• Management Science and Financial Engineering
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• 제16권3호
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• pp.49-70
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• 2010

Customer population management models can be classified into three categories: the first category includes the models that analyze the customer population at cohort level; the second one deals with the customer population at aggregate level; the third one has interest in the interactions among the customer populations in the competitive market. Our study proposes a model that can analyze the dynamics of customer population in consumer-durables market at aggregate level. The dynamics of customer population includes the retention curves from the purchase or at a specific duration time, the duration time expectancy at a specific duration time, and customer population growth or decline including net replacement rate, intrinsic rate of increase, and the generation time of customer population. For this study, we adopt mathematical ecology models, redefine them, and restructure interdisciplinary models to analyze the dynamics of customer population at aggregate level. We use the data of previous research on dynamic customer population management at cohort level to compare its results with those of ours and to demonstrate the useful analytical effects which the precious research cannot provide for marketers.

• International Journal of Reliability and Applications
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• 제12권2호
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• pp.131-143
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• 2011

In most of literatures of age replacement policy, the authors consider the case that a new item starts operating at time zero and is to be replaced by new one at time T. It is, however, often to purchase used items because of the limited budget. In this paper, we consider age replacement policy of a used item whose age is $t_0$. The mathematical formulas of the expected cost rate per unit time are derived for both infinite-horizon case and finite-horizon case. For each case, we show that the optimal replacement age exists and is finite and investigate the effect of the age of the used item.

• 한국정밀공학회지
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• 제20권9호
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• pp.92-99
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• 2003

Quality inspection of textile products is an important problem for fabric manufacturers. This paper presents an automatic vision-based system for quality control of web textile fabrics. Typical web material is 1-3m wide and is driven with speeds ranging from 20m/min to 200m/min. At the present, the quality assessment procedures are performed manually by expert. But worker can not detect more than 60％ of the present defect and inspect the fabric if moving faster than 30m/min. To increase the overall quality and homogeneity of textile, an automated visual inspection system is needed fur the productivity. However, the existing inspection system are too expensive to purchase for small companies. In this paper, the proposed PC based real-time inspection algorithm gives low cost textile inspection system, high detection rate with good accuracy and low rate of false alarms. The method shows good results in the detection of several types of fabric defects.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.163-164
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• 2018

Every construction company should consider the apartment price when building apartment houses because the sales price has a great impact on the rate of apartment sales. Here, the average apartment price and characteristics of an apartment complex are factors that determine the sales price. However, the existing apartment pricing method fails to properly reflect the weight of each factor. Therefore, the study investigates factors that impact the apartment price and importance of each factor. It examines the apartment pricing method taking into account of the weight.

• International Journal of Reliability and Applications
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• 제10권1호
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• pp.33-42
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• 2009

In most of literatures of age replacement policy, the authors consider the case that a new item starts operating at time zero and is to be replaced by new one at time T. It is, however, often to purchase used items because of the limited budget. In this paper, we consider age replacement policy of a used item whose age is $t_0$. The mathematical formulas of the expected cost rate per unit time are derived for both infinite-horizon case and finite-horizon case. For each case, we show that the optimal replacement age exists and is finite and investigate the effect of the age of the used item.

• 신재생에너지
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• 제17권2호
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• pp.1-8
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• 2021

We estimated the price range of electricity transactions under the prosumer system, considering the spread of renewable energy and the prospect of introducing a surplus power trading system between power consumers in Korea. The range (min/max) of power transaction prices was estimated by prosumers and consumers who could purchase electricity from utilities if needed. It is assumed that utilities purchased electricity from prosumers and consumers under a Time-of-Use (TOU) rate, trading at a monthly price. The range of available transaction prices according to the amount of power purchased from utilities and the amount of transaction power was also estimated. The price range that can be traded is expected to vary depending on variables such as the TOU rate, purchased and surplus power, levelized cost of electricity, etc.

• 한국콘텐츠학회논문지
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• 제8권12호
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• pp.322-333
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• 2008

본 연구는 500병상 규모의 병원에서 PACS 도입 시 준비 작업 및 제안서에 포함 되어야 할 항목과 의료장비 도입 전 검토조서의 제시로 장비 도입 전 수익성 및 운용 부서에서 계획서에 제시 된 예상수익을 근거로 하여 장비의 이용도와 수익성을 조사하여 고가의료장비의 구입 원가, 이용도 등을 분석하였다. 연구대상 병원에서 PACS 도입 시 수가로 인하여 수익이 발생되는 것으로 나타났고, 의료장비 구입 방법은 임차 방식으로 기간은 3년에서 5년으로 나타났으며, 수익은 2년 정도이면 투자비용을 상회하여 수익이 발생 될 것으로 예상되었다. 병원의 PACS를 도입 운영에 있어서 의료장비 구매 금액은 영상의학과의 운영에서 발생되는 수익을 근거로 할 때 투자비용은 약 1.9년 정도이면 투자금액을 회수 할 수 있을 것으로 예상되었으며, 영상의학과의 재촬영 검사의 감소와 필름 및 현상 정착액을 구입하지 않아 운영비를 절감할 수 있는 것으로 나타났다. 또한, 실질적인 수익 증가 외에도 병원 마케팅 차원에서 병원의 위상 향상, 직원들의 업무절감 등에 의한 업무 환경개선 또는 업무 스트레스 감소 등 병원 직원의 업무 만족도 증가로 인한 병원의 서비스 향상에도 기여하는 것으로 나타났다. 이와 같은 결과 병원규모에서 PACS 도입 시 의료장비의 예상 수익을 작성하고 진료업무의 기여도 및 구매 후에도 수익 등을 비교 분석하여 의료장비 도입 전 제안서 작성과 도입 후 효율적인 장비 운영 계획을 수립해야 할 것으로 사료되었다.

• 한국식품조리과학회지
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• 제15권2호
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• pp.133-145
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• 1999

The schools in the survey consisted of 61 schools where foodservice was managed by themselves and 49 schools where it was done cooperatively. According to the style managed, the urban style was 42 schools, the rural style was 46, and the island style was 22. With regard to the amount for each student that parents have to pay. it was 745 won at schools managed by themselves and 616 won at schools managed cooperatively. The budgeted amount was 75 won at schools managed by themselves and 97 won at schools managed cooperatively. The result showed that parents at schools managed for themselves paid much more for the cost of food and management. The mean area of kitchens was 31 pyong (102 sq. meters) in environment of cooking utilities, and management was done wherever they were needed. The budgeted amount was supplied from the Educational Office and parents. In the situation of utilities and instruments for cooking, the places to wash hands and flush toilets, which were regarded as sanitary facilities were insufficient. The rates of containing measuring instruments and thermometers for cooking were also insufficient. The list to be considered in the management of menu was concentrated on raising acceptance of students served, based on the order of the tastes of students served, the quantity of the cost, nutrition needed, and then facilities. The replies that leftover food was thrown away after meals were numerous and the rate of leftover food was reflected on the menu. In purchase and management, the rate of food needed to be purchased was calculated through experience. A private contract was chosen to purchase food. The frequency of purchasing food was usually once a day, which would nutritists examined food, concentrating on the order of quality, number, and price. In the management of operation, a schedule for making food was seldom formed, referring to it only at the time needed. All the food was made in a day but some special foods were made the day before they would be required. It shows the situation was thought to be the most important. Guidance for sanitation was carried out once a month and the content of the guidance was about the sanitary treatment of food. With regard to degree of satisfaction with the management of meal service, all the dietitian at schools managed for themselves and cooperatively were somewhat satisfied with all the questions about the budgeted amount of food, and management, the management of purchase, operation, and sanitation. However, they were not satisfied with the environment of facilities.

• Journal of Biosystems Engineering
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• 제39권4호
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• pp.261-266
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• 2014

Purpose: This study was conducted to serve as a basis for strengthening policy support and R&D to improve the domestic and international competitiveness of domestic agricultural machinery. Levels of satisfaction among farmers and service engineers were analyzed regarding the current quality of agricultural machinery and the primary consumers' propensity for replacement purchases. Methods: A survey was carried out targeting farmers in over 150 townships and 300 villages in South Korea who collectively used 711 tractors, 286 rice transplanters, and 221 combine harvesters. Furthermore, agricultural machinery service engineers from 20 different after-services were surveyed regarding the quality of main components in domestic agricultural machinery versus those in imported agricultural machinery. Results: The farmers' overall quality satisfaction ratings for tractors, rice transplanters, and combine harvesters ranged from 57.1% to 62.6% in consideration of operating performance, failure rate, and durability. Compared with imports, satisfaction ratings for domestic agricultural machinery were 19.1%p to 38.1%p lower for quality. Regarding engines, transmissions, hydraulics, planters, reapers, threshers, and electrical components, only 5.3% to 25.0% of service engineers indicated that domestic agricultural machinery was higher in quality compared with imports. By contrast, 33.3% to 78.9% of those surveyed indicated that domestic components were lower in quality compared with imports. Intent to purchase replacement agricultural machinery at the end of their respective products' lifecycles was indicated that they planned to purchase imported tractors, rice transplanters, and combine harvesters comprised 25.2%, 46.9%, and 43.9%, respectively. This clearly shows that a very high percentage of farmers were satisfied, particularly for transplanters and combine harvesters. Conclusions: The level of desire for purchasing imported agricultural machinery was very high among those who expressed intent to purchase replacement machinery. Therefore, strong policy support and R&D for domestic agricultural machinery is critical for improving competitiveness on the domestic and foreign markets.

• 통상정보연구
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• 제18권2호
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• pp.27-51
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• 2016

본 연구의 목적은 우리나라 B2C 전자상거래 촉진요인과 온라인쇼핑시장 및 해외직접구매와의 상관관계를 분석함으로써 물류기업들의 물류운영전략 수립에 시사점을 제공하는데 있다. 본 연구는 문헌연구를 통하여 B2C 전자상거래 촉진요인을 도출하고, 전자상거래 촉진요인과 국내 온라인쇼핑 및 해외직접구매와의 인과관계를 실증 분석함으로써 B2C 전자상거래 시대 우리나라 택배서비스기업들의 과제 및 성공적 물류운영전략을 제안하고 있다. 본 연구에서는 B2C 전자상거래 촉진요인들이 국내 온라인쇼핑거래액 및 해외직접수입 실적에 미치는 영향을 파악하기 위해 두 가지 ARDL 모형을 설정하였다. 모형의 분석결과, 신용카드 이용건수, 가구당 처분가능소득, 환율, 실질GDP, 정보통신 부문 설비투자, 초고속인터넷가입자수, 인터넷 프로토콜 IPV4 보유수, 15세 이상 인구 등의 변수가 종속변수에 영향을 미치는 것으로 나타났다. 향후 온라인 모바일 기술 및 국민들의 경제수준이 고양됨에 따라 B2C 전자상거래 기업 및 물류기업들은 최적의 택배 물류서비스 수행을 위한 고도의 전략적 접근이 필요한 시점이다.