• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.74-81
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• 2020

As of 2020, due to the influence of fine dust from China and domestic dust, the cloudy sky of Korea has become a daily routine not only in spring but also in autumn/winter. In 2013, the International Cancer Institute under the World Health Organization designated fine dust as a group 1 carcinogen that has been confirmed to be carcinogenic to humans. The purpose of this study is to theoretically review 5 fine dust-related design studies, by analyzing the case of three types of wearable air purifiers on the market, it is to propose an improved open wearable air purifier. As a verification method, a working prototype was produced to measure the amount of fine dust reduction. Therefore, this study derived three design insights of wearable air cleaner through case analysis. First, it maximizes openness by minimizing the area touching the face. Second, the nozzle where the air comes out should be close to the respiratory organ. Third, position of the motor is to be as far away as possible from the ear considering the noise. Based on this, I suggested an open-type wearable air purifier design that maximizes the user openness and improves the wearing comfort. I hope that it will be an opportunity to increase the coverage of wearable air cleaner and protect the respiratory health of users.

• Environmental and Resource Economics Review
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• v.13 no.1
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• pp.133-160
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• 2004

This paper analyzes the long-run effects of an environmental tax levied on motor vehicles. If the government charges their consumers the tax as much as the monetary value of the external damage due to the pollutants emitted from motor vehicles, the operation of vehicles is reduced to the socially optimal level, alike to ordinary Pigouvian taxes. Thus, air pollution abatement is realized in the short run. Moreover, in the long run, the tax leads the consumers to prefer cleaner vehicles owing to the tax burden, and so the firms produce the motor vehicles with less pollutants emitted to meet the change of demand. Therefore, the tax has the additional effect on air pollution abatement. This result is obtained from the simulation in the oligopoly model which has an interior solution when the vehicles are horizontally and vertically differentiated.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.533-534
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• 2016

본 논문은 차량용 Built-in 청소기용 SRM(Switched Reluctance Motor) 드라이브 시스템 개발에 대하여 설명한다. 기존의 청소기용 모터는 대부분 영구자석을 사용하는 PMSM 또는 BLDCM이다. 그러나 영구자석의 주 원료인 희토류 광물가격의 상승으로 인해 영구자석형 모터를 대체할 비 희토류 모터(SRM)에 대한 관심이 커지고 있다. 본 논문에서는 제작된 차량용 Built-in 청소기용 SRM의 유한요소해석 데이터를 바탕으로 한 Matlab/Simulink 시뮬레이션 및 실제 실험을 통하여 가능성을 검증하였다.

• International Journal of Automotive Technology
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• v.1 no.1
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• pp.9-16
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• 2000

The growing concerns on environmental protection have been constantly demanding cleaner and more energy efficient vehicles without compromising any conveniences provided by the conventional vehicles. The recent significant advances in proton-exchange-membrane (PEM) fuel cell technology have shown the possibility of developing such vehicles powered by fuel cells. Several prototype fuel cell electric vehicles (FCEV) have been already developed by several major automotive manufactures, and all of the favorable features have been demonstrated in the public roads. FCEV is essentially a zero emission vehicle and allows to overcome the range limitation of the current battery electric vehicles. Being motivated by the laboratory and field demonstrations of the fuel cell technologies, variety of fuel cell alliances between fuel cell developers, automotive manufactures, petroleum companies and government agencies have been formed to expedite the realization of commercially viable FCEV. However, there still remain major issues that need to be overcome before it can be fully accepted by consumers. This paper describes the current fuel cell vehicle development status and the staggering challenges for the successful introduction of consumer acceptable FCEVS.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.795-796
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• 2006

본 논문은 청소기용 BLDC 전동기 모터에 기존의 전기강관이 아닌 SMC(Soft Magnetic Composite)를 적용하여 진공청소기용 BLDC 전동기 모터 설계를 하는데 있다. 본 논문에서 사용한 SMC는 순철 분말에 전기적 절연 코팅을 실시한 새로운 재질로 현재 많은 연구가 진행 되고 있는 분야이다. 그러나 재질의 특성에 적합한 모터 설계에 관한 연구는 미진 하였다. 따라서 본 연구는 진공청소기용으로 많이 사용되는 BLDC 모터에 SMC를 적용 하였을 때 BLDC 전동기의 특성을 알아 보고자 하였다. 본 연구에서 SMC재질을 사용 할 때는 어느 조건에서 사용함이 유리한지 알 수 있었다. 또한 고속 청소기에 적합한 설계를 실시한 결과 SMC 재질의 낮은 투자율로 말미암아 인덕턴스가 감소하고, 전류가 높아져, 출력 증대 되는 것으로 나타 났다. 향 후 본 연구는 SMC를 이용한 BLDC 모터 설계 시 설계 기준으로 이용 될 수 있을 것으로 사료된다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.2
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• pp.206-215
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• 1994

A method for simulating general characteristics and temperature characteristics of discharging SCR of the capacitor discharge impulse magnetizer-magnetizing fixture system using SPICE is presented. This method has been developed which can aid the design, understanding and inexpensive, time-saving of magnetizing circuit. As the detailed characteristic of magnetizing circuit can be obtained, the efficient design of the magntizing circuit which produce desired magnet will be possible using our SPICE modeling. Especially, computation of the temperature rise of discharging SCR is very important since it gives some indication of thermal characteristic of discharging circuit. It is implemented on a 486 personal computer, and the modeling results are checked against experimental measures. The experimental results have been achived using 305[V] and 607[V] charging voltage, low-energy capacitor discharge impulse magnetizer-magnetizing fixture of air cleaner DC motor.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.833-836
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• 1995

A capacitor discharge impulse magnetizer is used to produce a high current pulse of short duration in a magnetizing fixture for magnets of the various shapes. The problem of designing custom fixtures for magnetization has often been considered more of conventional experience than a scientific theory. Therefore, the design of magnetizingfixture has until recently been a "cut and try" process. It was common to literally blow up one or more fixtures beforeachieving the desired results. Finite element CAD package allow the design of such a fixture. Since magnetizing fixtures come in a variety of sizes and shapes, there is usually no simple analysis method that can be used to estimate the field characteristics of the fixtures. Instead, one typically uses finite element analysis. FEA program MAXWELL is the primary tool used here. The purpose of this study was a examine both theoretically and experimentally the field characteristics inside the fixture. Independent of sizes and shapes of magnetizing fixtures, the desired magnetic field can be obtained with resonable predictability. The experimental results have been achieved using a 1000[V], 22.4[KJ] capacitor discharge magnetizer and iron-core fixtures.

• Journal of Animal Environmental Science
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• v.12 no.3
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• pp.133-140
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• 2006

The climate of stall significantly influences on animal production ability. High concentration of ammonia gas, $CO_2$ and lots of dust are found in modern densely raising stall system, as results, they provide a negative influence on animal and farmer health, and production ability. Therefore, it is necessary to keep clean the inside air of stall to increase the productivity. An air cleaner of wet type, consisting of a fan, a motor, rotating discs, a dust collector, a water bowl, an ozone generator etc, has been developed to clean the stall air. The work principle is that the inside air is sucked through the fan, and the rotating discs make water into fineness spray and blow into the stall. The rest water flows down to the dust collector. In the present study, we measured the dust, ammonia gas, odor, temperature and humidity in a swine stall that were installed two wet air cleaners with 700 fattening swine with On-mode and Off-mode of wet air cleaners. The dust measure was divided into 3 categories, TSP, $PM_{10}$, and $PM_{2.5}$. In summer, the TSP in on-mode were maximum $0.259mg/m^3$ and minimum $0.128mg/m^3$, and the average was $0.195mg/m^3$. These are comparable to the data from Off-mode stall that maximum $0.308mg/m^3$, minimum $0.139mg/m^3$, and average $0.277mg/m^3$. However, $PM_{10}$ and $PM_{2.5}$ showed any significant differences between the tests. The concentrations of ammonia gas in Off-mode stall were maximum 13.8 ppm and minimum 5.9 ppm, and the average was 8.47 ppm. However in On-mode stall the ammonia gas concentrations were maximum 10.5 ppm and minimum 5.5 ppm, and the average was 7.63 ppm. The concentration of ammonia gas in On-mode was 10% in average lower than off-mode stall. Odor was measured by olfactometer. In the Off-mode stall, the odor unit were maximum 420 $Ou/m^3$ and minimum $300\;OU/m^3$, and the average was $367\;OU/m^3$, but in the On-mode stall the odor unit were maximum $330\;OU/m^3$ and minimum $210\;OU/m^3$, and the average was $253\;OU/m^3$. Odor removal efficiency was about 31% in On-mode stall.

• 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.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.3
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• pp.381-387
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• 1994

In this paper, we found the improved SPICE heat transfer modeling of impulsed magnetizing fixture system and investigated temperature characteristics using the proposed model. As the detailed thermal characteristics of magnetizing fixture can be obtained, the efficient design of the impulsed magnetizing fixture which produce desired magnet will be possible using our heat transfer modeling. The knowledge of the temperature of the magnetizing fixture is very important of forecast the characteristics of the magnetizing fixture which produce desired magnet will be possible using our heat transfer modeling. The knowledge of the temperature of the magnetizing fixture is very important to forecast the characteristics of the magnetizing circuits under different conditions. The capacitor voltage was not raised above 810[V] to protect the magnetizing fixture from excessive heating. The purpose of this work is to compute the temperature increasing for different magnetizing conditions. The method uses multi-lumped model with equivalent thermal resistance and thermal capacitance. The reliable results are obtained by using iron core fixture (stator magnet of air cleaner DC motor) coupled to a low-voltage magnetizer(charging voltage : 1000[V], capacitor : 3825[$\mu$F]. The modeling and experimental results are in close aggrement.