• Title/Summary/Keyword: Conceptual Modeling

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Conceptual Design Optimization of Tensairity Girder Using Variable Complexity Modeling Method

  • Yin, Shi;Zhu, Ming;Liang, Haoquan;Zhao, Da
    • International Journal of Aeronautical and Space Sciences
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    • v.17 no.1
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    • pp.29-36
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    • 2016
  • Tensairity girder is a light weight inflatable fabric structural concept which can be used in road emergency transportation. It uses low pressure air to stabilize compression elements against buckling. With the purpose of obtaining the comprehensive target of minimum deflection and weight under ultimate load, the cross-section and the inner pressure of tensairity girder was optimized in this paper. The Variable Complexity Modeling (VCM) method was used in this paper combining the Kriging approximate method with the Finite Element Analysis (FEA) method, which was implemented by ABAQUS. In the Kriging method, the sample points of the surrogate model were outlined by Design of Experiment (DOE) technique based on Optimal Latin Hypercube. The optimization framework was constructed in iSIGHT with a global optimization method, Multi-Island Genetic Algorithm (MIGA), followed by a local optimization method, Sequential Quadratic Program (SQP). The result of the optimization gives a prominent conceptual design of the tensairity girder, which approves the solution architecture of VCM is feasible and efficient. Furthermore, a useful trend of sensitivity between optimization variables and responses was performed to guide future design. It was proved that the inner pressure is the key parameter to balance the maximum Von Mises stress and deflection on tensairity girder, and the parameters of cross section impact the mass of tensairity girder obviously.

Propulsion System Modeling and Reduction for Conceptual Truss-Braced Wing Aircraft Design

  • Lee, Kyunghoon;Nam, Taewoo;Kang, Shinseong
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.4
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    • pp.651-661
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    • 2017
  • A truss-braced wing (TBW) aircraft has recently received increasing attention due to higher aerodynamic efficiency compared to conventional cantilever wing aircraft. For conceptual TBW aircraft design, we developed a propulsion-and-airframe integrated design environment by replacing a semi-empirical turbofan engine model with a thermodynamic cycle-based one built upon the numerical propulsion system simulation (NPSS). The constructed NPSS model benefitted TBW aircraft design study, as it could handle engine installation effects influencing engine fuel efficiency. The NPSS model also contributed to broadening TBW aircraft design space, for it provided turbofan engine design variables involving a technology factor reflecting progress in propulsion technology. To effectively consolidate the NPSS propulsion model with the TBW airframe model, we devised a rapid, approximate substitute of the NPSS model by reduced-order modeling (ROM) to resolve difficulties in model integration. In addition, we formed an artificial neural network (ANN) that associates engine component attributes evaluated by object-oriented weight analysis of turbine engine (WATE++) with engine design variables to determine engine weight and size, both of which bring together the propulsion and airframe system models. Through propulsion-andairframe design space exploration, we optimized TBW aircraft design for fuel saving and revealed that a simple engine model neglecting engine installation effects may overestimate TBW aircraft performance.

Requirement-Oriented Entity Relationship Modeling

  • Lee, Sang-Won;Shin, Kyung-Shik
    • Journal of Information Technology Applications and Management
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    • v.17 no.3
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    • pp.1-24
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    • 2010
  • Most of enterprises depend on a data modeler during developing their management information systems. In formulating business requirements for information systems, they widely and naturally use the interview method between a data modeler and a field worker. But, the discrepancy between both parties would certainly cause information loss and distortion that lead to let the systems not faithful to real business works. To improve or avoid modeler-dependant data modeling process, many automated data design CASE tools have been introduced. However, since most of traditional CASE tools just support drawing works for conceptual data design, a data modeler could not generate an ERD faithful to real business works and a user could not use them without any knowledge on database. Although some CASE tools supported conceptual data design, they still required too much preliminary database knowledge for a user. Against these traditional CASE tools, we proposed a Requirement-Oriented Entity Relationship Model for automated data design tool, called ROERM. Based on Non-Stop Methodology, ROERM adopts inner systematic modules for complete and sound ERD that is faithful to real field works, where modules are composed of interaction modules with a user, rules of schema operations and sentence translations. In addition to structure design of ROERM, we also devise detailed algorithms and perform an experiment for a case study.

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A Structured Markup Language for the Object-Oriented Representation and Management of Decision Models on the Web (웹상에서의 의사결정모형의 객체지향적 표현과 관리를 위한 구조적 마크업 언어)

  • Kim, Hyoung-Do
    • Asia pacific journal of information systems
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    • v.8 no.2
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    • pp.53-67
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    • 1998
  • The explosive growth of the Web is providing end-users access to ever-increasing volumes of information. The resources of legacy systems and relational databases have also been made available to the Web browser, which has become an essential business tool. Recently, model management on the Internet/Web is also proposed with its conceptual design or prototypical system like DecisionNet and DSS Web. However, they are also suffering from the same symptoms as the Web, Although we can identify the elements of a page with HTML tags and (declare) the relationships among the various document elements, they are semantically opaque to computer systems and have no domain-specific meaning. However, HTML is not extensible, so developers are forced to invent convoluted, non-standard solutions for embedding and parsing data. Extensible Markup Language (XML) is a simplified subset of SGML that has many benefits for folks who want to improve structure, maintainability, searchability, presentation, and other aspects of their document management. This paper proposes a structured markup language for model representation and management on the Web as an XML application. The language is based on a conceptual modeling framework, Object-Oriented Structured Modeling (OOSM), which is an extension of the structured modeling.

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Selecting a Web Portal for Online Shopping: A Conceptual Approach Using Interpretive Structural Modeling

  • Prashar, Sanjeev;Vijay, T. Sai;Parsad, Chandan
    • Asian Journal of Business Environment
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    • v.5 no.4
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    • pp.37-46
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    • 2015
  • Purpose - The present study examines interrelationships among antecedent factors defining consumer behavior in selecting online shopping websites. Research design, data, and methodology - The study identified factors from existing literature and used Interpretive Structural Modeling (ISM) to propose a conceptual approach to explain consumer website selection behavior. Through extensive discussions among industry and academia experts, qualitative assessment of the relationship between various factors was determined. Results - According to the model, eight congregating factors do not converge directly for website selection, rather, they operate following a hierarchy of influence. The ISM and MICMAC analysis reveal that information on a website and website aesthetics play key roles in influencing website selection. However, convenience and the value proposition also play very significant roles. Conclusions - The study's findings can help the e-commerce industry, especially online retailers. The findings can be used to enhance e-retailer ability to attract, communicate, engage, achieve, monitor, and evaluate web traffic and design appropriate strategies. The study's prime contribution is the application of Interpretative Structural Modeling (ISM) to the field of website selection.

Beyond SDLC: Process Modeling and Documentation Using Thinging Machines

  • Al-Fedaghi, Sabah
    • International Journal of Computer Science & Network Security
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    • v.21 no.7
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    • pp.191-204
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    • 2021
  • The software development life cycle (SDLC) is a procedure used to develop a software system that meets both the customer's needs and real-world requirements. The first phase of the SDLC involves creating a conceptual model that represents the involved domain in reality. In requirements engineering, building such a model is considered a bridge to the design and construction phases. However, this type of model can also serve as a basic model for identifying business processes and how these processes are interconnected to achieve the final result. This paper focuses on process modeling in organizations, per se, beyond its application in the SDLC when an organization needs further documentation to meet its growth needs and address regular changes over time. The resultant process documentation is created alongside the daily operations of the business process. The model provides visualization and documentation of processes to assist in defining work patterns, avoiding redundancy, or even designing new processes. In this paper, a proposed diagrammatic representation models each process using one diagram comprising five actions and two types of relations to build three levels of depiction. These levels consist of a static description, events, and the behavior of the modeled process. The viability of a thinging machine is demonstrated by re-modeling some examples from the literature.

Model Multiplicity (UML) Versus Model Singularity in System Requirements and Design

  • Al-Fedaghi, Sabah
    • International Journal of Computer Science & Network Security
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    • v.21 no.4
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    • pp.103-114
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    • 2021
  • A conceptual model can be used to manage complexity in both the design and implementation phases of the system development life cycle. Such a model requires a firm grasp of the abstract principles on which a system is based, as well as an understanding of the high-level nature of the representation of entities and processes. In this context, models can have distinct architectural characteristics. This paper discusses model multiplicity (e.g., unified modeling language [UML]), model singularity (e.g., object-process methodology [OPM], thinging machine [TM]), and a heterogeneous model that involves multiplicity and singularity. The basic idea of model multiplicity is that it is not possible to present all views in a single representation, so a number of models are used, with each model representing a different view. The model singularity approach uses only a single unified model that assimilates its subsystems into one system. This paper is concerned with current approaches, especially in software engineering texts, where multimodal UML is introduced as the general-purpose modeling language (i.e., UML is modeling). In such a situation, we suggest raising the issue of multiplicity versus singularity in modeling. This would foster a basic appreciation of the UML advantages and difficulties that may be faced during modeling, especially in the educational setting. Furthermore, we advocate the claim that a multiplicity of views does not necessitate a multiplicity of models. The model singularity approach can represent multiple views (static, behavior) without resorting to a collection of multiple models with various notations. We present an example of such a model where the static representation is developed first. Then, the dynamic view and behavioral representations are built by incorporating a decomposition strategy interleaved with the notion of time.

Procedural Interface between Freehand Sketch-based Modeling System and Commercial MCAD (프리핸드 스케치 기반 모델링 시스템과 상업용 MCAD의 절차적 인터페이스)

  • Cheon, Sang-Uk;Mun, Du-Hwan;Kim, Byung-Chul;Han, Soon-Hung
    • Korean Journal of Computational Design and Engineering
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    • v.13 no.4
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    • pp.255-264
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    • 2008
  • Research that reconstructs a 3D model from a freehand 2D sketch has gained attention since 1990s, when data integration in the CAD/CAPP/CAM/CNC chain was an important issue. However, 2D sketches in the conceptual design phase have not been integrated with the downstream CAD/CAPP/CAM/CNC chain. In this paper, we present a method to interface a freehand sketch modeling to commercial CAD systems by mapping a sketch modeling history to the macro parametric history. We use an extended ISO10303-112 standard to represent the modeling history in a gestural modeling system and translate sketch files to neutral macro files. Macro parametric translators are used to translate netural macro files to commercial CAD files.

Enhancing Expressiveness of Conceptual Modeling for Bibliographic Relationships - A Reflection on the FRBR Entity-Relationship Model - (공통기술표현포맷에 기반한 다매체자료의 검색효율 향상에 관한 연구)

  • Choi, Yun-Seon;Renear, Allen
    • Journal of the Korean Society for information Management
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    • v.23 no.4 s.62
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    • pp.5-15
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    • 2006
  • The Functional Requirements for Bibliographic Records (FRBR) is a 'conceptual model of the bibliographic universe' developed by the International Federation of Library Associations and Institutions (IFLA). Although some studies have suggested improvements in FRBR, and others explore alternative approaches, less attention has been paid to analyzing the internal coherence and consistency of the FRBR view as presented not only in the FRBR entity-relationship model and text of the FRBR document, but also in the related explanations and presentations of FRBR expositors. Our investigations have noted some interesting discrepancies between the general FRBR approach as presented in various expository documents and the specific account presented in the FRBR ER model and the FRBR document. We see that in one case these discrepancies can be easily remedied by adding additional modeling constructs and assertions, but in another case (the supposed 'inheritance' of attributes across the Group 1 entities), there is a substantial difficulty in maintaining a consistent model. We discuss several alternative approaches to enhancing the expressiveness of FRBR in order remedy this problem. We note that none is entirely satisfactory.

An Analysis on the Process of Conceptual Understanding of Fifth Grade Elementary School Students about the Division of Decimal with Base-Ten Blocks (십진블록을 활용한 소수의 나눗셈 지도에서 초등학교 5학년 학생들의 개념적 이해 과정 분석)

  • Pang, Jeong-Suk;Kim, Soo-Jeong
    • Journal of Educational Research in Mathematics
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    • v.17 no.3
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    • pp.233-251
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    • 2007
  • The purpose of this study was to propose instructional methods using base-ten blocks in teaching the division of decimal for 5th grade students by analyzing the process of their conceptual comprehension. The students in this study were found to understand the two main meanings of the division of decimal, distribution and area, by modeling them with base-ten blocks. They were able to identify the algorithm through the use of base-ten blocks and to understand the principle of calculations by connecting the manipulative activities to each stage of algorithm. The students were also able to determine using base-ten blocks whether the results of division of decimal might be reasonable. This study suggests that the appropriate use of base-ten blocks promotes the conceptual understanding of the division of decimal.

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