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1
Raković, Lazar, Milutinović Đorđević, Paweł Lula, Vuk Vuković, Marek Dziura, and Tomasz Rojek. "Low code/no code software development: Definition, drivers, and inhibitors." Anali Ekonomskog fakulteta u Subotici, no. 00 (2025): 57. https://doi.org/10.5937/aneksub2500007r.
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Purpose: Low Code and No Code refer to software development by end users with little or no IT background. The goal of the manuscript is to define this concept, as well as identify the drivers on one hand, and the limitations, challenges, and inhibitors on the other. Methodology: In order to answer the previously posed research questions, a systematic literature review was conducted. The systematic review of the literature included three main steps: planning the review, conducting the review, and writing the report. Findings: The paper presents various definitions of the LowCode/NoCode concept, as well as one general definition. It then lists the key drivers that lead to the increasing use of this concept in organizations. After that, the limitations, challenges, and inhibitors of Low Code/No Code software development are presented. Originality/value: The paper provides a clear and systematic review of the LowCode/NoCode concepts in relation to three dimensions (definition, drivers, and limitations/challenges/inhibitors). Practical implications - The results presented in the paper can be useful for both IT departments and business units as a starting point for establishing and managing LowCode/NoCode practices within an organization. Limitations: The systematic literature review included papers published in two citation databases and in English. Future research directions would focus on the empirical validation of specific drivers and limitations, challenges, and inhibitors from both business and IT users' perspectives.
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Barletta, Luca, and Arnaldo Spalvieri. "Design of Short, High-Rate DVB-S2-Like Semi-Regular LDPC Codes." Research Letters in Communications 2008 (2008): 1–4. http://dx.doi.org/10.1155/2008/324503.
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This work focuses on high-rate () moderate-length () low-density parity-check codes. High-rate codes allow to maintain good quality of the preliminary decisions that are used in carrier recovery, while a moderate code length allows to keep the latency low. The interleaver of the LDPC matrix that we consider is inspired to the DVB-S2 standard one. A novel approach for avoiding short cycles is analyzed. A modified BP decoding algorithm is applied in order to deal with longer cycles. Simulations and results for the AWGN channel are presented, both for BPSK signalling and for coded modulation based on the partition .
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Ovchinnikov, Andrei A., and Anna A. Fominykh. "Analysis and optimization of error-correcting coding schemes for channels with Rayleigh fading." H&ES Research 15, no. 3 (2023): 47–56. http://dx.doi.org/10.36724/2409-5419-2023-15-3-47-56.
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Conventional approach to perform error-correcting decoding in channels with memory is an adoption of interleaving, which increases the receiver complexity and delay. In order to avoid these limitations, approaches for adapting an error-correcting scheme for memory channels may be used. One approach is to use error-correcting codes with modified design and decoding procedure, taking into account the presence of error bursts in the channel. Another approach to adapting the coding scheme for burst error correction is to use product codes with iterative decoding algorithms. Component codes of product codes themselves may not be able to correct error bursts, but a two-dimensional structure of product codes operating as an artificial interleaver and iterative decoding allow for correction of grouping errors. Purpose: The purpose of the study is to analyze the methods of error-correcting code adaptation to burst error correction in channels with memory in order to reduce the probability of error. Results: The study considered methods of error-correcting code scheme adaptation for low-density parity-check codes, polar codes, and product codes for burst error correction in Gilbert-Elliott channel (GE) and correlated Rayleigh fading channel with different correlation coefficients. Degree distribution of low-density parity-check code was optimized for GE channel. The influence of selected parameters of product code component codes on burst error correction in the GE channel was analyzed. The structure of the polar code has been optimized using a genetic algorithm for the correlated Rayleigh channel, which outperforms the 5G polar code design in terms of error probability. Discussion: Existing error-correcting code schemes do not provide theoretically possible limits, so the question remains of developing coding and decoding schemes capable of reaching theoretical limits.
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Shu, Bingxin, Jing Lei, Xinjin Lu, and Jianghua Cheng. "Adaptive transmission construction based on polar codes." Journal of Physics: Conference Series 2497, no. 1 (2023): 012012. http://dx.doi.org/10.1088/1742-6596/2497/1/012012.
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Abstract In actual communication scenarios, wireless transmission channels have the nature of heterogeneity. In order to ensure that data can be transmitted with high reliability and low delay, this paper designs a quasi-optimal polar code that can adapt to various channel environments, which called Q-polar code. Based on the polarization theory of polar codes and the channel state information (CSI), the index set of polar codes is designed and constructed to perform data transmission tasks. The simulation results show that the bit error rate (BER) performance of proposed scheme can be improved compared with traditional polar code, especially when the code length N is small and the code rate is large.
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Serwa, Kamila. "Low-Code/No-Code zur Darstellung von Produktionsdaten über die Asset Administration Shell." Zeitschrift für wirtschaftlichen Fabrikbetrieb 119, no. 5 (2024): 378–84. http://dx.doi.org/10.1515/zwf-2024-1057.
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Abstract In order to drive digital transformation in manufacturing companies, low-code/no-code offers an alternative approach to software development. The technical article shows the functionality and application of the low-code/ no-code method in production in combination with the Digital Twin and the Asset Administration Shell. Using the open source platform „Saltcorn“, it is described how a dashboard for visualizing production data can be implemented in the form of a web application using low-code/ no-code without any programming knowledge. Companies can use dashboards to analyze their production data, for example to make decisions to optimize production.
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Belhadj, Salima, Abdelmounaim Moulay Lakhdar, and Ridha Ilyas Bendjillali. "Performance comparison of channel coding schemes for 5G massive machine type communications." Indonesian Journal of Electrical Engineering and Computer Science 22, no. 2 (2021): 902–8. https://doi.org/10.11591/ijeecs.v22.i2.pp902-908.
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Channel coding for the fifth generation (5G) mobile communication is currently facing new challenges as it needs to uphold diverse emerging applications and scenarios. Massive machine-type communication (mMTC) constitute one of the main usage scenarios in 5G systems, which promise to provide low data rate services to a large number of low power and low complexity devices. Research on efficient coding schemes for such use case is still ongoing and no decision has been made yet. Therefore, This paper compares the performance of different coding schemes, namely: tail-biting convolutional code (TBCC), low density parity check codes (LDPC), Turbo code and Polar codes, in order to select the appropriate channel coding technique for 5G-mMTC scenario. The considered codes are evaluated in terms of bit error rate (BER) and block error rate (BLER) for short information block lengths (K ≤ 256). We further investigate their Algorithmic complexity in terms of the number of basic operations. The Simulation results indicate that polar code with CRC-aided successive cancelation list decoder has better performance compared with other coding schemes for 5G-mMTC scenario.
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Gunadi, Gagah Aji, and Dana Sulistyo Kusumo. "COMPARISON OF MNOTE APPLICATION DEVELOPMENT EFFICIENCY USING LOW CODE AND FULL CODE DEVELOPMENT APPROACHES." Jurnal Teknik Informatika (Jutif) 5, no. 2 (2024): 645–51. https://doi.org/10.52436/1.jutif.2024.5.2.1728.
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Low Code Development has become more popular in recent years as it offers the ability to develop applications faster. Before the concept of Low Code programming, problems related to the efficiency of application development time were often faced when using manual or Full Code programming approaches. The problem becomes crucial when working on a large-scale application development scope. In this research, the author tries to measure and compare the difference in development efficiency between Low Code and Full Code approaches in the development of a web-based application called MNote, an order recording application for D'Happy food and beverage restaurant in Pemalang, Central Java. The author used OutSystems as the Low Code Platform (LCP) and MongoDB, ExpressJS, ReactJS, NodeJS (MERN) in the Full Code approach. The results showed that the Low Code Development approach takes 51.12% faster than the Full Code Development approach in developing the MNote application. Based on the results of the research, it can be concluded that the use of Low Code Development has a considerable influence in terms of time efficiency and ease of database integration.
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Shridhar, Shreyas. "Analysis of Low Code-No Code Development Platforms in comparison with Traditional Development Methodologies." International Journal for Research in Applied Science and Engineering Technology 9, no. 12 (2021): 508–13. http://dx.doi.org/10.22214/ijraset.2021.39328.
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Abstract: This paper examines the overview of low-code/no-code development platforms in comparison with traditional development methodologies and examines the benefits and limitations of the same. For several decades, businesses have had multiple options when they demanded new information systems. They could develop a new system using in-house developers, or they could order a system from an external merchant. This offers a close fit to business obligations. However, nowadays, there is a new alternative that is becoming increasingly prevalent. Low code/no code (LC/NC) applications can cater to business requirements efficiently, can be implemented instantly, and the cost is much less than systems developed in-house. Few, if any, programming skills are required. Keywords: Traditional development, No code development, low code development, Low code No code development, Software development life cycle (SDLC)
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Văduva, Bogdan, and Honoriu Vălean. "Designing a Low-Code CRUD framework." Carpathian Journal of Electronic and Computer Engineering 14, no. 1 (2021): 11–19. http://dx.doi.org/10.2478/cjece-2021-0003.
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Abstract Nowadays programmers write source code for inserting, editing and deleting records of a relational table. The majority of commercial relational databases include a specific management tool that offers such possibilities and most database programmers take this ability as granted. When it comes to real life applications, programmers use Object Oriented (OO) paradigm to build user friendly windows/screens/forms for database operations. The current work shows a different approach using a Low-code CRUD (Create, Read, Update, Delete) framework. Views and guidelines of how to design a Low-code CRUD framework will be detailed. “Low-code” motivation is due to the fact that the new framework will provide the ability to use less code in order to build fast and efficient complex applications. It will be up to the reader to envision a specific framework.
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Belhadj, Salima, Abdelmounaim Moulay Lakhdar, and Ridha Ilyas Bendjillali. "Performance comparison of channel coding schemes for 5G massive machine type communications." Indonesian Journal of Electrical Engineering and Computer Science 22, no. 2 (2021): 902. http://dx.doi.org/10.11591/ijeecs.v22.i2.pp902-908.
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<p><span>Channel coding for the fifth generation (5G) mobile communication is currently facing new challenges as it needs to uphold diverse emerging applications and scenarios. Massive machine-type communication (mMTC) constitute one of the main usage scenarios in 5G systems, which promise to provide low data rate services to a large number of low power and low complexity devices. Research on efficient coding schemes for such use case is still ongoing and no decision has been made yet. Therefore, This paper compares the performance of different coding schemes, namely: tail-biting convolutional code (TBCC), low density parity check codes (LDPC), Turbo code and Polar codes, in order to select the appropriate channel coding technique for 5G-mMTC scenario. The considered codes are evaluated in terms of bit error rate (BER) and block error rate (BLER) for short information block lengths (K ≤ 256). We further investigate their Algorithmic complexity in terms of the number of basic operations. The Simulation results indicate that polar code with CRC-aided successive cancelation list decoder has better performance compared with other coding schemes for 5G-mMTC scenario.</span></p>
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Schmidt, K. U. "On cosets of the generalized first-order reed-muller code with low PMEPR." IEEE Transactions on Information Theory 52, no. 7 (2006): 3220–32. http://dx.doi.org/10.1109/tit.2006.876252.
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Ke, Jing, Xiaochun Lu, Xue Wang, Xiaofei Chen, and Sheng Tang. "Concatenated Coding for GNSS Signals in Urban Environments." Applied Sciences 10, no. 18 (2020): 6397. http://dx.doi.org/10.3390/app10186397.
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This work investigated concatenated coding schemes for Global Navigation Satellite System (GNSS) signals in order to increase their error correction capability in urban environments. In particular, a serial concatenated code that combines an outer Reed–Solomon (RS) code with an inner low-density parity-check (LDPC) code was designed, and the performance was investigated over the land mobile satellite (LMS) channel for characterizing multipath and shadow fading in urban environments. The performance of the proposed concatenated coding scheme was compared to that of a B-CNAV1 message, in which two interleaved 64-ary LDPC codes were employed. The simulation results demonstrate that the proposed concatenated code can obtain a similar error correction performance to the two interleaved 64-ary LDPC codes in both the additive white Gaussian noise (AWGN) and LMS channels at a lower complexity level.
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Haah, Jeongwan, and Matthew B. Hastings. "Codes and Protocols for Distilling T, controlled-S, and Toffoli Gates." Quantum 2 (June 7, 2018): 71. http://dx.doi.org/10.22331/q-2018-06-07-71.
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We present several different codes and protocols to distill T, controlled-S, and Toffoli (or CCZ) gates. One construction is based on codes that generalize the triorthogonal codes, allowing any of these gates to be induced at the logical level by transversal T. We present a randomized construction of generalized triorthogonal codes obtaining an asymptotic distillation efficiency γ→1. We also present a Reed-Muller based construction of these codes which obtains a worse γ but performs well at small sizes. Additionally, we present protocols based on checking the stabilizers of CCZ magic states at the logical level by transversal gates applied to codes; these protocols generalize the protocols of. Several examples, including a Reed-Muller code for T-to-Toffoli distillation, punctured Reed-Muller codes for T-gate distillation, and some of the check based protocols, require a lower ratio of input gates to output gates than other known protocols at the given order of error correction for the given code size. In particular, we find a 512 T-gate to 10 Toffoli gate code with distance 8 as well as triorthogonal codes with parameters [[887,137,5]],[[912,112,6]],[[937,87,7]] with very low prefactors in front of the leading order error terms in those codes.
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Zhao, Dan-feng, Hai Tian, and Rui Xue. "Adaptive Rate-Compatible Non-Binary LDPC Coding Scheme for the B5G Mobile System." Sensors 19, no. 5 (2019): 1067. http://dx.doi.org/10.3390/s19051067.
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This paper studies an adaptive coding scheme for B5G (beyond 5th generation) mobile system-enhanced transmission technology. Different from the existing works, the authors develop a class of rate-compatible, non-binary, low-density parity check (RC-NB-LDPC) codes, which expresses the strong connection between the algebra-based and graph-theoretic-based constructions. The constructed codes can not only express rate-compatible (RC) features, but also possess a quasi-cyclic (QC) structure that facilitates the encoding implementation. Further, in order to achieve the code rate-adaptive allocation scheme, the authors propose using the K-means++ clustering algorithm to cluster different channel environments, considering various factors that affect channel characteristics. Finally, in order to present the advantages of the adaptive coding scheme, the authors construct a coding scheme for image transmission. The numerical results demonstrate that the developed code can obtain better waterfall performance in a larger code rate range, which is more suitable for data transmission; the adaptive coding transmission scheme can obtain higher reconstructed image quality compared to the fixed code rate-coding scheme. Moreover, when considering unequal error protection (UEP), the proposed scheme can further improve the reconstructed image quality.
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Xue, Rui, Tong Wang, Yanbo Sun, and Huaiyu Tang. "Optimized Design for NB-LDPC-Coded High-Order CPM: Power and Iterative Efficiencies." Symmetry 12, no. 8 (2020): 1353. http://dx.doi.org/10.3390/sym12081353.
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In this paper, a non-binary low-density parity-check (NB-LDPC) coded high-order continuous phase modulation (CPM) system is designed and optimized to improve power and iterative efficiencies. Firstly, the minimum squared normalized Euclidean distance and the 99% double-sided power bandwidth are introduced to design a competitive CPM, improving its power efficiency under a given code rate and spectral efficiency. Secondly, a three-step method based on extrinsic information transfer (EXIT) and entropy theory is used to design NB-LDPC codes, which reduces the convergence threshold approximately 0.42 and 0.58 dB compared with the candidate schemes. Thirdly, an extrinsic information operation is proposed to address the positive feedback issue in iterative detection and decoding and the value of bit error rate (BER) can approximately be reduced by 5×10−3. Finally, iteration optimization employing the EXIT chart and mutual information between demodulation and decoding is performed to achieve a suitable tradeoff for the communication reliability and iterative decoding delay. Simulation results show that the resulting scheme provides an approximately 3.95 dB coding gain compared to the uncoded CPM and achieves approximately 0.5 and 0.7 dB advantages compared with the candidate schemes. The resulting NB-LDPC-coded high-order CPM for a given code rate and spectral efficiency converges earlier into a turbo cliff region compared with other competitors and significantly improves power and iterative efficiencies.
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Tao, Yang. "Research and Application of Several Error Correction Codes in Communication." Highlights in Science, Engineering and Technology 53 (June 30, 2023): 49–55. http://dx.doi.org/10.54097/hset.v53i.9681.
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Error correction code is an important part of contemporary communication engineering, first proposed by Shannon, and has become mature nowadays. This paper analyzes and compares the error correction capabilities of BCH code, cyclic code, and Hamming code using BPSK modulation in AWGN channels. It unfolds in chronological order, introducing the popular codewords of various eras of the last century in turn. Moreover, it introduces the communication process of BPSK modulation and its addition of three codes and compares the bit error rates of the output signals of them when the input signal is a Bernoulli binary sequence. After simulation, it is found that there is a strong correlation between the number of bit errors in BPSK modulation and the code used and its length At low SNR (signal-to-noise ratio),the error rate error of using codewords or not is minimal. Most digital devices exhibit advantages when the SNR exceeds 4 dB. Under the equivalent SNR, the longer the codeword, the lower the error rate, and the best error correction ability of BCH code (31,11,5). This article only discusses the error correction ability of BPSK under modulation, laying a foundation for comparing the error correction ability of higher order PSK modulation and other code words in the future.
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Kumari, Annushree. "Channel Coding Technique for 5G to Improve Flexibility." International Journal for Research in Applied Science and Engineering Technology 9, no. VII (2021): 2582–89. http://dx.doi.org/10.22214/ijraset.2021.36820.
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5G wireless network will take place after 4G. It will create many new issues. Some problems like, communication with low BER, and performance might be severe issue. In this thesis, coding methods are proposed in order to decrease the signal loss during the transmission process of data. Also, the LDPC system is explained in order to get good results with lower bit error rate over 5G standards by trying to compare it with systems like, LDPC, Convolutional and Turbo code system. Finally, a framework is designed which is a combination of LDPC codes with polar codes in order to improve information transmission efficiency.
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klinkenberg, David. "The Gnostic Code." European Journal of Historical Research 3, no. 1 (2024): 13–18. http://dx.doi.org/10.47672/ejhr.1796.
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Purpose: The aim of the study was to the gnostic code.
 Materials and Methods: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries.
 Findings: The Gnostic parables excerpted above are sufficient to establish that a code was functioning in these documents. By using coded language, the parables obscured a functioning message beneath the veneer of a spiritual or otherwise unintelligible narrative. In multiple textual exchanges, the concept substitution method allows literal and relevant messages to be derived from the text. The literal translations utilize terms from the binary cipher in ways that are clearly out of context. The paragraphs do not make literal sense because of these consistent terms. When the encoded definitions are applied instead of the literal definitions, a new and intelligible message is revealed.
 Implications to Theory, Practice and Policy: It will only be a matter of time before the evidence accumulates to prove that the Gnostic code is real. When the simple substitution code described in this manuscript is applied to the documents in the Nag Hammadi library, it becomes impossible not to see that the code functions. The confu-sion over Gnosticism is understandable considering how far conventional wisdom has to travel in order to appreciate the documents. A consistent code was used by enemies of the Roman Empire in order to hide messages within texts in order to hide their plans.
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Zhang, Qian Hua, and Jian Wu Zhang. "A Construction Method of LDPC Codes for Space Optical Communications Based on Protograph." Applied Mechanics and Materials 631-632 (September 2014): 791–94. http://dx.doi.org/10.4028/www.scientific.net/amm.631-632.791.
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In order to meet the requirements of low bit error-rate of the channel code in the space optical communication system, a construction method of low density parity check ( LDPC) codes with excellent performance is proposed based on protograph and quasi-cyclic expansion. It can be applied in high-speed encoding and decoding with efficient quasi-cyclic expansion. According to the proposed method, a LDPC ( 8832, 1472) suitable for the space optical communication system is constructed, in which the LDPC codes of the protograph perform very well. Simulation shows that the LDPC codes have superior error-correction performance and show no sign of error floor when the BER is in the order of 10-9, which are suitable for the long-distance space optical communication systems.
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Ganmor, E., R. Segev, and E. Schneidman. "Sparse low-order interaction network underlies a highly correlated and learnable neural population code." Proceedings of the National Academy of Sciences 108, no. 23 (2011): 9679–84. http://dx.doi.org/10.1073/pnas.1019641108.
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Asif, Muhammad, Wuyang Zhou, Qingping Yu, Saifullah Adnan, Md Sadek Ali, and Muhammad Shahid Iqbal. "Jointly designed quasi-cyclic LDPC-coded cooperation with diversity combining at receiver." International Journal of Distributed Sensor Networks 16, no. 7 (2020): 155014772093897. http://dx.doi.org/10.1177/1550147720938974.
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This correspondence proposes a jointly-designed quasi-cyclic (QC) low-density parity-check (LDPC)-coded multi-relay cooperation with a destination node realized by multiple receive antennas. First, a deterministic approach is utilized to construct different classes of binary QC-LDPC codes with no length-4 cycles. Existing methods put some limitations in terms of code length and rate in order to provide high error-correction performance. Therefore, this article gives three classes of QC-LDPC codes based on a combinatoric design approach, known as cyclic difference packing (CDP), with flexibility in terms of code-length and rate selection. Second, the proposed CDP-based construction is utilized to jointly-design QC-LDPC codes for coded-relay cooperation. At the receiver, the destination node is realized by multiple receive antennas, where maximal-ratio combining (MRC) and sum-product algorithm (SPA)-based joint iterative decoding are utilized to decode the corrupted sequences coming from the source and relay nodes. Simulation results show that the proposed QC-LDPC coded-relay cooperations outperform their counterparts with a coding gain of about 0.25 dB at bit-error rate (BER) [Formula: see text] over a Rayleigh fading channel in the presence of additive white Gaussian noise. Furthermore, the extrinsic-information transfer (EXIT) chart analysis has been used to detect the convergence threshold of proposed jointly-designed QC-LDPC codes. Numerical analysis shows that the proposed jointly-designed QC-LDPC codes provide a better convergence as compared to their counterparts under the same conditions.
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Tian, Yunke, Yong Bai, and Dake Liu. "Low-Latency QC-LDPC Encoder Design for 5G NR." Sensors 21, no. 18 (2021): 6266. http://dx.doi.org/10.3390/s21186266.
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In order to meet the low latency and high throughput requirements of data transmission in 5th generation (5G) New Radio (NR), it is necessary to minimize the low power encoding hardware latency on transmitter and achieve lower base station power consumption within a fixed transmission time interval (TTI). This paper investigates parallel design and implementation of 5G quasi-cyclic low-density parity-check (QC-LDPC) codes encoder. The designed QC-LDPC encoder employs a multi-channel parallel structure to obtain multiple parity check bits and thus reduce encoding latency significantly. The proposed encoder maps high parallelism encoding algorithms to a configurable circuit architecture, achieving flexibility and support for all 5G NR code length and code rate. The experimental results show that under the 800 MHz system frequency, the achieved data throughput ranges from 62 to 257.9 Gbps, and the maximum code length encoding time under base graph 1 (BG1) is only 33.75 ns, which is the critical encoding time of our proposed encoder. Finally, our proposed encoder was synthesized on SMIC 28 nm CMOS technology; the result confirmed the effectiveness and feasibility of our design.
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Sahin, I., J. Crane, and K. Watson. "Added Mass Coefficients for Submerged Bodies by a Low-Order Panel Method." Journal of Fluids Engineering 115, no. 3 (1993): 452–56. http://dx.doi.org/10.1115/1.2910159.
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The added mass coefficients for two and three-dimensional submerged bodies were calculated using a low-order panel code. The source and dipole strengths, and the panel surface area for each panel, were used to compute the integrals needed for added mass in all six degrees of motions. Several applications of this method were used in comparing the results with the theoretical, when available, experimental or other numerical results. The method was found to be successful in predicting the added mass coefficients using relatively low numbers of panels.
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Zhang, Wenyue, and Min Zhu. "Weighted BATS Codes with LDPC Precoding." Entropy 25, no. 4 (2023): 686. http://dx.doi.org/10.3390/e25040686.
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Batched Sparse (BATS) codes are a type of network coding scheme that use a combination of random linear network coding (RLNC) and fountain coding to enhance the reliability and efficiency of data transmission. In order to achieve unequal error protection for different data, researchers have proposed unequal error protection BATS (UEP-BATS) codes. However, current UEP-BATS codes suffer from high error floors in their decoding performance, which restricts their practical applications. To address this issue, we propose a novel UEP-BATS code scheme that employs a precoding stage prior to the weighted BATS code. The proposed precoding stage utilizes a partially regular low-density parity-check (PR-LDPC) code, which helps to mitigate the high error floors in the weighted BATS code We derive the asymptotic performance of the proposed scheme based on density evolution (DE). Additionally, we propose a searching algorithm to optimize precoding degree distribution within the complexity range of the precoding stage. Simulation results show that compared to the conventional weighted BATS codes, our proposed scheme offers superior UEP performance and lower error floor, which verifies the effectiveness of our scheme.
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Su, Yang, Peng Han, Zhu Jun Jia, and Shi Hua Liang. "Digital Watermarking Based on Two-Way Arnold Transform and QR Code." Advanced Materials Research 591-593 (November 2012): 2564–67. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.2564.
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This paper proposes a digital watermarking algorithm based on two-way Arnold transformation and QR code. This algorithm uses the QR barcode as the watermark, and in its pretreatment process it uses the two-way Arnold transformation to broke up the QR code image into blocks which then coded and re-arranged in a specific order. Considering the role of Singular Value Decomposition in watermark embedding, here the watermark information is embedded into the low frequency coefficients of wavelet transform of the carrier image. Simulation results show that the algorithm is robust against attacks such as shearing, the JPEG compression and noise attacking.
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Zong Chen, Dr Joy Iong. "5G Systems with Low Density Parity Check based Chanel Coding for Enhanced Mobile Broadband Scheme." IRO Journal on Sustainable Wireless Systems 2, no. 1 (2020): 42–49. http://dx.doi.org/10.36548/jsws.2020.1.005.
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The 5G mobile communication standard based radio access technology (RAT) is analysed for implementation of several candidate coding schemes in this paper. The third generation partnership project (3GPP) in the 5G scenario based on the Enhanced mobile broadband (eMBB) scheme is considered. Factors like flexibility, complexity of computation, bit error rate (BER), and block error rate (BLER) are considered for the purpose of evaluation of the coding schemes. In order to evaluate the performance various applications and services, a suitable set is of parameters are provided. The candidate schemes considered for this purpose are polar codes, low density parity check (LDPC) and turbo codes. Fair comparison is performed by investigation of block lengths and obtaining suitable rates by proper design. In an additive white Gaussian noise (AWGN) channel, the performance of BLER / BER is obtained for diverse block lengths and code rates based on simulation. The simulation results show that the performance of LDPC is relatively efficient for various code rates and block lengths despite the better performance of polar codes at short block lengths. As an added advantage, LDPC codes also offer relatively low complexity.
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Crivellini, A., and F. Bassi. "A Three-Dimensional Parallel Discontinuous Galerkin Solver for Acoustic Propagation Studies." International Journal of Aeroacoustics 2, no. 2 (2003): 157–73. http://dx.doi.org/10.1260/147547203322775515.
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The paper presents recent developments of a computational code for the numerical investigation of acoustic propagation. The code solves the three-dimensional linear Euler equations using a Discontinuous Galerkin (DG) method for the spatial discretization and an explicit high-order low-storage Runge-Kutta method for advancing the solution in time. Thanks to DG discretization, high-order accurate numerical solutions on arbitrary unstructured hybrid grids have been easily computed. The code has been parallelized using MPI and preliminary results on a small 10-processor Linux cluster seem very promising.
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Ma, Chao, Li Min Zhang, and Jian Xiong Wang. "Blind Estimation of Long Code DSSS Signal Based on Subspace Tracking." Applied Mechanics and Materials 484-485 (January 2014): 976–81. http://dx.doi.org/10.4028/www.scientific.net/amm.484-485.976.
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Aiming at solving the blind estimation problem of dispreading spectrum sequence under low SNR, a spread-spectrum estimation algorithm based subspace tracking is studied in this paper. This method avoids the direct eigen decomposition, using the sliding window technique to obtain the code synchronization, then use segmentation subspace tracking method estimate spreading sequence and splice in a certain order to achieve pseudo-code blind estimation. The results show that the algorithm can complete the accurate estimation of PN code sequence in low SNR conditions, reduce the amount of data storage and be easy hardware implementation
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Liu, Jie, Xiaojun Tong, Zhu Wang, Jing Ma, and Longteng Yi. "An Improved Rao–Nam Cryptosystem Based on Fractional Order Hyperchaotic System and EDF–QC–LDPC." International Journal of Bifurcation and Chaos 29, no. 09 (2019): 1950122. http://dx.doi.org/10.1142/s0218127419501220.
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A Rao–Nam cryptosystem based on error correction code is proposed to provide both security and reliability. Since its security is drastically constrained by the limited error syndromes, in this paper, an improved Rao–Nam cryptosystem based on fractional order hyperchaotic system and Extended Difference Family–Quasi-Cyclic–Low-Density Parity-Check (EDF–QC–LDPC) codes is proposed to improve the security. A four-dimensional fractional order hyperchaotic system is constructed and is used to generate an excellent pseudorandom sequence. By replacing error syndromes with the pseudorandom sequence and permuting the coded message dynamically, the security of the Rao–Nam cryptosystem is enhanced greatly. The ability of the improved Rao–Nam cryptosystem against known attacks is analyzed and the error correction performance with different parameters is simulated. The results show that the proposed cryptosystem has a significant advantage of resisting the chosen-plaintext attack. Moreover, the proposed cryptosystem retains high capacity of error correction.
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Jorge Fernandez-Mayoralas and Raouia Masmoudi Ghodhbane. "Performance of a parallel Hamming coding in short-frame OFDM sensor's network." ITU Journal on Future and Evolving Technologies 2, no. 1 (2021): 77–88. http://dx.doi.org/10.52953/tdhg1720.
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In this paper, we focus on the most relevant Error Correcting Codes (ECCs): the Hamming code and the Reed-Solomon code in order to meet the trade-off between the low implementation complexity and the high error correction capacity in a short-frame OFDM communication system. Moreover, we discuss and validate via simulations this trade-off between complexity (Hamming is the easiest to code) and error correction capability (Reed-Solomon being the most effective). Therefore, we have to either improve the correction capacity of the Hamming code, or decrease the complexity cost for the Reed-Solomon code. Based on this analysis, we propose a new design of parallel Hamming coding. On the one hand, we validate this new model of parallel Hamming coding with numerical results using MATLAB-Simulink tools and BERTool Application which makes easier the Bit Error Rate (BER) performance simulations. On the other hand, we implement the design of this new model on an FPGA mock-up and we show that this solution of a parallel Hamming encoder/decoder uses a few resources (LUTs) and has a higher capability of correcting when compared to the simple Hamming code.
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Kacheru, Goutham, Nagaraju Arthan, and Rohit Bajjuru. "Artificial Intelligence (AI) for Low-Code and No-Code Development: Making Non-Developers Developers in 2024." Formosa Journal of Multidisciplinary Research 4, no. 1 (2025): 141–50. https://doi.org/10.55927/fjmr.v4i1.13369.
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Low-code and no-code development platforms are here to transform the software development landscape by allowing even non-technical users build applications without the need of their advanced programming skills. Artificial Intelligence (AI) is the most crucial player in this evolution; reinvigorating these platforms with intelligent automation, device responsive templates and user-friendly interfaces (2024). Users can design, build, and deploy applications easily with AI-powered features (e.g., Natural Language Processing (NLP), drag-and-drop functionality to-design application & code-generation tools). Democratization of Application Development These innovations democratize application development, thereby allowing businesses to innovate faster, lessen the reliance on professional developers, and meet the surging demand for digital solutions. In this paper, we look at how AI-assisted low-code and no-code platforms are changing the way new apps are being developed, empowering non-developers to participate in software creation and accelerating automation of app development. It also presents the challenges and future aspects that we have to deal with in order to use AI on these platforms, as well as their future role of building a bridge between technical expertise and creative problem-solving.
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Yi, Yan. "The Design of 2D Bar Code Recognition Software on Android." Advanced Materials Research 442 (January 2012): 453–57. http://dx.doi.org/10.4028/www.scientific.net/amr.442.453.
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In order to promote the application of two dimensional barcode on mobile phone, this paper uses the popular Android technology, and researches QR code format and the decode process of the QR code; and then designs 2D bar code recognition system based on the decode library Zxing. After testing, it is proved that the system has good generality and low resource consuming, and the software of itself is only 140 K.
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Jin, Ayoung, and Younghwan Pan. "A Study on Citizen Developer Competency and Development Process in Low-Code/No-Code Development System." Korean Society of Culture and Convergence 44, no. 11 (2022): 119–31. http://dx.doi.org/10.33645/cnc.2022.11.44.11.119.
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The era of easy development of apps is opening as the cloud computing environment develops and the need for RPA increases. The development of the low-code/no-code development system has led to the emergence of citizen developers who can create their own apps without little or no coding knowledge. This study investigated the characteristics and types of citizen developers through a survey. The characteristics of citizen developers were identified as marketers, planners, developers, designers, ordinary people, and most of them want to develop RPA apps. The most common types of citizen developers were identified as power users with a little knowledge of coding. In-depth interviews also revealed that the competency required of citizen developers is the most important, and unlike in the past, the order of the development process is very flexible, and the role of app development participants has become very ambiguous.
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Amerini, Alberto, Leonardo Langone, Riccardo Vadi, and Antonio Andreini. "Assessment of a hybrid propulsion system for short-mid range application with a low-order code." E3S Web of Conferences 312 (2021): 11005. http://dx.doi.org/10.1051/e3sconf/202131211005.
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The increase in air traffic expected in the next years must be accompanied by innovation to ensure the lowest possible environmental impact. Hybrid electric-thermal propulsion systems are currently being investigated and could represent a breakthrough for environmental sustainability in the sector. However, the transition to electric propulsion remains challenging due to the current level of energy density related to storage systems, the additional components associated with power conversion and control systems, not to mention the cost of all the associated equipment. The purpose of this study is to carry out a preliminary assessment of a hybrid propulsion system for a short-mid range aircraft. This study investigates the series hybrid configuration, where a turboshaft, a high temperature superconducting (HTS) electric motor, batteries and power converters interact to provide the necessary propulsion for flight. A zero-dimensional procedure is developed to estimate the mass and efficiency of the powertrain components for a selected flight mission. Thermal engines are modeled with the low-order code and coupled with the components of the electric system through a python routine. A comparison in terms of weight and emissions is reported for the designed hybrid propulsion system and the conventional one. The analysis shows that the weight of the two propulsion systems is similar but, the presence of batteries, even considering a higher level of technology than the current one, leads to a significant increase in the weight of the hybrid aircraft. The second part of the study focuses on pollutant emissions, showing that the hybrid system can reduce CO2 emissions by 58% and NOx emissions by 68% compared to the conventional system. Despite the excellent premise, the reduction in payload for the hybrid aircraft causes a reduction in pollutant emissions per passenger only for NOx. For this reason, further technological improvement is needed to make hybrid propulsion advantageous in terms of both payload and pollutant emissions.
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Blazewicz, Marek, Ian Hinder, David M. Koppelman, et al. "From Physics Model to Results: An Optimizing Framework for Cross-Architecture Code Generation." Scientific Programming 21, no. 1-2 (2013): 1–16. http://dx.doi.org/10.1155/2013/167841.
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Starting from a high-level problem description in terms of partial differential equations using abstract tensor notation, theChemoraframework discretizes, optimizes, and generates complete high performance codes for a wide range of compute architectures. Chemora extends the capabilities of Cactus, facilitating the usage of large-scale CPU/GPU systems in an efficient manner for complex applications, without low-level code tuning. Chemora achieves parallelism through MPI and multi-threading, combining OpenMP and CUDA. Optimizations include high-level code transformations, efficient loop traversal strategies, dynamically selected data and instruction cache usage strategies, and JIT compilation of GPU code tailored to the problem characteristics. The discretization is based on higher-order finite differences on multi-block domains. Chemora's capabilities are demonstrated by simulations of black hole collisions. This problem provides an acid test of the framework, as the Einstein equations contain hundreds of variables and thousands of terms.
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Xue, Jiaxin, Yupeng Li, Yichao Zhang, Xiao Wu, and Yanyue Zhang. "Investigation of IEEE 802.16e LDPC Code Application in PM-DQPSK System." Electronics 13, no. 10 (2024): 1887. http://dx.doi.org/10.3390/electronics13101887.
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With the development of the Internet and information technology, optical fiber communication systems need to meet people’s information demand for large capacity and high speed. High-order phase modulation and channel multiplexing can improve the capacity and data rate of optical fiber communication systems, but they also bring the problem of bit error. To improve the transmission quality and reliability of optical fiber communication systems, forward error correction (FEC) coding techniques are commonly used, which serve as the fundamental approach to enhance the quality and reliability of fiber optic communication systems, ensuring that the received data remain accurate and reliable. The FEC in optical fiber communication systems is divided into three generations. The first generation FEC is mainly hard decision codewords, represented as RS code. The second generation FEC is mainly cascaded code, which stands for interleaved cascaded code. The third generation of FEC mainly refers to soft decision codes, which are represented as low-density parity-check (LDPC) codes. As a kind of FEC, LDPC codes stand out as pivotal contributors in the field of optical communication and have gained remarkable attention due to exceptional error correction performance and low decoding complexity. Based on IEEE802.16e standard, LDPC code with specific code length and rate is compiled and simulated in MATLAB and VPItransmissionMaker 10.1 and successfully incorporated into polarization multiplexed differential quadrature phase shift keying (PM-DQPSK) coherent optical transmission system. The simulation results indicate that the bit error rate (BER) can be reduced to 10−3 when the optical signal-to-noise ratio (OSNR) reaches 14.2 dB, and the BER experiences a reduction by nearly three orders of magnitude when the OSNR is 17.2 dB. These findings underscore the efficacy of LDPC codes in significantly improving the performance of optical communication systems, particularly in scenarios demanding robust error correction capabilities. This study provides valuable, significant results regarding the potential of LDPC codes for enhancing the reliability of optical transmission in real-world applications.
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Andreini, A., and B. Facchini. "Gas Turbines Design and Off-Design Performance Analysis With Emissions Evaluation." Journal of Engineering for Gas Turbines and Power 126, no. 1 (2004): 83–91. http://dx.doi.org/10.1115/1.1619427.
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Many gas turbines simulation codes have been developed to estimate power plant performance both in design and off-design conditions in order to establish the adequate control criteria or the possible cycle improvements; estimation of pollutant emissions would be very important using these codes in order to determine the optimal performance satisfying legal emission restrictions. This paper present the description of a one-dimensional emission model to simulate different gas turbine combustor typologies, such as conventional diffusion flame combustors, dry-low NOx combustors (DLN) based on lean-premixed technology (LPC) or rich quench lean scheme (RQL) and the new catalytic combustors. This code is based on chemical reactor analysis, using detailed kinetics mechanisms, and it is integrated with an existing power plant simulation code (ESMS Energy System Modular Simulator) to analyze the effects of power plant operations and configurations on emissions. The main goal of this job is the study of the interaction between engine control and combustion system. This is a critical issue for all DLN combustors and, in particular, when burning low-LHV fuel. The objective of this study is to evaluate the effectiveness of different control criteria with regard to pollutant emissions and engine performances. In this paper we present several simulations of actual engines comparing the obtained results with the experimental published data.
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Kang, Chong. "A New World of Lakes—An Exploration of the Code for a New Low Carbon Realm—The Upgrading of Horticultural Lake in Mianyang Science City New District as an Example." Journal of Research in Social Science and Humanities 2, no. 3 (2023): 51–56. http://dx.doi.org/10.56397/jrssh.2023.03.07.
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This paper focuses on the upgrading project of Horticulture Lake in China's Science and Technology City-Miangyang, and summarizes the seven major problems of the current situation by sorting out the problems of the current situation of Horticulture Lake. With natural ecology and green sponge as the design concept of renovation and upgrading, seven major renovation and upgrading measures are proposed, such as the code of lake ecology, the code of three-dimensional ecological lake scape, the code of green ecological sponge, the code of road system upgrading, the code of flower border upgrading, the code of plant landscape upgrading and the code of ground cover upgrading of Song Shou Lan, in order to create a new scene of green technology and low-carbon life.
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Legrady, David, Marton Pukler, Balint Panka, and Gabor Tolnai. "Coupling the GUARDYAN code to subchanflow." EPJ Nuclear Sciences & Technologies 9 (2023): 11. http://dx.doi.org/10.1051/epjn/2023002.
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GUARDYAN is a GPU-based dynamic Monte Carlo code developed at the Budapest University of Technology and Economics, Hungary. Dynamic Monte Carlo computes the neutron population evolution by calculating the direct time dependence of the neutron histories in multiplying systems. Some well-established Monte Carlo codes have DMC versions with coupling to Thermal-Hydraulic solvers. GUARDYAN has the computational advantage of applying GPUs, thus calculation burden can be carried by commonly available hardware, and is capable of handling power plant size systems for kinetics problems. GUARDYAN has been recently coupled to the subchannel thermal-hydraulics code SUBCHANFLOW in order to carry out dynamic calculations with TH feedback. This paper describes some convergence studies regarding reaching the initial equilibrium state. A literature-suggested set of TH input settings and high sample numbers resulted in very low statistical errors of the power estimates and stable global measures (L2) of power release, fuel, and coolant temperatures for both static and dynamic convergence. Dynamic mode low-sample simulations provided surprisingly stable global L2 measures, correct fuel temperatures, and power release, while coolant temperatures were off, without any indication of the incorrectness of the result. Static convergence showed an alternating, fluctuating L2 behavior that did not affect the final stable state.
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Hajji, Amine, Christine Coquelet-Pascal, and Patrick Blaise. "A hybrid approach for neutronics calculations in the neutron shielding of sodium fast reactors." EPJ Nuclear Sciences & Technologies 7 (2021): 17. http://dx.doi.org/10.1051/epjn/2021016.
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Neutron calculations in the neutron shielding of fast neutron reactors are a complex problem as deterministic schemes are usually not suited for such calculations while Monte-Carlo codes have poor computational performance due to the very low flux levels in neutron shields. In this article, both methods are studied, as well as a hybrid scheme on the neutron shielding of the ASTRID fast reactor benchmark. This hybrid scheme uses a fission source calculated by a deterministic code in order to precisely calculate neutron fluxes in the shielding with a Monte-Carlo code using variance reduction techniques. This provides reference results in order to validate deterministic calculations. Comparisons between deterministic codes and this hybrid reference show that large biases are obtained, up to 50%. Further studies are made to reduce the biases, showing that many physical phenomena should be treated, including anisotropy of the scattering law at high energies and spatial self-shielding inside the boron carbide shielding. These improvements reduce the biases to less than 10%. Finally, some applications to designing criteria for the neutron shielding are presented, such as gas production in the neutron shielding and activation of secondary sodium at the intermediate heat exchanger (IHX).
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Chen, Yuxin, Jie Cheng, Xiaodong Li, Xue Bai, and Zhixi Nie. "Research on Tracking Technique Based on BPSK-CSK Signals." Electronics 13, no. 8 (2024): 1517. http://dx.doi.org/10.3390/electronics13081517.
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The code-shift keying (CSK) modulation method can achieve higher information transmission rates without changing the spread spectrum signal bandwidth. In order to optimise the spread spectrum modulation and demodulation of GNSS signals, in addition to the signal structure, binary phase-shift keying (BPSK) and CSK signals using time-division multiplexing are proposed. A tracking method based on the BPSK-CSK signals is also proposed, which generates the P-branch local codes by fast Fourier transform to obtain the code-slice spacings for the E-branch and the L-branch local codes. Then, the tracked BPSK signals and tracked CSK signals are compared and analysed. Finally, the bit error rate (BER) and tracking error of each method are compared and analysed by comparing with the tracking of conventional BPSK signals and tracking of CSK signals, in order to verify the convergence process of the I-branch integral value. The BPSK-CSK signal tracking method proposed in this paper combines the high information transmission rate of CSK-modulated signals and the low BER of BPSK signals, and the results provide a solid foundation for high-precision GNSS services.
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Hirata, F. P., R. G. M. de Andrade, and J. C. Della Bella. "Comparative analysis between prediction models in codes and test data for shear strength." Revista IBRACON de Estruturas e Materiais 6, no. 6 (2013): 875–902. http://dx.doi.org/10.1590/s1983-41952013000600004.
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Since the beginning of twentieth century, along with academic publications of Ritter and Mörsch, several studies have been done in order to understand shear strength in reinforced concrete elements. Approximately 1,200 laboratory tests results of reinforced concrete beams under shear stresses were used in a comparative analysis among values from prediction models of codes and laboratory tests results, enabling classification of the codes according to their applicability in several tests intervals. Although the Brazilian Code NBR 6118 (2007) showed good results in usual ranges of parameters, it presented unsatisfactory results on the following cases: low and medium shear transverse reinforcement rate.
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Kuo, F. A., and J. S. Wu. "Implementation of a parallel high-order WENO-type Euler equation solver using a CUDA PTX paradigm." Journal of Mechanics 37 (2021): 496–512. http://dx.doi.org/10.1093/jom/ufab016.
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ABSTRACT This study proposes the optimization of a low-level assembly code to reconstruct the flux for a splitting flux Harten–Lax–van Leer (SHLL) scheme on high-end graphic processing units. The proposed solver is implemented using the weighted essentially non-oscillatory reconstruction method to simulate compressible gas flows that are derived using an unsteady Euler equation. Instructions in the low-level assembly code, i.e. parallel thread execution and instruction set architecture in compute unified device architecture (CUDA), are used to optimize the CUDA kernel for the flux reconstruction method. The flux reconstruction method is a fifth-order one that is used to process the high-resolution intercell flux for achieving a highly localized scheme, such as the high-order implementation of SHLL scheme. Many benchmarking test cases including shock-tube and four-shock problems are demonstrated and compared. The results show that the reconstruction method is computationally very intensive and can achieve excellent performance up to 5183 GFLOP/s, ∼66% of peak performance of NVIDIA V100, using the low-level CUDA assembly code. The computational efficiency is twice the value as compared with the previous studies. The CUDA assembly code reduces 26.7% calculation and increases 37.5% bandwidth. The results show that the optimal kernel reaches up to 990 GB/s for the bandwidth. The overall efficiency of bandwidth and computation performance achieves 127% of the predicted performance based on the HBM2-memory roofline model estimated by Empirical Roofline Tool.
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Al-nahari, A. Y., F. E. Abd El-Samie, and M. I. Dessouky. "Distributed Space-Time/Frequency Coding Schemes for Single-Carrier Frequency Division Multiple Access Systems." ISRN Communications and Networking 2011 (April 4, 2011): 1–10. http://dx.doi.org/10.5402/2011/549706.
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The single carrier-frequency division multiple access (SC-FDMA) system is a new system that was adopted in the standardization of the upcoming 3GPP long-term evolution (LTE). Designing diversity-achieving schemes for the SC-FDMA system is a challenging task. The codes adopted should not affect the peak-to-average power ratio (PAPR) among other constraints. In this paper, we consider the design of cooperative diversity schemes for SC-FDMA systems in the uplink direction. Specifically, two relay-assisted distributed space-time/frequency codes are proposed. The proposed distributed space-frequency code (SFC) achieves full spatial diversity in the uplink fast-fading channels, where a diversity of order three can be achieved. The proposed code keeps a low PAPR, which is a good feature of the system. A minimum mean square error (MMSE) decoder is used at the receiver of the destination node. Moreover, we propose a bandwidth-efficient distributed space-time code (STC) for slow-fading relay channels. A decode-and-forward (DF) protocol is used at the relay node, and the possibility of erroneous decoding is taken into account. Simulation results demonstrate the performance improvement of the proposed schemes.
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Nazarov, L. E. "//." Радиотехника и электроника 68, no. 9 (2023): 873–78. http://dx.doi.org/10.31857/s003384942309019x.
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A description of the algorithm for optimal symbol-by-symbol reception of signal structures based on block noise-resistant codes in non-binary Galois fields is given. It is shown that the basis of this algorithm is the fast spectral transformation algorithm in the Walsh–Hadamard basis with the dimension of the Galois field. It is shown that the resulting complexity of the analyzed character-by-character reception algorithm is determined by the dimension of the dual code, which determines the prospects of its application for block noise-resistant codes with a high code rate (with low redundancy). The results of modeling a character-by-symbol reception algorithm are presented in order to study noise immunity for a number of frequency-efficient digital signals with quadrature-amplitude and amplitude-phase manipulations (with frequency coefficient efficiencies of 3, 4 and 6 bps/Hz) in combination with a parity check code. It is shown that the use of a symbol-by-symbol reception algorithm provides an energy gain of up to 1.5...3.0 dB in relation to the transmission and reception of the considered series of signals without coding.
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Righi, Mauro, Vassilios Pachidis, László Könözsy, Fanzhou Zhao, and Mehdi Vahdati. "Three-dimensional low-order surge model for high-speed axial compressors." Journal of the Global Power and Propulsion Society 4 (December 18, 2020): 274–84. http://dx.doi.org/10.33737/jgpps/130790.
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Surge in modern aero-engines can lead to violent disruption of the flow, damage to the blade structures and eventually engine shutdown. Knowledge of unsteady performance and loading during surge is crucial for compressor design, however, the understanding and prediction capability for this phenomenon is still very limited. While useful for the investigation of specific cases, costly experimental tests and high-fidelity CFD simulations cannot be used routinely in the design process of compressor systems. There is therefore an interest in developing a low-order model which can predict compressor performance during surge with sufficient accuracy at significantly reduced computational cost. This paper describes the validation of an unsteady 3D through-flow code developed at Cranfield University for the low-order modelling of surge in axial compressors. The geometry investigated is an 8-stage rig representative of a modern aero-engine IP compressor. Two deep surge events are modelled at part speed and full speed respectively. The results are compared against high-fidelity, full annulus, URANS simulations conducted at Imperial College. Comparison of massflow, pressure and temperature time histories shows a close match between the low-order and the higher-fidelity methods. The low-order model is shown capable of predicting many transient flow features which were observed in the high-fidelity simulations, while reducing the computational cost by up to two orders of magnitude.
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Carter, S., J. M. Bowman, and B. J. Braams. "On using low-order Hermite interpolation in `direct dynamics' calculations of vibrational energies using the code `MULTIMODE'." Chemical Physics Letters 342, no. 5-6 (2001): 636–42. http://dx.doi.org/10.1016/s0009-2614(01)00656-x.
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Tang, Jun, Zhaocai Deng, Zhaokai Dang, and Chuanqing Li. "Fractional Low-Order Blind Equalization Algorithm Based On SAPSO Optimization under Impulsive Noise." Journal of Physics: Conference Series 2480, no. 1 (2023): 012021. http://dx.doi.org/10.1088/1742-6596/2480/1/012021.
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Abstract To address the problem that the traditional constant mode blind equilibrium algorithm (CMA) cannot converge stably in a water channel under α-stable distributed noise, we propose a fractional low-order blind equilibrium algorithm (SAPSO-FLOSCMA) based on simulated annealing particle swarm algorithm optimization. The algorithm introduces a simulated annealing operation in the particle swarm algorithm (PSO) to make the population accept the difference solution with a certain probability of accepting the difference solution to enhance the ability of the PSO algorithm to jump out of the local optimal solution. Then the cost function of the FLOSCMA algorithm is used as the fitness function of the SAPSO algorithm, and the global optimal solution is iteratively searched by using the SAPSO algorithm. The global optimal solution is used as the initial weight vector of the equalizer. The underwater acoustic simulation results show that compared with the CMA and FLOSCMA, the algorithm improves the convergence speed and reduces the inter-code interference.
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Hussein, Yasmeen M., Basman M. Al-Nedawe, Ammar Hussein Mutlag, and Ameer K. Jawad. "Application of Error Correction Codes RS and LDPC to Enhance the Dicode Pulse Position Modulation." Journal of Hunan University Natural Sciences 49, no. 1 (2022): 161–69. http://dx.doi.org/10.55463/issn.1674-2974.49.1.21.
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Dicode Pulse Position Modulation (DiPPM) has been presented as a new coding technique with several improvements over earlier PPM formats. Few analyses and experimental results have been published because it is a new coding scheme. To overcome the problem of bandwidth utilization in current PPM formats, DiPPM can be employed. The line rate is twice as fast as the original data rate. In order to increase DiPPM's error performance, two types of Forward Error Correction (FEC) codes, Reed-Solomon (RS) code and low-density parity-check (LDPC) code, are investigated in this article. When RS and LDPC function at their optimal parameters, the results show an improvement in DiPPM system error performance. The error performance of an uncoded DiPPM system was compared to that of a DiPPM-encoded LDPC system and a system utilizing the Reed-Solomon algorithm. Transmission efficiency is measured by the number of photons per pulse and bandwidth widening. When the bandwidth is 1x103 times or more than the initial data rate, DiPPM with LDPC code exceeds uncoded DiPPM and DiPPM with RS, using 1.821 x 103 photons per pulse, with a codeword length of 27 and code rate of 0.75.
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Brjuhanov, Jurij. "Quantization effects in digital first order recursive filters with values truncation." Izvestiya VUZ. Applied Nonlinear Dynamics 10, no. 6 (2003): 35–41. http://dx.doi.org/10.18500/0869-6632-2002-10-6-35-41.
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Free oscillation and oscillation under a constant level input signal in low-frequency and high-frequency filters are considered. We use fixed point numbers in additional code. The method of one-dimensional point mapping is applied. Dynamical regimes are characterized by probabilistic diagrams. Expressions for most probably oscillation in the filter’s output with arbitrary numbers of quantization levels are defined. Given methods may be used for quantization effects investigation in the first-order digital filters with representation of the numbers in direct, inverse and additional code with rounding and truncation.