• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.601-612
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• 2005

In mountainous area, Two parallel tunnels have been usually recognized as a road tunnel which has benefits in aspects of cost and stability. However, Design and construction of 2-Arch road tunnel are growing recently due to environmental destruction, compensation of land and difficulty of route separation. As studies are mainly undergoing on only guaranteeing stability and developing a waterproofing-drainage system to avoid water leakage through comprehension for characteristics of 2-arch tunnel behaviors, there is a tendency to evaluate quantity of support by empirical method with a tunnel which has a complicated cross-section and lack of construction ability. In this study, therefore, we made a plan of tunnel cross-section which had shown good construction ability and developed the waterproofing-drainage system which is able to solve the water leakage problem fundamentally by analyzing precedented 2-arch tunnels and investigating their sites in and out of nation. We also determined fixed quantity of support by a large-scale model test and numerical analysis. We want to contribute to 2-arch tunnel design hereafter introducing design procedure and method applied here.

• Structural Engineering and Mechanics
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• v.43 no.4
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• pp.459-473
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• 2012

Post-tensioned concrete voided slab girders are widely used in highway bridge constructions. To obtain greater section hollow rate and reduce the self-weight, the plate thickness of slab girders are designed to be small with the adoption of flat anchorage system. Since large prestress is applied to the anchor end section, it was found that longitudinal shear cracks are easy to occur along the voided slab girder. The reason is the existence of great shearing effect at the junction area between web and bottom (top) plate in the anchor end section. This paper focuses on the longitudinal anti-cracking problem at the anchor end of post-tensioned concrete voided slab girders. Two possible models for longitudinal anticracking analysis are proposed. Differential element analysis method is adopted to derive the solving formula of the critical cracking state, and then the practical analysis method for longitudinal anti-cracking is established. The influence of some factors on the longitudinal anti-cracking ability is studied. Results show that the section dimensions (thickness of bottom, web and top plate) and prestress eccentricity on web plate are the main factors that influence the anti-cracking ability. Moreover, the proposed method is applied into three engineering examples to make longitudinal anti-cracking verification for the girders. According to the verification results, the design improvements for these girders are determined.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.2
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• pp.81-94
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• 2018

The purpose of this study is to substantiate the affecting factors of informal learning outcomes for professions in various dimensions of an individual and organization. In specific, the study analyzed the effects of learning motivation, job characteristics, and a supportive learning environment which have on task-related knowledge acquisition, adapting to organization and understanding contexts, relationship formation, and improving self-development-ability. The participants of the study were 261 professionals working at four major accounting firms in South Korea. Multiple regression models were applied step by step for analysis. In this study, the informal learning of professionals working at four major accounting firms is influenced by various factors of learning motivation, job characteristics, and a supportive learning environment. The detailed analysis results were as follows. Firstly, peer-support showed the most positive effect on task-related knowledge acquisition. Secondly, for adapting to organization and understanding contexts, task autonomy showed the greatest effect. Thirdly, peer-support was found to be the most important factor for relationship formation. Fourthly, for improving self-development ability, learning goal orientation showed to be the most important factor. The various factors facilitated the professional learning by empirical identification. The study presented practical implications for creating an effective informal learning support environment.

• Journal of Korean Home Economics Education Association
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• v.2 no.1
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• pp.29-44
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• 1990

The purpose of this study is to provide more efficient teaching method in teaching home Economics in High School. For this study, total 205 girls’high school students in the 2nd grade, among whom 103 students of 2 classes were in Chonju and 102 students of another 2 classes in Kunsan, were selected. Each one classes apiece of two areas were control group. Lessons on laundering were given to students in Chonju and lessons on arrangement of clothing were given to ones in Kunsan. The project Method of education was applied to the experimental group and the cramming system of education was applied to the control group. The difference of two groups were statistically analysed by t-test after the written examination, Practitude, creative ability and interest test. The results of this study are ; 1. The experimental group was higher in practical attitude, creative ability and interest than the control group. 2. Teaching through project method will give changes to the students’attitude toward their household affaires. 3. Teaching-learning method will be improved if lessons applied by project method is given, as the recognisable effect rises through the positive way of thinking and empirical method.

• The Journal of Korean Institute for Practical Engineering Education
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• v.2 no.2
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• pp.113-119
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• 2010

The objective of this study is to perform the systematic research and to develop programs for improving the teaching abilities of vocational teachers, so that they can cope with the variant educational condition in accordance with the change of paradigm. Especially vocational teachers who engage in technical education can acquire new knowledge and techniques as well as grasp the trend of the new technologies required in industrial fields. In this study preliminary research for the capabilities of vocational teachers was held and the feasibility was investigated. Upon these investigations the essential elements for the improvement of vocational teachers' capabilities were derived. These will be used as preliminary data for operating curricula.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.173-181
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• 2012

The education method using visual materials such as video contents is getting more attentions in the education field. This study researched how undergraduate students perceive the objective of education method utilizing video contents, what types of education using video contents they put a great importance on, and what kinds of correlations exist between the video contents method and the ability of discussing about a topic in essay-type examinations. With in-depth interviews with undergraduate students, the results showed that video contents was perceived as one of the attractive teaching methods increasing students' comprehension of lectures. Also, students evaluated that the video contents method could provide an opportunity to be exposed to the vivid scene of the journalistic environment and make them learn practical cases at second hand. Moreover, they perceived the video contents method as a very effective learning method improving their ability to discuss about a topic in essay-type exams.

• Food Science of Animal Resources
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• v.34 no.6
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• pp.808-814
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• 2014

This study investigated the effect of gum arabic (GA) combined with microbial transglutaminase (TG) on the functional properties of porcine myofibrillar protein (MP). As an indicator of functional property, heat-set gel and emulsion characteristics of MP treated with GA and/or TG were explored under varying NaCl concentrations (0.1-0.6 M). The GA improved thermal gelling ability of MP during thermal processing and after cooling, and concomitantly added TG assisted the formation of viscoelastic MP gel formation. Meanwhile, the addition of GA decreased cooking yield of MP gel at 0.6 M NaCl concentration, and the yield was further decreased by TG addition, mainly attributed by enhancement of protein-protein interactions. Emulsion characteristics indicated that GA had emulsifying ability and the addition of GA increased the emulsification activity index (EAI) of MP-stabilized emulsion. However, GA showed a negative effect on emulsion stability, particularly great drop in the emulsion stability index (ESI) was found in GA treatment at 0.6 M NaCl. Consequently, the results indicated that GA had a potential advantage to form a viscoelastic MP gel. For the practical aspect, the application of GA in meat processing had to be limited to the purposes of texture enhancer such as restructured products, but not low-salt products and emulsion-type meat products.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.205-211
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• 2002

The purpose of this paper is 1) to extract managerial factor into each cell which is classified by the characteristic grill of new products 2) to construct a management model of new product development for korean companies. For this purpose, the characteristic grill of new products is classified by which is market/technology sphere. Moreover the focus of this analysis is on examination of success/failure factors, which have an important effect upon new product success or failure. The variables for this study were selected from literature survey and pre-interview was implemented specially. The subject of study was project leaders of electronics industry where have taken the leading part in product development activities in Korean manufacturing industries. Enquete survey was conducted in each firm and project managers were asked to respond. Conclusion of this study based on many significant results gained by the various multi-variate analysis are summarized as follows. First, it can he noted that success/failure factors are different by each classified model and characteristic grill of a new product. Second, it has been identified that the important factors of success products were technical & management support and market ability, the important factor of failure product were lacking in ability of technical development and R&D management system construction. This paper presents some useful guidelines in strategic and managerial aspects for development of new products. Concurrently, the model of this study should be a great practical approach for application of actual affairs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2240-2250
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• 2016

MIFARE Classic is the most popular contactless smart card, which is primarily used in the management of access control and public transport payment systems. It has several security features such as the proprietary stream cipher Crypto 1, a challenge-response mutual authentication protocol, and a random number generator. Unfortunately, multiple studies have reported structural flaws in its security features. Furthermore, various attack methods that target genuine MIFARE Classic cards or readers have been proposed to crack the card. From a practical perspective, these attacks can be partitioned according to the attacker's ability. However, this measure is insufficient to determine the optimal attack flow due to the refined random number generator. Most card-only attack methods assume a predicted or fixed random number, whereas several commercial cards use unpredictable and unfixable random numbers. In this paper, we propose optimal MIFARE Classic attack procedures with regards to the type of random number generator, as well as an adversary's ability. In addition, we show actual attack results from our portable experimental setup, which is comprised of a commercially developed attack device, a smartphone, and our own application retrieving secret data and sector key.

• Management & Information Systems Review
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• v.15
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• pp.51-69
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• 2004

Local universities are faced with rapid environmental changes in 2000's. Therefore local universities are required to research for more specialized marketing strategy such as positioning strategy. The objectives of this study are to examine what are the most important university images and image position of 7 universities'. In order to this study, 276 questionnaires collected from university in Busan area are analyzed by t-test, anova. The results of this study are summarized as follows (1) the most important university images are ranked in the order 1) prospect of getting employment(4.78), 2) possibility of development (4.35), 3) confidence(4.31), 4) research ability(3.97). It is true that practical images get high grade, traditional image such as research ability remains yet as a very import image. (2) Except (A, F) & (B, E) university, common position is not found among the 7 universities, therefore each university cultivate important image as G university dose. (3) Private university are underestimated by student of national university. There is a necessity for cultivating and promoting private university images. (4) Students of private university, particularly students of F university, overestimated their university images seriously.