• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.371-374
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• 2004

Induction motors are a critical component of many industrial processes and are frequently integrated in commercially available equipment. Safety, reliability, efficiency, and performance are some of the major concerns of induction motor applications. Preventive maintenance of induction motors has been a topic great interest to industry because of their wide range application of industry. Since the use of mechanical sensors, such as vibration probes, strain gauges, and accelerometers is often impractical, the motor current signature analysis (MACA) techniques have gained murk popularity as diagnostic tool. Fault tolerant control (FTC) strives to make the system stable and retain acceptable performance under the system faults. All present FTC method can be classified into two groups. The first group is based on fault detection and diagnostics (FDD). The second group is independent of FDD and includes methods such as integrity control, reliable stabilization and simultaneous stabilization. This paper presents the fundamental FDD-based FTC methods, which are capable of on-line detection and diagnose of the induction motors. Therefore, our group has developed the embedded distributed fault tolerant and fault diagnosis system for industrial motor. This paper presents its architecture. These mechanisms are based on two 32-bit DSPs and each TMS320F2407 DSP module is checking stator current, voltage, temperatures, vibration and speed of the motor. The DSPs share information from each sensor or DSP through DPRAM with hardware implemented semaphore. And it communicates the motor status through field bus (CAN, RS485). From the designed system, we get primitive sensors data for the case of normal condition and two abnormal conditions of 3 phase induction motor control system is implemented. This paper is the first step to drive multi-motors with serial communication which can satisfy the real time operation using CAN protocol.

• The KIPS Transactions:PartA
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• v.14A no.2
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• pp.99-106
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• 2007

Grid computing, a mechanism which uses heterogeneous systems that are geographically distributed, draws attention as a new paradigm for the next generation operation of parallel and distributed computing. The importance of grid computing concerning communication cost is very huge because grid computing furnishes uses with integrated virtual computing service, in which a number of computer systems are connected by a high-speed network. Therefore, to reduce the execution time, the scheduling algorithm in grid environment should take communication cost into consideration as well as computing ability of resources. However, most scheduling algorithms have not only ignored the communication cost by assuming that all tasks were dealt in one cluster, but also did not consider the overhead of communication cost when the tasks were processed in a number of clusters. In this paper, the functions of original scheduling algorithms are analyzed. More importantly, the functions of algorithms are compared and analyzed with consideration of communication cost within the co allocation environment, in which a task is performed separately in many clusters.

• Journal of KIISE:Software and Applications
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• v.37 no.1
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• pp.19-28
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• 2010

Recently, various home appliances are inter connected in wired/wireless network to provide a single service, but their interfaces are not uniformly integrated. In order to get a service in such an environment, users have to figure out how to control each appliance and the way of combining its functions with others. Even worse to the users, many buttons are barely used to control the complicated functions of the appliances on the remote controllers, and controllers have very similar shapes in each other. In this paper, based on the definitions of a task as a unit of services provided in the environment of multi-connected appliances, we propose a markup language for home appliances, called HAML (Home Appliance Markup Language), for generating task-based user interfaces to help controlling multi-connected appliances as one pleases. The proposed method generates interfaces by gathering the buttons frequently used and necessary for tasks, and provides automatic settings of multi-connected appliances. The proposed method is verified with an analysis of scenarios and usability tests.

• Journal of Internet of Things and Convergence
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• v.5 no.2
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• pp.73-79
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• 2019

Research is underway on services and systems that provide real-time alerts for suffocating gases and potentially explosive materials, but currently smart bend type services are lacking. This study supports real-time identification of explosion hazards due to static electricity in the workplace and immediate elimination of accident occurrence factors, real-time monitoring of worker status and workplace hazards (oxygen, hazardous chemical concentration), and immediate warning and data in case of danger. We propose a method of establishing an accident prevention system through analysis. In this way, various accidents that may occur in industrial sites are monitored using IoT-based intelligent sensor nodes, wireless network technology, data processing middleware, and integrated control system, and real-time risk information at the industrial sites is prevented and accidents are prevented. By supporting a safe working environment, the company can significantly reduce costs compared to post-procurement costs.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.277-279
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• 2005

Recently, due to the increase of power conversion devices and nonlinear loads with the development of information, communication and control technologies, the instantaneous minute interruption factors such as voltage & current harmonics, surge occurring frequency, instantaneous voltage variation, voltage unbalance, flicker etc. have greatly threatened the power quality, and the deterioration of electric power facilities and the functional error of controllers are increasing. As such an instantaneous minute interruption appears to be small and local, accurate evaluation with measurement is difficult and total analysis system is required through a wide range of power quality effect analysis such as the simultaneous measurement on various power supply phenomena and the analysis on the interrelation with system loads. Most of conventional power quality diagnosis equipments have beer developed and applied, which were able to measure the stability rate of frequency, the stability rate of voltage, the electricity-failure duration etc, However, they were insufficient to analyze the system present situation, understand the cause of the failure occurred by the problem of power quality and analyze out the phenomena. Accordingly, this study will address the development of the system for a wide range of power quality diagnosis over the present level, the system for supporting the determination such as the analysis on risk factors, failure mode and impact, the system for harmonic evaluation based on international standards(IEC 61000 Series) and the total power quality diagnosis network & system with the extension and openness as a local and national-scale broadband power quality diagnosis system.

• Journal of the Korean Society for Railway
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• v.17 no.1
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• pp.35-42
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• 2014

This paper analyzes the hazard related to train control, the functional requirements for atrain control system(TCS) and the automatic train protection(ATP) functional allocation that ensures the interoperability of a radio communications-based TCS. In addition, the interoperability can be obtained using wireless communications technology standards and standardized functional allocations of TCS performed on the wayside and onboard. Using this information, an integrated operating system for a rail network can be constructed. The functional allocations of TCS that support interoperability, require hazard analysis of TCS and definition of the system requirements. The hazard factors for a TCS are confirmed through setting the train safety space control and train speed limit excess. Furthermore, this paper determines the impact of the hazard factors on the TCS and, defines the functional requirements for the TCS subsystems and the ATP wayside and onboard functional allocations.

• Journal of Family Resource Management and Policy Review
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• v.17 no.3
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• pp.125-144
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• 2013

This aim in this study is to investigate the meaning of case management and management in general from the case manger's perspective, as well as case mangers' abilities and networks. We also propose a development direction for the establishment of a local integrated family-centered community management system. Regarding the collection of qualitative data, focus group interviews (FGIs) were conducted with 11 case managers from social welfare organizations in the city of C. The interviews consisted of open-ended questions in the following four categories: understanding of case management, case managers' abilities, case management environments, and local community networks. According to the interview analysis, a total of 16 subcategories in 9 categories and 4 domains have been identified. Due to the ambiguity regarding the concept of case management, case management was completely dependent upon individual case managers' abilities. In particular, family-centered case management was found to exist in several organizations in the same region. In terms of case management environments, the following problems have been observed: absence of related departments and staff, confusion regarding performance evaluation standards, limitations in sharing information among organizations, limitations in resource exploration and management, redundant support, and an uncomfortable relationship between the private and public sector. Horizontal exchange and cooperation among organizations are essential to establish and facilitate a local community network. After all, to establish a local family-centered community case management system, the roles of a Healthy Families Center and a Multi-cultural Family Support Center as parts of a family-centered transfer system should be fully emphasized in local society, and the performance of family-centered case management should be developed.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.21-26
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• 2018

In this study, HRD-NET (http://hrd.go.kr), a vocational and training integrated computer network operated by the Ministry of Employment and Labor, is used to confirm whether job training information required by job seekers is being provided smoothly The question bulletin board was extracted using 'R' program which is optimized for big data technique. Therefore, the effectiveness, appropriateness, visualization, frequency analysis and association analysis of the vocational training system were conducted through this, The results of the study are as follows. First, the issue of vocational training card, video viewing, certificate issue, registration error, Second, management and processing procedures of learning cards for tomorrow 's learning cards are complicated and difficult. In addition, it was analyzed that the training cost system and the refund structure differentiated according to the training occupation, the process, and the training institution in the course of the training. Based on this paper, we will study not only the training system of the Ministry of Employment and Labor but also the improvement of the various training computer system of the government department through the analysis of big data.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.5
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• pp.168-177
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• 2009

This paper proposes the EAP-AKA scheme without UICC for extending its usage to existing WLAN/WiBro devices. To apply the current EAP-AKA scheme, the WLAN/WiBro devices require an external Universal Integrated Circuit Card (UICC) reader. If they don't use UICC due to cost overhead and architectural problem of device, the EAP-AKA scheme loses its own advantages in security and portability aspects. The proposed scheme uses the DH key algorithm and a password for non-UICC devices instead of using the long-term key stored in UICC. The main contribution is to maintain the security and portability of the EAP-AKA while being applied to non-3GPP network devices not equipped with UICC. Furthermore, it does not require major modifications of authentication architecture in 3GPP.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.209-214
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• 2014

IMS(IP Multi-Media Subsystem) is in the limelight as the Integrated wire and wireless Systems because of a sudden increase of smart mobile devices and growth of multimedia additional services such as IPTV. The structure of IMS is designed as a session control layer to provide various multimedia summative service using SIP based on IP communication network in order to carry out set-up, change and release by NGN of course, the existing voice services. But now It is broadly substituting in the IPTV, wire phone company and it is substituted in internet platform base on the soft-switch in currently. Especially, in currently, 4G LTE in a mobile communication company is rapidly growing in market. Therefore, in this study, we had designed and developed to the main prosser that can admit to 1000 user over and SIP gateway which can link the IMS Core that can link SIP Device which adopt the standard protocol on the SIP and to provide variable multimedia services.