• 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.

• Interaction and multiscale mechanics
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• 제6권2호
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• pp.107-125
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• 2013

A strain smoothing meshfree formulation with stabilized conforming nodal integration is presented for modeling the consolidation process in saturated porous media. In the present method, nodal strain smoothing is consistently introduced into the meshfree approximation of strain and pore pressure gradient variables associated with the saturated porous media. Meanwhile, in order to achieve a consistent numerical implementation, a smoothing approximation of the meshfree shape function within a nodal representative domain is also proposed in the stiffness construction. The resulting discrete system of equations is all expressed in smoothed nodal measures that are very efficient for numerical evaluation. Subsequently the space-time fully discrete equations are further established by the generalized trapezoidal rule for time integration. The effectiveness of the proposed meshfree consolidation analysis method is systematically illustrated by several benchmark problems.

• Structural Engineering and Mechanics
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• 제55권4호
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• pp.815-837
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• 2015

A new family of structure-dependent integration methods is developed to enhance with desired numerical damping. This family method preserves the most important advantage of the structure-dependent integration method, which can integrate unconditional stability and explicit formulation together, and thus it is very computationally efficient. In addition, its numerical damping can be continuously controlled with a parameter. Consequently, it is best suited to solving an inertia-type problem, where the unimportant high frequency responses can be suppressed or even eliminated by the favorable numerical damping while the low frequency modes can be very accurately integrated.

• Kyungpook Mathematical Journal
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• 제64권2호
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• pp.353-369
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• 2024

In this study, we investigate the unknown time-dependent heat source function in inverse problems. We consider three general nonlocal conditions; two classical boundary conditions and one nonlocal over-determination, condition, these genereate six different cases. The finite integration method (FIM), based on numerical integration, has been adapted to solve PDEs, and we use it to discretize the spatial domain; we use backward differences for the time variable. Since the inverse problem is ill-posed with instability, we apply regularization to reduce the instability. We use the first-order Tikhonov's regularization together with the minimization process to solve the inverse source problem. Test examples in all six cases are presented in order to illustrate the accuracy and stability of the numerical solutions.

• Structural Engineering and Mechanics
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• 제28권5호
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• pp.587-601
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• 2008

In this study, a numerical procedure based on the finite element method for materially and geometrically nonlinear analysis of reinforced and prestressed concrete slender columns with arbitrary section subjected to combined biaxial bending and axial load is developed. In order to overcome the low computer efficiency of the conventional section integration method in which the reinforced concrete section is divided into a large number of small areas, an efficient section integration method is used to determine the section tangent stiffness. In this method, the arbitrary shaped cross section is divided into several concrete trapezoids according to boundary vertices, and the contribution of each trapezoid to section stiffness is determined by integrating directly the trapezoid. The space frame flexural theory is utilized to derive the element tangent stiffness matrix. The nonlinear full-range member response is traced by an updated normal plane arc-length solution method. The analytical results agree well with the experimental ones.

• 유통과학연구
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• 제11권9호
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• pp.25-29
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• 2013

Purpose - This study aimed to examine how the integration of IT systems was applied in the merger and acquisition (M&A) process in a Korean retail industry, based on the conceptual framework of a combination of related, existing literature. Research design, data, methodology - We employed the case study method, which involved literature reviews and interviews. We conducted a documentary survey and interviews regarding the M&A case for company A. Results - Company A had an integration strategy and plan with IT expertise before it began integrating both IT systems in D-Day. The IT integration of both systems was completed efficiently and effectively. Company A utilized not just one but all integration options, which was done in stages and according to situation. Conclusions - Companies should develop an integration strategy and have a clear integration plan with IT expertise in order to achieve successful integration. Companies trying to integrate IT systems during an M&A process can utilize all integration options in consideration of their business context and IT system conditions.

• 제어로봇시스템학회논문지
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• 제7권3호
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• pp.269-275
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• 2001

In land navigation applications, two kinds of GPS/DR integration schemes are commonly used; the loosely-coupled integration scheme and the tightly-coupled one. The loosely-coupled integration filter has a simple structure and is easy to implement. When the number of visible satellites is insufficient, however, it cannot calibrate the errors of the DR sensors. On the contrary the tigthly-coupled integration filter can sup-press the growth of the error in the DR output even when the visibility is poor. However, it has larger com-putation load due to the state dimension and is inconsistent because of the variation in the measurement dimension. This paper presents a GPS/DR integration scheme with dual integration mode. During when the number of visible satellites is sufficient, the proposed scheme operates in a loosely-coupled integration mode. When the visibility becomes poor, it is switched into a tightly-coupled integration mode. Consequently, the pro-posed scheme can calibrate the DR sensors even when the visibility is poor. In addition, its computation time remains constant even if the number of visible satellites increases. Field experiment results show that the performance of the proposed integration method is almost similar to that of the tightly-coupled one.

• 한국수학교육학회지시리즈A:수학교육
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• 제37권1호
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• pp.101-114
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• 1998

In this thesis, We tried to introduce definite integration to the curriculum of high school mathematics with numerical integration, which had been introduced with quadrature method. For this purpose, We used new experimental mathematics approaches, so-called investigation and examination. In chapter II, We examined how much computers had been used in teaching mathematics. In chapter III, We presented the theoretical background of approximation integration within numerical integration. In chapter IV, We studied and compared various methods of numerical integration, and examined the relation between curvature of a curved line and numerical integration. In order to study more easily, We used some of computer programs. We hope that this thesis will be a turning point in developing new teaching methods and improving curriculum of mathematics in high school.

• 농촌계획
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• 제12권4호
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• pp.53-61
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• 2006

Rural amenity resources consist of natural, cultural and social resources. Some of resources have been surveyed in other institutes and organizations and information system about these resources has been constructed. Integrating with information of existing system or database is helpful to produce useful rural amenity resources information to users. This integration of distributed information is based on semantic integration. In this paper, we used ontology for semantic integration and introduced the method of external information integration using ontology. We designed ontology table to represent ontology in database and integrated distributed information using ontology. To examine the improvement of information service efficiency and the applicability, rural amenity resources information and tourist attraction information database were constructed and integrated. Also, the information service efficiency with information integration was evaluated using recall ratio and compared to the information service efficiency without information integration.

• 산업공학
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• 제11권3호
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• pp.41-53
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• 1998

Several performance measurement systems have been proposed and are currently being used in many organizations. However, no performance measurement system has presented a mechanism for integrating all of the information of performance measures in a way that considers the relationships between them. This paper proposes the performance information integration method (PIIM) which synthesizes all useful information of performance measures with consideration of the relationships and generates a single, global, organizational performance score. The PIIM showed good performance in the implementation in one long-term care facility. This paper provides performance measurement systems with an integration mechanism for multiple performance measures.