22909785
A dynamic holding strategy in public transit systems with real-time information
Abstract
Holding strategies are among the most commonly used operation control strategies in transit systems. In this paper, a dynamic holding strategy is developed, which consists of two major steps: (1) judging whether an early bus should be held, and (2) optimizing the holding times of the held bus. A model based on support vector machine (SVM), which contains four input variables (time-of-day, segment, the latest speed on the next segment, and the bus speed on the current segment) for forecasting the early bus departure times from the next stop is also developed. Then, in order to determine the optimal holding times, a model aiming to minimize the user costs is constructed and a genetic algorithm is used to optimize the holding times. Finally, the dynamic holding strategy proposed in this study is illustrated with the microscopic simulation model Paramics and some conclusions are drawn.

207714575
An improved ant colony optimization for vehicle routing problem
The vehicle routing problem (VRP), a well-known combinatorial optimization problem, holds a central place in logistics management. This paper proposes an improved ant colony optimization (IACO), which possesses a new strategy to update the increased pheromone, called ant-weight strategy, and a mutation operation, to solve VRP. The computational results for fourteen benchmark problems are reported and compared to those of other metaheuristic approaches.
17737533
Semantic Matching of Web Services Based on Choreographies
Web services facilitate the efficient execution of B2B e-commerce by integrating business processes over the Internet, which needs dynamic and flexible binding of services. However, current Web service standards do not support it. A formal approach for semantic matching of service specifications based on choreographies, i.e., the behavior of Web services, is developed in this paper. It can accurately and automatically discover required services for integrating business processes. Firstly an extended deterministic finite state automaton (EDFA) is proposed by labeling state transitions using binary-tuples (input, output) rather than letters. The automata describe Web services in a more accurate way: the nodes represent states maintained by services; the state transitions represent communication activities of services. The automata depict the temporal sequences of communication activities that describe the behaviors of services. Further, the intersection of two EDFAs is defined. Finally, an algorithm for testing the emptiness of the languages accepted by EDFAs is presented and used to evaluate the compatibility of Web services
35252339
Hybrid Control of Hopf Bifurcation for an Internet Congestion Model
In this paper, the problem of Hopf bifurcation control for an Internet congestion model with time delays is considered by using a new hybrid control strategy, in which state feedback and parameter perturbation are used. It is well known that for the system without control, as the positive gain parameter of the system passes a critical point, Hopf bifurcation occurs. To control the Hopf bifurcation, a hybrid control strategy is proposed and the onset of an inherent bifurcation is delayed (advanced) when such bifurcation is undesired (desired). Furthermore, the dynamic behaviors of the controlled system can also be changed by choosing appropriate control parameters. Numerical simulation results confirm that the new control strategy is efficient in controlling Hopf bifurcation.
27633879
A more efficient branch and bound algorithm for feature selection
Abstract An algorithm is presented to be able to select the globally optimal subset of d features from a larger D -feature set. This is a fundamental problem in statistical pattern recognition and combinatorial optimization. Exhaustive enumeration is computationally unfeasible in most applications. This algorithm dynamically searches for the globally optimal solution on a minimum solution tree which is a subtree of the solution tree used in the traditional branch and bound algorithm. The new algorithm is compared theoretically with the branch and bound algorithm. The analysis and the experimental results show that it is more efficient than the traditional algorithm.
17926099
Research and Design of One Key Agreement Scheme in Bluetooth
Since there is eavesdropping and MITM attack during establishing encryption key between two Bluetooth devices, a secure key agreement scheme is designed based on elliptic curves cryptography and interlock protocol. This scheme can defend two kinds of attacks mentioned above. It provides bidirectional authentication for two devices and key integrity verification by exchanging the keyspsila Hash-value. Then security of the scheme is theoretically analyzed and efficiency of it is compared with that of other schemes in relative papers. The results demonstrate the scheme proposed in this paper is secure and efficient.
18656180
Application of PGA on Optimization of Distribution of Shopping Centers
In this study, the distribution of shopping centers is optimized in terms of realizing the shortest car-based shopping trips in an urban area. Modal split is performed between road and public traffic networks is calculated, and then the interaction between land-use and transportation in the context of choice of shopping destinations is modeled to build the optimal function. Parallel genetic algorithm (PGA) is applied to solve the optimal problem on distribution of the area of shopping centers. Several problems in application of PGA are discussed. A case study is undertaken in order to examine the effectiveness of this method.