柔道服织物的设计与生产

本文对柔道服面料的风格、服用性能和物理机械性能进行了阐述,对其组织构结与设计、织造工艺等有关问题作了简要介绍。     

新型凹面齿圆柱蜗杆付的数值分析

本文通过数值分析,对作者提出的新型凹面齿圆柱蜗杆付及其它凹面齿圆柱蜗杆付的啮合质量指标(瞬时接触线,啮合区,一类界限曲线,二类界限曲线,诱导法曲率,瞬时接触线方向与合速度方向的夹角等)进行了研究,论征了该蜗杆付除具有工艺上的突出优点外,其啮合性能还优于其它凹面齿圆柱蜗杆付。     

用杯形砂轮加工凹凸齿圆柱蜗杆时最小砂轮半径的确定

本文分析了用杯形砂轮加工凹凸齿圆柱蜗杆时,砂轮与蜗杆不发生干涉的条件。根据齿轮啮合原理给出了不发生干涉时,确定最小砂轮半径的公式和方法,并根据计算结果给出了简易方法的近似公式,为实际加工提供了理论依据。本文也适用于凹面齿圆柱蜗杆的加工。     

钢管混凝土柱压弯剪试验与有限环层分析

文中概要记述21件钢管混凝土柱的试验资料,通过它与钢筋混凝土柱受力性能的比较,证实钢管混凝土柱的强度高、延性好。试验得知短柱的应变分布与剪跨比有关,钢管混凝土柱的受力为空间应力状态。在试验研究同时,应用电子计算机计算了钢管混凝土柱的应变与应力分布,采用的是有限环层法,实例计算结果与试验所得规律基本符合。     

Z-function convolution in EHV power network electromagnetic transient analysis

Time-convolution in the forms arising in transformation from the frequency-domain to the time-domain has been widely used in the earlier development of electromagnetic transient methods in power systems. Independent work has recently led to new methods based on the z-transform, and the present paper develops methods based on discrete convolution arising from transformation to the time-domain now from the z-plane. The recursive solution sequences to which this leads combines high accuracy with low computing time requirements. Checks and controls in the synthesis of transmission line forward impulse response and surge impedance functions in the z-plane ensure that these are always stable system functions, and that numerical solution procedures which include them have very high inherent stability. The formulations developed are applied to transmission line energization from an equivalent source model, and the electromagnetic transients in short-circuit fault operation. Close comparisons are made between representative solutions from standard time-convolution analysis and from the methods of the present paper.     

Simulations of biomolecules: Characterization of the early steps in the pH-induced conformational conversion of the hamster,bovine and human forms of the prion protein

As computer power increases, so too does the range of interesting biomolecular phenomena and properties that can be simulated. It is now possible to simulate complicated protein conformational changes at ambient or physiological temperatures. In this regard, we are attempting to map the conformational transitions of the normal, cellular prion protein (PrP(C)) to its infectious scrapie isoform (PrP(Sc)), which causes neurodegenerative diseases in many mammals. These two forms have identical sequences and are conformational isomers, with heightened formation of beta-sheet structure in the scrapie form. Conversion can be triggered by lowering the pH, but thus far it has been impossible to characterize the conformational change at high resolution using experimental methods. Therefore, to investigate the effect of acidic pH on PrP conformation, we have performed molecular-dynamics simulations of hamster, human and bovine forms of the prion protein in water at neutral and low pH. In all cases the core of the protein is well maintained at neutral pH. At low pH, however, the protein is more dynamic, and the sheet-like structure increases both by lengthening of the native beta-sheet and by addition of a portion of the N-terminus to widen the sheet by another 2-3 strands.     

External Rewriting for Skeptical Proof Assistants

This paper presents the design, the implementation, and experiments of the integration of syntactic, conditional possibly associative-commutative term rewriting into proof assistants based on constructive type theory. Our approach is called external because it consists in performing term rewriting in a specific and efficient environment and checking the computations later in a proof assistant. Two typical systems are considered in this work: ELAN, based on the rewriting calculus, as the term rewriting-based environment, and Coq, based on the calculus of inductive constructions as the proof assistant. We first formalize the proof terms for deduction by rewriting and strategies in ELAN using the rewriting calculus with explicit substitutions. We then show how these proof terms can soundly be translated into Coq syntax where they can be directly type checked. For the method to be applicable for rewriting modulo associativity and commutativity, we provide an effective method to prove equalities modulo these axioms in Coq using ELAN. These results have been integrated into an ELAN-based rewriting tactic in Coq.     

Coordinating optimization-based sliding mode variable structure control for electro-hydraulic servo system

A sliding mode variable structure control (SMVSC) based on a coordinating optimization algorithm has been developed. Steady state error and control switching frequency are used to constitute the system performance indexes in the coordinating optimization, while the tuning rate of boundary layer width (BLW) is employed as the optimization parameter. Based on the mathematical relationship between the BLW and steady-state error, an optimized BLW tuning rate is added to the nonlinear control term of SMVSC. Simulation experiment results applied to the positioning control of an electro-hydraulic servo system show the comprehensive superiority in dynamical and static state performance by using the proposed controller is better than that by using SMVSC without optimized BLW tuning rate. This succeeds in coordinately considering both chattering reduction and high-precision control realization in SMVSC.     

Real-time face detection and lip feature extraction using field-programmable gate arrays.

This paper proposes a new technique for face detection and lip feature extraction. A real-time field-programmable gate array (FPGA) implementation of the two proposed techniques is also presented. Face detection is based on a naive Bayes classifier that classifies an edge-extracted representation of an image. Using edge representation significantly reduces the model's size to only 5184 B, which is 2417 times smaller than a comparable statistical modeling technique, while achieving an 86.6% correct detection rate under various lighting conditions. Lip feature extraction uses the contrast around the lip contour to extract the height and width of the mouth, metrics that are useful for speech filtering. The proposed FPGA system occupies only 15050 logic cells, or about six times less than a current comparable FPGA face detection system.     

网络故障分析及排除方法

本文笔者从实际工作经验出发,阐述了如何对网络故障进行分析及排除方法。希望对广大网络管理员有借鉴作用。