SCSI接口的新进展──SCSI─3

ＡＮＳＩ正在加速进行对下一代接口标准──ＳＣＳＩ─３的标准化工作。本文较全面地介绍了ＳＣＳＩ─３接口的最新动向及ＷＩＤＥＳＣＳＩ的规定。在介绍ＳＣＳＩ─３的发展和基本功能的基础上，简述了ＳＣＳＩ─３的文件结构，然后对并行接口的动向作了较为详细的阐述，最后简述了串行接口的发展。     

MCS—51单片机与微机通用并行接口（GPIB）通讯的实现

ＧＰＩＢ接口即ＩＥＥＥ－４８８接口标准，是一种通用８位并行接口，广泛应用于工业控制和自动测试系统，本文介绍了基于ＭＣＳ－５１单片机的ＧＰＩＢ接口的实现方法，并详细介绍了软件与硬件的设计。     

MCS－51单片机与微机通用并行接口（GPIB）通讯的实现

ＧＰＩＢ接口即ＩＥＥＥ－４８８接口标准，是一种通用８位并行接口，广泛应用于工业控制和自动测试系统。本文介绍了基于ＭＣＳ－５１单片机的ＧＰＩＢ接口的实现方法，并详细介绍了软件与硬件的设计。     

单片机的显示接口电路设计

介绍了利用单片机的串、并行接口和专用显示接口 IC 设计显示接口电路的方法,并提供了4种动态和静态显示的硬件接口电路。     

高精度A／D转换器远程数据采集接口

高精度Ａ／Ｄ转换器ＩＣＬ７１３５能自动将Ａ／Ｄ结果按５位ＢＣＤ码形式输出，因此较适合于微机并行接口的数据传送。ＩＣＬ７１３５与单片机的接口多数是并行接口形式。本文介绍一种更为简便、经济的接口形式。１接口方案在一些抗干扰要求较高的情况下，需要对Ａ／Ｄ输...     

多路数据通讯控制机

本文描述了我路数据通讯控制机的硬件和部件软件设计，详细介绍了控制机的性能和可编程通讯接口芯片８２５１和并行接口芯片８１５５的特点和工作方式，以及与ＭＣＳ－８０３１单机的硬件联接和中断处理。此外，对软件设置滤特率的方法和控制机初始化处理也作了较为详细的阐述。     

学MAC──苹果机的SCSI接口及使用

学ＭＡＣ──苹果机的ＳＣＳＩ接口及使用文：创天一、ＳＣＳＩ接口：ＳＣＳＩ接口是所有苹果电脑都具备的接口，是连接使用“小型计算机系统介面”ＳＣＳＩ的装置，通过ＳＣＳＩ接口，计算机就可与ＳＣＳＩ设备间进行高速的信息传递，下图所示为ＳＣＳＩ接口的外形及图标...     

SCSI－2总线结构

ＳＣＳＩ－２已经成为计算机通用的输入输出接口，已经涉足高档计算机的系统接口。在论述ＳＣＳＩ－２特点的基础上，简述了ＳＣＳＩ－２的接口规范，并介绍了二种ＳＣＳＩ一２专用集成电路。     

测试梅捷最新6VCA主板！

梅捷最近连续推出了两款最新 的ＰＲＯ１３３Ａ的主板，一款是ＳＬＯＴ１接口的ＳＹ－６ＶＣＡ，另一款则是５３７０接口的ＳＹ－７ＶＣＡ，今天我们要测试的就是ＳＬＯＴ１接口的ＳＹ－６ＶＣＡ。两张板其实除了接口之外并没有什么大的区别。就目前的销售情况来看，这两张板在很短的时间内取得了相当好的成绩，而且他们也继承了ＳＯＹＯ自从６ＢＡ＋ Ⅲ和 Ⅳ以来的良好口碑。（图 １） 这张６ＶＣＡ提供了１个ＡＧＰ，１个ＡＭＲ，５个ＰＣＩ和１个ＩＳＡ槽。北桥芯片是６９４Ｘ，南桥芯片是６８６Ａ，支持ＡＣ９７，有可选的 ４个 ＵＳＢ…     

SCSI接口的一个新动态

ＳＣＳＩ接口的一个新动态磁盘驱动器性能的最关键部分是到主机系统的接口。最新技术使接口控制器允许更高的数据率、缓冲器带宽以及到主机的传输宽度。最流行的一种接口就是ＳＣＳＩ，因为它有迅速提高性能的潜力。其数据传输率为ＳＭＢ／Ｓ（最初的ＳＣＳＩ），１０ＭＢ...     

Artificial neural network model for predicting protein subcellular location.

The function of a protein is closely correlated to its subcellular location. Is it possible to utilize a bioinformatics method to predict the protein subcellular location? To explore this problem, proteins are classified into 12 groups (Protein Eng. 12 (1999) 107-118) according to their subcellular location: (1) chloroplast, (2) cytoplasm, (3) cytoskeleton, (4) endoplasmic reticulum, (5) extracellular, (6) Golgi apparatus, (7) lysosome, (8) mitochondria, (9) nucleus, (10) peroxisome, (11) plasma membrane and (12) vacuole. In this paper, the neural network method was proposed to predict the subcellular location of a protein according to its amino acid composition. Results obtained through self-consistency, cross-validation and independent dataset tests are quite high. Accordingly, the present method can serve as a complement tool for the existing prediction methods in this area.     

随机优化问题基于假设检验的遗传算法

为了有效解决具有不确定性和多极小性的随机优化问题 ,提出了一类基于假设检验的遗传算法 .该方法通过多次评价来进行解性能的合理估计 ,利用遗传操作来进行解空间的有效搜索 ,采用假设检验来增加种群的多样性和算法的探索能力 ,从而避免遗传算法的早熟收敛 .基于典型的随机函数优化和组合优化问题 ,仿真研究了假设检验、性能估计次数、噪声幅度对算法性能的影响 ,验证了所提方法的有效性和鲁棒性     

Analysis of the interaction between the dendritic conductance density and activated area in modulating alpha-motoneuron EPSP: statistical computer model

Five reconstructed alpha-motoneurons (MNs) are simulated under physiological and morphological realistic parameters. We compare the resulting excitatory postsynaptic potential (EPSP) of models, containing voltage-dependent channels on the dendrites, with the EPSP of a passive MN and an active soma and axon model. In our simulations, we apply three different distribution functions of the voltage-dependent channels on the dendrites: a step function (ST) with uniform spatial dispersion; an exponential decay (ED) function, with proximal to the soma high-density location; and an exponential rise (ER) with distally located conductance density. In all cases, the synaptic inputs are located as a gaussian function on the dendrites. Our simulations lead to eight key observations. (1) The presence of the voltage-dependent channels conductance (g(Active)) in the dendrites is vital for obtaining EPSP peak boosting. (2) The mean EPSP peaks of the ST, ER, and ED distributions are similar when the ranges of G (total conductance) are equal. (3) EPSP peak increases monotonically when the magnitude of g(Na_step) (maximal g(Na) at a particular run) is increased. (4) EPSP kinetics parameters were differentially affected; time integral was decreased monotonically with increased g(Na_step), but the rate of rise (the decay time was not analyzed) does not show clear relations. (5) The total G can be elevated by increasing the number of active dendrites; however, only a small active area of the dendritic tree is sufficient to get the maximal boosting. (6) The sometimes large variations in the parameters values for identical G depend on the g(Na_step) and active dendritic area. (7) High g(Na_step) in a few dendrites is more efficient in amplifying the EPSP peak than low g(Na_step) in many dendrites. (8) The EPSP peak is approximately linear with respect to the MNs' R(N) (input resistance).     

神经网络用于三元分子混合物密度与粘度的预测

以二元系实验为基础，利用反向转播算法训练神经网络，构造混合物组成，温度等与物性关系的模型，用于对４个三元混合物体系（１）邻二甲苯－间二甲苯－对二甲苯；（２）四氯化碳－环己烷－２－丙醇；（３）甲醇－丙酮－水；（４）水－甲醇－乙二醇的密度和５个三元混合物体系（１）信甲苯－间二甲苯－对二甲苯；（２）四氯化碳－环己烷－２－丙醇；（３）氯仿－２－丙醇－２－丁醇；（４）甲醇－丙酮－水；（５）乙醇－甲醇－水的粘     

Combinatorial optimization in system configuration design

The significance of systems configurations has been increased in many applied domains (e.g., software, hardware, manufacturing systems, communication systems, supply chain systems, solving strategies, modular planning, material engineering and combinatorial chemistry). Generally, the following kinds of systems under configuration (reconfiguration) can be examined: (a) initial data/infomation (or row materials); (b) processing systems (machines, computers, algorithms); (c) resultant decisions (e.g., products, plans); (d) applied support systems (e.g., network systems, services); (e) requirements; and (f) standards. In the paper several system configuration problems are investigated: (i) searching for (selection of) a set (structure) of system components, (ii) searching for a set of compatible system components, (iii) allocation of system components, (iv) reconfiguration of a system as redesign of the system structure, (v) multi-stage design and redesign of system configuration, (vi) design or redesign of the system configuration for multi-product systems, and (vii) design of system hierarchy. Combinatorial optimization models (including multicriteria statements) are under examination: multiple choice problem, allocation problem, graph coloring problems, morphological clique problem (with compatibility of system components), multipartite clique and their modifications, spanning trees problems.     

Studies of tricyclic piperazine/piperidine furnished molecules as novel integrin αvβ3/αIIbβ3 dual antagonists using 3D-QSAR and molecular docking

The development of injectable integrin α(v)β(3)/α(IIb)β(3) dual antagonists attracts much attention of research for treating of acute ischemic diseases in recent years. In this work, based on a dataset composed of 102 tricyclic piperazine/piperidine furnished dual α(v)β(3) and α(IIb)β(3) antagonists, a variety of in silico modeling approaches including the comparative molecular field analysis (CoMFA), comparative similarity indices analysis (CoMSIA), and molecular docking were applied to reveal the requisite 3D structural features impacting the biological activities. Our statistical results show that the ligand-based 3D-QSAR models for both the α(v)β(3) and α(IIb)β(3) studies exhibited satisfactory internal and external predictability, i.e., for the CoMFA models, results of Q(2)=0.48, R(ncv)(2)=0.87, R(pred)(2)=0.71 for α(v)β(3) and Q(2)=0.50, R(ncv)(2)=0.85, R(pred)(2)=0.72 for α(IIb)β(3) analysis were obtained, and for the CoMSIA ones, the outcomes of Q(2)=0.55, R(ncv)(2)=0.90, R(pred)(2)=0.72 for α(v)β(3) and Q(2)=0.52, R(ncv)(2)=0.88, R(pred)(2)=0.74 for α(IIb)β(3) were achieved respectively. In addition, through a comparison between 3D-QSAR contour maps and docking results, it is revealed that that the most crucial interactions occurring between the tricyclic piperazine/piperidine derivatives and α(v)β(3)/α(IIb)β(3) receptor ligand binding pocket are H-bonding, and the key amino acids impacting the interactions are Arg214, Asn215, Ser123, and Lys253 for α(v)β(3), but Arg214, Asn215, Ser123 and Tyr190 for α(IIb)β(3) receptors, respectively. Halogen-containing groups at position 15 and 16, benzene sulfonamide substituent at position 23, and the replacement of piperazine with 4-aminopiperidine of ring B may increase the α(v)β(3)/α(IIb)β(3) antagonistic activity. The potencies for antagonists to inhibit isolated α(v)β(3) and α(IIb)β(3) are linear correlated, indicating that similar interaction mechanisms may exist for the series of molecules. To our best knowledge this is the first report on 3D-QSAR modeling of these dual α(v)β(3)/α(IIb)β(3) antagonists. The results obtained should provide information for better understanding of the mechanism of antagonism and thus be helpful in design of novel potent dual α(v)β(3)/α(IIb)β(3) antagonists.     

Graphic analysis of resources by numerical evaluation techniques (Garnet)

An interactive computer program for graphical analysis has been developed by the U.S. Geological Survey. The program embodies five goals, (1) economical use of computer resources, (2) simplicity for user applications, (3) interactive on-line use, (4) minimal core requirements, and (5) portability. It is designed to aid (1) the rapid analysis of point-located data, (2) structural mapping, and (3) estimation of area resources.     

Book Reviews

Book review in this Article Margaret Dale & Paul Iles (1992) Assessing Management Skills: A Guide to Competencies and Evaluation Techniques Dean Tjosvold (1991) Team Organization: An Enduring Competitive Advantage Brian Thomas (1992) Total Quality Training: The Quality Culture and Quality Training Michael J. Comer, Patrick M. Ardis, & David Price (1992) Bad Lies in Business, McGraw Hill Rosemary Dinnage (1992) The Ruffian on the Stair Peter Frost and Ralph Stablein (Eds) (1992) Doing Exemplary Research Janet Sayers (1992) Mothering Psychoanalysis, Penguin Books Vivian Walsh, Robin Roy, Margaret Bruce & Stephen Potter (1992) Winning by Design: Technology, Product Design & International Competitiveness David Megginson & Mike Pedler (1992) Self-Development: A Facilitators Guide Linda L. Putnam and Michael E. Roloff (1992) Communication and Negotiation Peter M. Senge (1990) The Fifth Discipline: The Art and Practice of The Learning Organization Keith Bradley (1992) Phone Wars, The Story of Mercury Communications Gordon J. Pearson (1992) The Competitive Organization Sonja A. Sackmann (1991) Cultural Knowledge in Organisations: Exploring the Collective Mind     

Skew prime polynomial matrices

A pair of polynomial matrices,P(s)andQ(s), is defined to be "externally skew prime" if and only if a solution,M(s), N(s), to the polynomial matrix equationP(s)M(s)+N(s)Q(s)=Iexists. It is shown thatP(s)andQ(s)are externally skew prime if and only ifQ(s)P(s)= bar{P}(s)R(s)withQ(s)andbar{P}(s)relatively left prime andP(s)andR(s)relatively right prime. This observation implies a new constructive procedure for determiningM(s)andN(s)whereP(s)andQ(s)are found to be externally skew prime andP(s)is nonsingular. A new procedure for obtaining solutions to the more general polynomial matrix equation,P(s)M(s)+N(s)Q(s)= V(s), based on the notion of skew-prime polynomial matrices is also presented. A characterization of all solutions whenV(s)= Iis also given, under appropriate assumptions, and then employed to determine a unique solution to this polynomial matrix equation.