• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2006.05a
• /
• pp.121-126
• /
• 2006

본 연구는 반도체 산업의 공정에서 자동화를 위한 Solution 개발에 초점을 두었다. Spec-out(불량)이 발생하였을 경우에 엔지니어가 원인을 분석하고 조치를 취하던 이전의 방식을 탈피하여 Expert Knowledge Base System의 On-Line방식으로 전환하고자 한다. 이러한 시스템을 구축하기 위해 공정과 계측간에 발생하는 파라메터들의 상관관계를 수학적으로 도출하였으며, 상관관계들을 이용하여 이탈 발생시 처리를 하기 위한 Rule을 구성하였다. 그리고 이 Rule들을 바탕으로 이탈발생의 원인을 분석하는 추론 시스템을 구성하여 즉각적이고 신속하게 처리를 하기 위한 이탈처리 분석 시스템을 구성하는 방법을 연구하였다.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.05a
• /
• pp.694-697
• /
• 2004

최근 빠르게 성숙되고 있는 시장과 경쟁적 환경으로 인해 고객 유지에 대한 중요성이 증대되고 있다. 이는 기존 고객을 유지하는 것이 비용 면에서 저렴할 뿐 아니라, 고객 충성도나 구전효과가 같은 기타 부수적인 이득을 획득할 수 있다는 측면에서 유리하기 때문이다. 본 논문은 고객의 이탈 가능성을 미리 예측하고 이를 사전에 방지할 수 있는 고객 유지 절차를 제시하고 있다. 이탈고객의 탐지 및 방지를 위해서는 기존의 인구통계학적 자료 외에도 웹로그, 구매 Database 등의 대용량의 고객 행위 데이터에 대한 분석이 요구되기 때문에 데이터 마이닝 기법의 활용이 필수적이다. 그러나 대부분의 데이터 마이닝 연구는 예측 및 분류의 정확성이 높은 모델을 개발하는데 초점이 맞추어져 있으며, 고객의 행위를 이해하고 바람직한 방향으로 유도하고자 하는 연구는 지극히 부족한 상황이다. 그러므로 본 논문은 다양한 데이터마이닝 기법을 통합하여 잠재 이탈고객을 탐지하고, 기존 연구에서 간과하고 있던 비용적 측면을 고려한 이탈 방지 절차를 제시하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.12
• /
• pp.1217-1222
• /
• 2012

A wall flow sensor has been used for feedback flow control and wall shear stress measurement. In this study, we developed a new wall flow sensor by combining the PIV algorithm and the micro image sensor used in an optical mouse. The feasibility of the wall flow sensor was investigated by using simulated fluid flow experiments. Compared with the quadrature signal from imaging devices, the accuracy of the wall flow velocity measurement was improved and the dynamic range increased. In addition, the depth information of particles was also measured by using the defocusing imaging technique.

• Journal of Korean Society of Transportation
• /
• v.30 no.2
• /
• pp.43-52
• /
• 2012

A lane departure warning system (LDWS) is an effective technology-based countermeasure for preventing traffic crashes as it provides warning information to drivers. Understanding the characteristics of perception and satisfaction levels on LDWS is fundamental for deriving better performance and functionality enhancements of the system. The purpose of this study is to evaluate the user satisfaction of LDWS. A survey to collect user perception and user preference data was conducted. Both cross-tabulation analysis and binary logistic regression technique were adopted to identify the factors affecting user satisfaction for LDWS. The results revealed that the accuracy and timeliness of warning information was significant for evaluating the effectiveness of LDWS. In particular, the warning accuracy at a curve segment on the road was the most dominant factor affecting user satisfaction. The outcome of this study would be valuable in evaluating and designing LDWS functionalities.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.4
• /
• pp.68-80
• /
• 2016

This study proposes the traffic prediction and optimal traffic control system based on cell transmission model and genetic algorithm in cloud environment. The proposed prediction and control system consists of four parts. 1) Data preprocessing module detects and imputes the corrupted data and missing data points. 2) Data-driven traffic prediction module predicts the future traffic state using Multi-level K-Nearest Neighbor (MK-NN) Algorithm with stored historical data in SQL database. 3) Online traffic simulation module simulates the future traffic state in various situations including accident, road work, and extreme weather condition with predicted traffic data by MK-NN. 4) Optimal road control module produces the control strategy for large road network with cell transmission model and genetic algorithm. The results show that proposed system can effectively reduce the Vehicle Hours Traveled upto 60%.

• Korean Journal of Childcare and Education
• /
• v.11 no.6
• /
• pp.59-78
• /
• 2015

This study aims to explore the relationship between North Korean refugee mothers' perceived home psychological characteristics and ego-resilience of their young children focusing on moderating effect of social support. For this purpose, we sampled 96 North Korean refugee mothers with 3-5 year old children. Home psychological characteristics consisting of family strength, family environment and family functioning, social support, and ego-resilience was analyzed by Pearson correlation analyses and hierarchical regression method. The results of this study were as follows. First, there is a significant correlation between North Korean refugee mothers' perceived home psychological characteristics and ego-resilience of their young children. Second, the perceived factors by North Korean refugee mothers of home psychological characteristics explained their young children's self-resilience 73.4% of the time and social support had a significant moderating effect. These results suggest that more effective social support to North Korean refugees has to be offered. Not only financial but emotional support is also needed.

• Applied Microscopy
• /
• v.26 no.4
• /
• pp.479-487
• /
• 1996

Thin epilayer structures of GaAs/AlAs/InGaAs, grown by Molecular Beam Epitaxy, were investigated by high resolution transmission electron microscopy, Image in the [110] zone axis was taken and compared with the calculated images. The supercell structure which contains GaAs, AlAs and InGaAs layers was designed and was employed in the image calculation with MacTempas computer program. Good agreement was shown between experimental image and a set of calculated images with varying defocus and sample thickness.

• Journal of Navigation and Port Research
• /
• v.48 no.4
• /
• pp.303-309
• /
• 2024

This study examines the effects of wave pressure on a vertical wall due to armor block failure at the front of a caisson, using a 2-D hydraulic model to simulate three types of armor block cross-sections. Additionally, the hydraulic characteristics of two cross-sections that replicated the armor blocks' failure, based on complete cross-sections, were compared. Moreover, quantitative analysis indicated that in the cross-section where the displacement of the armor block was recreated, wave run-up( ) increased by an average of 73%, the sum of dimensionless wave pressures increased by 28%, and converted wave force rose by 33%. These findings underscore the need for countermeasures in the event of armor block failure.

• Informatization Policy
• /
• v.25 no.2
• /
• pp.67-83
• /
• 2018

This study explores how social media influences individual's social development and well-being. Social media is discussed as an effective tool when individuals lacking social and psychological resources are trying to expand their social networks. This study focuses on the social media use of North Korean defectors, who, in general, have closed social media networks in the South Korean society. This study tries to analyze empirically the effect of social media use on North Korean defectors' satisfaction with our society. In particular, this study focuses on how the use of social media influences satisfaction with their life in South Korea at different levels of their emotional states. This study explores that the relationship between social media and satisfaction with their life in South Korea varies based upon the degree of self-esteem and anxiety. This study expects that social media might provide greater benefits for those who are experiencing low self-esteem and high anxiety. In addition, this study conducts the same analysis for the general public and then compares its results with the survey on North Korean defectors. According to the results of North Korean defectors' survey, the impact of social media use on satisfaction with their life in South Korea was greater for those with high anxiety than for those with low anxiety. Meanwhile, the impact was greater for those with high self-esteem than for those with low self-esteem.

• Journal of Korea Society of Industrial Information Systems
• /
• v.22 no.6
• /
• pp.9-16
• /
• 2017

An Algorithm for Lane Detection and Lane Departure Warning for a Vehicle Driving on Roads is proposed in This Paper. Using Images Obtained from On-board Cameras for Lane Detection has Some Difficulties, e.g. the Increase of Fault Detection Ratio Due to Symbols on Roads, Missing Yellow Lanes in the Tunnel due to a Similar Color Lighting, Missing Some Lanes in Rainy Days Due to Low Intensity of Illumination, and so on. The Proposed Algorithm has been developed Focusing on Solving These Problems. It also has an Additional Function to Determine How much the Vehicle is leaning to any Side between The Lanes and, If Necessary, to Give a Warning to a Driver. Experiments Using an Image Database Built by Collecting with Vehicle On-board Blackbox in Six Different Situations have been conducted for Validation of the Proposed Algorithm. The Experimental Results show a High Performance of the Proposed Algorithm with Overall 97% Detection Success Ratio.