• Journal of Energy Engineering
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• v.18 no.4
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• pp.230-238
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• 2009

We study about small gas engine and fuel cell CHP (Combined Heat and Power) as the technologies for energy conservation and $CO_2$ emissions reduction. Korea government plans to use them in near future. This study quantitatively analyzed energy consumption and $CO_2$ emissions reduction potential of small CHP instead of existing electric power plant (coal steam, combined cycle and oil steam) using LEAP (Long-range Energy Alternative Planning system) as energy-economic model. Three future scenarios are discussed. In every scenario similar condition for each CHP is used. Alternative scenario I: about 6.34% reduction in $CO_2$ emissions is observed in 2019 due to increase in amount of gas engine CHP and fuel cell CHP while coal use in thermoelectric power plant is almost stagnant. In alternative scenario II: a small 0.8% increase in $CO_2$ emission is observed in 2019 keeping conditions similar to alternative scenario I but using natural gas in combined cycle power plant instead of coal. During alternative scenario II overall $CO_2$ emission reduction is observed in 2019 due to added heat production from CHP. Alternative scenario III: about 0.8% reduction in $CO_2$ emissions is observed in 2019 using similar CHP as AS I and AS II. Here coal and oil are used in thermoelectric power plant but the quantity of oil and coal is almost constant for next decade.

• Journal of fish pathology
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• v.28 no.1
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• pp.27-35
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• 2015

VHSV is a major viral agent that affects freshwater and marine fish, causing serious economic losses in aquaculture in the world. Due to their filter-feeding activity, bivalve mollusks may act as viral transmitters after accumulation of the fish viruses released into seawater from infected fish. Amplification by RT-PCR was carried out to investigate the presence of VHSV in pacific oysters (Crassotrea gigas) and blue mussels (Mytilus edulis), inhabiting regions around aquatic farms in Korea. Primers designed from conserved regions of VHSVs allowed us to detect four different types of VHSV in a single PCR. Twenty two of the eighty four samples showed positive results of VHSV in a 2-step RT-PCR. Using six positive samples from three different regions in Korea, we cloned and sequenced the glycoprotein (G) gene (467-bp long) of VHSVs. Genetic analysis of the VHSVs detected in shellfish in various geographical areas of Korea showed highly restricted results to VHSV type Iva. This was in agreement with the reports showing only a single genotype of VHSV (Iva genotype) in outbreaks in cultured or wild fish in Korea. Consequently, we investigated VHSVs carried by bivalve mollusks inhabiting the vicinity of aquatic farms, and revealed correlationship between the type of viral accumulated in shellfish by filter-feeding, and those detected in disease outbreaks in fish.

• Korean Journal of Construction Engineering and Management
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• v.8 no.2
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• pp.146-154
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• 2007

The u-City construction project has become a hot topic In the construction market because it seems economic value-added field for construction firms. However, construction firms don't willingly participate in the u-City construction market because the future business environments for the u-City are very uncertain. Scenario planning is a very powerful method in managing this complex planning situation and is based on scenarios that help each enterprise appropriately adapt itself to its own business environments. Therefore it Is based on the main principles of systems thinking and multiple futures. For the purpose of dealing with such uncertainties, this paper attempts to develop the possible market scenarios of the u-City construction market through a scenario planning approach. From this perspective, we considered various aspects of the u-City construction such as market demands, technology development, policy level and management environment. After considering the relevant issues, we identified the main trends and key uncertainties. Then, we developed three coherent u-City construction market scenarios. On the basis of the proposed scenarios, the business strategies of potential construction firms in the u-City construction market has been formulated. Therefore, construction firms can use these scenarios as a basic data for market analysis and business strategy. Therefore, this paper is able to enhance the participation of construction firms in the u-City construction market.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.368-373
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• 2010

The incisors function as instruments for biting and cutting food during mastication. They also support the lips and face and maintain vertical dimension. In addition, they contribute to overall normal arch appearance. They play important role during the articulation of speech and assist in guiding jaw closure. Extraction and space maintenance are the most common treatment for a tooth with poor prognosis. However, in the mixed dentition, extraction of the upper permanent incisors results in many complications, such as resorption of alveolar bone, poor esthetics, pronunciation, and mastication. Considering these various roles of incisors in oral cavity, approach for traumatized incisors, even the ones with poor prognosis, should be considered first prior to simple extraction. The dentist must take into account the age of the patient, growth potential, occlusion, oral hygiene status, economic status and motivation towards dental health in addition to patient compliance. In this case, although the prognosis was predicted to be unfavorable due to short root and mobility, we could save the central incisor using conservative treatment, reposition by orthodontic appliance instead of extraction.

• Clinical and Experimental Reproductive Medicine
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• v.1 no.1
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• pp.1-14
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• 1974

Data from this study support the View that the following factors are not sufficiently important in Korea to invalidate the relationships observed between age of marriage and fertility: (1) Premarital pregnancy and common law marriage, (2) shortening of birth intervals in late marriages, (3) adverse effects of very eary marriage in reproductive capacity, and (4) postponement of first pregnancy among early marriages. Thirteen variables which were considered to be potential predictors of fertility were studied to determine their influence on three indices of fertility. Age of marriage and family planning praetice are the strongest predictors and account for about 10% and 7% of the total variance, respectively. Seven other factors each account for an intermediate amount of variability; these are ideal number of children, rural versus urban study area, education, aspiration for daughter, index of exposure to mass media, economic index of respondent's home at survey, and residence before marriage. The remaining variables have no consistently significant relationship to fertility. Most of the relationships appear to be stable and consistent over time; others appear to be changing. The latter group include those variables which are associated with modernization indices of family planning practice, mass media exposure. and aspiration for daughters. Thus, the index of family planning practice is of limited significance for the $40{\sim}49$ age group but is the most important variable for the $20{\sim}29$ year women. The relationship is a direct one for the two age groups between 30 and 49 years which suggests that these groups already had high fertility when family planning services became available and that this high fertility then became an inducement to acccept contraception. The pattern of relationship is not yet clear for the $20{\sim}29$ year group. Similar interactions are observed for the other indices of modernity and are discussed. The thirteen variables together can account for a maximum of about 40% of the variance in the number of live births in the age group $30{\sim}39$, and for lesser amounts of variance in other age and fertility groupings.

• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.177-188
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• 2001

Mastitis is one of the most significant cause of economic loss to the dairy industry. Especially, Staphylococcus aureus is a major contagious mastitis-causing pathogen in dairy cattle. Because of its high transmission rate and resistance to antibiotic therapy, staphylococcal mastitis presents a constant threat to the dairy industry. Staphylococcal enterotoxin C(SEC) produced by S aureus has been known as one of superantigens which are able to stimulate a large proportion of T lymphocytes independently of their antigenic specificity. In this experiment, we have conducted preliminary studies with mice and lactating cows to evaluate the immunogenicity and safety of the experimental vaccine consists of SEC mutant antigen on controlling the bovine mastitis associated with S aureus infections. The average value of somatic cell counts in quarter milk, isolation rate of S aureus were consistently decreased in SEC-SER vaccinated groups, whereas antibody titers were highly increased in SEC-SER vaccinated groups. Peripheral blood were also collected from the lactating cows to determine the proportion of leukocyte subpopulation associated with humoral immunity(HI) and cell mediated immunity(CMI). Proportion of leukocyte subpopulation expressing $BoCD2^+$(total T lymphocyte), $BoCD4^+$(T helper cell), $BoCD8^+$(T cytotoxic/suppressor cell) and NonT/NonB lymphocyte which are involved in CMI in SEC-SER vaccinated groups were decreased for the initial stage after first vaccination and then increased from ten weeks after first vaccination maintaining elevated level till 14 weeks after vaccination. In contrast, proportion of monocyte, MHC class II and B lymphocyte which are associated with the production of primary immune response in SEC-SER vaccinated groups were increased for the initial period and then decreased from ten weeks after first vaccination. We present evidence that vaccination of SEC-SER mutant antigen in lactating cows induced a significant proliferation of bovine T lymphocytes. These results suggest that SEC-SER mutant antigen used in this experiment might be one of potential immunogen in developing innovative vaccine against bovine IMI associated with S aureus. Additional challenge trials should be carried out to evaluate substantial protection against S aureus under the commercial farm conditions.

• Journal of Korea Technology Innovation Society
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• v.14 no.spc
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• pp.1128-1151
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• 2011

With the rapid change in technology, it is important to create business opportunities from technology. Many leading companies have tried to improve their competence from capturing those opportunities, which is called TOD (Technology Opportunity Discovery) activities in this research, by identifying emerging technologies or assessing economic and market potential of technologies. Academics have also been interested in the TOD activities but most of the previous studies have focused on developing methodologies or guidelines for TOD. Little effort was given to understanding the current status of TOD activities, which is indispensible to develop effective methodologies for TOD. Therefore, this study aims to investigate the current states of TOD activities, particularly focusing on SMEs, which are the main actors of national innovation system. For the purpose of investigation, firstly, TOD process was defined, and then, based on the process, three main activities of TOD, which include identifying the motivation of TOD, collecting information for TOD, and analyzing the collected information activities for TOD, were examined using a survey method. Finally, the analysis results were used to understand the SMEs' needs and difficulties on TOD activities. Research findings are expected to provide useful information for the future studies on TOD and also can be used to develop a policy for SMEs.

• Journal of Ginseng Research
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• v.42 no.4
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• pp.485-495
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• 2018

Background: The geographical origin of Panax ginseng Meyer, a valuable medicinal plant, is important to both ginseng producers and consumers in the context of economic profit and human health benefits. We, therefore, aimed to discriminate between the cultivation regions of ginseng using the stable isotope ratios of C, N, O, and S, which are abundant bioelements in living organisms. Methods: Six Korean ginseng cultivars (3-yr-old roots) were collected from five different regions in Korea. The C, N, O, and S stable isotope ratios in ginseng roots were measured by isotope ratio mass spectrometry, and then these isotope ratio profiles were statistically analyzed using chemometrics. Results: The various isotope ratios found in P. ginseng roots were significantly influenced by region, cultivar, and the interactions between these two factors ($p{\leq}0.001$). The variation in ${\delta}^{15}N$ and ${\delta}^{13}C$ in ginseng roots was significant for discriminating between different ginseng cultivation regions, and ${\delta}^{18}O$ and ${\delta}^{34}S$ were also affected by both altitude and proximity to coastal areas. Chemometric model results tested in this study provided discrimination between the majority of different cultivation regions. Based on the external validation, this chemometric model also showed good model performance ($R^2=0.853$ and $Q^2=0.738$). Conclusion: Our case study elucidates the variation of C, N, O, and S stable isotope ratios in ginseng root depending on cultivation region. Hence, the analysis of stable isotope ratios is a suitable tool for discrimination between the regional origins of ginseng samples from Korea, with potential application to other countries.

• The Korean Journal of Rehabilitation Nursing
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• v.4 no.1
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• pp.46-57
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• 2001

This study was done to investigate of instrumental activities of daily living(IADL) and quality of life and their relationships between the elderly. Data were collected from 150 elderly home residents. The data were collected from December 1st to December 20th, 2000. Structured questionnaires developed by Lawton & Brody and by Ro were adopted to measure IADL and Quality of life. Data were analyzed for percentage, means, t-test, ANOVA and Parson correlation coefficients using the SPSS program. The results were as follows: 1. The average score of the level of IADL was $20.68{\pm}2.98$ ($M{\pm}SD$) with a range of 7-26. 2. The average score of the level of Quality of life was 2. $96{\pm}0.25$ ($M{\pm}SD$). In the average score of each lower area, highest score was 3.22 for neighbor relationship and family relationship and then 3.00 for self-esteem, 2.95 for economic status, 2.86 for emotional status, and 2.85, lowest score, for physical condition and function. 3. Comparing IADL and Quality of life with general characteristics, IADL showed that there were significant difference in age(t=2.927, p=0.036) and separated children contact frequency(t=2.482, p=0.046), while Quality of life showed that there were significant difference in spouse existence(t=2.334, p=0.021), religion(t=4.089, p=0.008), family style(t=3.285, p=0.040), children number living together(t=5.332, p=0.006), communication with separated children frequency(t=4.129, p=0.003), and separated children contact frequency(t=3.908, p=0.005). 4. There was also significant positive correlation between IADL and Quality of life. The above results show that neighbor relationship and family relationship which have greatly an influence on IADL and Quality of life are very important. The elderly should be helped to satisfy their basic desire and show their potential living together with the younger generation interdependently without being isolated from family and society. Therefore, the nursing strategy that enhance IADL and Quality of life are needed and the nursing strategy that can improve IADL and Quality of life of Elderly Home Residents should be developed.

• Journal of the Korean Geotechnical Society
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• v.32 no.11
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• pp.43-50
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• 2016

A reinforcement is required to ensure the structural safety in case of railway embankment excavation under railway load. A large diameter soil nailing with concrete wall is applied as the reinforcement method instead of the conventional soil nailing system. In this study, a series of 3 dimensional numerical analyses are performed to investigate the optimum reinforcement considering 15 different conditions based on the length, lateral spacing, diameter, and inclination of the reinforcement. The interface between soil nail and perimetric grout is considered by means of cohesion, stiffness and perimeter of the grout. 0.3 m of reinforcement diameter is assessed as the most appropriate based on the economical viewpoint though ground displacement decreases with the increase of diameter, however the difference of displacement is negligible between 0.4 m and 0.3 m of diameter. Surface settlement, lateral displacement of wall, and stress of reinforcement are calculated and economic viewpoint to reinforce embankment considered. Consequently, the optimum reinforcement conditions considering those factors are evaluated as 3 m in length, 0.3 m in diameter, 1.5 m in lateral spacing, and 10 degree of inclination angle in the case of 3 m of excavation depth. Additionally, inclined potential failure surface occurs with approximately 60 degrees from the end of nails and the surface settlement and wall lateral displacement are restrained successfully by the large diameter soil nailing, based on the result of shear strain rate.