scholarly journals Evaluation of Chosen Parameters of Servomechanisms

2021 ◽  
pp. 12-20
Author(s):  
Natália Gecejová ◽  
Marek Češkovič ◽  
Pavol Kurdel

This paper provides a comprehensive view of the issues in the field of servomechanisms of unmanned aircraft, which are used in the Department of Avionics for both education and research purposes. This contribution will describe the methodology and individual measuring devices, facilitating the control of prescribed parameters with parameters measured in real conditions. As some manufacturers deliberately exaggerate the data of their products to compete with other manufacturers, it is important to have a proven and reliable method for the evaluation of these parameters. The last part provided the results of control measurements of the selected servomechanism.

Author(s):  
B. D. Athey ◽  
A. L. Stout ◽  
M. F. Smith ◽  
J. P. Langmore

Although there is general agreement that Inactive chromosome fibers consist of helically packed nucleosomes, the pattern of packing is still undetermined. Only one of the proposed models, the crossed-linker model, predicts a variable diameter dependent on the length of DNA between nucleosomes. Measurements of the fiber diameter of negatively-stained and frozen- hydrated- chromatin from Thyone sperm (87bp linker) and Necturus erythrocytes (48bp linker) have been previously reported from this laboratory. We now introduce a more reliable method of measuring the diameters of electron images of fibrous objects. The procedure uses a modified version of the computer program TOTAL, which takes a two-dimensional projection of the fiber density (represented by the micrograph itself) and projects it down the fiber axis onto one dimension. We illustrate this method using high contrast, in-focus STEM images of TMV and chromatin from Thyone and Necturus. The measured diameters are in quantitative agreement with the expected values for the crossed-linker model for chromatin structure


1987 ◽  
Vol 26 (02) ◽  
pp. 87-92 ◽  
Author(s):  
A. Verbruggen ◽  
C. De Bakker ◽  
A. Vandecruys ◽  
J. Joosten ◽  
A. Nevelsteen ◽  
...  

The action of antithrombotic drugs can be evaluated by measuring the deposition of111In-labelled platelets on peripheral bypass grafts several days after injection. This evaluation can be performed qualitatively (visual interpretation on the daily images) or quantitatively. Four different methods which calculate the ratio of platelet uptake with a reference region are compared: two methods use a gamma camera and two a detector. A blood sample or the region under the sternal angle are used as reference. The daily ratio of the counts, recorded by a gamma camera in a region of interest covering the graft, and the blood radioactivity interpolated from a platelet survival curve appears to be the most reliable method. The information of all the ratios can be combined in a single thrombogenicity index which reflects the daily rise of a linear or exponential regression versus time.


1981 ◽  
Vol 45 (03) ◽  
pp. 204-207 ◽  
Author(s):  
Wolfgang Siess ◽  
Peter Roth ◽  
Peter C Weber

SummaryPlatelets have been implicated in the development of atherosclerotic and thrombotic vascular diseases. Evaluation of platelet aggregation in relation to endogenously formed compounds which affect platelet function may provide information of clinical and pharmacological relevance. We describe a method in which thromboxane B2 (TXB2) formation was analyzed following stimulation of platelet-rich plasma (PRP) with ADP, 1-epinephrine, collagen, and arachidonic acid. In addition, we determined platelet sensitivity to prostacyclin following ADP- and collagen-induced platelet aggregation. The parameters under study were found to depend on the platelet count in PRP, on the type and dose of the aggregating agent used, and on the test time after blood sampling. By standardization of these variables, a reliable method was established which can be used in clinical and pharmacological trials.


2020 ◽  
Vol 4 (3) ◽  
pp. 544
Author(s):  
Ermaida Dewi

The background of this research is an instrument of learning for reading comprehension which in general is still dominated by an instrument in the form of print out which makes the students’ interest to read is reduced. In addition, this instrument is usually done manually or handwritten so that the students’ work must be corrected manually and require some time to get the results. This study aims to develop instruments or measuring devices for reading comprehension in the Primary School in Pekanbaru and find out the feasibility of measuring devices for reading comprehension skills. This product is Macromedia Flash 8 based namely "MaCaMi" which stands forMari Membaca dan Memahami. The research method used was the 4D model with four stages, such as the define stage, the design phase, the develop phase, and the dessiminate stage which is limited to the third stage. The data of this study were obtained from product design expert validation questionnaire, questionnaire validated by linguists, teacher response questionnaire and students response questionnaire. The data were generated quantitatively and analyzed by using the assessment criteria to determine the product quality. The results of this study showed the assessment of product design experts in draft 1 had an average percentage of 69.61% with the appropriate category then had increased in draft 2 to 90.56% with the very feasible category. The results of  the feasibility test by linguists in draft 1 with had average percentage of 95.30% with the very feasible category then increased in draft 2 to 97.20% withn the very feasible category. The results of the teacher's response to the reading comprehension measuring instrument in the Primary School in Pekanbaru developed by researchers obtained an average percentage of 93.50% with a very good category and the results of students' responses to the measuring instrument obtained an average percentage of 89.90% with a category very good. Based on these results, it can be concluded that the product developed by researchers is feasible to be used as a measure of reading comprehension ability of primary school students.


2012 ◽  
Vol 3 (6) ◽  
pp. 22-23
Author(s):  
Achalla Naga Valli Kameshwari Sravani ◽  
◽  
Gurneet Kaur ◽  
Shweta Singh ◽  
Mritunjay Kumar Singh
Keyword(s):  

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