• Korean Journal of Biological Psychiatry
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• v.6 no.2
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• pp.176-188
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• 1999

Objective : The purpose of this study was to evaluate the effects of alcohol on neurocognitive function, psychomotor performance and subjective response in healthy Korean adults with different ALDH2 genotypes. Method : A total of 24 males, half with active $ALDH2^*1/2^*1$ and the other with inactive $ALDH2^*1/2^*2$, was selected through genotyping using restriction fragment length polymorphism. In a double-blind, placebo-controlled cross-over design, each subject consumed 0.5g/kg dose of alcohol, given as a mixture of 40% vodka and orange juice, and placebo(orange juice) on two separate occasions on an average of weekly intervals. The blood alcohol concentrations(BACs) were measured using a breath analyzer at baseline and at 30, 60 minutes after drinking. P300s were measured at baseline and at 30 minutes after alcohol and placebo intake. Vital signs and psychomotor performance[Critical Flicker Fusion Threshold(CFFT), Choice Reaction Time (CRT), Digit Symbol Substitution(DSS)] were measured at baseline and at 60 minutes after alcohol and placebo intake. Subjective responses were measured at the end of the study. The statistical analysis focused on whether there were any differences between groups with different ALDH2 genotypes. Results : The major results are as follows. 1) BACs in the inactive group were overall equivalent to those in the active group. Only in terms of time, BACs were significantly higher overall at 30 minutes than at 60 minutes after alcohol intake. 2) Pulse rates were significantly increased after alcohol intake compared with placebo, and the increase was greater in the inactive than in the active group. 3) P300 latencies in leads Fz(frontal), Cz(cental) and Pz(parietal) were significantly increased after alcohol intake compared to placebo, and the increase was greater in the inactive than in the active group. P300 amplitudes in leads Cz and Pz were significantly decreased overall after alcohol intake compared to placebo. 4) Compared with placebo, alcohol produced significant effect on the psychomotor performance : impairment in the inactive group, improvement in the active group. 5) Compared with placebo, alcohol significantly induced a negative or an intense effect on the subjective responses in the inactive group, but little negative and even a somewhat positive effect in the active group. Conclusions : These results suggest that ALDH isozyme variance might be an important factor to determine the effects of acute dose of alcohol on the various psychobehavioural functions and also to determine the alcohol use pattern and to predict the future development of alcohol overuse and/or abuse.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.17 no.1
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• pp.28-37
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• 2006

Purpose: Evaluation of vocal cord vibration is very important in cases of voice disorders. There are several equipments for examining the vocal fold vibration such as laryngeal stroboscope, ultra high-speed digital imaging system, and videokymograph. Among these, laryngeal stroboscope is the most popular equipment because of easy to examine the laryngeal pathology. However, current laryngo-stroboscopes are too bulky to move and relatively expensive. The purpose of this research is to develope a portable laryngeal stroboscope of equivalent performance with the current equipments. Methods and Materials: Recently developed high luminescent white LEDs(light emitting diodes) are placed at the head of the endoscope as light sources for the CCD image sensor which is also placed at the head with imaging lens. This arrangement eliminates the bulky light source like expensive halogen or xenon lamps as well as the optical light guiding cables. The LEDs are controlled to flash in phase with the voice frequency of the examinee. The CCD captures these strobo images and converts them into video signals for examinations. Results: There was no functional differences between preexisting stroboscope and the newly developed stroboscope of this study. LED light sources and microprocessor based control circuits of the stroboscope enabled the development of flicker-less, hand-held, portable and battery-operating stroboscope. Conclusion: The developed stroboscope is cost-effective, small-sized, easy to use and very easy desirable to bring and to use in any place.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2739-2746
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• 2011

This paper proposes the method for more effectively calculating X/R which is the ratio of equivalent reactance(X) and resistance(R) of the bulk power system and analyses the characteristic of X/R values by applying the proposed method to the real bulk power systems. X/R is used to determine the rating of the relay in the bulk power systems and its value has been accepted to be big enough to ignore the equivalent resistance of the bulk power systems. However, X/R is calculated as a big number when only the upper transformer and transmission line are considered. The correct approach to calculating X/R needs to consider all the parameters including generators, transformers, lines and loads. This paper calculates X/R of the bulk power systems using dynamic models which have been used to analyse the power system stability. The effectiveness of the proposed method is verified by applying it to the test system and X/R values of the real bulk power systems are analyzed. In addition, the dependence of X/R on the closeness of its calculating locations to the generator is verified by using the marginal loss factor which has been used in the electricity market.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.109-117
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• 2004

In this paper, a K-band local oscillator composed of a VCDRO(Voltage Controlled Dielectric Resonator Oscillator), GaAs MESFET, and Reflector type frequency doubler has been designed and fabricated. TO obtain a good phase noise performance of a VCDRO, a active device was selected with a low noise figure and a low flicker noise MESFET and a dielectric resonator was used for selecting stable and high oscillation frequency. Especially, to have a higher conversion gain than a conventional doubler as well as a good harmonic suppression performance with circuit size reduced a doubler structure was employed as the Reflector type composed of a reflector and a open stub of quarter wave length for rejecting the unwanted harmonics. The measured results of fabricated oscillator show that the output power was 5.8 dBm at center frequency 12.05 GHz and harmonic suppression -37.98 dBc, Phase noise -114 dBc at 100 KHz offset frequency, respectively, and measured results show of fabricated frequency doubler, the output power at 5.8 dBm of input power is 1.755 dBm conversion gain 1.482 dB, harmonic suppression -33.09 dBc, phase noise -98.23 dBc at 100 KHz offset frequency, respectively. This oscillator could be available to a local oscillator in K-band which used frequency doubler techniques.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.1
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• pp.40-48
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• 2009

Leading of the computer, IT technology has make great strides. As a information-industry-community was highly developed, user's needs to convenience about intelligence and humanization of interface is being increase today. Nowadays, researches with are related to BCI are progress put the application-technology development first in importance eliminating research about fountainhead technology with DB construction. These problems are due to a BCI-related research studies have not overcome the initial level, and not toward a systematic study. Brain wave are collected from subjects is a signal that the signal is appropriate and necessary in the experiment is difficult to distinguish. In addition, brain wave that it's not necessary to collect the experiment, serious eyes flicker, facial and body movements of an EMG and electrodes attached to the state, noise, vibration, etc. It is hard to collect accurate brain wave was caused by mixing disturbance wave in experiment on the environment. This movement, and the experiment of subject impact on the environment due to the mixing disturbance wave can cause that lowering cognitive and decline of efficiency when embodied BCI system. Therefore, in this paper, we propose an accurate and efficient brain-wave DB building system that more exactness and cognitive basis studies when embodied BCI system with brain-wave. For the minimize about brain wave DB with mixing disturbance, we propose a DB building method using an automatic control and prevent unnecessary action, put to use the subjects face tracking.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.241-247
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• 2016

As a domestic traffic control signal system, either the system with which a traffic signal turns into green at regular intervals or the system with which an amber or a red signal flickers on local roads without heavy traffic at midnight has been utilized. However, when the former system is used for roads with light traffic at midnight, delays and congestion can be incurred. Besides, in case of the latter signal system, the risk of vehicle crash is high. This study proposes a response type of flickering green signal system that rearranges signal system after analyzing beacon messages including sensor data. The proposed system, on a trunk road or a branch road at midnight, makes the signal keep flickering in green; When a vehicle enters the range of RSE, the transfer coverage, it transmits beacon messages regularly and Agent System analyzes the messages and alters the signal. It is a system by which vehicles move following the altered signal system, which will not only ensure smooth flow but also prevent vehicles from crashing on a road with light traffic. As a result of a simulation, traffic throughput and the average waiting time displayed 10 to 30 percent better improvement than existing signal systems, in terms of performance.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.2
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• pp.58-67
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• 1995

The paper describes the variation of magnetic fields caused by the operation of induction motors. The measuring system consists of the self-integrating magnetic field sensor, amplifier, and active integrator. From the calibration experiments, the frequency bandwidth of the magnetic field measuring system ranges from 20[Hz] to 300[kHz] and sensitivity is 0.234(mV/$\mu\textrm{T}$]. The magnetic fields generated under steady state and starting operations of duction motor are recorded by the proposed measuring system, and the fast Fourier transformation(FFT) of the measured data is performed to analyze the harmonic components. A single pulsed magnetic field is strongly caused by direct starting the induction motor, and its peak value is greater than 5 times as compared with the steady state value. The long transient duration and high intensity originates from the large inductance and dynamic characteristic of the induction motor, During the steady state operation of induction motor, subharmonics of magnetic field components, which depend on the pole number of induction motor, are observed. The lower order power-line harmonics can be inferred from the voltage flicker and current ripple which are derived from the torque fluctuation of induction motor. In the case of the induction motor drived by inverter, the harmonics of magnetic field are much more than those caused by direct starting method and are found generally to increase with decreasing the driving frequency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.491-499
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• 2019

Recently, there has been increasing demand for power quality in power supply devices. The IEC 61000-3-2 standard requires that the AC / DC power supply for lighting meet the specifications for the power factor (PF) and total waveform distortion (THD). In addition, advanced countries in Europe are regulating the ripple rate as 15 ~ 30% for the flicker phenomenon caused by the change in the amount of foot energy due to the change in current of the output terminal. Therefore, domestic standards and regulations are being updated. This study adopted the Flyback converter to satisfy the PFC standard, and has the circuit first and second insulation function. To reduce the low frequency ripple of the LED current, Flyback, Coupled Inductor, LC parallel resonance filter, LLC resonance filter, and Cuk were simulated by PSIM to mimic each LED driving circuit. A coupled LC resonant circuit with a coupled inductor on the primary side and LC resonance on the secondary side was also proposed for output side ripple reduction.

• Korean Journal of Biological Psychiatry
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• v.3 no.2
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• pp.222-239
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• 1996

The purpose of this study was to evaluate the effects of alcohol on the psychomotor performance and subjective assessment in healthy Korean adults with acetaldehyde dehydrogenase I(ALDH-I) isozyme variance. A total of 20 male subjects, half with active ALDH-I and the other half with inactive ALDH-I, were selected through both a self-reporting questionnaire examining alcohol sensitivity and the Higuchi's ethanol patch test detecting ALDH-I deficiency. In a doule-blind, placebo-controlled cross-over design, each subject consumed four doses of alcohol(0.25, 0.5, 0.75, 1.0g/kg) and placebo on five separate occasions at weekly intervals, Treatment order was fully balanced using a $5{\times}5$ Latin square, Psychomotor performance tests[coritical flicker fusion threshold(CFF) and choice reaction time(CRT)] and self-estimate questionnaires were conducted at baseline and at time points of 20, 40, 60, 90, 120, 150, 180 minutes after consuming the test drug for 20 minutes, Blood alcohol concentrations(BACs) using breath analyzer were measured at baseline and at time points of 10, 20, 30, 40, 50, 60, 75, 90, 105, 120, 150, 180 minutes after drinking, The BACs and the mean changes in the psychomotor performances and subjective assessments from pre-alcohol baseline, were compared between the two groups. The findings were summarized as follows : 1) BACs were tended to be higher in the inactive group than the active in all of the four alcohol doses. However significant group differences were only after the 0.5g/kg dose of alcohol. 2) The inactive group showed significant impairment in CFFT at most time points alter 0.75 and 1.0g/kg doses of alcohol. 3) In CRT, total reaction time(TRT) significantly prolonged in the inactive group than the active group at 20 minutes after 0.25 and 1.0g/kg doses of alcohol and at 40, 60, 90 minutes alter 0.75g/kg dose of alcohol. In the inactive group, recognition time component significantly increased at 20, 60, 90 minutes after 1.0g/kg dose of alcohol, while movement time component significantly increased at 40, 60 minutes after 0.75g/kg dose of alcohol. 4) Subjective evaluation of the effect of alcohol revealed that physical and mental conditions as well as a self-estimate of the effects of alcohol on performance were significantly worse in the inactive group than the active at some time points alter all of the lour alcohol doses, wihch were more pronounced after 0.75 and 1.0g/kg doses of alcohol. 5) Most of the group differences mentioned above, still remained statistically significant after BAC was entered as a covariate, These findings demonstrated that the alcohol sensitivity is higher in individuals with inactive ALDH-I than those with active ALDH-I both on the subjective assessments and the objective psychomotor performances. Furthermore, these results suggest thai the alcohol sensitivity may be determined by acetaldehyde concentration rather than BAC per se. In future studies, after more accurate genotyping for ALDH-I, the relationships between BAC, acetaldehyde concentration and alcohol sensitivities should be clearly defined.

• Korean Journal of Biological Psychiatry
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• v.3 no.2
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• pp.277-287
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• 1996

Objective : It has been proposed that cognition and related aspects of mental functioning are decreased in depression as well as in alcoholism. The objective of the study was to compare behavioral side effects of paroxetine and amitriptyline in depressed patients accompanied by alcoholism. The focused comparisons were drug effects concerning psychomotor performance, cognitive function, sleep and daytime sleepiness during the first 2 weeks of treatment. Methods : After an alcohol detoxification period(3 weeks) and a washout period(1 week), a total of 20 male inpatients with alcohol use disorder (DSM-IV), who also had a major depressive episode(DSM-IV), were treated double-blind with paroxetine 20mg/day(n=10) or amitriptyline 25mg/day(n=10) for 2 weeks. All patients were required to have a scare of at least 18 respectively on bath the Hamilton Rating Scale far Depression(HAM-D) and Beck Depression Inventory(BDI) at pre-drug baseline. Patients randomized to paroxetine received active medication in the morning and placebo in the evening whereas those randomized to amitriptyline received active medication in the evening and placebo in the morning. All patients performed the various tasks in a test battery at baseline and at days 3, 7 and 14. The test battery included : critical flicker fusion threshold for sensory information processing capacity : choice reaction time for gross psychomotor performance : tracking accuracy and latency of response to peripheral stimulus as a measure of line sensorimotor co-ordination and divided attention : digit symbol substitution as a measure of sustained attention and concentration. To rate perceived sleep and daytime sleepiness, 10cm line Visual analogue scales were employed at baseline and at days 3, 7 and 14. The subjective rating scales were adapted far this study from Leeds sleep Evaluation Questionnaire and Epworth Sleepiness Scale. In addition a comprehensive side effect assessment, using the UKU side effect rating scale, was carried out at baseline and at days 7 and 14. The efficacy of treatment was evaluated using HAM-D, BDI and clinical global impression far severity and improvement at days 7 and 14. Results : The pattern of results indicated thai paroxetine improved performance an mast of the lest variables and also improved sleep with no effect on daytime sleepiness aver the study period. In contrast, amitriptyline produced disruption of performance on same tests and improved sleep with increased daytime sleepiness in particular at day 3. On the UKU side effect rating scale, mare side effects were registered an amitriptyline. The therapeutic efficacy was observed in favor of paroxetine early in day 7. Conclusion : These results demonstrated thai paroxetine in much better than amitriptyline for the treatment of depressed patients accompained by alcoholism at least in terms of behavioral safety and tolerability, furthermore the results may assist in explaining the therapeutic outcome of paroxetine. For example, and earlier onset of antidepressant action of paroxetine may be caused by early improved cognitive function or by contributing to good compliance with treatment.