• Asian-Australasian Journal of Animal Sciences
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• 제6권4호
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• pp.497-507
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• 1993

Four truncation selection schemes (SSs) were framed to predict and compare the age structures and genetic responses under the influence of various factor employing the scheme-specific algorithms. Two paths of selection, sires (bulls' sires) and dams (bulls' dams) to breed young bulls were considered. Among variable factors, four levels (0.3, 0.5, 0.7, 0.9) of precision of evaluation, five levels (0.0, 0.05, 0.10, 0.15, 0.20 genetic standard deviation) of genetic differences among age classes and 4 levels of proportions selected (for bulls' sire, 0.05, 0.10, 0.125, 0.25, and for bulls' dams 0.02, 0.04, 0.05, and 0.10) contemplated on both paths of selection. The number of age classes for bulls' dams and bulls' sires were 4 or 8 and 2 or 4, respectively. The stayability across age classes for bulls' dams was assumed to be 0.80 or 0.60. The candidates for selection for bulls' sires were equally distributed (0.5 or 0.25) across the age classes. The SS1 (selection on same proportions as candidates' distribution) revealed longest generation lengths and lowest yearly genetic responses. The average ages were youngest and yearly genetic responses were highest in SS4 (selection at each age-specific truncation point with the same average genetic superiority of selected parents across the ages) and followed by SS3 (selection at each agespecific truncation point with same predicted genetic values) and SS2 (selection at common truncation point on phenotypic values) in a population with overlapping generations. The results revealed the importance of choosing suitable selection scheme to acquire maximum yearly genetic responses especially when the genetic differences among age classes are large and the precision of evaluation is relatively low.

• Communications for Statistical Applications and Methods
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• 제17권6호
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• pp.811-827
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• 2010

본 논문에서는 통계적 역문제로서 이항 선택모형에서의 밀도추정 방법에 대하여 연구하였다. 밀도함수의 추정을 위하여 직교열 기저를 이용하였으며, 모형의 복잡성과 예측의 정확성을 반영한 적절한 절단모수의 선택에 대하여 고려하였다. 이항 선택 모형에서 데이터에 의존하는 절단모수를 선택하는 방법에 대해 제안하고 모의실험, 실자료를 통해 제안한 방법의 성능을 규명하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권2호
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• pp.485-499
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• 2021

Although non-binary low-density parity-check (NB-LDPC) codes have better error-correction capability than that of binary LDPC codes, their decoding complexity is significantly higher. Therefore, it is crucial to reduce the decoding complexity of NB-LDPC while maintaining their error-correction capability to adopt them for various applications. The extended min-sum (EMS) algorithm is widely used for decoding NB-LDPC codes, and it reduces the complexity of check node (CN) operations via message truncation. Herein, we propose a low-cost CN processing method to reduce the complexity of CN operations, which take most of the decoding time. Unlike existing studies on low complexity CN operations, the proposed method employs quick selection algorithm, thereby reducing the hardware complexity and CN operation time. The experimental results show that the proposed selection-based CN operation is more than three times faster and achieves better error-correction performance than the conventional EMS algorithm.

• Asian-Australasian Journal of Animal Sciences
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• 제21권11호
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• pp.1559-1571
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• 2008

A rule was developed to constrain the annual rate of inbreeding to a predefined value in a population with different lifetimes between sires and dams, and to maximize the selection response over generations. This rule considers that the animals in a population should be divided into sex-age classes based on the theory of gene flow, and restricts the increase of average inbreeding coefficient for new offspring by limiting the increase of the mean additive genetic relationship for parents selected. The optimization problem of this rule was formulated as a quadratic programming problem. Inputs for the rule were the BLUP estimated breeding values, the additive genetic relationship matrix of all animals, and the long-term contributions of sex-age classes. Outputs were optimal number and contributions of selected animals. In addition, this rule was combined with the optimization of emphasis given to QTL, and further increased the genetic gain over the planning horizon. Stochastic simulations of closed nucleus schemes for pigs were used to investigate the potential advantages obtained from this rule by combining the standard QTL selection, optimal QTL selection and conventional BLUP selection. Results showed that the predefined rates of inbreeding were actually achieved by this rule in three selection strategies. The rule obtained up to 9.23% extra genetic gain over truncation selection at the same rates of inbreeding. The combination of the extended rule and the optimization of emphasis given to QTL allowed substantial increases in selection response at a fixed annual rate of inbreeding, and solved substantially the conflict between short-term and long-term selection response in QTL-assisted selection schemes.

• Investigative Magnetic Resonance Imaging
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• 제20권1호
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• pp.27-35
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• 2016

Purpose: Among RF pulses, a sinc pulse is typically used for slice selection due to its frequency-selective feature. When a sinc pulse is implemented in practice, it needs to be apodized to avoid truncation artifacts at the expense of broadening the transition region of the excited-band profile. Here a sinc pulse tailored by a new apodization function is proposed that produces a sharper transition region with well suppression of truncation artifacts in comparison with conventional tailored sinc pulses. A multiband pulse designed using this newly apodized sinc pulse is also suggested inheriting the better performance of the newly apodized sinc pulse. Materials and Methods: A new apodization function is introduced to taper a sinc pulse, playing a role to slightly shift the first zero-crossing of a tailored sinc pulse from the peak of the main lobe and thereby producing a narrower bandwidth as well as a sharper pass-band in the excitation profile. The newly apodized sinc pulse was also utilized to design a multiband pulse which inherits the performance of its constituent. Performances of the proposed sinc pulse and the multiband pulse generated with it were demonstrated by Bloch simulation and phantom imaging. Results: In both simulations and experiments, the newly apodized sinc pulse yielded a narrower bandwidth and a sharper transition of the pass-band profile with a desirable degree of side-lobe suppression than the commonly used Hanning-windowed sinc pulse. The multiband pulse designed using the newly apodized sinc pulse also showed the better performance in multi-slice excitation than the one designed with the Hanning-windowed sinc pulse. Conclusion: The new tailored sinc pulse proposed here provides a better performance in slice (or slab) selection than conventional tailored sinc pulses. Thanks to the availability of analytical expression, it can also be utilized for multiband pulse design with great flexibility and readiness in implementation, transferring its better performance.

• 한국도서관정보학회지
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• 제35권1호
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• pp.303-317
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• 2004

The purpose of this study was to develop a framework for predicting searching performance through an understanding of how cognitive ability relates to searching process and outcome. Specifically, this study examined the relationship between spatial visualization, logical reasoning, integrative reasoning, and information searching process and outcome. Information searching process was assessed by seven search process indicators: (1) search command selection: (2) combination of search commands; (3) application of Boolean logic: (4) application of truncation; (5) use of limit search function; (6) number of search statements; and (7) number of search errors made. Searching outcome was assessed by the number of correct answers to search questions. Subjects first took three standardized cognitive tests that measured cognitive abilities, and performed online catalog searching in response to seven information search questions. The searches were logged using Lotus ScreenCam, and reviewed for the analysis. Factor analysis was used to find underlying structures of the seven search process variables. Multiple regression analysis was applied to examine the predictive power of three cognitive variables on three extracted factors, and search outcome. Results of the data analysis showed that individual differences in logical reasoning could predict information searching process and outcome.

• 융합신호처리학회논문지
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• 제6권3호
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• pp.107-111
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• 2005

멀티미디어 사용의 증가에 따라 정보화 사회에 있어 정지영상 정보를 높은 압축율로 방대한 데이터를 얼마나 빠르게 에러 없이 전송 또는 처리하는가 하는 문제가 요구되어지고 있다. 본 논문은 임베디드 시스템 환경의 정지영상 인코팅 분야에서 다양한 기능과 압축 성능을 보이고 있는 JPEG2000의 압축효율 향상을 위하여 양자화 전 단계에서 추출데이터를 축소시켜 EBCOT 단계로 전달되는 데이터의 양을 줄이는 방법으로, 웨이블렛 계수의 저주파 대역에 대한 부호화를 제거하여 부호화 과정에서의 sign bit를 줄이고, 중요도 판별과정에서 각 단계별 임계치를 설정하여 중복비트를 제거하는 분할 정렬 알고리즘을 이용하여 웨이블렛 계수를 줄이는 방법을 제안하였다. 실험결과, 제안한 방법을 통해 임베디드 환경아래에서 기존의 JPEG2000 표준보다 더 우수한 양질의 성능과 저 비트율을 확인할 수 있었다.

• 한국육종학회지
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• 제40권3호
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• pp.263-268
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• 2008

잣나무 채종원의 유전간벌을 위하여 재적생장에 대한 개량 효과와 유효클론수를 이용한 유전다양성을 평가하였다. 유전 간벌은 클론의 일반조합능력으로 나타나는 육종가(breeding value), 암꽃과 수꽃 개화량을 이용한 종자생산 기여도, 클론별 ramet수 등를 이용한 클론별 변이를 기초로 하였다. 차대 검정 결과에 의하여 산출된 재적생장에 대한 클론별 일반조합능력(genetic value) 및 1991년부터 2003년까지 조사된 개화량 성적을 이용하여 잣나무 채종원(1981년 조성) 179클론에 대하여 간벌 강도에 따른 유전다양성 및 개량효과를 분석하였다. 이때 채종원 외부로부터의 화분오염율은 30%(gene migration = 15%)로 설정하였다. 그 결과 재적생장에 대한 개량효과는 간벌율이 10%에서 60%까지 높아짐에 따라서 점차 증가하였다. 하지만 이보다 더 높은 간벌 강도에서 현저한 개량효과 증가는 나타나지 않았다. 유효클론수는 간벌강도 10%에서 60% 사이에서는 40클론으로 나타났으며, 70% 간벌율 이상에서는 증가하거나 감소하는 변동을 나타냈다. 따라서 본 잣나무 채종원에 대해서는 50%에서 60% 수준의 간벌 강도가 적당한 것으로 판단된다.