• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.869-877
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• 2008

The purpose of this study is to investigate the trends and patterns of variou kind of water uses in a household by metering in Korea. Water use components are classified by toilet, washbowl, bathing, laundry, kitchen, etc. Flow meters are installed in 146 household selected by sampling in all around Korea. The data are gathered by web-based data collection system from the year 2002 to 2006, considering pre-investigated data such as occupation, revenue, family members, housing types, age, floor area, water saving devices, education, etc. Reliable data are selected by upper fence method for each observed water use component and statistical characteristics are estimated for each residential type to determine liter per capita per day. Estimated domestic per capita day show an indoor water use with the range from $150{\ell}pcd$ to $169{\ell}pcd$ for each housing type as the order of high rise apartment, multi-house, and single house. As the order of consuming amount among water use components, it is investigated that toilet($38.5{\ell}pcd$) is the first, and the second is laundry water($30.8{\ell}pcd$), the third is kitchen($28.4{\ell}pcd$), the fourth is bathtub($24.7{\ell}pcd$), the next is washbowl($15.4{\ell}pcd$). The results are compared with water uses in U.K. and U.S. As life style has been changed into western style, pattern of water use in Korea is tend to be similar with the U.S. water use pattern. Compared with the surveying results by Bradley, on 1985. Thirty liter of total use increased with the advancement of economic level, and a little change of water use pattern can be found. Especially, toilet water take almost half part of total water use and laundry water shows lowest as 11% in surveying at the year of 1985. But, this study shows that 39 liter, 28% of toilet water, has been decreased by the spread of saving devices and campaign. It is supposed that the spread large sized laundry machine make by-hand laundry has been decreased and water use increased. Unit water amount of each end-use in household can be applied to design factor for water and wastewater facilities, and it play a role as information in establishing water demand forecasting and conservation policy.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.325-330
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• 2007

RNase E is an essential Escherichia coli endoribonuclease that plays a major role in the decay and processing of a large fraction of RNAs in the cell and expression of N-terminal domain consisted of 1-498 amino acids (N-Rne) is sufficient to support normal cellular growth. By utilizing these properties of RNase E, we developed a genetic system to screen for amino acid substitutions in the catalytic domain of the protein (N-Rne) that lead to various phenotypes. Using this system, we identified three kinds of mutants. A mutant N-Rne containing amino acid substitution in the S1 domain (I6T) of the protein was not able to support survival of E. coli cells, and another mutant N-Rne with amino acid substitution at the position 488 (R488C) in the small domain enabled N-Rne to have an elevated ribonucleolytic activity, while amino acid substitution in the DNase I domain (N305D) only enabled N-Rne to support survival of E. roli cells when the mutant N-Rne was over-expressed. Analysis of copy number of ColEl-type plasmid revealed that effects of amino acid substitution on the ability of N-Rne to support cellular growth stemmed from their differential effects on the ribonucleolytic activity of N-Rne in the cell. These results imply that the genetic system developed in this study can be used to isolate mutant RNase E with various phenotypes, which would help to unveil a functional role of each subdomain of the protein in the regulation of RNA stability in E. coli.

• Management & Information Systems Review
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• v.36 no.4
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• pp.117-127
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• 2017

In recent times the size of the world IPO in general has skyrocketed. Specifically, China's financial market development is becoming important as both the size of China's capital market and the number of companies going public are gradually increasing. This has led to a rapid development of venture vapital(VC) institutions in China for the past couple of decades. This study focuses on one of the three markets of China's Shenzhen Stock Exchange-the Growth Enterprise Board((GEB) hereafter, ChiNext). The ChiNext is established in October, 2009 to enable hi-tech or high growth potential technology companies that find it relatively difficult to fulfil the listing requirements of either the Shenzhen Main Board or Small and Medium Size Enterprise Board(SMEB) to go public. This study covers a three-year period(2012/01/-2015/01) and analyze first day initial return of 83 venture capital-backed companies and 53 non-venture capital-backed companies using T-test. Regression analysis is used as to examine the variables affecting IPO's first-day return. The empirical results are four-fold. First, the level of first day return of venture-backed is significantly lower than non venture capital backed support in the Chinese venture capital market. Second, the level of first-day return of listed companies supported by foreign venture capital is significantly higher than that of companies receiving domestic venture capital support. Third, the firms that have a large number of venture capital firms showed a low level of first-day return. Fourth, regression result for the IPO first-day return which is as dependent variable indicates that the venture capital support(VCAP), number of venture capital(VCNum), offering size(Lnsize) and PER all affect have negative effect on the first day initial return. Also, the venture capital type(VCType), turnover ratio and the the firm type(Tech-firms) statistically affect IPO first day return positively. Finally, by shedding more light on the IPO first-day return, this paper provides meaningful information to investors about the Chinese IPO market.

• KDI Journal of Economic Policy
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• v.12 no.1
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• pp.127-148
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• 1990

A Milgrom-Roberts style signalling model of limit pricing is developed to analyze the possibility and the scope of limit pricing in general, noncooperative oligopolies. The model contains multiple incumbent firms facing a potential entrant and assumes an information asymmetry between incombents and the potential entrant about the market demand. There are two periods in the model. In period 1, n incumbent firms simultaneously and noncooperatively choose quantities. At the end of period 1, the potential entrant observes the market price and makes an entry decision. In period 2, depending on the entry decision of the entrant, n' or (n+1) firms choose quantities again before the game terminates. Since the choice of incumbent firms in period 1 depends on their information about demand, the market price in period 1 conveys information about the market demand. Thus, there is a systematic link between the market price and the profitability of entry. Using Bayes-Nash equilibrium as the solution concept, we find that there exist some demand conditions under which incumbent firms will limit price. In symmetric equilibria, incumbent firms each produce an output that is greater than the Cournot output and induce a price that is below the Cournot price. In doing so, each incumbent firm refrains from maximizing short-run profit and supplies a public good that is entry deterrence. The reason that entry is deterred by such a reduced price is that it conveys information about the demand of the industry that is unfavorable to the entrant. This establishes the possibility of limit pricing by noncooperative oligopolists in a setting that is fully rational, and also generalizes the result of Milgrom and Roberts to general oligopolies, confirming Bain's intuition. Limit pricing by incumbents explained above can be interpreted as a form of credible collusion in which each firm voluntarily deviates from myopic optimization in order to deter entry using their superior information. This type of implicit collusion differs from Folk-theorem type collusions in many ways and suggests that a collusion can be a credible one even in finite games as long as there is information asymmetry. Another important result is that as the number of incumbent firms approaches infinity, or as the industry approaches a competitive one, the probability that limit pricing occurs converges to zero and the probability of entry converges to that under complete information. This limit result confirms the intuition that as the number of agents sharing the same private information increases, the value of the private information decreases, and the probability that the information gets revealed increases. This limit result also supports the conventional belief that there is no entry problem in a competitive market. Considering the fact that limit pricing is generally believed to occur at an early stage of an industry and the fact that many industries in Korea are oligopolies in their infant stages, the theoretical results of this paper suggest that we should pay attention to the possibility of implicit collusion by incumbent firms aimed at deterring new entry using superior information. The long-term loss to the Korean economy from limit pricing can be very large if the industry in question is a part of the world market and the domestic potential entrant whose entry is deterred could .have developed into a competitor in the world market. In this case, the long-term loss to the Korean economy should include the lost opportunity in the world market in addition to the domestic long-run welfare loss.

• Journal of the Korean Geographical Society
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• v.29 no.1
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• pp.16-38
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• 1994

The spatial structure of Korea has been changed drastically during the second half of this century. The events such as the Korean War and the resultant division of the Korean Peninsular into two Koreas, rapid industrialization and urbanization are the major causes among others for the spatial changes of the nation. The changes in turn have spawned a number of spatial problems. It is time, we argue, to diagnose how much the nation is now ill-structured, and to discuss of which directions the long-term spatial management be reoriented. A delphi survey was conducted during the early 1993 to fulfill such research needs. Questionnaires were distributed among geographers, planners, and high governmental officials throughout the nation. These 'experts of spatial problems' were requested to evaluate the past spatial policies and strategies, and to identify spatial and environmental problems at the national, regional and local levels. The survey included questions with regard to the spatial problems in North Korea too. A complementary literature survey in the fields of spatial sciences was accomplished as well in order to identify the major research interests and issues with regard to the nations's spatial structure. The delphi survey results indicatee that the present spatial structure: in relation to consumption, housing and economic activities is satisfactory in overall, while rather poor in terms of education, leisure and community activities. Most of the experts consider infrastructural improvements are urgent in the areas of roads, waste disposal facilitles, railroads, harbors, water supply and drainage systems. The over-concentration of economic, social and political function in the Seoul Metropolitan Region is perceived to be the most serious spatial problem in Korea. The long-term solutions suggested are strategies toward a more balanced regional development as well as toward a cleaner environment. The concensus among the experts for the short-term solution is the redistribution of population and industries from the Seoul Metropolitan Region to the intermediate and small cities. The land use policies and concurrent large-scale infrastructural projects are evaluated largely pertinent and desirable in general. It is, however, suggested that development projects be conducted in a more harmonious way with environment. The survey respondents suggest that the present environmental management policies should be reexamined critically. With regard to regional and local problems, transportation and pollutions are thought to be most serious in the Seoul Metropolitan Region, while employment opportunities, and information, education and health care services are most deprived in small cities and rural areas. The majority of the experts consider a city size of 250, 000-500, 000 population is desirable to live within. Respondents beileve that North Korea's physical environment is still not aggravated much whereas its infrastructural provisions are largely pool. The co-authors of this research figure a "environmentaly sound and spatially balanced Korean Penninsular" as the ideal type of spatial structure in Korea. The basic guidelines toward this ideal prototype are suggested: the recovery of spetial integrity, progressive restructuring of the nation, land uses geared to public welfare rather than private interests, and eco-humanistic approach in spatial policies.

• Tuberculosis and Respiratory Diseases
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• v.40 no.1
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• pp.23-28
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• 1993

Background: Since an important component of carcinogenesis is unregulated growth, many investigators have reported the methods to detect cell proliferation in tissues including PCNA. PCNA is a 36 Kd intranuclear polypeptide and plays a critical role in cell proliferation. Thus progressive dysregulation of proliferation during carcinogenesis can be directly visualized in the paraffin embedded tissue using immunohistochemistry for PCNA which has an advantage of simplicity and maintenance of tissue architecture. The heterogeneity of PCNA expression is known to be related with proliferating fraction, histologic grade, DNA ploidy, and susceptibility of anticancer drugs, etc. We analyzed the biologic significance of the expression of PCNA in lung cancer tissues. Method: 43 lung cancer tissues, which were resected by surgery and were embedded in paraffin, were stained immunohistochemically by one hour MicroProbe System and the results were corelated with cell type, stage, site and survival. Result: 1) Suamous cell type showed high positivity (89%) than in adenocarcinoma (54%). 2) No significant difference related to tumor stage was noticed. 3) No significant difference between primary site and metastatic site was noticed. 4) No significant difference in 12-month survival between positive group and negative group was noticed. Conclusion: From this study, we concluded that imunohistochemistry for PCNA expression of routinely processed tissue is a simple technique for the assessment of proliferation in non-small cell lung cancer. Whether the labelling index has an independent prognostic value and deserves special attention in pathobiological evaluation in lung cancer remains to be investigated from large series with longer follow-up and to be correlated with multiple biological markers.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.7 no.1
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• pp.5-22
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• 1994

This paper attempts to define some general characteristics of the Abstracting Journals published in Korea as evidenced in those published during last ten years. This purpose is achieved by comparing the results of the two studies conducted by the author in 1984 and in 1994. Both studies were conducted to present the state of the art in the abstracting services in Korea. The major conclusions made in this paper are summarised as follows： (1) Researchers and professionals working in a small number of subject fields are benefited by the abstracting journals, which provide current-awareness services of recent achievements in research and development in Korea. Those in most of the fields have no abstracting journals of their own, and naturally they have no substantial abstract-ing services. Even many researchers and professionals in the fields that have some abstracting journals are not informed of research results in their fields because the abstracting journals are scattered in many narrow subjects and in many cases, the abstracting journals only cover publications in some specific forms and kinds. (2) Abstracting journals that cover more than two subject fields, which are supposed to be of more or less help to the researchers and professionals in the subject fields that have no abstracting journals published in their fields, have rapidly increased in number in the past ten years. Most of suh abstracting journals carry thesis and dissertation abstracts, and the rest, those of research papers published in specific places, in specific forms, by specific institutions, and of reports of research projects sponsored by specific foundations. These abstracting journals are not of the kind that comprehensively provide researchers in related fields with current awareness of publications of research results in Korea. (3) Most of the abstracting Journals existing in Korea are Published by institutions of higher education and research institutes, and the rest, by commercial publishers, industrial firms, libraries, information centres, government agencies, research foundations, learned societies, etc. Those which publish many titles are small in number and those publish one or two titles are large in number. The former is largely made up of institutions of higher education and research institutes. (4) The abstracting journals published in Korea are classified by type into those of dissertations, research papers, journal articles, patent specifications in that descending order. The fact that Master; and doctoral dissertation abstracts ate dominating in Korea is due to the irrational practice of publishing those abstracts at many different institutions. (5) Most of the abstracting journals existing in Korea are published by national or government-supported research institutes in order to publicise their own research outputs. Their coverage of literature is normally narrow, and naturally their value to users is limited. (6) Korean is the desirable language for the abstracting journals intended to be distributed within Korea. About half of the abstracting jornals published in Korea is printed in Korean and the other half, in foreign languages, and in Korean and in foreign languages together. All the abstracting journals in foreign languages are printed in English except one, which is printed in Japanese. (7) Some twenty per cent of the abstracting journals in Korea is published monthly, bimonthly, and quarterly. The others are published annually, biannually and irregularly. The latter may not function properly as a current-awareness tool due to long intervals between their issues. It is particularly undesirable that about half of the abstracting journals in Korea is published irregularly. Most of the abstracting journals published in Korea are distributed freely to individuals and institutions selected by the publishers. (8) The abstracting journals published by the use of computers increased drastically in the past ten years. The abstracting journals produced by the conventional type-setting method will possibly disappear in Korea in another ten years to come. Automation of the production of abstracting journals does not simply mean technical, economic improvement in publishing processes but availability of machine-readable databases that can be used for many other pur-poses, including generation of other bibliographical publications and provision of machine literature searching capabilities. Necessary steps should be taken for this important development immediately.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.11-18
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• 2017

The purpose of this survey was to collect basic data on breeding systems of animal welfare-approved laying hen farms in Korea. Questionnaires were mailed to 64 animal welfare-approved farms, and 20 questionnaires (31.3%) were returned. The housing systems were fabric coverlet (4 farms, representing 20%), naturally farmed (Yamagisi, 7 farms, 35%), and steel panel-framed housing (9 farms, 45%). The 20 farms had stocking densities of $2{\sim}3birds/m^2$ (2 farms; 10%), $4{\sim}5birds/m^2$ (10 farms; 50%), and $6{\sim}7birds/m^2$ (8 farms; 40%). Breeding methods were floor-housed (14 farms; 70%), free-range (3 farms; 15%), and floor plus free-range (3 farms; 15%). Stocking density was $4{\sim}6birds/m^2$ at most of the farms with fabric coverlet and naturally farmed housing and $6{\sim}7birds/m^2$ at seven farms (of 9 farms) with a steel panel-framed housing. The daily feed intake of 11 farms (55%) was between 120 and 130 g, which included 3 farms (15%) with fabric coverlet, 3 farms (15%) with naturally farmed housing, and 5 farms (25%) with steel panel-framed housing. The age of peak production was 24~28 weeks overall 20 farms. Over 80% of production on fabric coverlet, naturally farmed, and steel panel-framed house farms was on 3, 4 and 6 farms, respectively. Respiratory disease on the 20 farms represented 55% of total disease incidence, and of each housing type represented 75% (fabric coverlet), 70% (naturally farmed) and 33% (steel panel-framed). E. coli disease was only found in the steel panel-framed housing. Most of the animal welfare-approved eggs were sold at large markets or a real sale markets. Egg price was 200~250 won per egg. These results indicate the current situation of animal welfare-approved farms and could be caused that windowless poultry house was applied to animal welfare approved farms.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.4
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• pp.41-54
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• 2002

In this study, we have analyzed the effects of the membrane layer and the bragg reflector layers on the resonance characteristics through comparing the characteristics of the membrane type FBAR (Film Bulk Acoustic Wave Resonator) and the one type bragg reflector layers with those of the ideal FBAR with top and bottom electrode contacting air by using equivalent circuit technique. It is assumed that ZnO is used for piezoelectric film, $SiO_2$ are used for membrane layer and low acoustic impedance layer, W are used for the high acoustic reflector layer and Al is used for the electrode. Each layer is considered to have a acoustic propagation loss. ABCD parameters are picked out and input impedance is calculated by converting 1-port equivalent circuit to simplified equivalent circuit that ABCD parameters are picked out possible. From the variation of resonance frequency due to the change of thickness of electrode layers, reflector layers and membrane layer it is confirmed that membrane layer and the reflector layer just under the electrode have the greatest effect on the variation of resonance frequency. From the variation of resonance properties, K and electrical Q with the number of layers, K is not much affected by the number of layers but electrical Q increases with the number of layers when the number of layers is less than seven. The electrical Q is saturated when the number of layers is large than six. The electrical Q is dependent of mechanical Q of reflector layers and membrane layer. Both ladder filter and SCF (Stacked Crystal Filters) show higher insertion loss and out-of-band rejection with the increase of the number of resonators. The insertion loss decreases with the increase of the number of reflector layers but the bandwidth is not much affected by the number of reflector layers. Ladder Filter and SCF with membrane layer show the spurious response due to spurious resonance properties. Ladder filter shows better skirt-selectivity characteristics in bandwidth but SCF shows better characteristics in insertion loss.

• Korean Journal of Agricultural Science
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• v.21 no.2
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• pp.122-132
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• 1994

Bacteriostatic activity of secretory immumoglobulin A (SIgA) in human and bovine colostrums on enterotoxigenic type Salmonella was tested in the tissue culture medium. SIgA was used in $0.1{\sim}5.0mg/m{\ell}$ concentration with or without the addition of egg lysozyme tested for theirs bacteriostatic activites. 1. Bovine SIgA rich fraction with a large amount of $IgG_1$-dimer could be prepared from bovine colostrum of Holstein cows by anion exchange chromatography using DEAE-Sephadex A-50 and gel filtration on Sephadex G-200 and Sepharose 6B. 2. Human SIgA appeared to be the most bacteriostatic effect for all varieties of Salmonella in a range of $0.5{\sim}1.0mg/m{\ell}$ Bovine SIgA showed a marked bacteriostatic effect increased by increasing the concentration. Bovine IgG had not show bacteriostatic effect against both enterotoxigenic type Salmonella. Egg lysozyme as well as bovine SIgA also showed a marked bacteriostatic effect increased by increasing the concentration. 3. When the growth inhibition of human SIgA was tested by adding egg lysozyme with time interval, egg lysozyme showed bacteriostatic effect as compared with control. But human SIgA and adding with lysozyme showed slight the bacteriostatic effect. 4. When the growth inhibition of bovine SIgA was tested by adding egg lysozyme with time interval, all treatment against S. enteritidis showed bacteriostatic effect as compared with control In the case of S. typhinwrium, egg lysozyme showed a marked bacteriostatic effect as compared with control.