Context sensitive trust based geographic opportunistic routing in mobile ad hoc networks

Sādhanā - Position based opportunistic routing (POR) is a stateless, robust, and reliable geographic routing protocol in Mobile AdHoc NETwork (MANET). The opportunistic routing embraces...     

A multisource energy harvesting utilizing highly efficient ferroelectric PMN-PT single crystal

This paper demonstrates a multi-source energy harvester that is able to utilize simultaneously both piezoelectric and pyroelectric effects in lead magnesium niobate-lead titanate (PMN-PT) single crystal. The paper presents a study of PMN-PT single crystal with a (67:33) composition grown in our laboratory via a vertical gradient freeze method without any flux. The performance of the piezoelectric and pyroelectric energy harvester using unimorph device structure was evaluated via modeling and experiment. The theoretical study was implemented based on a distributed parameter electromechanical model and the modelling procedure was approximated using finite element analysis to predict the electromechanical behavior of the harvester. The maximum power density at a resonance frequency of 50 Hz and optimum resistance of 2 MΩ was 16.7 nW/(g² cm³) under a 1 g acceleration of vibration. The measured values of electrical output parameters were in good agreement with theoretical and modelling results using MATLAB and COMSOL Multiphysics, respectively. By using the pyroelectric effect along with the piezoelectric effect, the output voltage of the energy harvester was found to be enhanced at the optimum resistance and specific frequency values. It was noticed that the output voltage was increased monotonically with temperature-difference (ΔT) and reaches up to 180 % of its original value under temperature difference of 1.7 °C at a frequency value of 49 Hz.     

Generalized linear complementarity in a problem ofn-person games

In this paper, we introduce a generalization of the polymatrix game (a nonzero sum noncooperativen-person game) considered by Howson and relate the problem of computing an equilibrium set of strategies for such a game to the generalized linear complementarity problem of Cottle and Dantzig. For an even more general version of the game we prove the existence of an-equilibrium set of strategies. We also present a result on the stability of the equilibria based on degree theory.     

On burst rescheduling in OBS networks with partial wavelength conversion capability

The core nodes in an optical burst switching (OBS) network are normally equipped with wavelength converters (WCs) to reduce the burst loss probability. Since WCs are expensive and still immature technologically, it is desirable to reduce the number of WCs in the network and to have partial wavelength conversion capability at the core nodes. Nevertheless, a majority of algorithms in the literature are proposed under the full wavelength conversion assumption. As a result, they do not consider the burst loss caused by insufficient WCs, i.e., bursts dropped due to the unavailability of free WCs to convert them to unused wavelengths. In this paper, we demonstrate how to use burst rescheduling to decrease the burst loss due to insufficient WCs and hence cut down on the overall burst loss probability in OBS networks. Two burst rescheduling algorithms are proposed. Their effectiveness in reducing the overall burst loss probability is verified through simulation experiments.     

基于SIMD指令的柔性物体并行碰撞检测

复杂场景中柔性物体间的碰撞检测依然难以满足交互设计的要求.为了提高处理速度,文中给出了一种充分利用现代CPU的并行处理能力的碰撞检测算法.算法基于两方面的并行处理:即基于SIMD指令的指令级并行处理和基于多线程的任务级并行处理.算法给出了一种针对SIMD指令特别优化的k-DOP模型--SIMD-DOP,从理论上分析了该包围盒的高效性,并与常规的16-DOP和24-DOP进行了运行效率对比.通过使用SIMD-DOP同时在多核间进行负载均衡,算法获得了优化的并行加速.文中算法已经在一台16核工作站上针对一组复杂测试场景进行了验证.     

Real-time path planning in dynamic virtual environments using multiagent navigation graphs

We present a novel approach for efficient path planning and navigation of multiple virtual agents in complex dynamic scenes. We introduce a new data structure, Multi-agent Navigation Graph (MaNG), which is constructed using first- and second-order Voronoi diagrams. The MaNG is used to perform route planning and proximity computations for each agent in real time. Moreover, we use the path information and proximity relationships for local dynamics computation of each agent by extending a social force model [Helbing05]. We compute the MaNG using graphics hardware and present culling techniques to accelerate the computation. We also address undersampling issues and present techniques to improve the accuracy of our algorithm. Our algorithm is used for real-time multi-agent planning in pursuit-evasion, terrain exploration and crowd simulation scenarios consisting of hundreds of moving agents, each with a distinct goal.     

Transjurisdictional Water Pollution Management in China: The Legal and Institutional Framework

The current study shows that the recent diesel price hike had an insignificant impact on irrigation costs incurred by diesel well owners in eastern India. Further, analysis of the farming enterprises of diesel well owners and water buyers from both diesel and electric wells confronted with a differential cost of irrigation water showed that farmers would be able to cope with a very high rise in irrigation costs through irrigation efficiency improvements and allocating more area to crops that give higher returns per unit of land and water. By doing this, they are able to maintain the farm returns.     

Drivers of change in agricultural water productivity and its improvement at basin scale in developing economies

We approach the issue of water productivity in agriculture by identifying five sets of drivers of change. We find that irrigation efficiencies at the field level can result in real water savings under certain conditions, but that small farmers in most of South Asia and Africa have little incentive to adopt the appropriate measures. Although water productivity improvement and water savings at the regional level are possible through a shift to economically efficient crops, such changes may be constrained by concerns with respect to domestic and regional food security, rural employment, and farming system resilience.     

Concept-based near-duplicate video clip detection for novelty re-ranking of web video search results

State-of-the-art near-duplicate video clip (NDVC) detection for novelty re-ranking uses non-semantic low-level features (color/texture) to detect and eliminate “content-based NDVC” and increases content level novelty in the top results. However, humans may perceive a video as near duplicate from a semantic perspective as well. In this paper, we propose concept-based near-duplicate video clip (CBNDVC) detection technique for novelty re-ranking. We identify “semantic NDVC”, making use of the semantic features (events/concepts) and re-rank the top results to increase the content as well as semantic novelty. Videos are represented as a multivariate time series of confidence values of relevant concepts and thereafter discovery of CBNDVC clusters is achieved by conceptual clustering. Obtained results show higher precision and recall from the user’s perspective.