• 한국항해항만학회지
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• 제30권2호
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• pp.125-130
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• 2006

Waves, which are the main source of ship motions in a seaway, considerably affect the performance of a ship. The study of waves and their impact on ship motions within harbors is an important aspect of the design and operation of harbors. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor. Such a prediction makes it possible to evaluate ship safety more accurately. The wave transformation model reported here is applied to actual ports based on Boussinesq wave equations both non-linear and dispersive wave processes be considered in order to capture physical effects such as wave shoaling, refractions, reflection and diffraction in variable depth environments. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor, Such a prediction makes it possible to evaluate ship safety more accurately and provide safe wave informations for navigation. Furthermore, a wave information support system is proposed for entering ships as one technique for improving the safety of ship operations. This system predicts the run of waves and reduces the danger by identifying the most dangerous point near the harbor entrance at the small wave groups.

• 한국해안해양공학회지
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• 제13권1호
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• pp.61-72
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• 2001

천해영역에서 적용 가능한 동수역학적 수치모형을 이용하여 규칙 입사파군이 수직으로 입사할 때 잠제에 의하여 발생되는 반사와 투과의 거동 특성을 해석하였다. 여러 입사파군 조건에서 계산된 잠제의 반사율과 투과율이 파군의 발달정도를 해석하기 위하여 제시된 변수들의 함수로 표시되었다. 입사파군과 잠제의 반사율 및 투과율의 관계를 정성적으로 해석한 결과, 고파군이 발달될수록 잠제에 의하여 발생되는 입사파랑의 반사율과 투과율의 크기가 감소하는 것으로 나타났다. 특히 파군으로 입사하는 경우의 반사율과 투과율이 단일 파랑으로 입사하는 경우의 반사율과 투과율에 비하여 상대적으로 작게 나타났다. 그러나 고파군과 고파군의 간격에 따른 반사율과 투과율의 차이는 크지 않은 것으로 나타났다. 비록 제한적이지만 본 연구에서 해석된 결과에 의하면 파랑 연이음의 평균을 이용할 때 입사파군과 잠제의 반사율 및 투과율의 관계가 가장 잘 해석될 수 있다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권2호
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• pp.160-176
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• 2017

The interaction of focused wave groups with a vertical wall is investigated based on the second order potential theory. The NewWave theory, which represents the most probable surface elevation under a large crest, is adopted. The analytical solutions of the surface elevation, velocity potential and wave force exerted on the vertical wall are derived, up to the second order. Then, a parametric study is made on the interaction between nonlinear focused wave groups and a vertical wall by considering the effects of angles of incidence, wave steepness, focal positions, water depth, frequency bandwidth and the peak lifting factor. Results show that the wave force on the vertical wall for obliquely-incident wave groups is larger than that for normally-incident waves. The normalized peak crest of wave forces reduces with the increase of wave steepness. With the increase of the distance of focal positions from the vertical wall, the peak crest of surface elevation, although fluctuates, decreases gradually. Both the normalized peak crest and adjacent crest and trough of wave forces become larger for shallower water depth. For focused wave groups reflected by a vertical wall, the frequency bandwidth has little effects on the peak crest of wave elevation or forces, but the adjacent crest and trough become smaller for larger frequency bandwidth. There is no significant change of the peak crest and adjacent trough of surface elevation and wave forces for variation of the peak lifting factor. However, the adjacent crest increases with the increase of the peak lifting factor.

• Restorative Dentistry and Endodontics
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• 제44권2호
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• pp.22.1-22.8
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• 2019

Objectives: The aim of this study was to investigate the effect of glide path preparation with PathFile and ProGlider nickel-titanium (NiTi) files on the cyclic fatigue resistance of WaveOne NiTi files. Materials and Methods: Forty-four WaveOne Primary files were used and divided into four groups (n = 11). In the first group (0 WaveOne), the WaveOne Primary files served as a control group and were not used on acrylic blocks. In the 1 WaveOne Group, acrylic blocks were prepared using only WaveOne Primary files, and in the PF+WaveOne group and PG+WaveOne groups, acrylic blocks were first prepared with PathFile or ProGlider NiTi files, respectively, followed by the use of WaveOne Primary files. All the WaveOne Primary files were then subjected to cyclic fatigue testing. The number of cycles to failure was calculated and the data were statistically analyzed using one-way analysis of variance (ANOVA) and the Tukey honest significant difference multiple-comparison test at a 5% significance level. Results: The highest number of cycles to failure was found in the control group, and the lowest numbers were found in the 1 WaveOne group and the PF+WaveOne group. Significant differences were found among the 1 WaveOne, PF+WaveOne, and control groups (p < 0.05). No statistically significant differences were found between the PG+WaveOne group and the other three groups (p > 0.05). Conclusion: Glide path preparation with NiTi rotary files did not affect the cyclic fatigue resistance of WaveOne Primary files used on acrylic blocks.

• 복식문화연구
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• 제12권5호
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• pp.702-706
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• 2004

Sensorial tests were executed to find the sensibility and texture of the fabrics. The physiological responses employed in this study was electroencephalogram(EEG). The purpose of this study is to find out how the sample groups responded to the texture of the woven silks and the woven ramie. The sample groups are of 10 males and females, age of 25. EEG was recorded a fast and slow alpha wave according to the texture of the textiles. The sample fabrics are of woven silk and woven ramie. The results obtained as be lows. When the sample groups touched the woven silk, they responded and showed more slow alpha wave than the woven ramie. The slow alpha wave raised when the sample groups felt comfort and relax. The fast alpha wave were more in the woven ramie, it raised when the people felt the tension and the anxiety. There was no significant difference between the male and the female. Woven silk has the soft and smoothness it causes comfort. The sensation of tactile was recorded through the EEG.

• PNF and Movement
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• 제12권2호
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• pp.97-106
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• 2014

Purpose: The purpose of this study was to investigate changes in EEG through attention. Concentration training and performing tasks are important factors in the improvement of motor learning ability. Methods: In the experiment, 22 healthy people were divided into two groups: the trail making test (TMT) group and the computerized neurocognitive function test (CNT) group. A one-way Neuro Harmony M test to see whether there was a significant difference among the groups. Results: The TMT group showed a significant increase in ${\alpha}$ wave, ${\alpha}$ wave sequence, and ${\beta}$ wave sequence; however, there were no significant differences in SMR wave, SMR wave sequence, and ${\beta}$ wave. The CNT group showed increases in ${\alpha}$ wave, ${\alpha}$ wave sequence, SMR wave, SMR wave sequence, and ${\beta}$ wave sequence; however, there was no significant difference in ${\beta}$ wave. In EEGs before and after two performance tasks were changed, there were significant differences in ${\beta}$ wave, SMR wave, SMR wave sequence; however, there were no significant differences in ${\alpha}$ wave sequence, ${\beta}$ wave, and ${\beta}$ wave sequence. Conclusion: Attention training and concentration training offer feedback and repetition for constant stimulus and response. Moreover, attention training and concentration training can contribute to new studies and motivation by developing fast sensory and motor skills through acceptable visual and auditory stimulation.

• 대한정형도수물리치료학회지
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• 제13권2호
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• pp.1-11
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• 2007

Purpose: The purpose of this study was to determine the effect of continuous wave ultrasound and pulsed wave ultrasound that influence changes in pain and range of motion when applied to patients with temporomandibular joint disability. Methods: The subjects of the study were 40 selected patients who had been diagnosed with temporomandibular joint movement restriction and had endured pain for more than two weeks. These patients had visited K orthopedic surgery in Deagu measured from October 1, 2004 to March 31, 2005. The subjects were divided into two groups with 20 patients each. The one group was applied to continuous wave ultrasound and the other group was applied to pulsed wave ultrasound at a dosage of 1.5 W/$cm^2$ for a duration of 5 minutes and eight times for two weeks. The pain perception degree were measured by using Visual Analogue Scale(VAS) and the range of motion was measured by using a rule for each group. Results: The results obtained were as follows The change in the pain perception degree were statistically significant in both group(p<0.05) ; however, the continuous wave ultrasound group showed more difference in the average decrease in the pain perception degree than did the pulsed wave ultrasound group. Both groups showed significant results regarding changed in the range of motion(p<0.05) ; Comparing the difference in the average of the range of motion between the two groups, came back from normal the range of motion of temporomandibular joint at the both groups. Conclusion : Based on the results of this study, we found that both groups showed decreased pain and increased the range of motion, but the continuous wave ultrasound method had a higher therapy effect pain and the range of motion than the pulsed wave ultrasound method to patients with temporomandibular joint disability. With such finding, we expect that according to ultrasound therapy applicant method can be helped usable accurately to patients with variety symptoms temporomandibular joint disability.

• The Journal of Asian Finance, Economics and Business
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• 제2권4호
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• pp.13-20
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• 2015

The purpose of this research is to identify the relation between the Korean wave and Korean cosmetics export. Instead of using UN COMTRADE data as with other researches on the similar studies, this paper adopts Google Trends query index with keyword 'Korean drama'as a proxy variable for cultural trade. With controlling export determining factors such as GDPs of import and export countries, distance, R&D, and FTA, this paper examines whether the Korean wave represented by Google Trends contributes to the explosive increase of Korean cosmetics export in the recent years. Moreover, this study also investigates the possible effects of the Korean wave on export that could vary according to the different trade groups by classifying import countries into two groups: 74 countries worldwide and 9 ASEAN member countries. The results reveal that the Korean wave indeed leads to cosmetics export to ASEAN countries but show weak relation with cosmetics export to worldwide.

• Restorative Dentistry and Endodontics
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• 제24권3호
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• pp.490-494
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• 1999

The aim of this in vitro study was to investigate the coronal leakage of obligate anaerobes into root canals obturated with two different techniques. 48 extracted human teeth with straight, single root canals were prepared with crown-down technique with Profile under copious irrigation until the master apical file was size 40. The teeth were divided randomly into experimental groups (40 teeth) and control groups (8 teeth). In the experimental groups, 20 teeth were obturated with lateral condensation and other 20 teeth were obturated with continuous wave technique with System B. Coronal leakage of two root canal filing technique was evaluated using anaerobic bacterial leakage model with Fusobacterium nucleatum(ATCC 25586) for 60 days. The results were as follows 1. The incidence of bacterial leakage of experimental groups was 65% in group 1 (lateral condensation) and 60% in group 2 (continuous wave technique with System B). This difference was not statistically significant (P>0.05). 2. There was no statistically significant difference(P>0.05) in leakage score between group 1 (lateral condensation) and group2 (continuous wave technique with System B).

• Physical Therapy Rehabilitation Science
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• 제3권2호
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• pp.142-147
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• 2014

Objective: This study aims to investigate high energy and low energy extracorporeal shockwave therapy (ESWT) and which one is more effective for shoulder pain. Design: Single blind randomized controlled trial. Methods: Fifty two subjects with upper trapezius (UT) trigger point (TrP) participated in this study. They were allocated to high energy (n=26) and low energy group (n=26). This study applies ESWT and investigates the changes of pressure pain threshold (PPT) and visual analogue scale (VAS). The high and low energy groups received focused piezo electric type ESWT 4 Hz, 1,000 pulses and 0.351 and $0.092mJ/mm^2$ respectively. Outcome measures of PPT and pain was measured by algometer and pain VAS. These measurements were performed before and after treatment. Results: The PPT value was significantly increased in both groups after treatment (p<0.05) and VAS scores were significantly decreased after treatment in both groups (p<0.05). However, there were no significant differences between groups. Conclusions: ESWT is an effective treatment for the application of the UT TrP. Although there were significant effects of extracorporeal shock wave therapy on PPT and VAS scores, there were no signficant differences between high and low energy extracorporeal shock wave therapy.