• 대한정형외과 초음파학회지
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• 제1권1호
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• pp.50-57
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• 2008

구조물에 대한 체계적 이해인 해부학과 그 역할에 대한 기능적 확인이라고 할 수 있는 신체 검진법은 슬관절을 진료하는 임상의로서 갖추어야 할 가장 기본적인 소양이라고 할 수 있다. 본문에서는 슬관절의 골성 구조, 반월상 연골, 전후방 십자 인대, 내외측 측부 인대, 근육, 내측 및 외측 삼층 구조 개념, 전후방 해부학, 슬관절 주위 점액낭에 대한 해부학 및 반월상 연골, 내외측 측부 인대, 전방 십자 인대, 후방 십자 인대 및 후측방 구조물에 대한 신체 검사에 대해 기술하였다. 해부학 및 신체 검진법에 대한 개념적이고 체계적인 이해는 슬관절을 치료하는 임상의에게 나침반과 등대와 같은 역할을 할 것이다.

• Journal of Mechanical Science and Technology
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• 제18권2호
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• pp.313-324
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• 2004

A rich phenomenon in the dynamics of azimuthal vortices in a circular cylinder caused by the inertial oscillation is investigated numerically at high Reynolds numbers and moderate Rossby numbers. In the actual spin-up flow where both the Ekman circulation and the bottom friction effects are included, the first appearance of a seed vortex is generated by the Ekman boundary-layer on the bottom wall and the subsequent roll-up near the corner bounded by the side wall. The existence of the small vortex then rapidly propagates toward the inviscid region and induces a complicated pattern in the distribution of azimuthal vorticity, i.e. inertial oscillation. The inertial oscillation however does not deteriorate the classical Ekman-pumping model in the time scale larger than that of the oscillatory motion. Motions of single vortex and a pair of vortices are further investigated under a slip boundary-condition on the solid walls. For the case of single vortex, repeated change of the vorticity sign is observed together with typical propagation of inertial waves. For the case of a pair of vortices with a two-step profile in the initial azimuthal velocity, the vortices' movement toward the outer region is resisted by the crescent-shape vortices surrounding the pair. After touching the border between the core and outer regions, the pair vortices weaken very fast.

• Wind and Structures
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• 제8권5호
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• pp.357-372
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• 2005

Mean and extreme pressure distributions on a large cantilevered flat roof model are measured in a boundary layer wind tunnel. The largest peak suction values are observed from pressure taps beneath conical "delta-wing type" corner vortices that occur for oblique winds, then the characteristics and causes of the local peak suctions are discussed in detail. Power spectra of fluctuating wind pressures measured from some typical taps located at the roof edges under different wind directions are presented, and coherence functions of fluctuating pressures are also obtained. Based on these results, it is verified that the peak suctions are highly correlated with the conical vortices. Furthermore, according to the characteristics of wind loads on the roof, an aerodynamic solution to minimize the peak suctions by venting the leading edges and the corners of the roof is recommended. The experimental results show that the suggested strategy can effectively control the generation of the conical vortices and make a reduction of 50% in mean pressures and 25% in extreme local pressures at wind sensitive locations on the roof.

• 국제초고층학회논문집
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• 제2권3호
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• pp.229-244
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• 2013

Twenty six pressure models of high rise buildings with various cross-sections including twisted models were tested in a boundary layer wind tunnel. The cross-sections were triangular, square, pentagon, hexagon, octagon, dodecagon, circular, and clover. This study investigates variations in peak pressures, and effects of various cross-sections and twist angles on peak pressures. To study the effects of various configurations and twist angles on peak pressures in detail, maximum positive and minimum negative peak pressures at each measurement point of the building for all wind directions are presented and discussed. The results show that peak pressures greatly depend on building cross-section and twist angle.

• 대한두개안면성형외과학회지
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• 제19권3호
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• pp.222-226
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• 2018

A 70-year-old male with a history of diabetes mellitus, hypertension, and coronary stent insertion visited our hospital 7 days after biting his lower lip. Swelling and inflammation had worsened despite debridement and antibiotic treatment. On the 8th hospital day, fungal infection with Candida albicans and superimposed bacterial infection with Klebsiella pneumoniae were found on tissue culture. Extensive necrosis resulted in a defect of approximately 3/4 of the entire lower lip and a full-layer skin defect from the vermilion to the gingivobuccal sulcus at the right corner of the mouth. To correct drooling, incomplete lip sealing, and trismus, staged reconstruction was performed with consideration of cosmetic and functional features. The treatment process using staged reconstruction and antifungal treatment for an extensive lower lip defect caused by fungal stomatitis is described.

• 한국전기전자재료학회논문지
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• 제17권7호
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• pp.713-717
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• 2004

In this study, the etched trench properties including cross-sectional profile, surface roughness, and crystalline defects were investigated depending on the various silicon etching and additive gases, For the case of HBr$He-O_2SiF_4$ trench etching gas mixtures, the excellent trench profile and minimum defects in the silicon trench were achieved. Due to the residual oxide film grown by the additive oxygen gas, which acts as a protective layer during trench etching, the undercut and defects generation in the trench were suppressed. To improve the electrical characteristics of trench gate, the hydrogen annealing process after trench etching was also adopted. Through the hydrogen annealing, the trench corners might be rounded by the silicon atomic migration at the trench corners having high potential. The rounded trench corner can afford to reduce the gate electric field and grow a uniform gate oxide. As a result, dielectric strength and TDDB characteristics of the hydrogen annealed trench gate oxide were remarkably increased compared to the non-hydrogen annealed one.

• Structural Engineering and Mechanics
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• 제90권6호
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• pp.551-568
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• 2024

The present study deals with static and dynamic behaviors including forced vibrations of an elastic rectangular nano plate on the two-parameter foundation. Firstly, the rectangular plate is assumed to be subjected to uniformly distributed and eccentrically applied concentrated loads. The governing equations of the problem are derived by considering the dynamic response of the plate, employing a series of the Chebyshev polynomials for the displacement function and applying the Galerkin method. Then, effects of the non-essential boundary conditions of the plate, i.e., the boundary conditions related to the shearing forces, the bending moments and the corner forces, are included in the governing equation of motion to compensate for the non-satisfied boundary conditions and increase the accuracy of the Galerkin method. The approximate numerical solution is accomplished using an iterative process due to the non-linearity of the unilateral property of the two-parameter foundation. The plate under static concentrated load is investigated in detail numerically by considering a wide range of parameters of the plate and the foundation stiffnesses. Numerical treatment of the problem in the time domain is carried out by assuming a stepwise variation of the concentrated load and the linear acceleration procedure is employed in the solution of the system of governing differential equations derived from the equation of motion. Time variations of the contact region and those of the displacements of the plate are presented in the figures for various numbers of the two-parameter of the foundation, as well as the classical and nano parameters of the plate particularly focusing on the non-linearity of the problem due to the plate lift-off from the unilateral foundation. The effects of classical and nonlocal parameters and loading are investigated in detail. Definition of the separation between the plate and the two-parameter foundation is presented and applied to the given problem. The effect of the lift-off on the static and dynamic behavior of the rectangular plate is studied in detail by considering various loading conditions. The numerical study shows that the effect of nonlocal parameters on the behavior of the plate becomes significant, when nonlinearity becomes more profound, due to the lift-off of the plate. It is seen that the size effects are significant in static and dynamic analysis of nano-scaled rectangular plates and need to be included in the mechanical analyses. Furthermore, the corner displacement of the plate is affected more significantly from the lift-off, whereas it is less marked in the time variation of the middle displacement of the plate. Several numerical examples are presented to examine the sensibility of various parameters associated with nonlocal parameters of the plate and foundation. Both stiffening and softening nonlocal parameters behavior of the plate are identified in the numerical solutions which show that increasing the foundation stiffness decreases the extent of the contact region, whereas the stiffness of the shear layer increases the contact region and reduces the foundation settlement considerably.

• 대한기계학회논문집
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• 제16권10호
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• pp.1979-1989
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• 1992

본 연구에서는 말굽와류에 대한 전반적인 사항을 고찰하는 한편, 실린더의 기 하학적 형상이 말굽와류에 미치는 영향을 정성적으로 고찰하는 데 있다. 그러므로 본 실험에서는 먼저 경계층이 형성되어 있는 평판에 원형 실린더를 설치하여, 말굽와 류에 의한 3차원 유동현상을 고찰하고, 또한 동일한 평판에 쐐기형상의 실린더를 설치 하여, 그 주위에서 발생하는 3차원 유동현상과 원형 실린더 주위에서 일어나는 3차원 유동현상과의 정성적인 비교를 통하여, 말굽와류에 의한 3차원 유동손실을 줄일 수 있 는 가능성을 제시하고자 한다.

• Structural Engineering and Mechanics
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• 제65권6호
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• pp.679-687
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• 2018

In composite materials technology, the fiber-reinforced polymers (FRP) have opened up new horizons in infrastructural engineering field for strengthening existing structures and components of structure. The Carbon fiber reinforced polymer (CFRP) sheets are well suited for RC columns to this application because of their high strength to weight ratio, good fatigue properties and excellent resistance to corrosion. The main focus of present experimental work is to investigate effect of shapes on axial behavior of CFRP wrapped RC columns having same cross-sectional area and slenderness ratio. The CFRP volumetric ratio and percentage of steel are also adopted constant for all the test specimens. A total of 18 RC columns with slenderness ratio four were cast. Nine columns were control and the rest of nine columns were strengthened with one layer of CFRP wrap having 35 mm of corner radius. Columns confined with CFRP wrap were designed using IS: 456:2000 and ACI 440.2R.08 provisions. All the test specimens were loaded for axial compression up to failure and failure pattern for each shaped column was investigated. All the experimental results were compared with analytical values calculated as per the ACI-440.2R-08 code. The test results clearly demonstrated that the axial behavior of CFRP confined RC columns is affected with the change in shapes. The axial deformation is higher in CFRP wrapped RC circular column as compared to square and rectangular columns. Stress-strain behaviour revealed that the yield strength gained from CFRP confinement was significant for circular columns as compare to square and rectangular columns. This behaviour may be credited due to effect of shape on lateral deformation in case of CFRP wrapped circular columns at effective confinement action.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1869-1872
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• 2003

As SLA(Sterealithography), SLS(Selective Laser Sintering), LOM(Laminated Object Manufacturing), FDM(Fused Deposition Modeling) etc. The FDM system the heart of a study and is developed by Stratasys co. ltd, in US., is small and cheap R.P. The material filament is heated until the material reaches a near-liquid state, it is pumped through a nozzle and become hand with a shape required, and this nozzle move pumping on the previously deposited material. Such FDM system that choice deposition type with X-Y plouter obtain in the thin continue layer by decreasing amount of extrusion or to central the injection amount when the head slow down at the corner, but in the process that fusion wax or resin become hand, deformation occur and it will affect the shape accuracy and the surface roughness. Such effect will depreciate quality and reliability of the product. Therefore, when the product made in actuality, the fundamental study on the basis geometry(surface, volume, line, angle) must be preceded and it have been research by many Free Form Fabrication. So, this basic object study purpose to obtain the fundamental geometry data and to enhance the surface roughness of the shape. And an operant can use the data for the progress of the surface roughness. This study research the estimation and application of the prototype surface roughness by adjustment the injection amount. And basie of this research, describe the pattern of prototype surface roughness and also used the result to estimate the surface of prototype.