• Journal of the Korean Magnetics Society
• /
• v.23 no.2
• /
• pp.62-67
• /
• 2013

This paper introduces an effective methodology for reliability-based design optimization of electromagnetic products, where a performance measure approach is adopted to accurately assess probabilistic constrains. Two design problems consisting of a loudspeaker and a superconducting magnetic energy storage system are considered. The efficiency of the proposed method in evaluating the failure probability of performances during the optimization process are compared with the existing method based on the reliability index approach. Moreover, in term of the accuracy of probability failure values, optimized design results are examined with reference values obtained from the Monte Carlo simulation.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2011.04a
• /
• pp.1302-1305
• /
• 2011

스마트폰에서 낸드 플래시 메모리가 저장 장치로 사용됨에 따라 다양한 플래시 파일 시스템과 플래시 변환 계층들이 제시되었다. 플래시 메모리는 덮어 쓰기가 불가능하기 때문에 이들 기법들은 기본적으로 로그 기반 구조를 취하고 있지만 가비지 수집, 데이터 배치 정책의 설계에 따라 성능과 수명 관리 측면에서 많은 차이를 보인다. 본 논문은 플래시 메모리 관리 기법들의 다양한 설계가 성능에 미치는 영향을 알아보고 종합적으로 비교 해보기 위해 대표적인 스마트폰 플랫폼인 안드로이드상에서 시뮬레이션 기반의 성능 평가를 수행 한다. 또한 각 기법들의 설계가 성능에 미치는 영향을 분석 한다.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.30 no.4
• /
• pp.351-361
• /
• 2017

Reinforced concrete(RC) structural walls are major lateral load-resisting structural member in building structures. Generally these RC structural walls are coupled with each other by the coupling beams and slabs, and therefore they behave as RC coupled structural wall system. In the design of these coupled structural wall systems, member forces are calculated using elastic structural analysis. These elastic analysis methodologies for the design of coupled structural wall system was not reasonable because it can not consider their ultimate behavior and assure economic feasibility. Performance based design and moment redistribution method to solve these problems is regarded as a reasonable alternative design method for RC coupled structural wall system. However, it is not verified under various design parameters. In this study, nonlinear analysis of RC coupled structural wall system was performed according to various design parameters such as reinforcement ratio, ultimate concrete strain and wall height. Based on analysis results, design considerations for coupled RC structural wall system was proposed.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.15 no.4
• /
• pp.415-429
• /
• 2013

Performance-based design is becoming a key word for structure design in architectural and civil engineering spheres. In this paper, the need of the performance-based design, especially for tunnels, was enhanced by case study on the largely deformed cut-and-cover arch tunnel built by the prescribed design. In addition, this paper introduces effective method of subdivision on tunnel performance to help field engineer's comprehension. Case study dealing with the issue of typical backwards problem in geotechnical engineering was examined. First of all, the outline of the damaged culvert as well as the surrounding embankment is in detail described. The background, together with the cause of damage, is discussed based on the results of site investigation. Secondly, it was attempted to elucidate the deformation mechanism of the embankment by means of numerical analysis, and the countermeasures are proposed. Finally, the stability of the embankment with the countermeasures was evaluated.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.6A
• /
• pp.561-572
• /
• 2010

This paper is a study about application of recently proposed Performance Based Mixture Design (PBMD) for design of high strength concrete (HSC) to obtain HSC mix proportion that satisfies required performances. The PBMD method which uses Satisfaction curve based on a Bayesian method is a performance oriented concrete mix proportion design procedure easily applicable to any condition and environment for a possible replacement to the current prescriptive design standards. Based on extensive experimental results obtained for various materials and performance parameters of HSC, the application feasibility of the developed PBMD procedure for HSC has been verified. Also, the proposed PBMD procedure has been used to perform application examples to obtain desired target performances of HSC with optimum concrete mixture proportions using locally available materials, local environmental conditions, and available concrete production technologies. The validity and precision of HSC mix proportion design obtained using the PBMD method is verified with the experimental and ACI presented results to check the feasibility for actual design usage.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.461-462
• /
• 2009

Since the modal pushover analysis (MPA) is introduced by A.K.Chopra in 2002, it has been the leading procedure for the seismic evalution of structures. However it has scarcely used on bridge structures dueing to its inherent limitation. In this paper, MPA is applied on cable-stayed bridges to check its applicability on such structures.

• Journal of the Korea Society for Simulation
• /
• v.18 no.1
• /
• pp.17-25
• /
• 2009

This paper suggests fuzzy-based Segment-Boost method and an effective method for face recognition using the fuzzy-based Segment-Boost. Fuzzy-based Segment-Boost eliminates the limitations of Segment-Boost, and it guarantees improved learning performance and the stability of the performance. By using the fuzzy theory, fuzzy-based Segment-Boost optimizes the selection number of sub-vectors, and leads the optimized learning performance. The fuzzy controller designed in this paper measures learning performance of the fuzzy-based Segment-Boost, and it controls the selection number of sub-vectors by inferring the optimized selection number. The simulation results show that the fuzzy controller inferred the selection number which is very approximate to the true optimized value. As a result, fuzzy-based Segment-Boost showed higher face recognition rate than compared boosting methods and it preserves the velocity of feature selection as fast as that of Segment-Boost. From the experimental results, it was proved that fuzzy-based Segment-Boost has improved and stable performances of learning, feature selection and face recognition.

• Journal of the Korean Society for information Management
• /
• v.24 no.3
• /
• pp.343-362
• /
• 2007

The purpose of this study is to design and implement an ontology-based retrieval system for the electronic records of universities and to compare its performance with the existing keyword-based retrieval system. We used OntoStudio 1.4 for implementing an ontology-based retrieval system, and the test collection consisted of the following: (1) 5,099 electronic records of the 'personnel management notification' created by Korea Maritime University, (2) 20 topics (10 short-topics and 10 long-topics), and (3) the relevant assessments were conducted by the group of human experts. 10 university staff participated in the experiment of keyword-based searching and used the same test collection as used in the experiment of ontology-based searching. The ontology-based retrieval system outperformed to the keyword-based retrieval system in terms of Recall and Precision, and the same results showed in the test of the short-topics and long-topics comparison.

• Journal of KIISE:Computing Practices and Letters
• /
• v.5 no.2
• /
• pp.236-246
• /
• 1999

최근 운영체제 개발분야에서 마이크로커널 설계 기술이 새로운 경향으로 부각되고 있다. 마이크로커널은 기존의 모노리딕 커널과 상이한 구조를 가지고 있으므로, 성능분석 튜닝을 위하여 새로운 도구를 필요로 한다. 본 논문에서는 마이크로커널 기반 운영체제를 위한 성능 측정도구 MKperf의 개발에 관하여 기술하고자 한다. MLperf 는 마이크로커널 r조의 성능에 중요한 영향을 미치는 문맥 교환과 원격 프로시저 호출을 추적할수 있다. 뿐만 아니라 , 캐시와 TLB와 같이 메모리 성능에 결정적인 영향을 미치는 다양한 하드웨어 성능요소들을 측정할수 있다. MDperf 의 이러한 측정 기능은 마이크로커널 기반 운영체제 성능을 정량적으로 분석하는데에 유용하게 사용될 수있다.

• Journal of the Korea Concrete Institute
• /
• v.25 no.5
• /
• pp.509-516
• /
• 2013

In this paper, performance based design of coupling beam using non-linear static analysis is proposed considering probability distribution of flexural and shear strength in order to develop flexural hinge. This method considers post-yielding behavior of coupling beam and stress redistribution of system. It can verify the reduced effective stiffness to meet the current design requirement based on linear analysis. It also evaluates the lateral displacement under service load (un-factored wind load) properly. In addition, it can optimize the coupled shear wall system by taking stress redistribution between members into account. For a simplified 30-story building, non-linear static (push-over) analysis was performed and the structural behavior was checked at performance point and several displacement steps. Furthermore, system behavior according to the amount of reinforcement and depth of coupling beam was explored and compared each other.