• Korean Management Science Review
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• v.15 no.1
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• pp.87-95
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• 1998

The computational speed of interior point method depends on the speed of Cholesky factorization. The supernodal column Cholesky factorization is a fast method that performs Cholesky factorization of sparse matrices with exploiting computer's characteristics. Three steps are necessary to perform the supernodal column Cholesky factorization : symbolic factorization, creation of the elimination tree, ordering by a post-order of the elimination tree and creation of supernodes. We study performing sequences of these three steps and efficient implementation of them.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.333-336
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• 2000

We discuss the direct methods (Gauss-Jordan and Gaussian eliminations) to solve linear systems on distributed memory parallel computers. It will be shown that the so-called row-cyclic storage gives rise to the best performance among the standard three (row-cyclic, column-cyclic and cyclic-cyclic) data storages. We also show that Gauss-Jordan elimination, rather than Gaussian elimination, is highly efficient for the direct solution of linear systems in parallel processing, though Gauss-Jordan elimination requires a larger number of arithmetic operations than Gaussian elimination. Numerical experiment is performed on HITACHI SR12201 with the standard libraries MPI and BLAS.

• Journal of Environmental Science International
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• v.10 no.6
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• pp.401-405
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• 2001

For the purpose of developing a new process f3r the elimination of oil components from oily waste water, experimental researches using oil gelling agent were performed. The process is composed of three units, that is, decantator, gelling column and adsorption column. 10g of gelling agent in the gelling column could effectively absorb 15.65g of oil from ship washing waste water and 16.93g of oil from steel industry waste water. COD in waste waters dramatically diminished not in the gelling column but in the adsorption column. The .gelling is hindered by other organic components in waste water, and the optimum space time f3r the gelling column Is 20min. 1g of gelling agent absorbed 3.7-4.0g of oil from waste waters with 25 min in the batch operation.

• Journal of Ginseng Research
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• v.44 no.6
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• pp.784-789
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• 2020

Background: The separation of isomeric compounds from a mixture is a recurring problem in chemistry and phytochemistry research. The purification of pharmacologically active ginsenoside Rb₃ from ginseng extracts is limited by the co-existence of its isomer Rb₂. The aim of the present study was to develop an enzymatic elimination-combined purification method to obtain pure Rb₃ from a mixture of isomers. Methods: To isolate Rb₃ from the isomeric mixture, a simple enzymatic selective elimination method was used. A ginsenoside-transforming glycoside hydrolase (Bgp2) was employed to selectively hydrolyze Rb₂ into ginsenoside Rd. Ginsenoside Rb₃ was then efficiently separated from the mixture using a traditional chromatographic method. Results: Chromatographic purification of Rb₃ was achieved using this novel enzymatic elimination-combined method, with 58.6-times higher yield and 13.1% less time than those of the traditional chromatographic method, with a lower minimum column length for purification. The novelty of this study was the use of a recombinant glycosidase for the selective elimination of the isomer. The isolated ginsenoside Rb₃ can be used in further pharmaceutical studies. Conclusions: Herein, we demonstrated a novel enzymatic elimination-combined purification method for the chromatographic purification of ginsenoside Rb₃. This method can also be applied to purify other isomeric glycoconjugates in mixtures.

• Advances in concrete construction
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• v.8 no.3
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• pp.165-172
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• 2019

Progressive collapse is one of the factors which if not predicted at the time of structure plan; its occurrence will lead to catastrophic damages. Through having a glance over important structures chronicles in the world, we will notice that the reason of their collapse is a minor damage in structure caused by an accident like a terrorist attack, smashing a vehicle, fire, gas explosion, construction flaws and its expanding. Progressive collapse includes expanding rudimentary rupture from one part to another which leads to total collapse of a structure or a major part it. This study examines the progressive collapse of a 5-story concrete building with three column eliminating scenarios, including the removal of the corner, side and middle columns with the ABAQUS software. Then the beams and the bottom of the concrete slab were reinforced by (reinforcement of carbon fiber reinforced polymer) FRP and then the structure was re-analyzed. The results of the analysis show that the reinforcement of carbon fiber reinforced polymer sheets is one of the effective ways to rehabilitate and reduce the progressive collapse in concrete structures.

• Journal of environmental and Sanitary engineering
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• v.21 no.4 s.62
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• pp.29-38
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• 2006

This study included the development of analytical method for determining perchlorate in water sample. The analytical condition was referred in EPA 314.0 method which use ion chromatography and the concentrator column was replaced by the guard column. Concentrating 10mL raw or treated water sample on to AGl6 guard column made it possible to get the LOD(Limit of Detection) of $0.73\;{\mu}g/L$. The total run time was 11 minutes and during run time next sample could be concentrated on AGl6 guard column. Compared to the Concentration method which needed manual operation, the Direct Injection method could screen the many water samples. The LOD of the Direct Injection method was higher and the sensitivity was lower than that of the Concentration method. The RSDs(Relative Standard Deviations) were lower than 2.5 % for peak height and 0.7 % for retention time in pre-concentration methods. This method Showed good reproducibility and reliability and it was thought the deviations of recovery value could be reduced by considering column capacity and making water sample homogeneous. Matrix Elimination could be done using the pre-concentration method if perchlorate were in complex matrix of sample.

• Journal of Environmental Science International
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• v.11 no.8
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• pp.783-791
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• 2002

A laboratory-scale dual-column biofilter system was used to study the biofiltration of dimethyl disulfide(DMDS). The biofiltration of DMDS was found to depend on the pollutant loadings rather than the inlet concentrations. It was estimated that the pollutant was only inhibitory to the operation of the biofilters at DMDS concentrations greater than 5500 ppmv A residence time of 30 seconds(120 m$^3$/m$^2$/h volumetric loading) was determined as appropriate for efficient operation(>90%). The maximum elimination capacity for both compost mixtures under the current experimental conditions was found to range from 7.5 to 10 g-DMDS/m$^3$/h. A lower DMDS maximum elimination capacity was exhibited under acidified conditions.

• Journal of Biosystems Engineering
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• v.29 no.2
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• pp.151-158
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• 2004

This research was conducted to study the offensive odor adhesion efficiency of filter bed materials using the experimental column that was designed and constructed in this work. The offensive odor adhesion experiment was conducted using mixture of high physical adhesion efficiency material, and the fixity of deodorization microorganism of selected filter bed material was tested using ammonia exclude microorganism A4-2 and sulfur oxidation microorganism S5-5.2 those were cultured at the Agricultural Chemical Department of Chungnam National University, and deodorization efficiency of selected filter bed material mixture was tested. Followings are summary of these tests results. 1) Amount of elimination of the offensive odor gas ammonia and hydrogen sulfide per unit volume were 0.054 and 0.016 $\ell$/㎤ in rice hull, 0.01 and 0.004 $\ell$/㎤ in rice straw, 0.158 and 0.01 $\ell$/㎤ in coconut, 0.014 and 0.02 $\ell$/㎤ in perlite, 0.004 and 0.003 $\ell$/㎤ in high road ball, and 0.112 and 0.015 $\ell$/㎤ chaff of pine, respectively. 2) Amount of elimination of offensive odor gas of ammonia and hydrogen sulfide per unit vloume were 0.079 and 0.016 $\ell$/㎤ in mixture 1, 0.045 and 0.014 $\ell$/㎤ in mixture 2, 0.123 and 0.017 $\ell$/㎤ in mixture 3, 0.055 and 0.016 $\ell$/㎤ in mixture 4, 0.031 and 0.015 $\ell$/㎤ in mixture 5, and 0.111 and 0.020 $\ell$/㎤ in mixture 6, respectively. 3) The offensive odor elimination microoraganism inoculated to the mixture of chaff of pine (70%) and pert (30%) showed the elimination efficiency of 99.06% and 96.61% against the ammonia and hydrongen sulfide, respectively, during 24 hours period.

• Environmental Engineering Research
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• v.11 no.2
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• pp.77-83
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• 2006

The hot spring water of the north Jeonla province such as Wanggung, Jookrim, Seokjung, and Hwasim, has fluoride concentration of 3.9 mg/L, 12.7 mg/L, 1.9 mg/L, and 6.3 mg/L, respectively. These figures fairly exceed the Korean and WHO standard for potable water, which is 1.5 mg/L. Therefore, in this study, research on elimination of fluoride in a hot spring water of Jookrim region, which has the highest level of fluoride concentration level in the north Jeonla province, was carried out. In analysis of Jookrim hot spring water according to the water quality standard for potable water, pH was very high at 9.25 and the concentration of fluoride was 10 times higher than the standard at 18.2 mg/L. Other measurements were within the standard or not detected. After injecting 10g of activated carbon for elimination of fluoride, the fluoride concentration was measured at 13.5 mg/L, and when 70mL or more of alum 10 g/L solution was injected, the concentration was measured at 2.8 mg/L, and injecting 3g of lime was measured at 9 mg/L. Alum showed the best elimination performance among all individual injections. Injection of 25 mL of activated carbon and 100 mL of alum solution together reduced the fluoride concentration down to 1.3 mg/L, which is under the potable standard. Injection of lime 1g and 75 mL of alum 10 g/L solution together reduced fluoride concentration to 4.1 mg/L. From the modifying HRT, by using ion exchange resin column, the pH was stabilized when HRT was Imin and showed range of $6.7{\sim}7.8$. The fluoride concentration reduced gradually as the HRT increased, and satisfied the potable standard when HRT passed 6 min, and after 30 min HRT, the concentration of fluoride was 0.05 mg/L: almost eliminated.

• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.617-618
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• 1998

A simple and reproducible pretreatment method was developed for the determination of dioxins in milk sample. Liquid-liquid extraction (LLE) was used for the initial extraction of the analyte from milk. For the elimination of interferences coextracted from milk, acid treatment followed by multilayer silica gel, and then alumina column clean-up were performed. The clean extract could be obtained without carbon column or high performance liquid chromatographic (HPLC) clean-up procedure. Polychlorinated biphenyles (PCBs) and dioxins were separated on neutral alumina activated at 180 ℃ for 12 hours. The final extract was analyzed by HPLC and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The recovery of dioxins spiked in milk at 75-300 ppt level was 83.3-98.9% and their relative standard deviation was 4.1-14%.