• Journal of Internet Computing and Services
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• v.10 no.4
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• pp.35-44
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• 2009

The emerging notion of data stream has brought many new challenges to the research communities as a consequence of its conceptual difference with conventional concepts of just data. One typical example is data stream processing in sensor networks. The range of data processing considerations in a sensor network is very wide, from physical resource restrictions such as bandwidth, energy, and memory to the peculiarities of query processing including continuous and specific types of queries. In this paper, as one of the physical constraints in data stream processing, we consider the problem of limited memory and propose a new scheme for data stream reduction based on the Principal Component Analysis (PCA) technique. PCA can transform a number of (possibly) correlated variables into a (smaller) number of uncorrelated variables. We adapt PCA for the data stream of a sensor network assuming the cooperation of a query engine (or application) with a network base station. Our method exploits the spatio-temporal correlation among multiple measurements from different sensors. Finally, we present a new framework for data processing and describe a number of experiments under this framework. We compare our scheme with the wavelet transform and observe the effect of time stamps on the compression ratio. We report on some of the results.

• Journal of KIISE
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• v.43 no.2
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• pp.229-236
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• 2016

Theta join is one of the essential and important types of queries in database systems. As the amount of data needs to be processed increases, processing theta joins with a single machine becomes impractical. Therefore, theta join algorithms using distributed computing frameworks have been studied widely. Although one of the state-of-the-art theta-join algorithms uses M-Bucket-I heuristic, it is hard to use since running time of M-Bucket-I heuristic, which computes a mapping from a record to a reducer (i.e., reducer mapping), is O(n) where n is the size of input data. In this paper, we propose MBI-I algorithm which reduces the running time of M-Bucket-I heuristic to $O(r_{max}log\;n)$ and gives the same result as M-Bucket-I heuristic does. We also conducted several experiments to show algorithm and confirmed that our algorithm can improve the performance of a theta join by 10%.

• Journal of Information Management
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• v.42 no.4
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• pp.115-136
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• 2011

Recently, the cases of archiving for digital contents are being increased throughout the world. Owing to the characteristics of digital contents including the issues on volatile property and authenticity, preservation weakness, and aging in the reproductive tool, it requires special management for long-term preservation. A successful digital archiving seems to be possible in the stage-oriented practice through the cooperation of interested organizations based on the systematically established and stipulated policy. This is the basic study that was designed for the establishment of the policy on digital contents archiving in KISTI(Korea Institute of Science and Technology Information), which is a representative organization for the distribution of science and technology information. By investigating and analyzing the cases of overseas policies on digital contents archiving, it intended to understand the framework of digital archiving policy while suggesting measures on the macroscopic items that were included in the archiving policies through the interview conducted to expert groups.

• Smart Media Journal
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• v.1 no.2
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• pp.12-22
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• 2012

Today we are witnessing an increasingly widespread use of cameras in our lives for video surveillance, robot vision, and mobile phones. This has led to a renewed interest in computer vision in general and an on-going boom in human activity recognition in particular. Although not particularly fancy per se, human gait is inarguably the most common and frequent action. Early on this decade there has been a passing interest in human gait recognition, but it soon declined before we came up with a systematic analysis and understanding of walking motion. This paper presents a set of DBN-based models for the analysis of human gait in sequence of increasing complexity and modeling power. The discussion centers around HMM-based statistical methods capable of modeling the variability and incompleteness of input video signals. Finally a novel idea of extending the discrete state Markov chain with a continuous density function is proposed in order to better characterize the gait direction. The proposed modeling framework allows us to recognize pedestrian up to 91.67% and to elegantly decode out two independent gait components of direction and posture through a sequence of experiments.

• Journal of Korea Game Society
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• v.11 no.2
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• pp.161-166
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• 2011

In this paper, we propose a novel background segmentation and feature point extraction method of a human motion for the augmented reality game. First, our method transforms input image from RGB color space to HSV color space, then segments a skin colored area using double threshold of H, S value. And it also segments a moving area using the time difference images and then removes the noise of the area using the Hessian affine region detector. The skin colored area with the moving area is segmented as a human motion. Next, the feature points for the human motion are extracted by calculating the center point for each block in the previously obtained image. The experiments on various input images show that our method is capable of correct background segmentation and feature points extraction 12 frames per second.

• Journal of the Korea Society of Computer and Information
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• v.15 no.3
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• pp.45-53
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• 2010

When the user's role is getting more important in contents communicated online, we must know that the cultural trait of content that is reflecting user's mental model, needs and tastes. An attempt to study about cross-cultural characteristics focused on contents of global website give us the best chance to understand user. This paper takes a look if there are any linkages between certain country and its preferable contents and analyze that whether this preference is result from the cultural differences or not. This analysis is based on Hofstede's and Schwartz's framework. So, this content analysis examines cultural influence on the contents of global website in Korea and U.S and Japan and China. The results provide CIC(Cultural Index of Content) which is extended framework adding interaction. We expect that it can help service providers and content creators to have some new ideas.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.433-439
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• 2016

For the past hundred years, since many films have only been focusing on expressing suppressed desire and obsession, there have been few films in which unconsciousness desire is expressed and pursuing dream comes true as Freud says. Well known for a convoluted and dreamy structure and plot, David Lynch successfully represents a real dream sequence with his own way of image presentation form in his representative film "Mulholland Drive (2001)". In this study, I attempt to analyze how he expresses the realistic dream sequence with a strange film structure based on Freud's psychoanalysis. In general, dream world is known as completely visual matter, but the feeling of things is more important for making a realistic dream and it is the main reason that we can have more realistic experiences in a dream.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.2
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• pp.106-113
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• 2009

Recently, due to many industrial accidents at construction sites, a variety of researches for structural health monitoring (SHM) of buildings are progressing. For real site application of SHM, one of the advanced technologies has blown as wireless sensor networks (WSN). In this paper, we proposed WIVA(WSN Monitoring framework based on 3D Visualization and Augmented Reality in Mobile Devices) system that applies 3D visualization and AR technology to mobile devices with camera based on WSN in order to expand the extent of information can observe. Moreover, we performed experiments to validate effectiveness in 3D and AR mode that utilize WSN data based on IEEE 802.15.4. In real implementation scenario, we demonstrated a fire occurrence test in 3-story building miniature.

• The Journal of Society for e-Business Studies
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• v.10 no.4
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• pp.1-18
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• 2005

In ebXML, a representative framework for electronic commerce, a BPS (Business Process Specification) should be finally defined as an instance of XML-version BPSS for the configuration of B2B (Business to Business) runtime systems . In order to define the instance more complete and consistent, it is required to validate all the semantic constraints on the instance . Due to the limitations of XML Schema constructs, however, current XML-version BPSS fails to specify formal semantic constraints completely. This paper presents how to find, express and reuse BPSS semantic constraints that could not be explicitly defined in the XML-version BPSS. The method facilitates the validation of XML-version BPSS instances easily with some useful guides for fixing violations of semantic constraints. Furthermore, B2B business processes can be standardized and applied more efficiently and effectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7582-7588
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• 2015

Noncoherent receivers are favored for block-code-modulated ultrawideband impulse radio (UWB-IR) systems because of their low implementation complexity compared with coherent rake receivers. However, existing noncoherent schemes, such as transmitted reference (TR) systems and averaged differential receivers (ADR), suffer from performance degradation and energy efficiency loss. Codeword matching and signal aggregation (CMSA) is a low complexity noncoherent receiver for UWB-IR. As the frame/symbol duration is shortened to boost data rate, interframe interference (IFI) or intersymbol interference (ISI) occurs and degrades the detection performance of CMSA. In this paper, block coded correlator which consists of the delay components and the reference signal is proposed to improve the performance of the receiver. Simulation results show that the proposed system leads to the better performance compared to the conventional CMSA receiver.