• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.177-186
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• 1996

A convolution alogorithm combined with Fourier transformation is applied to the tomographic reconstruction of the asymmetric spray structure to identify the local drop size and volume concentration. The line of sight intergrated data from Malvern particle analyzer with multiangular scanning form a basic information for the deconvolution. Linear interpolation is tested to obtain the effect of increasing number of scanning angles. This transformation method predicts well the structure of asymmetric spray. The tehnique can be extended to other line of sight combustion diagnostics.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.2
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• pp.300-305
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• 2017

In this paper, we performed a evaluation for angular and energy dependence of military radiation detector PDR-1K. Its measuring range is divided into two section, low and high, and each range has a GM tube separately owing to broad scale. We observed a change in relative angular reactivity within 0.928 ~ 1.188 in low range and within 0.743 ~ 1.000 in high range from $-90^{\circ}$ to $+90^{\circ}$. The evaluation for energy dependence appeared a relative reactivity within 0.892 ~ 1.000 above 83 keV. This means PDR-1K isn't possible to use below 83 keV of radiation energy. It is possible to provide response information to user and to increase reliability of radiation measurement through this paper.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.12
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• pp.20-26
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• 1999

In this paper, a multiple target angle tracking algorithm that can avoid data association problem and has a simple structure is proposed by obtaining the angular innovation of the targets from a signal subspace. The signal subspace is recursively estimated by a signal subspace tracking algorithm, such as PAST. A nonlinear matrix equation which satisfy the estimated signal subspace and the angular innovation is induced and expanded into a Taylor series for linear approximation. The angular innovation is obtained by solving the approximated linear matrix equation in the least square sense. The good performance of the proposed algorithm is demonstrated by various computer simulations.

• Journal of Multimedia Information System
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• v.5 no.2
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• pp.121-130
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• 2018

We developed multimedia esophageal catheters for use with birds to measure and record ECG and angular velocity while anesthesized, at rest, and in flight. These catheters enable estimates of blood pressure based on readings given by an angular velocity sensor and by RR intervals of ECG affected by EMG. In our experiments, the catheters had the following characteristics: 1. Esophageal catheters offer a topological advantage with 8-dB SNR improvement due to elimination of electromyography (EMG). 2. We observed a very strong correlation between blood pressure and the angular velocity of esophageal catheter axial rotation. 3. The impulse conduction pathway (Purkinje fibers) of the cardiac ventricle has a direction opposite to that of the mammalian pathway. 4. Sympathetic nerves predominate in flight, and RR interval variations are strongly suppressed. The electrophysiological data obtained by this study provided especially the state of the avian autonomic nervous system activity, so we can suspect individual's health condition. If the change of the RR interval was small, we can perform an isolation or screening from the group that prevent the pandemics of avian influenza. This catheter shall be useful to analysis an avian autonomic system, to perform a screening, and to make a positive policy against the massive infected avian influenza.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.2
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• pp.103-112
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• 2011

This paper proposes a new fuzzy speed controller for the precise speed control of a permanent magnet synchronous motor(PMSM). The proposed control system needs the information of the angular acceleration instead of the load torque, so the third-order fuzzy acceleration observer estimates it. Moreover, the LMI conditions are derived for the existence of the fuzzy acceleration observer and fuzzy speed controller, and the gain matrices of the observer and controller are obtained. It is analytically proven that the proposed observer-based fuzzy speed regulator is exponentially stable. To evaluate the performance of the proposed control algorithm, experimental results as well as simulation results are provided under the conditions of motor parameter and load torque variations. Finally, it is clearly confirmed that the proposed control method can accurately control the speed of a PMSM.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.353-357
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• 2010

In general, the information of inertia properties is required to control a spacecraft. The inertia properties are changed by some activities such as consumption of propellant, deployment of solar panel, sloshing, etc. Extensive estimation methods have been investigated to obtain the precise inertia properties. The gyro-based attitude data including noise and bias needs to be compensated for improvement of attitude control accuracy. A modified estimation method based on the law of conservation of angular momentum is suggested to avoid inconvenience like filtering process for noise-effect compensation. The conventional method is modified and beforehand estimated moment of inertia is applied to improve estimation efficiency of product of inertia. The performance of the suggested method has been verified for the case of STSAT-3, Korea Science Technology Satellite.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.5
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• pp.67-74
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• 1997

In this paper, we psresent a new scheme to synthetically generate a HPO digital hologram for a three-dimensional image that is modelled as the horizontally stacked two-dimensional images. The proposed method transforms a lightwave field into the angular spectrum of planewaves, which enables this method to use FFT routines, rather than using numerous arithmetic calculations. Hence, this method may be able to not only lead to the dramatically less computation but provide relatively excellent performances due to the phase error-free transformation. We present sampling constraints and implementaton procedure to obtian a hololine for each image and also point out the necessity of interpolation. Simulatioj results are presented to show the comparison with the conventional method in terms of computation time and performances, including the behaviors resulting form the different selection of parameter values to be used in the interpolations.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.286-289
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• 2003

In this paper, the performance of W-CDMA system with smart antenna is analyzed for angular spread in spatio-temporal wideband vector channel. We consider correlation between any two elements of antenna array, the angle spread of multipath, and structure of antenna array in this channel model. And each multipath is assumed as a reflective wave from only one direction. Several multipaths within one chip are distinguished into each one and the strongest signal is selected. As a result, the performance of the W-CDMA system with smart antenna in spatio-temporal wideband vector channel has been considerably improved in proportion to the increase of angular spread.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.155-160
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• 2008

Using a three-dimensional (3-D) FE analyses, this paper provides the shape optimization of the standard test specimen for the torsion test, as well as a method for analyzing effects of misalignment under the angular and concentric misalignment. For verification, FE analysis is performed, which is designed for the perfectly full-model. To optimize the design shape of the torsion-controlled fatigue test specimen, we performed sensitivity analysis using shape parameters. Additionally, two kinds of misalignment (angular misalignment and concentric misalignment) are applied to the circular and tubular specimens to show effects of misalignments in the FE analysis. The present results will provide valuable information for designing shafts for every kind of mechanical system under torsional force.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.74-79
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• 2012

Scalar quantification of the angular prediction error covariance matrix is considered for characterizing tracking performances in phased array radar tracking. Specifically, the maximum eigenvalue and the trace of the covariance matrix are examined in terms of consistency in parameterizing the probability of detection, taking antenna beam-pointing losses into account, and it is shown numerically that the latter is more consistent.