• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1639-1645
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• 1991

Because of the important role LD converters play in the production of high quality steel, various dynamic models have been attempted in the past by many researchers not only to understand the complex chemical reactions that take place in the converter process but also to assist the converter operation itself using computers. And yet no single dynamic model was found to be completely satisfactory because of the complexity involved with the process. The process indeed involves dynamic energy and mass balances at high temperatures accompanied by complex chemical reactions and transport phenomena in the molten state. In the present study, a mathematical model describing the dynamic behavior of LD converter process has been developed. The dynamic model describes the time behavior of the temperature and the concentrations of chemical species in the hot metal bath and slag. The analysis was greatly facilitated by dividing the entire process into three zones according to the physical boundaries and reaction mechanisms. These three zones were hot metal (zone 1), slag (zone 2) and emulsion (zone 3) zones. The removal rate of Si, C, Mn and P and the rate of Fe oxidation in the hot metal bath, and the change of composition in the slag were obtained as functions of time, operating conditions and kinetic parameters. The temperature behavior in the metal bath and the slag was also obtained by considering the heat transfer between the mixing and the slag zones and the heat generated from chemical reactions involving oxygen blowing. To identify the unknown parameters in the equations and simulate the dynamic model, Hooke and Jeeves parttern search and Runge-Kutta integration algorithm were used. By testing and fitting the model with the data obtained from the operation of POSCO #2 steelmaking plant, the dynamic model was able to predict the characteristics of the main components in the LD converter. It was possible to predict the optimum CO gas recovery by computer simulation

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.663-666
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• 2005

Gas hydrates are ice-like compounds that form at the low temperature and high pressure conditions common in shallow marine sediments at water depths greater than 300-500 m when concentrations of methane and other hydrocarbon gases exceed saturation. Estimates of the total mass of methane carbon that resides in this reservoir vary widely. While there is general agreement that gas hydrate is a significant component of the global near-surface carbon budget, there is considerable controversy about whether it has the potential to be a major source of fossil fuel in the future and whether periods of global climate change in the past can be attributed to destabilization of this reservoir. Also essentially unknown is the interaction between gas hydrate and the subsurface biosphere. ODP Leg 204 was designed to address these questions by determining the distribution, amount and rate of formation of gas hydrate within an accretionary ridge and adjacent basin and the sources of gas for forming hydrate. Additional objectives included identification of geologic proxies for past gas hydrate occurrence and calibration of remote sensing techniques to quantify the in situ amount of gas hydrate that can be used to improve estimates where no boreholes exist. Leg 204 also provided an opportunity to test several new techniques for sampling, preserving and measuring gas hydrates. During ODP Leg 204, nine sites were drilled and cored on southern Hydrate Ridge, a topographic high in the accretionary complex of the Cascadia subduction zone, located approximately 80km west of Newport, Oregon. Previous studies of southern Hydrate Ridge had documented the presence of seafloor gas vents, outcrops of massive gas hydrate, and a pinnacle' of authigenic carbonate near the summit. Deep-towed sidescan data show an approximately $300\times500m$ area of relatively high acoustic backscatter that indicates the extent of seafloor venting. Elsewhere on southern Hydrate Ridge, the seafloor is covered with low reflectivity sediment, but the presence of a regional bottom-simulating seismic reflection (BSR) suggests that gas hydrate is widespread. The sites that were drilled and cored during ODP Leg 204 can be grouped into three end-member environments basedon the seismic data. Sites 1244 through 1247 characterize the flanks of southern Hydrate Ridge. Sites 1248-1250 characterize the summit in the region of active seafloor venting. Sites 1251 and 1252 characterize the slope basin east of Hydrate Ridge, which is a region of rapid sedimentation, in contrast to the erosional environment of Hydrate Ridge. Site 1252 was located on the flank of a secondary anticline and is the only site where no BSR is observed.

• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.83-90
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• 1992

Sensitivity of anti-Texoplasma antibody (IgG) test by enzyme·linked immunosorbent assay (ELISA) was evaluated in comparison with indirect laten agglutination (ILA) using 2,016 paired human samples of serum and cerebrospinal quid (CSF) . The samples were collected from neurologic patients in Korea with mass lesions in central nervous system(CNS) as revealed by imaging diagnosis(CTIMRI). When the sera were screened for anti-Toxoplasma antibody by ILA, 76 cases (3.8%) were positive (1:32 or higher titers). In the pairs samples of CSF, no positive reactions were observed. When ELISA was performed using PBS extract of Percoll purified tachysoites as antigen, cut-off absorbance was determined as 0.40 for serum and 0.27 for CSF tests. The antibody positive rates by ELISA were 7.0% in serum and 5.6% in CSF Of them, 40 cases(2.0%) showed positive reactions in both serum and CSF, The antibody positive rates were higher in groups older than 40 years, The rates were higher in male(4.7% by ILA, 8.3% by ELISA) than in female(2.2% by ILA, 5.0% by ELISA). The rates in CSF showed no such sex difference. ELISA showed twice higher positive rates when serum was tested, and was sensitive enough to detect specific antibodies in CSF. Etiologic relations between positive antibody tests and CNS lesions remained unknown.

• Biomolecules & Therapeutics
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• v.18 no.3
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• pp.280-285
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• 2010

Glycosaminoglycans (GAGs) and chitosan have been used as matrix materials to support the dermal part of skin equivalent which is used for both pharmacological and toxicological evaluations of drugs potentially used for dermatological diseases. However, their biological roles of GAGs and chitosan in the skin equivalent are still unknown. In the present study, we evaluated whether GAGs and chitosan directly affect keratinocyte stem cells (KSCs) and their transit-amplifying cells (TA cells). Among supporting matrix materials, chitosan significantly increased the number of ${\alpha}6$ $integrin^{high}/CD71^{high}$ human keratinocyte TA cells by 48.5%. In quantitative real-time RT-PCR analysis, chitosan significantly increased CD71 and CD200 gene transcription whereas not ${\alpha}6$ integrin. In addition, the level of the gene transcription of both keratin 1 (K1) and K10 in the chitosan-treated human keratinocytes was significantly lower than those of control, suggesting that chitosan inhibit keratinocyte differentiation. We also found that N-acetyl-D-glucosamine (NAG) and $\beta$-(1-4)-linked D-glucosamine (D-glc), two components of chitosan, have no effect on the expression of CD71, K1, and K10, suggesting that each monomer component of chitosan is not enough to regulate the number of epidermal keratinocyte lineage. Conclusively, chitosan increases keratinocyte TA cell population which may contribute to the cellular mass expansion of the epidermal part of a skin equivalent system.

• Journal of Preventive Medicine and Public Health
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• v.28 no.3 s.51
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• pp.609-622
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• 1995

Until now there are few available epidemiologic data of osteoporosis in Korea, and the severity of osteoporosis-related health problem has not been widely recognized yet. But the numbers of the old people are increasing in Korea, and in 2000, the proportion of people over 65 will be up to about 6.8% of total population. Therefore, osteoporosis, one of the most common metabolic bone disease among the old people, will be one of the most important public health problem. On this background this study was performed to find out risk factors of the development of osteoporosis in Korean women through case-control approach. The subject of this study were selected among the women who visited menopause clinic in one general hospital in Seoul and were checked bone density from Sep. 1988 to Sep. 1993. Those who were diagnosed to have hypertension, diabetes mellitus, thyroid disease, breast disease, or liver disease, which are thought to influnce bone density, were excluded. Also excluded those who are age-unknown. Finally the subjects were 2,139 women aged between 18 and 79. We operatively defined patient group as those whose bone density is below $1.039/cm^2$, 90% of average bone density of women of 4th decade who visited the same hospital. And we defined control group as whose bone dendity is above $1.15g/cm^2$. We randomly selected 201 women from the patient group and 202 from the control. As independent variables we chose age, menarche age, menopause age, menopause type, the number of siblings, the number of pregnancies, body mass index, taking oral pill or not, feeding type, and educational state. Multiple logistic regression analysis was done to see the influence of these variables on the risk of osteoporosis. Results are as follows; 1. menopausal status was statistically significant risk factor to all women irrespective of her age, while obesity and later menopause age were found to be statistically significant protective factors. 2. The more siblings and pregnancies, the greater tile risk of osteoporosis, but these factors were not statistically significant. This result is not consistent with other studies. Further studies are strongly needed.

• Korean Security Journal
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• no.19
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• pp.23-41
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• 2009

The purpose of this study is to investigate about security service history on 1930s in Korea. This study used materials by historical facts for the regulations, books and newspapers in 1930s. In 1930s, security service was unknown details of the historical contents so far. There are four parts conclusion of this study: police department of provisional government, security service agency in the provisional government, security service agents of an independence movement, the general society of Korea. Firstly, Korean regional government in Manchuria, which Kokminbu(國民府) organized the security service agency(警護局) for protect government and public security. Most importantly, the security service agency appearanced an important place which were the independence movement and self-governing administration for Koreans in Manchuria. And the security service agency was required by the security service regulations(警護條例) as law. Secondly, diversity activities of security service in police were exposed the duty as 'car escort service(車輛警護)' for offenders, the 'township office guard' from mobsters, 'woodland protect service(林野警護團)' for fire-raisers. security service as police officer were widely application for protection and safety from danger. Thirdly, Mass society was needed to service for public security in daily events such as 'noted singer meeting', 'funeral procession to the graveyard', 'athletic meeting' as private establishment of security service agency in nowadays. people were wanted the private security service(私警護) from 1930s to present. Fourthly, Overseas security service mentioned in attack of politician, protect from poison and security service about train vessel fleet. In 1930s, security service is comprehensive protection which were not only bodyguard, but also safeguard for hazardous materials.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2000.11a
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• pp.21-22
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• 2000

Expressed sequence tags (EFTs) are the partial segments of cDNA produced from 5 or 3 single-pass sequencing of cDNA clones, error-prone and generated in highly redundant sets. Advancement and expansion of Genomics made biologists to generate huge amount of ESTs from variety of organisms-human, microorganisms as well as plants, and the cumulated number of ESTs is over 5.3 million, As the EST data being accumulate more rapidly, it becomes bigger that the needs of the EST analysis tools for extraction of biological meaning from EST data. Among the several needs of EST analyses, the extraction of protein sequence or functional motifs from ESTs are important for the identification of their function in vivo. To accomplish that purpose the precise and accurate identification of the region where the coding sequences (CDSs) is a crucial problem to solve primarily, and it will be helpful to extract and detect of genuine CD5s and protein motifs from EST collections. Although several public tools are available for EST analysis, there is not any one to accomplish the object. Furthermore, they are not targeted to the plant ESTs but human or microorganism. Thus, to correspond the urgent needs of collaborators deals with plant ESTs and to establish the analysis system to be used as general-purpose public software we constructed the pipelined-EST analysis system by integration of public software components. The software we used are as follows - Phred/Cross-match for the quality control and vector screening, NCBI Blast for the similarity searching, ICATools for the EST clustering, Phrap for EST contig assembly, and BLOCKS/Prosite for protein motif searching. The sample data set used for the construction and verification of this system was 1,386 ESTs from human intrathymic T-cells that verified using UniGene and Nr database of NCBI. The approach for the extraction of CDSs from sample data set was carried out by comparison between sample data and protein sequences/motif database, determining matched protein sequences/motifs that agree with our defined parameters, and extracting the regions that shows similarities. In recent future, in addition to these components, it is supposed to be also integrated into our system and served that the software for the peptide mass spectrometry fingerprint analysis, one of the proteomics fields. This pipelined-EST analysis system will extend our knowledge on the plant ESTs and proteins by identification of unknown-genes.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.722-729
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• 2004

Leptin is an adipocyte-secreted hormone and its plasma levels correlate with total body fat mass, however, it also plays a regulatory role in immunity, inflammation, and hematopoiesis. Chemokine is known as a chemoattractant cytokine in inflammatory reaction, but its role in leptin reaction has not been well studied. In this study, the direct effect of leptin on the expression of chemokine mRNAs and lipopolysaccharide (LPS)-induced chemokine KC mRNA in mouse peritoneal macrophages was investigated. Leptin did not induce the expression of lymphotactin, RANTES, eotaxin, MIP-1$\beta$, MIP-1$\alpha$, MIP-2, MCP-1, IP-10, TCA-3, and KC mRNA in mouse peritoneal macrophages, and had no direct effect on the expression of these LPS-induced chemokine mRNAs except KC mRNA. The synergistic effect of leptin on the expression of LPS-induced KC mRNA occurred late in the time course of response to LPS. The increased expressions of Ob-Rb mRNA and leptin receptor protein were detected during the LPS treatment. Leptin produced a substantial increase in the stability of the LPS-induced KC mRNA, and the synergistic effect of leptin on LPS-induced KC mRNA expression was further augmented by cycloheximide (CHX). Pyrrolidine dithiocarbamate (PDTC) did not block the synergistic effect of leptin on LPS-induced KC mRNA expression in mouse peritoneal macrophages. These data suggest that although leptin has no direct effect on the expression of lymphotactin, RANTES, eotaxin, MIP-1$\beta$, MIP-1$\alpha$, MIP-2, MCP-1, IP-10, TCA-3, and KC mRNA in mouse peritoneal macrophages, the synergistic effect of leptin on the expression of LPS-induced KC mRNA has the possibility that LPS might induce the expression of the Ob-Rb receptor or an unknown gene(s) that sensitizes macrophages to the synergistic function of leptin. Therefore, further studies are necessary to examine leptin as a regulatory factor of chemokine production.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.123-131
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• 2018

The objective of this study was to evaluate the effect of roasting degree of barley on aroma characteristics of boricha (barley tea) using solvent-assisted flavor evaporation-gas chromatography-mass spectrometry and gas chromatography-olfactometry. Fifteen volatile compounds including pyrazine, ethylpyrazine, butyrolactone, and guaiacol were considered important volatile compounds, which are generated by roasting barley, because concentrations of those volatiles were significantly increased (p<0.05) as roasting degree of barley was darker. Guaiacol (smoky), furfuryl alcohol (burnt sugar), and furfural (caramel) were detected as aroma-active compounds of boricha with high intensity. Aroma intensity of aroma-active compounds in boricha increased with increase in roasting degree of barley. However, one unknown compound with burnt smell was detected as off-flavor in dark roasted barley. Therefore, it is implied that medium roasting of barley is desirable during boricha manufacturing. Furthermore, boricha manufactured with steamed barley contained more abundant volatile flavor compounds, which may lead to better aroma quality of boricha.

• The Journal of the Korean Society for Microbiology
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• v.22 no.4
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• pp.473-483
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• 1987

Present study was undertaken to find when is right time for vaccination against Measles, Mumps and Rubella and what is the seropositive conversion rate after those vacinations. For this purpose, sera from 106 infants and children adimitted in Prediatric Department of Won Kwang University Hospital, Iri, Chonbuk, Korea were divided into 3 groups, such as (1) Vaccination group with definite information when it was given, (2) Unknown group whether vaccination was given or not, (3) Not vaccinated group. They were tested of IgG and IgM antibodies against Measles, Mumps and Rubella using Enzyme Immunoassay method and the following results were obtained. 1. Infants below 6 month of age showed to have IgG antibodies which seemed to have been transferred from mother in 87.8%(29/33) for Measles, 78.8%(26/33) for Mumps and 39.4%(13/13) for Rubella. And they showed IgM antibodies which are thought to have been produced by recent infection in 24.2%(8/33) for Measles, 48.5%(16/33) for Mumps and 9.1%(3/33) for Rubella. 2. Positivity of antibody IgG against Rubella was observed remarkably lower than it is against Measles and Mumps being only 39.4%(13/33) in $0{\sim}5$ month, 30.8%(8/26) in $6{\sim}11$ months, 30%(3/10) in $12{\sim}14$ months and 62.9%(22/35) in $18{\sim}36$ months of age. 3. ${\Delta}OD's$ of IgG and IgM antibodies against Measles were observed increasing with age being 0.444, 0.220 in $0{\sim}5$ months, 0.326, 0.134 in $6{\sim}11$ months, 0.581, 0.140 in $12{\sim}14$ months, 0.512, 0.000 in $15{\sim}17$ months and 0.887, 0.278 in $18{\sim}36$ months of age, respectively. 4. ${\Delta}OD's$ of IgG and IgM antibodies against Mumps were observed increasing with age being 0.427, 0.340 in $0{\sim}5$ months, 0.400, 0.249 in $6{\sim}11$ months, 0.694, 0.314 in $12{\sim}14$ months, 0.539, 0.165 in $15{\sim}17$ months and 0.854, 0.350 in $18{\sim}36$ months of age, respectively. 5. Vaccination for Measles, Mumps and Rubella is generally to start at 15 months of age in Korea, by which age their antibodies are found to exsist in more than 80% of tested samples. So, it seems to be very reasonable to start the vaccination schedule at earlier age than it does currently. 6. From the present study, it seems to have been clearly confirmed that Enzyme Immunoassay method is a reliable method with good reproducibility for mass survey of IgG and IgM antibodies against Measles, Mumps and Rubella in infants and children.