Browsing by Subject "Computer aided design"

Now showing 1 - 20 of 21

Open Access
Attitudes of design students toward computer usage in design
(Springer Netherlands, 2006-01) Pektaş, S. T.; Erkip, F.
The success of efforts to integrate technology with design education is largely affected by the attitudes of students toward technology. This paper presents the findings of a research on the attitudes of design students toward the use of computers in design and its correlates. Computer Aided Design (CAD) tools are the most widely used computer applications in design. An instrument was developed and applied for the first time to relate computer attitude to design field through CAD. Interior architecture undergraduates of Bilkent University participated in the survey. As a result, students' attitudes toward the use of computers in design were found to be positive. A significant gender difference in attitudes toward computers was observed with males having more positive attitudes than females. The results also revealed that students' attitude toward computer usage in design was highly related to their general attitude toward computers, but it was not correlated with their perception of instructors' attitude toward the use of computers in design. © Springer 2006.
Open Access
Design of a novel MRI compatible manipulator for image guided prostate interventions
(IEEE, 2005-02) Krieger, A.; Susil, R. C.; Ménard, C.; Coleman, J. A.; Fichtinger, G.; Atalar, Ergin; Whitcomb, L. L.
This paper reports a novel remotely actuated manipulator for access to prostate tissue under magnetic resonance imaging guidance (APT-MRI) device, designed for use in a standard high-field MRI scanner. The device provides three-dimensional MRI guided needle placement with millimeter accuracy under physician control. Procedures enabled by this device include MRI guided needle biopsy, fiducial marker placements, and therapy delivery. Its compact size allows for use in both standard cylindrical and open configuration MRI scanners. Preliminary in vivo canine experiments and first clinical trials are reported.
Open Access
Dynamic thread and data mapping for NoC based CMPs
(IEEE, 2009-07) Kandemir, M.; Öztürk, Özcan; Muralidhara, S. P.
Thread mapping and data mapping are two important problems in the context of NoC (network-on-chip) based CMPs (chip multiprocessors). While a compiler can determine suitable mappings for data and threads, such static mappings may not work well for multithreaded applications that go through different execution phases during their execution, each phase with potentially different data access patterns than others. Instead, a dynamic mapping strategy, if its overheads can be kept low, may be a more promising option. In this work, we present dynamic (runtime) thread and data mappings for NoC based CMPs. The goal of these mappings is to reduce the distance between the location of the core that requests data and the core whose local memory contains that requested data. In our experiments, we evaluate our proposed thread mapping and data mapping in isolation as well as in an integrated manner. Copyright 2009 ACM.
Open Access
Effects of cognitive styles on 2D drafting and design performance in digital media
(Springer Netherlands, 2010) Pektas, S.T.
This paper investigates the interactions between design students' cognitive styles, as measured by Riding's Cognitive Styles Analysis, and performance in 2D drafting and design tasks in digital media. An empirical research revealed that Imager students outperformed Verbalisers in both drafting and creativity scores. Wholist-Analytic cognitive style dimension was found to be independent from drafting and design performance. The study suggests that examining the cognitive styles of students in Computer Aided Design (CAD) education deserves further attention and may facilitate for improvements in learning processes. © 2008 Springer Science+Business Media B.V.
Open Access
Efficient and accurate EM simulation technique for analysis and design of MMICs
(John Wiley & Sons, Inc., 1997) Kınayman, N.; Aksun, M. I.
A numerically efficient technique for the analysis and design of MMIC circuits is introduced and applied to some realistic problems. The formulation is based on the method of moments (MoM) in the spatial domain, and utilizes closed-form Green's functions. Incorporating the closed-form Green's functions into the MoM has resulted in an efficient and accurate CAD algorithm. This is because use of the closed-form Green's functions not only eliminates the calculation of the spatial-domain Green's functions, but also makes it possible to evaluate the MoM matrix elements analytically We have demonstrated the application of this method here for some stripline and microstrip geometries, and compared the results with those obtained from commercial EM software, em (Sonnet Software, Inc.)
Open Access
Fast ray tracing 3D models
(1991) İşler, Veysi; Özgüç, Bülent
In many computer graphics applications such as CAD, realistic displays have very important and positive effects on the users of the system. There are several techniques to generate realistic images with the computer. Ray tracing gives the most effective results by simulating the interaction of light with its environment. However, it may require an excessive amount of time to generate an image. In this article, we present a survey of methods developed to speed up the ray tracing algorithm and introduce a fast ray tracer to process a 3D scene that is defined by interactive 3D modeling software.
Open Access
Geometric computing and uniform grid technique
(Elsevier, 1989) Akman, W.; Franklin, W. R.; Kankanhalli, M.; Narayanaswami, C.
If computational geometry should play an important role in the professional environment (e.g. graphics and robotics), the data structures it advocates should be readily implemented and the algorithms efficient. In the paper, the uniform grid and a diverse set of geometric algorithms that are all based on it, are reviewed. The technique, invented by the second author, is a flat, and thus non-hierarchical, grid whose resolution adapts to the data. It is especially suitable for telling efficiently which pairs of a large number of short edges intersect. Several of the algorithms presented here exist as working programs (among which is a visible surface program for polyhedra) and can handle large data sets (i.e. many thousands of geometric objects). Furthermore, the uniform grid is appropriate for parallel processing; the parallel implementation presented gives very good speed-up results. © 1989.
Open Access
Hardware accelerator design for data centers
(IEEE, 2016-11) Yeşil, Şerif; Özdal, Muhammet Mustafa; Kim, T.; Ayupov, A.; Burns, S.; Öztürk, Özcan.
As the size of available data is increasing, it is becoming inefficient to scale the computational power of traditional systems. To overcome this problem, customized application-specific accelerators are becoming integral parts of modern system on chip (SOC) architectures. In this paper, we summarize existing hardware accelerators for data centers and discuss the techniques to implement and embed them along with the existing SOCs. © 2015 IEEE.
Open Access
Heterogeneous inference in design
(Publ by ASME, New York, NY, United States, 1992) Akman, Varol
For those of us involved in the attempt to construct formal models and environments in which the world of design can be subjected to scientific experimentation, the raison d'etre of logic has been rather well-understood. The aim of this position paper is not really to challenge this view but rather to complement and extend it. Specifically, we discuss why heterogeneous inference - inference that proceeds from information represented in more than one form - is crucial.
Open Access
An insight on designers’ sketching activities in traditional versus digital media
(Pergamon Press, 2003-01) Bilda, Z.; Demirkan, H.
This study aims at gaining an insight on designers' cognitive processes while sketching in digital vs traditional media. Empirical data on design processes have been obtained from protocol analyses of six interior designers solving an interior space-planning problem through media transition. In order to encode the design behavior, a coding scheme was utilized that allowed the inspection of both the design activity and the responses to media transition in terms of the primitive cognitive actions of designers. The analyses of the coding scheme constituents, which are segmentation and cognitive action categories, allowed a comparative study demonstrating the effect of the use of different media in the conceptual design phase. The results showed that traditional media had advantages over the digital media, such as supporting the perception of visual-spatial features, and organizational relations of the design, production of alternative solutions and better conception of the design problem. These results also suggested implications for computer aids in architectural design to support the conceptual phase of the design process.
Open Access
JPEG hardware accelerator design for FPGA
(IEEE, 2007) Duman, Kaan; Çoǧun, Fuat; Öktem, L.
A fully pipelined JPEG hardware accelerator that runs on FPGA is presented. The accelerator is designed interactively in a simulation environment, using a DSP hardware design automation tool chain. The encoder part of the accelerator accepts 8×8 image blocks in a streaming fashion, and outputs the zigzag-scanned, quantized 2-D DCT coefficients of the block. The decoder part accepts zigzag-scanned, quantized DCT coefficients, and outputs reconstructed 8×8 image block. Each part has a throughput of one system clock per pixel per channel. The encoder employs a fast pipelined implementation for 2-D DCT [1]. For the decoder, a new pipelined 2-D IDCT structure is developed. Our IDCT structure is based on an IDCT factorization for software implementation [2], and is inspired by the pipelined DCT structure employed in the encoder. The resource utilization and maximum frequency figures for a particular FPGA target suggest that our accelerator has competitive performance.
Open Access
A new effective side length expression obtained using a modified tabu search algorithm for the resonant frequency of a triangular microstrip antenna
(John Wiley & Sons, 1998) Karaboğa, D.; Güney, K.; Kaplan, A.; Akdağli, A.
A new, very simple curve-fitting expression for the effective side length is presented for the resonant frequency of triangular microstrip antennas. It is obtained using a modified tabu search algorithm, and is useful for the computer-aided design (CAD) of microstrip antennas. The theoretical resonant frequency results obtained using this new effective side length expression are in very good agreement with the experimental results available in the literature.
Open Access
A novel algorithm for DC analysis of piecewise-linear circuits: popcorn
(IEEE, 1994) Topçu, S.; Ocalı, O.; Atalar, Abdullah; Tan, M. A.
A fast and convergent iteration method for piecewise-linear analysis of nonlinear resistive circuits is presented. Most of the existing algorithms are applicable only to a limited class of circuits. In general, they are either not convergent or too slow for large circuits. The new algorithm presented in the paper is much more efficient than the existing ones and can be applied to any piecewise-linear circuit. It is based on the piecewise-linear version of the Newton-Raphson algorithm. As opposed to the Newton-Raphson method, the new algorithm is globally convergent from an arbitrary starting point. It is simple to understand and it can be easily programmed. Some numerical examples are given in order to demonstrate the effectiveness of the proposed algorithm in terms of the amount of computation. © 1994 IEEE
Open Access
An ontology-based universal design knowledge support system
(Elsevier, 2011-05) Afacan, Yasemin; Demirkan, H.
An effective and efficient knowledge support system is crucial for universal design process, as it has become a major design issue in the last decade with the growth of the elderly population and disabled people. There are a limited number of CAD investigations on the nature of knowledge processing that supports the cognitive activities of universal design process. Therefore, this paper proposes an ontology-based computer-assisted universal design (CAUD) plug-in tool that supports designers in developing satisfactory universal design solutions in the conceptual design phase. The required knowledge processing and representation of the developed tool is motivated by the ontological language. It is based on the multiple divergence-convergence cognitive strategies and cognitive needs of designers in the analysis/synthesis/evaluation operations. The CAUD plug-in tool is the first attempt to interface the universal design knowledge ontologically and respond to the requirements of conceptual design phase. According to the user acceptance study, the tool is assessed as useful, understandable, efficient, supportive and satisfactory.
Open Access
The shifting tides of academe: oscillation between hand and computer in architectural education
(Springer Netherlands, 2006-09) Şenyapili, B.; Basa Ý.
There is a current vacillation in choosing hand or computer for design presentation in academia. Although the computer emerged as very powerful alternative presentation medium, it could not sweep away the hand totally. Believing that this vacillation cannot only be due to the positive and negative aspects of both media, we worked with a group of students in a design curriculum to observe the factors that affect their choice of medium for presenting design ideas. The students were required to use both media for the same task, subsequently their satisfaction and evaluation were examined through a questionnaire. Students acknowledged the positive aspects of both media, rather than accumulating on one side. Findings led us to concur that the constant oscillation of architecture between art and science penetrates down to the individual choice of presentation medium. We assert that the warmness of hand is not deserted as it contemplates the artistic essence, while the digital perfection of the computers flirt with science. The ever-attended, age-old question of architecture's being art and/or science occupies the architectural agenda at various levels. Both the polarizations and the reconciliations have theoretical, practical and educational consequences. This paper locates itself within this context and proposes a new framework for analyzing the impacts of this oscillation in design presentation, concluding that the future of presentation in education points to the coexistence of both media.
Open Access
SPM management using markov chain based data access prediction
(IEEE, 2008-11) Yemliha, T.; Srikantaiah, S.; Kandemir, M.; Öztürk, Özcan
Leveraging the power of scratchpad memories (SPMs) available in most embedded systems today is crucial to extract maximum performance from application programs. While regular accesses like scalar values and array expressions with affine subscript functions have been tractable for compiler analysis (to be prefetched into SPM), irregular accesses like pointer accesses and indexed array accesses have not been easily amenable for compiler analysis. This paper presents an SPM management technique using Markov chain based data access prediction for such irregular accesses. Our approach takes advantage of inherent, but hidden reuse in data accesses made by irregular references. We have implemented our proposed approach using an optimizing compiler. In this paper, we also present a thorough comparison of our different dynamic prediction schemes with other SPM management schemes. SPM management using our approaches produces 12.7% to 28.5% improvements in performance across a range of applications with both regular and irregular access patterns, with an average improvement of 20.8%.
Open Access
Toward an optimal foundation architecture for optoelectronic computing. Part I: Regularly interconnected device planes
(Optical Society of America, 1997-08-10) Özaktaş, Haldun M.
By systematically examining the tree of possibilities for optoelectronic computing architectures and offering arguments that allow one to prune suboptimal branches of this tree, I come to the conclusion that electronic circuit planes interconnected optically according to regular connection patterns represent an alternative that is reasonably close to the best possible, as defined by physical limitations. Thus I propose that this foundation architecture should provide a basis for future research and development in this area.
Open Access
Turkey: a report on computer graphics education
(Technews, 1996) Özgüç, B.
In a formal or an informal manner, computer graphics has been a field of research and education since the early 1970s in Turkey. The earlier examples of academic research work came from Istanbul Technical University and Middle East Technical University in Ankara. Istanbul Technical University research efforts were basically on computer-aided design, whereas at the Middle East Technical University, more theoretical computer graphics work has been carried on.Two examples can be given of early theoretical graphics work: A hidden line elimination algorithm by Ibrahim Canbulat, and an automated drafting algorithm by the author [2, 3]. To the best of my knowledge, the earliest official computer graphics course was offered at the Middle East Technical University in 1979. With the establishment of Bilkent University in Ankara, the first private university in Turkey, computer graphics became an official track of study, not only in computer engineering, but in fine arts as well.In this paper, we examine the current state of computer graphics education in Turkey under two main headings. First, the educational activities within the departments of computer science will be examined. Then, the educational activities within the schools of art and design will be looked at. In order to find out the educational activities at various universities, we have written to 52 departments at 40 universities. The information given in this report is based on the responses from these departments. Many departments at various schools offer technical drawing courses by the use of drafting software. These have not been classified as computer graphics courses.
Open Access
VISIBIOweb: visualization and layout services for BioPAX pathway models
(Oxford University Press, 2010-06-01) Dilek, Alptuğ; Belviranlı, Mehmet E.; Doğrusöz, Uğur
With recent advancements in techniques for cellular data acquisition, information on cellular processes has been increasing at a dramatic rate. Visualization is critical to analyzing and interpreting complex information; representing cellular processes or pathways is no exception. VISIBIOweb is a free, open-source, web-based pathway visualization and layout service for pathway models in BioPAX format. With VISIBIOweb, one can obtain well-laid-out views of pathway models using the standard notation of the Systems Biology Graphical Notation (SBGN), and can embed such views within onés web pages as desired. Pathway views may be navigated using zoom and scroll tools; pathway object properties, including any external database references available in the data, may be inspected interactively. The automatic layout component of VISIBIOweb may also be accessed programmatically from other tools using Hypertext Transfer Protocol (HTTP). The web site is free and open to all users and there is no login requirement. It is available at: http://visibioweb.patika.org. © The Author(s) 2010. Published by Oxford University Press.
Open Access
Visualization of virtual architecture
(IEEE, 1997) Şenyapılı, Burcu
This study constitutes a framework, a justification and a proposal for the opportunity to improve the use and efficiency of visualization of architecture in the virtual environment. It seeks a new platform to define architectural design communication. The design process depends upon creation of models and virtual environment offers the medium of exchange where the design model can be shared and criticized by people other than the designer; various analysis can be applied and the results of both can be used to change or improve the design. Possibilities offered by visualization do not fit into the paper-based way of architectural thinking. In order to benefit from the potential of visualization it is required to redefine architecture, architectural design process and architectural terms with respect to the virtual environment. This study introduces a transitional solution between the paper-based and the future ways of thinking in architecture by enabling the designers customize the visualization software according to their purposes.