Designing and Testing Contols to Mitigate Dynamic Loads in the Controls Advanced Research Turbine: Preprint

The National Renewable Energy Laboratory is designing, implementing, and testing advanced controls to maximize energy extraction and reduce structural dynamic loads of wind turbines. These control designs are based on a linear model of the turbine that is generated by specialized modeling software. In this paper, we show the design and simulation testing of a control algorithm to mitigate blade, tower, and drivetrain loads using advanced state-space control design methods

Designing and Testing Controls to Mitigate Tower Dynamic Loads in the Controls Advanced Research Turbine: Preprint

This report describes NREL's efforts to design, implement, and test advanced controls for maximizing energy extraction and reducing structural dynamic loads in wind turbines

Case Survey Studies in Software Engineering Research

Background: Given the social aspects of Software Engineering (SE), in the last twenty years, researchers from the field started using research methods common in social sciences such as case study, ethnography, and grounded theory. More recently, case survey, another imported research method, has seen its increasing use in SE studies. It is based on existing case studies reported in the literature and intends to harness the generalizability of survey and the depth of case study. However, little is known on how case survey has been applied in SE research, let alone guidelines on how to employ it properly. Aims: This article aims to provide a better understanding of how case survey has been applied in Software Engineering research. Method: To address this knowledge gap, we performed a systematic mapping study and analyzed 12 Software Engineering studies that used the case survey method. Results: Our findings show that these studies presented a heterogeneous understanding of the approach ranging from secondary studies to primary inquiries focused on a large number of instances of a research phenomenon. They have not applied the case survey method consistently as defined in the seminal methodological papers. Conclusions: We conclude that a set of clearly defined guidelines are needed on how to use case survey in SE research, to ensure the quality of the studies employing this approach and to provide a set of clearly defined criteria to evaluate such work.Comment: Accepted for presentation at ACM / IEEE International Symposium on Empirical Software Engineering and Measurement (ESEM) (ESEM '20

In search of the origins and enduring impact of agile software development

The Agile Manifesto is a philosophical touchpoint for all agile software development (ASD) methods. We examine the manifesto and some of its associated agile methods in an effort to identify the major impacts of ASD. We have encountered some difficulty in delineating agile and non-agile software processes, which is partially the result of terminological confusion. It is clear from the volume of published research that ASD has made a significant contribution, and we have identified two lasting and important impacts. Firstly, the reduction in iteration durations and secondly, the push for reduced levels of documentation (especially in relation to software requirements). Other aspects of the Agile Manifesto may not have exerted a significant impact; for example, the use of tooling to automate processes has become central to continuous software engineering (CSE) and may not be wholly congruent with the manifesto. Furthermore, many organisations may still rely on business contracts despite calls in the manifesto for greater levels of informal customer collaboration

An Empirical Study of Bots in Software Development -- Characteristics and Challenges from a Practitioner's Perspective

Software engineering bots - automated tools that handle tedious tasks - are increasingly used by industrial and open source projects to improve developer productivity. Current research in this area is held back by a lack of consensus of what software engineering bots (DevBots) actually are, what characteristics distinguish them from other tools, and what benefits and challenges are associated with DevBot usage. In this paper we report on a mixed-method empirical study of DevBot usage in industrial practice. We report on findings from interviewing 21 and surveying a total of 111 developers. We identify three different personas among DevBot users (focusing on autonomy, chat interfaces, and "smartness"), each with different definitions of what a DevBot is, why developers use them, and what they struggle with. We conclude that future DevBot research should situate their work within our framework, to clearly identify what type of bot the work targets, and what advantages practitioners can expect. Further, we find that there currently is a lack of general purpose "smart" bots that go beyond simple automation tools or chat interfaces. This is problematic, as we have seen that such bots, if available, can have a transformative effect on the projects that use them.Comment: To be published at the ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering (ESEC/FSE

Challenges in Survey Research

While being an important and often used research method, survey research has been less often discussed on a methodological level in empirical software engineering than other types of research. This chapter compiles a set of important and challenging issues in survey research based on experiences with several large-scale international surveys. The chapter covers theory building, sampling, invitation and follow-up, statistical as well as qualitative analysis of survey data and the usage of psychometrics in software engineering surveys.Comment: Accepted version of chapter in the upcoming book on Contemporary Empirical Methods in Software Engineering. Update includes revision of typos and additional figures. Last update includes fixing two small issues and typo

How communication of genetic information within the family is addressed in genetic counselling: a systematic review of research evidence

Supporting consultands to communicate risk information with their relatives is key to obtaining the full benefits of genetic health care. To understand how health-care professionals address this issue in clinical practice and what interventions are used specifically to assist consultands in their communication of genetic information to appropriate relatives, we conducted a systematic review. Four electronic databases and four subject-specific journals were searched for papers published, in English, between January 1997 and May 2014. Of 2926 papers identified initially, 14 papers met the inclusion criteria for the review and were heterogeneous in design, setting and methods. Thematic data analysis has shown that dissemination of information within families is actively encouraged and supported by professionals. Three overarching themes emerged: (1) direct contact from genetic services: sending letters to relatives of mutation carriers; (2) professionals' encouragement of initially reluctant consultands to share relevant information with at-risk relatives and (3) assisting consultands in communicating genetic information to their at-risk relatives, which included as subthemes (i) psychoeducational guidance and (ii) written information aids. Findings suggest that professionals' practice and interventions are predicated on the need to proactively encourage family communication. We discuss this in the context of what guidance of consultands by professionals might be appropriate, as best practices to facilitate family communication, and of the limits to non-directiveness in genetic counselling

Limitations and pitfalls of using family letters to communicate genetic risk: a qualitative study with patients and healthcare professionals

European genetic testing guidelines recommend that healthcare professionals (HCPs) discuss the familial implications of any test with a patient and offer written material to help them share the information with family members. Giving patients these “family letters” to alert any relatives of their risk has become part of standard practice and has gone relatively unquestioned over the years. Communication with at-risk relatives will become an increasingly pressing issue as mainstream and routine practice incorporates broad genome tests and as the number of findings potentially relevant to relatives increases. This study therefore explores problems around the use of family letters to communicate about genetic risk. We conducted 16 focus groups with 80 HCPs, and 35 interviews with patients, recruited from across the UK. Data were analyzed thematically and we constructed four themes: 1) HCPs writing family letters: how to write them and why?, 2) Patients’ issues with handing out family letters, 3) Dissemination becomes an uncontrolled form of communication, and 4) When the relative has the letter, is the patient’s and HCP’s duty discharged? We conclude by suggesting alternative and supplementary methods of communication, for example through digital tools, and propose that in comparison to communication by family letter, direct contact by HCPs might be a more appropriate and successful option

Conceptual design of a winged hybrid airship

The present study focuses on the sizing and aerodynamic contour design of a two-seater 1000 kg gross take-off mass winged hybrid airship. Unlike the conventional hybrid airships, which stay aloft and takeoff with the help of VTOL propulsion systems, a winged hybrid airship requires a certain speed to takeoff by utilizing lift coming from its aerodynamic surfaces. Heaviness fraction and takeoff ground roll are considered as measure of merit in initial sizing. Based on the design requirement of Malaysian inter-island tourism and transportation of agricultural products, range is set to 450 km and ground roll for take-off about 150 m. For the airship to be heavy enough for ground handling, the ratio of hydrostatic to hydrodynamic lift is set equal to 49:51. Summary of the results to be obtained in early design phase will give a baseline start to study the aerodynamics and stability characteristics of such airships in future