• Journal of the Korean Society of Systems Engineering
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• v.8 no.2
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• pp.27-36
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• 2012

In modern systems, the operational capability of the system to the user needs is expanding rapidly to accommodate the size of the system, functionality, and interfaces are becoming increasingly complex. Accordingly, the systematic practice of project management and systems engineering in the system development process, as an important element in successful systems development is recognized. EIA/ANSI 632, ISO/IEC15288, the leading international standard for systems engineering and is the leading international standard on project management PMBOK. CMMI is also contains information about the activities of project management and systems engineering and worldwide basis to assess the maturity of an organization's ability to develop system being used. But CMMI model is too complex of structure and there are many overlap parts of contents. So there are many problems for members of organization understanding all of CMMI model, applying organization and, achieving improvement activity. In this study, through the analysis and integration between the model and the related standard coverage activities essential for successful systems development in organizations that require systems engineering and project management capabilities(SEPMC) for self-assessment and continuous improvement activities to provide useful reference guideline.

• International Journal of Railway
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• v.9 no.2
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• pp.36-40
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• 2016

TETRA communication system is very versatile system which can transmit voice + data and packet data optimized. Direct mode operation permits to connect between mobiles when mobile stain is out of coverage of networks. It can be more secure communication channel for railway signaling systems. Railway signaling systems use many of wayside signal equipment, which require many maintenance efforts and budget. Many railway authorities want to reduce and replace the wayside equipment. Radio based signaling systems are one of candidate for replacing the conventional signaling systems. The radio based signaling systems can replace track circuit and wayside signal. The radio systems permit to connect between control centers and trains. The radio systems have to ensure high quality of the connectivity more or equal to the existed track circuits. We studied the application of TETRA systems for railway radio systems for bridging between train control centers and trains. We provide an operation scenario for radio based train control system to ensure the safety require to the existed trains control system and satisfied the existed operational availability. We showed the data transmission speed, maximum bit error rate, and data coding for the radio-based signal system using TETRA systems.

• Smart Structures and Systems
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• v.15 no.6
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• pp.1521-1542
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• 2015

The use of shape memory alloys (SMAs) in dynamical systems has an increasing importance in engineering especially due to their capacity to provide vibration reductions. In this regard, experimental tests are essential in order to show all potentialities of this kind of systems. In this work, SMA springs are incorporated in a dynamical system that consists of a one degree of freedom oscillator connected to a linear spring and a mass, which is also connected to the SMA spring. Two types of springs are investigated defining two distinct systems: a pseudoelastic and a shape memory system. The characterisation of the springs is evaluated by considering differential calorimetry scanning tests and also force-displacement tests at different temperatures. Free and forced vibration experiments are made in order to investigate the dynamical behaviour of the systems. For both systems, it is observed the capability of changing the equilibrium position due to phase transformations leading to hysteretic behaviour, or due to temperature changes which also induce phase transformations and therefore, change in stiffness. Both situations are investigated by promoting temperature changes and also pre-tension of the springs. This article shows several experimental tests that allow one to obtain a general comprehension of the dynamical behaviour of SMA systems. Results show the general thermo-mechanical behaviour of SMA dynamical systems and the obtained conclusions can be applied in distinct situations as in rotor-bearing systems.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.9
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• pp.1096-1102
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• 1999

This paper discusses the evaluation of interconnection capacity of small cogeneration(SCOGN) systems to the power distribution systems from the viewpoint of voltage regulation. Power utilities are required to keep the customers' voltage profile over a feeder close to the rated value under all load conditions. However, it is expected that the interconnection of SCOGNs to the power distribution systems impacts on the existing voltage regulation method and customers' voltage variations. Therefore, SCOGNs should be integrated to the automated power distribution systems to prevent interconnection problems and supply high quality electricity to the customers. For these reasons, we should proceed with the evaluation of interconnection capacity of SCOGNs to the power distribution systems. However, it is generally impossible to perform actual testing on the power distribution systems, and standardized methodologies and guidelines are not developed to evaluate it. The criterion indexes for voltage regulation and variations are presented in order to evaluate the interconnection capacity of SCOGNs to the power distribution systems. In addition, the evaluation methodology of interconnection capacity of SCOGNs for power distribution systems is presented. It is expected that the resulted of this paper are useful for power system planners to determine the interconnection capacity of SCOGNs and dispersed storage and generation (DSG) systems to the power distribution systems.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.6
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• pp.477-486
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• 2001

Many physical systems can be modeled by incorporating continuous and discrete event nature together. Such hybrid systems contain both continuous and discrete states that influence the dynamic be-havior of the systems. There has been an increasing interest in thers types of systems during the last dec-ade, mostly due to the growing usage of computers in the control of physical plants but also as a result of the hybrid nature of physical processes. The stability theory for hybrid systems is considered as extension of Lyapunov theory where the existence of an abstract energy function satisfying certain properties verifies stability, called multiple Lyapunov theory. In this paper, a hybrid stabilizing controller is proposed using the control Lyapunov function method and multiple Lyapunov theory, and the proposed method is applied to lon-gitudinal spacing control in a vehicle platoon for intelligent transportation systems(ITS).

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.4
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• pp.373-380
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• 1997

In order to implement the real-time operating systems for robot controller, this paper proposes a systematic method for implementing the real-time kernel under the DOS environment. So far, we designed the robot control software and its own operating system simultaneously. Though robot operating systems have simple structure, it allows the developer to have a surplus time and effort to implement complete robot systems. In addition to this, in most cases of this type, operating systems does not support multitasking function, thus, low level hardware interrupts are used for real-time execution. Subsequently, some kinds of real-time tasks are hard to implement under this environment. Nowadays, the operating systems for robot controller requires multitasking functions, intertask communication and task synchronization mechanism, and rigorous real-time responsiveness. Thus, we propose an effective and low costs real-time systems for robot controller satisfying the various real-time characteristics. The proposed real-time systems are verified through real implementation.

• Asia pacific journal of information systems
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• v.15 no.1
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• pp.81-113
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• 2005

IT has affected the hospital management via information systems and multimedia systems such as hospital information systems(HIS) and Order Communication System(OCS). A large number of researches have been done on the topic of success factors of information systems implementation, but a few on the topics of hospital information systems. Thus in this study, the success factors of the military hospital information systems implementation was analysed. To this end, a number of previous researches were reviewed and about 71 items of success factors were deduced. For doing empirical analysis, a questionnaire with 71 items was prepared and sent to proper organizations. The statistical analysis such as factor analysis was applied to about 400 of them returned. The six success factors and 20 sub success factors were resulted from factor analysis. The six success factors include systems management factor, technology and organization factor, the efficiency of IT department factor, technology application factor, outsourcing factor and environment factors. This study finds the outsourcing and environment factors are very important factors as much as other success factors which previously were mentioned.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.2
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• pp.242-263
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• 1995

The study was to find out the current situation of supply and demand of apparel CAD systems in Korea. Also it was hoped to gather any valuable information about the current usage of apparel CAD systems for the development of the enhanced apparel CAD system. Three interviews were carried out for the study. The first interview with the importing agents was to find out the apparel CAD system's supplying situation. The second interview with the users of apparel CAD system was about the usage of the systems and related informations. The last interview was about the pattern making facilities, which was pointed out by the users to be the most inconvenient part of apparel CAD systems. The results of the survey were: 1. The supply and demand of apparel CAD systems is increasing. 2. The education, training, maintenance of the system should be improved by the supplier. 3. Apparel CAD systems are used for various production systems in the apparel industry. 4. 100% of the systems are utilized for pattern input and 89% of the systems are utilized for marker making. Only 15% of the systems are utilized in pattern making process, which 80% of the users realize to be computerized. 5. The most serious barrier to the better usage of the system is the communication with the system in foreign language. This barrier could be lifted when Korean apparel CAD system is developed.

• Management & Information Systems Review
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• v.19
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• pp.105-128
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• 2006

In accomplishing the objectives of the hospital organizations effectively the good results of hospital information systems depends upon the usefulness and forms of informations provided by them under certain conditions. This study is aimed at examining how much hospital information systems are influenced by the characteristics of organizations and information systems. The results are as follows. 1. In the viewpoint of variations of organization characteristics, the support of chief executive group, the participation of users, education and training has good effects on satisfaction rates of users and system utilization rates as evaluation instruments of results of hospital information systems. 2. In the viewpoint of information system characteristics, the nearness of information sources, the scopes and qualities of informations has good effects on satisfaction rates of users and system utilization rates as evaluation instruments of results of hospital information systems. Accordingly interests and supports of chief hospital executives are required in order to heighten the results of hospital information systems, and there must be participations of organization members in their construction and performance. Also there must be training and education of members in the hospital affairs in using them. In such a condition of hospital organizations the good results of hospital information systems will be produced. The above concluded things must be taken into consideration importantly in their introduction and development.

• Proceedings of the ESK Conference
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• 1993.10a
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• pp.165-188
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• 1993

The study was to find out the current situation of supply and demand of apparel CAD systems in Korea. Also it was hoped to gather any valuable information about the curent usage of appared CAD systems for the development of the enhanced apparel CAD system. Three interviews were carried out for the study. The first interview with the importing agents was to find out the apparel CAD system's supplying situation. The second interview with the users of apparel CAD system was about the usage of the systems and related informations. The last interview was about the pattern making facilities, which was pointed out by the users to be the most inconvenient prat of apparel CAD systems. The results of the survey were:- 1. The supplu and demand of apparel CAD systems is increasing. 2. The education, training, maintenance of the system should be improved by the supplier. 3. Apparel CAD systems are used for various production systems in the apparel industry. 4. 100% of the systems are utilized for pattern input and 89% of the systems are utilized for marker making. Only 15% of the systems are utilized in pattern making process, which 80% of the users realize to be computerized. 5. The most serious barrier to the better usage of the system is the communication with the system in foreign language. This barrier could be lifted when Korean apparel CAD system is developed.