• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.436-438
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• 2007

As the sensors and communication technology get advance, the remote health diagnosis for patients and senior persons at home are possible now without visiting doctors in hospitals. A low-power ubiquitous health check device was developed adapting Real-Time Embedded Linux is developed. This ubiquitous device is consisted of three sensors. The wrist type health checking terminal acquires periodically the health data by using a blood pressure sensor, a pulse sensor and a body temperature sensor. It transmits the health data to the access point located at the home center through the ZigBee wireless communication modem. This health data collector or access point device sends the data again to the main server operated in a hospital or health care organization. The health server control continuously the input data and sends an alarm signal to the assigned. doctor and responsible persons using cellular SMS when any dangerous events occur. This wrist type health check device has an embedded linux OS using Intel PAX255 MPU. The developed U-Health system is applicable for checking patients health in remote at home. And their family or related persons in remote site can check the patients health status at any time. They can be assured by receiving SMS record and alarm of emergency case which is transmitted from the health server.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.361-367
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• 2020

This paper proposes the battery-less ultra-low-power self-powered cooperating artificial neural networks device for embedded and IoT systems. This device can work without extraneous power supplying and can cooperate with other neuromorphic devices to build large-scale neural networks. This device has energy harvesting modules, so that can build a self-powered system and be used everywhere without space constraints for power supplying.

• Journal of Digital Contents Society
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• v.15 no.3
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• pp.433-438
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• 2014

In this paper, we proposed the low power algorithm consider the battery and the task. The proposed algorithm setting the power consumption of unit time consider the capacity of the battery and the target time. Calculate the power consumption of all tasks. Calculate the average power consumption by the task have maximum power consumption and the task have minimum power consumption. Recalculate average power consumption consider the unit time of task. Compare calculated average power consumption and average power consumption of task. Compared results, low power algorithm processing the average power consumption less than or equal calculated power consumption of task. Low-power algorithm is greater than the average power consumption of the task to perform targeted tasks. Low-power processors and the task by dividing the power consumption of the device in large part for the low-power consumption is performed. Experiments [6] were compared with the results of the power consumption. The experimental results [6] is reduced power consumption than the efficiency of the algorithm has been demonstrated.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.103-111
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• 2008

One of the most popular internal combustion engines is the engine in the transportation device. Power is a parameter that shows the capabilities of an object that gives energy, for example the internal combustion engine. Power in this engine is measured by a device called dynamometer. The CFD (Computational Fluid Dynamic) fluent software was simulated several impeller variables to absorb power of engine. With that result, we knew the biggest dynamometer absorber power, cheapest and easy to be made. The hydraulic dynamometer is selected type of dynamometer as the result of design process. The basic principle of a hydraulic dynamometer is the same as centrifugal pump but it has low pump efficiency. The results of the test are maximum power and torque of the tested engine and the operation area of the selected hydraulic dynamometer.

• ETRI Journal
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• v.34 no.1
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• pp.134-137
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• 2012

Power metal-oxide semiconductor field-effect transistor (MOSFET) devices are widely used in power electronics applications, such as brushless direct current motors and power modules. For a conventional power MOSFET device such as trench double-diffused MOSFET (TDMOS), there is a tradeoff relationship between specific on-state resistance and breakdown voltage. To overcome the tradeoff relationship, a super-junction (SJ) trench MOSFET (TMOSFET) structure is studied and designed in this letter. The processing conditions are proposed, and studies on the unit cell are performed for optimal design. The structure modeling and the characteristic analyses for doping density, potential distribution, electric field, width, and depth of trench in an SJ TMOSFET are performed and simulated by using of the SILVACO TCAD 2D device simulator, Atlas. As a result, the specific on-state resistance of 1.2 $m{\Omega}-cm^2$ at the class of 100 V and 100 A is successfully optimized in the SJ TMOSFET, which has the better performance than TDMOS in design parameters.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.196-200
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• 2015

The switching noise in the power electronics of the power conversion equipment (Power Conditioning System) for large energy storage devices are generated. Since the burst-level transient noise from being generated in the power system at a higher power change process influences the control circuit of the low voltage driver circuit. Noise may cause the malfunction of the control device even if no dielectric breakdown leads to a control circuit. To overcome this, this paper proposes the installation of an additional nano-surge protection device on the power supply DC output circuit of the battery management unit.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.360-364
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• 1995

A zero voltage switching (ZVS) three level resonant pole inverter is presented for high power GTO inverters. The concept of auxiliary resonant commutated pole(ARCP) for two level inverter is extended to the three level inverter. The proposed auxiliary commutation circuit consists of one resonant inductor and two bi-directional switches, which provides ZVS condition to the main devices without increasing device voltage or current stresses. The auxiliary device operates with zero current switching(ZCS) which enables use of the low cost thyristors. The proposed circuit can handle higher voltage and higher power(1-10MVA) comparing to the two level one. Operation and analysis of the proposed circuit are illustrated. Experimental results with 10 KW, 4 kHz prototype are presented to verify the principle of operation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.9
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• pp.75-79
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• 2011

The MOV(Metal Oxide Varistor), a voltage limiting element, has been installed in the SPD(Surge Protective Device) or inside the internal circuit of an electronic appliance for protection of the electric power system and electronic device against electrical surge. Such an MOV is exposed, however, to the risk of the thermal runaway resulting from excessive voltage and deterioration. In this paper, a reciprocal action has been tested and analyzed using a phosphorus bronze switching module and the low-temperature solder. And a short current break characteristic test linked with the circuit breaker has been performed to limit the inrush current when the MOV breaks down. It has been proven that the phosphorus bronze switching module installed inside the internal circuit can improve the safety of the power line system and the electronic device.

• Journal of the Korean Physical Society
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• v.73 no.12
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• pp.1889-1894
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• 2018

An innovative small-scale piezoelectric energy harvester has been proposed to gather wind energy. A conventional horizontal-axis wind power generation has a low generating efficiency at low wind speed. To overcome this weakness, we designed a piezoelectric windmill optimized at low-speed wind. A piezoelectric device having high energy conversion efficiency is used in a small windmill. The maximum output power of the windmill was about 3.14 mW when wind speed was 1.94 m/s. Finally, the output power and the efficiency of the system were compared with a conventional wind power system. This work will be beneficial for the piezoelectric energy harvesting technology to be applied to the real world such as wireless sensor networks (WSN).

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.485-488
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• 2000

This paper proposes to design the residential power line communication device using Softwire Protocol, which targets the device with 8bit micro-controller and small-size memory based on low-rate power line communication network or wireless communication network. As a case study, the SCP message specification of air-conditioner that has capability of control and monitoring its status is designed using Softwire Protocol. And, it is described how the device operates sequentially.