• Title/Summary/Keyword: xSelection

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Fast Algorithms for Computing Floating-Point Reciprocal Cube Root Functions

  • Leonid Moroz;Volodymyr Samotyy;Cezary Walczyk
    • International Journal of Computer Science & Network Security
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    • v.23 no.6
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    • pp.84-90
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    • 2023
  • In this article the problem of computing floating-point reciprocal cube root functions is considered. Our new algorithms for this task decrease the number of arithmetic operations used for computing $1/{\sqrt[3]{x}}$. A new approach for selection of magic constants is presented in order to minimize the computation time for reciprocal cube roots of arguments with movable decimal point. The underlying theory enables partitioning of the base argument range x∈[1,8) into 3 segments, what in turn increases accuracy of initial function approximation and decreases the number of iterations to one. Three best algorithms were implemented and carefully tested on 32-bit microcontroller with ARM core. Their custom C implementations were favourable compared with the algorithm based on cbrtf(x) function taken from C <math.h> library on three different hardware platforms. As a result, the new fast approximation algorithm for the function $1/{\sqrt[3]{x}}$ was determined that outperforms all other algorithms in terms of computation time and cycle count.

Selection Efficiency for Protein Content and Sedimentation Value in Progenies of Hybridized Wheat (밀 잡종 후기 세대에서 단백질 함량 및 경, 연질의 선발 효과)

  • 송현숙;이홍석
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.38 no.1
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    • pp.8-14
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    • 1993
  • To investigate selection efficiency for protein content and hardness in a wheat breeding program, two crosses were made between soft wheat (SW) ‘Chokwang’ and hard wheat (HW) ‘Lancota’, and between HW ‘Suwon 210’ and SW ‘Atlas 66’. F2 progeny lines from the crosses were separated into 4 groups as HW + high protein (HP), HW + low protein (LP), SW + HP and SW + LP by measuring protein content and sedimentation value in F4 generation. The subsequent populations were tested for protein content, sedimentation value, mixogram pattern and bread quality. HP group selected from F4 again had a higher protein content in F5 generation than LP group, but there was no significant difference between two groups in F6 generation. In sedimentation value, the significant difference was recognizable only between the groups of HW + HP and. SW + LP. Plant based investigation in F6 revealed that the distribution pattern for protein content and sedimentation value shifted from the low to high by the four groups with the order of SW + LP, HW + LP, SW + HP, HW + HP. Such a trend was most noticeable in the progenies of the cross between ‘Suwon 210’ and ‘Atlas 66’. Mixogram pattern that shows flour characteristics differed greatly among the groups, indicating a high selection efficiency for the traits. Bread volume in F6 of HW + HP was found to be higher than that of SW + LP, only from the cross between ‘Suwon 210’ and ‘Atlas 66’.

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Development of the Multi Band Transceiver for Multi-Channel SAR (다채널 영상레이다를 위한 다중대역 송수신기 개발)

  • Kim, Jae-Min;Lim, Jae-Hwan;Park, Ji-Woong;Jin, Hyeong-Seok;Lee, Hyeon-Cheol
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.2
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    • pp.97-104
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    • 2017
  • In this paper, we designed and fabricated the multi band Transceiver Assembly(TCA) for the Multi Channel Synthetic Aperture Radar(MCSAR) containing C-band, X-band, Ku-band and we researched to verify electrical performance of TCA. The transceiver consists of transmitters, receivers, signal selection modules for each band, and stability oscillator, frequency synthesizer, controller, power distributor. The transceiver has a receive path selection and bandwidth selection functions in accordance with the operating mode. And the transceiver can transmit and receive all three bands simultaneously, each band has a bandwidth of up to 300 MHz. Final transmission output of transceiver for each band is over 20 dBm to be suitable for driving the T/R module. Receiver bandwidth is selected according to the required function and receiver gain has approximately C-band 52 dB, X-band 50 dB, Ku-band 60 dB, the maximum noise figure of Ku-band V polarization is 4.28 dB in the whole band H, V polarization. As a result of the electrical performance test, a multi-band TCA is satisfied the property requirements of the MCSAR.

A study on design for animal X-ray detector using CFRP CNT panel (CFRP CNT 패널을 적용한 동물용 X-ray 디텍터 디자인에 관한 연구)

  • Lee, Suk-Hyun;Kim, Hyun-Sung;Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.6
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    • pp.264-270
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    • 2020
  • Design was developed through user-oriented service design methodology and survey was conducted on material selection criteria for prototype production to select CFRP (Carbon Fiber Reinforced Plastics) CNT (Carbon Nano Tube), which was applied to animal X-ray detector panel to design product and develop prototype. Completed prototype with the application of CFRP CNT panel was tested in drop test, frontal external pressure test, and dustproof/waterproof performance to confirm that it can be utilized as a portable animal X-ray detector used in outdoor environment.

A Study on the Estimation of Ocean Surface Wave Information from Marine Radar Signals (선박 레이더 영상신호를 이용한 파랑정보 검출에 관한 연구)

  • Song, Chae-Uk;Kim, Chang-Je;Moon, Seong-Bae
    • Journal of Navigation and Port Research
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    • v.27 no.5
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    • pp.499-504
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    • 2003
  • This paper describes the system for evaluating the sea wave informations such as wave direction and wave length in real time, by using image data obtained from the marine X-band radar. We proposed here a method for automatic selection of the partial image data without the user's individual selection at the radar. We also discussed that the wave direction could be obtained by a 2-dimensional discrete Fourier transform algorithm. We carried some evaluation works on the algorithm through computer simulation. The obtained thirteen radar image data under several sea surface conditions were analyzed by the method described and the result was presented.

Design and Application of the TFM Based System Test Model for the Weapon System Embedded Software (무기체계 임베디드 소프트웨어에 대한 TFM 기반 시스템 테스트 모델 설계 및 적용)

  • Kim, Jae-Hwan;Yoon, Hee-Byung
    • The KIPS Transactions:PartD
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    • v.13D no.7 s.110
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    • pp.923-930
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    • 2006
  • In this paper we design the system test model for the weapon system embedded software based on the Time Factor Method(TFM) considering time factors and suggest the results through the case study. For doing this, we discuss the features, system tests and the object-oriented model based UML notations of the weapon system embedded software. And we give a test method considering time factors, a measuring method to time factors, and a test case selection algorithm as an approach to the TFM for designing the system test model. The TFM based system test model consists of three factors (X, Y, Z) in the weapon system embedded software. With this model, we can extract test cases through the selection algorithm for a maximum time path in 'X', identify the objects related to the Sequence Diagram in 'Y' and measure the execution time of each objects which is identified by the Timing Diagram in 'Z' Also, we present the method of extracting the system test cases by applying the proposed system test model to the 'Multi-function missile defense system'.

Link selection based on switching between full-duplex and half-duplex modes

  • Kim, Sangchoon
    • ETRI Journal
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    • v.42 no.1
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    • pp.17-25
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    • 2020
  • Multiple-input multiple-output systems can achieve a full sum rate (SR) via full duplex (FD). However, its performance is degraded by self-interference (SI) that occurs between the transmitter and receiver at the same node and thus is constrained by error floors. Conversely, half duplex (HD) can avoid the SI albeit at lower spectral efficiency, and the slope of its error curve is determined by the diversity order. In this study, a link selection scheme based on switching between FD and HD is examined as a simple method to improve the bit error rate (BER) performance of FD systems. In the proposed link selection algorithm, either FD or HD is selected based on the received minimum distance and signal-to-interference plus noise ratio. Simulation results indicate that the proposed hybrid FD/HD switching system offers significant BER performance improvement when compared with that of the conventional FD and FD based on only the received minimum distance under the same fixed SR. Under relatively sufficient SI cancellation, it is demonstrated to outperform the HD with a diversity advantage in low and medium signal-to-noise ratio region.

The Effect of Fashion Leadership on Fashion Products Purchase in Surrogate Internet Shopping Mall (유행선도력에 따른 대행 인터넷 쇼핑몰의 패션제품 구매행동)

  • Song, Myung-Hwa;Hwang, Jin-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.2
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    • pp.179-189
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    • 2008
  • The purposes of this study were to segment surrogate internet shopping mall consumers by fashion leadership and to find the differences among the segmented groups in regard to surrogate internet shopping perceived risks, selection criteria, dissatisfactions with surrogate shopping malls, and other purchase behavior. The subjects of this study were female consumers who were users of surrogate internet shopping malls. The data were collected during October, 2005. The respondents returned the questionnaires and 283 questionnaires were finally used in the data analysis. The statistical analyses used for the study were factor analysis, ANOVA, Duncan test, and $X^2$-test. The results showed that consumers were segmented by four groups: fashion dual leaders, fashion leaders, fashion followers, and fashion laggards. These segmented groups were significantly different in regard to surrogate internet shopping mall perceived risks, selection criteria, dissatisfactions with surrogate shopping malls, and other purchase behavior. Generally, fashion dual leaders had less perceived risks, considered diverse selection criteria important, and were less dissatisfied with surrogate shopping malls. Also, the fashion dual leaders had a higher purchase frequency and paid a higher price on surrogate internet shopping malls.

Development of Inorganic Metal Oxide based Hole-Transporting Layer for High Efficiency Perovskite Solar Cell (고효율 페로브스카이트 태양전지용 무기 금속 산화물 기반 정공수송층의 개발)

  • Lee, Haram;Mai, Cuc Thi Kim;Jang, Yoon Hee;Lee, Doh-Kwon
    • Current Photovoltaic Research
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    • v.8 no.2
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    • pp.60-65
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    • 2020
  • In perovskite solar cells with planar heterojunction configuration, selection of proper charge-transporting layers is very important to achieve stable and efficient device. Here, we developed solution processible Cu doped NiOx (Cu:NiOx) thin film as a hole-transporting layer (HTL) in p-i-n structured methylammonium lead trihalide (MAPbI3) perovskite solar cell. The transmittance and thickness of NiOx HTL is optimized by control the spin-coating rate and Cu is additionally doped to improve the surface morphology of undoped NiOx thin film and hole-extraction properties. Consequently, a perovskite solar cell containing Cu:NiOx HTL with optimal doping ratio of Cu exhibits a power conversion efficiency of 14.6%.

The Prediction of the Expected Current Selection Coefficient of Single Nucleotide Polymorphism Associated with Holstein Milk Yield, Fat and Protein Contents

  • Lee, Young-Sup;Shin, Donghyun;Lee, Wonseok;Taye, Mengistie;Cho, Kwanghyun;Park, Kyoung-Do;Kim, Heebal
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.1
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    • pp.36-42
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    • 2016
  • Milk-related traits (milk yield, fat and protein) have been crucial to selection of Holstein. It is essential to find the current selection trends of Holstein. Despite this, uncovering the current trends of selection have been ignored in previous studies. We suggest a new formula to detect the current selection trends based on single nucleotide polymorphisms (SNP). This suggestion is based on the best linear unbiased prediction (BLUP) and the Fisher's fundamental theorem of natural selection both of which are trait-dependent. Fisher's theorem links the additive genetic variance to the selection coefficient. For Holstein milk production traits, we estimated the additive genetic variance using SNP effect from BLUP and selection coefficients based on genetic variance to search highly selective SNPs. Through these processes, we identified significantly selective SNPs. The number of genes containing highly selective SNPs with p-value <0.01 (nearly top 1% SNPs) in all traits and p-value <0.001 (nearly top 0.1%) in any traits was 14. They are phosphodiesterase 4B (PDE4B), serine/threonine kinase 40 (STK40), collagen, type XI, alpha 1 (COL11A1), ephrin-A1 (EFNA1), netrin 4 (NTN4), neuron specific gene family member 1 (NSG1), estrogen receptor 1 (ESR1), neurexin 3 (NRXN3), spectrin, beta, non-erythrocytic 1 (SPTBN1), ADP-ribosylation factor interacting protein 1 (ARFIP1), mutL homolog 1 (MLH1), transmembrane channel-like 7 (TMC7), carboxypeptidase X, member 2 (CPXM2) and ADAM metallopeptidase domain 12 (ADAM12). These genes may be important for future artificial selection trends. Also, we found that the SNP effect predicted from BLUP was the key factor to determine the expected current selection coefficient of SNP. Under Hardy-Weinberg equilibrium of SNP markers in current generation, the selection coefficient is equivalent to $2^*SNP$ effect.