• Title/Summary/Keyword: m-sequences

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Time Hopping Sequences Based on Pseudo Random Codes for Ultra Wideband Impulse Radio Systems

  • Kim, Sanhae;Park, Kwang-Hee;Suckchel Yang;Kim, Hak-Seong;Yoan Shin
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1350-1353
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    • 2002
  • A new form of spread spectrum technique called the ultra wideband impulse radio (UWB-IR) system has drawn much attention for future high speed wireless communication services. In this paper, a new type of time hopping sequences constructed from multiple distinct m-sequences of the same order, is proposed for multiple access in the UWB-IR systems. Simulation results reveal that the proposed time hopping sequences achieve comparable or even better bit error rate performance than the ideal random sequences, and can be effectively applied in various multiple access situations.

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New Binary Sequences of Period Pm-1 with Optimal Autocorrelation (최적의 자기상관 특성을 갖는 주기 \ulcorner-1인 이진시퀀스의 생성)

  • 노종선;정하봉;송홍엽;양경철;이정도
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.6B
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    • pp.1136-1142
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    • 2000
  • In this paper, we present a construction for binary sequences {s(t)} of period N= \ulcorner-1 for an odd prime \ulcornerbased on the polynomial (z+1)d+az d +b, and discuss them in some cases of parameters p, m, d, a and b. We show that new sequences from our construction are balanced or almost balanced, and have optimal three-level autocorrelation. We also derive the distribution of autocorrelation values they take on. The sequences satisfy constant-on-the-coset property, and we will show that there are more than one characteristic phases with constant-on-the-coset property. Some other interesting properties of these sequences will be presented. Results of an extensive computer search are summarized.

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THE HOMOLOGY REGARDING TO E-EXACT SEQUENCES

  • Ismael Akray;Amin Mahamad Zebari
    • Communications of the Korean Mathematical Society
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    • v.38 no.1
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    • pp.21-38
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    • 2023
  • Let R be a commutative ring with identity. Let R be an integral domain and M a torsion-free R-module. We investigate the relation between the notion of e-exactness, recently introduced by Akray and Zebari [1], and generalized the concept of homology, and establish a relation between e-exact sequences and homology of modules. We modify some applications of e-exact sequences in homology and reprove some results of homology with e-exact sequences such as horseshoe lemma, long exact sequences, connecting homomorphisms and etc. Next, we generalize two special drived functor T or and Ext, and study some properties of them.

Co-expression of IRES-mediated hG-CSF cDNA and hGH Gene under the Control of Goat beta-Casein Promoter

  • Oh, Keon-Bong;Lee, Chul-Sang
    • Development and Reproduction
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    • v.14 no.1
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    • pp.13-19
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    • 2010
  • We developed a novel dicistronic system for the expression of target cDNA sequences in the milk of transgenic animals using goat beta-casein/hGH fusion construct, pGbc5.5hGH (Lee, 2006) and internal ribosome entry site (IRES) sequences of encephalomyocarditis virus (EMCV). Granulocyte colony-stimulating factor (hG-CSF) cDNA was linked to 3' untranslated region of hGH gene in the pGbc5.5hGH via EMCV IRES sequences. Transgenic mice were generated by microinjection and transgene expression was examined in the milk and mammary gland of transgenic mice at 10 days of lactation. Northern blot analysis showed that hGH gene and hG-CSF cDNA were transcribed as a single dicistronic mRNA. The hG-CSF and hGH proteins were independently translated from the dicistronic mRNA and secreted into the milk of transgenic mice. The highest concentration of hG-CSF and hGH in the milk of transgenic mice were $237{\mu}g/m{\ell}$ and $8,990{\mu}g/m{\ell}$, respectively. In contrast, another hG-CSF expression cassette, in which hG-CSF genomic sequences were inserted into a commercial milk-specific expression vector (pBC1), generated a lower level ($91{\mu}g/m{\ell}$) of hG-CSF expression in the milk of transgenic mice. These results demonstrated that the novel pGbc5.5hGH-based dicistronic construct could be useful for an efficient cDNA expression in the milk of transgenic animals.

A Bit SLM Scheme for Peak to Average Power Ratio Reduction in OPDM Systems (직교 주파수 분할 다중화 시스템의 최대전력 대 평균전력의 비 감소를 위한 비트 선택사상 기법)

  • Kim, Kyu-Hong;Noh, Hyung-Suk;Heo, Seok-Joong;No, Jong-Seonh;Shin, Dong-Joon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.6C
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    • pp.444-449
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    • 2008
  • Selected mapping is well-known scheme for peak to average power ratio(PAPR) reduction in orthogonal frequency multiplexing(OFDM) systems. In this paper, we proposed a new scheme for generating a set of candidate transmission sequences. In conventional SLM, candidate sequences were generated by rotating the phases of the frequency domain OFDM M-ary symbols but in proposed scheme, candidate sequences are generated by multiplying the m-sequences with data in bit format of OFDM signals. Computer simulation results show that, as compared to the conventional SLM scheme, the proposed approach has better PAPR reduction performance and especially in case of OFDM systems which has small number of subcarriers has better performance than large ones.

ON THE MOMENTS OF BINARY SEQUENCES AND AUTOCORRELATIONS OF THEIR GENERATING POLYNOMIALS

  • Taghavi, M.
    • Journal of applied mathematics & informatics
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    • v.26 no.5_6
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    • pp.973-981
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    • 2008
  • In this paper we focus on a type of Unimodular polynomial pair used for digital systems and present some new properties of them which lead us to estimation of their autocorrelation coefficients and the moments of a Rudin-Shapiro polynomial product. Some new results on the Rudin-shapiro sequences will be presented in the last section. Main Facts: For positive integers M and n with $M\;<\;2^n$ - 1, consider the $2^n$ - M numbers ${\epsilon}_k$ ($M\;{\leq}\;k\;{\leq}\;2^n$ - 1) which form a collection of Rudin-Shapiro coefficients. We verify that $|{\sum}_{k=M}^{2^{n-1}}\;{{\epsilon}_k}e^{ikt}|$ is dominated by $(2+\sqrt{2})\;\sqrt {2^n-M}-{\sqrt{2}}$.

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Binary random sequence generation by use of random sampling of M-sequence

  • Hiroshi Harada;Hiroshi Kashiwagi;Satoshi Honda;Kazuo Oguri
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10a
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    • pp.832-835
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    • 1987
  • This paper proposes a new method of generating binary random sequences using a randomly sampled M-sequence. In this paper two methods of sampling are proposed. Expected values of the autocorrelation function of the sequence generated by these methods are calculated theoretically. From the results of computer simulation, it is shown that using these methods, we can get binary random sequences which have good random properties.

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AN INTRODUCTION TO 𝜖0-DENSITY AND 𝜖0-DENSE ACE

  • Kang, Buhyeon
    • Journal of the Chungcheong Mathematical Society
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    • v.32 no.1
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    • pp.69-86
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    • 2019
  • In this paper, we introduce a concept of the ${\epsilon}_0$-limits of vector and multiple valued sequences in $R^m$. Using this concept, we study about the concept of the ${\epsilon}_0$-dense subset and of the points of ${\epsilon}_0$-dense ace in the open subset of $R^m$. We also investigate the properties and the characteristics of the ${\epsilon}_0$-dense subsets and of the points of ${\epsilon}_0$-dense ace.

Some Aspects of λ-∆m-Statistical Convergence on Neutrosophic Normed Spaces

  • Reena Antal;Meenakshi Chawla
    • Kyungpook Mathematical Journal
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    • v.64 no.3
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    • pp.461-478
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    • 2024
  • Neutrosophication is a useful tool for handling real-world problems with partially dependent, partially independent, and even independent components. By examining some properties related to λ-statistical convergence on neutrosophic normed spaces, we provide some functional tools that are helpful in situations of inconsistency and indeterminacy. Additionally, we establish some related results on λ-∆m-statistical Cauchy sequences on neutrosophic normed spaces.

Genetic Characteristics of Porcine Epidemic Diarrhea Virus Isolated in Korea (돼지 유행성 설사 바이러스 국내분리주의 유전학적 특성 규명)

  • Chi, Yong-zhe;Kwon, Hyuk-moo;Jeong, Hyun-kyu;Han, Jeong-hee
    • Korean Journal of Veterinary Research
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    • v.43 no.2
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    • pp.219-230
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    • 2003
  • Porcine epidemic diarrhea virus(PED), a member of Coronaviridea, is the etiological agent of enteropathogenic diarrhea in swine. The purpose of this study was to investigate genetic characteristic of PEDV isolated in Korea. Nucleocapsid(N) gene and membrane (M) gene of recent Korean PEDV strains isolated in 2001 were amplified, cloned, sequenced and analyzed. N gene of seven Korean PEDV field isolates bad 94.5% to 99.4% nucleotide and 92.4% to 99.4% amino acid sequence homology each other. Nucleotide and amino acid sequences of Korean field PEDVs were different from published foreign PEDVs, showing 95.1% to 98.0% nucleotide and 93.5% to 97.6% amino acid sequence homology. By phylogenetic tree analysis on based nucleotide sequences, PEDVs were clustered into four groups. By phylogenetic tree analysis based on amino acid sequences. PEDVs were clustered into five groups. M gene of our Korean PEDV field isolates had 99.6% to 100% nucleotide and 98.7% to 100% amino acid sequence homology each other. Nuclotide and amino acid sequences of Korean field PEDVs were different from published foreign PEDVs, showing 98.5% to 98.8% nucleotide and 97.3% to 97.8% amino acid sequence homology. By phylogenetic tree analysis based on nucleotide and amino acid sequences, PEDVs were clustered into two groups which were Korean PEDV isolate group and foreign PEDV isolate group.