• 한국염색가공학회지
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• 제28권3호
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• pp.156-163
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• 2016

The 6 novel super hydrophobic bluish-green dyes, showing the maximum absorption at 600~650nm, were synthesized to dye polyolefin fibers such as polypropylene and high strength polyethylene fibers. Their absorption spectra appeared almost the same at visible range, which meant the length of alkyl substituents did not affect on color appearance of the dyes. The optimum length of alkyl group was determined as hexyl substituents from the practical point of view. From the dyeing results, the optimum dyeing condition was $130^{\circ}C$ for 1 hour. The good fastness ratings to washing, rubbing were obtained showing 4-5 for both fibers. Light fastness was obtained also good rating 4 for both fibers.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권3호
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• pp.130-140
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• 2001

This paper presents the performance of a parallel active power filter(PT) system in unbalanced load condition. The unbalanced load leads to negative sequence of current, and makes 120Hz ripple in the DC-link voltage forcing large capacitance and increases the rating of APF. thus, the separation of negative sequence is performed in synchronous reference frame and controlled to flow into supply network. The validity of the scheme is investigated through simulation and the experimental results for a prototype active power filter system rated at 10kVA.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 추계학술대회
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• pp.99-107
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• 2009

Mahalanobis Taguchi-System (MTS) has been used in different diagnostic applications to make quantitative decisions by constructing a multivariate system using data analytic methods without any assumption regarding statistical distribution. MTS performs Taguchi's fractional factorial design based on the Mahahlanobis distance as a performance metric. In this study, MTS used for analyzing automotive ride satisfaction, which measured as a CSR(Customer Satisfaction Rating). The automobile which has a good CSR score treated as a normal group for constructing Mahalanobis space. The results of this research show that two attribute (Impact Hardness and Memory Shake) have a minus gain value and can be removed from further analysis. With the linear regression model, the difference of CSR between using all 6 attributes and just using significant 4 attributes compared.

• 사상체질의학회지
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• 제32권2호
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• pp.80-95
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• 2020

Introduction This study is the first case report to observe a significant improvement of clinical symptoms of both Recurrent Aphthous Stomatitis(RAS) and pompholyx treating with modified Palmulgunja-tang for Soeum-type. Case presentation A 37-year-old female patient complained of pain by ulcers on her mouth and tongue, and of itching caused by vesicles on her palms and soles was diagnosed with RAS, pompholyx, and, especially moderate pattern of 'Congestive Hyperpsychotic symptomatology' according to the theory of Sasang Constitutional Medicine(SCM). During inpatient and outpatient treatment, she took modified Palmulgunja-tang, and was treated with acupuncture, moxibustion, and cupping therapy. The effectiveness of these therapies was assessed with subjective Neumeral Rating Scale(NRS) and Dyshidotic Eczema Area and Severity Index(DASI). Conclusion After the treatment according to the theory of SCM, NRS, and DASI score about RAS and pompoholyx was decreased, and the general condition of the patient also has improved.

• 전기학회논문지P
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• 제57권1호
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• pp.36-40
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• 2008

Most of the low-voltage feeder are designed with approximately balanced and connected at the three phase four wire systems. However, Most of the power distribution systems' load which is composed of single or three phase are unbalanced by generating load unbalance. Unbalanced current will draw a highly unbalanced voltage. The power factor of an induction motor at rated operation is between 25 and 90%, depending on the size and speed of the motor. However, many induction motors operate below the nominal rating, resulting in poor power factor. This condition needs power factor improvement. Addition of power capacitor at the motor terminal may draw to stress due to voltage unbalance. This paper presents operation characteristics on steady states of a three-phase induction motor under unbalanced voltages with power capacitor. The existence of voltage unbalance have an effect on stress of power capacitor.

• 대한안전경영과학회지
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• 제4권3호
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• pp.25-34
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• 2002

The prevention of accidents or diseases is one of the most profitable activities in any business. The useful tools to diagnose existing safety problems and to systematically guide the improvement of those deficiencies have been developed in the world. In the recent, however, the importance of the interface between workers and workplaces has been increasingly recognized. In order to audit the correlations of job environments and workers we developed the rating system called "Ergonomic Workplace Assessment Index" for ergonomic condition in this study. The auditors will measure the degree of compliance of the criteria using judgement techniques, checks and interviews with EWAI(Ergonomic Workplace Assessment Index) which involves 5 categories and total 50 elements. elements.

• 한국건설관리학회논문집
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• 제4권1호
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• pp.81-89
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• 2003

This research suggests the FD-AHP decision making model for Construction Projects which is composed of two main method to prevent a ranking invert situation ; First, to make the consensus of the experts consistent, we utilize Fuzzy-Delphi method to adjust the fuzzy rating of every expert to achive the consensus condition with the fuzzy linguistic presentation. Second, to handle vague linguistic presentation caused by expert's experiences and subjective judgement, we propose Fuzzy-AHP which is able to enhance precision of construction projects decision mating situation. Moreover, with the correlation analysis, we show that the validity of the FD-AHP model under a decision making task specially on where highly demanded expert's experiences and intuition.

• 대한전기학회논문지
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• 제39권3호
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• pp.273-280
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• 1990

To prevent the shoot-through phenomena in a PWM inverter, a short dead time is usually provided between a pair of switching transistors in the same leg of the inverter. In this approach, the amount of the dead time is designed to meet the worst case condition of the inverter transistors and the base drive elements. So, in normal cases, relatively large portion of the dead time is unnecessary and it results in an undesirablecurrent waveform distortion and generates ripple torque on the motor shaft. In this paper, a new base drive method to remove the undesirable portion of the dead time is described. The method senses the transistor on/off states to interlock the other transistor of the leg without the external dead time. Also, for the transistors of large current rating, the Darlington drive circuit is combined to the proposed method and is tested to verify the effectiveness. The experimental results of the proposed method are described and compared with those of the conventional dead time method.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권12호
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• pp.686-691
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• 1999

In a switching power supply, the high frequency switching makes the passive components small, but the losses and the stresses of switches are increased by the switching frequency. Therefore, zero crossing technology using resonant is used to improve defect in high switching. In generally, zero crossing switching consists of Zero Current Switching(ZCS) and Zero Voltage Switching(ZVS). This paper proposes A Buck ZC-ZVS Converter with Reduced Conduction Losses. Comparing with a conventional Buck ZC-ZVS Converter, the proposed converter operates with the smaller rated power. This is achieved by changing the auxiliary switch position, which reduces its rating power. Simulation results using Pspice program about test circuit with rated 160W(30V, 5.3A) at 30kHz and experiment result under same condition were described in the paper.

• Journal of the Korean Data and Information Science Society
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• 제18권3호
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• pp.659-668
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• 2007

Collaborative filtering approach for recommender systems are now widely applied in e-commerce to assist customers to find their needs from many that are frequently available. this approach makes recommendations for users based on the opinions to similar users in the system. But this approach is opened to users who present their preference to items or acquire the preference information form other users, noise in the system makes significant problem for accurate recommendation. In this paper, we analyze the relationship between the standard deviation of preference ratings for each user and the estimated ratings of them. The result shows that the possibility of the pre-filtering condition which detecting the factor of bad effect on the prediction of user's preference. It is expected that using this result will reduce the possibility of bad effect on recommender systems.