We have designed and built a versatile modularized software library—ODYN—that wraps a comprehensive set of advanced data analysis methods meant to facilitate the study of turbulence, nonlinear ...dynamics, and complexity in space plasmas. The Python programming language is used for the algorithmic implementation of models and methods devised to understand fundamental phenomena of space plasma physics like elements of spectral analysis, probability distribution functions and their moments, multifractal analysis, or information theory. ODYN is an open‐source software analysis tool and freely available to any user interested in turbulence and nonlinear dynamics analysis and provides a tool to perform automatic analysis on large collections of space measurements, in situ or simulations, a feature that distinguishes ODYN from other similar software. A user‐friendly configurator is provided, which allows customization of key parameters of the analysis methods, most useful for nonprogrammers.
Key Points
We describe an open‐source software data analysis tool based on Python
The software includes a large portfolio of methods to analyze turbulence and nonlinear dynamics and visualize the results
The software tool is adapted to ingest and process large collections of spacecraft data as well as results of numerical simulations
Intermittency is a fundamental property of space plasma dynamics, characterizing turbulent dynamical variables as well as passive scalars. Its qualitative and quantitative description from in‐situ ...data requires an accurate estimation of the probability density functions (PDFs) of fluctuations and their moments, particularly the flatness, a normalized fourth order moment of the PDF. Such a statistical description needs a sufficiently large number of samples for the computation to be meaningful. Due to inherent technological limitations (e.g., limited telemetry bandwidth) not all samples collected on‐board can be sent to the ground for further analysis. Therefore, a technology designed to process on‐board the data and to compute the flatness is useful to fully exploit the capabilities of scientific instruments installed on robotic platforms, including nanosatellites. We designed, built, and tested in laboratory such a technology based on Field Programable Gate Arrays (FPGA). The building principle is the classical estimation of PDFs and their moments, based on normalized histograms of a measure. The technical design uses the FloPoCo (Floating‐Point Cores) framework with customized arithmetic operators; the computation block is a pipelined architecture, which computes a new value of the flatness in each clock cycle. The design and implementation achieve optimization directives of the FPGA resources relevant for operation in space, like area, energy efficiency, and precision. The technology was tested in laboratory using Xilinx SRL16 or SRLC32 macros and provides correct results validated with test time series provided by magnetic field data collected in the solar wind by ULYSSES spacecraft. The characteristics and performance of the laboratory prototype pave the way for a space qualified version of the laboratory design.
Plain Language Summary
The inherently limited resources on‐board spacecraft (telemetry bandwidth, computing power, and memory) allow that only a fraction of the scientific data are sent to the ground, thus available for scientific analysis. Complex strategies are put in place in order to select which fraction of data will be available for scientist on ground. Another approach is to perform the key data computations on‐board the spacecraft and send the results to the ground. We designed a module able to perform such calculations to estimate the flatness parameter–a key statistical descriptor of data variability helping scientists to understand the turbulent dynamics of space plasmas.
Key Points
A solution based on the FPGA technology is designed and tested to compute the flatness parameter, a key measure of intermittency in space
The design is optimized with respect to resource usage and can be deployed on space qualified FPGAs to be operated on‐board spacecraft
Tests with space‐borne data give excellent results confirmed by independent scientific software tools applied on the same test data
This paper describes research on a classification of physics problems in the context of introductory physics courses. This classification, called the Taxonomy of Introductory Physics Problems (TIPP), ...relates physics problems to the cognitive processes required to solve them. TIPP was created in order to design educational objectives, to develop assessments that can evaluate individual component processes of the physics problem-solving process, and to guide curriculum design in introductory physics courses, specifically within the context of a "thinking-skills" curriculum. Moreover, TIPP enables future physics education researchers to investigate to what extent the cognitive processes presented in various taxonomies of educational objectives are exercised during physics problem solving and what relationship might exist between such processes. We describe the taxonomy, give examples of classifications of physics problems, and discuss the validity and reliability of this tool. (Contains 8 tables and 6 figures.)
Context.
The physical mechanisms that favor the access of solar wind plasma into the magnetosphere have not been entirely elucidated to date. Studying the transport of finite-sized magnetosheath ...plasma irregularities across the magnetopause is fundamentally important for characterizing the Hermean environment (of Mercury) as well as for other planetary magnetic and plasma environments.
Aims.
We investigate the kinetic effects and their role on the penetration and transport of localized solar wind or magnetosheath plasma irregularities within the Hermean magnetosphere under the northward orientation of the interplanetary magnetic field.
Methods.
We used three-dimensional (3D) particle-in-cell (PIC) simulations adapted to the interaction between plasma elements (irregularities or jets) of a finite spatial extent and the typical magnetic field of Mercury’s magnetosphere.
Results.
Our simulations reveal the transport of solar wind plasma across the Hermean magnetopause and entry inside the magnetosphere. The 3D plasma elements are braked and deflected in the equatorial plane. The entry process is controlled by the magnetic field gradient at the magnetopause. For reduced jumps of the magnetic field (i.e., for larger values of the interplanetary magnetic field), the magnetospheric penetration is enhanced. The equatorial dynamics of the plasma element is characterized by a dawn-dusk asymmetry generated by first-order guiding center drift effects. More plasma penetrates into the dusk flank and advances deeper inside the magnetosphere than in the dawn flank.
Conclusions.
The simulated solar wind or magnetosheath plasma jets can cross the Hermean magnetopause and enter into the magnetosphere, as described by the impulsive penetration mechanism.
We have developed simple data-mining algorithms to assess the consistency and the randomness of student responses to problems consisting of multiple true or false statements. In this paper we ...describe the algorithms and use them to analyze data from introductory physics courses. We investigate statements that emerge as outliers because the class has a preference for the incorrect answer and also those that emerge as outliers because the students are randomly changing their responses. These outliers are found to include several statements that are known in the literature to expose student misconceptions. Combining this fact with comments made by students and results of complementary assessments provides evidence that the tendency of a group of students to change their answer to a true or false statement or to remain consistent can serve as indicators of whether the class has understood the relevant concept. Our algorithms enable teachers to employ problems of the type described as a tool to identify specific aspects of a course that require improvement. They also enable researchers to employ such problems in experiments designed to probe aspects of students' thought processes and behavior. Additionally, our results demonstrate that at least one category of research-inspired problems (ranking tasks) can be adapted to the linked true or false format and productively used as an assessment tool in an online setting. (Contains 1 table and 13 figures.)
The research is part of a program concerning the conservation of common bean biodiversity in S - E Romania and has the purpose to valorize local varieties of this specie. There were collected, ...cultivated and evaluated over 50 bean local varieties from the traditional vegetable areas of Romania. The research included numerous types of seeds: from very small to very big, with an only color (white, black, grey, yellow, brown), or more with 2 colors disposed around hilum, in streaks, on half of grain, in patches. There were made observation regarding the protocol of UPOV for distinctness, uniformity and stability tests. A special attention was given to the earliness and the qualitative and quantitative characteristics (absence of stringiness, pod’s degree of curvature, number and weight of pods per plant, length, thickness and weight of pod). This evaluation had the purpose to identify the local varieties that posses valuable characteristics which can be used in the next breeding works.
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