• Journal of Korean Port Research
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• v.9 no.1
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• pp.45-56
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• 1995

Investigation of the physical behavior of dredged material disposal in coastal water includes estimations of water column concentration in the receiving water, exposure time, the initial deposition pattern as well as thickness of material at the dumping fields near the estuary area. Calculation based on vertical setting and horizontal advection of single particles ignore the effects of bulk properties of the disposed material, vertical and horizontal diffusion, and material dilution due to the entrainment of ambient water during descent. This paper focuses on the spatial and temporal changes in the dumping fields for the water column and bottom at a hypothetically confined coastal water, where the ambient time-invariant velocity and density profiles are applied, within the initial time period following the instantaneous release of the dredged material. This model accounts the behavior of material after release divided into three phases: convective descent, dynamic collapse and long-term passive dispersion

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.1
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• pp.101-106
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• 1993

In order to separate the Freon-12 and air mixture$(CF_2Cl_2/Air=0.1/99.9 vol.%)$ by pressure swing adsorption (PSA), the breakthrough curve was experimentally observed in a fixed bed adsorption column. A single adsorber was packed with various adsorbents such as, the activated carbon(S-AC, W-AC) and the molecular sieve(MS-5A, MS-13X). The order of appearance of breakthrough curve is MS-5A > MS-13X > W-AC > S-AC. The activated carbon was found to be more effective adsorbent for separating Freon-12 from the mixture than the molecular sieve was. From the experimental data obtained by the separation of Freon-12 gas out of the air stream in the steady-state PSA process cycle, whose size is the same one of column used for the breakthrough curve observation, it has been confirmed that Freon-rich gas could be obtained from the purge step of PSA and Freon-free air could be obtained from the adsorption step of PSA cycle.

• IE interfaces
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• v.22 no.1
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• pp.38-43
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• 2009

This paper deals with two most important problems, from both practical and theoretical standpoints, arising when building the ships in N different docks. Such docks have become core components of modern ship construction. One problem is to minimize the number of building docks in the shipyard, while the other is to keep the usage rate of resources fed into docks as constant as possible. In this paper the combined problem is formulated as a single-integer programming model. The LP-relaxation of this model is solved by column-generation techniques. Practical applications of this formulation are also discussed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.849-855
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• 1994

Actively growin Excherichia coli(KCTC 1039) cells were treated with paraquat (1, 1'-dimethyl-4, 4'-bipyridili-um dichloride) by cultivating them in the presence of 1.0mM paraquat. The treatment was carried out with or without shaking to understand the effect of oxygen on paraquat action to thebacterial superoxide dismutase (SOd). By the treatment with vigorous shaking , population growth of the organism almostly stopped and specific activities of SOD of the cells drastically decreased. On contrast ot it, the herbicide showed only l limited inhibitory action on bacterial growth and SOD activity by stationary treatment. Proteins prepared from parquat-treated cells divided into two peaks by Sephacryl column chormatogrpahy, while proteins from the intact cells formed a single peak. Cytoplasmic proteins and plasma membrane proteins of intact cells formed separated three peaks by Sephadex G-75 column chormatography. respectively. Among them the second peak disappeared by paraquat treatment , while the third peak became more apparent. Fractions from the first and the third peak showed SOD activity. Paraquat was detected from the same fractions.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.52.3-53
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• 2015

It has been known that there is "dark gas" invisible either in 21-cm HI or 2.6-mm CO emission which are general tracers of atomic and molecular gas, respectively. Many researchers consider that the dark gas is "Dark Molecular Gas (DMG)" composed of CO-free $H_2$ in the intermediate zone between atomic and full-fledged molecular gas and that HCO+ and OH molecules are good tracers of the DMG since they can form in much lower $H_2$ column densities where CO does not. We have carried out HCO+ J=1-0 absorption observations toward nine bright extragalactic radio continuum sources using the KVN 21-m telescopes as single dishes. We detected HCO+ absorption lines toward two sources. We derive HCO+ and $H_2$ column densities or their limits, and discuss the implications of our results.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.203-208
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• 2001

Objectives of this study included design of head and evaluation of the pullout performance of the headed reinforcement that can be used to replace standard hooks in the building exterior beam-column joints. Results of 36 pullout tests are presented. Test variables included reinforcing bar diameters (16-25mm), embedment depth (6-7db), transverse reinforcement, and single-vs.-group pullout behavior. The square head designed had gross area of 4Ab and thickness of db. The headed reinforcement made of Dl6 bars developed pullout strengths close to the bar yield strength, but larger bars developed strengths smaller than the yield strengths. The pullout resistance increased with decreasing spacing of the transverse reinforcement. Use of column ties with 6.0-db spacing improved the pullout performance of the headed bars without causing difficulties in fabricating the specimens. The comparison of the pullout performances between the headed bars and the standard hooks revealed that strengths, stiffnesses, and ductile behaviors are about the same.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.629-632
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• 2003

This paper presents a way to maximize transmission efficiency and reception ability through transmission diversity technology, which can be adapted to wireless multimedia OFDM system. The presented method is a comparative analysis between a case where parameter $\alpha$for time average is 0.3, 1 with consideration of channel presumption with two types of rms delayed proliferation, which is 50nsec, 150nsec, for the performance analysis of STTC(Space-Time Trellis Code) using time-space ciphering method appropriate for MIMO channel, and performance in the case where presumed channel value from long training column section is applied to according frame in a single frame. The result showed that BER brought SNR improvement of 1.0dB in 10-3 when $\alpha$ was 0.3 than using only the long training column, and showed increase of general performance improvement for the sake of time average rather than the case without.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.124-127
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• 2001

We consider the routing and wavelength assignment problem in survivable WDM transport network without wavelength conversion. We assume the single-link failure and a path protection scheme in optical layer. When a physical network and a set of working paths are given, the problem is to select a link-disjoint protection path for each working path and assign a wavelength for each working and protection path. We give an integer programming formulation of the problem and propose an algorithm to solve it based on column generation technique and variable fixing. We devise a branch-and-price algorithm to solve the column generation problem. We test the proposed algorithm on some randomly generated data and test results show that the algorithm gives very good solutions.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.183-188
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• 1997

Antimicrobial activity of various extracts of Xanthium strumarium L. was tested against 25 strains of bacteria, yeast and fungus. The crude ethylacetate extract exhibited strong growth inhibition to the tested strains with the exception of partial Gram-negative bacteria. The property of antimicrobial compound was very stable under heat treatment at $120^{\circ}C$, but it was unstable in acid (pH 3.0) and alkali (pH 10.0) treatment. The antimicrobial compounds were purified by boiling water extraction, ethylacetate extraction, charcoal column chromatography, silica gel column chro- matography and reverse phase HPLC. The purified compound A and B were detected in a single peak (each above 98% purity) through the HPLC analysis. The compound A and B showed a strong growth inhibition against Gram-negative and positive bacteria in the agar diffusion method. When tested by the FDA method using the esterase, compound A mainly inhibited the growth of bacteria and compound B showed the growth inhibition of both bacteria and yeasts.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.553-558
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• 1999

As a process of development of composite beam-column connection system, structural tests have been conducted to verify moment resisting performance of the system. The tests have been proceeded by two steps, the first being welding performance test of the steel connection rod and stiffners, and the second overall moment resisting capacity of the fuly assembled system. Ten welding test specimens and four prototype specimens have been used in the test. Good structural performance of welding test specimens has been observed without any single welding failure, and sufficient moment resisting capacity has been proved from the overall performance test, with the moment magnitude in excess of the calculated plastic moment.