• Title/Summary/Keyword: Lee Sang Hyuk

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TIME-DEPENDENT EFFECTS OF EDTA APPLICATION ON REMOVAL OF SMEAR LAYER IN THE ROOT CANAL SYSTEM (EDTA의 세정시간에 따른 근관 내 smear layer의 제거효과에 관한 연구)

  • Lee, Ja-Kyong;Park, Sang-Hyuk;Choi, Gi-Woon
    • Restorative Dentistry and Endodontics
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    • v.31 no.3
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    • pp.169-178
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    • 2006
  • This study was to verify that the combined application of NaOCl and EDTA was more effective in removal of smear layer than the application of NaOCl alone. furthermore it was aimed to find out the optimal time for the application of EDTA. Thirty five single rooted teeth were cleaned and shaped. NaOCl solution was used as an irrigant during instrumentation. After instrumentation, root canals of the control group were irrigated with 5 ml of NaOCl for 2 minutes. 30 sec, 1 min, and 2 min group were irrigated with 5 ml of 17% EDTA for 30 sec, 1 min, and 2 min respectively. Then the roots were examined with scanning electron microscopy for evaluating removal of smear layer and erosion of dentinal tubule. The results were as follows; 1. The control group: The smear layer was not removed at all. 2. The other groups: 1) $Middle\frac{1}{3}$: All groups showed almost no smear layer. And the erosion occurred more frequently as increasing irrigation time. 2) $Apical\frac{1}{3}$: The cleaning effect of 2 min group was better than the others. The results suggest that 2 min application of 17% EDTA should be adequate to remove smear layer on both $apical\frac{1}{3}\;and\;middle\frac{1}{3}$.

A Study on Developing Crash Prediction Model for Urban Intersections Considering Random Effects (임의효과를 고려한 도심지 교차로 교통사고모형 개발에 관한 연구)

  • Lee, Sang Hyuk;Park, Min Ho;Woo, Yong Han
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.1
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    • pp.85-93
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    • 2015
  • Previous studies have estimated crash prediction models with the fixed effect model which assumes the fixed value of coefficients without considering characteristics of each intersections. However the fixed effect model would estimate under estimation of the standard error resulted in over estimation of t-value. In order to overcome these shortcomings, the random effect model can be used with considering heterogeneity of AADT, geometric information and unobserved factors. In this study, data collections from 89 intersections in Daejeon and estimates of crash prediction models were conducted using the random and fixed effect negative binomial regression model for comparison and analysis of two models. As a result of model estimates, AADT, speed limits, number of lanes, exclusive right turn pockets and front traffic signal were found to be significant. For comparing statistical significance of two models, the random effect model could be better statistical significance with -1537.802 of log-likelihood at convergence comparing with -1691.327 for the fixed effect model. Also likelihood ration value was computed as 0.279 for the random effect model and 0.207 for the fixed effect model. This mean that the random effect model can be improved for statistical significance of models comparing with the fixed effect model.

A Study on Safety Impacts for VMS Traffic Information (VMS 교통정보의 교통안전효과에 관한 연구)

  • Lee, Sang Hyuk;Cho, Hye Jin
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.1
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    • pp.22-30
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    • 2015
  • Recently ITS have been increasingly applied on the roads to resolve traffic problems. Especially, Variable Message Sign (VMS), which is the one of ITS for traffic management and traffic safety, can be used for providing information about road conditions, climate conditions. In this study, data acquisition and statistical analysis were conducted for estimating safety impacts of providing traffic information through VMS. As a result of analyzing traffic characteristics before and after providing traffic information through VMS, average travel speed was decreased and vehicles tended to drive on centerline of lanes in 1st and 2nd lane after providing traffic information through VMS. Also, in order to analyze safety impacts of provided VMS traffic information, traffic safety hazard zone was established in each lane and probability distributions of passing traffic on the study area was estimated through Anderson-Darling Test. As a result of this, safety impacts of VMS traffic information in 1st lane could, on average, increase in left and right side of the lane by 0.69% and 7.07%, respectively. In case of 2nd lane, safety impacts could, on average, increase in left and right side of the lane by 2.71% and 0.02%, respectively.

Korean Medication Algorithm for Panic Disorder 2008 : Diagnosis, Treatment Response and Remission of Panic Disorder in Korea (한국형 공황장애 약물치료 알고리듬 2008 : 공황장애의 진단, 치료 반응과 관해의 평가)

  • Kim, Min-Sook;Yu, Bum-Hee;Kim, Chan-Hyung;Yoon, Se-Chang;Lee, Sang-Hyuk;Suh, Ho-Suk;Yang, Jong-Chul
    • Anxiety and mood
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    • v.4 no.1
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    • pp.49-54
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    • 2008
  • Objective : This article is a part of the Korean Medication Algorithm Project for Panic Disorder, which aims to build consensus regarding the diagnosis, treatment response and achievement of clinical remission for patients with panic disorder in Korea. Methods : The questionnaire used in this article had parts : 1) diagnosis, 2) treatment response, and 3) remission for patients with panic disorder. The questionnaire was completed by each of 54 Korean psychiatrists who had much experience in treating patients with panic disorder. We classified the experts' opinions into 3 categories (first-line, second-line, and third-line) using the ${\chi}^2$-test. Results : Five factors were considered in this research : panic attack, anticipatory anxiety, phobic avoidance, severity of illness, and psychosocial disability. Most reviewers agreed that the presence of a panic attack was the most important factor in the diagnosis of patients with panic disorder. Phobic avoidance was included in the first-line category, whereas the severity of illness and psychosocial disability were included in the second-line category. Most reviewers also agreed that the presence of a panic attack was the most important factor in determining the appropriate treatment response, and it was included in the first-line category along with several other items. To determine remission status, the patients' scores on tests pertaining to the severity of panic attack, anticipatory anxiety, phobic avoidance, severity of illness and psychosocial disability should be less than 3.0-3.3 on a 9-point Likert scale. Conclusion : We suggest useful information for making a diagnosisof panic disorder, determining the appropriate treatment response and identifying remission in panic disorder patients on the basis of the results of a nationwide survey of experts in Korea.

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Vegetation Structure and Management Plan for Windbreak Forests along the West Coast in Korea (서해안 방풍림의 식생구조 및 관리 방안)

  • Kim, Hyun-Jun;Jeong, Seong-Hun;Hwang, Chang-Hyuk;Kim, Hyun;Choi, Soo-Min;Lee, Sang-Hyun
    • Journal of agriculture & life science
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    • v.46 no.1
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    • pp.71-81
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    • 2012
  • This study was conducted to get basic information about making windbreak forest around Saemanguem reclaimed lands by analyzing the vegetation structure of 8 windbreak forests along the west coast of Korea and considering the methods of structural improvement. The total plants existing in the study areas were 25 families 40genus 43 species, and every tree layer consisted of only one tree species, Pinus thunbergii. There were 2 windbreak stands consisted of a species, and 2 consisted of multiple layer with a species. While, 4 windbreak stands consist of various species with several species. To make ecological system and functions of windbreak forests stabler, TL, STL and SL should be together in the vertical point, moreover, TL should be appeared at the in side and SL should be planted at the out side in the horizontal point. It is considered that mixed stand forest might be suitable for increasing the windbreak forest's functions and decreasing damage caused by disease and insects.

IEEE 802.11a Technnical Analysis and Research for Development of Unmanned Vehicle System (무인자동차 시스템 개발을 위한 IEEE 802.11a 기술 분석 및 연구)

  • Kim, Young-Hyuk;Choi, Sang-Wook;Lim, Il-Kwon;Choi, Jeong-Dan;Lee, Jae-Kwang
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.108-111
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    • 2009
  • In this paper, the development of unmanned vehicle systems to analysis applicable communications and alternative IEEE 802.11a. IEEE 802.11b/g uses the 2.4GHz. So, using the 5GHz OFDM in IEEE 802.11a interference phenomenon better. IEEE 802.11a has a maximum speed of 54Mbps. Indoors and apartment parking on experiment to soft roaming, hard roaming. Test equipments are AP four units(RSU), reliable results for the AP one unit Bridge, Switch one unit, one server notebook, one notebook(OBU), one car. Use Softwares are Wireshark, Jperf, Ping and million second transfer was used to develop the program. So the actual car was similar to the environment. With the results of the experiment for the unmanned vehicle systems will provide the best method.

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A Study on Preparation of Water in Oil in Water (W1/O/W2) Emulsion Containing Titrated Extract of Centella asiatica (센텔라 아시아티카 정량추출물을 함유한 Water in Oil in Water (W1/O/W2) 에멀젼 제조에 관한 연구)

  • Seo, Dong Hoan;Lee, Hong Seon;Yoon, Jong Hyuk;Kim, Youn Joon;Byun, Sang Yo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.41 no.4
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    • pp.303-313
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    • 2015
  • Titrated extract of Centella asiatica (TECA), which is poorly soluble in water is well known for wound healing and anti wrinkle agent. This study was conducted to find the optimum condition for the preparation of water in oil in water ($W_1/O/W_2$) emulsion containing TECA. Solubility of TECA were measured by UV spectrophotometer. 2.55 g of TECA was dissolved in solution composed of dipropylene glycol (40.0 g), ethanol (20.0 g), and water (10.0 g). Factors affecting stability of the emulsions ($W_1/O$, $W_1/O/W_2$) was investigated. The optimum conditions for the preparation of $W_1/O$ emulsion was composed of dipropylene glycol : ethanol : water : TECA in a weight ratio of 40.0 : 20.0 : 10.0 : 2.5 for water phase and squalane : cetyl PEG/PPG-10/1 dimethicone : cetearyl alcohol in a weight ratio of 22.5 : 4.0 : 2.5 for oil phase. The optimum conditions for the preparation of $W_1/O/W_2$ multiple emulsion was composed of water : $W_1/O$ emulsion : polysorbate 80 : carbomer : triethanolamine in a weight ratio of 55.8 : 40.0 : 4.0 : 0.1 : 0.1.

Linewidth Reduction of a Yellow Laser by a Super-cavity and the Measurement of the Cavity Finesse (초공진기를 이용한 노란색 레이저의 선폭 축소 및 초공진기의 예리도 측정)

  • Lee, Won-Kyu;Park, Chang-Yong;Park, Sang-Eon;Ryu, Han-Young;Yu, Dai-Hyuk;Mun, Jong-Chul;Suh, Ho-Suhng
    • Korean Journal of Optics and Photonics
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    • v.21 no.3
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    • pp.123-128
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    • 2010
  • Sum frequency generation was utilized to obtain a yellow laser with the wavelength of 578.4 nm for a probe laser of an Yb lattice clock. The output of an Nd:YAG laser with wavelength of 1319 nm and that of an Yb-fiber laser with wavelength of 1030 nm were passed through a waveguided periodically-poled lithium niobate (WG-PPLN) for sum frequency generation. It is required that the probe laser has a linewidth of the order of 1 Hz to fully resolve the Yb lattice clock transition. Thus, the linewidth of the probe laser was reduced by stabilizing the frequency to a super-cavity. This was made of ULE with a low thermal expansion coefficient, and was mounted on an active vibration-isolation table at the optimal point for the reduced sensitivity to vibration. Also, this was installed in a vacuum chamber, and the temperature was stabilized to 1 mK level. This system was installed in an acoustic enclosure to block acoustic noise. The finesse of the super-cavity was measured to be 380 000 from the photon life time of the cavity.

A Retrospective Study on the Clinical Safety of Bee Venom Pharmacopuncture at Craniofacial Acupuncture Points for the Treatment of Facial Disorders

  • Lee, Chang Hee;Yoon, Jin-Young;Shim, Sung-Eun;Kim, Jeong Hyun;Kim, Jun-Yeon;Kim, Ha-Na;Hwang, Ji-Min;Kim, Jung-Hyun;Goo, Bon Hyuk;Park, Yeon-Cheol;Seo, Byung-Kwan;Baek, Yong-Hyeon;Nam, Sang-Soo
    • Journal of Acupuncture Research
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    • v.36 no.4
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    • pp.245-250
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    • 2019
  • Background: This study was designed to evaluate the clinical safety of Bee Venom (BV) pharmacopuncture at craniofacial acupuncture points. Methods: This was a retrospective study of 108 patients diagnosed with peripheral facial paralysis, trigeminal neuralgia, or facial spasm who were admitted to Kyung Hee University Korean Medicine Hospital at Gangdong, from April 1st, 2017 to August 30th, 2017. Patients were allocated into either, Group 1 (the non-allergy group of patients who did not have an allergic reaction to BV) or Group 2, the group who had allergic reactions to BV. To evaluate the clinical safety of BV pharmacopuncture after each treatment, several criteria were used to measure any side effects: outcome, Common Terminology Criteria for Adverse Events scale, Mueller HL scale, treatment decision after adverse reaction, causality, measures performed for patients with adverse reactions, and efficacy assessment. Results: BV pharmacopuncture delivered in 0.1-0.2 mL at a concentration of 1:30,000 at the craniofacial acupuncture points, showed no statistically significant differences in baseline characteristics between non-allergy Group 1 and allergy Group 2. Amongst the 108 patients, 11 reported side effects after BV pharmacopuncture treatment. These adverse events included rash (n = 7), pruritus (n = 5), swelling (n = 1), vesicles (n = 1), erythema (n = 1), and hives (n = 1). All side effects resolved without sequelae. Conclusion: In this study, BV pharmacopuncture delivered at low doses at the craniofacial acupuncture points, resulted in 10% of patients experiencing non serious side effects suggesting that BV pharmacopuncture was clinically well tolerated.

Psoraleae Semen Ethanol Extract Inhibits RANKL-Induced Osteoclast Differentiation and Osteoclast Specific Genes Expression (보골지 추출물이 파골세포 분화 및 골흡수 관련 유전자 발현에 미치는 영향)

  • Ryu, Gwang-hyun;Kim, Eom Ji;Kim, Minsun;Kim, Jae-Hyun;Lee, Yujin;Jin, Dae-hwan;Sohn, Youngjoo;Jung, Hyuk-Sang
    • Korean Journal of Acupuncture
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    • v.38 no.3
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    • pp.140-150
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    • 2021
  • Objectives : The increase of osteoclasts could cause osteoporosis and bone-related diseases. Also, the inhibition of osteoclast differentiation is important in treating bone-related diseases. Traditionally, Psoraleae Semen has been used for geriatric diseases, aging and musculoskeletal diseases. The purpose of this study is to investigate the effect of Psoraleae Semen ethanol extract (PS) on osteoclast differentiation and its function. Methods : To confirm the effect of PS on osteoclastogenesis and bone resorption activity, various levels of concentrations of PS (5, 10, 20 and 40 ㎍/ml) were tested on RAW 264.7 cells cultured with RANKL. We measured tartarate-resistant acid phosphatase (TRAP)-positive cells, TRAP activity, pit formation and F-actin ring formation. The expressions of nuclear factor of activated T-cells (NFATc1) and c-Fos were confirmed through western blot and reverse transcription- polymerase chain reaction (RT-PCR). Also, the expression of bone resorption and fusion-related genes in osteoclast was confirmed by RT-PCR. Results : PS decreased the number of TRAP-positive cells and the TRAP activity. In addition, PS significantly inhibited the formation of pit and F-actin ring. Furthermore, PS decreased the expression of osteoclast related genes. Conclusions : PS inhibits osteoclast differentiation and bone resorption ability through inhibition of the expression of osteoclast-related genes. This indicates that PS may be a potential therapeutic agent to osteoporosis by suppressing osteoclastogenesis.