• Journal of Power System Engineering
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• v.5 no.1
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• pp.80-88
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• 2001

The spot welding method has been used in the joining of structures, automotive body, railway carriage, aircraft, household electric appliances, precision parts etc., because of brief working, easy automation, available mass production, and convenience. In this paper, the effects of welding conditions on the fatigue life and the prediction of fatigue life based on fracture mechanics theory of spot welded joint were investigated. Fatigue tests were conducted with the tensile-shear specimens welded in the various current using cold rolled steel sheets. Fatigue life of spot welded joint was predicted and compared with experimental results. Using FEM(finite element method), we analysed the distribution of stress and the condition of deformation on the environments of nugget.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.772-778
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• 2011

ISO6954:2000 (Mechanical vibration - Guidelines for the measurement, reporting and evaluation of vibration with regard to habitability on passenger and merchant ships) has taken effect as the governing body for vibration regarding habitability due to ship vibration. However, ISO6954:2000, when compared ISO6954:1984 (the first draft of ISO6954), needs to clear some deficiencies concerning convenience and reliability during field applications. In this paper, ISO6954:1984 and 2000 are evaluated on their suggested assessment method of ship's vibration in the future.

• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.5
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• pp.227-236
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• 2017

This study reviews concepts, theories and formulas included in standards on soil-structure interaction and also shows practical example of application for engineers. Real structures are 3 dimensional and multi degree of freedom but they are often idealized to single degree of freedom for convenience. In this study, detailed procedures to calculate soil spring constants and damping coefficients and method to model soil-structure system are explained. Additionally, case studies to judge fixed base condition and evaluation of applicability of simple analysis method based on response spectra are performed.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1060-1062
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• 2003

In this study, an insulation design program which can calculate electric field of the GIS bus parts easily was developed. It also can evaluate the insulation safety depending on gas density. For bus parts of $1{\varphi}$ GIS, it was intended to provide a optimal diameter of a conductor and an enclosure automatically for the convenience of GIS insulation designer. This program was coded by Visual Basic and electric field was calculated by the Charge Simulation Method(CSM), which is one of the most accurate method for an electric field analysis.

• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.145-151
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• 2008

The purpose of this study was to understand users' attitudes for trail structure conditions in Dobong district, Bukhansan National Park, Korea. For this purpose, the research conducted a respondent's-personal entry-method based questionnaire survey on 250 visitors using inquiry routes in Dobong areas in Bukhansan National Park in July, 2007. The survey result showed that the 6 types of pedestrian trail structures were relatively in better shape in its quality and quantity while the responses for 3 types of structures, such as wood deck, wood railings, and stone paving, were positive in terms of harmony with landscape, preservation of resources, and user convenience. In conclusion, it is considered to be essential to bring in nature-friendly materials for walking facilities in National Parks and also necessary to consider the visual effect arising from the harmony with landscape together with the functions of conservation of resources and inquiry convenience.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.5
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• pp.13-29
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• 2022

According to the revision of the Convenience Act for Persons with Disabilities, parks and park facilities where the first park development plan is established after December 4, 2021 are mandatory, and parks must be equipped with convenience facilities for the disabled. Hence, this study aims to derive the improvements of the park evaluation index by analyzing the park certification evaluation index, the building certification evaluation index of park facilities, and the evaluation reports of the current certification status cases. As a research method, first, the certification of parks and park facilities were compared and reviewed with the Park Green Act, and differences in the certification process and certification performance were compared and analyzed. Second, differences and common items were derived by analyzing barrier free (BF)-certification evaluation indicators for parks and buildings. Third, improvement plans were derived after analyzing differences and problems in 4 BF-certified parks and four building certification cases of park facilities in certified parks, focusing on the self-evaluation report and examination results. As a result of analyzing the park and building evaluation indicators, the items for which the evaluation purpose, evaluation method, and evaluation items were commonly applied to 7 access roads for each facility, 5 parking areas for the disabled, 2 guide facilities for information facilities, 14 in 5 categories of sanitation facilities, and 1 for other facilities. In the case of sanitation facilities, there is no case where it was evaluated as a park. If the park does not have an attached toilet, the park is certified as a building. Hence, it would be essential to establish the concept of an attached toilet and discuss the application of the evaluation index on the park sanitation facility. The score of buildings in parks and park facilities was lower than that of the self-evaluation results, and the certification grades of buildings declined in three cases. The items with the highest standard deviation were BF walking continuity for parks and the path to the main entrance among access roads for buildings. As a result of analyzing the park and building evaluation results of 19 common evaluation items except for sanitary facilities, the difference in the grades of the evaluation items for each case site except for one item appeared. Therefore, applying common detailed calculation criteria for items evaluated in common with parks and buildings is needed. Since sanitation facilities have no cases of park certification and are not certified as buildings, it is essential to establish the concept of attached toilets and discuss the application of park sanitation evaluation indicators. It is necessary to develop an evaluation index suitable for the characteristics of the park, such as adjusting the items that are not evaluated in parks and establishing an evaluation index considering the ones of parks. It expects that this study would be used as primary data for improving park certification indicators.

• Tunnel and Underground Space
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• v.25 no.3
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• pp.264-274
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• 2015

In this study, the applicability of geotextile mesh soil nails on slopes was evaluated by numerical analysis to reduce environmental problems which a general soil nailing might produce and to improve its economical efficiency and construction convenience. To this end, in situ pull-out tests were conducted for both general soil nail and geotextile mesh soil nail and their pull-out characteristics were analyzed. Also, finite difference method was used to verify the suitability of numerical simulation. Parameters for nail and ground conditions were selected and sensitivity analysis was performed for the evaluation of slope stability. In addition, analysis was performed by limit equilibrium method which is widely used for slope stability analysis in practice. As a result, if the nail diameter was same, there is no big difference between geotextile mesh soil nails and general soil nails in terms of slope stability. Therefore it can be expected that geotextile mesh soil nails could be effective for slope reinforcement since they could keep a slope as stable as general soil nails and give better economical efficiency and construction convenience than general soil nails.

• Korean Management Science Review
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• v.18 no.1
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• pp.55-68
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• 2001

A virtual shopping mall is like a real-world mall, supports electronic shopping by selling products or services through Interne. Although increasing numbers of products are being marketed on the Web, little efforts has been spent on evaluating what mall is more suitable for marketing electronically and for protecting consumers. Evaluation of virtual shopping malls is regarded as a major task in business-to-consumer electronic commerce. This paper considers the Analytic Hierarchy Process(AHP) method in the evaluation of virtual shopping malls and provides its applications. The AHP is a systematic procedure for representing the elements of any problem, hierarchically. A series of pairwise comparison judgments is performed to express the relative strength or intensity of impact of the elements in the hierarchy. The AHP model hierarchy consists of the four following levels: decision maker, main criteria, sub-criteria, and virtual shopping malls. the main criteria include the state of physical firms, representation of information on the virtual shopping malls, product or service, convenience for shopping, consumer protection, and consumer service. The total number of sub-criteria in the third level is twenty-nine. All decision makers selected belong to virtual shopping mall enterprises, or universities. As a case study, we show the synthesized priority of the five virtual shopping malls that have acquired an E-Trust mark. Finally a sensitivity analysis shows how well each virtual shopping mall performs on each criterion by increasing or decreasing the importance of the main criteria.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1B
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• pp.25-37
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• 2008

Network streaming technology is a service method which can support several application software via streaming in networks. Although multimedia streaming technology has been developed and widely used, research on the software streaming technology is not yet being progressed actively. In this paper, we design and implement a software streaming technology based on Java language with enhanced performance, compare the existing related systems with it and analyze several characteristics, and perform the performance evaluation. The implemented system has a platform to be used in multiple operating systems in addition to Windows system. It can also be used without installing a software at the client's computer, and has a novel feature that the user's convenience is maximized.

• Journal of Information Processing Systems
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• v.20 no.1
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• pp.105-115
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• 2024

The hybrid teaching approach of "MOOC + SPOC + Flipped Classroom" overcomes the constraints of time and space that are typically associated with traditional teaching methods, thus compensating for the shortcomings of traditional approaches. These changes in education are driven by the "Internet+" wave and the growing popularity of online teaching. The "MOOC + SPOC + Flipped Classroom" hybrid teaching mode can successfully compensate for the drawbacks of traditional teaching methods, thereby overcoming their restrictions. By defining relevant concepts, one can distill the key characteristics of the "MOOC + SPOC + Flipped Classroom" hybrid teaching mode. Formative assessment was employed to thoroughly evaluate the effectiveness of this teaching approach. By leveraging the advantages of massive open online course (MOOC), small private online course (SPOC), and flipped classroom, the "MOOC +SPOC + Flipped Classroom" teaching mode incorporates real-time student assessment through peer evaluation, computer-aided evaluation, and teacher evaluation. This mode promotes the simultaneous development of theoretical knowledge and practical skills, helping students to establish strong foundations while fostering their practical abilities. While the traditional teaching method remains fruitful, the convenience of today's network allows the teaching profession to continually evolve. The traditional teaching mode heavily relies on teachers, making it impossible to conduct lessons without them. However, the development of MOOC enables students to seek knowledge online from their preferred teachers, rather than solely relying on their assigned instructors.