HITECS: A UML Profile and Analysis Framework for Hardware-in-the-Loop Testing of Cyber Physical Systems

Hardware-in-the-loop (HiL) testing is an important step in the development of cyber physical systems (CPS). CPS HiL test cases manipulate hardware components, are time-consuming and their behaviors are impacted by the uncertainties in the CPS environment. To mitigate the risks associated with HiL testing, engineers have to ensure that (1) HiL test cases are well-behaved, i.e., they implement valid test scenarios and do not accidentally damage hardware, and (2) HiL test cases can execute within the time budget allotted to HiL testing. This paper proposes an approach to help engineers systematically specify and analyze CPS HiL test cases. Leveraging the UML profile mechanism, we develop an executable domain-specific language, HITECS, for HiL test case specification. HITECS builds on the UML Testing Profile (UTP) and the UML action language (Alf). Using HITECS, we provide analysis methods to check whether HiL test cases are well-behaved, and to estimate the execution times of these test cases before the actual HiL testing stage. We apply HITECS to an industrial case study from the satellite domain. Our results show that: (1) HITECS is feasible to use in practice; (2) HITECS helps engineers define more complete and effective well-behavedness assertions for HiL test cases, compared to when these assertions are defined without systematic guidance; (3) HITECS verifies in practical time that HiL test cases are well-behaved; and (4) HITECS accurately estimates HiL test case execution times

Uncertainty-aware Specification and Analysis for Hardware-in-the-Loop Testing of Cyber Physical Systems

Hardware-in-the-loop (HiL) testing is important for developing cyber physical systems (CPS). HiL test cases manipulate hardware, are time-consuming and their behaviors are impacted by the uncertainties in the CPS environment. To mitigate the risks associated with HiL testing, engineers have to ensure that (1) test cases are well-behaved, e.g., they do not damage hardware, and (2) test cases can execute within a time budget. Leveraging the UML profile mechanism, we develop a domain-specific language, HITECS, for HiL test case specification. Using HITECS, we provide uncertainty-aware analysis methods to check the well-behavedness of HiL test cases. In addition, we provide a method to estimate the execution times of HiL test cases before the actual HiL testing. We apply HITECS to an industrial case study from the satellite domain. Our results show that: (1) HITECS helps engineers define more effective assertions to check HiL test cases, compared to the assertions defined without any systematic guidance; (2) HITECS verifies in practical time that HiL test cases are well-behaved; (3) HITECS is able to resolve uncertain parameters of HiL test cases by synthesizing conditions under which test cases are guaranteed to be well-behaved; and (4) HITECS accurately estimates HiL test case execution times

An examination of writing practices in the secondary school

The purpose of this study was to examine the role of writing in Newfoundland high schools with a view to enhancing and diversifying that role. The writer’s interest in the issue was prompted by an analysis of writing practices and teacher attitudes to writing in one Newfoundland school district (see appendices). This interest led to a review of relevant literature on the role of writing. Since only a very few theses have dealt with writing in Newfoundland high schools, the study includes references to comparable situations throughout the western world. -- the writer was guided by four questions: What is the state of writing in Newfoundlaand high schools? Why should writing be taught? Why is writing not being taught more effectively? What can we do to give writing more prominence in our high schools? -- Answers to these four questions were arrived at through references to literature and to the writer’s personal experiences as a high school teacher. To the first of these questions the writer concludes that writing is not being well taught. To the second question he concludes that writing should be taught by all teachers for the variety of benefits it can bring to students, including self-fulfillment, improved post-secondary opportunities, and most importantly, vastly improved learning of subject matter. -- The third question, of why writing is not used more effectively, revealed these factors, among others: teacher workload, misconceptions about the nature and the need for writing, subject area specialization and the difficulty of evaluating writing. -- In response to the fourth question, the writer has attempted to explain how writing can be given more prominence through teacher education, stress on reading, the development of writing across the curriculum, and renewed evaluation practices. -- The study concludes with a discussion of evaluation of writing as it is and as it should be done and gives recommendations for improving the state of writing

Development and exploitation of GPS attitude determination for microsatellites

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Annual Report of the Board of Regents of the Smithsonian Institution, showing the operations, expenditures, and condition of the Institution to July, 1897.

Annual Report of the Smithsonian Institution. 14 Apr. HD 575 (pts. 1-3), 55-2, v78-79 (pts. 1 and 2), 2308p. [3706-3708] Research related to the American Indian