• Title/Summary/Keyword: moving force

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A Study on the Precise Lineament Recovery of Alluvial Deposits Using Satellite Imagery and GIS

  • 이수진;황종선;이동천;김정우;석동우
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.62-62
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    • 2003
  • Landsat TM 영상을 이용, 명암차가 높은 산악 지역에 적용해왔던 알고리즘을 개선하여 비교적 명암차가 낮고 넓게 분포하는 충적층 지역의 선구조를 추출하는 알고리즘을 개발하였다. 수치지형모델(OEM)에 대하여 Local Enhancement 를 이용해서 평탄한 지역을 선정하여 이로부터 충적층을 추출하였다. Zevenbergen & Thorno's Method를 3×3 moving windowing을 통해서 최대 경사방향과 경사를 구해서 충적층을 지나는 선구조 요소를 추출하고 다시 Hough 변환을 이용해서 1차 선구조를 추출하였다 이를 이용하여 충적층의 직각방향의 지형단면의 경사를 유추해서 spline 보간법을 이용해 단면의 최저점을 구하고 이 구해진 점들을 다시 Hough 변환을 이용해서 최종 선구조를 추출하였다. 본 연구에서 사용한 알고리즘은 기존 알고리즘에서 사용된 소창문보다 훨씬 큰 충적층이 분포하는 지역의 지형 경사가 수렴하는 부분에 선구조가 뚜렷이 나타남을 볼 수 있다. 최대경사방향과 경사를 구해서 얻어진 1 차선구조와 최종 선구조에서 선구조 방향이 다소 차이를 보인다. 1 차 선구조의 수직방향 지형단면의 자료를 이용함에 있어, 지형 단면의 시작정과 끝지점을 임의적으로 결정하는 것이 아니라, 충적층을 가로질러 최고점까지 또는 다음 충적층이 나을 때까지의 자료를 이용해서 보간법을 사용하였고, 충적층의 넓이에 따라 보간할 자료량의 차이에 의한 오차가 발생할 수 있다. 넓은 충적층에서 선구조가 잘 추출되는 반면에 좁은 충적층이 분포하거나 계곡에 해당하는 지역에l서는 경사수렴부와 일치하지 않는 선구조가 추출되었다. 이는 향후 계속적으로 연구해서 보완되어야 할 것으로 사료된다.페클 잡영 제거 정도에 있어 다른 필터들과 큰 차이가 없지만 경계선보존지수는 다른 필터들에 비하여 가장 우수함을 확인할 수 있었다.rbon 탐식효율을 조사한 결과 B, D 및 E 분획에서 유의적인 효과를 나타내었다. 이상의 결과를 종합해볼 때, ${\beta}$-glucan은 고용량일 때 직접적으로 또는 $IFN-{\gamma}$ 존재시에는 저용량에서도 복강 큰 포식세로를 활성화시킬 뿐 아니라, 탐식효율도 높임으로써 면역기능을 증진 시키는 것으로 나타났고, 그 효과는 crude ${\beta}$-glucan의 추출조건에 따라 달라지는 것을 알 수 있었다.eveloped. Design concepts and control methods of a new crane will be introduced in this paper.and momentum balance was applied to the fluid field of bundle. while the movement of′ individual material was taken into account. The constitutive model relating the surface force and the deformation of bundle was introduced by considering a representative prodedure that stands for the bundle movement. Then a fundamental equations system could be simplified considering a steady state of the process. On the basi

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ORTHODONTIC TREATMENT WITH MINISCREWS IN MIXED DENTITION (혼합치열기의 miniscrew를 이용한 교정치료)

  • Lim, Su-Min;Yang, Yeon-Mi;Kim, Jae-Gon;Baik, Byeong-Ju;Lee, Yong-Hun;Shin, Jeong-Geun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.35 no.2
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    • pp.367-375
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    • 2008
  • Anchorage plays an important role in orthodontic treatment. Skeletal anchorage like the miniscrew is considered a more effective method in anchorage control than conventional anchorage which needs much patient's cooperation. The miniscrew offers many advantages. 1) It is easy to insert and to remove. 2) It can endure the force needed for moving teeth. 3) It can be immediately loaded and 4) Patient cooperation is not needed. 5) It is economic compared to other skeletal anchorage systems. In comparison to adult's bones, children's bones have comparatively poor bone quality and quantity. Therefore, it is hard to obtain primary stability in younger patients. However, if the miniscrew can be retained successfully, it will be effective in many orthodontic treatments. In these cases, we used the miniscrew in correcting of diastema, in aligning dental midline, and in rendering a forced eruption of impacted tooth in mixed dentition patient. We obtained satisfactory results.

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Dynamics modeling and performance analysis for the underwater glider (수중 글라이더의 운동특성을 고려한 동역학 모델링 및 운동성능 해석)

  • Nam, Keon-Seok;Bae, Jae-Hyeon;Jeong, Sang-Ki;Lee, Shin-Je;Kim, Joon-Young
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.7
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    • pp.709-715
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    • 2015
  • Underwater gliders do not typically have separate propellers for forward motion. They generate propulsive forces based on the difference between their buoyancy and gravity. They can control the volume from the buoyancy engine to adjust the propulsive force. In addition, the attitude of the underwater glider is controlled by a rubberless motion controller. The motion controller can change the mass center and moment of inertia of the inner moving mass. Owing to the change in these parameters, the attitude of the underwater glider is changed. In this study, we derive nonlinear, six degree of freedom (DOF) mathematical models for the motion controller and buoyancy engine. Using these equations, we perform dynamic simulations of the proposed underwater glider, and verify the suitability of the design and dynamic performances of the proposed underwater glider. We then perform the motion control simulation for the pitch and roll angle, and analyze the dynamic performance according to the pitch and roll angles.

A Critical Note on the Electric Field in Direct and Alternating Current and Its Consciousness

  • Oh, Hung-Kuk
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2000.11a
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    • pp.98-104
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    • 2000
  • The conventional model did not take momentum conservation into consideration when the electron absorbs and emits the photons. II-ray provides momentum conservations on any directions of the entering photons, and also the electrons have radial momentum conservations and fully elastic bouncing between two atoms, in the new atom model. Conventional atom model must be criticized on the following four points. (1) Natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc. Because the radius of hydrogen atom's electron orbit is the order of 10$^{-11}$ m and the radia of the nucleons in the nucleus are the order of 10$^{-14}$ m and then the converging $\pi$-gamma rays to the nucleus have so great circular momentum, the electron can not have a circular motion. We can say without doubt that any elementary mass particle can have only linear motion, because of the $\pi$-rays'hindrances, nearthenucleus. (2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The h v is the kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not change during the transition from outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body. Conventional Concept of Electric Field must be extended in the case of the direct and alternating current. Conventional concept is based on coulomb's force while the electric potential in the direct and alternating current is from Gibb's free energy. And also conventional concept has not any consciousness with human being but the latters has a conscious sensibility. The cell emf is from the kinetic energy of the open $\pi$-rays flow through the conducting wire. The electric potential in alternating current is from that the trans-orbital moving of the induced change of magnetic field in the wire produces flows of open $\pi$-rays, which push the rotating electrons on the orbital and then make the current flow. Human consciousness can induce a resonance with the sensibility of the open $\pi$-rays in the electric measuring equipment. Specially treated acupunctures with Nasucon is for sending an acupunctural effect from one place to another via space by someone's will power.

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A study on the Frequency Analysis Function of the Auricle Using A Notch Filter

  • Park, Dong-Cheol
    • International journal of advanced smart convergence
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    • v.10 no.4
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    • pp.241-255
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    • 2021
  • The human auricle is the first part to receive sound from the outside. In this part, the frequency range of human recognizable form is divided and organized. In this study, we propose modeling by applying a single sound source to the surface of the human auricle. This means that when the sound pressure of a low frequency (low frequency) sound enters the pinna, the impedance felt at the tip of a part of the non-linear surface of the pinna is mainly due to the tensile force at the end of the part of the non-linear surface of the pinna. By expressing the situation of moving at a very small speed, the characteristic impedance of the pinna was confirmed to be negative infinity, and it was also confirmed that the speed at the tip of a part of the non-linear surface of the pinna was 0 in the anti-resonance state. It was found that the wave propagation phenomenon that determines the characteristics of the filter is determined by how large the wavelength, kL, is compared to the length of the tip of a part of the non-straight surface of the pinna. Humans first receive sounds from outside through their ears. The auricle is non-linear and has a curved shape, and it is known that it analyzes frequencies while receiving external sounds. The human ear has an audible frequency range of 20Hz - 20,000Hz. Through the study, we applied the characteristics of the notch filter to hypothesize that the human audible frequency range is separated from the auricle, and applied filter theory to analyze it, and as a result, meaningful results were obtained. The curved part and the inner part of the auricle function as a trumpet, collecting sounds, and at the same time amplifying the weak sound of a specific band. The point was found and the shape of the envelope detected in the auricle was found. Selectivity for selecting sounds coming from the outside is the formula of the pinna that implements the function of Q. The function of distinguishing human-recognizable sound from the pinna from low to high through frequency analysis is performed in the pinna, and the 2-3kHz area, where human hearing threshold is the most sensitive, is also the acoustic impedance of the most recessed area of the pinna. It can be seen that starting from.

Development of Simplified Immersed Boundary Method for Analysis of Movable Structures (가동물체형 구조물 해석을 위한 Simplified Immersed Boundary법의 개발)

  • Lee, Kwang-Ho;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.3
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    • pp.93-100
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    • 2021
  • Since the IB (Immersed Boundary) method, which can perform coupling analysis with objects and fluids having an impermeable boundary of arbitrary shape on a fixed grid system, has been developed, the IB method in various CFD models is increasing. The representative IB methods are the directing-forcing method and the ghost cell method. The directing-forcing type method numerically satisfies the boundary condition from the fluid force calculated at the boundary surface of the structure, and the ghost-cell type method is a computational method that satisfies the boundary condition through interpolation by placing a virtual cell inside the obstacle. These IB methods have a disadvantage in that the computational algorithm is complex. In this study, the simplified immersed boundary (SIB) method enables the analysis of temporary structures on a fixed grid system and is easy to expand to three proposed dimensions. The SIB method proposed in this study is based on a one-field model for immiscible two-phase fluid that assumes that the density function of each phase moves with the center of local mass. In addition, the volume-weighted average method using the density function of the solid was applied to handle moving solid structures, and the CIP method was applied to the advection calculation to prevent numerical diffusion. To examine the analysis performance of the proposed SIB method, a numerical simulation was performed on an object falling to the free water surface. The numerical analysis result reproduced the object falling to the free water surface well.

Investigation of Impact Factor Variation of Open-Spandrel Arch Bridges According to Spacing Ratio of Vertical Members (수직재 간격비에 따른 개복식 상로 아치교의 충격계수 변화 분석)

  • Hong, Sanghyun;Oh, Jongwon;Roh, Hwasung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.5
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    • pp.45-52
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    • 2020
  • An open-spandrel arch bridges, which consists of slab deck, arch rib, and vertical members, shows a various level of moment and axial forces according to the supporting boundary condition of arch rib and vehicle speeds. Also, the definition of impact factor accepts any kind of response parameters, not only displacement response at slab deck. The present study considers concrete open-spandrel arch bridges constrained with fixed conditions at the ends of arch rib and investigates the impact factor variation due to moving load speeds, response parameters, measuring locations, and vertical member spacing ratio of the bridges. The results of Reference model show that the impact factor is biggest when the reactive moment resulted at the vehicle-inducing opposite end of the arch rib is applied. The peak impact factor is a similar level obtained for the middle of the span adjacent to the slab deck center, but it is 19% higher than the peak impact factor calculated using the axial force developed at the same location. Reducing the spacing ratio of the vertical members as half as the reference model whose ratio is 1/9.375 produces a similar level of the moment-based peak impact factor compared to the reference model. However, when the spacing ratio is doubled, the peak impact factor is 4.4 times greater than the reference model.

A Study on the Buckling Stability due to Lateral Impact of Gas Pipe Installed on the Sea-bed (해저면에 설치된 가스관의 외부충격에 의한 좌굴 안전성 검토)

  • Park, Joo-Shin;Yi, Myung-Su
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.2
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    • pp.414-421
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    • 2022
  • Subsea oil and gas exploration is increasingly moving into deeper water depths, and typically, subsea pipelines operate under high pressure and temperature conditions. Owing to the difference in these components, the axial force in the pipe is accumulated. When a pipeline is operated at a high internal pressure and temperature, it will attempt to expand and contract for differential temperature changes. Typically, the line is not free to move because of the plane strain constraints in the longitudinal direction and soil friction effects. For a positive differential temperature, it will be subjected to an axial compressive load, and when this load reaches a certain critical value, the pipe may experience vertical (upheaval buckling) or lateral (snaking buckling) movements that can jeopardize the structural integrity of the pipeline. In these circumstances, the pipeline behavior should be evaluated to ensure the pipeline structural integrity during operation in those demanding loading conditions. Performing this analysis, the correct mitigation measures for thermal buckling can be considered either by accepting bar buckling but preventing the development of excessive bending moment or by preventing any occurrence of bending.

Dynamic analysis of a coupled steel-concrete composite box girder bridge-train system considering shear lag, constrained torsion, distortion and biaxial slip

  • Li Zhu;Ray Kai-Leung Su;Wei Liu;Tian-Nan Han;Chao Chen
    • Steel and Composite Structures
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    • v.48 no.2
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    • pp.207-233
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    • 2023
  • Steel-concrete composite box girder bridges are widely used in the construction of highway and railway bridges both domestically and abroad due to their advantages of being light weight and having a large spanning ability and very large torsional rigidity. Composite box girder bridges exhibit the effects of shear lag, restrained torsion, distortion and interface bidirectional slip under various loads during operation. As one of the most commonly used calculation tools in bridge engineering analysis, one-dimensional models offer the advantages of high calculation efficiency and strong stability. Currently, research on the one-dimensional model of composite beams mainly focuses on simulating interface longitudinal slip and the shear lag effect. There are relatively few studies on the one-dimensional model which can consider the effects of restrained torsion, distortion and interface transverse slip. Additionally, there are few studies on vehicle-bridge integrated systems where a one-dimensional model is used as a tool that only considers the calculations of natural frequency, mode and moving load conditions to study the dynamic response of composite beams. Some scholars have established a dynamic analysis model of a coupled composite beam bridge-train system, but where the composite beam is only simulated using a Euler beam or Timoshenko beam. As a result, it is impossible to comprehensively consider multiple complex force effects, such as shear lag, restrained torsion, distortion and interface bidirectional slip of composite beams. In this paper, a 27 DOF vehicle rigid body model is used to simulate train operation. A two-node 26 DOF finite beam element with composed box beams considering the effects of shear lag, restrained torsion, distortion and interface bidirectional slip is proposed. The dynamic analysis model of the coupled composite box girder bridge-train system is constructed based on the wheel-rail contact relationship of vertical close-fitting and lateral linear creeping slip. Furthermore, the accuracy of the dynamic analysis model is verified via the measured dynamic response data of a practical composite box girder bridge. Finally, the dynamic analysis model is applied in order to study the influence of various mechanical effects on the dynamic performance of the vehicle-bridge system.

A Study on University Library Development Plan: Focused on Rubric Evaluation (대학도서관 발전계획 분석 - 루브릭 평가를 중심으로 -)

  • Sun-Gu Jeon;Yong-Jae Lee
    • Journal of Korean Library and Information Science Society
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    • v.55 no.1
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    • pp.99-122
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    • 2024
  • The purpose of this study is to analyze domestic academic library development plans, check whether key components are reflected, and seek ways to improve the establishment of academic library development plans. To this end, a rubric evaluation technique derived from research related to evaluation of foreign universities and libraries was used. The libraries of the top 15 domestic universities were selected by referring to the QS World University Evaluation and THE World University Evaluation as the subjects of the study, and how much the core components of the development plan were reflected were evaluated. The results of the study are as follows. First, as a result of evaluating the university library development plan, most of the contents of 'purpose', 'goal', and 'action plan' were reflected, but vulnerabilities were found in 'mission' and 'vision'. Second, some private academic libraries were moving toward strategic planning at the level of advanced countries, including all of the core components. Third, although most academic libraries specified 'purpose', it showed limitations due to perfunctory description and connection. In the comprehensive evaluation, out of the highest score of 15, 12 were good and 3 were poor, indicating that the development plans of domestic academic libraries were generally at a 'good' level. As an improvement measure, it was suggested to form a task force for development plan establishment, to disclose and promote development plans, and to strengthen education on development plans for librarians.