Relevant bibliographies by topics / Ratio Type Estimators

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Academic literature on the topic 'Ratio Type Estimators'

Author: Grafiati
Published: 8 September 2023

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Journal articles on the topic "Ratio Type Estimators"

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Ijaz, Muhammad, Syed Muhammad Asim, Atta ullah, and Ibrahim Mahariq. "Flexible Robust Regression-Ratio Type Estimators and Its Applications." Mathematical Problems in Engineering 2022 (September 28, 2022): 1–6. http://dx.doi.org/10.1155/2022/8977392.

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In real-world situations, the data set under examination may contain uncommon noisy measurements that unreasonably affect the data’s outcome and produce incorrect model estimates. Practitioners employed robust-type estimators to reduce the weight of the noisy measurements in a data set in such a scenario. Using auxiliary information that will produce reliable estimates, we have looked at a few flexible robust-type estimators in this study. In order to estimate the population mean, this study presents unique flexible robust regression type ratio estimators that take into account the data from the midrange and interdecile range of the auxiliary variables. Up to the first order of approximate computation, the bias and mean square were calculated. In order to compare the flexibility of the proposed estimator to those of the existing estimators, theoretical conditions were also obtained. We took into account data sets containing outliers for empirical computation, and it was found that the suggested estimators produce results with higher precision than the existing estimators.
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Kumari, Chandni, and Ratan Kumar Thakur. "Improved Ratio Type Estimators Using Auxiliary Attribute for Population Variance." International Journal of Science and Research (IJSR) 9, no. 4 (April 5, 2020): 1491–98. http://dx.doi.org/10.21275/sr20426180318.

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Raghav, Yashpal Singh. "Neutrosophic Generalized Exponential Robust Ratio Type Estimators." International Journal of Analysis and Applications 21 (May 1, 2023): 41. http://dx.doi.org/10.28924/2291-8639-21-2023-41.

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Estimators proposed under classical statistics fail if data are vague or indeterminate. Neutrosophic Statistics are the only alternative because its deal with indeterminacy. Extensive reserch has been conducted in this field because of its wide applicability. This study aimed to further develop the theory of neutosophic simple random sampling without replacement. In this study, a generalized neutrosophic exponential robust ratio-type estimator was proposed, and five of its member neutrosophic estimators were developed. Derivations of the bias and Mean Square Error were provided up to the first-order approximation. To demonstrate the high efficiency of the proposed neutrosophic estimators an empirical study on the stock price of Moderna and four simulation studies have been conducted, and the results show that the proposed neutrosophic estimators are more efficient than similar existing ratio type estimators discussed in this paper in neutrosophic as well as classical forms.
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Bahl, Shashi, and Meenu Nain. "Difference-cum-ratio type estimators." Journal of Statistics and Management Systems 2, no. 1 (March 1999): 1–8. http://dx.doi.org/10.1080/09720510.1999.10700986.

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Tankou, Victoire, and Sudhakar Dharmadhikari. "Improvement of Ratio-Type Estimators." Biometrical Journal 31, no. 7 (1989): 795–802. http://dx.doi.org/10.1002/bimj.4710310705.

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Malik, Sachin, and Rajesh Singh. "Some Improved Multivariate-Ratio-Type Estimators Using Geometric and Harmonic Means in Stratified Random Sampling." ISRN Probability and Statistics 2012 (August 26, 2012): 1–7. http://dx.doi.org/10.5402/2012/509186.

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Auxiliary variable is commonly used in survey sampling to improve the precision of estimates. Whenever there is auxiliary information available, we want to utilize it in the method of estimation to obtain the most efficient estimator. In this paper using multiauxiliary information we have proposed estimators based on geometric and harmonic mean. It was also shown that estimators based on harmonic mean and geometric mean are less biased than Olkin (1958) and Singh (1967) estimators under certain conditions. However, the MSE of Olkin (1958) estimator and geometric and harmonic estimators are same up to the first order of approximations.
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Subramani, J., and G. Kumarapandiyan. "A Class of Modified Ratio Estimators for Estimation of Population Variance." Journal of Applied Mathematics, Statistics and Informatics 11, no. 1 (May 1, 2015): 91–114. http://dx.doi.org/10.1515/jamsi-2015-0006.

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Abstract In this paper we have proposed a class of modified ratio type variance estimators for estimation of population variance of the study variable using the known parameters of the auxiliary variable. The bias and mean squared error of the proposed estimators are obtained and also derived the conditions for which the proposed estimators perform better than the traditional ratio type variance estimator and existing modified ratio type variance estimators. Further we have compared the proposed estimators with that of the traditional ratio type variance estimator and existing modified ratio type variance estimators for certain natural populations.
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Rather, Khalid Ul Islam, Eda Gizem Koçyiğit, Ronald Onyango, and Cem Kadilar. "Improved regression in ratio type estimators based on robust M-estimation." PLOS ONE 17, no. 12 (December 12, 2022): e0278868. http://dx.doi.org/10.1371/journal.pone.0278868.

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In this article, a new robust ratio type estimator using the Uk’s redescending M-estimator is proposed for the estimation of the finite population mean in the simple random sampling (SRS) when there are outliers in the dataset. The mean square error (MSE) equation of the proposed estimator is obtained using the first order of approximation and it has been compared with the traditional ratio-type estimators in the literature, robust regression estimators, and other existing redescending M-estimators. A real-life data and simulation study are used to justify the efficiency of the proposed estimators. It has been shown that the proposed estimator is more efficient than other estimators in the literature on both simulation and real data studies.
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Agbebia, C. S., and E. I. Enang. "Calibration Approach Ratio Estimators of Population Median in Stratified Random Sampling Design." Asian Journal of Probability and Statistics 21, no. 4 (March 29, 2023): 64–77. http://dx.doi.org/10.9734/ajpas/2023/v21i4472.

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Median as a measure of location gives a more robust estimate than the mean when dealing with heavy tailed or skewed distributions. It can also be used in cases of qualitative variables and open end intervals. Calibration, an approach that adjusts the original design weight by incorporating auxiliary information is employed using the chi square distance measure on a ratio median estimator under stratified random sampling to propose some estimators of population median. These proposed estimators are: the regression and ratio-type calibrated estimators with one constraint and the regression and ratio-type calibrated estimators with two constraints. The estimators of variance of these proposed estimators are also obtained. Empirical investigations on the performance of these estimators are carried out using R software simulated data set under underlying distributional assumptions of Cauchy and Lognormal, for sample sizes of 10%, 20% and 25%. The results showed that the proposed regression and ratio-type calibrated estimators with one constraint and the regression-type calibrated estimator with two constraints were more efficient than the existing ratio estimator and the proposed ratio-type calibrated estimator under two constraints for both Cauchy and the lognormal distributions.
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IJAZ, MUHAMMAD, ATTA ULLAH, and TOLGA ZAMAN. "ON THE DEVELOPMENT OF RATIO TYPE ESTIMATORS USING AUXILIARY INFORMATION." Journal of Science and Arts 21, no. 1 (March 30, 2021): 163–70. http://dx.doi.org/10.46939/j.sci.arts-21.1-a14.

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The paper produces some new modified forms of the ratio estimators using the auxiliary information. The large sample properties, that is, the bias and mean squared error up to the first order of approximation are determined. The comparison is made with other existing estimators by using an applied data. It has been observed that the proposed estimators have a fewer mean squared error and leads to the efficient results as compared to the classical ratio estimator, Sisodia and Dwivedi, Singh and Kakran, Upadhyaya and Singh estimators.
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Books on the topic "Ratio Type Estimators"

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Walsh, Bruce, and Michael Lynch. Using Molecular Data to Detect Selection: Signatures from Multiple Historical Events. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198830870.003.0010.

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This chapter examines the search for a pattern of repetitive adaptive substitutions over evolutionary time. In contrast with the previous chapter, only a modest number of tests toward this aim have been proposed. The HKA and McDonald-Kreitman tests contrast the polymorphism to divergence ratio between different genomic classes (such as different genes or silent versus replacement sites within the same gene). These approaches can detect an excess of substitutions, which allows one to estimate the fraction of adaptive sites. This chapter reviews the empirical data on estimates of this fraction and discusses some of the sources of bias it its estimation. Over an even longer time scale, one can contrast the rate of change of sites in a sequence over a phylogeny. These tests require a rather special type of selection, wherein the same specific site (usually a codon) experiences multiple adaptive substitutions over a phylogeny, such as might occur in arms-race genes.
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Book chapters on the topic "Ratio Type Estimators"

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Zahid, Sara, Asifa Kamal, and Mahnaz Makhdum. "Generalized Dual to Exponential Ratio Type Estimator for the Finite Population Mean in the Presence of Nonresponse." In Promoting Statistical Practice and Collaboration in Developing Countries, 249–63. Boca Raton: Chapman and Hall/CRC, 2022. http://dx.doi.org/10.1201/9781003261148-23.

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Brazdil, Pavel, Jan N. van Rijn, Carlos Soares, and Joaquin Vanschoren. "Dataset Characteristics (Metafeatures)." In Metalearning, 53–75. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-67024-5_4.

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SummaryThis chapter discusses dataset characteristics that play a crucial role in many metalearning systems. Typically, they help to restrict the search in a given configuration space. The basic characteristic of the target variable, for instance, determines the choice of the right approach. If it is numeric, it suggests that a suitable regression algorithm should be used, while if it is categorical, a classification algorithm should be used instead. This chapter provides an overview of different types of dataset characteristics, which are sometimes also referred to as metafeatures. These are of different types, and include so-called simple, statistical, information-theoretic, model-based, complexitybased, and performance-based metafeatures. The last group of characteristics has the advantage that it can be easily defined in any domain. These characteristics include, for instance, sampling landmarkers representing the performance of particular algorithms on samples of data, relative landmarkers capturing differences or ratios of performance values and providing estimates of performance gains. The final part of this chapter discusses the specific dataset characteristics used in different machine learning tasks, including classification, regression, time series, and clustering.
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Singh, Rajesh, Florentin Smarandache, and Rohan Mishra. "Generalized robust-type neutrosophic ratio estimators of pharmaceutical daily stock prices." In Cognitive Intelligence with Neutrosophic Statistics in Bioinformatics, 417–29. Elsevier, 2023. http://dx.doi.org/10.1016/b978-0-323-99456-9.00019-2.

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Viada- Gonzalez, Carmen Elena, and Sira María Allende-Alonso. "Stratified Ranked Set Sampling (SRSS) for Estimating the Population Mean With Ratio-Type Imputation of the Missing Values." In Ranked Set Sampling Models and Methods, 141–70. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-7556-7.ch007.

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In this chapter, the authors develop stratified ranked set sampling (RSS) under missing observations. Imputation based of ratio rules is used for completing the information for estimating the mean. They introduce the needed elements on imputation and on the sample selection procedures. They extend RSS models to imputation in stratified populations. A theory on ratio-based imputation rules for estimating the mean is presented. Some numerical studies, based on real-world problems, are developed for illustrating the behaviour of the accuracy of the estimators due to their proposals.
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Vishwakarma, Gajendra K., Sayed Mohammed Zeeshan, and Carlos N. Bouza-Herrera. "Ratio and Product Type Exponential Estimators for Population Mean Using Ranked Set Sampling." In Ranked Set Sampling, 251–57. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-815044-3.00018-6.

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Bouza-Herrera, Carlos N., Jose M. Sautto, and Khalid Ul Islam Rather. "Ratio-Type Estimation Using Scrabled Auxiliary Variables in Stratification Under Simple Random Sampling and Ranked Set Sampling." In Ranked Set Sampling Models and Methods, 62–85. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-7556-7.ch004.

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This chapter introduced basic elements on stratified simple random sampling (SSRS) on ranked set sampling (RSS). The chapter extends Singh et al. results to sampling a stratified population. The mean squared error (MSE) is derived. SRS is used independently for selecting the samples from the strata. The chapter extends Singh et al. results under the RSS design. They are used for developing the estimation in a stratified population. RSS is used for drawing the samples independently from the strata. The bias and mean squared error (MSE) of the developed estimators are derived. A comparison between the biases and MSEs obtained for the sampling designs SRS and RSS is made. Under mild conditions the comparisons sustained that each RSS model is better than its SRS alternative.
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Kumar, Kamlesh, Sunit Kumar, and Anupam Kumar. "Study on Generalized Exponential Type Estimators for Ratio of Two Population Means Using Auxiliary Attribute in the Presence of Non-response." In Recent Advances in Mathematical Research and Computer Science Vol. 4, 31–41. Book Publisher International (a part of SCIENCEDOMAIN International), 2021. http://dx.doi.org/10.9734/bpi/ramrcs/v4/4664f.

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Singh, Rajesh, and Rohan Mishra. "Generalized Power Transformed Robust Ratio Type Estimator: An Application to COVID-19." In Research Highlights in Mathematics and Computer Science Vol. 4, 10–20. B P International (a part of SCIENCEDOMAIN International), 2023. http://dx.doi.org/10.9734/bpi/rhmcs/v4/4608e.

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Singer, Donald, and W. David Menzie. "Deposit-Density Models." In Quantitative Mineral Resource Assessments. Oxford University Press, 2010. http://dx.doi.org/10.1093/oso/9780195399592.003.0007.

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A key function of many forms of quantitative mineral resource assessments is estimation of the number of undiscovered deposits. In any given region, there is some fixed but, in most cases, unknown number of undiscovered deposits of a given type—the number could be zero or a larger integer. Many quantitative resource assessments that are based on a common three-part form of assessment (Singer, 1993a) have used expert judgment to estimate the number of deposits. Estimates of this unknown number are presented in a probabilistic form to reflect the uncertainty associated with the estimate. Ideally, estimates of number of deposits should rely on analogies with similar well-explored geologic settings, just as grades and tonnages of well explored deposits serve as analogs of the qualities and sizes of undiscovered deposits. Estimates of the number of undiscovered deposits can be derived from counts of known deposits per unit area in explored control regions. Number of deposits per unit area of the control regions can be used in histograms to show variation of densities by deposit type. Some research has been conducted on densities of several deposit types so that these ratios can be more widely used as a guide for number-of-deposit estimates (Bliss, Orris, and Menzie, 1987; Bliss, Menzie, Orris, and Page, 1987; Bliss and Menzie, 1993; Bliss, 1992b; Root, Menzie, and Scott, 1992). Most of these studies provide point (i.e., single) estimates of the number of deposits per unit area. Singer et al. (2001) summarize the ideas behind these mineral deposit density models and provide individual estimates for twenty-seven combinations of deposit types and control locations. Many of the specially selected areas they describe provide standards to identify what should be considered high estimates of number of undiscovered deposits in most situations. Thus, many published mineral-deposit densities provide guides that suggest upper limits to estimates but are not necessarily useful in providing estimation guides for more likely situations.
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Gajić, Darija, Erdin Salihović, and Nermina Zagora. "Estimate of Energy Performance Indicator of Existing Single-Family Houses in Bosnia and Herzegovina." In Advances in Civil and Industrial Engineering, 244–60. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-9932-6.ch012.

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Yielding from an overall quantitative study of the residential sector of Bosnia and Herzegovina (B&H), this chapter concentrates on the ratio between single-family and collective housing, as well as on the urban-rural ratio of the single-family housing. Based on the data from the existing building stock (buildings built by 2014) and the statistical estimates, 23% of the buildings belong to the urban areas and 77% belong to the rural areas. The main goal was to study the correlation between the characteristics of the building envelope, the shape factor (A/V ratio) and the energy savings potential for the application of conventional measures of refurbishment of the building envelope of the single-family houses (type of buildings, which dominate in rural and urban areas). The chapter wraps up with recommendations for the adequate level of the energy performance indicator (energy need for heating) for the approved energy class for single-family houses located in the climate zone of the northern B&H.
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Conference papers on the topic "Ratio Type Estimators"

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Sharma, Sumiti, and Sangeeta Malik. "Some improved quadratic ratio and product type linear regression estimators." In PROCEEDING OF INTERNATIONAL CONFERENCE ON FRONTIERS OF SCIENCE AND TECHNOLOGY 2021. AIP Publishing, 2022. http://dx.doi.org/10.1063/5.0115261.

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Zhang, Xiaodong, Remus C. Avram, Liang Tang, and Michael J. Roemer. "A Unified Nonlinear Approach to Fault Diagnosis of Aircraft Engines." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-95803.

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Many existing aircraft engine diagnostic methods are based on linearized engine models. However, the dynamics of aircraft engines are highly nonlinear and rapidly changing. Future engine health management designs will benefit from new methods that are directly based on intrinsic nonlinearities of the engine dynamics. In this paper, a fault detection and isolation (FDI) method is developed for aircraft engines by utilizing nonlinear adaptive estimation and nonlinear observer techniques. Engine sensor faults, actuator faults and component faults are considered under one unified nonlinear framework. The fault diagnosis architecture consists of a fault detection estimator and a bank of nonlinear fault isolation estimators. The fault detection estimator is used for detecting the occurrence of a fault, while the bank of fault isolation estimators is employed to determine the particular fault type or location after fault detection. Each isolation estimator is designed based on the functional structure of a particular fault type under consideration. Specifically, adaptive estimation techniques are used for designing the isolation estimators for engine component faults and actuator faults, while nonlinear observer techniques are used for designing the isolation estimators for sensor faults. The FDI architecture has been integrated with the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) engine model developed by NASA researchers in recent years. The engine model is a realistic representation of the nonlinear aero thermal dynamics of a 90,000-pound thrust class turbofan engine with high-bypass ratio and a two-spool configuration. Representative simulation results and comparative studies are shown to verify the effectiveness of the nonlinear FDI method.
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Pavlikov, V. V., A. V. Odokiyenko, and A. D. Sobkolov. "Comparison of dicke and ratio type modulation radiometers statistical characteristics of signal parameter estimates and fluctuation sensitivities." In 2017 IEEE Microwaves, Radar and Remote Sensing Symposium (MRRS). IEEE, 2017. http://dx.doi.org/10.1109/mrrs.2017.8075019.

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Alam, Md Jahangir, Douglas O'Shaughnessy, and Sid-Ahmed Selouani. "Speech enhancement employing a sigmoid -type gain function with a modified a priori signal-to-noise ratio (SNR) estimator." In 2008 Canadian Conference on Electrical and Computer Engineering - CCECE. IEEE, 2008. http://dx.doi.org/10.1109/ccece.2008.4564612.

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Hänninen, Henri, and Matti Pietola. "Analysis on the Adaptability of Two Different Hydraulic Energy Recovery Circuits on Various Machine Types and Work Cycles." In ASME/BATH 2013 Symposium on Fluid Power and Motion Control. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fpmc2013-4470.

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In the task of improving the energy efficiency of a work machine, the implementation of an energy recovery system is in many cases the most effective solution. Simulations and measurements on two distinctive hydraulic recovery circuit types, implemented on a reach truck test bench, have indicated clearly different performance profiles with different work cycle types. The first of the two systems is based on diverting the flow to be recovered directly to hydraulic accumulators utilizing a digital flow control unit. This system has been measured to exceed cyclic efficiency of 90 percent with optimal system settings in constant load scenarios. However, in mixed goods warehouses this efficiency can be significantly lower. The second recovery system, even though exhibiting slightly lower peak efficiency, has been measured to operate at relatively constant efficiency regardless of the work cycle type. This system is based on hydraulic transformer which varies the pressure/flow ratio in order to maximize the quantity of recovered energy. In this study these two systems are analyzed in terms of their adaptability to different fork lift types and to different work cycles. The assessment is carried out by analyzing typical machine specific operation cycles, comparing machine complexity versus recovery circuit complexity and by estimations of build costs versus gains.
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Momeni, Amir Farid, Robert J. Peterman, B. Terry Beck, and Chih-Hang John Wu. "Effect of Strand Indentation Types on the Development Length and Flexural Capacity of Concrete Railroad Ties Made With Different Prestressing Strands." In 2019 Joint Rail Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/jrc2019-1233.

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Pretensioned concrete prisms made with five different prestressing strand types (four 7-wire strands and one 3-wire strand) were load tested to failure to understand the effect of strand indentation types on the development length and bonding performance of these different reinforcements. The prestressing strands were denoted SA, SB, SD, SE and SF. SA was a smooth strand while the other four were indented strands. All strands utilized in manufacturing ofprisms had diameter of 3/8″ (9.52 mm). Among all types of strands, SF was the only 3-wire strand and the remaining strands were all 7-wire strands. For all types of strands, four straight strands were embedded into each concrete prism, which had a 5.5″ (139.7 mm) × 5.5″ (139.7 mm) square cross section. The strands were tensioned to 75 percent of ultimate tensile strength of strands and gradually de-tensioned when the concrete compressive strength reached 4500 psi (31.03 Mpa). A consistent concrete mixture with type III cement, water-cement ratio of 0.32 and a 6-in. slump was used for all prisms. Prisms were load tested in 3-point-bending at different embedment lengths to obtain estimations of the development length of each type of strand. Two out of three identical 69-in.-long (175.26 cm) prisms were load tested at one end and one was tested at both ends for each reinforcement type evaluated. First prisms were tested at 28-in. (71.12 cm) from the end, while second prisms were tested at 20-in. (33.02 cm) from the end. Third prisms were loaded at 16.5-in. (41.9 cm) from one end and 13-in. (33.02 cm) from the other end. Thus, a total of 20 load tests (5 strand types × 4 tests each) were conducted in this study. During each test, a concentrated load with the rate of 900 lb/min (4003 N/min) was applied at mid-span until failure occurred. Values of load, mid-span deflection, and strand endslip were continuously monitored and recorded during each test. Plots of load-vs-deflection were then compared for prisms with each strand type and span, and the maximum sustained moment was also calculated for each test. The load tests revealed that there is a large difference in the development length of the strands based on their indentation type.
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Momeni, Amir Farid, Robert J. Peterman, B. Terry Beck, Chih-Hang John Wu, and Naga Narendra B. Bodapati. "Effect of Prestressing Wire Indentation Type on the Development Length and Flexural Capacity of Pretensioned Concrete Crossties." In 2015 Joint Rail Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/jrc2015-5739.

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Load tests were conducted on pretensioned concrete prisms cast with 13 different 5.32-mm-diameter prestressing wire types that are used in the manufacture of pretensioned concrete railroad ties worldwide. The tests were specifically designed to evaluate the development length and bonding performance of these different reinforcements. The prestressing wires were denoted “WA” through “WM” and indentation types included smooth, spiral, chevron, diamond, and 2-dot and 4-dot. Four wires were embedded into each concrete prism, which had a 3.5″ (88.9 mm) × 3.5″ (88.9 mm) square cross section. The wires were initially tensioned to 7000 pounds (31.14 KN) and gradually de-tensioned when the concrete compressive strength reached 4500 psi (31.03 Mpa). A consistent concrete mixture with type III cement, water-cement ratio of 0.32 and a 6-in. slump was used for all prisms. Prisms were tested in 3-point-bending at different spans to obtain estimations of the development length of each type of reinforcement. Two identical 69-in.-long (175.26 cm) prisms were load tested, at both ends, for each reinforcement type evaluated. First prisms were tested at 20-in. (50.8 cm) from one end and 13-in. (33.02 cm) from the other end, whereas the second prisms were loaded at 16.5-in. (41.9 cm) from one end and 9.5-in. (24.13 cm) from the other end. Thus, a total of 52 load tests (13 wire types × 4 tests each) were conducted in this study. During each test, a concentrate load with the rate of 300 lb/min (1334 N/min) was applied at mid-span until failure occurred, and values of load, mid-span deflection, and wire end-slip were continuously monitored and recorded. Plots of load-vs-deflection were then compared for prisms with each wire type and span, and the maximum sustained moment was also calculated for each test. The load tests revealed that there is a very large difference in the development length of the different wire types currently used in the manufacture of pretensioned concrete railroad ties. The results imply that there would also likely be large differences in the reserve capacity (beyond first cracking) for pretensioned concrete crossties fabricated with these different reinforcements.
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Hage, Ilige S., Charbel Y. Seif, Ré-Mi Hage, and Ramsey F. Hamade. "A Verified Non-Linear Regression Model for Elastic Stiffness Estimates of Finite Composite Domains Considering Combined Effects of Volume Fractions, Shapes, Orientations, Locations, and Number of Multiple Inclusions." In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-86231.

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A non-linear regression model using SAS/STAT (JMP® software; Proc regression module) is developed for estimating the elastic stiffness of finite composite domains considering the combined effects of volume fractions, shapes, orientations, inclusion locations, and number of multiple inclusions. These estimates are compared to numerical solutions that utilized another developed homogenization methodology by the authors (dubbed the generalized stiffness formulation, GSF) to numerically determine the elastic stiffness tensor of a composite domain having multiple inclusions with various combinations of geometric attributes. For each inclusion, these considered variables represent the inclusions’ combined attributes of volume fraction, aspect ratio, orientation, number of inclusions, and their locations. The GSF methodology’s solutions were compared against literature-reported solutions of simple cases according to such well-known techniques as Mori-Tanaka and generalized self-consistent type methods. In these test cases, the effect of only one variable was considered at a time: volume fraction, aspect ratio, or orientation (omitting the number and locations of inclusions). For experimental corroboration of the numerical solutions, testing (uniaxial compression) was performed on test cases of 3D printed test cubes. The regression equation returns estimates of the composite’s ratio of normalized longitudinal modulus (E11) to that of the matrix modulus (Em) or E11/Em when considering any combination of all of the aforementioned inclusions’ variables. All parameters were statistically analyzed with the parameters retained are only those deemed statistically significant (p-values less than 0.05). Values returned by the regression stiffness formulation solutions were compared against values returned by the GSF formulation numerical and against the experimentally found stiffness values. Results show good agreement between the regression model estimates as compared with both numerical and experimental results.
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Poteat, Logan S., and M. Keith Sharp. "Solar Load Ratio Parameters for a Passive Solar Heat Pipe System." In ASME 2015 9th International Conference on Energy Sustainability collocated with the ASME 2015 Power Conference, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/es2015-49136.

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The Solar Load Ratio (SLR) method is a performance prediction algorithm for passive solar space heating systems developed at Los Alamos National Laboratory. Based on curve fits of detailed thermal simulations of buildings, the algorithm provides fast estimation of monthly solar savings fraction for direct gain, indirect gain (water wall and concrete wall) and sunspace systems of a range of designs. Parameters are not available for passive solar heat pipe systems, which are of the isolated gain type. While modern computers have increased the speed with which detailed simulations can be performed, the quick estimates generated by the SLR method are still useful for early building design comparisons and for educational purposes. With this in mind, the objective of this project was to develop SLR predictions for heat pipe systems, which use heat pipes for one-way transport of heat into the building. A previous thermal network was used to simulate the heat pipe system with Typical Meteorological Year (TMY3) weather data for 13 locations across the US, representing ranges of winter temperature and available sunshine. A range of (nonsolar) load-to-collector ratio LCR = 1–15 W/m2K was tested for each location. The thermal network, along with TMY3 data, provided monthly-average-daily absorbed solar radiation and building load to calculate SLR. Losses from the solar aperture in a heat pipe system are very low compared to conventional passive solar systems, thus the load-to-collector ratio of the solar aperture was neglected in these preliminary calculations. Likewise, nighttime insulation is unnecessary for a heat pipe system, and was not considered. An optimization routine was used to determine an exponential fit (the heart of the SLR method) to simulated monthly solar savings fraction (SSF) across all locations and LCR values. Accuracy of SSF predicted by SLR compared to the thermal network results was evaluated. The largest errors (up to 50%) occurred for months with small heating loads (< 80 K days), which inflated SSF. Limiting the optimization to the heating season (October to March), reduced the error in SSF to an average of 4.24% and a standard deviation of 5.87%. These results expand the applications of the SLR method to heat pipe systems, and allow building designers to use this method to estimate the thermal benefits of heat pipe systems along with conventional direct gain, indirect gain and sunspace systems.
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Petrovic, M. S., A. Suchocki, R. C. Powell, G. C. Valley, E. Cantwell, and J. Aldridge. "Picosecond Pulse-Probe, Two-beam Coupling, and Polarization Rotation Switching in Cadmium Telluride*." In Photorefractive Materials, Effects, and Devices II. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/pmed.1990.dp1.

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Laser-induced gratings produced by one- and two-photon absorption of picosecond pulses at 1.064 μm were used to examine the room temperature nonlinear optical responses of undoped n- and p-type CdTe crystals. We report what we believe to be the first observation of picosecond photorefractive two-beam coupling in a material that has no cw response. Gains up to 2.5 cm−1 were obtained at fluences of 120 mJ cm−2 for 0.8 μm grating spacing. Polarization rotation switching was also measured with on/off ratios of 6.0 at fluences of 56 mJ cm−2. Pulse- probe degenerate four-wave mixing measurements of grating dynamics on subnanosecond time scales were used to measure the ambipolar diffusion coefficient of charge carriers in the crystals. The value of Dα = 3.0 cm2 s−1 which was obtained is in very good agreement with theoretical estimates. Free carrier lifetimes of 12 ns were measured. A long-lived contribution to the signal consistent with a trapped charge photorefractive effect was observed at large grating spacings for n-type conductivity, and is tentatively attributed to a larger trap density in this sample. Measurements of the relative scattering efficiencies of successive diffracted orders in the Raman-Nath regime allowed for calculation of the laser-induced change in the index of refraction, Δn due to the creation of free carriers. The value of Δn = 4 x 10−4 which was obtained is in good agreement with theoretical estimates. *Research sponsored by DARPA contract MAD972-89-K0001.
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Reports on the topic "Ratio Type Estimators"

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Yu, Yipin, Duoting Tan, Dan Sheng, Liqin Zhong, Zhixi Hu, and Hao Liang. Neutrophil-to-lymphocyte ratio as a prognostic predictor for heart failure patients: a systematic review and meta-analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, March 2022. http://dx.doi.org/10.37766/inplasy2022.3.0062.

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Review question / Objective: This study aimed to evaluate the relationship between NLR and in-hospital or long-term prognosis of patients with heart failure by meta-analysis. Eligibility criteria: Inclusion criteria: (1) Patients with heart failure who underwent NLR measurement ;the study types were prospective cohort study or retrospective cohort study; and (3) risk estimates of association between NLR levels and heart failure related events occurring during hospital or follow-up were studied experimentally. Case reports, reviews, animal studies, conference proceedings, letters to editors, abstract only and duplicated studies were excluded.
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Tanny, Josef, Gabriel Katul, Shabtai Cohen, and Meir Teitel. Micrometeorological methods for inferring whole canopy evapotranspiration in large agricultural structures: measurements and modeling. United States Department of Agriculture, October 2015. http://dx.doi.org/10.32747/2015.7594402.bard.

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Original objectives and revisions The original objectives as stated in the approved proposal were: (1) To establish guidelines for the use of micrometeorological techniques as accurate, reliable and low-cost tools for continuous monitoring of whole canopy ET of common crops grown in large agricultural structures. (2) To adapt existing methods for protected cultivation environments. (3) To combine previously derived theoretical models of air flow and scalar fluxes in large agricultural structures (an outcome of our previous BARD project) with ET data derived from application of turbulent transport techniques for different crops and structure types. All the objectives have been successfully addressed. The study was focused on both screenhouses and naturally ventilated greenhouses, and all proposed methods were examined. Background to the topic Our previous BARD project established that the eddy covariance (EC) technique is suitable for whole canopy evapotranspiration measurements in large agricultural screenhouses. Nevertheless, the eddy covariance technique remains difficult to apply in the farm due to costs, operational complexity, and post-processing of data – thereby inviting alternative techniques to be developed. The subject of this project was: 1) the evaluation of four turbulent transport (TT) techniques, namely, Surface Renewal (SR), Flux-Variance (FV), Half-order Time Derivative (HTD) and Bowen Ratio (BR), whose instrumentation needs and operational demands are not as elaborate as the EC, to estimate evapotranspiration within large agricultural structures; and 2) the development of mathematical models able to predict water savings and account for the external environmental conditions, physiological properties of the plant, and structure properties as well as to evaluate the necessary micrometeorological conditions for utilizing the above turbulent transfer methods in such protected environments. Major conclusions and achievements The major conclusions are: (i) the SR and FV techniques were suitable for reliable estimates of ET in shading and insect-proof screenhouses; (ii) The BR technique was reliable in shading screenhouses; (iii) HTD provided reasonable results in the shading and insect proof screenhouses; (iv) Quality control analysis of the EC method showed that conditions in the shading and insect proof screenhouses were reasonable for flux measurements. However, in the plastic covered greenhouse energy balance closure was poor. Therefore, the alternative methods could not be analyzed in the greenhouse; (v) A multi-layered flux footprint model was developed for a ‘generic’ crop canopy situated within a protected environment such as a large screenhouse. The new model accounts for the vertically distributed sources and sinks within the canopy volume as well as for modifications introduced by the screen on the flow field and microenvironment. The effect of the screen on fetch as a function of its relative height above the canopy is then studied for the first time and compared to the case where the screen is absent. The model calculations agreed with field experiments based on EC measurements from two screenhouse experiments. Implications, both scientific and agricultural The study established for the first time, both experimentally and theoretically, the use of four simple TT techniques for ET estimates within large agricultural screenhouses. Such measurements, along with reliable theoretical models, will enable the future development of lowcost ET monitoring system which will be attainable for day-to-day use by growers in improving irrigation management.
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