723 research outputs found
3D flow organization and dynamics in subsonic jets: Aeroacoustic source analysis by tomographic PIV
No full textTo meet the increasingly stringent noise regulation, aircraft manufacturers are searching for solutions to jet noise. This, which constitutes a significant amount of the total noise emitted by civil aircrafts, is generated by the mixing processes between the exhaust flow leaving the engine and the atmosphere. A detailed understanding of such mixing process is of paramount importance to identify mechanisms responsible for noise production, i.e. the aeroacoustic source, and, ultimately, to develop noise control strategies. This thesis proposes an unprecedented experimental-based approach to visualize and measure the aeroacoustic sources in jet flows. Time-resolved tomographic particle image velocimetry (TR-TOMO PIV) is employed to obtain time-dependent three-dimensional (3D) measurements of the turbulent flow patterns, while the instantaneous aeroacoustic source is explored using Powell’s aeroacoustic analogy. TR-TOMO PIV experiments are conducted in a tailored jet facility. Measurements are performed both on jets issued through circular and 6-chevron nozzles, with the latter configuration that is nowadays used in jet engines to reduce acoustic emissions. The attention is placed upon the 3D organization and dynamics of flow transition, where coherent flow structures play a role in the generation of noise. The full 3D approach enables unambiguous descriptions of the vortex topology, while the temporal resolution allows addressing the growth and development of the coherent flow structures along with their mutual interaction. In the circular jet, the characteristic pulsatile motion of vortex ring shedding and pairing is accompanied by the growth of azimuthal instabilities and the formation of streamwise vortices leading to the breakdown of the vortex rings. In the chevron jet, instead, the axisymmetric ring-like coherence is replaced by streamwise flow structures whose decay is accompanied by the formation of C-shaped structures. The relation between coherent structures and the instantaneous acoustic source is investigated recalling Powell’s aeroacoustic analogy, with the acoustic source that is identified by the second time derivative of the Lamb vector. The spatio-temporal evolution of the source is mapped and is compared to that of the vortices, to detect flow events involved in the acoustic generation. In the circular jet, most pronounced source activity is observed during the vortex-ring breakdown, whereas, in the chevron configuration, is associated with the process of streamwise vortex decay and C structure formation. Performing unbiased acoustic predictions of the jet noise with TR-TOMO PIV measurements is a challenging task due to the constraints on the extent of the instantaneous measurement domain and on the required spatial and temporal resolutions. To meet this challenge, the thesis finally proposes a strategy to perform far-field acoustic predictions by direct evaluation of Powell’s analogy using TR-TOMO PIV data.AerodynamicsAerospace Engineerin
Empowering end-users in the energy transition: An exploration of products and services to support changes in household energy management
No full textCurrent discourse on smart grid deployment expects residential end users to play a more active role as co-providers in the electric power system. Their electricity consumption and production is considered a resource for balancing supply and demand in an electric power system with distributed generation. This means that, in addition to using energy efficiently, they, for example, have to adjust their consumption patterns to the production patterns of locally available and intermittent energy generation. This thesis explores how the technological and social contexts of smart grids can shape the role of residential end-users as co-providers in the electric power system. The main objective was to formulate implications for the development of products and services that support end-users in taking up a co-provider role. The research involved a literature review about currently applied smart grid technologies and field studies of two pilot projects in which households were equipped with smart energy technology: Energy Battle and PowerMatching City. Both cases concern the implementation of a product-service combination that was new for the household and that was aimed at enabling one or more aspects of co-providing end-user behavior. End-users’ experiences in using the implemented system were central to the research in each case. The research resulted in design implications within four themes: (1) Design of the user interface, (2) Design in relation to the social context at household and community level, (3) Integral design approach to address behavioral and technical aspects of smart energy system performance, and (4) Design of products and services as part of an experiential learning process for both developers and end-users.Design Engineering / Design for SustainabilityIndustrial Design Engineerin
Standard and non-standard neutrino physics at reactor experiments
No full textIn parallel to the standard oscillation physics program it is well known multi-detector reactor neutrino experiments are able to probe new physics scenarios, for instance, new oscillation phases driven by an extra light sterile neutrino and new neutrino interactions (NSI). Here we review and update the flavor non-universal and flavor universal constraints on the charged-current NSI parameters. We also study correlations between the NSI and the standard parameters. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0)
Designing awareness systems for social connectedness – A field study approach into theoretical foundations, design principles and evaluation
No full textBeing in touch, and being aware of the people in one’s social network strongly contributes to one’s sense of social well-being. As communication technology has become more ubiquitous, it is possible to always be in touch with friends and relatives in the periphery of one’s attention, e.g. through instant messaging and online social networks. This research investigated the effect of such social information on people’s sense of connectedness. Also, it was studied how such communication application can be integrated into the fabric of our everyday life as awareness systems. It was found that despite the subtlety, mediated social awareness has a measurable effect on social connectedness. Also, the findings strongly suggest that ambiguity in social cues is a strong enabler of the feeling of being connected. These findings may help designers of social network applications and products to more effectively design for increased social connectedness.Industrial DesignIndustrial Design Engineerin
Curriculum “Algebra. Grade 7” for general secondary education institutions, working on the model curriculum Algebra 7-9 by the author team of M.I. Burda, N.A. Tarasenkova, D.V. Vasylieva
No full textНавчальна програма «Алгебра. 7 клас» для закладів загальної середньої освіти створена для закладів, що працюють за модельною навчальною програмою Алгебра 7-9 авторського колективу Бурда М.І., Тарасенкова Н.А., Васильєва Д.В. та підручниками авторів Бевз та ін. (Б) / Тарасенкова та ін. (Т).The curriculum “Algebra. Grade 7” for general secondary education institutions is designed for institutions working on the model curriculum Algebra 7-9 by the author's team of Burda M.I., Tarasenkova N.A., Vasyliev D.V. and textbooks by the authors Bevz et al (B) / Tarasenkova et al (T)
Design framework for developing ict products and services for rural development: A persuasive health information system for rural India
No full textInformation poverty cannot be addressed by simply giving away computers and installing internet connections in rural areas. What is really needed is to offer rural users relevant, personalized information that enables them to make positive changes in their daily lives, rather than give them the type of information that is typically available via public internet sites. ICT should be viewed as a tool, and not as the solution to building knowledge-based societies. ICT encompasses the full range of information and communication technologies, including radio, television and print media as well as the ever-expanding array of computer hardware and software, telecom devices, internet and portable digital media. To build a knowledge-based society, many organizations and enterprises have given rise to a range of innovative projects and services. These innovative projects attempt to use ICT to enable rural users to access relevant information services with a view to ultimately reducing information poverty. Where information poverty can be understood as a lack of knowledge to make decisions to improve wellbeing in terms of economic and social development. Information services have been offered in crosscutting sectors such as education, e-governance, agriculture, and healthcare. Reducing information poverty through the use of ICT to improve user wellbeing is a major challenge for governmental and non-governmental organizations alike. Several new media ICT interventions such as Telecenters that offer e-services in domains such as agriculture, healthcare, and education have recently been deployed in India. Despite huge investment in recent efforts to address information poverty via new media ICT interventions, the results still do not make a convincing case for solving the information poverty problem. Consequently, there is still an information gap between rural users and the information offered via ICT interventions. The case study evaluation of ICT interventions deployed in India (Chapter 2) indicated that users have still not adopted the majority of these interventions. The low adoption level of ICT interventions could be attributed to the following key issues: a. The information content offered through the ICT interventions such as, telecenters is often found to be too general to be useful for rural users, and is inadequately disseminated. Existing ICT interventions are focused on introducing new applications and technologies to the rural market rather than on having a concrete understanding of user needs and the social environment. The term social environment of an individual can be understood as the culture that he or she was educated and/or lives in, and the people and institutions with whom the person interacts. The information offered via the ICT interventions on a particular topic, such as healthcare or agriculture, does not often take into consideration the existing information needs, daily practices, and the needs of the social environment of the rural communities. As a consequence, rural users do not see that the information given has any added value in their life. b. The sustainability of ICT interventions in a rural context is dependent on knowledge from several scientific disciplines such as, for example, social science for understanding societal issues at community and individual level; computer science for developing the software and hardware of an interactive device; industrial design for designing the user-interface and for usability testing; marketing for addressing issues of economic sustainability and technology adoption. However, the current development approaches are often dominated by a single discipline, namely - the technology development groups. This approach often leads to technology-centered development. Recent literature on ICT development discusses the need for a developmental framework to achieve sustainable ICT solutions (Chapter 3). As an answer to this call, several frameworks have recently been proposed by researchers and organizations involved in promoting ICT for rural development. These frameworks focus mainly on organizational issues, such as how an organization can improve its efforts regarding the design and implementation of ICT interventions in developing countries. However, none of the ICT development frameworks have taken a bottom-up approach, where it is the users who drive the problems and solutions. In particular, these frameworks fail to incorporate user needs, the socio-cultural context, and technological viability issues in the early development phase. Design can play a critical role towards developing a framework to support ICT development for rural communities. Design can address the developmental issues towards holistically improving information dissemination via ICT interventions, thereby achieving a high rate of adoption. Towards proposing a design framework for developing ICT products and services for rural development, this thesis dealt with finding the answers to the following two research challenges: The first research challenge was to incorporate knowledge from multiple disciplines in the user-centered design approach to develop sustainable ICT interventions. To meet this objective, a case study analysis was first conducted to understand where existing ICT development approaches succeed or fail (see Chapter 2). The findings from the case study analysis provided requirements for the design framework to support ICT development for rural communities. Based on the requirement for the framework, this thesis put forward a design framework that amalgamates theories from multiple disciplines such as social sciences, computer science, industrial design and marketing management, and involves different stakeholders to support the main stages in the user-centered development process (see Chapter 3). The design framework consists of two main components: Component A includes the user-centered phases of the design cycle. The three stages of the usercentered development process in the proposed design framework have been termed: Exploratory Research, Creative Design Research, and Evaluative Research. Component B, the theoretical framework, explains the theories from multiple disciplines that have been adapted to guide the development process followed in component A. Both these components were interlinked with each other where component B provided the theoretical foundation to the various stages in the user-centered process as defined in component A (see Chapter 3). The second research challenge was to design and develop ICT interventions for socially complex environments in order to improve information dissemination and increase user-adoption of ICT intervention. As a development case, an ICT intervention focusing on disseminating primary health information to rural women was developed by following the proposed design framework. Following the exploratory phase of the design framework, field studies were then conducted in Gujarat, India. The purpose of the field studies was to obtain baseline data on user needs and to understand the socio-cultural norms of rural women surrounding their health practices, and to investigate the knowledge level of rural women relating to menses and maternal health (see Chapter 4). Chapter 4 describes the exploratory research phase of the proposed design framework. This phase included two studies (1 and 2) conducted with the baseline group (rural women) and potential stakeholders in the pilot villages of Gujarat, India. The studies were conducted to identify the existing knowledge level (baseline survey) and the social beliefs and practices of rural women relating to menses and maternal health. The theory of planned behavior was adopted in the exploratory stage as a means to understand the social norms and user needs for developing an ICT intervention. The questionnaire used was based on the three factors of the theory of planned behavior that affect human action: Attitude toward the Behavior, Subjective Norm, and Perceived Behavioral Control. The results from studies 1 and 2 indicated that the knowledge level of rural women on matters relating to menses and maternal health was low. The results illustrate that there exist social beliefs and health practices that inhibit the acceptance of good health practices relating to menses and maternal health. We concluded from the exploratory stage that, in order to improve the knowledge level of rural women, the social beliefs and practices as identified need to be positively shaped. This implies that in ICT development, besides understanding the social beliefs and attitudes of the target user group, it is critical to incorporate them in the design of nformation content and the physical environment. The PHIS was developed as a part of the creative design phase of the proposed design framework (Chapter 5). The PHIS design integrates theories from multiple disciplines, such as social cues from persuasive technology, and the theory of planned behavior for shaping the social beliefs and health practices of rural women. Concept 1 of the PHIS was developed on the basis of the design requirements obtained in the exploratory phase (Chapter 4). The design and development process employed persuasive technology in designing information communication strategies, the physical environment, and the physical system design of the PHIS. The role of persuasive technology was to shape existing social norms via an interactive system and to motivate the rural women to have a high behavior intention, thereby increasing their perceived behavior control. The PHIS used a computer as a tool, a medium, and a social actor to create a persuasive interactive experience for the rural women to shape their social beliefs. Social cues from persuasive technology such as physical cues, language cues, psychological cues, social dynamics, and social roles were applied in the PHIS for shaping social beliefs and the health attitude of rural women in India. Studies 3 & 4 were conducted to evaluate the first concept of the PHIS. Firstly, an initial impact study (study 3) was conducted to compare user engagement between the PHIS (village B) and the local NGO-health information system (village A). Results from the comparative study reported an increase in user engagement with the PHIS compared with the NGO health system (see Chapter 5). The results showed an increase in the number of revisits and in the number of questions asked by the rural women using the PHIS compared with the NGO system. Secondly, an evaluative study (study 4) was conducted to evaluate the PHIS on the basis of Rogers innovation attributes from diffusion theory. Feedback from rural women was collected against four product innovation attributes: Relative, Advantage, Compatibility, Complexity, and Observability. The women using the PHIS reported high values against the four innovation attributes. For example, the PHIS gave them privacy and the freedom to access health information. Therefore, the rural women ranked it high on the “relative advantage” attribute compared with the NGO system. We concluded from studies 3 & 4 that applying social cues from persuasive technology in designing the form, content and interaction of the PHIS can positively shape the social beliefs of the users. For example, to incorporate psychological cues from persuasive technology in the PowerPoint slides, three animated characters representing local identities were used to convey the relevant messages. These characters represented the main characters found in the village community, and included (a) a teenage girl for discussing menses issues; (b) a married woman for discussing maternal issues; and (c) a doctor for answering the queries. Traditional folk music and puppet shows were used to convey the stories woven around these characters. In all six categories, the three characters presented existing beliefs through cases and discussed their effects rationally. It can be concluded from the results that by offering belief-based content the health information dissemination process can be improved and hence user engagement. The findings from the creative design phase informed the design of Concept 2 of the proposed ICT intervention termed the Mobile Persuasive Health Information System (MPHIS) (see Chapter 6). Concept 2, the MPHIS was designed to make the PHIS mobile and enhance social interaction by using traditional metaphors in the user interface design. The results from the MPHIS evaluative study (Study 5) illustrated increased social interaction as a result of enhanced product engagement, product attachment, and increased community decision-making. As a consequence of increased social interaction, sensitive health information relating to menses and maternal health was easily disseminated to the rural women. The reflection of traditional metaphors on design reduced the technology barrier prevalent among rural women, and therefore increased their engagement when interacting with the MPHIS. Furthermore, because the MPHIS was mobile, rural women from remote villages could also access the system, which was previously not possible with the PHIS. We concluded from Study 5 that by adapting traditional metaphors to design the Tangible User Interface (TUI), a personalized relationship between the interactive system and the user can be developed. This allows even those users with limited exposure to technology to access the relevant information independently. As part of the evaluative research, we measured the impact of the PHIS intervention on the knowledge level and health practices relating to menses and maternal health of rural women. In this thesis, an increase in knowledge level and the positive change in heath practices among rural women has been considered to be an indicator of a high rate of adoption of the PHIS intervention (see Chapter 3). In order to investigate the rate of PHIS adoption, a longitudinal study (Study 6) was conducted for sixteen months (see Chapter 7). The purpose of this study was to investigate the changes in the knowledge level of rural women and in their health practices relating to maternal health and menstruation between the village in which the women received no intervention (baseline group) and the village in which women received the PHIS intervention (intervention group). The results from Study 6 between the baseline group and intervention group indicated the difference in knowledge level of rural women who did and did not receive the intervention. The results from the longitudinal study indicated that the PHIS intervention had a positive impact on improving the knowledge level of rural women and brought about positive changes in their health practices. The data from the control group indicated that the improvement in knowledge level determined from the comparison between the intervention and baseline groups was not influenced by any external factors. The results from the longitudinal study indicate a positive impact of the PHIS intervention in improving the knowledge level of rural women. The follow-up observation conducted by the PHIS operators and community health workers revealed positive changes in the daily health practices of rural women. These changes were mainly observed in the disposal of menstrual cloths, maintaining personal hygiene, nutritional habits and delivery practices. For example, after the PHIS intervention, the women learned that it was possible to burn used cloths in their backyard. It was observed that (n=82/120) rural women adopted this new practice. Previously the used cloth had been stored in an unhygienic place and was not dried in the open in the sun because rural women did not understand that menstruation was simply a normal biological process. After accessing health information from the PHIS, (n=42/120) rural women reported that they changed the cotton cloths every two months, and that they dried them in the sun to sterilize them. These results could be attributed to the fact that the content was dynamically updated by the operators in accordance with the information needs and existing health practices of the rural women. The results from Study 6 lead to the conclusion that the necessary information relating to personal health that is consistently reinforced and is in compliance with existing social beliefs and practices may lead to a change in health-related practices. Disseminating information specifically designed for women, and through an intervention that engages them to interact in groups to discuss their personal health issues, may lead to positive changes in their health practices. Additionally, we conclude that information that directly adds value to the participant’s daily life may have a positive influence on the rate of adoption of ICT intervention. Key findings and implications from the various studies conducted during this research are reported on in Chapter 8 which discusses in particular the relevance of organizing multi-disciplinary collaboration in the design process of ICT development, the need to investigate existing social beliefs and practices, and issues surrounding stakeholder involvement and capacity development in ICT interventions. I have made an attempt with this thesis to demonstrate the strength of industrial design as a discipline to address socially complex problems in the rural context. In order to shape the social beliefs and health practices of rural women, two persuasive health information systems were developed by following the proposed design framework. However, I am aware of the fact that it is too soon to generalize or to judge the reliability of this framework in terms of guiding user-centered ICT development. The design framework still needs to be rigorously tested when designing other ICT projects deployed in a rural context, such as e-governance, distant education, and tele-medicine services. In terms of testing the reliability of the proposed design framework, the spinoff project from this thesis -called “Savera” -will follow the three phase design framework and we expect to draw some general lessons from this experience. This thesis should be considered as an example of how a bottom-up approach that involves users in the content development and the design process could lead to user-centered ICT developments for the rural context.Industrial DesignIndustrial Design Engineerin
A pattern language of firefighting frontline practice to inform the design of ubiquitous computing
No full textDesigning computing systems for frontline firefighting is an open challenge. As of today, little computing support exists for such hazardous environments and designers struggle to build appropriate systems that fit the complex configuration on the frontline. Following Christopher Alexander’s understanding, design is about producing living transformations of existing configurations, it requires a thorough understanding of the situation on-site. Alexander introduces pattern languages as a means to describe existing configurations and to make them accessible for design, to link ethnography and design. This thesis therefore develops a pattern language of firefighters’ activities at the frontline to transform the existing practice into a design space for computing support. Grounded theory, as a qualitative method to identify patterns in empirical data, and action research, as a framework that allows studying the interaction between new technologies and existing practice, solidify the methodology of pattern research and are applied to conduct and analyze workshops with French and German firefighters at professional training facilities. Workshops comprise the observation of existing practice, the active participation in firefighting exercises and the introduction of novel artifacts. Linked up as a pattern language, 16 patterns describe the configuration of frontline firefighting. The patterns detail how firefighters organize the division of roles and tasks, how they deal with information in a dynamic environment, how they form a social binding, improvise, provide safety and prepare their work. While similar individual patterns have been described for firefighting and other high reliability professions, the pattern language, beyond these aspects, provides an integrated perspective on the frontline work; it allows developers to reflect technological concepts and supports the participatory design process of ubiquitous computing systems.Industrial DesignIndustrial Design Engineerin
Help Me Help You. Designing Support for Person-Product Collaboration
No full textThis thesis explores how to make appliances, such as thermostats, televisions and microwave ovens, easier to program. It does so by looking at person-product interaction as a type of collaborative planning dialogues. The user and product must âtalkâ to each other, engaging in a collaborative dialogue that can lead to a shared plan concerning their mutually held beliefs and goals. The design challenge discussed in this thesis centers on the creation of product interfaces that facilitate collaborative person-product planning. In particular, a product interface should capitalize on the complementary strengths of the person and product: the product's ability to interpret user actions and goals and make efficient plans to achieve them, and the person's knowledge of what he or she wants to do. This goal is captured in the Help Me Help You (HMHY) principle, namely that a programmable product interface needs to be designed to help the user to better help the product know what the user wants to do, and thus better able to help the user. In other words, programmable appliance interfaces need to be designed to support person-product collaboration. The research question addressed in this thesis is how to develop a practical design method for supporting person-product collaboration from existing models of collaboration discourse. The design research in this thesis focused on the 'Some Things To Say (SenSay)' a modular adaptive menu derived from task models using collaborative discourse theory. The questions of how to design the SenSay from the theory and how people actually use it to get things done, as well as new methods for exploring and evaluating SenSay design, are all addressed across the different chapters of this thesis.Design, Engineering and Productio
Hierarchical coarsening of simulation model for in-situ upgrading process
No full textOil shales are sedimentary rocks containing organic matter in the form of Kerogen which accounts for more than 5 trillion barrels of oil in place according to Birol, 2010; therefore, oil shales represents a plausible solution for the constantly increasing demand for hydrocarbons. Oil shale production is currently done using two different techniques, surface retorting and in-situ retorting. The last one being the focus of this study. During this process, the sedimentary rock containing the kerogen is brought into a high-temperature environment with oxygen deficit. At this stage, the organic matter is subject to a thermo-chemical decomposition that finally releases the hydrocarbon in liquid and gas forms. This process is also known as pyrolysis. During this process, solid and fluid components experience compositional and physical changes, which requires complex chemical models represented by multiple species and several governing relations. In this work, we first developed a numerical solver for closed systems with simple kinetics models. This initial work allowed us to analyze the dynamic behavior of each component during the chemical decomposition of the kerogen and its impact in the porosity of the system. Then, we described an accurate base model for chemical decomposition of kerogen. This model was then implemented in our in house simulator ADGPRS. The model is based on the most recent understanding of pyrolysis process, and it incorporates coupling of chemical kinetics to heat and mass transport. Due to the high number of species, variations of porosity as consequence of the transformation of solid species into fluid products and complex multi-scale structure of porous media, the simulation performance of the high-fidelity model is limited. Therefore, in the second step of this work, we introduce a hierarchy of coarser models to improve the run-time of forward solution without significant reduction in accuracy. We applied coarsening in time, space, and chemical representation, and quantify errors introduced at each coarsening level. In conclusion, we provided recommendations for large-scale modeling of in-situ upgrading process.Civil Engineering and GeosciencesGeoscience & EngineeringPetroleum Engineerin
Modeling and Upscaling of Shale Gas Using a Discrete Fracture Modeling Approach
No full textGas flow in fractured nano-porous shale formations is complicated by a hierarchy of structural features, ranging from nanopores to microseismic and hydraulic fractures, and by several transport mechanisms that differ from standard viscous flow used in reservoir modelling. In small pores, self-diffusion becomes more important than advection, also slippage effect and Knudsen diffusion becomes relevant at this scale. The characteristics and properties of the fracture networks plays a major role in the performance of shale gas reservoirs, therefore the use of accurate simulation technique that honor the complexity of these reservoirs and capture the associated dynamics of nanopores is strongly required. However, these accurate simulations often necessitate a large amount of computations for field scale models and therefore require upscaling. Yet the upscalling techniques generally in use are based on idealizations that do not reflect the discrete features of the reservoir. In this work, we first incorporate the formulations of a statistical bundle of dual tube model to describe the dynamics of shale gas into a discrete fracture model. The formulation of the DFM model we use applies an unstructured control volume finite difference approach with a two point flux approximation. We then propose to upscale these detailed descriptions using two different techniques, with the major difference in their coarse grid geometry. The first approach, referred to as EDFM upscaling, relies on a structured Cartesian coarse grid. While the second method, which we call the multiple subregion (MSR) upscaling, introduces a flow based coarse grid to replicate the diffusive character of the pressure in the matrix. The required parameters for the coarse scale model in both methods and the geometry of the subregions in the second method are determined efficiently from global single-phase flow solution using the underlying discrete fracture model. The methods are applied to simulate single-phase gas flow in 2D fractured reservoir models, and are shown to provide results in close agreement with the underlying DFM and with considerable reduction in the computational time. We notice that in order to account for the prevailing transient effects in low permeability shale, the upscaled transmissibility need to be related to pressure for better results. Finally, we consider the EDFM upscaling we propose as an easier approach in its implementation, while the MSR technique as a more accurate method.Civil Engineering and GeosciencesGeoscience & Engineerin
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