• 한국도로학회논문집
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• 제15권3호
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• pp.93-101
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• 2013

PURPOSES : This study is to investigate the relationship of socioeconomic characteristics and road network structure with traffic growth patterns. The findings is to be used to tweak traffic forecast provided by traditional four step process using relevant socioeconomic and road network data. METHODS: Comprehensive statistical analysis is used to identify key explanatory variables using historical observations on traffic forecast, actual traffic counts and surrounding environments. Based on statistical results, a multiple regression model is developed to predict the effects of socioeconomic and road network attributes on traffic growth patterns. The validation of the proposed model is also performed using a different set of historical data. RESULTS : The statistical analysis results indicate that several socioeconomic characteristics and road network structure cleary affect the tendency of over- and under-estimation of road traffics. Among them, land use is a key factor which is revealed by a factor that traffic forecast for urban road tends to be under-estimated while rural road traffic prediction is generally over-estimated. The model application suggests that tweaking the traffic forecast using the proposed model can reduce the discrepancies between the predicted and actual traffic counts from 30.4% to 21.9%. CONCLUSIONS : Prediction of road traffic growth patterns based on surrounding socioeconomic and road network attributes can help develop the optimal strategy of road construction plan by enhancing reliability of traffic forecast as well as tendency of traffic growth.

• Journal of Electrical Engineering and Technology
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• 제7권1호
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• pp.23-33
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• 2012

The current paper deals with a new live-line insulator inspection tool system that will be used by the Korea Electric Power Corporation for its 154 kV power transmission lines in 2011. Unlike the existing contact type tools, the developed inspection tool automates parts of the insulator inspection process using a sensor and an actuator. The tool sustains its weight independently, not by a lineman. In addition, the inspection tool measures the insulation resistance of an insulator together with its distribution voltage, thus providing more information for analysis and diagnosis. Such characteristics improve the system's operation efficiency, measurement reliability, and usability. We confirmed its effectiveness through live-line field tests with actual power transmission lines.

• International Journal of Reliability and Applications
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• 제7권1호
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• pp.71-77
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• 2006

The market for second hand products has been growing for a variety of reasons (e.g., new products appearing at a faster rate and the expected life of products increasing due to rapid advances in technology). The demand for warranties for second-hand products has been growing along with the growth of the market for second-hand products. Warranty for new products (consumer durables, industrial and commercial, and specialized defense products) has received a lot of attention. In contrast, warranties for second-hand product have received very little attention. Often, dealers of second-hand product such as cars offer 2D-warranties (Year and Kilometers). The expected warranty cost associated with a second-hand product for 2D-Policies is a function of the age of the item and its usage (as it affects failures over the warranty period), the warranty terms and the servicing strategy used by the dealer. This paper deals with development of models for warranty cost analysis along with the decision on sale price and warranty cover for 2D-Warranty policies associated with sale of second-hand products.

• Journal of Information Technology Applications and Management
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• 제31권1호
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• pp.27-43
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• 2024

This study investigated technological and managerial barriers in technology startups through a survey of 151 companies, yielding 118 responses (78.1% response rate). Factor and multivariate analyses identified two distinct barriers: technological and managerial. Reliability analysis validated the measurement tool. Using MANCOVA, 12 hypotheses were tested, incorporating six independent variables. Results revealed significant disparities in technological and managerial barriers based on establishment type, commercialization goals, growth stage, and commercialization stage, with 5 hypotheses supported. This study highlights the crucial role of these variables in understanding barriers within technology-based startups.

• 유통과학연구
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• 제21권2호
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• pp.35-43
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• 2023

Purpose: As Thailand seeks to become a regional startup hub, Thai startups have been acquiring growth and scalability in the last ten years. Hence, this paper examines influential factors in Thailand's growth of logistics tech startups. The conceptual framework incorporates sensing user needs, sensing technological options, conceptualizing, scaling, and stretching, co-producing, and orchestrating, business strategy, strategic flexibility, and startup growth. Research design, data, and methodology: The quantitative method was applied to distribute the questionnaire to 500 managers and above in logistics tech startups in Thailand. The sampling techniques involve judgmental, convenience, and snowball samplings. Before the data collection, The Item Objective Congruence (IOC) Index and pilot test (n=45) were employed for content validity and reliability. The data were mainly analyzed by Confirmatory Factor Analysis (CFA) and Structural Equation Model (SEM). Results: The findings revealed that sensing technological options, scaling, and stretching, co-producing, and orchestrating, and business strategy significantly influence the growth of startups in Thailand. Nevertheless, sensing user needs, conceptualizing, and strategic flexibility have no significant relationship with startup growth. Conclusions: For Thailand to accelerate its digital economy driven by tech startups, firms must emphasize influential factors to accelerate growth by providing the right tech solutions for people's lives.

• 산경연구논집
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• 제10권12호
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• pp.43-55
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• 2019

Purpose : With the proliferation of O2O platform services that combine offline and online services, many startups are fiercely competing to lead services in the O2O service market. While the prospects for growth in the O2O service market are optimistic because of the close convenience to life, startups can achieve corporate performance only through close cooperation and partnership with suppliers. The purpose of this study is to verify the effect of O2O-based startups' and suppliers' cooperation in supply chain management on SCM performance through supply chain partnerships and startup satisfaction with suppliers. Research design, data, methodology : Data were collected from O2O service-based startups and hypotheses were verified through frequency analysis, exploratory factor analysis, reliability analysis, confirmatory factor analysis, feasibility analysis, and structural equation path analysis. In addition, the mediating effects of supply chain partnerships and startup satisfaction on suppliers were verified. Results : As a result of this study, IT utilization of the O2O startup cooperation method affects the financial perspective of supply chain partnership and SCM performance. The contract implementation of the cooperation method had an impact on the financial and innovation growth perspectives of the SCM performance, and the communication of the cooperation method had an effect on the supply chain partnership, startup satisfaction in the supply chain, and the innovation growth perspective of the SCM performance. Supply chain partnerships had an impact on the financial, innovation growth, and customer perspectives of SCM performance and startup satisfaction within the supply chain had a significant effect on innovation growth and customer perspectives. Conclusions : The implications of this study identified the factors that can improve SCM performance through the cooperation method of O2O startup, supply chain partnership and startup satisfaction with suppliers, and it is significant that the causal relationship was identified by the structural model through the supply chain cooperation factors derived by characteristics. Based on the empirical results, as the services of O2O startups grow, it is expected that empirical research and practical activation of academia should be considered as important in the cooperation of the supply chain.

• 산업진흥연구
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• 제9권1호
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• pp.241-248
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• 2024

본 연구는 중국 대학생을 대상으로 행복과 희망이 성장 마인드셋과 학성성취의 관계에서 이중매개하는지를 확인하는데 연구의 목적이 있다. 자료는 중국 Guangdong지역의 한 대학교에서 유의표집한 대학생 337명을 대상으로 설문조사를 통하여 수집하였다. 수집한 자료는 SPSS PC+ Win ver. 25.0과 SPSS PROCESS macro ver. 4.2를 활용하여 분석하였다. 적용된 통계방법은 빈도분석, 신뢰도 분석, 상관분석 및 이중매개효과 분석이었다. 연구의 결론은 다음과 같다. 첫째, 행복, 희망, 성장 마인드셋과 학성성취 모두 정적인 유의미한 상관관계를 보였다. 둘째, 대학생의 행복과 희망은 성장 마인드셋과 학업성취의 관계에서 이중매개하였다. 이러한 결과를 토대로 본 연구는 대학생들의 성장 마인드셋뿐만이 아니라 행복 및 희망을 활용하여 학업성취를 증진할 수 있는 방안을 제언하였다.

• 한국해양공학회지
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• 제13권3호통권33호
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• pp.36-48
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• 1999

Fatigue life and crack retardation behavior after penetration were experimentally examined using surface pre-cracked specimens of aluminium alloy 5083. The Wheeler model retardation parameter was used successfully to predict crack growth behavior after penetration. By using a crack propagation rule, the change in crack shape after penetration can be evaluated quantitatively. Advanced, waveform-based acoustic emission (AE) techniques have been successfully used to evaluate signal characteristics obtained form fatigue crack propagation and penetratin behavior in 6061 aluminum plate with surface crack under fatigue stress. Surface defects in the structural members are apt to be origins of fatigue crack growth, which may cause serious failure of the whole structure. The nondestructive analysis on the crack growth and penetration from these defects may, therefore, be one of the most important subjects on the reliability of the leak before break (LBB) design. The goal of the present study is to determine if different sources of the AE could be identified by characteristics of the waveforms produced from the crack growth and penetration. AE signals detected in four stages were found to have different signal per stage. With analysis of waveform and power spectrum in 6061 aluminum alloys with a surface crack, it is found to be capabilities on real-time monitoring for the crack propagation and penetration behavior of various damages and defects in structural members.

• 아태비즈니스연구
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• 제8권2호
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• pp.15-30
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• 2017

This study analyzes the relationship between income inequality and economic growth. Gini coefficient (market income), the deciles income inequality index and per capita real GDP were analyzed. Furthermore, various cointegration tests were tried to improve the reliability of the test results. From the weak exogeniety test of between per capita real GDP and the Gini coefficient (market income), per capita real GDP has a weak exogeneity while the Gini coefficient is endogenous. From the various cointegration tests, we found out that there is a cointegration between Gini coefficient and per capita real GDP. Moreover, it is estimated that per capita real GDP has a positive effect on the Gini coefficient (market income). In the VAR Granger causal analysis, per capita real GDP affects the Gini coefficient (market income), but it is difficult to say that the Gini coefficient (market income) always has an effect on per capita real GDP. Also, the impulse-response function of the VAR model shows that per capita real GDP temporarily reduces the Gini coefficient (market income), and then increases it over time. Accordingly, it is necessary for the policies to improve not only the distribution structure but also income distribution through economic growth.

• 한국항공우주학회지
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• 제39권4호
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• pp.306-313
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• 2011

항공기 부품에 대한 손상허용해석은 구조적 안전성 및 신뢰성 보장을 위해 면밀히 평가되어야한다. 손상허용기법은 항공기 주구조의 피로 설계기법으로 초기균열의 존재를 고려하여 피로수명을 산정한다. 따라서 손상허용해석에서는 피로 균열성장 수명의 계산이 요구되며, 이를 바탕으로 부품의 점검시간 및 교체주기를 결정한다. 본 논문에서는 형상이 복잡한 터빈 휠에 대하여 손상허용해석을 수행하였다. 형상이 복잡한 구조의 균열성장수명평가 시에는 주요 변수인 응력확대계수의 식을 알기 어려워, 이를 유한요소해석으로 계산하므로 많은 시간이 요구된다. 이러한 문제를 해결하고자 특정 균열길이에 대한 응력확대계수를 유한요소해석으로 계산하고, 생성된 데이터의 회귀분석을 통해 응력확대계수의 근사모델을 생성하였다. 균열성장 수명은 근사모델의 적분으로 계산하였으며, 근사모델을 사용하여 균열성장 수명평가와 손상허용해석의 효율을 높일 수 있었다.