Relevant bibliographies by topics / Single Stage Sampling

Academic literature on the topic 'Single Stage Sampling'

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Published: 8 September 2023

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Journal articles on the topic "Single Stage Sampling"

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Boistard, Hélène, Hendrik P. Lopuhaä, and Anne Ruiz-Gazen. "Functional central limit theorems for single-stage sampling designs." Annals of Statistics 45, no. 4 (August 2017): 1728–58. http://dx.doi.org/10.1214/16-aos1507.

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Overall, John E., and Robert S. Atlas. "Comparison of a Two-Stage and Three-Stage Interim-Analysis Procedure." Psychological Reports 71, no. 1 (August 1992): 3–14. http://dx.doi.org/10.2466/pr0.1992.71.1.3.

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A statistical model for combining p values from multiple tests of significance is used to define rejection and acceptance regions for two-stage and three-stage sampling plans. Type I error rates, power, frequencies of early termination decisions, and expected sample sizes are compared. Both the two-stage and three-stage procedures provide appropriate protection against Type I errors. The two-stage sampling plan with its single interim analysis entails minimal loss in power and provides substantial reduction in expected sample size as compared with a conventional single end-of-study test of significance for which power is in the adequate range. The three-stage sampling plan with its two interim analyses introduces somewhat greater reduction in power, but it compensates with greater reduction in expected sample size. Either interim-analysis strategy is more efficient than a single end-of-study analysis in terms of power per unit of sample size.
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Qian, Hanxiang, Peng Wu, Bei Sun, and Shaojing Su. "AGS-SSD: Attention-Guided Sampling for 3D Single-Stage Detector." Electronics 11, no. 14 (July 20, 2022): 2268. http://dx.doi.org/10.3390/electronics11142268.

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3D object detection based on LiDAR point cloud has always been challenging. Existing point cloud downsampling approaches often use heuristic algorithms such as farthest point sampling (FPS) to extract the features from a massive raw point cloud. However, FPS has disadvantages such as low operating efficiency and inability to sample key areas. This paper presents an attention-guided downsampling method for point-cloud-based 3D object detection, named AGS-SSD. The method contains two modules: PEA (point external attention) and A-FPS (attention-guided FPS). PEA explores the correlation between the data and uses the external attention mechanism to extract the semantic features in the set abstraction stage. The semantic information, including the relationship between the samples, is sent to the candidate point generation module as context points. A-FPS weighs the point cloud according to the generated attention map and samples the foreground points with rich semantic information as candidate points. The experimental results show that our method achieves significant improvements with novel architectures against the baseline and runs at 24 frames per second for inference.
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JONES, WILLIAM, KATHY MORRING, PHILIP MOREY, and WILLIAM SORENSON. "Evaluation of the Andersen Viable Impactor for Single Stage Sampling." American Industrial Hygiene Association Journal 46, no. 5 (May 1, 1985): 294–98. http://dx.doi.org/10.1080/15298668591394833.

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Hoogduin, Lucas A., Thomas W. Hall, and Jeffrey J. Tsay. "Modified Sieve Sampling: A Method for Single- and Multi-Stage Probability- Proportional-to-Size Sampling." AUDITING: A Journal of Practice & Theory 29, no. 1 (May 1, 2010): 125–48. http://dx.doi.org/10.2308/aud.2010.29.1.125.

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SUMMARY: Widely used probability-proportional-to-size (PPS) selection methods are not well adapted to circumstances requiring sample augmentation. Limitations include: (1) an inability to augment selections while maintaining PPS properties, (2) a failure to recognize changes in census stratum membership which result from sample augmentation, and (3) imprecise control over line item sample size. This paper presents a new method of PPS selection, a modified version of sieve sampling which overcomes these limitations. Simulations indicate the new method effectively maintains sampling stratum PPS properties in single- and multi-stage samples, appropriately recognizes changes in census stratum membership which result from sample augmentation, and provides precise control over line item sample sizes. In single-stage applications the method provides reliable control of sampling risk over varied tainting levels and error bunching patterns. Tightness and efficiency measures are comparable to randomized systematic sampling and superior to sieve sampling.
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Wen, Miin-Jye, Li-Ching Huang, and Junjiang Zhong. "Single-stage sampling procedure of the t best populations under heteroscedasticity." Communications in Statistics - Theory and Methods 46, no. 18 (June 2, 2017): 9265–73. http://dx.doi.org/10.1080/03610926.2016.1206935.

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Thunyasirinon, Chuleewan, Pipat Sribenjalux, and Paradee Chuaybamroong. "Comparison of a Six-Stage and a Single Stage Viable Andersen Impactor (N6) for Airborne Microbe Sampling." Khon Kaen University Journal (Graduate Studies) 07, no. 3 (July 1, 2007): 107–17. http://dx.doi.org/10.5481/kkujgs.2007.07.3.11.

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Chen, Demin, Wei Long, Yanyan Li, and Rui Zhang. "Study on Change Rules of Factors Affecting Gas Loss during Coalbed Air Reverse Circulation Sampling." Advances in Civil Engineering 2021 (April 20, 2021): 1–15. http://dx.doi.org/10.1155/2021/5550726.

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The gas loss in sampling is the root of coalbed gas content measurement error. The pressure and particle size have a significant impact on the gas loss. Using the self-developed coal particle pneumatic pipeline transportation experimental system, this study investigated the pressure and particle size changes in the sampling pipeline. It is found that the sampling process can be divided into four stages: no flow field stage, sample outburst stage, stable conveying stage, and tail purging stage. The extreme pressure in the sampling pipeline appears at the sample outburst stage; and the pressure in the pipeline has levelled off after sharp decrease in the stable conveying stage. It is also found that the extreme pressure increases first and then decreases with the increase of particle size. The duration of outburst stage is negatively correlated with particle size, and that of stable conveying stage is positively correlated with particle size. In addition, the results show that the loss rate of 1–3 mm particles is the smallest after the test but that particles less than 1 mm increase by about two times and particles greater than 3 mm decrease by more than three times. The study also shows that the particle size distribution of coal samples is a single peak with left skew distribution, and the gas reverse circulation sampling test does not change the location of the peak but makes it higher and sharper. The single size coal sample is more likely to collide than the mixture. This study can help to advance the understanding of impact factors on gas loss during reverse circulation sampling.
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Valliant, Richard. "Some Prediction Properties of Balanced Half-Sample Variance Estimators in Single-Stage Sampling." Journal of the Royal Statistical Society: Series B (Methodological) 49, no. 1 (September 1987): 68–81. http://dx.doi.org/10.1111/j.2517-6161.1987.tb01427.x.

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Temesgen, H. "Evaluation of sampling alternatives to quantify tree leaf area." Canadian Journal of Forest Research 33, no. 1 (January 1, 2003): 82–95. http://dx.doi.org/10.1139/x02-159.

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High within- and among-tree crown variation have contributed to the difficulty of tree-crown sampling and single-tree leaf area (area available for photosynthesis) estimation. Using reconstructed trees, simulations were used to compare five sampling designs for bias, mean square error (MSE), and distribution of the estimates. All sampling designs showed nearly zero bias. For most sample trees, stratified random sampling resulted in the lowest MSE values, followed by ellipsoidal, two-stage systematic, simple random, and then by two-stage unequal probability sampling. The poor performance of two-stage unequal probability sampling can be ascribed to the unequal probability of inclusion of first-order branches and twigs.
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Dissertations / Theses on the topic "Single Stage Sampling"

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Agnew, Robert J. "Assessment of the variablity of indoor viable airborne mold sampling using the Anderson N-6 single stage impactor." Oklahoma City : [s.n.], 2002. http://library.ouhsc.edu/epub/theses/Agnew-Robert-J.pdf.

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Bryan, Paul David. "Accelerating microarchitectural simulation via statistical sampling principles." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47715.

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The design and evaluation of computer systems rely heavily upon simulation. Simulation is also a major bottleneck in the iterative design process. Applications that may be executed natively on physical systems in a matter of minutes may take weeks or months to simulate. As designs incorporate increasingly higher numbers of processor cores, it is expected the times required to simulate future systems will become an even greater issue. Simulation exhibits a tradeoff between speed and accuracy. By basing experimental procedures upon known statistical methods, the simulation of systems may be dramatically accelerated while retaining reliable methods to estimate error. This thesis focuses on the acceleration of simulation through statistical processes. The first two techniques discussed in this thesis focus on accelerating single-threaded simulation via cluster sampling. Cluster sampling extracts multiple groups of contiguous population elements to form a sample. This thesis introduces techniques to reduce sampling and non-sampling bias components, which must be reduced for sample measurements to be reliable. Non-sampling bias is reduced through the Reverse State Reconstruction algorithm, which removes ineffectual instructions from the skipped instruction stream between simulated clusters. Sampling bias is reduced via the Single Pass Sampling Regimen Design Process, which guides the user towards selected representative sampling regimens. Unfortunately, the extension of cluster sampling to include multi-threaded architectures is non-trivial and raises many interesting challenges. Overcoming these challenges will be discussed. This thesis also introduces thread skew, a useful metric that quantitatively measures the non-sampling bias associated with divergent thread progressions at the beginning of a sampling unit. Finally, the Barrier Interval Simulation method is discussed as a technique to dramatically decrease the simulation times of certain classes of multi-threaded programs. It segments a program into discrete intervals, separated by barriers, which are leveraged to avoid many of the challenges that prevent multi-threaded sampling.
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Vestin, Albin, and Gustav Strandberg. "Evaluation of Target Tracking Using Multiple Sensors and Non-Causal Algorithms." Thesis, Linköpings universitet, Reglerteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-160020.

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Today, the main research field for the automotive industry is to find solutions for active safety. In order to perceive the surrounding environment, tracking nearby traffic objects plays an important role. Validation of the tracking performance is often done in staged traffic scenarios, where additional sensors, mounted on the vehicles, are used to obtain their true positions and velocities. The difficulty of evaluating the tracking performance complicates its development. An alternative approach studied in this thesis, is to record sequences and use non-causal algorithms, such as smoothing, instead of filtering to estimate the true target states. With this method, validation data for online, causal, target tracking algorithms can be obtained for all traffic scenarios without the need of extra sensors. We investigate how non-causal algorithms affects the target tracking performance using multiple sensors and dynamic models of different complexity. This is done to evaluate real-time methods against estimates obtained from non-causal filtering. Two different measurement units, a monocular camera and a LIDAR sensor, and two dynamic models are evaluated and compared using both causal and non-causal methods. The system is tested in two single object scenarios where ground truth is available and in three multi object scenarios without ground truth. Results from the two single object scenarios shows that tracking using only a monocular camera performs poorly since it is unable to measure the distance to objects. Here, a complementary LIDAR sensor improves the tracking performance significantly. The dynamic models are shown to have a small impact on the tracking performance, while the non-causal application gives a distinct improvement when tracking objects at large distances. Since the sequence can be reversed, the non-causal estimates are propagated from more certain states when the target is closer to the ego vehicle. For multiple object tracking, we find that correct associations between measurements and tracks are crucial for improving the tracking performance with non-causal algorithms.
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Book chapters on the topic "Single Stage Sampling"

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Wu, Changbao, and Mary E. Thompson. "Simple Single-Stage Sampling Methods." In ICSA Book Series in Statistics, 17–31. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44246-0_2.

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de Vries, Pieter G. "Single- and More-Stage Cluster Sampling." In Sampling Theory for Forest Inventory, 161–82. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-71581-5_8.

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de Vries, Pieter G. "Single-Stage Cluster Sampling as a Research Tool." In Sampling Theory for Forest Inventory, 183–203. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-71581-5_9.

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Ilieva, Nevena, Jiaojiao Liu, Xubiao Peng, Jianfeng He, Antti Niemi, Peicho Petkov, and Leandar Litov. "Sampling in In Silico Biomolecular Studies: Single-Stage Experiments vs Multiscale Approaches." In Large-Scale Scientific Computing, 507–15. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73441-5_56.

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Dawar, Kshitij, Sanjay Srinivasan, and Mort D. Webster. "Application of Reinforcement Learning for Well Location Optimization." In Springer Proceedings in Earth and Environmental Sciences, 81–110. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-19845-8_7.

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AbstractThe extensive deployment of sensors in oilfield operation and management has led to the collection of vast amounts of data, which in turn has enabled the use of machine learning models to improve decision-making. One of the prime applications of data-based decision-making is the identification of optimum well locations for hydrocarbon recovery. This task is made difficult by the relative lack of high-fidelity data regarding the subsurface to develop precise models in support of decision-making. Each well placement decision not only affects eventual recovery but also the decisions affecting future wells. Hence, there exists a tradeoff between recovery maximization and information gain. Existing methodologies for placement of wells during the early phases of reservoir development fail to take an abiding view of maximizing reservoir profitability, instead focusing on short-term gains. While improvements in drilling technologies have dramatically lowered the costs of producing hydrocarbon from prospects and resulted in very efficient drilling operations, these advancements have led to sub-optimal and haphazard placement of wells. This can lead to considerable number of unprofitable wells being drilled which, during periods of low oil and gas prices, can be detrimental for a company’s solvency. The goal of the research is to present a methodology that builds machine learning models, integrating geostatistics and reservoir flow dynamics, to determine optimum future well locations for maximizing reservoir recovery. A deep reinforcement learning (DRL) framework has been proposed to address the issue of long-horizon decision-making. The DRL reservoir agent employs intelligent sampling and utilizes a reward framework that is based on geostatistical and flow simulations. The implemented approach provides opportunities to insert expert information while basing well placement decisions on data collected from seismic data and prior well tests. Effects of prior information on the well placement decisions are explored and the developed DRL derived policies are compared to single-stage optimization methods for reservoir development. Under similar reward framework, sequential well placement strategies developed using DRL have been shown to perform better than simultaneous drilling of several wells.
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Castillo-Santiago, Miguel Ángel, Edith Mondragón-Vázquez, and Roberto Domínguez-Vera. "Sample Data for Thematic Accuracy Assessment in QGIS." In Land Use Cover Datasets and Validation Tools, 85–96. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-90998-7_6.

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AbstractWe present an approach that is widely used in the field of remote sensing for the validation of single LUC maps. Unlike other chapters in this book, where maps are validated by comparison with other maps with better resolution and/or quality, this approach requires a ground sample dataset, i.e. a set of sites where LUC can be observed in the field or interpreted from high-resolution imagery. Map error is assessed using techniques based on statistical sampling. In general terms, in this approach, the accuracy of single LUC maps is assessed by comparing the thematic map against the reference data and measuring the agreement between the two. When assessing thematic accuracy, three stages can be identified: the design of the sample, the design of the response, and the estimation and analysis protocols. Sample design refers to the protocols used to define the characteristics of the sampling sites, including sample size and distribution, which can be random or systematic. Response design involves establishing the characteristics of the reference data, such as the size of the spatial assessment units, the sources from which the reference data will be obtained, and the criteria for assigning labels to spatial units. Finally, the estimation and analysis protocols include the procedures applied to the reference data to calculate accuracy indices, such as user’s and producer’s accuracy, the estimated areas covered by each category and their respective confidence intervals. This chapter has two sections in which we present a couple of exercises relating to sampling and response design; the sample size will be calculated, the distribution of sampling sites will be obtained using a stratified random scheme, and finally, a set of reference data will be obtained by photointerpretation at the sampling sites (spatial units). The accuracy statistics will be calculated later in Sect. 5 in chapter “Metrics Based on a Cross-Tabulation Matrix to Validate Land Use Cover Maps” as part of the cross-tabulation exercises. The exercises in this chapter use fine-scale LUC maps obtained for the municipality of Marqués de Comillas in Chiapas, Mexico.
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Neves, Claudia Mara Sperandio, João Felipe Coimbra Leite Costa, Leonardo Souza, Fernando Guimaraes, and Geraldo Dias. "Methodology for Defining the Optimal Drilling Grid in a Laterite Nickel Deposit Based on a Conditional Simulation." In Springer Proceedings in Earth and Environmental Sciences, 151–62. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-19845-8_13.

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AbstractIn mining projects, the confidence in an estimate is associated with the quantity and quality of the available information. Thus, the closer the data to the targeted location, the smaller the error associated with the estimated value. In the advanced stages of a project (i.e. the pre-feasibility and feasibility phases), it is usual to take samples derived from drillings. Since sampling and chemical analysis involve high costs, it is essential that these costs contribute to a reduction in the uncertainty of estimation. This paper presents a workflow for a case study of a lateritic nickel deposit and proposes a methodology to address the issue of optimising the drilling grid based on uncertainty derived from Gaussian conditional geostatistical simulations. The usefulness of the proposed workflow is demonstrated in terms of saving time and money when selecting a drill hole grid.
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Hankin, David G., Michael S. Mohr, and Ken B. Newman. "Single-stage cluster sampling: Clusters of equal size." In Sampling Theory, 92–103. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198815792.003.0006.

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Similar to strata, population units may instead be grouped into clusters. Usually, units within clusters are geographically or genetically close to one another—all households on a city block, individuals within a single family. In (single-stage) equal size cluster sampling, the total population consists of N clusters, with equal numbers of population units within each cluster. A sample of n clusters is selected by SRS, y values of all population units within clusters are measured, and an unbiased estimator of the population mean is the simple average of cluster means in the sample. An ANOVA sum of squares partition can be used to show that this strategy will outperform SRS with mean-per-unit estimation whenever the mean square between clusters is less than the finite population variance. This means that it is desirable for clusters to have similar means but a great deal of variability within clusters, a contrast with the desirable characteristics of strata (little variability within strata, substantial difference between stratum means). Many methods of collection of samples in fisheries (seines, nets) and wildlife (mist nets, live traps) involve collection of individuals as clusters. Unfortunately, clusters (e.g., human families) often consist of closely related or similar individuals. Because within cluster variation is often relatively low, it is often advantageous and cost-effective to instead adopt two-stage cluster sampling (considered in Chapter 9) for which only a sample of units within each selected cluster are examined, thereby allowing more clusters to be examined for the same total survey cost.
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"Self-weighting Designs in Stratified Single-stage Sampling." In Practical Sampling Techniques, 257–60. CRC Press, 1995. http://dx.doi.org/10.1201/9781482273465-26.

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Godambe, V. P., and M. E. Thompson. "5 On single stage unequal probability sampling." In Handbook of Statistics, 111–23. Elsevier, 1988. http://dx.doi.org/10.1016/s0169-7161(88)06007-9.

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Conference papers on the topic "Single Stage Sampling"

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Ajorlou, S., and A. Ajorlou. "A fuzzy-based design procedure for a single-stage sampling plan." In 2009 IEEE International Conference on Fuzzy Systems (FUZZ-IEEE). IEEE, 2009. http://dx.doi.org/10.1109/fuzzy.2009.5277316.

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van Beek, Anton, Siyu Tao, and Wei Chen. "Global Emulation Through Normative Decision Making and Thrifty Adaptive Batch Sampling." In ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-98223.

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Abstract We consider the problem of adaptive sampling for global emulation (metamodeling) with a finite budget. Conventionally this problem is tackled through a greedy sampling strategy, which is optimal for taking either a single sample or a handful of samples at a single sampling stage but neglects the influence of future samples. This raises the question: “Can we optimize the number of sampling stages as well as the number of samples at each stage?” The proposed thrifty adaptive batch sampling (TABS) approach addresses this challenge by adopting a normative decision-making perspective to determine the total number of required samples and maximize a multistage reward function with respect to the total number of stages and the batch size at each stage. To amend TABS’ numerical complexity we propose two heuristic-based strategies that significantly reduce computational time with minimal reduction of reward optimality. Through numerical examples, TABS is shown to outperform or at least be comparable to conventional greedy sampling techniques. In this fashion, TABS provides modelers a flexible adaptive sampling tool for global emulation, effectively reducing computational cost while maintaining prediction accuracy.
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Ribeiro, Hugo, Fernando Silva, Sonia Pinto, and Beatriz Borges. "Single stage inverter for PV applications with One Cycle Sampling technique in the MPPT algorithm." In IECON 2009 - 35th Annual Conference of IEEE Industrial Electronics (IECON 2009). IEEE, 2009. http://dx.doi.org/10.1109/iecon.2009.5415029.

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Romero, David A., Cristina H. Amon, and Susan Finger. "On Adaptive Sampling for Single and Multi-Response Bayesian Surrogate Models." In ASME 2006 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/detc2006-99210.

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In order to reduce the time and resources devoted to design-space exploration during simulation-based design and optimization, the use of surrogate models, or metamodels, has been proposed in the literature. Key to the success of metamodeling efforts are the experimental design techniques used to generate the combinations of input variables at which the computer experiments are conducted. Several adaptive sampling techniques have been proposed to tailor the experimental designs to the specific application at hand, using the already-acquired data to guide further exploration of the input space, instead of using a fixed sampling scheme defined a priori. Though mixed results have been reported, it has been argued that adaptive sampling techniques can be more efficient, yielding better surrogate models with less sampling points. In this paper, we address the problem of adaptive sampling for single and multi-response metamodels, with a focus on Multi-stage Multi-response Bayesian Surrogate Models (MMBSM). We compare distance-optimal latin hypercube sampling, an entropy-based criterion and the maximum cross-validation variance criterion, originally proposed for one-dimensional output spaces and implemented in this paper for multi-dimensional output spaces. Our results indicate that, both for single and multi-response surrogate models, the entropy-based adaptive sampling approach leads to models that are more robust to the initial experimental design and at least as accurate (or better) when compared with other sampling techniques using the same number of sampling points.
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Biela, Christoph, Martin W. Mu¨ller, Heinz-Peter Schiffer, and Carsten Zscherp. "Unsteady Pressure Measurement in a Single Stage Axial Transonic Compressor Near the Stability Limit." In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50245.

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With the help of piezoelectric high frequency pressure probes measurements are undertaken to investigate the flow during stable compressor operation close to the stability limit. Fourteen static pressure probes record the static wall pressure and ten total pressure probes record the total pressure at the rotor exit, both in the absolute frame of reference. The data is then visualised as ensemble averaged contour and spectrum plots. With the help of wall and exit pressure, the tip leakage vortex is localised. Oscillations of the tip leakage vortex are seen as well in terms of high relative standard deviation as well as in an excitation of a frequency band around 1/2 BPF. Further investigation of the frequency spectrum with the help of the pseudo-unsteady wall pressure reveal the occurrence of rotating tip leakage vortex disturbances forming a two-passage periodic vortex pattern. The presented measurements were obtained using Rotor-1 from the TU Darmstadt rotor family. With a sampling rate of 125kHz the pressure field is resolved with 23 measurements per passage (at 20.000 rpm, design speed).
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Chilla, M., G. Pullan, and S. Gallimore. "Reducing Instrumentation Errors Caused by Circumferential Flow Field Variations in Multi-Stage Axial Compressors." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90839.

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Abstract The effects of blade row interactions on stator-mounted instrumentation in axial compressors are investigated using unsteady numerical calculations. The test compressor is an 8-stage machine representative of an aero-engine core compressor. For the unsteady calculations, a 180deg sector (half-annulus) model of the compressor is used. It is shown that the time-mean flow field in the stator leading edge planes is circumferentially non-uniform. The circumferential variations in stagnation pressure and stagnation temperature respectively reach 4.2% and 1.1% of the local mean. Using spatial wave number analysis, the incoming wakes from the upstream stator rows are identified as the dominant source of the circumferential variations in the front and middle of the compressor, while towards the rear of the compressor, the upstream influence of the eight struts in the exit duct becomes dominant. Based on three circumferential probes, the sampling errors for stagnation pressure and stagnation temperature are calculated as a function of the probe locations. Optimization of the probe locations shows that the sampling error can be reduced by up to 77% by circumferentially redistributing the individual probes. The reductions in the sampling errors translate to reductions in the uncertainties of the overall compressor efficiency and inlet flow capacity by up to 50%. Recognizing that data from large-scale unsteady calculations is rarely available in the instrumentation phase for a new test rig or engine, a method for approximating the circumferential variations with single harmonics is presented. The construction of the harmonics is based solely on the knowledge of the number of stators in each row and a small number of equi-spaced probes. It is shown how excursions in the sampling error are reduced by increasing the number of circumferential probes.
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Jordan, Steven P., Martin R. Bache, Christopher D. Newton, and Louise Gale. "Characterisation of SiCf/SiC Specimens Using an In-Situ Tensile Stage Within a Scanning Electron Microscope." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90356.

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Abstract The present paper will introduce the use of scanning electron microscope based, in-situ tensile testing as a method of detecting cracking in a SiCf/SiC CMC at room temperature. Small scale tensile specimens were prepared, but still sampling multiple longitudinal and transverse fibre tows. Monotonic loading was applied to initiate cracking, whilst contemporary time lapse imaging and retrospective digital image correlation recorded the development of these cracks at the specimen surface. Examples of strain localization, crack initiation and propagation will be presented for a plain gauge section specimen and single edge notched specimen. The critical combination of SEM imaging together with real time loading, in order to identify microscopic cracking in this CMC system, will be demonstrated.
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Mu¨ller, Martin W., Christoph Biela, Heinz-Peter Schiffer, and Chunill Hah. "Interaction of Rotor and Casing Treatment Flow in an Axial Single-Stage Transonic Compressor With Circumferential Grooves." In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50135.

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The influence of circumferential grooves on the tip flow field of an axial single-stage transonic compressor rotor has been examined experimentally and numerically. The compressor stage provides a strongly increased stall margin with only small penalties in efficiency when the casing treatment is applied. Due to the complex interactions of the grooves with the rotor flow, unsteady measurement techniques have been chosen as an attempt to identify the aerodynamic effects responsible for the operating range extension. Therefore, the casing treatment has been instrumented with piezoresistive pressure sensors in the land between the grooves providing high-resolution static wall pressure measurements at different operating conditions. Data acquisition worked at a sampling rate of 125kHz, providing around 23 static pressure values per blade passage at 11 axial positions at the nominal speed of 20,000 rpm. A comparable dataset, but with 14 sensors, was obtained for the smooth casing. The results show the fluctuation of the tip leakage vortex and shock-vortex-interactions as well as the changed situation with casing treatment. Ensemble-averaged data shows tip leakage vortex trajectories. At near stall conditions with the smooth casing, the vortex hits the front part of the adjacent blade, which indicates the possibility of a spill forward of low momentum fluid into the next passage. Standard deviation values prove a high fluctuation of the pressure field over the tip gap. When the casing treatment is applied, the vortex trajectory maintains alignment along the blade’s suction side, thus preventing the onset of rotating stall. Results are presented as a back-to-back comparison of the smooth casing versus the treated casing at three operating conditions: peak efficiency at a mass flow rate of m˙pe = 16.2kg/s, near stall of the smooth casing at m˙nssc = 14.0kg/s and near stall of the treated casing at m˙ns = 12.6kg/s. Steady and unsteady numerical simulations of the rotor-only flow field have been calculated with and without grooves. These calculations aim at a broad analysis of the occurring flow phenomena at the rotor tip. Tip leakage flow behaviour and vortex trajectories are discussed in detail by summarizing the congruent findings of both numerical and experimental investigations.
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Olawoyin, Abdul-Akeem, and Rami M. Younis. "Learning to Solve Parameterized Single-Cell Problems Offline to Expedite Reservoir Simulation." In SPE Reservoir Simulation Conference. SPE, 2023. http://dx.doi.org/10.2118/212175-ms.

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Abstract The reservoir simulation system of residual equations is composed by applying a single parameterized nonlinear function to each cell in a mesh. This function depends on the unknown state variables in that cell as well as on those in the neighboring cells. Anecdotally, the solution of these systems relies on both the level of nonlinearity of this single-cell function as well as on how tightly the cell equations are coupled. This work reformulates this system of equations in an equivalent that is only mildly nonlinear. In an amortized offline regression stage, the single-cell equation is solved over a sampling of possible neighboring states and parameters. A neural network is regressed to this data. An equivalent residual system is formed by replacing the single-cell residual function with the neural network, and we propose three alternative algorithms to solve these preconditioned systems. The first method applies a Picard iteration that does not require Jacobian matrix evaluations or linear solution. The second applies a modified Seidel iteration that additionally infers locality automatically. The third algorithm applies Newton's method to the preconditioned system. The solvers are applied to a one-dimensional incompressible two-phase displacement problem with capillarity and a general two-dimensional two-phase flow model. We investigate the impacts of neural network regression accuracy on the performance of all methods. Reported performance metrics include the number of residual/network evaluations, linear solution iterations, and scalability with time step size. In all cases, the proposed methods significantly improve computational performance relative to the use of standard Newton-based solution methods.
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Chang, Yuhe, and Sean B. Andersson. "Observer-Based Control of a Dual-Stage Piezoelectric Scanner." In ASME 2019 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/dscc2019-9163.

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Abstract Despite its proven success in a wide variety of applications, the atomic force microscope (AFM) remains limited by its slow imaging rate. One approach to overcome this challenge is to rely on algorithmic approaches that reduce the imaging time not by scanning faster but by scanning less. Such schemes are particularly useful on older instruments as they can provide significant gains despite the existing (slow) hardware. At the same time, algorithms for sub-sampling can yield even greater improvements in imaging rate when combined with advanced scanners that can be retrofitted into the system. In this work, we focus on the use of a dual-stage piezoelectric scanner coupled with a particular scanning algorithm known as Local Circular Scan (LCS). LCS drives the tip of the AFM along a circular trajectory while using feedback to center that circle on a sample edge and to move the circle along the feature, thus reducing imaging time by concentrating the samples to the region of interest. Dual-stage systems are well-suited to LCS as the algorithm is naturally described in terms of a high-frequency, short range path (the scanning circle) and a slower, long range path (the track along the sample). However, control of the scanner is not straightforward as the system is multi-input, single-output. Here we establish controllability and observability of the scanning stage, allowing us to develop individual controllers for the long-range and short-range actuators through the principle of separation. We then use an internal model controller for the short range actuator to track a sinusoidal input (to generate the circular motion) and a state-space set-point tracking controller for the long range actuator. The results are demonstrated through simulation.
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Reports on the topic "Single Stage Sampling"

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Conrad, R., M. Childs, C. Rivera-Dirks, and F. Coriz. Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 1993. Office of Scientific and Technical Information (OSTI), July 1995. http://dx.doi.org/10.2172/92036.

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Childs, M., and R. Conrad. Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 95. Progress report. Office of Scientific and Technical Information (OSTI), September 1997. http://dx.doi.org/10.2172/555425.

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Conrad, R., M. Childs, C. R. Lyons, and F. Coriz. Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 94, Group ESH-19. Progress report. Office of Scientific and Technical Information (OSTI), August 1996. http://dx.doi.org/10.2172/378844.

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Marquis Childs and Ron Conrad. Area G Perimeter Surface-Soil and Single-Stage Water Sampling: Environmental Surveillance for Fiscal Years 1996 and 1997, Group ESH-19. Office of Scientific and Technical Information (OSTI), October 1998. http://dx.doi.org/10.2172/1242.

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Reid, M. S., X. Wang, N. Utting, and C. Jiang. Comparison of water chemistry of hydraulic-fracturing flowback water from two geological locations at the Duvernay Formation, Alberta, Canada. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/329276.

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We analyzed and compared the water chemistry between 17 Fox Creek region samples, each from a different well, and 23 Three Hills region samples from a single well. Overall, the two regions were similar in chemical composition but showed small differences in some lower abundance dissolved elements. Additionally, we investigated changes in water chemistry of FPW over time from a single well. The majority of water quality parameters and water chemistry remained constant over the 7-month sampling time. Major ion chemistry showed increasing concentrations of Ca and Mg, and a decreasing concentration of SO4. Several trace elements also showed small trends of both increasing and decreasing concentrations over time. There was a strong correlation between Ca and Mg concentrations in both the Fox Creek region samples and Three Hills region samples, which is an indication of the mixing of formation water. However, the correlation between B and Sr was different among two region samples, which is likely due to the delayed mixing of formation water with the fracturing fluids during the flowback at different time periods of post fracturing. Likewise, Fox Creek region samples showed correlations between concentrations of Cl and Ca, Na and Ca, and Na and Mg, but these correlations were not seen in the Three Hills region samples. Geochemical modeling demonstrates that there are potential scales formed in the flowback water, but most of the minerals are still in the dissolution state in the formation. Stable isotopic analysis confirmed the mixing of injection water and the formation water.
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Harter, Rachel M., Joseph P. McMichael, Derick S. Brown, Ashley Amaya, Trent D. Buskirk, and David Malarek. Telephone Appends for Address-Based Samples— An Introduction. RTI Press, February 2018. http://dx.doi.org/10.3768/rtipress.2018.op.0050.1802.

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Surveys with samples selected from an address frame derived from US Postal Service sources are often referred to as address-based sampling (ABS) surveys. For an ABS survey that is primarily conducted by mail, web, or face-to-face, sometimes it is helpful to have a telephone number corresponding to the sample addresses for setting appointments or conducting nonresponse follow-up prompts. The usefulness of a telephone contact mode in a mixed mode ABS design depends on both the percentage of addresses for which telephone numbers can be appended (append rate or match rate) and the accuracy of the telephone numbers associated with addresses. Before planning a telephone contact as part of a mixed-mode study, the designer should know the likely effectiveness of the approach. This paper focuses primarily on append rate information, with a discussion of accuracy rates. For a single ABS frame, telephone match rates vary by geography, address type, match vendor, and by landline vs. cell telephone number. Using very large samples of addresses from a total US ABS frame, we estimated state and national telephone append rates from Marketing Systems Group's sources. The append rates are summarized here and interactively at the website http://abs.rti.org/atlas/.
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Bourdeau, J. E., and R. D. Dyer. Regional-scale lake-sediment sampling and analytical protocols with examples from the Geological Survey of Canada. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/331911.

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Regional-scale lake sediment surveys have been successfully used since the 1970s as a means for reconnaissance geochemical exploration. Lake sediment sampling is typically performed in areas with a lack of streams and an overabundance of small-sized (=5 km across) lakes. Lake sediments are known to have major, minor and trace element concentrations that reflect the local geology. Overall, lake sediment surveys are planned and conducted following four distinct stages: 1) background research, 2) orientation survey, 3) regional survey, and 4) detailed survey. At the Geological Survey of Canada, samples are usually collected from a helicopter with floats. Sample density ranges from 1 sample per 6 - 13 km2. Samples are collected from the centre of the lake using a gravity torpedo sampler which corresponds to a hollow-pipe, butterfly bottom-valved sampler attached by a rope to the helicopter. Collected sediment samples are then placed in labelled bags and left to air dry. Detailed field notes and additional samples (field duplicates), for the purpose of an adequate quality assurance and quality control program, are also taken. Samples are then milled and sent to analytical laboratories for element determination. Commonly used analytical methods include: X-ray fluorescence (XRF), atomic absorption spectroscopy (AAS), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and -mass spectrometry (ICP-MS), instrumental neutron activation analysis (INAA), and/or determination of volatile compounds and organic carbon using Loss on Ignition (LOI). Analytical data is first evaluated for quality (contamination, accuracy and precision). Numerous options for the analysis of lake sediment data exist, ranging from simple basic element concentration maps and statistical graphical displays together with summary statistics, to employing multivariate methodologies, and, more recently, using machine learning algorithms. By adopting the set of guidelines and examples presented in this manual, scientific researchers, exploration geologists, geochemists and citizen scientists will be able to directly compare lake sediment datasets from anywhere in Canada.
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Johnson, Sarah, Michael Sinclair, Emily Leonard, and Forrest Rosenbower. Development of strategies for monitoring and managing sandscape vegetation, with an assessment of declining vegetation in the Apostle Islands National Lakeshore. National Park Service, April 2022. http://dx.doi.org/10.36967/nrr-2293187.

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Coastal dune habitats such as those of the Apostle Islands National Lakeshore (APIS) are regionally rare habitats of global and state-wide concern. Their dynamic, sandy landforms provide habitat for unique species specifically adapted to frequent disturbance, drought, and other stresses. Despite having disturbance-driven life histories, these species are at risk due to increased visitor use of sandscape habitats and environmental change. Resource managers at APIS have long understood the values of these sandscapes and threats presented by recreational trampling, but more recently they have recognized the precarious position that these coastal habitats are in due to their proximity to the lake and exposure to weather-related phenomena linked with long-term climate change. In recognition of emerging threats and the need to track impacts of these threats, park managers initiated a revision of their methods for monitoring sandscape vegetation. We applied these methods to 15 sandscape locations within the national lakeshore in 2014. Here, we outline what these revisions to the methods were, assess the current status of sandscape structure and composition, assess the utility of data collected with these methods, provide suggestions for further revisions of the sampling method, outline a two-tiered sampling approach for future monitoring, and we provide management recommendations. In a second section of the report, we provide a focused assessment of the size and health of Juniperus communis (common juniper), a target species of concern in these sandscape communities after it was observed by park managers to be dying or stressed on Michigan Island. Our assessments include the status of J. communis across all sandscapes monitored in 2014, and an analysis of change over time since 2012 in the health of J. communis on Michigan, Outer, and Stockton Islands. We provide evidence of impacts by rodents on foliar dieback, primarily on Michigan Island, and we discuss possible interactions with the non-native pale juniper web-worm (Aethes rutilana) and with climate change.
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Johnson, Sarah, Michael Sinclair, Emily Leonard, and Forrest Rosenbower. Development of strategies for monitoring and managing sandscape vegetation, with an assessment of declining vegetation in the Apostle Islands National Lakeshore. National Park Service, April 2022. http://dx.doi.org/10.36967/nrr-2293187.

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Coastal dune habitats such as those of the Apostle Islands National Lakeshore (APIS) are regionally rare habitats of global and state-wide concern. Their dynamic, sandy landforms provide habitat for unique species specifically adapted to frequent disturbance, drought, and other stresses. Despite having disturbance-driven life histories, these species are at risk due to increased visitor use of sandscape habitats and environmental change. Resource managers at APIS have long understood the values of these sandscapes and threats presented by recreational trampling, but more recently they have recognized the precarious position that these coastal habitats are in due to their proximity to the lake and exposure to weather-related phenomena linked with long-term climate change. In recognition of emerging threats and the need to track impacts of these threats, park managers initiated a revision of their methods for monitoring sandscape vegetation. We applied these methods to 15 sandscape locations within the national lakeshore in 2014. Here, we outline what these revisions to the methods were, assess the current status of sandscape structure and composition, assess the utility of data collected with these methods, provide suggestions for further revisions of the sampling method, outline a two-tiered sampling approach for future monitoring, and we provide management recommendations. In a second section of the report, we provide a focused assessment of the size and health of Juniperus communis (common juniper), a target species of concern in these sandscape communities after it was observed by park managers to be dying or stressed on Michigan Island. Our assessments include the status of J. communis across all sandscapes monitored in 2014, and an analysis of change over time since 2012 in the health of J. communis on Michigan, Outer, and Stockton Islands. We provide evidence of impacts by rodents on foliar dieback, primarily on Michigan Island, and we discuss possible interactions with the non-native pale juniper web-worm (Aethes rutilana) and with climate change.
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10

Løvschal, Mette, Havananda Ombashi, Marianne Høyem Andreasen, Bo Ejstrud, Renée Enevikd, Astrid Jensen, Mette Klingenberg, Søren Munch Kristiansen, and Nina Helt Nielsen. The Protected Burial Mound ‘Store Vejlhøj’, Vinderup, Denmark: First Results. Det Kgl. Bibliotek, 2023. http://dx.doi.org/10.7146/aulsps-e.479.

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An archaeological excavation of the protected burial mound Store Vejlhøj in northwestern Denmark was carried out in October-November 2021. The excavation formed part of the ERC-funded research project called ANTHEA, focusing on the deep history of anthropogenic heathlands. It was conducted by Aarhus University in collaboration with Holstebro Museum and Moesgaard Museum. The aim was to test a new method of sampling pollen data from different construction stages in a burial mound and comparing them with pollen data from nearby lake sediments with a view to improving our understanding of prehistoric anthropogenic heathland dynamics. Prior to the excavation, soil cores were collected from two nearby peat sediments as well as six burial mounds (including Store Vejlhøj) within a 1 km range of Lake Skånsø, where previous pollen analyses had been carried out. Based on these preliminary corings, Store Vejlhøj was selected for further archaeological investigation. A dispensation for excavating the protected mound was granted by the Danish Palaces and Culture Agency. The excavation was based on a 5 m long trench through the barrow, moving from its foot inwards. The surface vegetation and 40 cm topsoil were removed by an excavator, after which the remainder of the trench was manually dug in horizontal layers. Observation conditions were good. The excavation revealed a series of well-defined barrow construction stages, as well as unusually wellpreserved turf structures. Only two archaeological finds could be related to the barrow, both of which were later than its initial construction: a secondary urn in the top layer, and the base of a second urn at the foot of the mound. The burial mound was constructed using a minimum of three shells, which could be observed in the trench profile. Turfs were most probably collected locally in a landscape dominated by grass pastures, where no previous turf cutting had taken place. A total of 34 soil samples were collected for paleoecological analyses (pollen, Non-Pollen Polymorphs (NPPs), macrofossils) and geoarchaeological analyses (micromorphology, bulk samples). Preliminary pollen and macrofossil results from the burial mound revealed poor preservation conditions, which prompted a trench extension of 0.5 m by 0.2 m to find better preservation conditions. This extension resulted in the collection of a single final macrofossil sample, although there was no identifiable change in the in-situ preservation conditions. The dating results of the mound have not yet been completed and will be included as appendix 4-6 in 2023.
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