• Title/Summary/Keyword: CR39

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소프트 키보드의 터치 위치별 지각 불편도 및 근전도 분석 (Analysis of Perceived Discomfort and EMG for Touch Locations of a Soft Keyboard)

  • 최보리;정기효
    • 대한산업공학회지
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    • 제39권2호
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    • pp.99-104
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    • 2013
  • With diversity of mobile services (e.g., messenger, and social network service) on smartphone, the demand of text input using a soft keyboard is increasing. However, studies on subjective and physiological responses of users for various touch locations are lacking. The present study investigated the ergonomic effects according to touch locations of a soft keyboard on smartphone. The experiment of the present study measured perceived discomfort using Borg's CR-10 scale and electromyography (EMG) on forearm (abductor pollicis longus, and extensor digitorum communis) and thumb (abductor pollicis brevis, and first dorsal interossei) muscles. Perceived discomfort was significantly varied from 0.7 (extremely weak discomfort) to 2.5 (weak discomfort) depending on touch locations. %MVC according to touch locations was only significant at abductor pollicis brevis which varied from 10% to 23%. The experimental results of the present study can be utilized in the ergonomic design of a soft keyboard.

저합금강판의 열간프레스성형에 따른 상변태 전산 해석

  • 복현호;김훈동
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2010년도 춘계학술발표대회
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    • pp.39.2-39.2
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    • 2010
  • Recently, hot stamping process has been paid attention greatly by automobile makers in accordance with the fuel efficiency and environmental issues as well as crash safety issue. The hot-stamped parts, however, demand extreme mechanical properties such as tensile strength of over 1470 MPa or equivalently Vickers hardness of around 450. In this work, to meet the demand efficiently, a method to predict mechanical property of hot-stamped parts based on numerical phase transformation scheme has been proposed associated with the thermo-mechanical coupled finite element analysis. This work deals with various phase transformation equations and validates them to select appropriate model for 0.2C-0.1Si-1.4Mn-0.5Cr-0.01Mo-0.002B steel sheet. The authors show that an efficient method saving time and cost to develop hot-stamped automobile parts ensuring suitable mechanical properties such as Vickers hardness and strength.

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방광요관 역류증 환아의 단회뇨에서 요단백 및 효소 배설 측정 (Urinary Protein and Enzyme Excretion of Spot Urine in Children with Vesicoureteral Reflux)

  • 윤정림;구자욱
    • Childhood Kidney Diseases
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    • 제13권1호
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    • pp.56-62
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    • 2009
  • 목 적 : 방광요관 역류증 환아의 단회뇨에서 요단백 및 효소(Microalbumin, NAG, ${\beta}_2$ MG)의 배설을 측정하여 방광요관 역류의 정도나 신손상을 조기에 예측 할 수 있는 지표로 의미가 있는지 알아보고자 하였다. 방 법 : 요로감염증으로 진단 받았던 91명의 환아 중 방광요관 역류와 신결손이 없었던 환아 I군 (n=62), 신결손은 없이 방광요관 역류만 있었던 환아는 II군(n=10), 신결손 및 방광요관 역류증을 모두 가지고 있었던 환아는 III군(n=19)으로 분류하여 아침첫 소변에서 microalbumin, NAG, ${\beta}_2$ MG를 측정하여 평균값을 비교하였다. 방광요관 역류 grade에 따라 VUR Grade I, II, III은 역류의 정도가 낮은 군으로 VUR grade IV, V는 역류가 높은 군으로 분류하여 요중 Microalbumin, NAG, ${\beta}_2$ MG값을 비교하였다. 결 과 : 단회뇨에서 측정한 microalbumin 값은 역류와 신결손이 있는 군이 없는 군과 비교하여 의미있게 증가되어 있었다(microalbumin: $42.3{\pm}27.2\;mg/gCr$ VS $25.2{\pm}10.9\;mg/gCr$, P<0.05). 단회뇨${\beta}_2$ MG, NAG의 평균값의 각 군간의 비교에서는 통계학적인 유의성이 없었다. 방광요관 역류가 높은 군에서 낮은 군보다 microalbumin 측정치가 의미 있게 증가되었다($23.4{\pm}7.7\;mg/gCr$ VS $39.3{\pm}22.1\;mg/gCr$, P<0.05). 결 론: 요로감염으로 진단받은 방광요관 역류증 환아에서 역류 정도와 역류성 신병증으로의 진행 여부를 예측하는 지표로 단회뇨의 microalbumin 측정이 유용하며, 외래에서 추적 관찰에 간편하게 이용할 수 있고 환아와 보호자의 순응도 상승에도 효과가 있을 것으로 기대된다.

일부 젊은 성인여자의 Fe, Zn, Cu, Mn, Se, Mo 및 Cr의 식사섭취, 혈청농도 및 소변배설 (Dietary Intakes, Serum Concentrations, and Urinary Excretions of Fe, Zn, Cu, Mn, Se, Mo, and Cr of Korean Young Adult Women)

  • 김경희;임현숙
    • Journal of Nutrition and Health
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    • 제39권8호
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    • pp.762-772
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    • 2006
  • This study was conducted to investigate dietary intakes, serum concentrations, and urinary excretions of iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), selenium (Se), molybdenum (Mo), and chromium (Cr) of Korean young adult women. A total of 19 apparently healthy young adult women aged in their twenties or thirties participated voluntarily. One-tenth of all foods they consumed for 3 consecutive days were collected, all urine excreted for the same 3 days was gathered, and fasting venous blood was withdrawn for the trace mineral analyses. Of the food, blood, and urine samples, the contents of Zn, Cu, Mn, Se, Mo, and Cr were analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS) and that of Fe by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) after wet digestion. The intake of Fe, $6.94{\pm}2.18mg$, did not meet the estimated average requirement (EAR) for Korean women aged 20-29 years old. On the contrary, the intakes of Zn ($9.35{\pm}4.95mg$), Cu ($1.18{\pm}0.26mg$), and Mn ($3.69{\pm}0.69mg$) were sufficient for each respective EAR. However, some of the subjects did not take the EAR for Zn. The Se intake, $41.93{\pm}9.28{\mu}g$, however, was almost similar to the EAR for Se. Although there are no references for Mo and Cr, the intakes of these minerals ($134.0{\pm}49.1\;and\;136.5{\pm}147.9{\mu}g$, respectively) seemed to be excessively sufficient. Serum Fe concentration, $88.7{\pm}36.8{\mu}g/dL$, seemed to be a little bit lower than its reference median but within its normal range. Approximately one-fourth of the subjects were in anemic determined by Hb and Hct and below the deficiency serum level of Fe, $60{\mu}g/dL$. In addition, serum Se concentration, $3.73{\pm}0.60{\mu}g/dL$, was also below its reference median and normal range. However, serum concentrations of Zn ($99.6{\pm}30.6{\mu}g/dL$) and Mo ($0.25{\pm}0.10{\mu}g/dL$) were fairly good compared to each reference median. The status of Cu could be determined as good although its serum concentration ($91.6{\pm}14.6{\mu}g/dL$) was slightly below its reference median. Since there are no decisive reference values, it was not easy to evaluate serum concentrations of Mn ($0.93{\pm}0.85{\mu}g/dL$) and Cr ($8.60{\pm}7.25{\mu}g/dL$). But Mn and Cr status seemed to be adequate. Urinary Fe excretion, $4.48{\pm}1.98{\mu}g/dL$, was pretty much lower than its reference and that of Se, $2.45{\pm}1.17{\mu}g/dL$, was also lower than its average. On the other hand, those of Zn ($42.95{\pm}20.47{\mu}g/dL$) and Cu ($5.68{\pm}1.50{\mu}g/dL$) were flirty good. In case of Mn, urinary excretion, $0.31{\pm}0.09{\mu}g/dL$, was much greater than its reference. Urinary excretions of Mo ($7.48{\pm}2.95{\mu}g/dL$) and Cr ($1.37{\pm}0.41{\mu}g/dL$) were very higher compared to each reference. The results of this study revealed that Korean young adult women were considerably poor in Fe status, a bit inadequate in Se status, partly inadequate in Zn status, and flirty good in Cu, Mn, Mo and Cr status. However, there was a problem of excessive intakes of Mo and Cr. It, therefore, should be concerned to increase the intakes of Fe, Se and Zn but to decrease Mo and Cr consumption for young adult women.

축하중을 고려한 마이크로파일의 임계좌굴특성 (Critical Buckling Characteristics of Micropiles Under Axial Loads)

  • 정현식;노인수;이영생
    • 한국지반공학회논문집
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    • 제31권9호
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    • pp.39-51
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    • 2015
  • 근래 구조물 기초보강을 위한 마이크로파일공법의 적용사례가 점차 증가하고 있으며, 이에 따른 관련 연구가 다수 수행되고 있다. 그러나 국내 연구는 대부분 Case. I, II-Type의 지지거동에 국한되어 마이크로파일 자체의 구조적 검토에 대한 연구는 미미한 실정이다. 따라서 본 논문에서는 국내에서 주로 사용되는 마이크로 파일에 대한 각각의 강봉 및 그라우트조건에 따른 좌굴특성을 검토하였다. 검토결과 마이크로파일 직경이 작을수록 지반의 임계좌굴점착력($C_{ucr}$)는 증가하게 되며, 특히 임계좌굴길이($L_{cr}$) 이하에서는 마이크로파일 길이가 길수록 임계좌굴하중($P_{cr}$)이 감소함을 알 수 있었다. 또한 축하중을 받는 마이크로파일의 좌굴파괴와 압축파괴 가능성을 구분, 평가할 수 있는 방법을 제시하였다.

Luminance와 동공크기 변화에 따른 렌즈에서 UV 차단효과 연구 (Study of UV-cut Effect by Luminance and Size of pupil in lens)

  • 김용근
    • 한국안광학회지
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    • 제6권2호
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    • pp.17-21
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    • 2001
  • 렌즈에서 UV-A 선 차단 효율을 평가하기 위해 투과율에 의한 가시광 영역 luminance와 luminance에 의한 동공크기를 분석하였다. Luminance(L)에 따른 동공크기(${\Phi}$)는 ${\Phi}=d-e{\cdot}tanh(f{\cdot}logL)$로 주어지고, 동공 크기 (r)에 따른 투과효율은 $T_r(r)=1-gr^2+hr^4$으로 주어진다. $320{\sim}400nm$ 파장 영역인 UV-A에 대한 절대 차단 효율 ${\alpha}$와 제거 지수 $b=(1-{\alpha}){\times}100%$의 식을 유도하였다. UV-cut Lens, CR-39, red color 및 blue color 렌즈에 대한 ${\alpha}$ 값은 각각 0.018, 0.31, 0.273 및 0.153을 얻었고, b값은 각각 98, 69, 72 및 85%을 얻었다.

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HEALTH RISK ASSESSMENT OF HOUSEHOLD EXPOSURE TO INDOOR RADON IN ASSOCIATION WITH THE DWELLING'S AGE

  • Shahrokhi, Amin;Shokraee, Forough;Reza, Ali;Rahimi, Hasn
    • Journal of Radiation Protection and Research
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    • 제40권3호
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    • pp.155-161
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    • 2015
  • Radon is a naturally occurring radioactive gas and a major indoor contribution of exposure to ionizing radiation in dwellings. $^{222}Rn$ is a health hazard gas what is responsible for thousand lung cancer deaths every year. In this study, indoor radon concentrations present in thirty representative houses in Mahallat city, Iran, were determined in order to estimate lung cancer risk associated with residential radon exposure. Long-term passive method, using CR-39, was used to measure the radon concentration. The results showed an association between the age of the dwellings and the indoor radon concentration that was found, in that the concentration of radon tended to increase as the age of the dwelling also increased. The indoor radon concentrations were calculated to be within the range of $23{\pm}2$ to $350{\pm}26Bq{\cdot}m^{-3}$, with an average of $158Bq{\cdot}m^{-3}$. The annual effective dose from inhaled radon and its decay products was calculated between $0.8{\pm}0.1$ and $12.3{\pm}0.9mSv{\cdot}y^{-1}$, with an average of $5.5mSv{\cdot}y^{-1}$. By taking into consideration the EPA recommendation and ICRP statement, the average annual risk of lung cancer from inhaled radon was calculated as 0.09%, 0.06%, 0.01%, and 0.03% for current smokers (CS), those who had ever smoked (ES), never smokers (NS) and the general population, respectively.

지렁이 분말의 급여가 계육의 안전성 및 육계의 생산성에 미치는 영향 (Effects of Feeding Earthworm Meal on the Meat Safety and Performance of Broiler Chicks)

  • 손장호
    • 한국유기농업학회지
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    • 제15권2호
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    • pp.185-194
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    • 2007
  • 본 연구는 지렁이 분말의 첨가가 계육의 안전성 및 육계의 생산성에 미치는 영향을 조사하기 위해서 실시되었다. 총 60수의 1일령 육계에 지렁이 분말 0%(대조구), 0.2% 및 0.4%를 첨가한 사료를 공시하여 7주간 사양시험을 실시하였다. 지렁이분말 $0.4\sim0.6%$ 첨가는 대조구에 비해서 사료섭취량 증가 및 사료 효율을 개선시키는 경향이 인정되었으며, 그 효과는 건조 지렁이분말 0.4% 첨가구가 0.6% 첨가구보다 높게 나타나는 경향이 인정되었다. 건조 지렁이분말의 첨가로 인한 사료효율의 개선은 사육전기보다. 사육 후기인 4-7주 사이에서 뚜렷하게 나타났다. 지렁이분말(EWM) 중의 As, Cd, Cr, Hg 및 Pb는 각각 4.41, 1.23, 1.18, 0.00 및 3.39ppm검출되었지만, 계육 중에는 검출되지 않았다. 결론적으로 육계에 0.4% 지렁이분말(EWM)의 첨가는 육계의 생산성 개선 및 계육의 안전성에는 문제가 없을 가능성이 인정된다.

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Rates of Change to a Positive Result in Subsequent Screening Mammography in Korean Women: A Retrospective Observational Study

  • Bae, Jong-Myon;Shin, Sang Yop;Kim, Eun Hee;Kim, Yoon-Nam;Nam, Chung Mo
    • Journal of Preventive Medicine and Public Health
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    • 제48권1호
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    • pp.48-52
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    • 2015
  • Objectives: This retrospective cohort study aimed at calculating some parameters of changes in the findings of the subsequent screening mammography (SSM) in female Korean volunteers. Methods: The study included screenees aged 30 to 79 years who underwent SSM voluntarily after testing negative in the baseline screenings performed between January 2007 and December 2011. A change to a positive result was defined as category 4 or 5 by using the American College of Radiology Breast Imaging Reporting and Data System. The proportion of results that had changed to positive (CP, %) was calculated by dividing the number of cases with results that were positive in the SSM by the total number of study participants. The rate of results that had changed to positive (CR, cases per 100 000 screenee-months) was calculated by dividing the number of cases with results that were positive in the SSM by the total number of months of the follow-up period. Results: The overall CP and CR in all age groups (n=77 908) were 2.26% and 93.94 cases per 100 000 screenee-months, respectively. The median CP interval in the subjects who had positive SSM results was 30 to 36 months, while that in the age group of 30 to 39 years was shorter. Conclusions: Different screening intervals should be considered among women aged between 30 and 59 years. In addition, a strategy for a screening program should be developed for the age group of 30 to 39 years, in particular.

구례지역 하상퇴적물의 지질집단별 자연배경치에 대한 연구 (The Study of Natural Background of Geologic Units for Stream Sediments in the Gurye Area)

  • 박영석;장우석;김종균
    • 자원환경지질
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    • 제36권4호
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    • pp.275-284
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    • 2003
  • 구례지역의 1차 수계를 대상으로 하상퇴적물을 채취하여 지질집단별 주성분 및 미량성분원소의 자연배경치를 설정하고자 하였다. 하상퇴적물은 구례지형도에서 오염의 우려가 없고 단일지질로 구성된 집수분지를 대표할 수 있는 시료를 1999년 4월과 5월에 걸쳐 채취하였고 화학분석을 실시하였다 유해원소들의 부화정도를 알아보기 위해 tolerable level윽 이용하여 살펴본 결과 일부 지역에서 Ni과 Cr의 함량이 tolerable love의 허용한계치를 초과하는 것으로 나타나는데, 이는 이들 지역의 기반암인 변성암류의 영향으로 인한 것으로 판단된다. 유해금속원소의 종합적인 부화양상을 규명하기 위하여 tolerable level을 이용하여 부화지수를 산출한 격과, 화강편마암지역은 0.39, 반상변정질화강편 마암지역은 0.32, 흑운모편마암지역은 0.42, 혼성편마암지역은 0.41, 응회암지역은 0.30, 안산암지역은 0.46, 역암지역은 0.42, 화강암지역은 0.26으로 매우 낮은 부화지수를 보여주고 있는 것으로 보아 연구지역의 자연배경치는 유해금속원소의 오염에 노출되지 않은 것으로 판단된다.