• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.10
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• pp.95-104
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• 2004

This paper propose a motion estimator architecture to reduce the power consumption of the most-power-consuming motion estimation method when designing multimedia SoC with deep submicron technologies below 0.13${\mu}{\textrm}{m}$. The proposed architecture considers both dynamic and static power consumption so that it is suitable for large leakage process technologies, while conventional architectures consider only dynamic power consumption. Consequently, it is suitable for mobile information terminals such as mobile videophone where efficient power management is essential. It exploits full search method for simple hardware implementation. It also exploits early break-off method to reduce dynamic power consumption. To reduce static power consumption, megablock shutdown method considering power line noise is also employed. To evaluate the proposed architecture when applied multimedia SoC, system-level control flow and low-power control algorithm are developed and the power consumption was calculated based on thor From the simulation results, power consumption was reduced to about 60%. Considering the line width reduction and increased leakage current due to heat dissipation in chip core, the proposed architecture shows steady power reduction while it goes worse in conventional architectures.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.12
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• pp.45-51
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• 2010

The main issue in mobile cloud computing is how to support a seamless service to a mobile mode. Mobile IPv6 (MIPv6) is a mobility supporting protocol which is standardized by the Internet Engineering Task Force (IETF). Mobile IPv6 fast handovers (FMIPv6) is the extension of MIPv6 which is proposed to overcome shortcomings of MIPv6. Recently, fast handovers for Mobile IPv6 over IEEE 802.16e which is one of broadband wireless access systems has been proposed by the IETF. It was designed for supporting cross-layer fast handover. In this paper, we propose an enhanced cross-layering mobile IPv6 fast handover over IEEE 802.16e networks. In our scheme, a new access router generates a new address for the mobile node by using a layer 2 trigger. We utilize a layer 2 message which is sent from a new base station to the new access router in order to inform the new access router of information of the mobile node. A previous access router sends a binding update message to the mobile node's home agent when it acquires the new address of the mobile node. We evaluate the performance of the proposed scheme compared with the existing schemes in terms of the signaling cost and the handover latency. From the results, we observe that the proposed scheme can support fast handover effectively over IEEE 802.16e networks than existing schemes.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.2
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• pp.28-34
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• 2012

Various feature extraction algorithms are widely applied to real-time image processing applications for extracting significant features from images. Feature extraction algorithms are mostly combined with image processing algorithms mostly for image tracking and recognition. Feature extraction function is used to supply feature information to the other image processing algorithms and it is mainly implemented in a preprocessing stage. Nowadays, image processing applications are faced with embedded system implementation for a real-time processing. In order to satisfy this requirement, it is necessary to reduce execution time so as to improve the performance. Reducing the time for executing a feature extraction function dose not only extend the execution time for the other image processing algorithms, but it also helps satisfy a real-time requirement. This paper explains FAST (Feature from Accelerated Segment Test algorithm) of E. Rosten and presents FPGA-based embedded hardware accelerator architecture. The proposed acceleration scheme can be implemented by using approximately 2,217 Flip Flops, 5,034 LUTs, 2,833 Slices, and 18 Block RAMs in the Xilinx Vertex IV FPGA. In the Modelsim - based simulation result, the proposed hardware accelerator takes 3.06 ms to extract 954 features from a image with $640{\times}480$ pixels and this result shows the cost effectiveness of the propose scheme.

• Journal of the Korea Concrete Institute
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• v.24 no.2
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• pp.205-214
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• 2012

Crack widths play an important role in the serviceability limit state. When crack widths are controlled sufficiently, the reinforcement corrosion can be reduced using only existing concrete cover thickness due to low permeability in the region of finely distributed hair-cracks. Thus, the knowledge about the tensile crack opening is essential in designing more durable concrete structures. Therefore, numerous researches related to the topic have been performed. Nevertheless accurate measurement of a crack width is not a simple task due to several reasons such as unknown potential crack formation location and crack opening damaging strain gages. In order to overcome these difficulties and measure precise crack widths, a displacement measurement system was developed using digital image correlation. Accuracy calibration tests gave an average measurement error of 0.069 pixels and a standard deviation of 0.050 pixels. Direct tensile test was performed using ultra high performance concrete specimens. Crack widths at both notched and unnotched locations were measured and compared with clip-in gages at various loading steps to obtain crack opening profile. Tensile deformation characteristics of concrete were well visualized using displacement vectors and full-field displacement contour maps. The proposed technique made it possible to measure crack widths at arbitrary locations, which is difficult with conventional gages such as clip-in gages or displacement transducers.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1317-1325
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• 2015

There are two types of clinical research to figure out risk factor for disease using collected data. One is prospective study to approach the subjects from the present time and the other is retrospective study to find the risk factor using the subject's information in the past. Both approached and study design are different but the purpose of the two studies is to identify a significant difference between two groups and to find out what the variables to influence groups. Especially when comparing the two groups in clinical research, we have to look at the difference between the impact clinical variables by group while controlling the influence of the baseline characteristics variables such as age and sex. However, in the retrospective study, the difference of baseline characteristic variables can occur more frequently because the past records did not randomly assign subjects into two groups. In clinical data analysis use covariates to solve this problem. Typically, the analysis method using the analysis of covariance of variance, adjusted model, and propensity score matching method. This study is introduce the way of equality adjustment between groups data analysis using covariates in retrospective clinical studies and apply it to the recurrence of gastric cancer data.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1375-1387
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• 2016

The purpose of this study was to evaluate the effect of exercise on cognitive function in the elderly through a systematic literature review and meta-analysis. For the study purpose, 14 studies were selected through a systematic process of using several databases and 11 studies were used to estimate the effect size of exercise on cognitive function. Meta-analysis was performed using a random effects model, and the effect size on cognitive function was calculated. The effect size for cognitive function of exercise intervention was Hedges' g=1.05 (95% CI: 0.61~1.50), indicating a large effect size. For heterogeneity, moderator analysis was performed using intervention, number of times per week, intervention duration, and cognitive function measurement. Cognitive function measurement was statistically significant, the other moderators did not significant difference. Results support that exercise has significant positive effects on cognitive function in elderly in korea. It also provided a basis that can be applied to exercise intervention design for cognitive function.

• Journal of the Korean Data and Information Science Society
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• v.28 no.2
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• pp.339-348
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• 2017

One of the major issues of statistical process control for variables data is monitoring both the mean and the standard deviation. The traditional approach to monitor these parameters is to simultaneously use two seperate control charts. However there have been some works on developing a single chart using a single plotting statistic for joint monitoring, and it is claimed that they are simpler and may be more appealing than the traditonal one from a practical point of view. When using these control charts for variables data, estimating in-control parameters and checking the normality assumption are the very important step. Nonparametric Shewhart-Lepage chart, proposed by Mukherjee and Chakraborti (2012), is an attractive option, because this chart uses only a single control statistic, and does not require the in-control parameters and the underlying continuous distribution. In this paper, we introduce the Shewhart-Lepage chart, and propose the design procedure to find the optimal diagnosis limits when the location and the scale parameters change simultaneously. We also compare the efficiency of the proposed method with that of Mukherjee and Chakraborti (2012).

• Journal of the Economic Geographical Society of Korea
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• v.6 no.2
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• pp.443-470
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• 2003

This study is to consider economic, political, socio-cultural and environmental characteristics of the new urbanization process and its spatial structures and urban policy of Seoul in the 1990s. Some experimental findings which have been identified throughout this study can be summarized as follows. First of all, Seoul, the largest city in S.Korea has experienced a restructuring process of economy, which has been promoted by the development of producer services as well as knowledge- based or high tech industries. Secondly, the autonomy of Seoul has increased after the introduction of local self-government, with relatively higher self-management of local finance than other cities, strengthening the tendency of enterpreneurialism, empowering civil movements, and increasing the political participation of women. Thirdly, in the socio-cultural aspect, the material wants to gain a certain identity through consumption, using urban environments culturally, varying consuming attitudes and ways of leisure times in relation with the rapid development of transportation and information communication. Fourthly, in the environmental aspect, Seoul has tried to introduce the concept of sustainable development in terms of increasing wants on the quality of life, and to develop a pro-environmental eco-city with environmental rehabilitation, constructing green space and eco-park. Finally, in the spatial dimension, Seoul has shown a structuration of multi-centers, with highly spectacular urban landscapes and seemingly authentic urban planning. These results make us confirm that Seoul has been in the process of new urbanization which can be distinguished from the previous one.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.6
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• pp.487-496
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• 2017

Ground moving target indicator(GMTI) using syntheticaperture radar(SAR) used for finding moving targets on wide background clutter in short time is one of good ways to monitor a traffic situation or an enemy's threat. Although displaced phase center antenna (DPCA) is a real time method with low computational complexity, there have been few studies about its performance against various ground clutters. Thus, we need to analyze GMTI performance for various ground clutters in order to design a suitable DPCA detector. In this paper, simulation results show that the conventional DPCA detector produces different performance in terms of detection rate and false alarm rate. In particular, the false alarm rate of heterogeneous or extremely heterogeneous clutter from urban area is higher than one of homogeneous clutter from natural area.

• Journal of Korea Game Society
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• v.9 no.3
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• pp.107-119
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• 2009

Online games belong to a technology-oriented service industry that has emerged from the assimilation of game contents and communication networks in the respective realms of culture technology (CT) and information technology (IT). This study examines the individual acceptance of online games as entertainment-oriented technology based on the belief-attitude-intention paradigm and the underlying hedonic and utilitarian motivations. To measure the latent variables influencing the acceptance process, a structured questionnaire was developed based on the existing Technology Acceptance Model. Research model analysis and hypothesis testing were carried out using a structural equation model. Results indicated that latent variables reflecting hedonic and utilitarian characteristics had a significant influence on user behavior in the acceptance of online games. By uncovering the core factors in! fluencing the acceptance of online games and thereby theoretically verifying the latent variables influencing the acceptance of entertainment-oriented technology, this study provides strategic implications for business models by game companies aimed at attracting a large user base and dominating the market.