• Title/Summary/Keyword: Displacements

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A Surface Image Velocimetry Algorithm for Analyzing Swaying Images (흔들리는 영상 분석을 위한 표면 영상 유속계 알고리듬)

  • Yu, Kwonk-Yu;Yoon, Byung-Man;Jung, Beom-Seok
    • Journal of Korea Water Resources Association
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    • v.41 no.8
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    • pp.855-862
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    • 2008
  • Surface Image Velocimetry (SIV) is an instrument to measure water surface velocity by using image processing techniques. To improve its measuring accuracy, it is essential to get high quality images with low skewness. A truck-mounted SIV system would be a good way to get images, since its crane gives high altitude to the images. However, the images taken with a truck-mounted SIV would be swayed due to the movement of crane and the camera by winds. In that case, to analyze the images, it is necessary to compensate the side sway in the images. The present study is to develop an algorithm to analyze the swayed images by combining common image processing techniques and coordinate transform techniques. The system follows the traces of some selected fixed points and calculates the displacements of the video camera. By subtracting the average velocity of the fixed points from that of grid points, the velocity fields of the flow can be corrected. To evaluate the system's performance, two image sets were used, one image set without side sway and another set with side sway. The comparison of their results showed very close with the error of around 6 %.

Shaking Table Test of a 1/10 Scale Isolated Fifteen-story Flat Plate Apartment Building (면진층을 가지는 1/10 축소된 15층 무량판 아파트건물의 진동대 실험)

  • Chun, Young-Soo
    • Land and Housing Review
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    • v.2 no.3
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    • pp.287-297
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    • 2011
  • This paper presents the results of performance verification tests of the isolated flat plate apartment building with the laminated rubber bearings. The shaking table test is carried out in CABR(China Academy of Building Research) with two 1/10 scale isolation and non-isolation models under 4 excitation waves. The shaking table test is proceeding from x axis, y axis and x+y axis with different amplitude of acceleration values. The results show that, to non-isolated model, the natural vibration period is remarkably decreased and entered non-linear condition after moderate earthquake. Its accelerations become lager with increasing storey number and completely collapsed under large earthquake. The inter-storey shifts largely exceed the limit values of regulated displacement angles. But to isolated model, the natural vibration period of isolated modal is almost the same in all conditions and still in its elastic condition. The earthquake loading is greatly reduced and the accelerations of superstructure are greatly reduced. The inter-storey drifts are very small and can be neglected. The isolated model is in translational state and can be seen as a rigid whole. The displacements of isolation layer are in the allowable range. This experiment demonstrates that the seismic isolation is very effective to mitigate the influence of earthquake on structures and it is possible to increase the serviceability due to decrease the floor acceleration. facilities from their good states that is superior to non-isolated structure.

Neutron Diffraction Study on the Crystal Structure of Yttria-Stabilized Zirconium Oxide (중성자회절법을 이용한 이트리아 저코니아의 결정구조 연구)

  • Jin-Ho Lee;Chang-Hee Lee;Won-Sa Kim
    • Journal of the Mineralogical Society of Korea
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    • v.13 no.3
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    • pp.164-170
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    • 2000
  • Neutron single crystal and powder diffraction techniques have been applied to the structure analysis of yttria-stabilized zirconium, Z $r_{0.73}$ $Y_{0.27}$ $O_{1.87}$., prepared by the skull-melting method. The crystal structure has been determined to be cubic symmetry, space group Fm/equation omitted/ with a=5.155(2)$\AA$, V=136.99(5)$\AA$, Z=4, and R(F)=5.65%, $\omega$R(I)=10.57% for 70 integrated intensities of Bragg Peaks observed from single crystal of Z $r_{0.73}$ $Y_{0.27}$ $O_{1.87}$. The stabilizer atoms randomly occupy the zirconium sites and there are displacements of oxygen atoms with amplitudes of $\Delta$/a~0.033 and 0.11 along <110> and <100> directions from the ideal positions of the fluorite structure, respectively. There are no significant differences in crystallographic data between the single crystal and powder studies. Diffraction pattern after Rietveld refinement, using neutron powder data, has shown the evidence of a tetragonal impurity phase, or a slight tetragonal distortion.

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Structural Analysis of Built-in Side-by-Side Refrigerator with Ice Dispenser and Home Bar and Evaluation of Door Differences and Gasket Gap (얼음디스펜서와 홈바가 있는 빌트인 양문형 냉장고의 구조해석 및 도어 단차와 개스킷 간극의 평가)

  • Ryu, Si-Ung;Lee, Boo-Youn
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.9
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    • pp.465-473
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    • 2018
  • A cabinet-door integrated finite element model for a built-in side-by-side refrigerator with an ice dispenser and home bar was constructed, and its deformation was analyzed by ANSYS. As loads, the food load in the shelf and baskets, and thermal load occurring during the normal operation condition were considered. From results of the analyses, the door height difference (DHD) and door flatness difference (DFD) between the two doors, and the increase in the gap of the door gasket, which affects the sealing of cool air in the cabinet, were derived. As results of an evaluation of the differences, the DHD and DFD under the assembled condition satisfied the acceptance criteria of the manufacturer. The food and thermal loads increased the DHD and DFD due to thermal deformation, and the DFD increased significantly. In addition, the increase in the gap of door gasket located between the cabinet and doors was derived from the results of displacements under the food and thermal loads. The evaluation showed that the maximum increase in gap appeared at the left edge of the freezing compartment gasket, which satisfied the acceptance criteria of the manufacturer.

Development of Integrated Model of Boiler and Its Supporting Steel Structure of Coal-Fired Power Plant for Finite Element Analysis (유한요소해석을 위한 석탄화력발전소의 보일러와 지지 철골의 통합모델 개발)

  • Lee, Boo-Youn
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.4
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    • pp.9-19
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    • 2020
  • An integrated finite element model composed of a boiler and its supporting steel structure for a 375-MW coal-fired power plant was developed. This study used the developed model for seismic analysis using SAP2000 software. For the complex superheaters, reheaters, economizers, and membrane walls of the boiler, which consisted of numerous tubes, a method of modeling them by the equivalent elements in the viewpoint of stiffness and/or inertia was proposed. In addition, a method of modeling for the connection between the boiler and steel structure was proposed. Many hangers that connect the boiler to the girders of a steel structure were transformed into equivalent hangers by decreasing the number. The displacements of the boiler stoppers on the buckstay and the posts of the steel structure were coupled by considering their interface condition. Static analysis under the self-loading condition for the developed integrated model was implemented, and the results of deformation indicated that the behavior of the steel members and the major components of the boiler were appropriate. In conclusion, the integrated model developed in this study can be used to evaluate the safety of the boiler and steel structure under seismic loads.

Analysis of Landslide Hazard Map during Earthquake with Various Degrees of Saturation and Cohesion Values (포화도 및 점착력 변화에 따른 지진시 산사태 위험도 분석)

  • Lee, Joonyong;Han, Jin-Tae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.3
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    • pp.599-606
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    • 2015
  • Damage of landslide due to earthquake covers a considerable part of total damage due to earthquake. Landslide due to earthquake affects direct damage of human lives and structures, and social system can be paralyzed by losing functions of roads, basic industries, and so on. Therefore, systematic and specialized research examining the factors affecting the slope stability by earthquakes should be needed. However, method of evaluation of slope stability problems due to earthquake contains somewhat uncertainty since many soil properties are predicted or assumed. In this study, influences of change of soil properties such as degree of saturation and cohesion value are analyzed in factor of safety and displacement using seismic landslide hazard maps based on GIS. As the degree of saturation increases or cohesion decreases, it is found that seismic landslide hazard area marked with factors of safety or displacements tends to increase. Therefore, to draw more exact landslide hazard map during earthquake, it is necessary to obtain accurate soil property information preferentially from site investigation data in the field.

Fatigue Strength Evaluation of Steel-Concrete Composite Bridge Deck with Corrugated Steel Plate (절곡강판을 이용한 교량용 강-콘크리트 합성 바닥판의 피로 성능평가)

  • Ahn, Jin Hee;Sim, Jung Wook;Jeong, Youn Joo;Kim, Sang Hyo
    • Journal of Korean Society of Steel Construction
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    • v.20 no.6
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    • pp.731-740
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    • 2008
  • This paper deals with the fatigue behavior and strength of a new-type of steel-concrete composite bridge deck. The new-type composite bridge deck consists of corrugated steel plate, welded T-beams, stud-type shear connectors and reinforced concrete filler. A total of eight composite bridge deck specimens were fabricated, the fatigue tests were conducted under four-point bending test with three different stress ranges in constant amplitude. According to the test results, the fatigue crack generated at the welding part of the corrugated steel plate, progressed down to the bottom of the steel plate and encountered the crack, which came out from the opposite side at the same position. After the two cracks were connected at the bottom of the steel plate, the lower flange was cut off and the fatigue crack developed up to the T-beam. And the displacements and strains of fatigue test specimens were increasing with cyclic loading number, these were changed sharply at the fatigue failure. The fatigue results are compared with the design S-N curves specified in the Korea Highway Bridge Design Specifications and data in NCHRP 102 and NCHRP 147 report. The new-type composite bridge deck has a stress category of C, which means that new-type composite bridge deck can be designed by the current fatigue design specifications provided for steel members.

Equivalent Suspension Bridge Model for Tower Design of Multi-span Suspension Bridges (다경간 현수교 주탑 설계를 위한 등가 현수교 모델)

  • Choi, Dong-Ho;Na, Ho-Sung;Yi, Ji-Yop;Gwon, Sun-Gil
    • Journal of Korean Society of Steel Construction
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    • v.23 no.6
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    • pp.669-677
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    • 2011
  • The multi-span suspension bridge generally has more than three towers and two main spans. To economically and effectively design a multi-span suspension bridge, the proper stiffness ratio of the center tower to the side tower must be determined. This study was conducted to propose a method of figuring out briefly the structural behavior of the towers in a multi-span suspension bridge. In the equivalent suspension bridge model, the main cable of the multi-span suspension bridge is idealized as an equivalent cable spring, and the external loads of horizontal and vertical forces that were calculated using the tensile forces of the main cable were applied on top of the towers. The equilibrium equations of the equivalent multi-span suspension bridge model were derived and the equations were solved via nonlinear analysis. To verify the proposed method, a sample four-span suspension bridge with a main span length of 3,000 m was analyzed using thefinite element method. The displacements and moment reactions of each tower in the proposed method were compared with the FEM analysis results. Consequently, the results of the analysis of the equivalent suspension bridge model tended to be consistent with the results of the FEM analysis.

A Biomechanical Comparative Analysis between Single-Radius and Multi-Radius Total Knee Arthroplasty for Sit-to-Stand Movement (앉았다 일어나는 동작동안 단축회전반경 무릎인공관절 수술자와 다축회전반경 무릎인공관절 수술자의 운동역학적 비교분석)

  • Jin, Young-Wan
    • Journal of Life Science
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    • v.16 no.5
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    • pp.773-779
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    • 2006
  • Eight of the individuals had a unilateral S-RAD TKA and Multi-Radius TKA ($Scorpio^{TM}$ PS, Howmedica-Osteonics, Inc.). The instrument were used Peak Motion Measurement $System^{TM}$, $MYOPAC^{TM}$EMG System, KIN-COM $III^{TM}$ System. The Figure 3 shows that the average time for the S-RAD group to accomplish the sit-to-stand movement was 1.59 s, which was 0.19 s less than the M-RAD group (p= 0.033). In Figure 5, the S-RAD TKA group tended to have $7^{\Omega}{\cdot}S^{-1}$ less trunk flexion velocity than that of the M-RAD group (p= 0.058). The Figure 6 shows that the S-RAD TKA limb tended to have less ADD displacement (p = 0.071) than that of the M-RAD TKA limb. We failed to find significant differences for ABD and ADD displacements between the S-RAD and M-RAD N-TKA limbs (p= 0.128 and 0.457, respectively). The VM of the S-RAD TKA limb demonstrated significant less RMS EMG than that of the M-RAD TKA limb from $60^{\Omega}$ to $15^{\Omega}$ of knee flexion (p 0.05). The VL of the S-RAD TKA limb also demonstrated significant less RMS EMG than that of the M-RAD TKA limb from $60^{\Omega}$ to $45^{\Omega}$ of knee flexion (p 0.05). Similar to the VM and VL, the RF of the S-RAD TKA limb showed less RMS EMG than that of the M-RAD TKA limb from $60^{\Omega}$ to $30^{\Omega}$ of knee flexion (p 0.05).

The Objective Measurement of the Lung Parenchyma Motion for Planning Target Volume Delineation (폐 부위 Planning Target Volume(PTV)설정시 폐 움직임의 객관적 측정)

  • Chung, Weon-Kyu;Cho, Jeong-Gill
    • Radiation Oncology Journal
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    • v.15 no.4
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    • pp.387-392
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    • 1997
  • Purpose : To quantify the movement of lung Parenchyma for ICRU 50 Planning Target Volume (PTV) delineation of the lung region. Materials and Method : Fluoroscopic observations and measurements are Performed on 10 patients with chest region cancer who have normal putmonary functions We have divided the lung region into 12 parts for the right lung, 10 parts for the left lung and four to five Points of lung parenchyma were selected for anatomical analysis Points, Fluoroscopic images are sent to a computer and then movements are measured. Results : Both lowe lobes showed the longest longitudinal movements because of breathing (average 14.1mm, maximum 22.1mm), while anteroposterior displacement showed the smallest value. Lateral movements of the lung parenchyma averaged 6.6mm, and the maximum value was 9.1mm, (both hilar regions showed maximum values because of cardiac motion) Conclusion : We could quantify the lung movements by measuring parenchyma displacements. The movements of both upper lobes were less than those of the middle and upper lobes in longitudinal and transverse movements. Optimal margins can be selected for PTV delineation using these results.

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