• International Journal of Automotive Technology
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• 제6권3호
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• pp.235-242
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• 2005

This study introduces the Reliability-Based Design Optimization (RBDO) to enhance the kinematic and compliance (K & C) characteristics of automotive suspension system. In previous studies, the deterministic optimization has been performed to enhance the K & C characteristics. Unfortunately, uncertainties in the real world have not been considered in the deterministic optimization. In the design of suspension system, design variables with the uncertainties, such as the bushing stiffness, have a great influence on the variation of the suspension performances. There is a need to quantify these uncertainties and to apply the RBDO to obtain the design, satisfying the target reliability level. In this research, design variables including uncertainties are dealt as random variables and reliability of the suspension performances, which are related the K & C characteristics, are quantified and the RBDO is performed. The RBD-optimum is compared with the deterministic optimum to verify the enhancement in reliability. Thus, the reliability of the suspension performances is estimated and the RBD-optimum, satisfying the target reliability level, is determined.

• 대한조선학회논문집
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• 제55권3호
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• pp.222-235
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• 2018

The hydrocarbon gas leak in the offshore plant can cause large accidents and lead to significant damages to human, property and environment. For prevention of fire or explosion accidents from gas leak, a SIS(Safety Instrumented System) should be installed. In the early stage of the offshore design, required SIL(Safety Integrated Level) is determined and reliability analysis is performed to verify the design in reliability aspects. This study collected data, information related to reliability analysis and created knowledge model of safety design for the offshore system with MBSE(Model-Based Systems Engineering) concept. Knowledge model could support safety engineer's design tasks as the guidance of reliability analysis procedure of safety design and make good conversation with other engineers in yard, class, company, etc.

• 한국소음진동공학회논문집
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• 제17권11호
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• pp.1050-1055
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• 2007

P.A.(public address) system is considered as an useful active soundscape appliance which can gives a place identity and vitality by introducing conventional musics, environmental musics, bird singing sounds etc. In this study, the main aim is to know the optimistic distance from the speaker and sound pressure level range of introducing sound. So, the sound pressure level of P.A. system due to distances were measured and subjects' responses with level variations were checked. The main results are as follows. Level range from 64 dB to 71 dB is comfortable for subjects. And the optimal level of introducing sound is related with sound source characteristics. The results of this study could be used for street furniture location design and P.A. system output level.

• Journal of the Korean Statistical Society
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• 제35권4호
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• pp.343-353
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• 2006

The two-way balanced one-level rotation design, $r_1^m-r_2^{m-1}$, and the three-way balanced multi-level rotation design, $r_1^m(\iota)-r_1^{m-1}$, were discussed (Park et al., 2001, 2003). Although these rotation designs enjoy balancing properties, they have a restriction of $r_2=c{\cdot}r_1$ (c should be a integer value) which interferes with applying these designs freely to various situations. To overcome this difficulty, we extend the $r_1^m(\iota)-r_1^{m-1}$ design to new one under the most general rotation system. The new multi-level rotation design also satisfies tree-way balancing which is done on interview time, rotation group and recall time. We present the rule and rotation algorithm which guarantee the three-way balancing. In particular, we specify the necessary condition for the extended three-way balanced multi-level rotation sampling design.

• 대한전자공학회논문지TE
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• 제37권5호
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• pp.56-61
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• 2000

반도체 공정 기술의 발달은 기하 급수적인 집적도의 증가를 가져오고, 이는 한 칩에 시스템을 모두 집적시키는 시스템 온 칩(SoC : System on Chip) 설계가 가능해지고, 이에 따른 설계 방법의 변화를 요구하고 있다. Soc 설계는 시스템에서 설계 사양(Specification)의 정의가 중요한 요소가 되고 있다. 본 논문에서는 MPEG 오디오 복호기에서 사용되는 IMDCT를 시스템 수준의 실행 가능한 설계 사양(Executable Specification)에 의해 설계하였다.

• Steel and Composite Structures
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• 제20권2호
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• pp.337-355
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• 2016

Steel coupling beam in reinforced concrete (RC) coupled shear wall system is a proper substitute for deep concrete coupling beam. Previous studies have shown that RC coupled walls with steel or concrete coupling beam designed with strength-based design approach, may not guarantee a ductile behavior of a coupled shear wall system. Therefore, seismic performance evaluation of RC coupled shear wall with steel or concrete coupling beam designed based on a strength-based design approach is essential. In this paper first, buildings with 7, 14 and 21 stories containing RC coupled shear wall system with concrete and steel coupling beams were designed with strength-based design approach, then performance level of these buildings were evaluated under two spectrum; Design Basis Earthquake (DBE) and Maximum Considered Earthquake (MCE). The performance level of LS and CP of all buildings were satisfied under DBE and MCE respectively. In spite of the steel coupling beam, concrete coupling beam in RC coupled shear wall acts like a fuse under strong ground motion.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.208-215
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• 1999

Using the orthogonal arrays and the occupant analysis software based on the multi-body dynamics , two interactive design algorithms are proposed to improve the initial design of the occupant protection systems. Algorithm 1 sequentially moves the narrow design space within the upper and the lower design limit. Algorithm 2 sequentially reduces the relatively wide design space. Each design algorithm is composed of two levels . The first level is to improve the characteristics of the crash performance considering the noise factors. In order to obtain the robust design, the second level reduces the variations the noise factors. In order to obtain the robust design, the second level reduces the variations due to the tolerance of the design variable. To utilize the algorithm 1, HIC(Head Injury Criterion) , 3 msec criterion value of the chest acceleration and the femur load decreased by 27.4%, 10.4% and 55.8%, respectively. To utilizer the algorithm 2 , the results decreased by 38.0%, 10.5% and 3.0% , respectively.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2001년도 하계 학술대회 논문집(KISPS SUMMER CONFERENCE 2001
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• pp.69-72
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• 2001

High-level synthesis는 주어진 동작과 면적, 성능, 전력 소모, 패키징, 테스팅 등의 주어진 제한을 만족하게 구현된 구조적 디자인을 생성한다. 즉 high-level syntehesis란 디지털 시스템의 알고리즘 레벨 서술로부터 레지스터 전달구조의 구현에 이르는 과정을 의미한다. 이러한 high-level synthesis의 과정은 컴파일, 분할, 스케줄링 등의 단계를 거쳐 디지털 시스템을 설계할 수 있다. 본 논문에서는 high-level synthesis의 단계중 분할 과정을 연구하고, 분할 알고리즘 중에서 min-cut 알고리즘과 simulated annealing 알고리즘을 사용하여 비교 분석하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1681-1684
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• 2003

We propose the intelligent tutoring system for the mobile english learning. The proposed system is based on the item response theory to analyze the level of learner. We define the types of item, teaching method and item disposition according to contents modeling. The system estimates the learner level and it gives the learning contents, the evaluation results, and feedback. The system gives those by inference engine which consists of learner's level estimation value, method diagnostic value and disposition diagnostic value.

• 대한전자공학회논문지
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• 제10권5호
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• pp.1-6
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• 1973

본논문은 자동급수기의 설계 및 제작연구를 한 것으로 digital scanning circuits를 이용하여 10개의 probe를 차례로 scanning하여 지표의 습도를 검출하여 reference level과 비교하여 필요한곳에 자동적으로 급수하도록 설계하였다. 이 system의 control을 위하여 main clock oscillator와 controloscillator를 사용하였고 control circuit로는 programmable unijunction transistor를 이용하여 reference level을 조절하게하여 임의의 원하는 습도에 급수하도록 하였다. 제작된 급수재는 모래의 습도가 6%에서 51%로 변화시키면서 실험하여 언제나 input level이 reference level보다 약 0.6V보다 높을때 완전동작하였으며 reference level은 임의로 조절할 수 있었다.