• Food Science of Animal Resources
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• v.30 no.6
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• pp.975-988
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• 2010

Two experiments were conducted to determine whether water extracts from Artemisia capillaries (A. capillaries) and Camellia sinensis (C. sinensis) could be used as alternatives to antibiotic growth promoters in broiler feed. The experiment 1 was verified their chemical composition, extracts yields, total phenolic compounds concentration, antioxidant activity, antimicrobial activity, and chicken splenocytes proliferation through in vitro test. The extract yields of A. capillaries and C. sinensis were 26.5 and 16.8%, respectively. Total phenolic compounds concentrations of them expressed as gallic acid equivalent were 15.28 and 26.74 mg/mL, respectively. Electron donating abilities of them expressed as $SC_{50}$ showing 50% DPPH radical scavenging were 0.30 and 0.06 mg, respectively. Bacterial inhibitory rates of them against Escherichia coli, Staphylococcus aureus, and Salmonella Typhimurium were ranged from 42.1 to 52.3% and from 21.6 to 33.7%, respectively. And, these extracts increased proliferation of chicken splenocytes. Especially, A. capillaris was more excellent than Echinacea and Concanavalin A known as T-cell stimulator. The experiment 2 was investigated their effects on growth performance, relative organ weight, cecal microflora, blood biochemical parameters, and splenic cytokines mRNA expression in broiler chicks. Four hundred eighty 1-day-old male broiler chicks (Ross 308) were divided in to 4 treatment groups with 4 replicates of 30 birds in each group: NC (control, no antibiotics), PC (avilamycin, 10 ppm; salinomycin, 60 ppm), AC (A. capillaries, 100 ppm), and CS (C. sinensis, 100 ppm); treatments were administered through water supplementation. Final body weight was significantly higher in all treated groups than in NC (p<0.05). Cecal Salmonella numbers were significantly or somewhat decreased in all treated groups than in NC (p<0.05). The relative weights and lengths of the small intestine were more significantly decreased in the PC and AC groups than in the other groups. Cecal Salmonella numbers were significantly or somewhat decreased in all treated groups than in the NC group (p<0.05). The contents of total cholesterol, aspatate aminotransferase, and alanine aminotransferase in blood serum were more significantly decreased in all treated groups than in NC (p<0.05). In conclusion, these results suggested the possibility that these extracts could serve as alternatives for antibiotic growth promoters.

• Journal of Intelligence and Information Systems
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• v.16 no.4
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• pp.85-97
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• 2010

Internet communities are a typical space for knowledge creation and use on the Internet as people discuss their common interests within the internet communities. When we define 'Knowledge Communities' as internet communities that are related to knowledge creation and use, they are categorized into 4 different types such as 'Search Engine,' 'Open Communities,' 'Specialty Communities,' and 'Activity Communities.' Each type of knowledge community does not remain the same, for example. Rather, it changes with time and is also affected by the external business environment. Therefore, it is critical to develop processes for practical use of such changeable knowledge communities. Yet there is little research regarding a strategic framework for knowledge communities as a source of knowledge creation and use. The purposes of this study are (1) to find factors that can affect knowledge creation and use for each type of knowledge community and (2) to develop a strategic framework for practical use of the knowledge communities. Based on previous research, we found 7 factors that have considerable impacts on knowledge creation and use. They were 'Fitness,' 'Reliability,' 'Systemicity,' 'Richness,' 'Similarity,' 'Feedback,' and 'Understanding.' We created 30 different questions from each type of knowledge community. The questions included common sense, IT, business and hobbies, and were uniformly selected from various knowledge communities. Instead of using survey, we used these questions to ask users of the 4 representative web sites such as Google from Search Engine, NAVER Knowledge iN from Open Communities, SLRClub from Specialty Communities, and Wikipedia from Activity Communities. These 4 representative web sites were selected based on popularity (i.e., the 4 most popular sites in Korea). They were also among the 4 most frequently mentioned sitesin previous research. The answers of the 30 knowledge questions were collected and evaluated by the 11 IT experts who have been working for IT companies more than 3 years. When evaluating, the 11 experts used the above 7 knowledge factors as criteria. Using a stepwise linear regression for the evaluation of the 7 knowledge factors, we found that each factors affects differently knowledge creation and use for each type of knowledge community. The results of the stepwise linear regression analysis showed the relationship between 'Understanding' and other knowledge factors. The relationship was different regarding the type of knowledge community. The results indicated that 'Understanding' was significantly related to 'Reliability' at 'Search Engine type', to 'Fitness' at 'Open Community type', to 'Reliability' and 'Similarity' at 'Specialty Community type', and to 'Richness' and 'Similarity' at 'Activity Community type'. A strategic framework was created from the results of this study and such framework can be useful for knowledge communities that are not stable with time. For the success of knowledge community, the results of this study suggest that it is essential to ensure there are factors that can influence knowledge communities. It is also vital to reinforce each factor has its unique influence on related knowledge community. Thus, these changeable knowledge communities should be transformed into an adequate type with proper business strategies and objectives. They also should be progressed into a type that covers varioustypes of knowledge communities. For example, DCInside started from a small specialty community focusing on digital camera hardware and camerawork and then was transformed to an open community focusing on social issues through well-known photo galleries. NAVER started from a typical search engine and now covers an open community and a special community through additional web services such as NAVER knowledge iN, NAVER Cafe, and NAVER Blog. NAVER is currently competing withan activity community such as Wikipedia through the NAVER encyclopedia that provides similar services with NAVER encyclopedia's users as Wikipedia does. Finally, the results of this study provide meaningfully practical guidance for practitioners in that which type of knowledge community is most appropriate to the fluctuated business environment as knowledge community itself evolves with time.

• Korean small business review
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• v.31 no.2
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• pp.103-120
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• 2009

As business incubation centers (BICs) have been operating for more than 10 years in Korea, many early stage startups tend to use the services provided by the incubating centers. BICs in Korea have accumulated the knowledge and experience in the past ten years and their services have been considerably improved. The business incubating service has three facets : (1) business infrastructure service, (2) direct service, and (3) indirect service. The mission of BICs is to provide the early stage entrepreneurs with the incubating service in a limited period time to help them grow strong enough to survive the fierce competition after graduating from the incubation. However, the incubating services sometimes fail to foster the independence of new startup companies, and raise the dependence of many companies on BICs. Thus, the dependence on BICs is a very important factor to understand the survival of the incubated startup companies after graduation from BICs. The purpose of this study is to identify the main factors that influence the firm's dependence on BICs and to characterize the relationships among the identified factors. The business incubating service is a core construct of this study. It includes various activities and resources, such as offering the physical facilities, legal service, and connecting them with outside organizations. These services are extensive and take various forms. They are provided by BICs directly or indirectly. Past studies have identified various incubating services and classify them in different ways. Based on the past studies, we classify the business incubating service into three categories as mentioned above : (1) business infrastructure support, (2) direct support, and (3) networking support. The business infrastructure support is to provide the essential resources to start the business, such as physical facilities. The direct support is to offer the business resources available in the BICs, such as human, technical, and administrational resources. Finally, the indirect service was to support the resource in the outside of business incubation center. Dependence is generally defined as the degree to which a client firm needs the resources provided by the service provider in order to achieve its goals. Dependence is generated when a firm recognizes the benefits of interacting with its counterpart. Hence, the more positive outcomes a firm derives from its relationship with the partner, the more dependent on the partner the firm must inevitably become. In business incubating, as a resident firm is incubated in longer period, we can predict that her dependence on BICs would be stronger. In order to foster the independence of the incubated firms, BICs have to be able to manipulate the provision of their services to control the firms' dependence on BICs. Based on the above discussion, the research model for relationships between dependence and its affecting factors was developed. We surveyed the companies residing in BICs to test our research model. The instrument of our study was modified, in part, on the basis of previous relevant studies. For the purposes of testing reliability and validity, preliminary testing was conducted with firms that were residing in BICs and incubated by the BICs in the region of Gwangju and Jeonnam. The questionnaire was modified in accordance with the pre-test feedback. We mailed to all of the firms that had been incubated by the BICs with the help of business incubating managers of each BIC. The survey was conducted over a three week period. Gifts (of approximately ₩10,000 value) were offered to all actively participating respondents. The incubating period was reported by the business incubating managers, and it was transformed using natural logarithms. A total of 180 firms participated in the survey. However, we excluded 4 cases due to a lack of consistency using reversed items in the answers of the companies, and 176 cases were used for the analysis. We acknowledge that 176 samples may not be sufficient to conduct regression analyses with 5 research variables in our study. Each variable was measured through multiple items. We conducted an exploratory factor analysis to assess their unidimensionality. In an effort to test the construct validity of the instruments, a principal component factor analysis was conducted with Varimax rotation. The items correspond well to each singular factor, demonstrating a high degree of convergent validity. As the factor loadings for a variable (or factor) are higher than the factor loadings for the other variables, the instrument's discriminant validity is shown to be clear. Each factor was extracted as expected, which explained 70.97, 66.321, and 52.97 percent, respectively, of the total variance each with eigen values greater than 1.000. The internal consistency reliability of the variables was evaluated by computing Cronbach's alphas. The Cronbach's alpha values of the variables, which ranged from 0.717 to 0.950, were all securely over 0.700, which is satisfactory. The reliability and validity of the research variables are all, therefore, considered acceptable. The effects of dependence were assessed using a regression analysis. The Pearson correlations were calculated for the variables, measured by interval or ratio scales. Potential multicollinearity among the antecedents was evaluated prior to the multiple regression analysis, as some of the variables were significantly correlated with others (e.g., direct service and indirect service). Although several variables show the evidence of significant correlations, their tolerance values range between 0.334 and 0.613, thereby demonstrating that multicollinearity is not a likely threat to the parameter estimates. Checking some basic assumptions for the regression analyses, we decided to conduct multiple regression analyses and moderated regression analyses to test the given hypotheses. The results of the regression analyses indicate that the regression model is significant at p < 0.001 (F = 44.260), and that the predictors of the research model explain 42.6 percent of the total variance. Hypotheses 1, 2, and 3 address the relationships between the dependence of the incubated firms and the business incubating services. Business infrastructure service, direct service, and indirect service are all significantly related with dependence (β = 0.300, p < 0.001; β = 0.230, p < 0.001; β = 0.226, p < 0.001), thus supporting Hypotheses 1, 2, and 3. When the incubating period is the moderator and dependence is the dependent variable, the addition of the interaction terms with the antecedents to the regression equation yielded a significant increase in R2 (F change = 2.789, p < 0.05). In particular, direct service and indirect service exert different effects on dependence. Hence, the results support Hypotheses 5 and 6. This study provides several strategies and specific calls to action for BICs, based on our empirical findings. Business infrastructure service has more effect on the firm's dependence than the other two services. The introduction of an additional high charge rate for a graduated but allowed to stay in the BIC is a basic and legitimate condition for the BIC to control the firm's dependence. We detected the differential effects of direct and indirect services on the firm's dependence. The firms with long incubating period are more sensitive to indirect service positively, and more sensitive to direct service negatively, when assessing their levels of dependence. This implies that BICs must develop a strategy on the basis of a firm's incubating period. Last but not least, it would be valuable to discover other important variables that influence the firm's dependence in the future studies. Moreover, future studies to explain the independence of startup companies in BICs would also be valuable.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.436-442
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• 2008

Hydroxyproline and Pro-Hyp dipeptide are the digestive products of collagen hydrolysate called collagen peptide. Some suggested that collagen peptides could improve aged or damaged skins, however, the effects of collagen peptides on the skin have not been known. In this study, we investigated the effects of digestive products of collagen peptides, hydroxyproline and Pro-Hyp dipeptide on skin quality using the UV-damaged dorsal skin of hairless mouse as a model system. Female SKH hairless mice were pre-irradiated with UV for 7 weeks, and then hydroxyproline, Pro-Hyp dipeptide were orally administered for 7 weeks with UV irradiation. Wrinkle formation (by replica image), skin elasticity, barrier status (by TEWL, transepidermal water loss), epidermis thickness, and biophysical changes in the stratum comeum (by hematoxylin & eosin staining) were examined. With the oral peptide treatment, effects such as skin barrier maintenance, anti-skin thickening, and recovery of the stratum corneum were observed. These results indicate that oral intake of collagen peptides may have beneficial effects on damaged skin cells.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.3
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• pp.188-201
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• 2005

This is the first part of a two-part paper which describes comparison of reliability design methods by application to Donghae Harbor Breakwaters. This paper, Part 1, is restricted to stability of armor blocks, while Part 2 deals with sliding of caissons. Reliability design methods have been developed fur breakwater designs since the mid-1980s. The reliability design method is classified into three categories depending on the level of probabilistic concepts being employed. In the Level 1 method, partial safety factors are used, which are predetermined depending on the allowable probability of failure. In the Level 2 method, the probability of failure is evaluated with the reliability index, which is calculated using the means and standard deviations of the load and resistance. The load and resistance are assumed to distribute normally. In the Level 3 method, the cumulative quantity of failure (e.g. cumulative damage of armor blocks) during the lifetime of the breakwater is calculated without assumptions of normal distribution of load and resistance. Each method calculates different design parameters, but they can be expressed in terms of probability of failure so that tile difference can be compared among the different methods. In this study, we applied the reliability design methods to the stability of armor blocks of the breakwaters of Donghae Harbor, which was constructed by traditional deterministic design methods to be damaged in 1987. Analyses are made for the breakwaters before the damage and after reinforcement. The probability of failure before the damage is much higher than the target probability of failure while that for the reinforced breakwater is much lower than the target value, indicating that the breakwaters before damage and after reinforcement were under- and over-designed, respectively. On the other hand, the results of the different reliability design methods were in fairly good agreement, confirming that there is not much difference among different methods.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.421-432
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• 2016

In order to find new functional materials for the cosmetics application, we investigated anti-inflammatory and whitening effects of the Protaetia brevitarsis seulensis (P. brevitarsis) extracts, which were prepared by the various oriental conversion methods, as follows; fresh, roasted one time, roasted two times, roasted three times, and steamed. 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of the various solvent extracts (80% ethanol, 50% ethanol, ethyl acetate, hexane) of P. brevitarsis extracts were 85.5, 22.4, 37.0 and 19.4% respectively. The 80% ethanol extract with the highest antioxidant activity was used for all experiments. In case of antioxidant activity test of the extracts, all the extracts showed the activities in concentration dependent manner regardless of the sample preparation methods. Superoxide dismutase-like (SOD-like) activities of the extracts roasted three times and steamed were 62.9 and 55.9%, respectively in $500{\mu}g/mL$. Effects of extracts on the inflammation of RAW 264.7 cell induced by lipopolysaccharide (LPS) showed decreasing tendency of $NO{\cdot}$ and prostaglandin $E_2$ ($PGE_2$) production; PBS fresh (38.0%), PBS roasted one time (41.0%), PBS roasted two times (69.8%), PBS roasted three times (70.1%), PBS steamed (78.5%). Intracellular tyrosinase and melanin biosynthesis inhibitory activities of the extracts were decreased in a concentration dependent manner. However, the fresh P. brevitarsis extracts without the oriental conversion method showed 90.7% decrease compared to the control group treated with ${\alpha}$-MSH alone at $500{\mu}g/mL$. Taken together, these results suggest the oriental conversion method can be applied in development of cosmetic materials in order to improve anti-inflammatory and whitening effects of the cosmetics products.

• The Korean Journal of Pharmacology
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• v.17 no.1 s.28
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• pp.17-25
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• 1981

No evidence has accumulated that lead compound is an essential component for biological function in animals. Lead is absorbed primarily through the epithelial mucosal cells in duodenum and the absorption can be enhanced by the substances which bind lead and increase its solubility. Iron, zinc and calcium ions, however, decrease the absorption of lead without affecting its solubility, probably by competing for shared absorptive receptors in the intestinal mucosa. Therefore, the absorption of lead is increased in iron deficient animals. Lead shows a strong affinity for ligands such as phosphate, cysteinyl and histidyl side chains of proteins, pterins and porphyrins. Hence lead can act on various active sites of enzymes, inhibiting the enzymes which has functional sulfhydryl groups. lead inhibits the activity of ${\delta}$-aminolevulinic acid dehydratase for the biosynthesis of hemoproteins and cytochrome, which catalyzed the synthesis of monopyrrole prophobilinogen from ${\delta}$-aminolevulinic acid. Accordingly lead decrease hepatic cytochrome p-450 content, resulting an inhibition of the activity of demethylase and hydroxylase in liver. Little informations are available on the effect of lead on digestive system although the catastrophic effects of lead intoxication are well documented. The present study was, therefore, attempted to investigate the effect of lead on pancreaticobiliary secretion in rats. Albino rats of both sexes weighing $170{\sim}230g$ were used for this study. The animals were divided into one control and three treated groups, i.e., control (physiologic saline 1.5ml/kg i.p.), lead acetate $(l0{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and EDTA$(each\;10{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and $FeSO_4(each\;l0{\mu}mole/kg/day\;hp)$. The pancreatico-biliary juice was collected under urethane anesthesia, and activities of amylase and lipase were determined by employing Sumner's and Cherry and Crandall's methods. The summarized results are follows. 1) In the experiment for acute toxicity of lead acetate, 20% of mortality was observed in rat treated with lead acetate as well as inhibition of the activity of amylase in the juice at the 3 rd day of the treatment. 2) No increases in body weight were observed in rats treated with lead acetate, while in control group the significant increases were observed. However, the body weights of animals were increased in the group lead acetate plus EDTA or $FeSO_4$. 3) Lead acetate decreased significantly the volume of pancreatico-biliary juice whereas additional treatment of EDTA and $FeSO_4$ prevented it. 4) Total activity of amylase was markedly reduced due to lead acetate treatment, but no change was showed following additional treatment with EDTA and $FeSO_4$. 5) No changes in the cholate and lipase output were observed in rats treated with lead acetate as compared with that of control rats. 6) Increase in bilirubin output in rats treated with lead acetate was shown on the 2nd and 3rd weeks treatment. 7) In the case of in vitro experiment, lead acetate also markedly inhibited release of amylase from pancreatic fragment. 8) Histologic finding indicated that acini vacuolation was induced in the pancreatic tissue of rat treated with lead acete. From the above results, it might be concluded that lead acetate decreases the volume of pancreatico-biliary secretion and inhibits the amylase activity, by acting directly on pancreatic cells.

• Journal of The Korean Association For Science Education
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• v.32 no.1
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• pp.15-29
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• 2012

The purpose of this study was to investigate the educational factors on career choice of science-gifted students to science and technology bound universities and the difference of perception in regards to group factors. In addition, this study aimed to examine the effects of science-gifted education and critical events in relation to career choice to science and technology bound universities. For the study, 104 university freshmen, 75 males and 29 females, were sampled from UNIST (Ulsan National Institute of Science and Technology), that many science high school graduates entered this year. The survey was conducted with questionnaires to do with the perceptions concerning career choice and educational factors that cause them to choose such career directions. The educational factors on career choice to science and technology bound universities were classified as 3 main categories such as educational environment factor (teaching-learning factor), human factor, attitude towards science factor and the subcategories within each category. The research findings are as follows: First, the factors were closely connected with each other and 'the project centered classes' were highly interrelated with other educational environment factors such as 'the experiment activity and environment for the activity' and 'influence of teachers (professors).' Second, the female students and graduates of the science high school were more positively influenced by the educational environment and human factors on their decision for career than male students and graduates of the general high school. Third, this research found that historical scientific knowledge, perception of scientists' social status and job applications in the science field gave less influence rather than other factors on their decision for career. As a result of examining critical events for science-gifted education in relation to career choice to science and technology bound universities, numerous students mentioned that the extracurricular science activities such as science camps and field trips gave significant effects on students' career choices to science and engineering fields.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.4
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• pp.323-328
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• 1998

A field experiment was carried out to determine the effects of chemical and mechanical treatment at mowing on the field drying rate and hay quality of autumn oat (Avena sativa L.). The chemical drying agent/mower conditioner ($K_2CO_3$ 2%, conditioning, $K_2CO_3$ 2% + conditioning and control) were treated at different harvest stages (late boot, heading and bloom stage) for hastening hay manufacture in the autumn of 1996. After field dry, square bales were made by hay baler, and the dry matter(DM) loss and visual estimation of oat hay were evaluated after storing two months. In general, the field drying rate of oat was slow, regardless of harvest stage. Mechanical and chemical + mechanical treatment were effective, but the effectiveness of chemical alone was very low. With mower conditioning, the duration of field dry was shortened by 2 days compared with control. The DM loss of hay was higher at boot stage(51.4%) than at heading stage (21.1%), and the DM loss was reduced by mechanical and chemical + mechanical combined treatment. The visual score (leafiness, green color, odor and softness) of hay after storing was high in mechanical and chemical + mechanical, but the score by chemical alone was very low. The nutritive value (ADF, NDF, digestibility, and relative feed value) of hay was also high with treatment of mechanical and chemical + mechanical, but the quality by chemical alone was similar compared with control. In conclusion, mower conditioning can enhance the field drying rate of autumn oat, but the drying efficiency of the chemical drying agent was very low. However, it is suggested that hay-making of oat in autumn is very hard though using mower conditioner.

• Journal of Animal Science and Technology
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• v.44 no.2
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• pp.181-190
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• 2002

This study was performed to determine sequences of the mt DNA D-loop region, including $tRNA^{Pro}$ and $tRNA^{Pre}$ and to analysis sequence variation polymorphism in Korean cattle. The resulting sequencies were compared with previously published sequences for other cattle breeds(GenBank J01394). The PCR was used to amplify an 1142bp between nucleotides 15061 and 404 within the D-loop region of mt DNA using specific primers. Korean cattle showed 24 polymorphic sites by nucleotide substitutions and insertions of single base pairs. About 50% of polymorphic sites were found in positions 16042 to 16122 with the most variable region. Among these polymorphic sites, variations at 16055, 16230 and 16260 bp were detected as new sequence variants in Korean cattle. These specific polymorphic sites have not been reported in the Japanese black cattle and European cattle. Therefore, mt DNA variants in the D-loop region may be used as genetic markers for specifying Korean cattle. The frequencies of positions 169, 16302, 16093, 16042, 16119 with a high level of sequence polymorphism were 0.81, 0.56, 0.56, 0.50 and 0.43, respectively. In comparison of genetic distances, Korean cattle showed the more closely to European cattle as Bos taurus than Bos indicus such as African and India breeds. In conclusion, these mt DNA sequence polymorphisms in the D-loop region for Korean cattle may be useful for the analysis of cytoplasmic genetic variation and associations with economic important traits and genetic analysis of maternal lineage.