• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6081-6088
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• 2012

An unequal clustering method in wireless sensor networks is the technique that forms the cluster of different size. This method decreases whole energy consumption by solving the hot spot problem. In this paper, I propose a layer-based dynamic unequal clustering using the unequal clustering model. This method decreases whole energy consumption and maintain that equally using optimal cluster's number and cluster head position. I also show that proposed method is better than previous clustering method at the point of network lifetime.

• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.476-479
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• 2013

$CoSb_3$ with its high electrical conductivity, Seebeck coefficient and rather low thermal conductivity is quite a promising material for thermoelectric conversion applications. A potentially high figure of merit (ZT) can be achieved by a nanostructure evolution of thermoelectric materials. In this work, $CoSb_3$ nanoparticles were synthesized through a thermal decomposition method in cooperation with a hot injection technique. Nano-sized $CoSb_3$ particles were obtained through the thermal decomposition reaction between the pre-heated cobalt-oleate at $320^{\circ}C$ and the injected antimony oleate with room temperature. The results showed that the particle size was increased with increasing synthesis temperature and the crystallinity of particles was improved with temperature but the decomposition of $CoSb_3$ was observed at $320^{\circ}C$. The $CoSb_3$ particles synthesized at $300^{\circ}C$ showed a high purity and an homogeneous shape with average particle size of 26 nm.

• International Journal of Control, Automation, and Systems
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• v.1 no.2
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• pp.236-242
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• 2003

This paper presents a cooperation strategy between a human operator and autonomous robots for an interactive robot soccer game, The interactive robot soccer game has been developed to allow humans to join into the game dynamically and reinforce entertainment characteristics. In order to make these games more interesting, a cooperation strategy between humans and autonomous robots on a team is very important. Strategies can be pre-programmed or learned by robots themselves with learning or evolving algorithms. Since the robot soccer system is hard to model and its environment changes dynamically, it is very difficult to pre-program cooperation strategies between robot agents. Q-learning - one of the most representative reinforcement learning methods - is shown to be effective for solving problems dynamically without explicit knowledge of the system. Therefore, in our research, a Q-learning based learning method has been utilized. Prior to utilizing Q-teaming, state variables describing the game situation and actions' sets of robots have been defined. After the learning process, the human operator could play the game more easily. To evaluate the usefulness of the proposed strategy, some simulations and games have been carried out.

• Journal of The Korean Association of Information Education
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• v.17 no.1
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• pp.53-61
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• 2013

The proximity web 2.0 has in our daily life changes in the way we educate ourselves occur naturally. New generations of learners naturally study and utilize web 2.0 as part of general life, so they require an education method which considers this characteristic. One such method, WIKI Based Cooperation Learning has recently been studied. The object of this study is to establish any relationship between learners attitude and academic achievements when implementing WIKI Based Cooperation Learning in the subject of social studies.

• Nuclear Engineering and Technology
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• v.29 no.6
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• pp.488-499
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• 1997

The measurements of the moderator temperature coefficient (MTC) are performed to demonstrate that the calculational model produces results that are consistent with the measurements. Since negative MTC is also a technical specification value that may limit the cycle length, it is important to measure it as accurately as possible. In this report, preferred choice of test method depending on the time in cycle, best power indication and temperature definition in MTC calculation were determined based on the MTC test results taken during initial startup testing and at 2/3 cycle burnup in the Yonggwang nuclear power plant. The results show that the ratio and rodded methods provided good agreement with the predictions during initial startup testing. However, near end-of-cycle the depletion method gives better results, and so is suggested to be used in the MTC measurements at 2/3 cycle burnup. The use of primary Delta T power as a power indicator in the MTC calculations is highly advisable since it responds with good consistent results very quickly to changes unlike secondary calorimetric power. For the appropriate temperature definitions used in the MTC calculations, it is considered that the arithmetic average temperature measured simply by inlet and outlet thermocouples is preferred. Although volumetric average temperature provides better results, the improvement is not sufficient to compensate for the simplicity of calculations by arithmetic average temperature.

• Fire Science and Engineering
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• v.21 no.3
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• pp.1-7
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• 2007

This research was conducted through demonstrating method about how high cooperation level between crisis management systems against terror in korea is now, based on both interaction level relating to cooperation relation among organization relationship theory. Through the results of analysis, People in charge against terror were widely recognizing about the need of cooperation between crisis management systems to treat terror effectively. For organic cooperation between organizations, it was suggested the politic implication that it is the most important task to build the sense of values, the behavior about cooperations in the internal phase of crisis management system.

• ETRI Journal
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• v.38 no.5
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• pp.941-951
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• 2016

In this paper, cognitive radio and simultaneous wireless information and power transfer (SWIPT) are effectively combined to design a spectrum-efficient and energy-efficient transmission paradigm. Specifically, a novel SWIPT-based primary-secondary cooperation model is proposed to increase the transmission rate of energy/spectrum constrained users. In the proposed model, a multi-antenna secondary user conducts simultaneous energy harvesting and information forwarding by means of power splitting (PS), and tries to maximize its own transmission rate under the premise of successfully assisting the data delivery of the primary user. After the problem formulation, joint power splitting and beamforming optimization algorithms for decode-and-forward and amplify-and-forward modes are presented, in which we obtain the optimal PS factor and beamforming vectors using a golden search method and dual methods. Simulation results show that the proposed SWIPTbased primary-secondary cooperation schemes can obtain a much higher level of performance than that of non-SWIPT cooperation and non-cooperation schemes.

• International Journal of Advanced Culture Technology
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• v.5 no.1
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• pp.1-8
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• 2017

The purpose of the present study is to examine the effect of civic cooperation with the police on the number of crime that the police must solve by conducting simulation based on system dynamics. The study sets police oriented-policing model and police-citizen cooperative model to investigate the effect of civic cooperation with the police. As a result of the simulation, the police oriented-policing model shows that the number of crime that police must solve is increasing over time, while the police-citizen cooperative model shows that the number of crime that must be solved by the police is keeping it stable in the increase of crimes. Comparing both models, civic cooperation with the police is more effective in reducing or deterring crime than police oriented-policing activity. The study proves that building cooperative relationship between citizens and the police can become a strategic method for controlling crime effectively without a rapid increase in police finance. It is meaningful in terms of presenting a dynamic change of interaction for reducing crimes between civic cooperation with the police and policing activity of the police over time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3289-3295
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• 2010

In business material management, as the number of products and their parts increases, the employment of databases becomes inevitable. Many researchers have tried to incorporate semantics in traditional models using logic programming, resulting in the deductive method. However, since the designer of this method does not overcome the traditional design concept of relational method, there have been not much successful implementations in deductive method. Therefore, this paper propose the new way designing the retrieval methods for deductive databases and using those relations the query that makes recursive retrievals possible and hypotheses test in business material management.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.34-34
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• 2017

Various extracts of roots, stems, and leaves of Phalaenopsis Sogo Yukidian 'V3' were evaluated for total phenolics, total flavonoids, and antioxidant capacity. The conjugate form of stem samples contained the highest total phenolics ($5.092{\pm}0.739mg$ gallic acid equivalent per g dry weight） and the highest total flavonoids ($2.218{\pm}0.021mg$ rutin equivalent per g dry weight) was found in the hexane extract of leaves. The ethyl acetate extract of roots showed the maximum antioxidant activity as compared to other extracts. Of which, the $IC_{50}$ value of this sample were 0.070 mg/mL and 0.450 mg/mL in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and reducing power, respectively, while the lipid peroxidation inhibition (LPI) value was as 94.2% by ${\beta}$-carotene bleaching method. Five phenolic compounds including caffeic acid, syringic acid, vanillin, ellagic acid, and cinnamic acid were quantified by high-performance liquid chromatography (HPLC). It is suggested that roots of the hybrid Phalaenopsis Sogo Yukidian 'V3' can be explodited as an effective source of antioxidants.