• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.59-62
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• 2009

In general, as a dynamic range of digital still camera is narrower than a real scene‘s, it is hard to represent the shadow region of scene. Thus, multi-scaled retinex algorithm is used to improve detail and local contrast of the shadow region in an image by dividing the image by its local average images through Gaussian filtering. However, if the chromatic distribution of the original image is not uniform and dominated by a certain chromaticity, the chromaticity of the local average image depends on the dominant chromaticity of original image, thereby the colors of the resulting image are shifted to a complement color to the dominant chromaticity. In this paper, a modified multi-scaled retinex method to reduce the influence of the dominant chromaticity is proposed. In multi-scaled retinex process, the local average images obtained by Gaussian filtering are divided by the average chromaticity values of the original image in order to reduce the influence of dominant chromaticity. Next, the chromaticity of illuminant is estimated in highlight region and the local average images are corrected by the estimated chromaticity of illuminant. In experiment, results show that the proposed method improved the local contrast and detail without color distortion.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.251-258
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• 2019

This study proposed a system that can improve the employment rate and maintenance employment rate by filtering information related to employment in analyzing big data for students who want to find employment. The subject was a two-year female university, the existing employment strategy participated in the job search with simple information such as school grades and personality. As a result, the maintenance employment rate was relatively low due to the decrease in the satisfaction of students seeking employment and the incompatibility with the post-employment aptitude. In order to solve these problems, we propose a system that determines and filters whether the input data in the process of analyzing big data such as employment-related information to improve employment and maintenance employment rates.

• Korean Journal of Computational Design and Engineering
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• v.20 no.2
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• pp.159-170
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• 2015

Radio-Frequency Identification (RFID) or Near Field Communication (NFC) technology has many advantages over other visual interfaces since it does not require line-of-sight alignment, can identify multiple tags simultaneously, and does not destroy the integrity of original objects. In addition, smart devices such as smartphone and smartpad have NFC/RFID readers which can provide mobile and natural interactions with digital and physical contents. Augmented reality has an excellent visual interaction capability with digital contents in a real environment by embedding digital contents into the physical world. In this paper, we propose a new approach to digital content interactions using RFID/NFC-based tangible interfaces in augmented reality environments that utilize invisible interfaces in addition to marker-based visual interfaces. By combining the advantages of invisible and visual interfaces, more intuitive interactions with digital contents can be provided, which can remove the difficulty of using typical AR paddles that are widely used in AR interactions. In particular, a semantic AR ontology is defined to provide more convenient interactions. Through the semantic ontology-based inferencing, physical querying and filtering are effectively supported. We will show the effectiveness and advantage of the proposed approach by demonstrating implementation results.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.4
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• pp.175-181
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• 2015

In this paper, we propose a design method for a digital filter using software in order to analyze the radio astronomy observation data. Recently the analysis method for radio astronomy observing system is transferring from hardware to software by developing of state-of-the-art of computer system. The existing hardware system is not able to easily change the specification because it is implemented to meet special requirements and it takes a high cost and time. In case of software, however, it has an advantage to implement with small cost if open software is used, and flexibly changes to satisfy the desired specification. But, in order to analyze the massive data like radio astronomy with software, the good performance system is needed for computer. Therefore, this paper proposes a digital filter design method using software with the same performance as that of digital filter implemented with hardware in observation system which is operated by the KVN(Korean VLBI Network). To design a digital filter, the proposed method is performed with standard C language and the simulation is conducted with GNU(GNU's Not Unix) Octave and investigated to show its effectiveness. In addition, for the high speed operation of the designed digital filter, the SSE(Streaming SIMD Extensions) library is adopted for available parallel operation. By the proposed digital filter, the digital filtering is performed for the wide band observation data in the KVN observation mode, the filtering result of narrow band observation has no ripple inside of stop band, and confirmed the effectiveness of the proposed method.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.10
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• pp.35-41
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• 1993

In this paper, a new speech enhancement method for speech signal corrupted by environmental noise is proposed. Two signals are obtained from the microphone and from the accelerometer attached to the neck, respectively. Since two signals are generated from same source signal, both signals are closely correlated. And environmental noise has no effect on the accelerometer signal. The speech enhancement system identifies the optimum linear system between two signals on the basis of the dependence between the signals. The enhanced speech can be obtained by filtering the noise-free accelerometer signal. Since the characteristcs of the speech signal and environmental noise are changing with time, adaptive filtering system has to be used for characterizing the time-varing system. Simulation results show 7dB enhancement with 0dB speech signal level relative to the white noise.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1039-1042
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• 1995

In real time application such as motion control, it is hard to find the application of non-causal filtering due to its need for future position data, even though it shows wide usage in off-line digital signal processing. Recently, some of motion control areas such as learning and repetitive control use non-causal filtering technique in their application. these kinds of zero-lag non-causal filter application are very usful not only to reduce the machine vibration, but also to increase control accuracy with comparatively less work. In this paper, genuine method to implement zero-lag non-causal filter in a CNC is introduced. Also the variation of this implementation for the learning operation is suggested to give the NC better control performance for a specific job. By adopting the new NC architecture call Soft-NC, all these implementions are made possible here, and especially large memory requirement which hinders their usage for many years is no longer barrier in their real world application.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.445-449
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• 1988

Digital processing of measured data offers a powerful means to improve the resolution and quality of ultrasonic imaging. The present research demonstrates that filtering typical B-scan images using Wiener filter enhances lateral resolutions by more than 50 percent. The filter is operated using the measured signal amplitude across the transmitter beam and the beam with. It is optimized for low noise and high resolution By an empirical approach. This bethod for lateral filtering produces a very useful result for the line images with high interference by neighboring lines.

• 한국디지털정책학회:학술대회논문집
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• 2004.05a
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• pp.195-204
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• 2004

Due to growth of diversified media, content screening is the definite procedures. The procedures of screening varies from country by country in various reasons. Therefore, reason of conducting such study is to compare & contrast screening process by countries. In order to clarify definition of terms that measures screening, "censorship" means "legislative filtering process prior to public appearance". In contrary "Rating and/or Classification" is defined opposite of it. After defining these terms, Screening is dignified into two distinctive measures, which are "legislative intereference" and "voluntary notification". Those two measures are again sub-categorized into eight distinctive operational definition. Utilizing those distinctive measures, our study has concluded as US, Japan and some laissez-faire countries use "voluntary notification" systems but in contrast China and Brunei use "legislative filtering" system.? Korea and Australia uses unique combination of both system. In order for Korea to adopt "voluntary notification system", legislative intereference must be weaken and develop strong "voluntary notification" system.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.439-441
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• 2005

A kernel regression filter with adaptive bandwidth is developed and successfully applied to digital reactivity meter for neutron signal measurement in nuclear reactors. The purpose of this work is not only reduction of the measurement noise but also the edge preservation of the reactivity signal. The performance of the filtering algorithm is demonstrated comparing with well known smoothing methods of conventional low-pass and bilateral filters. The developed method gives satisfactory filtering performance and edge preservation capability.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.2
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• pp.101-106
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• 2008

The speech signal has been put into a form suitable for storage and analysis by computer, several different operation can be performed. Filtering, sampling and quantization are the basic operation in digiting a speech signal. The waveform can be displayed, measured and even edited, and spectra can be computed using methods such as the Fast Fourier Transform (FFT), Linear predictive Coding (LPC), Cepstrum and filtering. The digitized signal also can be used to generate spectrograms. The spectrograph provide major advantages to the study of speech. So, author introduces the basic techniques for the acoustic recording, digital signal processing and the principles of spectrum and spectrogram.