• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.130-132
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• 2013

This paper presents an improvement for calculating method of astronomical vessel position with circle of equal altitude equation based on using a virtual object in sun and two stars observation. In addition, to enhance the accuracy of ship position achieved from solving linear matrix system, and surmount the disadvantages on rank deficient matrices situation, the authors used singular value decomposition (SVD) in least square method instead of normal equation and QR decomposition, so, the solution of matrix system will be available in all situation. As proposal algorithm, astronomical ship position will give more accuracy than previous methods.

• Journal of the Korean Chemical Society
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• v.6 no.2
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• pp.162-170
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• 1962

The rearrangement reaction of azoxybenzenes into hydroxyazobenzenes in strongly acidic solution has been studied by an U. V. spectrophotometric method and by isolation of the rearranged compound. In all cases under investigation, it appeared that the oxygen atom in the azoxy group migrated to the unsubstituted ring, depending neither on the substituent already present in the other ring, nor on the distance between the oxygen atom and the eligible position; whereas, the position in the open ring, ortho or para, to which the oxygen migrates depends on the substituent already present in the other ring. In all compounds besides ${\alpha}$-and ${\beta}$-4-methyl azoxybenzene, the oxygen atom migrates to the para position. In the case of ${\alpha}$ and ${\beta}$-4-methylazoxybenzene, the oxygen atom migrates to the ortho position of the unsubstituted ring.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.110-114
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• 2002

Generally, brushless DC motor(BLDCM) driving system uses hall sensors or encoders as the mechanical position or speed sensors. It is necessary to achieve the informations of rotor position for driving trapezoidal type brushless DC motor without any position sensor. This paper proposes a sensorless driving system with rotor absolute position detector circuit which acquires both commutate phase and commutate time by analyzing motor phase voltages. Proposed system is applied to a 10k[W] rating motor which actually used in electrical vehicles of HONDA co.,ltd. The experimental results will show the validity of the proposed system and the practical use of proposed sensorless drive algorithm.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.129-132
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• 2002

The first purpose of this paper is to develop the sensorless drive at adjustable speed without any mechanical position or speed sensor. For this, this research analyzes terminal voltage, finds the rotor position information and makes the source of commutations of phase current. The second purpose is to propose the sensing method of initial rotor position without instantaneous rotating. Experimental results show the validity and practical use of the proposed sensing method.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.109-115
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• 2009

Many isolated word recognition systems may generate non-similar words for recognition candidates because they use only acoustic information. In this paper, we investigate several techniques which can exclude non-similar words from N-best candidate words by applying Levenstein distance measure. At first, word distance method based on phone and syllable distances are considered. These methods use just Levenstein distance on phones or double Levenstein distance algorithm on syllables of candidates. Next, word similarity approaches are presented that they use characters' position information of word candidates. Each character's position is labeled to inserted, deleted, and correct position after alignment between source and target string. The word similarities are obtained from characters' positional probabilities which mean the frequency ratio of the same characters' observations on the position. From experimental results, we can find that the proposed methods are effective for removing non-similar words without loss of system performance from the N-best recognition candidates of the systems.

• Korean Journal of Oriental Medicine
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• v.16 no.1
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• pp.157-171
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• 2010

This study aimed to investigate the effect of four common types of Qigong position (standing, sitting, supine, and horse-riding position) on the autonomic nervous system. Thirty healthy subjects participated in this study once a week for four weeks. Electroencephalogram (EEG) was measured three times (before, during, and after the position) while the subject maintained one of four positions for ten minutes. There were significant changes in HRV components compared with EEG power spectra in the standing position. Especially, the ratio of low-to-high frequency (LF/HF) which represents a state of balance of autonomic nervous system was increased. In the sitting position, $\beta$ wave which reflects a state of alert consciousness was increased and both the sympathetic and parasympathetic nerves were activated. On the other hand, in the spine position, $\theta$ wave which signifies a state of relaxation was increased and heart rate (HR) was decreased. Activation of sympathetic and parasympathetic nerves was also observed in this position. Significant increases of indices related to awakening and concentration were observed accompanied by increase of HR and a sympathetic nerve was activated in the riding-horse position. In the present study, it was shown that each Qigong position caused various and significant changes in autonomic nervous system. It would be expected that these results can be applied in the choice of appropriate Qigong position according to objective of Qigong therapy although it is remained to further evaluate the effects of long-term maintenance of Qigong positions and repeated Qigong training.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.432-438
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• 2005

In this paper, the high precision position control of AC Servo motor for semiconductor equipment is studied. The control system was implemented using TI DSP TMS320F2812 which has 150 MIPS speed for next generation motor control. The controlled 100W PMSM motor has 2,500 ppr optical incremental encoder. The control system has speed controller and current controller to control the motor position. The encoder pulses are divided into 4 times, which has 10,000 ppr and the motor system has the position accuracy of 1/10,000. If the resolution of the encoder is increased, the resolution of the position control will be increased.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.878-881
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• 2003

To acquire an appointed speaker's clear voice signal from inspect-camera, picture-conference or hands free microphone eliminating interference noises needs to be preceded speaker's position automatically. Presumption of sound source position's basic algorithm is about measuring TDOA(Time Difference Of Arrival) from reaching same signals between two microphones. This main project uses ADF(Adaptive Delay Filter) [4] and CPS(Cross Power Spectrum) [5] which are one of the most important analysis of TDOA. From these analysis this project proposes presumption of real time sound source position and improved model NI-ADF which makes possible to presume both directions of sound source position. NI-ADF noticed that if auditory sense of humankind reaches above to some specified level in specified frequency, it will accept sound through activated nerve. NI-ADF also proposes practicable algorithm, the presumption of real time sound source position including both directions, that when microphone loads to some specified system, it will use sounds level difference from external system related to sounds of diffraction phenomenon. In accordance with the project, when existing both direction adaptation filter's algorithm measures sound source, it increases more than twice number by measuring one way. Preserving this weak point, this project proposes improved algorithm to presume real time in both directions.

• New & Renewable Energy
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• v.4 no.4
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• pp.3-9
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• 2008

In design PV (photovoltaic) system, there are many important factors to consider for best site selection. It is essential to understand to know the amount of sunlight available and how to minimize the shadings. This study presents basic concepts for understanding sun's position and insolation. also it gives easy tools for topography analysis. Finally, this study shows some theoretical calculations of power generation losses by topographic obstacle's elevations and disadvantages in economic feasibility, that is about 7million won loss per year for case of 10 degree topography elevation with assuming average Korea's topography elevation as 5 degree.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.87-90
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• 2008

In design PV(photovoltaic) system, there are many important factors to consider for best site selection. It is essential to understand to know the amount of sunlight available and how to minimize the shadings. This study presents basic concepts for understanding sun's position and insolation. also gives easy tools for topography analysis. Finally, this study shows some theoretical calculations of power generation losses and disadvantages in economic feasibility.