• Korean Journal of Remote Sensing
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• v.27 no.4
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• pp.403-410
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• 2011

Consistent observation with high temporal and spatial resolution is required for an efficient monitoring of coastal environments. Remote monitoring system installed on the ground is capable of simultaneous observation of wide coastal area and consistent observation with high frequency, which a small number of in-situ measurements cannot manage. This paper studies two typical ground based coastal monitoring system, marine radar and camera system. Marine radar can produce time series of frequency spectrum by integrating wave number spectrum calculated from spatial and temporal variation of waves in the radar image. The time averaged radar images of waves can analyze wave breaking zone, rip currents and location of littoral bars. Camera system can observe temporal variation of foam generation originated from coastal contamination as well as shoreline changes. By extracting the part of foams from rectified images, quantitative analysis of temporal foam variation can be done. By using the two above systems of different characteristics, synergetic benefit can be achieved.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.465-467
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• 2002

The effects of salicylic acid (SA) on growth and proline were investigated in cucumber seedlings. Exogenous application of SA(100 uM - 1mM) led to a noticeable decrease in root and shoot growth, and dry weights of seedlings. Anatomical observation on leaf anatomy of cucumber revealed that the thickness of all leaf tissue components decreased in SA-treated plants. The effect was most promounced on the width of the adaxial epidermis. In the separate and simultaneous effects of SA and water deficit induced by PEG on growth and proline accumulation, the water deficit treatments had greater effects on growth traits and proline content than SA. Combinations of SA and PEG decreased dry matter and root length, and resulted in higher proline in both shoots and roots than SA stress alone. Shoots had higher proline than roots.

• Biomolecules & Therapeutics
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• v.6 no.1
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• pp.25-30
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• 1998

The roles of dopamine(DA) and N-methyl-D-aspartate(NMDA) system in the development and expression of morphine dependence were investigated by monitoring the concentrations of extracellular DA and its metabolites by in vivo microdialysis and simultaneous observation of behavioral changes in morphine dependent rats. Extracellular DA level in caudate putamen of morphine-dependent rat was decreased and the concentrations of its metabolites, dihydroxy phenylacetic acid(DOPAC) and homovanillic acid(HVA), were increased during naloxone-precipitated withdrawal. DA contents were recovered to normal levels by pretreatment of MK-801, a noncompetitive NMDA receptor antagonist, which may explain the mechanism of diminishing effect of MK-801 on withdrawal symptoms in morphine-dependent rats. MK-801(0.3 mg/tg, i.p.) induced the untoward hamful neurological signs such as ataxia and severe rotations, which may be produced by hyperactivation of dopaminergic system. These results suggest that MK-801 may inhibit the expression of mophine dependence by altering the dopamine release.

• Communications for Statistical Applications and Methods
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• v.26 no.6
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• pp.575-582
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• 2019

The problem of selecting variables in the presence of outliers is considered. Variable selection and outlier detection are not separable problems because each observation affects the fitted regression equation differently and has a different influence on each variable. We suggest a simultaneous method for variable selection and outlier detection in a linear regression model. The suggested procedure uses a sequential method to detect outliers and uses all possible subset regressions for model selections. A simplified version of the procedure is also proposed to reduce the computational burden. The procedures are compared to other variable selection methods using real data sets known to contain outliers. Examples show that the proposed procedures are effective and superior to robust algorithms in selecting the best model.

• Journal of KSNVE
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• v.7 no.1
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• pp.161-168
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• 1997

The present paper describes the vibration control experiment of composite plates with bonded piezoelectric sensor and actuator. The system is modeled as two degree-of-freedom system using modal coordinates and the system parameters are obtained from vibration tests. Kalman filter is adopted for extracting modal coordinates from sensor signal, and control algorithms applied to the system are Linear Quadratic Gaussian(LQG) control, Bang-Bang Control (BBC), Negative Velocity Feedback(NVF), Proportional Derivative Control(PDC). From observation of the spillover and control perfomance, it is concluded that a higher order control algorithm such as LQG rather than BBG, NVF, PDC is suitable for efficient simultaneous control of both bending and twisting modes of composite plates.

• 한국해양학회지
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• v.12 no.2
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• pp.67-74
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• 1977

With the serial observation data and the tidal records at Busan and Izuhara from 1966 to 1973, the geostrophic current velocity and its relation to the difference of mean sea level of both sides were studied in order to estimate indirectly the average current velocity from the tidal observations. The results shows that the current velocity is estimated by the relationship V=4.016(H-98.3) with the 95% confidence limits of V 4.2 cm/sec. Ther relationship between the observed current velocity and the simultaneous daily mean sea level difference shows a similar result, V=4.717(H-99.6). The two equations were applied to the evaluation of annual variations of current velocity from the average monthly mean sea level data of both stations.

• Journal of the Korean Vacuum Society
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• v.12 no.1
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• pp.51-54
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• 2003

The spontaneous oscillations in the optogalvanic signals are observed in negative glow region of Ar hollow cathode discharge. The spontaneous oscillations in the optogalvanic signals are observed at low discharge currents less than about 3 mA. Based on the simultaneous measurements of both the density variation of metastable atoms and emission intensities of the 1s-2p transitions, one of the possible mechanisms for the spontaneous oscillation is considered to be related to the stepwise ionization of the metastable atoms due to collisions with slow electrons in the discharge.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.115-115
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• 2014

First, We will briefly introduce early science results of AGN observations with KVN and KaVA. KaVA is the combined array of the Korean VLBI network (KVN) and VLBI Exploration of Radio Astronomy (VERA). These include KaVA monitoring of M87, Sgr A* and a few bright blazars and KVN Search for circular polarized Blazars. Furthermore, we will present our future plan of monitoring observation of Sgr A* and M87 with KaVA and Low Radio Power AGN multi frequency polarization survey with KVN. Because of the largeness of their centralsuper-massive black holes, we select them as top-priority sources of our key science program (KSP). The main science goals of the KaVA KSP are (1) mapping the velocity field of the M87 jet and testing magnetically-driven-jet paradigm, and (2) obtaining tightest constraints on physical properties of radio emitting region in Sgr A. High sensitivity achieved through simultaneous multifrequency phase referencing technique of KVN will allow us to explore Low Radio Power AGN cores which build majority of AGNs and therefore are important for undestanding the evolution of AGNs and of their hosts.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.161-164
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• 1988

The purpose of this paper is to propose a simple firmware realization of PCM framing system, which exploits LSI memories for performance improvement and hardware simplification. The proposed system simply consists of a tapped delay line for simultaneous observation of in framing-bits and ROM programmed sequence controller for framing process. Perpormance analyses are made in terms of misframe interval, sync-loss-detection time and reframe time. The proposed strategy proved to be significantly better in reframe time, stability and hardware implementation.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.3
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• pp.211-217
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• 2000

A main contribution of this paper is the development of a Hopfield network-based algorithm for the fault diagnosis of the actuators in linear system with uncertainties. An unknown input decoupling approach is introduced to the design of an adaptive observer so that the observer is insensitive to uncertainties. As a result, the output observation error equation does not depend on the effect of uncertainties. Simultaneous energy minimization by the Hopfield network is used to minimize the least mean square of errors of errors of estimates of output variables. The Hopfield network provides an estimate of the gains of the actuators. When the system dynamics changes, identified gains go through a transient period and this period is used to detect faults. The proposed scheme is demonstrated through its application to a simulated second-order system.