• Title, Summary, Keyword: Expected efficiency

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Economic Constant Stress Plans for Accelerated Life Testing (가속수명시험을 위한 경제적 일정스트레스 계획의 개발)

  • Seo, Sun-Keun;Kim, Kap-Seok
    • Journal of Korean Institute of Industrial Engineers
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    • v.25 no.4
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    • pp.517-526
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    • 1999
  • This paper deals with two economic optimal designs of constant-stress accelerated life test(ALT) where failure distribution follows one of location-scale family, i. e., exponential, Weibull, and lognormal distributions which have been ones of the popular choices of failure distributions. Two optimization criteria to develop ALT plans are the statistical efficiency per unit expected cost which consists of the fixed test cost, cost being proportional to the number of test units, and variable test cost depending on test period and stress level, and the expected loss which combines Taguchi's quadratic loss function and expected test cost. Optimum plan determines the low stress level, test units allocated to each stress, and censoring times at two stress levels under Type I censoring. The proposed ALT plans are illustrated with a numerical example and sensitivity analyses are conducted to study effects of pre-estimates of design parameters.

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유류오염토양 복원을 위한 설계인자 선정에 관한 연구

  • 조장환;전권호;서창일;박정구
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.293-296
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    • 2004
  • The objective of this study was to decide the designing factor for remediaton of the contaminated site. The soil and ground-water samples were analyzed and hydro- geological characteristics was assayed for the survey of pollution level. Also air-permeability test and MPN(most probable number) test were conducted for selecting the designing factor. The contaminants were mainly found in north-west part of the site and were expected to move toward the south. Ex-situ technology was expected more useful than in-situ one with the results of air-permeability test saying that air permeability was relatively low. Additional microbes were expected for remediation efficiency because residual microbes were loosely populated. The choosing of the designing factor was requisite for remediation of contaminated site.

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The Causal Relationship between the Acceptance Attitudes and the Expected Effects of Smart Work

  • Park, Kiho
    • Journal of Information Technology Applications and Management
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    • v.21 no.1
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    • pp.151-163
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    • 2014
  • This paper explores the causal relationship between acceptance attitudes and expected effects of smart work. With the rapid development of smart technologies, lots of organizations try to innovate in the conventional working styles for maximizing organizational effectiveness and efficiency. Although many organizations wish to foster smart working environment, they don't have confidence in detailed action plans and effects from it. Therefore, this study that explores the causal relationship between acceptance attitudes and effects may have crucial meaning to organizations pursuing smart work. In this research empirically conducted by questionnaire survey, the acceptance attitudes as predictors and the expected effects of smart work as influenced variables were used. This research analyzed 118 collected data and multiple regression analysis. As a result of analysis, teleworking shows the positive relations to all of dependent variables. And others have a positive or negative influence on effects of smart work. Results of this study may give implications to organizations that want to implement smart work environment.

An Economic Design of the Chart with Variable Sample Size Scheme

  • Park, Chang-Soon;Ji, Seon-Su
    • Journal of the Korean Statistical Society
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    • v.23 no.2
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    • pp.403-420
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    • 1994
  • An economic design of the $\bar{X}-R$ chart using variable sample size (VSS) scheme is proposed in this paper. In this design the sample size at each sampling time changes according to the values of the previous two sample statistics, sample mean and range. The VSS scheme uses large sample if the sample statistics appear near inside the control limits and smaller sample otherwise. The set of process parameters, such as the sampling interval, control limits and the sample sizes, are chosen to minimize the expected cost per hour. The efficiency of the VSS scheme is compared to the fixed sample size one for cases where there is multiple of assignable causes. Percent reductions of the expected cost in the VSS design are calculated for some given sets of cost parameters. It is shown that the VSS scheme improves the confidence of the procedure and performs statistically better in terms of the number of false alarms and the average time to signal, respectively.

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A Comparative Study on Acceptance Attitudes and Expected Effects : Organizations between Korea and Canada (한국과 캐나다 조직간 원격근무 수용태도와 기대효과에 대한 비교 연구)

  • Park, Kiho
    • Journal of Information Technology Applications and Management
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    • v.24 no.4
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    • pp.25-39
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    • 2017
  • This research conducted empirical and comparative study following interview concerning the relationship of acceptance attitudes and expected effects of the teleworking between Korean and Canada organizations. Independent variable was acceptance attitude, and the expected effect as dependent variable. Totally, 201 responded questionnaires (Korea : 118, Canada : 83) were analyzed for multiple regression and mean difference between groups. On January 1, 2015, Canada had agreed FTA (free trade agreement) with Korea. Therefore, many organizations can have opportunities for sharing hands in social infrastructures and business area. As a result, the research found out that teleworking can positively improve employee's quality of life, efficiency of works. Moreover, respondents informed us that it may give us national and social cost saving. The BYOD (bring your own device) will be helpful to make employees do more active communication. This comparative research expects that two countries have some insights to cooperate in smart work or teleworking. In addition, several Korean companies can have chances to export IT technologies to Canada market.

A Study on the Causal Relationship between the Expected Effects by Acceptance Attitudes of Smart Work (스마트워크에 대한 조직구성원의 수용태도와 기대효과간 인과관계에 관한연구)

  • Park, Kiho
    • Journal of Information Technology Services
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    • v.13 no.4
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    • pp.65-78
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    • 2014
  • In this study, I explored the causal relationship between acceptance attitudes and the expected effects of smart work. With the rapid development of smart technologies, lots of organizations try to innovate in the conventional working styles for maximizing organizational effectiveness and efficiency. Although many organizations wish to foster smart working environment, they don't have confidence in detailed action plans and effects from it. Therefore, this study that explores the causal relationship between acceptance attitudes and effects may have crucial meaning to organizations pursuing smart work. In this research empirically conducted by questionnaire survey, the acceptance attitudes as predictors and the expected effects of smart work as influenced variables were used. This research analyzed 118 collected data and multiple regression analysis. As a result of analysis, teleworking shows the positive relations to all of dependent variables. And others have a positive or negative influence on cognitive effects of smart work. Results of this study may give implications to organizations that want to implement smart work environment.

A Study on the Effective Utilization Plan through Field Investigation and Analysis with Power Transformers in Domestic Areas

  • Shin, Heung-Sik;Lee, Jae-Cheon;Bai, Seok-Myung;Kim, Seon-Gu;Kim, Jin-Tae;Kim, Gi-Hyeon;Jeong, Jong-Wook;Bang, Seon-Bae
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.4
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    • pp.88-95
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    • 2007
  • Korea is highly dependent on foreign countries for energy while at the same time having a high energy-consumption industrial structure. Therefore, logical improvements in energy use efficiency and nationwide energy saving are becoming more and more important in coping with the worldwidehigh oil prices and environmental issues such as listed in the Kyoto Protocol to the United Nations Framework Convention on Climate Change. Consequently, a study was conducted on the average annual load factor in domestic areas to set a reasonable and reliable technology standard plan for high-efficiency transformers. The average annual load factor in Korea was discovered to be 18.4[%] classified by industry. This factor is expected to be used in arranging a domestic standard for a minimum efficiency system for transformers, and in reviewing and supplementing the standard transformers plan for the High Energy-Efficiency Appliance Certification. The expected effect from the establishment of the technology standards plan for highly efficient transformers is the expansion of the manufacturing and distribution of highly efficient transformers that are suitable for domestic use. These will lead to electricity cost savings for users, strengthening the related industries' market competitive powers and the effective reduction of greenhouse gases on a national level by drastically reducing loss from transformers, which accounts for a large portion of the total electric supply losses.

A Study on Coil Misalignment in a 3-Coil Magnetic Resonance Wireless Power Transmission System of a Electric Vehicle (전기자동차의 3-코일 자기공진방식 무선전력전송 시스템에서 코일의 비 정렬에 관한 연구)

  • Hwang, In-Gab
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.1
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    • pp.48-55
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    • 2021
  • The 3-coil magnetic resonance wireless power transmission system was analyzed using an equivalent circuit model, and the |S21| of the system was expressed as the equation of the Q of the three coils, the coupling coefficient k between the transmitting coil and the relay coil, the relay coil and the receiving coil. It is suggested that the maximum efficiency can be obtained when the relay coil is located in the center of the transmitting and the receiving coil. When the distance between the transmitting and the receiving coil is 30 cm and the two coils are aligned, maximum efficiency of 9 % is obtained with the relay coil centered between the coils. If the transmitting coil and the receiving coil are misaligned during a wireless charging of an electric vehicle, the efficiency is expected to decrease significantly compared to the aligned case. It is expected that the efficiency can be increased by using a relay coil and by rotating the coil.

A Clinical analysis on the Treatment efficiency of Tinnitus by Types of bianzheng(辨證) (耳鳴의 形態와 治療效率에 對한 臨床的 分析)

  • Kim, Gyung-jun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.12 no.2
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    • pp.182-188
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    • 1999
  • Tinnitus is a symptom frequently encountered in the E.N.T. clinic and variously described as buzzing, ringing and thumping sound, etc., but the cause, pathogenesis, specific treatment remains to be established through close investigation. In fact, it is not easy to evaluate the treatment efficiency of tinnitus reasonably. However, in this study. we clinically investigated 47 patients who visited E.N.T. department of Kyung Won University Hospital from May. 1996 to May. 1999 and belonged to specific bianzheng(辨證) types of tinnitus classified by bianzheng(辨證), a kind of diagnostic method in order to estimate efficiency of the treatment and give aids to establishing more effective and recognizable treatment method. The result is as follows: 1) In bianzheng(辨證) types of tinnitus, Piweixuruo(脾胃虛弱) was most frequently found, in descending order, Shenjingkuisun(腎精虧損), Ganhuoshangra(肝火上擾), Tanhuoyongjie(痰火壅結). 2) In the treatment efficiency, the type of Piweixuruo(脾胃虛弱) showed the highest, in descending order, Ganhuoshangrao(肝火上擾), Tanhuoyongjie(痰火壅結) and Shenjingkuisun(腎精虧損). 3) The treatment efficiency is shown higher in patients with tinnitus included in other sysmptoms than those with a simple symptom of tinnitus. especially in case of tinnitus accompanied by vertigo, we could get much higher treatment efficiency more than we had expected.

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Classification Index and Grade Levels for Energy Efficiency Classification of Agricultural Heaters in Korea

  • Shin, Chang Seop;Jang, Ji Hoon;Kim, Young Tae;Kim, Kyeong Uk
    • Journal of Biosystems Engineering
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    • v.38 no.4
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    • pp.264-269
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    • 2013
  • Purpose: This study was carried out to develop a classification index and grade levels to rate agricultural heaters for energy efficiency classification. Methods: The classification index was developed mainly by taking simplicity of calculation and easy access to relevant data into consideration. The grade levels were developed on the basis of a 5-grade classification system in which graded heaters are to be normally distributed over the grades. The value of each grade level were determined in terms of the classification index values calculated using the published performance data of agricultural heaters tested at the FACT in Korea over the past 12 years. Results: The thermal efficiency of agricultural heaters based on the enthalpy method was proposed as a reasonable classification index. The grade levels were proposed in equation form for three types of agricultural heaters: fossil fuel heaters, wood pellet heaters and wood pellet boilers. A reasonable energy efficiency classification of agricultural heaters could be performed using the proposed classification index and grade levels. Conclusions: It is expected that energy saving programs will be extended to agricultural machines in the near future. The classification index and grade levels to rate agricultural heaters for energy efficiency classification were developed and proposed for such near future to come.