• Management & Information Systems Review
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• v.27
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• pp.53-69
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• 2008

In this paper we analyse performance of value strategy and moving average method among the non-financial listed companies whose fiscal year ends at December in the Korean Stock Exchange between 1996 and 2005. And we analyse combination investment performance of value investment and moving average method. After the analysis objective enterprises divide with the value stock and the growth stock, in accordance with moving average method we divide ascending stock and descending stock. And we compose 6 portfolios with combination of value stock, growth stock, ascending stock and descending stock. Using the difference of investment performance of these portfolios, when fundamental analysis and technical analysis method all considering we measure investment performance. The major findings of this research are as follows: First, the value strategy of buying value stocks and selling growth stocks were effective in the long-term investment. Second, using the moving average method, technical analysis were effective in the case of the short-term investment. Third, the portfolios combined fundamental analysis and technical analysis were more effective than investment performance of technical analysis.

• Journal of the Korean institute of surface engineering
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• v.38 no.6
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• pp.216-226
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• 2005

Pb-Free Technology was born with environmental problems of electronic component, Being connected by big and small project of every country. Also, in each country environment is connected and various standards of IEC, ISO, MIL, JIS, KS, JEDEC, EIAJ etc. All products can divide at solder part and finishing part These can tested each and synthetically divide. This research is reliability evaluation for three kind of ph-free SnCu solder plating solution and it's deposit. First, executed analysis about Pure Sn, SnCu solutions and plating surface by way similar to other plating solution analysis. Next, executed reliability about test method and equipment for reliable analyzer system construction. Next, data comparison and estimation, main estimation test method and item's choice. In this paper the systematic surface analysis and reliability for plating solutions and it's deposit in metal surface finishing processes could be shown.

• Speech Sciences
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• v.5 no.1
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• pp.89-103
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• 1999

It is relatively easy to develop a prototype of a Korean language processing system, but it is very difficult to make it an operational system. In this paper, we survey the current status and methodological issues of the Korean language processing systems such as morphological analyzer, parser and machine translator. In most cases, Korean language processing system easily comes to a dead-end state where its performance can not be improved any more. The reason is that it adopts a general algorithm covering similar problems as a whole because specific low-level problems are not clearly defined and their algorithms are unclear. So, when we add some restrictions to solve an individual linguistic problem, they are also applied to other linguistic phenomena as a side effect. It causes a critical problem that the improvement of the algorithm is very difficult. This paper proposes a 2-step paradigm, a divide-and-conquer method by the functional modularization, a simplification method, and an exception handling technique to develop an operational system that does not fall into a dead-end state.

• Journal of The Korean Association of Information Education
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• v.12 no.4
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• pp.477-484
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• 2008

At the point of time needing intergrated plan in each field for preparing the unification between the South and the North of Korea. They show the biggest difference in the field of information and expecting that cultural difference in various fields cause huge expense after unification and prevent both the South and the North of Korea from being unified. By the method of Delphi, we can clear the question of the Digital Divide we have more efficiency and systematic policy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4502-4518
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• 2015

Fisher linear discriminant analysis (LDA) is one of the most popular projection techniques for feature extraction and has been widely applied in face recognition. However, it cannot be used when encountering the single sample per person problem (SSPP) because the intra-class variations cannot be evaluated. In this paper, we propose a novel method called local similarity based linear discriminant analysis (LS_LDA) to solve this problem. Motivated by the "divide-conquer" strategy, we first divide the face into local blocks, and classify each local block, and then integrate all the classification results to make final decision. To make LDA feasible for SSPP problem, we further divide each block into overlapped patches and assume that these patches are from the same class. To improve the robustness of LS_LDA to outliers, we further propose local similarity based median discriminant analysis (LS_MDA), which uses class median vector to estimate the class population mean in LDA modeling. Experimental results on three popular databases show that our methods not only generalize well SSPP problem but also have strong robustness to expression, illumination, occlusion and time variation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.8 s.111
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• pp.732-738
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• 2006

Divide-by-2 and divide-by-4 circuits which can operate up to 10 GHz are designed. A design method used in these circuits is the TSPC(True Single Phase Clocking) topology. The structure of the TSPC dividers is very simple because they need only a single clock and purely consist of smalt sized cmos devices. Through measurements, we find the fact that in proportion to the bias voltage, the free running frequency increases and the operation region also moves toward a higher frequency region. For operating conditions of bias voltage $3.0{\sim}4.0V$, input power 16dBm and dcoffset $1.5{\sim}2.0V$, 5 GHz and 2.5 GHz output signals divided by 2 and 4 are measured. The layout size of the divide-by-2 circuit is about $500{\times}500 um^2$($50{\times}40um^2$ except pad interconnection part).

• Radiation Oncology Journal
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• v.5 no.2
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• pp.165-168
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• 1987

The generalized Bathe method, proposed by Webb and Fox, which is a method of calculation of dose correction factor for the purpose of heterogeneous tissue, is complex even for a few kind of tissues. The method was modified for the purpose of getting a simple method that divide the multilayer of heterogeneous tissues into some groups of adjacent-tissue pairs. This new method could reduce the number of exponential terms and the time for calculating the dose correction factors by manual and computer calculation.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.551-556
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• 2009

3-D CAD (Computer Aided Design) system is an indispensable tool for manufacturing. A lot of engineers have studied for the methods to generate a curved surface on an N-sided shape, which is the basic technology of 3-D CAD systems. This surface generation, however, has three problems on the case of long and narrow shapes: the resultant surface is distorted, the surface is not continuous to adjacent surfaces, or additional user inputs are required to generate the surface. Conventional methods have not yet solved these problems at the same time. In this paper, we propose the method to generate internal curves that divide a long and narrow shape into regular N-sided sections so as to divide the shape into an N-sided section and four-sided ones. Our method controls the shape of internal curves by dividing an N-sided long and narrow shape into an N-sided section and four-sided ones, and solves distortion of the generated curved surface. In addition, each of the generated sections is interpolated with G1-continuous surfaces. This process does not require any user's further input. Therefore, the three problems mentioned above will be solved at the same time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.5
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• pp.374-383
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• 1990

For a visual inspectio system to be viable, it must in general achieve the same or lower costs as those incurred by manual methods, it must have a reasonable inspection rate, and it must be reliable and maintainable : for the visual inspection system, inspection at high speed, flexibility for variety of products, and low cost are needed. In order to solve these problems, we propose the visual inspection algorithm by divide-and-conquer technique using the pyramid data structure and the development of simplified pattern matching method. By this method we can reduce the number of data required to compare with patterns and make the inspection time short.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.892-911
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• 2019

Biometric recognition systems have been widely used for information security. Among the most popular biometric traits, there are fingerprint and face due to their high recognition accuracies. However, the security system that uses face recognition as the login method are vulnerable to face-spoofing attacks, from using printed photo or video of the valid user. In this study, we propose a fast and robust method to detect face-spoofing attacks based on the analysis of spatial frequency differences between the real and fake videos. We found that the effect of a spoofing attack stands out more prominently in certain regions of the 2D Fourier spectra and, therefore, it is adequate to use the information about those regions to classify the input video or image as real or fake. We adopt a divide-conquer-aggregate approach, where we first divide the frequency domain image into local blocks, classify each local block independently, and then aggregate all the classification results by the weighted-sum approach. The effectiveness of the methodology is demonstrated using two different publicly available databases, namely: 1) Replay Attack Database and 2) CASIA-Face Anti-Spoofing Database. Experimental results show that the proposed method provides state-of-the-art performance by processing fewer frames of each video.