TEMPORARY DIMENSIONS OF MULTIVARIATE DATA FROM PALEOCLIMATE RECORDS — A NOVEL MEASURE FOR DYNAMIC CHARACTERIZATION OF LONG-TERM CLIMATE CHANGE

2007 ◽  
Vol 17 (10) ◽  
pp. 3685-3689 ◽  
Author(s):  
REIK DONNER ◽  
ANNETTE WITT
Keyword(s):  
Multivariate Time Series ◽  
Measurement Data ◽  
Synthetic Data ◽  
Point Of View ◽  
Data Sets ◽  
Element Abundances ◽  
Paleoclimate Records ◽  
Standard Techniques

Standard techniques of nonlinear data analysis are difficult to apply to short or insufficiently resolved multivariate time series. We demonstrate that dimension estimation based on the decay of eigenvalues of the covariance matrix yields qualitatively robust characteristics even in the case of very short measurement series. The uncertainty of these characteristics is discussed for both: synthetic data sets and measurement data. We apply this approach to measurements of trace element abundances in a marine sediment core obtained at the East Antarctic coast and discuss the results from a paleoclimate point of view.

scholarly journals Intention, Principle, Outputs and Aims of the Experimental Pavilion Research of Building Envelopes Including Windows for Wooden Buildings

2017 ◽  
Vol 13 (1) ◽  
pp. 42-51 ◽  
Author(s):  
Daniela Štaffenová ◽  
Ján Rybárik ◽  
Miroslav Jakubčík
Keyword(s):  
Experimental Research ◽  
Climatic Conditions ◽  
Point Of View ◽  
Physical Parameters ◽  
Data Sets ◽  
Data Set ◽  
Building Envelopes ◽  
Climate Conditions ◽  
Time Period

AbstractThe aim of experimental research in the area of exterior walls and windows suitable for wooden buildings was to build special pavilion laboratories. These laboratories are ideally isolated from the surrounding environment, airtight and controlled by the constant internal climate. The principle of experimental research is measuring and recording of required physical parameters (e.g. temperature or relative humidity). This is done in layers of experimental fragment sections in the direction from exterior to interior, as well as in critical places by stable interior and real exterior climatic conditions. The outputs are evaluations of experimental structures behaviour during the specified time period, possibly during the whole year by stable interior and real exterior boundary conditions. The main aim of this experimental research is processing of long-term measurements of experimental structures and the subsequent analysis. The next part of the research consists of collecting measurements obtained with assistance of the experimental detached weather station, analysis, evaluation for later setting up of reference data set for the research locality, from the point of view of its comparison to the data sets from Slovak Hydrometeorological Institute (SHMU) and to localities with similar climate conditions. Later on, the data sets could lead to recommendations for design of wooden buildings.

scholarly journals Comparison of GPS tropospheric delays derived from two consecutive EPN reprocessing campaigns from the point of view of climate monitoring

2016 ◽  
Vol 9 (9) ◽  
pp. 4861-4877 ◽  
Author(s):  
Zofia Baldysz ◽  
Grzegorz Nykiel ◽  
Andrzej Araszkiewicz ◽  
Mariusz Figurski ◽  
Karolina Szafranek
Keyword(s):  
Time Series ◽  
Point Of View ◽  
Trend Test ◽  
Data Sets ◽  
Total Delay ◽  
University Of Technology ◽  
Time Period ◽  
Seasonal Signals ◽  
Linear Trends

Abstract. The main purpose of this research was to acquire information about consistency of ZTD (zenith total delay) linear trends and seasonal components between two consecutive GPS reprocessing campaigns. The analysis concerned two sets of the ZTD time series which were estimated during EUREF (Reference Frame Sub-Commission for Europe) EPN (Permanent Network) reprocessing campaigns according to 2008 and 2015 MUT AC (Military University of Technology Analysis Centre) scenarios. Firstly, Lomb–Scargle periodograms were generated for 57 EPN stations to obtain a characterisation of oscillations occurring in the ZTD time series. Then, the values of seasonal components and linear trends were estimated using the LSE (least squares estimation) approach. The Mann–Kendall trend test was also carried out to verify the presence of linear long-term ZTD changes. Finally, differences in seasonal signals and linear trends between these two data sets were investigated. All these analyses were conducted for the ZTD time series of two lengths: a shortened 16-year series and a full 18-year one. In the case of spectral analysis, amplitudes of the annual and semi-annual periods were almost exactly the same for both reprocessing campaigns. Exceptions were found for only a few stations and they did not exceed 1 mm. The estimated trends were also similar. However, for the reprocessing performed in 2008, the trends values were usually higher. In general, shortening of the analysed time period by 2 years resulted in a decrease of the linear trends values of about 0.07 mm yr−1. This was confirmed by analyses based on two data sets.

Characterization of Earth Materials Properties for Conceptual Design of an Exploratory Shaft, Richton Dome, Mississippi

1983 ◽  
Vol 26 ◽  
Author(s):  
R. D. Haag ◽  
O. E. Swanson
Keyword(s):  
Grain Size ◽  
Unit Weight ◽  
Data Sets ◽  
Expansive Clays ◽  
Pump Test ◽  
Geophysical Logs ◽  
Future Work ◽  
Shaft Wall

ABSTRACTPreliminary Exploratory Shaft design studies have been performed for representative sites in all salt basins within the NWTS Program. These studies have been based on data which are not site specific. Earth materials overlying the Richton Dome were characterized by analysis of geotechnical and hydrological data that had been acquired for site selection purposes. Data sets were reorganized, reinterpreted and evaluated in light of published empirical correlations, known constituative relations, experience with other sites, and engineering judgment.Geotechnical properties were assessed from geophysical logs, lithologic sample descriptions, and limited blowcount, grain size and pump test data. These properties included grain size, plasticity, unit weight, moisture content, bulk density, porosity, shear strength, elasticity, permeability, and saturation. Additionally, chemical and thermal properties were estimated and the local hydrologic flow properties were addressed.The analyses allowed heretofor unrecognized lithologic material groupings (defineable layers and sublayers) to be identified based on similarities in physical properties. Subsurface conditions, as interpreted, pose no unique excavation problems. However, the analysis identified some potential issues which had not been previously recognized and gave confidence that other previously assumed potential problems may not exist. Future work for subsequent design should focus on shaft wall stability, ground-water inflow, expansive clays, and the impacts of long-term exposure of the materials.

scholarly journals Characterization of the Rotation of Cometary Nuclei

1991 ◽  
Vol 116 (2) ◽  
pp. 690-721 ◽  
Author(s):  
Michael J. S. Belton
Keyword(s):  
Time Series ◽  
Cometary Nucleus ◽  
Rotational State ◽  
Point Of View ◽  
Data Sets ◽  
Primary Methods ◽  
Cometary Nuclei ◽  
Rotational States ◽  
Future Data

Abstract.I review the primary methods used to determine the spin state of cometary nuclei and the pitfalls and successes experienced in their use. There are in excess of 60 reported determinations of rotational periodicities, but only a few (~4) appear to be reliable, and even these do not necessarily fully describe the true rotational state. An adequate rotational ephemeris is not, at present, available for a single cometary nucleus.Because recent studies indicate that active cometary nuclei could be in excited spin states, I also review the theory of rigid body rotation from the point of view of remote (astronomical) observers, covering what is known of the effects of nutation on lightcurves, the influence of torques induced by jet activity, and the effects of internal energy and mass dissipation, and nuclear splitting.The available knowledge on rotation for 8 comets, including P/Halley, is reviewed. Outstanding questions that need early resolution are: (1) Can a consensus be achieved on the rotational state of P/Halley? (2) Is it possible to accurately determine the amplitude of the transverse non-gravitational force associated with rotation? (3) Are the orientations of fan-like comas a valid indicator of the orientation of the spin vector – can definitive observational checks be made in a few cases?Improved observational and interpretational techniques are needed to advance this field. Improved time-series and zero-date analyses are needed to connect existing and future data sets and to search for multiple periodicities in cometary lightcurves; improved sampling and extension of time-series observations with moderate- and large-aperture telescopes at good sites is needed; near-simultaneous photometric and radiometric observations made when cometary activity is low are particularly significant; well-sampled time-series imaging of near-nuclear phenomena (together with adequate software to analyze them) is essential to diagnose rotational states if nutation is present.

scholarly journals Mikromorfologie v archeologickém kontextu jako nástroj pro interpretace vzniku výplní pravěkých objektů: případová studie z Tvrdonic, okr. Břeclav

2020 ◽  
pp. 87-95
Author(s):  
Lenka Lisá ◽  
František Trampota
Keyword(s):  
Bronze Age ◽  
Point Of View ◽  
Soil Material ◽  
Floor Layer ◽  
La Tène ◽  
Modified Surface ◽  
La Tene

Micromorphology in the archaeological context is a methodological tool of modern multidisciplinary archeology. It is basically a microscopic characterization of sediments in a direct context of archaeological situations with the aim of detecting formation processes, the knowledge of which is essential for further interpretations. This method was applied to the sediment fill of two features in a stratigraphic relationship from the locality Tvrdonice – “Pole od Týnecka”. Samples were taken from a La Tène recessed structure fill and an earlier Bronze Age pit that is superimposed below the La Tène feature. From a macroscopic and micromorphological point of view, it is evident that the fill of an Early Bronze Age feature consists of wind-blown sands in superposition with in situ or slightly displaced soil material. Micro-layers detected macroscopically are only related to object leveling. The layer of soil beneath the “floor” of the La Tène recessed building displays signs of long-term bioturbated soil, i.e. the La Tène building was founded in an existing depression. The active floor layer of the La Tène building is represented by alternating layers of lighter and darker laminae. While the darker laminae represent the trampled layer, the lighter laminae consist of recrystallized ash, which impregnates the trampled layer. On a social level, this finding can be interpreted as the creators of the La Tène recessed building choosing to minimize labour costs by using the recessed terrain and thus avoiding the excavation of the building floor. The utility area possessed a purposefully modified surface, which is related to ergonomic efficiency, but its function is unknown. The uppermost part of the fill is formed by backfill that does not show any signs of pedogenic influences, which indicates that the object was intentionally filled (leveled).

scholarly journals Workshop on Overcoming Measurement Barriers to Internet Research (WOMBIR 2021) final report

2021 ◽  
Vol 51 (3) ◽  
pp. 33-40
Author(s):  
KC Claffy ◽  
David Clark ◽  
John Heidemann ◽  
Fabian Bustamante ◽  
Mattijs Jonker ◽  
...  
Keyword(s):  
Critical Infrastructure ◽  
Measurement Data ◽  
Internet Research ◽  
Final Report ◽  
Data Sets ◽  
Data Set ◽  
Research Areas ◽  
Mobile Networking ◽  
Network Properties

In January and April 2021 we held the Workshop on Overcoming Measurement Barriers to Internet Research (WOMBIR) with the goal of understanding challenges in network and security data set collection and sharing. Most workshop attendees provided white papers describing their perspectives, and many participated in short-talks and discussion in two virtual workshops over five days. That discussion produced consensus around several points. First, many aspects of the Internet are characterized by decreasing visibility of important network properties, which is in tension with the Internet's role as critical infrastructure. We discussed three specific research areas that illustrate this tension: security, Internet access; and mobile networking. We discussed visibility challenges at all layers of the networking stack, and the challenge of gathering data and validating inferences. Important data sets require longitudinal (long-term, ongoing) data collection and sharing, support for which is more challenging for Internet research than other fields. We discussed why a combination of technical and policy methods are necessary to safeguard privacy when using or sharing measurement data. Workshop participant proposed several opportunities to accelerate progress, some of which require coordination across government, industry, and academia.

scholarly journals On revolutions

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Armand M. Leroi ◽  
Ben Lambert ◽  
Matthias Mauch ◽  
Marina Papadopoulou ◽  
Sophia Ananiadou ◽  
...  
Keyword(s):  
Quantitative Data ◽  
Time Series Data ◽  
Multivariate Time Series ◽  
Rate Of Change ◽  
Series Data ◽  
Data Sets ◽  
Profound Change ◽  
Cultural Changes ◽  
Background Rate

AbstractSometimes the normal course of events is disrupted by a particularly swift and profound change. Historians have often referred to such changes as “revolutions”, and, though they have identified many of them, they have rarely supported their claims with statistical evidence. Here, we present a method to identify revolutions based on a measure of multivariate rate of change called Foote novelty. We define revolutions as those periods of time when the value of this measure is, by a non-parametric test, shown to significantly exceed the background rate. Our method also identifies conservative periods when the rate of change is unusually low. We apply it to several quantitative data sets that capture long-term political, social and cultural changes and, in some of them, identify revolutions — both well known and not. Our method is general and can be applied to any phenomenon captured by multivariate time series data of sufficient quality.

scholarly journals Seasonal effects in the long-term correction of short-term wind measurements using reanalysis data

2021 ◽  
Author(s):  
Alexander Basse ◽  
Doron Callies ◽  
Anselm Grötzner ◽  
Lukas Pauscher
Keyword(s):  
Reference Data ◽  
Measurement Data ◽  
Reanalysis Data ◽  
Seasonal Effects ◽  
Data Sets ◽  
Data Set ◽  
Abstract Measure ◽  
Wind Measurements ◽  
Theoretical Considerations

Abstract. Measure-Correlate-Predict (MCP) approaches are often used to correct wind measurements to the long-term wind conditions on site. This paper investigates systematic errors in MCP-based long-term corrections which occur if the measurement on site covers only a few months (seasonal biases). In this context, two common linear MCP methods are tested and compared, namely Variance Ratio and Linear Regression with Residuals. Wind measurement data from 18 sites with different terrain complexity in Germany are used (measurement heights between 100 and 140 m). Six different reanalysis data sets serve as the reference (long-term) wind data in the MCP calculations. Besides experimental results, theoretical considerations are presented which provide the mathematical background for understanding the observations. General relationships are derived which trace the seasonal biases to the mechanics of the methods and the properties of the reanalysis data sets. This allows the transfer of the results of this study to different measurement durations, other reference data sets and other regions of the world. In this context, it is shown both theoretically and experimentally that the results do not only depend on the selected reference data set but also significantly change with the choice of the MCP method.

Automated Tissue Analysis – a Bioinformatics Perspective

2005 ◽  
Vol 44 (01) ◽  
pp. 32-37 ◽  
Author(s):  
K. Boyce ◽  
A. Kriete
Keyword(s):  
Gene Expression ◽  
Machine Vision ◽  
Tissue Injury ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Quantitative Information ◽  
Point Of View ◽  
Data Sets ◽  
Tissue Analysis

Summary Objectives: Recent progress in automated tissue analysis (tissomics) provides reproducible phenotypical characterization of histological specimens. We introduce informatics tools to cluster and correlate quantitative tissue profiles with gene expression data. The great potential of synergies between tissue analysis and bioinformatics and its perspectives in medical research and computational diagnostics are discussed. Methods: Key enablers in microscopic imaging and machine vision are reviewed to perform a high-throughput tissue analysis. Methodologies are described and results are demonstrated that support a combined analysis of tissue with gene expression profiles whereby the consideration of individual responses is key. Results: Comprehensive histomorphometric profiles, extracted using machine vision, provide information regarding the components and heterogeneity of a tissue in a reproducible format amenable to data mining and analysis. Tissue quantitative information can be placed in synergetic context with bioinformatics data, such as gene expression profiles, for a more comprehensive stratification of individual responses. From a bioinformatics point of view tissue data are co-variants that support the identification of candidate genes relevant in tissue injury or disease. Conclusions: Progress in automated analytics enables the generation of quantitative data about tissue previously limited to visual histopathology. Such reproducible data sets can be statistically correlated and clustered throughout the continuum of bioinformatics. The combined approach supports a system-wide view of biology and has a potential to accelerate developments for a personalized computational diagnosis.

scholarly journals Seasonal effects in the long-term correction of short-term wind measurements using reanalysis data

2021 ◽  
Vol 6 (6) ◽  
pp. 1473-1490
Author(s):  
Alexander Basse ◽  
Doron Callies ◽  
Anselm Grötzner ◽  
Lukas Pauscher
Keyword(s):  
Wind Speed ◽  
Reference Data ◽  
Measurement Data ◽  
Theoretical Framework ◽  
Reanalysis Data ◽  
Seasonal Effects ◽  
Data Sets ◽  
Mean Wind Speed ◽  
Wind Measurements

Abstract. Measure–correlate–predict (MCP) approaches are often used to correct wind measurements to the long-term wind conditions on-site. This paper investigates systematic errors in MCP-based long-term corrections which occur if the measurement on-site covers only a few months (seasonal biases). In this context, two common linear MCP methods are tested and compared with regard to accuracy in mean, variance, and turbine energy production – namely, variance ratio (VR) and linear regression with residuals (LR). Wind measurement data from 18 sites with different terrain complexity in Germany are used (measurement heights between 100 and 140 m). Six different reanalysis data sets serve as the reference (long-term) wind data in the MCP calculations. All these reanalysis data sets showed an overpronounced annual course of wind speed (i.e., wind speeds too high in winter and too low in summer). However, despite the mathematical similarity of the two MCP methods, these errors in the data resulted in very different seasonal biases when either the VR or LR methods were used for the MCP calculations. In general, the VR method produced overestimations of the mean wind speed when measuring in summer and underestimations in the case of winter measurements. The LR method, in contrast, predominantly led to opposite results. An analysis of the bias in variance did not show such a clear seasonal variation. Overall, the variance error plays only a minor role for the accuracy in energy compared to the error in mean wind speed. Besides the experimental analysis, a theoretical framework is presented which explains these phenomena. This framework enables us to trace the seasonal biases to the mechanics of the methods and the properties of the reanalysis data sets. In summary, three aspects are identified as the main influential factors for the seasonal biases in mean wind speed: (1) the (dis-)similarity of the real wind conditions on-site in correlation and correction period (representativeness of the measurement period), (2) the capability of the reference data to reproduce the seasonal course of wind speed, and (3) the regression parameter β1 (slope) of the linear MCP method. This theoretical framework can also be considered valid for different measurement durations, other reference data sets, and other regions of the world.

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