• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.799-804
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• 1989

A new method for measuring optical phase changes of reflection beam from optical mirror is proposed. The optical phase change is liable to change with varying atmosphere conditions. This optical phase changes are measured against air pressure, temperature, humidity and CO$\_$2/ concentration variations. It is clarified that the optical phase changes are most effected by humidity change.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.5
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• pp.101-106
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• 2020

Since computer became available, much effort has been made to achieve information security. Even though memory protection defense mechanisms were studied the most among of them, the problems of existing memory protection defense mechanisms were found due to improved performance of computer and new defense mechanisms were needed due to the advent of the side-channel attacks. In this paper, we propose JMP+RAND that embedding random values of 5 to 8 bytes per page to defend against memory sharing based side-channel attacks and bridging the gap of existing memory protection defense mechanism. Unlike the defense mechanism of the existing side-channel attacks, JMP+RAND uses static binary rewriting and continuous jmp instruction and random values to defend against the side-channel attacks in advance. We numerically calculated the time it takes for a memory sharing-based side-channel attack to binary adopted JMP+RAND technique and verified that the attacks are impossible in a realistic time. Modern architectures have very low overhead for JMP+RAND because of the very fast and accurate branching of jmp instruction using branch prediction. Since random value can be embedded only in specific programs using JMP+RAND, it is expected to be highly efficient when used with memory deduplication technique, especially in a cloud computing environment.

• Archives of Pharmacal Research
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• v.21 no.1
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• pp.12-16
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• 1998

The inhibitory effect of 10 lignan constituents isolated from the rhizomes of Coptis japonica var. dissects on tumor necrosis factor (TNF)-${\alpha}$ production in lipopolysaccharide (LPS)-stimulated macrophage cell line (RAW264.7 cells) has been studied. Among them, pinoresinol, woorenoside-V and lariciresinol glycoside showed significant inhibitory activities in the range from 37% to 55% at the concentration of $25{\mu}g/ml.$ The results are first report that the lignans isolated from Coptis japonica inhibit TNF- ${\alpha}$${\alpha}$

• Smart Media Journal
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• v.13 no.2
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• pp.129-135
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• 2024

In this paper, we propose a new approach that enhances the continuous optimization performance of the MAP-Elites algorithm. The existing self-referencing MAP-Elites algorithm employed the "DE/rand/1/bin" operator from the differential evolution algorithm, which, due to its lack of rotational invariance, led to a degradation in optimization performance when there were high correlations among variables. The proposed algorithm replaces the "DE/rand/1/bin" operator with the "DE/current-to-rand/1" operator. This operator, possessing rotational invariance, ensures robust performance even in cases where there are high correlations among variables. Experimental results confirm that the proposed algorithm performs better than the comparison algorithms.

• Management & Information Systems Review
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• v.33 no.2
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• pp.171-188
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• 2014

Previous researches on technological innovation of SMEs have several limitations such as lack of study for industrial cluster system and entrepreneurship in SMEs, and ignoring role of RandD capability. So, this study suggested empirically a new model to SMEs. Major results are as follows. Firstly, system of industry and production had a significant and positive effect on entrepreneurship. Secondly, entrepreneurship had a significant and positive effect on technological innovation. Thirdly, system of science and technology had positive and significant effects on RandD capability and technological innovation. Fourthly, RandD capability had a positive and significant effect on technological innovation. Fifthly, business support system was not significantly related to entrepreneurship, RandD capability and technological innovation. Research results revealed that industrial cluster system(system of industry and production, system of science and technology), entrepreneurship and RandD capability were important for improvement of technological innovation performance in SMEs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.5
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• pp.1282-1290
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• 1998

In this paper, the physical layer design of IMT-2000 system being developed by SK Telecom is introuduced. The outband signaling scheme and the two-pilot scheme are adopted for multimedia service and inter-cell asynchronous mode respectively. In addition, the synchronous transmission scheme is proposed to reduce the interference in the reverse link. The algorithm and simulation results of 'two-pilot scheme' for inter-cell asynchronous mode and 'reverse synchronous control' for synchronous transmission are presented.

• The Korean Journal of Applied Statistics
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• v.18 no.2
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• pp.329-341
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• 2005

A method of determining the number of clusters is proposed based on some asymptotic results on the Rand's(1971} $C_k$, k = 2, 3, . . ., N - 1, statistic. Simulation is conducted to compare the proposed method with Chae and Warde(1991), and Huh and Lee(2004).

• The Korean Journal of Applied Statistics
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• v.25 no.3
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• pp.471-483
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• 2012

One of the most important problems in cluster analysis is the selection of variables that truly define cluster structure, while eliminating noisy variables that mask such structure. Brusco and Cradit (2001) present VS-KM(variable-selection heuristic for K-means clustering) procedure for selecting true variables for K-means clustering based on adjusted Rand index. This procedure starts with the fixed number of clusters in K-means and adds variables sequentially based on an adjusted Rand index. This paper presents an updated procedure combining the VS-KM with the automated K-means procedure provided by Kim (2009). This automated variable selection procedure for K-means clustering calculates the cluster number and initial cluster center whenever new variable is added and adds a variable based on adjusted Rand index. Simulation result indicates that the proposed procedure is very effective at selecting true variables and at eliminating noisy variables. Implemented program using R can be obtained on the website "http://faculty.knou.ac.kr/sskim/nvarkm.r and vnvarkm.r".

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1405-1409
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• 1990

Generally, the required control functions for the industrial auto trimming sewing machines are the sewing speed control with pedal input, the up/down stopping-position control of the needle, the automatic sewing according to the memorized sewing pattern including the number of stitches, and etc. We developed a new type of AC servo motor controller, which suffices for all the above functions. The developped controller is working well, and the performances are very good for the practical use.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1420-1423
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• 1990

DC series motor has been widely applicated in industry due to many advantageous characteristics, such as high starting torque, easy construction of its controller, and cost economy, etc.. However, by high starting current, excessive surge voltage, and so on, many problems which could make engineers relinguish to use it are induced. In this paper, various protection methods for power circuit are discussed. Particularly, a new proposed snubber circuit which consists of two diodes, one capacitor, and a resistor increases the performance with respect to the suppression of the surge voltage. Furthermore, the plugging algorithm, by checking the armature current and voltage and controlling the field coil current, is designed and implemented. Also, these methods and algorithms were applicated in electric vehicle, and we could find its stability to be considerably improved.