• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.141-154
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• 1987

The algorithm proposed utilizes the tow-levels technique. In the first level which consists of teeatment only the applied load and design stress as the random variables whose parent distribution has the normal distribution, the cross-sectional areas of the truss members such that the their probabilities of failure have the preseribed failure probabilites are optimized by transforming the nonlinear problem into SUMT, and solving it utilizing modified Newton-Raphson method. In the second level, the geometric shape of truss structure is optimized by utilizing the unidirectional search technique of Powell method which makes it possible to minimize only the objective function. The algorithm proposed is numerically tested for the several truss structures with various shapes and loading conditions. The numerical analysis shows that the rate of decreasing the weight of truss structures is dependent on the prescribed failure probability of the each member of truss structure and the covariance of the applied load and design stress.

• Bulletin of the Society of Naval Architects of Korea
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• v.18 no.2
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• pp.21-34
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• 1981

조선공업(造船工業)의 생산관리(生産管理)(planning & production control)에서는 과거의 실적을 참고로 한 예정공수를 그대로 공사량(工事量)으로 간주한 지금까지의 사고방법을 고쳐서 용접장(溶接長) 및 취부장(取付長)등의 생산량(生産量)을 누계곡선(累計曲線)으로 표시하여 공사(工事)의 진척상황을 파악하고, 또 이들의 생산량(生産量)을 기초로 한 공수누계곡선(累計曲線)에 의해서 생산능률을 파악하고 순서(順序)(sequence)를 중(重)히 여겨야 한다. 이와 더불어 조선공업에도 computer가 일반적(一般的)으로 보급됨에 따라 현금까지 기술계산(技術計算)에 주(主)로 사용(使用)하여 오던 것을 계획관리(計劃管理)의 이론적(理論的)인 수단(手段)으로 활용(活用)될 수 있다. 즉(卽), 일수(日數)에 따라 변화(變化)하는 동적(動的)이며 확률변수(確率變數)를 포함하지 않은 확정적(確定的)인 최적공정(最適工程)과 최적 실천을 계획(計劃)하며 또한 모든 관계자가 협동(協同)하는 신속한 계획관리(計劃管理)의 매체 system으로써 사용(使用)하여야 한다. 따라서 모든 것이 simulation된 생산관리(生産管理) 사항(事項)을 단지 목적지를 표시하고 길은 임의(任意)로 선택시키는 것이 아니고 목적지(目的地)에 이르는 길을 명확(明確)하게 지정(指定)한 계획지시(計劃指示)가 명령(命令)으로써 현업(現業)이 따르게 하려 함에 목적(目的)을 두고 본 프로젝트를 개발 정착시켰다. 세계제일의 조선국으로 우리나라 조선공업 발전에 기여하고자 본문을 계속 조선학회지에 게재하고자 한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.4
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• pp.53-60
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• 1986

This study is directed to propose a probability based LRFD design code, which could possibly replace the traditional USD provisions of the current code, based on the AFOSM reliability theory. The uncertainties of resistances and load effects for each R.C. structural elements are evaluated and adopted considering our practice, and a set of rational target reliability indices are selected based on the calibration with the reliability of the current R.C. design code and by considering the desired hierarchy of safety level. Then, a set of common load factors are chosen from the results of load and resistance factors which are computed by AFOSM method using the Rackwitz-Fiessler's efficient practical algorithm which is to transform the non-normal variables into the equivalent normal variables. It may be asserted that the proposed LRFD code for the R.C. building structures may have to be incorporated into the current RC. design codes as a design provision corresponding to the USD provisions of the current R.C. design code.