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71.
Fuzzy grey relational analysis for software effort estimation 总被引:1,自引:1,他引:0
Accurate and credible software effort estimation is a challenge for academic research and software industry. From many software
effort estimation models in existence, Estimation by Analogy (EA) is still one of the preferred techniques by software engineering
practitioners because it mimics the human problem solving approach. Accuracy of such a model depends on the characteristics
of the dataset, which is subject to considerable uncertainty. The inherent uncertainty in software attribute measurement has
significant impact on estimation accuracy because these attributes are measured based on human judgment and are often vague
and imprecise. To overcome this challenge we propose a new formal EA model based on the integration of Fuzzy set theory with
Grey Relational Analysis (GRA). Fuzzy set theory is employed to reduce uncertainty in distance measure between two tuples
at the k
th
continuous feature ( | ( xo(k) - xi(k) | ) \left( {\left| {\left( {{x_o}(k) - {x_i}(k)} \right.} \right|} \right) .GRA is a problem solving method that is used to assess the similarity between two tuples with M features. Since some of these features are not necessary to be continuous and may have nominal and ordinal scale type, aggregating
different forms of similarity measures will increase uncertainty in the similarity degree. Thus the GRA is mainly used to
reduce uncertainty in the distance measure between two software projects for both continuous and categorical features. Both
techniques are suitable when relationship between effort and other effort drivers is complex. Experimental results showed
that using integration of GRA with FL produced credible estimates when compared with the results obtained using Case-Based
Reasoning, Multiple Linear Regression and Artificial Neural Networks methods. 相似文献
72.
The probabilistic visual tracking methods using color histograms have been proven to be robust to target model variations and background illumination changes as shown by the recent research. However, the required computational cost is high due to intensive image data processing. The embedded solution of such algorithms become challenging due to high computational power demand and algorithm complexity. This paper presents a hardware/software co-design architecture for implementation of the well-known kernel based mean shift tracking algorithm. The design uses color histogram of the target as tracking feature. The target is searched in the consecutive images by maximizing the statistical match of the color distributions. The target localization is based on gradient based iterative search instead of exhaustive search which makes the system capable of achieving frame rate up to hundreds of frames per second while tracking multiple targets. The design, which is fully standalone, is implemented on a low-cost medium-size field programmable gate array (FPGA) device. The hardware cost of the design is compared with some other tracking systems. The performance of the system in terms of speed is evaluated and compared with the software based implementation. It is expected that the proposed solution will find its utility in applications like embedded automatic video surveillance systems. 相似文献
73.
Arya Aghili Ashtiani Mohammad Bagher Menhaj 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2010,14(6):545-557
In this paper, we study and formulate a BP learning algorithm for fuzzy relational neural networks based on smooth fuzzy norms
for functions approximation. To elaborate the model behavior more, we have used different fuzzy norms led to a new pair of
fuzzy norms. An important practical case in fuzzy relational equations (FREs) is the identification problem which is studied
in this work. In this work we employ a neuro-based approach to numerically solve the set of FREs and focus on generalized
neurons that use smooth s-norms and t-norms as fuzzy compositional operators. 相似文献
74.
Hossam Mohammad Khalil Mohammad El-Bardini 《Expert systems with applications》2011,38(11):14249-14256
The performance of a model-based control system depends strongly on the accuracy of the process model used. LS-SVM is a powerful method for modeling nonlinear systems. The main objective of this paper is to implement a conventional controller based on LS-SVM model for hydraulic motor. An off-line model is first identified based on LS-SVM, then via simulation tests the parameters of the discrete PI-Controller and its velocity-form are obtained then the controller parameters are applied experimentally for the hydraulic motor as a speed controller. The system performance has been evaluated; results show good performance over a wide range of operating conditions and load disturbances. 相似文献
75.
A predictive functional controller based on ARMarkov model structure has been designed to control welding current and arc voltage in a GMAW process. The closed loop system performance is investigated through computer simulations and is compared by those achieved from implementing two commonly used controllers i.e. PI and feedback linearization based PID. The local stability of the closed loop system is analyzed in the presence of uncertainties in the linearized model of the process as well as the control parameters. Finally it is shown that the proposed controller performs like a PI controller along with a pre-filter compensator. 相似文献
76.
In this paper, a new algorithm for solving constrained nonlinear programming problems is presented. The basis of our proposed algorithm is none other than the necessary and sufficient conditions that one deals within a discrete constrained local optimum in the context of the discrete Lagrange multipliers theory. We adopt a revised particle swarm optimization algorithm and extend it toward solving nonlinear programming problems with continuous decision variables. To measure the merits of our algorithm, we provide numerical experiments for several renowned benchmark problems and compare the outcome against the best results reported in the literature. The empirical assessments demonstrate that our algorithm is efficient and robust. 相似文献
77.
78.
Mohammad HammoudAuthor Vitae Sangyeun ChoAuthor VitaeRami MelhemAuthor Vitae 《Journal of Parallel and Distributed Computing》2011,71(6):889-896
This paper describes Constrained Associative-Mapping-of-Tracking-Entries (C-AMTE), a scalable mechanism to facilitate flexible and efficient distributed cache management in large-scale chip multiprocessors (CMPs). C-AMTE enables fast locating of cache blocks in CMP cache schemes that employ one-to-one or one-to-many associative mappings. C-AMTE stores in per-core data structures tracking entries to avoid on-chip interconnect traffic outburst or long distance directory lookups. Simulation results using a full system simulator demonstrate that C-AMTE achieves improvement in cache access latency by up to 34.4%, close to that of a perfect location strategy. 相似文献
79.
Jafar Biazar Behzad Ghanbari Mehdi Gholami Porshokouhi Mohammad Gholami Porshokouhi 《Computers & Mathematics with Applications》2011,61(4):1016-1023
In this paper, He’s homotopy perturbation method is applied to solve non-linear systems of mixed Volterra–Fredholm integral equations. Two examples are presented to illustrate the ability of the method. Also comparisons are made between the Adomian decomposition method and the homotopy perturbation method. The results reveal that He’s homotopy perturbation method is very effective and simple and in these examples leads to the exact solutions. 相似文献
80.
A note on the stability of fractional order systems 总被引:1,自引:0,他引:1
In this paper, a new approach is suggested to investigate stability in a family of fractional order linear time invariant systems with order between 1 and 2. The proposed method relies on finding a linear ordinary system that possesses the same stability property as the fractional order system. In this way, instead of performing the stability analysis on the fractional order systems, the analysis is converted into the domain of ordinary systems which is well established and well understood. As a useful consequence, we have extended two general tests for robust stability check of ordinary systems to fractional order systems. 相似文献