• Journal of Biosystems Engineering
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• 제42권2호
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• pp.75-79
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• 2017

The use of tractors to carry out agricultural work has played an important role in mechanizing the agricultural sector. A repairable mechanical system (such as an agricultural tractor) is subject to deterioration or failure. In this study, a regression model was used to predict the failure rate of a John Deere 3140 tractor. The machine failure pattern was carefully studied, and key factors affecting the failure rate were identified in five regions of the Khouzestan province. Through a questionnaire, data was obtained from farm records. This data was grouped into six sub-groups, according to the annual use hours (AUH) and the manner in which the tractors were stored. Results showed that AUH and storage policies affected failure rate slightly. With an increase in the age of the tractors, the failure rate in the tractors used for 1050-2000 hours annually and stored outdoors was higher than those used for 200-1000 hours annually and stored in sheds. When the tractors were of the same age, the slope of the curve in the 200-1000 annual use hours increased gradually and then rapidly, but failure rate in the 1050-2000 annual use hours was high from the beginning, and subsequent increase in this value was almost uniform. As a result, it can be said that with an increase in the annual use hours, the failure and breakdown rate in John Deere 3140 tractors rapidly increases, but maintenance conditions only slightly affect the failure and breakdown rate.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.97-98
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• 2022

The purpose of this study is to find out the failure conditions of fire doors in the process of use and prepare maintenance measures against them and find out the failure conditions and failure rates of fire doors according to the period of use of buildings. According to a survey of the failure rate and failure factor of fire doors, the failure rate of fire doors under 5 years was 3.7%, 13.4% of fire doors under 5 years and 10 years, and 14.8% of fire doors under 15 years and 27.6% of fire doors over 20 years. In particular, 15 years later, the failure rate of fire doors exceeded 20%. The main defects were found to be natural aging, holes, opening and closing failures, gaps, and failure and wear of accessories such as gaskets and door closers.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• 제25권2호
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• pp.132-142
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• 2023

Objective: Dual antiplatelet therapy (DAPT) is usually temporarily used after stent-assisted coil embolization (SACE), and is commonly converted to mono antiplatelet therapy (MAPT) for indefinitely. In this study, we aimed to find the possibility of discontinuing MAPT, and to determine the proper period of DAPT use. Methods: We used the Standard Sample Cohort DB dataset from the National Health Insurance Sharing Service. Among approximately 1 million people in the dataset, SACE was performed in 214 patients whose data this study analyzed. The relationship between discontinuation of antiplatelet therapy and intracranial hemorrhage or cerebral infarction was analyzed using multiple logistic regression, considering all confounding variables. The survival rate according to the continuation of antiplatelet therapy was obtained using Kaplan-Meier analysis, and the difference in survival rate according to the continuation of antiplatelet therapy was verified using the log-rank test. The hazard ratio according to continuation of antiplatelet therapy was obtained using the Cox proportional hazards model. The analysis was conducted by applying the same statistical method to the duration of DAPT use. Results: Among 214 patients who underwent SACE, 50, 159 and five patients continued, discontinued and did not use antiplatelet therapy (except at the time of procedure), respectively. In multiple logistic regression analysis, discontinuation of antiplatelet agents (including aspirin) and the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction, considering various confounding factors. In the survival analysis according to the continuation of antiplatelet agents, patients who continued to use antiplatelet agents had a higher survival rate than those in other groups (p=0.00). The survival rate was higher in the rest of the group than in the group that received DAPT for three months (p=0.00). Conclusions: Continuation of antiplatelet agents or the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction. Considering the survival rate, it would be better to maintain at least three months of antiplatelet therapy and it might be recommended to continue DAPT use for 12 months.

• 대한인간공학회지
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• 제29권6호
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• pp.959-964
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• 2010

Seat belt is an important means to protect drivers and passengers from the damages by car accidents. Many ways to increase the seat belt wearing rate have been proposed through human factors researches. The primary ways to increase seat belt use rate have emphasized the intention-behavior cycle. This study focused on the gap between intention and behavior. The gap may be bridged by the habit for seat belt use behavior. Divers following a desirable car starting sequence, from sitting on the chair, fastening seat belt, starting engine to moving a car, reported that higher belt wearing rate and unconscious behavior (automated response). That is, the habitualized procedure knowledge prevented drivers from forgetting to fasten their seat belt. The reminder systems such as warning light and warning sound could not significantly give an influence in remembering to fasten seat belt. In order to increase the seat belt use rate, the desirable car starting procedure should be included in the driving education program.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.215-222
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• 1997

Flow experimental on not to be solid mortar which use Quenched Blast-furnace Slag as a fine aggregate was carried out for basic research data about fundamental study of application possibility of Quenched Blast-furnace Slag as a fine aggregate. It gives following result. The substitution rate is inversely proportional to Flow and C/S-rate same that. The relation with W/C-rate augment appear proportional : in case of C/S-rate, 1:3 increasing degree is a half of sand mortar that. Consequencely, Quenched Blast-furnace Slag motar is a counteraction to Flow in as same water content per unit. But suitable substitution rate and C/S-rate influence a little to the mortar consistency. And that reason, if C/S-rate and substitution rate will be regulated when we mix the mortar with quenched Blast-furnace Slag. that will be economic mixture.

• 한국도서관정보학회지
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• 제43권4호
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• pp.183-199
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• 2012

본 연구는 기계적 품질계수 개념을 도입하여 온라인자료에 적합한 컨스펙터스 운영모형을 개발하기 위한 것이다. 온라인자료의 주제별 소장율, 이용율, 검색율 등 자료활용행태에 관한 정보를 토대로 주제별 기계적 품질계수를 산출한 후 이를 기존의 컨스펙터스의 주제별 집서수준에 반영하는 방식으로 운영할 것을 제안하였다. 그 결과 이용율이 높은 기술과학과 검색율이 높은 역사와 사회과학 등 주제의 집서수준을 대폭 상향조정하고 여타주제들은 현행유지 또는 하향조정 되어야 하는 것으로 나타났다.

• Journal of Korea Trade
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• 제23권5호
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• pp.66-86
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• 2019

Purpose - This paper describes the use of trade preferences under the EU-Korea free trade agreement (FTA) and empirically examines potential reasons for the less than full use, using data on daily EU imports from Korea at the product level. Design/methodology - We employ a probit model to analyse the relationship between the use of trade preferences on the one hand and variables such as potential duty savings, rules of origin and the characteristics of the good traded (intermediate input or final product) on the other. Findings - The paper finds that EU imports from Korea make good use of trade preferences with an overall preference utilisation rate of close to 90% in 2016, which is up from about 80% in 2012. It further shows that potential duty savings influence preference utilisation positively and that more than one quarter of the observations in our sample made use of preferences under EU-Korea FTA in 2012, despite duty savings standing at €10 or less. Originality/value - The finding that a non-negligible share of observations use preferences even when the duty savings are low has not yet figured in the literature. We further show how preference utilisation rates differ by importing EU Member State and by section of the Harmonised System and estimate the marginal impact of an increase in potential duty savings on the preference utilisation rate by broad product group, which is novel.

• 한국문헌정보학회지
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• 제49권1호
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• pp.201-221
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• 2015

본 연구는 국내 공공도서관의 장서개발정책을 위하여 장서평가 방법을 실증적 데이터에 적용함으로서 그 활용 가능성을 제시하는데 목적이 있다. 이러한 목적을 위하여 서울시 광진정보도서관의 최근 10년간 장서대출 데이터를 활용하여 도서관 장서평가 방법 중에서 가장 신뢰성이 높은 Bonn의 이용계수, 소장도서 장서회전율과 Trueswell의 80/20 법칙을 적용하였다. 분석내용은 소장도서의 전체적 분석과 주제별 분석으로 장서평가에 대한 실질적인 가치와 의미를 부여하도록 하였다. 주요 분석항목으로는 연도별로 소장도서 전체 및 주제별 이용도 분석과 연도별로 대출 핵심장서의 비중 분석으로 구성되어 있다. 분석 결과, 장서 전체 이용도와 주제별 이용도의 변화를 분석함으로써 도서관에서 수행된 업무와 이용도 간의 관련성을 파악할 수 있으며, 장서대출 데이터 분석으로 이용자들의 장서 이용패턴에 대한 변화와 도서관 프로그램에 대한 지역주민의 평가를 파악할 수 있다. 아울러 대출도서 핵심장서의 비중 분석을 통하여 효과적인 수서정책을 위한 근거자료를 제시할 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.383-385
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• 2001

This paper presents electric power use pattern by end-use for each industry in Korea. Until now, the survey for industrial electric power use pattern by end-use has been sporadic and unsystematic. This paper presents the systematic survey and analysis for electric power use pattern by end-use. The major survey items include rate power and the number of equipments, and operation rate, etc. This paper will make good use of data base construction and policy for DSM.

• 한국환경보건학회지
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• 제17권2호
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• pp.27-34
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• 1991

This study was carried out to investigate the use habit of drinking water. The survey data were collected from 1,282 of students and 175 of officers from September 1990 to June 1991 in Pusan city and the South of Kyung sang-do. The use rate of tap water among respondents was 33.5%, and the reasons that the others avoid using tap water were having the risk of heavy metals contamination and unsanitary. The 80% of respondents have drunk spring water or bottled water within two or three years. The keeping method of them were 53% in the refrigerator, and 33% in the indoor. The use rate of water vessels what were equipped in mineral springs was 85%. It's advisable that the picking of mineral water be cautious within two or three days after rain. The holding rate of water purifier in respondents was about 20%, and it was purchased within one or two years and the reliance degree of that in users was below 50%.