• Journal of the Korean Chemical Society
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• v.57 no.5
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• pp.618-624
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• 2013

We demonstrated unique inter- and intra-plasmonic coupling effects in bimetallic Au@Ag core-shell NP arrays which are regularly or randomly arranged on self-assembled block copolymer (BCP) inverse micelle monolayers. Polyvinylpyrrolidone (PVP)-stabilized Au@Ag core-shell NP arrays in regular or disordered configuration were incorporated and assembled on reconstructed PS-b-P4VP inverse micelle templates through two types of processes. The intensively enhanced LSPR coupling properties of individual and assembled Au@Ag NPs were evaluated by UV-visible spectroscopy in terms of the type of ligand stabilizer, coupling between Au and Ag, thickness of Ag shell, and type of array configuration. Finally, Au@Ag core-shell NP arrays were employed as active substrates for surface enhanced Raman spectroscopy (SERS) and a significantly enhanced signal enhancement was observed in accordance with the coupling intensity of Au@Ag NPs patterns.

• Journal of Internet of Things and Convergence
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• v.9 no.1
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• pp.33-39
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• 2023

As the number of people with chronic diseases increases due to an aging society, it is urgent to prevent and manage their diseases. Although biometric authentication methods and Telemedicine Systems have been introduced to solve these problems, it is difficult to solve the security problem of medical information and personal authentication. Since smart healthcare includes personal medical information of subjects, the security of personal information is the most important field. Therefore, in this paper, we tried to propose a Telemedicine System using a smart wearable device ECG in the form of a wristband and face personal authentication in a private blockchain environment. This system targets various medical personnel and patients with chronic diseases in all regions, and uses a private blockchain that can increase data integrity and transparency, ECG and face authentication that are difficult to forge and alter and have high personal identification to provide a system with high security and reliability. composed. Through this, it is intended to contribute to increasing the efficiency of chronic disease management by focusing on disease prevention and health management for patients with chronic diseases at home.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.5
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• pp.54-63
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• 2000

We present a multi-resolution block matching algorithm (BMA) for fast motion estimation At the coarsest level, a motion vector (MV) having minimum matching error is chosen via a full search, and a MV with minimum matching error is concurrently found among the MVs of the spatially adjacent blocks Here, to examine the spatial MVs accurately, we propose an efficient method for searching full resolution MV s without MV quantization even at the coarsest level The chosen two MV s are used as the initial search centers at the middle level At the middle level, the local search is performed within much smaller search area around each search center If the method used at the coarsest level is adopted here, the local searches can be done at integer-pel accuracy A MV having minimum matching error is selected within the local search areas, and then the final level search is performed around this initial search center Since the local searches are performed at integer-pel accuracy at the middle level, the local search at the finest level does not take an effect on the overall performance So we can skip the final level search without performance degradation, thereby the search speed increases Simulation results show that in comparison with full search BMA, the proposed BMA without the final level search achieves a speed-up factor over 200 with minor PSNR degradation of 02dB at most, under a normal MPEG2 coding environment Furthermore, our scheme IS also suitable for hardware implementation due to regular data-flow.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.34-47
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• 2018

As interest in advanced countries regarding the convergence technology development increases, a methodology for identifying the core convergence technology that has a large spill-over effect on the technology and industry is required for the nation's competitiveness enhancement in the convergence technology field. Based on patent citation network analysis using 1,124 USPTO patents in the ICT convergence technology field of the smart factory, this study examined the proposed heterogeneous technology convergence index as a tool for measuring the convergence characteristics of the spillovers compared to other indexes (i.e. other sector ratio index and homogeneous technology convergence index). The proposed heterogeneous technology convergence index was used to investigate core technology sectors among ICT technology sectors of smart factory identified by government ministries. Results found 6 core ICT convergence technology sectors including the manufacturing execution analysis application sector. Also, this study conducted blockmodeling analysis using the IPC codes of patents in the manufacturing execution analysis application sector, and identified that the blocks representing the electronic communication and electric digital data processing technology sectors (Block 3 & 4) are related technology sectors which can be converged with core technology. Based on the findings, the implications for the convergence technology development planning of the smart factory field are discussed.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.5
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• pp.875-888
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• 2021

In this paper, we search integral distinguishers of lightweight block cipher PIPO and propose a key recovery attack on 8-round PIPO-64/128 with the obtained 6-round distinguishers. The lightweight block cipher PIPO proposed in ICISC 2020 is designed to provide the efficient implementation of high-order masking for side-channel attack resistance. In the proposal, various attacks such as differential and linear cryptanalyses were applied to show the sufficient security strength. However, the designers leave integral attack to be conducted and only show that it is unlikely for PIPO to have integral distinguishers longer than 5-round PIPO without further analysis on Division Property. In this paper, we search integral distinguishers of PIPO using a MILP-aided Division Property search method. Our search can show that there exist 6-round integral distinguishers, which is different from what the designers insist. We also consider linear operation on input and output of distinguisher, respectively, and manage to obtain totally 136 6-round integral distinguishers. Finally, we present an 8-round PIPO-64/128 key recovery attack with time complexity 2^124.5849 and memory complexity of 2⁹³ with four 6-round integral distinguishers among the entire obtained distinguishers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3C
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• pp.278-286
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• 2010

Motion Compensated Frame Interpolation(MCFI) has been used to reduce motion jerkiness for dynamic scenes and motion blurriness for LCD-panel display as post processing for large screen and full HD(high definition) display. Conventionally, block matching algorithms (BMA) are widely used to do motion estimation for simplicity of implementation. However, there are still several drawbacks. So in this paper, we propose a novel shape-based ME algorithm to increase accuracy and reduce ME computational cost. To increase ME accuracy, we do motion estimation based on shape of moving objects. And only moving areas are included for motion estimation to reduce computational cost. The results show that the computational cost is 25 % lower than full search BMA, while the performance is similar or is better, especially in the fast moving region.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.995-1004
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• 2010

In the channel-varying environment, it is very important to estimate the signal to noise ratio(SNR) of received signal and to transmit the signal effectively for the modern communication system. The performance of existing non-data-aided (NDA) SNR estimation methods are substantially degraded for high level modulation scheme such as M-ary APSK or QAM. In this paper, we propose a SNR estimation method which uses zero point auto-correlation of received signal per block and auto-/cross- correlation of decision feedback signal in OFDM system. Proposed method can be studied into two Types; Type 1 can estimate SNR by zero point auto-correlation of decision feedback signal based on the second moment property. Type 2 uses both zero point auto-correlation and cross-correlation based on the fourth moment property. In block-by-block reception of OFDM system, these two SNR estimation methods can be possible for the practical implementation due to correlation based the estimation method and they show more stable estimation performance than the previous SNR estimation methods. Also, we mathematically derive the SNR estimation expression according to computational difference of auto-/cross-correlation. Finally, Monte Carlo simulations are used to verify the proposed method.

• Journal of the Institute of Convergence Signal Processing
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• v.17 no.1
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• pp.10-17
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• 2016

GPS location information storage included in the HD black box is using a unique manner for each manufacturer does not have a specific standard. In this paper, in order to overcome the limitations of the storage space and thereby the image quality according to store GPS position information deteriorate to solve the problems that cause, we propose the location information concealment method included in the HDTV video content using a essential hidden region. HDTV video content is a Border Extender of 8 lines in the frame to the bottom of the compression will be required. This was inserted into the image of a gray scale used in block form in order to space the current position information is concealed to prevent image degradation. The proposed method was confirmed using real HD black box, there are more difficult to interpret the format of the ASCII code re-edit the location information when the compression effect disappears with the existing security zones added. Therefore, the proposed method is suitable for location-based services, such as Facebook or Youtube videos.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1411-1414
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• 2006

유비쿼터스 컴퓨팅환경에서는 다양한 서비스가 존재한다. 사용자들은 수많은 서비스들을 사용하기에 앞서 이들이 어디에 있는지, 어떻게 사용해야 하는지를 알아야 한다. SLP, Jini, 그리고 UPnP 같은 대부분의 현존하는 서비스 디스커버리 (Service Discovery) 기술들은 키워드 매치 방법으로 서비스를 검색한다. 이 같은 방식에서는 사용자가 자신이 이용하고자 하는 서비스에 대한 정확한 명칭을 알고 있어야 서비스를 검색할 수 있다. 그러나 유비쿼터스 환경에서는 매우 다양한 서비스가 존재하고, 사용자들 대부분은 해당 서비스의 전문가가 아니기 때문에 정확한 키워드를 선택하여, 원하는 서비스를 찾는데 어려움이 있다. 시맨틱 웹 분야에서 새롭게 떠오른 온톨로지는 특정 분야에서 사용되는 정보의 구조 혹은 용어에 관한 내용을 사용자들이 공유할 수 있도록 정리해놓은 것이다. 본 논문에서는 이러한 온톨로지의 특성을 이용하여, 사용자에게 이용 가능한 서비스에 대한 정보들을 제공하여 사용자가 다양한 서비스를 쉽게 찾아 쓸 수 있는 방법을 제안하였다. 이 방식은 에이전트간의 온톨로지 교환을 통해서 이루어지며, 서비스 블록(Service Block)이라고 불리는 공간 안에서 수행된다. 또한 서비스 컨트롤러(Service Controller)를 이용하여 서비스를 쉽게 사용할 수 있도록 UI 를 제공한다. 본 시스템을 위하여 JENA2, JADE, Aglet, OWL, 그리고 RDQL 이 사용되었다.

• Journal of Internet Computing and Services
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• v.6 no.4
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• pp.103-114
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• 2005

In this paper, we propose a new trnascoding method for improving picture's visual quality when frames are skipped. the proposed method utilizes the relationships of motion vectors between successive frames, and 4 motion vectors a macroblock are considered in transcoding. Since the proposed method does not require any decoding process of encoded bit stream, the computational complexity for estimating motion vectors can be eliminated. Experimental results illustrated that as transcoded frames are getting far from I pictures and as the degree of motions in video sequences are getting higher, the picture quality by using our proposed method shows better performances than existing schemes.