This study comparatively analyzes the energy generation performance and economic evaluation of monofacial and bifacial photovoltaic (PV) modules, utilizing empirical data obtained from the Saemangeum project. The analysis is based on field data collected over a three-year period from 2022 to 2024. The results indicate that bifacial modules achieved an average power generation increase of approximately 8.27% compared to monofacial modules, attributed to the additional energy yield from rear-side irradiance. For the economic assessment, the Levelized Cost of Electricity (LCOE) and the Break-Even Point (BEP) were analyzed. Although the initial investment cost for bifacial modules was approximately 7.4% higher than that of monofacial modules, the LCOE was found to be lower for bifacial modules (114.7 KRW/kWh) compared to monofacial modules (117.8 KRW/kWh) over a 20-year operation period, due to the benefits of increased energy generation. The BEP analysis revealed that bifacial modules reach a break-even point relative to monofacial modules after 7.02 years. Furthermore, the study examined the trends of the BEP in response to variations in electricity selling prices and bifacial gain. In conclusion, this study confirms that bifacial PV modules demonstrate superior results in both power generation performance and economic analysis within the testbed environment. Consequently, these findings suggest a high potential for the application of bifacial modules in future domestic and international photovoltaic projects.

This study verified the moderating effects of personality types (Ego-States) on the relationship between Training Attitude (TA), Training Environment (TE), and Training Performance (TP) among Work-Learning Dual program apprentices. Drawing from Transactional Analysis, personality types were classified into five Ego-States: Critical Parent (CP), Nurturing Parent (NP), Adult (A), Free Child (FC), and Adapted Child (AC). An analysis of 354 apprentices revealed significant differences in TP scores. The FC and A types demonstrated the highest performance (mean scores of 4.11 and 4.05 out of 5, respectively), whereas the CP and NP types recorded lower scores (3.25 and 3.30, respectively). Regarding the moderating effects, TA was found to have a significant effect on TP at the 5% significance level, and the interaction term between TA and personality type also showed a significant effect on TP at the 5% level. Consequently, personality type was identified as a quasi-moderator for TA. Specifically, the positive effect of TA was weakened for the AC type but strengthened for the FC type. In the case of TE, the analysis indicated no significant direct effect on TP at the 5% significance level. However, the interaction term between TE and personality type significantly influenced TP at the 5% level, thereby confirming personality type as a pure moderator for TE. This significant impact was observed specifically for the A and AC types. These findings demonstrate that the pathway to high training performance is not uniform. The results strongly suggest the need for differentiated training management and instructional design tailored to the specific personality profiles of apprentices to maximize program effectiveness.

본 연구는 상수리나무(Quercus acutissima) 종자의 발아 효율성과 유묘 생장 특성을 향상시키기 위하여, KNO3 priming 처리 시간(24, 48시간)과 농도(0.5%, 1.0%, 1.5%)를 비교하여 최적 조건을 도출하고자 실시하였다. 충실 종자를 선별한 뒤 KNO3 용액에 priming 처리하여 발아특성과 유묘 생장특성을 평가하였다. 전반적으로 24시간-1.0% KNO3 처리구는 발아율, 발아속도, 발아균일지수 및 유묘 생장 특성에서 대조구보다 유의하게 높은 값을 보였다(p < 0.05). 그러나 농도가 높아지거나 처리 시간이 길어질수록 이러한 효과는 감소하여 대조구와 큰 차이를 보이지 않았다. 이상의 결과를 종합할 때, 상수리나무 종자의 발아 및 초기 유묘 생장에 가장 효과적인 KNO3 priming 조건은 KNO3 1.0%, 24시간 처리인 것으로 판단된다.

The casting manufacturing process of aluminum automotive wheels often involves processing various wheel models during stages such as flow forming, machining, packaging, and delivery. Traditionally, separate equipment or production lines were required for each model, which led to higher facility investment costs and increased labor costs for classification. However, the implementation of machine learning-based model classification technology has made it possible to automatically and accurately distinguish between different wheel models, resulting in significant cost savings and enhanced production efficiency. Additionally, this approach helps prevent product mix-ups during the final inspection process and allows for the quick and precise identification of wheel models during packaging and delivery, reducing shipping errors and improving customer satisfaction. Despite these benefits, the high cost of machine learning equipment presents a challenge for small and medium-sized enterprises(SMEs) to adopt such technologies. Therefore, this paper analyzes the characteristics of existing machine learning architectures applicable to the automotive wheel manufacturing process and proposes a custom CNN(Convolutional Neural Network) that can be used efficiently and cost-effectively.

This study identified the core competencies of aircraft maintenance quality engineers and compared the importance and retention of core competencies. Through literature research, 21 core competencies were derived in three areas of management technology, elemenal technology and collaboration technology, and a survey was conducted on the importance and retention of core competencies for 42 aircraft maintenance quality engineers. As a result of the survey, the importance of all core competencies of aircraft maintenance quality engineers is 3.95/5 on average, and the retention of all core competencies is 3.99/5 on average. 'Risk Management’, ‘Creating Document’, ‘Honesty/Moral’ were identified as the most important competencies in each area, and ‘Quality Management’, ‘Language’, ‘Honesty/Moral’ were identified as the most possessed competencies in each area. An IPA (Importance-Performance Analysis) was performed to analyze the details. Through IPA, ‘Risk Management’ and ‘Safety Management’ were evaluated as having a low degree of retention compared to a high level of importance. Therefore, they were identified as a core competencies that need to be improved first. In addition, the characteristics of each core competency and the recognition level in the field were also identified. This study will be helpful in defining the roles and functions of aircraft maintenance quality engineers to improve flight quality and prevent aviation accidents.

This study attempts a comparison between AHP(Analytic Hierarchy Process) in which the importance weight is structured by individual subjective values and regression model with importance weight based on statistical theory in determining the importance weight of casual model. The casual model is designed by for students’ satisfaction with university, and SERVQUAL modeling methodology is applied to derive factors affecting students’ satisfaction with university. By comparison of importance weights for regression model and AHP, the following characteristics are observed. 1) the lower the degree of satisfaction of the factor, the higher the importance weight of AHP, 2) the importance weight of AHP has tendency to decrease as the standard deviation(or p-value) increases. degree of decreases. the second sampling is conducted to double-check the above observations. This study empirically checks that the importance weight of AHP has a relationship with the mean and standard deviation(or p-value) of independence variables, but can not reveal how exactly the relationship is. Further research is needed to clarify the relationship with long-term perspective.

The paint removal of fighter jets is just as important as the painting, because perfect paint removal ensures the quality of the exterior painting on the aircraft. However, the current conditions for paint removal work of the ROKAF’s are poor. It is identified that the painting process currently implemented by the ROKAF is not only exposed to harmful compounds such as harmful dust and hexavalent chromium, but also consumes a lot of water. Thus, the introduction of advanced facility is considered. This study compares the fighter jets painting removal process currently applied by the Korean Air Force with the improved laser coating removal process of the US Air Force, and conducts an incremental analysis to perform economic analysis for the introduction of advanced facility. Four scenarios were envisioned on the premise of an increase in the number of fighters in the future, incremental analysis shows that laser coating removal method is advantageous in all scenarios. In addition, it is recommended that paint removal cycle keeps the current 12-year and the outsourcing amount to civilian depot is reduced.

In this paper, we investigate the requirements of QPA(Quality Process Audit), which is a process quality audit system for secondary defense contractors, compared with those of DQMS(Defense Quality Management System). And evaluate whether the deployment of QPA meets the DQMS certification requirements through the case example of Company H. The evaluation items of QPA are composed of five categories such as Material Management, Incoming Inspection, Manufacturing Process, Product Evaluation, and Packaging Management. The QPA requirements are mainly related to the chapter 7(support) and chapter 8(operation) of DQMS standards. In this view point, QPA can be expected as an effective audit for suppliers preparing for DQMS certification. In the case example, we evaluate the results and effects of improvement due to QPA and compare it with the case of DQMS. QPA can be used as appropriate quality management standards of secondary and tertiary defense contractors and can provide the basis guidelines for the preparation of implementation steps in DQMS certification.

Six Sigma is a philosophy and systematic methodology for quality improvement. It encourages continuous quality improvement efforts to achieve the ideal goal of 6σ. Sigma(σ) is a statistic representing the standard deviation of the normal distribution, and 6σ level means a level where the tolerance of the specification is six times the standard deviation of the process distribution. In terms of the defective rate, the 6σ level achieves the 0.002 defectives per one million units. However, in the field, the 6σ level is used in the sense of achieving 3.4 defects per one million opportunities, which shows a large gap from the 6σ level in the statistical viewpoint. This is because field practitioners accept a 1.5σ shift of the mean of process when calculating the defective rate under sigma level. It said that the acceptance of 1.5σ shift of the mean is from experience, but there is no research or theoretical explanation to support it logically. Although it is a non-scientific explanation based on experience, considering that there has been no objection to the 1.5σ shift for a long time and it is rather accepted, it is judged that there is a reasonable basis for the 1.5σ shift. Therefore, this study tries to find a reasonable explanation through detective power of control chart via the run-rules to the 1.5σ shift empirically recognized by practitioners.

본 연구는 제도적 이중성(institutional duality)의 관점에서 해외 자회사 자율성의 선행 요인 과 그 성과에 대해 연구하였다. 해외 자회사의 자율성은 자회사가 본사의 영향을 받지 않고 전략적 의사결정을 하고 그 성과에 책임을 질 수 있는 역할을 의미한다. 경영상 본사에서 파생되었으나 물 리적으로 해외에 자리하는 해외 자회사의 자율성에 상반된 영향을 주는 본국과 현지국의 제도적 요 소는 본사의 국제화전략 지향성과 지역 이해관계자 요구이다. 해외 자회사가 직면하게 되는 이러한 상반된 제도적 환경의 자율성에의 효과를 살펴보기 위해, 19개 국가에 진출한 177개 한국기업 해 외 자회사를 대상으로 GLS 분석을 실시하였다. 본사의 국제화전략이 범세계적 통합보다 현지국에 서의 지역별 대응을 지향할수록, 또 지역 이해관계자들의 요구가 강할수록 해외 자회사의 자율성이 높아지는 것으로 분석결과는 나타났다. 해외 자회사들의 자율성이 높을수록 자회사는 해당 지역 이 해관계자 들과의 긴밀한 관계를 통해 필요한 자원을 획득하고 본사로부터 제공된 자원과의 적절한 융합을 통해 자회사만의 독특한 경쟁우위를 창출하며 이것이 종국에 기업 성과를 상승시키는 것으 로 분석결과는 보여주고 있다. 또한, 본사의 국제화전략이 현지국에서의 지역별 대응을 지향할수록 자회사 자율성이 자회사 성과에 미치는 긍정적인 영향력을 강화하는 조절 효과가 있는 것으로 나타 나고 있다. 더 나아가, 자회사 자율성은 지역 이해관계자들의 요구가 자회사 성과로 이어지는 데에 부분 매개의 역할을 하는 것으로 확인되었다. 이러한 결과는 다국적 기업의 본사는 해외 자회사의 운영에 있어 지역별 유연성을 발휘할 필요가 있고, 해외 자회사 또한 본사와 현지국 양 편에서 오 는 제도적 압력의 균형점을 찾기 위해 노력할 필요가 있음을 시사한다.

The Korean Air-Force aircraft maintenance depot paints the exterior of various aircraft, including high-tech fighters. Aircraft exterior painting is a maintenance process for long-term life management by preventing damage to the aircraft surface due to corrosion. The de-painting process is essential to ensure the quality of aircraft exterior paints. However, because the Korean Air-Force’s de-painting process is currently done with sanding or Plastic Media Blasting (PMB) method, it is exposed to harmful dust and harmful compounds and consumes a lot of manpower. This study compares the de-painting process currently applied by the ROK Air-Force and the more improved process of the US Air Force, and performs economic analysis for the introduction of advanced equipment. It aims to provide information that can determine the optimal time to introduce new facilities through Cost-Volume-Profit (CVP) analysis. As a result of the analysis, it was confirmed that the sanding method had the most economical efficiency up to 2 units per year, the PMB method from 3 to 21 units, and the laser method from 22 units or more. In addition, in a situation where the amount of de-painting work is expected to increase significantly due to the increase in fighters in future, BEP analysis was conducted on the expansion of the existing PMB method and the introduction of a new laser method. As a result of the analysis, it was confirmed that it is more economical to introduce the laser method when the amount of work exceeds the PMB work capacity(18 units per year). The paper would helpful to improve the productivity and quality of the Korean Air Force Aircraft maintenance depot through timely changes of facilities in the workplace in preparation for expansion.

Currently, there are two types of trainer in Korea : basic and advanced. Both models have been in operation for more than 10 years, and compared to the early stage of operation, reliability has gradually improved and failure rates have also entered a trend of stabilization. Therefore, it is necessary to extend the maintenance period considering economic feasibility. This study investigates the three maintenance period calculation methods: NAVAIR 00-25-403 [17], DOD, U.S. [4], CERL and US Army [3], with intention to extend the maintenance period of the trainer from current 200 hours to 400 hours. In addition, the maintenance period was calculated by the three methods with actual operational data. Common standards and procedures were established to apply operational data to the existing maintenance period calculation methods, the required reliability indicators were derived, and the maintenance periods was calculated based on the results, additionally, a review on the field applicability of the three maintenance cycles was conducted. An on-site interviews were conducted with the calculation results, and 11 out of the 15 items were expected to be extended by 400 hours. It was suggested that the remaining 4 items could be extended to 400 hours by supplementing the inspection method through additional analysis such as functional analysis, inspection content verification, and site connection.

This paper investigates the stress-reducing preventive maintenance model through numerical experiments. The preventive maintenance model is used to analyze the relationship between related conditions and variables to gain insight into the efficient operation of the system when performing preventive maintenance in real-world situations. Various preventive maintenance models have been developed over the past decades and their complexity has increased in recent years. Increasing complexity is essential to reflect reality, but recent models can only be interpreted through numerical experiments. The stress-reducing preventive maintenance is a newly introduced preventive maintenance concept and can only be interpreted numerically due to its complexity, and has received little attention because the concept is unfamiliar. Therefore, for information purposes, this paper investigates the characteristics of the stress-reducing preventive maintenance and the relationship between parameters and variables through numerical experiments. In particular, this paper is focusing on the economic feasibility of stress-reducing preventive maintenance by observing changes in the optimal preventive maintenance period in response to changes in environmental stress and the improvement factor. As a result, when either the environmental stress or the improve effect of stress-reducing preventive maintenance is low, it is not necessary to carry out the stress-reducing preventive maintenance at excessive cost. In addition, it was found that the age reduction model is more economical than the failure rate reduction model.

This paper is a follow up to the previous study which reveals that smartphone users are divided into three subcategories according to their usage characteristics. In this paper, these groups are called as ‘general’, ‘entertainment’, and ‘work-assistant’, taking into account their respective characteristics. The ‘general’ is a group whose smartphone usage characteristics are not focused on a specific purpose, the ‘entertainment’ is focused on music, internet, SNS, picture, and e-banking, and the ‘work-assistant’ is on work, GPS, diary. Inter-relation between the importance and satisfaction for the purchase determinants to the groups is investigated. In addition, Kano analysis of quality attributes is also performed, which includes quality type, satisfaction/dissatisfaction index, and PCSI (Potential Customer Satisfaction Improvement) index. The analysis result are as follows. Firstly, inter-relation between importance and satisfaction differs by user group. ‘Internet’, ‘Ease of use’, and ‘Performance’ purchase determinants are evaluated as competitive determinants in ‘work-assistant’ user group. Secondly Kano quality types of quality characteristics also differs by user group. ‘Application’ was classified as an attractive (A) types to ‘entertainment’ group and so on. ‘Internet’ ‘Failure/Bug’, ‘Touch response rate’ and ‘Charging’ are located in ‘Nice’ Region of S-PCSI Diagram and have to be considered as strategic quality characteristics. The results of this study is expected to give some helps in establishing a customer tailored quality strategy.

본 연구의 목적은 신흥개발국에 진출한 한국기업 해외 자회사의 현지 CSR 활동과 장기적 성과 간의 관계를 살펴보고, 그 과정에서 현지 공헌의 매개효과를 분석함으로써 현지 CSR 활동과 장기적 성과 간의 경로를 탐색하 는데 있다. 이를 위해 본 연구는 이해관계자 이론과 공유가치창출 관점을 채택하여 해외 자회사의 CSR 활동을 CSR 정책과 CSR 투자로 구분하여 범주화하였다. 신흥개발국에 진출한 147개 한국기업 해외 자회사에 대한 실 증분석 결과, CSR 정책과 CSR 투자는 해외 자회사의 장기적 성과 및 현지 공헌에 정(+)의 유의한 관계를 갖는 것으로 나타났다. 매개효과 분석 결과, 현지 공헌은 현지 CSR 정책과 해외 자회사의 장기적 성과 간의 관계를 ‘부분 매개’하는 반면, 현지 CSR 투자와 해외 자회사의 장기적 성과 간의 관계는 ‘완전 매개’하는 것으로 나타 났다. 이는 현지 CSR 정책의 경우 현지 공헌을 포함한 다양한 경로를 통해 해외 자회사의 장기적 성과에 영향을 미칠 수 있는 반면, 현지 CSR 투자의 경우는 현지 공헌의 경로를 통해서만 기업의 장기적 성과에 영향을 미칠 수 있음을 시사한다. 본 연구의 결과는 다국적 기업 해외 자회사의 입장에서 1, 2차 현지 이해관계자들의 압박에 효과적으로 대응하면서 현지에서의 공유가치창출을 통해 지속가능경영을 수행해 나가기 위해서는 CSR 정책과 CSR 투자가 함께 이루어져야 함을 보여주고 있다. 이러한 결과는 해외 자회사의 CSR 정책과 CSR 투자가 병행 될 때에야 진정성 있는 CSR 활동으로 현지국 이해 관계자에게 다가갈 수 있음을 시사한다.