A distributed network of sensors leverages its performance by aggregating information gathered by individual sensors through the process of sensor data fusion. Estimating parameters using a centralized scheme entails ...
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ISBN:
(纸本)9781509039005
A distributed network of sensors leverages its performance by aggregating information gathered by individual sensors through the process of sensor data fusion. Estimating parameters using a centralized scheme entails transporting data from multiple sensors to a centralized fusion center, leading to high network bandwidth consumption. Additionally, fusing raw sensor data from sensors with different sensing modalities may not be feasible. We propose an alternative approach in which each sensor first individually estimates the unknown parameters based solely on its own sensor data. Since sensors may not have a-priori knowledge of the probability distribution of the unknown parameters, each sensor independently computes its individual maximum likelihood estimates. Individual estimates along with their sufficient statistics are then communicated to the fusion center, which treats these estimates as observations to compute the optimum aggregated maximum likelihood estimates by maximizing the new likelihood function of these observations. The proposed technique offers two significant advantages: (i) Since each sensor computes its individual estimates based solely on its own sensed data, it is easily applicable to sensor networks having multi-modal sensors, and (ii) As compared to raw sensor data, communicating estimates and their sufficient statistics to the fusion center requires substantially less network bandwidth. Performance of the aggregated estimates is evaluated through simulations and by computing the Cramer-Rao lower bound.
作者：
McKenzie, Frederic D.Modeling
Simulation and Visualization Engineering Department Old Dominion University NorfolkVA United States
The Accreditation Board for engineering and Technology (ABET) is an internationally known organization for recognizing engineering programs that work towards student attainment in learning outcomes that conform to eng...
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ISBN:
(纸本)9788897999485
The Accreditation Board for engineering and Technology (ABET) is an internationally known organization for recognizing engineering programs that work towards student attainment in learning outcomes that conform to engineering disciplines and have a process for measuring attainment and continuous improvement. There are eight general criteria to be satisfied that include student outcomes, educational objectives, curriculum, facilities and faculty. Additionally, there may be program-specific requirements depending on the particular discipline. The modeling and simulation (M&S) engineering (M&SE) program at Old Dominion University satisfies the program criteria for general engineering in the ABET engineering Accreditation Commission and declares detailed discipline-specific student outcomes to ensure unambiguous definition of a pioneering program in order to set a standard that can be utilized as a template for future up-and-coming M&SE programs. This paper presents the curriculum and programspecific outcomes that have been incorporated into our continuous improvement process for student attainment of our M&S engineering program outcomes.
Co-designing applications and computer architectures has become of major importance due to the growing complexity of both applications and architectures and the need to better match application characteristics to the ...
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We review the state of the art of process modeling for discrete event simulation, make a number of observations and identify a number of issues that have to be tackled for promoting the use of process modeling in simu...
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ISBN:
(纸本)9781509044849
We review the state of the art of process modeling for discrete event simulation, make a number of observations and identify a number of issues that have to be tackled for promoting the use of process modeling in simulation. Process models are of particular interest in model-based simulationengineering approaches where the executable simulation model (code) is obtained with the help of textual or visual models. We present an illustrative example of model-based simulation development.
The first undergraduate degree program in modeling and simulationengineering recently was implemented at Old Dominion University. The program awards the Bachelor of Science Degree in modeling and simulation Engineeri...
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This paper describes on-going work on the transposition to digital format of 2D images of a printed atlas of the brainstem. In MRI-based anatomical modeling for neurosurgery planning and simulation, the complexity of ...
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Co-designing applications and computer architectures has become of major importance due to the growing complexity of both applications and architectures and the need to better match application characteristics to the ...
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ISBN:
(纸本)9781510801011
Co-designing applications and computer architectures has become of major importance due to the growing complexity of both applications and architectures and the need to better match application characteristics to the available hardware. Thus, "mini-applications", which serve as proxies of large-scale ones by highlighting their most intensive parts and major workflow components, appeared to the co-design, tuning, and adaptation purposes. This paper presents a work on optimizing the communication subsystem of a classical MD proxy (CoMD) application executed on multi-core computing clusters. The research focuses on hiding communication with certain buffer handling operations. In particular, two strategies are presented: one that uses two parallel threads for communication and buffer handling and another that introduces more parallelism by allowing all the available threads to unload the buffers while using two thread to communicate, thereby improving load balancing. The first proposed strategy yields performance gains up to 61% in the communication routines, corresponding to 6% gains in the overall time, while the second strategy achieves, respectively, about 73% and 6.3% improvement.
The classical, popular Hungarian algorithm for solving the “optimum assignment” problems (with its broad engineering/science applications) has been well-documented in the literature. Other (more efficient) variation...
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The classical, popular Hungarian algorithm for solving the “optimum assignment” problems (with its broad engineering/science applications) has been well-documented in the literature. Other (more efficient) variations of the Hungarian algorithm have also been extensively studied by the research communities. In this paper, the basic Hungarian algorithm is revisited, with the ultimate goal of developing a useful, user friendly, attractive Java computer animation for “effectively teaching” this basic/important optimum assignment algorithm. The final product from this work will help both the students and their instructor to not only mastering this technical subject, but also provide valuable tool for obtaining the solutions for homework assignments, class examinations, self-assessment tools, etc. A demo video of the Hungarian Algorithm's animation and result can be viewed online from any web browser using the website provided in reference [9].
In most of the traffic safety studies, both the identification of high-risk locations and the assessment of safety improvement solutions are done through the use of historical crash data. This study proposes an altern...
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ISBN:
(纸本)9781509018901
In most of the traffic safety studies, both the identification of high-risk locations and the assessment of safety improvement solutions are done through the use of historical crash data. This study proposes an alternative approach that makes use of traffic conflicts extracted from traffic video recordings for safety assessment. State-of-the-art computer vision techniques are used to extract vehicle trajectories automatically from 70 hours of traffic video data at two intersections. More specifically, a modified implementation of the Kanade-Lucas-Tomasi (KLT) feature tracker is used to extract the feature points and track those feature points frame by frame. The spectral embedding and the Dirichlet process Gaussian mixture model (DPGMM) are employed to cluster feature points that belong to the same object. The combination of each vehicle's individual trajectory with all the others' trajectories is then screened to identify all the possible vehicle pairs involved in conflict risk. Traffic conflict risks are identified after the time to collision (TTC) is computed for each vehicle pair. Hourly number of conflicts are found to follow a negative binomial distribution similar to number of crashes. A strong correlation is observed between the traffic conflicts and actual crashes, and thus the validity of using conflict data extracted from videos for safety assessment can be confirmed. The proposed approach has potential transferability and can be implemented by transportation agencies in other cities.
The first undergraduate degree program in modeling and simulationengineering recently was implemented at Old Dominion University. The program awards the Bachelor of Science Degree in modeling and simulation Engineeri...
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ISBN:
(纸本)9781467397414
The first undergraduate degree program in modeling and simulationengineering recently was implemented at Old Dominion University. The program awards the Bachelor of Science Degree in modeling and simulationengineering and was designed to meet the ABET accreditation requirements for general engineering programs. This paper describes the design and implementation of a continuous improvement process for the program. The department mission statement and the program educational objectives are presented. The student outcomes are stated and an assessment process for evaluating student achievement is described. Finally, the continuous improvement process for the program is presented. Recommendations from the initial ABET accreditation visit are summarized.
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