A survey of adaptive control technology in robotics

Previous work on the adaptive control of robotic systems is reviewed. Although the field is relatively new and does not yet represent a mature discipline, considerable attention has been given to the design of sophisticated robot controllers. Here, adaptive control methods are divided into model reference adaptive systems and self-tuning regulators with further definition of various approaches given in each class. The similarity and distinct features of the designed controllers are delineated and tabulated to enhance comparative review

The evolution of the Aristolochia pallida complex (Aristolochiaceae) challenges traditional taxonomy and reflects large-scale glacial refugia in the Mediterranean

The taxonomy of the Mediterranean Aristolochia pallida complex has been under debate since several decades with the following species currently recognized: A. pallida, A. lutea, A. nardiana, A. microstoma, A. merxmuelleri, A. croatica, and A. castellana. These taxa are distributed from Iberia to Turkey. To reconstruct phylogenetic and biogeographic patterns, we employed cpDNA sequence variation using both noncoding (intron and spacer) and protein-coding regions (i.e., trnK intron, matK gene, and trnK-psbA spacer). Our results show that the morphology-based traditional taxonomy was not corroborated by our phylogenetic analyses. Aristolochia pallida, A. lutea, A. nardiana, and A. microstoma were not monophyletic. Instead, strong geographic signals were detected. Two major clades, one exclusively occurring in Greece and a second one of pan-Mediterranean distribution, were found. Several subclades distributed in Greece, NW Turkey, Italy, as well as amphi-Adriatic subclades, and a subgroup of southern France and Spain, were revealed. The distribution areas of these groups are in close vicinity to hypothesized glacial refugia areas in the Mediterranean. According to molecular clock analyses the diversification of this complex started around 3–3.3 my, before the onset of glaciation cycles, and the further evolution of and within major lineages falls into the Pleistocene. Based on these data, we conclude that the Aristolochia pallida alliance survived in different Mediterranean refugia rarely with low, but often with a high potential for range extension, and a high degree of morphological diversity.Turkish Science Foundatio

Science teachers' pedagogical content knowledge development during enactment of socioscientific curriculum materials

The purpose of this study is to provide insight into short‐term professionalization of teachers regarding teaching socioscientific issues (SSI). The study aimed to capture the development of science teachers' pedagogical content knowledge (PCK) for SSI teaching by enacting specially designed SSI curriculum materials. The study also explores indicators of stronger and weaker development of PCK for SSI teaching. Thirty teachers from four countries (Cyprus, Israel, Norway, and Spain) used one module (30-60 min lesson) of SSI materials. The data were collected through: (a) lesson preparation form (PCK‐before), (b) lesson reflection form (PCK‐after), (c) lesson observation table (PCK‐in‐action). The data analysis was based on the PCK model of Magnusson, Krajcik, and Borko (1999). Strong development of PCK for SSI teaching includes 'Strong interconnections between the PCK components,' 'Understanding of students'difficulties in SSI learning,' 'Suggesting appropriate instructional strategies,' and 'Focusing equally on science content and SSI skills.' Our findings point to the importance of these aspects of PCK development for SSI teaching. We argue that when professional development programs and curriculum materials focus on developing these aspects, they will contribute to strong PCK development for SSI teaching. The findings regarding the development in the components of PCK for SSI provide compelling evidence that science teachers can develop aspects of their PCK for SSI with the use of a single module. Most of the teachers developed their knowledge about students' understanding of science and instructional strategies. The recognition of student difficulties made the teacher consider specific teaching strategies which are in line with the learning objectives. There is an evident link between the development of PCK in instructional strategies and students' understanding of science for SSI teaching

Copula-based probabilistic assessment of intensity and duration of cold episodes: A case study of Malayer vineyard region

Frost, particularly during the spring, is one of the most damaging weather phenomena for vineyards, causing significant economic losses to vineyards around the world each year. The risk of tardive frost damage in vine-yards due to changing climate is considered as an important threat to the sustainable production of grapes. Therefore, the cold monitoring strategies is one of the criteria with significant impacts on the yields and prosperity of horticulture and raisin factories. Frost events can be characterized by duration and severity. This paper investigates the risk and impacts of frost phenomenon in the vineyards by modeling the joint distribution of duration and severity factors and analyzing the influential parameter’s dependency structure using capabilities of copula functions. A novel mathematical framework is developed within this study to understand the risk and uncertainties associate with frost events and the impacts on yields of vineyards by analyzing the non-linear dependency structure using copula functions as an efficient tool. The developed model was successfully vali-dated for the case study of vineyard in Malayer city of Iran. The copula model developed in this study was shown to be a robust tool for predicting the return period of the frost events

International collaborative follow - up investigation of graduating high school students’ understandings of the nature of scientific inquiry: is progress Being made?

Understandings of the nature of scientific inquiry (NOSI), as opposed to engaging students in inquiry learning experiences, are included in science education reform documents around the world. However, little is known about what students have learned about NOSI during their pre-college school years. The purpose of this large-scale follow-up international project (i.e. 32 countries and regions, spanning six continents and including 3917 students for the high school sample) was to collect data on what exiting high school students have learned about NOSI. Additionally, the study investigated changes in 12th grade students’ NOSI understandings compared to seventh grade (i.e. 20 countries and regions) students’ understandings from a prior investigation [Lederman et al. (2019). An international collaborative investigation of beginning seventh grade students’ understandings of scientific inquiry: Establishing a baseline. Journal of Research in Science Teaching, 56(4), 486–515. https://doi.org/10.1002/tea.21512]. This study documents and discusses graduating high school students’ understandings and compares their understandings to seventh grade students’ understandings of the same aspects of scientific inquiry for each country. It is important to note that collecting data from each of the 130+ countries globally was not feasible. Similarly, it was not possible to collect data from every region of each country. A concerted effort was made, however, to provide a relatively representative picture of each country and the world

Development and demonstration of a teleoperated modular robot system

This collection of bi-monthly progress reports on the DOE/NE Robotics Program presents information on significant accomplishments, reports and major correspondence issued, important meetings, and major problems associated with the program

DETERMINATION OF BACLOFEN IN HUMAN PLASMA AND URINE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

An isocratic reversed-phase column liquid chromatographic assay for baclofen was developed. Prior to analysis, derivatization of urine or deproteinized plasma with 4-chloro-7-nitrobenzofurazan (NBD-CI) reagent was employed. After solid-phase extraction on a small silica gel column, the mixture was chromatographed on a 10 mu m Bondapak C-18 column using methanol-water (45 + 55 v/v) as the mobile phase, The NBD-baclofen derivative was detected spectrofluorimetrically by monitoring the emission at 524 nm with excitation at 463 nm. The method was tested for suitability in routine analysis. After a single oral dose of 20 mg of baclofen, the plasma concentration and the cumulative urinary excretion of the drug were determined. The average recoveries were 99.5 and 98.5% for plasma and urine, respectively

Development and demonstration of a teleoperated modular robot system. Bi-monthly progress report, January 1992--December 1992

This collection of bi-monthly progress reports on the DOE/NE Robotics Program presents information on significant accomplishments, reports and major correspondence issued, important meetings, and major problems associated with the program

A control structure for fault-tolerant operation of robotic manipulators

Failure of any component of a robotic system during operation is a matter of concern. This work investigates internal shock phenomena due to the failure of joint actuation, and a recovery algorithm for both serial and parallel mechanisms under such circumstances. A control algorithm is studied that consists of a model reference algorithm and computed torque method in the feedforward process, and a simple PID controller in the feedback process. Simulation results illustrate the effectiveness of this recovery algorithm which attempts to reduce the internal shock when failure occurs, and accomplish the tracking of the given end-effector trajectory. The outlined recovery algorithms. which include two stages of robot control, path planning and path tracking, are expected to be applied not only to a case where some joint is fully failed, but also to cases where some joints experience partial failure