• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.281-284
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• 2002

Rijndael algorithm is known to a new private key block cipher which is substitute for DES. Rijndael algorithm is adequate to both hardware and software implementation, so hardware implementation of Rijndael algorithm is applied to high speed data encryption and decryption. This paper describes three implementation methods of Rijndael S-box, which is important factor in performance of Rijndael coprocessor. It shows synthesis results of each S-box implementation in Xilinx FPGA. Tllc lilree S-box implementation methods are implementation using lookup table only, implementation using both lookup table and combinational logic, and implementation using combinational logic only.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제7권2호
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• pp.95-111
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• 2003

BDM mixed methods are obtained for a good approximation of velocity for flow equations. In this paper, we study an implementation issue of solving the algebraic system arising from the BDM mixed finite elements. First we discuss post-processing based on the use of Lagrange multipliers to enforce interelement continuity. Furthermore, we establish an equivalence between given mixed methods and projection finite element methods developed by Chen. Finally, we present the implementation of the first order BDM on rectangular grids and show it is as simple as solving the pressure equation.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제25권3호
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• pp.66-81
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• 2021

In this paper, we review the lowest order staggered discontinuous Galerkin methods on polygonal meshes in 2D. The proposed method offers many desirable features including easy implementation, geometrical flexibility, robustness with respect to mesh distortion and low degrees of freedom. Discrete function spaces for locally H¹ and H(div) spaces are considered. We introduce special properties of a sub-mesh from a given star-shaped polygonal mesh which can be utilized in the construction of discrete spaces and implementation of the staggered discontinuous Galerkin method. For demonstration purposes, we consider the lowest case for the Poisson equation. We emphasize its efficient computational implementation using only geometrical properties of the underlying mesh.

• Structural Engineering and Mechanics
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• 제75권5호
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• pp.541-557
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• 2020

A novel family of controllable, dissipative structure-dependent integration methods is derived from an eigen-based theory, where the concept of the eigenmode can give a solid theoretical basis for the feasibility of this type of integration methods. In fact, the concepts of eigen-decomposition and modal superposition are involved in solving a multiple degree of freedom system. The total solution of a coupled equation of motion consists of each modal solution of the uncoupled equation of motion. Hence, an eigen-dependent integration method is proposed to solve each modal equation of motion and an approximate solution can be yielded via modal superposition with only the first few modes of interest for inertial problems. All the eigen-dependent integration methods combine to form a structure-dependent integration method. Some key assumptions and new techniques are combined to successfully develop this family of integration methods. In addition, this family of integration methods can be either explicitly or implicitly implemented. Except for stability property, both explicit and implicit implementations have almost the same numerical properties. An explicit implementation is more computationally efficient than for an implicit implementation since it can combine unconditional stability and explicit formulation simultaneously. As a result, an explicit implementation is preferred over an implicit implementation. This family of integration methods can have the same numerical properties as those of the WBZ-α method for linear elastic systems. Besides, its stability and accuracy performance for solving nonlinear systems is also almost the same as those of the WBZ-α method. It is evident from numerical experiments that an explicit implementation of this family of integration methods can save many computational efforts when compared to conventional implicit methods, such as the WBZ-α method.

• ETRI Journal
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• 제26권3호
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• pp.241-251
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• 2004

We propose two improved scalar multiplication methods on elliptic curves over $F_{{q}^{n}}$ $q= 2^{m}$ using Frobenius expansion. The scalar multiplication of elliptic curves defined over subfield $F_q$ can be sped up by Frobenius expansion. Previous methods are restricted to the case of a small m. However, when m is small, it is hard to find curves having good cryptographic properties. Our methods are suitable for curves defined over medium-sized fields, that is, $10{\leq}m{\leq}20$. These methods are variants of the conventional multiple-base binary (MBB) method combined with the window method. One of our methods is for a polynomial basis representation with software implementation, and the other is for a normal basis representation with hardware implementation. Our software experiment shows that it is about 10% faster than the MBB method, which also uses Frobenius expansion, and about 20% faster than the Montgomery method, which is the fastest general method in polynomial basis implementation.

• ETRI Journal
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• 제32권3호
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• pp.370-379
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• 2010

In this paper, we propose efficient masking methods for ARIA and AES. In general, a masked S-box (MS) block can be constructed in different ways depending on the implementation platform, such as hardware and software. However, the other components of ARIA and AES have less impact on the implementation cost. We first propose an efficient masking structure by minimizing the number of mask corrections under the assumption that we have an MS block. Second, to make a secure and efficient MS block for ARIA and AES, we propose novel methods to solve the table size problem for the MS block in a software implementation and to reduce the cost of a masked inversion which is the main part of the MS block in the hardware implementation.

• Healthcare Informatics Research
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• 제24권4호
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• pp.263-275
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• 2018

Objectives: Automated audiometry provides an opportunity to do audiometry when there is no direct access to a clinical audiologist. This approach will help to use hearing services and resources efficiently. The purpose of this study was to review studies related to automated audiometry by focusing on the implementation of an audiometer, the use of transducers and evaluation methods. Methods: This review study was conducted in 2017. The papers related to the design and implementation of automated audiometry were searched in the following databases: Science Direct, Web of Science, PubMed, and Scopus. The time frame for the papers was between January 1, 2010 and August 31, 2017. Initially, 143 papers were found, and after screening, the number of papers was reduced to 16. Results: The findings showed that the implementation methods were categorized into the use of software (7 papers), hardware (3 papers) and smartphones/tablets (6 papers). The used transducers were a variety of earphones and bone vibrators. Different evaluation methods were used to evaluate the accuracy and the reliability of the diagnoses. However, in most studies, no significant difference was found between automated and traditional audiometry. Conclusions: It seems that automated audiometry produces the same results compared with traditional audiometry. However, the main advantages of this method; namely, saving costs and increased accessibility to hearing services, can lead to a faster diagnosis of hearing impairment, especially in poor areas.

• 경영과학
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• 제17권2호
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• pp.1-12
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• 2000

In this study, we deals with the implementation of an optimal basis identification procedure for interior point methods. Our implementation is based on Megiddo’s strongly polynomial algorithm applied to Andersen and Ye’s approximate LP construction. Several techniques are explained such as the use of effective indicator for obtaining optimal partition when constructing the approximate LP, the efficient implementation of the problem reduction technique proposed by Andersen, the crashing procedure needed for fast dual phase of Megiddo’s algorithm and the construction of the stable initial basis. By experimental comparison, we show that our implementation is superior to the crossover scheme implementation.

• 경영과학
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• 제30권1호
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• pp.59-72
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• 2013

This research has seven factors such as top management leadership, belt system operation, implementation of systematic methods, adequate project performance measurement, customer focus performance, quality performance and business performance. Those are critical to correct implementation of Six Sigma. I set seven hypotheses which represented the relationships among the seven factors, gathered questionnaires and analyzed the data. Top management leadership affected positively the adequate project performance measurement and the belt system operation, The belt system operation affected the implementation of systematic methods positively and it also affected the adequate project performance measurement. It affected positively the customer focus performance, the quality performance and the business performance, respectively.

• 환경영향평가
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• 제27권4호
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• pp.345-352
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• 2018

기후변화 적응 주류화를 위하여 세 가지 기후변화영향평가 시행 방안을 검토하였다. 첫째, 신법 마련 및 개별 시행, 둘째, 신법 마련 및 환경영향평가 틀 내 제도 시행, 셋째, 기존 환경영향평가 틀 내 시행하는 것이다. 이 논문에서는 세 가지 방안의 내용, 장 단점을 분석하였다. 그리고 신법 하에서 제도를 개별 시행할 경우의 개략적인 평가 내용과 환경영향평가 틀 내에서 시행하고자 할 경우 관련 법률, 규정개정(안)을 제안하였다.