• 한국대기환경학회지
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• 제31권6호
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• pp.520-529
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• 2015

The ambient $PM_{2.5}$ samples were collected by $PM_{2.5}$ sampler from September 2010 to December 2012 at Daegu University, Gyeongsan. A total of 260 samples were collected and 27 species were analyzed by inductively coupled plasma, ion chromatography, and thermal optical reflectance methods. Factor analysis identified four sources such as biomass burning source/secondary aerosol source, soil source, industry source, and incinerator source/mobile source. Also, backward trajectories were calculated using HYSPLIT 4 (Hybrid single-particle lagrangian integrated trajectory) model and PSCF (Potential source contribution function) model was applied to identify the possible source locations of carbonaceous species and water soluble ions species. PSCF results showed that the possible source locations of most chemical constituents measured in Gyeongsan were the industrial areas in the eastern coast of China, northeast regions of China, the Gobi Desert, and east sea of Korea.

• 한국의상디자인학회지
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• 제9권1호
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• pp.221-234
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• 2007

The purposes of this study were to identify the effect of clothing involvement and shopping orientations on the usage of information sources and to investigate the differences of clothing involvement, shopping orientation and clothing purchasing behavior according to the types of information source usage. The study subjects comprised 302 females living in Seoul. The datas were analyzed with factor analysis, regression, ANOVA, discriminant analysis, and $x^2$-test. The results generated from this study are as follows: First, clothing involvement and shopping orientation factors influenced the usage of information source. Among the clothing involvement factors, fashion/clothing involvement was the most important factor to the types of information source. Second, according to usage of information sources, female consumers were classified into four groups, such as active, nonpersonal, personal, and non-active information source usage group. Fashion/clothing involvement was the most significant involvement factor to divide four groups. Third, among the demographic variables, only age was the useful factor which can differ the usage of information source. For example, 30s' were more active than other groups, on the other hand 50s' use personal information source more than other groups. Therefore, marketer should blow consumer's clothing involvement and shopping orientation which are effective to the usage of information source, and use this knowledge on the advertising and marketing plan.

• 한국소음진동공학회논문집
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• 제19권1호
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• pp.42-49
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• 2009

In this paper, an alternative method was introduced to conduct a transfer path analysis for airborne noise. The method used the transfer function matrix composed of acoustic transfer functions that are referenced by the input voltage of a calibration source. A calibration factor which is converting a virtual voltage to source strength was deduced by vibro-acoustical reciprocity theorem. The calibration factor is then multiplied to the virtual input voltage to estimate the operational source strength. Three loudspeakers were used to noise sources of acrylic half car model. The method was applied to airborne noise transfer path analysis of the half car. The estimated source strength by transfer path analysis was compared the deduced source strength by vibro-acoustical reciprocity to verify the method.

• 전기학회논문지
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• 제58권2호
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• pp.369-372
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• 2009

When measuring the luminous flux of a light source at the integrating sphere photometer, it can know the luminous flux to compare the standard lamp with the specimen lamp at the same location. But in case of PLS(plasma lighting system, microwave discharged lamp), that two lamps are cannot be the same location. If the reference illuminant and specimen lamp are cannot measure identical location, we should measure the variation of the luminous flux. For the outcome we can turn out a correction factor to revise and reflect it. But the better way is calibrate the specimen lamp locate the identical location of reference illuminant measured. In this thesis, we've test to find the correction factor for consider that change the measuring location. And it turns out the correction factor. From this, it presents the result to make a select for the reference illuminant which is against the illuminant type for newly produce.

• 한국환경과학회지
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• 제10권3호
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• pp.209-216
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• 2001

Dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 6 sampling sites in Pusan area from March, 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP. The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal distribution. Dustfall amount of regional variations were found in order of coastal zone, industrial zone, commercial zone, agricultural zone and residential zone, and seasonal total dustfall had higher concentrations during spring for 6.741 ton/${km}^2$/season, lower concentrations during summer for 1.989 ton/${km}^2$/season, and annual total concentration was 17.742 ton/${km}^2$/year. The regional distributions of enrichment factor show well-defined anthropogenic metals (Cd, Cu, Pb, and Zn) at industrial and agricultural zone, and contribution rate of soil particles were found in order of summer, fall, winter and spring. Factor loading effects of chemical composition of dustfall were found in order of road traffic emission source and combustion processed source, industrial activity source, soil source and marine source.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2478-2480
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• 1999

In this paper, the authors propose a current control system for three phase PWM AC/DC converter without the source voltage sensors. The sinusoidal input current and unity effective power factor are realised based on the estimated source voltage in the controller. The estimation of source voltage is performed based on Luenberger observer using actual currents. The estimated source voltage is used to accomplish unity power factor. The proposed method is proved by simulations.

• 전기학회논문지
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• 제67권12호
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• pp.1602-1610
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• 2018

Induction heating can convert electrical energy to thermal energy with high conversion efficiency and quick heating. Currently, a current source rectifier/inverter-fed parallel resonant circuit is widely used as an induction heating power supply for forging applications. However, the conventional induction heating power supplies composed of phase-controlled rectifier and SCR inverter have low efficiency and low power factor at input side, and require additional starting circuitry. So this paper proposes new induction heating power supply topologies for forging applications which have high power factor, high efficiency, and large output power. It also suggests detailed design guideline.

• 한국문헌정보학회지
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• 제31권1호
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• pp.29-52
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• 1997

본 연구는 국내 의학 연구자들의 SCI 이용 실태와 SCI 학술지에 대한 인지도를 규명하기 위하여, 국내 4개의 유수한 의과대학에 재지 중인 교수 902명 중 무작위 추출한 180명 $(20\%)$을 대상으로 설문지 조사를 시행하여 104명 (회신율$57.8\%$)의 설문응답 내용을 분석하였다. 국내 의학자들은 필요한 의학 정보를 찾을 때 SCI는 별로 이용하지 않는다. 대신에 대부분의 국내 의학 도서관이 소장하고 있어 그 이용이 편리한 MEDLINE을 집중적으로 사용하고 있다. 또한. 국내의 많은 의학자들이 SCI 학술지의 Impact factor list를 Journal Citation Reports (JCR)로. JCR을 색인지인 SCI로 혼동 또는 동일시하고 있었다. 즉 국내에서 SCI에 대한 지식과 용도는 색인의 기능이라기 보다는 Impact factor 정보원의 기능이다. Impact factor에 대한 관심은 SCI 학술지에 논문을 투고해야 한다는 목적의식과 밀접하게 연계되어 있을 뿐이다. 본 연구의 대상이 되었던 의과대학들은 국내 타 의과대학보다 좋은 연구여건을 갖추었을 터인데도. 소속 교수들이 SCI. SCI 학술지 그리고 Impact factor에 대하여 정보 부족 및 부재 현상을 겪고 있다. 그럼에도 불구하고. 이들의 각 분야별 국내외 주요 학술지에 대한 주관적인 인지도는 인용문헌 분석에 의하여 선정된 SCI 학술지의 범위. Impact factor 순위와 상당 부분 일치하고 있다. 그러므로 국내 의학 교수들에게 SCI 학술지에 논문을 발표하도록 독려하는 방안이나, SCI 학술지에 논문 게재 여부로 연구 업적을 평가하는 정책은 긍정적으로 검토되어 질 수 있겠다.

• 한국산업보건학회지
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• 제10권1호
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• pp.160-169
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• 2000

Daily indoor and outdoor nitrogen dioxide ($NO_2$) concentration for 30 days were measured in 28 houses with questionnaire of housing characteristics in Brisbane, Australia. Using mass balance equation and regression analysis, penetration factors and source strength factors were calculated. The penetration factors of 27 houses except one house were between zero and 1, though penetration factor should be between zero and 1 by means of mass balance equation. Relationship between indoor and outdoor concentrations in each 27 house was calculated using regression analysis. According to the obtained linear regression equation, the slope means penetration factor and the intercept means source strength factor. Calculated mean and standard deviation of coefficients of determination ($R^2$) in electric and gas range houses were $0.70{\pm}0.13$ and $0.57{\pm}0.21$, respectively. The source strength factors were more than zero in 27 houses. Mean and standard deviation of slopes in electric and gas range houses were $0.65{\pm}0.18$ and $0.56{\pm}0.12$, respectively. Mean and standard deviation of intercepts in electric and gas range houses were $1.49{\pm}1.25$ and $5.77{\pm}3.55$, respectively. Air exchange rate and source strength were calculated from penetration factor and source strength factor, respectively. Geometric mean and standard deviation of calculated air exchange rates in 27 houses were $1.1/hr{\pm}1.5$. Presence of gas range was the most significant factor contributing to indoor $NO_2$ level in house characteristics (p=0.003). In gas range houses, source strengths ranged from 4.1 to $33.1cm^3/hr{\cdot}m^3$ with a mean $12.7cm^3/hr{\cdot}m^3$ and a standard deviation 9.8. The source strengths of gas range houses were significantly different from those of electric range houses by t-test (p<0.001)

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.57-61
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• 2006

In the single-phase switched reluctance motor (SRM) drive, the required DC source is generally supplied by the circuit consisting of bridge rectifier and large filter capacitor connected with DC line terminal. Due to the large capacity of the capacitor, the charged time of capacitor is very short from the AC source. Lead to the bridge rectifiers draws pulsating current from the AC source side, which results in reduction of power factor and low system efficiency. Therefore a novel single-phase SRM drive system is presented in this paper, which includes drive circuit realizing reduction of torque ripple and improvement of power factor with a novel switching topology. The proposed drive circuit consists of one switching part and diode, which can separate the output of AC/DC rectifier from the large capacitor and supply power to SRM alternately, in order to realize the torque ripple reduction and power factor improvement through the switching scheme. In addition, the validity of the proposed method is tested by some simulations and experiments.