• Computers and Concrete
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• v.31 no.1
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• pp.1-7
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• 2023

In this paper, Timoshenko-beam model is developed for the vibration of double carbon nanotubes. The resulting frequencies are gained for axial wave mode and length-to-diameter ratios. The natural frequency becomes more prominent for lower length-to-diameter ratios and diminished for higher ratios. The converse behavior is observed for axial wave mode with clamped-clamped and clamped-free boundary conditions. The frequencies of clamped-free are lower than that of clamped-clamped boundary condition. The eigen solution is obtained to extract the frequencies of double walled carbon nanotubes using Galerkin's method through axial deformation function. Computer softer MATLAB is used for formation of frequency values. The frequency data is compared with available literature and found to be in agreement.

• Journal of the Korean Mathematical Society
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• v.61 no.2
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• pp.395-408
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• 2024

There have been numerous studies on the characteristics of the solutions of ordinary differential equations for optimization methods, including gradient descent methods and alternating direction methods of multipliers. To investigate computer simulation of ODE solutions, we need to trace pseudo-orbits by real orbits and it is called shadowing property in dynamics. In this paper, we demonstrate that the flow induced by the alternating direction methods of multipliers (ADMM) for a C² strongly convex objective function has the eventual shadowing property. For the converse, we partially answer that convexity with the eventual shadowing property guarantees a unique minimizer. In contrast, we show that the flow generated by a second-order ODE, which is related to the accelerated version of ADMM, does not have the eventual shadowing property.

• Journal of Korea Multimedia Society
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• v.3 no.4
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• pp.416-423
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• 2000

The existing self-organizing feature map of Kohonen has weakpoint that need too much input patterns in order to converse into the learning rate and equilibrium state when it trains. Making up for the current weak point, B.Bavarian suggested the method of that distributed the learning rate such as Gaussian function. However, this method has also a disadvantage which can not achieve the right self-organizing. In this paper, we proposed the method of improving the convergence speed and the convergence rate of self-organizing feature map converting the Gaussian function into dynamic approximate curve used in when trains the self-organizing feature map.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4503-4508
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• 2010

A direction finding(DF) technology of a signal is very important for electronic warfare and has studied for a long time. The method of TDOA(time difference of arrival) is one of good DF methods in this time, and that is to receive an emitter signal with two antennas, to measure the time difference of a signal at two antennas, and converse the time difference to direction of the signal. For small DF error, high time resolution receiver and long baseline are needed. In this paper we suggest a good baseline with adaptive antenna arrangement into 10m*10m area.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.1027-1031
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• 1994

A method for the process of making fig conserves to prevent the denaturation of ficin (EC3.422.3) that is a proteolytic enzyme in fig (Fixus carica L. ) has been developed. The suutable composition ratio of materials such as, fig, sugar, citric acid and potassium sorbate, to make fig conserves was 1,000, 600 , 1.0 and 0.67g , respectively. to maintain the ficin activity, it was necessary that these materials were heated on 55$^{\circ}C$ and concentrated in the reduced pressure. At a result of sensory evaluation , meat treated with fig was the softest among samples. Then the treated beef with 55$^{\circ}C$ converse, 7$0^{\circ}C$ conserves, sugar and control have been shown the decreased rate respectively. There was significantly different in the effect of tenderness between each group(0.1%) . The nitrogen content of connective tissue was relatively low in the groups of the treated beef with fig and 55$^{\circ}C$ converses, 7$0^{\circ}C$ converses sugar and control , which was similar to the order of the ficin activity. This research revealed that the constituent protein of meat muscle was decomposed by ficin and its solubility was relatively higher than before.

• Computers and Concrete
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• v.25 no.5
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• pp.411-425
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• 2020

In this paper, the shell material has been taken as functionally graded material and their material quantity is located by the exponential volume fraction law. Moreover, the impact of ring supports around the shell circumference has been examined for their various positions along the shell axial length. These rings support restraints the radial displacement in the transverse direction. While the axial modal deformation functions have been estimated by characteristic beam functions and nature of materials used for construction of cylindrical shells. The fundamental natural frequency of cylindrical shell of parameter versus ratios of length- and height-to-radius for a wide range has been reported and investigated through the study. In addition, by increasing height-to-radius ratio resulting frequencies also increase and frequencies decrease on ratio of length-to-radius. Though the trends of frequency values of both ratios are converse to each other with three different boundary conditions. Also it is examined the position of ring supports with length-to radius ratio, height-to-radius ratio and varying the exponent of volume fraction. MATLAB software package has been utilized for extracting shell frequency spectra. The obtained results are confirmed by comparing with available literature.

• East Asian Journal of Business Economics (EAJBE)
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• v.4 no.2
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• pp.1-11
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• 2016

This study investigated commercial power theory of traditional market through the analysis of literature review. Consumers' store selection models are made up a theory based on normative hypothesis, theory of mutual reaction, utility function estimation model, and cognitive-behavioral model. Detailed models are as follows. Normative hypothesis based theory is divided into Reilly's retail gratification theory and Converse's revised retail g ratification theory. Interaction theory is composed of Huff's probability gratification theory, MCI model and Multi-nominal Logit Model (MNL model). There are four models in retail organization position theory such as central place theories, single store position theory, multi store position - assign model, and retail growth potential model. In case of single store position theory, theoretical and empirical techniques have developed for a decision to optimum single store position. Those are like these, a check list, the most simple and systematic method, analogy, and microanalysis technique. Aforementioned models are theoretical and mathematical commercial power measurement and/or model. The study has rather limitations because the variation factors included in formula are only a part of actual commercial power. Therefore, further study shall be made continuously to commercial power areas and variables.

• Journal of Convergence for Information Technology
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• v.7 no.6
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• pp.245-251
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• 2017

This presents an English conversation training system with which learners train their conversation skills in English, which makes them converse with native speaker characters in a virtual reality environment with voice. The proposed system allows the learners to talk with multiple native speaker characters in varous scenarios in the virtual reality environment. It recongizes voices spoken by the learners and generates voices by a speech synthesis method. The interaction with characters in the virtual reality environment in voice makes the learners immerged in the conversation situations. The scoring system which evaluates the learner's pronunciation provides the positive feedback for the learners to get engaged in the learning context.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.431-433
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• 2010

VoIP is a communication technique can be used anywhere you can find wifi signal and it costs much lower than conventional mobile service. However, security of VoIP is not as robust as former, the converse could be easily intercepted and attacked especially in MANETs which the attackers access easier than in wired networks. Sercurity of VoIP system in MANETs is an important issue nowadays. In this paper, a typical attack method of VoIP systems in MANETs is described and we implement how to prevent it.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5208-5213
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• 2011

In this paper, we proposed a new direction finding(DF) technology using TDOA(time-difference of arrival) and PDOA(phase difference of arriving signal) method. The proposed technology has a good DF accuracy without DF ambiguity. TDOA or PDOA technology is used to the most of intelligence systems in 21 century. The principle of TDOA is to receive a signal with two parallel antennas, measure the time difference of arrival signal, and converse the time difference to the direction of incident signal. Those technology make a DF system small size but the DF accuracy is low into short antenna installation distance. The principle of PDOA is similar to TDOA except measuring the phase difference of arrival signal, These technology get a good DF accuracy in short antenna installation distance but have a DF ambiguity. The proposed DF method is simulated into DF system operation environment with noise, and has a good DF accuracy.