• 제목/요약/키워드: joint stability

검색결과 893건 처리시간 0.027초

GIS와 지구통계학을 이용한 충주호 남부지역의 광역적인 사면안정평가 (Regional Evaluation of Slope Stability by Using GIS and Geostatistics Around the Southern Area of Chungju Lake)

  • 문상기
    • 자원환경지질
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    • 제33권2호
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    • pp.117-128
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    • 2000
  • Regional evaluations of slope stability by the failure criterion and by environmental geological factors were conducted. The failure criterion is the general conditions for plane failure which consider the geometrical conditions between geological discontinuities and topographical slope planes. The factor focused in this condiction is dip and dip direction. Geostatics, named semivariogram was used for establishing structural domains in slope stability evaluation by the failure criterion. The influential range was calculated to 6 km in the case of dip direction of dominant joint set and 7 km in the case of dip of the same dominant joint set. Then applying this failure criterion to the study area produced a slope stability map using the established domains and slopes generated by TIN module of ARC/INFO GIS. This study considered another regional slope stability analysis. 5 failure-driven factors 9the unstable slope map, geology, engineering soil, groundwater, and lineament density) were selected and used as data coverages for regional slope stability evaluation by geoenvironmental factors. These factors were weighted and overlayed in GIS. From the graph of cumulatave area (%) and instability index, finding critical points classified the instability indices. The most unstable slopes are located in the southern area of Mt. Eorae, Dabul-ri, and the eastern area of Junkok-ri in the first area is plane failure. Also, the expected orientations of failure are 59/338 and 86/090 (dip/dip direction).

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복합말뚝 연결부 안정성 평가 및 수평거동특성 분석 (Joint Stability and lateral behavior of composite piles)

  • 신윤섭;박재현;황의성;조성한;정문경;부교탁
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.553-558
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    • 2010
  • The behavior of composite piles composed of steel pipe pile in the upper part and concrete pile in the lower part by a mechanical splicing joint was examined by field lateral load tests and bending tests. A total of 7 piles including two instrumented piles for bending test were installed. The soil profile consists of soft clay with weak silt with shallow groundwater level. Laboratory tests were carried out to determine the basic soil characteristics and the strength parameters. This paper presents the composite pile behavior with various portions of the upper steel pile: 0, 20, 30, and 45% of the pile embedded pile length. Three-point bending tests were performed to investigate the stress-strain relation at the mechanical joint. Based on these test results, the behavior of composite piles with various upper steel pile length are evaluated and the stability of mechanical joints are examined. Through comparisons with results of field load tests, it was found that lateral load carrying capacity of the composite piles increased and deflections of the composite piles decreased with increasing the upper steel piles. The mechanical joint was proved to retain its structural stability against the tested load conditions. Economical benefits of composite pile of this kind can be gained by setting adequately the length of the upper steel pipe piles.

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Horizontal instability after acromioclavicular joint reduction using the two-hole technique is preferred over the loop technique: a single-blind randomized clinical trial

  • Mardani-Kivi, Mohsen;Asadi, Kamran;Leili, Ehsan Kazemnejad;Hashemi-Motlagh, Keyvan;Izadi, Amin;Pishgahpour, Mona;Darabipour, Zohre
    • Clinics in Shoulder and Elbow
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    • 제25권3호
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    • pp.224-229
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    • 2022
  • Background: Most acromioclavicular joint (ACJ) injuries are caused by direct trauma to the shoulders, and various methods and techniques are used to treat them; however, none of the options can be considered the gold standard. This study examines the horizontal stability of the ACJ after a complete dislocation was repaired using one of two Ethibond suture techniques, the loop technique and the two holes in the clavicle technique. Methods: In this single-blind, randomized clinical trial, 104 patients diagnosed with complete ACJ dislocation type V were treated using Ethibond sutures with either the loop technique or the two holes in the clavicle technique. Horizontal changes in the ACJ were radiographically assessed in the lateral axial view, and shoulder function was evaluated by the Constant (CS) and Taft (TS) scores at intervals of 3, 6, and 12 months after surgery. Results: The horizontal stability of the ACJ was better with the two-hole technique than the loop technique at all measurement times. CS and TS changes showed a significant upward trend over time with both techniques. The mean CS and TS at the final visit were 95.2 and 11.6 with the loop technique and 94.0 and 11.9 with the two-hole technique, respectively. The incidence of superficial infections caused by the subcutaneous pins was the same in the two groups. Conclusions: Due to the improved ACJ stability with the two-hole technique, it appears to be a more suitable option than the loop technique for AC joint reduction.

견관절의 관절 기계적수용기 (Joint mechanoreceptors of shoulder)

  • 권오현;육군창;배성수
    • The Journal of Korean Physical Therapy
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    • 제15권2호
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    • pp.12-18
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    • 2003
  • Proprioception can be defined as a specialized variation of touch that encompasses the sensation of joint movement(kinesthesia) and joint position(static joint position sense). Several types of joint and muscular mechanoreceptors provide proprioceptive information for joint stability. Joint mechanoreceptors have been classified into four types based of activation characteristics : Ruffini endings, Pacinian corpuscles, Golgi tendon organlike endings, free nerve endings. The paper review the morphology, distrubution, function of mechanoreceptors in shoulder joint.

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보행 중 인체 슬관절의 3차원 접촉 모델 개발 (Development of Three-Dimensional Contact Model of Human Knee Joint During Locomotion)

  • 김효신;박성진;문정환
    • 한국정밀공학회지
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    • 제22권11호
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    • pp.182-189
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    • 2005
  • The human knee joint is the intermediate joint of the lower limb that is the largest and most complex joint in the body. Understanding of joint-articulating surface motion is essential for the joint wear, stability, mobility, degeneration, determination of proper diagnosis and so on. However, many studies analyzed the passive motion of the lower limb because of the skin marker artefact and some studies described medial and lateral condyle of a femur as a simple sphere due to the complexity of geometry. Thus, in this paper, we constructed a three-dimensional geometric model of the human knee from the geometry of its anatomical structures using non-uniform B-spline surface fitting as a study for the kinematic analysis of more realistic human knee model. In addition, we developed and verified 6-DOF contact model of the human knee joint using $C^2$ continuous surface of the inferior region of a femur, considering the relative motion of shank to thigh during locomotion.

암석절리와 균열망내에서의 채널흐름에 관한 이론적 수치해석적 연구 (A Theoretical and Numerical Study on Channel Flow in Rock Joints and Fracture Networks)

  • 송명규;주광수
    • 터널과지하공간
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    • 제4권1호
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    • pp.1-16
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    • 1994
  • The study on the flow characteristics and analysis of groundwater in discontinuous rock mass is very important, since the water inflow into the underground opening during excavation induces serious stability and environmental problems. To investigate the flow through single rock joint, the effect of various aperture distribution on the groundwater flow has been analyzed. Observed through the analysis is the "channel flow", the phenomenon that the flow is dominant along the path of large aperture for given joint. The equivalent hydraulic conductivity is estimated and verified through the application of the joint network analysis for 100 joint maps generated statistically. Both the analytic aproach based on isotropic continuum premise and the joint network analysis are tested and compared analyzing the gorundwater inflow for underground openings of different sizes and varying joint density. The joint network analysis is considered better to reflect the geometric properties of joint distribution in analyzing the groundwater flow.ater flow.

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A Study on Joint Resistance between Nb-Ti Superconducting Wires for MRI Magnet

  • Oh, Sang-Soo;Yingming Dai;Ha, Dong-Woo;Jang, Hyun-Man;Ryu, Kang-Sik
    • Journal of Electrical Engineering and information Science
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    • 제2권6호
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    • pp.90-94
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    • 1997
  • The joints between the superconducting wires are inevitably needed from the requirement of a high magnetic stability with respect to time in the superconducting MRI magnet. In this study, a new superconducting joint using Cu/Nb-Ti sleeve has been tried on the MRI type Nb-Ti superconducting wires. The transformer induction type apparatus was made and applied to measure the joint resistance. A very low joint resistance of 10\ulcorner $\Omega$ could be successfully obtained from this joint method. It was confirmed that the initial rapid current decay occurs before the very stable current decay due to only superconducting joint. Some unstable part in the joint like exposed filaments causes the initial induced current to lower and influence on the increase of the joint resistance.

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2차의 리아프노프 함수에 의한 유연 조인트 로봇의 비선형 견실제어기 설계 (Nonlinear robust control design with quadratic Lyapunov function for robots with joint elasticity)

  • 김동환;이교일
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.573-576
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    • 1996
  • We propose robust control scheme for flexible joint manipulator in the presence of nonlinearity and mismatched uncertainty. The control is designed based on Lyapunov approach. The robust control which is based on the computed torque scheme and state transformation via implanted control is introduced. The design procedure starts with the construction of linearized subsystems via the computed torque method and then uses state transformation. With this approach we do not impose an upper-bound constraint on the inertia matrix in case it is known. Thus, this control can be applied to arbitrary manipulators. The resulting robust control guarantees practical stability for both the transformed system and the original system. The transformation is only based on the possible bound of uncertainty.

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계산 방법론에 따른 용접부 응력 평가 및 비교(FE 상세 모델 vs 수 계산) (Stress Comparison on Welded Connection between Detail FE Model and Classical Calculation)

  • 송문성;정상웅
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.621-626
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    • 2010
  • According to development of method and device of Finite Element Analysis, the strength of welded joint is demonstrated by Finite Element Analysis not classical calculations. On the FEA, all of the joints for carbody are assumed to be ideal connections and the yield stress of welded joint is assumed to be the same to base metal. On these assumption, FEA is appropriate to evaluate the overall stability and strength of whole carbody. The classical calculation is appropriate to evaluate strength of specific welded joint and to determine the weld method and properties. Some project request strength calculation of the specific welded joints in addition to FEA, because of the demonstration of stability. The objective of this paper is the check of the consistency of the FEA result for the welded joints by the stress comparison between Detailed FE Model and classical calculation and the evaluation of the reliability of FEA result.

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장기 대기확산 모델용 안정도별 풍향·풍속 발생빈도 산정 기법 (The Joint Frequency Function for Long-term Air Quality Prediction Models)

  • 김정수;최덕일
    • 환경영향평가
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    • 제5권1호
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    • pp.95-105
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    • 1996
  • Meteorological Joint Frequency Function required indispensably in long-term air quality prediction models were discussed for practical application in Korea. The algorithm, proposed by Turner(l964), is processed with daily solar insolation and cloudiness and height basically using Pasquill's atmospheric stability classification method. In spite of its necessity and applicability, the computer program, called STAR(STability ARray), had some significant difficulties caused from the difference in meteorological data format between that of original U.S. version and Korean's. To cope with the problems, revised STAR program for Korean users were composed of followings; applicability in any site of Korea with regard to local solar angle modification; feasibility with both of data which observed by two classes of weather service centers; and examination on output format associated with prediction models which should be used.

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