Abstract This paper presents congruence results of a behavioural equivalence on a graph rewriting model of concurrent pro cesses with higher-order communication. A bipartite di rected acyclic graph represents a concurrent system that consists of a number of processes and messages in our model. The model presented here makes it possible to repre sent local names that their scopes are not... This paper presents congruence results of a behavioural equivalence on a graph rewriting model of concurrent pro cesses with higher-order communication. A bipartite di rected acyclic graph represents a concurrent system that consists of a number of processes and messages in our model. The model presented here makes it possible to repre sent local names that their scopes are not nested. We show that strong bisimulation equivalence relation is a congru ence relation w.r.t. operations that correspond to Ü-prefix, input prefix, new-name, replication, composition and appli cation respectively. Read More Read Less

Abstract A fi nal Clustering result of the k-means clustering algorithm greatly depends upon the correctness of the initial centroids. Generally the initial centroids for the k-means clustering are chosen randomly so that the selected initial centroids may converges to numerous local minima, not the global optimum. In this paper a new initialization approach to fi nd initial centroids for k-means... A fi nal Clustering result of the k-means clustering algorithm greatly depends upon the correctness of the initial centroids. Generally the initial centroids for the k-means clustering are chosen randomly so that the selected initial centroids may converges to numerous local minima, not the global optimum. In this paper a new initialization approach to fi nd initial centroids for k-means clustering is proposed. According to our experimental results, the Improved k-means Clustering Algorithm has the more accuracy with less computational time comparatively Original k-means clustering algorithm. Read More Read Less

Abstract In telerobotics applications, communication delays play a central role in overall system performance, and their minimization is a fundamental problem in this area. In this paper, we consider a master arm on the operator side, and a slave arms (Robot arm) operating in a wireless environment with sensors located on or around this slave arm. Sensor data needs to be... In telerobotics applications, communication delays play a central role in overall system performance, and their minimization is a fundamental problem in this area. In this paper, we consider a master arm on the operator side, and a slave arms (Robot arm) operating in a wireless environment with sensors located on or around this slave arm. Sensor data needs to be transmitted to the operator side to provide feedback, and operator commands must be transmitted to the slave arm to operate it. In a setup like this, minimization of transmission delays is of extreme importance for smooth interactive operation. In the fi rst part of the paper, we evaluate of two alternatives for wireless protocol development and analysis for our Mitsubishi robot RV-2AJ. The fi rst one is the Universal Software Radio Peripheral (USRP) [11] which has an FPGA for baseband processing and other possible low level protocol details. USRP has analog daughterboards for different frequency bands, including 900MHz, and 2.4GHz bands. USRP allows custom protocol development in the physical, and MAC layers, as well as the layers above these two. The second alternative system considered is a powerful microcontroller with an 802.11b controller card [12, 10]. In this system, lots of physical layer details are fi xed inside the 802.11b controller card, there is no operating system on the microcontroller, but one can generate custom 802.11 packets, and build custom protocols above the MAC layer for delay sensitive telerobotics applications. In the second part of the paper, we present the details of the proposed custom protocol and its implementation on the selected microcontroller board with an 802.11b controller. The proposed custom protocol is compared with standard data communication protocols, and it is demonstrated that the proposed protocol has smaller communication delays. Finally, in the presence of traffi c congestion, or/and low received signal strength, it has been also shown that the proposed protocol has signifi cant advantages compared to standard data communication protocols. Read More Read Less

Abstract Despite Aspect Oriented software development (AOSD) improve existing paradigms of development, by providing explicit mean to model crosscutting concern (aspect), the complexity of interactions among aspects and between aspects and base modules still a diffi cult problem that may reduce the value of aspect-oriented separation of cross-cutting concerns. The need of developing effi cient techniques that permits us identifi cation... Despite Aspect Oriented software development (AOSD) improve existing paradigms of development, by providing explicit mean to model crosscutting concern (aspect), the complexity of interactions among aspects and between aspects and base modules still a diffi cult problem that may reduce the value of aspect-oriented separation of cross-cutting concerns. The need of developing effi cient techniques that permits us identifi cation and analysis of interactions between aspects, rise and grow. In this paper we propose a technique that allows the user to analyse interaction between aspects, detect and resolve confl icts between them based on the search of Hamiltonians paths. The technique is based specifi cation it use the specifi cation of composition of aspects to analyse aspect and produce rules of composition and it is supposed generic in fact, that exploits the dependencies generated by the operators such as before, after, around and replace . Also, our contribution will be at aspect oriented requirement engineering (AORE) since, it is desirable to early possible identify aspect and analyse interactions too. The technique is illustrated through examples. Read More Read Less

Abstract In this paper, we propose a novel keyframe based video summarization system using QR-Decomposition. Specially, we attend to the challenges of defi ning some measures to detect the dynamicity of shot and video and extracting appropriate keyframes that assure the purity of video summary. We derive some effi cient measures to compute the dynamicity of video shots using QR-Decomposition and... In this paper, we propose a novel keyframe based video summarization system using QR-Decomposition. Specially, we attend to the challenges of defi ning some measures to detect the dynamicity of shot and video and extracting appropriate keyframes that assure the purity of video summary. We derive some effi cient measures to compute the dynamicity of video shots using QR-Decomposition and we utilize it in detecting the number of keyframes must be selected from each shot. Also, we derive a corollary that illustrates a new property of QR-Decomposition. We utilize this property in order to summarize video shots with low redundancy. The proposed algorithm is implemented and evaluated on TRECVID 2006 benchmark platform. Compared with results reported by others, our results are among the best. These results confi rm the high performance of the proposed algorithm. Read More Read Less