세계 최초 드롭형 거푸집 공법 개발을 통한 시공생산성 향상 및 환경친화적 공사수행 사례

김태호,김욱종,이도범,김한기,Kim, Tae-Ho,Kim, Uk-Jong,Lee, Do-Beom,Kim, Han-Gi 한국건설관리학회 2010 건설관리 : 한국건설관리학회 학회지 Vol.11 No.4

공기 포일 베어링으로 지지되는 터보 압축기의 공력 불안정성이 로터에 미치는 진동 영향

김태호,이용복,김창호,이남수,김광호,신유환,Kim, Tae-Ho,Lee, Yong-Bok,Kim, Chang-Ho,Lee, Nam-Soo,Kim, Kwang-Ho,Shin, You-Hwan 한국유체기계학회 2003 한국유체기계학회 논문집 Vol.6 No.2

An oil-free turbo-compressor supported by compliant foil bearings which remove oil-contamination by elimination of a conventional ball bearing and oil lubrication systems is presented. Turbo-compressor makes two individual air compressions with two impellers at a operating speed of 39,000 rpm. In this study, the rotordynamic effects caused by aerodynamic instability were investigated with variable mass flow rates. Correlations between frequencies of pressure fluctuation in two diffusers and those of excitation forces on rotor were clearly observed in an aerodynamic unsteady region. Thus, these results show that it is beneficial to design high-speed rotating turbomachinery by considering coupling effect between aerodynamic instability and rotordynamic force.

Portfolio분석을 이용한 서울시 역세권 지하철 연계수단간 유형분류 연구 - 서울시 25개 행정구역을 중심으로 -

김태호,박준태,손상호,박제진,Kim, Tae-Ho,Park, Jun-Tae,Son, Sang-Ho,Park, Je-Jin 대한토목학회 2015 대한토목학회논문집 Vol.35 No.6

본 연구에서는 서울시 지하철 분담률의 지역적 차이에 대한 원인분석을 통하여 올바른 정책적 수단을 찾기 위한 모형을 개발하고자 한다. 이를 통해 가장 영향력 있는 두 개의 변수를 찾아내어 Portfolio 분석을 실시하였다. 분석결과, 첫째, 지하철 분담률에 영향을 미치는 요인은 크게 역세권 요인과 마을버스 요인으로 나타났다. 이는 줄어들고 있는 지하철 분담률을 개선하기 위해서 역세권지역의 확장, 역사수 증설, 마을버스 노선수의 증대가 요구됨을 의미한다. 둘째, Portfolio 분석결과 지하철 연계 강화를 위한 개선유형은 역세권 중심 개선과 마을버스 중심 개선지역으로 구분되었다. 역세권 중심 개선지역은 강북구, 서대문구, 금천구, 관악구로 나타났고, 송파구와 중구는 마을버스 중심 개선지역으로 나타났다. 따라서 향후 지하철 분담률 향상을 위해서는 두 가지 측면의 주요 요인을 유형별(지역)로 적절히 고려하는 대중교통 관련 정책을 제시하는 것이 필요할 것으로 판단된다. This article aims to develop model for the right policy Tools available from the cause analysis regarding the regional differences of subway modal split in Seoul metropolitan area. This allows two major factors of the most influential subway modal split to be proved and Portfolio Analysis is conducted. The results are as follows. Firstly, the two primary factors affecting subway modal split were shown as subway adjacent area and local line bus. It signifies that expansion of subway adjacent area, establishing the number of the subway stations and increase of local line bus are required in order to improve a diminishing subway modal split. Following that, pattern of the improvement to strengthen better subway connections are classified according to the two areas which are Concentration Area of Improvement in Subway Station Area (CAISSA) and Concentration Area of Improvement in Local Bus (CAILB). Our study revealed that Ganbukgu, Seodaemungu, Geumcheongu, and Gwanakgu were selected as the area of CAILB and Songpagu, and Junggu were selected as the area of CAISSA. As all things are considered, transportation policy makers should be taken into account in the two main factors driven by our study according to types in order to enhance the future subway share proportion.

고상반응법과 착체중합법으로 합성된 SrAl₂O₄: Eu²⁺, Dy³⁺ 축광성 형광체의 특성 및 열적 안정성 평가

김태호,황해진,김진호,황광택,한규성,Kim, Tae-Ho,Hwang, Hae-Jin,Kim, Jin-Ho,Hwang, Kwang-Taek,Han, Kyu-Sung 한국결정성장학회 2016 韓國結晶成長學會誌 Vol.26 No.5

Characteristics of $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ phosphorescent phosphors synthesized by solid state reaction and polymerized complex method were comparatively analyzed. In order to evaluate thermal stability of $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ phosphorescent phosphors at high temperature, phosphorescent properties of $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ were investigated with thermal treatment at $1250^{\circ}C$ under reducing atmosphere, which was the general heat treatment conditions for ceramic manufacturing process. The phosphorescent properties of thermally treated $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ phosphors synthesized by solid state reaction and polymerized complex method were investigated. The crystal structure and crystallite size were observed through XRD analysis. Microstructure and particle size of thermally treated $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ phosphors were analyzed by SEM and PSA. Photoluminescence and afterglow characteristics of thermally treated $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ phosphorescent phosphors were measured by spectrofluorometer. 고상반응법과 착체중합법 두 합성법에 의해 합성된 $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ 축광성 형광체 분말의 특성을 비교 분석하였다. 열적 안정성을 평가하기 위해 산업 도자 제조공정에서 사용되는 열처리 조건($1250^{\circ}C$, 1시간 유지, LPG 환원분위기)을 적용하여 고상반응법과 착체중합법으로 합성된 $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ 축광성 형광체 분말의 열처리 전후의 축광 특성변화를 관찰하였다. 두 합성법으로 합성된 분말과 고온 열처리 전후의 분말은 XRD 분석을 통해 결정구조 및 결정자 크기변화를 확인하였고, SEM과 PSA 분석을 이용하여 미세구조 및 입자 크기 변화를 관찰하였다. Spectrofluorometer 분석을 통해 $SrAl_2O_4:Eu^{2+}$, $Dy^{3+}$ 축광성 형광체의 여기 및 발광 특성, 장잔광 특성 변화를 확인하였다.

요통환자에 대한 PNF 적용 효과에 관한 고찰

김태호,김은정,정재민,윤영조,한진태,Kim, Tae-Ho,Kim, Eun-Jung,Jung, Jae-Min,Yoon, Young-Jo,Han, Jin-Tae 대한고유수용성신경근촉진법학회 2008 PNF and Movement Vol.6 No.1

Purpose : When the pliability of the Lumbar is degraded, the kinesiology function undergoes an influence and it receives an overload. Finally, it is connected with a Lumbar muscular injury. When it does the regular exercise treatment the lumbago patient the balance and function of changeover are improved. The purpose of this study is to review of effect of the PNF application for lumbago patient Methods : By using internet, we research the PubMed, Science Direct, KISS, DBpia and the article on the effect of PNF. We selected the article between 1970 and 2007. Key words were low back pain, lumbago, PNF. Results : PNF is a therapeutic exercise for central nervous system(CNS) patient and the peripheral nervous system(PNS) patient and it is widely applied from sports medicine in the last. According to research of the Jung Young Jo(2007) and Han Kou Soo(2002), PNF technique improves the pain and a condition of the lumbago patient. And the affection balanced change and dynamic balance change and spontaneous movable scope are improved. And it improved to daily life activity. According to research of Moore and Hutton(1980), Lee Kyoung Hye(1999), PNF stretching where it is one of muscular relaxation is good in lumbar muscle fascia ache solutions, and PNF stretching that muscle is relaxed and increases ROM by Reflective system of the vertebra. These researches is relation all each other. it have appeared many report of research about Pliability, muscular power, balance, mobility improve ADL movement of attendance ability and functional action improved excise therapy put effect about lumbago patient recently, it have appeared research about therapy of lumbago patient through PNF. But PNF technique is not application about lumbago patient in clinic, therefore also it is not enough for case study about this therapy. Conclusion : PNF improve combination operation of muscle, inconvenience decrease from daily life activity, ROM(range of movement) of lumbar is increase and Lumbago reduce. So we suggest that PNF will be applies on the lumbago patient and must do a many research.

콘크리트 양생을 위한 열차진동 평가사례

김태호,김욱종,김효락,Kim, Tae-Ho,Kim, Ook-Jong,Kim, Hyo-Rak 한국공간구조학회 2011 한국공간구조학회지 Vol.11 No.2

고속 터보기계용 공기 포일 저널 베어링의 신뢰성에 관한 연구

김태호,이용복,김창호,이남수,Kim, Tae-Ho,Lee, Yong-Bok,Kim, Chang-Ho,Lee, Nam-Soo 한국유체기계학회 2003 한국유체기계학회 논문집 Vol.6 No.2

This paper describes reliability characteristics of an air foil journal bearing for high-speed turbomachinery at a room temperature. To verify the reliability of air foil journal bearing, lift-off characteristics, load carrying capacity, and 10,000 cycle start-stop test were performed with a motor-driven test rig. A lift-off test shows the relationship between the rotating speed of the shaft and the frictional torque with bearing surface. About a load-carrying capacity, the tested air foil journal bearing produced a load capacity of 500N at an operating speed of 15,000rpm, which is compared with results of numerical analysis and empirical coefficients. Finally, the trends in change of start torque, stop torque, and bearing temperature were shown during a 10,000-cycle start-stop test of an air foil journal bearing. We found that an air foil bearing performs well, as a supported bearing for the high-speed turbocompressor.

비스무스와 지르코늄 첨가를 통한 세리아계 친환경 노란색 안료 특성에 관한 연구

김태호,황해진,김진호,황광택,한규성,Kim, Tae-Ho,Hwang, Hae-Jin,Kim, Jin-Ho,Hwang, Kwang-Taek,Han, Kyu-Sung 한국결정성장학회 2015 한국결정성장학회지 Vol.25 No.4

무기안료는 우수한 열적, 화학적 안정성으로 인해 페인트, 고화도 세라믹 잉크, 아트 타일, 건물의 외장재 등의 다양한 응용 분야에 적용될 수 있어 큰 관심을 받고 있다. 기존에는 $PbCrO_4$, CdS, CdSe 등의 조성이 노란색 무기 안료로 널리 사용되어 왔으나 Cd, Cr, Pb, Se 같은 유해물질을 포함하고 있어 최근에는 사용에 제한되고 있다. 따라서 본 연구에서는 ceria 기반의 조성을 이용하여 고상법으로 친환경 노란색 무기안료를 합성하였다. XRD와 SEM을 통해 합성된 $Ce_{1-x}Zr_xBi_yO_{2-y/2}$ 노란색 무기안료의 결정구조와 형상을 확인하였고, UV-vis. spectrophotometer와 CIE $L^*a^*b^*$ 분석으로 Zr과 Bi함량에 따른 노란색 무기안료의 발색 특성 변화를 확인하였다. 노란색 무기안료의 결정구조는 주로 하소온도의 변화에 의존하는 것으로 확인되었고, 발색 특성과 흡수단은 하소온도와 Zr, Bi 함량이 모두 영향을 미치는 것으로 나타났다. 결과적으로 합성된 모든 무기안료는 자외선과 500 nm 이하의 가시광선을 효율적으로 흡수하였고, $Ce_{0.44}Zr_{0.36}Bi_{0.20}O_{0.19}$(x = 0.36, y = 0.20) 조성의 무기안료에서 가장 선명한 노란색 색조를 확인할 수 있었다. Inorganic pigments have been received a great attention for various applications including paint, glazed ceramic ink, art tile, and building exterior due to their excellent thermal and chemical stability. Traditionally, the compositions of $PbCrO_4$, CdS and CdSe have been widely used as a yellow inorganic pigment. However, the use of these compositions has been restricted in recent years, because they contain harmful elements such as Cd, Cr, Pb and Se. In this study, new environment-friendly ceria-based pigment was synthesized using solid state reaction. Crystal structure and morphology of the obtained $Ce_{1-x}Zr_xBi_yO_{2-y/2}$ yellow pigment were analyzed using XRD and SEM, respectively. Substitutional effect of Zr and Bi on the pigment color was analyzed using UV-vis. spectrophotometer and CIE $L^*a^*b^*$ analysis. The crystal structure of the obtained pigments was dependent on the calcination temperature. The color characteristics and absorption band of the pigments were dependent on the calcination temperature and Zr, Bi contents. As a result, all the obtained yellow pigments showed the effective absorption ranged from ultraviolet to visible light, and $Ce_{0.44}Zr_{0.36}Bi_{0.20}O_{0.19}$ (x = 0.36, y = 0.20) pigment showed the most brilliant yellow color.

착체중합법을 이용한 SrAl₂O₄: Eu²⁺, Dy³⁺ 축광성 형광체의 합성

김태호,황해진,김진호,황광택,한규성,Kim, Tae-Ho,Hwang, Hae-Jin,Kim, Jin-Ho,Hwang, Kwang-Taek,Han, Kyu-Sung 한국재료학회 2016 한국재료학회지 Vol.26 No.10

$SrAl_2O_4$: $Eu^{2+}$ and $Dy^{3+}$ phosphorescent phosphors were synthesized using the polymerized complex method. Generally, phosphorescent phosphors synthesized by conventional solid state reaction show a micro-sized particle diameter; thus, this process is restricted to applications such as phosphorescent ink and paint. However, it is possible to synthesize homogeneous multi-component powders with fine particle diameter by wet process such as the polymerized complex method. The characteristics of $SrAl_2O_4$: $Eu^{2+}$ and $Dy^{3+}$ powders prepared by polymerized complex method with one and two step calcination processes were comparatively analyzed. Temperatures of organic material removal and crystallization were observed through TG-DTA analysis. The crystalline phase and crystallite size of the $SrAl_2O_4$: $Eu^{2+}$ and $Dy^{3+}$ phosphorescent phosphors were analyzed by XRD. Microstructures and afterglow characteristics of the $SrAl_2O_4$: $Eu^{2+}$ and $Dy^{3+}$ phosphors were measured by SEM and spectrofluorometry, respectively.

2D 어레이 다이오드 검출기를 통한 IMRT 계산선량의 정확성 평가 및 효용성 연구

김태호,오승종,김민주,정원균,정진범,김재성,김시용,서태석,Kim, Tae-Ho,Oh, Seung-Jong,Kim, Min-Joo,Jung, Won-Gyun,Chung, Jin-Beom,Kim, Jae-Sung,Kim, Si-Yong,Suh, Tae-Suk 한국의학물리학회 2011 의학물리 Vol.22 No.2

2D 어레이 다이오드 검출기를 이용하여 전립선과 두경부 IMRT 환자(전립선 2사례, 두경부 2사례)를 대상으로 선량계산 격자 크기(calculation grid size)에 따른 계산선량 정확성(dose calculation accuracy)을 평가했으며, 그 결과를 바탕으로 2D 어레이 다이오드가 IMRT 계산선량과 조사선량 검증에 적합한지 여부를 확인했다. 치료계획장치(treatment planning system, TPS)에서 제공되는 4종류의 격자 크기(1.25 mm, 2.5 mm, 5 mm, 10 mm) 별로 계산된 선량과 2D 어레이 다이오드 검출기를 이용하여 얻어진 측정선량을 감마 분석방법을 이용, 비교하는 방식으로 실험을 진행하였으며, 선량분포의 변화 범위에 따른 정확성 변화 또한 확인했다. 3 mm/3%의 평가기준(acceptance criteria)을 적용한 감마 분석방법에서는 10 mm를 제외한 격자 크기 별 평균 통과율(pass rate)에 뚜렷한 차이를 확인할 수 없었으나, 평가기준을 3 mm/3%, 2mm/2%, 1 mm/1%로 세밀하게 적용하였을 경우, 1.25 mm를 제외한 격자크기의 통과율이 각각 5%와 20%, 31.53% 감소하는 것을 확인할 수 있었다. 격자 크기에 따른 선량계산시간은 1.25, 2.5, 5, 10 mm 격자 크기에서 각각 11.5, 4.77, 2.95, 1.5 min 소비됐으며 격자 크기가 2배 증가할수록 선량계산시간은 약 1/2로 감소되는 결과를 확인할 수 있었다. 또한 저경사도영역(low gradient area)과 고경사도영역(high gradient area)을 구분하여 격자 크기영향을 평가하였으며, 격자 크기가 계산선량 정확성에 미치는 효과는 low gradient area보다 high gradient area에서 더 크게 작용한다는 결과를 확인했다. 본 연구의 결과를 종합해 봤을 때 2.5 mm의 격자 크기로 선량계산을 수행하는 것이 계산선량 정확성과 계산시간 면에서 적절한 것으로 여겨지며, high gradient area에 있어서는 가능한 세밀한 격자크기(1.25 mm)를 적용할 것이 권장된다. 또한 이상의 결과가 기존 연구의 이론 및 필름을 이용한 측정과 동일함을 고려해 봤을 때 2D 어레이 다이오드 검출기가 IMRT 계산선량과 조사선량 검증에 적합함을 확인할 수 있었다. In this study, we evaluated the effect of grid size on dose calculation accuracy using 2 head & neck and 2 prostate IMRT cases and based on this study's findings, we also evaluated the efficiency of a 2D diode array detector for IMRT quality assurance. Dose distributions of four IMRT plan data were calculated at four calculation grid sizes (1.25, 2.5, 5, and 10 mm) and the calculated dose distributions were compared with measured dose distributions using 2D diode array detector. Although there was no obvious difference in pass rate of gamma analysis with 3 mm/3% acceptance criteria for the others except 10 mm grid size, we found that the pass rates of 2.5, 5 and 10 mm grid size were decreased 5%, 20% and 31.53% respectively according to the application of the fine acceptance criteria, 3 mm/3%, 2 mm/2% and 1 mm/1%. The calculation time were about 11.5 min, 4.77 min, 2.95 min, and 11.5 min at 1.25, 2.5, 5, and 10 mm, respectively and as the grid size increased to double, the calculation time decreased about one-half. The grid size effect was observed more clearly in the high gradient area than the low gradient area. In conclusion, 2.5 mm grid size is considered acceptable for most IMRT plans but at least in the high gradient area, 1.25 mm grid size is required to accurately predict the dose distribution. These results are exactly same as the precious studies' results and theory. So we confirmed that 2D array diode detector was suitable for the IMRT QA.