• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5A
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• pp.503-509
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• 2007

Low-power motion estimation is required for video coding in portable information devices. In this paper, we propose a low-power motion estimation algorithm and 1-D systolic may VLSI architecture using full search block matching algorithm (FSBMA). Main power dissipation sources of FSBMA are complex computations and frequent memory accesses for data in the search area. In the proposed algorithm, memory accesses and computations are reduced by using 1D PE (processing array) array architecture performing motion estimation of two neighboring blocks in parallel and by skipping unnecessary computations during motion estimation. The VLSI implementation results of the algorithm show that the proposed VLSI architecture can save 9.3% power dissipation and can operate two times faster than an existing low-power motion estimator.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.3-9
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• 2014

ECMA-392 is the first cognitive radio (CR) specification for personal/portable devices in TV white space. It supports two transmit antennas, for which only open-loop transmit diversity schemes are included. In this paper, we design a simple closed-loop transmit diversity scheme using sub-carrier grouping for ECMA-392 systems. First, sub-carrier grouping types suitable for ECMA-392 systems are described, and then a transmit antenna selection scheme is proposed. In order to reduce feedback information, decision on the transmit antenna selection in the given channel environments is made at the receiver side and the only index of the decided transmit antenna is sent to the transmit side. Through performance comparison to open-loop transmit diversity schemes of ECMA-392, it will be shown that with only a slight feedback overhead, the proposed scheme can improve receiver performance of ECMA-392 systems.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.5
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• pp.24-30
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• 2010

In this paper, we described intra prediction which is the one of techniques to be used for higher compression performance in H.264/AVC and proposed the design of intra predictor for efficient intra prediction mode processing. The proposed system is consist of processing elements, precomputation processing elements, an intra prediction controller, an internal memory and a register controller. The proposed system needs the reduced the computation cycles by using processing elements and precomputation processing element and also needs the reduced the number of access time to external memory by using internal memory and registers architecture. We designed the proposed system with Verilog-HDL and verified with suitable test vectors which are encoded YUV files. The proposed architecture belongs to the baseline profile of H.264/AVC decoder and is suitable for portable devices such as cellular phone with the size of $176{\times}144$. As a result of experiment, the performance of the proposed intra predictor is about 60% higher than that of the previous one.

• Journal of Korea Multimedia Society
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• v.8 no.8
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• pp.1088-1098
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• 2005

Context-Aware is a one of the important researches in ubiquitous computing for providing optimal service to users by acquiring user's intentions and environmental information. Diverse researches are focused on the users and its environment facts for Context-Aware base and introduce a sensing based middleware which engages sever/sensor that operates identifier information to provide services. Context-Aware service which is limited by users and environment facts has the problem of overlapping sensing, unnecessary searching and anonymity of users. Also Server-Centric Context-Aware system requires very high cost to manage and operate the services. On this paper, We introduce Autogenous Context service model to simplify the Context-Aware process and design the middleware which performs decentralize management for Context-Aware information of user's portable devices to minimize problems which is occurred during the management and operation of existing Context-Aware system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.71-77
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• 2013

Smart work has been gaining more popularity recently. Smart work means that employees perform their works anytime and anywhere as utilizing the information and communication technology. It can be divided into four categories; the mobile office, the home office, the work-at-center and the tele-cooperation. Among them, the mobile office based on tablet personal computers(PCs) or smart phones, employees can exchange information with tablet PCs or smart phones via mobile radio communication networks and portable terminals. Smart devices such as tablet PCs and smart phones help to access intranet system for requests, approvals, information search whenever employees need. This mobile office system for real-time HSE managing can contribute to improve the productivity and work efficiency in a shipyard. In this study, the main goal is to design the specialized mobile application for the HSE management system on the shipbuilding industry. The mobile application including 10 functions is designed based on ooCBD(object-oriented Component Based Development) methodology.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4B
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• pp.226-234
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• 2005

Context-Aware is the most important facts to reason a personalized and optimized service and to provide it to user. In the previous researches, user and surrounding environment were main facts of Context-Aware and middleware or center server has been proposed to support Context-Aware. In the daily space(for example, home, office, Car, etc), interactions between user and service can be a important facts of Context-Aware. In this paper, Context Autogenesis service model is introduced, simplified the Context-Aware process and designed the middleware which performs decentralize management for Context-Aware information of user's portable devices, so that problems occurred during the management and operation of existing Context-Aware system can be minimized and supporting user anonymity

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.5
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• pp.171-176
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• 2015

Because the specific security technology alone can not cope with sophisticated attacks, various security management models are applied. But, they do not focus on the vulnerability of the highest part because they offer so many common security management criteria. By analyzing the main information and confidential leakage cases inflicting enormous damage to our society, we found that attackers are using mainly an interface vulnerabilities - the paths that connect the internal and external of the organization, such as e-mail, web server, portable devices, and subcontractor employees. Considering the reality that time and resources to invest in security domain are limited, we point out the interface security vulnerabilities the possibility of attackers to exploit and present a convergence method of security measures. Finally, based of ROI(Return on Investment), we propose the real-time security management system through the intensive and continuous management.

• Journal of the Korea Society of Computer and Information
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• v.17 no.8
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• pp.1-10
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• 2012

This paper proposes design space exploration methodology of many-core processors including multimedia specific instructions to support high-performance and low power ultrasound imaging for portable devices. To explore the impact of multimedia instructions, we compare programs using multimedia instructions and baseline programs with a same many-core processor in terms of execution time, energy efficiency, and area efficiency. Experimental results using a $256{\times}256$ ultrasound image indicate that programs using multimedia instructions achieve 3.16 times of execution time, 8.13 times of energy efficiency, and 3.16 times of area efficiency over the baseline programs, respectively. Likewise, programs using multimedia instructions outperform the baseline programs using a $240{\times}320$ image (2.16 times of execution time, 4.04 times of energy efficiency, 2.16 times of area efficiency) as well as using a $240{\times}400$ image (2.25 times of execution time, 4.34 times of energy efficiency, 2.25 times of area efficiency). In addition, we explore optimal PE architecture of many-core processors including multimedia instructions by varying the number of PEs and memory size.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.167-171
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• 2014

While the development of a portable plate panel display, thinning, high color reproduction, high brightness studies have been actively performed. LED, OLED is used as a light source. The research on quantum dot is much accomplished by the material of light source. Such quantum dot is the next generation semiconductor nano fluorescent substance because quantum dot has the high color reproduction and flexible display characteristic. In this study, we presented to method of using the quantum dot for implementation of the plate panel display. Quantum Dot (CdSe/ZnS), having a 100um thickness, is spread in PET barrier film. A Blue LED having a wavelength of 455nm as a light source irradiating light to the optical characteristic of the devices produced and evaluated. Also we presented the possibility for application with the color change film of the LCD.

• Journal of Internet Computing and Services
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• v.6 no.3
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• pp.107-119
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• 2005

The Mobile IP has evolved from providing mobility support for portable computers to support wireless handheld devices with high mobility patterns. The Mobile IP secures mobility, but does not guarantee security, In this paper, the Mobile IP has been adapted to allow AM protocol that supports authentication, authorization and accounting for authentication and collection of accounting information of network usage by mobile nodes, For this goal, we propose a new security handoff mechanism to intensify the Mobile IP security and to achieve fast handoff. In the proposed mechanism, we provide enough handoff achievement time to maintain the security of mobile nodes, According to the analysis of modeling result, the proposed mechanism composed the basic Mobile IP along with AM protocol is up to about $60\%$ better in terms of normalized surcharge for the handoff failure rate that considers handoff time.