• Title/Summary/Keyword: Reference Frequency

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Wheelchair-based New Millennium Health Gymnastics: Muscle Activity and Upper Limbs Coordination by Elbow Exercise Velocity (휠체어 새천년 건강체조의 팔꿈치 운동속도에 따른 상지협응과 근활성도 변화)

  • Lee, Kang-Jin;Kim, Tack-Hoon
    • Journal of the Korean Society of Physical Medicine
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    • v.9 no.2
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    • pp.161-170
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    • 2014
  • PURPOSE: This study concerns the wheelchair-based rehabilitation of elderly people, investigating muscle activity and coordination of upper limbs during wheelchair-based new millennium health gymnastics with varying elbow exercise velocity. METHODS: Twelve elderly people participated in new millennium gymnastics twice per week during 12-weeks. The group was separated into 0.4, 1.0, and 1.6 Hz groups (controlled by the metronome speed). Range of motion was measured by electrogoniometer, electromyography signals used root mean square values. The data application was normalized using reference voluntary contraction (%RVC). Upper limb (wrist and elbow joint) data gathered while standing up after the "falling on hips" was investigated in terms of coordination of angle-angle plots. One-way ANOVA, paired t-test and Scheffe's post hoc comparisons, were used for statistical analyses. RESULTS: There were results taken before and after the experiments. The results demonstrated a significant improvement in the triceps brachii and flexor carpi radialis of the 0.4 Hz group (p<.05). There was significant difference in the triceps brachi of the 1 Hz group. No significant differences were found in all muscles of the 1.6 Hz group. Muscle co-activation indexes of the 0.4 Hz group were larger than the others. The 0.4 Hz graph was turning point synchronized clockwise. The 1 Hz graph was out of phase with the negative slope. The 1.6 Hz graph was turning point synchronized counterclockwise, and uncontrolled factor phase was offset on angle-angle plots. CONCLUSION: It is found that improvement of muscle activity and upper limbs coordination of elderly people using wheelchair-based new millennium gymnastics is optimal with elbow exercise velocity with a frequency of 0.4 Hz.

A Study on the Establishment of Brassiere Sizing System for Adult Women (성인(成人) 여성(女性)의 브래지어 치수규격설정(置數規格設定)에 관(關)한 연구(硏究))

  • Park, Eun-Mi;Sohn, Hee-Soon
    • Journal of Fashion Business
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    • v.4 no.1
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    • pp.45-58
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    • 2000
  • The purpose of this study is to provide for the basic data useful to the development of a quality bassiere featuring a good wearing feeling, to investigate the characteristics of breast shapes by age and suggest a brassiere sizing system for woman. For this purpose, the subjects of anthropometry were 220 women aged between 20 and 59. The anthropometric measurements were analyzed by various statistical methods mean, standard deviation, F-test, Duncan-test, Factor analysis, frequency. The results of this study can be summarized as follows; 1. According to the increase of age, the items of height were decreased and items of width, depth, circumference and length were increased, being obeser and breast point were drooped. So volume and bottom area of breast of 40 50's women were larger than 20 30's women and breast point width of 40 50's women was being wider by increase of the interior of breast. 2. From analyzing the effect of brassiere wearing, it was found that brassiere reformed the breast shape with the breast volume transferred from exterior part to interior part and the bottom area of breast diminished, so brassiere can have the breast location of adult woman up and the breast point width being centered 3. It was found that there was no direct linear relationships between under bust girth and cup size from analysis of breast measurements. Therefore those 2 factors(under bust girth and cup size) was brought into basic item of brassiere sizing system. From the dual distribution table whose intervals had been decided by KS K-0070(1999), it was picked out 12 sizes which had more than 4% of appearance for suggesting brassiere size chart. The sizing system covers 76.36% of all subjects and supply reference measurements relevant to brassiere manufacturing.

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Design of Bluetooth Receiver Front-end using High Gain Low Noise Amplifier and Microstrip Bandpass Filter (마이크로스트립 대역통과 여파기와 고이득 저잡음 증폭기를 이용한 블루투스 리시버 전반부 설계)

  • 손주호;최성열;윤창훈
    • Journal of Korea Multimedia Society
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    • v.6 no.2
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    • pp.352-359
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    • 2003
  • In this paper, we designed the bluetooth receiver using the microstrip bandpass filter and the high gain low noise amplifier with the 0.2$\mu\textrm{m}$ CMOS technology. A cascode inverter is adopted to implement the low noise amplifier and is one stage amplifier with a voltage reference and without the choke inductor. The designed 2.4GHz LNA was achieved a power gain of 18dB, a noise figure of 2.8dB, and the power consumption of 255mW at 2.5V power supply. Also, the microstrip receiver bandpass filter was designed that the center frequency was 2.45GHz, the bandwidth was 4% and the insert attenuation was -1.9dB. When the microstrip bandpass filter and LNA was simulated together the power gain was 16.3dB.

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Maternal and lifestyle effect on bone mineral density in Korean children and adolescents aged 8-19 (어머니의 골밀도와 생활습관이 소아청소년의 골밀도에 미치는 영향)

  • Lee, Byung-Kook;Lee, Yong Hyun;Lee, Hye Lim;Park, Sunmin
    • Journal of Nutrition and Health
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    • v.46 no.2
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    • pp.147-155
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    • 2013
  • Higher bone mineral density (BMD) at a young age, calcium intake, and exercise are important for prevention of osteoporosis later in life. We examined familial effects of BMD between mothers and children and adolescents aged 8-19 in Cheonan, Korea and the relationships between BMD and lifestyle parameters, including: food and nutrient intake and exercise. For daughters and sons, significant differences in BMD were observed at the three bone sites (total femur, femur neck, and lumbar spine) according to age, gender, body mass index, exercise, and milk consumption, compared to the reference value for each classification category. Mean differences in children's BMD were observed according to maternal BMD. Energy and calcium intake were lower in both children and mothers in comparison to the estimated daily energy requirement; however, their protein intake was much greater than the daily recommended intake. After adjusting for age and gender and for mother's age, body mass index, and total calorie intake, results of the food frequency test showed an association of a higher intake of meat, meat products, milk and milk products with greater BMD of total femur, femur neck, and lumbar spine of children. In addition, exercise was positively associated with higher BMD. Regression analysis showed a positive association of BMD with age, male gender, exercise, and mother's BMD. In conclusion, after adjustment for environmental parameters, maternal BMD had a positive influence on BMD in daughters and sons. This finding suggests that parents need to check their BMD in order to determine whether their children are at increased risk of low BMD.

Effect of motion path of downburst on wind-induced conductor swing in transmission line

  • Lou, Wenjuan;Wang, Jiawei;Chen, Yong;Lv, Zhongbin;Lu, Ming
    • Wind and Structures
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    • v.23 no.3
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    • pp.211-229
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    • 2016
  • In recent years, the frequency and duration of supply interruption in electric power transmission system due to flashover increase yearly in China. Flashover is usually associated with inadequate electric clearance and often takes place in extreme weathers, such as downbursts, typhoons and hurricanes. The present study focuses on the wind-induced oscillation of conductor during the process when a downburst is passing by or across a specified transmission line. Based on a revised analytical model recently developed for stationary downburst, transient three-dimensional wind fields of moving downbursts are successfully simulated. In the simulations, the downbursts travel along various motion paths according to the certain initial locations and directions of motion assumed in advance. Then, an eight-span section, extracted from a practical 500 kV ultra-high-voltage transmission line, is chosen. After performing a non-linear transient analysis, the transient displacements of the conductors could be obtained. Also, an extensive study on suspension insulator strings' rotation angles is conducted, and the electric clearances at different strings could be compared directly. The results show that both the variation trends of the transient responses and the corresponding peak values vary seriously with the motion paths of downburst. Accordingly, the location of the specified string, which is in the most disadvantageous situation along the studied line section, is picked out. And a representative motion path is concluded for reference in the calculation of each string's oscillation for the precaution of wind-induced flashover under downburst.

Wireless operational modal analysis of a multi-span prestressed concrete bridge for structural identification

  • Whelan, Matthew J.;Gangone, Michael V.;Janoyan, Kerop D.;Hoult, Neil A.;Middleton, Campbell R.;Soga, Kenichi
    • Smart Structures and Systems
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    • v.6 no.5_6
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    • pp.579-593
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    • 2010
  • Low-power radio frequency (RF) chip transceiver technology and the associated structural health monitoring platforms have matured recently to enable high-rate, lossless transmission of measurement data across large-scale sensor networks. The intrinsic value of these advanced capabilities is the allowance for high-quality, rapid operational modal analysis of in-service structures using distributed accelerometers to experimentally characterize the dynamic response. From the analysis afforded through these dynamic data sets, structural identification techniques can then be utilized to develop a well calibrated finite element (FE) model of the structure for baseline development, extended analytical structural evaluation, and load response assessment. This paper presents a case study in which operational modal analysis is performed on a three-span prestressed reinforced concrete bridge using a wireless sensor network. The low-power wireless platform deployed supported a high-rate, lossless transmission protocol enabling real-time remote acquisition of the vibration response as recorded by twenty-nine accelerometers at a 256 Sps sampling rate. Several instrumentation layouts were utilized to assess the global multi-span response using a stationary sensor array as well as the spatially refined response of a single span using roving sensors and reference-based techniques. Subsequent structural identification using FE modeling and iterative updating through comparison with the experimental analysis is then documented to demonstrate the inherent value in dynamic response measurement across structural systems using high-rate wireless sensor networks.

The Human Performance Degradation in Vigilance due to Prolonged and Monotonous Tasks (경계(警戒) 임무(任務) 담당자(擔當者)의 시간지연(時間遲延)에 따르는 인간(人間) 성능(性能)의 변화(變化)에 대(對)한 연구(硏究) 및 개선방안(改善方案))

  • Myun-Woo,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.11 no.1
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    • pp.27-34
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    • 1974
  • This study is aimed at a validation of the vigilance simulation model which was proposed earlier (2). The model estimates a perceived danger value, an alertness level and the probability of detection at a given elapsed time of vigilance. Twenty-nine male and seven female subjects were given a simple task. They were asked to detect a number(four numbers out of six digits in the telephone directory which have the probability of occurrence in the range of 0.0010-0.0018) in six different experimental conditions, for periods of two to three hours. Analysis of the experiments showed that although the mean detection rate varied slightly in two hours, the within-subject variance and the number of cyclic performance fluctuations increased significantly. A primal factor that affects the performance seems to be the frequency of target occurrence. By curve fitting, the relation between the probability of detection and the percentages of danger event occurrence was derived; $y=0.50(1-{\varepsilon}^{-50x^2})+0.39$. Assuming the equation represents the normal detection rate(100% performance), the Relative Vigilance Performance Rating was calculated. This rating method could be a useful criterion in selecting and training of the vigilance personnel. The results show that the simulation model is a good estimator of human a performance when the probability of danger occurrence is greater than 0.0015; it gives a good reference for improving the vigilance system. Suggestions are made that (1) the validity of proposed functional equations over the extended range of danger probability be studied, (2) an analysis of the cyclic fluctuations of the alertness level be accomplished, and (3) the cost functions of detection reliability be included in any future model.

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A Pilot Study for the Practical Usage of Traditional Korean Medicine Diagnostic Methods in Women Infertility (여성 불임환자에 대한 한의 진단도구 활용을 위한 기초연구)

  • Yoo, Jeong-Eun;Yoo, Dong-Youl
    • The Journal of Korean Obstetrics and Gynecology
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    • v.28 no.1
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    • pp.102-112
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    • 2015
  • Objectives: This study was performed to obtain reference data of traditional Korean medicine diagnostic methods for the practical usage in women infertility. Methods: The study involved 38 female patients of age 20-38 years that had diagnosed of infertility. All the subjects answered to pattern identification questionnaire and Questionnaire for the Sasang Constitution Classification (QSCC II). Pattern identification scores and constitution types have been analyzed with variables of infertility factors and age. Statistical analysis was performed by adopting descriptive and inferential tests. Results: In pattern identification questionnaire analysis, the patterns were observed in order of frequency: liver stasis; blood deficiency; kidney-yang deficiency; kidney-yin deficiency; damp-heat; blood stasis; and phlegm. The group, less than 35 years old, had the higher average score of liver stasis (p<0.05). Also, the group with tubal and peritoneal factors, had the higher average score of blood deficiency (p<0.05). In QSCC II analysis, So-yang type had the higher average score of liver stasis, kidney-yang deficiency, and kidney-yin deficiency. So-eum type had the higher average score of liver stasis, kidney-yang deficiency, kidney-yin deficiency, and blood deficiency. While, Tae-um type had the higher average score of liver stasis and phlegm. Conclusions: We would accumulate the clinical data for the practical usage of traditional Korean medicine diagnostic methods in women infertility.

Design of Standard Value Intracranial Translucency of Fetus in Early Pregnancy Using Ultrasound (초음파를 이용한 임신초기 태아의 두개내투명대 표준치 제시)

  • Yang, Sung-Hee;Kim, Changsoo
    • Journal of the Korean Society of Radiology
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    • v.15 no.2
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    • pp.131-137
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    • 2021
  • The purpose of this study was to present the reference value of the intracranial translucency(IT) of the fetus using the mid sagittal plane of the post brain in the early pregnancy ultrasound screening test and to find the clinical significance. From August 2018 to February 2020, the IT of 1529 singleton fetus whose crown lump length were 40.6 mm to 78.3 mm in length among the mothers undergoing regular checkups at Hospital I were measured and analyzed retrospectively. As the crown lump length increased, the IT showed a 54.3% explanatory power and tended to increase(p<0.001). In addition, through frequency analysis, the standard value for the percentile of the IT by gestational weeks was calculated. As a result, it was possible to establish a standard value for Koreans with an IT, and it will be usefully applied as an auxiliary screening test for spina bifida in the evaluation of fetal post brain in early pregnancy.

Design and Fabrication of A Wide-Band Dual-Polarization Stacked Patch Array Antenna for Satellite SAR Applications (위성 SAR용 광대역 이중편파 적층형 패치 배열 안테나 설계 및 제작)

  • Lee, Jae-Min;Yu, Je-Woo;Chae, Heeduck;Lee, YuRi;Jung, Hwa-Young;Kim, JongPil;Park, Jongkuk
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.2
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    • pp.72-78
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    • 2021
  • This paper proposes a wide-band dual-polarization stacked patch array antenna for satellite SAR system applications. The array antenna was designed for loss minimization and wide-band characteristics to enhance the performance of the SAR system and optimize it for active return loss in applications to active phased arrays. The fabricated array antenna showed a performance of 19.26%/19.79% fractional bandwidth within the -10 dB reference level of the active return loss and showed loss characteristics of 0.797 dB/0.799 dB averaged within the operational frequency for both H/V-polarization cases. The pattern performance was verified by comparing the measured patterns with the calculated patterns obtained by the array factor.