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Silver deposited TiO2 nanocomposites with tunable redox property were fabricated by laser ablation of silver and titanium targets in de-ionized water. This approach opens a route for one-step-synthesized redox system for potential applications in photocatalyst.
This paper describes the causes of cogging torque in Permanent Magnet synchronous Motor. Establishes a motor model by ANSOFT software, uses Finite Element Method to quantitative analysis and comparative peak cogging torque and torque with notches at different locations, and different number of auxiliary slot. The conclusion is that notch reasonable can reduce the cogging torque of permanent magnet...
When the airborne or missile borne radar works at the forward-looking imaging mode, the common techniques for improving azimuth resolution are invalid, because the difference between the Doppler frequencies of targets in different azimuths is very small. Meanwhile, other real beam sharpening methods only have very limited effect on azimuth resolution enhancement. For the problem of forward-looking...
By a simple step of laser ablation followed by stearic acid modification, the presence of synergistic dual micro/nanostructures and stearic acid endows hydrophobicity on copper surfaces. The wettability of copper surfaces fabricated with different laser processing parameters and experimental conditions was studied. The hydrophobicity of copper surfaces could extend their multiple applications.
As a new application platform of synthetic aperture radar (SAR), the near-space hypersonic vehicle has a more serious range migration problem than the traditional airborne platform due to its curved-flight motion characteristic, and its imaging results will be further affected under the condition of high resolution demand. Since the SAR slant range of hypersonic platform is relatively complicated,...
Researches on unmanned aerial vehicle (UAV) formation control are attracting more and more researchers' attention. Obstacle avoidance is a key problem of UAV formation. In this paper, an improved artificial potential field (APF) method is proposed for solving the problem of UAV formation control with obstacle avoidance in a complex environment. Point-mass models with kinematic constraints have been...
Location is an important context on which a broad range of context-aware applications can be built. Most previous approaches require the targets to carry electronic devices, while device-free passive localization is in need on many occasions. This paper proposes a device-free passive localization algorithm based on WiFi Channel State Information(CSI) and Support Vector Machines(SVM). In a physical...
Anomaly or outlier detection is a major challenge in big data analytics because anomaly patterns provide valuable insights for decision-making in a wide range of applications. Recently proposed anomaly detection methods based on the tree isolation mechanism are very fast due to their logarithmic time complexity, making them capable of handling big data sets efficiently. However, the underlying similarity...
In this paper, a novel framework that realizes identification of power MOSFETs for enhancing their security is proposed. Selecting mixture of measurable device parameters of MOSFETs as a feature vector, individual devices are robustly distinguished. In the experiments using a 11-parameter feature vector with machine learning techniques of random forest and support vector machine (SVM) as example classifiers,...
In large-scale LED lighting installation, it is sometimes unavoidable to use a long cable to connect light sources to LED drivers. Since LED drivers deliver pulse-width-modulated current, such long cable inductance effect prolongs the rise time of the current pulse and hence adversely affects the luminous output. In addition, the energy stored in cable will be discharging to the LEDs during the off...
WiFi fingerprinting has been a common solution to indoor localization, however its accuracy still cannot meet the requirements of high accurate indoor location based services. This paper proposes an optimized space partitioning technique followed by a two-layer WiFi fingerprinting based on SVM classification and regression. The proposed space partitioning technique first applies K-means clustering...
In this paper, a novel circuit simulation model for V-groove SiC power MOSFET with buried P-layers is proposed. By considering the structure of the MOSFET, bias dependence of on-resistance and the kink in the terminal capacitance are represented in the proposed model. Through experiments using a V-groove SiC MOSFET, it is demonstrated that the proposed model successfully reproduces both I-V and C-V...
Inner-Join is a fundamental and frequent operation in large-scale data analysis. MapReduce is the most widely available framework in large-scale data analysis. A variety of inner-join algorithms are put forward to run on the MapReduce environment. Usually, those algorithms are designed for specific scenarios, but inner-join could present very different performance when data volume, reference ratio,...
Lots of studies have shown that memory hardware error rates are orders of magnitude higher than previously reported. In order to fight with these memory hardware errors, many memory testing tools have been developed, especially software level online memory testers, which means these memory testers implemented in software can work with the OS (operating system) at the same time. However, validation...
It is sometimes unavoidable to use a long cable to connect the light source to the driver when they are placed far apart in large scale LED lighting installation. Since LED driver typically delivers pulse-width-modulated current pulses, the long cable inductance will delay the rate of rise of the current pulses and will also cause negative off-state voltage across the light source, reducing luminous...
Effect of nonlinear gain on the phase noise of Y-branch lasers is studied by numerical simulations, which are based on the developed transmission line model (TLM) and multimode rate equations superposed by Langevin noise sources and nonlinear gain terms. The nonlinear gain is found to have severe effects on the phase noise of the Y-branch lasers.
In this paper, a horizontally polarized antenna is proposed for the omnidirectional coverage in the 2.4-GHz WLAN band. The azimuthal omnidirectional pattern is provided by an open-ended cavity with a probe feed. The proposed structure exhibits good imitation of the ideal magnetic current with similar isotropic radiation pattern, even though with asymmetrical structure. A series of numerical simulations...
To keep competitive in the new dynamic market having more requirements in product various and delivery date, manufacturing companies need to make systems that not only response to market rapidly but also ensure delivery on time. Reconfigurable manufacturing system is a new paradigm to enhance the ability to response to the market rapidly and improve the performance rate. Capacity scalability is an...
Maintenance service delivery for large-scale equipment has been studied for decades and is becoming a crucial way for equipment manufacturers to obtain profit and competitiveness. To delivery maintenance service, equipment manufacturers need to optimal delivery plans with considering of various constraints (e.g. maintenance policy, service capacities, service costs) as well as maintenance type. This...
When a localized fault occurs in a bearing, the transient signals will appear in the acquired signal. The bearing fault mode can then be determined by analysis of the period of the transient signals. Many advanced signal processing algorithms have been proposed to realize period detection, but majority of them are complicated and require adequate computational resource. This paper proposed a new method...
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