• 한국안전학회지
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• 제30권3호
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• pp.32-37
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• 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.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.404-410
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• 2017

In order to help decision-makers in the early design phase to improve and make more cost-efficient system safety and reliability baselines of aircraft design concepts, a method (Multi-objective Optimization for Safety and Reliability Trade-off) that is able to handle trade-offs such as system safety, system reliability, and other characteristics, for instance weight and cost, is used. Multi-objective Optimization for Safety and Reliability Trade-off has been developed and implemented at SAAB Aeronautics. The aim of this paper is to demonstrate how the implemented method might work to aid the selection of optimal design alternatives. The method is a three-step method: step 1 involves the modelling of each considered target, step 2 is optimization, and step 3 is the visualization and selection of results (results processing). The analysis is performed within Architecture Design and Preliminary Design steps, according to the company's Product Development Process. The lessons learned regarding the use of the implemented trade-off method in the three cases are presented. The results are a handful of solutions, a basis to aid in the selection of a design alternative. While the implementation of the trade-off method is performed for companies, there is nothing to prevent adapting this method, with minimal modifications, for use in other industrial applications.

• International Journal of Railway
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• 제5권4호
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• pp.175-181
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• 2012

This study proposes a model for railway safety assessment with which the safety of whole railway system can be evaluated. The purpose of the assessment model is to generate safety indicators which quantitatively represent the degree of railway safety. Safety indicators were proposed as three indicators according to their functions; accident indicators, safety management indicators, and safety culture indicators. This paper describes the first result on the safety target which will be a key starting point toward the development of safety assessment model. It is recommended that the safety target to be composed of several sub-targets are apportioned to constituent components. It is concluded that the classification of safety target has influence on deciding components or attributes that constitute each sub-indicators; accident indicators, safety management indicators, and safety culture indicators. Based on this study, a railway safety assessment model will be developed in the following study.

• 한국건설관리학회논문집
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• 제6권5호
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• pp.148-156
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• 2005

본 연구에서는 건설현장의 안전관리 관련 선행연구 고찰을 통해, 현행 건설현장의 안전관리체계를 구성하고 있는 기본 구성 요소를 파악하고 이러한 선행연구들이 제시한 주요항목을 건설현장 안전관리활동에 반영하는 것이다. 선행연구의 분석을 통해 1)본사는 안전보건경영체제 중심으로, 건설현장은 근로자를 배려하는 활동 위주의 체계가 중요함 2)성공적으로 안전관리 활동을 추진한 건설현장에 대한 실제 안전관리활동 주요요인들을 건설현장 안전관리활동의 실천방안으로 일반화 시키지 못하는 한계점이 있었다. 이러한 한계점을 해결하기 위하여 본 연구에서는 기존 선행연구에서 주장하고 있는 건설현장의 성공요인 분석과 국내의 27개 안전관리활동 우수사례 현장에 대한사례조사를 통해 건설현장의 안전관리활동 주요요인(위험성 관리방법, 산업안전보건위원회 운영, 안전교육의 실시, 안전점검, 작업장 환경개선, 안전활동)을 도출하였고, 도출된 6가지 주요요인에 대한 실천방안을 제시하였다.

• 대한안전경영과학회지
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• 제7권4호
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• pp.39-48
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• 2005

Both supply chain management and safety management contribute to strengthening a company's competitiveness. However, there is no previous research that considers supply chain management and safety management simultaneously The objective of this research is to study on application of safety management to supply chain. In this paper, the concept of supply chain safety management is defined. Based on the concept of supply chain safety management, supply chain safety management model is developed that consists of supply safety management, production safety management, storage safety management, and distribution safety management. In order to apply supply chain safety management, a methodology is developed that consists of four phases. Applying the supply chain safety management model, it is expected a company to lower cost as well as to raise customer satisfaction level.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 사면안정학술발표회
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• pp.33-42
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• 2003

Since the cut slope has been big concern due to frequent failures, the government decided to include cut slopes in the“Act for Safety Control of Public Structures”. Based on the Act, the cut slope whose height is over 50m and length is over 200m should be inspected on the regular basis. According to the Act, KISTEC developed the objective evaluation method for the condition of cut slope. The evaluation method is divided into two categories: evaluation for damaged condition and evaluation for failure affecting factor. Based on the evaluation results, the cut slope is graded from A to E. In this study, the process to evaluate the cut slope condition and the evaluation criteria to divide the grade of cut slope are introduced.

• 상하수도학회지
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• 제32권2호
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• pp.115-122
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• 2018

Direct spring loaded pressure relief valve(DSLPRV) is a safety valve to relax surge pressure of the pipeline system. DSLPRV is one of widely used safety valves for its simplicity and efficiency. However, instability of the DSLPRV can caused by various reasons such as insufficient valve volume, natural vibration of the spring, etc. In order to improve reliability of DSLPRV, proper selection of design factors of DSLPRV is important. In this study, methodology for selecting design factors for DSLPRV was proposed. Dynamics of the DSLPRV disk was integrated into conventional 1D surge pressure analysis. Multi-objective genetic algorithm was also used to search optimum design factors for DSLPRV.

• 대한안전경영과학회지
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• 제4권1호
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• pp.131-139
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• 2002

Since introducing the "Theory of Constraints" by Goldratt, its effect was verified by lots of scholars, men of enterprise. These days it is also introducing and studying in this country with good results. The objective of this study is to show how to determine the constraint resources on DBR scheduling. Actually, previous studies based on the line which just think a load/capacity rate on doing scheduling. This study will show a scheduling method which reflects multi-parameters. It could be a standard to reflect real manufacturing surroundings. On calculating a priority of each resources, we classified factors with subjective and objective factors. And we propose a decision model to incorporate values assigned by a group of experts on different factors to select a critical resource. On deploying this model, SN ratio of Taguchi method for each of subjective and objective factors will be used. And we propose a procedure which is organized with 7 steps. To understand the logic, a numerical manufacturing simulation will be presented. This method is a incorporating decision model on determining the constraint on multi parameters with experts.h experts.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1838-1854
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• 2023

This paper presents a hybrid algorithm to solve the multi-objective path planning (MOPP) problem for mobile robots in a static nuclear accident environment. The proposed algorithm mimics a real nuclear accident site by modeling the environment with a two-layer cost grid map based on geometric modeling and Monte Carlo calculations. The proposed algorithm consists of two steps. The first step optimizes a path by the hybridization of improved ant colony optimization algorithm-modified A^* (IACO-A^*) that minimizes path length, cumulative radiation dose and energy consumption. The second module is the high radiation dose rate avoidance strategy integrated with the IACO-A^* algorithm, which will work when the mobile robots sense the lethal radiation dose rate, avoiding radioactive sources with high dose levels. Simulations have been performed under environments of different complexity to evaluate the efficiency of the proposed algorithm, and the results show that IACO-A^* has better path quality than ACO and IACO. In addition, a study comparing the proposed IACO-A^* algorithm and recent path planning (PP) methods in three scenarios has been performed. The simulation results show that the proposed IACO-A^* IACO-A^* algorithm is obviously superior in terms of stability and minimization the total cost of MOPP.

• Nutrition Research and Practice
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• 제10권2호
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• pp.237-244
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• 2016

BACKGROUND/OBJECTIVES: The current South Korean government policy on food irradiation technology should be reformed based on an in-depth investigation of the communications aspect, because the issue is no longer of a technological nature, given the proven safety and efficacy of the processes. SUBJECTS/METHODS: The target population of the education program consisted of elementary, middle, and high school students attending 310 schools in South Korea (2013: 63 schools, 2014: 104 schools, 2015: 143 schools). Data subjected to analysis were 13,327 pre-education and 12,641 post-education questionnaires received from 7,582 elementary, 2,671 middle, and 3,249 high school students who participated in the education program from May 2012 to April 2015 (n = 12,831), after the exclusion of inadequately filled-in questionnaires. RESULTS: Analysis of the three-year educational effect trend was conducted by comparing levels of variables before and after food radiation education. The analysis yielded the finding that the post-education levels were significantly higher for all variables. That is, for interest in education, perception (necessity, safety, subjective knowledge, and information acquisition), objective knowledge, and attitude, with the sole exception of objective knowledge in 2013. CONCLUSIONS: Given that post-education levels of perception, knowledge, and attitude concerning irradiated foods increased considerably compared to pre-education levels, behavior change should be induced by providing continuous education to enhance, these primary variables.