• Food Science and Biotechnology
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• v.14 no.6
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• pp.828-831
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• 2005

The content of vitamin $D_2$, including its precursor ergosterol, was determined in some cultivated mushrooms to manufacture fortified Doenjang (Korean traditional soybean paste) with vitamin D by supplementation with mushroom. Ergosterol was the most abundant sterol in the mushrooms (50 to 140 mg/100 g dry weight) but the ergocalciferol portion made up only 0.065% (Pleurotus eryngii) to 2.5% (stipe part of Lentinus edodes, shiitake) of the total vitamin $D_2$ of each mushroom. Changes in these compounds in L. edodes caused by UV or solar irradiation were also evaluated. Ergocalciferol content in the pileus part of L. edodes went up to $424\;{\mu}g/100\;g$ dry weight and ergosterol levels reached 139.3 mg per 100 g dry weight at maximum levels. Ergocalciferol content increased about 50% when exposed to solar radiation and increased 377% with UV irradiation. These compounds level in Doenjang was enriched as much as supplied UV irradiated L. edodes powder to before fermentation, and the supplemented mushroom did not influence the palatability of Doenjang.

• International Journal of Industrial Entomology and Biomaterials
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• v.43 no.2
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• pp.67-77
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• 2021

Salurnis marginella Guérin-Méneville, 1829 (Hemiptera: Flatidae) is an invasive species first reported in 2003 in Iksan, which is located in the mid-western region of South Korea, and subsequently found in the nearby regions in 2005. However, molecular-perspective reports on their invasive characteristics are not yet available. In this study, population genetic characteristics of Korean S. marginella were evaluated using the mitochondrial COI region and sequencing 124 individual samples collected in 11 Korean localities. A total of 12 haplotypes were identified with a maximum sequence divergence of 1.368% (9 bp). Haplotype diversity was relatively higher than that of other insect species invaded into Korea, providing 2-6 haplotypes per populations, indicating that introduction to Korea may have happened rather extensively and consistently. Nucleotide diversity (π) was the highest in Iksan but owing to the limited sample size (three individuals) from this locality, additional studies are required for drawing conclusive inference regarding the place of entry to Korea. Ulsan, the easternmost population in the present study, revealed nearly the lowest diversity estimates, such as the lowest H and the second-lowest π; a unique haplogroup with a higher frequency; and an independent genetic cluster, suggesting that the introduction of S. marginella to Ulsan was an independent event. Further collection in Korea and neighboring countries, including the original distributional range is necessary to elucidate the invasive dynamics of S. marginella

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.316-319
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• 2006

Connectionist networks, also called neural networks, have been broadly applied to solve many different problems since McCulloch and Pitts had shown mathematically their information processing ability in 1943. In this thesis, we present a genetic neuro-control scheme for nonlinear systems. Our method is different from those using supervised learning algorithms, such as the backpropagation (BP) algorithm, that needs training information in each step. The contributions of this thesis are the new approach to constructing neural network architecture and its training.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.320-323
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• 2006

Recently, retrieval of various video data has become an important issue as more and more multimedia content services are being provided. To effectively deal with video data, a semantic-based retrieval scheme that allows for processing diverse user queries and saving them on the database is required. In this regard, this paper proposes a semantic-based video retrieval system that allows the user to search diverse meanings of video data for electrical safetyrelated educational purposes by means of automatic annotation processing. If the user inputs a keyword to search video data for electrical safety-related educational purposes, the mobile agent of the proposed system extracts the features of the video data that are afterwards learned in a continuous manner, and detailed information on electrical safety education is saved on the database. The proposed system is designed to enhance video data retrieval efficiency for electrical safety-related educational purposes.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.81-84
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• 2007

Ab initio periodic Hartree-Fock calculations with the full potential and minimum basis set are applied to interpretation of scanning tunneling microscope (STM) and atomic force microscope (AFM) images on 1TVTe2. Our results show that the simulated STM image shows asymmetry while the simulated AFM image shows the circular electron densities at the bright spots without asymmetry of electron density to agree with the experimental AFM image. The bright spots of both the STM and AFM images of VTe2 are associated with the surface Te atoms, while the patterns of bright spots of STM and AFM images are different.

• Korean Journal of Materials Research
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• v.14 no.9
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• pp.649-654
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• 2004

In this paper, the fracture toughness and mechanisms of failure in a random SiC-whisker/$Al_{2}O_3$ ceramic composite were investigated using in situ observations during mode I(opening) loading. $SiC_{w}/Al_{2}O_3$ composite was obtained by hot press sintering of $Al_{2}O_3$ powder and SiC whisker as the matrix and reinforcement, respectively. The whisker and powder were mixed using a turbo mill. The composite was produced at SiC whisker volume fraction of $0.3\%$. Compared with monolithic $Al_{2}O_3$, fracture toughness enhancement was observed in $SiC_{w}/Al_{2}O_3$ composite. This improved fracture toughness was attributed to SiC whisker bridging and crack deflection. $SiC_{w}/Al_{2}O_3$ composite exhibited typically brittle fracture behavior, but a fracture process zone was observed in this composite. This means that the load versus load-line displacement curve of $SiC_{w}/Al_{2}O_3$ composite from a fracture test may involve a small non-linear region near the peak load.

• Journal of Welding and Joining
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• v.23 no.6
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• pp.67-71
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• 2005

This paper is concerned with a study on fracture strength of composites in an adhesive single lap joint. The tests were carried out on joint specimens made with hybrid stacked composites consisting of the polyester and bamboo natural fiber layer. The main objective of this work was to evaluate the fracture properties adjacent to adhesive bonded joint of natural fiber reinforced composite specimens. From the results, natural fiber reinforced composites have lower tensile strength than the original polyester. But tensile-shear strength of natural fiber reinforced composites with bamboo layer far from adhesive bond is as high as that of the original polyester adhesive bonded joints. Spew filet at the end of the overlap reduced the stress concentration at the bonded area. Spew fillet and position of bamboo natural fiber layer have a peat effect on the tensile-shear strength of natural fiber reinforced composites including adhesive bonded joints.

• Journal of Environmental Impact Assessment
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• v.20 no.4
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• pp.497-507
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• 2011

This research studied human health risk assessment of benzene from industrial complexes of Chungcheong Province (Seosan industrial complex) and Jeonla Province (Iksan industrial complex and Yeosoo industrial complex). The residents near the industrial complexes areas can be often exposed to volatile organic compounds (e.g., benzene, toluene, xylenes) through a number of exposure pathways, including inhalation of the organic pollutant via various environmental matrices (air, water and soil), contaminated water, and soil intake. Benzene is well known to be a common carcinogenic and toxic compound that is produced from industrial and oil refinery complexes. In this study, a number of samples from water, air, and soil were taken from the residential settings and public school zones located near the industrial complex sites. Based on the carcinogenic risk assessment, the risk estimates were slightly above $10{\times}10^{-6}$ at all three industrial sites. According to deterministic risk assessment, inhalation was the most important route. The distribution of benzene in the environment would be dependent on vapor pressure, and the physical property influencing the extent of the potential risks. Non-carcinogenic risk assessment of benzene shows that the values of Hazard Index(HI) were much lower than 1.0 at all industrial complexes. Therefore, benzene was not a cause of concern in terms of non-carcinogenic risk posed to the residents near the sites. When compared to probabilistic risk assessment, the CTE(central tendency exposure) cancer risk values of deterministic risk assessment were close to the mean values predicted by the probabilistic risk assessment. The RME(reasonable maximum exposure) values fell within the range of 95% to 99.9% estimated by the probabilistic risk assessment. Since the values of carcinogenic risk assessment were higher than $10{\times}10^{-6}$, further detailed monitoring and refined risk assessment for benzene may be warranted to estimate more reliable and potential inhalation risks to receptors near the industrial complexes.

• Journal of the Economic Geographical Society of Korea
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• v.6 no.2
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• pp.307-326
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• 2003

In Korea, as the state has played a vital role for industrial development, the location and development of industrial complexes have not been merely decided by economic factors but political and social factors as well. The location of industrial complexes in Chonbuk province has not been decided by industrial enterprises to be located there, but by investment strategies of the state. In the early stage of industrialization, Chonbuk could not attract a large-scale major complex because it had relatively inferior infrastructure for industry and uneasy access to overseas export markets, as compared to the capital region or the Southeast region of the country, and it has been left behind as a periphery in the national industrial system. Since 1980, the spatial policies for lessening regional disparities had much contributed to the development of industrial complexes in this province. The industrial complexes leading to the development of manufacturing activities in this region have also great influenced on structural changes of manufacturing as well as changes in the structure of the regional economy. Especially, capital goods manufacturing tends to increase in this region as the development of sectors required relative higher skill and technology mainly occurs in these complexes. And where the large-scale industrial complexes are located greatly influences the locational patterns of manufacturing in this province. The patterns of the industrial complexes in this region have concentrated in Chonju, Iksan, and Kusan, which are the largest cities in this province. Given these three cities to be very closely proximate, it seems to be easy to build network between them to develop the manufacturing activities in the near future.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.41-48
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• 2003

Two experiments were conducted to investigate the effect of dietary supplementation of yeast culture on the performance of broiler chicks and noxious gas emission in broiler houses. Two hundred forty and three hundred and twenty, one day old Cobb male broiler chicks in Expt 1 and Expt 2, respectively were alloted to four treatment levels of yeast culture (0, 0.1, 0.2, 0.4%). To each treatment, 60 birds were assigned in Expt 1 and 5 replicates of 16 birds each were assigned in Expt 2. Basal diets contained 21.5% and 19.0% CP, and 3,100kcal/kg ME for the starting and finishing periods, respectively. Ammonia and $CO_2$ gas emission were detected twice a day for seven days during the five week period of Expt 1. Weight gain, feed intake and feed efficiency were measured for five weeks in Expt 2. Intestinal microbes, blood cholesterol and ND antibody titer were examined at the end of Expt 2. In Expt 1, the concentration of $NH_3$ in the house of birds fed yeast culture tended to be lower than the control. It was significantly lower in the 0.4% yeast culture treatment than the control (P<0.05). $CO_2$ concentration was significantly lower in all yeast culture treatments regardless of its dietary supplemental level than the control (P<0.05). different from others. Feed efficiency (feed/gain), however, was significantly improved in all yeast culture treatments relative to that of the control for starting period (P<0.05) and that of 0.2% yeast culture treatment was significantly lower than those of the control and 0.4% for the overall period. Total number of E. coli in the ileum of birds fed yeast culture at 0.1 and 0.2% was significantly lower than those of the control and 0.4% in the ileum. The CFU of Lactobacillus spp. of birds fed yeast culture at 0.1% was higher in the cecum compared to other treatments (P<0.05). Total cholesterol level of chicks fed 0.1% yeast culture seemed to be lower compared to that of other treatments, whereas LDL-cholesterol level was significantly lower than those of the control and 0.4% treatment. ND antibody titer tended to be higher in the yeast culture treatments than the control, but was not significantly different. The results of these experiments indicated that 0.2% yeast culture may have a potential to reduce the noxious gas emission in broiler houses and maximize the performance of broiler chicks.