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Full-Text Articles in Computer Engineering
Split And Merge Functions For Supporting Multiple Processing Pipelines In Mercury Blastn, Jwalant Ahir, Jeremy Buhler, Roger D. Chamberlain
Split And Merge Functions For Supporting Multiple Processing Pipelines In Mercury Blastn, Jwalant Ahir, Jeremy Buhler, Roger D. Chamberlain
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Biosequence similarity search is an important application in computational biology. Mercury BLASTN, an FPGA-based implementation of BLAST for DNA, is one of the alternatives for fast DNA sequence comparison. The re-design of BLAST into a streaming application combined with a high-throughput hardware pipeline have enabled Mercury BLAST to emerge as one of the fastest implementations of bio-sequence similarity search. This performance can be further enhanced by exploiting the data-level parallelism present within the application. Here we present a multiple FPGA-based Mercury BLASTN design in order to double the speed and throughput of DNA sequence computation. This paper describes a dual …
Cloud Computing For Scalable Planning By Stochastic Search, Qiang Lu, You Xu, Ruoyun Huang, Yixin Chen
Cloud Computing For Scalable Planning By Stochastic Search, Qiang Lu, You Xu, Ruoyun Huang, Yixin Chen
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Graph search has been employed by many AI techniques and applications. A natural way to improve the efficiency of search is to utilize ad- vanced, more powerful computing platforms. However, expensive computing infrastructures, such as supercomputers and large-scale clusters, are traditionally available to only a limited number of projects and researchers. As a results, most AI applications, with access to only commodity com- puters and clusters, cannot benefit from the efficiency improvements of high-performance parallel search algorithms. Cloud computing provides an attractive, highly accessible alternative to other traditional high- performance computing platforms. In this paper, we first show that the …
Against All Probabilities: A Modeling Paradigm For Streaming Applications That Goes Against Common Notions, Rahav Dor
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Hardware and software design requires the right portion of skills and mental faculties. The design of a good system is an exercise in rational thinking, engineering, and art. The design process is further complicated when we aspire to build systems that exploit parallelism or are targeted to be deployed on architecturally diverse computing devices, FPGAs or GPUs to name just a few. The need to develop systems that can take advantage of computing devices beyond general purpose CPUs is real. There are several application domains and research efforts that will simply not be able to adequately perform or yield answers …
Multi-Tier Diversified Service Architecture For Internet 3.0: The Next Generation Internet, Subharthi Paul, Raj Jain, Jianli Pan, Chakchai So-In
Multi-Tier Diversified Service Architecture For Internet 3.0: The Next Generation Internet, Subharthi Paul, Raj Jain, Jianli Pan, Chakchai So-In
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The next generation Internet needs to support multiple diverse application contexts. In this paper, we present Internet 3.0, a diversified, multi-tier architecture for the next generation Internet. Unlike the current Internet, Internet 3.0 defines a new set of primitives that allows diverse applications to compose and optimize their specific contexts over resources belonging to multiple ownerships. The key design philosophy is to enable diversity through explicit representation, negotiation and enforcement of policies at the granularity of network infrastructure, compute resources, data and users. The basis of the Internet 3.0 architecture is a generalized three-tier object model. The bottom tier consists …
Arch: Practical Channel Hopping For Reliable Home-Area Sensor Networks, Mo Sha, Gregory Hackmann, Chenyang Lu
Arch: Practical Channel Hopping For Reliable Home-Area Sensor Networks, Mo Sha, Gregory Hackmann, Chenyang Lu
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Home area networks (HANs) promise to enable sophisticated home automation applications such as smart energy usage and assisted living. However, recent empirical study of HAN reliability in real-world residential environments revealed significant challenges to achieving reliable performance in the face of significant and variable interference from a multitude of coexisting wireless devices. We propose the Adaptive and Robust Channel Hopping (ARCH) protocol: a lightweight receiveroriented protocol which handles the dynamics of residential environments by reactively channel hopping when channel conditions have degraded. ARCH has several key features. First, ARCH is an adaptive protocol that channel-hops based on changes in channel …
End-To-End Delay Analysis For Fixed Priority Scheduling In Wirelesshart Networks, Abusayeed Saifullah, You Xu, Chenyang Lu, Yixin Chen
End-To-End Delay Analysis For Fixed Priority Scheduling In Wirelesshart Networks, Abusayeed Saifullah, You Xu, Chenyang Lu, Yixin Chen
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The WirelessHART standard has been specifically designed for real-time communication between sensor and actuator devices for industrial process monitoring and control. End-to-end communication delay analysis for WirelessHART networks is required for acceptance test of real-time data flows from sensors to actuators and for workload adjustment in response to network dynamics. In this paper, we map the scheduling of real-time periodic data flows in a WirelessHART network to real-time multiprocessor scheduling. We, then, exploit the response time analysis for multiprocessor scheduling and propose a novel method for the end-to-end delay analysis of the real-time flows that are scheduled using a fixed …
Toward A Two-Tier Clinical Warning System For Hospitalized Patients, Gregory Hackmann, Minmin Chen, Octav Chipara, Chenyang Lu, Yixin Chen, Marin Kollef, Thomas C. Bailey
Toward A Two-Tier Clinical Warning System For Hospitalized Patients, Gregory Hackmann, Minmin Chen, Octav Chipara, Chenyang Lu, Yixin Chen, Marin Kollef, Thomas C. Bailey
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Clinical study has found early detection and intervention to be essential for preventing clinical deterioration in patients at general hospital units. In this paper, we envision a two-tiered early warning system designed to identify the signs of clinical deterioration and provide early warning of serious clinical events. The first tier of the system automatically identifies patients at risk of clinical deterioration from existing electronic medical record databases. The second tier performs real-time clinical event detection based on real-time vital sign data collected from on-body wireless sensors attached to those high-risk patients. We employ machine-learning techniques to analyze data from both …
A Scalable Method For Solving High-Dimensional Continuous Pomdps Using Local Approximation, Tom Erez, William D. Smart
A Scalable Method For Solving High-Dimensional Continuous Pomdps Using Local Approximation, Tom Erez, William D. Smart
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Partially-Observable Markov Decision Processes (POMDPs) are typically solved by finding an approximate global solution to a corresponding belief-MDP. In this paper, we offer a new planning algorithm for POMDPs with continuous state, action and observation spaces. Since such domains have an inherent notion of locality, we can find an approximate solution using local optimization methods. We parameterize the belief distribution as a Gaussian mixture, and use the Extended Kalman Filter (EKF) to approximate the belief update. Since the EKF is a first-order filter, we can marginalize over the observations analytically. By using feedback control and state estimation during policy execution, …
Global Constructive Optimization Of Vascular Systems, Manfred Georg, Tobias Preusser, Horst K. Hahn
Global Constructive Optimization Of Vascular Systems, Manfred Georg, Tobias Preusser, Horst K. Hahn
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We present a framework for the construction of vascular systems based on optimality principles of theoretical physiology. Given the position and flow distribution of end points of a vascular system, we construct the topology and positions of internal nodes to complete the vascular system in a realistic manner. Optimization is driven by intravascular volume minimization with constraints derived from physiological principles. Direct optimization of a vascular system, including topological changes, is used instead of simulating vessel growth. A good initial topology is found by extracting key information from a previously optimized model with less detail. This technique is used iteratively …
Optimal Time Utility Based Scheduling Policy Design For Cyber-Physical Systems , Terry Tidwell, Robert Glaubius, Christopher D. Gill, William D. Smart
Optimal Time Utility Based Scheduling Policy Design For Cyber-Physical Systems , Terry Tidwell, Robert Glaubius, Christopher D. Gill, William D. Smart
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Classical scheduling abstractions such as deadlines and priorities do not readily capture the complex timing semantics found in many real-time cyber-physical systems. Time utility functions provide a necessarily richer description of timing semantics, but designing utility-aware scheduling policies using them is an open research problem. In particular, optimal utility accrual scheduling design is needed for real-time cyber-physical domains. In this paper we design optimal utility accrual scheduling policies for cyber-physical systems with periodic, non-preemptable tasks that run with stochastic duration. These policies are derived by solving a Markov Decision Process formulation of the scheduling problem. We use this formulation to …
What Do Collaborations With The Arts Have To Say About Human-Robot Interaction?, William D. Smart, Annamaria Pileggi, Leila Takayama
What Do Collaborations With The Arts Have To Say About Human-Robot Interaction?, William D. Smart, Annamaria Pileggi, Leila Takayama
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This is a collection of papers presented at the workshop "What Do Collaborations with the Arts Have to Say About HRI", held at the 2010 Human-Robot Interaction Conference, in Osaka, Japan.
Sorting As A Streaming Application Executing On Chip Multiprocessors, Roger D. Chamberlain, Greg A. Galloway, Mark A. Franklin
Sorting As A Streaming Application Executing On Chip Multiprocessors, Roger D. Chamberlain, Greg A. Galloway, Mark A. Franklin
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Expressing concurrency in applications has always been a difficult and error-prone endeavor, yet effective utilization of multi-core processors requires that the concurrency in applications be understood. One approach to the expression of concurrency is streaming, which has shown real promise as a safe and effective method for many application classes. Here, we express a classic problem, sorting, in the streaming paradigm and explore the implications of various algorithm and architectural design parameters on the performance of the application.
The Design And Implementation Of Mcflow: A Real-Time Multi-Core Aware Middleware For Dependent Task Graphs, Huang-Ming Huang, Christopher Gill, Chenyang Lu
The Design And Implementation Of Mcflow: A Real-Time Multi-Core Aware Middleware For Dependent Task Graphs, Huang-Ming Huang, Christopher Gill, Chenyang Lu
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Modern computer architectures have evolved from uni-processor platforms to multi-processor and multi-core plat- forms, but traditional real-time distributed middleware such as RT-CORBA has not kept pace with that evolution. To address those issues, this paper describes the design and implementation of MCFlow, a new real-time distributed middleware for dependent task graphs running on multi-core platforms. MCFlow provides the following contributions to the state of the art in real-time middleware: (1) it provides an efficient C++ based component model through which computations can be configured flexibly for execution within a single core, across cores of a common host, or spanning multiple …
Optimal Design-Space Exploration Of Streaming Applications, Shobana Padmanabhan, Yixin Chen, Roger D. Chamberlain
Optimal Design-Space Exploration Of Streaming Applications, Shobana Padmanabhan, Yixin Chen, Roger D. Chamberlain
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Many embedded and scientific applications are frequently pipelined asynchronously and deployed on architecturally diverse systems to meet performance requirements and resource constraints. We call such pipelined applications streaming applications. Typically, there are several design parameters in the algorithms and architectures used that, when customized, impact the tradeoff between different metrics of application performance as well as resource utilization. Automatic exploration of this design space is the goal of this research. When using architecturally diverse systems to accelerate streaming applications, the design search space is often complex. We present a global optimization framework comprising a novel domain-specific variation of branch-and-bound that …
Performance Tuning Of Streaming Applications Via Search-Space Decomposition, Shobana Padmanabhan, Roger D. Chamberlain, Yixin Chen
Performance Tuning Of Streaming Applications Via Search-Space Decomposition, Shobana Padmanabhan, Roger D. Chamberlain, Yixin Chen
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High-performance streaming applications are typically pipelined and deployed on architecturally diverse (hybrid)systems. Developers of such applications are interested in customizing components used, so as to benefit application performance. We present an efficient and automatic technique for design-space exploration of applications in this problem domain. We solve performance tuning as an optimization problem by formulating cost functions using results from queueing theory. This results in a mixed-integer nonlinear optimization problem which is NP-hard. We reduce the search complexity by decomposing the search space. We have developed a domain-specific decomposition technique using topological information of the application embodied in the queueing network …
Multi-Channel Reliability And Spectrum Usage In Real Homes: Empirical Studies For Home-Area Sensor Networks, Mo Sha, Gregory Hackmann, Chenyang Lu
Multi-Channel Reliability And Spectrum Usage In Real Homes: Empirical Studies For Home-Area Sensor Networks, Mo Sha, Gregory Hackmann, Chenyang Lu
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Home area networks (HANs) consisting of wireless sensors have emerged as the enabling technology for important applications such as smart energy and assisted living. A key challenge faced by HANs is maintaining reliable operation in real-world residential environments. This paper presents two in-depth empirical studies on the wireless channels in real homes. The spectrum study analyzes the spectrum usage in the 2.4 GHz band where wireless sensor networks based on the IEEE 802.15.4 standard must coexist with existing wireless devices. We characterize the ambient wireless environment in six apartments through passive spectrum analysis across the entire 2.4 GHz band over …
Priority Assignment For Real-Time Flows In Wirelesshart Sensor-Actuator Networks, Abusayeed Saifullah, You Chenyang, Yixin Chen
Priority Assignment For Real-Time Flows In Wirelesshart Sensor-Actuator Networks, Abusayeed Saifullah, You Chenyang, Yixin Chen
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Recent years have witnessed the adoption of wireless sensor-actuator networks as a communication infrastructure for process control applications. An important enabling technology for industrial process control is WirelessHART, an open wireless sensor-actuator network standard specifically developed for process industries. A key challenge faced byWirelessHART networks is to meet the stringent real-time communication requirements imposed by feedback control systems in process industries. Fixed priority scheduling, a popular scheduling policy in real-time networks, has recently been shown to be an effective real-time transmission scheduling policy in WirelessHART networks. Priority assignment has a major impact on the schedulability of real-time flows in these …
An Inexpensive Robot Platform For Teleoperation And Experimentation, Daniel A. Lazewatsky, William D. Smart
An Inexpensive Robot Platform For Teleoperation And Experimentation, Daniel A. Lazewatsky, William D. Smart
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Most commercially-available robots are either aimed at the research community, or are designed with a single purpose in mind. The extensive hobbyist community has tended to focus on the hardware and the low-level software aspects. We claim that there is a need for a low-cost, general-purpose robot, accessible to the hobbyist community, with sufficient computation and sensing to run ``research-grade'' software. In this paper, we describe the design and implementation of such a robot. We explicitly outline our design goals, and show how a capable robot can be assembled from off-the-shelf parts, for a modest cost, by a single person …