Articles de revues : « Modèle Rate Theory »

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Raffo López, Leonardo. « Una discusión sobre la curva de Phillips de Friedman y la tasa natural de desempleo ». Lecturas de Economía, n^o 67 (31 juillet 2009) : 119–42. http://dx.doi.org/10.17533/udea.le.n67a2023.

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En este escrito se evalúa la consistencia teórica de la Curva de Phillips de Milton Friedman. Para esto se retoma la exposición de Friedman, destacando sus aportes al análisis de corto plazo del desempleo, los salarios y los precios, frente a la teoría de los clásicos y a la de Keynes. Se examina la hipótesis basada en la tasa natural de desempleo, revisando la utilización de los conceptos de desempleo involuntario, equilibrio macroeconómico e información imperfecta, así como los mecanismos de formación de expectativas de empresarios y trabajadores. Se concluye que su modelo es impreciso e incompleto y que su hipótesis se derrumba si la tasa natural de desempleo es endógena y cambia con los choques exógenos de demanda agregada. Palabras Clave: Curva de Phillips, desempleo involuntario, tasa natural de desempleo, información imperfecta, expectativas adaptativas. Clasificación JEL: E24, E31, E32, B22. Abstract: In this paper I evaluate the theoretical consistency of Friedman.s Phillips curve. For this, I review his own exposition in the subject, making emphasis in his contributions to the short-run analysis of unemployment, wages and prices in front of the classical theory and Keynes.s .General Theory.. I examine his hypothesis founded in the natural rate of unemployment, looking at the use of concepts like involuntary unemployment, macroeconomic equilibrium and imperfect information, and also at the mechanism of expectation.s formation for workers and entrepreneurships. My conclusion is that his model is incomplete and imperfect, and that his hypothesis tumbles down if the natural rate of unemployment is endogenous and changes with the exogenous chocks in aggregate demand. Keywords: Phillips curve, involuntary unemployment, natural rate of unemployment, imperfect information, adaptative expectations. JEL classification: E24, E31, E32, B22. Résumé: Dans cet article on évalue la cohérence théorique de la Courbe de Phillips de Milton Friedman. Pour ce faire, on reprend l.exposition de Friedman tout en soulignant sa contribution à l.étude du chômage dans le court terme, des salaires et des prix face à la théorie classiques et à la théorie keynésienne. On examine l.hypothèse du taux de chômage naturel et l.utilisation des concepts de chômage involontaire, d.équilibre macro-économique et d.information imparfaite, ainsi que les mécanismes de formation des anticipations des entrepreneurs et des travailleurs. On conclut que son modèle est imprécis et incomplet car l.hypothèse d.un taux de chômage naturel s.effondre lorsque le taux de chômage naturel est endogène et sa variation dépend des chocs exogènes de la demande agrégée. Mots Clef: Courbe de Phillips, chômage involontaire, taux de chômage naturel, information imparfaite, anticipations adaptatives. Classification JEL: E24, E31, E32, B22.

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Trojanowska, M. « Applicability of models based on deterministic chaos theory for forecasting of electricity sales in rural areas ». Research in Agricultural Engineering 52, No. 1 (7 février 2012) : 25–29. http://dx.doi.org/10.17221/4876-rae.

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The applicability of models based on deterministic chaos theory, in particular the self-similar fractal models, logistic models according to Prigogine, logistic models according to Schuster, and heuristic crossing models for one-year-ahead forecasting of the sales of electric energy in the rural areas, is verified in the paper. The model quality assessment was carried out based on the errors analysis of the 10-year ex post forecasts of the electric energy sale to rural consumers by three selected distribution companies. As the electric energy consumption were disturbed by economic crises, the forecasts were developed using not only annual sales value but also using their 2-, 3-, 4- and 5-year totals. The best forecast were obtained when the electric energy sales were predicted using the Schuster and heuristic crossing models, made on the basis of four- and five-year totals of annual sales values.

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Et. al., Shaik Irfan Babu,. « A PIC controlled based heart rate miniaturization using GSM ». Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, n^o 10 (28 avril 2021) : 4765–71. http://dx.doi.org/10.17762/turcomat.v12i10.5232.

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We used advanced technologies in this module to track patients suffering from heart failure and physical disorders. As a consequence, a heart rate sensor and a temperature sensor are utilized to track the patient. Sensors provide precise results, obviating the need for conventional medical instruments such as thermometers and other devices. GSM modem is used to transmit messages from the patient's position to the medical advisory. This module relieves medical advisors of the burden of patient monitoring while also allowing patients to travel about freely.

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Wang, Wen Bin, Dao Yuan Liu et Yu Qin Yao. « Research and Design of Digital down Converter Based on Software Defined Radio ». Applied Mechanics and Materials 513-517 (février 2014) : 1803–6. http://dx.doi.org/10.4028/www.scientific.net/amm.513-517.1803.

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This paper makes a brief introduction on the current development trend of software radio and digital down converter status. The basic theoretical knowledge: Band-pass sampling theorem, digital signal orthogonal transformation theory, multi-rate signal processing theory. Based on these theories, use MATLAB complete the design and verification of mixing module, the extraction module (CIC filter, half-band filter and FIR filters), finally verify the correctness of the design, and implement DDC.

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Xu, Ying, Wentao Tang, Biyun Chen, Li Qiu et Rong Yang. « A Model Predictive Control with Preview-Follower Theory Algorithm for Trajectory Tracking Control in Autonomous Vehicles ». Symmetry 13, n^o 3 (26 février 2021) : 381. http://dx.doi.org/10.3390/sym13030381.

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Research on trajectory tracking is crucial for the development of autonomous vehicles. This paper presents a trajectory tracking scheme by utilizing model predictive control (MPC) and preview-follower theory (PFT), which includes a reference generation module and a MPC controller. The reference generation module could calculate reference lateral acceleration at the preview point by PFT to update state variables, and generate a reference yaw rate in each prediction point. Since the preview range is increased, PFT makes the calculation of yaw rate more accurate. Through physical constraints, the MPC controller can achieve the best tracking of the reference path. The MPC problem is formulated as a linear time-varying (LTV) MPC controller to achieve a predictive model from nonlinear vehicle dynamics to continuous online linearization. The MPC-PFT controller method performs well by increasing the effective length of the reference path. Compared with MPC and PFT controllers, the effectiveness and robustness of the proposed method are proved by simulations of two typical working conditions.

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Ho, Chii-Dong, Luke Chen, Jr-Wei Tu, Yu-Chen Lin, Jun-Wei Lim et Zheng-Zhong Chen. « Investigation of CO2 Absorption Rate in Gas/Liquid Membrane Contactors with Inserting 3D Printing Mini-Channel Turbulence Promoters ». Membranes 13, n^o 12 (4 décembre 2023) : 899. http://dx.doi.org/10.3390/membranes13120899.

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The CO2 absorption by Monoethanolamine (MEA) solutions as chemical absorption was conducted in the membrane gas absorption module with inserting 3D mini-channel turbulence promoters of the present work. A mathematical modeling of CO2 absorption flux was analyzed by using the chemical absorption theory based on mass-transfer resistances in series. The membrane absorption module with embedding 3D mini-channel turbulence promoters in the current study indicated that the CO2 absorption rate improvement is achieved due to the diminishing concentration polarization effect nearby the membrane surfaces. A simplified regression equation of the average Sherwood number was correlated to express the enhanced mass-transfer coefficient of the CO2 absorption. The experimental results and theoretical predictions showed that the absorption flux improvement was significantly improved with implementing 3D mini-channel turbulence promoters. The experimental results of CO2 absorption fluxes were performed in good agreement with the theoretical predictions in aqueous MEA solutions. A further absorption flux enhancement up to 30.56% was accomplished as compared to the results in the previous work, which the module was inserted the promoter without mini channels. The influences of the MEA absorbent flow rates and inlet CO2 concentrations on the absorption flux and absorption flux improvement are also illustrated under both concurrent- and countercurrent-flow operations.

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Mutema, Gaudencia. « Sur les citoyens et les minorités modèles : perspectives de la Critical Race Theory appliquées à l’éducation ». Nordiques, n^o 28 (1 novembre 2014) : 89–102. http://dx.doi.org/10.4000/nordiques.6050.

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Lin, Guoqian, Samuel Bimenyimana, Ming-Lang Tseng, Ching-Hsin Wang, Yuwei Liu et Lingling Li. « Photovoltaic Modules Selection from Shading Effects on Different Materials ». Symmetry 12, n^o 12 (15 décembre 2020) : 2082. http://dx.doi.org/10.3390/sym12122082.

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This study aims to provide photovoltaic module selection with better performance in the shading condition for improving production efficiency and reducing photovoltaic system investment cost through the symmetry concept, combining both solar energy mathematical and engineering principles. The study builds a symmetrical photovoltaic model and uses the series-parallel circuit theory, piecewise function and Matlab simulation. The voltage and current output characteristics of commercial photovoltaic modules made of different materials and structures are analyzed and their shading effects are evaluated. The results show that for each photovoltaic module, the output power is directly proportional to the irradiance. The output voltage of the photovoltaic module slightly increases and the output current greatly decreases from no shading to shading. The rate of output power reduction varies for each photovoltaic module type when the irradiance changes. The thin film modules show a lower output power reduction rate than crystalline photovoltaic modules from no shading to shading and they have good adaptability to shading. The use of thin film photovoltaic modules is recommended when the shading condition cannot be avoided.

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Park, No-Suk, Sukmin Yoon, Woochang Jeong et Yong-Wook Jeong. « Application of Double Piping Theory to Parallel-Arrayed Low-Pressure Membrane Module Header Pipe and Experimental Verification of Flow Distribution Evenness ». Membranes 12, n^o 7 (20 juillet 2022) : 720. http://dx.doi.org/10.3390/membranes12070720.

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In this study, the improvement effect of flow distribution evenness is evaluated quantitatively by applying the double piping theory to a parallel-arrayed low-pressure membrane module header pipe structure, and its feasibility is discussed. Orifice inner pipes to be inserted into a full-scale membrane module header pipe are designed via the computational fluid dynamics (CFD) technique, and the flow rates into 10 membrane modules are measured in real time using a portable ultrasonic flowmeter during operation to verify the effect. Results of CFD simulation and actual measurements show that the outflow rate from the branch pipe located at the end of the existing header pipe is three times higher than the flow rate from the branch pipe near the inlet. By inserting two inner pipes (with an open end and a closed end into the existing header pipe) and applying the double pipe theory, the flow distribution evenness is improved. The CFD simulation and experimental results show that the flow uniformity can be improved by more than 70% and 50%, respectively.

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Li, Xue Jun, Zhi Cheng He et Qi Li. « Research of Direct Sequence Spread Spectrum Communication System Based on MATLAB ». Applied Mechanics and Materials 103 (septembre 2011) : 279–84. http://dx.doi.org/10.4028/www.scientific.net/amm.103.279.

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This paper described the theory which based on the spread spectrum communication system, a simulation model was designed based on MATLAB, and each module of the model was briefly introduced. In a particular simulation condition, ran the simulation program, and an expected result was obtained. Meanwhile, by design a spread spectrum communication system of two users, detect the bit error rate corresponding with the two users in different bit error rate (SNR), directly verified the validity of the model system.

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Zhu, Min. « The Construction of University Network Education System Based on Mobile Edge Computing in the Era of Big Data ». Wireless Communications and Mobile Computing 2022 (12 janvier 2022) : 1–11. http://dx.doi.org/10.1155/2022/1368841.

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This article first established a university network education system model based on physical failure repair behavior at the big data infrastructure layer and then examined in depth the complex common causes of multiple data failures in the big data environment caused by a single physical machine failure, all based on the principle of mobile edge computing. At the application service layer, a performance model based on queuing theory is first established, with the amount of available resources as a conditional parameter. The model examines important events in mobile edge computing, such as queue overflow and timeout failure. The impact of failure repair behavior on the random change of system dynamic energy consumption is thoroughly investigated, and a system energy consumption model is developed as a result. The network education system in colleges and universities includes a user login module, teaching resource management module, student and teacher management module, online teaching management module, student achievement management module, student homework management module, system data management module, and other business functions. Later, the theory of mobile edge computing proposed a set of comprehensive evaluation indicators that characterize the relevance, such as expected performance and expected energy consumption. Based on these evaluation indicators, a new indicator was proposed to quantify the complex constraint relationship. Finally, a functional use case test was conducted, focusing on testing the query function of online education information; a performance test was conducted in the software operating environment, following the development of the test scenario, and the server’s CPU utilization rate was tested while the software was running. The results show that the designed network education platform is relatively stable and can withstand user access pressure. The performance ratio indicator can effectively assist the cloud computing system in selecting a more appropriate option for the migrated traditional service system.

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Zhou, Lingxi, Chenwei Hu, Yuxiang Chen, Peijie Guo, Jinyi Liu, Yu Chen et Jiayu Cao. « Research on a Chassis Stability Control Method for High-Ground-Clearance Self-Propelled Electric Sprayers ». Applied Sciences 14, n^o 17 (2 septembre 2024) : 7734. http://dx.doi.org/10.3390/app14177734.

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In response to the complex working conditions and poor driving stability of high-clearance self-propelled sprayers, a nonlinear model of the chassis power system was established based on the independently controllable torque of each wheel of the developed electric sprayer. A layered-architecture chassis drive control strategy was formulated, and a stability control framework comprising an instability judgment module, an upper controller, and a lower controller was constructed based on the analysis of the impact of the centroid slip angle, the yaw rate, and the wheel slip rate on driving stability. An ideal reference model was established based on the seven-degree-of-freedom model of the sprayer, and the current state of the sprayer body was determined using the instability judgment module. A drive anti-slip controller and a yaw moment controller based on fuzzy PID theory and sliding mode control theory were designed. Additionally, an optimal torque distribution algorithm was developed based on tire characteristics to rationally allocate drive torque to each wheel, ensuring the stability of the sprayer during operation. Simulation tests were conducted using MATLAB/Simulink to evaluate the sprayer under four different driving conditions during transport and field operations. The test results showed that the “SMC + optimal distribution” control method in the chassis stability control strategy reduced the maximum deviations of the yaw rate and centroid slip angle by an average of 89.5% and 13.6%, respectively, compared to no control. The wheel slip rate during straight driving was well maintained at around 15%, enhancing the driving stability of the sprayer.

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Mo, Xinyue, Huan Li, Lei Zhang et Zongxi Qu. « A Novel Air Quality Evaluation Paradigm Based on the Fuzzy Comprehensive Theory ». Applied Sciences 10, n^o 23 (2 décembre 2020) : 8619. http://dx.doi.org/10.3390/app10238619.

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Air pollution is a prominent problem all over the world, seriously endangering human life. To protect the environment and human health, timely and accurate air quality evaluations are imperative. Recently, with the increasing focus on air pollution, an evaluation tool that can offer intuitive air quality information is especially needed. Though the Air Quality Index (AQI) has played this role over the years, its intrinsic limitations discussed in this study (sharp boundary, biased evaluation, conservative strategy and incomplete criterion) are gradually apparent, limiting its air quality evaluation capability. Therefore, a novel paradigm, the Air Quality Fuzzy Comprehensive Evaluation (AQFCE), is proposed. In the preprocessing module, missing and reversal data are handled by a least square piecewise polynomial fitting and linear regression. An improved fuzzy comprehensive evaluation model is adopted to solve the AQI’s above limitations in the evaluation module. The early warning module provides a timely alert and recommendation. To validate the performance of the AQFCE, Beijing, Shanghai and Xi’an in China are selected for case studies, and daily and hourly concentration data of six conventional air pollutants from September 2018 to August 2019 are employed. For daily reports, the AQFCE and AQI have a high consistent rate and correlation coefficient regarding chief pollutants and levels, respectively, while examples show the level of the AQFCE is more reasonable. For hourly reports, AQI has antinomies and cannot reflect actual pollution, but the AQFCE is still effective. Current major pollutants, “weekend and holiday effect” and “peak type” of pollution are also revealed by the AQFCE. Experiment results prove that the AQFCE is accurate under different pollution conditions and an important supplement to the AQI. Furthermore, the AQFCE can provide health guideline for the public and assist the government in making environmental decisions and development policies.

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Kim, Kyung Tae, Jo Eun Park, Seon Yeop Jung et Tae Gon Kang. « Fouling Mitigation via Chaotic Advection in a Flat Membrane Module with a Patterned Surface ». Membranes 11, n^o 10 (23 septembre 2021) : 724. http://dx.doi.org/10.3390/membranes11100724.

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Fouling mitigation using chaotic advection caused by herringbone-shaped grooves in a flat membrane module is numerically investigated. The feed flow is laminar with the Reynolds number (Re) ranging from 50 to 500. In addition, we assume a constant permeate flux on the membrane surface. Typical flow characteristics include two counter-rotating flows and downwelling flows, which are highly influenced by the groove depth at each Re. Poincaré sections are plotted to represent the dynamical systems of the flows and to analyze mixing. The flow systems become globally chaotic as the groove depth increases above a threshold value. Fouling mitigation via chaotic advection is demonstrated using the dimensionless average concentration (c¯w*) on the membrane and its growth rate. When the flow system is chaotic, the growth rate of c¯w* drops significantly compared to that predicted from the film theory, demonstrating that chaotic advection is an attractive hydrodynamic technique that mitigates membrane fouling. At each Re, there exists an optimal groove depth minimizing c¯w* and the growth rate of c¯w*. Under the optimum groove geometry, foulants near the membrane are transported back to the bulk flow via the downwelling flows, distributed uniformly in the entire channel via chaotic advection.

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Chen, Yong Li, et Shu Yong Lv. « Research on Wideband Guiding System Receiving Technology ». Applied Mechanics and Materials 214 (novembre 2012) : 862–66. http://dx.doi.org/10.4028/www.scientific.net/amm.214.862.

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The ultra-high speed data acquisition system is introduced, which has sampling rate of 3GSPS. The design scheme of hardware circuit is given in condition to analyze the theory and technology of signal sampling. The design of the main part circuit is described. The module of serial -parallel conversion and FFT spectrum analysis are designed in software realization. The system has strong commonality because of application of the ADC + FPGA + DSP framework.

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Seok, Min-Gwang, Yangdo Kim et Soo Min Kim. « Reaction Kinetics Analysis of Treatment Process on Light-Induced Degradation for p-Type Passivated Emitter and Rear Contact Solar Cell Module with Gallium Cz-Si Wafer ». Energies 15, n^o 10 (12 mai 2022) : 3563. http://dx.doi.org/10.3390/en15103563.

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The light-induced degradation (LID) phenomenon in solar cells reduces power generation output. Previously, a method was developed to prevent LID where a group III impurity that can replace boron is added to the silicon wafer. However, in a subsequent study, performance degradation was observed in gallium-doped solar wafers and cells, and a degradation pattern similar to that occurring in light and elevated temperature-induced degradation (LeTID) was reported. In this study, a 72-cell module was fabricated using gallium-doped PERC cells, and the treatment of the LID process for carrier injection in the range of 1 to 7 A at 130 °C was analyzed using kinetic theory. We selectively heated only the solar cells inside a 72-cell module using a half-bridge resonance circuit for remote heating. To monitor the treatment of LID process in real time, a custom multimeter manufactured using an ACS758 current sensor and a microcomputer was used. Least-squares curve fitting was performed on the measured data using a reaction kinetics model. When the carrier-injection condition was applied to the gallium-doped PERC solar cell module at a temperature of 130 °C, the observed degradation and treatment pattern were similar to LeTID. We assumed that the treatment rate would increase as the size of the injected carrier increased; however, the 5 A condition exhibited the fastest treatment rate. It was deduced that the major factors of change in the overall treatment of the LID process vary depending on the rate of conversion from the LID state to the treatment state. In conclusion, it can be expected that the deterioration state of the gallium-doped solar cell module changes due to the treatment rate that varies depending on the carrier-injection conditions.

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Sun, Zhuangzhuang, Yunlin Song, Qing Li, Jian Cai, Xiao Wang, Qin Zhou, Mei Huang et Dong Jiang. « An Integrated Method for Tracking and Monitoring Stomata Dynamics from Microscope Videos ». Plant Phenomics 2021 (9 avril 2021) : 1–11. http://dx.doi.org/10.34133/2021/9835961.

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Patchy stomata are a common and characteristic phenomenon in plants. Understanding and studying the regulation mechanism of patchy stomata are of great significance to further supplement and improve the stomatal theory. Currently, the common methods for stomatal behavior observation are based on static images, which makes it difficult to reflect dynamic changes of stomata. With the rapid development of portable microscopes and computer vision algorithms, it brings new chances for stomatal movement observation. In this study, a stomatal behavior observation system (SBOS) was proposed for real-time observation and automatic analysis of each single stoma in wheat leaf using object tracking and semantic segmentation methods. The SBOS includes two modules: the real-time observation module and the automatic analysis module. The real-time observation module can shoot videos of stomatal dynamic changes. In the automatic analysis module, object tracking locates every single stoma accurately to obtain stomatal pictures arranged in time-series; semantic segmentation can precisely quantify the stomatal opening area (SOA), with a mean pixel accuracy (MPA) of 0.8305 and a mean intersection over union (MIoU) of 0.5590 in the testing set. Moreover, we designed a graphical user interface (GUI) so that researchers could use this automatic analysis module smoothly. To verify the performance of the SBOS, the dynamic changes of stomata were observed and analyzed under chilling. Finally, we analyzed the correlation between gas exchange and SOA under drought stress, and the correlation coefficients between mean SOA and net photosynthetic rate (Pn), intercellular CO2 concentration (Ci), stomatal conductance (Gs), and transpiration rate (Tr) are 0.93, 0.96, 0.96, and 0.97.

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Karmiloff-Smith, Annette, Edward Klima, Ursula Bellugi, Julia Grant et Simon Baron-Cohen. « Is There a Social Module ? Language, Face Processing, and Theory of Mind in Individuals with Williams Syndrome ». Journal of Cognitive Neuroscience 7, n^o 2 (avril 1995) : 196–208. http://dx.doi.org/10.1162/jocn.1995.7.2.196.

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Many species can respond to the behavior of their conspecifics. Human children, and perhaps some nonhuman primates, also have the capacity to respond to the mental states of their conspecifics, i.e., they have a “theory of mind.” On the basis of previous research on the theory-of-mind impairment in people with autism, together with animal models of intentionality, Brothers and Ring (1992) postulated a broad cognitive module whose function is to build representations of other individuals. We evaluate the details of this hypothesis through a series of experiments on language, face processing, and theory of mind carried out with subjects with Williams syndrome, a rare genetic neurodevelopmental disorder resulting in an uneven lin-guisticocognitive profile. The results are discussed in terms of how the comparison of different phenotypes (e.g., Williams syndrome, Down syndrome, autism, and hydrocephaly with associated myelomeningocele) can contribute both to understanding the neuropsychology of social cognition and to current thinking about the purported modularity of the brain.

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Zhengtong, LU, LI Shiqiang, WU Yingjun, SUN Lu, CHEN Guozhi et PENG Weilong. « Research on New Energy Grid Control Technology ». E3S Web of Conferences 53 (2018) : 01003. http://dx.doi.org/10.1051/e3sconf/20185301003.

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Aiming at the poor waveform quality of the new energy grid connected under the traditional PI control strategy, based on the theory of repetitive control method, a compound control trategy is proposed. Through the analysis of the compound control module and simulation, the results show that grid harmonic distortion rate can be reduced about 2% at the same nonlinear load, the compound control strategy can suppress the load disturbance signal effectively, and the simulation results demonstrate the effectiveness of the proposed method.

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Yan, Zheng Feng, et Wen Jun Liu. « Research on Design Theory and Experimental Validation of Dry Friction Automotive Clutch Based on Failure Mechanism ». Key Engineering Materials 531-532 (décembre 2012) : 673–78. http://dx.doi.org/10.4028/www.scientific.net/kem.531-532.673.

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As a key component of vehicle, automotive clutch remained high failure rate, meanwhile, with the development of engine and vehicle technology, functional characteristics of automotive clutch such as comfort, durability and reliability demanded much higher. Objective of the study is to establish the correspondence relationship between failures and design theory and experimental methods, reduce failure rate and improve product reliability. In order to create a system approach of problem-solving, we collected clutch failure information and classified according to clutch functional requirements and mechanical design principles. Then we used RCA (root cause analysis) and quality management tools to analyze the cause of failures, used QFD (quality function development) and DFMEA (design failure mode effects analysis) method to protocol the corresponding control measures to improve the existing design theory and experimental methods. The study also can be applied to more complex systems such as dry dual clutch module and dual-mass flywheel damper.

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Zhang, Junfeng, Yutong Chen et Liwei Zhang. « Thermal simulation analysis of power module of combined converter for metro vehicle ». Journal of Physics : Conference Series 2591, n^o 1 (1 septembre 2023) : 012062. http://dx.doi.org/10.1088/1742-6596/2591/1/012062.

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Abstract In order to reduce the occupancy space and equipment cost of the on-board converter, a combined traction-auxiliary converter for subway vehicles is proposed in this paper. The power loss of the main traction converter module (MCM) and the auxiliary converter module (ACM) was calculated according to the speed and power variation of the vehicle running between five consecutive stations, and the flow rate of cooling air was calculated through the heat balance theory. The air volume of MCM and ACM and the plate temperature of the radiator are analysed by step method. Then, according to the instantaneous maximum temperature of the radiator obtained by simulation and the thermal parameters of the IGBT module, the junction temperature of the IGBT and diode chips is calculated by means of the junction temperature equivalent circuit. The results show that the plate temperature of the heat sink and junction temperature meet the design requirements. The design and thermal simulation method in this paper provide theoretical reference for the design of railway vehicle converters.

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Faizal, Khoirunnisa et Hendra Budiono. « Modules Based on Technological Pedagogical Content Knowledge to Improve Elementary Students' Science Domain ». International Journal of Elementary Education 7, n^o 4 (28 décembre 2023) : 616–25. http://dx.doi.org/10.23887/ijee.v7i4.69193.

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The use of teaching modules based on technological pedagogical content knowledge has not been used to the maximum because teachers are still focused only on the theory. The purpose of this research is to produce a teaching module based on TPACK in order to improve the science domain of elementary school students. This research approach is a mix method with the type of Research and Development using the ADDIE development model. The qualification test covers the level of validity and practicality. Data collection tools use validity and practicality lifts. The data in this study is both quantitative and qualitative. The product validation results showed a validation rate of 94.29% for high validity categories. As for the media validity rate of 96% for High validity Categories, the material validation of 98% for higher validity, and the language validation for 88.89% for the High Validity Category. The practicality rate of 85.72% for the Good Practical Category, the teacher's response to 82% of the category was very Practical and the student's reply to 89.44% of the Category was Very Practice. The results of the research show that the teaching module based on technological pedagogical content knowledge (TPACK) to improve the science domain of elementary school students deserves to be used in the learning process.

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Quan, Daying, Zeyu Tang, Xiaofeng Wang, Wenchao Zhai et Chongxiao Qu. « LPI Radar Signal Recognition Based on Dual-Channel CNN and Feature Fusion ». Symmetry 14, n^o 3 (14 mars 2022) : 570. http://dx.doi.org/10.3390/sym14030570.

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The accuracy of low probability of intercept (LPI) radar waveform recognition is an important and challenging problem in electronic warfare. Aiming at the problem of the difficulty in feature extraction and the low recognition rates of the LPI radar signal under a low signal-to-noise ratio, and inspired by the symmetry theory, we propose a new approach for the LPI radar signal recognition method based on a dual-channel convolutional neural network (CNN) and feature fusion. Our new approach contains three main modules: the preprocessing module that converts the LPI radar waveforms into two-dimensional time-frequency images using the Choi–Williams distribution (CWD) transformation and performs image binarization, the feature extraction module that extracts different features obtained from the images, and the recognition module that utilizes a multi-layer perceptron (MLP) network to fuse these features and distinguish the type of LPI radar signals. In the feature extraction module, a two-channel CNN model is proposed that extracts Histogram of Oriented Gradients (HOG) features and deep features from time-frequency images, respectively. Finally, the recognition module recognizes the radar signals using a Softmax classifier based on the fused features from two channels. The experimental results from 12 types of LPI radar signals prove the superiority and robustness of the proposed model. Its overall recognition rate reaches 97% when the signal-to-noise ratio is −6 dB.

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Li, Zhiqi. « Evolution of fatigue damage in solar cells ». IOP Conference Series : Earth and Environmental Science 984, n^o 1 (1 février 2022) : 012011. http://dx.doi.org/10.1088/1755-1315/984/1/012011.

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Abstract Based on the theory of the damage mechanics, the fatigue damage evolution of the solar cells in the photovoltaic module under cyclic load was established. The results from the present model were compared with that of the experiment, and showed that the model can well describe the damage evolution of solar cells, i.e., the damage accumulation is nonlinear. At the initial stage of cyclic load the damage of the cells developed fast, and the growth rate of damage slows down with the increase of the number of cycles.

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Naidoo, Richard, et Jane Ramanamane. « Developing a Model for the Teaching and Learning of Fluid Mechanics at an Open Distance University ». EDEN Conference Proceedings, n^o 1 (21 octobre 2020) : 398–403. http://dx.doi.org/10.38069/edenconf-2020-rw-0043.

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The study explores the developing of a model for the teaching and learning fluid mechanics at open distance university. Most of the students are employed. The model emphases blended learning, flexible learning and student-cantered learning. Fluid mechanics it a module offered at first level of mechanical engineering, which consists of two formative assessment, one submissive assessment and laboratory assignment. This study employed an activity theory as a framework. The quantitative approach was used to collect data. Data consists of student’s assignments (theory and practical) final examination scores. The results indicated average pass rates during 2015 and 2017. However, the pass rates during 2016 was good. It is recommended that cognitive analysis of the student responses could improve the performance rate, quality and enhancement to teaching and learning.

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Peng, Peng, Qingkuan Wang, Weike Feng, Tong Wang et Chuangming Tong. « An SAR Imaging and Detection Model of Multiple Maritime Targets Based on the Electromagnetic Approach and the Modified CBAM-YOLOv7 Neural Network ». Electronics 12, n^o 23 (28 novembre 2023) : 4816. http://dx.doi.org/10.3390/electronics12234816.

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This paper proposes an Synthetic Aperture Radar (SAR) imaging and detection model of multiple targets at the maritime scene. The sea surface sample is generated according to the composite rough surface theory. The SAR imaging model is constructed based on a hybrid EM calculation approach with the fast ray tracing strategy and the modified facet Small Slope Approximation (SSA) solution. Numerical simulations calculate the EM scattering and the SAR imaging of the multiple cone targets above the sea surface, with the scattering mechanisms analyzed and discussed. The SAR imaging datasets are then set up by the SAR image simulations. A modified YOLOv7 neural network with the Spatial Pyramid Pooling Fast Connected Spatial Pyramid Convolution (SPPFCSPC) module, Convolutional Block Attention Module (CBAM), modified Feature Pyramid Network (FPN) structure and extra detection head is developed. In the training process on our constructed SAR datasets, the precision rate, recall rate, mAP@0.5 and mAP@0.5:0.95 are 97.46%, 90.08%, 92.91% and 91.98%, respectively, after 300 rounds of training. The detection results show that the modified YOLOv7 has a good performance in selecting the targets out of the complex sea surface and multipath interference background.

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Álvarez-Martínez, Jonathan U., Orlando M. Medina-Cázares, Maria E. Soto-Alcaraz, Ramón Castañeda-Priego, G. Gutiérrez-Juárez et R. Castro-Beltrán. « Microfluidic system manufacturing by direct laser writing for the generation and characterization of microdroplets ». Journal of Micromechanics and Microengineering 32, n^o 6 (13 avril 2022) : 065001. http://dx.doi.org/10.1088/1361-6439/ac628d.

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Abstract This work contributes to the development of microfluidics devices in a simpler way and by keeping the cost of microfabrication as low as possible. Implementing methods to develop microfluidic devices and to have control over the channel size rapidly and easily have become a challenge. In the present work, direct laser writing (DLW) is proposed as a manufacturing technique to develop a T-junction microfluidic droplet generator operating in the squeezing regime. Owing to the channel size, DLW depends on both the focused laser spot properties and the interface material refractive indices. The Debye–Wolf theory behind this technique predicts the focal shift of the laser spot to avoid optical misalignment during the fabrication process. The Debye–Wolf theory and the COMSOL ray-tracing module are presented as complementary design tools. The flow rates and the channel sizes were investigated under the two-phase COMSOL module. Experimental droplet generation results were assisted with the solution of the Navier–Stokes equation with appropriate boundary conditions. Microdroplet size characterization, as well as simulations, show a linear tendency with the flow rate ratios (FRRs). For FRR ranging from 0.25 to 2, droplet lengths from ∼ 320 μ m to ∼ 1050 μ m were observed. This information is confirmed by implementing a digital image processing protocol. The dynamics of droplets formation, strongly influenced by the input flow rate fluctuations caused by the syringes and micropump operation, are presented. This protocol aims the full control of these devices to perform potential applications, such as particle insulators, drug delivery, fluidic microlasers, among others.

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Tandon, Abhishek, Neha, Anu G. Aggarwal et Ajay Jaiswal. « Reliability Assessment of Software System Using IFS and OWA-Tree Analysis ». International Journal of Reliability, Quality and Safety Engineering 27, n^o 05 (7 avril 2020) : 2040013. http://dx.doi.org/10.1142/s0218539320400136.

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To address the software design and development, reliability assessment is considered as crucial and most important task. Several studies have been directed towards reliability assessment approaches for obtaining highly reliable software product. In conventional reliability theory, failure probability of any component is assumed as an exact value but in actuality it’s not possible to get failure probability precisely. In this study, we have proposed an approach to assess the reliability of a software system with vague failure rate of the components as the given information might be incomplete or uncertain. It is a bottom–top methodology which includes the combination of intuitionistic fuzzy set (IFS) theory and ordered weighted averaging (OWA) tree analysis. Using IFS, we are able to come over the vagueness in the failure rate data and by using OWA-tree, we incorporate the subjectivity in the opinion of software developers with respect to selection of module. Further, for the illustration of the proposed approach one numerical example has been discussed and software reliability is assessed based upon different orness level.

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Yoon, Sukmin, Young-Joo Lee, Seong-Su Kim, Han-Bong Choi et No-Suk Park. « Research on Autopsy Results of over 10 Year Old Low Pressure Hollow Fiber Membrane from Domestic Water Treatment Plant ». Journal of Korean Society of Environmental Engineers 44, n^o 9 (30 septembre 2022) : 287–97. http://dx.doi.org/10.4491/ksee.2022.44.9.287.

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Objectives : In this study, membrane autopsy was performed for a parallel arrayed low-pressure membrane (microfiltration) filtration process that is actually applied to water treatment, to check out whether there are differences in the degree of membrane fouling due to the uneven flow rate into each module. Also, membrane foulants were evaluated quantitatively.Methods : In this study, autopsy was performed for over 10 year old membranes used for drinking water purification. In this way, the outer casings of membrane modules at different positions were disassembled and visually observed. In addition, In addition, the size of the pores and the porosity were investigated by taking a SEM (Scanning Electron Microscope) photograph for the new and the used membrane module fiber samples in different positions from the header pipe. The used membrane foulants were classified into organic and inorganic matters and quantitatively analyzed.Results and Discussion : As a result of visually observing inside the membrane module that has produced drinking water for over 10 years, the inside of the No. 1 membrane module close to the inlet was contaminated with black foulants. On the other hand, in the case of No. 10 membrane module located farthest from the header pipe inlet, no foulants were observed with the naked eye. Also, it was observed from SEM photograph results that there were large differences in the surfaces among No. 1, 4, 6, 8 and 10 MF module fibers.Conclusion : Even after periodic physical and chemical cleaning, it was concluded that the fouling levels were different each other in the parallel arrayed low-pressure membrane modules. In addition, the pore size distribution and porosities of the membrane modules may vary depending on the position.

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Chen, Jui-Ho, et Hsi-Chun Wang. « Metal-Organic Framework Synthesis System Based on Fuzzy Predictive Control via Network Transmission ». Mathematical Problems in Engineering 2014 (2014) : 1–13. http://dx.doi.org/10.1155/2014/105289.

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The purpose of this study is to construct metal-organic framework (MOF) synthesis heating systems based on fuzzy method for monitoring and automatic control. In this study, the temperature sensing module for measurements sensed values that it through a wireless ZigBee chips and wired DAQ device for real-time data transmission. Because MOF synthesis, often due to different modes of heating or heating instability caused by its nucleation and crystal growth rate, is an important influence, leading to different crystallinity, the use of fuzzy theory to predict the temperature parameter and instant heating MOF synthesis parameters can be adjusted to improve the accuracy of the system. The research system to RS-232 interface module for infrared emission control packets issued and automated control of the furnace through the infrared receiver module. This study is based on a terminal interface window of Visual Basic programming and LabView graphical diagram for control system design. Finally, this research, through a number of experiments to validate the use of fuzzy system development methods and networks, can improve the accuracy of the reaction efficiency MOF sensing and control the heating system.

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Song, Zhiqiang, Bozhi Wang, Zhuo Zhang, Yirong Yu et Dabin Lin. « A Highly Flexible Piezoelectric Ultrasonic Sensor for Wearable Bone Density Testing ». Micromachines 14, n^o 9 (20 septembre 2023) : 1798. http://dx.doi.org/10.3390/mi14091798.

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Driven by the loss of bone calcium, the elderly are prone to osteoporosis, and regular routine checks on bone status are necessary, which mainly rely on bone testing equipment. Therefore, wearable real-time healthcare devices have become a research hotspot. Herein, we designed a high-performance flexible ultrasonic bone testing system using axial transmission technology based on quantitative ultrasound theory. First, a new rare-earth-element-doped PMN-PZT piezoelectric ceramic was synthesized using a solid-state reaction, and characterized by X-ray diffraction and SEM. Both a high piezoelectric coefficient d33 = 525 pC/N and electromechanical coupling factors of k33 = 0.77, kt = 0.58 and kp = 0.63 were achieved in 1%La/Sm-doped 0.17 PMN-0.47 PZ-0.36 PT ceramics. Combining a flexible PDMS substrate with an ultrasonic array, a flexible hardware circuit was designed which includes a pulse excitation module, ultrasound array module, amplification module, filter module, digital-to-analog conversion module and wireless transmission module, showing high power transfer efficiency and power intensity with values of 35% and 55.4 mW/cm2, respectively. Finally, the humerus, femur and fibula were examined by the flexible device attached to the skin, and the bone condition was displayed in real time on the mobile client, which indicates the potential clinical application of this device in the field of wearable healthcare.

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Haberman, B. A., et J. B. Young. « Diffusion and Chemical Reaction in the Porous Structures of Solid Oxide Fuel Cells ». Journal of Fuel Cell Science and Technology 3, n^o 3 (17 janvier 2006) : 312–21. http://dx.doi.org/10.1115/1.2211637.

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The Rolls-Royce integrated-planar solid oxide fuel cell (IP-SOFC) consists of ceramic modules with electrochemical cells printed on the outer surfaces. The cathodes are supplied with oxygen from air flowing over the outside of the module and the anodes are supplied with fuel diffusing from the internal gas channels. Natural gas is reformed into hydrogen in a separate reformer module of similar design except that the fuel cells are replaced by a reforming catalyst layer. The performance of the modules is intrinsically linked to the behavior of the gas flows within their porous structures. The multi-component convective-diffusive flows are simulated using a new theory of flow in porous material, the cylindrical pore interpolation model. The effects of the catalyzed methane reforming and water-gas shift chemical reactions are also considered using appropriate kinetic models. It is found that the shift reaction, which is catalyzed by the anode material, has certain beneficial effects on the fuel cell module performance. The shift reaction enables the fuel cells to make effective use of carbon monoxide as a fuel when the supplied fuel has become depleted of hydrogen. In the reformer module the kinetics of the reaction make it difficult to sustain a high methane conversion rate. Although the analysis is based on IP-SOFC geometry, the modeling approach and general conclusions are applicable to other types of SOFCs.

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Levi, Hagai, Nima Rahmanian, Ran Elkon et Ron Shamir. « The DOMINO web-server for active module identification analysis ». Bioinformatics 38, n^o 8 (9 février 2022) : 2364–66. http://dx.doi.org/10.1093/bioinformatics/btac067.

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Abstract Motivation Active module identification (AMI) is an essential step in many omics analyses. Such algorithms receive a gene network and a gene activity profile as input and report subnetworks that show significant over-representation of accrued activity signal (‘active modules’). Such modules can point out key molecular processes in the analyzed biological conditions. Results We recently introduced a novel AMI algorithm called DOMINO and demonstrated that it detects active modules that capture biological signals with markedly improved rate of empirical validation. Here, we provide an online server that executes DOMINO, making it more accessible and user-friendly. To help the interpretation of solutions, the server provides GO enrichment analysis, module visualizations and accessible output formats for customized downstream analysis. It also enables running DOMINO with various gene identifiers of different organisms. Availability and implementation The server is available at http://domino.cs.tau.ac.il. Its codebase is available at https://github.com/Shamir-Lab.

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Borgonovo, Claudia. « Modales ambiguos ». Revue Romane / Langue et littérature. International Journal of Romance Languages and Literatures 46, n^o 2 (31 décembre 2011) : 202–21. http://dx.doi.org/10.1075/rro.46.2.02bor.

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This article explores the interaction of Tense, Aspect and Modality in French, Italian and Spanish, languages in which Modals are inflected as main verbs. Imperfective modals are a-averidical, as modals are expected to be, but when they appear in a perfective tense, unexpected entailments and implicatures appear. For example, the following example is three-way ambiguous in Spanish; the corresponding example is two way-ambiguous in Italian and French: P. may have won, could have won, managed to win the race The three readings, epistemic, counterfactual and implicative, are derived from the alternative orderings of three heads, Tense, Aspect and Modal; any ordering in which Modal scopes over Tense is out on semantic grounds; these leaves three possible orderings which result in the three readings. In the epistemic construal, Modal has scope over Tense and Aspect, which are read on the infinitive. As a result, Modal Evaluation Time is at Utterance Time and the lower infinitive is Past and Perfective. There is no interaction between Modal and the other two heads and averidicality is the result. In the counterfactual reading,Tense scopes over Modal, which in turn scopes over Aspect: the result is a past Modal Evaluation; Perfective Aspect makes the interval in which verifying instances of the lower event are sought bounded, which contributes settledness. These are the crucial ingredients for counterfactuality. When Tense and Aspect are both read on the modal, the lower event is entailed and an implicative reading ensues. Italian and French do not have the counterfactual reading because their only surviving perfective past is a morphological perfect which, since it involves a resulting state, is incompatible with counterfactuality. Spanish perfecto also lacks this reading.

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Papadopoulos, Iason, et Jiabo Wang. « Polar Codes for Module-LWE Public Key Encryption : The Case of Kyber ». Cryptography 7, n^o 1 (10 janvier 2023) : 2. http://dx.doi.org/10.3390/cryptography7010002.

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In modern society, the Internet is one of the most used means of communication. Thus, secure information transfer is inevitably of major importance. Computers nowadays use encryption methods based on arithmetic operations to turn messages into ciphertexts that are practically impossible for an attacker to reverse-engineer using a classical computer. Lately, it has been proven that this is possible in a post-quantum setting where quantum computers of considerable size are available to attackers. With the advance of technology of quantum computers, it is now more necessary than ever before to construct encryption schemes that cannot be broken either using a classical or a quantum computer. The National Institute of Technology and Standards (NIST) has orchestrated a competition, and numerous encryption schemes have been proposed. The NIST has identified one algorithm to be standardized for the post-quantum era. This algorithm is called CRYSTALS-Kyber and is based on module learning with errors (MLWE). This paper investigates how to apply error correcting codes in order to create some excess decryption failure rate (DFR) and to take advantage of that in order to re-tune Kyber’s parameters in the pursuit of higher security. By applying Polar Codes, Kyber’s security was managed to be increased by 54.4% under a new set of parameters, while keeping the decryption failure rate well below the upper acceptable bound set by the NIST.

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Murugesan, Priyatharishini, et Nirmala Manickam. « An Optimal Feature Extraction using Deep Learning Technique for Trojan Detection and Validation using Game Theory ». International Journal of Intelligent Engineering and Systems 13, n^o 6 (31 décembre 2020) : 318–29. http://dx.doi.org/10.22266/ijies2020.1231.28.

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In modern electronic design, hardware Trojan has emerged as a major threat in the hardware security. To detect the hardware Trojan is a major problem in testing process because of their inherent concealed nature. In this work, we propose a deep learning-based Trojan classification approach, which extracts the optimal feature to indicate the nets affected by the Trojan module. In this approach, a handcrafted algorithm along with the structural report is also analyzed for extracting further features of the gate level netlist, which stamp out the requirement of golden chip. This detection technique is also validated using game theoretical approach, which is modelled as zero-sum game between the attacker and the defender. The Simulation is employed on ISCAS’85, ISCAS’89 and Trust-HUB circuits and the deep learning algorithm performs the best in detection and classification of Trojan type with an average True positive rate of 96.69% and an accuracy of 96.25%.

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Shi, Guolong, Yigang He, Lichuan Gu et Jun Jiao. « Industry 4.0-Oriented Chipless RFID Backscatter Signal Variable Polarization Amplitude Deep Learning Coding ». Wireless Communications and Mobile Computing 2021 (23 septembre 2021) : 1–11. http://dx.doi.org/10.1155/2021/6985420.

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Due to the weak network security protection capabilities of control system network protocols under Industry 4.0, the research on industrial control network intrusion detection is still in its infancy. This article discussed and researched the intrusion prevention technology of industrial control networks based on deep learning. According to the electromagnetic scattering theory, the backscatter signal model of the chipless tag was established as a chipless tag structure. Polarized deep learning coding was used for the label; that was, deep learning coding was performed on the copolarization component and the cross-polarization component at the same time, and a 16-bit deep learning coding bit number was obtained. The wave crest deep learning coding was used for the split ellipse ring patch label, and the 6-bit deep learning coding bit number was obtained. Then, the poles of the scattered signal of the tag were extracted to identify the tag. The variable polarization effect was achieved by adopting the dipole resonant unit with the two ends bent. Aiming at the problem of low detection rate caused by the shallow selection of feature classification of intrusion prevention systems, an industrial control network intrusion prevention model based on self-deep learning encoders and extreme learning machines was proposed to extract features from industrial control network data through deep learning. For accurate classification, the theoretical judgment was also verified through simulation experiments, and it was proved that the detection rate of the model has also improved. It forms a set of industrial control network intrusion prevention system with complete functions and superior performance with data acquisition module, system log module, defense response module, central control module, etc. The matrix beam algorithm was used to extract the poles and residues for the late response, and the extracted poles and residues were used to reconstruct the signal. The reconstructed signal was compared with the scattered signal to verify the correctness of the pole extraction. Finally, the tags were processed and tested in the actual environment, and the measured results were consistent with the theoretical analysis and simulation results.

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Et.al, Abdel Rahman Ibrahim Suleiman Islieh. « Fostering Outstanding Personality among Teacher Trainees through ULUL Albab QEI Module Training ». Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, n^o 3 (10 avril 2021) : 2888–99. http://dx.doi.org/10.17762/turcomat.v12i3.1320.

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Purpose – This study centres on a new cohort of teacher training students in Universiti Pendidikan Sultan Idris (UPSI) who were trained on the attitude and personality development modules organised by the Ulul Albab Centre in the university. The Ulul Albab modules known as QEI (Quranic, Encyclopaedic and Ijtihadik) were introduced and conducted with the participants of Ulul Albab Centre (PUA) programme. The QEI modules cover leadership talent development and soft skills which are considered as the important characteristics of outstanding personality for every future educators and community leaders. A standard questionnaire was distributed to 150 students who were pioneers of the Ulul Albab programme in the university. The participants were also asked to reflect on the various aspects and activities of the programme and modules and their written and verbal responses were analysed using NVivo 12 application. The findings indicated more than 80% approval and satisfaction rate among the participants on the constructive impact of the training on their attitude, personal and soft skills development. Their feedback and personal reflections too indicated positive bearing on their overall attitude having completed all the Ulul Albab modules. The encouraging outcomes are signs of better programme implementation for the new batch of teacher trainees. New ideas and suggestions from the participants’ feedback would be integrated for the improvement of the QEI components for future cohorts and stronger plans ahead for Pusat Ulul Albab UPSI.

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Mosia, Ngaka. « Adaptive Learning Implementation – A Cognitive Description Experiment for First Year Engineering Students at a Distance Education University ». EDEN Conference Proceedings, n^o 1 (21 octobre 2020) : 124–30. http://dx.doi.org/10.38069/edenconf-2020-rw-0014.

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A study was performed on a first year industrial engineering statistics course to improve the statistics pass rate. Statistics is a requisite for other engineering courses. The pass rate for the statistic course was below 50%. The primary purpose is to enable learners to build a capacity to comprehend module content and establish a deeper level of learning that will enable learners to achieve goals and objectives of TL lessons. An intervention program was instructionally designed to develop a personalized and differentiated learning process that breaks down lessons into lower and basic components, for struggling learners, and improves lessons to a complex high level and challenging activities for excelling students. Forty students were considered for the study. Moore’s theory of transactional distance was used as a theoretical framework. The data consisted of exam and assignment scores. A quantitative method was used to analyse the data. Hypothesis testing suggests that the intervention program is significant. The overall pass rates improved by 25%.

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Casselman, W. « Canonical Extensions of Harish-Chandra Modules to Representations of G ». Canadian Journal of Mathematics 41, n^o 3 (1 juin 1989) : 385–438. http://dx.doi.org/10.4153/cjm-1989-019-5.

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Let G be the group of R-rational points on a reductive, Zariskiconnected, algebraic group defined over R, let K be a maximal compact subgroup, and let g be the corresponding complexified Lie algebra of G. It is a curious fault of the current representation theory of G that for technical reasons one very rarely works with representations of G itself, but rather with a certain category of simultaneous representations of g and K. The reasons for this are, roughly speaking, that for a given (g,K)-module of finite length there are clearly any number of overlying rather distinct continuous G-representations, whose ‘essence’ is captured by the (g, K)-module alone. At any rate, this paper will propose a remedy for this inconvenience, and define a category of smooth representations of G of finite length which will, I hope, turn out to be as easy to work with as representations of (g, K) and occasionally much more convenient. It is to be considered a report on what has been to a great extent joint work with Nolan Wallach, and is essentially a sequel to [38].

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Ockelford, Adam. « A Music Module in Working Memory ? Evidence from the Performance of a Prodigious Musical Savant ». Musicae Scientiae 11, n^o 2_suppl (juillet 2007) : 5–36. http://dx.doi.org/10.1177/10298649070110s202.

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This article investigates the possible existence and nature of a “music module” in working memory after Baddeley (1986) and Berz (1995). Evidence is gleaned from the performance of a prodigious musical savant in hearing and playing back an unfamiliar piece. His ability to realise internalised auditory images of considerable complexity on the keyboard with immediacy and an unusual technical facility offers a rare opportunity to glean something of the workings of the musical mind in a direct and ecologically valid way — through purely musical responses. These are subject to an initial musicological analysis using “zygonic” theory (Ockelford, 2005a, 2005b), which seeks to explain how the structure and content of the savant's output is derived from the stimulus and from other sources, and how both are woven into a coherent musical whole. The underlying methodological assumption is that the perceived sonic relationships so identified offer powerful evidence of processes that are hypothesised to underlie the learning, storage and retrieval of musical elements in cognition.

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Abu-Zeid, Mostafa Abd El-Rady, Xiaolong Lu et Shaozhe Zhang. « Enhancement of the air gap membrane distillation system performance by using the water gap module ». Water Supply 20, n^o 7 (13 août 2020) : 2884–902. http://dx.doi.org/10.2166/ws.2020.186.

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Abstract The negative effect of an air gap layer presented between the membrane and cooling plate on air gap membrane distillation (AGMD) performance was diminished largely by inserting a water gap membrane distillation (WGMD) module in series. The new design of air-gap–water-gap membrane distillation (AG-WG)MD was evaluated experimentally by comparing with an AGMD system under different operating conditions. In theory, mass and heat transfer in the new (AG-WG)MD and imitative AGMD systems were analyzed. Experimental outcomes showed that a new (AG-WG)MD design profoundly enhanced flux (Pd) and gained output ratio (GOR), and greatly decreased energy consumption (STEC) and heat input (EH.I). At a concentration of 5,000 mg/L, coolant temperature of 20 °C, and flow rate of 18 L/h, Pd was promoted by 76.26%, 40.84%, 35.45%, 30.91%, and GOR by 46.38%, 33.46%, 31.27%, 26.65%, in addition to STEC being reduced about 55.63%, 46.81%, 43.66%, 38.30%, and EH.I around 31.31%, 25.84%, 23.53%, 20.55%, from the AGMD to (AG-WG)MD system at feed temperatures of 50 °C, 60 °C, 70 °C, and 80 °C, respectively. The outcomes proved that the AGMD performance could be significantly promoted by integrating with WGMD in a combined MD system. This combination increased the temperature difference across the membrane and decreased thermal-concentration boundary layers for the AGMD system.

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Coumans, Juul M. J., Anke Oenema, Catherine A. W. Bolman et Lilian Lechner. « Use and Appreciation of a Web-Based, Computer-Tailored Diet and Physical Activity Intervention Based on the Self-determination Theory : Evaluation Study of Process and Predictors ». JMIR Formative Research 5, n^o 12 (2 décembre 2021) : e22390. http://dx.doi.org/10.2196/22390.

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Background eHealth is a promising tool for promoting lifestyle behaviors such as a healthy diet and physical activity (PA). However, making people use interventions is a crucial and challenging problem in eHealth. More insight into use patterns and predicting factors is needed to improve future interventions. Objective This study aims to examine the use, predictors of use, and appreciation of a web-based, computer-tailored, dietary and PA promotion intervention, MyLifestyleCoach, which is based on the self-determination theory. First, we depict the participants’ flow in the intervention and identify moments when they are likely to discontinue use. Second, we investigate whether demographic, motivational, and program-related characteristics predict the use of several intervention elements. Finally, we report the appreciation scores for the intervention and the participant and program characteristics associated with these scores. Methods This study was based on data from web-based self-report questionnaires. Here, objectively assessed intervention use data were analyzed from participants randomized to the intervention condition. Multiple stepwise (logistic) regression analyses were conducted to examine the predictors of intervention use and evaluation scores. Results Our findings indicate a low full completion rate for the intervention among those who chose and completed the diet module (49/146, 33.6%), the PA module (2/12, 17%), and both modules (58/273, 21.2%). Several points in the intervention where participants were likely to stop using the intervention were identified. Autonomous and intrinsic motivation toward diet were related to the completion of the initial sessions of the intervention (ie, the opening session in which participants could choose which module to follow and the first session of the diet module). In contrast, controlled motivation was linked to the completion of both modules (initial and follow-up sessions). Appreciation scores were somewhat positive. Appreciation was predicted by several motivational constructs, such as amotivation and basic psychological needs (eg, competence) and program-related features (eg, number of completed sessions). Conclusions This study adds meaningful information on the use and appreciation of a web-based, computer-tailored dietary and PA intervention, MyLifestyleCoach. The results indicate that different types of motivations, such as extrinsic and intrinsic motivation, are at play at the points when people are likely to stop using the intervention. The intervention was appreciated fairly well, and several motivational constructs and fulfillment of basic psychological needs were associated with appreciation. Practical implications of these findings have been provided in this study.

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Tian, Dake, Haiming Gao, Lu Jin, Rongqiang Liu, Yu Zhang, Chuang Shi et Jiewei Xu. « Design and kinematic analysis of a multifold rib modular deployable antenna mechanism ». Mechanical Sciences 13, n^o 1 (14 juin 2022) : 519–33. http://dx.doi.org/10.5194/ms-13-519-2022.

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Abstract. Aiming at the urgent need for the development of space deployable antenna with large aperture and a high storage rate, a new configuration of a multifold rib modular deployable antenna mechanism is proposed. The overall structure scheme design of the antenna is carried out, and the structure composition of the module, the principle of structural topology transformation, and the scheme of mechanism deployment and locking are expounded. According to the shape and constraint relationship of the structure deployment and folded state, and based on basic theory of robotics, calculation and the analysis of key structural parameters and the included angle of rib units are carried out, and the parameterized mathematical model is established. The detailed structural design is carried out, and then the complex structures such as the center beam assembly, diagonal beam assembly, and outer beam assembly are introduced in detail. The kinematic simulation of the mechanism is carried out by using ADAMS software, and the variation law of the motion parameters is analyzed. Finally, the prototype of a hexagonal prism single-module principle is developed, and a deployment function test and verification are carried out. The simulation and test results show that the proposed mechanism can realize the motion change from folded to deployed, and no problems such as interference or clamping are observed in deployment, which verifies the correctness and the feasibility of the structural scheme and principle. Moreover, the proposed new configuration scheme not only retains the characteristics of modular structure, such as good universality and easy expansion, but also has a high storage rate and structure efficiency rate. The research results have a high reference value and relevance for basic theoretical research and the engineering application of a space deployable antenna.

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Mellado, Diego, Carolina Saavedra, Steren Chabert, Romina Torres et Rodrigo Salas. « Self-Improving Generative Artificial Neural Network for Pseudorehearsal Incremental Class Learning ». Algorithms 12, n^o 10 (1 octobre 2019) : 206. http://dx.doi.org/10.3390/a12100206.

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Deep learning models are part of the family of artificial neural networks and, as such, they suffer catastrophic interference when learning sequentially. In addition, the greater number of these models have a rigid architecture which prevents the incremental learning of new classes. To overcome these drawbacks, we propose the Self-Improving Generative Artificial Neural Network (SIGANN), an end-to-end deep neural network system which can ease the catastrophic forgetting problem when learning new classes. In this method, we introduce a novel detection model that automatically detects samples of new classes, and an adversarial autoencoder is used to produce samples of previous classes. This system consists of three main modules: a classifier module implemented using a Deep Convolutional Neural Network, a generator module based on an adversarial autoencoder, and a novelty-detection module implemented using an OpenMax activation function. Using the EMNIST data set, the model was trained incrementally, starting with a small set of classes. The results of the simulation show that SIGANN can retain previous knowledge while incorporating gradual forgetfulness of each learning sequence at a rate of about 7% per training step. Moreover, SIGANN can detect new classes that are hidden in the data with a median accuracy of 43 % and, therefore, proceed with incremental class learning.

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Straszko, Jerzy, Wiesław Parus et Wojciech Paterkowski. « Kinetics of catalytic combustion processes of air admixtures / Aspekty kinetyczne procesow katalitycznego spalania domieszek powietrza ». Archives of Environmental Protection 41, n^o 1 (1 mars 2015) : 86–97. http://dx.doi.org/10.1515/aep-2015-0011.

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Abstract A catalytic combustion of organic admixtures of air belongs to the basic technologies of gas purification. A macrokinetics of admixtures combustion over the porous catalysts was described. The theoretical approach is in agreement with standard description of macrokinetics of the catalytic processes. The relationship between the fundamental magnitudes: observed process rate r*, reaction rate r in the kinetic zone, and a coefficient of the surface utilization η in the form r*= r · η have been described. These magnitudes combines the Thiele module φ. A kinetics equation for the isothermal and non-isothermal conditions was provided. The influence of mass and heat transfer in the catalyst grain on the course of the process was described by means of the surface utilization coefficient η. An equation describing this coefficient for both isothermal and non-isothermal conditions was given. The second part of this work concerns the application of theory. When the composition of purified gas is continuously varied, a quantitative approach is rather impossible. The theory was used for the qualitative analysis of process on the basis of the experimental results. A fulfillment of the first-order kinetics means that the degree of admixtures conversion does not depend on their initial concentrations. A non-isothermicity of the catalyst grain is expressed in such a way that the process rate observed over the large porous grains of the catalyst can be higher than the reaction rate in the kinetic zone. A temperature deference between the catalyst grains and flowing gas causes that the reactor can be stably operated at varied concentrations of admixtures and temperature over a relatively wide range. It was also demonstrated that the flammable admixtures may advantageously influence the conversion of hardly combustible admixtures

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Naidoo, Richard, et Mosia Ngaka. « Developing an Innovative Program for First Year Engineering Statistics Students at an Open Distance University ». EDEN Conference Proceedings, n^o 1 (22 juin 2020) : 407–15. http://dx.doi.org/10.38069/edenconf-2020-ac0039.

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A study was performed on a first year industrial engineering statistics course to improve the statistics pass rate. Statistics is a requisite for other engineering courses. The pass rate for the statistic course was below 50%. The primary purpose is to enable learners to build a capacity to comprehend module content and establish a deeper level of learning that will enable learners to achieve goals and objectives of TL lessons. An intervention program was instructionally designed to develop a personalized and differentiated learning process that breaks down lessons into lower and basic cognitive components, for struggling learners. The program improves e‑learning lessons to a complex higher cognitive level and advances challenging activities for excelling students. Forty students were considered for the study. Moore’s theory of transactional distance was used as a theoretical framework. A quantitative method was used to analyse the data. The data consisted of assignment scores. Hypothesis testing at a 95% level of significance suggests that the intervention program made an impact. The overall pass rates improved by 25%.

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LI, YANPING, ZHENMIN TANG, HUI DING et YAN ZHANG. « DISCRIMINATIVE FEATURE EXTRACTION BASED ON SELF-ADAPTIVE FREQUENCY WARPING FOR ROBUST SPEAKER IDENTIFICATION ». International Journal of Information Acquisition 05, n^o 04 (décembre 2008) : 349–58. http://dx.doi.org/10.1142/s0219878908001739.

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This paper presents a new discriminative feature based on self-adaptive frequency warping. We analyze the discrimination power between frequency components and individual characteristics and quantify this dependency. This new feature is extracted by nonuniform sub-band filters designed according to self-adaptive frequency warping in different frequency bands. Furthermore, in order to overcoming the acoustics mismatch between training and testing data in the noise environment, we adopted pre-enhancement prior to feature extracted module. Using a series of controlled experiments, it is shown that the theory of this feature is reasonable and understandable, which is insensitive to spoken content and thus more discriminative and robust in comparison to the conventional Mel frequency cepstral coefficients. The experimental results demonstrate that combining pre-enhancement and discriminative feature leads to noticeable improvement on speaker recognition rate and robustness.

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Xu, Feng Ying, Zhen Chen et Chang You Li. « Research on the Highly Energy-Efficient Conversion and Utilization Path of Solar Energy Demand Type ». Advanced Materials Research 512-515 (mai 2012) : 148–54. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.148.

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In order to promote the highly energy-efficiency utilization level of solar energy demand type, this paper, based on the average radiation within the solar radiation spectrum range and application requirement analysis of quantum theory, investigated the technical bottleneck and solution on the highly energy-efficient storage and conversion of solar energy demand type. Studies showed that the key to highly energy-efficiency utilization was to synthetically promote the utilization rate of energy conversion in each solar area. It could make direct conversion and utilization of solar energy in accordance with easy-preserved type foods, electrical power, fuel and other forms of energy demand, and then conversion route of energy utilization could be cut down and energy losses in the process of transmission could be decreased. Making full use of energy of solar spectrum visible light area to increase the plant photosynthesis, or using catalysis to change the Fermi lever and minimum work function of photocell battery module stripping to strengthen the photo electricity conversion rate could further enhance the conversion rate of highly-efficiency utilization of solar energy demand type. The study was involving multi-field of knowledge, and still need to be integrated innovation with further theoretical research.

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Charafi, My M. « Two-dimensional numerical modeling of sediment transport in a dam reservoir to analyze the feasibility of a water intake ». International Journal of Modern Physics C 30, n^o 01 (janvier 2019) : 1950003. http://dx.doi.org/10.1142/s0129183119500037.

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The present work is related to the study of a water intake projected into a dam reservoir, located in northern Morocco. The object sought is to examine the natural conditions surrounding a water intake and their possible repercussions on its operation. Thus, a two-dimensional numerical model is developed to simulate the sediment transport in a reservoir dam. The developed model consists of hydrodynamic module based on the Saint–Venant equations and sediment transport module based on the mass-balance equation, where there are resolved by a MacCormack numerical scheme and upwind scheme, respectively. The analysis using the numerical model has made it possible to predict the shutdown periods of the drinking water production station with respect to the rate of suspended solids (SS) for extreme rainfall events.

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