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Full-Text Articles in Computer Engineering
Accounting For Failures In Delay Analysis For Wirelesshart Networks , Abusayeed Saifullah, Paras Babu Tiwari, Bo Li, Chenyang Lu Lu@Wustl.Edu
Accounting For Failures In Delay Analysis For Wirelesshart Networks , Abusayeed Saifullah, Paras Babu Tiwari, Bo Li, Chenyang Lu Lu@Wustl.Edu
All Computer Science and Engineering Research
WirelessHART networks are gaining ground as a real-time communication infrastructure in industrial wireless control systems. Because wireless communication is often susceptible to transmission failures in industrial environments, it is essential to account for failures in the delay analysis for realtime flows between sensors and actuators in process control. WirelessHART networks handle transmission failures through retransmissions using dedicated and shared time slots through different paths in the routing graphs. While these mechanisms for handling transmission failures are critical for process control requiring reliable communication, they introduce substantial challenges to worst-case end-to-end delay analysis for real-time flows. This paper presents the first …
Correction Of An Augmentation Bound Analysis For Parallel Real-Time Tasks, Abusayeed Saifullah, Kunal Agrawal, Chenyang Lu, Christopher Gill
Correction Of An Augmentation Bound Analysis For Parallel Real-Time Tasks, Abusayeed Saifullah, Kunal Agrawal, Chenyang Lu, Christopher Gill
All Computer Science and Engineering Research
This paper proposes some significant corrections in a recent work of Lakshmanan et al on parallel task scheduling. Lakshmanan et al have proposed a transformation of parallel tasks into sequential tasks, and have claimed a resource augmentation bound of 3:42 for partitioned deadline monotonic (DM) scheduling of the transformed tasks. We demonstrate that their analysis for resource augmentation bound is incorrect. We propose a different technique for task transformation that requires a resource augmentation bound of 5 for partitioned DM scheduling.
Early Warning System: Relay Sensor Deployment & Network Reliability Analysis, Zhicheng Yang
Early Warning System: Relay Sensor Deployment & Network Reliability Analysis, Zhicheng Yang
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In this project, we continued Dr. Chipara's study, which developed an early warning system (EWS) to detect the vital signs of patients in order to help doctors to intervene in time [1]. Since the number of wards increased, the environment our system faced with became more complicated and our network became more sensitive. This project focused on finding reasons on the relays that didn't work and doing a reliability analysis on the network in one ward our study covered.
Ride: A Mixed-Mode Control Interface For Mobile Robot Teams, Erik Karulf, Marshall Strother, Parker Dunton, William D. Smart
Ride: A Mixed-Mode Control Interface For Mobile Robot Teams, Erik Karulf, Marshall Strother, Parker Dunton, William D. Smart
All Computer Science and Engineering Research
There is a growing need for robot control interfaces that allow a single user to effectively control a large number of mostly-autonomous robots. The challenges in controlling such a collection of robots are very similar to the challenges of controlling characters in some genres of video games. In this paper, we argue that interfaces based on elements from computer video games are effective tools for the control of large robot teams. We present RIDE, the Robot Interactive Display Environment, an example of such an interface, and give the results of initial user studies with the interface, which lend support to …
Kinect Hand Recognition And Tracking, Alex Drake
Kinect Hand Recognition And Tracking, Alex Drake
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he goal of this research project was to be able to identify and track a hand using the depth image from a Microsoft Kinect. The ability to do this would have uses in sign language recognition, rehabilitation, and gesture recognition amongst others. The Microsoft Kinect is currently capable of identifying and tracking whole bodies. Our approach was to follow the method that Microsoft used but apply it to detailed hand recognition instead of the body. The basic strategy they used was to take a large amount of labeled depth data and build a decision tree to identify which part of …
Specializing Interfaces For Citizen Science Segmentation Of Volumetric Data, Michelle Vaughan, Cindy Grimm, Ruth Sowell, Robert Pless, Stephen Kobourov
Specializing Interfaces For Citizen Science Segmentation Of Volumetric Data, Michelle Vaughan, Cindy Grimm, Ruth Sowell, Robert Pless, Stephen Kobourov
All Computer Science and Engineering Research
Segmentation of 3D and time-varying volumetric (4D) image data is considered a time and resource intensive bottleneck in scientific endeavors. Automatic methods are becoming more reliable, but many data sets still require manual intervention. This can mainly be attributed to the characteristics of the image data not being amenable to automated methods, the existence of variations in or poor image quality, or the need for an expert to review and edit results from an automatic technique. Manually segmenting volumetric data is a challenge even for those more experienced. Understanding the 3D nature of the data and navigating through the 3D …
Just Draw It! A 3d Sketching System, Cindy Grimm, Pushkar Joshi
Just Draw It! A 3d Sketching System, Cindy Grimm, Pushkar Joshi
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We present a system for sketching in 2D to create 3D curves. The interface is light-weight, pen-based, and based on observations of how artists sketch on paper.
Data Collection And Performance Monitoring Of Real-Time Parallel Systems , Mahesh Mahadevan
Data Collection And Performance Monitoring Of Real-Time Parallel Systems , Mahesh Mahadevan
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Instrumentation and log data monitoring are important features present in many different applications today that are used in analysis of a system behaviour. They are largely used in collection of key information from the system which might allow us to describe or establish certain facts about the behavior of the system. Instrumentation in any application usually comes along with its overheads. In some cases , code for instrumentation might become more expensive on the underlying resources than the application itself. For many applications, especially real-time applications , this overhead can cause serious and often catastrophic system failures. Collecting useful information …
A 3d Selection & Query Tool For The Geneatlas Project, Donald Mccurdy
A 3d Selection & Query Tool For The Geneatlas Project, Donald Mccurdy
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In this project, I present an application to view, interact with, and search 3D medical volumes as part of the GeneAtlas project.
Common Dma Engine Interface, Roger Alessi
Common Dma Engine Interface, Roger Alessi
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Circuit boards with Field Programmable Gate Arrays (FPGAs) have a historically diverse set of standards for communicating with other devices. This provides a challenge for developers creating FPGA applications and makes migration of applications from one board or FPGA to another difficult. Many board manufacturers, including Xilinx and GiDEL, create boards with Peripheral Component Interconnect Express (PCIe) buses. PCIe provides a low-level standard for transferring data between a Central Processing Unit (CPU) and an FPGA, and these manufacturers have designed Direct Memory Access (DMA) engines to implement the standard. However, each manufacturer’s DMA engines do not share a standard interface, …
A Memory Access Model For Highly-Threaded Many-Core Architectures, Lin Ma, Kunal Agrawal, Roger D. Chamberlain
A Memory Access Model For Highly-Threaded Many-Core Architectures, Lin Ma, Kunal Agrawal, Roger D. Chamberlain
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Many-core architectures are excellent in hiding memory-access latency by low-overhead context switching among a large number of threads. The speedup of algorithms carried out on these machines depends on how well the latency is hidden. If the number of threads were infinite, then theoretically these machines should provide the performance predicted by the PRAM analysis of the programs. However, the number of allowable threads per processor is not infinite. In this paper, we introduce the Threaded Many-core Memory (TMM) model which is meant to capture the important characteristics of these highly-threaded, many-core machines. Since we model some important machine parameters …
Building A Skeleton Of A Human Hand Using Microsoft Kinect, Jed Jackoway
Building A Skeleton Of A Human Hand Using Microsoft Kinect, Jed Jackoway
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The goal of the project was to reconstruct the skeleton of a Microsoft Kinect user’s hand. Out of the box, Kinect reconstruct the skeleton of users’ bodies, but it only does large joints, such that the hand is given a location on the general skeleton, but the specifics of the fingers and fist are not actually calculated.
The Clear Channel Prior, Devorah Langsam
The Clear Channel Prior, Devorah Langsam
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Capturing imagery from outdoor cameras provides a large amount of information about a scene. The true surface appearances of elements in a scene, however, are often incorrectly represented in images. To get a better representation of the scene it is necessary to separate the effects of the underlying reflectance, illumination, and fog in the image. The goal of the dark channel prior is to eliminate the effects of haze in outdoor images and recover the true surface reflectance image for the scene.
Rapid Development Environments For Therapy Games: Looking Glass Therapy Games For Cerebral Palsy Treatment Utilizing The Kinect, Melynda Eden
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Cerebral palsy is a group of neurological disorders that impair body movement, muscle coordination, hearing, vision, and cognitive function. Symptoms vary but can include muscle weakness, muscle and joint tightness, abnormal or unsteady gait, seizures, learning disabilities, speech problems, as well as hearing or vision problems [1]. Although cerebral palsy cannot be cured, treatments such as physical and occupational therapy can greatly help affected children develop motor skills needed to increase mobility and foster independence [2]. Computer based therapy games have shown promise in helping stroke survivors recover from stroke [3]. Initially, stroke therapy games developed in Looking Glass utilized …
Foveon F13 Camera, David Shelley
Foveon F13 Camera, David Shelley
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Most high-fidelity digital cameras currently available obtain their images using technology where individual pixels can only acquire a single color. Since the acquisition of multiple colors is necessary to capture a full colored image, picture resolution is lost due to difficulties in interpolation between non-adjacent, same color pixels. The resulting unsharp images create the need to find a new way to obtain these images without requiring interpolation between adjacent pixels. An innovative method to capture images with individual pixel cells consisting of three layers of photodetectors stacked vertically upon one another has been created to rectify this problem, but no …
Implementation Of Real-Time Calibration Of Polarization Imaging Sensors, Collin Foster
Implementation Of Real-Time Calibration Of Polarization Imaging Sensors, Collin Foster
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Recent breakthroughs in nanofabrication techniques have led to development of sophisticated Division-of-Focal-Plane (DoFP) polarization imaging sensors. One such technique allows the fabrication of nanowire filters fabricated directly on the imaging sensor itself. This technique can be used to fabricate robust DoFP polarization imaging sensors. However, the polarization information captured by the imagers can be degraded due to imperfections in the fabrication of the nanowire filters on the imaging sensor. Polarization information can also be degraded from other sources including crosstalk between pixels. To compensate for these undesired effects, a calibration routine can be applied to each pixel after image capture. …
Youpon, Garrison Prinslow
Youpon, Garrison Prinslow
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This project was motivated by two related ideas: what can be learned about the unique issues involved with developing cloud-based mobile applications; and, what application could be developed to evaluate these characteristics that would also be innovative and provide value to users. After vetting ideas for the latter objective, it was clear that a new digital coupon system could offer value and apply interesting technologies to computer science problems, such as shortest path calculation, position-aware authentication, game theory, and statistical reasoning. A brief summary of the motivation for developing the new digital coupon system follows.
Delaunay-Restricted Optimal Triangulation Of 3d Polygons, Ming Zou, Tao Ju, Nathan Carr
Delaunay-Restricted Optimal Triangulation Of 3d Polygons, Ming Zou, Tao Ju, Nathan Carr
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Triangulation of 3D polygons is a well studied topic of research. Existing methods for finding triangulations that minimize given metrics (e.g., sum of triangle areas or dihedral angles) run in a costly O(n4) time [BS95,BDE96], while the triangulations are not guaranteed to be free of intersections. To address these limitations, we restrict our search to the space of triangles in the Delaunay tetrahedralization of the polygon. The restriction allows us to reduce the running time down to O(n2) in practice (O(n3) worst case) while guaranteeing that the solutions are intersection free. We demonstrate experimentally that the reduced search space is …
Real-Time Scheduling Of Parallel Tasks Under A General Dag Model, Abusayeed Saifullah, David Ferry, Chenyang Lu, Christopher Gill
Real-Time Scheduling Of Parallel Tasks Under A General Dag Model, Abusayeed Saifullah, David Ferry, Chenyang Lu, Christopher Gill
All Computer Science and Engineering Research
Due to their potential to deliver increased performance over single-core processors, multi-core processors have become mainstream in processor design. Computation-intensive real-time systems must exploit intra-task parallelism to take full advantage of multi-core processing. However, existing results in real-time scheduling of parallel tasks focus on restrictive task models such as the synchronous model where a task is a sequence of alternating parallel and sequential segments, and parallel segments have threads of execution that are of equal length. In this paper, we address a general model for deterministic parallel tasks, where a task is represented as a DAG with different nodes having …
Limitations And Solutions For Real-Time Local Inter-Domain Communication In Xen, Sisu Xi, Chong Li, Chenyang Lu, Christopher Gill
Limitations And Solutions For Real-Time Local Inter-Domain Communication In Xen, Sisu Xi, Chong Li, Chenyang Lu, Christopher Gill
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As computer hardware becomes increasingly powerful, there is an ongoing trend towards integrating complex, legacy real-time systems using fewer hosts through virtualization. Especially in embedded systems domains such as avionics and automotive engineering, this kind of system integration can greatly reduce system weight, cost, and power requirements. When systems are integrated in this manner, network communication may become local inter-domain communication (IDC) within the same host. This paper examines the limitations of inter-domain communication in Xen, a widely used open-source virtual machine monitor (VMM) that recently has been extended to support real-time domain scheduling. We find that both the VMM …
An Integrated Data Mining Approach To Real-Time Clinical Monitoring And Deterioration Warning, Yi Mao, Wenlin Chen, Yixin Chen, Chenyang Lu
An Integrated Data Mining Approach To Real-Time Clinical Monitoring And Deterioration Warning, Yi Mao, Wenlin Chen, Yixin Chen, Chenyang Lu
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Clinical study found that early detection and intervention are essential for preventing clinical deterioration in patients, for patients both in intensive care units (ICU) as well as in general wards but under real-time data sensing (RDS). In this paper, we develop an integrated data mining approach to give early deterioration warnings for patients under real-time monitoring in ICU and RDS. Existing work on mining real-time clinical data often focus on certain single vital sign and specific disease. In this paper, we consider an integrated data mining approach for general sudden deterioration warning. We synthesize a large feature set that includes …
Self-Stabilization In The Distributed Systems Of Finite State Machines, Abusayeed Saifullah
Self-Stabilization In The Distributed Systems Of Finite State Machines, Abusayeed Saifullah
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The notion of self-stabilization was first proposed by Dijkstra in 1974 in his classic paper. The paper defines a system as self-stabilizing if, starting at any, possibly illegitimate, state the system can automatically adjust itself to eventually converge to a legitimate state in finite amount of time and once in a legitimate state it will remain so unless it incurs a subsequent transient fault. Dijkstra limited his attention to a ring of finite-state machines and provided its solution for self-stabilization. In the years following his introduction, very few papers were published in this area. Once his proposal was recognized as …
Studying Network Optimization In The Context Of Self-Stabilization, Abusayeed Saifullah
Studying Network Optimization In The Context Of Self-Stabilization, Abusayeed Saifullah
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Self-stabilization is a theoretical framework of non-masking fault-tolerance for distributed networks. A self-stabilizing system is capable of tolerating any unexpected transient fault without outside intervention and, regardless of the initial state, it can converge to a legitimate global state, a predefined vector of local states, in finite time. Self-stabilization has rendered a good problem solving paradigm of networks over the last decade. In this paper, we survey the self-stabilizing solutions for various network optimization problems such as network flow, load balancing, load and resource distribution, routing, file distribution, shortest paths etc. The paper also summarizes some recent works presenting how …