바람과 대공간 구조물

김대영,김지영,김상대,Kim, Dae-Young,Kim, Ji-Young,Kim, Sang-Dae 한국공간구조학회 2005 한국공간구조학회지 Vol.5 No.1

비부식성 플럭스를 이용한 알루미늄 브레이징용 필러 소재의 저온 성형용 금속 복합 분말 개발

김대영,장하늘,윤대호,신윤호,김성호,최현주,Kim, Dae-Young,Jang, Ha-Neul,Yoon, Dae-Ho,Shin, Yun-Ho,Kim, Seong-Ho,Choi, Hyun-Joo 한국분말재료학회 (*구 분말야금학회) 2019 한국분말재료학회지 (KPMI) Vol.26 No.1

In aluminum brazing processes, corrosive flux, which is used in preventing oxidation, is currently raising environmental concerns because it generates many pollutants such as dioxin. The brazing process involving non-corrosive flux is known to encounter difficulties because the melting temperature of the flux is similar to that of the base material. In this study, a new brazing filler material is developed based on aluminum and non-corrosive flux composite powder. To minimize the interference of consolidation aluminum alloy powder by the flux, the flux is intentionally embedded in the aluminum alloy powder using a mechanical milling process. This study demonstrates that the morphology of the composite powder can be varied according to the mixing process, and this significantly affects the relative density and mechanical properties of the final filler samples.

인태아 상경신경절 발육에 관한 전자현미경적 연구

김대영,김백윤,윤재룡,Kim, Dae-Young,Kim, Baik-Yoon,Yoon, Jae-Rhyong 한국현미경학회 1998 Applied microscopy Vol.28 No.2

The development of the superior cervical ganglion was studied by electron microscopic method in human fetuses ranging from 40 mm to 260 mm of crown-rump length (10 to 30 weeks of gestational age). At 40 mm fetus, the superior cervical ganglion was composed of clusters of undifferentiated cell, primitive neuroblast, primitive supporting cell, and unmyelinated fibers. At 70mm fetus, the neuroblasts and their processes were ensheated by the bodies or processes of satellite cells. The cytoplasm of the neuroblast contained rough endoplasmic reticulum, mitochondria, Golgi complex, Nissl bodies and dense-cored vesicles. As the neuroblasts grew and differentiated dense-cored vesicles moved away from perikaryal cytoplasm into developing processes. Synaptic contacts between the cholinergic axon and dendrites of postganglionic neuron and a few axosomatic synapses were first observed at 70 mm fetus. At 90 mm fetus the superior cervical ganglion consisted of neuroblasts, satellite cells, granule-containing cells, and unmyelinated nerve fibers. The ganglion cells increased somewhat in numbers and size by 150 mm fetus. Further differentiation resulted in the formation of young ganglion cells, whose cytoplasm was densely filled with cell organelles. During next prenatal stage up to 260 mm fetus, the cytoplasm of the ganglion cells contained except for large pigment granules, all intracytoplasmic structures which were also found in mature superior cervical ganglion. A great number of synaptic contact zones between the cholinergic preganglionic axon and the dendrites of the postganglionic neuron were observed and a few axosomatic synapses were also observed. Two morphological types of the granule-containing cells in the superior cervical ganglion were first identified at 90 mm fetus. Type I granule-containing cell occurred in solitary, whereas type II tended to appeared in clusters near the blood capillaries. Synaptic contacts were first found on the solitary granule-containing cell at 150 mm fetus. Synaptic contacts between the soma of type I granule-containing cells and preganglionic axon termials were observed. In addition, synaptic junctions between the processes of the granule- containing cells and dendrites of postganglionic neuron were also observed from 150 mm fetus onward. In conclusion, superior cervical ganglion cells and granule-containing cells arise from a common undifferentiated cell precursor of neural crest . The granule-containg cells exhibit a local modulatory feedback system in the superior cervical ganglion and nay serve as interneurons between the preganglionic and postganglionic cells.

골수섬유증과 관련된 양측 수부의 괴저성 농피증

김대영,원영호,김성진,이승철,전인기 ( Dae Young Kim,Young Ho Won,Seong Jin Kim,Seung Chul Lee,Inn Ki Chun ) 대한피부과학회 1997 대한피부과학회지 Vol.35 No.4

Pyoderma gangrenosum is a rare neutrophilic dermatosis manifesting as painful pustules or bullae, which rapidly become necrotic to produce an ulceration. It is often associated with systemic disease, such as inflammatory bowel disease, rheumatoid arthritis, leukemia, but myelofibrosis is reported rarely for its underlying disease. The most common location is the lower extremities, and the pyoderma gangrenosum also occur infrequently on the hand and face. As in our case, bilateral involvement of the hands are rarely reported. We present a case of pyoderma gangrenosum that had developed on both hands in a 66 year old man who had macrocytic,anemia. A bone marrow biopsy revealed proliferation of fibroblasts and a dense reticulin network consistent with myelofibrosis, the association of which is very rare world wide. (Kor J Dermatol 1997;35(4): 809-813)

토사지반 EPB TBM의 굴진성능 및 커팅툴 마모량에 관한 실험장비 개발 및 기초연구

김대영,강한별,신영진,정재훈,이재원,Kim, Dae-Young,Kang, Han-Byul,Shin, Young Jin,Jung, Jae-Hoon,Lee, Jae-won 한국터널지하공간학회 2018 한국터널지하공간학회논문집 Vol.20 No.2

The excavation performance and the cutting tool wear prediction of shield TBM are very important issues for design and construction in TBM tunneling. For hard-rock TBMs, CSM and NTNU model have been widely used for prediction of disc cutter wear and penetration rate. But in case of soft-ground TBMs, the wear evaluation and the excavation performance have not been studied in details due to the complexity of the ground behavior and therefore few testing methods have been proposed. In this study, a new soil abrasion and penetration tester (SAPT) that simulates EPB TBM excavation process is introduced which overcomes the drawbacks of the previously developed soil abrasivity testers. Parametric tests for penetration rate, foam mixing ratio, foam concentration were conducted to evaluate influential parameters affecting TBM excavation and also ripper wear was measured in laboratory. The results of artificial soil specimen composed of 70% illite and 30% silica sand showed TBM additives such as foam play a key role in terms of excavation and tool wear. 쉴드 TBM 공사에서 굴진율 예측과 마모량 예측은 설계 및 시공 단계에서 공사비와 공기를 추정하는데 매우 중요한 요소이다. 암반지반용 TBM의 경우 실험이나 축적된 현장 data를 기반으로 CSM 모델, NTNU 모델 등이 커터 마모량부터 굴진율 예측까지 널리 사용되고 있으나, 토사지반용 TBM은 지반의 복잡성과 정확한 실험방법의 부재로 인해 이를 정확하게 예측할 수 있는 모델이 없는 실정이다. 본 연구에서는 기존에 존재하는 토사지반용 TBM 실험장치들의 단점을 개선하여 TBM 굴착과정을 모사한 실험 장치(Soil Abrasivity Penetration Test, SAPT)를 개발하였다. 회전당 관입 깊이, RPM, 첨가재(foam) 배합비 및 농도 등의 TBM 굴진에 영향을 미치는 주요 변수들에 대한 시험을 실시하여 추력, 토크 등의 변화를 살펴보고 마모량을 측정하였다. 모래(규사) 70%와 점토(일라이트) 30%로 조성된 인공시료에 대한 실험 결과 foam 배합비가 굴진성능과 마모량에 주요한 영향을 끼치는 것으로 나타났다.

해수의 영향에 따른 이수식 TBM의 슬러리 관리를 위한 기초적 연구

김대영,이재원,정재훈,강한별,지성현,Kim, Dae-Young,Lee, Jae-won,Jung, Jae-Hoon,Kang, Han-Byul,Jee, Sung-Hyun 한국터널지하공간학회 2017 한국터널지하공간학회논문집 Vol.19 No.3

벤토나이트는 물과 접촉하면 팽창하고 점성을 발휘하는 성질이 있어 일반적으로 차수가 필요한 토목공사에 많이 활용되고 있다. 이수식 TBM에서는 이와 같은 성질을 활용하여 가압된 슬러리로 불투수성 막을 형성하고 굴착벽면의 붕괴를 방지하는 동시에 굴착된 버력을 운송하며 굴착을 수행한다. 하지만 벤토나이트는 해수와 접촉할 경우 팽창성이 저하되어 그 성질을 발휘하지 못하는 문제가 있다. 이는 해수 조건에서 이수식 TBM으로 터널을 굴착할 시 지하수 유입 증가로 인한 굴착 안정성 및 버력 배출에 문제를 초래할 수 있다. 본 연구에서는 이수식 TBM으로 터널을 굴착 시 해수의 유입으로 인한 슬러리의 상태변화를 살펴보고 이에 대응하기 위한 슬러리 관리방안을 제시 하였다. 이를 위해 현장에서 적용된 슬러리 품질관리 기준을 바탕으로 실내 시험을 수행하였으며, 해수의 영향이 있는 현장에 적용 할 수 있는 방안을 제시하였다. Bentonite swells when it comes into contact with water and makes it a viscous fluid. Thus it is widely used in civil engineering works for waterproofing. Utilizing the properties of bentonite, the slurry shield TBM supports excavated face with pressurized slurry as well as transporting excavated muck. When bentonite is in contact with seawater, due to the change of double layer thickness, its expandability and viscosity are lowered. This may cause problems for excavation stability and muck discharge due to the increase of sea water inflow when Slurry TBM is used under sea water conditions. In this study, the change of slurry condition caused by the inflow of sea water during tunnel excavation with Slurry TBM was investigated and a slurry management guideline was proposed. For this purpose, a laboratory test was carried out based on the slurry management criterions applied in the field, and a method applicable to the field where sea water is affected has been proposed.

주 조절점 핸들링이 편마비 환자의 한발서기 자세적응에 미치는 영향 - 보바스의 신경발달치료 중심 -

김대영,Kim, Dae-Young 대한물리치료과학회 2001 대한물리치료과학회지 Vol.8 No.2

This study is aimed at diagnosing transmutation aspect with the respective of hemiplegia patient's static adaptation of posture which is influenced by anti-gravity excercise, center of gravity shifting movement and segmental movement adaption of the legs and arms by key-point control in the process of Bobatli's treatment approach. The patients for the investigation of this study were selected as a total 17 patients who were doing the physical-therapy in Tae-gu Rehabilitation Center, and diagnosed as hemiplegia patients by Rehabilitation Medicine department in Kyung-buk University hospital. And also, there investigated into temporal transition that keep the attitude with one-leg standing on the ground concerning static attitude adaption on the basis of the before of anti-gravity movement and the after of 4-weeks movement. The findings of this study were as follows: With the respective the time to keep standing pose by one-leg at static attitude transmutation, affected side showed meaningful differences as a l.86/sec, 2.62/sec at 4 weeks later considering the before and after of this experiment.(p<0.01), non-affected side at the aspect of attitude keeping time, but there didn't showed meaningful differences statistically.

UAM 효과 평가를 위한 현장실험 및 정량적 2차원 수치해석기법 개발에 관한 연구

김대영,이홍성,천병식,정종주,Kim, Dae-Young,Lee, Hong-Sung,Chun, Byung-Sik,Jung, Jong-Ju 한국터널지하공간학회 2009 한국터널지하공간학회논문집 Vol.11 No.1

UAM(Umbrella Arch Method)의 효과 및 역학적 보강메커니즘에 대한 연구는 국내외에서 수치해석 및 실험 등을 통하여 상당한 진척이 이루어졌으나 실제 설계 및 적용에 있어서는 아직도 3차원 해석의 해석시간과 복잡성 등의 제약 때문에 UAM의 보강영역과 지반과의 환산물성을 이용하는 정량적이지 못한 2차원해석이 주로 사용되고 있다. 이러한 이유로 합리적, 이론적, 정량적이면서도 손쉽게 수행할 수 있는 설계 및 해석기법이 요구되고 있다. 본 연구에서는 UAM의 보강효과가 미치는 범위를 파악하고 그라우팅 전 후의 강관저변지반 물성변화를 파악하기 위하여 연직방향의 UAM 현장실험 및 실내시험을 수행하였다. 풍화토, 풍화암 지반에 UAM 적용시 그라우트의 주입에 의한 주변지반의 물성치 증가는 미미하며, 강관외부와 천공구경 사이의 공간 및 강관내부에 형성된 시멘트구근과 강관으 강성만이 지반보강 효과에 기여한다는 것을 확인하였다. 이러한 결과와 내공변위제어법(CCM; Convergence Confinement Method) 개념을 바탕으로, 2차원 축대칭해석을 실시하여 막장효과, UAM효과와 지보재효과를 종단변위곡선(LDP)으로 나타내었다. 또한, 2차원 평면변형률 해석시 UAM의 지보효과를 내압의 크기로 변환하여 이를 고려하는 하중분담법을 제안하였다. 이 방법과 기존의 등가환산물성을 적용하는 해석을 비교한 결과, 지반조건, 터널의 심도 및 크기, 강관조건, 초기응력상태 등에 따라 차이가 있지만, 기존의 해석방법에서의 변위량이 새로운 방법에 비해 더 크게 발생하는 것으로 나타나, UAM의 종방향 빔 지지효과를 제대로 평가하지 못하는 것으로 나타났다. Considerable advance has been made on research on effect of steel pipe Umbrella Arch Method (UAM) and mechanical reinforcement mechanism through numerical analyses and experiments. Due to long analysis time of three-dimensional analysis and its complexity, un-quantitative two-dimensional analysis is dominantly used in the design and application, where equivalent material properties of UAM reinforced area and ground are used, For this reason, development of reasonable, theoretical, quantitative and easy to use design and analysis method is required. In this study, both field UAM tests and laboratory tests were performed in the residual soil to highly weathered rock; field tests to observe the range of reinforcement, and laboratory tests to investigate the change of material properties between prior to and after UAM reinforcement. It has been observed that the increase in material property of neighboring ground is negligible, and that only stiffness of steel pipe and cement column formed inside the steel pipe and the gap between steel pipe and borehole contributes to ground reinforcement. Based on these results and concept of Convergence Confinement Method (CCM), two dimensional axisymmetric analyses have been performed to obtain the longitudinal displacement profile (LDP) corresponding to arching effect of tunnel face, UAM effect and effect of supports. In addition, modified load distribution method in two dimensional plane-strain analysis has been suggested, in which effect of UAM is transformed to internal pressure and modified load distribution ratios are suggested. Comparison between the modified method and conventional method shows that larger displacement occur in the conventional method than that in the modified method although it may be different depending on ground condition, depth and size of tunnel, types of steel pipe and initial stress state. Consequently, it can be concluded that the effect of UAM as a beam in a longitudinal direction is not considered properly in the conventional method.

한국산(韓國産) 활엽수재(闊葉樹材) 천공판(穿孔板)의 미세형태(微細形態)에 관(關)한 연구(硏究) (II) - 천공판(穿孔板)의 구조(構造) -

김대영,이원용,Kim, Dae-Young,Lee, Won-Yong 강원대학교 산림과학연구소 1997 Journal of Forest Science Vol.13 No.-

우리나라산(産) 활엽수재 25과(科)45속(屬)78종(種)의 수종에 대하여 천공을 이루고 있는 구조를 주사전자현미경(SEM)을 사용하여 3차원적(次元的) 형태를 관찰하고, 이들의 미세한 천공구조의 본질을 조사하여 과(科), 속(屬), 종별(種別)로 고유의 특징을 구명하기 위하여 본 연구를 실시 하였으며 천공의 분류는 단천공(單穿孔), 계단천공(階段穿孔) 및 다공천공(多孔穿孔)(계단천공(階段穿孔) 이외의 다공천공(多孔穿孔))의 3가지로 구분하고 이것을 기초로하여 (1) 단천공(單穿孔)만을 갖는 수종(60종), (2) 계단천공(階段穿孔)만을 갖는 수종(5종), (3) 단천공(單穿孔)과 계단천공(階段穿孔)을 갖는 수종(4종), (4) 단천공(單穿孔)과 다공천공(多孔穿孔)을 갖는 수종(2종), (5) 계단천공(階段穿孔)과 다공천공(多孔穿孔)을 갖는 수종(5종), (6) 단천공(單穿孔), 계단천공(階段穿孔) 및 다공천공(多孔穿孔)을 갖는 수종(2종)의 6개의 그룹으로 분류 하였다. 그 결과 Betulaceae에 속하는 수종은 대부분이 계단천공(階段穿孔)을 나타내고 있으나 개서어나무에서는 단천공(單穿孔)이 출현하는 특징이 있으며, Fagaceae의 갈참나무에서는 단천공(單穿孔)의 천공연(穿孔緣)의 주연에 돌기물이 발생된 vesture천공이 관찰 되었다. 또한 계단천공(階段穿孔)의 상하의 bar가 서로 일치되고 있지않은 mismatching perforation plate가 물갬나무와 물오리나무에서 관찰되었으며 또한 계단천공의 bar사이에 벽물질이 남아 일부 또는 전부가 막혀 있거나 microfibrillar 모양의 substructure가 물박달나무와 계수나무에서 발견되었다. Perforation plate was observed in 78 species(45 genera, 25 families) of Korean native hardwoods using SEM and it was divided into three types, i.e., simple, scalariform and multiple perforation plates, Based on occurance of these types, the species examined were classfied into the following six groups : (1) 60species(35 genera, 21 families) having exclusively simple perforation, (2) 5 species(2 genera, 1 families) having exclusively scalariform perforation plates, (3) 4 species(4 genera, 3 families) having simple and scalariform perforation plates, (4) 2 species(2 genera, 1 families) having simple and multiple perforation plates, (5) 5 species(3 genera, 3 families) having scalariform and multiple perforation plates and (6) 2 species(2 genera, 2 families) having simple, scalariform and multiple perforation plates. Mismatching perforation plates were found in two species of Betulaceae, Alnus hirsuta var. sibirica and Alnus hirsuta and peculiar substructure between the bars of the scalariform perforation plate was observed in Betulaceae, Betula davurica and Cercidiphyllaceae, Cerdiphyllum japonicum and the vestured perforation plate was found in Quercus aliena.

카오스 암호를 이용한 개선된 암호화 웹 메일 시스템의 설계와 구현

김대영,김태식,Kim Dae-Young,Kim Tae-Sik 한국정보처리학회 2006 정보처리학회논문지D Vol.13 No.3

스트림 암호 시스템을 중심으로 한 카오스 암호 시스템은 원문의 길이가 클수록 암복호화 및 송수신 속도가 떨어지는 단점을 보여왔다. 본 연구에서는 원문의 길이가 길수록 기존의 웹 메일 시스템에 비해 더욱 우수한 성능을 보이고 있는 암호화 웹 메일 시스템을 설계 구현하였다. 암호화 웹 메일 시스템구현에서 키 수열 생성, 원문의 암복호화, 내외부 메일 뷰어 등을 개발하였고, 성능 평가 결과 암복호화 및 송수신 속도에서 우수한 것으로 평가되어 스트림 암호 시스템이 갖는 단점을 보완하였다고 할 수 있다. 앞으로 지속적인 응용 연구를 통해 암호화 기술을 기반으로 한 서버 시스템 보안 및 파일 보안, 인터넷 정보의 보안, 전자 상거래 시스템의 정보 보호 등 여러 분야에서 블록 암호 시스템을 대체할 수 있는 새로운 범용 암호 시스템으로 활용 할 수 있을 것으로 기대된다. A chaos cipher system that focuses on the stream cipher system has a demerit that the longer the text is, the slower the speed of the encryption and description and the transmission and reception. On this study, we designed the cipher web mail system showing much better capabilities than the existing web mail system as the text is longer. In the embodiment of the cipher web mail system, we developed the key stream, the encryption and description of the text and the inside and outside mail viewer and so on. After the efficiency test, it was valued high in the respect of the speed of the encryption and description and the transmission and reception. And it made up for the defect of the stream cipher system. We expect that we can use it through the persistent applied study in the server system security, the file security, the security of the internet information, the protection of the e-commerce system information and other fields based on the cipher technique as the wide use cipher system that can replace the block cipher system.