• 보건의료산업학회지
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• 제7권3호
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• pp.83-93
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• 2013

This study was conducted on 350 students of health and medical department of universities in Busan from June 3, 2013 to June 21, 2013, and a total of 350 questionnaires were researched. Among them 337 responses were used after 13 unfaithful responses were excluded. The effects of oral health belief on use of dental service of students of health and medical department of universities were examined and analyzed to provide basic data which can be used to expand understanding about oral health belief, to promote changes in behaviors regarding oral health and to improve oral health of the public. Collected data was analyzed through SPSS (Statistical Packages for Social Science 15.0. SPSS Inc. USA). For verification of differences of oral health belief depending on general matters and oral health behavior, t-test and ANOVA analysis were conducted, and for examination of the effects of oral health belief on use of medical service, logistic regression and regression analysis were conducted. The study results suggest that those who had higher sensitivity among oral health belief variables had higher probability of needing dental treatment and seeing the dentist immediately. And those who showed higher sensitivity and importance had higher frequency of seeing the dentist for six months. Future studies need to be conducted on the methods to change oral health belief for sustainable and systematic oral health enhancement in consideration of the factors affecting oral health belief and oral health behavior of the students of dental hygiene department.

• The Korean Journal of Pain
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• 제23권1호
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• pp.18-23
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• 2010

Background: Complications following lumbar transforaminal epidural injection are frequently related to inadvertent vascular injection of corticosteroids. Several methods have been proposed to reduce the risk of vascular injection. The generally accepted technique during epidural steroid injection is intermittent fluoroscopy. In fact, this technique may miss vascular uptake due to rapid washout. Because of the fleeting appearance of vascular contrast patterns, live fluoroscopy is recommended during contrast injection. However, when vascular contrast patterns are overlapped by expected epidural patterns, it is hard to distinguish them even on live fluoroscopy. Methods: During 87 lumbar transforaminal epidural injections, dynamic contrast flows were observed under live fluoroscopy with using digital subtraction enhancement. Two dynamic fluoroscopy fluoroscopic images were saved from each injection. These injections were performed by five physicians with experience independently. Accuracy of live fluoroscopy was determined by comparing the interpretation of the digital subtraction fluoroscopic images. Results: Using digital subtraction guidance with contrast confirmation, the twenty cases of intravascular injection were found (the rate of incidence was 23%). There was no significant difference in incidence of intravascular injections based either on gender or diagnosis. Only five cases of intravascular injections were predicted with either flash or aspiration of blood (sensitivity = 25%). Under live fluoroscopic guidance with contrast confirmation to predict intravascular injection, twelve cases were predicted (sensitivity = 60%). Conclusions: This finding demonstrate that digital subtraction fluoroscopic imaging is superior to blood aspiration or live fluoroscopy in detecting intravascular injections with lumbar transforaminal epidural injection.

• Journal of Nutrition and Health
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• 제17권1호
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• pp.31-40
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• 1984

혐기적 조건밑에서 $FeCl_{3}$에 의해 촉진된 TBA 반응을 이용하여 혈청중 과산화물 측정을 위한 새로운미량 분석법을 설정하였다. 즉. 혈청단백침전물이 현탁된 TBA반응흔합액에 혈청 $10{\mu}l$당 $1.0{\mu}mole$의 $FeCl_{3}$를 첨가한 다음 질소기류밑에서 50분간 끊는 물에 중탕한다. 이 분석법의 반응 예민도는 현행 일반 TBA법보다 40여배나 증대되었으며 따라서 미량의 시료$(10{\sim}20{\mu}l)$로도 TBA반응생성물의 농도 측정이 비색법으로도 가능하였다. 그리고 TBA반응생성물의 butanol 추출액을 $(NH_{4})_{2}SO_{4}$염석으로 부분말수시킴으로써 예민성 및 재현성이 개선될 수 있었다. 이 분석법을 이용하여 측정한 건강인들의 혈청 TBA같은 높은 연령군일수록 증가하는 경향을 보였다.

• 한국결정성장학회지
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• 제7권2호
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• pp.276-283
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• 1997

함침법을 이용하여 Pt/$SnO_2$ pellet형 가스 센서를 제조하였다. 제조한 미세 분말에 대하여 전자회절 분석, 투과전자현미경, 주사선전자현미경 등의 분석으로 결정 구조 및 방향성, 결정 크기, 촉매와 담체와의 미세구조 등이 분석되었다. 투과전자현미경 사진으로부터 $400^{\circ}C$에서 하소했을 때 $PtCl_x$에서 Cl의 양이 줄어들고 Pt가 담체인 $SnO_2$속으로 이동되고 있는 것을 보여주었다. 이것이 가스 감지도를 향상시키는 것으로 나타났다. Pt/SnO$_2$시편이 있는 반응기에 $N_2$가스 중에 0.5% $H_2$ 가스를 30 sccm으로 계속 흘려주었을 때 $SnO_2$의 전기 저항은 포화가 이루어 졌으나 $SnO_2$상에 수소 가스의 흡착은 계속되었다. 이는 표면 상태(surface state)가 포화된다는 것을 의미한다. 14 ppm $H_2$가스에 대하여 $300^{\circ}C$에서 81%%의 가스 감지도를 보여주었다.

• 대기
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• 제21권3호
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• pp.229-241
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• 2011

The continuous urbanizations by a rapid economic growth and a steady increase in population are expected to have a possible impact on meteorology in the downwind region. Long-term (1972~2007) trends of precipitation have been examined in the mid-Korean peninsula for the westerly condition only, along with the sensitivity simulations for a golden day (11 February 2009). During the long-term period, both precipitation amount (PA) and frequency (PF) in the downwind region (Chuncheon, Wonju, Hongcheon) of urban area significantly increased for the westerly and light precipitation ($PA{\leq}1mm\;d^{-1}$) cases, whereas PA and PF in the mountainous region (Daegwallyeong) decreased. The enhancement ratio of PA and PF for the downwind region vs. urban region remarkably increased, which implies a possible urbanization effect on downwind precipitation. In addition, the WRF simulation applied for one golden day demonstrates enhanced updraft and its associated convergence in the downwind area (about 60 km), leading to an increase in the cloud mixing ratio. The sensitivity experiments with the change in surface roughness demonstrates a slight increase in cloud water mixing ratio but a negligible effect on precipitation in the upwind region, whereas those with the change in heat source represents the distinctive convergence and its associated updraft in the downwind region but a decrease in liquid water, which may be attributable to the evaporation of cloud droplet by atmospheric heating induced by an increase in an anthropogenic heat. In spite of limitations in the observation-based analysis and one-day simulation, the current result could provide an evidence of the effect of urbanization on the light precipitation in the downwind region.

• 대기
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• 제23권3호
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• pp.321-329
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• 2013

This study examines the effect of aerosols on the vertical invigoration of continental stratiform clouds, using a dataset of Atmospheric Radiation Measurement (ARM) Intensive Operational Period (IOP, March 2000) at the Southern Great Plains (SGP) site. To provide further support to our observation-based findings, the weather research and forecasting (WRF) sensitivity simulations with changing cloud condensation nuclei (CCN) concentrations have been carried out for the golden episode over SGP. First, cross correlation between observed aerosol scattering coefficient and cloud liquid water path (LWP) with a 160-minutes lag is the highest of r = 0.83 for the selected episode, which may be attributable to cloud vertical invigoration induced by an increase in aerosol loading. Modeled cloud fractions in a control run are well matched with the observation in the perspective of cloud morphology and lasting period. It is also found through a simple sensitivity with a change in CCN that aerosol invigoration (AIV) effect on stratiform cloud organization is attributable to a change in the cloud microphysics as well as dynamics such as the corresponding modification of cloud number concentrations, drop size, and latent heating rate, etc. This study suggests a possible cloud vertical invigoration even in the continental stratiform clouds due to aerosol enhancement in spite of a limited analysis based on a few observed continental cloud cases.

• 한국물환경학회지
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• 제28권3호
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• pp.444-452
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• 2012

This study aims at assessing vulnerability of water quality and aquatic ecosystem to climate change by using proxy variables. Vulnerability to climate change is defined as a function of exposure to climate, sensitivity, and adaptive capacity. Detailed proxy variables were selected considering availability and then standardized by re-scaling concept. After adequate weights were assigned to standardized proxy variables by Delphi technique, vulnerability index was calculated. As results, vulnerability of adjacent regions to coastal areas include water quality and aquatic ecosystem is relatively higher than that of inland areas, and especially adjacent region to the western and southeast seas, and Jeju show high vulnerabilities. Vulnerability in the future was performed based on A1B scenario (IPCC, 2000). Temporally, the increase of vulnerability from 2050s to 2100s may be larger than the increase from 2000s to 2050s. Because vulnerability index was estimated through the relationship among various proxy variables, it is important to consider characteristics of local region with measurements and policies for reduction of sensitivity and enhancement of adaptive capacity on climate change. This study is expected to be useful in planning adaptation measures and selecting priority to the policy on climate change.

• 국제초고층학회논문집
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• 제3권2호
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• pp.99-106
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• 2014

This paper presents the determination of the structural system of the Changsha IFC T1 tower with 452 m in architectural height and 440.45 m in structural height. Sensitivity analyses are carried out by varying the location of belt trusses and outriggers. The enhancement of seismic capacity of the outer frame by reasonably adjusting the column size is confirmed based on parametric studies. The results from construction simulation including the non-load effect of structures demonstrate that the deformation of vertical members has little effect on the load-bearing capacity of belt trusses and outriggers. The elastoplastic time-history analysis shows that the overall structure under rare earthquake load remains in an elastic state. The influence of the frame shear ratio and frame overturning moment ratio on the proposed model and equivalent mega column model is investigated. It is found that the frame overturning moment ratio is more applicable for judging the resistance of the outer frame against lateral loads. Comparison is made on the variation of these two effects between a classical frame-core tube-outrigger structure and a structure with diagonal braces between super columns under rare earthquakes. The results indicate that plasticity development of the top core cube of the braced structure may be significantly improved.

• 센서학회지
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• 제12권5호
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• pp.218-224
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• 2003

플라즈마, $H_2$와 $H_2$/플라즈마 공정에 의해 수소 처리시킨 n-채널 다결정실리콘 박막트랜지스터(TFT)를 제작하였다. 전압 바이어스 스트레스로 게이트 산화막에 유기된 감지 특성들을 분석하였다. 수소 처리시킨 소자에서 전기적 스트레스 조건에 의해 야기된 인자적 감지 특성들은 드레인전류, 문턱전압(Vth), 문턱전압 아래기울기(S), 그리고 최대 전달 컨덕턴스(Gm) 값을 측정하여 조사하였다. 분석 결과로서, 수소화 처리시킨 n-채널 다결정 실리콘 박막 트랜지스터에서 감지된 열화특성은 다결정실리콘/산화막의 계면과 다결정 실리콘의 그레인 경계에서 실리콘-수소(Si-H) 본드의 해리에 의한 현수 본드의 증가가 원인이 되었다. 게이트 산화막내 트랩의 생성은 채널 영역에서 게이트 산화막 속으로 핫 전자 주입에 의해 야기되었다.

• 센서학회지
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• 제29권6호
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• pp.388-393
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• 2020

In this study, a PbS quantum dots (QDs)-based H₂ gas sensor with a Pd electrode was proposed. QDs have a size of several nanometers, and they can exhibit a high surface area when forming a thin film. In particular, the NH₂ present in the ligand of PbS QDs and H₂ gas are combined to form NH₃⁺, subsequently the electrical characteristics of the QDs change. In addition to the resistance change owing to the reaction between Pd and H₂ gas, the resistance change owing to the reaction between the NH₂ of PbS QDs and H₂ gas increases the current signal at the sensor output, which can produce a high output signal for the same concentration of H₂ gas. Using the XRD and absorbance properties, the synthesis and particle size of the synthesized PbS QDs were analyzed. Using PbS QDs, the sensitivity was significantly improved by 44%. In addition, the proposed H₂ gas sensor has high selectivity because it has low reactivity with heterogeneous gases such as C₂H₂, CO₂, and CH₄.