- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Cavity-QED interactions of several atoms
摘要： We study many-atom van der Waals forces arising from reversible atom–field interactions in cavity quantum electrodynamics by using a dressed-state approximation. In the most general case, a single-mode Dicke model for atoms, sharing an arbitrary number of excitations, placed in an imperfect cavity has been developed that leads to the vdW potential of such system. As special cases, we consider the single-excitation Dicke model and also the case of one atom in the presence of multi-photon excitation inside the cavity. In most of the paper, it is assumed that the atoms are distributed symmetrically with respect to the mode structure. This will decouple all asymmetric states, allowing us to ignore them throughout our calculations. The impact of asymmetric states is taken into account for a system wherein one atom, freely placed in a cavity, together with n ? 1 equally-coupled atoms is interacting with the cavity field. By assuming broadened Lorentzian modes instead of sharp ones, the cavity imperfections have been added to the calculations. The position dependence of the effective Rabi frequency is studied for the example of a planar cavity.
关键词： cavity quantum electrodynamics,van der Waals forces,planar cavity,dressed-state approximation,Dicke model,Rabi frequency
更新于2025-09-04 15:30:14
-
[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) - Learning Cross-Modal Deep Embeddings for Multi-Object Image Retrieval using Text and Sketch
摘要： In this work we introduce a cross modal image retrieval system that allows both text and sketch as input modalities for the query. A cross-modal deep network architecture is formulated to jointly model the sketch and text input modalities as well as the the image output modality, learning a common embedding between text and images and between sketches and images. In addition, an attention model is used to selectively focus the attention on the different objects of the image, allowing for retrieval with multiple objects in the query. Experiments show that the proposed method performs the best in both single and multiple object image retrieval in standard datasets.
关键词： cross-modal,image retrieval,sketch,attention model,deep learning,text
更新于2025-09-04 15:30:14
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Fast Sample Generation with Variational Bayesian for Limited Data Hyperspectral Image Classification
摘要： Labeling data for hyperspectral remote sensing image classification is a tedious and cost-intensive task. As a consequence, it is oftentimes necessary to perform classification when only very limited number of labeled training data is available. Several approaches have been proposed to address this problem. A recent proposal is to generate additional synthetic samples from a Gaussian Mixture Model for each class. One challenge with this approach lies in determining the number of components in the GMM. In this paper, we propose an approximation algorithm to select the number of components, namely Variational Bayesian (VB). The main advantage of VB is that it does not require multiple clustering computations in advance. Variational Bayesian not only greatly decreases the computational cost, but also generates comparable or better results in comparison to other methods.
关键词： synthetic data,hyperspectral remote sensing image classification,limited training data,Gaussian mixture model (GMM),Variational Bayesian (VB)
更新于2025-09-04 15:30:14
-
Electromagnetic modeling and analysis of the tapered differential through glass vias
摘要： An analytic model of the tapered differential through glass vias is proposed in this paper. Each expression accounting for the via length, diameter, slope angle and pitch is derived from basic physics and the IMD layer is included, additionally. The RLGC equivalent circuit is veri?ed by comparing the S-parameters resulted from the 3-D full-wave electromagnetic solver High Frequency Simulator Structure (HFSS) and Advanced Design System (ADS). The feature selective validation (FSV) technique is used to as a measure of the comparisons. The proposed model and HFSS results show accordance with each other up to 20 GHz The excellent transmission characteristics (cid:1)3 dB and the of glass substrate re?ect from S-parameters, of which the S21 is about the order of magnitude of 10 the S11 is lower than (cid:1)30 dB till 20 GHz. Moreover, the impact of different con?guration on transmission coef?cient is investigated.
关键词： Glass interposer,Equivalent-circuit model,3D ICs,Differential through glass vias
更新于2025-09-04 15:30:14
-
[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - A Quantitative Model for Estimating the Scale of Photochemically Induced Ischemic Stroke
摘要： Photothrombosis is a technique that can induce ischemic cortical infarcts using the photodynamic effect of anionic xanthene dyes, typically Rose Bengal, to cause occlusion of cerebral blood circulation. The ability to quantitatively predict the scale of the lesion in photothrombotic procedures can offer crucial insight in the development and implementation of light-induced stroke models in animals. In this article, we introduced a quantitative model that could estimate the normalized light intensity distribution in tissue which scatters photons from a collimated beam. We simulated the penetration and scattering profile of light of Rose Bengal’s characteristic absorption wavelengths in mouse cortex. We further illustrated that our model could estimate the spatial extent of effective region under photothrombotic protocols, and how this model can be used to titrate the intensity and geometry of light beams used to generate infarcts of desired dimensional characteristics.
关键词： Rose Bengal,ischemic stroke,Photothrombosis,quantitative model,light scattering
更新于2025-09-04 15:30:14
-
Stable Hall voltages in presence of dynamic quasi-continuum bands in poly(3,4-ethylene-dioxythiophene)
摘要： Topological and thermal disorder complicate the mobility characterization in poly(3,4-ethylenedioxythiophene) systems and presently leaves the exact transport mechanisms not fully understood. Here we show that ac-Hall measured by lock-in amplifier is able to resolve the Hall voltage in semimetallic polymers between room temperature and 32 K. These results are evaluated using an organic random phase model. This accounts for the role of tail states and, particularly, for thermal disorder of molecular semiconductors. We report band mobilities up to 3.7 cm2 V?1 s?1 in semimetallic polymers occurring in delocalized bands that originate from significant electron coherence across the polymer chains.
关键词： Weak localization,Conducting polymers,PEDOT,Hall-effect,Organic phase model,Electron coherence
更新于2025-09-04 15:30:14
-
Application of kinetic flux vector splitting scheme for solving viscous quantum hydrodynamical model of semiconductor devices
摘要： In this article, one-dimensional viscous quantum hydrodynamical model of semiconductor devices is numerically investigated. The model treats the propagation of electrons in a semiconductor device as the flow of a charged compressible fluid. It plays an important role in predicting the behavior of electron flow in semiconductor devices. The nonlinear viscous quantum hydrodynamic models contain Euler-type equations for density and current, viscous and quantum correction terms, and a Poisson equation for electrostatic potential. Due to high nonlinearity of model equations, numerical solution techniques are applied to obtain their solutions. The proposed numerical scheme is a splitting scheme based on the kinetic flux-vector splitting (KFVS) method for the hyperbolic step, and a semi-implicit Runge-Kutta method for the relaxation step. The KFVS method is based on the direct splitting of macroscopic flux functions of the system on the cell interfaces. The second order accuracy of the scheme is achieved by using MUSCL-type initial reconstruction and Runge-Kutta time stepping method. Several case studies are considered. For validation, the results of current scheme are compared with those obtained from the splitting scheme based on the NT central scheme. The effects of various parameters such as device length, viscosities, different doping and voltage are analyzed. The accuracy, efficiency and simplicity of the proposed KFVS scheme validates its generic applicability to the given model equations.
关键词： Numerical simulation,Kinetic flux-vector splitting scheme,Semiconductor devices,Viscous quantum hydrodynamic model
更新于2025-09-04 15:30:14
-
The Effect of Microwave Annealing of Reliability Characteristics on Amorphous IGZO Thin Film Transistors
摘要： Amorphous oxide semiconductors (AOSs) are attracted much attention due to high mobility, low temperature deposition, ?exible, transmission, and uniformity. The thin ?lm transistors (TFTs) with a-IGZO thin ?lm as active layer perform higher ?eld-effect mobility (>10 cm2/V · S), larger I on/I off ratio (>106), smaller subthreshold swing and better stability against electrical stress. LaAlO3/ZrO2 is employed as gate electrode and gate dielectric layer for a-IGZO TFTs, under the premise that performance of a-IGZO TFTs without decreasing. Due to the good selectivity of energy transformation and rapid heating rate, microwave annealing is applied to improve the device reliability in the investigation. With adjusting the parameter of microwave annealing, the effect on reliability characteristics of a-IGZO TFTs is studied.
关键词： Microwave Annealing,Stretched-Exponential Model,IGZO TFTs,Positive Bias Stress
更新于2025-09-04 15:30:14
-
[IEEE 2018 21st International Conference on Information Fusion (FUSION 2018) - Cambridge (2018.7.10-2018.7.13)] 2018 21st International Conference on Information Fusion (FUSION) - Motion State Classification for Automotive LIDAR Based on Evidential Grid Maps and Transferable Belief Model
摘要： Point clouds generated by Lidar sensors provide detailed information about the geometry of the environment. Yet they lack semantic information, which is paramount for the choice of choosing the appropriate modelling, e.g. within a tracking system. This contribution tries to provide semantic information in the form of stationary and dynamic classification by applying a transferable belief model. In particular, we build an occupancy grid representation of the environment and correct it with a tailored transferable belief model that accounts for inconsistencies as well as non-local features. Based on these results we define a classifier that distinguishes between stationary and dynamic cells. The presented algorithm is evaluated qualitatively on real-world Valeo Scala LIDAR data and quantitatively based on an IPG Carmaker simulation.
关键词： motion classification,transferable belief model,semantic information,LIDAR,occupancy grid
更新于2025-09-04 15:30:14
-
Impact of the Acquisition Geometry of Very High-Resolution Pléiades Imagery on the Accuracy of Canopy Height Models over Forested Alpine Regions
摘要： This work focuses on the accuracy estimation of canopy height models (CHMs) derived from image matching of Pléiades stereo imagery over forested mountain areas. To determine the height above ground and hence canopy height in forest areas, we use normalised digital surface models (nDSMs), computed as the differences between external high-resolution digital terrain models (DTMs) and digital surface models (DSMs) from Pléiades image matching. With the overall goal of testing the operational feasibility of Pléiades images for forest monitoring over mountain areas, two questions guide this work whose answers can help in identifying the optimal acquisition planning to derive CHMs. Specifically, we want to assess (1) the benefit of using tri-stereo images instead of stereo pairs, and (2) the impact of different viewing angles and topography. To answer the first question, we acquired new Pléiades data over a study site in Canton Ticino (Switzerland), and we compare the accuracies of CHMs from Pléiades tri-stereo and from each stereo pair combination. We perform the investigation on different viewing angles over a study area near Ljubljana (Slovenia), where three stereo pairs were acquired at one-day offsets. We focus the analyses on open stable and on tree covered areas. To evaluate the accuracy of Pléiades CHMs, we use CHMs from aerial image matching and airborne laser scanning as reference for the Ticino and Ljubljana study areas, respectively. For the two study areas, the statistics of the nDSMs in stable areas show median values close to the expected value of zero. The smallest standard deviation based on the median of absolute differences (σMAD) was 0.80 m for the forward-backward image pair in Ticino and 0.29 m in Ljubljana for the stereo images with the smallest absolute across-track angle (?5.3?). The differences between the highest accuracy Pléiades CHMs and their reference CHMs show a median of 0.02 m in Ticino with a σMAD of 1.90 m and in Ljubljana a median of 0.32 m with a σMAD of 3.79 m. The discrepancies between these results are most likely attributed to differences in forest structure, particularly tree height, density, and forest gaps. Furthermore, it should be taken into account that temporal vegetational changes between the Pléiades and reference data acquisitions introduce additional, spurious CHM differences. Overall, for narrow forward–backward angle of convergence (12?) and based on the used software and workflow to generate the nDSMs from Pléiades images, the results show that the differences between tri-stereo and stereo matching are rather small in terms of accuracy and completeness of the CHM/nDSMs. Therefore, a small angle of convergence does not constitute a major limiting factor. More relevant is the impact of a large across-track angle (19?), which considerably reduces the quality of Pléiades CHMs/nDSMs.
关键词： acquisition geometry,canopy height model,forested mountain,very high-resolution Pléiades imagery,accuracy assessment
更新于2025-09-04 15:30:14