• Journal of the Korean Geotechnical Society
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• v.24 no.10
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• pp.5-15
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• 2008

The purpose of this study is to examine the validity of recycled aggregates (RAs) as a substitute for Sand-Mat material for soft ground improvement in the housing site development. To evaluate the possibility of RAs as a substitute for sand mat material, first of all, the criteria and regulations related with the quality of lateral drain layer were collected and checked. Secondly, both of the properties of RAs were compared with the properties of natural sand for the lateral drain layer. The material properties related to coefficient of permeability, pressure at-rest state and so on satisfied most standards. On the basis of the test results, RAs were used to the construction site as lateral drain layer. Accordingly, if the quality of RAs can be managed well, the application of these RAs as lateral drain layer to replace natural sand was highly effective. Also, based on cost analysis of two materials, RAs are proved to be very competitive.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.373-382
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• 2003

Magnesium ion ($Mg^{2+}$) is a vasodilator, but little is known about its mechanism of action on vascular system. In vitro, extracellular magnesium sulfate ($MgSO_4$) produced relaxation in phenylephrine (PE) or high KCl-precontracted isolated rat thorocic aorta with (+E) or without (-E) endothelium in a concentration-dependent manner. The $MgSO_4$-induced relaxations were not affected by removal of the endothelium. Pretreatment of +E or -E aortic rings with nitric oxide synthase (NOS) inhibitors ($20{\mu}M$ L-NNA, $100{\mu}M$ L-NAME, $1{\mu}M$ dexamethasone and $400{\mu}M$ aminoguanidine), cyclooxygenase inhibitor ($10{\mu}M$ indomethacin), guanylate cyclase inhibitors ($10{\mu}M$ ODQ and $30{\mu}M$ methylene blue) and $Ca^{2+}$ transport blocker ($10{\mu}M$ ryanodine) did not affect the relaxant effects of $MgSO_4$. $Ca^{2+}$ channel blockers ($0.3{\mu}M$ nifedipine and $0.5{\mu}M$ veropamil) completely decreased the relaxant effects of $MgSO_4$ in +E and -E aortic rings. However, in $Ca^{2+}$-free medium, $MgSO_4$-induced vasorelaxation was potentiated and this response was inhibited by nifedipine. Protein kinase C (PKC) inhibitors ($1.0{\mu}M$ staurosporine, $0.5{\mu}M$ tamoxifen and $0.1{\mu}M$ H7) or PLC inhibitor ($100{\mu}M$ NCDC) markedly decreased the relaxant effects of $MgSO_4$ in +E and -E aortic rings. In vivo, infusion of $MgSO_4$ elicited significant decreases in arterial blood pressure. After intravenous injection of nifedipine ($150{\mu}g/kg$) and NCDC (3 mg/kg), infusion of $MgSO_4$ inhibited the $MgSO_4$-lowered blood pressure markedly. However, after introvenous injection of saponin (15 mg/kg), L-NNA (3 mg/kg), L-NAME (5 mg/kg), indomethacin (2 mg/kg), methylene blue (15 mg/kg) and aminoguanidine (10 mg/kg) failed to inhibit it. These results suggest that endothelial NQ-cGMP or prostaglandin pathway is not involved in vasorelaxant or hypotensive action of $Mg^{2+}$ and that these effects are due to the inhibitory action of $Mg^{2+}$ on the $Ca^{2+}$ channel or PLC-PKC pathway, and are due to the competitive influx of $Mg^{2+}$ and $Ca^{2+}$ through the $Ca^{2+}$ channel.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.1
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• pp.64-75
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• 2009

The shipbuilder's requirement for a higher power output rating has led to the development of a super large two stroke low speed diesel engines. Usually a large-sized bore engine ranging from $8{\sim}14$ cylinders, this engine group is capable of delivering power output of more than 100,000 bhp at maximum continuous rating(mcr). Other positive aspects of this engine type include higher thermal efficiency, reliability, durability and mobility. This plays a vital role in meeting the propulsion requirement of vessels, specifically for large container ships, of which speed is a primary concern to become more competitive. Consequently, this also resulted in the modification of engine parameters and new component designs to meet the consequential higher mean effective pressure and higher maximum combustion pressure. Even though the fundamental excitation mechanisms unchanged, torsional vibration stresses in the propulsion shafting are subsequently perceived to be higher. As such, one important viewpoint in the initial engine design is the resulting vibration characteristic expected to prevail on the propulsion shafting system(PSS). This paper investigated the torsional vibration characteristics of these super large engines. For the two node torsional vibration with a nodal point on the crankshaft, a tuning damper is necessary to reduce the torsional stresses on the crankshaft. Hence, the tuning torsional vibration damper design and compatibility to the shafting system was similarly reviewed and analyzed.

• Journal of Life Science
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• v.23 no.2
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• pp.157-166
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• 2013

This study aimed to investigate whether nociceptin contributes to the alterations in cerebral blood flow (CBF) regulation following postnatal exposure to ethanol in Sprague-Dawley rats. Animals received ethanol twice a day, 2 hr apart, on postnatal 6, 7 and 8 days. The changes in regional CBF (rCBF) in response to the changes in mean arterial blood pressure were determined at 4-, 8-, and 12-week of age by laser-Doppler flowmetry. Hypotension was induced by the gradual withdrawal of blood from arterial catheter, and the reversal of blood pressure was produced by the reinfusion of blood. Expression of nociceptin-like immunoreactivity was determined in dura mater and cerebral cortex using immunohistochemistry. Postnatal exposure to ethanol almost abolished the autoregulation of rCBF in all age groups. Pretreatment with nociceptin but not with [$Nphe^1$]nociceptin(1-13)$NH_2$, a selective competitive nociceptin receptor antagonist, 5 min prior to ethanol administration preserved the autoregulation of rCBF in all age groups. Postnatal exposure to ethanol markedly increased the expressions of nociceptin-like immunoreactivity in the dura mater and cerebral cortex, both of which were significantly inhibited by pretreatment with 7-nitroindazole monosodium salt as well as aminoguanidine 5 min prior to ethanol administration in all age groups. The values of arterial blood gas analysis were not significantly different from the basal levels in all groups. These results suggest that nociceptin deeply contributes to the compensatory mechanisms for the nitric oxide-dependent alterations in CBF autoregulation following postnatal exposure to ethanol.

• Korean small business review
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• v.42 no.4
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• pp.173-212
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• 2020

Interest in sustainable management based on the stakeholder perspective is expanding not only within an organization but also across the supply chain. For large companies that have established networks, sustainability management of the supply chain is now a factor that not only determines the social performance of the company as a whole, but also determines its long-term competitive position. Despite these changes in the business world, especially the proliferation of the sustainable supply chain management (SSCM) system, systematic research on SSCM has been lacking. In particular, there was a lack of empirical analysis on which factors promoted the establishment of the SSCM system for large companies and what's the effects of SSCM. In this regard, this study analyzes i) the impact of the social responsibility pressure of customers as external stakeholders and the CSR orientation of purchasing managers as internal stakeholders on supply chain transparency and partnership cooperation respectively, and ii) whether supply chain transparency and partnership cooperation can enhance corporate reputation. The samples used in this study were 69 large companies representing Korea. The results showed that the social responsibility pressure of customers and the purchasing manager's CSR orientation were positively related to the transparency of the supply chain. However, for partnership cooperation, only the purchasing manager's CSR orientation was found to have a positive and significant effect. Meanwhile, both supply chain transparency and partnership cooperation were positively related to the corporate reputation. At the end of the study, discussions on the implications of the results and future research directions will be presented.

• Korean Journal of Culture and Social Issue
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• v.28 no.4
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• pp.529-553
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• 2022

The present study aimed to examine the mediation effect of identity development between perceived parental academic achievement pressure (PPAAP) and mental health. Specifically, we examined whether the relation between PPAAP and mental health is mediated by the positive or negative aspects of identity development. Participants were 110 Korean college students. They completed online self-report questionnaires that included PPAAP, identity development, personal well-being, and depression. We found that PPAAP was negatively related to personal well-being and positively related to depression. Moreover, the relation between PPAAP and mental health was mediated only by the negative aspects of identity development. In other words, PPAAP was related to the negative aspects of identity development, which, in turn, was negatively associated with mental health. This study contributes to the literature in that it proposed identity development as a mediator between PPAAP and mental health and found that the negative, not positive, aspects of identity development mediated the relation. We suggest that institutional interventions that help develop identity can be an effective way to mitigate the negative impacts of PPAAP on mental health of children living in the highly competitive Korean society. Limitations and future research directions are also discussed.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.1
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• pp.49-57
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• 2004

The effect of gas sparging on continuous fermentative $H_2$ production was investigated using external gases ($N_2$, $CO_2$) with various flow rates (100, 200, 300, 400 ml/min). Gas sparging showed a higher $H_2$ yield than no sparging, indicating that the decrease of $H_2$ partial pressure by gas sparging had a good effect on $H_2$ fermentation. Especially, $CO_2$ sparging was more effective in the reactor performance than $N_2$ sparging. The composition of butyrate, the main metabolic product of $H_2$ fermentation by Clostridium sp., was much higher in $CO_2$ sparging. $H_2$ production increased with increasing flow rate only in $CO_2$ sparging. The best performance was obtained by $CO_2$ sparging at 300 ml/min, resulting in the highest $H_2$ yield of 1.65 mol $H_2/mol$ hexoseconsumed and the maximum $H_2$ production of 6.77 L $H_2/g$ VSS/day. Compared to $N_2$ sparging, there could be another beneficial effect in $CO_2$ sparging apart from lowering down the $H_2$ partial pressure. High partial pressure of $CO_2$ had little effect on $H_2$ producing bacteria but inhibitory effect on other microorganisms like lactic acid bacteria and acetogens which were competitive with $H_2$ producing bacteria.

• KDI Journal of Economic Policy
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• v.13 no.1
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• pp.167-197
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• 1991

This paper is intended as an introductory essay to explain endogenous changes in the scope of firm activities in the competitive structure of a deregulated, multi-product financial industry. Recently, the global financial industry has been experiencing a widespread reshuffling in its activities, reflecting both consolidation and specialization. The spread of the universal banking system, which involves the integration of various kinds of financial activities, has resulted in the so-called financial supermarket. At the same time, the traditional set of banking activities has been unbundled into so-called financial boutiques. A relevant question is where the current reshuffling process of integration and disintegration in financial activities might lead the financial industry. However, presently popular theories of the financial industry are not really appropriate for the analysis of this issue. This paper attempts to integrate the theory of specialization [George J. Stigler, "The Division of Labor is Limited by the Extent of the Market," Journal of Political Economy, Vol. LIX, No.3, June 1951] and the theory of the multi-product firm [William J. Baumol, John C. Panzar, and Robert D. Willig, Contestable Markets and the Theory of Industry Structure, Harcourt Brace Jovanovich, Inc., New York, 1982] and to apply the resulting hybrid theory, a theory on the scope of financial activity, to the financial industry. The implications of this theory for the issues raised above are formalized under five hypotheses on the reshuffling of financial activities as listed below: Hypothesis I: The differences in the organization of financial industries among countries are determined by differences in the size of the financial markets, other things being equal. Hypothesis II: A financial firm will separate those financial activities simultaneously having relatively strong economies of scale and relatively weak economies of scope (alternatively, diseconomies of scope) from other activities. Conversely, the firm will integrate those activities simultaneously having relatively weak economies of scale (alternatively, diseconomies of scale) and relatively strong economies of scope with incumbent activities. Hypothesis III: A competitive equilibrium in the deregulated financial industry will consist of both specialized and multi-product financial firms, resulting in a mixed form of specialized and universal banking systems. Hypothesis IV: As world financial markets fully integrate and all countries consequently face this single, common world market, the financial structures of individual countries will become increasingly similar. Hypothesis V: A more universal banking system will dominate the deregulated financial industry in countries with relatively small financial markets, while a more specialized banking system will dominate in countries with relatively large financial markets. However, equilibrium will ultimately be mixed, with specialized and universal banks coexisting, as stated in Hypothesis III. Based on these hypotheses, this paper interprets the historical development of specialized vs. universal banking systems in major industrial countries as a process driven by the evolution of the financial market in each country - i.e. the change in the size of the financial market over time. In addition, this paper anticipates that the final equilibrium of the world financial industry, which is currently under the pressure of financial innovations and deregulation, will be a mixed equilibrium with both specialized boutiques and universal supermarket-type financial firms, instead of an exclusively specialized or universal banking system. Future research should seek continued theoretical elaboration and empirical verification of this paper's hypotheses.

• Korean Journal of Social Welfare
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• v.57 no.3
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• pp.5-30
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• 2005

Globalization has conflicting effects on pharmaceutical policies. A change into a 'populist competitive nation' due to globalization strengthens policies to reduce drug manufacturing costs while the WTO's TRIPS Agreement that is affected by multinational pharmaceutical companies increases drug manufacturing costs by bolstering the patent rights on new drugs. Currently, the independency of populist nations' policies to reduce drug manufacturing cost is being compromised because multinational organizations(such as the European Union) which represents the interests of the multinational pharmaceutical companies put restrictions on the pharmaceutical policies of populist nations for purposes of promoting the industrial goals of the multinational companies. Korea is no exception. Up until the late 1990s, the main feature of the pharmaceutical policies in Korea was keeping the drug price at the cost level based on a growth-driven ideology, and this was Korea's unique policy tools as a developing nation. However, the increase in the power of multinational pharmaceutical companies currently infringes on the independency of Korea's pharmaceutical policies. Expensive imported drugs were originally covered by the national health insurance plan, but starting from 1999 such drugs began to be covered by the plan. After separation of medical and pharmaceutical services, the use of expensive drugs was increased, and the Korean government planned to introduce the reference price policy in order to contain the cost of the national health insurance plan. However, due to pressures from the U.S. government as well as multinational pharmaceutical companies, implementation of the policy has been postponed. In addition, due to a pressure from the U.S. government, a working group was created which would affect the health care policy of the Korean government. Discussions so far on globalization was about whether the change into populist competitive nations due to globalization resulted in the reduction of welfare spending. However, this study shows not only the reduction of health care cost through policies to reduce drug manufacturing costs but increase in welfare spending by raising the strengths of multinational pharmaceutical companies that are for-profit providers of welfare service. While focusing on the contradictory effects of globalization on pharmaceutical policies of a nation, this study looked at how these conflicting effects end up promoting the interests of multinational pharmaceutical companies by examining the Korean case.

• Journal of Animal Science and Technology
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• v.52 no.2
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• pp.83-90
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• 2010

Hanwoo proven bulls have been selected since 1987 and consequently contributed to farmers for the improvement of beef cattle in Korea. The demand for the quality beef production as well as higher production efficiency was erupted after early 2000 as relatively cheap imported beef released. Therefore the pressure on the reformation of selection index for Hanwoo proven bulls have been piled up to furnish with Hanwoo's competitive. A total of 734 progeny test data were analyzed to select traits and their weights in the selection index to meet the beef market requirement. Regression analysis with stepwise selection method was used to select proper trait and its weight for selection index. A series of computer simulation was carried out to compare the currently using selection index with the alternate two selection indices proposed in this study. New selection index using standardized breeding values of Loin eye Muscle Area (LMA), Backfat Thickness (BFT) and Marbling Score (MS) with weight ratio 1:-1:6 was proposed. Results showed higher performance in improving MS and BFT gain by 22% and 31% still holding 86%~89% of genetic gain achieved by current index in Carcass Weight (CW) and LMA when new selection index was fitted. Because, new index has little consideration for production cost, further research should be performed to build selection index including cost and income simultaneously.