A Multi-Criteria Route Selection Method for Vehicles Using Genetic Algorithms Based on Driver’s Preference

Wireless Personal Communications - Finding the best path between a given source and a destination in a road network is an important problem. It has its applications in various map services and...     

Modulated Triple‐Material Nano‐Heterostructures: Where Gold Influenced the Chemical Activity of Silver in Nanocrystals

For efficient charge separations, multimaterial hetero‐nanostructures are being extensively studied as photocatalysts. While materials with one heterojunction are widely established, the chemistry of formation of multijunction heterostructures is not explored. This needs a more sophisticated approach and modulations. To achieve these, a generic multistep seed mediated growth following controlled ion diffusion and ion exchange is reported which successfully leads to triple‐material hetero‐nanostructures with bimetallic‐binary alloy‐binary/ternary semiconductors arrangements. Ag₂S nanocrystals are used as primary seeds for obtaining AuAg‐AuAgS bimetallic‐binary alloyed metal–semiconductor heterostructures via partial reduction of Ag(I) using Au(III) ions. These are again explored as secondary seeds for obtaining a series of triple‐materials heterostructures, AuAg‐AuAgS‐CdS (or ZnS or AgInS₂), with introduction of different divalent and trivalent ions. Chemistry of each step of the gold ion–induced changes in the rate of diffusion and/or ion exchanges are investigated and the formation mechanism for these nearly monodisperse triple material heterostructures are proposed. Reactions without gold are also performed, and the change in the reaction chemistry and growth mechanism in presence of Au is also discussed.     

IIR system identification using cat swarm optimization

Conventional derivative based learning rule poses stability problem when used in adaptive identification of infinite impulse response (IIR) systems. In addition the performance of these methods substantially deteriorates when reduced order adaptive models are used for such identification. In this paper the IIR system identification task is formulated as an optimization problem and a recently introduced cat swarm optimization (CSO) is used to develop a new population based learning rule for the model. Both actual and reduced order identification of few benchmarked IIR plants is carried out through simulation study. The results demonstrate superior identification performance of the new method compared to that achieved by genetic algorithm (GA) and particle swarm optimization (PSO) based identification.     

Supplier behavior modeling and winner determination using parallel MDP

Behavioral uncertainty of a supplier is a major challenge to a buyer operating in e-procurement setting. Modeling suppliers’ behavior from past transactions, estimation of possible future performance and integrating this knowledge with the winner determination process can bring a new dimension to procurement process automation. We propose a states-space model to capture the uncertainty involved in long-term supplier behavior. The states represent the performance level of a supplier. This behavioral aspect is then integrated with the winner determination process of a multi-attribute reverse auction for efficient supplier selection using parallel MDP. We also propose an implementation framework to collect the feedback on supplier, generate an aggregate performance score and integrate it with the winner determination process. The performance aggregation and winner determination with help of Markov decision process effectively uses the past performance information. In addition, it updates performance information in regular invervals and allevates the problem of maintaining a long history. We compare the MDP-based selection with that of performance score-based selection through a simulation experiment. It is observed that our scheme gives better buyer utility, selects best suppliers and fetches better quality product. The benefits realized through these attributes to the buyer increases the efficiency of the MDP-based selection process.     

A query model to synthesize answer intervals from indexed videounits

While a query result in a traditional database is a subset of the database, in a video database, it is a set of subintervals extracted from the raw video sequence. It is very hard, if not impossible, to predetermine all the queries that will be issued in the future, and all the subintervals that will become necessary to answer them. As a result, conventional query frameworks are not applicable to video databases. We propose a new video query model that computes query results by dynamically synthesizing needed subintervals from fragmentary indexed intervals in the database. We introduce new interval operations required for that computation. We also propose methods to compute relative relevance of synthesized intervals to a given query. A query result is a list of synthesized intervals sorted in the order of their degree of relevance     

Structural features of evaporated nickel films on oxide supports

Nickel was vacuum-deposited at high temperature (1000–1600°C) on alumina and at room temperature on Hiflosupercel (diatomaceous earth). Light microscopy/Scanning electron microscopy/Energy Dispersive x-ray analysis investigations on the coated materials indicate structural features such as uniform dispersal and firm binding of nickel crystallites on the oxide surfaces and suggests that the feasibility of vacuum technology may offer certain advantages over the conventional processes for making dispersed metal catalysts.     

Low-temperature magnetic and electromagnetic studies of Y-Ba-Cu-O: Agx Ceramic superconductor

Magnetization and magnetic relaxation measurements have been studied at 4.2 K on YBa₂Cu₃O_7–:Ag _x (x=0 to 1.2) superconducting samples prepared by a coprecipritation technique. Remanent magnetization and hysteresis loops were found to be increased on Ag addition. Transport current density (J _c) was enhanced with the addition of Ag concentration. Flux creep rate was also increased with increase in Ag addition resulting in stronger pinning potential. Microwave-induced d.c. voltage measurements show a reduction of weak links with increase in Ag concentration. The enhancement of transportT _c is attributed to the stronger Josephson current paths due to the reduction of the total number of weak links after Ag addition.     

Job scheduling in mesh multicomputers

A new approach for dynamic job scheduling in mesh-connected multiprocessor systems, which supports a multiuser environment, is proposed in this paper. Our approach combines a submesh reservation policy with a priority-based scheduling policy to obtain high performance in terms of high throughput, high utilization, and low turn-around times for jobs. This high performance is achieved at the expense of scheduling jobs in a strictly fair, FCFS fashion; in fact, the algorithm is parameterized to allow trade-offs between performance and (short-term) POPS fairness. The proposed scheduler can be used with any submesh allocation policy. A fast and efficient implementation of the proposed scheduler has also been presented. The performance of the proposed scheme has been compared with the FCFS policy, the only existing scheduling strategy for meshes, to demonstrate the effectiveness of the proposed approach. Simulation results indicate that our scheduling strategy outperforms the FCFS policy significantly. Specifically, our strategy significantly reduces the average waiting delay of jobs over the FCFS policy. The fast implementation of the proposed scheduler results in low allocation and deallocation time overhead, as well as low space overhead     

Effect of synthesis temperature on density and microstructure of MgB2 superconductor at ambient pressure

The experimental thermodynamic of MgB₂ synthesis process and phase compositions have been investigated by diffraction thermal analysis (DTA) technology and X-ray diffraction. The fabrication of MgB₂ bulks and superconducting properties at the temperatures range from 600 to 800°C were reported. And microstructure of MgB₂ bulks were observed by scanning electron microscope (SEM). A method was developed to determine the porosity of MgB₂ and the highest density can be obtained in MgB₂ prepared at 650°C at ambient pressure. It is found that the vapor pressure of Mg increases remarkably at high temperature, leading to the high porosity in MgB₂ samples. MgB₂ bulk with good superconducting property and fine microstructure was synthesized at 750°C.