W. L. Oliver · 1980
Abstract : An efficient machine implementation of the 1972 COSPAR International Reference Atmosphere (CIRA) is developed for use in evaluating atmospheric-drag effects upon earth-orbiting satellites. Restriction of this procedure to the satellite-orbit region of significant drag and the use of an alternate temperature profile representation have enabled a factor of 30 improvement in machine execution time compared with that required by the code supplied by CIRA publication while incurring only a few percent difference in the density results. (Author)
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Yann THEBAUT · Zenodo (CERN European Organization for Nuclear Research) · 2026
Numerical simulation code supporting the paper"Coherence Percolation and Morphological Transitions in Density-Regulated Phase Networks". The code implements a two-dimensional network of phase oscillators with stress regulation,coherence-guided density transport, and morphological diagnostics of coherent domains.
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Bin Hu, Dongjin Yu, Yijian Wu et al. · Science of Computer Programming · 2024
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Laurent Hascoët, Matt Menickelly, Sri Hari Krishna Narayanan et al. · Computer Physics Communications · 2025
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I. Introduction, J. M. Perez, K. Andrews · 2007
This work describes a method for encoding low-density parity-check (LDPC) codes based on the accumulate–repeat–4–jagged–accumulate (AR4JA) scheme, using the low-density parity-check matrix H instead of the dense generator matrix G.
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George Digkas · 2021
Technical Debt (TD) is a powerful metaphor that represents shortcuts taken in a software development project, usually to meet business goals such as limited time or budget. Technical Debt concerns mostly invisible parts of the system (i.e. no visible features or defects) and has a detrimental effect on the maintainability and evolvability of software. Technical Debt manifests in both design and implementation constructs such as sub-optimal design decisions, design and code smells, use of impertinent technologies, lack of documentation etc.
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Laurent Hascoët, Matt Menickelly, Sri Hari Krishna Narayanan et al. · ArXiv.org · 2025
The HFBTHO code implements a nuclear energy density functional solver to model the structure of atomic nuclei. HFBTHO has previously been used to calibrate energy functionals and perform sensitivity analysis by using derivative-free methods. To enable derivative-based optimization and uncertainty quantification approaches, we must compute the derivatives of HFBTHO outputs with respect to the parameters of the energy functional, which are a subset of all input parameters of the code. We use the algorithmic/automatic differentiation (AD) tool Tapenade to differentiate HFBTHO. We compare the derivatives obtained using AD against finite-difference approximation and examine the performance of the derivative computation.
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Fleck, Patrick · reposiTUm (TU Wien) · 2022
Aus heutiger Sicht sind Tätigkeiten und Entscheidungsprozesse in den Bereichen Software-Qualitätsmanagement und -Qualitätssicherung zu essenziellen Bestandteilen gängiger Software-Entwicklungsprozesse avanciert. Es existieren vielfältige Software-Metriken, welche im Bereich der Software-Entwicklung tätigen Personen als Grundlage für Entscheidungenim Rahmen von Maßnahmen zur Verbesserung und Aufrechterhaltung der Qualität eines Software-Produkts dienen. Obwohl erwähnte Metriken bereits sehr gut in bestehende praxisorientierte Werkzeuge (z.B.: Code Coverage Tools) integriert wurden, zeigt diese Diplomarbeit, dass dennoch zahlreicheschwer erfüllbare Informationsbedürfnisse im Bereich Software-Qualitätsmanagement und -Qualitätssicherung existieren. Im Speziellen werden im Zuge dieser Arbeit prominente Informationsbedürfnisse in diesem Kontext gesammelt, diskutiert und aktuell verfügbaren Code Coverage Tools gegenübergestellt, welche auf deren Erfüllung abzielen. Diese Recherche in Bezug auf den aktuellen Stand der Technik zeigt, dass derzeit eklatante Informationslücken in den Bereichen Risikoanalyse von Codeänderungen und Refactorings, Wartung von Test Suites und der Analyse von Testredundanzen bestehen. Auf dieser Basis wird in dieser Diplomarbeit die Metrik Code Coverage Density eingeführt, welche klassische Code Coverage um die Beschreibung der Verteilung der Testfälle über ein bestimmtes Software-Artefakt erweitert. Des Weiteren umfasst diese Arbeit die Implementierung eines Prototyps, welcher auf dieser Metrik basierende Features bzw. Visualisierungen zur Verfügung stellt und auf die Erfüllung der identifizierten Informationsbedürfnisse abzielt. Zudem wird eine szenariobasierte Expertenevaluierung unter Zuhilfenahme eines vom Prototyp generierten Coverage Density Reports durchgeführt. Die Ergebnisse dieser Evaluierung zeigen, dass die eingeführte Metrik und die darauf aufbauenden Visualisierungen ein bemerkenswertes Potenzial zur Unterstützung bei Tätigkeiten in den Bereichen Risikoanalyse von Codeänderungen und Refactorings und Wartung von Test Suites mit sich bringen. Es wird außerdem gezeigt, dass das eingeführte Konzept im Rahmen der Analyse von Testredundanzen bei detaillierteren Untersuchungen von vorab als potentielle Redundanzen identifizierten Tests beitragen kann, jedoch nicht zur Auffindung von ebendiesen geeignet ist.
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Nyoman Pramaita · Liverpool John Moores University · 2016
One of the primary tasks of the mobile system designers in order to support high density of devices in a CDMA system is to create a code sequence with a capacity for large number of spreading code sequences having low cross-correlation values between them, in order to ensure accommodation of large number of users and to minimise the effect of multiple access interference. In this research, the design for a novel hybrid orthogonal very large set (HOVLS) code sequence is proposed for high density mobile application scenarios. The design and development of both fixed and variable spreading factor code sequences are presented in this thesis. Both type of code sequences have been implemented via simulation using Matlab/Simulink. The performance of the code sequences has been evaluated and compared with that of existing code sequences. The proposed code sequences are more advantageous for high density mobile networks. The unique feature of the fixed length HOVLS code sequence is that its ACF, CCF, and BER performances are similar to that of orthogonal Gold code sequence and orthogonal m-sequence under Rayleigh flat and frequency selective fading channel conditions while having a significantly higher capacity than those orthogonal code sequences. The proposed HOVLS code sequence could support 134 different cells which is more than twice than that of orthogonal Gold code sequence and orthogonal m-sequence. To the knowledge of the author, this is the largest reported family size in the literature for an orthogonal code sequence for CDMA applications.In order to support variable data rate, fixed length HOVLS code sequence was developed into orthogonal variable spreading factor code sequence. It is shown that the proposed OVSF code sequence has slightly better CCF than those of OVSF Gold code sequence and m-sequence in terms of CM (correlation margin). The ACF of the proposed OVSF code sequence is similar to those of OVSF Gold code sequence and m-sequence. The proposed OVSF code sequence possesses comparable BER performance to those of orthogonal Gold code sequence and orthogonal m-sequence under flat fading channel condition. Whereas, the BER performance of the proposed OVSF code sequence is slightly better than that of Gold code sequence and OVSF m-sequence under frequency selective fading channel.Therefore, the proposed HOVLS code sequence is appropriate code sequence in CDMA systems than those of orthogonal Gold code sequence and orthogonal m-sequence for both fixed and variable rate high density network applications.
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Tzoufras, M, Bell, AR, Norreys, PA et al. · Oxford University Research Archive (ORA) (University of Oxford) · 2011
OSHUN is a parallel relativistic 2D3P Vlasov-Fokker-Planck code, developed primarily to study electron transport and instabilities pertaining to laser-produced-including laser-fusion-plasmas. It incorporates a spherical harmonic expansion of the electron distribution function, where the number of terms is an input parameter that determines the angular resolution in momentum-space. The algorithm employs the full 3D electromagnetic fields and a rigorous linearized Fokker-Planck collision operator. The numerical scheme conserves energy and number density. This enables simulations for plasmas with temperatures from MeV down to a few eV and densities from less than critical to more than solid. Kinetic phenomena as well as electron transport physics can be recovered accurately and efficiently. © 2011 Elsevier Inc.
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Roffe, J., White, D.R., Burton, S. et al. · White Rose Research Online (University of Leeds, The University of Sheffield, University of York) · 2020
We show that belief propagation combined with ordered statistics post-processing is a general decoder for quantum low-density parity-check codes constructed from the hypergraph product. To this end, we run numerical simulations of the decoder applied to three families of hypergraph product code: topological codes, fixed-rate random codes, and a new class of codes that we call semitopological codes. Our new code families share properties of both topological and random hypergraph product codes, with a construction that allows for a finely controlled trade-off between code threshold and stabilizer locality. Our results indicate thresholds across all three families of hypergraph product code, and provide evidence of exponential suppression in the low error regime. For the toric code, we observe a threshold in the range 9.9%±0.2%. This result improves upon previous quantum decoders based on belief propagation, and approaches the performance of the minimum-weight perfect-matching algorithm. We expect semitopological codes to have the same threshold as toric codes, as they are identical in the bulk, and we present numerical evidence supporting this observation.
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J.A. Delgado-Penin, A. Correas-Corcobado · SBT/IEEE International Symposium on Telecommunications · 2002
The adaptive multilevel code (AMC) is a DC-free line code with four levels and two lengths. Both levels and lengths carry information. For a stationary memoryless source, closed-form expressions for the spectra of the AMC coded signals have been obtained analytically using the transition probability matrix method. Results comparing the one-sided spectral densities of the AMC, alternate mark inversion, and biphase waveforms are presented. The advantages of AMC are demonstrated.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
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Kiyoshi Shibanuma, Takemasa Shibata · Shinku · 1989
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Sara Salama, Rashed Salem, Hatem Abdelkader · 2019
In data area, to achieve good information for decision making, suitable processing of data is needed. Data need to be transferred. They are transferred as a vector which contains features of data. During data transferring, errors may occur. Errors change the features of data vector (instance). In this case, error detection and correction techniques are needed to tackle this issue. If data transferred as groups based on its features, any change in the features of any vector will change the group (cluster) of this vector. So, to cluster an incomprehensible data for operating any method of data mining, an influential technique is needed, and this technique should ensure the correctness of the cluster using error detection and correction codes like Hamming and Golay. This paper presents a technique to detect and correct clustered data after the transfer process to reduce the misclustered instances. The main concept is the reemploying the error-correction Golay code with splitting of the data word and code word to symbols. DENCLUE clustering algorithm is used in the step of clustering as density-based clustering algorithm. Comparison with other related works is performed and the simulation results stated that the proposed technique achieved better performance.
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Fleck, Patrick · reposiTUm (TU Wien) · 2022
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M. Tzoufras, A. R. Bell, P. A. Norreys et al. · Journal of Computational Physics · 2011
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Yann THEBAUT · Zenodo (CERN European Organization for Nuclear Research) · 2026
Numerical simulation code supporting the paper"Coherence Percolation and Morphological Transitions in Density-Regulated Phase Networks". The code implements a two-dimensional network of phase oscillators with stress regulation,coherence-guided density transport, and morphological diagnostics of coherent domains.
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Andrea Rossi · CERN Document Server (European Organization for Nuclear Research) · 2004
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Chin-kuang Lian · 2015
In recent years, low-density parity-check (LDPC) codes have attracted a lot of attention due to the near Shannon limit coding gains when iteratively decoded. Thus, the LDPC codes have been well recognized as an excellent error correction coding
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Hönel, Sebastian · Zenodo (CERN European Organization for Nuclear Research) · 2020
Git Density (<code>git-density</code>) is a tool to analyze <code>git</code>-repositories with the goal of detecting the source code density. It was developed during the research phase of the short technical paper and poster "<em>A changeset-based approach to assess source code density and developer efficacy</em>" and has since been extended to support thorough analyses and insights.
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