• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.305-306
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• 2022

본 논문에서는 5G 스마트폰을 활용하여 사용자가 로봇 청소기의 위치 추정을 도울 수 있는 방안을 소개한다. 로봇 청소기는 다양한 알고리즘을 활용하여 자신의 위치를 추정하며, 때로는 오차가 발생하기도 한다. 현재 많은 사람들은 5G 스마트폰을 소유하고 있으며, 이 5G 스마트폰을 활용하여 로봇 청소기의 위치 추정을 보조할 수 있는 방안을 제안한다. 5G 스마트폰은 MIMO 안테나를 사용하여 통신을 하는데, MIMO 안테나는 기존의 전 방향성 안테나와는 달리 방향성을 가지고, 고주파를 사용하기 때문에 신호의 직진성을 보장받는다. 이러한 특성을 활용하여 스마트폰을 참조 노드로 하여 로봇 청소기는 측위를 보조할 수 있다. 본문에서 제안하는 아이디어를 소개하며, Matlab을 활용하여 아이디어의 효용성을 검증하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.5
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• pp.571-577
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• 2012

In this study, a small movable batch treatment system for dredging soil deposited in a rain water tube is proposed; further, a vacuum silo sorting separation device with a vacuum silo, first-stage sorting separator, and conveyor is designed. The vacuum silo sorting separation device also consists of a storage tank, transferring screw, vacuum gate, screen bar, screen bar cleaner, and vacuum discharging device. In view of the fact that the flow of drawn air in the storage tank is a major factor influencing the sorting separation performance, the optimum shape of the tank is determined by CFD flow analysis. In addition, by using CAE structure analysis, the safety of a storage tank made of boards is examined. The specifications of the vacuum silo sorting separation device are determined by conducting mechanical and dynamic simulations of the driving mechanism of the vacuum silo sorting separation device through 3D-CAD modeling. Following this study, we will design a drum-screen-type second sorter, a decanter-type dehydration device, and waste water tank and pump as a secondary device. Further, on the basis of this design, we will construct a prototype model and carry out a field test.

• Clean Technology
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• v.18 no.4
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• pp.440-445
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• 2012

15 carbon footprint product (CFP) schemes, including Korea Carbon Footprint Label, UK Carbon Trust's Carbon Reduction Label and Japan CFP are implemented in the world. A CFP describes green house gases (GHGs) emissions emitted throughout product's life cycle and is intended to reduce GHGs emissions by labeling a CFP result on product. This study calculates Korea, UK and Japan CFP result of vacuum cleaner, detergent, packagin material in order to analyze the Korea, UK and Japan CFP standards. Our results demonstrate significant differences among then calculated results because of criteria, emission factors, etc. Therefore, there are many difficulties in providing various CFP results and the international standard and guidelines for product category are needed.

• Particle and aerosol research
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• v.14 no.2
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• pp.25-33
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• 2018

In this study, the concentration of fine indoor dust and the size distribution of fine indoor dust were analyzed by measuring the dust generated during the cleaning process of an indoor office. We measured $PM_{10}$, $PM_{2.5}$, and $PM_{1.0}$ and analyzed the size distributions of dust larger than $0.3{\mu}m$ in diameter during cleaning. The results showed that the concentration of $PM_{10}$ increased rapidly during cleaning, however $PM_{1.0}$ did not increase. Before cleaning with a broom, the fine dust concentration was about $50{\mu}g/m^3$, but increased to about $400{\mu}g/m^3$ as cleaning progressed. In the case of indoor cleaning with a vacuum cleaner, the concentration of $PM_{10}$ increased during the cleaning process and the increase of $PM_{2.5}$ was relatively small. $PM_{1.0}$ did not increase as in the case of cleaning the broom.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.126-133
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• 2017

This paper deals with the effects of welding, which is done to fix the stator stack, on a motor in case of fabricating a prototype motor that is manufactured in a small quantity. In the case of a small motor, the stator is designed and fabricated with the segmented core as a way to raise the fill factor of winding wire to the utmost within a limited size. In case of fabrication by welding both inside and outside of the stator in order to fix the segmented-core stator, the effects of stack are ignored, and the eddy current loss occurs. This paper performed the no-load test on an IPM-type BLDC motor for driving the suction fan of a vacuum cleaner, which was manufactured by using a segmented-core stator. As a result of the test, it was found that input power more than expected was supplied. To analyze the effects of welding by using the finite element analysis method and verify them experimentally, a stator was re-manufactured by bonding, and input power supplied during the no-load test was compared.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1264-1273
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• 2015

An inverter output power control based power factor correction (PFC) strategy is being extensively used for permanent magnet synchronous motor (PMSM) drives in appliances because such a strategy can considerably reduce the cost and size of the inverter. In this strategy, PFC circuits are removed and large electrolytic DC-link capacitors are replaced with small film capacitors. In this application, the PMSM d-q axes currents are controlled to produce ripples, the frequency of which is twice that of the AC main voltage, to obtain a high power factor at the AC mains. This process indicates that the PMSM operates under periodic magnetic saturation conditions. This paper proposes a back electromotive-force (back-EMF) estimator for the high-speed sensorless control of PMSM operating under periodic magnetic saturation conditions. The transfer function of the back-EMF estimator is analyzed to examine the effect of the periodic magnetic saturation on the accuracy of the estimated rotor position. A simple compensation method for the estimated position errors caused by the periodic magnetic saturation is also proposed in this paper. The effectiveness of the proposed method is experimentally verified with the use of a PMSM drive for a vacuum cleaner centrifugal fan, wherein the maximum operating speed reaches 30,000 rpm.

• Research in Community and Public Health Nursing
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• v.13 no.1
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• pp.79-88
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• 2002

Purpose: The purpose of this study was to identify the indoor environment i.e. house type and age, ventilation method, use of bed & sofa, cockroach, ants, etc. on HDM (House dust mites), especially Der fI allergen. Method: Samples of dust from mattresses, pillows and the floor were collected by using a vacuum cleaner from April. 2000. The amount of Group I allergen(Der. fI) of HDM (house dust mites) were measured by two-site ELISA. Indoor Environmental characteristics were accessed by using questionnaires on 178 house wives living in the Seoul area. Results: The amount of HDM allergen (Der fI) was higher in sofa using house. There were higher concentrations of HDM allergen (Der fI) in sofas made from quilt material than for those that were made from leather. Homes that had pets like dogs living in them had higher concentrations of HDM allergen (Der fI) than without dogs. Conclusion: The photophobic mites thrive in dark. warm and humid environments; Items such as pillows. mattresses, box springs, blankets. carpets. and upholstered furniture should be considered ideal environments for the mite. Therefore, an indoor environmental control program should be carried out to avoid the HDM allergen.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.332-339
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• 2007

As the economy has grown and the main industry in Korea has been changed from secondary industry to tertiary industry, the importance of indoor environment has been a matter of common concern, in which one of the main concerns is to improve the indoor acoustic conditions. However, even though this is required more than before, there are no measures to protect the human being from the noise of electric home appliances. This is owing to the absence of the data about sound power level of electric home appliances. So, we investigate the sound power level of them and analyze the acoustical characteristics of each one. First, we tried to investigate the sound power measurement method of each electric home appliance. After it we test the sound power level of them. From the survey, we can know that the vacuum cleaner is the most noisy electric home appliance, and the refrigerator is the least noisy one. The noise of a range hood is distributed over a wide range frequency. Lastly, we intented to propose the proper method measuring sound power level on each electric home appliance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.73-79
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• 1994

(1) 진공청소기의 소음은 팬모타의 회전에 기인하는 유체소음과 진동소음이 주류를 이루며, 여기에 공기의 흡입과 배출에 따른 유체소음등이 복합되어 나타난다. (2) 진공청소기의 소음특성은 각 소음원들의 특성에 따라 주파수대역을 구분할 수 있으며, 기계적 진동음인 500Hz부근에서 peak를 보인다. (3) 소음의 저감을 위하여는 기존에 정립되어 있는 흡음, 차음, 감쇠, 방진, 유압유속감소 등의 기술을 종합적으로 활용하여 제한된 공간내에서 효과를 극대화할 수 있는 구조개발이 필요하며 본 연구에 적용하였다. (4) 본 연구의 '정음유로구조'는 차음효과, 유로길이 증가에 의한 감쇠효과, 흡음효과를 극대화할 수 있는 구조이다. (5) 팬모타의 진동모드는 회전축을 중심으로 원운동을 하며, 진동량은 흡입구와 뒷쪽 베어링부위가 가장 작으므로 회전축에 가까운 곳을 지지하는 것이 방진에 유리하다. (6) 본 구조에서 사용된 케이싱은 484Hz의 고유진동수 성분을 가지며 이는 모타와 공진할 우려가 있다. 이에 공진주파수 성분의 진동량이 가장 작은 전면과 후면의 중앙부를 지지하여 진동을 줄일 수 있었다. (7) 본체소음의 전반적인 저감에 따라 흡입구 등에서 발생하는 공기마찰소음의 영향이 상대적으로 커지며, 따라서 흡입구의 유선형 설계 및 누설소음의 흡음, 차폐 등의 역할이 중요한 관리 요소로 된다.

• Korean Institute of Interior Design Journal
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• v.21 no.2
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• pp.231-242
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• 2012

The purposes of this study were to identify the needs for ubiquitous home services in residential environment of elderly single or elderly couple households living without children and also to analyze the differences of the needs according to their demographic and housing characteristics. For this study, a literature review and field works on ubiquitous home services for older people were performed. Also, 1 to 1 interview by using the questionnaire which was developed by the researchers in this study was conducted and 270 elderly residents in Seoul and Gyeonggi-Do were responded. Seventy-one ubiquitous service items which were adopted to home electronic appliances and furniture for older people were developed for 1 to 1 interview questionnaire. The major findings of the study were as follows: the elderly residents expressed highest need for ubiquitous home service items related to safety and health issues. Among ubiquitous service items applied to gas stove, vacuum cleaner, TV, telephone, sofa and toilet, the items related to safety and health aspects were most needed. And residents' income level and health status were the two major variables to show group differences in the need of ubiquitous home services. In other words, the elderly residents who were high income and frail tended to have the highest demand for ubiquitous home services adopted to home electronic appliances and furniture.