Automating the identification and analysis of protein {beta}-barrels

ßBarrels are widespread and well-studied featuresof a great many protein structures. In this paper an unsuper-visedmethod for the detection of P-barrels is developed based ontechniques from graph theory. The hydrogen bonded connectivityof ß-sheets is derived using standard pattern recognitiontechniques and expressed as a graph. Barrels correspond to topologicalrings in these connectivity graphs and can thus be identifiedusing ring perception algorithms. Following from this, the characteristictopological structure of a barrel can be expressed using a novelform of reduced nomenclature that counts sequence separationsbetween successive members of the ring set These techniquesare tested by applying them to the detection of barrels in anon-redundant subset of the Brookhaven database. Results indicatethat topological rings do seem to correspond uniquely to ß-barrelsand that the technique, as implemented, finds the majority ofbarrels present in the dataset.     

转移法色交换

将图Ｇ的着色由一种变为中一种，通常用Ｋｅｍｐｅ法以交换。但是，对于某些情况，用此法无效。针对这个问题，本文提出了一种转移法色交换，它适用于平面图着色，方法直观，清晰且有效。     

Energy minimization and design for testability

The problem of fault detection in general combinational circuits is NP-complete. The only previous result on identifying easily testable circuits is due to Fujiwara who gave a polynomial time algorithm for detecting any single stuck fault inK-bounded circuits. Such circuits may only contain logic blocks with no more thanK input lines and the blocks are so connected that there is no reconvergent fanout among them. We introduce a new class of combinational circuits called the (k, K)-circuits and present a polynomial time algorithm to detect any single or multiple stuck fault in such circuits. We represent the circuit as an undirected graphG with a vertex for each gate and an edge between a pair of vertices whenever the corresponding gates have a connection. For a (k, K)-circuit,G is a subgraph of ak-tree, which, by definition, cannot have a clique of size greater thank+1. Basically, this is a restriction on gate interconnections rather than on the function of gates comprising the circuit. The (k, K)-circuits are a generalization of Fujiwara'sK-bounded circuits. Using the bidirectional neural network model of the circuit and the energy function minimization formulation of the fault detection problem, we present a test generation algorithm for single and multiple faults in (k, K)-circuits. This polynomial time aggorithm minimizes the energy function by recursively eliminating the variables.     

Integrating integer programming and probabilistic deduction graphs for probabilistic reasoning

Optimal solutions of several variants of the probabilistic reasoning problem were found by a new technique that integrates integer programming and probabilistic deduction graphs (PDG). PDGs are extended from deduction graphs of the and-type via normal deduction graphs. The foregoing variants to be solved can involve multiple hypotheses and multiple evidences where the former is given and the latter is unknown and being found or vice versa. The relationship among these hypotheses and evidences with possible intermediaries is represented by a causal graph. The proposed method can handle a large causal graph of any type and find an optimal solution by invoking a linear integer programming package. In addition, formulating the reasoning problem to fit integer programming takes a polynomial time. H.-L. Li was visiting the Department of Computer Sciences, University of North Texas in 1988–1989. He is with the Institute of Information Management, National Chiao Tung University, Hsinchu, Taiwan, R.O.C.     

一种椭圆弧长的作图求解法及其误差分析

本文给出了一种椭圆弧长的作图求解方法,即由作图求得椭圆弧长的近似值。通过对100个椭圆弧长的求解结果表明,由此方法求得的椭圆弧长的误差甚小,从而在相当高的精度范围内,提供了一种工程中适用并且简单易行的求解椭圆弧长的方法。     

Linearly many faults in Cayley graphs generated by transposition trees

We prove that when linearly many vertices are deleted in a Cayley graph generated by a transposition tree, the resulting graph has a large connected component containing almost all remaining vertices.     

工程管理信息系统的设计与实现技巧探讨

通过实例,对管理信息系统的功能模块、关系数据库进行了分析、设计和实现,并总结了其实现过程中的有关技巧。     

包装装潢中的图形创意

图形创意在商品包装装潢设计中起着重要的作用,图形的传统和现代的构成形式使产品更具风格,独创性是其生命力所在,而联想和想象又是创造力的主要源泉,这种联想和想象力通过自然形、抽象形和寓意图形来体现.所以包装设计需要突破,通过图形创意的不断完善,促销产品,使其为市场接受,被顾客赞誉.     

综合线损分析系统研究

描述了综合线损分析系统应该具有的主要功能和分析内容，介绍了系统实现中应该注意的几个问题、系统内容和实现方法。