检索结果-内蒙古大学图书馆

4th International Conference on High Performance Structures and Materials

作者： Zula, T. Kravanja, S. Univ Maribor Fac Civil Engn SLO-2000 Maribor Slovenia

ISBN: (纸本)9781845641061

The paper presents the two-phase MINLP topology and standard sizes optimization of a single-storey industrial steel building. The structure consists of main portal frames, connected with purlins. It is made from standard hot rolled I sections. The mixed-integer non-linear programming (MINLP) optimization of the structure is applied. The MINLP performs a discrete topology and standard dimension optimization, while continuous parameters (stresses, deflections, mass, costs, etc.) are calculated simultaneously inside, the continuous space. Since the discrete/continuous optimization problem of this type of structures is non-convex and highly non-linear, the Modified Outer-Approximation/Equality-Relaxation (OVER) algorithm is used for the optimization. The defined mass objective function is subjected to the set of equality and inequality constraints known from the structural analysis and dimensioning. The dimensioning of steel members is performed in accordance with Eurocode 3. The MINLP optimization is performed in two phases. In the first phase, the topology optimization of the structure at the relaxed dimensions is performed only. This phase gives a good linear global approximation to the structure for the next phase. When the optimal topology is reached, the optimization is continued at the second phase for the overall topology and standard section discrete optimization. Alongside the optimal structure mass, the optimal topology with the optimal number of portal frames and purlins as well as all standard cross-sections are obtained. The paper includes the theoretical basis and a practical example with the results of the optimization.

关键词： optimization topology optimization discrete sizes optimization mixed-integer non-linear programming MINLP industrial steel building

来源：评论

学校读者我要写书评

暂无评论

MINLP cost optimization of industrial steel building

MINLP cost optimization of industrial steel building

引用

10th International Conference on Computer Aided Design in Engineering (OPTI 2007)

作者： Kravanja, S. Zula, T. Univ Maribor Fac Civil Engn Maribor Slovenia

ISBN: (纸本)9781845640705

This paper presents the cost optimization of a single-storey industrial steel building structure. The optimization is performed by the mixed-integer non-linear programming approach, MINLP. The structure consists of the main portal frames, which are mutually connected with the purlins. All structural elements are proposed to be built up of standard hot rolled I sections. The MINLP performs the simultaneous cost, topology and discrete sizes optimization of the building structure. Since the discrete/continuous optimization problem is non-convex and highly non-linear, the Modified Outer-Approximation/Equality-Relaxation (OA/ER) algorithm has been used for the optimization. Alongside the optimal structure's costs, the optimal number of main portal frames and purlins as well as all standard cross-section sizes have been obtained.

关键词： structural optimization cost optimization topology optimization discrete sizes optimization mixed-integer non-linear programming MINLP industrial building

来源：评论

学校读者我要写书评

暂无评论

Heuristics for the General Multiple non-linear Knapsack Problem

引用

Electronic Notes in Discrete Mathematics 2016年 55卷 69-72页

作者： Mencarelli, Luca Di Zio, Angelo Martello, Silvano CNRS UMR 7161 LIX École Polytechnique Palaiseau France Ferrari S.p.A. Maranello Italy DEI “Guglielmo Marconi” Bologna Italy

We propose heuristic algorithms for the multiple non-linear knapsack problem with separable non-convex profit and weight functions. First, we design a fast constructive algorithm that provides good initial solutions. Secondly, we improve the quality of these solutions through local search procedures. We compare the proposed methods with exact and heuristic algorithms for mixed integer non-linear programming problems, proving that our approach provides good-quality solutions in smaller CPU time. © 2016 Elsevier B.V.

关键词： Heuristic algorithm Local search mixed-integer non-linear programming Multiple non-linear knapsack problem

来源：评论

学校读者我要写书评

暂无评论

A strategy for advanced biofuel production and emission utilization from macroalgal biorefinery using superstructure optimization

引用

ENERGY 2021年 221卷 119883-119883页

作者： Dickson, Rofice Liu, J. Jay Lahore Univ Management Sci LUMS SBA Sch Sci & Engn Dept Chem & Chem Engn Lahore 54792 Pakistan Pukyong Natl Univ Dept Chem Engn Busan 48513 South Korea

The rapid increase in the emission of greenhouse gases over the years signifies the urgent need to explore fuels that emit less CO2, such as biofuels. CO2 emission can be reduced further by productively utilizing the CO2 generated during industrial processes. In this study, we have proposed a strategy to produce advanced biofuel from macroalgal biorefinery and to utilize all waste streams from processing into value-added products. To achieve this aim, we developed a novel superstructure for biorefinery process synthesis based on Saccharina japonica (macroalgae) to determine an optimal design of the biorefinery. Process integration was performed to utilize direct greenhouse gas emissions from the biorefinery and to reduce pollutant emissions and freshwater consumption. A techno-economic and environmental mixed-integer non-linear model was formulated based on this superstructure. To achieve the economic and environmental goals, two objective functions were studied: maximization of the net present value and minimization of CO2 emissions. A comprehensive sensitivity and Monte Carlo simulation model was formulated to evaluate the effects of variation in key model parameters on the overall economics and to perform the risk assessment, respectively. The minimum ethanol selling price range for the integrated design was found to be USD 0.36-0.56/L. The optimal design achieved a 90% reduction in CO2 emissions, from 4.86 kg/s to 0.42 kg/s, as well as a 38.6% reduction in freshwater consumption. The risk of the optimal design was found to be 20-44% on the basis of the minimum selling price of ethanol. Therefore, this design can be implemented as an economically and environmentally feasible approach to biofuel production. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Superstructure optimization Process synthesis Process integration Macroalgae mixed-integer non-linear programming Biofuel

来源：评论

学校读者我要写书评

暂无评论

Optimal Design and Competitive Spans of Timber Floor Joists Based on Multi-Parametric MINLP Optimization

引用

MATERIALS 2022年第9期15卷 3217页

作者： Jelusi, Primoz Kravanja, Stojan Univ Maribor Fac Civil Engn Transportat Engn & Architecture Smetanova Ulica 17 Maribor 2000 Slovenia

This study investigates the optimization of the design of timber floor joists, taking into account the self-manufacturing costs and the discrete sizes of the structure. This non-linear and discrete class of optimization problem was solved with the multi-parametric mixed-integer non-linear programming (MINLP). An MINLP optimization model was developed. In the model, an accurate objective function of the material and labor costs of the structure was subjected to design, strength, vibration and deflection (in)equality constraints, defined according to Eurocode regulations. The optimal design of timber floor joists was investigated for different floor systems, different materials (sawn wood and glulam), different load sharing systems, different vertical imposed loads, different spans, and different alternatives of discrete cross-sections. For the above parameters, 380 individual MINLP optimizations were performed. Based on the results obtained, a recommended optimal design for timber floor joists was developed. Engineers can select from the recommendations the optimal design system for a given imposed load and span of the structure. Economically suitable spans for timber floor joists structures were found. The current knowledge of competitive spans for timber floor joists is extended based on cost optimization and Eurocode standards.

关键词： structural optimization cost optimization discrete optimization mixed-integer non-linear programming MINLP timber floor joists

来源：评论

学校读者我要写书评

暂无评论

Flow shop scheduling problem with non-linear learning effects: A linear approximation scheme for non-technical users

引用

JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 2023年第1期424卷

作者： Ferraro, Augusto Rossit, Daniel Alejandro Toncovich, Adrian Univ Nacl Sur Engn Dept Ave Alem 1253 RA-8000 Bahia Blanca Buenos Aires Argentina Consejo Nacl Invest Cient & Tecn INMABB Ave Alem 1253 RA-8000 Bahia Blanca Buenos Aires Argentina

Scheduling problems with learning effect have taken a renewed interest in recent years due to increasingly personalized productions, leveraged by the capabilities provided by Industry 4.0. In this work, a learning effect problem described by an exponential curve proportional to the accumulated processing time in a flow shop type configuration was addressed. The objective to be minimized is the makespan. This problem is non-linear, which prevents it from being addressed by standard software such as spreadsheets and commercial MILP solvers. For overcoming this issue a linear approximation approach is proposed. This linear approximation approach consists in representing the exponential curve by a set of piecewise smooth lines.. The parameterization of the piecewise smooth line can be solved with spreadsheet tools, using probabilistic models that implicitly provide information about the difficulty of modeling an exponential curve by means of straight lines. Then, a MILP model was generated based on this approximation scheme, which can be solved by standard solvers such as CPLEX or Gurobi. In turn, the problem was also modeled in its MINLP format, and it was solved with a state-of-the-art MINLP solver. The results show the improvement of the linear approximation solution with respect to the MINLP solution, where improvements greater than 10% are achieved in terms of makespan.(c) 2022 Elsevier B.V. All rights reserved.

关键词： Flow shop scheduling Learning effect mixed-integer non-linear programming Makespan linear approximation

来源：评论

学校读者我要写书评

暂无评论

Reducing committed emissions of heating towards 2050: Analysis of scenarios for the insulation of buildings and the decarbonisation of electricity generation

引用

APPLIED ENERGY 2022年 325卷

作者： Kaandorp, Chelsea Miedema, Tes Verhagen, Jeroen van de Giesen, Nick Abraham, Edo Delft Univ Technol Fac Civil Engn & Geosci Dept Water Management Stevinweg 1 NL-2628 CN Delft Netherlands

Infrastructure for heat provision in the built environment needs to change remarkably to support lowering carbon emissions and achieving climate mitigation targets before 2050. We propose a computational approach for finding a mix of heat options per neighbourhood that minimises cumulative carbon emissions between 2030 and 2050, referred to as committed emissions, while at the same time adhering to technological constraints at both the household and neighbourhood scales. To establish this approach, we integrated bottom -up heat demand modelling at neighbourhood scale with a mixed-integer non-linear optimisation problem. Nine scenarios with different pathways for the insulation of buildings and the decarbonisation in electricity generation were considered and applied to three neighbourhoods in the city of Amsterdam, the Netherlands. The results show that (i) the committed emissions are ten times lower between 2030 and 2050 in scenarios in which ambitious measures are taken for the insulation of buildings and the decarbonisation in electricity generation, (ii) only in these 'ambitious scenarios' low temperature heat systems, such as heat pumps and low temperature heat networks, are optimal solutions for minimising committed emissions, (iii) if less ambitious insulation and decarbonisation measures are taken, high temperature heat options can be part of the heat mix with lowest committed emissions, and (iv) the minimum heat density for low temperature heat networks is not always achieved, creating risks for carbon lock-ins when applying these heat networks. Our results clearly indicate that pathways for the retrofitting of buildings and the decarbonisation in electricity generation need to be taken into account jointly when designing renewable and low-carbon heat systems to optimally reduce carbon emissions towards 2050 and reduce future carbon lock-ins.

关键词： Urban heat systems Committed carbon emissions Retro-fitting of the building stock Electrification of heating Carbon lock-in mixed-integer non-linear programming

来源：评论

学校读者我要写书评

暂无评论

Sustainable retrofit of petrochemical energy systems under multiple uncertainties using the stochastic optimization method

引用

COMPUTERS & CHEMICAL ENGINEERING 2021年 151卷 107374-107374页

作者： Qian, Qiming Liu, Hua He, Chang Shu, Yidan Chen, Qing L. Zhang, Bing J. Sun Yat Sen Univ Guangdong Engn Ctr Petrochem Energy Conservat Sch Chem Engn & Technol Key Lab Low Carbon Chem & Energy Conservat Guangd Zhuhai 519082 Peoples R China

We report a multi-objective stochastic mixed-integer non-linear programming (MINLP) framework for sustainable retrofit and capability expansion of traditional energy systems in petrochemical complexes. Multiple uncertainties including energy demands, solar radiation and wind speeds are considered in the optimization framework, these are characterized by historical data or normal distributions which are predefined with assumed mean values and standard variations. A stochastic reduced order model approach is introduced to describe the uncertainties by a small number of scenarios and their individual probabilities. The optimization framework further accounts for system configuration selection and sizing of the candidate energy conversion equipment, such as thermal storage units, gas turbines, boilers, steam turbines, as well as their operating capacities in each time period. A case study is investigated to demonstrate the performance of the proposed strategy and then the optimization results under three modes (deterministic, stochastic and semi-stochastic programs) are compared. (c) 2021 Elsevier Ltd. All rights reserved.

关键词： Sustainable energy system Retrofit mixed-integer non-linear programming Stochastic reduced order model Multiple uncertainties

来源：评论

学校读者我要写书评

暂无评论

The MINLP optimization approach to structural synthesis - Part II: Simultaneous topology, parameter and standard dimension optimization by the use of the linked two-phase MINLP strategy

引用

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 1998年第2期43卷 293-328页

作者： Kravanja, S Kravanja, Z Bedenik, BS Univ Maribor Fac Civil Engn SI-2000 Maribor Slovenia Univ Maribor Fac Chem & Chem Engn SI-2000 Maribor Slovenia

Part II describes the mixed-integer non-linear programming (MINLP) approach to structural synthesis where standard dimensions are added to simultaneous topology and parameter optimization. For this purpose, the mechanical superstructure has been enhanced and a special MINLP-MS model formulation for mechanical superstructures from Part I adapted to standard dimension alternatives, which give rise to complex MINLP problems that are difficult to solve. A Linked Two-Phase MINLP Strategy has been developed to efficiently accelerate the Solutions of highly combinatorial MINLP problems, performed by the Modified OA/ER algorithm. In the first phase, the strategy uses only continuous dimensions making it easier to find an optimal topology. Based on the obtained global linear approximation of the superstructure, the proposed strategy in the second phase continues to perform an overall simultaneous optimization, where standard dimensions are added as additional discrete optimization alternatives. Thus, simultaneous topology, parameter and standard dimension optimization is now performed in the second phase. The synthesis of a multiple cantilever beam, introduced in Part I, was performed in accordance with the steps proposed by the MINLP optimization approach. This approach enables the obtaining of additional savings when compared to the one in Part I. (C) 1998 John Wiley & Sons, Ltd.

关键词： structural synthesis optimization topology optimization discrete variable optimization mixed-integer non-linear programming MINLP the Modified OA/ER algorithm MINLP strategy

来源：评论

学校读者我要写书评

暂无评论

Unequal-area capability-based facility layout design problem with a heuristic decomposition-based iterative mathematical programming approach

引用

EXPERT SYSTEMS WITH APPLICATIONS 2023年 214卷

作者： Subulan, Kemal Varol, Bilge Baykasoglu, Adil Dokuz Eylul Univ Dept Ind Engn Fac Engn Izmir Turkiye Dokuz Eylul Univ Grad Sch Nat & Appl Sci Izmir Turkiye

Thus far in the available literature, capability-based facility layout design approaches were developed by only considering equal machine areas, where they are assigned to the pre-specified locations. Based on this motivation, this paper introduces a new unequal-area capability-based facility layout design (UA-CBFLD) problem for the first time in the literature. In addition to the machines' unequal-area requirements, the proper distribution of their processing capabilities over the shop floor is considered. First, a new mixed-integer non-linear programming (MINLP) model is developed. Then, a polyhedral inner-approximation method is applied to cope with nonlinear area constraints. Due to its NP-hard nature and highly non-linear structure, a heuristic decompositionbased iterative solution approach is also proposed to solve realistic size problems within a reasonable time. In order to show the validity and applicability of the proposed approach, both an illustrative example with different machine-capability overlaps and a real-life application in a manufacturing company are presented. The computational results have shown that the proposed approach has found a 33.25% better layout score (as a function of the distance and the amounts of product flows) and achieved this solution 116.64% faster than the solution of the developed MINLP model via Gurobi's standard non-linear programming solver. Furthermore, when compared to the existing cellular facility layout design of the manufacturing company, the proposed capability-based unequal-area layout design option has also 29.37% and 34.74% superior layout scores under the scenarios of equal and unequal machine areas, respectively. Moreover, the total average machine utilization has increased up to 89.6%, which is comparatively better than the current average cell utilization, i.e., 65.2%.

关键词： UA-FLP Capability-based layout design Inner-approximation method mixed-integer non-linear programming Heuristic decomposition-based approach

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：