Yong Cao

• Ph.D.
• Virginia Tech

In this paper, we present an asymptotic-preserving conservative Semi-Lagrangian (CSL) scheme for the Vlasov-Maxwell system in the quasi-neutral limit, where the Debye length is negligible compared to the macroscopic scales of interest. The proposed method relies on two key ingredients: the CSL scheme and a reformulated Maxwell equation (RME). The C...

In this paper, we present a novel kinetic scheme termed the Energy Conserving Semi-Lagrangian (ECSL) for the Vlasov-Ampère system. The novelty of the ECSL is that it retains the efficiency of the explicit scheme while simultaneously maintaining energy conservation and unconditional stability properties of the implicit scheme without relying on nonl...

The demands for wider speed range and longer endurance of hypersonic vehicles make the flight state transition an issue to be considered. To get a fundamental understanding of the thermal response characteristics of su-percritical fuel under varying operation conditions, a series of experimental and numerical studies have been conducted in this res...

In this paper, the immersed finite element (IFE) coupled with the conservative semi-Lagrangian (CSL) kinetic scheme is developed for plasma-material interactions. The proposed method (IFE-CSL) enjoys respective advantages of the IFE and CSL, i.e, the flexibility and efficiency for treating complex boundary conditions, mass conservation and being fr...

During the cracking process of hydrocarbon fuel, the heat would be converted into internal energy and chemical energy. It is necessary to study the conversion relationship between internal energy and chemical energy in the above-mentioned energy conversion process, which is of great significance for the efficient use of fuel heat sinks in the regen...

severe working environment causes gas turbines to break down, which can directly affect their performance. Research on the diagnostic methods for gas turbine faults, such as, gas path faults and sensor failures, has always raised concerns. However, traditional fault diagnosis algorithms mostly use instantaneous data rather than time-series data, be...

A 2D-3V finite-element particle-in-cell model, which is applied to simulate the radial-azimuthal plane near the exit of Hall thrusters, has been presented to investigate the influence of axial oscillation on electron cyclotron drift instability (ECDI) and anomalous cross field electron transports. The simplified theoretical analysis about the ECDI...

One of the main factors that limit the lifetime of the Hall effect Thrusters (HETs) is the erosion of the acceleration channel caused by the flux of energetic ions. The magnetic field that is curved and convex towards the anode has been widely used in HETs because of its role in reducing the divergence angle of the ion beam and the channel wall ero...

A 2D-3V implicit immersed-finite-element particle-in-cell (IFE-PIC) model has been introduced to investigate the RF self-bias accelerating system applied in the RF ion thruster. A set of holes in a two-grid system with slit apertures is simulated in Cartesian coordinates. The characteristics of the plasma plume, such as the ion density, the neutral...

Efficient utilization of chemical heat sinks and enhancement of heat transfer are key issues for the thermal protection of advanced hypersonic flight vehicles. However, the influences of residence time on the pyrolysis and convection heat transfer of hydrocarbon fuel are different, which is important for the design and optimization of cooling syste...

The heat transfer mechanism of hydrocarbon fuels is important for designing cooling structures for hypersonic craft. This study investigated the supercritical heat transfer characteristics of aviation kerosene RP-3 with pyrolysis, and proposed a method for establishing a new empirical correlation to estimate the heat transfer characteristics. The r...

Because the generator power-measuring equipment is often accompanied by electrical interference in a complex electromagnetic environment in an actual thermal power plant, the output signal will change or even distort while it passes through the devices of acquisition and conversion. Several practical cases have found that the abnormal generation ch...

Since flexible peak shaving has been implemented in a growing number of high-power turbo-generator sets in the power grid owing to increasing demand, the load control performance of steam turbines directly affects the safety and efficiency of the unit operation. Load-following issues, especially load mutation, weaken the frequency control performan...

The study of the characteristics of the plasma-wave interaction in helicon plasmas near the lower hybrid frequency has been carried out. The (0D) dispersion relation is derived to analyse the properties of the wave propagation and the 1D cylindrical plasma-wave interaction model is established to investigate the power deposition and implement the p...

Anomaly detection of steam turbines is to recognize infrequent instances within sensor data that plays a vital role in stable power supply. Machine learning models have been applied to diagnose the faults of turbine and verified useful for identifying engine problem. To detect anomalies of steam turbines with machine learning methods, here, an appr...

The fluid flow and heat transfer of hydrocarbon fuel play a significant role in developing regenerative cooling technology for advanced aeroengines. Numerical simulations have been conducted to investigate the flow and heat transfer characteristics of China RP-3 aviation kerosene with pyrolysis in a 3D, 90° bend, square cooling channel around the c...

Air is considered as the feasible internal coolant to cool the vane of the gas turbines for the conventional cooling method all the time. However, the traditional cooling method gradually is difficult to meet the demand of increasing inlet temperature for the high-pressure turbine. Because of the excellent heat transfer performance of liquid metal,...

In this paper, a conservative semi-Lagrangian (CSL) kinetic scheme coupled with an implicit finite element method (IFEM) is developed for multidimensional electromagnetic plasma simulations. The present method (CSL-IFEM) enjoys the respective advantages of the CSL and IFEM, including mass conservation, high-order spatial accuracy, as well as being...

False information on the Internet is being heralded as serious social harm to our society. To recognize false text information, in this paper, an effective method for mining text features is proposed in the field of false drug advertisements. Firstly, the data of false drug advertisements and real drug advertisements were collected from the officia...

Introduction: Circular RNAs (circRNAs) are an endogenous mircoRNA sponge that could act as potential biomarkers for the diagnosis and treatment of diseases. However, the role of circRNAs in asthma is far from clear. Objective: The aim of this study is to assess the diagnostic and therapeutic value of hsa_circ_0002594 for T helper (Th) 2-mediated...

Background: Circular RNAs (circRNAs) are a novel class of noncoding RNAs that regulate gene expression at the transcriptional or posttranscriptional level. According to recent studies, circRNAs are involved in the pathogenesis of cancer, but the roles of circRNAs in lung adenocarcinoma are largely unknown. Methods: In this study, we identified a...

In order to simulate the Kaufman-type discharge problems, a fully decoupled iterative method with anisotropic immersed finite elements on Cartesian meshes is proposed, especially for a three-dimensional (3D) non-axisymmetric anisotropic hybrid model which is more difficult than the axisymmetric or isotropic models. The classical hybrid model, which...

This paper develops a two-dimensional implicit particle-in-cell model, which considers algorithms without and with magnetic field, based on the anisotropic immersed-finite-element method. The direct implicit particle-in-cell (DIPIC) algorithm is utilized to track the movement of electrons and ions, while the anisotropic immersed-finite-element meth...

Wan, J.; Yao, K.; Ren, G.R.; Cao, Y.; Wang, W.; Zhao, X.X., and Yu, J.L., 2020. Coastal wind speed's multi-parameter forecasting based on quantitative measurement of its predictability. In: Bai, X. and Zhou, H. (eds.), Advances in Water Resources, Environmental Protection, and Sustainable Development. Journal of Coastal Research, Special Issue No....

Surface coking is significantly affected by the mass transfer of regenerative cooling system in advanced aeroengines. On the basis of the detailed chemical kinetic mechanism of China No. 3 jet fuel (also known as RP-3), the flowfield and surface coking of RP-3 in the curved cooling channel surrounding around the cavity flameholder of scramjet are n...

How to mitigate coke and improve heat sink is the critical factor for thermal management system of turbine‐based combined cycle (TBCC). A novel thermal management method using multi‐stage coating structure to mitigate coke and improve heat sink is developed in this study. The multi‐stage coating structure includes catalytic steam reforming (CSR) an...

In this paper, the discrete unified gas kinetic scheme (DUGKS), which is a novel direct kinetic method, is developed for a reformulated BGK-Vlasov-Poisson system in all electrostatic plasma regimes characterized by a wide range of Knudsen number and normalized Debye length. The current scheme is constructed for multiscale plasma simulation, while t...

Background: Since December 2019, an outbreak of Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, and is now becoming a global threat. We aimed to delineate and compare the immunologic features of severe and moderate COVID-19. Methods: In this retrospective study, the cli...

Background Since late December, 2019, an outbreak of pneumonia cases caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, and continued to spread throughout China and across the globe. To date, few data on immunologic features of Coronavirus Disease 2019 (COVID-19) have been reported. Methods In this single-c...

Tartrate-resistant acid phosphatase 5 (TRAP/ACP5) has been shown to involve the development and prognosis of multiple tumors in previous studies; however, the mechanism in lung cancer is still unclear, and thus this study investigated the role of ACP5 in the progression of lung adenocarcinoma. After a series of in vitro and in vivo experiments, we...

The wall catalytic steam reforming (WCSR) is expected to be used in chemical recuperative cycle of scramjet because of its high chemical heat sink and low coke deposition. Therefore, a numerical model is established and validated based on experiments to improve utilization of chemical heat sink, generated from WCSR at supercritical pressures. The n...

Anisotropic diffusion is important to many different types of common materials and media. Based on structured Cartesian meshes, we develop a three‐dimensional non‐homogeneous immersed finite element (IFE) method for the interface problem of anisotropic diffusion, which is characterized by an anisotropic elliptic equation with discontinuous tensor c...

In this paper, we propose a microscale liquid oscillator using electrowetting-on-dielectric (EWOD). Specifically, a mesoscale liquid bridge (LB) between two horizontal surfaces with EWOD is considered. When EWOD is applied, the solid surface becomes more hydrophilic, and hence the contact angle (CA) is reduced. Following the activation of EWOD, the...

The cover image is based on the Original Article Hsa_circ_0005519 increases IL‐13/IL‐6 by regulating hsa‐let‐7a‐5p in CD4+ T cells to affect asthma by Zhenli Huang et al, DOI: 10.1111/cea.13445.

Background Circular RNAs (circRNAs) are a class of non‐coding RNAs that could serve as novel biomarkers for the diagnosis and treatment of diseases. We hypothesized that circRNAs of CD4⁺ T cells are involved in asthma. Objective In this study, we investigated the circRNA expression profile and the possible mechanism by which hsa_circ_0005519 parti...

In order to reduce the erosion of the ion thruster accelerator grid, which is caused by charge-exchange (CEX) ions, the 2-grid optical system is added to a decelerator grid to block the reflux CEX ions. The previous experiment and simulation results have proven that the decelerator grid can effectively reduce the Pit and Groove erosion. However, th...

Objective The aim of the study was to determine the expression profile of long noncoding RNAs (lncRNAs) in CD4⁺ T cells from COPD patients and explore the clinical value of the lncRNAs. Methods First, microarray analysis was performed. Differentially expressed lncRNAs were validated by quantitative real-time reverse transcription-PCR (qRT-PCR) in...

The aim of the study was to determine the expression profiles of message RNAs and long non-coding RNAs in CD4+T cells of asthmatic patients and to explore the clinical value and biological function. Expression profiles in CD4+T cells of asthmatic patients and healthy controls were analyzed by microarray. We found 2725 lncRNAs and 3167 mRNAs differe...

A coupled population balance sectional method (PBSM) coupled with computational fluid dynamics (CFD) is presented to simulate the capture of aerosolized oil droplets (AODs) in a range hood exhaust. The homogeneous nucleation and coagulation processes are modeled and simulated with this CFD-PBSM method. With the design angle, α of the range hood exh...

In this paper, the mechanical properties of thermoelectric Mg2Si are investigated using molecular dynamics (MD) method, with Mg2Si in the forms of bulk, nanofilm, and nanowire, respectively. The effects of the Mg vacancy on the mechanical properties of Mg2Si in these three forms are studied in details. First of all, the equilibrium state of Mg2Si i...

Surface evolution is an unavoidable issue in engineering plasma applications. In this article an iterative method for modeling plasma-surface interactions with moving interface is proposed and validated. In this method, the plasma dynamics is simulated by an immersed finite element particle-in-cell (IFE-PIC) method, and the surface evolution is mod...

Asthma is a chronic T helper type 2 (Th2) cell-mediated inflammatory disease characterized by airway hyperresponsiveness (AHR) and airway inflammation. Although the majority of patients with asthma can achieve a good level of control with existing treatments, asthma runs a chronic course and the effectiveness of current treatment is not satisfactor...

The particle-in-cell (PIC) method has been widely used for plasma simulation, because of its noise-reduction capability and moderate computational cost. The immersed finite element (IFE) method is efficient for solving interface problems on Cartesian meshes, which is desirable for PIC method. The combination of these two methods provides an effecti...

Background: C/EBP homologous protein (CHOP), a marker of endoplasmic reticulum (ER) stress, exhibits aberrant expression patterns during the development of asthma. However, its exact role in asthma pathogenesis is not fully understood. Objectives: We aimed to determine the function and mechanism of CHOP in the pathogenesis of allergic asthma in...

Sensemaking of large graphs, specifically those with millions of nodes, is a crucial task in many fields. Automatic graph layout algorithms, augmented with real-time human-in-the-loop interaction, can potentially support sensemaking of large graphs. However, designing interactive algorithms to achieve this is challenging. In this paper, we tackle t...

Introduction Tc17 cells are interleukin (IL)-17-producing CD8⁺ T cells and have been found to participate in the development of allergic asthma. Interleukin-23 is a cytokine that may be involved in modulating the IL-17 response via Th17 cells. This study aimed to investigate whether IL-23 also has immunomodulatory effects on Tc17 cells. Material a...

This paper presents the Animated VISualization Tool (AVIST), an exploration-oriented data visualization tool that enables rapidly exploring and filtering large time series multidimensional datasets. AVIST highlights interactive data exploration by revealing fine data details. This is achieved through the use of animation and cross-filtering interac...

Accumulating evidence suggests that chemokine (C-X-C motif) ligand 12 (CXCL12) and its receptor chemokine (C-X-C motif) receptor 4 (CXCR4) may contribute to the pathogenesis of allergic asthma. However, the underlying molecular mechanisms remain to be fully understood. T-helper 17 cells (Th17) and T-cytotoxic 17 cells (Tc17) have been implicated in...

C/EBP homologous protein (Chop) has been shown to have altered expression in patients with idiopathic pulmonary fibrosis (IPF), but its exact role in IPF pathoaetiology has not been fully addressed. Studies conducted in patients with IPF and Chop(-/-) mice have dissected the role of Chop and endoplasmic reticulum (ER) stress in pulmonary fibrosis p...

In this paper, we present an upper human body tracking system with agent-based architecture. Our agent-based approach departs from process-centric model where the agents are bound to specific processes, and introduces a novel model by which agents are bound to the objects or sub-objects being recognized or tracked. To demonstrate the effectiveness...

Interleukin (IL-21) is a member of the type I cytokine family with sequence homology to IL-2, IL-4, and IL-15. IL-21 has been reported to improve symptoms of allergic rhinitis in mice. In this study we examined whether IL-21 signaling involved in allergic airway inflammation and remodeling in vivo by using ovalbumin (OVA)-induced chronic asthma mod...

Chemokine (C-X-C motif) ligand 12 (CXCL12) and its receptor chemokine receptor 4 (CXCR4) have been recognized to play a crucial role in the pathogenesis of bronchial asthma, but the underlying molecular mechanisms are yet to be fully addressed. In the present report we demonstrated that CXCL12/CXCR4 signaling mediates allergic airway inflammation t...

Interleukin (IL)-17 has been implicated in the pathogenesis of asthma and the progression of airway inflammation. Here, we used a model of allergic asthma and found that the frequencies of IL-17-secreting T helper (Th)17 and CD8 (Tc)17 cells were both significantly increased, as was the expression of the CC chemokine receptor (CCR2) on the surface...

Asthma is characterized by airway inflammation, mucus overproduction, and airway hyperreactivity. Cytokines, especially T helper 2-derived cytokines interleukin (IL)-4, IL-5, and IL-13, are involved in the pathogenesis of asthma. IL-21 has a variety of effects on the immune system. However, the contribution of IL-21 to the development of allergic d...

A “Name Disambiguator” provides various techniques for implementing an interactive framework for resolving or disambiguating entity names (associated with objects such as publications) for entity searches where two or more same or similar names may refer to different entities. More specifically, the Name Disambiguator uses a combination of user inp...

Whether CD8+ IL-17-producing T cells, namely Tc17 cells, play a role in asthma has not been determined. The aim of this study was to evaluate and compare the frequency of peripheral blood Th17 cells and Tc17 cells in asthmatic patients. In addition, the number, ratio and distribution of Th17 cells and Tc17 cells in the lung tissue and splenocytes o...

We present a crowd model informed by common ground theory to accommodate high-level socially aware behavioral realism of characters in crowd simulations. In our approach, group members maintain group cohesiveness by communicating and adapting their behaviors to each other. The resulting character behaviors in animations form a consequential chain i...

In many research domains, such as mechanical engineering, game development and virtual reality, a typical output model is usually produced in a multi-object manner for efficient data management. To have a complete description of the whole model, tens of thousands of, or even millions of, such objects are created, which makes the entire dataset exce...

This paper presents a multi-agent model for large crowd simulations that addresses the need for socially plausible coordination behavior. A computational model for multi-agent coordination informed by well-established common ground theory is proposed. We introduce the idea of macro- and micro-coordination strategies that allow agent-based simulatio...

Past research on multi-agent simulation with cooperative reinforcement learning (RL) focuses on developing sharing strategies that are adopted and used by all agents in the environment. In this paper, we target situations where this assumption of a single sharing strategy that is employed by all agents is not valid. We seek to address how agents wi...

Social interaction and group coordination are important factors in the simulation of human crowd behavior. To date, few simulation methods have been informed by models of human group behavior from the social science studies. In this paper we advance a computational model informed by Common Ground (CG) Theory that both inherits the social realism pr...

This paper presents a framework for crowd modeling that produces socially plausible animation behaviors. Our high-level behavioral model is able to produce appropriate animated behavior that includes synchronized body-orientation and gesture of individual actors within the simulation. Because the model operationalizes a well-founded social-linguist...

Rendering massive 3D models has been recognized as a challenging task. Due to the limited size of GPU memory, a massive model with hundreds of millions of primitives cannot fit into most of modern GPUs. By applying parallel Level-Of-Detail (LOD), as proposed in [1], transferring only a portion of primitives rather than the whole to the GPU is suffi...

In this paper, we introduce a GPU-accelerated visual analytics tool, AVIST. By adopting the in-situ visualization architecture on the GPUs, AVIST supports real-time data analysis and visualization of massive scale datasets, such as VAST 2012 Challenge dataset. The design objective of the tool is to identify temporal patterns from large and complex...

Identifying appropriate spatial scales is critically important for assessing health, attributing data, and guiding management actions for rivers. We describe a process for identifying a three-level hierarchy of spatial scales for Michigan rivers. Additionally, we conduct a variance decomposition of fish occurrence, abundance, and assemblage metric...

Training agents in a virtual crowd to achieve a task can be accomplished by allowing the agents to learn by trial-and-error and by sharing information with other agents. Since sharing enables agents to potentially reach optimal behavior more quickly, what type of sharing is best to use to achieve the quickest learning times? This paper categorizes...

Rendering massive 3D models in real-time has long been recognized as a very challenging problem because of the limited computational power and memory space available in a workstation. Most existing rendering techniques, especially level of detail (LOD) processing, have suffered from their sequential execution natures. We present a GPU-based approac...

Large crowds are seldom made up solely of a mass of individuals. They typically also include large collections of small groups. However the most of existing approaches to crowd modeling treat a crowd either as a collection of isolated individuals, each maintaining its own goal, or as an aggregated entity in which large number of individuals share t...

Inaccurate perception of distances is a known problem within virtual environments. We hypothesize that the inclusion of virtual characters within these environments can improve an observer's ability to judge distances and achieve accurate spatial understanding. We have conducted an empirical study using a desktop display of a small scale environmen...

Compared with full volume rendering, isosurface rendering has several well recognized advantages in efficiency and accuracy. However, standard isosurface rendering has some limitations in effectiveness. First, it uses a monotone colored approach and can only visualize the geometry features of an isosurface. The lack of the capability to illustrate...

Modern graphics processing units (GPUs) are commodity data-parallel coprocessors capable of high performance computation and data throughput. It is well known that the GPUs are ideal implementation platforms for image processing applications. However, the level of efforts and expertise to optimize the application performance is still substantial. T...

Today, multi-electrode arrays (MEAs) capture neuronal spike streams in real time, thus providing dynamic perspectives into brain function. Mining such spike streams from these MEAs is critical towards understanding the firing patterns of neurons and gaining insight into the underlying cellular activity. However, the acquisition rate of neuronal dat...

Multi-electrode arrays (MEAs) provide dynamic and spatial perspectives into brain function by capturing the temporal behavior of spikes recorded from cultures and living tissue. Understanding the firing patterns of neurons implicit in these spike trains is crucial to gaining insight into cellular activity. We present a solution involving a massivel...

Many-core architecture has become an emerging and widely adopted platform for parallel computing. Computer animation researches can harness this advance in high performance computing with better understanding of the architecture and careful consideration of several important parallel algorithm design issues, such as computation-to-core mapping, loa...

In modern games, rendering a massive scene with a large number of animated character is imminent and a very challenging task. In this paper, we present a real-time crowd rendering system on GPUs with a special focus on how to preserve texture appearance in progressive LOD-based mesh simplification algorithms. Our results show that the proposed para...

One of the most common practices in river research and management is to divide river network into more ecologically meaningful and operationally manageable spatial units. The Great Lakes Regional River Database and Classification System was developed for the four-state region of Illinois, Michigan, New York, and Wisconsin by dividing river network...

This meta-analysis was performed to evaluate the difference of the therapeutic efficacy and adverse effects of leukotriene receptor antagonist and theophylline added to inhaled corticosteroids in adult asthma. Databases were searched for studies published through Nov, 2010. Randomized-controlled trials containing inhaled corticosteroids plus leukot...

Image segmentation techniques using fuzzy connectedness (FC) principles have shown their effectiveness in segmenting a variety of objects in several large applications. However, one challenge in these algorithms has been their excessive computational requirements when processing large image datasets. Nowadays, commodity graphics hardware provides a...

In volume rendering, most optical models currently in use are based on the assumptions that a volumetric object is a collection of particles and that the macro behavior of particles, when they interact with light rays, can be predicted based on the behavior of each individual particle. However, such models are not capable of characterizing the coll...

Computational steering integrates modeling, computation, data analysis, visualization, and data input components of a simulation. Since the simulation space is, in general, very large and continuous, selecting discrete simulation points that can reasonably represent the whole simulation space is difficult. We need to interpolate the "missing" value...

— Real-time visualization is an important tool for immediately inspecting results for scientific simulations. Graphics Processing Units (GPUs) as commodity computing devices offer massive parallelism that can greatly improve performance for data-parallel applications. However, a single GPU provides limited support which is only suitable for smaller...