• The KIPS Transactions:PartD
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• v.10D no.7
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• pp.1155-1160
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• 2003

This paper applies RBAC policy for solving on the security problems when it will be operated several business on the distributed environments and designed Extended RBAC (ERBAC) model that it is possible to manage security systems on the distributed environments. The designed ERBAC model is based on RBAC96 model due to Sandu et al and added role delegations. Therefor, the designed ERBAC model have the advantage of the following . it can be processed of business without interrupts and implemented server system without modifying its source code, high migration, easy and simple of secure managing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.9
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• pp.1680-1691
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• 1994

We propose an extended hypertext data model based on object oriented paradigm that can easily the real world and semantics. We use the BNF notation to formalize the model. In our model, We introduce conceptional navigation by associating semantics on links and drive intelligent navigation using weights on links to alleviate user disorientation problem which is currently somewhat vague. We functionally classify the hypertext node into three types:Indexing node, Content node, Extract node and likewise classify the link into Alink type, Rlink type, Slink type. We believe that the typed node and typed link approach accommodate efficient query/search in hypertext.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.125-127
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• 2003

The Conventional time-domain simulation of transient stability requires iterative calculation procedures to consider the saliency of generator. Recently, a non-iterative algorithm has successfully developed to take into account the generator saliency exactly with the use of $E_q'$-model. This study proposes an extended non-iterative algorithm by adopting the two-axis generator model. Given internal voltages and rotor angles of the generators, network voltages and generator currents can be directly calculated by solving a linear algebraic equation, which enables us to reduce the computation time remarkably.

• Journal of Computing Science and Engineering
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• v.2 no.1
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• pp.26-43
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• 2008

We propose a new query expansion method in the extended Boolean model that improves precision without degrading recall. For improving precision, our method promotes the ranks of documents having more query terms since users typically prefer such documents. The proposed method consists of the following three steps: (1) expanding the query by adding new terms related to each term of the query, (2) further expanding the query by adding augmented terms, which are conjunctions of the terms, (3) assigning a weight on each term so that augmented terms have higher weights than the other terms. We conduct extensive experiments to show the effectiveness of the proposed method. The experimental results show that the proposed method improves precision by up to 102% for the TREC-6 data compared with the existing query expansion method using a thesaurus proposed by Kwon et al.

• The Journal of Information Technology
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• v.4 no.4
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• pp.15-24
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• 2001

In current role-based systems, security officers handle assignments of users to roles. This may increase management efforts in a distributed environment because of the continuous involvement from security officers. The role-based delegation provides a means for implementing RBAC in a distributed environment. The basic idea of a role-based delegation is that users themselves may delegate role authorities to other users to carry out some functions on behalf of the former. This paper presents a user-level delegation model, which is based on Extended Role-Based Access Control(ERBAC). ERBAC provides finer grained access control on the base of subject and object level than RBAC model.

• 대한공업교육학회지
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• v.34 no.2
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• pp.396-410
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• 2009

The goal of this work is to present an advanced method of an estimation of the Modeling Uncertainties coming up in industrial rigid robot's manipulator and actuators. First, with the given physical robot model, the motion equation was derived. Considering a fictitious model, a new extended motion equation is developed. Based on this extended model, an observer and observer bank are designed for the estimation of modeling uncertainties which are involving the effects of gravity, friction, mass unbalance, and Coriolis which show the nonlinear characteristics in operation states.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.1
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• pp.129-137
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• 2017

In this paper, we propose a digital controller design methodology for an LLC resonant converter which has been widely used due to the advantages of low switching loss and high efficiency. We establish a mathematical model of an LLC resonant converter using the extended describing function concept and propose a controller design method based on the Ziegler Nichols control parameter tuning criteria. The voltage controller of an LLC resonant converter is designed based on the derived small signal model and the performance of the controller is verified by MATLAB simulations. The validity and the control performance of the designed voltage controller for the LLC resonant converter is analyzed through some simulations for the case of load variations and circuit modeling errors.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.9
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• pp.931-938
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• 2008

In this paper, a novel localization algorithm robust to the unmodeled systematic odometry errors is proposed for low-cost non-holonomic mobile robots. It is well known that the most pose estimators using odometry measurements cannot avoid the performance degradation due to the dead-reckoning of systematic odometry errors. As a remedy for this problem, we tty to reflect the wheelbase error in the robot motion model as a parametric uncertainty. Applying the Krein space estimation theory for the discrete-time uncertain nonlinear motion model results in the extended robust Kalman filter. This idea comes from the fact that systematic odometry errors might be regarded as the parametric uncertainties satisfying the sum quadratic constrains (SQCs). The advantage of the proposed methodology is that it has the same recursive structure as the conventional extended Kalman filter, which makes our scheme suitable for real-time applications. Moreover, it guarantees the satisfactoty localization performance even in the presence of wheelbase uncertainty which is hard to model or estimate but often arises from real driving environments. The computer simulations will be given to demonstrate the robustness of the suggested localization algorithm.

• Progress in Superconductivity and Cryogenics
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• v.17 no.4
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• pp.16-20
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• 2015

We investigated optical properties of an electron-doped copper oxide high temperature superconductor, $Pr_{0.85}LaCe_{0.15}CuO_4$ (PLCCO) single crystal. We obtained the optical conductivity from measured reflectance at various temperatures. We found our data contained c-axis longitudinal optical (LO) phonon modes due to miscut and intrinsic lattice distortion. We applied an extended Drude model to study the correlations between charge carriers in the system. The LO phonons appear as strong sharp peaks in the optical scattering rate. We tried to remove the LO phonon modes by using the energy loss function, which also shows the LO phonons as peaks, and could not remove them completely. We extracted the electron-boson spectral density function using a generalized Allen's formula. We observed that the resulting electron-boson density show similar temperature dependence as hole-doped cuprates.

• Journal of Internet Computing and Services
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• v.19 no.2
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• pp.27-32
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• 2018

In industries that are operating various enterprise systems, new systems are integrated and operated in accordance with each period. In particular, when a new system is to be integrated, one of the major considerations is the single sign-on part for integrating and operating the authentication. To implement this authority system using role-based access control method, an extension method for access control method is needed. Therefore, in this paper, we design an extended role-based access control model for interworking with legacy authority system and provide its APIs. The extended role-based access control model is a model in which external authority information, which holds authority information in the authority information, is added. And we describe operations that the REST Web APIs are based on these models. In this paper, the method is described in the back-end APIs and can be implemented as an operation of an extended role-based access control system based on the method.