• Structural Engineering and Mechanics
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• 제6권2호
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• pp.185-200
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• 1998

Space truss design usually involves two main assumptions: that truss members are pin-ended, and compression members possess brittle post-buckling characteristics. The validity of these assumptions in the design of a new group of space trusses with continuous chords and eccentric joints is questionable. With chord member continuity and the consequent improvement in compression member behaviour, current design practice might be too conservative. In this paper, it is shown that substantial improvements in overall truss strength have resulted when the true member end conditions are considered, thus indicating potential savings in truss weight with considerable magnitudes.

• Coupled systems mechanics
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• 제3권1호
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• pp.27-52
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• 2014

For landfill monitoring and aftercare, long-term prognoses of emission and deformation behaviour are required. Landfills may be considered as heterogeneous porous soil-like structures, in which flow and transport processes of gases and liquids interact with local material degradation and mechanical deformation of the solid skeleton. Therefore, in the framework of continuous porous media mechanics a model is developed that permits the investigation of coupled mechanical, hydraulical and biochemical processes in municipal solid waste landfills.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권3호
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• pp.141-148
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• 2004

We discuss and develop a compact MOSFET modeling scheme in order to obtain accurate descriptions of the drain current and its derivatives up to the 5th order. We have analyzed the physical effects which govern the behaviour of the 3rd derivative in long and deep-subrnicron channel MOSFETs. Our modeling agrees well with experimental data and describes continuous transitions between operating regimes, thanks to the use of continuous functions, which do not introduce any artificial peaks.

• 한국경영과학회지
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• 제28권4호
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• pp.145-153
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• 2003

In this Paper, we examine the limiting distributional behaviour of extreme values of mixed Erlang random variables. We show that, in the finite mixture of Erlang distributions, the component distribution with an asymptotically dominant tail has a critical effect on the asymptotic extreme behavior of the mixture distribution and it converges to the Gumbel extreme-value distribution. Normalizing constants are also established. We apply this result to characterize the asymptotic distribution of maxima of sojourn times in M/M/s queuing system. We also show that Erlang mixtures with continuous mixing may converge to the Gumbel or Type II extreme-value distribution depending on their mixing distributions, considering two special cases of uniform mixing and exponential mixing.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.928-929
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• 2006

Tensile stress-strain and dynamic acoustic resonance tests were performed on Fe-C-Ni-Cu-Mo high-strength steels, characterized by a heterogeneous matrix microstructure and the prevalence of open porosity. All materials display the first yielding phenomenon and, successively, a continuous yielding behavior. This flow behavior can be described by the Ludwigson equation and developes through three stages: the onset of localized plastic deformation at the pore edges; the evolution of plastic deformation at the pore necks (where the austenitic Ni-rich phase is predominant); the spreading of plastic deformation in the interior of the matrix. The analytical modeling of the strain hardening behavior made it possible to obtain the boundaries between the different deformation stages.

• Structural Engineering and Mechanics
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• 제31권4호
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• pp.423-437
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• 2009

In order to perform a step-by-step force-displacement response analysis or dynamic time-history analysis of large buildings with masonry infilled R/C frames, a continuous force-deformation model based on an equivalent strut approach is proposed for masonry infill panels containing openings. The model, which is applicable for degrading elements, can be implemented to replicate a wide range of monotonic force-displacement behaviour, resulting from different design and geometry, by varying the control parameters of the model. The control parameters of the proposed continuous model are determined using experimental data. The experimental program includes fifteen 1/3-scale, single-story, single-bay reinforced concrete frame specimens subjected to lateral cyclic loading. The parameters investigated include the shape, the size, the location of the opening and the infill compressive strength. The actual properties of the infill and henceforth the characteristics needed for the diagonal strut model are based on the assessment of its lateral resistance by the subtraction of the response of the bare frame from the response of the infilled frame.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2006년도 학술발표회 논문집
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• pp.358-365
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• 2006

In this study, fragility curves of continuous buried pipelines subjected to transverse PGD (permanent ground deformation) due to liquefaction are proposed. For the waterworks system, continuos buried pipelines made of ductile iron, poly ethylene, and poly vinyl chloride are analyzed and fragility curves are drawn. Fragility curves are based on the repetitive analyses results and formulated with the dominant factors of behaviour of buried pipeline. With the use of fragility curves, engineers can estimate the status of damage of buried pipeline without overall knowledge of relevant features. Especially, fragility curves proposed in this study will act as a major module of earthquake loss estimation method. Moreover, critical value of magnitude and width of transverse PGD (by which the full damage status of buried pipelines are induced) are estimated. With the use of regression curves of these values, pre evaluation of seismic safety of buried pipelines located within liquefaction hazardous region will be possible.

• Advances in nano research
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• 제15권1호
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• pp.25-34
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• 2023

This paper investigates the dynamics and stability of steady states in a continuous and discrete-time single-mode laser system. By using an explicit criteria we explored the Neimark-Sacker bifurcation of the single mode continuous and discrete-time laser model at its positive equilibrium points. Moreover, we discussed the parametric conditions for the existence of period-doubling bifurcations at their positive steady states for the discrete time system. Both types of bifurcations are verified by the Lyapunov exponents, while the maximum Lyapunov ensures chaotic and complex behaviour. Furthermore, in a three-dimensional discrete-time laser model, we used a hybrid control method to control period-doubling and Neimark-Sacker bifurcation. To validate our theoretical discussion, we provide some numerical simulations.

• 한국전산구조공학회논문집
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• 제14권4호
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• pp.423-434
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• 2001

본 논문은 도로의 선형이 곡선일때, 곡선상에 설치되는 곡선교를 해석함에 있어 에너지법에 기초하여 휨과 순수비틂 효과를 고려한 탄성방정식을 이용한다. 이 탄성방정식은 부정정 구조인 연속곡선박스거더의 정역학적 부정정력을 최소 일의 원리를 적용하여 구한다. 곡선박스거더에 수직단위하중과 단위토크를 작용시켜 전단력, 휨모멘트, 순수비틂모멘트, 그리고 처짐과 회전각에 대한 영향선을 구하며, 실제 하중이 작용할 때 곡선박스거더의 부재력을 구할 수 있도록 하였다.

• Structural Engineering and Mechanics
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• 제11권6호
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• pp.637-650
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• 2001

A structural analysis of cracked R.C. members under instantaneous or sustained loads and imposed displacements is presented. In the first part of the paper the problem of deriving feasible moment-curvature diagrams for a long term analysis of R.C. sections is approached in an exact way by using the Reduced Relaxation Function Method in state I uncracked and the method suggested by CEB in state II cracked. In both states the analysis of the main parameters governing the problem has shown that it is possible to describe the concrete creep behaviour in an approximate way by using the algebraic formulation connected to the Effective Modulus Method. In this way the calculations become quite simple and can be applied in design practice without introducing significant errors. Referring to continuous beams, the structural analysis is then approached in a general way, applying the Force Method and the Principle of Virtual Works. Finally, considering single members, the structural analysis is performed by means of a graphical procedure based on the application of feasible moment-rotation diagrams which allow to easily solve various structural problems and to point out the most interesting aspects of the long term behaviour of cracked R.C. members with rigid or elastically deformable redundant restraints.