Conventional Codes Research Articles

Downburst related damages in Brazilian buildings: Are they avoidable?

Brazil's territory has shown an enormous potential to generate severe weather and intensive downbursts cases gained attention as a result of the severe destructive patterns not frequently seen before. However, several of the downburst damages on Brazilian buildings and structures follow a similar pattern than those caused by synoptic winds. The significant amount of accidents due to extreme winds in the recent years suggests the need for a review of the Brazilian Wind Code as well as the necessity to reinforce its use in common day buildings design. The new version of the code should incorporate an update of climate data and implement a thunderstorm wind model. This paper brings an overview of the downburst areas with major risk of occurrences, as well as presents an analysis of the damage patterns caused by the downbursts, with special focus on the effects on buildings and structures. It is concluded that, although the flow characteristics of downburst winds and conventional boundary layer simulations of synoptic winds may differ, the use of current conventional wind tunnel simulations and conventional code values are still a valuable tool in the prevention of wind related damages, at least in low and medium-rise buildings.

Terminated Staircase Codes for NAND Flash Memories

In this paper, we propose novel terminated staircase codes for NAND flash memories. Specifically, we design a rate 0.89 staircase code whose component code is a Bose–Chaudhuri–Hocquenghem (BCH) code, for flash memories with page size of 16K bytes. Different from most conventional unterminated staircase codes, we propose a novel coding structure by performing cyclic redundancy check (CRC) encoding and decoding on each component codeword including information bits and parity bits. The CRC bits are protected by both row and column codewords. Furthermore, a novel iterative bit flipping algorithm is developed to solve stall patterns and lower the error floor. Based on our design, we perform an improved analysis on the error floor. We prove and show that our proposed decoding algorithm can solve more stall patterns which leads to a lower error floor compared with conventional staircase codes. Numerical results show that our terminated staircase codes outperform the stand-alone BCH codes and the conventional staircase codes.

Mushroom skeleton to create rocking motion in low-rise steel buildings to improve their seismic performance

Rocking motion have been used for achieving the \'resilient buildings\' against earthquakes in recent studies. Lowrise buildings, unlike the tall ones, because of their small aspect ratio tend to slide rather than move in rocking mode. However, since rocking is more effective in seismic response reduction than sliding, it is desired to create rocking motion in low-rise buildings too. One way for this purpose is making the building\'s structure rock on its internal bay(s) by reducing the number of bays at the lower part of the building\'s skeleton, giving it a mushroom form. In this study \'mushroom skeleton\' has been used for creating multi-story rocking regular steel buildings with square plan to rock on its one-by-one bay central lowest story. To show if this idea is effective, a set of mushroom buildings have been considered, and their seismic responses have been compared with those of their conventional counterparts, designed based on a conventional code. Also, a set of similar buildings with skeleton stronger than code requirement, to have immediate occupancy (IO) performance level, have been considered for comparison. Seismic responses, obtained by nonlinear time history analyses, using scaled three-dimensional accelerograms of selected earthquakes, show that by using appropriate \'mushroom skeleton\' the seismic performance of buildings is upgraded to mostly IO level, while all of the conventional buildings experience collapse prevention (CP) level or beyond. The strong-skeleton buildings mostly present IO performance level as well, however, their base shear and absolute acceleration responses are much higher than the mushroom buildings.

Performance Analysis and Improvement of Online Fountain Codes

The online property of fountain codes enables the encoder to efficiently find the optimal encoding strategy that minimizes the encoding overhead based on the instantaneous decoding state. Therefore, the receiver is able to optimally recover data from losses that differ significantly from the initial expectation. In this paper, we propose a framework to analyze the relationship between overhead and the number of recovered source symbols for online fountain codes based on random graph theory. Motivated by the analysis, we propose improved online fountain codes (IOFCs) by introducing a designated selection of source symbols. Theoretical analysis shows that IOFC has lower overhead compared with the conventional online fountain codes. We verify the proposed analysis via simulation results and demonstrate the tradeoff between full recovery and intermediate performance in comparison to other online fountain codes.

A Novel Video Coding Framework Using a Self-Adaptive Dictionary

In this paper, we propose to use a self-adaptive redundant dictionary, consisting of all possible inter and intra prediction candidates, to directly represent the frame blocks in a video sequence. The self-adaptive dictionary generalizes the conventional predictive coding approach by allowing adaptive linear combinations of prediction candidates, which is solved by an rate-distortion aware L0-norm minimization problem using orthogonal least squares (OLS). To overcome the inefficiency in quantizing and coding coefficients corresponding to correlated chosen atoms, we orthonormalize the chosen atoms recursively as part of OLS process. We further propose a two-stage video coding framework, in which a second stage codes the residual from the chosen atoms using a modified discrete cosine transform (DCT) dictionary that is adaptively orthonormalized with respect to the subspace spanned by the first stage atoms. To determine the transition from the first stage to the second stage, we propose a rate-distortion (RD) aware adaptive switching algorithm. The proposed framework is further extended to accommodate variable block sizes ( $16\times 16$ , $8\times 8$ , and $4\times 4$ ), and the partition mode is derived by a fast partition mode decision algorithm. A context-adaptive binary arithmetic entropy coder is designed to code the symbols of the proposed coding framework. The proposed coder shows competitive, and in some cases better RD performance, compared with the HEVC video coding standard for P-frames.

Improvement of Risk Assessment Using Numerical Analysis for an Offshore Plant Dipole Antenna

This paper proposes a numerical analysis method for improving risk assessment of radio frequency (RF) hazards. To compare the results of conventional code analysis, the values required for dipole antenna risk assessment, which is widely used in offshore plants based on the British standards (BS) guide, are calculated using the proposed numerical analysis. Based on the BS (published document CENELEC technical report (PD CLC/TR) 50427:2004 and international electrotechnical commission (IEC) 60079 for an offshore plant dipole antenna, an initial assessment, a full assessment, and on-site test procedures are performed to determine if there is a potential risk of high-frequency ignition. Alternatively, numerical analysis is performed using the Ansys high frequency structure simulator (HFSS) tool to compare results based on the BS guide. The proposed method computes the effective field strength and power for the antenna without any special consideration of the structure to simplify the calculation. Experimental results show that the proposed numerical analysis outperforms the risk assessment based on the BS guide in accuracy of the evaluation.

Modeling thin structures incorporated with surface effects by using layered shell elements

We demonstrate that layered shell elements in existing conventional finite element codes can be directly used for modeling thin structures with surface effects. Based on a recently published methodology for modeling a solid structure incorporated with surface effects by using both solid type and shell type elements, we propose that for thin structures, one type of element - layered shell type element is sufficient for incorporating surface effects. The results calculated from the proposed finite element method for simply supported plates agree with theoretical predictions. The surface effects on kirigami of a soft sheet are presented as an example application of the proposed method.

Proactive correction coset decoding scheme based on SEC-DED code for multibit asymmetric errors in STT-MRAM

As one promising candidate of next generation nonvolatile memory technologies, spin-transfer torque random access memory (STT-MRAM) offers many attractive characteristics, such as high speed, nonvolatility, high integration density, and excellent CMOS process compatibility. However, the performance and reliability of STT-RAM cells are greatly affected by device operating uncertainties and external circuit variation. As a result, write operations of STT-MRAM are not identical, which introduces asymmetric write failure rates for 0→1 and 1→0 bit flipping. Error correcting codes (ECCs) are general solutions for protecting memories from errors. The ECCs most widely used in memory technology are the single error correction and double error detection (SEC-DED) codes. Unfortunately, existing SEC-DED code schemes have limited correction capabilities and do not take the different error rates of memories into consideration. Regarding the failure characteristics (e.g., multibit and asymmetric) of STT-MRAM, conventional SEC-DED codes are not efficiently applicable. In this paper, we propose a proactive correction coset decoding scheme to correct double asymmetric errors for STT-MRAM. The scheme is partitioned into two levels: the proactive correction level (PCL) and the asymmetric correction level (ACL). The PCL proactively handles the single-bit error correction and the ACL analyzes the result from the prior level and corrects the second error. These levels are all based on the same standard coset array. Finally, simulation results with an SEC-DED code show the effectiveness and improvement of the proposed decoding scheme.

P4 - Targetable Reactive Electrophiles and Oxidants (T-REX) Technology to Identify "Privileged" Redox Sensors

Precisely timed and spatially regulated electrophilic chemical signals are the essence of biochemical redox signaling. However, defining the precise biological impacts of localized signals that engage with specific protein targets at low occupancy and under physiologic conditions has proven to be highly challenging. This talk presents a unique set of proximity-directed chemical biology tools that enables interrogation into functional consequences of specific redox-linked events through T-REX™ precision electrophile delivery and G-REX™ profiling in living systems (Nature Protocols 2016; Nature Chemical Biology 2017; Cell Chemical Biology 2017; ACS Central Science 2018). With these in vivo-validated technologies, we identify bona fide "privileged first responders" that interact with native signaling electrophiles under electrophile-limited (true kcat/Km) conditions. Our data illuminate these first responders as novel signaling nodes, interchanging electrophile and conventional signaling codes such as phosphate and ubiquitin for decision making at organismal level. Our unique chemical biology toolset sets the stage for ruling in gain-of-function (or dominant loss-of-function) electrophilic modifications and relating them to phenotype in an unbiased experiment that is not hampered by functional redundancy. With the growing importance of covalent drugs in the treatment of various human disorders, our new ability to discover and functionally decipher precision electrophile signaling mechanisms opens new avenues toward targeted therapeutics and novel target discovery.

Gain Error Calibrations for Two-Step ADCs: Optimizations Either in Accuracy or Chip Area

This paper presents two calibration schemes to correct the stage gain error in analog-to-digital converters. The two approaches target different scenarios, either better calibration accuracy or less digital overhead. First, we optimize the gain calculation scheme in the conventional code statistics-based approach, which improves the calibration accuracy. Moreover, we introduce a missing-code-detected calibration that replaces the calculation of the gain coefficient by counting and multiplying the number of missing codes in the digital domain, which significantly simplifies the digital implementation. To eliminate the calibration dependence on the input signal, we implement a testing signal generation on-chip. We also compare these calibration schemes with the requirements of the input signal, the calibration accuracy, as well as the hardware overhead based on a mathematical model with behavior simulations. Both concepts were verified in an 11-bit 80-MS/s successive approximation register with a bridge digital-to-analog converter fabricated in a 65-nm CMOS.

Verification and validation of STREAM/RAST-K for PWR analysis

Abstract This paper presents the verification and validation (V&V) of the STREAM/RAST-K 2.0 code system for a pressurized water reactor (PWR) analysis. A lattice physics code STREAM and a nodal diffusion code RAST-K 2.0 have been developed by a computational reactor physics and experiment laboratory (CORE) of Ulsan National Institute of Science and Technology (UNIST) for an accurate two-step PWR analysis. The calculation modules of each code were already verified against various benchmark problems, whereas this paper focuses on the V&V of linked code system. Three PWR type reactor cores, OPR-1000, three-loop Westinghouse reactor core, and APR-1400, are selected as V&V target plants. This code system, for verification, is compared against the conventional code systems used for the calculations in nuclear design reports (NDRs) and validated against measured plant data. Compared parameters are as follows: critical boron concentration (CBC), axial shape index (ASI), assembly-wise power distribution, burnup distribution and peaking factors. STREAM/RAST-K 2.0 shows the RMS error of critical boron concentration within 20 ppm, and the RMS error of assembly power within 1.34% for all the cycles of all reactors.

Efficient Real-Time Coding-Assisted Heterogeneous Data Access in Vehicular Networks

Through the embedded processors and communication technologies, vehicles are increasingly being connected with the Internet of Things. Recently, much attentions have been paid to network-coding-assisted data broadcast in vehicular networks. However, majority of the works consider all the accessed data items are the same size. In this paper, we have studied the network coding-assisted heterogeneous on-demand real-time data access in vehicular networks. First, we have investigated the less efficiency of conventional coding assisted approach in accessing heterogeneous data items in real-time vehicular environment. Due to ignoring the impact of heterogeneous data items in decoding, the conventional coding does not achieve expected performance in accessing data items with diverse size. Second, based on our observations, for efficiently serving heterogeneous data items, we have proposed a dynamic threshold-based coding-assisted real-time data broadcast approach called earliest deadline first <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Θ</sub> . Third, we have derived the probabilistic analysis of the system performance of the proposed approach and the state-of-the-art approaches. Fourth, based on our further investigations, we have proposed another approach, called inverse of slack time multiply distance with THRESHOLD (Θ) (ISXD <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Θ</sub> ). The proposed network coding-assisted ISXD <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Θ</sub> exploits the different modulation and coding scheme of IEEE 802.11p physical layer for leveraging the variable serving rate considering the dynamic positions of vehicles along with the vehicle mobility. The comprehensive simulation results demonstrate the efficacy of the proposed approaches over the state-of-the-art approaches in terms of improving the on-demand requests serving capability and reducing the system response time.

Optimization of space-charge dominated injection beam line of high current proton RFQ

Design of a space charge dominated proton beam-line from an ECR ion source to a high current RFQ has been carried out using analytical formulation. The parameters of the beam-line consisting of two solenoids, a slit for selecting H+ and rejecting H2+, and buncher are optimized to match the proton beam with the acceptance of RFQ . Analytical formulation for multispecies beam instead of conventional optical code has helped in simultaneously achieving different objectives within a compact but optimum length. Disc model having finite input energy width for longitudinal calculations and K-V transverse envelope equations for individual macro-discs including the bunching effect has been used. Selected parameters have been further corroborated by particle tracking using the 3D field of buncher and RFQ . Efficient selection/rejection of species has been verified with different type of input particle distributions in particle tracking. Finally the transmitted H+ and remaining H2+ has been tracked through the RFQ . The ratio of H+ to H2+, which is roughly 7:3 at exit of ECRIS could be reduced to 32:1 after the slit, while through RFQ remaining H2+ gets only transmitted but without any acceleration.

Unwitting Inventors: Speakers Use -ly-Adverbs More Creatively when Primed

Abstract Speakers may use language creatively because they want to be extravagant, or because they need to communicate content for which no conventional coding solution exists. In addition, however, there is a third motivation for creativity that is both more fundamental and less conspicuous. Speakers are creative because their mental access to linguistic resources is limited and variable – a factor referred to here as ‘availability.’ In this paper, corpus data from the spoken British National Corpus and from the Hansard Corpus are used to show that speakers of English use the morphological pattern of -ly-adverb formation (as in correctly, locally, poorly etc.) more creatively when they have recently heard or used another -ly-adverb. This manifests itself in higher type frequencies – hence, more varied forms – for -ly-adverbs. The effect can be ascribed to priming, and indicates that the creative use of a linguistic resource depends on factors that facilitate mental access to it.

An investigation of P-delta effect in conventional seismic design and direct displacement-based design using elasto-plastic SDOF systems

The seismic responses of structures are always influenced by P-Δ effects. The significance of this effect may be negligible when the structure responds elastically but is very important when the structure responds into inelastic range. The P-Δ effect usually increases the displacement response of structures. It may even cause dynamic instability when the structure subjected to severe earthquake ground motions. In conventional seismic design codes, the P-Δ effect usually leads to an increase in design base shear. The same approach is used in direct displacement-based design. Various researchers have proposed different relationships for base shear increase which can be used in different seismic design approaches such as force-based design and performance-based design. In this paper, the proposed expressions are reviewed extensively and their adequacy is evaluated by detail. Then two main purposes are pursued: (1) the development of new expressions for strength amplification factor due to P-Δ effect for current force-based design seismic codes; and (2) the modification of equivalent viscous damping or the required additional base shear considering the P-Δ effect in direct displacement-based design procedure. For this purpose, a new algorithm based upon elasto-plastic SDOF system analyses is presented. The algorithm is implemented 102,500 times overall for different periods, ductility levels, stability indices and different earthquake ground motions that each implementation needs a large amount of trial and error process in linear and nonlinear SDOF systems. The results seem to present a good development of the P-Δ effect relations for the seismic design procedures.

Accurate Modelling and Efficient Estimation of the Print-Capture Channel with Application in Barcoding.

With the rapid advancement of sensing capability and computational power in consumer electronic devices, the use of mobile cameras for communications has attracted significant attention from both academia and industry. The design of a reliable communication system over the print-capture channel is a key challenge in some important applications, such as barcoding and document authentication. However, the real-world printcapture channel is spatially non-linear and non-stationary, and lacks a standard parametric model. As a consequence, advanced channel coding techniques developed for common channel models are not applicable in the existing systems without costly and device-dependent pre-training. In this work, an accurate parametric print-capture channel model and an efficient channel estimation scheme requiring low training overhead are proposed. With the estimated parameters, the proposed print-capture channel model can be linearized to the (possibly input-dependent) additive white Gaussian noise (AWGN) channel model. This allows the use of state-of-the-art channel coding schemes, such as low-density parity-check (LDPC) codes with iterative soft decoding, to improve the reliability of the communication system under challenging conditions, e.g., at a low signal-to-noise ratio. As an example application of the proposed print-capture channel model, a demonstrative multilevel 2D barcode using an LDPC code with iterative soft decoding, is designed to enhance the reliability over the conventional QR code which is based on the Reed-Solomon code with hard decoding. At a printing resolution of 600dpi, the 8-level 2D barcode achieves data capacity gains of about 10% and 56% over the QR code in the in-focus and blurlimited scenarios, respectively. It is noteworthy that the enhanced data capacity of the multilevel barcode is made possible by the proposed channel estimation scheme, which incurs an additional training overhead of about 3.3% only.

Design of Quantum LDPC Codes From Quadratic Residue Sets

We design classes of quantum low-density parity-check (LDPC) codes, called quasi-cyclic stabilizer (QCS) codes, from conventional QC-LDPC codes. The proposed QCS codes belong to the family of non-Calderbank–Shor–Steane stabilizer codes. The QC-LDPC codes are self-orthogonal with respect to the symplectic inner product (SIP) and are constructed from submatrices of nonorthogonal Latin squares via array dispersion. The Latin squares are constructed using quadratic (non)-residue sets of prime modulus $p$ , where $p = 4n\pm 1$ . For $p = 4n-1$ , two constructions, namely, Type-I-A and Type-I-B QCS codes, are proposed based on matrix superposition and matrix concatenation, respectively. For $p = 4n+1$ , Type-II QCS codes are proposed based on permutations of a base matrix. We show that the parity-check matrix for Type-I-B and Type-II QCS codes is self-orthogonal with respect to the SIP for all orders of circulant permutation matrix. This resulting in ensembles of QCS codes characterized by a single base matrix. We show that the minimum distance of Type-II QCS codes can be lower bounded by the minimum distance of the QC-LDPC codes. Simulation results show that the proposed QCS codes outperform some codes in the literature with a noteworthy low-error floor, below 10−7, over quantum depolarizing channels.

High-Capacity Upconversion Wavelength and Lifetime Binary Encoding for Multiplexed Biodetection.

Optical multiplexing plays an important role in fields ranging from advanced biological assays to security. However, conventional codes based on fluorescent color and intensity are limited to spectral overlap and background interference. Herein, we present a new multiplexing concept by manipulating the luminescence emission color and decay lifetimes of upconversion nanoparticles (τλ -UCNPs) separately for the first time through designing the core/multi-shell structure and controlled energy relay method. This new color/lifetime binary strategy exhibits exponentially scalable encoding capacity (>105 ), three orders of magnitudes higher than that of conventional color/intensity way. The strategy enables the multiplexed detection of human papilloma virus (HPV) subtypes in patient samples and robust anti-counterfeiting. This work opens new opportunities for optical multiplexing with luminescent materials.

High‐Capacity Upconversion Wavelength and Lifetime Binary Encoding for Multiplexed Biodetection

AbstractOptical multiplexing plays an important role in fields ranging from advanced biological assays to security. However, conventional codes based on fluorescent color and intensity are limited to spectral overlap and background interference. Herein, we present a new multiplexing concept by manipulating the luminescence emission color and decay lifetimes of upconversion nanoparticles (τλ‐UCNPs) separately for the first time through designing the core/multi‐shell structure and controlled energy relay method. This new color/lifetime binary strategy exhibits exponentially scalable encoding capacity (&gt;105), three orders of magnitudes higher than that of conventional color/intensity way. The strategy enables the multiplexed detection of human papilloma virus (HPV) subtypes in patient samples and robust anti‐counterfeiting. This work opens new opportunities for optical multiplexing with luminescent materials.

Application of Biphase Complete Complementary Code for Ionospheric Sounding.

This paper illustrates the processes carried out for the application of biphase complete complementary code (CCC) for ionospheric sounding to address the coherent interference problem in multi-station ionospheric sounding. An algorithm to generate the biphase CCC is described, and the detailed process of waveform construction and signal processing is presented. Characteristics of the autocorrelation and cross-correlation are analyzed through simulations, and the technical feasibility of the application of CCC is explored. Experiments of ionospheric sounding with the CCC are also implemented to verify performance. Results demonstrate that the CCC performs well in multi-station ionospheric sounding, and is capable of eliminating the coherent interference in the network of ionosondes, compared to the conventional complementary code.