电阻层析成象系统的研究

１前言电阻层析成象技术是电阻抗层析成象技术的简化情况。自八十年代末由医学工程中的ＣＴ技术移植于工业过程成象领域以来,电阻层析成象技术获得迅猛发展。正逐渐由基础原理性研究向应用性研究转化。电阻层析成象技术是一种非侵入、接触式测量技术,它利用场域边界测量...     

医学图象技术的发展与应用

医学是图象图形技术的一个重要而又广阔的应用领域，从而使基学图像成为图形技术的一个重要分支，本文向医学图象形领域的工作者，特别是工作于医院和医学领域的医生与技术人员介绍医学图像技术的基本内涵，包括医学成象技术的发展过程，医学图象技术的研究内容，以及医学图象技术的发展趋势，特别是与实际应用密切相关的医学图象技术的发展趋势，以利于提高医学图象技术的应用水平。     

磁共振血管成象技术及实现

本文探讨磁共振在血管成象方面的技术及其实现方法，磁共振血管成象（MRA）可以抑制人体的静止组织而仅仅表现血管信息，并介绍了这种技术的临床应用，背景知识，成象方法及脉冲序列等等。目前磁共振血管成象可分二类：一类称为渡越时间（TOF）方法，这种方法利用血液流入，流出成象平面对磁共振信号幅度的影响，另一类称为相位对比（PC）方法，这种方法利用流体的磁共振信号感应的相移，在我们自己生产的低场磁共振系统上，设计了专门的磁共振血管成象脉冲序列，可以分别得到人体动脉，静脉和动静脉血管图象，实验结果令人满意，最后讨论了实现MRA的有关困难。     

12电极ECT系统的计算机接口实现

ＥＣＴ（电容层析成象）技术是８０年代末发展的一种新的层析成象技术。本文提出了一种适用于１２电极ＥＣＴ系统的低噪声、低漂移的电容测量电路及计算机接口电路，并介绍了利用该接口电路对测量通道的逻辑控制和图象重建数据的采集方法及实现。     

提取医学图像局部特征的方法与实现

随着X光医学成像技术的进步和发展,医学图像处理在医学研究与临床医学中的应用越来越广泛。与一般意义上的图像处理比较,医学图像处理有其特殊性和不同的侧重点,X光成像的目的是要让医生能够观察到被检者体内的某个病变组织或器官及其状况,所以医学图像处理更侧重于提取某一个组织或器官的特征。但由于X光图像不像光学图像那样聚焦,图像会略显模糊,再加上人体各种组织和器官纵横交错,很难分辨出某单个组织或器官的细节。目前急需提供一种从人体X光图像中提取某个组织或器官清晰特征的方法,为医生诊断该组织或器官疾病提供方便。因此可以通过提取医学图像的局部细节,凸显病变组织或器官特征。     

基于FPGA的生物电阻抗成像系统设计

根据电阻抗断层成像技术要求,设计了以Spartan3E系列XC3S500E FPGA为核心的16电极生物电阻抗成像系统,系统嵌入8 bit微处理器PicoBlaze实现逻辑控制并产生激励信号实现高速A/D采集及实现数字解调,通过RS232将采集数据传输到PC机,重建人体内部的电阻率分布或其变化图像。为广泛应用研究电阻抗断层成像技术提供一种硬件设计方案。     

直接辐射成象(DR)在常规X光医学诊断中的应用

0　引　言近年来 ,医学影像的数字化进程十分迅速 ,如CT、核磁等 ,而历史悠久的常规 X光透视和曝光仍大量采用胶片成象 ,仅辅助使用少量的 CR( computer radiography)和影象增强器数字化点片 .这种基于胶片成象的数字化 ,需采用数字化胶片扫描仪 ,且这个过程成本高、效率低 ;而 CR是近年发展起来的一种常规 X光成象技术 ,它是先把 X光成象在一个影象板上 ,然后通过用激光扫描该影象板来获得数字图象 ,但由于二次曝光 ,致使图象质量下降 ,并且 CR设备十分昂贵 ;影象增强器数字化点片技术是用 CCD相机或摄像管来采集已通过影象增强器 ,…     

医学体数据的三维测量技术研究

医学体数据的三维测量技术是计算机可视化、图像分割与测量等技术在生物医学工程上的重要应用,它提供了一种对器官组织进行三维观察、分析和测量的技术手段,在医学临床与医学研究中具有重要意义.通过医学体数据的分割技术将特定的器官组织(如病灶区)分割出来进行三维测量,为医学诊治和研究提供可靠的数据分析.     

适用于多模式虚拟学习的交互医学可视化及模拟

医学图像及其衍生的知识是医学教育中的一个关键学习部分，透过不同的图像模式，町以使医生及医科学生更有效地学习人体的体内结构．而计算机可视化技术最近的发展正满足了医生、外科医生及医科学生与日俱增的需求，为深入地了解人体生理学及病理学提供了宝贵的资料．本文提出了一个网上交互医学学习系统，并提供了一个虚拟现实工具包以支持二维医学图像序列观察、体数据和表面数据的三维可视化、目视放大镜．以及医学数据的交互变形模拟．其中人体组织物理特性的模拟以有限元法为基准．通过优化而获得有关的变形模型参数．该工具包可应用于个性化的二维及三维数据场可视化、优化的学习及手术规划和在线的交互医学教育．     

用于重建流体分布的多电极电容层析成象方法

一种用于两种成份流体成象的多电极电容层析成象系统的有限元模型和成象方法,当已知流体成份分布 时"用有限元方法求出电极对之间的电容值,并用该方法计算出系统的灵敏度分布,以此作为先验知识用反投影法 重建出流体成份的分布图象.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.