• 제목/요약/키워드: inversion strength

검색결과 64건 처리시간 0.023초

계류기구로 관측한 대구시 야간 안정층 특성에 관한 사례연구 (Characteristic of the Nocturnal Inversion Layer observed by Tethersonde in Daegu)

  • 김희종;윤일희;권병혁;허만천
    • 한국환경과학회지
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    • 제11권3호
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    • pp.155-160
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    • 2002
  • Using measured data at Daegu by tethersonde for the period of 1984∼1987, we have investigated the lower atmospheric boundary layer structure including relationships between inversion layer and meteorological factors(wind and temperature), and the inversion strength and inversion height. The inversion layer was defined from the vertical temperature profile and its strength was analyzed with the wind shear as well as the vertical temperature gradient. From October to January, measured inversion layer isn't destroyed, however, in June, after sun rise, it is destroyed by surface heating and mixed layer is developed from surface. According to Pasquill stability classes, the moderately stable cases dominated. It's the larger vertical temperature gradient the lower SBL height. We have introduced B(bulk turbulence scale) which indicated SBL height. It's larger B, the higher SBL height and vice versa. It was noted that the bulk turbulence scale (B) is appropriate to determine the stable boundary layer height.

정상 성인 여성의 발목관절에서 근력 균형과 관절위치감각의 상관관계 (The Relationship between Strength Balance and Joint Position Sense Related to Ankle Joint in Healthy Women)

  • 고유민;정미숙;박지원
    • The Journal of Korean Physical Therapy
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    • 제23권2호
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    • pp.23-29
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    • 2011
  • Purpose: The purpose of this study was to determine whether there is a relationship between strength balance and joint position sense related to the ankle joint in healthy women. Methods: Twenty-six healthy women were recruited. Isokinetic strength and joint position sense (JPS) were measured using a Biodex System 4 pro Dynamometer and a Biodex Advantage Software Package. Prior to measuring the JPS and isokinetic strength, the dominant foot was determined according to the Waterloo Footedness Questionnaire. After the JPS test, isokinetic strength was evaluated in velocity $60^{\circ}s$, including practice trial ($90^{\circ}s$). Using the measured isokinetic strength, a Strength Balance Index (SBI) was calculated. Results: Relative to the SBI, the degree of imbalance was varied; but there were imbalances. For each starting position, JPS error showed no significant differences (p>0.05). The relationship between SBI and JPS was found during the inversion to eversion process, eversion to inversion, and dorsi flexion to plantar flexion. Conclusion: There are moderate to mild relationships between JPS and SBI during ankle movement. It is suggested that to prevent ankle injuries, strength balance should be considered along with the other potential factors including anatomical alignment, proprioception, and soft tissues problems.

관측사례로 검증한 영동강풍 발생조건 분석 (Analysis on the Yeongdong Downslope Windstorms Generation Condition Verified by Observation Cases)

  • 박유정;한윤덕
    • 대기
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    • 제31권4호
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    • pp.405-420
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    • 2021
  • Forest fire happens every year at Yeongdong, Gangwon-do, due to the strong local wind during the spring time and it causes a huge damage. This wind is named "Yangganjipung" or "Yanggangjipung" that blows along Yeongdong. However, the occurrence conditions of the wind have been still unclear. To identify the occurrence mechanism of local strong wind through three-dimensional observation data, Gangwon Regional Meteorological Administration performed Joint Gangwon-Yeongdong 3D Observation Project in 2020. The special observation was carried out for 6 times from March to April. The observation data was analyzed by focusing on the structure of synoptic pressure distribution and inversion layer. The result showed that the strength of wind is different depending on the latitude of low pressure, intensity of inversion layer, and changes on height in the south-high and north-low pressure distribution. As the interval of the upper and lower parts of the inversion layer was narrow, the strength of the wind became stronger, which is one of the observational characteristics of the springtime wind pattern at Yeongdong, Gangwon-do. In future, the clear mechanism of the local wind in the Yeongdong during the spring time is expected to be verified based on the accumulative observation data and close analysis.

New Separators Based on Non-Polyolefin Polymers for Secondary Lithium Batteries

  • Seol, Wan-Ho;Lee, Yong-Min;Lee, Jun-Young;Han, Young-Dal;Ryu, Myung-Hyun;Park, Jung-Ki
    • 전기화학회지
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    • 제10권2호
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    • pp.82-87
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    • 2007
  • New porous separators based on non-polyolefin materials including the blend of poly (vinyl chloride) (PVC)/poly (vinylidene fluoride-co-hexafluoropropylene) (P(VdF-co-HFP)/poly(methyl methacrylate) (PMMA), and the porous separator based on poly (vinylidene fluoride) (PVdF) were prepared by phase inversion method. The porosity and morphology were controlled with phase inversion rate, which is governed by the relative content of non-solvent and solvent in coagulation bath. To enhance tensile strength, the solvent pre-evaporation and uni-axial stretching processes were applied. The ionic conductivity was increased with increasing stretching ratio, and tensile strength was increased with increasing solvent pre-evaporation time and stretching ratio. The 200% stretched PVdF separator showed 56 MPa of tensile strength, and the ionic conductivity of the stretched PVdF separator was $8.6{\times}10^{-4}\;S\;cm^{-1}\;at\;25^{\circ}C$.

역전층이 영동 지역의 활강풍에 미치는 영향에 관한 민감도 수치실험 연구 (A Numerical Sensitivity Experiment of the Downslope Windstorm over the Yeongdong Region in Relation to the Inversion layer of Temperature)

  • 이재규;인소라
    • 대기
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    • 제19권4호
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    • pp.331-344
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    • 2009
  • A sensitivity study has been performed using ARPS (Advanced Regional Prediction System) version 5.2.10 in a downslope windstorm case of 12-13 February 2006. The purpose of this study was to find out the role of the inversion layer of temperature mainly in relation to the strength of the downslope winds over the Yeongdong region located downstream of the Taebaek mountains. Under the conditions of N (Brunt-$V{\ddot{a}}is{\ddot{a}}la$ frequency)=0.008 and N=0.016, the effects of the presence of the inversion layer, its variation of height of the layer, and the depth of the layer were identified. The sensitivity experiments suggested that the inversion layer effected the downstream wind speed of the mountains under both conditions of N=0.008 and N=0.016, and notably when the inversion layer was located near the mountain crest the downstream wind speed of the mountains was strong (~ $27ms^{-1}$) only under the condition of N=0.016. In addition, when the atmosphere was rather stable (N=0.016) and the depth of the layer was relatively thin (765 m) the downstream wind speed of the mountains was the strongest (~ $30ms^{-1}$) among the sensitivity experiments.

액체암모니아 처리 면직물의 염색성 - 저온형과 고온형 반응성 염료에 의한 염색물의 색상강도 - (Dyeability of Cotton Fabrics Treated with Liquid Ammonia - Color strength of the dyeings with low-temperature and high-temperature reactive dyes -)

  • 전성기;이창수;임용진;김태경
    • 한국염색가공학회지
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    • 제16권2호
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    • pp.1-7
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    • 2004
  • The dyeability of cotton fabrics treated with liquid ammonia was investigated using low-temperature and high-temperature reactive dyes. From the results of dyeing rates of direct dye, the inversion time was shown at 600 hours at $40^{\circ}C$, and however it was shown at 10 minutes at $80^{\circ}C$. This was applied to reactive dyeings. In the low-temperature reactive dyes, the color strength of the fabrics treated with liquid ammonia was lower than that of mercerized fabrics. By contrast, in the high-temperature reactive dyes, the color strength of the fabrics treated with liquid ammonia was higher than that of mercerized one.

Magnetic Field Inversion and Intra-Inversion Filtering using Edge-Adaptive, Gapped Gradient-Nulling Filters: Applications to Surveys for Unexploded Ordnance (UXO)

  • Rene, R.M.;Kim, K.Y.;Park, C.H.
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2006년도 공동학술대회 논문집
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    • pp.9-14
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    • 2006
  • 자기쌍극자 모멘트의 깊이, 방향, 크기 등에 관한 평가는 자기탐사자료로부터 폭발물과 기타 자성체를 구분하는데 유용한 정보를 제공한다. 이러한 평가는 지질학적 잡음, 자기분산체, 주변 쌍극자기장 중첩 등의 이유로 방해를 받을 수 있다. 임의의 극성을 갖는 단일 혹은 다중 쌍극자 이상체의 효과적 계산을 위하여, 역산내부 필터 및 배경 자기장의 구배 평가를 포함하는 개선된 역산법을 개발하였다. 관측값들은 보간하여 격자화하였으며, 관측점으로부터 가장 가까운 계산점만을 사용하도록 표시하였다. 이러한 자료에 역산내부 필터를 적용하기 위하여는 빈간격 필터가 필요하다. 게다가 상당히 빈 곳이 많은 자료나 조사지 가장자리 및 구석 부분 자료들을 처리하기 위해서는 역산내부 필터를 수정하여야 한다. 이러한 목적으로 가장자리에 적용가능한 빈간격 구배제거 필터를 고안하고 시험하였다. 한국 속초의 청초호와 미국 매릴랜드의 육군 애벌딘 무기시험장에서 기록한 자기탐사자료에 적용한 결과를 소개한다.

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Assessment and Comparison of Isokinetic Strength of Hip, Knee and Ankle Joints in Young Adults

  • Kim, Yong Hwan;Jee, Hae Mi
    • 국제물리치료학회지
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    • 제9권1호
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    • pp.1426-1434
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    • 2018
  • This study was conducted to observe the isokinetic strength (IS) of the hip, ankle, and knee joints in young age groups. Thirty eight men and thirty one women with mean age of $30.4{\pm}3.5$ and $32.8{\pm}4.4years$, respectively, were enrolled in this study. Measurements of hip flexion, extension, abduction, and adduction at $30^{\circ}/sec$, Knee flexion and extension at $60^{\circ}/sec$, ankle inversion, eversion, plantarflexion, and dorsiflexion $30^{\circ}/sec$ were conducted. Absolute IS (Nm), relative IS (Nm/kg), strength ratios, correlations between movements were observed. Significant differences in absolute and relative strength were observed between groups in all movement except in the relative ankle strength. Relative isokinetic strength ratios of hip flexion/extension were .45 and .55, knee flexion/extension were .84 and .89, ankle dorsi/plantarflexion were .30 and .29, and ankle eversion/inversion were .86 and .84 for men and women, respectively. In the hip extension, men had about three times the body weight, and women had about 2.5 times the strength. The abduction muscle had about 1.5 times the body weight of both men and women. Height and body weight showed the significantly strong correlating relationship with hip (r, .76-.86) and knee (r, .67-.84) strength. However, ankle strength showed the comparatively correlating relationship, especially in women (r, .03 - .36). Similar age and physique characteristics of female and male groups could provide useful isokinetic strength reference values for developing the exercise program for healthy and rehabilitation groups.

Enhancement of the Ionic Conductivity and Mechanical Strength of Micro-porous Separator by Uni-axial Drawing

  • Lee Je-An;Seol Wan-Ho;Lee Yong-Min;Park Jung-Ki
    • 전기화학회지
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    • 제9권1호
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    • pp.29-33
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    • 2006
  • A new porous separator based on poly(vinyl chloride) (PVC)/poly(vinylidene fluoride-co-hexafluoro-propylene) (P(VdF-co-HFP)/poly(methyl methacrylate) (PMMA) was prepared by a phase inversion method. To enhance mechanical property, the membrane was stretched uniaxially at high temperature. Tensile strength and ionic conductivity were measured for various draw ratios. The tensile strength and ionic conductivity were increased with increasing draw ratio. The tensile strength of the separator reached 52MPa after stretching to draw ratio of 5, and the ionic conductivity of the separator was increased from $1.9Xs10^{-4}S/cm\;to\;4.6X10^{-4}S/cm\;at\;25^{\circ}C$. The stretched separator immersed in liquid electrolyte was electrochemically stable up to 4.7 V. The cell based on the stretched separator was maintained at about 99% of the initial discharge capacity after 10th cycle operation at 0.2C rate.

등속성 운동검사를 이용한 정상 한국인 성인에서의 발목관절 근력 측정 (Measurement of Muscle Strength of Ankle Joint Using Isokinetic Dynamometer in Normal Korean Adults)

  • 최승명;박지강;하윤원;조병기
    • 대한족부족관절학회지
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    • 제19권4호
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    • pp.142-150
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    • 2015
  • Purpose: Restoration of ankle stability through the strengthening exercise of peroneus muscles is considered an important factor for achievement of successful outcomes, in the rehabilitation program following ankle ligament injuries. However, there were few definitive data on normal muscle strength, including eversion power by peroneus muscles. This study was conducted to evaluate the muscle strength of ankle joint measured using an isokinetic dynamometer in normal Koreans. Materials and Methods: Sixty adults (120 ankles) were recruited and divided into three groups (20 in their twenties, 20 in thirties, and 20 in forties). Each group consisted of 10 males and 10 females. The selection criteria were no history of ankle injury and no evidence of instability. The peak torque, total work, and deficit ratio were measured using the Biodex$^{TM}$ (Biodex Medical Systems). Differences in muscle strength by age, gender and dominant versus non-dominant side were analyzed. Results: The peak torque of dorsiflexion was average 31.5 Nm at $30^{\circ}/s$ of angular velocity and 18.8 Nm at $90^{\circ}/s$; average 69.3 Nm ($30^{\circ}/s$) and 42.4 Nm ($90^{\circ}/s$) on plantarflexion; average 19.6 Nm ($30^{\circ}/s$) and 10.8 Nm ($90^{\circ}/s$) on inversion; average 12.9 Nm ($30^{\circ}/s$) and 8.0 Nm ($90^{\circ}/s$) on eversion. The deficit ratio of strength in women was average 61.1% of men on dorsiflexion; average 66.2% on plantarflexion; average 48.5% on inversion; average 55.4% on eversion. The deficit ratio in non-dominant foot was average 88.6% of dominant foot on dorsiflexion; average 90.1% on plantarflexion; average 85.1% on inversion; average 85.6% on eversion. Conclusion: The muscle strength of the ankle joint showed a tendency to weaken with age. There were significant differences in muscle strength by gender and dominancy. Further studies for comparison of patients with ankle instability, a comparison between before and after surgery for instability, the correlation between clinical outcomes and the recovery in muscle strength will be needed.