• Title/Summary/Keyword: partial sequence

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Anti-Jamming Performance Analysis of Chirped BPSK System (Chirped BPSK 시스템의 항재밍 성능 분석)

  • 유형만;윤성렬;정병기;김용로;유흥균
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.6
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    • pp.906-911
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    • 2001
  • In this paper, LPI(low probability of intercept) and AJ(anti jamming) performance of the chirped BPSK system are analyzed. In the chirp method the cyclostationary of the signal is eliminated, since the instantaneous frequency is varied randomly within the whole spread bandwidth. Therefore, chirp method is considered for good LPI system against DAM(delay-and-multiplier) or SC (squaring circuit) interceptor which detects the chip rate or carrier frequency. Longer chirp duration makes the LPI performance better. From the simulation results, the chirp method has better AJ performance than DS(direct sequence) system in the PBNJ(partial band noise jammer) channel. At the same JSR(jammer to signal power ratio) level, chirped BPSK system has more robust AJ performance against MTJ(multi-tone jammer) than PBNJ.

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PAPR Reduction Method in Multi-Code CDMA System (다중 코드 CDMA 시스템에서 PAPR저감 기법)

  • 이강미;김상우;유흥균
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.7
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    • pp.685-691
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    • 2004
  • In this paper, we propose the hybrid methods of SLM(selected mapping) and predistortion, and PTS(partial transmit sequence) and predistortion to reduce PAPR(peak to average power ratio) and to decrease the nonlinear distortion of the nonlinear HPA(high power amplifier) in the multi-code CDMA(code division multiple access) system. The phase rotation factors are transmitted as side information in PTS and SLM methods play an important role in the BER performance. So, we present the theoretical BER equation when the errors of side information are considered in the multi-code CDMA communication system. Simulation results show that PAPR is reduced and nonlinear distortion is compensated by hybrid methods. Therefore BER performance is enhanced.

'Restriction-PCR' - a Superior Replacement for Restriction Endonucleases in DNA Cloning Applications

  • Klimkait, Thomas
    • BMB Reports
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    • v.33 no.2
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    • pp.162-165
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    • 2000
  • Polymerase chain reaction (PCR) is well established as an indispensable tool of molecular biology; and yet a limitation for cloning applications continues to be that products often require subsequent restriction to be that products often require subsequent restriction digests, blunt-end ligation, or the use of special linear vectors. Here a rapid, PCR-based system is described for the simple, restriction enzyme-free generation of synthetic, 'restriction-like' DNA fragments with staggered ends. Any 3'- or 5'-protruding terminus, but also non-palindromic overhangs with an unrestricted single strand length are specifically created. With longer overhangs, "Restriction-PCR" does not even require a ligation step prior to transformation. Thereby the technique presents a powerful tool e.g. for a successive, authentic reconstitution of sub-fragments of long genes with no need to manipulate the sequence or to introduce restriction sites. Since restriction enzyme-free and thereby devoid the limitations of partial DNA digests, "Restriction-PCR" allows a straight one-step generation and cloning of difficult DNA fragments that internally carry additional sites for specific sequence insertions or deletions can be precisely engineered into genes of interest. With these properties "Restriction-PCR" has the potential to add significant speed and versatility to a wide variety of DNA cloning applications.

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Low-Complexity Detection Techniques for High-Density DVD Systems (고밀도 DVD시스템을 위한 저 복잡도 검출 기법)

  • Cho, Han-Gyu;Woo, Choong-Chae;Joo, Man-Sic;Kang, Chang-Eon;Hong, Dae-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.10A
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    • pp.1000-1010
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    • 2002
  • Partial response maximum-likelihood (PRML) and fixed-delay tree search with decision feedback (FDTS/DF) yield a sub-optimum performance in storage systems. However, they suffer from the inevitable complexity problems. this paper focuses on detection schemes to overcome the drawbacks of the sequence detections by exploiting minimum run-length d=2. It is expected that the proposed systems yield substantial reductions of both processing speed and receiver complexity. When combined with a decision feedback equalization (DFE), they prove to keep pace with the FDTS/DF with ${\tau}$=2 and even outperform the PR(1111)ML at normalized density S>5.6.

Another View Point on the Performance Evaluation of an MC-DS-CDMA System

  • Chen, Joy Iong-Zong;Hsieh, Tai Wen
    • Journal of Communications and Networks
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    • v.11 no.3
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    • pp.240-247
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    • 2009
  • The results of performance analysis by adopting the channel scenarios characterized as Weibull fading for an multicarrierdirect sequence-coded division multiple access (MC-DS-CDMA) system are proposed in this investigation. On the other hand, an approximate simple expression with the criterion of bit error rate (BER) versus signal-to-noise ratio (SNR) method is derived for an MC-DS-CDMA system combining with maximal ratio combining (MRC) diversity based on the moment generating function (MGF) formula of Weibull statistics, and it associates with an alternative expression of Gaussian Q-function. Besides, the other point of view on the BER performance evaluation of an MC-DS-CDMA system is not only the assumption of both single-user and multi-user cases applied, but the phenomena of partial band interference (PBI) is also included. Moreover, in order to validate the accuracy in the derived formulas, some of the system parameters, such as Weibull fading parameter (${\beta}$), user number (K), spreading chip number (N), branch number (L), and the PBI (JSR) values, etc., are compared with each other in the numerical results. To the best of author's knowledge, it is a brand new idea which proposes the evaluation of the system performance for an MC-DS-CDMA system over the point of view with Weibull fading channel.

Pruning and Matching Scheme for Rotation Invariant Leaf Image Retrieval

  • Tak, Yoon-Sik;Hwang, Een-Jun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.2 no.6
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    • pp.280-298
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    • 2008
  • For efficient content-based image retrieval, diverse visual features such as color, texture, and shape have been widely used. In the case of leaf images, further improvement can be achieved based on the following observations. Most plants have unique shape of leaves that consist of one or more blades. Hence, blade-based matching can be more efficient than whole shape-based matching since the number and shape of blades are very effective to filtering out dissimilar leaves. Guaranteeing rotational invariance is critical for matching accuracy. In this paper, we propose a new shape representation, indexing and matching scheme for leaf image retrieval. For leaf shape representation, we generated a distance curve that is a sequence of distances between the leaf’s center and all the contour points. For matching, we developed a blade-based matching algorithm called rotation invariant - partial dynamic time warping (RI-PDTW). To speed up the matching, we suggest two additional techniques: i) priority queue-based pruning of unnecessary blade sequences for rotational invariance, and ii) lower bound-based pruning of unnecessary partial dynamic time warping (PDTW) calculations. We implemented a prototype system on the GEMINI framework [1][2]. Using experimental results, we showed that our scheme achieves excellent performance compared to competitive schemes.

Identification of chromosomal translocation causing inactivation of the gene encoding anthocyanidin synthase in white pomegranate (Punica granatum L.) and development of a molecular marker for genotypic selection of fruit colors

  • Jeong, Hyeon-ju;Park, Moon-Young;Kim, Sunggil
    • Horticulture, Environment, and Biotechnology : HEB
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    • v.59 no.6
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    • pp.857-864
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    • 2018
  • Previous studies have not detected transcripts of the gene encoding anthocyanidin synthase (ANS) in white pomegranates (Punica granatum L.) and suggest that a large-sized insertion in the coding region of the ANS gene might be the causal mutation. To elucidate the identity of the putative insertion, 3887-bp 5' and 3392-bp 3' partial sequences of the insertion site were obtained by genome walking and a gene coding for an expansin-like protein was identified in these genome-walked sequences. An identical protein (GenBank accession OWM71963) isolated from pomegranate was identified from BLAST search. Based on information of OWM71963, a 5.8-Mb scaffold sequence with genes coding for the expansin-like protein and ANS were identified. The scaffold sequence assembled from a red pomegranate cultivar also contained all genome-walked sequences. Analysis of positions and orientations of these genes and genome-walked sequences revealed that the 27,786-bp region, including the 88-bp 5' partial sequences of the ANS gene, might be translocated into an approximately 22-kb upstream region in an inverted orientation. Borders of the translocated region were confirmed by PCR amplification and sequencing. Based on the translocation mutation, a simple PCR codominant marker was developed for efficient genotyping of the ANS gene. This molecular marker could serve as a useful tool for selecting desirable plants at young seedling stages in pomegranate breeding programs.

Improving PAPR performance of filtered OFDM for 5G communications using PTS

  • Al-Jawhar, Yasir Amer;Ramli, Khairun N.;Taher, Montadar Abas;Shah, Nor Shahida M.;Mostafa, Salama A.;Khalaf, Bashar Ahmed
    • ETRI Journal
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    • v.43 no.2
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    • pp.209-220
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    • 2021
  • The filtered orthogonal frequency division multiplexing (F-OFDM) system has been recommended as a waveform candidate for fifth-generation (5G) communications. The suppression of out-of-band emission (OOBE) and asynchronous transmission are the distinctive features of the filtering-based waveform frameworks. Meanwhile, the high peak-to-average power ratio (PAPR) is still a challenge for the new waveform candidates. Partial transmit sequence (PTS) is an effective technique for mitigating the trend of high PAPR in multicarrier systems. In this study, the PTS technique is employed to reduce the high PAPR value of an F-OFDM system. Then, this system is compared with the OFDM system. In addition, the other related parameters such as frequency localization, bit error rate (BER), and computational complexity are evaluated and analyzed for both systems with and without PTS. The simulation results indicate that the F-OFDM based on PTS achieves higher levels of PAPR, BER, and OOBE performances compared with OFDM. Moreover, the BER performance of F-OFDM is uninfluenced by the use of the PTS technique.

Performance Comparison of the OFDM/SFH and OFDM/DS Systems in the Jamming Channel (OFDM/SFH와 OFDM/DS 시스템의 Jamming 채널에서 성능비교)

  • 박종현;김상우;유흥균;이상태
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.11
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    • pp.1149-1155
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    • 2003
  • OFDM/SFH(orthogonal frequency division multiplexing/slow frequency hopping) system is the combination of OFDM communication system with frequency hopping(FH) method and OFDM/DS(orthogonal frequency division multiplexing/direct sequence) system combines the OFDM communication system with direct sequence(DS) method in terms of PN(pseudo noise) sequence. These two systems are also can be used for anti-jamming. In this study we analyze performances of OFDM/SFH system and OFDM/DS system with the equal information rate in partial band jamming and tone jamming channel. We find BER(bit error rate) in the variation of JFR(jamming fractional ratio) and JSR(jamming to signal power ratio) of the partial band jamming. Also, BER is found in the several JSR of the single tone or multi tone jamming. OFDM/DS system shows better performance than OFDM/SFH system in partial band jamming environment. OFDM/DS system has about 2.5 ㏈ SNR(signal to noise power ratio) gains than OFDM/SFH system when JFR=4/16 and JSR=0 ㏈ to meet BER=10$\^$-3/. However, OFDM/SFH system has about 3 ㏈ SNR gains than OFDM/DS system at single tone jamming of JSR=5 ㏈. In multi tone jamming, performance of OFDM/SFH system is considerably degraded than OFDM/DS system.

Cloning and Expression of the Cathepsin F-like Cysteine Protease Gene in Escherichia coli and Its Characterization

  • Joo, Han-Seung;Koo, Kwang-Bon;Park, Kyun-In;Bae, Song-Hwan;Yun, Jong-Won;Chang, Chung-Soon;Choi, Jang-Won
    • Journal of Microbiology
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    • v.45 no.2
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    • pp.158-167
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    • 2007
  • In this study, we have cloned a novel cDNA encoding for a papain-family cysteine protease from the Uni-ZAP XR cDNA library of the polychaete, Periserrula leucophryna. This gene was expressed in Escherichia coli using the T7 promoter system, and the protease was characterized after partial purification. First, the partial DNA fragment (498 bp) was amplified from the total RNA via RT-PCR using degenerated primers derived from the conserved region of cysteine protease. The full-length cDNA of cysteine protease (PLCP) was prepared via the screening of the Uni-ZAP XR cDNA library using the $^{32}P-labeled$ partial DNA fragment. As a result, the PLCP gene was determined to consist of a 2591 bp nucleotide sequence (CDS: 173-1024 bp) which encodes for a 283-amino acid polypeptide, which is itself composed of an 59-residue signal sequence, a 6-residue propeptide, a 218-residue mature protein, and a long 3'-noncoding region encompassing 1564 bp. The predicted molecular weights of the preproprotein and the mature protein were calculated as 31.8 kDa and 25 kDa, respectively. The results of sequence analysis and alignment revealed a significant degree of sequence similarity with other eukaryotic cysteine proteases, including the conserved catalytic triad of the $Cys^{90},\;His^{226},\;and\;Asn^{250}$ residues which characterize the C1 family of papain-like cysteine protease. The nucleotide and amino acid sequences of the novel gene were deposited into the GenBank database under the accession numbers, AY390282 and AAR27011, respectively. The results of Northern blot analysis revealed the 2.5 kb size of the transcript and ubiquitous expression throughout the entirety of the body, head, gut, and skin, which suggested that the PLCP may be grouped within the cathepsin F-like proteases. The region encoding for the mature form of the protease was then subcloned into the pT7-7 expression vector following PCR amplification using the designed primers, including the initiation and termination codons. The recombinant cysteine proteases were generated in a range of 6.3 % to 12.5 % of the total cell proteins in the E. coli BL21(DE3) strain for 8 transformants. The results of SDS-PAGE and Western blot analysis indicated that a cysteine protease of approximately 25 kDa (mature form) was generated. The optimal pH and temperature of the enzyme were determined to be approximately 9.5 and $35^{\circ}C$, respectively, thereby indicating that the cysteine protease is a member of the alkaline protease group. The evaluation of substrate specificity indicated that the purified protease was more active towards Arg-X or Lys-X and did not efficiently cleave the substrates with non-polar amino acids at the P1 site. The PLCP evidenced fibrinolytic activity on the plasminogen-free fibrin plate test.