• Korean Journal of Environmental Biology
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• v.31 no.1
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• pp.19-36
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• 2013

Physiochemical characters of sea waters during summer flood- and winter dry-seasons and their spatial variations were investigated along the coastal area off the eastern South Sea, Korea. Using the hierarchical clustering method, in this study, we present comprehensive analyses of coastal waters masses and their seasonal variations. The results revealed that the coastal water of the study area was classified into six water masses (A to F). During summer season, the surface water was mainly occupied by the coastal pseudo-estuarine water (water mass B) with low salinity and high nutrients and the river-dominated coastal water (water mass C) with low nutrients, respectively. The bottom water was dominated by cold water (water mass D) with very low temperature, high salinity and high nutrients, compared to masses of surface water. Notably, the water mass B, with high concentrations of nutrients (silicate and nitrogen) and low salinity, which is strongly controlled by the water quality of river freshwater, seems to play an important role in controlling the water quality and further regulating physical processes on ecosystem in the eastern coastal area of South Sea. The water mass D (bottom cold water) coupled with a strong thermocline, which exists in near-bottom layer along the western margin of Korea Strait, has a low temperature, pH and DO, but abundant nutrients. This water mass disappears in winter owing to strong vertical mixing, and subsequently may act as a pool for nutrients during winter dry-season. On the other hand, vertically well-mixed water column during the winter season was typically occupied by the Tsushima (water mass E) and the coastal water (water mass F) with a development of coastal front formed in a transition zone between them. These winter water masses were characterized by low nutrient concentration and balance in N/P ratio, compared with summer season with high nutrient concentrations and strong N-limitation. Accordingly, the analysis of water masses will help one to better chemical and biological processes in coastal area. In most of the study area, characteristically, the growth of phytoplankton community is limited by nitrogen, which is clearly different with coastal environment of West Sea of Korea, with a relative lack of phosphorus. It showed the western and the southern coasts in Korea are substantially different from each other in environmental and ecological characteristics.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.105-110
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• 2007

This experiment was conducted to investigate the effects of stocking density on performance and blood characteristics of broiler chicken in summer. One day-old 648 male commercial broiler chicks(Ross strain) were divided into 3 groups with 4 replicates(12 pens), 41 to 69 birds per pen, to compare the stocking density difference on growth performance and blood characteristics. Birds in T1, T2 and T3 were reared in different size 0.050, 0.066, 0.083 $m^2$/bird floor, respectively. The birds were fed the same experimental diet ad libitum for 5 weeks. Chickens were weekly weighed and one bird was selected from each pen to measure blood characteristics at the end of experiment. Body weight and feed intake increased significantly in low density treatment(T3) compare to that of high density treatment(P<0.05). Feed conversion was significantly improved in customary treatment(T2) relative to that of other treatments(P<0.05). No significant difference was observed in moisture contents of bedding among treatments. In blood characteristics, low density treatment(T3) decreased the total protein, cholesterol and albumin, but were no significant difference. From the result of this study, it could be concluded that the higher stocking density might give more stress to the birds from physical stimuli and thus were harmful environment causing lower productions compared to the lower ones

• Korean Journal of Poultry Science
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• v.41 no.2
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• pp.105-113
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• 2014

The current study was performed to investigate the effects of dietary supplementation of dried coffee meal (CM) on growth performance, intestinal and blood biochemical index, intestinal enzymes, and cecal microbial populations. A total of 162, 3-day-old male broiler chicks were randomly allocated into three dietary groups: control group (CON), basal diet added with 0.5% CM (CM I), and basal diet added with 1.0% CM (CM II). Dietary supplementation of CM did not change bird performance and the relative weight of intestinal mucosal tissues. The birds fed the diet supplemented with CM (0.5 and 1.0%) significantly decreased mucosal glucose concentration (P<0.05) without affecting blood glucose level compared with those fed control diet. The level of blood aspartate aminotransferase (AST) significantly increased in CM II group (P<0.05) without affecting ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GTP) compared with that in the CON group. The specific activity of intestinal maltase, leucine aminopeptidase (LAP) and alkaline phosphatase (ALP) were not affected by dietary supplementation of CM, whereas sucrase activity in birds fed the diet supplemented with CM was decreased (P<0.05) compared to that in the control birds. The colony forming units (CFU) of E. coli in the cecum of CM-fed birds was significantly decreased (P<0.05) compared with that of control birds without changing the CFU of Lactobacillus. In conclusion, dietary supplementation of lower level of CM (0.5%) can be used as a beneficial feed resource without liver toxicity in broiler chicks.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.182-187
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• 2013

In closed plant production system like plant factory, changes in environmental factors should be identified for conducting efficient environmental control as well as predicting energy consumption. Since high relative humidity (RH) is essential for crop production in the plant factory, transpiration is closely related with RH and should be quantified. In this study, four varieties of lettuces (Lactuca sativa L.) were grown in a plant factory, and the leaf areas and transpiration rates of the plants according to DAT (day after transplanting) were measured. The coefficients of the simplified Penman-Monteith equation were calibrated in order to calculate the transpiration rate in the plant factory and the total amount of transpiration during cultivation period was predicted by simulation. The following model was used: $E_d=a*(1-e^{-k*LAI})*RAD_{in}+b*LAI*VPD_d$ (at daytime) and $E_n=b*LAI*VPD_n$ (at nighttime) for estimating transpiration of the lettuce in the plant factory. Leaf area and transpiration rate increased with DAT as exponential growth. Proportional relationship was obtained between leaf area and transpiration rate. Total amounts of transpiration of lettuces grown in plant factory could be obtained by the models with high $r^2$ values. The results indicated the simplified Penman-Monteith equation could be used to predict water requirements as well as heating and cooling loads required in plant factory system.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.483-494
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• 2006

We conducted QTL mapping for 6-year growths of open-pollinated half-sib progenies from a selected clone 7-1037 in Pinus taeda. With an AFLP marker analysis on haploid DNA samples from the megagametophytes of the open-pollinated seeds, we constructed 20 framework maps spanning a total of 1,869 cM in total length and 18.5 cM in an average interval length between markers. Composite interval mapping reveals that one QTL explains 5.9% of the total phenotypic variation of height, and three QTLs account for 3.9~5.6% of the variation of diameter at breast height (DBH). There are no correlations between the QTLs. The genetic effects of the QTLs are 39.6 cm in height and 7.20~9.41 mm in DBH, respectively, The average effects of gene substitution of the markers closely linked with the QTLs are 44.3 cm in height and 8.38~11.81 m in DBH. Under an assumption that the within-family heritability for the growth traits of loblolly pine is less than 0.2, the QTLs account for 26.8% of the additive genetic variance of the progenies. In terms of relative selection efficiency, the individual selection based on QTL markers could be 5 times as high as phenotypic selection. The results in this study indicate that the QTL mapping method with open-pollinated half-sib family could be more practical and applicable to the conventional seed orchard-based selection work than other mapping methods with a single full-sib family, in particular from the viewpoint that it can provide crucial information for within-family individual selection such as breeding value.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.399-404
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• 1997

This paper is presenting a practical result of environmental manipulation effect on pine mushroom Tricholoma matsutake yield and a discussion of key factor seeking for improving pine mushroom production by analyzing the effects on mushroom yield for 10 years with applying five kinds of environmental control at the pine stands located in Namwon, Chollabuk-do, Korea. The environmental controls included density control and forest floor manipulations, and the treatments were applied during early summer of 1983. The mushroom yield itself did not show statistically significant differences among the treatments. But, we could manifest the treatment effects by calculating the relative yield in percent on the basis of pretreatment yield collected in 1982. The forest floor manipulation with density control may affect pine mushroom yield in short term, and continuous management should be applied to keep and improve the mushroom production. The fine root activity was the most important factor of pine mushroom production at the Namwon research site since the floor raking resulted in the largest effect on the mushroom yield although the environmental condition for the growth of fungi is important for pine mushroom production. In addition, the pine mushroom forest with sandy soils demands adequate litter layer since the litter removal showed relatively detrimental effects on pine mushroom yield compared to that in litter covered plot at the research site. That is, soil texture should be considered for forest floor manipulation, and it is reconfirmed that the environmental control to improve pine mushroom production should be applied differently by each region.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.12
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• pp.1734-1740
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• 2001

Feeding trials using weanling pigs and broiler chicks were conducted to evaluate the efficacy of different metal-amino acid chelates and complexes at various levels of copper and zinc on the performance and fecal excretions. A total of 200 weanling pigs (Large White ${\times}$ Yorkshire ${\times}$ Duroc, $11.20{\pm}0.81kg$) were randomly assigned to 5 dietary treatments following a randomized complete block design. Each treatment was replicated 4 times with 10 pigs per pen. The dietary treatments were designated as : A-diet containing 170 ppm Cu from $CuSO_4$ and 120 ppm Zn from $ZnSO_4$, B-diet containing 85 ppm Cu from Cu-amino acid chelate (CAC) and 60 ppm Zn from Zn-amino acid chelate (ZAC), C-diet containing 170 ppm Cu from CAC and 120 ppm Zn from ZAC, D-diet containing 85 ppm Cu from Cu-lysine complex (CL) and 60 ppm Zn from Zn-methionine complex (ZM), and E-diet containing 170 ppm Cu from CL and 120 ppm Zn from ZM. On the other trial, 144 of one day old broiler chicks were randomly distributed to 6 dietary treatments following a completely randomized design. Each treatment was replicated 3 times with 8 chicks per replicate. The dietary treatments were as follows: 1-diet with 60 ppm Cu from $CuSO_4$ and 40 ppm Zn from $ZnSO_4$, 2-diet with 120 ppm Cu from $CuSO_4$ and 80 ppm Zn from $ZnSO_4$, 3-diet with 60 ppm Cu from CAC and 40 ppm Zn from ZAC, 4-diet with 120 ppm Cu from CAC and 80 ppm Zn from ZAC, 5-diet with 60 ppm Cu from CL and 40 ppm Zn from ZM, and 6-diet with 120 ppm Cu from CL and 80 ppm Zn from ZM. In Exp. 1 with pigs, there was no difference on average daily gain and average daily feed intake observed among treatments. There was improvement (p<0.05) on the overall feed conversion ratio (FCR) of pigs fed diet containing 120 ppm Zn and 170 ppm Cu from metal-amino acid chelates relative to those fed diet containing inorganic sources of Cu and Zn but equally efficient as those fed diet containing metal-amino acid complexes. Pigs fed diet containing either metal-amino acid chelates or complexes as sources of Cu and Zn had higher (p<0.05) Cu and Zn concentration in serum and lower (p<0.05) in feces than those receiving diet with inorganic sources. In Exp. 2 with broiler chicks, the overall FCR was not different among treatments. Higher (p<0.05) Cu and Zn concentration in serum was obtained from birds fed diet with 60 ppm Cu and 40 ppm Zn from metal-amino acid chelates compared to those fed diet with inorganic sources of Cu and Zn. Also, the feces collected from birds fed diet with either metal-amino acid chelates or complexes contained generally lower Cu and Zn than those birds fed diet with inorganic sources. The higher the dietary level of Cu and Zn the higher the Cu and Zn concentration in the feces. Based on the results, both metal-amino acid chelates and complexes of Cu and Zn at low levels (Zn 60 ppm, Cu 85 ppm for weanling pigs and Zn 40 ppm, Cu 60 ppm for broiler chicks) are not different from that of high levels of inorganic sources in maintaining growth performance and serum concentration. The fecal excretions for Cu and Zn were greatly reduced when organic sources were used.

• Journal of Nutrition and Health
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• v.3 no.3
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• pp.129-135
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• 1970

From the previous studies, F-P-4 formula was found to be comparable to full fat dry milk in its nutritive value and feeding performance. However, an attempt was made in order to make sure whether or not any possibility might exist, by which further improvement of nutritive quality and simultaneous reduction of product costs may be achieved. Using F-P-4 as a control, modifications were made in new formulas, F-P-5, F-P-6 and F-P-7 by reducing FPC, eliminating yeast from the mixture, and by enriching with methionine as needed. In particular, F-P-7 is completely free of FPC, hydrogenated oil and yeast. Yet, levels of total protein and fat were kept equal to those of F-P-4 in all formulas. An animal feeding test for all formulas using 10 female rats per group for 8 weeks and an infant feeding trial for F-P-5 and F-P-6 with 5 of each female infants under age of one for one month were conducted along with F-P-4 as a control. Almost the same results were obtained with F-P-4, 5 and 6, but F-P-7 showed the lowest body weight gain. FER of F-P-5 and 6 was 0.20 as was with F-P-4, while that of F-P-7 was 0.16. Acceptability to infants was excellent; growth, appearance and biochemical data were normal. As an example F-P-4 packed in 0.04mm polyethylene bags was used for storage study at $25^{\circ}C$ and relative humidity of $65{\sim}85%$ for 8 months. Although viable bacterial counts and vitamin C contents were reduced, peroxide and TBA values were increased gradually during such storage. Since there are also significant changes in color and organoleptic quality, the expected shelf life under the given conditions is considered to be about 2 months and thus further works are needed both on the product and packaging in order to improve the storage stability. Either elimination of yeast form F-P-4, that is F-P-5, or partial replacement of FPC with methionine, that is F-P-6 may well reduce material costs about 10%. Considering blending process of ingredients, F-P-5 is thus found to be the best formula developed. While F-P-7 free of FPC is inferior in its nutritive quality than that of others, but significantly superior than of rice. Furthermore, the material cost of the product can be reduced about 20% from that of F-P-4. And thus this vegetable blend is considered to be useful as a low cost supplementary food mixture for growing children.

• The Korean Journal of Physiology
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• v.3 no.2
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• pp.9-16
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• 1969

It is well known that a number of -SH and -SS containing substances afford a certain measure of protection against radiation effects in many biological systems, and it is conceivable that inherent -SH levels in Ehrlich ascites tumour (ELD)cells may be of decisive improtance with respect to the development of cellular radiation injury. So far, little effort has been directed to elucidate the changes in levels of different -SH and -SS groups in ELD cells when the tumour-bearing whole animal was subjected to the sublethal dose of X-irradiation. The present study was designed to bring some lights in the possible changes of and relationship between various sulfhydryl levels, such as P-SH, NP-SH and NP-SS, as well as the content of protein and cell volume of ELD cells, after subjecting the ELD mice to 1,200 r of X-irradiation. The animals used in this experiment were all mixed bred mice of $20{\sim}25\;gm$ in body weight (approximately 2 months old) irrespective of sex. 12 mice in one experiment were inoculated intraperitoneally with 0.2 ml of ascites tumour cells $(2{\times}10^6\;cells)$, and on the 7th day of the tumour growth, they were X-irradiated with 1,200 r, using the conventional X-ray machine under the following conditions: 200 Kv at 15 mA, 0.5 mm Cu filter, target-skin distance: 50 cm. Radiation dose was measured with the the Philip integrating dosimeter. At 24, 36, 48 and 60 hours after the X-irradiation, the mice were killed by cervical dislocation, and the tumours were taken out. Freshly withdrawn ascites tumours were placed in ice, and immediately the cell concentration was measured with the Coulter Cell Counter (Model B), and the hematocrit of the tumour cells were also determined. Cell volume was thus calculated by the cell concentration and hematocrit value. P-SH content of ELD cells was measured potentiometrically according to the method of Calcutt & Doxey, and NP-SH and NP-SS contents were measured spectrophotometrically by the method described by Ellman. Protein content of ELD cells was determined with the Folin phenol reagent by Lowry et al. Altogether, 48 experimental mice were used, and 12 mice with the only exception of X-irradiation were used as the control. Results obtained indicate that the contents of all the cellular sulfhydryl groups as well as cell volume and protein content of the ELD cells increase significantly as time progresses after the sub-lethal X-ray dose of 1,200 r was given and that all the increase is in a lineal fashion. The regression lines of the relative values, (i. e., taking each control value as 1) of all the values obtained, and the regression lines of cell volume, protein and NP-SH are identical, whereas those of NP-SS and P-SH appear to be widely seperated. However, the difference of those two lines (NP-SS & P-SH) were found to be not significant statistically (p>0.05). Therefore, it can be concluded from the above results that all the values examined increase in a lineal fashion with no statistically significant difference among them. Also, with the radiation dose of 1,200 r, the ELD cell becomes enlarged and swollen progressively up to 60 hours post-irradiation and it becomes more than two times of the original normal size at 60 hours after the irradiation, and up to this stage, it seems apparent that the cell division has been slow due to the X-irradiation applied in this experiment. It is well understandable that the contents of NP-SH, NP-SS, P-SH and protein of the ELD cells increase in parallel with the increase of the cell volume by the X-ray does used, but it also seems interesting to note that all the cellular substances tested show no appreciable difference in the pattern of increase.

• Journal of Korea Technology Innovation Society
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• v.20 no.2
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• pp.334-367
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• 2017

The ICT industry has been the main driver of Korea's economy with international competitiveness and is expected to be the growth engine that will revitalize the currently depressed economy. A broad range of different perspectives and opinions on the industry exist in Korea and overseas. Some of these are stereotypes, not all of which are based on objective evidence. Stereotypes refer to widely-held fixed opinions on a specific group and do not necessarily have negative connotations. However, they should not be viewed lightly because they can substantially affect decision-making process. In this regard, this study sought to review the stereotypes of ICT industry and identify objective and relative stereotypes. In the study, a decision-tree analysis was conducted on a survey result of 3,300 small and medium-sized enterprises (SMEs) in order to identify Korean ICT companies' characteristics that distinguish them from other technology companies. The decision-tree analysis, a data mining process based on machine learning, took a total of 291 variables into account in 10 subjects such as: corporate business in general, technology development activities as well as organization and people in technology development. Identifying the variables that distinguish ICT companies from other technology companies with the decision-tree analysis, the study then came up with a list of objective stereotypes of ICT companies. The findings from the stereotypes of Korean ICT companies are as follows. First, the companies are in need of technology policies that help R&D planning and market penetration. Second, policies must better support the companies working to sell new products or explore new business. Third, the companies need policies that support secure protection of development outcomes and proper management of IP rights. Fourth, the administrative procedures related to governmental support for ICT companies' R&D projects must be simplified. It is hoped that the outcome of this study will provide meaningful guidance in establishment, implementation and evaluation of technology policies for ICT SMEs, particularly to policymakers or researchers in relevant government agencies who determine R&D policies for ICT SMEs.