• Journal of the Korean Society for Precision Engineering
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• v.30 no.2
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• pp.185-193
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• 2013

The construction automation provides safer and more productive working environment of construction site. We developed the automation system of bolting operation for high-rise building in the previous research. However, this system has a weak point that the operation has to be processed in the air with the operator in the cabin. This weakness leads operators to considerably dangerous environment. Therefore, we proposed the tele-operation system in order to supplement this weak point. Furthermore, it leads more effective operation by application of more intuitive controller; spherical coordinate based Master Arm than the joystick in the Mobile Bolting Robot system. These proposed system and controller were evaluated based on Fitts' law paradigm, which is a general estimation method of speed accuracy of task. Through the experimental results, new developed tele-operation system is compared with the actual operation and it discloses distinctions between two systems. As a result, it is found that new developed teleoperation system can be possible to replace the operation in the cabin.

• Journal of the Korean Solar Energy Society
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• v.29 no.5
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• pp.14-19
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• 2009

The 50 kWp grid connected photovoltaic system which was installed at KEPRI site in 1999 has been operated more than 10 years. In order to acquire long term operation characteristics of medium size photovoltaic system, the operation test data related on power generation electricity and capacity factor of 50 kWp system, which have been collected since 1999, were analysed. From the analysing results, 57.7 MWh in annual power generation electricity of 50 kWp photovoltaic system in 1999 has been decreased 49.1 MWh in 2005 and reached 41.9 MWh in 2008. In addition to, the capacity factor of 50 kWp photovoltaic system also showed 13.2 % in 1999, 11.2% in 2005 and finally reached 9.6% in 2008. The operation test data showed a trend of decreasing of generation electricity and capacity factor during the 10 years operation time and we guessed that was caused by solar cell performance degradation and decreasing of PCS system efficiency.

• Journal of Korean Public Health Nursing
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• v.19 no.1
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• pp.148-160
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• 2005

Presented here are policy alternatives for understanding home health care for the long-term health care insurance system which is being developed for elderly people starting 2007. The summary of issues concerning home health nursing care under the long-term care insurance system include; 1) absence of comprehensive and systematic policy in home health care deliverly systems; 2) absence of community based home health agencies that are considered as the community residents in general. In order to overcome these problems and Issues, policy alternatives of home health care should 1) establish a comprehensive home health care policy for homebound persons; 2) establish the foundations for home health care nurses and community based home health care systems; 3) establish home health care facilities and infrastructure; and 4) promote research and development concerning home health care. Conclusively, a home health care system should be built on a comprehensive policy vision based on health policy, especially long-term care insurance system in the near future. Every homebound residents service has to be constructed systematically under suitable facilities considering the consumer characteristics and health conditions. By doing this, the consumer based comprehensive community home health care delivery system can be constructed in view of the long-term health care insurance system for elderly people.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.89-97
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• 2022

The growth of online market is accelerating due to the development of technology and the era of pandemic. In order to deliver the ordered product to customers courier service should be used. In addition, the courier logistics market is growing with the growth of the online market. With the growth of the logistics market, traffic and environmental problems are emerging as social issues. Logistics technology of urban community logistics courier terminal system utilizing vacant space in the city has been developed as a new alternative to environment and traffic problems by increasing logistics efficiency in the city area. In this study, we propose a concept of a system that performs operational concept definition and scenario analysis by applying model-based perspective analysis to urban community logistics courier terminal system under development. Through this study, we defined the operating concept of the urban community logistics courier terminal, which is the target of development, and defined the scenario for system operation by grasping the structure and function of the system and applied it to system development.

• Journal of the Korean Society of Systems Engineering
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• v.13 no.2
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• pp.65-74
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• 2017

Supercritical carbon dioxide power system is the next generation electricity technology expected to be highly developed. The power system can improve net efficiency, simplify cycle configuration, and downsize equipment compared to conventional steam power system. In order to dominate the new market in advance, it is required to found Front End Engineering Design (FEED) Framework of the system. Therefore, this study developed the FEED framework including design processes for the supercritical carbon dioxide power system, information elements for each process, and relationships for each element. The developed FEED framework is expected to be able to secure systematic technological capabilities by establishing a common understanding and perspective among multi-field engineers participating in the design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.458-462
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• 2004

The hydraulic system for discharging compressed gas is composed of compressor tank, proportional flow control servo valve, expulsion spool valve and discharging tube. Purpose of this study is to control of expulsion spool valve. First, we analyzed the hydraulic system. The flow control servo valve is modeled as a 2nd order transfer function and friction force of the expulsion spool valve is modeled as nonlinear model with stribeck effect. However, it is difficult to include the flow reaction force in modeling. So, we exchanged from the simplified flow reaction force of the compressed gas affection into the flow analysis code written in FORTRAN code. Our simulation of the oil pressure system for discharging gas used MATLAB/Simulink. So, we realized ＆apos;Level -2 S-Function Fortran＆apos; to cooperate for MATLAB/Simulink and FORTRAN code. PD controller is selected to control in this system. Simulation results show that with given conditions the controllers give a good tracking performance.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.8
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• pp.140-147
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• 2015

In this paper, we propose a state feedback robust controller of 2-axis gimbal system which have bounded parametric uncertainty. The proposed controller is robust against dynamics variations of gimbal system and contains a dynamic compensator in order to improve a steady state error and a transient response. The stability of the closed-loop system is proved by Lyapunov approach. The performance of the proposed method is demonstrated by simulation on a 2-axis gimbal system.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.261-268
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• 1998

The productivity of port labor in Pusan port is very low and the ratio of port accident is high in comparision with other advanced foreign ports. The aim of this paper is to find why the productivity in Pusan port is much lower than that of other countries in terms of port labor education systems. To obtain the objective of this study, the writers used 163 questionnaire for port labor in BCTOC, PECT and UTC for the survey of training method of cargo equipment handling. The result of this study shows as follows; (1) From the fact that ratio of labor who were trained by KPTI was 2.5%, we could say the public training system of port labor is not operated properly (2) As most of laborers are trained by the experienced associate, they do not recognize how the level of cargo handling equipment is set to increase the productivity. (3) In order that the port public training system plays a good role in port industry, a new license system should be introduced and an expert education system should be developed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.36-42
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• 1997

A prototype of 500Wh class flywheel energy storage device was designed and manufactured to check the previously predicted system performance. The system was intentionally designed to show rigid body behavior up to the maximum operating speed of 60000Tpm and to have its 2nd rigid critical mode, of which nodal point lies on the flywheel center of mass, around 4000 to 6000rpm with radial magnetic bearing stiffness of l.e+6 N/m. Numerous experiments an the system behavior showed that the PM axial bearing, designed utilizing a commercial code, acts as resonably as predicted and, most importantly, the system becomes stable after the 2nd critical speed. The EM radial bearing, however, was found out to have orthotropic property with much less radial stiffness values than expected, so that it was observed that the 2nd forward and backward critical modes were excited at 310 and 590rpm respectively with larger vibration amplitudes. Thus, in order to improve the system dynamic behavior, the EM radial bearing is currently being re designed so as to get bigger stiffness and, in turn, smoother operation of the system.

• Journal of the Korean Solar Energy Society
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• v.39 no.3
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• pp.1-7
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• 2019

As part of the government's energy policy, Zero Energy Building certification was launched on January of 2017. However, the three passive-housing rental housing projects are the only ZEB-certified detached housing since the certification's launch. The reason is that, in order for a detached housing to earn ZEB certification, it has to secure self-reliance in energy, and a photovoltaic system is the only viable renewable energy system. Therefore, conducting an analysis to optimize the photovoltaic system in an early design stage is strongly recommended. This study aimed to propose an optimal photovoltaic system design for a detached housing after analyzing through the ECO2 energy simulation of 44 cases, varying in a module type and efficiency, inclination and azimuth. As a result, 15 cases out of 44 cases were analyzed to satisfy ZEB evaluation criteria, and it is thought that these data could contribute greatly to the expansion of ZEB certification dissemination.