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- 摘要
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- 实验方案
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[IEEE 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) - Atlanta, GA, USA (2017.10.21-2017.10.28)] 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) - Rapid Kalman-Filter stabilization technique for single- and multi-detector systems
摘要： Most spectroscopic applications, especially homeland security relevant equipment relies on well-calibrated spectral data. A Kalman filter is applied to the known problem of stabilization, which means online calibration of a scintillation detector to a predefined reference peak. The method uses stochastic assumptions on the measurement uncertainties and an iterative update with new measurements. Introducing prior knowledge about the stochastic and continuously resupplying new spectral data to the filter enhances the predicted gain correction value and allows a rapid determination of this value. In multi-detector setups, the spectral alignment of data from all detectors is mandatory for performing data fusion or any further evaluations. The described Kalman technique also allows to perform this rapid cross-detector synchronization online, leading to matched up spectra at acquisition time.
关键词： multi-detector systems,stabilization,Kalman filter,scintillation detector,spectral alignment
更新于2025-09-09 09:28:46
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15.4: Optical Rewritable Liquid Crystal Displays without Front Polarizer
摘要： A front polarizer-free optically rewritable (ORW) liquid crystal displays (LCDs) has been made via a hybrid alignment configuration with dye-doped LCs. The hybrid structure consists of one optically active planar and one optically passive homeotropic alignment layer. The rewritability of the device is achieved by photo- reorienting the azo dye molecules in the active planar alignment layer. The dye doped in LCs function as a polarizer by following the LCs alignment via a guest-host effect so that the front polarizer can be eliminated. This makes the device more compact and easier to operate for image erasing and rewriting. The image rewriting time only requires ~9.0s, which is determined by the exposure energy and LC parameters. The hybrid-mode dye-doped optically rewritable (DDORW) LCD devices could find applications in E-paper, transparent display and various photonics devices.
关键词： Photo-alignment,dichroic dye,hybrid mode.
更新于2025-09-09 09:28:46
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Influence of the alignment angle of molecules on the cutoff of the high-order harmonics
摘要： Using the Lewenstein model combined with the Ammosov–Delone–Krainov (ADK) ionization theories, the high-order harmonic generation (HHG) of the diatomic molecules O2 and N2 at the various alignment angles are investigated. We find that the cutoff of harmonic spectra from the aligned O2 and N2 are influenced by the alignment angles. The dependence of the cutoff energy on the alignment angle is attributed to the anisotropy in the molecular ionization, which is rooted in the nonuniform electron distributions of the highest occupied molecular orbital. If the polarization of the laser crosses the denser region of the electron cloud, the ionization rate is larger, and then the saturation laser intensity is smaller, therefore the harmonic spectra are cut off at the lower energy.
关键词： Ionization suppression,Alignment dependent harmonic spectra,Diatomic molecules
更新于2025-09-09 09:28:46
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The Measurement of Optical Interconnect Module Post-Soldering Alignment Offsets and The Study of Its Influence on Optical Coupling Efficiency
摘要： In the process of the optical interconnection module soldering assembly, the mismatch of the thermal expansion coefficient between the substrate and PCB would result in the production of alignment offset between light source devices and light-coupled devices, which would lead to light power loss. It is of great significance to study on the optical interconnect module alignment offset in the assembly process to improve optical interconnect module coupling efficiency. In the present study, an optical interconnection module key position post soldering shift offset measurement system was established, and an optical interconnection module experimental sample was prepared. The key position post soldering shift in the X and Y directions were measured. The 3D finite element analysis model of a typical optical interconnect module was established, and post soldering shift offsets were calculated after the finite elements analysis of the reflow soldering temperature load. The coupling efficiency simulation model of the optical interconnection module was established using the ZEMAX software, and the coupling efficiency was calculated according to the alignment offset measured in the experiment. The results revealed the following: The post soldering alignment offsets in the X and Y direction were 0.316 μm and 0.422 μm, respectively, and the synthetic alignment offset was 0.527 μm. The post soldering alignment offset calculated using the finite element simulation model was 0.436 μm, and its error was 17.2%, when compared with the measured value. The coupling efficiency of the optical interconnection module was 85.804% when the post soldering alignment offset was 0.527 μm.
关键词： Reflow soldering,Optical interconnect module,Multimode fiber,Alignment offset,Coupling efficiency
更新于2025-09-09 09:28:46
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Study on a Twice Transfer Alignment Based on Dual Model
摘要： This paper proposes a twice rapid transfer alignment algorithm based on dual models in order to solve the problems such as long convergence time, poor accuracy, and heavy computation burden resulting from the traditional nonlinear error models. The quaternion matching method based on quaternion error model along with the extended Kalman filter (EKF) is applied to deal with the large misalignment in the first phase. Then in the second transfer alignment phase, velocity plus attitude matching method as well as classical Kalman filter is adopted. The simulation and the results of vehicle tests demonstrate that this method combines the advantages of both nonlinear and linear error models with the guarantee of accuracy and fastness.
关键词： quaternion error model,extended Kalman filter,transfer alignment,dual models,velocity plus attitude matching
更新于2025-09-09 09:28:46
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[IEEE 2018 24th International Conference on Pattern Recognition (ICPR) - Beijing, China (2018.8.20-2018.8.24)] 2018 24th International Conference on Pattern Recognition (ICPR) - A New Method for Face Alignment under Extreme Poses and Occlusion
摘要： In real-world conditions, robust face alignment is challenging due to the large variability of occlusion and pose. Many methods aim to solve the problem, but can handle either images with occlusion only or with arbitrary poses only. In this paper, we propose a unified framework by ignoring the points which cannot be seen under occlusion and extreme poses, in which we get facial parts first by classification and then train regression models to get key points. It leads to higher accuracy when locating the truly existing points without considering the occluded and non-existent points. Besides, we observed that the drift and shape of face detection results affect face alignment .As far as we know, we are the first to explicitly raise the issue and solve it to some extent. Finally, our method outperforms the state-of-the-art methods on AFLW and COFW datasets. It is also comparable to other methods on LFPW dataset.
关键词： extreme poses,convolutional neural networks,occlusion,face alignment,different bounding box
更新于2025-09-04 15:30:14
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Fabrication of vertical alignment liquid crystal cell without forming a conventional polyimide-alignment layer
摘要： A novel preparation method of the vertical alignment polymer film (VAPF) was proposed by polymerisation of the monomers, 2,3-difluoro-4?-[2-(diacryloyl-oxy-hexyl)methyl ester-hexadecyl-oxy]-biphenyl (DFDAMHB) and 2,7-dimethacryloyl-oxy-phenanthrene (DMAPhen), being dissolved in the liquid crystal (LC) material. For obtaining the vertical alignment (VA), the ultraviolet exposure was carried out to the LC cell below the nematic to isotropic transition temperature of the LC material. The VA mode LC cell with the VAPF produced from the monomers DFDAMHB and DMAPhen exhibited enough level of electro-optical and response properties, high voltage holding ratio and low residual direct current voltage.
关键词： vertical alignment polymer film,Liquid crystals,nematic to isotropic transition temperature,monomers,polymerisation
更新于2025-09-04 15:30:14
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Deposition and Determination of Band Alignment of Al2O3/Si Gate Stacks by New CVD Chemistry
摘要： Compared to other precursors, dimethyl aluminum hydride [(CH3)2AlH] has high vapor pressure of 2 torr at room temperature and a potential to form alumina films by CVD/ALD with low carbon impurity. Additionally, low deposition temperature of dimethyl aluminum hydride will avoid the formation of low-k interfacial layer during deposition, which is suitable for the MOS device fabrication. In this study, Al2O3 thin films have been deposited successfully from dimethyl aluminum hydride and O2 to investigate the MOCVD behaviour as well as the observation of the band alignment of deposited Al2O3/Si gate stacks.
关键词： Precursor,High-k gate dielectrics,Band alignment,Thermal stability
更新于2025-09-04 15:30:14
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[IEEE 2018 15th European Radar Conference (EuRAD) - Madrid, Spain (2018.9.26-2018.9.28)] 2018 15th European Radar Conference (EuRAD) - Kernel Extended Local Tangent Space Alignment for SAR Image Classification
摘要： This study proposes a novel local tangent space alignment (LTSA) variant, kernel extended (KE)-LTSA for synthetic aperture radar (SAR) image classification. It attempts on one hand to extract local geometric structures embedded in local neighbourhoods and on the other hand to maximize global interclass separability characterized by the overall distances among different classes. Moreover, it is formulated with kernel technique to obtain better performance than linear counterparts. Experimental results on the MSTAR database demonstrate that the proposed method can significantly improve the classification performance. Results also indicate the robustness when taking into account target variability and neighbourhood size.
关键词： SAR,ATR,MSTAR,local tangent space alignment
更新于2025-09-04 15:30:14
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Self-Aligned Metal Electrodes in Fully Roll-to-Roll Processed Organic Transistors
摘要： We demonstrate the production of organic bottom gate transistors with self-aligned electrodes, using only continuous roll-to-roll (R2R) techniques. The self-alignment allows accurate <5 μm layer-to-layer registration, which is usually a challenge in high-speed R2R environments as the standard registration methods are limited to the millimeter range—or, at best, to tens of μm if online cameras and automatic web control are utilized. The improved registration enables minimizing the overlap between the source/drain electrodes and the gate electrode, which is essential for minimizing the parasitic capacitance. The complete process is a combination of several techniques, including evaporation, reverse gravure, ?exography, lift-off, UV exposure and development methods—all transferred to a continuous R2R pilot line. Altogether, approximately 80 meters of devices consisting of thousands of transistors were manufactured in a roll-to-roll fashion. Finally, a cost analysis is presented in order to ascertain the main costs and to predict whether the process would be feasible for the industrial production of organic transistors.
关键词： roll-to-roll,cost analysis,self-alignment,printing,organic transistor
更新于2025-09-04 15:30:14