• 제목/요약/키워드: Mass movement

검색결과 538건 처리시간 0.025초

측방변형을 일으키는 모래지반속의 H형 말뚝에 작용하는 수평력 (Behavior and Lateral Force of H-piles under lateral Soil Movement in Sand)

  • 김영인
    • 한국해양공학회지
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    • 제16권6호
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    • pp.44-48
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    • 2002
  • In lateral ground flow, slope stability, and land slide problems, H-piles have often been used, on a horizontally deforming ground, to prevent the failure of mass of soil in a downward and outward movement of a slope. Here, theoretical equations are derived to estimate the lateral force, assuming that the Mohr-Coulomb's plastic states occur in the ground, just around H-piles. In this study, some model experiments were performed to check the lateral forces determined from theoretical equations, using several pile widths, heights and various interval ratios between H-piles for sand specimens. The solution of the theoretical equation, derived from previous studies, showed reasonable characteristics for constants of soil, as well as for the interval, widths, and heights of H-Pile.

생후 1년 동안의 정상 운동 발달 (Normal Movement Development during the First of Life)

  • 김미현;배성수
    • The Journal of Korean Physical Therapy
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    • 제5권1호
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    • pp.71-77
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    • 1993
  • The baby makes very great strides in the first year of his life. The developmental principles may be summarised as follows : first, the continuous process from conception to maturity, second, the physical manifestation of neural maturation, third, the cephalocaudal direction, from proximal to distal, fourth generalized mass activity to specific individual responses, fifth, reflex dominance to integration. The stages of normal movement development an head control, rolling creeping(on belly), sitting crawling(on hands and on knees), standing and walking. The knowledge of normal movement development needs for the assessment treatment and management of C.N.S. injuried infant.

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충남 천안 구룡천 하류부 안골유역의 최종빙기 이후 사면물질이동 (Mass-Movement of Slope Material Since the Last Glacial Period at Angol Basin within Downstream Area of Gurongcheon in Cheonan, Choongnam Province)

  • 박지훈;박경
    • 한국지형학회지
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    • 제17권3호
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    • pp.31-47
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    • 2010
  • 구룡천 하류의 안골유역에 있어서 최종빙기 이후 유역을 구성하고 있는 구릉사면에서 기원한 사면물질이동의 이력을 구명하였다. 이를 위하여 층상해석·층서해석, 탄소연대측정, 입도분석, 대자율분석 및 안골유역의 지형분석을 실시하였다. 약 40,480~9,850yrBP에 걸쳐서 안골유역의 구릉사면에서 유역의 곡저로 이동·퇴적된 사면기원 무기물층의 사면물질이동은 최소 5회가 존재했으며, 약 9,850yrBP~현재까지 조사유역에서 발생한 사면물질이동은 적어도 4회가 있었다. 퇴적상 연구결과는 대자율 분석과 입도분석의 결과와도 조화롭게 나타나고 있다. 본 연구의 결과는 향후 천안 일대 소유역에 있어서 구릉사면의 삭박과정 및 최종빙기 이후 기후변화 복원에 유용한 자료가 될 것이며 나아가 우리나라 다른 지역연구를 위한 유용한 사례연구가 될 것이다.

크랭크 핀의 질량관성을 고려한 엔진 베어링의 틈새 거동 연구 (Study on the Dynamic Behaviors of Engine Bearing with the Inertia Effect of Crank Pin Journal)

  • 장시열
    • Tribology and Lubricants
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    • 제21권1호
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    • pp.39-45
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    • 2005
  • Investigation of the mass effect on the journal traces in the clearance of engine bearing has been performed for better design of mass distribution of crank system components such as crank pin, piston, con-rod, balance weight, crank throw weight, etc. as well as for better oil reaction behaviors to the applied forces from the cylinder pressures on the bearing. In this preliminary study, crank pin traces in the engine bearing clearance are computed by varying the equivalent magnitude of crank pin mass that includes the masses of crank pin, piston, con-rod. etc.. while most previous studies regarding journal traces in the bearing clearance neglect the inertia effects of crank pin mass. Although the inertia effect of pill mass is negligibly small compared to viscous force by ${\pi}bearing$ theory, it is found that it gives a great amount of influences on the journal traces in full bearing computation $(2\pi\;bearing\;theory)$ under the dynamic loading conditions.

Currarino Triad

  • Lee, Ho-Jin;Kong, Min-Ho;Kim, Dong-Seok;Kim, Tae-Sung
    • Journal of Korean Neurosurgical Society
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    • 제37권1호
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    • pp.63-66
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    • 2005
  • The authors report a case of Currarino triad which had a congenital anorectal stenosis associated with a sacral defect and a presacral mass. A 1-year-old female presented with constipation since birth. Neurological deficits were not found on admission. She had had a diverting colostomy due to anorectal stenosis at another hospital before admission. Lumbar X-ray films showed bony defect caudal to the third sacral vertebra. Magnetic resonance image demonstrated a round cystic pelvic mass which was connected with a dural sac via anterior sacral defect. Posterior approach with Intradural removal of the presacral cystic mass was performed and followed by anoplasty by a pediatric surgeon. The cystic mass was verified histologically as mature teratoma with cystic change. Postoperatively, the urinary function and bowel movement remained intact. Currarino triad should be suspected and evaluated physically and radiographically in a case of congenital anorectal stenosis. Prompt recognition and close cooperation between pediatric surgeons and neurosurgeons is advisable to ensure adequate surgical treatment.

Added Mass Estimation of Square Sections Coupled with a Liquid Using Finite Element Method

  • Jeong, Kyeong Hoon;Jhung, Myung Jo
    • Nuclear Engineering and Technology
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    • 제49권1호
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    • pp.234-244
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    • 2017
  • Natural frequencies of immersed square sections decrease due to a contribution of added mass to the movement of square sections. In this study, natural frequencies of square sections are obtained as a function of gap size between the square section and a rigid square wall using the finite element method. Additionally, they are used to extract the added mass effect on translational and rotation motions. Published information and studies on the translational and torsional vibration of square beams are also examined for practical use. D coupling of a square section is also investigated for multiple square sections. The suggested added mass estimation can be applicable to the spent fuel storage design of a pressurized light water modulated nuclear power plant.

건강한 노인과 뇌졸중 노인의 일어서기 동작 수행 시 운동학적 특성 연구 (Kinematic Analysis of Rising from a Chair in Healthy and Stroke Subjects)

  • 유연주;임비오
    • 한국운동역학회지
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    • 제17권2호
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    • pp.103-112
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    • 2007
  • The purpose of this study was to investigate the kinematic characteristics during rising from a chair. Six stroke patients and three healthy subjects participated in the study. Three dimensional kinematic analysis was used to get the duration, center of mass, and lower extremity angle. The stroke patients performed longer duration(0.28sec) than the healthy subjects in rising from a chair. The stroke subjects stayed longer time than the healthy subjects did in phase 2(From the initiation of knee extension to the reversal of trunk flexion to trunk extension)(t=-1.01, p=.04). The healthy subjects showed longer time than the stroke subjects in phase 3(from the reversal of trunk motion to extension to full standing position). The healthy subjects displayed larger value of center of mass in anterioposterior direction than stroke subjects(t=5.79, p=0.05). The center of mass in the mediolateral direction did not change during the completion of movement. However, the center of mass in the anterioposterior direction began to increase throughout the completion of movement. The center of mass in the vertical direction increased extensively in phase 3. The significant difference was not found in the maximum dorsiflexion in ankle, the initiation angle of knee, and the minimum angle of hip between stroke and healthy subjects. Even though statistical results did not show any significant angle difference in the lower extremity, the patterns of the change in the knee and hip angle during rising from a chair were different. The stroke subjects showed smaller angle of knee extension than the healthy subjects in phase 3. The stroke subjects flexed their trunk more than the healthy subjects in phase 2.

국립공원 이용행태 및 쓰레기 처리를 위한 Clean-up Time 운영에 대한 이용자의 인식 - 내장산 국립공원을 중심으로 - (Visitors' Cognitions of Clean-up Time Movement for Waste Treatment and Use Begavior in Naejangsan National Park)

  • 김용근;최성식;조중현
    • 한국환경생태학회지
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    • 제10권1호
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    • pp.14-23
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    • 1996
  • 내장산 국립공원의 이용객 행태조사는 1995년 10월 31일부터 11월 3일까지 실시되었고 총 151명의 이용객이 참여하였다. 이용객의 사회경제적 특성으로는 남자가 55%, 여자가 45%로 나타났으며, 교육정도는 대졸 이상이 52%로 높게 나타났다. 연령별로는 20대가 61.3%로 가장 높게 나타났다. 응답자의 가을철 내장산 국립공원의 방문목적은 주로 단풍감상을 위한 것으로 나타났다. 이용객 대부분은 이용정보를 안내판을 통해서(31.8%), 또는 그들 스스로 알아서(29.1%)획득하는 것으로 나타났다. 또 이들 대부분은 Clean-up Time 운동에 대해 알지 못하고 있었고, 현수막을 본 후에 인식하게 된 것으로 나타났다. 대부분의 이용객은 내장산에서 안내방송을 듣지 못했다고 응답한 반면, 국립공원에서 안내방송의 필요성에 대해서는 깊이 공감하는 것으로 나타났다. 이러한 결과들은 Clean-up Time 운동의 쓰레기 투기행위 관리효과에 대해 내장산 국립공원을 방문한 이용객들이 긍정적으로 인식하고 있다는 점을 나타내는 것으로 판단된다. 이러한 점에서 국립공원에 있어서 대중매체를 이용한 훼손행위 관리기법의 도임은 많은 효과를 가져다줄 것으로 기대된다.

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질량-스프링 모델을 이용한 해수 중 오탁방지막 거동해석 (Behavioral Analysis of Silt Protectors in Seawater Using the Mass-Spring Model)

  • 이춘우;김옥삼;신현출;황두진
    • 해양환경안전학회지
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    • 제23권2호
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    • pp.194-199
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    • 2017
  • 오탁방지막이 바닷물 속에 설치되어 있을 때 조류와 파도가 변할 때 움직임과 앵커 파주력을 초과하는 유체력이 작용할 경우의 이동 메카니즘을 질량-스프링법으로 해석하였다. 설치 위치는 전남 진도군 임회면 굴포리 동령개 포구 해역이다. 앵커의 파주력을 초과하는 장력은 0.05 m/s에서는 318초 후에 도달하였고, 0.15 m/s에서는 77초, 0.25 m/s에서는 43초, 0.3 m/s에서는 37초 후에 앵커가 움직이기 시작하여, 조류 속도가 0.01 m/s로 증가함에 따라서 평균 11.2 초 정도, 앵커 이동시작 시간이 단축되고 있었다. 조류만 작용할 때와 파랑이 추가될 때의 차이점은 유속이 느릴 경우, 앵커의 이동이 시작되는 시간의 차이가 7.6 % 정도 발생하였으나, 유속이 빠른 경우는 4.3 % 미만으로 큰 차이가 없이 앵커 이동이 시작되는 것을 알 수 있었다. 조류 속도가 0.13 m/s를 초과하고 파도의 방향이 일치하면 주변의 해저 구조물과의 충돌로 인해 오탁방지막 성능이 정상적으로 작동하지 않을 수 있으니, 오탁방지막을 바다에 설치할 때 해수의 흐름 상황 등을 질량-스프링 방법으로 면밀하게 검토해야 한다.

제1기계시대 건축디자인에서의 운동의 표현에 관한 연구 (A Study on the Expression of Movement in Architectural Design in the first Machine Age)

  • 김원갑
    • 한국실내디자인학회논문집
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    • 제14권1호
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    • pp.28-36
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    • 2005
  • The theme of modern architecture was various expression of dynamism and the flow of space. It was because that the space become the main theme of architecture since the late 19th century, and the space was changed from the 3rd dimension into the 4th dimensional space-time continuum. Though many avant-garde artists in the early 20th century did not understand the theory of relativity, they became conscious of the concept of space-time continuum, and tried to express the movement as the duration in time which Bergson defined. Many architects in the first machine age conceived the movement of architecture, and understand it as the dynamism of the mass and in the space. But especially, Sant'Elia and Hilberseimer expressed it as the flow of various force and vector In the metropolis as entire system. And Some architects conceived it as real movement of the building and expressed it as the rotary motion of building, movable partition and furniture, mobile prefabricated building. This study analyzed the expression of movement in architecture in the first machine age.