• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.498-501
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• 2006

R.C. Rahmen bridges have been widely constructed in the location of interchange or narrow road crossing. In addition, skewed or curved rahmen bridges are mostly constructed in comparison with normal rahmen bridges for the purpose of maintaining the route of road or considering the beauty of bridge. However, due to the functional characteristics, rahmen bridges are sustained under the direct vehicle loads and the side directional earth pressure so that the stress concentration with respect to the geometrical eccentricity can be occurred if rahmen bridges are constructed in large amount of skew. In this investigation, the behavior of skewed rahmen bridges which is located in curved route has been analysed to investigate the additional effects on the change of stress concentration. As a result, it is judged that the stress of curved rahmen bridges is more concentrated than the stress of straight rahmen bridges in the region of obtuse angle. However, in the middle of slab, the curve does not affect on the stress concentration.

• 한국소음진동공학회논문집
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• 제14권10호
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• pp.999-1006
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• 2004

Recently, the ride comfort problem becomes increasingly important because of today's needs for train speedup. The railway has the track irregularities which cause vibrations, such as rail joints, turnout, level crossing, transition corves and super-elevation ramps, and variations in the track level(z-axis) and the gauge(y-axis). In Korea, the service run of the high speed train has been made since the 1st of April, 2004. The commercial high-speed trains must be run on the compound lines which are composed of high-speed line and conventional line. The high speed lines in both Kyoungbu line and Honam line have 57.5％ and 33.8％, respectively In this Paper, the ride comfort has been reviewed by the various experimental methods when the high-speed trains are operated on both Kyoungbu line and Honam line. The results show that the high-speed train has no problems from the viewpoint of the comfort ride during the operation on the high speed line and conventional line.

• 제어로봇시스템학회논문지
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• 제9권7호
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• pp.507-514
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• 2003

Inspection and shape measurement of three-dimensional objects are widely needed in industries for quality monitoring and control. Recently the shape measurement using interferometric principle is found to be a successful methodology among other visual or optical technologies. Especially, the measuring method using wavelength scanning interferometer(WSI) has a great advantage in comparison with other conventional jnterferometric methods in that the absolute distance from the reference surface can be directly obtained from the amount of jnterferometric phase change. However, the measurement methods using WSI proposed by other researchers have low measurement resolution so far because they can't measure fractional phase change. To avoid this shortcoming we propose a new algorithm in this paper, which can obtain a small amount of even fractional phase change by sinusoidal function fitting. To evaluate the effectiveness of the proposed sinusoidal function fitting algorithm, a series of measuring experiments are conducted for discontinuously shaped specimens which have various height. The proposed algorithm shows much more enhanced measurement resolution than other existing conventional algorithms such as zero crossing algorithm and Fourier transform algorithm.

• 한국자동차공학회논문집
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• 제13권4호
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• pp.58-65
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• 2005

A method measuring angular speed and estimating angular acceleration of an automotive wind shield wiper pivot with limited resources has been proposed. Limited resources refer to the fact that processes cannot be operated in real-time with a regular notebook running a Microsoft Windows. Also, they refer to the fact that data acquisition cards have only two general purpose counters as many generic cards do. An optical incremental encoder has been employed for measuring angular motion. To measure the angular speed of the pivot, periods for the encoder's output pulses have been measured as the speed is related to the reciprocal of the period. Since only information acquired from one counter channel is the magnitude of the angular speed, sign correction is necessary. Also the information for the exact time when a pivot passes left and right dead points is also missing and the situation is inherent to the hardware setup. To find out the zero-crossing time of the angular speed, a linear interpolation technique has been employed. Lastly, to overcome the imperfection of the mechanical encoders, the angular speed has been curve fitted to a spline. Angular acceleration can be obtained by a differentiation of the angular speed.

• Structural Engineering and Mechanics
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• 제88권4호
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• pp.311-322
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• 2023

Riverine flood is one of the critical natural threats to river-crossing bridges. As floods are the most-occurred natural hazard worldwide, survival probability of bridges due to floods must be assessed in a speedy but precise manner. In this regard, the paper presents a reliability-based approach for a rapid assessment of failure probability of vulnerable bridge components under floods. This robust method is generic in nature and can be applied to both concrete and steel girder bridges. The developed methodology essentially utilizes limit state performance functions, expressed in terms of capacity and flood demand, for probable failure modes of various vulnerable components of bridges. Advanced First Order Reliability Method (AFORM), Monte Carlo Simulation (MCS), and Latin Hypercube Simulation (LHS) techniques are applied for the purpose of reliability assessment and developing flood fragility curves of bridges in which flow velocity and water height are taken as flood intensity measures. Upon validating the proposed method, it is applied to a case study bridge that experiences the flood scenario of a river in Gujarat, India. Research outcome portrays how effectively and efficiently the proposed reliability-based method can be applied for a quick assessment of flood vulnerability of bridges in any flood-prone region of interest.

• 대한치과교정학회지
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• 제32권4호
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• pp.275-291
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• 2002

스트레이트 와이어 장치의 효율적 운영을 위해서 제시되어야 할 여러 사항 중 치관의 굴곡도에 대한 연구는 국내, 외에서 매우 미흡하다. 이에 본 연구는 한국인 영구치의 순, 협측 임상치관 굴곡도를 조사하기 위해 시행되었다 이를 위해 정상적인 해부학적 구조를 갖고있는 구강 석고모형 36쌍을 대상으로 3차원 레이저 스캐닝 하였다. Andrews plane 과 Facial axis of clinical crown(FACC)을 각각 수평 , 수직 기준선으로 설정하고, 이들로부터 상, 하 방향과 좌, 우 방향으로 각각 1m간격으로 2개 혹은 3개씩의 선을 그었다. 이들 선이 교차하는 점들에 대한 3차원적 점 좌표를 만들어 놓고 36쌍 구강 석고모형의 각각 좌표점들의 평균을 구하였다 3차원 좌표 점(x,y,z)을 이용해 곡면 방정식을 만들어 각 치아의 곡률을 구하였고, 가로, 세로 각 방향의 2차원 곡선으로 단순화시킨 곡선에서의 곡률을 구하여 치아 부위마다의 곡률 변화를 계측하여 다음과 같은 결론을 얻었다. 1. 한국인 영구치 치관의 순, 협면 굴곡도의 기초자료를 얻었다. 2. 남, 녀 간에 치관 굴곡도 차이는 없었다. 3. 개개 치아의 치관 굴곡에 대한 특성 1) 상악 중절치에서 치은쪽과 절단면쪽의 곡률 차이가 다른 치아에 비해 심하였으며, 치은쪽이 더욱 심한 곡률을 보였다. 2) 상악 견치의 치관 굴곡도는 근심-절단면쪽의 굴곡이 다른면에 비해 더 심하였다. 3) 상악 제 1소구치에서는 근심-교합면쪽과 원심-치은쪽에서의 굴곡이 더 심하여 치관 표면의 굴곡이 대각선 방향으로 서로 뒤틀린 반면, 상악 제 2소구치에서는 근심 끝과 원심 끝의 치관 표면 굴곡이 비슷하여 서로 평행하게 나타났다. 4) 하악 중절치와 하악 측절치의 치관 굴곡도에는 유의한 차이가 없었다. 5) 하악 제 2소구치의 교합면-치은쪽으로의 굴곡이 하악 제 1소구치나 상악 제 2소구치에 비하여 더 둥근 것으로 나타났다. 이상의 결과로 볼 때, 하악 중절치와 측절치는 브라켓 베이스를 같게 해도 무방하다. 그러나 상악 제 1소구치와 제 2소구치, 그리고, 하악 제 1소구치와 제 2소구치는 치관 굴곡도에 차이가 있으므로 브라켓 제작시 베이스의 굴곡을 다르게 하여야 한다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.192-194
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• 2002

We present the results on the calibration of iso-center positions using the quality assurance system established at PMRC for determination of center position in X-ray and proton irradiation fields. Details on the system are presented in another presentation in this session. The equipment in the system is mounted on a patient treatment bed in each proton exposure room, G1 or G2. A center of a stainless ball on the equipment is set at a cross of laser markers located around the iso-center and fixed on the room and on the snout in the gantry. A proton beam or an X-ray beam is exposed onto the ball through a brass collimator of 100 mm ${\times}$ 100 mm and projected onto the imaging plate set at I cm behind the ball. On the axis perpendicular to the thrust axis of the gantry on the imaging plate, a distance between a center of the collimator image and a center of the ball image varies as a cosine function of gantry angles unless the ball is set on the iso-center. An amplitude of the cosine curve shows the distance between the ball and the iso-center, an offset the offset of the collimator, and a phase shift at a zero crossing point the ball direction viewed from the iso-center. We present the relation among the iso-center position, the laser maker position, and the center of proton and X-ray irradiation fields. Its stability and its reproducibility are discussed.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.143-148
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• 2012

The photodissociation dynamics of cyclopropyl bromide ($C_3H_5Br$) and cyclobutyl bromide ($C_4H_7Br$) at 234 nm was investigated. A two-dimensional photofragment ion-imaging technique coupled with a [2+1] resonanceenhanced multiphoton ionization scheme was utilized to obtain speed and angular distributions of the nascent $Br(^2P_{3/2})$ and $Br^*(^2P_{1/2})$ atoms. The recoil anisotropies for the Br and $Br^*$ channels were measured to be ${\beta}_{Br}=0.92{\pm}0.03$ and ${\beta}_{Br^*}=1.52{\pm}0.04$ for $C_3H_5Br$ and ${\beta}_{Br}=1.10{\pm}0.03$ and ${\beta}_{Br^*}=1.49{\pm}0.05$ for $C_4H_7Br$. The relative quantum yield for Br was found to be ${\Phi}_{Br}=0.13{\pm}0.03$ and for $C_3H_5Br$ and $C_4H_7Br$, respectively. The soft radical limit of the impulsive model adequately modeled the related energy partitioning. The nonadiabatic transition probability from the 3A' and 4A' potential energy surfaces was estimated and discussed.

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.2962-2968
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• 2009

The photodissociation dynamics of 1,2-bromochloroethane ($C_2H_4BrCl$) was investigated near 234 nm. A two-dimensional photofragment ion-imaging technique coupled with a [2+1] resonance-enhanced multiphoton ionization scheme was utilized to obtain speed and angular distributions of the nascent Br($^2P_{3/2}$) and Br${\ast}($^2P_{1/2}$) atoms. The total translational energy distributions for the Br and Br${\ast}$ channels were well characterized by Gaussian functions with average translational energies of 100 and 84 kJ/mol, respectively. The recoil anisotropies for the Br and Br${\ast}$ channels were measured to be ${\beta}$ = 0.49 ${\pm}$ 0.05 for Br and 1.55 ${\pm}$ 0.05 for Br${\ast}$. The relative quantum yield for Br${\ast}$ was found to be ${\Phi}_{Br{\ast}}$ = 0.33 ${\pm}$ 0.03. The probability of nonadiabatic transition between A' states was estimated to be 0.46. The relevant nonadiabatic dynamics is discussed in terms of interaction between potential energy surfaces in Cs symmetry.

• 혜화의학회지
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• 제19권1호
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• pp.87-98
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• 2010

There are four kinds of diagnosis methods in oriental medicine, and viewing diagnosis(望診) is the most important method among them. There are two ways in viewing diagnosis. These are viewing shape(觀形) and inspecting color(察色). Viewing shape diagnosis includes observation on geometric curve that is made by prominence of bones or lump of flesh, and examination on symmetric disparity and balance of vertical length among three vertical section of face. Inspecting color is literally inspecting several specified region of face. By Viewing shape, we can learn about characteristic physical mechanism of individuals, and basic disposition of reaction from inside and outside infinite stimulations. On the other hand, by inspecting color, we can estimate the very present pathologic and physiologic status of the patient. the estimation is based on principle that inside body changes reveal some reflections on facial skin surface. When you diagnosis patients with inspecting color method, It is important to distinguish color delicately, and to know where to see and what to know from it. The most important and frequently mentioned regions are myong-dang(明堂), eyes(眼) and In-dang(印堂). Myong-dang(明堂) indicates nose. In-dang(印堂) indicates the space between eyebrows. Unlike myong-dang(印堂) and eyes, In-dang(印堂) is occasionally treated as a trivial region then others. But, from research on classical books of facial examination and consideration of it's locational meanings, we've learned In-dang(印堂) is very important in viewing diagnosis, because this region is crossing of the other two regions and this fact means this region expresses the spiritual status as well as physical status in one region.