• Journal of the Korean association of regional geographers
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• v.15 no.3
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• pp.369-392
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• 2009

Recently international movements of labour as well as those of goods and other production elements such as capitals and technology have been increased rapidly under the process of glocalization. The huge amount of immigrant workers' in-flows makes increasing influences on regional economy in South Korea. This paper examines such impacts of immigrant workers on local labor markets, productivity. and industrial composition and innovation on the basis of analysis of empirical data and review of existing literature on the subject. Despite a problem of simplification, some reasoning can be listed as follows: First of all, the inflow of immigrant workers has an effect of job displacement among domestic simple workers, with duel effects on the status of native workers; secondly, Immigrant workers give a positive effect on local productivity, but only with low level of wage and of purchasing power; thirdly, the in-flow of immigrant workers seems to prevent existing industries from transformation towards new ones and/or from automation and innovation of production facilities, while there seems no clear relationship with foreign direct investments of local firms.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.21-28
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• 2006

In this paper, the proposed full-bridge high frequency isolated zoo voltage and zero current switching phase shifted pulse width modulation(ZVZCS PS-PWM)DC-DC converter among fuel cell generation system consist of 1.2[kW] fuel cell of Nexa Power Module, full-bridge DC-DC converter to boost the fuel cell low voltage($28{\sim}43[%]$) to 380[VDC] and a single phase full-bridge inverter is implemented to produce AC output(220[VAC], 60[Hz]). A tapped inductor filter with freewheeling diode is newly implemented in the output filter of the proposed full-bridge high frequency isolated ZVZCS PS-PWM DC-DC converter to suppress circulating current under the wide output voltage regulation range, thus to eliminate the switching and transformer turn-on/off over-short voltage or transient phenomena. Besides the efficiency of $93{\sim}97[%]$ is obtained over the wide output voltage regulation ranges and load variations.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1069-1077
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• 2009

Lately, it is an important concern in water resources research to maintain a stable water supply according to a future climate change and an increase in water use. In Han-River basin, approximately 10 % of water resources that is provided the capital region (Gyeonggi, Seoul etc.) has been reduced as a consequence of the construction of Imnam Dam (storage volume: 27 billion $m^3$) located in the upper Hwacheon Dam upstream area. Therefore, streamflows have decreased in Bukhangang basin, but it could not be evaluated quantitatively. In this study, SWAT-K which is the physically based long-term runoff simulation model, was used in order to evaluate the effect of Imnam Dam on the reduced inflow to Hwacheon Dam according to the change of hydrological condition in the upstream area of Hwacheon Dam. For the model input data of North Korea area, meteorological data of GTS (Global Telecommunication System) were used, and soil maps by FAO/UNESCO (2003) were applied. Temporal variations of water resources is investigated with comparison of observed and simulated inflows at Hawcheon Dam site. Also, annual, monthly, seasonal decreases in water resources were evaluated using the flow duration analysis of simulated streamflows with or without Imnam dam.

• Journal of the Korea Computer Graphics Society
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• v.16 no.1
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• pp.1-7
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• 2010

With the widespread use of vision-based surveillance systems, the capability for person identification is now an essential component. However, the CCTV cameras used in surveillance systems tend to produce relatively low-resolution images, making it difficult to use face recognition techniques for person identification. Therefore, an algorithm is proposed for person identification in CCTV camera images based on the clothing. Whenever a person is authenticated at the main entrance of a building, the clothing feature of that person is extracted and added to the database. Using a given image, the clothing area is detected using background subtraction and skin color detection techniques. The clothing feature vector is then composed of textural and color features of the clothing region, where the textural feature is extracted based on a local edge histogram, while the color feature is extracted using octree-based quantization of a color map. When given a query image, the person can then be identified by finding the most similar clothing feature from the database, where the Euclidean distance is used as the similarity measure. Experimental results show an 80% success rate for person identification with the proposed algorithm, and only a 43% success rate when using face recognition.

• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.452-459
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• 1990

A series of oxo-and sulfido-bridged molybdenum (V) complexes, Mo$_2$O$_4$L$_2$, Mo$_2$O$_3$L$_4$, Mo$_2$O$_2$S$_2$L$_2$, and Mo$_2$OS$_3$L$_2$ [L = bis(hydroxyethyl)dithiocarbamate] have been prepared. The complexes with bridging and terminal oxo groups have been synthesized by the reactions of (PyH)$_2$MoOCl$_5$ or MoCl$_5$ and ligand in water. One of the rest two complexes, in which bridging and terminal oxo groups have been replaced by sulfido in Mo$_2$O$_4^{2+}$ core, Mo$_2$O$_2$S$_2$L$_2$ have been prepared by addition of triphenylphosphine to a chloroform solution of Mo$_2$OS$_3$L$_2$. While, Mo$_2$OS$_3$L$_2$ is obtained from aqueous solution of (NH$_4$)$_2$MoS$_4$ and ligand in the presence of sodium dithionite. The complexes are identified by elemental analysis, and spectral data of IR, UV-vis, nmr, and mass. Also, the electrochemical behaviour for the complexes in dimethylsulfoxide has been investigated by the cyclic voltammograms.

• Journal of Life Science
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• v.20 no.4
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• pp.614-617
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• 2010

We sequenced a 522 bp fragment including the $tRNA^{Thr}$, $tRNA^{Pro}$ gene and the first half of the control region from 29 wild and cultured olive flounder specimens from Korea. Out of 522 nucleotide sites, 49 (9.4%) were variable, 23 haplotypes being found. Most haplotypes are unique in the wild population and only four were shared by cultured specimins. The nucleotide diversity and differences between wild and cultured populations were $0.025{\pm}0.013$ and $0.015{\pm}0.008$, and $12.94{\pm}6.00$ and $7.83{\pm}3.75$, respectively. Haplotype diversity was $0.98{\pm}0.02$ and $0.49{\pm}0.09$ in the wild and cultured populations, respectively. These results show that marked reductions of genetic variability in the hatchery strains were observed in the number of mitochondrial DNA haplotypes and haplotype diversity when compared to the wild populations. Furthermore, we detected significant population differentiation between both populations. The mtDNA sequencing technique used to evaluate the genetic variability of hatchery strains compared to that of the wild population is potential for genetic monitoring of olive flounder hatchery stocks.

• Journal of Life Science
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• v.20 no.4
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• pp.618-622
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• 2010

This study examines the relationship between urinary arsenic concentration and urinary 8-hydroxydeoxyguanosine (8-OHdG) concentrations, an index of oxidative DNA damage, among women who live near abandoned metal mines. The sample consisted of 165 residents living near two abandoned metal mines located in Chungbuk Province. Demographic characteristics as well as environmental factors relevant to arsenic exposure were collected through interviews, and urinary arsenic concentrations and urinary 8-OHdG concentrations of the research subjects were measured. The collected data were subsequently analyzed using the statistics program SPSS 12.0. The geometric average of urinary arsenic concentrations among the research subjects was $5.65\;{\mu}g/g$ creatinine. In a correlation analysis between urinary arsenic and 8-OHdG concentrations, the correlation coefficient was significant (p<0.001) at 0.399. This study suggests that urinary 8-OHdG concentrations may be a DNA damage marker for chronic arsenic exposure in women.

• Journal of Life Science
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• v.20 no.4
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• pp.632-638
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• 2010

The genetic diversity among 48 persimmon (Diospyros kaki Thunb.) accessions, indigenous in Korea and introduced from Japan and China, was evaluated by using simple sequence repeat (SSR) markers. From 20 SSR primer sets, a total of 114 polymorphic markers were detected among 12 pollination-constant non-astringent (PCNA), 13 pollination-variant non-astringent (PVNA), 15 pollination-variant astringent (PVA), and 8 pollination-constant astringent (PCA) cultivars. Analysis of pair-wise genetic similarity coefficient (Nei-Li) and unweighted pair-group method with arithmetic averaging (UPGMA) clustering revealed two main clusters and four subclusters for cluster I. The subclustering pattern was in accordance with the classification of persimmon cultivars based on the nature of astringency loss. Phenetic relationships among the subclusters showed a closer relatedness of the PCNA group with the PVNA group, and the PVA with the PCA group. Genetic similarity co-efficiency was 0.499 on average and the highest (0.954) similarity was observed between 'Cheongdo-Bansi' and 'Haman-Bansi'. The similarity was lowest (0.192) between 'Damopan'and 'Atago'. Identification of each cultivar with the execption of 'Cheongdo-Bansi' and 'Gyeongsan-Bansi' was possible based on the SSR fingerprints, suggesting that these SSR markers are a useful tool for protecting intellectual property on newly developed cultivars.

• Journal of Life Science
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• v.20 no.4
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• pp.481-486
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• 2010

The rates of synonymous and nonsynonymous nucleotide substitutions were studied for sequences of nuclear and chloroplast genes in Sorbus aucuparia. Results suggested that DNA evolution in this species had taken place, on average, at a slower rate in the chloroplast genes than in the nuclear genes: a rate variation pattern similar to those observed in eudicot plants. Within the nucleus, the synonymous substitution rates (Ks) (2.45-2.60) were two-fold higher than nonsynonymous substitution rates (Ka) (1.15-1.30). More notably, the values of Ks (1.20-1.26) were about six-fold higher than those of Ka (0.26-0.42) within the chloroplast genome. Ka/Ks ratios for nuclear and chloroplast genes of S. aucuparia had mean values of 0.178 and 0.056, respectively. A Ka/Ks ratio < 1 indicated negative (purifying) selection. The chloroplast genes had a lower effective number of codons (ENC) values (22.4-32.2) than those of nuclear genes (35.8-38.7). The analysis of the G+C content indicated that the chloroplast genes in this investigation had a higher preference for synonymous codons ending with A and T (G+C content range, 28.4-29.1%) where there was a slight bias toward codons ending with G+C (63.2-64.2%) in the nuclear genome.

• Journal of Life Science
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• v.20 no.4
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• pp.487-495
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• 2010

A microorganism hydrolyzing carboxymethylcellulose (CMC) was isolated from seawater, identified as Psychrobacter aquimaris by analysis of 16S rDNA sequences, and named P. aquimari LBH-10. This strain produced an acidic carboxymethylcellulase (CMCase), which hydrolyzed carboxymethylcellulose (CMC), cellobiose, curdlan, filter paper, p-nitrophenyl-$\beta$-D-glucopyranoside (pNPG), pullulan, and xylan, but there was no detectable activity on avicel and cellulose. The optimal temperature for CMCase produced by P. aquimari LBH-10 was $50^{\circ}C$ and more than 90% of its original activity was maintained at broad temperatures ranging from 20 to $50^{\circ}C$ after 24 hr. The optimal pH of the CMCase was 3.5, and more than 70% of its original activity was maintained under acidic conditions between pH 2.5 and 7.0 at $50^{\circ}C$ after 24 hr. The optimal pH of CMCase produced by P. aquimaris LBH-10 seems to be lower than those produced by any other bacterial and fungal strain. $CoCl_2$, EDTA, and $PbCl_2$ at a concentration of 0.1 M enhanced CMCase-produced P. aquimaris LBH-10, whereas $HgCl_2$, KCl, $MnCl_2$, $NiCl_2$, and $SrCl_2$ inhibited it.