• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.325-327
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• 1995

A new gate drive circuit of classic converter for a switched reluctance motor is presented. Conventional gate drive circuit usually consists of the isolated power supplies and signal transferring devices for isolation, such as photo coupler, pulse transformer, and gate drive chips. The proposed gate drive circuit consists of resistors, capacitors, and zenor diodes without isolated power supplies, that make the drive circuit simple and reduce the material cost. The operational modes are classified and analyzed. The characteristics of the phase current and the gate signal of upper switches is investigated with the variation of duty ratio through the experiments.

• The Journal of the Korea Contents Association
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• v.20 no.4
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• pp.284-294
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• 2020

As a solution to local and social problems, the active use of smart city living labs is becoming increasingly important. The answer to solving local and social problems lies in the citizen and the field. The purpose of this study is to establish a smart city living lab model based on citizen participation. In this study, smart city living lab model(4P-SCLLM) based on citizen participation was established through domestic and overseas living lab methodology and case analysis. In order to evaluate the systemicity and specificity of the 4P-SCLLM, a smart city living lab model, we recently compared it with the living lab process in Busan where smart city living lab is applied. As a result of analyzing, the analysis shows similar trends in each stage, and Busan's private sector showed a similar process to 4P-SCLLM On the other hand, public and private sector cooperation and support systems were found to be less than the 4P-SCLLM model And In technology and methodology, the 4P-SCLLM model is analyzed to have a living lab process that incorporates new technologies. In order to maintain the 4P-SCLLM continuously, first, participants and stakeholders need to participate actively and communicate while collaborating on the whole process from start to finish. Second, public awareness needs to be improved. Third, continuous citizenship verification of services is needed. Fourth, citizens' constant participation is needed. Through these implications, this study proposed 4P-SCLLM as a smart city living lab model suitable for the domestic situation.

• Journal of Korea Technology Innovation Society
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• v.17 no.2
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• pp.309-333
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• 2014

To meet the challenge of new type of innovation activities requires us to understand the social context of innovation and the potential needs of innovation users and, based on this, to co-construct technology and society simultaneously. Effective 'demand articulation' activities such as the understanding and utilization of user experiences and socio-technical planning are prerequisites for carrying out post-catch up innovations shaping new trajectories and contributing to solving social problems. Living Lab has recently been emerging particularly in Europe as an 'user-driven innovation model', in which users are active participants in innovation activities. The purpose of this study is to contribute to a theoretical discussion of Living Lab as an user-driven innovation model, to make a brief review of cases of Living Lab and to explore Living Lab's applicability in the Korean context. Living Lab is an open innovation model, in which end suers actively participate in innovation processes in a particular geographical space or region and would be able to solve specific problems of that space or region. In that sense, Living Lab would be able to strengthen the problem-solving capabilities of local communities and to become a pioneer in inducing and realizing a new socio-technical system. Furthermore, Living Lab could become an innovative policy tool reflecting recent major changes in innovation policy paradigms such as post-catch up innovation, demand-oriented innovation, regional innovation, societal innovation, innovation eco-system and socio-technical system transition, and thus make a contribution to exploring a new way of bringing about changes in the Korean society.

• Journal of Korean Society for Quality Management
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• v.50 no.4
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• pp.679-700
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• 2022

Purpose: Smart lighting adjusts brightness and color temperature according to weather, the user's activity, mood, etc. This study performed user experience(UX) evaluation of smart lighting in a living lab. The purpose of evaluating UX and analyzing the evaluation results is to improve user-friendliness and market competitiveness of smart lighting Methods: A living lab is a virtual or physical space where various stakeholders participate to develop, verify, and evaluate products, services, or systems in a real-life environment. In this study, an environment of using smart lighting was established in the Smart Safety Living Lab. Subjects performed UX evaluation after interacting freely with smart lighting in the Smart Safety Living Lab. Results: As a result of UX evaluation, it was confirmed that UX was overall excellent and subjects were satisfied with setting a desired indoor mood through smart lighting. However, operating the switch of smart lighting may be difficult due to its complexity, and it is needed to improve some functionalities such as the brightness range provided by smart lighting. Conclusion: This study is expected to contribute to establishing the way of UX improvement of smart lighting. This study is also expected to contribute to developing smart lighting as a high-quality product by reflecting the subjects' needs and UX derived in a real-life environment.

• Journal of Science and Technology Studies
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• v.15 no.1
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• pp.245-279
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• 2015

The new innovation model that deals with agenda as sustainability, quality of life, societal challenges is emerging as NIS(National Innovation System) is needed to transit to post catch-up and creativity. To achieve this objective, there is a growing need for enhancing usage of ICT, end-user's needs, prolification of R&D results and social impact. Living Lab is the new innovation model that end-user's participation, co-work/network within actors and usage of user's experience and This study deal with Living Lab related R&D of ICT-based service from co-work with end-users. Example cases are Turku Archipelago Living Lab in Finland, and Living Lab projects in EU, EIT ICT Labs and ELLIOT. And the focus of case analysis is that reflection of user's needs and experience, and aspect of ICT usage.

• Journal of Industrial Convergence
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• v.18 no.5
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• pp.102-107
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• 2020

The purpose of this study is conduct development and assessment of the on-site customized education program in college curriculum with utilizing Living Lab. The development process is conducted in Living Lab's mechanism ; idea expression, setting agenda, actual activities, and feedback. The developed early education program is constructed four subjects, sixteen sub themes, and fifty three activities. For the assessment of the program, the satisfaction survey was conducted to sixty eight teachers who work for early education institutes in Busan, S. Korea. In the result, more than 80% of respondents answered that the program was satisfying. The study is meaningful as a basic data to utilize Living Lab in various subjects and majors in college.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.302-304
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• 1996

In this paper, a new algorithm for sensorless speed control of switched reluctance motor (SRM) is proposed. It is based on the measurement of initial rate of change of phase current. The initial rate of rise of phase current mainly depends up on the phase inductance at the time instant when the phase is excited. Therefore, the measurement of initial di/dt permits rotor position estimation, which is used to trigger the next phase. In the proposed technique, there is no need to generate additional current pulses when a phase is not excited. Therefore, this scheme does not introduce the unwanted braking torque. Also, only one current measurement is made every time a phase is excited. This reduces the computational load on the micro-controller and enhances the speed range of the sensorless drive. By using this scheme it is possible to implement the sensorless control of SRM using low cost micro-controller.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.1951-1953
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• 1997

A switched reluctance motor (SRM) has very simple structure and robustness. Generally, for driving SRM, several (6-8) switching devices are required. This is weakpoint for reducing the cost of SRM drive. In This paper, we simulate the single phase and three phase SRM, and we compare the performance or single phase SRM with that of three phase SRM through experiment. Finally we suggest the appropriate application of single phase SRM.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.28-30
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• 1996

In the paper the authors deal with inverter fed induction motors design criteria for having a wide constant power range. In particular, the flux weakening operation is the main feature considered. The design target concerns the possibility of having a wide flux weakening region avoiding or limiting, at the same time, to oversize the motor and the inverter.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1908-1910
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• 1998

지금 까지 유도 가열용 인버터의 여러 가지 회로 방식이 소개 되었다. 그러나, 회로 방식을 선정 하는데 있어서 설계자의 취향, 또는 종래의 회로을 채택으로 인하여, 각기 다른 출력, 스위치 소자의 정격 전압, 전류, 및 수동 소자의 정격 전압, 전류을 만족하는 회로 선정이 될 수 있는 수식적 모델링, 비교 실험이 부족 하였다.