NDF (No Defect Found) is a phenomenon in which defects have been found in the manufacturing, operation and use of a product or facility, but phenomenon of defects is not reproduced in the subsequent investigation system or the cause of the defects cannot be identified. Recently, with the development of the fourth industrial revolution, convergence of hardware and software technologies in various fields is spreading to products such as aircraft, home appliances, and mobile devices, and the number of parts is increasing due to functional convergence. The application of such convergence technologies and the increase in the number of parts are major factors that lead to an increase in NDF phenomena. NDF phenomena have a significant negative impact on cost, reliability, and reliability for both manufacturers, service providers and operators. On the other hand, due to the nature of NDF phenomena such as difficult and intermittent cause identification and ambiguity in judgment, it is common to underestimate the cost of NDF or fail to take appropriate countermeasures in corporate management. Therefore, in this paper, we propose a methodology for estimating NDF costs by the PAF model which is a quality cost analysis model and ABC (Activity Based Costing) technique. The methodology of this study suggests a detailed procedure and the concept to accurately estimate the NDF costs, using ABC analysis, accounting system information, and IT system data. In addition case studies have validated the methodology. We think this could be a valid methodology to refer to when estimating the cost of other parts. And, it is meaningful to provide important judgment information in the decision-making process based on quality management and ultimately reduce NDF costs by visualizing them separately by major variable factors.

This paper analyzed a survey of 388 general target samples to analyze the correlation between disaster safety costs and human risk factor analysis and evacuation behavior due to tunnel accidents. Considering the impact of the tunnel accident on disaster safety costs and the correlation between human evacuation and risk factors in the tunnel environment, the system should be reorganized to reflect the tunnel’s basic plan, tunnel cross-section, tunnel installation.

Nuclear power plants (NPPs) produce radioactive waste and decommissioning this waste entails additional cost; determining these costs for various types and specifications of radioactive waste can be challenging. The purpose of this study is to identify major determinants of the decommissioning cost and their impact on NPPs. To this end, data from defunct NPPs were gathered and 2SLS (Two Stage Least Squares) regression models were developed to investigate the major contributors depending on the reactor types, viz. PWR (Pressurized Water Reactors) and BWR (Boiling Water Reactors). Additionally, cost estimations and the Monte Carlo simulation were performed as part of performance validation. Our study established that the decommissioning costs are primarily influenced by the level of radioactivity in the decommissioned waste, which can be realized from operational factors like operation period, overall efficiency, and plant capacity, as well as from duration of decommissioning and labour cost. While our study provides an improved statistical approach to recognize these factors, we acknowledge that our models have limitations in forecasting accurately which we envisage to bolster in future studies by identifying more substantive factors.

PURPOSES : In this study, the social cost of on-street parking spaces was estimated by dividing it into private and external costs. METHODS : We established a methodology and conducted a case analysis of Seoul. Private costs were estimated from the guidelines and historical data collected. The opportunity cost of the land was estimated using spatial information. External costs built a macroscopic model (using TransCAD) and estimated travel time, operation, accident, and environmental costs. RESULTS : The social cost per space was estimated at 77 million won. Private costs were analyzed as 133.3 billion won, the opportunity cost of the land was 68,555 billion won, and external costs were 118,25 billion won in 2020. CONCLUSIONS : In this study, a methodology for estimating the social cost of a road parking facility was established and applied to the case of Seoul. Therefore, it is expected to contribute to the objective reviewing of the feasibility of policy evaluation or facility investment related to parking facilities.

식중독에 의한 사회경제적 손실을 최소화하기 위해서는 식중독과 관련된 경제적 비용 손실을 추정하는 것이 중요하다. 하지만 자료의 부족과 다양한 비용 항목의 존재로 식중독과 관련된 사회경제적 손실비용을 정확하게 추정하기에 어려운 점 있다. 본 연구에서는 국내 식중독 발생에 의한 손실비용을 추정하기에 앞서 국외에서 사용되는 사회경제적 비용항목의 기반 자료 확보를 목적으로 수행되었다. 2009-2019년 국외 식중독과 관련된 사회경제적 손실비용 측정 연구의 사례 조사를 위해 문헌 조사를 실시하였다. 이 연구에서는 사회경제적 손실비용을 크게 의료 기간에 방문한 외래/입원환자 및 의료기관에 미방문한 경험환자로 구분하였다. 또한 이들의 직접비용 및 간접비용을 고려하였고, 더 나아가 기업비용 및 행정비용 항목으로 구분하여 조사하였다. 조사 결과 문헌별, 나라별 상이한 비용항목을 사용하여 손실비용을 추정하는 것으로 관찰되었다. 직접의료비의 경우 모든 연구에서 외래 또는 입원진료비를 선정하여 비용을 산출한 것으로 관찰되었기 때문에 나라별 의료서비스의 체제 및 비용에 따라 항목을 선정해야 한다. 직접비의료비의 경우 몇 몇의 연구에서 외래 방문에 소요된 교통비만을 고려하였기 때문에 간병비 고려 여부에 대해서는 더 논의가 필요할 것으로 사료된다. 간접비용 중 조기사망비용, 작업손실비용, 여가손실비용 및 삶의 질 저하/고통비용은 고려하였으나, 병문안 기회비용은 모든 연구에서 고려하지 않았다. 직접의료비와 마찬가지로 행정비용의 경우에도 국가별 정부 예산이 상이하기 때문에 각 나라에 맞는 항목을 고려해야할 것이다. 따라서 이러한 조사 결과를 바탕으로 국내 식중독 발생에 의한 사회경제적 손실비용 분석을 위해 어떠한 비용 항목을 고려해야 할 것인지에 대한 검증절차가 필요할 것이다. 본 연구는 국내 식중독 발생에 의한 사회경제적 손실비용 분석을 위한 기초적인 정보를 제공할 것이다.

신축성 전극을 다양한 소재와과 방식을 통해 제조되고 있으며 많은 기계적 특성 분석이 연구되고 있다. 은, 구리, 금, 나노와이어 등 다양한 금속이나 CNT, graphene, 플러렌 등을 기반으로 연구되고 있으며 대부분 높은 전도성과 신축특성을 요구하는 어플리케이션에 사용되지만 고가라는 단점이 있다. 본 연구에서는 저비용 소재와 공정으로 높은 신축특성과 반복 특성을 보유한 신축성 전극을 개발하였다. 값싼 전도성 탄소 와 흑연을 혼합하여 페이스트를 개발하였고 개발된 페이스트를 메탈마스크 인쇄 공정을 통해 TPU기판 위에 인쇄하였고 120℃에서 2시간 경화를 진행하였다. 이렇게 개발된 전극을 인장 시험과 인장 반복 시험을 통해 특성을 증명하였고 향후 어플리케이션 적용 가능여부를 확인하기 위해 무릎에 임시로 고정 후 간이 시험을 진행한 결과 20회 반복하는 동안 일정한 저항 변화를 보여줬다.

This study aims to respond to the market of Tata Daewoo commercial vehicles in emerging countries (Southeast Asia) lightweight and cost-saving type for the production of dump trucks with secured price competitiveness requested to develop a square deck, and accordingly. This study is a 15-ton dump modified the reinforcement frame of the side gate to reduce the weight of the new truck model deck. It is designed to maintain the strength of 80% or more of the existing gate by (reducing input material). The system and structure rationalization proceeded.

PURPOSES : The aim of this study is to determine the maintenance costs for a reasonable preliminary feasibility study, feasibility study, or evaluation METHODS : This study was based on government budget execution and budget execution data for expressways, national highways, cable-supported bridges and long-tunnels. For the expressway, data obtained from the Korea Expressway Corporation were used. For the national highway, data was obtained from the Ministry of Land, Infrastructure and Transport. Similarly, data collected from expressway maintenance costs and the Korea Infrastructure Safety and Technology Corporation were used for long tunnels and cable-supported bridges, respectively. The items for highway maintenance cost were reclassified more rationally to facilitate the calculation of the maintenance costs. The replacement cycle for each item was also calculated based on the budget expenditure data. RESULTS : The results of this study showed the standard maintenance cost model for expressways, national highways, cable-supported bridges, and long-tunnels. In other words, a basis for predicting reasonable maintenance costs was prepared for a feasibility study. CONCLUSIONS : The reliability of the maintenance cost results was improved and it was more consistent with actual costs compared to the results of previous studies. It can be used as a basis for estimating the maintenance cost of a preliminary feasibility study and feasibility evaluation in the future.

The purpose of this study is to identify economic situation on scale of tuna distant longline fishery by analyzing its economies of scale using the cost function. To analyze its economics of scale, the deep-sea fishing statistics were used from 2012 to 2016. In detail, the number of panels for estimating the cost function was 68 tuna distant longline vessels from 2012 to 2016, and the total number of observations over the five years were 340. As a final model, the two-way fixed effect model based on the translog cost function was adopted through the F test, the Breusch-Pagan test and the Hausman test. As a result of the analysis, it was found that tuna distant longline fishery between 2012 and 2014 was diseconomies of scale, the fishery between 2015 and 2016 was economies of scale. However, the economic indicators of the scale from 2012 to 2016 were almost close to zero, indicating that the constant returns to scale, the optimal scale, were reached. Therefore, in the situation where the amount of fishery resources in the world continues to decrease, it is necessary to prepare a method to obtain economic benefits through scale maintenance and reduction rather than indiscriminate scale expansion.

본 논문에서는 고리 1호기 해체 비용 추정을 위해 외국 원자력발전소 해체 비용 데이터를 현가화한 후 원자력발전소 해체 비용 추정 회귀 분석모델을 개발하였다. 이 모델 개발에 사용된 데이터는 해체 또는 진행 중인 BWR 13기, PWR 16기의 해체 비용 데이터이다. 회귀 분석모델 도출을 위해, 해체 비용을 종속변수로 정하고, 해체 원전의 운전 특성을 반영할 수 있게 고 안된 Contamination factor와 해체 기간을 독립변수로 선정하였다. 빅데이터 분석 도구인 R language의 통계패키지를 이용 하여 회귀 분석모델을 도출하였다. 이 회귀 분석 모델을 적용하여 고리 1호기 해체 비용을 예측한 결과, 미화 663.40~928.32 백만 달러, 한화 약 7,828.12억~1조 954.18억 원이 소요될 것으로 예측되었다.

The global trend is the application of heat-treated omission materials to reduce the manufacturing cost of automobile steering parts. Attempts have been made to apply heat-treated omission materials in domestic, but they are delayed due to concerns over rising cold forging process costs. For quantitative prediction of cold forging process cost, fatigue properties of forging die materials were evaluated. Based on this, the die life and cost were predicted quantitatively, and the manufacturing cost reduction of automobile steering parts using heat-treated material was found to be about 11%. Also, various methods to improve die life were additionally presented.

The estimation of heat source model is very important for heat transfer analysis with finite element method. Part I of this study used adaptive simulated annealing which is one of the global optimization algorithm for anticipating the parameters of the Goldak model. Although the analysis with 3D model which depicted the real situation produced the correct answer, that took too much time with moving heat source model based on Fortran and Abaqus. This research suggests the procedure which can reduce time with maintaining quality of analysis. The lead time with 2D model is reduced by 90% comparing that of 3D model, the temperature distribution is similar to each other. That is based on the saturation of heat transfer among the direction of heat source movement. Adaptive simulated annealing with 2D model can be used to estimate more proper heat source model and which could enhance to reduce the resources and time for experiments.

Forged part made of Cold heading quality wire materials are used for automotive brake systems. The cost reduction of forged products is a major issue because of the strict shape change. A series of studies were conducted to minimize the cost of EPB spindle process among brake parts. In order to reduce the material cost, heat treatment-abbreviated material was applied and the formability on the processes was verified by the ductile fracture theory. In addition, the causes of shape fixation and die life degradation were analyzed using the numerical simulation. The process cost has been minimized by re-designing process, changing the product shape, and the die material.