• Title/Summary/Keyword: 근 손상

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Implications of the effects of gravity load for earthquake resistant design of multistory building structurtes (고층건물의 내진설계에 미치는 중력하중의 영향)

  • 이동근;이석용
    • Computational Structural Engineering
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    • v.6 no.3
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    • pp.67-80
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    • 1993
  • This paper presents the results of an analytical study to evaluate the inelastic seismic response characteristics of multistory building structures, the effects of gravity load on the seismic responses and its implications on the earthquake resistant design. Static analyses for incremental lateral force and nonlinear dynamic analyses for earthquake motions were performed to evaluate the seismic response of example multistory building structures. Most of considerations are placed on the distribution of inelastic responses over the height of the structure. When an earthquake occurs, bending moment demand is increased considerably from the top to the bottom of multistory structures, so that differences between bending moment demands and supplies are greater in lower floos of multistory structures. As a result, for building structures designed by the current earthquake resistant design procedure, inelastic deformations for earthquake ground motions do not distribute uniformly over the height of structures and those are induced mainly in bottom floors. In addition, gravity load considerded in design procedure tends to cause much larger damages in lower floors. From the point of view of seismic responses, gravity load affects the initial yield time of griders in earlier stage of strong earthquakes and results in different inelastic responses among the plastic hinges that form in the girders of a same floor. However, gravity load moments at beam ends are gradually reduced and finally fully relaxed after a structure experiences some inelastic excursions as a ground motion is getting stronger. Reduction of gravity load moment results in much increased structural damages in lower floors building structures. The implications of the effects of gravity load for seismic design of multistory building structures are to reduce the contributions of gravity load and to increased those of seismic load in determination of flexual strength for girders and columns.

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All-inside Arthroscopic Capsular Imbrication and Lateral Release in Patellofemoral Instability (Operative technique) (슬개대퇴관절 불안정성에서의 관절경적 All-inside 관절막 중첩술 및 외측 지대 유리술 (수술 술기))

  • Kim, Jae-Hwa;Cho, Duck-Yun;Yoon, Hyung-Ku;Kim, Jung-Ryul
    • Journal of the Korean Arthroscopy Society
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    • v.10 no.1
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    • pp.118-122
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    • 2006
  • Purpose: We introduce a technique of all inside arthroscopic capsular imbrication and lateral release used to treat patellofemoral instability. Methods: With the arthroscope in the anteromedial portal for best viewing, the arthroscopic scissor is placed through superolateral portal for proximal to distal release. The release performed 5mm to 1cm from the edge of the patella. After completion of the procedure, with the arthroscope in anterolateral portal, we inserted 5mm cannula in superolateral portal and made working portal from superomedial portal. Medial reefing was performed with all inside technique by using curved needle of the spectrum suturing system and No. 1 monofilament PDS suture is passed through the superomedial portal percutaneously and retrieved through a superolateral portal. Conclusion: Several methods for arthroscopic patella realignment have been proposed, but they have consisted primarily of arthroscopically assisted techniques using a medial incision. We believe that our procedure is preferable to arthroscopically assisted methods commonly used, in that an incision is avoided and the vastus medialis obliqqus is not violated. Our technique is minimally invasive and is easy to control the tightness of the medial patellofemoral ligament (MPFL) under direct vision.

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Evaluation on the Effectiveness of Supplementary V-ties on Flexural Ductility of Reinforced Concrete Columns (철근콘크리트 기둥의 휨 연성에 대한 V-타이 보조띠철근의 효율성 평가)

  • Lee, Hye-Jin;Yang, Keun-Hyeok;Kwak, Min-Kyoung
    • Journal of the Korea Concrete Institute
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    • v.29 no.4
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    • pp.345-351
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    • 2017
  • This study evaluated the effectiveness of V-shaped ties as an alternative to the supplementary crossties specified in ACI 318-14 on the flexural ductility of reinforced concrete columns. From column specimens tested under constant axial loads and reversed cyclic lateral loads, the mode of failure and lateral load-lateral displacement relationship were measured according to the variation of the applied axial load levels. After the columns reached the peak lateral load capacity, the $90^{\circ}$ hooks of the crossties gradually opened, which eventually caused premature buckling of the longitudinal reinforcement and severe crushing of the core concrete, whereas no V-ties were extracted from the core concrete until the column failure. As a result, the cumulative work damage indicators up to 80% of the peak lateral load for V-tie columns under the axial load level of 0.2, 0.4, and 0.55 was as much as 2.4, 2.3, and 5.2 times higher, respectively, than those of the companion crosstie columns. The superiority of the V-ties to the conventional crossties in enhancing the flexural ductility of columns became more prominent as the axial load level increases.

The clinical study on 37 cases of whiplash injury patients which caused by traffic accident (교통사고(交通事故)로 인한 편타성(鞭打性) 손상(損傷) 환자(患者) 37례(例)에 대한 임상연구(臨床硏究))

  • Kang, Jae-Hui;Jang, Suk-Geun;Lee, Hyun;Lee, Byung-Ryul
    • Journal of Acupuncture Research
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    • v.19 no.3
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    • pp.180-191
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    • 2002
  • Objective : This study was performed to evaluate the effect of oriental medical treatment in whiplash injury patients which caused by traffic accident. Methods : The clinical study was carried out 37 cases of whiplash injury patients which had been admitted in Daejon university Cheon-an oriental hospital from June, 2001 to December, 2001. Results : l. In the distribution of sex distinction was female much more than male in the ratio of 3:2 and thirties was most in age distribution. 2. In situation of traffic accident, The most case was rear-ending(70.27%). 3. Except cervical pain or it's reffered pain, there were whole body symptoms as fallow, insomnia in 11cases(29.73%), night pain in 10 cases(27.03%), general body pain in 8cases(21.62), dizziness in 6cases(16.22%). 4. According to Meridian Muscle theory, a injured parts of patient were devided as follows. There were 22cases(59.46%) which have injury in Bladder, Small Intestine Meridian Muscle, 10cases(27.03%) in Gallblader, Triple Energizer Meridian Muscle, 5cases(13.51%) in Stomach, Large Intestine Meridian Muscle. 5. There were 6cases(16.22%) of the grade of complete recovery, 10cases(27.03%) of the grade of excellent, 12cases(32.43%) of the grade of improvement, 6cases(16.22%) of the grade of disimprovement and 3cases(8.11%) of the grade of poor. So 28cases(75.68%) were efficacious. 6. Generally Herb-meds that have efficacy of Geo-Eohyeol were most used(27cases, 72.97%) in early stage. Secondly Herb-med that have efficacy of Yiqi-sunqi were used(20case, 54,05%) in middle stage and Herb-med of Bo-Qiheol were used(l0cases, 27.03%) in latter term. The most used Herb-med was Hoisu-san, Oyaksungi-san(22cases, 54.96%). 7. In l5cases which have Aqua-Acupuncture treatment, There were 3cases of Complete recovery, 5cases of Excellent, 4cases of Improvement, 2cases of Disimprovement, 1cases of Poor. 8cases(53.33%) were above Excellent grade, so it is more efficatious Than simple treatment without Aqua-Acupuncture(36.37%). 8. The improvement of Bladder, Small Intestine Meridian Muscle was 77.27%, Gallblader, Triple Energizer Meridian Muscle was 70% and Stomach, Large Intestine Meridian Muscle was 80%. Additional Aqua-Acupuncture treatment improved to be effective in Bladder, Small Intestine Meridian Muscle(77.78%), in Gallblader, Triple Energizer Meridian Muscle(75%), in Stomach, Large Intestine Meridian Muscle(100%). Conclusions : In this study, Oriental treatment especially Aqua-Acupuncture was effective in whiplash injury patients which caused by traffic accident.

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EMF (electromagnetic field strength)가 스퍼터된 ITO 박막의 초기 성장에 미치는 영향

  • Park, So-Yun;Song, Pung-Geun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.183-183
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    • 2015
  • Indium tin oxide (ITO)는 넓은 밴드갭을 가지는 n-type의 축퇴 반도체로 태양전지, 스마트윈도우, 터치 센서, organic light emitting displays (OLEDs) 등에 널리 적용된다. 최근 touch screen panels (TSPs)의 높은 전기적 특성 및 고해상도 요구에 따라 고품질 ITO 박막개발의 수요도 증가하는 추세이다. 지금까지 ITO 박막의 물성 및 기계적 특성에 관한 많은 연구가 진행되어 왔지만 ITO 초박막 에서의 근본적인 물성 변화에 대한 연구는 미흡한 실정이므로, 이러한 연구는 필수적이라 할 수 있다. ITO 초박막은 광학적 특성은 우수하나, 낮은 결정성으로 인해 전기적 특성이 나쁘다는 단점을 가지며, 이러한 ITO 박막의 결정성은 초기 박막 성장과정에 많은 영향을 받는다. ITO 박막의 초기성장과정은 핵이 생성된 후(nucleation), 각각의 위치에서 성장하게 되고(growth), 합쳐지면서(coalescence) 연속적인 막을 형성 하는데(continuous), 이러한 초기 박막 성장 과정 중에 핵 생성 밀도를 증가시키고 박막이 연속적으로 되는 두께를 감소시킨다면, 더욱 더 고품질의 ITO 초박막을 얻을 수 있을 것이다. 따라서, 본 연구에서는 박막 초기 형성 과정 중 섬들이 합체되는 두께를 최소화시키기 위하여 EMF(electromagnetic field strength) 시스템을 이용하였다. EMF 시스템은 DC 캐소드에 전자석 코일을 장착하여 전자기장을 추가로 부가한 것으로, 이를 이용할 경우 스퍼터 원자가 중성상태로 기판에 도달하는 것이 아니라, 이온화되어 Vp-Vf의 차이로 가속되어 추가적인 에너지를 공급받음으로써 기판표면상에서 확산을 촉진시키므로 박막이 연속적으로 되는 임계 두께를 감소시킬 수 있는 것으로 기대된다. 실험은 실온에서 DC 마그네트론 스퍼터링법을 이용하였으며, 유리기판위에 4, 6, 8, 10, 12, 20 nm의 두께로 ITO 박막을 제작하였다. 스퍼터링 파워는 150 W (3.29 W/cm3), 작업 압력은 0.13 Pa, 기판과 타깃 사이의 거리는 70 mm였다. 각각의 두께에서 EMF 파워 0, 5, 10, 15, 20, 25, 30 W로 인가하여 박막을 제작한 후, EMF 파워에 따른 ITO 박막의 초기 성장 과정중 표면상태를 AFM (atomic force microscope) 이미지를 통하여 관찰하였다. 또한, 두께 약 8 nm에서와 20 nm일 때의 전기적 특성 및 광학적 특성을 관찰하였으며, 두 박막 모두 EMF 파워 15 W를 인가하였을 때 그 특성이 가장 향상되는 것을 확인하였다. 이러한 결과를 통하여 박막은 초기 성장이 중요하므로, 매우 얇은 두께에서 좋은 특성을 가진 박막을 제작하여야 박막의 두께를 증가시켰을 때도 좋은 특성의 막을 얻을 수 있음을 알 수 있었다. 또한, EMF 파워를 증가시킴에 따라 자장강도를 증가시키는 것과 같은 효과 즉, 플라즈마 임피던스가 감소하는 효과를 내어 증착 중 고 에너지 입자 (Ar0, O-)에 의한 박막손상이 감소한 것으로 판단된다. 따라서 적정 EMF 파워 15 W를 인가하였을때 가장 물성이 좋은 ITO 박막을 얻을 수 있었다. 즉, EMF 시스템을 이용하여 저온 공정에서 결함농도가 적은 고품질의 ITO 초박막을 제작할 수 있었다.

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A Study on the Seismic Response of a Non-earthquake Resistant RC Frame Using Inelastic Dynamic Analyses (비선형 동적 해석을 이용한 비내진 상세 RC 골조의 지진거동 특성 분석)

  • Jeong, Seong-Hoon;Lee, Kwang-Ho;Lee, Soo-Kueon
    • Journal of the Korea Concrete Institute
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    • v.22 no.3
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    • pp.381-388
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    • 2010
  • In this study, characteristics of the seismic response of the non-earthquake resistant reinforced concrete (RC) frame were identified. The test building is designed to withstand only gravity loads and not in compliance with modern seismic codes. Smooth bars were utilized for the reinforcement. Members are provided with minimal amount of stirrups to withstand low levels of shear forces and the core concrete is virtually not confined. Columns are slender and more flexible than beams, and beam-column connections were built without stirrups. Through the modeling of an example RC frame, the feasibility of the fiber elementbased 3D nonlinear analysis method was investigated. Since the torsion is governed by the fundamental mode shape of the structure under dynamic loading, pushover analysis cannot predict torsional response accurately. Hence, dynamic response history analysis is a more appropriate analysis method to estimate the response of an asymmetric building. The latter method was shown to be accurate in representing global responses by the comparison of the analytical and experimental results. Analytical models without rigid links provided a good estimation of reduced stiffness and strength of the test structure due to bond-slip, by forming plastic hinges closer to the column ends. However, the absence of a proper model to represent the bond-slip poased the limitations on the current inelastic analysis schemes for the seismic analysis of buildings especially for those with round steel reinforcements. Thus, development of the appropriate bond-slip model is in need to achieve more accurate analysis.

SMITH-MAGENS SYNDROME (SMS) : A CASE REPORT (Smith-Magenis Syndrome (SMS) 환아의 증례 보고)

  • Kim, Eun-Young;Lee, Keung-Ho;Choi, Yeong-Chul
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.3
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    • pp.341-347
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    • 2003
  • Smith-Magenis syndrome (SMS) is a clinically recognizable multiple congenital anomaly and mental retardation syndrome caused by an interstitial deletion of chromosome 17 p11.2. Physical features include short stature, characteristic facial appearance: flattened mid-face, down-turned mouth, prominent and often rosy cheeks; prominent jaw in older children and adults, chronic ear infections, hearing impairment, eye problems, including: strabismus (an eye which turns in or out) and myopia (nearsightedness), hoarse voice, short fingers and toes, heart defects or murmurs, problems related to the urinary system, scoliosis (curvature of the spine), an unusual gait (walking pattern), and decreased sensitivity to pain. Behavioral and developmental characteristics include speech delay and articulation problems, developmental delay, learning disability, mental retardation, hyperactivity, self-injury, including: head banging; hand biting; picking at skin, sores and nails; pulling off finger- and toenails; inserting foreign objects into ears, nose, or other body orifices, explosive outbursts, prolonged tantrums, destructive and aggressive behavior, excitability, arm hugging or hand squeezing when excited. This report is the case of a Korean 3-year-3-month old male with Smith-Magenis syndrome referred from local clinic for the treatment of dental caries. The patient was treated by physical restraint after prophylatic administration of antibiotic(Amoxacillin 50mg/kg).

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The Effect of Residual H2Pressure on Gallium-doped ZnO Films Deposited by Magnetron Sputtering (마그네트론 스퍼터링에 의해 제작한 Gallium-doped ZnO 박막에 있어서 잔류 H2O 분압의 영향)

  • Song, Pung-Keun;Kwon, Young-Jun;Cha, Jae-Min;Lee, Byung-Chul;Ryu, Bong-Ki;Kim, Kwang-Ho
    • Journal of the Korean Ceramic Society
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    • v.39 no.10
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    • pp.928-934
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    • 2002
  • Gallium doped Zinc Oxide(GZO) films were deposited by dc magnetron sputtering using a GZO ceramic target at various conditions such as substrate temperature (RT, 400), residual water pressure ($P_{H_2O}$; 1.61${\times}10^{-4}∼2.2{\times}10^{-3}$ Pa), introduction of $H_2$ gas (8.5%) and different magnetic field strengths(250, 1000G). GZO films deposited without substrate heating showed clear degradation in film crystallinity and electrical properties with increasing $P_{H_2O}$. The resistivity increased from 3.0${\times}10^{-3}$ to 3.1${\times}10^{-2}{\Omega}㎝$ and the grain size of the films decreased from 24 to 3 nm when PH2O was increased from 1.61${\times}10^{-4}$ to 2.2${\times}10^{-3}$ Pa. However, degradation in electrical properties with increasing $P_{H_2O}$ was not observed for the films deposited with introduction of 8.5% $H_2$. When magnetic field strength of the cathode increased from 250G to 1000G, crystallinity and electrical properties of GZO films improved remarkably about all the $P_{H_2O}$. This result could be attributed to the decrease in film damage caused by the decrease in plasma impedance.

Electrical Properties of Sputtered Gallium-doped Zinc Oxide Films Deposited Using Ne, Ar, or Kr Gas (Ne, Ar, Kr 가스를 사용하여 제작한 스퍼터 Gallium 도프 ZnO 박막의 전기적 특성)

  • Song, Pung-Keun;Ryu, Bong-Ki;Kim, Kwang-Ho
    • Journal of the Korean Ceramic Society
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    • v.39 no.10
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    • pp.935-942
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    • 2002
  • Gallium-doped ZnO (GZO) films were deposited on soda-lime glass substrate without heating using Ne, Ar, or Kr gas. Electrical properties of GZO films deposited at various total gas pressures were investigated for the film positions corresponding to the erosion region (region B) and outside the erosion region (region A) of the target. Region B showed high resistivity, which was attributed to the decrease in carrier density and Hall mobility, compared to region A. GZO films deposited using Ne gas showed the degradation in resistivity and crystallinity, whereas, GZO films deposited using Kr gas showed the improvement in resistivity and crystallinity. This degradation in film properties could be attributed to the film damage caused by the bombardment of high-energy particles. Especially, the energies of recoiled neutral atoms ($Ne^0,\;Ar^0,\;Kr^0$) calculated by Monte Carlo simulation corresponded to experimental results.

Effects of Daejo-whan on the Ischemic Damage of Cerebral Neurons in Culture (대조환이 대뇌신경세포의 허혈성 손상에 미치는 영향)

  • Park Se Hong;Lee Kwang Ro;Bai sun jun;Cheong Sang Su;Kang Sei Young;Lee Sang Kwan;Lee Sung Keun;Yoon Ji won;Sung Kang Keyng
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.6
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    • pp.1500-1508
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    • 2003
  • This study was performed to clarify the neurotoxic mechanism of nerve cells damage by brain ischemia. The cytotoxic effect of ischemia was determined by XTT assay, NR assay, superoxide dismutase(SOD) activity, amount of malondialdehyde(MDA), lactate dehydrogenase(LDH) activity, protein synthesis and tumor necrosis factor(TNF)-α activities after cerebral neurons derived from mouse were exposed to ischemia for 1∼30 minutes. In addition, the protective effect of extract of Daejo-whan(DJW) on ischemia-induced neurotoxicity was examined in these cultures. 1. Ischemia decreased cell number and viability by XTT assay or NR assay when cultured cerebral neurons were exposed to 95% N2/5% CO₂ for 1∼20 minutes in these cultures. 2. Ischemia decreased SOD and protein syntheses, but it increased amount of MDA and, LDH and TNF-α activities in these cultures. 3. In the neuroprotective effect of DJW extracts on cerebral neurons damaged by ischemia, DJW extracts increased SOD activity and protein synthesis. While, it decreased amount of MDA and, LDH and TNF-α activities after cerebral neurons preincubated with herb extracts. It suggests that brain ischemia has neurotoxicity on cultured mouse cerebral neurons, and the herb extract such as DJW was very effective in blocking the neurotoxicity induced by ischemia in cultured mouse cerebral neurons.