• Title/Summary/Keyword: System-level design

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A Study on the Optimal Design of JIT Kanban System under Uncertain Environment (불확실한 환경하에서의 JIT 간판 시스템 최적설계에 관한 연구)

  • 김용범;김우열
    • Journal of the military operations research society of Korea
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    • v.24 no.1
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    • pp.176-188
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    • 1998
  • In this paper, it is identified that the optimal level of each performance measures (service and inventory level) is not sensitive to an uncertain environment under JIT Kanban system designed by Moeeni. Moreover, it is proposed that the optimal design method considering multiple performance characteristics is the optimal level decision method according to the relative importance differences of each performance when there exist multiple performance characteristics. The result from the simulation analysis shows that the number of Kanban for stage 3 (final process) and stage 2 is increased at the service level. It is found that the expected loss is minimal when the cycle time decreases and the container size increases. However, the stage 1 is not affected by the number and cycle time of Kanban. It is thus important to consider carefully the cycle time and the container size of the Kanban to satisfy the demand in right time. In case of inventory level, the working inventory level decreases when the container size is decreased and the working inventory level also decreases slightly when the cycle time of the Kankban is increased in stage 1 and 2.

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RELIABILITY-BASED DESIGN OPTIMIZATION OF AN AUTOMOTIVE SUSPENSION SYSTEM FOR ENHANCING KINEMATIC AND COMPLIANCE CHARACTERISTICS

  • CHOI B.-L.;CHOI J.-H.;CHOI D.-H.
    • International Journal of Automotive Technology
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    • v.6 no.3
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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.

Knowledge Modeling of Reliability Analysis and Safety Design for Offshore Safety Instrument System with MBSE (Model-Based Systems Engineering) (모델기반 시스템엔지니어링을 활용한 해양플랜트 안전시스템(SIS, Safety Instrumented System)의 신뢰도 분석 및 안전설계 지식 모델링)

  • Bae, Jeong-hoon;Jung, Min-jae;Shin, Sung-chul
    • Journal of the Society of Naval Architects of Korea
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    • v.55 no.3
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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.

An Experimental Study on the Optimistic Recognition Level of Public Address System as a Soundscape Application Facility (사운드스케이프 적용을 위한 옥외 P.A. 시스템의 적정 인지레벨에 관한 실험적 연구)

  • Song, Min-Jeong;Jang, Gil-Soo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.11
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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.

VHDL Design of Hybrid Filter Bank for MPEG Audio Decoder and Verification using C-to-VHDL Interface (MPEG 오디오 복호기용 하이브리드 필터의 VHDL 설계 및 C 언어 인터페이스에 의한 기능 검증)

  • 국일호;박종진;박원태;조원경
    • Journal of the Institute of Electronics Engineers of Korea TE
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    • v.37 no.5
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    • pp.56-61
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    • 2000
  • Silicon semiconductor technology agrees that the number of transistors on a chip will keep growing exponentially, and it is pushing technology toward the System-On-Chip. In SoC Design, Specification at system level is key of success. Executable Specification reduces verification time. This Paper describes the design of IMDCT for MPEG Audio Decoder employing system-level design methodology and Executable Specification Methodology in the VHDL simulator with FLI environment.

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Performance based evaluation of RC coupled shear wall system with steel coupling beam

  • Bengar, Habib Akbarzadeh;Aski, Roja Mohammadalipour
    • Steel and Composite Structures
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    • v.20 no.2
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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.

THE EXTENSION OF THREE-WAY BALANCED MULTI-LEVEL ROTATION SAMPLING DESIGNS

  • Kim, K.W.;Park, Y.S.;Lee, D.H.
    • Journal of the Korean Statistical Society
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    • v.35 no.4
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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.

Design Recommendations of the Occupant Protection Systems Using Orthogonal Arrays (직교배열표를 이용한 승객보호장구의 설계)

  • 임재문;박경진
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.8
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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.

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An Analysis of the Partition Algorithm for Digital System Design (디지털 시스템 설계를 위한 분할 알고리즘의 분석)

  • 최정필;한강룡;황인재;송기용
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.69-72
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    • 2001
  • High-level synthesis generates a structural design that implements the given behavior and satisfies design constraints for area, performance, power consumption, packaging, testing and other criteria. Thus, high-level synthesis generates that register-transfer(RT) level structure from algorithm level description. High-level syntehsis consist of compiling, partitioning, scheduling This paper we study the partitioning process, and analysis the min-cut algorithm and simulated annealing algorithm.

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Research Case of Military Maintenance Depot Technology Level Diagnosis System Using Delphi Technique and CMMI (델파이 기법과 CMMI를 활용한 군 정비창 기술수준 진단체계 연구사례)

  • Jihoon Cho
    • Journal of Korean Society for Quality Management
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    • v.52 no.2
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    • pp.357-376
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    • 2024
  • Purpose: The purpose of this study is to design an objective and comparable diagnostic system for diagnosing the technology level of military maintenance depots and verify its actual applicability. Methods: Literature Review, Capability Maturity Model Integration, Analytic Hierarchy Process. Results: Military maintenance depot maintenance quality level diagnosis items, Maintenance quality level by maintenance technology area, Guidelines for diagnosing maintenance quality level, Quality level comparison results by area and implications for improvement. Conclusion: In order to systematically evaluate the maintenance quality of military maintenance depots, this study was conducted with the goal of designing an overall maintenance quality diagnosis system, including diagnosis areas, diagnosis items, and a diagnosis score award system, by improving the existing evaluation method. In addition, the newly developed maintenance quality diagnosis system was applied to actual evaluation activities and the results were returned to members, confirming the usefulness of the developed maintenance quality diagnosis system in the field.