• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.832-841
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• 2007

Rectal Temperature;Thermoregulation;Sows;Breed;The effects of season (hot vs. warm) in a tropical humid climate, parity (primiparous vs. multiparous) and breed (Creole: CR, Large White: LW) on rectal temperature (RT) were studied for a total of 222 lactations obtained in 85 sows (43 CR and 42 LW; 56 primiparous and 166 multiparous) over a 28-d lactation, between June 2002 and April 2005. Mean daily ambient temperature was higher during the hot season than during the warm season (26.0 vs. $24.1^{\circ}C$) and relative humidity was high and similar in both seasons (89% on average). At farrowing, BW was lower (172 vs. 233 kg) and backfat thickness was higher (37 vs. 21 mm) in CR than in LW sows (p<0.01). During the hot season, the reduction of average daily feed intake (ADFI) was more pronounced in LW than in CR sows (-920 vs. -480 g/d, p<0.05). Rectal temperature was higher at 1200 than at 0700hr, which coincides with the maximum and the minimum values of daily ambient temperature. The daily RT increased ($+0.9^{\circ}C$; p<0.01) between d -3 and d 7 (d 0: farrowing day), remained constant between d 7 and d 25 and decreased (p<0.01) thereafter (i.e. $-0.6^{\circ}C$ between d 25 and d 32). The average daily RT was significantly higher during the hot than during the warm season (38.9 vs. $38.6^{\circ}C$; p<0.01). It was not affected by breed, but the difference in RT between the hot and warm seasons was more pronounced in LW than in CR sows (+0.4 vs. $+0.2^{\circ}C$; p<0.05). Parity influenced the RT response; it was greater in primiparous than in multiparous sows (38.9 vs. $38.7^{\circ}C$; p<0.01). This study suggests that thermoregulatory responses to heat stress can differ between breeds and between parities.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.722-725
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• 2010

In this paper, BER performance and error convergence speed of layered LDPC(Low Density Parity Check) decoder which supports IEEE 802.16e WiMAX standard is analyzed, and optimal design conditions for hardware implementation are derived. A LDPC decoder is modeled and simulated at AWGN channel with QPSK modulation by Matlab. The parity check matrix(PCM) for IEEE 802.16e standard which has block lengths of 576, 1440, 2304 and code rates of 1/2, 2/3A, 2/3B, 3/4A, 3/4B, 5/6 are used. Fixed-point simulation results show that fixed-point bit-width should be more than 8 bits for acceptable decoding performance.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.68-73
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• 2007

Recently, WSN(wireless sensor networks) consists of several sensor nodes in sensor field. And each sensors have the enforced energy constraint. Therefore, it is important to manage energy efficiently. In WSN application system, FEC(Forward error correction) increases the energy efficiency and data reliability of the data transmission. LDPC(Low density parity check) code is one of the FEC code. It needs more encoding operation than other FEC code by growing codeword length. But this code can approach the Shannon capacity limit and it is also can be used to increase the data reliability and decrease the transmission energy. In this paper, the author adopt Linear-Congruence method at generating parity check matrix of LDPC(Low density parity check) codes to reduce the complexity of encoding process and to enhance the energy efficiency in the WSN. As a result, the proposed algorithm can increase the encoding energy efficiency and the data reliability.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.752-759
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• 2010

In this paper, we propose differential-logging method to improve the performance of RMW(Read Modify Write) operations of DDR-SSD based software RAID. Small writes that are frequently occurred in enterprise applications are main factor to degrade the performance of RAID5. Once a block is updated in RAID5, the parity block of the block must be updated to maintain consistency of parity. Therefore, to process a small write request, we need to read its parity block stored in disk, read old data, perform XOR operation, and write updated data and parity block. Several methods for hard disk based software RAID are proposed to solve the small write problems in RAID 5. Ln this paper, we propose a differential-logging method which carefully considers the DDR-SSD to solve the small write problem in RAID 5. We show that our proposed method out performs the existing software RAID in LINUX through simulations.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1516-1519
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• 2001

The data consisted of 369 lactation records for calvings over a sixteen-year period (1972-1987) and included only cows that had normal milk records. The data were analysed using a linear model containing the fixed effects of parity, year of calving and season of calving. The least squares means${\pm}$S.E. were $1,273{\pm}58.4kg$ for milk yield, and for post-partum body weight (kg) at 2, 3 and 4 months after calving were $343.40{\pm}3.96$, $346.10{\pm}4.10$ and $352.54{\pm}4.26$, respectively. With the exception of season of calving, the effects of parity and year of calving were significant (p<0.01) on the performance of the animals. Thus, the mean-milk yields 1162, 1351 and 1350, were similar for pre-, peak- and post rainy seasons, respectively. On the other hand, as parity increased from 1 to 3, milk yield also increased, but thereafter, there was a gradual decline in milk yield. Similarly, post-partum body weight also increased with parity. However, no consistent pattern for year effect was observed which probably was a reflection of the variation in climatic conditions, or forage quality and/or availability. The phenotypic correlations between milk yield and post-partum body weights were negative and small (ranging from -0.01 to -0.08). However, high milk production in cows was associated with longer calving interval. The implications from the phenotypic correlations are suggestive of one or two possibilities. Firstly, selection for increased body weight may actually result in decreased milk yield. Also, a substantial genetic antagonism may exist between milk yield and fertility in the crossbred cows. Therefore, it is important that selection to improve milk production should take into consideration the reproductive performance of the cows.

• Journal of Communications and Networks
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• v.17 no.4
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• pp.351-361
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• 2015

In this paper, a new decoding scheme is proposed to improve the error correcting performance of low-density parity-check (LDPC) codes in high signal-to-noise ratio (SNR) region by using post-processing. It behaves as follows: First, a conventional LDPC decoding is applied to received LDPC codewords one by one. Then, we count the number of word errors in a predetermined number of decoded codewords. If there is no word error, nothing needs to be done and we can move to the next group of codewords with no delay. Otherwise, we perform a proper post-processing which produces a new soft-valued codeword (this will be fully explained in the main body of this paper) and then apply the conventional LDPC decoding to it again to recover the unsuccessfully decoded codewords. For the proposed decoding scheme, we adopt a simple product code structure which contains LDPC codes and simple algebraic codes as its horizontal and vertical codes, respectively. The decoding capability of the proposed decoding scheme is defined and analyzed using the parity-check matrices of vertical codes and, especially, the combined-decodability is derived for the case of single parity-check (SPC) codes and Hamming codes used as vertical codes. It is also shown that the proposed decoding scheme achieves much better error correcting capability in high SNR region with little additional decoding complexity, compared with the conventional LDPC decoding scheme.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.4
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• pp.479-484
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• 2004

The study was conducted to assess the effect of milk production, parity, stage of lactation, season and individual milk components themselves on milk urea nitrogen (MUN) concentration and other milk components of 3,219 Holstein dairy cows in Korean dairy farms. The MUN concentrations in Korean dairy cows were estimated to 16.68$\pm$5.87 mg/dl. Milk yield was negatively correlated with fat and protein contents and somatic cell counts (SCC) in milk (p<0.01). The increasing MUN concentration has positive correlation with yield and fat content. By increasing somatic cell, milk yield was reduced and MUN level was increased. Cows in spring and winter produced more milk over 1.43 and 0.93 kg/day, respectively, than cows in summer (p<0.01). Milk urea nitrogen concentrations of milk produced in summer and fall were significantly lower (p<0.01) than those in spring and winter. Both MUN concentration and somatic cell counts were highest in winter. Milk yield was lower (p<0.01) in the first calving than other calving time and was tended to increase until the fifth parity and then decrease. Milk urea nitrogen and SCC were not related to parity of cows in this study. Milk yield and SCC were positively related to lactation period while MUN concentrations and milk fat and protein contents were negatively influenced by stage of lactation. In the present study, the relationship between MUN and reproduction of dairy cows was also investigated. Cow produced milk in high MUN concentrations (greater than 18 mg/dl) had more open days than cows in MUN concentrations less than 18 mg/dl. However, no significant difference between MUN concentration levels and frequency of artificial insemination was found in this study. It is suggested that although MUN values for nutritional management and measures of production or reproduction are used, non-nutritional factors should be considered.

• Journal of Energy Engineering
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• v.16 no.1 s.49
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• pp.46-52
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• 2007

The piecewise constant angular approximation is developed to replace the conventional angular quadrature sets in the solution of the second-order, multi-dimensional $S_{N}$ neutron transport equations. The newly generated quadrature sets by this method substantially mitigate ray effects and can be used in the same manner as the conventional quadrature sets are used. The discrete-ordinates and the piecewise-constant approximations are applied to both the first-order Boltzmann and the second-order form of neutron transport equations in treating angular variables. The result is that the mitigation of ray effects is only achieved by the piecewise-constant method, in which new angular quadratures are generated by integrating angle variables over the specified region. In other sense, the newly generated angular quadratures turn out to decrease the contribution of mixed-derivative terms in the even-parity equation that is one of the second-order neutron transport equation. This result can be interpreted as the entire elimination or substantial mitigation of ray effect are possible in the simplified even-parity equation which has no mixed-derivative terms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.9
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• pp.744-749
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• 2013

We propose soft user data input on LDPC codes with parity encoded by the (1, 7) run length limited (RLL) code for perpendicular magnetic recording channel. The user data are encoded by maximum transition run (MTR) (3;11) code. In order to minimize the loss of code rate, the (1, 7) RLL code only encode the parity of LDPC. Also, to increase performance, we propose only user data part applied soft output Viterbi algorithm (SOVA). The performance using the SOVA showed good performance lower than 26 dB. In contrast, it showed worse performance high than 26 dB. This is because of incorrect soft information by high jitter noise and two different input types for LDPC decoder.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.771-774
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• 2010

In this paper, BER performance of LDPC(Low-Density Parity-Check) decoder for WiMAX is analyzed, and optimal design conditions of LDPC decoder are derived. The min-sum LDPC decoding algorithm which is based on an approximation of LLR sum-product algorithm is modeled and simulated by Matlab, and it is analyzed that the effects of LLR approximation bit-width and maximum iteration cycles on the bit error rate(BER) performance of LDCP decoder. The parity check matrix for IEEE 802.16e standard which has block length of 2304 and code rate of 1/2 is used, and AWGN channel with QPSK modulation is assumed. The simulation results show that optimal BER performance is achieved for 7 iteration cycles and LLR bit-width of (8,6).