Feature-based modeling is very popular in generating the shape and history of a product in a three-dimensional(3 D) CAD system. In the previous studies, features are the basic unit of the models. It o
ISBN:
(纸本)9781467389808
Feature-based modeling is very popular in generating the shape and history of a product in a three-dimensional(3 D) CAD system. In the previous studies, features are the basic unit of the models. It o
In statistical learning for real-world large-scale data problems, one must often resort to "streaming" algorithms which operate sequentially on small batches of data. In this work, we present an analysis of ...
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ISBN:
(纸本)9781538632666
In statistical learning for real-world large-scale data problems, one must often resort to "streaming" algorithms which operate sequentially on small batches of data. In this work, we present an analysis of the information-theoretic limits of mini-batch inference in the context of generalized linear models and low-rank matrix factorization. In a controlled Bayes-optimal setting, we characterize the optimal performance and phase transitions as a function of mini-batch size. We base part of our results on a detailed analysis of a mini-batch version of the approximate message-passing algorithm (Mini-AMP), which we introduce. Additionally, we show that this theoretical optimality carries over into real-data problems by illustrating that Mini-AMP is competitive with standard streaming algorithms for clustering.
Indirect measurements of physical parameters of interest often require a mathematical model in which these parameters are estimated accordingly to the gathered measurements. Within the Least Squares estimation, the pa...
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ISBN:
(纸本)9781509035960
Indirect measurements of physical parameters of interest often require a mathematical model in which these parameters are estimated accordingly to the gathered measurements. Within the Least Squares estimation, the parameters are estimated through a regression problem. The presence of dynamics, multiple sensors and high sampling rates lead to high dimensional regression matrices. This paper deals with solving such massive regression problems efficiently. We revisit Renaut's Least Squares Multisplitting (LSMS) technique aimed at solving the ordinary least squares problem in parallel. The LSMS decomposes the design matrix column-wise into several (possibly overlapping) blocks. The global least squares solution is subsequently replaced by an equivalent set of local least squares problems which are to be solved in parallel. At every iteration step the local solutions are recombined using an appropriate weighting scheme. This allows for a scalable and highly parallel implementation aimed at distributed systems. We study how to decompose the global estimation problem in smaller subproblems and quantify the effects of various possible partitions. The method is illustrated with dedicated numerical simulations and a toy application in the area of sensor fusion.
Valiant routing, the use of a random intermediate node to distribute network traffic, has been proposed for a number of recent HPC network topologies. It is also commonly used as a bulding block for adaptive routing a...
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ISBN:
(纸本)9781538610442
Valiant routing, the use of a random intermediate node to distribute network traffic, has been proposed for a number of recent HPC network topologies. It is also commonly used as a bulding block for adaptive routing algorithms, which use shortest path routes when possible, but revert to Valiant routing when necessary to avoid hot spots. We show that the version of Valiant routing proposed for the Slim fly topology can cause messages to follow loops, using an edge in both directions before returning to edges of the original shortest path. Removing these loops in the UGAL-L adaptive routing algorithm is shown to provide slight improvements in average latency and also allow the network to carry up to 12% more traffic before saturation.
Resource constrained project scheduling problem (RCPSP) is one of the classical problems in the area of discrete optimization. In this paper we propose an algorithm for solving RCPSP which relies on an adaptive insert...
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ISBN:
(纸本)9781509046010
Resource constrained project scheduling problem (RCPSP) is one of the classical problems in the area of discrete optimization. In this paper we propose an algorithm for solving RCPSP which relies on an adaptive insertion mutation operator that targets different regions of the search space. Neighbourhoods are exploited via forward-backward iterative local search. Furthermore, the algorithm makes use of an archive to ensure better utilization of the schedule budget. The performance of the approach is analysed across various problem complexities associated with J30, J60 and J120 full instance sets of PSPLib with budgets of 1,000, 5,000 and 50,000 schedules. The study provides insights on the performance of the algorithm i.e. why the performance is good for particular instances and not as good for others.
This paper discusses about the trajectory planning and controlled maneuvering of the vehicle in parking assist mode. The objective of the proposed algorithm is to use low-cost hardware like ultrasonic sensor in order ...
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ISBN:
(纸本)9781509060641
This paper discusses about the trajectory planning and controlled maneuvering of the vehicle in parking assist mode. The objective of the proposed algorithm is to use low-cost hardware like ultrasonic sensor in order to provide automated parking assist to the vehicle. The concept of grid occupancy is formulated in free space detection algorithm to compute lateral-longitudinal grid cell vacancy. The vehicle will enable automated parking assist mode for controlled maneuvering on completion of free space detection followed by path planning. The reference planned path is an optimized trajectory with single maneuver for the vehicle to traverse in a free parking space. The localized trajectory and control algorithm of the perpendicular parking have been designed with reference to perception sensor input. The controller facilitates the intelligent navigation of vehicle based on measured obstacle free clearance distance and reference point. The steering control algorithm based on fuzzy logic is designed to provide an optimized maneuvering of the host vehicle in perpendicular parking space. In order to ease parking effort, an innovative approach of combined feedback and feed-forward based fuzzy controller has been illustrated. The controller performance has been evaluated in simulation environment keeping vehicle dynamics model in loop. The test scenario has been modeled in Carmaker to substantiate the optimization of route selection and a smooth transition of vehicle in parking assist mode during maneuvering into an empty parking space.
In this article, we propose a data analytics development to detect unusual patterns of flights from a vast amounts of FDR (flight data recorder) data for supporting airline maintenance operations. A fundamental ration...
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ISBN:
(纸本)9781509060641
In this article, we propose a data analytics development to detect unusual patterns of flights from a vast amounts of FDR (flight data recorder) data for supporting airline maintenance operations. A fundamental rationale behind this development is that if there are potential issues on mechanical parts of an aircraft during a flight, evidences for these issues are most likely included in the FDR data. Therefore, the data analysis of FDR data enables us to detect the potential issues in the aircraft before they occur. To this end, in a data pre-processing step, a data filtering, a data sampling, and a data transformation are sequentially performed. And then, in this analysis, all time series data in the FDR are classified into three types: a continuous signal, a discrete signal, and a warning signal. For each type of signal, a high-dimensional vector by arranging the time series data is chosen as features. In the feature section process, a correlation analysis, a correlation relaxation, and a dimension reduction are sequentially conducted. Finally, a type of k-nearest neighbor approach is applied to automatically identify the FDR data in which the unusual flight patterns are recorded from a large amount of FDR data. The proposed method is tested with using a realistic FDR data from the NASA's open database.
With the rapid technology development of systems that assist drivers, the lack of uniform support for efficient algorithm development has emerged. We propose a universal Software Development Kit (SDK) concept with com...
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ISBN:
(纸本)9781509055449
With the rapid technology development of systems that assist drivers, the lack of uniform support for efficient algorithm development has emerged. We propose a universal Software Development Kit (SDK) concept with common optimization routines that can be applied to typical Advanced Driver Assistance Systems (ADAS) algorithms. The evaluation confirmed that the SDK decreased execution time for ADAS algorithms and works seamlessly across different embedded architectures.
Iterative stencil algorithms find applications in a wide range of domains. FPGAs have long been adopted for computation acceleration due to its advantages of dedicated hardware design. Hence, FPGAs are a compelling al...
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ISBN:
(纸本)9781450349277
Iterative stencil algorithms find applications in a wide range of domains. FPGAs have long been adopted for computation acceleration due to its advantages of dedicated hardware design. Hence, FPGAs are a compelling alternative for executing iterative stencil algorithms. However, efficient implementation of iterative stencil algorithms on FPGAs is very challenging due to the data dependencies between iterations and elements in the stencil algorithms, programming hurdle of FPGAs, and large design space. In this paper, we present a comprehensive framework that synthesizes iterative stencil algorithms on FPGAs efficiently. We leverage the OpenCL-to-FPGA toolchain to generate accelerator automatically and perform design space exploration at the high level. We propose to bridge the neighboring tiles through pipe and enable data sharing among them to improve computation efficiency. Then, we extend the equal tile size design to a heterogeneous design with different tile size to balance the computation among different tiles. We also develop analytical performance models to explore the complex design space. Experiments using a wide range of stencil applications demonstrate that on average our heterogeneous implementations achieve 1.65X performance speedup but with less hardware resource compared to the state-of-the-art.
This paper presents a reactive collision avoidance algorithm, which avoids both static and moving obstacles by keeping a constant avoidance angle between the vehicle velocity vector and the obstacle. In particular, we...
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ISBN:
(纸本)9781509028733
This paper presents a reactive collision avoidance algorithm, which avoids both static and moving obstacles by keeping a constant avoidance angle between the vehicle velocity vector and the obstacle. In particular, we consider marine vehicles with underactuated sway dynamics, which cannot be directly controlled. This gives an underactuated component in the vehicle velocity, which the proposed algorithm is designed to compensate for. The algorithm furthermore compensates for the obstacle velocity. Conditions are derived under which the sway movement is bounded and collision avoidance is mathematically proved. The theoretical results are supported by simulations. The proposed algorithm makes only limited sensing requirements on the vehicle, is intuitive and suitable for a wide range of vehicles. This includes vehicles with heavy forward acceleration constraints, which is demonstrated by applying the algorithm to a vehicle with constant surge speed.
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