우치에서 레진 침투법 및 불소 적용의 탈회 저항성 비교

이두영,김익환,송제선,김성오,손흥규,이제호,Lee, Doo-Young,Kim, Ik-Hwan,Song, Je Seon,Kim, Seong-Oh,Son, Heung Kyu,Lee, Jaeho 대한소아치과학회 2018 大韓小兒齒科學會誌 Vol.45 No.2

본 실험의 목적은 초기 우식 부위에 레진 침투법과 불소 적용 후 탈회 저항성을 비교하기 위함이다. 인공 우식을 유발한 시편을 대조군, 1.23% 산성불화인산염(Acidulated phosphate fluoride(APF))군, 레진 침투군으로 분류하고 각 재료를 적용 후 재탈회시켰다. 이후 공초점 레이저 현미경(Confocal Laser Scanning Microscope(CLSM))을 이용하여 탈회 깊이를 측정하였고 주사전자현미경(SEM)을 이용하여 법랑질 표면 거칠기를 관찰하였다. CLSM을 이용하여 탈회 깊이를 측정하였을 때 대조군, 1.23% 산성불화인산염군, $Icon^{(R)}$ caries infiltrant군 순으로 감소하였다. 탈회 깊이는 1.23% 산성불화인산염군, $Icon^{(R)}$ caries infiltrant군이 대조군에 비해서는 유의성 있는 차이를 보이지만 두 군 간의 차이가 없었다(p < 0.05). 표면거칠기는 대조군에서 매우 거칠고 표면이 불규칙한 양상을 보였고 1.23% 산성불화인산염군, $Icon^{(R)}$ caries infiltrant 군으로 갈수록 표면 거칠기와 불규칙성은 감소하였다. The aim of this study is to compare the differences of the demineralization resistance of resin infiltration and 1.23% acidulated phosphate fluoride in bovine teeth with artificial caries. We applied 1.23% Acidulated phosphate fluoride (APF) gel and $Icon^{(R)}$ caries infiltrant on the artificial bovine enamel carious lesion and then demineralized all samples. The depth of demineralization was measured by using Confocal Laser Scanning Microscope (CLSM) and observed the roughness and irregularity of the enamel was observed by Scanning Electron Microscope (SEM). In this experiment with demineralization resistance on smooth artificial carious lesion, less depth of demineralization, roughness, and irregularity of enamel was observed in APF gel and $Icon^{(R)}$ group than in the control group. There was no significant difference between the depth of demineralization of 1.23% APF gel and $Icon^{(R)}$ caries infiltrant group. However, resin infiltration is beneficial as less roughness and irregularity was observed on the enamel surface than when 1.23% APF gel is applied.

제어 방식에 따른 지열 히트펌프 시스템의 성능 시뮬레이션

이두영,최재호,민경천,손병후,Lee, Doo-Young,Choi, Jae-Ho,Min, Kyong-Chon,Sohn, Byonghu 대한기계학회 2016 대한기계학회 논문집. Transactions of the KSME. C, 산업기술과 혁신 Vol.4 No.1

지열 히트펌프 시스템에서 히트펌프 등 시스템 구성 요소의 에너지 소비량을 효율적으로 관리하면, 냉난방 성능을 더 높일 수 있다. 본 논문은 외기온도 제어 방식이 지열 시스템의 성능에 미치는 영향을 분석하였다. 또한 분석 결과를 현재 국내에서 주로 적용하는 제어 방식(Control-A)과 비교하였다. 이를 위해 상용 소프트웨어(TRNSYS 17)를 이용하여 가상 지열 시스템의 모델을 구축한 후, 시뮬레이션을 수행하였다. 외기 온도 제어 방식(Control-B)은 버퍼 탱크의 온도를 외기 온도에 따라 제어하기 때문에, 간절기 때 효과적이었다. 기존 제어 방식과 비교했을 때, 외기 온도 제어 방식은 히트펌프 전력 소비량을 7.7%(147 kWh 절감) 그리고 순환펌프 전력 소비량을 7.5%(28.1 kWh 절감) 줄일 수 있었다. Geothermal heat pump (GHP) systems have been proved to be one of the most efficient systems for heating and cooling in buildings. However, an optimal energy performance depends on a good control of the system components, including heat pumps and circulation pumps, which affect to the total energy consumption of system. This paper presents the simulation results of the heat pump performance for two different control schemes, i.e. constant setting temperature (Control-A) and variable setting temperatures (Control-B) in buffer tank. A dynamic simulation tool, TRNSYS 17, was used to model the entire system and to assess the performance of the system. Simulation results show that the Control-B, which controls the temperature in buffer tank with outdoor air temperature, is a effective way to reduce the energy consumptions in heat pump (7.7%) and circulation pump (7.5%).

이러닝 법제적 환경 검토를 통한 온라인 스마트러닝 전자학습법 대안

이두영(Doo young Lee),신지웅(Ji woong Shin) 전북대학교 법학전문대학원 학술지 편집위원회 2013 JEONBUK LAW JOURNAL Vol.4 No.1

본 논문은 최근 대학 교육에서 활발히 활용되고 있는 이러닝의 현위상을 분석하였다. 특히 정부의 이러닝 산업 발전 계획을 분석하여 실질적인 운영 방식에 있어서 이러닝 학습 모델의 한계점을 연구하고, 새로운 온라인 학습 모델을 제안한다. 온라인학습은 오프라인 학습의 시공간적 한계를 극복하였지만, 그 방식에 있어 오프라인의 정량적인 학습방식을 원용하고 있다는 점을 한계로 보고 이러닝 학습 효과 파악에 있어 정성적인 방법을 대안으로 제시한다. 온라인 학습모델에 웹 2.0 개념을 접목하여 기존의 이러닝 시스템에 개선을 유도한다. 따라서 이러닝 산업 발전 계획에서 의도하는 질적인 변화를 이루어 스마트러닝 시대에 적합한 모델을 구축할 수 있는 방안을 제시한다. This study focuses on condition of e-learning operation model in University. And suggests the better operation model based on Internet Architecture. Especially, Time Concept that using for attendance on e-learning class is have some side effect. So this study would applied Qualitative Concept on e-learning class. Question Based System, QBS is example model. QBS is that Learner participate a leading role in e-class, by making Question. these questions are shared with other students and refer to studing contents. Practically operating Qualitative Concept model QBS on university e-class, we can seek for the effectiveness of Qualitative e-learning model QBS.

영구자석동기발전기 풍력시스템의 하드웨어 시뮬레이터 개발

李斗榮(Doo-Young Lee),尹東珍(Dong-Jin Yun),鄭鍾圭(Jong-Kyou Jeong),梁承哲(Seung-Chul Yang),韓炳文(Byung-Moon Han),宋丞鎬(Seung-Ho Song) 대한전기학회 2008 전기학회논문지 Vol.57 No.6

This paper describes development of hardware simulator for the PMSG wind power system, which was designed considering wind characteristic, blade characteristic and blade inertia compensation. The simulator consists of three major parts, such as wind turbine model using induction motor, PMSG generator, converter-inverter set. and control system. The turbine simulator generates torque and speed signals for a specific wind turbine with respect to given wind speed. This torque and speed signals are scaled down to fit the input of 2kW PMSG. The PMSG-side converter operates to track the maximum power point, and the grid-side inverter controls the active and reactive power supplied to the grid. The operational feasibility was verified by computer simulations with PSCAD/EMTDC, and the implementation feasibility was confirmed through experimental works with a hardware set-up.

MMC STATCOM의 Valve 제작 및 시험

이두영(Doo-Young Lee),박용희(Yong-Hee Park),정종규(Jong-Kyou Jeong),김준성(June-Sung Kim) 전력전자학회 2015 전력전자학술대회 논문집 Vol.2015 No.07

1 MVA STATCOM의 실증운전 사례소개

이두영(Doo-Young Lee),정홍주(Hong-Ju Jung),김준성(June-Sung Kim) 전력전자학회 2013 전력전자학술대회 논문집 Vol.2013 No.7

출판정책의 이념과 출판산업 비전 참여정부의 ‘출판진흥계획’ 좌표를 중심으로

이두영(Lee Doo-Young) 한국출판학회 2004 한국출판학연구 Vol.0 No.46

This paper was written to focus on the following three viewpoints. The first viewpoint is to study the characteristics of the publishing policies and try to erect a thesis on reasonable and right procedures for the publishing policies through diversified and multiple-angled consideration. The second viewpoint is to analyze, consider and evaluate the publishing policies in terms of ideology, object, strategy, scope and subject, practicability and etc. published by the Participatory Government. In May 2003, the Participatory Government led by President Roh, Moo-hyun published a long-term publishing policy for the forthcoming five years, “Publishing and Printing Industry Promotion Plan”. The newly established “Publishing and Printing Promotion Law” is the basis of this publishing policy. This plan can be said as the first policy statement reveals a transition from regulation of publishing administration to upbringing of the publishing policies. This means Korea entered a new starting point of long-term and planned publishing policies. The third viewpoint is to suggest directions for the future publishing policies as in the followings. a) The basic ideology of publishing policies should increase the rights to enjoy publishing culture including the rights to read. Government should make an effort to bring up the publishing industry, improve the quality of publishing culture, and promote the reading habit with efficient measures and methods to achieve the ideology. b) Publishing Policies should be a future strategy to define new visions on the publishing concept and the publishing industry including the function and the role of the publishing industry and its business models to meet the digital and network era. Therefore, the publishing policies of the Participatory Government should make up for the concrete strategies considerably, such as the structure of publishing industry and the actual conditions of the employment, the changes of readers' values and buying patterns toward publishing and reading under the changing media surroundings, the measures to secure rights for the creative writers and publishers, the directions of publishing cooperation between North and South Korea aiming at the unification, and etc. c) Publishing policies should define the scopes and objects clearly and then, it should be developed to general publishing policies containing the system of cooperation and relation of strategies in the complicated correlations between cultural, industrial and commercial relations as a way of book development including the whole procedures of publishing activities from the copyright owners to readers. d) The Participatory Government should increase subsidies toward its publishing policies considerably.

Mathematical Analysis of the Web Structure in Orb-Weaving Spiders

Doo Young Lee(이두영),Gil Young Park(박길영),Yung Chul Park(박영철),Joo-Pil Kim(김주필) 한국거미연구소 2006 한국거미 Vol.22 No.2

  면적, 무게중심, 타원원주, 이심율 등의 수학 공식과 좌표를 이용함으로써 거미의 원형그물집의 구조적 특성을 분석했다. 그물의 하반부가 상반부보다 면적이 더 넓었으며, 원형그물의 무게중심의 Y-좌표 중심(0, 0) 보다 더 적었다. 방사선 거미줄의 수는 그물집의 상반부보다 하반부에서 더 많았다. 원주에 대한 면적의 비율은 그물집이 원형에 근접할수록 더 증가했다. 이러한 결과들은 좌표와 수학공식을 이용한 접근이 원형그물의 구조적 특징을 분석하는데 효율적으로 적용될 수 있다는 것을 의미한다.   We analyzed structural characteristics of spider orb-webs by applying coordinates and mathematical formulae of areas, centroids, elliptical circumferences and eccentricities. The results indicate that the lower-half regions of the orb-webs were larger than the upper-half regions. The results also show that Y-coordinates in the centroids of the orb-webs were smaller than those of the center (0, 0), that the number of radials greater in the lower-half regions than the upper-half regions, and that the ratio of area to circumference increased as the spider orb-webs come to resemble perfect circles. These results indicate that our approaches, based on coordinates and the mathematical formulae, are valuable for analyses of web characteristics of orb-weaving spiders.

증기터빈 저압 L-1단 블레이드-디스크 연성 진동 특성 분석

이두영(Lee, Doo-Young),배용채(Bae, Yong-Chae),김희수(Kim, Hee-Soo),이욱륜(Lee, Yook-Ryun),김두영(Kim, Doo-Young) 한국소음진동공학회 2010 한국소음진동공학회 논문집 Vol.20 No.1

This paper studies causes of the L-1 blade damage of a low pressure turbine, which was found during the scheduled maintenance, in 500 MW fossil power plants. Many failures of turbine blades are caused by the coupling of aerodynamic forcing with bladed-disk vibration characteristics. In this study the coupled vibration characteristics of the L-1 turbine bladed-disk in a fossil power plant is shown for the purpose of identifying the root cause of the damage and confirming equipment integrity. First, analytic and experimental modal analysis for the bladed-disk at zero rpm as well as a single blade were performed and analyzed in order to verify the finite element model, and then steady stresses, natural frequencies and corresponding mode shapes, dynamic stresses were calculated for the bladed-disk under operation. Centrifugal force and steady steam force were considered in calculation of steady and dynamic stress. The proximity of modes to sources of excitation was assessed by means of an interference diagram to examine resonances. In addition, fatigue analysis was done for the dangerous modes of operation by a local strain approach. It is expected that these dynamic characteristics will be used effectively to identify the root causes of blade failures and to perform prompt maintenance.

Mathematical Expression of Spider Orb-Webs : Ⅰ. Mathematical Analysis of Spirals and Radials in the Orb-Web of Araneus ventricosus (Araneidae) : 거미 원형그물의 수학적 표현 : Ⅰ. 왕거미속 원형 그물의 방사선과 나선 거미줄의 수학적 분석

Doo Young Lee(이두영),Gil Young Park(박길영),Yung Chul Park(박영철),Joo-Pil Kim(김주필) 한국거미연구소 2006 한국거미 Vol.22 No.2

좌표를 이용하여 거미의 원형그물의 나선과 방사선 거미줄의 방정식을 계산했다. 이를 위해 우선 타원식과 선형회귀 방정식을 이용해 원형그물의 나선과 방사선 거미줄의 수학적 공식을 유도했다. 그런 후 이 두 거미줄의 상호교차점의 좌표들을 구했다. 이 교차 좌표를 이용하여 거미그물을 재 구성해 실제의 그물집과 비교했을 때 통계적으로 중요한 차이가 없었다(t-검정, P>0.05). We formulated equations for the spirals and radials of the orb-webs of Araneus ventricosus by using geometric coordinates. Firstly, we deducted mathematical formulae for orb-web spirals and radials from ellipse and the linear regression equations. Then we calculated the coordinates of the intersection points between the spiral- and the radial equations. Artifical orb-webs were reconstructed based on the coordinates of the intersection points. When the reconstructed webs were compared with the real orb-webs, the two webs did not differ significantly (Paired t- test, P > 0.05).