• Nuclear Engineering and Technology
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• v.41 no.1
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• pp.91-98
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• 2009

The "3+3 Process" for safety critical software for nuclear power plants' I&C (Instrumentation and Control system) has been developed in this work. The main idea of the "3+3 Process" is both to simplify the software development and safety analysis in three steps to fulfill the requirements of a software safety plan [1]. The "3-Step" software development process consists of formal modeling and simulation, automated code generation and coverage analysis between the model and the generated source codes. The "3-Step" safety analysis consists of HAZOP (hazard and operability analysis), FTA (fault tree analysis), and DV (design validation). Put together, these steps are called the "3+3 Process". This scheme of development and safety analysis minimizes the V&V work while increasing the safety and reliability of the software product. For assessment of this process, validation has been done through prototyping of the SDS (safety shut-down system) #1 for PHWR (Pressurized Heavy Water Reactor).

• Journal of the Korea Safety Management & Science
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• v.13 no.4
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• pp.61-69
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• 2011

The hazard conditions on plant works of the steel industry have been investigated to efficiently prevent from industrial accidents. The plant works are eventually carried out by workers of smaller service companies where the safety management systems are not well established, on behalf of the main steel company. Based on the preliminary risk assessment on the plant working and open literature reviews, the safety management systems, which can be applied to the plant workplace of each process, are studied and then the step-by-step 4M check-list method is established. Accordingly, the risk assessment technique using 4M checklist for the plant workplace is proposed. In addition, a standardized flow-chart for safety management of plant work is introduced. These risk assessment technique and flow-chart can definitely contribute to the reduction of industrial accidents, considering the risk characterization and the unsafe conditions in small and medium-sized plant workplace, as effective safety management tools and safety guide line.

• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.44-53
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• 2024

In addition to being used for ascending and descending to work locations, portable ladders are widely used as a substitute for work platforms when working at heights in homes and industrial sites. However, accidents continue to occur in industrial sites owing to structural instabilities of ladders and the negligence of safety measures by users. To prevent accidents involving workers using portable ladders, it is important to encourage workers to use them correctly through laws and regulations; however, establishing effective preventive measures that go beyond regulations can increase acceptance in industrial sites and maximize the effect of reducing industrial accidents. Therefore, this study conducts a fact-finding survey and portable safety ladder product analysis and collects stakeholder opinions to develop a Korean-style safety ladder that can replace step ladders with a high risk of accidents.

• The Korean Journal of Food & Health Convergence
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• v.6 no.5
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• pp.19-25
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• 2020

The purpose of this study was to research and develop a step-type chemical liquid deodorizer including a liquid catalyst that can prevent civil complaints due to odor due to its excellent deodorizing performance. The main composition of chemical liquid deodorizer including liquid catalyst is cleaning deodorization, catalyst deodorization, chemical deodorization, water film plate, deodorization water circulation device, deodorization water injection device, catalyst management system, gas-liquid separation device, chemical supply device, deodorizer control panel, etc. It consists of a device. The air flow of the step-type liquid catalyst chemical liquid deodorizer is a technology that firstly removes basic odor substances, and the liquid catalyst installed in the subsequent process stably removes sulfur compounds, which are acidic odor substances, to discharge clean air. The efficiency of treating the complex odor of the prototype was 98.5% for the first and 99.6% for the second, achieving the target of 95%. The hydrogen sulfide treatment efficiency of the prototype was 100% for the first and 99.9% for the second, which achieved 95%, which was the target of the project. As a result, ammonia was removed by the reaction of ammonia and hydrogen sulfide.

• Journal of the Korean Society of Safety
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• v.25 no.3
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• pp.22-27
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• 2010

A prediction performance of Fire Dynamics Simulator(FDS) developed by NIST for the diffusion flame structure was validated with experimental results of a laminar slot jet diffusion flame. Two mixture fraction combustion models and two finite chemistry combustion models were used in the FDS simulation for the validation of the jet diffusion flame structure. In order to enhance the prediction performance of flame structure, DNS and radiation model was applied to the simulation. The reaction rates of the finite chemistry combustion models were appropriately adjusted to the diffusion flame. The mixture fraction combustion model predicted the diffusion flame structure reasonably. A 1-step finite chemistry combustion model cannot predict the flame structure well, but the simulation results of a 2-step model were in good agreement with those of experiment except $CO_2$ concentration. It was identified that the 2-step model can be used in the investigation of flame suppression limit with further adjustment of reaction rates

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.404-406
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• 2016

Due to the localization process of offshore drilling system, ensuring safety has emerged as an important. Therefore, step by stem safety analysis about each development process of offshore drilling system is becoming compulsory. Hazard and operability analysis is a method that was successfully used for system safety analysis in industries such as chemical plants. Through this hazard and operability analysis study, to conduct step by step safety analysis accorsing to process, the study conducted hazard and operability analysis in Lp mud system, an area of offshore drilling system.

• Proceedings of the Safety Management and Science Conference
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• 2009.11a
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• pp.557-563
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• 2009

The research develops measurement processes for estimating and evaluating the gauge R&R(Reproducibility & Repeatability) using ANOVA(Analysis of Variance) of experimental design tools. The ten-step processes developed include experimental goal setting, the selection of characteristics(factors, levels), data model, ANOVA, EMS(Expected Mean Square), estimation of gauge precisions, and evaluation indexes. The three-factor combined measurement models are presented to show the processes developed in this paper.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.212-213
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• 2022

Recently, the construction industry is increasingly in need of securing safety rights due to repeated serious accident. Accordingly, the government enacted the "Serious accident Punishment Act" to strengthen punishment for serious accident and expand the scope of punishment. However, safety managers in the construction industry are still vulnerable to safety accidents due to the heavy workload. The purpose of this study is to increase the efficiency of performance tasks and reduce serious accidents in the construction industry through analysis of performance tasks by stages of construction projects. The tasks derived through domestic research and domestic and foreign system analysis were classified step by step to analyze the correlation between difficulty and preventive effect, and inefficient tasks were discovered and improved. This can be used as basic data for identifying safety management tasks and preparing effective safety prevention measures, and it is expected to be a preventive measure against industrial accidents in the construction industry by using it for efficient work reorganization by safety managers.

• Geomechanics and Engineering
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• v.19 no.2
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• pp.105-114
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• 2019

In this paper, simulation tests were conducted with similar materials to study the distribution of residual voids in longwall goaf. Short-time step loading was used to simulate the obvious deformation period in the later stage of arch breeding. Long-time constant loading was used to simulate the rheological stage of the arch forming. The results show that the irregular caving zone is the key area of old goaf for the subsidence control. The evolution process of the stress arch and fracture arch in stope can be divided into two stages: arch breeding stage and arch forming stage. In the arch breeding stage, broken rocks are initially caved and accumulated in the goaf, followed by the step deformation. Arch forming stage is the rheological deformation period of broken rocks. In addition, under the certain loads, the broken rock mass undergoes single sliding deformation and composite crushing deformation. The void of broken rock mass decreases gradually in short-time step loading stage. Under the water lubrication, a secondary sliding deformation occurs, leading to the acceleration of the broken rock mass deformation. Based on above research, the concept of equivalent height of residual voids was proposed, and whose calculation equations were developed. Finally, the conceptual model was verified by the field measurement data.

• Journal of Environmental Impact Assessment
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• v.21 no.5
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• pp.813-821
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• 2012

Environmental and public health concern for the emission of air pollutants from burn-up process in waste incineration plants located in the vicinity of living environment was increased during the past decade. The purpose of this study was to suggest of the simple and rapid method of priority setting model for the decision of full-scale public health assessment. This method was consists of total 5-step. Step 1 was "secure the satellite map" and we can use the satellite map which serves from the website such as NAVER Co. Step 2 was "drawing mesh on the map" for catch the point of occupation of environmental sensitivity facilities, and step 3 was "identification and sorting of the facilities", Step 4 was "setting of weight" using the "weighted linear combination (WLC) method". Finally, all facility was sorted by score. As a result, we can set a priority of 145 facilities based on 177 facilities which managed in local government. Facilities in Seoul metropolitan area was high rank in priority list. On the other side, Facilities located at the country or rural area was low rank because of low occupation of the house and the environmental sensitivity facilities such as kindergarten, elementary school, and hospital. In this study, we suggested simple and rapid method that using for screening procedure of public health assessment.