• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.231-232
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• 2016

This paper investigates the design of multi-winding coupled inductor for minimum inductor current ripple. Based on the general circuit model of coupled inductor together with the operating principles of dc-dc converter, the relationship between the ripple size of inductor current and the coupling factor is derived under the different duty ratio. The optimal coupling factor of n-phase multi-winding coupled inductor which corresponds to a minimum inductor ripple current becomes -(1/n-1), i.e. a complete inverse coupling without leakage inductance, as the duty ratio of steady-state operating point approaches 1/n, 2/n, ${\cdots}$ or (n-1)/n. In an opposite manner, the optimal coupling factor value of zero, i.e. zero mutual inductance, is required when the duty ratio of steady-state operating point approaches either zero or one. Therefore, coupled inductors having optimal coupling factor can minimize the ripple current of inductor and inductor size.

• 대한방사선치료학회지
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• 제11권1호
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• pp.28-32
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• 1999

Verifying the treatment value(Monitor Unit) unnecessarily involves too many simple and repetitive calculation processes, that is, individual computation process using the data(PDD value, Scp Factor, SSD Factor, Tray Factor) on the data book. We intend to minimize the time required to check the Monitor Unit through computerized calculation. Using $^{\ast}(multiplication)$, /(division), +(sum), if function, among others, which are present in the Excell program, MS office program, the Monitor Unit was obtainable through A/P value, Scp Factor and PDD value, Wedge Factor. From the verification of the computations of Monitor Unit for 60 patients previously treated, we were able to obtain an error rate of ${\pm}0.028MU$. Computerized calculation of the Monitor Unit could save the burden of Technologist.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.746-749
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• 2002

This paper presents a new control method for the high frequency electronic ballast which is operated with raw rectified dc link using diode bridge. For the commercial electronic ballast, proper ac input power factor and crest factor of the lamp current are required. The most ballast, therefore, has a active or passive power factor collection (PFC) circuit. With the proposed method, it can be achieved simultaneously that grater than 0.9 of input power factor and less than 1.85 of lamp current crest factor without any PFC circuit. In this paper, the proposed ballast control scheme and the experimental results for the application to the fluorescent lamp are described.

• 전기학회논문지P
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• 제63권4호
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• pp.236-240
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• 2014

Induction motor requires a rotating magnetic for rotation. Current required to generate the rotating magnetic field is magnetizing current. This magnetizing current is associated with the reactive power. This reactive power must be supplied from source side. Therefore, the power factor of the induction motor is low. So, the capacitor is installed on the motor terminals to compensate for the low power factor. Power supply company has recommended to maintain a high power factor to the customer. If the capacitor current is greater than the magnetizing current of the motor, there is a possibility that the self-excitation occurs. So it is necessary to calculate the optimal capacity capacitor current does not exceed the magnetizing current. In this study, we first compute the no-load current and the reactive power of the induction motor and then calculates the limit of the maximum power factor without causing self-excitation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.373-377
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• 1996

Recently, active power factor control for AC/DC converter has been required to replace for a conventional diode rectifier. A voltage type AC/DC converter is widely used to obtain higher regulated DC voltage than input voltage with a unity power factor and a sinusoidal line current. This paper describes several active power factor control method for AC/DC converter. The analysis of several active power factor control is given. The simulations for hysteresis control, peak current control. constant frequency control and average current mode control are represented and compared.

• 산업경영시스템학회지
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• 제46권1호
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• pp.42-47
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• 2023

With rapid urbanization, the importance of urban warfare is increasing, and it is also required to reflect the characteristics of cities in wargame models. However, in the military's wargame models, the urbanization factor was calculated and used without theoretical basis. In this study, we investigate techniques for estimating the urbanization factor using Fractal dimension theory. The urbanization factor we propose can suggest a logical and valid representative value when used in conjunction with Agent Based Model and other methodologies.

• 한국산학기술학회논문지
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• 제8권3호
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• pp.654-659
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• 2007

본 논문은 호텔기업이 많이 활용하고 있는 CRM의 운용성과를 측정하기 위한 측정 요인에 대한 연구를 하였다. 이를 위해 통계적인 방법인 요인분석(Factor Analysis)과 AHP(Analytic Hierarchy Process)분석 기법을 연계하여 분석하는 방법을 연구하였다. 요인분석은 서로 상관있는 변수들만을 그룹화하고, 상관도가 낮은 변수는 또 다른 그룹으로 묶는 결과를 도출한다. 그러나 요인분석은 요인의 분류 외에는 주요 정보를 제공하지 못한다. 그렇기 때문에 이를 극복하기 위해서 분산분석, 회귀분석 등 다른 통계분석 방법을 시도한다. 그러나 이러한 분석은 요인분석 결과와 연계되는 것이 아니라 독립적인 분석을 하게 되는 것이다. 그렇지만 호텔기업의 CRM 운용성과 분석에서는 요인의 중요도 분석이 중요하다. 따라서 AHP 분석기법을 연계하여 호텔기업의 CRM 운용 성과를 측정하기 위한 요인 분석방법에 대해 고찰하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.802-807
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• 1998

The main drawback of parallel type active power filters (APF) is the large capacity required for harmonic compensation. This paper evaluates the APF capacity requirement of harmonic/reactive power compensation for thyristor converter load. Theoretically achievable maximum power factor under partial load is evaluated. And it is shown that the APF capacity can be considerably reduced while slightly sacrificing the filtering performance by deliberately limiting the peak current of the APF.

• 한국의상디자인학회지
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• 제15권4호
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• pp.29-45
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• 2013

The purpose of this study is to provide base line data required to establish a viable knitwear marketing strategy targeting young people by comparing and analyzing preference and buying behavior of customers in their twenties. A survey was conducted in 2009 and 2013 on people in their 20's male and female living in Busan. The total of 362 people participated in the survey and the results are as follows: Firstly, the seeking factors for knitwear were utilization factor, functionality factor, care for clothing factor, economics factor and vogue factor. Secondly, a differentiated marketing strategy targeting 20-something customers needs to be established as there was a steep rise in the number of customers purchasing clothes on online shopping malls using smart phone devices according to the survey.'Low-price, broad-line strategy'is also required as those surveyed preferred stores offering a wide choice of designs with reasonable price. Considering the survey results that a growing number of people tended to buy a variety of knitwear items regardless of the seasons, knitwear production needs to be diversified in terms of designs and materials. Thirdly, the survey revealed that pastel-colored knitwear was preferred for spring/summer season whereas knitwear with achromatic colors was voted the most-preferred one during the autumn and winter season. In terms of knitwear shapes, the gap between genders continues to narrow and tendency sensitive to fashion trend became more apparent reflecting the change of the times.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.892-897
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• 2005

Macrophage colony-stimulating factor (M-CSF) is a growth factor required for growth and differentiation of mononuclear phagocyte lineage. Total and 16 poly (A) mRNA of bovine M-CSF were isolated from healthy bovine peripheral mononuclear cells stimulated by phobol 12-myristste 13-acetate (TPA). The more compatible cultured mononuclear cells were 5${\times}$10/ml for RNA isolation. TPA-activated mononuclear cells increased the level of M-CSF-mRNA more than concanavalin A (Con A) and lipopolysaccharide (LPS). The optimal analysis of reverse transcriptase-polymerase chain reaction (RT-PCR) for14 Macrophage colonystimulating factor (M-CSF) as a growth factor required for bovine M-CSF was denaturation at 94$^{\circ}C$ for 1 minute, annealing at 57$^{\circ}C$ for 1 minute, extension at 72$^{\circ}C$ for 1 minute for 30 cycles. The size of cDNA of bovine M-CSF by RT-PCR was 774 base pairs. A 774 base pairs cDNA encoding bovine M-CSF was synthesized by reverse transcriptase polymerase chain reaction (RT-PCR). Ligated cDNA was transformed to competent cells and then plasmid isolation and digestion was performed. Molecular cloning and sequencing were performed for cDNA of bovine M-CSF. The size of cloned cDNA of bovine M-CSF was 774base pairs. The homology of base sequence and amino acid sequence was 88% and 86% compared with known human M-CSF, respectively. From a high degree of sequence similarity, the obtained cDNA of bovine M-CSF is thought be a specific gene of bovine M-CSF.