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Zhao, Yulin, Donghui Wang, and Leiou Wang. "Convolution Accelerator Designs Using Fast Algorithms." Algorithms 12, no. 5 (May 27, 2019): 112. http://dx.doi.org/10.3390/a12050112.
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Convolutional neural networks (CNNs) have achieved great success in image processing. However, the heavy computational burden it imposes makes it difficult for use in embedded applications that have limited power consumption and performance. Although there are many fast convolution algorithms that can reduce the computational complexity, they increase the difficulty of practical implementation. To overcome these difficulties, this paper proposes several convolution accelerator designs using fast algorithms. The designs are based on the field programmable gate array (FPGA) and display a better balance between the digital signal processor (DSP) and the logic resource, while also requiring lower power consumption. The implementation results show that the power consumption of the accelerator design based on the Strassen–Winograd algorithm is 21.3% less than that of conventional accelerators.
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Galdeckiy, Anatoliy. "On Prospects of Output Power Increasing in Low-Voltage Multibeam Klystrons for Electron Accelerators." Infocommunications and Radio Technologies 5, no. 1 (March 25, 2022): 93–100. http://dx.doi.org/10.29039/2587-9936.2022.05.1.07.
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Physical principles of output power limitation in low-voltage multibeam klystrons are considered. It is demonstrated that metamaterial consisting of array of metal inductive inserts and located in the cavity’s interaction region makes possible significant increasing of phase velocity of transversal wave in the gap. This reveals the opportunity to enhance uniformity of the RF field interacting with the beams in the gap, interaction region diameter, beams current and power of the klystron without cathode voltage increase. Resonators in S and Ka bands are analyzed.
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Zimek, Zbigniew. "Economical evaluation of radiation processing with high-intensity X-rays." Nukleonika 65, no. 3 (September 1, 2020): 167–72. http://dx.doi.org/10.2478/nuka-2020-0027.
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AbstractX-rays application for radiation processing was introduced to the industrial practice, and in some circumstances is found to be more economically competitive, and offer more flexibility than gamma sources. Recent progress in high-power accelerators development gives opportunity to construct and apply reliable high-power electron beam to X-rays converters for the industrial application. The efficiency of the conversion process depends mainly on electron energy and atomic number of the target material, as it was determined in theoretical predictions and confirmed experimentally. However, the lower price of low-energy direct accelerators and their higher electrical efficiency may also have certain influence on process economy. There are number of auxiliary parameters that can effectively change the economical results of the process. The most important ones are as follows: average beam power level, spare part cost, and optimal shape of electron beam and electron beam utilization efficiency. All these parameters and related expenses may affect the unit cost of radiation facility operation and have a significant influence on X-ray process economy. The optimization of X-rays converter construction is also important, but it does not depend on the type of accelerator. The article discusses the economy of radiation processing with high-intensity of X-rays stream emitted by conversion of electron beams accelerated in direct accelerator (electron energy 2.5 MeV) and resonant accelerators (electron energy 5 MeV and 7.5 MeV). The evaluation and comparison of the costs of alternative technical solutions were included to estimate the unit cost of X-rays facility operation for average beam power 100 kW.
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Barbareschi, Mario, Salvatore Barone, and Nicola Mazzocca. "Advancing synthesis of decision tree-based multiple classifier systems: an approximate computing case study." Knowledge and Information Systems 63, no. 6 (April 12, 2021): 1577–96. http://dx.doi.org/10.1007/s10115-021-01565-5.
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AbstractSo far, multiple classifier systems have been increasingly designed to take advantage of hardware features, such as high parallelism and computational power. Indeed, compared to software implementations, hardware accelerators guarantee higher throughput and lower latency. Although the combination of multiple classifiers leads to high classification accuracy, the required area overhead makes the design of a hardware accelerator unfeasible, hindering the adoption of commercial configurable devices. For this reason, in this paper, we exploit approximate computing design paradigm to trade hardware area overhead off for classification accuracy. In particular, starting from trained DT models and employing precision-scaling technique, we explore approximate decision tree variants by means of multiple objective optimization problem, demonstrating a significant performance improvement targeting field-programmable gate array devices.
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Wolfenden, Joseph, Alexandra S. Alexandrova, Frank Jackson, Storm Mathisen, Geoffrey Morris, Thomas H. Pacey, Narender Kumar, Monika Yadav, Angus Jones, and Carsten P. Welsch. "Cherenkov Radiation in Optical Fibres as a Versatile Machine Protection System in Particle Accelerators." Sensors 23, no. 4 (February 16, 2023): 2248. http://dx.doi.org/10.3390/s23042248.
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Machine protection systems in high power particle accelerators are crucial. They can detect, prevent, and respond to events which would otherwise cause damage and significant downtime to accelerator infrastructure. Current systems are often resource heavy and operationally expensive, reacting after an event has begun to cause damage; this leads to facilities only covering certain operational modes and setting lower limits on machine performance. Presented here is a new type of machine protection system based upon optical fibres, which would be complementary to existing systems, elevating existing performance. These fibres are laid along an accelerator beam line in lengths of ∼100 m, providing continuous coverage over this distance. When relativistic particles pass through these fibres, they generate Cherenkov radiation in the optical spectrum. This radiation propagates in both directions along the fibre and can be detected at both ends. A calibration based technique allows the location of the Cherenkov radiation source to be pinpointed to within 0.5 m with a resolution of 1 m. This measurement mechanism, from a single device, has multiple applications within an accelerator facility. These include beam loss location monitoring, RF breakdown prediction, and quench prevention. Detailed here are the application processes and results from measurements, which provide proof of concept for this device for both beam loss monitoring and RF breakdown detection. Furthermore, highlighted are the current challenges for future innovation.
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Langerman, David, and Alan George. "Real-time, High-resolution Depth Upsampling on Embedded Accelerators." ACM Transactions on Embedded Computing Systems 20, no. 3 (April 2021): 1–22. http://dx.doi.org/10.1145/3436878.
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High-resolution, low-latency apps in computer vision are ubiquitous in today’s world of mixed-reality devices. These innovations provide a platform that can leverage the improving technology of depth sensors and embedded accelerators to enable higher-resolution, lower-latency processing for 3D scenes using depth-upsampling algorithms. This research demonstrates that filter-based upsampling algorithms are feasible for mixed-reality apps using low-power hardware accelerators. The authors parallelized and evaluated a depth-upsampling algorithm on two different devices: a reconfigurable-logic FPGA embedded within a low-power SoC; and a fixed-logic embedded graphics processing unit. We demonstrate that both accelerators can meet the real-time requirements of 11 ms latency for mixed-reality apps. 1
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Freda, Robert, Bradford Knight, and Siddharth Pannir. "A Theory for Power Extraction from Passive Accelerators and Confined Flows." Energies 13, no. 18 (September 16, 2020): 4854. http://dx.doi.org/10.3390/en13184854.
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No accepted fluid theory exists for power extraction from unpressurized confined flow. The absence of a valid model to determine baseline uniform power extraction in confined flows creates difficulties in characterizing the coefficient of power. Currently, the primary body of research has been limited to Diffuser Augmented Wind Turbines (DAWTs) and passive fluid accelerators. Fluid power is proportional to the cube of velocity; therefore, passive acceleration is a promising path to effective renewable energy. Hypothetical models and experiments for passive accelerators yield low ideal power limits and poor performance, respectively. We show that these results derive from the misapplication of Betz’s Law and lack of a general theory for confined flow extraction. Experimental performance is due to the low efficiency of DAWTs and prior hypotheses exhibit high predictive error and continuity violations. A fluid model that accurately predicts available data and new experimental data, showing disk specific maximum CP for the confined channel at 38% of power available to disk, is presented. This is significantly lower than the 59% Betz freestream limit yielded by hypothetical models when the area ratio equals one. Experiments and their results are presented with non-DAWT accelerators, where new experimental results exceed CP limits predicted previously and correlate with the proposed predictive model.
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Tian, Shuo, Lei Wang, Shi Xu, Shasha Guo, Zhijie Yang, Jianfeng Zhang, and Weixia Xu. "A Systolic Accelerator for Neuromorphic Visual Recognition." Electronics 9, no. 10 (October 15, 2020): 1690. http://dx.doi.org/10.3390/electronics9101690.
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Advances in neuroscience have encouraged researchers to focus on developing computational models that behave like the human brain. HMAX is one of the potential biologically inspired models that mimic the primate visual cortex’s functions and structures. HMAX has shown its effectiveness and versatility in multi-class object recognition with a simple computational structure. It is still a challenge to implement the HMAX model in embedded systems due to the heaviest computational S2 phase of HMAX. Previous implementations such as CoRe16 have used a reconfigurable two-dimensional processing element (PE) array to speed up the S2 layer for HMAX. However, the adder tree mechanism in CoRe16 used to produce output pixels by accumulating partial sums in different PEs increases the runtime for HMAX. To speed up the execution process of the S2 layer in HMAX, in this paper, we propose SAFA (systolic accelerator for HMAX), a systolic-array based architecture to compute and accelerate the S2 stage of HMAX. Using the output stationary (OS) dataflow, each PE in SAFA not only calculates the output pixel independently without additional accumulation of partial sums in multiple PEs, but also reduces the multiplexers applied in reconfigurable accelerators. Besides, data forwarding for the same input or weight data in OS reduces the memory bandwidth requirements. The simulation results show that the runtime of the heaviest computational S2 stage in HMAX model is decreased by 5.7%, and the bandwidth required for memory is reduced by 3.53 × on average by different kernel sizes (except for kernel = 12) compared with CoRe16. SAFA also obtains lower power and area costs than other reconfigurable accelerators from synthesis on ASIC.
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Haugen, K. L., K. Papastergiou, P. Asimakopoulos, and D. Peftitsis. "High precision scalable power converter for accelerator magnets." Journal of Instrumentation 17, no. 03 (March 1, 2022): C03021. http://dx.doi.org/10.1088/1748-0221/17/03/c03021.
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Abstract The lower conduction power losses and the positive temperature coefficient that favours parallel connections, make Silicon Carbide (SiC) Metal Oxide Semiconductor Field-Effect Transistors (MOSFETs) to be an excellent replacement of existing Silicon Insulated Gate Bipolar Transistors (IGBTs) technology. These characteristics combined with high switching frequency operation, enables the design of high-accuracy DC-DC converters with minimised filtering requirements. This paper investigates the design for a converter with high-accuracy current (0.9 ppm) supplying a 0.05 H electromagnetic load, aiming to achieve the accuracy without the use of active filters, by using SiC MOSFETs and a scalable module-based converter design.
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Shin, Isu, Jongsang Son, Soonjae Ahn, Jeseong Ryu, Sunwoo Park, Jongman Kim, Baekdong Cha, Eunkyoung Choi, and Youngho Kim. "A Novel Short-Time Fourier Transform-Based Fall Detection Algorithm Using 3-Axis Accelerations." Mathematical Problems in Engineering 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/394340.
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The short-time Fourier transform- (STFT-) based algorithm was suggested to distinguish falls from various activities of daily living (ADLs). Forty male subjects volunteered in the experiments including three types of falls and four types of ADLs. An inertia sensor unit attached to the middle of two anterior superior iliac spines was used to measure the 3-axis accelerations at 100 Hz. The measured accelerations were transformed to signal vector magnitude values to be analyzed using STFT. The powers of low frequency components were extracted, and the fall detection was defined as whether the normalized power was less than the threshold (50% of the normal power). Most power was observed at the frequency band lower than 5 Hz in all activities, but the dramatic changes in the power were found only in falls. The specificity of 1–3 Hz frequency components was the best (100%), but the sensitivity was much smaller compared with 4 Hz component. The 4 Hz component showed the best fall detection with 96.9% sensitivity and 97.1% specificity. We believe that the suggested algorithm based on STFT would be useful in the fall detection and the classification from ADLs as well.
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Papini, Giorgio. "Maximal acceleration and radiative processes." Modern Physics Letters A 30, no. 31 (September 14, 2015): 1550166. http://dx.doi.org/10.1142/s0217732315501667.
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We derive the radiation characteristics of an accelerated, charged particle in a model due to Caianiello in which the proper acceleration of a particle of mass [Formula: see text] has the upper limit [Formula: see text]. We find two power laws, one applicable to lower accelerations, the other more suitable for accelerations closer to [Formula: see text] and to the related physical singularity in the Ricci scalar. Geometrical constraints and power spectra are also discussed. By comparing the power laws due to the maximal acceleration (MA) with that for particles in gravitational fields, we find that the model of Caianiello allows, in principle, the use of charged particles as tools to distinguish inertial from gravitational fields locally.
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Vranjkovic, Vuk, Predrag Teodorovic, and Rastislav Struharik. "Universal Reconfigurable Hardware Accelerator for Sparse Machine Learning Predictive Models." Electronics 11, no. 8 (April 8, 2022): 1178. http://dx.doi.org/10.3390/electronics11081178.
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This study presents a universal reconfigurable hardware accelerator for efficient processing of sparse decision trees, artificial neural networks and support vector machines. The main idea is to develop a hardware accelerator that will be able to directly process sparse machine learning models, resulting in shorter inference times and lower power consumption compared to existing solutions. To the author’s best knowledge, this is the first hardware accelerator of this type. Additionally, this is the first accelerator that is capable of processing sparse machine learning models of different types. Besides the hardware accelerator itself, algorithms for induction of sparse decision trees, pruning of support vector machines and artificial neural networks are presented. Such sparse machine learning classifiers are attractive since they require significantly less memory resources for storing model parameters. This results in reduced data movement between the accelerator and the DRAM memory, as well as a reduced number of operations required to process input instances, leading to faster and more energy-efficient processing. This could be of a significant interest in edge-based applications, with severely constrained memory, computation resources and power consumption. The performance of algorithms and the developed hardware accelerator are demonstrated using standard benchmark datasets from the UCI Machine Learning Repository database. The results of the experimental study reveal that the proposed algorithms and presented hardware accelerator are superior when compared to some of the existing solutions. Throughput is increased up to 2 times for decision trees, 2.3 times for support vector machines and 38 times for artificial neural networks. When the processing latency is considered, maximum performance improvement is even higher: up to a 4.4 times reduction for decision trees, a 84.1 times reduction for support vector machines and a 22.2 times reduction for artificial neural networks. Finally, since it is capable of supporting sparse classifiers, the usage of the proposed hardware accelerator leads to a significant reduction in energy spent on DRAM data transfers and a reduction of 50.16% for decision trees, 93.65% for support vector machines and as much as 93.75% for artificial neural networks, respectively.
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Ngo, Vinh, David Castells-Rufas, Arnau Casadevall, Marc Codina, and Jordi Carrabina. "Low-Power Pedestrian Detection System on FPGA." Proceedings 31, no. 1 (November 20, 2019): 35. http://dx.doi.org/10.3390/proceedings2019031035.
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Pedestrian detection is one of the key problems in the emerging self-driving car industry. In addition, the Histogram of Gradients (HOG) algorithm proved to provide good accuracy for pedestrian detection. Many research works focused on accelerating HOG algorithm on FPGA (Field-Programmable Gate Array) due to its low-power and high-throughput characteristics. In this paper, we present an energy-efficient HOG-based implementation for pedestrian detection system on a low-cost FPGA system-on-chip platform. The hardware accelerator implements the HOG computation and the Support Vector Machine classifier, the rest of the algorithm is mapped to software in the embedded processor. The hardware runs at 50 Mhz (lower frequency than previous works), thus achieving the best pixels processed per clock and the lower power design.
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Zakalek, Paul, Paul-Emmanuel Doege, Johannes Baggemann, Eric Mauerhofer, and Thomas Brückel. "Energy and target material dependence of the neutron yield induced by proton and deuteron bombardment." EPJ Web of Conferences 231 (2020): 03006. http://dx.doi.org/10.1051/epjconf/202023103006.
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The neutron yield for compact accelerator driven neutron sources depends on the target material, the ion type and its energy. When such sources are operated with low energy proton beams below 30 MeV, typical target materials are lithium and beryllium. New developments indicate that higher energies or a deuteron beam might be useful to increase the neutron yield at constant accelerator power. Here we present the total neutron yield analytically calculated for protons and deuterons at energies up to 100 MeV for various target materials. The total neutron yield depends on the involved cross sections and the stopping power of the target material. This study shows that for energies lower than 30 MeV light target materials with a deuteron beam are preferable whereas for energies above 30 MeV heavy target materials show a high neutron yield with little difference for a proton or deuteron beam.
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WEBB, PAUL W. "Is the High Cost of Body/Caudal Fin Undulatory Swimming due to increased Friction Drag or Inertial Recoil?" Journal of Experimental Biology 162, no. 1 (January 1, 1992): 157–66. http://dx.doi.org/10.1242/jeb.162.1.157.
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Deep-bodied fish, such as the bluegill sunfish {Lepomis macrochirus), are considered to have relatively larger wetted surface areas for their size than fusiform fish. On the basis of the boundary layer thinning hypothesis attributing high power requirements of undulatory swimming to enhanced friction drag, power (=drag) coefficients should be higher for such fish. Areas are typically normalized with total length, L, as L2 for comparison among species. Bluegill had a wetted surface area of 0.65 L2, compared with areas of about 0.41 L2 for trout of similar mass. However, absolute areas and volume2/3 of bluegill and trout were similar. Power requirements and power coefficients calculated from kinematics during steady swimming were lower for bluegill sunfish than for cruisers, such as trout, and power coefficients were also lower than those of accelerators, such as tiger musky. Large body depth also damps inertial recoil arising from the side force generated largely by the tail. Inertial energy losses appear to be more important contributors than friction to mechanical power requirements.
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Saquilayan, G. Q., M. Kisaki, A. Kojima, Y. Shimabukuro, M. Murayama, J. Hiratsuka, M. Ichikawa, K. Watanabe, H. Tobari, and M. Kashiwagi. "High Power Density Beam Measurement of a Single Beamlet Multi-Grid Prototype H- Negative Ion Accelerator." Journal of Physics: Conference Series 2244, no. 1 (April 1, 2022): 012091. http://dx.doi.org/10.1088/1742-6596/2244/1/012091.
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Abstract Beam optics of the ITER prototype accelerator with 88 mm acceleration gap length has been examined through H- beam acceleration tests at the ITER target beam perveance. The beam optics has been examined for beam energies up to 790 keV under the ITER target perveance. The total grid heat load was successfully reduced to 10 %, which was lower than the allowable value of 15 %. The beam emittance of the ITER perveance has been measured for the first time by using newly developed emittance measurement system consisting of carbon-fiber-composite (CFC) plate with pin-holes. The emittance of 790 keV H- beam shows the divergence angle of the beam core is satisfied with the ITER requirement of <7 mrad. Measurement at the beam periphery was made possible by modifying the pin-hole size of pepper-pot apertures, and the observed divergent components were 20 mrad. The ratio of the diverged beam became lower with the increase of the beam energy. This result contributes the design of the ITER accelerator and the beam line components.
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Yuan, Conggui, Xin Zheng, Bo Rao, and Shuting Cai. "An Easy-to-Integrate IP Design of AHB Slave Bus Interface for the Security Chip of IoT." Mathematical Problems in Engineering 2021 (November 1, 2021): 1–11. http://dx.doi.org/10.1155/2021/5154769.
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Information security is fundamental to the Internet of things (IoT) devices, in which security chip is an important means. This paper proposes an Advanced High-performance Bus Slave Control IP (AHB-SIP), which applies to cryptographic accelerators in IoT security chips. Composed by four types of function registers and AHB Interface Control Logic (AICL), AHB-SIP has a simple and easy-to-use structure. The System on Chip (SoC) design can be realized by quickly converting the nonstandard interface of the security module to the AHB slave interface. AHB-SIP is applied to the security accelerators of SM2, SM3, and SM4 and random number generator (RNG). Combined with a low-power embedded CPU, TIMER, UART, SPI, IIC, and other communication interfaces, a configurable SoC can be integrated. Moreover, SMIC 110 nm technology is employed to tape out the SoC on a silicon chip. The area of AHB-SIP is 0.072 mm2, only occupying 6‰ of the chip (3.45 ∗ 3.45 mm2), and the power consumption of encryption modules combined with AHB-SIP is lower than that combined with AXI interface, which is decreased up to 61.0% and is ideal for the application of IoT.
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Lysenko, Elena, Vitaly Vlasov, Evgeniy Nikolaev, Anatoliy Surzhikov, and Sergei Ghyngazov. "Technological Aspects of Lithium-Titanium Ferrite Synthesis by Electron-Beam Heating." Materials 16, no. 2 (January 8, 2023): 604. http://dx.doi.org/10.3390/ma16020604.
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Solid-phase synthesis of lithium-titanium ferrite by electron-beam heating of a Fe2O3–Li2CO3–TiO2 initial reagents mixture with different history (powder, compact, mechanically activated mixture) was studied using X-ray diffraction, thermomagnetometric and specific saturation magnetization analyses. Ferrite was synthesized using an ILU-6 pulsed electron accelerator; it generated electrons with electron energy of 2.4 MeV to heat samples to temperatures of 600 and 750 °C. The isothermal holding time upon reaching the synthesis temperature was 0–120 min. The efficiency of ferrite synthesis by electron-beam heating was evaluated via comparison of the characteristics of the obtained samples with those synthesized by conventional ceramic technology under similar temperature-time conditions. It was found that the rate of ferrite formation depends on the heating method, temperature, synthesis time, density, and activity of the initial mixture. It was shown that sample compaction provides the preferential formation of unsubstituted lithium ferrite of Li0.5Fe2.5O4 composition with a Curie temperature of at ca. 630 °С in both synthesis methods. High-energy electron-beam heating of the mechanically activated mixture significantly accelerates synthesis of Li0.6Fe2.2Ti0.2O4 substituted ferrite, for which the Curie temperature and specific saturation magnetization were recorded as 534 °С and 50 emu/g, respectively. Therefore, LiTi ferrites can be obtained at a lower temperature (750 °C) and with a shorter synthesis time (120 min) compared to traditional ceramic technology.
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Baklanov, Alexander Alexeevich, and Stanislav Gennadyevich Istomin. "Efficiency of using electric power for traction of ED4M electric multiple units." Transport of the Urals, no. 1 (2020): 85–89. http://dx.doi.org/10.20291/1815-9400-2020-1-85-89.
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The paper presents results of 6-car and 8-car ED4M electric multiple unit rides and assessments of various factors influence on power consumption. In particular, the paper considers modes of starting and braking on example of speed-time curves and traction motor current-time curves at different starting accelerations. A detailed analysis showed at unaltered running time due to higher starting acceleration and lower starting braking speed the power consumption decreases and at lower starting acceleration and higher starting braking speed it increases. Besides, the paper considers an influence of such factors as density of population, train length, weather conditions and divergence of characteristics of motor-wheel units of motor cars.
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Mukhanbet, A. A., E. S. Nurakhov, and B. S. Daribayev. "Implementation of a number recognition algorithm built using a neural network on the BASYS3 FPGA panel." Bulletin of the National Engineering Academy of the Republic of Kazakhstan 82, no. 4 (December 15, 2021): 86–96. http://dx.doi.org/10.47533/2020.1606-146x.119.
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In recent years, some field programmable valve arrays (FPGAs) based on CNN release phase accelerators have been introduced. FPGA is widely used in portable devices. They can be programmed to achieve higher concurrency and provide better performance. The power consumption of the FPGA is lower than that of GPUs with the same workload. These reasons make the FPGA suitable for implementing the CNN release phase. They can provide relative output performance for GPUs and achieve low power consumption, which is very important for portable devices. To effectively implement the CNN output phase on the FPGA, the design should have high parallelism, and the hardware resources used should be minimized to reduce the area and power consumption. In the process of working with the help of a neural network, an algorithm for recognizing handwritten numbers is implemented. A special architecture is being created to implement a neural network at the appatent level. The performance during operation and power consumption is comparable to the performance of the processor and the GPU.
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Matthews, James H., and Andrew M. Taylor. "Particle acceleration in radio galaxies with flickering jets: GeV electrons to ultrahigh energy cosmic rays." Monthly Notices of the Royal Astronomical Society 503, no. 4 (March 17, 2021): 5948–64. http://dx.doi.org/10.1093/mnras/stab758.
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ABSTRACT Variability is a general property of accretion discs and their associated jets. We introduce a semi-analytical model for particle acceleration and radio jet/lobe evolution and explore the effect of Myr time-scale jet variability on the particles accelerated by an active galactic nucleus (AGN) jet. Our work is motivated by the need for local powerful ultrahigh energy cosmic ray (UHECR) sources and evidence for variability in AGN and radio galaxies. Our main results are (i) UHECR and non-thermal radiative luminosities track the jet power but with a response set by the escape and cooling times, respectively; (ii) jet variability produces structure in the electron, synchrotron, and UHECR spectra that deviates from that produced for a constant jet power – in particular, spectral hardening features may be signatures of variability; (iii) the cutoff in the integrated cosmic ray (CR) spectrum is stretched out due to the variation in jet power (and, consequently, maximum CR energy). The resulting spectrum is the convolution of the jet power distribution and the source term. We derive an approximate form for a lognormal distribution of powers; and (iv) we introduce the idea of ${\sim}10\,$ GeV ‘proxy electrons’ that are cooling at the same rate that UHECRs of rigidity $10\,$ EV are escaping from the source, and determine the corresponding photon frequencies that probe escaping UHECRs. Our results demonstrate the link between the history of an astrophysical particle accelerator and its particle contents, non-thermal emission, and UHECR spectrum, with consequences for observations of radio galaxies and UHECR source models.
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Sadeghi, H., R. Amrollahi, S. Fazelpour, and M. Omrani. "Simulation of dense plasma focus devices to produce N-13 efficiently." Laser and Particle Beams 37, no. 2 (May 14, 2019): 209–16. http://dx.doi.org/10.1017/s0263034619000363.
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AbstractA novel idea is presented in this paper to simulation, design, and feasibility of making a machine in order to produce nitrogen 13 (N-13) at a much lower cost than conventional medical applications. In a plasma focus device, only 0.02% of the generated ions have more than 1 MeV energy. In this paper, using a new idea we have tried to find a solution to increase the energy of deuterium ions to produce N-13. To achieve this, a series of magnetic lenses has been used to focus and guide the ions. To increase the ion energy, a small linear accelerator has been designed using a TM010 waveguide. The accelerator waveguide is also designed and optimized to have the highest impedance matching and maximum power transmission. Eventually, low-energy ions that are transmitted by magnetic lenses accelerate in the waveguide electric field and their energy increases significantly. The collision of these energetic ions with graphite target produce N-13.
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Huang, Hongzhi, Yakun Wu, Mengqi Yu, Xuesong Shi, Fei Qiao, Li Luo, Qi Wei, and Xinjun Liu. "EDSSA: An Encoder-Decoder Semantic Segmentation Networks Accelerator on OpenCL-Based FPGA Platform." Sensors 20, no. 14 (July 17, 2020): 3969. http://dx.doi.org/10.3390/s20143969.
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Visual semantic segmentation, which is represented by the semantic segmentation network, has been widely used in many fields, such as intelligent robots, security, and autonomous driving. However, these Convolutional Neural Network (CNN)-based networks have high requirements for computing resources and programmability for hardware platforms. For embedded platforms and terminal devices in particular, Graphics Processing Unit (GPU)-based computing platforms cannot meet these requirements in terms of size and power consumption. In contrast, the Field Programmable Gate Array (FPGA)-based hardware system not only has flexible programmability and high embeddability, but can also meet lower power consumption requirements, which make it an appropriate solution for semantic segmentation on terminal devices. In this paper, we demonstrate EDSSA—an Encoder-Decoder semantic segmentation networks accelerator architecture which can be implemented with flexible parameter configurations and hardware resources on the FPGA platforms that support Open Computing Language (OpenCL) development. We introduce the related technologies, architecture design, algorithm optimization, and hardware implementation of the Encoder-Decoder semantic segmentation network SegNet as an example, and undertake a performance evaluation. Using an Intel Arria-10 GX1150 platform for evaluation, our work achieves a throughput higher than 432.8 GOP/s with power consumption of about 20 W, which is a 1.2× times improvement the energy-efficiency ratio compared to a high-performance GPU.
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Waisman, Eduardo M., M. E. Cuneo, R. W. Lemke, D. B. Sinars, and W. A. Stygar. "Lower bounds for the kinetic energy and resistance of wire array Z pinches on the Z pulsed-power accelerator." Physics of Plasmas 15, no. 4 (2008): 042702. http://dx.doi.org/10.1063/1.2898724.
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Kedzierski, Jakub, and Eric Holihan. "Linear and rotational microhydraulic actuators driven by electrowetting." Science Robotics 3, no. 22 (September 19, 2018): eaat5643. http://dx.doi.org/10.1126/scirobotics.aat5643.
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Microhydraulic actuators offer a new way to convert electrical power to mechanical power on a microscale with an unmatched combination of power density and efficiency. Actuators work by combining surface tension force contributions from a large number of droplets distorted by electrowetting electrodes. This paper reports on the behavior of microgram-scale linear and rotational microhydraulic actuators with output force/weight ratios of 5500, cycle frequencies of 4 kilohertz, <1-micrometer movement precision, and accelerations of 3 kilometers/second2. The power density and the efficiency of the actuators were characterized by simultaneously measuring the mechanical work performed and the electrical power applied. Maximum output power density was 0.93 kilowatt/kilogram, comparable with the best electric motors. At maximum power, the actuator was 60% efficient, but efficiencies were as high as 83% at lower power. Rotational actuators demonstrated a torque density of 79 newton meters/kilogram, substantially more than electric motors of comparable diameter. Scaling the droplet pitch from 100 to 48 micrometers increased power density from 0.27 to 0.93 kilowatt/kilogram, validating the quadratic scaling of actuator power.
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Vázquez-Guerrero, Jairo, Luis Suarez-Arrones, David Casamichana Gómez, and Gil Rodas. "Comparing external total load, acceleration and deceleration outputs in elite basketball players across positions during match play." Kinesiology 50, no. 2 (2018): 228–34. http://dx.doi.org/10.26582/k.50.2.11.
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The aim of this study was to compare external load, calculated by an accelerometer training load model, the number and intensity of accelerations and decelerations, and the acceleration:deceleration ratio between playing positions during basketball matches. Twelve elite male basketball players (mean±SD, age: 25.5±5.2 years; (range: 19-36 years); body height 201.4±8.6 cm; body mass: 98.4±12.6 kg) were monitored during two official matches. An accelerometer training load model and the number of accelerations and decelerations were used to assess physical demands imposed on basketball players. Magnitude-based inferences and effect sizes (ES) were used to assess possible differences between positions: point guards (PG), shooting guards (SG), small forwards (SF), power forwards (PF) and centers (C). Elite basketball players in all positions presented higher maximal decelerations than accelerations (ES=2.70 to 6.87) whereas the number of moderate accelerations were higher than the number of moderate decelerations (ES=0.54 to 3.12). Furthermore, the acceleration:deceleration ratio (>3 m∙s-2) was significantly lower in players on the perimeter (PG and SG) than in PF and C (ES=1.03 to 2.21). Finally, PF had the lowest total external load (ES=0.67 to 1.18). These data allow us to enlarge knowledge of the external demands in basketball matches and this information could be used in the planning of training programs
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Kavanagh, Justin J., Steven Morrison, and Rod S. Barrett. "Lumbar and cervical erector spinae fatigue elicit compensatory postural responses to assist in maintaining head stability during walking." Journal of Applied Physiology 101, no. 4 (October 2006): 1118–26. http://dx.doi.org/10.1152/japplphysiol.00165.2006.
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The purpose of this study was to examine how inducing fatigue of the 1) lumbar erector spinae and 2) cervical erector spinae (CES) muscles affected the ability to maintain head stability during walking. Triaxial accelerometers were attached to the head, upper trunk, and lower trunk to measure accelerations in the vertical, anterior-posterior, and mediolateral directions during walking. Using three accelerometers enabled two adjacent upper body segments to be defined: the neck segment and trunk segment. A transfer function was applied to root mean square acceleration, peak power, and harmonic data derived from spectral analysis of accelerations to quantify segmental gain. The structure of upper body accelerations were examined using measures of signal regularity and smoothness. The main findings were that head stability was only affected in the anterior-posterior direction, as accelerations of the head were less regular following CES fatigue. Furthermore, following CES fatigue, the central nervous system altered the attenuation properties of the trunk segment in the anterior-posterior direction, presumably to enhance head stability. Following lumbar erector spinae fatigue, the trunk segment had greater gain and increased regularity and smoothness of accelerations in the mediolateral direction. Overall, the results of this study suggest that erector spinae fatigue differentially altered segmental attenuation during walking, according to the level of the upper body that was fatigued and the direction that oscillations were attenuated. A compensatory postural response was not only elicited in the sagittal plane, where greater segmental attenuation occurred, but also in the frontal plane, where greater segmental gain occurred.
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Arzeo, M., F. Avino, S. Pfeiffer, G. Rosaz, M. Taborelli, L. Vega-Cid, and W. Venturini-Delsolaro. "Enhanced radio-frequency performance of niobium films on copper substrates deposited by high power impulse magnetron sputtering." Superconductor Science and Technology 35, no. 5 (April 8, 2022): 054008. http://dx.doi.org/10.1088/1361-6668/ac5646.
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Abstract We present a study of radio frequency properties of niobium films deposited on copper by two different approaches based on High Power Impulse Magnetron Sputtering, namely with a DC voltage biased substrate and with bipolar target voltage. Such approaches enable the synthesis of dense superconducting (SC) layers. The SC radio frequency losses of these films are characterized as a function of the applied RF magnetic field using a dedicated calorimetric method. We report on a significant reduction of the Q-slope phenomenon and the residual surface resistance in the characterized films, achieving similar values as those obtained on bulk niobium surfaces qualified with the same technique. Our results pave the way towards the realization of Nb/Cu coated accelerating cavities featuring a surface resistance 2–3 times lower than the state-of-the-art values at working frequencies of 400 and 800 MHz, making this technology even more appealing for future particle accelerators and colliders.
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Li, Shuai, Kuangyuan Sun, Yukui Luo, Nandakishor Yadav, and Ken Choi. "Novel CNN-Based AP2D-Net Accelerator: An Area and Power Efficient Solution for Real-Time Applications on Mobile FPGA." Electronics 9, no. 5 (May 18, 2020): 832. http://dx.doi.org/10.3390/electronics9050832.
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Standard convolutional neural networks (CNNs) have large amounts of data redundancy, and the same accuracy can be obtained even in lower bit weights instead of floating-point representation. Most CNNs have to be developed and executed on high-end GPU-based workstations, for which it is hard to transplant the existing implementations onto portable edge FPGAs because of the limitation of on-chip block memory storage size and battery capacity. In this paper, we present adaptive pointwise convolution and 2D convolution joint network (AP2D-Net), an ultra-low power and relatively high throughput system combined with dynamic precision weights and activation. Our system has high performance, and we make a trade-off between accuracy and power efficiency by adopting unmanned aerial vehicle (UAV) object detection scenarios. We evaluate our system on the Zynq UltraScale+ MPSoC Ultra96 mobile FPGA platform. The target board can get the real-time speed of 30 fps under 5.6 W, and the FPGA on-chip power is only 0.6 W. The power efficiency of our system is 2.8× better than the best system design on a Jetson TX2 GPU and 1.9× better than the design on a PYNQ-Z1 SoC FPGA.
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Hua, Quan, Vladimir A. Levchenko, and Matthew A. Kosnik. "Direct AMS 14C Analysis of Carbonate." Radiocarbon 61, no. 5 (April 15, 2019): 1431–40. http://dx.doi.org/10.1017/rdc.2019.24.
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ABSTRACTWe have investigated the possibility of direct accelerator mass spectrometry radiocarbon (AMS 14C) measurement of carbonate samples at ANSTO using the STAR 2 MV tandem accelerator. Each carbonate sample was powdered, mixed with metal powder and pressed into an aluminum cathode for direct carbonate measurement by AMS 14C. Of the three high-purity metal powders (Fe, Nb, and Ag) used in our investigation, Nb was found to be the best metal, which delivered higher carbon beam currents and lower background. Beam currents for targets containing the optimal carbonate mass of 1.5–2.0 mg were ∼8% of those obtained from graphite targets of standard size (>0.5 mg C). Typical measured blank for Carrara marble (IAEA-C1) of ∼40 ka was obtained. Background-corrected 14C values of carbonate targets agreed well with their associated values obtained from high-precision analysis of graphite targets within 2σ uncertainties. Typical precision of this rapid AMS analysis was ∼1% for samples <8 ka. Despite lower precision for carbonate target ages (compared to standard graphite target ages), these ages are useful for palaeobiological applications where a large number of dates are required, such as time-averaging studies.
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Eliseev, A. A., V. R. Utyaganova, A. V. Vorontsov, V. V. Ivanov, V. E. Rubtsov, and E. A. Kolubaev. "Comparative analysis of structure and mechanical properties of parts produced by electron-beam additive manufacturing and cold metal transfer." Izvestiya Vuzov. Tsvetnaya Metallurgiya (Universities' Proceedings Non-Ferrous Metallurgy), no. 4 (August 14, 2020): 65–73. http://dx.doi.org/10.17073/0021-3438-2020-4-65-73.
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Currently, the most prospective industry development areas are prototyping and additive manufacturing. In contrast to more precise powder technologies, faster wire technologies providing non-porous products are of great interest. This paper contains a comparative analysis of the effect of two wire technologies – electron-beam additive manufacturing and cold metal transfer – on the structure and mechanical properties of Aluminum Alloy 5056. Electron beam power is close to arc power at optimal printing parameters, but cold metal transfer is cheaper due to the impulse nature of the arc. In addition, the arc method is implemented in an argon atmosphere, and this accelerates the applied layer cooling. In general, the grain structure of the material is refined due to the lower heat transfer and accelerated cooling. This results in increased strength and microhardness. The constant heat removal from the substrate and the increase in the product weight change thermal conditions of the following layer. This is controlled by beam/arc powder reduction, but each layer has its own thermal history affecting the structure and properties. In particular, the more heat is transferred to the layer from the previous layers, the less strong it is. When a certain height (about 30 mm) is passed, cooling is intensified by the large mass of the product and the strength is increased again. This is most characteristic for cold metal transfer. However, these fluctuations are rather small. Mechanical properties along the growth direction are highly stable in both technologies. Cold metal transfer also shows less alloying magnesium burn-off. In general, currently the cold metal transfer technology is more cost effective and provides better quality products.
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Li, Yan, Lei Ni, Jing Ye, Zhixing Mei, and Jun Lin. "Particle Accelerations in a 2.5-dimensional Reconnecting Current Sheet in Turbulence." Astrophysical Journal 938, no. 1 (October 1, 2022): 24. http://dx.doi.org/10.3847/1538-4357/ac8b6d.
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Abstract Electric field induced in magnetic reconnection is an efficient mechanism for generating energetic particles, but the detailed role it plays is still an open question in solar flares. In this work, accelerations of particles in an evolving reconnecting current sheet are investigated via the test-particle approach, and the electromagnetic field is taken in a self-consistent fashion from a 2.5D numerical experiment for the magnetic reconnection process in the corona. The plasma instabilities like the tearing mode in the current sheet produce magnetic islands in the sheet, and island merging occurs as well. For the motion of the magnetic island, it yields the occurrence of the opposite electric field at both endpoints of the island; hence, tracking the accelerated particles around magnetic islands suggests that the parallel acceleration does not apparently impact the energy gain of particles, but the perpendicular acceleration does. Furthermore, our results indicate that the impact of the guide field on the trajectory of accelerated particles in a more realistic electromagnetic configuration works only on those particles that are energetic enough. The energy spectra of both species show a single power-law shape. The higher-energy component of the power-law spectrum results from the particles that are trapped in the current sheet, while the escaped and partly trapped particles contribute to the lower-energy component of the spectrum. The evolution of the spectrum shows a soft-hard-soft pattern that has been observed in flares.
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Filippas, Dionysios, Chrysostomos Nicopoulos, and Giorgos Dimitrakopoulos. "Templatized Fused Vector Floating-Point Dot Product for High-Level Synthesis." Journal of Low Power Electronics and Applications 12, no. 4 (October 17, 2022): 56. http://dx.doi.org/10.3390/jlpea12040056.
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Machine-learning accelerators rely on floating-point matrix and vector multiplication kernels. To reduce their cost, customized many-term fused architectures are preferred, which improve the latency, power, and area of the designs. In this work, we design a parameterized fused many-term floating-point dot product architecture that is ready for high-level synthesis. In this way, we can exploit the efficiency offered by a well-structured fused dot-product architecture and the freedom offered by high-level synthesis in tuning the design’s pipeline to the selected floating-point format and architectural constraints. When compared with optimized dot-product units implemented directly in RTL, the proposed design offers lower-latency implementations under the same clock frequency with marginal area savings. This result holds for a variety of floating-point formats, including standard and reduced-precision representations.
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Cho, Li, Cheng-Yu Chen, and Chau-Yun Hsu. "Improved ISR for IEEE 802.11ah Nonlinearity Compensation via Adjustable Constellation Borders." Electronics 10, no. 13 (June 30, 2021): 1573. http://dx.doi.org/10.3390/electronics10131573.
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Iterative subcarrier regularization (ISR) has been recently proposed as a receiver-side remedy for orthogonal frequency division multiplexing (OFDM) nonlinearity. It allows the power amplifier of OFDM transmitters to operate at a lower input back-off for more efficient uplinks. However, the compensation ability cannot align with increasing channel quality, because the standard quadrature amplitude modulation (QAM) used in ISR may eliminate compensation due to erroneous decisions. To solve this issue, an improved version of ISR was proposed to flexibly adjust the constellation borders of QAM and numerically optimize it based on IEEE 802.11ah (hereinafter referred to as 802.11ah) specifications. Simulations show that the proposed scheme not only improves the converged bit error rate of ISR but also accelerates its own convergence, especially in a high channel quality, thereby achieving better power efficiency for Internet of Things clients without additional computational complexity.
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Anwar Syahmi, Mas Fawzi, Shahrul Azmir Osman, and Harrison Lau. "Engine Performance and Exhaust Emission Effect of Increasing Euro5 Diesel Fuel Blended with 7% to 30% Palm Biodiesel." Journal of Advanced Research in Applied Sciences and Engineering Technology 28, no. 2 (October 17, 2022): 34–40. http://dx.doi.org/10.37934/araset.28.2.3440.
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Biodiesel blend fuels have gained popularity over the year due to their ability to be used in conventional diesel engines without any modifications and have proven to be a cleaner fuel. The Malaysian National Automotive Policy (NAP) 2020 projects the usage of biodiesel blend B30 (30%) to be implemented by the year 2025 or earlier. Most manufacturers approve its usage but do not suggest using a higher blend than 20%. This paper focuses on the difference in engine performance and exhaust emissions between 7 % and 30% Euro 5 diesel-biodiesel blend. The fuels used are Euro 5 diesel fuel blend with 7% (B7) and 30% (B30) palm biodiesel. The fuel is tested on a Toyota Hilux model KUN 25 with a 2KD-FTV engine. Chassis dynamometer tests were conducted on a steady-state condition for speeds 30, 60, 90, and 110 km/h with accelerator pedal positions (APP) of 45% and 90% measuring its brake power, BSFC, and exhaust emissions of CO2, CO, and NOx. It was found that B30 produced slightly lower brake power than B7 and slightly higher BSFC than B7. Both CO2 and CO emissions for B30 are lower than B7, with a more significant difference at speed 30 km/h at all APP conditions. NOx emission for B30 is higher at speed 30 km/h but slightly lower at speed 60, 90, and 110 km/h than B7. Therefore, increasing Euro 5 biodiesel blend from 7% to 30% slightly lowers brake power, increases BSFC, lowers CO2 and CO emissions, and increases NOx emissions.
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Xiang, Maoyang, and Tee Hui Teo. "Implementation of Binarized Neural Networks in All-Programmable System-on-Chip Platforms." Electronics 11, no. 4 (February 21, 2022): 663. http://dx.doi.org/10.3390/electronics11040663.
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The Binarized Neural Network (BNN) is a Convolutional Neural Network (CNN) consisting of binary weights and activation rather than real-value weights. Smaller models are used, allowing for inference effectively on mobile or embedded devices with limited power and computing capabilities. Nevertheless, binarization results in lower-entropy feature maps and gradient vanishing, which leads to a loss in accuracy compared to real-value networks. Previous research has addressed these issues with various approaches. However, those approaches significantly increase the algorithm’s time and space complexity, which puts a heavy burden on those embedded devices. Therefore, a novel approach for BNN implementation on embedded systems with multi-scale BNN topology is proposed in this paper, from two optimization perspectives: hardware structure and BNN topology, that retains more low-level features throughout the feed-forward process with few operations. Experiments on the CIFAR-10 dataset indicate that the proposed method outperforms a number of current BNN designs in terms of efficiency and accuracy. Additionally, the proposed BNN was implemented on the All Programmable System on Chip (APSoC) with 4.4 W power consumption using the hardware accelerator.
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Deng, Yangbao, Bing Wen, Liezun Chen, Saiwen Zhang, Guangfu Zhang, Cuixiu Xiong, and Xiaoling Leng. "Propagation properties of cosh-Airy beams in an inhomogeneous medium with Gaussian PT-symmetric potentials." Open Physics 20, no. 1 (January 1, 2022): 1031–40. http://dx.doi.org/10.1515/phys-2022-0202.
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Abstract We numerically investigate and statistically analyze the impact of medium parameters (modulation depth P, modulation factor ω, and gain/loss strength W 0) and beam parameters (truncation coefficient a and distribution factor χ 0) on the propagation characteristics of a cosh-Airy beam in the Gaussian parity-time (PT)-symmetric potential. It is demonstrated that the main lobe of a cosh-Airy beam is captured as a soliton, which varies periodically during propagation. The residual beam self-accelerates along a parabolic trajectory due to the self-healing property. With increment in P, the period of a trapped soliton decreases almost monotonically, while the peak power of a trapped soliton increases monotonically. With the increase in ω or decrease in the absolute value of W 0, the period and peak power of a trapped soliton decrease rapidly and then almost remain unchanged. Moreover, it is indicated that the period of a trapped soliton remains basically unchanged no matter a and χ 0 increase or decrease. The peak power of a trapped soliton increases with increment of a, but the peak power of a trapped soliton stays relatively constant irrespective of variation in χ 0.
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Song, Chenning, Chao Wei, and Zhi Zhang. "Research on Seismic Response of Base-Isolated Nuclear Island Building considering FSI Effect of PCS Water Tank." Advances in Civil Engineering 2020 (August 27, 2020): 1–15. http://dx.doi.org/10.1155/2020/8878507.
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Base isolation can be used to reduce seismic response of structure and protect the structure from damage subjected to earthquake. To study the isolation effect of new PWR nuclear power plant with a base isolation system, considering FSI (fluid-structure interaction) effect by the simplified model, two 3D numerical models (one nonisolated model and one isolated model) were established. After natural frequency analysis, one artificial ground motion was chosen to analyze isolation effect qualitatively. Based on the results, the accelerations and relative displacements of nuclear island building under ten natural ground motions were statistically analyzed to evaluate the isolation effect quantitatively. The results show that the base isolation system can reduce the natural frequencies of nuclear island building. Horizontal accelerations can be reduced effectively, but the isolation effect is not obvious in vertical direction. The acceleration reduction ratio of the top is about 70%–90%, and the acceleration reduction ratio of the lower part is about 20%–60%. Horizontal displacement of the isolated model is far larger than that of the nonisolated model, and horizontal displacement will become larger considering FSI effect. These conclusions could provide some references for studies on the isolation system of nuclear island building.
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Benjamin, C., H. M. Churn, T. J. Rehaag, L. A. J. Soomary, C. P. Welsch, L. B. Jones, T. C. Q. Noakes, and G. R. Bell. "Enhanced performance of an Ag(100) photocathode by an ultra-thin MgO film." Journal of Applied Physics 132, no. 19 (November 21, 2022): 195303. http://dx.doi.org/10.1063/5.0124528.
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Metal photocathodes are widely utilized as electron sources for particle accelerators for their ease of use, high durability, and fast response time. However, the high work function (WF) and low quantum efficiency (QE) typically observed in metals necessitate the use of high power deep UV lasers. Metal oxide ultra-thin films on metals offer a route to photocathodes with a lower WF and improved QE while maintaining photocathode durability and response time. We show how the photocathode performance of an Ag(100) single crystal is enhanced by the addition of an ultra-thin MgO film. The film growth and WF reduction of 1 eV are characterized, and the QE and mean transverse energy (MTE) are measured as a function of illumination wavelength. An eightfold increase of QE is achieved at 266 nm without adding to MTE through additional surface roughness, and the resistance of the photocathode to O[Formula: see text] gas is greatly improved.
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Uchikawa, Takuya, Takeyuki Ueno, Takashi Hasegawa, Isao Maruyama, Shoichiro Kumamoto, and Yotaro Ando. "Parachlorella beyerinckii accelerates lead excretion in mice." Toxicology and Industrial Health 25, no. 8 (September 2009): 551–56. http://dx.doi.org/10.1177/0748233709346759.
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The effect of Parachlorella beyerinckii CK-5, previously identified as Chlorella vulgaris, on gastrointestinal absorption of lead was investigated in mice. Female ICR mice aged 7 weeks were orally administered lead acetate solution at doses of 20 mg and 40 mg of lead per mouse, with or without 100 mg of P. beyerinckii powder (BP). The mice were bred for 24 hours. The amount of lead excreted in feces within 24 hours, and the lead levels of the blood, liver and kidney were analyzed by atomic absorption spectrometry. The percentage of total fecal excretion in mice administered BP increased by 27.7% in 20 mg lead administered mice and 17.2% in 40 mg lead administered mice in comparison to control mice, respectively. On the other hand, the lead levels of the blood, liver and kidney of BPadministered mice at 24 hours after lead administration were 48-63% lower as compared with those of control mice. The lead adsorption ability of BP and the pepsin non-digestive residue of BP (dBP) were investigated in vitro. One hundred mg of BP and dBP could adsorb 10.6 mg and 6.0 mg of lead in a 20 mg per 10 mL of lead solution, respectively. The lead absorption abilities of BP and dBP were considered to contribute to the prevention of gastrointestinal absorption of lead and the promotion of the excretion of lead. These results suggested that BP treatment might be useful in animals and humans exposed to lead.
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Qin, Mingwei, Tong Liu, Baolin Hou, Yongxiang Gao, Yuancheng Yao, and Haifeng Sun. "A Low-Latency RDP-CORDIC Algorithm for Real-Time Signal Processing of Edge Computing Devices in Smart Grid Cyber-Physical Systems." Sensors 22, no. 19 (October 2, 2022): 7489. http://dx.doi.org/10.3390/s22197489.
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Smart grids are being expanded in scale with the increasing complexity of the equipment. Edge computing is gradually replacing conventional cloud computing due to its low latency, low power consumption, and high reliability. The CORDIC algorithm has the characteristics of high-speed real-time processing and is very suitable for hardware accelerators in edge computing devices. The iterative calculation method of the CORDIC algorithm yet leads to problems such as complex structure and high consumption of hardware resource. In this paper, we propose an RDP-CORDIC algorithm which pre-computes all micro-rotation directions and transforms the conventional single-stage iterative structure into a three-stage and multi-stage combined iterative structure, thereby enabling it to solve the problems of the conventional CORDIC algorithm with many iterations and high consumption. An accuracy compensation algorithm for the direction prediction constant is also proposed to solve the problem of high ROM consumption in the high precision implementation of the RDP-CORDIC algorithm. The experimental results showed that the RDP-CORDIC algorithm had faster computation speed and lower resource consumption with higher guaranteed accuracy than other CORDIC algorithms. Therefore, the RDP-CORDIC algorithm proposed in this paper may effectively increase computation performance while reducing the power and resource consumption of edge computing devices in smart grid systems.
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Zheng, Chuan, Pavel Fedorets, Ralf Engels, Chrysovalantis Kannis, Ilhan Engin, Sören Möller, Robert Swaczyna, et al. "Polarimetry for 3He Ion Beams from Laser–Plasma Interactions." Instruments 6, no. 4 (October 10, 2022): 61. http://dx.doi.org/10.3390/instruments6040061.
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We present a compact polarimeter for 3He ions with special emphasis on the analysis of short-pulsed beams accelerated during laser–plasma interactions. We discuss the specific boundary conditions for the polarimeter, such as the properties of laser-driven ion beams, the selection of the polarization-sensitive reaction in the polarimeter, the representation of the analyzing-power contour map, the choice of the detector material used for particle identification, as well as the production procedure of the required deuterated foil-targets. The assembled polarimeter has been tested using a tandem accelerator delivering unpolarized 3He ion beams, demonstrating good performance in the few-MeV range. The statistical accuracy and the deduced figure-of-merit of the polarimetry are discussed, including the count-rate requirement and the lower limit of accuracy for beam-polarization measurements at a laser-based ion source.
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Zanini, Luca, Esben Klinkby, Ferenc Mezei, and Alan Takibayev. "Low-dimensional moderators at ESS and compact neutron sources." EPJ Web of Conferences 231 (2020): 04006. http://dx.doi.org/10.1051/epjconf/202023104006.
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Low-dimensional moderators were designed for the European Spallation Source (ESS), and the same concepts can be applied to compact sources. At ESS, quasi two-dimensional (2D) high-brightness moderators will serve all the instruments of the initial suite. The design of the moderators is influenced by several factors, such as the layout of the facility, the requirements for beam extraction, and the number of instruments; these constraints led to the choice of the 2D “butterfly” moderator for ESS. In an accelerator-based compact source, such moderators can be designed in an even more efficient way than for high-power sources, taking advantage of the lower heat loads and of the more compact arrangement of the target-moderator system, which gives more freedom in the optimization of the geometrical setup. Some promising design options have been explored.
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Fuchs, Patrick, Live S. Luteberget, Philip X. Fuchs, and Herbert Wagner. "Comparative Analysis of the Indirect Calorimetry and the Metabolic Power Method to Calculate Energy Expenditure in Team Handball." Applied Sciences 12, no. 1 (December 24, 2021): 163. http://dx.doi.org/10.3390/app12010163.
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Monitoring physical activity, e.g., training load and energy expenditure (EE), is important to optimize the training process in various sports. Especially in team handball, where there is little information about EE in training and competition. The objective of the study was to compare EE in team handball derived from a respiratory gas exchange analysis (spiroergometry) and a local position measurement (LPM) system. Eleven participants completed a validated, team handball game-based performance test and wore a portable spiroergometry system (K5 Cosmed) and an LPM transponder (Catapult ClearSky T6). EE was determined via indirect calorimetry for spiroergometry data and via the metabolic power model for EE for LPM data. EE estimated via the metabolic power model was −66 to −63 ± 12% lower than via indirect calorimetry (p < 0.001, pη2 = 0.97). No correlation was found for the overall test (r = 0.32, p = 0.34), nor for every single heat (r ≤ 0.44, 0.18 ≤ p ≤ 0.99). Therefore, regression analyses predicting spiroergometry data based on LPM data were not feasible. In line with previous studies, the metabolic power model for EE in team handball (including short-distance movements, great accelerations, and non-locomotive actions) is not suitable.
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Gonzalez, John M., Ben Davis, Benjamin Morris, Edwin Brokesh, Daniel Flippo, Terry Houser, Francisco Najar-Villarreal, Kari Turner, and Jamison Williams. "4 Examining x, y, and z vibration patterns of commercial pig transport trailers from the farm to the abattoir." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 2. http://dx.doi.org/10.1093/jas/skaa278.003.
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Abstract The objective of this study was to measure and examine 3-axis acceleration data from 6 locations within commercial transport trailers shipping market pigs. Over winter months (December through February) of 2018 to 2019 and 2019 to 2020, 16 pot-belly and 14 straight-deck trailer loads of market pigs were measured from 2 producers located in Kansas and North Carolina, respectively. Six accelerometers were placed in protective cases and affixed to the underside of the floor in the approximate center of the front compartment, middle of the trailer, and back compartment of the top and bottom decks. Data were post-processed to calculate power spectral density (PSD) functions and corresponding root mean square (RMS) accelerations. The PSDs lend insight into the vibrational frequency content of the trailers, while the RMS values indicate the severity of the vibration over the duration of each trip. With the exception of the lower aft portion of the trailer where levels are significantly higher, RMS values were consistent across trips and largely similar between sensor location and axis. Accelerations ranged between 0.06 and 0.18 g and varied in time, indicating data were non-stationarity. The PSD results reveal a largely broadband frequency response of the loaded trailers between 0 and 50 Hz, especially for sensors on the lower deck. Preliminary analysis of the data indicates the severity of vibrations experienced by pigs during transport would be considered uncomfortable by humans.
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Xie, Tao, Zhengyu Li, Yongyun Zhang, Bin Yuan, and Xiao Liu. "Simulation Design of a Live Working Manipulator for Patrol Inspection in Power Grid." Journal of Robotics 2022 (September 14, 2022): 1–8. http://dx.doi.org/10.1155/2022/7318090.
Full textAbstract:
The distribution line network is the electric power infrastructure directly facing the users, with the characteristics of large coverage and complex network, and its operation safety is directly related to the stability and reliability of the power supply system, which is the key link to ensure the safety of power supply and the reliability of residential electricity consumption. In order to realize the autonomous obstacle avoidance and autonomous navigation of the live working manipulator for inspection and maintenance of the power grid equipment, a mobile manipulator intelligent control method combining SumTree-weighted sampling and deep deterministic policy gradient (DDPG) is proposed. Firstly, the traditional DDPG algorithm is improved to optimize the action value function of Q-learning to get a better control strategy, and the weighted sampling technique is used to add priority to each sample in the replay buffer, which improves the learning speed and accelerates the convergence speed. The corresponding environmental state space is designed, and simulation experiments are conducted to verify the proposed manipulator control method. Simulation results demonstrate that the proposed method performs better than traditional DDPG and DQN methods in obstacle avoidance and navigation tasks, with faster convergence, better path planning ability, and lower offset cost, which can provide theoretical and technical references for realizing fully autonomous power grid inspection operations.
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Yanci, Javier, Daniel Castillo, Aitor Iturricastillo, Tomás Urbán, and Raúl Reina. "External Match Loads of Footballers With Cerebral Palsy: A Comparison Among Sport Classes." International Journal of Sports Physiology and Performance 13, no. 5 (May 1, 2018): 590–96. http://dx.doi.org/10.1123/ijspp.2017-0042.
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Purpose: To determine and compare the external match load, according to sport class (FT), of footballers with cerebral palsy (CP) during the International Federation of CP Football World Championships Qualification Tournament. Methods: Forty-two international male footballers with CP participated in the data collection. The footballers with CP were classified according to their FT into 3 groups (ie, FT5/6, FT7, and FT8). External match load (ie, total distance covered, distance covered at different speeds, accelerations, decelerations, player load, peak metabolic power, and changes of directions) was collected for both halves during official matches with global positioning system devices. Results: Players with lower impairment (FT8) covered more distance (effect size = 0.30–0.60) at high-intensity running (13.0–18.0 km·h−1) and sprinting (>18.0 km·h−1) and performed more (effect size = 0.29–1.08) accelerations, decelerations, and changes of direction at high intensity in matches than did other players (ie, FT5/6 and FT7 groups). Conclusion: Because high-intensity actions are relevant to football performance and there are differences caused by players’ impairments, the International Federation of CP Football classification protocols should include high-intensity actions during the technical assessment as part of the procedures for determining the sport class of football players with CP.
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Jansson, Peter. "Water pressure and basal sliding on Storglaciären, northern Sweden." Journal of Glaciology 41, no. 138 (1995): 232–40. http://dx.doi.org/10.1017/s0022143000016130.
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AbstractThe subglacial hydrology of the ablation area of Storglaciären, a small valley glacier in northern Sweden, is dramatically affected by a subglacial ridge, or riegel. Water pressures above this riegel are relatively constant, while down-glacier from it they vary significantly. The lower part of the glacier accelerates in response to peaks in basal water pressure. The upper part may be weakly coupled to the lower part during these peaks.A power-law fit of observed basal water pressures and measured surface velocities yieldswhereusis the surface velocity andPEis the effective water pressure (ice overburden pressure minus subglacial water pressure). Data from Findelengletscher, reported by Iken and Bindschadler (1986), yield an identical exponent and a coefficient one order of magnitude larger. The similar exponent implies that the process producing the velocity variations on both glaciers is similar. The variations in velocity are inferred to be due to hydraulic jacking on both glaciers.
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Li, Qiang, Hongfa Yu, Haiyan Ma, Shudong Chen, and Shuguang Liu. "Test on Durability of Shield Tunnel Concrete Segment under Coupling Multi-Factors." Open Civil Engineering Journal 8, no. 1 (December 31, 2014): 451–57. http://dx.doi.org/10.2174/1874149501408010451.
Full textAbstract:
To study the durability of shield tunnel concrete segment under coupling multi-factors, the durability and degradation law of reinforced concrete segments under the joint action of carbonation, sulfate, chloride salt and stray current was studied by accelerated environmental and direct current (DC) power simulation test. The results show that the presence of the stray current not only accelerates the migration of chloride ions to the concrete, but also makes chlorine ion gradually converge to the steel surface. The steel corrosion near the corrosion solution on the up surface of segment is more serious than the steel corrosion near the carbon dioxide on the lower surface. The interaction of chlorine ions and stray current primarily controls the durability of the segment.
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Peper, Marius, and Boudewijn F. Roukema. "The role of the elaphrocentre in void galaxy formation." Monthly Notices of the Royal Astronomical Society 505, no. 1 (May 12, 2021): 1223–38. http://dx.doi.org/10.1093/mnras/stab1342.
Full textAbstract:
ABSTRACT Voids may affect galaxy formation via weakening mass infall or increasing disk sizes, which could potentially play a role in the formation of giant low surface brightness galaxies (LSBGs). If a dark matter halo forms at the potential hill corresponding to a void of the cosmic web, which we denote the ‘elaphrocentre’ in contrast to a barycentre, then the elaphrocentre should weaken the infall rate to the halo when compared to infall rates towards barycentres. We investigate this hypothesis numerically. We present a complete software pipeline to simulate galaxy formation, starting from a power spectrum of initial perturbations and an N-body simulation through to merger-history-tree based mass infall histories. The pipeline is built from well-established, free-licensed cosmological software packages, and aims at highly portable long-term reproducibility. We find that the elaphrocentric accelerations tending to oppose mass infall are modest. We do not find evidence of location in a void or elaphrocentric position weakening mass infall towards a galaxy. However, we find indirect evidence of voids influencing galaxy formation: while void galaxies are of lower mass compared to galaxies in high-density environments, their spin parameters are typically higher. For a fixed mass, the implied disc scale length would be greater. Tangential accelerations in voids are found to be high and might significantly contribute to the higher spin parameters. We find significantly later formation epochs for void galaxies; this should give lower matter densities and may imply lower surface densities of disc galaxies. Thus, void galaxies have higher spin parameters and later formation epochs; both are factors that may increase the probability of forming LSBGs in voids.