Browsing by Subject "Computer Aided Design"

Now showing 1 - 7 of 7

Open Access
Comparative analysis on the cognition of designer's identity through digital presentation drawings
(2003) Akalın, Genco
In parallel to the developments in computer technology and the broad use of computers in the design domain, computer media presentations are widely used today in architecture. Architectural presentation drawings are means of externalization the internal world, thoughts and identity of architects. However, the issue of the cognition of designer’s identity in computer media presentations is rarely addressed in the researches as compared to studies on traditional media presentations. On the contrary, computers are mainly regarded as reflecting their own identity rather than providing designers potentials to express themselves and to achieve differences and variations. In this study, a comparative analysis of the cognition of designer’s identity in architectural presentation drawings is carried out. The analysis provided enough evidence that similar to architectural presentation drawings of traditional media, computer media presentations hold potentials for the reflection of designer’s identity
Open Access
A fast neural-network algorithm for VLSI cell placement
(Pergamon Press, 1998) Aykanat, Cevdet; Bultan, T.; Haritaoğlu, İ.
Cell placement is an important phase of current VLSI circuit design styles such as standard cell, gate array, and Field Programmable Gate Array (FPGA). Although nondeterministic algorithms such as Simulated Annealing (SA) were successful in solving this problem, they are known to be slow. In this paper, a neural network algorithm is proposed that produces solutions as good as SA in substantially less time. This algorithm is based on Mean Field Annealing (MFA) technique, which was successfully applied to various combinatorial optimization problems. A MFA formulation for the cell placement problem is derived which can easily be applied to all VLSI design styles. To demonstrate that the proposed algorithm is applicable in practice, a detailed formulation for the FPGA design style is derived, and the layouts of several benchmark circuits are generated. The performance of the proposed cell placement algorithm is evaluated in comparison with commercial automated circuit design software Xilinx Automatic Place and Route (APR) which uses SA technique. Performance evaluation is conducted using ACM/SIGDA Design Automation benchmark circuits. Experimental results indicate that the proposed MFA algorithm produces comparable results with APR. However, MFA is almost 20 times faster than APR on the average.Cell placement is an important phase of current VLSI circuit design styles such as standard cell, gate array, and Field Programmable Gate Array (FPGA). Although nondeterministic algorithms such as Simulated Annealing (SA) were successful in solving this problem, they are known to be slow. In this paper, a neural network algorithm is proposed that produces solutions as good as SA in substantially less time. This algorithm is based on Mean Field Annealing (MFA) technique, which was successfully applied to various combinatorial optimization problems. A MFA formulation for the cell placement problem is derived which can easily be applied to all VLSI design styles. To demonstrate that the proposed algorithm is applicable in practice, a detailed formulation for the FPGA design style is derived, and the layouts of several benchmark circuits are generated. The performance of the proposed cell placement algorithm is evaluated in comparison with commercial automated circuit design software Xilinx Automatic Place and Route (APR) which uses SA technique. Performance evaluation is conducted using ACM/SIGDA Design Automation benchmark circuits. Experimental results indicate that the proposed MFA algorithm produces comparable results with APR. However, MFA is almost 20 times faster than APR on the average.
Open Access
The (in)secure position of the design jury towards computer generated presentations
(Elsevier, 2005-05) Basa, I.; Senyapili, B.
The tendency towards computer aid in design presentations differs in academia than in the practicing field; practice seems to welcome computer aid in presentation, whereas in academia there seems to be a dilemma. In this study, we approach this duality based on our teaching experience within an interior architecture curriculum. First, we unfold the problematic to identify the contributing factors, then we observe the tendencies through a questionnaire with design students and interviews with design instructors, and finally we project upon our findings. We claim that the contributing factors to the problematic are: loss of author identity, problems of authenticity, and proficiency of the instructors in computers. Also we claim that although the transitional period of accommodating computer tools in design education in terms of presentation seems to be over, an adjustment period is starting anew. One of the powerful aspects of this period is not allowing hand skills to fade away.
Open Access
A photometric investigation of ultra-efficient LEDs with high color rendering index and high luminous efficacy employing nanocrystal quantum dot luminophores
(Optical Society of America, 2009-12-24) Erdem, T.; Nizamoglu, S.; Sun, X. W.; Demir, Hilmi Volkan
We report a photometric study of ultra-efficient light emitting diodes (LEDs) that exhibit superior color rendering index (CRI) and luminous efficacy of optical radiation (LER) using semiconductor quantum dot nanocrystal (NC) luminophores. Over 200 million systematically varied NC-LED designs have been simulated to understand feasible performance in terms of CRI vs. LER. We evaluated the effects of design parameters including peak emission wavelength, full-width-at-half-maximum, and relative amplitudes of each NC color component on LED performance. Warm-white LEDs with CRI >90 and LER >380 lm/W at a correlated color temperature of 3000 K are shown to be achieved using nanocrystal luminophores. (C) 2009 Optical Society of America
Open Access
A simulation program for efficient analysis of linear circuits
(1996) Sungur, Mustafa
circuit simulation program using generalized asymptotic waveform evaluation technique is introduced. The program analyzes circuits with lumped a.nd distributed components. It computes the moments ci.t a few Irecjuency points and extracts the coefficients of an approximating rational by employing one of t,he two different methods. One of the examined methods is proposed to compare the accuracy of results and the execution times with conventional simulators and sevei’cil examples are demonstrated, indicating that our sirnulcv tor provides a. speed improvement without a significant loss of accuracy.
Open Access
A spring force formulation for elastically deformable models
(Pergamon Press, 1997) Güdükbay, Uğur; Özgüç, B.; Tokad, Y.
Continuous deformable models are generally represented using a grid of control points. The elastic properties are then modeled using the interactions between these points. The formulations based on elasticity theory express these interactions using stiffness matrices. These matrices store the elastic properties of the models and they should be evolved in time according to changing elastic properties of the models. However, forming the stiffness matrices at any step of an animation is very difficult and sometimes the differential equations that should be solved to produce animation become ill-conditioned. Instead of modeling the elasticities using stiffness matrices, the interactions between model points could be expressed in terms of external spring forces. In this paper, a spring force formulation for animating elastically deformable models is presented. In this formulation, elastic properties of the materials are represented as external spring forces as opposed to forming complicated stiffness matrices. © 1997 Elsevier Science Ltd.
Open Access
Virtualization of design and production
(2006) Erdener, Başar
This study aims to make an analysis on the meaning of products with regards to recent developments in design and production technologies. The notions of the use, exchange and sign values of products are aimed to be questioned and explored through relevant instances within the consumption logic. Mass customization, as an outcome of recent advances in technology is argued through its effects on the meaning and presentations of products within the market. It is also discussed in this thesis how the computer aided design and manufacturing affects the mode of production and how this reflects on the representations of products that we encounter.