• Structural Engineering and Mechanics
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• 제53권2호
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• pp.189-204
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• 2015

After the large destruction of Lisbon due to the 1755 earthquake, the city had to be almost completely rebuilt. In this context, an innovative structural solution was implemented in new buildings, comprising internal timber framed walls which, together with the floors timber elements, constituted a 3-D framing system, known as "cage", providing resistance and deformation capacity for seismic loading. The internal timber framed masonry walls, in elevated floors, are constituted by a timber frame with vertical and horizontal elements, braced with diagonal elements, known as Saint Andrew's crosses, with masonry infill. This paper describes an experimental campaign to assess the in-plane cyclic behaviour of those so called "frontal" walls. A total series of 4 tests were conducted in 4 real size walls. Two models consist of the simple timber frames without masonry infill, and the other two specimens have identical timber frames but present masonry infill. Experimental characterization of the in-plane behaviour was carried out by static cyclic shear testing with controlled displacements. The loading protocol used was the CUREE for ordinary ground motions. The hysteretic behaviour main parameters of such walls subjected to cyclic loading were computed namely the initial stiffness, ductility and energy dissipation capacity.

• 파렛트 뉴스
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• 통권22호
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• pp.13-16
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• 2001

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 1996년도 Language, Information and Computation = Selected Papers from the 11th Pacific Asia Conference on Language, Information and Computation, Seoul
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• pp.21-30
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• 1996

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1199-1202
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• 2008

High mobility bottom gate thin film transistors (TFTs) with an amorphous gallium tin zinc oxide (a-GSZO) channel layer have been produced by rf magnetron cosputtering using a gallium zinc oxide (GZO) and tin (Sn) targets. The effect of the post annealing temperatures ($200^{\circ}C$, $250^{\circ}C$ and $300^{\circ}C$) was evaluated and compared with two series of TFTs produced at room temperature and $150^{\circ}C$ during the channel deposition. From the results it was observed that the effect of pos annealing is crucial for both series of TFTs either for stability as well as for improving the electrical characteristics. The a-GSZO TFTs operate in the enhancement mode (n-type), present a high saturation mobility of $24.6\;cm^2/Vs$, a subthreshold gate swing voltage of 0.38 V/decade, a turn-on voltage of -0.5 V, a threshold voltage of 4.6 V and an $I_{ON}/I_{OFF}$ ratio of $8{\times}10^7$, satisfying all the requirements to be used in active-matrix backplane.

• 한국항해항만학회지
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• 제33권8호
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• pp.539-548
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• 2009

이 논문의 목적은 21세기 BIE엑스포에서 주제와 메시지의 중요성과 역할이 무엇인지 규명하고, 주제와 도시개발에 초점을 두고 있는 2012년 여수엑스포 계획에 유용한 제언을 제공하는 것이다. 1998년 리스본엑스포를 전환점으로, 엑스포의 주제와 메시지는 과학기술의 성과를 강조하는 것보다는 진보에 대한 반성과 지구의 미래를 강조한다. 이러한 변화는 오늘날 인류 사회가 당면한 전지구적 환경문제의 해법 모색과 지속가능한 개발을 보장하는 신기술에 대한 관심을 반영한다. 바다와 연안에 대한 신기술과 신사상을 경연하는 여수엑스포는 비슷한 주제의 리스본엑스포의 사례를 벤치마킹하는 동시에 이와 차별화하기 위한 노력이 필요하다. 이 논문은 여수엑스포의 주제와 도시개발에 대해 다음과 같이 제안하였다. 첫째 해양과 관련된 신기술의 강조와 더불어 그것의 개도국 보급을 위한 여수프로젝트 비전의 강화. 둘째 리스본의 수도재개발과 다른 도시개발전략 즉, 남해안시대와 연계된 해항도시네트워크 구상.

• Asian review of World Histories
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• 제4권1호
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• pp.35-81
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• 2016

The objective of this essay is to propose a cultural history of cosmography and cartography from the thirteenth to the sixteenth centuries. It focuses on some of the processes that characterized these fields of knowledge, using mainly western European sources. First, it elucidates the meaning that the term cosmography held during the period under consideration, and the scientific status that this composite field of knowledge enjoyed, pointing to the main processes that structured cosmography between the thirteenth century and the sixteenth century. I then move on to expound the circulation of cosmographic knowledge among Portugal, Venice and Lisbon in the fourteenth and fifteenth centuries. This analysis will show how cartography and cosmography were produced at the interface of articulated commercial, diplomatic and scholarly networks; finally, the last part of the essay focuses on the specific and quite distinctive use of cosmography in fifteenth-century European culture: the representation of "geo-political" projects on the world through the reformulation of the very concepts of sea and maritime networks. This last topic will be developed through the study of Fra Mauro's mid-fifteenth-century visionary project about changing the world connectivity through the linking of several maritime and fluvial networks in the Indian Ocean, Central Asia, and the Mediterranean Sea basin, involving the circumnavigation of Africa. This unprecedented project was based on a variety of sources accumulated in the Mediterranean Sea basin as well as in Asia and in the Indian Ocean over the course of several centuries.

• Coupled systems mechanics
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• 제1권3호
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• pp.269-283
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• 2012

In the present paper, a multilevel approach for the local nanobuckling analysis of carbon nanotube (CNT) based composite materials is proposed and described. The approach comprises four levels, all of them at nanoscale. The first level aims to propose the potential that describes the interatomic forces between carbon atoms. In the second level, molecular dynamics simulations are performed to extract the elastic properties of the CNT. The third level aims to determine the stiffness of the material that surrounds the CNT (matrix), using the annular membrane analysis. In the fourth level, finite strip analysis of the CNT elastically restrained by the matrix is performed to calculate the critical strain at which the CNT buckles locally. In order to achieve accurate results and take the CNT-matrix interaction into account, the $3^{rd}$ and $4^{th}$ steps may be repeated iteratively until convergence is achieved. The proposed multilevel approach is applied to several CNTs embedded in a cylindrical representative volume element and illustrated in detail. It shows that (i) the interaction between the CNT and the matrix should be taken into account and (ii) the buckling at nanoscale is sensitive to several types of local buckling modes.

• Earthquakes and Structures
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• 제7권1호
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• pp.57-82
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• 2014

The heritage value of the mixed wood-masonry 18th century Pombalino buildings of downtown Lisbon is recognized both nationally and internationally. The present paper focuses on the seismic assessment of global response and retrofitting of a typical Pombalino building by nonlinear static analyses, performed by the research software Tremuri, which is able to model 3D configurations. The structure is modelled using nonlinear beams for masonry panels, while in case of the internal walls (frontal walls) an original formulation has been developed in order to take into account their specific seismic behaviour. Floors are modelled as orthotropic membrane finite elements: this feature allows to simulate the presence of both flexible and rigid diaphragms, being the first ones more representative of the original state while the second ones of retrofitted configurations. Seismic assessment has been evaluated by applying nonlinear static procedure and comparing the performance of different configurations (by considering various retrofitting strategies). Finally, assuming a lognormal cumulative distribution, fragility curves are obtained to be representative of Pombalino buildings: the most important application of such curves is for seismic risk and loss estimation analyses.

• Steel and Composite Structures
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• 제14권6호
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• pp.547-569
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• 2013

In recent years there has been increasing international interest about designing structures that cost less to repair after they have been subjected to strong earthquakes. Considering this interest, an innovative repairable fuse device has been developed for dissipative beam-to-column connections in moment-resisting composite steel and concrete frames. The seismic performance of the device was assessed through an extensive experimental program comprising ten cyclic and two monotonic tests. These tests were conducted on a single beam-to-column specimen with different fuse devices for each test. The devices varied in terms of the chosen geometric and mechanical parameters. The tests showed that the devices were able to concentrate plasticity and to dissipate large amounts of energy through non-linear behavior. Numerical models were developed with Abaqus and simplified design models are also proposed.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2004년도 하계학술연구발표회 논문개요집
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• pp.8-8
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• 2004