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Moult intensity constraints along the complete moult sequence of the House Sparrow(Passer domesticus) 被引量:1
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作者 Santi Guallar Javier Quesada 《Avian Research》 SCIE CSCD 2023年第3期394-404,共11页
Sequence and intensity are two essential components of bird moult.While the moult sequences of remex tracts are highly homogenous across passerines,other tracts apparently show a high variability.Moreover,order of mou... Sequence and intensity are two essential components of bird moult.While the moult sequences of remex tracts are highly homogenous across passerines,other tracts apparently show a high variability.Moreover,order of moult activation among tracts are insufficiently known.Likewise,dynamics of moult intensity as moult progresses remains poorly known.Here,we provide detailed quantitative description of moult sequence and intensity in the House Sparrow(Passer domesticus).To understand their role,we tested two hypotheses on the:1) protection function of moult sequence,and 2) aerodynamic and physiological constraints on moult intensity.We scored percentage growth of 313 captured sparrows using the mass of the feathers of each tract(also length for remiges)to monitor moult intensity throughout the complete moult progress,which is defined as the fraction of new and growing feathers in a moulting bird relative to the total plumage.Moult sequence was highly variable both within wing coverts and among feather tracts,with moult sequence differing among all birds to some degree.We only found support for the protection function between greater coverts and both tertials and secondaries.Remex-moult intensity conformed to theoretical predictions,therefore lending support to the aerodynamic-constraint hypothesis.Furthermore,remex-moult speed plateaued during the central stages of moult progress.However,overall plumage-moult speed did not fit predictions of the physiological-constraint hypothesis,showing that the remex moult is only constrained by aerodynamics.Our results indicate that aerodynamic loss is not simply the inevitable effect of moult,but that moult is finely regulated to reduce aerodynamic loss.We propose that the moult of the House Sparrow is controlled through sequence and intensity adjustments in order to:1) avoid body and wing growth peaks;2) fulfil the protection function between some key feather tracts;3) reduce detrimental effects on flight ability;4) keep remex sequence fixed;and 5) relax remex replacement to last the whole moult duration. 展开更多
关键词 functional constraints Local polynomial regression Passerine moult Physiological constraints Raggedness
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Rheological Behaviour for Polymer Melts and Concentrated SolutionsPart Ⅱ: Material Function with Nagai Chain Constraints and Determination of Their Parameters from Flow Curves 被引量:3
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作者 Mingshi SONG Sizhu WU and Xiuyun DU(Research Institute of Polymeric Materials, Beijing University of Chemical Technology, Beijing, 100029, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1995年第2期141-152,共12页
An integral constitutive equation and a set of material functions for describing the strain history of polymer melts were formulated in terms of the Cauchy-Green and Finger tensors. A simple memory function and the de... An integral constitutive equation and a set of material functions for describing the strain history of polymer melts were formulated in terms of the Cauchy-Green and Finger tensors. A simple memory function and the dependence of ηo and τt on M3.4 were derived from the theory of non-linear viscoelasticity with constraints of entanglements for polymer melts and substituted into the Oldroye-Walters-Fredickson constitutive equation. An integral constitutive equation for polymer melts was consequently obtained. Some material functions of the constitutive equation related to certain 'test flow' are examined as follows : (1) simple steady shear flow; (2) steady elongation flow; (3) small-amplitude oscillatory shear flow; (4) stress growth upon the inception of steady shear elongation flow; (5) stress relaxation (modulus and compllance). These theoretical relations for simple steady shear flow were compared with experimental data from our laboratory and references for various polymer melts and concentrated solutions. A good agreement between the theory and experiment was achieved. 展开更多
关键词 LDPE Material Function with Nagai Chain constraints and Determination of Their Parameters from Flow Curves Rheological Behaviour for Polymer Melts and Concentrated SolutionsPart Flow GR
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Pancreas Segmentation Optimization Based on Coarse-to-Fine Scheme
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作者 Xu Yao Chengjian Qiu +1 位作者 Yuqing Song Zhe Liu 《Intelligent Automation & Soft Computing》 SCIE 2023年第9期2583-2594,共12页
As the pancreas only occupies a small region in the whole abdominal computed tomography(CT)scans and has high variability in shape,location and size,deep neural networks in automatic pancreas segmentation task can be ... As the pancreas only occupies a small region in the whole abdominal computed tomography(CT)scans and has high variability in shape,location and size,deep neural networks in automatic pancreas segmentation task can be easily confused by the complex and variable background.To alleviate these issues,this paper proposes a novel pancreas segmentation optimization based on the coarse-to-fine structure,in which the coarse stage is responsible for increasing the proportion of the target region in the input image through the minimum bounding box,and the fine is for improving the accuracy of pancreas segmentation by enhancing the data diversity and by introducing a new segmentation model,and reducing the running time by adding a total weights constraint.This optimization is evaluated on the public pancreas segmentation dataset and achieves 87.87%average Dice-Sørensen coefficient(DSC)accuracy,which is 0.94%higher than 86.93%,result of the state-of-the-art pancreas segmentation methods.Moreover,this method has strong generalization that it can be easily applied to other coarse-to-fine or one step organ segmentation tasks. 展开更多
关键词 Pancreas segmentation coarse-to-fine U-net constraint loss function
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Conceptual Modular Design of Auto Body Frame Based on Hybrid Optimization Method 被引量:1
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作者 Yonghong Zhao Changsheng Wang +3 位作者 Huanquan Yuan Yongcheng Li ChunlaiShan Wenbin Hou 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第1期351-376,共26页
This article presents a systematic research methodology of modular design for conceptual auto body frame by hybrid optimization method.A modified graph-based decomposition optimization algorithm is utilized to generat... This article presents a systematic research methodology of modular design for conceptual auto body frame by hybrid optimization method.A modified graph-based decomposition optimization algorithm is utilized to generate an optimal BIW assembly topo model composed of“potential modules”.The consistency constraint function in collaborative optimization is extended to maximize the commonality of modules and minimize the performance loss of all car types in the same product family simultaneously.A novel screening method is employed to select both“basic structures”and“reinforcement”modules based on the dimension optimization of the manufacturing elements and the optimal assembly mode;this allows for a more exhaustive modular platform design in contrast with existing methods.The proposed methodology is applied to a case study for the modular design of three conceptual auto body types in the same platform to validate its feasibility and effectiveness. 展开更多
关键词 Graph-based decomposition algorithm consistency constraint function modular design conceptual auto body
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Solution of Combined Heat and Power Economic Dispatch Problem Using Direct Optimization Algorithm 被引量:1
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作者 Dedacus N. Ohaegbuchi Olaniyi S. Maliki +1 位作者 Chinedu P. A. Okwaraoka Hillary Erondu Okwudiri 《Energy and Power Engineering》 CAS 2022年第12期737-746,共10页
This paper presents the solution to the combined heat and power economic dispatch problem using a direct solution algorithm for constrained optimization problems. With the potential of Combined Heat and Power (CHP) pr... This paper presents the solution to the combined heat and power economic dispatch problem using a direct solution algorithm for constrained optimization problems. With the potential of Combined Heat and Power (CHP) production to increase the efficiency of power and heat generation simultaneously having been researched and established, the increasing penetration of CHP systems, and determination of economic dispatch of power and heat assumes higher relevance. The Combined Heat and Power Economic Dispatch (CHPED) problem is a demanding optimization problem as both constraints and objective functions can be non-linear and non-convex. This paper presents an explicit formula developed for computing the system-wide incremental costs corresponding with optimal dispatch. The circumvention of the use of iterative search schemes for this crucial step is the innovation inherent in the proposed dispatch procedure. The feasible operating region of the CHP unit three is taken into account in the proposed CHPED problem model, whereas the optimal dispatch of power/heat outputs of CHP unit is determined using the direct Lagrange multiplier solution algorithm. The proposed algorithm is applied to a test system with four units and results are provided. 展开更多
关键词 Economic Dispatch Lagrange Multiplier Algorithm Combined Heat and Power constraints and Objective Functions Optimal Dispatch
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Parametric Duality Models for Semi-infinite Discrete Minmax Fractional Programming Problems Involving Generalized (η,ρ)-Invex Functions 被引量:4
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作者 G.J.Zalmai 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2007年第3期353-376,共24页
A semi-infinite programming problem is a mathematical programming problem with a finite number of variables and infinitely many constraints. Duality theories and generalized convexity concepts are important research t... A semi-infinite programming problem is a mathematical programming problem with a finite number of variables and infinitely many constraints. Duality theories and generalized convexity concepts are important research topics in mathematical programming. In this paper, we discuss a fairly large number of paramet- ric duality results under various generalized (η,ρ)-invexity assumptions for a semi-infinite minmax fractional programming problem. 展开更多
关键词 Semi-infinite programming discrete minmax fractional programming generalized invex functions infinitely many equality and inequality constraints parametric duality models duality theorems
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Behavioral Portfolio Selection with Loss Control 被引量:2
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作者 Song ZHANG Han Qing JIN Xun Yu ZHOU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2011年第2期255-274,共20页
In this paper we formulate a continuous-time behavioral (4 la cumulative prospect theory) portfolio selection model where the losses are constrained by a pre-specified upper bound. Economically the model is motivate... In this paper we formulate a continuous-time behavioral (4 la cumulative prospect theory) portfolio selection model where the losses are constrained by a pre-specified upper bound. Economically the model is motivated by the previously proved fact that the losses Occurring in a bad state of the world can be catastrophic for an unconstrained model. Mathematically solving the model boils down to solving a concave Choquet minimization problem with an additional upper bound. We derive the optimal solution explicitly for such a loss control model. The optimal terminal wealth profile is in general characterized by three pieces: the agent has gains in the good states of the world, gets a moderate, endogenously constant loss in the intermediate states, and suffers the maximal loss (which is the given bound for losses) in the bad states. Examples are given to illustrate the general results. 展开更多
关键词 Cumulative prospect theory portfolio choice gains and losses constraint Choquet integral quantile function
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Global Parametric Sufficient Optimality Conditions for Semi-infinite Discrete Minmax Fractional Programming Problems Involving Generalized (η,ρ)-invex Functions 被引量:1
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作者 G.J.Zalmai 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2007年第2期217-234,共18页
In this paper, we discuss a large number of sets of global parametric sufficient optimality conditions under various generalized (η,ρ)-invexity assumptions for a semi-infinite minmax fractional programming problem.
关键词 Semi-infinite programming discrete minmax fractional programming generalized invex functions infinitely many equality and inequality constraints sufficient optimality conditions
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Global Parametric Sufficient Efficiency Conditions for Semiinfinite Multiobjective Fractional Programming Problems Containing Generalized (α, η, ρ)-V-Invex Functions
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作者 G.J. Zalmai Qing-hong Zhang 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2013年第1期63-78,共16页
Abstract In this paper, we discuss numerous sets of global parametric sufficient efficiency conditions under various generalized (a,n, p)-V-invexity assumptions for a semiinfinite multiobjective fractional programmi... Abstract In this paper, we discuss numerous sets of global parametric sufficient efficiency conditions under various generalized (a,n, p)-V-invexity assumptions for a semiinfinite multiobjective fractional programming problem. 展开更多
关键词 Semiinfinite programming multiobjective fractional programming generalized invex functions infinitely many equality and inequality constraints parametric sufficient efficiency conditions.
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