• Journal of Communications and Networks
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• v.10 no.2
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• pp.156-162
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• 2008

Cooperative relays can provide spatial diversity and improve performance of wireless communications. In this paper, we study subcarrier power allocation at the relays for orthogonal frequency division multiplexing (OFDM)-based wireless systems. For cooperative relay with amplify-and-forward (AF) and decode-and-forward (DF) algorithms, we investigate the impact of power allocation to the mutual information between the source and destination. From our simulation results on word~error-rate (WER) performance, we find that the DF algorithm with power allocation provides better performance than that of AF algorithm in a single path relay network because the former is able to eliminate channel noise at each relay. For the multiple path relay network, however, the network structure is already resistant to noise and channel distortion, and AF approach is a more attractive choice due to its lower complexity.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.120-122
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• 2017

정보통신기술의 발달에 따라 컴퓨터, 스마트폰과 같은 스마트 기기가 대중화됨에 따라 개인 블로그나 SNS 등을 기반으로 하여 개인이 다양한 콘텐츠를 생산하고 공유하는 커뮤니케이션 플랫폼인 1인 미디어가 활성화 되었다. 효율적으로 1인 방송시스템을 구축하기 위해서는 기존 방송 시스템의 체계는 유지하면서 개인의 협소한 공간을 효율적으로 활용할 수 있는 방안을 요구하게 된다. 따라서 본 논문에서는 각각의 방송장비들을 노트북, 어플과 같은 스마트 기기와 연동시켜 효율적이고 편리한 1인 미디어 방송 시스템을 구축하기 위한 방법을 제안하였다.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.325-330
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• 2001

Shizhuyuan W-Mo-Bi-Ca $F_2$polymetallic ore is classified to the refractory one due to its complex property, fine dissemination and close association of minerals. Through several years of researches, in line with GY new mineral processing technology developed by Guangzhou Research Institute of Nonferrous Metals, in sulfide flotation circuit, an iso-flotability flowsheet is used to replace original overall bulk flotation flowsheet, and in tungsten flotation circuit, a new chelating type-GY reagent and a special pulp-conditioning system and a new technology of wolframite slime flotation are used to replace the traditional "Caustic Soda Method"$_{［1］}$, the metallurgical performance is greatly improved. Besides, GY New Method has created a favorable condition for comprehensive recovery of fluoride from tungsten flotation tailings. Notable economic benefit has been achieved.d.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2007.02a
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• pp.139-151
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• 2007

Decision-making in the crisis management happens in dynamic, rapidly changing, and often unpredictable distributed environments. Crisis management Decision Support Systems (DSSs) in E-Government are challenged by the need to use it availably at anytime, from anywhere, and even under any-situation. In this paper the reasons of developing distributed architecture for crisis management Decision Support Systems (DSSs) in E-Government are analyzed. Consequently, a distributed architecture for crisis management Decision Support System (DSS) is proposed in this paper. Finally it is implemented by Web Services. If crisis management Decision Support System (DSS) based on distributed architecture is implemented by Web Service, then it can provide decision support for decision-makers to deal with crisis at anytime, from anywhere, and even under any-situation.

• Research in Mathematical Education
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• v.22 no.4
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• pp.305-318
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• 2019

To improve students' classroom engagement is not only the demand of curriculum revolution, but also the reflection of learning democracy. Students' responses and thinking are the main manifestations of students' participation in classroom learning. To reduce the amount of questions and increase the opportunities and time for students to think, this study, by employing SPSS, makes attempts to analyze the data by using multivariate GLM analysis to explore the effects of students' responses and thinking on learning results. The results indicated the students learning effect will be promoted through reducing the quantity and increasing the quality of question and adding the thinking opportunities.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1121-1127
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• 2014

The design, synthesis, and structural characterization of two new palladium complexes based on Schiff base ligands is reported; $[Pd(L1)_2]$ (1) and $[Pd(L2)_2]$ (2), [HL1 = 2-((E)-(2,6-diethylphenylimino)methyl)-4,6-dibromophenol, L2 = (E)-N-benzylidene-2,6-diethylbenzenamine], which are obtained by functionalizing Schiff base ligands with or without electron-withdrawing groups. Both compounds are mononuclear structures. Comparisons are made to the compounds 1 and 2 to analyze and understand the effect of electron-withdrawing groups. Antibacterial activity studies indicate the electron-withdrawing groups on Schiff base ligands enhance antibacterial activity. Catalytic activity, however, is reduced due to the enhanced steric-hindrance of the electron-withdrawing groups. Electronic absorption and emission properties of HL1, L2, 1 and 2 are also reported.

• International Journal of CAD/CAM
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• v.1 no.1
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• pp.23-32
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• 2002

In this paper, a new technique of space deformation for parametric surfaces with so-called extension function (EF) is presented. Firstly, a special extension function is introduced. Then an operator matrix is constructed on the basis of EF. Finally the deformation of a surface is achieved through multiplying the equation of the surface by an operator matrix or adding the multiplication of some vector and the operator matrix to the equation. Interactively modifying control parameters, ideal deformation effect can be got. The implementation shows that the method is simple, intuitive and easy to control. It can be used in such fields as geometric modeling and computer animation.

• Journal of Information Processing Systems
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• v.16 no.3
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• pp.572-587
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• 2020

Experience API provides a learner-centered model for learning data collection and learning process recording. In particular, it can record learning data from multiple data sources. Therefore, Experience API provides very good support for ubiquitous learning. In this paper, we put forward the architecture of ubiquitous learning system and the method of reading the learning record from the ubiquitous learning system. We analyze students' learning behavior from two aspects: horizontal and vertical, and give the analysis results. The system can provide personalized suggestions for learners according to the results of learning analysis. According to the feedback from learners, we can see that this u-learning system can greatly improve learning interest and quality of learners.

• Bulletin of the Korean Chemical Society
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• v.14 no.6
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• pp.740-743
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• 1993

By considering both electron-electron and electron-lattice interactions, the effect of charge transfer on the bond structure and electronic states of $C_{60}$ is studied without configuration limitation. The results show that the electron-electron interaction does not eliminate the layer structure of the bond distortion and the self-trapping of transferred electrons. For charged ${C_{60}}^{2-}$, there exist two localized electronic states, which possess laminar wave functions, and four nonequivalent groups of carbon atoms, which induce a fine-structure in the NMR spectrum line.

• Bulletin of the Korean Chemical Society
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• v.22 no.6
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• pp.565-569
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• 2001

The spectral correction matrix has been established to study the simultaneous complextions between metals and a ligand, and it eliminated the mutual influence among the complexes. The two sensitive reations between iron(Ⅱ) and 1-(6-bromo-2-benzothiazolylazo)-2-naphthol(BBTAN) and zinc (Ⅱ) and BBTAN have been investigated and applied to the simultaneous determination of Zn and Fe at pH 8.5 in the presence of triton x-100. This method gave the simples determination of the characteristic constants of the complexes. For the analysis of natural water, foods and other samoles, the recoveries of Fe and Zn were between 92 and 109% and between 91 and 104%, and their relative standard deviations were less than 5.5 and 11%, respectively.