• 한국수학교육학회지시리즈B:순수및응용수학
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• 제16권3호
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• pp.307-314
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• 2009

The purpose of this paper is to establish a strong convergence of an implicit iteration process with errors to a common fixed point for a finite family of continuous strongly pseudocontractive mappings. The results presented in this paper extend and improve the corresponding results of References [2, 6, 11-12].

• 대한수학회논문집
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• 제23권1호
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• pp.111-124
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• 2008

In this paper, we give some fixed point theorems on fuzzy metric spaces with an implicit relation. Our results extend and generalize some fixed point theorems on complete fuzzy metric spaces by using a new technique.

• Nonlinear Functional Analysis and Applications
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• 제27권4호
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• pp.903-920
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• 2022

In this paper, we propose and study an implicit iteration process for a finite family of total asymptotically quasi-nonexpansive mappings and a finite family of asymptotically quasi-nonexpansive mappings in the intermediate sense in convex metric spaces and establish some strong convergence results. Also, we give some applications of our result in the setting of convex metric spaces. The results of this paper are generalizations, extensions and improvements of several corresponding results.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 춘계학술발표대회
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• pp.414-416
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• 2022

비디오 월 컨트롤러의 멀티스크린에 여러 영상을 동시에 표출하는 경우 운영자는 표출할 영상들을 미리 설정해두고 필요할 때 이를 불러와서 표출한다. 비디오 월 컨트롤러의 운용 상황에 따라 표출하는 영상이 달라질 수 있지만, 관련성이 높은 영상들로 레이아웃을 구성하여 표출하는 것이 일반적인 운용 방식이다. 등록되어 있는 영상의 개수가 많지 않은 소규모의 시스템에서는 영상을 선택하고 설정하는 작업이 간단하지만, 영상의 개수가 늘어날수록 영상의 설정과 관리에 많은 시간과 비용이 소요된다. 따라서 본 논문에서는 Implicit Rating과 워드투벡터를 이용하여 비디오 월 컨트롤러에 표출할 영상을 자동으로 설정하는 모델을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권4호
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• pp.1899-1911
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• 2018

In this work, we propose a concurrency control scheme in object-oriented database (OODB). Since an OODB provides complex modeling power than the conventional relational databases, a concurrency control technique in OODB is also rather complicated and has influence on the overall performance. Thus, it is very important to develop a concurrency control technique with less overhead. The proposed scheme deals with class hierarchy that is a key concept in OODBs. The proposed scheme is developed on implicit locking scheme. Also, the proposed scheme is designed using data access frequency in order to reduce locking overhead than implicit locking. It means that, if access frequency information is not available, the proposed scheme works just like the existing implicit locking, In our work, the correctness of the proposed scheme is proved. The performance is analyzed depending on access types. Also, it is proved that our scheme performs works much better than the implicit locking does.

• 전자통신동향분석
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• 제33권1호
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• pp.57-67
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• 2018

Modern users are intensifying their use of online services every day. In addition, hackers are attempting to execute advanced attacks to steal personal information protected using existing authentication technologies. However, existing authentication methods require an explicit authentication procedure for the user, and do not conduct identity verification in the middle of the authentication session. In this paper, we introduce an implicit continuous authentication technology to overcome the limitations of existing authentication technology. Implicit continuous authentication is a technique for continuously authenticating users without explicit intervention by utilizing their behavioral and environmental information. This can improve the level of security by verifying the user's identity during the authentication session without the burden of an explicit authentication procedure. In addition, we briefly introduce the definition, key features, applicable algorithms, and recent research trends for various authentication technologies that can be used as an implicit continuous authentication technology.

• 대한수학회보
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• 제55권3호
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• pp.881-898
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• 2018

This article deals with implementation of a high-order finite difference scheme for numerical solution of the incompressible Navier-Stokes equations on curvilinear grids. The numerical scheme is based on pseudo-compressibility approach. A fifth-order upwind compact scheme is used to approximate the inviscid fluxes while the discretization of metric and viscous terms is accomplished using sixth-order central compact scheme. An implicit Euler method is used for discretization of the pseudo-time derivative to obtain the steady-state solution. The resulting block tridiagonal matrix system is solved by approximate factorization based alternating direction implicit scheme (AF-ADI) which consists of an alternate sweep in each direction for every pseudo-time step. The convergence and efficiency of the method are evaluated by solving some 2D benchmark problems. Finally, computed results are compared with numerical results in the literature and a good agreement is observed.

• 한국전산유체공학회지
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• 제12권3호
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• pp.29-40
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• 2007

An implicit discontinuous Galerkin method for the two-dimensional Euler equations was developed on unstructured triangular meshes. The method can achieve high-order spatial accuracy by using hierachical basis functions based on Legendre polynomials. Numerical tests were conducted to estimate the convergence order of numerical solutions to the Ringleb flow and the supersonic vortex flow for which analytic solutions are available. Also, the flows around a 2-D circular cylinder and an NACA0012 airfoil were numerically simulated. The numerical results showed that the implicit discontinuous Galerkin methods couples with a high-order representation of curved solid boundaries can be an efficient method to obtain very accurate numerical solutions on unstructured meshes.

• 한국전산유체공학회지
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• 제16권4호
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• pp.72-83
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• 2011

A high-order discontinuous Galerkin method for the two-dimensional compressible Navier-Stokes equations was developed on unstructured triangular meshes. For this purpose, the BR2 methd(the second Bassi and Rebay discretization) was adopted for space discretization and an implicit Euler backward method was used for time integration. Numerical tests were conducted to estimate the convergence order of the numerical solutions of the Poiseuille flow for which analytic solutions are available for comparison. Also, the flows around a flat plate, a 2-D circular cylinder, and an NACA0012 airfoil were numerically simulated. The numerical results showed that the present implicit discontinuous Galerkin method is an efficient method to obtain very accurate numerical solutions of the compressible Navier-Stokes equations on unstructured meshes.

• 대한기계학회논문집B
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• 제24권10호
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• pp.1317-1325
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• 2000

A new efficient numerical method for computing three-dimensional, unsteady, incompressible flows is presented. To eliminate the restriction of CFL condition, a fully-implicit time advancement in which the Crank-Nicolson method is used for both the diffusion and convection terms, is adopted. Based on an approximate block LU decomposition method, the velocity -pressure decoupling is achieved. The additional decoupling of the intermediate velocity components in the convection term is made for the fully -implicit time advancement scheme. Since the iterative procedures for the momentum equations are not required, the velocity components decouplings bring forth the reduction of computational cost. The second-order accuracy in time of the present numerical algorithm is ascertained by computing decaying vortices. The present decoupling method is applied to minimal channel flow unit with DNS (Direct Numerical Simulation).