• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.25-29
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• 2001

There are so many researches about the search method for the most compatible dispatching rule to a manufacturing system state. Most of researches select the dispatching rule using simulation results. This paper touches upon two research topics: the clustering method for manufacturing system states using simulation, and the search method for the most compatible dispatching rule to a manufacturing system state. The manufacturing system state variables are given to ART II neural network as input. The ART II neural network is trained to cluster the system state. After being trained, the ART II neural network classifies any system state as one state of some clustered states. The simulation results using clustered system state information and those of various dispatching rules are compared and the most compatible dispatching rule to the system state is defined. Finally there are made two knowledge bases. The simulation experiments are given to compare the proposed methods with other scheduling methods. The result shows the superiority of the proposed knowledge base.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.97-105
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• 2020

This paper explores the impact of capital structure on firm performance in the context of Vietnam. The paper investigates the different effect of capital structure on firm performance in state-owned and non-state enterprises listed on the Vietnam stock market. The panel data of research sample includes 488 non-financial listed companies on the Vietnam stock market for a period of six years, from 2013 to 2018. The Generalized Least Square (GLS) is employed to address econometric issues and to improve the accuracy of the regression coefficients. In this research, firm performance is measured by return on equity (ROE), return on assets (ROA), and earnings per share (EPS). The ratios of short-term liabilities, long-term liabilities, and total liabilities to total assets are proxy for capital structure. Firm sizes, growth rate, liquidity, and ratio of fixed assets to total assets are control variables in the study. The empirical results show that capital structure has a statistically significant negative effect on the firm performance. The result also shows this effect is stronger in state-owned enterprises than non-state enterprises in Vietnam. These evidences provide a new insight to managers of both state-owned and non-state enterprises on how to improve the firm's performance with capital structure.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.6
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• pp.595-602
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• 2008

In this paper, performance of the initial alignment for INS whose attitude is not leveled is investigated. Observability of the initial alignment filter is analyzed and estimation errors of the estimated state variables are derived. First, the observability is analyzed using the rank test of observability matrix and the normalized error covariance of the Kalman filter based on the 10-state model. In result, it can be seen that the accelerometer biases on horizontal axes are unobservable. Second, the steady-state estimation errors of the state variables are derived using the observability equation. It is verified that the estimates of the state variables have errors due to the unobservable state variables and the non-leveling tilt angles of a vehicle containing the INS. Especially, this paper shows that the larger the tilt angles of the vehicle are, the larger the estimation errors corresponding to the sensor biases are. Finally, it is shown that the performance of the 8-state model excepting the accelerometer biases on horizontal axes is better than that of the 10-state model in the initial alignment by simulation.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.115.1-115.1
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• 2012

The Ultraviolet Coronagraph Spectrometer on board the Solar and Heliospheric Observatory (SOHO) observes low ionization state coronal mass ejection plasma at ultraviolet wavelengths. The CME plasmas are often detected in O VI ($3{\times}10^5K$), C III ($8{\times}10^4K$), $Ly{\alpha}$, and $Ly{\beta}$. Earlier in situ observations by the Solar Wind Ion Composition Spectrometer (SWICS) on board Advanced Composition Explorer (ACE) have shown mostly high ionization state plasmas in interplanetary coronal mass ejections (ICME) events, which implies that most CME plasma is strongly heated during its expansion in solar corona. In this analysis, we investigate whether the low ionization state CME plasmas observed by UVCS occupy small enough fractions of the CME volume to be consistent with the small fraction of ICMEs measured by ACE that show low ionization plasma, or whether the CME must be further ionized after passing the UVCS slit. To do this, we determine the covering factors of low ionization state plasma for 10 CME events. We find that the low ionization state plasmas in CMEs observed by UVCS show small covering factors. This result shows that the high ionization state ICME plasmas observed by the ACE results from a small filling factor of cool plasma. We also find that the low ionization state plasma volumes in faster CMEs are smaller than in slower CMEs. Most slow CMEs in this analysis are associated with a prominence eruption, while the faster CMEs are associated with X-class flares.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.63-67
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• 2001

The photophysical properties and the singlet oxygen generation efficiency of tetrathiarubyrin have been investigated to elucidate the possibility of its use as a photodynamic therapy (PDT) photosensitizer by steady-state and time-resolved spectroscopic methods. The observed photophysical properties were affected by various molecular aspects, such as extended ${\pi}conjugation$, structural distortion, and internal heavy atom. The steady-state electronic absorption spectrum was red-shifted due to the extended $\pi-conjugation$, and the spin orbital coupling was enhanced by the structural distortion and the internal heavy atom effect. As a result of the enhanced spin orbital coupling, the triplet quantum yield increased to 0.90 $\pm$ 0.10 and the triplet state lifetime was shortened to 7.0 $\pm$ 1.2 ${\mu}s$. Since the triplet state decays at a relatively faster rate, the efficiency of the oxygen quenching of the triplet state decreases. The singlet oxygen quantum yield was estimated to be 0.52 $\pm$ 0.02, which is somewhat lower than expected. On the other hand, the efficiency of singlet oxygen generation during the oxygen quenching of triplet state, $f{\Delta}^T$, is near unity. Such high efficiency of singlet oxygen generation can be explained by the following two possible factors: The hydrogen bonding of ethanol which impedes the deactivation pathway of the charge transfer complex with oxygen to the ground state, the less probability of the aggregation formation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.283-284
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• 2019

In the last decades patient's suffering with Parkinson's disease is increasing at a rapid rate and as per prediction it will grow more rapidly as old age population is increasing at a rapid rate through out the world. As the performance of wearable sensor based approach reached to a new height as well as powerful machine learning technique provides more accurate result these combination has been widely used for assessment of various neurological diseases. ON state is the state where the effect of medicine is present and OFF state the effect of medicine is reduced or not present at all. Classification of ON/OFF state for the Parkinson's disease is important because the patients could injure them self due to freezing of gait and gait related problems in the OFF state. in this paper wearable sensor based approach has been used to collect the data in ON and OFF state and machine learning techniques are used to automate the classification based on the gait pattern. Supervised machine learning techniques able to provide 97.6% accuracy while classifying the ON/OFF state.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.152-155
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• 2006

The purposes of this study were to examine the influence of competitive state anxiety on outcome of games, therefore furnish practical information on sports coach. The Subjects of this study were sampled 200 bowling athletes using the stratified cluster random sampling. The data collected questionnaire designed for this study were consisted of Competitive State Anxiety Inventory-2: CSAI-2 of Martens(1990). Statistics employed in this study to data analysis was regression analysis. Based on the result of the study, the following conclusions appear warranted: 1. Competitive state anxiety of bowling athletes were influence on result ranking. 2. Competitive state anxiety of bowling athletes were influence on average score.

• Journal of Korean society of Dental Hygiene
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• v.10 no.5
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• pp.841-849
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• 2010

Objectives : This purpose of this study was to examine worker's Dental care utilization patterns and its related factors, to prepare basic data for oral health promotion of workers. Methods : The study subject were 1016 industrial workers from7 working places in Gyung-Sang-Buk Do and Daegu-City. Data for this study was obtained by self-administrated questionnaire. The questionnaire consists of general characteristics, yes or no of dental care utilization before six month, purpose of visit, yes or no of dental disease form the results of dental examination screening before one years, yes or no of and patterns dental care utilization of workers with dental disease, etc. The data was utilized using frequency test and $x^2-test$. Results : Rate of dental care utilization was 40% within six month last, among the general characteristics, it were statistically significant that higher age, married state, bad oral health state, high Work period. Rate of dental disease as a result of their dental examination last was 53.1% among the general characteristics, it were statistically significant that enough economic state, bad oral health state, blue collar work type. Dental care utilization's rate of dental disease as a result of their dental examination last was 48.6% among the general characteristics, it were statistically significant that Enough economic state, higher age, married state, high Work period. Conclusions : In order to promote workers of abnormal opinions to take the medical treatment on their dental diseases later dental examination, it is necessary to educate them consistently for the importance of early medical treatment.

• ETRI Journal
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• v.15 no.3
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• pp.1-26
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• 1994

Simulated annealing is an attractive, but expensive, heuristic method for approximating the solution to combinatorial optimization problems. Attempts to parallel simulated annealing, particularly on distributed memory multicomputers, are hampered by the algorithm's requirement of a globally consistent system state. In a multicomputer, maintaining the global state S involves explicit message traffic and is a critical performance bottleneck. To mitigate this bottleneck, it becomes necessary to amortize the overhead of these state updates over as many parallel state changes as possible. By using this technique, errors in the actual cost C(S) of a particular state S will be introduced into the annealing process. This paper places analytically derived bounds on this error in order to assure convergence to the correct optimal result. The resulting parallel simulated annealing algorithm dynamically changes the frequency of global updates as a function of the annealing control parameter, i.e. temperature. Implementation results on an Intel iPSC/2 are reported.

• International Journal of Control, Automation, and Systems
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• v.6 no.6
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• pp.960-967
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• 2008

This paper shows that design of a robustly stable repetitive control system is equivalent to that of a feedback control system for an uncertain linear time-invariant system satisfying the well-known robust performance condition. Once a feedback controller is designed to satisfy the robust performance condition, the feedback controller and the repetitive controller using the performance weighting function robustly stabilizes the repetitive control system. It is also shown that we can obtain a steady-state tracking error described in a simple form without time-delay element if the robust stability condition is satisfied for the repetitive control system. Moreover, using this result, a sufficient condition is provided, which ensures that the least upper bound of the steady-state tracking error generated by the repetitive control system is less than or equal to the least upper bound of the steady-state tracking error only by the feedback system.