Object boundary location by region and contour deformation

Many applications in image analysis need to distinguish an object from its surroundings. The `snake' method (Kass, 1987) is a well known method to solve such problems by locating the object boundary from an initial plan, but it has the limitation that the distance between the initial plan and the object boundary should be `very small'. The authors present a two-step method, which combines region and contour deformation, to locate the boundary of an object from a designated initial boundary plan. First, they propose a new deformable region model to represent an object, and use the model to locate the boundary of the object by region deformation. This step fills the gap between a fairly rough initial plan and the `snake' method. The resulting boundary is then used as the initial plan of a `snake' method to further refine the boundary. The results of the method are shown in simulated images and MRI images of brain tumour patients     

A method for the preparation of PMMA-SiO2 nanocomposites with high homogeneity

It is possible to optimize the performance of the inorganic-organic composites dispersing the inorganic component in the organic matrix on a nanomiter length scale. If dry the inorganic phase cannot be intimately dispersed during the incorporation in the matrix. When the particle surface is organically modified, and the incorporation is made starting from a liquid dispersion (particles in polymer solution), the resulting composites exhibit an excellent homogeneity. Here, monolithic [poly(methyl methacrylate)/monodisperse silica particles] nanocomposites have been prepared and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), micro-hardness, and differential scanning calorimetry (DSC).     

The influence of the alloying elements upon the transformation kinetics and morphologies of ferrite plates in alloy steels

A series of Fe-C-X and Fe-C-X₁-X₂ alloys in which X, X₁ and X₂ either raise or depress the activity of C iny were investigated by autodilatometer, optical microscopy, and transmission electron microscopy (TEM) to reveal the relations among the chemical composition, transformation kinetics, and morphology of ferrite plates. The incubation time of austenite decomposition at the nose temperature in the time-temperature-transformation (TTT) diagrams, the concentration of C in y in contact with theα/gg boundary, and the growth rate of ferrite were evaluated to estimate the magnitude of the solute drag-like effect (SDLE) for the different alloying elements used. All the results are consistent qualitatively with the SDLE hypothesis. This article is based on a presentation made at the Pacific Rim Conference on the “Roles of Shear and Diffusion in the Formation of Plate-Shaped Transformation Products,” held December 18-22, 1992, in Kona, Hawaii, under the auspices of ASM INTERNATIONAL’S Phase Transformations Committee.     

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本文通过对在用钻机井架的现场实际测试,建立数据库、测评模型,对实测的数据用计算机技术进行分析,提出了初始弯曲应力;数据正态分布检验——x～2检验;建立回归方程;在给定置信度下测评当前承载能力的技术概念。解决了在用钻机A型井架的安全性评估问题,是一种较为合理、可靠、科学的测评技术和方法。     

多人决策的一类相对均衡解

本文分析由于决策人偏好不同而引起决策差异的多人多目标决策问题，提出了这类决策问题的一类相对均衡解的概念和求取方法。相对均衡解以决策群体偏好的加权集结为基础，能最大程度地反映每个决策人的偏好。文中研究相对均衡解的ＳＷＴ求取方法，并给出了求解的步骤。     

光电摆角动态测量原理及其测量系统

本文阐述了用于测量物体摆角及摆心浮动量的光电动态实时测量原理,以及根据此原理研制的光电导弹喷管摆角动态测量系统。     

一种新型润滑油添加剂的质谱研究

采用独特的分离方法和途径，综合使用多种质谱分析技术，如电子轰击谱（ＥＩ／ＭＳ）、场解吸谱（ＦＤ／ＭＳ）、快速原子轰击谱（ＦＡＢ／ＭＳ）、色／质联用等，对高档齿轮油的主剂－含磷极压剂的结构组成进行了较为详尽的分析研究，提出了复酯胺盐的结构组成。     

Beam test of the CsI(Tl) calorimeter for the BELLE detector at the KEK-B factory

We studied the performance of a prototype electromagnetic calorimeter for the BELLE detector at the KEK proton synchrotron for an energy range of 0.25–3.5 GeV. The prototype consisted of an array of 6 × 5 CsI(Tl) crystals with 30 cm length (16.2 radiation lengths) and about 6 cm × 6 cm cross section. The scintillation light of each CsI(Tl) crystal was read out by two large-area PIN photodiodes and charge-sensitive preamplifiers attached at the rear face of the crystal. We measured the energy and position resolution for electrons and the e/π separation for two sets of matrix configurations: one corresponded to the center and the other to the edge of the barrel calorimeter. The overall performance measured by the test proves that the prototype calorimeter is satisfactory for the use in the BELLE detector.     

ATM技术浅析

网络通信技术正在迅猛地发展，各种各样的高速通信技术如雨后春笋，其中ＡＴＭ作为一种信元换技术，具有以兆或千兆级速率传送话音、数据和图象的能力，它在网络通信技术中占有特别重要的地位。本文介绍了ＡＴＭ技术的产生、基本特点、体系结构、在ＢＩＳＤＮ中的作用、存在的问题以及发展前景。