• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.112-120
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• 2013

In this paper, we propose high-performance H.264/AVC CAVLC encoder for UD video real time processing. Statistical values are obtained in one cycle through the parallel arithmetic and logical operations, using non-zero bit stream which represents zero coefficient or non-zero coefficient. To encode codeword per one cycle, we remove recursive operation in level encoding through parallel comparison for coefficient and escape value. In oder to implement high-speed circuit, proposed CAVLC encoder is designed in two-stage {statical scan, codeword encoding} pipeline. Reducing the encoding table, the arithmetic unit is used to encode non-coefficient and to calculate the codeword. The proposed architecture was simulated in 0.13um standard cell library. The gate count is 33.4Kgates. The architecture can support Ultra Definition Video ($3840{\times}2160$) at 100 frames per second by running at 100MHz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.6
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• pp.503-511
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• 2014

In this paper, a novel, real-time video stitching algorithm in an H.264/AVC compressed domain is proposed. This enables viewers to watch multiple video contents using a single device. The basic concept of this paper is that the server is asked to combine multiple streams into one bit-stream based in a compressed domain. In other words, this paper presents a new compressed domain combiner that works in boundary macroblocks of input videos with re-calculating intra prediction mode, intra prediction MVD, a re-allocation of the coefficient table, and border extension methods. The rest of the macroblocks of the input video data are achieved simply by copying them. Simulation experiments have demonstrated the possibility and effectiveness of the proposed algorithm by showing that it is able to generate more than 103 frames per second, stitching four 480p-sized images into each frame.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.430-436
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• 2014

This paper relates to the study about the street security light management system. The purpose of the wireless remote management system is to manage street security lights efficiently. The system is composed of three components like light controller, CDMA gateway and web based remote management server. The zigbee solution is adopted to make local wireless network between street security lights. The CDMA network is used for the wireless communication between street security light controller and the remote control center. The gateway to interconnect zigbee network and CDMA was designed with low power 32 bits Cortex M3 micro-controller. For the data communication between the management server and the gateway, SMS and socket based TCP streaming is used. The management server sends SMS to the gateway to deliver light control and management requests, and the gateway replies with the light controllers report via TCP streaming. By using both SMS and TCP streaming communication, it was verified that simple cost effective management is possible for street security lights. We tried real test for 95 street security lights in real environment during two months and analyzed the practical possibility for mass supply.

• KIEAE Journal
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• v.11 no.2
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• pp.83-90
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• 2011

This study has observed 12 parks (20 spots) in Seoul to know the number of users, gender, age groups for the units of 30 minutes from 06:00AM till 10:00PM. According to the systematic characteristic of the surveyed outdoor exercise place, the details of their users during the summer time were analyzed from the objective viewpoint. Major results of analysis are as follows: Firstly, in case of the riverside of the Han River 07:00AM marked a mini peak and 21:00PM reached the peak, and in case of sub-stream neighborhoods, 21:00PM showed only one peak. On the other hand, in case of neighborhood parks (including pocket park) no peak time was noticeable. Secondly, in case of the riverside of the Han River and the neighborhoods of sub-streams, people used the exercise equipment remarkably at night, and in case of neighborhood parks people used the exercise equipment a little bit more in the morning than in the afternoon. Thirdly, in case of nights in summer the riverside of the Han River was preferred by men, while the neighborhoods of sub-streams were preferred by women and the neighborhood parks showed no difference in the number of users among men and women. Fourthly, differently from men, women do not regard the exercise so seriously as men and their purpose of using outdoor exercise place is to use their leisure time mostly with their family members or neighbors, and women prefer light and comfortable exercises. Fifthly, in summer even those who like to exercise a lot like to exercise in the morning to avoid summer heat. Therefore, provision of shades in summer is very important.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1C
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• pp.28-36
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• 2009

Time-memory trade-off (TMTO) cryptanalysis proposed by Hellman can be applied for the various crypto-systems such as block ciphers, stream ciphers, and hash functions. In this paper, we propose a novel method to reduce memory size for storing TMTO tables. The starting points in a TMTO table can be substituted by the indices of n-bit samples from a sequence in a family of pseudo-random sequences with good cross-correlation, which results in the reduction of memory size for the starting points. By using this method, it is possible to reduce the memory size by the factor of 1/10 at the cost of the slightly increasing of operation time in the online phase. Because the memory is considered as more expensive resource than the time, the TMTO cryptanalysis will be more feasible for many real crypto systems.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.4
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• pp.286-294
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• 2011

Cable modems typically are implemented by a forward error correction(FEC) scheme. The ITU-T Recommendation J-38 Annex B specifies using 64- and 256- quadrature amplitude modulation (QAM) and extended RS coding scheme. In implementing the cable modem, there are some problems to fabricate and fitting on FPGA chip. First, many clocks are needed in implementing cable modem because of different code rate and different modulation types. To reduce the number of clocks, we use the two memories, which are different clock speed for reading and writing data. Second, this system lost the bit-synchronization and frame-synchronization in decoder, the system recognize that all data is error. This paper solves the problems by using simple 5-stage registers and unique sync-word. Based on solutions for about problems, the cable modem is fabricated on FPGA chip name as Vertex II pro xc2vp30-5 by Xilinx, and we confirmed the effectiveness of the results.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.5
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• pp.520-529
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• 2002

Though BIFS is a complex description language that represents MPEG-4 content as text or bit streams, most traditional MPEG-4 content authoring tools are developed for a BIFS expert. Before using these tools, many authors must invest much time and energy in acquiring knowledge of BIFS. In this paper, we suggest a new manner for saving these efforts. Our proposal supplies the convenient user interface of traditional multimedia authoring tools for MPEG-4 authors and interprets the authored information and transforms it into BIFS. In our user interface, the author generates the minimal authoring information requested for generating BIFS; the BIFS generation module then transforms the information into BIFS format using predefined BIFS construction rules. The resulting BIFS consists of the Scene Tree and the Object Descriptor and Route; they are used for constructing MP4 standard files by mixing with the Elementary Stream.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.5
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• pp.837-842
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• 2008

Any errors that are generated in the channels and networks distort the video quality and are propagated in both the spatial and temporal domains. In particular, header errors ran result in serious visual degradation of the output video encoding/decoding schemes that can make an error resilient compressed bit-stream in error prone environments, such as mobile networks. In this paper, we proposes an header error resilience method that consider the activity of macroblock in video bitstream syntex. The extract of header error repaetedly embeds the header parameters into the least significant bits(LSB) of the quantized DCT coefficients prior to VLC. Experimental results show that the proposed error resilience method restores good image quality despite the detected error on header parameters.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.707-715
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• 2008

This paper proposes an algorithm for efficient compression gray-level images by entropy encoder. The issue of the proposed method is to replace original data of gray-level images with particular ranked data. For this, first, before encoding a stream of gray-level values in an image, the proposed method counts co-occurrence frequencies for neighboring pixel values. Then, it replaces each pay value with particularly ranked numbers based on the investigated co-occurrence frequencies. Finally, the ranked numbers are transmitted to an entropy encoder. The proposed method improves the performance of existing entropy coding by transforming original gray-level values into rank based images using statistical co-occurrence frequencies of gray-level images. The simulation results, using gray-level images with 8-bits, show that the proposed method can reduce bit rate by up to 37.85% compared to existing conventional entropy coders.

• Journal of Broadcast Engineering
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• v.24 no.4
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• pp.660-669
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• 2019

Recently, with the development of three-dimensional scanning devices and multi-dimensional array cameras, research is continuously conducted on techniques for handling three-dimensional data in application fields such as AR (Augmented Reality) / VR (Virtual Reality) and autonomous traveling. In particular, in the AR / VR field, content that expresses 3D video as point data has appeared, but this requires a larger amount of data than conventional 2D images. Therefore, in order to serve 3D point cloud content to users, various technological developments such as highly efficient encoding / decoding and storage, transfer, etc. are required. In this paper, V-PCC bit stream created using V-PCC encoder proposed in MPEG-I (MPEG-Immersive) V-PCC (Video based Point Cloud Compression) group, It is defined by the MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard, and provides to be composed of segments. Also, in order to provide the user with the information of the 3D coordinate system, the depth information parameter of the signaling message is additionally defined. Then, we design a verification platform to verify the technology proposed in this paper, and confirm it in terms of the algorithm of the proposed technology.