检索结果-内蒙古大学图书馆

errors in Time-Series Remote Sensing and an Open Access Application for Detecting and Visualizing Spatial Data Outliers Using Google Earth Engine

引用

IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING 2019年第4期12卷 1165-1174页

作者： Peter, Brad G. Messina, Joseph P. Michigan State Univ Dept Geog Environm & Spatial Sci E Lansing MI 48823 USA Michigan State Univ Ctr Global Change & Earth Observat E Lansing MI 48823 USA

Remotely sensed measures of productivity are frequently used to characterize global agriculture and vegetated ecosystems, and are often downscaled to describe local, remote areas where finer spatial and temporal resolution data are regularly unavailable. While data errors may propagate throughout any analytical procedure, those that are missed during delivery and preliminary data mining require more attention. Here, a collection of formerly and presently available global remote sensing products are compiled to demonstrate the temporal and geographic breadth of remote sensing uncertainty. Vegetation productivity measures are invaluable for monitoring global health, but erroneous estimates that go unrecognized may result in serious policy mistakes. It is eminently clear that generalizable and accessible a priori methods for anomaly detection are lacking and urgently needed so that data errors are recognized before public delivery and before widespread use. Simple yet effective statistics such as the modified Z-score, Tukey's outliers, and Geary's C are leveraged here to identify, locate, and visualize the types of outliers that remote sensing data users may elect to omit or correct. Contributing to the growing ensemble of Google Earth Engine methodologies, we propose this generalizable method of detecting spatial outliers for remote sensing error management by users across scientific domains.

关键词： Data handling error detection coding remote sensing spatial data structures vegetation mapping

来源：评论

学校读者我要写书评

暂无评论

A CMOS 6-b, 400-MSample/s ADC with error correction

引用

IEEE JOURNAL OF SOLID-STATE CIRCUITS 1998年第12期33卷 1939-1947页

作者： Tsukamoto, S Schofield, WG Endo, T Fujitsu VLSI Ltd Aichi Japan Fujitsu Microelect Ltd Maidenhead SL6 4BW Berks England

A CMOS 6-bit 400-MSample/s (MS/s) hash analog/digital converter (ADC) using an additional comparator for background autozeroing has been developed. Additionally, an error-correction technique detects and corrects errors after thermometer code zero-to-one transition detection, improving the error rate from 10E-4 to 10E-8 at 400 MS/s with a 200-MHz analog input, This ADC was fabricated in a single-poly, double-metal, 0.35-mu m CMOS technology and occupies 1.6 x 0.75 mm. The power consumption is 190 mW at 400 MS/s with 3.0-V power supply. This ADC has a two-clock cycle latency.

关键词： analog-digital conversion CMOS analog integrated circuits encoding error correction error correction coding error detection coding Gray codes

来源：评论

学校读者我要写书评

暂无评论

Two algorithms for constructing efficient Huffman-code based reversible variable length codes

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2008年第1期56卷 81-89页

作者： Lin, Chia-Wei Wu, Ja-Ling Chuang, Yuh-Jue Natl Taiwan Univ Dept Informat & Comp Sci Commun & Multimedia Lab Taipei 10764 Taiwan Chang Gung Univ Dept & Grad Inst Hlth Care Management Tao Yuan Taiwan

In this paper, Huffman-code based reversible variable length code (RVLC) construction algorithms are studied. We use graph models to represent the prefix, suffix and Hamming distance relationships among RVLC candidate codewords. The properties of the so-obtained graphs are investigated in detail, based on which we present two efficient RVLC construction algorithms: Algorithm 1 aims at minimizing the average codeword length while Algorithm 2 jointly minimizes the average codeword length and maximizes the error detection probability at the same time.

关键词： error detection coding error synchronization variable length codes

来源：评论

学校读者我要写书评

暂无评论

Multistream transmission for hybrid IBOC-AM with embedded/multidescriptive audio coding

引用

IEEE TRANSACTIONS ON BROADCASTING 2002年第3期48卷 179-192页

作者： Lou, HL Sinha, D Sundberg, CEW Bell Labs Lucent Technol Multimedia Commun Res Lab Murray Hill NJ 07974 USA

Hybrid In Band on Channel (IBOC) digital audio broadcasting simultaneously with analog amplitude modulation (AM) has been proposed as a hybrid solution to digital audio broadcasting in the AM band. Since the AM band is crowded and since the available bandwidth per program is limited, adding digital transmission is a challenging proposition. To achieve FM like audio quality, an audio coder rate of 32-64 kb/sec may be required. One of the currently proposed hybrid IBOC-AM systems is 30 kHz wide. Severe second adjacent interference may occur in certain geographical. areas. This may lead to loss of 40% of the effective transmission audio bit rate. For coping with such harsh transmission conditions, we present a solution based on embedded/multidescriptive audio coding with matched multistream transmission in separate frequency bands. With loss of one frequency band, the embedded system blends to a lower audio coder rate with a much better quality than analog AM. The nonembedded system without multistream transmission fails catastrophically when a little more than one sideband is severely interfered with causing a severe discontinuity in quality while blending directly to analog AM. A number of detailed robust embedded systems are outlined. We also show how multistream transmission schemes can be used with nonembedded audio coders. Both daytime and nighttime scenarios are included. This paper contains a catalog of possible systems for different audio quality levels and interference scenarios, including systems with 20 kHz bandwidth rather than 30 kHz.

关键词： amplitude modulation audio coding channel coding digital audio broadcasting error detection coding radio broadcasting

来源：评论

学校读者我要写书评

暂无评论

Comparing Analytical, Micromagnetic and Statistical Channel Models at 4 Tcbpsi Patterned Media Recording

引用

IEEE TRANSACTIONS ON MAGNETICS 2012年第5期48卷 1826-1832页

作者： Chua, M. Elidrissi, M. R. Eason, K. Zhang, S. H. Qin, Z. L. Chai, K. S. Tan, K. P. Cai, K. Chan, K. S. Goh, W. L. Dong, Y. Victora, R. H. ASTAR Data Storage Inst Singapore 117608 Singapore Nanyang Technol Univ Sch Elect & Elect Engn Singapore 637457 Singapore Univ Minnesota Ctr Micromagnet & Informat Technol Dept Elect & Comp Engn Minneapolis MN USA

Bit patterned media recording (BPMR) is a candidate technology proposed to extend the areal density growth capability of magnetic recording systems. In conventional granular magnetic recording (CGMR), bits of information are recorded onto a number of randomly distributed magnetic grains. The difficulty for the granular media approach is that due to the randomness of the grains, a certain minimum number of grains are required in order to maintain the media signal to noise ratio (SNR). This requires smaller grains as the bits are shrunk and we end up with either unstable, or unwriteable grains as per the well-known media-trilemma. In BPMR, instead of random positions, the "grains" are ordered into a well-defined lattice of magnetic islands. Because of this ordering, the media SNR is no longer determined by the number of grains per bit as in CGMR, but is defined by the geometrical and magnetic distributions of the fabrication process of the media. Analytical models exist for BPMR, that flip grains in the media based on the switching field distribution (SFD) and the knowledge of the applied head field. On the other side, a statistical model for CGMR has been proposed that measures probabilities of grains flipping based on micromagnetic simulations, named the grain flipping probability (GFP) model. In this work, we adapt the GFP model for BPMR and perform a comparison between densities predicted via the analytical and GFP models, by processing the signals from these models with the appropriate detectors and LDPC (low density parity check) decoders.

关键词： Codes error correction error correction coding error detection coding signal processing

来源：评论

学校读者我要写书评

暂无评论

Adaptive Viterbi algorithm with ARQ for bounded complexity decoding

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2004年第6期3卷 1948-1952页

作者： Harvey, BA Florida A&M Univ Florida State Univ Joint Coll Engn Dept Elect & Comp Engn Tallahassee FL 32310 USA

Adaptive bounded computational and memory requirements for a Viterbi decoder can be achieved using an error trapping Viterbi decoder algorithm initially develop for hybrid automatic repeat request (ARQ) implementations. Partial path metrics and a sliding window are used to eliminate unreliable paths in the decoder trellis thus reducing the computational and memory requirements. An ARQ is issued if all paths are eliminated. The algorithm is adaptive allowing the receiver to dynamically allocate memory and processing, to improve reliability or received packets, or to reject packets with lower reliability to avoid buffer overruns. The result is the ability to trade off resources versus delay and throughput.

关键词： automatic repeat request error control coding error detection coding Viterbi decoding

来源：评论

学校读者我要写书评

暂无评论

An error-protected speech recognition system for wireless communications

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2002年第2期1卷 282-291页

作者： Weerackody, V Reichl, W Potamianos, A Bell Labs Lucent Technol Murray Hill NJ 07974 USA

Future wireless multimedia terminals will have a variety of applications that require speech recognition capabilities. In this paper, we consider a robust distributed speech recognition system where representative parameters of the speech signal are extracted at the wireless terminal and transmitted to a centralized automatic speech recognition (ASR) server. We propose two unequal error protection schemes for the ASR bit stream and demonstrate the satisfactory performance of these schemes for typical wireless cellular channels. In addition, a "soft-feature" error concealment strategy is introduced at the ASR server that uses "soft-outputs" from the channel decoder to compute the marginal distribution of only the reliable features during likelihood computation at the speech recognizer. This soft-feature error concealment technique reduces the ASR error rate by more than a factor of 2.5 for certain channels. Also considered is,a channel decoding technique with source information that improves ASR performance.

关键词： error detection coding Gaussian fading channel mobile communication speech codecs speech recognition

来源：评论

学校读者我要写书评

暂无评论

Near-Optimal Contraction of Voronoi Regions for Pruning of Blind Decoding Results

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2015年第6期63卷 1963-1974页

作者： Bai, Dongwoon Lee, Jungwon Kim, Sungsoo Kim, Hanju Kang, Inyup Samsung Modem R&D San Diego CA 92121 USA Samsung Elect Seoul 100742 South Korea

In Long-Term Evolution (LTE) downlink control channel, a large number of blind decoding attempts are made, while the number of valid codewords is limited. The blind decoding results are then verified using a 16-bit cyclic redundancy check (CRC). However, even with the 16-bit CRC, the false alarm (FA) rate of such blind decoding is inevitably high. This paper investigates the problem of pruning of blind decoding results for reduction of the FA rate. To the best of our knowledge, the approach using a soft correlation metric (SCM) shows the best FA reduction performance among existing schemes. However, following the Bayes principle, we propose novel likelihood-based pruning that provides systematic balancing between the FA rate and the miss (MS) rate. Moreover, the simulation results show that the signal-to-noise ratio (SNR) gain of our proposed scheme is unbounded, with respect to the SCM-based scheme, in the independent and identically distributed (i.i.d.) Rayleigh fading channel. Moreover, the proposed scheme is shown to be less complex than the existing scheme. Finally, it is proved that, as SNR increases, the proposed approach has the decision error probability that approaches the minimum value yielding near-optimal contraction of Voronoi regions for pruning of blind decoding results.

关键词： Bayes procedures blind decoding decision-making error correction coding error detection coding LTE downlink control channel PDCCH false alarm signal detection

来源：评论

学校读者我要写书评

暂无评论

Simplified Birthday Statistics and Hamming EDAC

引用

IEEE TRANSACTIONS ON NUCLEAR SCIENCE 2009年第2期56卷 474-478页

作者： Tausch, Hans J. T2 Res Albuquerque NM 87108 USA

Space systems use error detection and Correction (EDAC) schemes to protect memory contents from single event upsets (SEUs). Hamming EDAC is the preferred scheme for fast, random access memories. It allows for the correction of a single bit error within a word and the detection of a double bit error. The common assumption is that the likelihood of an uncorrectable double bit error is very small. This paper develops a simple equation that predicts the cumulative probability of a double bit error occurring within some word of Hamming protected memory as the number of random upsets increase and shows how it can be used to better understand the protection provided by EDAC.

关键词： error correction error detection coding Hamming codes integrated circuit radiation effects memory architecture memory fault tolerance radiation effects

来源：评论

学校读者我要写书评

暂无评论

Enhancing the error detection capabilities of the standard video decoder using pixel domain dissimilarity metrics

Enhancing the error detection capabilities of the standard v...

引用

International Conference on Computer as a Tool (EUROCON 2007)

作者： Farrugia, Reuben A. Debono, Carl J. Univ Malta Dept Commun & Comp Engn Msida Msd 2080 Malta

ISBN: (纸本)9781424408122

The video compression standards commonly adopted in wireless multimedia services utilize variable length codes (VLC) in order to attain high compression ratios. While providing the high data rates required, this technique makes the system more susceptible to transmission errors. Thus the end-to-end quality of the video stream transmitted over an error-prone channel depends on the detection, and concealment of the corrupted macroblocks. The error detection capability of standard decoders is quite limited, for example, in the case of the H.263+ codec around 40.54% of the corrupted macroblocks are undetected, placing a bound on the perceived quality of the reconstructed video sequence. This paper presents a novel solution using eight pixel domain dissimilarity metrics computed in the CIE LUV color space which can be used at decode time to improve the error detection rate of the standard decoder. The spatial dissimilarity metric has been found to perform the best with an average increase in error detection rate of 60.38% when compared to the standard decoder (about 20% more than other published results) with 0% of false detection and a gain in peak signal-to-noise ratio (PSNR) of 3.94 dB.

关键词： error detection coding quality assurance video codecs video signal processing

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：