Earticle

In software engineering, it is important issue that architects estimate the performance of software in the early phase of development process. Many approaches translate architecture based on UML into analytical models. However, in agent based system development, these approaches ignore or simplify the crucial details of the underlying the performance of an agent platform. Additionally, architects have only limited kinds of solution to improve performance of system architecture. In this paper, we propose analytical approach for performance improvement of multi-agent based system. This approach avoids the need for a prototype implementation since architects can determine overall form of the performance equation from the architectural design description and can enhance the system architecture to derive optimal architecture from analytical model. We verify the effectiveness of our approach through U-Commerce scenario.

Mobile and wireless network technologies enables us to communicate each other at any time, any place in the ubiquitous personal communications services(PCS). Among the technologies, location management of mobile users is one of the most important problems for tracking the location of mobile users. The location management basically is performed by using two registers, HLR(Home Location Register) and VLR(Visitor Location Register). Location of the mobile user is registered to the two databases for call tracking. And those registration operations cause many network traffic. In this paper, we propose a new simple location management by registering representative VLR of group of several VLRs regionally and broadcasting for searching a mobile user, so called rVLR-B. We manage the representative VLR of several VLRs and register mobile users’ location. When set up the call path between mobile users, the VLR of the caller queries callee’s rVLR for searching the location of callee instead of requesting to VLR of callee. And then rVLR broadcast the callee’s location to all VLR of the region concurrently. Location registration is only performed when a mobile user visits a new rVLR network area from current area. Using the rVLR-B, we can reduce the cost of maintaining location of mobile users.

Pervasive computing refers to making many computing devices available throughout the physical environment, while making them effectively invisible to the user. To further increase the applicability of ubiquitous computing, minimizing energy consumption and hardware cost are mandatory in real world applications. In this paper we present our platform prototype for ubiquitous computing, which has been implemented based on commercial Bluetooth off-theshelf components. It allows every object to be augmented with processing and communication capabilities in order to make them "smart". We validate our proposal by evaluating the tradeoff between power consumption and performance for our experimental prototype. Our prototype has been used in a museum application to support ubiquitous computing between devices without requiring a priori knowledge of each other.

The nature of the concepts regarding images in many domains are imprecise, and the interpretation of finding similar images is also ambiguous and subjective on the level of human perception. To solve these problems, in this paper, images’ semantic categories and the tolerance degree between them are defined systematically, and the approach of modeling tolerance relations between the semantic classes is proposed. Furthermore, for removing the induced false tolerance in the produce of using semantic tolerance relation model, the method of un-tolerating is introduced in image representation. We apply the proposed approach to the representations of images regarding the nature vs. man-made domain, human vs. nonhuman domain, and temporal domain, and compare the categorization results of them with the results not using semantic tolerance relation model. The results show the effectiveness of proposed method.

The paper addresses firmware implementation of multiple-output combinational and sequential Boolean functions based on cascades of Look-Up Tables (LUTs). A LUT cascade is described as a means of compact representation of a large class of Boolean functions, which reduces their evaluation to multiple indirect memory accesses. A LUT-oriented decomposition technique is illustrated on several examples. A specialized micro-engine is proposed for sequential processing of LUT cascades by means of multi-way branching. The presented method provides high performance micro-programmed control for embedded applications.

Nearest Neighbor (NN) search has been widely used in spatial databases and multimedia databases. Incremental NN (INN) search algorithm is regarded as the optimal NN search because of the minimum number of node accesses and it can be used no matter whether the number of objects to be retrieved is fixed or not in advance. This paper presents an analytical model for estimating performance of the INN search algorithm. For the first time, our model takes m (the number of neighbor objects reported finally), n (the cardinality of database) and d (the dimensionality) as parameters, focusing on the number of node accesses (not only the number of accessed leaf nodes) and the length of the priority queue. Using our model, dimensionality curse is mathematically revealed for an arbitrary number of NN objects retrieved. In our model, (1) for the first time, the two key factors of dm (the distance from the m-th NN object to the query point) and σ h (the side length of each node) are estimated using their upper bounds and their lower bounds, which is helpful to effectiveness of our model, especially in high-dimensional spaces; (2) for the first time, the possible difference of fanouts among the leaf nodes, the root node and the others is taken into account. The theoretical analysis is verified by experiments.

In this paper, we propose an algorithm, which allocates the bandwidth in an effective manner for sensitive applications. The main idea of this work is to allocate more amount of bandwidth for particular client, who has received more votes in the network. The proposed model reduces the wastage of bandwidth and increases the throughput.

The integration of embedded real-time control systems with the physical world via sensors and actuators (pervasive computing systems) is creating a nascent infrastructure for a technical, economic and social revolution. Service robots have to execute tasks that have different criticality, flexible timing constraints and variable execution time, because they perform their activities in dynamic and unpredictable environments, they share resources and have to cooperate to fulfill the objectives. The environmental conditions have influence in the variability of the system load. For instance, the computational requirements of recognition tasks are variable and dependent on the number of objects perceived in scenes. To tackle the computational variability of pervasive robots a real-time architecture is proposed in this paper.

We observe that the e-business systems development frameworks tradeoff performance at the expense of flexibility. In this paper, we present a performance comparison of JavaBeans application framework with a well-known framework, Struts. JavaBeans is a flexible and extensible CBD application framework. However the flexibility and extensibility are conflicting software qualities against the performance. Our experiment results show the significance of JavaBeans application framework over contemporary CBD application frameworks and how much its performance is affected by changing schemes of the framework for achieving flexibility and extensibility.

Expert systems for healthcare are widely studied where accuracy of diagnosis and efficiency of the system for various healthcare services are examined. Also, recent researches include decision support services, expert medical services and autonomous management, which are based on multi-agent systems. The cooperation of agents is crucial in analyzing, and managing the data of patient in order to detect abnormal patterns so that it can provide an advance treatment. This research shows the implementation of healthcare expert system (HES) based on group cooperation model. Communications through the components of the group cooperation model are designed based on multi-agent approach. The proposed agent managers effectively coordinate the processing of client requests. Replica managers provide quality of service for clients by replicating objects. An adaptive scheme using round robin and fuzzy least load algorithms is managed by load balancing service. And in this paper, we presented the implementation by using CORBA for distributed objects and Jade Framework for agents..

In this paper, we propose security level features and security level requirements to make a guide for each security level. Level requirements should be applied differently for technical and management parts, and the level requirements are designed by using step model for technology area and continuous-model for management areas.