• Resources Recycling
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• v.15 no.2 s.70
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• pp.10-17
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• 2006

The purpose of this study was to evaluate the effects of blast-furnace slag on strength development and durability of latex-modified concrete (LMC) and ordinary portland cement concrete as slag contents. Main experimental variables were performed latex contents (0%, 10%, 15%) and slag contents (0%, 30%). The compressive and flexural strengths, chloride-ion rapid permeability and chemical attacks resistance were measured to analyze the characteristic of the developed LMC and BS-LMC(latex-modified concrete added blast-furnace slag) on hardened concrete. The test results showed that compressive and flexural strength of BS-LMC increased as the slag contents increased from 0% to 30% at the long term of curing. It considers blast furnace slag used when latex content was up to 10%. The permeability resistance of BS-LMC(latex 10%, blast 30%) was extremely good at the curing time 90 days. Also. the effects of added blast furnace slag on OPC and LMC were increased on the permeability and chemical attacks resistance.

• Resources Recycling
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• v.17 no.5
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• pp.11-18
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• 2008

The purpose of this study was to evaluate the effects of blast-furnace slag on chemical attack and carbonation of latex-modified concrete (LMC) and ordinary portland cement concrete as slag contents. Main experimental variables were performed latex contents (0%, 15%) and slag contents (0%, 30%, 50%). The compressive strengths, chemical attacks resistance and carbonation depth were measured to analyze the characteristic of the developed LMC and BS-LMC(latex-modified concrete added blast-furnace slag) on hardened concrete. The test results showed that compressive strength of BS-LMC with blast-furnace slag content 30% was quite similar to it of OPC without slag content. The structural quality deterioration was concerned when blast slag content was up to 50%. However, carbonation restraint of BS-LMC with blast-furnace slag 30% was bigger then that of opc. Also, the effects of added latex on OPC and BS-LMC were increased on the carbonation restraint and chemical attacks resistance.

• Structural Engineering and Mechanics
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• v.32 no.2
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• pp.251-267
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• 2009

Reinforced concrete (RC) structures consist of two different materials: concrete and steel bar. The stress transfer behaviour between the two materials through bond plays an important role in the load-carrying capacity of RC structures, especially when they subject to lateral load such as blast and seismic load. Therefore, bond and slip between concrete and reinforcement bar will affect the response of RC structures under such loads. However, in most numerical analyses of blast-induced structural responses, the perfect bond between concrete and steel bar is often assumed. The main reason is that it is very difficult to model bond slip in the commercial finite element software, especially in hydrodynamic codes. In the present study, a one-dimensional slide line contact model in LS-DYNA for modeling sliding of rebar along a string of concrete nodes is creatively used to model the bond slip between concrete and steel bars in RC structures. In order to model the bond slip accurately, a new approach to define the parameters of the one-dimensional slide line model from common pullout test data is proposed. Reliability and accuracy of the proposed approach and the one-dimensional slide line in modelling the bond slip between concrete and steel bar are demonstrated through comparison of numerical results and experimental data. A case study is then carried out to investigate the bond slip effect on numerical analysis of blast-induced responses of a RC column. Parametric studies are also conducted to investigate the effect of bond shear modulus, maximum elastic slip strain, and damage curve exponential coefficient on blast-induced response of RC columns. Finally, recommendations are given for modelling the bond slip in numerical analysis of blast-induced responses of RC columns.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.34-41
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• 2008

In this paper, we present an asymptotical analysis of channel capacity of Bell labs layered space-time (BLAST) architectures based on a zero-forcing (ZF) criterion in the sense of signal-to-noise ratio (SNR). We begin by introducing a new relationship related to multi-input multi-output (MIMO) channel capacity. We prove that Diagonal Bell Labs Space-Time (DBLAST) attains the lower bound for MIMO channels when interference nulling is carried out based on the ZF-criterion. An exact closed-form expression for the probability density function of the channel capacity is analyzed. Based on the asymptotic behavior of the channel capacity of each layer, closed-form expressions for the asymptotic ergodic capacity are derived for BLAST. Based on the analysis presented in this paper, we gain an insight on the channel capacity behavior for a MIMO channel. Computer simulation results have verified the validity and accuracy of the proposed analysis for a wide range of antenna array sizes.

• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1054-1058
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• 2012

In order to predict biologically significant attributes such as function from protein sequences, searching against large databases for homologous proteins is a common practice. In particular, BLAST and HMMER are widely used in a variety of biological fields. However, sequence-homologous proteins determined by BLAST and proteins having the same domains predicted by HMMER are not always functionally equivalent, even though their sequences are aligning with high similarity. Thus, accurate assignment of functionally equivalent proteins from aligned sequences remains a challenge in bioinformatics. We have developed the FEP-BH algorithm to predict functionally equivalent proteins from protein-protein pairs identified by BLAST and from protein-domain pairs predicted by HMMER. When examined against domain classes of the Pfam-A seed database, FEP-BH showed 71.53% accuracy, whereas BLAST and HMMER were 57.72% and 36.62%, respectively. We expect that the FEP-BH algorithm will be effective in predicting functionally equivalent proteins from BLAST and HMMER outputs and will also suit biologists who want to search out functionally equivalent proteins from among sequence-homologous proteins.

• Structural Engineering and Mechanics
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• v.51 no.5
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• pp.755-771
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• 2014

Environmental changes, especially global climate change, are creating new challenges to the development of the Arctic regions, which have substantial energy resources. And attention to offshore structures has increased with oil and gas development. The structural impact response of an explosion-resistant profiled blast walls normally changes when it operates in low temperatures. The main objectives of this study are to investigate the structural response of blast walls in low temperature and suggest useful guidelines for understanding the characteristics of the structural impact response of blast walls subjected to hydrocarbon explosions in Arctic conditions. The target temperatures were based on the average summer temperature ($-20^{\circ}C$), the average winter temperature ($-40^{\circ}C$) and the coldest temperature recorded (approximately $-68^{\circ}C$) in the Arctic. The nonlinear finite element analysis was performed to design an explosion-resistant profiled blast wall for use in Arctic conditions based on the behaviour of material properties at low temperatures established by performing a tensile test. The conclusions and implications of the findings are discussed.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.4
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• pp.424-434
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• 2016

A few blast experiments are conducted to investigate the behavior of one-way reinforced concrete(RC) slabs under blast loading. Reflected blast characteristics as well as displacements and damage patterns of RC slabs are measured. Numerical models are also established in the software ANSYS AUTODYN to reproduce the experiments on RC slabs. The numerical models are distinguished from each other by different boundary conditions at the edges of RC slabs, which are assumed to reproduce displacements and damage patterns resulted from the experiments. The boundary condition of the experimental tests is estimated from the numerical simulation results. From the numerical simulation results, the boundary condition should be improved in order to measure the accurate maximum displacement in the experimental tests.

• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.91-94
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• 2004

A numerical analysis was made to investigate the intensity diminution of a simple silencer for high pressure blast flow fields. Reynolds-Averaged Wavier-Stokes equations were solved for an axisymmetric computational domain constructed by multi block Chimera grids. A blast flow field without the silencer was also calculated to validate the present numerical method. The evolution of high pressure blast flow fields was observed by depicting calculated contours of pressure and Mach number. It was found that the tested silencer could achieve 76 percent intensity diminution.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.169-172
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• 2005

A numerical analysis was made In investigate the pressure diminution of a silencer with baffles for high pressure blast flow fields. Reynolds-Averaged Navier-Stokes equations were solved for an axisymmetric computational domain constructed by multi block Chimera grids. A blast flow field was calculated for the silencers that are with one and three baffles. The evolution of high pressure blast flow fields was observed by depicting calculated contours of pressure. It was found that the tested silencer could achieve 97.7 percent pressure diminution.

• Structural Engineering and Mechanics
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• v.75 no.5
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• pp.607-620
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• 2020

A numerical study is carried out to assess the dynamic response and damage level of one- and two-way reinforced concrete (RC) panels subjected to explosive loads by using finite element LS-DYNA software. The precision of the numerical models is validated with the previous experimental test. The calibrated models are used to conduct a series of parametric studies to evaluate the effects of panel wall dimensions, concrete strength, and steel reinforcement ratio on the blast-resistant capacity of the panel under various magnitudes of blast load. The results are used to develop pressure-impulse (P-I) diagrams corresponding to the damage levels defined according to UFC-3-340-02 manual. Empirical equations are proposed to easily construct the P-I diagrams of RC panels that can be efficiently used to assess its safety level against blast loads.