A Novel Experimental Approach Using A Reconfigurable Test Setup For Complex Nonlinear Dynamic Systems

Experimental nonlinear dynamics is an important area of study in the modern engineering field, with engineering applications in structural dynamics, structural control, and structural health monitoring. As a result, the discipline has experienced a great influx of research efforts to develop a versatile and reliable experimental methodology. A technical challenge in many experimental studies is the procurement of a device that exhibits the desired nonlinear behavior. As a result, many researchers have longed for a versatile, but accurate, testing methodology that has complete freedom to simulate a wide range of nonlinearities and stochastic behaviors. The objective of this study is to develop a reconfigurable test setup as a tool to be used in a wide range of nonlinear dynamic studies. The main components include a moving mass whose restoring force can accurately be controlled and reprogrammed (with software) based upon measured displacement and velocity readings at each time step. The device offers control over nonlinear characteristics and the equation of dynamic motion. The advantage of having such an experimental setup is the ability to simulate various types of nonlinearities with the same test setup. As a result, the data collected can be used to help validate nonlinear modeling, system identification, and stochastic analysis studies. A physical test apparatus was developed, and various mechanical, electrical, and programming calibrations were performed for reliable experimental studies. To display potential uses for the reconfigurable approach, examples are presented where the device has been used to create physical data for use in change detection and deterioration studies. In addition, a demonstration is presented of the device’s ability to physically simulate a large-scale orifice viscous damper, commonly used in vibration mitigation in bridges and buildings. For a large-scale viscous damper, physical testing is required to ensure structural design properties. However, due to the large scale of the dampers, expensive dynamic loading tests can be carried out at a very iii limited number of facilities. Using the reconfigurable test setup, the dynamic signature of the large-scale viscous damper can accurately be simulated with pre-collected data. The development of a system capable of emulating the restoring force of a nonlinear device with software is a novel approach and requires further calibration for increased reliability and accuracy. A discussion regarding the challenges faced when developing the methodology is presented and possible solutions are recommended. The methodology introduced by this apparatus is very promising. The device is a valuable experimental tool for researchers and designers, allowing for physical data collection, modeling, analysis, and validation of a wide class of nonlinear phenomena that commonly occur in a wide variety of engineering applications

The Networked Naturalist: Mobile phone data collection for citizen science and education

*Background/Question/Methods*
Citizen science projects engage individual volunteers or groups to observe, measure, and contribute data to scientific studies. CENS is building a collection of mobile phone and web-based tools to make the citizen scientist experience more engaging and flexible. CENS is an NSF-funded Information and Technology Center that employs graduate students from Computer Science and Electrical Engineering at UCLA to create open-source software that is environmentally and socially responsible. The overarching goal of the Networked Naturalist project is to enhance participatory learning experiences through citizen science campaigns and help transform the associated learning process. We are collaborating with national field campaigns, such Project BudBurst, and also with the National Park Service to increase participation and retention in citizen scientist campaigns through two main avenues afforded by the use of new technologies: (1) to offer new methods for data collection, primarily using mobile phones, through text, picture, and smart-phone applications, and (2) to provide immediate feedback and automated, engaging analysis of data for informal learning opportunities. We are working to create a robust data collection system to enhance citizen science by ensuring data quality and improving data submission, and to transform participation into an active learning, engaging experience.

*Results/Conclusions*
Our experience with volunteers for software testing at UCLA and at the National Park Service has indicated that using mobile phones is an efficient method for collecting environmental and location data and raises public awareness of environmental issues through attracting the attention of the mass media. Individual participation in the What’s Invasive! project by volunteer citizen scientists seems to have been limited by smartphone application availability (iPhone app is currently only available for Santa Monica), although methods for making observations based on text and picture messaging are also available. We have found that running short-term "campaigns" partnered with NPS officials and groups such as schools has been the most effective in not only education-related efforts but also in efficiently identifying and locating species and objects of interest using mobile phones

Qualitative software engineering research -- reflections and guidelines

Researchers are increasingly recognizing the importance of human aspects in software development and since qualitative methods are used to, in-depth, explore human behavior, we believe that studies using such techniques will become more common. Existing qualitative software engineering guidelines do not cover the full breadth of qualitative methods and knowledge on using them found in the social sciences. The aim of this study was thus to extend the software engineering research community's current body of knowledge regarding available qualitative methods and provide recommendations and guidelines for their use. With the support of an epistemological argument and a literature review, we suggest that future research would benefit from (1) utilizing a broader set of research methods, (2) more strongly emphasizing reflexivity, and (3) employing qualitative guidelines and quality criteria. We present an overview of three qualitative methods commonly used in social sciences but rarely seen in software engineering research, namely interpretative phenomenological analysis, narrative analysis, and discourse analysis. Furthermore, we discuss the meaning of reflexivity in relation to the software engineering context and suggest means of fostering it. Our paper will help software engineering researchers better select and then guide the application of a broader set of qualitative research methods.Comment: 30 page

Case Studies in Industry: What We Have Learnt

Case study research has become an important research methodology for exploring phenomena in their natural contexts. Case studies have earned a distinct role in the empirical analysis of software engineering phenomena which are difficult to capture in isolation. Such phenomena often appear in the context of methods and development processes for which it is difficult to run large, controlled experiments as they usually have to reduce the scale in several respects and, hence, are detached from the reality of industrial software development. The other side of the medal is that the realistic socio-economic environments where we conduct case studies -- with real-life cases and realistic conditions -- also pose a plethora of practical challenges to planning and conducting case studies. In this experience report, we discuss such practical challenges and the lessons we learnt in conducting case studies in industry. Our goal is to help especially inexperienced researchers facing their first case studies in industry by increasing their awareness for typical obstacles they might face and practical ways to deal with those obstacles.Comment: Proceedings of the 4th International Workshop on Conducting Empirical Studies in Industry, co-located with ICSE, 201

Understanding software development: Processes, organisations and technologies

Our primary goal is to understand what people do when they develop software and how long it takes them to do it. To get a proper perspective on software development processes we must study them in their context — that is, in their organizational and technological context. An extremely important means of gaining the needed understanding and perspective is to measure what goes on. Time and motion studies constitute a proven approach to understanding and improving any engineering processes. We believe software processes are no different in this respect; however, the fact that software development yields a collaborative intellectual, as opposed to physical, output calls for careful and creative measurement techniques. In attempting to answer the question "what do people do in software development? " we have experimented with two novel forms of data collection in the software development field: time diaries and direct observation. We found both methods to be feasible and to yield useful information about time utilization. In effect, we have quantified the effect of these social processes using the observational data. Among the insights gained from our time diary experiment are 1) developers switch between developments to minimize blocking and maximize overall throughput, and 2) there is a high degree of dynamic reassignment in response to changing project and organizational priorities. Among the insights gained from our direct observation experiment are 1) time diaries are a valid and accurate instrument with respect to their level of resolution, 2) unplanned interruptions constitute a significant time factor, and 3) the amount and kinds of communication are significant time and social factors.- 2-1

Efficiency Evaluation Of Implementation Of Optimization Methods Of Operation Modes Of The "Plast - Gas Pipeline" System By The Methods Of Mathematical Modeling

To date, Ukraine's mature gas fields, which are being developed in the gas regime, are at the final stage of development, which is characterized by a significant depletion of reservoir energy. The final stage of development requires solving complex problems related to watering wells, destruction of the reservoir, removal of formation water and mechanical impurities, increasing back pressure in the system, as well as the moral and physical wear and tear of industrial equipment. In the conditions of falling gas production, a significant part of the operating well stock is unstable, in the mode of unauthorized stops due to the accumulation of liquid at the bottom and insufficient gas velocities for removal to the surface, and also the accumulation of the liquid phase in the lowered places of the gas gathering system.Within the framework of the conducted studies, the gas dynamic models of the operation of the gas collection system of 3 oil/gas-condensate fields (OGCF) are created. A single model of the gas production system "reservoir - well - gas gathering system - inter-field gas pipeline - main facilities" is built. The current efficiency of the gas production, collection and transportation system is assessed. On the basis of model calculations, the current production capabilities of the wells are defined, as well as the "narrow" places of the system.It is established that the introduction of modern technologies for the operation of watered wells without optimizing the operation of the entire gas production system is irrational, since the liquid that is carried out from the wellbore will accumulate in the plumes and increase the back pressure level in the ground part. In conditions of increasing gas sampling, liquid flowlines can be taken out of the loops and deactivated the separation equipment.The feasibility of introducing methods for optimizing the operation modes of the gas production - gathering and transportation system is estimated, which allows choosing the optimal method for increasing the efficiency and reliability of its operation.For the first time in the Ukrainian gas industry, an integrated model of the field is created as a single chain of extraction, collection, preparation and transportation of natural gas, which can be adapted for the development and arrangement of both new and mature deposits.The main advantage of the application for the hydrocarbon production sector is the simulation of the processes, which makes it possible to evaluate the operating mode of the well in the safe zone while reducing the working pressure and introducing various intensification methods, and also to estimate the increase in hydrocarbon production. For the equipment of the ground infrastructure – "midstream" – the main advantage is a reduction in the time required to perform design calculations for gas pipelines, trains and pipelines for transporting multiphase media using public models.The creation and use of integrated models of gas fields gives an understanding of the integral picture of available resources and ensures an increase in the efficiency of field development management.The results of the calculation are clearly correlated with the actual data, which makes it possible to use the models constructed to obtain numerical results

Gamification in higher education and stem : a systematic review of literature

In recent years, gamification, the use of game elements in non-game contexts, has drawn the attention of educators due to the possibility of making learning more motivating and engaging; this led to an increase of research in the field. Despite the availability of literature reviews about gamification and its effects, no work to this date has focused exclusively on Higher Education (HE). Next, worldwide there is an increasing demand for skilled Science, Technology, Engineering and Mathematics (STEM) professionals that meet the challenges related to scientific and technological innovations of the 21st Century. This lead to the need of strengthening STEM Higher Education. This brings us to the purpose of this work: presenting a systematic literature review of empirical studies about gamification STEM related Higher Education. This review study started from a systematic mapping design of 'Web of Science' articles, with following inclusion criteria: empirical gamification studies set up in HE, published between 2000 and 2016; focusing on undergraduate or graduate students; in the STEM knowledge field, and set up in authentic settings. An initial search resulted in 562 potentially relevant articles. After applying all selection criteria, only 18 studies could be retained. 12 additional articles were included by analyzing references from earlier literature reviews, resulting in 30 studies to be included. Analysis results show how a combination of game elements (e.g. leaderboards, badges, points and other combinations) positively affects students' performance, attendance, goal orientation and attitude towards mostly computer science related subjects. The analysis results also point at a lack of studies in certain STEM areas, a lack of studies that identify the particular game element associated with the positive differential impact on student performance; a lack of validated psychometric measurements, and lack of focus on student variables that could/should be taken into account as mediating/moderating variables clarifying the impact of gamification in the HE focus on STEM learning and teaching