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Littérature scientifique sur le sujet « Walsh matrix »

Auteur : Grafiati

Publié le 9 mars 2023

Mis à jour le 19 juillet 2025

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Articles de revues sur le sujet "Walsh matrix"

Wan, K. F., P. C. Ching, and C. K. Li. "A Set of Split-Matrix Ordered Walsh Functions." Journal of Circuits, Systems and Computers 07, no. 06 (1997): 537–42. http://dx.doi.org/10.1142/s0218126697000401.

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A new set of Walsh functions is defined in terms of the split-matrix ordering. The intrinsic properties of the functions are analyzed. The relationship and the associated conversion rules between the newly defined functions and other typical Walsh functions are discussed. It is shown that the proposed Walsh functions provide a straighforward and efficient algorithm for fast Discrete Walsh Transformation.

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Беспалов, М. С., and К. А. Фролов. "Information encoding by linear permutations of discrete Walsh transform." Proceedings in Cybernetics 23, no. 3 (2024): 90–95. https://doi.org/10.35266/1999-7604-2024-3-10.

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The paper proposes a method for using a code matrix as a private key for the Walsh-Hadamard code. The number of possible code matrices has been calculated. For example, there are almost 10 million possible keys for a Walsh matrix of the order 32, they are also level 5. The paper describes the method of decoding information and the procedure for isolating the code matrix from the encrypted Walsh matrix.

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ASAHI, Hideyasu. "A Function Generator for Walsh Order Hadamard Matrix and Fast Walsh-Hadamard Transform." Geoinformatics 11, no. 1 (2000): 3–9. http://dx.doi.org/10.6010/geoinformatics1990.11.1_3.

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Tsuneda, Akio. "Orthogonal Chaotic Binary Sequences Based on Bernoulli Map and Walsh Functions." Entropy 21, no. 10 (2019): 930. http://dx.doi.org/10.3390/e21100930.

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The statistical properties of chaotic binary sequences generated by the Bernoulli map and Walsh functions are discussed. The Walsh functions are based on a 2 k × 2 k Hadamard matrix. For general k (= 1 , 2 , ⋯ ), we will prove that 2 k - 1 Walsh functions can generate essentially different balanced and i.i.d. binary sequences that are orthogonal to each other.

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Alghamdi, Mohammed A., and M. Mursaleen. "Hankel matrix transformation of the Walsh–Fourier series." Applied Mathematics and Computation 224 (November 2013): 278–82. http://dx.doi.org/10.1016/j.amc.2013.08.075.

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Adi, Prajanto Wahyu, Adi Wibowo, Guruh Aryotejo, and Ferda Ernawan. "Fragile watermarking for image authentication using dyadic walsh ordering." International Journal of Advances in Intelligent Informatics 9, no. 3 (2023): 490. http://dx.doi.org/10.26555/ijain.v9i3.1017.

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A digital image is subjected to the most manipulation. This is driven by the easy manipulating process through image editing software which is growing rapidly. These problems can be solved through the watermarking model as an active authentication system for the image. One of the most popular methods is Singular Value Decomposition (SVD) which has good imperceptibility and detection capabilities. Nevertheless, SVD has high complexity and can only utilize one singular matrix S, and ignore two orthogonal matrices. This paper proposes the use of the Walsh matrix with dyadic ordering to generate a new S matrix without the orthogonal matrices. The experimental results showed that the proposed method was able to reduce computational time by 22% and 13% compared to the SVD-based method and similar methods based on the Hadamard matrix respectively. This research can be used as a reference to speed up the computing time of the watermarking methods without compromising the level of imperceptibility and authentication.

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Samanta, Supriti, Goutam K. Maity, and Subhadipta Mukhopadhyay. "Implementation of Orthogonal Codes Using MZI." Micro and Nanosystems 12, no. 3 (2020): 159–67. http://dx.doi.org/10.2174/1876402912666200211121624.

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Background: In Code Division Multiple Access (CDMA)/Multi-Carrier CDMA (MCCDMA), Walsh-Hadamard codes are widely used for its orthogonal characteristics, and hence, it leads to good contextual connection property. These orthogonal codes are important because of their various significant applications. Objective: To use the Mach–Zehnder Interferometer (MZI) for all-optical Walsh-Hadamard codes is implemented in this present paper. Method: The Mach–Zehnder Interferometer (MZI) is considered for the Tree architecture of Semiconductor Optical Amplifier (SOA). The second-ordered Hadamard and the inverse Hadamard matrix are constructed using SOA-MZIs. Higher-order Hadamard matrix (H4) formed by the process of Kronecker product with lower-order Hadamard matrix (H2) is also analyzed and constructed. Results: To experimentally get the result from these schemes, some design issues e,g Time delay, nonlinear phase modulation, extinction ratio, and synchronization of signals are the important issues. Lasers of wavelength 1552 nm and 1534 nm can be used as input and control signals, respectively. As the whole system is digital, intensity losses due to couplers in the interconnecting stage may not create many problems in producing the desired optical bits at the output. The simulation results were obtained by Matlab-9. Here, Hadamard H2 (2×2) matrix output beam intensity (I ≈ 108 w.m-2) for different values of inputs. Conclusion: Implementation of Walsh-Hadamard codes using MZI is explored in this paper, and experimental results show the better performance of the proposed scheme compared to recently reported methods using electronic circuits regarding the issues of versatility, reconfigurability, and compactness. The design can be used and extended for diverse applications for which Walsh-Hadamard codes are required.

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Alotaibi, Abdullah, and M. Mursaleen. "Applications of Hankel and Regular Matrices in Fourier Series." Abstract and Applied Analysis 2013 (2013): 1–3. http://dx.doi.org/10.1155/2013/947492.

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Recently, Alghamdi and Mursaleen (2013) used the Hankel matrix to determine the necessary and suffcient condition to find the sum of the Walsh-Fourier series. In this paper, we propose to use the Hankel matrix as well as any general nonnegative regular matrix to obtain the necessary and sufficient conditions to sum the derived Fourier series and conjugate Fourier series.

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Au-Yeung, Enrico. "Sparse reconstruction with multiple Walsh matrices." Advances in Pure and Applied Mathematics 10, no. 3 (2019): 221–39. http://dx.doi.org/10.1515/apam-2017-0047.

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Abstract The problem of how to find a sparse representation of a signal is an important one in applied and computational harmonic analysis. It is closely related to the problem of how to reconstruct a sparse vector from its projection in a much lower-dimensional vector space. This is the setting of compressed sensing, where the projection is given by a matrix with many more columns than rows. We introduce a class of random matrices that can be used to reconstruct sparse vectors in this paradigm. These matrices satisfy the restricted isometry property with overwhelming probability. We also discuss an application in dimensionality reduction where we initially discovered this class of matrices.

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CHOU, JYH-HORNG, and ING-RONG HORNG. "Simple methods for the shift-transformation matrix, direct-product matrix and summation matrix of discrete Walsh series." International Journal of Control 43, no. 4 (1986): 1339–42. http://dx.doi.org/10.1080/00207178608933542.

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Thèses sur le sujet "Walsh matrix"

MOLTENI, MARIA CHIARA. "ON THE SECURITY OF CRYPTOGRAPHIC CIRCUITS:PROTECTION AGAINST PROBING ATTACKS AND PERFORMANCE IMPROVEMENT OF GARBLED CIRCUITS." Doctoral thesis, Università degli Studi di Milano, 2022. http://hdl.handle.net/2434/920426.

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Dealing with secure computation and communication in hardware devices, an attacker that threatens to security of the systems can be of two different types. The first type of attacker is external to the exchange of secret messages and tries to steal some sensitive information. Probing a circuit is a useful technique through which an attacker can derive information correlated with the secret manipulated by a cryptographic circuit. Probing security is the branch of research that tries to devise models, tools and countermeasures against this type of attacks. We define a new methodology that allows to determine if a gadget (i.e., a portion of a circuit) is secure against probing attacks. Moreover, we reason about composability of gadgets, in such a way that also this composition is probing secure. The reasoning is extended also to the case in which glitches are considered, namely when the attacks are mounted when timing hazards are present. The proposed methodology is based on the construction of the Walsh matrix of a Boolean function that describes the operations of the circuit. This method allows reaching an exact solution, but generally needs a lot of computation’s time (mainly for big gadgets). To overcome the problem, we propose to compute the Walsh matrix exploiting the theory and applications of Algebraic Decision Diagrams (ADDs). Different is the case when the malicious part is internal: each party is interested in protecting its own sensitive information from all the others. When the parties are only two, from literature the garbled circuit protocol is a solution that allows to reach a result implying some secrets, without sharing them. The cost of this protocol depends on the number of extit{and} gates in the circuit that implements the Boolean function describing the protocol computations. In this context, we work to reduce the number of multiplications in two classes of particular Boolean functions, called autosymmetric and D-reducible. Moreover, in the context of the garbled circuit protocol, we discuss some innovative solutions to further reduce the protocol's costs, as the application of the 3-valued logic. This logic is an extension of the Boolean one, resulting from the addition of a new element to the set Boolean set ${0,1}$.

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Livres sur le sujet "Walsh matrix"

Hqny, Unicef. Guía para la Elaboración de Estrategias Financieras en Materia de Agua, Saneamiento e Higiene (WASH. United Nations Children's Fund, The (UNICEF), 2022.

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Liaudat, Santiago, Julián Bilmes, and Andrés Carbel, eds. Planificación, gestión y política pública. Facultad de Trabajo Social (UNLP), 2022. http://dx.doi.org/10.35537/10915/140080.

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Los países de América Latina suelen pasar por bruscos movimientos pendulares en materia política. Los cambios de gobierno se traducen, habitualmente, en quiebres y discontinuidades que afectan las capacidades estatales de planificación y gestión pública. En particular, cuando representantes del neoliberalismo acceden a los poderes ejecutivos. En cuanto a las administraciones nacional-populares, progresistas o de izquierda, suelen carecer de métodos de gobierno y enfrentan serias dificultades en la concreción de sus metas. Una de las causas es que, como dijera Rodolfo Walsh, “la experiencia colectiva se pierde, las lecciones se olvidan”. Para enfrentar la desmemoria, este libro se recupera las experiencias y discusiones de la Argentina reciente en torno a la planificación, la gestión y la política pública. En la primera parte, quince funcionarios/as, especialistas académicos y dirigentes de los empresarios y de los trabajadores son entrevistados. Se abordan sectores tales como industria, ciencia y tecnología, agro, empleo público, energía, defensa, telecomunicaciones, integración socio-urbana y desarrollo productivo. En la segunda parte, se incluyen dos trabajos de investigación. En el primero, se reflexiona sobre la necesidad de incorporar en la formación universitaria esta problemática. En el segundo, se analizan logros y limitaciones de la planificación durante los gobiernos de Néstor Kirchner y Cristina Fernández (2003-2015).

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Reseña técnica sobre el agua, el saneamiento, la higiene y la gestión de aguas residuales para prevenir las infecciones y reducir la propagación de la resistencia a los antimicrobianos. Organización Panamericana de la Salud, 2020. http://dx.doi.org/10.37774/9789275322956.

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El presente informe técnico tiene como objeto sustentar los elementos en materia de agua, saneamiento e higiene (WASH, por su sigla en inglés) y de aguas residuales de los planes de acción nacionales multisectoriales que abordan la resistencia a los antimicrobianos. Comprende un resumen de la evidencia y la fundamentación de los beneficios colaterales derivados de las medidas en cada sector y en él además se presenta una serie de medidas para su consideración y perfeccionamiento en el contexto de cada país. Asimismo, contiene opciones de política específicas para cada sector e información adicional, incluidas las lagunas en el conocimiento y las necesidades en el campo de la investigación, así como los recursos técnicos adicionales para apoyar la planificación y la ejecución. Versión oficial en español de la obra original en inglés. Technical brief on water, sanitation, hygiene and wastewater management to prevent infections and reduce the spread of antimicrobial resistance. © World Health Organization (WHO), Food and Agriculture Organization of the United Nations (FAO) and World Organisation for Animal Health (OIE), 2020

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Chapitres de livres sur le sujet "Walsh matrix"

Mursaleen, M. "Matrix Summability of Fourier and Walsh-Fourier Series." In SpringerBriefs in Mathematics. Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-04609-9_8.

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Alman, Josh. "Faster Walsh-Hadamard Transform and Matrix Multiplication over Finite Fields using Lookup Tables." In Symposium on Simplicity in Algorithms (SOSA). Society for Industrial and Applied Mathematics, 2023. http://dx.doi.org/10.1137/1.9781611977585.ch13.

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Kekre, H. B., Sudeep D. Thepade, and Varun K. Banura. "Image Retrieval Using Texture Patterns Generated from Walsh-Hadamard Transform Matrix and Image Bitmaps." In Communications in Computer and Information Science. Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-20209-4_14.

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Phillips, Christina, and Patrick Howard. "Utilizing Collaborative Self-Study to Explore Pedagogies for Sustainability." In Sustainable Development Goals Series. Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-56172-6_19.

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AbstractWhole school approaches (Wals and Mathie, Whole school approaches to sustainability: Exemplary practices from around the world. Wageningen University, Education and Learning Sciences, 2022) to sustainability where various facets or currents of environmental education (e.g., Sauvé, Can J Environ Educ 10(1): 11–37, 2005) are seamlessly integrated with disciplinary subject matter, leadership practices, and everyday classroom routines remain elusive in many contexts as they serve as counter-narratives to the status quo promoting over-consumption and exploitation of environments and people. We present a case study exploring how a Canadian post-secondary institution, Cape Breton University, has enacted inclusive (e.g., Indigenous perspectives), whole school approaches to sustainability in novel and immersive ways. We present this work as a reflexive, collaborative self-study examining program objectives in teacher education and how these sustainability goals have been interpreted, translated, and implemented at the course level in pre-service teacher education (i.e., science methods courses) and at the graduate level (i.e., an applied research project course for the Master of Education in Sustainability, Creativity, and Innovation).

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Eikeland, Ingrid, and Astrid Sinnes. "Activating the Petals in the ‘WSA Flower Model’: Critical Factors for Sustaining Schools’ Pathways Towards a Whole-School Approach." In Sustainable Development Goals Series. Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-56172-6_12.

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AbstractIn this chapter, we describe four Norwegian upper secondary schools’ paths towards a whole school approach (WSA) to sustainability. Since 2017, these schools have been part of a longitudinal university–school partnership, together with a school owner and a teacher education. The aim of the partnership was to develop the learning institutions’ sustainability education. The data have been analysed through the lens of the ‘WSA flower model’ (Wals & Mathie, 2022). As a result, we found that the four schools took different paths towards a WSA (e.g. they were initiated by enthusiastic teachers or the leader group). Nonetheless, what the schools had in common was that more petals in the WSA flower model were activated as the partnership evolved. Furthermore, the activation of more petals was related to more focus on robust sustainability in the schools. Thus, we conclude that schools may follow different paths towards sustainability, yet the crucial factor seems to be that more than one petal in the WSA flower model needs to be activated to sustain a school’s journey towards a WSA. We also acknowledge the important role the overarching partnership played as a catalyst for both activating the petals and keeping them active.

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Phuthi, Brita. "Exploring a Whole-School Approach at Nonformal Folk High Schools in Norway Through Common Goals and Action Learning." In Sustainable Development Goals Series. Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-56172-6_22.

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AbstractOver the last 9 years, the Norwegian Folk High Schools (FHSs) have engaged in implementation of the Sustainable Development Goals (SDGs) through common projects focusing on the school’s operation and teaching. This chapter critically analyses and reflects on two collective FHS initiatives the FHSs have engaged in. To consider the challenges and opportunities of the schools’ sustainability processes, a Whole-School Approach (WSA) flower model by Wals and Mathie (Whole School responses to climate urgency and related sustainability challenges. In: Peters MA, Heraud R (eds) Encyclopedia of educational innovation. Springer. https://doi.org/10.1007/978-981-13-2262-4_263-1, 2022) is employed as an analytical lens. The chapter finds that the FHS pedagogy engages with all six elements of the flower model and when the FHS pedagogy is practiced, it provides living examples of learning sites practicing a WSA to sustainability. The FHSs participating in joint sustainability initiatives, seeing that neighboring schools also make changes, reinforce that the community and common goals of the FHSs matter. The chapter concludes that the FHSs WSA to learning is an ongoing process, involving dialogue and fostering democratic confidence.

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Sundararajan, P. R., and Mostofa Kamal Khan. "Poly(vinyl butyral)." In Polymer Data Handbook. Oxford University PressNew York, NY, 2009. http://dx.doi.org/10.1093/oso/9780195181012.003.0196.

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Abstract Major Applications The significant use is in lamination of safety glass (automotive windshields). Others are structural adhesives, binders for rocket propellants, ceramics, in metallized brake linings, lithographic and offset printing plates, magnetic tapes, powder coatings; binder matrix in photoactive, elecrooptic and electronic devices, protective coatings for glass, metal, wood, and ceramics; in wash primers for protecting metal surfaces (e.g., naval vessels); adhesion promoter in inks; dispersions used in textile industry to improve abrasion resistance and reduce color crocking.

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Actes de conférences sur le sujet "Walsh matrix"

Kilic, Muhammed Nur Talha, Vishu Gupta, Yuwei Mao, et al. "Enhancing Deep Neural Network Classification Performance Through Novel Weight Initialization: t-SNE Supported Walsh Matrix Approach." In 2024 International Conference on Machine Learning and Applications (ICMLA). IEEE, 2024. https://doi.org/10.1109/icmla61862.2024.00153.

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Al-Hindas, Fahad A., Faisal M. Al-Abbas, Olavo C. Dias, and Nasser M. Balhareth. "Impact of Throughput Increment on Corrosion Enablers and Risk Levels in a Hydrocracking Unit – Case Study." In CORROSION 2015. NACE International, 2015. https://doi.org/10.5006/c2015-05488.

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Abstract Increasing plant capacity is one of the critical changes that should be assessed thoroughly to avoid the possibility of increasing corrosion risks and introducing hazards to operations, processes, and control parameters. A systematic approach was developed and utilized to directly assess the impact of the capacity increase in a hydrocracking unit. This study has determined the possible changes in corrosion drivers and subsequent corrosion loops, risk matrix, and inspection strategies using a quantitative risk-based decision process. The sensitivity analysis revealed that increased capacity requires focus in the following areas: erosion-corrosion due to velocity increases and ammonium bisulfide (NH4HS) fouling. Process simulations along with Risk Based Inspection assessments were employed. The study concluded that the capacity increase is feasible provided: the water wash treatment is increased to account for additional NH4HS, additional on-stream inspection points are provided for systems susceptible to erosion-corrosion, and selective metallurgical upgrades are planned for improved sulfidation resistance.

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shan, jia, ZHAO Xi-Wei, ZHOU Cheng, and SONG Li-Jun. "Computational ghost imaging based on Walsh matrix replication." In Optical Sensing and Imaging Technology, edited by HaiMei Gong, John E. Greivenkamp, Jun Tanida, Yadong Jiang, Jin Lu, and Dong Liu. SPIE, 2019. http://dx.doi.org/10.1117/12.2547593.

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Adi, Prajanto Wahyu, and Pramudi Arsiwi. "Fast and Robust Watermarking Method using Walsh Matrix Partition." In 2019 International Seminar on Research of Information Technology and Intelligent Systems (ISRITI). IEEE, 2019. http://dx.doi.org/10.1109/isriti48646.2019.9034627.

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Zhou, Jinyao, Jiayao Xu, Jirayu Peetakul, and Jinjia Zhou. "Zigzag Ordered Walsh Matrix for Compressed Sensing Image Sensor." In 2023 Data Compression Conference (DCC). IEEE, 2023. http://dx.doi.org/10.1109/dcc55655.2023.00064.

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Alman, Josh, and Kevin Rao. "Faster Walsh-Hadamard and Discrete Fourier Transforms from Matrix Non-rigidity." In STOC '23: 55th Annual ACM Symposium on Theory of Computing. ACM, 2023. http://dx.doi.org/10.1145/3564246.3585188.

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Yubao, Cheng, and Sun Zhongtao. "Application of Walsh Matrix in Encoding Laser Beam for Pointing Multi-Target." In 2007 8th International Conference on Electronic Measurement and Instruments. IEEE, 2007. http://dx.doi.org/10.1109/icemi.2007.4351195.

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Cai Zhuoran, Zhao Honglin, Jia Min, Wang Gang, and Shen Jingshi. "An improved Hadamard measurement matrix based on Walsh code for compressive sensing." In 2013 9th International Conference on Information, Communications & Signal Processing (ICICS). IEEE, 2013. http://dx.doi.org/10.1109/icics.2013.6782833.

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Pacheco, Ricardo P., and Valder Steffen. "On Time Domain Identification and Sensitivity Analysis Using Orthogonal Functions." In ASME 1999 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/detc99/vib-8365.

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Abstract Orthogonal functions can be integrated using a so-called operational matrix. This characteristic transforms a set of second order differential equations into algebraic equations which are easily solved. In the case of mechanical systems the unknown parameters can be determined from these algebraic equations. For this purpose, the input and output signals have to be expanded in time orthogonal functions. This technique can be also applied for sensitivity analysis. In this paper Fourier series, Legendre polynomials, Jacobi polynomials, Chebyshev series, Block-Pulse functions and Walsh functions are used to expand the signals as time functions.

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Yang, Chia-Hsin, and Hamid Emami-Meybodi. "Performance Prediction of Multi-Fractured Horizontal Wells in Shale Gas Condensate Reservoirs Using Flowback Rate Transient Analysis." In SPE Conference at Oman Petroleum & Energy Show. SPE, 2025. https://doi.org/10.2118/224869-ms.

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Abstract Flowback data following hydraulic fracturing (HF) provide crucial insights into HF characteristics through rate transient analysis (RTA). However, most flowback RTA methods for shale gas reservoirs overlook the effects of condensate dropout. In this study, we developed a two-dimensional (2D) three-phase flowback model with the three-phase influx that captures the two primary flow regimes: infinite-acting linear flow (IALF) and boundary-dominated flow (BDF). The model considers three-phase water, gas, and condensate (oil) flow from the matrix to the fracture and from fracture to wellbore. This model analyzes flowback data during HF depletion, even in the presence of condensate dropout. To enhance its analytical capability, we revised the Walsh material balance equation to estimate the average HF pressure and redefined the pseudo-variables to generate diagnostic plots for flow regime identification, along with specialized plots for HF characterization. We validated our proposed iterative processes against numerical simulations. Our three-phase flow models' estimated half-length and initial HF permeability closely matched the numerical model's set values, with relative errors below 10%. These results demonstrate that the proposed three-phase flowback model significantly improves our understanding of early HF dynamics and the initial behavior of condensate within the HF system and surrounding matrix.

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