• 한국시뮬레이션학회논문지
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• 제8권4호
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• pp.73-87
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• 1999

Order Review/Release (ORR) System is the linkage between planning system and actual production. Reduction of the waiting time on the machines, work in process and lead time variation may be achieved by adopting ORR strategies. But researchers on the ORR do not agree on the effectiveness of ORR. Some say that the overall system flow time may be increased if ORR is adopted, but others say that ORR can reduce work in process, flow time and variation of flow time. The objective of this research is to clarify under what environments order release strategy is effective. Simulation study was conducted in a hypothetical job shop. The experimental results show that dispatching rule is much more important than ORR is in controlling the shop floor. But the results indicate that ORR can reduce mean shop flow time, average work in process and variation of shop flow time under such environments where utilization level is high and planned order is weekly released to the order pool. And the results also show that the effect of plan smoothing on the ORR is insignificant, which is inconsistent with the results of the previous researches.

• 한국의료질향상학회지
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• 제8권1호
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• pp.74-83
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• 2001

Background : Since a Gamma Knife had been installed on December 1997, 405 patients have been treated until December 1999 at department of neurosurgery of Seoul National University hospital. The authors analyzed results of a work to improve satisfaction of Gamma Knife surgery patients and to reduce hospital length of stay. Methods : To understand main discontent of patients, a pre-survey was performed from October 1998 to December 1999 using a questionnaire. By Analyzing 93 questionnaire received from 234 patients, pain on frame application, explanation before surgery, waiting time before surgery, waiting time before medical procedure were main discontent factor and overall satisfaction ratio was 71.0%. To improve satisfaction ratio, several quality improvement activity works were designed and applied to 123 patients during the period between January 2000 and September 2000. The same questionnaire were analyzed. Works to reduce the patient hospital LOS were devised and applied during the same period. Results : The overall satisfaction ratio of Gamma Knife radiosurgery patients was increased to 83.7%(P=0.10). The main factor to improve satisfaction ratio was to reduce waiting time(P=0.05) and improvement of discomfort during the surgery(P=0.06). The average LOS was reduced from 3.1 to 2.7 days(P=0.003). Conclusion : As a result of quality assurance activities, the overall satisfaction ratio of patients was improved and LOS was reduced. The pain during frame application was remained as a main discontent factor and a further study is required to reduce this pain.

• 한국시뮬레이션학회논문지
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• 제21권4호
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• pp.11-24
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• 2012

이 연구는 상수 공정 시간을 갖는 라인생산시스템에서 CONWIP과 DBR이 각각 max-plus 선형시스템의 특수형태임을 밝히고 max-plus 대수에 기반한 안정대기시간 연구결과를 이용하여 CONWIP와 DBR의 성능을 비교 분석하였다. CONWIP의 경우, 생산시스템 내의 체류시간은 DBR의 경우보다 항상 짧다는 사실이 수학적으로 규명되었고 예제를 통해 계산, 비교되었다. 한편 두 경우에서 모두, 애로공정이후 노드에서의 대기시간은 유한버퍼의 크기와 공정의 순서에 무관함을 확인하였다. CONWIP에서는 시스템 내 평균 대기시간 또는 체류시간이 공정의 순서에 무관하지만, DBR에서는 애로공정이 뒤로 갈수록 감소함을 확인하였다.

• 한국의료질향상학회지
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• 제26권2호
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• pp.66-76
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• 2020

Purpose:Hospitals provide top medical service using exceptional manpower, medical technology, and state-of-the-art equipment, thus raising the standard of customer satisfaction. In addition, their medical service is becoming higher than before. One-stop service is a good way to improve the quality of customer-centered service as a qualitative marketing strategy. This study thus aims to facilitate subsequent research and compare customer satisfaction before and after one-stop service. Methods: The study included 72 patients who received the reserved examination and one-stop service for 20 days from April 23 to May 12, 2014. The surveyed questionnaire data were analyzed using SPSS 18.00. Results: The comparison results of customer satisfaction showed that the satisfaction score was generally high in the areas of kindness of examination staff, the speedy/accuracy of work processing of examination staff, and the kindness of reservation staff. The group before one-stop service showed their dissatisfaction with repeated visits and difficulty of booking a desired day. The group after one-stop service showed dissatisfaction with the long waiting time for examination or same-day treatment. Conclusion: The one-stop service showed good results, but new uncomfortable issues for the customer were revealed as well, which may result in more work of employees. Considering the characteristics of various clinical departments, the author hopes to find an efficient operation plan through the development and improvement of an appropriate one-stop service method.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.422-425
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• 2003

건축공사의 고층화 추세에 따라 반복공정의 수가 증가하고, 마감공사에서의 관련 공종 수가 증가하여 작업 연속성에 대한 계획 및 공사관리가 중요하게 인식되고 있으며, 이러한 마감공사의 효율적 은용을 위해 각 작업을 일정한 리듬으로 반복되도록 함에 따라 공정의 개선을 이루고자 하는 기법이 택트공정관리이다. 그러나 택트공정관리는 세부공정 및 작업구역에 따른 상이한 시공속도와 이로 인한 선행공정의 작업지연 등 비효율적 요소 때문에 적용에 어려움이 있었다. 따라서 본 연구에서는 작업별 소요시간의 동기화(同期化)를 통한 개선효과를 파악하기 위해 기존의 공동주택 창호공사를 대상으로 작업방식의 세부작업단위 및 작업인원 수를 작업시간의 동기적(同期的)연결 및 최소 요구인원 수를 기준으로 조정한 후, 공기단축 효과를 분석하였다.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1723-1727
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• 2005

A generalized fractional diffusion equation (FDE) is presented, which describes the time-evolution of the spatial distribution of a particle performing continuous time random walk (CTRW) on a fractal lattice. For a case corresponding to the CTRW with waiting time distribution that behaves as $\psi(t) \sim (t) ^{-(\alpha+1)}$, the FDE is solved to give analytic expressions for the Green’s function and the mean squared displacement (MSD). In agreement with the previous work of Blumen et al. [Phys. Rev. Lett. 1984, 53, 1301], the time-dependence of MSD is found to be given as < $r^2(t)$ > ~ $t ^{2\alpha/dw}$, where $d_w$ is the walk dimension of the given fractal. A Monte-Carlo simulation is also performed to evaluate the range of applicability of the proposed FDE.

• 대한인간공학회지
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• 제30권3호
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• pp.419-426
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• 2011

Objective: The objective of this study was to evaluate a work of guards, using an ergonomic method(work analysis and posture analysis). Background: Most studies about guards were conducted in the field of medical, problems of shift, and the physical problems of old workers and social problems. But, guards consist of vulnerability group so it needs an ergonomic research in musculoskeletal disorders. Method: A head of an ergonomic estimation was work analysis(determination of combined task, work tool, work time and frequency of combined task) and posture analysis(upper body and lower body) of workers based on the video. Results: The result showed that combined task of guards was classification of patrolling, security, cleaning and waiting. The security indicated the highest ratio in the work time of combined tasks. The results of posture analysis for guards indicated high value in neutral. But, lower arm indicated high value in bending(left: 59%, right: 50%). Conclusion: The results of ergonomic methods indicated that guards' physical work load was not high during work, but comfortable work environment would be required for old guards. Application: If an ergonomic rule can be integrated into existing work environments, the risk of occupational injuries and stress will be reduced.

• 대한인간공학회지
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• 제30권3호
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• pp.427-435
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• 2011

Objective: The objective of this study was to evaluate a work of building cleaners using the ergonomic methods. Background: Previous studies about cleaning worker describe typical physical demands of this work. They found that the most significant risk factors associated with the physical work of cleaners are static loads and repetitive movements and high output of force. Method: A head of ergonomics estimation was work analysis(define of combined task, work tool, work time and frequency of combined task) and posture analysis of worker. Results: The results showed that combined task of building cleaners was classification sweeping, mopping(wet), mopping(oil), moving barrels/carts, dumping trash bags, scrubbing, arrangement of cleaning tool, arrangement of circumferential, moving of cleaning tool, and waiting. The work time of combined task such as mopping(wet) and scrubbing indicated high ratio. The posture analysis of building cleaners indicated high value in bending of the head, lower arm, and hands. Conclusion: The findings appear to indicate that building cleaner were related to high risk of work-related musculoskeletal disorders. So, building cleaner would be required an interventional strategy, improvement of cleaning tools and working environment. Application: If ergonomics rule can be integrated into existing cleaning tools and work environments, the risk of occupational injuries will be reduced.

• 산업경영시스템학회지
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• 제2권2호
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• pp.83-91
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• 1979

The purpose of this study is to analyze the direct relationship between doctors and number of patients to be treated by applying many kinds of I E's techniques. Generally, doctors in this research work both at OPD & IPD. Under the hospital manegement system that they are applying in, doctor's daily working schedules are instable because the numbers of OPD patients very daily. Therefore, the amount of time they spend for inward Patients are variable too. So the numbers of Patients have great influence to the whole hospital system management. In the first place, the author researched and analyzed a QC of administrative system. Tn the second place, the author carried out Work Sampling with a view for understanding quantity of a doctor's operation. The author suppose this research and analysis is one approach for improving systematic lay-out planning at outpatient waiting room where has many problems to be solved and suggest several process for improvement.

• 산업경영시스템학회지
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• 제2권2호
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• pp.63-81
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• 1979

The purpose of this study is to analyze the direct relationship between doctors and number of patients to be treated by applying many kinds of I E's techniques. Generally, doctors in this research work both at OPD & IPD. Under the hospital manegement system that they are applying in, doctor's daily working schedules are instable because the numbers of OPD patients very daily. Therefore, the amount of time they spend for inward Patients are variable too. So the numbers of Patients have great influence to the whole hospital system management. In the first place, the author researched and analyzed a QC of administrative system. Tn the second place, the author carried out Work Sampling with a view for understanding quantity of a doctor's operation. The author suppose this research and analysis is one approach for improving systematic lay-out planning at outpatient waiting room where has many problems to be solved and suggest several process for improvement.