• Journal of Periodontal and Implant Science
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• v.50 no.1
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• pp.38-47
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• 2020

Purpose: The aim of this study was to investigate the available alveolar bone height between the maxillary molars and the sinus floor according to their anatomical relationship using cone-beam computed tomographic (CBCT) images. Methods: A total of 752 maxillary first (M1) and second molars (M2) on CBCT scans of 188 patients were selected. First, each maxillary molar was categorized as type 1, 2, 3, or 4 according to the relationship of the molar root with the maxillary sinus floor. The frequency distribution of each type was analyzed. Second, the shortest vertical distance (VD) of each molar was measured from the furcation midpoints of the roots to the lowest point of the sinus floor by 2 observers. Intraclass correlation coefficients and the t-test were calculated for the VD measurements. Results: For M1, type 3 was the most frequent, followed by type 2. For M2, type 3 was the most common, followed by type 1. The VD measurements of type 1 were 9.51±3.68 mm and 8.07±2.73 mm for M1 and M2, and those of type 3 were 3.70±1.52 mm and 4.03±1.53 mm for M1 and M2, respectively. The VD measurements of M2 were significantly higher in female patients than in male patients. Conclusions: Type 3 was the most frequent anatomical relationship in the maxillary molars, and showed the lowest alveolar bone height. This information will help clinicians to prevent complications related to the maxillary sinus during maxillary molar treatment and to predict the available bone height for immediate implant planning.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.39-46
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• 2006

The fuel cell is one of promising environment-friendly energy sources for the next generation. The bipolar plate is a major component of the PEM fuel cell stack, which takes a large portion of stack cost. In this study, as alternative materials for bipolar plate of PEM fuel cells, graphite composites were fabricated by compression molding. Graphite particles mixed with epoxy resin were used as the main substance to provide electric conductivity To achieve desired electrical properties, specimens made with different mixing ratio, processing pressure and temperature were tested. To increase mechanical strength, one or two layers of woven carbon fabric were added to the graphite and resin composite. Thus, the composite material was consisted of three phases: graphite particles, carbon fabric, and epoxy resin. By increasing mixing ratio of graphite, fabricated pressure and process temperature, the electric conductivity of the composite was improved. The results of tensile test showed that the tensile strength of the two-phase graphite composite was about 4MPa, and that of three-phase composite was increased to 57MPa. As surface properties, contact an91e and surface roughness were tested. Graphite composites showed contact angles higher than $90^{\circ}$, which mean low surface energy. The average surface roughness of the composite specimens was $0.96{\mu}m$.

• The Journal of Korean Physical Therapy
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• v.28 no.6
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• pp.381-384
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• 2016

Purpose: Previous studies reported changes in the first metatarsophalangeal (MTP) joint angle in relation with and without weight bearing, but it is unclear whether sesamoid bone of the great toe changes in weight bearing conditions particularly in subjects with hallux valgus (HV). To investigate how weight bearing conditions can affect the position of the medial sesamoid bone (MSB), first MTP joint angle, and second intermetatarsal angle (IMA) in the recruited subjects. Methods: Subjects were recruited 24 with HV and 21 without HV in study. X-rays were taken in the weight bearing and non-weight bearing conditions. The distance of the MSB, first MTP joint angle, and second IMA were measured from the radiographs. Data were analyzed by paired and Independent t-test. The statistical significance level was p<0.05. Results: In both groups, the first MTP joint angles and the distance of the MSB were significantly smaller, while the second IMA was significantly greater in the weight bearing condition. The difference in the distance of the MSB between the two postures was significantly greater in the group with HV. Conclusion: Weight bearing can affect the first MTP joint angle, second IMA, and position of the MSB; the change in the position of the MSB in weight bearing was greater in the group with hallux valgus. The difference in these variables between weight bearing and non-weight bearing conditions may be considered when measuring HV.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.126-126
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• 2010

본 연구에서는 catalyst-free 유기금속 화학증착법 (MOCVD)를 이용하여 사파이어 (0001)면 위에 직접 InN nanorods를 성장하였다. InN 박막의 성장에서 TMIn과 $NH_3$를 전구체로 사용하였으며, 캐리어 가스로는 질소를 사용하였다. 성장 전, 기판에 $1100^{\circ}C$에서 3분간 nitridation 처리를 거친 후 온도를 낮춰 $630{\sim}730^{\circ}C$의 온도범위 에서 InN 박막을 성장하였다. 이때 $710^{\circ}C$의 온도에서 박막은 columnar growth의 특성을 보였으며 동일조건에서 80분간 성장시킨 결과 InN nanorods가 성장되었다. 성장시킨 InN nanorod는 X-선 회절 측정법, 주사 전자 현미경 그리고 투과 전자 현미경을 이용하여 그 특성을 분석하였다. 투과 전자 현미경을 통한 분석결과 지름이 150~200 nm이며 그 길이는 수 ${\mu}m$인 InN nanorod가 성공적으로 성장되었음을 확인하였다. 또한 X-선 회절 측정법과 주사 전자 현미경을 통한 분석에서 이들 nanorods가 대부분 c 방향으로 수직하게 정렬되어 있음을 확인하였다. 또한 Ti/Au (120/80 nm)를 전극으로 사용하여 개개의 nanorod의 전기적 특성을 분석한 결과 linear한 I-V특성이 관찰되었으며 비저항은 평균적으로 $0.0024\;{\Omega}cm$ 이었다. transfer 특성의 측정결과 -50V까지 게이트 전압을 인가하여도 드레인 전류의 변화는 매우 적어 doping level이 상당히 높다고 예상가능하다. 또한 mobility는 $133\;cm^2/Vs$로 도출되었다.

• Journal of Korea Water Resources Association
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• v.30 no.5
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• pp.549-559
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• 1997

A multiply-connected network unsteady flow model for the main reach of the Han River is developed. It is a variable parameter model which allows variable roughness coefficient for each computational point according to the spatial position and the value of discharge. Sensitivities of the model to roughness coefficient and weir-flow discharge coefficient are tested, and as a result Manning's roughness coefficient is selected as the calibration parameter. The model is calibrated and verified using the records of the past flood events. A modified Gauss-Newton method is used for the optimal calibration of roughness coefficients. From the calibration of variable parameter model, spatial variation and discharge dependence of Manning's roughness coefficient are identified. That is, the roughness coefficient is higher for the upstream reach of the Wangsook stream Junction, and it decreases as the discharge increases. It turns out through the verification that the stages calculated by the variable parameter model agree better with the observed than those by the conventional single parameter model. Spatial variation of the roughness coefficient appears to be more significant than the dependence of the discharge.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.4
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• pp.147-152
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• 2018

Underwater transient signals are complex, variable and nonlinear, resulting in a difficulty in accurate modeling with reference patterns. We analyze one type of underwater transient signals, in the form of whale sounds, using the MFCC(Mel-Frequency Cepstral Constant) and synthesize them from the MFCC and the weighted $L_2$-norm minimization techniques. The whales in this experiments are Humpback whales, Right whales, Blue whales, Gray whales, Minke whales. The 20th MFCC coefficients are extracted from the original signals using the MATLAB programming and reconstructed using the weighted $L_2$-norm minimization with the inverse MFCC. Finally, we could find the optimum weighted factor, 3~4 for reconstruction of whale sounds.

• Biomolecules & Therapeutics
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• v.27 no.1
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• pp.107-116
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• 2019

The global obesity epidemic and associated metabolic diseases require alternative biological targets for new therapeutic strategies. In this study, we show that a phytochemical sulfuretin suppressed adipocyte differentiation of preadipocytes and administration of sulfuretin to high fat diet-fed obese mice prevented obesity and increased insulin sensitivity. These effects were associated with a suppressed expression of inflammatory markers, induced expression of adiponectin, and increased levels of phosphorylated ERK and AKT. To elucidate the molecular mechanism of sulfuretin in adipocytes, we performed microarray analysis and identified activating transcription factor 3 (Atf3) as a sulfuretin-responsive gene. Sulfuretin elevated Atf3 mRNA and protein levels in white adipose tissue and adipocytes. Consistently, deficiency of Atf3 promoted lipid accumulation and the expression of adipocyte markers. Sulfuretin's but not resveratrol's anti-adipogenic effects were diminished in Atf3 deficient cells, indicating that Atf3 is an essential factor in the effects of sulfuretin. These results highlight the usefulness of sulfuretin as a new anti-obesity intervention for the prevention of obesity and its associated metabolic diseases.

• Journal of Oriental Neuropsychiatry
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• v.29 no.4
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• pp.315-324
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• 2018

Objectives: The objective of this case report was to investigate the effect of Korean medicine therapy on migraine patients with typical aura. Methods: Acupuncture and chuna manual therapy were applied to outpatients once in 1 to 2 weeks, a total of 9 times, for about 11 weeks. A patient was diagnosed with ganyang-toutong and taeeumin dry-heat symptomatic pattern. Herbal medicine (Chongsanggeontong-tang Gagambang (淸上?痛湯加減方)) was prescribed for 15 days up to the 3rd visit, then another herbal medicine (Yeoldahanso-tang (熱多寒少湯)) prescribed for 15 days up to the 6th visit. MSQol and MIDAS were used as a tool at the start and after 9th treatment. The intensity and frequency of headache, frequency of aura and neck pain were examined on every visit. Results: According to the results, Korean traditional medicine described above had effect on the intensity and frequency of headache, frequency of aura and neck pain as well as an increase in the figure of MSQoL from 62 to 81 and decrease of MIDAS Disability from 18 to 7, Duration from 60 to 30, Pain score from 8 to 2. Conclusions: Migraine with typical aura classified as ganyang-toutong and taeeumin dry-heat symptomatic pattern can be alleviated by Korean traditional medicine.

• The Korea Journal of Herbology
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• v.36 no.4
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• pp.9-22
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• 2021

Objective : The purpose of this dissertation is to make a list of the phaeophyta growing naturally in the Korean coastal waters, and to carry out a survey on the current distribution status to investigate the phaeophyta which can be used as medicinal herbs. Methods : References and research papers about herbology published at home and abroad were examined. Results : The results of this study were as follows : A total of 63 genera and 145 species of phaeophyta was found in the Korean coastal waters among which 11 genera and 15 species(approximately 11%) were medicinal plants. Out of the 145 species of phaeophyta 27 species belonged to Sargassum, and out of the 15 species of medicinal plants 4 species belonged to Sargassum. Among the medicinal parts 11 species belonged to algae. Sixteen species had cold property, and 16 species had salty flavors. Thirteen species had the efficacy of liver meridian, and 15 species had the potency of YEONKYUN, which helps to remove hard clots generated in human body. No toxic drugs were detected. Conclusion : There were totaled to 63 genera and 145 species in Phaeophyta in Korea and among them medicinal plants are 11 genera, 15 species, some 11% in total. Thirteen species had the efficacy of liver meridian, and 15 species had the potency of YEONKYUN, which helps to remove hard clots generated in human body. No toxic drugs were detected.

• The Korea Journal of Herbology
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• v.34 no.1
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• pp.81-90
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• 2019

Objective : For the purpose of developing Verbenaceae plants recorded in Korean Herbology in Korea, the literatures of the successive generations have been thoroughly investigated to prepare this article. Methods : Books and research papers about Herbology which published at Korea and other countries were examined. Results : A list was made about Verbenaceae plant which were cultivated or grew naturally in Korea, after investigated the data on domestic and foreign Verbenaceae plants. Out of those lists, serviceable plants were selected and with those available plants, their distributions were analysed and parts which can be used as medicines were divided into 3 categories such as oriental medicine name, scientific name and non-official name. Verbenaceae's properties flavor, channels they use, effects, and toxicity were also noted. Verbenaceae(grew in Korea) were divided into 5 classes with 21 species. Out of those, 5 classes with 8 species were found serviceable which indicates 40% of all. Out of all 20 species of Verbenaceae family, Callicarpa genus were found 10 species, which were shown the most. Among 3 genus of Vitex species, medicinal plants were all one species each. Out of all serviceable parts in Verbenaceae, Folium parts took first place as 5 species. There are no toxic, the survey said. Conclusion : There were totaled to 5 genera and 21 species in Verbenaceae in Korea and among them medicinal plants are 5 genera, 8 species, some 38% in total.