• 산업공학
• /
• 제13권3호
• /
• pp.378-387
• /
• 2000

As the globalization of manufacturing companies continues, the scope of dependence between these companies and distributors, and other suppliers are growing very rapidly since no one company manufactures or distributes the whole product by themselves. And, the need to increase the efficiency of the whole supply chain is increasing. This paper deals with a multi-plant lot-sizing problem(MPLSP) which happens in a decentralized manufacturing system of a supply chain. In this study, we assume that the whole supply chain is driven by a single source of independent demand and many levels of dependent demands among manufacturing systems in the supply chain. We consider setup cost, transportation cost and time, and inventory holding cost as a decision factor in the MPLSP. The MPLSP is decomposed into two sub-problems: a planning problem of the whole supply chain and a lot-sizing problem of each manufacturing system. The supply chain planning problem becomes a pure linear programming problem and a Generalized Goal Decomposition method is used to solve the problem. Its result is used as a goal of the lot-sizing problem. The lot-sizing problem is solved using the CPLEX package, and then the coefficients of the planning problem are updated reflecting the lot-sizing solution. This procedure is repeated until termination criteria are met. The whole solution process is similar to Lagrangian relaxation method in the sense that the solutions are approaching the optimum in a recursive manner. Through experiments, the proposed closed-loop hierarchical planning and traditional hierarchical planning are compared to optimal solution, and it is shown that the proposed method is a very viable alternative for solving production planning problems of decentralized manufacturing systems and in other areas.

• 한국의료질향상학회지
• /
• 제7권2호
• /
• pp.244-261
• /
• 2000

Background : In order to cope with changes in the management environment at hospitals, increased interests are drawn in patient foodservice system on Continuous Quality Improvement Activity as the method of approaching a quality food service and effective management. Thus, as a part of this activity, this study was conducted to evaluate job flow improvement that was already performed and the results of that process at the dietetic department of a university hospital, focusing on improving management. Method : On February 15 of 1998. the dietetic department formed a job flow-improvement to decide on the priority of job flow improvement, and prepared specific action strategies and schedule of the priority: after a 5 month process period, job improvement achieved on June 15. 1998. Also, economic achievement of the task was evaluated through labor productivity analysis and cost-benefit analysis. Results : The patient food service system which was managed decentralized at the present hospital was centralized, some steps of the food service process were integrated, and quality of patient food was improved. Also, as a solution of the problems expected when conducting job flow improvement was made on food service equipments and utensils. The result of evaluating the job flow improvement that labor productivity improved by 18.2% compared to before the improvement and the result of the analysis of cost-benefit showed that Benefit-Cost (B/C) ratio was 2.22. showing financial merit on the investment. Conclusions : Continuous Quality Improvement Activity needs to be initiated and conducted in the future in various areas of hospital foodservice system in order to actively adopt to ever changing hospital management environment. In order to achieve this goal, many researches and more efforts need to be put in by people in charge of hospital food service management, and interests and support are needed from hospital policy makers.

• 한국정보과학회논문지:정보통신
• /
• 제32권5호
• /
• pp.551-560
• /
• 2005

이동시 발생하는 시그널링 메시지의 양을 줄이기 위한 방법으로 지역성을 고려한 계층적 이동성 제공 방식인 HMIPv6(Hierarchical Mobile IPv6)가 제안되었다. 이동 노드가 방문 링크로 이동하면 링크 사용을 위한 인증 절차를 먼저 수행해야한다. 이를 위해 무선 랜 및 Cellular 망을 중심으로 AAA(Authentication, Authorization and Account) 인증 서비스 도입이 진행되고 있다. 그러나 AAA 인증 서비스는 지역화 된 이동성 제공을 위한 최적화된 시그널링 교환을 제공하지 않는다 이는 실시간 응용을 필요로 하는 세션을 가진 경우 이동 노드에 대한 서비스 지연을 초래할 수도 있다. 본 논문에서는 지역 이동시 인증 과정을 최적화 할 수 있는 인증 위덤 방식을 기존의 HMIPv6 구조에 통합함으로써 인증 발생 시 시그널링의 양을 최소화 하고 서비스 지연 시간을 줄일 수 있는 방법을 제안한다. 계층적 인증 통합 모델을 제안하며 제안된 모델에 대해 이동 특성, 트래픽 특성, 도메인 크기 등에 따르는 인증 비용을 분석하고 기존의 방식과 비교하였는데 평균 $33.6\%$의 비용 절감 효과를 얻을 수 있었다.

• 한국언론정보학보
• /
• 제69권
• /
• pp.170-194
• /
• 2015

신제도주의는 1970년대 이후 정치, 경제, 사회현상에 대하여 제도를 중심으로 보다 정확한 진단과 해법을 추구하는 연구경향을 통칭한다. 공동체에게 좋은 미디어란 무엇이고 어떻게 작동되어야 하는가는 미디어 제도의 설계와 제도 개선에 대한 문제적 성격을 지닌다. 미디어 제도 설계와 제도 개선 문제에 대하여 보다 높은 설명력에 대한 요구에 부응하고 해결방안을 제시할 수 있는 접근 틀이 필요하다. 이러한 배경에서 이 연구는 신제도주의 접근 틀을 통해 미디어 제도에 대한 보다 높은 설명력을 추구하고 이론화를 위한 활용방안을 탐색하였다. 주요 결과로 첫째 신제도주의 접근 틀은 미디어 정책 법제, 미디어조직 연구 분야에 보다 잘 활용될 수 있다. 둘째, 미디어정책 법제 연구와 미디어 조직연구에서 다룰 주요 연구문제와 연구방법을 제시하였다. 이 연구는 미디어 제도에 대하여 보다 체계적이고 통합적인 하나의 연구 방법으로서 신제도주의 접근법의 활용방안을 제시하였다는 점에서 의의를 갖는다. 미디어 제도를 보다 잘 설명할 수 있는 접근법으로 향후 다양한 미디어 제도 연구 분야에 활용될 수 있기를 기대한다.

• 대한수사과학회지
• /
• 제1권1호
• /
• pp.72-87
• /
• 2006

Accidents and terrorist acts that utilize explosives have a great influence on society and thus require a prompt investigation for the arrest of the culprit. However, such investigations are often met with difficulties due to the vastness of the crime scene, restrictions on approaching the scene, fragility of the evidence, complexity of investigation, and the lack of expertise. In spite of such facts, scientific investigation regarding explosives have not been widely studied in Korea. Therefore, the focus of this research primarily concerns the effective scientific investigation methods in cases of accidents that involve chemical explosives. Although the a systematic investigation method is at the heart of scientific investigation in cases of explosive accidents, it is only at its rudimentary stage. Therefore, in this research, a systematic investigation method is put forth for the 'scene investigation, the documentation of the scene, and the collection and processing of evidence. Further, I have set forth a 'scene investigation check list' the ensure a thorough scene investigation and to promote an exhaustive evidence collection that would guarantee the admissibility of such evidence in court. The above efforts were aimed at simplifying the currently complicated investigation system. 1) In the future, a guidebook that can be generally applied to accidents involving explosives in Korea ught to be produced, a continual systematic education and integrated training excises for investigators ought to be established, laws that require additives in explosives ought to be instituted so that the type, components, and source of explosives can be identified, and lastly, a database that contain information on former explosion accidents, trends, and techniques of criminal activities that involve explosion accidents should be compiled.

• Journal of Electrical Engineering and Technology
• /
• 제13권2호
• /
• pp.648-658
• /
• 2018

Regarding the fact that wind power forecast accuracy is gradually improved as time is approaching, this paper proposes a two-stage rolling dispatch approach based on model predictive control (MPC), which contains an intra-day rolling optimal scheme and a real-time rolling base point tracing scheme. The scheduled output of the intra-day rolling scheme is set as the reference output, and the real-time rolling scheme is based on MPC which includes the leading rolling optimization and lagging feedback correction strategy. On the basis of the latest measured thermal unit output feedback, the closed-loop optimization is formed to correct the power deviation timely, making the unit output smoother, thus reducing the costs of power adjustment and promoting wind power accommodation. We adopt chance constraint to describe forecasts uncertainty. Then for reflecting the increasing prediction precision as well as the power dispatcher's rising expected satisfaction degree with reliable system operation, we set the confidence level of reserve constraints at different timescales as the incremental vector. The expectation of up/down reserve shortage is proposed to assess the adequacy of the upward/downward reserve. The studies executed on the modified IEEE RTS system demonstrate the effectiveness of the proposed approach.

• 대한지구과학교육학회지
• /
• 제13권3호
• /
• pp.253-269
• /
• 2020

이 연구는 시대적 배경으로 통합성을 강조하고 과학적 소양 함양을 목적으로 하는 과학교육의 효과적인 목표 달성을 위해 과학수업에서 관찰 가능한 세계관 기반 과학교육과 지속가능발전교육을 접목한 프로그램을 개발하고 이를 실제 고등학교 수업에 적용하여 분석하였다. 실제 고등학생에게 프로그램을 적용한 결과 학생들은 스스로 자신의 가치관을 파악하여 다양한 가치를 고려하고 의사결정하는 과정에서 생태주의의 세계관으로 전환이 일어난 것을 볼 수 있었다. 프로그램 적용과정에서 다양하게 나타나는 각 교과 내용과 교사 세계관의 불일치로 인한 학생들의 가치 충돌로 자신이 가지고 있는 세계관을 파악하고 수업 과정에서 다양한 측면의 가치에 접근하는 과정 중에 학생들의 세계관이 갈등을 일으키고 있는 것이 나타났다. 개인의 가치관 영역에서 세계관은 과학교육에서 확대 적용하여야 하며 교사 및 교과 내용의 세계관에 대한 이해도 필요하다. 이 연구를 통해 과학교육에서 세계관으로 대표되는 개인의 가치관 영역의 접근이 학생의 근본적인 변화에 도움이 되길 기대한다.

• Journal of Microbiology and Biotechnology
• /
• 제34권6호
• /
• pp.1229-1238
• /
• 2024

This study aimed to develop and assess a chitosan biomedical antibacterial gel ZincOxide-GrapheneOxide/Chitosan/β-Glycerophosphate (ZnO-GO/CS/β-GP) loaded with nano-zinc oxide (ZnO) and graphene oxide (GO), known for its potent antibacterial properties, biocompatibility, and sustained drug release. ZnO nanoparticles (ZnO-NPs) were modified and integrated with GO sheets to create 1% and 3% ZnO-GO/CS/β-GP thermo-sensitive hydrogels based on ZnO-GO to Chitosan (CS) mass ratio. Gelation time, pH, structural changes, and microscopic morphology were evaluated. The hydrogel's antibacterial efficacy against Porphyromonas gingivalis, biofilm biomass, and metabolic activity was examined alongside its impact (MC3T3-e1). The findings of this study revealed that both hydrogel formulations exhibited temperature sensitivity, maintaining a neutral pH. The ZnO-GO/CS/β-GP formulation effectively inhibited P. gingivalis bacterial activity and biofilm formation, with a 3% ZnO-GO/CS/β-GP antibacterial rate approaching 100%. MC3T3-e1 cells displayed good biocompatibility when cultured in the hydrogel extract.The ZnO-GO/CS/β-GP thermo-sensitive hydrogel demonstrates favorable physical and chemical properties, effectively preventing P. gingivalis biofilm formation. It exhibits promising biocompatibility, suggesting its potential as an adjuvant therapy for managing and preventing peri-implantitis, subject to further clinical investigations.

• 대한인간공학회지
• /
• 제31권1호
• /
• pp.93-100
• /
• 2012

Objective: This study is to review the current state of services offered to pharmacy users, and develop a service design converging a prescription service and a smart phone application service in order to enhance patients' experience at pharmacies and home. Background: Under the new medical system; separation of prescribing and dispensing drugs, a doctor writes a prescription to their patients and patients have their prescription filled at the pharmacy. As the number of flue, allergy and atopy patients has increased, waiting lines have been longer at pharmacies. Besides, the current medical service system lacks of providing proper information on prescribed pills to patients. There are already services offered during waiting times such as offering free drinks, magazines or suggesting general drugs which you can buy without prescription, however they neither cover the current medical service's shorts nor shorten the waiting time. Method: I researched objective and perceived waiting times reduction methods, the current service status at pharmacies, and the government's policy direction in a medical service. Also, I observed a patient's journey from the hospital to pharmacy and then home. I examined the circumstance at pharmacies, patients' behaviors and their thoughts during their journey, and extracted three main goals to design a service in order to help patients have positive perception during the waiting time; (1) to reduce the perceived time by the way of visualizing time and offering readings about what patients consider necessary, (2) to educate patients what they are into and how to get through, (3) to establish trust among patients, doctors and pharmacists. Based on three goals, I designed a structure and a wireframe for a new service application of smart phones. Results: With a new service design for pharmacy users, users can track their medical record and visit the information about their current medical treatments anytime. Also the service helps patients build reliable relationships with doctors and pharmacists. Conclusion: Experience is not just an activity but series of multiple activities. The serving range of a medical service should not be determined by stakeholders but user's holistic experience. By approaching a service design with a holistic vision, it can enrich not only a temporary experience but also a whole life well being. Application: Since there are already many service applications advising patients about their illness and finding right doctors, this service design is focused on the experience from getting a prescription till feeling better. The next move is to combine those two parts medical services and design an integrated service application. As a prescription is going to be coded in numbers, we might consider to design an un-attended pharmacy which can shorten huge amount of time for filling prescriptions.

• 경영과정보연구
• /
• 제28권4호
• /
• pp.109-129
• /
• 2009

본 연구는 R&D시스템의 효율성을 체계적으로 평가하려는 목적을 가지고 있다. 구체적으로는 R&D투입(R&D투자, R&D인적자원관리), 과정(R&D계획, 외부네트워크 및 내부협력) 및 산출(기술혁신) 간의 관계를 실증적으로 규명하는 것이다. 대구경북지역 154개 IT 중소기업들을 대상으로 조사한 설문자료의 분석결과 IT중소기업의 R&D 인적자원관리는 R&D계획에 긍정적으로 유의한 영향을 미쳤다. R&D계획은 외부네트워크, 내부협력, 그리고 기술혁신에 긍정적으로 영향을 미치는 것으로 나타났다. 내부협력 역시 기술혁신에 긍정적으로 유의한 영향을 미치는 것으로 나타났다. 그러나 R&D투자가 R&D계획에 미치는 영향과 외부네트워크가 기술혁신에 미치는 영향은 유의하지 않는 것으로 나타났다. 이와 같은 연구결과는 IT 중소기업들에 있어서 R&D 인적자원이 매우 중요함을 제시하고 있다. 나아가 내부적인 협력이 타부서의 특유의 자원에 접근하게 하고, 새로운 자원을 개발하는데 소요되는 비용을 공유하게 함으로써 R&D 투입을 기술혁신에 효과적으로 연결시키는 것으로 나타났다. 그러나 IT 중소기업의 경우 R&D 투자는 R&D 계획에 유의한 영향요인이 아니며, 외부네트워크도 내부협력에 비해 혁신과정에서 덜 중요함을 암시하고 있다. 그 이유는 IT 중소기업의 경우 R&D 활동이 비공식적으로 이루어지는 경우가 많으며, 혁신성공에 있어서 외부요인보다는 내부요인이 더 중요하다는 것을 상기시키는 것으로 볼 수 있다.