• Annals of Clinical Neurophysiology
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• v.19 no.2
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• pp.113-117
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• 2017

The performance of electroencephalogram (EEG) recordings is affected by electrode type, electronic parameters such as filtering, amplification, signal conversion, data storage; and environmental conditions. However, no single method has been identified for optimal EEG recording quality in all situations. Therefore, we aimed to provide general principles for EEG electrode selection as well as electronic noise reduction, and to present comprehensive information regarding the acquisition of satisfactory EEG signals. The standards provided in this document may be regarded as Korean guidelines for the clinical recording of EEG data. The equipment, types and nomenclature of electrodes, and the details for EEG recording are discussed.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.515-520
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• 2012

In brain computer interface (BCI) system, the most important part is classification of human thoughts in order to translate into commands. The more accuracy result in classification the system gets, the more effective BCI system is. To increase the quality of BCI system, we proposed to reduce noise and artifact from the recording data to analyzing data. We used auditory stimuli instead of visual ones to eliminate the eye movement, unwanted visual activation, gaze control. We applied independent component analysis (ICA) algorithm to purify the sources which constructed the raw signals. One of the most famous spatial filter in BCI context is common spatial patterns (CSP), which maximize one class while minimize the other by using covariance matrix. ICA and CSP also do the filter job, as a raw filter and refinement, which increase the classification result of linear discriminant analysis (LDA).

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.193-194
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• 1998

This paper describes a multi-functional EEG (electroencephalogram) software. The software manages the patient's EEG data systematically and analyzes the signal and display the parameters on a PC monitor in real-time. Since the software provides various parameters simultaneously, user can observe patients multilaterally. Reference patterns of CSA and DSA can be captured and displayed on top of the monitor. And user can mark events of surgical operation or patient's conditions, so it is possible to jump to the points of events directly, when reviewing the recorded file afterwards. Many convenient functions are equipped and these are operated by mouse clicks.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.294-299
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• 2017

The aim of this study was to detect the status of epilepticus and seizure based on the initial patterns observed in the first 30 minutes of continuous electroencephalogram (cEEG) monitoring. An cEEG was recorded digitally using electrodes applied according to the International 10~20 System. The EEG data were reviewed from January 2014 to December 2015. The baselines of the EEG patterns were characterized by lateralized periodic discharges, generalized periodic discharges, burst suppression, focal epileptiform, asymmetric background, generalized slowing, and generalized periodic discharges with a triphagic wave. The etiology was classified into five categories. The subjects of this study were 128 patients (age: $56.9{\pm}17.5years$, male:female, 74:54). The mean cEEG monitoring duration was $5.5{\pm}5.1$ (min:max, 1:33) days. The EEG pattern categories included lateralized periodic discharges (N=7), generalized periodic discharges (N=10), burst suppression (N=6), focal epileptiform (N=19), asymmetric background (N=24), generalized slowing (N=51), and generalized periodic discharges with a triphagic wave (N=11). The etiological classifications of the patients with status epilepticus were remote symptomatic (N=4), remote symptomatic with acute precipitant (N=9), acute symptomatic (N=6), progressive encephalopathy (N=2), and febrile seizure (N=1). cEEG monitoring was found to be useful for the diagnosis of non-convulsive epileptic seizures or status epilepticus. The seizure was confirmed by the EEG pattern.

• Journal of Life Science
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• v.19 no.12
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• pp.1829-1835
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• 2009

Hyperventilation (HV) is routinely induced in order to activate brain waves during an electroencephalogram (EEG). The aim of this study was to examine the effects of HV conditions on EEG and suggested basic data for the standardized procedure. Three degrees of HV were induced for 5 minutes with a ventilation volume of 160 ml/min (control group), 240 ml/min, and 300 ml/min in rats. Powers of delta, theta, alpha, and beta waves were examined by a quantitative EEG. The results showed that there was no significant difference in the powers of all EEG waves between the control and 240 ml/min groups. However, a notable change in EEG powers during HV induced by a ventilation volume of 300 ml/min was observed in the frontal cerebral region as follows: power of the delta was increased by 12.8% (p<0.01), powers of the theta, alpha and beta were decreased by 41.3% (p<0.01), 48.6% (p<0.05), and 41.9% (p<0.05), respectively. Therefore, it is concluded that an increase of about 90% of the normal ventilation volume might be adequate for the hyperventilation, and a useful parameter for evaluation of the qualified hyperventilation might be an alteration of the frontal EEG powers.

• Journal of Ginseng Research
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• v.32 no.3
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• pp.220-225
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• 2008

The present investigation was performed to evaluate the homeostatic regulation of sleep architecture by the ethanol extract of Korea red ginseng (KRG), since the available data were often controversial. In addition, it was also interested in whether the sleep-wake stages were differently affected by low and high doses of KRG. Each adult Wistar male rat was implanted with a transmitter for recording EEG and activity via telemetry. After one week of surgery, polygraphic signs of undisturbed sleep-wake activities were recorded for 12 h (between 9:00 am and 9:00 pm) after KRG administration. KRG (10 and 100 mg/kg) increased non-rapid eye movement (NREM) sleep as well as total sleep. The total percentages of wakefulness were decreased comparably. KRG (10 mg/kg) decreased the power density of the ${\delta}-wave$ (0.75-4.5 Hz) and increased ${\alpha}-wave$ (8.0-13.0 Hz) in the NREM and rapid eye movement (REM) sleep. KRG also decreased ${\delta}-wave$ power density in wake time. However, KRG (100 mg/kg) increased ${\delta}-wave$ and decreased ${\theta}-wave$ (5.0-9.0 Hz) power density in wake time, while showed little effect on the power density in NREM and REM sleep. In conclusion, low and high doses of KRG increase spontaneous sleep and NREM sleep and differently regulate the EEG spectra in REM and NREM sleep.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.403-410
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• 2012

The current inquiry was conducted to assess the change in sleep architecture after long periods of administration to determine whether ginseng can be used in the therapy of sleeplessness. Following post-surgical recovery, red ginseng extract (RGE, 200 mg/kg) was orally administrated to rats for 9 d. Data were gathered on the 1st, 5th, and 9th day, and an electroencephalogram was recorded 24 h after RGE administration. Polygraphic signs of unobstructed sleep-wake activities were simultaneously recorded with sleep-wake recording electrodes from 11:00 a.m. to 5:00 p.m. for 6 h. Rodents were generally tamed to freely moving polygraphic recording conditions. Although the 1st and 5th day of RGE treatment showed no effect on power densities in nonrapid eye movement (NREM) and rapid eye movement (REM) sleep, the 9th day of RGE administration showed augmented ${\alpha}$-wave (8.0 to 13.0 Hz) power densities in NREM and REM sleep. RGE increased total sleep and NREM sleep. The total percentage of wakefulness was only decreased on the 9th day, and the number of sleep-wake cycles was reduced after the repeated administration of RGE. Thus, the repeated administration of RGE increased NREM sleep in rats. The ${\alpha}$-wave activities in the cortical electroencephalograms were increased in sleep architecture by RGE. Moreover, the levels of both ${\alpha}$- and ${\beta}$-subunits of the ${\gamma}$-aminobutyric acid $(GABA)_A$ receptor were reduced in the hypothalamus of the RGE-treated groups. The level of glutamic acid decarboxylase was over-expressed in the hypothalamus. These results demonstrate that RGE increases NREM sleep via $GABA_A$ergic systems.

• Archives of Craniofacial Surgery
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• v.23 no.2
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• pp.59-63
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• 2022

Background: Deformational plagiocephaly is usually managed conservatively, as it tends to improve over time and with the use of conservative measures. However, before the year 2017 we operated on patients with severe plagiocephaly and neurological symptoms at the Helsinki Cleft Palate and Craniofacial Center. Methods: Of the 20 infants with severe deformational plagiocephaly and neurological symptoms referred to us between 2014 and 2016, 10 underwent cranioplasty open reshaping of the posterior cranial vault. The parents of the last 10 patients were given information on the natural history of the condition and the patients were followed up with an outpatient protocol. The aim of this study was to gain information on the brain electrophysiology and recovery of patients after total cranial vault reconstruction by measuring the electroencephalogram (EEG) somatosensory evoked potentials (SEP; median nerve). Results: Of the 10 participants in the operation arm, six had abnormal SEP at least on the affected cerebral hemisphere and all SEPs were recorded as normal when controlled postoperatively. In the follow-up arm, eight out of 10 participants had abnormal SEP at the age of approximately 24 months, and all had normalized SEPs at control visits. Conclusion: Our data suggest that cranioplasty open reshaping of the posterior cranial vault did not affect abnormal SEP-EEG recordings. We have abandoned the operations in deformational plagiocephaly patients due to findings suggesting that expanding cranioplasty is not beneficial for brain function in this patient group.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.155-164
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• 2022

Considerable interest has been directed toward utilizing virtual environment-based simulations for teacher education which provide authentic experience of classroom environment and repetitive training. Emotional Interaction should be considered for more advanced simulation learning performance. Since emotion is important factors in creative thinking, inspiration, concentration, and learning motivation, identifying learners' emotional interactions and applying these results to teaching simulation is essential activities. In this context, this study aims to identify the objective data for the empathetic response through the movement of the learner's EEG (Electroencephalogram) and eye-tracking, and to provide clues for designing emotional teaching simulation. The results of this study indicated that intended empathetic response was provided and in terms of valence (positive and negative) states and situational interest played an important role in determining areas of interest. The results of this study are expected to provide guidelines for the design of emotional interactions in simulations for teacher education as follow; (a) the development of avatars capable of expressing sophisticated emotions and (b) the development of scenarios suitable for situations that cause emotional reactions.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.237-242
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• 2020

Construction noise is among the most critical stressors that adversely affect the quality of life of the people residing near construction sites. Many countries strictly regulate construction noise based on sound pressure levels, as well as timeslots and type of construction equipment. However, individuals react differently to noise, and their tolerance to noise levels varies, which should be considered when regulating construction noise. Although studies have attempted to analyze individuals' stress responses to construction noise, the lack of quantitative methods to measure stress has limited our understanding of individuals' stress responses to noise. Therefore, the authors proposed a quantitative stress measurement framework with a wearable electroencephalogram (EEG) sensor to decipher human brain wave patterns caused by diverse construction stressors (e.g., worksite hazards). This present study extends this framework to investigate the feasibility of using the wearable EEG sensor to measure individuals' emotional stress responses to construction noise in a laboratory setting. EEG data were collected from three subjects exposed to different construction noises (e.g., tonal vs. impulsive noises, different sound pressure levels) recorded at real construction sites. Simultaneously, the subjects' perceived stress levels against these noises were measured. The results indicate that the wearable EEG sensor can help understand diverse individuals' stress responses to nearby construction noises. This research provides a more quantitative means for measuring the impact of the noise generated at a construction site on neighboring communities, which can help frame more reasonable construction noise regulations that consider various types of residents in urban areas.