• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.200-201
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• 2002

Recently, a countermeasure for the electromagnetic noise emission on RF integrated transmission line using the loss generation of ferromagnetic thin films is briefly suggested$\^$1,2/. Without the magnetic film, the noise harmonics of the signal pass through the transmission line with only a little attenuation. The ideal role of magnetic film is not to raise insertion losses in the pass-band and to give as large attenuation as possible to eliminate the noise harmonics at the stop-band, the frequency range higher than the meaningful signal as shown in Fig. 1. and Fig. 2. (omitted)

• Journal of Communications and Networks
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• v.14 no.1
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• pp.27-33
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• 2012

In this paper, a new blind signal processing scheme for equalization in fading and impulsive-noise channel environments is introduced based on probability density functionmatching method and a set of Dirac-delta functions. Gaussian kernel of the proposed blind algorithm has the effect of cutting out the outliers on the difference between the desired level values and impulse-infected outputs. And also the proposed algorithm has relatively less sensitivity to channel eigenvalue ratio and has reduced computational complexity compared to the recently introduced correntropy algorithm. According to these characteristics, simulation results show that the proposed blind algorithm produces superior performance in multi-path communication channels corrupted with impulsive noise.

• The Journal of the Acoustical Society of Korea
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• v.30 no.4
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• pp.207-214
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• 2011

Human auditory acuity decreases naturally due to aging. But recently cases of impaired hearing at a young age are increasing greatly. The biggest reason for such an increase of population with impaired hearing is popularization of various kinds of portable multimedia appliances. Many studies on impaired hearing due to noises caused by the earphone and headphone are being made, but there are few studies on noise-impaired hearing caused directly by mobile phone communication. Based on a precedent inquiry, this study proposes a technique for preventing noise-impaired hearing applying to an active noise reduction technique onto bone conduction speaker. This technique is a method for reducing noises by antiphase oscillation through bone conduction speaker with ambient noises. If the proposed system is applied, the noise level that is actually introduced to audition decreases by more than 12 dB, and such a decreased amount of sound volume fundamentally prevents the factors of noise-caused hearing difficulty due to mobile phone communication. Sensibility test results showed that adequate communication was possible even in such a situation where communication volume was decreased like this.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.5
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• pp.961-968
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• 2007

Today, we can use radio communication device anywhere-anytime. Sometimes, we use the device in acoustic noise environment. The acoustic noise makes many problems in communication system. In acoustic noise environment, speaker cannot send clear information to receiver, because the received signal includes both speech signal and noise signal. A digital filter is useful to remove noise to get desired signal. One of methods is the adaptive digital filter using the adaptive noise canceller that automatically adjust filter parameters. This thesis addresses articulation algorithms against actual acoustic noises by means of two adaptive filtering methods. One is the adaptive noise canceller with two input channels and another is the spectral subtraction filter with one input channel. The experimental result from the proposed filter shows that the adaptive noise canceller is useful to reduce the non-stationary noises, while the spectral amplitude filter is effective for stationary noises.

• Journal of information and communication convergence engineering
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• v.1 no.1
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• pp.35-38
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• 2003

Analyses of performance of wireless broadband communication systems employing fiber-optic link have presented. We have analyzed CNR penalty to evaluate system performance by taking into account, radio link considering rainfall attenuation, and optical link considering several carrier-to-noise ratio versus the optical modulation index.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.168-172
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• 2003

This paper analyzes the output noise and the noise figure of common source MOSFET pair each input of which is separately driven in the different frequencies. This analysis is performed for concurrent dual band cascode CMOS LNA with double inputs and single output fabricated in $0.18{\mu}m$ CMOS process. Since both inputs and output are matched to near $50{\Omega}$ using on-chip inductors, the measured noise figures are much higher than those of usual CMOS LNA. But, the main concern of this paper is focused on the added noise features due to the other channel common source stage. The dual-band LNA results in noise figure of 4.54dB at 2.14GHz and 6.03dB at 5.25GHz for selectable operation and 7.44dB and 6.58dB for concurrent operation. The noise analysis explains why the added noise at each band shows so large difference.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1643-1647
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• 2003

This paper, we propose a new high noise immunity phase-locked loop(PLL) which can suppress the high incident noise coupling with large amplitude and long period to the input frequency of PLL and keeps constant frequency and phase of the VCO output for providing the high stability distribution clock pulse.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1881-1884
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• 2003

In some requirements of dc motor drive circuit applications are high quality output with generation of low internal conducted EMI. However the conventional dc motor drive circuits have been usually using unbalanced circuit which generates the high conducted EMI to the frame ground. This paper presents a balanced dc motor drive circuit which is effective way to reduce the common-mode noise. The circuit balancing is to make the noise pick up or occurring in both conductor lines, signal path and return path is equal in amplitude and opposite phase so that it will cancel out in the frame ground. The common-mode conducted noise reduction of this proposed dc motor drive is confirmed by experimental results.

• Journal of Sensor Science and Technology
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• v.21 no.6
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• pp.429-433
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• 2012

In this paper, we reduced the optical noise interference in a visible light communication system using two color LEDs. In the transmitter, the original and the inverted signals of the transmitted data modulated a red LED and a blue LED, respectively. In the receiver, a differential detector which is composed of two photodetectors and an optical red filter detected the mixed signal radiated from the two LEDs. In an environment that the optical noise from a fluorescent lamp exists, the signal-to-noise ratio in this system was improved by about 20dB compared to that in the conventional system which uses a single LED and a single photodetector.

• Journal of Korea Multimedia Society
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• v.21 no.11
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• pp.1317-1326
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• 2018

A common treatment for tinnitus rehabilitation is to use a device called a sound generator to continuously supplying the sound stimuli. The devices usually provides a sound called white noise, or pink noise, which are common in nature. In this paper, we developed a mobile system for tinnitus diagnostics and therapy using Android mobile applications. The first step for tinnitus diagnostics is detecting an exact tinnitus frequency of the patients, therefore we provide a bark scale tinnitus detection algorithm for fast and accurate diagnostics. Also, the system can provide various stimuli sounds including white noise, pink noise, brown noise, nature sounds, and binaural beats. Also we provides the therapeutic functions through questionnaires to solve existing problems of the patients.