• Title/Summary/Keyword: Uncertainty evaluation

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Validation and Uncertainty Evaluation of an Optimized Analytical Method Using HPLC Applied to Canthaxanthin, a Food Colorant (식품 색소 Canthaxanthin의 HPLC 최적 분석법 확인 및 타당성과 측정불확도 평가)

  • Suh, Hee-Jae;Kim, Kyung-Su;Hong, Mi-Na;Lee, Chan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.3
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    • pp.342-351
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    • 2016
  • This study was carried out to develop an optimized analytical method using high-performance liquid chromatography (HPLC) applied to canthaxanthin, which is not yet designated as a food colorant in Korea, as well as to perform validation and uncertainty evaluation of this method. Official methods of AOAC, UK, and Japan with HPLC-UV detection were evaluated for the analysis of canthaxanthin by comparison of linearity, resolution, selectivity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision, recovery, inter-laboratory tests, and uncertainty measurement. The calibration curves showed high linearity with an $R_2$ value of over 0.999 for canthaxanthin standard solutions in all three official methods. The official method of Japan exhibited the best results in terms of resolution and selectivity, including the lowest LOD and LOQ. The average coefficients of variation were calculated as less than five of three institutes with a precision value less than 1, accuracy near 100%, and recovery ratio between $100{\pm}10%$. The expanded uncertainty for canthaxanthin was estimated to be $39.5{\pm}5.29mg/kg$ (95% confidence level, k=2), and the uncertainty of measurement was 13.4%. In this study, official methods of canthaxanthin were compared and the validities verified. The results will be further applied to establish an authorized analytical method for canthaxanthin in Korea.

A Study on Feasibility Evaluation for Prognosis Systems based on an Empirical Model in Nuclear Power Plants

  • Lee, Soo Ill
    • International Journal of Safety
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    • v.11 no.1
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    • pp.26-32
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    • 2012
  • This paper introduces a feasibility evaluation method for prognosis systems based on an empirical model in nuclear power plants. By exploiting the dynamical signature characterized by abnormal phenomena, the prognosis technique can be applied to detect the plant abnormal states prior to an unexpected plant trip. Early $operator^{\circ}{\emptyset}s$ awareness can extend available time for operation action; therefore, unexpected plant trip and time-consuming maintenance can be reduced. For the practical application in nuclear power plant, it is important not only to enhance the advantages of prognosis systems, but also to quantify the negative impact in prognosis, e.g., uncertainty. In order to apply these prognosis systems to real nuclear power plants, it is necessary to conduct a feasibility evaluation; the evaluation consists of 4 steps (: the development of an evaluation method, the development of selection criteria for the abnormal state, acquisition and signal processing, and an evaluation experiment). In this paper, we introduce the feasibility evaluation method and propose further study points for applying prognosis systems from KHNP's experiences in testing some prognosis technologies available in the market.

Uncertainty evaluation of dioxin analysis in blood samples (혈액 시료 중 다이옥신의 농도 분석 결과에 대한 불확도 평가)

  • Mun, Su-Jung;Kim, Byung-Hoon;Woo, Jin-Chun;Chang, Yoon-Seok
    • Analytical Science and Technology
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    • v.16 no.6
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    • pp.475-482
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    • 2003
  • Uncertainty of final measurement results considering main uncertainty sources being in dioxin analysis of a blood sample was estimated. 'The Guide to the Expression of Uncertainty in Measurement' was suggested for accomplishment of this study. After uncertainties for the 11 compounds detected in this experiment of the 17 target compounds of dioxin and furan were calculated considering the uncertainty sources of each step, uncertainty for the total dioxin concentration was estimated by combining these values. The concentration of dioxin in blood sample was expressed as $0.0746{\pm}0.0074pg$ I-TEQ/g weight or $20.68{\pm}2.04pg$ I-TEQ/g lipid, including the uncertainty values obtained in this way. The former expression indicates the conversion concentration into the sample weight and the latter one indicates the conversion concentration into the lipid weight. The quality of measured analytical results could be assured quantitatively by estimating uncertainty of measurement results and showing the range of measurand.

A preliminary Study on Process Improvement for BIM based Condensation Performance Evaluation of Apartment Housings (BIM기반 공동주택 결로 성능평가를 위한 프로세스 개선방안에 관한 기초연구)

  • Hong, Jooyoung;Kim, Daegil;Lee, Myungdo;Kim, Daewon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.245-246
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    • 2016
  • The condensation performance evaluation is required for improved living environment of apartment housings. In the current condensation performance evaluation process, high demand of manual works and repetitive process cause unexpected risks due to uncertainty and inefficiency by applying 2D CAD drawings in simulation tool. Furthermore, the evaluation requires taking in action responding to the expanding use of BIM. In this study, the analysis of current evaluation process and required functions for the process improvement based on BIM modeling were deducted from interviews with experts. It is expected that the results of this study can be employed to develop of process automation module for condensation simulation evaluation.

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The Effect of Value-added Promotion and Retailer Uncertainty on Customers' Perceived Value of the Product (부가가치 제공 유형별 판매촉진과 유통업체 불확실성이 제품 가치 평가에 미치는 영향 - 사은품(Freebie) 제공 판매촉진을 중심으로 -)

  • Kim, Hyang-Mi;Lee, So-Young;Kim, Jae-Wook
    • Journal of Distribution Research
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    • v.16 no.1
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    • pp.117-140
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    • 2011
  • The sales promotion strategy can be classified into two categories: cost-down and value-added promotions. Although many studies have been performed on sales promotion in the past, little attention has been given on cost-down promotion, and in particular on its strategy. Also there has been a renewed interest on value-added promotion strategy as means of attracting more customers and delivering value by providing a greater benefit. This study examines the effect of value-added promotion on the evaluation of promotional products. The topic is important because the value-added promotions are not always perceived as a benefit by consumers and they depend on the situational factors. We postulate three hypotheses on the basis of related literature. We conduct two studies: one employing experiment (study 1) and the other, quasi-experiment (study 2) to investigate the effect of two situational factors, namely the promotional package type and retailer uncertainty on the valuation of promotional products. Study 1 employs 2 promotional package types (bundled with freebie type vs. one-plus-one type) by 3 evaluation targets (overall package, a focal product and freebie) in experimental design. Also it is found that consumers devaluate the promotional product when the level of retailer uncertainty is high (t=-4.70, p=.000) as shown in Table 2. As depicted in Figure 2, the interaction effect of retailer uncertainty and package types on the evaluation of promotional product as a whole does not appear to be significant. However, when the level of retailer uncertainty is high, the focal product suffers from lower valuation if it is included in a bundle with freebie type package. The purpose of Study 2 is to cross-check the results of Study 1. The results of Study 2 also show that the consumers devaluate the promotional products as a whole when the level of retailer uncertainty is high. Furthermore, Study2 examines the consumers' willingness to purchase. The willingness to purchase of 2 different consumer groups divided by their reservation prices before and after exposure to a promotional stimuli shows no significant differences(t=1.911, p=.057). The results suggest that the consumers' reservation prices before the exposure to the promotion can be a reference prices of their's. But after the promotional events, the promotional price would become their reference prices. Furthermore, when the level of retailer uncertainty is high, consumers devaluate the promotional product as a whole. Because the promotional offerings activate the persuasion knowledge of consumers and make them incorporate negative inference about the firm's motives into their valuation and consequently, consumers tend to hesitate to purchase.

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MEASURING THE INFLUENCE OF TASK COMPLEXITY ON HUMAN ERROR PROBABILITY: AN EMPIRICAL EVALUATION

  • Podofillini, Luca;Park, Jinkyun;Dang, Vinh N.
    • Nuclear Engineering and Technology
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    • v.45 no.2
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    • pp.151-164
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    • 2013
  • A key input for the assessment of Human Error Probabilities (HEPs) with Human Reliability Analysis (HRA) methods is the evaluation of the factors influencing the human performance (often referred to as Performance Shaping Factors, PSFs). In general, the definition of these factors and the supporting guidance are such that their evaluation involves significant subjectivity. This affects the repeatability of HRA results as well as the collection of HRA data for model construction and verification. In this context, the present paper considers the TAsk COMplexity (TACOM) measure, developed by one of the authors to quantify the complexity of procedure-guided tasks (by the operating crew of nuclear power plants in emergency situations), and evaluates its use to represent (objectively and quantitatively) task complexity issues relevant to HRA methods. In particular, TACOM scores are calculated for five Human Failure Events (HFEs) for which empirical evidence on the HEPs (albeit with large uncertainty) and influencing factors are available - from the International HRA Empirical Study. The empirical evaluation has shown promising results. The TACOM score increases as the empirical HEP of the selected HFEs increases. Except for one case, TACOM scores are well distinguished if related to different difficulty categories (e.g., "easy" vs. "somewhat difficult"), while values corresponding to tasks within the same category are very close. Despite some important limitations related to the small number of HFEs investigated and the large uncertainty in their HEPs, this paper presents one of few attempts to empirically study the effect of a performance shaping factor on the human error probability. This type of study is important to enhance the empirical basis of HRA methods, to make sure that 1) the definitions of the PSFs cover the influences important for HRA (i.e., influencing the error probability), and 2) the quantitative relationships among PSFs and error probability are adequately represented.

A Moderating Role of Personal Need for Structure on the Effects of Process versus Outcome Simulations on the Evaluation of Really New Products

  • Kim, Jun San;Hahn, Minhi;Yoon, Yeosun
    • Asia Marketing Journal
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    • v.14 no.4
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    • pp.77-94
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    • 2013
  • Really new products (RNPs) provide novel benefits yet many consumers are reluctant to accept these highly innovative new products. Previous literature has shown that mental simulation is an effective method for enhancing the evaluation of RNPs. However, Castano et al. (2008) and Zhao, Hoeffler, and Zauberman (2011) demonstrate conflicting results as to which type of mental simulation (i.e., process versus outcome) is more effective for the enhancement of RNP evaluation. The authors try to reconcile these results by incorporating a moderating variable which is personal need for structure (PNS). PNS is an individual difference variable that taps the differences in people's propensity to cognitively structure and simplify their environment (Neuberg and Newsom 1993). From the analysis of the previous two works, the authors point out that consumers' susceptibility to uncertainty may contribute to the different results, and suggest that this susceptibility is dependent on consumers' PNS. To test the hypotheses established, an experiment was conducted. Waterless washing machine was presented as a RNP and PNS was measured by using the 12-item PNS Scale (Thompson et al. 2001). The results of the study show that for high-PNS consumers, process simulation is more effective than outcome simulation for enhancing the evaluation of a RNP, whereas for low-PNS consumers, outcome simulation is more effective than process simulation. This research contributes to the mental simulation and new product literature by suggesting and verifying that PNS moderates the effects of process versus outcome simulations for enhancing the evaluation of RNPs. This research provides important managerial implications for marketing managers of RNPs, indicating that they should take account of the target consumers' PNS in planning marketing communications. Specifically, when targeting high-PNS consumers, marketing communications that encourage process simulation may be more effective than those that encourage outcome simulation. In contrast, when targeting low-PNS consumers, marketing communications that encourage outcome simulation may be more effective than those that encourage process simulation.

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Measurements of Two-dimensional Gratings Using a Metrological Atomic Force Microscope and Uncertainty Evaluation (길이 표준 소급성을 갖는 원자간력 현미경을 이용한 2차원 격자 시편 측정과 불확도 평가)

  • Kim, Jong-Ahn;Kim, Jae-Wan;Kang, Chu-Shik;Eom, Tae-Bong
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.9
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    • pp.68-75
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    • 2007
  • The pitch and orthogonality of two-dimensional (2D) gratings have been measured by using a metrological atomic force microscope (MAFM) and measurement uncertainty has been analyzed. Gratings are typical standard artifacts for the calibration of precision microscopes. Since the magnification and orthogonality in two perpendicular axes of microscopes can be calibrated simultaneously using 2D gratings, it is important to certify the pitch and orthogonality of 2D gratings accurately for nano-metrology using precision microscopes. In the measurement of 2D gratings, the MAFM can be used effectively for its nanometric resolution and uncertainty, but a new measurement scheme was required to overcome some limitations of current MAFM such as nonnegligible thermal drift and slow scan speed. Two kinds of 2D gratings, each with the nominal pitch of 300 nm and 1000 nm, were measured using line scans for the pitch measurement of each direction. The expanded uncertainties (k = 2) of measured pitch values were less than 0.2 nm and 0.4 nm for each specimen, and those of measured orthogonality were less than 0.09 degree and 0.05 degree respectively. The experimental results measured using the MAFM and optical diffractometer were coincident with each other within the expanded uncertainty of the MAFM. As a future work, we also proposed another scheme for the measurements of 2D gratings to increase the accuracy of calculated peak positions.

UKF Localization of a Mobile Robot in an Indoor Environment and Performance Evaluation (실내 이동로봇의 UKF 위치 추정 및 성능 평가)

  • Han, Jun Hee;Ko, Nak Yong
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.4
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    • pp.361-368
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    • 2015
  • This paper reports an unscented Kalman filter approach for localization of a mobile robot in an indoor environment. The method proposes a new model of measurement uncertainty which adjusts the error covariance according to the measured distance. The method also uses non-zero off diagonal values in error covariance matrices of motion uncertainty and measurement uncertainty. The method is tested through experiments in an indoor environment of 100*40 m working space using a differential drive robot which uses Laser range finder as an exteroceptive sensor. The results compare the localization performance of the proposed method with the conventional method which doesn't use adaptive measurement uncertainty model. Also, the experiment verifies the improvement due to non-zero off diagonal elements in covariance matrices. This paper contributes to implementing and evaluating a practical UKF approach for mobile robot localization.

Uncertainty Assessment of a Towed Underwater Stereoscopic PIV System (예인수조용 스테레오스코픽 입자영상유속계 시스템의 불확실성 해석)

  • Seo, Jeonghwa;Seol, Dong Myung;Han, Bum Woo;Yoo, Geuksang;Lim, Tae Gu;Park, Seong Taek;Rhee, Shin Hyung
    • Journal of the Society of Naval Architects of Korea
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    • v.51 no.4
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    • pp.311-320
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    • 2014
  • Test uncertainty of a towed underwater Stereoscopic Particle Image Velocimetry (SPIV) system was assessed in a towing tank. To estimate the systematic error and random error of mean velocity and turbulence properties measurement, velocity field of uniform flow was measured. Total uncertainty of the axial component of mean velocity was 1.45% of the uniform flow speed and total uncertainty of turbulence properties was 3.03%. Besides, variation of particle displacement was applied to identify the change of error distribution. In results for variation of particle displacement, the error rapidly increases with particle movement under one pixel. In addition, a nominal wake of a model ship was measured and compared with existing experimental data by five-hole Pitot tubes, Pitot-static tube, and hot wire anemometer. For mean velocity, small local vortex was identified with high spatial resolution of SPIV, but has serious disagreement in local maxima of turbulence properties due to limited sampling rate.