• Title/Summary/Keyword: Median Frequency

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Electroencephalographic Correlation Dimension Changes with Depth of Halothane

  • Lee, Maan-Gee;Park, Eun-Ju;Choi, Jung-Mee;Yoon, Moon-Han
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.5
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    • pp.491-499
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    • 1999
  • This study was designed to evaluate the efficacy of dynamic parameters, such as correlation dimension $D_2,$ by comparing spectral electroencephalographic (EEG) parameters. These parameters are used to estimate the depth of halothane anesthesia as defined by the presence of body movement in response to a tail clamp. Six rats were used and each of them was exposed to halothane sequentially at the concentrations of 0%, 0.5%, 1.0% and 1.5% for 30 min. A tail clamp was applied every five min and the movements were recorded at each concentration level. The spectral parameters and the dynamic parameters were derived from 20-sec and 10-sec segments, respectively, from the last 5-mins of EEG recording at each concentration level. Correlation coefficients between the parameters and the movements were calculated. Standardized values of three parameters, betaL power, median power frequency (MPF), and $D_2$ were derived by calculation based on the number of animals showing the movement in response to a tail clamp. The betaL power had the largest correlation coefficient to spontaneous movement and to the response to a tail clamp than any other band parameter. MPF had a better correlation with the movement than 90% spectral edge frequency. Among the dynamic parameters, $D_2$ on the parietal cortex had a better correlation with the movement. The level of deviation and variation of standardized $D_2,$ MPF, and betaL were significant (p<0.01). The order of deviation and variation was; betaL power > MPF > $D_2.$ The correlation dimension serves as a better index for the depth of halothane anesthesia defined in forms of a response to external stimulation.

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A Method to Suppress False Alarms of Sentinel-1 to Improve Ship Detection

  • Bae, Jeongju;Yang, Chan-Su
    • Korean Journal of Remote Sensing
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    • v.36 no.4
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    • pp.535-544
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    • 2020
  • In synthetic aperture radar (SAR) based ship detection application, false alarms frequently occur due to various noises caused by the radar imaging process. Among them, radio frequency interference (RFI) and azimuth smearing produce substantial false alarms; the latter also yields longer length estimation of ships than the true length. These two noises are prominent at cross-polarization and relatively weak at co-polarization. However, in general, the cross-polarization data are suitable for ship detection, because the radar backscatter from background sea surface is much less in comparison with the co-polarization backscatter, i.e., higher ship-sea image contrast. In order to improve the ship detection accuracy further, the RFI and azimuth smearing need to be mitigated. In the present letter, Sentinel-1 VV- and VH-polarization intensity data are used to show a novel technique of removing these noises. In this method, median image intensities of noises and background sea surface are calculated to yield arithmetic tendency. A band-math formula is then designed to replace the intensities of noise pixels in VH-polarization with adjusted VV-polarization intensity pixels that are less affected by the noises. To verify the proposed method, the adaptive threshold method (ATM) with a sliding window was used for ship detection, and the results showed that the 74.39% of RFI false alarms are removed and 92.27% false alarms of azimuth smearing are removed.

A Study of the Intraocular Pressure of Korean Youth (한국인 청년의 안압 측정)

  • Kim, Sang-Moon
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.2
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    • pp.91-97
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    • 2006
  • The intraocular pressure for Korean youth were measured by using tonometer (AT555-Reichert). The relative frequency distributions of intraocular pressures have been studied for samples of 1,027 persons(475 males, 552 females). The most commonly recorded IOP for both men and women was around 14.5mmHg and 17.5mmHg, respectively. They were in the range of 7 to 23mmHg(males) and 7 to 22mmHg(females). The median pressure(cumulative frequency=0.5%) is 13.0~16.5mmHg for males and 16.5~18.5mmHg for females, so the values for females are slightly higher than males. The mean pressure is 15.2mmHg for males and 15.8mmHg for females, respectively. The 98% of population was in the range of the normal IOP. There are long-term diurnal variation in mean intraocular pressure and the IOP was decreased as a function of time from morning to night. The measured IOP was affected by several factors: exercise made to decrease the IOP and tight collars, dark places and posture of decubitus position got to elevate the IOP.

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근육 피로도 분석시 사용되는 매개변수들간의 민감도 비교 연구

  • 정명철;김정룡
    • Proceedings of the ESK Conference
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    • 1997.10a
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    • pp.406-413
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    • 1997
  • 근전도(EMG:Electromyogram)를 사용하여 국부 근육 피로(Localized Muscle Fatigue)를 정량화으로 분석 하기 위해 널리 이용되고 있는 AR(Autoregressive)모델의 1차 계수, RMS(Root Mean Square), ZCR(Zero Crossing Rate), MPF(Mean Power Frequency), MF(Median Frequency)를 선택하여, 근육이 발휘하는 힘과 시간의 흐름에 따라 근육 피로의 정도를 민감하게 나타내는 매개변수를 규명하였다. 피실험자 10명의 좌우 척추세움근(Erector Spinae Muscle)을 대상으로 등장수축(Sustained Isometric Contraction)조건에서 허리의 신전(Extension)운동을 실시하였다. 이때 발휘해야 하는 힘의 수준은 15%, 30%, 45%, 60%, 75% MVC 로 정하였고 각 수준마다 20초 동안 근전도를 측정하 였다. 데이터 분석은 총20초 구간의 근전도를 0.5초 간격으로 나누어 매개변수들을 각각 구하고 분석을 실시하였다. 시간의 흐름에 대한 피로도 분석 결과, AR 모델의 1차 계수와 MPF가 유의한 차이를 보였으며, 낮은 수준의 %MVC에서는 AR 계수가, 높은 수준에서는 MPF가 민감한 반응 결과를 나타냈다. 그리고 근육이 발휘하는 힘의 정도를 분석하기 위해 주로 사용되고 있는 RMS 보다는 더 AR 계수가 모든 수준에서 뚜렷하게 차이를 보인 것이 확인되었다. 따라서 AR 모델의 1차 계수가 근육의 피로 정도와 힘의 수준을 다른 매개변수에 비해 더욱 민감하게 구별함이 입증되었다. 이러한 결과는 다른 분야에서도 근육 피로를 정량적으로 측정하는데 사용될 수 있을 것으로 생각되며, 개인적 변이도를 고려한 확률 기법을 사용한다면 보다 정확한 근전도 분석이 이루어질 것으로 기대된다.있음을 알 수 있었다. 사료된다.의 결과는 자전거 에르고노미터의 결과가 트레드밀의 결과에 87.60%정도 나타났다.음을 관찰하였다. 특히 vitamin C와 E의 병용투여는 상승적으로 적용하여 간세포손상을 더욱 억제시킴을 알 수 있었다.mance and on TFP(Total Factor Productivity) growth which is a pure measure of firm performance. To utilize the advantage of panel data, FEM(Fixed Effect Model) and REM(Random Effect Model) were used. The empirical result shows that the entropy index as a measurement of inter-business relatedness is not significant but technological relatedness index is significant. OLS estimates on pooled data were considerably different from FEM or REM estimates on panel data. By introducing interaction effect among the three variables for business portfolio properties, we obtained three findings. First, only VI (Vertical integration) has a significant positive correlation with ROS. Second, when using TFP growth as an dependent variable, both TR(Technological Relatedness) and f[ are signif

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The assessment of anesthetic depth by quantitative electroencephalography in intravenous anesthesia by intermittent bolus injection (간헐적 일시 정맥주사 마취에서 정량적 뇌파분석을 이용한 마취 심도의 평가)

  • Lee, Soo-Han;Bae, Chun-Sik;Noh, Gyu-Jeong;Bae, Kyun-Seop;Kim, Jin-Young;Chung, Byung-Hyun
    • Korean Journal of Veterinary Research
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    • v.45 no.1
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    • pp.131-137
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    • 2005
  • To assess anesthetic depth using quantitative electroencephalography (q-EEG), we recorded processed EEG (raw EEG) till 100 minutes in beagle dogs anesthetized for 60 minutes with tiletamine/zolazepam (n=5, TZ group), xylazine/ketamine (n=5, XK group) and propofol (n=5, PI group) by intermittent bolus injection. Raw EEG was converted into 95% spectral edge frequency (SEF) and median frequency (MF) through fast fourier transformation (FFT) method. 95% SEF value of TZ group was significantly higher (p<0.05) than the XK group from 10 minutes to 100 minutes. 95% SEF value of PI group was significantly higher (p<0.05) than the XK group from 10 minutes to 40 minutes, and significantly low (p<0.05) than XK group at 90 and 100 minutes. MF was significantly higher (p<0.05) in TZ group from 60 minutes to 100 minutes. Based on these results, using dissociative agent with ${\alpha}_2$-adrenergic agent is more potent in CNS depressed than using dissociative agent alone, and low doses of propofol has a disinhibitory effect on CNS.

A Study on the Attitude of Soy Food and Estimated Dietary Isoflavone Intake among Korean Adolescents (청소년의 대두식품에 대한 태도 및 추정된 이소플라본의 섭취수준에 관한 연구)

  • 이민준;김민정;민성희;윤선
    • Korean Journal of Community Nutrition
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    • v.9 no.5
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    • pp.606-614
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    • 2004
  • This study was conducted to investigate the attitude to various soy foods and to estimate dietary isoflavone intake among Korean adolescents. The survey was carried out by self-administered questionnaire with 800 middle and high school students residing in urban and rural areas and 714 questionnaires were collected: resulting in 89% response rate. The dietary isoflavone intake was estimated by food frequency questionnaire developed for rapid assessment of isoflavone intake. Soybean paste, soybean curd, soy milk, bean sprouts and dambuk were recognized as nutritious and healthy food in order. Dambuk got the lowest score in taste and flavor. Bean sprouts, soybean curd and soybean paste were recognized as familiar food in order. Stuffed rice in fried soybean curd got the highest score and Miso soup got the lowest in preference. More than 50% of the subjects consumed soybean paste stew/soup and soybean curd over twice per week and 12.3% of the subjects consumed soybean over once a day. The estimated daily intake of isoflavones ranged from 0 to 227 mg, and the mean daily isoflavone intake of the subjects was 28.1 mg (16.3 mg genistein and 12.0 mg daidzein) whereas the median value of isoflavone intake was 19.7 mg. There was statistically significant relationship among Kyung Gi Do, Chung cheung Do and Seoul residents in their intake of isoflavone. The highest monthly income group consumed isoflavone more than the other groups. These results suggest that Korean adolescent perceived the soybean dishes as high quality foods but they didn't take much because of difficulty to cook or less chance to eat. Nutrition education program is needed to enhance consuming soy foods for prevention of chronic diseases related to dietary isoflavone intake. More detailed information on easy cook method of soy food is also needed.

Implementation of Carpal Tunnel Syndrome Prevention System Using Arduino (Arduino를 활용한 손목 터널 증후군 예방 시스템 구현)

  • Hwang, Woo-Jin;Woo, Youn-Ho;Noh, Yun-Hong;Jeong, Do-Un
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.531-532
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    • 2016
  • Carpal tunnel syndrome, carpal tunnel becomes part of a narrower median nerve pain occurs pressed. How a stable wrist stretch for the prevention of carpal tunnel syndrome is required, it should life guides to fit the user is provided. In this research, users themselves recognize the risk of carpal tunnel syndrome, to be able to stretch, it implements the application. Application, based on the usage time set by the user, executes the alarm and lock. At this time, the user may utilize arduino and inertia sensor, it is possible to wrist stretch, to analyze usage patterns, it is possible to provide a medical information and life guides to suit the user. Data using Bluetooth 4.0 communication has been to meet the runaway. In order to evaluate the mounted system, targeting four subjects, the time and the touch frequency of usage of the 3-day smartphone measured, as a result of the questionnaire, it reduces the frequency of use of smartphones, a positive it was possible to prove the effect.

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The Study on Workload Reducing Effects of Multi-Elastic Insoles (다탄성 Insole의 Workload 감소 효과에 관한 연구)

  • Lee, Chang-Min;Lee, Kyun-Deuk;Oh, Yeon-Ju;Kim, Jin-Hoon
    • Journal of the Ergonomics Society of Korea
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    • v.26 no.2
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    • pp.157-165
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    • 2007
  • The Work-Related Musculoskeletal Disorders (WMSDs) can be occurred by various factors such as repetition, forceful exertions and awkward postures. Especially, occurrences of the WMSDs on the waist and lower limb are reported in workplaces, demanded standing postures for a long time, in service and manufacturing industry. The static and standing postures without movement for a long time increase work loads to the lower limb and the waist. Accordingly, anti-fatigue mat or anti-fatigue insole is used as a preventing device of the WMSDs. However anti-fatigue mats are limited in space and movement. In this study, multi-elastic insoles are designed and shown the effects of the workload reduction for a long time under the standing work. The foot pressures and EMG (Electromyography) are measured at 0 hour and after 2 hours by 6 health students in their twenties. The 6 prototype insoles are designed with three elastic (Low, Medium and High). These insoles are compared with no insole (insole type 7) as control group. The EMG measurement was conducted to waist (erector spinae muscle), thigh (vastus lateralis muscle) and calf (gastrocnemius muscle). The foot pressure is analyzed by mean pressure value and the EMG analysis is investigated through MF (Median Frequency), MPF (Mean Power Frequency) and ZCR (Zero Crossing Rate). The results of the foot pressure show that the multi-elastic insoles had smaller foot pressure value than that of no-insole. Moreover, Insole 2 and Insole 3 have the smallest increasing rate in foot pressure. The EMG results show that the multi-elastic insoles had smaller EMG shift value than that of no-insole in 2 hour, and then shift value shows the smallest value in Insole 2. Therefore, this study presents that the multi-elastic insoles have reducing effects of the work load for a long time standing work in both side of foot pressure and EMG.

Radar Target Segmentation via Histogram Chord Search Method (히스토그램 현 탐색방식에 의한 레이다 표적 분할 알고리즘)

  • Choi, Beyung-Gwan;Kim, WhAn-Woo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.6
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    • pp.195-202
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    • 2005
  • An adaptive segmentation algorithm is used to efficiently target decisions in local non-stationary images. Until now, several adaptive approaches have been proposed as a method of segmentation. However, they can't be directly used for radar target detection because a radar signal has different characteristics from general images. Generally, a histogram of radar signal shows that targets have a relatively small number of frequency functions compared to the background and distribution of background, which have several shapes as the environment changes. In this paper, we propose an adaptive segmentation algorithm using a histogram chord which is a right-down line from maximum pick of frequency function. The proposed method provides thresholds which are optimum for several radar environments because the used chord for threshold search is not significantly effected by interference conditions. Simulation results show that the proposed method is superior to the traditional algorithms, global threshold method and distribution median method, with respect to detection performance.

A Microbiological Study of Sterilized Materials on Dressing Carts (병원"드레싱"상중 일부물품의 오염도에 관한 조사연구)

  • 박정호;이영자;김태희
    • Journal of Korean Academy of Nursing
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    • v.3 no.2
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    • pp.45-51
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    • 1973
  • Bacterial cultures of the transfer forceps, 4"$\times$4"mesh gauze and polluted air of nursing units of general surgery, internal medicine, gynecology and pediatrics of S.N.U.H. were carried on for S consecutive days (from 17th to 21s1 August, 1972) to investigate the degree of contamination of such instruments which were used in dressing the patients. 1. The average hospitalized patients for each nursing unit were 24 persons. 2. The frequency of dressing, and using forceps and gauze in surgical nursing unit were 25,316 and 66 times respectively. Actually the forceps were used most frequently. There was no dressing in the nursing unit of internal median. 3. Most of dressing were carried on from 11 : 00 to 13 : 59 o′clock. 4. Averagely 121.5 persons passed through each nursing unit. 549 visitors dropped in the nursing unit of gynecology in maximum, and 219 visitors in the nursing of internal medicine in minimum. The visitors rushed in from 11 : 00 to 13 : 59 o′clock to he 142.5 persons for each nursing unit in average. 5. Colony counts after the bacterial cultures of the forceps and gauze disclosed 1098.44 and 704.51 per plate respectively. 6. The degree of contamination was parallel to the duration and frequency of dressings. 7. The degree of contamination of the instruments was severest in the nursing unit of internal medicine, and !east in the nursing unit of gynecology. On the matter of gauze, the contamination was most extreme in the pediatric nursing unit. 8. There was no significant daily differences in terms of contamination throughout the week. 9. It was disclosed that empty forceps jars were less contaminated than the jars with solution of any kind. 10. Bacterial cultures of the polluted air in corridor showed 73,88 colony counts per plate.

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