• Title/Summary/Keyword: reliability sensitivity

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Reliability of Stool Antigen Tests: Investigation of the Diagnostic Value of a New Immunochromatographic Helicobacter pylori Approach in Dyspeptic Patients

  • Korkmaz, Huseyin;Findik, Duygu;Ugurluoglu, Ceyha;Terzi, Yuksel
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.2
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    • pp.657-660
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    • 2015
  • Background: A diagnosis of H. pylori infection can be made by invasive or non-invasive methods. Several noninvasive diagnostic tests based on the detection of H. pylori stool antigen (HpSA) have been developed. The Genx H. pylori stool antigen card test is a new rapid, non-invasive test that is based on monoclonal immunochromatographic assay. The aim of this study was to determine its sensitivity, specificity, and diagnostic accuracy for diagnosing H. pylori infection in adult patients. Materials and Methods: A total of 162 patients were included in the study. A gastric biopsy was collected for histopathology and rapid urease testing. Stool specimens for HpSA testing were also collected. Patients were considered H. pylori positive if two invasive tests (histological and rapid urease tests) were positive. Results: Using the reference test, 50.6% of the samples were positive for H. pylori infection. The Genx H. pylori antigen test was positive in 19.7% of patients. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the Genx H. pylori antigen test were 51.6%, 96.0%, 88.8%, 76.1%, and 79.0%, respectively. Conclusions: The Genx H. pylori stool antigen card test is a new non-invasive method that is fast and simple to perform but provides less reliable results.

Clinical Impact and Reliability of Carbonic Anhydrase XII in the Differentiation of Malignant and Tuberculous Pleural Effusions

  • Liu, Yun-Long;Jing, Li-Ling;Guo, Qi-Sen
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.351-354
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    • 2013
  • Objective: To assess the practical utility of pleural fluid carbonic anhydrase XII (CAXII) quantification for differential diagnosis of effusions. Materials and Methods: Fluid was collected prospectively from fifty patients presenting with lymphocytic pleural effusions for investigation and CAXII was quantified by ELISA. Results: Pleural fluid CAXII concentrations were significantly higher in lung cancer patients (n=30) than in tuberculous controls (n=20). The sensitivity and specificity of this biomarker were 60%and 75%, respectively. CAXII measurement was not inferior to cytological examination in the diagnosis and exclusion of pleural effusions from lung cancer patitents (sensitivity 60% vs. 57%; specificity 75% vs. 100%; positive predictive value 77%; negative predictive value 54%). In patients with negative cytology, it offered a sensitivity of 54%. Conclusions: Pleural fluid CAXII is elevated in pleural effusions from lung cancer patients. Measurement of CAXII may be used in the future as a valuable adjunct to cytology in the diagnostic assessment of patients with pleural effusions related to lung cancer, especially when cytological examination is inconclusive.

Reliability and Accuracy of Infrared Temperature: A Systematic Review (적외선 체온의 진단 정확도 평가 연구: 체계적 문헌고찰)

  • Park, Seong-Hi
    • Korean Journal of Adult Nursing
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    • v.26 no.6
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    • pp.668-680
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    • 2014
  • Purpose: The aim of this study was to investigate the accuracy of infrared temperature measurements compared to axillary temperature in order to detect fever in patients. Methods: Studies published between 1946 and 2012 from periodicals indexed in Ovid Medline, Embase, CINAHL, Cochrane, KoreaMed, NDSL, KERIS and other databases were selected using the following key words: "infrared thermometer". QUADAS-II was utilized to assess the internal validity of the diagnostic studies. Selected studies were analyzed through a meta-analysis using MetaDisc 1.4. Results: Twenty-one diagnostic studies with high methodological quality were included representing 3,623 subjects in total. Results of the meta-analysis showed that the pooled sensitivity, specificity, and area under the curve (AUC) of infrared tympanic thermometers were 0.73 (95% CI 0.70~0.75), 0.92 (95% CI 0.91~0.92), and 0.90, respectively. For axillary temperature readings, the pooled sensitivity was 0.67 (95% CI 0.62~0.73), the pooled specificity was 0.87 (95% CI 0.85~0.90), and the AUC was 0.80. Conclusion: Infrared tympanic temperature can predict axillary temperature in normothermic and in febrile patients with an acceptable level of diagnostic accuracy. However, further research is necessary to substantiate this finding in patients with hyperthermia.

Nano-level High Sensitivity Measurement Using Microscopic Moiré Interferometry (마이크로 무아레 간섭계를 이용한 초정밀 변형 측정)

  • Joo, Jin-Won;Kim, Han-Jun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.2
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    • pp.186-193
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    • 2008
  • [ $Moir{\acute{e}}$ ] interferometry is an optical method, providing whole field contour maps of in-plane displacements with high resolution. The demand for enhanced sensitivity in displacement measurements leads to the technique of microscopic $moir{\acute{e}}$ interferometry. The method is an extension of the $moir{\acute{e}}$ interferometry, and employs an optical microscope for the required spatial resolution. In this paper, the sensitivity of $moir{\acute{e}}$ interferometry is enhanced by an order of magnitude using an immersion interferometry and the optical/digital fringe multiplication(O/DFM) method. In fringe patterns, the contour interval represents the displacement of 52 nm per fringe order. In order to estimate the reliability and the applicability of the optical system implemented, the measurements of rigid body displacements of grating mold and the coefficient of thermal expansion(CTE) for an aluminium block are performed. The system developed is applied to the measurement of thermal deformation in a flip chip plastic ball grid array package.

A Study on the estimation of an equivalent system of a local vibration system of a huge structure and the Optimum Structural Modification Method (거대 구조물의 국부진동계의 등가계 산출과 이를 이용한 최적구조변경법)

  • 박석주;황문주;오창근;김성우
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.04a
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    • pp.120-127
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    • 1998
  • It is very difficult to execute the vibration analysis of a huge strucutre, which takes up much time and expense. In this paper we intend to make the equivalent system of a local vibration system of a huge structure with a view to improving the dynamic characteristics and reducing time and expense. First of all, upper deck structure model is maded. And we perform the vibration analysis by the Substructure Synthesis Method and execute the exciting test for the upper deck structure model, and observe the coincidences of two results to confirm the reliability of the analyzing tools used. To make the equivalent system, we give boundary condition to sub-structure that want to be modified and execute the Sensitivity Analysis Method and the Optimum Structural Modification Method. And we execute the structural modification of the equivalent system.. The following can be found from this study. 1. The analytical results are generally coincident with each other. 2. The equivalent system of the superstructure model can be easily obtained using the sensitivity analysis metho and the optimum structural modification method. 3. The structural modification using the equivalent system can be obtained good results above 90% of object value.

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SENSITIVITY OF THE KEUM RIVER BASIN TO CLIMATE CHANGE

  • Kim, Young-Oh;Seo, Yong-Won;Lee, Seung-Hyun;Lee, Dong-Ryul
    • Water Engineering Research
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    • v.1 no.4
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    • pp.267-277
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    • 2000
  • This study reports an examination of the sensitivity of water resources in the Keum River basin to climate change. Assuming a doubling in $CO_2$ concentrations, a cooperative study provided four climate change scenarios for this study, which have been translated into temperature and precipitation scenarios on a basin scale. The study utilized these temperature and precipitation data for each climate change scenario as inputs to the NWS-PC model to generate the corresponding streamflow scenario over the Keum River basin. A reservoir simulation model for the Dae-Chung Dam in the Keum River basin has been developed with an object-oriented simulation environment, STELLA. For each streamflow scenario, the performance of the reservoir was assessed in terms of reliability, resiliency, and vulnerability. Although the simulation results are heavily dependent on the choice of the climate change scenarios, the following conclusions can be clearly concluded: (1) the future streamflow over the Dae-Chung Dam tends to decease during the dry period, which seriously increases competitive water use issues and (2) flood control issues predominate under the $2CO_2$-High case.

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Study on Aging Characteristics of Exploding Foil Initiator (고전압 기폭관의 노화 특성 연구)

  • Kim, Dong-seong;Jang, Seung-gyo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.8
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    • pp.581-588
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    • 2020
  • The aging characteristics of exploding foil initiator (EFI) are studied. In order to observe the aging characteristics, the main components of the exploding foil initiator were classified and the failure mechanism was defined. The aging characteristics were defined in terms of power and sensitivity, and the accelerated aging test plan was established based on the activation energy calculated by HFC (Heat Flow Calorimetry) and Arrhenius theory. The performance variation was observed using the sensitivity test (Neyer test) and power test (Dent test) for the aged samples. The aging characteristic was observed on the mean exploding point of the sensitivity test, but long-enough life span was predicted considering the related specification.

A Study on the Weight Minimization of an Automobile Engine Block by the Optimum Structural Modification (최적구조변경법에 의한 자동차 엔진 블록의 중량최소화에 관한 연구)

  • 김영군;박석주;김성우
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.10a
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    • pp.326-332
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    • 1997
  • Recently to develop an automobile with better prosperities, many researches and investments have been executed. In this paper we intend to improve the automobile properties by reducing the weights of the engine without changing the dynamic characteristics. At first we perform the vibration analysis by the Substructure Synthesis Method and execute the exciting test for the engine model, and observe the coincidences of two results to confirm the reliability of the analyzing tools used. The weight minimization is performed by the Sensitivities of the Natural frequencies of the engine block. To decrease the engine weight ideally, the parts of the sensitivity zero are to be cut mainly, and the changing quantity of natural frequency by the cut is to be recovered by the structural modification for the parts with the good sensitivity. But, as actually the mathematical solution for the homogeneous problem(i.e. 0 object function) do not exist, we hereby redesign the block with much thinner thickness and recover the natural frequencies and natural modes to original structure's by the sensitivity analysis. And the Frequency Response Functions(FRF) are to be observed for the interesting points. In this analysis, the original thickness of the engine model has 8 mm of thickness, and the thickness redesigned is 5 mm and 6 mm. And we are to try to recover the 1, 2, 4, and 5 lower natural frequencies interested.

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The Effects of Consumer Innovation, Price Sensitivity, Conformity, and Consumer Values on Consumer Attitudes and Intentions to Participate in the Crowdfunding of Fashion Products (소비자 혁신성, 가격민감도, 동조 성향, 소비자 가치가 패션제품의 크라우드펀딩에 대한 소비자 태도 및 펀딩참여의도에 미치는 영향)

  • Jae Hee Kim;Nalae Kim;Yoon-Jung Lee
    • Human Ecology Research
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    • v.61 no.3
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    • pp.281-295
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    • 2023
  • This study examined consumer attitudes and intentions to participate in reward-based crowdfunding projects for fashion products. We focused on consumer innovation, price sensitivity, conformity, and consumer values as factors that might influence such attitudes and intentions. A survey was conducted with 228 individuals aged 18 years and older who are aware of or have had experience using crowdfunding. Respondents were asked to answer questions based on the example of actual fashion crowdfunding projects. To analyze the data, reliability tests, the generation of descriptive statistics, factor analysis, and multiple regression were performed using SPSS 25.0. The results revealed that consumer innovativeness, non-conforming tendency, and emotional, quality, social, and ethnical consumer values had a significant influence on attitudes, which in turn affected intentions to participate in crowdfunding. Consumer innovativeness, price sensitivity, emotional value, and social value also had a direct influence on intentions to participate. In addition to its academic contribution, this study has important marketing implications for project initiators striving to identify and understand consumers who are willing to participate in reward-based crowdfunding for fashion products.

Impact Performance Optimization of Auto-Sensing Breaker using Multi-objective Function (다목적함수를 이용한 지능형 브레이커의 타격성능 최적화)

  • Lee, Dae-Hee;Noh, Dae-Kyung;Park, Sung-Su;Lee, Geun-Ho;Kang, Young-Ky;Cho, Jae-Sang;Jang, Joo-Sup
    • Journal of the Korea Society for Simulation
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    • v.26 no.4
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    • pp.11-21
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    • 2017
  • This paper discusses the design parameter sensitivity analysis and multi-objective function optimization for improving the impact performance of an auto-sensing breaker based on the analytical model of the same, which secured reliability in a previous research. The study aims to improve both impact power and stability by complementing the existing research that only improved the impact power. The study sequence is as follows: first, the analysis scenarios for the accurate sensitivity analysis and optimization are set up. Second, the sensitivity of the design parameter of the auto-sensing breaker is analyzed, and the variables with high sensitivity are extracted. Third, the extracted variables are used to optimize the multi-objective functions, and the optimized performance is compared with the initial performance to see how the impact performance on the existing auto-sensing breaker has improved. This study is based on domestic technology, and will allow the development of products with a better blowing performance than their existing overseas counterparts.