• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.11
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• pp.616-621
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• 2002

With biological effects by ELF (Extremely Low Frequency) magnetic field generated from power system, the transient magnetic field from electric appliances is a major issue presently. Because the transient magnetic field induces higher current than the power frequency field inside living bodies, transient magnetic field exposure has been much focused. In this paper, it is shown that transient magnetic field from electric home appliances can be characterized as magnetic dipole moment. In this method, the dipole moment vector is assumed by allowing an uncertainty of 6dB in the estimated field. A parameter M that represents biological interaction was applied also. The proposed method was applied to 7 types of appliances (hair drier, heater, VDT, etc.) and their equivalent magnetic dipole moment and harmonic components were estimated. As the results, the useful data for quantifying magnetic field distribution around electric appliances were obtained.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.537-540
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• 2001

As giving IP on electric home appliance like as TV, Air-conditioner, etc., with the development of electric products and home networking, it has been possible to communicate through the Internet. In this paper, we proposed and developed the system which is possible to control the commercial vending machine using embeded internet card through internet. We implemented the basic circuit and application program for TCP/IP communication program by Java applet.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.36-38
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• 2005

In home appliances, electric energy is optimally controlled by using power electronics technology, creating a comfortable environment in terms of energy saving, low sound generation, and reduced time consumption. Usually simplicity and robustness make the three phase induction motor attractive for use in domestic appliance, including washing machines. Two main types of domestic washing machine have evolved. We focus on the front loading machine favored in Europe, which has a horizontal drum axis. The efficiency improvement in home appliances is very important for customers. Induction motor efficiency can be improved by means of loss reduction, which can be realized by motor selection and design, improvement of the waveforms supplied by power Inverter, utilizing a suitable control method. So this paper describes the architecture and feature of washing machine fed induction motor drive under minimizing losses vector control.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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• pp.1470-1477
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• 2008

In this paper, a new detection method of series arc-fault signals occurring at the wiring of home appliances is proposed. The discrete wavelet transform was used for the numerical analysis of the variation rate in peak, RMS, noise energy, shoulder of the arc-fault current wave. As a results, the arc distinction threshold value of these variation rates was about 0.1 in most cases. The arc-fault current of the loads with the active PFC circuit showed a high rate of variation in noise energy and shoulder, but arc-fault current of the loads without the active PFC circuit showed a high rate of variation in peak and RMS. The arc fault current in resistive loads showed a high rate of variation in shoulder.

• KIISE Transactions on Computing Practices
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• v.21 no.8
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• pp.555-560
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• 2015

In this paper, we analyzed the existing control methods of the legacy wearable-based CE devices and identified the requirements for improvements. In the conventional system, users waste their time configuring the initial network and registering their devices with the management server. To overcome these hurdles, we implemented the Easy-Setup framework for smart phones to personalized cloud devices.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.7
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• pp.743-748
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• 2011

The performance of HFO-1234yf as a substitute for R-134a was evaluated in a household freezer/refrigerator. A series of tests such as 'refrigerant charging test, pull-down test, cooling speed test, and energy consumption test were carried out under the AHAM (Association of Home Appliance Manufacturers) standard. The results of a drop-in test were compared with those of a test conducted using R-134a. A test under a severe ambient air condition ($43^{\circ}C$) was also conducted. The result shows that the refrigeration cycle performance of HFO-1234yf is as good as that of R-134a ; however, the diameter of capillary tube should be increased in order to improve its performance in the cooling speed test.

• Journal of Oral Medicine and Pain
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• v.41 no.1
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• pp.7-15
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• 2016

Purpose: Mandibular advancement device (MAD) is widely recognized as an important treatment option for obstructive sleep apnea (OSA) and is readily accepted than any other treatment options owing to its simplicity and ambulatory nature. At this time, there are a multitude of MAD designs and their efficacies may be influenced by adjustment and retention mechanism. The MAD with the anterior connector (anteriorly adjustable mandibular advancement device, AAMAD) was newly developed in the Department of Oral Medicine, Dankook University Dental Hospital (Cheonan, Korea) and was prescribed for the OSA patients including snoring patients. Thus, this study was aimed to objectively investigate the effectiveness of the AAMAD on the OSA patients using the self-applied portable device (ApneaLink), and evaluate the treatment outcomes among patients with various severity of OSA level. Methods: Results of the treatment of fourteen patients (13 male, 1 female) with the AAMAD were retrospectively analyzed. Each patient underwent home sleep test before treatment and were divided into two groups, i.e., those with mild (apnea-hypopnea index [AHI] ${\geq}5$ and <15) to moderate OSA (AHI ${\geq}15$ and <30) and severe OSA (AHI ${\geq}30$). After treatment, home sleep test was conducted again and treatment outcomes were compared between mild to moderate and severe OSA patients. Results: Of all patients, 78.6% showed more than 50% AHI reduction. We found a significant reduction (85.3%) of AHI in the severe OSA patients. Patients with mild to moderate OSA showed the reduced AHI (56.1%). Conclusions: We concluded that AAMAD is an effective oral appliance for the majority of OSA patients.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2589-2594
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• 2009

Aging phenomena of plasma polymer films were studied by using the surface analysis techniques of contact angle measurement, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOFSIMS), and atomic force microscopy (AFM). The polymer films were grown on an aluminum substrate by using a plasma polymerization method from a gas mixture of acetylene and helium, and the films were subsequently modified to have a hydrophilic surface by oxygen plasma treatment. Aging of the polymer films was examined by exposing the samples to water and air environments. The aging process increased the hydrophobicity of the surface, as revealed by an increase in the advancing contact angle of water. XPS analysis showed that the population of oxygen-containing polar groups increased due to the uptake of oxygen during the aging, whereas TOF-SIMS analysis revealed a decrease in the polar group population in the uppermost surface layer. The results suggest that the change in surface property from hydrophilic to hydrophobic nature results from the restructuring of polymer chains near the surface, rather than compositional change of the surface. Oxidative degradation may enhance the mobility and the restructuring process of polymer chains.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.114-120
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• 2021

Furniture is an essential element in the area of human residence, and the necessity of system furniture suitable for the pursuit of unity in design, which clearly distinguishes the various and flexible arrangements and characteristics of space, is gradually expanding. The elderly population in Korea currently exceeds 15%, and is expected to be close to 40% by 2050. An increasing number of elderly generations are showing different behavioral patterns, such as sharing information, health care, and seeking independence from children. In order to maintain an independent daily life, a stable living environment has become essential, but as a result of a study that safety accidents caused by households increase due to a decrease in cognitive ability and physical ability, the need for a suitable household has increased. Therefore, the biological changes and characteristics of the elderly were investigated, and the concept definition, scope and limitations of system households were studied. In addition, by grasping the changes in the home appliance market and trends in the home appliance market, the design direction of system furniture required by the elderly was presented.

• Journal of Korean Institute of Industrial Engineers
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• v.38 no.3
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• pp.182-190
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• 2012

With the progress of both wire and wireless home networking technology, various projects on smart home have been carried out in the world (Harper, 2003), and at the same time, new approaches to interact with smart home systems efficiently and effectively have also been investigated. A gesture-based interface is one of these approaches. Especially with advance of gesture recognition technologies, a variety of research studies on gesture interactions with the functions of IT devices have been conducted. However, there are few research studies which suggested and investigated the use of gestures for controlling smart home appliances. In this research the gestures for selected smart home appliances are suggested based on a user centered approach. A total of thirty-eight functions were selected, and a total of thirty participants generated gestures for each function. Based on the Nielsen (2004), Lee et al. (2010) and Kuhnel et al. (2011), the gesture with the highest frequency for each function (Top gesture) has been suggested and investigated.