• IE interfaces
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• v.24 no.2
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• pp.119-127
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• 2011

Most companies have been increasing temporary work projects to maximize the usage of their resources. They also have been developing the effective techniques for analyzing and managing the state of the projects. In order to monitor the state of a project in real-time and predict the project's future state more accurately, this paper suggests the Bayesian Network (BN) as a tool for discovering the causes of project risk and presenting the failure probability of the project. The proposed BN modeling method with consideration of the Earned Value Management (EVM) method shows how to induce the predictive and conditional probability of the risk occurrence in the future. The advantages of the suggested model are (1) that the cause of a project risk can be easily figured out via the BN, (2) that the future value of the project can be sufficiently increased by updating relevant components of the project, and (3) that more credible prediction can be made in the similar and future situation by using the data obtained in current analysis. A numerical example is also given.

• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.143-149
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• 2015

In this paper, we proposed a novel method for automatic detection for snoring and heart beat using a single piezoelectric sensor. For this study multi-rate signal processing technique was applied to detect snoring and heart beat from the single source signal. The sound event duration and intensity features were used to snore detection and heart beat was found by autocorrelation. The performance of the proposed method was evaluated on clinical database, which is the nocturnal piezoelectric snoring data of 30 patients that suffered obstructive sleep apnea. The method achieved sensitivity of 88.6%, specificity of 96.1% with accuracy of 95.6% for snoring and sensitivity of 94.1% and positive predictive value of 87.6% for heart beat, respectively. These results suggest that the proposed method can be a useful tool in sleep monitoring and sleep disordered breathing diagnosis.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.636-640
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• 2011

Film cooling technique has been applied to effectively reduce thermal load on liquid rocket combustion chambers by direct injection of a portion of propellant, which flows through the regeneratively cooling channels, into the chamber wall. This study developed a comprehensive model to quantitatively predict the effects of kerosene film cooling on propulsive performance and wall cooling at supercritical pressure conditions, and assessed the predictive capability against hot-firing tests of an actual combustor. The present model is expected to be utilized as a design and analysis tool to meet the conflicting requirements in terms of performance, cooling, pressure loss and weight.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.275-288
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• 2010

Ecological modeling faces some unique problems in dealing with complex environment-organism relationships, making it one of the toughest domains that might be encountered by a modeler. Newer technologies and ecosystem modeling paradigms have recently been proposed, all as part of a broader effort to reduce the uncertainty in models arising from qualitative and quantitative imperfections in the ecological data. In this paper, evolutionary computation modeling approaches are introduced and proposed as useful modeling tools for ecosystems. The results of our case study support the applicability of an algal predictive model constructed via genetic programming. In conclusion, we propose that evolutionary computation may constitute a powerful tool for the modeling of highly complex objects, such as river ecosystems.

• Journal of Genetic Medicine
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• v.12 no.2
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• pp.72-78
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• 2015

Recently, noninvasive prenatal test (NIPT) has been adopted as a primary screening tool for fetal chromosomal aneuploidy. The principle of NIPT lies in isolating the fetal fraction of cell-free DNA in maternal plasma and analyzing it with bioinformatic tools to measure the amount of gene from the target chromosome, such as chromosomes 21, 18, and 13. NIPT will contribute to decreasing the need for unnecessary invasive procedures, including amniocentesis and chorionic villi sampling, for confirming fetal aneuploidy because of its higher positive predictive value than that of the conventional prenatal screening method. However, its greater cost than that of the current antenatal screening protocol may be an obstacle to the adoption of this innovative technique in clinical practice. Digital polymerase chain reaction (dPCR) is a novel approach for detecting and quantifying nucleic acid. dPCR provides real-time diagnostic advantages with higher sensitivity, accuracy, and absolute quantification than conventional quantitative PCR. Since the groundbreaking discovery that fetal cell-free nucleic acid exists in maternal plasma was reported, dPCR has been used for the quantification of fetal DNA and for screening for fetal aneuploidy. It has been suggested that dPCR will decrease the cost by targeting specific sequences in the target chromosome, and dPCR-based noninvasive testing will facilitate progress toward the implementation of a noninvasive approach for screening for trisomy 21, 18, and 13. In this review, we highlight the principle of dPCR and discuss its future implications in clinical practice.

• Parasites, Hosts and Diseases
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• v.51 no.2
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• pp.177-182
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• 2013

The purpose of the present study was to evaluate the potential role of the 27-Kilodalton (KDa) antigen versus Fasciola gigantica adult worm regurge antigens in a DOT-Blot assay and to assess this assay as a practical tool for diagnosis fascioliasis in Egyptian patients. Fasciola gigantica antigen of an approximate molecular mass 27- (KDa) was obtained from adult worms by a simple elution SDS-PAGE. A Dot-Blot was developed comparatively to adult worm regurge antigens for the detection of specific antibodies from patients infected with F. gigantica in Egypt. Control sera were obtained from patients with other parasitic infections and healthy volunteers to assess the test and compare between the antigens. The sensitivity, specificity, positive and negative predictive values of Dot-Blot using the adult worm regurge were 80%, 90%, 94.1%, and 69.2% respectively, while those using 27-KDa were 100% which confirms the diagnostic potential of this antigen. All patients infected with Fasciola were positive, with cross reactivity reported with Schistosoma mansoni serum samples. This 27-KDa Dot-Blot assay showed to be a promising test which can be used for serodiagnosis of fascioliasis in Egyptian patients especially, those presenting with hepatic disease. It is specific, sensitive and easy to perform method for the rapid diagnosis particularly when more complex laboratory tests are unavailable.

• Nuclear Engineering and Technology
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• v.41 no.1
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• pp.1-10
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• 2009

The safe and reliable performance of fusion and fission plants depends on the choice of suitable materials and an assessment of long-term materials degradation. These materials are degraded by their exposure to extreme conditions; it is necessary, therefore, to address the issue of long-term damage evolution of materials under service exposure in advanced plants. The empirical approach to the study of structural materials and fuels is reaching its limit when used to define and extrapolate new materials, new environments, or new operating conditions due to a lack of knowledge of the basic principles and mechanisms present. Materials designed for future Gen IV systems require significant innovation for the new environments that the materials will be exposed to. Thus, it is a challenge to understand the materials more precisely and to go far beyond the current empirical design methodology. Breakthrough technology is being achieved with the incorporation in design codes of a fundamental understanding of the properties of materials. This paper discusses the multi-scale, multi-code computations and multi-dimensional modelling undertaken to understand the mechanical properties of these materials. Such an approach is envisaged to probe beyond currently possible approaches to become a predictive tool in estimating the mechanical properties and lifetimes of materials.

• Geomechanics and Engineering
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• v.12 no.3
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• pp.483-503
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• 2017

Uncertainty is a fact belonging to engineering practice. An important uncertainty that sets geotechnical engineering is the variability associated with the properties of soils or, more precisely, the characterization of soil profiles. The reason is due largely to the complex and varied natural processes associated with the formation of soil. Spatial variability analysis for the study of the stability of natural slopes, complementing conventional analyses, is able to incorporate these uncertainties. In this paper the characterization is performed in back-analysis for a case of landslide occurred to verify afterwards the presence of the conditions of shear strength at failure. This approach may support designers to make more accurate estimates regarding slope failure responding, more consciously, to the legislation dispositions about slope stability evaluation and future design. By applying different kriging techniques used for spatial analysis it has been possible to perform a 3D-slope reconstruction. The predictive analysis and the areal mapping of the soil mechanical characteristics would support the definition of priority interventions in the zones characterized by more critical values as well as slope potential instability. This tool of analysis aims to support decision-making by directing project planning through the efficient allocation of available resources.

• Environmental and Resource Economics Review
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• v.14 no.1
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• pp.201-220
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• 2005

Recently, we have been witnessing new records of crude oil price hikes. One question which naturally arises would be the possibility and accuracy of forecasting crude oil prices. This study tries to answer the relative predictability of futures prices compared to the forecasts based on experts system. Using WTI crude oil spot and futures prices, this study performs simple statistical comparisons in forecasting accuracy and a formal test of differences in forecasting errors. According to statistical results, WTI crude oil futures market turns out to be equally efficient relative to EIA experts system. Consequently, WTI crude oil futures market could be utilized as a market-based tool for price forecasting and/or resource allocation for both of petroleum producers and consumers.

• The Korean Journal of Rehabilitation Nursing
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• v.17 no.1
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• pp.10-17
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• 2014

Purpose: The Leeds Sleep Evaluation Questionnaire (LSEQ) translated into Korean was modified to easily apply and reduce respondents' confusion and was evaluated for psychometric properties and discriminant ability. Methods: A total of 960 Korean adults aged 45 years and older participated in this cross-sectional survey. To test reliability, validity and discriminant ability, Cronbach's alpha, correlation analysis, confirmatory factor analysis, simple regression analysis and receiver operating characteristics (ROC) curve analysis were used. Results: Item-total correlations ranged between 62~.85 and Cronbach's alpha was .95. Area under ROC was .86 (95% CI: .83~.90) and the optimal cutoff score was identified as ${\leq}$ 66 (sensitivity, .77; specificity, .84; positive/negative predictive values, .49/.95). Using this cutoff score, the prevalence of insomnia in the study sample was 25.8% and tended to be more common in female and older groups. Conclusion: The data supported the psychometric properties of Korean Modified Leeds Sleep Evaluation Questionnaire (KMLSEQ) as an acceptable sleep measurement. In addition, KMLSEQ is likely to be a useful screening tool for insomnia.