• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.5
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• pp.18-24
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• 2010

In this paper, a new matrix decoding system using vector based Virtual Source Location Information (VSLI) is proposed as an alternative to the conventional Dolby Pro logic II/IIx system for reconstructing multi-channel output signals from matrix encoded two channel signals, Lt/Rt. This new matrix decoding system is composed of passive decoding part and active part. The passive part makes crude multi-channel signals using linear combination of the two encoded signals(Lt/Rt) and the active part enhances each channel regarding to the virtual source which is emergent in each inter channel. Since the virtual sources are related to the perceptual sound images in virtual sound field, the reconstructed multi-channel sound results in good dynamic perception and stable image localization. Moreover, the good channel separation is maintained with nonlinear trigonometric enhancing function.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.532-537
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• 2009

The necessity of intelligent surveillance system is gradually considered seriously from the space where the security is important. In this paper, we embodied unmanned intelligent system by developing embedded mobile robot based on images and sounds tracking. For objects tracking, we used block-matching algorithm and for sound source tracking, we calculated time differences and magnitude dissimilarities of sound. And we demonstrated the superiority of intruder tracking algorithm through the embodiment of Pan-Tilt camera and sound source tracking module using system, Network camera and mobile robot using system and mobile robot using system. By linking security system, the suggested system can provide some interfacing functions for the security service of the public facilities as well as that of home.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.76.1-76.1
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• 2019

After the first identification of electromagnetic counterpart of gravitational wave source (GW170817), era of multi-messenger astronomy has begun. For specifying coordinate, magnitude, and host galaxy information, optical follow-up observation of GW source becomes important. The O3 run of LIGO / VIRGO started after April 2019. We present searching strategy of GW optical counterpart using the KMTNet. By performing tiling observation of high probability area in GW localization map, we expect to observe early light-curve of GW optical counterpart. We will also present observation result for three gravitational wave events of binary black hole mergers. After identification of optical counterpart, we will study collision mechanism, progenitor, and characteristics of host galaxy using observation data of GW source.

• The Journal of the Acoustical Society of Korea
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• v.23 no.4
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• pp.324-324
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• 2004

Sound localization can be controlled by simulating the transfer functions from sound source to listener's ears. Even by using this method. a good performance cannot be expected when a listener slightly moves from the position where the transfer functions were measured. We have already been proposed the multi-point control method to overcome the problem of the listener's small movement. In this method, the transfer functions are simulated at multiple points around the listner's ears so that the points forms an area which covers the small movement of the listener. In this paper. we investigated the effect of applying multi-point control method for the control of sound localization. Results show that multi-point control is effective to keep the perceptual error of the localized direction small when the listener moves up to 6 cm from the original position.

• The Journal of the Acoustical Society of Korea
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• v.39 no.3
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• pp.163-169
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• 2020

The asynchronous bistatic sonar needs to estimate direct blast arrival time at a receiver to localize targets, and therefore the direct blast arrival time estimation error could be added to target localization error in comparison with synchronous system. Direct blast especially appears as several peaks at the matched filter output by multipath, thus we compared the first peak detection technique and the maximum peak detection technique of those peaks for direct blast arrival time estimation through sea trial data. The test was performed in a shallow sea with bistatic sonar made up of spatially separated source and line array sensors. Line array sensors obtained the target signal which is generated from the echo repeater. As a result, the first peak detection technique is superior to maximum peak detection technique in direct blast arrival time estimation error. The result of this analysis will be used for further research of target tracking in the asynchronous bistatic sonar.

• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.846-860
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• 2011

The binaural auditory system of human has ability to differentiate the direction and the distance of the sound sources by using the information which are inter-aural intensity difference(IID), inter-aural time difference(ITD) and/or the spectral shape difference(SSD). These information is generated from the acoustical transfer of a sound source to pinna, the outer ears. We can create a virtual sound system using the information which is called Head related transfer function(HRTF). However the performance of 3D sound is not always satisfactory because of non-individual characteristics of the HRTF. In this paper, we propose the algorithm that uses human's auditory characteristics for accurate perception. To achieve this, excitation energy of HRTF, global masking threshold and loudness are applied to the proposed algorithm. Informal listening test shows that the proposed method improves the sound localization characteristics much better than conventional methods.

• The Journal of the Acoustical Society of Korea
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• v.26 no.5
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• pp.220-226
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• 2007

The two major objectives of acoustical measurements in a cavitation tunnel are measuring the noise levels generated by rotating propellers behind a hull and localizing possible noise sources in order to reduce noise levels. Propeller noise measurement experiments were performed in MOERI cavitation tunnel at December, 2006. In order to put the propeller into cavitating conditions, a wake-generating dummy body was devised. In addition, ten hydrophones are put inside a wing-shaped casing in order to minimize the unexpected flow induced self noise around hydrophone itself. After measuring both of the noises of the rotating propeller behind the dummy body and signals generated by a virtual source, respectively the data were matched field processed using the frequency incoherent Bartlett processor to localize noises on the propeller plane. In this paper, we presented the measured noise analysis and the localization results.

• Korean Journal of Cognitive Science
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• v.14 no.4
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• pp.1-7
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• 2003

The common features of the behavioral inhibition and the action monitoring that are considered as one of the executive functions were investigated using event-related brain potentials (ERPs) and source localization analysis. The electrophysiological correlates of behavioral inhibition and action monitoring ate analyzed when the subjects performed the Go/NoGo task. Two ERP components of behavioral inhibition termed as N200 and P300 in NoGo condition were differ from those of Go condition, that is the amplitudes of NoGo N200 and P300 are largest on the fronto-central region, which may reflect the inhibitory control of frontal lobe required in NoGo condition. The error-related negativity (ERN) observed on the fronto-central region when the subjects committed error was much larger in amplitude and faster in latency than those of the correct-related negativity (CRN), which may indicate that the signal of action monitoring is much more required for the error response. The correlation analysis for the ERP components of behavioral inhibition and action monitoring revealed the significant negative correlation among the latencies of NoGo N200 and P300 and the amplitude of ERN, which may reflects that the faster subjects inhibit response, the more monitor their own action. The close relationship between behavioral inhibition and action monitoring was also supported by the results of source localization analysis, which showed the common neural sources of NoGo N200 and ERN was anterior cingulate cortex.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6425-6431
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• 2015

Invertase, that hydrolyzes sucrose into glucose and fructose, plays a great role in carbohydrate reallocation between the photosynthetic source tissue and various sink tissues. Invertase also occurs in a variety of isoforms for various functions in plants. Insoluble invertases were extracted only in buffer solutions containing high concentrations of salt. Within these classes, acid invertase has an optimum activity at acidic pH (pH 4-5). Induction of insoluble acid invertase (INAC-INV) in leaf, stem, and root tissues in response to physical wounding has been investigated. To detect the localization of INAC-INV within the plant, immunolocalization has been performed. In this study, the accumulation of INAC-INV was noticeable to reach maximum levels on 72 hr after mechanical injuries. INAC-INV was induced in wounded leaves 3 times more than control leaves. Immunolocalization results showed that INAC-INV accumulated in wall appositions and intercellular spaces. INAC-INV was also localized at sieve cell walls in phloem tissues close to the site of wounding. Taken together, this study suggested that INAC-INV induction upon wounding injuries can play a role on responses to the high energy demand for wound healing process.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.575-580
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• 2004

In this work, a method is presented to find an anatomical site of a current source crudely in a standard brain using grand average of MEG data. Minimum norm estimation algorithm and truncated singular value decomposition were applied to calculate the distributed sources that can reproduce the measured signals. Grand average over all subjects was obtained from the transformed signals, which would be detected in a standard sensor plane by the obtained distributed current sources. In the simulation study, it was shown that the localized dipole using the grand average is consistent with the mean location of localized dipoles of all subjects within several mm even with large inter-individual differences of sensor positions. This result suggests that the mean location of low level signal source can be estimated as a dipole source in grand average and it was confirmed in the localization of the current source of N100m. when the localized dipole is registered on a standard brain. This result also suggests that the activity region obtained from grand average can be crudely estimated on a standard brain using the source location of the N100m as a reference point.