• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.96-111
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• 1995

A bellows is a component installed in the automobile exhaust system to reduce the impact from an engine. It's stiffness has a great influence on the natural frequency of the system. Therefore, it must be designed to keep the specified stiffness that requires in the system. This study present the finite element analysis of U-typed bellows using a curved conical frustum element and the shape optimal design with specified stiffness. The finite element analysis is verified by comparing with the experimental results. In the shape optimal design, the weight is considered as the cost function. The specified stiffness from the system design is transformed to equality constraints. The formulation has inequality constraints imposed on the fatigue limit, the natural frequencies, the buckling load and the manufacturing conditions. A procedure for shape optimization adopts a thickness, a corrugation radius, and a length of annular plate as optimal design variables. The external loading conditions include the axial and lateral loads with a boundary condition fixed at an end of the bellows. The recursive quadratic programming algorithm is selected to solve the problem. The result are compared with the existing bellows, and the characteristics of the bellows is investigated through the optimal design process. The optimized shape of the bellows are expected to give quite a good guideline to the practical design.

• Nuclear Engineering and Technology
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• v.46 no.5
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• pp.595-604
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• 2014

SILER (Seismic-Initiated event risk mitigation in LEad-cooled Reactors) is a Collaborative Project, partially funded by the European Commission in the $7^{th}$ Framework Programme, aimed at studying the risk associated to seismic-initiated events in Generation IV Heavy Liquid Metal reactors, and developing adequate protection measures. The project started in October 2011, and will run for a duration of three years. The attention of SILER is focused on the evaluation of the effects of earthquakes, with particular regards to beyond-design seismic events, and to the identification of mitigation strategies, acting both on structures and components design. Special efforts are devoted to the development of seismic isolation devices and related interface components. Two reference designs, at the state of development available at the beginning of the project and coming from the $6^{th}$ Framework Programme, have been considered: ELSY (European Lead Fast Reactor) for the Lead Fast Reactors (LFR), and MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) for the Accelerator-Driven Systems (ADS). This paper describes the main activities and results obtained so far, paying particular attention to the development of seismic isolators, and the interface components which must be installed between the isolated reactor building and the non-isolated parts of the plant, such as the pipe expansion joints and the joint-cover of the seismic gap.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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• pp.422-430
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• 1998

This paper presents the results of a major parametric study on the collapse cause of the Sungsoo Grand Bridge, a Gerber-type continuous truss bridge, which had collapsed just at the 15th year since opening to traffic. Among the various collapse causes such as poor design, poor welding, poor maintenance, and heavy traffic loads, this study focuses on the collapse cause assessment incorporating the effects of braket and H-beam members right below the expansion joint of the suspended truss. A local FEM analysis using fine shell elements is carrided out for the more precise estimation of stress range of the vertical pin-connected hanger whose fatigue fracture triggered the collapse of the bridge. Both the conventional S-N approach and the Ang-Munse's fatigue reliability method are used for the evaluation of the fatigue life and fatigue failure probability for the assessment based on all the available results of various field and labolatory tests. From these observations, It may be affirmatively stated that the effects of bracket and H-beam members accelerated the fatigue failure, and thus should be regarded as one of major causes that triggered the bridge collapse

• The Journal of Fisheries Business Administration
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• v.30 no.1
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• pp.149-158
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• 1999

The Fisheries Business Administration Society of Korea(FBASK), with Dr. Jeong-yoon Choe as its president, and the The Japan Regional fisheries Society of Japan(JRFS), currently headed by Dr. To-ru Kurada, jointly held a symposium on 25 June, this year(1999) at international conference hall of Lotte Hotel, Pusan, Republic of Korea. The symposium, with its theme being as “the fisheries's vision in 21th century”, attracted 150 participants, including scholars specialized in the field of fisheries social science from both sides, officials from both sides, officials from the Ministry of Marine and Fisheries of Korea, and representatives of Korea fishing industry. Among those, 11 scholars, with membership of FBASK or JRFS, presented their papers or took part in discussion at this symposium. It was anticipanted that this symposium would provided new opportunities for the expansion of academic exchange between Korean and Japanese fisheries experts. This paper reviews the background, the operation, performance, and outcomes of the symposium and the paper is structured as follows ; 1. the background under which this symposium was held ; 2. the selection of the symposium's theme ; 3. the presentation and discussion at the meeting ; and 4. the preformance and outcomes of symposium

• Journal of radiological science and technology
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• v.11 no.2
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• pp.21-26
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• 1988

Newly developed orthochromatic film HR series have many different types according to high speed, high resolution and special latitude. And now authors have practiced various screen-film combinations, those were usual regular type Fuji new RX film-LT screen and orthochromatic type HR films-rare earth G3, G4 screens. As a result of the experiment, we obtained high speed with high resolution and expansion of diagnostic range on the following combinations compared with usual new RX/LT series. Those combinations were RXO-G and HR-L films to skull, HR-G films to knee joint and hand part, HR-L film to abdomen. Therefore it may be desirable to select adquate kinds of HR series films according to investigated parts.

• Journal of the Korean Society for Library and Information Science
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• v.53 no.4
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• pp.399-418
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• 2019

In accordance with the recent expansion of collection operation of independent publications through public libraries, this study conducted a status analysis on independent publications collection in public libraries and in-depth interviews with staff in charge of independent publications in order to suggest ways to effectively manage independent publications. As a result, it was deduced that the measures needed for effective management of independent publications are construction of joint cataloging system for building and sharing independent publications catalog in public libraries; platform for collecting various information of independent publications; support for ISBN, ISSN, CIP issuance of independent publications; and improvement of distribution system.

• Journal of Korea Multimedia Society
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• v.22 no.10
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• pp.1142-1148
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• 2019

Reconstruction of the three-dimensional (3D) environment is a key aspect of augmented reality and augmented virtuality, which utilize and incorporate a user's surroundings. Such reconstruction can be easily realized by employing a Kinect device. However, multiple Kinect devices are required for enhancing the reconstruction density and for spatial expansion. While employing multiple Kinect devices, they must be calibrated with respect to each other in advance, and a marker is often used for this purpose. However, a marker needs to be placed at each calibration, and the result of marker detection significantly affects the calibration accuracy. Therefore, a user-friendly, efficient, accurate, and marker-less method for calibrating multiple Kinect devices is proposed in this study. The proposed method includes a joint tracking algorithm for approximate calibration, and the obtained result is further refined by applying the iterative closest point algorithm. Experimental results indicate that the proposed method is a convenient alternative to conventional marker-based methods for calibrating multiple Kinect devices. Hence, the proposed method can be incorporated in various applications of augmented reality and augmented virtuality that require 3D environment reconstruction by employing multiple Kinect devices.

• Journal of Forest and Environmental Science
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• v.37 no.1
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• pp.69-78
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• 2021

This study aims to verify a difference between the years 2014 and 2019 of Uiryeong-Gil, which is operated by the Visitor-Reservation System, in terms of the cognition of system, operational effectiveness, and behavioral intention. The analysis is as follows. First, among the overall cognition of the Visitor-Reservation System, the satisfaction from - prevention for safety for accident, expansion to other parks, number of visitor restriction, and satisfaction with reservation method - increased compared to 2014. Second, among the effects of the Visitor-Reservation System operation, satisfaction shows differences in year-to-year levels in terms of resource protection, resource damage mitigation efficiency, natural experience opportunity, comfort of visit-environment, and prevention of illegal activities. Third, the analysis of the differences in the behavior of the Visitor-Reservation System showed that the satisfaction of visitors, revisit intention, and overall satisfaction differed per year. The results of this study are meaningful in that the Visitor-Reservation System is no longer the restriction, but the change in cognition for the protection of ecosystems and sustainable visiting in order to expand the Visitor-Reservation System into a sustainable policy.

• Journal of the Korean Institute of Gas
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• v.24 no.6
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• pp.83-90
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• 2020

This study conducted a risk assessment using the HyKoRAM program created by international joint research. Risk assessment was conducted based on accident scenarios and worst-case scenarios that could occur in the facility, reflecting design specifications of major facilities and components such as compressors, storage tanks, and hydrogen pipes in the hydrogen charging station, and environmental conditions around the demonstration complex. By identifying potential risks of hydrogen charging stations, we are going to derive the worst leakage, fire, explosion, and accident scenarios that can occur in hydrogen storage tanks, treatment facilities, storage facilities, and analyze the possibility of accidents and the effects of damage on human bodies and surrounding facilities to review safety.

• East Asian Journal of Business Economics (EAJBE)
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• v.10 no.3
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• pp.51-61
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• 2022

Purpose - The purpose of this study is to establish the government's logistics policy by calculating the logistics cost of the company and grasping the management status, to reduce the logistics cost of the related companies and to provide basic statistical data necessary for the management strategy. This work examines some associations between reasons for reducing corporate logistics costs (RCLC) and corporate classification such as industry and sales size. Research design, data, and methodology - The survey was conducted in 2018 for 2,000 companies based on the business of mining, manufacturing and wholesale and retail industries since 2010. The survey population is 94,976, of which 92,708 are small and medium enterprises and 2,268 are large corporations. The association among factors may be statistically and visually explored by using chi-squared test and correspondence analysis. Result - This study reveals the association between reasons for RCLC and corporate classification and properties and closeness that exist between the categories of each factor can be mined. Conclusion - As a task to reduce logistics costs of industrial products, expansion and operation of joint logistics business, establishment of cooperative logistics network, and establishment of ordinance on support for smart distribution logistics can be proposed.