Multis: a new class of multiprocessor computers

Multis are a new class of computers based on multiple microprocessors. The small size, low cost, and high performance of microprocessors allow the design and construction of computer structures that offer significant advantages in manufacture, price-performance ratio, and reliability over traditional computer families. Currently, commercial multis consist of 4 to 28 modules, which include microprocessors, common memories, and input-output devices, all of which communicate through a single set of wires called a bus. Adding microprocessors together increases the performance of multis in direct proportion to their price and allows multis to offer a performance range that spans that of small minicomputers to mainframe computers. Multis are commercially available for applications ranging from real-time industrial control to transaction processing. Traditional batch, time-sharing, and transaction systems process a number of independent jobs that can be distributed among the microprocessors of a multi with a resulting increased throughput (number of jobs completed per unit of time). Many scientific applications (such as the solving of partial differential equations) and engineering applications (such as the checking of integrated circuit designs) are speeded up by this parallel computation; thus, multis produce results at supercomputer speed but at a fraction of the cost. Multis are likely to be the basis for the next, the fifth, generation of computers-a generation based on parallel processing.     

Technological trends in automobiles

Current technological trends in the automotive industry reflect many diverse disciplines. Electronics and microprocessors, new engine transmission concepts, composite and ceramic materials, and computer-aided design and manufacture will combine to make possible the creation of advanced automobiles offering outstanding quality, fuel economy, and performance. A projected "average" vehicle of the 1990's is described to illustrate the application of these new concepts.     

Mining simulation data by rule induction to determine critical source areas of stream water pollution by herbicides

Modelling in environmental sciences is becoming increasingly complex because ever-increasing numbers of processes are combined, thus making model-based decision aids both more relevant but more difficult to develop. Our approach focused on water quality and aimed to identify spatial tree patterns that represent surface flow and pollutant pathways from plot to plot involved in water pollution by herbicides. First, a simulation model predicted herbicide transfer rate, the proportion of applied herbicide that reaches water courses, based on the spatial and temporal distribution of weed-control activities. These predictions were used as a set of learning examples for symbolic learning techniques to induce rules based on qualitative and quantitative attributes and explain two classes of transfer rate. In this study we compared two automatic symbolic learning techniques applied to a set of simulations: (1) a relational-inductive method using the inductive logic programming (ILP) approach to induce spatial tree patterns; and (2) an attribute-value method to induce aggregated attributes of the trees. Twenty-eight and thirty-three rules were learnt by the ILP and attribute-value approaches which explained 81% and 88% of the examples, respectively. The ILP approach provided relevant indicators of plot-to-plot connectivity. The integrated attribute-value approach is simpler and quicker, but the ILP patterns are more useful for stakeholders.     

Analysis of Indica-Japonica Differentiation in Rice Parents and Derived Lines Using ILP Markers

Revealing the indica-japonica differentiation in parents of hybridization between indica and japonica rice and their derived lines can provide theoretical and practical bases for the breeding of practical inter-subspecific hybrid rice. Using subspeciesspecific molecular markers ILP （intron length polymorphism） and Cheng＇s index, the indica-japonica differentiation was analyzed with special materials including 18 indica-japonica hybrid parents and 39 derived lines, which accumulated different wide compatibility and restoring genes by convergent cross method in 21 years spanning four breeding phases. The indica-japonica differentiation was detected on all tested loci in 57 materials. Among the 18 parental lines, 4 were japonica type, 5 japonicaclinous type, 8 indicaclinous type and one indica type. The japonica proportion indexes in indica restorer lines Minghui 63 and 9308 were 12.50 and 33.33 %, respectively, while that in japonica restorer line C418 was only 31.25%. Among the 39 derived lines from indica-japonica hybridization, one was japonica type, 11 japonicaclinous type, 20 indicaclinous type and 7 indica type. The japonica proportion index in Minghui 502 was only 10.42%. The results of indica and japonica classification by ILP molecular markers and Cheng＇s index were relatively consistent. The correlation coefficient between the japonica proportion index and morphology index was 0.794＊＊, while that between the indica proportion index and morphology index was -0.7662＊＊. ILP markers could be used to accurately detect the proportion of indica/japonica content in the genome of a rice variety. The results of indica-japonica differentiation analysis could make reasonable explanation for that the hybrids obtained from indica-japonica type restorer lines had obvious heterosis. This conclusion would provide important guidance in efficient use of beneficial genes of inter-subspecific hybrid rice.     

利用ILP标记分析水稻籼粳杂交亲本和衍生系的籼粳分化

 【目的】揭示水稻籼粳杂交亲本和衍生系的籼粳分化度,为培育实用型籼粳亚种间杂交稻提供理论和实践依据。【方法】以通过不断聚合和累加不同广亲和基因与恢复基因的方法,历时21年,4个育种阶段,涉及18个籼粳杂交亲本和39个衍生系为研究材料,采用籼粳特异ILP分子标记（水稻内含子长度多态性分子标记）和程氏形态指数法进行籼粳分化度检测。【结果】57个供试材料基因组DNA在所检测位点上均存在籼粳分化。18个亲本共检测出4个粳稻、5个偏粳、8个偏籼和1个籼稻类型。在18个亲本中, 明恢63和9308的粳稻成分分别为12.50%和33.33%;粳型恢复系C418的粳稻成分仅有31.25%。39个籼粳杂交衍生系共检测出1个粳稻、11个偏粳、20个偏籼和7个籼稻类型。其中,粳型衍生系明恢502的粳稻成分仅占10.42%。ILP标记法与形态指数法判定籼粳分类结果的吻合度较好,粳稻成分指数、籼稻成分指数与程氏指数综合值的相关系数分别为r=0.794**和r=-0.7662**。【结论】ILP标记具有准确检测籼（粳）成分比例的功能;研究籼粳分化可以合理解释籼粳型恢复系配组的杂交稻表现明显杂种优势的原因,对有效利用籼粳亚种间优良基因具有重要作用。     

Toward the realization of a josephson computer

High-quality Josephson junctions, with both electrodes made from niobium and with an aluminum-oxide insulating barrier, were introduced in 1983. This niobium junction is very stable, reliable, controllable, and reproducible. Because of these excellent characteristics, these junctions can be applied to large-scale integrated (LSI) circuits, such as microprocessors having a few thousand gates and a few kilobits of memory. These circuits operate much faster and consume less power than any semiconductor circuit now available. Integrated Josephson circuits are now being tested in a closed-cycle refrigerator. The next step is to design a special-purpose, small-scale Josephson computer and to demonstrate its high performance.     

基于RISC处理器模型机的设计

本文简要介绍了RISC机的工作特性,讨论了RISC设计的一般原则,以及进一步应用VHDL在MAX＋plusⅡ的环境下设计RISC处理器模型机,以实现具有高效率、不断流、指令并行度ILP较高的处理器。     

Drosophila egg-laying site selection as a system to study simple decision-making processes

The ability to select a better option from multiple acceptable ones is important for animals to optimize their resources. The mechanisms that underlie such decision-making processes are not well understood. We found that selection of egg-laying site in Drosophila melanogaster is a suitable system to probe the neural circuit that governs simple decision-making processes. First, Drosophila females pursue active probing of the environment before depositing each egg, apparently to evaluate site quality for every egg. Second, Drosophila females can either accept or reject a sucrose-containing medium, depending on the context. Last, communication of the "acceptability" of the sucrose-containing medium as an egg-laying option to the reproductive system depends on the function of a group of insulin-like peptide 7 (ILP7)-producing neurons. These findings suggest that selection of egg-laying site involves a simple decision-making process and provide an entry point toward a systematic dissection of this process.     

Microprocessors: from desktops to supercomputers

Continuing improvements in integrated circuit technology and computer architecture have driven microprocessors to performance levels that rival those of supercomputers-at a fraction of the price. The use of sophisticated memory hierarchies enables microprocessor-based machines to have very large memories built from commodity dynamic random access memory while retaining the high bandwidth and low access time needed in a high-performance machine. Parallel processors composed of these high-performance microprocessors are becoming the supercomputing technology of choice for scientific and engineering applications. The challenges for these new supercomputers have been in developing multiprocessor architectures that are easy to program and that deliver high performance without extraordinary programming efforts by users. Recent progress in multiprocessor architecture has led to ways to meet these challenges.     

Precision optical testing

Increased performance requirements for modern optical systems have necessitated the development of more precise optical testing techniques. The need for accurate and rapid measurements is being met by the use of laser interferometers, microprocessors to gather test data, and computers to analyze the data and remove errors in the test equipment.     

单片机在线控制系统

本文阐述了单片机在线控制系统的一般模式及设计方法，并给出一种实用的单片机温度控制系统 。     

食品纳米包装材料的应用与安全性评价

纳米技术是当今科学界最具前景的科学技术之一,生物纳米复合材料的研究和开发将取得巨大突破。本文概述了纳米材料在食品包装领域的基本应用现状,并对相关的安全性评价问题进行了探讨。     

Computers in science and technology: early indications

Over the past 20 years computer technology has advanced rapidly, especially in the areas of logic and memory. Continued growth at a similar pace can be expected through and probably beyond the 1980's. The technology has already had such major effects on scientific research and engineering that it is of practical importance to try to predict its evolution and uses. It is likely that the trend toward smaller, faster, and cheaper circuits made possible by improved lithographic techniques will continue, resulting in a factor of 10 increase in speed of central processing units and an even greater increase in speed of single-chip microprocessors by the end of the decade. Similar progress is expected in the areas of memory, magnetic storage, printers, and displays. Overall, approximately 20 percent growth annually in the capability of computing systems can be projected. How this continually increasing computing power will affect scientific and engineering activity is more difficult to predict, but some patterns are emerging. Observations of technical personnel at the IBM research laboratory at Yorktown, New York, where the average user has access to a large amount of computing capability and to a worldwide computer network, indicate that workers in different areas have reacted to computer technology in different ways. Whereas engineers have used computing power, displays, and the ability to communicate or share information more or less equally, management has used communication most and scientists have put the greatest value on computing power and displays.     

基于循环经济的新农村建设CDM项目碳汇优化模型研究

以某县＂绿金嘉园——CDM新村镇园区＂项目为例,根据清洁发展机制（CDM）可再生能源项目的现状和特点,运用区间优化方法,在循环经济的模式下,将项目碳汇量作为优化目标,构建出一种基于不确定条件下的清洁发展机制碳汇优化模型,获取碳汇量最大的作物种植方案及牛群结构。案例分析表明,模型得出的优化作物种植方案及牛群结构布局合理,具有较好的总体性能,在满足经济效益和肥料、用电需求的前提下,可吸收和固定CO2[231287.8,273312.7]t,较项目可研方案提高了[12.94,33.46]%,为该CDM项目决策的制定提供了可靠依据。     

中国与CGIAR合作效果评价研究

中国自加入国际农业研究磋商组织(CGIAR)以来,与CGIAR建立了长期友好的合作伙伴关系,在合作过程中双方收获颇丰,但一直存在二者合作效果评估体系缺失的问题,无法量化地比较CGIAR与中国合作尤其是各所属中心与中国的合作差异。通过研究中国与CGIAR合作的情况与成效,结合CGIAR所属中心发布的报告等材料提取了与中国合作效果的量化指标,构建了中国与CGIAR合作效果测度的指标体系并确定了指标权重,再以13个参与评估的CGIAR中心为样本,基于权重,计算出各中心的科研绩效值,并通过横向(各中心之间)和纵向(不同年度)的对比,全面评估了CGIAR各中心的科研绩效表现和潜力的差异,为今后科学有效地分配中国政府对各中心的捐款提供了指导依据。     

基于循环经济的新农村建设CDM项目碳汇优化模型研究

以某县＂绿金嘉园——CDM新村镇园区＂项目为例,根据清洁发展机制（CDM）可再生能源项目的现状和特点,运用区间优化方法,在循环经济的模式下,将项目碳汇量作为优化目标,构建出一种基于不确定条件下的CDM碳汇优化模型,获取碳汇量最大的作物种植方案及牛群结构。案例分析表明,模型得出的优化作物种植方案及牛群结构布局合理,具有较好的总体性能,在满足经济效益和肥料、用电需求的前提下,可吸收和固定CO2[231 287.82,73 312.7]t,较项目可研方案提高了[12.943,3.46]%,为该CDM项目决策的制定提供了可靠依据。     

基于因子分析模型的基金业绩分析

近年来，我国证券投资基金规模不断壮大，成为我国资本市场上一支不可或缺的力量。证券投资基金是众多中小投资者的重要理财工具，因此，其业绩评估成为众多投资者以及管理者关心的重要话题。文章以成立于2008年之前的开放式股票型基金，共61只，为研究对象，分析了影响基金整体业绩的基金月平均收益率、标准差、夏普指数等若干主要因素。通过运用数据，采用因子分析的方法进而对基金业绩进行分析，综合得出了影响基金业绩的三个综合影响因子，并通过因子得分分析得出整体业绩排名前十的基金。为众多投资者提供了一个基金业绩评估的有效方法。     

Advances in process control

Advances in electronics and computers have enabled industries to attain better control of their processes with resulting increases in quality, productivity, profitability, and compliance with government regulations. With a hierarchy of computers, distributed data acquisition, and information processing and control, it is possible to achieve overall optimum performance of a plant. While further advances in microprocessors and large-scale integration will be useful to the process engineer, major improvements in process control await advances in sensor technology and software.     

Neuronal activity in the lateral intraparietal area and spatial attention

Although the parietal cortex has been implicated in the neural processes underlying visual attention, the nature of its contribution is not well understood. We tracked attention in the monkey and correlated the activity of neurons in the lateral intraparietal area (LIP) with the monkey's attentional performance. The ensemble activity in LIP across the entire visual field describes the spatial and temporal dynamics of a monkey's attention. Activity subtending a single location in the visual field describes the attentional priority at that area but does not predict that the monkey will actually attend to or make an eye movement to that location.     

油罐液位超声波测量技术应用前景

油罐液位测量是炼油厂，油库，加油站等部门的一项重要工作，超声波测量液位技术是近年来开发的项新技术。该技术用于油罐液位测量具有广泛的适用性，较高的可靠性，良好的性能／价格比，其缺点是精度低。提高超声波测量油罐液位技术的精度可通过采取改进测量方法，减少二次仪表误差等措施实现。