• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.1221-1224
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• 2003

A 64-point R2$^2$ SDF pipeline FFT processor using a new efficient computation sharing multiplier was designed. Computation sharing multiplication specifically targets computation re-use in multiplication of coefficient vector by scalar and is effectively used in DSP(Digital Signal Processing). To reduce the number of multipliers in FFT, we used the proposed computation sharing multiplier. The 64-point pipeline FFT processor was implemented by VHDL and synthesized using Max+PLUSII of Altera. The simulation result shows that the proposed computation sharing multiplier can be reduced to about 17.8% logic cells compared with a conventional multiplier. This processor can operate at 33MHz and calculate a 64-point pipeline FFT in 1.94 $mutextrm{s}$.

• 정보보호학회논문지
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• 제11권1호
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• pp.64-72
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• 2001

본 논문은 IDEA 알고리즘을 사용한 고속 암호 IC의 설계에 관한 것이다. IDEA 알고리즘을 회로로 구현하기 위하여 전체 회로를 6개의 주요 기능블럭으로 분할하여 설계하였다. 주요 블록으로 암호키 및 복호키 생성부, 입력 데이터 처리부, 암호화 처리부, 출력 데이터 처리부, 그리고 동작모드 제어부 등이 있나. 서브키 생성회로는 연간속도보다 회로면적을 축소시키는 방향으로 설계한 반면, 암호화 처리부는 회로면적보다 연산속도를 증가시키는 방향으로 설계목표를 정했다. 따라서 반복연산에 적합한 파이프라인 구조와 연간속도를 향상시키는 모듈라 승산기를 채택하였다. 특히, 많은 연산시간이 소요되는 모듈라 승산기는 연산속도를 증가시키기 위하여 캐리선택 가산기 및 modified Booth 승 산 알고리즘을 사용하여 한 클럭에 동작하도록 설계하였다. 또한, 입력 데이터 처리부는 데이터를 동작모드에 따라 8-bit, 167-bit 32-bit 단위로 받아들이기 위하여 데이터 버퍼가 8-bit, 16-bit, 32-bit 씩 이동할 수 있도록 하였다. 0.25$\mu\textrm{m}$ 공장기술을 사용하여 시뮬레이션한 결과, 이 IC는 큰 면적을 요구하지 않으면서도 1Gbps 이상의 throughput을 달성하였으며, 회로구현에 약 12,000gates가 소요되었다.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2162-2173
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• 2021

In this paper, the coupling of fine-mesh computational fluid dynamics (CFD) thermal-hydraulics (TH) code and neutronics code is achieved using the Ansys Fluent User Defined Function (UDF) for code development, including parallel meshing mapping, data computation, and data transfer. Also, some CFD schemes are designed for mesh mapping and data transfer to guarantee physical conservation in the coupling computation. Because there is no rigorous research that gives robust guidance on the various CFD schemes that must be obtained before the fine-mesh coupling computation, this work presents a quantitative analysis of the CFD meshing and mapping schemes to improve the accuracy of the value and location of key physical prediction. Furthermore, the effect of the sub-pin scale coupling computation is also studied. It is observed that even the pin-resolved coupling computation can also create a large deviation in the maximum value and spatial locations, which also proves the significance of the research on mesh mapping and data transfer for CFD code in a coupling computation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.989-990
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• 2006

This paper presents a design of 3D Graphics Geometry processor. A geometry processor needs to cope with a large amount of computation and consists of transformation processor and lighting processor. To deal with the huge computation, a vector processing structure based on pipeline chaining is proposed. The proposed geometry processor performs 4.3M vertices/sec at 100MHz using 11 floating-point units.

• 한국자동차공학회논문집
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• 제4권6호
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• pp.247-259
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• 1996

Kinematic design sensitivity analysis for vehicle in suspension systems design is performed. Suspension systems are modeled using composite joins to reduce the number of the constraint equations. This allows a semi-analytical approach that is computerized symbolic manipulation before numerical computations and that may compensate for their drawbacks. All the constraint equations including design variables are derived in symbolic equations for sensitivity analysis. By directly differentiating the equations with respect to design variables, sensitivity equations are obtained. Since the proposed method only requires the hard point data, sensitivity analysis is possible in suspension design stage.

• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1549-1557
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• 2018

Optimizing the design of large-scale electric machines based on nonlinear finite element analysis (FEA) requires longer computation time than other applications of FEA, mainly due to the huge size of the machines. This paper addresses a new region decision method (RDM) with mesh adaptive direct search (MADS) for the optimal design of wind generators in order to reduce the computation time. The validity of the proposed algorithm is evaluated using Rastrigin and Goldstein-Price benchmark function. Moreover, the algorithm is employed for the optimal design of a 5.6MW interior permanent magnet synchronous generator to minimize the torque ripple. Additionally, mechanical stress analysis as well as electromagnetic field analysis have been implemented to prevent breakdown caused by large centrifugal forces of the modified design.

• Computers and Concrete
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• 제6권6호
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• pp.505-521
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• 2009

The analysis of prismatic members made of reinforced concrete under inclined bending, especially the computation of ultimate loads, is a pronounced non-linear problem which is frequently solved by discretizing the stress distribution in the cross-section using interpolation functions. In the approach described in the present contribution the exact analytical stress distribution is used instead. The obtained expressions are integrated by means of a symbolic manipulation package and automatically converted to optimized Fortran code. The direct problem-computation of ultimate internal forces given the position of the neutral axis-is first described. Subsequently, two kinds of inverse problem are treated: the computation of rupture envelops and the dimensioning of reinforcement, given design internal forces. An iterative Newton-Raphson procedure is used. Examples are presented.

• International Journal of Naval Architecture and Ocean Engineering
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• 제2권4호
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• pp.177-184
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• 2010

In this study, geometric modeling techniques and their application to ship modeling and design are presented. Traditionally the hull shape is defined by using curves called the lines and various necessary computations are performed based on the discrete points obtained from the lines. However, some applications find difficulty in using the lines such as seakeeping analysis, which requires the computation of wetted part that is changing dynamically over time. To overcome such a problem and increase accuracy and efficiency in computation, two essential geometric modeling techniques, surface modeling and surface-to-surface intersection, are introduced and their application to ship modeling and analysis including hydrostatic computation, slamming and seakeeping analyses is presented.

• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.395-402
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• 2005

This paper deals with modeling and computer simulation of a full multibody vehicle model for a driving simulator. The multibody vehicle model is based on the recursive formulation and a corresponding simulation code is generated automatically from AUTOCODE, which is a symbolic computation package developed by the authors using MAPLE. The paper describes a procedure for automatically generating a highly efficient simulation code for the full vehicle model, while incorporating realistically modeled components. The following issues have been accounted for in the procedure, including software design for representing a mechanical system in symbolic form as a set of computer data objects, a multibody formulation for systems with various types of connections between bodies, automatic manipulation of symbolic expressions in the multibody formulation, interface design for allowing users to describe unconventional force-and torque-producing components, and a method for accommodating external computer subroutines that may have already been developed. The effectiveness and efficiency of the proposed method have been demonstrated by the simulation code developed and implemented for driving simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.666-668
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• 1998

In this paper we illustrate the design of a node label data flow machine based on self-timed paradigm. Data flow machines differ from most other parallel architectures, they are based on the concept of the data-driven computation model instead of the program store computation model. Since the data-driven computation model provides the excution of instructions asynchronously, it is natural to implement a data flow machine using self timed circuits.