• 제목/요약/키워드: Stand damage

검색결과 94건 처리시간 0.028초

A new SDOF method of one-way reinforced concrete slab under non-uniform blast loading

  • Wang, Wei;Zhang, Duo;Lu, Fangyun;Liu, Ruichao
    • Structural Engineering and Mechanics
    • /
    • 제46권5호
    • /
    • pp.595-613
    • /
    • 2013
  • A new effective model for calculation of the equivalent uniform blast load for non-uniform blast load such as close-in explosion of a one-way square and rectangle reinforced concrete slab is proposed in this paper. The model is then validated using single degree of freedom (SDOF) system with the experiments and blast tests for square slabs and rectangle slabs. Test results showed that the model is accurate in predicting the damage level on the tested RC slabs under the given explosive charge weight and stand-off distance especially for close-in blast load. The results are also compared with those obtained by conventional SDOF analysis and finite element (FE) analysis using solid elements. It is shown that the new model is more accurate than the conventional SDOF analysis and is running faster than the FE analysis.

폭발물 이격거리에 따른 기둥의 손상도와 저항성능 (Damage and Resistance of Columns Based on the Stand-off Distance from Explosives)

  • 노지은;이경구;정란
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2011년도 정기 학술대회
    • /
    • pp.152-155
    • /
    • 2011
  • 최근 폭발 등 극한하중에 대한 관심의 증대와 함께 방폭 및 연쇄붕괴방지를 위한 연구가 활발히 진행되고 있다. 이에, 본 연구에서는 폭발하중하의 강구조물의 손상도와 저항성능을 수치적으로 평가하고자 하였다. 이를 위해 구조물의 폭발피해경감을 위해 가장 중요한 구조부재인 기둥을 대상으로 폭발물과 구조물과의 이격거리를 달리하여 폭발하중을 적용하였다. 유한요소해석을 수행한 결과를 토대로 기둥의 손상도와 잔여압축강도를 비교하고 관계를 도출하였다. 본 연구의 목적은 폭발에 의해 기둥이 손상된 경우 구조물 전체의 연쇄붕괴저항성능에의 손상된 기둥의 기여도를 평가하는 것이다.

  • PDF

Influence of soil-structure interaction on seismic responses of offshore wind turbine considering earthquake incident angle

  • Sharmin, Faria;Hussan, Mosaruf;Kim, Dookie;Cho, Sung Gook
    • Earthquakes and Structures
    • /
    • 제13권1호
    • /
    • pp.39-50
    • /
    • 2017
  • Displacement response and corresponding maximum response energy of structures are key parameters to assess the dynamic effect or even more destructive structural damage of the structures. By employing them, this research has compared the structural responses of jacket supported offshore wind turbine (OWT) subjected to seismic excitations apprehending earthquake incidence, when (a) soil-structure interaction (SSI) has been ignored and (b) SSI has been considered. The effect of earthquakes under arbitrary angle of excitation on the OWT has been investigated by means of the energy based wavelet transformation method. Displacement based fragility analysis is then utilized to convey the probability of exceedance of the OWT at different soil site conditions. The results show that the uncertainty arises due to multi-component seismic excitations along with the diminution trend of shear wave velocity of soil and it tends to reduce the efficiency of the OWT to stand against the ground motions.

Detection of the Damaged Trees by Pine Wilt Disease Using IKONOS Image

  • Lee, S.H.;Cho, H.K.;Kim, J.B.;Jo, M.H.
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
    • /
    • pp.709-711
    • /
    • 2003
  • The purpose of this study is to detect the damaged red pine trees by pine wilt disease using high resolution satellite image of IKONOS Geo. IKONOS images are segmented with eCognition image processing software. A segment based maximum likelihood classification was performed to delineate the pine stand. The pine stands are regarded as a potential damage area. In order to develop a methodology to detect the location of damaged trees from the high resolution satellite image, black and white aerial photographs were used as a simulated image. The developed method based on filtering technique. A local maximum filter was adapted to detect the location of individual tree. This report presents a part of the first year results of an ongoing project.

  • PDF

지리정보(地理情報)시스템(GIS) 이용(利用)과 산림(山林) 병충해(病蟲害) 관리(管理) : 소나무 좀벌레의 모형적(模型的) 예(例) (Geographic Information Systems(GIS) Use in Forest Pest Management : A Simulated Study on Mountain Pine Beetle Infestation)

  • 이규성
    • 한국산림과학회지
    • /
    • 제78권2호
    • /
    • pp.168-176
    • /
    • 1989
  • 컴퓨터 기술을 바탕으로 최근 급속한 발달(發達)을 하고있는 지리정보(地理情報)시스템 (GIS)은 여러 종류의 지구(地區)를 다루어야하는 산림경영(山林經營)에 있어서 커다란 잠재력(潜在力)을 보이고 있다. 이 연구(硏究)에서는 산림 병충해(病蟲害) 관리(管理)의 모형적인 예(例)를 통하여 GIS의 이용(利用) 가능성을 알아보려 한다. 임분(林分)의 특성, 기후(氣候) 상황(狀況)과 지형(地形)등 소나무 좀벌레의 발생(發生)을 좌우하는 인자(因子)들을 공간적(空間的)으로 분석 종합하여 각 지역마다 발생 위험도(危險度)를 지수(指數)로 표시하는 새로운 지도를 만들어 낼수 있었다. 또 다른 공간분석 방법을 통하여 이미 소나무 좀벌레에 감염(感染)된 하나의 임분(林分)으로부터 예상되는 확산(擴散) 경로를 찾아내었다. GIS의 실무적(實務的)인 이용에는 여러가지 고려되어야할 점도 있지만, 공간적인 지구분석(地區分析)을 통하여 산림 경영의 의사결정(意思決定) 과정에 필요한 여러가지 정보를 효과적(效果的)으로 관리(管理) 제공(提供)할 수 있다는 장점을 가지고 있다.

  • PDF

강아지 고리뼈의 치아돌기 골절 진단과 치료 (Diagnosis and treatment of the odontoid process fracture of the axis in a dog)

  • 박형준;이신호;김충희;원청길;조재현
    • 한국동물위생학회지
    • /
    • 제46권1호
    • /
    • pp.87-92
    • /
    • 2023
  • A 7-year-old dog weighing 3.9 kg visited the hospital with symptoms of inability to stand and quadriparesis. There were seizure symptoms 2 months before admission to the hospital, and the symptoms of stiffness and rigidity appeared. Radiographs showed normal vertebrae in cervical vertebral column. Magnetic resonance imaging (MRI) and computed tomography (CT) were performed immediately to diagnose vertebral lameness. As a result of the CT, it was possible to observe the fracture of the odontoid process of the axis, and the exact location of the damage was identified. The odontoid process was fractured and separated from the body of the 2nd cervical vertebra (axis), and fragment of the process was observed inside the vertebral arch of the first cervical vertebra (atlas), and the body of the axis was lifted to the dorsal side. The MRI examination reflected the CT findings and confirmed severe spinal cord compression due to the fracture of the odontoid process. The patient was applied by neck brace and medical management including Mycophenolate mofetil administration was performed. The patient was able to move legs and tail after 2 weeks, and was able to voluntarily defecate, urinate and stand up after 4 weeks of administration.

쓰나미에 대비(對備)한 해안림(海岸林) 조성(造成)과 비구조물(非構造物) 대책(對策) - 일본(日本)의 사례(事例)를 중심(中心)으로 - (Coastal Forest Construction and Non-Structural Measures for Preventing Tsunami Damage - In Case of Japan -)

  • 전근우;김석우;김경남;중도행희;강기차부
    • 한국산림과학회지
    • /
    • 제94권3호통권160호
    • /
    • pp.197-204
    • /
    • 2005
  • 동해에서 발생한 쓰나미가 우리나라에 미치는 영향을 파악하고, 해안림이 쓰나미의 속도와 에너지를 저감시키는 기능 및 비구조물 대책에 대하여 일본의 사례를 중심으로 분석하였다. 자료를 분석한 결과, 1983년과 1993년에 동해에서 발생한 쓰나미는 우리나라 동해안에 1시간 50분만에 도달하였으며, 이로 인해 인명, 재산 및 침수피해가 발생하였다. 또한 쓰나미에 대비하여 해안림을 폭 60m로 조성하면 속도는 30%, 에너지는 10%로 각각 저감되므로 60m 정도의 폭을 확보하도록 하고, 해안림의 임분구조는 혼효림의 복층림으로 하며, 방조시설을 함께 시공하여야 한다. 이와 함께 쓰나미에 대한 대응법과 주의점 등에 대한 적극적인 홍보와 같은 비구조물 대책을 마련하여야 할 것이다.

만성 편마비 뇌졸중 환자의 인지기능이 신체기능 수준 및 기능적 활동에 미치는 영향 (Effects of Cognitive Function on Physical Performance and Functional Activities in Persons with Chronic Hemiparetic Stroke)

  • 나은진;황수진
    • PNF and Movement
    • /
    • 제17권1호
    • /
    • pp.31-39
    • /
    • 2019
  • Purpose: Cognitive function is a main concern for rehabilitation progression in individuals who have sustained brain damage, even among those whose motor function has returned after brain damage. The purpose of this study was to investigate how cognitive impairment relates to functional independence in postural stability and gait performance in patients with chronic hemiparetic stroke. Methods: This was an observational design in an outpatient rehabilitation hospital. Twenty-eight adults with chronic hemiparetic stroke, receiving a course in an outpatient rehabilitation program, participated in this study. They were divided into two groups (i.e., non-cognitive impairment and cognitive impairment groups) via a cut-off score of 23 or less on a mini-mental state examination. Functional independence was assessed with the timed up-and-go test (TUG), 10-meter walk test (10mWT), five times sit-to-stand test (FTSST), Berg balance scale (BBS), and modified Barthel index (MBI). The independent t-test was used for statistical analysis when comparing the two groups. Results: The cognitive impairment group had less functional independence, balance, and gait performance than those of the non-cognitive impairment group had. The former also showed a statistically significant decrease in their TUG score, FTSST score, BBS score, and MBI score compared to the latter, but not in their 10mWT score (p<0.05). Although the non-cognitive impairment group walked faster than the cognitive impairment group did, that difference was not statistically significant (p>0.05). Conclusion: The results of this study suggest that cognitive impairment relates to functional independence in postural stability and the activities of daily living. In rehabilitation settings, cognitive impairment would be considered a major component in therapeutic rehabilitation to overcome the patients difficult physical problems and to treat for improving functional independence more after stroke.

해면버섯균(菌) 꽃송이버섯균(菌)에 의(依)한 낙엽송 생입목(生立木)의 심재부후피해(心材腐朽被害) (Decay Damage of Japanese Larch(Larix leptolepis) Caused by Two Butt-Rot Fungi, Phaeolus schweinitzii and Sparassis crispa)

  • 김현중;김준섭;이창근
    • 한국산림과학회지
    • /
    • 제79권2호
    • /
    • pp.138-143
    • /
    • 1990
  • 낙엽송 성숙임분(成熟林分)(1925년(年) 식재(植栽))내(內)에서 해면버섯균(菌)과 꽃송이버섯균(菌)의 자실체(子實體)가 발생(發生)된 부후피해목(腐朽被害木)을 벌채(伐採)하여 심재부후피해(心材腐朽被害)을 조사(調査)하였다. 벌근단면상(伐根斷面上)에 수(髓)를 중심(中心)하여 나타난 부후단면적율(腐朽斷面積率)은 19.2~74.4%, 부후(腐朽)높이는 수고(樹高) 1.2~5.5m, 부후재적율(腐朽材積率)은 2.2~13.4%였고, 심재부(心材部)에 부후(腐朽)가 나타나는 높이까지를 손실재(損失材)로 보면 전체재적(全體材積)의 27.2%(13.1~37.1%)가 부후(腐朽)된 것으로 나타났다. 양균종간(兩菌種間)의 피해(被害)크기 비교(比較)에서는 꽃송이버섯균(菌)에 의(依)한 피해(被害)가 해연버섯균(菌)에 의(依)한 피해(被害)보다 더 심(甚)하였다. 또한 부후재부(腐朽材部)의 압축강도(壓縮强度)($52{\sim}77kg/cm^2$)와 비중(比重)(0.40~0.47)은 건전목(健全木)의 건전재(健全材)에 비(比)하여 각각(各各) 최고(最高) 77% 및 39%가 감소(減少)한 것으로 나타났고, 부후재부(腐朽材部)가 있는 높이까지의 육안건전재부(肉眼健全材部)의 강도(强度)와 비중(比重)도 최고(最高) 42% 및 26%가 감소(減少)한 것으로 나타났다. 한편 부후피해목(腐朽被害木)과 건전목(健全木)의 연년(連年) 생장량(生長量) 비교(比較)에서, 흉고직경(胸高直徑) 생장량(生長量)은 식재(植栽) 8-14년후(年後)부터 재적(材積) 생장량(生長量)은 식재(植材) 12-21년후(年後)부터 건전목(健全木)에 뒤떨어지는 것으로 나타났다.

  • PDF