• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.33-33
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• 2000

In this paper a new distributive control system for BA(Building Automation ) lighting control used on general microprocessors is presented. For optimal lighting control and saving energy, The system have to control the group and pattern lighting control as well as individual light control at one time. Tn this paper, This functions are accomplished with low-cost and simple microprocessor. A plurality of modulated light control terminals are connected to the central control unit through a pair of power line. This power line provide both power and signal to the each terminal and the data is transmitted through cyclic time division multiplex transmission. With this structure a low-cost distributive control system for lighting applications has been achieved, allowing energy and maintenance saving and reliability increase of the light control system.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1075-1080
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• 2007

In order to reduce energy consumption, secondary controlled system has been applied to many types of equipments. In lifting equipments or press machines using hydraulic cylinder, a hydraulic transformer is used as a control component instead of a valve for motion control and a component for recovering potential energy of load. The transformer is a combination of a variable displacement pump/motor as a secondary controlled element and a fixed displacement pump/motor. In this paper the effect of transformer is studied. Multiple closed loop controllers with displacement feedback of variable pump/motor, speed feedback and position feedback of cylinder are used. The efficiency and energy consumption when cylinder is driven up and down is calculated by simulation. Simulation results show that considerable energy saving is achieved by choosing load ratio, circuit type and supply pressure.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1159-1165
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• 2010

This paper describes an energy efficient train control. In these days, the researchers develop the energy efficient railway technologies, such as energy storage system, energy efficient driving. Mass rapid transit (MRT) railways, which are an important means of public transportation in urban areas, have operational characteristics that include short headways, frequent departures and arrivals. Therefore, when multiple trains are operating in the same power supply system, it is important to synchronize the energy tractions and regenerations. This paper define the group of trains for energy saving according to a power supply. We analyze the current synchronized driving situations and estimate the effect.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1925-1932
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• 2016

One of the major challenges in the design of wireless sensor network (WSN) is to reduce the energy consumption of sensor nodes for prolonging the network lifetime. In the sensor network, communication is the most energy consuming event. Therefore, most of the energy saving techniques conserve energy by adjusting different parameters of the trans-receiver. Among them, one of the promising methods is the transmission power control (TPC). In this paper, we investigated the effects of the link quality based TPC scheme employed to the IEEE 802.15.4 standard for energy saving. The simulation results demonstrated that the link quality based TPC scheme works effectively in conserving energy as compared to the conventional IEEE 802.15.4.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.131-139
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• 2018

Many ship researches have been carried out in connection with the fourth revolution, one of which focuses on EMS(energy management system). The EMS is referred to as systems for managing the energy of ships and include various systems. In this paper, we analyze the energy saving field in ship and propose a ship power energy management system including individual load control systems that can save energy in the engine room. EMS includes individual load control systems of PCS (Pump Control System), ERFCS (Engine Room Fan Control System), LCS (Load Control System), HVACS (Heating, Ventilation, Air conditioning Control System). Proposed EMS primarily conserves energy in the individual load systems of the engine room. Secondly, the integrated monitoring and control system is used to control the power generation system and the power load system to save energy.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.10
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• pp.656-661
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• 2011

The amount of water resources that can be used tend to be decreased gradually. In contrast, the rapidly increasing water consumption is a problem that need to be addressed. Renovation and equipment replacement to improve energy efficiency and to reduce expenditure for building usage is required. But the excessive initial investment cost and the prolonged of pay back period may be uneconomical choice. Water usage for cleaning the toilet bowl accounts for 27%of the total water usage. Water-saving valve that can select the amount of water for cleaning toilet bowl can be reduced expenditure. After installing water-saving valve, analysed the economic effects. Water-saving valves compared with flush valves, and researched the amount of water usage. Then analyzed for the economic effects. Water-saving valve was used 5.6 ${\ell}$/time for cleaning toilet bowl. In contrast, flush valve was consumed 8.4 ${\ell}$/time. Water-saving valve's water-saving rate was 33.3%. The initial payback period for Water-saving valve was 459.5 days. By a small investment in water saving valve, the economic benefits can be obtained.

• JOURNAL OF ELECTRICAL WORLD
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• no.12 s.132
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• pp.23-30
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• 1987

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.203-205
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• 2006

This paper presents a novel soft-switching PWM utility frequency AC to high frequency AC power conversion circuit incorporating boost-half-bridge inverter topology, which is more suitable and acceptable for cost effective consumer induction heating applications. The operating principle and the operation modes are presented using the switching mode and the operating voltage and current waveforms. The performances of this high-frequency inverter using the latest IGBTs are illustrated, which includes high frequency power regulation and actual efficiency characteristics based on zero voltage soft switching (ZVS) operation ranges and the power dissipation as compared with those of the previously developed high-frequency inverter. In addition, a dual mode control scheme of this high frequency inverter based on asymmetrical pulse width modulation (PWM) and pulse density modulation (PDM) control scheme is discussed in this paper in order to extend the soft switching operation ranges and to improve the power conversion efficiency at the low power settings. The power converter practical effectiveness is substantially proved based on experimental results from practical design example.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.387-390
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• 2006

This paper presents a novel soft-switching PWM utility frequency AC to high frequency AC power conversion circuit Incorporating boost-half-bridge inverter topology, which is more suitable and acceptable for cost effective consumer induction heating applications. The operating principle and the operation modes are presented using the switching mode and the operating voltage and current waveforms. The performances of this high-frequency inverter using the latest IGBTs are illustrated, which includes high frequency power regulation and actual efficiency characteristics based on zero voltage soft switching (ZVS) operation ranges and the power dissipation as compared with those of the previously developed high-frequency inverter. In addition, a dual mode control scheme of this high frequency inverter based on asymmetrical pulse width modulation (PWM) and pulse density modulation (PDM) control scheme is discussed in this paper in order to extend the soft switching operation ranges and to improve the power conversion efficiency at the low power settings. The power converter practical effectiveness is substantially proved based on experimental results from practical design example.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.6
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• pp.516-522
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• 2012

Recently trends of home appliance has been changed in house and the demand for functional refrigerator has been increased. Power consumption of refrigerator accounts for a large proportion in consumer electronics. Also, compressor accounts for most of the power consumption in refrigerator parts. Therefore, this paper proposes a multi-refrigerator system with single compressor & condenser fan in order to reduce energy. To verify the availability of the proposed multi refrigerant system, integration experiment is carried out.