• Title/Summary/Keyword: windowing

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The Brassica/Arabidopsis Comparative Genome Browser A Novel Approach to Genome Browsing

  • Lewis Christopher T.;Sharpe Andrew G.;Lydiate Derek J.;Parkin Isobel A.P.
    • Journal of Plant Biotechnology
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    • v.5 no.4
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    • pp.197-200
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    • 2003
  • Scalable Vector Graphics (SVG) has enabled a visually appealing, browser-based application for the display of Brassica sequences relative to Arabidopsis thaliana, and there are currently more than 70,000 B. napus Expressed Sequence Tags (ESTs) displayed. The client side of this browser is based on a Custom Graphical User Interface (CGUI) library which uses SVG, a new web graphics standard, to provide windowing functionality inside the web browser. This windowing functionality, combined with asynchronous data retrieval and client side rendering overcomes two of the key technology imposed drawbacks of current web based browsers: Fixed displays and frequent page reloads. The end result is an intuitive and enjoyable browsing experience. The browser is accessible online from the Brassica / Arabidopsis Genomics Initiative (http://brassica.agr.gc.ca). Inquiries about the browser should be directed to LewisCT@agr.gc.ca.

Performance Evaluation of a Windowed-Sinc Function-Based PAPR Reduction Scheme for OFDM Polar Transmitters (OFDM polar transmitter를 위한 windowed-sinc 함수 기반의 PAPR 감소기법의 성능평가)

  • Seo, Man-Jung;Shim, Hee-Sung;Im, Sung-Bin
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.1
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    • pp.10-18
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    • 2010
  • The polar transmitter is applied to the narrowband communication systems such as GSM (Global System for Mobile Communications), EDGE (Enhanced Data Rates for GSM Evolution), and GPRS (General Packet Radio Service). To apply polar transmitter for the wideband communication like OFDM (Orthogonal Frequency Division Multiplexing) where the high PAPR (Peak-to-Average Power Ratio) problem occurs, this paper proposes a windowed-sinc function based PAPR reduction scheme. The proposed algorithm mitigates the effect of excessive suppression due to successive peaks or relatively high peaks of the signal. The BER (Bit Error Rate) and EVM (Error Vector Magnitude) performances are measured for various window types and lengths. The simulation results demonstrate that the proposed algorithm achieves significant improvement in terms of BER and PAPR reduction performance with similar spectrum performance to the conventional peak windowing scheme.

Performance analysis of UWB receiver using PPM and BPSK modulation scheme in the LR-WPAN System (LR-WPAN 시스템에서 PPM+BPSK 변조 방식을 사용하는 UWB 송수신기의 성능 분석)

  • Lee, Kyoung-Tak;Lim, Dong-Guk;Sohn, Sung-Hwan;Kim, Jae-Moung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.5 no.2 s.10
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    • pp.19-28
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    • 2006
  • In the IEEE 802.15.4a system, they require simple, economical and low power consumption transmitter and receiver to transmit low rate data and to identify distance and location. To meet these requirements, LR-WPAN system use transmitter and receiver with simple modulation and demodulation scheme. In this paper, use PPM+BPSK modulation and windowing scheme to overcome multipath fading effect. Then we apply this channel estimation scheme to LR-WPAN system and compare performance depends on transmitter scheme. Proposed method using preamble to find channel characteristic out and we compensate distorted data with that information. Therefore we can detect signal easily at the demodulation part. Simulation result shows that performance evaluation is greater at the NLOS channel than LOS channel no matter what the receiver scheme.

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Depth From Defocus using Wavelet Transform (웨이블릿 변환을 이용한 Depth From Defocus)

  • Choi, Chang-Min;Choi, Tae-Sun
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.42 no.5 s.305
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    • pp.19-26
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    • 2005
  • In this paper, a new method for obtaining three-dimensional shape of an object by measuring relative blur between images using wavelet analysis has been described. Most of the previous methods use inverse filtering to determine the measure of defocus. These methods suffer from some fundamental problems like inaccuracies in finding the frequency domain representation, windowing effects, and border effects. Besides these deficiencies, a filter, such as Laplacian of Gaussian, that produces an aggregate estimate of defocus for an unknown texture, can not lead to accurate depth estimates because of the non-stationary nature of images. We propose a new depth from defocus (DFD) method using wavelet analysis that is capable of performing both the local analysis and the windowing technique with variable-sized regions for non-stationary images with complex textural properties. We show that normalized image ratio of wavelet power by Parseval's theorem is closely related to blur parameter and depth. Experimental results have been presented demonstrating that our DFD method is faster in speed and gives more precise shape estimates than previous DFD techniques for both synthetic and real scenes.

A Study on Efficient UWB Positioning Error Compensation Technique (효율적인 UWB 무선 측위 오차 보상 기법에 관한 연구)

  • Park, Jae-Wook;Bae, Seung-Chun;Lee, Soon-Woo;Kang, Ji-Myung;Lee, Won-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.10A
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    • pp.727-735
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    • 2009
  • To alleviate positioning error using wireless ultra-wideband (UWB) is primary concern, and it has been studied how to reduce the positioning error effectively. Thanks to many repeated transmissions of UWB signals, we can have a variety of selections to point out the most precise positioning result. Towards this, scanning method has been preferred to be used due to its simplicity. This exhaustive method firstly fixes the candidate position, and calculates the sum of distances from observed positions. However, it has tremendous number of computations, and the complexity is more serious if the size of two-dimensional range is the larger. To mitigate the large number of computations, this paper proposes the technique employing genetic algorithm and block windowing. To exploit its superiority, simulations will be conducted to show the reduction of complexity, and the efficiency on positioning capability.

Performance Evaluation of a Peak Windowing-Based PAPR Reduction Scheme in OFDM Polar Transmitters (OFDM polar transmitter에서 피크 윈도잉 기반의 PAPR 감소기법의 성능평가)

  • Seo, Man-Jung;Shin, Hee-Sung;Im, Sung-Bin;Jung, Jae-Ho;Lee, Kwang-Chun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.12
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    • pp.42-48
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    • 2008
  • Next generation wireless communication systems require RF transceivers that enable multiband/multimode operations. Polar transmitters are known as good candidates for high data rate systems such as EDGE (Enhanced Data Rates for GSM Evolution), WCDMA (Wideband Code Division Multiple Access), and WLAN (Wireless Local Area Network) because they can obtain high efficiency by using efficient switched-mode RF power amplifiers. In this paper, we investigate the performance of a simple peak windowing scheme for the OFDM (Orthogonal frequency Division Multiplexing) polar transmitter, which requires no change of a receiver structure or no additional information transmission. The approach we employed is to apply the peak windowing scheme to the amplitude modulated signals of the polar transmitter to reduce the PAPR (Peak-to-Average Power Ratio). The BER (Bit Error Rate) and EVM (Error Vector Magnitude) performances are measured for various window types and lengths. The simulation results demonstrate that the proposed algorithm mitigates out-of-band distortion introduced by clipping along with PAPR reduction.

A Corpus-based Lexical Analysis of the Speech Texts: A Collocational Approach

  • Kim, Nahk-Bohk
    • English Language & Literature Teaching
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    • v.15 no.3
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    • pp.151-170
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    • 2009
  • Recently speech texts have been increasingly used for English education because of their various advantages as language teaching and learning materials. The purpose of this paper is to analyze speech texts in a corpus-based lexical approach, and suggest some productive methods which utilize English speaking or writing as the main resource for the course, along with introducing the actual classroom adaptations. First, this study shows that a speech corpus has some unique features such as different selections of pronouns, nouns, and lexical chunks in comparison to a general corpus. Next, from a collocational perspective, the study demonstrates that the speech corpus consists of a wide variety of collocations and lexical chunks which a number of linguists describe (Lewis, 1997; McCarthy, 1990; Willis, 1990). In other words, the speech corpus suggests that speech texts not only have considerable lexical potential that could be exploited to facilitate chunk-learning, but also that learners are not very likely to unlock this potential autonomously. Based on this result, teachers can develop a learners' corpus and use it by chunking the speech text. This new approach of adapting speech samples as important materials for college students' speaking or writing ability should be implemented as shown in samplers. Finally, to foster learner's productive skills more communicatively, a few practical suggestions are made such as chunking and windowing chunks of speech and presentation, and the pedagogical implications are discussed.

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Development of TV-IF SAW Filter I-Comparison of the Design Methods and Fabrication (TV용 탄성표면파 필터의 개발 I-설계방법의 비교 및 제작방법)

  • 김진하;남정현
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.21 no.5
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    • pp.17-26
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    • 1984
  • This paper reports the design methods and fabrication processes developed for a TV-lF SAW filter. The windowing method, the frequency sampling method, and the time sampling method were studied and compared to obtain a satisfactory initial impulse response. To obtain high attenuation near the trap frequency, diffraction effects were compensated. The 4fo sampling technique was used for avoiding multiple reflections at finger edges and obtaining an asymmetrical frequency response, and effective photolithographic techniques were used for electrode fingers with 11.2$\mu$ width. The developed filter is of sufficiently small size to be cost-effective and satisfies the industry specifications required for mass production.

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The Improvement in Signal Integrity of FT-ICR MS (FT-ICR 질량분석기의 신호 충실성 향상)

  • Kim, Seung-Yong;Kim, Seok-Yoon;Kim, Hyun Sik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.1
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    • pp.201-204
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    • 2011
  • For efficient noise reduction in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrum, a new algorithm was proposed. The suggested algorithm reduces white and electrical noise, and it improves signal-to-noise ratio. This algorithm has been optimized to reduce the noise more efficiently using the traces of signal level. The algorithm has been efficiently combined with derivative window to improve the resolution as well S/N. Time domain data was corrected for DC voltage interference. $t^n$ window was applied in time domain data to improved the resolution. However, $t^n$ window can improve the signal resolution, it will also increase the noise level in frequency domain. Therefore, newly developed noise reduction algorithm will be applied to make a balance between resolving power and S/N ratio for magnitude mode. The trace algorithm can determine the current data point with several data points (mean, past data, calculated past data). In the current calculations, we assumed data points with S/N ratio more than 3 were considered as signal data points. After the windowing and noise reduction, both resolution and signal-to-noise ratio were improved. This algorithm is applicable more efficiently to frequency dependent noise and large size data.