检索结果-内蒙古大学图书馆

Multidisciplinary modeling and simulation framework for launch vehicle system dynamics and control

ACTA ASTRONAUTICA 2020年 170卷 652-664页

作者： Briese, Lale Evrim Acquatella, Paul B. Schnepper, Klaus DLR German Aerosp Ctr Inst Syst Dynam & Control D-82234 Oberpfaffenhofen Germany

Future concepts and key technologies for reusable launch vehicles are currently investigated by the DLR project AKIRA, focusing on vertical takeoff and horizontal landing (VTHL), as well as horizontal takeoff and horizontal landing (HTHL) concepts. Dedicated developments of multidisciplinary frameworks for launch vehicle modeling and preliminary design optimization have been presented in the relevant literature. These activities are often performed by several independent and discipline-specific tools;such an approach can only account for limited interactions of the involved disciplines with the overall system dynamics. Therefore, the objective of this paper is to focus on a multidisciplinary launch vehicle dynamics modeling, guidance, and control framework to support reusable launch vehicle design activities at DLR while taking into account the highly interconnected disciplines involved and changing environmental conditions. The modeling framework is based on the object-oriented, multidisciplinary, and equation-based modeling language MODELICA. Dedicated 3-DOF and 6-DOF model implementations, covering the kinematics and dynamics formulation, environmental effects, aerodynamics, and propulsion models are presented. Within this framework, a method to obtain a direct connection between 3-DOF and 6-DOF models is shown. This is done by considering results from the trajectory optimization package 'trajOpt' in combination with nonlinear 6-DOF inverse models obtained automatically by MODELICA. Angular rates and resulting moments can be retrieved by this intermediate 6-DOF modeling approach for subsequent controllability studies. We discuss some of these benefits in terms of nonlinear flight control simulations for an HTHL reusable launch vehicle concept.

关键词： Reusable launch vehicles Launch vehicle system dynamics object-oriented modeling Nonlinear inverse models Flight dynamics

来源：评论

学校读者我要写书评

暂无评论

Packed bed thermal energy storage model - Generalized approach and experimental validation

引用

APPLIED THERMAL ENGINEERING 2014年第1期73卷 245-252页

作者： Opitz, Florian Treffinger, Peter Offenburg Univ Appl Sci D-77652 Offenburg Germany

Packed beds serve as thermal energy storages (TES) and heat exchangers (HEX) in different technological applications. In this paper, a general heterogeneous model of heat transfer in packed beds is developed. It is implemented by lumped element formulation in object-oriented modeling language Modelica and is successful validated with data sets taken from two different experiments reported in literature. The main advantages of the introduced model are the general, theory-based approach and the lumped element formulation in Modelica. The first point mentioned above should allow to simulate a packed bed TES/HEX without the necessity applying measured data for model calibration or to apply specific heat transfer correlations with restricted application. The second point establishes the possibility to integrate the TES/HEX model within plant models of larger scale without increasing the simulation time drastically. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Thermal energy storage Packed bed object-oriented modeling Modelica System model Lumped element model

来源：评论

学校读者我要写书评

暂无评论

Formalization of the whole-part relationship in the unified modeling language

引用

IEEE TRANSACTIONS ON SOFTWARE ENGINEERING 2003年第5期29卷 459-470页

作者： Barbier, F Henderson-Sellers, B Le Parc-Lacayrelle, A Bruel, JM Univ Pau & Pays Adour LIUPPA F-64013 Pau France Univ Technol Sydney Broadway NSW 2007 Australia

A formal definition for the semantics of the Whole-Part relationship in the Unified modeling Language or UML is introduced. This provides a fully directly usable specification which that can be incorporated into version 2.0 of UML. An improvement to the,current metamodel fragment relating to relationships is proposed, supplemented by the introduction of axioms expressed in the object Constraint Language or OCL. The overall formalization relates to a clear and concise emphasis on carefully enunciated (primary) characteristics that apply to all instances of a new Whole-Part metatype. Specific kinds of the Whole-Part relationship are defined in terms of secondary characteristics, which must be possessed by subtypes: In UML 1.4, these are Aggregation (a.k.a. white diamond) and Composition (a.k.a. black diamond). Primary and secondary characteristics may then be consistently combined with. each other.. Consequently, this allows the possible introduction of supplementary forms of Whole-Part. Such a revision is necessary since Aggregation and Composition in UML 1.4 do not cover the full spectrum of Whole-Part theory.

关键词： object-oriented modeling UML whole-part relationship aggregation composition

来源：评论

学校读者我要写书评

暂无评论

In-silico hemodynamic ramp testing of ventricular assist device implanted patients using acausal cardiovascular-VAD modeling

引用

ARTIFICIAL ORGANS 2023年第9期47卷 1452-1463页

作者： Mehmood, Khunsha Arshad, Munam Lazoglu, Ismail Kucukaksu, Deniz Suha Bakuy, Vedat Koc Univ Dept Mech Engn Istanbul Turkiye Baskent Univ Istanbul Hlth Applicat & Res Ctr Dept Cardiovasc Surg Istanbul Turkiye

Background: While cardiovascular system and mechanical circulatory support devices are efficiently model the effect of disease and assistance, they can also lend valuable insights into clinical procedures. This study demonstrates the use of a CVS-VAD model for an invasive procedure;hemodynamic ramp testing, ***: The CVS model is developed using validated models in literature, using Simscape (TM). An analytically derived pump model is calibrated for the HeartWare VAD. Dilated cardiomyopathy is used as an illustrative example of heart failure, and heart failure patients are created virtually by calibrating the model with requisite disease parameters obtained from published patient data. A clinically applied ramp study protocol is adopted whereby speed optimization is performed following clinically accepted hemodynamic normalization criteria. Trends in hemodynamic variables in response to pump speed increments are obtained. Optimal speed ranges are obtained for the three virtual patients based on target values of central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO), and mean arterial pressure (MAP) for hemodynamic ***: Appreciable speed changes in the mild case (300 rpm), slight changes in the moderate case (100 rpm), and no changes in the simulated severe case are ***: The study demonstrates a novel application of cardiovascular modeling using an open-source acausal model, which can be potentially beneficial for medical education and research.

关键词： HeartWare object-oriented modeling optimal hemodynamics Simscape

来源：评论

学校读者我要写书评

暂无评论

A framework to support customer-company interaction in mass customization environments

引用

COMPUTERS IN INDUSTRY 2004年第2期54卷 115-135页

作者： Frutos, JD Borenstein, D Univ Fed Rio Grande do Sul Escola Adm BR-90010460 Porto Alegre RS Brazil

In the new and emerging mass customization (MC) strategy, where companies and clients cooperate either to design or to assemble a customized product or service, there exists a great need for a mechanism to manage and control information flow among the collaborative business units. The aim of this paper is to present the design and implementation of an information system framework for agile interactions between companies and customers in an MC environment. The underlying philosophy of this framework is to combine Internet-based technology and object-oriented programming (OOP), and offer smart tools that allow customers to interact rapidly and responsively with MC production systems. (C) 2003 Elsevier B.V. All rights reserved.

关键词： mass customization object-oriented modeling information systems user involvement agile interaction

来源：评论

学校读者我要写书评

暂无评论

Dynamic modeling and simulation of a solar-assisted multi-effect distillation plant

引用

DESALINATION 2015年 357卷 65-76页

作者： de la Calle, Alberto Bonilla, Javier Roca, Lidia Palenzuela, Patricia CIEMAT Plataforma Solar Almeria Tabemas 04200 Almeria Spain Univ Almeria La Canada De San Urbano 04120 Almeria Spain

This paper presents a dynamic model of a solar-assisted multi-effect distillation (MED) plant, carrying on with the previous work "Dynamic modeling and performance of the first cell of a multi-effect distillation plant" (de la Calle et al., 2014). The dynamic model has been designed according to the experience with an experimental solar thermal desalination system erected at CIEMAT-Plataforma Solar de Almeria (PSA). The mathematical formulation based on physical principles describes the main heat and mass transfer phenomena in this kind of facilities. The model was implemented using the equation-based object-oriented Modelica modeling language. Based on a modular and hierarchical modeling, different specific-phenomenon submodels have been developed. They have been interconnected between them, thus making a three level deep hierarchy. All the submodels have been calibrated and validated with experimental data. The numerical predictions show a good agreement with measured data. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Solar desalination Falling film evaporation and condensation object-oriented modeling Modelica

来源：评论

学校读者我要写书评

暂无评论

Generation of alternative methods for managing raw materials to support decision-making in the dairy industry

引用

FOOD AND BIOPRODUCTS PROCESSING 2022年第0期133卷 140-152页

作者： Jachimczyk, Ewelina Myhan, Ryszard Univ Warmia & Mazury Fac Tech Sci Oczapowskiego 2 PL-10719 Olsztyn Poland

The dairy industry is a unique branch of the food production sector, where various decisions have to be made concerning the type and quantity of the manufactured products and the layout of processing lines. The literature on the subject is relatively limited. Therefore, an attempt was made in this study to support decision making in the dairy industry. The article proposes a general methodology for modeling dairy production systems which are characterized by numerous interdependent and concurrent processing operations. The proposed method relies on the object-oriented modeling technique and graph theory, and it can be used to model the equipment and layout of production lines. The method enables multivariate simulations of the production process involving a specific batch of raw materials. The simulated variants differ in the configuration of the production line and/or the allocation of raw materials (semi-finished products) to different segments of the production line. The tested model was verified and validated, and the average relative error of estimation was 3.27% for butter production and 2.46% for buttermilk production. The proposed method could support decision-making in the process of selecting the production strategy, including the assortment and quantity of the manufactured products, and the configuration of production lines.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

关键词： Decision processes Graph theory object-oriented modeling Production Dairy processing

来源：评论

学校读者我要写书评

暂无评论

An approach to distributed building modeling on the basis of versions and changes

引用

ADVANCED ENGINEERING INFORMATICS 2011年第2期25卷 297-310页

作者： Koch, Christian Firmenich, Berthold Ruhr Univ Bochum Inst Computat Engn Akad Rat D-44801 Bochum Germany CADEMIA Consult GmbH D-65719 Hofheim Germany

Actors involved in the computer-supported design process work together towards a common goal - the design of a building. Current collaboration approaches often focus on versioned and distributed building models, which describe virtual building states on the basis of the object-oriented method. State changes (for example moving a wall or modifying its material) remain unconsidered and lead to inconsistency problems when exchanging, comparing and merging versioned building models. This paper presents a new modeling approach that combines existing state-oriented descriptions of a virtual building with additional change-oriented information by means of design steps denoted as modeling operations. A new language is defined for the formal description of modeling operations. These operations establish a standardized processing interface for existing building models, can represent design intents, enhance current models with change semantics and add to the consistency of these models. Moreover, this paper presents new concepts for intra-domain collaboration and model management that overcome current limitations when exchanging, comparing and merging versioned building models. The pilot implementation and some project scenarios in industry verify that current design processes can benefit in principle from combined state-oriented and change-oriented building information. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： Collaboration Versioning Change management object-oriented modeling Building information modeling Diff and merge

来源：评论

学校读者我要写书评

暂无评论

Development of virtual-labs for education in chemical process control using Modelica

引用

COMPUTERS & CHEMICAL ENGINEERING 2012年 39卷 170-178页

作者： Martin-Villalba, Carla Urquia, Alfonso Dormido, Sebastian UNED Dept Informat & Automat Madrid 28040 Spain

Virtual-labs are useful tools for education in chemical process control. A novel approach to virtual-lab implementation using the Modelica language is presented. This approach has the following advantages. Firstly, existing Modelica models can be employed to develop virtual-labs. If new models need to be programmed, the use of Modelica reduces considerably the modeling effort. Secondly, as the complete virtual-lab is described in Modelica, virtual-lab developers don't need to use programming languages. Finally, virtual-labs can be easily distributed to the users, who don't need to install any additional software. The proposed approach is based on the application of a methodology for interactive model development, and two software tools: a free Modelica library, named Interactive (http://***/Interactive), and the Dymola modeling environment. Several virtuallabs have been implemented and successfully applied to education in chemical process control. The development of a virtual-lab based on a complex model of a double-pipe heat exchanger is discussed. (c) 2011 Elsevier Ltd. All rights reserved.

关键词： Chemical process education Control education Virtual laboratory Modelica object-oriented modeling

来源：评论

学校读者我要写书评

暂无评论

INTEGRATED INFORMATION modeling FOR CIM

COMPUTER INTEGRATED MANUFACTURING SYSTEMS

引用

COMPUTER INTEGRATED MANUFACTURING SYSTEMS 1991年第3期4卷 123-131页

作者： MERTINS, K SUSSENGUTH, W FRAUNHOFER INST PROD ANLAGEN & KONSTRUKT TECH FHG DEPT PROD PLANNINGW-1000 BERLIN 10GERMANY

The development of strategic plans for the stepwise introduction of computer integrated manufacturing requires models and modelling techniques to describe the business processes, functions and the required data and their relation to the desired system components. Several modelling methods have been analyzed. The fundamental deficiency is the missing integration between the process and the data models from the enterprise viewpoint. The paper shows the key issues of an object-oriented (OO) modelling method which can be used for CIM-planning as well as for the integration of CIM-standards, e.g. STEP, which are currently under development in European and international commities. The main OO-features like encapsulation, inheritance and the class concept were used to describe enterprise object-classes and the processes which change the instances of these classes. The feature-structure of the object classes and the aggregation to complete models were shown.

关键词： CIM-ARCHITECTURE ENTERPRISE modeling object-oriented modeling

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：