This paper describes a new approach in project portfolio selection (PPS) problems, emphasizing the need to overcome traditional deficiencies with respect to multicriteria decision-making and multiobjective optimizatio...
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This paper describes a new approach in project portfolio selection (PPS) problems, emphasizing the need to overcome traditional deficiencies with respect to multicriteria decision-making and multiobjective optimization. While existing methods typically allow the solving of partial aspects of the PPS problem, the proposed approach seeks to provide a holistic framework dealing with aspects like interdependence between projects, interaction among criteria, the incorporation of both cardinal and ordinal information, and a hierarchical multiobjective optimization. Unlike approaches that optimize portfolios neglecting superiority of some projects, or those that only assess individual projects without considering overall portfolio performance, the proposal allows for a compromise between both objectives. A case study is given, proving the application of the proposal for developing well-balanced portfolios aligned with strategic organizational goals and stakeholder preferences. The results point to significant improvements in the efficiency and effectiveness of decision-making, especially in complex project environments. This research contributes not only to the advancement of the theoretical framework of PPS but also to practical implications for portfolio management in a wide variety of organizational contexts.
QRS detection in exercise stress test recordings remains a challenging task, because they are highly non-stationary and contaminated with noises, such as large baseline wander and muscular noise, among others. The aim...
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ISBN:
(纸本)9781479943463
QRS detection in exercise stress test recordings remains a challenging task, because they are highly non-stationary and contaminated with noises, such as large baseline wander and muscular noise, among others. The aim of this work is to find an optimal set of parameters for QRS detection in very noisy ECG signals, such as those acquired during stress tests. Parameter optimization was addressed by an evolutionary algorithm. A training database was created using 48 ECG recordings with reference QRS complexes. Each ECG recording is artificially contaminated with 3 types of real noise. A cost function combining the detection error probability, the mean detection jitter, and its standard deviation was defined, in order to obtain a quantitative performance evaluation of the detector. Evaluation was performed on an exercise stress test database composed of 54 real ECG recordings, with annotated QRS. The detector was configured with default parameter values, and also with the optimal values obtained from the evolutionary algorithm. The QRS detector with its optimized parameters showed a mean improvement of 4.6% compared to its performance with the default parameters. Furthermore, the use of optimized parameters led to at least the same performance than the initial parameters for all records, and the improvement was higher (up to 19.36 %) in noisy records, demonstrating the advantages of the optimized parameters in noisy environments.
Modern smartphones permit to run a large variety of applications, i.e. multimedia, games, social network applications, etc. However, this aspect considerably reduces the battery life of these devices. A possible solut...
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ISBN:
(数字)9783662455234
ISBN:
(纸本)9783662455234;9783662455227
Modern smartphones permit to run a large variety of applications, i.e. multimedia, games, social network applications, etc. However, this aspect considerably reduces the battery life of these devices. A possible solution to alleviate this problem is to offload part of the application or the whole computation to remote servers, i.e. Cloud Computing. The offloading cannot be performed without considering the issues derived from the nature of the application (i.e. multimedia, games, etc.), which can considerably change the resources necessary to the computation and the type, the frequency and the amount of data to be exchanged with the network. This work shows a framework for automatically building models for the offloading of mobile applications based on evolutionary algorithms and how it can be used to simulate different kinds of mobile applications and to analyze the rules generated. To this aim, a tool for generating mobile datasets, presenting different features, is designed and experiments are performed in different usage conditions in order to demonstrate the utility of the overall framework.
The performance of convolutional neural networks (CNNs) relies heavily on the architecture design. Recently, an increasingly prevalent trend in CNN architecture design is the utilization of ingeniously crafted buildin...
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The performance of convolutional neural networks (CNNs) relies heavily on the architecture design. Recently, an increasingly prevalent trend in CNN architecture design is the utilization of ingeniously crafted building blocks, e.g., the MixConv module, for improving the model expressivity and efficiency. To leverage the feature learning capability of multi-scale convolution while further reducing its computational complexity, this paper presents a computationally efficient yet powerful module, dubbed EMixConv, by combining parameter-free concatenation-based feature reuse with multi-scale convolution. In addition, we propose a one-shot neural architecture search (NAS) method integrating the EMixConv module to automatically search for the optimal combination of the related architectural parameters. Furthermore, an efficient multi-path weight sampling mechanism is developed to enhance the robustness of weight inheritance in the supernet. We demonstrate the effectiveness of the proposed module and the NAS algorithm on three popular image classification tasks. The developed models, dubbed EMixNets, outperform most state-of-the-art architectures with fewer parameters and computations on the CIFAR datasets. On ImageNet, EMixNet is superior to a majority of compared methods and is also more compact and computationally efficient.
The primary challenge in addressing dynamic multi-objective optimization problems (DMOPs) is the rapid tracking of optimal solutions. Although methods based on transfer learning have shown remarkable performance in ta...
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The primary challenge in addressing dynamic multi-objective optimization problems (DMOPs) is the rapid tracking of optimal solutions. Although methods based on transfer learning have shown remarkable performance in tackling DMOPs, most existing methods overlook the potential relationships between individuals within the population and those from historical environments. Consequently, they fail to adequately exploit historical information. To this end, this study proposes a dynamic multi-objective optimization algorithm based on probability-driven prediction and correlation-guided individual transfer (PDP&CGIT), which consists of two strategies: probability-driven prediction (PDP) and correlation-guided individual transfer (CGIT). Specifically, the PDP strategy analyzes the distribution of population characteristics and constructs a discriminative predictor based on a probability-annotation matrix to classify high-quality solutions from numerous randomly generated solutions within the decision space. Moreover, from the perspective of individual evolution, the CGIT strategy analyzes the correlation between current elite individuals and those from the previous moment. It learns the dynamic change pattern of the individuals and transfers this pattern to new environments. This is to maintain the diversity and distribution of the population. By integrating the advantages of these two strategies, PDP&CGIT can efficiently respond to environmental changes. Extensive experiments were performed to compare the proposed PDP&CGIT with five state-of-the-art algorithms across the FDA, F, and DF test suites. The results demonstrated the superiority of PDP&CGIT.
The matrix adaptation evolution strategy is a simplified covariance matrix adaptation evolution strategy with reduced computational cost. Using it as a search engine, several algorithms have been recently proposed for...
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The matrix adaptation evolution strategy is a simplified covariance matrix adaptation evolution strategy with reduced computational cost. Using it as a search engine, several algorithms have been recently proposed for constrained optimization and have shown excellent performance. However, these algorithms require the simultaneous application of multiple techniques to handle constraints, and also require gradient information. This makes them inappropriate for handling non-differentiable functions. This paper proposes a new matrix adaption evolutionary strategy for constrained optimization using helper and equivalent objectives. The method optimizes two objectives but with no need for special handling of infeasible solutions and without gradient information. A new mechanism is designed to adaptively adjust the weights of the two objectives according to the convergence rate. The efficacy of the proposed algorithm is evaluated using computational experiments on the IEEE CEC 2017 Constrained Optimization Competition benchmarks. Experimental results demonstrate that it outperforms current state-ofthe-art evolutionary algorithms. Furthermore, this paper provides sufficient conditions for the convergence of helper and equivalent objective evolutionary algorithms and proves that using helper objectives can reduce the likelihood of premature convergence.
This study covers the review of algorithms developed for the optimum design of steel skeletal structures from the first article published in 1960 until to date. The paper initially describes the mathematical formulati...
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This study covers the review of algorithms developed for the optimum design of steel skeletal structures from the first article published in 1960 until to date. The paper initially describes the mathematical formulation of a simple truss structural design problem. The early optimum design algorithms that were based on mathematical programming techniques where the design variables are assumed to be continuous are reviewed. The optimum design of steel framed structures necessitates the selection of steel profiles from the standard list of discrete steel sections and requires the satisfaction of design code provisions. Both mathematical programming and optimality criteria techniques need more capability to produce solution to this type of optimum design problems. Soft computing techniques emerged recently provide solution directly without needing any approximation. These techniques are classified and reviewed and their use in obtaining the optimum solution of actual industrial steel design applications is given.
This work considers development of dedicated evolutionary algorithms (EA) with several new specialized acceleration techniques introduced. Our long-term research is oriented towards development of efficient solution m...
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ISBN:
(纸本)9788494284472
This work considers development of dedicated evolutionary algorithms (EA) with several new specialized acceleration techniques introduced. Our long-term research is oriented towards development of efficient solution methods for a wide class of large, non-linear, constrained optimization problems. We are presenting here a preliminary application of the improved EA to sample benchmark problems of residual stresses analysis. The final objective of our research is such analysis done for railroad rails, and vehicle wheels. Knowledge of the tensile residual stresses is crucial for reliable prediction of rails and wheels service life resulting from their fatigue failure. Both the theoretical and experimental investigations of residual stresses may be expressed in terms of large, non-linear, constrained optimization problems. Due to the size and complexity of the optimization problems involved, our research is focused, first of all, on the EA efficiency increase.
This paper deals with evolutionary algorithms (EAs) assisted by surrogate evaluation models or metamodels (Metamodel-Assisted EAs, MAEAs) which are further accelerated by exploiting the Principal Component Analysis (P...
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ISBN:
(纸本)9788494284472
This paper deals with evolutionary algorithms (EAs) assisted by surrogate evaluation models or metamodels (Metamodel-Assisted EAs, MAEAs) which are further accelerated by exploiting the Principal Component Analysis (PCA) of the elite members of the evolving population. PCA is used to (a) guide the application of evolution operators and (b) train metamodels, in the form of radial basis functions networks, on patterns of smaller dimension. Compared to previous works by the same authors, this paper also proposes a new way to apply the PCA technique. In particular, the front of non-dominated solutions is divided into sub-fronts and the PCA is applied "locally" to each sub-front. The proposed method is demonstrated in multi-objective, constrained, aerodynamic optimization problems.
evolutionary algorithms have shown their effectiveness in solving sparse multi-objective optimization problems (SMOPs). However, for most of the existing multi-objective optimization algorithms (MOEAs) for solving SMO...
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ISBN:
(纸本)9789819722716;9789819722723
evolutionary algorithms have shown their effectiveness in solving sparse multi-objective optimization problems (SMOPs). However, for most of the existing multi-objective optimization algorithms (MOEAs) for solving SMOPs, their search granularity keeps the same for all the decision variables, which leads to significant performance deterioration when dealing with SMOPs in high-dimensional decision spaces. To tackle the issue, in this paper, a non-uniform clustering based evolutionary algorithm, termed NUCEA, is proposed for solving large-scale SMOPs. The proposed algorithm divides the decision variables into multiple groups with varying sizes, so as to reduce the search space with different granularity. These clustering outcomes inspire the development of new genetic operators, which have been proven to efficiently perform dimensionality reduction when approximating sparse Pareto optimal solutions. Experimental results on both benchmark and real-world SMOPs have shown that the proposed algorithm has significant advantages in comparison with the state-of-the-art evolutionary algorithms.
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