• 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.

• 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 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.

• 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.

• 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 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.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.2
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• pp.145-149
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• 2003

We consider the estimation of failure rate and acceleration factor under type-I censoring without using acceleration model when testing is conducted in only one highly accelerated condition. Failure times of an item are assumed to be exponentially distributed. It is also assumed that the uncertainty about the acceleration factor, the failure time contraction ratio between accelerated condition and use condition, can be modeled by the uniform or gamma prior distribution of appropriate parameters. We respectively use Bayes and maximum likelihood approaches to estimate acceleration factor and failure rate in the use condition. An example is given to show how the method can be applied.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.88-91
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• 2001

The purpose of this study is to localize the recharge rate into the national scale, calculated by use of the groundwater level from the 123 monitoring stations. The soil type, land use type, and bedrocks are selected for the influential factors over recharge rate. The main hypothesis is that the recharge rate can be expressed by the sum of the weighted averages of recharge rates of each factors. The optimized weights of soil type, land-use time and bedrocks from 119 stations are 0.80, 0.18 and 0.02 respectively. So this study offers that localization is available from the recharge rates calculated by groundwater level monitoring results.