• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1553-1555
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• 2005

This paper presents a design of lossless hybrid-type magnetically-levitated vehicle. The lossless hybrid-type system is implemented by a permanent magnet and electromagnet. The target plant consists of eight hybrid-type magnets and in the steady-state, no current is needed to support the load. The design procedure is described and the results of this work are shown.

• Nonlinear Functional Analysis and Applications
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• v.29 no.1
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• pp.113-130
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• 2024

In this work, we explore the existence and uniqueness results for a class of boundary value issues for implicit Volterra-Fredholm nonlinear integro-differential equations (IDEs) with Atangana-Baleanu-Riemann fractional (ABR-fractional) that have non-instantaneous multi-point fractional boundary conditions. The findings are supported by Krasnoselskii's fixed point theorem, Gronwall-Bellman inequality, and the Banach contraction principle. Finally, a demonstrative example is provided to support our key findings.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.643-651
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• 1996

In this paper, to provide the possibility of various multimedia services, especially the collaborative work using the centralized control feature of the Service Node, is studied. We focused on the telewriting as the upper layer application to confirm the basic functions of the collaborative work. For this, we implement and add telewriting collaborative work function to the Service Node emulator, and terminals operating in the Windows environment are also developed. Through the tests on the system, we verify the basic functions related to the collaborative work are performed adequately, and confirm the concept of Service Node can support various type of multimedia conference services.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.146-153
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• 2012

RP system which is widely used to reduce the time of product development is to resolve the problem of cutting work. It is a method using laminated thin films to produce many forms. The RP equipment used for this experiment is FDM system. This can produce 3D model with using 3D CAD designed file within a relatively short time. Not only this, this system also through 3D file preparation, 3D product manufacture, removal support these 3 step operating process can easily produce goods, but product can be different from original design. This research has been conducted to minimize this error. To apply to the circular product made a circular specimen and measured several times with 3D scanner and find out average 99.622% of accuracy. This result is applied to RP system, and with this changed design produced a specimen, and found out the accuracy is increased to 99.958%. If this is applied to circular products, we can produce more precise products with less process.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.170-174
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• 1990

The information with regard to the working range of lathe, cutting tool, cutting condition is managed as Database system for turning operation as one part of CAM system. Data with regard to the working range of lathe, cutting tool, cutting condition are stored by the DBMS(Data Base Management System) and can be added, modified, deleted and retrieved for realtime usages. Data stored in Database system are searched to select the most proper cutting tool and cutting condition with the input data fed from the design stage. Codes in regards to tool shape are displayed on graphic mode for easy selection for user and thus presents a good decision support for tool selection. The system developed in this work is operated by the pull down menu on the IBM PC/AT personal computer, or compatible series.

• The Transactions of the Korea Information Processing Society
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• v.6 no.10
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• pp.2752-2763
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• 1999

On account of the text based mail system has it's limit to support multimedia applications, GUI based mail system platform was developed to control document flow and automatize information process. The existing mail systems's to transmit data must need additional functions to automate document flow control. The platform of document flow control is deeply related to EDMAS(Electronic document Management System), workflow, Electronic Banking, DMS(Document Management System) automation, so it needs an ability to control proper data and document correctly. To resolve this problems, we are need of browser and engine to design work flow and to control documents flow. In this paper, we develope a mail browser to design document flow by follow user's requirements. This system can generate executive script code for document flow, and we add the function of workflow and process management to automatize the document flow in this system, and then we implement this Data flow engine.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.186-187
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• 2021

Education in Korean universities is rapidly expanding to online education due to COVID-19. In response to such changes, this study proposed a means of improving the learning management system of Korean universities and analyzed the effects of using the system. The important results of this study are as follows: the learning management system was composed of 'pre-class learning,' 'team activity,' and 'participation learning' to support team-based learning. The effects that the users (instructors, learners) can obtain by adopting team-based learning and using the system were analyzed. The study concludes that for instructors, teaching work may be alleviated. For learners, it was demonstrated that they could more easily access and use data required for their education.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1304-1317
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• 2020

The tubes in a heat exchanger, such as a steam generator (SG), are subjected to crossflow, and interaction between tubes and supports can happen, which can cause fretting wear of tubes. Although many experiments and models have been established, some detailed mechanisms are still not sufficiently clear. In this work, more attention is paid to obtain the regulation of impact and sliding in the complex process and many factors, such as excitation forces and clearances. The responses and contact forces were analyzed to obtain clear understanding of the influences of these factors. Room temperature tests in the air were established. The results show that the effect of clearance on the normal work rate is not monotonous and instead has two peaks. The force ratio can influence the normal work rate by changing the distribution of contact angles, which can result in higher sliding in the contact process. Fretting wear tests are conducted, and the wear surfaces are analyzed by a scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDX). The results of this work can serve as a reference for impactsliding contact analysis between AVBs and tubes in steam generators.

• Korean Journal of Construction Engineering and Management
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• v.21 no.1
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• pp.61-69
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• 2020

As the amount of information generated in the construction project increases exponentially, design and construction review have a serious impact on the success of the site. For this reason, academic and business circles have been expanding the use of BIM at the whole life, and BIM is now accepted as one of the standards used in the construction industry. However, the BIM-based design for the temporary work is used as an aid to the 2D design because there is no specialized software and there is absolutely lack of a professional engineer. The objective of this research is to develop BIM-based temporary work support system. This system minimizes human errors in BIM-based design, quantity takeoff and inspection and shortens working hours.

• Journal of the Ergonomics Society of Korea
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• v.32 no.1
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• pp.145-152
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• 2013

Objective: The aim of this study is to develop an ergonomic office chair that has an alarm function for the unbalanced sitting postures. Background: Contrary to expectation, it is reported that office workers sit on their chairs much more in unbalanced postures during daily work. Even though an office worker uses an ergonomically good-designed chair and begins their work in a good sitting posture, his/her posture is likely to shift to the unbalanced bad posture. Therefore, a posture alarm system would be very helpful in keeping office workers' good postures. Method: We developed a prototype chair with four load cells under a seat pan and one load cell beneath a backrest. Through some experiments, we set the criteria for unbalanced bad postures then implemented the criteria into the alarm system of the prototype chair. The chair called e-BASE chair could detect unbalance postures and show alarms for chair users. We also enhanced back support by developing a step-wised folding backrest. Results: The e-BASE chair showed better performance in interface pressure distributions and balanced posture ratio in VDT work. Conclusion: The ergonomic chair with posture alarm function(e-BASE chair) was developed. It showed better performance in seat pressure distribution and in keeping good posture during office work. Application: The posture alarm system and folding backrest can be applied to the new models of office chair.