• Earthquakes and Structures
• /
• 제1권4호
• /
• pp.371-390
• /
• 2010

Historical buildings in seismically active regions are severely damaged by earthquakes, since they certainly were not designed by the original builders to withstand seismic effects. In particular the reports after major ground motions indicate that earthquake-induced pounding between buildings may lead to substantial damage or even collapse of colliding structures. The research on structural pounding during earthquakes has been recently much advanced, although most of the studies are conducted on simplified single degree of freedom systems. In this paper a detailed pounding-involved response analysis of three adjacent structures is performed, concerning the main bodies of the "Quinto Orazio Flacco" school. The construction includes a main masonry building, with an M-shaped plan, and a reinforced concrete building, separated from the masonry one and realized along its free perimeter. By the analysis of the capacity curves obtained by suitable pushover procedures performed separately for each building, it emerges that masonry and reinforced concrete buildings are vulnerable to earthquake-induced structural pounding in the longitudinal direction. In particular, due to the geometric configuration of the school, a special case of impact between the reinforced concrete structure and two parts of the masonry building occurs. In order to evaluate the pounding-involved response of three adjacent structures, in this paper a numerical procedure is proposed, programmed using MATLAB software. Both a non-linear viscoelastic model to simulate impact and an elastic-perfectly plastic approximation of the storey shear force-drift relation are assumed, differently from many commercial softwares which admit just one non-linearity.

• 한국전산구조공학회논문집
• /
• 제17권2호
• /
• pp.131-140
• /
• 2004

철근콘크리트 구조물의 보수ㆍ보강 등의 유지관리를 위해서는 내구성과 내하성을 동시에 고려한 건전성평가의 의사결정기준이 절실히 요구된다. 본 논문은 CART-ANFIS을 사용하는 철근콘크리트 구조물에 대하여 효율적인 모델을 나타내었다. 철근콘크리트 구조물의 손상과 진단 등에 활용되어온 분류형 전문가시스템의 일종인 퍼지이론을 이용한 결정목 구조와 기존의 인공신경망을 이용한 결정목 구조의 건전성평가를 비교 분석한다. 손상된 철근콘크리트의 내구성 회복을 위한 보강설계 이론과 내하력 증가를 위한 보장설계 이론을 정립시켜 손상검출의 산정식을 유도하였다. 본 연구의 건전성 평가시스템 모델을 이용함으로서 보다 효율적인 철근콘크리트 유지관리 뿐만 아니라 생애주기비용 예측을 수행 할 수 있다.

• 한국문화재보존과학회:학술대회논문집
• /
• 한국문화재보존과학회 2004년도 제20회 발표논문집
• /
• pp.25-32
• /
• 2004

All the works including sculpture created by modern artists contain a message that represents both the ideas and spirit of an era. We are entrusted with the responsibility of transmitting to future generations modern art in as nearly as perfect condition as possible. Thus despite the challenges we face in preserving modern art, we are obliged to conserve it. Especially, outdoor sculpture can be considered as not only works of art themselves, but also a public art. The work of contemporary sculptors often refers to the complexity of social relationships between the art and the public space, so that the public space tends to include the actual public in the art. The conservator at this point needs to preserve tile concept of the public art which is incorporated in the public participation in the sculpture, in addition to the materials of the sculpture itself. Once the sculpture is damaged, it will need restoration. Restoration may be essential to prevent further deterioration, or it may be necessary in order to make an object usable again. It is difficult to generalize about restoration because, as with preventive treatment, the acceptable degree of intervention varies from one discipline to another The degree of treatment including restoration may depend on such variables as available resources, the future use of the object, and the needs of the particular discipline to which it belongs. When conservators start to treat artworks or during the treatment, they will face many moments where they have to make a choice. Codes of ethics are necessary in order to provide a basis for making choices. Even though ethics have always been subject to change depending on an era or culture, the ethics subject will be much easier to reached an agreement on than one involving aesthetic value. The aesthetic value will be one of the most prominent factors for defining the damage: even minor loss of parts or discolouration can be considered as fatal damage for artworks. Sometimes, an alteration of the appearancecould be intended by the artist himself so that the artist's intention could be important factor for judging the damage of artworks. But, modern hermeneutic theories show that the artist's intention cannot be the only factor for consideration, so that the interpretation and application of artist's intent should be an interdisciplinary task regarding distinctive social and cultural backgrounds.

• 대한토목학회논문집
• /
• 제33권2호
• /
• pp.387-395
• /
• 2013

구조물의 건전성을 적절하게 모니터링을 하기 위해서는 정확하고 신뢰할 수 있는 계측데이터가 중요하다. 하지만, 실제로는 환경영향 및 센서고장으로 인해 불완전하고 신뢰할 수 없는 데이터가 계측된다. 센서고장인 경우에는 모니터링을 하기 위한 데이터 자체가 계측이 되지 않는 문제가 발생하고, 온도변화와 같은 환경영향에 의해서는 구조물이 손상되었을 때보다 고유진동수 등의 동특성이 더 큰 폭으로 변화한다. 본 논문에서는 구조건전성 모니터링을 위한 데이터 처리 및 분석의 체계적인 절차를 제시하였으며, 보정된 데이터를 사용하여 통계적으로 산정하는 건전성지수로 Mahalanobis 지수를 적용하였다. 제안된 방법을 트러스구조에서 수치적으로 모사한 데이터를 사용하여 검증하고, 서해대교에서 계측한 현장데이터에 적용하였다.

• Journal of Acupuncture Research
• /
• 제17권2호
• /
• pp.85-93
• /
• 2000

We came to the conclusion after considering all the information from many kinds of books on the circulation courses, cross-link points, functions and the symptoms of disease of Chongmai. The results were as follows : 1. The Chongmai that starts from a Uterus flows to Dazhu through the inside of vertebra after joining Renmai and Duimai at Huiyin. The Chongmais up-line that comes out from Qichong into a surface of body arrives and is scattered at a chest through an abdomen. One strand of them goes upward again and is connected to a throat and lips area. After coming out from Qichong, separated down-line is divided into two parts when it arrives a inner part of a heel through the inner part of a leg. One is for an instep, the other is for the sole of a foot. 2. We call it "Sea of Twelve Meridians" or "Meridian's Sea". Because Chongmai controls all of Meridian by acquired "Basic energy" as getting Stomach's energy, Kidney's energy and air-energy, and there are responsible of physiological phenomenon control. And also we name it "Sea of Blood", because it starts from and provides a nutrition to Uterus. 3. All of these four Meridian such as Renmai, Kidney Meridian, Stomach Meridian and Spleen Meridian are ones that flow around the part of a chest and an abdomen. Chongmai makes energy and blood circulation of a chest and an abdomen be stronger and be controlled. Therefore it makes viscera, bowels and body surface be warm and given a nutrition. So Chongmai becomes "Sea of Viscera and Bowels". 4. Chongmai provides a nutrition for ligament and muscle and makes legs get warm as making energy and blood circulate from head to foot. If Chongmai is energetic, hair is completely easy to grow. 5. To see in pathological phase, Chongmais failure or weakness causes like a chest pain, stomachache, heart attack, a menstrual irregularity and sterility and so on. And also if Chongmai is damaged, it happens that giving a nutrition for lips area is stopped, and then mustache doesn't grow any more.

• Elastomers and Composites
• /
• 제55권2호
• /
• pp.81-87
• /
• 2020

Service life prediction and evaluation of rubber components is the foundational technology necessary for securing the safety and reliability of the product and to ensure an optimum design. Even though the domestic industry has recognized the importance thereof, technology for a systematic design and analysis of the same has not yet been established. In order to develop this technology, identifying the fatigue damage parameters that affect service life is imperative. Most anti-vibration rubber components had been damaged by repeated load and aging. Hence, the evaluation of the fatigue characteristics is indispensable. Therefore, in this paper, we propose a method that can predict the service life of rubber components relatively accurately in a short period of time. This method works even in the initial designing stage. We followed the service life prediction procedure of the proposed rubber components. The weak part of the rubber and the maximum strain were analyzed using finite element analysis of the rubber bushing for the tracked vehicles. In order to predict the service life of the rubber components that were in storage for a certain period of time, the fatigue test was performed on the three-dimensional dumbbell specimen, based on the results obtained by the rubber material acceleration test. The service life formula of the rubber bushing for tracked vehicles was derived using both finite element analysis and the fatigue test. The service life of the rubber bushing for tracked vehicles was estimated to be about 1.7 million cycles at room temperature (initial stage) and about 400,000 cycles when kept in storage for 3 years. Through this paper, the service life for various rubber parts is expected be predicted and evaluated. This will contribute to improving the durability and reliability of rubber components.

• 한국동물학회지
• /
• 제13권1호
• /
• pp.3-8
• /
• 1970

경기도 파주지역의 밤나무숲은 밤나무혹벌(Dryocosmus kuriphilus Yasumatsu)이 1965년 이래로 번성하여 막심한 피해를 받고 있으며 벌목되는 나무의 수가 증가 되어가는 실정이다. 저자는 밤나무혹벌의 생물학적 자연구제의 대책을 연구코저 파주군의 법원리, 마장리, 분수리의 3개처와 양주군의 보광사, 벽제리, 2개처에 대하여 밤나무숲의 곤충상을 조사하였다. 전 지역에 대하여 5목 35종의 곤충을 채집하였으며 법원리에서는 해충의 번성이 심하였으나 분수리에서는 작년가지에 많은 밤나무혹벌의 혹이 금년가지에서는 볼수 없어 하나의 회복증상을 발견하고 그 이유로서 법원리는 숲이 고립되어 있으나 분수리는 상수리나무숲으로 잘 둘러싸여 있다는 사실을 지적, 삼림조성에 있어서의 혼합림조성 방식을 제창하였다.

• 한국환경농학회지
• /
• 제38권2호
• /
• pp.89-95
• /
• 2019

BACKGROUND: Liquid pig manure (LPM) has been used as an alternative for conventional fertilizers on some gramineous crops. However, its chemical properties varied widely depending on the degree of the digestion. A pot experiment was conducted to determine the responses of persimmon trees to immature (not well-digested) LPM application. METHODS AND RESULTS: Ten application levels of immature LPM, consisted of a total of 3 to 30 L in 3-L increment, were applied during summer to 5-year-old 'Fuyu' trees grown in 50-L pots. Increasing the LPM application rate caused defoliation, wilting, and chlorosis in leaves. When applied with the rate of 3 L during summer, the tree produced small fruits with low soluble solids and bore few flower buds the following season, indicating insufficient nutritional status. In trees applied with the LPM rates of 6~12 L, both fruit characteristics and above-ground growth of the trees appeared normal but some roots were injured. However, application of higher LPM rates than 27 L resulted in small size, poor coloration, or flesh softening of the fruits the current season. Furthermore, the high LPM rates caused severe cold injury in shoots during winter and weak shoot growth the following season. It was noted that the application of higher LPM rate than 9 L damaged the root, even though above-ground parts of the tree appeared to grow normally. CONCLUSION: The results indicated that an excessive immature LPM application could cause various injuries on leaves, fruits, and the roots in both the current and the following season.

• 박물관보존과학
• /
• 제26권
• /
• pp.35-66
• /
• 2021

본 연구는 국립중앙박물관 소장 갑주(투구 2점, 갑옷 4점)에 대해 과학적 조사와 보존처리를 실시하고, 그 결과를 바탕으로 조선시대 중·후기 갑주의 구조적인 특징을 살펴본 것이다. 갑주는 유기물과 무기물이 함께 있는 복합 재질이므로, 보존처리는 각 재질의 안정한 조건이 서로 영향을 받지 않는 선에서 '조사·분석 → 오염물 제거 → 안정화 및 강화처리 → 손상 부위 보수 → 보관'의 과정으로 실시하였다. 갑주는 손상이 심한 상태였으나, 보존처리를 통해 안전한 보수 및 일부 부위의 복원을 완료하였다. 이 과정에서 확인된 내용을 바탕으로 조선 중기의 의상형 갑옷 일부(갑상)와 조선 후기의 포형 피갑, 조끼형 흉갑 그리고 투구에 사용된 재료 및 구조적 특징을 파악할 수 있었고, 이를 통해 제작 방법을 추정할 수 있었다.

• 공학기술논문지
• /
• 제5권1호
• /
• pp.11-18
• /
• 2012

Large scale earthquake was occurred in different parts of the world like Japan (in 1995), Republic of Pakistan (2005), in China (2008) etc and enormous structures were damaged. As a result of collapse of school buildings structures numerous students are died and it had a big impact on the international community. Therefore, the interest of preparing the seismic resistant school building structures in our country is increases as school building are used as emergency shelter for local residents. But the current standard of seismic design ratio of 3.7% is applied for school building in Korea which is only significant earthquake damage is expected. In order to overcome the current situation, seismic performance evaluation is carried out for the existing school building and an accurate and appropriate seismic retrofit is required based on performance evaluation to upgrade the existing school buildings. In this paper, nonlinear analysis on existing school buildings for ATC-40(Applied Technology Council, ATC) and FEMA-356(Federal Emergency Management Agency, FEMA) are carried out using the capacity spectrum method to evaluate seismic performance and to determine the need for retrofitting. In addition, after reinforcement to enhance the seismic performance is applied the seismic performance evaluation is carried out to verify the effectiveness of seismic retrofit.