도로포장 하부재료에 대한 HISS 모델

柳知衡 慶一大學校 1997 論文集 Vol.14 No.2

포장 구조체는 반복되는 탄성 거동에 의하여 아스팔트층의 저면에 과도한 인장 변형율에 의한 피로 균열이 발생하고, 소성 거동으로 인하여 소성 변형이 누적되어 바퀴자욱 패임이 발생하여 구조적 능력을 상실하게 된다. 아스팔트 콘크리트 포장구조체의 이러한 거동을 해석하고 이를 설계에 적용하기 위해서는 적절한 구성방정식이 사용되어야 한다. C. S. Desai는 보다 간편하고 개선된 탄소성해석을 위한 구성방정식인 HISS(hierachical single surface) 모델을 제안, 개발하였다. 이 모델은 기본 구조에 요구되는 거동에 따른 parameter를 간단히 추가시키는 계층적 구조로 되어 있으며, 일관된 항복기준을 적용하여 소성 거동을 예측하고 기존 탄소성 모델에 비해 실험정수의 수가 적을 뿐만아니라 각각 물리적인 의미를 갖는다. 본 연구에서는 HISS 모델을 아스팔트 콘크리트 구조체의 해석 및 설계에 적용할 수 있도록 아스팔트 콘크리트 포장체의 대표적인 구성 재료에 대한 HISS 모델의 탄소성 실험 정수들을 구하였다.

역T형 옹벽의 형상에 따른 안정성 및 경제성 분석

柳知衡 慶一大學校 1993 論文集 Vol.9 No.1

To design the retaining walls, it is required to assume their shape and dimension initially. Their sections are finally determined by modifying repeatly to be satisfied with structural stability. When initially assumed dimensions are irreasonable, therefore, it is apt to do tiresome design procedure. In this study, analysis model is selected the most generally used cantilever retaining wall. A series of models are made by changing its height, slope of backfill, and frictional angle of backfill among several factors which have an effect on structural stability of retaining walls. The individual model is evaluated the safety of both overturning and sliding, as well as cost. From the parametric study, it is suggested the reasonable base width and length of toe relating to height of wall, slope of backfill, and frictional angle of backfill. Also, it is sjown that a resonable design is done by installing the shear key under the condition that frictional angle is 35。or less, when the base width is larger 0.6 and 0.5 time than its height regardless of the change in both height and slope.

화강토의 파쇄정도에 따른 공학적 특성

유지형 경일대학교 산업기술연구소 1993 産業技術硏究所 論文集 Vol.3 No.-

The grainite soil being widely distributed to all territories of Korea is frequently used as construction materials. The grain of grainite soils is physically and chemically unstable. According to impact, its crashability is great, and its shear strength is decreased when water content is high. The crashability has a great effect on the change in its grain size and all engineering characteristics such as shear strength. In this study, it is to analyze an engineering characteristics of grainite soils according to its crashability by performing a grain size analysis. shear strength test and premeability test while increasing the compaction energy over 15,25,50,75, and 100 compaction blows on the basis of A-1 compaction method. As the result of this analysis, it is shown that both shear strength and permeability coefficient of granite soils indicated their maximum or minimum value at a certain level of compaction energy without linearly increasing as the compaction energy. It is found that this compaction energy of the grainte soils sampled for this study is 1169 kg.cm/cm3. Also, it is shown that its grain of 0.84mm-2.00mm is the most sensitive od crashability.

토코페롤의 대장암세포 성장, 침윤, 부착에 대한 억제 효과

송보람, 주지형 충북대학교 생활과학연구소 2013 생활과학연구논총 Vol.17 No.2

The aim of the study was to investigate the inhibitory effects of different forms of tocopherols (T) on cell growth, invasion, and attachment in HCT116 human colon cancer cells. Treatment with γ-T and δ-T significantly inhibited cell growth (by 58.1-97.8% at the concentrations of 50-100 μM), invasion (by 49.4-87.0% at the concentrations of 20-80 μM), and attachment (by 28.2-75.4% at the concentrations of 50-100 μM). α-T, however, did not exhibit such inhibitory activities. δ-T was more active than γ-T in inhibiting cell attachment at the effective concentrations (p<0.05). These studies demonstrated the inhibitory activities of γ-T and δ-T against cell growth, invasion and attachment in HCT116 cells. More studies are needed in order to elucidate detailed mechanisms for the inhibitory action of γ-T and δ-T.

시멘트 콘크리트 포장의 임계하중 재하 위치에 관한 연구

조성하,유지형,김수일 연세대학교 산업기술연구소 1986 논문집 Vol.18 No.2

In this study, the critical loading position of cement concrete pavement is evaluated using the finite element method. In the analysis the temperature gradient of the slab is considered and 18 Kips is replaced by DB 24 as a standard load. The Winkler model under a 5-slab system which is linked with 4 joints in one direction is selected as foundation. The rigid pavement is subjected to the interior and the edge loading of DB 24 located on the various positions and then the maximum major principal stresses corresponding to the loading positions are calculated. It is found that the most critical stress occurs when the 2 rear axles of DB 24 are located symmetrically with a joint in the center on the edge and is affected by temperature gradient. Also, comparing the results of DB 24 with those of single axle load, it can be inferred that there is little differences of major principal stress between them.

가요성 포장체 물서의 해석적 추정

李茂洛,柳知衡 慶一大學校 1990 論文集 Vol.6 No.1

A back calculation procedure is developed to determine layer moduli of three layered flexible pavement structures from Falling Weight Deflectometer deflection basins. Regression equations to estimate layer moduli of flexible pavements are proposed through the regression analyses of theoretical deflection basins obtained by full factorial design. The relationships between the rate of change of moduli and deflections are developed for the efficient iteration. An back calculation procedure to ensure the accuracy of the layer moduli is proposed. The computer program of this procedure (MEPD1) is coded for personal computers. Validity and applicability of MEPD1 are verified and compared with those of FPEDD1 developed by Uddin, W. etal.

내적평형조건을 만족시키는 사면 안정 해석에 관한 연구

김수일,우동찬,유지형 연세대학교 산업기술연구소 1986 논문집 Vol.18 No.1

A computer program for slope stability analysis is developed based on the Hardin's Lever Arm Equilibrium Method which satisfies the internal equilibrium problem. The program developed in this study can handle circular and non-circular slope failure problems. The Hardin's method is compared with other methods which do not satisfy the internal equilibrium. and seismic effect on slope stability is quantiatively analyzed through numerical examples. From the numerical study, it is found that the Hardin's Lever Arm Equilibrium Method gives highly accurate results. compared with methods which do not satisfy the internal equilibrium. It is also found that the material properties such as cohesion. angle of internal friction. and unit weight of soil, have little influence on change of the factor of safety due to seismic forces. It is general trend that the factor of safety is exponentially decreased when the seismic coefficient is increased. An equation between the factor of safety and the seismic coefficient for homogeneous circular slip surfaces is proposed through statistical analysis.

1980년대(1981-1990) 전·후반기 피부과 외래환자의 통계적 비교 관찰

은 철,강승구,권상진,정성재,조지형,권철욱,김영진,김재홍 한양대학교 의과대학 1997 한양의대 학술지 Vol.17 No.1

To study the prevalence of common dermatoses 37,638 and 30,286 new outpatients who visited dermatology clinic with Hanyang University Hospital from January 1981 to December 1985 and from January 1986 to December 1990, respectively. Among the 37,638 outpatients in the first 5 years, the total number of male patients were 18,107(48.1%) and female patients were 19,531 (51.9%). Among the 30286 outpatients in the last 5 years, the total number of male patients were 14,705 (48.6%) and female patients were 15,581 (51.4%). In the both periods, the most frequent age groups was 21-30 (27.3%,25.2% respectively). The 15 common dermatoses, bacterial infection, seborreic dermatitis, drug eruption, verruca, syphilis, psoriasis, herpes zoster, and hypopigmentary disorder, in order of frequency. In thelast 5years, dermatophytosis, contact dermatitis, urticaria, acne, other eczema, atopic dermatitis, seborrheic dermatitis, bacterial infection, drug eruption, verruca, gerpes zoster, psoriasis, hypopigmentary disorder, scabies and syphilis were the 15 common dermatoses, as frequency. In both periods, the dermatosis which showed annually increasing tendency was dermatophytosis and those of decreasing tendency was bacterial infection. In the both periods, dermatophytosis, urticaria, bacterial infection, seborrheic dermatitis, verruca, and hypopigmentary disorder occurred most frequently during the summer season, and the incidence of other ecxema, scabies, atopic dermatitis, and herpes zoster increased during the winter season.

p53 Expression in patch Lesion of Mycosis fungoides

( Ji Hyeung Cho ),( Young Suck Ro ),( Chan Kum Park ),( Chang Woo Lee ) 대한피부과학회 1994 대한피부과학회 학술발표대회집 Vol.46 No.2

Case Reports : Lymphomatoid Papulosis Presenting a Single Nodule - Unusual Clinical Manifestation -

( Ji Hyeung Cho ),( Jae Hong Kim ),( Chan Kum Park ) 대한피부과학회 1996 Annals of Dermatology Vol.8 No.3