An Improved Scheme for Interest Mining Based on a Reconfiguration of the Peer-to-Peer Overlay

Tan et al. proposed a scheme to improve the quality of a file search in unstructured Peer-to-Peer systems by focusing on the similarity of interest of the participating peers. Although it certainly improves the cost/performance ratio of a simple flooding-based scheme used in conventional systems, the Tan's method has a serious drawback such that a query cannot reach a target peer if a requesting peer is not connected with the target peer through a path consisting of peers to have similar interest to the given query. In order to overcome such drawback of the Tan's method, we propose a scheme to reconfigure the underlying network in such a way that a requesting peer has a neighbor interested in the given query, before transmitting a query to its neighbors. The performance of the proposed scheme is evaluated by simulation. The result of simulation indicates that it certainly overcomes the drawback of the Tan's method

Minimum-cost line broadcast in paths

AbstractUnder the line communication protocol, calls can be placed between pairs of non-adjacent sites over a path of lines connecting them; only one call can utilize a line at any time. This paper addresses questions regarding the cumulative cost, i.e., sum of lengths of calls, of broadcasting under the line protocol in path networks. Let Pn be the path with n vertices, and Cn be the cost of an optimal, line broadcast scheme from a terminal vertex in path Pn. We show that a minimum-cost line broadcast scheme from any source vertex in Pn has cost no more than Cn and no less than Cn − n + 2 for any n ⩾ 2 and any time t > [log2n]. We derive a closed-form expression for the minimum cost of a minimum-time line broadcast from a terminal vertex in certain paths and relate this to costs from nearby sources

An Efficient Web Page Recommendation Based on Preference Footprint to Browsed Pages

This paper proposes a new scheme for web page recommendation which reflects the preference of each user to the recommended pages in an efficient and effective manner. The basic idea of the scheme is to combine the notion of preference footprint to browsed pages with the collaborative filtering. More concretely, we introduce the notion of "tags" similar to conventional SBS (Social Bookmark Service), and attach all tags associated with a user to a page when it is browsed by him. We implemented a prototype of the proposed scheme, and conducted preliminary experiments to evaluate the performance of the scheme. The result of experiments indicates that it takes less than 0.5 sec to reorder a list of 500 URLs received from a search engine according to the preference of users

MODELING AND SIMULATION OF IN SITU BIOREMEDIATION FOR TCE-CONTAMINATED GROUNDWATER THROUGH METHANE INJECTION IN KIMITSU CITY JAPAN

Joint Research on Environmental Science and Technology for the Eart

Control and performance of a zero-current-switched three-phase inverter equipped with resonant circuits on the AC-side

This paper presents a zero-current-switched voltage-fed inverter equipped with resonant circuits on the AC side. The current flowing through a switching device, i.e., an IGBT is a sum of the load current and the resonant current. If the amplitude of the resonant current is larger than that of the load current, the current in a switching device becomes zero at an instant in each resonant cycle. This allows the switching device to be turned on or off at the zero current. The zero-current-switching makes a significant contribution to reduction of switching losses and electromagnetic noises. In this paper, the principle of zero-current-switching operation, and a novel control scheme are described from a theoretical and practical point of view. Experimental results obtained from a laboratory system of 5 kVA verify the practicability. Moreover, the efficiency and losses of the proposed soft-switched inverter are compared with those of a hard-switched inverter </p

An approach to a broad range of power control in voltage-source series-resonant inverters for corona discharge treatment-pulse-density-modulation

This paper implements a wide range of power control with pulse-density-modulation (PDM) in a voltage source series-resonant inverter which realizes a corona discharge for the surface treatment of films. The use of the PDM inverter enables the employment of a three-phase diode bridge rectifier as an electric utility interface. The PDM inverter produces either a square-wave AC voltage state or a zero voltage state at its AC terminals to control the discharge power of a corona surface treater. Moreover, it can achieve zero-current-switching (ZCS) and zero-voltage-switching (ZVS) under all the operating conditions, thus leading to a significant reduction of switching losses and electromagnetic noise. A 80 kHz, 6 kW surface treatment system consisting of a voltage-source PDM inverter, a step-up transformer and a corona discharge treater shows the establishment of a stable corona discharge in an extremely wide range of power control from 0.5 to 100 %, and therefore succeeds in performing both strong and weak surface treatment processes for films </p