• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권3호
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• pp.411-427
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• 2010

Data sharing is an essential process for collaborative works particularly in the banking, finance and healthcare industries. These industries require many collaborative works with their internal and external parties such as branches, clients, and service providers. When data are shared among collaborators, security and privacy concerns becoming crucial issues and cannot be avoided. Privacy is an important issue that is frequently discussed during the development of collaborative systems. It is closely related with the security issues because each of them can affect the other. The tradeoff between privacy and security is an interesting topic that we are going to address in this paper. In view of the practical problems in the existing approaches, we propose a collaborative framework which can be used to facilitate concurrent operations, single point failure problem, and overcome constraints for two-party computation. Two secure computation protocols will be discussed to demonstrate our collaborative framework.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.1221-1224
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• 2003

A 64-point R2$^2$ SDF pipeline FFT processor using a new efficient computation sharing multiplier was designed. Computation sharing multiplication specifically targets computation re-use in multiplication of coefficient vector by scalar and is effectively used in DSP(Digital Signal Processing). To reduce the number of multipliers in FFT, we used the proposed computation sharing multiplier. The 64-point pipeline FFT processor was implemented by VHDL and synthesized using Max+PLUSII of Altera. The simulation result shows that the proposed computation sharing multiplier can be reduced to about 17.8% logic cells compared with a conventional multiplier. This processor can operate at 33MHz and calculate a 64-point pipeline FFT in 1.94 $mutextrm{s}$.

• Journal of applied mathematics & informatics
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• 제6권1호
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• pp.175-184
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• 1999

Along with the computation and analysis for nonlinear system being more and more involved in the fields such as automation control electronic technique and electrical power system the nonlin-ear theory has become quite a attractive field for academic research. In this paper we derives the solutions for state equation of nonlinear system by using the inverse operator expression of the so-lutions is obtained. An actual computation example is given giving a comparison between IOM and Runge-kutta method. It has been proved by our investigation that IOM has some distinct advantages over usual approximation methods in that it is computationally con-venient rapidly convergent provides accurate solutions not requiring perturbation linearization or the massive computation inherent in discrietization methods such as finite differences. So the IOM pro-vides an effective method for the solution of nonlinear system is of potential application valuable in nonlinear computation.

• East Asian mathematical journal
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• 제34권2호
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• pp.85-101
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• 2018

The purpose of this paper is to investigate counting-based and collection-based computation of the elementary mathematics textbook in Korea and United States of America. As a results, we will provide some suggestive points through how to use and activity of number line, decomposing number, counting, grouping and so on by analyzing counting and collection-based computation in the elementary mathematics textbook of Korea and United States of America.

• 한국IT서비스학회지
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• 제3권2호
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• pp.99-104
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• 2004

Conventional and public-key cryptography has been widely accepted as a base technology for the design of computer security systems. D-classes have the potential for application to conventional and public-key cryptography. However, there are very few results on D-classes because the computational complexity of D-class computation is NP-complete. This paper discusses the design of algorithms for the efficient computation of D-classes and the Java implementation of them. In addition, the paper implements the same D-class computation algorithms in C and shows the performance of C and Java programming languages for the computation-intensive applications by comparing their execution results.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제2권1호
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• pp.37-52
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• 1998

The purpose is this study is to investigate the children's, parents's, teachers consciousness to the use of calculator in mathematics loaming and to analyze the effect of the problem solving and computation ability. The results obtained by this research are as follows： (1) Most adults using calculator by computation tool. but they believed that if children use calculator, computation abilities might be reduced. (2) By using the calculator, We can do the followings ： \circled1 to expand the computational ability from written computation to both mental computation and computational estimation, \circled2 to reinforce the problem solving abilities, \circled3 to obtain the interest and the curios on mathematics loaming. Therefore, we must endeavor actively for the broad usage of calculator in the mathematics class

• 한국통신학회논문지
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• 제23권4호
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• pp.1024-1034
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• 1998

정보통신망에서 사용하는 공개키 암호시스템은 대부분 지수 연산을 사용한다. 하지만, 암호시스템은 안전성을 고려한 큰 수의 지수 연산을 사용하기 때문에 많은 계산 량과 준비시간을 요구한다. 이러한 문제점을 해결하기 위하여 모듈러 감소 연산에서 Montgomery, Yang, Kawamura 등이 사전계산 방법, 중간계산, 그리고 테이블을 사용하는 방법을 제안하였으며, 지수 연산에서 Coster, Brickel, Lee 등이 addition chain, window, 그리고 고정된 수를 사용하는 경우 사전 계산을 하는 방법을 제안하였다. 본 논문에서는 sparse 소수를 사용한 모듈러 감소 연산 방법을 제안하고 지수연산시 계산 량을 줄이는 방법을 제안한다. 이는 이산대수 방식의 암호시스템에서 매우 효과적으로 적용할 수 있다.

• 대한전기학회논문지
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• 제43권2호
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• pp.189-196
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• 1994

This paper describes a parallel computing algorithm in Gauss elimination of Jacobian matrix to large-scale power system. The structure of Jacobian matrix becomes different according to ordering method of buses. In sequential computation buses are ordered to minimize the number of fill-in in the triangulation of the Jacobian matrix. The proposed method develops the parallelism in the Gauss elimination by using ND(nested dissection) ordering. In this procedure the level structure of the power system network is transformed to be long and narrow by using end buses which results in balance of computing load among processes and maximization of parallel computation. Each processor uses the sequential computation method to preserve the sqarsity of matrix.

• 대한전기학회논문지
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• 제45권2호
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• pp.265-272
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• 1996

In this paper, attitude computation algorithm for a strap down ARS(Attitude Reference System)of an underwater vehicle has been studied. Attitude errors o the ARS using low-level gyroscopes tend to increase with time due to gyroscope errors. To cope with this problem, a mixing algorithm of accelerometer aided attitude computation has been developed. The algorithm can successfully bound the error increase for cruising motion, but it gives instantaneously large errors when a vehicle maneuvers. To improve the performance in case of vehicle's maneuver, a new attitude computation mixing algorithm complying state of vehicle and to manage the adjustment of the gains which are invariant in the existing algorithm. In addition, a gain scheduling method is applied to fuzzy inference composition process for real-time computation. Monte Carlo simulation results show that the proposed algorithm provides better performance than the existing algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권1호
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• pp.281-298
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• 2020

Fog computing has become a popular concept in the application of internet of things (IoT). With the superiority in better service providing, the edge cloud has become an attractive solution to IoT networks. The data outsourcing scheme of IoT devices demands privacy protection as well as computation verification since the lightweight devices not only outsource their data but also their computation. Existing solutions mainly deal with the operations over encrypted data, but cannot support the computation verification in the same time. In this paper, we propose a data outsourcing scheme based on an encrypted database system with linear computation as well as efficient query ability, and enhance the interlayer program in the original system with homomorphic message authenticators so that the system could perform computational verifying. The tools we use to construct our scheme have been proven secure and valid. With our scheme, the system could check if the cloud provides the correct service as the system asks. The experiment also shows that our scheme could be as effective as the original version, and the extra load in time is neglectable.