• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.629-634
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• 2000

Comparing with single structure constructed with reinforced concrete or steel, composite structures have a great advantage. However, in case of nuclear power structure, the application of a conventional single structure (reinforced concrete or steel structure) inflicts a heavy loss on a economical and constructive efficiency. But, the application of composite slab to nuclear power structure could compensate these deficiency. Therefore, in this study, the structural behavior of composite slab in nuclear power structure is observed to assure economical and constructive efficiency.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.211-212
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• 2008

As a result of environmental concerns, the production of electricity through renewable energy resources is rapidly increasing. Wind energy is among the fastest growing renewable energy resources now being integrated in the power system, and the penetration rate of wind generation has been gradually increased. For power flow analysis of the recent systems, thus, steady-state modeling of wind turbines and their application are of great importance. This paper presents the procedure we applied for implementation of a steady-state wind turbine model in power flow.

• Journal of National Security and Military Science
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• s.4
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• pp.241-287
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• 2006

16th CPC National Party Congress established multi-polarization strategy as an external strategy, and 'The Great Reinvigoration of Chinese Nation' as the aim of The Great Strategy of China. It is required to maintain stabilized and peaceful surrounding circumstance in order to make it possible. The ideal surrounding circumstance that China is aiming for is to achieve multi-polarization of international society while maintaining strategic deterrence. Multi-polarization now in 'One super Multi powers' is that 'Multi powers' deter 'One super' to prevent predominance of USA and to decentralize the power. China wishes to realign international order as it accomplishes multi-polarization. China who wants 'Peace and Stabilization' emphasizes autonomy, peace and unification of Korean peninsula. Autonomy means the restraint intervention of foreign power, that is, American influence in Korean peninsula. Multi-polarization strategy of China will be used in Korean peninsula to solve nuclear issue of North Korea, to support neutral unification and to keep balance of power with USA, Japan and Russia as it renders economic advantages to South Korea and security engagement to North Korea, based on special geographical, cultural and historical relationship with two Koreas. The nuclear issue of North Korea will be a stage to test multi-polarization of China. When it deduces positive solution of nuclear issue due to successful six-party talks, and advances to security talks of Northeast Asia, it will contribute a lot to power and elevation of national stature of China in international society. Thus, the Chinese strategy will be an accommodative condition for the security of South Korea, and it requires wise decision of South Korea to make hay while the sun shine.

• International Journal of Advanced Culture Technology
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• v.10 no.3
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• pp.127-145
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• 2022

Vaccine diplomacy is a manifestation of competition for political influence among great powers amidst the Covid-19 pandemic's blatant illustration of ineluctable interdependency across the global community. The reinforcement of trends bolstering global polity construction intensify concomitantly with nationalist populist value and attitude expressions increasing political polarization. The interdependency graphically illustrated in the Cold War-era's mutual assured destruction incentivized competition into indirect competitive intervention in the internal politics of third actors. Indirect international influence contestations included extended, de facto challenge competitions to generate soft power on behalf of the victor, e.g., the space race. The Covid-19 pandemic has intensified this competition to offer alternative development models while intense domestic political polarization undermines the mobilizational capacities for achieving sustainable development. In contrast to multinational and multiethnic states, nation states have an inherent mobilizational advantage because of the enhanced control capabilities available to the authorities without emphasizing coercion. Control through Gramscian hegemonic mechanisms is more readily feasible in nation states through the greater feasibility of commodification of social relations by states authorities regulating and channeling social competition to encourage social mobility and creativity. The regulation of the so-called private sector serves to manage and contain social competition while channeling it to develop the institutional capacities for control and allocation of developing societal human resources. It enhances developed state control mechanisms and international influence capacities. The appeal of offers of aid and assistance to the so-called developing world becomes ever more urgent amidst Anthropocene crises including its most recent, current Covid-19 pandemic disaster.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.763-775
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• 2021

The thermal hydraulic performances of Steam Generator (SG) under both steady and transient operation conditions are of great importance for the safety and economy in nuclear power plants. In this paper, based on our self-developed SG thermal hydraulic analysis code STAF (Steam-generator Thermalhydraulic Analysis code based on Fluent), an improved new version STAF-CT (fully Coupling and Transient) is developed and introduced. Compared with original STAF, the new version code STAF-CT has two main functional improvements including "Transient" and "Fully Three Dimensional Coupling" features. In STAF-CT, a three dimensional energy transferring module is established which can achieve energy exchange computing function at the corresponding position between two sides of SG. The STAF-CT is validated against the international benchmark experiment data and the results show great agreement. Then the U-shaped SG in AP1000 nuclear power plant is modeled and simulated using STAF-CT. The results show that three dimensional flow fields in the primary side make significant effect on the energy source distribution between two sides. The development of code STAF-CT in this paper can provide an effective method for further SG high fidelity research in the nuclear reactor system.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.4
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• pp.344-353
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• 2023

In the actual sea, the additional resistance due to external force such as wind, current and wave is accompanied, and the required power is added in response to these resistance. Especially when the ship is sailing at low speed, the effects of wind and current have a great impact on the safe control of the ship. Likewise, it is thought that the effects of wind and current have a great impact on the trawl ship control since the towing speed of a bottom trawl ship is a low speed of 3 to 4 knots. If the reduce of ship speed and the increase of engine power due to the influence of wind and current can be identified, the safe towing power can be calculated based on a given engine output. Thus, the appropriate size of a fishing gear can be determined. In this study, a total of 20 trawl operations were conducted for seasonal maritime research in the same research area according to the operation mode of propeller. Based on navigation data, trawl fishing data, and engine performance data acquired during the towing fishing gear, and data of ship speed, hull resistance, fishing gear resistance, wind force and current force according to an incidence angle were estimated. The overall power for these loads was calculated and compared with the measured engine power, and the effects of wind force and current force on the engine power were investigated.

• The Plant Pathology Journal
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• v.17 no.1
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• pp.1-8
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• 2001

The technique of plant transformation has started to show off its great power in the area of plant breeding by commercially successful introduction of transgenic varieties such as herbicide tolerant soybean and insect resistant corn in USA with an unimaginable speed. However, in contrast with the great success in the commercialization of herbicide tolerance and insect resistance, the transformation works on disease resistance has not yet reached the stage of full commercialization. This review surveys the current status of molecular breeding for plant disease resistance and their limits and problems. Some novel ideas and approaches in molecular breeding for disease resistance are introduced.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.4
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• pp.41-45
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• 2013

Modern electronic devices such as tablets and smartphones are getting more powerful and efficient. The demand in feature sets, functionality and usability increase exponentially and this has posed a great challenge to the design of a power distribution network (PDN). Power rails merging is a popular option used today in a PDN design as numerous power rails are no longer feasible due to form factor limitation and cost constraint. In this paper, the criteria and limitations for power rails merging are discussed. Despite having all the advantages such as pin count reduction, decoupling capacitors sharing, lower impedance and cost saving, power rails merging can however, introduce coupling noise to the system. In view of this, a PDN design with power rails merging that fulfills design recommendations and specifications such as noise target, power well placement, voltage supply values as well as power supply quadrant assignment is extremely important.

• Transactions of The Korea Fluid Power Systems Society
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• v.5 no.2
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• pp.14-19
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• 2008

Hydraulic excavator consists of booms, arms, bucket, and cylinder. The cylinder make these structures moved and the cushion parts of cylinder in operation absorb the great impact which is stemmed from high velocity and pressure at cushion parts of cylinders. The cushion technology of cylinders has a great effect on the operator's comfortable as well as protecting equipment from damage by suppressing the inertia of the hydraulic excavator. In this study, three hydraulic cylinders have different shapes of a cushion ring, respectively. we studied optimal cushion pattern by analyzing the change of cushion pressure and time, according to supply pressure and velocity variations.

• Journal of the Korean Institute of Navigation
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• v.24 no.5
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• pp.417-422
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• 2000

The 3rd order intermodulation(IM3) signals affect a great influence on fundamental signal because IM3 can not be rejected by a filter. To solve this problem, in this paper, a predistortion method was applied. The designed predistorter cascaded to 4 W power amplifier and tested with two-tone spreaded 5 MHz. As an experimental result, it was cleary shown that the 3rd order intermodulation distortion characteristics has been improved as much as 17 dB when the output of the power amplifier is 30.67 dB.