• 전기학회논문지P
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• 제55권4호
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• pp.196-201
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• 2006

A electrical fault that may generate an electrical disaster is defined as any abnormal condition caused by reduction in the insulation strength. To find out the abnormal condition, periodical inspections have being performed every 3 years. Recently, the number of empty houses during normal working hours is rising by dramatic increase in the number of nuclear families and double income families. To define the potential risk of the electric installation, measurement of zero phase current has been being considered. But the measured value could not be adapted to an absolute reference to the installation because the measured zero phase current value also contained capacitive leakage current. Therefore, in this paper, the correlation between the condition of the electrical installation and the zero phase current was analyzed. The result focuses on to detect them in a cost efficient way.

• 대한안전경영과학회지
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• 제11권1호
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• pp.7-14
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• 2009

Protecting an infant from a risk of accident was an absolute responsibility and duty of parents in the past. As increase in the ratio of entering kindergartens, the demand of all day program also increases. In infancy, safety concerns are higher than other periods since infants are curious about objects and environments and that have stronger impulse of the spirit of inquiry. Since baby's functioning is poor, an ability of balance maintenance and an exercise function are not sufficiently developed. Further more, they lack a cognitive power about self-control or situation. According to Korea Consumer Agency, safety accidents in infant institution have increased in 115% as 294 cases compared with 137 cases in 2004. Major causes of infant deaths are street accidents, drowning, and deaths from a fall in order. Considering this situation, we need to prevent and deal with accidents. Therefore this thesis grasp the situation and analyze an actual condition of an safety education about teachers who work in such institutions and infants who are educated in institutions to prevent from accidents and make up pleasant environments. Then, it will suggest all efficient safety education plans for infants to them.

• 대한안전경영과학회지
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• 제20권3호
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• pp.37-46
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• 2018

According to enhancement of roles and functions of enterprises' distribution centers, recent trend of distribution centers are specialization and diversification which have generated lots of new distribution center building or expansion of the existing ones and led attention on stock transfer importance in case of distribution center relocation. This thesis is a study for how to reduce stock transfer leadtime in order to minimize business risk and how to increase inventory accuracy when stock ownership is transferred in case of distribution center relocation, and to provide inventory accuracy management methods and inventory in/out management types, detailed definition to evaluate level for inventory accuracy management and pros/cons by inventory in/out management type assuming 'the higher inventory accuracy before stock transfer, the shorter stock transfer leadtime when distribution center is relocated'. This thesis provides detailed procedure to secure an absolute stock transfer leadtime and process to confirm hugh inventory accuracy by stakeholders which should be sloved by Task Force Team for stock transfer in case of distribution center relocation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 전기설비
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• pp.25-26
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• 2006

An electrical fault is defined as any abnormal condition caused by reduction in the insulation strength between energized conduction parts and ground or any grounded part of an electrical system. Failure of solid insulation can be caused by excessive mechanical tension being applied on the insulation, harsh service environment, aging, and also by corona phenomena. The number of empty houses during normal working hours is rising. As a result, the number of uninspected electric installation for general use is increasing. To define the potential risk of the electric installation, measurement of leakage current has been getting considered, but because the measured leakage current value also contained leakage current by capacitance, the measured value can not be adapted to absolute reference to the installation. Therefore, in this paper, the correlation between the condition of electric installation and leakage current were analyzed.

• 청정기술
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• 제26권4호
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• pp.279-285
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• 2020

Laboratories and industrial processes typically involve the use of flammable substances. An important property used to estimate fire and explosion risk for a flammable liquid is the flash point. In this study, flash point data at 101.3 kPa were determined using a SETA closed cup flash point tester on the following solvent mixtures: {2,2,4-trimethylpentane + methylcyclohexane}, {2,2,4-trimethylpentane + ethylbenzene}, and {2,2,4-trimethylpentane + p-xylene}. The purpose of this work is to obtain flash point data for binary mixtures of 2,2,4-trimethylpentane with three hydrocarbons (methylcyclohexane, ethylbenzene, and p-xylene), which are representative compounds of the main aromatic hydrocarbon fractions of petroleum. The measured flash points are compared with the predicted values calculated using the GE models' activity coefficient patterns: the Wilson, the Non-Random Two-Liquid (NRTL), and the UNIversal QUAsiChemical (UNIQUAC) models. The non-ideality of the mixture is also considered. The average absolute deviation between the predicted and measured lower flash point s is less than 1.99 K, except when Raoult's law is calculated. In addition, the minimum flash point behavior is not observed in any of the three binary systems. This work's predicted results can be applied to design safe petrochemical processes, such as identifying safe storage conditions for non-ideal solutions containing volatile components.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1254-1254
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• 2022

The Multi-family Residential is one of the most famous building types for a rental property in the US. Often times it includes multiple residential buildings and some amenity facilities, including a clubhouse or leasing office, swimming pool, dog park, and garages. Since the building type is built for rental purposes, the construction planning is phased and it makes the project complicated. Detailed planning and execution are important for successful construction management. This paper provides some management practices that are applied to one of the multi-family residential construction projects in Phoenix, AZ. The Front End Planning (FEP) process performed by both owner and contractor is the first key to a successful construction project. Specifically, the early review of phased turnover strategy, grading, fire/Americans with Disabilities Act (ADA) compliance, and Mechanical/ Electricity/Plumbing/Technology (MEPT) will provide absolute benefit to the project. Second, using a scheduling method to control short-term schedules and long-term can provide the ability to manage the issues with agility. Third, material delivery and procurement dominate the both project schedule and cost. With this COVID-19 circumstance, it is hard to expect the material, equipment, and labor forces to be delivered on time with the contracted price. Managing floats are more than important to managing construction productivity. Risk management should work to share the risks fairly. Lastly, turnover is directly linked with the profit of the project for both owner and contractor. The communication between the owner and contractor to re-schedule the proper turnover schedule is important for the phased construction project.

• Korean Chemical Engineering Research
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• 제52권4호
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• pp.467-474
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• 2014

화학공정의 기초설계는 물질수지와 열수지 계산을 기초로 공정의 경제성을 확보하고 주어진 조건 내에서 원하는 제품을 생산 가능하도록 한다. 이 단계를 통해 공정은 사용될 물질과 반응, 설비의 구조와 운전 조건 등이 결정되기 때문에 이후 바뀔 수 없는 고유한 특성을 갖게 된다. 고유한 특성은 뛰어난 경제성일 수도 있지만 다양한 잠재적 위험요인을 내포하는 것일 수도 있다. 따라서 기초설계를 위한 공정모사와 정량적 위험성 평가 기법의 통합을 통해 보다 안전하면서도 경제적인 공정을 설계하는 것이 중요하다. 본 논문에서는 LNG 액화공정을 Aspen HYSYS를 이용하여 모사하고, 폭발 사고에 대한 정량적 위험성 평가를 수행함으로써 잠재적 위험성을 최소화하면서도 경제성을 고려하도록 설계변수를 결정하였다. 이를 위해 확률적 최적화 방법론을 이용하여 Aspen HYSYS의 최적화 한계를 극복하였고, Aspen HYSYS와 Matlab의 연동을 통해 정량적 위험성 평가의 정확성을 높이며 최적화를 용이하게 하였다. 정량적 위험성 평가 결과, 공정 변수 중 안전성 확보를 위해 중요한 변수는 혼합냉매의 압력이었고, 0.5~10%의 운전비용 증가를 통해 잠재적 위험성을 4~18% 줄일 수 있었다. 비용을 크게 증가시킬수록 위험성의 절대적 수치는 낮아지지만 비용 대비 위험성 감소의 효과는 떨어졌다. 이처럼 공정모사와 정량적 위험성 평가 기법의 통합은 태생적으로 보다 안전한 공정의 설계가 가능하게 하고, 기초설계 단계에서부터 공정 내 위험요인을 수치적으로 확인할 수 있어 위험요인이 적은 특성을 갖도록 공정을 설계하는데 도움이 될 것이다.

• 한국수자원학회논문집
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• 제40권5호
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• pp.383-396
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• 2007

기존의 댐 계획이나 운영에서는 댐의 홍수조절 효과분석을 위해 댐 홍수조절 기여도 평가, 유황변화, 환경생태학적 변화 및 댐 하류의 수위저감효과를 사용하고 있다. 그러나 이와 같은 분석방법은 댐의 홍수조절에 의한 경제석 효과를 명확하게 제시할 수 없기 때문에, 댐의 치수역할과 필요성에 대한 국민적 공감대 형성이나 댐 사업의 타당성을 정확하게 평가하고 알리기에는 한계가 있다고 판단된다. 따라서 본 연구에서는 댐의 홍수조절에 의한 효과를 보다 분명하고 정확하게 산정하기 위하여 기존의 수위저감효과와 더불어 홍수피해 절감량이 얼마나 발생하였는지를 정량화할 수 있는 방법론을 개발하였다. 제안된 방법론에서는 홍수위 조건에 따라 위험상태기준을 잠재안전, 상대위험, 절대위험의 세 가지 상태로 정의하여 이에 따라 홍수피해 절감량을 제시한다. 구축된 방법을 남한강 유역의 2006년 7월 집중호우를 대상으로 충주댐의 홍수조절에 의한 여주지점에서의 수위차감효과와 이에 따른 경제적 효과를 분석하였다. 적용결과 피해경감량은 4조 1,890억원으로 산정되었다. 본 연구에서 제시한 댐의 홍수조절에 대한 경제적 효과분석은 댐의 홍수조절 효과나 증요성을 이해하는데 큰 기여가 될 수 있을 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권12호
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• pp.4963-4968
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• 2014

Background: We evaluated whether providing health risk appraisal for Koreans (KHRA) in terms of 'health age' during smoking cessation program would effectively help smokers quit smoking or not. Materials and Methods: A total of 332 male smokers aged between 30-65 years old, registered for a smoking cessation program in a public health center in a city, were recruited and underwent a baseline survey from January 2010 to February 2011. They were then prospectively randomized to a conventional counseling group (n=165) or a KHRA group (n=167), and received conventional counseling or KHRA-based counseling for six months. Abstinence rates were identified through carbon monoxide measurement (at the $4^{th}$ and $24^{th}$ weeks) or urinary cotinine level (at the $12^th$ week). Results: The abstinence rate confirmed by exhaled carbon monoxide was significantly higher in the KHRA group (61.1%) than the control group (49.1%) at the $4^{th}$ week (absolute difference 12.0%, 95% CI: 1.4%-22.6%). However, there was no difference in abstinence rates between the two groups at the 12th and 24th weeks. The predicting factors of 24 week's smoking cessation success were age, older than 50 years old (OR 2.02, 95% CI: 1.16-3.52), lower Fagerstr$\ddot{o}$m Test for Nicotine Dependence score less than 4 (OR 1.84, 95% CI: 1.03-3.29), and higher Self Efficacy/Temptation score (OR 1.79, 95% CI: 1.05-3.06). Conclusions: Smoking cessation counseling with KHRA could be effective compared to conventional counseling in the short period of smoking cessation. Further study is needed to evaluate the long-term efficacy of KHRA in tobacco dependence treatment and to establish the indication and target population of this tool.

• Asian Pacific Journal of Cancer Prevention
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• 제15권13호
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• pp.5337-5341
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• 2014

Background: The standard therapy for stage I rectum cancer is surgical resection. Currently, there is no strong evidence to suggest that any type of adjuvant therapy is beneficial. The risks of local relapse and distant metastasis are higher in rectal tumors. Therefore, while there is no clearly defined absolute indication for adjuvant therapy in lymph node negative colon cancers, rectum tumors that are T3N0 and higher require adjuvant treatment. Due to the more aggressive nature of rectal cancers, we explored the clinical and pathologic factors that could predict the risk of relapse in Stage I (T1-T2) disease and whether there was any progression-free survival benefit to adjuvant therapy. Materials and Methods: This multicenter study was carried out by the Anatolian Society of Medical Oncology. A total of 178 patients with rectal cancers who underwent curative surgery between January 1994 and August 2012 in 13 centers were included in the study. Patient demographics, including survival data and tumor characteristics were obtained from medical charts. Results: The median age was 58 years (range 26-85 years). Most tumors were well or moderately differentiated. For adjuvant treatment, 13 patients (7.3%) received radiotherapy alone, 12 patients (6.7%) received chemotherapy alone and 15 patients (8.4%) were given chemoradiotherapy. Median follow up was 29 months (3-225 months). Some 42 patients (23.6%) had relapse during follow up; 30 with local recurrence (71.4%) whereas 12 (28.6%) were distant metastases. Among the patients, 5-year DFS was 64% and OS was 82%. Mucinous histology and receiving adjuvant therapy were found to have statistically insignificant correlations with relapse and survival. Conclusions: In our retrospective analysis, approximately one quarter of patients exhibited either local or systemic relapse. The rates of relapse were slightly higher in the patients who had no adjuvant therapy. There may thus be a role for adjuvant therapy in high-risk stage I rectal tumors.