共查询到20条相似文献,搜索用时 250 毫秒
1.
In this paper, we present an Inverse Multi-Objective Robust Evolutionary (IMORE) design methodology that handles the presence
of uncertainty without making assumptions about the uncertainty structure. We model the clustering of uncertain events in
families of nested sets using a multi-level optimization search. To reduce the high computational costs of the proposed methodology
we proposed schemes for (1) adapting the step-size in estimating the uncertainty, and (2) trimming down the number of calls
to the objective function in the nested search. Both offline and online adaptation strategies are considered in conjunction
with the IMORE design algorithm. Design of Experiments (DOE) approaches further reduce the number of objective function calls
in the online adaptive IMORE algorithm. Empirical studies conducted on a series of test functions having diverse complexities
show that the proposed algorithms converge to a set of Pareto-optimal design solutions with non-dominated nominal and robustness
performances efficiently.
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2.
New Particle Swarm Optimization (PSO) methods for dynamic and noisy function optimization are studied in this paper. The new
methods are based on the hierarchical PSO (H-PSO) and a new type of H-PSO algorithm, called Partitioned Hierarchical PSO (PH-PSO).
PH-PSO maintains a hierarchy of particles that is partitioned into several sub-swarms for a limited number of generations
after a change of the environment occurred. Different methods for determining the best time when to rejoin the sub-swarms
and how to handle the topmost sub-swarm are discussed. A standard method for metaheuristics to cope with noise is to use function
re-evaluations. To reduce the number of necessary re-evaluations a new method is proposed here which uses the hierarchy to
find a subset of particles for which re-evaluations are particularly important. In addition, a new method to detect changes
of the optimization function in the presence of noise is presented. It differs from conventional detection methods because
it does not require additional function evaluations. Instead it relies on observations of changes that occur within the swarm
hierarchy. The new algorithms are compared experimentally on different dynamic and noisy benchmark functions with a variant
of standard PSO and H-PSO that are both provided with a change detection and response method.
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3.
The paper presents a decision algorithmic model called vector gravitational force model in the feature space. The algorithmic
model, inspired by and similar to the Law of Universal Gravitation, is derived from the vector geometric analysis of the linear
classifier and established in the feature space. Based on this algorithmic model, we propose a classification method called
vector gravitational recognition. The proposed method is applied to the benchmark Glass Identification task in the UCI Database
available from USA Forensic Science Service, and other two UCI benchmark tasks. The experimental and comparative results show
that the proposed approach yields quite good results and outperforms some well known and recent approaches on the tasks, and
other applications may benefit from ours.
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4.
Ant colony optimization (ACO) is an optimization technique that was inspired by the foraging behaviour of real ant colonies.
Originally, the method was introduced for the application to discrete optimization problems. Recently we proposed a first
ACO variant for continuous optimization. In this work we choose the training of feed-forward neural networks for pattern classification
as a test case for this algorithm. In addition, we propose hybrid algorithm variants that incorporate short runs of classical
gradient techniques such as backpropagation. For evaluating our algorithms we apply them to classification problems from the
medical field, and compare the results to some basic algorithms from the literature. The results show, first, that the best
of our algorithms are comparable to gradient-based algorithms for neural network training, and second, that our algorithms
compare favorably with a basic genetic algorithm.
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5.
The paper reflects on the unique experience of social and technological development in Lithuania since the regaining of independence
as a newly reshaped society constructing a distinctive competitive IST-based model at global level. This has presented Lithuanian
pattern of how to integrate different experiences and relations between generations in implementing complex information society
approaches. The resulting programme in general is linked to the Lisbon objectives of the European Union. The experience of
transitional countries in Europe, each different but facing some common problems, may be useful to developing countries in
Africa.
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6.
A bewildering number of proposals have offered solutions to the privacy problems inherent in RFID communication. This article
tries to give an overview of the currently discussed approaches and their attributes.
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7.
One of the important tasks in Mechanical Engineering is to increase the safety of the vehicle and decrease its production
costs. This task is typically solved by means of Multiobjective Optimization, which formulates the problem as a mapping from
the space of design variables to the space of target criteria and tries to find an optimal region in these multidimensional
spaces. Due to high computational costs of numerical simulations, the sampling of this mapping is usually very sparse and
scattered. Combining design of experiments methods, metamodeling, new interpolation schemes and innovative graphics methods,
we enable the user to interact with simulation parameters, optimization criteria, and come to a new interpolated crash result
within seconds. We denote this approach as Simulated Reality, a new concept for the interplay between simulation, optimization
and interactive visualization. In this paper we show the application of Simulated Reality for solution of real life car design
optimization problems.
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8.
The nonserial polyadic dynamic programming algorithm is one of the most fundamental algorithms for solving discrete optimization
problems. Although the loops in the nonserial polyadic dynamic programming algorithm are similar to those in matrix multiplication,
the available automatic optimization techniques have little effect on this imperfect loop because of nonuniform data dependencies.
In this paper, we develop algorithmic optimizations to improve the cache performance of the nonserial polyadic dynamic programming
algorithm. Our algorithmic transformation takes advantage of the cache oblivious method by relaxing some dependencies in the
standard iterative version. Based on the ideal cache model of the cache oblivious algorithm, the approximate bound of cache
misses is given by
. We also found that the optimized algorithm with the cache oblivious approach is more sensitive to conventional optimization
techniques such as tiling. Experimental results on several platforms show that the optimized algorithms improve the cache
performance and achieves speedups of 2–10 times.
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9.
This paper describes the simulated car racing competition that was arranged as part of the 2007 IEEE Congress on Evolutionary
Computation. Both the game that was used as the domain for the competition, the controllers submitted as entries to the competition
and its results are presented. With this paper, we hope to provide some insight into the efficacy of various computational
intelligence methods on a well-defined game task, as well as an example of one way of running a competition. In the process,
we provide a set of reference results for those who wish to use the simplerace game to benchmark their own algorithms. The paper is co-authored by the organizers and participants of the competition.
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10.
Scheduling for the flexible job shop is very important in both fields of production management and combinatorial optimization.
In this work, a double layer Ant Colony Optimization (ACO) algorithm is proposed for the Flexible Job Shop Scheduling Problem
(FJSSP). In the proposed algorithm, two different ACO algorithms are applied to solve the FJSSP with a hierarchical way. The
primary mission of upper layer ACO algorithm is achieving an excellent assignment of operations to machines. The leading task
of lower layer ACO algorithm is obtaining the optimal sequencing of operations on each machine. Experimental results suggest
that the proposed algorithm is a feasible and effective approach for the multi-objective FJSSP.
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11.
Quantitative usability requirements are a critical but challenging, and hence an often neglected aspect of a usability engineering process. A case study is described where quantitative usability requirements played a key role in the development of a new user interface of a mobile phone. Within the practical constraints of the project, existing methods for determining usability requirements and evaluating the extent to which these are met, could not be applied as such, therefore tailored methods had to be developed. These methods and their applications are discussed. 相似文献
12.
Listening to music on personal, digital devices whilst mobile is an enjoyable, everyday activity. We explore a scheme for
exploiting this practice to immerse listeners in navigation cues. Our prototype, ONTRACK, continuously adapts audio, modifying
the spatial balance and volume to lead listeners to their target destination. First we report on an initial lab-based evaluation
that demonstrated the approach’s efficacy: users were able to complete tasks within a reasonable time and their subjective
feedback was positive. Encouraged by these results we constructed a handheld prototype. Here, we discuss this implementation
and the results of field-trials. These indicate that even with a low-fidelity realisation of the concept, users can quite
effectively navigate complicated routes.
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13.
The complexity of group dynamics occurring in small group interactions often hinders the performance of teams. The availability
of rich multimodal information about what is going on during the meeting makes it possible to explore the possibility of providing
support to dysfunctional teams from facilitation to training sessions addressing both the individuals and the group as a whole.
A necessary step in this direction is that of capturing and understanding group dynamics. In this paper, we discuss a particular
scenario, in which meeting participants receive multimedia feedback on their relational behaviour, as a first step towards
increasing self-awareness. We describe the background and the motivation for a coding scheme for annotating meeting recordings
partially inspired by the Bales’ Interaction Process Analysis. This coding scheme was aimed at identifying suitable observable
behavioural sequences. The study is complemented with an experimental investigation on the acceptability of such a service.
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14.
The article draws on a decade of work in the UK by the UK Work Organisation Network (UKWON), and recommends a systematic approach.
Taking cases in the National Health Service, the focus is on employee involvement, partnership and the development of social
capital. High and low road approaches are compared, in an evaluation of the Improving Working Lives programme.
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15.
In this paper the authors, starting from the experience described and commented on in earlier work by Mancini and Sbordone, deal with the three main epistemological problems that the research group they participated in had to face: |
The conflicting and ambiguous relationship between psychoanalysis and social research
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The classical epistemological problem of the relationship between the subject and object of research within the perspective of action research
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The problem arising from their experience, i.e., the risk of manipulation, and the way to deal with it from an epistemic perspective
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The three problems are dealt with one at a time, but from a common perspective, i.e., the attempt to integrate the richness and variety of human subjectivity in social research. As to the relationship between psychoanalysis and social research, a special section is devoted to the implications of an integrated or convergent methodology on team-working in organisations. 相似文献
16.
Network calculus offers powerful tools to analyze the performances in communication networks, in particular to obtain deterministic
bounds. This theory is based on a strong mathematical ground, notably by the use of (min,+) algebra. However, the algorithmic
aspects of this theory have not been much addressed yet. This paper is an attempt to provide some efficient algorithms implementing
network calculus operations for some classical functions. Some functions which are often used are the piecewise affine functions
which ultimately have a constant growth. As a first step towards algorithmic design, we present a class containing these functions
and closed under the main network calculus operations (min, max, +, −, convolution, subadditive closure, deconvolution): the
piecewise affine functions which are ultimately pseudo-periodic. They can be finitely described, which enables us to propose
some algorithms for each of the network calculus operations. We finally analyze their computational complexity.
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17.
The Stanford Event Heap has been shown to provide appropriate support for constructing interactive workspace applications.
Given this success it is natural to consider the Event Heap as a platform to support other classes of Ubiquitous Computing
applications. In this paper we argue that the distributed, spontaneous nature of these applications places additional demands
on the Event Heap that require extensions to both the engineering and API. Suitable extensions are described and their use
to support a typical Ubicomp application is discussed.
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18.
We present a study of using camera-phones and visual-tags to access mobile services. Firstly, a user-experience study is described in which participants were both observed learning to interact with a prototype mobile service and interviewed
about their experiences. Secondly, a pointing-device task is presented in which quantitative data was gathered regarding the speed and accuracy with which participants aimed and clicked
on visual-tags using camera-phones. We found that participants’ attitudes to visual-tag-based applications were broadly positive,
although they had several important reservations about camera-phone technology more generally. Data from our pointing-device
task demonstrated that novice users were able to aim and click on visual-tags quickly (well under 3 s per pointing-device
trial on average) and accurately (almost all meeting our defined speed/accuracy tradeoff of 6% error-rate). Based on our findings,
design lessons for camera-phone and visual-tag applications are presented.
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19.
There are only a few ethical regulations that deal explicitly with robots, in contrast to a vast number of regulations, which
may be applied. We will focus on ethical issues with regard to “responsibility and autonomous robots”, “machines as a replacement
for humans”, and “tele-presence”. Furthermore we will examine examples from special fields of application (medicine and healthcare,
armed forces, and entertainment). We do not claim to present a complete list of ethical issue nor of regulations in the field
of robotics, but we will demonstrate that there are legal challenges with regard to these issues.
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