• Title/Summary/Keyword: wave control

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A COMPARATIVE STUDY UPON EVENT-RELATED POTENTIALS OF THE PATIENTS WITH ADHD AND NORMAL CHILDREN USING FOURIER TRANSFORMATION AND WAVELET ANALYSIS (푸리에 변환과 웨이브렛 분석을 통한 주의력결핍 ${\cdot}$ 과잉운동장애 아동과 정상 아동의 사건관련전위 비교 연구)

  • Park, Jin-Hyoung;Kim, Hee-Chan;Cho, Soo-Churl;Shin, Sung-Woong
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.12 no.1
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    • pp.25-50
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    • 2001
  • Using Fourier transformation and wavelet analysis, we compared the auditory event-related potentials of the patients with attention deficit-hyperactivity disorders(abbr. ADHD, 13 boys) and normal control children(8 boys). Amplitudes of the event-related potentials which were calculated via Fourier transformation were compared between the groups and between conditions(non-target versus target) in each group. To the non-target stimuli, the patients with ADHD showed significantly greater amplitudes across almost all of the electrode sites and frequencies. To the target stimuli, the incidents which ADHD patients showed much higher amplitudes than normal controls significantly decreased, while those of the reverse results increased significantly. These results were consistent with the comparison results about negative difference wave(abbr. Nd wave) using Fourier transformation. In summary, it was proved that non-target stimulus which should be ignored elicited more robust electrical response from the patients with ADHD than normal children, but the target stimulus which reguired active processing did much less electrical activity in the patients. For the patients, they showed much inhibited electrical response to the target stimuli in some electrodes and frequency ranges. Normal children were more strongly stimulated by the target stimuli in almost all electrodes and frequency ranges than the patients, but less in prefrontal leads and frontal leads. Wavelet analysis results proved that early responses(0-300msec) to the nontarget stimuli of the patients were significantly greater than the normal controls in prefrontal, anterior frontal, some parts of temporal, and occipital lobes and that late response(300-370msec) were significantly lesser than normal children in parietal and central electrodes. Target stimuli elicited significantly higher electrical activity in both group than non-target stimuli did. Prefrontal and frontal lobes showed stronger responses in the patients than normal children irrespective of stimulus condition, but parietal and temporal lobes did higher activities in normal children than the patients only to the target stimuli. In conclusion, the patients with ADHD showed much greater responses to the stimuli which should be ignored, but failed to activated the necessary processes to the target stimuli. Also, we found that the frequency-dimension analysis and wavelet analysis were useful for the signal processing such as event related potentials.

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Studies on the Grape Wines (part II) - On the browing methods and the aging (포도주에 관한 연구 (제2보) - 포도주 양조방법 및 숙성촉진에 대하여)

  • Kim, Chan Jo;Kim, Seong Yeul;Oh, Man Jin
    • Korean Journal of Agricultural Science
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    • v.2 no.2
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    • pp.451-462
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    • 1975
  • The qualities of the grape wines brewed with the varieties of Steuben, Muscat Bailey A, Merlot, Campbell Early and Alden were compared, and studied the mashing methods of the wine with a variety of Muscat Bailey A. and then investigated the aging effects of ultrasonic wave and the baking treatments on the new wines. The results obtained were as follows. 1. Extracts of the new wines brewed with the varieties of Steuben and Alden were 2.55 and 1.88 per cent respectively and the color densities of the wines with Merlot and Alden were 3.5 and 1.05 (optical density) respectively, and the other contents were not significantly different beween varieties. On the Otherhand, the results of sensory test showed that the order of favorite was the wines brewed with Steuben, Muscat Bailey A, Merlot, Campbell Early and Alden. 2. The effect of pasteurization ($55^{\circ}C$, 20 min.) on the inhibition of the growth of undesirable microorganism was appeared almost the same degree as the case of sulfiting (100 ppm), and the pasteurized must was more dense in color but slightly turbid than the case of sulfiting. 3. Glucose syrup was in adequate as a materials for supplemental sugar, and the quality of the new wine further fermented the free-run wine added the alcohol to be a constant alcohol content was almost the same as that of control. 4. Baking at $50^{\circ}C$. for 50 days to t he new wine from 0.45 to 0.65 per cent, and color density was also thicken from 2.8 to 3.17 (O. D). 5. Baking at $40^{\circ}C$. for 50days to the new wine brewed with Muscat Bailey A, increased the ester content of the wine from 0.37 to 0.65 per cent and color density was-also thicken from 3. to 4.2 (O.D). 6. Ultrasonic wave (150 watt, 20Kc) treatment for 10 hours to the new wine brewed with Muscat Bailey A, increased the ester content of the wine from 0.37 to 0.47 per cent.

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Angiotensinogen gene M235T polymorphism as a predictor of cardiovascular risk in hypertensive adolescents (고혈압 청소년의 심혈관계 위험요소로서 Angiotensinogen M235T 유전자 다형)

  • Gil, Joo Hyun;Lee, Jung Ah;Park, Eun Young;Hong, Young Mi
    • Clinical and Experimental Pediatrics
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    • v.52 no.1
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    • pp.36-43
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    • 2009
  • urpose : The renin-angiotensin system (RAS) has been demonstrated to play a major role in regulating blood pressure. Therefore, components of the RAS are likely candidate genes that may predispose an individual to essential hypertension and cardiovascular complications. Among them, the M235T polymorphism of the angiotensinogen gene has been speculated to be associated with elevated circulating angiotensinogen concentrations and essential hypertension. This study aimed to analyze the angiotensinogen M235T polymorphism in hypertensive adolescents and investigate its relationship with cardiovascular risks. Methods : Forty Korean hypertensive adolescents (aged 16-17, systolic $BP{\geq}140 mmHg$ and/or diastolic $BP{\geq}90 mmHg$) and fifty seven normal adolescents were included. Obesity index (OI), body mass index (BMI) were calculated. BP was measured by oscillometric methods in resting state. Polymerase chain reaction (PCR) technique was performed on DNA from the hypertensives subjects to analyze the M235T polymorphism. Serum homocysteine, insulin, renin, aldosterone and angiotensin converting enzyme (ACE) were tested according to each genotype. The carotid intima-media thickness (IMT) and carotid artery diameter, Pulse wave velocity (PWV) and ankle-brachial index (ABI) were measured according to each genotype. Results : Genotype frequencies of T/T, M/T and M/M were 62.5%, 35.0%, 2.5%, respectively in hypertensive adolescents. The results were not significantly different compared to control group. Serum insulin, renin levels, BMI and OI were significantly higher in thoses with the M/M genotype as compared to those with the T/T of M/T genotype. Conclusion : This study showed that the M235T polymorphism was not associated with essential hypertension or any cardiovascular risks. Further clinical research is required to ascertain the relationship between this polymorphism and cardiovascular complications in Korean hypertensive adolescents.

Relatively Decreased Level of Subjective Daytime Sleepiness and Its Associated Factors in Patients with Primary Insomnia (일차성 불면증 환자에서의 주간 졸림증과 연관된 수면변인에 대한 연구)

  • Lee, Yu-Jin;Lee, Jin-Sung;Sohn, Chang-Ho;Lee, Eun-Hye;Moon, Pil-Sung;Jeong, Do-Un
    • Sleep Medicine and Psychophysiology
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    • v.12 no.2
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    • pp.117-121
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    • 2005
  • Objectives: The purpose of this study was to assess the difference of subjective daytime sleepiness level between primary insomnia patients and healthy control subjects. We also investigated the relationship between subjective daytime sleepiness level and variables of nocturnal polysomnograghic sleep architecture of insomnia patients. Method: Total subjects were 87 patients with primary insomnia diagnosed with polysomnography and 88 normal controls. The daytime sleepiness level in each group was measured by Korean version of Epworth Sleepiness Scale (ESS). The correlations of ESS score and nocturnal polysomnographic variables were calculated in the patient group. Results: Patients with insomnia had the lower ESS scores than the control group. In patients group, the ESS score showed significant negative correlations with total sleep time, sleep efficiency%, and stage 2 sleep time%. The ESS score also showed significant positive correlations with number of awakenings, number of awakenings more than 2 minutes, and wake after sleep onset time. Conclusions: Insomnia patients showed lower level of subjective daytime sleepiness that may indicate their higher alertness comparing to control subjects. Daytime sleepiness of patients with insomnia was associated with polysomnographic variables including total sleep time, sleep efficiency%, stage 2 sleep time% and disrupted continuity of nocturnal sleep.

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A STUDY ON WEAR RESISTANCE OF FLOWABLE COMPOSITE RESINS (유동성 복합레진의 마모저항성에 관한 연구)

  • Yun, Yeon-Hee;Kim, Jung-Wook;Lee, Sang-Hoon;Hahn, Se-Hyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.29 no.2
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    • pp.217-225
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    • 2002
  • When we use the flowable resin on the primary molars for quick handling, one of the most important property is the wear resistance. This study was performed to compare the wear resistance characteristics of four flowable composite resins [Arabesk flow (group 1), Tetric flow (group 2), Aeliteflow (group 3), Filtek flow (group 4)] to that of one control composite resin [Z100 (group 5)]. Specimen discs(n=10), 10mm wide and 2mm thick, were stored in distilled water at $37^{\circ}C$ for 7 days prior to testing. The specimens were subjected to 50,000 strokes at 2 Hz on the MTS system. During the test, the following parameters were maintained: the lateral excursion at 0.4mm, occlusal force at 2-100N with a force profile in the form of a half sine wave. The measurements of volume loss, depth of wear, and Vicker's hardness number of composite resins, and SEM observations of the polished and abraded surfaces were established. One-way ANOVA and Scheffe's multiple comparison test were employed to detect statistically significant differences among the flowable composite resin groups and the control composite group at P<.05. The following results were obtained: 1. Group 3 showed the least volume loss, while group 4 showed the greatest. The mean volume loss increased in the following order: group 3

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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

Feasibility Study for the Cleaning of Well Screens using High-voltage Pulsed Discharge (고전압 펄스 방전을 이용한 지하수 관정 스크린 공막힘 재생법 연구)

  • Chung, Kyoung-Jae;Lee, Seok-Geun;Dang, Jeong-Jeung;Choi, Gil-Hwan;Hwang, Y.S.;Kim, Chul-Young;Park, Young-Jun
    • The Journal of Engineering Geology
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    • v.23 no.1
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    • pp.29-36
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    • 2013
  • The application of appropriate rehabilitation methods can improve the efficiency of clogged wells and extend their life. In this paper, we study the feasibility of well cleaning using high-voltage pulsed discharge, in which electrical energy is used to produce impulsive pressure in water, in contrast to conventional methods that employ chemical or pneumatic energy sources. This technique utilizes the compressive shock wave generated by the expansive force of hot, dense plasma that is produced during a pulsed discharge in the gap between electrodes immersed in water. Compared with conventional techniques, this method is simple, and easy to handle and control. Using a capacitive pulsed power system with an electrical energy of 200 J, an impulsive pressure of 10.7 MPa is achieved at the position 6 cm away from the discharge gap. The amplitude of the impulsive pressure was easily controlled by adjusting the charging voltage of the capacitor and was almost linearly proportional to peak discharge current. The technique achieved good results in cleaning feasibility tests with mock-up specimens similar to clogged well screens.

Multi-target Data Association Filter Based on Order Statistics for Millimeter-wave Automotive Radar (밀리미터파 대역 차량용 레이더를 위한 순서통계 기법을 이용한 다중표적의 데이터 연관 필터)

  • Lee, Moon-Sik;Kim, Yong-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.37 no.5
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    • pp.94-104
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    • 2000
  • The accuracy and reliability of the target tracking is very critical issue in the design of automotive collision warning radar A significant problem in multi-target tracking (MTT) is the target-to-measurement data association If an incorrect measurement is associated with a target, the target could diverge the track and be prematurely terminated or cause other targets to also diverge the track. Most methods for target-to-measurement data association tend to coalesce neighboring targets Therefore, many algorithms have been developed to solve this data association problem. In this paper, a new multi-target data association method based on order statistics is described The new approaches. called the order statistics probabilistic data association (OSPDA) and the order statistics joint probabilistic data association (OSJPDA), are formulated using the association probabilities of the probabilistic data association (PDA) and the joint probabilistic data association (JPDA) filters, respectively Using the decision logic. an optimal or near optimal target-to-measurement data association is made A computer simulation of the proposed method in a heavy cluttered condition is given, including a comparison With the nearest-neighbor CNN). the PDA, and the JPDA filters, Simulation results show that the performances of the OSPDA filter and the OSJPDA filter are superior to those of the PDA filter and the JPDA filter in terms of tracking accuracy about 18% and 19%, respectively In addition, the proposed method is implemented using a developed digital signal processing (DSP) board which can be interfaced with the engine control unit (ECU) of car engine and with the d?xer through the controller area network (CAN)

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The effect of MTAD on the apical leakage of obturated root canals: an electrochemical study (MTAD의 치근단 누출에 미치는 영향에 대한 전기화학적 연구)

  • Park, Dong-Sung
    • Restorative Dentistry and Endodontics
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    • v.31 no.2
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    • pp.119-124
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    • 2006
  • The purpose of this study was to evaluate the effect of newly developed endodontic root canal cleanser (MTAD) on the apical leakage of obturated root canal using an electrochemical method. Canals of 60 extracted single-rooted human teeth were prepared by using a crown-down technique with rotary nickel-titanium files. In Group 1 (positive control group) and 2 (negative centre) group), 5.25% NaOCl was used as a canal irrigant and no canal wall treatment was done. In group 3 only 5.25% NaOCl were used as canal irrigant, canal wall treatment and final rinse. In group 4, specimens were irrigated with 5.25% NaOCl, treated with 5 ml of 17% EDTA for 5 minutes and final rinsed with 5.25% NaOCl Specimens of group 5 were irrigated with 1 3% NaOCl and treated with 5 ml of MTAD for 5 minutes. All root canals are dried with paper points and obtuated with gutta-percha and AH plus as a sealer using a continuous wave of condensation technique except in the group 1. The electrical resistance between the standard and experimental electrodes in canals was measured over a period of 10 days. Rising of apical leakage with time was observed for all the groups. Group 4 and 5 showed lower apical leakage than group 3 but differences between the group 3, 4 and 5 were no statistical significance at any measurement time.

A Study on the Reflection of Rabbit Nervous Tissue After Electromagnetic Irradiation and the Effect of Nimodipine Injection (전자파에 노출된 토끼의 뇌신경조직의 반응과 Nimodipine 투여효과에 관한 연구)

  • 이근호;김영태
    • Journal of Biomedical Engineering Research
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    • v.19 no.1
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    • pp.81-90
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    • 1998
  • Electromagnetic waves may induce various effects on nervous tissues either by thermal or non-thermal mechanisms. This paper intoduces a method to evalute the non-thermal effect to central nervous system by measuring the EEGs of the rabbits treated by nimodipine before exposed to weak microwave field. 20 rabbits were divided into 2 groups and their EEGs were measured after their head section were exposed to 2,450 MHz microwave with the power density of 10 dBm and 20 dBm respectively for 10 minutes and compared with those of the 3rd group of 10 rabbits which were not exposed. The 4th group of 10 rabbits were intravenously given with nimodipine before exposed to 20 dBm field to determine whether this drug would reverse the EEGs changes induced by weak microwave irradiation. As field poser exceeded 20 dBm although no significant physiological changes were observed, total induced EEGs power was remarkably decreased suggesting the presence of CNS activation. Using Fourier analysis on the EEGs signal it was found that remarkable decrease in delta band and increase in the alpha and beta bands in a significant manner(P<0.05) compared to control group. The changes were, however, not reversed by nimodipine-treatment. The effects may be pure thermal in nature because no significant change has been observed in nimodipine treated rabbits.

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