• Journal of Biosystems Engineering
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• v.42 no.2
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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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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• v.25 no.2
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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.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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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.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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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.

• Journal of Korean Library and Information Science Society
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• v.43 no.4
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• pp.183-199
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• 2012

This study is to develop an operating model of Conspectus for online resources by using mechanistic quality factor. Based on some empirical statistics about resource use behaviour such as collection rate, use rate, search rate, the mechanistic quality factor was calculated and applied to each subject by adjusting its acquisition level of Conspectus. according to the result of this study, Acqusition levels of the subject such as technical science which shows higher in use rate, and those such as history and social science which show higher in search rate, should be adjusted to a higher acquisition level, and those of others to the same or a lower level.

• Journal of Korea Trade
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• v.23 no.5
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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.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.1
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• pp.201-221
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• 2015

The purpose of this study is to suggest the usability of collection evaluation methods for collection development policy in public libraries. To achieve this purpose, this study applied Bonn's Use Factor, Turnover Rate of Collection, and Trueswell's 80/20 Rule to actual circulation data of the Gwangjin District Public Library in Seoul during last ten years. This study added practical meanings and values in collection evaluation through the analysis of total holdings and subject classes. Main items of analysis are the rate of use to total holdings and to holdings in specific subject classes by year, and the rate of core collection circulation by year. The results show relations between the rate of use and library's performance through the analysis of the rate of use both total holdings and subject classes. The results also figure out user's patterns and library appraisal of community users through the analysis of circulation data. In addition, the analysis of core collection gives a good basis for an effective collection development policy.

• Proceedings of the KIEE Conference
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• 2001.07a
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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.

• Journal of Environmental Health Sciences
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• v.17 no.2
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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%.