• Progress in Superconductivity and Cryogenics
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• v.24 no.1
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• pp.13-17
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• 2022

The mechanical properties of REBCO coated conductor (CC) tapes under uniaxial tension are mainly determined by the thick layer Components like the substrate and the stabilizer. Depending on the applications of the CC tapes, it is also needed to externally reinforce thin metallic foils to one side or both sides of the CC tapes. This study investigated the effect of additional stabilizer layers or lamination on the electrical resistivity and electromechanical properties in RCE-DR processed GdBCO CC tapes with different structures. The strain/stress tolerance of I_c in differently processed 12 mm-wide REBCO CC tapes under uniaxial tension at 77 K and self-field could be determined by the loading-unloading scheme. As a result, Sn-Cu stabilized CC tape showed a significant decrease in mechanical properties due to its soft but thick stabilizing layer. However, similar electromechanical properties have been observed on both Sn-Cu and Sn-stabilized CC tapes, the I_c degradation behavior was independent of whether the CC tape has an external reinforcement or different stabilizing layers.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.2
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• pp.50-59
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• 1998

This paper presents stabilization and adaptive control of flexible single link robot manipulator system by self-recurrent neural networks that is one of the neural networks and is effective in nonlinear control. The architecture of neural networks is a modified model of self-recurrent structure which has a hidden layer. The self-recurrent neural networks can be used to approximate any continuous function to any desired degree of accuracy and the weights are updated by feedback-error learning algorithm. When a flexible manipulator is rotated by a motor through the fixed end, transverse vibration may occur. The motor toroque should be controlled in such a way that the motor rotates by a specified angle, while simultaneously stabilizing vibration of the flexible manipuators so that it is arresed as soon as possible at the end of rotation. Accurate vibration control of lightweight manipulator during the large changes in configuration common to robotic tasks requires dynamic models that describe both the rigid body motions, as well as the flexural vibrations. Therefore, a dynamic models for a flexible single link robot manipulator is derived, and then a comparative analysis was made with linear controller through an simulation and experiment. The results are proesented to illustrate thd advantages and imporved performance of the proposed adaptive control ove the conventional linear controller.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.8
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• pp.1-6
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• 1992

This paper proposed a neural computer architecture for the learning of script character pattern recognition categories. Oriented filter with complex cells preprocess about the input script character, abstracts contour from the character. This contour normalized and inputed to the ART. Top-down attentional and matching mechanisms are critical in self-stabilizing of the code learning process. The architecture embodies a parallel search scheme that updates itself adaptively as the learning process unfolds. After learning ART self-stabilizes, recognition time does not grow as a function of code complexity. Vigilance level shows the similarity between learned patterns and new input patterns. This character recognition system is designed to adaptable. The simulation of this system showed satisfied result in the recognition of the hand written characters.

• Journal of The Korean Astronomical Society
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• v.37 no.4
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• pp.243-248
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• 2004

Disk galaxies abound with intermediate-scale structures such as OB star complexes, giant clouds, and dust spurs in a close geometrical association with spiral arms. Various mechanisms have been proposed as candidates for their origin, but a comprehensive theory should encompass fundamental physical agents such as self-gravity, magnetic fields, galactic differential rotation, and spiral arms, all of which are known to exist in disk galaxies. Recent numerical simulations incorporating all these physical processes show that magneto-Jeans instability (MJI), in which magnetic tension resists the stabilizing Coriolis force of galaxy rotation, is much more powerful than swing-amplification or the Parker instability in forming self-gravitating intermediate-scale structures. The MJI occurring in shearing and expanding flows off spiral arms rapidly forms structures elongated along the direction perpendicular to the arms, remarkably similar to dust spurs seen in HST images of spiral galaxies. In highly nonlinear stages, these spurs fragment to form bound clumps, possibly evolving into bright arm and interarm H II regions, suggesting that all these intermediate-scale structures in spiral galaxies probably share a common dynamical origin.

• Korean Journal of Microbiology
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• v.35 no.4
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• pp.253-257
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• 1999

Effects of polyamines such as cadaverine, putrescine, spermidine and spermine on the self-splicig inhibition of the T4 phage thymidylate synthase(td) intron by spectinomycin have been investrigated. Without polyamine 7mM spectinomycin caused 40% reduction of the splicing rate. Cadaverine reduced the splicing rate over the concentrations of 0.1 to 5 mM. Putrescine at 0.5 mM increased the splicing rate by 13%. Spermidine at 0.5 mM enhanced the splicing rate by 11% while spermine at 0.01 mM enhanced the splicing rate by 16%. Of the all polyamines tested, spermine exhibited the maximum activation effect to counteract the splicing inhibition by spectinomycin. This effect appears to be due to the role of polyamine in stabilizing the conformation of td intron ribozyme essential for the catalytic function.

• Child Health Nursing Research
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• v.7 no.3
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• pp.383-396
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• 2001

This study was designed to investigate the effects of the progressive muscle relaxation on behavioral states and emotional reactions of adolescent athletes. The participants were 167 adolescent male soccer players aged between 12 and 18 who were junior or high school students in Seoul. Ninety-three of them were assigned to the experimental group, while seventy-four to the control group. The experimental group was treated by 10 sessions (20 min./session) of Jacobson's progressive muscle relaxation for two weeks, while the control group was not treated. The self and observer reported behavioral states, general stress by visual analogue scale, physical symptoms of stress, athletic stress, state anxiety, depression, self-esteem were measured before and after two weeks of the progressive muscle relaxation. The results were as follows ; 1. The self and observer reported behavioral states were significantly decreased in the experimental group compared with the control group. 2. The general stress and the gastrointestinal symptoms of stress were significantly decreased in the experimental group compared with the control group. No significant difference on athletic stress was found between the two groups. The depression and the state anxiety were significantly decreased in the experimental group compared with the control group. The self-esteem was significantly increased in the experimental group compared with the control group. 3. The influential factors on behavioral state of adolescent male athlete were depression and state anxiety. The accelerating factor on behavioral state change after the progressive muscle relaxation was state anxiety. These results are suggested that the progressive muscle relaxation could be effective in stabilizing behavioral state, decreasing general stress, gastrointestinal symptoms of stress, depression, state anxiety, in increasing self-esteem of adolescent male athletes. And the behavioral state change after the progressive muscle relaxation was influenced by state anxiety.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.8
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• pp.507-516
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• 2013

Mobile devices have limited computing power and resources. Since mobile devices are equipped with rich network connectivity, an approach to subscribe cloud services can effectively remedy the problem, which is called Mobile Cloud Computing (MCC). Most works on MCC depend on a method to offload functional components at runtime. However, these works only consider the limited verion of offloading to a pre-defined, designated node. Moveover, there is the limitation of managing services subscribed by applications. To provide a comprehensive and practical solution for MCC, in this paper, we propose a self-stabilizing process and its management-related methods. The proposed process is based on an autonomic computing paradigm and works with diverse quality remedy actions such as migration or replicating services. And, we devise a pratical offloading mechanism which is still in an initial stage of the study. The proposed offloading mechanism is based on our proposed MCC meta-model. By adopting the self-stabilization process for MCC, many of the technical issues are effectively resolved, and mobile cloud environments can maintain consistent levels of quality in autonomous manner.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.2
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• pp.168-177
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• 1996

In this paper, we propose an on-line recognition system of chinese characters using an adaptive resonance theory-1(ART-1) neural network. Strokes, primitive components of chinese characters are usually warped into a cursive form and classifying them is very difficult. To deal with such cursive strokes, we use an ART-1 neural network that has the following advantages: (1) it automatically assembles similar patterns together to form classes in a self-organized manner: (2) it directly accesses the recognition codes corresponding to binary input patterns after self-stabilizing; (3) it doesn't tends to get trapped in local minima, or globally incorrect solutions. A database for character recognition also dynamically constructed with generalized character lists, and a new character can be included simply by adding a new sequence to the list. Character recognition is achieved by traversing the chinese datbase with a sequence of recognized strokes and positional relations between the strokes. To verify the performance of the system. We tested it for 1800 daily-used basic chinese second per character. This results suggest that the proposed system is pertinent to be put into practical use.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.9
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• pp.329-340
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• 2020

This study investigates the effect of capital structure on the financial performance of pharmaceutical enterprises which are listing on Vietnam's stock market. The study builds the regression using ROE as dependent variable and four independent variables, including self-financing, financial leverage, long-term asset and debt to assets ratios. In addition, we use other variables as controlling ones, such as firm size, fixed asset rate and growth. We collect data for the period from 2015 to 2019 of all 30 pharmaceutical enterprises which are currently listing on Vietnam's stock market. The least square regression (OLS) is used to test the effect of capital structure to the firms' financial performance. The analysis results show that the financial leverage ratio (LR), long-term asset ratio (LAR) and debt-to-assets ratio (DR) have positive relationship with firm performance, meanwhile the self-financing (E/C) affects negatively to the return on equity (ROE). Upon the findings we suggest that the Vietnamese government should focus on stabilizing macro environment to create favorable environment for enterprises. And the pharmaceutical enterprises should build more reasonable capital structure with higher debt proportion than equity, diversifying loan mobilization channels such as issuing long-term bonds. Additionally, the firms should expand the scale appropriately to maintain development and ability to pay debts.

• Korean Journal of Materials Research
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• v.31 no.1
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• pp.8-15
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• 2021

Transparent, photocatalytic, and self-cleaning TiO2 thin film is developed by TiO2 sol-gel coating on glass and polycarbonate (PC) substrates. Acetyl acetone (AcAc) suppresses the precipitation of TiO2 by forming a yellowish (complex) transparent sol-gel. XPS analysis confirms the presence of Ti2p and O1s in the thin films on glass and PC substrates. The TiO2-sol is prepared by stabilizing titanium (IV) isopropoxide (TTIP) with diethylamine and methyl alcohol. The addition of AcAcsilane coupling solution to the TiO2-sol instantaneously turns to yellowish color owing to the complexing of titanium with AcAc. The AcAc solution substantially improves the photocatalytic property of the TiO2 coating layer in MB solutions. The coated TiO2 film exhibits super hydrophilicity without and with light irradiation. The TiO2 thin film stabilized by adding 8.7 wt% AcAc shows the highest photo-degradation for methylene blue (MB) solution under UV light irradiation. Also, the optimum photocatalytic activity is obtained for the 8.7 wt% AcAc-stabilized TiO2 coating layer calcined at 450 ℃. The thin-films on glass exhibit fast self-cleaning from oleic acid contamination within 45 min of UV-light irradiation. The appropriate curing time at 140 ℃ improves the anti-fogging and thermal stability of the TiO2 film coated on PC substrate. The watermark-free PC substrate is particularly beneficial to combat fogging problems of transparent substrates.