• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.35-38
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• 2005

This paper suggests the method that forecast Dynamic Line Rating (DLR). Thermal Overload Risk (TOR) of next time is forecasted based on current weather condition and DLR value by Monte Carlo Simulation (MCS). To model weather element of transmission line for MCS, we will propose the use of weather forecast system and statistical models that time series law is applied. Also, through case study, forecasted TOR probability confirmed can utilize by standard that decide DLR of next time. In short, proposed method may be used usefully to keep safety of transmission line and reliability of supply of electric Power by forecasting transmission capacity of next time.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.26-30
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• 1999

The constraint condition is the stator voltage and the stator current to operate the motor in the flux weakening region. The maximum current is limited by the inverter current rating and the machine thermal rating. Given DC link voltage to control the motor in the flux weakening the maximum voltage is determined by considering PWM strategy, dead time, voltage drop of the inverter switching device, and the margin of the voltage for current forcing. In this paper, the new method to determine the available maximum voltage is derived by the analythic method and by considering the factors of the voltage drop. So Determining the maximum voltage is very useful to enlarge the speed operation region in the flux weakening operation, the utility of the maximum voltage is increased.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.259-262
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• 2002

Application of combustion stabilization devices such as baffle and acoustic cavity to liquid propellant rocket engine is investigated to suppress high-frequency combustion instability, i.e., acoustic instability. First, these damping devices are designed based on linear damping theory. As a principal design parameter, damping factor is considered and calculated numerically in the chambers with various specifications of these devices. Next, the unbaffled chambers with/without acoustic cavities are tested experimentally for several operating conditions. The unbaffled chamber shows the specific stability characteristics depending on the operating condition and has small dynamic stability margin. The most hazardous frequency is clearly identified through Fast Fourier Transform. As a result, the acoustic cavity with the present design has little stabilization effect in this specific chamber. Finally, stability rating tests are conducted with the baffled chamber, where evident combustion stabilization is observed, which indicates sufficient damping effect. Thrust loss caused by baffle installation is about $2{\%}$.

• Journal of the Korean Society of Food Culture
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• v.9 no.1
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• pp.95-103
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• 1994

Hospitalized patients' perceptions of the quality of hospital food and their importance were surveyed through questionnaires by 820(men 435, women 385) hospitalized patients in Seoul. The results are as follows: Men rated the size of food portion as being smaller, compared with women. The mean rating for nutrition of food was 3.24, freshness 3.15, taste 2.88, temperature 2.82; Among the food characteristics, nutrition was considered important by largest percentage(75.5%) of respondents, the taste ranked second(74.4%), and freshness was 62.2%; Appetite, atmosphere of ward were positively correlated(p<0.001) with rating of the taste, nutrition, and freshness, but length of hospitalization was negatively correlated (p<0.001) with them; Multiple regression analysis showed that appetite made the greatest contribution and length of hospitalization made the second greatest contribution. The third was atmosphere of ward, and the forth mood condition.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.8
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• pp.455-460
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• 1999

A novel zero-voltage-transition (ZVT) PWM converter for switched reluctance motor (SRM) drives is proposed. A simple auxiliary circuit which consists of one active switch, one resonant inductor, and three diodes provides ZVS condition to all main switches and diodes allowing high frequency operation of the converter with high efficiency. The auxiliary circuit is placed in parallel with the main power flow path and thus it handles only a small fraction of the main power. So, the power rating of the auxiliary circuit can be very small (about 30% of main power). So, the auxiliary circuit can be realized with small power rating and low cost. Operation, features and characteristics of the proposed converter are illustrated and verified on a 1.5 kW, 50 kHz IGBT based (a MOSFET for the auxiliary with) experimental circuit.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.269-272
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• 1998

This paper presents an UPFC(Unified Power Flow Controlled model that considered rating for stability study. The proposed UPFC model was implemented by PSS/E and IPLAN. As a control strategy for damping electromechnical oscillations, energy function method was adopted. By the adopted control law, the damping effect is robust with respect to loading condition, fault location and network structure. The effect of control of the UPFC model was demonstrated on a one machine infinite bus system.

• Journal of Acupuncture Research
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• v.39 no.1
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• pp.49-52
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• 2022

Benign essential blepharospasm (BEB) is a condition/disease which involves involuntary muscle contractions causing the eye to repetitively close, making it impossible for the patient to perform daily activities. This study reports Korean medicine treatment of a rare case BEB in a 34-year-old male patient whose symptoms showed minimal improvement following botulinum toxin injection (the standard treatment). Acupuncture, pharmacopuncture, and herbal medicine treatment for 11 days resulted in clinical improvement for all symptoms as assessed by using the Jankovic Rating Scale, Blepharospasm Disability Index, numerical rating scale, duration of spasms lasting more than 1 hour per day, and number of spasms lasting less than 1 minute per day. This case report suggests that comprehensive Korean medicine treatment could be a treatment option for BEB in patients who do not respond well to botulinum toxin injection.

• Journal of KIISE
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• v.44 no.5
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• pp.486-495
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• 2017

Collaborative Filtering is limited because of the cost that is required to perform the recommendation (such as the time complexity and space complexity). The RFWBP (Rating Frequency Weight-based Baseline Predictor) that approximates the precision of the existing methods is one of the efficiency methods to reduce the cost. But, the following issues need to be considered regarding the RFWBP: 1) It does not reduce the error because the RFWBP does not learn for the recommendation, and 2) it recommends all of the items because there is no condition for an appropriate recommendation list when only the RFWBP is used for the achievement of efficiency. In this paper, the BBP (Bias-Based Predictor) is proposed to solve these problems. The BBP reduces the error range, and it determines some of the cases to make an appropriate recommendation list, thereby forging a recommendation list for each case.

• The Journal of Korean Medicine
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• v.25 no.1
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• pp.198-204
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• 2004

Backgrounds & Methods : Asthma is considered to be chronic inflammatory disease characterized by airway hyperresponsiveness and pulmonary eosinophilia. Recently, there has been many researches about asthma. IBS(Irritable Bowel Syndrome), PUD(peptic Ulcer disease) and GERD(gastroesophageal reflux disease) are the most common diseases of the gastrointestinal tract. Recent studies suggest that IBS, PUD and GERD are associated with bronchial hyper-responsiveness and bronchial asthma might be more prevalent in IBS and GERD patients than in control subjects. In addition, there are many comments about the interrelationship between the gastrointestinal problem and asthma in the oriental medical books. Actually, many oriental medical doctors don$^{\circ}$Øt consider the gastrointestinal condition when they deal with the asthmatic patients these days. So, we assessed the prevalence of gastrointestinal symptoms and histories in a cohort of patients with asthmatic symptoms. We evaluated 128 outpatients with asthmatic symptoms(60 males and 68 females, aged 13-75). All subjects enrolled completed the GSRS(Gastrointestinal Symptom Rating Scale). GSRS is an interview based rating scale consisting of 15 items for assessment of gastrointestinal symptoms in IBS and PUD developed by Jan Svedlund. Results : The limit of total score of GSRS in asthmatic patients is zero to 30. The number of patients with no GI symptoms is 66(51.5%). The number of patients with GSRS>5 is 62(48.4%), GSRS>10 is 24(18.8%), GSRS>15 is 8(6.25%). The number of patients with history of gastritis is 54(42.2%), gastric ulcer is 13(10.2%), gastroptosis is 8(6.25%), IBS is 6(4.68%), others is 6(4.68%). Conclusions : This study suggests that patients with bronchial asthma have an significant prevalence of gastrointestinal symptoms. Additional studies are needed to find the mechanism of the association between gastrointestinal symptoms and asthma.

• Textile Coloration and Finishing
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• v.29 no.3
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• pp.171-179
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• 2017

This study was to investigate the practicality and functionality of water lily(Nymphaea tetragona) leaves as a natural dye resource while searching for various dyeing methods to utilize them. Effect of dyeing condition including methanol ratio of dyebath, dyeing temperature and time, mordanting method, etc were investigated. Colorants were prepared by extraction in methanol and followed drying process. When composing 30% of methanol in the dyebath, better dyeuptake and uniform dyeing were resulted. Pre-mordanting method gave better results in terms of dye uptake than post-mordanting method on the wool fabrics. Fe and Ti were effective for increasing the dye uptake on the silk fabrics. Depending on mordant type and mordanting method, the dyed fabrics got various color showing green, khaki, brownish yellow, dark brown, dark gray and so on. As for color fastness, the silk fabrics dyed with water lily extract showed relatively high rating in light fastness(3~4, 4~5 rating), washing fastness(4~5, 5 rating), and rubbing fastness(4, 4~5 rating). The silk and wool fabrics dyed with water lily leaves extract showed excellent antimicrobial activity over 98% of bacterial reduction rate against Staphylococcus aureus and Klebsiella pneumoniae. It was confirmed that water lily leaves can be used as a natural dye resource for dyeing wool and silk fabrics because its colorants showed excellent affinity and antimicrobial functionality as well as good colorfastness.