• Steel and Composite Structures
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• v.21 no.5
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• pp.1045-1067
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• 2016

Concrete bridges with corrugated steel webs and prestressed by both internal and external tendons have emerged as one of the promising bridge forms. In view of the different behaviour of components and the large shear deformation of webs with negligible flexural stiffness, the assumption that plane sections remain plane may no longer be valid, and therefore the classical Euler-Bernoulli and Timoshenko beam models may not be applicable. In the design of this type of bridges, both the ultimate load and ductility should be examined, which requires the estimation of full-range behaviour. An analytical sandwich beam model and its corresponding beam finite element model for geometric and material nonlinear analysis are developed for this type of bridges considering the diaphragm effects. Different rotations are assigned to the flanges and corrugated steel webs to describe the displacements. The model accounts for the interaction between the axial and flexural deformations of the beam, and uses the actual stress-strain curves of materials considering their stress path-dependence. With a nonlinear kinematical theory, complete description of the nonlinear interaction between the external tendons and the beam is obtained. The numerical model proposed is verified by experiments.

• Korean Journal of Materials Research
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• v.14 no.7
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• pp.489-493
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• 2004

The electrical property of MMC is essentially important to some applications such as power transmission lines and cables, electronic and electrical components as well as electromagnetic shielding equipments. The behavior of electrical resistivity of $SiC_{w}/Al$ alloy composites under as-extruded and annealed conditions has been investigated within the temperature range from room temperature to $450^{\circ}C$. It can be seen that within entire temperature range, the electrical resistivity of composites was higher than that of an unreinforced matrix alloy under the same condition of either as-extrusion or annealing. The temperature dependence of both exhibited positive incline like a typical metal. The variation of electrical resistivity of an unreinforced matrix alloy with temperature from ambient temperature to $450^{\circ}C$ was nearly monotonous, while those of composites increased monotonously at low temperature and rose to a high level after about $250^{\circ}C or 275^{\circ}C$. The difference of these temperature dependences on electrical resistivity can be interpreted as qualitatively the interfaces of $SiC_{w}$ fibers and matrix, where act as nucleation sites.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.10
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• pp.820-826
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• 2009

The anisotropic phonon conductions with varying Joule heating rate of the silicon film in Silicon-on-Insulator devices are examined using the electron-phonon interaction model. It is found that the phonon heat transfer rate at each boundary of Si-layer has a strong dependence on the heating power rate. And the phonon flow decreases when the temperature gradient has a sharp change within extremely short length scales such as phonon mean free path. Thus the heat generated in the hot spot region is removed primarily by heat conduction through Si-layer at the higher Joule heating level and the phonon nonlocality is mainly attributed to lower group velocity phonons as remarkably dissimilar to the case of electrons in laser heated plasmas. To validate these observations the modified phonon nonlocal model considering complete phonon dispersion relations is introduced as a correct form of the conventional theory. We also reveal that the relation between the phonon heat deposition time from the hot spot region and the relaxation time in Si-layer can be used to estimate the intrinsic thermal resistance in the parallel heat flow direction as Joule heating level varies.

• World Technopolis Review
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• v.1 no.1
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• pp.6-15
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• 2012

Science and technology parks have been popular among policy-makers at several spatial levels to promote innovation and economic growth of certain localities. However, this mainly property-led policy tool has been criticised for two reasons. First, it often failed to successfully support regional networking and technology transfer to regional firms. Only unplanned science and technology parks, such as Silicon Valley, seem to have been successfully fostering regional networking and technology transfer which has led, in turn, to the development of competitive innovative clusters. Secondly, it has too often bet on the same horses and become too specialised in the same fields, such as in micro-electronics or in biotechnology. This specialisation has been theoretically supported by the cluster concept. It has led to both a zero sum game of competition between locations as well as potentially negative path dependence and lock-ins. This paper suggests increasingly supporting diversification in science and technology parks by bringing together hitherto unconnected technologies. Several recently discussed concepts could be used to support diversification, such as related variety (Frenken et al. 2007), regional branching (Boschma and Frenken 2011), regional innovation platforms (Harmaakorpi et al. 2011) and transversality (Cooke 2011).

• Journal of the Korean Society of Combustion
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• v.1 no.1
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• pp.75-82
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• 1996

Laser induced incandescence, LII, recently developed technique for measuring soot concentration in flames, can overcome most of limitations of conventional laser extinction measurement. In this study, experiments were performed to investigate the effect of laser intensity, detection wavelength, and also laser beam quality on both LII signal at a particular position and peak-to-centerline LII signal ratio. The results of LII signal with increasing laser intensity shows its near-independence of laser intensity once threshold level of laser intensity has been reached. However, this near-independence depends on laser beam quality and the incident optical setup. The peak-to-centerline LII signal ratio slowly but continuously increases with laser power. This fact is due to the dependence of LII signal on particle mean diameter. LII signal is attenuated during it passes through the flame containing soot particles. The attenuation rate is inversely proportional to detection wavelength. In this study, LII signal at 680 nm band is 10% greater than the signal at 400 nm band.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.5
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• pp.82-89
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• 1993

In this paper, we proposed the autonomous algorithm of pseudo-exhaustive testing for the multi-level combinational logic circuits. For the processing of shared-circuit that existed in each cone-circuit when it backtracked the path from PO to PI of CUT at the conventional verification testing, the dependent relation of PI-P0 is presented by a dependence matrix so it easily partitioned the sub-circuits for the pseudo-exhaustive testing. The test pattern of sub-circuit's C-inputs is generated using a binary counter and the test pattern of I-inputs is synthesized using a singular cover and consistency operation. Thus, according to the test patterns presented with the recipe cube, the number of test pattrens are reduced and it is possible to test concurrently each other subcircuits. The proposed algorithm treated CUT's net-list to the source file and was batch processed from the sub-circuit partitioning to the test pattern generation. It is shown that the range of reduced ration of generated pseudo-exhaustive test pattern exhibits from 85.4% to 95.8% when the average PI-dependency of ISACS bench mark circuits is 69.4%.

• BMB Reports
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• v.42 no.3
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• pp.142-147
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• 2009

Small-molecule inhibitors of protein kinases have contributed immensely to our understanding of biological signaling path-ways and have been exploited therapeutically for the treatment of cancers and other disease states. The pyridinyl imidazole compounds SB 203580 and SB 202190 were identified as ATP competitive antagonists of the p38 stress-activated protein kinases and have been widely used to elucidate p38-dependent cellular processes. Here, we identify SB 203580 and SB 202190 as potent inhibitors of stress-induced CREB phosphorylation on Serine 111 (Ser-111) in intact cells. Unexpectedly, we found that the inhibitory activity of SB 203580 and SB 202190 on CREB phosphorylation was independent of p38, but instead correlated with inhibition of casein kinase 1 (CK1) in vitro. The inhibition of CK1-mediated CREB phosphorylation by concentrations of pyridinyl imidazoles commonly employed to suppress p38, suggests that in some cases conclusions of p38-dependence derived solely from the use of these inhibitors may be invalid.

• Computers and Concrete
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• v.1 no.2
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• pp.115-130
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• 2004

The flexural ductility of solid rectangular reinforced concrete beams has been studied quite extensively. However, many reinforced concrete beams are neither solid nor rectangular; examples include T-, ${\Gamma}$-, ${\Pi}$- and box-shaped beams. There have been few studies on the flexural ductility of non-rectangular reinforced concrete beams and as a result little is known about the possible effect of sectional shape on flexural ductility. Herein, the effect of sectional shape on the post-peak flexural behaviour of reinforced normal and high-strength concrete beams has been studied using a newly developed analysis method that employs the actual stress-strain curves of the constitutive materials and takes into account the stress-path dependence of the stress-strain curve of the steel reinforcement. It was revealed that the sectional shape could have significant effect on the flexural ductility of a concrete beam and that the flexural ductility of a T-, ${\Gamma}$-, ${\Pi}$- or box-shaped beam is generally lower than that of a solid rectangular beam with the same overall dimensions and the same amount of reinforcement provided. Based on the numerical results obtained, a simple method of ensuring the provision of a certain minimum level of flexural ductility to non-rectangular concrete beams has been developed.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.10
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• pp.922-928
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• 2016

Bearing in mind that global climate change is a rising issue, the coastal community of Prek Thnaot, Cambodia has been put on severe effects about natural disasters caused from poor infrastructure and agriculture dependence. This paper proposes to provide and guide a strategic action for the sustainable development path of coastal community in a more continuous manner including a robust resilience to impacts of climate change, natural disasters, and other risks. In doing so, this paper will help environmentally sound management and coastal resources sustainability being sound for socially and economically inclusive development. Proposed fourteen strategic actions for the research should be accompanying with the participation of and cooperation from the local coastal community. Based on the proposed strategic actions, it is critical that the local authorities and other key stakeholders need to accomplish. Providing a good insight for the central government, the strategic action is expected to integrate and prepare a management strategy plan for the local coastal community level. Therefore, this information can be applied to other coastal areas to promote and ensure sustainable protection and management of coastal resources.

• Korean Journal of Optics and Photonics
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• v.16 no.4
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• pp.319-325
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• 2005

A signal processing method for white light interferometry (WLI), which performs a series of analog signal processing steps to locate the central interference fringe position at high speed: is developed and applied to a WLI temperature sensor system. We found that the new method has random walk of $0.019^{\circ}C/\sqrt{Hz}$ with good linearity. However, the temperature change in the path-matching interferometer results in drift of the measured sensor output. The temperature dependence of drift in the WLI temperature sensor system, was calculated to be $1.42{\mu}m/^{\circ}C$. It is also found that the relationship between the peak spacing in the interferogram and the spacing measured by the method can be nonlinear when the fringe spacing is comparable to the coherence length of the source.