• 한국안전학회지
• /
• 제30권3호
• /
• pp.32-37
• /
• 2015

In the fields of plant layout optimization, the main goal is to minimize the construction cost including pipelines as satisfying all constraints such as safety and operating issues. However, what is the lacking of considerations in previous researches is to consider proper safety and maintenance spaces for a complex plant. Based on the mathematical programming, MILP(Mixed Integer Linear Programming) problems including various constraints can be formulated to find the optimal solution which is to achieve the best economic benefits. The objective function of this problem is the sum of piping cost, pumping cost and area cost. In general, many conventional optimization solvers are used to find a MILP problem. However, it is really hard to solve this problem due to complex inequality and equality constraints, since it is impossible to use the derivatives of objective functions and constraints. To resolve this problem, the PSO (Particle Swarm Optimization), which is one of the representative sampling approaches and does not need to use derivatives of equations, is employed to find the optimal solution considering various complex constraints in this study. The EO (Ethylene Oxide) plant is tested to verify the efficacy of the proposed method.

• 한국IT서비스학회지
• /
• 제10권3호
• /
• pp.49-59
• /
• 2011

A ship scheduling model is presented for the raw material transportation problem with yard storage constraints in a steel mill. The problem is formulated as 0, 1 mixed integer programming considering such constraints as loading port conditions, ship size and hold capacity, unloading conditions, and yard storage space. In addition, inventory related constraints including safety stock are taken into consideration to support the continuous operations of steel making process. The proposed model has been implemented and applied successfully to a real world problem, and its results show the improvement of performance compared to the traditional method. For example, the arrival dates of ships are determined satisfying the constraints. The total inventory level is minimized at the stock yard as a result. Also, the safety inventory level is always kept at the planning stage, and the standard deviation of total inventory level is reduced significantly. Further research is expected to develop efficient heuristics to have a better response time for even larger scale problems.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2011년도 춘계학술대회
• /
• pp.541-552
• /
• 2011

Many of Korea major companies have appled as strategy of management innovation Six Sigma, Lean and Theory of Constraints. Six Sigma has mainly focused to reduce variation. Lean has mainly focused to reduce wastes and Theory of Constraints has mainly focused that bottleneck of constrains production and sales. This bottleneck is caused by constraint resources and it should be the main role of manager to explore constraint resource. Although their mainly focus are different, they are used to improve productivity and quality. In this paper, as strategy of management innovation, study on analysis and comparison plan of Six Sigma, Lean and Theory of Constraints. From the literature survey and application cases, it is suggested and discussed that how to plan of application as strategy of management innovation successfully. The suggested plan of application could be a good guideline that it could be a apply of companies.

• 한국식품위생안전성학회지
• /
• 제34권5호
• /
• pp.489-494
• /
• 2019

수출입 증명, 위생등급제, 식품 민원처리, 식품 관련 인증, 식품 위해정보 관리 및 식품이력추적 관리제도 등 식품안전관리 시스템에 블록체인 기술도입의 적절성을 효과성과 제약성 평가지표에 따라 전문가 대상 설문조사를 실시하여 평가하였다. 식품안전 업무영역별 블록체인 도입 적절성에 대한 포트폴리오 분석을 진행하여 블록체인 도입 우선순위를 설정하였다. 블록체인 도입 시 효과를 기대할 수 있는 영역은 식품인증, 위생등급제, 위해정보 및 수출입 증명 업무였다. 반면, 이력추적 및 민원처리업무의 경우 블록체인 도입의 효과성이 낮아 도입대상에서 제외할 것으로 평가되었다. 한편 조사된 6가지의 식품안전관리 업무영역 모두에서 블록체인 도입 시 비용, 법 제도 개정 등 보통 이상의 제약성이 존재하였다. 특히, 식품이력추적관리 분야는 도입 추진 시 가장 제약사항이 많을 것으로 평가되었다. 블록체인 도입 시 수출입 증명업무의 효과는 높으나 비용과 법 개정 등 제약성이 높아 블록체인 도입을 위해서는 제도개선 등이 필요할 것으로 판단되었다. 평가대상 업무분야들 중 식품인증, 위생등급제 및 위해정보 관련 업무는 블록체인 도입 시 신뢰성과 투명성을 크게 향상시키면서 제약성이 상대적으로 낮아 블록체인을 우선적으로 도입하는데 적합할 것으로 평가되었다.

• 한국가스학회:학술대회논문집
• /
• 한국가스학회 2005년도 춘계학술대회 및 특별심포지움
• /
• pp.231-231
• /
• 2005

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2012년 춘계학술대회
• /
• pp.221-232
• /
• 2012

Cycle analysis has been performed to find out the optimum design point of the BOG re-liquefaction plant. The cycle state, defined by three cycle variables, was mainly described by the three cold temperatures of the three-pass heat exchanger, on which the constraints by the heat exchanger are imposed. The cycle states which are confined within a domain limited by the temperature constraints were the primary issue of this study. The BOG mass within the domain was analyzed first and then the cycle performance was related to the BOG mass afterwards, which enabled us to explain the observed behavior of the cycle performance under the temperature constraints by the heat exchanger. A good cycle performance could be ensured if the two cold Nitrogen temperatures of the three temperatures were placed close together near $-140^{\circ}C$ while the BOG temperature is kept far above enough, but not too far, from $-140^{\circ}C$ such that it does not interfere in their optimum temperature range.

• 대한안전경영과학회지
• /
• 제7권1호
• /
• pp.159-166
• /
• 2005

It is not difficult to see the road repairing. There are many and various machines which crush road surface. The efficiency and power of the machine depend on crushing head-shape, crushing interval, crushing load, crushing stress, machine's dropping height and roller's kind. The objective of this study is to select the optimal model among ten models of crushing machine with constraints such as crushing depth, variation, and crushed particle size. And then this paper provides the valid theoretical base on selected model. The data for this study are chosen from the site of construction in Kangnung during three months (2004. 6. 1${\~}$2004. 8. 31). The provided methodology in this paper will be fruitful not only for the selection of crushing machine but also for the aspects of construction period, cost, work efficacy according to the condition from the various sites of construction.

• Safety and Health at Work
• /
• 제5권1호
• /
• pp.1-6
• /
• 2014

Background: Workflow interruptions during surgery may cause a threat to patient's safety. Workflow interruptions were tested to predict failure in action regulation that in turn predicts near-accidents in surgery and related health care. Methods: One-hundred-and-thirty-three theater nurses and physicians from eight Swiss hospitals participated in a cross-sectional questionnaire survey. The study participation rate was 43%. Results: Structural equation modeling confirmed an indirect path from workflow interruptions through cognitive failure in action regulation on near-accidents (p < 0.05). The indirect path was stronger for workflow interruptions by malfunctions and task organizational blockages compared with workflow interruptions that were caused by persons. The indirect path remained meaningful when individual differences in conscientiousness and compliance with safety regulations were controlled. Conclusion: Task interruptions caused by malfunction and organizational constraints are likely to trigger errors in surgery. Work redesign is recommended to reduce workflow interruptions by malfunction and regulatory constraints.

• 대한안전경영과학회지
• /
• 제8권3호
• /
• pp.87-101
• /
• 2006

This paper was concerned about case study for preventing WMDSs(Work-related Musculoskeletal Disorders) by using Thinking Process of TOC(Theory Of Constraints), Unfortunately, the number of WMDSs are rising steadily in auto-part manufacturer. These WMDSs have on worse and worse influence not only on the competition of enterprise but on the life quality of a worker. The research results are helpful to establish the preventing WMDSs and improvement of workplace environments for small-medium sized auto-part company.

• International Journal of Automotive Technology
• /
• 제6권6호
• /
• pp.635-641
• /
• 2005

This paper presents an ASF (Aluminum Space Frame) BIW (Body in White) optimal design, which minimizes weight and satisfies multidisciplinary constraints such as static stiffness, vibration characteristics, low-/high-speed crash, and occupant safety. As only one cycle CPU time for all the analyses is 12 hours, the ASF design having 11-design variable is a large scaled problem. In this study, ISCD-II and conservative least square fitting method were used for efficient RSM modeling. Likewise, the ALM method was used to solve the approximate optimization problem. The approximate optimum was sequentially added to remodel the RSM. The proposed optimization method uses only 20 analyses to solve the 11-design variable problem. Moreover, the optimal design can achieve $15.6\%$ weight reduction while satisfying all the multidisciplinary design constraints.