• Journal of Environmental Health Sciences
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• v.32 no.3
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• pp.215-221
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• 2006

This study investigated the inactivation of the total coliform, an indicator organism in chlorine dioxide, in order to assess the optimal disinfection procedure for drinking water treatment and distribution systems. This research focus on a number of factors, including the dosage of disinfectant, contact time, pH, temperature and DOC. Water samples were taken from the outlet of a settling basin at a conventional surface water treatment system. As the pH increased in the range of pH 6-9, the bactericidal effects of disinfectants decreased. Changes in levels of pH did not significantly after the disinfection effect of chlorine dioxide for total coliform. With an increase in temperature, there was a subsequent increase in the bactericidal effects of disinfectants. Thus, it is evident that a decrease in temperature will higher the CT values required to inactivate coliform for during the winter. DOC addition can also reduce total coliform inactivation. DOC is the most significant variable in total coliform inactivation with chlorine dioxide.

• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.53-59
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• 2001

The Primary Production of phytoplanktons produces organic matter in high concentration in eutrophicated Hakata Bay, Japan, even during the winter season in spite of low water temperature. Phytoplanktons are considered to have any biological capabilities to keep activities of photosynthesis under the unfavorable conditions, and this affects water quality of the bay. In this study, seasonal variations in primary production efficiency were predicted by using a simple box-type ecosystem model, which introduced the concept of efficiency for absorption of solar radiation energy in relation to growth of phytoplanktons under the low solar radiation intensity. According to the simulation result of primary production, it was organic pollution comes from dissolved organic carbon (DOC) throughout the year, DOC of which is originated from the primary production of phytoplanktons on biological response of the seasonal variation of ambient conditions.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.259-262
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• 2005

This study aims to identify the relationship between characteristics of aqueous organic matter and chlorination by-products formation potential according to temporal effect of Juam reservoir in Sun-Choen. The molecular weight distribution and chemical composition of precursors and their relationship with disinfection by-products(DBPs) were investigated. Most of the organic matters was responsible for the major DBP precursors in the raw water are small compounds with a molecular weight less than IKDa, Aromatic contents determined by SUVA correlated well with DBPs, THMs, and HAAs formation. Especially, THMFP/DOC showed better correlation with SUVA than HAAFP/DOC and DBPFP/DOC with SUVA in Juam reservoir. Therefore, effective removal of small molecules or hydrophobic organic matter prior to disinfection process will significantly reduce the DBP concentration in the finished water.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.179-189
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• 1997

Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now studied actively. In this study, a transient one-dimensional model developed to simulate the thermal and conversion characteristics of adiabatic monolithic converters operating under warm up conditions is presented. This model takes into account the gas solid heat and mass transfer, axial heat conduction, chemical reactions and the related heat release. The model has been used to analyze the transient response of an axisymmetric catalytic converter during a warm-up as a function of catalyst design parameters and operation conditions in order to observe their effects on the lightoff behaviour. The experimental test was carried out 2400 cc light diesel engine with DOC.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.379-384
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• 2006

Eight USA soils were used for this study. The purpose of this study is to illustrate the characteristics of metals in the soil based on the sequential extraction with increasing pH. Extracts were analyzed for metals by ICP-MS and for dissolved organic carbon(DOC). As the pH increasing, the DOC extracted in each increment initially decreased and reached the minimum at pH 3 and then increased substantially at higher pH values. According to the pH increasing, the extraction of Ca, Cu, and Zn were illustrated as L type. It was found that there were strong correlation between the extracted Fe and DOC($r=0.64{\sim}0.97$).

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.571-575
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• 2005

A simple, but effective on-line method for estimating the mycelial cell mass concentration from agitation speed data, a most readily-available process variable, has been developed for DO-stat cultures of Agaricus blazei. The dynamic change of dissolved oxygen concentration (DOC) in the initial transient period and the change in yield were considered in the development of the estimation algorithm or estimator. Parameters in the estimation algorithm were calculated from the agitation speed data at 20% of DOC. The proposed estimator could accurately predict the cell mass concentration regardless of DOC levels in the tested range of $10{\sim}40%$, showing a good extrapolation capability.

• Journal of environmental and Sanitary engineering
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• v.13 no.1
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• pp.166-173
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• 1998

This study was to investigate the effects of preozonation on the waterborne organic removal by the biologically active GAC fluidized bed on a laboratory scale. The raw water to be treated comes from midstream of Han river. As the ozone dose was increased in the range of $1~3{;\}mgO_{3}/mgDOC$, it produced BDOC from 1.82 to 2.65 times. And BDOC formation can be expressed as [BDOC] = 0.74 + 0.21[DOC] ($R^{2}{\;}={\;}0.8399$). The effects of combination of ozonation followed by BACFB (Biological Activated Carbon Fluidized Bed) process were analyzed. At the ozone doze of $1~3{\;}mgO_{3}/mgDOC$, the large fraction of BDOC was removed by BACFB, but parameter revealed only around 10% reduction.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10d
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• pp.184-186
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• 2002

액티브 문서 시스템은 문서를 중심으로 사용자 상호작용이나 통신 등을 지원하는 분산 컴퓨팅 모델로서 내용과 행위 정의를 포함하는 행동 가능한 문서를 통해 분산 응용 시스템을 구현하고자 하는 접근방법이다. 본 논문에서는 이러한 액티브 문서 시스템을 구현하기 위한 coordination 미들웨어로서 XForms를 이용하여 사용자 상호작용과 행위를 정의하고 웹 클라이언트가 HTTP와 소켓 기반 통신을 통해 coordination을 담당하는 시스템의 설계와 구현을 소개한다. 개발된 플랫폼 ThruDoc은 웹 상에서 여러 사용자가 액티브 문서를 통해 동시에 데이터 접근을 가능하게 하며, 동시 접근 단위와 락킹 행동을 XForms 문서에서 유연하게 정의할 수 있어 기존의 액티브 문서지원 미들웨어와 비교하였을 때 웹 기반의 구조에 자연스럽게 통합되면서도 자유로운 행위 정의가 가능하고 문서 공유가 실시간으로 가능하다는 장점을 가진다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.913-915
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• 2005

국제적으로 표준화 된 객체지향 언어 중 하나인 ada는 동시수행제어(concurrent) 프로그래밍 언어로 임베디드 시스템에서 가장 널리 사용되고 있다. 하지만 현재 ada 프로그램의 주석을 처리하거나 프로그램의 명세를 나타내는 툴은 거의 없다. 이에 기존에 존재하는 javadoc과 비슷한 역할을 하는 AdaDoc을 단순칠 주석들만 출력하는 것이 아닌 몇 가지 특정 tag를 지원하게 하고 명세들을 보기 좋게 출력할 수 있는 자동 문서 생성 시스템으로 확장하였다.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.523-530
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• 2010

This study was conducted to analyze and determine formation potentials for chlorination disinfection by-products (DBPs) from 14 synthetic nitrogen compounds with or without $Br^-$. 5 of 14 compounds were 3-aminobenzoic acid, 2-aminophenol, aniline, anthranilic acid and 4-nitroaniline that were relatively shown high for formation of THMs/DOC whether or not $Br^-$ presented. 6 compounds that were p-nitrophenol, 3-aminobenzoic acid, 2-aminophenol, aniline, anthranilic acid and 4-nitroaniline were shown high for formation of haloacetic acids (HAAs)/DOC whether or not $Br^-$ presented. Trichloroacetic acid (TCAA) was dominated in 6 compounds. The formation of haloacetonitriles (HANs)/DOC whether or not $Br^-$ presented was high in 3-aminobenzoic acid, 2-aminophenol, aniline and anthranilic acid. Specially, aniline was detected 14.6∼16.1 ${\mu}g/mg$. The formation of chloral hydrate (CH)/DOC and chloropicrin (CP)/DOC were shown high in 3-aminobenzoic acid and 2-aminophenol in 14 compounds. 6 compounds (3-aminobenzoic acid, 2-aminophenol, aniline, anthranilic acid, 4-nitroaniline, p-nitrophenol) and a commercial humic acid were tested for the formation of DBPs/DOC whether or not $Br^-$ presented. When $Br^-$ was added, the DBPs/DOC was higher for the order of aniline> anthranilic acid> 3-aminobenzoic acid> 4-nitroaniline> humic acid> p-nitrophenol> 2-aminophenol. And when $Br^-$ was not added, the DBPs/DOC was higher for the order of anthranilic acid> aniline> p-nitrophenol> humic acid> 4-nitroaniline> 3-aminobenzoic acid> 2-aminophenol.