• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.256-257
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• 2019

Recently, the fire risk of architectural structures is increasing due to the super high - rise and super - size of the buildings. Therefore, the direction of fire safety design tends to change from the existing design to the performance - based design. In particular, domestic fire safety policies are divided into building law and fire fighting law. In case of fire fighting law, performance design is already carried out. Therefore, this study summarizes the prediction formula for fire characteristics among the structural fireproofing design field as shown in Fig. 1 according to this situation, and compares it with the standard method of each country in particular.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.171-174
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• 2009

This study analyzes the change of the basic characteristics of pavement concrete according to the reinforcement of macro-fiber and the results of the study can be summarized as follows. In the case of the compressive strength of the concrete, the fiber reinforced pavement concrete shows a small decreasing level compared to the basic mixing of pavement concrete (hereafter referred as 'Plain') based on the aging of 28 days. In particular, the polypropylene fiber made in Korea represents a decrease in the strength about 12% compared with that of the Plain. In the case of the tensile strength, it shows certain improvements in the tensile performance compared with that of the Plain. In particular, in the case of the polyvinyl alcohol fiber that shows the largest improvement in tensile performance, it shows an increase in its strength about 21%. In the case of the bending strength, there are no improvements in its strength in the fiber reinforced concrete compared to that of the Plain.

• Steel and Composite Structures
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• v.17 no.6
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• pp.835-850
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• 2014

The fire resistance of composite steel and concrete structures may be determined by using the simplified methods provided in EN 1994-1-2. For the particular situations not covered by the standard, an advanced calculation model might be applied, using special purpose programs for the analysis of structures in fire. The validation of these programs has always been an important issue for software developers, but also for designers and authorities. Clause 4.4.4 from EN 1994-1-2 refers to the validation of the advanced calculation models and states that these models must be validated through relevant test results. The paper presents the calculation of fire resistance of the composite columns in a high-rise building built in Romania, and focusses on the validation of the calculation model (computer program SAFIR), for this particular case. This validation, asked by the Romanian authorities, considers the available experimental results of a fire test, performed on a similar composite steel-concrete column.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.235-239
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• 1999

This thesis is concerned with the development of useful engineering techniques to detect and analyze nonlinearities in mechanical systems. The methods developed are based on the concepts of higher order spectra, in particular the bispectrum. The study of higher order statistics has been dominated by work on the bispectrum. The bispectrum can be viewed as a decomposition of the third moment(skewness) of a signal over frequency and as such is blind to symmetric nonlinearities. Initially auto higher order spectra are studied in detail with particular attention being paid to normalization method. Traditional method based on the bicoherence are studied. Under certain conditions, notably narrow band signals, the above normalization method is shown to fail and so a new technique based on prewhitening the signal in the time domain is developed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.2 s.257
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• pp.260-268
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• 2007

Demand for the use of 3D CAD DMU systems over the Internet environment has been increased. However, transmission of commercial 3D kernels has delayed the communication effectiveness due to the kernel size. Light weight CAD geometric kernel design methodology is required for rapid transmission in the distributed environment. In this paper, an assembly data structure suitable for the top-down and bottom-up assembly models has been constructed. Part features are stored without a hierarchy so that they are created and saved in no particular order. In particular, this paper proposes a new assembly representation model, called multi-level assembly representation (MAR), for the PDM based assembly DMU system. Since the geometric kernel retains assembly hierarchy and topological information, it is applied to the web-viewer for the PDM based DMU system. Effectiveness of the proposed geometric kernel is confirmed through various case studies.

• Journal of the Korean Magnetics Society
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• v.13 no.4
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• pp.133-154
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• 2003

A comprehensive review is given in this article on magnetic and magnetostrictive properties of nanogranular Co-Fe based alloys, with a particular emphasis on high frequency applications. Structural and physical properties are firstly described, followed by magnetic and magnetostrictive properties. Materials of both thin film and bulk forms are considered. A detailed description on high frequency characteristics of Co-Fe based soft magnetic thin films is then presented.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.735-736
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• 2015

The Physics Outreach Unit at UNSW Australia contributes to the goals of the IAU's Commission 55 by collaborating with established institutions to improve public engagement with science. We aim to not only increase public awareness of astronomy but also ensure the benefits to society of our scientific endeavours are understood. We have found collaborating with like-minded institutions who are working in similar spaces allows both parties to make a larger impact than working alone. For example, our long-term collaboration with the Australian Museum provides the opportunity to engage urban and rural communities with science, audiences to which we do not normally have easy access. To increase our national presence we are exploring new relationships with other institutions, in particular the Astronomical Society of Australia (ASA), in hosting events such as public talks with eminent astronomers, star parties and astronomical workshops. These partnerships help build firm foundations for planning future events, in particular during the International Year of Light 2015.

• Steel and Composite Structures
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• v.1 no.2
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• pp.245-268
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• 2001

The analysis of steel-concrete composite joints presents some particular aspects that increase their complexity when compared to bare steel joints. In particular, the influence of slab reinforcement and column concrete encasement clearly change the moment-rotation response of the joint. Starting from an energy approach developed in the context of steel joints, an extension to composite joints is presented in this paper that is able to provide closed-form analytical solutions. In addition, the possibility of tri-linear or non-linear component behaviour is also incorporated in the model, enabling adequate treatment of the influence of cracked concrete in tension and the softening response of the column web in compression. This methodology is validated through comparison with experimental tests carried out at the University of Coimbra.

• Structural Engineering and Mechanics
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• v.58 no.4
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• pp.641-659
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• 2016

This paper deals with the pure bending of incompressible elastic perfectly plastic two-layer sheets under plane strain conditions at large strains. Each layer is classified by its yield stress, shear modulus of elasticity and its initial percentage thickness in relation to the whole sheet. The solution found is semi-analytic. In particular, a numerical technique is only necessary to solve transcendental equations. The general solution is cumbersome because different analytic expressions for the radial and circumferential stresses should be adopted in different regions of the whole sheet. In particular, there are several alternative ways a plastic region (or plastic regions) can propagate. However, for any given set of material and process parameters the solution to the problem consists of a sequence of rather simple analytic expressions connected by transcendental equations. The general solution is illustrated by a simple example.

• Archives of Pharmacal Research
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• v.22 no.6
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• pp.533-541
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• 1999

Many conventional anticancer drugs display relatively poor selectivity for neoplastic cells, in particular for solid tumors. Furthermore, expression or development of drug resistance, increased glutathione transferases as well as enhanced DNA repair decrease the efficacy of these drugs. Research efforts continue to overcome these problems by understanding these mechanisms and by developing more effective anticancer drugs. Cyclophosphamide is one of the most widely used alkylating anticancer agents. Because of its unique activation mechanism, numerous bioreversible prodrugs of phosphramide mustard, the active species of cyclophosphamide, have been investigated in an attempt to improve the therapeutic index. Solid tumors are particularly resistant to radiation and chemotherapy. There has been considerable interest in designing drugs selective for hypoxic environments prevalent in solid tumors. Much of the work had been centered on nitroheterocyclics that utilize nitroreductase enzyme systems for their activation. In this article, recent developments of anticancer prodrug design are described with a particular emphasis on exploitation of selective metabolic processes for their activation.