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Journal articles on the topic 'Layered space-time code'

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Published: 4 June 2021

Last updated: 20 February 2023

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1

Nasser, Youssef, and Jean-François Helard. "Layered space-time block code for hybrid satellite-terrestrial broadcasting systems." International Journal of Satellite Communications and Networking 30, no. 3 (March 15, 2012): 113–29. http://dx.doi.org/10.1002/sat.1001.

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2

Park, Gun-Woong, and Ji-Won Jung. "A Study of MIMO FTN Scheme based on Layered Space Time Code using Turbo Code." Journal of the Korea Institute of Information and Communication Engineering 20, no. 5 (May 31, 2016): 895–901. http://dx.doi.org/10.6109/jkiice.2016.20.5.895.

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3

Zhao, Zheng, Qinye Yin, Hong Zhang, and Aigang Feng. "A vertical layered space-time code and its closed-form blind symbol detection." Journal of Electronics (China) 20, no. 2 (March 2003): 102–9. http://dx.doi.org/10.1007/s11767-003-0004-z.

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4

Minallah, Nasru, Ishtiaque Ahmed, Jaroslav Frnda, and Khurram S. Khattak. "Averting BER Floor with Iterative Source and Channel Decoding for Layered Steered Space-Time Codes." Sensors 21, no. 19 (September 29, 2021): 6502. http://dx.doi.org/10.3390/s21196502.

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The widespread development in wireless technologies and the advancements in multimedia communication have brought about a positive impact on the performance of wireless transceivers. We investigate the performance of our three-stage turbo detected system using state-of-the-art high efficiency video coding (HEVC), also known as the H.265 video standard. The system makes use of sphere packing (SP) modulation with the combinational gain technique of layered steered space-time code (LSSTC). The proposed three-stage system is simulated for the correlated Rayleigh fading channel and the bit-error rate (BER) curve obtained after simulation is free of any floor formation. The system employs low complexity source-bit coding (SBC) for protecting the H.265 coded stream. An intermediate recursive unity-rate code (URC) with an infinite impulse response is employed as an inner precoder. More specifically, the URC assists in the prevention of the BER floor by distributing the information across the decoders. There is an observable gain in the BER and peak signal-to-noise ratio (PSNR) performances with the increasing value of minimum Hamming distance (dH,min) using the three-stage system. Convergence analysis of the proposed system is investigated through an extrinsic information transfer (EXIT) chart. Our proposed system demonstrates better performance of about 22 dB than the benchmarker utilizing LSSTC-SP for iterative source-channel detection, but without exploiting the optimized SBC schemes.

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5

Zhao, Chunli, Fengfan Yang, Rahim Umar, and Shoaib Mughal. "Two-Source Asymmetric Turbo-Coded Cooperative Spatial Modulation Scheme with Code Matched Interleaver." Electronics 9, no. 1 (January 16, 2020): 169. http://dx.doi.org/10.3390/electronics9010169.

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This paper proposes, for the first time, a two-source asymmetric turbo-coded-cooperative spatial modulation (SM) scheme over the slow Rayleigh fading channel. As in any coded cooperative communication, the interleaver plays a vital role in mitigating the harsh effect of the wireless channel. Therefore, the code matched interleaver (CMI) is effectively used in the proposed design. The simulated results reveal that the bit error rate (BER) performance of the proposed coded cooperative communication system outperforms the asymmetric turbo-coded non-cooperative scheme under identical conditions. This prominent performance improvement has been made possible due to the joint asymmetric turbo decoding at the destination node. Furthermore, to check the effectiveness of the proposed scheme, we have also developed a two-source asymmetric turbo-coded cooperative scheme based on the vertical bell labs layered space-time (VBLAST), incorporating the CMI as the suitable benchmark. It is observed that the proposed scheme employing SM has a better BER performance than the VBLAST scheme under identical conditions.

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6

Phasouliotis, A., and D. K. C. So. "Layered space–time receiver for downlink multiple-input multiple-output multi-carrier code division multiple access systems." IET Communications 5, no. 13 (September 5, 2011): 1907–17. http://dx.doi.org/10.1049/iet-com.2010.0367.

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7

Elabed, Salem. "COMPARATIVE ANALYSIS OF DIFFERENT RECEIVE ALGORITHMS FOR BLAST ARCHITECTURE IN MOBILE COMMUNICATION SYSTEMS." SYNCHROINFO JOURNAL 7, no. 4 (2021): 12–15. http://dx.doi.org/10.36724/2664-066x-2021-7-4-12-15.

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The Layered Space-Time Processing approach to STC was first introduced by Lucent’s Bell Labs, with their BLAST family of STC structures. The information bits are demultiplexed into individual streams, which are then fed into individual encoders. These coders may be binary convolutional coders, or even no coding at all. The outputs of the coders are modulated and fed to the separate antennas, from which they are transmitted, using the same carrier-frequency/symbol waveform (TDMA) or Walsh code (CDMA). At the receiver, a spatial beamforming/nulling (zero-forcing) process is used at the front end in order to separate the individual coded streams, and feed them to their individual decoders. The outputs of the decoders are multiplexed back to reconstruct the estimate of the original information bitstream. Various receivers for communication system with Space-Time Coding in MIMO Channel are considered. Performance analysis was provided by statistical simulation for various parameters of communication system.

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8

Lee, Dong-gi, Myungjun Kim, Sang Joon Son, Chang Hyung Hong, and Hyunjung Shin. "Dementia key gene identification with multi-layered SNP-gene-disease network." Bioinformatics 36, Supplement_2 (December 2020): i831—i839. http://dx.doi.org/10.1093/bioinformatics/btaa814.

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Abstract Motivation Recently, various approaches for diagnosing and treating dementia have received significant attention, especially in identifying key genes that are crucial for dementia. If the mutations of such key genes could be tracked, it would be possible to predict the time of onset of dementia and significantly aid in developing drugs to treat dementia. However, gene finding involves tremendous cost, time and effort. To alleviate these problems, research on utilizing computational biology to decrease the search space of candidate genes is actively conducted. In this study, we propose a framework in which diseases, genes and single-nucleotide polymorphisms are represented by a layered network, and key genes are predicted by a machine learning algorithm. The algorithm utilizes a network-based semi-supervised learning model that can be applied to layered data structures. Results The proposed method was applied to a dataset extracted from public databases related to diseases and genes with data collected from 186 patients. A portion of key genes obtained using the proposed method was verified in silico through PubMed literature, and the remaining genes were left as possible candidate genes. Availability and implementation The code for the framework will be available at http://www.alphaminers.net/. Supplementary information Supplementary data are available at Bioinformatics online.

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9

Wang, Haiquan, Yabo Li, Xiang-Gen Xia, and Shunlan Liu. "Unitary and Non-Unitary Precoders for a Limited Feedback Precoded OSTBC System." Vehicular Technology, IEEE Transactions on 62, no. 4 (May 2013): 1646–54. http://dx.doi.org/10.1109/tvt.2012.2233508.

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In this paper, a multiple-input-multiple-output (MIMO) system with finite-bit feedback first proposed by Love-Heath is considered, where a transmitted signal consists of a precode followed by an orthogonal space-time block code (OSTBC), such as Alamouti code. A new design criterion and a corresponding design method of precoders are proposed. Simulations show that the precoders obtained by our proposed criterion and method perform better than the existing ones. Furthermore, since our proposed precoders have a layered structure, their designs can be implemented in the simplest Grassmannian manifold. Moreover, a fast encoding algorithm can be applied, which can greatly reduce the complexity of codeword selection. In this paper, we also propose non-unitary precoders and their design criterion and method based on the performance analysis and the special property of an OSTBC. Interestingly, non-unitary precoders can significantly improve performance over unitary precoders.

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10

Ni, Liang Fang, Qing Qing Li, and Si Dan Du. "Complex Generalized Basis Reduction Assisted Successive Interference Cancellation Detection for SCBLAST Systems." Advanced Materials Research 366 (October 2011): 219–23. http://dx.doi.org/10.4028/www.scientific.net/amr.366.219.

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Complex generalized basis reduction assisted successive interference cancellation is proposed for mitigating multi-stream interference of transmitted signals in single code Bell Laboratories layered space-time systems. Generalized basis reduction method is modified to better the complex channel matrix, which leads to the extended generalized reduction basis channel matrix with shorter and roughly orthogonal basis vectors in polynomial-time. This distinguished property guarantees the concatenated successive interference cancellation detector, based on the MMSE criterion, converges to the approximately global optimum estimation points. Emulation results have shown that the proposed detection scheme is superior to other suboptimum detection schemes considered in this paper in terms of two points. They are the mitigation of multi-stream interference and the diversity gain. Its performance is close to the sphere decoder but with a lower complexity.

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11

Werthmüller, Dieter. "An open-source full 3D electromagnetic modeler for 1D VTI media in Python: empymod." GEOPHYSICS 82, no. 6 (November 1, 2017): WB9—WB19. http://dx.doi.org/10.1190/geo2016-0626.1.

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The Python-code empymod computes the 3D electromagnetic field in a layered earth with vertical transverse isotropy by combining and extending two earlier presented algorithms in this journal. The bottleneck in frequency- and time-domain calculations of electromagnetic responses derived in the wavenumber-frequency domain is the transformations from the wavenumber to the space domain and from the frequency to the time domain, the so-called Hankel and Fourier transforms. Three different Hankel transform methods (quadrature, quadrature-with-extrapolation [QWE], and filters) and four different Fourier transform methods (fast Fourier transform [FFT], FFTLog, QWE, and filters) are included in empymod, which allows us to compare these different methods in terms of speed and precision. The best transform in terms of speed and precision depends on the modeled frequencies. Published digital filters for the Hankel transform are very fast and precise for frequencies in the range of controlled-source electromagnetic data, but they fail in the frequency range of ground-penetrating radar. Conventional quadrature, on the other hand, is in comparison very slow but can model any frequency. Examples comparing empymod with analytical solutions and with existing electromagnetic modelers illustrate the capabilities of empymod.

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12

Wübben, D., R. Böhnke, J. Rinas, V. Kühn, and K. D. Kammeyer. "Efficient algorithm for decoding layered space-time codes." Electronics Letters 37, no. 22 (2001): 1348. http://dx.doi.org/10.1049/el:20010899.

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13

El-Hajjar, M., and L. Hanzo. "Layered steered space-time codes and their capacity." Electronics Letters 43, no. 12 (2007): 680. http://dx.doi.org/10.1049/el:20070862.

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14

Matache, A., and R. D. Wesel. "Universal trellis codes for diagonally layered space-time systems." IEEE Transactions on Signal Processing 51, no. 11 (November 2003): 2773–83. http://dx.doi.org/10.1109/tsp.2003.818159.

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15

Larsson, E. G., and W. H. Wong. "Nonuniform Unitary Space–Time Codes for Layered Source Coding." IEEE Transactions on Wireless Communications 3, no. 3 (May 2004): 958–65. http://dx.doi.org/10.1109/twc.2004.827741.

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16

Salim, Ahmad S., Salam A. Zummo, Samir N. Al-Ghadhban, and Ping-Cheng Yeh. "Optimized Power Allocation for Layered-Steered Space-Time Codes." Wireless Personal Communications 68, no. 1 (November 24, 2011): 95–113. http://dx.doi.org/10.1007/s11277-011-0441-1.

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17

Khrapova, Victoria. "Regional Text as a Factor of Organizing Modern Social Space." Logos et Praxis, no. 4 (March 2020): 102–7. http://dx.doi.org/10.15688/lp.jvolsu.2019.4.12.

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In the context of modern social transformation, the role of regions as territorial-economic complexes and administrative units, gaining the status of entities in the national system of relations, is strengthening. Important indicators of the formation of the region are regional culture and regional self-awareness, due to the commonality of experiences of significant events occurring in a certain territory at a certain time. The key values of the regional culture are fixed in the regional text – a symbolic complex that accumulates the concepts of regional culture. The specificity of the regional text is due to its formation bades on local symbolic and symbolic structures with explanatory potential and translating the idea of stability, reliability, and also, to a large extent, development in the media environment, dissemination in the media format that informs the regional text of innovative qualities that former media (mobility, flexibility, interactivity, fundamental openness at the semantic and structural-compositional levels) didn't have. The regional text carries an identification code, it contains life-preserving constants and lifesetting values. Possessing a built-in mechanism for the correction of semantic and syntactic relations, aimed at self-preservation of the social whole, the regional text performs constructive and projective functions in the context of modern social dynamics. Sign-symbolic complexes with regional semantics play an important role in the self-description of regional communities, allowing them to maintain self-identification, to recreate the conditions necessary for optimal interaction and life in the modern social space. The regional text plays a large role in shaping the image of the region, which determines its socio-economic status and cultural status. The modern regional text is mobile, multi-layered, discrete, and has no rigid structure. It is synergistically transforming into a dynamically changing society, depending on the goals and values that guide the regional community. The presence of control parameters in the structure of the regional text makes it an important factor in sustainable development and determines the need for the conscious participation of the political and intellectual elite in the creation of regional semiotic spaces.

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18

Salim, Ahmad S., Salam A. Zummo, and Samir N. Al-Ghadhban. "Performance of Layered Steered Space–Time Codes in Wireless Systems." Wireless Personal Communications 72, no. 4 (May 9, 2013): 1827–45. http://dx.doi.org/10.1007/s11277-013-1098-8.

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19

Alay, Özgü, Pei Liu, Yao Wang, Elza Erkip, and Shivendra S. Panwar. "Cooperative Layered Video Multicast Using Randomized Distributed Space Time Codes." IEEE Transactions on Multimedia 13, no. 5 (October 2011): 1127–40. http://dx.doi.org/10.1109/tmm.2011.2158088.

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20

Matache, A., and R. D. Wesel. "Correction to "Universal trellis codes for diagonally layered space-time systems"." IEEE Transactions on Signal Processing 53, no. 8 (August 2005): 3348. http://dx.doi.org/10.1109/tsp.2005.851182.

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21

El-Hajjar, Mohammed, Osamah Alamri, Jin Wang, Salam Zummo, and Lajos Hanzo. "Layered steered space-time codes using multi-dimensional sphere packing modulation." IEEE Transactions on Wireless Communications 8, no. 7 (July 2009): 3335–40. http://dx.doi.org/10.1109/twc.2009.071292.

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22

Tao, M., and R. S. Cheng. "Generalized Layered Space–Time Codes for High Data Rate Wireless Communications." IEEE Transactions on Wireless Communications 3, no. 4 (July 2004): 1067–75. http://dx.doi.org/10.1109/twc.2004.828013.

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23

Al-Ghadhban, Samir. "Adaptive Multi-Layered Space-Time Block Coded Systems in Wireless Environments." Wireless Personal Communications 82, no. 2 (December 23, 2014): 799–809. http://dx.doi.org/10.1007/s11277-014-2253-6.

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24

Sungkyu Jung and Jungwoo Lee. "A new ML based interference cancellation technique for layered space-time codes." IEEE Transactions on Communications 57, no. 4 (April 2009): 930–36. http://dx.doi.org/10.1109/tcomm.2009.04.070079.

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25

Lo, Ka Leong, Zhuo Chen, Slavica Marinkovic, and Branka Vucetic. "Layered space-time structures with low-density parity-check and convolutional codes as constituent codes." European Transactions on Telecommunications 16, no. 2 (2005): 121–35. http://dx.doi.org/10.1002/ett.1036.

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26

Kim, Tae-Hun, and Ji-Won Jung. "Optimum Turbo Equalization Method based on Layered Space Time Codes in Underwater Communications." Journal of the Korea Institute of Information and Communication Engineering 18, no. 5 (May 31, 2014): 1042–50. http://dx.doi.org/10.6109/jkiice.2014.18.5.1042.

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27

Yanpeng Wu, Xiaoqi Peng, and Yanpo Song. "A Symbol-wise Ordered Successive Interference Cancellation Detector for Layered Space-Time Block Codes." International Journal of Digital Content Technology and its Applications 5, no. 4 (April 30, 2011): 101–6. http://dx.doi.org/10.4156/jdcta.vol5.issue4.12.

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28

Ebihara, Katsunori, Koji Kamakura, and Takaya Yamazato. "Layered Transmission of Space-Time Coded Signals for Image-Sensor-Based Visible Light Communications." Journal of Lightwave Technology 33, no. 20 (October 15, 2015): 4193–206. http://dx.doi.org/10.1109/jlt.2015.2470091.

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29

Hufei Zhu and Wen Chen. "Comments on "A New ML Based Interference Cancellation Technique for Layered Space-Time Codes"." IEEE Transactions on Communications 58, no. 11 (November 2010): 3054–55. http://dx.doi.org/10.1109/tcomm.2010.083110.100001.

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30

Marinkovic, Slavica, Branka Vucetic, and Joseph Chueh. "Multiuser detection techniques with decision statistics combining for layered space-time coded CDMA systems." European Transactions on Telecommunications 17, no. 4 (2006): 423–38. http://dx.doi.org/10.1002/ett.1085.

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31

XIONG, Fei, Jian-hua ZHANG, and Ping ZHANG. "Layered space time codes and capacity analysis in correlated fading channels with distributed antenna system." Journal of China Universities of Posts and Telecommunications 18, no. 1 (February 2011): 28–35. http://dx.doi.org/10.1016/s1005-8885(10)60024-6.

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32

Park, Tae-Doo, and Ji-Won Jung. "A Study on layered Space Time Trellis codes for MIMO system based on Iterative Decoding Algorithm." Journal of Korean navigation and port research 36, no. 10 (December 31, 2012): 845–49. http://dx.doi.org/10.5394/kinpr.2012.36.10.845.

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33

Berthet, A. O., and R. Visoz. "Iterative decoding of concatenated layered space-time trellis codes on mimo block fading multipath awgn channel." IEEE Transactions on Communications 51, no. 6 (June 2003): 940–52. http://dx.doi.org/10.1109/tcomm.2003.813268.

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34

Shao, Shihai, Youxi Tang, and Wanzhi Ma. "Layered space-time codes over Ricean fading channels by reducing the correlation of spatial shaping pulses." IEEE Transactions on Wireless Communications 8, no. 2 (February 2009): 574–79. http://dx.doi.org/10.1109/twc.2009.071054.

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35

Jeong, Jun H., and Mohsen Kavehrad. "An Iterative Receiver for Uplink of Coded MIMO DS-CDMA System Employing Layered Space-Time Transmission." International Journal of Wireless Information Networks 13, no. 3 (January 4, 2006): 207–20. http://dx.doi.org/10.1007/s10776-005-0022-x.

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36

Cances, J. P., G. R. Mohammadkhani, and V. Meghdadi. "Turbo Interference Mitigation in Layered Space-Time MIMO DS-CDMA Uplink with TTCM(Turbo Trellis Coded Modulation)." Wireless Personal Communications 37, no. 1-2 (April 2006): 105–21. http://dx.doi.org/10.1007/s11277-006-1078-3.

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37

Yousafzai, A. K., and M. R. Nakhai. "Reduced complexity detection technique for layered space time block coded multiple-input multiple-output orthogonal frequency division multiplexing." IET Communications 3, no. 1 (2009): 115. http://dx.doi.org/10.1049/iet-com:20080415.

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38

Huang, Kaiyuan, Yue Xiao, Lizhe Liu, Yong Li, Zhiqun Song, Bin Wang, and Xingjian Li. "Integrated Spatial Modulation and STBC-VBLAST Design toward Efficient MIMO Transmission." Sensors 22, no. 13 (June 22, 2022): 4719. http://dx.doi.org/10.3390/s22134719.

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In this contribution, the concept of spatial modulation (SM) is firstly integrated into the structure of space-time block codes (STBC)-aided vertical Bell-labs layered space-time (VBLAST) systems, in order to strike a balanced tradeoff among bit error ratio (BER), spectral efficiency and computational complexity. First of all, in order to enhance the BER performance of STBC-VBLAST, we advocate an effective transmit power allocation (TPA) scheme with negligible implementation costs, while dividing the STBC and VBLAST layers with alleviated interference, so as to facilitate combination with SM. Then, we further utilize the unique structure of SM for enhancing the spectral efficiency of original STBC-VBLAST, wherein the information is conveyed by not only the amplitude/phase modulation (APM) symbols but also the antenna indices. In addition, constellation sets of STBC symbols are specifically designed to be rotated to make full use of the degrees of freedom. Finally, the performance advantages of the above-mentioned structures over traditional STBC-VBLAST are demonstrated by the theoretical derivation of a closed-form expression for the union bound on the bit error probability for various spectral efficiencies, and they are supported by simulation results.

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39

Lin, Baihan. "Regularity Normalization: Neuroscience-Inspired Unsupervised Attention across Neural Network Layers." Entropy 24, no. 1 (December 28, 2021): 59. http://dx.doi.org/10.3390/e24010059.

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Inspired by the adaptation phenomenon of neuronal firing, we propose the regularity normalization (RN) as an unsupervised attention mechanism (UAM) which computes the statistical regularity in the implicit space of neural networks under the Minimum Description Length (MDL) principle. Treating the neural network optimization process as a partially observable model selection problem, the regularity normalization constrains the implicit space by a normalization factor, the universal code length. We compute this universal code incrementally across neural network layers and demonstrate the flexibility to include data priors such as top-down attention and other oracle information. Empirically, our approach outperforms existing normalization methods in tackling limited, imbalanced and non-stationary input distribution in image classification, classic control, procedurally-generated reinforcement learning, generative modeling, handwriting generation and question answering tasks with various neural network architectures. Lastly, the unsupervised attention mechanisms is a useful probing tool for neural networks by tracking the dependency and critical learning stages across layers and recurrent time steps of deep networks.

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40

Duras, Julia, Oleksander Kalentev, Ralf Schneider, Konstantin Matyash, Karl Felix Lüskow, and Jürgen Geiser. "ELECTROSTATIC ION THRUSTERS - TOWARDS PREDICTIVE MODELING." Acta Polytechnica 55, no. 1 (February 28, 2015): 7–13. http://dx.doi.org/10.14311/ap.2015.55.0007.

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For satellite missions, thrusters have to be qualified in large vacuum vessels to simulate space environment. One caveat of these experiments is the possible modification of the beam properties due to the interaction of the energetic ions with the vessel walls. Impinging ions can produce sputtered impurities or secondary electrons from the wall. These can stream back into the acceleration channel of the thruster and produce co-deposited layers. Over the long operation time of thousands of hours, such layers can modify the optimized geometry and induce changes of the ion beam properties, e.g. broadening of the angular distribution and thrust reduction. To study such effects, a Monte Carlo code for the simulation of the interaction of ion thruster beams with vessel walls was developed. Strategies to overcome sputter limitations by additional baffles are studied with the help of this Monte-Carlo erosion code.<br /><br />

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41

Farzamnia, Ali, Ngu War Hlaing, Lillian Eda Kong, Manas Kumar Haldar, and Tohid Yousefi Rezaii. "Investigation of error performance in network coded MIMO-VBLAST wireless communication systems." Journal of Electrical Engineering 70, no. 4 (August 1, 2019): 273–84. http://dx.doi.org/10.2478/jee-2019-0057.

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Abstract Paper aims to enhance the performance of bit error rate (BER) in wireless communication based on the multiple-input multiple-output (MIMO) system of vertical Bell laboratories layered space-time (VBLAST) algorithm. The VBLAST algorithm uses zero-forcing (ZF) and the minimum mean square error (MMSE) to evaluate the BER of wireless communication. MIMO VBLAST techniques function as an adaptive filter and can minimize the interference and multipath fading in the received signal of the channel. Physical layer network coding (PNC) is a new technique used to exploit the spatial diversity of the MIMO VBLAST system to improve the throughput and performance of wireless communication. The bit-error-rate (BER) of proposed VBLAST MIMO with PNC with binary phase-shift keying (BPSK) and quadrature phase-shift keying (QPSK) modulation over the additive white Gaussian noise and Rayleigh fading channel are analyzed. The performance of both BPSK and QPSK modulation in two and four antennas are compared. From the simulation results, it was found that the proposed scheme MIMO VBLAST PNC has a 45.2 % higher BER performance compared to the traditional MIMO scheme with an increase in the BER using MMSE and ZF respectively in both two and four antennas.

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42

Cockain, Alex. "Temporalities, a Disability Chronotope, and Empathetic Horizons in Still Human." Journal of Literary & Cultural Disability Studies: Volume 15, Issue 1 15, no. 1 (February 1, 2021): 19–37. http://dx.doi.org/10.3828/jlcds.2021.2.

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The article engages with arrangements of time and space and how they conjoin to constitute a disability chronotope that combines with other textual elements to both expand and limit empathetic horizons in Still Human, a film about a physically impaired middle-aged man and his Pilipino foreign domestic helper (FDH), set largely within a Hong Kong public housing estate. The study distinguishes between the text’s declarative and descriptive layers, albeit while recognizing the forced and perhaps violent nature of this division. Structuring the surface of the film are technical codes and a chronological, optimistic, and sometimes humorous overcoming narrative through which protagonists triumph over tragedy. However, the surface of the text is intermittently disturbed by descriptive layers, or figurative currents. Although this troubling content appears peripheral to, and on the margins of, the text, this underlying and seemingly extraneous content is a crucial supplement which may more effectively realize authorial intentions to disclose the protagonists’ humanness and engender empathy than the more prominent technical codes that structure the text’s surface. Such coexisting layers illustrate how texts are stratified and how the content of texts and the intentions of authors are haunted by undecidability.

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43

Wang, Jinpeng, Zhengpeng Ye, Tarun M. Sanders, Bo Li, and Nianyu Zou. "A Novel Linear Antenna Synthesis for Linear Dispersion Codes Based on an Innovative HYBRID Genetic Algorithm." Symmetry 11, no. 9 (September 17, 2019): 1176. http://dx.doi.org/10.3390/sym11091176.

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As far as taking-away of the symmetry constraints is concerned, as a scientifically symmetry problem, the global synthesis for antenna arrays that produce the desired radiation pattern is also a highly nonlinear optimization issue in fact. Besides this, the built criteria offer the reasonable power patterns. The consequent synthesis could be implemented by looking for a nominal pattern. When the criteria are already sufficient, it can simply do the whole synthesis process. To utilize multiple antennae, a method to choose a transmit antenna for the linear dispersion codes (LDC-TAS) is implemented in this paper. The authors used the max–min-post- signal to noise ratio (SNR) criteria to select these optimal transmitting antennae while this dependent, linear receiver is applied to the varying and slow channel. The simulated results illustrate that this max–min-post-SNR criterion outperforms the Bell Labs layered space time transmitting antenna selection (BLAST-TAS) applying the same spectral efficiency than space–time block codes (STBC)-TAS in the environment with low SNR. Furthermore, once the M antennae are selected under the selection criteria, a max–min-post-SNR rule, a novel linear antenna synthesis to linear dispersion codes on the basis of an innovative HYBRID (of mixed characters or solutions) genetic algorithm has been presented and evaluated to formulate and address the optimal problem to non-uniformly spaced and linear arrays. The restricted side-lobes level, the main-lobe width, and the shaped beam pattern are contemporarily concerned via maximizing a pretty suitable cost function through the innovational advanced genetic-algorithm-based algorithm. The method proposed in this paper can provide flexibility and a simple insertion of the a priori knowledge under a small computing pressure. At last, a computing simulation is completed well and the results are shown. It should be noticed that some extensions of the presented method could also be easily utilized without an obvious increase in the algorithm complexity.

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ZHAO, Z. D., LI MA, and E. C. SHANG. "MODELING OF GREEN'S FUNCTION WITH BOTTOM REFLECTIVE PARAMETERS (P, Q) INSTEAD OF GA PARAMETERS." Journal of Computational Acoustics 22, no. 01 (March 2014): 1440005. http://dx.doi.org/10.1142/s0218396x14400050.

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In shallow-water acoustic waveguide, the bottom of the sea (as the boundary condition that determines the Green's function of the sound propagation) plays an extremely important role in the sound field in water medium, especially at low frequency. Commonly the bottom is characterized by geoacoustic (GA) parameters and nearly all the existing numerical codes for sound field prediction use the GA parameters as the input of the bottom. However, the GA parameters are model based (needs a specified layered bottom model to mount the parameters in) which in practical applications may cause a series of problems such as model mismatching, extra uncertainty for field prediction and time consuming in MFP inverting. When the two bottom reflective parameters (P, Q) are used instead of GA parameters, which are model-free and directly determine the effect of the bottom on the sound field respectively in phase and strength, those problems will be solved naturally. In this paper, for range-independent waveguide using (P, Q) directly as input to construct the Green's function in terms of normal mode field is fully developed. For range-dependent waveguide, we propose an effective-equivalence based mapping between the bottom reflective parameters (P, Q) and the effective half-space (EHS) GA parameters to make (P, Q) as input parameters indirectly. Then all the existed numerical codes can still be used for the calculation of sound field without any modification except using P and Q as the input parameters of the bottom. The accuracy of this mapping is verified for both range-independent and range-dependent waveguide. At last the uncertainty analysis in GA space as well as in PQ space is briefly discussed to reveal the "extra uncertainty" due to the inter-coupling among the GA parameters.

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Kamata, Hiromichi, Yusuke Mukuta, and Tatsuya Harada. "Fully Spiking Variational Autoencoder." Proceedings of the AAAI Conference on Artificial Intelligence 36, no. 6 (June 28, 2022): 7059–67. http://dx.doi.org/10.1609/aaai.v36i6.20665.

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Spiking neural networks (SNNs) can be run on neuromorphic devices with ultra-high speed and ultra-low energy consumption because of their binary and event-driven nature. Therefore, SNNs are expected to have various applications, including as generative models being running on edge devices to create high-quality images. In this study, we build a variational autoencoder (VAE) with SNN to enable image generation. VAE is known for its stability among generative models; recently, its quality advanced. In vanilla VAE, the latent space is represented as a normal distribution, and floating-point calculations are required in sampling. However, this is not possible in SNNs because all features must be binary time series data. Therefore, we constructed the latent space with an autoregressive SNN model, and randomly selected samples from its output to sample the latent variables. This allows the latent variables to follow the Bernoulli process and allows variational learning. Thus, we build the Fully Spiking Variational Autoencoder where all modules are constructed with SNN. To the best of our knowledge, we are the first to build a VAE only with SNN layers. We experimented with several datasets, and confirmed that it can generate images with the same or better quality compared to conventional ANNs. The code is available at https://github.com/kamata1729/FullySpikingVAE.

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Pickett, J. S., L. J. Chen, O. Santolík, S. Grimald, B. Lavraud, O. P. Verkhoglyadova, B. T. Tsurutani, et al. "Electrostatic solitary waves in current layers: from Cluster observations during a super-substorm to beam experiments at the LAPD." Nonlinear Processes in Geophysics 16, no. 3 (June 25, 2009): 431–42. http://dx.doi.org/10.5194/npg-16-431-2009.

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Abstract. Electrostatic Solitary Waves (ESWs) have been observed by several spacecraft in the current layers of Earth's magnetosphere since 1982. ESWs are manifested as isolated pulses (one wave period) in the high time resolution waveform data obtained on these spacecraft. They are thus nonlinear structures generated out of nonlinear instabilities and processes. We report the first observations of ESWs associated with the onset of a super-substorm that occurred on 24 August 2005 while the Cluster spacecraft were located in the magnetotail at around 18–19 RE and moving northward from the plasma sheet to the lobes. These ESWs were detected in the waveform data of the WBD plasma wave receiver on three of the Cluster spacecraft. The majority of the ESWs were detected about 5 min after the super-substorm onset during which time 1) the PEACE electron instrument detected significant field-aligned electron fluxes from a few 100 eV to 3.5 keV, 2) the EDI instrument detected bursts of field-aligned electron currents, 3) the FGM instrument detected substantial magnetic fluctuations and the presence of Alfvén waves, 4) the STAFF experiment detected broadband electric and magnetic waves, ion cyclotron waves and whistler mode waves, and 5) CIS detected nearly comparable densities of H+ and O+ ions and a large tailward H+ velocity. We compare the characteristics of the ESWs observed during this event to those created in the laboratory at the University of California-Los Angeles Plasma Device (LAPD) with an electron beam. We find that the time durations of both space and LAPD ESWs are only slightly larger than the respective local electron plasma periods, indicating that electron, and not ion, dynamics are responsible for generation of the ESWs. We have discussed possible mechanisms for generating the ESWs in space, including the beam and kinetic Buneman type instabilities and the acoustic instabilities. Future studies will examine these mechanisms in more detail using the space measurements as inputs to models, and better relate the ESW space measurements to the laboratory through PIC code models.

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SCHÜTZE, STEPHAN. "The creation of an audio environment as part of a computer game world: the design for Jurassic Park – Operation Genesis on the XBOX™ as a broad concept for surround installation creation." Organised Sound 8, no. 2 (August 2003): 171–80. http://dx.doi.org/10.1017/s1355771803000074.

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The ability to create a virtual world in computer code and implement audio that will follow the physical laws of that real world provides enormous flexibility to the composers working in the computer game industry. The multiple layers of sound that are nonlinear, interactive and dynamically mixed and effected in real time, place this media well outside the restrictions of traditional film, television and music and allow for experiences difficult to create in a more traditional real-world setting. The process of designing a broad concept audio environment for a computer game world can become a blueprint for the creation of a surround sound experience that has many similarities to sound installation practice. Creation and implementation of the sound content, the way in which it becomes interactive and the rules that drive the dynamic mixing are the processes by which the artist defines his or her vision of the final sound work. This paper aims to approach the use of a ‘next generation’ game console as a sound installation space, and discusses the ways in which a virtual audio environment created for a computer game is similar to a more traditional installation space. There are very real limitations for the implementation of soundscapes on computer game consoles, but a balance to these limitations is the capabilities of the surround sound hardware, support of powerful 3D audio engines and accessibility to a wide and diversified audience.

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Mhaske, Swapnil, Hojin Kee, Tai Ly, Ahsan Aziz, and Predrag Spasojevic. "FPGA-Based Channel Coding Architectures for 5G Wireless Using High-Level Synthesis." International Journal of Reconfigurable Computing 2017 (2017): 1–23. http://dx.doi.org/10.1155/2017/3689308.

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We propose strategies to achieve a high-throughput FPGA architecture for quasi-cyclic low-density parity-check codes based on circulant-1 identity matrix construction. By splitting the node processing operation in the min-sum approximation algorithm, we achieve pipelining in the layered decoding schedule without utilizing additional hardware resources. High-level synthesis compilation is used to design and develop the architecture on the FPGA hardware platform. To validate this architecture, an IEEE 802.11n compliant 608 Mb/s decoder is implemented on the Xilinx Kintex-7 FPGA using the LabVIEW FPGA Compiler in the LabVIEW Communication System Design Suite. Architecture scalability was leveraged to accomplish a 2.48 Gb/s decoder on a single Xilinx Kintex-7 FPGA. Further, we present rapidly prototyped experimentation of an IEEE 802.16 compliant hybrid automatic repeat request system based on the efficient decoder architecture developed. In spite of the mixed nature of data processing—digital signal processing and finite-state machines—LabVIEW FPGA Compiler significantly reduced time to explore the system parameter space and to optimize in terms of error performance and resource utilization. A 4x improvement in the system throughput, relative to a CPU-based implementation, was achieved to measure the error-rate performance of the system over large, realistic data sets using accelerated, in-hardware simulation.

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Huang, Xin, Changchun Yin, Colin G. Farquharson, Xiaoyue Cao, Bo Zhang, Wei Huang, and Jing Cai. "Spectral-element method with arbitrary hexahedron meshes for time-domain 3D airborne electromagnetic forward modeling." GEOPHYSICS 84, no. 1 (January 1, 2019): E37—E46. http://dx.doi.org/10.1190/geo2018-0231.1.

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Mainstream numerical methods for 3D time-domain airborne electromagnetic (AEM) modeling, such as the finite-difference (FDTD) or finite-element (FETD) methods, are quite mature. However, these methods have limitations in terms of their ability to handle complex geologic structures and their dependence on quality meshing of the earth model. We have developed a time-domain spectral-element (SETD) method based on the mixed-order spectral-element (SE) approach for space discretization and the backward Euler (BE) approach for time discretization. The mixed-order SE approach can contribute an accurate result by increasing the order of polynomials and suppress spurious solutions. The BE method is an unconditionally stable technique without limitations on time steps. To deal with the rapid variation of the fields close to the AEM transmitting loop, we separate a secondary field from the primary field and simulate the secondary field only, for which the primary field is calculated in advance. To obtain a block diagonal mass matrix and hence minimize the number of nonzero elements in the system of equations to be solved, we apply Gauss-Lobatto-Legendre integral techniques of reduced order. A direct solver is then adopted for the system of equations, which allows for efficient treatment of the multiple AEM sources. To check the accuracy of our SETD algorithm, we compare our results with the semianalytical solution for a layered earth model. Then, we analyze the modeling accuracy and efficiency for different 3D models using deformed physical meshes and compare them against results from 3D FETD codes, to further show the flexibility of SETD for AEM forward modeling.

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Al-Bahadili, Hussein, and Saif Al-Saab. "Development of a Novel Compressed Index-Query Web Search Engine Model." International Journal of Information Technology and Web Engineering 6, no. 3 (July 2011): 39–56. http://dx.doi.org/10.4018/jitwe.2011070103.

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In this paper, the authors present a description of a new Web search engine model, the compressed index-query (CIQ) Web search engine model. This model incorporates two bit-level compression layers implemented at the back-end processor (server) side, one layer resides after the indexer acting as a second compression layer to generate a double compressed index (index compressor), and the second layer resides after the query parser for query compression (query compressor) to enable bit-level compressed index-query search. The data compression algorithm used in this model is the Hamming codes-based data compression (HCDC) algorithm, which is an asymmetric, lossless, bit-level algorithm permits CIQ search. The different components of the new Web model are implemented in a prototype CIQ test tool (CIQTT), which is used as a test bench to validate the accuracy and integrity of the retrieved data and evaluate the performance of the proposed model. The test results demonstrate that the proposed CIQ model reduces disk space requirements and searching time by more than 24%, and attains a 100% agreement when compared with an uncompressed model.

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