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Almeroth T.,Thuringian State Authority of Metrology and Verification | Kuhn O.,Thuringian State Authority of Metrology and Verification | Linss G.,TU Ilmenau | Lemke A.,Society for the Promotion of Applied Computer Science | Kramny J.,EnBW
14th Joint International IMEKO TC1, TC7, TC13 Symposium on Intelligent Quality Measurements - Theory, Education and Training 2011, Held in Conj. with the 56th IWK Ilmenau University of Technology | Year: 2011

This paper deals with various methods to estimate the lifetime of smart meters regarding its measurement features. Shorter innovation cycles lead to additional and/or exchangeable functional components resulting in a change of the reliability. The procedure presented in this paper is a new methodical approach. It combines well-known approaches of technical reliability with a consideration of a priori knowledge. In particular, the state of measuring characteristic on several points of time is observed. The observation leads to prediction of a realistic period of utilization.


Voll P.,RWTH Aachen | Lampe M.,RWTH Aachen | Wrobel G.,Society for the Promotion of Applied Computer Science | Bardow A.,RWTH Aachen
Proceedings of the 24th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2011 | Year: 2011

A novel approach for the model-based superstructure-free synthesis and optimization of distributed energy supply systems is proposed. While current methods request the designer to define a superstructure which subsequently is optimized, the presented approach exploits the nature of evolutionary algorithms to allow for a superstructure-free synthesis and optimization. A mutation operator replaces parts of energy supply structures by alternative designs. Thereby, the a priori specification of a superstructure can be avoided. The mutation operator chooses alternative designs based on a set of replacement rules. To minimize both the number of replacement rules and meaningless design alternatives generated by this operator, all considered energy conversion technologies are classified into a hierarchically-structured graph, the so-called energy conversion hierarchy. This hierarchy allows for an efficient definition of all reasonable connections between the regarded components through a minimal set of generic replacement rules. The presented approach balances richness of the available design space and computational efficiency. The method is applied to the synthesis of a heating and cooling system, which is optimized with respect to the net present value. It is shown that the presented method can be used to tackle both retrofit and grassroots design problems.


Marchenko M.,Leibniz University of Hanover | Behrens B.-A.,Leibniz University of Hanover | Wrobel G.,Society for the Promotion of Applied Computer Science | Scheffler R.,Society for the Promotion of Applied Computer Science | Plessow M.,Society for the Promotion of Applied Computer Science
Computer-Aided Design and Applications | Year: 2011

The modeling process of complex assemblies with modern parametric 3D CAD systems generates a large network of various parametric dependencies and parameter information that is difficult to manage. In this paper, a new method and a software solution for extraction and visualization of all parametric information within 3D CAD models are presented. The requirements for the visualization of complex 3D CAD models are discussed and an overall solution concept is described. Based on the general structural analysis of the parametric 3D models, a CAD system-independent graphical language with two forms of visualization will be introduced. A data model to store parametric information from CAD models, as well as a method to export them has been developed. This paper also presents the implementation of the method in CATIA V5 and the validation on a number of CAD models. © 2011 CAD Solutions, LLC.


Meyer B.,RWTH Aachen | Voll P.,RWTH Aachen | Kirschbaum S.,Society for the Promotion of Applied Computer science | Bardow A.,RWTH Aachen
Proceedings of the 26th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2013 | Year: 2013

This work presents a methodological framework for MILP modeling and optimization of distributed energy supply systems (DESS) with nonlinear system characteristics. The required MILP linearization is based on a multivariate piecewise-affine (PWA) surrogate modeling approach. A machine learning algorithm using Model Trees is employed to enable adjustments of model accuracy and to ensure an efficient discretization. The MILP component models are assembled to a DESS superstructure, which is optimized with respect to system structure, equipment sizing and load dispatch. During optimization, an iterative model refinement procedure is used to adapt the multivariate linear discretization to realize a prescribed prediction accuracy. The features of the presented modeling framework are demonstrated for the optimal synthesis of a refrigeration system.


Voll P.,RWTH Aachen | Kirschbaum S.,Society for the Promotion of Applied Computer Science | Bardow A.,RWTH Aachen
Proceedings of the 23rd International Conference on Efficiency, Cost, Optimization, Simulation, and Environmental Impact of Energy Systems, ECOS 2010 | Year: 2010

The analysis and optimization of industrial energy systems pose non-trivial, multi-criteria problems. Today, solving these problems can be supported by system simulation. A simulation's applicability to practical problems, however, is strongly depending on the level of detail of the physical models employed. This paper evaluates quasi-stationary simulation based on rather simple models with regard to its applicability to industrial energy consultancy. For this purpose, a simplified quasi-stationary and a full dynamic model of an actual heating system are developed. Simulation is used to quantify the impact of two measures forthe reduction of the heating system's energy use. Both models are compared with regard to time and effort to perform the system modeling, the quality of their simulation results, and necessary computing time. It is shown that the simplified quasi-stationary approach minimizes time and effort to perform the system modeling and simulation. Moreover, it yields sufficiently accurate results when integral values are of main interest. This is demonstrated for the case studies investigated within this paper and applies to most tasks within the scope of industrial energy consultancy.


Voll P.,RWTH Aachen | Lampe M.,RWTH Aachen | Wrobel G.,Society for the Promotion of Applied Computer Science | Bardow A.,RWTH Aachen
Energy | Year: 2012

A novel approach is proposed for the superstructure-free synthesis and optimization of distributed energy supply systems (DESS) by exploiting the nature of evolutionary algorithms. Current approaches require the designer to define a superstructure, which subsequently is optimized. In the presented method, the a priori specification of a superstructure is avoided: A mutation operator employs generic replacement rules to replace parts of energy supply systems by alternative designs. To minimize both the number of replacement rules and meaningless design alternatives generated during mutation, all energy conversion technologies are classified into the so-called energy conversion hierarchy (ECH). The ECH allows for an efficient definition of all reasonable connections between the regarded components, and the definition of generic replacement rules. Thereby, the hierarchy-supported approach balances richness of the available design space and computational efficiency. In addition, the convenient description of the design space allows for an easy addition of technologies into the optimization problem. The proposed approach thus provides an expandable framework for optimizing DESS. The method is applied to the synthesis of a heating and cooling system. The presented approach efficiently solves retrofit and grassroots design problems. It automatically identifies complex solutions such as trigeneration demonstrating the power of the suggested optimization framework. © 2012 Elsevier Ltd.


Gunther S.,Fraunhofer Institute for Mechanics of Materials | Teuscher N.,Fraunhofer Institute for Mechanics of Materials | Heilmann A.,Fraunhofer Institute for Mechanics of Materials | Hansel R.,Research Institute of Leather and Plastic Sheeting | And 2 more authors.
Journal of Adhesion Science and Technology | Year: 2011

Atmospheric pressure plasma discharges are often used to modify surfaces of polymer films due to their excellent ability to be integrated in the manufacturing line. The plasma treatment leads to surface activation and is employed to improve printability or adhesion. These effects are well known, however there is a necessity for a process control to prove the efficiency and the homogeneity of the modification, and furthermore to have a method to ensure quality requirements or for the description of the complex modification processes. In this study, optical emission spectroscopy was utilized to investigate the plasma of a dielectric barrier discharge used for treating polyethylene films. The aim was to find correlations between both the influences of plasma parameters as well as the reactions in the plasma and the resulting surface properties. The surface modifications were analyzed by contact angle measurements and X-ray photoelectron spectroscopy (XPS). © 2011 Koninklijke Brill NV, Leiden.


Voll P.,RWTH Aachen | Klaffke C.,RWTH Aachen | Hennen M.,RWTH Aachen | Kirschbaum S.,Society for the Promotion of Applied Computer science | Bardow A.,RWTH Aachen
Computer Aided Chemical Engineering | Year: 2012

A novel approach is presented for the automated generation of models representing superstructures for the synthesis and optimization of distributed energy supply systems (DESS). Based on a basic problem description (load cases, available technologies, and topographical constraints), the proposed algorithm automatically generates a model accounting for time-varying load profiles and part-load dependent operating efficiencies. Building upon the P-graph approach, the derived superstructure is extended to include multiple redundant conversion units as required for DESS optimization. In the present implementation, a GAMS model is generated that can be readily optimized. The approach is applied to the retrofit synthesis of the energy supply system of an industrial site. It is shown that the automated procedure provides a convenient and efficient optimization framework for DESS. © 2012 Elsevier B.V.


Barre S.,Society for the Promotion of Applied Computer Science | Dobler D.,Society for the Promotion of Applied Computer Science | Meyer A.,Society for the Promotion of Applied Computer Science
INTERNOISE 2014 - 43rd International Congress on Noise Control Engineering: Improving the World Through Noise Control | Year: 2014

Room impulse response measurement using deterministic signals like sine sweeps is a well-established method to obtain objective parameters that describe the acoustic field in 3-dimensional space. Combined with conventional delay-and-sum beamforming, it becomes a very powerful tool offering precise information about the behaviour of acoustic waves inside or between rooms. More precisely, the use of a transparent array allows us to process the microphone's signals directly by spectral division, a linear deconvolution method, and to analyze the resulting room impulse responses through beamforming. This permits a precise localization of the direct sound and the early reflections over time and space. Additionally, the high signal-to-noise ratio and decorrelation properties offered by the method permit to highlight leakage and airborne sound transmission paths between rooms. Finally, the repeatability of the method allows for a comparison of measurements of various room configurations, for example in the case of acoustic treatment and optimization.

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