• Journal of Families and Better Life
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• v.24 no.1 s.79
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• pp.43-53
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• 2006

The purpose of this study was to explore the attitudes about the management service charge in multi-family housing. Recently, increasing needs of urban families in residential housing management services were apparent in many studies, but the way that they charge for the management services was not dear. Research method was social survey with questionnaire from 484 residents and 84 housing managers of multi-family housing in Seoul and new town area. Research results showed that residents recognized the management services should be free of charge or imposed actual expenses, but managers recognized the management services as charged services. To provide efficient housing management services for residents in multi-family housing, human resources should be inputted. Therefore, this study suggested that the participation of residents in housing management service is recommendable as a way of lessen the economic burden of management service charge, but also to have an opportunity to interest in their community activities.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.9
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• pp.685-689
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• 2009

Flash memory has several features such as low~power consumption and fast access so that there has been various research on using flash memory as new storage. Especially the Solid State Disk which is composed of flash memory chips has recently replaced the hard disk. At present, SSD adopts the multi-channel and multi-way architecture to exploit advantages of parallel access. In this architecture, data are written on SSD in a unit of a superblock which is composed of multiple blocks in which some blocks are put together. This paper proposes two schemes of selecting, segmenting and re-composing victim superblocks to optimize concurrent processing when a buffer flush occurs. The experimental results show that 35% of superblock- based write operations is reduced by selecting victims and additional 9% by composition of superblock.

• Journal of Communications and Networks
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• v.18 no.5
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• pp.677-687
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• 2016

Multi-way relay networks (MWRNs) allow multiple users to exchange information with each other through a single relay terminal. MWRNs are often incorporated with capacity achieving lattice codes to enable the benefits of high-rate signal constellations to be extracted. In this paper, we analytically characterize the symbol error rate (SER) performance of a functional decode and forward (FDF) MWRN in the presence of channel estimation errors. Considering M-ary quadrature amplitude modulation (QAM) with square constellations as an important special case of lattice codes, we obtain asymptotic expressions for the average SER for a user in FDF MWRN. The accuracy of the analysis at high signal-to-noise ratio is validated by comparison with the simulation results. The analysis shows that when a user decodes other users with better channel conditions than itself, the decoding user experiences better error performance. The analytical results allow system designers to accurately assess the non-trivial impact of channel estimation errors and the users' channel conditions on the SER performance of a FDF MWRN with M-QAM modulation.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.513-520
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• 2014

Since the beginning of history, men have done mimesis and produced illusion and succeeded art and culture instinctually. The subject which mention above included the object which can order and space around that. Perspective which began the Renaissance age was dominant way about understanding space in western history and it made modern visual system. Direction way of space which based perspective is changed as horizontal data included multi-layer structure in digital media age. This character make us possible to represent the space more efficiently. So we must have pay attention the direction way of space based on digital media, because it has meaning to show human value beyond a methodology of visual art culture.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.1
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• pp.51-59
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• 2016

The progression of broadcasting technology changed the previous analogue broadcasting system into digital, which in result allowed several broadcasting programs to be transmitted as one stream by multiplexing. This multi channel environment interferes with audience to choose the program they want. EPG acts as supporter in this multi channel environment. The existing EPG system is limited in providing searching function with title, genre, date and Wish-list in multi-media environment. Thus, this thesis proposes new type EPG using PSIP information modification to respond with the change of broadcasting market. This type of EPG can be applied to several kinds of broadcasting systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.163-168
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• 2010

In this paper, we propose novel two-way relaying scheme in which number of two users transmit the signal to number of two destination. The scheme is difference with conventional multi-hop two-way relay scheme in which number of two users exchange the each signal. In the conventional scheme, each user have to perform back-propagating self-interference method to remove the own signal from received signal. It occurred to increase the complexity for signal processing at the user. To overcome the problem, we apply the Pre-cancellation which can reduce the process of back-propagating self-interference to our proposal network Simulation result show that proposal scheme outperform the convention multi-hop two-way relay scheme. Also we analysis the trad-off between performance and complexity accordance with using Pre-cancellation method.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.2
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• pp.152-159
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• 2018

A numerical simulation was conducted to establish the analysis methods of the unsteady conjugated heat transfer with a hot gas valve. Two methods are proposed to reduce the computational cost and analysis time of the unsteady conjugate heat transfer; namely, the multi-section analysis method and the one-way analysis method. The multi-section analysis method exhibits relatively high reliability. In the one-way analysis method, the unsteady conjugate heat transfer from the fluid domain to the solid domain was simulated from the analysis results of the steady-state flowfield. The incipient accuracy of the analysis results obtained by the one-way analysis method was slightly lower than that of the results obtained by the multi-section analysis method. However, the discrepancy became smaller with time, as the analysis progressed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.566-578
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• 2018

In this paper, we design a segment training based individual channel estimation (STICE) scheme for the classical two-way relay network (TWRN) with multi-pair sources (MPS) and amplify-and-forward (AF). We adopt the linear minimum mean square error (LMMSE) channel estimator to minimize the mean square error (MSE) without channel estimation error, where the optimal power allocation strategy from the relay for different sources is obtained. Then the MSE gains are given with different source pairs among the proposed power allocation scheme and the existing power allocation schemes. Numerical results show that the proposed method outperforms the existing ones.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.779-782
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• 2014

맵리듀스(MapReduce)는 대용량 데이터의 병렬 처리에 사용되는 프로그래밍 모델이다. 조인(join)은 둘 이상의 테이블에서 동일한 애트리뷰트 값을 가지는 레코드들을 결합하는 연산으로, 데이터베이스 분야에서 가장 중요한 연산 중 하나이다. 본 논문은 맵리듀스를 이용하여 다중 조인(multi-way)을 효율적으로 처리하는 방법을 제안한다. n개 테이블의 다중 조인을 처리하기 위해 기존 방법은 2-way 조인을 수행하는 맵리듀스 잡을 (n-1)번 수행하거나, 레코드들을 중복시켜 n개 테이블의 조인을 1 개의 맵리듀스 잡으로 한 번에 처리한다. 하지만 전자는 맵리듀스 잡을 (n-1)번 수행해야 하며, 후자는 레코드들을 상당히 많이 중복시켜야 한다는 단점이 있다. 본 논문은 레코드를 전혀 중복시키지 않고도 ${\lceil}{\log}_2n{\rceil}$개의 맵리듀스 잡만으로 다중 조인을 효율적으로 처리하는 방법을 제안한다. 실험을 통해 제안 방법은 기존 방법에 대해 다중 조인을 더 빠르게 처리함을 보인다.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.3
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• pp.92-98
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• 2010

The AHP methodology compares criteria, or alternatives with respect to a criterion, in a natural, pairwise mode. AHP has been applied in a wide variety of applications multi objective decision making being just one. If a group of expert with different aspect, they need some way to revise expert group. We proposed the concatenation of expert to survey the AHP pairwise question for multi-attribute decision making. In this paper, we suggest a way to revise the expert's priorities in hierarch using concept of different group opinion.