• Title/Summary/Keyword: Carryover

Search Result 54, Processing Time 0.019 seconds

Evaluation of Carryover Contamination on Autopipetting System (자동분주기의 이월오염 평가)

  • Lee, Hyun-Ju;Min, Gyung-Sun;Shin, Sun-Young;Woo, Jae-Ryong;Lee, Ho-Young
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.13 no.3
    • /
    • pp.189-192
    • /
    • 2009
  • Purpose: Autopipetting system is an efficient automated equipment pipetting patient samples and reagents for rapid and accurate test. However, it can cause carryover between high concentration sample and low concentration sample. We evaluated carryover contamination of TECAN freedom Evo 100 autopipetting system. Materials and Method: We studied carryover contamination of $\alpha$-fetoprotein (AFP) and carcinoembryonic antigen (CEA) test on TECAN freedom Evo 100 autopipetting system. Very low concentration control samples were pipetted for comparison to the contaminated very low concentration samples. Then, The contaminated very low concentration samples were pipetted following the high concentration samples were pipetted alternately. The difference of low concentration samples represents carryover. The target value to decide carryover was 1ppm (parts per million). Results: For AFP, the mean values of the uncontaminated control samples and the contaminated samples were less than 0.6 IU/mL (the l imit of detection (LoD)). Carryover did not occur even though the high concentration sample which value was 650000 IU/mL. For CEA, the values of the low concentration control samples and the contaminated samples were less than 0.2 ng/mL (LoD). Carryover did not occur even though the high concentration sample which value was 65,000 ng/mL. Conclusions: Sample carryover was not found on TECAN freedom Evo 100 autopipetting system for AFP, CEA. However, carryover is a potential problem with automated instruments and robotic pipetting systems. Therefore, Clinical laboratories must periodically verify carryover contamination for the accurate and confidential test results.

  • PDF

The Prevention of Carryover in the Automated System With Fixed Tips (자동 분주기 Fixed Tip의 Carryover 방지를 위한 개선 방안)

  • Hwang, Bo-Ra;Au, Doo-Hee;Bae, Jin-Su;Park, Jong-O;Kim, Ji-Young;Seok, Jae-Dong
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.13 no.3
    • /
    • pp.181-184
    • /
    • 2009
  • Purpose: Automated system that immunoassay examination are used widely. However, sample to sample carryover can cause that the next patient sample is false positive. Materials and Methods: We test HBs Ag, HBs Ab, HBc Ab(IgG) with Automated pipetting system (Tecan). It was placed with very high concentrations followed by saline solution. During this experiment, The fixed tip of Automated system wash With 0.25 moL/L NaOH. The Measurement results of saline solution confirm the occurrence of carryover. Results: Results of saline solution with 0.25 moL/L NaOH cleaning process was measured 100% negative, And results of patient serum with 0.25 moL/L NaOH cleaning process is similar reported results. Conclusion: As Results, 0.25 moL/L NaOH cleaning process was avoid carryover in experiment, And we know results of the hepatitis test did not affected by this solution we recommend 0.25 moL/L NaOH cleaning process as the Prevention of carryover in the automated system with fixed Tips.

  • PDF

ASSESSING POPULATION BIOEQUIVALENCE IN A $2{\times}2$ CROSSOVER DESIGN WITH CARRYOVER EFFECT IN A BAYESIAN PERSPECTIVE

  • Oh Hyun-Sook
    • Journal of the Korean Statistical Society
    • /
    • v.35 no.3
    • /
    • pp.239-250
    • /
    • 2006
  • A $2{\times}2$ crossover design including carryover effect is considered for assessment of population bioequivalence of two drug formulations in a Bayesian framework. In classical analysis, it is complex to deal with the carryover effect since the estimate of the drug effect is biased in the presence of a carryover effect. The proposed method in this article uses uninformative priors and vague proper priors for objectiveness of priors and the posterior probability distribution of the parameters of interest is derived with given priors. The posterior probabilities of the hypotheses for assessing population bioequivalence are evaluated based on a Markov chain Monte Carlo simulation method. An example with real data set is given for illustration.

A Study on the Effects of Advance and Discount Sales of Seasonal Products by Subscription on Logistics Costs (계절상품의 사전 예약판매가 물류비용에 미치는 영향에 관한 연구)

  • Kim, Byeongchan
    • Journal of Korea Society of Digital Industry and Information Management
    • /
    • v.11 no.3
    • /
    • pp.219-230
    • /
    • 2015
  • It is difficult to make plans about the production schedule and volume of seasonal products due to the huge uncertainty in the prediction of their demands, which is why the amounts of carryover seasonal products increase after the peak season. Traditional models fail to meet the important requirements of production and stock plans related to the enhanced efficiency of logistics system due to the reduced value of carryover products by the disposal based on large discounts and deterioration, which poses considerable difficulties with actual problem solving. This study examined the stages of product storage from the specialized factory warehouses during a low season through the stores and the warehouses of local distribution centers during a high season to stock disposal and carryover product warehouses after a high season. The study developed a model for logistics rationalization plans to minimize carryover products by advance selling new products by subscription during a low season in anticipation of high season demands, increasing the accuracy of demands prediction, and making stable production plans, as well as demonstrated its excellence through numerical analysis.

Development of Direct Measurement Device for Alveolar Breath Carbon Monoxide

  • Jo, Wan-Kuen;Oh, Jee-Won
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.18 no.E4
    • /
    • pp.181-190
    • /
    • 2002
  • A novel portable device for the direct measurement of alveolar breath carbon monoxide (CO) was developed. The major components of the device include a mouthpiece, non-rebreathing two-way valve, Teflon tube, and CO dosimeter. An alveolar CO measurement can be completed within 1.5 min when using the proposed device and measurement protocol. Measurements could be read to the nearest 0.1 ppm. Humidity did not influence the CO measurements taken by the CO dosimeter, plus there were no problems associated with the recovery and carryover of CO through the device. The criterion for significance in statistical analyses was p< 0.05. The average recovery was 103 and 99% for recovery and carryover experiments, respectively. Test results using the proposed alveolar CO measurement system reflected a good reproducibility. This reproducibility was also supported by the finding that the relative standard deviations (RSDs) of the data sets were less than 7% for the loss experiment and less than 8% for the carryover experiment. Consequently, it would appear that the proposed device can be effectively applied to measure CO levels found in breath, thereby overcoming several disadvantages associated with the conventional bag and adsorbent tube sampling methods.

An Experimental Study on Air Leakage and Heat Transfer Characteristics of a Rotary-type Heat Recovery Ventilator

  • Han, Hwa-Taik;Kim, Min-Kyu
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • v.13 no.2
    • /
    • pp.83-88
    • /
    • 2005
  • This study investigates the air leakage and heat transfer characteristics of a commercially available rotary-type air-to-air heat exchanger with a fiber polyester matrix. Crossover leakage between the exhaust and supply air is measured using a tracer gas method for various ventilation rates and rotational speeds of the wheel. A correlation equation for the leakage is obtained by summing up pressure leakage and carryover leakage. The pressure leakage is observed to be a function of ventilation rate only, and the carryover leakage is found to be a linear function of wheel speed. The real efficiency of the heat exchanger can be obtained from its apparent efficiency by taking into account the leakage ratio. The heat recovery efficiency decreases, as the ventilation rate increases. As the wheel speed increases, however, the efficiency increases initially but reaches a constant value for the speeds over 10rpm.

An Experimental Study on Air Leakage and Heat Transfer Characteristics of a Rotary-type Heat Recovery Ventilator (회전식 폐열회수 환기유닛의 공기누설 및 전열특성에 관한 실험적 연구)

  • Han Hwataik;Kim Min-Kyu
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.16 no.12
    • /
    • pp.1197-1203
    • /
    • 2004
  • This study investigates the air leakage and heat transfer characteristics of a rotary-type air-to-air heat exchanger with a fiber polyester matrix. The leakage airflow rate is measured using a tracer gas method for various ventilation rates and rotational speeds of the matrix wheel. A correlation equation for air leakage is obtained by combining the pressure leakage and the carryover leakage. The pressure leakage is observed to be a function of ventilation airflow rate only, and the carryover leakage is found to be a linear function of rotational speed. The real efficiency of the heat exchanger can be obtained from its apparent efficiencies by taking into account the air leakage ratio. As the ventilation rate increases, the heat recovery efficiency decreases. As the rotational speed of the matrix increases, the efficiency increases initially but reaches a constant value for the rotational speeds over 10 rpm.

Re-Considering Aggregated Data Bias by Extending "Koyck Model" of Advertising Effect (광고 효과 확장 코익 모델을 이용한 Aggregated data bias의 재조명)

  • Song, Tea-Ho;Yuan, Xina;Kim, Ji-Yoon
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.34 no.2
    • /
    • pp.91-100
    • /
    • 2009
  • "How does advertising affect sales?" is the fundamental issue of modern advertising research. There is an interesting issue for estimating carryover effects of advertising on sales, and the aggregated data biases exist in the duration of advertising effect. This research suggests an extended model of Koyck Model which is employed for micro-data (Koyck 1954) to estimate aggregated advertising data, and empirically shows the aggregated data bias. Our developed model with the aggregated level of actual advertising data is more appropriate than the basic Koyck model for micro-data. The result figures out that it is important to consider the disaggregated data level in the analysis of dynamic effects of adverting such as carryover effects.

A Bayes Test for Equality of Intra-Subject Variabilities in 2$\times$2 Crossover Design

  • Oh, Hyun-Sook
    • Communications for Statistical Applications and Methods
    • /
    • v.7 no.2
    • /
    • pp.541-548
    • /
    • 2000
  • Various statistical methods for assessment of equivalence in average bioavailabilities have been developed under the assumption that the intra-subject variabilities for the test and reference formulations are the same. Without the assumption, assessing the equivalence in average bioavailabilites does not imply that the two formulations are therapeutically equivalent and exchangeable. The most commonly used test procedure for equality of variabilites in 2$\times$2 crossover experiment is the so called Pitman-Morgan's adjusted F test based on the model without carryover effects (Chow and Liu(1992)). In this paper, a Bayesian method based on the Intrinsic Bayes Factor is proposed, which can be applied to the model with carryover effects.

  • PDF

Context-sensitive lingual gestures in the Korean tap /r/

  • Kim, Dae-Won
    • Speech Sciences
    • /
    • v.7 no.3
    • /
    • pp.11-19
    • /
    • 2000
  • The present electropalatographic study reports the production of the allophones. i.e., [l] and [r], of Korean tap /r/ and their coarticulatory characteristics in /$C{\'{a}}r#g$/ and /$C{\'{a}}r#i$/ sequences. The finding that tap /r/ involves a complete oral closure with less lingual contact, i.e., apico-frontalveolar coupling. than lateralized /r/ which involves apico-bladealveolar coupling and tongue dorsum lowering for adequate airflow through either side and/or both of the tongue body suggests that the two allophones of the tap /r/ have different lingual gestures. Moreover. in comparison with the tap. the lateral exerts longer lingual contacts. The mean ratio between them is 3.7. In the sequences /Car#g/. the two adjacent antagonistic segments (i.e., /r/ and /g/) show mutual coarticulation effects taking on features of adjacent segment. but either of them is precisely constrained without blocking the formation of involved major lingual gestures for the other segment. In sequences /Car#i/ occurs anticipatory V-to-C coarticulation but not vocalic carryover effects. In both sequences. the allophones reveal insignificant wordinitial consonantal carryover coarticulatory effects and insignificant speaker-specific lingual contacts.

  • PDF