• Computers and Concrete
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• 제1권2호
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• pp.169-188
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• 2004

A coupled damage-viscoplasticity model is presented for the analysis of localisation and size effects. On one hand, viscosity helps to avoid mesh sensitivity because of the introduction of a length scale in the model and, on the other hand, enables to represent size effects. Size effects were analysed by means of three-point bending tests. Correlation between the fracture energy parameter measured experimentally and the density fracture energy modelling parameter is discussed. It has been shown that the dependence of nominal strength and fracture energy on size is determined by the ligament length in comparison with the width of the fracture process zone.

• Molecules and Cells
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• 제37권7호
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• pp.526-531
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• 2014

Human PARP family consists of 17 members of which PARP-1 is a prominent member and plays a key role in DNA repair pathways. It has an N-terminal DNA-binding domain (DBD) encompassing the nuclear localisation signal (NLS), central automodification domain and C-terminal catalytic domain. PARP-1 accounts for majority of poly-(ADP-ribose) polymer synthesis that upon binding to numerous proteins including PARP itself modulates their activity. Reduced PARP-1 activity in ageing human samples and its deficiency leading to telomere shortening has been reported. Hence for cell survival, maintenance of genomic integrity and longevity presence of intact PARP-1 in the nucleus is paramount. Although localisation of full-length and truncated PARP-1 in PARP-1 proficient cells is well documented, subcellular distribution of PARP-1 fragments in the absence of endogenous PARP-1 is not known. Here we report the differential localisation of PARP-1 Nterminal fragment encompassing NLS in PARP-$1^{+/+}$ and PARP-$1^{-/-}$ mouse embryo fibroblasts by live imaging of cells transiently expressing EGFP tagged fragment. In PARP-$1^{+/+}$ cells the fragment localises to the nuclei presenting a granular pattern. Furthermore, it is densely packaged in the midsections of the nucleus. In contrast, the fragment localises exclusively to the cytoplasm in PARP-$1^{-/-}$ cells. Flourescence intensity analysis further confirmed this observation indicating that the N-terminal fragment requires endogenous PARP-1 for its nuclear transport. Our study illustrates the trafficking role of PARP-1 independently of its enzymatic activity and highlights the possibility that full-length PARP-1 may play a key role in the nuclear transport of its siblings and other molecules.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2004년도 춘계학술대회
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• pp.49-50
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• 2004

• Journal of Electrical Engineering and Technology
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• 제4권2호
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• pp.168-174
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• 2009

An application of wavelet analysis to power system transient generated signals is presented in this paper. With the time-frequency localisation characteristics embedded in wavelets, the time and frequency information of a waveform can be presented as a visualised scheme. This feature is very important for non-stationary signals analysis such as the ones generated from power system disturbances. Unlike the Fourier transform, the wavelet transform approach is more efficient in monitoring fault signals as time varies. For time intervals where the function changes rapidly, this method can zoom in on the area of interest for better visualisation of signal characteristics.

• Smart Structures and Systems
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• 제21권6호
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• pp.751-759
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• 2018

Glass fibre reinforced polymers (GFRP) are widely exploited in many industrial branches. Due to this Structural Health Monitoring systems containing embedded fibre optics sensors are applied. One of the problems that can influence on composite element durability is water contamination that can be introduced into material structure during manufacturing. Such inclusion can be a damage origin significantly decreasing mechanical properties of an element. A non-destructive method that can be applied for inspection of an internal structure of elements is THz spectroscopy. It can be used for identifications of material discontinuities that results in changes of absorption, refractive index or scattering of propagating THz waves. The limitations of THz propagation through water makes this technique a promising solution for detection of a water inclusion. The paper presents an application of THz spectroscopy for detection and localisation of a water drop inclusion embedded in a GFRP material between two fibre optics with fibre Bragg grating sensors. The proposed filtering method allowed to determine a 3D shape of the water drop.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.464-473
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• 2006

This paper summarises theoretical and experimental work on the feedback control of sound radiation from honeycomb panels using piezoceramic actuators. It is motivated by the problem of sound transmission in aircraft, specifically the active control of trim panels. Trim panels are generally honeycomb structures designed to meet the design requirement of low weight and high stiffness. They are resiliently-mounted to the fuselage for the passive reduction of noise transmission. Local coupling of the closely-spaced sensor and actuator was observed experimentally and modelled using a single degree of freedom system. The effect of the local coupling was to roll-off the response between the actuator and sensor at high frequencies, so that a feedback control system can have high gain margins. Unfortunately, only relatively poor global performance is then achieved because of localisation of reduction around the actuator. This localisation prompts the investigation of a multichannel active control system. Globalised reduction was predicted using a model of 12 channel direct velocity feedback control. The multichannel system, however, does not appear to yield a significant improvement in the performance because of decreased gain margin.

• Interaction and multiscale mechanics
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• 제1권1호
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• pp.143-156
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• 2008

Elliptical tubes may buckle in an elastic local buckling failure mode under uniform compression. Previous analyses of the local buckling of these members have assumed that the cross-section is hollow, but it is well-known that the local buckling capacity of thin-walled closed sections may be increased by filling them with a rigid medium such as concrete. In many applications, the medium many not necessarily be rigid, and the infill can be considered to be an elastic material which interacts with the buckling of the elliptical tube that surrounds it. This paper uses an energy-based technique to model the buckling of a thin-walled elliptical tube containing an elastic infill, which elucidates the physics of the buckling phenomenon from an engineering mechanics basis, in deference to a less generic finite element approach to the buckling problem. It makes use of the observation that the local buckling in an elliptical tube is localised with respect to the contour of the ellipse in its cross-section, with the localisation being at the region of lowest curvature. The formulation in the paper is algebraic and it leads to solutions that can be determined by implementing simple numerical solution techniques. A further extension of this formulation to a stiffness approach with multiple degrees of buckling freedom is described, and it is shown that using the simple one degree of freedom representation is sufficiently accurate for determining the elastic local buckling coefficient.

• Smart Structures and Systems
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• 제20권6호
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• pp.669-682
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• 2017

The normalised version of bispectrum, the so-called bicoherence, has often proved a reliable method of damage detection on engineering applications. Indeed, higher-order spectral analysis (HOSA) has the advantage of being able to detect non-linearity in the structural dynamic response while being insensitive to ambient vibrations. Skewness in the response may be easily spotted and related to damage conditions, as the majority of common faults and cracks shows bilinear effects. The present study tries to extend the application of HOSA to damage localisation, resorting to a neural network based classification algorithm. In order to validate the approach, a non-linear finite element model of a 4-meters-long cantilever beam has been built. This model could be seen as a first generic concept of more complex structural systems, such as aircraft wings, wind turbine blades, etc. The main aim of the study is to train a Neural Network (NN) able to classify different damage locations, when fed with bispectra. These are computed using the dynamic response of the FE nonlinear model to random noise excitation.

• 한국전통조경학회지
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• 제30권3호
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• pp.87-96
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• 2012

본 연구는 경남 거창군 가조면에 위치한 모현정과 수포대를 통해 장소애착과 장소착근의 문화현상이 어떠한 방법으로 구현되고 있는지를 실증적으로 확인하고자 하였다. 모현정과 수포대가 입지한 지명 '대학동(大學洞)'에서는 동방오현인 한훤당(寒暄堂) 김굉필(金宏弼)과 일두 정여창(鄭汝昌)의 도학(道學) 강론 터의 의미가 부여되어 있으며, 모현정을 품은 오도산(吾道山 1,134m) 또한 상기 선현이 베푸는 학문의 영향으로 산 이름조차 유교의 도(道)를 지칭한 '오도(吾道) 산(山)'으로 전환된 것에서 성리학적 발상이 깊이 내재되어 있음을 발견하게 된다. "현인을 사모하고 그리워"한다는 '모현(慕賢)'의 정명(亭名)에는 영남사림의 성리학적 조종(祖宗)이자 동방오현인 훤두 양선생(兩先生)과 선조 평촌(坪村) 최숙량(崔淑梁)을 숭모하고 추념하기 위한 장소애착의 정서가 수렴되어 있다. 더불어 오도재와 평촌을 추모하기 위한 기적비(紀蹟碑)와 한훤당을 상징하는 감나무의 식재 그리고 모현정 전면에 솟은 지동암은 실천을 통해 도학의 정신을 드러내고자 한 상기 3인의 일치된 의지를 상징하는 기념비적 표상으로, 후손 및 사림에 의한 장소애착의 반복적 표현이라는 점에 동의하게 된다. 다년간 강학(講學)하며 성리학을 향토 선비들에게 전하고, 자연을 노래한 명소 수포대 반석에 새긴 '훤두양선생장구지소'와 '평촌최공강학지소(坪村崔公講學地所)'라는 각자의 의미에서 집단 기억 속에 재생 전승되어 온 고유한 장소의미를 확인하게 된다. 이와 함께 모현정에 게판된 시문과 중수기 및 상량문의 장소언어 대부분이 모현정과 수포대에 대한 연원과 역사성을 환기시키는 내용으로 채워져 있음에서 '강학과 교유의 장'이자 장수지소(藏修之所)로서 각인된 공간 의미와 선현 숭모의 정신을 엿볼 수 있다. 이러한 장소전승은 장소에 대한 긍정적 감정 결속의 결과이며, 장소 정착과정을 통해 생긴 자연발생적 장소착근의 결과로 이루어진 산물이 모현정과 수포대라 할 수 있다. 이와 같은 결과를 종합할 때, 모현정과 수포대는 선현의 발자취를 추념하고 알리기 위한 장소애착의 공간이며, 모현정과 수포대 바위각자는 이곳에 누적된 장소의미를 함축적으로 보여주는 장소착근의 대표적 사례라 할만하다. 장소애착과 장소착근의 과정을 되짚어보는 것은 전통적 기념 공간 및 추모공원의 원형적 모습을 유추하는데 유효할 뿐만 아니라 현대적 의미의 장소 재현을 위해서도 매우 시사적이라 판단된다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 2호
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• pp.231-236
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• 1999

금번 연구는 공간 음상 정위에 직면하는 주된 문제점인 음색왜곡과 음질저하의 영향 인자들과 개선방안을 고찰한다. 측정 머리전달함수로부터 청각기관의 공간 음상에 대만 인지양적 특성치 (양귀 음압레벨 차이 ILD와 음압 도달시간 차비 ITD)를 추정하는 새로운 방법의 제안, 총간 음상정위 특성치의 새로운 DB구축, 그러고 이를 이용한 공간 음상 정위 구현방법의 새로운 방안을 소개한다. 그리고, 제안된 공간 음상 구현 기법은 음색 왜곡 및 음질저하를 최소화할 뿐 아니라 구현 방법의 간결성 때문에 제품화로 직접 적용할 수 있는 장점을 제공할 수 있음을 본 논문에서 보인다.