基于CADDS5／DDM软件的冷冲模CAD系统

本文针对ＣＡＤＤＳ５／ＤＤＭ软件的特点，分析了冷冲模的设计特点与软件现状，结合模具设计师的实际需要和应用特点，就冷冲模ＣＡＤ系统中应用ＣＡＤ技术进行简要的论述和分析。系统以ＣＡＤＤＳ５／ＤＤＭ为软件平台，采用分布式的ＣＡＤ系统结构，使用图形菜单与文字菜单相结合的人机对话方式，特别对这套ＣＡＤ系统的实用性进行了论述。     

数据库在autoCAD中的应用

主要介绍了数据库在ａｕｔｏＣＡＤ环境中应用的一个实例，利用数据库同ａｕｔｏＣＡＤ软件之间的数据交换可为ａｕｔｏＣＡＤ增加自动绘制装配明细栏和产品明细表的功能。本文不仅为ａｕｔｏＣＡＤ增加了一个功能，重要的是提供了数据库与ａｕｔｏＣＡＤ连接的一种方法。     

CDMA系统的功率控制

功率控制功能在ＣＤＭＡ系统中起着重要的作用本文介绍并分析了ＣＤＭＡ系统的功率控制过程。     

FPGA在CDMA无绳PABX系统中的应用

本文简述了一种ＣＤＭＡ无绳ＰＡＢＸ系统，在其系统中采用ＦＰＧＡ，使产品小型化，低功耗，标准化，系列化。ＦＰＧＡ主要用来完成收发支路的速率转换，ＴＤＤ控制，组帧拆帧和ＣＲＣ校验等功能。本文还对ＦＰＧＡ的布线延时作了详尽的分析。     

如何为CAD系统增加新的功能

本文以为Ａｕｔｏｃａｄ系统中新增一浏览全图功能为例，阐述了为什么要为ＣＡＤ系统增加功能，以及怎样完成增加功能的要求。     

从cdmaOne到Cdma2000的无缝演进路径

在２０００年世界无线电大会上，第３代移动通信系统（３Ｇ）的地面系统被确定可使用５种无线传输技术，它们是ＣＤＭＡ－ＤＳ、ＣＤＭＡ－ＭＣ、ＣＤＭＡ－ＴＤＤ、ＴＤＭＡ－ＳＣ和ＴＤＭＡ－ＴＤＤ。其中前３种基于ＣＤＭＡ（码分多址）技术，后两种基于ＴＤＭＡ（时分多址）技术。可见，在３Ｇ标准中，ＣＤＭＡ是主流技术。ＣＤＭＡ（Ｃｏｄｅ Ｄｉｖｉｓｉｏｎ Ｍｕｌｔｉｐｌｅ Ａｃｃｅｓｓ）蜂窝系统由于采用了一种称之为扩频的通信技术，所以与采用ＴＤＭＡ和ＦＤＭＡ（频分多址）的ＧＳＭ蜂窝系统相比，具有抗干扰性好、系统容量…     

通用器材公司新一代1GHz调制器──C6M－Ⅱ－D／K－C

通用器材公司新一代１ＧＨｚ调制器──Ｃ６Ｍ－Ⅱ－Ｄ／Ｋ－Ｃ周航９Ｃ６Ｍ－ｌ－Ｄ／Ｋ－ＣＭＯＢ组件这个附件模块提供基带音视频输入开关，音视频ＡＧＣ功能，一个声音载波输入和附加的ＩＦ输入功能。视频开关系统包括视频Ａ信号感知系统，可以使系统在无视频信号输入...     

内嵌MCU的高性能、多通道12位采集系统ADuC812

ＡＤｕＣ８１２是带有８位可编程微控制器、多通道ＡＤＣ、双数／模转换器（ＤＡＣ）的高集成度１２位数据采集系统芯片。本文详细介绍了该芯片的功能特点和工作原理，并指出了应用范围。     

将CIMS技术引入到SMT生产线中来

ＳＭＴ生产线中的大多数加工设备均为数控设备。它们编程所需的大多数特征数据均可从ＣＡＤ设计系统中得到。如何在ＣＡＤ设计系统和ＳＭＴ自动化加工设备之间建立有机的信息联系和共享，正是ＣＩＭＳ技术所要解决的问题。因此，本文以ＣＩＭＳ系统中的ＣＡＤ／ＣＡＭ为重点，介绍了构造和设计一个电子ＣＡＤ／ＣＡＭ集成系统的方法和思路，以期以引导卢更多的同行加入到该的研究中来。     

微电子工艺器件计算机辅助设计及辅助教学交互系统

微电子ＣＡＤ（计算机辅助设计）＋ＣＡＩ（计算机辅助教学）ＦＯＲ ＷＩＮＤＯＷＳ ＰＣ交互系统的开发成功，对微电子ＣＡＤ技术的推广应用及高等学校的教学应用等各方面有着极及其重要的作用。本文介绍了该系统开发思路，结构与功能。     

砷化镓集成电路CAD系统

介绍了一个在ＳＵＮ工作站上自主开发的砷化镓集成电路ＣＡＤ系统。该系统可完成微波、毫米波集成电路ＣＡＤ及砷化镓超高速数字集成电路ＣＡＤ。应用该系统已完成１５０余种砷化镓集成电路的优化设计，取得良好效果。     

Automatic detection and quantification of tree-in-bud (TIB) opacities from CT scans

This study presents a novel computer-assisted detection (CAD) system for automatically detecting and precisely quantifying abnormal nodular branching opacities in chest computed tomography (CT), termed tree-in-bud (TIB) opacities by radiology literature. The developed CAD system in this study is based on 1) fast localization of candidate imaging patterns using local scale information of the images, and 2) M?bius invariant feature extraction method based on learned local shape and texture properties of TIB patterns. For fast localization of candidate imaging patterns, we use ball-scale filtering and, based on the observation of the pattern of interest, a suitable scale selection is used to retain only small size patterns. Once candidate abnormality patterns are identified, we extract proposed shape features from regions where at least one candidate pattern occupies. The comparative evaluation of the proposed method with commonly used CAD methods is presented with a dataset of 60 chest CTs (laboratory confirmed 39 viral bronchiolitis human parainfluenza CTs and 21 normal chest CTs). The quantitative results are presented as the area under the receiver operator characteristics curves and a computer score (volume affected by TIB) provided as an output of the CAD system. In addition, a visual grading scheme is applied to the patient data by three well-trained radiologists. Interobserver and observer-computer agreements are obtained by the relevant statistical methods over different lung zones. Experimental results demonstrate that the proposed CAD system can achieve high detection rates with an overall accuracy of 90.96%. Moreover, correlations of observer-observer (R(2)=0.8848, and observer-CAD agreements (R(2)=0.824, validate the feasibility of the use of the proposed CAD system in detecting and quantifying TIB patterns.     

CAD/CAM软件在电子组装领域中应用技巧实例

现在CAD/CAM软件已被广泛应用于电子行业上,摆在电子组装工艺技术人员面前一个很现实的问题就是如何从CAD/CAM系统中得到用于生产的必要数据,建立起CAD设计系统和自动化组装设备之间的有机联系,提高电子制造的效率和质量。文章以作者的经验为例,介绍了CAD/CAM软件在电子组装领域中的一些应用技巧实例。     

Extracting and using procedural knowledge in a CAD task

The declarative and procedural knowledge, or cognitive strategies, used by expert and novice CAD operators on a 3D design task are determined in order to understand how training and management of CAD operators could affect this knowledge. Results indicate that novices were variable in performance not because of differences in declarative knowledge (on which they were trained) but because of differences in procedural knowledge (on which no training was given). The design expert could transfer procedural knowledge from other systems to the CAD system tested. The system expert could perform fast, because of the highly developed declarative knowledge, without thinking about the strategies. This research indicates the need for attention by managers of CAD systems to procedural knowledge training for system experts and novice CAD operators; declarative knowledge training can be emphasized for design experts     

Computer-aided design in VLSI device development

Computer-aided design (CAD) has been used extensively in the development of VLSI MOS technology at Hewlett-Packard Laboratory. The CAD system for MOS device design is described. The development of the p-channel transistor with submicrometer channel length, trench isolation in CMOS, and side-wall-masked isolation (SWAMI) for VLSI technology are then presented, followed by a discussion of the techniques used in the simulation of parasitic capacitances in multilayer interconnects for circuit performance evaluations.     

“集成电路CAD”课程教学平台的构建

"集成电路CAD"是我院集成电路设计与集成系统专业的主干课程之一,涉及集成电路从设计到制造的专业知识和计算机辅助设计方法。我们在"集成电路CAD"课程建设及改革探索中,构建出双语教学等教学手段、课堂教学与课程设计相结合,辅助产学研合作教育的立体教学平台,将扎实理论基础、注重实践技能和紧跟市场需求的理念贯穿到整个教学活动过程中。     

Optimizing Case-based detection performance in a multiview CAD system for mammography

When reading mammograms, radiologists combine information from multiple views to detect abnormalities. Most computer-aided detection (CAD) systems, however, use primitive methods for inclusion of multiview context or analyze each view independently. In previous research it was found that in mammography lesion-based detection performance of CAD systems can be improved when correspondences between MLO and CC views are taken into account. However, detection at case level detection did not improve. In this paper, we propose a new learning method for multiview CAD systems, which is aimed at optimizing case-based detection performance. The method builds on a single-view lesion detection system and a correspondence classifier. The latter provides class probabilities for the various types of region pairs and correspondence features. The correspondence classifier output is used to bias the selection of training patterns for a multiview CAD system. In this way training can be forced to focus on optimization of case-based detection performance. The method is applied to the problem of detecting malignant masses and architectural distortions. Experiments involve 454 mammograms consisting of four views with a malignant region visible in at least one of the views. To evaluate performance, five-fold cross validation and FROC analysis was performed. Bootstrapping was used for statistical analysis. A significant increase of case-based detection performance was found when the proposed method was used. Mean sensitivity increased by 4.7% in the range of 0.01-0.5 false positives per image.     

Electronic CAD frameworks

The CAD framework, i.e. the underlying facilities provided to the CAD tool developer, the CAD system integrator, and the end-user (IC or system designer) to facilitate their tasks, is discussed. The development of the CAD framework concept in the domain of electronic circuit design is reviewed. The most important work in the area is briefly described. The major components of a CAD framework are identified, and the requirements and desirable features of these components are described in some detail. Many of the key engineering tradeoffs required to build CAD frameworks are examined, using examples from existing CAD systems. Framework standardization efforts are also reviewed     

IC－CAD领域中软件的复用

本文首先提出了软件复用是当今提高ＩＣ－ＣＡＤ领域中软件的高效率和实用性的一种重要方法，叙述了它在ＩＣ－ＣＡＤ领域中的应用前景；接着在此基础之上给出了一个ＩＣ软件复用系统的模型，并认为ＩＣ－ＣＡＤ领域中的软件标准化可以通过这样的系统而得以实施与推广。然而，本文就软件复用实施过程中的三个瓶颈问题──外来软件实例的理解和软构件的特征提取、软构件库的结构和软构件的获取、系统在软构件基础之上的综合过程，给出了它们在ＩＣ－ＣＡＤ领域中的可行的途径。这些方法已经部分在ＩＣ－ＣＡＤ软件工具开发及系统集成的集成化环境ＩＣＳＤＥ（ＩＣ－ＣＡＤＳｏｆｔ－ｗａｒｅＤｅｖｅｌｏｐｍｅｎｔＥｎｖｉｒｏｎｍｅｎｔ）系统中实现。     

将CIMS技术引入到PCB组装中来

PCB板组装生产线中的大多数加工设备均为数控设备。它们编程所需要的大多数特征数据均可从CAD设计系统中得到。如何在CAD设计系统和自动化加工设备之间建立起有机的联系和共享,正是CIMS所要解决的问题。因此,文章以CIMS系统中的CAD／CAM为重点,介绍了构造和设计一个电子CAD／CAM集成系统的方法和思路,以期引起更多的同行加入到该技术的研究中来。