• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.48.1-48.1
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• 2011

In this presentation, We monitored weather data, such as global irradiance, ambient temperature, temperature of PV module, relative humidity and windspeed for 2 years, for determining accelerated test condition. then, we determined the temperature limit of accelerated test through weather data and FEM analysis. Detailed procedures will be summarized in this work. After analysing outdoor stress such as thermal stress, we decided main failure modes and mechanisms of PV module, especially solder joint of ribbon wire. we carried out the measurement of material properties such as thermal expansion coefficient for planning of accelerated test. we designed accelerated test based on FEM analysis results. we carried out thermal cycling test with 1 cell mini module for 3 months. We monitored the change of electrical performance every 1 week such as Voc, Isc, Pmax, etc. and then, we analized the ribbon wire/electrode intefaces. Detailed results will be summarized in this work.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1508-1513
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• 2006

Currently, the Korean railway safety law (RSL) and its ordinances have been enforced for the guarantee of the safety of railway. In RSL, the quality certification is required to guarantee the safety and performance of railway components or systems. However, not much attention has been focused on the quality certification scheme for railway components or systems since the scheme is relatively new. Therefore, in this investigation, the detailed guidelines and main contents for the enforcement of quality certification for railway components will be suggested, and the detailed items including the procedures, subjects, management, etc., will be addressed. Moreover, a better understanding on quality certification for railway components will be provided.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.659-664
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• 2008

The Railroad Safety Act's regulation reads as follows. "The Minister of Construction and Transportation may qualify and authorize the product to guarantee performance and safety of parts, machine, and device used in Railway fields." Another regulation reads as follows."“The guidelines about targets, standards, and procedures of Quality and Authority in first provision are decided as Ministry of Construction and Transportation Decree." The software used in rail cars and facilities is considered as a railway product. Therefore, it is qualified and authorized for acquiring the safety of rail cars and facilities. The software businesses shall again a Quality and Authority for applying a software to the rail cars and facilities. This paper regulates some guidelines that are needed to develop a software. The procedures that a software developer performs are divided by plan, requirement, design, implementation, and maintenance. The procedures that a software verification person performs are classified by verification plan, requirement verification, design verification, implementation verification, testing verification, maintenance verification, and safety activity. The entire processes and detailed activities to develope and verify a software are described as new guidelines.

• 한국전산구조공학회논문집
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• 제23권4호
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• pp.425-434
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• 2010

본 연구에서는 고층건물 구조시스템의 다양한 대안으로부터 이들의 성능을 합리적으로 평가하는 방안을 제안하였다. 대안평가는 업무절차에 따라 예비평가, 본평가, 실시평가로 나누어 수행된다. 대안평가를 위한 평가범주는 구조성능, 경제성, 공기의 세 가지로 구성되고, 각 평가범주는 이들을 평가하기 위한 세부 평가항목으로 구성된다. 예비평가에서는 경험지식에 의한 정성적인 평가를 수행하며, 본평가와 실시평가에서는 수치적인 결과를 바탕으로 주로 정량적인 평가를 수행한다. 평가결과의 종합화는 평가항목들간의 관계가 선형적이라는 가정하에 가중평균법을 적용하였다. 제안된 대안평가 방안은 실무예제에 대한 시뮬레이션을 통하여 그 적용성을 검토하였다.

• 수산경영론집
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• 제42권3호
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• pp.15-29
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• 2011

The Fish Stock Rebuilding Plan (FSRP) is evaluated as one of the most effective fisheries policies domestically and internationally. FSRP is a comprehensive fisheries policy, including target stock size, rebuilding period, application of management measures, and participation of fishermen. The performance outcomes of FSRPs have been partially evaluated for recommendation for stock rebuilding in Korea, while they are fully evaluated in other countries that have implemented FSRPs. The performance evaluation system for FSRP is very needed to enhance its effectiveness as one of fisheries policies. That is, the system where problems can be reconsidered, achieving targets can be evaluated, and the plan can be modified should be implemented. This study classified the performance evaluation of FSRP into the economic evaluation as a quantitative analysis and the policy evaluation as a qualitative analysis. In the economic evaluation, the sustainability of fishery resources, the stability of fishing business, the efficiency of fishery production, and efficient utilization of fishery resources can be considered. As analytical methods for the economic evaluation, the bioeconomic model, efficiency estimation model, the dynamic MEY model can be utilized. The qualitative evaluation is to assess the qualitative performances of FSRPs, including interviews and surveys with fishermen and fisheries experts. In the survey, many different items can be included by evaluation factors which are related to policies such as timeliness, transparency, effectiveness, etc. In addition, the study suggested the performance evaluation system and procedures for objective and efficient evaluation of FSRPs. In order to practically apply the developed performance evaluation model, the pilot project is needed. That is, from the application of pilot project, detailed research methods, effective procedures, and evaluation factors can be investigated.

• 한국기계가공학회지
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• 제20권5호
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• pp.47-54
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• 2021

In this study, systems and procedures for improving the research and development and purchasing projects for defense specifications were investigated, and the current situation was analyzed in terms of the disclosure and establishment of defense specifications. I would like to discuss the measures that need to be taken to improve the specification affairs of our defense sector in order to improve the production quality of military supplies. It should be noted that it is necessary to establish specifications and procedures for improving the quality of domestically purchased military supplies. Therefore, it is highly imperative to systematically establish detailed performance, and miscellaneous specifications in order to actively respond to the rapid development of superior private technologies. In addition, the barriers in the entry of the defense industry should be removed through active disclosure of the specification data, and the opportunities for participation should be expanded to promote a smooth follow-up logistics support and to improve the quality of military supplies

• Computers and Concrete
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• 제14권2호
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• pp.193-209
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• 2014

Cyclic test of the columns is of practical relevance to the performance of compression members during an earthquake loading. The strength, ductility and energy absorption capabilities of reinforced concrete (RC) columns subjected to cyclic loading have been estimated by many researchers. These characteristics are not normally inherent in plain concrete but can be achieved by effectively confining columns through transverse reinforcement. An extensive experimental program, in which performance of four RC columns detailed according to provisions of ACI-318-08 was studied in contrast with that of four columns confined by a new proposed technique. This paper presents performance of columns reinforced by standard detailing and cast with 25 and 32 MPa concrete. The experimentally achieved load-displacement hysteresis and backbone curves of two columns are presented. The two approaches which work in conjunction with Response 2000 have been suggested to draw analytical back bone curves of RC columns. The experimental and analytical backbone curves are found in good agreement. This investigation gives a detail insight of the response of RC columns subjected to cyclic loads during their service life. The suggested analytical procedures will be available to the engineers involved in design to appraise the capacity of RC columns.

• Earthquakes and Structures
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• 제15권5호
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• pp.487-498
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• 2018

Buckling-restrained braces are passive control devices with high level of energy dissipation ability. However, they suffer from low post-yield stiffness which makes them vulnerable to severe ground motions, especially near-field earthquakes. Among the several methods proposed to improve resistance of BRB frames, mega-brace configuration can be a solution to increase frame lateral strength and stiffness and improve distribution of forces to prevent large displacement in braces. Due to the limited number of research regarding the performance of such systems, the current paper aims to assess seismic performance of BRB frames with mega-bracing arrangement under near-field earthquakes via a detailed probabilistic framework. For this purpose, a group of multi-story mega-BRB frames were modelled by OpenSEES software platform. In the first part of the paper, simplified procedures including nonlinear pushover and Incremental Dynamic Analysis were conducted for performance evaluation. Two groups of near-fault seismic ground motions (Non-pulse and Pulse-like records) were considered for analyses to take into account the effects of record-to-record uncertainties, as well as forward directivity on the results. In the second part, seismic reliability analyses are conducted in the context of performance based earthquake engineering. Two widely-known EDP-based and IM-based probabilistic frameworks are employed to estimate collapse potential of the structures. Results show that all the structures can successfully tolerate near-field earthquakes with a high level of confidence level. Therefore, mega-bracing configuration can be an effective alternative to conventional BRB bracing to withstand near-field earthquakes.

• Structural Engineering and Mechanics
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• 제73권4호
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• pp.447-454
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• 2020

Seismic isolation technology has a wide application to protect bridges from earthquake damage, a new designed bridge pier with seismic isolation are provided for railways in seismic regions of China. The pier with rocking isolation is a self-centering system under small and moderate earthquakes, and the unbonded prestressed tendons are used to prevent overturning under strong earthquakes. A numerical model based on pseudo-static testing results is presented to evaluate the seismic performance of isolation bridge piers, and is validated by the shaking table test. It is found that the rocking response and the loss of prestressing for the bridge pier increase with the increase of earthquake intensity. Besides, the intensity and spectral characteristics of input ground motion have great influence on displacement of the top and bottom of the bridge pier, while have less influence on the bending moment of the pier bottom. Experimental and numerical results show that the rocking-isolated piers presented in this study have good seismic performance, and it provides an alternative way for the railway bridge in the regions with high occurrence of earthquakes. Therefore, we provide the detailed procedures for seismic design of the rocking-isolated bridge pier, and a case study of the seismic isolation design with rocking piers is carried out to popularize the seismic isolation methods.

• Membrane and Water Treatment
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• 제6권1호
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• pp.15-26
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• 2015

The compact structure and high-quality effluent of membrane bioreactors make them well-suited for decentralized greywater reclamation. However, the occurrence of membrane fouling continues to limit their effectiveness. To address this concern, a unique membrane module configuration was developed for use in a decentralized greywater treatment system. The module featured local aeration directly below a series of inclined membrane bundles, giving the overall module a twisted appearance compared to a module with vertically orientated fibres. The intent of this design was to increase the frequency and intensity of collisions between rising air bubbles and the membrane surface. Material related to the construction of custom-fit modules is rarely communicated. Therefore, detailed design and assembly procedures were provided in this paper. The twisted module was compared to two commercially available modules with diverse specifications in order to assess the relative performance and marketability of the twisted module with respect to existing products. Contaminant removal efficiencies were determined in terms of biochemical oxygen demand, chemical oxygen demand, ammonia, total nitrogen, total phosphorus, and turbidity for each module. Membrane fouling was monitored in terms of permeate flux, transmembrane pressure, and membrane resistance. Following 168 h of operation, the twisted module configuration demonstrated competitive performance, indicating good potential for further development and commercialization.