• The Korean Journal of Applied Statistics
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• v.24 no.4
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• pp.587-595
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• 2011

Credit scoring is an objective and automatic system to assess the credit risk of each customer. The logistic regression model is one of the popular methods of credit scoring to predict the default probability; however, it may not detect possible nonlinear features of predictors despite the advantages of interpretability and low computation cost. In this paper, we propose to use a generalized partially linear model as an alternative to logistic regression. We also introduce modern ensemble technologies such as bagging, boosting and random forests. We compare these methods via a simulation study and illustrate them through a German credit dataset.

• 한국IT서비스학회:학술대회논문집
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• 2002.06a
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• pp.381-386
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• 2002

급변하는 정보화 사회에서, 철도 물류 정보 분야는 업무 자동화에 대한 인식 부족, 데이터 실시간 처리 불가, 열악한 사용자 환경 등으로 인해 활성화되지 못하였다. 이러한 상황을 극복하기 위해 인터넷을 기반으로 하며 차세대 인터넷 표준으로 알려진 XML을 적용한 철도 물류 정보 연계 시스템을 구축하였다. 구축된 시스템은 기존의 철도 물류 정보 시스템의 기능과 성능을 개선하여 사용자에게 안정되고 편리한 서비스를 제공하기 위한 구조로 설계되었다. 또한 기존의 2-tier 형태의 WEB 구조를 3-tier 형태로 하여 보안이 강화된 구조로 하였으며, 새로운 인터넷 표준으로 각광받는 XML Schema와 XSL을 적용하여 앞서 나가는 철도 물류 정보 시스템이 되도록 하였다.

• International Commerce and Information Review
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• v.12 no.2
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• pp.267-290
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• 2010

The Kaes$\breve{o}$ng Industrial Park(KIP) is being developed in the region, as a collaborative economic development with South Korea. KIP construction started in June 2003, and in August 2003 North and South Korea ratified four tax and accountancy agreements to support investment. Pilot phase construction was completed in june 2004, and the KIP opened in December 2004. In the KIP's initial phase, 15 South Korean companies constructed manufacturing facilities. Three of the companies had started operations by march 2005. First phase plans envisaged participation by 250 South Korean companies from 2006, employing 100,000 people by 2007. Based on the 2009, 117 factories were employing approximately 41,000 north' workers and 1,000 south' staff. The industrial park is seen as a way for South Korean companies to employ cheap labour that is educated, skilled and speaks Korean which would make communication considerably easier. However the zone still faces a number of obstacles. In the view point of these obstacles, especially this study focused on the complementary issues for the improvement of trade goods management systems between South and North Korea. At the result of this study, it is suggested that, i) to establish portal system based on single window, ii) strengthen user-interface hands of logistic facilities, iii) stable foundations of trade and/or logistic management systems, iv) networking of IT infrastructure with South and North Korea, and so on.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.302-305
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• 2004

The aim of this study is to apply and crossvalidate a spatial logistic multiple-regression model at Boun, Korea, using a Geographic Information System (GIS). Landslide locations in the Boun area were identified by interpretation of aerial photographs and field surveys. Maps of the topography, soil type, forest cover, geology, and land-use were constructed from a spatial database. The factors that influence landslide occurrence, such as slope, aspect, and curvature of topography, were calculated from the topographic database. Texture, material, drainage, and effective soil thickness were extracted from the soil database, and type, diameter, and density of forest were extracted from the forest database. Lithology was extracted from the geological database and land-use was classified from the Landsat TM image satellite image. Landslide susceptibility was analyzed using landslide-occurrence factors by logistic multiple-regression methods. For validation and cross-validation, the result of the analysis was applied both to the study area, Boun, and another area, Youngin, Korea. The validation and cross-validation results showed satisfactory agreement between the susceptibility map and the existing data with respect to landslide locations. The GIS was used to analyze the vast amount of data efficiently, and statistical programs were used to maintain specificity and accuracy.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.42-54
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• 2016

A hybrid color and grayscale images encryption scheme based on the quaternion Hartley transform (QHT), the two-dimensional (2D) logistic map, the double random phase encoding (DRPE) in gyrator transform (GT) domain and the three-step phase-shifting interferometry (PSI) is presented. First, we propose a new color image processing tool termed as the quaternion Hartley transform, and we develop an efficient method to calculate the QHT of a quaternion matrix. In the presented encryption scheme, the original color and grayscale images are represented by quaternion algebra and processed holistically in a vector manner using QHT. To enhance the security level, a 2D logistic map-based scrambling technique is designed to permute the complex amplitude, which is formed by the components of the QHT-transformed original images. Subsequently, the scrambled data is encoded by the GT-based DRPE system. For the convenience of storage and transmission, the resulting encrypted signal is recorded as the real-valued interferograms using three-step PSI. The parameters of the scrambling method, the GT orders and the two random phase masks form the keys for decryption of the secret images. Simulation results demonstrate that the proposed scheme has high security level and certain robustness against data loss, noise disturbance and some attacks such as chosen plaintext attack.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.3
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• pp.63-68
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• 2007

The LRA(Logistic Regression Analysis) conducts a quantitative analysis by collecting a lot of samples and the AHP(Analytic Hierarchy Program) makes use of expert decision influenced by subjective judgment to a certain degree. This study is to suggest a combination method in mapping landslide hazard by giving equal weight for the result of LRA and AHP. Topographic factors(slope, aspect, elevation), soil dram, soil depth and land use were adopted to classify landslide hazard areas. The three methods(LRA, AHP, the combined approach) was applied to a $520km^2$ region located in the middle of South Korea which have occurred 39 landslides during 1999 and 2003. The suggested method showed 58.9% matching rate for the real landslide sites comparing with the classified areas of high-risk landslide While LRA and AHP Showed 46.1% and 48.7% matching rates respectively. Further studies are recommended to find the optimal combining weight of LRA and AHP with more landslide data.

• Journal of Applied Reliability
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• v.18 no.1
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• pp.1-7
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• 2018

Purpose: Maintaining appropriate operational availability (Ao) is a key element of combat victory, but estimates vary according to estimation methods. The purpose of this study is to improve the accuracy of estimating operational availability by tracing the changes of the weapon system's failure rate, repair rate, and the level of logistic support. Methods: In order to track the change in the operating availability, the MDT (mean down time) is modeled by adding the repair time and the ALDT (administration and logistic delay time) to the service time. Results: Using the field data of the weapon system A operated by the ROKAF, the failure rate follows a non-homogeneous Poisson process that changes with time, and it is modeled considering the changing repair rate and the logistic support time. Conclusion: The accuracy of the analytical results was verified by comparing the actual operating data with the estimated availability. The results of this study can be used to track and evaluate the availability in a realistic situation where the failure rate and maintenance rate continuously change in operating environment.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.64-64
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• 2003

The aim of this study is to apply and verify of logistic regression at Janghung, Korea, using a Geographic Information System (GIS). Landslide locations were identified in the study area from interpretation of IRS satellite images, field surveys, and maps of the topography, soil type, forest cover, geology and land use were constructed to spatial database. The factors that influence landslide occurrence, such as slope, aspect and curvature of topography were calculated from the topographic database.13${\times}$1ure, material, drainage and effective soil thickness were extracted from the soil database, and type, diameter and density of forest were extracted from the forest database. Land use was classified from the Landsat TM image satellite image. As each factor's ratings, the logistic regression coefficient were overlaid for landslide susceptibility mapping. Then the landslide susceptibility map was verified and compared using the existing landslide location. The results can be used to reduce hazards associated with landslides management and to plan land use and construction.

• Journal of Korea Port Economic Association
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• v.21 no.1
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• pp.45-58
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• 2005

The purpose of this study is to consider the problem on pursuit of logistics strategy by our international shipping company in international shipping business under the said circumstance due to the open international shipping market and to suggest the logistics strategy for the consideration of the logistics competition under new international shipping circumstances. The results of empirical analysis are mentioned as follows; First, it shall be considered to maintain the size of company bigger than a certain capability so that it may obtain the superior competition of logistics. Second, as there are the plus correlations between the competition of logistics and the logistic support, it is necessary to pursuit the upgrade service with using EDI system and making up the complex shipping and integrated logistics system in general. Third, with the rationalization of finance policy and the profitable management of shipping company the ratio of net worth can be raised and it can be achieved to make the sound financial structure as reducing the excessive debt ratio. Fourth, it can be effort continuously to perform the investment for the infrastructure of logistics support & the institutional supplement so that it may achieve to increase the efficiency of logistic support at pier and to reduce the cost of logistic support.

• The Journal of Information Systems
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• v.19 no.1
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• pp.63-77
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• 2010

Strategic agility plays a critical role in sustaining competitive advantage in the turbulent environment. This study examines the relationship between a logistics information system and, strategic agility through the analysis of "H" corporation case. The results of case study showed that the introduction of logistic information system facilitates the degree of strategic sensitivity, collective commitments and resource fluidity, which are primary elements of strategic agility. This study gives an insight to the practitioners who attempt to create strategic agility through the implementation of logistic information systems.