Recommendations in a heterogeneous service environment

This paper presents novel algorithms which are able to generate recommendations within a heterogeneous service environment. In this work explicitly set preferences as well as implicitly logged viewing behavior are employed to generate recommendations for Digital Video Broadcast (DVB) content. This paper also discusses the similarity between the DVB genres and YouTube categories. In addition it presents results to show the comparison between well known collaborative filtering methods. The outcome of this comparison study is used to identify the most suitable filtering method to use in the proposed environment. Finally the paper presents a novel Personal Program Guide (PPG), which is used as a tool to visualize the generated recommendations within a heterogeneous service environment. This PPG is also capable of showing the linear DVB content and the non-linear YouTube videos in a single view.     

Hydraulic lift systems with piston type pump

More difficult conditions of oil production process in recent years impose the necessity of finding out new technical solutions that will provide reliable and efficient lifting of reservoir fluid to the surface.Technical solution presented in this paper, hydraulically driven piston pump, is one of the attempts in the field of artificial exploitation methods, to find a solution that will work effectively in different well types (vertical, horizontal and directional) and at depths that are greater than those achieved until today.The task of this paper is to show the innovation in the pump construction. Innovations are made in the coiled tubing construction, one pipeline instead two or three; double acting type pump with reservoir fluid repression, towards the surface, through a channel drilled in the piston.The new technical solution, laboratory prototype, has been tested and the results are presented in tables and on graphs in this paper. The aim is that after testing the laboratory prototype comes to the data that will be used for the design of industrial product.     

π-ELECTRON CONTENTS OF RINGS IN THE DOUBLE-HEXAGONAL-CHAIN HOMOLOGOUS SERIES (PYRENE,ANTHANTHRENE AND OTHER ACENOACENES)

Abstract

Recently three methods for calculating the π-electron content of rings of benzenoid hydrocarbons were put forward: one based on the consideration of Kekuléstructural formulas, and the other two based on an analogous treatment of the Clar aromatic sextet formulas. These three methods are applied to the homologous series consisting of two condensed acene chains (whose first members are pyrene, anthanthrene, peri-naphthacenonaphthacene, …), leading to basically identical results. In contrast to acenes (in which the partition of π-electrons into rings is uniform), in the double-hexagonal-chain species the partition of π-electrons is highly non-uniform. The electron content monotonically decreases, in opposite directions, along the two acene chains, being maximal in the least annelated rings. Some other generally valid regularities in the π-electron properties of the double–hexagonal–chain benzenoids are also pointed out.     

Congestion control for multimedia applications in the wireless internet

This paper provides a parallel review of two important issues for the next‐generation multimedia networking. Firstly, the emerging multimedia applications require a fresh approach to congestion control in the Internet. Currently, congestion control is performed by TCP; it is optimised for data traffic flows, which are inherently elastic. Audio and video traffic do not find the sudden rate fluctuations imposed by the TCP multiplicative‐decrease control algorithm optimal. The second important issue is the mobility support for multimedia applications. Wireless networks are characterized by a substantial packet loss due to the imperfection of the radio medium. This increased packet loss disturbs the foundation of TCP's loss‐based congestion control. This paper contributes to the ongoing discussion about the Internet congestion control by providing a parallel analysis of these two issues. The paper describes the main challenges, design guidelines, and existing proposals for the Internet congestion control, optimised for the multimedia traffic in the wireless network environment. Copyright © 2004 John Wiley & Sons, Ltd.     

Complexity of coordinated beamforming and scheduling for OFDMA based heterogeneous networks

Wireless Networks - Coordination is foreseen to be an important component of future mobile radio networks. It is especially relevant in heterogeneous networks, where high power base stations...     

Heating Cable Application in Solving Paraffin Deposition Problem in Tubing

Please click here to view a statement of retraction concerning this article.     

Adaptation of the program for positioning direction of handling robot to working space for installation during systematic plane errors

The paper presents a method to compensate for the systematic plane error of a handling robot while executing installation operations of the flat installation type of plane objects or box covers with small overlap height. The method may also be used in the welding and cutting of plane contours. The systematic error is found on the basis of position measurements at three points, and the necessary correction of the program is calculated. Thus, by the start of the production process, the robot positions the objects exactly or executes the contour operations with high precision.     

IGBT模块化平台——用于先进的功率应用

1 引言 IGBT模块化平台能够提高很多功率设备或系统的开发效率，特别是其中一些非常新颖的系统。这种平台能够为产品的应用带来很多益处，包括：软开关大功率逆变器、带有减少直流电容组并且增加可靠性的AC／AC变换器、多电平模块化的可升级的大功率逆变器以及由一个大功率低频变换器和一个小功率高频多功能负载调节器而构成的高性能、低成本的功率变换系统。