• 대한산업공학회지
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• 제14권2호
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• pp.81-90
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• 1988

This paper is concerned with warranty cost models for a product with two types of failure ; type 1 failures corrected by minimal repair and type 2 failures removed only by replacement. Two warranty policies involving an initial free service period followed by a pro-rata period are considered ; the difference is whether the warranty is renewed or not when type 2 failure occures during its free service period. Expected warranty costs under the two policies are obtained, and their behaviors are examined for the case where type 1 and 2 failure distributions are Weibull and exponential, respectively.

• Clinics in Shoulder and Elbow
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• 제17권3호
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• pp.120-126
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• 2014

Background: To compare the treatment of the proximal humerus fracture using a Polarus nail or Philos plate, we aimed to analyze the functional recovery and the factors affecting the selection between the two types of surgery. Methods: The study included 107 patients with proximal humerus fracture who underwent surgery at our institution. Of these patients, 67 underwent surgery with Polarus nails (G1) and 40 with Philos plates (G2). In G1, the cases of two- and three-part fractures were 60 and 7 cases, in G2, the cases of two-, three-, and four-part fractures were 28, 10, and 2 cases, respectively. The average age was 61 years old, and the average follow-up period was 32.5 months. We compared radiological results, the functional recovery retrospectively. Results: The radiological union time was 6.8 weeks and 8.7 weeks on average in G1 and G2 (p < 0.05). At the one-year follow-up period, these were visual analogue scale (VAS) 1.355, forward flexion (FF) 130.968, external rotation (ER) 50.161, internal rotation (IR) L2 in G1, and VAS 0.781, FF 135.806 ER 51.25, IR L1 in G2, respectively, showing no significant differences between the two groups (p > 0.05). Similar observations were made at the final follow-up. In terms of functional recovery, no significant differences were seen at the one-year or at the final follow-up period (p > 0.05). Conclusions: For the surgical treatment of proximal humeral fracture, the selection of the type of surgery is affected by the fracture pattern. However, both methods give satisfactory outcomes and do not show significant differences in the functional outcome after the surgery.

• 디지털융복합연구
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• 제16권7호
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• pp.19-26
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• 2018

본 연구의 목적은 첫째, 산업재해근로자의 재활서비스 이용실태와 서비스 이용에 대한 욕구가 시간에 따라 어떻게 변하는지 분석하고자 한다. 둘째, 어떤 요인들이 재활서비스 이용 욕구 변화에 영향을 주는지 분석하고 그 결과를 통해 산재근로자를 위한 정책 개선 방향을 제시하는 것이다. 산재보험패널 1~3차 자료 5,004 관측치를 대상으로 STATA를 이용하여 패널회귀분석을 실시하였다. 횡단분석에서 재활서비스 필요정도에 미치는 영향 요인은 연령, 교육연수, 현재 직무수행능력, 지역사회서비스 경험, 재취업, 미취업으로 나타났다. 시간의 변화에 따른 재활서비스 필요정도에 유의미한 영향 요인은 연령, 교육연수, 미취업, 현재 직무수행능력, 지역사회서비스 이용 경험으로 앞의 횡단면 분석과 다르게 나타났다. 따라서 산재근로자의 연령, 학력, 경제활동 형태 등에 따라 재활서비스 내용과 그 필요 정도가 시간에 따라 변한다는 점에서 요양기간 종료 후 초기 개입 내용을 시기별로 점검하고 조정하는 것이 필요할 것이다.

• 보건의료산업학회지
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• 제5권2호
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• pp.35-51
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• 2011

The purpose of this study is to examine relations between the job stress of radiologists, who are serving at secondary medical institutions, and their intent of separation, providing basic information necessary to earlier prevent the separation, improve the quality of radiologists and ensure a more effective personnel management of the professionals. For the purpose, this researcher conducted a structured questionnaire survey of 221 radiologists from Nov 1 to 30, 2010 who were serving at secondary medical institutions located in Busan. Findings of the study can be summarized as follows. 1) The surveyed radiologists were scored 2.82 points in average in terms of job stress. This indicates that they are suffering from job stress higher than moderate. 2) The subjects were significantly different from each other in job stress according to their age, total service period, department where they were serving, satisfaction with their hospital and satisfaction with the foresaid department. 3) The subjects were scored 2.59 points in average in terms of the intent of separation. This indicates that the surveyed radiologists are not so willing to change their job. 4) Those radiologists were significantly different from each other in the intent of separation according to their age, marital status, educational background, average monthly income, total service period, the period of service at a department where they belonged now, position, satisfaction with their hospital and satisfaction with the foresaid department. 5) There were significant correlations between the subjects' job stress and intent of separation.

• 산업공학
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• 제17권spc호
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• pp.62-68
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• 2004

HAPS (High Altitude Platform Station) which is defined as a station located on an object at an altitude of 20 to 50 km and at a specified, nominal, fixed point relative to the earth is a promising technology capable of providing broadband multimedia services. In this study, economical aspects of HAPS service are analyzed by estimating the revenue and costs incurred by the service. To evaluate the profitability of HAPS service, the number of subscribers is estimated and then the net present value (NPV), payback period, and the rate of return on investment (ROI) are calculated under various scenarios.

• 산업경영시스템학회지
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• 제19권37호
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• pp.31-40
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• 1996

The amount of safety stock is decided from various information such as the forecasted demand, the lead time, the size of the order quantity and the desired service level. There are two cases to consider the problem of setting safety stock when both the demand in a period and the lead time are characterized as random variables: the first case is the parameters of the demand and lead time distributions are known, the second case is they are unknown and must be estimated. The objective of this study is to present the procedure for setting safety stocks in the case the parameters of the demand and lead time distributions are unknown and must be estimated. In this study, a simple exponential smoothing model is used. to generate the estimates of demand in each period and a discrete distribution of the lead time is developed from historical data, and the optimal service level is used which determined to consider both of a backorder and lost sale.

• 보건의료산업학회지
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• 제8권2호
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• pp.1-10
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• 2014

This study examined nonpatient revenues of university hospitals in korea. The data source for this study was 22 university hospitals over the period 2010-2012. In this study, patient revenues, patient expenses, operating profit, nonpatient revenues, total revenues, operating margin, normal profit to gross revenues, ratio of the nonpatient revenues in the total revenues were analysed by the annual and three-year average. The analysis of nonpatient revenue differences by hospital type, bed size, location, management performance was performed by T-test and oneway ANOVA. The results were as follows. First, nonpatient revenues of university hospitals were increased during the period 2010-2012. Second, nonpatient revenues according to hospital type, bed size, location in the university hospitals had significant difference. Third, hospital type was significantly associated with normal profit to gross revenues which was profitability index about nonpatient revenues. Based on these results, this study suggests implications to diversify for management performance in hospitals.

• 대한안전경영과학회지
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• 제11권1호
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• pp.205-211
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• 2009

In reality, distribution planning for a supply chain is established using a certain probabilistic distribution estimated by forecasting. However, in general, the demands used for an actual distribution planning are of deterministic value, a single value for each of periods. Because of this reason the final result of a planning has to be a single value for each period. Unfortunately, it is very difficult to estimate a single value due to the inherent uncertainty in the probabilistic distribution of customer demand. The issue addressed in this paper is the selection of single demand value among of the distributed demand estimations for a period to be used in the distribution planning. This paper proposes an efficient demand selection scheme for minimizing total inventory costs while satisfying target service level under the various experimental conditions.

• 대한수의학회지
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• 제49권3호
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• pp.201-205
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• 2009

In this study, we evaluated the stability and potency of live attenuated rinderpest vaccines of lapinized-avianized tissue culture strain origin, which had been produced annually from 2005 to 2008. When immune responses to the vaccines were evaluated using two Holstein calves weighing 100~150 kg, neutralizing antibody titer of 1 : 16 was induced at 21 days post vaccination. When calves were also inoculated with vaccines lots that had been stored for 39 months at ${4^{\circ}C}$, same level of antibody titer was observed. Using the virus titer test, we found that all batches of the vaccine that had been kept for 3, 10, 15, 22, 27, 34, 39, and 45 months showed no significant loss of titers, and fulfilled the requirement necessary ($\geq$ 3 $logTCID_50$) to be used as the national rinderpest vaccine reserve in Korea. In this study, we demonstrated that stability and potency of the rinderpest vaccines were maintained over three years when kept at ${4^{\circ}C}$ storage. This indicates that it maybe feasible to extend the expiration period of this vaccine from one year to three years.

• 디지털융복합연구
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• 제8권2호
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• pp.13-28
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• 2010

본 논문의 목적은 서비스 산업의 정보통신기술 이용 현황을 살펴보고, 산업별 생산성 분석을 통해 서비스 산업의 질적 성장을 위한 방안을 모색하는 것이다. 이를 위해 전체 자본스톡 중 정보통신기술 자본스톡의 비중과 노동자 인당 정보통신기술 투자액을 이용하여 각 산업별 정보통신기술 이용 현황을 알아보고, 성장회계 방식을 이용하여 이들 산업별로 총요소생산성의 시기별 분석과 외환위기동안의 생산성의 변화를 분석하였다. 그 결과는 다음과 같이 정리할 수 있다. 첫째, 서비스산업의 전체 자본스톡에서 정보통신기술 자본스톡이 차지하는 비중이 2000년 이후 줄어들었으나 서비스산업 내 노동자 일인당 정보통신기술 투자액이 지속적으로 증가하였다. 또한 미국 등 선진국과 비교해 보았을 때, 국내 서비스 산업의 정보통신기술 이용이 상대적으로 낮은 것으로 나타났다. 둘째, 산업별 생산성 분석 결과, 생산성 향상은 산업에 따라 조금씩 다르게 나타났으나. 대부분의 산업들이 외환위기 동안 생산성이 감소하다 외환위기가 지난 후 생산성을 빠르게 회복하고 2003 년 이후부터는 안정한 형태를 보였다. 셋째 정보통신기술을 더 많이 이용하는 산업일수록 생산성 증가가 크고, 외환위기 등 경제 외부적인 변화에서도 더 안정된 모습을 보였다. 이는 '외환위기 이후' 국내 서비스 산업에서 정보통신기술 이용이 산업의 생산성에 긍정적인 영향을 미치고 있는 것으로 해석할 수 있다.