• 제목/요약/키워드: low level measurement

검색결과 720건 처리시간 0.028초

방사능 존재확인과 정량분석시 최적화된 측정시간의 결정을 위한 계측전략 (Counting Strategies in Radioactivity Measurement for the Monitoring and Screening)

  • 서경원
    • Journal of Radiation Protection and Research
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    • 제23권2호
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    • pp.65-74
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    • 1998
  • 저 준위방사능 계측에서 가장 기본적으로 요구되는 것이 최적 측정시간의 결정이다. 최적화된 계측전략으로 측정시간을 결정하기 위하여 측정시간을 고정하는 방법, 측정값을 고정하는 방법, 시료와 자연계수율 또는 기준준위를 비교하여 측정하는 방법을 비교 검토하는 결정식을 도출하였다. 이 계측전략에서 기기에 주어진 측정조건 즉, 검출기의 효율, 측정기의 용량, 측정기의 최대 및 평균 자연계수율과 관련기준 즉, 기준준위, 검출한계 등을 만족하는 측정시간이 결정된다. 계측전략은 측정시 주어진 조건에서 방사능 존재확인과 정량분석에 대한 시료의 최적 측정시간의 결정을 편리하게 함으로써 일상의 저준위방사능 측정에 유용하게 사용될 것이다.

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Low-Level Laser Therapy including Laser Acupuncture for Non-Specific Chronic Low Back Pain : Protocol for a Systematic Review

  • Yeum, Hyewon;Nam, Dongwoo
    • Journal of Acupuncture Research
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    • 제36권4호
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    • pp.251-255
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    • 2019
  • Background: Low-level laser therapy (LLLT) including laser acupuncture (LA) has been widely used to treat chronic low back pain (CLBP), but there is no critically appraised evidence of the potential benefits. The purpose of this protocol for a systematic review was to enable the evaluation of the effectiveness of LLLT including LA for non-specific CLBP to identify the potential benefits. Methods: The electronic databases MEDLINE (PubMed), Embase (Ovid), the Cochrane Central Register of Controlled Trials (CENTRAL), Korean medical databases (KoreaMed, KMBASE, KISS, NDSL, KISTI, OASIS), the Chinese database (CNKI), and Japanese databases (CiNII, J-STAGE) are recommended. Results: Randomized controlled trials in LLLT including LA should be included in the searches. All data synthesis and subgroup analyses should be conducted using a Review Manager software. The Cochrane risk of bias tool can be used to evaluate methodological quality of the studies. A risk ratio or mean difference with a 95% confidence interval will show the effects of LLLT including LA. Conclusion: The primary outcome would be pain intensity and functional status/disability due to low back pain. The secondary outcome would be a global measurement of recovery or improvement, quality of life and adverse event.

메탄올자동차 배기배출물중의 미연메탄올 및 포름알데하이드 측정 (Measurement of unburned methanol and formaldehyde emissions from methanol fueled vehicles)

  • 명차리;한상순
    • 오토저널
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    • 제13권5호
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    • pp.89-94
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    • 1991
  • In the quantitative analysis of oxygenated exhaust emissions (unburned methanol, formal- dehyde) from methanol fueled vehicles, the oxygen contained in oxygenated exhaust gases lowers the FID (Flame Ionization Detector) response factor of conventional THC analyzer and leads to erroneous HC reading. For correct measurement of various HCs including oxygenated HCs emitted from FFV(Flexible Fuel Vehicle), first of all, the measurement technique of real HC emissions should be established. GC and HPLC-DNPH measuring methods specified by the EPA are used in this paper to analyze unburned methanol and formaldehyde components in the exhaust emissions. In emission test of FFV, unburned methanol and formaldehyde are emitted mostly during cold transient period, and it is shown that formaldehyde emission level is proportional to engine displacements. In view of the HC emission level, vehicle using M85 has 40% advantage over gasoline-fueled vehicle in OMHCE and has a good potential of a low emission vehicle.

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저효율 혈액투석 불이행 측정 도구 개발 (A Study of Low Flux Hemodialysis Noncompliance Indicators and Discriminant Standards, Development of Hemodialysis Noncompliance Measurement - Brief Form(HNCM-BF))

  • 허정
    • 간호행정학회지
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    • 제13권4호
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    • pp.462-472
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    • 2007
  • Purpose: Purpose of the this study is to define the hemodialysis noncompliance Indicators and discriminant standards levels for low Flux Hemodialysis patients and development of Hemodialysis noncompliance measurement - brief form. Method: Data was collected from 269 hemodialysis patients. To establish the hemodialysis noncompliance Indicators and to discriminate standards, 13 hemodialysis nurses and 2 nephrology doctors are participated in professional group. To verify the indicators and discriminant standards, data was ananlyzed by the canonical discriminant analysis method using by SAS 8.3 program. Result: 4 Indicators- interdialysis weight gain(IWG); average of recent 4weeks, serum phophate level, skipping of hemodialysis and hemodialysis time shortening without permission- of hemodialysis noncompliance are established and discriminant standards are developed. Discriminant ability of these 4 noncompliance indicators is 99.7%(p=.000). Hemodialysis noncompliance measurement - brief form has 96.3% discriminant accuracy. Conclusion: Hemodialysis noncompliant patients have high risks. It means that special intervention to noncompliance is needed. Also continuous and objective assessment and standards of noncompliance are needed.

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Precise response time measurement and analysis of liquid crystal displays

  • Glinel, David;Boher, Pierre;Leroux, Thierry
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.723-728
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    • 2006
  • In this paper, we present a new system, OPTISCOPE SA, especially designed for precise measurement of temporal behavior of LCD displays. We show that gray to gray level response time measurement requires a very sensitive and precise instrument and also that the capacity to measure luminance levels and gamma curve can be useful. Quite often, precise evaluation of LCD response time needs also use of low pass and stop band filters to suppress noise and flicker. Low pass filters affect the results but can be corrected for simple temporal behaviors. For complex temporal behaviors like those observed for overdriven LCDs, we show that direct adjustment of theoretical responses is much more efficient to get a complete picture of the temporal behavior of such displays.

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소음 수응 한계를 고려한 저주파 소음평가에 대한 실험적 연구 (A Laboratory Study on Low Frequency Noise Assessment based on Noise Acceptability Limit)

  • 홍승기;김재환;김규태;이수갑
    • 한국소음진동공학회논문집
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    • 제17권8호
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    • pp.736-740
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    • 2007
  • A laboratory study on low frequency noise assessment has been carried out to evaluate the relevance of the weighting curve. Especially, the A-weighting curve which is used in most noise assessments has been evaluated using the acceptability limit in this study. The acceptability limit is one of the indicators in which the subjective responses were well-reflected. For the measurement of the acceptability limit, pure tone stimuli were used in the frequency range between 20 and 200 Hz. The measurement was proceeded in the anechoic chamber to minimize the background noise level. A total of 29 test subjects, who were aged between 19 to 33 years, participated in this study. They had been exposed to various stimuli for about 1 hour by supra-aural earphone. The measurement consisted of two listening sessions: hearing threshold and the acceptability limit session. The results showed that the tendency of the acceptability limit curve was approximately equal to C-weighting curve which had been found to be superior to A-weighting curve in assessment of low frequencies.

저수지 저수량 추정을 위한 위성 SAR 자료의 활용성 (Applicability of Satellite SAR Imagery for Estimating Reservoir Storage)

  • 장민원;이현정;김이현;홍석영
    • 한국농공학회논문집
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    • 제53권6호
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    • pp.7-16
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    • 2011
  • This study discussed the applicability of satellite SAR (Synthetic Aperture Radar) imagery with regard to reservoir monitoring, and tried the extraction of reservoir storage from multi-temporal C-band RADARSAT-1 SAR backscattering images of Yedang and Goongpyeong agricultural reservoirs, acquired from May to October 2005. SAR technology has been advanced as a complementary and alternative approach to optical remote sensing and in-situ measurement. Water bodies in SAR imagery represent low brightness induced by low backscattering, and reservoir storage can be derived from the backscatter contrast with the level-area-volume relationship of each reservoir. The threshold segmentation over the routine preprocessing of SAR images such as speckle reduction and low-pass filtering concluded a significant correlation between the SAR-derived reservoir storage and the observation record in spite of the considerable disagreement. The result showed up critical limitations for adopting SAR data to reservoir monitoring as follows: the inappropriate specifications of SAR data, the unreliable rating curve of reservoir, the lack of climatic information such as wind and precipitation, the interruption of inside and neighboring land cover, and so on. Furthermore, better accuracy of SAR-based reservoir monitoring could be expected through different alternatives such as multi-sensor image fusion, water level measurement with altimeters or interferometry, etc.

무구속적 방법으로 측정된 심전도의 신뢰도 판별 (Quality Level Classification of ECG Measured using Non-Constraint Approach)

  • 김윤재;허정;박광석;김성완
    • 대한의용생체공학회:의공학회지
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    • 제37권5호
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    • pp.161-167
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    • 2016
  • Recent technological advances in sensor fabrication and bio-signal processing enabled non-constraint and non-intrusive measurement of human bio-signals. Especially, non-constraint measurement of ECG makes it available to estimate various human health parameters such as heart rate. Additionally, non-constraint ECG measurement of wheelchair user provides real-time health parameter information for emergency response. For accurate emergency response with low false alarm rate, it is necessary to discriminate quality levels of ECG measured using non-constraint approach. Health parameters acquired from low quality ECG results in inaccurate information. Thus, in this study, a machine learning based approach for three-class classification of ECG quality level is suggested. Three sensors are embedded in the back seat, chest belt, and handle of automatic wheelchair. For the two sensors embedded in back seat and chest belt, capacitively coupled electrodes were used. The accuracy of quality level classification was estimated using Monte Carlo cross validation. The proposed approach demonstrated accuracy of 94.01%, 95.57%, and 96.94% for each channel of three sensors. Furthermore, the implemented algorithm enables classification of user posture by detection of contacted electrodes. The accuracy for posture estimation was 94.57%. The proposed algorithm will contribute to non-constraint and robust estimation of health parameter of wheelchair users.

스마트케어 비만관리에서 자가 측정 빈도 수준의 효과 (The effect of the self-measurement frequency levels on SmartCare obesity management)

  • 이창희;장병윤
    • 한국산학기술학회논문지
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    • 제16권3호
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    • pp.1972-1980
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    • 2015
  • 이 연구의 목적은 한국에서 2011년 3월 9일 부터 2013년 4월 3일 사이에 수행된 스마트케어 비만 관리 시범사업의 효과를 분석하는 것이었다. 연구에 등록된 212명 참여자 중에서 6개월 동안의 스마트케어 서비스 기간이 종료되는 시점까지 자가 체중 측정을 모두 완료한 147명을 최종 분석 대상자로 하였다. 평가를 위한 자가 측정 그룹은 6개월 기간의 월 평균자가 측정 빈도를 균등하게 나누어 3그룹(Low, Middle, High)으로 분류를 하였으며 평가 대상 지표는 스마트케어 시스템으로 전송된 체중과 BMI(Body Mass Index)로 하였다. 체중과 BMI의 월별 평균은 High 그룹이 Middle 과 Low 그룹보다 더 많이 감소하였으며(M5: High>Middle>Low) 통계적으로도 유의하게 차이가 있는 것으로 나타났다 (p< 0.05). 결론적으로, 체중과 BMI의 개선 효과 분석은 자가 측정 빈도 수준이 높을 때 더 개선 효과가 있는 것으로 나타났다.

벽식구조 표준시험동에서 중량충격음장에 관한 연구 (Investigation of the heavy-weight floor impact sound field in a testing building with bearing wall structure)

  • 유승엽;이신영;전진용
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 춘계학술대회논문집
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    • pp.969-973
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    • 2007
  • The heavy-weight floor impact sound field of the receiving room in a testing building with bearing wall structure was investigated using bang machine and impact ball. The sound field was investigated through the impact sound pressure level distribution by the field measurement and computational analysis. Predicted sound field using the computational analysis agree with measurement result in the low frequency band. Result shows that standard deviations of the single number rating value are about 2dB in each impact source. Particularly, impact sound pressure level at 120cm height in 63Hz octave band was 5dB lower than spatial averaging value. It was found that receiving positions in the ministry of construction and transportation notice should be reconsidered.

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