Technology CAD

Usability in virtual reality based design tools (VRAD) is a major issue since its interaction techniques
are not yet fully investigated. Human factors such as pointing precision, fatigue, hand vibrations, lack
of limb support, and interaction anisotropy should be taken into account for a more effective interface
as compared to the 2D. This work presents an ongoing study addressing human performances in VR
during common CAD tasks: picking, pointing, and line drawing. Tests confirm performances
reduction along the user’s head to hand direction, mainly due to occlusion and lack of appropriate
feedback. Three virtual tools are here presented in order to overcome the interaction anisotropy: the
“Ortho Tool”, the “Smart Transparency”, and the “Smart Object Snap”. The new interface has shown
better user performances and improved model understanding. Results achieved in this work contribute
not only toVRAD development, but also to other virtual reality applications, because their context can
be easily extended.

A simulation technique is developed in TCAD to study the non-linear behavior of RF power transistor. The technique is based on semiconductor transport equations to swot up the overall non-linearity's occurring in RF power transistor. Computational load-pull simulation technique (CLP) developed in our group, is further extended to study the non-linear effects inside the transistor structure by conventional two-tone RF signals, and initial simulations were done in time domain. The technique is helpful to detect, understand the phenomena and its mechanism which can be resolved and improve the transistor performance. By this technique, the third order intermodulation distortion (IMD 3 ) was observed at different power levels. The technique was successfully implemented on a laterally-diffused field effect transistor (LDMOS). The value of IMD 3 obtained is -22 dBc at 1-dB compression point (P 1 dB ) while at 10 dB back off the value increases to -36 dBc. Simulation results were experimentally verified by fabricating a power amplifier with the similar LDMOS transistor.

The use of monolithic construction in building high-rise residential buildings in most cities have gained wide spread acceptance by scholars and practitioners in the building construction industry. The complexity of calculation of high-rise building requires search for better methodological approaches to construct such long lasting high-rise buildings. For this reason, technological advancement has made it possible to use Computer-Aided Design (CAD) software package to design and undertake structural calculations. The purpose of this research is to make computer modeling study of elastic and firm base multi-storey buildings and conduct feasibility studies of applying their computational schemes. The research design was exploratory and made use of Complex Program (CP) Lira to design and calculate 18-storey residential buildings with basement.

Rapid modeling and optimization of manufacturing processes, devices, and circuits are required to support modern integrated circuit technology development and yield improvement. We have prototyped and applied an integrated system, called DOE/Opt, for performing Design of Experiments (DOE), Response Surface Modeling (RSM), and Optimization (Opt). The system to be modeled and optimized can be either physical or simulation based. Within the DOE/Opt system, coupling to external simulation or experimental tools is achieved via an embedded extension language based on Tcl. The external problem then appears to DOE/Opt as a model with user defined inputs and outputs. DOE/Opt is used to generate splits for experiments, to dynamically build and evaluate regression models from experimental runs, and to perform nonlinear constrained optimizations using either regression models or embedded executions. The intermediate regression modeling can appreciably accelerate the optimization task when simulation or physical experiments are expensive. The primary application of DOE/Opt has been to process optimization using coupled process and device simulation. DOE/Opt has also been applied to process and device simulator tuning, and to aid in device characterization. Such a DOE/Opt system is expected to augment the use of TCAD tools and to utilize data collected by CIM systems in support of process synthesis. We have demonstrated the application of the system to process parameter determination, simulator tuning, process control modeling, and statistical process optimization. We are extending the system to more fully support emerging device design and process synthesis methodologies.

Usability in virtual reality based design tools (VRAD) is a major issue since its interaction techniques are not yet fully investigated. Human factors such as pointing precision, fatigue, hand vibrations, lack of limb support, and interaction anisotropy should be taken into account for a more effective interface as compared to the 2D. This work presents an ongoing study addressing human performances in VR during common CAD tasks: picking, pointing, and line drawing. Tests confirm performances reduction along the user's ...

The purpose of this research is to examine the effect of integrating mobile and CAD technology on designing process of Malaysian polytechnic architecture students. This study utilized a quasi-experimental method. The sample comprises of sixty students in both the treatment group and in the control group. Results show that there is a significant difference between the treatment group product and control group product. This research contributes to the use of an architectural website, the use of mobile technology as media information sources, the use of CAD technology integration in designing process and the construction of validated instrument.

To implement high-performance global interconnect without impacting the placement and performance of existing blocks, the use of buffer blocks is becoming increasingly popular in structured-custom and block-based application specified integrated circuit methodologies. Recent works by Cong et al. (1999) and give algorithms to solve the buffer block planning problem. In this paper, we address the problem of how to perform the buffering of global multiterminal nets given an existing buffer block plan. We give provably good and heuristic algorithms for this problem based on a recent approach of Garg and Könemann (1998)

Since its establishment in 1982, the Semiconductor Research Corporation (SRC) has funded extensive silicon-based semiconductor research at universities, including research in the area of computer aided design. While the consortium has had success with transferring this research to its members, the overall incidence of transfer has been limited. This study explored the key issues affecting the transfer of university computer-aided design (CAD) technology from the SRC CAD Center at Carnegie Mellon University to the SRC's industrial membership. Most research on improving technology transfer has focused on finding mechanisms to promote person-to-person interaction between developer and adopter. Interview and survey data collected from the 12 CAD Center faculty and 15 SRC member firm personnel suggest that transfer succeeds only when SRC member firms establish organizational incentives for technical personnel to commit their time to the implementation of university research, and when they provide these personnel the organizational resources needed to perform this implementation. Suggestions for improving the mechanisms of transfer are offered, but without reform in organizational incentives, improving these mechanisms is unlikely to significantly increase the rate at which university research is commercialized for actual industrial use.

The purpose of this research is to examine the effect of integrating mobile and CAD technology on designing process of Malaysian polytechnic architecture students. This study utilized a quasi-experimental method. The sample comprises of sixty students in both the treatment group and in the control group. Results show that there is a significant difference between the treatment group product and control group product. This research contributes to the use of an architectural website, the use of mobile technology as media information sources, the use of CAD technology integration in designing process and the construction of validated instrument.

A simulation technique is developed in TCAD to study the non-linear behavior of RF power transistor. The technique is based on semiconductor transport equations to swot up the overall non-linearity's occurring in RF power transistor. Computational load-pull simulation technique (CLP) developed in our group, is further extended to study the non-linear effects inside the transistor structure by conventional two-tone RF signals, and initial simulations were done in time domain. The technique is helpful to detect, understand the phenomena and its mechanism which can be resolved and improve the transistor performance. By this technique, the third order intermodulation distortion (IMD 3) was observed at different power levels. The technique was successfully implemented on a laterally-diffused field effect transistor (LDMOS). The value of IMD 3 obtained is −22 dBc at 1-dB compression point (P 1 dB) while at 10 dB back off the value increases to −36 dBc. Simulation results were experimentally verified by fabricating a power amplifier with the similar LDMOS transistor.

A simulation technique is developed in TCAD to study the non-linear behavior of RF power transistor. The technique is based on semiconductor transport equations to swot up the overall non-linearity's occurring in RF power transistor. Computational load-pull simulation technique (CLP) developed in our group, is further extended to study the non-linear effects inside the transistor structure by conventional two-tone RF signals, and initial simulations were done in time domain. The technique is helpful to detect, understand the phenomena and its mechanism which can be resolved and improve the transistor performance. By this technique, the third order intermodulation distortion (IMD 3) was observed at different power levels. The technique was successfully implemented on a laterally-diffused field effect transistor (LDMOS). The value of IMD 3 obtained is −22 dBc at 1-dB compression point (P 1 dB) while at 10 dB back off the value increases to −36 dBc. Simulation results were experimentally verified by fabricating a power amplifier with the similar LDMOS transistor.

Abstract Usability in virtual reality based design tools (VRAD) is a major issue since its interaction techniques are not yet fully investigated. Human factors such as pointing precision, fatigue, hand vibrations, lack of limb support, and interaction anisotropy should be taken into account for a more effective interface as compared to the 2D. This work presents an ongoing study addressing human performances in VR during common CAD tasks: picking, pointing, and line drawing. Tests confirm performances reduction along the user's ...

In AEC practice as well as in academic settings the use of 3-dimensional digital building models is becoming increasingly prevalent, and the models used tend to be increasingly large and complex. While the use of such models is to some extent enabling collaborative processes of design, analysis, communication and decision-making which were not feasible previously - when analog and 2D digital representations were the norm - it has been widely observed that the use of these 3D models also poses some significant difficulties, particularly regarding the exchange of models in multi-party, multi-disciplinary design processes. The types of and reasons for these difficulties are numerous and varied, but the one of specific interest here concerns the ways in which the data contained in these models is organized and retrieved. The present paper addresses these two interlinked issues and proposes some improvements to the current state of affairs by way of geometric-content-based methods for analyzing and querying the model objects, which can complement the existing text- and other assigned-attribute-based methods commonly employed. Some basic considerations regarding geometric-content-based search and classification are presented, followed by description of tests carried out to assess the implementation of some proposed methods and discussion of the test results' implications for further work in this area.