• Agribusiness and Information Management
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• v.3 no.2
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• pp.33-42
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• 2011

Although the diffusion of mobile services appears to be occurring much more rapidly than the spread of wired services, there are risks of a new type of digital divide: the mobile divide. The mobile divide, which refers to a specific digital divide that involves the unbalanced diffusion of mobile technologies, must be concretely studied. Thus, this study focuses on the mobile divide with respect to disadvantaged populations. Although various studies suggest that the diffusion of mobile devices may reduce the digital divide, somestudies argue against the positive effect of mobile devices in addressing traditional digital devices. Low and O'Connell (2006) insisted that equity of access to mobile technologies should be considered in the contextof the traditional digital divide; they argued that there may be socio-economic barriers to accessing mobile devices and the mobile Internet that are similar to the socio-economic barriers to accessing stationary computers and the stationary use of the Internet. Focusing on the smartphone divide, this study suggests that emphasizing utilization is an appropriate manner in which to bridge the mobile divide rather than focusing on other factors, such as accessibility and capability, thatprevious studies have used to measure the traditional digital divide.

• Journal of Korean Society of Rural Planning
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• v.13 no.4
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• pp.9-22
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• 2007

With the establishment of municipalities, public interest in small towns in Korea has been on the rise. To initiate an effective study and suggest subsequent policies for small towns, it is necessary to analyze and discuss substantive issues based on specific conditions of these small towns. The primary objective of this paper is to categorize small towns into types and to analyze the peculiarities and differences of their internal factors. The focus of this research is to determine the general characteristics of the classified towns and to suggest specific revitalization and specialized studies about them. In the main analysis of this paper, 39 small towns are divided into sets according to urban rank, conditions of location, and size of the population in the central site. Furthermore, distinctions of the divided towns are analyzed using three constituents for urban organization, including populations, activities, and facilities/land. From the research results, it was determined that there is a difference between small town types, according to population, land cost, and urban activities, based upon the urban rank and size of the population in the central site. Therefore, this paper concludes it is necessary to conduct further studies on time series analysis regarding the peculiarity changes of the types, and to complement the variables for future related studies.

• Journal of Animal Science and Technology
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• v.64 no.5
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• pp.830-841
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• 2022

Genetic analysis has great potential as a tool to differentiate between different species and breeds of livestock. In this study, the optimal combinations of single nucleotide polymorphism (SNP) markers for discriminating the Yeonsan Ogye chicken (Gallus gallus domesticus) breed were identified using high-density 600K SNP array data. In 3,904 individuals from 198 chicken breeds, SNP markers specific to the target population were discovered through a case-control genome-wide association study (GWAS) and filtered out based on the linkage disequilibrium blocks. Significant SNP markers were selected by feature selection applying two machine learning algorithms: Random Forest (RF) and AdaBoost (AB). Using a machine learning approach, the 38 (RF) and 43 (AB) optimal SNP marker combinations for the Yeonsan Ogye chicken population demonstrated 100% accuracy. Hence, the GWAS and machine learning models used in this study can be efficiently utilized to identify the optimal combination of markers for discriminating target populations using multiple SNP markers.

• Research in Plant Disease
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• v.21 no.4
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• pp.255-260
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• 2015

We investigated influence of three commercial antibiotics viz., oxolinic acid, streptomycin, and validamycin A, on biocontrol and plant growth promoting activities of Bacillus vallismortis EXTN-1 and BS07M in Chinese cabbage. Plants were pre-drenched with these strains followed by antibiotics application at recommended and ten-fold diluted concentration to test the effect on biocontrol ability against soft rot caused by Pectobacterium carotovorum SCC1. The viability of the two biocontrol strains and bacterial pathogen SCC1 was significantly reduced by oxolinic acid and streptomycin in vitro assay, but not by validamycin A. In plant trials, strains EXTN-1 and BS07M controlled soft rot in Chinese cabbage, and there was a significant difference in disease severity when the antibiotics were applied to the plants drenched with the two biocontrol agents. Additional foliar applications of oxolinic acid and streptomycin reduced the disease irrespective of pre-drench treatment of the PGPRs. However, when the plants were pre-drenched with EXTN-1 followed by spray of validamycin A at recommended concentration, soft rot significantly reduced compared to untreated control. Similarly, strains EXTN-1 and BS07M significantly enhanced plant growth, but it did not show synergistic effect with additional spray of antibiotics. Populations of the EXTN-1 or BS07M in the rhizosphere of plants sprayed with antibiotics were significantly affected as compared to control. Taken together, our results suggest that the three antibiotics used for soft rot control in Chinese cabbage could affect bacterial mediated biocontrol and plant growth promoting activities. Therefore, combined treatment of the PGPRs and the commercial antibiotics should be carefully applied to sustain environmental friendly disease management.

• Korean Journal of Veterinary Research
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• v.11 no.2
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• pp.163-170
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• 1971

Since the report in 1946 on the first isolation of Japanese encephalitis virus in Korea, the disease is known to occur every year and has occasionally spread in epidemic proportion among human populations. Because of its public health importance, it was deemed highly desirable to gain specific information as to natural history of the disease in Korea if we are to accomplish our ultimate objective of controling the disease in Korea. There still remain, however, unknown factors as to the ecology of Japanese encephalitis virus in Korea. This paper presents the results of serologic study on Korean cattle, hog and horse by means of hemagglutination inhibition (H.I.) test. The serum specimens were collected from Korean cattle, hog and horse their estimated ages being 3 to 9 years, 6 to 24 months and 2 to 14 years respectively, by jugular puncture; in Seoul and Kyung-Ki are a from the first part of May to November last, 1968. The strain used was designated by M 5/596. The methods of H.I. test employed in this study were essentially simillar to those employed by Clark and Fred. The results obtained summarized as follows; 1. Of samples of cattle sera tested, 183 (98%) was found to be positive, H.I. antibodies showing the highest proportion, on September. The lowest proportion showed 81 (68%) of 117 samples, on June. 2. One hundred and ninety-five and 114 swine serum samples tested were all of positive in both on September and October respectively. The lowest proportion showed 92 (29%) of 314 on June too. 3. Ninety (99%) of 91 equine serum samples tested contained demonstrable H.I. antibodies the highest proportion, on August. The lowest proportion was 19 (27%) of 70 samples on June. 4. Implications of these findings in the ecology of Japanese encephalitis Seoul and Kyung-Ki area were discussed.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.4
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• pp.235-245
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• 1979

The land utilization of Korea composed about 22.7% of arable land, 66.9% of forest land and 10.4% for the rest like a house site, road, and lake etc. The ratio of arable land is too small as compared with forest land which is occuping two-thirds of Korea. The expansion of arable land by the reclamation will solve the food problems for increasing populations. First, we have to know the exact extents and distribution of reclaimable land but the reported total extent of reclaimable land in Korea is variable according to the authority which carried out the soil survey. The different reported data of reclaimable land is owing to the method and criteria of soil survey. 840,522ha in Land Capability Survey of the Farm Land Improvement Association and 321,203ha in the Forest Land Survey by the Office of Forest was reported but the Office of Rural Development said that total reclaimable land was 1,400,540ha including grazing and fruit land. To assume the extent of reclaimable land, the soil survey method and criteria of soil survey should be considered. It can be considered that the main reasons of less in extent of reclaimable land in the other authorities than the Office of Rural Development is due to the following. The grazing land and the fruits land are not included by the Farm Land Improvement Association and only relative forest is considered by the Office of Forest. The main purpose of soil survey carried out by the Office of Rural Development is to utilize land of Korea at most. The soil characteristics and potential productivity are considered in soil survey and the reported data was based on reconnaissance soil survey. The more accurate data will be find out by the end of 1979 when the detailed soil survey will be done. In selection of cropping system and management, the soil condition should be considered, because the soil characteristics of reslaimed land is less fertile than the arable lands.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.31-31
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• 2017

Understanding the mechanism(s) to overcome or prevent seed ageing deterioration during storage is of fundamental interest to seed physiologists. Vitamin E (tocols) is known as a key metabolite to efficiently scavenge lipid peroxy radicals which cause membrane breakdown resulting in seed ageing. However, in rice research this hypothesis has been tested for very few lines only without considering intraspecific variation in genomic structure. Here, we present a correlation study between tocols and seed longevity using a diverse rice panel. Seeds of 20 rice accessions held in the International Rice Genebank at the International Rice Research Institute, representing aus, indica, temperate japonica and tropical japonica subpopulations, were used for tocols analysis (quantification of ${\alpha}$-, ${\beta}$-, ${\gamma}$-, ${\delta}$-tocopherol/tocotrienol by ultra performance liquid chromatography) and storage experiments at $45^{\circ}C$ and 10.9% seed moisture content (sample taken for germination testing every 3 days up to 60 days). To examine interactions between DNA sequences and phenotype, the 700k high-density single-nucleotide polymorphism marker data-set was utilized. Both seed longevity (time for viability to fall to 50%; $p_{50}$) and tocols content varied across subpopulations due to heterogeneity in the genetic architecture. Among eight types of tocol homologues, ${\alpha}$-tocopherol and ${\gamma}$-tocotrienol were significantly correlated with $p_{50}$ (negatively and positively, respectively). While temperate japonica varieties were most abundant in ${\alpha}$-tocopherol, indica varieties recorded 1.3 to 1.7-fold higher ${\gamma}$-tocotrienol than those of other subpopulations. It was highlighted that specific ratio of tocol homologues rather than total tocols content plays an important role in the seed longevity mechanism.

• Food Science of Animal Resources
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• v.31 no.6
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• pp.893-898
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• 2011

Milk contains a number of nutrients required for human growth and development, such as disaccharide lactose which is significantly contained in milk and dairy products. About two thirds of world populations are reportedly suffering from lactose intolerance after drinking milk. Lactose intolerance is defined as a maldigestion of lactose in the human intestine with typical symptoms of abdominal pains, bloating, and diarrhea. In this study, incidence of lactose intolerance has been investigated for the elementary school children for 1 year from July, 2010 to June, 2011. It is found that about 70% of the total elementary students have joined the school milk program. Out of 636 total students that participated in this study, 449 were from the metropolis, 85 from middle-sized city, and 102 from the small town including rural areas (small town/rural areas). For distributions of lactose intolerance, 154 students (24.2%) were found to be positive among the total 636 subjects. Based on the size of the city, the symptoms were the most prevalent for the students in the small town/rural areas at 31.4% (32/102), followed by 30.6% (26/85) in middle-sized city, and 21.4% (96/449) in the metropolis. On the other hand, gender had no significant effect on the incidence of lactose intolerance, shown those for boys and girls were 24.8% (77/310), 23.6% (77/326), respectively. Further research is needed to confirm the correct incidence of lactose intolerance symptoms as the frequency is significantly affected by subject's digestive functions including irritable bowel syndrome.

• Journal of Families and Better Life
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• v.9 no.1 s.17
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• pp.81-94
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• 1991

The Purpose of this study is to determine how Korean and United Sates families manage resourcese. Further, socioeconomic and social psychological determinants of frequency of family resoures management will be investigated for each country. Comparision of results well be made to find similarities and differences between Korea and the U.S. Most studies of family resource management have used urban samples, so this study adds to understanding of another segment of the populations. Family resource management variables, as dependent variables, were measured by asking respondents how often they used a variety of wasys to handle finances and time. Independent variables were : (a) total household income, (b) respondents education, (c) respondents ages, (d) householder size, (e) family adaptability, (f) family cohesion, and (g) interpersonal communications. Data for the Korean sample were collected in rural areas of South Korea during summer 1989, U.S. data were collected in two counties of Illinois. The data used in this study include 473 Korean samples and 301 U.S. families. In both samples, the respondent was the financial manager, the person who usually handled the finances and paid the bills. The data were analyzed by frequencys, t-test, and multiple regression analysis methods. As a results, U.S. respondents tended to engage in family resource management more frequently than Korean respondents. This could be attributed to a longer history of consumer education and financial management education taught in the public schools and through the Cooperative Extension Service in the U.S. Social-psycological variables were significant predictors of frequency of family financial management in both samples. the differences in both samples are that, in Korea, frequency of family financial management increased as household size and educational years increased, however, in the United States, the relationships of these variables were not significant. Some similarities and differences were found in Korea and the U.S. families, and this results represents that interpersonal communications are important determinants, even in different cultures. One hadn, the difference of socio-cultural factors result as the difference of some statisical differences. Findings from this study have important implications for research and education, and can be applicated to study of family resource management in other rural areas.

• The Plant Pathology Journal
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• v.27 no.2
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• pp.148-155
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• 2011

Our previous sequence and phylogenetic analyses of the Korean Rice stripe virus (RSV) suggested possible genetic reassortment of RNA segments, but whether this RNA variation contributed to the recent RSV outbreaks in Korea is yet unclear. To further clarify these RSV-RNA segment variations, we developed a reverse transcription-polymerase reaction/restriction enzyme (RT-PCR/RE) analysis-based method. We identified five REs, including DraI, EcoR1, NdeI/AseI, and SpeI, that could differentiate RSV RNA 1-4 subtypes, respectively. Our RT-PCR/RE results provided a clear pattern of RNA reassortment, i.e., different groups of isolates having their RNA segments derived from two to three different RSV ancestors, such as from Eastern and Southwestern Chinese or Japanese M and T isolates. We also found that the migratory small brown planthopper from Eastern China caught by aerial net traps that possesses RSV-RNA3 genotypes corresponds mainly to Eastern China, with a few for Southwestern China based on RT-PCR/RE, sequence and phylogenetic analyses, indicating that RSV populations in Eastern China may also have strong RNA variation. The development of an RE analysisbased method proved a useful epidemiological tool for rapid genotyping and identification of mixed infections by RSV strain and by different subtype.