• Earthquakes and Structures
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• v.5 no.6
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• pp.753-779
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• 2013

One of the most important issues in progressive collapse mechanism of the buildings is evaluation of the collapse distribution in presence of the earthquake loads. Here, collapse propagation is investigated by tracking down the location and type of the collapsed beam and column elements, from the first element to the entire buildings. 6-story reinforced concrete ordinary moment resisting frame buildings with one directional mass eccentricity of 0%, 5%, 15% and 25% are studied to investigate differences among the progressive collapse mechanism of the regular and irregular buildings. According to the results of the nonlinear time history analyses, there are some patterns to predict progressive collapse scenarios in beam and column elements of the similar regular and irregular buildings. Results also show that collapse distribution patterns are approximately independent of the earthquake records.

• Journal of Korean Association for Spatial Structures
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• v.13 no.3
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• pp.65-72
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• 2013

Long span arch structure is composed of arch as relatively flexible structure and column as relatively rigid structure. In this study, the characteristic of dynamic response is analyzed according to the natural frequency ratio between arch and columns. The result of analysis for arch as relatively vertical vibration mode is dominant, the influence of columns mainly appears at relatively high frequency band according to increase of 1st mode frequency in column. However, the dynamic characteristic of arch structure is expected to vary with not only frequency ratio but interaction between vibration modes of arch and columns.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.115-121
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• 1963

Aliphatic hydrocarbon gases from rubber pyrolysis have been identified by gas chromatography with tetraethyleneglycol dimethylether column. Rubbers used in this work are polyisoprene, SBR, NBR, polybutadiene, buthyl rubber, polychloroprene and polyurethane rubber. The chromatogram is characteristic for each polymer. Author proposes a method of identification of synthetic rubbers by gas chromatograph of pyrolyzed gas. Sample is pyrolyzed at $450^{\circ}C$ under nitrogen or more effectively helium and gaseous portion, which eliminated liquid condensate, is passed to the column. The appearance of exclusively large peak of isoprene, isobutylene and carbon dioxide shows the presence of polyisoprene, polyisobutylene and polyurethane, respectively. Large peak of butadiene will appear in case of polybutadiene, SBR and NBR, but SBR can be identified through the styrene peak in gas chromatogram of liquid pyrolyzate and NBR can be identified by the evolution of hydrogen cyanide during pyrolysis. Polychloroprene is identified by the evolution of hydrogen chloride. This method could be applied to the identification of copolymer or polymer blend.

• Management Science and Financial Engineering
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• v.9 no.1
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• pp.11-27
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• 2003

In this study, we propose a mathematical model based on the graph theory for the wavelength assignment problem arising in the design of SDH (Synchronous Digital Hierarchy) over WDM (Wavelength Division Multiplexing) ring networks. We propose a branch- and -price algorithm to solve the suggested models effectively within reasonable time in realistic SDH over WDM ring networks. By exploiting the structure of ring networks, we developed a polynomial time algorithm for efficient column generation and a branching rule that conserves the structure of column generation. In a computer simulation study, the suggested approach can find the optimal solutions within reasonable time and show better performance than the existing heuristics.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.6
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• pp.363-375
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• 2001

Chromatography has been method of choice for the separation complex biologi-cal mixtures fro analytical purpose, particularly for the last fifty years. Its use has recently been extended to preparative separation where the productivity relative to the amount of resin and sol-vent used is a matter of concern. To overcome the inherent thermodynamic inefficiency of batch chromatography, as exemplified by the partial temporal usage of the resin and dilution of the product with the solvent, chromatography has been continually modified by separation engineers. Column switching and recycling represnet some of the process modifications that have brought high productivity to chromatography. Recently, the simulated moving bed (SMB) method, which claims a high separation efficiency based on counter-current moving bed chromatography. has be-come the mainstay of preparative separation, especially in chiral separation. Accordingly, this pa-per reviews the current status of SMB along with several chromatographic modification, which may be helpful in routine laboratory and industrial chromatographic practices.

• Journal of the Korea Furniture Society
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• v.13 no.2
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• pp.53-62
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• 2002

Due to the industrial development some scholars insist that homo sapiens has become a new race--homo sedens. Since this great degree of behavioral change often cause problems in the spinal column, the appropriate sitting became critical. The nineteenth-century idea of sitting upright position is not considered as a proper sitting any longer. Recent studies by such psychological scientists as A. C. Mandal, Ernest McCormick, and Karl Kroemer show that the spinal column in s-curve with forward bends should be efficiently supported in that manner. Designing a chair sometimes focuses on aesthetic points rather than true ergonomic considerations. Therefore, these result in deleterious effects on human bodies such as lordosis and kyphosis. In fact, it has been overlooked due to the lack of technical and scientific supports. Also, in a mass production, it is hard to meet everyone's need. However, the well adapted ergonomic considerations should meet the needs for wide ranges of people. Indeed, in this study we will examine designing chairs in ergonomic perspectives and suggest additional controversial points and alternatives.

• Elastomers and Composites
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• v.22 no.1
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• pp.11-19
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• 1987

A coil pyrolyzer and processor-controlled gas chromatograph were used for analysis of rubber for compounding ratio of the single and blend rubber vlucanizates. Variables such as sample size, pyrolysis temperature, time allowed for pyrolysis, the column packing material, its length and programmable temperature for gas chromatography were examined to obtain optimum condition for application to NR, BR and SBR blends. By application fixed conditions, three kinds of standard curves were finally obtained from thirty samples of blend vulcanizates which were prepared in the pilot plant, NIRI. It is possible to determine rubber composition and their ratio in NR, BR and SBR products by pyrolysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3851-3857
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• 2014

Shippers' requests of freight trains vary with time, but generating an additional schedule of freight trains is not easy due to many considerations, such as the line capacity, operation rules, and conflicts with existing trains. On the other hand, an additional freight train schedule has been continuously requested and manually processed by domestic train operation companies using empirical method, which is time consuming. This paper proposes a model to determine the additional freight train schedule that assesses the feasibility of the added freight trains, and generates as many additional schedules as possible, while minimizing the delay of the existing schedules. The problem is presented using time-space network, modeled as multi-commodity flow problem, and solved using the column generation method. Three levels of experiment were conducted to show validity of the proposed model in the computation time.

• Journal of the Korean Applied Science and Technology
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• v.9 no.2
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• pp.157-163
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• 1992

A microorganism, isolated from soil and designated Pseudomonas sp13, produced two kinds of rhamnolipid in the medium containing glucose as carbon source. There were both rhamnolipid contain L-rhamnose and ${\beta}$-hydroxydecanoic acid. Coumpound A and B elucted chloroform-methanol mixed solution of silicic acid column chromatography and recrystallized from a mixture of ether and n-hexane. Studies on the structure of these products reveled that compound A is L-rhamnopyranosyl-${\beta}$-hydroxydecanoyl-${\beta}$-hydroxydecanoic acid and compound B is L-rhamnopyranosyl-L-rhamnopyranosyl-${\beta}$-hydroxydecanoyl-${\beta}$-hydroxydecanoic acid.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.381-385
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• 2003

We consider the bandwidth parking problem arising from telecommunication networks The problem is to determine the set of calls to be routed and an assignment or them to the paths in arc capacitated network. The objective is to maximize profit. We formulate the problem as an integer programming and propose an algorithm to solve it. Column generation technique to solve the linear programming relxation is proposed with two types of columns in addition, to obtain an optimum integer solution, we consider a new branching strategy. Computational experiments show that the algorithm gives option at solutions within reasonably small time limits.