• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.6
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• pp.535-540
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• 2022

DC-link capacitors are reliability-critical components in a photovoltaic (PV) inverter. Typically, the lifetime of a DC-link capacitor is evaluated by considering the voltage and hot-spot temperature of the capacitor under the specific operating condition of the PV inverter. However, the output of the PV inverter is determined by solar irradiation and ambient temperature, which vary with the seasons; accordingly, the hot-spot temperature of the capacitor also changes. Therefore, the mission profile of the PV system should be considered to effectively evaluate the reliability of the DC-link capacitor. In this study, the reliability of the DC-link capacitor of a three-level NPC inverter is comparatively analyzed with and without considering the mission profiles of the PV system, where two mission profiles recorded in Arizona and Iza are considered. The accumulated damage of the DC-link capacitor is calculated based on the lifetime model by analyzing its thermal loading. Afterward, a reliability evaluation of the DC-link capacitor is performed at the component level and then at the system level by considering all capacitors by means of Monte Carlo analysis. Results reveal the importance of performing a mission-profile-based reliability evaluation during the design of high-reliability PV inverters to achieve the target reliability performance.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.479-496
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• 2019

Purpose: The purpose of this research is to develop defense quality evaluation model in order to improve the problem of private sector quality evaluation model and propose the total integrated defense quality management model which enables to evaluate not only large defense industry, but also small-medium industry. Methods: This paper consider the characteristics on ISO 9001 Quality Management System, single PPM, PASS and defense quality and develop defense quality maturity model and index which enables to measure the current quality management level and characteristics and to evaluate operational characteristics in each maturity level for domestic defense industry. Results: From 176 DQMS certified defense industry, the defense quality maturity level is 68,2, C grade. The large defense industry shows, 80.9, A grade; medium industry 69.7, C grade; small-medium industry shows 54.1, D grade. Through the classified types of industries, the current level of quality management of defense industries was diagnosed and the areas to be supplemented for the total quality management were identified. Conclusion: Developed DQMI can be used as the basic information for spreading quality management activities in the defense industry by diagnosing the overall quality management of existing defense industries and quantifying the ambiguity of non-metric measurements and measurement standard that were presented as the threshold of the defense quality management system certification process.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.3
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• pp.59-70
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• 2023

In order to predict low-level wind shear at Incheon International Airport (RKSI), a Low-Level Wind Shear prediction system (KMAP-LLWS) along the runway take-off and landing route at RKSI was established using Korea Meteorological Administration Post-Processing (KMAP). For the performance evaluation, the case of low-level wind shear cases calculated from Aircraft Meteorological Data Relay (AMDAR) from July 2021 to June 2022 was used. As a result of verification using the performance evaluation index, POD, FAR, CSI, and TSS were 0.5, 0.85, 0.13, and 0.34, respectively, and the prediction performance was improved by POD, CSI, and TSS compared to the Low-Level Wind Shear prediction system (LDPS-LLWS) calculated using the Korea Meteorological Administration's Local Data Assimilation and Prediction System (LDAPS). This means that the use of high-resolution numerical models improves the predictability of wind changes. In addition, to improve the high FAR of KMAP-LLWS, the threshold for low-level wind shear strength was adjusted. As a result, the most effective low-level wind shear threshold at 8.5 knot/100 ft was derived. This study suggests that it is possible to predict and respond to low-level wind shear at RKSI. In addition, it will be possible to predict low-level wind shear at other airports without wind shear observation equipment by applying the KMAP-LLWS.

• Journal of The Korean Institute of Defense Technology
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• v.5 no.2
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• pp.23-30
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• 2023

TRA(Technology Readiness Assessment) quantitatively assesses the current level of domestic technology and is used as a key tool for determining the possibility of domestic R&D and risk management. However, since the current TRA utilizes hardware-oriented TRL(Technology Readiness Level), it is suitable for independent assessment of each technologies, but has limitations in evaluation from a system integration perspective. In addition, the checklist-based assessment is highly likely to involve subjective evaluation. This study proposes an enhanced TRA framework by redefining TRA procedures and criteria from the systems integration perspective of system engineering. We focused on developing a framework that overcomes the limitations of the current TRL/TRA and enables easier and more intuitive assessment. The proposed framework distinguishes between TE(Technology Element) and CTE(Critical Technology Element) in terms of HW, SW and interface and redefines TRL. TRA is performed according to the TRL redefined from the above three points of view, and the lowest evaluation value is used as system maturity level in consideration of risk management. The proposed CTE selection method minimizes the intervention of the evaluator by utilizing the quantitative goal of the key ROC(Required Operational Capability), development difficulty, and application of COTS(Common Off The Shelf) technology. The effectiveness of this framework was confirmed through a case study of the TSS(Target Surveillance System). It is hoped that starting with this study, research at the framework level will be activated and contribute to the improvement of the TRA system.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1731-1736
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• 2004

The purpose of this article is to introduce a useful methodology of effective goal-setting for the team-level units. As a way to overcome some common symptoms in terms of Strategic Performance Evaluation System such as lack of knowledge on goal-setting, disconnection of process, problem of judging the degree of difficulty about objectives, limits of staff departments evaluation, fairness and authority of evaluators, weakness in coaching technique, and quantity or figure-oriented evaluation, to name a few, and to seek a more plausible goal-setting methodology, the author suggests a persuasive goal-setting concept: VAR(Value-Added Results). VAR, as the end-results, is the team contributions that add value to the organization, and it results from the team's activities. In addition to these goal-setting technique based on the concept of value-added results, several aspects should be improved for Strategic Performance Evaluation System to be implemented more effectively. They are: 1) shift from MBO to MP & D(Managing Performance & Development), 2) impartial exercise of evaluation authority as a organizational public assets, 3) reinforcement of maternal leadership and servantship instead of paternal leadership, 4) utilization of IT-based evaluation system.

• Journal of The Korea Institute of Healthcare Architecture
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• v.17 no.4
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• pp.25-37
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• 2011

As International considerations about the Barrier-Free environment increase, Korean Barrier-Free Environment Certification System has operated since 2008 in Korea. The purpose of this study is to find way to improve evaluation items, so this study analyzed the result of examination certified facilities and investigated the importance of the evaluation item for conducted a questionair survey with the BF experts. As a result, a lower scored and high important item should assign a higher score or lower the difficulty level, so induces applicants to be certified. Second, a higher scored and lower important item should assign a lower score or increase the difficulty of evaluating. The results suggested are expected the use in the improvement direction of BF certification evaluation items.

• Journal of Korean Port Research
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• v.13 no.1
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• pp.79-86
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• 1999

This paper deals with the evaluation problem of complex systems by introducing a fuzzy approach. The authors are functionally supposing a hierarchical structure model of a complex system and give light on the following problems. First for the purpose of clarifying the characteristics of measures the property and differences between two method such as linear and fuzzy viewpoint are discussed through two level-down evaluation process. Second the integrated evaluation process which keeps reversibility between hierarchical levels is discussed and obtained some necessary conditions for reversibility of fuzzy evaluation. From these results it is expected that the fuzzy approach overcomes partly the limitation of reductionism at the hierarchical evaluation of complex systems.

• Management & Information Systems Review
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• v.12
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• pp.37-52
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• 2003

An informatization evaluation is becoming a major issue among vocational colleges, as the 21th century begins. This century is characterized as Knowledge and Information era. Thus it is popular for administrative organizations to use Information Technologies as major tool to innovate themselves. The main objective of this study is develop evaluation indexes on applications of information technologies for vocational colleges because they must operate their education services by using management principles. Four major indexes were recommended to evaluate their information environment of educational service as follows. 1. Strategic Information System 2. Environmental Factors of Information System 3. Informational Resources 4. Utilization of Information Technologies Each index has 4 variables to identify the level of informatization and every variable is consisted of several questions. Such an evaluation system will be applied for vocational colleges to know their own situation of IT application and to develop managerial strategies by using IT. This system also will be useful to compare you with your potential competitors and to find appropriate polices of IT application by measuring the indexes at different points of time.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.67-70
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• 2003

In recent, the importance and necessity of some studies on reliability evaluation of grid come from the recent black-out accidents occurred in the world. The quantity evaluation of transmission system reliability is very important under competitive electricity environment. The reason is that the successful operation of electric power under the deregulated electricity market depends on transmission system reliability management. The various results of many case studies for the IEEE 25buses system using the Transmission Reliability Evaluation for Large-Scale Systems(TRELSS) Version 5_1, a program made in EPRI are introduced in this paper. Some sensitivity analysis has been included. This paper suggests that the some important input parameters of the TRELSS can be determined optimally from this sensitivity analysis for high reliability level operation of a system.

• Journal of Korean Society of Rural Planning
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• v.16 no.3
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• pp.159-171
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• 2010

Since rapid industrialization of Korean society, out-of-village roads have been greatly improved, while almost all of in-village roads have not been fundamentally improved yet. Unless village roads should be improved in relatively comparison with trunk roads, it has been widely recognized that grass rooted achievement of accessibility revolution not be realized. In this regard, this study tried to develop evaluation indicators system for improvement of village roads. The evaluation indicator system on village road conditions was proposed which is sub-categorized as structural improvement of road itself, its communication serviceability and public securing level of property rights of road site. The system has 6 indicators(2 of each subcategory);good pavement ratio and over 3m wide road length ratio, ratio of household fronting under 2m wide road and connectivity of road network, ratio of registered as 'road' in land category and ratio of publicly owned road sites. In the final conclusion, village roads in rural Korea have been generally in worse condition regardless of whether prior improvement works or not, except some of recent plan-based improvement villages.