The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, we propose a new segmentation algorithm that combines a graph-based shape model with image cues based on boosted features. The landmark-based shape model encodes prior constraints through the normalized Euclidean distances between pairs of control points, alleviating the need of a large database for the training. Moreover, the graph topology is deduced from the dataset using manifold...
Recent work has shown that resonate-and-fire model is both computationally efficient and suitable for large network simulations. In this paper, we examine the estimation problem of a resonate-and-fire model with random threshold. The model parameters are divided into two sets. The first set is associated with subthreshold behavior and can be optimized by a nonlinear least squares algorithm. The other...
Branch and Bound (B&B) algorithms are highly parallelizable but they are irregular and dynamic load balancing techniques have been used to avoid idle processors. In previous work, authors use a dynamic number of threads at run time, which depends on the measured performance of the application for just one interval B&B algorithm running on the system. In this way, load balancing is achieved...
Quantitative in silico modeling is a powerful means to enhance our understanding of complex biological systems. Accordingly, intuitive and flexible computational tools are needed to support the development of such models. We previously developed the platform EPISIM for graphical modeling and simulation of cellular behavior in epithelia. In this work we demonstrate how computationally efficient software...
We propose a cross-layer based multi-channel Medium Access Control (MAC) protocol to maximize the utilization of the leftover spectrum of primary user channels in cognitive radio networks. This protocol integrates the spectrum sensing at Physical layer and the packet scheduling at the MAC layer for mobile ad-hoc networks. With a TDMA-based control channel, we have a scheme to handle collision. Moreover,...
In this paper, the design and optimization of a nonlinear taper, connecting the output section of a gyrotron cavity to the uniform waveguide section, is presented. Non linear Tapers for 170 GHz and 140 GHz gyrotrons operating in TE31,11 and TE28,12 modes are taken as a case study. Such gyrotrons find applications in thermonuclear fusion experiments. Hybrid Space Mapping techniques are used for design...
Parallelisation, serial optimisation, compiler tuning, and many more techniques are used to optimise and improve the performance scaling of parallel programs. One area which is frequently not optimised is file I/O. This is because it is often not considered to be key to the performance of a program and also because it is traditionally difficult to optimise and very machine specific. However, in the...
We have previously documented the on-going work in the EUFORIA project to parallelise and optimise European fusion simulation codes, see. This involves working with a wide range of codes to try and address any performance and scaling issues that these codes have. However, as no two simulation codes are exactly the same, it is very hard to apply exactly the same approach to optimising a disparate range...
FlexRay is a popular communication protocol in modern automotive systems with several computation nodes and communication units. The complex temporal behavior of such systems depends highly on the FlexRay configuration and influences the performance of running control applications. In our previous work, we presented a design framework for integrated scheduling and design of embedded control applications,...
The identification algorithm of correlation analysis is understood easily. But the calculation amount is very large. The optimizing space was selected appropriately. Then the Fibonacci sequence was introduced into the algorithm. Variable step based on modified Fibonacci sequence was used to optimize the model parameters. The result of simulation indicates that the calculation amount is decreased and...
Generation capacity expansion models have a long tradition in the power industry. Designed as optimization problems for the regulated monopoly industry, they can be interpreted as equilibrium models in a competitive environment. While often written as deterministic problems, they can be adapted to accommodate the wide range of uncertainties that currently assail the industry. We consider a stochastic...
Fracturing sand control is a complex sand prevention method. There are so many influence factors which can not be modeled by the structuring models in both the decision and the operation process. Expert system for the optimization design of the fracturing sand control can simulate the thinking patterns of those experts, collect the computer knowledge and models in the field, apply the fuzzy mathematics...
Several scenarios exist in the modern inter- connected world which call for an efficient network interdiction algorithm. Applications are varied, including various monitoring and load shedding applications on large smart energy grids, computer network security, preventing the spread of Internet worms ad malware, policing international smuggling networks, and controlling the spread of diseases. In...
Volume of sealed radio-electronic device with surface mount is optimized. Thermal processes are simulated in computer-aided engineering systems. Ellipsoidal model of boundaries of operability domain is used. The nonlinear properties of heat transfer processes are taking into account.
The criteria of finding the optimal structure of the model as interval difference operator is carried out. It is shown that the formulated task of structure identification is a multicriteria optimization task with the discrete target functions and nonlinear constraints specified by interval system of nonlinear algebraic equations (ISNAE).
A simulation-driven optimization framework for computationally efficient design of ultrawideband (UWB) antennas is presented. Our approach exploits coarsely-discretized electromagnetic (EM) simulations as a low-fidelity model of the antenna under consideration. This low-fidelity model is used as a prediction tool to find an approximate optimum design. The discrepancy between the low- and the high-fidelity...
Full-wave optimisation of large arrays is computationally intensive problem even with the most advanced solvers. The paper presents a procedure for the full-wave optimisation of arrays based on a space mapping (SM) procedure. The approach combines the efficiency of MoM-based accelerated modelling techniques with physics-based coarse models to reach unprecedented efficiency in terms of accuracy and...
The need for compilers of embedded systems to find effective ways of optimizing series of loop-nests is urgent. This is especially so for streaming applications such as M-Jpeg, H.264 etc. which are popular in embedded systems. The loop bounds and memory references of these applications are primarily affine functions of the outer loop counters and constant parameters. The polyhedral model provides...
Many high-end computing systems use an extremely large number of power-hungry commercial components to achieve high performance. Power reduction and energy conservation are important in these systems for the reason of minimizing operating cost. Two main mechanisms are commonly applied to power reduction in these systems: Dynamic Voltage/ Frequency Scaling (DV/FS) and server number controlling: Vary-On...
Robots that operate in natural human environments must be capable of handling uncertain dynamics and underspecified goals. Current solutions for robot motion planning are split between graph-search methods, such as RRT and PRM which offer solutions to high-dimensional problems, and Reinforcement Learning methods, which relieve the need to specify explicit goals and action dynamics. This paper addresses...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.