• 토지주택연구
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• 제9권1호
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• pp.1-9
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• 2018

As the government announced Real Estate Policies on August 02, most areas except for Seoul cities face increasing business risks. Moreover, the government control over financial sectors' loan leads to the highly possible contraction of new distribution markets. The market trend could bring about the reduction of new demand in PF (Private Financing) business that large construction companies mainly concentrate on, and even the business already obtained has a high risk of being distributed, which could result in substantially low profitability. The currently unstable financial structure of most construction companies is caused by the hike of the prime cost of foreign plants except for that of a few construction companies. If PF (Private Financing) business also faces a difficult situation in such a financial condition, even large construction companies come to have the high possibility of a deficiency in credit rating. Accordingly, the major business that large construction companies concentrate on needs the sufficient business review. It is desirable to make a bid for business guaranteeing stability rather than business solely in consideration of profitability, when participating in a competition for a new construction contract.

• 한국안전학회지
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• 제21권2호
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• pp.22-28
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• 2006

This paper presents assessment of possibility on the human risk for the electromagnetic field of unbalanced two coupled three-phase transmission line using fuzzy theory. Three phase load flow program was developed which employed a Newton-Raphson method as a tool to analyze system unbalanced. This research presents a method of handling two coupled three phase transmission system unbalance analysis and unbalanced power demand as a function of voltages. As the results of case study, in case of 345[kV] T/L, the electric field intensity was 10.9540[kV/m], magnetic field intensity was 0.2567[G] in severest case. The results showed that the membership of a proposition fuzzy '10.9540 [kV/m] is hazardous' is 0.6349. As the analytic results using the fuzzy qualifier term, the membership in case of very false is 0.1379 and fairly false is 0.6124, respectively. In assessment of fuzzy measure possibility for the electromagnetic field, this paper used probability of fuzzy arid measure of fuzziness technique.

• 상하수도학회지
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• 제29권3호
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• pp.305-317
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• 2015

The function failure of present major facilities is likely to lead to failure of related systems and/or whole facilities, increasing the necessity for protection of infrastructures, main structures, and major industrial facilities. In addition, safe and efficient management for urban infrastructure (waterworks and sewerage facilities, electricity, telecommunications, roads, etc) installed in the basement or on large cities grounds at various public areas is required. Recently in response to this demand, efforts for vitalizing asset management are being made such as enacting related laws and developing asset management system in the U.S., Australia, Europe and other advanced countries with the concept for a new maintenance. In our county, identifying maintenance system problems such as aging and rapid increasing of existing infrastructures and decision-making about updating maintenance is required for systematic and organizational maintenance. In this study, by comparing and observing the LOS(Level of Service) of each countries' waterworks and risk-based LOS, we suggest the direction of future urban water infrastructure management systems for more effective management.

• Industrial Engineering and Management Systems
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• 제12권2호
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• pp.74-84
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• 2013

Modern companies have been facing devastating impacts from unexpected events such as demand uncertainties, natural disasters, and terrorist attacks due to the increasing global supply chain complexity. This paper proposes a multi stage logistic network model under disruption risk. To formulate the problem practically, we consider the effect of continuity rate, which is defined as a percentage of ability of the facility to provide backup allocation to customers in the abnormal situation and affect the investments and operational costs. Then we vary the fixed charge for opening facilities and the operational cost according to the continuity rate. The operational level of the company decreases below the normal condition when disruption occurs. The backup source after the disrup-tion is recovered not only as soon as possible, but also as much as possible. This is a concept of the business continuity plan to reduce the recovery time objective such a continuity rate will affect the investments and op-erational costs. Through numerical experiments, we have shown the proposed idea is capable of designing a resilient logistic network available for business continuity management/plan.

• Earthquakes and Structures
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• 제22권2호
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• pp.109-120
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• 2022

Older or damaged structures can require significant retrofit to ensure they perform well in subsequent earthquakes. Supplemental damping devices are used to achieve this goal, but increase base shear forces, foundation demand, and cost. Displacement reduction without increasing base shear is possible using novel semi-active and recently-created passive devices, which offer energy dissipation in selected quadrants of the force-displacement response. Combining these devices with large, strictly passive energy dissipation devices can offer greater, yet customized response reductions. Supplemental damping to reduce response without increasing base shear enables a net-zero base shear approach. This study evaluates this concept using two incremental dynamic analyses (IDAs) to show displacement reductions up to 40% without increasing base shear, more than would be achieved for either device alone, significantly reducing the risk of response exceeding the unaltered structural case. IDA results lead to direct calculation of reductions in risk and annualized economic cost for adding these devices using this net-zero concept, thus quantifying the trade-off. The overall device assessment and risk analysis method presented provides a generalizable proof-of-concept approach, and provides a framework for assessing the impact and economic cost-benefit of using modern supplemental energy dissipation devices.

• 한국건설관리학회논문집
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• 제22권2호
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• pp.3-11
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• 2021

미얀마는 아시아 국가 중 개발 가치가 높은 미개발 국가이다. 이에 미국을 비롯한 다양한 국가에서 시장 진출을 고려하고 있는 상황이다. 이러한 측면에서 부동산 개발 프로젝트의 수요는 외국인들의 유입 증가와 미얀마 경제성장에 따라 증가할 것으로 예측된다. 하지만 미얀마는 국가적 리스크를 포함해 해외 진출기업의 측면에서 위험도가 높은 국가이다. 이에 본 연구에서는 미얀마에 관한 자료분석을 실시해 리스크 유발요인을 추출한 후 전문가(법률, 금융, 기술, 현지 전문가) 심층인터뷰를 실시하였다. 이를 통해 106가지 리스크 요인을 추출하였으며, 친화도법을 활용해 3차에 걸친 그룹핑 작업을 실시하여 최종 리스크 분류 체계를 구축하였다. 그리고 AHP 기법을 활용해 각 요인별 상대적 중요도를 분석하여 제시하였다. 그 결과 해당 국가 관련 리스크, 자금 관련 리스크, 분양 관련 리스크의 중요도가 높게 나타났다. 본 연구결과는 미얀마 부동산 개발형사업의 진출기업에게 리스크관리 기준을 제공할 것으로 기대된다.

• 한국해양공학회지
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• 제32권2호
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• pp.95-105
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• 2018

An FLNG (floating liquefied natural gas) or LNG FPSO (floating production, storage and offloading) unit is a notable offshore unit with the increasing demand for LNG. The liquefaction process on an FLNG unit is the most important process because it determines the economic feasibility, but would be a hazard source because of the large quantity of hydrocarbons. While a high efficiency process such as C3MR has been preferred for onshore liquefaction processes, a relatively simple process such as the SMR (single mixed refrigerant) or DMR (dual mixed refrigerant) liquefaction process has been selected for offshore units because they require a more compact size, lighter weight, and higher safety due to their space limitation for facilities and long distance from shore. It is known that an SMR has the advantages of a simple configuration, small footprint, and lower risk. However, with an increased production rate, the inherent safety of SMR needs to be evaluated because of its small train capacity. In this study, the potential explosion risks of the SMR and DMR liquefaction processes were evaluated at the conceptual design stage. The results showed that an SMR has a lower overpressure than a DMR at the same frequency, only with a small production capacity of 0.9 MTPA. With increased capacity, the overpressure of the SMR was higher than that of the DMR. The increased number of trains increased the frequency in spite of the small amount of equipment per train. This showed that the inherent risk of an SMR is not always lower than that of a DMR, and an additional risk management strategy is recommended when an SMR is selected as the concept for an FLNG liquefaction process compared to the DMR liquefaction process.

• 한국의류학회지
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• 제31권5호
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• pp.670-679
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• 2007

Contemporary consumers interested in fashion develop global tastes regarding consumption and senses on how much certain products cost in the global market place. Demand for foreign brands and products produced a new type of e-tailor called surrogate Internet shopping malls. Due to the unfamiliarity of such retailers, consumers may perceive different types of risks and may show different styles of seeking informations. The research interest of this study was to investigate the differences of risk perception and information search between surrogate e-mall shoppers and general e-mall shoppers. In addition, we examined the influence of these two variables on consumer satisfaction. A survey questionnaire was developed. Measures of three types of e-shopping risks (delivery, transaction, service), information search and satisfaction were included. Data from surrogate e-mall consumers and general e-mall consumers were statistically analyzed. Surrogate e-mall shoppers showed a higher level of product delivery risk and customer service risk than general e-mall shoppers. They also spend more time in seeking information before making purchases. Regression analysis showed that perceived risk had significant influence on information search and consumer satisfaction for surrogate e-mall shoppers, whereas for general e-mall shoppers, no significant influence was detected. The findings should assist marketers and academics in their understanding of the surrogate e-shopping malls.

• 한국안전학회지
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• 제27권5호
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• pp.64-69
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• 2012

The concept of SIL is applied in the most of all standards relating to functional system safety. However there are problems for the people to apply SIL to their plants. as these standards don't include sufficient informations. In this regards, this paper will suggest the direction of SIL application and concept based on IEC 61508 and IEC 61511. A Safety Integrity Level(SIL) is the discrete level(one out of possible fours), corresponding to a range of the probability of an E/E/PE (Electric/Electrical/Programmable Electrical) safety-related system satisfactorily performing the specific safety functions under all the stated conditions within a stated period of time. SIL can be divided into the target SIL(or required SIL) and the result SIL. The target SIL is determined by the risk analysis at the analysis phase of safety lifecycle and the result SIL is calculated during SIL verification at the realization phase of safety lifecycle. The target SIL is determined by the risk analysis like LOPA(Layer Of Protection Analysis), Risk Graph, Risk Matrix and the result SIL is calculated by HFT(Hardware Fault Tolerance), SFF(Safe Failure Fraction) and PFDavg(average Probability of dangerous Failure on Demand). SIL is applied to various areas such as process safety, machinery(road vehicles, railway application, rotating equipment, etc), nuclear sector which functional safety is applied. The functional safety is the part of the overall safety relating to the EUC and the EUC control system that depends on the correct functioning of the E/E/PE safety-related systems and other risk reduction measures. SIL is applied only to the functional safety of SIS(Safety Instrumented System) in safety. EUC is the abbreviation of Equipment Under Control and is the equipment, machinery, apparatus or plant used for manufacturing, process, transportation, medical or other activities.

• 인터넷정보학회논문지
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• 제21권2호
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• pp.27-37
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• 2020

최근 국내외 빅데이터가 4차 산업혁명의 핵심기술로 급부상하고 있다. 또한, 4차 산업혁명의 발달과 더불어 드론에 대한 활용도와 수요가 계속 증가하고 있으며, 이에 관한 결과로 이제 드론은 일상생활과 다양한 산업 활동에 많이 활용되고 있다. 하지만 드론의 활용이 많아지면서 추락의 위험 또한 높아지고 있다. 드론은 비행 시 드론 내부 특성상의 간단한 구조로 인하여 작은 문제에도 쉽게 추락할 수 있는 위험요소를 항상 가지고 있다. 본 논문에서는 이러한 드론 추락 위험요소를 예측하고 추락을 방지하기 위하여 드론의 구동 모터와 일체형으로 ESC(Electronic Speed Control)를 부착하고 그 안에 가속도 센서를 장착해 진동 데이터를 실시간으로 수집 및 저장하고 그 데이터를 실시간으로 처리 및 모니터링 한다. 그리고 모니터링 상황에서 얻어진 빅데이터를 통한 데이터를 고속 푸리에 변환(Fast Fourier Transform,FFT) 알고리즘을 이용하여 수집된 빅데이터를 분석하여 드론 추락의 위험을 최소화하는 예측시스템을 제안하였다.