• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.283-290
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• 2017

Objectives: This study aimed to evaluate the relationship between filter replacement and filter performance change in particulate filters used in the workplace. Methods: Three types of particulate respirator filters are mainly used in the workplaces. These were tested against the filter performance safety certification standard for dust masks established by the Ministry of Employment and Labor(MoEL). Used filters were collected to test their performance, such as filter pressure drop, efficiency, and quality factors. All these factors were evaluated by a filter tester. To compare filter performance between used and new ones, the same kinds of new filters were also tested together under the same procedures. Results: A total of 270 used filters were collected for testing. The main reasons to replace the filters were difficulty in breathing(46.2%), dirty/odor influx(19.7%), and a combination of factors(26.7%). The pressure drop for two special class groups was significantly different(new filters: $20.72{\pm}3.33mmH_2O$; used filters: $24.70{\pm}5.26mmH_2O$, p<0.0001). In the case of penetration, new filter groups indicated $0.0032{\pm}0.0040%$, while that of the used filters was $0.0596{\pm}0.1187%$. The quality factor for the used filters($0.34{\pm}0.09$) significantly decreased compared to the new filters($0.53{\pm}0.08$) (p<0.0001). Conclusions: Filter performance including pressure drop, penetration, and the quality factor was evaluated and compared between new and used filters in the workplace. The results showed that general filter performance deteriorated more for change of pressure drop, penetration and the quality factor.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.22-29
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• 2015

Many enterprises have been adopting management systems good enough for them and operating the schemes to have competitive edge better than their competitor. One of the finest systems that most companies have been selecting is ISO 14001. ISO 14001, environment management system, is widely known as advancing internal efficiency and productivity in the various industries. As a result, the number of companies that have adopted ISO 14001's certification have been increasing continuously year by year since ISO 14000 standard was called in 1994s from ISO 18000 standard that originally used. The purpose of this study is to present that ISO 14001's requirement execution influences on management performance in the small manufacturer. In order to carry out this research, we obtained 96 survey sheets and inspected ten assumptions based on the reliability, validity of the questionnaires. The results of regression analysis are summarized as follows; First, the three factors of ISO 14001 requirement, plan, implementation and operation and management consideration, have an important effect on the operational performance. Second, the three elements of ISO 14001 requirement, environment policy, implementation and operation and management consideration, affect to the financial performance significantly. Based on the results, it is sure that the companies that execute the factors of implementation and operation and management policy have a good performance to achieve operational and financial performance so that it is important to clarify the member's role, authority and follow the procedure by a company's process. Also, the truth shows CEO's continuous will and periodical review of ISO 14001 influence on management performance as well.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.6
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• pp.495-502
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• 2020

The 37 indicators for performance evaluation of public sewage management agencies are divided into four major categories (agency manpower management ability, wastewater treatment plant operation and management, sludge and water reuse, service quality) in the first stage, and the necessity and score acquisition for the detailed indicators by each major category in the second stages. Priority was investigated through the Analytic Hierarchy Process (AHP) analysis technique for ease and relevance of company efforts. Also, based on the results of this analysis, integrated type weighting and relative importance were analyzed. As a result of the analysis, the weight and relative importance of the first stage classification were in the order of wastewater treatment plant operation and maintenance, operation agency manpower management ability, sludge and water reuse, and service quality. As a result of analyzing the weights and priorities of the detailed performance indicators in the second stage, it was found that operator's career years, the percentage of certification holding rate in operators, compliance with the effluent water quality standards, training times for operators, and efforts to manage hazardous chemicals were important. Some of the indicators of operation agency performance evaluation may include indicators in which the performance of the company's efforts is underestimated or overestimated. In order to improve this, it is necessary to give weights in consideration of the necessity of the indicator, the relevance of the company's efforts, and the ease of obtaining scores.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.263-282
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• 2023

Purpose: This study aimed to examine the impact of FSSC 22000 food safety management system characteristics on the business performance of food-related companies and to verify the mediating effect of organizational capabilities in the relationship between them. Methods: To achieve this, a survey was conducted among employees of food companies in Seoul and the metropolitan area that have implemented the FSSC 22000 food safety management system, and the following main results were derived. Results: First, the FSSC food safety management system factors, such as measurement/analysis and improve- ment, documentation, management responsibility, and service and product realization, were found to have a significant positive (+) impact on organizational capabilities. The relative impact was in the order of measurement/analysis and improvement, documentation, management responsibility, and service and product realization. Second, organizational capabilities were found to have a significant positive (+) impact on business performance. Third, the FSSC food safety management system factors, such as measurement/analysis and improvement, management responsibility, resource management, and documentation, were found to have a significant positive (+) impact on business performance. The relative impact was in the order of measure- ment/analysis and improvement, management responsibility, resource management, and documentation. Fourth, the factors of management responsibility, resource management, measurement/analysis and improvement, and documentation, excluding resource management factors, were found to have a positive impact on business performance through the mediation of organizational capabilities. Conclusion: The results of this study may provide important implications for the implementation and efficient operation and management of the FSSC 22000 food safety management system in enhancing the business performance of food-related companies.

• Journal of Practical Engineering Education
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• v.14 no.2
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• pp.225-234
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• 2022

There is an increasing number of competency-based major courses organized and operated to develop various competencies. Here, competencies include key competencies/major competencies in the evaluation of basic competency diagnosis in universities, Program Outcomes of engineering education certification, and NCS competency units. The Ministry of Education's evaluation of basic university competency requires all major courses to be organized and operated to improve the major competency of the department, and major courses in the department that operates engineering education certification should be linked to Program Outcomes. Various types of competency-based major courses should be educated to improve related competencies, and educational performance should be measured by selecting a competency evaluation method that allows students to check the level of achievement in consideration of both the process and results of performance. Therefore, this paper examines the types of competency evaluation used to measure educational performance in major subjects related to competency, proposes an evaluation method that synthesizes and measures various types of competencies at the subject level, and presents examples of applying them to major subjects.

• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.558-565
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• 2012

Abnormal climate or weather is more frequently reported nowadays due to the global climate change. Especially, extremely low temperature in winter season may cause bad thermal discomfort of passengers. In this study, the effect of car heating modes on cabin temperature change and distribution was studied by using a real-scale environmental chamber for passenger cabin. It was found that the cabin temperature rose quickly at the initial stage of heating system operation, but it stopped increasing after certain point. And, temperature was higher when the height from the floor was higher. Based on the obtained result, the way to minimize the decrease of passengers' thermal comfort was suggested.

• KIEAE Journal
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• v.16 no.3
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• pp.77-82
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• 2016

Purpose: The aim of this study is to calculate U-factor of the window using international standard methods and compare quantitative and tendency difference focused on ISO standard 15099 and ISO standard 10077. And the result of ISO standard calculation methods is verified using thermal performance experiment to evaluate applicability of domestic certification system. This study is utilized a basis for activation of domestic window certification system. Method: First, 16 cases are selected that is combined a variety of frame, Glazing, spacer, etc. The selected cases were simulated using WINDOW&THERM based on ISO 15099 and 10077 calculation method. Second, experiment was conducted based on Korean standard condition. Then, it was compared the error of experiment and simulation results. Through this process, ISO 15099 and 10077 calculation methods were evaluated accuracy and utilization. Result: The results show that the difference of ISO 15099 and ISO 10077-2 is maximum 5.4%. The results of comparing U-factor errors based on the Korea standard experiment test found 2.4%. Consequently, it will be possible to combination calculation methods of ISO 15099 and ISO 10077 for a single window.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.27-34
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• 2005

Mobile Ad Hoc Networks (MANETs) are self-organized networks that do not rely in their operation on wired infrastructure. As in any networking technology, security is an essential element in MANET as well, for proliferation of this type of networks. But supporting secure communication in MANETs proved to be a significant challenge, mainly due to the fact that the set of nodes in the network can change frequently and rapidly and due to the lack of access to the wired infrastructure. In particular, the trust model and the authentication protocols, which were developed for wired and infrastructure-based networks, cannot be used in MANETs. In this paper, we address the problem of efficient authentication of distributed mobile users in geographically large networks. In particular, we propose a new authentication scheme for this case of MANETs. The proposed scheme exploits Randomized Groups to efficiently share authentication information among nodes that together implement the function of a distributive Certification Authority (CA). We then evaluate the performance of authentication using Randomized Groups.

• KIEAE Journal
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• v.13 no.2
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• pp.113-122
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• 2013

On July 2004, the brand new CASBEE for construction (Brief version) has completed while trying to highlight and improve major items adequate for each region's characteristics in Japan; at the same time, from the start of NAGOYA CITY (operated since April 2004) to the point of May 2011, it has been mandatory for specified size buildings in 23 regions by law. Evaluation sheet of CASBEE is published on each region's home page and various genre of information on building evaluation which is scheduled to be completed by 2016 and is for 5-6 years of quantity is accumulated until October 2012. It is good study resource to verify how new buildings being evaluated are closely match with CASBEE's original purport (eco-friendly, energy efficiency, publicity etc). Particularly, for Japan's multi-family housing where small sized mid to high level single housing type is majority in city, it is an important point that improved performance on eco-friendly buildings have more value in city rather than suburb. Categorized score through evaluation is a resource to confirm the latest trend of multi-family housing built in congested city; on the other hand, demand of the time can be recognized by the score focused on category. It is meaningful resource to determine the adequacy of evaluated items and the degree of reality.

• Journal of Aerospace System Engineering
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• v.14 no.spc
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• pp.31-38
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• 2020

The aircraft system safety assessment, which is emphasized in the development and certification of aircraft, is a systematic and comprehensive evaluation process to determine that all relevant failure conditions have been identified and that all significant combinations of failures cannot result in unacceptable hazards. As the aircraft systems become more complex and require integrated function and performance, proper safety objectives must be established and appropriate assessments are need to be accompanied. This paper has prepared to propose the efficient probabilistic analysis of failure data to evaluate the risk level over the entire aircraft lifecycle through the safety assessment and to review the considerations for aircraft certification and safety improvement.