• 한국시뮬레이션학회논문지
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• 제25권2호
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• pp.75-81
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• 2016

고정위치 생산 방식과 이를 개선한 흐름 생산 방식의 생산성을 비교하기 위해 데크하우스 선행의장 공정의 사례를 이용하여 이를 비교 분석하였다. 현재의 선행의장 공정 시스템은 고정위치 생산을 하고 있으며, 여기서는 블록이 한 구역을 점유하고, 작업이 완료 될 때까지 이동하지 않는다. 반면 개선된 흐름생산시스템에서는 블록이 이동하며 작업자와 장비는 움직이지 않는다. 시뮬레이션 결과 제안된 생산시스템에서 블록의 이동시간과 대기시간을 고려하지 않았을 때는 블록의 생산량이 거의 증가하지 않았다. 그러나 흐름생산에서는 작업을 위한 장비와 작업자의 이동과 대기시간이 거의 없어, 작업장의 작업시간의 변동성을 줄일 수 있다면 흐름생산이 고정위치 생산 시스템을 대체하는 보다 더 우수한 대안이 될 수 있음을 보였다.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.187-194
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• 2011

Optimizing truck dispatching-intervals is imperative in ready mixed concrete (RMC) delivery process. Intervals shorter than optimal may induce queuing of idle trucks at a construction site, resulting in a long delivery cycle time. On the other hand, intervals longer than optimal can trigger work discontinuity due to a lack of available trucks where required. Therefore, the RMC delivery process should be systematically scheduled in order to minimize the occurrence of waiting trucks as well as guarantee work continuity. However, it is challenging to find optimal intervals, particularly in urban areas, due to variations in both traffic conditions and concrete placement rates at the site. Truck dispatching intervals are usually determined based on the concrete plant managers' intuitive judgments, without sufficient and reliable information regarding traffic and site conditions. Accordingly, the RMC delivery process often experiences inefficiency and/or work discontinuity. Automatic data collection (ADC) techniques (e.g., RFID or GPS) can be effective tools to assist plant managers in finding optimal dispatching intervals, thereby enhancing delivery performance. However, quantitative evidence of the extent of performance improvement has rarely been reported to data, and this is a central reason for a general reluctance within the industry to embrace these techniques, despite their potential benefits. To address this issue, this research reports on the development of a discrete event simulation model and its application to a large-scale building project in Abu Dhabi. The simulation results indicate that ADC techniques can reduce the truck idle time at site by 57% and also enhance the pouring continuity in the RMC delivery process.

• 대한지역사회영양학회지
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• 제2권2호
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• pp.206-217
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• 1997

This study was designed to analyze and compare production management practices and labor productivity between conventional and commissary school foodservices and 46 dietitians of commissary school foodservices in Kyunggi-do. The response rates were 89.7% and 91.3$\%$, respectively. The number of meals served was ranged from less than 100 to over 1, 900 in conventional school foodservices and from 200 to 1, 600 in commissary foodservices. Thirty three conventional foodservices(42.3%) produced less than 300 meals per day. Numbers of satellite school per central kitchen were ranged from 1 to 5 schools ; fifty percent of commissary foodservices have contained 3 satellite schools. Meals for satellite schools were transported between 11:00 a.m.and 12:00 a.m ; transportation time was from 10 to 90 minutes. Waiting time before service in satellite schools was between 10 minutes and 80 minutes. Part time employees supported by parents were hired in 37.3$\%$ of conventional and 50$\%$ of commissary school foodservices. Voluntary workers were supplied for 64.9$\%$ of conventional and 52.4$\%$ of commissary school foodservices. Labor productivity was calculated from work schedule. Labor productivity(labor minutes per meal)was lowest in foodservices with 101-4-- meals(8.48 min)was lower than that of foodservices with above 401 meals ; no significant differences were found among 401-700(6.02 min), 701-1, 100(4.01 min), 1, 101-1, 500(3.41 min), and 1, 501-1, 900(3.15 min)meals in conventional foodservices. Labor minutes per meal of foodservices which served less than 400 meals(6.90 min) per day was significantly lower than those of foodservices which served 401-1, 900 meal(3.41-4.92 min) in commissary foodservices(p<0.05)

• 대한방사선기술학회지:방사선기술과학
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• 제35권1호
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• pp.45-50
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• 2012

국내병원 대부분의 CT검사실은 One Stop Services를 목표로 운영하여 예약환자는 물론이고 전처치가 준비된 외래환자의 경우 당일 CT검사를 수행하고 있다. 하지만 One Stop Service라는 목표에는 양적인 접근은 가능할지언정 지루한 대기시간, 직원의 불친절도 등에 의한 질적인 저하를 야기 시키게 되었고 환자와 보호자들의 민원을 발생시키는 등 검사에 대한 불만족으로 이어지기도 한다. 따라서 본 연구는 직원의 친절도 향상, CT검사에 대한 이해도 향상, CT검사실의 환경개선, 당일 CT검사 대기시간의 단축 등, CT검사를 받는 환자의 불편사항을 찾아 만족도 향상을 위한 방안을 도출하고자 한다. CT검사 외래환자 중 조영제를 투여하는 복부 CT검사 환자를 대상으로 하고 CT검사 외래환자의 만족도를 확인하기 위해 설문지를 사용하였으며 개선 활동 전인 48명, 개선 활동 후 41명, 총 89명의 설문지를 2011.4.1-2011.9.30까지 조사 하였다. 조사 방법은 직원의 친절도, CT검사 이해도, 환경 만족도는 설문을 통해서 조사하고 당일 CT검사 대기시간은 의료정보 통계로 조사하였으며 SPSS V. 15.0 을 이용하여 분석하였다. 개선 전과 개선 후의 전반적인 만족도를 비교한 결과 CT검사실 이용절차의 편리성은 Mean(SD) $5.83{\pm}2.06$에서 Mean(SD) $8.88{\pm}1.87$로 52.32%, 직원의 친절도는 Mean(SD) $7.15{\pm}1.72$에서 Mean(SD) $9.44{\pm}1.24$로 32%, 환경만족도는 Mean(SD) $5.90{\pm}1.89$에서 Mean(SD) $9.00{\pm}1.59$로 52.54%, CT검사의 이해도는 Mean(SD) $5.94{\pm}1.83$에서 Mean(SD) $9.05{\pm}1.70$로 52.36%가 각각 상승하였다. 또한 대기시간은 평균 25.33분에서 21.04분으로 약 16.93% 단축시키는 큰 효과를 얻을 수 있었고 병원의 경쟁력 강화와 수익 증대에도 기여할 것으로 사료 된다.

• 로봇학회논문지
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• 제15권2호
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• pp.100-106
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• 2020

In the agricultural field, interests in research using robots for fruit harvesting are continuously increasing. Dual arm manipulators are promising because of its abilities like task-distribution and role-sharing. To operate it efficiently, the task sequence must be planned adequately. In our previous study, a collision-free path planning method based on a genetic algorithm is proposed for dual arm manipulators doing tasks cooperatively. However, in order to simplify the complicated collision-check problem, the movement between tasks of two robots should be synchronized, and thus there is a problem that the robots must wait and resume their movement. In this paper, we propose a heuristic algorithm that can reduce the total time of the optimal solution obtained by using the previously proposed genetic algorithm. It iteratively desynchronizes the task sequence of two robots and reduces the waiting time. For evaluation, the proposed algorithm is applied to the same work as the previous study. As a result, we can obtain a faster solution having 22.57 s than that of the previous study having 24.081 s. It will be further studied to apply the proposed algorithm to the fruit harvesting.

• 한국경영과학회지
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• 제18권3호
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• pp.151-157
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• 1993

In this paper, we investigate the effects of yield randomness for lot-sizing in a multi-stage production system. The practical importance of incorporating yield randomness into production models has been emphasized by many researchers. Yield randomness, especially in semiconductor manufacturing, poses a mojor challenge for production planning and control. The task becomes even more difficult if the demand for final product is uncertain. An attempt to meet the demand with a higher level of confidence forces one to release more input in the fabrication line. This leads to excessive work-in-process (WIP) inventories which cause jobs to spend unpredictably longer time waiting for the machines. The result is that it is more difficult to meet demand with exceptionally long cycle time and puts further pressure to increase the safety stocks. Due to this spiral effect, it is common to find that the capital tied in inventory is the msot significant factor undermining profitability. We propose a policy to determine the quantity to be processed at each stage of a multi-stage production system in which the yield at each stage may be random and may need rework.

• 대한가정학회지
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• 제38권8호
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• pp.99-110
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• 2000

The purpose of this study was to investigate the differences in traditional baby-delivery practices between young mother and grandmother generations. The subjects were 118 young mothers and 118 their own mothers or mothers-in-law in Tae Gu district. Young mothers had the first baby aged from 2-to 2.5-year-old. The subjects answered the questionnaires on Korean traditional baby-delivery practices developed by the researchers based on literature reviews. The data were analyzed using Frequencies, Percentages, Crosstabs, and t-test. The results of this study were as follows: 1. More grandmothers believed in supernatural being who influenced pregnancy and used to be called as 'grandma Sam Shin', expected to have son, and had charms then young mothers. But less grandmothers had sexual intercourse at the time of ovulation, took physical care, and practiced fetal education than young mothers 2. On the other hand, no generation differences were found in dreaming of foretelling conception(Te Mong), eating a restroative and food to get pregnancy, and washing own's hair or body and avoiding attending a funeral near the time of baby-delivery. 3. Most of young mothers gave birth in hospital with the doctor's heap, whereas most of grandmothers did at their home with the help of the experienced old women. Most of young mothers'husbands were at the waiting room in the hospital, but about half of grandmothers'husbands were at work when their wives grove birth.

• 한국병원경영학회지
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• 제25권1호
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• pp.1-12
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• 2020

Purposes: The aim of this study is to evaluate whether the contents of hospital reservation and reception applications(apps) are qualitatively useful in meeting the needs of medical consumers and improving hospital accessibility and convenience. Methodology: (1) identify consumer needs through social data web mining, (2) describe the status of key contents of mobile apps to improve accessibility and convenience of care, and (3) verify the quality of apps through validated tools Finding: The contents of 'mobile reservation function' and 'waiting time information provision' that can contribute to reduction of delay time of care and efficiency of desk work were supported, but the level of utilization was insufficient. The quality level of the app, including the level of consumers' needs, has shown a wide gap between the apps. Implications: The recent development of mobile apps for hospital accessibility and consumer needs has shown a wide gap in the quality of apps, including information and aesthetic. Therefore, it is necessary to develop apps based on user interface(UI), user experience(UX) based designs that can promote the usefulness and convenience of apps while monitoring needs of consumers continuously.

• 한국시뮬레이션학회논문지
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• 제20권3호
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• pp.29-39
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• 2011

예약시스템은 고객들이 서비스에 효과적으로 접근하는 것을 용이하게 하는 방법으로 의료 등의 서비스 산업에서 많이 사용되고 있다. 예약시스템의 중요성 때문에 서비스 제공 환경 별로 효과적인 예약정책 수립에 대한 연구가 많이 진행되고 있지만 대부분의 연구는 단일 서버, 단일 단계로 구성된 서비스 시스템만을 고려하고 있다. 본 논문은 다수의 서버로 구성된 두 단계 서비스 시스템에서 다양한 예약정책을 평가하여 효과적인 예약정책을 수립하는 것을 목적으로 한다. 2단계의 서버가 개별적으로 고객 예약을 수립하는 환경을 고려하여 본 연구에서는 교차예약정책을 제시하였다. 시뮬레이션 연구를 통하여 기존의 전통적인 예약정책과 비교하여 고객대기시간, 서버의 유휴시간, 예약보다 지연 도착하는 고객의 수 등에서 교차예약정책이 우수한 결과를 제공하는 것을 제시하였다.

• 정보처리학회논문지D
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• 제12D권1호
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• pp.151-158
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• 2005

본 논문에서는 기존의 지도 데이터베이스를 모바일 폰에 사용할 수 있도록 래스터 이미지로 변환시켜 전송할 수 있는 무선 지도의 동적 생성 기법을 제안하였다. 무선 지도의 동적 생성을 위해서 좌표변환, 데이터 압축과 해독 등 클라이언트 모들의 기능을 서버로 이전시키고, 제한된 자인을 가진 모바일 폰에서 JAVA 브라우저를 구동할 수 있게 하였다. 지도의 일반화 작업은 서버에서 수행하도록 하여, 모바일 폰 전용의 지도 데이터베이스가 없어도 무선 전자지도서비스가 가능하도록 구현하였다. 또한 서버에서 지도의 필터링작업을 병행하게 함으로써 한계 이내의 클라이언트 대기시간을 보장하였다. 실험을 목적으로 설계하고 구현한 사용자 인터페이스 상에서 사용자가 원하는 지역 또는 시설물을 찾기 위한 키워드를 입력한 후, 모바일 폰에서 사용 가능한 래스터 전자 지도를 목적한 바와 같이 동적으로 생성할 수 있는 지를 확인하여 제안된 방법의 성능을 검증하였다.