• 제어로봇시스템학회논문지
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• 제9권9호
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• pp.736-744
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• 2003

The GPS attitude output or carrier phase observables can be effectively utilized to compensate the attitude error of the strapdown inertial navigation system. However, when the integer ambiguity is not correctly resolved and/or a cycle slip occurs, an erroneous GPS output can be obtained. If the erroneous GPS information is directly applied to the AGPS/INS integration system, the performance of the system can be rapidly degraded. This paper proposes an AGPS/INS integration system using the triple difference carrier phase observables. The proposed integration system contains a cycle slip detection algorithm, in which inertial information is combined. Computer simulations and van test were performed to verify the proposed integration system. The results show that the proposed system gives an accurate and reliable navigation solution even when the integer ambiguity is not correct and the cycle slip occurs.

• International Journal of Control, Automation, and Systems
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• 제1권4호
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• pp.444-452
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• 2003

An integration system with multi-measurement sets can be realized via combined application of a centralized and federated Kalman filter. It is difficult for the centralized Kalman filter to remove a failed sensor in comparison with the federated Kalman filter. All varieties of Kalman filters monitor innovation sequence (residual) for detection and isolation of a failed sensor. The innovation sequence, which is selected as an indicator of real time estimation error plays an important role in adaptive mechanism design. In this study, the centralized Kalman filter with adaptive measurement fusion is introduced by means of innovation sequence. The objectives of adaptive measurement fusion are automatic isolation and recovery of some sensor failures as well as inherent monitoring capability. The proposed adaptive filter is applied to the GPS/SDINS integration system with an additional sensor. Simulation studies attest that the proposed adaptive scheme is effective for isolation and recovery of immediate sensor failures.

• 기술혁신연구
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• 제6권2호
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• pp.80-100
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• 1998

The application of computers and information technologies progressed with remarkable pace has paved the way for technological innovation toward the efficient integration of various functions in a manufacturing system. Actually it is observed that the greater part of manufacturing companies already initiated significant efforts to integrate information systems and attained the level of integration to some extent. The purpose of this paper is to clarify the strategic direction that manufacturing firms are pursuing through integrating information systems. Using the extensive data gathered from Japanese manufacturers, it is attempted to find the differences in competitive priorities and action programmes between the companies with high and low-level system integration. Our empirical data reveals that the manufacturers with highly integrated system are focusing their competitive capabilities on the rapid design change and new product introduction, and accordingly they place a greater emphasis on the action programmes related to design, process and quality improvement. As a conclusion, highly integrated firms tend to pursue new product development strategy more intensively, thereby they want to be a preemptor in the new market through exploiting technological advantages of integrated manufacturing system.

• 제어로봇시스템학회논문지
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• 제16권7호
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• pp.720-725
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• 2010

In AGPS method, user position can be obtained even in the shadow region by improving signal sensitivity. A hybrid long integration scheme employing both coherent and non-coherent integration method is commonly used in AGPS receivers. Because coherent loss increases as residual frequency become large, residual frequency should be minimized to maximize coherent integration gain. This paper presents performance analysis of residual frequency estimator using FFT in fine-time assistance AGPS method. Considering the hardware complexity and the estimation accuracy, optimal length of FFT is proposed for GPS L1 C/A signal. Signal sensitivity for estimating the residual frequency is also analysed. By field experimental results, it is found that the residual frequency can be successfully estimated using 1 second snap-shot data when GPS signal strength is larger than -150 dBm and its RMS error is 3Hz.

• 제어로봇시스템학회논문지
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• 제22권11호
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• pp.937-943
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• 2016

Vertical velocity is critical in many areas, such as the control of unmanned aerial vehicles, fall detection, and virtual reality. Conventionally, the integration of GPS (Global Positioning System) with an IMU (Inertial Measurement Unit) was popular for the estimation of vertical components. However, GPS cannot work well indoors and, more importantly, has low accuracy in the vertical direction. In order to overcome these issues, IMU-barometer integration has been suggested instead of IMU-GPS integration. This paper proposes a new complementary filter for the estimation of vertical velocity based on IMU-barometer integration. The proposed complementary filter is designed to minimize drift error in the estimated velocity by adding PID control in addition to a zero velocity update technique.

• 전기학회논문지
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• 제65권3호
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• pp.457-462
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• 2016

In this paper, we consider the stability of time-delayed linear systems. To derive an LMI form of result, the integral inequality is essential, and Jensen's integral inequality was the best in the last two decades until Seuret's integral inequality is appeared recently. However, these two are proportional to the inverse of integration interval, so another integral inequality is needed to make it in the form of LMI. In this paper, we derive an integral inequality which is proportional to the integration interval which can be easily converted into LMI form without any other inequality. Also, it is shown that Seuret's integral inequality is a special case of our result. Next, based on this new integral inequality, we derive a stability condition in the form of LMI. Finally, we show, by well-known two examples, that our result is less conservative than the recent results.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2005년도 공동추계학술대회
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• pp.295-303
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• 2005

Semantic Web and its related technologies have been opening the era of information sharing via Web. In the meantime, there are several huddles to overcome toward the new era and one of the major huddles is information integration issue unless we build and use a single unified but huge ontology which address everything in the world. Particularly in e-business area, information integration problem must be a great concern in search and comparison of products from various internet shopping sites and e-marketplaces. To overcome such an information integration problem, we propose an ontology driven mapping algorithm between heterogeneous product classification and description frameworks. We also perform comparative evaluation of the proposed mapping algorithm against a well-known ontology mapping tool, PROMPT.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.497-502
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• 2005

Needs of automation and computerization in the construction industry has been recognized but the implementation of e-business solutions with project management systems has not been fully explored. In order to cope with different management practices in home office and project sites, integration of two popular systems, Enterprise Resource Planning (ERP) and Project Management System (PMS) is essential. The objective of this study is to find ways to functionally and systematically integrate ERP and PMS. With the integration of ERP and PMS, a project will be managed much more efficiently and effectively. It is expected that this study will benefit system integrators and help them to understand construction management processes and integrate the solutions with minimized programming work.

• Journal of Information Technology Applications and Management
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• 제10권3호
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• pp.55-74
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• 2003

Due to the evolution of computer systems and the proliferation of Internet, numerous information resources have been constructed. The deluge of information makes the need to integrate information, which are distributed on the internet and are handled in heterogeneous systems. Recently, most of the XML -based information integration systems use XML DTD(Document Type Definition) for describing integrated global schema. However, DTD has some limitations in modeling local information resources such as datatypes. Although W3C's XML Schema is more flexible and powerful than XML DTD in specifying integrated global schema, it has more complex problems in resolving conflicts than using DTD. In this paper, we provide a taxonomy of conflict problems in integration information resources using XML Schema, and propose conflict resolution mechanism using XQuery.

• 시스템엔지니어링학술지
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• 제7권1호
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• pp.43-51
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• 2011

SE generally defines approaching ways of conducting identification, verification and integration of an optimized product and process solution to meet customer's needs by leveraging organizational competency in engineering and management. To successfully develop a new product under mass production contract, it is important to efficiently carry out the program by ensuring that three major competencies are secured; core technology, system integration, and program management. For successful implementation of tasks in the three areas, systematic execution is called for, which requires identifying risk factors in advance. In particular, comprehensive risk management role and responsibility is required for program management. Success of a development program is determined by complex elements of human resources, organization culture, and overall competency of an organization in technology and program management, including capability of the program manager. In this paper, a risk management solution is suggested to lead a program to success with a more efficient way through actual risk management by the concept of SE around the above three areas.