A 1 GHz CMOS analog front-end for a generalized PRML read channel

A 1 GHz CMOS analog front-end for general partial response maximum likelihood (GPRML) read channel in hard disk drive application has been implemented in 0.35 /spl mu/m CMOS. A continuous time analog filter fulfills the relaxed equalization for GPRML detection and can save up to 35% power consumption for the whole read channel. An analog DFE-based timing recovery loop is implemented to avoid the extremely long latency in the digital signal processing path (Viterbi decoder). The measured performances is 1.1 dB off simulations at 800 MHz and 1.6 dB off at 1GHz. The chip draws 240 mW from a 3.3 V supply at 800MHz clock and 380 mW from a 3.6 V supply at 1 GHz clock.     

An Optimized Content-Aware Authentication Scheme for Streaming JPEG-2000 Images Over Lossy Networks

This paper proposes an optimized content-aware authentication scheme for JPEG-2000 streams over lossy networks, where a received packet is consumed only when it is both decodable and authenticated. In a JPEG-2000 codestream, some packets are more important than others in terms of coding dependency and image quality. This naturally motivates allocating more redundant authentication information for the more important packets in order to maximize their probability of authentication and thereby minimize the distortion at the receiver. Towards this goal, with the awareness of its corresponding image content, we formulate an optimization framework to compute an authentication graph to maximize the expected media quality at the receiver, given specific authentication overhead and knowledge of network loss rate. System analysis and experimental results demonstrate that the proposed scheme achieves our design goal in that the rate-distortion (R-D) curve of the authenticated image is very close to the R-D curve when no authentication is required     

Mining process models with non-free-choice constructs

Process mining aims at extracting information from event logs to capture the business process as it is being executed. Process mining is particularly useful in situations where events are recorded but there is no system enforcing people to work in a particular way. Consider for example a hospital where the diagnosis and treatment activities are recorded in the hospital information system, but where health-care professionals determine the “careflow.” Many process mining approaches have been proposed in recent years. However, in spite of many researchers’ persistent efforts, there are still several challenging problems to be solved. In this paper, we focus on mining non-free-choice constructs, i.e., situations where there is a mixture of choice and synchronization. Although most real-life processes exhibit non-free-choice behavior, existing algorithms are unable to adequately deal with such constructs. Using a Petri-net-based representation, we will show that there are two kinds of causal dependencies between tasks, i.e., explicit and implicit ones. We propose an algorithm that is able to deal with both kinds of dependencies. The algorithm has been implemented in the ProM framework and experimental results shows that the algorithm indeed significantly improves existing process mining techniques.     

钻井液固相化学清洁剂ZSC-201的合成及性能

介绍了钻井液用固相化学清洁剂ZSC－201的室内合成及性能评价，结果表明，固相化学清洁剂ZSC－201具有较强的抑制性，可有效抑制粘土水化分散，保证钻井液清洁，在钻井液体系中与阴、阳离子型钻井液处理剂配伍性好，同时具有较好的抑制增效作用，在有效的加量内对钻井液滤矢量和流变性等影响小，固相化学清洁剂ZSC－201已在中原油田近30口井中应用，具有良好的推广应用前景。     

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以天然气为能源，用燃气机代替电动机驱动压缩机并充分利用发动机废热、工业余热以及低品位环境热量的采暖、空调装置——燃气压缩式热泵近年来发展迅速。美国燃气设备的总装机容量已达到1．2GW，日本燃气机热泵占全部燃气制冷设备的29％，总装机容量大约1GW，燃气机热泵在英国、法国、德国、瑞士等都得到了较快的发展与应用。中研究了以天然气为驱动能源的压缩式热泵的特点及能量利用率，分析并测试了该系统的运行特性及交工况特性，进行了各种工况及转速下的实验研究。结果表明，该系统具有较好的部分负荷特性、一次能源利用率及交工况特性，为一种绿色高效的供热空调系统。     

硫酸铈和磷酸处理对铌酸表面酸度及催化活性的影响

用硫酸铈和磷酸对固体铌酸进行了表面处理。表面酸度和TG DTA测定结果表明 ,与未处理的固体铌酸相比 ,处理后表面强酸量提高 3～ 5倍 ,耐受温度由 30 0℃提高到 5 0 0～ 6 0 0℃。用于催化酯化合成二甘醇二苯甲酸酯增塑剂 ,处理后固体铌酸的催化活性和重复使用寿命有明显提高。     

矿石中金的快速测定

研究了活性炭纤维滤布富集分离的条件和解脱方法,并利用微波溶样、液珠萃取比色法测定矿石中的金。该方法的测定范围为(0.5~xx)×10-6,相对标准偏差RSD为3.2%,可用于矿石中金的野外快速测定。     

20T/H工业锅炉主汽压回路参数寻优自适应PID控制

本文给出了一个自适应PID调节器应用于工业锅炉燃烧系统控制的实例,为克服自适应 控制中所遇到的实际问题,采用了监控级专家控制.实际运行表明,该系统优于常规PID调节器.     

Failure loads for notched graphite/epoxy laminates with a softening strip

The strengths of two graphite/epoxy notched laminate systems with a softening strip were investigated. The softening strip was created by replacing the 0°-graphite/epoxy plies by a glass/epoxy composite. Experimental results indicated that the use of softening strips could significantly increase the laminate strength. Analysis was performed with finite elements developed using the classical laminated plate theory and was shown to be adequate. A simple point-stress failure criterion was used to predict the strength of notched laminates with softening strips and the result was found to be satisfactory.     

面向对象的程序设计语言CLUSTER86的设计与实现

本文介绍了笔者设计并实现的一种新型的面向对象的程序设计语言,着重讨论了在设计过程中采用的新的概念,并和其它类似语言作了比较.