• Title/Summary/Keyword: brain noise

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Development of EEG Signals Measurement and Analysis Method based on Timbre (음색 기반 뇌파측정 및 분석기법 개발)

  • Park, Seung-Min;Lee, Young-Hwan;Ko, Kwang-Eun;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.3
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    • pp.388-393
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    • 2010
  • Cultural Content Technology(CT, Culture Technology) for the development of cultural industry and the commercialization of technology, cultural contents, media, mount, pass the value chain process and increase the added value of cultural products that are good for all forms of intangible technology. In the field of Culture Technology, Music by analyzing the characteristics of the development of a variety of applications has been studied. Associated with EEG measures and the results of their research in response to musical stimuli are used to detect and study is getting attention. In this paper, the musical stimuli in EEG signals by amplifying the corresponding reaction to the averaging method, ERP (Event-Related Potentials) experiments based on the process of extracting sound methods for removing noise from the ICA algorithm to extract the tone and noise removal according to the results are applied to analyze the characteristics of EEG.

Biases in the Assessment of Left Ventricular Function by Compressed Sensing Cardiovascular Cine MRI

  • Yoon, Jong-Hyun;Kim, Pan-ki;Yang, Young-Joong;Park, Jinho;Choi, Byoung Wook;Ahn, Chang-Beom
    • Investigative Magnetic Resonance Imaging
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    • v.23 no.2
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    • pp.114-124
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    • 2019
  • Purpose: We investigate biases in the assessments of left ventricular function (LVF), by compressed sensing (CS)-cine magnetic resonance imaging (MRI). Materials and Methods: Cardiovascular cine images with short axis view, were obtained for 8 volunteers without CS. LVFs were assessed with subsampled data, with compression factors (CF) of 2, 3, 4, and 8. A semi-automatic segmentation program was used, for the assessment. The assessments by 3 CS methods (ITSC, FOCUSS, and view sharing (VS)), were compared to those without CS. Bland-Altman analysis and paired t-test were used, for comparison. In addition, real-time CS-cine imaging was also performed, with CF of 2, 3, 4, and 8 for the same volunteers. Assessments of LVF were similarly made, for CS data. A fixed compensation technique is suggested, to reduce the bias. Results: The assessment of LVF by CS-cine, includes bias and random noise. Bias appeared much larger than random noise. Median of end-diastolic volume (EDV) with CS-cine (ITSC or FOCUSS) appeared -1.4% to -7.1% smaller, compared to that of standard cine, depending on CF from (2 to 8). End-systolic volume (ESV) appeared +1.6% to +14.3% larger, stroke volume (SV), -2.4% to -16.4% smaller, and ejection fraction (EF), -1.1% to -9.2% smaller, with P < 0.05. Bias was reduced from -5.6% to -1.8% for EF, by compensation applied to real-time CS-cine (CF = 8). Conclusion: Loss of temporal resolution by adopting missing data from nearby cardiac frames, causes an underestimation for EDV, and an overestimation for ESV, resulting in underestimations for SV and EF. The bias is not random. Thus it should be removed or reduced for better diagnosis. A fixed compensation is suggested, to reduce bias in the assessment of LVF.

Comparative Analysis of Conductive Paste in Electroencephalography: Evaluation of Artifact and Satisfaction (뇌파검사에서 전도성 접착제의 비교분석: 인공산물과 만족도 평가)

  • Jae-Hwan SONG;Sung-Hee KIM;Dae-Hyun KIM
    • Korean Journal of Clinical Laboratory Science
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    • v.56 no.1
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    • pp.85-88
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    • 2024
  • Electroencephalography (EEG) is a test that diagnoses epilepsy and measures brain function. During EEG, the space between the electrode and the skin is filled with a conductive paste to reduce the impedance between the electrode and the scalp, which helps measure the EEG signals. This study compared the artifacts of the two representative conductive pastes (Ten20 and Elefix). The artifacts, noise, and satisfaction were surveyed after using the two conductive pastes. The two conductive pastes had similar artifacts and noise, but the survey results showed that the Elefix conductive paste had better satisfaction and adhesion. This result may be explained by the imprinting effect according to the experience of using the Elefix conductive paste first in the EEG class. Hence, further research is needed.

Evaluation of Image Noise and Radiation Dose Analysis In Brain CT Using ASIR(Adaptive Statistical Iterative Reconstruction) (ASIR를 이용한 두부 CT의 영상 잡음 평가 및 피폭선량 분석)

  • Jang, Hyon-Chol;Kim, Kyeong-Keun;Cho, Jae-Hwan;Seo, Jeong-Min;Lee, Haeng-Ki
    • Journal of the Korean Society of Radiology
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    • v.6 no.5
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    • pp.357-363
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    • 2012
  • The purpose of this study on head computed tomography scan corporate reorganization adaptive iteration algorithm using the statistical noise, and quality assessment, reduction of dose was evaluated. Head CT examinations do not apply ASIR group [A group], ASIR 50 applies a group [B group] were divided into examinations. B group of each 46.9 %, 48.2 %, 43.2 %, and 47.9 % the measured in the phantom research result of measurement of CT noise average were reduced more than A group in the central part (A) and peripheral unit (B, C, D). CT number was measured with the quantitive analytical method in the display-image quality evaluation and about noise was analyze. There was A group and difference which the image noise notes statistically between B. And A group was high so that the image noise could note than B group (31.87 HUs, 31.78 HUs, 26.6 HUs, 30.42 HU P<0.05). The score of the observer 1 of A group evaluated 73.17 on 74.2 at the result 80 half tone dot of evaluating by the qualitative evaluation method of the image by the bean curd clinical image evaluation table. And the score of the observer 1 of B group evaluated 71.77 on 72.47. There was no difference (P>0.05) noted statistically. And the inappropriate image was shown to the diagnosis. As to the exposure dose, by examination by applying ASIR 50 % there was no decline in quality of the image, 47.6 % could reduce the radiation dose. In conclusion, if ASIR is applied to the clinical part, it is considered with the dose written much more that examination is possible. And when examination, it is considered that it becomes the positive factor when the examiner determines.

Aequorin Based Functional Assessment of the Melanin Concentrating Hormone Receptor by Intracellular Calcium Mobilization

  • Lee, Sung-Hou
    • Biomolecules & Therapeutics
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    • v.18 no.2
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    • pp.152-158
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    • 2010
  • Melanin concentrating hormone is a neuropeptide highly expressed in the brain that regulates several physiological functions mediated by receptors in the G-protein coupled receptor family, especially plays an important role in the complex regulation of energy balance and body weight mediated by the melanin concentrating hormone receptor subtype 1 (MCH1). Compelling pharmacological evidence implicating MCH1 signaling in the regulation of food intake and energy expenditure has generated a great deal of interest by pharmaceutical companies as MCH1 antagonists may have potential therapeutic benefit in the treatment of obesity and metabolic syndrome. Although fluorescence-based calcium mobilization assay platform has been one of the most widely accepted tools for receptor research and drug discovery, fluorescence interference and shallow assay window limit their application in high throughput screening and have led to a growing interest in alternative, luminescence-based technologies. Herein, a luminescence-based functional assay system for the MCH1 receptor was developed and validated with the mitochondrial targeted aequorin. Aequorin based functional assay system for MCH1 presented excellent Z' factor (0.8983) and high signal-to-noise ratio (141.9). The nonpeptide MCH1 receptor antagonist, SNAP 7941 and GSK 803430, exhibited $IC_{50}$ values of 0.62 ${\pm}$ 0.11 and 12.29 ${\pm}$ 2.31 nM with excellent correlation coefficient. These results suggest that the aequorin based assay system for MCH1 is a strong alternative to the traditional GPCR related tools such as radioligand binding experiments and fluorescence functional determinations for the compound screening and receptor research.

The effect of model parameters on single dipole source tracing in EEG (모델 변수가 EEG의 Single Dipole Source 추정에 끼치는 영향에 관한 연구)

  • 박기범;박인호;김동우;배병훈;김수용;박찬영;김신태
    • Progress in Medical Physics
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    • v.5 no.1
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    • pp.41-53
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    • 1994
  • The accurate localization of electrical sources in the brain is one of the most important questions in EEG, especially in the analysis of evoked responses and of epileptiform spike activity. A detailed simulation study of single dipole source estimation based on EEG is given in this paper. The effects of dipole model parameters on single dipole source tracing in EEG are examined in some detail using the Monte Carlo simulation. The error of source localization is found to be greatly influenced by how the electrodes are distributed over the head and the number of them.

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A semispherical SQUID magnetometer system using high sensitivity double relaxation oscillation SQUIDs for magnetoencephalographic measurements

  • Lee, Yong-Ho;Hyukchan Kwon;Kim, Jin-Mok;Kim, Kwoong;Park, Yong-Ki
    • Progress in Superconductivity and Cryogenics
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    • v.5 no.1
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    • pp.21-26
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    • 2003
  • We designed and constructed a multichannel superconducting quantum interference device (SQUID) magnetometer system to measure magnetic fields from the human brain. We used a new type of SQUID, the double relaxation oscillation SQUID (DROS). With high flux-to-voltage transfers of the DROS, about 10 times larger than the dc SQUIDs, simple flux-locked loop circuits could be used for SQUID operation. Also the large modulation voltage of the DROS, typically being 100 $mutextrm{V}$, enabled stable flux-locked loop operation against the thermal offset voltage drift of the preamplifier. The magnetometers were fabricated using the Nb/AlOx/Nb junction technology. The SQUID system consists of 37 signal magnetometers, distributed on a semispherical surface, and 11 reference channels were installed to pickup background noises. External feedback was used to eliminate the magnetic coupling with the adjacent channels. The liquid helium dewar has a capacity of 29 L and boil-off rate of about 4 L/d with the total 48 channel insert. The magnetometer system has an average noise level of 3 fT/√Hz at 100 Hz, inside a shielded loon, and was applied to measure auditory-evoked fields.

Preliminary Study on the Effects of Monaural Beating Sound of Tires to Human Body (타이어의 모노럴 비팅음이 인체에 유발하는 영향에 관한 기초 연구)

  • Baek, Kwang-Hyun
    • The Journal of the Acoustical Society of Korea
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    • v.30 no.1
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    • pp.49-55
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    • 2011
  • The effects of monaural beating sound generated according to the number of tire pitch blocks to human body are measured from experiments, and the possibilities of similar positive effects of enhancing alpha waves in human brain are investigated. Due to the requirement of repeatability and measurement conditions, recorded sounds of the tire noise are used for the experiment in a quiet room and human responses are measured using HRV. Although the number of statistically meaningful results was small, it showed that positive human reactions are probably possible.

Classification of General Sound with Non-negativity Constraints (비음수 제약을 통한 일반 소리 분류)

  • 조용춘;최승진;방승양
    • Journal of KIISE:Software and Applications
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    • v.31 no.10
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    • pp.1412-1417
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    • 2004
  • Sparse coding or independent component analysis (ICA) which is a holistic representation, was successfully applied to elucidate early auditor${\gamma}$ processing and to the task of sound classification. In contrast, parts-based representation is an alternative way o) understanding object recognition in brain. In this thesis we employ the non-negative matrix factorization (NMF) which learns parts-based representation in the task of sound classification. Methods of feature extraction from the spectro-temporal sounds using the NMF in the absence or presence of noise, are explained. Experimental results show that NMF-based features improve the performance of sound classification over ICA-based features.

Electromagnetic Forces Measurement of Various Electric Appliances and Places (각종 전기기기 및 장소에서의 전자파 측정)

  • Kim, Deok-Won;Ryu, Chang-Yong;Kim, Su-Chan;Yoon, Hyung-Ro
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.05
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    • pp.179-182
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    • 1995
  • Although air, water, and noise pollutions have been widely recognized, electromagnetic forces(EMF) hazard has been rarely recognized as a pollution and very little studies has been done in this country. Thus, in this study electromagnetic forces radiated by various home appliances, once machines, and communication equipments were measured and so were several places radiating strong EMF such as subway stations and electric substations. Among the home appliances microwave oven senates lots of magnetic field and microwaves, and electric mattress does strong magnetic field. In video game room strong magnetic and considerable electric fields were measured. It was observed strong magnetic field inside of electric powered train and very strong magnetic and electric fields on some platforms. Hand-phone and car-phone radiate very hazardous level of microwaves to brain and that they rapidly come into wide use. In this study data base for various electric machines and places radiating strong EMFs were constructed and could be used for future epidemiological studies.

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