• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.5-6
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• 2002

The new spectrometer for X-ray Induced Electron Emission Spectroscopy (XIEES) .has been recently developed in KRISS in collaboration with PTI (Russia). The spectrometer allows to perform research using the XAFS, SXAFS, XANES techniques (D.C.Koningsberger and R.Prins, 1988) as well as the number of techniques from XIEES field(L.A.Bakaleinikov et all, 1992). The experiments may be carried out with registration of transmitted through the sample x-rays (to investigate bulk samples) or/and total electron yield (TEY) from the sample surface that gives the high (down to several atomic mono-layers in soft x-ray region) near surface sensitivity. The combination of these methods together give the possibility to obtain a quantitative information on elemental composition, chemical state, atomic structure for powder samples and solids, including non-crystalline materials (the long range order is not required). The optical design of spectrometer is made according to Johannesson true focusing schematics and presented on the Fig.1. Five stepping motors are used to maintain the focusing condition during the photon energy scan (crystal angle, crystal position along rail, sample goniometer rail angle, sample goniometer position along rail and sample goniometer angle relatively of rail). All movements can be done independently and simultaneously that speeds up the setting of photon energy and allows the using of crystals with different Rowland radil. At present six curved crystals with different d-values and one flat synthetic multilayer are installed on revolver-type monochromator. This arrangement allows the wide range of x-rays from 100 eV up to 25 keV to be obtained. Another 4 stepping motors set exit slit width, sample angle, channeltron position and x-ray detector position. The differential pumping allows to unite vacuum chambers of spectrometer and x-ray generator avoiding the absorption of soft x-rays on Be foil of a window and in atmosphere. Another feature of vacuum system is separation of walls of vacuum chamber (which are deformed by the atmospheric pressure) from optical elements of spectrometer. This warrantees that the optical elements are precisely positioned. The detecting system of the spectrometer consists of two proportional counters, one scintillating detector and one channeltron detector. First proportional counter can be used as I/sub 0/-detector in transmission mode or by measuring the fluorescence from exit slit edge. The last installation can be used to measure the reference data (that is necessary in XANES measurements), in this case the reference sample is installed on slit knife edge. The second proportional counter measures the intensity of x-rays transmitted through the sample. The scintillating detector is used in the same way but on the air for the hard x-rays and for alignment purposes. Total electron yield from the sample is measured by channeltron. The spectrometer is fully controlled by special software that gives the high flexibility and reliability in carrying out of the experiments. Fig.2 and fig.3 present the typical XAFS spectra measured with spectrometer.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.120-124
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• 2007

Fusarium proliferatum KGL0401 was previously isolated from Physalis alkekengi var. francheti plant roots and exhibited higher GA productivity than wild type Gibberella fujikuroi. The :tim of this work was to find out an optimal culture condition for GA production. Various carbon(fructose, glucose, lactose, maltose, sucrose) and nitrogen($KNO_3$, urea, glycine, $NaNO_3,\;NH_4Cl$) sources were used for this study. GAs activities were analysed by gas chromatography and mass spectrometry(GC-MS). The highest yield of $GA_3$ was found in the growth medium supplemented with sucrose as carbon source and $NH_4Cl$ as nitrogen source. The optimum carbon-nitrogen concentration for $GA_3$ production was found to be 0.5 M:0.17 M. Supernatant was prepared from the culture fluid of F. proliferatum KGL0401 cultured for 7 days at 3 0'E and the 10 ul supernatant was treated with 2 leaf-rice seedling.

• Journal of Life Science
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• v.19 no.8
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• pp.1159-1163
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• 2009

It has been postulated that endoplasmic (ER) stress is involved in the development of several diseases. However, the detailed molecular mechanisms have not been fully understood. Therefore, we characterized a genetic network of genes induced by ER stress using cDNA microarray and gene set expression coherence analysis (GSECA), and identified gene function as well as several transcription regulators associated with ER stress. We analyzed time-dependent gene expression profiles in thapsigargin-treated Sk-Hep1 using an oligonucleotide expression chip, and then selected functional gene sets with significantly high expression coherence which was processed into functional clusters according to the expression similarities. The functions related to sugar binding, lysosome, ribosomal protein, ER lumen, and ER to golgi transport increased, whereas the functions with mRNA processing, DNA replication, DNA repair, cell cycle, electron transport chain and helicase activity decreased. Furthermore, functional clusters were investigated for the enrichment of regulatory motifs using GSECA, and several transcriptional regulators associated with regulation of ER-induced gene expression were found.

• Restorative Dentistry and Endodontics
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• v.26 no.4
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• pp.307-315
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• 2001

The application of Nd:YAG laser and irrigants to the root surface can change its surface configurations. The purpose of this study was to investigate the effects of Nd:YAG laser and irrigants on the apical seal of obturated canals. In this study, 66 single rooted teeth were randomly assigned to 4 group of 14 teeth each. 8 teeth were served us positive and negative controls. The teeth were divided into 6 groups as follows. Group A: Nd:YAG laser, 5% NaOCl + Rc-prep Group B: Nd:YAG laser, Saline Group C: 5% NaOCl + Rc-prep Group D: Saline Group E: Positive control Group F: Negative control 66 teeth were instrumented using Maillefer ProFile$^{\circledR}$ (Orifice Shapers, .04 taper, .06 taper Dentsply, Switzerland). Two of each group were selected at random, and the canal wall surfaces were examined under a SEM. 12 teeth of each group were obturated using by lateral condensation technique. Specimens were immersed in india ink for 7days, decalcified by 10% nitric acid, dehydrated by 75. 80. 85, 90, 95 and 100% alcohol in order cleared by methyl salicylate and then measured of dye penetration with stereomicroscope($\times$15 magnification) and Image Pro plus. The data were analyzed statistically by one-way ANOVA test and Duncan's Multiple Range test. The results were as follows : 1. The mean leakage was 0.128$\pm$0.376 for group A, 0.237$\pm$0.325 for group B, 0.397$\pm$0.468 for group C, 0.586$\pm$0.402 for group D, and there were statistically significant differences between group A and group D, group B and group D. (p<0.05). 2. Group A had better sealing ability than Group C, but there was statistically no significant differences. (p>0.05). 3. Group B had better sealing ability than Group D and there was statistically significant difference. (p<0.05). 4 Group A had better sealing ability than Group B, but there was statistically no significant difference. (p>0.05). 5. Group C had better sealing ability than Group D, but there was statistically no significant difference. (p>0.05). 6. As a result of observation under SEM, Smear layers were removed in Group A, B. but Smear layers were partially removed and smear plugs were remained in Group C, Smear layers were not removed in Group D. To be specially, Melting of smear layer were showed in Group C. 7. These results suggests that the laser has a potential in reducing the apical microleakage of obturated canals.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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• pp.83-89
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• 2006

Cellular functions are carried out by a concerted action of biochemical pathways whose components have genetic interactions. Abnormalities in the activity of the genes that constitute or modulate these pathways frequently have oncogenic implications. Therefore, identifying the upstream regulatory genes for major biochemical pathways and defining their roles in carcinogenesis can have important consequences in establishing an effective target-oriented antitumor strategy We have analyzed the gene expression profiles of human liver cancer samples using cDNA microarray chips enriched in liver and/or stomach-expressed cDNA elements, and identified groups of genes that can tell tumors from non-tumors or normal liver, or classify tumors according to clinical parameters such as tumor grade, age, and inflammation grade. We also set up a high-throughput cell-based assay system (cell chip) that can monitor the activity of major biochemical pathways through a reporter assay. Then, we applied the cell chip platform for the analysis of the HCC-associated genes discovered from transcriptome profiling, and found a number of cancer marker genes having a potential of modulating the activity of cancer-related biochemical pathways such as E2F, TCF, p53, Stat, Smad, AP-1, c-Myc, HIF and NF-kB. Some of these marker genes were previously blown to modulate these pathways, while most of the others not. Upon a fast-track phenotype analysis, a subset of the genes showed increased colony forming abilities in soft agar and altered cell morphology or adherence characteristics in the presence of purified matrix proteins. We are currently analyzing these selected marker genes in more detail for their effects on various biological Processes and for Possible clinical roles in liver cancer development.

• Korean Journal of Microbiology
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• v.21 no.4
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• pp.221-228
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• 1983

An improved procedure for the rapid purification of glucose-6-phosphate dehydrogenase from extracts of Saccharomyces cerevisiae was developed by using affinity chromatography. Among six affinty media tested, $NADP^+ -agarose$ and Affi-gel Blue were more effective than others (i.e., Affi-gel Red, AMP-agarose, ATP-agarose, and $NAD^+ -agarose$). Conditions to desorb the enzyme bound to the affinity media were examined to increase the purity as well as yield. The best result was obtained when the column was developed with a linear gradient of KCl (0-1.0M). In case of Affi-gel Blue, introduction of $NAD^+$ (15mM) washing step prior to the salt gradient was most effective to remove $NAD^+ -binding$ proteins. For a large scale preparation of G-6-P dehydrogenase higher recovery was obtained by Affi-gel Blue than $NADP^+ -agarose$, however, the purity of the enzyme was decreased by 10 times if the former was used as the affinity medium. The capacity of Affi-gel Blue for G-6-P dehydrogenase was found to be 5 times higher than that of $NADP^+ -agarose$. Furthermore Affi-gel Blue could be reused repeatedly and its preparation is relatively easier and less expensive than $NADP^+ -agarose$.

• Journal of the Korean Geographical Society
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• v.51 no.2
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• pp.255-268
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• 2016

At present, Ganghwa County and Ongjin County of Incheon Metropolitan City are under the application of a different land use regulation like military regulations, etc. due to distinct characteristics of a border area; moreover, these two Counties have degenerated into the deepening area of economic backwardness and decline with the overlapping application of various land use regulations on the ground that these areas belong to a metropolitan area in view of an administrative district. In addition, different support is also implemented for border areas, such as 'the Special Act on Border Area Support' for the border areas, and development projects for special situation areas, etc.; however, realities are that the border areas are not free from regulations as yet due to the problems of unreality of support projects, and hierarchy of ordinances, etc. Accordingly, this study implemented this research under the judgment that it's about time to mitigate overlapping regulations on regional characteristics of the border areas of Incheon Metropolitan City, i.e. different land use regulation as a border area. It is required that general land use regulations should be mitigated through f lexible deregulation & management of the military regulation on the border areas of Incheon-si, mitigation of regulations under the Metropolitan Area Readjustment Planning Act, and relaxation of the preservation area of cultural properties; particularly, it's necessary to minimize the damage to border areas of Incheon-si caused by overlapping regulations on the areas by exempting the areas from the range of a metropolitan area through acknowledgment of the difference between the distinct characteristics of the border areas and regional, cultural conditions of a metropolitan area.

• Journal of Broadcast Engineering
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• v.6 no.3
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• pp.246-259
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• 2001

Due to recent rapid deployment of Internet streaming service and digital broadcasting service, the issue of how to efficiently support streaming workload in so called "Internet Home Appliance" receives prime interests from industry as well as academia. The underlying dilemma is that it may not be feasible to put cutting edge CPU, boards, disks and other peripherals into that type of device. The primary reason is its cost. Usually, Internet Home Appliances has its dedicated usage, e.g. Internet Radio, and thus it does not require high-end CPU nor high-end Va subsystem. The same reasoning applies to I/O subsystem. In Internet Home Appliances dedicated to handle compressed moving picture, it is not equipped with high end SCSI disk with fast rotational speed. Thus, it is mandatory to devise elaborate software algorithm to exploit the available hardware resources and maximize the efficiency of the system. This paper presents our experiences in the design and implementation of a new multimedia file system which can efficiently deliver the required disk bandwidth for a periodic I/O workload. We have implemented the file system on the Linux operating system, and examined itsperformance under streaming I/O workload. The results of the study show that the proposed file system exhibits superior performance than the Linux Ext2 file system under streaming I/O workload. The result of this work not only contribute to advance the state f art file system technology for multimedia streaming but also put forth the software which is readily available and can be deployed. deployed.

• Journal of Korean Society of Steel Construction
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• v.23 no.2
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• pp.199-210
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• 2011

The cables in cable-stayed bridges are under high stress and are very sensitive to vibration due to their small section areas compared with other members. Therefore, it is reasonable to evaluate the cable impact factor by taking into account the dynamic effect due to moving-vehicle motion. In this study, the cable impact factors were evaluated via moving-vehicle-load analysis, considering the design parameters, i.e., vehicle weight, cable model, road surface roughness, vehicle speed, longitudinal distance between vehicles. For this purpose, two steel composite cable-stayed bridges with 230- and 540-m main spans were selected. The results of the analysis were then compared with those of the influence line method that is currently being used in design practice. The road surface roughness was randomly generated based on ISO 8608, and the convergence of impact factors according to the number of generated road surfaces was evaluated to improve the reliability of the results. A9-d.o.f. tractor-trailer vehicle was used, and the vehicle motion was derived from Lagrange's equation. 3D finite element models for the selected cable-stayed bridges were constructed with truss elements having equivalent moduli for the cables, and with beam elements for the girders and the pylons. The direct integration method was used for the analysis of the bridge-vehicle interaction, and the analysis was conducted iteratively until the displacement error rate of the bridge was within the specified tolerance. It was acknowledged that the influence line method, which cannot consider the dynamic effect due to moving-vehicle motion, could underestimate the impact factors of the end-cables at the side spans, unlike moving-vehicle-load analysis.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.308-319
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• 2016

In order to evaluate the role of macrophytes as refuge of zooplankton on physical distribution (i.e. summer rainfall), we investigated the environmental factors, macrophytes, and zooplankton in waterside zones (macrophytes zones) and open water zones of 17 wetlands from May and August, 2011. In this study, a total of 51 zooplankton species were identified, and Polyarthra sp. and Diaphanosoma brachyurum were found to be the most dominant species. Waterside area of each wetland were occupied by a total of 10 macrophyte species, species composition and biomass (dry weight) were different in the survey sites. Zooplankton was more abundant in waterside zone than open water zones lacking macrophytes (One-way ANOVA, df=2, F=27.1, P<0.05), in particular, waterside zone of 1, 8, 9, 10, and 11 wetland were supported by high zooplankton density after summer rainfall. This wetlands were developed by various macrophyte species than other wetland, and submerged plant commonly presented. Waterside zones with various macrophyte species provides complexity to the habitat structure, should be utilized as refuge to avoid disturbance such as summer rainfall. The results indicate that macrophytes are the key components to enhance bio-diversity include zooplankton, and the inclusion of diverse plant species in wetland construction or restoration schemes will result in ecologically healthy food webs.