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Sampling Study on Environmental Observations: Precipitation, Soil Moisture and Land Cover Information

  • 유철상
    • Journal of Environmental Science International
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    • v.5 no.2
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    • pp.103-112
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    • 1996
  • Observational date is integral in our understanding of present climate, its natural variability and any cnange roue to anturopogenic effects. This study incorporates a brief overview of sampling requirements using data from the first ISLSCP Field Experiment (FIFE) in 1987, which was a multi-disciplinary field experiment over a 15km grid in Konza Prairie, USA. Sampling strategies were designed for precipitation and soil moisture measurements and also detecting land cover type. It was concludes that up to 8 raingages would be needed for valuable precipitation measurements covering the whole FIFE catchment, but only one soil moisture station. Results show that as new gages or station are added to the catchment then the sampling error is reduced, but the Improvement in error performance is less as the number of gages or stations increases. Sampling from remoteiy sensed instruments shows different results. It can be seen that the sampling error at 1arger resolution sizes are small due to competing error contribution from both commission and omission error.

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Unequal Distance Sampling Technique to Design Velocity-Type Respiratory Air Flow Transducer (속도 계측형 호흡기류센서 설계를 위한 비균등 샘플링 기법)

  • 김경아;이태수;차은종
    • Journal of Biomedical Engineering Research
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    • v.25 no.5
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    • pp.351-359
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    • 2004
  • Velocity-type repisratory air flow transducer measures dynamic pressure converted from air velocity based on the we1l-known Bernoulli's principle. It requires multiple velocity sampling holes on the flow plane. Measurement error theoretica1ly estimated by computer simulation was demonstrated to significantly reduce by unequally locating the velocity sampling holes. The flow plane was divided into multiple equi-area rings and the sampling holes were located on the circles also equally dividing each ring's area, which decreased measurement error down to 1/5 of the simple equi-radius ring division method. Also, less than 1 % relative error was estimated with 4 or more sampling holes. The present technique was less sensitive by <1/2 to the velocity profile change compared to the euqi-radius sampling. Therefore, the present unequal distance velocity sampling technique should be of great use to design the structure of the velocity-type respiratory air flow transducer.

Reliability estimation about quality assurance method of radiotherapy planning (방사선치료계획 정도관리 방법에 따른 신뢰도 평가)

  • Kim, Jeong-Ho;Kim, Gha-Jung;Yoo, Se-Jong;Kim, Ki-Jin
    • Journal of the Korea Safety Management & Science
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    • v.17 no.1
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    • pp.119-124
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    • 2015
  • According as radiation therapy technique develops, standardization of radiation therapy has been complicated by the plan QA(Quality Assurance). However, plan QA tools are two type, OADT (opposite accumulation dose tool) and 3DADT (3 dimensional accumulation dose tool). OADT is not applied to evaluation of beam path. Therefore tolerance error of beam path will establish measurement value at OADT. Plan is six beam path, five irradiation field at each beam path. And beam path error is 0 degree, 0.2 degree, 0.4 degree, 0.6 degree, 0.6 degree, 0.8 degree. Plan QA accomplishes at OADT, 3DADT. The more path error increases, the more plan QA error increases. Tolerance error of OADT path is 0.357 using tolerance error of conventional plan QA. Henceforth plan QA using OADT will include beam path error. In addition, It will increase reliability through precise and various plan technique.

Experimental Study on Effects of Speed Error Disturbance on Reaction Wheel Control (속도 오차 외란이 반작용 휠 제어에 미치는 영향에 관한 실험적 연구)

  • Kim, Jichul;Lee, Hyungjun;Yoo, Jihoon;Oh, Hwasuk
    • Journal of Aerospace System Engineering
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    • v.10 no.1
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    • pp.95-102
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    • 2016
  • There are many possible disturbance sources on such a spacecraft, but reaction wheel assembly (RWA) which is generally used for spacecraft attitude control is anticipated to be the largest. These effects on degradation of performance of spacecraft such as attitude stability. In reaction wheel, disturbance caused by imbalance and speed error. It is hard to emulate speed error disturbance because it is not coincide with wheel frequency. This paper concentrates on emulating and analyzing the speed error disturbance. Firstly, classify the causes that lead to speed error disturbance which generate RPM fluctuation. Secondly, simulated with disturbance driver module and reaction wheel assembly which are developed by Spacecraft Control Lab. Experimental investigations have been carried out to test the disturbance emulator module as a disturbance generator for RWA. Measurements and test have been conducted on various fault. Frequency analysis of test data show that speed error disturbance effects on wheel settling wheel speed or fluctuation type.

An Analysis of Human Factor and Error for Human Error of the Semiconductor Industry (반도체 산업에서의 인적오류에 대한 인적요인과 과오에 대한 분석)

  • Yun, Yong-Gu;Park, Beom
    • Proceedings of the Safety Management and Science Conference
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    • 2007.04a
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    • pp.113-123
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    • 2007
  • Through so that accident of semiconductor industry deduces unsafe factor of the person center on unsafe behaviour that incident history and questionnaire and I made starting point that extract very important factor. It served as a momentum that make up base that analyzes factors that happen based on factor that extract factor cause classification for the first factor, the second factor and the third factor and presents model of human error. Factor for whole defines factor component for human factor and to cause analysis 1 stage in human factor and step that wish to do access of problem and it do analysis cause of data of 1 step. Also, see significant difference that analyzes interrelation between leading persons about human mistake in semiconductor industry and connect interrelation of mistake by this. Continuously, dictionary road map to human error theoretical background to basis traditional accidental cause model and modern accident cause model and leading persons. I wish to present model and new model in semiconductor industry by backbone that leading persons of existing scholars who present model of existent human error deduce relation. Finally, I wish to deduce backbone of model of pre-suppression about accident leading person of the person center.

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A Broadband Digital Step Attenuator with Low Phase Error and Low Insertion Loss in 0.18-${\mu}m$ SOI CMOS Technology

  • Cho, Moon-Kyu;Kim, Jeong-Geun;Baek, Donghyun
    • ETRI Journal
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    • v.35 no.4
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    • pp.638-643
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    • 2013
  • This paper presents a 5-bit digital step attenuator (DSA) using a commercial 0.18-${\mu}m$ silicon-on-insulator (SOI) process for the wideband phased array antenna. Both low insertion loss and low root mean square (RMS) phase error and amplitude error are achieved employing two attenuation topologies of the switched path attenuator and the switched T-type attenuator. The attenuation coverage of 31 dB with a least significant bit of 1 dB is achieved at DC to 20 GHz. The RMS phase error and amplitude error are less than $2.5^{\circ}$ and less than 0.5 dB, respectively. The measured insertion loss of the reference state is less than 5.5 dB at 10 GHz. The input return loss and output return loss are each less than 12 dB at DC to 20 GHz. The current consumption is nearly zero with a voltage supply of 1.8 V. The chip size is $0.93mm{\times}0.68mm$, including pads. To the best of the authors' knowledge, this is the first demonstration of a low phase error DC-to-20-GHz SOI DSA.

Simulation analysis of type I error and power for F test and rank transformed F test in $2 times 2$ factorial ANOVA ($2 times 2$ 요인 계획법의 F 검정과 순위 F 검정에 따른 제1종 오류와 검정력 분석에 대한 의태 연구)

  • 최영훈
    • The Korean Journal of Applied Statistics
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    • v.8 no.2
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    • pp.87-97
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    • 1995
  • When there is no main effcts or only one main effect in a $2 \times 2$ factorial design, Type I error rates and power for the rank transformed F test (FR test) for interaction are nearly equal to those of the classical F test. However the power of FR test is quite superior under the exponential distribution rather than the of FR test is quite superior under the exponential distribution rather than the normal distribution. Meanwhile when both main effects are in the model, Type I error rates of FR test, compared with those of F test, decrease as the effect size increases and are dependent on the fashion in which main effects are constructed. In addition, the power of FR test increases as the effect size and the sample size increase and is highly dependent on the manner in which main effects are constructed and the type of population distribution.

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Types of Medication Error to Be Used in Korea (의약품 사용 오류)

  • Kim, Hyungtae;Choi, Hye Duck;Kim, Siin;Han, Sola;Lee, Iyn-Hyang;Suh, Hae Sun
    • The Journal of Health Technology Assessment
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    • v.5 no.1
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    • pp.31-41
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    • 2017
  • Objectives: To explore prevalently used types of medication error and the types of medication error which would be appropriate to be used in Korea. Methods: In depth literature review was performed to explore the mostly used types of medication error in the United States, Canada, Europe, Australia, and Japan. We intended to examine experts' view on the suitability of the types of medication error to be used in Korea. The types of medicati0on error were classified by activity criteria, severity criteria, process criteria, and responsible person criteria based on literature reviews. Results: According to the result of literature review, activity criteria was the most commonly used type of medication error. Ten experts in the area of patient-safety and medication error responded and the top two types of medication error which were appropriate and suitable to be used in Korea were severity criteria and activity criteria. Conclusion: Severity criteria and activity criteria could be recommended to be used as the standard types of medication error in Korea although there are other types of criteria such as process criteria and responsible person criteria.

An Empirical Study of the Recovery Experiment in Clinical Chemistry (임상화학검사실에서 회수율 실험의 실증적 연구)

  • Chang, Sang-Wu;Lee, Sang-Gon;Song, Eun-Young;Park, Yong-Won;Park, Byong-Ok
    • Korean Journal of Clinical Laboratory Science
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    • v.38 no.3
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    • pp.184-188
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    • 2006
  • The purpose of the recovery experiment in clinical chemistry is performed to estimate proportional systematic error. We must know all measurements have some error margin in measuring analytical performance. Proportional systematic error is the type of error whose magnitude increases as the concentration of analyte increases. This error is often caused by a substance in the sample matrix that reacts with the sought for analyte and therefore competes with the analytical reagent. Recovery experiments, therefore, are used rather selectively and do not have a high priority when another analytical method is available for comparison purposes. They may still be useful to help understand the nature of any bias revealed in the comparison of kit experiments. Recovery should be expressed as a percentage because the experimental objective is to estimate proportional systematic error, which is a percentage type of error. Good recovery is 100.0%. The difference between 100 and the observed recovery(in percent) is the proportional systematic error. We calculated the amount of analyte added by multiplying the concentration of the analyte added solution by the dilution factor(mL standard)/(mL standard + mL specimen) and took the difference between the sample with addition and the sample with dilution. When making judgments on method performance, the observed that the errors should be compared to the defined allowable error. The average recovery needs to be converted to proportional error(100%/Recovery) and then compared to an analytical quality requirement expressed in percent. The results of recovery experiments were total protein(101.4%), albumin(97.4%), total bilirubin(104%), alkaline phosphatase(89.1%), aspartate aminotransferase(102.8), alanine aminotransferase(103.2), gamma glutamyl transpeptidase(97.6%), creatine kinase(105.4%), lactate dehydrogenase(95.9%), creatinine(103.1%), blood urea nitrogen(102.9%), uric acid(106.4%), total cholesterol(108.5), triglycerides(89.6%), glucose(93%), amylase(109.8), calcium(102.8), inorganic phosphorus(106.3%). We then compared the observed error to the amount of error allowable for the test. There were no items beyond the CLIA criterion for acceptable performance.

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