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This paper simulates scattering properties of metasurfaces by finite difference time domain(FDTD) method with generalized sheet transition conditions (GSTCs) to alleviate computational burden. It is found that a metasurface can be represented by the electric and magnetic polarization densities, which is related to electromagnetic field by GSTCs. The GSTCs are thereby implemented in 3D FDTD codes and...
Many electromagnetic devices, such as metasurfaces, reflectarray antennas, nano particle arrays, can be modeled as quasi-periodic arrays. Simulation of electromagnetic wave interaction with such arrays are very challenging because they are usually large multi-scale models. In this work, we develop a fast algorithm to model quasi-periodic arrays. In this algorithm, we take advantage of the similarities...
In this article, a new methodology is presented for identification of finite-impulse-response (FIR) models. The central idea is to use a series of stable models of first-order plus time delays (FOPTD) to approximate the dynamics of the process. A quantitative analysis of the modelling error is provided. Compared to the existing basis model approaches, the advantages of the proposed method lie in the...
The surface electric and magnetic susceptibilities and the surface impedance of an array composed of periodic scatterers are derived based on generalized sheet transition conditions. Using these characteristic parameters, the reflection coefficient of a reflectarray element can be readily computed for arbitrary incident angles, polarizations, and frequencies. The detailed procedure is described and...
Planar quasi-periodic arrays are widely used in many electromagnetic devices, such as reflectarray antennas, metasurfaces, nano particle arrays, and etc‥ They can be modeled as elements with geometrical control parameters located at periodic locations. Modeling quasi-periodic arrays are more challenging compared with periodic arrays. The entire array is required during the modeling process due to...
Reflectarray antennas have been widely used in communications and national defense because of their remarkable advantages such as high gain, low loss, low profile, and etc. In the design of reflectarray antennas, the relation between the reflection phase of every element and its dimensions is usually computed through element simulation with infinite periodic boundary conditions. However, this assumption...
A high performance terrain data compression method is proposed based on discrete wavelet transform (DWT) and parallel run-length code. But the implementation of the schemes to solve these models in realistic scenarios imposes huge demands of computing power. Compute Unified Device Architecture (CUDA) programmed, Graphic Processing Units (GPUs) are rapidly becoming a major choice in high performance...
Wide Area Motion Imagery (WAMI) are usually taken from unmaned air vehicles at low frame rates, and having very wide ground coverage. These images serve as rich source for many applications like surveillance, urban planing and traffic monitoring. Thus, understanding WAMI imagery exploitation has been gaining more interest recent years. In this paper, we focus on estimating the pose of vehicles in...
Planar quasi-periodic arrays are widely used in many electromagnetic devices. They can be modeled as elements with geometrical control parameters on periodic locations. In this work we apply the reduced basis method to integral equation solvers for 2D quasi-periodic array modeling. A new basis set based on the varying parameters is constructed through an offline process. Owing to the similarities...
In this paper, we propose a novel Dual-Prior Bayesian Model Fusion (DP-BMF) algorithm for performance modeling. Different from the previous BMF methods which use only one source of prior knowledge, DP-BMF takes advantage of multiple sources of prior knowledge to fully exploit the available information and, hence, further reduce the modeling cost. Based on a graphical model, an efficient Bayesian inference...
With the aggressive scaling of integrated circuit technology, analog performance modeling is facing enormous challenges due to high-dimensional variation space and expensive transistor-level simulation. In this paper, we propose a kernel density based sparse regression algorithm (KDSR) to accurately fit analog performance models where the modeling error is not simply Gaussian due to strong nonlinearity...
Based on Huygens' principle, the equivalence principle algorithm can decompose a large computational domain into several subdomains and model electromagnetic phenomenon efficiently. This paper analyses the numerical projection error of the equivalence principle operator (EPO), i.e., the error of the scattered equivalent currents on the equivalence surfaces projected from the currents inside the surface...
The growing deployment of renewable power generation creates a growing opportunity in "stranded power", power that is generated a close to zero-cost, but not usable by the power grid. We propose to use this stranded power to create a "zero carbon" high-performance computing resource, exploiting the batch computing model to exploit the volatile power efficiently.
Percutaneous transluminal coronary angioplasty (PTCA) has been proved to be a standard solution to most cardiovascular diseases (CVDs). The surgical simulator provides the trainees a new vehicle to learn this skill much more conveniently and effectively. The blood vessel model is at the core of the virtual environment. In this paper, a robust and semi-automatic approach to segment the abdominal aorta...
Adverse drug reactions (ADRs) are a main cause of hospitalization and deaths worldwide. These unanticipated episodes are generally infrequent, but almost all existing ADR signaling techniques are designed to use dataset extracted from spontaneous reporting systems or employed a predefined type of information (e.g., drugs), which suffer from failures to detect unexpected and latent ADRs. In this paper,...
Percutaneous coronary intervention is the gold standard to coronary diseases in the past decades due to much less trauma and quick recovery. However, due to the traits of minimal invasiveness, clinicians have to defeat the difficulties in eye-hand coordination during the procedure, which also makes it a non-trivial task in the catheterization lab. The computer-aided surgical simulation is designed...
For the last decade, remarkable progress has been made in the field of cardiovascular disease treatment. However, these complex medical procedures require a combination of rich experience and technical skills. In this paper, a 3D virtual reality simulator for core skills training in minimally invasive surgery is presented. The system can generate realistic 3D vascular models segmented from patient...
Recently, the development of minimally invasive surgery has led to the emergence of the new research area: minimally invasive vascular surgery simulation. The goal of the surgery simulation is to provide a new way to enable the trainees to obtain the core skills of the techniques. One of the key component of the simulation for core skills training in minimally invasive vascular surgery is how to develop...
In this paper, a novel transmitarray is proposed for high-gain antennas at Ka-band. The element with two-layer structure is designed for simplicity compared with previous work. To improve the element's transmission performance, vias are added to connect two metallic layers through a single dielectric substrate. For the purpose of validation, the new transmitarray is modeled and simulated using a MoM-based...
In fighting the coronary heart diseases, percutaneous coronary intervention is proved to be a powerful and reliable clinical procedure in the modern catheterization labs all over the world. Due to its minimally invasive characteristics, the procedure must be performed in the image-guided way, which makes this important skill very difficult to learn. To make the learning more accessible, a computer-aided...
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