• Structural Engineering and Mechanics
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• 제49권4호
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• pp.479-489
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• 2014

In the present study a parametric analysis is conducted to study the effect of pile dimension and soil properties on the nonlinear dynamic response of pile subjected to lateral sinusoidal load at the pile head. The study is conducted on soil-pile model of different pile diameter, pile length and soil modulus, and results are compared to get the effect. The soil-pile system is modelled using Finite element method. The programming is done in MATLAB. Time history analysis of model is done for varying non-dimensional frequency of load and the results are compared to get the non-dimensional frequency at which pile head displacement is maximum in each case. Maximum possible bending moment and soil-pile interacting forces for the dynamic excitation of the pile is also compared. When results are compared with the linear response, it is observed that non-dimensional frequency is reduced in nonlinear response on account of reduction in the soil stiffness due to yielding. Nonlinear response curve shows high amplitude as compared to linear response curve.

• Structural Engineering and Mechanics
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• 제53권2호
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• pp.261-276
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• 2015

Structural damage and moving load identification are the two aspects of structural system identification. However, they universally coexist in the damaged structures subject to unknown moving load. This paper proposed a dynamic response sensitivity-based model updating method to simultaneously identify the structural damage and moving force. The moving force which is equivalent as the nodal force of the structure can be expressed as a series of orthogonal polynomial. Based on the system Markov parameters by the state space method, the dynamic response and the dynamic response derivatives with respect to the force parameters and elemental variations are analytically derived. Afterwards, the damage and force parameters are obtained by minimizing the difference between measured and analytical response in the sensitivity-based updating procedure. A numerical example for a simply supported beam under the moving load is employed to verify the accuracy of the proposed method.

• Earthquakes and Structures
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• 제14권6호
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• pp.493-503
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• 2018

With the further increase of span length, the cable-stayed bridge tends to be more slender, and becomes more susceptible to the seismic action. By taking a super long-span cable-stayed bridge with main span of 1400m as example, structural response of the bridge under the E1 horizontal and vertical seismic excitations is investigated numerically by the multimode seismic response spectrum and time-history analysis respectively, the seismic behavior and also the effect of structural nonlinearity on the seismic response of super long-span cable-stayed bridge are revealed. Furthermore, the effect of structural parameters including the girder depth and width, the tower structural style, the tower height-to-span ratio, the side-tomain span ratio, the auxiliary piers in side spans and the anchorage system of stay cables etc on the seismic performance of super long-span cable-stayed bridge is investigated numerically by the multimode seismic response spectrum analysis, and the favorable earthquake-resistant structural system of super long-span cable-stayed bridge is proposed.

• Coupled systems mechanics
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• 제9권2호
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• pp.183-200
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• 2020

Connection of adjacent buildings with stiff links is an efficient approach for seismic pounding mitigation. However, use of highly rigid links might alter the torsional response in asymmetric plans and although this was mentioned in the literature, no quantitative study has been done before to investigate the condition numerically. In this paper, the effect of rigid coupling on the elastic lateral-torsional response of two adjacent one-story column-type buildings has been studied by comparison to uncoupled structures. Three cases are considered, including two similar asymmetric structures, two adjacent asymmetric structures with different dynamic properties and a symmetric system adjacent to an adjacent asymmetric one. After an acceptable validation against the actual earthquake, the traditional random vibration method has been utilized for dynamic analysis under Ideal white noise input. Results demonstrate that rigid coupling may increase or decrease the rotational response, depending on eccentricities, torsional-to-lateral stiffness ratios and relative uncoupled lateral stiffness of adjacent buildings. Results are also discussed for the case of using identical cross section for all columns supporting eachplan. In contrast to symmetric systems, base shear increase in the stiffer building may be avoided when the buildings lateral stiffness ratio is less than 2. However, the eccentricity increases the rotation of the plans for high rotational stiffness of the buildings.

• Archives of Pharmacal Research
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• 제19권6호
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• pp.462-468
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• 1996

The present study was undertaken to investigate the effects of age on angiotensin II (AII) response and antagonistic activity of losartan using aortic rings and liver homogenates from rats ranging in age from 0.7 to 20 months. Whether the endothelium was present or not, the maximum contractile response to AII decreased with age. Removal of the endothelium enhanced AII-induced maximum contraction and these endothelial effects seemed to be due to endothelium-derived relaxing factor (EDRF) in all ages. Equilibrium binding studies demonstrated an age-related decrease in maximum binding $(B_{max})$ with little change in binding affinity $(K_d)$. In rat aorta, the extent of losartan-induced parallel shifts $(K_B)$ in AII concentration-response curves was not significantly different between ages. In addition, $IC_{50}$ value of losartan in competition binding was not changed with age in rat liver homogenates. These results suggest that the potency of losartan is not altered with age in rat aorta and liver, although AII-induced contractile response and the maximum AII binding decreased significantly with age.

• Earthquakes and Structures
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• 제5권1호
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• pp.67-81
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• 2013

Laterite blocks are used for construction of masonry walls since ages in the South-western coastal areas of India. The south-west coastal areas of India lie in zone III of seismic zonation map of Indian code IS 1893-2002. In spite of the fact that laterite is the most favored masonry material in these regions of India, the structural performance of laterite masonry has not been systematically investigated. Again there are no previous studies addressing, in detail, the seismic performance of laterite masonry buildings. Now that these areas are becoming more and more important from point of view of trade and commerce, there is a need for a detailed research on the seismic response of laterite masonry structures located in these areas. The present paper reports the results of such a study of the seismic response of box-type laterite masonry structures. Time history analysis of these structures under El-Centro acceleration has been performed using commercial finite element software ANSYS. Effect of 'containment reinforcement' on the seismic response of box type laterite masonry structures has been evaluated.

• 한국산학기술학회논문지
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• 제19권12호
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• pp.287-293
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• 2018

한반도는 화산 재해로부터 안전한 지역으로 알려져 왔다. 그러나 최근 백두산 및 일본 화산들을 포함한 극동아시아의 화산 관측동향 및 연구결과들은 더 이상 한반도가 화산 재해로부터 안전한 지역이 아님을 나타내고 있다. 대한민국 정부는 2012년부터 효율적인 화산재해 대응체계 구축을 위해 IT 기반의 화산재해대응시스템(VDRS: Volcanic Disaster Response System)구축기술을 개발해 왔다. VDRS의 주요 사용자는 대한민국 중앙 및 지방정부 공무원들이나 이들 대부분은 화산재해를 경험해 보지 못하였으며, 기본적 지식도 부족하다. 따라서 실제 재난 시, 효과적인 VDRS의 사용 및 재난대응을 위해서는 재해 대응과 관련된 교육 콘텐츠의 개발과 교육의 실시가 매우 중요하다. 본 논문에서는 현실감 있는 화산재해 대응 교육을 위한 가상현실(VR; Virtual Reality) 기반의 모바일 앱 개발을 다루고 있다. 교육의 목적은 화산재해 관련 지식의 전달과 체험이다. 첫째, 공간정보 기반의 VR 콘텐츠를 제작한다. VR 콘텐츠를 제작을 위해서는 수치표고모형 기반 3D 모델이 구축되고, 기상효과 및 다양한 화산재해 확산 가시화 모델이 개발된다. 둘째, 화산재해 대응을 위한 교육앱이 개발된다. 이 단계에서 우리는 12단계의 화산재해 체험 스토리 보드를 제안한다. 앱은 스토리 보드를 기반으로 Unity3D 엔진을 이용하여 개발되며 다양한 화산재해(화산재, 화쇄류, 화산이류 등)를 체험하고 이들에 대한 지식을 전달할 수 있도록 구성된다. 본 연구의 결과는 화산재해 대응 및 예방을 위한 교육에 활용될 수 있을 것이며 향후, 증강현실 기술과 연계한다면 보다 현실감 있는 교육에 활용될 수 있을 것이다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.98-102
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• 2006

Historically, LCD monitors have not been able to be used for frame-sequential stereoscopic 3D visualisation due to their slow pixel response rate. With LCD pixel response rates now in the single-digit millisecond range it is natural to ask whether it is now possible to achieve frame-sequential stereoscopic 3D viewing on LCDs.

• 대한가정학회지
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• 제46권2호
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• pp.51-58
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• 2008

The purpose of this study was to analyze how the appreciation or recognition of quick response systems, with the utilization of technology, can improve operations for businesses in the DongDaeMoon fashion market. A survey was conducted from April 25 to May 10 in 2007, among owners and designers of wholesale shops in the DongDaeMoon fashion market. Data was collected from 270 subjects, and general descriptive and comparative statistical analysis was applied to acquire various parameters. Firstly, the product types within the DongDaeMoon fashion market were small and medium quantity batch production systems. The majority of businesses adopted the production strategy of outsourcing through subcontracted factories. To re-order, a fashion merchandising required 2 to 3 days. Secondly, the design sources of fashion merchandises were national fashion brands, popular items within the same industries, and also fashion magazines. New products was made within 4 days after a sample item was received. Business acquaintances were fashion retail shops of DongDaeMoon, and internet or home shopping companies. Thirdly, the recognition of importance and effects of quick response systems was difference between high and low group of the utilization of technology in the DongDaeMoon fashion market.

• 한국해양공학회지
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• 제37권6호
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• pp.273-281
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• 2023

Recently, offshore structures for eco-friendly energy, such as wind and solar power, have been developed to address the problem of insufficient land space; in the case of energy generation, they are designed on a considerable scale. Therefore, the scalability of offshore structures is crucial. The Korea Research Institute of Ships & Ocean Engineering (KRISO) developed multi-linked floating offshore structures composed of floating bodies and connection beams for floating photovoltaic systems. Large-scale floating photovoltaic systems are mainly designed in a manner that expands through the connection between modules and demonstrates a difference in structural response with connection conditions. A fluid-structure coupled analysis was performed for the multi-linked floating offshore structures. First, the wave load acting on the multi-linked offshore floating structures was calculated through wave load analysis for various wave load conditions. The response amplitude operators (RAOs) for the motions and structural response of the unit structure were calculated by performing finite element analysis. The effects of connection conditions were analyzed through comparative studies of RAOs and the response's maximum magnitude and occurrence location. Hence, comparing the cases of a hinge connection affecting heave and pitch motions and a fixed connection, the maximum bending stress of the structure decreased by approximately 2.5 times, while the mooring tension increased by approximately 20%, confirmed to be the largest change in bending stress and mooring tension compared to fixed connection. Therefore, the change in structural response according to connection condition makes it possible to design a higher structural safety of the structural member through the hinge connection in the construction of a large-scale multi-linked floating offshore structure for large-scale photovoltaic systems in which some unit structures are connected. However, considering the tension of the mooring line increases, a safety evaluation of the mooring line must be performed.