• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.1967-1977
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• 2014

In this paper, for the development of a safe and reliable DC home appliance suitable for DC home power supply system, we classified a number of inherent problems with help of the comparative analysis of existing AC and new DC home appliance. Several new technical problems of DC home appliances are mainly linked to the DC transient state. Among them, this paper concentrates on start-up inrush current problem, uni-polarity problem, and heavy DC load control problem. And to address these problems, we herein present an implementation of robust safety circuits for DC home appliances. Specifically, we investigate several multi-circuit countermeasures and select the best among them through comparative evaluation, based on theoretical, simulational, and experimental results.

• Korean Journal of Human Ecology
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• v.14 no.4
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• pp.693-707
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• 2005

This study investigates the over time changes in the ownership of kitchen items, electric or non-electric, and examines the patterns of the usage and ownership of the items after categorizing them as followings: cooking appliances, kitchen appliances directly related to storing food, food processing kitchen items, and dining items. The research findings are that refrigerators and rice cookers, among the electric items, had spread to almost every households by 1990s and at the same time about thirty non-electric kitchen items had been used. Refrigerators had been used by more than 100% of the households by 2000, and on top of that, twenty or more electric kitchen items such as Kimchi fridge and freezer had been used. In the case of non-electric kitchen items, approximately 50 to 70 sorts of them are used, which indicates an increase than in 1990s. Rice cookers and gas stoves, among cooking appliances, are recognized as the essential item, and they are actually frequently-used items. As to kitchen appliances related to storing food, each household owns one of the refrigerators and Kimchi fridges, and again they are both the frequently-used. As far as food processing kitchen items are concerned, each household owns at least one or more blenders and hand blenders, six or more knives, and five or more pans. Each household owns seventeen or more rice bowls and soup bowls and twenty-four or more plates. Small plates are more frequently used than large ones.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.846-848
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• 2005

Midnight electrical power appliance has come into a wide use due to the midnight power rate system introduced for effective power operation and an improved load factor. However, the sharply increased number of the appliance has brought about a serious problem in midnight power supply for the past few years. Moreover, the automatic control device, developed to address the problem, has not properly functioned because of the misusage and illegal conversion of the device. This paper will suggest solutions to the problem by improving the automatic control system for supply time (ACST) and demonstrate its effectiveness through tests.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.10
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• pp.35-39
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• 2007

Home appliances, like air-conditionals, washers, refrigerators, etc., can cause voltage fluctuations and light flicker. A standardized flicker test has been established in Europe(IEC 61000-3-3, IEC 61000-3-11). The supply impedance of power supply system varies from plate to place, and for the flicker test in KOREA, the appliance manufacturers do need standardized impedance like the one indicated in IEC 61000-3-3 for 230[V]/50[Hz]. Without it, the same appliance will have different flicker level at different places. For appliance manufacturers, the flicker limit should be related to the reference impedance. However, the European flicker test is designed for 230[V]/50[Hz] power and needs to be modified for a 1P2W(220[V]/60[Hz]) supply system in KOREA. In this paper, the reference impedance for KOREA(220[V]/60[Hz]) systems is proposed. The measured result provided in this paper was served as a proposal for establishing KOREA reference impedance for 220[V]/60[Hz] and has been published in IEC 60725.

• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.51-57
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• 2012

This paper provides a safety guideline for DC supplied home appliances through the comparative analysis of existing safety guideline for AC supplied home appliances. For this purpose, a predictive DC home appliance model is suggested and in special international safety standards of AC appliances are also analyzed. Moreover, a DC distribution system is built to verify the validity of the proposed safety guideline. The detailed analyzing process is explained with help of informative experimental results.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.694-699
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• 2001

The prognosis for class III patients in growing child can be made in mixed dentition and the severity of the symptom is often amenable to early intervention. Class III malocclusion can be classified as functional class lit and skeletal origin. Skeletal Class III malocclusion is usually characterized by overdeveloped mandible, underdeveloped maxilla, but the cause of pseudo class III is most dentoalveolar or functional shift of mandible. The primary goal of early intervention of malocclusion is to supply an environment that is conducive to the development of favorable occlusal relationships and avoiding of worsening of the problems. Inverted labial bow appliance is introduced as an appliance to combine the advantage of active plate and activator. It is undemanding with this appliance to initiate not only dentoalveolar expansion of upper dentition but also to orient the functional retrusion of mandible. With simple design the compliance for patients such as mouth breathing problem can be improved. For successful use of this appliance it is utmost important to make accurate and early diagnosis between pseudo- and skeletal class III malocclusion. This article will demonstrate the use of an Inverted labial bow appliance for early treatment of a functional Class III malocclusion. After 4 month treatment, anterior crossbite was treated and the results were achieved mainly dentoalveolar change of upper and lower anterior teeth.

• Journal of Cadastre & Land InformatiX
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• v.45 no.2
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• pp.71-85
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• 2015

Recently, the South Korean government actively opens the public data to encourage people to use it in private sector. It is based on 'Government 3.0' that is the paradigm for government operation. According to this trend, a data platform is required for establishing and commercializing business models that utilizing geospatial data. However, it is currently insufficient to establish the geospatial data system using the text-based public open data. This study constructs a geospatial data supply system using the public data for the purpose of providing and using the public data of spatial reference type efficiently. It improves the accessibility of user and the usability to the public data having location information. Besides, this study suggests that the components of the appliance system that connects the public data from different public institutions for different purposes with producing the geospatial data in the type of a finished product.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.83-90
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• 2004

Generally, electronic appliances are used on the basis of normal power source supply. The power source inevitably includes the abnormal condition, such as, sudden voltage sagging, power interrupt, and induced noises. As the electronic appliances which include micro-controller-based circuits are being increased recently, the controller circuit sometimes malfunctions by the abnormal condition of the power source. This situation causes serious problems such as hitch of electric appliance, fire and medical instrument glitch, which produces serious situations. In this paper, development of power interrupt tester which is highly suitable for an endurance test device under abnormal power source to microprocessor-based circuits is proposed 89C2051 microcontroller is performed to make power interrupt signal, and software controls peripheral hardwares and built-in functions. Experimental results of this study will offer a good application to electronic appliance maker as a test device of hardware and software debugging use.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.861-863
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• 2003

The method of measurement for laboratory tests on noise emission from appliances and equipment used in water supply installations is specified in ISO 3822-1. This part of standard gives detailed descriptions for mounting and operating draw-off taps and mixing valves in such laboratory test. Draw-off taps and mixing valves are the most common kind of appliance used in water supply installations.

• Journal of the Korean Institute of Gas
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• v.15 no.3
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• pp.26-30
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• 2011

Instantaneous water heater being not properly installed and not adequately maintained may produce fatal accidents due to carbon monoxide poisoning and suffocation. Insufficient supply of air into the gas appliance for complete burning of the fuel or blocking the outlet of the combustion gas could be a cause to increase carbon monoxide concentration in the exhaust gas of the gas appliance. In this work, the experiments are done with a collected instantaneous water heater using in domestic and the concentration of oxygen near the gas appliance and carbon monoxide in exhaust gas are observed to investigate the risk of instantaneous water heater. The concentration of oxygen near the gas appliance is reduced until 17.7% for the ratio of the ventilation area and floor area being 3.5%. If the outlet of combustion gas is blocked, the carbon monoxide concentration is steeply increasing more than 4,000ppm. Therefore, periodic checking the outlet of combustion gas is more important than vent area to reduce the risk of carbon monoxide poisoning.