT study. The methodwas developed by studying the graph behaviour during the route elimination. For thispurpose a model -called “Magic Bricks” was developed. The computation results on theSolomon problem set show that the developed algorithm is competitive with the best ones.

  2. The price of commitment in online stochastic vehicle routing

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Russell W [Los Alamos National Laboratory; Van Hentenryck, Pascal [BROWN UNIV

    2009-01-01

    This paper considers online stochastic multiple vehicle routing with time windows in which requests arrive dynamically and the goal is to maximize the number of serviced customers. Early work has focused on very flexible routing settings where the decision to assign a vehicle to a customer is delayed until a vehicle is actually deployed to the customer. Motivated by real applications that require stability in the decision making, this paper considers a setting where the decision to assign a customer request to a vehicle must be taken when that request is accepted. Experimental results suggest that this constraint severely degrades the performance of existing algorithms. However, the paper shows how the use of stochastic information for vehicle assignment and request acceptance improves decision quality considerably. Moreover, the use of resource augmentation quantifies precisely the cost of commitment in online vehicle routing.

  3. Multiple Charging Station Location-Routing Problem with Time Window of Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Wang Li-ying

    2015-11-01

    Full Text Available This paper presents the electric vehicle (EV multiple charging station location-routing problem with time window to optimize the routing plan of capacitated EVs and the strategy of charging stations. In particular, the strategy of charging stations includes both infrastructure-type selection and station location decisions. The problem accounts for two critical constraints in logistic practice: the vehicle loading capacity and the customer time windows. A hybrid heuristic that incorporates an adaptive variable neighborhood search (AVNS with the tabu search algorithm for intensification was developed to address the problem. The specialized neighborhood structures and the selection methods of charging station used in the shaking step of AVNS were proposed. In contrast to the commercial solver CPLEX, experimental results on small-scale test instances demonstrate that the algorithm can find nearly optimal solutions on small-scale instances. The results on large-scale instances also show the effectiveness of the algorithm.

  4. Optimizing investment fund allocation using vehicle routing problem framework

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita

    2014-07-01

    The objective of investment is to maximize total returns or minimize total risks. To determine the optimum order of investment, vehicle routing problem method is used. The method which is widely used in the field of resource distribution shares almost similar characteristics with the problem of investment fund allocation. In this paper we describe and elucidate the concept of using vehicle routing problem framework in optimizing the allocation of investment fund. To better illustrate these similarities, sectorial data from FTSE Bursa Malaysia is used. Results show that different values of utility for risk-averse investors generate the same investment routes.

  5. Routing of Electric Vehicles: City Distribution in Copenhagen

    DEFF Research Database (Denmark)

    Linde, Esben; Larsen, Allan; Nørrelund, Anders Vedsted;

    . The objective is to find the least cost plan for EV routing and compare this to conventional routing. A heuristic method is developed and tested on data based on real-life collected data on distribution vehicles in central Copenhagen, Denmark. The EVRPTW has so far received little attention in the literature......In this work, a Vehicle Routing Problem with Time Windows considering EV constraints of limited driving range and freight capacity is addressed (EVRPTW). The EVs are allowed to recharge at certain locations, and aspects of intelligent location of these recharging points are considered...

  6. Partially dynamic vehicle routing - models and algorithms

    DEFF Research Database (Denmark)

    Larsen, Allan; Madsen, Oli B.G.; Solomon, M.

    2002-01-01

    In this paper we propose a framework for dynamic routing systems based on their degree of dynamism. Next, we consider its impact on solution methodology and quality. Specifically, we introduce the Partially Dynamic Travelling Repairman Problem and describe several dynamic policies to minimize...... routing costs. The results of our computational study indicate that increasing the dynamic level results in a linear increase in route length for all policies studied. Furthermore, a Nearest Neighbour policy performed, on the average, uniformly better than the other dispatching rules studied. Among these...

  7. The Vehicle Routing Problem with Time Windows and Temporal Dependencies

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Dohn, Anders Høeg; Larsen, Jesper

    the schedule for each technician must respect a number of synchronization constraints with other schedules. The problem is solved using metaheuristics. Another application with synchronization between visits is in ground handling at airports. Teams drive around at the airport and are assigned tasks...... assignment and routing problem with synchronization constraints. The problem has been solved by column generation. The synchronized vehicle dispatching problem (SVDP), which is a dynamic vehicle routing problem with synchronization between vehicles. Constraint programming and local search are applied...... to be scheduled with a certain slack between them. They refer to the vehicle problem as having interdependent time windows. Temporal dependencies have been modeled for a home care routing problem in a mixed integer programming model (MIP) which was solved with a standard MIP solver. An application with general...

  8. New Lower Bounds on the Number of Vehicles for the Vehicle Routing Problem with Time Windows

    OpenAIRE

    Afifi, Sohaib; Guibadj, Rym Nesrine; Moukrim, Aziz

    2014-01-01

    International audience; The Vehicle Routing Problem with Time Windows (VRPTW) consists in determining the routing plan of vehicles with identical capacity in order to supply the demands of a set of customers with predefined time windows. This complex multi-constrained problem has been widely studied due to its industrial, economic and environmental implications. In this work, we are interested in defining the number of vehicles needed to visit all the customers. This objective is very importa...

  9. A Subpath Ejection Method for the Vehicle Routing Problem

    OpenAIRE

    César Rego

    1998-01-01

    Generically, ejection chains are methods conceived to allow solution transformations to be efficiently carried out by modifying a variable number of their components at each step of a local search algorithm. We consider a subpath ejection chain method for the vehicle routing problem (VRP) under capacity and route length restrictions. The method undertakes the identification of a substructure named the flower reference structure which, besides coordinating moves during an ejection chain constr...

  10. Parallelization of the Vehicle Routing Problem with Time Windows

    DEFF Research Database (Denmark)

    Larsen, Jesper

    1999-01-01

    This dissertation presents a number of algorithms for solving the Vehicle Routing Problem with Time Windows (VRPTW). The VRPTW is a generalization of the well known capacity constrained Vehicle Routing Problem (VRP). In the VRP a fleet of vehicles based at a central depot must service a set...... of customers. In the VRPTW each customer has a time window. Service of a customer must begin within the interval given by the time window. The objective is to minimize some aspect of operating costs (e.g. total distance traveled, number of vehicles needed or a combination of parameters). Since the late 80's...... and the beginning of the 90's optimal methods for the VRPTW have appeared in the literature. Methods have basicly been based on three approaches: dynamic programming, Lagrange relaxation and column generation (Dantzig-Wolfe). The most successful approaches rely on column generation. Good results have also been...

  11. Heuristics for Routing Heterogeneous Unmanned Vehicles with Fuel Constraints

    Directory of Open Access Journals (Sweden)

    David Levy

    2014-01-01

    Full Text Available This paper addresses a multiple depot, multiple unmanned vehicle routing problem with fuel constraints. The objective of the problem is to find a tour for each vehicle such that all the specified targets are visited at least once by some vehicle, the tours satisfy the fuel constraints, and the total travel cost of the vehicles is a minimum. We consider a scenario where the vehicles are allowed to refuel by visiting any of the depots or fuel stations. This is a difficult optimization problem that involves partitioning the targets among the vehicles and finding a feasible tour for each vehicle. The focus of this paper is on developing fast variable neighborhood descent (VND and variable neighborhood search (VNS heuristics for finding good feasible solutions for large instances of the vehicle routing problem. Simulation results are presented to corroborate the performance of the proposed heuristics on a set of 23 large instances obtained from a standard library. These results show that the proposed VND heuristic, on an average, performed better than the proposed VNS heuristic for the tested instances.

  12. Vehicle routing with cross-docking

    DEFF Research Database (Denmark)

    Wen, Min; Larsen, Jesper; Clausen, Jens;

    2009-01-01

    a set of homogeneous vehicles are used to transport orders from the suppliers to the corresponding customers via a cross-dock. The orders can be consolidated at the cross-dock but cannot be stored for very long because the cross-dock does not have long-term inventory-holding capabilities. The objective...... of the VRPCD is to minimize the total travel time while respecting time window constraints at the nodes and a time horizon for the whole transportation operation. In this paper, a mixed integer programming formulation for the VRPCD is proposed. A tabu search heuristic is embedded within an adaptive memory...... values) within very short computational time....

  13. The dynamic multi-period vehicle routing problem

    DEFF Research Database (Denmark)

    Wen, Min; Cordeau, Jean-Francois; Laporte, Gilbert;

    2010-01-01

    This paper considers the Dynamic Multi-Period Vehicle Routing Problem which deals with the distribution of orders from a depot to a set of customers over a multi-period time horizon. Customer orders and their feasible service periods are dynamically revealed over time. The objectives...

  14. The Dynamic Multi-Period Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Wen, Min; Cordeau, Jean-Francois; Laporte, Gilbert;

    This paper considers the Dynamic Multi-Period Vehicle Routing Problem which deals with the distribution of orders from a depot to a set of customers over a multi-period time horizon. Customer orders and their feasible service periods are dynamically revealed over time. The objectives...

  15. Genetic Algorithm for Vehicle Routing Problem with Backhauls

    Directory of Open Access Journals (Sweden)

    W.Nurfahizul Ifwah. WA

    2012-07-01

    Full Text Available The Vehicle Routing Problem with Backhauls (VRPB is an extension of the classical Vehicle Routing Problem (VRP that includes both a set of customers to whom products are to be delivered and a set of suppliers whose goods need to be transported back to the distribution center. In addition, on each route all deliveries have to be made before any goods can be picked up to avoid rearranging the loads on the vehicle. The main objective for VRPB is to determine the network route to minimize the total cost, distance or time. There are a few methods that can be identified to solve this VRPB. The objective of this research is to present a heuristic method, called Genetic Algorithm (GA, for the VRPB. In brief, GA is a system developing methods that use the natural principle of a genetic population and involved three main processes that is crossover, mutation and inversion. GA implementation on the 68 nodes problems taken from Goetschalckx and Jacobs- Blecha is done by using Microsoft C++ Programming. Solutions to the problem are presented and performance comparison is conducted with the existing best solution. Several parameters in GA will be tested such as population size, crossover point and also the choice of operators used.

  16. ACTIVITY-BASED COSTING FOR VEHICLE ROUTING PROBLEMS

    Directory of Open Access Journals (Sweden)

    A. J. Moolman

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT:Activity-based costing (ABC is a costing model that identifies activity costs in an organisation. It assigns the cost of activity resources to generate the actual cost of products in order to eliminateunprofitable products and to lowerthe prices of overpriced ones. The vehicle routing problem (VRP is a combinatorial optimisation and nonlinear programming problem that seeks to service a number of customers with a fleet of vehicles in a cost-effective manner. In this article we propose a new approach to determine costing for vehicle routing type problems. The methodology incorporates the predictive sharing of a resource by clustering producers.

    AFRIKAANSE OPSOMMING: ‘Activity-based costing’ (ABC is ’n kostemodel wat die aktiwiteitskoste in ’n organisasie identifiseer. Dit allokeer die koste van die bronne sodat die ware koste van die vervaardiging en dienste van die produk bereken kan word om winsgewendheid te bepaal. Die ‘vehicle routing problem’ (VRP is ’n kombinatoriese optimisering en nie-lineêre programmeringsprobleem wat verskeie kliënte met ’n vloot voertuie in die mees koste- effektiewe manier bedien. Die artikel bespreek ’n nuwe metode om die kombinasie van probleme op te los. Die metode maak gebruik van groeperingsalgoritmes om meer akkurate voertuig deling te voorspel.

  17. Performansi Algoritma CODEQ dalam Penyelesaian Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Annisa Kesy Garside

    2014-01-01

    Full Text Available Genetic Algorithm, Tabu Search, Simulated Annealing, and Ant Colony Optimization showed a good performance in solving vehicle routing problem. However, the generated solution of those algorithms was changeable regarding on the input parameter of each algorithm. CODEQ is a new, parameter free meta-heuristic algorithm that had been successfully used to solve constrained optimization problems, integer programming, and feed-forward neural network. The purpose of this research are improving CODEQ algorithm to solve vehicle routing problem and testing the performance of the improved algorithm. CODEQ algorithm is started with population initiation as initial solution, generated of mutant vector for each parent in every iteration, replacement of parent by mutant when fitness function value of mutant is better than parent’s, generated of new vector for each iteration based on opposition value or chaos principle, replacement of worst solution by new vector when fitness function value of new vector is better, iteration ceasing when stooping criterion is achieved, and sub-tour determination based on vehicle capacity constraint. The result showed that the average deviation of the best-known and the best-test value is 6.35%. Therefore, CODEQ algorithm is good in solving vehicle routing problem.

  18. Solving Vehicle Routing with Full Container Load and Time Windows

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander; Spoorendonk, Simon; Pisinger, David

    2012-01-01

    A service provided by the liner shipping companies is the transport of containers by truck between the terminal and customers. These transports consist of import orders and export orders. Even though these transports concern containers and, therefore, each order is a full load, an import...... and an export order can be combined in one trip where the container is emptied at an import customer and taken to an export customer to be filled. Finding a set of optimal vehicle routes allowing these combinations is NP-hard. However, exploring the fact that the number of possible routes is small...

  19. Dynamic vehicle routing problems: Three decades and counting

    DEFF Research Database (Denmark)

    Psaraftis, Harilaos N.; Wen, Min; Kontovas, Christos A.

    2016-01-01

    Since the late 70s, much research activity has taken place on the class of dynamic vehicle routing problems (DVRP), with the time period after year 2000 witnessing a real explosion in related papers. Our paper sheds more light into work in this area over more than 3 decades by developing a taxonomy...... of DVRP papers according to 11 criteria. These are (1) type of problem, (2) logistical context, (3) transportation mode, (4) objective function, (5) fleet size, (6) time constraints, (7) vehicle capacity constraints, (8) the ability to reject customers, (9) the nature of the dynamic element, (10...

  20. The vehicle routing problem with time windows and temporal dependencies

    DEFF Research Database (Denmark)

    Dohn, Anders Høeg; Rasmussen, Matias Sevel; Larsen, Jesper

    2011-01-01

    In this article, we formulate the vehicle routing problem with time windows and temporal dependencies. The problem is an extension of the well studied vehicle routing problem with time windows. In addition to the usual constraints, a scheduled time of one visit may restrain the scheduling options...... on the relaxed master problems. Finally, a computational study is performed to quantitatively reveal strengths and weaknesses of the proposed formulations. It is concluded that, depending on the problem at hand, the best performance is achieved either by relaxing the generalized precedence constraints...... in the master problem, or by using a time‐indexed model, where generalized precedence constraints are added as cuts when they become severely violated. © 2011 Wiley Periodicals, Inc. NETWORKS, Vol. 58(4), 273–289 2011...

  1. Vehicle routing problem with time-varying speed

    Institute of Scientific and Technical Information of China (English)

    LIU Yun-zhong

    2010-01-01

    Vehicle routing problem with time-varying speed(VRPTS)is a generalization of vehicle routing problem in which the travel speed between two locations depends on the passing areas and the time of a day.This paper proposes a simple model for estimating time-varying travel speeds in VRPTS that relieves much bur den to the data-related problems.The study further presents three heuristics(saving technique,proximity priority searching technique,and insertion technique)for VRPTS,developed by extending and modifying the existing heuristics for conventional VRP.The results of computational experiments demonstrate that the proposed estimation model performs well and the saving technique is the best among the three heuristics.

  2. A green vehicle routing problem with customer satisfaction criteria

    Science.gov (United States)

    Afshar-Bakeshloo, M.; Mehrabi, A.; Safari, H.; Maleki, M.; Jolai, F.

    2016-08-01

    This paper develops an MILP model, named Satisfactory-Green Vehicle Routing Problem. It consists of routing a heterogeneous fleet of vehicles in order to serve a set of customers within predefined time windows. In this model in addition to the traditional objective of the VRP, both the pollution and customers' satisfaction have been taken into account. Meanwhile, the introduced model prepares an effective dashboard for decision-makers that determines appropriate routes, the best mixed fleet, speed and idle time of vehicles. Additionally, some new factors evaluate the greening of each decision based on three criteria. This model applies piecewise linear functions (PLFs) to linearize a nonlinear fuzzy interval for incorporating customers' satisfaction into other linear objectives. We have presented a mixed integer linear programming formulation for the S-GVRP. This model enriches managerial insights by providing trade-offs between customers' satisfaction, total costs and emission levels. Finally, we have provided a numerical study for showing the applicability of the model.

  3. STUDI TENTANG TRAVELLING SALESMAN DAN VEHICLE ROUTING PROBLEM DENGAN TIME WINDOWS

    Directory of Open Access Journals (Sweden)

    I Nyoman Sutapa

    2003-01-01

    Full Text Available The article shows the study of model development of travelling salesman problem. Three models are studied, i.e. travelling salesman problem with time windows, vehicle routing problem, and vehicle routing problem with time windows. Abstract in Bahasa Indonesia : Dalam artikel ini dipaparkan kajian mengenai pengembangan model travelling salesman problem. Ada tiga model yang dikaji yaitu travelling salesman problem dengan time windows, vehicle routing problem, serta vehicle routing problem dengan time windows. Kata-kunci: travelling salesman problem, vehicle routing problem, time windows.

  4. A Survey on Routing Mechanism and Techniques in Vehicle to Vehicle Communication (VANET

    Directory of Open Access Journals (Sweden)

    Yugal Kumar

    2011-02-01

    Full Text Available Now a day, one of the most attractive research topics in the area of Intelligent Traffic Control is Intervehiclecommunication. In V2V communication or we can also called VANET i.e. vehicular ad-hocnetwork; a vehicle can communicate to its neighboring vehicles even in the absence of a central BaseStation. The concept of this direct communication is to send vehicle safety messages one-to-one or oneto-many vehicles via wireless connection. Such messages are usually short in length and have very shortlifetime in which they must reach at the destination. The Inter-vehicle communication system is an adhocnetwork with high mobility and changing number of nodes, where mobile nodes dynamically createtemporary networks and transferring messages from one node to others by using multiple hops due tolimitation of short range. The routing in vehicular Ad hoc Networks (VANET has attracted manyattentions during the last few years. So in this paper we are focusing on the routing concept for theVANET i.e. principles for routing, decomposition of the routing function and requirement. The datadelivery through Vehicular Ad-hoc Networks is challenging since it must efficiently handle rapidtopology changes and a fragmented network.

  5. Intelligent emission-sensitive routing for plugin hybrid electric vehicles.

    Science.gov (United States)

    Sun, Zhonghao; Zhou, Xingshe

    2016-01-01

    The existing transportation sector creates heavily environmental impacts and is a prime cause for the current climate change. The need to reduce emissions from this sector has stimulated efforts to speed up the application of electric vehicles (EVs). A subset of EVs, called plug-in hybrid electric vehicles (PHEVs), backup batteries with combustion engine, which makes PHEVs have a comparable driving range to conventional vehicles. However, this hybridization comes at a cost of higher emissions than all-electric vehicles. This paper studies the routing problem for PHEVs to minimize emissions. The existing shortest-path based algorithms cannot be applied to solving this problem, because of the several new challenges: (1) an optimal route may contain circles caused by detour for recharging; (2) emissions of PHEVs not only depend on the driving distance, but also depend on the terrain and the state of charge (SOC) of batteries; (3) batteries can harvest energy by regenerative braking, which makes some road segments have negative energy consumption. To address these challenges, this paper proposes a green navigation algorithm (GNA) which finds the optimal strategies: where to go and where to recharge. GNA discretizes the SOC, then makes the PHEV routing problem to satisfy the principle of optimality. Finally, GNA adopts dynamic programming to solve the problem. We evaluate GNA using synthetic maps generated by the delaunay triangulation. The results show that GNA can save more than 10 % energy and reduce 10 % emissions when compared to the shortest path algorithm. We also observe that PHEVs with the battery capacity of 10-15 KWh detour most and nearly no detour when larger than 30 KWh. This observation gives some insights when developing PHEVs.

  6. Intelligent emission-sensitive routing for plugin hybrid electric vehicles.

    Science.gov (United States)

    Sun, Zhonghao; Zhou, Xingshe

    2016-01-01

    The existing transportation sector creates heavily environmental impacts and is a prime cause for the current climate change. The need to reduce emissions from this sector has stimulated efforts to speed up the application of electric vehicles (EVs). A subset of EVs, called plug-in hybrid electric vehicles (PHEVs), backup batteries with combustion engine, which makes PHEVs have a comparable driving range to conventional vehicles. However, this hybridization comes at a cost of higher emissions than all-electric vehicles. This paper studies the routing problem for PHEVs to minimize emissions. The existing shortest-path based algorithms cannot be applied to solving this problem, because of the several new challenges: (1) an optimal route may contain circles caused by detour for recharging; (2) emissions of PHEVs not only depend on the driving distance, but also depend on the terrain and the state of charge (SOC) of batteries; (3) batteries can harvest energy by regenerative braking, which makes some road segments have negative energy consumption. To address these challenges, this paper proposes a green navigation algorithm (GNA) which finds the optimal strategies: where to go and where to recharge. GNA discretizes the SOC, then makes the PHEV routing problem to satisfy the principle of optimality. Finally, GNA adopts dynamic programming to solve the problem. We evaluate GNA using synthetic maps generated by the delaunay triangulation. The results show that GNA can save more than 10 % energy and reduce 10 % emissions when compared to the shortest path algorithm. We also observe that PHEVs with the battery capacity of 10-15 KWh detour most and nearly no detour when larger than 30 KWh. This observation gives some insights when developing PHEVs. PMID:27026933

  7. Dynamic route guidance strategy in a two-route pedestrian-vehicle mixed traffic flow system

    Science.gov (United States)

    Liu, Mianfang; Xiong, Shengwu; Li, Bixiang

    2016-05-01

    With the rapid development of transportation, traffic questions have become the major issue for social, economic and environmental aspects. Especially, during serious emergencies, it is very important to alleviate road traffic congestion and improve the efficiency of evacuation to reduce casualties, and addressing these problems has been a major task for the agencies responsible in recent decades. Advanced road guidance strategies have been developed for homogeneous traffic flows, or to reduce traffic congestion and enhance the road capacity in a symmetric two-route scenario. However, feedback strategies have rarely been considered for pedestrian-vehicle mixed traffic flows with variable velocities and sizes in an asymmetric multi-route traffic system, which is a common phenomenon in many developing countries. In this study, we propose a weighted road occupancy feedback strategy (WROFS) for pedestrian-vehicle mixed traffic flows, which considers the system equilibrium to ease traffic congestion. In order to more realistic simulating the behavior of mixed traffic objects, the paper adopted a refined and dynamic cellular automaton model (RDPV_CA model) as the update mechanism for pedestrian-vehicle mixed traffic flow. Moreover, a bounded rational threshold control was introduced into the feedback strategy to avoid some negative effect of delayed information and reduce. Based on comparisons with the two previously proposed strategies, the simulation results obtained in a pedestrian-vehicle traffic flow scenario demonstrated that the proposed strategy with a bounded rational threshold was more effective and system equilibrium, system stability were reached.

  8. Meta Heuristic Algorithms for Vehicle Routing Problem with Stochastic Demands

    Directory of Open Access Journals (Sweden)

    Geetha Shanmugam

    2011-01-01

    Full Text Available Problem statement: The shipment of goods from manufacturer to the consumer is a focal point of distribution logistics. In reality, the demand of consumers is not known a priori. This kind of distribution is dealt by Stochastic Vehicle Routing Problem (SVRP which is a NP-hard problem. In this proposed work, VRP with stochastic demand is considered. A probability distribution is considered as a random variable for stochastic demand of a customer. Approach: In this study, VRPSD is resolved using Meta heuristic algorithms such as Genetic Algorithm (GA, Particle Swarm Optimization (PSO and Hybrid PSO (HPSO. Dynamic Programming (DP is used to find the expected cost of each route generated by GA, PSO and HPSO. Results: The objective is to minimize the total expected cost of a priori route. The fitness value of a priori route is calculated using DP. In proposed HPSO, the initial particles are generated based Nearest Neighbor Heuristic (NNH. Elitism is used in HPSO for updating the particles. The algorithm is implemented using MATLAB7.0 and tested with problems having different number of customers. The results obtained are competitive in terms of execution time and memory usage. Conclusion: The computational time is reduced as polynomial time as O(nKQ time and the memory required is O(nQ. The ANOVA test is performed to compare the proposed HPSO with other heuristic algorithms.

  9. SOLVING THE PROBLEM OF VEHICLE ROUTING BY EVOLUTIONARY ALGORITHM

    Directory of Open Access Journals (Sweden)

    Remigiusz Romuald Iwańkowicz

    2016-03-01

    Full Text Available In the presented work the vehicle routing problem is formulated, which concerns planning the collection of wastes by one garbage truck from a certain number of collection points. The garbage truck begins its route in the base point, collects the load in subsequent collection points, then drives the wastes to the disposal site (landfill or sorting plant and returns to the another visited collection points. The filled garbage truck each time goes to the disposal site. It returns to the base after driving wastes from all collection points. Optimization model is based on genetic algorithm where individual is the whole garbage collection plan. Permutation is proposed as the code of the individual.

  10. On the vehicle routing problem with time windows

    OpenAIRE

    Kallehauge, Brian; Madsen, Oli B.G.; Larsen, Jesper; Madsen, Kaj

    2006-01-01

    Den danske titel på denne afhandling er ‘Ruteplanlægningsproblemet med tidsvinduer’. Dette problem omhandler den optimale styring af en flåde af lastbiler mellem et lager og et antal kunder, der skal besøges inden for et bestemt tidsinterval, et såkaldt tidsvindue. Formålet med denne afhandling er udvikling af nye og effektive metoder til løsning af ruteplanlægningsproblemet med tidsvinduer (vehicle routing problem with time windows - VRPTW). Afhandlingen består af et afsnit af introducerende...

  11. Cooperative vehicle routing problem: an opportunity for cost saving

    Science.gov (United States)

    Zibaei, Sedighe; Hafezalkotob, Ashkan; Ghashami, Seyed Sajad

    2016-02-01

    In this paper, a novel methodology is proposed to solve a cooperative multi-depot vehicle routing problem. We establish a mathematical model for multi-owner VRP in which each owner (i.e. player) manages single or multiple depots. The basic idea consists of offering an option that owners cooperatively manage the VRP to save their costs. We present cooperative game theory techniques for cost saving allocations which are obtained from various coalitions of owners. The methodology is illustrated with a numerical example in which different coalitions of the players are evaluated along with the results of cooperation and cost saving allocation methods.

  12. International Workshop on Vehicle Routing in Practice (VIP’08) - Oppsummering

    OpenAIRE

    Hasle, Geir

    2008-01-01

    Den internasjonale konferansen Vehicle Routing in Practice 2008 (VIP’08) ble gjennomført på en meget vellykket måte 12.-14. juni 2008 på Soria Moria konferansehotell i Oslo. Workshopen hadde 28 deltakere, hvorav 15 meget anerkjente forskere fra utlandet og 13 fra de tre norske VRP-forskningsgruppene ved NTNU, Høgskolen i Molde og SINTEF. VIP’08 samlet erfarne forskere fra utlandet og Norge samt norske PhD og postdoktorstipendiater. Det var 25 foredrag inndelt i 8 sesjoner etter fagtema (en st...

  13. Reachability cuts for the vehicle routing problem with time windows

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    2004-01-01

    This paper introduces a class of cuts, called reachability cuts, for the Vehicle Routing Problem with Time Windows (VRPTW). Reachability cuts are closely related to cuts derived from precedence constraints in the Asymmetric Traveling Salesman Problem with Time Windows and to k-path cuts for the...... VRPTW. In particular, any reachability cut dominates one or more k-path cuts. The paper presents separation procedures for reachability cuts and reports computational experiments on well-known VRPTW instances. The computational results suggest that reachability cuts can be highly useful as cutting...

  14. Optimal Routing for Heterogeneous Fixed Fleets of Multicompartment Vehicles

    Directory of Open Access Journals (Sweden)

    Qian Wang

    2014-01-01

    Full Text Available We present a metaheuristic called the reactive guided tabu search (RGTS to solve the heterogeneous fleet multicompartment vehicle routing problem (MCVRP, where a single vehicle is required for cotransporting multiple customer orders. MCVRP is commonly found in delivery of fashion apparel, petroleum distribution, food distribution, and waste collection. In searching the optimum solution of MCVRP, we need to handle a large amount of local optima in the solution spaces. To overcome this problem, we design three guiding mechanisms in which the search history is used to guide the search. The three mechanisms are experimentally demonstrated to be more efficient than the ones which only apply the known distance information. Armed with the guiding mechanisms and the well-known reactive mechanism, the RGTS can produce remarkable solutions in a reasonable computation time.

  15. Analysis of the single-vehicle cyclic inventory routing problem

    Science.gov (United States)

    Aghezzaf, El-Houssaine; Zhong, Yiqing; Raa, Birger; Mateo, Manel

    2012-11-01

    The single-vehicle cyclic inventory routing problem (SV-CIRP) consists of a repetitive distribution of a product from a single depot to a selected subset of customers. For each customer, selected for replenishments, the supplier collects a corresponding fixed reward. The objective is to determine the subset of customers to replenish, the quantity of the product to be delivered to each and to design the vehicle route so that the resulting profit (difference between the total reward and the total logistical cost) is maximised while preventing stockouts at each of the selected customers. This problem appears often as a sub-problem in many logistical problems. In this article, the SV-CIRP is formulated as a mixed-integer program with a nonlinear objective function. After a thorough analysis of the structure of the problem and its features, an exact algorithm for its solution is proposed. This exact algorithm requires only solutions of linear mixed-integer programs. Values of a savings-based heuristic for this problem are compared to the optimal values obtained for a set of some test problems. In general, the gap may get as large as 25%, which justifies the effort to continue exploring and developing exact and approximation algorithms for the SV-CIRP.

  16. Vehicle routing for the last mile of power system restoration

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Russell W [Los Alamos National Laboratory; Coffrin, Carleton [Los Alamos National Laboratory; Van Hentenryck, Pascal [BROWN UNIV.

    2010-11-23

    This paper studied a novel problem in power system restoration: the Power Restoration Vehicle Routing Problem (PRVRP). The goal of PRVRPs is to decide how coordinate repair crews effectively in order to recover from blackouts as fast as possible after a disaster has occurred. PRVRPs are complex problems that combine vehicle routing and power restoration scheduling problems. The paper proposed a multi-stage optimization algorithm based on the idea of constraint injection that meets the aggressive runtime constraints necessary for disaster recovery. The algorithms were validated on benchmarks produced by the Los Alamos National Laboratory, using the infrastructure of the United States. The disaster scenarios were generated by state-of-the-art hurricane simulation tools similar to those used by the National Hurricane Center. Experimental results show that the constraint-injection algorithms can reduce the blackouts by 50% or more over field practices. Moreover, the results show that the constraint-injection algorithm using large neighborhood search over a blackbox simulator provide competitive quality and scales better than using a MIP solver on the subproblems.

  17. Analyzing combined vehicle routing and break scheduling from a distributed decision making perspective

    OpenAIRE

    C.M. Meyer; Kok, A.L.; H Kopfer; Schutten, J.M.J.

    2009-01-01

    We analyze the problem of combined vehicle routing and break scheduling from a distributed decision making perspective. The problem of combined vehicle routing and break scheduling can be defined as the problem of finding vehicle routes to serve a set of customers such that a cost criterion is minimized and legal rules on driving and working hours are observed. In the literature, this problem is always analyzed from a central planning perspective. In practice, however, this problem is solved ...

  18. Design of a Capacitive Flexible Weighing Sensor for Vehicle WIM System

    Directory of Open Access Journals (Sweden)

    Qing Li

    2007-08-01

    Full Text Available With the development of the Highway Transportation and Business Trade, vehicle weigh-in-motion (WIM technology has become a key technology and trend of measuring traffic loads. In this paper, a novel capacitive flexible weighing sensor which is light weight, smaller volume and easy to carry was applied in the vehicle WIM system. The dynamic behavior of the sensor is modeled using the Maxwell-Kelvin model because the materials of the sensor are rubbers which belong to viscoelasticity. A signal processing method based on the model is presented to overcome effects of rubber mechanical properties on the dynamic weight signal. The results showed that the measurement error is less than ���±10%. All the theoretic analysis and numerical results demonstrated that appliance of this system to weigh in motion is feasible and convenient for traffic inspection.

  19. Assessment of the forest landscape along selected motor vehicle routes

    Directory of Open Access Journals (Sweden)

    Janeczko Emilia

    2016-03-01

    Full Text Available This paper presents the results of research that aims to analyse and evaluate the attractiveness of the forest landscape in the vicinity of selected motor vehicle routes that differ in terms of technical parameters, such as motorways, regional roads and local (municipal roads. The diversity of landscape units was used as the measure of landscape attractiveness. Landscape diversity analysis allows to establish the details related to specific parts of the road and the options for configuring the road environment. These options relate to the way the forest is managed and mainly involve aspects of infrastructure and cultivation. They include activities such as afforestation work and rebuilding the species composition of forest stands. According to the research, the lower the technical class of a road, the greater is the need to take action to adapt the structural-tree stand system to meet the safety requirements of road users.

  20. Formulations and Branch-and-Cut Algorithms for the Generalized Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Bektas, Tolga; Erdogan, Günes; Røpke, Stefan

    2011-01-01

    The Generalized Vehicle Routing Problem (GVRP) consists of nding a set of routes for a number of vehicles with limited capacities on a graph with the vertices partitioned into clusters with given demands such that the total cost of travel is minimized and all demands are met. This paper offers four...

  1. Speeding up the solution process for the Vehicle Routing Problem with Time Windows using structural information

    DEFF Research Database (Denmark)

    Larsen, Jesper

    2002-01-01

    Two ideas for using structural information for solving the Vehicle Routing Problem with Time Windows (VRPTW) is presented. The VRPTW is a generalization of the well known capacity constrained Vehicle Routing Problem (VRP). Both techniques are based on solving the VRPTW using a Branch...

  2. Design of Vehicle Routing by Integrating Optimization and Simulated Annealing Approach

    Institute of Scientific and Technical Information of China (English)

    Chwen-Tzeng; Su; Chikong; Hwang

    2002-01-01

    The vehicle routing problem (VRP) can be described as the problem of designing the optimal delivery or collection routes from one or several depots to a number of geographically scattered customers, subject to load constraints. The routing decision involves determining which of the demand s will be satisfied by each vehicle and what route each vehicle will follow in s erving its assigned demand in order to minimize total delivery cost. In this pap er, a methodology for the design of VRP by integrating...

  3. A Hybrid TCNN Optimization Approach for the Capacity Vehicle Routing Problem

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel approximation algorithm was proposed for the problem of finding the minimum total cost of all routes in Capacity Vehicle Routing Problem (CVRP). CVRP can be partitioned into three parts: the selection of vehicles among the available vehicles, the initial routing of the selected fleet and the routing optimization. Fuzzy Cmeans (FCM) can group the customers with close Euclidean distance into the same vehicle according to the principle of similar feature partition. Transiently chaotic neural network (TCNN) combines local search and global search, possessing high search efficiency. It will solve the routes to near optimality. A simple tabu search (TS)procedure can improve the routes to more optimality. The computations on benchmark problems and comparisons with other results in literatures show that the proposed algorithm is a viable and effective approach for CVRP.

  4. Research on multi-objective emergency logistics vehicle routing problem under constraint conditions

    OpenAIRE

    Miaomiao Du; Hua Yi

    2013-01-01

    Purpose: Aim at choosing a relative good vehicle routing in emergency conditions under constraint conditions when disaster happens. Rapid response and rescue can save a lot of people. Design/methodology/approach: Modeling analysis: establishing a mathematical model of multi-objective emergency logistics vehicle routing problem. And in end of the paper, we intend to use genetic algorithms to solve the problem. Findings: Considering time requirement and cost limit both while choosing vehicle ro...

  5. A heterogeneous fleet vehicle routing model for solving the LPG distribution problem: A case study

    International Nuclear Information System (INIS)

    Vehicle Routing Problem (VRP) is an important management problem in the field of distribution and logistics. In VRPs, routes from a distribution point to geographically distributed points are designed with minimum cost and considering customer demands. All points should be visited only once and by one vehicle in one route. Total demand in one route should not exceed the capacity of the vehicle that assigned to that route. VRPs are varied due to real life constraints related to vehicle types, number of depots, transportation conditions and time periods, etc. Heterogeneous fleet vehicle routing problem is a kind of VRP that vehicles have different capacity and costs. There are two types of vehicles in our problem. In this study, it is used the real world data and obtained from a company that operates in LPG sector in Turkey. An optimization model is established for planning daily routes and assigned vehicles. The model is solved by GAMS and optimal solution is found in a reasonable time

  6. A heterogeneous fleet vehicle routing model for solving the LPG distribution problem: A case study

    Science.gov (United States)

    Onut, S.; Kamber, M. R.; Altay, G.

    2014-03-01

    Vehicle Routing Problem (VRP) is an important management problem in the field of distribution and logistics. In VRPs, routes from a distribution point to geographically distributed points are designed with minimum cost and considering customer demands. All points should be visited only once and by one vehicle in one route. Total demand in one route should not exceed the capacity of the vehicle that assigned to that route. VRPs are varied due to real life constraints related to vehicle types, number of depots, transportation conditions and time periods, etc. Heterogeneous fleet vehicle routing problem is a kind of VRP that vehicles have different capacity and costs. There are two types of vehicles in our problem. In this study, it is used the real world data and obtained from a company that operates in LPG sector in Turkey. An optimization model is established for planning daily routes and assigned vehicles. The model is solved by GAMS and optimal solution is found in a reasonable time.

  7. The Electric Fleet Size and Mix Vehicle Routing Problem with Time Windows and Recharging Stations

    DEFF Research Database (Denmark)

    Hiermann, Gerhard; Puchinger, Jakob; Røpke, Stefan;

    2016-01-01

    detours to recharging stations necessary, thus requiring efficient tour planning mechanisms in order to sustain the competitiveness of electric vehicles compared to conventional vehicles. We introduce the Electric Fleet Size and Mix Vehicle Routing Problem with Time Windows and Recharging Stations (E......-FSMFTW) to model decisions to be made with regards to fleet composition and the actual vehicle routes including the choice of recharging times and locations. The available vehicle types differ in their transport capacity, battery size and acquisition cost. Furthermore, we consider time windows at customer...

  8. Location and multi-depot vehicle routing for emergency vehicles using tour coverage and random sampling

    Directory of Open Access Journals (Sweden)

    Alireza Goli

    2015-09-01

    Full Text Available Distribution and optimum allocation of emergency resources are the most important tasks, which need to be accomplished during crisis. When a natural disaster such as earthquake, flood, etc. takes place, it is necessary to deliver rescue efforts as quickly as possible. Therefore, it is important to find optimum location and distribution of emergency relief resources. When a natural disaster occurs, it is not possible to reach some damaged areas. In this paper, location and multi-depot vehicle routing for emergency vehicles using tour coverage and random sampling is investigated. In this study, there is no need to visit all the places and some demand points receive their needs from the nearest possible location. The proposed study is implemented for some randomly generated numbers in different sizes. The preliminary results indicate that the proposed method was capable of reaching desirable solutions in reasonable amount of time.

  9. REFINEMENTS OF THE COLUMN GENERATION PROCESS FOR THE VEHICLE ROUTING PROBLEM WITH TIME WINDOWS

    Institute of Scientific and Technical Information of China (English)

    Jesper LARSEN

    2004-01-01

    The Vehicle Routing Problem with Time Windows is a generalization of the well known capacity constrained Vehicle Routing Problem. A homogeneous fleet of vehicles has to service a set of customers. The service of the customers can only start within a well-defined time interval denoted the time window. The objective is to determine routes for the vehicles that minimizes the accumulated cost (or distance). Currently the best approaches for determining optimal solutions are based on column generation and Branch-and-Bound, also known as Branch-and-Price. This paper presents two ideas for run-time improvements of the Branch-and-Price framework for the Vehicle Routing Problem with Time Windows. Both ideas reveal a significant potential for run-time refinements when speeding up an exact approach without compromising optimality.

  10. A sequential insertion heuristic for the vehicle routing problem with time windows with relatively few customers per route

    OpenAIRE

    DULLAERT, Wout

    2000-01-01

    In this paper we study the performance of Solomon’s (1987) sequential insertion heuristic |1, for Vehicle Routing Problems with Time Windows (VRPTWs) in which the number of customers per rout is small with respect to the customers’ time windows and the scheduling horizon. Solomon’s (1987) time insertion c12 (i, u, j) underestimates the additional time needed of inserting a new customer u between the depot, i= i0 and the first customer j in the partially constructed rout (i0= I, i1=j,i1,…,im)....

  11. An Analytical Model Formulation To Enhance The Green Logistics (GL Operations: From The Perspective Of Vehicle Routing Problem (VRP

    Directory of Open Access Journals (Sweden)

    Reshani P. Liyanage

    2016-08-01

    Full Text Available This paper is focused on the growing need of integrating environmentally sound choices into supply-chain management. The concept of green economic practices driven by the environmental sustainability challenges posed the concept of green logistics, to evolve in the last few decades.To establish the field further, the purpose of this paper is twofold. First, it offers anextensive systematic review of literature on GL with a critical review of the studies that have been considered in the paper.Second, it offers a conceptual analytical model where the canonical capacitated vehicle routing problem is extended to add the measures of Carbon Dioxide (CO2 emissions. The proposed, multi objective optimization model tackles the conflicting objectives of CO2 emission reduction and cost minimization. The developed generic model integrates the traffic information in providing the user with opportunity to have more realistic solution. The model also enables strategic decision making to improve the GL operations while allowing greatercompetitive advantage

  12. The waste collection vehicle routing problem with time windows in a city logistics context

    DEFF Research Database (Denmark)

    Buhrkal, Katja Frederik; Larsen, Allan; Røpke, Stefan

    2012-01-01

    Collection of waste is an important logistic activity within any city. In this paper we study how to collect waste in an efficient way. We study the Waste Collection Vehicle Routing Problem with Time Window which is concerned with finding cost optimal routes for garbage trucks such that all garba...

  13. The Time-Dependent Multiple-Vehicle Prize-Collecting Arc Routing Problem

    DEFF Research Database (Denmark)

    Black, Daniel; Eglese, Richard; Wøhlk, Sanne

    2015-01-01

    In this paper, we introduce a multi vehicle version of the Time-Dependent Prize-Collecting Arc Routing Problem (TD-MPARP). It is inspired by a situation where a transport manager has to choose between a number of full truck load pick-ups and deliveries to be performed by a fleet of vehicles. Real...

  14. A Branch-and-Price Algorithm for Two Multi-Compartment Vehicle Routing Problems

    DEFF Research Database (Denmark)

    Mirzaei, Samira; Wøhlk, Sanne

    2016-01-01

    Despite the vast body of literature on vehicle routing problems, little attention has been paid to multi-compartment vehicle routing problems that investigate transportation of different commodities on the same vehicle, but in different compartments. In this project, we present two strategically...... different versions of the MCVRP in general settings. In the first version, different commodities may be delivered to the customer by different vehicles, but the full amount of each product must be delivered by a single vehicle. In the second version, each customer may only be serviced by a single vehicle......, which must deliver the full amount of all commodities demanded by that customer. We present a Branch-and-Price algorithm for solving the two versions of the problem to optimality and we analyze the effect of the strategic decision of whether or not to allow multiple visits to the same customer...

  15. The Electric Fleet Size and Mix Vehicle Routing Problem with Time Windows and Recharging Stations

    OpenAIRE

    Hiermann, Gerhard; Puchinger, Jakob; Ropke, Stefan; Hartl, Richard F.

    2016-01-01

    International audience Due to new regulations and further technological progress in the field of electric vehicles, the research community faces the new challenge of incorporating the electric energy based restrictions into vehicle routing problems. One of these restrictions is the limited battery capacity which makes detours to recharging stations necessary, thus requiring efficient tour planning mechanisms in order to sustain the competitiveness of electric vehicles compared to conventio...

  16. A Routing Algorithm Based on Dynamic Forecast of Vehicle Speed and Position in VANET

    OpenAIRE

    Shukui Zhang; Haojing Huang

    2013-01-01

    Considering city road environment as the background, by researching GPSR greedy algorithm and the movement characteristics of vehicle nodes in VANET, this paper proposes the concept of circle changing trends angle in vehicle speed fluctuation curve and the movement domain and designs an SWF routing algorithm based on the vehicle speed point forecasted and the changing trends time computation. Simulation experiments are carried out through using a combination of NS-2 and VanetMobiSim software....

  17. A VEHICLE ROUTING PLANNING SYSTEM FOR GOODS DISTRIBUTION IN URBAN AREAS USING GOOGLE MAPS AND GENETIC ALGORITHM

    Directory of Open Access Journals (Sweden)

    Teodor Dimitrov Berov

    2016-06-01

    Full Text Available This article presents a system aimed at generating optimized vehicles routes - the vehicle routing problem with time windows (VRPTW based on using a Google Maps™ network data and imperialist competitive algorithm meta-heuristic. The vehicle routing problem with time windows is an important problem in the supply chain management. It copes with route scheduling and the distribution of goods from the distribution center to geographically dispersed customers in urban areas by a fleet of vehicles with constrained capacities. The system was tested for urban goods distribution in Sofia, Bulgaria - 35 retailers, warehouse, two types of vehicles (capacity and a working day.

  18. PERFORMANCE COMPARISON OF POSITION-BASED ROUTING PROTOCOLS IN VEHICLE-TOVEHICLE (V2V COMMUNICATION

    Directory of Open Access Journals (Sweden)

    SANJOY DAS

    2011-01-01

    Full Text Available Vehicular Ad hoc Networks (VANETs is the new wireless networking concept of the wireless ad hoc networks in the research community. Vehicle-to-Vehicle (V2V communication plays a significant role in providing a high level of safety and convenience to drivers and passengers. Routing in VANET is a major challenge and research area. Position based routing protocol has been identified to be suitable for VANETs because of frequently changed network topology and highly dynamic nature of vehicular nodes. Many position based routing protocols have been developed for routing messages in greedy orwarding way in VANETs. However, few of them are efficient when the network is highly dynamic. In this paper, we present an overview andqualitative comparison of existing position based routing protocols that are based on the position prediction of neighboring and destination nodes. We evaluate the performance metrics such as end-to-end delay and packet delivery ratio using NS-2 simulator.

  19. Northwest passage: Trade route for large air cushion vehicles

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

    A conceptual vehicle and powerplant (10,000-ton) nuclear-powered air-cushion vehicle (ACV) that could open the Northwest Passage and other Arctic passages to commercial traffic is identified. The report contains a description of the conceptual vehicle, including the powerplant and operations, an assessment of technical feasibility, estimates of capital and operating costs, and identification of eligible cargo and markets. A comparison of the nuclear ACV freighter with nuclear container ships shows that for containerized or roll-on/roll-off cargo the ACV would provide greatly reduced transit time between North Atlantic and North Pacific ports at a competitive cost.

  20. Distributed stochastic multi-vehicle routing in the Euclidean plane with no communications

    Science.gov (United States)

    Pietrabissa, Antonio

    2016-08-01

    This paper presents an algorithm for the multi-vehicle routing problem with no communications among the vehicles. The scenario consists in a convex Euclidean mission space, where targets are generated according to a Poisson distribution in time and to a generic continuous spatial distribution. The targets must be visited by the vehicles, which, therefore, must act in coordination. Even if no communications are required, the proposed routing strategy succeeds in effectively partitioning the mission space among the vehicles: at low target generation rates, the algorithm leads to the well-known centroidal Voronoi tessellation, whereas at high target generation rates, simulation results show that it has better performances with respect to a reference algorithm with no communications among vehicles.

  1. ROUTE OPTIMIZATION TO INCREASE ENERGY EFFICIENCY AND REDUCE FUEL CONSUMPTION OF COMMUNAL VEHICLES

    Directory of Open Access Journals (Sweden)

    Nebojša M Jovičić

    2010-01-01

    Full Text Available Collection and transportation within the system of solid waste management may account more than 60% of the overall budget, most of which is for fuel costs. Furthermore, municipal vehicles have great environmental impact through exhaust gases emissions. The aim of this research was to estimate the potential for reduction of fuel consumption and thus the emission of CO2 through the communal vehicles route optimization. General methodology for route optimization is also presented. For the area under study, detailed field experimental research in the City of Kragujevac was conducted. Using GIS and GPS technology, whole municipally infrastructure for waste collection was scanned and all paths of communal tracks was recorded and allocated in developed database. Based on experimental and numerical results, one typical municipal vehicle route was analyzed by using ArcGis software. The obtained result indicates 2700 km of possible savings per year concerning one communal vehicle. In addition, the most fuel-economical route was extracted and compared with the original route, and with the routes extracted from criterions concerning the traffic time and shortest distance. According to available information for the City of Kragujevac and the results from this study, it was estimated that the total savings could be 20% in costs and the associated emissions.

  2. Route Assessment for Unmanned Aerial Vehicle Based on Cloud Model

    Directory of Open Access Journals (Sweden)

    Xixia Sun

    2014-01-01

    Full Text Available An integrated route assessment approach based on cloud model is proposed in this paper, where various sources of uncertainties are well kept and modeled by cloud theory. Firstly, a systemic criteria framework incorporating models for scoring subcriteria is developed. Then, the cloud model is introduced to represent linguistic variables, and survivability probability histogram of each route is converted into normal clouds by cloud transformation, enabling both randomness and fuzziness in the assessment environment to be managed simultaneously. Finally, a new way to measure the similarity between two normal clouds satisfying reflexivity, symmetry, transitivity, and overlapping is proposed. Experimental results demonstrate that the proposed route assessment approach outperforms fuzzy logic based assessment approach with regard to feasibility, reliability, and consistency with human thinking.

  3. Research on multi-objective emergency logistics vehicle routing problem under constraint conditions

    Directory of Open Access Journals (Sweden)

    Miaomiao Du

    2013-03-01

    Full Text Available Purpose: Aim at choosing a relative good vehicle routing in emergency conditions under constraint conditions when disaster happens. Rapid response and rescue can save a lot of people. Design/methodology/approach: Modeling analysis: establishing a mathematical model of multi-objective emergency logistics vehicle routing problem. And in end of the paper, we intend to use genetic algorithms to solve the problem. Findings: Considering time requirement and cost limit both while choosing vehicle routing when the disasters happens is meaningful. We can get a relative good result and give a guidance to rescue teams. Originality/value: Consider cost and time objectives and kinds of realistic conditions (such as the road congestion in the model when solving the problem, having expanded the theory scope.

  4. A Method of Vehicle Route Prediction Based on Social Network Analysis

    Directory of Open Access Journals (Sweden)

    Ning Ye

    2015-01-01

    Full Text Available A method of vehicle route prediction based on social network analysis is proposed in this paper. The difference from proposed work is that, according to our collected vehicles’ past trips, we build a relationship model between different road segments rather than find the driving regularity of vehicles to predict upcoming routes. In this paper, firstly we depend on graph theory to build an initial road network model and modify related model parameters based on the collected data set. Then we transform the model into a matrix. Secondly, two concepts from social network analysis are introduced to describe the meaning of the matrix and we process it by current software of social network analysis. Thirdly, we design the algorithm of vehicle route prediction based on the above processing results. Finally, we use the leave-one-out approach to verify the efficiency of our algorithm.

  5. Enhancing Solution Similarity in Multi-Objective Vehicle Routing Problems with Different Demand Periods

    OpenAIRE

    Murata, Tadahiko; Itai, Ryota

    2008-01-01

    In this chapter, we proposed a local search that can be used in a two-fold EMO algorithm for multiple-objective VRPs with different demands. The simulation results show that the proposed method have the fine effectiveness to enhance the similarity of obtained routes for vehicles. Although the local search slightly deteriorates the maximum duration, it improves the similarity of the routes that may decrease the possibility of getting lost the way of drivers. If drivers get lost their ways duri...

  6. Optimized Crossover Genetic Algorithm for Vehicle Routing Problem with Time Windows

    Directory of Open Access Journals (Sweden)

    H. Nazif

    2010-01-01

    Full Text Available Problem statement: In this study, we considered the application of a genetic algorithm to vehicle routing problem with time windows where a set of vehicles with limits on capacity and travel time are available to service a set of customers with demands and earliest and latest time for serving. The objective is to find routes for the vehicles to service all the customers at a minimal cost without violating the capacity and travel time constraints of the vehicles and the time window constraints set by the customers. Approach: We proposed a genetic algorithm using an optimized crossover operator designed by a complete undirected bipartite graph that finds an optimal set of delivery routes satisfying the requirements and giving minimal total cost. Various techniques have also been introduced into the proposed algorithm to further enhance the solutions quality. Results: We tested our algorithm with benchmark instances and compared it with some other heuristics in the literature. The results showed that the proposed algorithm is competitive in terms of the quality of the solutions found. Conclusion/Recommendations: This study presented a genetic algorithm for solving vehicle routing problem with time windows using an optimized crossover operator. From the results, it can be concluded that the proposed algorithm is competitive when compared with other heuristics in the literature.

  7. Single-Commodity Vehicle Routing Problem with Pickup and Delivery Service

    Directory of Open Access Journals (Sweden)

    Goran Martinovic

    2008-01-01

    Full Text Available We present a novel variation of the vehicle routing problem (VRP. Single commodity cargo with pickup and delivery service is considered. Customers are labeled as either cargo sink or cargo source, depending on their pickup or delivery demand. This problem is called a single commodity vehicle routing problem with pickup and delivery service (1-VRPPD. 1-VRPPD deals with multiple vehicles and is the same as the single-commodity traveling salesman problem (1-PDTSP when the number of vehicles is equal to 1. Since 1-VRPPD specializes VRP, it is hard in the strong sense. Iterative modified simulated annealing (IMSA is presented along with greedy random-based initial solution algorithm. IMSA provides a good approximation to the global optimum in a large search space. Experiment is done for the instances with different number of customers and their demands. With respect to average values of IMSA execution times, proposed method is appropriate for practical applications.

  8. A new memetic algorithm for solving split delivery vehicle routing problem

    Directory of Open Access Journals (Sweden)

    Ali Bozorgi-Amiri

    2015-11-01

    Full Text Available Split delivery vehicle routing problem is one of the traditional types of routing problems in which the demand of different points can be divided among vehicles and the objective is to minimize the path length, which vehicles travel. In this paper, fuel cost of vehicles which is assumed to be dependent on their traveled path and load is considered as the objective functions. Namely, the cost of the consumed fuel is proportionate to the unit of load carried per unit of distance. In order to solve the proposed model a new memetic algorithm is developed which has two rows. The performance of the proposed algorithm for 21 standard problems is compared with the optimum solutions obtained from mathematical programming standard solver and the solutions of the same algorithm with single row solution representation. The results express the efficiency of developed algorithm.

  9. Multidimentional Self-organization for Online Time-Constrained Vehicle Routing Problems

    OpenAIRE

    ZEDDINI, B; ZARGAYOUNA, M

    2010-01-01

    Vehicle Routing problems are highly complex problems for which different Artificial Intelligence techniques have been used. In this paper, we propose two agent-oriented self-organization models for the dynamic version of the problem with time windows. The first model relies on a spatial representation, and the second is based on a space-time representation of the agents' action zones, which are able to maintain a good distribution of the vehicles on the environment. This distribution provides...

  10. Opportunity costs calculation in agent-based vehicle routing and scheduling

    OpenAIRE

    Mes, Martijn; Heijden, van der, C.A.M.; Schuur, Peter

    2006-01-01

    In this paper we consider a real-time, dynamic pickup and delivery problem with timewindows where orders should be assigned to one of a set of competing transportation companies. Our approach decomposes the problem into a multi-agent structure where vehicle agents are responsible for the routing and scheduling decisions and the assignment of orders to vehicles is done by using a second-price auction. Therefore the system performance will be heavily dependent on the pricing strategy of the veh...

  11. Modelling of the optimal vehicle route in terrain in emergency situations using GIS data

    Science.gov (United States)

    Rybansky, M.

    2014-02-01

    Most navigation systems in transport are oriented towards the search for optimal paths (shortest or fastest), using vector GIS data. At the time of natural disasters and emergency situations is necessary to consider roads and terrain for transport. This article is focused on finding optimal routes in terrain, which contains a number of point, line and area obstacles. The most frequent point obstacles are trees in the forest. The paper analyzes the typical structure of tree stands in the forest, their characteristics in GIS databases, as well as dimensional parameters of vehicles moving in the forest. The quality of these data is a prerequisite for finding routes between point obstacles. Searching for the fastest or shortest route of the vehicle described in this article is based on the use of the relationship between the Delaunay triangulation and Voronoi graph, the application of Dijkstra's algorithm and the optimization of fractional line. The above-mentioned methods are also exploitable for searching for the shortest route of movement among line obstructions and area obstructions, such route can be apprehended as the joining of points defining impassable terrain. In such a case, the condition must be met that the distance of terminal points of joins has to be adjusted to the extent that it will be shorter than a vehicle width increased by safe margin.

  12. Modelling of the optimal vehicle route in terrain in emergency situations using GIS data

    International Nuclear Information System (INIS)

    Most navigation systems in transport are oriented towards the search for optimal paths (shortest or fastest), using vector GIS data. At the time of natural disasters and emergency situations is necessary to consider roads and terrain for transport. This article is focused on finding optimal routes in terrain, which contains a number of point, line and area obstacles. The most frequent point obstacles are trees in the forest. The paper analyzes the typical structure of tree stands in the forest, their characteristics in GIS databases, as well as dimensional parameters of vehicles moving in the forest. The quality of these data is a prerequisite for finding routes between point obstacles. Searching for the fastest or shortest route of the vehicle described in this article is based on the use of the relationship between the Delaunay triangulation and Voronoi graph, the application of Dijkstra's algorithm and the optimization of fractional line. The above-mentioned methods are also exploitable for searching for the shortest route of movement among line obstructions and area obstructions, such route can be apprehended as the joining of points defining impassable terrain. In such a case, the condition must be met that the distance of terminal points of joins has to be adjusted to the extent that it will be shorter than a vehicle width increased by safe margin

  13. Vehicle routing for the eco-efficient collection of household plastic waste.

    Science.gov (United States)

    Bing, Xiaoyun; de Keizer, Marlies; Bloemhof-Ruwaard, Jacqueline M; van der Vorst, Jack G A J

    2014-04-01

    Plastic waste is a special category of municipal solid waste. Plastic waste collection is featured with various alternatives of collection methods (curbside/drop-off) and separation methods (source-/post-separation). In the Netherlands, the collection routes of plastic waste are the same as those of other waste, although plastic is different than other waste in terms of volume to weight ratio. This paper aims for redesigning the collection routes and compares the collection options of plastic waste using eco-efficiency as performance indicator. Eco-efficiency concerns the trade-off between environmental impacts, social issues and costs. The collection problem is modeled as a vehicle routing problem. A tabu search heuristic is used to improve the routes. Collection alternatives are compared by a scenario study approach. Real distances between locations are calculated with MapPoint. The scenario study is conducted based on real case data of the Dutch municipality Wageningen. Scenarios are designed according to the collection alternatives with different assumptions in collection method, vehicle type, collection frequency and collection points, etc. Results show that the current collection routes can be improved in terms of eco-efficiency performance by using our method. The source-separation drop-off collection scenario has the best performance for plastic collection assuming householders take the waste to the drop-off points in a sustainable manner. The model also shows to be an efficient decision support tool to investigate the impacts of future changes such as alternative vehicle type and different response rates.

  14. Refinements of the column generation process for the Vehicle Routing Problem with Time Windows

    DEFF Research Database (Denmark)

    Larsen, Jesper

    2004-01-01

    interval denoted the time window. The objective is to determine routes for the vehicles that minimizes the accumulated cost (or distance) with respect to the above mentioned constraints. Currently the best approaches for determining optimal solutions are based on column generation and Branch...

  15. Subset-row inequalities applied to the vehicle routing problem with time windows

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Petersen, Bjørn; Spoorendonk, Simon;

    2008-01-01

    This paper presents a branch-and-cut-and-price algorithm for the vehicle-routing problem with time windows. The standard Dantzig-Wolfe decomposition of the arc flow formulation leads to a set-partitioning problem as the master problem and an elementary shortest-path problem with resource...

  16. Routing of Electric Vehicles: Case Study of City Distribution in Copenhagen

    DEFF Research Database (Denmark)

    Linde, Esben; Larsen, Allan; Nørrelund, Anders Vedsted;

    . References [1] T. van Rooijen and H. Quak, “Local impacts of a new urban consolidation centre – the case of Binnenstadservice.nl,” Procedia - Social and Behavioral Sciences, vol. 2, no. 3, pp. 5967–5979, Jan. 2010. [2] S. Erdogan and E. Miller-Hooks, “A Green Vehicle Routing Problem,” Transportation Research...

  17. Stochastic time-dependent vehicle routing problem: Mathematical models and ant colony algorithm

    Directory of Open Access Journals (Sweden)

    Zhengyu Duan

    2015-11-01

    Full Text Available This article addresses the stochastic time-dependent vehicle routing problem. Two mathematical models named robust optimal schedule time model and minimum expected schedule time model are proposed for stochastic time-dependent vehicle routing problem, which can guarantee delivery within the time windows of customers. The robust optimal schedule time model only requires the variation range of link travel time, which can be conveniently derived from historical traffic data. In addition, the robust optimal schedule time model based on robust optimization method can be converted into a time-dependent vehicle routing problem. Moreover, an ant colony optimization algorithm is designed to solve stochastic time-dependent vehicle routing problem. As the improvements in initial solution and transition probability, ant colony optimization algorithm has a good performance in convergence. Through computational instances and Monte Carlo simulation tests, robust optimal schedule time model is proved to be better than minimum expected schedule time model in computational efficiency and coping with the travel time fluctuations. Therefore, robust optimal schedule time model is applicable in real road network.

  18. Intention-Aware Routing to Minimise Delays at Electric Vehicle Charging Stations

    NARCIS (Netherlands)

    De Weerdt, M.M.; Gerding, E.H.; Stein, S.; Robu, V.; Jennings, N.R.

    2013-01-01

    En-route charging stations allow electric vehicles to greatly extend their range. However, as a full charge takes a considerable amount of time, there may be significant waiting times at peak hours. To address this problem, we propose a novel navigation system, which communicates its intentions (i.

  19. Opportunity costs calculation in agent-based vehicle routing and scheduling

    NARCIS (Netherlands)

    Mes, Martijn; Heijden, van der Matthieu; Schuur, Peter

    2006-01-01

    In this paper we consider a real-time, dynamic pickup and delivery problem with timewindows where orders should be assigned to one of a set of competing transportation companies. Our approach decomposes the problem into a multi-agent structure where vehicle agents are responsible for the routing and

  20. Relative Performance of Certain Meta Heuristics on Vehicle Routing Problem with Time Windows

    Directory of Open Access Journals (Sweden)

    Sandhya

    2015-11-01

    Full Text Available —Solving Vehicle Routing Problem (VRP and its variants arise in many real life distribution systems. Classical VRP can be described as the problem of finding minimum cost routes with identical vehicles having fixed capacity which starts from a depot and reaches a number of customers with known demands with the proviso that each route starts and ends at the depot and the demand of each customer does not exceed the vehicle capacity is met. One of the generalizations of standard VRP is Vehicle Routing Problem with Time Windows (VRPTW with added complexity of serving every customer within a specified time window. Since VRPTW is a NP hard meta heuristics have often been designed for solving it. In this paper we compare the performance of Simulated Annealing (SA, genetic Algorithm (GA and Ant Colony Optimization (ACO for solving VRPTW based on their performance using different parameters taking total travel distance as the objective to be minimized. The results indicate that ACO is in general slightly more efficient then SA and GA.

  1. An Adaptable Variable Neighborhood Search for the Vehicle Routing Problem with Order Outsourcing

    NARCIS (Netherlands)

    Huijink, S.; Kant, G.; Peeters, M.J.P.

    2014-01-01

    In practice, many package transportation companies lower their costs by hiring outside carriers to serve orders that cannot be served efficiently by their own trucks. The problem which takes the order outsource option into account is the Vehicle Routing Problem with Private Fleet and Common Carrier.

  2. The time-dependent two-echelon capacitated vehicle routing problem with environmental considerations

    NARCIS (Netherlands)

    Soysal, M.; Bloemhof, J.M.; Bektas, T.

    2015-01-01

    Multi-echelon distribution strategies in which freight is delivered to customers via intermediate depots rather than direct shipments is an increasingly popular strategy in urban logistics. This is primarily to alleviate the environmental (e.g., energy usage and congestion) and social (e.g., traffic

  3. Models and Methods for the City Logistics: The Two-Echelon Capacitated Vehicle Routing Problem

    OpenAIRE

    Gonzalez-Feliu, Jesus

    2008-01-01

    La distribution de marchandises est un secteur en constant développement et constitue un facteur économique important. Par contre, dans les villes, il contribue notamment aux problèmes de congestion, pollution, bruit et d'autres dérangements à la population des villes. Pour faire face à ces problèmes, une nouvelle discipline est née à la fin du XXe siècle, la " City Logistics ", qui a comme objectifs principaux la réduction de la congestion, la pollution et le bruit occasionné par le transpor...

  4. Intelligent Iterated Local Search Methods for Solving Vehicle Routing Problem with Different Fleets

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To solve vehicle routing problem with different fleets, two methodologies are developed. The first methodology adopts twophase strategy. In the first phase, the improved savings method is used to assign customers to appropriate vehicles. In the second phase, the iterated dynasearch algorithm is adopted to route each selected vehicle with the assigned customers. The iterated dynasearch algorithm combines dynasearch algorithm with iterated local search algorithm based on random kicks. The second methodplogy adopts the idea of cyclic transfer which is performed by using dynamic programming algorithm, and the iterated dynasearch algorithm is also embedded in it. The test results show that both methodologies generate better solutions than the traditional method, and the second methodology is superior to the first one.

  5. Vehicle Routing Problem with Backhaul, Multiple Trips and Time Window

    Directory of Open Access Journals (Sweden)

    Johan Oscar Ong

    2011-01-01

    Full Text Available Transportation planning is one of the important components to increase efficiency and effectiveness in the supply chain system. Good planning will give a saving in total cost of the supply chain. This paper develops the new VRP variants’, VRP with backhauls, multiple trips, and time window (VRPBMTTW along with its problem solving techniques by using Ant Colony Optimization (ACO and Sequential Insertion as initial solution algorithm. ACO is modified by adding the decoding process in order to determine the number of vehicles, total duration time, and range of duration time regardless of checking capacity constraint and time window. This algorithm is tested by using set of random data and verified as well as analyzed its parameter changing’s. The computational results for hypothetical data with 50% backhaul and mix time windows are reported.

  6. On the vehicle routing problem with time windows

    DEFF Research Database (Denmark)

    Kallehauge, Brian

    2006-01-01

    at the master problem level by Lagrangian relaxation. The result is a Lagrangian branch-andcut- and-price (LBCP) algorithm for the VRPTW. Making use of this acceleration strategy at the master problem level gives a significant speed-up compared to algorithms in the literature based on traditional column...... of the constraint set requiring that each customer must be served by exactly one vehicle yielding a constrained shortest path subproblem. We present a stabilized cutting-plane algorithm within the framework of linear programming for solving the associated Lagrangian dual problem. This algorithm creates easier...... generation. We have solved two test problems introduced in 2001 by Gehring and Homberger with 400 and 1000 customers respectively, which to date are the largest problems ever solved to optimality. We have implemented the LBCP algorithm using the ABACUS open-source framework for solving mixed-integer linear...

  7. A lower bound for the node, edge, and arc routing problem

    DEFF Research Database (Denmark)

    Bach, Lukas; Hasle, Geir; Wøhlk, Sanne

    2013-01-01

    The Node, Edge, and Arc Routing Problem (NEARP) was defined by Prins and Bouchenoua in 2004, although similar problems have been studied before. This problem, also called the Mixed Capacitated General Routing Problem (MCGRP), generalizes the classical Capacitated Vehicle Routing Problem (CVRP......), the Capacitated Arc Routing Problem (CARP), and the General Routing Problem. It captures important aspects of real-life routing problems that were not adequately modeled in previous Vehicle Routing Problem (VRP) variants. The authors also proposed a memetic algorithm procedure and defined a set of test instances...... the CBMix benchmark. The first is based on well-known CARP instances; the second consists of real life cases of newspaper delivery routing. We provide numerical results in the form of lower and best known upper bounds for all instances of all three benchmarks. For three of the instances, the gap between...

  8. Spatial, temporal, and hybrid decompositions for large-scale vehicle routing with time windows

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Russell W [Los Alamos National Laboratory

    2010-01-01

    This paper studies the use of decomposition techniques to quickly find high-quality solutions to large-scale vehicle routing problems with time windows. It considers an adaptive decomposition scheme which iteratively decouples a routing problem based on the current solution. Earlier work considered vehicle-based decompositions that partitions the vehicles across the subproblems. The subproblems can then be optimized independently and merged easily. This paper argues that vehicle-based decompositions, although very effective on various problem classes also have limitations. In particular, they do not accommodate temporal decompositions and may produce spatial decompositions that are not focused enough. This paper then proposes customer-based decompositions which generalize vehicle-based decouplings and allows for focused spatial and temporal decompositions. Experimental results on class R2 of the extended Solomon benchmarks demonstrates the benefits of the customer-based adaptive decomposition scheme and its spatial, temporal, and hybrid instantiations. In particular, they show that customer-based decompositions bring significant benefits over large neighborhood search in contrast to vehicle-based decompositions.

  9. A Multi-objective Optimization Model for Planning Unmanned Aerial Vehicle Cruise Route

    Directory of Open Access Journals (Sweden)

    Xiaofeng Liu

    2016-06-01

    Full Text Available The use of unmanned aerial vehicles (UAVs was introduced to monitor a traffic situation and the respective cruise route optimization problem was given. Firstly, a multi-objective optimization model was proposed, which considered two scenarios: the first scenario was that there were enough UAVs to monitor all the targets, while the second scenario was that only some targets could be monitored due to a lack of UAVs. A multi-objective evolutionary algorithm was subsequently proposed to plan the UAV cruise route. Next, a route planning experiment, using the Microdrones md4-1000 UAV, was conducted and a UAV route planning case was studied. The experiment showed that the UAV actual flight route was almost consistent with the planned route. The case study showed that, compared with the initial optimal solutions, the optimal total UAV cruise distance and the number of UAVs used in scenario 1 decreased by 41.65% and 40.00%, respectively. Meanwhile, the total UAV cruise distance and the number of targets monitored in scenario 2 reduced by 15.75% and increased by 27.27%, respectively. In addition, a comparison study with other algorithms was conducted, while the optimization results were also improved. This demonstrated that the proposed UAV cruise route planning model was effective.

  10. A HYBRID GENETIC ALGORITHM IMPLEMENTATION FOR VEHICLE ROUTING PROBLEM WITH TIME WINDOWS

    Directory of Open Access Journals (Sweden)

    Muhammad Faisal Ibrahim

    2016-01-01

    Full Text Available This article is related to approach development in order to determine the most appropriate route for bottled water delivery from warehouse to retail from particular boundaries such as a limit on number of vehicle, vehicle capacity, and time windows to each retail. A mathematical model of VRPTW is adopted to solve the problem. Malang is one of the drinking water production centers in Indonesia, definitely it will be difficult for the company to determine the optimal delivery route with the existing restrictions. In this research hybrid genetic algorithm is use to determine the route shipping companies with the Java programming language. After analyzing the results obtained show that the results of the implementation of hybrid genetic algorithm is better than the company actual route. Moreover, authors also analyze the effect the number of iterations for the computation time, and the influence the number of iterations for the fitness value or violation. This algorithm can be applied for the routing and the result obtained is an optimal solution

  11. An Improved Spatially Aware Routing Algorithm for Mobile Ad Hoc Network in Inter-Vehicle Communication

    Institute of Scientific and Technical Information of China (English)

    HAN Lu; ZHOU Man-li; TIAN Jing; KURT Rothermel

    2004-01-01

    A new algorithm called spatially aware routing algorithm with enhanced learning (SAREL) is proposed to guarantee the rationality of route selecting in inter-vehicle communication scenario. Firstly, the traffic model is discussed and set up by using Poisson distribution. Then we analyze the process of traffic evaluation with enhanced learning, and exploit movement estimation to assist state memorization. The improvement of algorithm is provided at last compared with our previous work. Simulation results show that SAREL algorithm could achieve better performance in packet delivery ratio, especially when network connection ratio is average.

  12. Integrated consensus-based frameworks for unmanned vehicle routing and targeting assignment

    Science.gov (United States)

    Barnawi, Waleed T.

    Unmanned aerial vehicles (UAVs) are increasingly deployed in complex and dynamic environments to perform multiple tasks cooperatively with other UAVs that contribute to overarching mission effectiveness. Studies by the Department of Defense (DoD) indicate future operations may include anti-access/area-denial (A2AD) environments which limit human teleoperator decision-making and control. This research addresses the problem of decentralized vehicle re-routing and task reassignments through consensus-based UAV decision-making. An Integrated Consensus-Based Framework (ICF) is formulated as a solution to the combined single task assignment problem and vehicle routing problem. The multiple assignment and vehicle routing problem is solved with the Integrated Consensus-Based Bundle Framework (ICBF). The frameworks are hierarchically decomposed into two levels. The bottom layer utilizes the renowned Dijkstra's Algorithm. The top layer addresses task assignment with two methods. The single assignment approach is called the Caravan Auction Algorithm (CarA) Algorithm. This technique extends the Consensus-Based Auction Algorithm (CBAA) to provide awareness for task completion by agents and adopt abandoned tasks. The multiple assignment approach called the Caravan Auction Bundle Algorithm (CarAB) extends the Consensus-Based Bundle Algorithm (CBBA) by providing awareness for lost resources, prioritizing remaining tasks, and adopting abandoned tasks. Research questions are investigated regarding the novelty and performance of the proposed frameworks. Conclusions regarding the research questions will be provided through hypothesis testing. Monte Carlo simulations will provide evidence to support conclusions regarding the research hypotheses for the proposed frameworks. The approach provided in this research addresses current and future military operations for unmanned aerial vehicles. However, the general framework implied by the proposed research is adaptable to any unmanned

  13. The vehicle routing game: An application of cost allocation in a gas and oil company

    Energy Technology Data Exchange (ETDEWEB)

    Engevall, Stefan; Goethe-Lundgren, Maud; Vaerbrand, Peter

    2000-12-01

    In this article we study a cost allocation problem that arises in a distribution planning situation at the Logistics department at Norsk Hydro Olje AB. The routes from one depot during one day are considered, for which the total distribution cost is to be divided among the customers that are visited. This cost allocation problem is formulated as a vehicle routing game, allowing the use of vehicles with different capacities. Cost allocation methods based on different concepts from cooperative game theory, such as the core and the nucleolus, are discussed. A procedure that can be used to investigate whether the core is empty or not is presented, as well as a procedure to compute the nucleolus. Computational results for the Norsk Hydro case are also presented and discussed.

  14. A framework for the interactive resolution of multi-objective vehicle routing problems

    CERN Document Server

    Geiger, Martin Josef

    2008-01-01

    The article presents a framework for the resolution of rich vehicle routing problems which are difficult to address with standard optimization techniques. We use local search on the basis on variable neighborhood search for the construction of the solutions, but embed the techniques in a flexible framework that allows the consideration of complex side constraints of the problem such as time windows, multiple depots, heterogeneous fleets, and, in particular, multiple optimization criteria. In order to identify a compromise alternative that meets the requirements of the decision maker, an interactive procedure is integrated in the resolution of the problem, allowing the modification of the preference information articulated by the decision maker. The framework is prototypically implemented in a computer system. First results of test runs on multiple depot vehicle routing problems with time windows are reported.

  15. A Hybrid Genetic Algorithm for Vehicle Routing Problem with Complex Constraints

    Institute of Scientific and Technical Information of China (English)

    CHEN Yan; LU Jun; LI Zeng-zhi

    2006-01-01

    Most research on the Vehicle Routing Problem (VRP) is focused on standard conditions, which is not suitable for specific cases. A Hybrid Genetic Algorithm is proposed to solve a Vehicle Routing Problem (VRP) with complex side constraints. A novel coding method is designed especially for side constraints. A greedy algorithm combined with a random algorithm is introduced to enable the diversity of the initial population, as well as a local optimization algorithm employed to improve the searching efficiency. In order to evaluate the performance, this mechanism has been implemented in an oil distribution center, the experimental and executing results show that the near global optimal solution can be easily and quickly obtained by this method, and the solution is definitely satisfactory in the VRP application.

  16. Field Operations Program - U.S. Postal Service - Fountain Valley Electric Carrier Route Vehicle Testing; TOPICAL

    International Nuclear Information System (INIS)

    The United States Postal Service (USPS) has ordered 500 light-duty electric carrier route vehicles (ECRV) mostly for their delivery carriers to use in several California locations. The 500 ECRVs have been defined as a demonstration fleet to support a decision of potentially ordering 5,500 additional ECRVs. Several different test methods are being used by the USPS to evaluate the 500-vehicle deployment. One of these test methods is the ECRV Customer Acceptance Test Program at Fountain Valley, California. Two newly manufactured ECRVs were delivered to the Fountain Valley Post Office and eighteen mail carriers primarily drove the ECRVs on ''park and loop'' mail delivery routes for a period of 2 days each. This ECRV testing consisted of 36 route tests, 18 tests per vehicle. The 18 mail carriers testing the ECRVs were surveyed for the opinions on the performance of the ECRVs. The U.S. Department of Energy, through its Field Operations Program, is supporting the USPS's ECRV testing activities both financially and with technical expertise. As part of this support, Field Operations Program personnel at the Idaho National Engineering and Environmental Laboratory have compiled this report based on the data generated by the USPS and its testing contractor (Ryerson, Master and Associates, Inc.) During the 36 route tests, the two test vehicles were driven a total of 474 miles, averaging 13 mile per test. The distance of the 36 route tests ranged from 4 to 34 miles. Both miles driven and State-of-Charge (SOC) data was collected for only 28 of the route tests. During these 28 tests, the ECRVs were driven a total of 447 miles. The SOC used during the 28 tests averaged a 41% decrease and the average distance driven was 16 miles. This suggests that a 16-mile route uses almost half of the ECRV's battery energy. The 18 carriers also rated 12 ECRV traits that included the physical design of the ECRVs as well as their performance. Based on a scale of 1 being the lowest and 5 being

  17. An apprenticeship learning hyper-heuristic for vehicle routing in HyFlex

    OpenAIRE

    Asta, Shahriar; Özcan, Ender

    2014-01-01

    Apprenticeship learning occurs via observations while an expert is in action. A hyper-heuristic is a search method or a learning mechanism that controls a set of low level heuristics or combines different heuristic components to generate heuristics for solving a given computationally hard problem. In this study, we investigate into a novel apprenticeship-learning-based approach which is used to automatically generate a hyper-heuristic for vehicle routing. This approach itself can be considere...

  18. A Hybrid Chaos-Particle Swarm Optimization Algorithm for the Vehicle Routing Problem with Time Window

    Directory of Open Access Journals (Sweden)

    Qi Hu

    2013-04-01

    Full Text Available State-of-the-art heuristic algorithms to solve the vehicle routing problem with time windows (VRPTW usually present slow speeds during the early iterations and easily fall into local optimal solutions. Focusing on solving the above problems, this paper analyzes the particle encoding and decoding strategy of the particle swarm optimization algorithm, the construction of the vehicle route and the judgment of the local optimal solution. Based on these, a hybrid chaos-particle swarm optimization algorithm (HPSO is proposed to solve VRPTW. The chaos algorithm is employed to re-initialize the particle swarm. An efficient insertion heuristic algorithm is also proposed to build the valid vehicle route in the particle decoding process. A particle swarm premature convergence judgment mechanism is formulated and combined with the chaos algorithm and Gaussian mutation into HPSO when the particle swarm falls into the local convergence. Extensive experiments are carried out to test the parameter settings in the insertion heuristic algorithm and to evaluate that they are corresponding to the data’s real-distribution in the concrete problem. It is also revealed that the HPSO achieves a better performance than the other state-of-the-art algorithms on solving VRPTW.

  19. GREEDY NON-DOMINATED SORTING IN GENETIC ALGORITHM-II FOR VEHICLE ROUTING PROBLEM IN DISTRIBUTION

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Vehicle routing problem in distribution (VRPD) is a widely used type of vehicle routing problem (VRP), which has been proved as NP-Hard, and it is usually modeled as single objective optimization problem when modeling. For multi-objective optimization model, most researches consider two objectives. A multi-objective mathematical model for VRP is proposed, which considers the number of vehicles used, the length of route and the time arrived at each client. Genetic algorithm is one of the most widely used algorithms to solve VRP. As a type of genetic algorithm (GA), non-dominated sorting in genetic algorithm-Ⅱ(NSGA-Ⅱ) also suffers from premature convergence and enclosure competition. In order to avoid these kinds of shortage, a greedy NSGA-Ⅱ (GNSGA-Ⅱ) is proposed for VRP problem. Greedy algorithm is implemented in generating the initial population, cross-over and mutation. All these procedures ensure that NSGA-Ⅱ is prevented from premature convergence and refine the performance of NSGA-Ⅱ at each step. In the distribution problem of a distribution center in Michigan, US, the GNSGA-Ⅱ is compared with NSGA-Ⅱ. As a result, the GNSGA-II is the most efficient one and can get the most optimized solution to VRP problem. Also, in GNSGA-II, premature convergence is better avoided and search efficiency has been improved sharply.

  20. Effects of Vehicle Number Feedback in Multi-Route Intelligent Traffic Systems

    Science.gov (United States)

    Dong, Chuanfei; Ma, Xu; Wang, Binghong

    We first study dynamics of traffic flow with real-time information and the influence of a new feedback strategy named Vehicle Number Feedback Strategy (VNFS) in a multi-route scenario in which dynamic information can be generated and displayed on the board (the board refers to a variable message sign where information on the routes is displayed) to guide road users to make a choice. In a multi-route scenario, our model incorporates the effects of adaptability into the cellular automaton models of traffic flow and simulation results adopting vehicle number feedback strategy have demonstrated high efficiency in controlling spatial distribution of traffic patterns compared with the other three information feedback strategies, i.e. Travel Time Feedback Strategy (TTFS), Mean Velocity Feedback Strategy (MVFS) and Congestion Coefficient Feedback Strategy (CCFS). We also discuss the influence of expected arrival rate (Vp) at the entrance on the average flux of each route, and we find that the flux adopting VNFS is always the largest at each Vp value among these four feedback strategies.

  1. A memory structure adapted simulated annealing algorithm for a green vehicle routing problem.

    Science.gov (United States)

    Küçükoğlu, İlker; Ene, Seval; Aksoy, Aslı; Öztürk, Nursel

    2015-03-01

    Currently, reduction of carbon dioxide (CO2) emissions and fuel consumption has become a critical environmental problem and has attracted the attention of both academia and the industrial sector. Government regulations and customer demands are making environmental responsibility an increasingly important factor in overall supply chain operations. Within these operations, transportation has the most hazardous effects on the environment, i.e., CO2 emissions, fuel consumption, noise and toxic effects on the ecosystem. This study aims to construct vehicle routes with time windows that minimize the total fuel consumption and CO2 emissions. The green vehicle routing problem with time windows (G-VRPTW) is formulated using a mixed integer linear programming model. A memory structure adapted simulated annealing (MSA-SA) meta-heuristic algorithm is constructed due to the high complexity of the proposed problem and long solution times for practical applications. The proposed models are integrated with a fuel consumption and CO2 emissions calculation algorithm that considers the vehicle technical specifications, vehicle load, and transportation distance in a green supply chain environment. The proposed models are validated using well-known instances with different numbers of customers. The computational results indicate that the MSA-SA heuristic is capable of obtaining good G-VRPTW solutions within a reasonable amount of time by providing reductions in fuel consumption and CO2 emissions. PMID:25056743

  2. Improved Multi-Agent System for the Vehicle Routing Problem with Time Windows

    Institute of Scientific and Technical Information of China (English)

    DAN Zhenggang; CAI Linning; ZHENG Li

    2009-01-01

    The vehicle routing problem with time windows (VRPTW) involves assigning a fleet of limited ca-pacity vehicles to serve a set of customers without violating the capacity and time constraints. This paper presents a multi-agent model system for the VRPTW based on the internal behavior of agents and coordina-tion among the agents. The system presents a formal view of coordination using the traditional contract-net protocol (CNP) that relies on the basic loop of agent behavior for order receiving, order announcement, bid calculation, and order scheduling followed by order execution. An improved CNP method based on a vehicle selection strategy is used to reduce the number of negotiations and the negotiation time. The model is vali-dated using Solomon's benchmarks, with the results showing that the improved CNP uses only 30% as many negotiations and only 70% of the negotiation time of the traditional CNP.

  3. Simultaneous Vehicle and Crew Routing and Scheduling for Partial- and Full-Load Long-Distance Road Transport

    OpenAIRE

    Michael Drexl; Julia Rieck; Thomas Sigl; Bettina Press

    2013-01-01

    This paper studies a simultaneous vehicle and crew routing and scheduling problem arising in long-distance road transport in Europe: Pickup-and-delivery requests have to be fulfilled over a multi-period planning horizon by a heterogeneous fleet of trucks and drivers. Typically, in the vehicle routing literature, a fixed assignment of a driver to a truck is assumed. In our approach, we abandon this assumption and allow truck/driver changes at geographically dispersed relay stations. This offer...

  4. Modeling municipal solid waste collection: A generalized vehicle routing model with multiple transfer stations, gather sites and inhomogeneous vehicles in time windows.

    Science.gov (United States)

    Son, Le Hoang; Louati, Amal

    2016-06-01

    Municipal Solid Waste (MSW) collection is a necessary process in any municipality resulting in the quality-of-life, economic aspects and urban structuralization. The intrinsic nature of MSW collection relates to the development of effective vehicle routing models that optimize the total traveling distances of vehicles, the environmental emission and the investment costs. In this article, we propose a generalized vehicle routing model including multiple transfer stations, gather sites and inhomogeneous vehicles in time windows for MSW collection. It takes into account traveling in one-way routes, the number of vehicles per m(2) and waiting time at traffic stops for reduction of operational time. The proposed model could be used for scenarios having similar node structures and vehicles' characteristics. A case study at Danang city, Vietnam is given to illustrate the applicability of this model. The experimental results have clearly shown that the new model reduces both total traveling distances and operational hours of vehicles in comparison with those of practical scenarios. Optimal routes of vehicles on streets and markets at Danang are given. Those results are significant to practitioners and local policy makers.

  5. Modeling municipal solid waste collection: A generalized vehicle routing model with multiple transfer stations, gather sites and inhomogeneous vehicles in time windows.

    Science.gov (United States)

    Son, Le Hoang; Louati, Amal

    2016-06-01

    Municipal Solid Waste (MSW) collection is a necessary process in any municipality resulting in the quality-of-life, economic aspects and urban structuralization. The intrinsic nature of MSW collection relates to the development of effective vehicle routing models that optimize the total traveling distances of vehicles, the environmental emission and the investment costs. In this article, we propose a generalized vehicle routing model including multiple transfer stations, gather sites and inhomogeneous vehicles in time windows for MSW collection. It takes into account traveling in one-way routes, the number of vehicles per m(2) and waiting time at traffic stops for reduction of operational time. The proposed model could be used for scenarios having similar node structures and vehicles' characteristics. A case study at Danang city, Vietnam is given to illustrate the applicability of this model. The experimental results have clearly shown that the new model reduces both total traveling distances and operational hours of vehicles in comparison with those of practical scenarios. Optimal routes of vehicles on streets and markets at Danang are given. Those results are significant to practitioners and local policy makers. PMID:27036996

  6. A two-stage heuristic method for vehicle routing problem with split deliveries and pickups

    Institute of Scientific and Technical Information of China (English)

    Yong WANG; Xiao-lei MA; Yun-teng LAO; Hai-yan YU; Yong LIU

    2014-01-01

    The vehicle routing problem (VRP) is a well-known combinatorial optimization issue in transportation and logistics network systems. There exist several limitations associated with the traditional VRP. Releasing the restricted conditions of traditional VRP has become a research focus in the past few decades. The vehicle routing problem with split deliveries and pickups (VRPSPDP) is particularly proposed to release the constraints on the visiting times per customer and vehicle capacity, that is, to allow the deliveries and pickups for each customer to be simultaneously split more than once. Few studies have focused on the VRPSPDP problem. In this paper we propose a two-stage heuristic method integrating the initial heuristic algorithm and hybrid heuristic algorithm to study the VRPSPDP problem. To validate the proposed algorithm, Solomon benchmark datasets and extended Solomon benchmark datasets were modified to compare with three other popular algorithms. A total of 18 datasets were used to evaluate the effectiveness of the proposed method. The computational results indicated that the proposed algorithm is superior to these three algorithms for VRPSPDP in terms of total travel cost and average loading rate.

  7. Vehicle Routing Problem for Fashion Supply Chains with Cross-Docking

    Directory of Open Access Journals (Sweden)

    Zhi-Hua Hu

    2013-01-01

    Full Text Available Cross-docking, as a strategy to reduce lead time and enhance the efficiency of the fashion supply chain, has attracted substantial attention from both the academy and the industry. Cross-docking is a critical part of many fashion and textiles supply chains in practice because it can help to achieve many supply chain strategies such as postponement. We consider a model where there are multiple suppliers and customers in a single cross-docking center. With such a model setting, the issue concerning the coordinated routing between the inbound and outbound routes is much more complex than many traditional vehicle routing problems (VRPs. We formulate the optimal route selection problems from the suppliers to the cross-docking center and from the cross-docking center to the customers as the respective VRPs. Based on the relationships between the suppliers and the customers, we integrate the two VRP models to optimize the overall traveling time, distance, and waiting time at the cross-docking center. In addition, we propose a novel mixed 0/1 integer linear programming model by which the complexity of the problem can be reduced significantly. As demonstrated by the simulation analysis, our proposed model can be solved very efficiently by a commonly used optimization software package.

  8. Minimizing the Carbon Footprint for the Time-Dependent Heterogeneous-Fleet Vehicle Routing Problem with Alternative Paths

    Directory of Open Access Journals (Sweden)

    Wan-Yu Liu

    2014-07-01

    Full Text Available Torespondto the reduction of greenhouse gas emissions and global warming, this paper investigates the minimal-carbon-footprint time-dependent heterogeneous-fleet vehicle routing problem with alternative paths (MTHVRPP. This finds a route with the smallestcarbon footprint, instead of the shortestroute distance, which is the conventional approach, to serve a number of customers with a heterogeneous fleet of vehicles in cases wherethere may not be only one path between each pair of customers, and the vehicle speed differs at different times of the day. Inheriting from the NP-hardness of the vehicle routing problem, the MTHVRPP is also NP-hard. This paper further proposes a genetic algorithm (GA to solve this problem. The solution representedbyour GA determines the customer serving ordering of each vehicle type. Then, the capacity check is used to classify multiple routes of each vehicle type, and the path selection determines the detailed paths of each route. Additionally, this paper improves the energy consumption model used for calculating the carbon footprint amount more precisely. Compared with the results without alternative paths, our experimental results show that the alternative path in this experimenthas a significant impact on the experimental results in terms of carbon footprint.

  9. A P-Based Hybrid Evolutionary Algorithm for Vehicle Routing Problem with Time Windows

    Directory of Open Access Journals (Sweden)

    Yunyun Niu

    2014-01-01

    Full Text Available The ability to solve optimization problems using membrane algorithms is an important application of membrane computing. This work combines membrane systems and genetic operators to build an approximated algorithm for the vehicle routing problem with time windows. The algorithm is based on a tissue-like membrane structure combined with cell separation rules and communication rules; during such processes membranes collect and disperse information. Genetic operators are used as the system's subalgorithms. We also design a special improvement strategy to speed up the search process in subsystems. The experimental results show that the solution quality from the proposed algorithm is competitive with other heuristic or metaheuristic algorithms in the literature.

  10. Clique inequalities applied to the vehicle routing problem with time windows

    DEFF Research Database (Denmark)

    Spoorendonk, Simon; Desaulniers, Guy

    2010-01-01

    This work presents an exact branch-cut-and-price algorithm for the vehicle routing problem with time windows (VRPTW) where the well-known clique inequalities are used as cutting planes defined on the set partitioning master problem variables. It shows how these cutting planes affect the dominance......, to our knowledge, this is a first attempt at incorporating for the VRPTW a set of valid inequalities specialized for the set partitioning polytope. Computational results show that the use of clique inequalities improves the lower bound at the root node of the search tree and reduces the number of...

  11. Branch and price for the time-dependent vehicle routing problem with time windows

    DEFF Research Database (Denmark)

    Dabia, Said; Van Woensel, Tom; De Kok, Ton;

    2013-01-01

    the variant of the TDVRPTW where the objective is to minimize total route duration and denote this variant the duration minimizing TDVRPTW (DM-TDVRPTW). Because of time dependency, vehicles' dispatch times at the depot are crucial as road congestion might be avoided. Because of its complexity, all known...... solution methods to the DM-TDVRPTW are based on (meta-)heuristics. The decomposition of an arc-based formulation leads to a setpartitioning problem as the master problem, and a time-dependent shortest path problem with resource constraints as the pricing problem. The master problem is solved by means...

  12. The Edge Set Cost of the Vehicle Routing Problem with Time Windows

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander; Jepsen, Mads Kehlet; Pisinger, David

    2016-01-01

    We consider an important generalization of the vehicle routing problem with time windows in which a fixed cost must be paid for accessing a set of edges. This fixed cost could reflect payment for toll roads, investment in new facilities, the need for certifications, and other costly investments....... The certifications and investments impose a cost for the company while they also give unlimited usage of a set of roads to all vehicles belonging to the company. This violates the traditional assumption that the path between two destinations is well defined and independent of other choices. Different versions...... for defining the edge sets are discussed and formulated. Both the multigraph case and the direct path case are described, and mixed-integer-programming formulations of the problem are presented for both cases. A solution method based on branch-price-and-cut is applied to the direct path case. The computational...

  13. A Framing Link Based Tabu Search Algorithm for Large-Scale Multidepot Vehicle Routing Problems

    Directory of Open Access Journals (Sweden)

    Xuhao Zhang

    2014-01-01

    Full Text Available A framing link (FL based tabu search algorithm is proposed in this paper for a large-scale multidepot vehicle routing problem (LSMDVRP. Framing links are generated during continuous great optimization of current solutions and then taken as skeletons so as to improve optimal seeking ability, speed up the process of optimization, and obtain better results. Based on the comparison between pre- and postmutation routes in the current solution, different parts are extracted. In the current optimization period, links involved in the optimal solution are regarded as candidates to the FL base. Multiple optimization periods exist in the whole algorithm, and there are several potential FLs in each period. If the update condition is satisfied, the FL base is updated, new FLs are added into the current route, and the next period starts. Through adjusting the borderline of multidepot sharing area with dynamic parameters, the authors define candidate selection principles for three kinds of customer connections, respectively. Link split and the roulette approach are employed to choose FLs. 18 LSMDVRP instances in three groups are studied and new optimal solution values for nine of them are obtained, with higher computation speed and reliability.

  14. Multiobjective Dynamic Vehicle Routing Problem and Time Seed Based Solution Using Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Omprakash Kaiwartya

    2015-01-01

    Full Text Available A multiobjective dynamic vehicle routing problem (M-DVRP has been identified and a time seed based solution using particle swarm optimization (TS-PSO for M-DVRP has been proposed. M-DVRP considers five objectives, namely, geographical ranking of the request, customer ranking, service time, expected reachability time, and satisfaction level of the customers. The multiobjective function of M-DVRP has four components, namely, number of vehicles, expected reachability time, and profit and satisfaction level. Three constraints of the objective function are vehicle, capacity, and reachability. In TS-PSO, first of all, the problem is partitioned into smaller size DVRPs. Secondly, the time horizon of each smaller size DVRP is divided into time seeds and the problem is solved in each time seed using particle swarm optimization. The proposed solution has been simulated in ns-2 considering real road network of New Delhi, India, and results are compared with those obtained from genetic algorithm (GA simulations. The comparison confirms that TS-PSO optimizes the multiobjective function of the identified problem better than what is offered by GA solution.

  15. A multilevel variable neighborhood search heuristic for a practical vehicle routing and driver scheduling problem

    DEFF Research Database (Denmark)

    Wen, Min; Krapper, Emil; Larsen, Jesper;

    2011-01-01

    The world's second largest producer of pork, Danish Crown, also provides a fresh meat supply logistics system within Denmark. This is used by the majority of supermarkets in Denmark. This article addresses an integrated vehicle routing and driver scheduling problem arising at Danish Crown....... The objective is to minimize the total delivery cost that is a weighted sum of two kinds of delivery costs. A multilevel variable neighborhood search heuristic is proposed for the problem. In a preprocessing step, the problem size is reduced through an aggregation procedure. Thereafter, the aggregated weekly...... planning problem is decomposed into daily planning problems, each of which is solved by a variable neighborhood search. Finally, the solution of the aggregated problem is expanded to that of the original problem. The method is implemented and tested on real‐life data consisting of up to 2,000 orders per...

  16. Modified artificial bee colony for the vehicle routing problems with time windows.

    Science.gov (United States)

    Alzaqebah, Malek; Abdullah, Salwani; Jawarneh, Sana

    2016-01-01

    The natural behaviour of the honeybee has attracted the attention of researchers in recent years and several algorithms have been developed that mimic swarm behaviour to solve optimisation problems. This paper introduces an artificial bee colony (ABC) algorithm for the vehicle routing problem with time windows (VRPTW). A Modified ABC algorithm is proposed to improve the solution quality of the original ABC. The high exploration ability of the ABC slows-down its convergence speed, which may due to the mechanism used by scout bees in replacing abandoned (unimproved) solutions with new ones. In the Modified ABC a list of abandoned solutions is used by the scout bees to memorise the abandoned solutions, then the scout bees select a solution from the list based on roulette wheel selection and replace by a new solution with random routs selected from the best solution. The performance of the Modified ABC is evaluated on Solomon benchmark datasets and compared with the original ABC. The computational results demonstrate that the Modified ABC outperforms the original ABC also produce good solutions when compared with the best-known results in the literature. Computational investigations show that the proposed algorithm is a good and promising approach for the VRPTW. PMID:27547672

  17. A self-adaptive memeplexes robust search scheme for solving stochastic demands vehicle routing problem

    Science.gov (United States)

    Chen, Xianshun; Feng, Liang; Ong, Yew Soon

    2012-07-01

    In this article, we proposed a self-adaptive memeplex robust search (SAMRS) for finding robust and reliable solutions that are less sensitive to stochastic behaviours of customer demands and have low probability of route failures, respectively, in vehicle routing problem with stochastic demands (VRPSD). In particular, the contribution of this article is three-fold. First, the proposed SAMRS employs the robust solution search scheme (RS 3) as an approximation of the computationally intensive Monte Carlo simulation, thus reducing the computation cost of fitness evaluation in VRPSD, while directing the search towards robust and reliable solutions. Furthermore, a self-adaptive individual learning based on the conceptual modelling of memeplex is introduced in the SAMRS. Finally, SAMRS incorporates a gene-meme co-evolution model with genetic and memetic representation to effectively manage the search for solutions in VRPSD. Extensive experimental results are then presented for benchmark problems to demonstrate that the proposed SAMRS serves as an efficable means of generating high-quality robust and reliable solutions in VRPSD.

  18. A Memetic Algorithm for the Vehicle Routing Problem with Cross Docking

    Directory of Open Access Journals (Sweden)

    Sanae Larioui

    2015-11-01

    Full Text Available In this paper we address the VRPCD, in which a set of homogeneous vehicles are used to transport products from the suppliers to customers via a cross-dock. The products can be consolidated at the cross-dock but cannot be stored for very long as the cross-dock does not have long-term inventory-holding capabilities. The objective of the VRPCD is to minimize the total traveled distance while respecting time window constraints of suppliers and customers and a time horizon for the whole transportation operation. Rummaging through all the work of literature on vehicle routing problems with cross-docking, there is no work that considers that customer will receive its requests from several suppliers; this will be the point of innovation of this work. A heuristic and a memetic algorithm are used to solve the problem. The proposed algorithms are implemented and tested on data sets involving up to 200 nodes (customers and suppliers. The first results show that the memetic algorithm can produce high quality solutions.

  19. Simultaneous Vehicle and Crew Routing and Scheduling for Partial- and Full-Load Long-Distance Road Transport

    Directory of Open Access Journals (Sweden)

    Michael Drexl

    2013-11-01

    Full Text Available This paper studies a simultaneous vehicle and crew routing and scheduling problem arising in long-distance road transport in Europe: Pickup-and-delivery requests have to be fulfilled over a multi-period planning horizon by a heterogeneous fleet of trucks and drivers. Typically, in the vehicle routing literature, a fixed assignment of a driver to a truck is assumed. In our approach, we abandon this assumption and allow truck/driver changes at geographically dispersed relay stations. This offers greater planning flexibility and allows a better utilization of trucks, but also creates intricate interdependencies between trucks and drivers and requires the synchronization of their routes. A solution heuristic based on a two-stage decomposition of the problem is developed, taking into account European Union social legislation for drivers, and computational experiments using real-world data provided by a major German forwarder are presented and analyzed. The obtained results suggest that for the vehicle and driver cost structure prevalent in Western Europe and for transport requests that are not systematically acquired to complement one another, no cost savings are possible through simultaneous vehicle and crew routing and scheduling, although no formal proof of this fact is possible.

  20. Vehicle Route Replanning for Fruit and Vegetable Delivery%果蔬运输车辆路径再规划

    Institute of Scientific and Technical Information of China (English)

    黄华芳; 王以忠; 李达; 门建婷; 张平; 黄国全

    2012-01-01

    果蔬具有易腐性,在销售、消费时存在很强的时效性,这就要求合理规划果蔬运输车辆的配送路径.在果蔬配送途中,当某运输车遇到特殊情况无法按时送达配送点时,应当对其他运输车进行路径再规划.给出了带时间窗的果蔬运输车辆路径再规划的数学模型,并采用改进蚁群算法进行了求解.仿真试验结果表明,模型及算法可以有效地优化果蔬配送新路线,为降低果蔬腐烂损失、提高销售收入、有效控制运作成本提供了理论支持.%Since fruit and vegetable are highly perishable, and have strong timeliness in selling and consuming, the delivery routes of transport vehicles must be planned reasonably. On the path of fruit and vegetable delivery, a transport vehicle may encounter some unusual circumstances and may not arrive at the next distribution site in time. In this case, the vehicle routes of other transport vehicles should be replanned. A mathematical model for vehicle route replanning with time windows for fruit and vegetable delivery was established, and an improved ant colony algorithm was used to resolve the model. Simulation experiment results showed that the new dispatching routing of fruit and vegetable could be optimized efficiently by using the proposed model and adopted algorithm. This research could provide theoretical support for enterprises which hoped to decrease rot loss of fruit and vegetable, increase sales income and control operating cost effectively.

  1. Design of a High Voltage Bidirectional DC-DC Converter for Driving Capacitive Incremental Actuators usable in Electric Vehicles (EVs)

    OpenAIRE

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.; Maksimovic, Dragan; Sarban, Rahimullah

    2014-01-01

    This paper presents the design of a low input (24 V) and variable high output voltage (0-2.5 kV) bidirectional dc-dc converter for driving a capacitive actuator. The topology is a digitally controlled bidirectional flyback converter with a variable frequency control. The objective is, to design the converter for efficiently charging and discharging the capacitive actuator from 0 V to 2.5 kV and vice versa, respectively. The converter is used to drive a dielectric electro active polymer (DEAP)...

  2. Design of a High Voltage Bidirectional DC-DC Converter for Driving Capacitive Incremental Actuators usable in Electric Vehicles (EVs)

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.;

    2014-01-01

    and medical industries. The design of the bidirectional flyback converter to charge and discharge a 400 nF capacitive actuator is presented, when 4 kV and 4.5 kV high voltage MOSFETs are used on the secondary high voltage side. The experimental results and efficiency measurements of the converter...

  3. Development of a hybrid genetic algorithm based decision support system for vehicle routing and scheduling in supply chain logistics managment

    OpenAIRE

    Khanian, Seyed Mohammad Shafi

    2007-01-01

    Vehicle Routing and Scheduling (VRS) constitute an important part of logistics management. Given the fact that the worldwide cost on physical distribution is evermore increasing, the global competition and the complex nature of logistics problems, one area, which determines the efficiency of all others, is the VRS activities. The application of Decision Support Systems (DSS) to assist logistics management with an efficient VRS could be of great benefit. Although the benefits of DSS in VRS are...

  4. A Two-Phase Heuristic Algorithm for the Common Frequency Routing Problem with Vehicle Type Choice in the Milk Run

    Directory of Open Access Journals (Sweden)

    Yu Lin

    2015-01-01

    Full Text Available High frequency and small lot size are characteristics of milk runs and are often used to implement the just-in-time (JIT strategy in logistical systems. The common frequency problem, which simultaneously involves planning of the route and frequency, has been extensively researched in milk run systems. In addition, vehicle type choice in the milk run system also has a significant influence on the operating cost. Therefore, in this paper, we simultaneously consider vehicle routing planning, frequency planning, and vehicle type choice in order to optimize the sum of the cost of transportation, inventory, and dispatch. To this end, we develop a mathematical model to describe the common frequency problem with vehicle type choice. Since the problem is NP hard, we develop a two-phase heuristic algorithm to solve the model. More specifically, an initial satisfactory solution is first generated through a greedy heuristic algorithm to maximize the ratio of the superior arc frequency to the inferior arc frequency. Following this, a tabu search (TS with limited search scope is used to improve the initial satisfactory solution. Numerical examples with different sizes establish the efficacy of our model and our proposed algorithm.

  5. Digital capacitance measuring system

    Science.gov (United States)

    1973-01-01

    The hardware phase of a digital capacitance measuring system is presented with the major emphasis placed on the electrical design and operation. Test results are included of the three units fabricated. The system's interface is applicable to existing requirements for the space shuttle vehicle.

  6. Wheeled mobility device transportation safety in fixed route and demand-responsive public transit vehicles within the United States.

    Science.gov (United States)

    Frost, Karen L; van Roosmalen, Linda; Bertocci, Gina; Cross, Douglas J

    2012-01-01

    An overview of the current status of wheelchair transportation safety in fixed route and demand-responsive, non-rail, public transportation vehicles within the US is presented. A description of each mode of transportation is provided, followed by a discussion of the primary issues affecting safety, accessibility, and usability. Technologies such as lifts, ramps, securement systems, and occupant restraint systems, along with regulations and voluntary industry standards have been implemented with the intent of improving safety and accessibility for individuals who travel while seated in their wheeled mobility device (e.g., wheelchair or scooter). However, across both fixed route and demand-responsive transit systems a myriad of factors such as nonuse and misuse of safety systems, oversized wheeled mobility devices, vehicle space constraints, and inadequate vehicle operator training may place wheeled mobility device (WhMD) users at risk of injury even under non-impact driving conditions. Since WhMD-related incidents also often occur during the boarding and alighting process, the frequency of these events, along with factors associated with these events are described for each transit mode. Recommendations for improving WhMD transportation are discussed given the current state of PMID:22876731

  7. Technical evaluation of vehicle ignition systems: conduct differences between a high energy capacitive system and a standard inductive system

    Directory of Open Access Journals (Sweden)

    Bruno Santos Goulart

    2014-09-01

    Full Text Available An efficient combustion depends on many factors, such as injection, turbulence and ignition characteristics. With the improvement of internal combustion engines the turbulence intensity and internal pressure have risen, demanding more efficient and powerful ignition systems. In direct injection engines, the stratified charge resultant from the wall/air-guided or spray-guided system requires even more energy. The Paschen’s law shows that spark plug gap and mixture density are proportional to the dielectric rupture voltage. It is known that larger spark gaps promote higher efficiency in the internal combustion engines, since the mixture reaction rate rises proportionally. However, the ignition system must be adequate to the imposed gap, not only on energy, but also on voltage and spark duration. For the reported study in this work two test benches were built: a standard inductive ignition system and a capacitive discharge high energy ignition system, with variable voltage and capacitance. The influence of the important parameters energy and ignition voltage on the spark duration, as well as the electrode gap and shape were analyzed. It was also investigated the utilization of a coil with lower resistance and inductance values, as well as spark plugs with and without internal resistances.

  8. A Novel Discrete Differential Evolution Algorithm for the Vehicle Routing Problem in B2C E-Commerce

    Science.gov (United States)

    Xia, Chao; Sheng, Ying; Jiang, Zhong-Zhong; Tan, Chunqiao; Huang, Min; He, Yuanjian

    2015-12-01

    In this paper, a novel discrete differential evolution (DDE) algorithm is proposed to solve the vehicle routing problems (VRP) in B2C e-commerce, in which VRP is modeled by the incomplete graph based on the actual urban road system. First, a variant of classical VRP is described and a mathematical programming model for the variant is given. Second, the DDE is presented, where individuals are represented as the sequential encoding scheme, and a novel reparation operator is employed to repair the infeasible solutions. Furthermore, a FLOYD operator for dealing with the shortest route is embedded in the proposed DDE. Finally, an extensive computational study is carried out in comparison with the predatory search algorithm and genetic algorithm, and the results show that the proposed DDE is an effective algorithm for VRP in B2C e-commerce.

  9. Genetic Algorithm-based Dynamic Vehicle Route Search using Car-to-Car Communication

    Directory of Open Access Journals (Sweden)

    KIM, J.

    2010-11-01

    Full Text Available Suggesting more efficient driving routes generate benefits not only for individuals by saving commute time, but also for society as a whole by reducing accident rates and social costs by lessening traffic congestion. In this paper, we suggest a new route search algorithm based on a genetic algorithm which is more easily installable into mutually communicating car navigation systems, and validate its usefulness through experiments reflecting real-world situations. The proposed algorithm is capable of searching alternative routes dynamically in unexpected events of system malfunctioning or traffic slow-downs due to accidents. Experimental results demonstrate that our algorithm searches the best route more efficiently and evolves with universal adaptability.

  10. Applications of a saving method with max-min ant system to a vehicle routing problem with time windows and speed limits

    Directory of Open Access Journals (Sweden)

    Suphan Sodsoon

    2014-06-01

    Full Text Available This study aims to solve a Vehicle Routing Problem with Time Windows and Speed Limits (VRPTWSL, which has received considerable attention in recent years. The vehicle routing problem with time windows is an extension of the well-known Vehicle Routing Problem (VRP and involves a fleet of vehicles set of from a depot to serve a number of customers at different geographic locations with various demands within specific time and speed limits before returning to the depot eventually. To solve the problem, an efficient Saving Method-Max Min Ant System (Saving-MMAS with Local Search algorithm is applied. Using minimization of the total transportation costs as the objective of the extension VRPTWSL, a mathematic model is constructed. Finally, the Saving-MMAS algorithms indicated the good quality of the method in this problem.

  11. A multi-level variable neighborhood search heuristic for a practical vehicle routing and driver scheduling problem

    DEFF Research Database (Denmark)

    Wen, Min; Krapper, Emil; Larsen, Jesper;

    This paper addresses an integrated vehicle routing and driver scheduling problem arising at the largest fresh meat producer in Denmark. The problem consists of a one-week planning horizon, heterogeneous vehicles, and drivers with predefi ned work regulations. These regulations include, among other...... things, predefined workdays, fixed starting time, maximum weekly working duration, break rule. The objective is to minimize the total delivery cost. The real-life case study is fi rst introduced and modelled as a mixed integer linear program. A multilevel variable neighborhood search heuristic...... of the aggregated problem is expanded to that of the original problem. The method is implemented and tested on real-life data consisting of up to 2000 orders per week. Computational results show that the aggregation procedure and the decomposition strategy are very effective in solving this large scale problem...

  12. Exact Solutions to the Symmetric and Asymmetric Vehicle Routing Problem with Simultaneous Delivery and Pick-Up

    Directory of Open Access Journals (Sweden)

    Julia Rieck

    2013-05-01

    Full Text Available In reverse logistics networks, products (e.g., bottles or containers have to be transported from a depot to customer locations and, after use, from customer locations back to the depot. In order to operate economically beneficial, companies prefer a simultaneous delivery and pick-up service. The resulting Vehicle Routing Problem with Simultaneous Delivery and Pick-up (VRPSDP is an operational problem, which has to be solved daily by many companies. We present two mixed-integer linear model formulations for the VRPSDP, namely a vehicle-flow and a commodity-flow model. In order to strengthen the models, domain-reducing preprocessing techniques, and effective cutting planes are outlined. Symmetric benchmark instances known from the literature as well as new asymmetric instances derived from real-world problems are solved to optimality using CPLEX 12.1.

  13. Natural gas application in light- and heavy-duty vehicles in Brazil: panorama, technological routes and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Guilherme Bastos, Cordeiro de Melo, Tadeu Cavalcante; Leao, Raphael Riemke de Campos Cesar; Iaccarino, Fernando Aniello; Figueiredo Moreira, Marcia

    2007-07-01

    The Brazilian CNG light-duty vehicle fleet has currently reached more than 1,300,000 units. This growth increased in the late 1990's, when CNG was approved for use in passenger cars. In 2001, the IBAMA (Brazilian Institute for Environment and Natural Renewable Resources), concerned with this uncontrolled growth, published CONAMA (National Environmental Council, controlled by IBAMA) resolution 291, which establishes rules for CNG conversion kit environmental certification.This paper discusses the technological challenges for CNG-converted vehicles to comply with PROCONVE (Brazilian Program for Automotive Air Pollution Control) emission limits. In the 1980's, because of the oil crisis, Natural Gas (NG) emerged as a fuel with great potential to replace Diesel in heavy-duty vehicles. Some experiences were conducted for partial conversions from Diesel to NG (Diesel-gas). Other experiences using NG Otto Cycle buses were conducted in some cities, but have not expanded. Another technological route called 'Ottolization' (Diesel to Otto cycle convertion) appeared recently. Population increase and the great growth in vehicle fleet promote a constant concern with automotive emissions. More restrictive emission limits, high international oil prices, and the strategic interest in replacing Diesel imports, altogether form an interesting scenario for CNG propagation to public transportation in the main Brazilian metropolises.

  14. Vehicle routing for the eco-efficient collection of household plastic waste

    NARCIS (Netherlands)

    Bing, X.; Keizer, de M.; Bloemhof, J.M.; Vorst, van der J.G.A.J.

    2014-01-01

    Plastic waste is a special category of municipal solid waste. Plastic waste collection is featured with various alternatives of collection methods (curbside/drop-off) and separation methods (source-/post-separation). In the Netherlands, the collection routes of plastic waste are the same as those of

  15. Capacitive behaviour of MnF2 and CoF2 submicro/nanoparticles synthesized via a mild ionic liquid-assisted route

    Science.gov (United States)

    Ma, Ruguang; Zhou, Yao; Yao, Lin; Liu, Guanghui; Zhou, Zhenzhen; Lee, Jong-Min; Wang, Jiacheng; Liu, Qian

    2016-01-01

    Submicro-/nano-sized MnF2 rods and hierarchical CoF2 cuboids are respectively synthesized via a facile precipitation method assisted by ionic liquid under a mild condition. The as-prepared MF2 (M = Mn, Co) submicro/nanoparticles exhibit impressive specific capacitance in 1.0 M KOH aqueous solution, especially at relatively high current densities, e.g. 91.2, 68.7 and 56.4 F g-1 for MnF2, and 81.7, 70.6 and 63.0 F g-1 for CoF2 at 5, 8 and 10 A g-1, respectively. The mechanism of striking capacitance of MF2 is clarified on the basis of analysing the cycled electrodes by different characterization techniques. Such remarkable capacitance is ascribed to the redox reactions between MF2 and MOOH in aqueous alkaline electrolytes, which can not be obtained in aqueous neutral electrolytes. This study for the first time provides direct evidences on the pseudocapacitance mechanism of MF2 in alkaline electrolytes and paves the way of application of transition metal fluorides as electrodes in supercapacitors.

  16. Route of administration influences substitution patterns in rats trained to discriminate methadone vs. vehicle

    OpenAIRE

    Vann, Robert E.; Wise, Laura E.; Varvel, Stephen A.; Philibin, Scott D.; Walentiny, D. Matthew; Porter, Joseph H.

    2009-01-01

    Replacement therapy with the synthetic μ-opioid agonist methadone is an efficacious treatment for opioid abuse. While much is known about methadone’s pharmacology, its discriminative stimulus properties remain largely unexplored. The present study sought to establish methadone discrimination in rats. Moreover, some research suggests that route of administration alters the discriminative stimulus of methadone. Thus, the present study also compared intraperitoneal (i.p.) and subcutaneous (s.c.)...

  17. A Cooperative and Adaptive Variable Neighborhood Search for the Multi Depot Vehicle Routing Problem with Time Windows

    Directory of Open Access Journals (Sweden)

    Michael Polacek

    2008-12-01

    Full Text Available In this paper we propose two cooperation schemes to compose new parallel variants of the Variable Neighborhood Search (VNS. On the one hand, a coarse-grained cooperation scheme is introduced which is well suited for being enhanced with a solution warehouse to store and manage the so far best found solutions and a self-adapting mechanism for the most important search parameters. This makes an a priori parameter tuning obsolete. On the other hand, a fine-grained scheme was designed to reproduce the successful properties of the sequential VNS. In combination with the use of parallel exploration threads all of the best solutions and 11 out of 20 new best solutions for the Multi Depot Vehicle Routing Problem with Time Windows were found.

  18. Minimum Makespan Multi-Vehicle Dial-a-Ride

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath; Ravi, R.

    2015-01-01

    -vehicle Dial-a-Ride problem, there are q vehicles, each having capacity k and where each vehicle j epsilon [q] has its own depot-vertex r(j) epsilon V. A feasible schedule consists of a capacitated route for each vehicle (where vehicle j originates and ends at its depot r(j)) that together move all objects...... from their sources to destinations. The objective is to find a feasible schedule that minimizes the maximum completion time (i.e., makespan) of vehicles, where the completion time of vehicle j is the time when it returns to its depot r(j) at the end of its route. We study the preemptive version...

  19. A Space-Time Network-Based Modeling Framework for Dynamic Unmanned Aerial Vehicle Routing in Traffic Incident Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Jisheng Zhang

    2015-06-01

    Full Text Available It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and non-recurring traffic conditions and special events on transportation networks. This paper presents a space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism. By constructing a discretized space-time network to characterize not only the speed for UAVs but also the time-sensitive impact areas of traffic congestion, we formulate the problem as a linear integer programming model to minimize the detection delay cost and operational cost, subject to feasible flying route constraints. A Lagrangian relaxation solution framework is developed to decompose the original complex problem into a series of computationally efficient time-dependent and least cost path finding sub-problems. Several examples are used to demonstrate the results of proposed models in UAVs’ route planning for small and medium-scale networks.

  20. A Space-Time Network-Based Modeling Framework for Dynamic Unmanned Aerial Vehicle Routing in Traffic Incident Monitoring Applications

    Science.gov (United States)

    Zhang, Jisheng; Jia, Limin; Niu, Shuyun; Zhang, Fan; Tong, Lu; Zhou, Xuesong

    2015-01-01

    It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs) start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and non-recurring traffic conditions and special events on transportation networks. This paper presents a space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism. By constructing a discretized space-time network to characterize not only the speed for UAVs but also the time-sensitive impact areas of traffic congestion, we formulate the problem as a linear integer programming model to minimize the detection delay cost and operational cost, subject to feasible flying route constraints. A Lagrangian relaxation solution framework is developed to decompose the original complex problem into a series of computationally efficient time-dependent and least cost path finding sub-problems. Several examples are used to demonstrate the results of proposed models in UAVs’ route planning for small and medium-scale networks. PMID:26076404

  1. A Time-Slotted On-Demand Routing Protocol for Mobile Ad Hoc Unmanned Vehicle Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hope Forsmann; Robert Hiromoto; John Svoboda

    2007-04-01

    The popularity of UAVs has increased dramatically because of their successful deployment in military operations, their ability to preserve human life, and the continual improvements in wireless communication that serves to increase their capabilities. We believe the usefulness of UAVs would be dramatically increased if formation flight were added to the list of capabilities. Currently, sustained formation flight with a cluster of UAVs has only been achieved with two nodes by the Multi-UAV Testbed at the Massachusetts Institute of Technology. (Park, 2004) Formation flight is a complex operation requiring the ability to adjust the flight patterns on the fly and correct for wind gusts, terrain, and differences in node equipment. All of which increases the amount of inner node communication. Since one of the problems with MANET communication is network congestion, we believe a first step towards formation flight can be made through improved inner node communication. We have investigated current communication routing protocols and developed an altered hybrid routing protocol in order to provide communication with less network congestion.

  2. A capacitive DAC with custom 3-D 1-fF MOM unit capacitors optimized for fast-settling routing in high speed SAR ADCs

    Science.gov (United States)

    Chixiao, Chen; Jixuan, Xiang; Huabin, Chen; Jun, Xu; Fan, Ye; Ning, Li; Junyan, Ren

    2015-05-01

    Asynchronous successive approximation register (SAR) analog-to-digital converters (ADC) feature high energy efficiency but medium performance. From the point of view of speed, the key bottleneck is the unit capacitor size. In this paper, a small size three-dimensional (3-D) metal—oxide—metal (MOM) capacitor is proposed. The unit capacitor has a capacitance of 1-fF. It shapes as an umbrella, which is designed for fast settling consideration. A comparison among the proposed capacitor with other 3-D MOM capacitors is also given in the paper. To demonstrate the effectiveness of the MOM capacitor, a 6-b capacitive DAC is implemented in TSMC 1P9M 65 nm LP CMOS technology. The DAC consumes a power dissipation of 0.16 mW at the rate of 100 MS/s, excluding a source-follower based output buffer. Static measurement result shows that INL is less than ±1 LSB and DNL is less than ±0.5 LSB. In addition, a 100 MS/s 9-bit SAR ADC with the proposed 3-D capacitor is simulated.

  3. A capacitive DAC with custom 3-D 1-fF MOM unit capacitors optimized for fast-settling routing in high speed SAR ADCs

    International Nuclear Information System (INIS)

    Asynchronous successive approximation register (SAR) analog-to-digital converters (ADC) feature high energy efficiency but medium performance. From the point of view of speed, the key bottleneck is the unit capacitor size. In this paper, a small size three-dimensional (3-D) metal—oxide—metal (MOM) capacitor is proposed. The unit capacitor has a capacitance of 1-fF. It shapes as an umbrella, which is designed for fast settling consideration. A comparison among the proposed capacitor with other 3-D MOM capacitors is also given in the paper. To demonstrate the effectiveness of the MOM capacitor, a 6-b capacitive DAC is implemented in TSMC 1P9M 65 nm LP CMOS technology. The DAC consumes a power dissipation of 0.16 mW at the rate of 100 MS/s, excluding a source-follower based output buffer. Static measurement result shows that INL is less than ±1 LSB and DNL is less than ±0.5 LSB. In addition, a 100 MS/s 9-bit SAR ADC with the proposed 3-D capacitor is simulated. (paper)

  4. A Novel Spatial-Temporal Voronoi Diagram-Based Heuristic Approach for Large-Scale Vehicle Routing Optimization with Time Constraints

    Directory of Open Access Journals (Sweden)

    Wei Tu

    2015-10-01

    Full Text Available Vehicle routing optimization (VRO designs the best routes to reduce travel cost, energy consumption, and carbon emission. Due to non-deterministic polynomial-time hard (NP-hard complexity, many VROs involved in real-world applications require too much computing effort. Shortening computing time for VRO is a great challenge for state-of-the-art spatial optimization algorithms. From a spatial-temporal perspective, this paper presents a spatial-temporal Voronoi diagram-based heuristic approach for large-scale vehicle routing problems with time windows (VRPTW. Considering time constraints, a spatial-temporal Voronoi distance is derived from the spatial-temporal Voronoi diagram to find near neighbors in the space-time searching context. A Voronoi distance decay strategy that integrates a time warp operation is proposed to accelerate local search procedures. A spatial-temporal feature-guided search is developed to improve unpromising micro route structures. Experiments on VRPTW benchmarks and real-world instances are conducted to verify performance. The results demonstrate that the proposed approach is competitive with state-of-the-art heuristics and achieves high-quality solutions for large-scale instances of VRPTWs in a short time. This novel approach will contribute to spatial decision support community by developing an effective vehicle routing optimization method for large transportation applications in both public and private sectors.

  5. Tolerable Levels of Nonclinical Vehicles and Formulations Used in Studies by Multiple Routes in Multiple Species With Notes on Methods to Improve Utility.

    Science.gov (United States)

    Gad, Shayne Cox; Spainhour, Charles B; Shoemake, Catherine; Pallman, Danielle R Stackhouse; Stricker-Krongrad, Alain; Downing, Philip A; Seals, Richard E; Eagle, Leslie Anne; Polhamus, Kara; Daly, Jennifer

    2016-03-01

    Formulation of nonclinical evaluations is a challenge, with the fundamental need to achieve multiples of the clinical exposure complicated by differences in species and routes of administration-specific tolerances, depending on concentrations, volumes, dosing regimen, duration of each administration, and study duration. Current practice to approach these differences is based on individual experience and scattered literature with no comprehensive data source (the most notable exception being our 2006 publication on this same subject). Lack of formulation tolerance data results in excessive animal use, unplanned delays in the evaluation and development of drugs, and vehicle-dependent results. A consulting firm, a chemical company, and 4 contract research organizations conducted a rigorous data mining operation of vehicle data from studies dating from 1991 to 2015, enhancing the data from this author's 2006 publication (3 of the six 2015 contributors were also 2006 contributors). Additional data were found in the published literature. The results identified 108 single-component vehicles (and 305 combination formulations) used in more than 1,040 studies across multiple species (dog, primate, rat, mouse, rabbit, guinea pig, minipig, pig, chick embryo, and cat) by multiple routes for a wide range of study durations. The tabulated data include maximum tolerated use levels by species, route, duration of study, dose-limiting toxicity where reported, review of the available literature on each vehicle, guidance on syringe selection, volume and pH limits by route with basic guidance on nonclinical formulation development, and guidance on factors to be considered in nonclinical route selection. PMID:26755718

  6. Characterization of gaseous pollutants and PM2.5 at fixed roadsides and along vehicle traveling routes in Bangkok Metropolitan Region

    Science.gov (United States)

    Kim Oanh, N. T.; Kongpran, J.; Hang, N. T.; Parkpian, P.; Hung, N. T. Q.; Lee, S.-B.; Bae, G.-N.

    2013-10-01

    Traffic is a major source of air pollution in urban areas of developing countries that leads to high exposure risk of urban dwellers. This study comparatively investigated levels of fine particles (PM2.5), SO2, NO2, and BTEX (benzene, toluene, ethylbenzene and xylenes) at fixed roadsides and on traveling routes in congested urban and less congested suburban areas of Bangkok in 2010. The roadside air quality monitoring was done at two opposite sites across the selected roads. The traffic counting was made simultaneously in these roads and hourly flows of 8 different vehicle types were determined. Roadside PM2.5 levels during dry season were high in both the city center and suburban area, significantly above the wet season, with 65-75% measurements exceeded 24 h Thailand ambient air quality standard of 50 μg m-3. Oppositely, roadside BTEX levels measured in the city center during wet season were higher than dry season and well above those in suburban area. Diurnal variations and the results of SPSS (Statistical Package for the Social Sciences) analysis showed associations between roadside pollutants levels and hourly traffic flows. The differences in pollution levels between 2 monitoring sites across a road were explained by road configurations and prevalent wind directions. On-route pollution levels were measured simultaneously both inside and outside selected vehicles (van, pickup), and on motorcycle. The on-route PM2.5 levels along the urban route were higher during the dry season than wet season. PM2.5 levels inside the vehicles were lower than outside whereas the opposite was observed for BTEX. BTEX were higher on more congested urban sub-routes with lower vehicle speeds. Higher pollution levels suggest a high risk of exposure.

  7. Introducing the MCHF/OVRP/SDMP: multicapacitated/heterogeneous fleet/open vehicle routing problems with split deliveries and multiproducts.

    Science.gov (United States)

    Eroglu, Duygu Yilmaz; Gencosman, Burcu Caglar; Cavdur, Fatih; Ozmutlu, H Cenk

    2014-01-01

    In this paper, we analyze a real-world OVRP problem for a production company. Considering real-world constrains, we classify our problem as multicapacitated/heterogeneous fleet/open vehicle routing problem with split deliveries and multiproduct (MCHF/OVRP/SDMP) which is a novel classification of an OVRP. We have developed a mixed integer programming (MIP) model for the problem and generated test problems in different size (10-90 customers) considering real-world parameters. Although MIP is able to find optimal solutions of small size (10 customers) problems, when the number of customers increases, the problem gets harder to solve, and thus MIP could not find optimal solutions for problems that contain more than 10 customers. Moreover, MIP fails to find any feasible solution of large-scale problems (50-90 customers) within time limits (7200 seconds). Therefore, we have developed a genetic algorithm (GA) based solution approach for large-scale problems. The experimental results show that the GA based approach reaches successful solutions with 9.66% gap in 392.8 s on average instead of 7200 s for the problems that contain 10-50 customers. For large-scale problems (50-90 customers), GA reaches feasible solutions of problems within time limits. In conclusion, for the real-world applications, GA is preferable rather than MIP to reach feasible solutions in short time periods.

  8. A algorithm for the Vehicle Problem

    Directory of Open Access Journals (Sweden)

    Aziz Ezzatneshan

    2010-09-01

    Full Text Available In this paper, we propose a hybrid ACO algorithm for solving vehicle routing problem (VRP heuristically in combination with an exact In the basic VRP, geographically scattered customers of known demand are supplied from a single depot by a fleet of identically capacitated vehicles. The intuition of the proposed algorithm is that nodes which are near to each other will probably belong to the same branch of the minimum spanning tree of the problem graph and thus will probably belong to the same route in VRP. Given a clustering of client nodes, the solution is to find a route in these clusters by using ACO with a modified version of transition rule of the ants. At the end of each iteration, ACO tries to improve the quality of solutions by using a local search algorithm, and update the associated weights of the graph arcs.

  9. 多车场车辆路径问题及混合遗传算法%Multi-depot Vehicle Routing Problem with Hybrid Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    党立伟; 孙小明

    2012-01-01

    在多车场车辆路径问题中,综合考虑车辆的行驶路程和使用车辆的数量能有效降低配送成本,考虑了这两方面的因素建立了相应的数学模型,运用混合遗传算法进行了求解,并通过实例证明了模型和算法的有效性.%About the multi-depot vehicle routing problem, considering the distance traveled by the vehicle and the number of vehicles together can effectively reduce distribution costs. The corresponding mathematical model by taking the two factors into account is established, solved the model by using genetic algorithms and demonstrate the effectiveness of the model and algorithm by example.

  10. 需求可拆分的开放式车辆路径问题研究%Research on Split Delivery Open Vehicle Routing Problem

    Institute of Scientific and Technical Information of China (English)

    李三彬; 柴玉梅; 王黎明

    2011-01-01

    The traditional Open Vehicle Routing Problem(OVRP) assumes that the demand of the clients can not be split and the type of vehicles is the same, but in the practical logistics distribution, the type of vehicles is not exactly the same, sometimes the transportation cost can be reduced by splitting the demand of clients to make the best of the loading capacity of vehicles.This paper proposes the Split Delivery Open Vehicle Routing Problem with Heterogeneous Vehicles(SDOVRPHV), presents mathematic model of the integer programming of the problem, solves it with Tabu search algorithm and improves the generation of the initial solution and neighborhood structure in the algorithm.By experiments, the validity of the model is validated, and the results are compared with the traditional OVRP which indicates that the algorithm can reduce effectively the transportation cost.%传统的开放式车辆路径问题假设客户的需求不可拆分、车辆类型相同,但在实际的物流配送中,车辆类型不完全相同,对需求的拆分能充分利用车辆的装载能力,降低运输成本.为此,提出需求可拆分的不同种车辆的开放式车辆路径问题,给出整数规划的数学模型,利用禁忌搜索算法对该问题求解,改进算法中初始解和邻域结构的产生过程.通过实验验证模型的有效性,并将结果与传统的开放式车辆路径问题进行比较,表明该算法可有效减少运输成本.

  11. Study on vehicle routing problem based on heuristic ant colony optimization%基于启发式蚁群算法的VRP问题研究

    Institute of Scientific and Technical Information of China (English)

    刘晓勇; 付辉

    2011-01-01

    When Ant Colony Optimization algorithm (ACO) is applied to vehicle routing problem, it always spends much time and has worse solutions.This paper uses ACO based on a heuristic method for vehicle routing problem.This heuristic method combines distance matrix with saving route matrix to assign initial pheromone matrix.Three benchmark datasets are chosen to verify performance of the new algorithm. Experiments show that ant colony optimization based on heuristic information has better solution and spends less time.%针对蚁群算法求解VRP问题时收敛速度慢,求解质量不高的缺点,把城市和仓库间的距离矩阵和路径节约矩阵信息融入到初始信息素矩阵中作为启发式信息引入到蚁群算法中用于求解有容量限制的车辆路径规划问题(CVRP),在三个基准数据集上的实验研究表明,基于启发式信息的蚁群算法与基本蚁群算法相比能够以较快的速度收敛到较好的解.

  12. Issues of Routing in VANET

    OpenAIRE

    Raja, Umar Waqas; Mustafa, Bilal

    2010-01-01

    Vehicular Ad Hoc Network (VANET) is a sub class of mobile ad hoc networks. VANET provides wireless communication among vehicles and vehicle to road side equipments. The communication between vehicles is used for safety, comfort and for entertainment as well. The performance of communication depends on how better the routing takes place in the network. Routing of data depends on the routing protocols being used in network. In this study we investigated about different ad hoc routing protocols ...

  13. Intelligent Route Guidance for Heavy Vehicles : Project 031461 : D2.5 Models to estimate HGV impact on infrastructure to be used in route planning

    OpenAIRE

    Imine, Hocine; LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES - LCPC

    2009-01-01

    RAPPORT DE CONTRAT The aim of this report is to develop models to be used to estimate HGV impact on infrastructures (road and bridge). Vehicle characteristics and road data will be used as inputs to infrastructure behaviour models and simulation software to calculate load effects, in order to estimate and reduce the risks of infrastructure damage. Data will also be used to improve the understanding of the pavement deterioration process and optimise the maintenance operations. Traffic load ...

  14. Intelligent Route Guidance for Heavy Vehicles : Project 031461 :Deliverable 1.2 : Summary on System Architecture and Visions

    OpenAIRE

    ALEKSA, Michael; BLERVAQUE, Vincent; CEREZO, Veronique; DELEFOSSE, Rémi; DOLCEMASCOLO, Victor; EICHLOM, Claudia; Ihs, Anita; SJOGREN, Leif; SPIELHOFER, Roland; STUTZ, Rainer

    2007-01-01

    RAPPORT DE CONTRAT The main purpose of this report is to summarise the results of work package 1 System conception and User Requirements to a system architecture for the HeavyRoute project. This summary shall offer a structural basis for the other technical work packages, especially for work package 3 and work package 4. Work package 1 was dedicated to develop the system conception of HeavyRoute and to gather and analyse the user requirements for an intelligent routing, guidance and naviga...

  15. 基于ACS-GA算法的车辆路径问题研究%An ACS-GA Hybrid Optimization Method to Solve Vehicle Routing Problem

    Institute of Scientific and Technical Information of China (English)

    赵婉忻; 曲仕茹

    2011-01-01

    Vehicle routing problem is an important research area in intelligent transportation and business logistics. Planning the vehicle routes reasonably, reducing the delivery mileage and minimizing the cost of logistic distribution are great significance to increase economic efficiency. The paper focuses on vehicle routing problem with time windows in logistic distribution and establishes an improved mathematical model in which the delivery time and delivery distance is shortest. A novel hybrid optimization method integrating ant colony system with genetic algorithm ( ACS - GA) is presented. The initial solution is obtained by ant colony system. A genetic algorithm is used to improve the performance of ACS by reproduction, crossover and mutation operations. The ACS - GA hybrid optimization method can overcome the premature phenomenon and enhance the global search ability. Based on the benchmark datasets of vehicle routing problem with time windows, the experimental results demonstrate that the proposed method has a better ability to search the global optimal solution than other optimization methods.%物流配送车辆路径问题是智能交通和商业物流领域中一个重要研究方面.合理规划车辆的行驶路线,减少配送里程,降低物流成本,对提高经济效益具有重要意义.重点分析了带时间窗的物流配送车辆路径问题,建立了兼顾配送时间与配送距离最短的改进数学模型.提出了基于蚁群系统算法和遗传算法相融合的混合算法.该算法利用蚁群系统算法得到初始解,运用遗传算法中复制、交叉、变异操作对解的种群多样性进行扩充,克服了蚁群系统算法的早熟现象,增强了算法的全局搜索能力.基于标准数据集的实验结果表明,该算法与其他优化方法相比较,具有较好的搜索车辆路径最优解的能力.

  16. Clustering algorithm for split delivery vehicle routing problem%需求可拆分车辆路径问题的聚类求解算法

    Institute of Scientific and Technical Information of China (English)

    刘旺盛; 杨帆; 李茂青; 陈培芝

    2012-01-01

    In the traditional vehicle routing problems, customer demands are usually assumed that they can not be split. That is to say, a customer can only be severed by a vehicle. In fact, split delivery requires fewer vehicles, which reduces transportation costs. This paper analyzes the solution's characteristics of split delivery vehicle routing problem, and also proves the situations that customers' demands can not be split. A clustering algorithm meeting the solution's characteristics is designed to solve this problem. Compared with ant colony algorithm and tabu search algorithm, the proposed algorithm is demonstrated to obtain optimal solution more effectively through the simulation, and it is an effective method to solve split delivery vehicle routing problem.%针对传统的车辆路径问题通常假设客户的需求不能拆分,即客户的需求由一辆车满足,而实际上通过需求的拆分可使需要的车辆数更少,从而降低配送成本的问题,分析了需求可拆分的车辆路径问题的解的特征,证明了客户需求不宜拆分应满足的条件,设计了符合解的特征的聚类算法,并对其求解.通过实验仿真,将所提出的聚类算法与蚁群算法和禁忌搜索算法进行比较,所得结果表明了所提出的算法可以更有效地求得需求可拆分车辆路径问题的优化解,是解决需求町拆分车辆路径问题的有效方法.

  17. Route planning method for multiple vehicles coordinated target assignment%多机协同与多目标分配任务规划方法

    Institute of Scientific and Technical Information of China (English)

    魏铁涛; 屈香菊

    2009-01-01

    多架飞机攻击多个目标区域是现代作战方式的重要特征,多机协同与多目标分配问题是提高团队作战效能的关键.针对该问题,综合考虑飞机能力差异、协同方式和任务环境的变化,提出多机协同目标分配的任务规划方法.建立了基于能力裕度评价的多机协同目标分配问题的数学模型.对多目标分配问题,通过约束飞机的能力裕度对分配方案进行筛选,保证在战场环境发生改变时任务兵力的完整性.仿真结果表明,采用这种方法得到的目标分配方案,适应任务目标突发性变化的能力更强.%Multiple vehicles coordinated target assignment is the key problem to improve the efficiency of team fighting in the mission of multiple vehicles attacking multiple target regions. A route planning method for this problem was presented with consideration of the differences in vehicle ability, cooperation mode and the abrupt change of the battle field situation. Based on the evaluation of vehicle residual ability, a mathematical model of multiple vehicles coordinated target assignment had been built. The target assignment schemes were chosen by constraints on the vehicle residual ability, then the integrity of the military strength was ensured. The final simulation results of this model show that a stronger adaptability for abrupt change of mission objective can be gained.

  18. Research of Vehicle Routing Problem Based on Fuzzy Time Windows%基于模糊时间窗的车辆调度问题研究

    Institute of Scientific and Technical Information of China (English)

    王旭坪; 张凯; 胡祥培

    2011-01-01

    An increasing number of enterprises are focusing on the vehicle routing problems (VRP) because of expanded logistics support. VRP belongs to typical NP-Hard problems. An enterprise typically spends 25% to 30% of total expenses on vehicle routing problems because they can affect economic efficiency and customer benefits. Therefore, it is important to research VRP and optimize logistics activities.Exiting literature has focused on the vehicle routing problem with hard time and soft time windows. In the VRP with hard time window, the service time must fall within each customer' s time window. Due to the limitation of hard time window and the number of available vehicles, it is often unable to find feasible schedules. To deal with issues pertaining to the violation of time window, researchers have proposed the concept of "soft time window". In the VRP with soft time window, a penalty cost is added once a time window is violated, and the penalty cost is often assumed to be linear with the degree of violation. In some cases, violation of time window does not directly incur any penalty cost, although the satisfaction levels of customers may drop and lead to benefit loss in the long term. In many realistic applications, the hard time window or soft time window does represent customer requirements very well. Under these circumstances, the fuzzy processing of time window can reflect customers' requirements well and truly. Until now, few studies have addressed VRP-with fuzzy time window when the number of vehicle is limited. There are many real-life situations where the number of vehicle is limited, such as logistics distribution, post express and so on. Thus, this paper proposes and solves vehicle routing problems based on the fuzzy time window and a definite number of vehicles. In this paper, a fuzzy membership function is used to characterize customers' satisfaction levels by analyzing customers' practical requirements of the service time window.A multi-objective model

  19. False capacitance of supercapacitors

    OpenAIRE

    Ragoisha, G. A.; Aniskevich, Y. M.

    2016-01-01

    Capacitance measurements from cyclic voltammetry, galvanostatic chronopotentiometry and calculation of capacitance from imaginary part of impedance are widely used in investigations of supercapacitors. The methods assume the supercapacitor is a capacitor, while real objects correspond to different equivalent electric circuits and show various contributions of non-capacitive currents to the current which is used for calculation of capacitance. Specific capacitances which are presented in F g-1...

  20. The Information Modeling and Intelligent Optimization Method for Logistics Vehicle Routing and Scheduling with Multi-objective and Multi-constraint

    Institute of Scientific and Technical Information of China (English)

    LI Bei-zhi; ZHOU Ya-qin; LAN Shi-hai; YANG Jian-guo

    2007-01-01

    The vehicle routing and scheduling (VRS)problem with multi-objective and multi-constraint is analyzed, considering the complexity of the modern logistics in city economy and daily life based on the system engineering. The objective and constraint includes loading,the dispatch and arrival time, transportation conditions,total cost, etc. An information model and a mathematical model are built, and a method based on knowledge and biologic immunity is put forward for optimizing and evaluating the programs dimensions in vehicle routing and scheduling with multi-objective and multi-constraints. The proposed model and method are illustrated in a case study concerning a transport network, and the result shows that more optimization solutions can be easily obtained and the method is efficient and feasible. Comparing with the standard GA and the standard GA without time constraint,the computational time of the algorithm is less in this paper.And the probability of gaining optimal solution is bigger and the result is better under the condition of multi-con,traint.

  1. 基于模糊期望值模型的车辆路径问题%Vehicle routing problem based on fuzzy expected value model

    Institute of Scientific and Technical Information of China (English)

    王连锋; 宋建社; 杨正磊; 曹继平

    2012-01-01

    Aiming at the vehicle routing problem with fuzzy demands, the probability of vehicle service failure was analyzed based on fuzzy credibility theory, and a fuzzy expected value model was formulated. A parallel particle swarm optimization with double layers tabu search was proposed for routes optimization. In this algorithm, two different types of tabu search space were inserted, and two neighborhood arithmetic operators were designed by using new iterative formula and roulette strategy. The effectiveness of proposed method was verified by simulation contrast tests.%针对模糊需求的车辆路径问题,基于模糊可信性理论对车辆服务失败事件进行可能性分析,建立了一个模糊期望值模型,提出一种带双层禁忌搜索的并行粒子群算法。该算法引入两种不同的禁忌空间,采用新的粒子迭代公式,并利用轮盘赌策略设计了两类邻域算子。通过仿真对比实验表明了该算法的有效性。

  2. Combined Coverage Area Reporting and Geographical Routing in Wireless Sensor-Actuator Networks for Cooperating with Unmanned Aerial Vehicles

    NARCIS (Netherlands)

    Hoesel, van Lodewijk; Tüysüz-Erman, Aysegul; Havinga, P.J.M.; Brogle, Marc; Heijenk, Geert; Braun, Torsten; Konstantas, Dimitri

    2009-01-01

    In wireless sensor network (WSN) applications with multiple gateways, it is key to route location dependent subscriptions efficiently at two levels in the system. At the gateway level, data sinks must not waste the energy of the WSN by injecting subscriptions that are not relevant for the nodes in t

  3. VANET Routing Protocols: Pros and Cons

    OpenAIRE

    Paul, Bijan; Ibrahim, Md.; Bikas, Md. Abu Naser

    2012-01-01

    VANET (Vehicular Ad-hoc Network) is a new technology which has taken enormous attention in the recent years. Due to rapid topology changing and frequent disconnection makes it difficult to design an efficient routing protocol for routing data among vehicles, called V2V or vehicle to vehicle communication and vehicle to road side infrastructure, called V2I. The existing routing protocols for VANET are not efficient to meet every traffic scenarios. Thus design of an efficient routing protocol h...

  4. 物流配送车辆调度问题算法综述%Research on Algorithm of Delivery Vehicle Routing Problems

    Institute of Scientific and Technical Information of China (English)

    陈君兰; 叶春明

    2012-01-01

    Delivery vehicle routing problems (VRP) is a kind of optimization problems, aiming at solving the vehicle routing problems in delivery section. And they have been a focus of research in logistics control optimization recently. After summarize different kinds of VRP, the article gives the relevant general models. The character and the application of genetic algorithm, simulated annealing, tabu search, ant colony algorithm, particle swarm optimization are analyzed and the current possibilities to solve VRP are also discussed. Finally, the development of VRP solution is presented, and point out that improved combined algorithm as well as new algorithm will be important measures to solve VRP.%配送车辆调度优化问题旨在解决配送中路径和车辆调度问题的一类组合优化问题,是近年来物流控制优化领域的研究热点。文章对运输调度问题进行了分类总结,给出总体模型的概括描述,分析遗传算法、模拟退火算法、禁忌搜索算法、蚁群算法和微粒群算法的特点及其在求解配送车辆调度优化问题中的求解思路,并讨论了其求解现状,对未来研究方向进行展望,指出改进混合现有算法,开拓新算法将是更有效解决配送车辆调度问题的好方法。

  5. Routing and scheduling problems

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander

    of a connection between two locations. This could be an urban bus schedule where busses are routed and this routing creates a bus schedule which the passengers between locations use. In this thesis various routing and scheduling problems will be presented. The topics covered will be routing from an origin...... set cost making the cost of the individual vehicle routes inter-dependant. Depending on the problem type, the size of the problems and time available for solving, different solution methods can be applicable. In this thesis both heuristic methods and several exact methods are investigated depending...... on the problems needed to be solved. The solution methods applied to the problems cover dynamic programming for multi constrained shortest paths, Branch-and-cut for liner shipping, Simulated annealing for transporting assisted passengers in airports, branch-cut-and-price for vehicle routing with time windows...

  6. Research on optimizing vehicle routing based on intelligent hybrid algorithm%基于智能混合算法的车辆配送路径优化

    Institute of Scientific and Technical Information of China (English)

    汪岚

    2015-01-01

    为提高车辆配送效率,节约配送成本,建立了以配送路径和成本综合最优为目标的车辆配送路径问题数学模型.设计并实现了一种智能混合算法,首先利用具有自适应交叉率和变异率的改进遗传算法生成全局较优解,再将较优解转换为初始信息素进行蚁群算法,并结合2-opt 算法对解进一步迭代优化,最终获得了车辆最优配送路径.实验结果表明,该算法优化后的目标值比蚁群算法减少了15.0%,比遗传算法减少了10.4%,验证了该算法的有效性和优越性.%In order to improve the efficiency and reduce the cost of vehicle delivery,a VRF mathematic model on optimizing vehicle routing and cost was established.An intelligent hybrid algorithm was proposed.Hybrid genetic algorithm which combined with self-adaptive crossover rate and mutation rate was used in the algo-rithm to conduct the global better solution.Then the better solution was taken as the initial solution of the ant colony algorithm and the stage solution was optimized by 2-opt algorithm to obtain the best vehicle routing. The experimental result showed that the objective value based on hybrid algorithm was 15.0% less than ant colony algorithm and 10.4% less than genetic algorithm,so the efficiency and superiority of the intelligent hybrid algorithm were proved.

  7. Routing Service Quality—Local Driver Behavior Versus Routing Services

    DEFF Research Database (Denmark)

    Ceikute, Vaida; Jensen, Christian S.

    2013-01-01

    of the quality of one kind of location-based service, namely routing services. Specifically, the paper presents a framework that enables the comparison of the routes provided by routing services with the actual driving behaviors of local drivers. Comparisons include route length, travel time, and also route...... experiments with real vehicle trajectory data and an existing online navigation service. It is found that the availability of information about previous trips enables better prediction of route travel time and makes it possible to provide the users with more popular routes than does a conventional navigation...

  8. Conductive two-dimensional titanium carbide 'clay' with high volumetric capacitance.

    Science.gov (United States)

    Ghidiu, Michael; Lukatskaya, Maria R; Zhao, Meng-Qiang; Gogotsi, Yury; Barsoum, Michel W

    2014-12-01

    Safe and powerful energy storage devices are becoming increasingly important. Charging times of seconds to minutes, with power densities exceeding those of batteries, can in principle be provided by electrochemical capacitors--in particular, pseudocapacitors. Recent research has focused mainly on improving the gravimetric performance of the electrodes of such systems, but for portable electronics and vehicles volume is at a premium. The best volumetric capacitances of carbon-based electrodes are around 300 farads per cubic centimetre; hydrated ruthenium oxide can reach capacitances of 1,000 to 1,500 farads per cubic centimetre with great cyclability, but only in thin films. Recently, electrodes made of two-dimensional titanium carbide (Ti3C2, a member of the 'MXene' family), produced by etching aluminium from titanium aluminium carbide (Ti3AlC2, a 'MAX' phase) in concentrated hydrofluoric acid, have been shown to have volumetric capacitances of over 300 farads per cubic centimetre. Here we report a method of producing this material using a solution of lithium fluoride and hydrochloric acid. The resulting hydrophilic material swells in volume when hydrated, and can be shaped like clay and dried into a highly conductive solid or rolled into films tens of micrometres thick. Additive-free films of this titanium carbide 'clay' have volumetric capacitances of up to 900 farads per cubic centimetre, with excellent cyclability and rate performances. This capacitance is almost twice that of our previous report, and our synthetic method also offers a much faster route to film production as well as the avoidance of handling hazardous concentrated hydrofluoric acid. PMID:25470044

  9. Conductive two-dimensional titanium carbide `clay' with high volumetric capacitance

    Science.gov (United States)

    Ghidiu, Michael; Lukatskaya, Maria R.; Zhao, Meng-Qiang; Gogotsi, Yury; Barsoum, Michel W.

    2014-12-01

    Safe and powerful energy storage devices are becoming increasingly important. Charging times of seconds to minutes, with power densities exceeding those of batteries, can in principle be provided by electrochemical capacitors--in particular, pseudocapacitors. Recent research has focused mainly on improving the gravimetric performance of the electrodes of such systems, but for portable electronics and vehicles volume is at a premium. The best volumetric capacitances of carbon-based electrodes are around 300 farads per cubic centimetre; hydrated ruthenium oxide can reach capacitances of 1,000 to 1,500 farads per cubic centimetre with great cyclability, but only in thin films. Recently, electrodes made of two-dimensional titanium carbide (Ti3C2, a member of the `MXene' family), produced by etching aluminium from titanium aluminium carbide (Ti3AlC2, a `MAX' phase) in concentrated hydrofluoric acid, have been shown to have volumetric capacitances of over 300 farads per cubic centimetre. Here we report a method of producing this material using a solution of lithium fluoride and hydrochloric acid. The resulting hydrophilic material swells in volume when hydrated, and can be shaped like clay and dried into a highly conductive solid or rolled into films tens of micrometres thick. Additive-free films of this titanium carbide `clay' have volumetric capacitances of up to 900 farads per cubic centimetre, with excellent cyclability and rate performances. This capacitance is almost twice that of our previous report, and our synthetic method also offers a much faster route to film production as well as the avoidance of handling hazardous concentrated hydrofluoric acid.

  10. Mesoscopic Capacitance Oscillations

    OpenAIRE

    Buttiker, Markus; Nigg, Simon

    2006-01-01

    We examine oscillations as a function of Fermi energy in the capacitance of a mesoscopic cavity connected via a single quantum channel to a metallic contact and capacitively coupled to a back gate. The oscillations depend on the distribution of single levels in the cavity, the interaction strength and the transmission probability through the quantum channel. We use a Hartree-Fock approach to exclude self-interaction. The sample specific capacitance oscillations are in marked contrast to the c...

  11. 节点具有双重需求的车辆路径问题及其性质%THE VEHICLE ROUTING PROBLEM AND IT'S PROPERTY WITH NODES HAVING DOUBLE DEMANDS

    Institute of Scientific and Technical Information of China (English)

    王科峰; 叶春明; 唐国春

    2011-01-01

    Based on the original definition of the Simultaneous Pickup and Delivery Vehicle Routing Problem, the relationship between the vehicle's capacity and the demand of the node was expanded into the case that the later was permitted to be greater than the former. Then the reducibility of the Simultaneous Pickup and Delivery Vehicle Routing Problem and the Split Vehicle Routing Problem with Pickup and Delivery was studied. The reducibility definitions of these two problems were given. It follows that when the distance satisfies the triangle inequality and the vehicle's capacity is equal to 1, the Split Vehicle Routing Problem with Pickup and Delivery is reducible and equivalent to the Simultaneous Pickup and Delivery Vehicle Routing Problem, and that when the vehicle's capacity is greater than or equal to 2, these two problems were irreducible. Then the complexity of these two problems is proved when the vehicle's capacity was equal to 1 and greater than or equal to 3. Finally an example shows the obvious structural difference of the optimal solutions between the Split Vehicle Routing Problem with Pickup and Delivery and the Split Vehicle Routing Problem.%在原有同时收发车辆路径问题定义的基础上,将节点需求与车辆容量的关系拓展到允许节点需求大于车辆容量的情形.接着对集送货需求可拆分车辆路径问题和同时收发车辆路径问题的可简化性进行了研究.给出了两类问题可简化的定义,并得到了当距离满足三角不等式,车辆容量为1时集送货需求可拆分车辆路径问题可简化并与同时收发车辆路径问题等价,而当容量大于等于2时两类问题都不可以简化的结论.同时也对两类问题当车辆容量等于1时,以及大于等于3时的计算复杂性给出了证明.最后通过一个实例说明了集送货需求可拆分车辆路径问题与同时收发车辆路径问题在最优解的结构性质方面存在着明显差异.

  12. Vehicle Routing Problem with Nodes of Double Demands and the Property of Its Solution%节点具有双重需求车辆路径问题及其解的性质分析

    Institute of Scientific and Technical Information of China (English)

    王科峰; 叶春明

    2013-01-01

    A general outline of various types of vehicle routing problems in the field of reverse logistics was given.The vehicle routing problems were divided into two classes,i.e.the problem of single demand and double demands,according to the demand characteristic of the customer node.The vehicle routing problem with simultaneous delivery and pickup (VRPSDP) and the vehicle routing problem with split deliveries and pickups (SVRPPD) were called as the vehicle routing problem with nodes of double demands (VRPNDD).Their definitions and mathematic models were given.Then as the preliminary work for designing the heuristics,some constitutive properties of the solution for the VRPNDD were investigated.The difference in properties of optimal solutions between SVRPPD and SDVRP (the vehicle routing problem with split delivery) was illustrated,and a theorem was proved to show the significance of the heuristics' improving on cost saving analysis of SVRPPD relative to VRPSDP.%概括介绍了逆向物流领域中的各类车辆路径问题,将问题按照节点的需求类型分为节点单需求以及具有双重需求两个大类.按照节点的需求类型,将同时送取货(VRPSDP)、集送货需求可拆分车辆路径问题(SVRPPD)统称为节点具有双重需求车辆路径问题(VRPNDD).文中首先给出了它们的定义及数学模型.接着,作为设计求解问题启发式算法的前期工作,对VRPNDD问题解的结构方面的一些性质进行了分析证明.最后,举例说明了SVRPPD与送货需求可拆分车辆路径问题最优解性质方面的差异,并通过定理证明说明了SVRPPD,VRPSDP启发式算法的改良对于SVRPPD相对VRPSDP节省成本百分比研究的意义.

  13. Memetic algorithm for vehicle routing problem with time windows%基于Memetic算法的带时间窗车辆路径问题研究

    Institute of Scientific and Technical Information of China (English)

    吴雷; 魏臻; 葛方振

    2012-01-01

    This paper proposed a Memetic algorithm, which simulated the process of culture evolution, to solve vehicle routing problem with time windows(VRPTW). To convert VRPTW into continuous problem, it designed a real coding method. The memetic algorithm helped the particles which had certain learning capacity accelerate convergence rate by local search strategy. Meanwhile, because of helping some particles which fell into the local optimum escape from local optimum by tabu search, it enhanced the diversity of swarm. The experimental result shows that the proposed algorithm can gel the solution more effectively and it is an effective method for VRPTW.%提出一种模拟文化进化的Memetic算法求解带时间窗的车辆路径问题.设计了一种实数编码方案,将离散的问题转为连续优化问题.采用邻域搜索帮助具备一定学习能力的个体提高寻优速度;采用禁忌搜索帮助部分个体跳出局部最优点,增强全局寻优性能.实验结果表明,该算法可以更有效地求出优化解,是带时间窗车辆路径问题的一种有效求解算法.

  14. Variable Synthetic Capacitance

    Science.gov (United States)

    Kleinberg, L. L.

    1986-01-01

    Feedback amplifier circuit synthesizes electronically variable capacitance. Variable Synthetic Capacitor is amplifier circuit with follower/feedback configuration. Effective input capacitance depends on input set current. If synthetic capacitor is connected across resonant element of oscillator, oscillator frequency controlled via input set current. Circuit especially suitable for fine frequency adjustments of piezoelectric-crystal or inductor/capacitor resonant oscillators.

  15. 车载导航系统的市场渗透率仿真研究%Simulation on Route Guidance Benefit of In-Vehicle Navigation System

    Institute of Scientific and Technical Information of China (English)

    杨珍珍; 干宏程

    2012-01-01

    In-vehicle navigation system (1VNS) usually provides real-time traffic information to assist drivers to choose optimal routes. To explore the route guidance effect of IVNS' s market penetration rate to freeway networks, including traffic benefit and environment benefit, this paper uses macroscopic dynamic traffic network model to develop a simulation platform. It uses dynamic traffic assignment model to describe route guidance mechanism of the IVNS and adopts total waiting time and total time spend as traffic benefit indicator. The VT-Micro model is used to measure vehicle emissions and fuel consumption. Moreover, the study calculates the direct economic benefits in terms of air pollutant treatment cost saving and fuel consumption. Taking a network with two origins and two destinations as an example, the simulation shows that the IVNS can effectively equilibrium freeway network' s demand, improve freeway network efficiency, reduce mobile source emissions and create huge economic benefits. Market penetration rate is recommended to value from 0. 2 to 0. 3 in view of traffic benefits and environment benefits. This simulation system iseffective for designing and evaluating the IVNS. It also provides the basis for decision-making and references for relevant departments to improve the operational efficiency of traffic networks.%车载导航系统(IVNS)能提供实时有效交通信息辅助驾驶人选择最佳路径.为了探讨IVNS的市场渗透率对路网运行效益(交通效益和环境效益两方面)的影响,本文运用宏观动态交通网络模型METANET建立仿真平台,用反馈式动态交通分配模型描述IVNS路径诱导下驾驶人的行为,以总排队时间和总耗费时间作为交通效益评价指标,用反映速度—加速度关系的机动车排放和燃油消耗关系模型——VT-Micro模型计算机动车排放量和燃油消耗量,并用货币价值量化排放减少带来的直接经济效益(包括大气污染治理费用和燃油

  16. 车辆路径问题:从时间地理学的视角%Vehicle Routing Problem:From a Perspective of Time Geography

    Institute of Scientific and Technical Information of China (English)

    戚铭尧; 吴涛; 张新

    2015-01-01

    车辆路径问题具有典型的时空分布特征,受到众多时空约束条件的制约。在车辆路径规划中,综合考虑时间和空间因素是非常必要的。本文从时间地理学这一全新的视角来研究车辆路径问题,提出一套完整的时间地理学分析框架,阐述了时间地理学的基本概念,提出了车辆路径问题中的时空约束、时空路径、时空棱柱、时空可达性、时空距离等概念,并给出了图示或定量化的度量方法。论文提出的时空距离度量方法综合考虑了顾客在空间位置和时间窗口2个方面的特征,可更科学地判定顾客之间的“邻近性”。论文通过设计一种求解大规模软时间窗车辆路径问题的算法,证明了时空距离的价值,并展望了时间地理学在求解动态车辆路径规划问题、移动设施路径规划问题等方面的应用。本文的贡献在于,通过时间地理学所提供的一系列概念和方法,实现了在统一的框架下同时考虑车辆路径问题(VRP)的时间和空间特征的构想,挖掘了传统时间地理学理论在车辆路径领域中的应用潜力,这将有利于更快或者更好地求解VRP问题。%Vehicle routing problem (VRP) has typical characteristics of space-time distribution, thus it is influ-enced by constrains of space-time conditions. It is necessary to take the space and time factors comprehensively into the consideration of vehicle routing planning. In this paper, we proposed a new perspective to investigate ve-hicle routing problem and introduced a complete analytic framework from the aspects of time geography. Fol-lowed by the introduction of the fundamental theory of time geography, concepts including space-time con-straints, space-time path, space-time prism, space-time accessibility, and space-time distance are illustrated in the context of VRP. Meanwhile, the diagrammatic and metric methods of these concepts are also provided. In

  17. Unmanned Aerial Vehicle Route Planning for Traffic Information Collection%面向交通信息采集的无人飞机路径规划

    Institute of Scientific and Technical Information of China (English)

    刘晓锋; 彭仲仁; 张立业; 李立

    2012-01-01

    引入无人飞机作为城市道路固定交通检测设备的辅助手段,部署无人飞机进行道路交通信息采集,提出了无人飞机的路径规划问题.考虑了无人飞机数量有限,不足以对所有目标进行侦察的情形,建立了以总巡航距离最短、巡航目标数量最多的多目标优化模型,提出了可行路径的重组方法,构造了求解该问题的非支配排序遗传算法.案例分析结果表明:构造的算法可以求出无人飞机路径规划的近似最优解,与最优初始可行解相比,总巡航距离减少了13.07%,巡航目标数量增加了41.67%.最后,讨论了无人飞机在道路交通信息采集中可能面临的问题.%In this paper, the unmanned aerial vehicle (UAV) route planning problem is introduced to deploy the UAV for road traffic information collection. The scenario of using limited UAVs to detect road sections is considered, and a multi-objective optimization model is developed, which uses the number of the UAVs and UAV maximum cruise distance as constraints and aims to minimize the total cruise distance and maximize the number of detected road sections. A novel non-dominated sorting genetic algorithm for this problem is then proposed. The case study shows that the nearly optimal solution for planning UAV routes can be acquired effectively. Compared the obtained solution with the optimal feasible solution, the total cruise distance is reduced by 13.07% and the number of detected targets is increased by 41.67%. Finally, some issues on deploying UAVs for traffic information collection are discussed.

  18. VANET Routing Protocols: Pros and Cons

    CERN Document Server

    Paul, Bijan; Bikas, Md Abu Naser

    2012-01-01

    VANET (Vehicular Ad-hoc Network) is a new technology which has taken enormous attention in the recent years. Due to rapid topology changing and frequent disconnection makes it difficult to design an efficient routing protocol for routing data among vehicles, called V2V or vehicle to vehicle communication and vehicle to road side infrastructure, called V2I. The existing routing protocols for VANET are not efficient to meet every traffic scenarios. Thus design of an efficient routing protocol has taken significant attention. So, it is very necessary to identify the pros and cons of routing protocols which can be used for further improvement or development of any new routing protocol. This paper presents the pros and cons of VANET routing protocols for inter vehicle communication.

  19. Research on the Vehicle Route Planning Determined by Quantity Demand%需求量确定的车辆线路规划研究

    Institute of Scientific and Technical Information of China (English)

    葛长飞

    2014-01-01

    Recently, the logistics industry is rapidly developed. The cost effectiveness has become the focus of enterprises. Transportation cost is an important factor that affects the logistics costs. The existing vehicle route planning researches lack a consideration of the demand, which makes it difficult to adapt to actual demand change. This paper optimizes the existing BRP basic model in the aspect of demand, establishes the function model deter-mined by demand, uses LINGO software to solve, and studies the numerical example, verifies the model, reason-ably plans and designs the business lines and reduce the logistics costs, which is of a theoretical reference value.%近几年,物流业发展迅猛,成本效益已成为企业关注的焦点,运输成本是影响物流成本的重要因素。现有的车辆线路规划研究中,缺少对需求量因素的考虑,难以适应需求量变动的实际情况。本文在需求量方面对现有VRP基本模型进行优化,建立需求量确定的函数模型,运用LINGO软件进行求解,再进行算例分析,对模型进行验证。这对企业进行科学的线路规划设计,降低物流成本,具有重要的理论参考意义。

  20. Dijkstra算法在GIS车辆诱导系统的优化实现%Efficient implementation of Dijkstra algorithm in vehicle route guidance system based on GIS

    Institute of Scientific and Technical Information of China (English)

    殷招伟; 戴文博; 钱俊彦

    2015-01-01

    The interdisciplinary application of intelligent transportation system comes into being just to meet people’s growing demand.The analysis of shortest path is the key problem in the application of VRGS (Vehicle Route Guidance System), the Dijkstra algorithm is the common algorithm to solve this problem effectively. Combined two-tree Dijkstra algorithm and multi-core and multi-threading technology, this paper optimizes and improves the traditional Dijkstra algorithm. And it discusses the application of the algorithm in VRGS.At last, this paper poves its practicality and efficiency by simulating the shortest path search process of Guilin.%为了满足人们日益增长的出行需求,跨学科的智能交通系统应运而生。最短路径分析是GIS车辆诱导系统应用的关键问题,Dijkstra 算法是解决该问题的常用算法。文章结合二树 Dijkstra 算法的思想和现代多核多线程的技术,对 Dijkstra算法进行了优化与改进,并对该算法在车辆诱导系统中的应用进行了探讨。该系统以桂林市为例模拟了最短路径搜过程,证明该算法的高效性和实用性。

  1. Capacitive chemical sensor

    Science.gov (United States)

    Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

    2014-05-27

    A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  2. System for Measuring Capacitance

    Science.gov (United States)

    McNichol, Randal S. (Inventor)

    2001-01-01

    A system has been developed for detecting the level of a liquid in a tank wherein a capacitor positioned in the tank has spaced plates which are positioned such that the dielectric between the plates will be either air or the liquid, depending on the depth of the liquid in the tank. An oscillator supplies a sine wave current to the capacitor and a coaxial cable connects the capacitor to a measuring circuit outside the tank. If the cable is very long or the capacitance to be measured is low, the capacitance inherent in the coaxial cable will prevent an accurate reading. To avoid this problem, an inductor is connected across the cable to form with the capacitance of the cable a parallel resonant circuit. The impedance of the parallel resonant circuit is infinite, so that attenuation of the measurement signal by the stray cable capacitance is avoided.

  3. Capacitance pressure sensor

    Science.gov (United States)

    Eaton, William P.; Staple, Bevan D.; Smith, James H.

    2000-01-01

    A microelectromechanical (MEM) capacitance pressure sensor integrated with electronic circuitry on a common substrate and a method for forming such a device are disclosed. The MEM capacitance pressure sensor includes a capacitance pressure sensor formed at least partially in a cavity etched below the surface of a silicon substrate and adjacent circuitry (CMOS, BiCMOS, or bipolar circuitry) formed on the substrate. By forming the capacitance pressure sensor in the cavity, the substrate can be planarized (e.g. by chemical-mechanical polishing) so that a standard set of integrated circuit processing steps can be used to form the electronic circuitry (e.g. using an aluminum or aluminum-alloy interconnect metallization).

  4. Induced Charge Capacitive Deionization

    OpenAIRE

    Rubin, S.; Suss, M. E.; Biesheuvel, P. M.; Bercovici, M.

    2016-01-01

    We demonstrate the phenomenon of induced-charge capacitive deionization (ICCDI) that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electrostatic field. The external electric field induces an electric dipole in the porous particle, leading to capacitive charging of its volume by both cations and anions at opposite poles. This regime is characterized both by a large RC charging time and a small electrochemical charge relaxation time, ...

  5. Nonlinear Quantum Capacitance

    OpenAIRE

    Wang, B; Zhao, X; Guo, H; Wang, J.

    1999-01-01

    We analyze the nonlinear voltage dependence of electrochemical capacitance for nanoscale conductors. This voltage dependence is due to the finite density of states of the conductors. Within Hartree theory we derive an exact expression for the electrochemical capacitance–voltage curve for a parallel plate system. The result suggests a quantum scanning capacitance microscopy at the nanoscale: by inverting the capacitance–voltage expression one is able to deduce the local spectral function of th...

  6. Quantum capacitance: a microscopic derivation

    OpenAIRE

    Mukherjee, Sreemoyee; MANNINEN, M; Deo, P. Singha

    2010-01-01

    We start from microscopic approach to many body physics and show the analytical steps and approximations required to arrive at the concept of quantum capacitance. These approximations are valid only in the semi-classical limit and the quantum capacitance in that case is determined by Lindhard function. The effective capacitance is the geometrical capacitance and the quantum capacitance in series, and this too is established starting from a microscopic theory.

  7. The production process route optimization of rail vehicle based on directed weighted networks%基于有向加权网的轨道车辆生产工艺路线优化研究

    Institute of Scientific and Technical Information of China (English)

    刘云龙; 印玺

    2015-01-01

    为解决城市轨道车辆生产线存在的生产效率不高与稳定性差等问题,提出了一种基于有向加权网络的城市轨道车辆工艺路线优化方法。该方法首先利用有向加权网络理论构建车辆生产线的生产网络模型,然后以生产线可靠性与制造成本为目标,建立轨道车辆工艺路线的多目标优化模型,并基于粒子群算法得到最优工艺路线生成算法,最后以某轨道列车生产线为例进行了验证,结果表明,该方法能显著降低生产线的生产成本,提高生产线的生产效率与稳定性。%The process route optimization of rail vehicle production is a complicated problem.It proposes a direct-ed weighted network to establish the complex processing relationships among working stations, takes the manufac-turing cost and the reliability of the rail vehicle production route as object.In order to improve the reliability of production route, it builds an optimization model combining the reliability of the production route and manufac-turing cost, designs particle swarm algorithm for the optimal process route generation.The results prove the effec-tive of the optimization method.

  8. High bandwidth on-chip capacitive tuning of microtoroid resonators.

    Science.gov (United States)

    Baker, Christopher G; Bekker, Christiaan; McAuslan, David L; Sheridan, Eoin; Bowen, Warwick P

    2016-09-01

    We report on the design, fabrication and characterization of silica microtoroid based cavity opto-electromechanical systems (COEMS). Electrodes patterned onto the microtoroid resonators allow for rapid capacitive tuning of the optical whispering gallery mode resonances while maintaining their ultrahigh quality factor, enabling applications such as efficient radio to optical frequency conversion, optical routing and switching applications. PMID:27607646

  9. High bandwidth on-chip capacitive tuning of microtoroid resonators

    CERN Document Server

    Baker, Christopher G; McAuslan, David L; Sheridan, Eoin; Bowen, Warwick P

    2016-01-01

    We report on the design, fabrication and characterization of silica microtoroid based cavity opto-electromechanical systems (COEMS). Electrodes patterned onto the microtoroid resonators allow for rapid capacitive tuning of the optical whispering gallery mode resonances while maintaining their ultrahigh quality factor, enabling applications such as efficient radio to optical frequency conversion, optical routing and switching applications.

  10. 带服务优先级的煤矿物资配送车辆路径问题%On the Vehicle Routing Problem for the Coal Mine Materials' Distribution with Service Priorities

    Institute of Scientific and Technical Information of China (English)

    郭海湘; 杨娟; 於世为; 廖貅武

    2012-01-01

    以运输费用最小为目标,在考虑客户服务优先级和车辆装载率等约束条件下,构建了单车场单车型联合运输车辆路径问题模型和单车场多车型单点配送多趟服务车辆路径问题模型,并用改进的扫描算法和改进的遗传算法进行求解,最后,将郑州煤电物资供销有限公司的物资配送作为案例进行研究,从运输费用、运输里程和服务优先级三方面评价改进的扫描算法和改进的遗传算法的求解结果,得到在车辆装载率相同的情况下,两者各有所侧重:改进的遗传算法所求得的最优解在运输费用和配送里程上都优于改进的扫描算法,而改进的扫描算法则最大程度地保证了客户的服务优先级.%To minimize the delivering cost, we build a single-depot combined delivering vehicle routing problem model and a single-depot point-to-point delivering vehicle routing problem model, considering the constraints on the customers' service priorities and the full load rate of vehicles. We then present an improved sweeping algorithm and improved genetic algorithm to solve the mathematical models. We also study vehicle routing problem for Zhengzhou Coal Electricity Material Supply and Marketing Limited Company, evaluate the solutions in terms of delivery cost, delivery distance and full load rate of vehicles. The results show that, in the situation with the same full load rate of the vehicles, the best solution of the improved genetic algorithm is better than that of the improved sweeping algorithm in terms of delivery cost and delivery distance However, the improved sweeping algorithm provides guarantee for the service priority.

  11. Membrane capacitive deionization

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Wal, van der A.

    2010-01-01

    Membrane capacitive deionization (MCDI) is an ion-removal process based on applying an electrical potential difference across an aqueous solution which flows in between oppositely placed porous electrodes, in front of which ion-exchange membranes are positioned. Due to the applied potential, ions ar

  12. Steerable Capacitive Proximity Sensor

    Science.gov (United States)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Steerable capacitive proximity sensor of "capaciflector" type based partly on sensing units described in GSC-13377 and GSC-13475. Position of maximum sensitivity adjusted without moving sensor. Voltage of each driven shield adjusted separately to concentrate sensing electric field more toward one side or other.

  13. Enhanced ant colony optimization for inventory routing problem

    Science.gov (United States)

    Wong, Lily; Moin, Noor Hasnah

    2015-10-01

    The inventory routing problem (IRP) integrates and coordinates two important components of supply chain management which are transportation and inventory management. We consider a one-to-many IRP network for a finite planning horizon. The demand for each product is deterministic and time varying as well as a fleet of capacitated homogeneous vehicles, housed at a depot/warehouse, delivers the products from the warehouse to meet the demand specified by the customers in each period. The inventory holding cost is product specific and is incurred at the customer sites. The objective is to determine the amount of inventory and to construct a delivery routing that minimizes both the total transportation and inventory holding cost while ensuring each customer's demand is met over the planning horizon. The problem is formulated as a mixed integer programming problem and is solved using CPLEX 12.4 to get the lower and upper bound (best integer) for each instance considered. We propose an enhanced ant colony optimization (ACO) to solve the problem and the built route is improved by using local search. The computational experiments demonstrating the effectiveness of our approach is presented.

  14. Real-time immune-inspired optimum state-of-charge trajectory estimation using upcoming route information preview and neural networks for plug-in hybrid electric vehicles fuel economy

    Science.gov (United States)

    Mozaffari, Ahmad; Vajedi, Mahyar; Azad, Nasser L.

    2015-06-01

    The main proposition of the current investigation is to develop a computational intelligence-based framework which can be used for the real-time estimation of optimum battery state-of-charge (SOC) trajectory in plug-in hybrid electric vehicles (PHEVs). The estimated SOC trajectory can be then employed for an intelligent power management to significantly improve the fuel economy of the vehicle. The devised intelligent SOC trajectory builder takes advantage of the upcoming route information preview to achieve the lowest possible total cost of electricity and fossil fuel. To reduce the complexity of real-time optimization, the authors propose an immune system-based clustering approach which allows categorizing the route information into a predefined number of segments. The intelligent real-time optimizer is also inspired on the basis of interactions in biological immune systems, and is called artificial immune algorithm (AIA). The objective function of the optimizer is derived from a computationally efficient artificial neural network (ANN) which is trained by a database obtained from a high-fidelity model of the vehicle built in the Autonomie software. The simulation results demonstrate that the integration of immune inspired clustering tool, AIA and ANN, will result in a powerful framework which can generate a near global optimum SOC trajectory for the baseline vehicle, that is, the Toyota Prius PHEV. The outcomes of the current investigation prove that by taking advantage of intelligent approaches, it is possible to design a computationally efficient and powerful SOC trajectory builder for the intelligent power management of PHEVs.

  15. On line routing per mobile phone

    DEFF Research Database (Denmark)

    Bieding, Thomas; Görtz, Simon; Klose, Andreas

    2009-01-01

    On-line routing is concerned with building vehicle routes in an ongoing fashion in such a way that customer requests arriving dynamically in time are efficiently and effectively served. An indispensable prerequisite for applying on-line routing methods is mobile communication technology. Addition...

  16. Optimal Routing of Cigarette Delivery Vehicle Based on Genetic Algorithm%基于遗传算法的烟草配送车路径优化问题

    Institute of Scientific and Technical Information of China (English)

    叶安新

    2011-01-01

    On the basis of establishing an optimized model for optimal routing of cigarette delivery vehicle problem, the paper uses techniques such as roulette wheel selection, partially matched crossover and self adaptation for fitness function, designs a genotic algorithm based on natural numbers. At the end of the paper make some experimental calculations using this algorithm. The experimental calculations results demonstrate that the optimal or nearly optimal solutions to the Cigarette Delivery Vehicle routing problem can be easily obtained by using genetic algorithm.%在建立烟草配送车路径优化问题模型的基础上,采用轮盘赌复制法、部分匹配交叉算法、和适应度函数自适应调整等技术,设计了基于自然数编码的遗传算法,最后以这种方法进行了实验计算,通过计算结果表明,用遗传算法进行烟草车配送路径优化,可以方便有效地求得问题的最优解或近似最优解.

  17. Induced Charge Capacitive Deionization

    CERN Document Server

    Rubin, S; Biesheuvel, P M; Bercovici, M

    2016-01-01

    We demonstrate the phenomenon of induced-charge capacitive deionization (ICCDI) that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electrostatic field. The external electric field induces an electric dipole in the porous particle, leading to capacitive charging of its volume by both cations and anions at opposite poles. This regime is characterized both by a large RC charging time and a small electrochemical charge relaxation time, which leads to rapid and significant deionization of ionic species from a volume which is on the scale of the particle. We show by theory and experiment that the transient response around a cylindrical particle results in spatially non-uniform charging and non-steady growth of depletion regions which emerge around the particle's poles. Potentially, ICCDI can be useful in applications where fast concentration changes of ionic species are required over large volumes.

  18. Time-dependent Single Vehicle Routing Problem and Dynamic Programming Algorithm with Greed Dispatching Restriction%时变单车路径优化模型及动态规划算法

    Institute of Scientific and Technical Information of China (English)

    彭勇; 殷树才

    2014-01-01

    车辆路径问题由于其广泛的应用领域及经济价值而成为学术研究热点。然而,在已有的研究文献中,车辆的速度时变与服务多任务特性很少被关注。本文讨论了具有这两个特性的单车路径优化问题。建立了以送货完成时间最早为优化目标的时变单车送货路径优化模型。由于很难获得该模型的精确解,本文提出了一种贪婪补货策略压缩原问题解空间,设计动态规划算法给出了车辆行驶时间满足FIFO规则的送货顺序近似最优解。数值算例验证了该算法所得到的解仅是原问题的近似最优解这一结论。算例同时表明优化配送时间随着车辆装载能力的增大而缩短,并在车辆装载能力超过所有客户配送总需求时实现最短配送时间,即,使用较大装载能力车辆能节约更多配送时间。%Vehicle routing problems have been extensively studied due to its extensive application and great value on economy.However, two constraints receive less attention , i.e., vehicle speed will be changed with time , and vehicle can service more than one trip .This paper discusses single vehicle routing problem with these two constraints .A mathematic model the optimal object of which is to find the route schedule which has the earliest task completion time is established .It's hard to achieve exact solutions of the problem .So the paper proposes a greed dispatching strategy for the model to compress solution space , and provides a dynamic programming algo-rithm with FIFO rule .The numerical examples demonstrate that for our model , the solution provided by dynamic programming algorithm is only a satisfactory solution .The numerical examples also indicate the optimal dispatc-hing time decreases while the vehicle load capacity increases , and it gets the minimum when the vehicle load ca-pacity is larger than customers total demand .That is, using larger capacity vehicle will save more dispatching

  19. Design of Capacitance to Voltage Converter for Capacitive Sensor Transducer

    Directory of Open Access Journals (Sweden)

    A. H.M.Z. Alam

    2010-01-01

    Full Text Available Problem statement: The design of Capacitance to Voltage Converter (CVC for capacitive sensor transducer was presented. The proposed design will reduce the size, power consumption and supply voltage of the circuit and can be used in high frequency band transducer. Approach: The design was implemented using the Operational amplifier (Op amp and capacitive network. The circuit was simulated using the PSPICE model parameters based on standard 0.13 μm CMOS process. Results: The design was able to measure a wide range of capacitance variations for the capacitive transducer. The performance analysis of the design showed desirable performance parameters in terms of response, low power consumption and a linear output voltage within the wide range of capacitive transducer capacitance variation for the power supply voltage of 1.2 V was achieved. Conclusion/Recommendations: The output voltage of the circuit varied linearly with the variation of capacitive transducer capacitance variation. The improved converter was compact and robust for integration into capacitive measuring systems and suitable for use in environment that making use of higher frequency band.

  20. Molecular Aspects of Capacitation

    OpenAIRE

    Gulfidan Zulfikaroglu; Hulya Ozgur; Sait Polaturkey

    2010-01-01

    Male and female gamets are derived from the primordial germ cells, which migrate from the wall of the yolk sac toward the developing gonads. Following a series of mitotic divisions these cells increase in number at the gonads. The primordial germ cells differentiate into spermatogonia and take the form of mature spermatozoa after spermotogensis and spermotogenesis at puberty. Capacitation is the reaction, which includes all of the molecular and physiological events of mature sperm to gain the...

  1. Route Planning for Unmanned Aerial Vehicles Based on the Particle Swarm Optimization%基于粒子群优化算法的无人机航迹规划

    Institute of Scientific and Technical Information of China (English)

    陈小双; 翟为刚; 赵万里

    2011-01-01

    Presents a route planning for Unmanned Aerial Vehicles (UAV) based on the Particle Swarm Optimization(PSO). Introduces the PSO to establish a single-object UAV route planning on the equivalent digital map. And analyses the PSO in details. The simulation experiment result demonstrates that this method can complete planning mission efficiently and obtain a desirable three-dimensional route.%提出一种基于粒子群优化算法的无人机航迹规划方法,利用粒子群优化算法,在等效数字地图中实现单个目标点的无人机航迹规划,并对算法性能进行仔细分析,仿真结果表明,该方法能够快速有效地完成航迹规划任务.得到满意的三维航迹。

  2. Electrical capacitance clearanceometer

    Science.gov (United States)

    Hester, Norbert J. (Inventor); Hornbeck, Charles E. (Inventor); Young, Joseph C. (Inventor)

    1992-01-01

    A hot gas turbine engine capacitive probe clearanceometer is employed to measure the clearance gap or distance between blade tips on a rotor wheel and its confining casing under operating conditions. A braze sealed tip of the probe carries a capacitor electrode which is electrically connected to an electrical inductor within the probe which is inserted into a turbine casing to position its electrode at the inner surface of the casing. Electrical power is supplied through a voltage controlled variable frequency oscillator having a tuned circuit in which the probe is a component. The oscillator signal is modulated by a change in electrical capacitance between the probe electrode and a passing blade tip surface while an automatic feedback correction circuit corrects oscillator signal drift. A change in distance between a blade tip and the probe electrode is a change in capacitance therebetween which frequency modulates the oscillator signal. The modulated oscillator signal which is then processed through a phase detector and related circuitry to provide an electrical signal is proportional to the clearance gap.

  3. A Model and Algorithm to Solve Vehicle Routing Problem with Split Delivery%需求可分的车辆路径问题模型与算法

    Institute of Scientific and Technical Information of China (English)

    谢秉磊; 胡小明; 张一喆

    2012-01-01

    需求可分的车辆路径问题(SDVRP)无论是从运输距离还是派车数量上,都可进一步优化传统的车辆路径问题.为了降低SDVRP的求解难度,本文在分析最优解性质的基础上,加强模型的约束条件,将原模型转变为等价的改进SDVRP,并在使用蚂蚁算法求解改进SDVRP模型的过程中,采用开发新路径和2-opt相结合的方法,以避免出现迭代停滞的现象.实验表明,算法计算结果稳定,最差解与最好解的偏差仅为1.80%.%Vehicle routing model with split delivery( SDVRP) can optimize further traditional vehicle routing problem in both transportation distance and the number of dispatching vehicle. To reduce the difficulty with the solution to SDVRP, based on analyzing properties of the optimal solution, the original model is transformed to the e-quivalent modified SDVRP through enforcing constraints of the original model. In the process of solving the modified SDVRP model with ant colony algorithm, exploring new routes and 2-opt are combined to avoid premature convergence. The experiments demonstrate that the computing results are stable: The bias between the worst solution and the best solution is only 1.80%.

  4. Capacitance of circular patch resonator

    Energy Technology Data Exchange (ETDEWEB)

    Miano, G.; Verolino, L. [Dip. di Ingegneria Elettrica, Ist. Nazionale di Fisica Nucleare, Naples (Italy); Panariello, G. [Dip. di Ingegneria Elettronica, Naples (Italy); Vaccaro, V.G. [Ist. Nazionale di Fisica Nucleare, Naples (Italy). Dipt. di Scienze Fisiche

    1995-11-01

    In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants.

  5. 求解带时间窗车辆路径问题的混合智能算法%Hybrid intelligent algorithm for vehicle routing problem with time windows

    Institute of Scientific and Technical Information of China (English)

    孙小军

    2015-01-01

    Based on cuckoo search algorithm and partheno-genetic algorithm,a hybrid intelligent algorithm is designed to solve the vehicle routing problem with time windows.Firstly,this algorithm analyzes the locations of customers by clustering method,and then,forms the optimal route for the divided areas.This hybrid intelligent algorithm not only improves the operation of the cuckoo search algorithm,which is to randomly change the whole location of the cuckoo nest when the cuckoo eggs are found by the nest's master,but also accelerates the search speed of optimal delivery route by using partheno-genetic algorithm.In addition,the computational complexities of this hybrid intelligent algorithm and cuckoo search algorithm are analyzed and compared.Finally,according to test results under ISO standard test collection-Benchmark Problems,it is verified that this hybrid intelligent algorithm is an effective method in solving the vehicle routing problem with time windows.%基于布谷鸟搜索算法和单亲遗传算法,设计了一种求解带时间窗车辆路径问题的混合智能算法。该算法首先对客户位置进行聚类分析,然后再进行各区域的路径优化。混合智能算法不仅改进了布谷鸟搜索算法中当鸟卵被鸟窝主人发现后需要随机改变整个鸟窝位置的操作,同时引入的单亲遗传算法加快了最优配送路线的搜索速度。分析和比较了混合智能算法与布谷鸟搜索算法的计算复杂度。最后采用国际通用标准测试集 Benchmark Problems 进行测试。结果显示,混合智能算法是求解带时间窗车辆路径问题的一种有效算法。

  6. Improved Capacitive Liquid Sensor

    Science.gov (United States)

    Waldman, Francis A.

    1992-01-01

    Improved capacitive sensor used to detect presence and/or measure thickness of layer of liquid. Electrical impedance or admittance of sensor measured at prescribed frequency, and thickness of liquid inferred from predetermined theoretical or experimental relationship between impedance and thickness. Sensor is basically a three-terminal device. Features interdigitated driving and sensing electrodes and peripheral coplanar ground electrode that reduces parasitic effects. Patent-pending because first to utilize ground plane as "shunting" electrode. System less expensive than infrared, microwave, or refractive-index systems. Sensor successfully evaluated in commercial production plants to characterize emulsions, slurries, and solutions.

  7. Izbor optimalnog puta za kretanje organizovanog kolonskog saobraćajnog toka na osnovu rezultata modeliranja / Choosing an optimal route for organized vehicle movement based on modeling results

    Directory of Open Access Journals (Sweden)

    Radomir S. Gordić

    2006-04-01

    Full Text Available U toku planiranja i praktične realizacije zadataka jedinica Vojske SCG često se javlja problem izbora optimalnog puta između dva mesta (čvora na putnoj mreži. Kriterijumi optimizacije mogu biti različiti. Ovaj projekat treba da omogući brzo i lako određivanje optimalnog puta, primenom dinamičkog programiranja (DP, uz korišćenje Belmanovog (Bellman, algoritma u zavisnosti od izabranog kriterijuma -parametra. Kriterijum optimizacije je minimalno vreme kretanja (putovanja, koje je dobijeno imitacionim modeliranjem kolonskog saobraćajnog toka. Razrađeni algoritam omogućuje izbor optimalnog puta, za bilo koja dva čvora na mreži. / During the planning and practical realization of Serbian & Montenegro units' tasks a problem -which often occurs is choosing an optimal transport route between two places (nodes. Optimization criteria can be various. This project should enable quick and easy defining of an optimal route, applying dynamic programing (DP using Bellman's algorithm depending on chosen criteria - parameter. Optimization criteria represent minimum movement time (traveling, which are taken from imitational modeling of a traffics queue flow. Operating algorithm enable choosing an optimal transport route, for any two nodes on a road map.

  8. A location-routing problem model with multiple periods and fuzzy demands

    Directory of Open Access Journals (Sweden)

    Ali Nadizadeh

    2014-08-01

    Full Text Available This paper puts forward a dynamic capacitated location-routing problem with fuzzy demands (DCLRP-FD. It is given on input a set of identical vehicles (each having a capacity, a fixed cost and availability level, a set of depots with restricted capacities and opening costs, a set of customers with fuzzy demands, and a planning horizon with multiple periods. The problem consists of determining the depots to be opened only in the first period of the planning horizon, the customers and the vehicles to be assigned to each opened depot, and performing the routes that may be changed in each time period due to fuzzy demands. A fuzzy chance-constrained programming (FCCP model has been designed using credibility theory and a hybrid heuristic algorithm with four phases is presented in order to solve the problem. To obtain the best value of the fuzzy parameters of the model and show the influence of the availability level of vehicles on final solution, some computational experiments are carried out. The validity of the model is then evaluated in contrast with CLRP-FD's models in the literature. The results indicate that the model and the proposed algorithm are robust and could be used in real world problems.

  9. Programmable electronic synthesized capacitance

    Science.gov (United States)

    Kleinberg, Leonard L. (Inventor)

    1987-01-01

    A predetermined and variable synthesized capacitance which may be incorporated into the resonant portion of an electronic oscillator for the purpose of tuning the oscillator comprises a programmable operational amplifier circuit. The operational amplifier circuit has its output connected to its inverting input, in a follower configuration, by a network which is low impedance at the operational frequency of the circuit. The output of the operational amplifier is also connected to the noninverting input by a capacitor. The noninverting input appears as a synthesized capacitance which may be varied with a variation in gain-bandwidth product of the operational amplifier circuit. The gain-bandwidth product may, in turn, be varied with a variation in input set current with a digital to analog converter whose output is varied with a command word. The output impedance of the circuit may also be varied by the output set current. This circuit may provide very small ranges in oscillator frequency with relatively large control voltages unaffected by noise.

  10. A novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances

    Institute of Scientific and Technical Information of China (English)

    Dong Linxi; Chen Jindan; Yan Haixia; Huo Weihong; Li Yongjie; Sun Lingling

    2009-01-01

    The comb capacitances fabricated by deep reactive ion etching (RIE) process have high aspect ratio which is usually smaller than 30 : 1 for the complicated process factors, and the combs are usually not parallel due to the well-known micro-loading effect and other process factors, which restricts the increase of the seismic mass by increasing the thickness of comb to reduce the thermal mechanical noise and the decrease of the gap of the comb capacitances for increasing the sensitive capacitance to reduce the electrical noise. Aiming at the disadvantage of the deep RIE, a novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances is developed. One part of sensing of inertial signal of the micro-accelerometer is by the grid strip capacitances whose overlapping area is variable and which do not have the non-parallel plate's effect caused by the deep RIE process. Another part is by the sensing gap alterable capacitances whose gap between combs can be reduced by the actuators. The designed initial gap of the alterable comb capacitances is relatively large to depress the effect of the maximum aspect ratio (30 : 1) of deep RIE process. The initial gap of the capacitance of the actuator is smaller than the one of the comb capacitances. The difference between the two gaps is the initial gap of the sensitive capacitor. The designed structure depresses greatly the requirement of deep RIE process. The effects of non-parallel combs on the accelerometer are also analyzed. The characteristics of the micro-accelerometer are discussed by field emission microscopy (FEM) tool ANSYS. The tested devices based on slide-film damping effect are fabricated, and the tested quality factor is 514, which shows that grid strip capacitance design can partly improve the resolution and also prove the feasibility of the designed silicon-glass anodically bonding process.

  11. Application of Bat Algorithm in Vehicle Routing Problem of Logistics Distribution%蝙蝠算法在物流配送车辆路径优化问题中的应用

    Institute of Scientific and Technical Information of China (English)

    马祥丽; 张惠珍; 马良

    2015-01-01

    车辆路径问题(Vehicle Routing Problem,VRP)是组合优化问题中一个典型的NP难题.蝙蝠算法(Bat Algorithm,BA)是一种新型的智能优化算法,尚未被应用到求解VRP问题中去.根据物流配送中VRP问题的数学模型及其具体特征,设计了求解VRP问题的蝙蝠算法,并通过仿真实例和与其他算法进行比较的方式验证了蝙蝠算法求解VRP问题的有效性与可行性.

  12. A Genetic Algorithm on Inventory Routing Problem

    Directory of Open Access Journals (Sweden)

    Nevin Aydın

    2014-03-01

    Full Text Available Inventory routing problem can be defined as forming the routes to serve to the retailers from the manufacturer, deciding on the quantity of the shipment to the retailers and deciding on the timing of the replenishments. The difference of inventory routing problems from vehicle routing problems is the consideration of the inventory positions of retailers and supplier, and making the decision accordingly. Inventory routing problems are complex in nature and they can be solved either theoretically or using a heuristics method. Metaheuristics is an emerging class of heuristics that can be applied to combinatorial optimization problems. In this paper, we provide the relationship between vendor-managed inventory and inventory routing problem. The proposed genetic for solving vehicle routing problem is described in detail.

  13. Bat algorithm for vehicle routing problem of logistics distribution with time windows%带时间窗物流配送车辆路径问题的蝙蝠算法

    Institute of Scientific and Technical Information of China (English)

    马祥丽; 张惠珍; 马良

    2016-01-01

    Vehicle Routing Problem with Time Windows(VRPTW)is an important and practical research project, which adds the time constraints into the mathematical model based on the capacity constraints with requirements of the lowest total cost in distribution system. Bat Algorithm(BA)is a new intelligent optimization algorithm, which has not yet been applied to VRPTW. Based on the mathematical model and specific features of VRPTW, this paper redesigns the operators of BA and proposes an improved bat algorithm for solving it. Furthermore, the results show that bat algorithm can effec-tively and feasibly solve VRPTW in logistics distribution through simulation examples and comparisons with other algo-rithms. The research results also expand the application field of BA.%带时间窗车辆路径问题(Vehicle Routing Problem with Time Windows,VRPTW)是一个重要而实际的研究课题,该问题在有能力约束模型的基础上增加了时间约束,要求配送系统总费用最低.蝙蝠算法(Bat Algorithm,BA)是一种新型的智能优化算法,目前尚未被应用到求解VRPTW问题中.根据VRPTW问题的数学模型及其具体特征,重新设计了BA的操作算子,给出了求解VRPTW问题的改进蝙蝠算法,并通过仿真实例和与其他算法进行比较的方式,验证了蝙蝠算法在VRPTW问题中的求解性能,拓展了蝙蝠算法的应用领域.

  14. 同时送取货车辆路径问题算法研究综述%Algorithm review of vehicle routing problem with simultaneous delivery and pickup

    Institute of Scientific and Technical Information of China (English)

    王科峰; 叶春明; 李永林

    2013-01-01

    针对同时送取货车辆路径问题的研究算法进行了评述.将该问题的求解方法分为精确算法、构造型启发式、现代启发式以及并行算法四个大类.从算法的原理、性能、适用环境,以及算法之间差异性等方面对各类算法进行了较为全面的介绍.最后,说明了VRPSDP算法研究在节点具有双重需求车辆路径问题理论研究方面的意义,并提出未来VRPSDP算法研究的两个发展方向,即适合多处理器上运行的并行现代启发式算法,以及有效的混合算法如量子行为粒子群算法.%This paper gave a review about the algorithms for the vehicle routing problem with simultaneous delivery and pickup (VRPSDP). It divided the solving methods into four main classes; exact algorithm, constructive heuristics algorithm, meta-heuristics algorithm, and parallel algorithm. It also gave the detail introductions of the algorithms from the principle, performance, application environment, and the differences between them. In the end, it introduced the significance of the algorithm research of VRPSDP in the theory development of the vehicle routing problem with node having double demands. After that, it proposed two research directions in the future, which were parallel metaheuristics based on multiple processors, and the effec-tive hybrid algorithm such as quantum-behaved particle swarm optimization.

  15. Simultaneous delivery and pickup vehicle routing problem with three-dimension ;loading constraints%同时取送货的三维装载约束下车辆路径问题

    Institute of Scientific and Technical Information of China (English)

    彭碧涛; 周世平

    2016-01-01

    同时取货和送货的三维装载约束下车辆路径问题(3L-VRPSDP)是经典车辆路径问题(VRP)的一个扩展,在3L-VRPSDP中,顾客可能要求同时取货和送货,而且货物装载要考虑其三维大小、先进后出、底面支撑等装载特性。针对这类问题,提出了基于左底优先和最大接触面优先的装载算法,在装载时要考虑其配送特征;在此基础上,设计了对应的禁忌搜索算法对初始结果进行优化,通过实验验证了算法的有效性。%The Simultaneous Delivery and Pickup Vehicle Routing Problem with Three-Dimension Loading Constraints (3L-VRPSDP)is a variant of the classical Vehicle Routing Problem(VRP)where clients may require simultaneous pickups and deliveries, at the same time, cargo must consider its three dimensional size, first in last out, bottom support constraints. Considering the distribution characteristics, the loading algorithms based on Left Bottom(LB)and Maximum Contact Area (MCA)are proposed, and the corresponding tabu search algorithms are designed. Experiments are given to prove the validity of the algorithms.

  16. 求解多车场累积时间车辆路径问题的Memetic算法%A Memetic Algorithm for Solving Multi-depot Cumulative Capacitated Vehicle Routing Problem

    Institute of Scientific and Technical Information of China (English)

    刘竹馨; 许维胜; 曾正洋

    2014-01-01

    在应急救援车辆路径优化问题中,为了及时救援,缩短所有受灾点的总等待时间,提出了多车辆车场累积时间车辆路径问题.它是多个车场通过多个运输车队,使所有受灾点等待时间总和最短的运输问题.针对该NP难问题提出了一种Memetic算法求解.先用改进的最优切割算法MDVRP-Split将受灾点分配至各车场,通过选择、交叉及局部搜索得到最优路径.标准算例的测试结果表明,提出的算法注重了求解质量与求解效率的平衡.

  17. Optimal pricing of capacitated networks

    NARCIS (Netherlands)

    Grigoriev, Alexander; Loon, van Joyce; Sitters, René; Uetz, Marc

    2009-01-01

    We address the algorithmic complexity of a profit maximization problem in capacitated, undirected networks. We are asked to price a set of $m$ capacitated network links to serve a set of $n$ potential customers. Each customer is interested in purchasing a network connection that is specified by a si

  18. The Service-Time Restricted Capacitated Arc Routing Problem

    DEFF Research Database (Denmark)

    Lystlund, Lise; Wøhlk, Sanne

    We consider an inventory system, operated by a base stock policy and serving two customer classes. One customer class, Class 1, does not provide any advance demand information at all, while the other, Class 2, does. In order to reward a customer of Class 2 for providing advance order information...

  19. Ferry Routes, This data set contains established commercial passenger and vehicle water ferry routes for Rhode Island ports and ferry docks. This data set was created for the general mapping for transporation planning. Ferry route Centerlines were originally digitized, Published in 2004, 1:4800 (1in=400ft) scale, State of Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Ferry Routes dataset, published at 1:4800 (1in=400ft) scale, was produced all or in part from Other information as of 2004. It is described as 'This data set...

  20. 带工作时间与时间窗的开放式车辆路径问题%Open Vehicle Routing Problem with Working Time and Time Windows

    Institute of Scientific and Technical Information of China (English)

    潘立军; 符卓; 刘喜梅

    2012-01-01

    在BtoC电子商务物流配送活动中,配送公司外包车辆和配送人员上班具有时间限制.为求解带工作时间与时间窗约束的开放式车辆路径问题(OVRPTWWT),构建其混合整数规划模型,给出一种求解该问题的非代际克隆选择算法,对算法中抗体的更新与抑制策略进行改进,设计出新的克隆选择方法.通过实验验证了该模型与OVRPTWWT非代际克隆选择算法的有效性.%In BtoC e-commerce logistics distribution activities, many distribution companies using outsourcing vehicles and the drivers have working time limit. On the basis of this, this paper proposes an Open Vehicle Routing Problem with Time Windows and Working Time (OVRPTWWT), and constructs its mixed integer planning model. A clonal selection algorithm for OVRPTWWT is proposed, it improves the antibodies updating procedure, restraining tactics and designs a new clonal selection method for the algorithm. An example verifies the efficiency of the model and algorithm.

  1. Bee colony optimization algorithm for split delivery vehicle routing problem%需求可拆分车辆路径问题的蜂群优化算法

    Institute of Scientific and Technical Information of China (English)

    汪婷婷; 倪郁东; 何文玲

    2014-01-01

    In this paper ,the split delivery vehicle routing problem is researched and the mathematical optimization model w hich seeks the shortest distance to meet the delivery requirements is constructed . T he model releases the constraint that only one vehicle can be used to meet the delivery requirement for one customer .A new bee colony optimization(BCO) algorithm is proposed based on the improve-ment of the reaction threshold and the value of stimulatory signal .The experimental result proves the feasibility of the algorithm ,and also highlights the strong optimization ability of BCO algorithm by comparison with other typical algorithms .%文章研究了需求可拆分的车辆路径问题,通过解除传统车辆路径问题中每个任务点需求只能由1辆车满足的约束,建立了寻求满足配送要求最短行驶距离的数学优化模型,在改进反应阈值和刺激信号值的基础上提出了一种新型蜂群优化算法。仿真实验结果验证了算法的可行性,并通过与其他典型算法对比凸显了该算法较强的寻优能力。

  2. Research on heterogeneous fixed fleet vehicle routing problem with pick-up and delivering%多车型集配货一体化车辆路径问题研究

    Institute of Scientific and Technical Information of China (English)

    陈妍; 单汨源; 王秋凤

    2015-01-01

    Considering that heterogeneous fixed fleet vehicle routing problem with pickups and deliveries (HFFVRPPD) in logistics distribution is a widespread NP problem, which is more complex than single/multi vehicle with one way routing problem, HFFVRPPD optimization model was established to improve the load rate of vehicle, and reduce travel times. The algorithm of producing initial feasible solutions of the model was constructed, the improved simulated annealing algorithm was designed, which includes the operation of multi operators neighborhood based on the probability, embedding of memory devices, and the termination of many standard ways. The multi vehicle routing with one way problem and HFFVRPPD were compared to verify the effectiveness of the model and algorithm. The results show that the improved simulated annealing algorithm solving the HFFVRPPD is more convenient, and the HFFVRPPD optimization can effectively reduce the distribution costs.%针对客户存在收货和发货双重需求的物流配送问题,讨论具有多种车型的集配货一体化车辆路径问题。在综合考虑各车型的固定成本和可变配送成本的前提下,以总成本最小为目标,以尽可能提高车辆满载率、减少出行次数为思路,构建多车型集配货一体化车辆路径优化模型。基于最小插入费用法设计初始可行解生成算法,通过引入基于概率的多算子邻域操作、最优解记忆装置、多准则终止原则对模拟退火算法进行改进,给出求解思路。设计算例并对多车型单/双向集配货模型的求解结果进行比较,以验证模型的实用性和算法的有效性。研究结果表明:使用改进后的模拟退火算法对构建的多车型集配货一体化车辆路径问题模型求解更直接简便,对多车型集配货一体化车辆路径优化后能有效降低配送成本。

  3. Metaheuristics for multi products inventory routing problem with time varying demand

    Science.gov (United States)

    Moin, Noor Hasnah; Ab Halim, Huda Zuhrah; Yuliana, Titi

    2014-07-01

    This paper addresses the inventory routing problem (IRP) with a many-to-one distribution network, consisting of a single depot, an assembly plant, and geographically dispersed suppliers where a capacitated homogeneous vehicle delivers a distinct product from the suppliers to fulfill the demand specified by the assembly plant over the planning horizon. The inventory holding cost is assumed to be product specific and only incurred at the assembly plant. Two metaheuristics comprise of artificial bee colony (ABC) and scatter search (SS) algorithms are proposed to solve the problem. Computational testing on instances which represents small, medium, and large data sets show that the ABC algorithm performs slightly better when compared the SS overall except for fifty suppliers problems.

  4. 陕西省电动汽车动力电池产业发展技术路线研究%The Research onTechnicalRoute of Battery forElectric Vehicle in Shaanxi Province

    Institute of Scientific and Technical Information of China (English)

    贺伊琳; 苏楠; 鹿静; 王栋梁

    2016-01-01

    With the development of industrialization, there appears a significant increase in the number of cars, followed by environmental pollution and energy shortage, Electric car isenvironmentally friendlyand will not have pressure on oil, and then it have become a hot spot in today. The battery is the core technology of electric vehicles, the development of power battery directly affects the development of electric vehicles. Therefore, improving the technological level of battery power is important to promote the development of electric vehicle. Thispaper discusses the status of the development of battery powerat home and abroad and makes an compare of some types of batteries. Shanxi provincepower battery industry is introduced based on SWOT.Finally, studying the Shanxi Province technical route of electric vehicle battery development with its status, clearing development objectives, proposing key technology and exploring important spot,thiswill havegreat theoretical significance and guidance on future development of battery technology in Shanxi Province.%随着工业化进展,汽车数量大幅增加,随之而来的是环境污染和能源危机,电动汽车绿色环保,且不会对石油能源造成压力,已成为当今世界研究的热点。动力电池是电动汽车的核心技术之一,其发展直接影响电动汽车的性能,因此,提高动力电池的技术水平对促进电动汽车技术的进步具有重要意义。文章首先论述国内外动力电池的发展现状,对每种电池的性能进行比较,其次基于 SWOT 理论对目前陕西省动力电池产业进行分析,最后结合陕西省现状对该省电动汽车动力电池发展的技术路线进行研究,明确发展目标,提出关键技术与研发重点内容,对陕西省动力电池技术今后的发展具有重要理论意义与指导作用。

  5. Large capacitance enhancement induced by metal-doping in graphene-based supercapacitors: a first-principles-based assessment.

    Science.gov (United States)

    Paek, Eunsu; Pak, Alexander J; Hwang, Gyeong S

    2014-08-13

    Chemically doped graphene-based materials have recently been explored as a means to improve the performance of supercapacitors. In this work, we investigate the effects of 3d transition metals bound to vacancy sites in graphene with [BMIM][PF6] ionic liquid on the interfacial capacitance; these results are compared to the pristine graphene case with particular attention to the relative contributions of the quantum and electric double layer capacitances. Our study highlights that the presence of metal-vacancy complexes significantly increases the availability of electronic states near the charge neutrality point, thereby enhancing the quantum capacitance drastically. In addition, the use of metal-doped graphene electrodes is found to only marginally influence the microstructure and capacitance of the electric double layer. Our findings indicate that metal-doping of graphene-like electrodes can be a promising route toward increasing the interfacial capacitance of electrochemical double layer capacitors, primarily by enhancing the quantum capacitance. PMID:24983127

  6. Capacitive deionization system

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, J. H., LLNL

    1996-10-01

    The new capacitive deionization system (CDI) removes ions, contaminants impurities from water and other aqueous process streams, and further selectively places the removed ions back into solution during regeneration. It provides a separation process that does not utilize chemical regeneration processes, and thus significantly reduces or completely eliminates secondary wastes associated with the operation of ion exchange resins. In the CDI, electrolyte flows in open channels formed between adjacent electrodes, and consequently the pressure drop is much lower than conventional separation processes. The fluid flow can be gravity fed through these open channels, and does not require membranes. This feature represents a significant advantage over the conventional reverse osmosis systems which include water permeable cellulose acetate membranes, and over the electrodialysis systems which require expensive and exotic ion exchange membranes. The CDI is adaptable for use in a wide variety of commercial applications, including domestic water softening, industrial water softening, waste water purification, sea water desalination, treatment of nuclear and aqueous wastes, treatment of boiler water in nuclear and fossil power plants, production of high-purity water for semiconductor processing, and removal of salt from water for agricultural irrigation. CDI accomplishes this removal of impurities by a variety of mechanisms, but predominantly by electrostatic removal of organic and inorganic ions from water or any other dielectric solvent.

  7. Capacitance probe for detection of anomalies in non-metallic plastic pipe

    Science.gov (United States)

    Mathur, Mahendra P.; Spenik, James L.; Condon, Christopher M.; Anderson, Rodney; Driscoll, Daniel J.; Fincham, Jr., William L.; Monazam, Esmail R.

    2010-11-23

    The disclosure relates to analysis of materials using a capacitive sensor to detect anomalies through comparison of measured capacitances. The capacitive sensor is used in conjunction with a capacitance measurement device, a location device, and a processor in order to generate a capacitance versus location output which may be inspected for the detection and localization of anomalies within the material under test. The components may be carried as payload on an inspection vehicle which may traverse through a pipe interior, allowing evaluation of nonmetallic or plastic pipes when the piping exterior is not accessible. In an embodiment, supporting components are solid-state devices powered by a low voltage on-board power supply, providing for use in environments where voltage levels may be restricted.

  8. Efficiency of Capacitively Loaded Converters

    DEFF Research Database (Denmark)

    Andersen, Thomas; Huang, Lina; Andersen, Michael A. E.;

    2012-01-01

    is introduced as a definition of efficiency. The calculated and measured efficiency curves for charging DEAP actuator, polypropylene film capacitor and X7R MLCC are provided and compared. The attention has to be paid for the voltage dependent capacitive load, like X7R MLCC, when evaluating the charging......This paper explores the characteristic of capacitance versus voltage for dielectric electro active polymer (DEAP) actuator, 2kV polypropylene film capacitor as well as 3kV X7R multi layer ceramic capacitor (MLCC) at the beginning. An energy efficiency for capacitively loaded converters...... efficiency of converter. Based on the capacitancevoltage curve, the correct capacitance should be chosen when calculating the stored energy; otherwise misleading optimistic efficiency can always be obtained. Actually, when DEAP actuator is not available at the early developing stage, the voltage independent...

  9. Capacitive Position Sensor For Accelerometer

    Science.gov (United States)

    Vanzandt, Thomas R.; Kaiser, William J.; Kenny, Thomas W.

    1995-01-01

    Capacitive position sensor measures displacement of proof mass in prototype accelerometer described in "Single-Crystal Springs for Accelerometers" (NPO-18795). Sensor is ultrasensitive, miniature device operating at ultra-high frequency and described in more detail in "Ultra-High-Frequency Capacitive Displacement Sensor," (NPO-18675). Advances in design and fabrication of prototype accelerometer also applicable to magnetometers and other sensors in which sensed quantities measured in terms of deflections of small springs.

  10. The concept of chemical capacitance, A critique.

    OpenAIRE

    Trissl, H. W.

    1981-01-01

    The concept of chemical capacitance as introduced by Hong and Mauzerall (Proc. Natl. Acad. Sci. U.S.A. 1974. 71:1564) is critically reexamined. This novel capacitance was introduced to explain the time-course of flash-induced photocurrents observed in lipid bilayer membranes containing porphyrins. According to Hong and Mauzerall, the chemical capacitance results from a combination of three fundamental capacitances: the geometric membrane capacitance and the two interfacial double layer capaci...

  11. Memoire : Public consultation on off road vehicles: Recommendations for reducing pollution and greenhouse gases associated with off road vehicle activities in Quebec; Memoire : Consultation publique sur les vehicules hors route : Recommandations pour la reduction de la pollution et des gaz a effet de serre lies aux activites de vehicules hors route au Quebec

    Energy Technology Data Exchange (ETDEWEB)

    Belisle, A.; Castonguay, M. [Association quebecoise de lutte contre la pollution atmospherique, Saint-Leon-de-Standon, Quebec (Canada)

    2005-06-01

    Recreational or off-road vehicles (ORV) such as snowmobiles, cross-country vehicles and dirt bikes emit significant levels of exhaust gases, thus contributing to air pollution. The Association quebecoise de lutte contre la pollution atmospherique (AQLPA) has prepared a memoire that recommends several means of reducing air pollution emissions generated by ORVs. The memoire discusses measures such as more rigorous regulations regarding the allowed power of the engines; obligations by manufacturers to resort to anti pollution measures; the imposition of strict standards on pollutant emissions; as well as a policy that respects the rights of people and the environment regarding the use and installation of paths for ORVs. Other recommendations include equipping the vehicles with a catalytic converter; obligatory inspection of ORVs; creating a program of re-naturalization near ORV paths; and promoting alternative activities whose practices do not generate greenhouse gases and which do not contribute to air pollution. 7 tabs., 2 apps.

  12. 外部承运人可供选择的车辆路径问题的研究%The research on the vehicle routing problem with private fleet and common carrier

    Institute of Scientific and Technical Information of China (English)

    侯倩倩; 闫军; 廖理; 王博

    2014-01-01

    在协同物流的大趋势下,协同运输已成为了一种非常重要的运输方式。协同运输主要包括联盟内个体的自身资源整合以及联盟内各个企业的协同合作。在多个企业进行合作时,为了节约成本,可以有选择地将顾客委托给外部车场进行服务,这就是外部承运人可供选择下的车辆路径问题。目前,该问题的研究比较少。本文对外部承运人可供选择的车辆路径问题进行了分析研究,建立了该问题的数学模型并利用粒子群算法进行了求解。%Under the trend of collaborative logistics,collaborative transport has become an important mode of transportation .The collaborative transportation mainly includes the individual's own resources integration and the collaboration among enterprises within the alliance .In the process of collaboration among the alliance ,each customer is served by one of the vehicles of an internal fleet or by an external common carrier,in order to minimize the cost,which is called the Vehicle Routing Problem with Private Fleet and Common Carrier.At present,there is little study about this problem.In this paper,the problem is analyzed and solved by the particle swarm optimization ( PSO) while the mathematical mode is established land the corresponding process is shown.

  13. Systems and methods for vehicle speed management

    Science.gov (United States)

    Sujan, Vivek Anand; Vajapeyazula, Phani; Follen, Kenneth; Wu, An; Forst, Howard Robert

    2016-03-01

    Controlling a speed of a vehicle based on at least a portion of a route grade and a route distance divided into a plurality of route sections, each including at least one of a section grade and section length. Controlling the speed of the vehicle is further based on determining a cruise control speed mode for the vehicle for each of the plurality of route sections and determining a speed reference command of the vehicle based on at least one of the cruise control speed mode, the section length, the section grade, and a current speed.

  14. A Location-Inventory-Routing Problem in Forward and Reverse Logistics Network Design

    Directory of Open Access Journals (Sweden)

    Qunli Yuchi

    2016-01-01

    Full Text Available We study a new problem of location-inventory-routing in forward and reverse logistic (LIRP-FRL network design, which simultaneously integrates the location decisions of distribution centers (DCs, the inventory policies of opened DCs, and the vehicle routing decision in serving customers, in which new goods are produced and damaged goods are repaired by a manufacturer and then returned to the market to satisfy customers’ demands as new ones. Our objective is to minimize the total costs of manufacturing and remanufacturing goods, building DCs, shipping goods (new or recovered between the manufacturer and opened DCs, and distributing new or recovered goods to customers and ordering and storage costs of goods. A nonlinear integer programming model is proposed to formulate the LIRP-FRL. A new tabu search (NTS algorithm is developed to achieve near optimal solution of the problem. Numerical experiments on the benchmark instances of a simplified version of the LIRP-FRL, the capacitated location routing problem, and the randomly generated LIRP-FRL instances demonstrate the effectiveness and efficiency of the proposed NTS algorithm in problem resolution.

  15. 考虑装卸频率的大规模车辆路径问题研究%Research on large scale vehicle routing problem with handling frequency

    Institute of Scientific and Technical Information of China (English)

    马汉武; 徐森; 朱维

    2011-01-01

    Trough analyzing the characteristics of the large scale vehicle routing problem (LSVRP) and the solving difficulties, introduced the concept of handling frequency. Based on the conception, considered LSVRP in a new version, and established a multiple objectives planning model with the handling frequency. Proposed an improved hybrid genetic algorithm to solve the problem efficiently. Finally, introduced the improved hybrid genetic algorithm to solve the problem efficiently. The test proves that the algorithm, with practical value and broad application prospect, may greatly reduce the distribution cost and the handling frequency.%通过分析大规模车辆路径问题的特点和求解难点,从我国的配送实践出发,引入装卸频率的概念,从新的视角认识大规模车辆路径问题,建立了考虑装卸频率的车辆路径优化多目标规划模型,并设计了改进的混合遗传算法进行求解.实验结果表明,该算法能够大幅降低企业配送成本和配送的装卸频率,具有实际参考价值和应用前景.

  16. 带有次序限制的装卸一体化车辆路径问题研究%The Study for Vehicle Routing Problem with Simultaneous Delivery and Pickup and Order limit

    Institute of Scientific and Technical Information of China (English)

    黄秋爱; 李珍萍

    2014-01-01

    The vehicle routing problem with simultaneous delivery and pickup is studied in this paper. According to the practical case, the constraint of order limit is added. Then the mathematical model aiming at finding out the minimum distance is established. At the same time, an improved genetic algorithm based on the best selection method is designed and used to solve this model. Finally, the validity of the model and algorithm are tested by practical example.%研究了装卸一体化的车辆路径问题,根据问题的实际情况,增加了带有次序限制条件,并以总行驶路线最短为目标,建立了数学模型,并根据模型的特点,用改进的遗传算法进行求解。最后,通过具体实例验证了模型及算法的有效性。

  17. 求解异车型同时集送问题的多属性标签算法%A heuristic algorithm for vehicle routing problem with heterogeneous fleet, simultaneous pickup and delivery

    Institute of Scientific and Technical Information of China (English)

    田宇; 伍炜勤

    2015-01-01

    针对实际运输中顾客对不同车型、同时集送货物的多样化需求,文章建立了异车型同时集送车辆路径模型(vehicle routing problem with heterogeneous fleet,simultaneous pickup and delivery,VRPHSPD),并构建了基于多属性标签的蚁群系统算法(multi-label based ant colony system,MLACS)进行求解.该算法利用面向对象理念,分别对客户、车辆及其行驶路径构建多属性标签,首先用近邻法生成初始路径,再通过蚁群算法的搜索规则对客户和车辆标签进行匹配,从而得优化的结果.通过公开算例、实际应用案例的验证表明,MLACS算法能成功求解VRPHSPD问题,具有较高的求解质量、运算效率以及实际应用意义.

  18. Vehicle routing problem in distribution with two-dimensional loading constraint%带二维装箱约束的物流配送车辆路径问题

    Institute of Scientific and Technical Information of China (English)

    王征; 胡祥培; 王旭坪

    2011-01-01

    In real distributions, there is a great amount of transportation problems called vehicle routing problem with two-dimensional loading constraint, in which items demanded by customers are usually fragile and needed to be packed into vehicles. This is a new problem that combines the two classical problems of vehicle routing problem and bin packing problem. To solve the problem, a mathematical model and a Memetic algorithm were presented after an explicit problem definition. The key modules of the algorithm, such as a depth-first based heuristic loading method, an encoding and splitting method of chromosomes, an initial solution generation method, crossover and local search methods, were explained in details. Based on some preliminary experiments, the best combination of parameters' values in Memetic algorithm was given. Finally, the robustness and the effectiveness of the Memetic algorithm were tested on Iori's 30 instances whose numbers of customers are from 20 to 199 and a comparison with other algorithm in the literature was made, which shows that the memetic algorithm greatly surpasses the algorithm on aspects of solving capacity and solution quality.%现实物流活动中大量存在的易损、易碎物品的运输问题属于带二维装箱约束的物流配送问题,该问题是二维装箱问题与车辆路径问题这两个经典难题融合之后的一个新问题.针对这一问题,在对其进行明确定义的基础上,建立了数学模型,提出了解决该问题一个Memetic算法,对算法中的几个关键算子:深度优先的启发式装箱方法、染色体的编码方式及其路径分割程序、初始解的生成方法、交叉算子、局部搜索算子,进行了详细的阐述.通过初步的实验,确定了Memetic算法的最佳参数配置;然后在Iori提出的30个顾客数在20 199个标准算例上对算法的鲁棒性、求解的质量、以及求解性能等几项指标进行了测试,并与文献中的求解结果进行了比

  19. Bioenergetics of Mammalian Sperm Capacitation

    Directory of Open Access Journals (Sweden)

    Alessandra Ferramosca

    2014-01-01

    Full Text Available After ejaculation, the mammalian male gamete must undergo the capacitation process, which is a prerequisite for egg fertilization. The bioenergetics of sperm capacitation is poorly understood despite its fundamental role in sustaining the biochemical and molecular events occurring during gamete activation. Glycolysis and mitochondrial oxidative phosphorylation (OXPHOS are the two major metabolic pathways producing ATP which is the primary source of energy for spermatozoa. Since recent data suggest that spermatozoa have the ability to use different metabolic substrates, the main aim of this work is to present a broad overview of the current knowledge on the energy-producing metabolic pathways operating inside sperm mitochondria during capacitation in different mammalian species. Metabolism of glucose and of other energetic substrates, such as pyruvate, lactate, and citrate, is critically analyzed. Such knowledge, besides its obvious importance for basic science, could eventually translate into the development of novel strategies for treatment of male infertility, artificial reproduction, and sperm selection methods.

  20. Improving capacitance/damping ratio in a capacitive MEMS transducer

    International Nuclear Information System (INIS)

    Damping forces play an important role in capacitive MEMS (microelectromechanical systems) behavior, and typical damper design (parallel-plates) cannot address the design conflict between increase in electrical capacitance and damping reduction. Squeeze-film damping in in-plane parallel-plate MEMS is discussed here and a novel damper geometry for gap-varying parallel-plates is introduced and used to increase the capacitance/damping ratio. The new geometry is compared with a typical parallel-plate design for an silicon-on-insulator process (25 µm thick) and experimental data shows an approximate 25% to 50% reduction for the damping coefficient in structures with 500 µm long dampers (for a gap variation between 0.75 and 3.75 µm), in agreement with computational fluid dynamics simulations, without significantly affecting the capacitance value (∼4% reduction). Preliminary simulations to study the role of the different geometric parameters involved in the improved geometry are also performed and reveal that the channel width is the most critical value for effective damping reduction. (paper)

  1. Linearization and Decomposition Methods for Large Scale Stochastic Inventory Routing Problem with Service Level Constraints

    NARCIS (Netherlands)

    Y. Yu (Yugang); C. Chu (Chengbin); H.X. Chen (Haoxun); F. Chu (Feng)

    2010-01-01

    textabstractA stochastic inventory routing problem (SIRP) is typically the combination of stochastic inventory control problems and NP-hard vehicle routing problems, for a depot to determine delivery volumes to its customers in each period, and vehicle routes to distribute the delivery volumes. This

  2. Large scale stochastic inventory routing problems with split delivery and service level constraints

    NARCIS (Netherlands)

    Y. Yu (Yugang); C. Chu (Chengbin); H.X. Chen (Haoxun); F. Chu (Feng)

    2010-01-01

    textabstractA stochastic inventory routing problem (SIRP) is typically the combination of stochastic inventory control problems and NP-hard vehicle routing problems, which determines delivery volumes to the customers that the depot serves in each period, and vehicle routes to deliver the volumes. Th

  3. Application Research of Hybrid ant Colony Algorithm in Vehicle Routing Problem with Time Windows%一种带时间窗车辆路径问题的混合蚁群算法

    Institute of Scientific and Technical Information of China (English)

    黄震; 罗中良; 黄时慰

    2015-01-01

    A hybrid ant colony algorithm was proposed.Because,ant colony algorithm used to solve the vehicle routing problem with time windows (VRPTW)is easy to fall into local optimum,and the quality of initial population in genetic algorithm affects the effectiveness of the algorithm directly.Firstly,the al-gorithm introduces the factors of time windows into node selection probability formula of ant colony algo-rithm to get the initial population.Secondly,the crossover and the mutation were operated to get a better path for the initial population.Applying Matlab environment for hybrid algorithm simulation,the effects on the vehicle utilization and path planning is obvious.It shows the algorithm is efficient,and can avoid falling into local optimum.%针对带时间窗车辆路径问题求解时蚁群算法存在容易陷入局部最优,而遗传算法初始种群的优劣对算法有效性存在直接影响,提出一种混合蚁群优化算法。算法首先在蚁群算法的节点选择概率公式中引入时间窗因素,以得到初始种群,然后通过遗传算法的交叉算子和变异算子对初始种群中的较优路径进行交叉和变异操作,从而得到更优的路径。通过 Matlab 环境下对文中混合算法进行仿真实验,在车辆利用率和路径规划上效果明显,表明了算法的高效性,同时混合算法可以避免陷入局部最优。

  4. Water desalination via capacitive deionization

    NARCIS (Netherlands)

    Suss, M.E.; Porada, S.; Sun, X.; Biesheuvel, P.M.; Yoon, J.; Presser, V.

    2015-01-01

    Capacitive deionization (CDI) is an emerging technology for the facile removal of charged ionic species from aqueous solutions, and is currently being widely explored for water desalination applications. The technology is based on ion electrosorption at the surface of a pair of electrically charg

  5. Driven shielding capacitive proximity sensor

    Science.gov (United States)

    Vranish, John M. (Inventor); McConnell, Robert L. (Inventor)

    2000-01-01

    A capacitive proximity sensing element, backed by a reflector driven at the same voltage as and in phase with the sensor, is used to reflect the field lines away from a grounded robot arm towards an intruding object, thus dramatically increasing the sensor's range and sensitivity.

  6. Voltage Dependence of Supercapacitor Capacitance

    Directory of Open Access Journals (Sweden)

    Szewczyk Arkadiusz

    2016-09-01

    Full Text Available Electronic Double-Layer Capacitors (EDLC, called Supercapacitors (SC, are electronic devices that are capable to store a relatively high amount of energy in a small volume comparing to other types of capacitors. They are composed of an activated carbon layer and electrolyte solution. The charge is stored on electrodes, forming the Helmholtz layer, and in electrolyte. The capacitance of supercapacitor is voltage- dependent. We propose an experimental method, based on monitoring of charging and discharging a supercapacitor, which enables to evaluate the charge in an SC structure as well as the Capacitance-Voltage (C-V dependence. The measurement setup, method and experimental results of charging/discharging commercially available supercapacitors in various voltage and current conditions are presented. The total charge stored in an SC structure is proportional to the square of voltage at SC electrodes while the charge on electrodes increases linearly with the voltage on SC electrodes. The Helmholtz capacitance increases linearly with the voltage bias while a sublinear increase of total capacitance was found. The voltage on SC increases after the discharge of electrodes due to diffusion of charges from the electrolyte to the electrodes. We have found that the recovery voltage value is linearly proportional to the initial bias voltage value.

  7. Capacitive Proximity Sensor Has Longer Range

    Science.gov (United States)

    Vranish, John M.

    1992-01-01

    Capacitive proximity sensor on robot arm detects nearby object via capacitive effect of object on frequency of oscillator. Sensing element part of oscillator circuit operating at about 20 kHz. Total capacitance between sensing element and ground constitutes tuning capacitance of oscillator. Sensor circuit includes shield driven by replica of alternating voltage applied to sensing element. Driven shield concentrates sensing electrostatic field in exterior region to enhance sensitivity to object. Sensitivity and dynamic range has corresponding 12-to-1 improvement.

  8. 应用蜜蜂繁殖进化型粒子群算法求解车辆路径问题%A Bee Evolutionary Particle Swarm Optimization Algorithm for Vehicle Routing Problem

    Institute of Scientific and Technical Information of China (English)

    寇明顺; 叶春明; 陈子皓

    2012-01-01

    为了提高粒子群算法求解车辆路径问题时收敛速度和全局搜索能力,将蜜蜂繁殖进化机制与粒子群算法相结合,应用到CVRP问题的求解.该算法中,最优的个体作为蜂王与通过选择机制选择的雄蜂以随机概率进行交叉,增强了最优个体信息的应用能力;同时,随机产生一部分雄蜂种群,并将其与蜂王交叉增加了算法的多样性.实例分析表明该算法具有较好的全局搜索能力,验证了该算法的可行性.%The vehicle routing problem (VRP) is discussed in this paper. There are studies that solve VRP by using particle swarm optimization (PSO) algorithm. However, with traditional PSO, it has slow convergence rate and a local optimum may be obtained. In order to improve the performance of PSO, an algorithm called bee evolutionary particle swarm optimization (BEPSO) is presented for VRP in this paper. By this algorithm, the best particle regarded as the queen crosses with the selected drones randomly. In this way, it takes the advantage of the best individual's information. At the same time, some drones are randomly generated and crossed with the queen such that diversity is enlarged. Experimental test shows that the proposed algorithm has better global search ability than the existing ones.

  9. Based on particles collision PSO for vehicle routing problem with time windows%基于粒子碰撞的粒子群算法求解带时间窗车辆调度问题

    Institute of Scientific and Technical Information of China (English)

    秦家娇; 张勇; 毛剑琳; 付丽霞

    2012-01-01

    带时间窗车辆调度问题属于离散NP-hard组合优化问题,传统的粒子群算法在离散域上表现了一定的劣性,对此提出了一种基于粒子碰撞的离散PSO算法来求解该问题.受物体相互碰撞之后物体的速度和位置会发生改变的现象启发,使当前粒子与个体最优和全局最优粒子发生碰撞来更新粒子的位置,以避免传统更新操作中的取整,保证种群的进化能力.采用Solomon's VRP标准问题集的实例来对算法进行测试,实验结果数据表明了该算法的有效性.%The vehicle routing problem with time windows (VRPTW) is the NP-hard combinatorial optimization discrete problem. There was certain inferiority performance on solving it with traditional PSO, so this paper proposed a particles collision discrete PSO to solve it. Inspired by the physical phenomena of the velocity and position changed after objects collision, it made the current particle collided with the personal best particle and global best particle to avoid the tradition rounding operating in updating, and kept particles swarm evolutional capability. It used the Solomon' s VRP instance to test. The results of experiments show that the algorithm has good performance.

  10. 协同物流模式下多批次整车运输调度问题%Research on the Full-loaded Vehicle Routing Problem with Multiple Batches in Collaborative Transportation Mode

    Institute of Scientific and Technical Information of China (English)

    魏江宁; 陆志强; 奚立峰

    2009-01-01

    The vehicle routing problem with time windows as well as multiple pickups and deliveries was studied in collaborative transportation mode. A mathematical model was developed considering the factors such as the number of trucks rented, the distances covered, and the penalty due to service delay. A hybrid genetic algorithm was proposed accordingly, integrating the restarting scheme which is able to improve the initial population and avoid premature convergence respectively. In addition, the local research strategy was fully used to get the optimal value quickly. The results of the computational experiment indicate that the proposed algorithm is effective.%研究了协同物流模式下,单车库、多集散点的带时间窗以及单点多批次配送与集货请求的联合运输问题.考虑车辆的租用费用、行驶费用、未按时完成服务产生的惩罚费用等因素,建立了数学模型并提出了混合遗传算法.算法中加入了重启动机制,以提高种群质量和避免早熟收敛,并采用局部搜索策略以快速寻找最优值.数值实验证明,混合遗传算法求解该类运输调度问题具有良好的效果,且算法效率较高.

  11. Active Targets For Capacitive Proximity Sensors

    Science.gov (United States)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Lightweight, low-power active targets devised for use with improved capacitive proximity sensors described in "Capacitive Proximity Sensor Has Longer Range" (GSC-13377), and "Capacitive Proximity Sensors With Additional Driven Shields" (GSC-13475). Active targets are short-distance electrostatic beacons; they generate known alternating electro-static fields used for alignment and/or to measure distances.

  12. Simulation Based: Study and Analysis of Routing Protocol in Vehicular Ad-hoc Network Environment

    OpenAIRE

    Vaishali D. Khairnar; Pradhan, Dr. S. N.

    2012-01-01

    A Vehicular Ad hoc Network (VANET) consists of vehicles which communicate with each other and exchange data via wireless communication links available between the vehicles which are in communication ranges of vehicles to improve the road safety in city. The communication between vehicles is used to provide road safety, comfort and entertainment. The performance of communication depends on how better routing takes place in the network. Routing data between the source and destination vehicle de...

  13. Optimal Route Selection Method Based on Vague Sets

    Institute of Scientific and Technical Information of China (English)

    GUO Rui; DU Li min; WANG Chun

    2015-01-01

    Optimal route selection is an important function of vehicle trac flow guidance system. Its core is to determine the index weight for measuring the route merits and to determine the evaluation method for selecting route. In this paper, subjective weighting method which relies on driver preference is used to determine the weight and the paper proposes the multi-criteria weighted decision method based on vague sets for selecting the optimal route. Examples show that, the usage of vague sets to describe route index value can provide more decision-making information for route selection.

  14. Effects of stray capacitance to ground in bipolar water impedance measurements based on capacitive electrodes

    OpenAIRE

    Pallàs Areny, Ramon; Aliau Bonet, Carles

    2015-01-01

    Liquid impedance measurements based on capacitive (or contactless) electrodes Overcome electrode polarization problems but are affected by stray capacitance from the material being measured to ground, the same as measurements with direct-contact electrodes. This study shows that the effects of that capacitance depend on the impedance being measured and for bipolar impedance measurements they increase when the ratio between that stray capacitance and lectrode capacitance increases.

  15. Sensors in Unmanned Robotic Vehicle

    Directory of Open Access Journals (Sweden)

    B. Rohini

    2008-05-01

    Full Text Available Unmanned tracked vehicles are developed for deployment in dangerous zones that are notsafe for human existence. These vehicles are to be fitted with various sensors for safe manoeuvre.Wide range of sensors for vehicle control, vision, and navigation are employed. The main purposeof the sensors is to infer the intended parameter precisely for further utilisation. Software isinseparable part of the sensors and plays major role in scaling, noise reduction, and fusion.Sensor fusion is normally adapted to enhance the decision-making. Vehicle location  andorientation can be sensed through global positioning system, accelerometer, gyroscope, andcompass. The unmanned vehicle can be navigated with the help of CCD camera, radar, lidar,ultrasonic sensor, piezoelectric sensor, microphone, etc.  Proximity sensors like capacitive andRF proximity detectors can detect obstacles in close vicinity.  This paper presents an overviewof sensors normally deployed in unmanned tracked vehicles.

  16. Full-bridge capacitive extensometer

    Science.gov (United States)

    Peters, Randall D.

    1993-08-01

    Capacitive transducers have proven to be very effective sensors of small displacements, because of inherent stability and noninvasive high resolution. The most versatile ones have been those of a differential type, in which two elements are altered in opposite directions in response to change of the system parameter being monitored. Oftentimes, this differential pair has been incorporated into a bridge circuit, which is a useful means for employing synchronous detection to improve signal to noise ratios. Unlike previous differential capacitive dilatometers which used only two active capacitors, the present sensor is a full-bridge type, which is well suited to measuring low-level thermal expansions. This analog sensor is capable of 0.1 μm resolution anywhere within a range of several centimeters, with a linearity of 0.1%. Its user friendly output can be put on a strip chart recorder or directed to a computer for sophisticated data analysis.

  17. Quantum capacitance in topological insulators.

    Science.gov (United States)

    Xiu, Faxian; Meyer, Nicholas; Kou, Xufeng; He, Liang; Lang, Murong; Wang, Yong; Yu, Xinxin; Fedorov, Alexei V; Zou, Jin; Wang, Kang L

    2012-01-01

    Topological insulators show unique properties resulting from massless, Dirac-like surface states that are protected by time-reversal symmetry. Theory predicts that the surface states exhibit a quantum spin Hall effect with counter-propagating electrons carrying opposite spins in the absence of an external magnetic field. However, to date, the revelation of these states through conventional transport measurements remains a significant challenge owing to the predominance of bulk carriers. Here, we report on an experimental observation of Shubnikov-de Haas oscillations in quantum capacitance measurements, which originate from topological helical states. Unlike the traditional transport approach, the quantum capacitance measurements are remarkably alleviated from bulk interference at high excitation frequencies, thus enabling a distinction between the surface and bulk. We also demonstrate easy access to the surface states at relatively high temperatures up to 60 K. Our approach may eventually facilitate an exciting exploration of exotic topological properties at room temperature.

  18. Water desalination via capacitive deionization

    OpenAIRE

    Suss, M. E.; Porada, S.; Sun, X.; Biesheuvel, P. M.; Yoon, J.; Presser, V.

    2015-01-01

    Capacitive deionization (CDI) is an emerging technology for the facile removal of charged ionic species from aqueous solutions, and is currently being widely explored for water desalination applications. The technology is based on ion electrosorption at the surface of a pair of electrically charged electrodes, commonly composed of highly porous carbon materials. The CDI community has grown exponentially over the past decade, driving tremendous advances via new cell architectures and system de...

  19. Capacitive de-ionization electrode

    Energy Technology Data Exchange (ETDEWEB)

    Daily, III, William D.

    2013-03-19

    An electrode "cell" for use in a capacitive deionization (CDI) reactor consists of the electrode support structure, a non-reactive conductive material, the electrode accompaniment or substrate and a flow through screen/separator. These "layers" are repeated and the electrodes are sealed together with gaskets between two end plates to create stacked sets of alternating anode and cathode electrodes in the CDI reactor.

  20. Traffic optimization in transport networks based on local routing

    Science.gov (United States)

    Scellato, S.; Fortuna, L.; Frasca, M.; Gómez-Gardeñes, J.; Latora, V.

    2010-01-01

    Congestion in transport networks is a topic of theoretical interest and practical importance. In this paper we study the flow of vehicles in urban street networks. In particular, we use a cellular automata model on a complex network to simulate the motion of vehicles along streets, coupled with a congestion-aware routing at street crossings. Such routing makes use of the knowledge of agents about traffic in nearby roads and allows the vehicles to dynamically update the routes towards their destinations. By implementing the model in real urban street patterns of various cities, we show that it is possible to achieve a global traffic optimization based on local agent decisions.

  1. Using Ant Colony Optimization for Routing in VLSI Chips

    Science.gov (United States)

    Arora, Tamanna; Moses, Melanie

    2009-04-01

    Rapid advances in VLSI technology have increased the number of transistors that fit on a single chip to about two billion. A frequent problem in the design of such high performance and high density VLSI layouts is that of routing wires that connect such large numbers of components. Most wire-routing problems are computationally hard. The quality of any routing algorithm is judged by the extent to which it satisfies routing constraints and design objectives. Some of the broader design objectives include minimizing total routed wire length, and minimizing total capacitance induced in the chip, both of which serve to minimize power consumed by the chip. Ant Colony Optimization algorithms (ACO) provide a multi-agent framework for combinatorial optimization by combining memory, stochastic decision and strategies of collective and distributed learning by ant-like agents. This paper applies ACO to the NP-hard problem of finding optimal routes for interconnect routing on VLSI chips. The constraints on interconnect routing are used by ants as heuristics which guide their search process. We found that ACO algorithms were able to successfully incorporate multiple constraints and route interconnects on suite of benchmark chips. On an average, the algorithm routed with total wire length 5.5% less than other established routing algorithms.

  2. A modified ant colony optimization to solve multi products inventory routing problem

    Science.gov (United States)

    Wong, Lily; Moin, Noor Hasnah

    2014-07-01

    This study considers a one-to-many inventory routing problem (IRP) network consisting of a manufacturer that produces multi products to be transported to many geographically dispersed customers. We consider a finite horizon where a fleet of capacitated homogeneous vehicles, housed at a depot/warehouse, transport products from the warehouse to meet the demand specified by the customers in each period. The demand for each product is deterministic and time varying and each customer requests a distinct product. The inventory holding cost is product specific and is incurred at the customer sites. The objective is to determine the amount on inventory and to construct a delivery schedule that minimizes both the total transportation and inventory holding costs while ensuring each customer's demand is met over the planning horizon. The problem is formulated as a mixed integer programming problem and is solved using CPLEX 12.4 to get the lower and upper bound (best integer solution) for each problem considered. We propose a modified ant colony optimization (ACO) to solve the problem and the built route is improved by using local search. ACO performs better on large instances compared to the upper bound.

  3. Redox regulation of mammalian sperm capacitation

    Directory of Open Access Journals (Sweden)

    Cristian O′Flaherty

    2015-01-01

    Full Text Available Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species (ROS that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD (P H for sperm capacitation. Peroxiredoxins (PRDXs are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.

  4. Hybrid heuristic algorithm for heterogeneous open vehicle routing problem%多车型开放式车辆路线问题的混合启发式算法

    Institute of Scientific and Technical Information of China (English)

    王晓博; 任春玉; 李海晨

    2013-01-01

      多车型开放式车辆路线问题,是物流配送优化中不可缺少的环节。针对标准遗传算法存在收敛速度慢,局部搜索能力差,易早熟的缺点,采用混合启发式算法进行优化求解。采用实数序列编码,使问题变得更简洁;有针对性地构建初始解,提高了解的可行性;用基于排序的选择与最佳保留相结合策略,保证群体的多样性;引入部分算术交叉算子,加强染色体的全局搜索能力;利用模拟退火算法的 Boltzmann 机制,控制遗传算法的交叉、变异操作,提高了算法的收敛速度和搜索效率。仿真结果表明混合启发式算法在求解质量和计算效率上好于标准遗传算法。%Heterogeneous open vehicle routing problem is logistics optimization indispensable part. According to the standard genetic algorithm shortcomings of slowly convergent speed, weakly partial searching ability and easily premature, hybrid heuristic algorithm is used to optimize the solution. The paper uses sequence of real numbers coding so as to simplify the problem, con-structs the targeted initial solution to improve the feasibility, adopts a choice based on sort of a combination with the best reten-tion strategies to ensure the diversity of population, and uses some arithmetic crossover operator to enhance whole search ability of the chromosome. Using Boltzmann simulated annealing mechanism for controlling genetic algorithm crossover and mutation operations, it improves the convergence speed and search efficiency. Finally, the good performance can be proved by experiment calculation and concrete examples.

  5. 模糊时间窗VRP的动态规划和禁忌搜索混合算法%Dynamic programming and tabu search hybrid algorithm for Vehicle Routing Problem with fuzzy time windows

    Institute of Scientific and Technical Information of China (English)

    王君

    2014-01-01

    The Vehicle Routing Problem with Fuzzy Time Windows is addressed. A multi-objective mathematical model is designed with the objectives of logistics cost and average customer satisfaction. Based on Pareto dominance theory, a multi-objective tabu search algorithm is proposed to solve multi-objective optimization problems. Moreover, a dynamic program-ming method is embedded in the algorithm to optimize the customer satisfaction, which simplifies the original problem into tight path optimization sub-problems with the use of phasing. While fuzzy time windows are in piecewise linear and nonlinear convex membership function forms, customer beginning service time is optimized by proposed limited iteration subgradient algorithm and median iteration subgradient algorithm, respectively. Computational experiments on Solomon’s benchmark not only verify that the dynamic programming is more effective than projected subgradient methods to optimize the service level, but also show the advantages of the proposed multi-objective tabu search approach when compared with the well-known NSGA-II method.%为优化具有模糊时间窗的车辆路径问题,以物流配送成本和顾客平均满意度为目标,建立了多目标数学规划模型。基于Pareto占优的理论给出了求解多目标优化问题的并行多目标禁忌搜索算法,算法中嵌入同时优化顾客满意度的动态规划方法,运用阶段划分,把原问题分解为关于紧路径的优化子问题。对模糊时间窗为线性分段函数形式和非线性凹函数形式的隶属度函数,分别提出了次梯度有限迭代算法和次梯度中值迭代算法来优化顾客的最优开始服务时间。通过Solomon的标准算例,与次梯度投影算法的比较验证了动态规划方法优化服务水平的有效性,与主流的NSGA-II算法的对比实验表明了该研究提出的多目标禁忌搜索算法的优越性。

  6. An approach to evaluate capacitance, capacitive reactance and resistance of pivoted pads of a thrust bearing

    Science.gov (United States)

    Prashad, Har

    1992-07-01

    A theoretical approach is developed for determining the capacitance and active resistance between the interacting surfaces of pivoted pads and thrust collar, under different conditions of operation. It is shown that resistance and capacitive reactance of a thrust bearing decrease with the number of pads times the values of these parameters for an individual pad, and that capacitance increases with the number of pads times the capacitance of an individual pad. The analysis presented has a potential to diagnose the behavior of pivoted pad thrust bearings with the angle of tilt and the ratio of film thickness at the leading to trailing edge, by determining the variation of capacitance, resistance, and capacitive reactance.

  7. Smart Vehicle Tracking System

    Directory of Open Access Journals (Sweden)

    K.P.Kamble

    2012-08-01

    Full Text Available It is amazing to know how simple ideas can give a whole new dimension to the tracking and navigation industry and smart vehicle tracking system is used for tracking the vehicles. You can optimize driver routes, save petrol or gas and time, reduce theft and control the vehicle functions. Many a times it is not required to track your vehicle or target globally. In majority of cases tracking is more restricted to local purposes only, such as tracking movement of vehicle within city, tracking the raw materials within industrial estate or to know the present position of your daughter or son within city. But unfortunately in the pursuit of making things complex this simple idea is forgotten. This simple yet powerful idea forms the basis of this revolutionary project. All this coupled with a very low cost, a robust design and tremendous market potential makes this model even more attractive.

  8. Flexible PVDF ferroelectric capacitive temperature sensor

    KAUST Repository

    Khan, Naveed

    2015-08-02

    In this paper, a capacitive temperature sensor based on polyvinylidene fluoride (PVDF) capacitor is explored. The PVDF capacitor is characterized below its Curie temperature. The capacitance of the PVDF capacitor changes vs temperature with a sensitivity of 16pF/°C. The linearity measurement of the capacitance-temperature relation shows less than 0.7°C error from a best fit straight line. An LC oscillator based temperature sensor is demonstrated based on this capacitor.

  9. Nucleotide Capacitance Calculation for DNA Sequencing

    OpenAIRE

    Lu, Jun-Qiang; Zhang, X.-G.

    2008-01-01

    Using a first-principles linear response theory, the capacitance of the DNA nucleotides, adenine, cytosine, guanine, and thymine, are calculated. The difference in the capacitance between the nucleotides is studied with respect to conformational distortion. The result suggests that although an alternate current capacitance measurement of a single-stranded DNA chain threaded through a nanogap electrode may not be sufficient to be used as a standalone method for rapid DNA sequencing, the capaci...

  10. Electrical Capacitance Volume Tomography: Design and Applications

    OpenAIRE

    Warsito Warsito; Liang-Shih Fan; Qussai Marashdeh; Fei Wang

    2010-01-01

    This article reports recent advances and progress in the field of electrical capacitance volume tomography (ECVT). ECVT, developed from the two-dimensional electrical capacitance tomography (ECT), is a promising non-intrusive imaging technology that can provide real-time three-dimensional images of the sensing domain. Images are reconstructed from capacitance measurements acquired by electrodes placed on the outside boundary of the testing vessel. In this article, a review of progress on capa...

  11. Electrochemical capacitance of a leaky nanocapacitor

    OpenAIRE

    Zhao, X; Guo, H; Wang, J.

    1999-01-01

    We report a detailed theoretical investigation on electrochemical capacitance of a nanoscale capacitor where there is a DC coupling between the two conductors. For this ``leaky'' quantum capacitor, we have derived general analytic expressions of the linear and second order nonlinear electrochemical capacitance within a first principles quantum theory in the discrete potential approximation. Linear and nonlinear capacitance coefficients are also derived in a self-consistent manner without the ...

  12. Dual Cryogenic Capacitive Density Sensor

    Science.gov (United States)

    Youngquist, Robert; Mata, Carlos; Vokrot, Peter; Cox, Robert

    2009-01-01

    A dual cryogenic capacitive density sensor has been developed. The device contains capacitive sensors that monitor two-phase cryogenic flow density to within 1% accuracy, which, if temperature were known, could be used to determine the ratio of liquid to gas in the line. Two of these density sensors, located a known distance apart, comprise the sensor, providing some information on the velocity of the flow. This sensor was constructed as a proposed mass flowmeter with high data acquisition rates. Without moving parts, this device is capable of detecting the density change within a two-phase cryogenic flow more than 100 times a second. Detection is enabled by a series of two sets of five parallel plates with stainless steel, cryogenically rated tubing. The parallel plates form the two capacitive sensors, which are measured by electrically isolated digital electronics. These capacitors monitor the dielectric of the flow essentially the density of the flow and can be used to determine (along with temperature) the ratio of cryogenic liquid to gas. Combining this information with the velocity of the flow can, with care, be used to approximate the total two-phase mass flow. The sensor can be operated at moderately high pressures and can be lowered into a cryogenic bath. The electronics have been substantially improved over the older sensors, incorporating a better microprocessor, elaborate ground loop protection and noise limiting circuitry, and reduced temperature sensitivity. At the time of this writing, this design has been bench tested at room temperature, but actual cryogenic tests are pending

  13. Capacitance enhancement via electrode patterning.

    Science.gov (United States)

    Ho, Tuan A; Striolo, Alberto

    2013-11-28

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties. PMID:24289370

  14. The Comparison between Adaptive Approach and Max-min Ant Colony Algorithm for Logistics Vehicle Routing Optimization%自适应和最大最小蚁群算法的物流车辆路径优化比较

    Institute of Scientific and Technical Information of China (English)

    陈昌敏; 谢维成; 范颂颂

    2011-01-01

    Aiming at the drawbacks of slow convergence speed and being easy to fall into local optimal point for basic ant colony algorithm in logistics vehicle routing optimization issue, this paper adopted an adaptive ant colony algorithm and the max-min ant colony algorithm to overcome the basic ant colony' s shortcomings.The analysis and comparison for the two algorithms were conducted,and the simulation of vehicle routing optimization in Matlab environment using adaptive and max-min ant colony algorithm was performed as well.Experimental results show that the max-min ant colony algorithm is better than adaptive ant colony algorithm in convergence speed and shortest path search, so max-min ant colony algorithm is superior to adaptive ant colony algorithm for logistics vehicle routing optimization.%针对物流车辆路径优化问题,考虑到基本蚁群算法有收敛速度慢、易陷入局部最优的缺点,采用了自适应蚁群算法和最大最小蚁群算法进行车辆路径优化,分析、比较了这两种算法的不同并在Matlab上做了仿真.仿真实验结果显示自适应蚁群算法在收敛速度和寻找最短路径上都略逊于最大最小蚁群算法,最大最小蚁群算法在物流车辆路径优化上优于适应蚁群算法.

  15. Detection of Telomerase Activity Using Capacitance Measurements

    Science.gov (United States)

    Kang, Bong Keun; Lee, Ri Mi; Choi, Ahmi; Jung, Hyo-Il; Yoo, Kyung-Hwa

    2007-03-01

    Telomerase activity has been found in about 85% cancer cells, while no activity observed in normal cells, so that telomerase has been proposed as a marker for cancer detection. Here, we describe electrical detection of telomerase activity using capacitance measurements. We have investigated the length dependence of capacitance on DNA solutions and found that the capacitance of DNA solutions were dependent on the DNA length. In addition, upon adding telomerase into the solution of telomeric substrate primer, the capacitance was observed to change as a function of time due to the telomeric elongation. These results suggest that this novel nanosensor may be used for rapid detection of telomerase activity.

  16. Análise do uso de SIG no roteamento dos veículos de coleta de resíduos sólidos domiciliares Analysis of the use of GIS in the collecting vehicle routing of domestic solid waste

    Directory of Open Access Journals (Sweden)

    Luzenira Alves Brasileiro

    2008-12-01

    Full Text Available Relata-se neste trabalho, a análise do uso de um Sistema de Informação Geográfica - SIG como ferramenta para roteirização de veículos de coleta de resíduos sólidos domiciliares. O software utilizado foi o TransCAD, versão 3.2, que permite desenvolver rotas utilizando algoritmos que incluem o procedimento de roteirização em arco. O objetivo é minimizar a extensão total a ser percorrida pelos veículos coletores. O estudo de caso foi realizado na cidade de Ilha Solteira - SP. Os dados coletados e os resultados obtidos pelo TransCAD foram processados no software Microsoft Excel. Os resultados obtidos demonstraram reduções percentuais de até 41% na distância total percorrida e de 68% no tempo total de percurso em relação ao serviço atual.The use of Geographical Information System - GIS as a tool for the routing of the collecting vehicles of domestic solid waste was analyzed. The software TransCAD, version 3.2, was used. This GIS is used to develop routes by algorithm that includes a procedure of arc routing (Routine Arc Routing. The objective is to minimize the total distance travelled by the collecting vehicles. The case study was carried out in Ilha Solteira city. The collected data and the results obtained by TransCAD had been processed using the software Microsoft Excel. The results obtained showed that there was a decrease of 41% in the total distance and 68% in the total time compared to the current service.

  17. Module Eleven: Capacitance; Basic Electricity and Electronics Individualized Learning System.

    Science.gov (United States)

    Bureau of Naval Personnel, Washington, DC.

    In this module the student will learn about another circuit quantity, capacitance, and discover the effects of this component on circuit current, voltage, and power. The module is divided into seven lessons: the capacitor, theory of capacitance, total capacitance, RC (resistive-capacitive circuit) time constant, capacitive reactance, phase and…

  18. Capacitance Measurement with a Sigma Delta Converter for 3D Electrical Capacitance Tomography

    Science.gov (United States)

    Nurge, Mark

    2005-01-01

    This paper will explore suitability of a newly available capacitance to digital converter for use in a 3D Electrical Capacitance Tomography system. A switch design is presented along with circuitry needed to extend the range of the capacitance to digital converter. Results are then discussed for a 15+ hour drift and noise test.

  19. A Comparison of Routing Strategies for Vehicular Ad Hoc Networks

    OpenAIRE

    Füßler, Holger; Mauve, Martin; Hartenstein, Hannes; Käsemann, Michael; Vollmer, Dieter

    2002-01-01

    On this paper we investigate the use of ad-hoc routing algorithms for the exchange of data between vehicles. There are two main aspects that are of interest in this context: the specific characteristics of ad-hoc networks formed by vehicles and the applicability of existing ad-hoc routing schemes to networks that display these characteristics. In order to address both aspects we generate realistic vehicular movement patterns of highway traffic scenarios using a well validated traffic simulati...

  20. Capacitive Feedthroughs for Medical Implants

    Science.gov (United States)

    Grob, Sven; Tass, Peter A.; Hauptmann, Christian

    2016-01-01

    Important technological advances in the last decades paved the road to a great success story for electrically stimulating medical implants, including cochlear implants or implants for deep brain stimulation. However, there are still many challenges in reducing side effects and improving functionality and comfort for the patient. Two of the main challenges are the wish for smaller implants on one hand, and the demand for more stimulation channels on the other hand. But these two aims lead to a conflict of interests. This paper presents a novel design for an electrical feedthrough, the so called capacitive feedthrough, which allows both reducing the size, and increasing the number of included channels. Capacitive feedthroughs combine the functionality of a coupling capacitor and an electrical feedthrough within one and the same structure. The paper also discusses the progress and the challenges of the first produced demonstrators. The concept bears a high potential in improving current feedthrough technology, and could be applied on all kinds of electrical medical implants, even if its implementation might be challenging.

  1. Ultrahigh Temperature Capacitive Pressure Sensor

    Science.gov (United States)

    Harsh, Kevin

    2014-01-01

    Robust, miniaturized sensing systems are needed to improve performance, increase efficiency, and track system health status and failure modes of advanced propulsion systems. Because microsensors must operate in extremely harsh environments, there are many technical challenges involved in developing reliable systems. In addition to high temperatures and pressures, sensing systems are exposed to oxidation, corrosion, thermal shock, fatigue, fouling, and abrasive wear. In these harsh conditions, sensors must be able to withstand high flow rates, vibration, jet fuel, and exhaust. In order for existing and future aeropropulsion turbine engines to improve safety and reduce cost and emissions while controlling engine instabilities, more accurate and complete sensor information is necessary. High-temperature (300 to 1,350 C) capacitive pressure sensors are of particular interest due to their high measurement bandwidth and inherent suitability for wireless readout schemes. The objective of this project is to develop a capacitive pressure sensor based on silicon carbon nitride (SiCN), a new class of high-temperature ceramic materials, which possesses excellent mechanical and electric properties at temperatures up to 1,600 C.

  2. Real Time Route for Dynamic Road Congestions

    Directory of Open Access Journals (Sweden)

    A. M. Riad

    2012-05-01

    Full Text Available Minimizing service delivery and travel time during rush hours downtown is strategic target for several organizations, especially the emergency organizations. This paper presents an On-line and Real-time Dynamic Route System (ORDRS which benefits from the advantages and integration between information system and communications technology. It utilizes Global Positioning System (GPS, Geographical Information Systems (GIS, and Global System for Mobile communications (GSM; for producing the real time routes for vehicles. GPS-Tracker is the main input device for ORDRS. It is fixated in a vehicle, sends vehicle's movement data (Geo-info to the control center wirelessly through either Short Message Service (SMS or General Packet Radio Service (GPRS. Geo-info includes time, date, longitude, latitude, speed, and etc., these data is classified over time during weekdays into interval time slices, each slice is 30 minutes. Speeds are treated by GIS tools to determine historical and real time speeds for each street segment in the road network which is being used for calculating time impedance (cost matrix for each street segment dynamically. ORDRS uses a cost matrix of the current time slice for determining the best route to each vehicle in duty attached. Several algorithms was used to calculate the shortest route, a comparison between Dijekstra and Yen algorithms was studied.

  3. 多模糊信息条件下的物料配送路径规划问题研究%Vehicle Routing Problem in Material Distribution under Condition of Much Fuzzy Information

    Institute of Scientific and Technical Information of China (English)

    李晋航; 黄刚; 贾艳

    2011-01-01

    混流装配线的物料配送是支撑装配线运作的复杂系统.配送准确、及时不仅能够保证生产不断线,还能大大提高生产效率,发挥混流装配的优势.但是配送环节中往往存在工位货物需求量,工位预约到货时间和车辆运输时间不确定等因素,使得传统路径规划模型不能真实地反映现场情况,反而因种种异常导致事倍功半.对不确定因素进行考虑,建立模糊信息条件下的机会约束规划模型,并改进传统混合智能算法去求解模型.算法设计上,采用轮盘赌启发式算法来缩小初始解的搜索范围,在交叉算子中提出用广义海明相似度概念来区分染色体的相似程度,在进化过程中采用双选择双变异流程来加快算法的收敛速度.通过实例证明该算法处理不确定因素的可行性和高效性,并对模糊参数中关键因子的置信度选择不同值进行对比分析,给出选择建议.%Material distribution of mixed-model assembly is a complex system for supporting assembly line operation. Accurate distribution in time can ensure continuous production and greatly improve production efficiency. However, there often exist uncertain factors, such as work station demand for goods, appointed goods arrival time, and vehicle transportation time, so the traditional route programming model cannot truly reflect the field situation and on the contrary will cause low productivity. The uncertain factors are taken into consideration, the chance constraint programming model under the condition of fuzzy information is built, and traditional hybrid intelligent algorithm is improved to solve this model. In the selection of initial solution, roulette heuristic algorithm is adopted to reduce the search range. In the crossover operator, generalized hamming similarity degree is used to distinguish the similarity degree of two chromosomes in order to avoid inbreeding. Duplicate selected and mutated operator is chosen for

  4. Routing Proposals for Multipath Interdomain Routing

    OpenAIRE

    Bilal, Sardar M.; Dilber, Muhammad Naveed; Khan, Atta ur Rehman

    2013-01-01

    Internet is composed of numbers of independent autonomous systems. BGP is used to disseminate reachability information and establishing path between autonomous systems. Each autonomous system is allowed to select a single route to a destination and then export the selected route to its neighbors. The selection of single best route imposes restrictions on the use of alternative paths during interdomain link failure and thus, incurred packet loss. Packet loss still occurs even when multiple pat...

  5. Facile synthesis of novel graphene sponge for high performance capacitive deionization

    OpenAIRE

    Xingtao Xu; Likun Pan; Yong Liu; Ting Lu; Zhuo Sun; Chua, Daniel H. C.

    2015-01-01

    Capacitive deionization (CDI) is an effective desalination technique offering an appropriate route to obtain clean water. In order to obtain excellent CDI performance, a rationally designed structure of electrode materials has been an urgent need for CDI application. In this work, a novel graphene sponge (GS) was proposed as CDI electrode for the first time. The GS was fabricated via directly freeze-drying graphene oxide solution followed by annealing in nitrogen atmosphere. The morphology, s...

  6. Energy-Efficient Capacitive-Sensor Interfaces

    NARCIS (Netherlands)

    Tan, Z.

    2013-01-01

    This thesis describes the theory, design and realization of energy-efficient capacitive-sensor interfaces that are dedicated to energy-constrained applications. The goal of this work is to explore energy-efficient capacitive-sensor interface design techniques both at the system and the circuit level

  7. Dissecting graphene capacitance in electrochemical cell

    International Nuclear Information System (INIS)

    Quantum capacitance of graphene plays a significant role for graphene's applications in electrochemical devices and sensors, while the determination of these basic characters of Dirac point, Fermi energy, quantum capacitance, etc is still a subject of considerable debate in both experiments and simulations. Here, we report joint first-principles/continuum calculations (JFPCCs) on a monolayer graphene electrode immersed in an electrolyte coupled with a reference electrode under an applied potential. The JFPCCs gave the Fermi level, charge density on graphene, Dirac point energy, electrostatic potential, electric double layer etc as a function of the applied potential with respect to the reference electrode. These results revealed the strongly coupled relationship between Fermi level change and Dirac point shift in electrochemical cell. The total capacitance of the electrochemical cell was dissected into the quantum capacitance of the graphene electrode and the capacitance of the electric double layer. Furthermore, simple and analytic formulas were proposed for the three capacitances, which predicted, in sufficient accuracy, the behavior of capacitance versus potential. These findings deepen the understanding of quantum capacitance of graphene, which will stimulate novel experimental and theoretical studies and boost the applications of graphene in electrochemical and energy areas

  8. Quantum capacitance of the monolayer graphene

    OpenAIRE

    Cheremisin, M. V.

    2012-01-01

    The quantum capacitance of the monolayer graphene for arbitrary carrier density, magnetic field and temperature is found. The density dependence of the quantum capacitance is analyzed for magnetic field(temperature) is fixed(varied) and vice versa. The theory is compared with the experimental data.

  9. Capacitance densitometer for flow regime identification

    Science.gov (United States)

    Shipp, Jr., Roy L.

    1978-01-01

    This invention relates to a capacitance densitometer for determining the flow regime of a two-phase flow system. A two-element capacitance densitometer is used in conjunction with a conventional single-beam gamma densitometer to unambiguously identify the prevailing flow regime and the average density of a flowing fluid.

  10. Capacitance-coupled wiper increases potentiometer life

    Science.gov (United States)

    Dimeff, J.

    1968-01-01

    Capacitively-coupled wiper reduces the friction between the sliding contact and the potentiometer element in conventional potentiometers. A small preamplifier employed close to the wiper reduces errors caused by output cable capacitance. The device is friction free with resultant low wear and has high speed and high resolution.

  11. Conductivity Effect on the Capacitance Measurement of a Parallel-Plate Capacitive Sensor System

    Directory of Open Access Journals (Sweden)

    Peyman Azimi

    2011-01-01

    Full Text Available In this article design and operation of a parallel-plate capacitive sensor based on the dielectric capacitance and conductance change of the gap medium is reported. The designed system was used to determine characteristics of different water liquids as a result of the capacitance variations. The air gap capacitance is measured and then by filling the gap with a liquid the capacitance is monitored for different liquids. Proposed sensor is used for the distilled, tap, boiled, and salt water measurements and the capacitance results are compared. A big difference about 45.5 :F in capacitance values for the salt and distilled water shows a high sensitivity, which can be used to recognize different water liquids. The experimental results are promising for water liquids and verify the successful operation of such a device as a liquid sensor, a useful method for checking the electrical quality of the water that is required for different applications.

  12. Advanced Vehicle Testing and Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Garetson, Thomas [The Clarity Group, Incorporated, Chicago, IL (United States)

    2013-03-31

    The objective of the United States (U.S.) Department of Energy's (DOEs) Advanced Vehicle Testing and Evaluation (AVTE) project was to provide test and evaluation services for advanced technology vehicles, to establish a performance baseline, to determine vehicle reliability, and to evaluate vehicle operating costs in fleet operations.Vehicles tested include light and medium-duty vehicles in conventional, hybrid, and all-electric configurations using conventional and alternative fuels, including hydrogen in internal combustion engines. Vehicles were tested on closed tracks and chassis dynamometers, as well as operated on public roads, in fleet operations, and over prescribed routes. All testing was controlled by procedures developed specifically to support such testing.

  13. Visualizing Internet routing changes.

    Science.gov (United States)

    Lad, Mohit; Massey, Dan; Zhang, Lixia

    2006-01-01

    Today's Internet provides a global data delivery service to millions of end users and routing protocols play a critical role in this service. It is important to be able to identify and diagnose any problems occurring in Internet routing. However, the Internet's sheer size makes this task difficult. One cannot easily extract out the most important or relevant routing information from the large amounts of data collected from multiple routers. To tackle this problem, we have developed Link-Rank, a tool to visualize Internet routing changes at the global scale. Link-Rank weighs links in a topological graph by the number of routes carried over each link and visually captures changes in link weights in the form of a topological graph with adjustable size. Using Link-Rank, network operators can easily observe important routing changes from massive amounts of routing data, discover otherwise unnoticed routing problems, understand the impact of topological events, and infer root causes of observed routing changes.

  14. Routing in opportunistic networks

    CERN Document Server

    Dhurandher, Sanjay; Anpalagan, Alagan; Vasilakos, Athanasios

    2013-01-01

    This book provides a comprehensive guide to selected topics, both ongoing and emerging, in routing in OppNets. The book is edited by worldwide technical leaders, prolific researchers and outstanding academics, Dr. Isaac Woungang and co-editors, Dr. Sanjay Kumar Dhurandher, Prof. Alagan Anpalagan and Prof. Athanasios Vasilakos. Consisting of contributions from well known and high profile researchers and scientists in their respective specialties, the main topics that are covered in this book include mobility and routing, social-aware routing, context-based routing, energy-aware routing, incentive-aware routing, stochastic routing, modeling of intermittent connectivity, in both infrastructure and infrastructure-less OppNets. Key Features: Discusses existing and emerging techniques for routing in infrastructure and infrastructure-less OppNets. Provides a unified covering of otherwise disperse selected topics on routing in infrastructure and infrastructure-less OppNets.  Includes a set of PowerPoint slides and g...

  15. Solving a bi-objective mathematical model for location-routing problem with time windows in multi-echelon reverse logistics using metaheuristic procedure

    Science.gov (United States)

    Ghezavati, V. R.; Beigi, M.

    2016-06-01

    During the last decade, the stringent pressures from environmental and social requirements have spurred an interest in designing a reverse logistics (RL) network. The success of a logistics system may depend on the decisions of the facilities locations and vehicle routings. The location-routing problem (LRP) simultaneously locates the facilities and designs the travel routes for vehicles among established facilities and existing demand points. In this paper, the location-routing problem with time window (LRPTW) and homogeneous fleet type and designing a multi-echelon, and capacitated reverse logistics network, are considered which may arise in many real-life situations in logistics management. Our proposed RL network consists of hybrid collection/inspection centers, recovery centers and disposal centers. Here, we present a new bi-objective mathematical programming (BOMP) for LRPTW in reverse logistic. Since this type of problem is NP-hard, the non-dominated sorting genetic algorithm II (NSGA-II) is proposed to obtain the Pareto frontier for the given problem. Several numerical examples are presented to illustrate the effectiveness of the proposed model and algorithm. Also, the present work is an effort to effectively implement the ɛ-constraint method in GAMS software for producing the Pareto-optimal solutions in a BOMP. The results of the proposed algorithm have been compared with the ɛ-constraint method. The computational results show that the ɛ-constraint method is able to solve small-size instances to optimality within reasonable computing times, and for medium-to-large-sized problems, the proposed NSGA-II works better than the ɛ-constraint.

  16. 36 CFR 4.10 - Travel on park roads and designated routes.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Travel on park roads and... THE INTERIOR VEHICLES AND TRAFFIC SAFETY § 4.10 Travel on park roads and designated routes. (a) Operating a motor vehicle is prohibited except on park roads, in parking areas and on routes and...

  17. 36 CFR 1004.10 - Travel on Presidio Trust roads and designated routes.

    Science.gov (United States)

    2010-07-01

    ... roads and designated routes. 1004.10 Section 1004.10 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.10 Travel on Presidio Trust roads and designated routes. (a) Operating a motor vehicle is prohibited except on Presidio Trust roads and in parking areas. (b) The following...

  18. Routing on Metacyclic Graphs

    Institute of Scientific and Technical Information of China (English)

    Wenjun Xiao

    2002-01-01

    Wu, Lakshmivarahan and Dhall[5] recently described a deterministic, distributed routing scheme for some special classes of metacyclic graphs. However they have no proof of correctness that the scheme is a shortest path routing algorithm. In the note we give a suboptimal, deterministic routing algorithm.

  19. Complementary surface charge for enhanced capacitive deionization

    NARCIS (Netherlands)

    Gao, X.; Porada, S.; Omosebi, A.; Liu, K.L.; Biesheuvel, P.M.; Landon, J.

    2016-01-01

    Commercially available activated carbon cloth electrodes are treated using nitric acid and ethylenediamine solutions, resulting in chemical surface charge enhanced carbon electrodes for capacitive deionization (CDI) applications. Surface charge enhanced electrodes are then configured in a CDI cel

  20. Highly sensitive micromachined capacitive pressure sensor with reduced hysteresis and low parasitic capacitance

    DEFF Research Database (Denmark)

    Pedersen, Thomas; Fragiacomo, Giulio; Hansen, Ole;

    2009-01-01

    This paper describes the design and fabrication of a capacitive pressure sensor that has a large capacitance signal and a high sensitivity of 76 pF/bar in touch mode operation. Due to the large signal, problems with parasitic capacitances are avoided and hence it is possible to integrate the sens...... bonding to create vacuum cavities. The exposed part of the sensor is perfectly flat such that it can be coated with corrosion resistant thin films. Hysteresis is an inherent problem in touch mode capacitive pressure sensors and a technique to significantly reduce it is presented....

  1. Automatic Power Factor Correction Using Capacitive Bank

    OpenAIRE

    Mr.Anant Kumar Tiwari,; Mrs. Durga Sharma

    2014-01-01

    The power factor correction of electrical loads is a problem common to all industrial companies. Earlier the power factor correction was done by adjusting the capacitive bank manually [1]. The automated power factor corrector (APFC) using capacitive load bank is helpful in providing the power factor correction. Proposed automated project involves measuring the power factor value from the load using microcontroller. The design of this auto-adjustable power factor correction is ...

  2. State alternative route designations

    Energy Technology Data Exchange (ETDEWEB)

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a ``state routing agency,`` defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective.

  3. State alternative route designations

    Energy Technology Data Exchange (ETDEWEB)

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a state routing agency,'' defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective.

  4. Vehicle to Vehicle Services

    DEFF Research Database (Denmark)

    Brønsted, Jeppe Rørbæk

    2008-01-01

    As computing devices, sensors, and actuators pervade our surroundings, new applications emerge with accompanying research challenges. In the transportation domain vehicles are being linked by wireless communication and equipped with an array of sensors and actuators that make is possible to provide...... location aware infotainment, increase safety, and lessen environmental strain. This dissertation is about service oriented architecture for pervasive computing with an emphasis on vehicle to vehicle applications. If devices are exposed as services, applications can be created by composing a set of services...... and governing the flow of data among them. In pervasive computing, composing services is, however, not the whole story. To fully realize their potential, applications must also deal with challenges such as device heterogeneity, context awareness, openendedness, and resilience to dynamism in network connectivity...

  5. A Review Of Design And Control Of Automated Guided Vehicle Systems

    NARCIS (Netherlands)

    T. Le-Anh (Tuan); M.B.M. de Koster (René)

    2004-01-01

    textabstractThis paper presents a review on design and control of automated guided vehicle systems. We address most key related issues including guide-path design, estimating the number of vehicles, vehicle scheduling, idle-vehicle positioning, battery management, vehicle routing, and conflict resol

  6. Multi-Objective Algorithm for Blood Supply via Unmanned Aerial Vehicles to the Wounded in an Emergency Situation.

    Science.gov (United States)

    Wen, Tingxi; Zhang, Zhongnan; Wong, Kelvin K L

    2016-01-01

    Unmanned aerial vehicle (UAV) has been widely used in many industries. In the medical environment, especially in some emergency situations, UAVs play an important role such as the supply of medicines and blood with speed and efficiency. In this paper, we study the problem of multi-objective blood supply by UAVs in such emergency situations. This is a complex problem that includes maintenance of the supply blood's temperature model during transportation, the UAVs' scheduling and routes' planning in case of multiple sites requesting blood, and limited carrying capacity. Most importantly, we need to study the blood's temperature change due to the external environment, the heating agent (or refrigerant) and time factor during transportation, and propose an optimal method for calculating the mixing proportion of blood and appendage in different circumstances and delivery conditions. Then, by introducing the idea of transportation appendage into the traditional Capacitated Vehicle Routing Problem (CVRP), this new problem is proposed according to the factors of distance and weight. Algorithmically, we use the combination of decomposition-based multi-objective evolutionary algorithm and local search method to perform a series of experiments on the CVRP public dataset. By comparing our technique with the traditional ones, our algorithm can obtain better optimization results and time performance.

  7. Capacitance of Graphene Bilayer as a Which-Layer Probe

    OpenAIRE

    Young, Andrea F.; Levitov, Leonid S.

    2011-01-01

    The unique capabilities of capacitance measurements in bilayer graphene enable probing of layer-specific properties that are normally out of reach in transport measurements. Furthermore, capacitance measurements in the top-gate and penetration field geometries are sensitive to different physical quantities: the penetration field capacitance probes the two layers equally, whereas the top gate capacitance preferentially samples the near layer, resulting in the "near-layer capacitance enhancemen...

  8. Nanoscale capacitance: A classical charge-dipole approximation

    OpenAIRE

    Jun-Qiang Lu; Jonathan Gonzalez; Carlos Sierra; Yang Li

    2013-01-01

    Modeling nanoscale capacitance presents particular challenge because of dynamic contribution from electrodes, which can usually be neglected in modeling macroscopic capacitance and nanoscale conductance. We present a model to calculate capacitances of nano-gap configurations and define effective capacitances of nanoscale structures. The model is implemented by using a classical atomic charge-dipole approximation and applied to calculate capacitance of a carbon nanotube nano-gap and effective ...

  9. Predictive cruise control in hybrid electric vehicles

    NARCIS (Netherlands)

    Keulen, T. van; Naus, M.J.G.; Jager, B. de; Molengraft, G.J.L. van de; Steinbuch, M.; Aneke, N.P.I.

    2009-01-01

    Deceleration rates have considerable influence on the fuel economy of hybrid electric vehicles. Given the vehicle characteristics and actual/measured operating conditions, as well as upcoming route information, optimal velocity trajectories can be constructed that maximize energy recovery. To suppor

  10. Carbon flow electrodes for continuous operation of capacitive deionization and capacitive mixing energy generation

    NARCIS (Netherlands)

    Porada, S.; Hamelers, H.V.M.; Bryjak, M.; Presser, V.; Biesheuvel, P.M.; Weingarth, D.

    2014-01-01

    Capacitive technologies, such as capacitive deionization and energy harvesting based on mixing energy (“capmix” and “CO2 energy”), are characterized by intermittent operation: phases of ion electrosorption from the water are followed by system regeneration. From a system application point of view, c

  11. 基于软时间窗的产品配送与安装相分离的车辆调度优化%Optimization for vehicle routeing with separated delivery and installation of products based on soft time windows

    Institute of Scientific and Technical Information of China (English)

    庞海军; 丁以中

    2012-01-01

    In order to satisfy the unique need of logistics in electronics industry, a variant of the Vehicle Routeing Problem (VRP) is studied based on the unique characteristics of electronics industry. The synchronism of the delivery and installation of products is separated, and a Mixed-Integer Nonlinear Programming (MINP) model is presented to minimize the traveling time of delivery and installation, which is the optimization model of VRP for delivery and installation based on soft time windows. Comparative analysis of the results illustrates the feasibility and effectiveness of the hierarchical approach and Genetic Algorithm (GA). The method can improve the efficiency of logistics distribution, reduce the enterprises' logistics cost, and improve the service level.%为满足电子行业独特的物流配送需求,依据电子行业的特点,研究一种变形的车辆调度问题(Vehicle Routeing Problem,VRP).将产品的配送与安装的同步性进行分离,建立以最小配送和安装旅行时间为目标的混合整数非线性规划(Mixed-Integer Nonlinear Programming,MINP)模型,即基于软时间窗的配送和安装车辆调度优化模型.对算例计算结果的比较分析表明采用分层方法和遗传算法(Genetic Algorithm,GA)的可行性和有效性.该模型可以提高电子行业的物流配送效率,降低物流成本,提高服务水平.

  12. The Vehicle Routing Problem with Simultaneous Pickup and Delivery Considering Customer Satisfaction%考虑客户满意度的同时收发车辆路径问题

    Institute of Scientific and Technical Information of China (English)

    范静

    2011-01-01

    当客户要求车辆一次性完成发送以及收集货物的任务时, 只需考虑车辆的路径安排即可.但若客户进一步提出在时间窗内完成的话,就必须考虑客户的等待时间--客户的满意度的衡量标准,等待时间越短满意度越高.因此问题的目标为最小化车辆路径总长度、最小化所有客户等待时间之和.本文通过加权转变为单目标函数,由最邻近法及最廉价插入法得到初始解后经过禁忌搜索算法可得到改进算法,解并通过实例对不同权参数的情况进行了比较.%When customers require the vehicles to pickup and delivery goods simultaneous, we just consider how to arrange the path of every vehicle.However, if costomers further propose the vehicles to complete within time windows, costumers' waiting time which is regarded as the criterion of customers satisfaction must be considered, that is, the shorter, the higher the satisfaction.Therefore the goal is to minimize the total length of vehicles' paths, and to minimize the sum of all customers' waiting time.In this paper, combining into a single objective function by weight, initial solution, obtained by the nearest neighbor method and the cheapest insertion method, can be improved by tabu search algorithm.Finally solutions of different parameters are compared.

  13. Traffic-Adaptive Routing

    OpenAIRE

    Kammenhuber, Nils

    2011-01-01

    Despite the bursty and highly volatile traffic, routing in the Internet today is optimised only on coarse time scales, as load-adaptive routing is known to induce performance deterioration by causing massive oscillations. We describe ReplEx, an universally applicable distributed algorithm for dynamic routing/traffic engineering, which is based on game theory. We show through extensive realistic simulations that ReplEx does not oscillate, and that it achieves performance gains comparable to tr...

  14. Real-time and label-free monitoring of nanoparticle cellular uptake using capacitance-based assays

    Science.gov (United States)

    Lee, Rimi; Jo, Dong hyun; Chung, Sang J.; Na, Hee-Kyung; Kim, Jeong Hun; Lee, Tae Geol

    2016-01-01

    Nanoparticles have shown great potential as vehicles for the delivery of drugs, nucleic acids, and therapeutic proteins; an efficient, high-throughput screening method to analyze nanoparticle interaction with the cytomembrane would substantially improve the efficiency and accuracy of the delivery. Here, we developed a capacitance sensor array that monitored the capacitance values of nanoparticle-treated cells in a real-time manner, without the need for labeling. Upon cellular uptake of the nanoparticles, a capacitance peak was observed at a low frequency (e.g., 100 Hz) as a function of time based on zeta potential changes. In the high frequency region (e.g., 15–20 kHz), the rate of decreasing capacitance slowed as a function of time compared to the cell growth control group, due to increased cytoplasm resistance and decreased membrane capacitance and resistance. The information provided by our capacitance sensor array will be a powerful tool for scientists designing nanoparticles for specific purposes. PMID:27641838

  15. Contact Graph Routing

    Science.gov (United States)

    Burleigh, Scott C.

    2011-01-01

    Contact Graph Routing (CGR) is a dynamic routing system that computes routes through a time-varying topology of scheduled communication contacts in a network based on the DTN (Delay-Tolerant Networking) architecture. It is designed to enable dynamic selection of data transmission routes in a space network based on DTN. This dynamic responsiveness in route computation should be significantly more effective and less expensive than static routing, increasing total data return while at the same time reducing mission operations cost and risk. The basic strategy of CGR is to take advantage of the fact that, since flight mission communication operations are planned in detail, the communication routes between any pair of bundle agents in a population of nodes that have all been informed of one another's plans can be inferred from those plans rather than discovered via dialogue (which is impractical over long one-way-light-time space links). Messages that convey this planning information are used to construct contact graphs (time-varying models of network connectivity) from which CGR automatically computes efficient routes for bundles. Automatic route selection increases the flexibility and resilience of the space network, simplifying cross-support and reducing mission management costs. Note that there are no routing tables in Contact Graph Routing. The best route for a bundle destined for a given node may routinely be different from the best route for a different bundle destined for the same node, depending on bundle priority, bundle expiration time, and changes in the current lengths of transmission queues for neighboring nodes; routes must be computed individually for each bundle, from the Bundle Protocol agent's current network connectivity model for the bundle s destination node (the contact graph). Clearly this places a premium on optimizing the implementation of the route computation algorithm. The scalability of CGR to very large networks remains a research topic

  16. Ion channels, phosphorylation and mammalian sperm capacitation.

    Science.gov (United States)

    Visconti, Pablo E; Krapf, Dario; de la Vega-Beltrán, José Luis; Acevedo, Juan José; Darszon, Alberto

    2011-05-01

    Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.

  17. Ion channels, phosphorylation and mammalian sperm capacitation

    Institute of Scientific and Technical Information of China (English)

    Pablo E Visconti; Dario Krapf; José Luis de la Vega-Beltrán; Juan José Acevedo; Alberto Darszon

    2011-01-01

    Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.

  18. Simulation Based: Study and Analysis of Routing Protocol in Vehicular Ad-hoc Network Environment

    Directory of Open Access Journals (Sweden)

    Vaishali D. Khairnar

    2012-03-01

    Full Text Available A Vehicular Ad hoc Network (VANET consists of vehicles which communicate with each other and exchange data via wireless communication links available between the vehicles which are in communication ranges of vehicles to improve the road safety in city. The communication between vehicles is used to provide road safety, comfort and entertainment. The performance of communication depends on how better routing takes place in the network. Routing data between the source and destination vehicle depends on the routing protocols being used in vehicular ad-hoc network. In this simulation based study we investigated about different ad hoc routing protocols for vehicular ad-hoc network (VANET. The main goal of our study was to identify which ad hoc routing protocol has better performance in highly mobile environment of vehicular ad-hoc network. We have measured the performance of routing protocols using 802.11p in vehicular ad-hoc network in which we considered the scenario of city (i.e. Route between Nerul and Vashi where we have take 1200 different types of vehicles and checked their performance. Routing protocols are selected after the literature review. The selected protocols are then evaluated through simulation under 802.11p in terms of performance metrics (i.e PDR & E2E delay

  19. Exact methods for time constrained routing and related scheduling problems

    DEFF Research Database (Denmark)

    Kohl, Niklas

    1995-01-01

    a number of generalizations of the VRPTW are considered. We discuss complex routing problems with different constraints as well as important real world scheduling problems arising in transportation companies. We show how these problems can be modelled in the same framework as the VRPTW. This means......This dissertation presents a number of optimization methods for the Vehicle Routing Problem with Time Windows (VRPTW). The VRPTW is a generalization of the well known capacity constrained Vehicle Routing Problem (VRP), where a fleet of vehicles based at a central depot must service a set...... of J?rnsten, Madsen and S?rensen (1986), which has been tested computationally by Halse (1992). Both methods decompose the problem into a series of time and capacity constrained shotest path problems. This yields a tight lower bound on the optimal objective, and the dual gap can often be closed...

  20. Carbon nanofiber supercapacitors with large areal capacitances

    KAUST Repository

    McDonough, James R.

    2009-01-01

    We develop supercapacitor (SC) devices with large per-area capacitances by utilizing three-dimensional (3D) porous substrates. Carbon nanofibers (CNFs) functioning as active SC electrodes are grown on 3D nickel foam. The 3D porous substrates facilitate a mass loading of active electrodes and per-area capacitance as large as 60 mg/ cm2 and 1.2 F/ cm2, respectively. We optimize SC performance by developing an annealing-free CNF growth process that minimizes undesirable nickel carbide formation. Superior per-area capacitances described here suggest that 3D porous substrates are useful in various energy storage devices in which per-area performance is critical. © 2009 American Institute of Physics.

  1. A high performance, variable capacitance accelerometer

    Science.gov (United States)

    Wilner, L. Bruce

    1988-12-01

    A variable capacitance acceleration sensor is described. Manufactured using silicon microfabrication techniques, the sensor uses a midplane, flat plate suspension, gas damping, and overrange stops. The sensor is assembled from three silicon wafers, using anodic bonds to inlays of borosilicate glass. Typical sensor properties are 7-pF active capacitance, 3-pF tare capacitance, a response of 0.05 pF/G, a resonance frequency of 3.4 kHz, and damping 0.7 critical. It is concluded that this sensor, with appropriate electronics, forms an accelerometer with an order-of-magnitude greater sensitivity-bandwidth product than a comparable piezoresistive acclerometer, and with extraordinary shock resistance.

  2. Microphonics in biopotential measurements with capacitive electrodes.

    Science.gov (United States)

    Luna-Lozano, Pablo S; Pallas-Areny, Ramon

    2010-01-01

    Biopotential measurements with capacitive electrodes do not need any direct contact between electrode and skin, which saves the time devoted to expose and prepare the contact area when measuring with conductive electrodes. However, mechanical vibrations resulting from physiological functions such as respiration and cardiac contraction can change the capacitance of the electrode and affect the recordings. This transformation of mechanical vibrations into undesired electric signals is termed microphonics. We have evaluated microphonics in capacitive ECG recordings obtained from a dressed subject seated on a common chair with electrodes placed on the front side of the backrest of the chair. Depending on the softness of the backrest, the recordings may be clearly affected by the displacement of the thorax back wall due to the respiration and to the heart's mechanical activity.

  3. Experimental study of negative capacitance in LEDs

    Institute of Scientific and Technical Information of China (English)

    FENG Lie-feng; WANG Jun; ZHU Chuan-yun; CONG Hong-xia; CHEN Yong; WANG Cun-da

    2005-01-01

    The experimental study on negative capacitance(NC) of various light-emitting diodes(LEDs) is presented.Experimental result shows that all LEDs display the NC phenomenon.The voltage modulated electroluminescence(VMEL) experiment confirms that the reason of negative capacitance is the strong recombination of the injected carriers in the active region of luminescence.The measures also verify that the dependence of NC on voltage and frequency in different LEDs is similar: NC phenomenon is more obvious with higher voltage or lower frequency.

  4. Design and simulation of MEMS capacitive magnetometer

    Science.gov (United States)

    Jyoti, Aditi, Tripathi, C. C.; Gopal, Ram

    2016-04-01

    This paper presents the design and simulation of a MEMS Capacitive Magnetometer using FEM (Finite Element Method) tool COMSOL Multiphysics 4.3b and results from this simulation are closely matched with analytically calculated results. A comb drive structure is used for actuation purpose which operates at resonant frequency of device is 11.791 kHz to achieve maximum displacement. A magnetic field in z-axis can be detected by this comb drive structure. Quality factor of MEMS capacitive magnetometer obtained is 18 and it has good linear response in the magnetic field range of 100 µT.

  5. Research on Cluster-based Trust Routing Protocol in Vehicle Ad Hoc Network%基于分簇的车载自组网可信路由协议研究

    Institute of Scientific and Technical Information of China (English)

    陈根乐; 樊秀梅

    2013-01-01

    Focused on the security issues about clustering routing protocol which is more suitable for VANET(vehicular Ad Hoc network),a trust routing of the clustering algorithm which took weights into consideration was proposed. The algorithm takes the situation of the nodes’ sending and receiving data packets during a period of communications as the reputation value. When processing the cluster head,the nodes’ reputation value is an important weighting factor.The timely changes of the reputation value can help exclude the low credit nodes from the communications. The cooperation of trust weight and reputation value can lead to safer VANET and lower load. Simulations show that the improved algorithm,compared with WCA,has a better ability to counter selfish nodes.%针对较适用于车载自组网的分簇式路由协议的安全问题,提出一种基于分簇的可信路由算法,即在簇头选择过程根据权重因子进行筛选。该算法将节点通信过程中在一定时间内收发数据包的好坏程度作为其信誉值,在选择簇头过程中将节点的信誉值作为重要的权重因子,由于通信过程中信誉值实时更新,可将低于信誉阀值的节点剔除,从而达到安全目的,实现了在车载自组网中的可信路由。实验结果表明,该算法较WCA(weighted clustering algorithm)算法具有较高的抵抗自私节点的能力。

  6. Stop_times based Routing Protocol for VANET

    OpenAIRE

    Moawad, Hafez; Shaaban, Eman; Fayed, Zaki Taha

    2013-01-01

    Vehicular Ad hoc Network (VANET) is a special class of Mobile Ad hoc Network (MANET) where vehicles are considered as MANET nodes with wireless links. The key difference of VANET and MANET is the special mobility pattern and rapidly changeable topology. There has been significant interest in improving safety and traffic efficiency using VANET. The design of routing protocols in VANET is important and necessary issue for support the smart ITS. Existing routing protocols of MANET are not suitab...

  7. Dynamic Routing of Short Transfer Baggage

    DEFF Research Database (Denmark)

    Clausen, Tommy; Pisinger, David

    We consider a variant of the Vehicle Routing Problem that arises in airports when transporting baggage for passengers with connecting flights. Each bag can be delivered in two locations with disjunctive time windows. The task is to define multiple trips for the vehicles in order to deliver bags...... that arrive continuously during the day. We present an IP model of the problem and describe the problem as a case study from a real life setting. We present a weighted greedy algorithm for dispatching vehicles that works in an dynamic context, meaning that it only considers bags available at the time...... of dispatch. Computational results are presented for real-life passenger data with stochastic bag arrival times and travel times. The results indicate that the algorithm is able to dispatch the baggage considerably better than the manual delivery plans reported in the case study, and due to its fast running...

  8. A route-based decomposition for the Multi-Commodity k-splittable Maximum Flow Problem

    DEFF Research Database (Denmark)

    Gamst, Mette

    2012-01-01

    The Multi-Commodity k-splittable Maximum Flow Problem routes flow through a capacitated graph such that each commodity uses at most k paths and such that the total amount of routedflow is maximized. This paper proposes a branch-and-price algorithm based on a route-based Dantzig-Wolfe decomposition......, where a route consists of up to k paths. Computational results show that the new algorithm has best performance on seven benchmark instances and is capable of solving two previously unsolved instances....

  9. Development of a 3D capacitive gyroscope with reduced parasitic capacitance

    International Nuclear Information System (INIS)

    We present the development of a technological platform dedicated to 3D capacitive inertial sensors. The proof of concept will be made on a 3D gyroscope. The mobile structure is made within a 30 µm thick Si top layer of a SOI substrate, while poly-Si deposited on top of a sacrificial PSG layer serves as suspended top electrodes and connection wires. This technology enables us to maintain low parasitic capacitance, which is of paramount significance for capacitive detection. After packaging and association with an analogue electronic board, functionality of the sensor is demonstrated. (paper)

  10. Inferring Groups of Objects, Preferred Routes, and Facility Locations from Trajectories

    DEFF Research Database (Denmark)

    Ceikute, Vaida

    driving preferences of local drivers. We first propose a framework that enables the comparison of routes provided by routing services with the actual driving behaviors of local drivers. The proposed framework includes methods that enable the use of GPS data to identify and compare routes. An evaluation...... done with real vehicle trajectory data and an existing online routing service shows that local drivers take diverse routes and that their preferred routes differ from the ones proposed by the routing service. Next, we propose a routing service that exploits historical route usage data from local......In today’s society, GPS-enabled devices are used widely. A broad range of location-based services (LBS) allow users to receive and share information related to their positions. Thus, it is possible to accumulate GPS data, and it is expected that the amount of available GPS data will increase very...

  11. Ambient-processable high capacitance hafnia-organic self-assembled nanodielectrics.

    Science.gov (United States)

    Everaerts, Ken; Emery, Jonathan D; Jariwala, Deep; Karmel, Hunter J; Sangwan, Vinod K; Prabhumirashi, Pradyumna L; Geier, Michael L; McMorrow, Julian J; Bedzyk, Michael J; Facchetti, Antonio; Hersam, Mark C; Marks, Tobin J

    2013-06-19

    Ambient and solution-processable, low-leakage, high capacitance gate dielectrics are of great interest for advances in low-cost, flexible, thin-film transistor circuitry. Here we report a new hafnium oxide-organic self-assembled nanodielectric (Hf-SAND) material consisting of regular, alternating π-electron layers of 4-[[4-[bis(2-hydroxyethyl)amino]phenyl]diazenyl]-1-[4-(diethoxyphosphoryl) benzyl]pyridinium bromide) (PAE) and HfO2 nanolayers. These Hf-SAND multilayers are grown from solution in ambient with processing temperatures ≤150 °C and are characterized by AFM, XPS, X-ray reflectivity (2.3 nm repeat spacing), X-ray fluorescence, cross-sectional TEM, and capacitance measurements. The latter yield the largest capacitance to date (1.1 μF/cm(2)) for a solid-state solution-processed hybrid inorganic-organic gate dielectric, with effective oxide thickness values as low as 3.1 nm and have gate leakage 0.2 mm(2)) on Hf-SAND (6.5 nm thick) achieve mA on currents at ultralow gate voltages (nanodielectric. High-temperature annealing in ambient (400 °C) has limited impact on Hf-SAND leakage densities (<10(-6) A/cm(2) at ±2 V) and enhances Hf-SAND multilayer capacitance densities to nearly 1 μF/cm(2), demonstrating excellent compatibility with device postprocessing methodologies. These results represent a significant advance in hybrid organic-inorganic dielectric materials and suggest synthetic routes to even higher capacitance materials useful for unconventional electronics.

  12. A Reliable Routing Protocol for Wireless Vehicular Networks

    Directory of Open Access Journals (Sweden)

    Mohsen Madani

    2012-07-01

    Full Text Available Recently, much attention has been paid to Vehicular Ad hoc Network (VANET. VANETs address direct communication between vehicle-to-vehicle and vehicles to roadside units (RSUs. They are similar to the Mobile and Ad hoc Networks (MANET in their rapid and dynamic network topology changes due to the fast motion of nodes. High mobility of nodes and network resources limitations have made the routing, one of the most important challenges in VANET researches. Therefore, guaranteeing a stable and reliable routing algorithm over VANET is one of the main steps to realize an effective vehicular communications. In this paper, a two-step AODV-based routing protocol is proposed for VANET networks. At first, node-grouping is done using their mobility information such as speed and movement direction. If the first step cannot respond efficiently, the algorithm enters the second step which uses link expiration time (LET information in the formation of the groups. The goal of the proposed protocol is increasing the stability of routing algorithm by selecting long-lived routes and decreasing link breakages. The comparison of proposed algorithm with AODV and DSR protocols is performed via the Network Simulator NS-2. It is shown that the proposed algorithm increases the delivery ratio and also decreases the routing control overhead.

  13. Improving Reactive Ad Hoc Routing Performance by Geographic Route Length

    Institute of Scientific and Technical Information of China (English)

    CAO Yuan-da; YU Yan-bing; LU Di

    2005-01-01

    In order to help reactive ad hoc routing protocols select better-performance routes, a novel metric named geographic route length (GRL) is proposed. The relationship between GRL metric and routing performance is analyzed in detail. Combined with hop metric, GRL is applied into the original ad hoc on-demand distance vector (AODV) to demonstrate its effectiveness. Simulation experiments have shown that GRL can effectively reduce packet delay and route discovery frequency, thus can improve reactive ad hoc routing performance.

  14. A New Route Maintenance in Dynamic Source Routing Protocol

    CERN Document Server

    Shukla, Ashish

    2010-01-01

    Mobile ad-hoc network (MANET) is infrastructureless, self-organizable, multi hop packet switched network. A number of routing protocols for MANETs have been proposed in recent years. Dynamic Source Routing (DSR) protocol is one of the most popular routing protocol for ad hoc networks. This paper presents a novel method to enhance route maintenance part of DSR protocol. Our proposed route maintenance significantly increases the efficiency of the protocol at the time of route failures.

  15. Quantum capacitance of the armchair-edge graphene nanoribbon

    Indian Academy of Sciences (India)

    Ling-Feng Mao

    2013-08-01

    The quantum capacitance, an important parameter in the design of nanoscale devices, is derived for armchair-edge single-layer graphene nanoribbon with semiconducting property. The quantum capacitance oscillations are found and these capacitance oscillations originate from the lateral quantum confinement in graphene nanoribbon. Detailed studies of the capacitance oscillations demonstrate that the local channel electrostatic potential at the capacitance peak, the height and the number of the capacitance peak strongly depend on the width, especially a few nanometres, of the armchair-edge graphene nanoribbon. It implies that the capacitance oscillations observed in the experiments can be utilized to measure the width of graphene nanoribbon. The results also show that the capacitance oscillations are not seen when the width is larger than 30 nm.

  16. Analysis of mutual capacitance and inductance of printed circuit

    OpenAIRE

    Ivanov, V. G.

    2014-01-01

    The article analyzes the mutual capacitance and inductance of printed circuit and introduces an evaluation technique for conductor-to-conductor capacitance under electrical connections tracing, the technique based on a multi-layer channel model.

  17. Observation of Quantum Capacitance of individual single walled carbon nanotubes

    OpenAIRE

    Dai, Junfeng; Li, Jun; Zeng, Hualing; Cui, Xiaodong

    2008-01-01

    We report a measurement on quantum capacitance of individual semiconducting and small band gap SWNTs. The observed quantum capacitance is remarkably smaller than that originating from density of states and it implies a strong electron correlation in SWNTs.

  18. Understanding individual routing behaviour.

    Science.gov (United States)

    Lima, Antonio; Stanojevic, Rade; Papagiannaki, Dina; Rodriguez, Pablo; González, Marta C

    2016-03-01

    Knowing how individuals move between places is fundamental to advance our understanding of human mobility (González et al. 2008 Nature 453, 779-782. (doi:10.1038/nature06958)), improve our urban infrastructure (Prato 2009 J. Choice Model. 2, 65-100. (doi:10.1016/S1755-5345(13)70005-8)) and drive the development of transportation systems. Current route-choice models that are used in transportation planning are based on the widely accepted assumption that people follow the minimum cost path (Wardrop 1952 Proc. Inst. Civ. Eng. 1, 325-362. (doi:10.1680/ipeds.1952.11362)), despite little empirical support. Fine-grained location traces collected by smart devices give us today an unprecedented opportunity to learn how citizens organize their travel plans into a set of routes, and how similar behaviour patterns emerge among distinct individual choices. Here we study 92 419 anonymized GPS trajectories describing the movement of personal cars over an 18-month period. We group user trips by origin-destination and we find that most drivers use a small number of routes for their routine journeys, and tend to have a preferred route for frequent trips. In contrast to the cost minimization assumption, we also find that a significant fraction of drivers' routes are not optimal. We present a spatial probability distribution that bounds the route selection space within an ellipse, having the origin and the destination as focal points, characterized by high eccentricity independent of the scale. While individual routing choices are not captured by path optimization, their spatial bounds are similar, even for trips performed by distinct individuals and at various scales. These basic discoveries can inform realistic route-choice models that are not based on optimization, having an impact on several applications, such as infrastructure planning, routing recommendation systems and new mobility solutions. PMID:26962031

  19. Thermodynamic cycle analysis for capacitive deionization

    NARCIS (Netherlands)

    Biesheuvel, P.M.

    2009-01-01

    Capacitive deionization (CDI) is an ion removal technology based on temporarily storing ions in the polarization layers of two oppositely positioned electrodes. Here we present a thermodynamic model for the minimum work required for ion separation in the fully reversible case by describing the ionic

  20. Capacitive Proximity Sensors With Additional Driven Shields

    Science.gov (United States)

    Mcconnell, Robert L.

    1993-01-01

    Improved capacitive proximity sensors constructed by incorporating one or more additional driven shield(s). Sensitivity and range of sensor altered by adjusting driving signal(s) applied to shield(s). Includes sensing electrode and driven isolating shield that correspond to sensing electrode and driven shield.

  1. Phase-Discriminating Capacitive Sensor System

    Science.gov (United States)

    Vranish, John M.; Rahim, Wadi

    1993-01-01

    Crosstalk eliminated by maintaining voltages on all electrodes at same amplitude, phase, and frequency. Each output feedback-derived control voltage, change of which indicates proximity-induced change in capacitance of associated sensing electrode. Sensors placed close together, enabling imaging of sort. Images and/or output voltages used to guide robots in proximity to various objects.

  2. Capacitive Displacement Sensor With Frequency Readout

    Science.gov (United States)

    Fritsch, Klaus

    1989-01-01

    Simple displacement-measuring circuit senses capacitance between two parallel conducting plates and produces output signal, with frequency proportional to distance between plates. Principle of circuit provides advantages over other methods because of frequency-encoded output and high linearity. Used to measure displacements.

  3. Site Specific Evaluation of Multisensor Capacitance Probes

    Science.gov (United States)

    Multisensor capacitance probes (MCPs) are widely used for measuring soil water content (SWC) at the field scale. Although manufacturers supply a generic MCP calibration, many researchers recognize that MCPs should be calibrated for specific field conditions. MCPs measurements are typically associa...

  4. Capacitors and Resistance-Capacitance Networks.

    Science.gov (United States)

    Balabanian, Norman; Root, Augustin A.

    This programed textbook was developed under a contract with the United States Office of Education as Number 5 in a series of materials for use in an electrical engineering sequence. It is divided into three parts--(1) capacitors, (2) voltage-current relationships, and (3) simple resistance-capacitance networks. (DH)

  5. Negative capacitance in multidomain ferroelectric superlattices

    Science.gov (United States)

    Zubko, Pavlo; Wojdeł, Jacek C.; Hadjimichael, Marios; Fernandez-Pena, Stéphanie; Sené, Anaïs; Luk’Yanchuk, Igor; Triscone, Jean-Marc; Íñiguez, Jorge

    2016-06-01

    The stability of spontaneous electrical polarization in ferroelectrics is fundamental to many of their current applications, which range from the simple electric cigarette lighter to non-volatile random access memories. Research on nanoscale ferroelectrics reveals that their behaviour is profoundly different from that in bulk ferroelectrics, which could lead to new phenomena with potential for future devices. As ferroelectrics become thinner, maintaining a stable polarization becomes increasingly challenging. On the other hand, intentionally destabilizing this polarization can cause the effective electric permittivity of a ferroelectric to become negative, enabling it to behave as a negative capacitance when integrated in a heterostructure. Negative capacitance has been proposed as a way of overcoming fundamental limitations on the power consumption of field-effect transistors. However, experimental demonstrations of this phenomenon remain contentious. The prevalent interpretations based on homogeneous polarization models are difficult to reconcile with the expected strong tendency for domain formation, but the effect of domains on negative capacitance has received little attention. Here we report negative capacitance in a model system of multidomain ferroelectric–dielectric superlattices across a wide range of temperatures, in both the ferroelectric and paraelectric phases. Using a phenomenological model, we show that domain-wall motion not only gives rise to negative permittivity, but can also enhance, rather than limit, its temperature range. Our first-principles-based atomistic simulations provide detailed microscopic insight into the origin of this phenomenon, identifying the dominant contribution of near-interface layers and paving the way for its future exploitation.

  6. Inside-out electrical capacitance tomography

    DEFF Research Database (Denmark)

    Kjærsgaard-Rasmussen, Jimmy; Meyer, Knud Erik

    2011-01-01

    In this work we demonstrate the construction of an ‘inside-out’ sensor geometry for electrical capacitance tomography (ECT). The inside-out geometry has the electrodes placed around a tube, as usual, but measuring ‘outwards’. The flow between the electrodes and an outer tube is reconstructed...

  7. The IRUV Protocol: Intelligent Routing Protocol In Urban Environment For Vanet

    OpenAIRE

    My Driss Laanaoui; Pr. Said RAGHAY

    2012-01-01

    Future Intelligent Transportation Systemsrequire fast and reliable communication between cars(vehicle-to-vehicle V2V) or between a car and a roadside unit (vehicle-to-infrastructure). The fundamentalcomponent for the success of Vehicular Ad-hocNetworks (VANET) applications is routing.In this paper we propose a VANET routingprotocol that is especially designed for cityenvironments. This protocol is based on thelocalization of the node, the cost assigned to thesection and score for each vehicle...

  8. Dahomey Breeding Bird Survey Route

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Document contains route directions and map for the naitonal Dahomey BBS route. Includes milage for where specific listening stations are located along the route...

  9. Anisotropic magneto-capacitance in ferromagnetic-plate capacitors

    OpenAIRE

    Haigh, J. A.; Ciccarelli, C; Betz, A. C.; Irvine, A; Novák, V.; Jungwirth, T.; Wunderlich, J.

    2015-01-01

    The capacitance of a parallel plate capacitor can depend on applied magnetic field. Previous studies have identified capacitance changes induced via classical Lorentz force or spin-dependent Zeeman effects. Here we measure a magnetization direction dependent capacitance in parallel-plate capacitors where one plate is a ferromagnetic semiconductor, gallium manganese arsenide. This anisotropic magneto-capacitance is due to the anisotropy in the density of states dependent on the magnetization t...

  10. Membrane capacitance techniques to monitor granule exocytosis in neutrophils.

    OpenAIRE

    Lollike, K; Lindau, M

    1999-01-01

    Cell membranes behave like electrical capacitors and changes in cell capacitance therefore reflect changes in the cell area. Monitoring capacitance can thus be used to study dynamic cellular phenomenon involving rapid changes in cell surface, such as exo- and/or endocytosis. In this review focus is on the use of capacitance techniques to study exocytosis in human neutrophils. We compare the whole-cell and the cell-attached capacitance techniques, and we review the complete literature dealing ...

  11. Negative Quantum Capacitance of Carbon Nanotube Field-Effect Transistors

    OpenAIRE

    Latessa, L.; Pecchia, A.; Di Carlo, A.; P. Lugli

    2004-01-01

    Atomistic density functional theory (DFT) calculations of the capacitance between a metallic cylindric gate and a carbon nanotube (CNT) are reported. Results stressing the predominant effect of quantum capacitance in limiting or even enhancing screening properties of the CNT are shown. Other contributions to the quantum capacitance beyond the electronic density of state (DOS) are pointed out. Negative values of the quantum capacitance are obtained for low-density systems, which correspondingl...

  12. Sleep-Route: Routing through Sleeping Sensors

    OpenAIRE

    Sarkar, Chayan; Rao, Vijay S.; Prasad, R. Venkatesha

    2014-01-01

    In this article, we propose an energy-efficient data gathering scheme for wireless sensor network called Sleep-Route, which splits the sensor nodes into two sets - active and dormant (low-power sleep). Only the active set of sensor nodes participate in data collection. The sensing values of the dormant sensor nodes are predicted with the help of an active sensor node. Virtual Sensing Framework (VSF) provides the mechanism to predict the sensing values by exploiting the data correlation among ...

  13. MOS Capacitance-Voltage Characteristics:V.Methods to Enhance the Trapping Capacitance

    Institute of Scientific and Technical Information of China (English)

    揭斌斌; 薩支唐

    2012-01-01

    Low-frequency and High-frequency Capacitance-Voltage (C-V) curves of Silicon Metal-Oxide-Semiconductor Capacitors,showing electron and hole trapping at shallow-level dopant and deep-level generationrecombination-trapping impurities,are presented to illustrate the enhancement of the giant trapping capacitances by physical means via device and circuit designs,in contrast to chemical means via impurity characteristics previously reported.Enhancement is realized by masking the electron or/and hole storage capacitances to make the trapping capacitances dominant at the terminals.Device and materials properties used in the computed CV curves are selected to illustrate experimental realizations for fundamental trapping parameter characterizations and for electrical and optical signal processing applications.

  14. Winding Capacitance Dividing Method for Powerformer

    Institute of Scientific and Technical Information of China (English)

    TIAN Qing; LIN Xiang-ning; LI Jian-jian; TAO Yong-hong

    2008-01-01

    It presents a method which can equivalently arrange the capacitance distribution along with the winding ofthe generator on the terminal and neutral respectively in a reasonable partition, particularly for a type of high-voltagegraded insulated cable wound generator, Powerformer. The winding of the Powerformer adopts graded insulation,which leads to the various cable thicknesses in different portion of the winding, and thus, the uneven capacitancedistribution. The large capacitive currents and large transient outrush currents resulting from the cable consisting ofthe stator winding of Powerformer may cause problems to the generator differential protection. Most of literatures a-vailable in the field of compensated differential protection focus on the charging current compensation for long trans-mission line, instead of for generator. The authors give a method which can be used to compensate the capacitivecurrent wholly to improve the reliability of the differential protection of Powerformer. It is proved that the distribu-ted capacitance can be equivalent as the lump circuit with a capacitance partition coefficient p, and p is proved as aconstant no matter whether the generator experiences the normal operation, external phase(s) fault or internal phase(s) fault. The formula of the partition coefficient is provided and the corresponding equivalent circuit of the Power-former cable to calculate capacitance currents is given. An analysis programming resolving the minimum value of thecoefficient p is written in MATLAB 7. 0/m according to this formula, using the function fmincon() which can workin any type of constraint condition. The program always gets the same global minimum points under the different in-itial values condition which proves our point by mathematical test. With this new approach to winding capacitancedividing method, the protection scheme used for Powerformer can be validated and improved accordingly.

  15. Electric field theory and the fallacy of void capacitance

    OpenAIRE

    McAllister, Iain Wilson

    1991-01-01

    The concept of the capacitance of a gaseous void is discussed as applied to electrical insulation science. The most pertinent aspect of the capacitance definition is that of reference to a single-valued potential difference between surfaces. This implies that these surfaces must be surfaces of equipotential. With this essential characteristics the validity of void capacitance is examined

  16. SEEDAL: SECURE, ENERGY-EFFICIENT, DELAY-AWARE, AND LIFETIME-BALANCING ROUTING PROTOCOL FOR HETEROGENEOUS WIRELESS SENSOR NETWORKS

    OpenAIRE

    Ms. Arya R*, Dr. N. K. Sakthivel

    2016-01-01

    The latest research  on Open Vehicle Routing (OVR) problems, a dynamic territory in operational research depends upon some features  and requirements which can be contrasted with requirements in Wireless Sensor Networks domain. According to this perception, the computational overheads in Open Vehicle Routing can be compared to Routing problems in Wireless Sensor Network. To show that this methodology is possible, one data collection protocol called EDAL, was developed.  The con...

  17. Class network routing

    Science.gov (United States)

    Bhanot, Gyan; Blumrich, Matthias A.; Chen, Dong; Coteus, Paul W.; Gara, Alan G.; Giampapa, Mark E.; Heidelberger, Philip; Steinmacher-Burow, Burkhard D.; Takken, Todd E.; Vranas, Pavlos M.

    2009-09-08

    Class network routing is implemented in a network such as a computer network comprising a plurality of parallel compute processors at nodes thereof. Class network routing allows a compute processor to broadcast a message to a range (one or more) of other compute processors in the computer network, such as processors in a column or a row. Normally this type of operation requires a separate message to be sent to each processor. With class network routing pursuant to the invention, a single message is sufficient, which generally reduces the total number of messages in the network as well as the latency to do a broadcast. Class network routing is also applied to dense matrix inversion algorithms on distributed memory parallel supercomputers with hardware class function (multicast) capability. This is achieved by exploiting the fact that the communication patterns of dense matrix inversion can be served by hardware class functions, which results in faster execution times.

  18. STUDY OF VANET ROUTING PROTOCOLS FOR END TO END DELAY

    Directory of Open Access Journals (Sweden)

    Sunilkumar M. Bhagat

    2013-02-01

    Full Text Available Less than a century since the automobile was made affordable enough for the general public, hundreds of millions of vehicles now travel along highways and streets around the world. Innovations in safety, comfort, and convenience have made vast improvements in automobiles during that time, and now new technologies promise to change the face of vehicular travel once again. Vehicular ad hoc network (VANET is network which provides the communication between vehicle to vehicle for p r o v i d i n g i n f o r m a t i o n t o travelers with new features and applications that have never previously been possible. This paper focuses on vehicle to vehicle (V2V communications in VANET. Lot of research is going on for determining route between source and destination vehicles for routing the information with good packet delivery ratio. In this paper we provide a simulation and study of VANET Routing Protocols for end-to-end delay in V2V communication.

  19. Performance Improvement in Geographic Routing for Vehicular Ad Hoc Networks

    Science.gov (United States)

    Kaiwartya, Omprakash; Kumar, Sushil; Lobiyal, D. K.; Abdullah, Abdul Hanan; Hassan, Ahmed Nazar

    2014-01-01

    Geographic routing is one of the most investigated themes by researchers for reliable and efficient dissemination of information in Vehicular Ad Hoc Networks (VANETs). Recently, different Geographic Distance Routing (GEDIR) protocols have been suggested in the literature. These protocols focus on reducing the forwarding region towards destination to select the Next Hop Vehicles (NHV). Most of these protocols suffer from the problem of elevated one-hop link disconnection, high end-to-end delay and low throughput even at normal vehicle speed in high vehicle density environment. This paper proposes a Geographic Distance Routing protocol based on Segment vehicle, Link quality and Degree of connectivity (SLD-GEDIR). The protocol selects a reliable NHV using the criteria segment vehicles, one-hop link quality and degree of connectivity. The proposed protocol has been simulated in NS-2 and its performance has been compared with the state-of-the-art protocols: P-GEDIR, J-GEDIR and V-GEDIR. The empirical results clearly reveal that SLD-GEDIR has lower link disconnection and end-to-end delay, and higher throughput as compared to the state-of-the-art protocols. It should be noted that the performance of the proposed protocol is preserved irrespective of vehicle density and speed. PMID:25429415

  20. Robotic Mounted Detection System: robotics for route clearance

    Science.gov (United States)

    Hutchison, John; Klager, Gene; McCoy, Edward; Fite, David; Frederick, Brian

    2010-04-01

    Robotic Mounted Detection System (RMDS) is a government program to enable robotic control of a Husky route clearance vehicle with a mine detection sensor payload. The goal is for the operator to control the Husky and mine detection sensor from another vehicle. This program will provide the user with standard tele-operation control of the vehicle as well as semi-autonomous modes including cruise control, precision waypoint navigation with operator error correction and a visual mode allowing the operator to enter waypoints in the current video feed. The use of autonomy will be tailored to give the operator maximum control of the robotic vehicle's path while minimizing the effort required to maintain the desired route. Autonomous alterations of the path would conflict with the goal of route clearance, so waypoint navigation will allow the operator to supply offsets to counteract location errors. While following a waypoint path, the Husky will be capable of controlling its speed to maintain an operator specified distance from the control vehicle. Obstacle avoidance will be limited to protecting the mine detection sensor, leaving any decision to leave the path up to the operator. Video will be the primary navigational sensor feed to the operator, who will use an augmented steering wheel controller and computer display to control the Husky. A LADAR system will be used to detect obstacles that could damage the mine sensor and to maintain the optimal sensor orientation while the vehicle is moving. Practical issues and lessons learned during integration will be presented.

  1. Performance improvement in geographic routing for Vehicular Ad Hoc Networks.

    Science.gov (United States)

    Kaiwartya, Omprakash; Kumar, Sushil; Lobiyal, D K; Abdullah, Abdul Hanan; Hassan, Ahmed Nazar

    2014-01-01

    Geographic routing is one of the most investigated themes by researchers for reliable and efficient dissemination of information in Vehicular Ad Hoc Networks (VANETs). Recently, different Geographic Distance Routing (GEDIR) protocols have been suggested in the literature. These protocols focus on reducing the forwarding region towards destination to select the Next Hop Vehicles (NHV). Most of these protocols suffer from the problem of elevated one-hop link disconnection, high end-to-end delay and low throughput even at normal vehicle speed in high vehicle density environment. This paper proposes a Geographic Distance Routing protocol based on Segment vehicle, Link quality and Degree of connectivity (SLD-GEDIR). The protocol selects a reliable NHV using the criteria segment vehicles, one-hop link quality and degree of connectivity. The proposed protocol has been simulated in NS-2 and its performance has been compared with the state-of-the-art protocols: P-GEDIR, J-GEDIR and V-GEDIR. The empirical results clearly reveal that SLD-GEDIR has lower link disconnection and end-to-end delay, and higher throughput as compared to the state-of-the-art protocols. It should be noted that the performance of the proposed protocol is preserved irrespective of vehicle density and speed. PMID:25429415

  2. Performance Improvement in Geographic Routing for Vehicular Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Omprakash Kaiwartya

    2014-11-01

    Full Text Available Geographic routing is one of the most investigated themes by researchers for reliable and efficient dissemination of information in Vehicular Ad Hoc Networks (VANETs. Recently, different Geographic Distance Routing (GEDIR protocols have been suggested in the literature. These protocols focus on reducing the forwarding region towards destination to select the Next Hop Vehicles (NHV. Most of these protocols suffer from the problem of elevated one-hop link disconnection, high end-to-end delay and low throughput even at normal vehicle speed in high vehicle density environment. This paper proposes a Geographic Distance Routing protocol based on Segment vehicle, Link quality and Degree of connectivity (SLD-GEDIR. The protocol selects a reliable NHV using the criteria segment vehicles, one-hop link quality and degree of connectivity. The proposed protocol has been simulated in NS-2 and its performance has been compared with the state-of-the-art protocols: P-GEDIR, J-GEDIR and V-GEDIR. The empirical results clearly reveal that SLD-GEDIR has lower link disconnection and end-to-end delay, and higher throughput as compared to the state-of-the-art protocols. It should be noted that the performance of the proposed protocol is preserved irrespective of vehicle density and speed.

  3. Routed planar networks

    Directory of Open Access Journals (Sweden)

    David J. Aldous

    2016-04-01

    Full Text Available Modeling a road network as a planar graph seems very natural. However, in studying continuum limits of such networks it is useful to take {\\em routes} rather than {\\em edges} as primitives. This article is intended to introduce the relevant (discrete setting notion of {\\em routed network} to graph theorists. We give a naive classification of all 71 topologically different such networks on 4 leaves, and pose a variety of challenging research questions.

  4. Comparative assessment of spent nuclear fuel transportation routes using risk factors and a geographic information system

    International Nuclear Information System (INIS)

    The assessment of potential alternative routes was simplified through the use of six comparative risk factors evaluated using detailed, route-specific data. The route and environmental attributes varied strongly with location and were developed from national, state, and local sources. The six comparative factors were risk measures of incident-free transportation radiation exposure, radiological accident population exposure, nonradiological accidents, contamination of environmental sensitive areas, environmental justice for minority populations, and environmental justice for low-income populations. An assessment of four real North-Central Florida routes provided a sample implementation of the analysis tools and risk factors. The assessment routes, consisting of common beginning and end locations, included an interstate highway, a rural highway, a mostly urban highway, and a combination interstate highway with rural bypass. This route comparative assessment study predicted that the interstate highway, despite a higher population density, greater traffic volume, and greater number of vehicular fatality accidents, would present the lowest cumulative risk. On the contrary, the rural highway route, characterized as having the lowest population density, minimal vehicle traffic volume, and the lowest percentages of minority and low-income populations, displayed the highest cumulative risk measure. Factors contributing to the high risk for the rural highway route included greater route length, higher vehicular fatality accident rates per vehicle mile traveled, and the close proximity to environmentally sensitive areas. This route comparative assessment study predicted that the interstate highway, despite a higher population density, greater traffic volume, and greater number of vehicular fatality accidents, would present the lowest cumulative risk. On the contrary, the rural highway route, characterized as having the lowest population density, minimal vehicle traffic volume

  5. Optimization for Service Routes of Pallet Service Center Based on the Pallet Pool Mode

    Directory of Open Access Journals (Sweden)

    Kang Zhou

    2016-01-01

    Full Text Available Service routes optimization (SRO of pallet service center should meet customers’ demand firstly and then, through the reasonable method of lines organization, realize the shortest path of vehicle driving. The routes optimization of pallet service center is similar to the distribution problems of vehicle routing problem (VRP and Chinese postman problem (CPP, but it has its own characteristics. Based on the relevant research results, the conditions of determining the number of vehicles, the one way of the route, the constraints of loading, and time windows are fully considered, and a chance constrained programming model with stochastic constraints is constructed taking the shortest path of all vehicles for a delivering (recycling operation as an objective. For the characteristics of the model, a hybrid intelligent algorithm including stochastic simulation, neural network, and immune clonal algorithm is designed to solve the model. Finally, the validity and rationality of the optimization model and algorithm are verified by the case.

  6. Optimization for Service Routes of Pallet Service Center Based on the Pallet Pool Mode

    Science.gov (United States)

    He, Shiwei; Song, Rui

    2016-01-01

    Service routes optimization (SRO) of pallet service center should meet customers' demand firstly and then, through the reasonable method of lines organization, realize the shortest path of vehicle driving. The routes optimization of pallet service center is similar to the distribution problems of vehicle routing problem (VRP) and Chinese postman problem (CPP), but it has its own characteristics. Based on the relevant research results, the conditions of determining the number of vehicles, the one way of the route, the constraints of loading, and time windows are fully considered, and a chance constrained programming model with stochastic constraints is constructed taking the shortest path of all vehicles for a delivering (recycling) operation as an objective. For the characteristics of the model, a hybrid intelligent algorithm including stochastic simulation, neural network, and immune clonal algorithm is designed to solve the model. Finally, the validity and rationality of the optimization model and algorithm are verified by the case. PMID:27528865

  7. Modeling Routing Overhead Generated by Wireless Proactive Routing Protocols

    CERN Document Server

    Javaid, Nadeem; Javaid, Akmal; Malik, Shahzad A

    2011-01-01

    In this paper, we present a detailed framework consisting of modeling of routing overhead generated by three widely used proactive routing protocols; Destination-Sequenced Distance Vector (DSDV), Fish-eye State Routing (FSR) and Optimized Link State Routing (OLSR). The questions like, how these protocols differ from each other on the basis of implementing different routing strategies, how neighbor estimation errors affect broadcast of route requests, how reduction of broadcast overhead achieves bandwidth, how to cope with the problem of mobility and density, etc, are attempted to respond. In all of the above mentioned situations, routing overhead and delay generated by the chosen protocols can exactly be calculated from our modeled equations. Finally, we analyze the performance of selected routing protocols using our proposed framework in NS-2 by considering different performance parameters; Route REQuest (RREQ) packet generation, End-to-End Delay (E2ED) and Normalized Routing Load (NRL) with respect to varyi...

  8. Modeling Routing Overhead Generated by Wireless Reactive Routing Protocols

    CERN Document Server

    Javaid, Nadeem; Javaid, Akmal; Malik, Shahzad A

    2011-01-01

    In this paper, we have modeled the routing over- head generated by three reactive routing protocols; Ad-hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR) and DYnamic MANET On-deman (DYMO). Routing performed by reactive protocols consists of two phases; route discovery and route maintenance. Total cost paid by a protocol for efficient routing is sum of the cost paid in the form of energy consumed and time spent. These protocols majorly focus on the optimization performed by expanding ring search algorithm to control the flooding generated by the mechanism of blind flooding. So, we have modeled the energy consumed and time spent per packet both for route discovery and route maintenance. The proposed framework is evaluated in NS-2 to compare performance of the chosen routing protocols.

  9. A Dynamic Travel Time Estimation Model Based on Connected Vehicles

    Directory of Open Access Journals (Sweden)

    Daxin Tian

    2015-01-01

    Full Text Available With advances in connected vehicle technology, dynamic vehicle route guidance models gradually become indispensable equipment for drivers. Traditional route guidance models are designed to direct a vehicle along the shortest path from the origin to the destination without considering the dynamic traffic information. In this paper a dynamic travel time estimation model is presented which can collect and distribute traffic data based on the connected vehicles. To estimate the real-time travel time more accurately, a road link dynamic dividing algorithm is proposed. The efficiency of the model is confirmed by simulations, and the experiment results prove the effectiveness of the travel time estimation method.

  10. Porous Alumina Based Capacitive MEMS RH Sensor

    CERN Document Server

    Juhasz, L; Timar-Horvath, Veronika; Desmulliez, Marc; Dhariwal, Resh

    2008-01-01

    The aim of a joint research and development project at the BME and HWU is to produce a cheap, reliable, low-power and CMOS-MEMS process compatible capacitive type relative humidity (RH) sensor that can be incorporated into a state-of-the-art, wireless sensor network. In this paper we discuss the preparation of our new capacitive structure based on post-CMOS MEMS processes and the methods which were used to characterize the thin film porous alumina sensing layer. The average sensitivity is approx. 15 pF/RH% which is more than a magnitude higher than the values found in the literature. The sensor is equipped with integrated resistive heating, which can be used for maintenance to reduce drift, or for keeping the sensing layer at elevated temperature, as an alternative method for temperature-dependence cancellation.

  11. Automatic Power Factor Correction Using Capacitive Bank

    Directory of Open Access Journals (Sweden)

    Mr.Anant Kumar Tiwari,

    2014-02-01

    Full Text Available The power factor correction of electrical loads is a problem common to all industrial companies. Earlier the power factor correction was done by adjusting the capacitive bank manually [1]. The automated power factor corrector (APFC using capacitive load bank is helpful in providing the power factor correction. Proposed automated project involves measuring the power factor value from the load using microcontroller. The design of this auto-adjustable power factor correction is to ensure the entire power system always preserving unity power factor. The software and hardware required to implement the suggested automatic power factor correction scheme are explained and its operation is described. APFC thus helps us to decrease the time taken to correct the power factor which helps to increase the efficiency.

  12. Layer resolved capacitive probing of graphene bilayers

    Science.gov (United States)

    Zibrov, Alexander; Parmentier, François; Li, Jia; Wang, Lei; Hunt, Benjamin; Dean, Cory; Hone, James; Taniguchi, Takashi; Watanabe, Kenji; Young, Andrea

    Compared to single layer graphene, graphene bilayers have an additional ``which-layer'' degree of freedom that can be controlled by an external electric field in a dual-gated device geometry. We describe capacitance measurements capable of directly probing this degree of freedom. By performing top gate, bottom gate, and penetration field capacitance measurements, we directly extract layer polarization of both Bernal and twisted bilayers. We will present measurements of hBN encapsulated bilayers at both zero and high magnetic field, focusing on the physics of the highly degenerate zero-energy Landau level in the high magnetic field limit where spin, valley, and layer degeneracy are all lifted by electronic interactions.

  13. CMOS Integrated Capacitive DC-DC Converters

    CERN Document Server

    Van Breussegem, Tom

    2013-01-01

    This book provides a detailed analysis of all aspects of capacitive DC-DC converter design: topology selection, control loop design and noise mitigation. Readers will benefit from the authors’ systematic overview that starts from the ground up, in-depth circuit analysis and a thorough review of recently proposed techniques and design methodologies.  Not only design techniques are discussed, but also implementation in CMOS is shown, by pinpointing the technological opportunities of CMOS and demonstrating the implementation based on four state-of-the-art prototypes.  Provides a detailed analysis of all aspects of capacitive DC-DC converter design;  Analyzes the potential of this type of DC-DC converter and introduces a number of techniques to unleash their full potential; Combines system theory with practical implementation techniques; Includes unique analysis of CMOS technology for this application; Provides in-depth analysis of four fabricated prototypes.

  14. Priority-Based Routing Resource Assignment Considering Crosstalk

    Institute of Scientific and Technical Information of China (English)

    Yi-Ci Cai; Bin Liu; Yan Xiong; Qiang Zhou; Xian-Long Hong

    2006-01-01

    Crosstalk has become one of the most critical concerns in very deep sub-micron era. This paper deals with the problem of crosstalk mitigation at both methodological and algorithmic levels. Noting that intermediate operations between global routing and detailed routing are very effective in crosstalk estimation and reduction, the authors propose to incorporate several intermediate steps that are separated in traditional design flow into an integrated routing resource assignment stage,so that the operations could easily cooperate to fully exert their power on crosstalk reduction. An efficient priority-based heuristic algorithm is developed, which works slice by slice. Crosstalk avoidance, and many other aspects that are critical in routing practice including congestion, vias, layer preference, etc., are taken into account. A track reservation strategy is adopted in the algorithm framework to compensate the undesired effects caused by sequential routing. Experimental results on a series of ISPD98 and industrial benchmarks show that the proposed approach is able to reduce capacitive crosstalk by about 70% on average without compromising completion ratio compared with a previously reported graph based algorithm,demonstrating the advantages of the approach.

  15. Performance relations in Capacitive Deionization systems

    OpenAIRE

    Limpt, van, C.

    2010-01-01

    Capacitive Deionization (CDI) is a relatively new deionization technology based on the temporary storage of ions on an electrically charged surface. By directing a flow between two oppositely charged surfaces, negatively charged ions will adsorb onto the positively charged surface, and positively charged ions will adsorb onto the negatively charged surface. To optimize CDI design for various applications, performance relations in CDI systems have to be understood. CDI performance is determine...

  16. THERMAL DRIFT CHARACTERISTICS OF CAPACITIVE PRESSURE SENSORS

    OpenAIRE

    ABDELAZIZ BEDDIAF; FOUAD KERROUR; SALAH KEMOUCHE

    2016-01-01

    The capacitive pressure sensors based on silicon are characterized by their very high sensitivities and their low power consumption. Nevertheless, their thermal behavior remains more or less unpredictable because they can indicate very high thermal coefficients. The study of the thermal behavior of these sensors is essential to define the parameters that cause the output characteristics drift. In this study, we modeled the thermal behavior of this sensors, using Finite Element Analysis (FE...

  17. Ultra-High-Frequency Capacitive Displacement Sensor

    Science.gov (United States)

    Vanzandt, Thomas R.; Kenny, Thomas W.; Kaiser, William J.

    1994-01-01

    Improved class of compact, high-resolution capacitive displacement sensors operates at excitation frequency of 915 MHz and measures about 7.5 by 4 by 2 centimeters. Contains commercially available 915-MHz oscillator and transmission-line resonator. Resonator contains stripline inductor in addition to variable capacitor. Ultrahigh excitation frequency offers advantages of resolution and frequency response. Not deleteriously affected by mechanical overdriving, or contact between electrodes.

  18. Capacitive Sensors And Targets Would Measure Alignments

    Science.gov (United States)

    Jenstrom, Del T.

    1994-01-01

    Multiple capacitive sensors and active targets used to measure distance between, and relative orientation of, two objects. Sensed target signals processed and used by control systems to align objects to be joined. Shapes, sizes, and layouts of sensors and targets optimized for specific application. Particular layout of targets and sensors enables determination of relative position and orientation of two objects in all six degrees of freedom.

  19. Development of a capacitive bioimpedance measurement system

    OpenAIRE

    Gómez Abad, Daniel

    2009-01-01

    Bioelectrical impedance spectroscopy (BIS) is a well-established and non-invasive method to determine and monitor body composition. Commercially available bioelectrical impedance systems use coated hydrogel-aluminium electrodes, where the hydrogel acts as an adhesive and as an electrolytic medium. The gel/adhesive is physiologically inert over short periods. However, when used over longer periods, hydrogel-aluminium electrodes present limitations, which capacitive electrodes ma...

  20. The fringe capacitance formula of microstructures

    International Nuclear Information System (INIS)

    This paper presents a fringe capacitance formula of microstructures. The formula is derived by curve fitting on ANSYS simulation results. Compared with the ANSYS and experimental results, the deviation is within ±2%. The application to determine the pull-in voltage of an electrostatic micro-beam is demonstrated, which agrees very well with the experimental data. The formula presented is very accurate, yields explicit physical meanings and is applicable to common dimension ranges for MEMS devices. (paper)

  1. Evaluation of EHD films by electrical capacitance

    Science.gov (United States)

    Jablonka, Karolina; Glovnea, Romeo; Bongaerts, Jeroen

    2012-09-01

    The elastohydrodynamic (EHD) lubrication regime occurs in many machine elements where a combination of hydrodynamic effect, elastic deformation of the loaded surfaces and increase in the viscosity of the lubricant with pressure ensures the formation of a very thin, but continuous film of lubricant separating the contacting surfaces. Electrical methods to determine this film's thickness have preceded optical methods, which are widely used today. Although they generally give more qualitative thickness information, electrical methods have the main advantage that they can be applied to metallic contacts in machines, which makes them useful tools in the study of elastohydrodynamically lubricated contacts. This paper is part of a larger study on the application of electrical capacitance for the evaluation of film formation in EHD contacts. The main focus is on the quantitative measurements of film thickness using electrical capacitance. A new approach allowing the lubricant film thickness to be extracted from the measured capacitance is developed using a chromium-coated glass disc and subsequently applied to a steel-on-steel contact. The results show good agreement with optical measurements and theoretical models over a range of film thickness.

  2. Multi-Channel Capacitive Sensor Arrays

    Directory of Open Access Journals (Sweden)

    Bingnan Wang

    2016-01-01

    Full Text Available In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The inductive element associated with each capacitive sensor can be surface-mounted inductors, integrated microstrip inductors or metamaterial-inspired structures. We show that by using metamaterial split-ring structures coupled to a microstrip line, the quality factor of each resonance can be greatly improved compared to conventional surface-mounted or microstrip meander inductors. With such a microstrip-coupled split-ring design, more sensing elements can be integrated in the same frequency spectrum, and the sensitivity can be greatly improved.

  3. Carbon Materials for Chemical Capacitive Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Y.; Dou, Y.; Zhao, D.; Fulvio, P. F.; Mayes, R. T.; Dai, S.

    2011-09-26

    Carbon materials have attracted intense interests as electrode materials for electrochemical capacitors, because of their high surface area, electrical conductivity, chemical stability and low cost. Activated carbons produced by different activation processes from various precursors are the most widely used electrodes. Recently, with the rapid growth of nanotechnology, nanostructured electrode materials, such as carbon nanotubes and template-synthesized porous carbons have been developed. Their unique electrical properties and well controlled pore sizes and structures facilitate fast ion and electron transportation. In order to further improve the power and energy densities of the capacitors, carbon-based composites combining electrical double layer capacitors (EDLC)-capacitance and pseudo-capacitance have been explored. They show not only enhanced capacitance, but as well good cyclability. In this review, recent progresses on carbon-based electrode materials are summarized, including activated carbons, carbon nanotubes, and template-synthesized porous carbons, in particular mesoporous carbons. Their advantages and disadvantages as electrochemical capacitors are discussed. At the end of this review, the future trends of electrochemical capacitors with high energy and power are proposed.

  4. Carbon materials for chemical capacitive energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Yunpu; Zhao, Dongyuan [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Key Laboratory of Molecular Engineering of Polymers of the Chinese, Ministry of Education, Laboratory of Advanced Materials, Fudan University, Shanghai (China); Dou, Yuqian [Department of Chemistry, Northeastern University, Shenyang (China); Fulvio, Pasquale F.; Mayes, Richard T.; Dai, Sheng [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2011-11-09

    Carbon materials have attracted intense interests as electrode materials for electrochemical capacitors, because of their high surface area, electrical conductivity, chemical stability and low cost. Activated carbons produced by different activation processes from various precursors are the most widely used electrodes. Recently, with the rapid growth of nanotechnology, nanostructured electrode materials, such as carbon nanotubes and template-synthesized porous carbons have been developed. Their unique electrical properties and well controlled pore sizes and structures facilitate fast ion and electron transportation. In order to further improve the power and energy densities of the capacitors, carbon-based composites combining electrical double layer capacitors (EDLC)-capacitance and pseudo-capacitance have been explored. They show not only enhanced capacitance, but as well good cyclability. In this review, recent progresses on carbon-based electrode materials are summarized, including activated carbons, carbon nanotubes, and template-synthesized porous carbons, in particular mesoporous carbons. Their advantages and disadvantages as electrochemical capacitors are discussed. At the end of this review, the future trends of electrochemical capacitors with high energy and power are proposed. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Multi-Channel Capacitive Sensor Arrays.

    Science.gov (United States)

    Wang, Bingnan; Long, Jiang; Teo, Koon Hoo

    2016-01-01

    In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The inductive element associated with each capacitive sensor can be surface-mounted inductors, integrated microstrip inductors or metamaterial-inspired structures. We show that by using metamaterial split-ring structures coupled to a microstrip line, the quality factor of each resonance can be greatly improved compared to conventional surface-mounted or microstrip meander inductors. With such a microstrip-coupled split-ring design, more sensing elements can be integrated in the same frequency spectrum, and the sensitivity can be greatly improved. PMID:26821023

  6. Effect of astaxanthin on human sperm capacitation.

    Science.gov (United States)

    Donà, Gabriella; Kožuh, Ivana; Brunati, Anna Maria; Andrisani, Alessandra; Ambrosini, Guido; Bonanni, Guglielmo; Ragazzi, Eugenio; Armanini, Decio; Clari, Giulio; Bordin, Luciana

    2013-06-01

    In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS) plays a key role in causing cells to undergo a massive acrosome reaction (AR). Astaxanthin (Asta), a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC). Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam) and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P) pattern and percentages of ARC and non-viable cells (NVC). Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting the ROS generation curve, whereas Diam succeeded in enhancing the Tyr-P level but only of the flagellum without increasing ARC values. It is suggested that Asta can be inserted in the membrane and therefore create capacitation-like membrane alteration which allow Tyr-P of the head. Once this has occurred, AR can take place and involves a higher numbers of cells. PMID:23736766

  7. Effect of Astaxanthin on Human Sperm Capacitation

    Directory of Open Access Journals (Sweden)

    Luciana Bordin

    2013-06-01

    Full Text Available In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS plays a key role in causing cells to undergo a massive acrosome reaction (AR. Astaxanthin (Asta, a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC. Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P pattern and percentages of ARC and non-viable cells (NVC. Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting the ROS generation curve, whereas Diam succeeded in enhancing the Tyr-P level but only of the flagellum without increasing ARC values. It is suggested that Asta can be inserted in the membrane and therefore create capacitation-like membrane alteration which allow Tyr-P of the head. Once this has occurred, AR can take place and involves a higher numbers of cells.

  8. Capacitive Structures for Gas and Biological Sensing

    KAUST Repository

    Sapsanis, Christos

    2015-04-01

    The semiconductor industry was benefited by the advances in technology in the last decades. This fact has an impact on the sensors field, where the simple transducer was evolved into smart miniaturized multi-functional microsystems. However, commercially available gas and biological sensors are mostly bulky, expensive, and power-hungry, which act as obstacles to mass use. The aim of this work is gas and biological sensing using capacitive structures. Capacitive sensors were selected due to its design simplicity, low fabrication cost, and no DC power consumption. In the first part, the dominant structure among interdigitated electrodes (IDEs), fractal curves (Peano and Hilbert) and Archimedean spiral was investigated from capacitance density perspective. The investigation consists of geometrical formula calculations, COMSOL Multiphysics simulations and cleanroom fabrication of the capacitors on a silicon substrate. Moreover, low-cost fabrication on flexible plastic PET substrate was conducted outside cleanroom with rapid prototyping using a maskless laser etching. The second part contains the humidity, Volatile Organic compounds (VOCs) and Ammonia sensing of polymers, Polyimide and Nafion, and metal-organic framework (MOF), Cu(bdc)2.xH2O using IDEs and tested in an automated gas setup for experiment control and data extraction. The last part includes the biological sensing of C - reactive protein (CRP) quantification, which is considered as a biomarker of being prone to cardiac diseases and Bovine serum albumin (BSA) protein quantification, which is used as a reference for quantifying unknown proteins.

  9. Adaptive powertrain control for plugin hybrid electric vehicles

    Science.gov (United States)

    Kedar-Dongarkar, Gurunath; Weslati, Feisel

    2013-10-15

    A powertrain control system for a plugin hybrid electric vehicle. The system comprises an adaptive charge sustaining controller; at least one internal data source connected to the adaptive charge sustaining controller; and a memory connected to the adaptive charge sustaining controller for storing data generated by the at least one internal data source. The adaptive charge sustaining controller is operable to select an operating mode of the vehicle's powertrain along a given route based on programming generated from data stored in the memory associated with that route. Further described is a method of adaptively controlling operation of a plugin hybrid electric vehicle powertrain comprising identifying a route being traveled, activating stored adaptive charge sustaining mode programming for the identified route and controlling operation of the powertrain along the identified route by selecting from a plurality of operational modes based on the stored adaptive charge sustaining mode programming.

  10. Multihop Wireless Networks Opportunistic Routing

    CERN Document Server

    Zeng, Kai; Li, Ming

    2011-01-01

    This book provides an introduction to opportunistic routing an emerging technology designed to improve the packet forwarding reliability, network capacity and energy efficiency of multihop wireless networks This book presents a comprehensive background to the technological challenges lying behind opportunistic routing. The authors cover many fundamental research issues for this new concept, including the basic principles, performance limit and performance improvement of opportunistic routing compared to traditional routing, energy efficiency and distributed opportunistic routing protocol desig

  11. Collective network routing

    Science.gov (United States)

    Hoenicke, Dirk

    2014-12-02

    Disclosed are a unified method and apparatus to classify, route, and process injected data packets into a network so as to belong to a plurality of logical networks, each implementing a specific flow of data on top of a common physical network. The method allows to locally identify collectives of packets for local processing, such as the computation of the sum, difference, maximum, minimum, or other logical operations among the identified packet collective. Packets are injected together with a class-attribute and an opcode attribute. Network routers, employing the described method, use the packet attributes to look-up the class-specific route information from a local route table, which contains the local incoming and outgoing directions as part of the specifically implemented global data flow of the particular virtual network.

  12. The Adaptive Optimized Routing Protocol for Vehicular Ad-hoc Networks

    OpenAIRE

    Kunal Vikas Patil; M.R. Dhage

    2013-01-01

    The vehicular ad hoc network (VANET) is a superior newtechnology. Vehicular ad hoc network (VANET) is a subclassof MANET that is mobile ad hoc networks. Vehicular ad hocnetwork provides wireless communication among vehicles andvehicles to roadside equipments. The communication betweenvehicles is more important for safety and more probably forentertainment as well. The performance of communicationdepends on how better the routing takes place in the network.Routing of data depends on routing pr...

  13. Intelligent route surveillance

    NARCIS (Netherlands)

    Schoemaker, R.M.; Sandbrink, R.D.J.; Voorthuijsen, G.P. van

    2009-01-01

    Intelligence on abnormal and suspicious behaviour along roads in operational domains is extremely valuable for countering the IED (Improvised Explosive Device) threat. Local sensor networks at strategic spots can gather data for continuous monitoring of daily vehicle activity. Unattended intelligent

  14. Distributed Capacitive Sensor for Sample Mass Measurement

    Science.gov (United States)

    Toda, Risaku; McKinney, Colin; Jackson, Shannon P.; Mojarradi, Mohammad; Manohara, Harish; Trebi-Ollennu, Ashitey

    2011-01-01

    Previous robotic sample return missions lacked in situ sample verification/ quantity measurement instruments. Therefore, the outcome of the mission remained unclear until spacecraft return. In situ sample verification systems such as this Distributed Capacitive (DisC) sensor would enable an unmanned spacecraft system to re-attempt the sample acquisition procedures until the capture of desired sample quantity is positively confirmed, thereby maximizing the prospect for scientific reward. The DisC device contains a 10-cm-diameter pressure-sensitive elastic membrane placed at the bottom of a sample canister. The membrane deforms under the weight of accumulating planetary sample. The membrane is positioned in close proximity to an opposing rigid substrate with a narrow gap. The deformation of the membrane makes the gap narrower, resulting in increased capacitance between the two parallel plates (elastic membrane and rigid substrate). C-V conversion circuits on a nearby PCB (printed circuit board) provide capacitance readout via LVDS (low-voltage differential signaling) interface. The capacitance method was chosen over other potential approaches such as the piezoelectric method because of its inherent temperature stability advantage. A reference capacitor and temperature sensor are embedded in the system to compensate for temperature effects. The pressure-sensitive membranes are aluminum 6061, stainless steel (SUS) 403, and metal-coated polyimide plates. The thicknesses of these membranes range from 250 to 500 m. The rigid substrate is made with a 1- to 2-mm-thick wafer of one of the following materials depending on the application requirements glass, silicon, polyimide, PCB substrate. The glass substrate is fabricated by a microelectromechanical systems (MEMS) fabrication approach. Several concentric electrode patterns are printed on the substrate. The initial gap between the two plates, 100 m, is defined by a silicon spacer ring that is anodically bonded to the glass

  15. Roots and routes

    DEFF Research Database (Denmark)

    Christensen, Ann-Dorte; Jensen, Sune Qvotrup

    2011-01-01

    arguing that there is a dynamic interplay between roots and routes in people's lives. The empirical point of departure is narratives about roots and routes by ethnic minorities settled in Aalborg East, an underprivileged neighbourhood in northern Denmark. One of the main findings is a gap between the...... somewhat paradoxical finding is that it appears to be more difficult for transnational migrants to maintain their roots in the country of origin when they go back than it was to establish new roots in the host country...

  16. Torch Route Twist

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    San Francisco changes Olympic flame route due to security fears The city of San Francisco,the only North American stop for the 2008 Beijing Olympic torch,surprised thousands of supporters,demon- strators and visitors on April 9,by com- pletely changing the planned torch route at the last minute without notification. As scheduled,the torch was expected to start from the McCovey Cove in the south- east of the city at 1:00 p.m.before heading along the waterfront northbound to famous tourist spot Fisherman’s Wharf and finally

  17. Routing in Vehicular Networks: Feasibility, Modeling, and Security

    Directory of Open Access Journals (Sweden)

    Ioannis Broustis

    2008-01-01

    Full Text Available Vehicular networks are sets of surface transportation systems that have the ability to communicate with each other. There are several possible network architectures to organize their in-vehicle computing systems. Potential schemes may include vehicle-to-vehicle ad hoc networks, wired backbone with wireless last hops, or hybrid architectures using vehicle-to-vehicle communications to augment roadside communication infrastructures. Some special properties of these networks, such as high mobility, network partitioning, and constrained topology, differentiate them from other types of wireless networks. We provide an in-depth discussion on the important studies related to architectural design and routing for such networks. Moreover, we discuss the major security concerns appearing in vehicular networks.

  18. Improved capacitance sensor with variable operating frequency for scanning capacitance microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Joonhyung [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Kim, Joonhui [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Jeong, Jong-Hwa [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Lee, Euy-Kyu [Department of Physics, Myongji University, Yongin, Kyunggido 449-728 (Korea, Republic of); Seok Kim, Yong [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Kang, Chi Jung [Department of Physics, Myongji University, Yongin, Kyunggido 449-728 (Korea, Republic of); Park, Sang-il [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of)]. E-mail: park@psia.co.kr

    2005-11-15

    Scanning capacitance microscopy (SCM) has been gaining attention for its capability to measure local electrical properties in doping profile, oxide thickness, trapped charges and charge dynamics. In many cases, stray capacitance produced by different samples and measurement conditions affects the resonance frequency of a capacitance sensor. The applications of conventional SCM are critically limited by the fixed operating frequency and lack of tunability in its SCM sensor. In order to widen SCM application to various samples, we have developed a novel SCM sensor with variable operating frequency. By performing variable frequency sweep over the band of 160 MHz, the SCM sensor is tuned to select the best and optimized resonance frequency and quality factor for each sample measurement. The fundamental advantage of the new variable frequency SCM sensor was demonstrated in the SCM imaging of silicon oxide nano-crystals. Typical sensitivity of the variable frequency SCM sensor was found to be 10{sup -19} F/V.

  19. Improved capacitance sensor with variable operating frequency for scanning capacitance microscopy

    International Nuclear Information System (INIS)

    Scanning capacitance microscopy (SCM) has been gaining attention for its capability to measure local electrical properties in doping profile, oxide thickness, trapped charges and charge dynamics. In many cases, stray capacitance produced by different samples and measurement conditions affects the resonance frequency of a capacitance sensor. The applications of conventional SCM are critically limited by the fixed operating frequency and lack of tunability in its SCM sensor. In order to widen SCM application to various samples, we have developed a novel SCM sensor with variable operating frequency. By performing variable frequency sweep over the band of 160 MHz, the SCM sensor is tuned to select the best and optimized resonance frequency and quality factor for each sample measurement. The fundamental advantage of the new variable frequency SCM sensor was demonstrated in the SCM imaging of silicon oxide nano-crystals. Typical sensitivity of the variable frequency SCM sensor was found to be 10-19 F/V

  20. Development of an Autonomous Vehicle for Weed and Crop Registration

    DEFF Research Database (Denmark)

    Pedersen, Tom Søndergaard; Nielsen, Kirsten Mølgaard; Andersen, Palle;

    degree of autonomy. The vehicle is part of an autonomous information system for crop and weed registration in fields which is developed at Aalborg University and The Danish Institute of Agricultural Science. The system consists of the vehicle and a stationary base station as well as a wireless...... communication system between the two. The base station is the main interface to the farmer. Based on farmer information a route plan for data collection is created in the base station and send to the vehicle. The vehicle collects field data using two cameras one determinates the total weed pressure and one...... determinates individual species. The weed data are transmitted to the base station where weed maps are calculated. The route plan is based on a grid calculated from a priori weed spatial density knowledge. The route plan consists of a set of field coordinates; at each coordinate vehicle operations are defined...

  1. Whirlpool routing for mobility

    KAUST Repository

    Lee, Jung Woo

    2010-01-01

    We present the Whirlpool Routing Protocol (WARP), which efficiently routes data to a node moving within a static mesh. The key insight in WARP\\'s design is that data traffic can use an existing routing gradient to efficiently probe the topology, repair the routing gradient, and communicate these repairs to nearby nodes. Using simulation, controlled testbeds, and real mobility experiments, we find that using the data plane for topology maintenance is highly effective due to the incremental nature of mobility updates. WARP leverages the fact that converging flows at a destination make the destination have the region of highest traffic. We provide a theoretical basis for WARP\\'s behavior, defining an "update area" in which the topology must adjust when a destination moves. As long as packets arrive at a destination before it moves outside of the update area, WARP can repair the topology using the data plane. Compared to existing protocols, such as DYMO and HYPER, WARP\\'s packet drop rate is up to 90% lower while sending up to 90% fewer packets.

  2. SET-Routes programme

    CERN Multimedia

    Marietta Schupp, EMBL Photolab

    2008-01-01

    Dr Sabine Hentze, specialist in human genetics, giving an Insight Lecture entitled "Human Genetics – Diagnostics, Indications and Ethical Issues" on 23 September 2008 at EMBL Heidelberg. Activities in a achool in Budapest during a visit of Angela Bekesi, Ambassadors for the SET-Routes programme.

  3. SET-Routes programme

    CERN Document Server

    CERN audiovisual service

    2009-01-01

    The SET-Routes programme, launched in 2007 with the goal of attracting girls and young women to careers in science, came to an end in April this year. The result of a collaboration between EMBL, EMBO and CERN, the programme established a network of "ambassadors", women scientists who went out to talk about their careers in science at schools and universities across Europe.

  4. Multiple Attribute Decision Making Based Relay Vehicle Selection for Electric Vehicle Communication

    Directory of Open Access Journals (Sweden)

    Zhao Qiang

    2015-01-01

    Full Text Available Large-scale electric vehicle integration into power grid and charging randomly will cause serious impacts on the normal operation of power grid. Therefore, it is necessary to control the charging behavior of electric vehicle, while information transmission for electric vehicle is significant. Due to the highly mobile characteristics of vehicle, transferring information to power grid directly might be inaccessible. Relay vehicle (RV can be used for supporting multi-hop connection between SV and power grid. This paper proposes a multiple attribute decision making (MADM-based RV selection algorithm, which considers multiple attribute, including data transfer rate, delay, route duration. It takes the characteristics of electric vehicle communication into account, which can provide protection for the communication services of electric vehicle charging and discharging. Numerical results demonstrate that compared to previous algorithm, the proposed algorithm offer better performance in terms of throughput, transmission delay.

  5. Rescaling of metal oxide nanocrystals for energy storage having high capacitance and energy density with robust cycle life.

    Science.gov (United States)

    Jeong, Hyung Mo; Choi, Kyung Min; Cheng, Tao; Lee, Dong Ki; Zhou, Renjia; Ock, Il Woo; Milliron, Delia J; Goddard, William A; Kang, Jeung Ku

    2015-06-30

    Nanocrystals are promising structures, but they are too large for achieving maximum energy storage performance. We show that rescaling 3-nm particles through lithiation followed by delithiation leads to high-performance energy storage by realizing high capacitance close to the theoretical capacitance available via ion-to-atom redox reactions. Reactive force-field (ReaxFF) molecular dynamics simulations support the conclusion that Li atoms react with nickel oxide nanocrystals (NiO-n) to form lithiated core-shell structures (Ni:Li2O), whereas subsequent delithiation causes Ni:Li2O to form atomic clusters of NiO-a. This is consistent with in situ X-ray photoelectron and optical spectroscopy results showing that Ni(2+) of the nanocrystal changes during lithiation-delithiation through Ni(0) and back to Ni(2+). These processes are also demonstrated to provide a generic route to rescale another metal oxide. Furthermore, assembling NiO-a into the positive electrode of an asymmetric device enables extraction of full capacitance for a counter negative electrode, giving high energy density in addition to robust capacitance retention over 100,000 cycles.

  6. ANALYTICAL ESTIMATION OF MINIMUM AND MAXIMUM TIME EXPENDITURES OF PASSENGERS AT AN URBAN ROUTE STOP

    Directory of Open Access Journals (Sweden)

    Gorbachov, P.

    2013-01-01

    Full Text Available This scientific paper deals with the problem related to the definition of average time spent by passengers while waiting for transport vehicles at urban stops as well as the results of analytical modeling of this value at traffic schedule unknown to the passengers and of two options of the vehicle traffic management on the given route.

  7. Numerical analysis of capacitive pressure micro-sensors

    Institute of Scientific and Technical Information of China (English)

    WANG; Xiaomin; LI; Mingxuan; WANG; Chenghao

    2005-01-01

    Pseudo-spectral method is used to numerically model the diaphragm deflection of capacitive pressure micro-sensor under uniform load. The relationship between the capacitance of the micro-sensor and the load is then analyzed after the description of the computational principle. For normal mode micro-sensor, the tensile force on the diaphragm can be ignored and thereby the capacitance increases linearly with the load increase only when the load is so small that the resultant deflection is less than the diaphragm thickness. The linear relationship between the capacitance and the load turns to be nonlinear thereafter and the capacitance rises dramatically with the constant increase of the load. For touch mode micro-sensor, an algorithm to determine the touch radius of the diaphragm and substrate is presented and the curve of capacitance versus load is shown on the numerical results laying a theoretical foundation for micro-sensor design.

  8. Connectivity-Enhanced Route Selection and Adaptive Control for the Chevrolet Volt: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gonder, J.; Wood, E.; Rajagopalan, S.

    2014-09-01

    The National Renewable Energy Laboratory and General Motors evaluated connectivity-enabled efficiency enhancements for the Chevrolet Volt. A high-level model was developed to predict vehicle fuel and electricity consumption based on driving characteristics and vehicle state inputs. These techniques were leveraged to optimize energy efficiency via green routing and intelligent control mode scheduling, which were evaluated using prospective driving routes between tens of thousands of real-world origin/destination pairs. The overall energy savings potential of green routing and intelligent mode scheduling was estimated at 5% and 3% respectively. These represent substantial opportunities considering that they only require software adjustments to implement.

  9. Solving the Tractor and Semi-Trailer Routing Problem Based on a Heuristic Approach

    OpenAIRE

    Hongqi Li; Yue Lu; Jun Zhang; Tianyi Wang

    2012-01-01

    We study the tractor and semi-trailer routing problem (TSRP), a variant of the vehicle routing problem (VRP). In the TSRP model for this paper, vehicles are dispatched on a trailer-flow network where there is only one main depot, and all tractors originate and terminate in the main depot. Two types of decisions are involved: the number of tractors and the route of each tractor. Heuristic algorithms have seen widespread application to various extensions of the VRP. However, this approach has n...

  10. Accurate sizing of supercapacitors storage system considering its capacitance variation.

    OpenAIRE

    Trieste, Sony; Bourguet, Salvy; Olivier, Jean-Christophe; Loron, Luc; Le Claire, Jean-Claude

    2011-01-01

    This paper highlights the energy errors made for the design of supercapacitors used as a main energy source. First of all, the paper presents the two definitions of capacitance of a capacitance-voltage dependent material. The number of supercapacitors is important for the application purchasing cost. That is why the paper introduces an analytical model and an electrical model along with an identification method for the capacitance variation. This variation is presented and compared to the man...

  11. Nonlinear dynamics of capacitive charging and desalination by porous electrodes

    OpenAIRE

    Biesheuvel, P. M.; Bazant, M.Z.

    2010-01-01

    The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by super-capacitors, water desalination and purification by capacitive deionization (or desalination), and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or spec...

  12. Probing Quantum Capacitance in a 3D Topological Insulator

    OpenAIRE

    Kozlov, D. A.; Bauer, Dominik; Ziegler, Johannes; Fischer, Ralf, 1965-; Savchenko, M. L.; Kvon, Z.D.; Mikhailov, N. N.; Dvoretsky, S. A.; Weiss, Dieter

    2016-01-01

    We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type of two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magneto-capacitance oscillations probe, in contrast to magnetotransport, primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions ...

  13. DEVELOPMENT OF ADAPTED CAPACITANCE MANOMETER FOR  THERMOSPHERIC APPLICATIONS

    OpenAIRE

    Orr, Cameron Scott

    2016-01-01

    An adapted capacitance manometer is a sensor composed of one fixed plate and one movable plate that is able to make accurate pressure measurements in a low pressure environment. Using detection circuitry, a change in capacitance between the two plates can be measured and correlated to a differential pressure. First, a high sensitivity manometer is produced that exhibits a measurable change in capacitance when experiencing a pressure differential in a low pressure space environment. Second,...

  14. Static and Motional Feedthrough Capacitance of Flexural Microresonator

    OpenAIRE

    Wen-Teng Chang

    2011-01-01

    The present paper evaluates the static and motional feedthrough capacitance of a silicon carbide-based flexural-mode microelectromechanical system resonator. The static feedthrough capacitance was measured by a network analyzer under atmospheric pressure. The motional feedthrough was obtained by introducing various values into the modeling circuit in order to fit the Bode plots measured under reduced pressure. The static feedthrough capacitance was 0.02 pF, whereas the motional feedthrough ca...

  15. Capacitive position measurement for high-precision space inertial sensor

    Institute of Scientific and Technical Information of China (English)

    Yan-zheng BAI; Ze-bing ZHOU; Hai-bo TU; Shu-chao WU; Lin CAI; LI LIU; Jun LUO

    2009-01-01

    Low noise position measurement is fundamental for space inertial sensors, and at present the capacitive position sensor is widely employed for space inertial sensors. The design for the possible suppression of the front-end electric noises for a capacitive sensor is presented. A prototype capacitive sensor with 2x 10-6pF/Hzi/2 at frequency above 0.04 Hz is achieved and further improvements are discussed.

  16. Carrier Statistics and Quantum Capacitance Models of Graphene Nanoscroll

    Directory of Open Access Journals (Sweden)

    M. Khaledian

    2014-01-01

    schematic perfect scroll-like Archimedes spiral. The DOS model was derived at first, while it was later applied to compute the carrier concentration and quantum capacitance model. Furthermore, the carrier concentration and quantum capacitance were modeled for both degenerate and nondegenerate regimes, along with examining the effect of structural parameters and chirality number on the density of state and carrier concentration. Latterly, the temperature effect on the quantum capacitance was studied too.

  17. CMOS MEMS capacitive absolute pressure sensor

    International Nuclear Information System (INIS)

    This paper presents the design, fabrication and characterization of a capacitive pressure sensor using a commercial 0.18 µm CMOS (complementary metal–oxide–semiconductor) process and postprocess. The pressure sensor is capacitive and the structure is formed by an Al top electrode enclosed in a suspended SiO2 membrane, which acts as a movable electrode against a bottom or stationary Al electrode fixed on the SiO2 substrate. Both the movable and fixed electrodes form a variable parallel plate capacitor, whose capacitance varies with the applied pressure on the surface. In order to release the membranes the CMOS layers need to be applied postprocess and this mainly consists of four steps: (1) deposition and patterning of PECVD (plasma-enhanced chemical vapor deposition) oxide to protect CMOS pads and to open the pressure sensor top surface, (2) etching of the sacrificial layer to release the suspended membrane, (3) deposition of PECVD oxide to seal the etching holes and creating vacuum inside the gap, and finally (4) etching of the passivation oxide to open the pads and allow electrical connections. This sensor design and fabrication is suitable to obey the design rules of a CMOS foundry and since it only uses low-temperature processes, it allows monolithic integration with other types of CMOS compatible sensors and IC (integrated circuit) interface on a single chip. Experimental results showed that the pressure sensor has a highly linear sensitivity of 0.14 fF kPa−1 in the pressure range of 0–300 kPa. (paper)

  18. CMOS MEMS capacitive absolute pressure sensor

    Science.gov (United States)

    Narducci, M.; Yu-Chia, L.; Fang, W.; Tsai, J.

    2013-05-01

    This paper presents the design, fabrication and characterization of a capacitive pressure sensor using a commercial 0.18 µm CMOS (complementary metal-oxide-semiconductor) process and postprocess. The pressure sensor is capacitive and the structure is formed by an Al top electrode enclosed in a suspended SiO2 membrane, which acts as a movable electrode against a bottom or stationary Al electrode fixed on the SiO2 substrate. Both the movable and fixed electrodes form a variable parallel plate capacitor, whose capacitance varies with the applied pressure on the surface. In order to release the membranes the CMOS layers need to be applied postprocess and this mainly consists of four steps: (1) deposition and patterning of PECVD (plasma-enhanced chemical vapor deposition) oxide to protect CMOS pads and to open the pressure sensor top surface, (2) etching of the sacrificial layer to release the suspended membrane, (3) deposition of PECVD oxide to seal the etching holes and creating vacuum inside the gap, and finally (4) etching of the passivation oxide to open the pads and allow electrical connections. This sensor design and fabrication is suitable to obey the design rules of a CMOS foundry and since it only uses low-temperature processes, it allows monolithic integration with other types of CMOS compatible sensors and IC (integrated circuit) interface on a single chip. Experimental results showed that the pressure sensor has a highly linear sensitivity of 0.14 fF kPa-1 in the pressure range of 0-300 kPa.

  19. Capacitive tool standoff sensor for dismantlement tasks

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, D.J.; Weber, T.M. [Sandia National Labs., Albuquerque, NM (United States); Liu, J.C. [Univ. of Illinois, Urbana, IL (United States)

    1996-12-31

    A capacitive sensing technology has been applied to develop a Standoff Sensor System for control of robotically deployed tools utilized in Decontamination and Dismantlement (D and D) activities. The system combines four individual sensor elements to provide non-contact, multiple degree-of-freedom control of tools at distances up to five inches from a surface. The Standoff Sensor has been successfully integrated to a metal cutting router and a pyrometer, and utilized for real-time control of each of these tools. Experiments demonstrate that the system can locate stationary surfaces with a repeatability of 0.034 millimeters.

  20. Capacitive tool standoff sensor for dismantlement tasks

    International Nuclear Information System (INIS)

    A capacitive sensing technology has been applied to develop a Standoff Sensor System for control of robotically deployed tools utilized in Decontamination and Dismantlement (D and D) activities. The system combines four individual sensor elements to provide non-contact, multiple degree-of-freedom control of tools at distances up to five inches from a surface. The Standoff Sensor has been successfully integrated to a metal cutting router and a pyrometer, and utilized for real-time control of each of these tools. Experiments demonstrate that the system can locate stationary surfaces with a repeatability of 0.034 millimeters

  1. 3-D capacitance density imaging system

    Science.gov (United States)

    Fasching, G.E.

    1988-03-18

    A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved. 7 figs.

  2. Route Repetition and Route Retracing: Effects of Cognitive Aging

    Directory of Open Access Journals (Sweden)

    Jan Malte Wiener

    2012-05-01

    Full Text Available Retracing a recently traveled route is a frequent navigation task when learning novel routes or exploring unfamiliar environments. In the present study we utilized virtual environments technology to investigate age-related differences in repeating and retracing a learned route. In the training phase of the experiment participants were guided along a route consisting of multiple intersections each featuring one unique landmark. In the subsequent test phase, they were guided along short sections of the route and asked to indicate overall travel direction (repetition or retracing, the direction required to continue along the route, and the next landmark they would encounter. Results demonstrate age-related deficits in all three tasks. More specifically, in contrast to younger participants, the older participants had greater problems during route retracing than during route repetition. While route repetition can be solved with egocentric response or route strategies, successfully retracing a route requires allocentric processing. The age-related deficits in route retracing are discussed in the context of impaired allocentric processing and shifts from allocentric to egocentric navigation strategies as a consequence of age-related hippocampal degeneration.

  3. Human body capacitance: static or dynamic concept? [ESD

    DEFF Research Database (Denmark)

    Jonassen, Niels M

    1998-01-01

    A standing human body insulated from ground by footwear and/or floor covering is in principle an insulated conductor and has, as such, a capacitance, i.e. the ability to store a charge and possibly discharge the stored energy in a spark discharge. In the human body, the human body capacitance (HBC......) is traditionally chosen as 100 pF. However, a simple geometric model seems to suggest considerably higher values. A series of experiments, where the capacitance of standing persons were determined for various combinations of footwear and floor coverings, gave values in the order of 100-150 pF when the capacitance...

  4. Calibration of capacitive hydrostatic leveling sensors of NSRL

    International Nuclear Information System (INIS)

    The principle of capacitive hydrostatic leveling sensors was presented. Simulations of sensors with two kinds of materials (metal and distilled water) as target electrode in the situations of calibration and work were carried out by Ansoft Maxwell software. Different values of capacitances in different situations were compared and analyzed. Then some experiments were done with independently developed prototype of capacitive hydrostatic leveling sensors to verify the above simulations. In the situations of calibration and work, the same property (conductivity and dielectric constant) material as target electrode should be chosen for capacitive hydrostatic leveling sensors. Otherwise, there is an error of sensors after calibration, and the main factor is conductivity. (authors)

  5. Variable-capacitance tachometer eliminates troublesome magnetic fields

    Science.gov (United States)

    1966-01-01

    Dual variable-capacitance tachometer measures angular speed and sense of rotation without magnetic components. Thus it eliminates magnetic flux interference with associated instrumentation in an electromechanical system.

  6. Quantum capacitance of graphene in contact with metal

    International Nuclear Information System (INIS)

    We report a versatile computation method to quantitatively determine the quantum capacitance of graphene when it is in contact with metal. Our results bridge the longstanding gap between the theoretically predicted and experimentally measured quantum capacitance of graphene. Contrary to popular assumptions, the presence of charged impurities or structural distortions of graphene are not the only sources of the asymmetric capacitance with respect to the polarity of the bias potential and the higher-than-expected capacitance at the Dirac point. They also originate from the field-induced electronic interactions between graphene and metal. We also provide an improved model representation of a metal–graphene junction

  7. Neighboring and Connectivity-Aware Routing in VANETs

    Directory of Open Access Journals (Sweden)

    Huma Ghafoor

    2014-01-01

    Full Text Available A novel position-based routing protocol anchor-based connectivity-aware routing (ACAR for vehicular ad hoc networks (VANETs is proposed in this paper to ensure connectivity of routes with more successfully delivered packets. Both buses and cars are considered as vehicular nodes running in both clockwise and anticlockwise directions in a city scenario. Both directions are taken into account for faster communication. ACAR is a hybrid protocol, using both the greedy forwarding approach and the store-carry-and-forward approach to minimize the packet drop rate on the basis of certain assumptions. Our solution to situations that occur when the network is sparse and when any (source or intermediate node has left its initial position makes this protocol different from those existing in the literature. We consider only vehicle-to-vehicle (V2V communication in which both the source and destination nodes are moving vehicles. Also, no road-side units are considered. Finally, we compare our protocol with A-STAR (a plausible connectivity-aware routing protocol for city environments, and simulation results in NS-2 show improvement in the number of packets delivered to the destination using fewer hops. Also, we show that ACAR has more successfully-delivered long-distance packets with reasonable packet delay than A-STAR.

  8. Neighboring and Connectivity-Aware Routing in VANETs

    Science.gov (United States)

    Koo, Insoo

    2014-01-01

    A novel position-based routing protocol anchor-based connectivity-aware routing (ACAR) for vehicular ad hoc networks (VANETs) is proposed in this paper to ensure connectivity of routes with more successfully delivered packets. Both buses and cars are considered as vehicular nodes running in both clockwise and anticlockwise directions in a city scenario. Both directions are taken into account for faster communication. ACAR is a hybrid protocol, using both the greedy forwarding approach and the store-carry-and-forward approach to minimize the packet drop rate on the basis of certain assumptions. Our solution to situations that occur when the network is sparse and when any (source or intermediate) node has left its initial position makes this protocol different from those existing in the literature. We consider only vehicle-to-vehicle (V2V) communication in which both the source and destination nodes are moving vehicles. Also, no road-side units are considered. Finally, we compare our protocol with A-STAR (a plausible connectivity-aware routing protocol for city environments), and simulation results in NS-2 show improvement in the number of packets delivered to the destination using fewer hops. Also, we show that ACAR has more successfully-delivered long-distance packets with reasonable packet delay than A-STAR. PMID:24982996

  9. Abandoned vehicles

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The services in charge of managing the CERN site have recently noted an increase in the number of abandoned vehicles. This poses a risk from the point of view of safety and security and, on the eve of several important events in honour of CERN's fiftieth anniversary, is detrimental to the Organization's image. Owners of vehicles that have been left immobile for some time on the CERN site, including on the external car park by the flags, are therefore invited to contact the Reception and Access Control Service (service-parking-longterm@cern.ch) before 1st October 2004 and, where appropriate, move their vehicle to a designated long-term parking area. After this date, any vehicle whose owner has failed to respond to this request and which is without a number plate, has been stationary for several weeks or is out of service, may be impounded at the owner's risk and expense. Relations with the Host States Service Tel. 72848

  10. Algoritmos genéticos e computação paralela para problemas de roteirização de veículos com janelas de tempo e entregas fracionadas Genetic algorithms and parallel computing for a vehicle routing problem with time windows and split deliveries

    Directory of Open Access Journals (Sweden)

    Guilherme Guidolin de Campos

    2006-05-01

    Full Text Available O presente trabalho propõe a utilização de metaheurísticas e computação paralela para a resolução de um problema real de roteirização de veículos com frota heterogênea, janelas de tempo e entregas fracionadas, no qual a demanda dos clientes pode ser maior que a capacidade dos veículos. O problema consiste na determinação de um conjunto de rotas econômicas que devem atender à necessidade de cada cliente respeitando todas as restrições. A estratégia adotada para a resolução do problema consiste na utilização de uma adaptação da heurística construtiva proposta por Clarke e Wright (1964 como solução inicial. Posteriormente, implementa-se um algoritmo genético paralelo que é resolvido com o auxílio de um cluster de computadores, com o objetivo de explorar novos espaços de soluções. Os resultados obtidos demonstram que a heurística construtiva básica apresenta resultados satisfatórios para o problema, mas pode ser melhorada substancialmente com o uso de técnicas mais sofisticadas. A aplicação do algoritmo genético paralelo de múltiplas populações com solução inicial, que apresentou os melhores resultados, proporciona redução no custo total da operação da ordem de 10%, em relação à heurística construtiva, e 13%, quando comparada às soluções utilizadas originalmente pela empresa.The present work considers the use of metaheuristics and parallel computing to solve a real problem of vehicle routing involving a heterogeneous fleet, time windows and split deliveries, in which customer demand can exceed vehicle capacity. The problem consists of determining a set of economical routes that meet each customer's needs while still being subject to all the constraints. The strategy adopted to solve the problem consists of an adaptation of the constructive heuristics proposed by Clarke & Wright (1964 as the initial solution. More sophisticated algorithms are then applied to achieve improvements, such as

  11. Alternative iron making routes

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, P.; Sharma, T. [Indian School of Mines, Dhanbad (India)

    2002-07-01

    The versatile route of iron production 'blast furnace' technique is being replaced by widely accepted Corex technology, Midrex process using Fastmelt ironmaking, eco-friendly Romelt process, more innovative Ausmelt & Hismelt technology, TATA KORF Mini blast furnace improvement, 'quickest iron through Orbiting Plasma', Direct iron ore smelting process, Conred, AISI-Hyl, Inred processes, Direct iron ore reduction methods, their comparison and proposed modifications. 18 refs., 11 figs., 14 tabs.

  12. Nanostructured conducting polymer based reagentless capacitive immunosensor.

    Science.gov (United States)

    Bandodkar, Amay Jairaj; Dhand, Chetna; Arya, Sunil K; Pandey, M K; Malhotra, Bansi D

    2010-02-01

    Nanostructured polyaniline (PANI) film electrophoretically fabricated onto indium-tin-oxide (ITO) coated glass plate has been utilized for development of an immunosensor based on capacitance change of a parallel plate capacitor (PPC) by covalently immobilizing anti-human IgG (Anti-HIgG) using N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide chemistry. These fabricated PANI/ITO and Anti-HIgG/PANI/ITO plates have been characterized using scanning electron microscopy, cyclic voltammetry, differential pulse voltammetry and Fourier transform infra-red studies. The capacitance measurements indicate that dielectric medium of this biologically modified PPC (Anti-HIgG/PANI/ITO) is sensitive to HIgG in 5 - 5 x 10(5) ng mL(-1) range and has lower detection limit of 1.87 ng mL(-1). The observed results reveal that this Anti-HIgG modified PPC can be used as a robust, easy-to-use, reagentless, sensitive and selective immunosensor for estimation of human IgG.

  13. THERMAL DRIFT CHARACTERISTICS OF CAPACITIVE PRESSURE SENSORS

    Directory of Open Access Journals (Sweden)

    ABDELAZIZ BEDDIAF

    2016-03-01

    Full Text Available The capacitive pressure sensors based on silicon are characterized by their very high sensitivities and their low power consumption. Nevertheless, their thermal behavior remains more or less unpredictable because they can indicate very high thermal coefficients. The study of the thermal behavior of these sensors is essential to define the parameters that cause the output characteristics drift. In this study, we modeled the thermal behavior of this sensors, using Finite Element Analysis (FEA made in COMSOL. The model solved by COMSOL environment takes into account the entire sensor and thermal effects due to the temperature considering the materials’ properties, the geometric shape and also the heat transfer mechanisms. By COMSOL we determine how the temperature affects the sensor during the manufacturing process. For that end, we calculated the thermal drift of capacitance at rest, the thermal coefficients and we compared them with experimental results to validate our model. Further, we studied the thermal drift of sensor characteristics both at rest and under constant and uniform pressure. Further, our study put emphasis on the geometric influence parameters on these characteristics to optimize the sensor performance. Finally, this study allows us to predict the sensor behavior against temperature and to minimize this effect by optimizing the geometrical parameters.

  14. Proportional microvolume capacitive liquid level sensor array.

    Science.gov (United States)

    Seliskar, D; Waterbury, R; Kearney, R

    2005-01-01

    A sensor array has been developed for use with laboratory automation to permit closed-loop control of liquid levels in a multiwell microplate geometry. We extended a simple electrical model for non-contact capacitance-based fluid sensors to describe a fluid-level dependency. The new model shows that a charge-transfer based capacitance transducer, employing a liquid-specific calibration, can be used to obtain an output signal that varies linearly with the liquid level. The calibration also compensates for liquid-to-liquid conductivity and permittivity differences. A prototype 3×3 sensor array was built and tested using NaCl and ethanol solutions to simulate the range of conductivity and permittivity typical in biological and chemical research. Calibrated output signals were linear with liquid volume for all tested solutions (R2>0.92). Measurement error averaged 1.3 % (2.0 μl) with a standard deviation of 6.0% (9.0 μl). These results demonstrate the feasibility of developing a microvolume sensor array in essentially any M×N microplate geometry. PMID:17281955

  15. A capacitive electrode with fast recovery feature

    International Nuclear Information System (INIS)

    Capacitive electrodes (CEs) allow for acquiring biopotentials without galvanic contact, avoiding skin preparation and the use of electrolytic gel. The signal quality provided by present CEs is similar to that of standard wet electrodes, but they are more sensitive to electrostatic charge interference and motion artifacts, mainly when biopotentials are picked up through clothing and coupling capacitances are reduced to tens of picofarads. When artifacts are large enough to saturate the preamplifier, several seconds (up to tens) are needed to recover a proper baseline level, and during this period biopotential signals are irremediably lost. To reduce this problem, a CE that includes a fast-recovery (FR) circuit is proposed. It works directly on the coupling capacitor, recovering the amplifier from saturation while preserving ultra-high input impedance, as a CE requires. A prototype was built and tested acquiring ECG signals. Several experimental data are presented, which show that the proposed circuit significantly reduces record segment losses due to amplifier saturation when working in real environments. (paper)

  16. Electronic route information panels (DRIPs).

    NARCIS (Netherlands)

    2008-01-01

    Also in the Netherlands, the term Dynamic Route Information Panel (DRIP) is used for an electronic route information panel. A DRIP usually indicates whether there are queues on the various routes to a particular destination and how long they are. On certain locations DRIPS also give the estimated tr

  17. Optimisation of MSW collection routes for minimum fuel consumption using 3D GIS modelling.

    Science.gov (United States)

    Tavares, G; Zsigraiova, Z; Semiao, V; Carvalho, M G

    2009-03-01

    Collection of municipal solid waste (MSW) may account for more than 70% of the total waste management budget, most of which is for fuel costs. It is therefore crucial to optimise the routing network used for waste collection and transportation. This paper proposes the use of geographical information systems (GIS) 3D route modelling software for waste collection and transportation, which adds one more degree of freedom to the system and allows driving routes to be optimised for minimum fuel consumption. The model takes into account the effects of road inclination and vehicle weight. It is applied to two different cases: routing waste collection vehicles in the city of Praia, the capital of Cape Verde, and routing the transport of waste from different municipalities of Santiago Island to an incineration plant. For the Praia city region, the 3D model that minimised fuel consumption yielded cost savings of 8% as compared with an approach that simply calculated the shortest 3D route. Remarkably, this was true despite the fact that the GIS-recommended fuel reduction route was actually 1.8% longer than the shortest possible travel distance. For the Santiago Island case, the difference was even more significant: a 12% fuel reduction for a similar total travel distance. These figures indicate the importance of considering both the relief of the terrain and fuel consumption in selecting a suitable cost function to optimise vehicle routing. PMID:18835768

  18. AN INTERSECTION BASED TRAFFIC AWARE ROUTING WITH LOW OVERHEAD IN VANET

    Directory of Open Access Journals (Sweden)

    Lakshmi Ramachandran

    2013-01-01

    Full Text Available Vehicular Ad-hoc network is an emerging class of wireless network that provide efficient communication between vehicles and between vehicles and road side units. VANETs are gaining attention from both industrial and academic point of view due to its applications ranging from safety applications to infotainment applications. The main component for success of VANET applications is its routing. Design of an efficient routing protocol is important for smart Intelligent Transport System (ITS. In this paper, we consider how traffic lights affect the design of routing protocol in urban vehicular communication. In urban environment the roads are partitioned to several segments due to the traffic lights. The design of a routing protocol in such an environment is difficult. This paper proposes a new intersection based routing protocol which takes traffic lights in to consideration and with low overhead.

  19. Routing Protocol in Urban Environment for V2V communication Vanet

    Directory of Open Access Journals (Sweden)

    My Driss Laanaoui

    2013-01-01

    Full Text Available The vehicle-to-vehicle communication is a very actual and challenging topic. Vehicles equipped with devices capable of short-range wireless connectivity can form a particular mobile ad-hoc network, VANET-Vehicular Ad-hoc Network. The existence of such networks opens the way for a wide range of applications. Two of the most important classes of such applications are those related to route planning and traffic safety. Route planning aims to provide drivers with real-time traffic information, which, in the absence of a VANET, would require an expensive infrastructure. In this work we evaluate our VANET routing protocol that is especially designed for city environments. This protocol is based on the localization of the node, the cost assigned to the section and score for each vehicle.

  20. Effective local dynamic routing strategy for air route networks

    Institute of Scientific and Technical Information of China (English)

    Wu Wenjun; Zhao Lingxi

    2015-01-01

    With the rapid development of air transportation, network service ability has attracted a lot of attention in academe. Aiming to improve the throughput of the air route network (ARN), we propose an effective local dynamic routing strategy in this paper. Several factors, such as the rout-ing distance, the geographical distance and the real-time local traffic, are taken into consideration. When the ARN is in the normal free-flow state, the proposed strategy can recover the shortest path routing (SPR) strategy. When the ARN undergoes congestion, the proposed strategy changes the paths of flights based on the real-time local traffic information. The throughput of the Chinese air route network (CARN) is evaluated. Results confirm that the proposed strategy can significantly improve the throughput of CARN. Meanwhile, the increase in the average flying distance and time is tiny. Results also indicate the importance of the distance related factors in a routing strategy designed for the ARN.