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Kapranov, B. I., V. J. Maklashevsky et V. N. Filinov. « ANALYSIS OF MULTIPLE SCATTERING CONTRIBUTION IN THE BACK-SCATTER X-RAY TESTING ». Nondestructive Testing and Evaluation 12, no 5 (janvier 1996) : 305–13. http://dx.doi.org/10.1080/10589759608952854.
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Sladen, J. A., R. D. D'Hollander, J. Krahn et D. E. Mitchell. « Back analysis of the Nerlerk berm liquefaction slides ». Canadian Geotechnical Journal 22, no 4 (1 novembre 1985) : 579–88. http://dx.doi.org/10.1139/t85-077.
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Five liquefaction slides occurred in 1983 during the construction of a hydraulically placed subsea sand berm designed to form part of a bottom-founded, offshore, hydrocarbon exploration platform at Nerlerk in the Canadian Beaufort Sea. These slides were triggered by simple static loading arising from the sand placement itself. Failures started at locally oversteepened side slopes and retrogressed to form bowl-shaped crests. The slide material came to rest beyond the berm at very flat slopes. Stability back analyses reveal that effective stress strength parameters consistent with limiting equilibrium are within the range of the collapse surface parameters determined from triaxial laboratory tests. This finding lends credibility to the collapse surface concepts introduced in another study. Back calculations show that the berm state prior to failure was much looser than the steady state, with the potential for a large strength loss. According to back calculations, the berm density was lower than that inferred from cone penetration tests. Key words: liquefaction, sand, hydraulic fill, slope stability, cone penetration testing.
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Glodež, Srečko, et Marko Šori. « Bending Fatigue Analysis of PM Gears ». Key Engineering Materials 754 (septembre 2017) : 299–302. http://dx.doi.org/10.4028/www.scientific.net/kem.754.299.
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The paper discusses the computational and experimental approach for determination of the PM gears service life concerning bending fatigue in a gear tooth root. A proposed computational model is based on the stress-life approach where the stress field in a gear tooth root is determined numerically using FEM. The experimental procedure was done on a custom made back-to-back gear testing rig. The comparison between computational and experimental results has shown that the proposed computational approach is appropriate calculation method for service life estimation of sintered gears regarding tooth root strength. Namely, it was shown that in the case of proper heat treatment of tested gears, the tooth breakage occurred inside the interval with 95 % probability of failure, which has been determined using proposed computational model.
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Hall, Hubert S., et Curtis Larsen. « Modal testing on a limited budget : Analysis of instrumented hammer alternatives for impact testing ». Journal of the Acoustical Society of America 153, no 3_supplement (1 mars 2023) : A288. http://dx.doi.org/10.1121/10.0018872.
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In recent years, as the use of numerical modeling has increased, organizations have frequently scaled back their experimental capabilities. Often equipment and expertise are no longer available when modal correlation measurements are required. This presentation is part of a planned series examining a minimalist approach to modal testing. In this presentation, alternatives to a traditional instrumented hammer for impact testing are explored. Comparison testing between a dedicated instrumented hammer procured from a leading structural measurement company and commercial hammers acquired from a hardware store was performed. Two cases of commercial hammers were studied, one featuring a force gauge inserted into the impact hammer face and one with an accelerometer attached to the hammer body. A variety of hammer tips were explored for focused frequency content. Follow-on topics include rudimentary data acquisition options and methods of modal data analysis outside of expensive dedicated modal analysis software platforms.
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Chen, Zhi Ge. « The Measurement and Analysis of Clothing Pressure ». Advanced Materials Research 332-334 (septembre 2011) : 1176–79. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.1176.
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The clothing pressure was mainly occurred on the shoulder, arm, back, underarm, elbow. It was tested by using the AMI clothing physiological comfort testing system. Arm moved from 0º to 140º positions in experiment when the clothing pressure was tested. The changes of clothing pressure of loosely fitted clothing are analyzed and discussed in this paper. The largest clothing pressure was occurred on the arm. The experiment results could explain the feelings of pressure properly.
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Mu, Xiao Gang, et Jiao Yang Xia. « The Fitness Characteristics of Elite Female Skaters and Regression Analysis ». Applied Mechanics and Materials 477-478 (décembre 2013) : 341–44. http://dx.doi.org/10.4028/www.scientific.net/amm.477-478.341.
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With the method of ISOMED isokinetic testing system, INBODY 3.0 body composition analyzer and ADIPOMETER subcutaneous fat measuring instrument, this study tries to measure the fitness characteristics of female athletes and then apply mathematical statistics to complete a regression analysis with their results. The main conclusions are as follows: 1. 480°/s hip extensor480°/s knee extensor and 240°/s radios of knee flexor-extensor are highly negative correlated with 500m results, and the regression equation is y = 20.496 - 0.72x1 - 0.64x2 - 0.82x3. 2. Results of the body composition and subcutaneous fat are not highly correlated with 500m result. The hip flexor and extensor at three angular speeds are highly negative correlated with subcutaneous fat of abdomen, upper knee and back, but are highly positive correlated with weight, FFM, BMI and BMR. 3. According to the testing results of body composition, there is no significant difference between two groups, both up to the standard of Asia and world. The maximum value of subcutaneous fat is in abdomen and for another is in upper knees. The minimum value of subcutaneous fat is in outer thigh for long distance athletes and in back for short distance athletes, no significant difference.
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Yan, Shuai, Hong Wang, Yang Chen et An Ye Liu. « Full Power Back-to-Back Test Platform for Large Scale Electrical-Excited Direct Driven Wind Turbine ». Advanced Materials Research 860-863 (décembre 2013) : 1733–37. http://dx.doi.org/10.4028/www.scientific.net/amr.860-863.1733.
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To solve the problem about prototype development of electrical-excited power conversion system of large-scale direct-driven wind turbine and the test challenges during mass-production, advance technology solutions by full power back-to-back testing, focusing on the electrical topology including the key technologies and the working modes. Finally, introduce the relevant standards and the test methods in pilot project, listing part of test results and their analysis.
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Mozumder, Sharif, Michael Dempsey et M. Humayun Kabir. « Back-testing extreme value and Lévy value-at-risk models ». Journal of Risk Finance 18, no 1 (16 janvier 2017) : 88–118. http://dx.doi.org/10.1108/jrf-03-2016-0029.
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Purpose The purpose of the paper is to back-test value-at-risk (VaR) models for conditional distributions belonging to a Generalized Hyperbolic (GH) family of Lévy processes – Variance Gamma, Normal Inverse Gaussian, Hyperbolic distribution and GH – and compare their risk-management features with a traditional unconditional extreme value (EV) approach using data from future contracts return data of S&P500, FTSE100, DAX, HangSeng and Nikkei 225 indices. Design/methodology/approach The authors apply tail-based and Lévy-based calibration to estimate the parameters of the models as part of the initial data analysis. While the authors utilize the peaks-over-threshold approach for generalized Pareto distribution, the conditional maximum likelihood method is followed in case of Lévy models. As the Lévy models do not have closed form expressions for VaR, the authors follow a bootstrap method to determine the VaR and the confidence intervals. Finally, for back-testing, they use both static calibration (on the entire data) and dynamic calibration (on a four-year rolling window) to test the unconditional, independence and conditional coverage hypotheses implemented with 95 and 99 per cent VaRs. Findings Both EV and Lévy models provide the authors with a conservative proportion of violation for VaR forecasts. A model targeting tail or fitting the entire distribution has little effect on either VaR calculation or a VaR model’s back-testing performance. Originality/value To the best of the authors’ knowledge, this is the first study to explore the back-testing performance of Lévy-based VaR models. The authors conduct various calibration and bootstrap techniques to test the unconditional, independence and conditional coverage hypotheses for the VaRs.
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Khan, Md Hasinur Rahaman, et Tamanna Howlader. « Breaking the back of COVID-19 : Is Bangladesh doing enough testing ? » Journal of Biomedical Analytics 3, no 2 (7 septembre 2020) : 25–35. http://dx.doi.org/10.30577/jba.v3i2.46.
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Following detection of the first 100 confirmed cases of COVID-19 in early April, Bangladesh stepped up its efforts to strengthen testing capacity in order to curb the spread of the disease across the country. This paper sheds light on the position of Bangladesh in relation to its South Asian neighbors India and Pakistan with respect to testing capacity and ability to detect cases with increased testing. It also analyzes recent data on case counts and testing numbers in Bangladesh, to provide an idea regarding the number of extra tests needed to detect a substantial number of cases within a short period of time. Findings indicate that compared to India and Pakistan, Bangladesh was able to detect more cases by increasing testing levels and expand its testing capacity by performing more per capita tests. In spite of these achievements, the rate of reported cases per 100 tests was consistently higher for Bangladesh compared to India, which suggests that in addition to increased testing, other factors, such as, effective enforcement of social distancing and efficient contact tracing are just as important in curbing the spread of the disease. The analysis reveals that current testing levels in Bangladesh are not adequate. Based on the findings, we recommend a 30-50\% growth of the current test rate in the next few days so that by detecting and isolating more cases, Bangladesh could, in effect, contain the spread of new infections. The challenge, however, is to mobilize resources necessary to expand geographical coverage and improve testing quality while enforcing social distancing and performing efficient contact tracing.
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Kim, Yun Jae, et Chang Gyun Oh. « Slip Line Field Analysis of Unequally Grooved Specimens in Bending and Its Implication to Constraint Toughness Testing ». Key Engineering Materials 306-308 (mars 2006) : 25–30. http://dx.doi.org/10.4028/www.scientific.net/kem.306-308.25.
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This paper proposes slip line fields for bending of unequally grooved specimens that has a sharp crack in one side and a sharp V-notch in the other side. Depending on the back angle, two slip line fields are proposed, from which the limit moment and crack tip stress fields are obtained as a function of the back angle. Excellent agreements between slip line field solutions with those from detailed finite element limit analysis based on non-hardening plasticity provide confidence in the proposed slip line fields. Based on these results, possibility of designing a new toughness testing specimen with varying crack tip constraint is discussed.
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Farrow, John. « All in the mind : concept analysis in indexing ». Indexer : The International Journal of Indexing : Volume 19, Issue 4 19, no 4 (1 octobre 1995) : 243–47. http://dx.doi.org/10.3828/indexer.1995.19.4.2.
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The indexing process consists of the comprehension of the document to be indexed, followed by the production of a set of index terms. Differences between academic indexing and back-of-book indexing are discussed. Text comprehension is a branch of human information processing, and it is argued that the model of text comprehension and production developed by van Dijk and Kintsch can form the basis for a cognitive process model of indexing. Strategies for testing such a model are suggested.
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Fang, Wei Hua. « Back-Analysis Improved Particle Swarm Optimization Algorithm on Mechanical Parameters of Divisional Geotechnical Engineering Material ». Applied Mechanics and Materials 182-183 (juin 2012) : 1647–53. http://dx.doi.org/10.4028/www.scientific.net/amm.182-183.1647.
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In order to obtain geotechnical engineering material mechanical parameters correctly by using back analysis and overcome shortcoming of ordinary Particle Swarm Optimization, Improved Particle Swarm Optimization (IPSO) algorithm is developed on the aspects such as Stretching Particle, Metropolis Algorithm and adaptive weight updating .at the same time, the algorithm is compared with Catastrophe Particle Swarm Optimization Algorithm (CPSO) and Quantum Particle Swarm Optimization Algorithm(QPSO). Also result of back analysis was compared with that of Ultrasonic Testing and that of mixed-model of dam monitoring. The analysis shows that IPSO has better performance than that of PSO and CPSO, and considerable performance with QPSO.
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Vasoo, Shawn. « Susceptibility Testing for the Polymyxins : Two Steps Back, Three Steps Forward ? » Journal of Clinical Microbiology 55, no 9 (19 juillet 2017) : 2573–82. http://dx.doi.org/10.1128/jcm.00888-17.
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ABSTRACTOptimizing and standardizing susceptibility testing for the polymyxins have become pressing issues, given the rise in multidrug-resistant Gram-negative bacilli. Recently, both the CLSI and EUCAST have recommended broth microdilution (BMD) (without polysorbate) as the reference method for polymyxin susceptibility testing. In this issue, K. L. Chew et al. (J Clin Microbiol 55:2609–2616, 2017,https://doi.org/10.1128/JCM.00268-17) compare the performances of three commercial BMD panels and the Etest to the reference, BMD, for polymyxin B and colistin, using 76Enterobacteriaceaeisolates (21 of which weremcr-1positive). Although none of the commercial BMD panels strictly met FDA performance standards in this evaluation, possibly because of the small number isolates tested, the Sensititre panel achieved >90% categorical agreement for both polymyxin compounds. These results also reaffirm CLSI and EUCAST guidance that gradient diffusion testing, which had unacceptable error rates, should be abandoned. In a simulated analysis with lowered breakpoints (susceptible, ≤1 mg/liter; intermediate, 2 mg/liter; resistant, ≥4 mg/liter), error rates and agreement were improved across the various methods and the rate of detection ofmcr-1-positive isolates improved. These observations, taken together with recent pharmacokinetic data on optimizing target attainment for the polymyxins, suggest that more-stringent (lower) breakpoints may be reasonable, although such an approach may be limited by the inherent reliability of current testing methodologies and a lack of robust clinical correlative data, which are sorely needed.
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Hungerford, John C., et Baron P. Johnson. « Exploratory Biomechanical Studies to Determine Worker Fitness for Manual Material Handling Tasks ». Proceedings of the Human Factors Society Annual Meeting 31, no 4 (septembre 1987) : 452–56. http://dx.doi.org/10.1177/154193128703100415.
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This paper presents the results from two biomechanical studies that examined the effects of loading on the L5/S1 area of the lower spine. The objective of these exploratory studies was to determine whether subject, cardiovascular, and isometric and isotonic strength variables could be used to determine a worker's risk potential for back injury. The first study examined trunk velocity and torque developed in movement against a 30 lb. resistive load for two groups of people: (1) normals (no back pathology), and (2) abnormals (people with physician-diagnosed back pathology). Significant differences were found between these two groups for back torque and velocity measures. People with back pathology developed less torque and were slower in their movements. Discriminant analysis provided an 82% correct classification for normals and abnormals using velocity and torque measurements. The second investigation studied only people with back pathology and its objective was to explore the sensitivity of the testing procedure to distinguish between different degrees of back pathology. The purpose of these studies was to develop measures that could be used to screen and place people in jobs so they would not be at risk for back injury. Further work will aim at: (1) improving the discriminant function used in the first study, (2) searching for additional measures predictive of back injury risk potential, (3) reducing the resistive loads used in testing, and (4) studying non-symmetrical loading effects on the spine.
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Batra, Pete S., Kathy Yappel-Sinkko, James Bena, Jern-Lin Leong, Martin J. Citardi et Donald C. Lanza. « Prospective analysis of epicutaneous testing for inhalant allergy : Comparison of arm and back subsites with mRAST ». Otolaryngology–Head and Neck Surgery 138, no 3 (mars 2008) : 328–33. http://dx.doi.org/10.1016/j.otohns.2007.11.020.
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Zhou, Xinwu, Ryoichi Urayama, Tetsuya Uchimoto et Toshiyuki Takagi. « Application of back-propagation neural networks to defect characterization using eddy current testing ». International Journal of Applied Electromagnetics and Mechanics 64, no 1-4 (10 décembre 2020) : 817–25. http://dx.doi.org/10.3233/jae-209394.
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Eddy current testing is widely used for the automatic detection of defects in conductive materials. However, this method is strongly affected by probe scanning conditions and requires signal analysis to be carried out by experienced inspectors. In this study, back-propagation neural networks were used to predict the depth and length of unknown slits by analyzing eddy current signals in the presence of noise caused by probe lift-off and tilting. The constructed neural networks were shown to predict the depth and length of defects with relative errors of 4.6% and 6.2%, respectively.
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Wang, Zhe, Ximing Cui, Hongbao Ma, Yihua Kang et Zhiyang Deng. « Effect of Surface Roughness on Ultrasonic Testing of Back-Surface Micro-Cracks ». Applied Sciences 8, no 8 (26 juillet 2018) : 1233. http://dx.doi.org/10.3390/app8081233.
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Surface roughness is one of the main factors that affect the ultrasonic testing of micro-cracks. This article theoretically analyzes the relationship between the changes in the energy intensity of crack echo waves and roughness-modified transmission coefficients. A series of simulations are carried out using two-dimensional sinusoidal curves as rough surface. Then, parallel experiments are performed on sample surfaces with different arithmetic average heights (Ra). The signal amplitude ratio factor (SARF) is defined to assess the ultrasonic detection capacity for micro-cracks. Both finite element analysis and experimental results show that signal amplitude decreases with an increase in Ra, resulting in signal-to-noise ratio loss. Amplitude attenuation caused by the rough back surface is less than that caused by the rough front surface. It is difficult to identify the signal of micro-cracks with a depth less than 400 μm when the Ra of the front surface is larger than 15 μm. Cracks with depths of more than 200 μm can be distinguished when the back-surface roughness is less than 24 μm. Furthermore, the amplitude of the micro-crack signal increases slightly with variation in the horizontal parameter (Rsm). This study provides a valuable reference for the precision evaluation of micro-cracks using ultrasonic inspection.
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Zhalezka, B., A. Stadnik et V. Siniauskaya. « TECHNICAL ANALYSIS AND INDICATORS APPLICATION IN ALGORITHMIC MARKETING ». Экономическая наука сегодня, no 15 (19 mai 2022) : 119–30. http://dx.doi.org/10.21122/2309-6667-2022-15-119-130.
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This paper is devoted to the investigation of the stock exchange decision making process by means of technical analysis on the base of indicators. Methods of the basic technical indicators calculation are considered. Trading strategy of the stock exchange decision making based on the new complex specific technical indicator is suggested, which is accounting values of the following basic technical indicators: moving average convergence divergence, parabolic stop and reverse, average directional moving index rating, momentum volume weighted average price. An example of trading strategy automation is considered. Its back testing is realized, which confirms correctness of its application in the stock exchange decision making.
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Nazarenko, Adeline, et Touria Aït El Mekki. « Building back-of-the-book indexes ». Terminology 11, no 1 (17 juin 2005) : 199–224. http://dx.doi.org/10.1075/term.11.1.09naz.
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This paper presents an original natural language processing (NLP) approach for building of back-of-the-book indexes. Our indexing system, IndDoc, exploits some terminological tools and automatically builds an index draft of the analysis of the document text. The indexer then has to validate that index draft through a dedicated interface. This approach has been tested on several documents with promising results. Relying on our experience in developing and testing the IndDoc indexing system, we aim at assessing the contribution of terminological analysis as well as the level of maturity that computational terminology has reached in the indexing perspective.
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Blavt, Oksana, Zinoviy Mykytyuk, Yaroslav Hnatchuk, Oleh Stechkevych et Tetiana Helzhynska. « Intensification of Back Muscle Strength Testing in Physical Education of Students by Applying Information and Communication Technologies ». Teorìâ ta Metodika Fìzičnogo Vihovannâ 22, no 2 (25 juin 2022) : 216–22. http://dx.doi.org/10.17309/tmfv.2022.2.10.
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The purpose of this study is the experimental substantiation of the implementation of information and communication technologies to test the control of back muscle strength in the process of physical education of students.
Materials and methods. General scientific methods were used to solve the research problems: analysis, synthesis, generalization, induction and systematization, technical modeling, pedagogical experiment, pedagogical testing, and mathematical methods. The study involved 240 students aged 17 to 18 at the beginning of the study.
Results. An electronic device for determining the strength of the muscles of the back was developed and tested, the readings of which allow the user to get clear current information on the panel of a personal computer. The device was built on a combination of modern electronic technologies and software. For the purposes of the experimental substantiation of the developed back muscle strength control device, a correlation analysis was used to empirically investigate the authenticity degree of the tests used to control back muscle strength. According to the results of the reliability of the tests of back muscle strength control tests, the results of which were recorded using a dynamometer, those are between low and medium. The recording of the back muscle strength test results with the developed device ensured the achievement of a high level of test authenticity.
Conclusions. The result of the research study aimed at solving the problematic aspects of test control was to ensure the appropriate degree of authenticity of the tests used to control back muscle strength. The recording of the back muscle strength test results with the developed device ensured the achievement of a high level of test authenticity.
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Nurwita, N., K. Krisnaldy, Shelby Virby, Aria Aji Priyanto, Reza Octovian, Dijan Mardiati, Hendri Prasetyo et Robbi Rahim. « Forecasting Provincial Government Expenditures in Indonesia using Artificial Neural Network ». Webology 19, no 1 (28 janvier 2022) : 5664–73. http://dx.doi.org/10.14704/web/v19i1/web19383.
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The purpose of this research is to analyze using artificial neural network techniques in predicting the realization of provincial government spending in Indonesia according to the type of expenditure with Back-Propagation. This research needs to be done because it can be seen from the side of realization of provincial government spending in Indonesia that there can be a surplus and a deficit. Therefore, it is necessary to make predictions as an effort to address this. The data comes from the publication by the Central Statistical Agency of the provincial government of financial statistics (BPS). Financial provincial government data was collected through local government financial surveys from provincial government agencies in Indonesia. The analysis process uses the help of Rapidminer software and is validated with K-Fold values from 2 to 10. The data is divided into training data and testing data. Training data is data from 2016-2018 and testing data is data from 2017-2019. Several architectural models were tested namely '3-2-1; 3-5-1; 3-10-1; 3-5-10-1 'to obtain an accurate prediction by considering the value of Root Mean Square Error (RMSE). The results of the back-propagation analysis state that the 3-5-1 model is the best model with an RMSE value of 0.027 at k-fold = 9 for training data and an RMSE value of 0.035 for testing data. These results confirm that the back-propagation algorithm can be implemented in this case.
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Effraim, Patrick, Mr Napoleon Addison et Mr Abayemah Alphonus Bayor. « Design and Analysis of an Automatic Power Changeover with Backup ». International Journal of Research and Innovation in Applied Science 07, no 08 (2022) : 42–49. http://dx.doi.org/10.51584/ijrias.2022.7806.
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The stability of the power supply in Ghana and another part of Africa is a major concern to the community and shop owners. The need for alternative power supply support and switching of load between two power sources. The system will eliminate the need for manual intervention by sensing the main gridline supply and switching to a backup source. Automation charger over to the backup source will eliminate the delay and provide efficiency in production. The system will automatically switch back when main gridline power is restored back. the system uses a microcontroller as the main automatic changing over the process and other component consists of a power supply circuit consisting of a step-down transformer, rectifier, filter capacitor, voltage regulator, and sg3525 which perform the oscillation convention from DC to AC Renewable energy sources generating direct current will require inverters to produce the alternating current necessary for domestic and industrial use The design, construction, testing of this circuit, is satisfactorily in switching from mains supply to generator/renewable energy source(s) and vice versa.
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NISHIZAWA, Tatsuo, Masaru TERADA, Masayuki YABU, Masashi KOYANAGAWA et Yasushi TAKEUCHI. « EVALUATION OF STRUCTURAL DEGRADATION IN CONCRETE PAVEMENT ON CIRCULAR ACCELERATED PAVEMENT TESTING FACILITY WITH FWD BACK-ANALYSIS ». Journal of Japan Society of Civil Engineers, Ser. E1 (Pavement Engineering) 77, no 1 (2021) : 39–52. http://dx.doi.org/10.2208/jscejpe.77.1_39.
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Kwon, Young Chan, Jae Won Jang, Hwasup Lim et Ouk Choi. « Feasibility Analysis of Deep Learning-Based Reality Assessment of Human Back-View Images ». Electronics 9, no 4 (16 avril 2020) : 656. http://dx.doi.org/10.3390/electronics9040656.
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Realistic personalized avatars can play an important role in social interactions in virtual reality, increasing body ownership, presence, and dominance. A simple way to obtain the texture of an avatar is to use a single front-view image of a human and to generate the hidden back-view image. The realism of the generated image is crucial in improving the overall texture quality, and subjective image quality assessment methods can play an important role in the evaluation. The subjective methods, however, require dozens of human assessors, a controlled environment, and time. This paper proposes a deep learning-based image reality assessment method, which is fully automatic and has a short testing time of nearly a quarter second per image. We train various discriminators to predict whether an image is real or generated. The trained discriminators are then used to give a mean opinion score for the reality of an image. Through experiments on human back-view images, we show that our learning-based mean opinion scores are close to their subjective counterparts in terms of the root mean square error between them.
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Guzman, Edwin R., et Anthony M. Vintzileos. « Computerized analysis of antepartum fetal heart rate tracings ». Fetal and Maternal Medicine Review 9, no 1 (février 1997) : 19–34. http://dx.doi.org/10.1017/s0965539597000028.
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For several decades, visual analysis of the antepartum fetal heart rate tracing has been a primary mode of fetal surveillance despite lack of proof from randomized trials that its use leads to a reduction in perinatal mortality in high risk pregnancies. A meta-analysis of these trials offered the same conclusion. The trials were performed in the early 1980's with fetal monitors with poor signal to noise ratios and poorer testing schemes in comparison to today. Therefore the results may no longer be pertinent, however, it is unlikely that these trials will be repeated because of present medico-legal constraints. Nonetheless, the use of non-stress testing alone is an accepted mode of fetal surveillance because of associated low fetal death rates within 1 week of a normal test; 1.9 to 3.2/1000 patients tested. The expense associated with this low fetal death rate is a low positive predictive value of 25% to 50%. Interrelated with this inefficiency, is the considerable inter- and intra-observer variation in the interpretation of antepartum fetal heart rate tracings. Variation in the interpretation of antepartum fetal heart rate tracings continues to exist despite the increase in experience and knowledge of fetal heart rate monitoring and improvement in fetal heart rate monitors. The end result is a form of fetal surveillance that is of questionable value and inefficient, requiring frequent back up testing to clarify fetal condition.
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Zhou, Lei, Yan Zhen Liu et Chao Zhang. « Multiway Principal Component Analysis for Smartphone Captured Image of Colloidal Gold Strip ». Advanced Materials Research 1035 (octobre 2014) : 483–87. http://dx.doi.org/10.4028/www.scientific.net/amr.1035.483.
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Lateral flow test kit has become a popular device for immunoassay of biologically important molecules. Colloidal gold strip has been commercially available for point-of-care clinical testing at hospital or simply at home for self-testing. A method for reading the reaction results of colloidal gold strip assays is proposed. The RGB (red-green-blue) image of a reacted strip is captured by smartphone under natural-light illumination. The two-dimensional grayscale image of each color channel is transformed into nine images by spatially shifting the image in eight adjacent directions. After all three color channel images are transformed, an array including twenty-seven images is constructed. Multiway principle component analysis is then used to the array, extracting texture information of the original image. When the extracted texture is added back to the original image, color of control line and test line regions can be effectively enhanced for reading by naked eyes.
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Korakakis, Vasileios, Kieran O’Sullivan, Argyro Kotsifaki, Yiannis Sotiralis et Giannis Giakas. « Lumbo-pelvic proprioception in sitting is impaired in subgroups of low back pain–But the clinical utility of the differences is unclear. A systematic review and meta-analysis ». PLOS ONE 16, no 4 (26 avril 2021) : e0250673. http://dx.doi.org/10.1371/journal.pone.0250673.
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Background Altered spinal postures and altered motor control observed among people with non-specific low back pain have been associated with abnormal processing of sensory inputs. Evidence indicates that patients with non-specific low back pain have impaired lumbo-pelvic proprioceptive acuity compared to asymptomatic individuals. Objective To systematically review seated lumbo-pelvic proprioception among people with non-specific low back pain. Methods Five electronic databases were searched to identify studies comparing lumbo-pelvic proprioception using active repositioning accuracy in sitting posture in individuals with and without non-specific low back pain. Study quality was assessed by using a modified Downs and Black’s checklist. Risk of bias was assessed using an adapted tool for cross-sectional design and case–control studies. We performed meta-analysis using a random effects model. Meta-analyses included subgroup analyses according to disability level, directional subgrouping pattern, and availability of vision during testing. We rated the quality of evidence using the GRADE approach. Results 16 studies met the eligibility criteria. Pooled meta-analyses were possible for absolute error, variable error, and constant error, measured in sagittal and transverse planes. There is very low and low certainty evidence of greater absolute and variable repositioning error in seated tasks among non-specific low back pain patients overall compared to asymptomatic individuals (sagittal plane). Subgroup analyses indicate moderate certainty evidence of greater absolute and variable error in seated tasks among directional subgroups of adults with non-specific low back pain, along with weaker evidence (low-very low certainty) of greater constant error. Discussion Lumbo-pelvic proprioception is impaired among people with non-specific low back pain. However, the low certainty of evidence, the small magnitude of error observed and the calculated “noise” of proprioception measures, suggest that any observed differences in lumbo-pelvic proprioception may be of limited clinical utility. PROSPERO-ID CRD42018107671
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Corcoran, Nicole M., Daniel V. McGehee et T. Zachary Noonan. « A temporal analysis of safety drivers taking back control in public roadway automated driving trials ». Proceedings of the Human Factors and Ergonomics Society Annual Meeting 63, no 1 (novembre 2019) : 1532–36. http://dx.doi.org/10.1177/1071181319631377.
Texte intégralRésumé :
In 2019, industry is in the testing stages of level 4 SAE/NHTSA automated vehicles. While in testing, L4 vehicles require a safety driver to monitor the driving task at all times. These specially trained drivers must take back control if the vehicle doesn’t seem to be responding correctly to the ever-changing roadway and environment. Research suggests that monitoring the driving task can lead to a decrease in vigilance over time. Recently, Waymo publicly released takeover request and mileage data on its 2018 L4 autonomous vehicle takeover requests. From this data, which was represented in mileage, we created temporal metric which showed that there were typically 150-250 hours without a takeover request. From this we suggest that there may be a decrement in vigilance for Waymo safety drivers. While there are still many unknowns, we suggest Waymo release takeover requests in terms of time rather than mileage and provide more information on the operational design domains of these vehicles. Expanding the content of this publicly-released data could then give researchers and the public more understanding of the conditions under which safety drivers are functioning.
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den Bandt, Hester L., Winifred D. Paulis, David Beckwée, Kelly Ickmans, Jo Nijs et Lennard Voogt. « Pain Mechanisms in Low Back Pain : A Systematic Review With Meta-analysis of Mechanical Quantitative Sensory Testing Outcomes in People With Nonspecific Low Back Pain ». Journal of Orthopaedic & ; Sports Physical Therapy 49, no 10 (octobre 2019) : 698–715. http://dx.doi.org/10.2519/jospt.2019.8876.
Texte intégral
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Gungoren, Merve Sibel, Deniz Ilhan Topcu et Cevdet Zungun. « The effect of jet-lag on serum concentrations of thyroid stimulating hormone and prolactin ». Biochemia medica 30, no 1 (15 février 2020) : 164–67. http://dx.doi.org/10.11613/bm.2020.011003.
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Introduction: This case report is about the importance of sleeping status for analysis of thyroid hormone stimulating hormone (TSH) and prolactin (PRL) which arose from discordant results of a patient who was referred for serum TSH and PRL testing within 12-hour period after an intercontinental flight. Case description: An adult male patient was admitted to our laboratory for serum TSH and PRL tests and came back questioning the accuracy of his previous results. Further investigations: A new analysis with a new sample was offered. His new results were not consistent with his previous results. What happened: It was revealed that the night before the first sampling, he travelled back to Turkey from The United States of America and came to testing within 12 hours after the arrival. Discussion: Sleeping status is one of the factors that can affect laboratory results. Intercontinental flights causing jet-lag can alter the secretions of TSH and PRL which are predominantly modulated by thyrotropin-releasing hormone (TRH). Main lesson: Travel history and sleeping status are important factors to be evaluated prior sampling for hormone analysis. Patients must be informed about the importance of sampling timing.
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Afzali, Tamana, Henrik Hein Lauridsen, Janus Laust Thomsen, Jan Hartvigsen, Martin Bach Jensen et Allan Riis. « The Online Patient Satisfaction Index for Patients With Low Back Pain : Development, Reliability, and Validation Study ». JMIR Formative Research 5, no 11 (15 novembre 2021) : e21462. http://dx.doi.org/10.2196/21462.
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Background Low back pain is highly prevalent, and most often, a specific causative factor cannot be identified. Therefore, for most patients, their low back pain is labeled as nonspecific. Patient education and information are recommended for all these patients. The internet is an accessible source of medical information on low back pain. Approximately 50% of patients with low back pain search the internet for health and medical advice. Patient satisfaction with education and information is important in relation to patients’ levels of inclination to use web-based information and their trust in the information they find. Although patients who are satisfied with the information they retrieve use the internet as a supplementary source of information, dissatisfied patients tend to avoid using the internet. Consumers’ loyalty to a product is often applied to evaluate their satisfaction. Consumers have been shown to be good ambassadors for a service when they are willing to recommend the service to a friend or colleague. When consumers are willing to recommend a service to a friend or colleague, they are also likely to be future users of the service. To the best of our knowledge, no multi-item instrument exists to specifically evaluate satisfaction with information delivered on the web for people with low back pain. Objective This study aims to report on the development, reliability testing, and construct validity testing of the Online Patient Satisfaction Index to measure patients’ satisfaction with web-based information for low back pain. Methods This is a cross-sectional validation study of the Online Patient Satisfaction Index. The index was developed with experts and assessed for face validity. It was subsequently administered to 150 adults with nonspecific low back pain. Of these, 46% (70/150) were randomly assigned to participate in a reliability test using an intraclass correlation coefficient of agreement. Construct validity was evaluated by hypothesis testing based on a web app (MyBack) and Wikipedia on low back pain. Results The index includes 8 items. The median score (range 0-24) based on the MyBack website was 20 (IQR 18-22), and the median score for Wikipedia was 12 (IQR 8-15). The entire score range was used. Overall, 53 participants completed a retest, of which 39 (74%) were stable in their satisfaction with the home page and were included in the analysis for reliability. Intraclass correlation coefficient of agreement was estimated to be 0.82 (95% CI 0.68-0.90). Two hypothesized correlations for construct validity were confirmed through an analysis using complete data. Conclusions The index had good face validity, excellent reliability, and good construct validity and can be used to measure satisfaction with the provision of web-based information regarding nonspecific low back pain among people willing to access the internet to obtain health information. Trial Registration ClinicalTrials.gov NCT03449004; https://clinicaltrials.gov/ct2/show/NCT03449004
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Li, Shili, Peiyu Qin, Weixi Yang et Wei Fan. « Research on strain testing technology of electromagnetic railgun’s abnormal barrel ». Journal of Physics : Conference Series 2478, no 12 (1 juin 2023) : 122016. http://dx.doi.org/10.1088/1742-6596/2478/12/122016.
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Abstract Aiming at difficult strain test and unable to accurate strain test for electromagnetic railgun’s special-shaped barrel bore, the strain testing technology of special-shaped barrel was studied. According to electromagnetic railgun strain test characteristics analysis, the back of the rail and the back of insulation support plate are selected as the strain test points, FBG(Fiber Bragg Grating) stain sensor is embedded along the circumference of the barrel to obtain the special-shaped barrel true stain value. At the same time, in order to comparison, The papers studies the rail’s strain simulation technology for electromagnetic railgun, the simulation result is accordance with strain test result, show that stain measurement method is feasible, and measurement results is reliable. The research results can provide data support for location to position of projectile in the special-shaped barrel bore by strain feature.
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Adamovský, R., L. Mašek et P. Neuberger. « Analysis of rock mass borehole temperatures with vertical heat exchanger ». Research in Agricultural Engineering 58, No. 2 (13 juin 2012) : 57–65. http://dx.doi.org/10.17221/43/2011-rae.
Texte intégralRésumé :
The goal of the article is to analyze the distribution and changes of temperatures in boreholes with the rock mass/fluid tubular heat exchangers used as an energy source for the heat pump. It also aims at documenting changes of temperatures in the rock mass during stagnation and heat extraction, and to compare the temperatures in the active and referential borehole. The testing results showed that temperatures of the rock mass reached a minimal value of 1.3°C at depths of 9 m and 20 m with maximal heat extraction corresponding to minimal air temperatures. The temperatures of the rock mass increased near the end of the heating season to values which correspond to the initial values. The temperature differences of the rock mass between the reference borehole and active boreholes increased to up to 10.5 K during the heating season. However, the temperature differences at the end of the heating season between the reference and active boreholes dropped back to 0.5–1.1 K.
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Qingbiao, Wang, Zhang Cong, LÜ Rongshan, Wen Xiaokang, Xu Lei, Wang Tiantian et Zhang Junxian. « Steel Plastic Geogrid Performance Testing and its Application in the Reduction of Spring Back of Shotcrete ». Open Construction and Building Technology Journal 9, no 1 (10 septembre 2015) : 223–29. http://dx.doi.org/10.2174/1874836801509010223.
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In order to solve the problems of high springback of sprayed concrete and high dust concentration in the boltnetting support of underground engineering, research the mechanical properties of steel plastic geogrid and analyze the application of steel plastic geogrid replacing the metal net in the reduction of concrete through theoretical study, laboratory test, field test and contrast analysis, thus got the conclusion that: (1) Through the analysis of influence factors of the springback of surrounding rock supporting sprayed concrete, classification is carried on with the sampling survey method. The interaction between the metal net and concrete is the main factor to influence the springback of the concrete. (2) Study the performance differences of the steel plastic geogrid and the metal net. With the advantages of tensile strength, strong durability and injection connection, steel plastic geogrid has stronger applicability, safety and stability in adjusting the stress of the surrounding rock of the roadway and coordinating its deformation. (3)Through the tensile test and the deflection test, study the relationship between the tensile strength and external load under different aperture, thus establish the relation curve between the maximum deflection and load. (4) Through the roadway engineering construction and the analysis of the data of the field test, steel plastic geogrid can greatly reduce the springback of sprayed concrete which can guide the design and construction of underground bolt-netting support engineering.
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Zhu, Hai Tao, et Jia Lin Yang. « Dynamics Analysis of Vehicle Rollover Test Based on SAE J2114 ». Applied Mechanics and Materials 543-547 (mars 2014) : 105–10. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.105.
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SAE J2114 test method has simulated the recurrence of passenger vehicle rollover form in the traffic accident, mainly including the rollover stage and tumbling stage. In this paper, the whole rolling process of passenger vehicle are analyzed in mechanical model by the testing method, such as the critical condition of rolling ; the condition affecting the vehicle back weeks on the air parabolic motion stage; the condition affecting rolling strength on the landing stage. Furthermore, the article has used MATLAB tools to analyze the relationship of four factors ,which are the critical speed, wheel base, center of gravity height and radius of the rolling ,and the results will help us better understand the collision shape, providing theoretical basis for accident reappearance.
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Wang, Qi. « Lab Windows/CVI Platform-Based Cable and Harness Test System Software Design ». Advanced Materials Research 301-303 (juillet 2011) : 977–82. http://dx.doi.org/10.4028/www.scientific.net/amr.301-303.977.
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As a link maintaining an interconnection relationship, the cable and harness are widely used for many fields such as electronic measurement, chemical industry, electric engineering, mineral exploration, medical treatment, vibration analysis, acoustic analysis, fault diagnosis and teaching & research etc, so the testing of cable and harness is very important. This system utilized Lab Windows/CVI as the core control software, developed the cable and harness test software system on the basis of hardware equipment. According to the different properties of testing parameters, respectively designed the corresponding test methods, through software setting, process and compare the data read-back, and determine whether the technical parameters of cable and harness are qualified or not according to the specified determination basis.
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Ferrari, Pierpaolo, Gabriele Poy et Guido Abate. « Dispersion trading : an empirical analysis on the S&P 100 options ». Investment Management and Financial Innovations 16, no 1 (6 mars 2019) : 178–88. http://dx.doi.org/10.21511/imfi.16(1).2019.14.
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This study provides an empirical analysis back-testing the implementation of a dispersion trading strategy to verify its profitability. Dispersion trading is an arbitrage-like technique based on the exploitation of the overpricing of index options, especially index puts, relative to individual stock options. The reasons behind this phenomenon have been traced in literature to the correlation risk premium hypothesis (i.e., the hedge of correlations drifts during market crises) and the market inefficiency hypothesis. This study is aimed at evaluating whether dispersion trading can be implemented with success, with a focus on the Standard & Poor’s 100 options. The risk adjusted return of the strategy used in this empirical analysis has beaten a buy-and-hold alternative on the S&P 100 index, providing a significant over-performance and a low correlation with the stock market. The findings, therefore, provide an evidence of inefficiency in the US options market and the presence of a form of “free lunch” available to traders focusing on options mispricing.
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Dwipayana, Bagus, et Eka Sulistyawati. « PERAN KEPUASAN DALAM MEMEDIASI PENGARUH KEPERCAYAAN TERHADAP NIAT BELI ULANG PADA GO-FOOD DI FEB UNUD ». E-Jurnal Manajemen Universitas Udayana 7, no 10 (24 juillet 2018) : 5197. http://dx.doi.org/10.24843/ejmunud.2018.v07.i10.p01.
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The intention to reuse goods or services is a reflection of the services that quality companies offer so that customers feel satisfied. Referring to the theory of consumer behavior, this study aims to determine the effect of trust and satisfaction with the intention to buy back. The study was conducted in 1873 students of the Faculty of Economics and Business Udayana University, a sample of 95 students was obtained. Analytical technique used is factor analysis and path analysis. The results of testing the first hypothesis shows the positive effect of trust on the intention to buy back. Results of the second hypothesis show satisfaction positive effect on trust. The results of the third hypothesis show satisfaction positive effect on the intention of buy back, and the last fourth hypothesis shows that satisfaction mediates positively the relationship between beliefs on repurchase intentions. The high level of trust and consumer satisfaction will increase the chances of re-buying intention from consumers.
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Maina, James, Wynand JvdM Steyn, Emile B. van Wyk et Frans le Roux. « Static and Dynamic Backcalculation Analyses of an Inverted Pavement Structure ». Advanced Materials Research 723 (août 2013) : 196–203. http://dx.doi.org/10.4028/www.scientific.net/amr.723.196.
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A crucial part of any maintenance strategy is an intricate understanding of the material characteristics of the pavement, so that the current level of damage may be accurately assessed and an appropriate plan implemented. Advances in the precision to which these parameters can be determined, as well as improvements in how these results are interpreted under varying conditions of measurement and analysis, are essential in the effective execution of a maintenance strategy. Results from Falling Weight Deflectometer (FWD), which is a Non-Destructive Testing (NDT) device, can be used to predict elastic modulus of any layer by comparing measured deflection data to calculated values through an iterative process referred to as back-calculation. This paper presents a comparison between static and dynamic back-calculation procedures, specifically with regard to typical South African inverted pavements. The analysis indicates a dynamic analysis provides results of greater accuracy than a static analysis, although the effect of the difference requires further investigation.
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Konrad, J. M., et B. D. Watts. « Undrained shear strength for liquefaction flow failure analysis ». Canadian Geotechnical Journal 32, no 5 (1 octobre 1995) : 783–94. http://dx.doi.org/10.1139/t95-076.
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An important factor in evaluating the stability of hydraulic fills against flow sliding is the undrained steady-state strength mobilized in the field. This paper proposes an empirical relationship between three factors: the undrained strength back-calculated from fills that failed by flow sliding, equivalent clean sand normalized blow-count values, and soil-specific parameters from steady-state laboratory testing. It is shown that Suo, which is a reference value of steady-state strength at maximum void ratio, is an important soil parameter. The proposed method offers an explanation for the performance of many artificial sand islands in the Beaufort Sea, indicates the extreme sensitivity of Suo to soil type and the usefulness of Suo for assessing the potential strength loss of soils for use in safety assessments of existing hydraulic fills. Key words : undrained strength, liquefaction, sand, field, case-histories, analysis.
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Wang, Yuling, Yunshuang Xiang et Huan Zhang. « Comparison and Forecasting of VaR Models for Measuring Financial Risk : Evidence from China ». Discrete Dynamics in Nature and Society 2022 (26 mars 2022) : 1–12. http://dx.doi.org/10.1155/2022/5510721.
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With increasing extremal risk, VaR has been becoming a popular methodology because it is easy to interpret and calculate. For comparing the performance of extant VaR models, this paper makes an empirical analysis of five VaR models: simple VaR, VaR based on RiskMetrics, VaR based on different distributions of GARCH-N, GARCH-GED, and GARCH-t. We exploit the daily closing prices of the Shanghai Composite Index from January 4, 2010, to April 8, 2020, and divide the entire sample into two periods for empirical analysis. The rolling window is used to update the daily estimation of risk. Based on the failure rates under different significance levels, we test whether a specific VaR model passes the back-testing. The results indicate that all models, except the RiskMetrics model, pass the test at a 5% level. According to the ideal failure rate, only the GARCH-GED model can pass the test at a 1% level. For the Kupiec confidence interval, the GARCH-t model can also pass the back-testing at all aforementioned levels. Particularly, we find that the GARCH-GED model has the lowest forecasting failure rate in the class of GARCH models.
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Zhang, Zhi Ying, et Jia Hua Lu. « An Cold Experimental Analysis of Draught System with Chain-Grate Stoker ». Advanced Materials Research 230-232 (mai 2011) : 1236–41. http://dx.doi.org/10.4028/www.scientific.net/amr.230-232.1236.
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The study of cold state testing and evaluation analysis were carried on the practical running chain-grate stoker, which has an air-supply system with air storehouse and airtrough, to study the air-distribution, air leakage, air tightness and air governing. The result shows that horizontal air distribution across the furnace and the air tightness of the components such as the air port (damper) and airtrough are good. However the air leakage is large because of the complex structure and the high demand of integrated air tightness either in the front or the back of the stoker. The cost of the stoker is high because of large quantity of machine work after casting and high demand of installation, thus the structure should be improved.
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Chen, Chao-Rong, Chia-Hung Wu et Hsin-Tsrong Lee. « Determination of Optimal Drop Height in Free-Fall Shock Test Using Regression Analysis and Back-Propagation Neural Network ». Shock and Vibration 2014 (2014) : 1–10. http://dx.doi.org/10.1155/2014/264728.
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The primary purpose of this study is to provide methods that can be used to determine the most suitable drop height for shock testing military equipment, in an efficient and cost ineffective manner. Shock testing is widely employed to assess the performance of electronic systems, including military devices and civilian systems. Determining the height of the drop for a test item is an important step prior to performing the test. Dropping a test item from excessive height leads high G-peak values to damage the test equipment. On the other hand, dropping an item from a low height may not generate the required G-peak value and duration. Therefore, prior to performing shock tests, an optimal drop height must be established to ensure that the resulting G-peak value and duration time match the required test values. The traditional trial-and-error methods are time-consuming and cost-ineffective, often requiring many attempts. To improve the conventional approaches, this study proposes the application of regression analysis and back-propagation neural network for determining the most suitable drop height for free-fall shock tests. A new method is suggested for determining the drop test height. The results of the model are verified, using the results of a series of experiments that are conducted to verify the accuracy of the suggested approaches. The results of the study indicate that both approaches are equally effective in providing an effective guideline for performing drop tests from heights that would result in the peak Gs and duration needed for testing electronic devices.
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Song, Zhan-ping, An-nan Jiang et Zong-bin Jiang. « Back Analysis of Geomechanical Parameters Using Hybrid Algorithm Based on Difference Evolution and Extreme Learning Machine ». Mathematical Problems in Engineering 2015 (2015) : 1–11. http://dx.doi.org/10.1155/2015/821534.
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Since the geological bodies where tunnels are located have uncertain and complex characteristics, the inverse problem plays an important role in geotechnical engineering. In order to improve the accuracy and speed of surrounding rock identification, the back analysis objective function with usage of the displacement and stress monitoring data has been constructed, with a hybrid algorithm proposed. An extreme learning machine (ELM) is employed with optimal architecture trained by the difference evolution (DE) arithmetic. First, the three-dimensional numerical simulation is used in the creation of training and testing samples for ELM model construction. Second, the nonlinear relationship between rock parameters and displacement is constructed by numerical simulation. Finally, the geophysics parameters are obtained by DE optimization arithmetic taking into consideration the monitoring data including both displacement and pressure. This method had been applied in the Fusong highway tunnel in Fusong City of China’s Jilin Province, with a good effect obtained. It takes full advantage of DE and ELM and has both calculation speed and precision in the back analysis.
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Loh, Tick Boon, Yutong Wu, Siang Huat Goh, Kian Hau Kong, Kheng Lim Goh et Jun Jie Chong. « An Integrated Approach for the Determination of Young’s Modulus of a Cantilever Beam Using Finite Element Analysis and the Digital Image Correlation (DIC) Technique ». Electronics 11, no 18 (7 septembre 2022) : 2826. http://dx.doi.org/10.3390/electronics11182826.
Texte intégralRésumé :
This paper is an extended paper from the 24th International Conference on Mechatronics Technology, ICMT 2021. The basic mechanical characteristic that gauges the stiffness of a solid material is known as the Young’s modulus. To evaluate the Young’s modulus, destructive material testing is frequently used. This paper describes how to determine a material’s dynamic Young’s modulus using Digital Image Correlation (DIC) in conjunction with numerical back-analysis. Three different materials (brass, aluminum, and steel) were examined for their static and dynamic reactions. A static transverse displacement was first applied at the free end of the beam before it was released and the beam was allowed to vibrate freely. The resulting vibrations at the free end were monitored using the DIC method, following which the natural frequencies of the beam were derived by applying the Fast Fourier Transform (FFT) to the DIC measured time history. The Young’s modulus corresponding to the fundamental natural frequency of the beam was then obtained via modal back-analysis using the finite element program Ansys 2022 R1. In this way, the Young’s modulus of the material may be calculated using a combination of numerical and DIC techniques, thus allowing for the non-contact evaluation of the structural integrity without subjecting the material to destructive testing. Potential applications of this method include bridge and building assessments, and structural health monitoring (SHM).
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Harikrishnan, J. Pradeep M., et K. Vijayakumar. « Performance Analysis of Neural Network Based Classifiers for the Prediction of Diabetes ». MOLECULAR SCIENCES AND APPLICATIONS 2 (26 avril 2022) : 24–28. http://dx.doi.org/10.37394/232023.2022.2.4.
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Diabetes is the most harmful diseases to consider in recent years since it causes severe damage to human beings in the form of elevated sugar levels. In a recent survey, it was projected that over 385 million public were affected in the entire world. Several investigators were conducted various experiments for prediction of diabetes using various classification techniques. This paper deals with a neural classifier based prediction system to recognize diabetes. Two learning algorithms namely, Levenberg Marquardt back propagation (LM), and gradient descent with variable learning rate are is investigated for different architecture and the best architecture with good accuracy was identified. The data are together from the Government Hospital of Pondicherry and it is formed as a database. Totally, datasets of 500 have been together, out of which 350 datasets as training sets for training process and 150 datasets as testing sets for the testing process. The recognition accuracy is obtained. For comparison, k-Nearest Neigourhood and the K- nearest neighbor and Radial Basis Function (RBF) network are also implemented and it is trained and tested with the same datasets. The result shows that Neural Network outperforms well with other classifiers.
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Harikrishnan, J. Pradeep M., et K. Vijayakumar. « Performance Analysis of Neural Network Based Classifiers for the Prediction of Diabetes ». MOLECULAR SCIENCES AND APPLICATIONS 2 (26 avril 2022) : 24–28. http://dx.doi.org/10.37394/232023.2022.2.4.
Texte intégralRésumé :
Diabetes is the most harmful diseases to consider in recent years since it causes severe damage to human beings in the form of elevated sugar levels. In a recent survey, it was projected that over 385 million public were affected in the entire world. Several investigators were conducted various experiments for prediction of diabetes using various classification techniques. This paper deals with a neural classifier based prediction system to recognize diabetes. Two learning algorithms namely, Levenberg Marquardt back propagation (LM), and gradient descent with variable learning rate are is investigated for different architecture and the best architecture with good accuracy was identified. The data are together from the Government Hospital of Pondicherry and it is formed as a database. Totally, datasets of 500 have been together, out of which 350 datasets as training sets for training process and 150 datasets as testing sets for the testing process. The recognition accuracy is obtained. For comparison, k-Nearest Neigourhood and the K- nearest neighbor and Radial Basis Function (RBF) network are also implemented and it is trained and tested with the same datasets. The result shows that Neural Network outperforms well with other classifiers.
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Sukono, F., Eman Lesmana, Dwi Susanti, Herlina Napitupulu et Yuyun Hidayat. « Estimation of Value-at-Risk Adjusted under the Capital Asset Pricing Model Based on ARMAX-GARCH Approach ». Jurnal Matematika Integratif 15, no 1 (25 juillet 2019) : 29. http://dx.doi.org/10.24198/jmi.v15.n1.20931.29-37.
Texte intégralRésumé :
Investors having an understanding of investment statistics are important. Especially quantitative tools related to investment risk measurement. Value-at-Risk Adjusted is one of the investment risk measurement tools, which assumes that returns are not normally distributed.This paper intends to measure investment risk based onValue-at-Risk Adjustedor called Modified Value-at-Risk under the Capital Asset Pricing Model. It is assumed that the return of the market index has a non-constant average and there is a long memory effect. The average of the return of the market index is estimated using ARFIMA models.It is also assumed that the stock risk premium correlates with market risk premiums, and stock risk premiums some time before. The correlation will be analyzed using the ARMAX-GARCH model approach. The Modified Value-at-Risk was then formulated based on the Capital asset Pricing Model with the ARMAX-GARCH model approach.To measure the performance of Modified Value-at-Risk that has been formulated is done with back testing. Back testing is carried out based on the Lopez II method. As a case study, analyzed some data on 10 stocks traded on the capital market in Indonesia.The results of the analysis show that the market index return risk premium significantly follows the ARFIMA model, and the 10 share risk premium significantly follows the ARMAX-GARCH model. Based on the results of back testing calculations indicate that the Value-at-Risk Adjustedor Modified Value-at-Risk is very suitable to be used to measure investment risk in the 10 stocks analyzed.
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Sukono, F., Eman Lesmana, Dwi Susanti, Herlina Napitupulu et Yuyun Hidayat. « Estimation of Value-at-Risk Adjusted under the Capital Asset Pricing Model Based on ARMAX-GARCH Approach ». Jurnal Matematika Integratif 15, no 1 (25 juillet 2019) : 29. http://dx.doi.org/10.24198/jmi.v15i1.20931.
Texte intégralRésumé :
Investors having an understanding of investment statistics are important. Especially quantitative tools related to investment risk measurement. Value-at-Risk Adjusted is one of the investment risk measurement tools, which assumes that returns are not normally distributed.This paper intends to measure investment risk based onValue-at-Risk Adjustedor called Modified Value-at-Risk under the Capital Asset Pricing Model. It is assumed that the return of the market index has a non-constant average and there is a long memory effect. The average of the return of the market index is estimated using ARFIMA models.It is also assumed that the stock risk premium correlates with market risk premiums, and stock risk premiums some time before. The correlation will be analyzed using the ARMAX-GARCH model approach. The Modified Value-at-Risk was then formulated based on the Capital asset Pricing Model with the ARMAX-GARCH model approach.To measure the performance of Modified Value-at-Risk that has been formulated is done with back testing. Back testing is carried out based on the Lopez II method. As a case study, analyzed some data on 10 stocks traded on the capital market in Indonesia.The results of the analysis show that the market index return risk premium significantly follows the ARFIMA model, and the 10 share risk premium significantly follows the ARMAX-GARCH model. Based on the results of back testing calculations indicate that the Value-at-Risk Adjustedor Modified Value-at-Risk is very suitable to be used to measure investment risk in the 10 stocks analyzed.
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Budiarti, Putria Widya, Teuku Faisal Fathani et Fikri Faris. « Analysis of rainfall-triggered landslide in Baleagung Village, Magelang Regency, Central Java ». E3S Web of Conferences 200 (2020) : 01001. http://dx.doi.org/10.1051/e3sconf/202020001001.
Texte intégralRésumé :
The majority of Magelang Regency is considered as intermediate and high susceptible areas against landslide. As happened in Baleagung Village in January 2018, a landslide has damaged local residency buildings. The landslide occurred because of high-intensity rainfall on the day before. Meanwhile, cracks formed in several areas that were indicated by the slope around the village were still actively moving. Therefore, mitigation is urgently needed to minimize the risk of further landslide movement. This study aimed to analyze the mechanism of ground movement at Baleagung Village which was affected by rainfall. This research was conducted by using back-analysis method to determine the initial groundwater level conditions and its effect on the slope stability. Soil parameters were obtained by laboratory testing and permeability tests in the field. Subsequently, rainfall data was collected from Himawari-8 satellite and used as the data input parameter for numerical analysis using SEEP/W and SLOPE/W. The results obtained from back-analysis showed that rainfall infiltration into the soil affected the degradation of safety factor value that was caused by the increase of pore-water pressure and the decrease of effective stress in a certain period. The degradation of safety factor was caused by the increasing of soil saturation degree when water infiltrated into the ground.