• Journal of Institute of Control, Robotics and Systems
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• v.6 no.10
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• pp.928-935
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• 2000

In order to improve the performance of a GPS/DR integration system, the error sources of DR sensors should be modeled accurately, This results in the increases in the dimension of the integration filter and, consequently, computational load becomes large. To reduce the computational load, suggested in this paper is a decoupled GPS/DR integration scheme that consists of two cascaded Kalman filters. The GPS velocity output is used in the first filter to calibrate the DR sensor and to fix the velocity as well. The velocity from the first filter is fed to the second filter where the position is corrected using the GPS position output. Experimental results show that the proposed integration scheme has positioning performance comparable to the conventional coupled one, while its computation is reduced to about 2/3.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.785-791
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• 2008

Ultra-tightly coupled GPS/INS integration has been reported to show better navigation performance than that of other integration methods such as loosely coupled and tightly coupled integration. This paper uses the particle filter for ultra-tightly coupled GPS/INS integration and analyzes the navigation performance according to vehicle trajectory and the number of particles. The navigation performance of particle filter is compared with those of EKF and UKF.

• Journal of Mechanical Science and Technology
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• v.17 no.4
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• pp.538-544
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• 2003

Although many methodologies exist for determining the constrained equations of motion, most of these methods depend on numerical approaches such as the Lagrange multiplier's method expressed in differential/algebraic systems. In 1992, Udwadia and Kalaba proposed explicit equations of motion for constrained systems based on Gauss's principle and elementary linear algebra without any multipliers or complicated intermediate processes. The generalized inverse method was the first work to present explicit equations of motion for constrained systems. However, numerical integration results of the equation of motion gradually veer away from the constraint equations with time. Thus, an objective of this study is to provide a numerical integration scheme, which modifies the generalized inverse method to reduce the errors. The modified equations of motion for constrained systems include the position constraints of index 3 systems and their first derivatives with respect to time in addition to their second derivatives with respect to time. The effectiveness of the proposed method is illustrated by numerical examples.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.974-977
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• 2003

The GPS/INS integration system navigation can provide improved navigation performance and has been widely used as a main navigation system for military and commercial vehicles. When two navigation systems are tightly coupled and the structure is complicated, a fault in either the GPS or the INS can lead to a disastrous failure of the whole integration system. This paper proposes a real-time fault detection method for an AGPS/INS integration system. The proposed fault detection method comprises a BIT and a fault detection algorithm based on chi-square test. It is implemented by real-time software modules to apply the AGPS/INS integration system and van test is carried out to evaluate its performance.

• Journal of Korea Multimedia Society
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• v.19 no.7
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• pp.1188-1196
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• 2016

Integration systems help users consume services more effectively. However, previous integration systems can only enable predefined service cooperation to satisfy users, which is difficult to achieve user-centric service composition in dynamic environments. Therefore, in this paper, a dynamic service integration system is proposed to automatically combine services based on usage history. With this system, services can be dynamically composed to meet users' needs and information can be flexibly transited among heterogeneous services.

• The Journal of Society for e-Business Studies
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• v.9 no.1
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• pp.39-59
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• 2004

E-business automates overall activities in a company and allows distributed systems to communicate their information. The automation and information sharing improves its productivity and responsiveness. B2B workflow systems progress their business processes electronically and help the companies to monitor their execution and administrate the processes. This research analyzes the technologies and standards for B2B workflow integration, and proposes three approaches to implement effectively workflow integration. We analyze several existing workflow standards and business process definition languages, and compare their structures and features. And we examine the messaging technologies and architectures to implement business integration. Finally we extract a reference model for B2B workflow integration, and propose three types of workflow integration and implementation designs. This research helps companies to understand the workflow standards and the messaging technologies for B2B workflow integration, and to implement workflow integration systems that are suitable for their e-business environments.

• Journal of Korean Society for Quality Management
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• v.29 no.4
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• pp.133-152
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• 2001

In order to have competitive advantage for the business firms, companies need to raise competitiveness through the effective distribution and practical use of management resources along with strategic management of integration of existing management systems such as quality and business environment. Upon resulting of questionnaires to expert group, it is definite to have an integration of quality and environment system for the better efficiency of firms, and also recommended to have either a mixture of two systems or build up new integration system through uniform of two systems. The effects of the integrated system can be summarized as an increase of company image, efficiency of system operation, simplification of system management, synergy effects on the integration.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.3
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• pp.163-172
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• 2012

Regarding project management, many organizations have developed and distributed general project management knowledge systems, and application fields use the knowledge systems to apply the process suitable for characteristics of a project. This study suggests project management process models to apply to system integration projects. This system integration project management process model is composed of six top processes of initiation, preparation for contract, planning, implementation management, coordination and control, and termination and transfer. The five processes are re-divided into 25 bottom processes. These processes are expressed as input, control, output, and mechanism by using the IDEF0 model. For this model development, it has chosen the items which constituted a process through a questionnaire of experts.

• Journal of Ship and Ocean Technology
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• v.9 no.3
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• pp.33-42
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• 2005

As the networks connect the world, enterprises tend to move manufacturing activities into virtual spaces. Since different software applications use different data terminology, it becomes a problem to interoperate, interchange, and manage electronic data among heterogeneous systems. It is said that approximately one billion dollar has been being spent yearly in USA for product data exchange and interoperability. As commercial CAD systems have brought in the concept of design feature for the sake of interoperability, terminologies of design features need to be harmonized. In order to define design feature terminology for integration, knowledge about feature definitions of different CAD systems should be considered. STEP standard have attempted to solve this problem, but it defines only syntactic data representation so that semantic data integration is not possible. This paper proposes a methodology for integrating modeling features of CAD systems. We utilize the ontology concept to build a data model of design features which can be a semantic standard of feature definitions of CAD systems. Using feature ontology, we implement an integrated virtual database and a simple system which searches and edits design features in a semantic way.

• Structural Engineering and Mechanics
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• v.9 no.6
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• pp.557-568
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• 2000

As time-variant reliability approaches become increasingly used for service life prediction of the aging infrastructure, the demand for computer solution methods continues to increase. Effcient computer techniques have become well established for the reliability analysis of structural systems. Thus far, however, this is largely limited to time-invariant reliability problems. Therefore, the requirements for time-variant reliability prediction of deteriorating structural systems under time-variant loads have remained incomplete. This study presents a computer program for $\underline{REL}$iability of $\underline{T}$ime-Variant $\underline{SYS}$tems, RELTSYS. This program uses a combined technique of adaptive importance sampling, numerical integration, and fault tree analysis to compute time-variant reliabilities of individual components and systems. Time-invariant quantities are generated using Monte Carlo simulation, whereas time-variant quantities are evaluated using numerical integration. Load distribution and post-failure redistribution are considered using fault tree analysis. The strengths and limitations of RELTSYS are presented via a numerical example.