• Title/Summary/Keyword: Parity

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Construction of Structured q-ary LDPC Codes over Small Fields Using Sliding-Window Method

  • Chen, Haiqiang;Liu, Yunyi;Qin, Tuanfa;Yao, Haitao;Tang, Qiuling
    • Journal of Communications and Networks
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    • v.16 no.5
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    • pp.479-484
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    • 2014
  • In this paper, we consider the construction of cyclic and quasi-cyclic structured q-ary low-density parity-check (LDPC) codes over a designated small field. The construction is performed with a pre-defined sliding-window, which actually executes the regular mapping from original field to the targeted field under certain parameters. Compared to the original codes, the new constructed codes can provide better flexibility in choice of code rate, code length and size of field. The constructed codes over small fields with code length from tenths to hundreds perform well with q-ary sum-product decoding algorithm (QSPA) over the additive white Gaussian noise channel and are comparable to the improved spherepacking bound. These codes may found applications in wireless sensor networks (WSN), where the delay and energy are extremely constrained.

Lactation and Function of Curve Parameters in Yankasa Sheep

  • Afolayan, R.A.;Abubakar, B.Y.;Osinowo, O.A.;Dim, N.I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.6
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    • pp.890-894
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    • 2002
  • The accuracy of the gamma function to describe lactation curve of Yankasa ewes was investigated using milk production data obtained from 168 ewes with either complete or incomplete 84 day lactation records. Ewes were daily hand milked after over-night separation from lamb and thorough disinfection of the udder. The daily milk yield on the average was estimated from the weekly total yield. The effect of type of birth, parity, season of birth and lactation length on the components of lactation curve (a, b, c and s) were analysed by least-square procedures. All factors except parity significantly (p<0.01) influenced the curve parameters. The goodness of fit of the function did not differ between the two classes of varying duration of lactation; incomplete lactation however, showed a lower persistency and as expected lower level of production. Correlations ($r_p$) between lamb weight gain and milk yield using the weight records from lamb weighed at weekly intervals indicated a high and positive relationship in the early lactation that decreased in intensity as the lactation advanced.

A Study of Laser Patterning for $SiO_2$ Thin Film of Crystalline Solar Cells (결정질 태양전지 $SiO_2$ 박막의 Laser Patterning에 관한 연구)

  • Lee, C.S.;Lee, J.C.;Kim, K.S.;Kang, H.S.
    • Laser Solutions
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    • v.14 no.3
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    • pp.1-6
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    • 2011
  • Globally, the interest of renewable energy has become an upsurge. Especially, the solar industry is the one which is getting rapid growth rate. Many of researchers have been undertaking to improve the efficiency of solar cell to accomplish grid parity. The most of research has been concentrated on two methods, one on the selective emitter and the other is on LBSF (Local Back Surface Field) formation. Laser patterning will be needed to eliminate the thin film to form selective emitter and LBSF of solar cell. This paper reports some experimental results in laser patterning process for high-efficiency crystalline solar cell manufacturing. The experimental results indicate that the patterning quality depends on the average power and repetition rate of laser. The experimental results prove that the laser patterning process is an advantageous method to improve the efficiency of solar cell.

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Studies on the Reproductive Performence and Organs Autopsy of Culled Dairy Cow at Alpine Area (고지 사육 도태유우의 번식실태와 생식기 부검에 관한 연구)

  • 이상영;김정익
    • Korean Journal of Animal Reproduction
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    • v.17 no.4
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    • pp.295-303
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    • 1994
  • The present study was conducted to examine the reprodutive performance and organs autopsy of culled dairy cows at alpine area. 795 culled dairy cows were managed and 206 culled dairy cows were examined by autopsy of reproductive organs at above 800m of sea level around the Daegwallryoung alpine area. The results of this study were at follows ; 1. Age and parity of culled dairy cows were 60.8 months and 3.0, respectively. 2. Age of first AI of heifer was 18.7 months, and age of pregnancy and parturition of heifer were 19.5 months and 28.6 months, respectively. 3. Al time per pregnancy was 1.7 and time of pregnancy after parturition, pregnancy period and calving interval were 140.9, 279.6 and 424.9 days, respectively. 4. Culled months after last parturition was 4.3 and the highest urogenital deseases of culled reason were 358(45.0%). 5. Reproductive organs deseases by autopsy were 120(58.4%), the highest ovary disease were 75(43.6%). 6. The highest ovary adhesions of reproductive organ diseases were 46(26.7%), infundibulum adhesion, obstruction of the oviduct and endometritis were 38(22.1%), 15(8.7%), and 14(8.2%), respectively. 7. In culled dairy cow for the reproductive organ disease, parity, age, culled months and AI number after last parturition were 3.2, 66.5 months, 7.9 months and 2.1, respectively.

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Development of a Device for Estimating the Optimal Artificial Insemination Time of Individually Stalled Sows Using Direct-reflex Photo-sensors (직접반사형 포토센서를 이용한 스톨 사육 모돈의 인공수정적기 예측 장치 개발)

  • Kim D. J.;Yeon S. C.;Chang H. H.
    • Journal of Biosystems Engineering
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    • v.29 no.6 s.107
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    • pp.515-520
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    • 2004
  • A device far estimating the optimal artificial insemination time consisted of a computer, RS module, and six direct-reflex photo-sensors. Program was written in LabWindows CVI. In order to establish references for estimating optimal artificial insemination time, lying rate of the thirty three $Berkshire{\times}Hampshire crossbred sows (parity 5 to 6) was recorded from 2 days after moving into stalls to artificial insemination using a time lapse VCR and was measured every hour with one minute interval using the scan point sampling method. Twenty low hours in a day were divided into three comparing periods : 21:00 to 06:59, 07:00 to 13:59, and 14:00 to 20:59. If sum of the percentages of tying during a comparing period was less than the reference value, the starting hour of the comparing period was considered as onset of estrus and the optimal artificial insemination time was estimated at 20 to 24 hours after onset of estrus. The experimental device was evaluated with twenty five $Berkshire{\times}Hampshire$ crossbred sows (parity 2 to 7) and 23 of 25 sows $(92\%)$ were pregnant. This result suggests that the experimental device is excellent in performance for estimating optimal artificial insemination time.

Reliability-Based Iterative Proportionality-logic Decoding of LDPC Codes with Adaptive Decision

  • Sun, Youming;Chen, Haiqiang;Li, Xiangcheng;Luo, Lingshan;Qin, Tuanfa
    • Journal of Communications and Networks
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    • v.17 no.3
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    • pp.213-220
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    • 2015
  • In this paper, we present a reliability-based iterative proportionality-logic decoding algorithm for two classes of structured low-density parity-check (LDPC) codes. The main contributions of this paper include: 1) Syndrome messages instead of extrinsic messages are processed and exchanged between variable nodes and check nodes, which can reduce the decoding complexity; 2) a more flexible decision mechanism is developed in which the decision threshold can be self-adjusted during the iterative process. Such decision mechanism is particularly effective for decoding the majority-logic decodable codes; 3) only part of the variable nodes satisfying the pre-designed criterion are involved for the presented algorithm, which is in the proportionality-logic sense and can further reduce the computational complexity. Simulation results show that, when combined with factor correction techniques and appropriate proportionality parameter, the presented algorithm performs well and can achieve fast decoding convergence rate while maintaining relative low decoding complexity, especially for small quantized levels (3-4 bits). The presented algorithm provides a candidate for those application scenarios where the memory load and the energy consumption are extremely constrained.

SISO-RLL Decoding Algorithm of 17PP Modulation Code for High Density Optical Recording Channel (고밀도 광 기록 채널에서 17PP 변조 부호의 연판정 입력 연판정 출력 런-길이 제한 복호 알고리즘)

  • Lee, Bong-Il;Lee, Jae-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.2C
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    • pp.175-180
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    • 2009
  • When we apply the LDPC code for high density optical storage channel, it is necessary to make an algorithm that the modulation code decoder must feed the LDPC decoder soft-valued information because LDPC decoder exploits soft values using the soft input. Therefore, we propose the soft-input soft-output run-length limited 17PP decoding algorithm and compare performance of LDPC codes. Consequently, we found that the proposed soft-input soft-output decoding algorithm using 17PP is 0.8dB better than the soft-input soft-output decoding algorithm using (1, 7) RLL.

Performance of Noise-Predictive Turbo Equalization for PMR Channel (수직자기기록 채널에서 잡음 예측 터보 등화기의 성능)

  • Kim, Jin-Young;Lee, Jae-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.10C
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    • pp.758-763
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    • 2008
  • We introduce a noise-predictive turbo equalization using noise filter in perpendicular magnetic recording(PMR) channel. The noise filter mitigates the colored noise in high-density PMR channel. In this paper, the channel detectors used are SOVA (Soft Output Viterbi Algorithm) and BCJR algorithm which proposed by Bahl et al., and the outer decoder used is LDPC (Low Density Parity Check) code that is implemented by sum-product algorithm. Two kinds of LDPC codes are experimented. One is the 0.5Kbyte (4336,4096) LDPC code with the code rate of 0.94, and the other is 1Kbyte (8432,8192) LDPC code with the code rate of 0.97.

Herd Management and Control of Dairy Cows by Milk Components in Gyeong-nam (경남지역 유우의 산유능력 검정)

  • You, Yong-sang;Kim Tae-yung;Kim Cheol-ho;Kang Chung-boo
    • Journal of Veterinary Clinics
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    • v.21 no.4
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    • pp.355-362
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    • 2004
  • The purpose of this study was to herd management and control of dairy cows by milk components analysis in Gyeongsangnamdo. Milk components analysis were carried out milk yield (MY), milk fat (MF), milk protein (MP), milk urea nitrogen (MUN) and somatic cell count (SCC) but, milk solid (MS), day of non-pregnant condition (DNPC), and days of primipara (DPRI) involved in report. Dairy farms were divided high group, middle group, low group according to the standard records for milk components. Examination records were divided by farm, parity, year, season and month, the number of samples were 28,957. Feeding management practice and the prediction for the risk possibility of productive disease such as reproductive and metabolic disorders by evaluating fat, protein, solids. Determination of MY, MF, MP, MS were Milkoscan 4,000~5,000 Serier (FOSS Electric Co., Copenhagen, Denmark). Correlation coefficient of milk protein (MP) and milk solid (MS) was ascertain r=0.759. SCC was ascertain 372.8$\pm$11.34 (thousand unit) and DNPC was ascertain 155.3$\pm$5.15 (days) in seven parity.

Optimal Bit Split Methods and Performance Analysis for Applying to Multilevel Modulation of Iterative Codes (반복 부호의 다치 변조방식 적용을 위한 최적의 비트 분리 방법 및 성능평가)

  • Bae, Jong-Tae;Jung, Ji-Won;Choi, Seok-Soon;Kim, Min-Hyuk;Chang, Dae-Ig
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.3C
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    • pp.216-225
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    • 2007
  • This paper presents bit splitting methods to apply multilevel modulation to iterative codes such as turbo code, low density parity check code and turbo product code. Log-likelihood ratio method splits multilevel symbols to bits using the received in-phase and quadrature component based on Gaussian approximation. However it is too complicate to calculate and implement hardware due to exponential and log calculation. therefore this paper presents Euclidean, MAX and Sector method to reduce the high complexity of LLR method. We propose optimal bit splitting method for three iterative codes.