• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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• pp.276-283
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• 2001

Performance-based design concepts require the next generation of codes. To implement the main concepts several design methodologies have been proposed. This paper reviews the framework of Korea Seismic Code and shows necessary modification for adoption of appropriate design methods. The selection of design earthquake levels with the introduction of risk factor is discussed for proper risk levels for all earthquake hazards. Displacement-based design, energy-based design, comprehensive design, and force-strength design methods are reviewed as one of possible next generation design methods. This paper proposes the direction of reconstruction for design earthquake levels with performance matrix, introduction of new design methods, and emphasis on non- structural components.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제13권4호
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• pp.231-239
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• 2007

본 논문에서는 국내 표준 128비트 블록 암호화 알고리즘인 SEED를 하드웨어로 설계할 경우 면적-성능간의 trade-off 관계를 보여준다. 본 논문에서 다음 4가지 유형의 설계 구조를 비교한다. (1) Design 1 : 16 라운드 완전 파이프라인 방식, (2) Design 2 : 단일 라운드의 반복 사용 방식 (3) Design 3 : G 함수 공유 및 반복 사용 방식 (4) Design 4 : 단일 라운드 내부 파이프라인 방식. (1),(2),(3)의 방식은 기존의 논문들에서 제안한 각기 다른 설계 방식이며 (4)번 설계 방식이 본 논문에서 새롭게 제안한 설계 방식이다. 본 논문에서 새롭게 제안한 방식은, F 함수 내의 G 함수들을 파이프라인 방식으로 연결하여 면적 요구량을 (2)번에 비해서 늘이지 않으면서도 파이프라인과 공유블록 사용의 효과로 성능을 Design 2와 Design 3보다 높인 설계 방식이다. 본 논문에서 4가지 각기 다른 방식을 각각 실제 하드웨어로 설계하고 FPGA로 구현하여 성능 및 면적 요구량을 비교 분석한다. 실험 분석 결과, 본 논문에서 새로 제안한 F 함수 내부 3단 파이프라인 방식이 Design 1 방식을 제외하고 가장 throughput 이 높다. 제안된 Design 4 가 단위 면적당 출력성능(throughput)면에서 다른 모든 설계 방식에 비해서 최대 2.8배 우수하다. 따라서, 새로이 제안된 SEED 설계가 기존의 설계 방식들에 비해서 면적대비 성능이 가장 효율적이라고 할 수 있다.

• 대한기계학회논문집B
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• 제30권1호
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• pp.16-23
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• 2006

The present study aims at establishing the design procedure of regenerative pumps. It is based on the new momentum exchange theory proposed in Yoo, Park and Chung. Salient feature of the present design procedure is that it does not require input of any kinds of empirical design data. Using the design procedure, a prototype regenerative pump has been designed and manufactured to confirm its validity. Comparison between the predicted performance and the experimental measurement reveals that the prototype pump has its maximum efficiency at the design flow rate and that the proposed performance analysis method satisfactorily predicts the machine performance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.967-972
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• 2001

An axial fan design code, called iDesignFan$^{TM}$, was developed. In this code, three major loss models were used to predicted the aerodynamic performance of a fan. The overall sound pressure level, predicted from steady blade loading, is also used as an input parameter from the third loop of the designing process to acquire most silent fan for the given aerodynamic performance parameters. With this kind of inverse design concept used in this code, the period of designing a fan, which has given aerodynamic performance with minimal acoustic noise, is significantly shortened. The experimental results of a prototype fan, designed by this code, showed that aerodynamic and acoustic performance of an axial fan is reasonably well predicted. Thus, one can design/develop an axial fan in a short time by using the code.e.

• 대한기계학회논문집
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• 제17권7호
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• pp.1851-1863
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• 1993

A procedure for the prediction of the off-design performance of a gas turbine engine is proposed. The system performance at off-design speed is predicted by coupling the thermodynamic models of a compressor and a turbine. The off-design performance of a compressor is obtained using the stage-stackimg method, while the Ainlay-Mathieson method is used for a turbine. The procedure is applied to a single-shaft gas turbine and its predictability is found satisfactory. The results also show that the net work output increases with the increase of the turbine inlet temperature, while the thermal efficiency is marginal. The maximum thermal efficiency at design point is obtained between the highest pressure ratio and design pressure ratio.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권2호
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• pp.85-91
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• 2002

A novel multi-section power divider configuration is Proposed to obtain wide-band frequency performance up to microwave frequency region. Design procedures for the proposed microwave broadband power divider are composed of a Planar multi-section three-Ports hybrid and a waveguide transformer design procedures. The multi∼section power divider is based on design theory of the optimum quarter- wave transformer Furthermore, in order to obtain the broadband isolation performance between the two adjacent output ports, the odd mode equivalent circuit should be matched by using the lossy element such as resistor. The derived design formula for calculating these odd mode∼matching elements is based on the singly terminated filter design theory. The waveguide transformer section is designed to suppress the propagation of the higher order modes such as waveguide modes due to employing the metallic electric wall. Simulation and experiment show excellent performance of multi section power divider.

• International Journal of Air-Conditioning and Refrigeration
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• 제11권1호
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• pp.17-23
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• 2003

A design procedure for cooling towers was set up using the Merkel theory In the past, the design data could be different depending on the characteristic curve that the engineer adopted. Therefore, consistent and reasonable criteria are required, which are based on the exact information of the cooling tower performance. In this study, analysis program for both the design and off-design for a counterflow-type cooling tower was developed and verified by comparing with experimental data. The off-design performance with various operating conditions was analyzed, as well.

• 대한기계학회논문집A
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• 제21권3호
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• pp.369-377
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• 1997

The torque converter, a major part of automatic transmissions, has many difficulties in analysis due to the factors such as power transmission through fluid flow, complex internal geometry, and various operating conditions. Because of such difficulties, the dynamic analysis and design of a torque converter are generally carried out by using equivalent performance model which is based on the concept of mean flow path. Since the design procedures of a torque converter are essential technology of automotive industry, the details of the procedures are rarely published. In this study, the basic design procedures of a torque converter are systemized and coded based on the equivalent performance model. The mathematical methods to deal with mean flow path determination and the core-shape are developed. And by using this model, the method of determination of performance parameters satisfying the requested performance is proposed. Finally, to embody the three-dimensional shape, the intermediate blade angles which maximize the tractive performance are determined and laid out.

• 한국수학교육학회지시리즈A:수학교육
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• 제55권1호
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• pp.107-127
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• 2016

The purpose of this study was to explore the possibility of mathematical instruction through performance task activities based on the The Backward Design, which was suggested at first by Wiggins & McTighe in 1998. The Design deals with a performance assessment task involving the whole objective and its entire content of a lesson. Based on the Backward Design, this study established the mathematical instructional materials, which deal with the concept of 'the sector' taught in middle school, with one large performance task including three small tasks. It is important that in the lesson students be guided to achieve the several learning goals by themselves through reasoning activities. For this purpose, a formal interview was carried out by the subject of three middle school mathematics teachers. As a result, in order to implement the instruction utilizing the performance tasks more efficiently in future, it is required that a large performance task should be selected or developed including the content or problem contexts to be relevant with the real-life challenging situations. In addition, to make students enhance reasoning skills, it is strongly requested that the tasks including the utilization of supplementary materials such as technological devices or manipulatives be dealt with in a lesson.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.125-128
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• 2008

오늘날 많은 연구기관에서 구조물 설계에 관한 연구가 수행되고 있는 가운데 내진분야에서 처음으로 구조물에 대한 성능기반설계에 대한 기본개념이 제시되었다. 이후 여러 연구기관에서 성능기반설계를 수행하기 위해 사용자와 설계자 간의 의사소통을 원활히 이루어지게 하기 위해 요구성능에 대한 기준을 정립를 하였다. 성능기반설계는 구조물이 위치하게 될 지역적 특성이나 구조물의 특성에 따라 구조물에 발생될 수 있는 위험에 대한 정확한 분석과 구조물에 대한 사회적 경제적 환경적 영향에 대한 분석을 통하여 구조물에 요구되는 요구성능에 맞추어 구조물을 설계하여 공용기간동안 구조물에 대한 안전을 보장하는 설계방법이다. 구조물에 대한 정확한 요구성능을 파악하기 위해 성능수준 및 성능목표에 대한 정의가 필요하여 본 연구에서 성능기반설계를 수행하기 위해 ATC-40(2002), FEMA-273(1997), Eurocode(1998)에서의 요구성능기준에 관한 기초자료를 조사하였다.