• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.1
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• pp.284-294
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• 1996

In this paper, dynamic characteristics of an AT clutch system were investigated considering the dynamics of check ball and hydraulic control valves. Dynamic model of a pressure control solenoid valve (PCSV) was obtained by Bondgraph and permeance method. Also, the clutch piston and check ball dynamics were modeled by considering the effect of centrifugal force of the oil entrapped in the clutch chamber. In order to validate the dynamic models obtained, plunger displacement of PCSV and pressure response of the clutch supply lines were compared with the available experimental data, which were in good accordance with the numerical results. Using the dynamic model of the clutch system, simulations were performed to investigate the effect of the rotational speed on the response of clutch cylinder pressure, clutch piston and check ball displacement, and oil flow rate into the cylinder and flow rate out of the check valve.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.798-803
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• 1988

This paper is concerned with a computer-aided supporting system to a systematic check of mechanical drawings. The problems treated in this paper are limited to the checking of the omissions and mis-writings of dimensioning in the mechanical drawings made by a CAD system. A drawing check system has been made up on a personal computer with Basic and Pascal. The feasibility of the proposed drawing check system is confirmed for omissions and mis-writings of dimensioning in mechanical drawings.

• Journal of Service Research and Studies
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• v.9 no.2
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• pp.31-40
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• 2019

In this paper, we have studied the improvement of operational control for the enhancement of business continuity of information system becoming more important with the development of information technology such as big data, Iot, and artificial intelligence. The operational management and audit guidance of the current information system, which is coming in the fourth industrial age, where various services, data and industries are converged, is based on the existing general information system pattern and needs to be improved. The provision of services at fixed times is linked to the survival of enterprises and countries and serves as a key element. Therefore, it is necessary to study the application of optimized check items of the operation audits to minimize the service interruption damage of the information system and to provide the stable service in terms of business continuity management. To accomplish this, the check items presented in the operational control of the information system were derived by combining the PDCA step contents and 8 resource requirements provided in ISO 22301. From the point of view of increasing the business continuity according to the derivation criteria of the inspection items, the operational inspection check items were derived by exemplifying the improved check items and review items of the information system operation audit and the products to be checked during the operational audit. The check items were divided into management audit improvement check items for service continuity management, and operational audit improvement check items for performance and availability management. The average score of the IT professionals' survey on the suitability of the proposed checklist was 4.63, which was concluded to be appropriate.

• Journal of the Korea Safety Management & Science
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• v.8 no.4
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• pp.119-127
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• 2006

This paper deals with the middleware and S/W development of real time automatic attendance check management system using ubiquitous 900Mhz RFID(Radio Frequency Identification). This system supports the real time automatic attendance check and necessary data processing in class management. We expect to decrease the effort for class management and to upgrade the status of real time management of class.

• Journal of Aerospace System Engineering
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• v.12 no.5
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• pp.54-68
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• 2018

The objective of this study is to analyze the effect of dynamic characteristics of the check valve applied to the small piezoelectric-hydraulic pumps on flow rate formation. The flow rate of the piezoelectric-hydraulic pump is a key factor in the formation of the load pressure to operate the brake system. At this time, the natural frequency of the check valve operating in the fluid has a great influence on the formulation of the flow rate of the piezoelectric-hydraulic pump. In addition, the natural frequency of the check valve is affected by the gap between the check valve and the pump seat. In this study, the natural frequency of the check valve according to the gap between the check valve and the pump seat was calculated through the fluid-structure interaction analysis. The flow rate obtained from the simulation result was verified by comparing it with the result from the flow rate experiment using the developed piezoelectric-hydraulic pump.

• Journal of Information Management
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• v.20 no.1
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• pp.117-138
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• 1989

In this article, the organizational structures of check- in and claim function are examined. The procedure and function of serials control system(CLASSMATE, EBSCONET, LINX, NOTIS, INNOVACQ) are analyzed, particularly in check- in and claim system. A check-in and claim system is suggested through analysis of above serials control systems.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.1
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• pp.3-10
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• 2003

In this paper, a partially blind signature schemes baled on EC-KCDSA is proposed and we applied it to design an electronic check payment system. Because the proposed partially blind signature scheme uses elliptic curve cryptosystem, it has better performance than any existing schems using RSA cryptosystem. When issuing a refund check, one-time pad secret key is used between the bank and the customer to set up secure channel. So the symmetric key management is not required.

• Journal of the Korea Society of Computer and Information
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• v.18 no.3
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• pp.59-68
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• 2013

In this study, airport security check process is analyzed to modeling a simulation. Simulation is compared with real security system to verify. Utilizing verified simulation, spends time in the current security check is calculated and suggests alternatives. Considering the movement of passengers and security check system of all four cases the results yielded by the experiment. The results show that security check time decreased significantly to 20.8%. The simulation was developed in this study; including the introduction of a new security system at security check can be used as a decision support tool is expected.

• Journal of The Korean Association of Information Education
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• v.18 no.2
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• pp.325-334
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• 2014

There are management and price problems that have been caused by requirement of RFID reader, Fingerprint Identification System and Clicker for the construct of automatic attendance system to check the students' attendance accurately and quickly. Therefore, in the thesis, we developed smartphone based attendance check system by utilizing Wi-Fi and the smartphones that has been already built without using additional equipments and establishing construction of system additionally. It recognizes date, time, location and the seat number in classroom if a student logs the attendance chocking application in and it also allows students to get lecture feedback and check attendance by taking quizzes and questionnaires that are related to the lecture. As a result, by applying the attendance check system, instructors state that it is convenient since the app allows instructors to communicate with students though the quizzes and questionnaires. Especially, the instructors state that it is convenient because the results of the quizzes, questionnaires and attendance can be downloaded it the from of Excel files.

• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.210-217
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• 2021

In the case of an agile-based project, it was inadequate to perform a comprehensive inspection and evaluation on the establishment and operation of an information system by performing audit only with the audit and inspection elements provided by the existing information system audit and inspection system. In particular, in the case of the test activity area, it was necessary to improve the test activity audit check items to comprehensively check the agile-based development process by applying the existing audit system. To this end, a test activity improvement check model of the agile methodology audit model was presented by applying the repetition concept, a characteristic of the agile methodology. In order to empirically verify the model of this study, a survey was conducted for auditors and designers/developers who have experience in performing agile-based projects and auditing information systems. As a result of the questionnaire on the integrated test and system test in the test stage, more than 70% of the respondents were found to be suitable. More than 80% of the respondents judged that it was appropriate as a result of the questionnaire on "improvement and regression test progress according to integrated test and system test results" and "integrated test and functional actions of components and subsystems".