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Sample records for wiring viterbi decoders

  1. High Speed Viterbi Decoder Architecture

    DEFF Research Database (Denmark)

    Paaske, Erik; Andersen, Jakob Dahl

    1998-01-01

    The fastest commercially available Viterbi decoders for the (171,133) standard rate 1/2 code operate with a decoding speed of 40-50 Mbit/s (net data rate). In this paper we present a suitable architecture for decoders operating with decoding speeds of 150-300 Mbit/s....

  2. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1998-01-01

    The study has been divided into two phases. The purpose of Phase 1 of the study was to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. After selection of which specific...... potentially useful.Algorithms for frame synchronization are described and analyzed. Further, the high level architecture of units that contain frame synchronization and various other functions needed in a complete system is presented. Two such units are described, one for placement before the Viterbi decoder...... towards a realization in an FPGA.Node synchronization performed within a Viterbi decoder is discussed, and the high level architectures of three possible implementations of Viterbi decoders are described: The first implementation uses a number of commercially available decoders while the the two others...

  3. FPGA Realization of Memory 10 Viterbi Decoder

    DEFF Research Database (Denmark)

    Paaske, Erik; Bach, Thomas Bo; Andersen, Jakob Dahl

    1997-01-01

    sequence mode when feedback from the Reed-Solomon decoder is available. The Viterbi decoder is realized using two Altera FLEX 10K50 FPGA's. The overall operating speed is 30 kbit/s, and since up to three iterations are performed for each frame and only one decoder is used, the operating speed...

  4. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1996-01-01

    The purpose of Phase 1 of the study is to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. The systems we consider are high data rate space communication systems. Also...... components. Node synchronization performed within a Viterbi decoder is discussed, and algorithms for frame synchronization are described and analyzed. We present a list of system configurations that we find potentially useful. Further, the high level architecture of units that contain frame synchronization...

  5. Interleaved Convolutional Code and Its Viterbi Decoder Architecture

    National Research Council Canada - National Science Library

    Kong, Jun Jin; Parhi, Keshab K

    2003-01-01

    We propose an area-efficient high-speed interleaved Viterbi decoder architecture, which is based on the state-parallel architecture with register exchange path memory structure, for interleaved convolutional code...

  6. Interleaved Convolutional Code and Its Viterbi Decoder Architecture

    Directory of Open Access Journals (Sweden)

    Kong Jun Jin

    2003-01-01

    Full Text Available We propose an area-efficient high-speed interleaved Viterbi decoder architecture, which is based on the state-parallel architecture with register exchange path memory structure, for interleaved convolutional code. The state-parallel architecture uses as many add-compare-select (ACS units as the number of trellis states. By replacing each delay (or storage element in state metrics memory (or path metrics memory and path memory (or survival memory with delays, interleaved Viterbi decoder is obtained where is the interleaving degree. The decoding speed of this decoder architecture is as fast as the operating clock speed. The latency of proposed interleaved Viterbi decoder is “decoding depth (DD interleaving degree ,” which increases linearly with the interleaving degree .

  7. Convolutional Encoder and Viterbi Decoder Using SOPC For Variable Constraint Length

    DEFF Research Database (Denmark)

    Kulkarni, Anuradha; Dnyaneshwar, Mantri; Prasad, Neeli R.

    2013-01-01

    detailed analysis, this paper deals with the implementation of convolution encoder and Viterbi decoder using system on programming chip (SOPC). It uses variable constraint length of 7, 8 and 9 bits for 1/2 and 1/3 code rates. By analyzing the Viterbi algorithm it is seen that our algorithm has a better......Convolution encoder and Viterbi decoder are the basic and important blocks in any Code Division Multiple Accesses (CDMA). They are widely used in communication system due to their error correcting capability But the performance degrades with variable constraint length. In this context to have...

  8. A HARDWARE IMPLEMENTATION OF PUNCTURED CONVOLUTIONAL CODES TO COMPLETE A VITERBI DECODER CORE

    OpenAIRE

    E. García,; Torres, D.; Guzmán, M.

    2005-01-01

    This paper presents a VLSI (Very Large Scale Integration) implementation of high punctured convolutional codes.We present a new circuit architecture that is capable of processing up to 10 convolutional codes rate (n-1)/n withthe constraint length-7 derived by the puncturing technique from the basic rate-1/2. The present circuit wasdesigned in order to complete an existing Viterbi decoder core, adding some extra functionality such as aconvolutional encoder, differential encoder/decoder, punctu...

  9. Joint Synchronization Of Viterbi And Reed-Solomon Decoders

    Science.gov (United States)

    Statman, Joseph I.; Chauvin, Todd H.; Cheung, Kar-Ming; Rabkin, Jay; Belongie, Mignon L.

    1995-01-01

    Synchronization times reduced to reduce loss of data. Scheme for decoding received doubly encoded binary-data signal provides for joint synchronization of two decoders. Applies to concatenated error-correcting channel coding communication system in which, at transmitter, data first encoded by interleaved Reed-Solomon code (block code), then by convolutional code.

  10. Systolic array architecture for convolutional decoding algorithms: Viterbi algorithm and stack algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.Y.

    1986-01-01

    New results on efficient forms of decoding convolutional codes based on Viterbi and stack algorithms using systolic array architecture are presented. Some theoretical aspects of systolic arrays are also investigated. First, systolic array implementation of Viterbi algorithm is considered, and various properties of convolutional codes are derived. A technique called strongly connected trellis decoding is introduced to increase the efficient utilization of all the systolic array processors. The issues dealing with the composite branch metric generation, survivor updating, overall system architecture, throughput rate, and computations overhead ratio are also investigated. Second, the existing stack algorithm is modified and restated in a more concise version so that it can be efficiently implemented by a special type of systolic array called systolic priority queue. Three general schemes of systolic priority queue based on random access memory, shift register, and ripple register are proposed. Finally, a systematic approach is presented to design systolic arrays for certain general classes of recursively formulated algorithms.

  11. Quantum Public-Key Cryptography and Quantum Circuits of Viterbi Decoding

    OpenAIRE

    横尾, 隆文; 清野, 光弘; Yokoo, Takafumi; Seino, Mitsuhiro

    2014-01-01

    The quantum circuits to generate the public-key determined by OTU2000 are suggested. The quantum circuits structured by n units for Shor's algorithm are discussed. Public-keys calculated by the quantum computer implemented quantum circuits proposed in this paper are generated in polynomial time by using discrete logarithm transformation. And the quantum circuits programmed by Grover's algorithm which perform Viterbi decoding processing on the assumption that communications are realized by OTU...

  12. VLSI Architecture for Configurable and Low-Complexity Design of Hard-Decision Viterbi Decoding Algorithm

    Directory of Open Access Journals (Sweden)

    Rachmad Vidya Wicaksana Putra

    2016-06-01

    Full Text Available Convolutional encoding and data decoding are fundamental processes in convolutional error correction. One of the most popular error correction methods in decoding is the Viterbi algorithm. It is extensively implemented in many digital communication applications. Its VLSI design challenges are about area, speed, power, complexity and configurability. In this research, we specifically propose a VLSI architecture for a configurable and low-complexity design of a hard-decision Viterbi decoding algorithm. The configurable and low-complexity design is achieved by designing a generic VLSI architecture, optimizing each processing element (PE at the logical operation level and designing a conditional adapter. The proposed design can be configured for any predefined number of trace-backs, only by changing the trace-back parameter value. Its computational process only needs N + 2 clock cycles latency, with N is the number of trace-backs. Its configurability function has been proven for N = 8, N = 16, N = 32 and N = 64. Furthermore, the proposed design was synthesized and evaluated in Xilinx and Altera FPGA target boards for area consumption and speed performance.

  13. An Asynchronous Low Power and High Performance VLSI Architecture for Viterbi Decoder Implemented with Quasi Delay Insensitive Templates

    OpenAIRE

    T. Kalavathi Devi; Sakthivel Palaniappan

    2015-01-01

    Convolutional codes are comprehensively used as Forward Error Correction (FEC) codes in digital communication systems. For decoding of convolutional codes at the receiver end, Viterbi decoder is often used to have high priority. This decoder meets the demand of high speed and low power. At present, the design of a competent system in Very Large Scale Integration (VLSI) technology requires these VLSI parameters to be finely defined. The proposed asynchronous method focuses on reducing the powe...

  14. Choosing channel quantization levels and viterbi decoding for space diversity reception over the additive white Guassian noise channel

    Science.gov (United States)

    Kalson, S.

    1986-01-01

    Previous work in the area of choosing channel quantization levels for a additive white Gaussian noise channel composed of one receiver-demodulator is reviewed, and how this applies to the Deep Space Network composed of several receiver-demodulators (space diversity reception) is shown. Viterbi decoding for the resulting quantized channel is discussed.

  15. Minimum decoding trellis length and truncation depth of wrap-around Viterbi algorithm for TBCC in mobile WiMAX

    Directory of Open Access Journals (Sweden)

    Liu Yu-Sun

    2011-01-01

    Full Text Available Abstract The performance of the wrap-around Viterbi decoding algorithm with finite truncation depth and fixed decoding trellis length is investigated for tail-biting convolutional codes in the mobile WiMAX standard. Upper bounds on the error probabilities induced by finite truncation depth and the uncertainty of the initial state are derived for the AWGN channel. The truncation depth and the decoding trellis length that yield negligible performance loss are obtained for all transmission rates over the Rayleigh channel using computer simulations. The results show that the circular decoding algorithm with an appropriately chosen truncation depth and a decoding trellis just a fraction longer than the original received code words can achieve almost the same performance as the optimal maximum likelihood decoding algorithm in mobile WiMAX. A rule of thumb for the values of the truncation depth and the trellis tail length is also proposed.

  16. A HARDWARE IMPLEMENTATION OF PUNCTURED CONVOLUTIONAL CODES TO COMPLETE A VITERBI DECODER CORE

    Directory of Open Access Journals (Sweden)

    E. García,

    2005-08-01

    Full Text Available This paper presents a VLSI (Very Large Scale Integration implementation of high punctured convolutional codes.We present a new circuit architecture that is capable of processing up to 10 convolutional codes rate (n-1/n withthe constraint length-7 derived by the puncturing technique from the basic rate-1/2. The present circuit wasdesigned in order to complete an existing Viterbi decoder core, adding some extra functionality such as aconvolutional encoder, differential encoder/decoder, punctured convolutional encoder and symbol insertion todepuncture the received data. This extra functionality includes 10 different programmable coding rates without theneed to add additional logic in the system implementation, while other existing coders need it to attain highercoding rates. Therefore, a single chip solution is presented. The design was implemented in VHDL (Very High SpeedIntegrated Circuit Hardware Description Language synthesized in Synopsys tool, and tested in a FPGA. Functionalverification was done, by means of simulation, to ensure that the circuit implements intended functionality. Suchsimulations were executed using Synopsys and a Sun Ultra Sparc 10 workstation. Different bit error probabilityperformance curves show an agreement between simulated and theoretical values.

  17. Design and Implementation of Convolutional Encoder and Viterbi Decoder Using FPGA.

    Directory of Open Access Journals (Sweden)

    Riham Ali Zbaid

    2018-01-01

    Full Text Available Keeping  the  fineness of data is the most significant thing in communication.There are many factors that affect the accuracy of the data when it is transmitted over the communication channel such as noise etc. to overcome these effects are encoding channels encryption.In this paper is used for one type of channel coding is convolutional codes. Convolution encoding is a Forward Error Correction (FEC method used in incessant one-way and real time communication links .It can offer a great development in the error bit rates so that small, low energy, and devices cheap transmission when used in applications such as satellites. In this paper highlight the design, simulation and implementation of convolution encoder and Viterbi decoder by using MATLAB- program (2011. SIMULINK HDL coder is used to convert MATLAB-SIMULINK models to VHDL using plates Altera Cyclone II code DE2-70. Simulation and evaluation of the implementation of the results coincided with the results of the design show the coinciding with the designed results.

  18. An Asynchronous Low Power and High Performance VLSI Architecture for Viterbi Decoder Implemented with Quasi Delay Insensitive Templates.

    Science.gov (United States)

    Devi, T Kalavathi; Palaniappan, Sakthivel

    2015-01-01

    Convolutional codes are comprehensively used as Forward Error Correction (FEC) codes in digital communication systems. For decoding of convolutional codes at the receiver end, Viterbi decoder is often used to have high priority. This decoder meets the demand of high speed and low power. At present, the design of a competent system in Very Large Scale Integration (VLSI) technology requires these VLSI parameters to be finely defined. The proposed asynchronous method focuses on reducing the power consumption of Viterbi decoder for various constraint lengths using asynchronous modules. The asynchronous designs are based on commonly used Quasi Delay Insensitive (QDI) templates, namely, Precharge Half Buffer (PCHB) and Weak Conditioned Half Buffer (WCHB). The functionality of the proposed asynchronous design is simulated and verified using Tanner Spice (TSPICE) in 0.25 µm, 65 nm, and 180 nm technologies of Taiwan Semiconductor Manufacture Company (TSMC). The simulation result illustrates that the asynchronous design techniques have 25.21% of power reduction compared to synchronous design and work at a speed of 475 MHz.

  19. An Asynchronous Low Power and High Performance VLSI Architecture for Viterbi Decoder Implemented with Quasi Delay Insensitive Templates

    Directory of Open Access Journals (Sweden)

    T. Kalavathi Devi

    2015-01-01

    Full Text Available Convolutional codes are comprehensively used as Forward Error Correction (FEC codes in digital communication systems. For decoding of convolutional codes at the receiver end, Viterbi decoder is often used to have high priority. This decoder meets the demand of high speed and low power. At present, the design of a competent system in Very Large Scale Integration (VLSI technology requires these VLSI parameters to be finely defined. The proposed asynchronous method focuses on reducing the power consumption of Viterbi decoder for various constraint lengths using asynchronous modules. The asynchronous designs are based on commonly used Quasi Delay Insensitive (QDI templates, namely, Precharge Half Buffer (PCHB and Weak Conditioned Half Buffer (WCHB. The functionality of the proposed asynchronous design is simulated and verified using Tanner Spice (TSPICE in 0.25 µm, 65 nm, and 180 nm technologies of Taiwan Semiconductor Manufacture Company (TSMC. The simulation result illustrates that the asynchronous design techniques have 25.21% of power reduction compared to synchronous design and work at a speed of 475 MHz.

  20. An area-efficient path memory structure for VLSI Implementation of high speed Viterbi decoders

    DEFF Research Database (Denmark)

    Paaske, Erik; Pedersen, Steen; Sparsø, Jens

    1991-01-01

    area savings compared to the REA and the TBA are achieved. Furthermore, the relative area savings increase for larger decoding depths, which might be desirable for punctured codes.Based on the new algorithm a test chip has been designed and fabricated in a 2 micron CMOS process using MOSIS like...

  1. Enhanced 2/3 four-ary modulation code using soft-decision Viterbi decoding for four-level holographic data storage systems

    Science.gov (United States)

    Kong, Gyuyeol; Choi, Sooyong

    2017-09-01

    An enhanced 2/3 four-ary modulation code using soft-decision Viterbi decoding is proposed for four-level holographic data storage systems. While the previous four-ary modulation codes focus on preventing maximum two-dimensional intersymbol interference patterns, the proposed four-ary modulation code aims at maximizing the coding gains for better bit error rate performances. For achieving significant coding gains from the four-ary modulation codes, we design a new 2/3 four-ary modulation code in order to enlarge the free distance on the trellis through extensive simulation. The free distance of the proposed four-ary modulation code is extended from 1.21 to 2.04 compared with that of the conventional four-ary modulation code. The simulation result shows that the proposed four-ary modulation code has more than 1 dB gains compared with the conventional four-ary modulation code.

  2. Adaptive decoding of convolutional codes

    Directory of Open Access Journals (Sweden)

    K. Hueske

    2007-06-01

    Full Text Available Convolutional codes, which are frequently used as error correction codes in digital transmission systems, are generally decoded using the Viterbi Decoder. On the one hand the Viterbi Decoder is an optimum maximum likelihood decoder, i.e. the most probable transmitted code sequence is obtained. On the other hand the mathematical complexity of the algorithm only depends on the used code, not on the number of transmission errors. To reduce the complexity of the decoding process for good transmission conditions, an alternative syndrome based decoder is presented. The reduction of complexity is realized by two different approaches, the syndrome zero sequence deactivation and the path metric equalization. The two approaches enable an easy adaptation of the decoding complexity for different transmission conditions, which results in a trade-off between decoding complexity and error correction performance.

  3. Improved decoding for a concatenated coding system

    DEFF Research Database (Denmark)

    Paaske, Erik

    1990-01-01

    The concatenated coding system recommended by CCSDS (Consultative Committee for Space Data Systems) uses an outer (255,233) Reed-Solomon (RS) code based on 8-b symbols, followed by the block interleaver and an inner rate 1/2 convolutional code with memory 6. Viterbi decoding is assumed. Two new...

  4. Design of a new squaring function for the Viterbi algorithm

    Science.gov (United States)

    Eshraghi, Aria; Fiez, Terri; Fischer, Thomas; Winters, Kel

    1992-01-01

    A new algorithm and hardware implementation of the Viterbi squaring function was developed. The use of an approximation squaring technique preserves the Viterbi performance as is demonstrated by Monte-Carlo simulations. Additionally, the 16-bit approximate squaring implementation is expected to require one-fourth the area and operate at three times the speed of the conventional squaring implementation.

  5. A General Rate K/N Convolutional Decoder Based on Neural Networks with Stopping Criterion

    Directory of Open Access Journals (Sweden)

    Johnny W. H. Kao

    2009-01-01

    Full Text Available A novel algorithm for decoding a general rate K/N convolutional code based on recurrent neural network (RNN is described and analysed. The algorithm is introduced by outlining the mathematical models of the encoder and decoder. A number of strategies for optimising the iterative decoding process are proposed, and a simulator was also designed in order to compare the Bit Error Rate (BER performance of the RNN decoder with the conventional decoder that is based on Viterbi Algorithm (VA. The simulation results show that this novel algorithm can achieve the same bit error rate and has a lower decoding complexity. Most importantly this algorithm allows parallel signal processing, which increases the decoding speed and accommodates higher data rate transmission. These characteristics are inherited from a neural network structure of the decoder and the iterative nature of the algorithm, that outperform the conventional VA algorithm.

  6. Linewidth tolerance of digital coherent receiver using Viterbi & Viterbi RF carrier recovery for radio-over-fibre links

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Zibar, Darko; Larsen, Knud J.

    2009-01-01

    for phase-modulated RoF optical links (2). The RF signal processing in (2) is performed using maximum likelihood RF carrier phase estimation (2). In this paper, we investigate the performance of the proposed digital coherent receiver in (2) using feedforward Viterbi & Viterbi RF carrier recovery algorithm......Transport and distribution of wireless signals over fibre, so called Radio-over-Fibre (RoF), is an important technology in order to realize converged fibre-optic and wireless networks (1). Recently, we have proposed and experimentally demonstrated a novel DSP based digital coherent receiver...

  7. Reduced-computation trellis decoder with inherent parallelism

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, S.J.

    1986-01-01

    A new breadth-first trellis decoding algorithms is introduced for application to sequence estimation in digital data transmission. The high degree of inherent parallelism and simple data flow make a parallel processing implementation attractive. The proposed algorithm is shown to exhibit an error-rate vs. average computational complexity behavior superior to that of the well-known Viterbi algorithm. The decoding algorithm uses recursively calculated path metrics common to trellis decoding. The threshold rule used causes the number of survivor paths to adapt to the channel noise actually encountered. The low average decoding load is exploited by assigning computational capability just in excess of the average requirement, and buffering the received signal samples. Bounds on the event-error rate and average number of survivors are produced, and efficient trellis search procedures are devised for their evaluation. Performance is tested for the AWGN channel with new multi-level codes, conventional binary convolutional codes, and simple intersymbol interference responses.

  8. Neural speech recognition: continuous phoneme decoding using spatiotemporal representations of human cortical activity

    Science.gov (United States)

    Moses, David A.; Mesgarani, Nima; Leonard, Matthew K.; Chang, Edward F.

    2016-10-01

    Objective. The superior temporal gyrus (STG) and neighboring brain regions play a key role in human language processing. Previous studies have attempted to reconstruct speech information from brain activity in the STG, but few of them incorporate the probabilistic framework and engineering methodology used in modern speech recognition systems. In this work, we describe the initial efforts toward the design of a neural speech recognition (NSR) system that performs continuous phoneme recognition on English stimuli with arbitrary vocabulary sizes using the high gamma band power of local field potentials in the STG and neighboring cortical areas obtained via electrocorticography. Approach. The system implements a Viterbi decoder that incorporates phoneme likelihood estimates from a linear discriminant analysis model and transition probabilities from an n-gram phonemic language model. Grid searches were used in an attempt to determine optimal parameterizations of the feature vectors and Viterbi decoder. Main results. The performance of the system was significantly improved by using spatiotemporal representations of the neural activity (as opposed to purely spatial representations) and by including language modeling and Viterbi decoding in the NSR system. Significance. These results emphasize the importance of modeling the temporal dynamics of neural responses when analyzing their variations with respect to varying stimuli and demonstrate that speech recognition techniques can be successfully leveraged when decoding speech from neural signals. Guided by the results detailed in this work, further development of the NSR system could have applications in the fields of automatic speech recognition and neural prosthetics.

  9. Comparative investigation into Viterbi based and multiple hypothesis based track stitching

    CSIR Research Space (South Africa)

    Van der Merwe, LJ

    2016-12-01

    Full Text Available In this study a comparative analysis is performed between a novel Viterbi based and multiple hypothesis based track stitching algorithms. The track fragments in the Viterbi based track stitching algorithm are modelled as nodes in a trellis structure...

  10. Performance Analysis of M-QAM With Viterbi Soft-Decision Decoding

    National Research Council Canada - National Science Library

    Manso, Rogerio

    2003-01-01

    ...) in Additive White Gaussian Noise (AWGN) and Nakagami-m channels. Performance analyses for 16-QAM, 64-QAM, QPSK and BPSK associated with up to three convolutional codes, including the one used by the IEEE...

  11. A Fully Parallel VLSI-implementation of the Viterbi Decoding Algorithm

    DEFF Research Database (Denmark)

    Sparsø, Jens; Jørgensen, Henrik Nordtorp; Paaske, Erik

    1989-01-01

    or different values of K. The Shuffle-Exchange type interconnection network is implemented by organizing the 64 processing elements to form a ring. The ring is laid out in two columns, and the interconnections between non-neighbours are routed in the channel between the columns. The interconnection network...

  12. Performance Comparisons of Improved Regular Repeat Accumulate (RA and Irregular Repeat Accumulate (IRA Turbo Decoding

    Directory of Open Access Journals (Sweden)

    Ahmed Abdulkadhim Hamad

    2017-08-01

    Full Text Available In this paper, different techniques are used to improve the turbo decoding of regular repeat accumulate (RA and irregular repeat accumulate (IRA codes. The adaptive scaling of a-posteriori information produced by Soft-output Viterbi decoder (SOVA is proposed. The encoded pilots are another scheme that applied for short length RA codes. This work also suggests a simple and a fast method to generate a random interleaver having a free 4 cycle Tanner graph. Progressive edge growth algorithm (PEG is also studied and simulated to create the Tanner graphs which have a great girth.

  13. Decoders for MST radars

    Science.gov (United States)

    Woodman, R. F.

    1983-01-01

    Decoding techniques and equipment used by MST radars are described and some recommendations for new systems are presented. Decoding can be done either by software in special-purpose (array processors, etc.) or general-purpose computers or in specially designed digital decoders. Both software and hardware decoders are discussed and the special case of decoding for bistatic radars is examined.

  14. STACK DECODING OF LINEAR BLOCK CODES FOR DISCRETE MEMORYLESS CHANNEL USING TREE DIAGRAM

    Directory of Open Access Journals (Sweden)

    H. Prashantha Kumar

    2012-03-01

    Full Text Available The boundaries between block and convolutional codes have become diffused after recent advances in the understanding of the trellis structure of block codes and the tail-biting structure of some convolutional codes. Therefore, decoding algorithms traditionally proposed for decoding convolutional codes have been applied for decoding certain classes of block codes. This paper presents the decoding of block codes using tree structure. Many good block codes are presently known. Several of them have been used in applications ranging from deep space communication to error control in storage systems. But the primary difficulty with applying Viterbi or BCJR algorithms to decode of block codes is that, even though they are optimum decoding methods, the promised bit error rates are not achieved in practice at data rates close to capacity. This is because the decoding effort is fixed and grows with block length, and thus only short block length codes can be used. Therefore, an important practical question is whether a suboptimal realizable soft decision decoding method can be found for block codes. A noteworthy result which provides a partial answer to this question is described in the following sections. This result of near optimum decoding will be used as motivation for the investigation of different soft decision decoding methods for linear block codes which can lead to the development of efficient decoding algorithms. The code tree can be treated as an expanded version of the trellis, where every path is totally distinct from every other path. We have derived the tree structure for (8, 4 and (16, 11 extended Hamming codes and have succeeded in implementing the soft decision stack algorithm to decode them. For the discrete memoryless channel, gains in excess of 1.5dB at a bit error rate of 10-5 with respect to conventional hard decision decoding are demonstrated for these codes.

  15. Decoding of Cyclic Codes,

    Science.gov (United States)

    INFORMATION THEORY, *DECODING), (* DATA TRANSMISSION SYSTEMS , DECODING), STATISTICAL ANALYSIS, STOCHASTIC PROCESSES, CODING, WHITE NOISE, NUMBER THEORY, CORRECTIONS, BINARY ARITHMETIC, SHIFT REGISTERS, CONTROL SYSTEMS, USSR

  16. A Coarse-to-Fine Approach to Computing the k-best Viterbi Paths

    DEFF Research Database (Denmark)

    Nielsen, Jesper

    2011-01-01

    The Hidden Markov Model (HMM) is a probabilistic model used widely in the fields of Bioinformatics and Speech Recognition. Efficient algorithms for solving the most common problems are well known, yet they all have a running time that is quadratic in the number of hidden states, which can...... be problematic for models with very large state spaces. The Viterbi algorithm is used to find the maximum likelihood hidden state sequence, and it has earlier been shown that a coarse-to-fine modification can significantly speed up this algorithm on some models. We propose combining work on a k-best version...... of Viterbi algorithm with the coarse-to-fine framework. This algorithm may be used to approximate the total likelihood of the model, or to evaluate the goodness of the Viterbi path on very large models....

  17. Decoding Codes on Graphs-Probabilistic Decoding

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 2. Decoding Codes on Graphs - Probabilistic Decoding. A S Madhu Aditya Nori. General Article Volume 9 Issue 2 February 2004 pp 39-49. Fulltext. Click here to view fulltext PDF. Permanent link:

  18. Emulating Wired Backhaul with Wireless Network Coding

    DEFF Research Database (Denmark)

    Thomsen, Henning; De Carvalho, Elisabeth; Popovski, Petar

    2014-01-01

    , the uplink traffic to the user, remains identical to the one performed in a wired system. In the broadcast phase, the decoding of the downlink traffic can also be guaranteed to remain identical. Hence, our solution claims an emulation of a wired backhaul with wireless network coding with same performance. We...

  19. Forced Sequence Sequential Decoding

    DEFF Research Database (Denmark)

    Jensen, Ole Riis

    In this thesis we describe a new concatenated decoding scheme based on iterations between an inner sequentially decoded convolutional code of rate R=1/4 and memory M=23, and block interleaved outer Reed-Solomon codes with non-uniform profile. With this scheme decoding with good performance is pos...

  20. Forced Sequence Sequential Decoding

    DEFF Research Database (Denmark)

    Jensen, Ole Riis; Paaske, Erik

    1998-01-01

    We describe a new concatenated decoding scheme based on iterations between an inner sequentially decoded convolutional code of rate R=1/4 and memory M=23, and block interleaved outer Reed-Solomon (RS) codes with nonuniform profile. With this scheme decoding with good performance is possible as lo...

  1. The Treeterbi and Parallel Treeterbi algorithms: efficient, optimal decoding for ordinary, generalized and pair HMMs

    DEFF Research Database (Denmark)

    Keibler, Evan; Arumugam, Manimozhiyan; Brent, Michael R

    2007-01-01

    MOTIVATION: Hidden Markov models (HMMs) and generalized HMMs been successfully applied to many problems, but the standard Viterbi algorithm for computing the most probable interpretation of an input sequence (known as decoding) requires memory proportional to the length of the sequence, which can......, our pair HMM based cDNA-to-genome aligner. AVAILABILITY: The TWINSCAN/N-SCAN/PAIRAGON open source software package is available from http://genes.cse.wustl.edu....... be prohibitive. Existing approaches to reducing memory usage either sacrifice optimality or trade increased running time for reduced memory. RESULTS: We developed two novel decoding algorithms, Treeterbi and Parallel Treeterbi, and implemented them in the TWINSCAN/N-SCAN gene-prediction system. The worst case...

  2. More accurate recombination prediction in HIV-1 using a robust decoding algorithm for HMMs

    Directory of Open Access Journals (Sweden)

    Brown Daniel G

    2011-05-01

    Full Text Available Abstract Background Identifying recombinations in HIV is important for studying the epidemiology of the virus and aids in the design of potential vaccines and treatments. The previous widely-used tool for this task uses the Viterbi algorithm in a hidden Markov model to model recombinant sequences. Results We apply a new decoding algorithm for this HMM that improves prediction accuracy. Exactly locating breakpoints is usually impossible, since different subtypes are highly conserved in some sequence regions. Our algorithm identifies these sites up to a certain error tolerance. Our new algorithm is more accurate in predicting the location of recombination breakpoints. Our implementation of the algorithm is available at http://www.cs.uwaterloo.ca/~jmtruszk/jphmm_balls.tar.gz. Conclusions By explicitly accounting for uncertainty in breakpoint positions, our algorithm offers more reliable predictions of recombination breakpoints in HIV-1. We also document a new domain of use for our new decoding approach in HMMs.

  3. An area-efficient topology for VLSI implementation of Viterbi decoders and other shuffle-exchange type structures

    DEFF Research Database (Denmark)

    Sparsø, Jens; Jørgensen, Henrik Nordtorp; Paaske, Erik

    1991-01-01

    A topology for single-chip implementation of computing structures based on shuffle-exchange (SE)-type interconnection networks is presented. The topology is suited for structures with a small number of processing elements (i.e. 32-128) whose area cannot be neglected compared to the area required......- mu m CMOS process using MOSIS-like simplified design rules. The chip operates at speeds up to 19 MHz under worst-case conditions (V/sub DD/=4.75 V and T/sub A/=70 degrees C). The core of the chip (excluding pad cells) is 7.8*5.1 mm/sup 2/ and contains approximately 50000 transistors...

  4. ITERATIVE SOVA DECODING OVER SYMMETRIC ALPHA STABLE CHANNELS

    Directory of Open Access Journals (Sweden)

    CHUAN HSIAN, PU

    2012-06-01

    Full Text Available Soft-Output Viterbi Algorithm (SOVA is one type of recovery memory-less Markov Chain and is used widely to decode convolutional codes. Fundamentally, conventional SOVA is designed on the basis of Maximum A-Posteriori probability (MAP under Additive White Gaussian Noise (AWGN interference. Therefore, the use of conventional Gaussian-based SOVA performs inefficiently and generates high BER (Bit Error Rate in the presence of Symmetric Alpha Stable noise SS. The poor performance of the Gaussian-based SOVA can be attributed to the mathematical quadratic cost function of the receiving mechanism. The quadratic cost function at the receiving end is statistically vulnerable and inefficient to guard SOVA component decoder against the entries of the outliers which are superimposed on the transmitted signal from hostile SS channel. The author studies and improves the performance of conventional SOVA with the introduction of Bayesian Cauchy metric calculation. Substantial performance improvement was observed from Mento Carlo Simulation for SOVA running on the platform of parallel turbo codes.

  5. JSATS Decoder Software Manual

    Energy Technology Data Exchange (ETDEWEB)

    Flory, Adam E.; Lamarche, Brian L.; Weiland, Mark A.

    2013-05-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) Decoder is a software application that converts a digitized acoustic signal (a waveform stored in the .bwm file format) into a list of potential JSATS Acoustic MicroTransmitter (AMT) tagcodes along with other data about the signal including time of arrival and signal to noise ratios (SNR). This software is capable of decoding single files, directories, and viewing raw acoustic waveforms. When coupled with the JSATS Detector, the Decoder is capable of decoding in ‘real-time’ and can also provide statistical information about acoustic beacons placed within receive range of hydrophones within a JSATS array. This document details the features and functionality of the software. The document begins with software installation instructions (section 2), followed in order by instructions for decoder setup (section 3), decoding process initiation (section 4), then monitoring of beacons (section 5) using real-time decoding features. The last section in the manual describes the beacon, beacon statistics, and the results file formats. This document does not consider the raw binary waveform file format.

  6. Optimization of MPEG decoding

    DEFF Research Database (Denmark)

    Martins, Bo; Forchhammer, Søren

    1999-01-01

    MPEG-2 video decoding is examined. A unified approach to quality improvement, chrominance upsampling, de-interlacing and superresolution is presented. The information over several frames is combined as part of the processing.......MPEG-2 video decoding is examined. A unified approach to quality improvement, chrominance upsampling, de-interlacing and superresolution is presented. The information over several frames is combined as part of the processing....

  7. Un calcul de Viterbi pour un Modèle de Markov Caché Contraint

    DEFF Research Database (Denmark)

    Petit, Matthieu; Christiansen, Henning

    2009-01-01

    A hidden Markov model (HMM) is a statistical model in which the system being modeled is assumed to be a Markov process with hidden states. This model has been widely used in speech recognition and biological sequence analysis. Viterbi algorithm has been proposed to compute the most probable value....... Several constraint techniques are used to reduce the search of the most probable value of hidden states of a constrained HMM. An implementation based on PRISM, a logic programming language for statistical modeling, is presented....

  8. Ballistic missile precession frequency extraction based on the Viterbi & Kalman algorithm

    Science.gov (United States)

    Wu, Longlong; Xie, Yongjie; Xu, Daping; Ren, Li

    2015-12-01

    Radar Micro-Doppler signatures are of great potential for target detection, classification and recognition. In the mid-course phase, warheads flying outside the atmosphere are usually accompanied by precession. Precession may induce additional frequency modulations on the returned radar signal, which can be regarded as a unique signature and provide additional information that is complementary to existing target recognition methods. The main purpose of this paper is to establish a more actual precession model of conical ballistic missile warhead and extract the precession parameters by utilizing Viterbi & Kalman algorithm, which improving the precession frequency estimation accuracy evidently , especially in low SNR.

  9. Wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  10. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  11. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  12. Decoding Codes on Graphs

    Indian Academy of Sciences (India)

    Computer Science and. Automation, liSe. Their research addresses various aspects of algebraic and combinatorial coding theory. 1 low Density Parity Check ..... lustrating how the variable Xd is decoded. As mentioned earlier, this algorithm runs iteratively. To start with, in the first iteration, only bits in the first level of the ...

  13. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  14. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  15. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  16. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  17. Multiprocessor architecture for multiple path stack sequential decoders

    Energy Technology Data Exchange (ETDEWEB)

    Belanger, N.; Haccoun, D.; Savaria, Y. [Ecole Poytechnique de Montreal, Montreal (Canada)

    1994-02-01

    The Zigangirov-Jelinek (stack) algorithm allows decoding convolutional codes with a small computational effort compared to the optimum Viterbi algorithm. However, it suffers from a variability of the computational effort that is highly undesirable. This paper describes an architecture that implements a multiple-path-like stack algorithm for reducing this variability. This architecture is organized as a linear structure comprising special processors for extending tree nodes, called extenders, and priority stacks for storing nodes in sorted metric order. The architecture is shown to have a good potential for reducing the computational variability without adding much overhead to the system. Simulations have shown that this architecture effectively reduces computational variability as the number of processors increases, even for a relatively large number of extenders. Simulations run for up to 16 extenders have also shown that using 4 to 16 extenders is a good choice. The architecture is also shown to reduce computational variability like the multiple path algorithm does, while having a better time performance. 12 refs.

  18. Stopping Rules for Turbo Decoders

    Science.gov (United States)

    Matache, A.; Dolinar, S.; Pollara, F.

    2000-04-01

    Decoders for turbo codes are iterative in nature, i.e., they have to perform a certain number of iterations before reaching a satisfactory degree of confidence regarding a frame to be decoded. Until now standard turbo decoders have used a fixed number of iterations. In this article, we propose some simple "stopping rules" that can be used to reduce the average number of iterations. This technique offers a trade-off between speed and performance and can provide a significant increase in the average decoding speed while not sacrificing decoder performance. We tested several types of stopping rules for turbo decoders. One type is based on comparing decoded bits (hard bit decisions) with previous decoded bits; a second type is based on comparing reliabilities (soft bit decisions) with a threshold; and a third type uses a cyclic redundancy check (CRC) code applied to hard decoded bits. We simulated turbo decoder performance using these rules (including several variations of t he first two types) and further required that the decoder cease after 20 iterations if the stopping rule is not yet satisfied. Specifically, we analyzed the decoder-error rates and the average number of iterations for each rule. We found that the average number of iterations was roughly between 4 and 7 for a bit signal-to-noise ratio, E_b/N_0, near the "waterfall" threshold, as compared with the 10 fixed iterations used by the current turbo decoder. In addition, the resulting error rates were noticeably lower than those for 10 fixed iterations, and in fact were very nearly equal to the error rates achieved by a decoder using 20 fixed iterations.

  19. Decoding the human genome

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit; Antonerakis, S E

    2002-01-01

    Decoding the Human genome is a very up-to-date topic, raising several questions besides purely scientific, in view of the two competing teams (public and private), the ethics of using the results, and the fact that the project went apparently faster and easier than expected. The lecture series will address the following chapters: Scientific basis and challenges. Ethical and social aspects of genomics.

  20. Loneliness and Interpersonal Decoding Skills.

    Science.gov (United States)

    Zakahi, Walter R.; Goss, Blaine

    1995-01-01

    Finds that the romantic loneliness dimension of the Differential Loneliness Scale is related to decoding ability, and that there are moderate linear relationships among several of the dimensions of the Differential Loneliness Scale, the self-report of listening ability, and participants' view of their own decoding ability. (SR)

  1. Viterbi equalization for long-distance, high-speed underwater laser communication

    Science.gov (United States)

    Hu, Siqi; Mi, Le; Zhou, Tianhua; Chen, Weibiao

    2017-07-01

    In long-distance, high-speed underwater laser communication, because of the strong absorption and scattering processes, the laser pulse is stretched with the increase in communication distance and the decrease in water clarity. The maximum communication bandwidth is limited by laser-pulse stretching. Improving the communication rate increases the intersymbol interference (ISI). To reduce the effect of ISI, the Viterbi equalization (VE) algorithm is used to estimate the maximum-likelihood receiving sequence. The Monte Carlo method is used to simulate the stretching of the received laser pulse and the maximum communication rate at a wavelength of 532 nm in Jerlov IB and Jerlov II water channels with communication distances of 80, 100, and 130 m, respectively. The high-data rate communication performance for the VE and hard-decision algorithms is compared. The simulation results show that the VE algorithm can be used to reduce the ISI by selecting the minimum error path. The trade-off between the high-data rate communication performance and minor bit-error rate performance loss makes VE a promising option for applications in long-distance, high-speed underwater laser communication systems.

  2. Using Wireless Network Coding to Replace a Wired with Wireless Backhaul

    DEFF Research Database (Denmark)

    Thomsen, Henning; De Carvalho, Elisabeth; Popovski, Petar

    2014-01-01

    of wireless emulated wire (WEW), based on two-way relaying and network coding. This setup leads to a new type of broadcast problem, with decoding conditions that are specific to the requirement for equivalence to the wired backhaul. We formulate and solve the associated optimization problems. The proposed...

  3. Astrophysics Decoding the cosmos

    CERN Document Server

    Irwin, Judith A

    2007-01-01

    Astrophysics: Decoding the Cosmos is an accessible introduction to the key principles and theories underlying astrophysics. This text takes a close look at the radiation and particles that we receive from astronomical objects, providing a thorough understanding of what this tells us, drawing the information together using examples to illustrate the process of astrophysics. Chapters dedicated to objects showing complex processes are written in an accessible manner and pull relevant background information together to put the subject firmly into context. The intention of the author is that the book will be a 'tool chest' for undergraduate astronomers wanting to know the how of astrophysics. Students will gain a thorough grasp of the key principles, ensuring that this often-difficult subject becomes more accessible.

  4. Neural Decoder for Topological Codes

    Science.gov (United States)

    Torlai, Giacomo; Melko, Roger G.

    2017-07-01

    We present an algorithm for error correction in topological codes that exploits modern machine learning techniques. Our decoder is constructed from a stochastic neural network called a Boltzmann machine, of the type extensively used in deep learning. We provide a general prescription for the training of the network and a decoding strategy that is applicable to a wide variety of stabilizer codes with very little specialization. We demonstrate the neural decoder numerically on the well-known two-dimensional toric code with phase-flip errors.

  5. Decoding bipedal locomotion from the rat sensorimotor cortex

    Science.gov (United States)

    Rigosa, J.; Panarese, A.; Dominici, N.; Friedli, L.; van den Brand, R.; Carpaneto, J.; DiGiovanna, J.; Courtine, G.; Micera, S.

    2015-10-01

    Objective. Decoding forelimb movements from the firing activity of cortical neurons has been interfaced with robotic and prosthetic systems to replace lost upper limb functions in humans. Despite the potential of this approach to improve locomotion and facilitate gait rehabilitation, decoding lower limb movement from the motor cortex has received comparatively little attention. Here, we performed experiments to identify the type and amount of information that can be decoded from neuronal ensemble activity in the hindlimb area of the rat motor cortex during bipedal locomotor tasks. Approach. Rats were trained to stand, step on a treadmill, walk overground and climb staircases in a bipedal posture. To impose this gait, the rats were secured in a robotic interface that provided support against the direction of gravity and in the mediolateral direction, but behaved transparently in the forward direction. After completion of training, rats were chronically implanted with a micro-wire array spanning the left hindlimb motor cortex to record single and multi-unit activity, and bipolar electrodes into 10 muscles of the right hindlimb to monitor electromyographic signals. Whole-body kinematics, muscle activity, and neural signals were simultaneously recorded during execution of the trained tasks over multiple days of testing. Hindlimb kinematics, muscle activity, gait phases, and locomotor tasks were decoded using offline classification algorithms. Main results. We found that the stance and swing phases of gait and the locomotor tasks were detected with accuracies as robust as 90% in all rats. Decoded hindlimb kinematics and muscle activity exhibited a larger variability across rats and tasks. Significance. Our study shows that the rodent motor cortex contains useful information for lower limb neuroprosthetic development. However, brain-machine interfaces estimating gait phases or locomotor behaviors, instead of continuous variables such as limb joint positions or speeds

  6. Implementation of a Tour Guide Robot System Using RFID Technology and Viterbi Algorithm-Based HMM for Speech Recognition

    Directory of Open Access Journals (Sweden)

    Neng-Sheng Pai

    2014-01-01

    Full Text Available This paper applied speech recognition and RFID technologies to develop an omni-directional mobile robot into a robot with voice control and guide introduction functions. For speech recognition, the speech signals were captured by short-time processing. The speaker first recorded the isolated words for the robot to create speech database of specific speakers. After the speech pre-processing of this speech database, the feature parameters of cepstrum and delta-cepstrum were obtained using linear predictive coefficient (LPC. Then, the Hidden Markov Model (HMM was used for model training of the speech database, and the Viterbi algorithm was used to find an optimal state sequence as the reference sample for speech recognition. The trained reference model was put into the industrial computer on the robot platform, and the user entered the isolated words to be tested. After processing by the same reference model and comparing with previous reference model, the path of the maximum total probability in various models found using the Viterbi algorithm in the recognition was the recognition result. Finally, the speech recognition and RFID systems were achieved in an actual environment to prove its feasibility and stability, and implemented into the omni-directional mobile robot.

  7. Continuous Force Decoding from Local Field Potentials of the Primary Motor Cortex in Freely Moving Rats.

    Science.gov (United States)

    Khorasani, Abed; Heydari Beni, Nargess; Shalchyan, Vahid; Daliri, Mohammad Reza

    2016-10-21

    Local field potential (LFP) signals recorded by intracortical microelectrodes implanted in primary motor cortex can be used as a high informative input for decoding of motor functions. Recent studies show that different kinematic parameters such as position and velocity can be inferred from multiple LFP signals as precisely as spiking activities, however, continuous decoding of the force magnitude from the LFP signals in freely moving animals has remained an open problem. Here, we trained three rats to press a force sensor for getting a drop of water as a reward. A 16-channel micro-wire array was implanted in the primary motor cortex of each trained rat, and obtained LFP signals were used for decoding of the continuous values recorded by the force sensor. Average coefficient of correlation and the coefficient of determination between decoded and actual force signals were r = 0.66 and R(2) = 0.42, respectively. We found that LFP signal on gamma frequency bands (30-120 Hz) had the most contribution in the trained decoding model. This study suggests the feasibility of using low number of LFP channels for the continuous force decoding in freely moving animals resembling BMI systems in real life applications.

  8. List Decoding of Algebraic Codes

    DEFF Research Database (Denmark)

    Nielsen, Johan Sebastian Rosenkilde

    We investigate three paradigms for polynomial-time decoding of Reed–Solomon codes beyond half the minimum distance: the Guruswami–Sudan algorithm, Power decoding and the Wu algorithm. The main results concern shaping the computational core of all three methods to a problem solvable by module...... minimisation; by applying the fastest known algorithms for this general problem, we then obtain realisations of each paradigm which are as fast or faster than all previously known methods. An element of this is the “2D key equation”, a heavily generalised form of the classical key equation, and we show how...... to solve such using module minimisation, or using our new Demand–Driven algorithm which is also based on module minimisation. The decoding paradigms are all derived and analysed in a self-contained manner, often in new ways or examined in greater depth than previously. Among a number of new results, we...

  9. LDPC Decoding on GPU for Mobile Device

    National Research Council Canada - National Science Library

    Yiqin Lu; Weiyue Su; Jiancheng Qin

    2016-01-01

    A flexible software LDPC decoder that exploits data parallelism for simultaneous multicode words decoding on the mobile device is proposed in this paper, supported by multithreading on OpenCL based...

  10. A Simple Decoder for Topological Codes

    Directory of Open Access Journals (Sweden)

    James Wootton

    2015-04-01

    Full Text Available Here we study an efficient algorithm for decoding topological codes. It is a simple form of HDRG decoder, which could be straightforwardly generalized to complex decoding problems. Specific results are obtained for the planar code with both i.i.d. and spatially correlated errors. The method is shown to compare well with existing ones, despite its simplicity.

  11. Error-erasure decoding of product codes.

    Science.gov (United States)

    Wainberg, S.

    1972-01-01

    Two error-erasure decoding algorithms for product codes that correct all the error-erasure patterns guaranteed correctable by the minimum Hamming distance of the product code are given. The first algorithm works when at least one of the component codes is majority-logic decodable. The second algorithm works for any product code. Both algorithms use the decoders of the component codes.

  12. Dynamics of intracellular information decoding.

    Science.gov (United States)

    Kobayashi, Tetsuya J; Kamimura, Atsushi

    2011-10-01

    A variety of cellular functions are robust even to substantial intrinsic and extrinsic noise in intracellular reactions and the environment that could be strong enough to impair or limit them. In particular, of substantial importance is cellular decision-making in which a cell chooses a fate or behavior on the basis of information conveyed in noisy external signals. For robust decoding, the crucial step is filtering out the noise inevitably added during information transmission. As a minimal and optimal implementation of such an information decoding process, the autocatalytic phosphorylation and autocatalytic dephosphorylation (aPadP) cycle was recently proposed. Here, we analyze the dynamical properties of the aPadP cycle in detail. We describe the dynamical roles of the stationary and short-term responses in determining the efficiency of information decoding and clarify the optimality of the threshold value of the stationary response and its information-theoretical meaning. Furthermore, we investigate the robustness of the aPadP cycle against the receptor inactivation time and intrinsic noise. Finally, we discuss the relationship among information decoding with information-dependent actions, bet-hedging and network modularity.

  13. Dynamics of intracellular information decoding

    Science.gov (United States)

    Kobayashi, Tetsuya J.; Kamimura, Atsushi

    2011-10-01

    A variety of cellular functions are robust even to substantial intrinsic and extrinsic noise in intracellular reactions and the environment that could be strong enough to impair or limit them. In particular, of substantial importance is cellular decision-making in which a cell chooses a fate or behavior on the basis of information conveyed in noisy external signals. For robust decoding, the crucial step is filtering out the noise inevitably added during information transmission. As a minimal and optimal implementation of such an information decoding process, the autocatalytic phosphorylation and autocatalytic dephosphorylation (aPadP) cycle was recently proposed. Here, we analyze the dynamical properties of the aPadP cycle in detail. We describe the dynamical roles of the stationary and short-term responses in determining the efficiency of information decoding and clarify the optimality of the threshold value of the stationary response and its information-theoretical meaning. Furthermore, we investigate the robustness of the aPadP cycle against the receptor inactivation time and intrinsic noise. Finally, we discuss the relationship among information decoding with information-dependent actions, bet-hedging and network modularity.

  14. Early Decoding and Encoding Strategies.

    Science.gov (United States)

    Goldwater-Rozensher, Susan; Hebard, Amy J.

    A combination of case study observation and mini-experimentation techniques were used to examine a number of issues of relevance in the study of the acquisition of beginning reading skills. Six children were divided equally among three instructional modes: phonics, whole word, and mixed. They were asked to decode and encode words, and their…

  15. Decoding intention at sensorimotor timescales.

    Directory of Open Access Journals (Sweden)

    Mathew Salvaris

    Full Text Available The ability to decode an individual's intentions in real time has long been a 'holy grail' of research on human volition. For example, a reliable method could be used to improve scientific study of voluntary action by allowing external probe stimuli to be delivered at different moments during development of intention and action. Several Brain Computer Interface applications have used motor imagery of repetitive actions to achieve this goal. These systems are relatively successful, but only if the intention is sustained over a period of several seconds; much longer than the timescales identified in psychophysiological studies for normal preparation for voluntary action. We have used a combination of sensorimotor rhythms and motor imagery training to decode intentions in a single-trial cued-response paradigm similar to those used in human and non-human primate motor control research. Decoding accuracy of over 0.83 was achieved with twelve participants. With this approach, we could decode intentions to move the left or right hand at sub-second timescales, both for instructed choices instructed by an external stimulus and for free choices generated intentionally by the participant. The implications for volition are considered.

  16. On Decoding Interleaved Chinese Remainder Codes

    DEFF Research Database (Denmark)

    Li, Wenhui; Sidorenko, Vladimir; Nielsen, Johan Sebastian Rosenkilde

    2013-01-01

    We model the decoding of Interleaved Chinese Remainder codes as that of finding a short vector in a Z-lattice. Using the LLL algorithm, we obtain an efficient decoding algorithm, correcting errors beyond the unique decoding bound and having nearly linear complexity. The algorithm can fail...... with a probability dependent on the number of errors, and we give an upper bound for this. Simulation results indicate that the bound is close to the truth. We apply the proposed decoding algorithm for decoding a single CR code using the idea of “Power” decoding, suggested for Reed-Solomon codes. A combination...... of these two methods can be used to decode low-rate Interleaved Chinese Remainder codes....

  17. Automatic wire twister.

    Science.gov (United States)

    Smith, J F; Rodeheaver, G T; Thacker, J G; Morgan, R F; Chang, D E; Fariss, B L; Edlich, R F

    1988-06-01

    This automatic wire twister used in surgery consists of a 6-inch needle holder attached to a twisting mechanism. The major advantage of this device is that it twists wires significantly more rapidly than the conventional manual techniques. Testing has found that the ultimate force required to disrupt the wires twisted by either the automatic wire twister or manual techniques did not differ significantly and was directly related to the number of twists. The automatic wire twister reduces the time needed for wire twisting without altering the security of the twisted wire.

  18. Stretched Wire Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Bowden, Gordon; /SLAC

    2005-09-06

    Stretched wires are beginning to play an important role in the alignment of accelerators and synchrotron light sources. Stretched wires are proposed for the alignment of the 130 meter long LCLS undulator. Wire position technology has reached sub-micron resolution yet analyses of perturbations to wire straightness are hard to find. This paper considers possible deviations of stretched wire from the simple 2-dimensional catenary form.

  19. LDPC Decoding on GPU for Mobile Device

    Directory of Open Access Journals (Sweden)

    Yiqin Lu

    2016-01-01

    Full Text Available A flexible software LDPC decoder that exploits data parallelism for simultaneous multicode words decoding on the mobile device is proposed in this paper, supported by multithreading on OpenCL based graphics processing units. By dividing the check matrix into several parts to make full use of both the local memory and private memory on GPU and properly modify the code capacity each time, our implementation on a mobile phone shows throughputs above 100 Mbps and delay is less than 1.6 millisecond in decoding, which make high-speed communication like video calling possible. To realize efficient software LDPC decoding on the mobile device, the LDPC decoding feature on communication baseband chip should be replaced to save the cost and make it easier to upgrade decoder to be compatible with a variety of channel access schemes.

  20. Soft-decision decoding of RS codes

    DEFF Research Database (Denmark)

    Justesen, Jørn

    2005-01-01

    By introducing a few simplifying assumptions we derive a simple condition for successful decoding using the Koetter-Vardy algorithm for soft-decision decoding of RS codes. We show that the algorithm has a significant advantage over hard decision decoding when the code rate is low, when two or more...... sets of received symbols have substantially different reliabilities, or when the number of alternative transmitted symbols is very small...

  1. Interior point decoding for linear vector channels

    Energy Technology Data Exchange (ETDEWEB)

    Wadayama, T [Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, Aichi, 466-8555 (Japan)], E-mail: wadayama@nitech.ac.jp

    2008-01-15

    In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter-symbol interference channels and partial response channels. It is shown that the maximum likelihood decoding (MLD) rule for a linear vector channel can be relaxed to a convex optimization problem, which is called a relaxed MLD problem.

  2. Toric Codes, Multiplicative Structure and Decoding

    DEFF Research Database (Denmark)

    Hansen, Johan Peder

    2017-01-01

    and aligns with decoding by error correcting pairs. We have used the multiplicative structure on toric codes to construct linear secret sharing schemes with \\emph{strong multiplication} via Massey's construction generalizing the Shamir Linear secret sharing shemes constructed from Reed-Solomon codes. We have...... constructed quantum error correcting codes from toric surfaces by the Calderbank-Shor-Steane method.......Long linear codes constructed from toric varieties over finite fields, their multiplicative structure and decoding. The main theme is the inherent multiplicative structure on toric codes. The multiplicative structure allows for \\emph{decoding}, resembling the decoding of Reed-Solomon codes...

  3. Application of Beyond Bound Decoding for High Speed Optical Communications

    DEFF Research Database (Denmark)

    Li, Bomin; Larsen, Knud J.; Vegas Olmos, Juan José

    2013-01-01

    This paper studies the application of beyond bound decoding method for high speed optical communications. This hard-decision decoding method outperforms traditional minimum distance decoding method, with a total net coding gain of 10.36 dB....

  4. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  5. Concatenated coding system with iterated sequential inner decoding

    DEFF Research Database (Denmark)

    Jensen, Ole Riis; Paaske, Erik

    1995-01-01

    We describe a concatenated coding system with iterated sequential inner decoding. The system uses convolutional codes of very long constraint length and operates on iterations between an inner Fano decoder and an outer Reed-Solomon decoder......We describe a concatenated coding system with iterated sequential inner decoding. The system uses convolutional codes of very long constraint length and operates on iterations between an inner Fano decoder and an outer Reed-Solomon decoder...

  6. Satellite demodulator and telecommand decoder

    Science.gov (United States)

    Pereiradelucena, Antonio Macilio

    1986-11-01

    This work presents the design, analysis and test results of the BPSK/NRZ-L demodulator and telecommand decoder of the data collecting the satellite of Missao Espacial Completa Brasileira (MECB). The constraints imposed by the space application motivate the adoption of nonconventional solutions. Basically, the innovations are the parallel subcarrier and bit synchronization and the replacement of multipliers by exclusive-or gates operating on digital signals. These innovations offer advantages in speed, power consumption and reliability. A partial and original mathematical analysis of the adopted solutions is presented.

  7. Laser Wire Stripper

    Science.gov (United States)

    1983-01-01

    NASA-developed space shuttle technology is used in a laser wire stripper designed by Raytheon Company. Laser beams cut through insulation on a wire without damaging conductive metal, because laser radiation that melts plastic insulation is reflected by the metal. The laser process is fast, clean, precise and repeatable. It eliminates quality control problems and the expense of rejected wiring.

  8. On minimizing the maximum broadcast decoding delay for instantly decodable network coding

    KAUST Repository

    Douik, Ahmed S.

    2014-09-01

    In this paper, we consider the problem of minimizing the maximum broadcast decoding delay experienced by all the receivers of generalized instantly decodable network coding (IDNC). Unlike the sum decoding delay, the maximum decoding delay as a definition of delay for IDNC allows a more equitable distribution of the delays between the different receivers and thus a better Quality of Service (QoS). In order to solve this problem, we first derive the expressions for the probability distributions of maximum decoding delay increments. Given these expressions, we formulate the problem as a maximum weight clique problem in the IDNC graph. Although this problem is known to be NP-hard, we design a greedy algorithm to perform effective packet selection. Through extensive simulations, we compare the sum decoding delay and the max decoding delay experienced when applying the policies to minimize the sum decoding delay and our policy to reduce the max decoding delay. Simulations results show that our policy gives a good agreement among all the delay aspects in all situations and outperforms the sum decoding delay policy to effectively minimize the sum decoding delay when the channel conditions become harsher. They also show that our definition of delay significantly improve the number of served receivers when they are subject to strict delay constraints.

  9. The Half-Duplex AWGN Single-Relay Channel: Full Decoding or Partial Decoding?

    CERN Document Server

    Ong, Lawrence; Kellett, Christopher M

    2011-01-01

    This paper compares the partial-decode-forward and the complete-decode-forward coding strategies for the half-duplex Gaussian single-relay channel. We analytically show that partial-decode-forward outperforms the more straightforward complete-decode-forward by at most 12.5%, for any channel parameters. Furthermore, in the following asymptotic cases, complete-decode-forward achieves the same rates as partial-decode-forward does: (i) when the relay is close to the source, (ii) when the relay is close to the destination, and (iii) when the SNR is low. In addition, when the SNR increases, the normalized gap between the rates achievable by the two coding strategies diminishes. Consequently, significant performance improvements are not achieved by optimizing the fraction of data the relay should decode and forward.

  10. Outlaw distributions and locally decodable codes

    NARCIS (Netherlands)

    J. Briët (Jop); Zeev Dvir; Sivakanth Gopi

    2016-01-01

    textabstractLocally decodable codes (LDCs) are error correcting codes that allow for decoding of a single message bit using a small number of queries to a corrupted encoding. Despite decades of study, the optimal trade-off between query complexity and codeword length is far from understood. In

  11. Decoding Algorithms for Random Linear Network Codes

    DEFF Research Database (Denmark)

    Heide, Janus; Pedersen, Morten Videbæk; Fitzek, Frank

    2011-01-01

    We consider the problem of efficient decoding of a random linear code over a finite field. In particular we are interested in the case where the code is random, relatively sparse, and use the binary finite field as an example. The goal is to decode the data using fewer operations to potentially a...

  12. A class of Sudan-decodable codes

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Refslund

    2000-01-01

    In this article, Sudan's algorithm is modified into an efficient method to list-decode a class of codes which can be seen as a generalization of Reed-Solomon codes. The algorithm is specialized into a very efficient method for unique decoding. The code construction can be generalized based...

  13. Oppositional Decoding as an Act of Resistance.

    Science.gov (United States)

    Steiner, Linda

    1988-01-01

    Argues that contributors to the "No Comment" feature of "Ms." magazine are engaging in oppositional decoding and speculates on why this is a satisfying group process. Also notes such decoding presents another challenge to the idea that mass media has the same effect on all audiences. (SD)

  14. Outlaw distributions and locally decodable codes

    NARCIS (Netherlands)

    J. Briët (Jop); Zeev Dvir; Sivakanth Gopi

    2017-01-01

    textabstractLocally decodable codes (LDCs) are error correcting codes that allow for decoding of a single message bit using a small number of queries to a corrupted encoding. Despite decades of study, the optimal trade-off between query complexity and codeword length is far from understood. In

  15. Outlaw distributions and locally decodable codes

    NARCIS (Netherlands)

    J. Briët (Jop); Z. Dvir (Zeev); S. Gopi (Sivakanth)

    2017-01-01

    htmlabstractLocally decodable codes (LDCs) are error correcting codes that allow for decoding of a single message bit using a small number of queries to a corrupted encoding. Despite decades of study, the optimal trade-off between query complexity and codeword length is far from understood. In this

  16. Following the Viterbi Path to Deduce Flagellar Actin-Interacting Proteins of Leishmania spp.: Report on Cofilins and Twinfilins

    Science.gov (United States)

    Pacheco, Ana Carolina L.; Araújo, Fabiana F.; Kamimura, Michel T.; Medeiros, Sarah R.; Viana, Daniel A.; Oliveira, Fátima de Cássia E.; Filho, Raimundo Araújo; Costa, Marcília P.; Oliveira, Diana M.

    2007-11-01

    For performing vital cellular processes, such as motility, eukaryotic cells rely on the actin cytoskeleton, whose structure and dynamics are tightly controlled by a large number of actin-interacting (AIP) or actin-related/regulating (ARP) proteins. Trypanosomatid protozoa, such as Leishmania, rely on their flagellum for motility and sensory reception, which are believed to allow parasite migration, adhesion, invasion and even persistence on mammalian host tissues to cause disease. Actin can determine cell stiffness and transmit force during mechanotransduction, cytokinesis, cell motility and other cellular shape changes, while the identification and analyses of AIPs can help to improve understanding of their mechanical properties on physiological architectures, such as the present case regarding Leishmania flagellar apparatus. This work conveniently apply bioinformatics tools in some refined pattern recognition techniques (such as hidden Markov models (HMMs) through the Viterbi algorithm/path) in order to improve the recognition of actin-binding/interacting activity through identification of AIPs in genomes, transcriptomes and proteomes of Leishmania species. We here report cofilin and twinfilin as putative components of the flagellar apparatus, a direct bioinformatics contribution in the secondary annotation of Leishmania and trypanosomatid genomes.

  17. Flicking-wire drag tensioner

    Science.gov (United States)

    Dassele, M. A.; Fairall, H.

    1978-01-01

    Wire-drag system improves wire profile and applies consistent drag to wire. Wire drag is continuously adjustable from zero drag to tensile strength of wire. No-sag wire drag is easier to thread than former system and requires minimal downtime for cleaning and maintenance.

  18. Design Space of Flexible Multigigabit LDPC Decoders

    Directory of Open Access Journals (Sweden)

    Philipp Schläfer

    2012-01-01

    Full Text Available Multigigabit LDPC decoders are demanded by standards like IEEE 802.15.3c and IEEE 802.11ad. To achieve the high throughput while supporting the needed flexibility, sophisticated architectures are mandatory. This paper comprehensively presents the design space for flexible multigigabit LDPC applications for the first time. The influence of various design parameters on the hardware is investigated in depth. Two new decoder architectures in a 65 nm CMOS technology are presented to further explore the design space. In the past, the memory domination was the bottleneck for throughputs of up to 1 Gbit/s. Our systematic investigation of column- versus row-based partially parallel decoders shows that this is no more a bottleneck for multigigabit architectures. The evolutionary progress in flexible multigigabit LDPC decoder design is highlighted in an extensive comparison of state-of-the-art decoders.

  19. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  20. Effect of wire shape on wire array discharge

    Energy Technology Data Exchange (ETDEWEB)

    Shimomura, N.; Tanaka, Y.; Yushita, Y.; Nagata, M. [University of Tokushima, Department of Electrical and Electronic Engineering, Tokushima (Japan); Teramoto, Y.; Katsuki, S.; Akiyama, H. [Kumamoto University, Department of Electrical and Computer Engineering, Kumamoto (Japan)

    2001-09-01

    Although considerable investigations have been reported on z-pinches to achieve nuclear fusion, little attention has been given from the point of view of how a wire array consisting of many parallel wires explodes. Instability existing in the wire array discharge has been shown. In this paper, the effect of wire shape in the wire array on unstable behavior of the wire array discharge is represented by numerical analysis. The claws on the wire formed in installation of wire may cause uniform current distribution on wire array. The effect of error of wire diameter in production is computed by Monte Carlo Method. (author)

  1. ARQ with sequential decoding of packetized data - Queueing analysis

    Science.gov (United States)

    Shacham, N.

    1984-10-01

    The operation of a sequential decoder in a packet-switching environment is considered. Packets arrive randomly at the decoder, and a packet is stored in a buffer if the decoder is busy upon its arrival. The decoder devotes no more than a time-out period of predetermined length to the decoding of any single packet. If packet decoding is completed within that period, the packet leaves the system. Otherwise, it is retransmitted and its decoding starts anew. While a packet is retransmitted, the decoder decodes another packet that resides in its buffer. An upper bound on the maximum rate of packets that can be supported by the channel-decoder combination is derived, and the optimum time-out that maximizes that rate is determined. A discrete-time model of the decoder's queue is presented, and the average queue length and throughput are evaluated.

  2. Iterative Decoding of Concatenated Codes: A Tutorial

    Directory of Open Access Journals (Sweden)

    Phillip A. Regalia

    2005-05-01

    Full Text Available The turbo decoding algorithm of a decade ago constituted a milestone in error-correction coding for digital communications, and has inspired extensions to generalized receiver topologies, including turbo equalization, turbo synchronization, and turbo CDMA, among others. Despite an accrued understanding of iterative decoding over the years, the “turbo principle” remains elusive to master analytically, thereby inciting interest from researchers outside the communications domain. In this spirit, we develop a tutorial presentation of iterative decoding for parallel and serial concatenated codes, in terms hopefully accessible to a broader audience. We motivate iterative decoding as a computationally tractable attempt to approach maximum-likelihood decoding, and characterize fixed points in terms of a “consensus” property between constituent decoders. We review how the decoding algorithm for both parallel and serial concatenated codes coincides with an alternating projection algorithm, which allows one to identify conditions under which the algorithm indeed converges to a maximum-likelihood solution, in terms of particular likelihood functions factoring into the product of their marginals. The presentation emphasizes a common framework applicable to both parallel and serial concatenated codes.

  3. Multiscale brain-machine interface decoders.

    Science.gov (United States)

    Han-Lin Hsieh; Shanechi, Maryam M

    2016-08-01

    Brain-machine interfaces (BMI) have vastly used a single scale of neural activity, e.g., spikes or electrocorticography (ECoG), as their control signal. New technology allows for simultaneous recording of multiple scales of neural activity, from spikes to local field potentials (LFP) and ECoG. These advances introduce the new challenge of modeling and decoding multiple scales of neural activity jointly. Such multi-scale decoding is challenging for two reasons. First, spikes are discrete-valued and ECoG/LFP are continuous-valued, resulting in fundamental differences in statistical characteristics. Second, the time-scales of these signals are different, with spikes having a millisecond time-scale and ECoG/LFP having much slower time-scales on the order of tens of milliseconds. Here we develop a new multiscale modeling and decoding framework that addresses these challenges. Our multiscale decoder extracts information from ECoG/LFP in addition to spikes, while operating at the fast time-scale of the spikes. The multiscale decoder specializes to a Kalman filter (KF) or to a point process filter (PPF) when no spikes or ECoG/LFP are available, respectively. Using closed-loop BMI simulations, we show that compared to PPF decoding of spikes alone or KF decoding of LFP/ECoG alone, the multiscale decoder significantly improves the accuracy and error performance of BMI control and runs at the fast millisecond time-scale of the spikes. This new multiscale modeling and decoding framework has the potential to improve BMI control using simultaneous multiscale neural activity.

  4. Decoding small surface codes with feedforward neural networks

    Science.gov (United States)

    Varsamopoulos, Savvas; Criger, Ben; Bertels, Koen

    2018-01-01

    Surface codes reach high error thresholds when decoded with known algorithms, but the decoding time will likely exceed the available time budget, especially for near-term implementations. To decrease the decoding time, we reduce the decoding problem to a classification problem that a feedforward neural network can solve. We investigate quantum error correction and fault tolerance at small code distances using neural network-based decoders, demonstrating that the neural network can generalize to inputs that were not provided during training and that they can reach similar or better decoding performance compared to previous algorithms. We conclude by discussing the time required by a feedforward neural network decoder in hardware.

  5. The serial message-passing schedule for LDPC decoding algorithms

    Science.gov (United States)

    Liu, Mingshan; Liu, Shanshan; Zhou, Yuan; Jiang, Xue

    2015-12-01

    The conventional message-passing schedule for LDPC decoding algorithms is the so-called flooding schedule. It has the disadvantage that the updated messages cannot be used until next iteration, thus reducing the convergence speed . In this case, the Layered Decoding algorithm (LBP) based on serial message-passing schedule is proposed. In this paper the decoding principle of LBP algorithm is briefly introduced, and then proposed its two improved algorithms, the grouped serial decoding algorithm (Grouped LBP) and the semi-serial decoding algorithm .They can improve LBP algorithm's decoding speed while maintaining a good decoding performance.

  6. Wire + Arc Additive Manufacturing

    OpenAIRE

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  7. Improved Power Decoding of One-Point Hermitian Codes

    DEFF Research Database (Denmark)

    Puchinger, Sven; Bouw, Irene; Rosenkilde, Johan Sebastian Heesemann

    2017-01-01

    We propose a new partial decoding algorithm for one-point Hermitian codes that can decode up to the same number of errors as the Guruswami–Sudan decoder. Simulations suggest that it has a similar failure probability as the latter one. The algorithm is based on a recent generalization of the power...... decoding algorithm for Reed–Solomon codes and does not require an expensive root-finding step. In addition, it promises improvements for decoding interleaved Hermitian codes....

  8. Charpak hemispherical wire chamber

    CERN Multimedia

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  9. Photovoltaic Wire Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

  10. Decoding of interleaved Reed-Solomon codes using improved power decoding

    DEFF Research Database (Denmark)

    Puchinger, Sven; Rosenkilde ne Nielsen, Johan

    2017-01-01

    We propose a new partial decoding algorithm for m-interleaved Reed-Solomon (IRS) codes that can decode, with high probability, a random error of relative weight 1 − Rm/m+1 at all code rates R, in time polynomial in the code length n. For m > 2, this is an asymptotic improvement over the previous...... state-of-the-art for all rates, and the first improvement for R > 1/3 in the last 20 years. The method combines collaborative decoding of IRS codes with power decoding up to the Johnson radius....

  11. Low-Power Bitstream-Residual Decoder for H.264/AVC Baseline Profile Decoding

    Directory of Open Access Journals (Sweden)

    Xu Ke

    2009-01-01

    Full Text Available Abstract We present the design and VLSI implementation of a novel low-power bitstream-residual decoder for H.264/AVC baseline profile. It comprises a syntax parser, a parameter decoder, and an Inverse Quantization Inverse Transform (IQIT decoder. The syntax parser detects and decodes each incoming codeword in the bitstream under the control of a hierarchical Finite State Machine (FSM; the IQIT decoder performs inverse transform and quantization with pipelining and parallelism. Various power reduction techniques, such as data-driven based on statistic results, nonuniform partition, precomputation, guarded evaluation, hierarchical FSM decomposition, TAG method, zero-block skipping, and clock gating , are adopted and integrated throughout the bitstream-residual decoder. With innovative architecture, the proposed design is able to decode QCIF video sequences of 30 fps at a clock rate as low as 1.5 MHz. A prototype H.264/AVC baseline decoding chip utilizing the proposed decoder is fabricated in UMC 0.18  m 1P6M CMOS technology. The proposed design is measured under 1 V 1.8 V supply with 0.1 V step. It dissipates 76  W at 1 V and 253  W at 1.8 V.

  12. Improved compression of network coding vectors using erasure decoding and list decoding

    CERN Document Server

    Li, Shizheng

    2010-01-01

    Practical random network coding based schemes for multicast include a header in each packet that records the transformation between the sources and the terminal. The header introduces an overhead that can be significant in certain scenarios. In previous work, parity check matrices of error control codes along with error decoding were used to reduce this overhead. In this work we propose novel packet formats that allow us to use erasure decoding and list decoding. Both schemes have a smaller overhead compared to the error decoding based scheme, when the number of sources combined in a packet is not too small.

  13. Orientation decoding depends on maps, not columns

    Science.gov (United States)

    Freeman, Jeremy; Brouwer, Gijs Joost; Heeger, David J.; Merriam, Elisha P.

    2011-01-01

    The representation of orientation in primary visual cortex (V1) has been examined at a fine spatial scale corresponding to the columnar architecture. We present functional magnetic resonance imaging (fMRI) measurements providing evidence for a topographic map of orientation preference in human V1 at a much coarser scale, in register with the angular-position component of the retinotopic map of V1. This coarse-scale orientation map provides a parsimonious explanation for why multivariate pattern analysis methods succeed in decoding stimulus orientation from fMRI measurements, challenging the widely-held assumption that decoding results reflect sampling of spatial irregularities in the fine-scale columnar architecture. Decoding stimulus attributes and cognitive states from fMRI measurements has proven useful for a number of applications, but our results demonstrate that the interpretation cannot assume decoding reflects or exploits columnar organization. PMID:21451017

  14. 1998 wire development workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development.

  15. Transport in quantum wires

    Indian Academy of Sciences (India)

    This motivated us to study the LL model of a quantum wire, with Fermi liquid leads and the unusual feature of ... of quantized conductance even in clean quantum wires and a novel odd–even effect in the presence of a .... But in one dimension, it is well-known that the FL theory breaks down, and the ground state is a ...

  16. Commercial and Industrial Wiring.

    Science.gov (United States)

    Kaltwasser, Stan; Flowers, Gary

    This module is the third in a series of three wiring publications, includes additional technical knowledge and applications required for job entry in the commercial and industrial wiring trade. The module contains 15 instructional units that cover the following topics: blueprint reading and load calculations; tools and equipment; service;…

  17. Coder and decoder of fractal signals of comb-type structure

    Directory of Open Access Journals (Sweden)

    Politanskyi R. L.

    2014-08-01

    Full Text Available The article presents a coder and decoder of fractal signals of comb-type structure (FSCS based on microcontrollers (MC. The coder and decoder consist of identical control modules, while their managed modules have different schematic constructions. The control module performs forming or recognition of signals, and also carries out the function of information exchange with a computer. The basic element of the control module is a PIC18F2550 microcontroller from MicroChip. The coder of the system forms fractal signals of a given order according to the information bits coming from the computer. Samples of the calculated values of the amplitudes of elementary rectangular pulses that constitute the structure of fractal pulses are stored in the memory of the microcontroller as a table. Minimum bit capacity of the DAC necessary for the generation of FSCS of fourth order is four bits. The operation algorithm, "wired" into the controller of the program, provides for encoding of the transmitted information by two-bit symbols. Recognition of the start of transmission of each byte in communication channel is performed by the transmission of the timing signal. In a decoder the microcontroller carries out reception and decoding of the received fractal signals which are then transmitted to the computer. The developed algorithm of the program for the microcontroller of the decoder is carried out by determination of order of fractal impulse after the value of sum of amplitudes of elementary impulses, constituents fractal signal. The programs for coder and decoder are written in "C". In the most critical places of the program influencing on the fast-acting of chart “assembler” insertions are done. The blocks of the coder and decoder were connected with a coaxial 10 meters long cable with an impendance of 75 Ohm. The signals generated by the developed coder of FSCS, were studied using a digital oscillograph. On the basis of the obtained spectrums, it is possible

  18. Digital Communications: Detectors and Estimators for the Time-Varying Channel with Intersymbol Interference.

    Science.gov (United States)

    STATISTICAL PROCESSES, MAXIMUM LIKELIHOOD ESTIMATION, *INTERSYMBOL INTERFERENCE, TIME VARYING SYSTEMS, VITERBI DECODING, COMPUTERIZED SIMULATION, DATA TRANSMISSION SYSTEMS , *DIGITAL COMMUNICATION SYSTEMS

  19. Performance breakdown in optimal stimulus decoding.

    Science.gov (United States)

    Lubomir Kostal; Lansky, Petr; Pilarski, Stevan

    2015-06-01

    One of the primary goals of neuroscience is to understand how neurons encode and process information about their environment. The problem is often approached indirectly by examining the degree to which the neuronal response reflects the stimulus feature of interest. In this context, the methods of signal estimation and detection theory provide the theoretical limits on the decoding accuracy with which the stimulus can be identified. The Cramér-Rao lower bound on the decoding precision is widely used, since it can be evaluated easily once the mathematical model of the stimulus-response relationship is determined. However, little is known about the behavior of different decoding schemes with respect to the bound if the neuronal population size is limited. We show that under broad conditions the optimal decoding displays a threshold-like shift in performance in dependence on the population size. The onset of the threshold determines a critical range where a small increment in size, signal-to-noise ratio or observation time yields a dramatic gain in the decoding precision. We demonstrate the existence of such threshold regions in early auditory and olfactory information coding. We discuss the origin of the threshold effect and its impact on the design of effective coding approaches in terms of relevant population size.

  20. FPGA implementation of low complexity LDPC iterative decoder

    Science.gov (United States)

    Verma, Shivani; Sharma, Sanjay

    2016-07-01

    Low-density parity-check (LDPC) codes, proposed by Gallager, emerged as a class of codes which can yield very good performance on the additive white Gaussian noise channel as well as on the binary symmetric channel. LDPC codes have gained lots of importance due to their capacity achieving property and excellent performance in the noisy channel. Belief propagation (BP) algorithm and its approximations, most notably min-sum, are popular iterative decoding algorithms used for LDPC and turbo codes. The trade-off between the hardware complexity and the decoding throughput is a critical factor in the implementation of the practical decoder. This article presents introduction to LDPC codes and its various decoding algorithms followed by realisation of LDPC decoder by using simplified message passing algorithm and partially parallel decoder architecture. Simplified message passing algorithm has been proposed for trade-off between low decoding complexity and decoder performance. It greatly reduces the routing and check node complexity of the decoder. Partially parallel decoder architecture possesses high speed and reduced complexity. The improved design of the decoder possesses a maximum symbol throughput of 92.95 Mbps and a maximum of 18 decoding iterations. The article presents implementation of 9216 bits, rate-1/2, (3, 6) LDPC decoder on Xilinx XC3D3400A device from Spartan-3A DSP family.

  1. Completion time reduction in instantly decodable network coding through decoding delay control

    KAUST Repository

    Douik, Ahmed S.

    2014-12-01

    For several years, the completion time and the decoding delay problems in Instantly Decodable Network Coding (IDNC) were considered separately and were thought to completely act against each other. Recently, some works aimed to balance the effects of these two important IDNC metrics but none of them studied a further optimization of one by controlling the other. In this paper, we study the effect of controlling the decoding delay to reduce the completion time below its currently best known solution. We first derive the decoding-delay-dependent expressions of the users\\' and their overall completion times. Although using such expressions to find the optimal overall completion time is NP-hard, we use a heuristic that minimizes the probability of increasing the maximum of these decoding-delay-dependent completion time expressions after each transmission through a layered control of their decoding delays. Simulation results show that this new algorithm achieves both a lower mean completion time and mean decoding delay compared to the best known heuristic for completion time reduction. The gap in performance becomes significant for harsh erasure scenarios.

  2. Decoding the content of delayed intentions.

    Science.gov (United States)

    Gilbert, Sam J

    2011-02-23

    Rostrolateral prefrontal cortex (RLPFC) plays a key role in our ability to postpone the execution of intended behaviors until after another activity has been performed. However, it is poorly understood in computational terms. One crucial question is whether RLPFC represents the content of delayed intentions or plays a nonspecific role. In this human functional magnetic resonance imaging study (n = 32), RLPFC was active while participants stored delayed intentions during a distracting ongoing task. Multivariate analysis showed that the intended cue for future action and the intended behavior could be decoded from distinct posterior brain regions. However, the content of intentions could not be decoded from RLPFC itself. Functional connectivity analysis showed that RLPFC increased its coupling with content-representing regions during intention storage. Furthermore, trials with relatively high RLPFC activity were associated with enhanced decoding. Thus, RLPFC may enable realization of delayed intentions via interactions with posterior brain regions, which represent their content.

  3. Ultrathin Nanocrystalline Magnetic Wires

    Directory of Open Access Journals (Sweden)

    Horia Chiriac

    2017-02-01

    Full Text Available The magnetic characteristics of FINEMET type glass-coated nanowires and submicron wires are investigated by taking into account the structural evolution induced by specific annealing all the way from a fully amorphous state to a nanocrystalline structure. The differences between the magnetic properties of these ultrathin wires and those of the thicker glass-coated microwires and “conventional” wires with similar structures have been emphasized and explained phenomenologically. The domain wall propagation in these novel nanowires and submicron wires, featuring a combination between an amorphous and a crystalline structure, has also been studied, given the recent interest in the preparation and investigation of new materials suitable for the development of domain wall logic applications.

  4. Dual wire weld feed proportioner

    Science.gov (United States)

    Nugent, R. E.

    1968-01-01

    Dual feed mechanism enables proportioning of two different weld feed wires during automated TIG welding to produce a weld alloy deposit of the desired composition. The wires are fed into the weld simultaneously. The relative feed rates of the wires and the wire diameters determine the weld deposit composition.

  5. Neuroprosthetic Decoder Training as Imitation Learning.

    Directory of Open Access Journals (Sweden)

    Josh Merel

    2016-05-01

    Full Text Available Neuroprosthetic brain-computer interfaces function via an algorithm which decodes neural activity of the user into movements of an end effector, such as a cursor or robotic arm. In practice, the decoder is often learned by updating its parameters while the user performs a task. When the user's intention is not directly observable, recent methods have demonstrated value in training the decoder against a surrogate for the user's intended movement. Here we show that training a decoder in this way is a novel variant of an imitation learning problem, where an oracle or expert is employed for supervised training in lieu of direct observations, which are not available. Specifically, we describe how a generic imitation learning meta-algorithm, dataset aggregation (DAgger, can be adapted to train a generic brain-computer interface. By deriving existing learning algorithms for brain-computer interfaces in this framework, we provide a novel analysis of regret (an important metric of learning efficacy for brain-computer interfaces. This analysis allows us to characterize the space of algorithmic variants and bounds on their regret rates. Existing approaches for decoder learning have been performed in the cursor control setting, but the available design principles for these decoders are such that it has been impossible to scale them to naturalistic settings. Leveraging our findings, we then offer an algorithm that combines imitation learning with optimal control, which should allow for training of arbitrary effectors for which optimal control can generate goal-oriented control. We demonstrate this novel and general BCI algorithm with simulated neuroprosthetic control of a 26 degree-of-freedom model of an arm, a sophisticated and realistic end effector.

  6. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  7. High resolution decoding techniques and single-chip decoders for multi-anode microchannel arrays

    Science.gov (United States)

    Kasle, David B.

    1989-01-01

    While the pixel size in a standard multianode microchannel array (MAMA) photon-counting detector is determined by the spacing of the anode array, the factor most fundamentally limiting pixel resolution is the spacing of the channels in the microchannel plate. Detector resolution can be improved by means of digitization followed by a centroiding procedure. The decoding hardware and the techniques for enhanced pixel resolution are presently discussed with a view to the factors of speed and complexity. A single-chip CMOS gate-array implementation of the decoder is devised and compared with existing multichip decoders' performance.

  8. Decoding algorithm for vortex communications receiver

    Science.gov (United States)

    Kupferman, Judy; Arnon, Shlomi

    2018-01-01

    Vortex light beams can provide a tremendous alphabet for encoding information. We derive a symbol decoding algorithm for a direct detection matrix detector vortex beam receiver using Laguerre Gauss (LG) modes, and develop a mathematical model of symbol error rate (SER) for this receiver. We compare SER as a function of signal to noise ratio (SNR) for our algorithm and for the Pearson correlation algorithm. To our knowledge, this is the first comprehensive treatment of a decoding algorithm of a matrix detector for an LG receiver.

  9. Decoding Interleaved Gabidulin Codes using Alekhnovich's Algorithm

    DEFF Research Database (Denmark)

    Puchinger, Sven; Müelich, Sven; Mödinger, David

    2017-01-01

    We prove that Alekhnovich's algorithm can be used for row reduction of skew polynomial matrices. This yields an O(ℓ3n(ω+1)/2log⁡(n)) decoding algorithm for ℓ-Interleaved Gabidulin codes of length n, where ω is the matrix multiplication exponent.......We prove that Alekhnovich's algorithm can be used for row reduction of skew polynomial matrices. This yields an O(ℓ3n(ω+1)/2log⁡(n)) decoding algorithm for ℓ-Interleaved Gabidulin codes of length n, where ω is the matrix multiplication exponent....

  10. Decoding LDPC Convolutional Codes on Markov Channels

    Directory of Open Access Journals (Sweden)

    Kashyap Manohar

    2008-01-01

    Full Text Available Abstract This paper describes a pipelined iterative technique for joint decoding and channel state estimation of LDPC convolutional codes over Markov channels. Example designs are presented for the Gilbert-Elliott discrete channel model. We also compare the performance and complexity of our algorithm against joint decoding and state estimation of conventional LDPC block codes. Complexity analysis reveals that our pipelined algorithm reduces the number of operations per time step compared to LDPC block codes, at the expense of increased memory and latency. This tradeoff is favorable for low-power applications.

  11. Decoding LDPC Convolutional Codes on Markov Channels

    Directory of Open Access Journals (Sweden)

    Chris Winstead

    2008-04-01

    Full Text Available This paper describes a pipelined iterative technique for joint decoding and channel state estimation of LDPC convolutional codes over Markov channels. Example designs are presented for the Gilbert-Elliott discrete channel model. We also compare the performance and complexity of our algorithm against joint decoding and state estimation of conventional LDPC block codes. Complexity analysis reveals that our pipelined algorithm reduces the number of operations per time step compared to LDPC block codes, at the expense of increased memory and latency. This tradeoff is favorable for low-power applications.

  12. Decoding Hermitian Codes with Sudan's Algorithm

    DEFF Research Database (Denmark)

    Høholdt, Tom; Nielsen, Rasmus Refslund

    1999-01-01

    We present an efficient implementation of Sudan's algorithm for list decoding Hermitian codes beyond half the minimum distance. The main ingredients are an explicit method to calculate so-called increasing zero bases, an efficient interpolation algorithm for finding the Q-polynomial, and a reduct......We present an efficient implementation of Sudan's algorithm for list decoding Hermitian codes beyond half the minimum distance. The main ingredients are an explicit method to calculate so-called increasing zero bases, an efficient interpolation algorithm for finding the Q...

  13. Generalized Sudan's List Decoding for Order Domain Codes

    DEFF Research Database (Denmark)

    Geil, Hans Olav; Matsumoto, Ryutaroh

    2007-01-01

    We generalize Sudan's list decoding algorithm without multiplicity to evaluation codes coming from arbitrary order domains. The number of correctable errors by the proposed method is larger than the original list decoding without multiplicity.......We generalize Sudan's list decoding algorithm without multiplicity to evaluation codes coming from arbitrary order domains. The number of correctable errors by the proposed method is larger than the original list decoding without multiplicity....

  14. Decoding of concatenated codes with interleaved outer codes

    DEFF Research Database (Denmark)

    Justesen, Jørn; Høholdt, Tom; Thommesen, Christian

    2004-01-01

    Recently Bleichenbacher et al. proposed a decoding algorithm for interleaved (N, K) Reed-Solomon codes, which allows close to N-K errors to be corrected in many cases. We discuss the application of this decoding algorithm to concatenated codes.......Recently Bleichenbacher et al. proposed a decoding algorithm for interleaved (N, K) Reed-Solomon codes, which allows close to N-K errors to be corrected in many cases. We discuss the application of this decoding algorithm to concatenated codes....

  15. Decoding of concatenated codes with interleaved outer codes

    DEFF Research Database (Denmark)

    Justesen, Jørn; Thommesen, Christian; Høholdt, Tom

    2004-01-01

    Recently Bleichenbacher et al. proposed a decoding algorithm for interleaved Reed/Solomon codes, which allows close to errors to be corrected in many cases. We discuss the application of this decoding algorithm to concatenated codes. (NK) N-K......Recently Bleichenbacher et al. proposed a decoding algorithm for interleaved Reed/Solomon codes, which allows close to errors to be corrected in many cases. We discuss the application of this decoding algorithm to concatenated codes. (NK) N-K...

  16. Improved digital TV encoding and decoding system

    Science.gov (United States)

    Deutermann, A. R.

    1967-01-01

    Analog-to-digital coder and digital-to-analog decoder system handles wideband TV signals. The system incorporates solid state plug-in modular units and is operated in a VSD /Variable Slope Delta Modulation/ mode or in the conventional one-bit DM /Delta Modulation/ mode.

  17. Older Adults Have Difficulty in Decoding Sarcasm

    Science.gov (United States)

    Phillips, Louise H.; Allen, Roy; Bull, Rebecca; Hering, Alexandra; Kliegel, Matthias; Channon, Shelley

    2015-01-01

    Younger and older adults differ in performance on a range of social-cognitive skills, with older adults having difficulties in decoding nonverbal cues to emotion and intentions. Such skills are likely to be important when deciding whether someone is being sarcastic. In the current study we investigated in a life span sample whether there are…

  18. Chinese Character Decoding: A Semantic Bias?

    Science.gov (United States)

    Williams, Clay; Bever, Thomas

    2010-01-01

    The effects of semantic and phonetic radicals on Chinese character decoding were examined. Our results suggest that semantic and phonetic radicals are each available for access when a corresponding task emphasizes one or the other kind of radical. But in a more neutral lexical recognition task, the semantic radical is more informative. Semantic…

  19. Turbo decoder core design for system development

    Science.gov (United States)

    Chen, Xiaoyi; Yao, Qingdong; Liu, Peng

    2003-04-01

    Due to their near Shannon-capacity performance, turbo codes have received a considerable amount of attention since their introduction. They are particularly attractive for cellular communication systems and have been included in the specifications for both the WCDMA(UMTS) and cdma2000 third-generation cellular standards. The log-MAP decoding algorithm and some technologies used to reduce the complexity have discussed in the past days. But we can see that if we apply the Turbo code to wireless communications,the decoding process rate is the bottleneck. The software implement is not realistic in today"s DSP process rate. So the hardware design is supposed to realize the decoding. The purpose of this paper is to present a full ASIC design way of Turbo decoding. Many technologies are added to the basic Log-MAP algorithm to simple the design and improve the performance. With the log-MAP algorithm, the Jacobi logarithm is computed exactly using max*()=ln(exp(x)+exp(y))=max()+fc(|y-x|),The correction function fc(|y-x|) is important because there will be 0.5dB SNR loss without it. The linear approximation can be used and the linear parameters was selected carefully to suit hardware realize in our design. In order to save the power consumption and also to assure the performance, the quantization is important in ASIC design, we adopt a compromise scheme to save the power and also there is good BER behaves. Many noisy frames can be corrected with a few iterations while some of the more noisy frames need to experience a full number of iterations (NOI). Thus, if the decoder could stop the iteration as soon as the frame becomes correct, the average NOI would be reduced. There are many ways to stop the iteration such as CRC, compare and so on, we adopt a significantly less computation and much less storage stop criteria. For long frames the memory for storing the entire frame of the forward probability α or the backward probability β can be very large. Available products all

  20. Bounded-Angle Iterative Decoding of LDPC Codes

    Science.gov (United States)

    Dolinar, Samuel; Andrews, Kenneth; Pollara, Fabrizio; Divsalar, Dariush

    2009-01-01

    Bounded-angle iterative decoding is a modified version of conventional iterative decoding, conceived as a means of reducing undetected-error rates for short low-density parity-check (LDPC) codes. For a given code, bounded-angle iterative decoding can be implemented by means of a simple modification of the decoder algorithm, without redesigning the code. Bounded-angle iterative decoding is based on a representation of received words and code words as vectors in an n-dimensional Euclidean space (where n is an integer).

  1. A Scalable Architecture of a Structured LDPC Decoder

    Science.gov (United States)

    Lee, Jason Kwok-San; Lee, Benjamin; Thorpe, Jeremy; Andrews, Kenneth; Dolinar, Sam; Hamkins, Jon

    2004-01-01

    We present a scalable decoding architecture for a certain class of structured LDPC codes. The codes are designed using a small (n,r) protograph that is replicated Z times to produce a decoding graph for a (Z x n, Z x r) code. Using this architecture, we have implemented a decoder for a (4096,2048) LDPC code on a Xilinx Virtex-II 2000 FPGA, and achieved decoding speeds of 31 Mbps with 10 fixed iterations. The implemented message-passing algorithm uses an optimized 3-bit non-uniform quantizer that operates with 0.2dB implementation loss relative to a floating point decoder.

  2. Unsupervised adaptation of brain machine interface decoders

    Directory of Open Access Journals (Sweden)

    Tayfun eGürel

    2012-11-01

    Full Text Available The performance of neural decoders can degrade over time due to nonstationarities in the relationship between neuronal activity and behavior. In this case, brain-machine interfaces (BMI require adaptation of their decoders to maintain high performance across time. One way to achieve this is by use of periodical calibration phases, during which the BMI system (or an external human demonstrator instructs the user to perform certain movements or behaviors. This approach has two disadvantages: (i calibration phases interrupt the autonomous operation of the BMI and (ii between two calibration phases the BMI performance might not be stable but continuously decrease. A better alternative would be that the BMI decoder is able to continuously adapt in an unsupervised manner during autonomous BMI operation, i.e. without knowing the movement intentions of the user. In the present article, we present an efficient method for such unsupervised training of BMI systems for continuous movement control. The proposed method utilizes a cost function derived from neuronal recordings, which guides a learning algorithm to evaluate the decoding parameters. We verify the performance of our adaptive method by simulating a BMI user with an optimal feedback control model and its interaction with our adaptive BMI decoder. The simulation results show that the cost function and the algorithm yield fast and precise trajectories towards targets at random orientations on a 2-dimensional computer screen. For initially unknown and nonstationary tuning parameters, our unsupervised method is still able to generate precise trajectories and to keep its performance stable in the long term. The algorithm can optionally work also with neuronal error signals instead or in conjunction with the proposed unsupervised adaptation.

  3. Wire core reactor for NTP

    Science.gov (United States)

    Harty, R. B.

    1991-01-01

    The development of the wire core system for Nuclear Thermal Propulsion (NTP) that took place from 1963 to 1965 is discussed. A wire core consists of a fuel wire with spacer wires. It's an annular flow core having a central control rod. There are actually four of these, with beryllium solid reflectors on both ends and all the way around. Much of the information on the concept is given in viewgraph form. Viewgraphs are presented on design details of the wire core, the engine design, engine weight vs. thrust, a technique used to fabricate the wire fuel element, and axial temperature distribution.

  4. Belief propagation decoding of quantum channels by passing quantum messages

    Science.gov (United States)

    Renes, Joseph M.

    2017-07-01

    The belief propagation (BP) algorithm is a powerful tool in a wide range of disciplines from statistical physics to machine learning to computational biology, and is ubiquitous in decoding classical error-correcting codes. The algorithm works by passing messages between nodes of the factor graph associated with the code and enables efficient decoding of the channel, in some cases even up to the Shannon capacity. Here we construct the first BP algorithm which passes quantum messages on the factor graph and is capable of decoding the classical-quantum channel with pure state outputs. This gives explicit decoding circuits whose number of gates is quadratic in the code length. We also show that this decoder can be modified to work with polar codes for the pure state channel and as part of a decoder for transmitting quantum information over the amplitude damping channel. These represent the first explicit capacity-achieving decoders for non-Pauli channels.

  5. Modern wiring practice

    CERN Document Server

    Steward, W E

    2012-01-01

    Continuously in print since 1952, Modern Wiring Practice has now been fully revised to provide an up-to-date source of reference to building services design and installation in the 21st century. This compact and practical guide addresses wiring systems design and electrical installation together in one volume, creating a comprehensive overview of the whole process for contractors and architects, as well as electricians and other installation engineers. Best practice is incorporated throughout, combining theory and practice with clear and accessible explanation, all

  6. Wiring and lighting

    CERN Document Server

    Kitcher, Chris

    2013-01-01

    Wiring and Lighting provides a comprehensive guide to DIY wiring around the home. It sets out the regulations and legal requirements surrounding electrical installation work, giving clear guidelines that will enable the reader to understand what electrical work they are able to carry out, and what the testing and certification requirements are once the work is completed. Topics covered include: Different types of circuits; Types of cables and cable installation under floors and through joists; Isolating, earthing and bonding; Accessory boxes and fixings; Voltage bands; Detailed advice on safe

  7. Electric wiring domestic

    CERN Document Server

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  8. Percutaneous Kirschner wire (K-wire) fixation for humerus shaft ...

    African Journals Online (AJOL)

    In the present study, Kirschner wires (K-wire) were used to achieve a closed intramedullary fixation of humeral shaft fractures. The objective of this study was to evaluate the efficacy of intramedullary K-wires for the treatment of humeral shaft fracture in children. Patients and Methods: This prospective study was conducted in ...

  9. Wiring for space applications program

    Science.gov (United States)

    Hammoud, Ahmad

    1994-01-01

    The insulation testing and analysis consists of: identifying and prioritizing NASA wiring requirements; selecting candidate wiring constructions; developing test matrix and formulating test program; managing, coordinating, and conducting tests; and analyzing and documenting data, establishing guidelines and recommendations.

  10. Debate: Wired versus Wireless.

    Science.gov (United States)

    Meeks, Glenn; Nair, Prakash

    2000-01-01

    Debates the issue of investing in wiring schools for desktop computer networks versus using laptops and wireless networks. Included are cost considerations and the value of technology for learning. Suggestions include using wireless networks for existing schools, hardwiring computers for new construction, and not using computers for elementary…

  11. Wired vs. Wireless.

    Science.gov (United States)

    Fielding, Randall

    2000-01-01

    Presents a debate on which technology will be in tomorrow's classrooms and the pros and cons of wiring classrooms and using a wireless network. Concluding comments address the likelihood, and desirability, of placing computers throughout the entire educational process and what types of computers and capabilities are needed. (GR)

  12. Wired to freedom

    DEFF Research Database (Denmark)

    Jepsen, Kim Sune Karrasch; Bertilsson, Margareta

    2017-01-01

    dimension of life science through a notion of public politics adopted from the political theory of John Dewey. We show how cochlear implantation engages different social imaginaries on the collective and individual levels and we suggest that users share an imaginary of being “wired to freedom” that involves...

  13. Gaseous wire detectors

    Energy Technology Data Exchange (ETDEWEB)

    Va' vra, J.

    1997-08-01

    This article represents a series of three lectures describing topics needed to understand the design of typical gaseous wire detectors used in large high energy physics experiments; including the electrostatic design, drift of electrons in the electric and magnetic field, the avalanche, signal creation, limits on the position accuracy as well as some problems one encounters in practical operations.

  14. 3D Wire 2015

    DEFF Research Database (Denmark)

    Jordi, Moréton; F, Escribano; J. L., Farias

    This document is a general report on the implementation of gamification in 3D Wire 2015 event. As the second gamification experience in this event, we have delved deeply in the previous objectives (attracting public areas less frequented exhibition in previous years and enhance networking) and have...

  15. Practical wiring in SI units

    CERN Document Server

    Miller, Henry A

    2013-01-01

    Practical Wiring, Volume 1 is a 13-chapter book that first describes some of the common hand tools used in connection with sheathed wiring. Subsequent chapters discuss the safety in wiring, cables, conductor terminations, insulating sheathed wiring, conductor sizes, and consumer's control equipments. Other chapters center on socket outlets, plugs, lighting subcircuits, lighting accessories, bells, and primary and secondary cells. This book will be very valuable to students involved in this field of interest.

  16. Wire EDM for Refractory Materials

    Science.gov (United States)

    Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

    1982-01-01

    In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

  17. On Lattice Sequential Decoding for The Unconstrained AWGN Channel

    KAUST Repository

    Abediseid, Walid

    2012-10-01

    In this paper, the performance limits and the computational complexity of the lattice sequential decoder are analyzed for the unconstrained additive white Gaussian noise channel. The performance analysis available in the literature for such a channel has been studied only under the use of the minimum Euclidean distance decoder that is commonly referred to as the lattice decoder. Lattice decoders based on solutions to the NP-hard closest vector problem are very complex to implement, and the search for low complexity receivers for the detection of lattice codes is considered a challenging problem. However, the low computational complexity advantage that sequential decoding promises, makes it an alternative solution to the lattice decoder. In this work, we characterize the performance and complexity tradeoff via the error exponent and the decoding complexity, respectively, of such a decoder as a function of the decoding parameter --- the bias term. For the above channel, we derive the cut-off volume-to-noise ratio that is required to achieve a good error performance with low decoding complexity.

  18. On Lattice Sequential Decoding for The Unconstrained AWGN Channel

    KAUST Repository

    Abediseid, Walid

    2013-04-04

    In this paper, the performance limits and the computational complexity of the lattice sequential decoder are analyzed for the unconstrained additive white Gaussian noise channel. The performance analysis available in the literature for such a channel has been studied only under the use of the minimum Euclidean distance decoder that is commonly referred to as the \\\\textit{lattice decoder}. Lattice decoders based on solutions to the NP-hard closest vector problem are very complex to implement, and the search for low complexity receivers for the detection of lattice codes is considered a challenging problem. However, the low computational complexity advantage that sequential decoding promises, makes it an alternative solution to the lattice decoder. In this work, we characterize the performance and complexity tradeoff via the error exponent and the decoding complexity, respectively, of such a decoder as a function of the decoding parameter --- the bias term. For the above channel, we derive the cut-off volume-to-noise ratio that is required to achieve a good error performance with low decoding complexity.

  19. Video coding for decoding power-constrained embedded devices

    Science.gov (United States)

    Lu, Ligang; Sheinin, Vadim

    2004-01-01

    Low power dissipation and fast processing time are crucial requirements for embedded multimedia devices. This paper presents a technique in video coding to decrease the power consumption at a standard video decoder. Coupled with a small dedicated video internal memory cache on a decoder, the technique can substantially decrease the amount of data traffic to the external memory at the decoder. A decrease in data traffic to the external memory at decoder will result in multiple benefits: faster real-time processing and power savings. The encoder, given prior knowledge of the decoder"s dedicated video internal memory cache management scheme, regulates its choice of motion compensated predictors to reduce the decoder"s external memory accesses. This technique can be used in any standard or proprietary encoder scheme to generate a compliant output bit stream decodable by standard CPU-based and dedicated hardware-based decoders for power savings with the best quality-power cost trade off. Our simulation results show that with a relatively small amount of dedicated video internal memory cache, the technique may decrease the traffic between CPU and external memory over 50%.

  20. Hardware Implementation of Serially Concatenated PPM Decoder

    Science.gov (United States)

    Moision, Bruce; Hamkins, Jon; Barsoum, Maged; Cheng, Michael; Nakashima, Michael

    2009-01-01

    A prototype decoder for a serially concatenated pulse position modulation (SCPPM) code has been implemented in a field-programmable gate array (FPGA). At the time of this reporting, this is the first known hardware SCPPM decoder. The SCPPM coding scheme, conceived for free-space optical communications with both deep-space and terrestrial applications in mind, is an improvement of several dB over the conventional Reed-Solomon PPM scheme. The design of the FPGA SCPPM decoder is based on a turbo decoding algorithm that requires relatively low computational complexity while delivering error-rate performance within approximately 1 dB of channel capacity. The SCPPM encoder consists of an outer convolutional encoder, an interleaver, an accumulator, and an inner modulation encoder (more precisely, a mapping of bits to PPM symbols). Each code is describable by a trellis (a finite directed graph). The SCPPM decoder consists of an inner soft-in-soft-out (SISO) module, a de-interleaver, an outer SISO module, and an interleaver connected in a loop (see figure). Each SISO module applies the Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm to compute a-posteriori bit log-likelihood ratios (LLRs) from apriori LLRs by traversing the code trellis in forward and backward directions. The SISO modules iteratively refine the LLRs by passing the estimates between one another much like the working of a turbine engine. Extrinsic information (the difference between the a-posteriori and a-priori LLRs) is exchanged rather than the a-posteriori LLRs to minimize undesired feedback. All computations are performed in the logarithmic domain, wherein multiplications are translated into additions, thereby reducing complexity and sensitivity to fixed-point implementation roundoff errors. To lower the required memory for storing channel likelihood data and the amounts of data transfer between the decoder and the receiver, one can discard the majority of channel likelihoods, using only the remainder in

  1. Decoding Local Field Potentials for Neural Interfaces.

    Science.gov (United States)

    Jackson, Andrew; Hall, Thomas M

    2017-10-01

    The stability and frequency content of local field potentials (LFPs) offer key advantages for long-term, low-power neural interfaces. However, interpreting LFPs may require new signal processing techniques which should be informed by a scientific understanding of how these recordings arise from the coordinated activity of underlying neuronal populations. We review current approaches to decoding LFPs for brain-machine interface (BMI) applications, and suggest several directions for future research. To facilitate an improved understanding of the relationship between LFPs and spike activity, we share a dataset of multielectrode recordings from monkey motor cortex, and describe two unsupervised analysis methods we have explored for extracting a low-dimensional feature space that is amenable to biomimetic decoding and biofeedback training.

  2. Sequential decoders for large MIMO systems

    KAUST Repository

    Ali, Konpal S.

    2014-05-01

    Due to their ability to provide high data rates, multiple-input multiple-output (MIMO) systems have become increasingly popular. Decoding of these systems with acceptable error performance is computationally very demanding. In this paper, we employ the Sequential Decoder using the Fano Algorithm for large MIMO systems. A parameter called the bias is varied to attain different performance-complexity trade-offs. Low values of the bias result in excellent performance but at the expense of high complexity and vice versa for higher bias values. Numerical results are done that show moderate bias values result in a decent performance-complexity trade-off. We also attempt to bound the error by bounding the bias, using the minimum distance of a lattice. The variations in complexity with SNR have an interesting trend that shows room for considerable improvement. Our work is compared against linear decoders (LDs) aided with Element-based Lattice Reduction (ELR) and Complex Lenstra-Lenstra-Lovasz (CLLL) reduction. © 2014 IFIP.

  3. Decoding Delay Controlled Completion Time Reduction in Instantly Decodable Network Coding

    KAUST Repository

    Douik, Ahmed

    2016-06-27

    For several years, the completion time and the decoding delay problems in Instantly Decodable Network Coding (IDNC) were considered separately and were thought to act completely against each other. Recently, some works aimed to balance the effects of these two important IDNC metrics but none of them studied a further optimization of one by controlling the other. This paper investigates the effect of controlling the decoding delay to reduce the completion time below its currently best-known solution in both perfect and imperfect feedback with persistent erasure channels. To solve the problem, the decodingdelay- dependent expressions of the users’ and overall completion times are derived in the complete feedback scenario. Although using such expressions to find the optimal overall completion time is NP-hard, the paper proposes two novel heuristics that minimizes the probability of increasing the maximum of these decoding-delay-dependent completion time expressions after each transmission through a layered control of their decoding delays. Afterward, the paper extends the study to the imperfect feedback scenario in which uncertainties at the sender affects its ability to anticipate accurately the decoding delay increase at each user. The paper formulates the problem in such environment and derives the expression of the minimum increase in the completion time. Simulation results show the performance of the proposed solutions and suggest that both heuristics achieves a lower mean completion time as compared to the best-known heuristics for the completion time reduction in perfect and imperfect feedback. The gap in performance becomes more significant as the erasure of the channel increases.

  4. Design of a VLSI Decoder for Partially Structured LDPC Codes

    Directory of Open Access Journals (Sweden)

    Fabrizio Vacca

    2008-01-01

    of their parity matrix can be partitioned into two disjoint sets, namely, the structured and the random ones. For the proposed class of codes a constructive design method is provided. To assess the value of this method the constructed codes performance are presented. From these results, a novel decoding method called split decoding is introduced. Finally, to prove the effectiveness of the proposed approach a whole VLSI decoder is designed and characterized.

  5. Obelix Wire Chamber

    CERN Multimedia

    1986-01-01

    Two wire chambers made originally for the R807 Experiment at CERN's Intersecting Storage Rings. In 1986 they were used for the PS 201 experiment (Obelix Experiment) at LEAR, the Low Energy Antiproton Ring. The group of researchers from Turin, using the chambers at that time, changed the acquisition system using for the first time 8 bit (10 bit non linear) analog to digital conversion for incoming signals from the chambers. The acquisition system was controlled by 54 CPU and 80 digital signal processors. The power required for all the electronics was 40 kW. For the period, this system was one of the most powerful on-line apparatus in the world. The Obelix Experiment was closed in 1996. To find more about how a wire chamber works, see the description for object CERN-OBJ-DE-038.

  6. Command Wire Sensor Measurements

    Science.gov (United States)

    2012-09-01

    NPS anechoic chamber is located in Spanagel Hall, Room 604. Although the chamber was built for instruction purposes only, it can be used for research...thesis is to investigate the wire scattering behavior and clutter characteristics through measurements performed in the NPS anechoic chamber. The...research has successfully resolved the various multipath components within the anechoic chamber. The transmit-receive coupling between the antennas was

  7. Sub-quadratic decoding of one-point hermitian codes

    DEFF Research Database (Denmark)

    Nielsen, Johan Sebastian Rosenkilde; Beelen, Peter

    2015-01-01

    We present the first two sub-quadratic complexity decoding algorithms for one-point Hermitian codes. The first is based on a fast realization of the Guruswami-Sudan algorithm using state-of-the-art algorithms from computer algebra for polynomial-ring matrix minimization. The second is a power...... decoding algorithm: an extension of classical key equation decoding which gives a probabilistic decoding algorithm up to the Sudan radius. We show how the resulting key equations can be solved by the matrix minimization algorithms from computer algebra, yielding similar asymptotic complexities....

  8. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  9. Adaptive Single-Trial Error/Erasure Decoding of Reed-Solomon Codes

    CERN Document Server

    Senger, Christian; Schober, Steffen; Bossert, Martin; Zyablov, Victor V

    2011-01-01

    Algebraic decoding algorithms are commonly applied for the decoding of Reed-Solomon codes. Their main advantages are low computational complexity and predictable decoding capabilities. Many algorithms can be extended for correction of both errors and erasures. This enables the decoder to exploit binary quantized reliability information obtained from the transmission channel: Received symbols with high reliability are forwarded to the decoding algorithm while symbols with low reliability are erased. In this paper we investigate adaptive single-trial error/erasure decoding of Reed-Solomon codes, i.e. we derive an adaptive erasing strategy which minimizes the residual codeword error probability after decoding. Our result is applicable to any error/erasure decoding algorithm as long as its decoding capabilities can be expressed by a decoder capability function. Examples are Bounded Minimum Distance decoding with the Berlekamp-Massey- or the Sugiyama algorithms and the Guruswami-Sudan list decoder.

  10. On Rational Interpolation-Based List-Decoding and List-Decoding Binary Goppa Codes

    DEFF Research Database (Denmark)

    Beelen, Peter; Høholdt, Tom; Nielsen, Johan Sebastian Rosenkilde

    2013-01-01

    We derive the Wu list-decoding algorithm for generalized Reed–Solomon (GRS) codes by using Gröbner bases over modules and the Euclidean algorithm as the initial algorithm instead of the Berlekamp–Massey algorithm. We present a novel method for constructing the interpolation polynomial fast. We give...

  11. Bitstream decoding processor for fast entropy decoding of variable length coding-based multiformat videos

    Science.gov (United States)

    Jo, Hyunho; Sim, Donggyu

    2014-06-01

    We present a bitstream decoding processor for entropy decoding of variable length coding-based multiformat videos. Since most of the computational complexity of entropy decoders comes from bitstream accesses and table look-up process, the developed bitstream processing unit (BsPU) has several designated instructions to access bitstreams and to minimize branch operations in the table look-up process. In addition, the instruction for bitstream access has the capability to remove emulation prevention bytes (EPBs) of H.264/AVC without initial delay, repeated memory accesses, and additional buffer. Experimental results show that the proposed method for EPB removal achieves a speed-up of 1.23 times compared to the conventional EPB removal method. In addition, the BsPU achieves speed-ups of 5.6 and 3.5 times in entropy decoding of H.264/AVC and MPEG-4 Visual bitstreams, respectively, compared to an existing processor without designated instructions and a new table mapping algorithm. The BsPU is implemented on a Xilinx Virtex5 LX330 field-programmable gate array. The MPEG-4 Visual (ASP, Level 5) and H.264/AVC (Main Profile, Level 4) are processed using the developed BsPU with a core clock speed of under 250 MHz in real time.

  12. Metering Wheel-Wire Track Wire Boom Deployment Mechanism

    Science.gov (United States)

    Granoff, Mark S.

    2014-01-01

    The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

  13. Reduction in wire tension caused by wire clamping and wire tensioner removal: an experimental Ilizarov frame study.

    Science.gov (United States)

    La Russa, Valentina; Skallerud, Bjørn; Klaksvik, Jomar; Foss, Olav A

    2011-03-01

    The stability of an external ring fixator mainly depends on wire tension. Wire fixators should maintain the tension during both wire clamping to the ring and removal of the tensioner device. In the present study the loss in wire tension related to fixator clamping and wire tensioner removal using three different wire fixator designs was studied. The fixators were based on two different cannulated bolts and a washer. Effects from two different pretension levels in combination with three different bolt torque levels upon loss in wire tension were described. Emitted wire vibration frequency was used to assess the corresponding wire tension. Wire tension was determined after each wire fixator tightening and after the removal of the wire tensioner. Increased bolt torque led to a small decrease in tension for both pretension levels. A considerable higher tension loss was measured when removing the wire tensioner. In all cases, the combination of a new cannulated bolt and a washer maintained the highest tension.

  14. Errors and erasures decoding for interference channels

    Science.gov (United States)

    Stuber, G.; Mark, J.; Blake, I.

    This paper examines the gains to be realized by using an errors-and-erasures decoding strategy on a pulse jammed channel, rather than errors-only, for concatenated Reed-Solomon/orthogonal codes. The work is largely computational and serves to quantify the gains achievable in such a situation. Previous studies have shown that the gains of errors-and-erasures over errors-only on the AWGN channel are minimal. The gains reported here for the pulse jammed channel are more substantial, particularly for the lower duty cycles.

  15. Memory-efficient decoding of LDPC codes

    Science.gov (United States)

    Kwok-San Lee, Jason; Thorpe, Jeremy; Hawkins, Jon

    2005-01-01

    We present a low-complexity quantization scheme for the implementation of regular (3,6) LDPC codes. The quantization parameters are optimized to maximize the mutual information between the source and the quantized messages. Using this non-uniform quantized belief propagation algorithm, we have simulated that an optimized 3-bit quantizer operates with 0.2dB implementation loss relative to a floating point decoder, and an optimized 4-bit quantizer operates less than 0.1dB quantization loss.

  16. Instantly Decodable Network Coding: From Centralized to Device-to-Device Communications

    KAUST Repository

    Douik, Ahmed S.

    2015-05-01

    From its introduction to its quindecennial, network coding have built a strong reputation in enhancing packet recovery process and achieving maximum information flow in both wires and wireless networks. Traditional studies focused on optimizing the throughput of the network by proposing complex schemes that achieve optimal delay. With the shift toward distributed computing at mobile devices, throughput and complexity become both critical factors that affect the efficiency of a coding scheme. Instantly decodable network coding imposed itself as a new paradigm in network coding that trades off this two aspects. This paper presents a survey of instantly decodable network coding schemes that are proposed in the literature. The various schemes are identified, categorized and evaluated. Two categories can be distinguished namely the conventional centralized schemes and the distributed or cooperative schemes. For each scheme, the comparison is carried out in terms of reliability, performance, complexity and packet selection methodology. Although the performance is generally inversely proportional to the computation complexity, numerous successful schemes from both the performance and complexity viewpoint are identified.

  17. Review of wire chamber aging

    Energy Technology Data Exchange (ETDEWEB)

    Va' Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs.

  18. Wiring regulations in brief

    CERN Document Server

    Tricker, Ray

    2012-01-01

    Tired of trawling through the Wiring Regs?Perplexed by Part P?Confused by cables, conductors and circuits?Then look no further! This handy guide provides an on-the-job reference source for Electricians, Designers, Service Engineers, Inspectors, Builders, Students, DIY enthusiastsTopic-based chapters link areas of working practice - such as cables, installations, testing and inspection, special locations - with the specifics of the Regulations themselves. This allows quick and easy identification of the official requirements relating to the situati

  19. Role of gender and linguistic diversity in word decoding development

    NARCIS (Netherlands)

    Verhoeven, L.T.W.; Leeuwe, J.F.J. van

    2011-01-01

    The purpose of the present study was to investigate the role of gender and linguistic diversity in the growth of Dutch word decoding skills throughout elementary school for a representative sample of children living in the Netherlands. Following a longitudinal design, the children's decoding

  20. Does Linguistic Comprehension Support the Decoding Skills of Struggling Readers?

    Science.gov (United States)

    Blick, Michele; Nicholson, Tom; Chapman, James; Berman, Jeanette

    2017-01-01

    This study investigated the contribution of linguistic comprehension to the decoding skills of struggling readers. Participants were 36 children aged between eight and 12 years, all below average in decoding but differing in linguistic comprehension. The children read passages from the Neale Analysis of Reading Ability and their first 25 miscues…

  1. EXIT Chart Analysis of Binary Message-Passing Decoders

    DEFF Research Database (Denmark)

    Lechner, Gottfried; Pedersen, Troels; Kramer, Gerhard

    2007-01-01

    Binary message-passing decoders for LDPC codes are analyzed using EXIT charts. For the analysis, the variable node decoder performs all computations in the L-value domain. For the special case of a hard decision channel, this leads to the well know Gallager B algorithm, while the analysis can...

  2. LDPC Codes--Structural Analysis and Decoding Techniques

    Science.gov (United States)

    Zhang, Xiaojie

    2012-01-01

    Low-density parity-check (LDPC) codes have been the focus of much research over the past decade thanks to their near Shannon limit performance and to their efficient message-passing (MP) decoding algorithms. However, the error floor phenomenon observed in MP decoding, which manifests itself as an abrupt change in the slope of the error-rate curve,…

  3. Decoding Information in the Human Hippocampus: A User's Guide

    Science.gov (United States)

    Chadwick, Martin J.; Bonnici, Heidi M.; Maguire, Eleanor A.

    2012-01-01

    Multi-voxel pattern analysis (MVPA), or "decoding", of fMRI activity has gained popularity in the neuroimaging community in recent years. MVPA differs from standard fMRI analyses by focusing on whether information relating to specific stimuli is encoded in patterns of activity across multiple voxels. If a stimulus can be predicted, or decoded,…

  4. Multilingual Speakers' Problems in Decoding in a Second Language.

    Science.gov (United States)

    Kaldor, Susan; Shell, Ruth

    Through an experiment investigating the processes used by several speakers of Asian languages to decode passages by speakers of Australian English, this paper seeks to establish and categorize the types of problems encountered by multilingual speakers when decoding the speech of monolingual speakers in one of their (the multilinguals') second…

  5. EEG source imaging assists decoding in a face recognition task

    DEFF Research Database (Denmark)

    Andersen, Rasmus S.; Eliasen, Anders U.; Pedersen, Nicolai

    2017-01-01

    and rather strong a priori information must be invoked. Recent work by Edelman et al. (2016) has demonstrated that introduction of a spatially focal source space representation can improve decoding of motor imagery. In this work we explore the generality of Edelman et al. hypothesis by considering decoding...

  6. Regular expressions for decoding of neural network outputs.

    Science.gov (United States)

    Strauß, Tobias; Leifert, Gundram; Grüning, Tobias; Labahn, Roger

    2016-07-01

    This article proposes a convenient tool for decoding the output of neural networks trained by Connectionist Temporal Classification (CTC) for handwritten text recognition. We use regular expressions to describe the complex structures expected in the writing. The corresponding finite automata are employed to build a decoder. We analyze theoretically which calculations are relevant and which can be avoided. A great speed-up results from an approximation. We conclude that the approximation most likely fails if the regular expression does not match the ground truth which is not harmful for many applications since the low probability will be even underestimated. The proposed decoder is very efficient compared to other decoding methods. The variety of applications reaches from information retrieval to full text recognition. We refer to applications where we integrated the proposed decoder successfully. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Frame-rate performance modeling of software MPEG decoder

    Science.gov (United States)

    Ramamoorthy, Victor

    1997-01-01

    A software MPEG decoder, though attractive in terms of performance and cost, opens up new technical challenges. The most critical question is: When does a software decoder drop a frame? How to predict its timing performance well ahead of its implementation? It is not easy to answer these questions without introducing a stochastic model of the decoding time. With a double buffering scheme, fluctuations in decoding time can be smoothed out to a large extent. However, dropping of frames can not be totally eliminated. New ideas of slip and asymptotic synchronous locking are shown to answer critical design questions of a software decoder. Beneath the troubled world of frame droppings lies the beauty and harmony of our stochastic formulation.

  8. FPGA Prototyping of RNN Decoder for Convolutional Codes

    Directory of Open Access Journals (Sweden)

    Salcic Zoran

    2006-01-01

    Full Text Available This paper presents prototyping of a recurrent type neural network (RNN convolutional decoder using system-level design specification and design flow that enables easy mapping to the target FPGA architecture. Implementation and the performance measurement results have shown that an RNN decoder for hard-decision decoding coupled with a simple hard-limiting neuron activation function results in a very low complexity, which easily fits into standard Altera FPGA. Moreover, the design methodology allowed modeling of complete testbed for prototyping RNN decoders in simulation and real-time environment (same FPGA, thus enabling evaluation of BER performance characteristics of the decoder for various conditions of communication channel in real time.

  9. Iterative List Decoding of Concatenated Source-Channel Codes

    Science.gov (United States)

    Hedayat, Ahmadreza; Nosratinia, Aria

    2005-12-01

    Whenever variable-length entropy codes are used in the presence of a noisy channel, any channel errors will propagate and cause significant harm. Despite using channel codes, some residual errors always remain, whose effect will get magnified by error propagation. Mitigating this undesirable effect is of great practical interest. One approach is to use the residual redundancy of variable length codes for joint source-channel decoding. In this paper, we improve the performance of residual redundancy source-channel decoding via an iterative list decoder made possible by a nonbinary outer CRC code. We show that the list decoding of VLC's is beneficial for entropy codes that contain redundancy. Such codes are used in state-of-the-art video coders, for example. The proposed list decoder improves the overall performance significantly in AWGN and fully interleaved Rayleigh fading channels.

  10. Iterative List Decoding of Concatenated Source-Channel Codes

    Directory of Open Access Journals (Sweden)

    Hedayat Ahmadreza

    2005-01-01

    Full Text Available Whenever variable-length entropy codes are used in the presence of a noisy channel, any channel errors will propagate and cause significant harm. Despite using channel codes, some residual errors always remain, whose effect will get magnified by error propagation. Mitigating this undesirable effect is of great practical interest. One approach is to use the residual redundancy of variable length codes for joint source-channel decoding. In this paper, we improve the performance of residual redundancy source-channel decoding via an iterative list decoder made possible by a nonbinary outer CRC code. We show that the list decoding of VLC's is beneficial for entropy codes that contain redundancy. Such codes are used in state-of-the-art video coders, for example. The proposed list decoder improves the overall performance significantly in AWGN and fully interleaved Rayleigh fading channels.

  11. Corrosion of Wires on Wooden Wire-Bound Packaging Crates

    Science.gov (United States)

    Samuel L. Zelinka; Stan Lebow

    2015-01-01

    Wire-bound packaging crates are used by the US Army to transport materials. Because these crates may be exposed to harsh environments, they are dip-treated with a wood preservative (biocide treatment). For many years, zinc-naphthenate was the most commonly used preservative for these packaging crates and few corrosion problems with the wires were observed. Recently,...

  12. Lattice Sequential Decoder for Coded MIMO Channel: Performance and Complexity Analysis

    CERN Document Server

    Abediseid, Walid

    2011-01-01

    In this paper, the performance limit of lattice sequential decoder for lattice space-time coded MIMO channel is analysed. We determine the rates achievable by lattice coding and sequential decoding applied to such channel. The diversity-multiplexing tradeoff (DMT) under lattice sequential decoding is derived as a function of its parameter---the bias term. The bias parameter is critical for controlling the amount of computations required at the decoding stage. Achieving low decoding complexity requires increasing the value of the bias term. However, this is done at the expense of losing the optimal tradeoff of the channel. We show how such a decoder can bridge the gap between lattice decoder and low complexity decoders. Moreover, the computational complexity of lattice sequential decoder is analysed. Specifically, we derive the tail distribution of the decoder's computational complexity in the high signal-to-noise ratio regime. Similar to the conventional sequential decoder used in discrete memoryless channel,...

  13. Most Wired 2006: measuring value.

    Science.gov (United States)

    Solovy, Alden

    2006-07-01

    As the Most Wired hospitals incorporate information technology into their strategic plans, they combine a"balanced scorecard"approach with classic business analytics to measure how well IT delivers on their goals. To find out which organizations made this year's 100 Most Wired list, as well as those named in other survey categories, go to the foldout section.

  14. Secure information display by use of multiple decoding masks

    Science.gov (United States)

    Yamamoto, Hirotsugu; Hayasaki, Yoshio; Nishida, Nobuo

    2004-10-01

    Security has become an important issue as information technology has become increasingly pervasive in our everyday lives. Security risks arise with a display that shows decrypted information. In this paper, we propose a secure information display technique by use of visual cryptography. Its decryption requires no special computing devices and is implemented using only human vision. To improve security of the key to decode the encrypted displayed image, multiple decoding masks have been constructed based on visual secret sharing scheme. The proposed display appears as a random pattern to anyone who looks at it unless the person views the displayed image through stacked multiple decoding masks. We have constructed code sets to share the secret image information with a displayed image and multiple decoding masks. The decoding process is a kind of optical processing based on spatial encoding and it needs no computer calculation, which means that no decrypted data exists in a computer system. Thus, the proposed display technique is secure against theft of the decrypted data and eavesdropping of the display signals, and provides a limited viewing zone. Multiple decoding masks increase security of the decoding masks.

  15. On Decoding Grid Cell Population Codes Using Approximate Belief Propagation.

    Science.gov (United States)

    Yoo, Yongseok; Kim, Woori

    2017-03-01

    Neural systems are inherently noisy. One well-studied example of a noise reduction mechanism in the brain is the population code, where representing a variable with multiple neurons allows the encoded variable to be recovered with fewer errors. Studies have assumed ideal observer models for decoding population codes, and the manner in which information in the neural population can be retrieved remains elusive. This letter addresses a mechanism by which realistic neural circuits can recover encoded variables. Specifically, the decoding problem of recovering a spatial location from populations of grid cells is studied using belief propagation. We extend the belief propagation decoding algorithm in two aspects. First, beliefs are approximated rather than being calculated exactly. Second, decoding noises are introduced into the decoding circuits. Numerical simulations demonstrate that beliefs can be effectively approximated by combining polynomial nonlinearities with divisive normalization. This approximate belief propagation algorithm is tolerant to decoding noises. Thus, this letter presents a realistic model for decoding neural population codes and investigates fault-tolerant information retrieval mechanisms in the brain.

  16. O2-GIDNC: Beyond instantly decodable network coding

    KAUST Repository

    Aboutorab, Neda

    2013-06-01

    In this paper, we are concerned with extending the graph representation of generalized instantly decodable network coding (GIDNC) to a more general opportunistic network coding (ONC) scenario, referred to as order-2 GIDNC (O2-GIDNC). In the O2-GIDNC scheme, receivers can store non-instantly decodable packets (NIDPs) comprising two of their missing packets, and use them in a systematic way for later decodings. Once this graph representation is found, it can be used to extend the GIDNC graph-based analyses to the proposed O2-GIDNC scheme with a limited increase in complexity. In the proposed O2-GIDNC scheme, the information of the stored NIDPs at the receivers and the decoding opportunities they create can be exploited to improve the broadcast completion time and decoding delay compared to traditional GIDNC scheme. The completion time and decoding delay minimizing algorithms that can operate on the new O2-GIDNC graph are further described. The simulation results show that our proposed O2-GIDNC improves the completion time and decoding delay performance of the traditional GIDNC. © 2013 IEEE.

  17. Encoder-decoder optimization for brain-computer interfaces.

    Directory of Open Access Journals (Sweden)

    Josh Merel

    2015-06-01

    Full Text Available Neuroprosthetic brain-computer interfaces are systems that decode neural activity into useful control signals for effectors, such as a cursor on a computer screen. It has long been recognized that both the user and decoding system can adapt to increase the accuracy of the end effector. Co-adaptation is the process whereby a user learns to control the system in conjunction with the decoder adapting to learn the user's neural patterns. We provide a mathematical framework for co-adaptation and relate co-adaptation to the joint optimization of the user's control scheme ("encoding model" and the decoding algorithm's parameters. When the assumptions of that framework are respected, co-adaptation cannot yield better performance than that obtainable by an optimal initial choice of fixed decoder, coupled with optimal user learning. For a specific case, we provide numerical methods to obtain such an optimized decoder. We demonstrate our approach in a model brain-computer interface system using an online prosthesis simulator, a simple human-in-the-loop pyschophysics setup which provides a non-invasive simulation of the BCI setting. These experiments support two claims: that users can learn encoders matched to fixed, optimal decoders and that, once learned, our approach yields expected performance advantages.

  18. Glycan microarrays for decoding the glycome

    Science.gov (United States)

    Rillahan, Cory D.; Paulson, James C.

    2011-01-01

    In the last decade glycan microarrays have revolutionized the analysis of the specificity of glycan binding proteins, providing information that simultaneously illuminates the biology mediated by them and decodes the information content of the glycome. Numerous methods have emerged for arraying glycans in a ‘chip’ format, and glycan libraries have been assembled that address the diversity of the human glycome. Such arrays have been successfully used for analysis of glycan binding proteins that mediate mammalian biology, host-pathogen interactions, immune recognition of glycans relevant to vaccine production and cancer antigens. This review covers the development of glycan microarrays and applications that have provided insights into the roles of mammalian and microbial glycan binding proteins. PMID:21469953

  19. Decoding the mechanisms of Antikythera astronomical device

    CERN Document Server

    Lin, Jian-Liang

    2016-01-01

    This book presents a systematic design methodology for decoding the interior structure of the Antikythera mechanism, an astronomical device from ancient Greece. The historical background, surviving evidence and reconstructions of the mechanism are introduced, and the historical development of astronomical achievements and various astronomical instruments are investigated. Pursuing an approach based on the conceptual design of modern mechanisms and bearing in mind the standards of science and technology at the time, all feasible designs of the six lost/incomplete/unclear subsystems are synthesized as illustrated examples, and 48 feasible designs of the complete interior structure are presented. This approach provides not only a logical tool for applying modern mechanical engineering knowledge to the reconstruction of the Antikythera mechanism, but also an innovative research direction for identifying the original structures of the mechanism in the future. In short, the book offers valuable new insights for all...

  20. Decoding speech for understanding and treating aphasia.

    Science.gov (United States)

    Pasley, Brian N; Knight, Robert T

    2013-01-01

    Aphasia is an acquired language disorder with a diverse set of symptoms that can affect virtually any linguistic modality across both the comprehension and production of spoken language. Partial recovery of language function after injury is common but typically incomplete. Rehabilitation strategies focus on behavioral training to induce plasticity in underlying neural circuits to maximize linguistic recovery. Understanding the different neural circuits underlying diverse language functions is a key to developing more effective treatment strategies. This chapter discusses a systems identification analytic approach to the study of linguistic neural representation. The focus of this framework is a quantitative, model-based characterization of speech and language neural representations that can be used to decode, or predict, speech representations from measured brain activity. Recent results of this approach are discussed in the context of applications to understanding the neural basis of aphasia symptoms and the potential to optimize plasticity during the rehabilitation process. © 2013 Elsevier B.V. All rights reserved.

  1. Academic Training - Bioinformatics: Decoding the Genome

    CERN Multimedia

    Chris Jones

    2006-01-01

    ACADEMIC TRAINING LECTURE SERIES 27, 28 February 1, 2, 3 March 2006 from 11:00 to 12:00 - Auditorium, bldg. 500 Decoding the Genome A special series of 5 lectures on: Recent extraordinary advances in the life sciences arising through new detection technologies and bioinformatics The past five years have seen an extraordinary change in the information and tools available in the life sciences. The sequencing of the human genome, the discovery that we possess far fewer genes than foreseen, the measurement of the tiny changes in the genomes that differentiate us, the sequencing of the genomes of many pathogens that lead to diseases such as malaria are all examples of completely new information that is now available in the quest for improved healthcare. New tools have allowed similar strides in the discovery of the associated protein structures, providing invaluable information for those searching for new drugs. New DNA microarray chips permit simultaneous measurement of the state of expression of tens...

  2. Encoding and Decoding Models in Cognitive Electrophysiology

    Directory of Open Access Journals (Sweden)

    Christopher R. Holdgraf

    2017-09-01

    Full Text Available Cognitive neuroscience has seen rapid growth in the size and complexity of data recorded from the human brain as well as in the computational tools available to analyze this data. This data explosion has resulted in an increased use of multivariate, model-based methods for asking neuroscience questions, allowing scientists to investigate multiple hypotheses with a single dataset, to use complex, time-varying stimuli, and to study the human brain under more naturalistic conditions. These tools come in the form of “Encoding” models, in which stimulus features are used to model brain activity, and “Decoding” models, in which neural features are used to generated a stimulus output. Here we review the current state of encoding and decoding models in cognitive electrophysiology and provide a practical guide toward conducting experiments and analyses in this emerging field. Our examples focus on using linear models in the study of human language and audition. We show how to calculate auditory receptive fields from natural sounds as well as how to decode neural recordings to predict speech. The paper aims to be a useful tutorial to these approaches, and a practical introduction to using machine learning and applied statistics to build models of neural activity. The data analytic approaches we discuss may also be applied to other sensory modalities, motor systems, and cognitive systems, and we cover some examples in these areas. In addition, a collection of Jupyter notebooks is publicly available as a complement to the material covered in this paper, providing code examples and tutorials for predictive modeling in python. The aim is to provide a practical understanding of predictive modeling of human brain data and to propose best-practices in conducting these analyses.

  3. Encoding and Decoding Models in Cognitive Electrophysiology

    Science.gov (United States)

    Holdgraf, Christopher R.; Rieger, Jochem W.; Micheli, Cristiano; Martin, Stephanie; Knight, Robert T.; Theunissen, Frederic E.

    2017-01-01

    Cognitive neuroscience has seen rapid growth in the size and complexity of data recorded from the human brain as well as in the computational tools available to analyze this data. This data explosion has resulted in an increased use of multivariate, model-based methods for asking neuroscience questions, allowing scientists to investigate multiple hypotheses with a single dataset, to use complex, time-varying stimuli, and to study the human brain under more naturalistic conditions. These tools come in the form of “Encoding” models, in which stimulus features are used to model brain activity, and “Decoding” models, in which neural features are used to generated a stimulus output. Here we review the current state of encoding and decoding models in cognitive electrophysiology and provide a practical guide toward conducting experiments and analyses in this emerging field. Our examples focus on using linear models in the study of human language and audition. We show how to calculate auditory receptive fields from natural sounds as well as how to decode neural recordings to predict speech. The paper aims to be a useful tutorial to these approaches, and a practical introduction to using machine learning and applied statistics to build models of neural activity. The data analytic approaches we discuss may also be applied to other sensory modalities, motor systems, and cognitive systems, and we cover some examples in these areas. In addition, a collection of Jupyter notebooks is publicly available as a complement to the material covered in this paper, providing code examples and tutorials for predictive modeling in python. The aim is to provide a practical understanding of predictive modeling of human brain data and to propose best-practices in conducting these analyses. PMID:29018336

  4. Use of CCSDS Packets Over SpaceWire to Control Hardware

    Science.gov (United States)

    Haddad, Omar; Blau, Michael; Haghani, Noosha; Yuknis, William; Albaijes, Dennis

    2012-01-01

    For the Lunar Reconnaissance Orbiter, the Command and Data Handling subsystem consisted of several electronic hardware assemblies that were connected with SpaceWire serial links. Electronic hardware would be commanded/controlled and telemetry data was obtained using the SpaceWire links. Prior art focused on parallel data buses and other types of serial buses, which were not compatible with the SpaceWire and the core flight executive (CFE) software bus. This innovation applies to anything that utilizes both SpaceWire networks and the CFE software. The CCSDS (Consultative Committee for Space Data Systems) packet contains predetermined values in its payload fields that electronic hardware attached at the terminus of the SpaceWire node would decode, interpret, and execute. The hardware s interpretation of the packet data would enable the hardware to change its state/configuration (command) or generate status (telemetry). The primary purpose is to provide an interface that is compatible with the hardware and the CFE software bus. By specifying the format of the CCSDS packet, it is possible to specify how the resulting hardware is to be built (in terms of digital logic) that results in a hardware design that can be controlled by the CFE software bus in the final application

  5. Locally decodable codes and private information retrieval schemes

    CERN Document Server

    Yekhanin, Sergey

    2010-01-01

    Locally decodable codes (LDCs) are codes that simultaneously provide efficient random access retrieval and high noise resilience by allowing reliable reconstruction of an arbitrary bit of a message by looking at only a small number of randomly chosen codeword bits. Local decodability comes with a certain loss in terms of efficiency - specifically, locally decodable codes require longer codeword lengths than their classical counterparts. Private information retrieval (PIR) schemes are cryptographic protocols designed to safeguard the privacy of database users. They allow clients to retrieve rec

  6. Turbo decoder architecture for beyond-4G applications

    CERN Document Server

    Wong, Cheng-Chi

    2013-01-01

    This book describes the most recent techniques for turbo decoder implementation, especially for 4G and beyond 4G applications. The authors reveal techniques for the design of high-throughput decoders for future telecommunication systems, enabling designers to reduce hardware cost and shorten processing time. Coverage includes an explanation of VLSI implementation of the turbo decoder, from basic functional units to advanced parallel architecture. The authors discuss both hardware architecture techniques and experimental results, showing the variations in area/throughput/performance with respec

  7. Multiple LDPC decoding for distributed source coding and video coding

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Luong, Huynh Van; Huang, Xin

    2011-01-01

    Distributed source coding (DSC) is a coding paradigm for systems which fully or partly exploit the source statistics at the decoder to reduce the computational burden at the encoder. Distributed video coding (DVC) is one example. This paper considers the use of Low Density Parity Check Accumulate...... (LDPCA) codes in a DSC scheme with feed-back. To improve the LDPC coding performance in the context of DSC and DVC, while retaining short encoder blocks, this paper proposes multiple parallel LDPC decoding. The proposed scheme passes soft information between decoders to enhance performance. Experimental...

  8. Plasma chemistry in wire chambers

    Energy Technology Data Exchange (ETDEWEB)

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed.

  9. Study of bifurcation behavior of two-dimensional turbo product code decoders

    Energy Technology Data Exchange (ETDEWEB)

    He Yejun [Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hunghom, Hong Kong (China); Lau, Francis C.M. [Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hunghom, Hong Kong (China)], E-mail: encmlau@polyu.edu.hk; Tse, Chi K. [Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hunghom, Hong Kong (China)

    2008-04-15

    Turbo codes, low-density parity-check (LDPC) codes and turbo product codes (TPCs) are high performance error-correction codes which employ iterative algorithms for decoding. Under different conditions, the behaviors of the decoders are different. While the nonlinear dynamical behaviors of turbo code decoders and LDPC decoders have been reported in the literature, the dynamical behavior of TPC decoders is relatively unexplored. In this paper, we investigate the behavior of the iterative algorithm of a two-dimensional TPC decoder when the input signal-to-noise ratio (SNR) varies. The quantity to be measured is the mean square value of the posterior probabilities of the information bits. Unlike turbo decoders or LDPC decoders, TPC decoders do not produce a clear 'waterfall region'. This is mainly because the TPC decoding algorithm does not converge to 'indecisive' fixed points even at very low SNR values.

  10. Decoding Reed-Solomon Codes beyond half the minimum distance

    DEFF Research Database (Denmark)

    Høholdt, Tom; Nielsen, Rasmus Refslund

    1999-01-01

    We describe an efficient implementation of M.Sudan"s algorithm for decoding Reed-Solomon codes beyond half the minimum distance. Furthermore we calculate an upper bound of the probabilty of getting more than one codeword as output...

  11. ENHANCEMENT OF ITERATIVE TURBO DECODING FOR HARQ SYSTEMS

    National Research Council Canada - National Science Library

    Imed Amamra; Nadir Derouiche

    2016-01-01

    .... The simulation results of the proposed stopping criterion show an interesting application in a hybrid automatic repeat request systems with turbo coding scheme, where the decoding complexity can be fairly reduced...

  12. Evolution of Neural Computations: Mantis Shrimp and Human Color Decoding

    Directory of Open Access Journals (Sweden)

    Qasim Zaidi

    2014-10-01

    Full Text Available Mantis shrimp and primates both possess good color vision, but the neural implementation in the two species is very different, a reflection of the largely unrelated evolutionary lineages of these creatures. Mantis shrimp have scanning compound eyes with 12 classes of photoreceptors, and have evolved a system to decode color information at the front-end of the sensory stream. Primates have image-focusing eyes with three classes of cones, and decode color further along the visual-processing hierarchy. Despite these differences, we report a fascinating parallel between the computational strategies at the color-decoding stage in the brains of stomatopods and primates. Both species appear to use narrowly tuned cells that support interval decoding color identification.

  13. On Complexity, Energy- and Implementation-Efficiency of Channel Decoders

    CERN Document Server

    Kienle, Frank; Meyr, Heinrich

    2010-01-01

    Future wireless communication systems require efficient and flexible baseband receivers. Meaningful efficiency metrics are key for design space exploration to quantify the algorithmic and the implementation complexity of a receiver. Most of the current established efficiency metrics are based on counting operations, thus neglecting important issues like data and storage complexity. In this paper we introduce suitable energy and area efficiency metrics which resolve the afore-mentioned disadvantages. These are decoded information bit per energy and throughput per area unit. Efficiency metrics are assessed by various implementations of turbo decoders, LDPC decoders and convolutional decoders. New exploration methodologies are presented, which permit an appropriate benchmarking of implementation efficiency, communications performance, and flexibility trade-offs. These exploration methodologies are based on efficiency trajectories rather than a single snapshot metric as done in state-of-the-art approaches.

  14. FPGA Prototyping of RNN Decoder for Convolutional Codes

    National Research Council Canada - National Science Library

    Salcic, Zoran; Berber, Stevan; Secker, Paul

    2006-01-01

    This paper presents prototyping of a recurrent type neural network (RNN) convolutional decoder using system-level design specification and design flow that enables easy mapping to the target FPGA architecture...

  15. Impact of Decoding Work within a Professional Program

    Science.gov (United States)

    Yeo, Michelle; Lafave, Mark; Westbrook, Khatija; McAllister, Jenelle; Valdez, Dennis; Eubank, Breda

    2017-01-01

    This chapter demonstrates how Decoding work can be used productively within a curriculum change process to help make design decisions based on a more nuanced understanding of student learning and the relationship of a professional program to the field.

  16. Cavity Mode Related Wire Breaking of the SPS Wire Scanners and Loss Measurements of Wire Materials

    CERN Document Server

    Caspers, Friedhelm; Jensen, E; Koopman, J; Malo, J F; Roncarolo, F

    2003-01-01

    During the SPS high intensity run 2002 with LHC type beam, the breaking of several of the carbon wires in the wire scanners has been observed in their parking position. The observation of large changes in the wire resistivity and thermionic electron emission clearly indicated strong RF heating that was depending on the bunch length. A subsequent analysis in the laboratory, simulating the beam by two probe antennas or by a powered stretched wire, showed two main problems: i) the housing of the wire scanner acts as a cavity with a mode spectrum starting around 350 MHz and high impedance values around 700 MHz; ii) the carbon wire used so far appears to be an excellent RF absorber and thus dissipates a significant part of the beam-induced power. Different wire materials are compared with the classical cavity mode technique for the determination of the complex permittivity in the range of 2-4 GHz. As a resonator a rectangular TE_01n type device is utilized.

  17. Cavity mode related wire breaking of the SPS Wire Scanners and loss measurements of wire materials

    CERN Document Server

    Roncarolo, Federico

    2003-01-01

    During the SPS high intensity run 2002 with LHC type beam, the breaking of several of the carbon wires in the wire scanners has been observed in their parking position. The observation of large changes in the wire resistivity and thermionic electron emission clearly indicated strong RF heating that was depending on the bunch length. A subsequent analysis in the laboratory, simulating the beam by two probe antennas or by a powered stretched wire, showed two main problems: i) the housing of the wire scanner acts as a cavity with a mode spectrum starting around 350MHz and high impedance values around 700 MHz; ii) the carbon wire used so far appears to be an excellent RF absorber and thus dissipates a significant part of the beam-induced power. Different wire materials are compared with the classical cavity mode technique for the determination of the complex permittivity in the range of 2-4 GHz. As a resonator a rectangular TE01n type device is utilized.

  18. Conceptual design for a universal Reed-Solomon decoder

    Science.gov (United States)

    Miller, R. L.; Deutsch, L. J.

    1981-01-01

    An algorithm which enables one Reed-Solomon decoder to process other Reed-Solomon encoded data from a different code is presented. The sole requirement is that both codes have the same length, the same rate, and the same field of coefficients. It is pointed out that only very simple pre- and post-processing hardware is needed to resolve an encoder/decoder incompatibility and that no encoder modification is needed.

  19. Modeling birds on wires.

    Science.gov (United States)

    Aydoğdu, A; Frasca, P; D'Apice, C; Manzo, R; Thornton, J M; Gachomo, B; Wilson, T; Cheung, B; Tariq, U; Saidel, W; Piccoli, B

    2017-02-21

    In this paper we introduce a mathematical model to study the group dynamics of birds resting on wires. The model is agent-based and postulates attraction-repulsion forces between the interacting birds: the interactions are "topological", in the sense that they involve a given number of neighbors irrespective of their distance. The model is first mathematically analyzed and then simulated to study its main properties: we observe that the model predicts birds to be more widely spaced near the borders of each group. We compare the results from the model with experimental data, derived from the analysis of pictures of pigeons and starlings taken in New Jersey: two different image elaboration protocols allow us to establish a good agreement with the model and to quantify its main parameters. We also discuss the potential handedness of the birds, by analyzing the group organization features and the group dynamics at the arrival of new birds. Finally, we propose a more refined mathematical model that describes landing and departing birds by suitable stochastic processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Partially blind instantly decodable network codes for lossy feedback environment

    KAUST Repository

    Sorour, Sameh

    2014-09-01

    In this paper, we study the multicast completion and decoding delay minimization problems for instantly decodable network coding (IDNC) in the case of lossy feedback. When feedback loss events occur, the sender falls into uncertainties about packet reception at the different receivers, which forces it to perform partially blind selections of packet combinations in subsequent transmissions. To determine efficient selection policies that reduce the completion and decoding delays of IDNC in such an environment, we first extend the perfect feedback formulation in our previous works to the lossy feedback environment, by incorporating the uncertainties resulting from unheard feedback events in these formulations. For the completion delay problem, we use this formulation to identify the maximum likelihood state of the network in events of unheard feedback and employ it to design a partially blind graph update extension to the multicast IDNC algorithm in our earlier work. For the decoding delay problem, we derive an expression for the expected decoding delay increment for any arbitrary transmission. This expression is then used to find the optimal policy that reduces the decoding delay in such lossy feedback environment. Results show that our proposed solutions both outperform previously proposed approaches and achieve tolerable degradation even at relatively high feedback loss rates.

  1. Evaluation framework for K-best sphere decoders

    KAUST Repository

    Shen, Chungan

    2010-08-01

    While Maximum-Likelihood (ML) is the optimum decoding scheme for most communication scenarios, practical implementation difficulties limit its use, especially for Multiple Input Multiple Output (MIMO) systems with a large number of transmit or receive antennas. Tree-searching type decoder structures such as Sphere decoder and K-best decoder present an interesting trade-off between complexity and performance. Many algorithmic developments and VLSI implementations have been reported in literature with widely varying performance to area and power metrics. In this semi-tutorial paper we present a holistic view of different Sphere decoding techniques and K-best decoding techniques, identifying the key algorithmic and implementation trade-offs. We establish a consistent benchmark framework to investigate and compare the delay cost, power cost, and power-delay-product cost incurred by each method. Finally, using the framework, we propose and analyze a novel architecture and compare that to other published approaches. Our goal is to explicitly elucidate the overall advantages and disadvantages of each proposed algorithms in one coherent framework. © 2010 World Scientific Publishing Company.

  2. Indirect decoding edges for one-shot shape acquisition.

    Science.gov (United States)

    Zhang, Xu; Zhu, Limin; Li, Youfu

    2011-04-01

    Determining the correspondence in coded structured light is challenging, but it is very important in one-shot techniques for 3D shape reconstruction. The problem of decoding stripe patterns can be modeled as matching two code sequences. We propose decoding edges indirectly based on the property of the stripe pattern, which can be represented as edge code, color code, or mixed code sequences. While traditional methods match two edge code sequences, indirect decoding matches two color sequences or mixed code sequences. The advantages of the proposed method, including a higher Hamming distance, enforced local coherence, and more code information, make indirect decoding excellent in performance. Previously, the lack of ground truth has prevented direct comparisons of different decoding algorithms. Here we obtain six benchmark datasets using the robust space-time analysis. Five decoding methods are quantitatively evaluated using the ground truth. The comparison results show that our method is robust for complex code situations and that it outperforms the state-of-the-art technique in this area. © 2011 Optical Society of America

  3. Topology Optimized Photonic Wire Splitters

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Jensen, Jakob Søndergaard

    2006-01-01

    Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm.......Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm....

  4. HTS Wire Development Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  5. 30 CFR 75.701-4 - Grounding wires; capacity of wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding wires; capacity of wires. 75.701-4... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.701-4 Grounding wires; capacity of wires. Where grounding wires are used to ground metallic sheaths, armors, conduits, frames...

  6. 1 mil gold bond wire study.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  7. Decoding the mechanical fingerprints of biomolecules.

    Science.gov (United States)

    Dudko, Olga K

    2016-01-01

    The capacity of biological macromolecules to act as exceedingly sophisticated and highly efficient cellular machines - switches, assembly factors, pumps, or motors - is realized through their conformational transitions, that is, their folding into distinct shapes and selective binding to other molecules. Conformational transitions can be induced, monitored, and manipulated by pulling individual macromolecules apart with an applied force. Pulling experiments reveal, for a given biomolecule, the relationship between applied force and molecular extension. Distinct signatures in the force-extension relationship identify a given biomolecule and thus serve as the molecule's 'mechanical fingerprints'. But, how can these fingerprints be decoded to uncover the energy barriers crossed by the molecule in the course of its conformational transition, as well as the associated timescales? This review summarizes a powerful class of approaches to interpreting single-molecule force spectroscopy measurements - namely, analytically tractable approaches. On the fundamental side, analytical theories have the power to reveal the unifying principles underneath the bewildering diversity of biomolecules and their behaviors. On the practical side, analytical expressions that result from these theories are particularly well suited for a direct fit to experimental data, yielding the important parameters that govern biological processes at the molecular level.

  8. Rate Aware Instantly Decodable Network Codes

    KAUST Repository

    Douik, Ahmed

    2016-02-26

    This paper addresses the problem of reducing the delivery time of data messages to cellular users using instantly decodable network coding (IDNC) with physical-layer rate awareness. While most of the existing literature on IDNC does not consider any physical layer complications, this paper proposes a cross-layer scheme that incorporates the different channel rates of the various users in the decision process of both the transmitted message combinations and the rates with which they are transmitted. The completion time minimization problem in such scenario is first shown to be intractable. The problem is, thus, approximated by reducing, at each transmission, the increase of an anticipated version of the completion time. The paper solves the problem by formulating it as a maximum weight clique problem over a newly designed rate aware IDNC (RA-IDNC) graph. Further, the paper provides a multi-layer solution to improve the completion time approximation. Simulation results suggest that the cross-layer design largely outperforms the uncoded transmissions strategies and the classical IDNC scheme. © 2015 IEEE.

  9. fNIRS-based online deception decoding

    Science.gov (United States)

    Hu, Xiao-Su; Hong, Keum-Shik; Ge, Shuzhi Sam

    2012-04-01

    Deception involves complex neural processes in the brain. Different techniques have been used to study and understand brain mechanisms during deception. Moreover, efforts have been made to develop schemes that can detect and differentiate deception and truth-telling. In this paper, a functional near-infrared spectroscopy (fNIRS)-based online brain deception decoding framework is developed. Deploying dual-wavelength fNIRS, we interrogate 16 locations in the forehead when eight able-bodied adults perform deception and truth-telling scenarios separately. By combining preprocessed oxy-hemoglobin and deoxy-hemoglobin signals, we develop subject-specific classifiers using the support vector machine. Deception and truth-telling states are classified correctly in seven out of eight subjects. A control experiment is also conducted to verify the deception-related hemodynamic response. The average classification accuracy is over 83.44% from these seven subjects. The obtained result suggests that the applicability of fNIRS as a brain imaging technique for online deception detection is very promising.

  10. Fast mental states decoding in mixed reality.

    Science.gov (United States)

    De Massari, Daniele; Pacheco, Daniel; Malekshahi, Rahim; Betella, Alberto; Verschure, Paul F M J; Birbaumer, Niels; Caria, Andrea

    2014-01-01

    The combination of Brain-Computer Interface (BCI) technology, allowing online monitoring and decoding of brain activity, with virtual and mixed reality (MR) systems may help to shape and guide implicit and explicit learning using ecological scenarios. Real-time information of ongoing brain states acquired through BCI might be exploited for controlling data presentation in virtual environments. Brain states discrimination during mixed reality experience is thus critical for adapting specific data features to contingent brain activity. In this study we recorded electroencephalographic (EEG) data while participants experienced MR scenarios implemented through the eXperience Induction Machine (XIM). The XIM is a novel framework modeling the integration of a sensing system that evaluates and measures physiological and psychological states with a number of actuators and effectors that coherently reacts to the user's actions. We then assessed continuous EEG-based discrimination of spatial navigation, reading and calculation performed in MR, using linear discriminant analysis (LDA) and support vector machine (SVM) classifiers. Dynamic single trial classification showed high accuracy of LDA and SVM classifiers in detecting multiple brain states as well as in differentiating between high and low mental workload, using a 5 s time-window shifting every 200 ms. Our results indicate overall better performance of LDA with respect to SVM and suggest applicability of our approach in a BCI-controlled MR scenario. Ultimately, successful prediction of brain states might be used to drive adaptation of data representation in order to boost information processing in MR.

  11. Fast mental states decoding in mixed reality.

    Directory of Open Access Journals (Sweden)

    Daniele eDe Massari

    2014-11-01

    Full Text Available The combination of Brain-Computer Interface technology, allowing online monitoring and decoding of brain activity, with virtual and mixed reality systems may help to shape and guide implicit and explicit learning using ecological scenarios. Real-time information of ongoing brain states acquired through BCI might be exploited for controlling data presentation in virtual environments. In this context, assessing to what extent brain states can be discriminated during mixed reality experience is critical for adapting specific data features to contingent brain activity. In this study we recorded EEG data while participants experienced a mixed reality scenario implemented through the eXperience Induction Machine (XIM. The XIM is a novel framework modeling the integration of a sensing system that evaluates and measures physiological and psychological states with a number of actuators and effectors that coherently reacts to the user's actions. We then assessed continuous EEG-based discrimination of spatial navigation, reading and calculation performed in mixed reality, using LDA and SVM classifiers. Dynamic single trial classification showed high accuracy of LDA and SVM classifiers in detecting multiple brain states as well as in differentiating between high and low mental workload, using a 5 s time-window shifting every 200 ms. Our results indicate overall better performance of LDA with respect to SVM and suggest applicability of our approach in a BCI-controlled mixed reality scenario. Ultimately, successful prediction of brain states might be used to drive adaptation of data representation in order to boost information processing in mixed reality.

  12. Decoding reality the universe as quantum information

    CERN Document Server

    Vedral, Vlatko

    2010-01-01

    In Decoding Reality, Vlatko Vedral offers a mind-stretching look at the deepest questions about the universe--where everything comes from, why things are as they are, what everything is. The most fundamental definition of reality is not matter or energy, he writes, but information--and it is the processing of information that lies at the root of all physical, biological, economic, and social phenomena. This view allows Vedral to address a host of seemingly unrelated questions: Why does DNA bind like it does? What is the ideal diet for longevity? How do you make your first million dollars? We can unify all through the understanding that everything consists of bits of information, he writes, though that raises the question of where these bits come from. To find the answer, he takes us on a guided tour through the bizarre realm of quantum physics. At this sub-sub-subatomic level, we find such things as the interaction of separated quantum particles--what Einstein called "spooky action at a distance." In fact, V...

  13. Singer product apertures—A coded aperture system with a fast decoding algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Byard, Kevin, E-mail: kevin.byard@aut.ac.nz [School of Economics, Faculty of Business, Economics and Law, Auckland University of Technology, Auckland 1142 (New Zealand); Shutler, Paul M.E. [National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore)

    2017-06-01

    A new type of coded aperture configuration that enables fast decoding of the coded aperture shadowgram data is presented. Based on the products of incidence vectors generated from the Singer difference sets, we call these Singer product apertures. For a range of aperture dimensions, we compare experimentally the performance of three decoding methods: standard decoding, induction decoding and direct vector decoding. In all cases the induction and direct vector methods are several orders of magnitude faster than the standard method, with direct vector decoding being significantly faster than induction decoding. For apertures of the same dimensions the increase in speed offered by direct vector decoding over induction decoding is better for lower throughput apertures.

  14. An FPGA Implementation of -Regular Low-Density Parity-Check Code Decoder

    Directory of Open Access Journals (Sweden)

    Parhi Keshab K

    2003-01-01

    Full Text Available Because of their excellent error-correcting performance, low-density parity-check (LDPC codes have recently attracted a lot of attention. In this paper, we are interested in the practical LDPC code decoder hardware implementations. The direct fully parallel decoder implementation usually incurs too high hardware complexity for many real applications, thus partly parallel decoder design approaches that can achieve appropriate trade-offs between hardware complexity and decoding throughput are highly desirable. Applying a joint code and decoder design methodology, we develop a high-speed -regular LDPC code partly parallel decoder architecture based on which we implement a -bit, rate- -regular LDPC code decoder on Xilinx FPGA device. This partly parallel decoder supports a maximum symbol throughput of Mbps and achieves BER at 2 dB over AWGN channel while performing maximum decoding iterations.

  15. Correlated atomic wires on substrates. II. Application to Hubbard wires

    Science.gov (United States)

    Abdelwahab, Anas; Jeckelmann, Eric; Hohenadler, Martin

    2017-07-01

    In the first part of our theoretical study of correlated atomic wires on substrates, we introduced lattice models for a one-dimensional quantum wire on a three-dimensional substrate and their approximation by quasi-one-dimensional effective ladder models [Abdelwahab et al., preceding paper, Phys. Rev. B 96, 035445 (2017), 10.1103/PhysRevB.96.035445]. In this second part, we apply this approach to the case of a correlated wire with a Hubbard-type electron-electron repulsion deposited on an insulating substrate. The ground-state and spectral properties are investigated numerically using the density-matrix renormalization group method and quantum Monte Carlo simulations. As a function of the model parameters, we observe various phases with quasi-one-dimensional low-energy excitations localized in the wire, namely, paramagnetic Mott insulators, Luttinger liquids, and spin-1 /2 Heisenberg chains. The validity of the effective ladder models is assessed for selected parameters by studying the dependence of results on the number of legs and comparing to the full three-dimensional model. We find that narrow ladder models accurately reproduce the quasi-one-dimensional excitations of the full three-dimensional model but predict only qualitatively whether excitations are localized around the wire or delocalized in the three-dimensional substrate.

  16. Unbiased decoding of biologically motivated visual feature descriptors

    Directory of Open Access Journals (Sweden)

    Michael eFelsberg

    2015-08-01

    Full Text Available Visual feature descriptors are essential elements in most computer and robot vision systems. They typically lead to an abstraction of the input data, images or video, for further processing such as clustering and machine learning. In clustering applications, the cluster center represents the prototypical descriptor of the cluster and estimating the corresponding signal value, such as color value or dominating flow orientation, by decoding the prototypical descriptor, is essential. Machine learning applications determine the relevance of respective descriptors and a visualization of the corresponding decoded information is very useful for the analysis of the learning algorithm. Thus decoding of feature descriptors is a relevant problem, frequently addressed in recent work.Also the human brain represents sensorimotor information at a suitable abstraction level through varying activation of neuron populations. Approximative computational models have been derived that confirm neurophysiological experiments on the representation of visual information by decoding the underlying signals. However, the represented variables have a bias towards centers or boundaries of the tuning curves. Despite the fact that feature descriptors in computer vision are motivated from neuroscience, the respective decoding methods have been derived largely independent.From first order principles, we derive unbiased decoding schemes for biologically motivated feature descriptors with a minimum amount of redundancy and suitable invariance properties. These descriptors establish a non-parametric density estimation of the underlying stochastic process with a particular algebraic structure. Based on the resulting algebraic constraints, we show formally how the decoding problem is formulated as an unbiased maximum likelihood estimator and we derive a recurrent inverse diffusion scheme to infer the dominating mode of the distribution. These methods are evaluated and compared to

  17. Wire chambers revisited.

    Science.gov (United States)

    Ott, R J

    1993-04-01

    Detectors used for radioisotope imaging have, historically, been based on scintillating crystal/photomultiplier combinations in various forms. From the rectilinear scanner through to modern gamma cameras and positron cameras, the basic technology has remained much the same. Efforts to overcome the limitations of this form of technology have foundered on the inability to reproduce the required sensitivity, spatial resolution and sensitive area at acceptable cost. Multiwire proportional chambers (MWPCs) have long been used as position-sensitive charged particle detectors in nuclear and high-energy physics. MWPCs are large-area gas-filled ionisation chambers in which large arrays of fine wires are used to measure the position of ionisation produced in the gas by the passage of charged particles. The important properties of MWPCs are high-spatial-resolution, large-area, high-count-rate performance at low cost. For research applications, detectors several metres square have been built and small-area detectors have a charged particle resolution of 0.4 mm at a count rate of several million per second. Modification is required to MWPCs for nuclear medicine imaging. As gamma rays or X-rays cannot be detected directly, they must be converted into photo- or Compton scatter electrons. Photon-electron conversion requires the use of high atomic number materials in the body of the chamber. Pressurised xenon is the most useful form of "gas only" photon-electron convertor and has been used successfully in a gamma camera for the detection of gamma rays at energies below 100 keV. This camera has been developed specifically for high-count-rate first-pass cardiac imaging. This high-pressure xenon gas MWPC is the key to a highly competitive system which can outperform scintillator-based systems. The count rate performance is close to a million counts per second and the intrinsic spatial resolution is better than the best scintillator-based camera. The MWPC camera produces quantitative

  18. Continuous BP Decoding Algorithm for a Low-Density Parity-Check Coded Hybrid ARQ System

    Science.gov (United States)

    Park, Sangjoon; Choi, Sooyong; Hwang, Seung-Hoon

    A continuous belief propagation (BP) decoding algorithm for a hybrid automatic repeat request (ARQ) system is proposed in this paper. The proposed continuous BP decoding algorithm utilizes the extrinsic information generated in the last iteration of the previous transmission for a continuous progression of the decoding through retransmissions. This allows the continuous BP decoding algorithm to accelerate the decoding convergence for codeword determination, especially when the number of retransmissions is large or a currently combined packet has punctured nodes. Simulation results verify the effectiveness of the proposed continuous BP decoding algorithm.

  19. Plasma arc torch with coaxial wire feed

    Science.gov (United States)

    Hooper, Frederick M

    2002-01-01

    A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

  20. Ocular dangers of fencing wire.

    Science.gov (United States)

    McAllum, P; Barnes, R; Dickson, J

    2001-07-27

    To invesitgate the incidence and severity of penetrating eye injuries caused by fencing wire in the Waikato region. We reviewed the case notes for all penetrating eye injuries treated at Waikato Hospital during the past six years. Parameters recorded were patient age and sex, mechanism of injury, initial visual acuity, characteristics of injury, surgery performed and final visual outcome. The incidence of penetrating eye injuries in the Waikato region was 3.8 per 100,000 per year, based on an estimated catchment population of 350,000. We found fencing wire to be the third most common cause of penetrating eye injury, accounting for 8.8% of injuries, behind motor vehicle accidents and hammering which accounted for 26.3% and 20.0% of injuries, respectively. The fencing wire injuries involved men exclusively, with an average age of 41.7 years. Fencing wire injuries had worse presenting visual acuity than other injuries, involved the posterior segment of the eye more frequently and were more likely to develop bacterial endophthalmitis. They also underwent more surgical procedures and were more commonly associated with a poor visual outcome. Fencing wire is an important cause of visual loss in the Waikato region. We hope to raise awareness of its potential ocular dangers and to promote the use of appropriate eye protection.

  1. Taste quality decoding parallels taste sensations.

    Science.gov (United States)

    Crouzet, Sébastien M; Busch, Niko A; Ohla, Kathrin

    2015-03-30

    In most species, the sense of taste is key in the distinction of potentially nutritious and harmful food constituents and thereby in the acceptance (or rejection) of food. Taste quality is encoded by specialized receptors on the tongue, which detect chemicals corresponding to each of the basic tastes (sweet, salty, sour, bitter, and savory [1]), before taste quality information is transmitted via segregated neuronal fibers [2], distributed coding across neuronal fibers [3], or dynamic firing patterns [4] to the gustatory cortex in the insula. In rodents, both hardwired coding by labeled lines [2] and flexible, learning-dependent representations [5] and broadly tuned neurons [6] seem to coexist. It is currently unknown how, when, and where taste quality representations are established in the cortex and whether these representations are used for perceptual decisions. Here, we show that neuronal response patterns allow to decode which of four tastants (salty, sweet, sour, and bitter) participants tasted in a given trial by using time-resolved multivariate pattern analyses of large-scale electrophysiological brain responses. The onset of this prediction coincided with the earliest taste-evoked responses originating from the insula and opercular cortices, indicating that quality is among the first attributes of a taste represented in the central gustatory system. These response patterns correlated with perceptual decisions of taste quality: tastes that participants discriminated less accurately also evoked less discriminated brain response patterns. The results therefore provide the first evidence for a link between taste-related decision-making and the predictive value of these brain response patterns. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Nonlinear EEG Decoding Based on a Particle Filter Model

    Directory of Open Access Journals (Sweden)

    Jinhua Zhang

    2014-01-01

    Full Text Available While the world is stepping into the aging society, rehabilitation robots play a more and more important role in terms of both rehabilitation treatment and nursing of the patients with neurological diseases. Benefiting from the abundant contents of movement information, electroencephalography (EEG has become a promising information source for rehabilitation robots control. Although the multiple linear regression model was used as the decoding model of EEG signals in some researches, it has been considered that it cannot reflect the nonlinear components of EEG signals. In order to overcome this shortcoming, we propose a nonlinear decoding model, the particle filter model. Two- and three-dimensional decoding experiments were performed to test the validity of this model. In decoding accuracy, the results are comparable to those of the multiple linear regression model and previous EEG studies. In addition, the particle filter model uses less training data and more frequency information than the multiple linear regression model, which shows the potential of nonlinear decoding models. Overall, the findings hold promise for the furtherance of EEG-based rehabilitation robots.

  3. Robust pattern decoding in shape-coded structured light

    Science.gov (United States)

    Tang, Suming; Zhang, Xu; Song, Zhan; Song, Lifang; Zeng, Hai

    2017-09-01

    Decoding is a challenging and complex problem in a coded structured light system. In this paper, a robust pattern decoding method is proposed for the shape-coded structured light in which the pattern is designed as grid shape with embedded geometrical shapes. In our decoding method, advancements are made at three steps. First, a multi-template feature detection algorithm is introduced to detect the feature point which is the intersection of each two orthogonal grid-lines. Second, pattern element identification is modelled as a supervised classification problem and the deep neural network technique is applied for the accurate classification of pattern elements. Before that, a training dataset is established, which contains a mass of pattern elements with various blurring and distortions. Third, an error correction mechanism based on epipolar constraint, coplanarity constraint and topological constraint is presented to reduce the false matches. In the experiments, several complex objects including human hand are chosen to test the accuracy and robustness of the proposed method. The experimental results show that our decoding method not only has high decoding accuracy, but also owns strong robustness to surface color and complex textures.

  4. Neural decoding of single vowels during covert articulation using electrocorticography.

    Science.gov (United States)

    Ikeda, Shigeyuki; Shibata, Tomohiro; Nakano, Naoki; Okada, Rieko; Tsuyuguchi, Naohiro; Ikeda, Kazushi; Kato, Amami

    2014-01-01

    The human brain has important abilities for manipulating phonemes, the basic building blocks of speech; these abilities represent phonological processing. Previous studies have shown change in the activation levels of broad cortical areas such as the premotor cortex, the inferior frontal gyrus, and the superior temporal gyrus during phonological processing. However, whether these areas actually convey signals to representations related to individual phonemes remains unclear. This study focused on single vowels and investigated cortical areas important for representing single vowels using electrocorticography (ECoG) during covert articulation. To identify such cortical areas, we used a neural decoding approach in which machine learning models identify vowels. A decoding model was trained on the ECoG signals from individual electrodes placed on the subjects' cortices. We then statistically evaluated whether each decoding model showed accurate identification of vowels, and we found cortical areas such as the premotor cortex and the superior temporal gyrus. These cortical areas were consistent with previous findings. On the other hand, no electrodes over Broca's area showed significant decoding accuracies. This was inconsistent with findings from a previous study showing that vowels within the phonemic sequence of words can be decoded using ECoG signals from Broca's area. Our results therefore suggest that Broca's area is involved in the processing of vowels within phonemic sequences, but not in the processing of single vowels.

  5. High resolution decoding of Multi-Anode Microchannel Array detectors

    Science.gov (United States)

    Kasle, David B.; Morgan, Jeffrey S.

    1991-01-01

    The Multi-Anode Microchannel Array (MAMA) is a photon counting detector which utilizes a photocathode for photon to electron conversion, a microchannel plate (MCP) for signal amplification and a proximity focused anode array for position sensitivity. The detector electronics decode the position of an event through coincidence discrimination. The decoding algorithm which associates a given event with the appropriate pixel is determined by the geometry of the array. A new algorithm incorporated into a CMOS Application Specific Integrated Circuit (ASIC) decoder which improves the pixel spatial resolution is described. The new algorithm does not degrade the detector throughput and does not require any modifications to the detector tube. The standard MAMA detector has a pixel size of 25 x 25 square microns, but with the new decoder circuit the pixel size is reduced to 12.5 x 12.5 square microns. We have built the first set of decode electronics utilizing the new ASIC chips and report here on the first imaging tests of this system.

  6. Distributed Coding/Decoding Complexity in Video Sensor Networks

    Science.gov (United States)

    Cordeiro, Paulo J.; Assunção, Pedro

    2012-01-01

    Video Sensor Networks (VSNs) are recent communication infrastructures used to capture and transmit dense visual information from an application context. In such large scale environments which include video coding, transmission and display/storage, there are several open problems to overcome in practical implementations. This paper addresses the most relevant challenges posed by VSNs, namely stringent bandwidth usage and processing time/power constraints. In particular, the paper proposes a novel VSN architecture where large sets of visual sensors with embedded processors are used for compression and transmission of coded streams to gateways, which in turn transrate the incoming streams and adapt them to the variable complexity requirements of both the sensor encoders and end-user decoder terminals. Such gateways provide real-time transcoding functionalities for bandwidth adaptation and coding/decoding complexity distribution by transferring the most complex video encoding/decoding tasks to the transcoding gateway at the expense of a limited increase in bit rate. Then, a method to reduce the decoding complexity, suitable for system-on-chip implementation, is proposed to operate at the transcoding gateway whenever decoders with constrained resources are targeted. The results show that the proposed method achieves good performance and its inclusion into the VSN infrastructure provides an additional level of complexity control functionality. PMID:22736972

  7. Weyl fermions in cylindrical wires

    Science.gov (United States)

    Erementchouk, Mikhail; Mazumder, Pinaki

    2018-01-01

    The key feature of Weyl semimetals (WSMs) is the presence of topologically protected Dirac cones in a three-dimensional material. We consider the effect of restricting geometry on the spectrum of excitations in WSMs using as a model a cylindrical WSM wire. For the full manifold of hard boundary conditions, we derive the general form of the dispersion equation relating the energy of the excitations and their momentum along the wire. We show that only the special class of boundary conditions, corresponding to decoupled helicities or, equivalently, to pinned directions of the electron spin on the surface, support massless excitations. For a general boundary condition, these excitations acquire mass inversely proportional to the radius of the wire. This demonstrates that boundary phenomena may play a crucial role in formation of excitations in WSM based structures.

  8. Analysis of Minimal LDPC Decoder System on a Chip Implementation

    Directory of Open Access Journals (Sweden)

    T. Palenik

    2015-09-01

    Full Text Available This paper presents a practical method of potential replacement of several different Quasi-Cyclic Low-Density Parity-Check (QC-LDPC codes with one, with the intention of saving as much memory as required to implement the LDPC encoder and decoder in a memory-constrained System on a Chip (SoC. The presented method requires only a very small modification of the existing encoder and decoder, making it suitable for utilization in a Software Defined Radio (SDR platform. Besides the analysis of the effects of necessary variable-node value fixation during the Belief Propagation (BP decoding algorithm, practical standard-defined code parameters are scrutinized in order to evaluate the feasibility of the proposed LDPC setup simplification. Finally, the error performance of the modified system structure is evaluated and compared with the original system structure by means of simulation.

  9. [Efficacy of decoding training for children with difficulty reading hiragana].

    Science.gov (United States)

    Uchiyama, Hitoshi; Tanaka, Daisuke; Seki, Ayumi; Wakamiya, Eiji; Hirasawa, Noriko; Iketani, Naotake; Kato, Ken; Koeda, Tatsuya

    2013-05-01

    The present study aimed to clarify the efficacy of decoding training focusing on the correspondence between written symbols and their readings for children with difficulty reading hiragana (Japanese syllabary). Thirty-five children with difficulty reading hiragana were selected from among 367 first-grade elementary school students using a reading aloud test and were then divided into intervention (n=15) and control (n=20) groups. The intervention comprised 5 minutes of decoding training each day for a period of 3 weeks using an original program on a personal computer. Reading time and number of reading errors in the reading aloud test were compared between the groups. The intervention group showed a significant shortening of reading time (F(1,33)=5.40, preading errors was observed (t= 2.863, preading time. Decoding training was found to be effective for improving both reading time and reading errors in children with difficulty reading hiragana.

  10. High-threshold decoding algorithms for the gauge color code

    Science.gov (United States)

    Zeng, William; Brown, Benjamin

    Gauge color codes are topological quantum error correcting codes on three dimensional lattices. They have garnered recent interest due to two important properties: (1) they admit a universal transversal gate set, and (2) their structure allows reliable error correction using syndrome data obtained from a measurement circuit of constant depth. Both of these properties make gauge color codes intriguing candidates for low overhead fault-tolerant quantum computation. Recent work by Brown et al. calculated a threshold of 0.31% for a particular gauge color code lattice using a simple clustering decoder and phenomenological noise. We show that we can achieve improved threshold error rates using the efficient Wootton and Loss Markov-chain Monte Carlo (MCMC) decoding. In the case of the surface code, the MCMC decoder produced a threshold close to that code's upper bound. While no upper bound is known for gauge color codes, the thresholds we present here may give a better estimate.

  11. Modified Suboptimal Iterative Decoding for Regular Repeat- Accumulate Coded Signals

    Directory of Open Access Journals (Sweden)

    Muhammad Thamer Nesr

    2017-05-01

    Full Text Available In this work, two algorithms are suggested in order to improve the performance of systematic Repeat-Accumulate ( decoding. The first one is accomplished by the insertion of pilot symbols among the data stream that entering the encoder. The positions where pilots should be inserted are chosen in such a way that to improve the minimum Hamming distance and/or to reduce the error coefficients of the code. The second proposed algorithm includes the utilization of the inserted pilots to estimate scaling (correction factors. Two-dimensional correction factor was suggested in order to enhance the performance of traditional Minimum-Sum decoding of regular repeat accumulate codes. An adaptive method can be achieved for getting the correction factors by calculating the mean square difference between the values of received pilots and the a-posteriori data of bit and check node related to them which created by the minimum-sum ( decoder

  12. Error-correction coding and decoding bounds, codes, decoders, analysis and applications

    CERN Document Server

    Tomlinson, Martin; Ambroze, Marcel A; Ahmed, Mohammed; Jibril, Mubarak

    2017-01-01

    This book discusses both the theory and practical applications of self-correcting data, commonly known as error-correcting codes. The applications included demonstrate the importance of these codes in a wide range of everyday technologies, from smartphones to secure communications and transactions. Written in a readily understandable style, the book presents the authors’ twenty-five years of research organized into five parts: Part I is concerned with the theoretical performance attainable by using error correcting codes to achieve communications efficiency in digital communications systems. Part II explores the construction of error-correcting codes and explains the different families of codes and how they are designed. Techniques are described for producing the very best codes. Part III addresses the analysis of low-density parity-check (LDPC) codes, primarily to calculate their stopping sets and low-weight codeword spectrum which determines the performance of these codes. Part IV deals with decoders desi...

  13. Time-Out Lattice Sequential Decoding for the MIMO ARQ Channel

    CERN Document Server

    Abediseid, Walid

    2011-01-01

    The optimal diversity-multiplexing-delay tradeoff for the multi-input multi-output (MIMO) automatic repeat request (ARQ) channel can be achieved using incremental redundancy lattice space-time codes coupled with a list decoder for joint error detection and correction. Such a decoder is based on the minimum mean-square error lattice decoding principle which is implemented using sphere decoding algorithms. However, sphere decoders suffer from high computational complexity for low-to-moderate signal-to-noise ratios, especially for large signal dimensions. In this paper, we would like to construct a more efficient decoder that is capable of achieving the optimal tradeoff with much lower complexity. In particular, we will study the throughput-performance-complexity tradeoffs in sequential decoding algorithms and the effect of preprocessing and termination strategies. We show, analytically and via simulation, that using the lattice sequential decoder that implements a time-out algorithm for joint error detection an...

  14. Subchannel Analysis of Wire Wrapped SCWR Assembly

    National Research Council Canada - National Science Library

    Shan, Jianqiang; Wang, Henan; Liu, Wei; Song, Linxing; Chen, Xuanxiang; Jiang, Yang

    2014-01-01

    .... The HPLWR wire wrapped assembly was analyzed. The results show that: (1) the assembly with wire wrap can obtain a more uniform coolant temperature profile than the grid spaced assembly, which will result in a lower peak cladding temperature; (2...

  15. Adaptive neuron-to-EMG decoder training for FES neuroprostheses

    Science.gov (United States)

    Ethier, Christian; Acuna, Daniel; Solla, Sara A.; Miller, Lee E.

    2016-08-01

    Objective. We have previously demonstrated a brain-machine interface neuroprosthetic system that provided continuous control of functional electrical stimulation (FES) and restoration of grasp in a primate model of spinal cord injury (SCI). Predicting intended EMG directly from cortical recordings provides a flexible high-dimensional control signal for FES. However, no peripheral signal such as force or EMG is available for training EMG decoders in paralyzed individuals. Approach. Here we present a method for training an EMG decoder in the absence of muscle activity recordings; the decoder relies on mapping behaviorally relevant cortical activity to the inferred EMG activity underlying an intended action. Monkeys were trained at a 2D isometric wrist force task to control a computer cursor by applying force in the flexion, extension, ulnar, and radial directions and execute a center-out task. We used a generic muscle force-to-endpoint force model based on muscle pulling directions to relate each target force to an optimal EMG pattern that attained the target force while minimizing overall muscle activity. We trained EMG decoders during the target hold periods using a gradient descent algorithm that compared EMG predictions to optimal EMG patterns. Main results. We tested this method both offline and online. We quantified both the accuracy of offline force predictions and the ability of a monkey to use these real-time force predictions for closed-loop cursor control. We compared both offline and online results to those obtained with several other direct force decoders, including an optimal decoder computed from concurrently measured neural and force signals. Significance. This novel approach to training an adaptive EMG decoder could make a brain-control FES neuroprosthesis an effective tool to restore the hand function of paralyzed individuals. Clinical implementation would make use of individualized EMG-to-force models. Broad generalization could be achieved by

  16. Transparency in nanophotonic quantum wires

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada)

    2009-03-28

    We have studied the quantum optics of a photonic quantum nanowire doped with an ensemble of three-level nanoparticles. The wire is made from two photonic crystals A and B. Crystal A is embedded within crystal B and acts as a photonic nanowire. It is considered that the conduction band of crystal A lies below that of crystal B. As a result, photons are confined in crystal A and are reflected from crystal B. The bound states of the confined photons are calculated using the transfer matrix method. It is found that the number of bound states in the wire depends on the size of the wire and the energy difference between the conduction band extrema of crystals A and B. The absorption coefficient of the system has also been calculated using the Schroedinger equation method. It is considered that the nanoparticles interact with the photonic bound states. Numerical simulations show that when one of the resonance energies lies near the bound state, the system becomes transparent. However, when the resonance energy lies away from the bound state the crystal reverts to an absorbing state. Similarly, when the radius of the dielectric spheres is changed the location of the transparency peak is shifted. This means that the present system can be switched between two states by changing the size of the wire and the transition energy. These findings can be used to make new types of optical devices.

  17. Signal shapes in a TPC wire chamber

    Science.gov (United States)

    Rossegger, S.; Riegler, W.

    2010-11-01

    We study signal shapes in Multi Wire Proportional Chambers (MWPCs) and the influence of the electron distribution around the wire on the ion tail characteristics. Simulations of the ion tail for two different geometries, different voltages and therefore gas gains were performed. These simulations are compared to measurements carried out with the ALICE TPC wire chambers for a Ne/CO 2/N 2 gas mixture, which allows to extract the avalanche spread around the anode wires of the MWPC.

  18. Towards Unconventional Applications of Wire Bonding

    OpenAIRE

    Schröder, Stephan

    2018-01-01

    This thesis presents novel heterogeneous integration approaches of wire materials to fabricated and package MEMS devices by exploring unconventional applications of wire bonding technology. Wire bonding, traditionally endemic in the realm of device packaging to establish electrical die-to-package interconnections, is an attractive back-end technology, offering promising features, such as high throughput, flexibility and placement accuracy. Exploiting the advantages of state-of-the-art wire bo...

  19. Novel Wiring Technologies for Aerospace Applications

    Science.gov (United States)

    Gibson, Tracy L.; Parrish, Lewis M.

    2014-01-01

    Because wire failure in aerospace vehicles could be catastrophic, smart wiring capabilities have been critical for NASA. Through the years, researchers at Kennedy Space Center (KSC) have developed technologies, expertise, and research facilities to meet this need. In addition to aerospace applications, NASA has applied its knowledge of smart wiring, including self-healing materials, to serve the aviation industry. This webinar will discuss the development efforts of several wiring technologies at KSC and provide insight into both current and future research objectives.

  20. Electron transport in stretched monoatomic gold wires.

    Science.gov (United States)

    Grigoriev, A; Skorodumova, N V; Simak, S I; Wendin, G; Johansson, B; Ahuja, R

    2006-12-08

    The conductance of monoatomic gold wires containing 3-7 gold atoms has been obtained from ab initio calculations. The transmission is found to vary significantly depending on the wire stretching and the number of incorporated atoms. Such oscillations are determined by the electronic structure of the one-dimensional (1D) part of the wire between the contacts. Our results indicate that the conductivity of 1D wires can be suppressed without breaking the contact.

  1. Detection of a buried wire with two resistively loaded wire antennas

    NARCIS (Netherlands)

    Vossen, S.H.J.A.; Tijhuis, A.G.; Lepelaars, E.S.A.M.; Zwamborn, A.P.M.

    2002-01-01

    The use of two identical straight thin-wire antennas for the detection of a buried wire is analyzed with the aid of numerical calculations. The buried wire is located below an interface between two homogeneous half-spaces. The detection setup, which is formed by a transmitting and a receiving wire,

  2. One century of Kirschner wires and Kirschner wire insertion techniques : A historical review

    NARCIS (Netherlands)

    Franssen, Bas B. G. M.; Schuurman, Arnold H.; Van der Molen, Aebele Mink; Kon, Moshe

    A century ago, in 1909, Martin Kirschner (1879-942) introduced a smooth pin, presently known as the Kirschner wire (K-wire). The K-wire was initiallly used for skeletal traction and is now currently used for many different goals. The development of the K-wire and its insertion devices were mainly

  3. Construction and decoding of matrix-product codes from nested codes

    DEFF Research Database (Denmark)

    Hernando, Fernando; Lally, Kristine; Ruano, Diego

    2009-01-01

    We consider matrix-product codes [C1 ... Cs] · A, where C1, ..., Cs  are nested linear codes and matrix A has full rank. We compute their minimum distance and provide a decoding algorithm when A is a non-singular by columns matrix. The decoding algorithm decodes up to half of the minimum distance....

  4. Progressive Image Transmission Based on Joint Source-Channel Decoding Using Adaptive Sum-Product Algorithm

    Directory of Open Access Journals (Sweden)

    David G. Daut

    2007-03-01

    Full Text Available A joint source-channel decoding method is designed to accelerate the iterative log-domain sum-product decoding procedure of LDPC codes as well as to improve the reconstructed image quality. Error resilience modes are used in the JPEG2000 source codec making it possible to provide useful source decoded information to the channel decoder. After each iteration, a tentative decoding is made and the channel decoded bits are then sent to the JPEG2000 decoder. The positions of bits belonging to error-free coding passes are then fed back to the channel decoder. The log-likelihood ratios (LLRs of these bits are then modified by a weighting factor for the next iteration. By observing the statistics of the decoding procedure, the weighting factor is designed as a function of the channel condition. Results show that the proposed joint decoding methods can greatly reduce the number of iterations, and thereby reduce the decoding delay considerably. At the same time, this method always outperforms the nonsource controlled decoding method by up to 3 dB in terms of PSNR.

  5. Progressive Image Transmission Based on Joint Source-Channel Decoding Using Adaptive Sum-Product Algorithm

    Directory of Open Access Journals (Sweden)

    Liu Weiliang

    2007-01-01

    Full Text Available A joint source-channel decoding method is designed to accelerate the iterative log-domain sum-product decoding procedure of LDPC codes as well as to improve the reconstructed image quality. Error resilience modes are used in the JPEG2000 source codec making it possible to provide useful source decoded information to the channel decoder. After each iteration, a tentative decoding is made and the channel decoded bits are then sent to the JPEG2000 decoder. The positions of bits belonging to error-free coding passes are then fed back to the channel decoder. The log-likelihood ratios (LLRs of these bits are then modified by a weighting factor for the next iteration. By observing the statistics of the decoding procedure, the weighting factor is designed as a function of the channel condition. Results show that the proposed joint decoding methods can greatly reduce the number of iterations, and thereby reduce the decoding delay considerably. At the same time, this method always outperforms the nonsource controlled decoding method by up to 3 dB in terms of PSNR.

  6. Decoding Area Studies and Interdisciplinary Majors: Building a Framework for Entry-Level Students

    Science.gov (United States)

    MacPherson, Kristina Ruth

    2015-01-01

    Decoding disciplinary expertise for novices is increasingly part of the undergraduate curriculum. But how might area studies and other interdisciplinary programs, which require integration of courses from multiple disciplines, decode expertise in a similar fashion? Additionally, as a part of decoding area studies and interdisciplines, how might a…

  7. Home and School Technology: Wired versus Wireless.

    Science.gov (United States)

    Van Horn, Royal

    2001-01-01

    Presents results of informal research on smart homes and appliances, structured home wiring, whole-house audio/video distribution, hybrid cable, and wireless networks. Computer network wiring is tricky to install unless all-in-one jacketed cable is used. Wireless phones help installers avoid pre-wiring problems in homes and schools. (MLH)

  8. Electrochemistry of surface wired cytochrome c and ...

    Indian Academy of Sciences (India)

    Pyrazine unit in the mixed self-assembly promotes the electron transfer in the redox reaction of surface wired Cyt-c. Cyt-c wired on the mixed self-assembly has been used for the amperometric sensing of superoxide. The enzymatically generated superoxide has been successfully detected using the Cyt-c wired electrode.

  9. 49 CFR 393.28 - Wiring systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Wiring systems. 393.28 Section 393.28 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.28 Wiring systems...

  10. Customised 2G HTS wire for applications

    Science.gov (United States)

    Samoilenkov, S.; Molodyk, A.; Lee, S.; Petrykin, V.; Kalitka, V.; Martynova, I.; Makarevich, A.; Markelov, A.; Moyzykh, M.; Blednov, A.

    2016-02-01

    Reproducibility of superconducting properties and suitability for specific applications by means of customised finish are two important attributes required from commercial 2G HTS wire. This paper reviews the consistent performance of SuperOx production 2G HTS wire and describes two novel customisation options: surround polyimide varnish insulation and composite bulk materials assembled with 2G HTS wires soldered together.

  11. Music models aberrant rule decoding and reward valuation in dementia.

    Science.gov (United States)

    Clark, Camilla N; Golden, Hannah L; McCallion, Oliver; Nicholas, Jennifer M; Cohen, Miriam H; Slattery, Catherine F; Paterson, Ross W; Fletcher, Phillip D; Mummery, Catherine J; Rohrer, Jonathan D; Crutch, Sebastian J; Warren, Jason D

    2017-11-24

    Aberrant rule- and reward-based processes underpin abnormalities of socio-emotional behaviour in major dementias. However, these processes remain poorly characterised. Here we used music to probe rule decoding and reward valuation in patients with frontotemporal dementia syndromes and Alzheimer's disease relative to healthy age-matched individuals. We created short melodies that were either harmonically resolved ('finished') or unresolved ('unfinished'); the task was to classify each melody as finished or unfinished (rule processing) and rate its subjective pleasantness (reward valuation). Results were adjusted for elementary pitch and executive processing; neuroanatomical correlates were assessed using voxel-based morphometry. Relative to healthy older controls, patients with behavioural variant frontotemporal dementia showed impairments of both musical rule decoding and reward valuation, while patients with semantic dementia showed impaired reward valuation but intact rule decoding, patients with Alzheimer's disease showed impaired rule decoding but intact reward valuation and patients with progressive nonfluent aphasia performed comparably to healthy controls. Grey matter associations with task performance were identified in anterior temporal, medial and lateral orbitofrontal cortices, previously implicated in computing diverse biological and non-biological rules and rewards. The processing of musical rules and reward distils cognitive and neuroanatomical mechanisms relevant to complex socio-emotional dysfunction in major dementias. © The Author (2017). Published by Oxford University Press.

  12. Transfer of decoding skills in early foreign language reading

    NARCIS (Netherlands)

    Ven, M.A.M. van de; Voeten, M.J.M.; Steenbeek-Planting, E.G.; Verhoeven, L.T.W.

    2018-01-01

    This longitudinal study investigated cross-linguistic transfer from native to foreign language decoding abilities in 787 Dutch first-year students in two differential tracks (high vs low) of secondary education. On two occasions, with a six months interval, we tested the students' word and

  13. Name that tune: Decoding music from the listening brain

    NARCIS (Netherlands)

    Schaefer, R.S.; Farquhar, J.D.R.; Blokland, Y.M.; Sadakata, M.; Desain, P.W.M.

    2011-01-01

    In the current study we use electroencephalography (EEG) to detect heard music from the brain signal, hypothesizing that the time structure in music makes it especially suitable for decoding perception from EEG signals. While excluding music with vocals, we classified the perception of seven

  14. Name that tune: decoding music from the listening brain.

    NARCIS (Netherlands)

    Schaefer, R.S.; Farquhar, J.D.R.; Blokland, Y.M.; Sadakata, M.; Desain, P.W.M.

    2011-01-01

    In the current study we use electroencephalography (EEG) to detect heard music from the brain signal, hypothesizing that the time structure in music makes it especially suitable for decoding perception from EEG signals. While excluding music with vocals, we classified the perception of seven

  15. Using Sound/Symbol Frequencies to Teach Decoding Skills.

    Science.gov (United States)

    Alexander, David S.; And Others

    1979-01-01

    The phonics method of teaching decoding skills appeals to adult readers because of its logical application of real and apparent phoneme/symbol correspondences. Instead of memorization, a low level cognitive skill, adults are challenged to use perceptions of the correspondences gained inductively. (Author/CSS)

  16. Real Time Decoding of Color Symbol for Optical Positioning System

    Directory of Open Access Journals (Sweden)

    Abdul Waheed Malik

    2015-01-01

    Full Text Available This paper presents the design and real-time decoding of a color symbol that can be used as a reference marker for optical navigation. The designed symbol has a circular shape and is printed on paper using two distinct colors. This pair of colors is selected based on the highest achievable signal to noise ratio. The symbol is designed to carry eight bit information. Real time decoding of this symbol is performed using a heterogeneous combination of Field Programmable Gate Array (FPGA and a microcontroller. An image sensor having a resolution of 1600 by 1200 pixels is used to capture images of symbols in complex backgrounds. Dynamic image segmentation, component labeling and feature extraction was performed on the FPGA. The region of interest was further computed from the extracted features. Feature data belonging to the symbol was sent from the FPGA to the microcontroller. Image processing tasks are partitioned between the FPGA and microcontroller based on data intensity. Experiments were performed to verify the rotational independence of the symbols. The maximum distance between camera and symbol allowing for correct detection and decoding was analyzed. Experiments were also performed to analyze the number of generated image components and sub-pixel precision versus different light sources and intensities. The proposed hardware architecture can process up to 55 frames per second for accurate detection and decoding of symbols at two Megapixels resolution. The power consumption of the complete system is 342mw.

  17. Decoding Reed–Solomon Codes Using Euclid's Algorithm

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 4. Decoding Reed–Solomon Codes Using Euclid's Algorithm. Priti Shankar. General Article Volume 12 ... Author Affiliations. Priti Shankar1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India.

  18. Decoding by dynamic chunking for statistical machine translation

    NARCIS (Netherlands)

    Yahyaei, S.; Monz, C.; Gerber, L.; Isabelle, P.; Kuhn, R.; Bemish, N.; Dillinger, M.; Goulet, M.-J.

    2009-01-01

    In this paper we present an extension of a phrase-based decoder that dynamically chunks, reorders, and applies phrase translations in tandem. A maximum entropy classifier is trained based on the word alignments to find the best positions to chunk the source sentence. No language specific or

  19. Adaptive Combined Source and Channel Decoding with Modulation ...

    African Journals Online (AJOL)

    In this paper, an adaptive system employing combined source and channel decoding with modulation is proposed for slow Rayleigh fading channels. Huffman code is used as the source code and Convolutional code is used for error control. The adaptive scheme employs a family of Convolutional codes of different rates ...

  20. Decoding sound level in the marmoset primary auditory cortex.

    Science.gov (United States)

    Sun, Wensheng; Marongelli, Ellisha N; Watkins, Paul V; Barbour, Dennis L

    2017-10-01

    Neurons that respond favorably to a particular sound level have been observed throughout the central auditory system, becoming steadily more common at higher processing areas. One theory about the role of these level-tuned or nonmonotonic neurons is the level-invariant encoding of sounds. To investigate this theory, we simulated various subpopulations of neurons by drawing from real primary auditory cortex (A1) neuron responses and surveyed their performance in forming different sound level representations. Pure nonmonotonic subpopulations did not provide the best level-invariant decoding; instead, mixtures of monotonic and nonmonotonic neurons provided the most accurate decoding. For level-fidelity decoding, the inclusion of nonmonotonic neurons slightly improved or did not change decoding accuracy until they constituted a high proportion. These results indicate that nonmonotonic neurons fill an encoding role complementary to, rather than alternate to, monotonic neurons.NEW & NOTEWORTHY Neurons with nonmonotonic rate-level functions are unique to the central auditory system. These level-tuned neurons have been proposed to account for invariant sound perception across sound levels. Through systematic simulations based on real neuron responses, this study shows that neuron populations perform sound encoding optimally when containing both monotonic and nonmonotonic neurons. The results indicate that instead of working independently, nonmonotonic neurons complement the function of monotonic neurons in different sound-encoding contexts. Copyright © 2017 the American Physiological Society.

  1. Tracking Perceptual and Memory Decisions by Decoding Brain Activity

    NARCIS (Netherlands)

    van Vugt, Marieke; Brandt, Armin; Schulze-Bonhage, Andreas

    2017-01-01

    Decision making is thought to involve a process of evidence accumulation, modelled as a drifting diffusion process. This modeling framework suggests that all single-stage decisions involve a similar evidence accumulation process. In this paper we use decoding by machine learning classifiers on

  2. Gradient Descent Bit Flipping Algorithms for Decoding LDPC Codes

    OpenAIRE

    Wadayama, Tadashi; Nakamura, Keisuke; Yagita, Masayuki; Funahashi, Yuuki; Usami, Shogo; Takumi, Ichi

    2007-01-01

    A novel class of bit-flipping (BF) algorithms for decoding low-density parity-check (LDPC) codes is presented. The proposed algorithms, which are called gradient descent bit flipping (GDBF) algorithms, can be regarded as simplified gradient descent algorithms. Based on gradient descent formulation, the proposed algorithms are naturally derived from a simple non-linear objective function.

  3. Polar Coding with CRC-Aided List Decoding

    Science.gov (United States)

    2015-08-01

    correction performance of polar codes is poor compared to turbo and low-density parity check ( LDPC ) codes. 3.1 CRC-AIDED LIST DECODING Tal and Vardy [5...found that a slight change could yield even better results, outperforming the LDPC code used in the WiMax standard. They ran simulations of list

  4. Peeling Decoding of LDPC Codes with Applications in Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Weijun Zeng

    2016-01-01

    Full Text Available We present a new approach for the analysis of iterative peeling decoding recovery algorithms in the context of Low-Density Parity-Check (LDPC codes and compressed sensing. The iterative recovery algorithm is particularly interesting for its low measurement cost and low computational complexity. The asymptotic analysis can track the evolution of the fraction of unrecovered signal elements in each iteration, which is similar to the well-known density evolution analysis in the context of LDPC decoding algorithm. Our analysis shows that there exists a threshold on the density factor; if under this threshold, the recovery algorithm is successful; otherwise it will fail. Simulation results are also provided for verifying the agreement between the proposed asymptotic analysis and recovery algorithm. Compared with existing works of peeling decoding algorithm, focusing on the failure probability of the recovery algorithm, our proposed approach gives accurate evolution of performance with different parameters of measurement matrices and is easy to implement. We also show that the peeling decoding algorithm performs better than other schemes based on LDPC codes.

  5. Decoding English Alphabet Letters Using EEG Phase Information

    Science.gov (United States)

    Wang, YiYan; Wang, Pingxiao; Yu, Yuguo

    2018-01-01

    Increasing evidence indicates that the phase pattern and power of the low frequency oscillations of brain electroencephalograms (EEG) contain significant information during the human cognition of sensory signals such as auditory and visual stimuli. Here, we investigate whether and how the letters of the alphabet can be directly decoded from EEG phase and power data. In addition, we investigate how different band oscillations contribute to the classification and determine the critical time periods. An English letter recognition task was assigned, and statistical analyses were conducted to decode the EEG signal corresponding to each letter visualized on a computer screen. We applied support vector machine (SVM) with gradient descent method to learn the potential features for classification. It was observed that the EEG phase signals have a higher decoding accuracy than the oscillation power information. Low-frequency theta and alpha oscillations have phase information with higher accuracy than do other bands. The decoding performance was best when the analysis period began from 180 to 380 ms after stimulus presentation, especially in the lateral occipital and posterior temporal scalp regions (PO7 and PO8). These results may provide a new approach for brain-computer interface techniques (BCI) and may deepen our understanding of EEG oscillations in cognition. PMID:29467615

  6. An adaptive low-power LDPC decoder using SNR estimation

    Directory of Open Access Journals (Sweden)

    Park Joo-Yul

    2011-01-01

    Full Text Available Abstract Owing to advancement in 4 G mobile communication and mobile TV, the throughput requirement in digital communication has been increasing rapidly. Thus, the need for efficient error-correcting codes is increasing. Furthermore, since most mobile devices operate with limited battery power, low-power communication techniques are attracting considerable attention lately. In this article, we propose a novel low-power, low-density parity check (LDPC decoder. The LDPC code is one of the most common error-correcting codes. In mobile TV, SNR estimation is required for the adaptive coding and modulation technique. We apply the SNR estimation result to the proposed LDPC decoding to minimize power consumption due to unnecessary operations. The SNR estimation value is used for predicting the iteration count until the completion of the successful LDPC decoding. When the SNR value is low, we omit computing the parity check and the tentative decision. We implemented the proposed decoder which is capable of adaptively skipping unnecessary operations based on the SNR estimation. The power consumption was measured to show the efficiency of our approach. We verified that, by using our proposed method, power consumption is reduced by 10% for the SNR range of 1.5-2.5 dB.

  7. A syntactified direct translation model with linear-time decoding

    NARCIS (Netherlands)

    Hassan, H.; Sima'an, K.; Way, A.

    2009-01-01

    Recent syntactic extensions of statistical translation models work with a synchronous context-free or tree-substitution grammar extracted from an automatically parsed parallel corpus. The decoders accompanying these extensions typically exceed quadratic time complexity. This paper extends the Direct

  8. Emittance growth due to Tevatron flying wires

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M; Eddy, Nathan

    2004-06-01

    During Tevatron injection, Flying Wires have been used to measure the transverse beam size after each transfer from the Main Injector in order to deduce the transverse emittances of the proton and antiproton beams. This amounts to 36 + 9 = 45 flies of each of 3 wire systems, with an individual wire passing through each beam bunch twice during a single ''fly''. below they estimate the emittance growth induced by the interaction of the wires with the particles during these measurements. Changes of emittance from Flying Wire measurements conducted during three recent stores are compared with the estimations.

  9. On Lattice Sequential Decoding for Large MIMO Systems

    KAUST Repository

    Ali, Konpal S.

    2014-04-01

    Due to their ability to provide high data rates, Multiple-Input Multiple-Output (MIMO) wireless communication systems have become increasingly popular. Decoding of these systems with acceptable error performance is computationally very demanding. In the case of large overdetermined MIMO systems, we employ the Sequential Decoder using the Fano Algorithm. A parameter called the bias is varied to attain different performance-complexity trade-offs. Low values of the bias result in excellent performance but at the expense of high complexity and vice versa for higher bias values. We attempt to bound the error by bounding the bias, using the minimum distance of a lattice. Also, a particular trend is observed with increasing SNR: a region of low complexity and high error, followed by a region of high complexity and error falling, and finally a region of low complexity and low error. For lower bias values, the stages of the trend are incurred at lower SNR than for higher bias values. This has the important implication that a low enough bias value, at low to moderate SNR, can result in low error and low complexity even for large MIMO systems. Our work is compared against Lattice Reduction (LR) aided Linear Decoders (LDs). Another impressive observation for low bias values that satisfy the error bound is that the Sequential Decoder\\'s error is seen to fall with increasing system size, while it grows for the LR-aided LDs. For the case of large underdetermined MIMO systems, Sequential Decoding with two preprocessing schemes is proposed – 1) Minimum Mean Square Error Generalized Decision Feedback Equalization (MMSE-GDFE) preprocessing 2) MMSE-GDFE preprocessing, followed by Lattice Reduction and Greedy Ordering. Our work is compared against previous work which employs Sphere Decoding preprocessed using MMSE-GDFE, Lattice Reduction and Greedy Ordering. For the case of large systems, this results in high complexity and difficulty in choosing the sphere radius. Our schemes

  10. Sums of Spike Waveform Features for Motor Decoding

    Directory of Open Access Journals (Sweden)

    Jie Li

    2017-07-01

    Full Text Available Traditionally, the key step before decoding motor intentions from cortical recordings is spike sorting, the process of identifying which neuron was responsible for an action potential. Recently, researchers have started investigating approaches to decoding which omit the spike sorting step, by directly using information about action potentials' waveform shapes in the decoder, though this approach is not yet widespread. Particularly, one recent approach involves computing the moments of waveform features and using these moment values as inputs to decoders. This computationally inexpensive approach was shown to be comparable in accuracy to traditional spike sorting. In this study, we use offline data recorded from two Rhesus monkeys to further validate this approach. We also modify this approach by using sums of exponentiated features of spikes, rather than moments. Our results show that using waveform feature sums facilitates significantly higher hand movement reconstruction accuracy than using waveform feature moments, though the magnitudes of differences are small. We find that using the sums of one simple feature, the spike amplitude, allows better offline decoding accuracy than traditional spike sorting by expert (correlation of 0.767, 0.785 vs. 0.744, 0.738, respectively, for two monkeys, average 16% reduction in mean-squared-error, as well as unsorted threshold crossings (0.746, 0.776; average 9% reduction in mean-squared-error. Our results suggest that the sums-of-features framework has potential as an alternative to both spike sorting and using unsorted threshold crossings, if developed further. Also, we present data comparing sorted vs. unsorted spike counts in terms of offline decoding accuracy. Traditional sorted spike counts do not include waveforms that do not match any template (“hash”, but threshold crossing counts do include this hash. On our data and in previous work, hash contributes to decoding accuracy. Thus, using the

  11. Sums of Spike Waveform Features for Motor Decoding.

    Science.gov (United States)

    Li, Jie; Li, Zheng

    2017-01-01

    Traditionally, the key step before decoding motor intentions from cortical recordings is spike sorting, the process of identifying which neuron was responsible for an action potential. Recently, researchers have started investigating approaches to decoding which omit the spike sorting step, by directly using information about action potentials' waveform shapes in the decoder, though this approach is not yet widespread. Particularly, one recent approach involves computing the moments of waveform features and using these moment values as inputs to decoders. This computationally inexpensive approach was shown to be comparable in accuracy to traditional spike sorting. In this study, we use offline data recorded from two Rhesus monkeys to further validate this approach. We also modify this approach by using sums of exponentiated features of spikes, rather than moments. Our results show that using waveform feature sums facilitates significantly higher hand movement reconstruction accuracy than using waveform feature moments, though the magnitudes of differences are small. We find that using the sums of one simple feature, the spike amplitude, allows better offline decoding accuracy than traditional spike sorting by expert (correlation of 0.767, 0.785 vs. 0.744, 0.738, respectively, for two monkeys, average 16% reduction in mean-squared-error), as well as unsorted threshold crossings (0.746, 0.776; average 9% reduction in mean-squared-error). Our results suggest that the sums-of-features framework has potential as an alternative to both spike sorting and using unsorted threshold crossings, if developed further. Also, we present data comparing sorted vs. unsorted spike counts in terms of offline decoding accuracy. Traditional sorted spike counts do not include waveforms that do not match any template ("hash"), but threshold crossing counts do include this hash. On our data and in previous work, hash contributes to decoding accuracy. Thus, using the comparison between

  12. LDPC-based iterative joint source-channel decoding for JPEG2000.

    Science.gov (United States)

    Pu, Lingling; Wu, Zhenyu; Bilgin, Ali; Marcellin, Michael W; Vasic, Bane

    2007-02-01

    A framework is proposed for iterative joint source-channel decoding of JPEG2000 codestreams. At the encoder, JPEG2000 is used to perform source coding with certain error-resilience (ER) modes, and LDPC codes are used to perform channel coding. During decoding, the source decoder uses the ER modes to identify corrupt sections of the codestream and provides this information to the channel decoder. Decoding is carried out jointly in an iterative fashion. Experimental results indicate that the proposed method requires fewer iterations and improves overall system performance.

  13. Functional-Decode-Forward for the General Discrete Memoryless Two-Way Relay Channel

    CERN Document Server

    Ong, Lawrence; Johnson, Sarah J; 10.1109/ICCS.2010.5686490

    2011-01-01

    We consider the general discrete memoryless two-way relay channel, where two users exchange messages via a relay, and propose two functional-decode-forward coding strategies for this channel. Functional-decode-forward involves the relay decoding a function of the users' messages rather than the individual messages themselves. This function is then broadcast back to the users, which can be used in conjunction with the user's own message to decode the other user's message. Via a numerical example, we show that functional-decode-forward with linear codes is capable of achieving strictly larger sum rates than those achievable by other strategies.

  14. Plasma formation in metallic wire Z pinches

    Science.gov (United States)

    Chittenden; Lebedev; Ruiz-Camacho; Beg; Bland; Jennings; Bell; Haines; Pikuz; Shelkovenko; Hammer

    2000-04-01

    Plasma formation in metallic wire Z pinches is modeled using a two-dimensional resistive magnetohydrodynamics code. Modified Thomas-Fermi equations of state and dense plasma transport coefficients allow the phase transitions from solid to plasma to be approximated. Results indicate the persistence of a two-component structure with a cold, dense core embedded within a much hotter, low density, m=0 unstable corona. Extensive benchmark testing against data from a number of single-wire experiments is presented. Artificial laser schlieren and x-ray back-lighting images generated from the code data are compared directly to experimental results. The results were found to be insensitive to inaccuracies in the equations of state and transport coefficients. Simulations of individual wires in a wire array show different behavior to that observed experimentally due to the absence of three-dimensional effects. Simulations with similar conditions to wires in an array show a general trend in the plasma structure at start of implosion from discrete wires with large m=0 perturbation amplitudes to partially merged wires with smaller perturbation amplitudes as the number of wires is increased. Results for a wire number scan with aluminum wire arrays on the SATURN generator suggest that the observed sharp transition to high x-ray power at around 40 wires corresponds to a sharp decrease in m=0 perturbation amplitude and hence a sharp decrease in the seed perturbation for the Rayleigh-Taylor instability.

  15. Slice of LHC dipole wiring

    CERN Multimedia

    Dipole model slice made in 1994 by Ansaldo. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. 50’000 tonnes of steel sheets are used to make the magnet yokes that keep the wiring firmly in place. The yokes constitute approximately 80% of the accelerator's weight and, placed side by side, stretch over 20 km!

  16. Sintered wire cesium dispenser photocathode

    Science.gov (United States)

    Montgomery, Eric J; Ives, R. Lawrence; Falce, Louis R

    2014-03-04

    A photoelectric cathode has a work function lowering material such as cesium placed into an enclosure which couples a thermal energy from a heater to the work function lowering material. The enclosure directs the work function lowering material in vapor form through a low diffusion layer, through a free space layer, and through a uniform porosity layer, one side of which also forms a photoelectric cathode surface. The low diffusion layer may be formed from sintered powdered metal, such as tungsten, and the uniform porosity layer may be formed from wires which are sintered together to form pores between the wires which are continuous from the a back surface to a front surface which is also the photoelectric surface.

  17. Volitional and Real-Time Control Cursor Based on Eye Movement Decoding Using a Linear Decoding Model

    Directory of Open Access Journals (Sweden)

    Jinhua Zhang

    2016-01-01

    Full Text Available The aim of this study is to build a linear decoding model that reveals the relationship between the movement information and the EOG (electrooculogram data to online control a cursor continuously with blinks and eye pursuit movements. First of all, a blink detection method is proposed to reject a voluntary single eye blink or double-blink information from EOG. Then, a linear decoding model of time series is developed to predict the position of gaze, and the model parameters are calibrated by the RLS (Recursive Least Square algorithm; besides, the assessment of decoding accuracy is assessed through cross-validation procedure. Additionally, the subsection processing, increment control, and online calibration are presented to realize the online control. Finally, the technology is applied to the volitional and online control of a cursor to hit the multiple predefined targets. Experimental results show that the blink detection algorithm performs well with the voluntary blink detection rate over 95%. Through combining the merits of blinks and smooth pursuit movements, the movement information of eyes can be decoded in good conformity with the average Pearson correlation coefficient which is up to 0.9592, and all signal-to-noise ratios are greater than 0. The novel system allows people to successfully and economically control a cursor online with a hit rate of 98%.

  18. Real-time SHVC software decoding with multi-threaded parallel processing

    Science.gov (United States)

    Gudumasu, Srinivas; He, Yuwen; Ye, Yan; He, Yong; Ryu, Eun-Seok; Dong, Jie; Xiu, Xiaoyu

    2014-09-01

    This paper proposes a parallel decoding framework for scalable HEVC (SHVC). Various optimization technologies are implemented on the basis of SHVC reference software SHM-2.0 to achieve real-time decoding speed for the two layer spatial scalability configuration. SHVC decoder complexity is analyzed with profiling information. The decoding process at each layer and the up-sampling process are designed in parallel and scheduled by a high level application task manager. Within each layer, multi-threaded decoding is applied to accelerate the layer decoding speed. Entropy decoding, reconstruction, and in-loop processing are pipeline designed with multiple threads based on groups of coding tree units (CTU). A group of CTUs is treated as a processing unit in each pipeline stage to achieve a better trade-off between parallelism and synchronization. Motion compensation, inverse quantization, and inverse transform modules are further optimized with SSE4 SIMD instructions. Simulations on a desktop with an Intel i7 processor 2600 running at 3.4 GHz show that the parallel SHVC software decoder is able to decode 1080p spatial 2x at up to 60 fps (frames per second) and 1080p spatial 1.5x at up to 50 fps for those bitstreams generated with SHVC common test conditions in the JCT-VC standardization group. The decoding performance at various bitrates with different optimization technologies and different numbers of threads are compared in terms of decoding speed and resource usage, including processor and memory.

  19. Genetic Optimization of Wire Antennas

    Directory of Open Access Journals (Sweden)

    Z. Raida

    1998-09-01

    Full Text Available The presented submission describes how genetic algorithms can be applied to the optimization and design of wire antennas. The proposed optimization method is easily programmable and well understandable on one hand, but relatively slowly converging and depending on the parameters of the genetic algorithms on the other hand. The disadvantages of the method are deeply discussed and their elimination is discussed in the paper.

  20. Low Complexity Approach for High Throughput Belief-Propagation based Decoding of LDPC Codes

    Directory of Open Access Journals (Sweden)

    BOT, A.

    2013-11-01

    Full Text Available The paper proposes a low complexity belief propagation (BP based decoding algorithm for LDPC codes. In spite of the iterative nature of the decoding process, the proposed algorithm provides both reduced complexity and increased BER performances as compared with the classic min-sum (MS algorithm, generally used for hardware implementations. Linear approximations of check-nodes update function are used in order to reduce the complexity of the BP algorithm. Considering this decoding approach, an FPGA based hardware architecture is proposed for implementing the decoding algorithm, aiming to increase the decoder throughput. FPGA technology was chosen for the LDPC decoder implementation, due to its parallel computation and reconfiguration capabilities. The obtained results show improvements regarding decoding throughput and BER performances compared with state-of-the-art approaches.

  1. Decoding the genome with an integrative analysis tool: combinatorial CRM Decoder.

    Science.gov (United States)

    Kang, Keunsoo; Kim, Joomyeong; Chung, Jae Hoon; Lee, Daeyoup

    2011-09-01

    The identification of genome-wide cis-regulatory modules (CRMs) and characterization of their associated epigenetic features are fundamental steps toward the understanding of gene regulatory networks. Although integrative analysis of available genome-wide information can provide new biological insights, the lack of novel methodologies has become a major bottleneck. Here, we present a comprehensive analysis tool called combinatorial CRM decoder (CCD), which utilizes the publicly available information to identify and characterize genome-wide CRMs in a species of interest. CCD first defines a set of the epigenetic features which is significantly associated with a set of known CRMs as a code called 'trace code', and subsequently uses the trace code to pinpoint putative CRMs throughout the genome. Using 61 genome-wide data sets obtained from 17 independent mouse studies, CCD successfully catalogued ∼12 600 CRMs (five distinct classes) including polycomb repressive complex 2 target sites as well as imprinting control regions. Interestingly, we discovered that ∼4% of the identified CRMs belong to at least two different classes named 'multi-functional CRM', suggesting their functional importance for regulating spatiotemporal gene expression. From these examples, we show that CCD can be applied to any potential genome-wide datasets and therefore will shed light on unveiling genome-wide CRMs in various species.

  2. Decoding Information for Grasping from the Macaque Dorsomedial Visual Stream.

    Science.gov (United States)

    Filippini, Matteo; Breveglieri, Rossella; Akhras, M Ali; Bosco, Annalisa; Chinellato, Eris; Fattori, Patrizia

    2017-04-19

    Neurodecoders have been developed by researchers mostly to control neuroprosthetic devices, but also to shed new light on neural functions. In this study, we show that signals representing grip configurations can be reliably decoded from neural data acquired from area V6A of the monkey medial posterior parietal cortex. Two Macaca fascicularis monkeys were trained to perform an instructed-delay reach-to-grasp task in the dark and in the light toward objects of different shapes. Population neural activity was extracted at various time intervals on vision of the objects, the delay before movement, and grasp execution. This activity was used to train and validate a Bayes classifier used for decoding objects and grip types. Recognition rates were well over chance level for all the epochs analyzed in this study. Furthermore, we detected slightly different decoding accuracies, depending on the task's visual condition. Generalization analysis was performed by training and testing the system during different time intervals. This analysis demonstrated that a change of code occurred during the course of the task. Our classifier was able to discriminate grasp types fairly well in advance with respect to grasping onset. This feature might be important when the timing is critical to send signals to external devices before the movement start. Our results suggest that the neural signals from the dorsomedial visual pathway can be a good substrate to feed neural prostheses for prehensile actions.SIGNIFICANCE STATEMENT Recordings of neural activity from nonhuman primate frontal and parietal cortex have led to the development of methods of decoding movement information to restore coordinated arm actions in paralyzed human beings. Our results show that the signals measured from the monkey medial posterior parietal cortex are valid for correctly decoding information relevant for grasping. Together with previous studies on decoding reach trajectories from the medial posterior parietal

  3. "Cut wires grating – single longitudinal wire" planar metastructure to achieve microwave magnetic resonance in a single wire

    Directory of Open Access Journals (Sweden)

    G. Kraftmakher

    2012-09-01

    Full Text Available Here we present metastructures containing cut-wire grating and a single longitudinal cut-wire orthogonal to grating’s wires. Experimental investigations at microwaves show these structures can provide strong magnetic resonant response of a single nonmagnetic cut-wire in dependence on configuration and sizes in the case when metastructures are oriented along the direction of wave propagation and cut-wires of grating are parallel to the electric field of a plane electromagnetic wave. It is suggested a concept of magnetic response based on antiparallel resonant currents excited by magnetic field of surface polaritons in many spatial LC-circuits created from cut-wire pairs of a grating and section of longitudinal cut-wire. Three separately observed resonant effects connected with grating, LC-circuits and with longitudinal cut-wire have been identified applying measurements in waveguides, cutoff waveguides and free space. To tune and mark resonance split cut-wires are loaded with varactor diodes.

  4. A Vibrating Wire System For Quadrupole Fiducialization

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Zachary

    2010-12-13

    A vibrating wire system is being developed to fiducialize the quadrupoles between undulator segments in the LCLS. This note provides a detailed analysis of the system. The LCLS will have quadrupoles between the undulator segments to keep the electron beam focused. If the quadrupoles are not centered on the beam axis, the beam will receive transverse kicks, causing it to deviate from the undulator axis. Beam based alignment will be used to move the quadrupoles onto a straight line, but an initial, conventional alignment must place the quadrupole centers on a straight line to 100 {micro}m. In the fiducialization step of the initial alignment, the position of the center of the quadrupole is measured relative to tooling balls on the outside of the quadrupole. The alignment crews then use the tooling balls to place the magnet in the tunnel. The required error on the location of the quadrupole center relative to the tooling balls must be less than 25 {micro}m. In this note, we analyze a system under construction for the quadrupole fiducialization. The system uses the vibrating wire technique to position a wire onto the quadrupole magnetic axis. The wire position is then related to tooling balls using wire position detectors. The tooling balls on the wire position detectors are finally related to tooling balls on the quadrupole to perform the fiducialization. The total 25 {micro}m fiducialization error must be divided between these three steps. The wire must be positioned onto the quadrupole magnetic axis to within 10 {micro}m, the wire position must be measured relative to tooling balls on the wire position detectors to within 15 {micro}m, and tooling balls on the wire position detectors must be related to tooling balls on the quadrupole to within 10 {micro}m. The techniques used in these three steps will be discussed. The note begins by discussing various quadrupole fiducialization techniques used in the past and discusses why the vibrating wire technique is our method

  5. Phosphorus in antique iron music wire.

    Science.gov (United States)

    Goodway, M

    1987-05-22

    Harpsichords and other wire-strung musical instruments were made with longer strings about the beginning of the 17th century. This change required stronger music wire. Although these changes coincided with the introduction of the first mass-produced steel (iron alloyed with carbon), carbon was not found in samples of antique iron harpsichord wire. The wire contained an amount of phosphorus sufficient to have impeded its conversion to steel, and may have been drawn from iron rejected for this purpose. The method used to select pig iron for wire drawing ensured the highest possible phosphorus content at a time when its presence in iron was unsuspected. Phosphorus as an alloying element has had the reputation for making steel brittle when worked cold. Nevertheless, in replicating the antique wire, it was found that lowcarbon iron that contained 0.16 percent phosphorus was easily drawn to appropriate gauges and strengths for restringing antique harpsichords.

  6. Electromagnetic Behaviour of Metallic Wire Structures

    CERN Document Server

    Chui, S T

    2013-01-01

    Despite the recent development and interest in the photonics of metallic wire structures, the relatively simple concepts and physics often remain obscured or poorly explained to those who do not specialize in the field. Electromagnetic Behaviour of Metallic Wire Structures provides a clear and coherent guide to understanding these phenomena without excessive numerical calculations.   Including both background material and detailed derivations of the various different formulae applied, Electromagnetic Behaviour of Metallic Wire Structures describes how to extend basic circuit theory relating to voltages, currents, and resistances of metallic wire networks to include situations where the currents are no longer spatially uniform along the wire. This lays a foundation for a deeper understanding of the many new phenomena observed in meta-electromagnetic materials.   Examples of applications are included to support this new approach making Electromagnetic Behaviour of Metallic Wire Structures a comprehensive and ...

  7. Substance Dependency's Effect on Reading Decoding and Comprehension: Reading Decoding and Comprehension Levels as Indicators of Brain Dysfunctioning with Ramifications for Traditional Rehabilitation Programming.

    Science.gov (United States)

    Schadler, Debbie E.

    This paper discusses the outcomes of a study that investigated the effects of substance dependency on the reading decoding and comprehension of 497 adolescents (ages 12-18) involved in an inpatient drug and alcohol rehabilitation program. The first part of the study involved the formal assessment of reading decoding and reading comprehension…

  8. Performance-complexity tradeoff in sequential decoding for the unconstrained AWGN channel

    KAUST Repository

    Abediseid, Walid

    2013-06-01

    In this paper, the performance limits and the computational complexity of the lattice sequential decoder are analyzed for the unconstrained additive white Gaussian noise channel. The performance analysis available in the literature for such a channel has been studied only under the use of the minimum Euclidean distance decoder that is commonly referred to as the lattice decoder. Lattice decoders based on solutions to the NP-hard closest vector problem are very complex to implement, and the search for low complexity receivers for the detection of lattice codes is considered a challenging problem. However, the low computational complexity advantage that sequential decoding promises, makes it an alternative solution to the lattice decoder. In this work, we characterize the performance and complexity tradeoff via the error exponent and the decoding complexity, respectively, of such a decoder as a function of the decoding parameter - the bias term. For the above channel, we derive the cut-off volume-to-noise ratio that is required to achieve a good error performance with low decoding complexity. © 2013 IEEE.

  9. Optimizing for generalization in the decoding of internally generated activity in the hippocampus.

    Science.gov (United States)

    van der Meer, Matthijs A A; Carey, Alyssa A; Tanaka, Youki

    2017-05-01

    The decoding of a sensory or motor variable from neural activity benefits from a known ground truth against which decoding performance can be compared. In contrast, the decoding of covert, cognitive neural activity, such as occurs in memory recall or planning, typically cannot be compared to a known ground truth. As a result, it is unclear how decoders of such internally generated activity should be configured in practice. We suggest that if the true code for covert activity is unknown, decoders should be optimized for generalization performance using cross-validation. Using ensemble recording data from hippocampal place cells, we show that this cross-validation approach results in different decoding error, different optimal decoding parameters, and different distributions of error across the decoded variable space. In addition, we show that a minor modification to the commonly used Bayesian decoding procedure, which enables the use of spike density functions, results in substantially lower decoding errors. These results have implications for the interpretation of covert neural activity, and suggest easy-to-implement changes to commonly used procedures across domains, with applications to hippocampal place cells in particular. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  10. Decoding Signal Processing at the Single-Cell Level

    Energy Technology Data Exchange (ETDEWEB)

    Wiley, H. Steven

    2017-12-01

    The ability of cells to detect and decode information about their extracellular environment is critical to generating an appropriate response. In multicellular organisms, cells must decode dozens of signals from their neighbors and extracellular matrix to maintain tissue homeostasis while still responding to environmental stressors. How cells detect and process information from their surroundings through a surprisingly limited number of signal transduction pathways is one of the most important question in biology. Despite many decades of research, many of the fundamental principles that underlie cell signal processing remain obscure. However, in this issue of Cell Systems, Gillies et al present compelling evidence that the early response gene circuit can act as a linear signal integrator, thus providing significant insight into how cells handle fluctuating signals and noise in their environment.

  11. IEE wiring regulations explained and illustrated

    CERN Document Server

    Scaddan, Brian

    2013-01-01

    The IEE Wiring Regulations Explained and Illustrated, Second Edition discusses the recommendations of the IEE Regulations for the Electrical Equipment of Buildings for the safe selection or erection of wiring installations. The book emphasizes earthing, bonding, protection, and circuit design of electrical wirings. The text reviews the fundamental requirements for safety, earthing systems, the earth fault loop impedance, and supplementary bonding. The book also describes the different types of protection, such as protection against mechanical damage, overcurrent, under voltage (which prevents

  12. Radiofrequency Wire Recanalization of Chronically Thrombosed TIPS

    Energy Technology Data Exchange (ETDEWEB)

    Majdalany, Bill S., E-mail: bmajdala@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States); Elliott, Eric D., E-mail: eric.elliott@osumc.edu [The Ohio State University Wexner Medical Center, Division of Interventional Radiology, Department of Radiology (United States); Michaels, Anthony J., E-mail: Anthony.michaels@osumc.edu; Hanje, A. James, E-mail: James.Hanje@osumc.edu [The Ohio State University Wexner Medical Center, Division of Gastroenterology and Hepatology, Department of Medicine (United States); Saad, Wael E. A., E-mail: wsaad@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States)

    2016-07-15

    Radiofrequency (RF) guide wires have been applied to cardiac interventions, recanalization of central venous thromboses, and to cross biliary occlusions. Herein, the use of a RF wire technique to revise chronically occluded transjugular intrahepatic portosystemic shunts (TIPS) is described. In both cases, conventional TIPS revision techniques failed to revise the chronically thrombosed TIPS. RF wire recanalization was successfully performed through each of the chronically thrombosed TIPS, demonstrating initial safety and feasibility in this application.

  13. NEW DIRECTIONS IN THE ROLLED WIRE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    A. V. Vedeneev

    2004-01-01

    Full Text Available Analysis of the world practice and comparison with the competitors data shows, that for keeping up of RUP “BMZ'' competitiveness it is necessary to carry out works in directions of perfection of the steel wire cord production technology, development of steel wire cord, development of the breaker constructions with the high infiltration of rubber of wire with superstandard diameter and etc.

  14. Experimental setup to detect superconducting wire motion

    OpenAIRE

    K. Ruwali; A. Yamanaka; Y. Teramoto; K. Nakanishi; K. Hosoyama

    2009-01-01

    An experimental setup was designed and fabricated to study superconducting wire motion under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as the tension to the superconducting wire and different insulating materials at the interface of the superconducting wire and head part. The insulating materials used in the experiments were polyimide film and a high strength polyethylene fiber cloth, Dyneema. Details of the experim...

  15. Minimisation of the wire position uncertainties of the new CERN vacuum wire scanner

    CERN Document Server

    AUTHOR|(CDS)2069346; Barjau Condomines, A

    In the next years the luminosity of the LHC will be significantly increased. This will require a much higher accuracy of beam profile measurement than actually achievable by the current wire scanner. The new fast wire scanner is foreseen to measure small emittance beams throughout the LHC injector chain, which demands a wire travelling speed up to 20 ms-1 and position measurement accuracy of the order of a few microns. The vibrations of the mechanical parts of the system, and particularly the vibrations of the thin carbon wire, were identified as the major error sources of wire position uncertainty. Therefore the understanding of the wire vibrations is a high priority for the design and operation of the new device. This document presents the work performed to understand the main causes of the wire vibrations observed in one of the existing wire scanner and the new proposed design.

  16. List decoding of a class of affine variety codes

    CERN Document Server

    Geil, Olav

    2011-01-01

    Consider a polynomial $F$ in $m$ variables and a finite point ensemble $S=S_1 \\times ... \\times S_m$. When given the leading monomial of $F$ with respect to a lexicographic ordering we derive improved information on the possible number of zeros of $F$ of multiplicity at least $r$ from $S$. We then use this information to design a list decoding algorithm for a large class of affine variety codes.

  17. Maximum likelihood convolutional decoding (MCD) performance due to system losses

    Science.gov (United States)

    Webster, L.

    1976-01-01

    A model for predicting the computational performance of a maximum likelihood convolutional decoder (MCD) operating in a noisy carrier reference environment is described. This model is used to develop a subroutine that will be utilized by the Telemetry Analysis Program to compute the MCD bit error rate. When this computational model is averaged over noisy reference phase errors using a high-rate interpolation scheme, the results are found to agree quite favorably with experimental measurements.

  18. Iterative source channel decoding : design and optimization for heterogeneous networks

    OpenAIRE

    Schmalen, Laurent

    2011-01-01

    The source-channel separation theorem postulated by Shannon has influenced the design of communication systems for multimedia content over the last decades: Source encoding and channel encoding are performed as two separate steps. However, the conditions of the separation theorem are almost never fulfilled in practical systems; a joint consideration of source and channel coding can thus be of special interest. Such a joint consideration with iterative decoding based on the Turbo principle has...

  19. Hierarchical multi-resolution mesh networks for brain decoding.

    Science.gov (United States)

    Onal Ertugrul, Itir; Ozay, Mete; Yarman Vural, Fatos T

    2017-10-04

    Human brain is supposed to process information in multiple frequency bands. Therefore, we can extract diverse information from functional Magnetic Resonance Imaging (fMRI) data by processing it at multiple resolutions. We propose a framework, called Hierarchical Multi-resolution Mesh Networks (HMMNs), which establishes a set of brain networks at multiple resolutions of fMRI signal to represent the underlying cognitive process. Our framework, first, decomposes the fMRI signal into various frequency subbands using wavelet transform. Then, a brain network is formed at each subband by ensembling a set of local meshes. Arc weights of each local mesh are estimated by ridge regression. Finally, adjacency matrices of mesh networks obtained at different subbands are used to train classifiers in an ensemble learning architecture, called fuzzy stacked generalization (FSG). Our decoding performances on Human Connectome Project task-fMRI dataset reflect that HMMNs can successfully discriminate tasks with 99% accuracy, across 808 subjects. Diversity of information embedded in mesh networks of multiple subbands enables the ensemble of classifiers to collaborate with each other for brain decoding. The suggested HMMNs decode the cognitive tasks better than a single classifier applied to any subband. Also mesh networks have a better representation power compared to pairwise correlations or average voxel time series. Moreover, fusion of diverse information using FSG outperforms fusion with majority voting. We conclude that, fMRI data, recorded during a cognitive task, provide diverse information in multi-resolution mesh networks. Our framework fuses this complementary information and boosts the brain decoding performances obtained at individual subbands.

  20. Design of LOG-MAP / MAX-LOG-MAP Decoder

    Directory of Open Access Journals (Sweden)

    Mihai TIMIS, PhD Candidate, Dipl.Eng.

    2007-01-01

    Full Text Available The process of turbo-code decoding starts with the formation of a posteriori probabilities (APPs for each data bit, which is followed by choosing the data-bit value that corresponds to the maximum a posteriori (MAP probability for that data bit. Upon reception of a corrupted code-bit sequence, the process of decision making with APPs allows the MAP algorithm to determine the most likely information bit to have been transmitted at each bit time.

  1. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose:The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...

  2. submitter Dynamical Models of a Wire Scanner

    CERN Document Server

    Barjau, Ana; Dehning, Bernd

    2016-01-01

    The accuracy of the beam profile measurements achievable by the current wire scanners at CERN is limited by the vibrations of their mechanical parts. In particular, the vibrations of the carbon wire represent the major source of wire position uncertainty which limits the beam profile measurement accuracy. In the coming years, due to the Large Hadron Collider (LHC) luminosity upgrade, a wire traveling speed up to 20 $m s^{−1}$ and a position measurement accuracy of the order of 1 μm will be required. A new wire scanner design based on the understanding of the wire vibration origin is therefore needed. We present the models developed to understand the main causes of the wire vibrations observed in an existing wire scanner. The development and tuning of those models are based on measurements and tests performed on that CERN proton synchrotron (PS) scanner. The final model for the (wire + fork) system has six degrees-of-freedom (DOF). The wire equations contain three different excitation terms: inertia...

  3. Encoding and decoding mechanisms of pulsatile hormone secretion.

    Science.gov (United States)

    Walker, J J; Terry, J R; Tsaneva-Atanasova, K; Armstrong, S P; McArdle, C A; Lightman, S L

    2010-12-01

    Ultradian pulsatile hormone secretion underlies the activity of most neuroendocrine systems, including the hypothalamic-pituitary adrenal (HPA) and gonadal (HPG) axes, and this pulsatile mode of signalling permits the encoding of information through both amplitude and frequency modulation. In the HPA axis, glucocorticoid pulse amplitude increases in anticipation of waking, and, in the HPG axis, changing gonadotrophin-releasing hormone pulse frequency is the primary means by which the body alters its reproductive status during development (i.e. puberty). The prevalence of hormone pulsatility raises two crucial questions: how are ultradian pulses encoded (or generated) by these systems, and how are these pulses decoded (or interpreted) at their target sites? We have looked at mechanisms within the HPA axis responsible for encoding the pulsatile mode of glucocorticoid signalling that we observe in vivo. We review evidence regarding the 'hypothalamic pulse generator' hypothesis, and describe an alternative model for pulse generation, which involves steroid feedback-dependent endogenous rhythmic activity throughout the HPA axis. We consider the decoding of hormone pulsatility by taking the HPG axis as a model system and focussing on molecular mechanisms of frequency decoding by pituitary gonadotrophs. © 2010 The Authors. Journal of Neuroendocrinology © 2010 Blackwell Publishing Ltd.

  4. Information loss associated with imperfect observation and mismatched decoding

    Directory of Open Access Journals (Sweden)

    Masafumi eOizumi

    2011-03-01

    Full Text Available We consider two types of causes leading to information loss when neural activities are passed and processed in the brain. One is responses of upstream neurons to stimuli being imperfectly observed by downstream neurons. The other is upstream neurons non-optimally decoding stimuli information contained in the activities of the downstream neurons. To investigate the importance of neural correlation in information processing in the brain, we specifically consider two situations. One is when neural responses are not simultaneously observed, i.e., neural correlation data is lost. This situation means that stimului information is decoded without any specific assumption about neural correlations. The other is when stimuli information is decoded by a wrong statistical model where neural responses are assumed to be independent even when they are not. We provide the information geometric interpretation of these two types of information loss and clarify their relationship. We then concretely evaluate these types of information loss in some simple examples. Finally, we discuss use of these evaluations of information loss to elucidate the importance of correlation in neural information processing.

  5. On the relation between encoding and decoding of neuronal spikes.

    Science.gov (United States)

    Koyama, Shinsuke

    2012-06-01

    Neural coding is a field of study that concerns how sensory information is represented in the brain by networks of neurons. The link between external stimulus and neural response can be studied from two parallel points of view. The first, neural encoding, refers to the mapping from stimulus to response. It focuses primarily on understanding how neurons respond to a wide variety of stimuli and constructing models that accurately describe the stimulus-response relationship. Neural decoding refers to the reverse mapping, from response to stimulus, where the challenge is to reconstruct a stimulus from the spikes it evokes. Since neuronal response is stochastic, a one-to-one mapping of stimuli into neural responses does not exist, causing a mismatch between the two viewpoints of neural coding. Here we use these two perspectives to investigate the question of what rate coding is, in the simple setting of a single stationary stimulus parameter and a single stationary spike train represented by a renewal process. We show that when rate codes are defined in terms of encoding, that is, the stimulus parameter is mapped onto the mean firing rate, the rate decoder given by spike counts or the sample mean does not always efficiently decode the rate codes, but it can improve efficiency in reading certain rate codes when correlations within a spike train are taken into account.

  6. Biological 2-input decoder circuit in human cells.

    Science.gov (United States)

    Guinn, Michael; Bleris, Leonidas

    2014-08-15

    Decoders are combinational circuits that convert information from n inputs to a maximum of 2(n) outputs. This operation is of major importance in computing systems yet it is vastly underexplored in synthetic biology. Here, we present a synthetic gene network architecture that operates as a biological decoder in human cells, converting 2 inputs to 4 outputs. As a proof-of-principle, we use small molecules to emulate the two inputs and fluorescent reporters as the corresponding four outputs. The experiments are performed using transient transfections in human kidney embryonic cells and the characterization by fluorescence microscopy and flow cytometry. We show a clear separation between the ON and OFF mean fluorescent intensity states. Additionally, we adopt the integrated mean fluorescence intensity for the characterization of the circuit and show that this metric is more robust to transfection conditions when compared to the mean fluorescent intensity. To conclude, we present the first implementation of a genetic decoder. This combinational system can be valuable toward engineering higher-order circuits as well as accommodate a multiplexed interface with endogenous cellular functions.

  7. FE modeling of Cu wire bond process and reliability

    NARCIS (Netherlands)

    Yuan, C.A.; Weltevreden, E.R.; Akker, P. van den; Kregting, R.; Vreugd, J. de; Zhang, G.Q.

    2011-01-01

    Copper based wire bonding technology is widely accepted by electronic packaging industry due to the world-wide cost reduction actions (compared to gold wire bond). However, the mechanical characterization of copper wire differs from the gold wire; hence the new wire bond process setting and new bond

  8. THERMO-MECHANICALLY PROCESSED ROLLED WIRE FOR HIGH-STRENGTH ON-BOARD WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    Full Text Available It is shown that at twisting of wire of diameter 1,83 mm, produced by direct wire drawing of thermomechanically processed rolled wire of diameter 5,5 mm of steel 90, metal stratification is completely eliminated at decrease of carbon, manganese and an additional alloying of chrome.

  9. Finite element analysis on the wire breaking rule of 1×7IWS steel wire rope

    Directory of Open Access Journals (Sweden)

    Wenzheng Du

    2017-01-01

    Full Text Available Taking the wire rope of 1×7+IWS structure as the research object, the influences of the number of broken wires on the stress distribution under the same axial load were simulated and analysed, and it also explored the rule of wire breaking of steel wire ropes. Based on the SolidWorks software, the three-dimensional model of the wire rope was established. Importing the model into the ABAQUS, the finite element model of the steel wire rope was established. Firstly 5000 N axial tension was placed on the rope, the stress distribution was simulated and analysed, and the steel wire with the largest stress distribution was found out. Then one steel wire was truncated with the load unchanged, and the finite element simulation was carried out again, and repeated the steps several times. The results show that, with the increase of the number of broken wires, the Von-Mises stress of the wire rope increases sharply, and the stress distribution is concentrated on the rest of the unbroken wires, which brings great challenges to the safety of the wire rope.

  10. The use of intracranial recordings to decode human language: Challenges and opportunities.

    Science.gov (United States)

    Martin, Stephanie; Millán, José Del R; Knight, Robert T; Pasley, Brian N

    2016-07-01

    Decoding speech from intracranial recordings serves two main purposes: understanding the neural correlates of speech processing and decoding speech features for targeting speech neuroprosthetic devices. Intracranial recordings have high spatial and temporal resolution, and thus offer a unique opportunity to investigate and decode the electrophysiological dynamics underlying speech processing. In this review article, we describe current approaches to decoding different features of speech perception and production - such as spectrotemporal, phonetic, phonotactic, semantic, and articulatory components - using intracranial recordings. A specific section is devoted to the decoding of imagined speech, and potential applications to speech prosthetic devices. We outline the challenges in decoding human language, as well as the opportunities in scientific and neuroengineering applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. The Eulerian buckling test for orthodontic wires.

    Science.gov (United States)

    De Santis, R; Dolci, F; Laino, A; Martina, R; Ambrosio, L; Nicolais, L

    2008-04-01

    Orthodontic treatment is mainly dependent on the loads developed by metal wires. The load developed by a buckled orthodontic wire is of great concern for molar distalization and cannot be simply derived from mechanical properties measured through classical tests (i.e. tensile, torsion, and bending). A novel testing method, based on the Eulerian approach of a simple supported beam, has been developed in order to measure the load due to buckling of orthodontic wires. Elastic titanium molybdenum alloy (TMA; SDS Ormco) and superelastic Nitinol (3M Unitek) and copper nickel-titanium (NiTi; SDS Ormco) wires, each having a rectangular cross section of 0.016 x 0.022 square inches (0.41 x 0.56 mm(2)), were used. The wires were activated and deactivated by loading and unloading. In order to analyse thermo-mechanical properties in buckling, mechanical tests were assisted by calorimetric measurements through differential scanning calorimetry (DSC). Statistical analysis to determine differences between the samples was undertaken using two-way analysis of variance (ANOVA) and Tukey's post hoc test, and one-way ANOVA to assess differences between the tested wires under similar conditions and different materials. The results suggest that the load due to buckling depends on material composition, wire length, the amount of activation, temperature, and deformation rate. The results can be considered as the lower bound for the loads experienced by teeth as far as a buckled wire is concerned. At a temperature higher than the austenite finish transition temperature, superelastic wires were strongly dependent on temperature and deformation rate. The effect due to an increase of deformation rate was similar to that of a decrease of temperature. Load variations due to temperature of a superelastic wire with a length of 20 mm were estimated to be approximately 4 g/degrees C. The high performance of an applied superelastic wire may be related to the high dynamics of the load in relation to

  12. An Efficient Partial Sums Generator for Constituent Code based Successive Cancellation Decoding of Polar Codes

    OpenAIRE

    Che, Tiben; Choi, Gwan

    2016-01-01

    This paper proposes the architecture of partial sum generator for constituent codes based polar code decoder. Constituent codes based polar code decoder has the advantage of low latency. However, no purposefully designed partial sum generator design exists that can yield desired timing for the decoder. We first derive the mathematical presentation with the partial sums set $\\bm{\\beta^c}$ which is corresponding to each constituent codes. From this, we concoct a shift-register based partial sum...

  13. Using Exit Charts to Develop an Early Stopping Criterion for Turbo Decoding

    OpenAIRE

    Potman, J.; Hoeksema, F.W.; Slump, Cornelis H.

    2004-01-01

    Early stopping criteria are used to determine when additional decoder iterations result in little or no improvement in the bit- error-rate (BER) at the output of a Turbo decoder. This paper proposes a stopping criterion based on Extrinsic Information Transfer (EXIT) charts. The generation and properties of EXIT charts are discussed. Convergence and BER predictions obtained using EXIT charts are compared to results obtained using Turbo decoder simulation. Finally this paper describes the use o...

  14. Biased Random Key Genetic Algorithm with Hybrid Decoding for Multi-objective Optimization

    OpenAIRE

    Tangpattanakul, Panwadee; Jozefowiez, Nicolas; Lopez, Pierre

    2013-01-01

    International audience; A biased random key genetic algorithm (BRKGA) is an efficient method for solving combinatorial optimization problems. It can be applied to solve both single-objective and multi-objective optimization problems. The BRKGA operates on a chromosome encoded as a key vector of real values between [0,1]. Generally, the chromosome has to be decoded by using a single decoding method in order to obtain a feasible solution. This paper presents a hybrid decoding, which combines th...

  15. Modelling reading development through phonological decoding and self-teaching: implications for dyslexia

    OpenAIRE

    Ziegler, J C; Perry, C; Zorzi, M

    2014-01-01

    The most influential theory of learning to read is based on the idea that children rely on phonological decoding skills to learn novel words. According to the self-teaching hypothesis, each successful decoding encounter with an unfamiliar word provides an opportunity to acquire word-specific orthographic information that is the foundation of skilled word recognition. Therefore, phonological decoding acts as a self-teaching mechanism or ‘built-in teacher’. However, all previous connectionist m...

  16. Wire grid and wire scanner design for the CERN Linac4

    CERN Document Server

    Roncarolo, F; Cheymol, B; Dutriat, C; Duraffourg, M; Focker, G J; Raich, U; Vuitton, C

    2010-01-01

    As part of the CERN LHC injector chain upgrade, LINAC4 [1] will accelerate H- ions from 45 KeV to 160 MeV. A number of wire grids and wire scanners will be used to characterize the beam transverse profile. This paper covers all monitor design aspects intended to cope with the required specifications. In particular, the overall measurement robustness, accuracy and sensitivity must be satisfied for different commissioning and operational scenarios. The physics mechanisms generating the wire signals and the wire resistance to beam induced thermal loads have been considered in order to determine the most appropriate monitor design in terms of wire material and dimensions.

  17. Steer-by-wire innovations and demonstrator

    NARCIS (Netherlands)

    Lupker, H.A.; Zuurbier, J.; Verschuren, R.M.A.F.; Jansen, S.T.H.; Willemsen, D.M.C.

    2002-01-01

    Arguments for 'by-wire' systems include production costs, packaging and traffic safety. Innovations concern both product and development process e.g. combined virtual engineering and Hardware-in-the-loop testing. Three Steer-by-wire systems are discussed: a steering system simulator used as a

  18. Add-On Shielding for Unshielded Wire

    Science.gov (United States)

    Koenig, J. C.; Billitti, J. W.; Tallon, J. M.

    1983-01-01

    Fabrication sequence used to produce compact shields slipped into place from free ends of wires already soldered into connectors at other ends. Single shields are formed into harnesses by connecting grounding jumpers. Technique is especially useful for small diameter wire attached to microminiature connectors.

  19. WIRED magazine announces rave awards nominees

    CERN Multimedia

    2002-01-01

    WIRED Magazine has anounced the nominees for its fourth annual WIRED Rave Awards, celebrating innovation and the individuals transforming commerce and culture. Jeffrey Hangst of the University of Aarhus has been nominated in the science category, for his work on the ATHENA Experiment, CERN (1/2 page).

  20. Kirschner Wire Breakage during Removal Requiring Retrieval

    Directory of Open Access Journals (Sweden)

    Kai Yuen Wong

    2016-01-01

    Full Text Available Kirschner wires (K-wires are widely used for fixation of fractures and dislocations in the hand as they are readily available, reliable, and cost-effective. Complication rates of up to 18% have been reported. However, K-wire breakage during removal is rare. We present one such case illustrating a simple technique for retrieval. A 35-year-old male presented with a distal phalanx fracture of his right middle finger. This open fracture was treated with K-wire fixation. Postoperatively, he developed a pin site infection with associated finger swelling. The K-wire broke during removal with the proximal piece completely retained in his middle phalanx. To minimise risk of osteomyelitis, the K-wire was removed with a novel surgical technique. He had full return of hand function. Intraoperative K-wire breakage has a reported rate of 0.1%. In our case, there was no obvious cause of breakage and the patient denied postoperative trauma. On the other hand, pin site infections are much more common with reported rates of up to 7% in the hand or wrist. K-wire fixation is a simple method for bony stabilisation but can be a demanding procedure with complications often overlooked. It is important to be aware of the potential sequelae.

  1. Wire compensation: Performance, SPS MDs, pulsed system

    CERN Document Server

    Dorda, U

    2008-01-01

    A wire compensation (BBLR) scheme has been proposed in order to improve the long range beam-beam performance of the nominal LHC and its phase 1 and phase 2 upgrades[1]. In this paper we present experimental experience of the CERN SPS wires (BBLR) and report on progress with the RF BBLR.

  2. 75 FR 4584 - Wire Decking From China

    Science.gov (United States)

    2010-01-28

    ... and whether shipped as a kit or packaged separately. Wire decking is produced from carbon or alloy..., zinc or nickel coated), coated (e.g., with paint, epoxy, or plastic), or uncoated (``raw''). The wire... before June 28, 2010, but such final comments must not contain new factual information and must otherwise...

  3. VLSI Architectures for Sliding-Window-Based Space-Time Turbo Trellis Code Decoders

    Directory of Open Access Journals (Sweden)

    Georgios Passas

    2012-01-01

    Full Text Available The VLSI implementation of SISO-MAP decoders used for traditional iterative turbo coding has been investigated in the literature. In this paper, a complete architectural model of a space-time turbo code receiver that includes elementary decoders is presented. These architectures are based on newly proposed building blocks such as a recursive add-compare-select-offset (ACSO unit, A-, B-, Γ-, and LLR output calculation modules. Measurements of complexity and decoding delay of several sliding-window-technique-based MAP decoder architectures and a proposed parameter set lead to defining equations and comparison between those architectures.

  4. Convergence Analysis of Turbo Decoding of Serially Concatenated Block Codes and Product Codes

    Directory of Open Access Journals (Sweden)

    Krause Amir

    2005-01-01

    Full Text Available The geometric interpretation of turbo decoding has founded a framework, and provided tools for the analysis of parallel-concatenated codes decoding. In this paper, we extend this analytical basis for the decoding of serially concatenated codes, and focus on serially concatenated product codes (SCPC (i.e., product codes with checks on checks. For this case, at least one of the component (i.e., rows/columns decoders should calculate the extrinsic information not only for the information bits, but also for the check bits. We refer to such a component decoder as a serial decoding module (SDM. We extend the framework accordingly, derive the update equations for a general turbo decoder of SCPC, and the expressions for the main analysis tools: the Jacobian and stability matrices. We explore the stability of the SDM. Specifically, for high SNR, we prove that the maximal eigenvalue of the SDM's stability matrix approaches , where is the minimum Hamming distance of the component code. Hence, for practical codes, the SDM is unstable. Further, we analyze the two turbo decoding schemes, proposed by Benedetto and Pyndiah, by deriving the corresponding update equations and by demonstrating the structure of their stability matrices for the repetition code and an SCPC code with information bits. Simulation results for the Hamming and Golay codes are presented, analyzed, and compared to the theoretical results and to simulations of turbo decoding of parallel concatenation of the same codes.

  5. A new LDPC decoding scheme for PDM-8QAM BICM coherent optical communication system

    Science.gov (United States)

    Liu, Yi; Zhang, Wen-bo; Xi, Li-xia; Tang, Xian-feng; Zhang, Xiao-guang

    2015-11-01

    A new log-likelihood ratio (LLR) message estimation method is proposed for polarization-division multiplexing eight quadrature amplitude modulation (PDM-8QAM) bit-interleaved coded modulation (BICM) optical communication system. The formulation of the posterior probability is theoretically analyzed, and the way to reduce the pre-decoding bit error rate ( BER) of the low density parity check (LDPC) decoder for PDM-8QAM constellations is presented. Simulation results show that it outperforms the traditional scheme, i.e., the new post-decoding BER is decreased down to 50% of that of the traditional post-decoding algorithm.

  6. Analysis of Iterated Hard Decision Decoding of Product Codes with Reed-Solomon Component Codes

    DEFF Research Database (Denmark)

    Justesen, Jørn; Høholdt, Tom

    2007-01-01

    Products of Reed-Solomon codes are important in applications because they offer a combination of large blocks, low decoding complexity, and good performance. A recent result on random graphs can be used to show that with high probability a large number of errors can be corrected by iterating...... minimum distance decoding. We present an analysis related to density evolution which gives the exact asymptotic value of the decoding threshold and also provides a closed form approximation to the distribution of errors in each step of the decoding of finite length codes....

  7. Luminance information decoding on the basis of local field potential signals of pigeon optic tectum neurons.

    Science.gov (United States)

    Wang, Songwei; Liu, Lijun; Wang, Zhizhong; Niu, Xiaoke; Hu, Yuxia; Shi, Li

    2017-11-08

    Important aspects of brain information processing can be understood by examining decoding of visual stimuli from neuronal response signals. In this research, the luminance information is decoded from the local field potential signal in the optic tectum region of the pigeon. We designed a luminance visual stimulus model with transient flicker characteristics, recorded multichannel local field potential (LFP) signals using a microelectrode array, extracted LFP Fourier transform energy and phase features, constructed a multivariate linear inverse filter luminance information decoding algorithm, and evaluated decoding effects using a cross-correlation method. We found that LFP signal phase decoding of luminance information yielded better effects than amplitude decoding of luminance information. In the case of optimal frequency band, channels, delay time, and other parameters, the results of phase and amplitude codecoding could reach 0.94±0.02. Comparing the differences between neuronal spike decoding and LFP decoding, we found that LFP signal phase and amplitude codecoding resulted in luminance closer to that of the actual stimulus and required fewer decoding electrode channels.

  8. Assessing decoding ability: the role of speed and accuracy and a new composite indicator to measure decoding skill in elementary grades.

    Science.gov (United States)

    Morlini, Isabella; Stella, Giacomo; Scorza, Maristella

    2015-01-01

    Tools for assessing decoding skill in students attending elementary grades are of fundamental importance for guaranteeing an early identification of reading disabled students and reducing both the primary negative effects (on learning) and the secondary negative effects (on the development of the personality) of this disability. This article presents results obtained by administering existing standardized tests of reading and a new screening procedure to about 1,500 students in the elementary grades in Italy. It is found that variables measuring speed and accuracy in all administered reading tests are not Gaussian, and therefore the threshold values used for classifying a student as a normal decoder or as an impaired decoder must be estimated on the basis of the empirical distribution of these variables rather than by using the percentiles of the normal distribution. It is also found that the decoding speed and the decoding accuracy can be measured in either a 1-minute procedure or in much longer standardized tests. The screening procedure and the tests administered are found to be equivalent insofar as they carry the same information. Finally, it is found that speed and accuracy act as complementary effects in the measurement of decoding ability. On the basis of this last finding, the study introduces a new composite indicator aimed at determining the student's performance, which combines speed and accuracy in the measurement of decoding ability. © Hammill Institute on Disabilities 2013.

  9. Wire scanners in low energy accelerators

    CERN Document Server

    Elmfors, P; Huhtinen, M; Lindroos, M; Olsfors, J; Raich, U

    1997-01-01

    Fast wire scanners are today considered as part of standard instrumentation in high energy synchrotrons. The extension of their use to synchrotrons working at lower energies, where Coulomb scattering can be important and the transverse beam size is large, introduces new complications considering beam heating of the wire, composition of the secondary particle shower and geometrical consideration in the detection set-up. A major problem in treating these effects is that the creation of secondaries in a thin carbon wire by a energetic primary beam is difficult to describe in an analytical way. We are here presenting new results from a full Monte Carlo simulation of this process yielding information on heat deposited in the wire, particle type and energy spectrum of secondaries and angular dependence as a function of primary beam energy. The results are used to derive limits for the use of wire scanners in low energy accelerators.

  10. Decoding spatial attention with EEG and virtual acoustic space.

    Science.gov (United States)

    Dong, Yue; Raif, Kaan E; Determan, Sarah C; Gai, Yan

    2017-11-01

    Decoding spatial attention based on brain signals has wide applications in brain-computer interface (BCI). Previous BCI systems mostly relied on visual patterns or auditory stimulation (e.g., loudspeakers) to evoke synchronous brain signals. There would be difficulties to cover a large range of spatial locations with such a stimulation protocol. The present study explored the possibility of using virtual acoustic space and a visual-auditory matching paradigm to overcome this issue. The technique has the flexibility of generating sound stimulation from virtually any spatial location. Brain signals of eight human subjects were obtained with a 32-channel Electroencephalogram (EEG). Two amplitude-modulated noise or speech sentences carrying distinct spatial information were presented concurrently. Each sound source was tagged with a unique modulation phase so that the phase of the recorded EEG signals indicated the sound being attended to. The phase-tagged sound was further filtered with head-related transfer functions to create the sense of virtual space. Subjects were required to pay attention to the sound source that best matched the location of a visual target. For all the subjects, the phase of a single sound could be accurately reflected over the majority of electrodes based on EEG responses of 90 s or less. The electrodes providing significant decoding performance on auditory attention were fewer and may require longer EEG responses. The reliability and efficiency of decoding with a single electrode varied with subjects. Overall, the virtual acoustic space protocol has the potential of being used in practical BCI systems. © 2017 Saint Louis University. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  11. An Improved Unscented Kalman Filter Based Decoder for Cortical Brain-Machine Interfaces.

    Science.gov (United States)

    Li, Simin; Li, Jie; Li, Zheng

    2016-01-01

    Brain-machine interfaces (BMIs) seek to connect brains with machines or computers directly, for application in areas such as prosthesis control. For this application, the accuracy of the decoding of movement intentions is crucial. We aim to improve accuracy by designing a better encoding model of primary motor cortical activity during hand movements and combining this with decoder engineering refinements, resulting in a new unscented Kalman filter based decoder, UKF2, which improves upon our previous unscented Kalman filter decoder, UKF1. The new encoding model includes novel acceleration magnitude, position-velocity interaction, and target-cursor-distance features (the decoder does not require target position as input, it is decoded). We add a novel probabilistic velocity threshold to better determine the user's intent to move. We combine these improvements with several other refinements suggested by others in the field. Data from two Rhesus monkeys indicate that the UKF2 generates offline reconstructions of hand movements (mean CC 0.851) significantly more accurately than the UKF1 (0.833) and the popular position-velocity Kalman filter (0.812). The encoding model of the UKF2 could predict the instantaneous firing rate of neurons (mean CC 0.210), given kinematic variables and past spiking, better than the encoding models of these two decoders (UKF1: 0.138, p-v Kalman: 0.098). In closed-loop experiments where each monkey controlled a computer cursor with each decoder in turn, the UKF2 facilitated faster task completion (mean 1.56 s vs. 2.05 s) and higher Fitts's Law bit rate (mean 0.738 bit/s vs. 0.584 bit/s) than the UKF1. These results suggest that the modeling and decoder engineering refinements of the UKF2 improve decoding performance. We believe they can be used to enhance other decoders as well.

  12. Decoding cognitive concepts from neuroimaging data using multivariate pattern analysis.

    Science.gov (United States)

    Alizadeh, Sarah; Jamalabadi, Hamidreza; Schönauer, Monika; Leibold, Christian; Gais, Steffen

    2017-10-01

    Multivariate pattern analysis (MVPA) methods are now widely used in life-science research. They have great potential but their complexity also bears unexpected pitfalls. In this paper, we explore the possibilities that arise from the high sensitivity of MVPA for stimulus-related differences, which may confound estimations of class differences during decoding of cognitive concepts. We propose a method that takes advantage of concept-unrelated grouping factors, uses blocked permutation tests, and gradually manipulates the proportion of concept-related information in data while the stimulus-related, concept-irrelevant factors are held constant. This results in a concept-response curve, which shows the relative contribution of these two components, i.e. how much of the decoding performance is specific to higher-order category processing and to lower order stimulus processing. It also allows separating stimulus-related from concept-related neuronal processing, which cannot be achieved experimentally. We applied our method to three different EEG data sets with different levels of stimulus-related confound to decode concepts of digits vs. letters, faces vs. houses, and animals vs. fruits based on event-related potentials at the single trial level. We show that exemplar-specific differences between stimuli can drive classification accuracy to above chance levels even in the absence of conceptual information. By looking into time-resolved windows of brain activity, concept-response curves can help characterize the time-course of lower-level and higher-level neural information processing and detect the corresponding temporal and spatial signatures of the corresponding cognitive processes. In particular, our results show that perceptual information is decoded earlier in time than conceptual information specific to processing digits and letters. In addition, compared to the stimulus-level predictive sites, concept-related topographies are spread more widely and, at later time

  13. An LDPC decoder architecture for wireless sensor network applications.

    Science.gov (United States)

    Biroli, Andrea Dario Giancarlo; Martina, Maurizio; Masera, Guido

    2012-01-01

    The pervasive use of wireless sensors in a growing spectrum of human activities reinforces the need for devices with low energy dissipation. In this work, coded communication between a couple of wireless sensor devices is considered as a method to reduce the dissipated energy per transmitted bit with respect to uncoded communication. Different Low Density Parity Check (LDPC) codes are considered to this purpose and post layout results are shown for a low-area low-energy decoder, which offers percentage energy savings with respect to the uncoded solution in the range of 40%-80%, depending on considered environment, distance and bit error rate.

  14. Construction and decoding of a class of algebraic geometry codes

    DEFF Research Database (Denmark)

    Justesen, Jørn; Larsen, Knud J.; Jensen, Helge Elbrønd

    1989-01-01

    A class of codes derived from algebraic plane curves is constructed. The concepts and results from algebraic geometry that were used are explained in detail; no further knowledge of algebraic geometry is needed. Parameters, generator and parity-check matrices are given. The main result is a decod......A class of codes derived from algebraic plane curves is constructed. The concepts and results from algebraic geometry that were used are explained in detail; no further knowledge of algebraic geometry is needed. Parameters, generator and parity-check matrices are given. The main result...

  15. Wire pad chamber for LHCb muon system

    CERN Document Server

    Botchine, B; Lazarev, V A; Sagidova, N; Vorobev, A P; Vorobyov, A; Vorobyov, Alexei

    2000-01-01

    2000-003 Wire pad chambers (WPC) have been proposed for the outer Region 4 of the LHCb Muon System. These are double gap MWPCs with small wire spacing allowing to obtain 99% detection efficiency in a 20 ns time window. The chambers have a rectangular shape with the vertical dimension from 20 cm in Station 1 to 30 cm in Station 5. The horizontal dimensions will be different with the maximal size of 3 meters in Station 5. The wires are in the vertical direction. The short wire length allows to use small wire spacing needed for high time resolution. Also, this helps to obtain the uniform gas gain over the whole chamber area. The WPC has one row of the wire pads formed by grouping wires in separate readout channels. Four WPC prototypes have been built at PNPI and tested in the PS beam at CERN. Here we report on the results from these tests. Also, the results of simulation of the WPC performance are presented.

  16. In-Situ Wire Damage Detection System

    Science.gov (United States)

    Williams, Martha; Roberson, Luke; Tate, Lanetra; Smith, Trent; Gibson, Tracy; Medelius, Pedro; Jolley, Scott

    2012-01-01

    An In-Situ Wire Damage Detection System (ISWDDS) has been developed that is capable of detecting damage to a wire insulation, or a wire conductor, or to both. The system will allow for realtime, continuous monitoring of wiring health/integrity and reduce the number of false negatives and false positives while being smaller, lighter in weight, and more robust than current systems. The technology allows for improved safety and significant reduction in maintenance hours for aircraft, space vehicles, satellites, and other critical high-performance wiring systems for industries such as energy production and mining. The integrated ISWDDS is comprised of two main components: (1) a wire with an innermost core conductor, an inner insulation film, a conductive layer or inherently conductive polymer (ICP) covering the inner insulation film, an outermost insulation jacket; and (2) smart connectors and electronics capable of producing and detecting electronic signals, and a central processing unit (CPU) for data collection and analysis. The wire is constructed by applying the inner insulation films to the conductor, followed by the outer insulation jacket. The conductive layer or ICP is on the outer surface of the inner insulation film. One or more wires are connected to the CPU using the smart connectors, and up to 64 wires can be monitored in real-time. The ISWDDS uses time domain reflectometry for damage detection. A fast-risetime pulse is injected into either the core conductor or conductive layer and referenced against the other conductor, producing transmission line behavior. If either conductor is damaged, then the signal is reflected. By knowing the speed of propagation of the pulse, and the time it takes to reflect, one can calculate the distance to and location of the damage.

  17. Experimental setup to detect superconducting wire motion

    Science.gov (United States)

    Ruwali, K.; Yamanaka, A.; Teramoto, Y.; Nakanishi, K.; Hosoyama, K.

    2009-04-01

    An experimental setup was designed and fabricated to study superconducting wire motion under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as the tension to the superconducting wire and different insulating materials at the interface of the superconducting wire and head part. The insulating materials used in the experiments were polyimide film and a high strength polyethylene fiber cloth, Dyneema. Details of the experimental setup and the test results are reported in this paper.

  18. Lasing from a single quantum wire

    OpenAIRE

    Hayamizu, Yuhei; Yoshita, Masahiro; Watanabe, Shinichi; Akiyama, Hidefumi; Pfeiffer, Loren N.; West, Ken W.

    2002-01-01

    A laser with an active volume consisting of only a single quantum wire in the 1-dimensional (1-D) ground state is demonstrated. The single wire is formed quantum-mechanically at the T-intersection of a 14 nm Al_{0.07}Ga_{0.93}As quantum well and a 6 nm GaAs quantum well, and is embedded in a 1-D single-mode optical waveguide. We observe single-mode lasing from the quantum wire ground state by optical pumping. The laser operates from 5 to 60 K, and has a low threshold pumping power of 5 mW at ...

  19. Experimental setup to detect superconducting wire motion

    Directory of Open Access Journals (Sweden)

    K. Ruwali

    2009-04-01

    Full Text Available An experimental setup was designed and fabricated to study superconducting wire motion under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as the tension to the superconducting wire and different insulating materials at the interface of the superconducting wire and head part. The insulating materials used in the experiments were polyimide film and a high strength polyethylene fiber cloth, Dyneema. Details of the experimental setup and the test results are reported in this paper.

  20. Applying the Decoding the Disciplines Process to Teaching Structural Mechanics: An Autoethnographic Case Study

    Science.gov (United States)

    Tingerthal, John Steven

    2013-01-01

    Using case study methodology and autoethnographic methods, this study examines a process of curricular development known as "Decoding the Disciplines" (Decoding) by documenting the experience of its application in a construction engineering mechanics course. Motivated by the call to integrate what is known about teaching and learning…

  1. The Contribution of Attentional Control and Working Memory to Reading Comprehension and Decoding

    Science.gov (United States)

    Arrington, C. Nikki; Kulesz, Paulina A.; Francis, David J.; Fletcher, Jack M.; Barnes, Marcia A.

    2014-01-01

    Little is known about how specific components of working memory, namely, attentional processes including response inhibition, sustained attention, and cognitive inhibition, are related to reading decoding and comprehension. The current study evaluated the relations of reading comprehension, decoding, working memory, and attentional control in…

  2. Does Knowing What a Word Means Influence How Easily Its Decoding Is Learned?

    Science.gov (United States)

    Michaud, Mélissa; Dion, Eric; Barrette, Anne; Dupéré, Véronique; Toste, Jessica

    2017-01-01

    Theoretical models of word recognition suggest that knowing what a word means makes it easier to learn how to decode it. We tested this hypothesis with at-risk young students, a group that often responds poorly to conventional decoding instruction in which word meaning is not addressed systematically. A total of 53 first graders received explicit…

  3. Using Exit Charts to Develop an Early Stopping Criterion for Turbo Decoding

    NARCIS (Netherlands)

    Potman, J.; Hoeksema, F.W.; Slump, Cornelis H.

    2004-01-01

    Early stopping criteria are used to determine when additional decoder iterations result in little or no improvement in the bit- error-rate (BER) at the output of a Turbo decoder. This paper proposes a stopping criterion based on Extrinsic Information Transfer (EXIT) charts. The generation and

  4. Children's Decoding of Emotion in Expressive Body Movement: The Development of Cue Attunement.

    Science.gov (United States)

    Boone, R. Thomas; Cunningham, Joseph G.

    1998-01-01

    Examined children's and adults' ability to decode emotions in dance forms of expressive body movements and detect intensity differences in anger and happiness. Found that decoding ability exceeded chance for sadness by 4-year olds; sadness, fear, and happiness by 5-year olds; and all emotions by 8-year olds and adults. Children as young as 5…

  5. Multi-Trial Guruswami–Sudan Decoding for Generalised Reed–Solomon Codes

    DEFF Research Database (Denmark)

    Nielsen, Johan Sebastian Rosenkilde; Zeh, Alexander

    2013-01-01

    An iterated refinement procedure for the Guruswami–Sudan list decoding algorithm for Generalised Reed–Solomon codes based on Alekhnovich’s module minimisation is proposed. The method is parametrisable and allows variants of the usual list decoding approach. In particular, finding the list...

  6. Predicting Reading Comprehension in Early Elementary School: The Independent Contributions of Oral Language and Decoding Skills

    Science.gov (United States)

    Kendeou, Panayiota; van den Broek, Paul; White, Mary Jane; Lynch, Julie S.

    2009-01-01

    The authors examined the development of oral language and decoding skills from preschool to early elementary school and their relation to beginning reading comprehension using a cross-sequential design. Four- and 6-year-old children were tested on oral language and decoding skills and were retested 2 years later. In all age groups, oral language…

  7. Early Word Decoding Ability as a Longitudinal Predictor of Academic Performance

    Science.gov (United States)

    Nordström, Thomas; Jacobson, Christer; Söderberg, Pernilla

    2016-01-01

    This study, using a longitudinal design with a Swedish cohort of young readers, investigates if children's early word decoding ability in second grade can predict later academic performance. In an effort to estimate the unique effect of early word decoding (grade 2) with academic performance (grade 9), gender and non-verbal cognitive ability were…

  8. A Study on Decoding Models for the Reconstruction of Hand Trajectories from the Human Magnetoencephalography

    Directory of Open Access Journals (Sweden)

    Hong Gi Yeom

    2014-01-01

    Full Text Available Decoding neural signals into control outputs has been a key to the development of brain-computer interfaces (BCIs. While many studies have identified neural correlates of kinematics or applied advanced machine learning algorithms to improve decoding performance, relatively less attention has been paid to optimal design of decoding models. For generating continuous movements from neural activity, design of decoding models should address how to incorporate movement dynamics into models and how to select a model given specific BCI objectives. Considering nonlinear and independent speed characteristics, we propose a hybrid Kalman filter to decode the hand direction and speed independently. We also investigate changes in performance of different decoding models (the linear and Kalman filters when they predict reaching movements only or predict both reach and rest. Our offline study on human magnetoencephalography (MEG during point-to-point arm movements shows that the performance of the linear filter or the Kalman filter is affected by including resting states for training and predicting movements. However, the hybrid Kalman filter consistently outperforms others regardless of movement states. The results demonstrate that better design of decoding models is achieved by incorporating movement dynamics into modeling or selecting a model according to decoding objectives.

  9. Word-Decoding Skill Interacts with Working Memory Capacity to Influence Inference Generation during Reading

    Science.gov (United States)

    Hamilton, Stephen; Freed, Erin; Long, Debra L.

    2016-01-01

    The aim of this study was to examine predictions derived from a proposal about the relation between word-decoding skill and working memory capacity, called verbal efficiency theory. The theory states that poor word representations and slow decoding processes consume resources in working memory that would otherwise be used to execute high-level…

  10. Modelling the Implicit Learning of Phonological Decoding from Training on Whole-Word Spellings and Pronunciations

    Science.gov (United States)

    Pritchard, Stephen C.; Coltheart, Max; Marinus, Eva; Castles, Anne

    2016-01-01

    Phonological decoding is central to learning to read, and deficits in its acquisition have been linked to reading disorders such as dyslexia. Understanding how this skill is acquired is therefore important for characterising reading difficulties. Decoding can be taught explicitly, or implicitly learned during instruction on whole word spellings…

  11. Decoding Ability in French as a Foreign Language and Language Learning Motivation

    Science.gov (United States)

    Erler, Lynn; Macaro, Ernesto

    2011-01-01

    This study examined the relationships between decoding ability (the ability to relate graphemes to phonemes) in French as a foreign language, self-reported use of such decoding, and dimensions of motivation, specifically self-efficacy and attribution, among young-beginner learners in England. It investigated whether these factors were related to a…

  12. Fast N-Gram Language Model Look-Ahead for Decoders With Static Pronunciation Prefix Trees

    NARCIS (Netherlands)

    Huijbregts, M.A.H.; Ordelman, Roeland J.F.; de Jong, Franciska M.G.

    2008-01-01

    Decoders that make use of token-passing restrict their search space by various types of token pruning. With use of the Language Model Look-Ahead (LMLA) technique it is possible to increase the number of tokens that can be pruned without loss of decoding precision. Unfortunately, for token passing

  13. Reconfigurable Forward Error Correction Decoder for Beyond 100 Gbps High Speed Optical Links

    DEFF Research Database (Denmark)

    Li, Bomin; Larsen, Knud J.; Zibar, Darko

    2015-01-01

    In this paper we propose a reconfigurable forward error correction decoder for beyond 100 Gbps high speed optical links. The decoders for product codes can be configured to support the applications at a rate of a multiple of 100 Gbps, which provides the flexibility and scalability....

  14. Mathematics Is Differentially Related to Reading Comprehension and Word Decoding: Evidence from a Genetically Sensitive Design

    Science.gov (United States)

    Harlaar, Nicole; Kovas, Yulia; Dale, Philip S.; Petrill, Stephen A.; Plomin, Robert

    2012-01-01

    Although evidence suggests that individual differences in reading and mathematics skills are correlated, this relationship has typically only been studied in relation to word decoding or global measures of reading. It is unclear whether mathematics is differentially related to word decoding and reading comprehension. In the current study, the…

  15. Row Reduction Applied to Decoding of Rank Metric and Subspace Codes

    DEFF Research Database (Denmark)

    Puchinger, Sven; Nielsen, Johan Sebastian Rosenkilde; Li, Wenhui

    2017-01-01

    We show that decoding of ℓ-Interleaved Gabidulin codes, as well as list-ℓ decoding of Mahdavifar–Vardy (MV) codes can be performed by row reducing skew polynomial matrices. Inspired by row reduction of F[x] matrices, we develop a general and flexible approach of transforming matrices over skew...

  16. A Parallel Decoding Algorithm for Short Polar Codes Based on Error Checking and Correcting

    Directory of Open Access Journals (Sweden)

    Yingxian Zhang

    2014-01-01

    Full Text Available We propose a parallel decoding algorithm based on error checking and correcting to improve the performance of the short polar codes. In order to enhance the error-correcting capacity of the decoding algorithm, we first derive the error-checking equations generated on the basis of the frozen nodes, and then we introduce the method to check the errors in the input nodes of the decoder by the solutions of these equations. In order to further correct those checked errors, we adopt the method of modifying the probability messages of the error nodes with constant values according to the maximization principle. Due to the existence of multiple solutions of the error-checking equations, we formulate a CRC-aided optimization problem of finding the optimal solution with three different target functions, so as to improve the accuracy of error checking. Besides, in order to increase the throughput of decoding, we use a parallel method based on the decoding tree to calculate probability messages of all the nodes in the decoder. Numerical results show that the proposed decoding algorithm achieves better performance than that of some existing decoding algorithms with the same code length.

  17. An Iterative Decoding Algorithm for Fusion of Multimodal Information

    Science.gov (United States)

    Shivappa, Shankar T.; Rao, Bhaskar D.; Trivedi, Mohan M.

    2007-12-01

    Human activity analysis in an intelligent space is typically based on multimodal informational cues. Use of multiple modalities gives us a lot of advantages. But information fusion from different sources is a problem that has to be addressed. In this paper, we propose an iterative algorithm to fuse information from multimodal sources. We draw inspiration from the theory of turbo codes. We draw an analogy between the redundant parity bits of the constituent codes of a turbo code and the information from different sensors in a multimodal system. A hidden Markov model is used to model the sequence of observations of individual modalities. The decoded state likelihoods from one modality are used as additional information in decoding the states of the other modalities. This procedure is repeated until a certain convergence criterion is met. The resulting iterative algorithm is shown to have lower error rates than the individual models alone. The algorithm is then applied to a real-world problem of speech segmentation using audio and visual cues.

  18. Characterizing multivariate decoding models based on correlated EEG spectral features.

    Science.gov (United States)

    McFarland, Dennis J

    2013-07-01

    Multivariate decoding methods are popular techniques for analysis of neurophysiological data. The present study explored potential interpretative problems with these techniques when predictors are correlated. Data from sensorimotor rhythm-based cursor control experiments was analyzed offline with linear univariate and multivariate models. Features were derived from autoregressive (AR) spectral analysis of varying model order which produced predictors that varied in their degree of correlation (i.e., multicollinearity). The use of multivariate regression models resulted in much better prediction of target position as compared to univariate regression models. However, with lower order AR features interpretation of the spectral patterns of the weights was difficult. This is likely to be due to the high degree of multicollinearity present with lower order AR features. Care should be exercised when interpreting the pattern of weights of multivariate models with correlated predictors. Comparison with univariate statistics is advisable. While multivariate decoding algorithms are very useful for prediction their utility for interpretation may be limited when predictors are correlated. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  19. Iterative Decoding for an Optical CDMA based Laser communication System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Young; Kim, Eun Cheol [Kwangwoon Univ., Seoul (Korea, Republic of); Cha, Jae Sang [Seoul National Univ. of Technology, Seoul (Korea, Republic of)

    2008-11-15

    An optical CDMA(code division multiple access)based Laser communication system has attracted much attention since it requires minimal optical Laser signal processing and it is virtually delay free, while from the theoretical point of view, its performance depends on the auto and cross correlation properties of employed sequences. Various kinds of channel coding schemes for optical CDMA based Laser communication systems have been proposed and analyzed to compensate nonideal channel and receiver conditions in impaired photon channels. In this paper, we propose and analyze an iterative decoding of optical CDMA based Laser communication signals for both shot noise limited and thermal noise limited systems. It is assumed that optical channel is an intensity modulated (IM)channel and direct detection scheme is employed to detect the received optical signal. The performance is evaluated in terms of bit error probability and throughput. It is demonstrated that the BER and throughput performance is substantially improved with interleaver length for a fixed code rate and with alphabet size of PPM (pulse position modulation). Also, the BER and throughput performance is significantly enhanced with the number of iterations for decoding process. The results in this paper can be applied to the optical CDMA based Laser communication network with multiple access applications.

  20. Hardwarearchitektur für einen universellen LDPC Decoder

    Directory of Open Access Journals (Sweden)

    C. Beuschel

    2009-05-01

    Full Text Available Im vorliegenden Beitrag wird eine universelle Decoderarchitektur für einen Low-Density Parity-Check (LDPC Code Decoder vorgestellt. Anders als bei den in der Literatur häufig beschriebenen Architekturen für strukturierte Codes ist die hier vorgestellte Architektur frei programmierbar, so dass jeder beliebige LDPC Code durch eine Änderung der Initialisierung des Speichers für die Prüfmatrix mit derselben Hardware decodiert werden kann. Die größte Herausforderung beim Entwurf von teilparallelen LDPC Decoder Architekturen liegt im konfliktfreien Datenaustausch zwischen mehreren parallelen Speichern und Berechnungseinheiten, wozu ein Mapping und Scheduling Algorithmus benötigt wird. Der hier vorgestellte Algorithmus stützt sich auf Graphentheorie und findet für jeden beliebigen LDPC Code eine für die Architektur optimale Lösung. Damit sind keine Wartezyklen notwendig und die Parallelität der Architektur wird zu jedem Zeitpunkt voll ausgenutzt.

  1. Artificial spatiotemporal touch inputs reveal complementary decoding in neocortical neurons.

    Science.gov (United States)

    Oddo, Calogero M; Mazzoni, Alberto; Spanne, Anton; Enander, Jonas M D; Mogensen, Hannes; Bengtsson, Fredrik; Camboni, Domenico; Micera, Silvestro; Jörntell, Henrik

    2017-04-04

    Investigations of the mechanisms of touch perception and decoding has been hampered by difficulties in achieving invariant patterns of skin sensor activation. To obtain reproducible spatiotemporal patterns of activation of sensory afferents, we used an artificial fingertip equipped with an array of neuromorphic sensors. The artificial fingertip was used to transduce real-world haptic stimuli into spatiotemporal patterns of spikes. These spike patterns were delivered to the skin afferents of the second digit of rats via an array of stimulation electrodes. Combined with low-noise intra- and extracellular recordings from neocortical neurons in vivo, this approach provided a previously inaccessible high resolution analysis of the representation of tactile information in the neocortical neuronal circuitry. The results indicate high information content in individual neurons and reveal multiple novel neuronal tactile coding features such as heterogeneous and complementary spatiotemporal input selectivity also between neighboring neurons. Such neuronal heterogeneity and complementariness can potentially support a very high decoding capacity in a limited population of neurons. Our results also indicate a potential neuroprosthetic approach to communicate with the brain at a very high resolution and provide a potential novel solution for evaluating the degree or state of neurological disease in animal models.

  2. Successful Decoding of Famous Faces in the Fusiform Face Area

    Science.gov (United States)

    Axelrod, Vadim; Yovel, Galit

    2015-01-01

    What are the neural mechanisms of face recognition? It is believed that the network of face-selective areas, which spans the occipital, temporal, and frontal cortices, is important in face recognition. A number of previous studies indeed reported that face identity could be discriminated based on patterns of multivoxel activity in the fusiform face area and the anterior temporal lobe. However, given the difficulty in localizing the face-selective area in the anterior temporal lobe, its role in face recognition is still unknown. Furthermore, previous studies limited their analysis to occipito-temporal regions without testing identity decoding in more anterior face-selective regions, such as the amygdala and prefrontal cortex. In the current high-resolution functional Magnetic Resonance Imaging study, we systematically examined the decoding of the identity of famous faces in the temporo-frontal network of face-selective and adjacent non-face-selective regions. A special focus has been put on the face-area in the anterior temporal lobe, which was reliably localized using an optimized scanning protocol. We found that face-identity could be discriminated above chance level only in the fusiform face area. Our results corroborate the role of the fusiform face area in face recognition. Future studies are needed to further explore the role of the more recently discovered anterior face-selective areas in face recognition. PMID:25714434

  3. Frame Decoder for Consultative Committee for Space Data Systems (CCSDS)

    Science.gov (United States)

    Reyes, Miguel A. De Jesus

    2014-01-01

    GNU Radio is a free and open source development toolkit that provides signal processing to implement software radios. It can be used with low-cost external RF hardware to create software defined radios, or without hardware in a simulation-like environment. GNU Radio applications are primarily written in Python and C++. The Universal Software Radio Peripheral (USRP) is a computer-hosted software radio designed by Ettus Research. The USRP connects to a host computer via high-speed Gigabit Ethernet. Using the open source Universal Hardware Driver (UHD), we can run GNU Radio applications using the USRP. An SDR is a "radio in which some or all physical layer functions are software defined"(IEEE Definition). A radio is any kind of device that wirelessly transmits or receives radio frequency (RF) signals in the radio frequency. An SDR is a radio communication system where components that have been typically implemented in hardware are implemented in software. GNU Radio has a generic packet decoder block that is not optimized for CCSDS frames. Using this generic packet decoder will add bytes to the CCSDS frames and will not permit for bit error correction using Reed-Solomon. The CCSDS frames consist of 256 bytes, including a 32-bit sync marker (0x1ACFFC1D). This frames are generated by the Space Data Processor and GNU Radio will perform the modulation and framing operations, including frame synchronization.

  4. Spatiotemporal multiplexing: color decoding from single-array digital images

    Science.gov (United States)

    Martinez-Uriegas, Eugenio; Crane, Hewitt D.; Peters, John D.

    1997-06-01

    This is an update from our ongoing studies on a biologically inspired, digital color image representation presented here before. It has evolved into a technology named ChromaplexTM, with practical applications for both static (still pictures) and dynamic (digital video and motion pictures) images in three areas: (1) Simplification of processing, storage, compression, and transmission of digital color images. (2) Economical full-color upgrading of black and white (gray scale) image capturing systems. (3) Increase up to 4X of spatial resolution in high-quality digital image capturing systems currently designed for triplane color capture (three separate CCDs or three scans). Sample images of these applications are available on a world wide web site. In this paper we present data showing that spatial blur artifacts are worse when produced by conventional techniques of color interpolation than those produced by Chromaplex decoding. We also show that Chromaplex color decoding of CCD outputs, first demonstrated for CCDs with relatively narrow-band RGB filters, is equally applicable to digital imaging systems having CCDs with broad band subtractive color filters (like cyan, yellow, and magenta), but the often necessary color transformation from subtractive color to RGB brings in different tradeoffs.

  5. Decoding covert shifts of attention induced by ambiguous visuospatial cues

    Directory of Open Access Journals (Sweden)

    Romain eTrachel

    2015-06-01

    Full Text Available Simple and unambiguous visual cues (e.g. an arrow can be used to trigger covert shifts of visual attention away from the center of gaze. The processing of visual stimuli is enhanced at the attended location. Covert shifts of attention modulate the power of cerebral oscillations in the alpha band over parietal and occipital regions. These modulations are sufficiently robust to be decoded on a single trial basis from electro-encephalography (EEG signals. It is often assumed that covert attention shifts are under voluntary control, and also occur in more natural and complex environments, but there is no direct evidence to support this assumption. We address this important issue by using random-dot stimuli to cue one of two opposite locations, where a visual target is presented. We contrast two conditions in which the random-dot motion is either predictive of the target location or contains ambiguous information. Behavioral results show attention shifts in anticipation of the visual target, in both conditions. In addition, these attention shifts involve similar neural sources, and the EEG can be decoded on a single trial basis. These results shed a new light on the behavioral and neural correlates of visuospatial attention, with implications for Brain-Computer Interfaces (BCI based on covert attention shifts.

  6. Artificial spatiotemporal touch inputs reveal complementary decoding in neocortical neurons

    Science.gov (United States)

    Oddo, Calogero M.; Mazzoni, Alberto; Spanne, Anton; Enander, Jonas M. D.; Mogensen, Hannes; Bengtsson, Fredrik; Camboni, Domenico; Micera, Silvestro; Jörntell, Henrik

    2017-01-01

    Investigations of the mechanisms of touch perception and decoding has been hampered by difficulties in achieving invariant patterns of skin sensor activation. To obtain reproducible spatiotemporal patterns of activation of sensory afferents, we used an artificial fingertip equipped with an array of neuromorphic sensors. The artificial fingertip was used to transduce real-world haptic stimuli into spatiotemporal patterns of spikes. These spike patterns were delivered to the skin afferents of the second digit of rats via an array of stimulation electrodes. Combined with low-noise intra- and extracellular recordings from neocortical neurons in vivo, this approach provided a previously inaccessible high resolution analysis of the representation of tactile information in the neocortical neuronal circuitry. The results indicate high information content in individual neurons and reveal multiple novel neuronal tactile coding features such as heterogeneous and complementary spatiotemporal input selectivity also between neighboring neurons. Such neuronal heterogeneity and complementariness can potentially support a very high decoding capacity in a limited population of neurons. Our results also indicate a potential neuroprosthetic approach to communicate with the brain at a very high resolution and provide a potential novel solution for evaluating the degree or state of neurological disease in animal models. PMID:28374841

  7. Chemically etched modulation in wire radius for wire array Z-pinch perturbation studies

    Science.gov (United States)

    Jones, B.; Deeney, C.; McKenney, J. L.; Garrity, J. E.; Lobley, D. K.; Martin, K. L.; Griego, A. E.; Ramacciotti, J. P.; Bland, S. N.; Lebedev, S. V.; Bott, S. C.; Ampleford, D. J.; Palmer, J. B. A.; Rapley, J.; Hall, G.

    2004-11-01

    A technique for manufacturing wires with imposed modulation in radius with axial wavelengths as short as 1 mm is presented. Extruded aluminum 5056 with 15 μm diameter was masked and chemically etched to reduce the radius by ˜20% in selected regions. Characterized by scanning electron microscopy, the modulation in radius is a step function with a ˜10 μm wide conical transition between thick and thin segments, with some pitting in etched regions. Techniques for mounting and aligning these wires in arrays for fast z-pinch experiments will be discussed. Axially mass-modulated wire arrays of this type will allow the study of seeded Rayleigh-Taylor instabilities in z pinches, corona formation, wire initiation with varying current density in the wire core, and correlation of perturbations between adjacent wires. This tool will support magnetohydrodynamics code validation in complex three-dimensional geometries, and perhaps x-ray pulse shaping.

  8. Firing Rate Estimation Using Infinite Mixture Models and Its Application to Neural Decoding.

    Science.gov (United States)

    Shibue, Ryohei; Komaki, Fumiyasu

    2017-08-09

    Neural decoding is a framework for reconstructing external stimuli from spike trains recorded in brains. Kloosterman et al. (2014) proposed a new decoding method using marked point processes. This method does not require spike sorting and thereby improves decoding accuracy dramatically. In this method, they used kernel density estimation to estimate intensity functions of marked point processes. However, using kernel density estimation causes problems. To overcome these problems, we propose a new decoding method using infinite mixture models to estimate intensity. The proposed method improves decoding performance in terms of accuracy and computation speed. We apply the proposed method to simulation and experimental data to verify its performance. Copyright © 2016, Journal of Neurophysiology.

  9. Efficient Dual Domain Decoding of Linear Block Codes Using Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Ahmed Azouaoui

    2012-01-01

    Full Text Available A computationally efficient algorithm for decoding block codes is developed using a genetic algorithm (GA. The proposed algorithm uses the dual code in contrast to the existing genetic decoders in the literature that use the code itself. Hence, this new approach reduces the complexity of decoding the codes of high rates. We simulated our algorithm in various transmission channels. The performance of this algorithm is investigated and compared with competitor decoding algorithms including Maini and Shakeel ones. The results show that the proposed algorithm gives large gains over the Chase-2 decoding algorithm and reach the performance of the OSD-3 for some quadratic residue (QR codes. Further, we define a new crossover operator that exploits the domain specific information and compare it with uniform and two point crossover. The complexity of this algorithm is also discussed and compared to other algorithms.

  10. On the error probability of general tree and trellis codes with applications to sequential decoding

    Science.gov (United States)

    Johannesson, R.

    1973-01-01

    An upper bound on the average error probability for maximum-likelihood decoding of the ensemble of random binary tree codes is derived and shown to be independent of the length of the tree. An upper bound on the average error probability for maximum-likelihood decoding of the ensemble of random L-branch binary trellis codes of rate R = 1/n is derived which separates the effects of the tail length T and the memory length M of the code. It is shown that the bound is independent of the length L of the information sequence. This implication is investigated by computer simulations of sequential decoding utilizing the stack algorithm. These simulations confirm the implication and further suggest an empirical formula for the true undetected decoding error probability with sequential decoding.

  11. Molecular wires, switches and memories

    Science.gov (United States)

    Chen, Jia

    Molecular electronics, an emerging field, makes it possible to build individual molecules capable of performing functions identical or analogous to present- day conductors, switches, or memories. These individual molecules, with a nano-meter scale characteristic length, can be designed and chemically synthesized with specific atoms, geometries and charge distribution. This thesis focuses on the design, and measurements of molecular wires, and related strategically engineered structures-molecular switches and memories. The experimental system relies on a thermodynamically driven self-assembling process to attach molecules onto substrate surfaces without intervention from outside. The following topics will be discussed: directed nanoscale manipulation of self-assembled molecules using scanning tunneling microscope; investigation on through-bond transport of nanoscale symmetric metal/conjugated self- assembled monolayers (SAM)/metal junctions, where non- Ohmic thermionic emission was observed to be the dominant process, with isocyanide-Pd contacts showing the lowest thermionic barrier of 0.22 eV; the first realization of robust and large reversible switching behavior in an electronic device that utilizes molecules containing redox centers as the active component, exhibiting negative differential resistance (NDR) and large on-off peak-to-valley ratio (PVR); observation of erasable storage of higher conductivity states in these redox- center containing molecular devices, and demonstration of a two-terminal electronically programmable and erasable molecular memory cell with long bit retention time.

  12. FPGA-based Implementation of a Streaming Decoder for Shortened Reed-Solomon Codes

    Directory of Open Access Journals (Sweden)

    S. V. Fedorov

    2016-01-01

    Full Text Available The traditional approaches to decoding shortened block codes are the padding of received codeword with zeros or correction of the syndrome polynomial values. Such approaches make stream-oriented decoding of continuous input data stream impossible. The paper offers a new technique for decoding the shortened Reed-Solomon codes. Its hardware implementation allows us to provide stream processing, reduce latency in clock cycles, and decrease a required quantity of hardware resources as compared to decoder implementation with padding of received packet with zeros. A distinctive feature of the proposed technique is that the decoder processes a stream of code words of different lengths without changing their structure and insertion of additional delays and that it is possible to use the modules of existing Reed-Solomon decoders for full codeword length. To enable this, a notion of error locator corrector for shortened code is introduced and a technique of their calculation is offered. Error locator correctors are calculated during the reception of a codeword in parallel to syndrome polynomial calculation. Their values allow us to modify the polynomial values of locators and errors at the output of the key equation solver. The paper considers a shortened code decoder that is implemented on the full code decoder modules based on Berlekamp-Massey algorithm, describes architecture of additional modules and required modifications of the algorithm. It shows the way to save hardware resources by using the multipliers in Berlekemp-Massey key equation solver to correct values. The Altera FPGA-based decoder has been tested in and compared to the Reed-Solomon II decoder IP from Altera.

  13. Magnetoimpedance simulations in wires and tubes

    CERN Document Server

    Munoz, J L; Kurlyandskaya, G V; Garcia-Arribas, A

    2002-01-01

    Numerical computations have been used to study the magnetoimpedance (MI) effect in magnetic wires and microtubes. Two kinds of wires have been investigated. In the first case, a typical amorphous wire with a core-shell structure is simulated, considering the different magnetization curve of each layer, and in the second case, a non-magnetic wire with a thin deposited layer of magnetic material is studied. The results of the simulations agree in both cases with the experimental behavior usually found for these samples. They also allow us to explain such features as MI saturation and the influence of the resistivities of the conductive and magnetic layers in microtubes, that can improve MI-based devices.

  14. Beam Profiling through Wire Chambing Tracking

    CERN Document Server

    Nash, W

    2013-01-01

    This note describes the calibration of the Delay Wire Chambers (DWCs) used during test runs of CALICE’s Tungsten Digital Hadron Calorimeter (W-DHCAL) prototype in CERN’s SPS beam line (10 – 300 GeV).

  15. Wire core reactor for nuclear thermal propulsion

    Science.gov (United States)

    Harty, Richard B.; Brengle, Robert G.

    1993-01-01

    Studies have been performed of a compact high-performance nuclear rocket reactor that incorporates a tungsten alloy wire fuel element. This reactor, termed the wire core reactor, can deliver a specific impulse of 1,000 s using an expander cycle and a nozzle expansion ratio of 500 to 1. The core is constructed of layers of 0.8-mm-dia fueled tungsten wires wound over alternate layers of spacer wires, which forms a rugged annular lattice. Hydrogen flow in the core is annular, flowing from inside to outside. In addition to the concepts compact size and good heat transfer, the core has excellent power-flow matching features and can resist vibration and thermal stresses during star-up and shutdown.

  16. Wire Bonder: Kulicke and Soffa Model 4526

    Data.gov (United States)

    Federal Laboratory Consortium — Description:CORAL Name: Wire BonderNeeds Description.Scientific Opportunities / Applications:Wedge bonderSemi-automatic and manual modesIndependent Z-axis control,...

  17. Highly stretchable wrinkled gold thin film wires

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joshua, E-mail: joshuk7@uci.edu; Park, Sun-Jun; Nguyen, Thao [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Chu, Michael [Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States); Pegan, Jonathan D. [Department of Materials and Manufacturing Technology, University of California, Irvine, California 92697 (United States); Khine, Michelle, E-mail: mkhine@uci.edu [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States)

    2016-02-08

    With the growing prominence of wearable electronic technology, there is a need to improve the mechanical reliability of electronics for more demanding applications. Conductive wires represent a vital component present in all electronics. Unlike traditional planar and rigid electronics, these new wearable electrical components must conform to curvilinear surfaces, stretch with the body, and remain unobtrusive and low profile. In this paper, the piezoresistive response of shrink induced wrinkled gold thin films under strain demonstrates robust conductive performance in excess of 200% strain. Importantly, the wrinkled metallic thin films displayed negligible change in resistance of up to 100% strain. The wrinkled metallic wires exhibited consistent performance after repetitive strain. Importantly, these wrinkled thin films are inexpensive to fabricate and are compatible with roll to roll manufacturing processes. We propose that these wrinkled metal thin film wires are an attractive alternative to conventional wires for wearable applications.

  18. 30 CFR 77.701-3 - Grounding wires; capacity.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding wires; capacity. 77.701-3 Section 77... MINES Grounding § 77.701-3 Grounding wires; capacity. Where grounding wires are used to ground metallic sheaths, armors, conduits, frames, casings, and other metallic enclosures, such grounding wires will be...

  19. 47 CFR 32.2321 - Customer premises wiring.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Customer premises wiring. 32.2321 Section 32... Customer premises wiring. (a) This account shall include all amounts transferred from the former Account 232, Station Connections, inside wiring subclass. (b) Embedded Customer Premises Wiring is that...

  20. Cobalt chromium sublaminar wires for spinal deformity surgery.

    Science.gov (United States)

    Cluck, Michael W; Skaggs, David L

    2006-09-01

    Biomechanical analysis and retrospective chart review. To determine the mechanical properties of cobalt chromium alloy wires and review the clinical application of the wires as sublaminar implants to correct spinal deformity. Sublaminar wires are commonly used as anchors in spinal deformity surgery. In stainless steel instrumentation systems, single strand wires (Luque wires) may be retightened over time to take advantage of stress relaxation while correcting spinal deformity. Because of the mechanical properties of titanium, solid titanium wires are not used as sublaminar wires. Cobalt chromium alloy is a titanium compatible alloy that can be twisted in a similar fashion to stainless steel sublaminar wires. Comparative tensile tests were performed using cobalt chromium alloy wires and Luque stainless steel wires. In addition, 22 consecutive posterior spinal fusions for idiopathic scoliosis were performed using cobalt chromium alloy wires as sublaminar implants. Yield and ultimate tensile loads for the cobalt chromium alloy wires are on average 66% (P cobalt chromium alloy wires were used as sublaminar implants. Mean preoperative lumbar curve was 52 degrees +/- 14 degrees , which corrected to 17 degrees +/- 8 degrees (68% correction, P cobalt chromium alloy wire over steel wire include greater tensile strength and titanium compatibility. Cobalt chromium alloy solid wires may be used as sublaminar implants with titanium spinal instrumentation with excellent clinical results.

  1. Audio wiring guide how to wire the most popular audio and video connectors

    CERN Document Server

    Hechtman, John

    2012-01-01

    Whether you're a pro or an amateur, a musician or into multimedia, you can't afford to guess about audio wiring. The Audio Wiring Guide is a comprehensive, easy-to-use guide that explains exactly what you need to know. No matter the size of your wiring project or installation, this handy tool provides you with the essential information you need and the techniques to use it. Using The Audio Wiring Guide is like having an expert at your side. By following the clear, step-by-step directions, you can do professional-level work at a fraction of the cost.

  2. A Magnetic Sensor with Amorphous Wire

    Directory of Open Access Journals (Sweden)

    Dongfeng He

    2014-06-01

    Full Text Available Using a FeCoSiB amorphous wire and a coil wrapped around it, we have developed a sensitive magnetic sensor. When a 5 mm long amorphous wire with the diameter of 0.1 mm was used, the magnetic field noise spectrum of the sensor was about 30 pT/ÖHz above 30 Hz. To show the sensitivity and the spatial resolution, the magnetic field of a thousand Japanese yen was scanned with the magnetic sensor.

  3. Graphene wire medium: Homogenization and application

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Chigrin, Dmitry N.; Lavrinenko, Andrei

    2012-01-01

    In this contribution we analyze numerically the optical properties of the graphene wire medium, which unit cell consists of a stripe of graphene embedded into dielectric. We propose a simple method for retrieval of the isofrequency contour and effective permittivity tensor. As an example...... of the graphene wire medium application we demonstrate a reconfigurable hyperlens for the terahertz subwavelength imaging capable of resolving two sources with separation λ0/5 in the far-field....

  4. Subwavelength wire array metamaterial microwave cavities

    Science.gov (United States)

    Al-Rubaiee, M.; Alchalaby, A.; Al-Janabi, H.

    2018-01-01

    Wire array metamaterial cavities and waveguides can be achieved by changing the resonance frequency of one or more unit cell surrounding by unit cells don't support the resonance for certain frequency and hence obtain signal confinement only on the defect wires. Changing the resonance frequency of one or more unit cell was done in this work by changing the length of the unit cell. We validate our approach in experiment and simulation with electromagnetic waves in the microwave range.

  5. Electronic Properties of Quantum Wire Networks

    OpenAIRE

    Kuzmenko, Igor

    2005-01-01

    Quantum wire networks (``quantum crossbars'', QCB) represent a 2D grid formed by superimposed crossing arrays of parallel conducting quantum wires, molecular chains or metallic single-wall carbon nanotubes. QCB coupled only by capacitive interaction in the crosses have similar low-energy, long-wave properties characterized as a crossed sliding Luttinger liquid (CSLL) phase. In this Thesis we develop a theory of interacting Bose excitations (plasmons) in QCB. We analyze spectrum of boson field...

  6. Novel use of the "buddy"wire.

    LENUS (Irish Health Repository)

    O'Hare, A

    2008-12-29

    Summary: During interventional procedures the tortuosity of the vasculature hampers catheter stability. The buddy wire may be used to aid and maintain vascular access.We describe a case of acute subarachnoid haemorrhage secondary to dissecting aneurysm of the vertebral artery.We discuss the value of the buddy wire during balloon occlusion of the vertebral artery not as it is typically used, but to actually prevent the balloon repeatedly entering the posterior inferior cerebellar artery during the procedure.

  7. Charge Transport Along Phenylenevinylene Molecular Wires

    OpenAIRE

    Siebbeles, Laurens; Prins, Paulette; Grozema, Ferdinand

    2006-01-01

    Abstract A model to calculate the mobility of charges along molecular wires is presented. The model is based on the tight-binding approximation and combines a quantum mechanical description of the charge with a classical description of the structural degrees of freedom. It is demonstrated that the average mobility of charge carriers along molecular wires can be obtained by time-propagation of states which are initially localised. The model is used to calculate the mobility of charg...

  8. Wiring System Diagnostic Techniques for Legacy Aircraft

    Science.gov (United States)

    2003-02-01

    Reunions des specialistes des techniques de estion du cycle de vie pour vehicules aeriens vieillissants ] To order the complete compilation report, use...Ageing Mechanisms and Control. Specialists’ Meeting on Life Management Techniques for Ageing Air Vehicles [Les mecanismes vieillissants et le controle...be identified. Additionally, wiring failures tend to be intermittent in nature and can take considerable time to isolate. Wire modifications and

  9. Subchannel Analysis of Wire Wrapped SCWR Assembly

    Directory of Open Access Journals (Sweden)

    Jianqiang Shan

    2014-01-01

    Full Text Available Application of wire wrap spacers in SCWR can reduce pressure drop and obtain better mixing capability. As a consequence, the required coolant pumping power is decreased and the coolant temperature profile inside the fuel bundle is flattened which will obviously decrease the peak cladding temperature. The distributed resistance model for wire wrap was developed and implemented in ATHAS subchannel analysis code. The HPLWR wire wrapped assembly was analyzed. The results show that: (1 the assembly with wire wrap can obtain a more uniform coolant temperature profile than the grid spaced assembly, which will result in a lower peak cladding temperature; (2 the pressure drop in a wire wrapped assembly is less than that in a grid spaced assembly, which can reduce the operating power of pump effectively; (3 the wire wrap pitch has significant effect on the flow in the assembly. Smaller Hwire/Drod will result in stronger cross flow a more uniform coolant temperature profile, and also a higher pressure drop.

  10. Induced Voltage in an Open Wire

    Science.gov (United States)

    Morawetz, K.; Gilbert, M.; Trupp, A.

    2017-07-01

    A puzzle arising from Faraday's law has been considered and solved concerning the question which voltage will be induced in an open wire with a time-varying homogeneous magnetic field. In contrast to closed wires where the voltage is determined by the time variance of the magnetic field and the enclosed area, in an open wire we have to integrate the electric field along the wire. It is found that the longitudinal electric field with respect to the wave vector contributes with 1/3 and the transverse field with 2/3 to the induced voltage. In order to find the electric fields the sources of the magnetic fields are necessary to know. The representation of a spatially homogeneous and time-varying magnetic field implies unavoidably a certain symmetry point or symmetry line which depend on the geometry of the source. As a consequence the induced voltage of an open wire is found to be the area covered with respect to this symmetry line or point perpendicular to the magnetic field. This in turn allows to find the symmetry points of a magnetic field source by measuring the voltage of an open wire placed with different angles in the magnetic field. We present exactly solvable models of the Maxwell equations for a symmetry point and for a symmetry line, respectively. The results are applicable to open circuit problems like corrosion and for astrophysical applications.

  11. The technology of testing the safety of steel wire ropes

    Science.gov (United States)

    Zhang, Xiaochun; Hu, Caiwen

    2005-12-01

    To estimate the security of steel wire rope, the broken wire condition, the capability of the rope to bear weight and the state of stress balance of each wire in the steel wire rope were investigated. The wavelet translation method was applied to analyze the signals of magnetic field leakage from the steel wire rope. The result of the time-frequency analysis of the signals can be used to make certain of he position and the amount of the broken wire. Using the static surveillance method as a basis, a dynamic surveillance method was designed to detect the stress balance of the steel wire rope. This technology makes it possible to check the stress condition of each wire on line. It can be concluded that a wavelet translation analysis and the dynamic surveillance technique are effective methods to detect on line and real-time the broken wire and the stress balance of multistrand wire ropes.

  12. 75 FR 60480 - In the Matter of Certain Bulk Welding Wire Containers and Components Thereof and Welding Wire...

    Science.gov (United States)

    2010-09-30

    ... COMMISSION In the Matter of Certain Bulk Welding Wire Containers and Components Thereof and Welding Wire... importation, or the sale within the United States after importation of certain bulk welding wire containers, components thereof, and welding wire by reason of infringement of certain claims of United States Patent Nos...

  13. Use of a tip-edge stage-1 wire to enhance vertical control during straight wire treatment: two case reports.

    Science.gov (United States)

    Taylor, Helen

    2003-02-01

    Vertical control is one of the problems occasionally encountered in Straight wire treatment. Two cases, one with deep overbite and one with anterior open-bite, demonstrate the use of a Tip-Edge stage-1 wire to enhance vertical control in conjunction with Straight wire brackets and superelastic main arch wires.

  14. Joint Carrier-Phase Synchronization and LDPC Decoding

    Science.gov (United States)

    Simon, Marvin; Valles, Esteban

    2009-01-01

    A method has been proposed to increase the degree of synchronization of a radio receiver with the phase of a suppressed carrier signal modulated with a binary- phase-shift-keying (BPSK) or quaternary- phase-shift-keying (QPSK) signal representing a low-density parity-check (LDPC) code. This method is an extended version of the method described in Using LDPC Code Constraints to Aid Recovery of Symbol Timing (NPO-43112), NASA Tech Briefs, Vol. 32, No. 10 (October 2008), page 54. Both methods and the receiver architectures in which they would be implemented belong to a class of timing- recovery methods and corresponding receiver architectures characterized as pilotless in that they do not require transmission and reception of pilot signals. The proposed method calls for the use of what is known in the art as soft decision feedback to remove the modulation from a replica of the incoming signal prior to feeding this replica to a phase-locked loop (PLL) or other carrier-tracking stage in the receiver. Soft decision feedback refers to suitably processed versions of intermediate results of iterative computations involved in the LDPC decoding process. Unlike a related prior method in which hard decision feedback (the final sequence of decoded symbols) is used to remove the modulation, the proposed method does not require estimation of the decoder error probability. In a basic digital implementation of the proposed method, the incoming signal (having carrier phase theta theta (sub c) plus noise would first be converted to inphase (I) and quadrature (Q) baseband signals by mixing it with I and Q signals at the carrier frequency [wc/(2 pi)] generated by a local oscillator. The resulting demodulated signals would be processed through one-symbol-period integrate and- dump filters, the outputs of which would be sampled and held, then multiplied by a soft-decision version of the baseband modulated signal. The resulting I and Q products consist of terms proportional to the cosine

  15. The Analysis of the High Speed Wire Drawing Process of High Carbon Steel Wires Under Hydrodynamic Lubrication Conditions

    Directory of Open Access Journals (Sweden)

    Suliga M.

    2015-04-01

    Full Text Available In this work the analysis of the wire drawing process in hydrodynamic dies has been done. The drawing process of φ5.5 mm wire rod to the final wire of φ1.7 mm was conducted in 12 passes, in drawing speed range of 5-25 m/s. For final wires of φ1.7 mm the investigation of topography of wire surface, the amount of lubricant on the wire surface and the pressure of lubricant in hydrodynamic dies were determined. Additionally, in the work selected mechanical properties of the wires have been estimated.

  16. Decoding repetitive finger movements with brain activity acquired via non-invasive electroencephalography

    Directory of Open Access Journals (Sweden)

    Andrew Young Paek

    2014-03-01

    Full Text Available We investigated how well repetitive finger tapping movements can be decoded from scalp electroencephalography (EEG signals. A linear decoder with memory was used to infer continuous index finger angular velocities from the low-pass filtered fluctuations of the amplitude of a plurality of EEG signals distributed across the scalp. To evaluate the accuracy of the decoder, the Pearson’s correlation coefficient (r between the observed and predicted trajectories was calculated in a 10-fold cross-validation scheme. We also assessed attempts to decode finger kinematics from EEG data that was cleaned with independent component analysis (ICA, EEG data from peripheral sensors, and EEG data from rest periods. A genetic algorithm was used to select combinations of EEG channels that maximized decoding accuracies. Our results (lower quartile r = 0.20, median r = 0.36, upper quartile r = 0.52 show that delta-band EEG signals contain useful information that can be used to infer finger kinematics. Further, the highest decoding accuracies were characterized by highly correlated delta band EEG activity mostly localized to the contralateral central areas of the scalp. Spectral analysis in alpha (8-13Hz and beta (20-30 Hz EEG respectively also showed focused bilateral alpha event related desynchronizations (ERDs over central scalp areas and contralateral beta event related synchronizations (ERSs localized to central scalp areas. Overall, this study demonstrates the feasibility of decoding finger kinematics from scalp EEG signals.

  17. On the Computational Complexity of Sphere Decoder for Lattice Space-Time Coded MIMO Channel

    CERN Document Server

    Abediseid, Walid

    2011-01-01

    The exact complexity analysis of the basic sphere decoder for general space-time codes applied to multi-input multi-output (MIMO) wireless channel is known to be difficult. In this work, we shed the light on the computational complexity of sphere decoding for the quasi-static, LAttice Space-Time (LAST) coded MIMO channel. Specifically, we derive the asymptotic tail distribution of the decoder's computational complexity in the high signal-to-noise ratio (SNR) regime. For the uncoded $M\\times N$ MIMO channel (e.g., V-BLAST), the analysis in [6] revealed that the tail distribution of such a decoder is of a Pareto-type with tail exponent that is equivalent to $N-M+1$. In our analysis, we show that the tail exponent of the sphere decoder's complexity distribution is equivalent to the diversity-multiplexing tradeoff achieved by LAST coding and lattice decoding schemes. This leads to extend the channel's tradeoff to include the decoding complexity. Moreover, we show analytically how minimum-mean square-error decisio...

  18. Decoding Mammalian Ribosome-mRNA States by Translational GTPase Complexes.

    Science.gov (United States)

    Shao, Sichen; Murray, Jason; Brown, Alan; Taunton, Jack; Ramakrishnan, V; Hegde, Ramanujan S

    2016-11-17

    In eukaryotes, accurate protein synthesis relies on a family of translational GTPases that pair with specific decoding factors to decipher the mRNA code on ribosomes. We present structures of the mammalian ribosome engaged with decoding factor⋅GTPase complexes representing intermediates of translation elongation (aminoacyl-tRNA⋅eEF1A), termination (eRF1⋅eRF3), and ribosome rescue (Pelota⋅Hbs1l). Comparative analyses reveal that each decoding factor exploits the plasticity of the ribosomal decoding center to differentially remodel ribosomal proteins and rRNA. This leads to varying degrees of large-scale ribosome movements and implies distinct mechanisms for communicating information from the decoding center to each GTPase. Additional structural snapshots of the translation termination pathway reveal the conformational changes that choreograph the accommodation of decoding factors into the peptidyl transferase center. Our results provide a structural framework for how different states of the mammalian ribosome are selectively recognized by the appropriate decoding factor⋅GTPase complex to ensure translational fidelity. Copyright © 2016 MRC Laboratory of Molecular Biology. Published by Elsevier Inc. All rights reserved.

  19. ESVD: An Integrated Energy Scalable Framework for Low-Power Video Decoding Systems

    Directory of Open Access Journals (Sweden)

    Wen Ji

    2010-01-01

    Full Text Available Video applications using mobile wireless devices are a challenging task due to the limited capacity of batteries. The higher complex functionality of video decoding needs high resource requirements. Thus, power efficient control has become more critical design with devices integrating complex video processing techniques. Previous works on power efficient control in video decoding systems often aim at the low complexity design and not explicitly consider the scalable impact of subfunctions in decoding process, and seldom consider the relationship with the features of compressed video date. This paper is dedicated to developing an energy-scalable video decoding (ESVD strategy for energy-limited mobile terminals. First, ESVE can dynamically adapt the variable energy resources due to the device aware technique. Second, ESVD combines the decoder control with decoded data, through classifying the data into different partition profiles according to its characteristics. Third, it introduces utility theoretical analysis during the resource allocation process, so as to maximize the resource utilization. Finally, it adapts the energy resource as different energy budget and generates the scalable video decoding output under energy-limited systems. Experimental results demonstrate the efficiency of the proposed approach.

  20. The Ising decoder: reading out the activity of large neural ensembles.

    Science.gov (United States)

    Schaub, Michael T; Schultz, Simon R

    2012-02-01

    The Ising model has recently received much attention for the statistical description of neural spike train data. In this paper, we propose and demonstrate its use for building decoders capable of predicting, on a millisecond timescale, the stimulus represented by a pattern of neural activity. After fitting to a training dataset, the Ising decoder can be applied "online" for instantaneous decoding of test data. While such models can be fit exactly using Boltzmann learning, this approach rapidly becomes computationally intractable as neural ensemble size increases. We show that several approaches, including the Thouless-Anderson-Palmer (TAP) mean field approach from statistical physics, and the recently developed Minimum Probability Flow Learning (MPFL) algorithm, can be used for rapid inference of model parameters in large-scale neural ensembles. Use of the Ising model for decoding, unlike other problems such as functional connectivity estimation, requires estimation of the partition function. As this involves summation over all possible responses, this step can be limiting. Mean field approaches avoid this problem by providing an analytical expression for the partition function. We demonstrate these decoding techniques by applying them to simulated neural ensemble responses from a mouse visual cortex model, finding an improvement in decoder performance for a model with heterogeneous as opposed to homogeneous neural tuning and response properties. Our results demonstrate the practicality of using the Ising model to read out, or decode, spatial patterns of activity comprised of many hundreds of neurons.

  1. Low-Complexity Decoding of Block Turbo-Coded System with Antenna Diversity

    Directory of Open Access Journals (Sweden)

    Chen Yanni

    2003-01-01

    Full Text Available The goal of this paper is to reduce the decoding complexity of space-time block turbo-coded system with low performance degradation. Two block turbo-coded systems with antenna diversity are considered. These include the simple serial concatenation of error control code with space-time block code, and the recently proposed transmit antenna diversity scheme using forward error correction techniques. It is shown that the former performs better when compared to the latter in terms of bit error rate (BER under the same spectral efficiency (up to 7 dB at the BER of for quasistatic channel with two transmit and two receive antennas. For the former system, a computationally efficient decoding approach is proposed for the soft decoding of space-time block code. Compared to its original maximum likelihood decoding algorithm, it can reduce the computation by up to 70% without any performance degradation. Additionally, for the considered outer code block turbo code, through reduction of test patterns scanned in the Chase algorithm and the alternative computation of its extrinsic information during iterative decoding, extra 0.3 dB to 0.4 dB coding gain is obtained if compared with previous approaches with negligible hardware overhead. The overall decoding complexity is approximately ten times less than that of the near-optimum block turbo decoder with coding gain loss of 0.5 dB at the BER of over AWGN channel.

  2. Multiscale decoding for reliable brain-machine interface performance over time.

    Science.gov (United States)

    Han-Lin Hsieh; Wong, Yan T; Pesaran, Bijan; Shanechi, Maryam M

    2017-07-01

    Recordings from invasive implants can degrade over time, resulting in a loss of spiking activity for some electrodes. For brain-machine interfaces (BMI), such a signal degradation lowers control performance. Achieving reliable performance over time is critical for BMI clinical viability. One approach to improve BMI longevity is to simultaneously use spikes and other recording modalities such as local field potentials (LFP), which are more robust to signal degradation over time. We have developed a multiscale decoder that can simultaneously model the different statistical profiles of multi-scale spike/LFP activity (discrete spikes vs. continuous LFP). This decoder can also run at multiple time-scales (millisecond for spikes vs. tens of milliseconds for LFP). Here, we validate the multiscale decoder for estimating the movement of 7 major upper-arm joint angles in a non-human primate (NHP) during a 3D reach-to-grasp task. The multiscale decoder uses motor cortical spike/LFP recordings as its input. We show that the multiscale decoder can improve decoding accuracy by adding information from LFP to spikes, while running at the fast millisecond time-scale of the spiking activity. Moreover, this improvement is achieved using relatively few LFP channels, demonstrating the robustness of the approach. These results suggest that using multiscale decoders has the potential to improve the reliability and longevity of BMIs.

  3. Prior Knowledge Improves Decoding of Finger Flexion from Electrocorticographic (ECoG Signals

    Directory of Open Access Journals (Sweden)

    Zuoguan eWang

    2011-11-01

    Full Text Available Brain-computer interfaces (BCIs use brain signals to convey a user's intent. Some BCI approaches begin by decoding kinematic parameters of movements from brain signals, and then proceed to using these signals, in absence of movements, to allow a user to control an output. Recent results have shown that electrocorticographic (ECoG recordings from the surface of the brain in humans can give information about kinematic parameters (eg{} hand velocity or finger flexion. The decoding approaches in these studies usually employed classical classification/regression algorithms that derive a linear mapping between brain signals and outputs. However, they typically only incorporate little prior information about the target movement parameter. In this paper, we incorporate prior knowledge using a Bayesian decoding method, and use it to decode finger flexion from ECoG signals. Specifically, we exploit the anatomic constraints and dynamic constraints that govern finger flexion and incorporate these constraints in the construction, structure, and the probabilistic functions of the prior model of a switched non-parametric dynamic system (SNDS. Given a measurement model resulting from a traditional linear regression method, we decoded finger flexion using posterior estimation that combined the prior and measurement models. Our results show that the application of the Bayesian decoding model, which incorporates prior knowledge, improves decoding performance compared to the application of a linear regression model, which does not incorporate prior knowledge. Thus, the results presented in this paper may ultimately lead to neurally controlled hand prostheses with full fine-grained finger articulation.

  4. Joint Source and Channel Decoding for Variable Length Encoded Turbo Codes

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2007-11-01

    Full Text Available Joint source and channel decoding (JSCD has been proved to be an effective technique which can improve decoding performance by exploiting residual source redundancy. Most previous publications on this subject focus on a traditional coding scheme in which the source variable-length coding (VLC is serially concatenated with a channel code. In this paper, a parallel concatenated coding scheme for the VLC combined with a turbo code is presented. By merging a symbol-level VLC trellis with a convolutional trellis, we construct a symbol-level joint trellis with compound states. Also, a solution of the symbol-by-symbol a posteriori probability (APP decoding algorithm based on this joint trellis is derived, which leads to an iterative JSCD approach in the similar way to the classical turbo decoder. The simulation results show that our joint source-channel en/decoding system achieves some gains at the cost of increasing decoding complexity, when compared to the joint iterative decoding based on the bit-level super trellis for the separate coding system.

  5. Cellular automaton decoders of topological quantum memories in the fault tolerant setting

    Science.gov (United States)

    Herold, Michael; Kastoryano, Michael J.; Campbell, Earl T.; Eisert, Jens

    2017-06-01

    Active error decoding and correction of topological quantum codes—in particular the toric code—remains one of the most viable routes to large scale quantum information processing. In contrast, passive error correction relies on the natural physical dynamics of a system to protect encoded quantum information. However, the search is ongoing for a completely satisfactory passive scheme applicable to locally interacting two-dimensional systems. Here, we investigate dynamical decoders that provide passive error correction by embedding the decoding process into local dynamics. We propose a specific discrete time cellular-automaton decoder in the fault tolerant setting and provide numerical evidence showing that the logical qubit has a survival time extended by several orders of magnitude over that of a bare unencoded qubit. We stress that (asynchronous) dynamical decoding gives rise to a Markovian dissipative process. We hence equate cellular-automaton decoding to a fully dissipative topological quantum memory, which removes errors continuously. In this sense, uncontrolled and unwanted local noise can be corrected for by a controlled local dissipative process. We analyze the required resources, commenting on additional polylogarithmic factors beyond those incurred by an ideal constant resource dynamical decoder.

  6. Low Complexity List Decoding for Polar Codes with Multiple CRC Codes

    Directory of Open Access Journals (Sweden)

    Jong-Hwan Kim

    2017-04-01

    Full Text Available Polar codes are the first family of error correcting codes that provably achieve the capacity of symmetric binary-input discrete memoryless channels with low complexity. Since the development of polar codes, there have been many studies to improve their finite-length performance. As a result, polar codes are now adopted as a channel code for the control channel of 5G new radio of the 3rd generation partnership project. However, the decoder implementation is one of the big practical problems and low complexity decoding has been studied. This paper addresses a low complexity successive cancellation list decoding for polar codes utilizing multiple cyclic redundancy check (CRC codes. While some research uses multiple CRC codes to reduce memory and time complexity, we consider the operational complexity of decoding, and reduce it by optimizing CRC positions in combination with a modified decoding operation. Resultingly, the proposed scheme obtains not only complexity reduction from early stopping of decoding, but also additional reduction from the reduced number of decoding paths.

  7. Exact performance analysis of decode-and-forward opportunistic relaying

    KAUST Repository

    Tourki, Kamel

    2010-06-01

    In this paper, we investigate a dual-hop decode-and-forward opportunistic relaying scheme where the source may or may not be able to communicate directly with the destination. In our study, we consider a regenerative relaying scheme in which the decision to cooperate takes into account the effect of the possible erroneously detected and transmitted data at the best relay. We derive an exact closed-form expression for the end-to-end bit-error rate (BER) of binary phase-shift keying (BPSK) modulation based on the exact statistics of each hop. Unlike existing works where the analysis focused on high signal-to-noise ratio (SNR) regime, such results are important to enable the designers to take decisions regarding practical systems that operate at low SNR regime. We show that performance simulation results coincide with our analytical results.

  8. Generalized instantly decodable network coding for relay-assisted networks

    KAUST Repository

    Elmahdy, Adel M.

    2013-09-01

    In this paper, we investigate the problem of minimizing the frame completion delay for Instantly Decodable Network Coding (IDNC) in relay-assisted wireless multicast networks. We first propose a packet recovery algorithm in the single relay topology which employs generalized IDNC instead of strict IDNC previously proposed in the literature for the same relay-assisted topology. This use of generalized IDNC is supported by showing that it is a super-set of the strict IDNC scheme, and thus can generate coding combinations that are at least as efficient as strict IDNC in reducing the average completion delay. We then extend our study to the multiple relay topology and propose a joint generalized IDNC and relay selection algorithm. This proposed algorithm benefits from the reception diversity of the multiple relays to further reduce the average completion delay in the network. Simulation results show that our proposed solutions achieve much better performance compared to previous solutions in the literature. © 2013 IEEE.

  9. Outage analysis of opportunistic decode-and-forward relaying

    KAUST Repository

    Tourki, Kamel

    2010-09-01

    In this paper, we investigate a dual-hop opportunistic decode-and-forward relaying scheme where the source may or not be able to communicate directly with the destination. We first derive statistics based on exact probability density function (PDF) of each hop. Then, the PDFs are used to determine closed-form outage probability expression for a transmission rate R. Furthermore, we evaluate the asymptotic outage performance and the diversity order is deduced. Unlike existing works where the analysis focused on high signal-to-noise ratio (SNR) regime, such results are important to enable the designers to take decisions regarding practical systems that operate at low SNR regime. We show that performance simulation results coincide with our analytical results under practical assumption of unbalanced hops. © 2010 IEEE.

  10. Fast decoding of codes from algebraic plane curves

    DEFF Research Database (Denmark)

    Justesen, Jørn; Larsen, Knud J.; Jensen, Helge Elbrønd

    1992-01-01

    Improvement to an earlier decoding algorithm for codes from algebraic geometry is presented. For codes from an arbitrary regular plane curve the authors correct up to d*/2-m2 /8+m/4-9/8 errors, where d* is the designed distance of the code and m is the degree of the curve. The complexity of finding...... the error locator is O(n7/3 ), where n is the length of the code. For codes from Hermitian curves the complexity of finding the error values, given the error locator, is O(n2), and the same complexity can be obtained in the general case if only d*/2-m2/2 errors are corrected...

  11. STRS SpaceWire FPGA Module

    Science.gov (United States)

    Lux, James P.; Taylor, Gregory H.; Lang, Minh; Stern, Ryan A.

    2011-01-01

    An FPGA module leverages the previous work from Goddard Space Flight Center (GSFC) relating to NASA s Space Telecommunications Radio System (STRS) project. The STRS SpaceWire FPGA Module is written in the Verilog Register Transfer Level (RTL) language, and it encapsulates an unmodified GSFC core (which is written in VHDL). The module has the necessary inputs/outputs (I/Os) and parameters to integrate seamlessly with the SPARC I/O FPGA Interface module (also developed for the STRS operating environment, OE). Software running on the SPARC processor can access the configuration and status registers within the SpaceWire module. This allows software to control and monitor the SpaceWire functions, but it is also used to give software direct access to what is transmitted and received through the link. SpaceWire data characters can be sent/received through the software interface, as well as through the dedicated interface on the GSFC core. Similarly, SpaceWire time codes can be sent/received through the software interface or through a dedicated interface on the core. This innovation is designed for plug-and-play integration in the STRS OE. The SpaceWire module simplifies the interfaces to the GSFC core, and synchronizes all I/O to a single clock. An interrupt output (with optional masking) identifies time-sensitive events within the module. Test modes were added to allow internal loopback of the SpaceWire link and internal loopback of the client-side data interface.

  12. Forecasting of Corrosion Properties of Steel Wires for Production of Guide Wires for Cardiological Treatment

    National Research Council Canada - National Science Library

    Przondziono, J; Walke, W; Hadasik, E; Młynarski, R

    2013-01-01

    ... of guide wires used in invasive cardiology. The results of static tensile test enabled us to determine the course of flow curve of wires made of X10CrNi 18-8 steel as well as mathematical form of flow stress function...

  13. Modeling and simulation of the fluid flow in wire electrochemical machining with rotating tool (wire ECM)

    Science.gov (United States)

    Klocke, F.; Herrig, T.; Zeis, M.; Klink, A.

    2017-10-01

    Combining the working principle of electrochemical machining (ECM) with a universal rotating tool, like a wire, could manage lots of challenges of the classical ECM sinking process. Such a wire-ECM process could be able to machine flexible and efficient 2.5-dimensional geometries like fir tree slots in turbine discs. Nowadays, established manufacturing technologies for slotting turbine discs are broaching and wire electrical discharge machining (wire EDM). Nevertheless, high requirements on surface integrity of turbine parts need cost intensive process development and - in case of wire-EDM - trim cuts to reduce the heat affected rim zone. Due to the process specific advantages, ECM is an attractive alternative manufacturing technology and is getting more and more relevant for sinking applications within the last few years. But ECM is also opposed with high costs for process development and complex electrolyte flow devices. In the past, few studies dealt with the development of a wire ECM process to meet these challenges. However, previous concepts of wire ECM were only suitable for micro machining applications. Due to insufficient flushing concepts the application of the process for machining macro geometries failed. Therefore, this paper presents the modeling and simulation of a new flushing approach for process assessment. The suitability of a rotating structured wire electrode in combination with an axial flushing for electrodes with high aspect ratios is investigated and discussed.

  14. Decoding the Locus of Covert Visuospatial Attention from EEG Signals

    Science.gov (United States)

    Thiery, Thomas; Lajnef, Tarek; Jerbi, Karim; Arguin, Martin; Aubin, Mercedes; Jolicoeur, Pierre

    2016-01-01

    Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP) components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. In this study, we used a modified Posner cueing task with an endogenous cue to determine the degree to which information in the EEG signal can be used to track visual spatial attention in presentation sequences lasting 200 ms. We used a machine learning classification method to evaluate how well EEG signals discriminate between four different locations of the focus of attention. We then used a multi-class support vector machine (SVM) and a leave-one-out cross-validation framework to evaluate the decoding accuracy (DA). We found that ERP-based features from occipital and parietal regions showed a statistically significant valid prediction of the location of the focus of visuospatial attention (DA = 57%, p < .001, chance-level 25%). The mean distance between the predicted and the true focus of attention was 0.62 letter positions, which represented a mean error of 0.55 degrees of visual angle. In addition, ERP responses also successfully predicted whether spatial attention was allocated or not to a given location with an accuracy of 79% (p < .001). These findings are discussed in terms of their implications for visuospatial attention decoding and future paths for research are proposed. PMID:27529476

  15. Decoding the Locus of Covert Visuospatial Attention from EEG Signals.

    Science.gov (United States)

    Thiery, Thomas; Lajnef, Tarek; Jerbi, Karim; Arguin, Martin; Aubin, Mercedes; Jolicoeur, Pierre

    2016-01-01

    Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP) components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. In this study, we used a modified Posner cueing task with an endogenous cue to determine the degree to which information in the EEG signal can be used to track visual spatial attention in presentation sequences lasting 200 ms. We used a machine learning classification method to evaluate how well EEG signals discriminate between four different locations of the focus of attention. We then used a multi-class support vector machine (SVM) and a leave-one-out cross-validation framework to evaluate the decoding accuracy (DA). We found that ERP-based features from occipital and parietal regions showed a statistically significant valid prediction of the location of the focus of visuospatial attention (DA = 57%, p < .001, chance-level 25%). The mean distance between the predicted and the true focus of attention was 0.62 letter positions, which represented a mean error of 0.55 degrees of visual angle. In addition, ERP responses also successfully predicted whether spatial attention was allocated or not to a given location with an accuracy of 79% (p < .001). These findings are discussed in terms of their implications for visuospatial attention decoding and future paths for research are proposed.

  16. Decoding the Locus of Covert Visuospatial Attention from EEG Signals.

    Directory of Open Access Journals (Sweden)

    Thomas Thiery

    Full Text Available Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. In this study, we used a modified Posner cueing task with an endogenous cue to determine the degree to which information in the EEG signal can be used to track visual spatial attention in presentation sequences lasting 200 ms. We used a machine learning classification method to evaluate how well EEG signals discriminate between four different locations of the focus of attention. We then used a multi-class support vector machine (SVM and a leave-one-out cross-validation framework to evaluate the decoding accuracy (DA. We found that ERP-based features from occipital and parietal regions showed a statistically significant valid prediction of the location of the focus of visuospatial attention (DA = 57%, p < .001, chance-level 25%. The mean distance between the predicted and the true focus of attention was 0.62 letter positions, which represented a mean error of 0.55 degrees of visual angle. In addition, ERP responses also successfully predicted whether spatial attention was allocated or not to a given location with an accuracy of 79% (p < .001. These findings are discussed in terms of their implications for visuospatial attention decoding and future paths for research are proposed.

  17. Mapping of H.264 decoding on a multiprocessor architecture

    Science.gov (United States)

    van der Tol, Erik B.; Jaspers, Egbert G.; Gelderblom, Rob H.

    2003-05-01

    Due to the increasing significance of development costs in the competitive domain of high-volume consumer electronics, generic solutions are required to enable reuse of the design effort and to increase the potential market volume. As a result from this, Systems-on-Chip (SoCs) contain a growing amount of fully programmable media processing devices as opposed to application-specific systems, which offered the most attractive solutions due to a high performance density. The following motivates this trend. First, SoCs are increasingly dominated by their communication infrastructure and embedded memory, thereby making the cost of the functional units less significant. Moreover, the continuously growing design costs require generic solutions that can be applied over a broad product range. Hence, powerful programmable SoCs are becoming increasingly attractive. However, to enable power-efficient designs, that are also scalable over the advancing VLSI technology, parallelism should be fully exploited. Both task-level and instruction-level parallelism can be provided by means of e.g. a VLIW multiprocessor architecture. To provide the above-mentioned scalability, we propose to partition the data over the processors, instead of traditional functional partitioning. An advantage of this approach is the inherent locality of data, which is extremely important for communication-efficient software implementations. Consequently, a software implementation is discussed, enabling e.g. SD resolution H.264 decoding with a two-processor architecture, whereas High-Definition (HD) decoding can be achieved with an eight-processor system, executing the same software. Experimental results show that the data communication considerably reduces up to 65% directly improving the overall performance. Apart from considerable improvement in memory bandwidth, this novel concept of partitioning offers a natural approach for optimally balancing the load of all processors, thereby further improving the

  18. Decoding continuous three-dimensional hand trajectories from epidural electrocorticographic signals in Japanese macaques.

    Science.gov (United States)

    Shimoda, Kentaro; Nagasaka, Yasuo; Chao, Zenas C; Fujii, Naotaka

    2012-06-01

    Brain–machine interface (BMI) technology captures brain signals to enable control of prosthetic or communication devices with the goal of assisting patients who have limited or no ability to perform voluntary movements. Decoding of inherent information in brain signals to interpret the user’s intention is one of main approaches for developing BMI technology. Subdural electrocorticography (sECoG)-based decoding provides good accuracy, but surgical complications are one of the major concerns for this approach to be applied in BMIs. In contrast, epidural electrocorticography (eECoG) is less invasive, thus it is theoretically more suitable for long-term implementation, although it is unclear whether eECoG signals carry sufficient information for decoding natural movements. We successfully decoded continuous three-dimensional hand trajectories from eECoG signals in Japanese macaques. A steady quantity of information of continuous hand movements could be acquired from the decoding system for at least several months, and a decoding model could be used for ∼10 days without significant degradation in accuracy or recalibration. The correlation coefficients between observed and predicted trajectories were lower than those for sECoG-based decoding experiments we previously reported, owing to a greater degree of chewing artifacts in eECoG-based decoding than is found in sECoG-based decoding. As one of the safest invasive recording methods available, eECoG provides an acceptable level of performance. With the ease of replacement and upgrades, eECoG systems could become the first-choice interface for real-life BMI applications.

  19. Convergence Analysis of Turbo Decoding of Serially Concatenated Block Codes and Product Codes

    Science.gov (United States)

    Krause, Amir; Sella, Assaf; Be'ery, Yair

    2005-12-01

    The geometric interpretation of turbo decoding has founded a framework, and provided tools for the analysis of parallel-concatenated codes decoding. In this paper, we extend this analytical basis for the decoding of serially concatenated codes, and focus on serially concatenated product codes (SCPC) (i.e., product codes with checks on checks). For this case, at least one of the component (i.e., rows/columns) decoders should calculate the extrinsic information not only for the information bits, but also for the check bits. We refer to such a component decoder as a serial decoding module (SDM). We extend the framework accordingly, derive the update equations for a general turbo decoder of SCPC, and the expressions for the main analysis tools: the Jacobian and stability matrices. We explore the stability of the SDM. Specifically, for high SNR, we prove that the maximal eigenvalue of the SDM's stability matrix approaches [InlineEquation not available: see fulltext.], where [InlineEquation not available: see fulltext.] is the minimum Hamming distance of the component code. Hence, for practical codes, the SDM is unstable. Further, we analyze the two turbo decoding schemes, proposed by Benedetto and Pyndiah, by deriving the corresponding update equations and by demonstrating the structure of their stability matrices for the repetition code and an SCPC code with [InlineEquation not available: see fulltext.] information bits. Simulation results for the Hamming [InlineEquation not available: see fulltext.] and Golay [InlineEquation not available: see fulltext.] codes are presented, analyzed, and compared to the theoretical results and to simulations of turbo decoding of parallel concatenation of the same codes.

  20. Decoding continuous limb movements from high-density epidural electrode arrays using custom spatial filters

    Science.gov (United States)

    Marathe, A. R.; Taylor, D. M.

    2013-06-01

    Objective. Our goal was to identify spatial filtering methods that would improve decoding of continuous arm movements from epidural field potentials as well as demonstrate the use of the epidural signals in a closed-loop brain-machine interface (BMI) system in monkeys. Approach. Eleven spatial filtering options were compared offline using field potentials collected from 64-channel high-density epidural arrays in monkeys. Arrays were placed over arm/hand motor cortex in which intracortical microelectrodes had previously been implanted and removed leaving focal cortical damage but no lasting motor deficits. Spatial filters tested included: no filtering, common average referencing (CAR), principle component analysis, and eight novel modifications of the common spatial pattern (CSP) algorithm. The spatial filtering method and decoder combination that performed the best offline was then used online where monkeys controlled cursor velocity using continuous wrist position decoded from epidural field potentials in real time. Main results. Optimized CSP methods improved continuous wrist position decoding accuracy by 69% over CAR and by 80% compared to no filtering. Kalman decoders performed better than linear regression decoders and benefitted from including more spatially-filtered signals but not from pre-smoothing the calculated power spectra. Conversely, linear regression decoders required fewer spatially-filtered signals and were improved by pre-smoothing the power values. The ‘position-to-velocity’ transformation used during online control enabled the animals to generate smooth closed-loop movement trajectories using the somewhat limited position information available in the epidural signals. The monkeys’ online performance significantly improved across days of closed-loop training. Significance. Most published BMI studies that use electrocorticographic signals to decode continuous limb movements either use no spatial filtering or CAR. This study suggests a

  1. Using Social Scientific Criteria to Evaluate Cultural Theories: Encoding/Decoding Evaluated

    Directory of Open Access Journals (Sweden)

    Evan L. Kropp

    2015-12-01

    Full Text Available This article transcends the issue of conflicting theoretical schools of thought to formulate a method of social scientific style theory evaluation for cultural studies. It is suggested that positivist social scientific models of theory critique can be used to assess cultural models of communication to determine if they should be classified as theories. A set of evaluation criteria is formulated as a guide and applied to Stuart Hall’s Encoding/Decoding to determine if it is a theory. Conclusions find the sharing of criteria between schools of thought is judicious, Encoding/Decoding fits the established criteria, and Encoding/Decoding should be referred to as a theory.

  2. The Guruswami--Sudan Decoding Algorithm for Reed--Solomon Codes

    Science.gov (United States)

    McEliece, R. J.

    2003-01-01

    This article is a tutorial discussion of the Guruswami-Sudan (GS) Reed-Solomon decoding algorithm, including self-contained treatments of the Kotter and Roth-Ruckenstein (RR) improvements. It also contains a number of new results, including a rigorous discussion of the average size of the decoder's list, an improvement in the RR algorithm's stopping rule, a simplified treatment of the combinatorics of weighted monomial orders, and a proof of the monotonicity of the GS decoding radius as a function of the interpolation multiplicity.

  3. Performance Analysis of Iterative Decoding Algorithms for PEG LDPC Codes in Nakagami Fading Channels

    Directory of Open Access Journals (Sweden)

    O. Al Rasheed

    2013-11-01

    Full Text Available In this paper we give a comparative analysis of decoding algorithms of Low Density Parity Check (LDPC codes in a channel with the Nakagami distribution of the fading envelope. We consider the Progressive Edge-Growth (PEG method and Improved PEG method for the parity check matrix construction, which can be used to avoid short girths, small trapping sets and a high level of error floor. A comparative analysis of several classes of LDPC codes in various propagation conditions and decoded using different decoding algorithms is also presented.

  4. Mutiple LDPC Decoding using Bitplane Correlation for Transform Domain Wyner-Ziv Video Coding

    DEFF Research Database (Denmark)

    Luong, Huynh Van; Huang, Xin; Forchhammer, Søren

    2011-01-01

    Distributed video coding (DVC) is an emerging video coding paradigm for systems which fully or partly exploit the source statistics at the decoder to reduce the computational burden at the encoder. This paper considers a Low Density Parity Check (LDPC) based Transform Domain Wyner-Ziv (TDWZ) video...... codec. To improve the LDPC coding performance in the context of TDWZ, this paper proposes a Wyner-Ziv video codec using bitplane correlation through multiple parallel LDPC decoding. The proposed scheme utilizes inter bitplane correlation to enhance the bitplane decoding performance. Experimental results...

  5. NP-Hardness of Reed-Solomon Decoding, and the Prouhet-Tarry-Escott Problem

    OpenAIRE

    Gandikota, Venkata; Ghazi, Badih; Grigorescu, Elena

    2016-01-01

    Establishing the complexity of {\\em Bounded Distance Decoding} for Reed-Solomon codes is a fundamental open problem in coding theory, explicitly asked by Guruswami and Vardy (IEEE Trans. Inf. Theory, 2005). The problem is motivated by the large current gap between the regime when it is NP-hard, and the regime when it is efficiently solvable (i.e., the Johnson radius). We show the first NP-hardness results for asymptotically smaller decoding radii than the maximum likelihood decoding radius of...

  6. K-wire position in tension-band wiring technique affects stability of wires and long-term outcome in surgical treatment of olecranon fractures.

    NARCIS (Netherlands)

    Linden, S.C. van der; Kampen, A. van; Jaarsma, R.L.

    2012-01-01

    BACKGROUND: Tension-band wiring (TBW) has been accepted as the treatment of choice for displaced olecranon fractures. The aim of this study was to examine the effect of K-wire position on instability of the K-wires in relation to local complications and radiological and clinical long-term outcome.

  7. Modeling and experimentation of a positioning system of SMA wires

    Science.gov (United States)

    Lei, KinFong; Yam, Yeung

    2000-06-01

    This work reports two modeling and control attempts performed on a positioning system comprising of linking SMA wires and an overlooking video system for on-line measurements. The first attempt takes the model by Ikuta and identifies experimentally the parameters of the SMA wire. The identified single wire model is then extended to a system of two SMA wires joining together at their tips, based upon which open loop position control of the linkage is then conducted. The approach, however, becomes too complicated when more SMA wires are involved. The second attempt utilizes a neuro-fuzzy based approach for positioning control of a linkage point joining together four SMA wires. The second approach involves four ANFIS neuro-networks with hybrid learning algorithm trained to model the currents to the SMA wires as functions of present and target positions of the linkage point. Experimentation for both the two-wires and four-wires system yield quite satisfactory performance.

  8. Percutaneous tension band wiring for patellar fractures.

    Science.gov (United States)

    Rathi, Akhilesh; Swamy, M K S; Prasantha, I; Consul, Ashu; Bansal, Abhishek; Bahl, Vibhu

    2012-08-01

    To evaluate outcome of percutaneous tension band wiring for transverse fractures of the patella. 16 men and 7 women aged 27 to 65 (mean, 40) years underwent percutaneous tension band wiring for transverse fractures of the patella with a displacement of >3 mm. Pain, operating time, mobility, functional score, and complications were evaluated. 20 patients underwent successful percutaneous tension band wiring. The remaining 3 patients in whom closed reduction failed underwent open reduction and tension band wiring. The mean operating time was 46 (range, 28-62) minutes. The mean follow-up period was 20 (range, 15-30) months. At the latest follow-up, all patients had regained full extension. The objective score was excellent in 20 patients and good in 3, whereas the subjective score was excellent in 17, good in 5, and fair in one. All patients had radiological union at week 8. One patient had patellofemoral arthritis (secondary to a postoperative articular step). Two patients developed superficial infections, which resolved after antibiotic therapy. Mean thigh muscle wasting was 0.7 (range, 0.4-1) cm. Three patients encountered hardware problems (impingement/irritation of the skin over the knee) necessitating implant removal. Percutaneous tension band wiring is a viable option for transverse fractures of the patella.

  9. EVALUATION OF INDUCTANCE WITH ELECTRICAL WIRES

    Directory of Open Access Journals (Sweden)

    V. Kudry

    2016-08-01

    Full Text Available In this paper proved the possibility of developing passive electronic inductive elements based replace metal wire that is wound inductor, the wire is made of electret. The relative permeability of the electret S  10 000, several orders of magnitude greater than the permeability of conventional insulation materials, i < 10, resulting current in the wire acquires properties bias current. The essence of innovation is to replace the source of of magnetic induction flow that pervades the core of the coil. According to the theory of electrodynamics, current bias, in contrast to conduction current, generated no movement of charge along the wire, but the change of the charge in the local volume.Equivalence bias current and conduction current is manifested in the possibility of forming a magnetic field. The flow through magnetic induction coil core regardless of the current it generates, creates voltage at its ends.The paper also shows the numeric characteristics that determine the effective frequency range, specified the reason why electric a wire with і < 10 can not generate magnetic flux through the core and serve as a passive reactive component.

  10. Wire scanner software and firmware issues

    Energy Technology Data Exchange (ETDEWEB)

    Gilpatrick, John Doug [Los Alamos National Laboratory

    2008-01-01

    The Los Alamos Neutron Science Center facility presently has 110 slow wire scanning profile measurement instruments located along its various beam lines. These wire scanners were developed and have been operating for at least 30 years. While the wire scanners solved many problems to operate and have served the facility well they have increasingly suffered from several problems or limitations, such as maintenance and reliability problems, antiquated components, slow data acquisition, and etc. In order to refurbish these devices, these wire scanners will be replaced with newer versions. The replacement will consist of a completely new beam line actuator, new cables, new electronics and brand new software and firmware. This note describes the functions and modes of operation that LabVIEW VI software on the real time controller and FPGA LabVIEW firmware will be required. It will be especially interesting to understand the overall architecture of these LabVIEW VIs. While this note will endeavor to describe all of the requirements and issues for the wire scanners, undoubtedly, there will be missing details that will be added as time progresses.

  11. The PS Booster Fast Wire Scanner

    CERN Document Server

    Burger, S; Priestnall, K; Raich, U

    2003-01-01

    The very tight emittance budget for LHC type beams makes precise emittance measurements in the injector complex a necessity. The PS machine uses 2 fast wire scanners per transverse plane for emittance measurement of the circulating beams. In order to ease comparison the same type of wire scanners have been newly installed in the upstream machine, the PS Booster, where each of the 4 rings is equipped with 2 wire scanners measuring the horizontal and vertical profiles. Those wire scanners use new and more modern control and readout electronics featuring dedicated intelligent motor movement controllers, which relieves the very stringent real time constraints due to the very high speed of 20m/s. In order to be able to measure primary beams at the very low injection energy of the Booster (50MeV) secondary emission currents from the wire can be measured as well as secondary particle flows at higher primary particle energies during and after acceleration. The solution adopted for the control of the devices is descri...

  12. Forgotten Kirschner Wire Causing Severe Hematuria

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    2014-01-01

    Full Text Available Kirschner wire (K-wire is commonly used in the treatment of hip fracture and its migration into pelvis leading to bladder injury is a very rare complication. Nonremoval of these devices either because of lack of followup or because of prolonged requirement due to disease process is associated with this complication. We report a case of a patient who presented with acute onset severe hematuria with clot retention secondary to perforation of bladder by a migrated K-wire placed earlier, for the treatment of hip fracture. Initial imaging showed its presence in the soft tissues of the pelvis away from the major vascular structures. Patient was taken for emergency laparotomy and wire was removed after cystotomy. Postoperative period was uneventful and patient was discharged in satisfactory condition. K-wires are commonly used in the management of fracture bones and their migration has been reported in the literature although such migration in the intrapelvic region involving bladder is very rare. Early diagnosis and prompt removal of such foreign bodies are required to avert potentially fatal involvement of major structures.

  13. Dynamics of Anderson localization in disordered wires

    Science.gov (United States)

    Khalaf, E.; Ostrovsky, P. M.

    2017-11-01

    We consider the dynamics of an electron in an infinite disordered metallic wire. We derive exact expressions for the probability of diffusive return to the starting point in a given time. The result is valid for wires with or without time-reversal symmetry and allows for the possibility of topologically protected conducting channels. In the absence of protected channels, Anderson localization leads to a nonzero limiting value of the return probability at long times, which is approached as a negative power of time with an exponent depending on the symmetry class. When topologically protected channels are present (in a wire of either unitary or symplectic symmetry), the probability of return decays to zero at long time as a power law whose exponent depends on the number of protected channels. Technically, we describe the electron dynamics by the one-dimensional supersymmetric nonlinear sigma model. We derive an exact identity that relates any local dynamical correlation function in a disordered wire of unitary, orthogonal, or symplectic symmetry to a certain expectation value in the random matrix ensemble of class AIII, CI, or DIII, respectively. The established exact mapping from a one- to a zero-dimensional sigma model is very general and can be used to compute any local observable in a disordered wire.

  14. Integrated Electrical Wire Insulation Repair System

    Science.gov (United States)

    Williams, Martha; Jolley, Scott; Gibson, Tracy; Parks, Steven

    2013-01-01

    An integrated system tool will allow a technician to easily and quickly repair damaged high-performance electrical wire insulation in the field. Low-melt polyimides have been developed that can be processed into thin films that work well in the repair of damaged polyimide or fluoropolymer insulated electrical wiring. Such thin films can be used in wire insulation repairs by affixing a film of this low-melt polyimide to the damaged wire, and heating the film to effect melting, flow, and cure of the film. The resulting repair is robust, lightweight, and small in volume. The heating of this repair film is accomplished with the use of a common electrical soldering tool that has been modified with a special head or tip that can accommodate the size of wire being repaired. This repair method can furthermore be simplified for the repair technician by providing replaceable or disposable soldering tool heads that have repair film already "loaded" and ready for use. The soldering tool heating device can also be equipped with a battery power supply that will allow its use in areas where plug-in current is not available

  15. Temperature Dependent Wire Delay Estimation in Floorplanning

    DEFF Research Database (Denmark)

    Winther, Andreas Thor; Liu, Wei; Nannarelli, Alberto

    2011-01-01

    Due to large variations in temperature in VLSI circuits and the linear relationship between metal resistance and temperature, the delay through wires of the same length can be different. Traditional thermal aware floorplanning algorithms use wirelength to estimate delay and routability....... In this work, we show that using wirelength as the evaluation metric does not always produce a floorplan with the shortest delay. We propose a temperature dependent wire delay estimation method for thermal aware floorplanning algorithms, which takes into account the thermal effect on wire delay. The experiment...... results show that a shorter delay can be achieved using the proposed method. In addition, we also discuss the congestion and reliability issues as they are closely related to routing and temperature....

  16. A new route to process diamond wires

    Directory of Open Access Journals (Sweden)

    Marcello Filgueira

    2003-06-01

    Full Text Available We propose an original route to process diamond wires, denominated In Situ Technology, whose fabrication involves mechanical conformation processes, such as rotary forging, copper tubes restacking, and thermal treatments, such as sintering and recrystallisation of a bronze 4 wt.% diamond composite. Tensile tests were performed, reaching an ultimate tensile strength (UTS of 230 MPa for the diameter of Æ = 1.84 mm. Scanning electron microscopy showed the diamond crystals distribution along the composite rope during its manufacture, as well as the diamond adhesion to the bronze matrix. Cutting tests were carried out with the processed wire, showing a probable performance 4 times higher than the diamond sawing discs, however its probable performance was about 5 to 8 times less than the conventional diamond wires (pearl system due to the low abrasion resistance of the bronze matrix, and low adhesion between the pair bronze-diamond due to the use of not metallised diamond single crystals.

  17. Magnetic wires in MEMS and bio-medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Barbic, Mladen E-mail: mladen@caltech.edu

    2002-08-01

    Magnetic wires of appropriate design have special features making them useful to micro-electromechanical systems and bio-medical applications. Several applications that exploit the properties of magnetic wires are reviewed including: (a) a magnetic micro-manipulation technique that utilizes integrated micro-coils and magnetic micro-wires for localized positioning of micron-sized magnetic objects, (b) integrated micro-coil/micro-wire system operating as a micro-fluidic micro-motor, (c) mechanical tweezers using magneto-static interaction between two magnetic micro-wires, and (d) ultra-high gradient magnetic separation system based on porous membranes partially filled with magnetic wires.

  18. Recent advances in coding theory for near error-free communications

    Science.gov (United States)

    Cheung, K.-M.; Deutsch, L. J.; Dolinar, S. J.; Mceliece, R. J.; Pollara, F.; Shahshahani, M.; Swanson, L.

    1991-01-01

    Channel and source coding theories are discussed. The following subject areas are covered: large constraint length convolutional codes (the Galileo code); decoder design (the big Viterbi decoder); Voyager's and Galileo's data compression scheme; current research in data compression for images; neural networks for soft decoding; neural networks for source decoding; finite-state codes; and fractals for data compression.

  19. Feature reconstruction of LFP signals based on PLSR in the neural information decoding study.

    Science.gov (United States)

    Yonghui Dong; Zhigang Shang; Mengmeng Li; Xinyu Liu; Hong Wan

    2017-07-01

    To solve the problems of Signal-to-Noise Ratio (SNR) and multicollinearity when the Local Field Potential (LFP) signals is used for the decoding of animal motion intention, a feature reconstruction of LFP signals based on partial least squares regression (PLSR) in the neural information decoding study is proposed in this paper. Firstly, the feature information of LFP coding band is extracted based on wavelet transform. Then the PLSR model is constructed by the extracted LFP coding features. According to the multicollinearity characteristics among the coding features, several latent variables which contribute greatly to the steering behavior are obtained, and the new LFP coding features are reconstructed. Finally, the K-Nearest Neighbor (KNN) method is used to classify the reconstructed coding features to verify the decoding performance. The results show that the proposed method can achieve the highest accuracy compared to the other three methods and the decoding effect of the proposed method is robust.

  20. Encoding and decoding of digital spiral imaging based on bidirectional transformation of light's spatial eigenmodes.

    Science.gov (United States)

    Zhang, Wuhong; Chen, Lixiang

    2016-06-15

    Digital spiral imaging has been demonstrated as an effective optical tool to encode optical information and retrieve topographic information of an object. Here we develop a conceptually new and concise scheme for optical image encoding and decoding toward free-space digital spiral imaging. We experimentally demonstrate that the optical lattices with ℓ=±50 orbital angular momentum superpositions and a clover image with nearly 200 Laguerre-Gaussian (LG) modes can be well encoded and successfully decoded. It is found that an image encoded/decoded with a two-index LG spectrum (considering both azimuthal and radial indices, ℓ and p) possesses much higher fidelity than that with a one-index LG spectrum (only considering the ℓ index). Our work provides an alternative tool for the image encoding/decoding scheme toward free-space optical communications.

  1. Decoding Dyslexia, a Common Learning Disability | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... JavaScript on. Feature: Dyslexia Decoding Dyslexia, a Common Learning Disability Past Issues / Winter 2016 Table of Contents What Are Learning Disabilities? Learning disabilities affect how someone learns to read, ...

  2. Application of MTR soft-decision decoding in multiple-head ...

    Indian Academy of Sciences (India)

    Transition-Run (MTR) codes has ... Research of iterative decoding/detection techniques (Berrou et al 1993) for applications in magnetic recordings, have created a ..... The main advantage of employing SOVA detector, however, is a reduction in ...

  3. Multilevel Coding for the Full-Duplex Decode-Compress-Forward Relay Channel

    Directory of Open Access Journals (Sweden)

    Ahmed Attia Abotabl

    2017-11-01

    Full Text Available The Decode-Compress-Forward (DCF is a generalization of Decode-Forward (DF and Compress-Forward (CF. This paper investigates conditions under which DCF offers gains over DF and CF, addresses the problem of coded modulation for DCF, and evaluates the performance of DCF coded modulation implemented via low-density parity-check (LDPC codes and polar codes. We begin by revisiting the achievable rate of DCF in discrete memoryless channels under backward decoding. We then study coded modulation for the decode-compress-forward via multi-level coding. We show that the proposed multilevel coding approaches the known achievable rates of DCF. The proposed multilevel coding is implemented (and its performance verified via a combination of standard DVB-S2 LDPC codes, and polar codes whose design follows the method of Blasco-Serrano.

  4. Decoding development in the XXI century: subjectivity, complexity, sinapsis, sinergy, recursivity, lidership and territorial dependency

    National Research Council Canada - National Science Library

    Sergio Boisier

    2010-01-01

      BOISIER, Sergio. Decoding development in the XXI century: subjectivity, complexity, sinapsis, sinergy, recursivity, lidership and territorial dependency. Semest. Econ. [online]. 2010, vol.13, n.27, pp. 11-37. ISSN 0120-6346...

  5. Turbo codes for multi-hop wireless sensor networks with decode-and-forward mechanism

    National Research Council Canada - National Science Library

    Abughalieh, Nashat; Steenhaut, Kris; Nowé, Ann; Anpalagan, Alagan

    2014-01-01

    .... Error correcting codes (ECCs) can be used to reduce number of retransmissions, but most ECCs have complex decoding algorithms, which leads to high processing energy consumption at the receiving nodes in the WSN...

  6. Phonological Awareness and Decoding in Deaf/Hard-of-Hearing Students Who Use Visual Phonics

    National Research Council Canada - National Science Library

    Rachel F. Narr

    2008-01-01

    .... This study was designed to examine the relationship between performance on a phonological awareness task, performance on a decoding task, reading ability, and length of time in literacy instruction...

  7. Quantum conductance in silicon quantum wires

    CERN Document Server

    Bagraev, N T; Klyachkin, L E; Malyarenko, A M; Gehlhoff, W; Ivanov, V K; Shelykh, I A

    2002-01-01

    The results of investigations of electron and hole quantum conductance staircase in silicon quantum wires are presented. The characteristics of self-ordering quantum wells of n- and p-types, which from on the silicon (100) surface in the nonequilibrium boron diffusion process, are analyzed. The results of investigations of the quantum conductance as the function of temperature, carrier concentration and modulation degree of silicon quantum wires are given. It is found out, that the quantum conductance of the one-dimensional channels is observed, for the first time, at an elevated temperature (T >= 77 K)

  8. Laser wire emittance measurement line AT CLIC

    CERN Document Server

    Garcia, H; Blair, G A; Aumeyr, T; Schulte, D; Stulle, F

    2011-01-01

    A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the RTML line of the CLIC using laser-wire beam profile monitors is described. A lattice of the measurement line is discussed and results of simulations of statistical errors and of their impact on the accuracy of the emittance reconstruction are given. Laser wire systems suitable for CLIC and their main characteristics are discussed.

  9. Transient response of wire bicone antennas

    Science.gov (United States)

    Morgan, J. G.; Lizius, D. W.

    This paper describes the computational analysis of biconical wire antennas without end-caps performed using an extended and improved version of the Thin Wire Time Domain code from the Lawrence Livermore National Laboratory. Special attention is given to the computational algorithm used in the direct time domain analysis of the transient behavior of antennas. It is shown that the time domain numerical predictions are consistent with intuitive expectations and with predictions obtained from the Fourier transform of a frequency domain semianalytical model of a sheet bicone antenna.

  10. Numerical Simulation of Wire-Coating

    DEFF Research Database (Denmark)

    Wapperom, Peter; Hassager, Ole

    1999-01-01

    A finite element program has been used to analyze the wire-coating process of an MDPE melt. The melt is modeled by a nonisothermal Carreau model. The emphasis is on predicting an accurate temperature field. Therefore, it is necessary to include the heat conduction in the metal parts. A comparison...... is made with the results of a simulation that models the heat conduction in the metal head by means of a Biot boundary condition. The influence of the wire velocity, inlet temperature and power-law index will be examined....

  11. EDITORIAL More than a wire More than a wire

    Science.gov (United States)

    Demming, Anna

    2010-10-01

    Nanowires are the natural evolution of the connections in circuits when scaled down to nanometre sizes. On closer inspection, of course, the role of nanowires in developing new technologies is much more than just a current-bearing medium. By sizing the diameters of these objects down to the nanoscale, their properties become increasingly sensitive to factors such as the gas composition, temperature and incident light of their surrounding environment, as well as defects and variations in diameter. What becomes important in modern electronics innovations is not just what is connected, but how. Nanowires had already begun to attract the attention of researchers in the early 1990s as advances in imaging and measurement devices invited researchers to investigate the properties of these one-dimensional structures [1, 2]. This interest has sparked ingenious ways of fabricating nanowires such as the use of a DNA template. A collaboration of researchers at Louisiana Tech University in the US hs provided an overview of various methods to assemble conductive nanowires on a DNA template, including a summary of different approaches to stretching and positioning the templates [3]. Work in this area demonstrates a neat parallel for the role of DNA molecules as the building blocks of life and the foundations of nanoscale device architectures. Scientists at HP Labs in California are using nanowires to shrink the size of logic arrays [4]. One aspect of electronic interconnects that requires particular attention at nanoscale sizes is the effect of defects. The researchers at HP Labs demonstrate that their approach, which they name FPNI (field-programmable nanowire interconnect), is extremely tolerant of the high defect rates likely to be found in these nanoscale structures, and allows reduction in size and power without significantly sacrificing the clock rate. Another issue in scaling down electronics is the trend for an increasing resistivity with decreasing wire width. Researchers

  12. Predicting plant immunity gene expression by identifying the decoding mechanism of calcium signatures.

    OpenAIRE

    Lenzoni, G.; Liu, J.; Knight, M.R.

    2018-01-01

    Calcium plays a key role in determining the specificity of a vast array of signalling pathways in plants. Cellular calcium elevations with different characteristics (calcium signatures) carry information on the identity of the primary stimulus, ensuring appropriate downstream responses. However, the mechanism for decoding calcium signatures is unknown. To determine this, decoding of the salicylic acid (SA)-mediated plant immunity signalling network controlling gene expression was examined. ...

  13. Decoding Individual Finger Movements from One Hand Using Human EEG Signals

    Science.gov (United States)

    Gonzalez, Jania; Ding, Lei

    2014-01-01

    Brain computer interface (BCI) is an assistive technology, which decodes neurophysiological signals generated by the human brain and translates them into control signals to control external devices, e.g., wheelchairs. One problem challenging noninvasive BCI technologies is the limited control dimensions from decoding movements of, mainly, large body parts, e.g., upper and lower limbs. It has been reported that complicated dexterous functions, i.e., finger movements, can be decoded in electrocorticography (ECoG) signals, while it remains unclear whether noninvasive electroencephalography (EEG) signals also have sufficient information to decode the same type of movements. Phenomena of broadband power increase and low-frequency-band power decrease were observed in EEG in the present study, when EEG power spectra were decomposed by a principal component analysis (PCA). These movement-related spectral structures and their changes caused by finger movements in EEG are consistent with observations in previous ECoG study, as well as the results from ECoG data in the present study. The average decoding accuracy of 77.11% over all subjects was obtained in classifying each pair of fingers from one hand using movement-related spectral changes as features to be decoded using a support vector machine (SVM) classifier. The average decoding accuracy in three epilepsy patients using ECoG data was 91.28% with the similarly obtained features and same classifier. Both decoding accuracies of EEG and ECoG are significantly higher than the empirical guessing level (51.26%) in all subjects (pEEG as in ECoG, and demonstrates the feasibility of discriminating finger movements from one hand using EEG. These findings are promising to facilitate the development of BCIs with rich control signals using noninvasive technologies. PMID:24416360

  14. Performances of Neural Networks and LDPC Decoders for OFDM High Speed Transmission in Optical Fiber

    OpenAIRE

    Sanou Serge Roland 1, 2 * , Zougmoré François 1 , Kébré Marcel 1 , Koalaga Zacharie 1 , Doumounia Ali

    2013-01-01

    This paper presents a comparison of the performances of coded OFDM (Orthogonal Frequency Division Multiplexing) for optical broadband transmission using Random Neural Network (RNN), a variant of RNN, Soft Decision Decoding (SDD) and LDPC channel decoding techniques. The performance evaluation is based firstly on the Error Vector Magnitude (EVM) to assess the effects of imperfections in the optical channel, and secondly on the estimated Bit Error Rate (BER) base...

  15. On the Development and Optimization of HEVC Video Decoders Using High-Level Dataflow Modeling

    OpenAIRE

    Jerbi, Khaled; Yviquel, Hervé; Sanchez, Alexandre; Renzi, Daniele; De Saint Jorre, Damien; Alberti, Claudio; Mattavelli, Marco; Raulet, Mickael

    2017-01-01

    International audience; With the emergence of the High Efficiency Video Coding (HEVC) standard, a dataflow description of the decoder part was developed as part of the MPEG-B standard. This dataflow description presented modest framerate results which led us to propose methodolo-gies to improve the performance. In this paper, we introduce architectural improvements by exposing more parallelism using YUV and frame-based parallel decoding. We also present platform optimizations based on the use...

  16. LDPC code decoding adapted to the precoded partial response magnetic recording channels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jun E-mail: leejun28@sait.samsung.co.kr; Kim, Kyuyong; Lee, Jaejin; Yang, Gijoo

    2004-05-01

    We propose a signal processing technique using LDPC (low-density parity-check) code instead of PRML (partial response maximum likelihood) system for the longitudinal magnetic recording channel. The scheme is designed by the precoder admitting level detection at the receiver-end and modifying the likelihood function for LDPC code decoding. The scheme can be collaborated with other decoder for turbo-like systems. The proposed algorithm can contribute to improve the performance of the conventional turbo-like systems.

  17. Decoder calibration with ultra small current sample set for intracortical brain-machine interface.

    Science.gov (United States)

    Zhang, Peng; Ma, Xuan; Chen, Luyao; Zhou, Jin; Wang, Changyong; Li, Wei; He, Jiping

    2018-04-01

    Intracortical brain-machine interfaces (iBMIs) aim to restore efficient communication and movement ability for paralyzed patients. However, frequent recalibration is required for consistency and reliability, and every recalibration will require relatively large most current sample set. The aim in this study is to develop an effective decoder calibration method that can achieve good performance while minimizing recalibration time. Two rhesus macaques implanted with intracortical microelectrode arrays were trained separately on movement and sensory paradigm. Neural signals were recorded to decode reaching positions or grasping postures. A novel principal component analysis-based domain adaptation (PDA) method was proposed to recalibrate the decoder with only ultra small current sample set by taking advantage of large historical data, and the decoding performance was compared with other three calibration methods for evaluation. The PDA method closed the gap between historical and current data effectively, and made it possible to take advantage of large historical data for decoder recalibration in current data decoding. Using only ultra small current sample set (five trials of each category), the decoder calibrated using the PDA method could achieve much better and more robust performance in all sessions than using other three calibration methods in both monkeys. (1) By this study, transfer learning theory was brought into iBMIs decoder calibration for the first time. (2) Different from most transfer learning studies, the target data in this study were ultra small sample set and were transferred to the source data. (3) By taking advantage of historical data, the PDA method was demonstrated to be effective in reducing recalibration time for both movement paradigm and sensory paradigm, indicating a viable generalization. By reducing the demand for large current training data, this new method may facilitate the application of intracortical brain-machine interfaces in

  18. Decoding individual finger movements from one hand using human EEG signals.

    Science.gov (United States)

    Liao, Ke; Xiao, Ran; Gonzalez, Jania; Ding, Lei

    2014-01-01

    Brain computer interface (BCI) is an assistive technology, which decodes neurophysiological signals generated by the human brain and translates them into control signals to control external devices, e.g., wheelchairs. One problem challenging noninvasive BCI technologies is the limited control dimensions from decoding movements of, mainly, large body parts, e.g., upper and lower limbs. It has been reported that complicated dexterous functions, i.e., finger movements, can be decoded in electrocorticography (ECoG) signals, while it remains unclear whether noninvasive electroencephalography (EEG) signals also have sufficient information to decode the same type of movements. Phenomena of broadband power increase and low-frequency-band power decrease were observed in EEG in the present study, when EEG power spectra were decomposed by a principal component analysis (PCA). These movement-related spectral structures and their changes caused by finger movements in EEG are consistent with observations in previous ECoG study, as well as the results from ECoG data in the present study. The average decoding accuracy of 77.11% over all subjects was obtained in classifying each pair of fingers from one hand using movement-related spectral changes as features to be decoded using a support vector machine (SVM) classifier. The average decoding accuracy in three epilepsy patients using ECoG data was 91.28% with the similarly obtained features and same classifier. Both decoding accuracies of EEG and ECoG are significantly higher than the empirical guessing level (51.26%) in all subjects (psignals using noninvasive technologies.

  19. Decoding individual finger movements from one hand using human EEG signals.

    Directory of Open Access Journals (Sweden)

    Ke Liao

    Full Text Available Brain computer interface (BCI is an assistive technology, which decodes neurophysiological signals generated by the human brain and translates them into control signals to control external devices, e.g., wheelchairs. One problem challenging noninvasive BCI technologies is the limited control dimensions from decoding movements of, mainly, large body parts, e.g., upper and lower limbs. It has been reported that complicated dexterous functions, i.e., finger movements, can be decoded in electrocorticography (ECoG signals, while it remains unclear whether noninvasive electroencephalography (EEG signals also have sufficient information to decode the same type of movements. Phenomena of broadband power increase and low-frequency-band power decrease were observed in EEG in the present study, when EEG power spectra were decomposed by a principal component analysis (PCA. These movement-related spectral structures and their changes caused by finger movements in EEG are consistent with observations in previous ECoG study, as well as the results from ECoG data in the present study. The average decoding accuracy of 77.11% over all subjects was obtained in classifying each pair of fingers from one hand using movement-related spectral changes as features to be decoded using a support vector machine (SVM classifier. The average decoding accuracy in three epilepsy patients using ECoG data was 91.28% with the similarly obtained features and same classifier. Both decoding accuracies of EEG and ECoG are significantly higher than the empirical guessing level (51.26% in all subjects (p<0.05. The present study suggests the similar movement-related spectral changes in EEG as in ECoG, and demonstrates the feasibility of discriminating finger movements from one hand using EEG. These findings are promising to facilitate the development of BCIs with rich control signals using noninvasive technologies.

  20. A Novel Brain Decoding Method: a Correlation Network Framework for Revealing Brain Connections

    OpenAIRE

    Yu, Siyu; Zheng, Nanning; Ma, Yongqiang; Wu, Hao; Chen, Badong

    2017-01-01

    Brain decoding is a hot spot in cognitive science, which focuses on reconstructing perceptual images from brain activities. Analyzing the correlations of collected data from human brain activities and representing activity patterns are two problems in brain decoding based on functional magnetic resonance imaging (fMRI) signals. However, existing correlation analysis methods mainly focus on the strength information of voxel, which reveals functional connectivity in the cerebral cortex. They te...

  1. Wire grid polarizers for visible wavelengths

    Science.gov (United States)

    Johnson, Joshua Hans

    Detailed analysis of wire-grid (WG) polarizers for visible wavelengths is presented. Rigorous coupled-wave analysis (RCWA) is used to model their performance. The optimum choice of metal for the wires is identified, and the effects of different substrate indices of refraction are considered. The polarization properties are considered with changes in the physical parameters, including period, duty cycle, and wire thickness. It is shown that the performance of WG polarizers improves with increasing angle of incidence. The effect of non-square wire profiles is considered, as is the effect of adding additional dielectric layers between the wires and the substrate. The effect of metal oxide layers forming on the wires is also modeled. While most of this work concerns WG polarizers used in transmission, the performance in reflection is also discussed. Several visible-wavelength WG polarizers were fabricated at the Cornell Nanofabrication Facility (CNF) in Ithaca, NY. Electron-beam lithography was used to write the patterns for these devices, and two different methods of pattern transfer were compared. These were the lift-off method and reactive-ion etching (RIE). We found that lift-off could not produce wires thick enough for good polarization properties. RIE could produce much thicker wires with good profiles and was used for all of the experimental work presented here. Two different methods for metal film deposition, evaporation and sputtering were also compared. Films deposited by sputtering were found to have much lower indices of refraction and to not respond to etching as well. Thermally evaporated films performed much better in WG polarizers. Alternative methods for the mass-production of visible-wavelength WG polarizers are also discussed. The performance of the fabricated WG polarizers is compared to theory. When the measured physical parameters are used in RCWA to predict the performance, the measured extinction ratio is found to be much lower than the

  2. Improved fault tolerance of Turbo decoding based on optimized index assignments

    Science.gov (United States)

    Geldmacher, J.; Götze, J.

    2014-11-01

    This paper investigates the impact of an error-prone buffer memory on a channel decoder as employed in modern digital communication systems. On one hand this work is motivated by the fact that energy efficient decoder implementations may not only be achieved by optimizations on algorithmic level, but also by chip-level modifications. One of such modifications is so called aggressive voltage scaling of buffer memories, which, while achieving reduced power consumption, also injects errors into the likelihood values used during the decoding process. On the other hand, it has been recognized that the ongoing increase of integration density with smaller structures makes integrated circuits more sensitive to process variations during manufacturing, and to voltage and temperature variations. This may lead to a paradigm shift from 100 %-reliable operation to fault tolerant signal processing. Both reasons are the motivation to discuss the required co-design of algorithms and underlying circuits. For an error-prone receive buffer of a Turbo decoder the influence of quantizer design and index assignment on the error resilience of the decoding algorithm is discussed. It is shown that a suitable design of both enables a compensation of hardware induced bits errors with rates up to 1 % without increasing the computational complexity of the decoder.

  3. 1-State Error-Trellis Decoding of LDPC Convolutional Codes Based on Circulant Matrices

    CERN Document Server

    Tajima, Masato; Miyagoshi, Takashi

    2009-01-01

    We consider the decoding of convolutional codes using an error trellis constructed based on a submatrix of a given check matrix. In the proposed method, the syndrome-subsequence computed using the remaining submatrix is utilized as auxiliary information for decoding. Then the ML error path is correctly decoded using the degenerate error trellis. We also show that the decoding complexity of the proposed method is basically identical with that of the conventional one based on the original error trellis. Next, we apply the method to check matrices with monomial entries proposed by Tanner et al. By choosing any row of the check matrix as the submatrix for error-trellis construction, a 1-state error trellis is obtained. Noting the fact that a likelihood-concentration on the all-zero state and the states with many 0's occurs in the error trellis, we present a simplified decoding method based on a 1-state error trellis, from which decoding-complexity reduction is realized.

  4. TCP Traffic Control Evaluation and Reduction over Wireless Networks Using Parallel Sequential Decoding Mechanism

    Directory of Open Access Journals (Sweden)

    Ramazan Aygün

    2007-11-01

    Full Text Available The assumption of TCP-based protocols that packet error (lost or damaged is due to network congestion is not true for wireless networks. For wireless networks, it is important to reduce the number of retransmissions to improve the effectiveness of TCP-based protocols. In this paper, we consider improvement at the data link layer for systems that use stop-and-wait ARQ as in IEEE 802.11 standard. We show that increasing the buffer size will not solve the actual problem and moreover it is likely to degrade the quality of delivery (QoD. We firstly study a wireless router system model with a sequential convolutional decoder for error detection and correction in order to investigate QoD of flow and error control. To overcome the problems along with high packet error rate, we propose a wireless router system with parallel sequential decoders. We simulate our systems and provide performance in terms of average buffer occupancy, blocking probability, probability of decoding failure, system throughput, and channel throughput. We have studied these performance metrics for different channel conditions, packet arrival rates, decoding time-out limits, system capacities, and the number of sequential decoders. Our results show that parallel sequential decoders have great impact on the system performance and increase QoD significantly.

  5. TCP Traffic Control Evaluation and Reduction over Wireless Networks Using Parallel Sequential Decoding Mechanism

    Directory of Open Access Journals (Sweden)

    Aygün Ramazan

    2007-01-01

    Full Text Available The assumption of TCP-based protocols that packet error (lost or damaged is due to network congestion is not true for wireless networks. For wireless networks, it is important to reduce the number of retransmissions to improve the effectiveness of TCP-based protocols. In this paper, we consider improvement at the data link layer for systems that use stop-and-wait ARQ as in IEEE 802.11 standard. We show that increasing the buffer size will not solve the actual problem and moreover it is likely to degrade the quality of delivery (QoD. We firstly study a wireless router system model with a sequential convolutional decoder for error detection and correction in order to investigate QoD of flow and error control. To overcome the problems along with high packet error rate, we propose a wireless router system with parallel sequential decoders. We simulate our systems and provide performance in terms of average buffer occupancy, blocking probability, probability of decoding failure, system throughput, and channel throughput. We have studied these performance metrics for different channel conditions, packet arrival rates, decoding time-out limits, system capacities, and the number of sequential decoders. Our results show that parallel sequential decoders have great impact on the system performance and increase QoD significantly.

  6. Word Decoding Development during Phonics Instruction in Children at Risk for Dyslexia.

    Science.gov (United States)

    Schaars, Moniek M H; Segers, Eliane; Verhoeven, Ludo

    2017-05-01

    In the present study, we examined the early word decoding development of 73 children at genetic risk of dyslexia and 73 matched controls. We conducted monthly curriculum-embedded word decoding measures during the first 5 months of phonics-based reading instruction followed by standardized word decoding measures halfway and by the end of first grade. In kindergarten, vocabulary, phonological awareness, lexical retrieval, and verbal and visual short-term memory were assessed. The results showed that the children at risk were less skilled in phonemic awareness in kindergarten. During the first 5 months of reading instruction, children at risk were less efficient in word decoding and the discrepancy increased over the months. In subsequent months, the discrepancy prevailed for simple words but increased for more complex words. Phonemic awareness and lexical retrieval predicted the reading development in children at risk and controls to the same extent. It is concluded that children at risk are behind their typical peers in word decoding development starting from the very beginning. Furthermore, it is concluded that the disadvantage increased during phonics instruction and that the same predictors underlie the development of word decoding in the two groups of children. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  7. Utilizing Cross-Layer Information to Improve Performance in JPEG2000 Decoding

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    Hannes Persson

    2007-01-01

    Full Text Available We focus on wireless multimedia communication and investigate how cross-layer information can be used to improve performance at the application layer, using JPEG2000 as an example. The cross-layer information is in the form of soft information from the physical layer. The soft information, which is supplied by a soft decision demodulator, yields reliability measures for the received bits and is fed into two soft input iterative JPEG2000 image decoders. When errors are detected with the error detecting mechanisms in JPEG2000, the decoders utilize the soft information to point out likely transmission errors. Hence, the decoders can correct errors and increase the image quality without making time-consuming retransmissions. We believe that the proposed decoding method utilizing soft information is suitable for a general IP-based network and that it keeps the principles of a layered structure of the protocol stack intact. Further, experimental results with images transmitted over a simulated wireless channel show that a simple decoding algorithm that utilizes soft information can give high gains in image quality compared to the standard hard-decision decoding.

  8. The development of working memory from kindergarten to first grade in children with different decoding skills.

    Science.gov (United States)

    Nevo, Einat; Breznitz, Zvia

    2013-02-01

    This study investigated the development of working memory ability (measured by tasks assessing all four working memory components) from the end of kindergarten to the end of first grade-the first year reading is taught in school-and the relationship between working memory abilities in kindergarten and first grade and reading skills in first grade. A sample of 97 children who participated in Nevo and Breznitz's earlier study [Journal of Experimental Child Psychology, 109 (2011) 73-90] were divided into two groups according to their decoding skills, resulting in 24 poor decoders and 73 typical decoders. The entire cohort improved significantly on all of the working memory measures from kindergarten to first grade, with the phonological complex memory at both time points showing the highest correlations with reading skills at first grade. However, there were differences found between the two decoding groups, with poor decoders exhibiting lower working memory abilities in most working memory measures, performing significantly lower on tests of all three reading skills (decoding, reading comprehension, and reading speed), and showing higher correlation coefficients between reading skills. Findings suggest that even before formal teaching of reading begins, it is important to reinforce working memory abilities in order to maximize future reading achievements. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Time-varying block codes for synchronisation errors: maximum a posteriori decoder and practical issues

    Directory of Open Access Journals (Sweden)

    Johann A. Briffa

    2014-06-01

    Full Text Available In this study, the authors consider time-varying block (TVB codes, which generalise a number of previous synchronisation error-correcting codes. They also consider various practical issues related to maximum a posteriori (MAP decoding of these codes. Specifically, they give an expression for the expected distribution of drift between transmitter and receiver because of synchronisation errors. They determine an appropriate choice for state space limits based on the drift probability distribution. In turn, they obtain an expression for the decoder complexity under given channel conditions in terms of the state space limits used. For a given state space, they also give a number of optimisations that reduce the algorithm complexity with no further loss of decoder performance. They also show how the MAP decoder can be used in the absence of known frame boundaries, and demonstrate that an appropriate choice of decoder parameters allows the decoder to approach the performance when frame boundaries are known, at the expense of some increase in complexity. Finally, they express some existing constructions as TVB codes, comparing performance with published results and showing that improved performance is possible by taking advantage of the flexibility of TVB codes.

  10. Techniques and Architectures for Hazard-Free Semi-Parallel Decoding of LDPC Codes

    Directory of Open Access Journals (Sweden)

    Luca Fanucci

    2009-01-01

    Full Text Available The layered decoding algorithm has recently been proposed as an efficient means for the decoding of low-density parity-check (LDPC codes, thanks to the remarkable improvement in the convergence speed (2x of the decoding process. However, pipelined semi-parallel decoders suffer from violations or “hazards” between consecutive updates, which not only violate the layered principle but also enforce the loops in the code, thus spoiling the error correction performance. This paper describes three different techniques to properly reschedule the decoding updates, based on the careful insertion of “idle” cycles, to prevent the hazards of the pipeline mechanism. Also, different semi-parallel architectures of a layered LDPC decoder suitable for use with such techniques are analyzed. Then, taking the LDPC codes for the wireless local area network (IEEE 802.11n as a case study, a detailed analysis of the performance attained with the proposed techniques and architectures is reported, and results of the logic synthesis on a 65 nm low-power CMOS technology are shown.

  11. Techniques and Architectures for Hazard-Free Semi-Parallel Decoding of LDPC Codes

    Directory of Open Access Journals (Sweden)

    Rovini Massimo

    2009-01-01

    Full Text Available The layered decoding algorithm has recently been proposed as an efficient means for the decoding of low-density parity-check (LDPC codes, thanks to the remarkable improvement in the convergence speed (2x of the decoding process. However, pipelined semi-parallel decoders suffer from violations or "hazards" between consecutive updates, which not only violate the layered principle but also enforce the loops in the code, thus spoiling the error correction performance. This paper describes three different techniques to properly reschedule the decoding updates, based on the careful insertion of "idle" cycles, to prevent the hazards of the pipeline mechanism. Also, different semi-parallel architectures of a layered LDPC decoder suitable for use with such techniques are analyzed. Then, taking the LDPC codes for the wireless local area network (IEEE 802.11n as a case study, a detailed analysis of the performance attained with the proposed techniques and architectures is reported, and results of the logic synthesis on a 65 nm low-power CMOS technology are shown.

  12. Complexity Analysis of Reed-Solomon Decoding over GF without Using Syndromes

    Directory of Open Access Journals (Sweden)

    Chen Ning

    2008-01-01

    Full Text Available Abstract There has been renewed interest in decoding Reed-Solomon (RS codes without using syndromes recently. In this paper, we investigate the complexity of syndromeless decoding, and compare it to that of syndrome-based decoding. Aiming to provide guidelines to practical applications, our complexity analysis focuses on RS codes over characteristic-2 fields, for which some multiplicative FFT techniques are not applicable. Due to moderate block lengths of RS codes in practice, our analysis is complete, without big notation. In addition to fast implementation using additive FFT techniques, we also consider direct implementation, which is still relevant for RS codes with moderate lengths. For high-rate RS codes, when compared to syndrome-based decoding algorithms, not only syndromeless decoding algorithms require more field operations regardless of implementation, but also decoder architectures based on their direct implementations have higher hardware costs and lower throughput. We also derive tighter bounds on the complexities of fast polynomial multiplications based on Cantor's approach and the fast extended Euclidean algorithm.

  13. Adaptive decoding using local field potentials in a brain-machine interface.

    Science.gov (United States)

    Rosa So; Libedinsky, Camilo; Kai Keng Ang; Wee Chiek Clement Lim; Kyaw Kyar Toe; Cuntai Guan

    2016-08-01

    Brain-machine interface (BMI) systems have the potential to restore function to people who suffer from paralysis due to a spinal cord injury. However, in order to achieve long-term use, BMI systems have to overcome two challenges - signal degeneration over time, and non-stationarity of signals. Effects of loss in spike signals over time can be mitigated by using local field potential (LFP) signals for decoding, and a solution to address the signal non-stationarity is to use adaptive methods for periodic recalibration of the decoding model. We implemented a BMI system in a nonhuman primate model that allows brain-controlled movement of a robotic platform. Using this system, we showed that LFP signals alone can be used for decoding in a closed-loop brain-controlled BMI. Further, we performed offline analysis to assess the potential implementation of an adaptive decoding method that does not presume knowledge of the target location. Our results show that with periodic signal and channel selection adaptation, decoding accuracy using LFP alone can be improved by between 5-50%. These results demonstrate the feasibility of implementing unsupervised adaptive methods during asynchronous decoding of LFP signals for long-term usage in a BMI system.

  14. Divide & Concur and Difference-Map BP Decoders for LDPC Codes

    CERN Document Server

    Yedidia, Jonathan S; Draper, Stark C

    2010-01-01

    The "Divide and Concur'' (DC) algorithm, recently introduced by Gravel and Elser, can be considered a competitor to the belief propagation (BP) algorithm, in that both algorithms can be applied to a wide variety of constraint satisfaction, optimization, and probabilistic inference problems. We show that DC can be interpreted as a message-passing algorithm on a constraint graph, which helps make the comparison with BP more clear. The "difference-map'' dynamics of the DC algorithm enables it to avoid "traps'' which may be related to the "trapping sets'' or "pseudo-codewords'' that plague BP decoders of low-density parity check (LDPC) codes in the error-floor regime. We investigate two decoders for low-density parity-check (LDPC) codes based on these ideas. The first decoder is based directly on DC, while the second decoder borrows the important "difference-map'' concept from the DC algorithm and translates it into a BP-like decoder. We show that this "difference-map belief propagation'' (DMBP) decoder has drama...

  15. Complexity Analysis of Reed-Solomon Decoding over GF(2m without Using Syndromes

    Directory of Open Access Journals (Sweden)

    Zhiyuan Yan

    2008-06-01

    Full Text Available There has been renewed interest in decoding Reed-Solomon (RS codes without using syndromes recently. In this paper, we investigate the complexity of syndromeless decoding, and compare it to that of syndrome-based decoding. Aiming to provide guidelines to practical applications, our complexity analysis focuses on RS codes over characteristic-2 fields, for which some multiplicative FFT techniques are not applicable. Due to moderate block lengths of RS codes in practice, our analysis is complete, without big O notation. In addition to fast implementation using additive FFT techniques, we also consider direct implementation, which is still relevant for RS codes with moderate lengths. For high-rate RS codes, when compared to syndrome-based decoding algorithms, not only syndromeless decoding algorithms require more field operations regardless of implementation, but also decoder architectures based on their direct implementations have higher hardware costs and lower throughput. We also derive tighter bounds on the complexities of fast polynomial multiplications based on Cantor's approach and the fast extended Euclidean algorithm.

  16. Overcoming Long-Term Variability in Local Field Potentials Using an Adaptive Decoder.

    Science.gov (United States)

    Tadipatri, Vijay Aditya; Tewfik, Ahmed H; Pellizzer, Giuseppe; Ashe, James

    2017-02-01

    Long-term variability remains one of the major hurdles in using intracortical recordings like local field potentials for brain computer interfaces (BCI). Practical neural decoders need to overcome time instability of neural signals to estimate subject behavior accurately and faithfully over the long term. This paper presents a novel decoder that 1) characterizes each behavioral task (i.e., different movement directions under different force conditions) with multiple neural patterns and 2) adapts to the long-term variations in neural features by identifying the stable neural patterns. This adaptation can be performed in both an unsupervised and a semisupervised learning framework requiring minimal feedback from the user. To achieve generalization over time, the proposed decoder uses redundant sparse regression models that adapt to day-to-day variations in neural patterns. While this update requires no explicit feedback from the BCI user, any feedback (explicit or derived) to the BCI improves its performance. With this adaptive decoder, we investigated the effects of long-term neural modulation especially when subjects encountered new external forces against movement. The proposed decoder predicted eight hand-movement directions with an accuracy of 95% over two weeks (when there was no external forces); and 85% in later acquisition sessions spanning up to 42 days (when the monkeys countered external field forces). Since the decoder can operate with or without manual intervention, it could alleviate user frustration associated with BCI.

  17. How Major Depressive Disorder affects the ability to decode multimodal dynamic emotional stimuli

    Directory of Open Access Journals (Sweden)

    FILOMENA SCIBELLI

    2016-09-01

    Full Text Available Most studies investigating the processing of emotions in depressed patients reported impairments in the decoding of negative emotions. However, these studies adopted static stimuli (mostly stereotypical facial expressions corresponding to basic emotions which do not reflect the way people experience emotions in everyday life. For this reason, this work proposes to investigate the decoding of emotional expressions in patients affected by Recurrent Major Depressive Disorder (RMDDs using dynamic audio/video stimuli. RMDDs’ performance is compared with the performance of patients with Adjustment Disorder with Depressed Mood (ADs and healthy (HCs subjects. The experiments involve 27 RMDDs (16 with acute depression - RMDD-A, and 11 in a compensation phase - RMDD-C, 16 ADs and 16 HCs. The ability to decode emotional expressions is assessed through an emotion recognition task based on short audio (without video, video (without audio and audio/video clips. The results show that AD patients are significantly less accurate than HCs in decoding fear, anger, happiness, surprise and sadness. RMDD-As with acute depression are significantly less accurate than HCs in decoding happiness, sadness and surprise. Finally, no significant differences were found between HCs and RMDD-Cs in a compensation phase. The different communication channels and the types of emotion play a significant role in limiting the decoding accuracy.

  18. A lossy graph model for delay reduction in generalized instantly decodable network coding

    KAUST Repository

    Douik, Ahmed S.

    2014-06-01

    The problem of minimizing the decoding delay in Generalized instantly decodable network coding (G-IDNC) for both perfect and lossy feedback scenarios is formulated as a maximum weight clique problem over the G-IDNC graph in. In this letter, we introduce a new lossy G-IDNC graph (LG-IDNC) model to further minimize the decoding delay in lossy feedback scenarios. Whereas the G-IDNC graph represents only doubtless combinable packets, the LG-IDNC graph represents also uncertain packet combinations, arising from lossy feedback events, when the expected decoding delay of XORing them among themselves or with other certain packets is lower than that expected when sending these packets separately. We compare the decoding delay performance of LG-IDNC and G-IDNC graphs through extensive simulations. Numerical results show that our new LG-IDNC graph formulation outperforms the G-IDNC graph formulation in all lossy feedback situations and achieves significant improvement in the decoding delay especially when the feedback erasure probability is higher than the packet erasure probability. © 2012 IEEE.

  19. Delay reduction in lossy intermittent feedback for generalized instantly decodable network coding

    KAUST Repository

    Douik, Ahmed S.

    2013-10-01

    In this paper, we study the effect of lossy intermittent feedback loss events on the multicast decoding delay performance of generalized instantly decodable network coding. These feedback loss events create uncertainty at the sender about the reception statues of different receivers and thus uncertainty to accurately determine subsequent instantly decodable coded packets. To solve this problem, we first identify the different possibilities of uncertain packets at the sender and their probabilities. We then derive the expression of the mean decoding delay. We formulate the Generalized Instantly Decodable Network Coding (G-IDNC) minimum decoding delay problem as a maximum weight clique problem. Since finding the optimal solution is NP-hard, we design a variant of the algorithm employed in [1]. Our algorithm is compared to the two blind graph update proposed in [2] through extensive simulations. Results show that our algorithm outperforms the blind approaches in all the situations and achieves a tolerable degradation, against the perfect feedback, for large feedback loss period. © 2013 IEEE.

  20. Decoding brain activity using a large-scale probabilistic functional-anatomical atlas of human cognition.

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    Timothy N Rubin

    2017-10-01

    Full Text Available A central goal of cognitive neuroscience is to decode human brain activity-that is, to infer mental processes from observed patterns of whole-brain activation. Previous decoding efforts have focused on classifying brain activity into a small set of discrete cognitive states. To attain maximal utility, a decoding framework must be open-ended, systematic, and context-sensitive-that is, capable of interpreting numerous brain states, presented in arbitrary combinations, in light of prior information. Here we take steps towards this objective by introducing a probabilistic decoding framework based on a novel topic model-Generalized Correspondence Latent Dirichlet Allocation-that learns latent topics from a database of over 11,000 published fMRI studies. The model produces highly interpretable, spatially-circumscribed topics that enable flexible decoding of whole-brain images. Importantly, the Bayesian nature of the model allows one to "seed" decoder priors with arbitrary images and text-enabling researchers, for the first time, to generate quantitative, context-sensitive interpretations of whole-brain patterns of brain activity.