• Title/Summary/Keyword: SAD

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Approximate-SAD Circuit for Power-efficient H.264 Video Encoding under Maintaining Output Quality and Compression Efficiency

  • Le, Dinh Trang Dang;Nguyen, Thi My Kieu;Chang, Ik Joon;Kim, Jinsang
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.5
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    • pp.605-614
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    • 2016
  • We develop a novel SAD circuit for power-efficient H.264 encoding, namely a-SAD. Here, some highest-order MSB's are approximated to single MSB. Our theoretical estimations show that our proposed design simultaneously improves performance and power of SAD circuit, achieving good power efficiency. We decide that the optimal number of approximated MSB's is four under 8-bit YUV-420 format, the largest number not to affect video quality and compression-rate in our video experiments. In logic simulations, our a-SAD circuit shows at least 9.3% smaller critical-path delay compared to existing SAD circuits. We compare power dissipation under iso-throughput scenario, where our a-SAD circuit obtains at least 11.6% power saving compared to other designs. We perform same simulations under two- and three-stage pipelined architecture. Here, our a-SAD circuit delivers significant performance (by 13%) and power (by 17% and 15.8% for two and three stages respectively) improvements.

Seasonal Variations of Mood and Behavior in Korean Medical Students (한국의 의과대학생에서 기분과 행동의 계절적 변동)

  • Kim, Sung-Jae;Lee, Heon-Jeong;Choi, Hyun-Seok;Jung, Hyun-Gang;Kim, Bong-Ju;Kim, Ju-Yeon;Lee, Young-Woo;Cho, Dong-Hyuk;Lee, Min-Soo;Joe, Sook-Haeng;Kim, Leen
    • Sleep Medicine and Psychophysiology
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    • v.11 no.2
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    • pp.95-99
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    • 2004
  • Objectives: Although many studies on seasonal variations in mood and behavior have been carried out in foreign countries, no such study has previously been undertaken in Korea. The goal of this study was to estimate the frequency of seasonal variations in mood and behavior among Korean medical students. Methods: 297 medical students from Korea University College of Medicine participated in this study. The subjects were surveyed with a Korean translation of the Seasonal Pattern Assessment Questionnaire (SPAQ), and their responses were evaluated for seasonal patterns of mood and behavioral change, including seasonal affective disorder (SAD) and subsyndromal seasonal affective disorder (S-SAD), derived from the case-finding criteria of Kasper et al. Results: The mean global seasonality score was 6.6 (SD=3.6). 83.5% (N=248) of the subjects reported some changes in behavior and mood associated with the seasons. Only 3.7% (N=11) reported no behavioral changes across the seasons. Total prevalence rates were 15.2% for SAD, and 2.7% for S-SAD. The estimated frequencies were 3.0% for summer SAD, 2.7% for summer S-SAD, 11.4% for winter SAD, and 5.8% for winter S-SAD. The prevalence rates for winter SAD or S-SAD were higher than the prevalence rates for summer SAD or S-SAD. Conclusion: These results suggest that seasonal variations in mood and behavior are common among Koreans. The higher prevalence rate of winter SAD or S-SAD than summer SAD or S-SAD is consistent with most western studies and stands in contrasts to studies in other Asian countries, such as Japan and China.

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Implemenation of an ASIP for acceleration SAD operation (SAD 연산의 가속을 위한 멀티미디어 코프로세서 구현)

  • Jo, Jung-Hyun;Jeong, Ha-Young
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.809-810
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    • 2006
  • An H.264 algorithm is commonly used for video compression applications. This algorithm requires a large number of data computations, for example, the sum of absolute difference (SAD) operation. We analyzed H.264 reference encoding workloads. The H.264 encoding program has 8.78% SAD operation. The SAD operation is to sum up 16 difference-values in H.264 $4{\times}4$ sub-blocks. In order to accelerate SAD operations, we implemented an application specific instruction-set processor (ASIP) that can execute SAD and data transfer instructions. The proposed coprocessor has an absolute value generator and a carry save adder (CSA) unit to sum up 8 difference-values per one clock cycle. We completed SAD operation in 2 clock cycles. Experimental results show that the performance is improved by 34% of total execution time.

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Molecular dissection of OsSAD1 conferring salt-, ABA- and drought stresses in rice

  • Park, Yong Chan;Jang, Cheol Seong
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.149-149
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    • 2017
  • The RING (Really Interesting New Gene) finger proteins are known to play crucial roles in various abiotic stresses in plants. In this study, we report on RING finger E3 ligase, ${\underline{O}ryza}$ ${\underline{s}ativa}$ ${\underline{s}alt$-, ${\underline{A}BA}$- and ${\underline{d}rounght}$ stress-${\underline{i}nduced}$ RING finger ${\underline{p}}rotein{\underline{1}}$ gene (OsSAD1). In vitro ubiquitination assay demonstrated that unlike OsSAD1, a single amino acid substitution ($OsSAD1^{C168A}$) of the RING domain showed no E3 ligase activity, supporting the notion that the activity of most E3s is specified by a RING domain. Result of Yeast-Two hybridization, In vivo protein degradation assay supports that OsSAD1 interacting with 3 substrate, OsSNAC2, OsGRAS44 and OsPIRIN1, and mediates proteolysis of 3 substrates via the 26S proteasome pathway. Subcellular localizations of OsSAD1 while approximately 62% of transient signals were detected in cytosol, 38% of signals were showed nucleus. However, transiently expression of OsSAD1 was detected in cytosol 30% while as 70% of nucleus under 200 mM salt treated rice protoplasts. Results of bimolecular fluorescence complementation (BiFC) showed that two nucleus-localized proteins (OsSNAC2 and OsGRAS44) interacted with OsSAD1 in the both cytosol and nucleus. Heterogeneous overexpression of OsSAD1 Heterogeneous overexpresssion of OsSAD1 in Arabidopsis exhibited sensitive phenotypes with respect to Salt-, mannitol-responsive seed germination, seedling growth. In ABA conditions, OsSAD1 overexpression plants showed highly tolerance phenotypes, such as root length and stomatal closure. Our findings suggest that the OsSAD1 may play a negative regulator in salt stress response by modulating levels of its target proteins.

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A Fast SAD Algorithm for Area-based Stereo Matching Methods (영역기반 스테레오 영상 정합을 위한 고속 SAD 알고리즘)

  • Lee, Woo-Young;Kim, Cheong Ghil
    • Journal of Satellite, Information and Communications
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    • v.7 no.2
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    • pp.8-12
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    • 2012
  • Area-based stereo matchng algorithms are widely used for image analysis for stereo vision. SAD (Sum of Absolute Difference) algorithm is one of well known area-based stereo matchng algorithms with the characteristics of data intensive computing application. Therefore, it requires very high computation capabilities and its processing speed becomes very slow with software realization. This paper proposes a fast SAD algorithm utilizing SSE (Streaming SIMD Extensions) instructions based on SIMD (Single Instruction Multiple Data) parallism. CPU supporing SSE instructions has 16 XMM registers with 128 bits. For the performance evaluation of the proposed scheme, we compare the processing speed between SAD with/without SSE instructions. The proposed scheme achieves four times performance improvement over the general SAD, which shows the possibility of the software realization of real time SAD algorithm.

Seasonal Variations in Mood and Behavior in Korean High School Students (한국의 고등학생에서 기분과 행동의 계절적 변동)

  • Lee, Moon-Soo;Joung, Yoo-Sook;Hong, Sung-do-David;Ko, Young-Hoon;Kim, Seung-Hyun;Joe, Sook-Haeng;Jung, In-Kwa;Kim, Leen;Lee, Heon-Jeong
    • Sleep Medicine and Psychophysiology
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    • v.12 no.2
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    • pp.111-116
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    • 2005
  • Objectives: Although many reports have been written on seasonal variations in mood and behavior in foreign countries, few reports have dealt with Korean adolescents, except medical students. The goal of this study was to estimate the frequency of seasonal variations in mood and behavior among Korean high school students. Methods: A total of 656 high school students living in southeastern Seoul participated in this study. The subjects were investigated with the Korean translated version of the Seasonal Pattern Assessment Questionnaire (SPAQ), and their responses were evaluated for seasonal patterns in mood and behavior change according to Kasper's criteria to make SAD (seasonal affective disorder) or SSAD (subclinical seasonal affective disorder) diagnosis. Results: A total of 565 subjects completed the questionnaire and the responses (M:F=324:241) were collected and used for analysis. The mean age was 16.73 (SD=0.65) years, and mean global seasonality score 5.88 (SD=4.72). Of the respondents, 413 (73.1%) reported problems related with seasonal changes. Total prevalence rates were 13.6% for SAD, 10.8% for S-SAD. The estimated frequencies were 5.1% for summer SAD, 3.2% for summer S-SAD, 0.5% for winter SAD and 1.1% for winter S-SAD. The prevalence rate of summer SAD or S-SAD was higher than winter SAD or S-SAD. Conclusion: The subjects showed a higher prevalence rate of summer type than winter type in SAD or S-SAD. These results were similar to those of other studies carried out in East Asian countries. However, the unpleasant feelings resulting from high temperature and humidity in summer rather than depression may have influenced the results. Therefore, it is necessary to make new SAD criteria of the SPAQ suitable for East Asian countries.

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Optimal Scheduling of SAD Algorithm on VLIW-Based High Performance DSP (VLIW 기반 고성능 DSP에서의 SAD 알고리즘 최적화 스케줄링)

  • Yu, Hui-Jae;Jung, Sou-Hwan;Chung, Sun-Tae
    • The Journal of the Korea Contents Association
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    • v.7 no.12
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    • pp.262-272
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    • 2007
  • SAD (Sum of Absolute Difference) algorithm is the most frequently executing routine in motion estimation, which is the most demanding process in motion picture encoding. To enhance the performance of motion picture encoding on a VLIW processor, an optimal implementation of SAD algorithm on VLIW processor should be accomplished. In this paper, we propose an implementation of optimal scheduling of SAD algorithm with conditional branch on a VLIW-based high performance DSP. We first transform the nested loop with conditional branch of SAD algorithm into a single loop with conditional branch which has a large enough loop body to utilize fully the ILP capability of VLIW DSP and has a conditional branch to make the escape from loop to be achieved as soon as possible. And then we apply a modulo scheduling technique to the transformed single loop. We test the proposed implementation on TMS320C6713, and analyze the code size and performance with respect to processing time. Through experiments, it is shown that the SAD implementation proposed in this paper has small code size appropriate for embedded applications, and the H.263 encoder with the proposed SAD implementation performs better than other H.263 encoder with other SAD implementations.

Efficient SAD Processor for Motion Estimation of H.264 (H.264 움직임 추정을 위한 효율적인 SAD 프로세서)

  • Jang, Young-Beom;Oh, Se-Man;Kim, Bee-Chul;Yoo, Hyeon-Joong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.2 s.314
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    • pp.74-81
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    • 2007
  • In this paper, an efficient SAD(Sum of Absolute Differences) processor structure for motion estimation of H.264 is proposed. SAD processors are commonly used both in full search methods for motion estimation and in fast search methods for motion estimation. Proposed structure consists of SAD calculator block, combinator block, and minimum value calculator block. Especially, proposed structure is simplified by using Distributed Arithmetic for addition operation. The Verilog-HDL(Hard Description Language) coding and FPGA(Field Programmable Gate Array) implementation results for the proposed structure show 39% and 32% gate count reduction in comparison with those of the conventional structure, respectively. Due to its efficient processing scheme, the proposed SAD processor structure can be widely used in size dominant H.264 chip.

A Fast Search Algorithm for Sub-Pixel Motion Estimation (부화소 움직임 추정을 위한 고속 탐색 기법)

  • Park, Dong-Kyun;Jo, Seong-Hyeon;Cho, Hyo-Moon;Lee, Jong-Hwa
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.26-28
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    • 2007
  • The motion estimation is the most important technique in the image compression of the video standards. In the case of next generation standards in the video codec as H.264, a high compression-efficiency can be also obtained by using a motion compensation. To obtain the accurate motion search, a motion estimation should be achieved up to 1/2 pixel and 1/4 pixel uiuts. To do this, the computational complexity is increased although the image compression rate is increased. Therefore, in this paper, we propose the advanced sub-pixel block matching algorithm to reduce the computational complexity by using a statistical characteristics of SAD(Sum of Absolute Difference). Generally, the probability of the minimum SAD values is high when searching point is in the distance 1 from the reference point. Thus, we reduced the searching area and then we can overcome the computational complexity problem. The main concept of proposed algorithm, which based on TSS(Three Step Search) method, first we find three minimum SAD points which is in integer distance unit, and then, in second step, the optimal point is in 1/2 pixel unit either between the most minimum SAD value point and the second minimum SAD point or between the most minimum SAD value point and the third minimum SAD point In third step, after finding the smallest SAD value between two SAD values on 1/2 pixel unit, the final optimized point is between the most minimum SAD value and the result value of the third step, in 1/2 pixel unit i.e., 1/4 pixel unit in totally. The conventional TSS method needs an eight.. search points in the sub-pixel steps in 1/2 pixel unit and also an eight search points in 1/4 pixel, to detect the optimal point. However, in proposed algorithm, only total five search points are needed. In the result. 23 % improvement of processing speed is obtained.

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Modified 3-step Search Motion Estimation Algorithm for Effective Early Termination (효과적인 조기 중단 기법을 위한 변형된 3단계 탐색 움직임 추정 알고리즘)

  • Yang, Hyeon-Cheol;Lee, Seong-Soo
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.7
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    • pp.70-77
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    • 2010
  • Motion estimation occupies most of the required computation in video compression, and many fast search algorithms were propsoed to reduce huge computation. SAD (sum-of-absolute difference) calculation is the most computation-intensive process in the motion estimation. Early termination is widely used in SAD calculation, where SAD calculation is terminated and it proceeds to next search position if partial SAD during SAD calculation exceeds current minimum SAD. In this paper, we proposed a modified 3-step search algorithm for effective early termination where only search order of search positions are adaptive rearranged. Simulation results show that the proposed motion estimation algorithm reduces computation by 17~30% over conventional 3-step search algorithm without extra computation, while maintaining same performance.