The promise of simulation-based science assessment: the Calipers project

Abstract: The Calipers project developed and studied a new generation of simulation-based assessment systems. The project aimed to demonstrate the potential of technology-and simulation-based assessments to provide high-quality evidence of complex performances for science tests that address accountability or formative goals. End-of-unit, benchmark assessments for the topics of ecosystems and for forces and motion were developed to test national science standards at the middle school and secondary levels. Technical quality evidence documented the alignment of the assessments with national science standards, expert reviews of content and item quality, cognitive analyses of students thinking-aloud, and analyses of teacher and student data gathered from classroom pilot testing. The project broke new ground in harnessing the affordances of technology to transform what, how, when and where science learning is assessed and to gather evidence of students' connected science knowledge and extended inquiry not well measured by traditional paper-based tests

Exploratory Analysis in Learning Analytics

This article summarizes the methods, observations, challenges and implications for exploratory analysis drawn from two learning analytics research projects. The cases include an analysis of a games-based virtual performance assessment and an analysis of data from 52,000 students over a 5-year period at a large Australian university. The complex datasets were analyzed and iteratively modeled with a variety of computationally intensive methods to provide the most effective outcomes for learning assessment, performance management and learner tracking. The article presents the research contexts, the tools and methods used in the exploratory phases of analysis, the major findings and the implications for learning analytics research methods

Sterowanie serwo-pneumatyczne w urządzeniu eksperymentalnym

The paper presents the control concept for an experimental rig with closed-loop controlled pneumatic axis. The objective is the convenient execution of diverse control technologic experiments using free implementable control structures. Since two actuators can be mechanically linked to one another, one is force controlled to generate defined disturbances. Furthermore, a particular simulation model, which can be integrated in the controllers' user program, is pointed out including non-linear effects. Finally, selected experiments are discussed.W artykule przedstawiono koncepcję sterowania w urządzeniu eksperymentalnym z osią sterowaną pneumatycznie w zamkniętej pętli. Celem była dogodna realizacja eksperymentów technicznych, w których swobodnie implementowano różne struktury sterowania. Ponieważ dwa siłowniki mogą być mechanicznie powiązane ze sobą, jeden z nich jest sterowany siłą w celu generowania zakłóceń. Ponadto, wskazano szczególny model symulacyjny uwzględniający efekty nieliniowe, który może być zintegrowany z programem sterownika tworzonym przez użytkownika. W części końcowej przedyskutowano wyniki wybranych eksperymentów

Drive data acquisition for controller internal monitoring functions

With the current trend of increasing automation, leading to self-organizing machine tools and production machines (“Industry 4.0”), data acquisition and processing becomes more and more important. Based on these data, new monitoring functions and identification methods can be implemented in the machine control. Depending on the algorithms, also drive internal data, such as the actual torque, or the power consumption of the machine axes are required, partially at high sample rates. State of the art computerized numerical controllers (e.g. SIEMENS 840D sl) however, are characterized by a separation of drive system and controller. Drive data, which is not included in the standard bus-connection are difficult to access by the superordinated CNC. The paper addresses this problem, presents and compares various concepts of drive data transfer to a standard industrial CNC/PLC. Subsequently, the most convenient method, which utilizes a drive-internal data recorder is chosen for implementation. It offers flexible drive data acquisition through the PLC at high sample rates, carried out block wise. Experimental results are shown to prove the functionality. Finally, ideas for continuative monitoring and identification methods are discussed