• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.4
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• pp.325-334
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• 2008

The standard prestressed concrete I-girder bridge (PSC I-girder bridge) is one of the most prevalent types for small and medium bridges in Korea. When determining the member forces in a section to assess the safety of girder in this type of bridge, the general practice is to use the simplified practical equations or the live load distribution factors proposed in design standards rather than the precise analysis through the finite element method or so. Meanwhile, the live load distribution factors currently used in Korean design practice are just a reflection of overseas research results or design standards without alterations. Therefore, it is necessary to develop an equation of the live load distribution factors fit for the design conditions of Korea, considering the standardized section of standard PSC I-girder bridges and the design strength of concrete. In this study, to develop an equation of the live load distribution factors, a parametric analysis and sensitivity analysis were carried out on the parameters such as width of bridge, span length, girder spacing, width of traffic lane, etc. As a result, the major variables to determine the size of distribution factors were girder spacing, overhang length and span length in case of external girders. For internal adjacent girders, the determinant factors were girder spacing, overhang length, span length and width of bridge. For internal girders, the factors were girder spacing, width of bridge and span length. Then, an equation of live load distribution factors was developed through the multiple linear regression analysis on the results of parametric analysis. When the actual practice engineers design a bridge with the equation of live load distribution factors developed here, they will determine the design of member forces ensuring the appropriate safety rate more easily. Moreover, in the preliminary design, this model is expected to save much time for the repetitive design to improve the structural efficiency of PSC I-girder bridges.

• Journal of Korean Society of Forest Science
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• v.89 no.2
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• pp.275-284
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• 2000

This study was carried out to analyze the mechanical properties of soil and the slope stability on the fill slope of forest road constructed in the regions which consist of igneous and metamorphic rock area. The results were summarized as follows. 1) Soil type by Unified Soil Classification System(USCS) was classified as SW in soil slope, GP in weathered rock slope, GP in soft rock slope for both types of parent rock, but gravelly soil slopes in igneous and metamorphic rock area were classified as SP and GW, respectively. 2) Dry unit weight was $1.34g/cm^2{\sim}1.59g/cm^2$, specific gravity 0.57~0.61, and void ratio 0.66~0.93 in the case of igneous rock area, a dry unit weight was $1.35g/cm^2{\sim}1.51g/cm^2$, specific gravity 2.67~2.77, and void ratio 0.78~1.01 in the case of metamorphic rock area. 3) The strength parameters such as internal friction angle(${\phi}$) and cohesion(c) were selected and tested for slope stability analysis. ${\phi}$ and c of soil in igneous rock area were within the range of $29.51^{\circ}{\sim}41.82^{\circ}$ and $0.03kg/cm^2{\sim}0.38kg/cm^2$, respectively, and $21.43^{\circ}{\sim}41.43^{\circ}$ and $0.05kg/cm^2{\sim}0.44kg/cm^2$ in metamorphic rock area, respectively. 4) Result of the slope stability analysis of forest road showed that, in the weathered rock slope of igneous rock and the weathered rock and soil slope of metamorphic rock area, the possibility of slope failure was high as safety factor was below 1.0.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.265-271
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• 2004

A feeding trial was conducted to investigate the influence of feeding Lactobacillus reuteri culture (LR) on productive performance, intestinal microflora and availability in laying hens. Four hundred and eighty, Isa-Brown layers, 49 weeks of age, were fed diets supplemented with LR at the level of 0 (control), 0.1, 0.2, and $0.4\%$ of the diets for eight weeks. Egg production and egg weight were measured daily. Feed intake was weighed every two weeks. Egg quality was measured three times at the start, mid-term, and end of the experiment. Intestinal microflora were examined for Lactobacillus spp., E. coli and Salmonella at the end of the experiment. Overall egg production was the highest in $0.2\%$ LR (P<0.05), but that of $0.1\%$ or $0.4\%$ LR treatments did not significantly differ from that of control. Egg weight was significantly higher in LR feeding group than the control (P<0.05). Daily egg mass was significantly higher in $0.2\%$ and $0.4\%$ LR treatments compared to the control and $0.1\%$ LR (P<0.05). The number of jumbo and extra large eggs were increased in LR supplemented groups, especially in $0.1\%$ LR. Feed intake of layers fed LR supplemented diets tended to be lower than the control. However, feed conversion ratio significantly improved in LR supplemented groups (P<0.05). Availability of dry matter and crude protein improved significantly in $0.4\%$ LR treatment (P<0.05). But, those of ether extract and crude ash were not significantly different among treatments. Eggshell breaking strength and eggshell thickness were not significantly influenced by LR supplementation, and Haugh unit and yolk index were also similar to the control. Total number of Lactobacillus spp. in ileum and cecum fed LR supplemented diets were significantly higher than those of the control (P<0.05). There were no significant differences in intestinal E. coli and Salmonella in all treatments. Therefore, it is concluded that dietary supplementation of Lactobacillus reuteri culture can improve the laying performance, feed efficiency and intestinal Lactobacillus.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.99-111
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• 2018

In this study three target radionuclides ($^{60}Co$, $^{137}Cs$, and $^{125}Sb$) were reacted with solid samples collected from the nuclear facility sites to investigate their sorption and mobility behaviors for preparing unexpected nuclear accidents. The highest sorption distribution coefficients ($K_{ds}$) of target radionuclides ($^{60}Co=947mL/g$, $^{137}Cs=2105mL/g$, $^{125}Sb=81.3mL/g$) were found in topsoil layer under groundwater condition, and the $K_d$ values of three radionuclides decreased in the order of fractured rock and bedrock samples under the same groundwater condition. High $K_d$ values of $^{60}Co$ in topsoil layer and fracture rock resulted from the clay minerals present, and the $K_d$ values decreased 58-69 % under seawater condition due to high ionic strength. $^{137}Cs$ sorption was controlled by the ion exchange reaction with $K^+$ on flayed edge sites (FES) of mica. The $^{137}Cs$ sorption was the most affected by seawater (89-97 % decrease), while $^{125}Sb$ sorption was not much affected by seawater. As the results of column and batch experiments, the retardation factors (R) of $^{137}Cs$, $^{60}Co$, and $^{125}Sb$ were determined about 5400-7400, 2000-2500, and 250-415, respectively, indicating no significant transport for these radionuclides even in fractured zone with groundwater. These results suggest that even in the case of severe nuclear accident at the nuclear facilities the mobility of released radionuclides ($^{60}Co$, $^{137}Cs$, and $^{125}Sb$) can be significantly retarded by the topsoil layer and fractured rock. In addition, the results of this study will be used for the safety and environmental performance assessment of nuclear facilities.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.1
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• pp.38-53
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• 2007

In a seminal judgment of November 2002 (Case C-476/98) relating to the compatibility with Community laws of the 'nationality clause' in the 1996 amending protocol to the 1955 U.S.-German Air Services Agreement, the European Court of Justice(ECJ) decided that the provision constituted a measure of an intrinsically discriminatory nature and was thus contrary to the principle of national treatment established under Art. 52 of the EC Treaty. The Court, rejecting bluntly the German government' submissions relying on public policy grounds(Art. 56, EC Treaty), seemed content to declare and rule that the protocol provision requiring a contracting state party to ensure substantial ownership and effective control by its nationals of its designated airlines had violated the requirement of national treatment reserved for other Community Members under the salient Treaty provision. The German counterclaims against the Commission, although tantalizing not only from the perusal of the judgment but from the perspective of international air law, were nonetheless invariably correct and to the point. For such a clause has been justified to defend the 'fundamental interests of society from a serious threat' that may result from granting operating licenses or necessary technical authorizations to an airline company of a third country. Indeed, the nationality clause has been inserted in most of the liberal bilaterals to allow the parties to enforce their own national laws and regulations governing aviation safety and security. Such a clause is not targeted as a device for discriminating against the nationals of any third State. It simply acts as the minimum legal safeguards against aviation risk empowering a party to take legal control of the designated airlines. Unfortunately, the German call for the review of such a foremost objective and rationale underlying the nationality clause landed on the deaf ears of the Court which appeared quite happy not to take stock of the potential implications and consequences in its absence and of the legality under international law of the 'national treatment' requirement of Community laws. Again, while US law limits foreign shareholders to 24.9% of its airlines, the European Community limits non-EC ownership to 49%, precluding any ownership and effective control by foreign nationals of EC airlines, let alone any foreign takeover and merger. Given this, it appears inconsistent and unreasonable for the EC to demand, $vis-{\grave{a}}-vis$ a non-EC third State, national treatment for all of its Member States. The ECJ's decision was also wrongly premised on the precedence of Community laws over international law, and in particular, international air law. It simply is another form of asserting and enforcing de facto extraterritorial application of Community laws to a non-EC third country. Again, the ruling runs counter to an established rule of international law that a treaty does not, as a matter of principle, create either obligations or rights for a third State. Aside from the legal problems, the 'national treatment' may not be economically justified either, in light of the free-rider problem and resulting externalities or inefficiency. On the strength of international law and economics, therefore, airlines of Community Members other than the designated German and U.S. air carriers are neither eligible for traffic rights, nor entitled to operate between or 'free-ride' on the U.S. and German points. All in all and in all fairness, the European Court's ruling was nothing short of an outright condemnation of established rules and principles of international law and international air law. Nor is the national treatment requirement justified by the economic logic of deregulation or liberalization of aviation markets. Nor has the requirement much to do with fair competition and increased efficiency.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.2
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• pp.59-158
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• 2005

When a military aircraft suffers damages due to the defects in its design, manufacturing or notification, all of which are generally understood as products liability defects, the obvious compensation is sought as it would in other consumer good case. However, there exist clear yet unappreciated difference between general consumer goods and military aircraft, as far as products liability law is concerned - some sort of recovery should be obtained even when there exist only defects, not damages, to the aircraft because of the implication of defective parts is much grave than what can be expected in a consumer goods case. While certain anticipatory measures do exist in manual or at negotiation stages for the safety of military aircraft, such measures are ineffective, if not ambiguous, in recovery effort in the post-accident stage In another word, the standardized military procurement contract manuals and boilerplate forms do not appreciate the unique and dangerous military nature of military aircraft. There are many unique legal issues which can arise when trying to prevent defective aircraft or parts, or to recover compensations for accident due to such defects. At two-level, the government should establish legal system (or countermeasures if you'd like) for purchasing safer military aircraft. First, one should be able to work with legal ground and policy that allows selecting and purchasing safer goods - the purpose of such contract is not litigious, but rather in acquiring what are most reliable. Second, in case the defects do arise and lead to damages, solid legal principles and instructions should be established for effectively pursuing appropriate company, (usually a aerospace industry giant with much experience) for products liability - the purpose of such pursuit is inevitable for a public official, since he or she is no private business man with much flexibilities, even to the point of waiving such compensatory right for future business purposes. This article tries to identify problems in methods of procuring military aircraft or parts - after reviewing on how the military can improve on legal and policy grounds for procuring what will be the focus of future military strength, it will offer some of the ways to effectively handling and resolving a liability issues.

• KDI Journal of Economic Policy
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• v.32 no.4
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• pp.153-195
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• 2010

The recent global financial crisis has been the outcome of, among other things, the mismatch between institutions and the reality of the market in the current global financial system. The International financial institutions (IFIs) that were designed more than 60 years ago can no longer effectively meet the challenges posed by the current global economy. While the global financial market has become integrated like a single market, there is no international lender of last resort or global regulatory body. There also has been a rapid shift in the weight of economic power. The share of the Group of 7 (G7) countries in global gross domestic product (GDP) fell and the share of emerging market economies increased rapidly. Therefore, the tasks facing us today are: (i) to reform the IFIs -mandate, resources, management, and governance structure; (ii) to reform the system such as the international monetary system (IMS), and regulatory framework of the global financial system; and (iii) to reform global economic governance. The main focus of this paper will be the IMS reform and the role of the Group of Twenty (G20) summit meetings. The current IMS problems can be summarized as follows. First, the demand for foreign reserve accumulation has been increasing despite the movement from fixed exchange rate regimes to floating rate regimes some 40 years ago. Second, this increasing demand for foreign reserves has been concentrated in US dollar assets, especially public securities. Third, as the IMS relies too heavily on the supply of currency issued by a center country (the US), it gives an exorbitant privilege to this country, which can issue Treasury bills at the lowest possible interest rate in the international capital market. Fourth, as a related problem, the global financial system depends too heavily on the center country's ability to maintain the stability of the value of its currency and strength of its own financial system. Fifth, international capital flows have been distorted in the current IMS, from EMEs and developing countries where the productivity of capital investment is higher, to advanced economies, especially the US, where the return to capital investment is lower. Given these problems, there have been various proposals to reform the current IMS. They can be grouped into two: demand-side and supply-side reform. The key in the former is how to reduce the widespread strong demand for foreign reserve holdings among EMEs. There have been several proposals to reduce the self-insurance motivation. They include third-party insurance and the expansion of the opportunity to borrow from a global and regional reserve pool, or access to global lender of last resort (or something similar). However, the first option would be too costly. That leads us to the second option - building a stronger globalfinancial safety net. Discussions on supply-side reform of the IMS focus on how to diversify the supply of international reserve currency. The proposals include moving to a multiple currency system; increased allocation and wider use of special drawing rights (SDR); and creating a new global reserve currency. A key question is whether diversification should be encouraged among suitable existing currencies, or if it should be sought more with global reserve assets, acting as a complement or even substitute to existing ones. Each proposal has its pros and cons; they also face trade-offs between desirability and political feasibility. The transition would require close collaboration among the major players. This should include efforts at the least to strengthen policy coordination and collaboration among the major economies, and to reform the IMF to make it a more effective institution for bilateral and multilateral surveillance and as an international lender of last resort. The success on both fronts depends heavily on global economic governance reform and the role of the G20. The challenge is how to make the G20 effective. Without institutional innovations within the G20, there is a high risk that its summits will follow the path of previous summit meetings, such as G7/G8.

• Food Science and Preservation
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• v.19 no.2
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• pp.193-200
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• 2012

The quality characteristics of $kalopanax$ $pictus$ and Aralica elata shoots during their preservation were investigated according to the salt conditions and storage temperatures to improve the use of the shoots. The results were as follows: the pH of $kalopanax$ $pictus$ shoots duing their storage did not changes with 10% and 12% brine at $4^{\circ}C$ and with 12% brine at $10^{\circ}C$. The pH of $Aralica$ $elata$ shoots is at $4^{\circ}C$ tended to be similar to the $kalopanax$ $pictus$ shoot and decreased at the storage temperature of $10^{\circ}C$. The salinity of the $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to increase during their storage and did not change significantly as their storage temperature changed. The L values of $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to decrease gradually during their storage, and the salt concentrations appeared high. The b value of the $kalopanax$ $pictus$ shoot tended to increase and that of the $Aralica$ $elata$ shoots, to decrease gradually. The a value tended to increase gradually but did not differ with variations in the storage temperatures and salt concentrations. The strength and the hardness of the $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to decreased gradually during their storage and highest in 10% brine at $4^{\circ}C$, and those of $Aralica$ $elata$ shoots were highest in 8-10% brine at $4^{\circ}C$. The Chlorophyll contents of the $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to decrease during their salt storage and did not change significantly as the temperatures and salt concentrations changed. Therefore, it can be concluded that the quality of $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots can be maintained when the are stored in 10% brine at $4^{\circ}C$.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.296-305
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• 2006

The adsorption and persistence of pencycuron {1-(4-chlorobenzyl) cyclopentyl-3-phenylurea} in soils were investigated under laboratory and field conditions to in order to assess the safety use and environmental impact. In the adsorption rate experiments, a significant power function of relation was found between the adsorbed amount of pencycuron and the shaking time. Within one hour following the shaking, the adsorption amounts in the SCL and the SiCL were 60 and 65% of the maximum adsorption amounts, respectively. The adsorption reached a quasi-equilibrium 12 hours after shaking. The adsorption isotherms followed the Freundlich equation. The coefficient (1/n) indicating adsorption strength and degree of nonlinearity was 1.45 for SCL and 1.68 to SiCL. The adsorption coefficients ($K_d$) were 2.31 for SCL and 2.92 to SiCL, and the organic carbon partition coefficient, $K_{oc}$, was 292.9 in SCL and 200.5 inSiCL. In the laboratory study, the degradation rate of pencycuron in soils followed a first-order kinetic model. The degradation rate was greatly affected by soil temperature. As soil incubation temperature was increased from 12 to $28^{\circ}C$, the residual half life was decreased from 95 to 20 days. Arrhenius activation energy was 57.8 kJ $mol^{-1}$. Furthermore, the soil moisture content affected the degradation rate. The half life in soil with 30 to 70% of field moisture capacity was ranged from 21 to 38 days. The moisture dependence coefficient, B value in the empirical equation was 0.65. In field experiments, the half-life were 26 and 23 days, respectively. The duration for period of 90% degradation was 57 days. The difference between SCL and SiCL soils varied to pencycuron degradation rates were very limited, particularly under the field conditions, even though the characteristics of both soils are varied.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.331-337
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• 2016

Several foundation soil conditions below a homogeneous sand slope were assumed and slope stability analyses were conducted to determine the soil condition, in which a stabilizing pile can be used to increase the factor of safety against sliding. The assumed heights of the sand slope were 5m and 10m. For a 5m slope height, a stabilizing pile can be used in the foundation soil with a $15^{\circ}$ internal friction angle and a cohesion of 10kPa. For a 10m slope height, a stabilizing pile can be used in the foundation soil with a $20^{\circ}$ internal friction angle and a cohesion of 10kPa and a stabilizing pile can be used in the foundation soil with a $0^{\circ}$ internal friction angle and 40kPa, 45kPa and 50kPa of cohesion. According to the analysis results of stabilizing pile-reinforced foundation soil, the length of the stabilizing pile and magnitude of the maximum bending moment were strongly affected by the internal friction angle of the foundation soil. The lengths of stabilizing pile, for an internal friction angle of $0^{\circ}$ were 4.6, 8.0 times greater than those with an internal friction angle of $5^{\circ}$. The magnitude of the maximum bending moment of the stabilizing pile for an internal friction angle of $0^{\circ}$ was 24.6 times greater than that for an internal friction angle of $5^{\circ}$. Practically, a stabilizing pile cannot be used for foundation soil with an internal friction angle of $0^{\circ}$. Considering the results derived from this study, the effects of a stabilizing pile can be maximized for soft foundation soil that is embanked with a slow construction speed.