• Journal of the Korean Society of Systems Engineering
• /
• v.14 no.2
• /
• pp.8-15
• /
• 2018

In traditional Document Based Configuration Management(DBCM) environment, changes in a system's configurations are hard to be reflected to existing engineering documents. This nature of DBCM triggers unconformities of system configurations which could become great risks. Model-based Configuration Management(MBCM) has been introduced to solve the problem of DBCM by managing system's configurations through an unified model. Therefore, it is important to model engineering documents in a general modeling language, down to low-level information items to develop traceability and flexibility of a system's engineering information. So, in the research, to explore the possibility of Model-based Approach(MBA) in the field of configuration management, a development of a systems requirement document model using SysML based Views & Viewpoints concept has been studied.

• Journal of the Korean Society for Railway
• /
• v.6 no.1
• /
• pp.1-9
• /
• 2003

This article proposes an integrated systems engineering and safety analysis model for safety-critical systems development. A methodology in system design for safety is considered during the early phase of the development life cycle of systems engineering process. The evolution of the design automation technology has enabled engineers to perform the model-based systems engineering. A Computer-Aided Systems Engineering(CASE) tool, CORE, is utilized to integrate the systems engineering model with a system safety analysis model. The results of the functional analysis phase can drive the analysis of the system safety. An example of Communications-Based Train Control(CBTC) system for an Automated Guided Transit(AGT) system demonstrated an application of the integrated model.

• Journal of the Korean Society of Systems Engineering
• /
• v.8 no.1
• /
• pp.29-39
• /
• 2012

The conventional systems engineering has been performed mainly based on documentation artifacts. Although the Document-Based Systems Engineering has played a very important role in developing and deploying systems, it is difficult for systems engineers to build, to clarify, and to reuse the operational, functional and physical views of the System of Interest (SOI) efficiently. An information-age approach to this problem is the Model-Based Systems Engineering which has been emerging as a very productive solution for stakeholders to define, and understand the desired systems easily, to communicate and collaborate efficiently among each other, and also to verify and validate the systems solutions effectively. This paper proposes a set of MBSE process, methods, and models for use during the systems analysis and design phase of the naval combat system development. An example application of the proposed approach was exercised and a set of artifacts was generated for an export combat system project to demonstrate its effectiveness.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2003.09a
• /
• pp.443-446
• /
• 2003

Conventional disturbance rejection methods have to derive the inverse model of a system. However, the inverse model of n nonholonomic system is not unique, because an inverse it changes depending on initial conditions and desired values. A kind of internal model control (IMC) using feedback error learning is discussed for the motion control of nonholonomic mobile robots in this paper, The present method is different from a conventional IMC whose control system consists of an inverse model, a direct model and a filter. The present disturbance rejection method need not use a direct model, where the remaining two elements are composed of the same inverse model based on neural networks.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.8
• /
• pp.689-696
• /
• 2001

Large-scale Multi-disciplinary Systems(LMS) such as transportation, aerospace, defense etc. are complex systems in which there are many subsystems, interfaces, functions and demanding performance requirements. Because many contractors participate in the development, it is necessary to apply methods of sharing common objectives and communicating design status effectively among all of the stakeholders. The processes and methods of systems engineering which includes system requirement analysis; functional analysis; architecting; system analysis; interface control; and system specification development provide a success-oriented disciplined approach to the project. This paper shows not only the methodology and the results of model-based systems engineering to Automated Guided Transit(AGT) system as one of LMS systems, but also propose the extension of the model-based tool to help manage a project by linking WBS (Work Breakdown Structure), work organization, and PBS (Product Breakdown Structure). In performing the model-based functional analysis, the focus was on the operation concept of an example rail system at the top-level and the propulsion/braking function, a key function of the modern automated rail system. The model-based behavior analysis approach that applies a discrete-event simulation method facilitates the system functional definition and the test and verification activities. The first application of computer-aided tool, RDD-100, in the railway industry demonstrates the capability to model product design knowledge and decisions concerning key issues such as the rationale for architecting the top-level system. The model-based product design knowledge will be essential in integrating the follow-on life-cycle phase activities. production through operation and support, over the life of the AGT system. Additionally, when a new generation train system is required, the reuse of the model-based database can increase the system design productivity and effectiveness significantly.

• Journal of the Korean Society of Systems Engineering
• /
• v.12 no.2
• /
• pp.59-67
• /
• 2016

Recently, the increased complexity of systems has made systems engineering necessary. It is very useful for system designers to understand the whole context of the concerned system based on systems engineering. A system model can be used to describe the outcome of a system design. A system model describes the system from the viewpoint of the stakeholder's needs using the mutually exclusive and collectively exhaustive principle. A system model can be used to smoothly design a large and complicated system based on the systems engineering development process. Many companies and countries are attempting to apply model-based systems engineering, and the significance of the system model quality is increasing as system models are referenced during system development. In this paper, we propose a quality assessment method for ontology which is one of system models by focusing on the system development process. First, in this process, a system developer should explicitly show the relationship between viewpoints. Then, the system developer should select dependent rather than independent viewpoints. With dependent viewpoints, each viewpoint used to describe the system has some logical relationship. The set of viewpoints makes it possible to show, not only tangible and physical system parts, but also conceptual system parts. In this paper, we develop an ontological system model of a Japanese weather observation system. By comparing some ontological system models, we verify the effectiveness of explicitly describing the relationships between viewpoints and select dependent viewpoints.

• Journal of the Korean Society of Systems Engineering
• /
• v.13 no.1
• /
• pp.51-56
• /
• 2017

This paper presents a requirement development process using the model based systems engineering design process to the developments of the missile Seeker. SysML Model and requirement analysis templates were used as the specific execution method for applying the system engineering process. This paper will present a process for deriving the technical requirements and derived requirements using them.

• Journal of Information Processing Systems
• /
• v.8 no.2
• /
• pp.213-240
• /
• 2012

Safety critical systems, real time systems, and event-based systems have a complex set of events and their own interdependency, which makes them difficult to test ma Safety critic Safety critical systems, real time systems, and event-based systems have a complex set of events and their own interdependency, which makes them difficult to test manually. In order to cut down on costs, save time, and increase reliability, the model based testing approach is the best solution. Such an approach does not require applications or codes prior to generating test cases, so it leads to the early detection of faults, which helps in reducing the development time. Several model-based testing approaches have used different UML models but very few works have been reported to show the generation of test cases that use events. Test cases that use events are an apt choice for these types of systems. However, these works have considered events that happen at a user interface level in a system while other events that happen in a system are not considered. Such works have limited applications in testing the GUI of a system. In this paper, a novel model-based testing approach is presented using business events, state events, and control events that have been captured directly from requirement specifications. The proposed approach documents events in event templates and then builds an event-flow model and a fault model for a system. Test coverage criterion and an algorithm are designed using these models to generate event sequence based test scenarios and test cases. Unlike other event based approaches, our approach is able to detect the proposed faults in a system. A prototype tool is developed to automate and evaluate the applicability of the entire process. Results have shown that the proposed approach and supportive tool is able to successfully derive test scenarios and test cases from the requirement specifications of safety critical systems, real time systems, and event based systems.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2004.10a
• /
• pp.211-216
• /
• 2004

In this thesis, we present the Takagi-Sugeno-Kang (TSK) fuzzy model based adaptive controller and adaptive identification for a general class of uncertain nonlinear dynamic systems. We use an estimated model for the unknown plant model and use this model for designing the controller. The hybrid adaptive control combined direct and indirect adaptive control based on TSK fuzzy model is constructed. The direct adaptive law can be showed by ignoring the identification errors and fails to achieve parameter convergence. Thus, we propose an TSK fuzzy model based hybrid adaptive (HA) law combined of the tracking error and the model ins error to adjust the parameters. Using a Lyapunov synthesis approach, the proposed hybrid adaptive control is proved. The hybrid adaptive law (HA) is better than the direct adaptive (DA) method without identifying the model ins error in terms of faster and improved tracking and parameter convergence. In order to show the applicability of the proposed method, it is applied to the inverted pendulum system and the performance is verified by some simulation results.

• Journal of the Korean Society of Systems Engineering
• /
• v.5 no.2
• /
• pp.57-62
• /
• 2009

An embedded system is a computer system designed to perform one or a few dedicated functions often with real-time computing constraints. A traditional design process of embedded systems is the development of document-centric approach, and it is difficult to develop an embedded system efficiently because communication between teams or steps is not smooth. So the Model Based Design Process are applied to the development of embedded systems. This paper will compare the Model Based Design Process and the traditional design process, and introduce example of development of vehicle device applied the Model Based Design Process.