• Title/Summary/Keyword: 다발 보

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Vibration Analysis of a Stacked beam Including Frictional Contact Force (마찰 접촉력을 고려한 다발 보(Stacked Beam)의 진동 해석)

  • 이기수;임철호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.8
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    • pp.1513-1518
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    • 1992
  • Numerical solution technique is suggested to analyze the vibration of a spring composed of stacked beams fastened together. Bernoulli-Euler beam theory for small deflection is used, and incremental Coulomb friction law is adopted for the interface friction. The validity of the present solution technique is checked for the perfectly bonded case and the perfect sliding case.

Seismic Performance of Special Reinforced Concrete Coupling Beams with Different Reinforcement Details (보강상세에 따른 특수전단벽 연결보의 내진성능)

  • Chun, Young-Soo;Park, Ji-Young
    • Land and Housing Review
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    • v.6 no.1
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    • pp.21-29
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    • 2015
  • Coupling beams posses proper strength, stiffness and ductility capacities to resist efficiently under seismic loads. The strength, stiffness and ductility capacities for special diagonally reinforced concrete coupling beam with a span-to-depth ratio 2.0 or less is higher than those of coupling beam with conventionally reinforced concrete coupling beam. However, diagonally reinforced detailing creates major construction problem. In this study, design alternatives for diagonally reinforced concrete coupling beams were experimentally investigated. The results show that angle reinforced coupling beam(specimen SA) exhibited a better stable behavior in comparison with non-diagonally coupling beams(specimens SB-series) and sustained corresponding drift ratio, peak-to-peak stiffness and cumulative dissipated energy in comparison to diagonally coupling beam(specimen CA).

MULTIPLE MYELOMA OF MANDIBLE : REPORT OF A CASE (하악골에 발생한 다발성골수종의 증례보고)

  • Jang, Hyun-Seok;Lee, Gi-Cheol
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.18 no.4
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    • pp.706-711
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    • 1996
  • 다발성 골수증은 다양한 증세를 보이는 형질세포로부터 기원하는 악성종양으로 40세이상의 남성에서 호발되며 alkylating agent 단독, 혹은 corticosteroid와 병용하는 항암제 치료로 생존율이 크게 증가되기는 하였지만 치료후 평균생존기간의 20개월 내외로 완치율이 그다지 높지않은 형편이다. 악골에서의 발생은 극히 드물고 대개 늑골, 편평골, 척추, 골반, 두개골등에 광범위한 patchy destruction의 형태로 나타나는데 악골에 발생할 경우 임상증상은 장기적인 무통성 종창이 가장 흔하며 때로는 동통, 악골의 팽창, 감각이상, 치아의 동요, 악골골절등을 보이기도 한다. 전신적증상으로 무력감, 체중감소, 빈혈, 신부전, hypercalcemia, hyperiviscosity syndrome을 나타내기도 하는데 약 10%의 환자에서 전신적인 amyloidosis를 보인다. 진단은 골수생검상 골수의 plasmacytosis가 10% 이상이면서 혈장이나 뇨전기영동법에서 monoclonal globulin peak이 있을 때 가능하다. 여러 학자들은 처음에는 독립적인 고립성병소로 나타났다가 장기적으로 다발성골수종으로 이행됨을 주장하면서 장기적인 추적을 권하고 있지만 골내 고립성 형질세포종(solitary plasmacytoma in bone), 수질외 형질세포종(extramedullary plasmacytoma) 등은 다발성골수종과는 다른 질환이라 주장하는 등 아직 많은 논란이 있는 형편이다. 치료는 $4000{\sim}6000$ rad의 방사선치료와 여러 가지 약제의 복합적인 항암요법이 사용되고 있으며 국소적인 병소의 경우 외과적 절제술이 추천되기도 한다. 저자들은 59세 여자환자에서 하악골에 발생된 다발성골수종을 치험하였기에 문헌고찰과 함께 보고하는 바이다.

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Electrophysiological Features of Diabetic Polyneuropathy: Motor Nerve Conduction Studies (당뇨병성다발신경병증의 전기생리학적 특징: 운동신경전도검사)

  • Kang, Ji-Hyuk;Lee, Yun-Seob
    • The Journal of the Korea Contents Association
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    • v.10 no.10
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    • pp.237-245
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    • 2010
  • Nerve conduction studies (NCS) are the most objective measure of nerve function and essential for the diagnosis of sub-clinical neuropathy in diabetes mellitus and diabetic polyneuropathy (DPN). This study evaluates the characteristic of electrophysiological abnormalities in DPN. Electrodiagnostic data from 120 patients with diabetic polyneuropathies and 77 control subjects were reviewed. Motor nerve conduction velocities (MNCV), distal motor latencies (DML), compound muscle action potential (CMAP) amplitudes, No potential frequency and conduction block were analyzed. Data were normalized based on normative reference values, and the proportion of nerves with abnormal values in the lower and upper limbs were evaluated. DPN was systemic demyelinating peripheral polyneuropathy and more severe abnormal nerve conduction was found in lower limbs than in upper limbs. The abnormal degree was more severe in peroneal nerve. It was no statistically significant difference of conduction block in control and DPN group. Our findings suggest that DPN had more common and severe peroneal nerve involvement in the motor nerve conduction studies (MNCS). These findings have important implications for the electrophysiological evaluation of DPN.

Arthroscopic Double-Bundle Posterior Cruciate Ligament Reconstruction (관절경적 이중다발 후방십자인대 재건술)

  • Chun, Churl Hong;Kim, S.H.
    • Journal of the Korean Arthroscopy Society
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    • v.15 no.2
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    • pp.140-145
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    • 2011
  • 후방십자인대 손상의 이상적 치료는 아직까지도 확립되지 않았다. 과거 몇 십 년간 후방십자인대에 대한 지식과 슬관절 안정성에 대한 후방십자인대의 생역학에 대한 지식이 증가하였다. 특히 이중 다발에 대한 지식이 증가하고 이러한 모든 노력들은 후방십자인대의 해부학적인 특징을 최대한 복원하기 위해 이루어졌다. 재건술의 수술 방법은 특정 손상 양상에 따라 그에 맞게 이루어지는데 만성 손상의 경우나 remnant가 거의 존재하지 않는 경우에는 이중 다발을 재건하는 것이 만족스러운 결과를 보인다. 아직까지 이중 다발 후방십자인대 재건술의 결과에 대해서는 논란이 많은 것은 사실이나 장기 추시가 가능해지면 이중 다발 후방십자인대 재건술이 해부학적으로나 생역학적으로 더욱 정상에 가깝기 때문에 더 나은 장기적 결과를 보여줄 것으로 예상된다.

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CANFLEX 연료봉 다발의 진동특성

  • 박진석;정장환
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05d
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    • pp.306-311
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    • 1996
  • CANFLEX 연료봉 다발을 구성하는 우라늄 펠릿이 장전된 핵연료봉의 공기중 진동특성을 진동 실험과 유한요소 해석을 통하여 구하였다. 유한요소 해석 시에는 우라늄 펠릿의 강성은 무시하고 질량은 지르칼로이 튜브에 부가하며, 연료봉 양단의 용접부위를 단순 지지보로 처리하는 모델을 제시하였다. 이 모델로부터 얻은 해석결과를 진동실험에서 구한 측정값과 비교하였다.

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Medial Longitudinal Fasciculus on MRI in a Patient with Internuclear Ophthalmoparesis: A Case Report (신경핵사이 눈근육마비환자에서 자기공명영상에서의 내측세로다발: 증례 보고)

  • Kim, Sung Min;Kim, Ho Kyun;Lee, Hui Joong
    • Investigative Magnetic Resonance Imaging
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    • v.18 no.2
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    • pp.167-170
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    • 2014
  • The medial longitudinal fasciculus (MLF) is myelinated composite tract, lying near the midline, ventral to periaqueductal grey matter that plays a key role in coordinating eye movements. A lesion of the MLF results in an ipsilateral adduction deficit and a contralateral abducting nystagmus, referred to as an internuclear ophthalmoparesis. The blended tract with adjacent white matter in pons and midbrain is indistinguishable on brain imaging such as CT and MRI. Until now, to the best of our knowledge, MLF is not delineated on in vivo MRI. We present a case showing the whole connecting courses of MLF lesion on MRI in a patient with inflammatory demyelinating disorder.

MRI Features of Multiple Cranial Neuropathies in Guillain-Barré Syndrome Occurring after COVID-19 Vaccination: A Case Report (COVID-19 백신 접종 후 발생한 길랑-바레증후군에서 보이는 다발성 뇌신경병증의 MRI 소견: 증례 보고)

  • Youngsoo Soh;Eun Ae Yoo;Eun-Sil Kim;Soo Jung Kim
    • Journal of the Korean Society of Radiology
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    • v.84 no.4
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    • pp.964-969
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    • 2023
  • Guillain-Barré syndrome (GBS) is an immune-mediated demyelinating polyneuropathy characterized by progressive, ascending, and symmetrical paralysis. It is known to be triggered by an antecedent infection or vaccination. Recently, GBS development following coronavirus disease 2019 (COVID-19) vaccination has been reported. Cranial neuropathies in typical GBS patients usually involve the facial and the lower cranial nerves (from IX to XII). We report a rare case of multiple cranial neuropathies involving trigeminal, abducens, and facial nerves in a patient who developed GBS following COVID-19 vaccination on the basis of obvious MRI features.

Organic fiber reinforcement for Performance improvement of Blast resistance and Flexural Performance Evaluation of Fiber reinforced concrete using organic fiber reinforcement (방폭 성능 강화용 유기계 섬유보강재 제조 및 이를 혼입한 섬유보강 콘크리트의 휨성능 평가)

  • Jeon, Chanki;Jeon, Joongkyu;Kim, Sungil;Kim, Kihyung
    • Journal of the Society of Disaster Information
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    • v.11 no.2
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    • pp.211-218
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    • 2015
  • This study propose the organic fiber reinforcement for performance improvement of blast resistance. Proposed fibers are polyamide fiber, PET fiber and aramid fiber and fiber reinforcements were produced by ATY method. To evaluate strain energy absorption capacity of organic fiber reinforced concrete using organic fiber reinforcement, 4-point bending test and 3-point bending tests on notched beam were performed. Test results show that PET fiber reinforced concrete has outstanding performance. It is thought that the PET fiber is effective for the performance improvement of blast resistance.

Evaluation of Reinforcement Detail Effect on Coupling Beams (연결보의 배근 상세 효과 평가)

  • Lee, Hyun-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.2
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    • pp.49-57
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    • 2021
  • A study was conducted to secure structural performance as well as improve workability by improving the reinforcement details of special shear wall and coupling beams. Based on the specimen in which the existing diagonal bundle reinforcement and shear reinforcement were placed, the specimens replaced with thick diagonal reinforcing bars and the specimens replaced with horizontal reinforcing bars were selected as variables. As a result of the experiment, the specimen, which replaced the existing diagonal reinforcement with a thick-diameter reinforcement, showed a similar behavior to that of the basic specimen, and it was evaluated that it can be applied as an alternative to the details.