• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1834-1843
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• 2016

DVRs are the most common recording and displaying devices used for surveillance. Video compression plays a key role in DVRs for saving storage; the video compression standard, H.264/AVC, has recently become the dominant choice for DVRs. DVRs require various display modes, such as fast-forward, backward play, and pause; these are called trick modes. The implementation of precise trick mode play requires a very high decoding capability or a very intelligent scheme in order to handle the high computation complexity. The complexity is increased in many surveillance applications where more than one camera is used to monitor multiple spots or to monitor the same area using various angles. An implementation of a trick mode play and a frame buffer management scheme for the hardware-based H.264/AVC codec for multi-channel is presented in this paper. The experimental results show that exact trick mode play is possible using a standard H.264/AVC video codec with keyframe encoding feature at the expense of bitstream size increase.

• Molecules and Cells
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• v.21 no.3
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• pp.418-427
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• 2006

Ionotropic glutamate receptors (iGluRs) are ligand-gated nonselective cation channels that mediate fast excitatory neurotransmission. Although homologues of the iGluRs have been identified in higher plants, their roles are largely unknown. In this work we isolated a full-length cDNA clone (RsGluR) encoding a putative glutamate receptor from small radish. An RsGluR:mGFP fusion protein was localized to the plasma membrane. In Arabidopsis thaliana overexpressing the fulllength cDNA, glutamate treatment triggered greater $Ca^{2+}$ influx in the root cells of transgenic seedlings than in those of the wild type. Transgenic plants exhibited multiple morphological changes such as necrosis at their tips and the margins of developing leaves, dwarf stature with multiple secondary inflorescences, and retarded growth, as previously observed in transgenic Arabidopsis overexpressing AtGluR3.2 [Kim et al. (2001)]. Microarray analysis showed that jasmonic acid (JA)-responsive genes including defensins and JA-biosynthetic genes were up-regulated. RsGluR overexpression also inhibited growth of a necrotic fungal pathogen Botrytis cinerea possibly due to up-regulation of the defensins. Based on these results, we suggest that RsGluR is a glutamate-gated $Ca^{2+}$ channel located in the plasma membrane of higher plants and plays a direct or indirect role in defense against pathogen infection by triggering JA biosynthesis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7A
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• pp.1028-1035
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• 1999

To increase the throughput of data transmission in burst-mode TDMA communication systems and also to get a good BER performance at the same time, it is essential to rapidly acquire the carrier while keeping the desirable tracking performance. To achieve this goal, in this paper, a new decision-directed carrier recovery algorithm is presented. The proposed scheme does not incorporate the PLL and suppress the Gaussian random process of input noise by the pre-stage low pass filter so as to get both the fast acquisition and a good performance. Through computer simulations, the performance of the scheme is analyzed with respect to the acquisition time and bit error rate. The cycle slip in the proposed scheme is seldom observed at very low SNR environment in contrast to the previous proposed one. Because of this merit, it is not required to do the differential encoding and decoding in the proposed scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2C
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• pp.200-208
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• 2009

A macroblock layer rate control for H.264/AVC has the problem that allocated target bits for current frame occasionally are exhausted too fast due to inadequate quantization parameter assignment. In this case, the maximum permissible quantization parameter is used to encode for remaining macroblocks and it leads to degradation of the visual quality. In addition, the header bits length estimation algorithm used for quantization parameter assignment takes the average header bits length for the encoded macroblocks of the previous frame and the current frame. Therefore, it generates a big mismatch between the actually generated header bits length and the estimated header bits length. In this paper, we propose adaptive quantization parameter decision method to prevent early exhausting target bits during encoding the current frame by considering the number of macroblocks that have negative targets bits in previous frame and the improved header bits length estimation scheme for accurate quantization parameter decision.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11C
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• pp.917-924
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• 2008

Motion estimation and compensation in the spatial domain check the searching area of specified size in the previous frame and search block to minimize the difference with current block. When we check the searching area, it consumes the most encoding times due to increasing the complexity. We can solve this fault by means of motion estimation using shifting matrix in the transform domain instead of the spatial domain. We derive so the existed shifting matrix to a new recursion equation that we decrease more computations. We modify simply vertical shifting matrix and horizontal shifting matrix in the transform domain for motion estimation of half-pixel accuracy. So, we solve increasing computation due to bilinear interpolation in the spatial domain. Simulation results prove that motion estimation by the proposed algorithm in DCT-based transform domain provides higher PSNR using fewer bits than results in the spatial domain.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.08a
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• pp.55-67
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• 1999

A puc -deleted cell of Rhodobacter sphaeroides grows with a doubling time longer than 160 h under the light-limiting photoheterotrophic ( 3 Watts [W]/㎡) conditions due to an absence of the peripheral light-harvesting B800-850 complex. A spontaneous fast-growing mutant, R.sphaeroides SK101 was ioslate dto have∼40-h doubling at 3 Watts/㎡, while the growth of the mutant was not distinguished from its parental strain during both aerobic and light-saturating photoheterotrphic (10W/㎡) growth. The B875 complex of SK101 under the light-limiting conditions was elevated by 20 to 30% compared with that of the puc -deleted cell, reflecting parallel increase of bacteriochlorophyll and carotenoid contents of the mutant. The formation of B875 complex of SK101 under the anaerobic dark conditions with dimethylsulfoxide was the same as that of the puc-deleted cell. suggesting that the mutation of SK101 result in the altered control of B875 complex formation by light. When puc is restored in SK101 , it is not B875 complex but B800-850 complex which formation is elevated. The mutation of SK101 affected the bchF transcription most drastically to show two to tenfold increase during both aerobic and photoheterotrophic growth. The mutated phenotype of SK101 was complemented with pW2, which contains approximately 100-kb HNA of the photosynthetic gene clusters. The complementing DNA was narrowed down to a 1.1-kb DNA containing orfQ and pufKBA . The mutation of SK101 appeared to be exerted through the mutation of the orfQ gene encoding a putative bacteriochlorophyll -mobilizing protein.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1405-1409
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• 2004

This paper is studied new block mode decision algorithm for H.264/AVC. The fast block mode decision algorithm is consist of block range decision algorithm. The block range decision algorithm classifies the block over 8$\times$8 size or below for 16${\times}$16 macroblock to decide the size and type of sub blocks. As the sub blocks of 8$\times$8, 8r4, 4$\times$8 and 4$\times$4, which are the blocks below 8$\times$8 size, include important motion information, the exact sub block decision is required. RDC(RDO cost) is used as the matching parameter for the exact sub block decision. RDC is calculated with motion strength which is the mean value of neighbor pixels of each sub block. The sub block range decision reduces encoding arithmetic amount by 34.62% on the average more than the case not using block range decision. The block mode decision using motion strength shows improvement of PSNR of 0.05[dB].

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1256-1261
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• 2005

In this paper, we propose a low-power Booth multiplication which reduces the switching activities of partial products during multiplication process. Radix-4 Booth algorithm has a characteristic that produces the Booth encoded products with zero when input data have sequentially equal values (0 or 1). Therefore, partial products have higher chances of being zero when an input with a smaller effective dynamic range of two multiplication inputs is used as a multiplier data instead of a multiplicand. The proposed multiplier divides a multiplication expression into several multiplication expressions with smaller bits than those of an original input data, and each multiplication is computed independently for the Booth encoding. Finally, the results of each multiplication are added. This means that the proposed multiplier has a higher chance to have zero encoded products so that we can implement a low power multiplier with the smaller switching activity. Implementation results show the proposed multiplier can save maximally about $20\%$ power dissipation than a previous Booth multiplier.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2A
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• pp.204-209
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• 2008

It is the most important in the traffic information system how fast to transmit the traffic conditions on each road, or event such as RTM (Road Traffic Message). In order to operate the event information more efficiently in the TPEG system, it is likely that the effective transmission system shall be needed, and this paper will propose the improved transmission system; Breaking away from the conventional method which is to transmit the traffic information by using simple FIFO method while encoding it into TPEG data, the improved transmission system is to transmit the important information more quickly or to advance the transmission cycle by scheduling according to degree of its importance after deciding which one is the important traffic information by comparing the importance ratings in between diverse information. The traffic information with low importance rating is to be transmitted slowly, and its transmission cycle shall become slow as well. In the computer simulations, it is shown that the proposed approach enables to transmit more quickly a sudden change of traffic conditions and the important traffic data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1C
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• pp.61-72
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• 2005

For the improvement of coding efficiency, the H.264 standard uses new coding tools such as VBS, 1/4-pel accurate ME, multiple references, intra prediction, loop filter, etc. Using these coding tools, H.264 has achieved significant improvements from rate-distortion point of view compared to existing standards. However, the encoder complexity is greatly increased due to these coding tools. We focus on the complexity reduction method of MB mode selection. Among all modes which can be selected, $8{\times}8$ and intra $4{\times}4$ mode have higher complexity than the others. So we propose the methods for reduction of the $8{\times}8$ and intra $4{\times}4$ mode complexity by using information of other modes with relatively low complexity. Simulation results show that the proposed methods save up to $54.6{\%}$ of total encoding time while keeping the average decrease about 0.012dB in PSNR.