1.
Fredenberg, Erik, 1979-
(author)
Spectral Mammography with X-Ray Optics and a Photon-Counting Detector
2009
Doctoral thesis (other academic/artistic) abstract
Early detection is vital to successfully treating breast cancer, and mammography screening is the most efficient and wide-spread method to reach this goal. Imaging low-contrast targets, while minimizing the radiation exposure to a large population is, however, a major challenge. Optimizing the image quality per unit radiation dose is therefore essential. In this thesis, two optimization schemes with respect to x-ray photon energy have been investigated: filtering the incident spectrum with refractive x-ray optics (spectral shaping), and utilizing the transmitted spectrum with energy-resolved photon-counting detectors (spectral imaging). Two types of x-ray lenses were experimentally characterized, and modeled using ray tracing, field propagation, and geometrical optics. Spectral shaping reduced dose approximately 20% compared to an absorption-filtered reference system with the same signal-to-noise ratio, scan time, and spatial resolution. In addition, a focusing pre-object collimator based on the same type of optics reduced divergence of the radiation and improved photon economy by about 50%. A photon-counting silicon detector was investigated in terms of energy resolution and its feasibility for spectral imaging. Contrast-enhanced tumor imaging with a system based on the detector was characterized and optimized with a model that took anatomical noise into account. Improvement in an ideal-observer detectability index by a factor of 2 to 8 over that obtained by conventional absorption imaging was found for different levels of anatomical noise and breast density. Increased conspicuity was confirmed by experiment. Further, the model was extended to include imaging of unenhanced lesions. Detectability of microcalcifications increased no more than a few percent, whereas the ability to detect large tumors might improve on the order of 50% despite the low attenuation difference between glandular and cancerous tissue. It is clear that inclusion of anatomical noise and imaging task in spectral optimization may yield completely different results than an analysis based solely on quantum noise.
2.
Amundin, Mats, et al.
(author)
A proposal to use distributional models to analyse dolphin vocalisation
2017
In: Proceedings of the 1st International Workshop on Vocal Interactivity in-and-between Humans, Animals and Robots, VIHAR 2017. - 9782956202905 ; , s. 31-32
Conference paper (peer-reviewed) abstract
This paper gives a brief introduction to the starting points of an experimental project to study dolphin communicative behaviour using distributional semantics, with methods implemented for the large scale study of human language.
3.
4.
Schötz, Susanne, et al.
(author)
Phonetic Characteristics of Domestic Cat Vocalisations
2017
In: Proceedings of the 1st International Workshop on Vocal Interactivity in-and-between Humans, Animals and Robots, VIHAR 2017. - 9782956202905 ; , s. 5-6
Conference paper (peer-reviewed) abstract
The cat (Felis catus, Linneaus 1758) has lived around or with humans for at least 10,000 years, and is now one of the most popular pets of the world with more than 600 millionindividuals. Domestic cats have developed a more extensive, variable and complex vocal repertoire than most other members of the Carnivora, which may be explained by their social organisation, their nocturnal activity and the long period of association between mother and young. Still, we know surprisingly little about the phonetic characteristics of these sounds, and about the interaction between cats and humans.Members of the research project Melody in human–cat communication (Meowsic) investigate the prosodic characteristics of cat vocalisations as well as the communication between human and cat. The first step includes a categorisation of cat vocalisations. In the next step it will be investigated how humans perceive the vocal signals of domestic cats. This paper presents an outline of the project which has only recently started.
5.
Stolen, Reidar, et al.
(author)
Solcelleteknologi og brannsikkerhet
2018
Reports (other academic/artistic) abstract
Bruken av solcelleteknologi er i stor vekst i Norge. I denne studien er branntekniske utfordringer ved bruk av solcelleteknologi undersøkt, med hensyn på brannstart, brannspredning og brannslokking. Studien danner et kunnskapsgrunnlag for å ivareta brannsikkerheten under montering, drift og under slokkeinnsats, samt for å utforme et enhetlig og tydelig regelverk. Resultatene fra studien viser:Brannstart: Solcelleinstallasjoner inneholder mange koblingspunkt, som kan være potensielle tennkilder, og en liten mengde brennbare materialer. Dermed er det som trengs til stede for å starte en brann. Det er viktig at alle kontaktpunkter i solcelleinstallasjonen er robuste og tåler den påkjenningen de blir utsatt for gjennom sin levetid uten at det oppstår dårlig kontakt som kan føre til brann.Brannspredning: For utenpåmonterte solcellemoduler er det ofte en åpen luftspalte mellom modul og bygning. Dersom det er en brann i denne luftspalten, vil varmen kunne bli akkumulert, noe som kan føre til raskere og større brannspredning enn om bygningsoverflaten ikke hadde vært tildekket. I fullskalaforsøk med solcellemoduler montert på tak spredte brannen seg under hele arealet som var dekket av moduler, men stoppet da den nærmet seg kanten av dette arealet. Dette illustrerer viktigheten av at områder med solceller utenpå en bygning blir seksjonert for å unngå brannspredning. Eventuelt kan det benyttes mindre brennbare materialer på taket under solcellemodulene for å motvirke den økte varmepåkjenningen som solcellemodulene gir. Luftspalten mellom modul og bygning kan potensielt også gi endringer i luftstrømningen langs bygget, som igjen kan påvirke brannspredningen.Brannslokking: Brannvesenet har behov for informasjon om det er solcelleinstallasjon i bygget og hvilke deler av det elektriske anlegget som kan være spenningssatt. Under slokkeinnsats må brannvesenet ta hensyn til berøringsfare, og fare for at det kan oppstå lysbuer og andre feil som kan føre til nye antennelsespunkt. Ferskvann kan brukes som slokkemiddel, dette må spyles fra minimum 1 meters avstand med spredt stråle og minimum 5 meters avstand med samlet stråle. Solcellemoduler kan komplisere brannslokking ved at de danner en fysisk barriere mellom brannvesenet og brannen, samt fordi det må tas hensyn til plassering av spenningssatte komponenter. Når disse punktene er tatt høyde for, bør ikke utenpåmonterte solcelleinstallasjoner være et problem.Videre arbeid: For utenpåmonterte solcelleinstallasjoner, er det lite forskning på vertikal montering (på fasader), og hvordan en eventuell endret branndynamikk kan påvirke brannspredning og slokking. Videre er det i dag økende bruk av bygningsintegrerte solcelleinstallasjoner, noe som gir mange mulige nye utfordringer for brannsikkerheten og for regelverk, ettersom solcellen da er en del av bygningskroppen, samtidig som den er en elektrisk komponent. Tysk statistikk tyder på at brannrisiko for slike installasjoner kan være større enn for utenpåmonterte solcelleinstallasjoner, og dette vil det derfor være viktig å undersøke nærmere.
6.
Chen, Zhe, et al.
(author)
Nano-scale characterization of white layer in broached Inconel 718
2017
In: Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing. - Amsterdam : Elsevier BV. - 0921-5093 .- 1873-4936. ; 684, s. 373-384
Journal article (peer-reviewed) abstract
The formation mechanism of white layers during broaching and their mechanical properties are not well investigated and understood to date. In the present study, multiple advanced characterization techniques with nano-scale resolution, including transmission electron microscopy (TEM), transmission Kikuchi diffraction (TKD), atom probe tomography (APT) as well as nano-indentation, have been used to systematically examine the microstructural evolution and corresponding mechanical properties of a surface white layer formed when broaching the nickel-based superalloy Inconel 718.TEM observations showed that the broached white layer consists of nano-sized grains, mostly in the range of 20–50 nm. The crystallographic texture detected by TKD further revealed that the refined microstructure is primarily caused by strong shear deformation. Co-located Al-rich and Nb-rich fine clusters have been identified by APT, which are most likely to be γ′ and γ′′ clusters in a form of co-precipitates, where the clusters showed elongated and aligned appearance associated with the severe shearing history. The microstructural characteristics and crystallography of the broached white layer suggest that it was essentially formed by adiabatic shear localization in which the dominant metallurgical process is rotational dynamic recrystallization based on mechanically-driven subgrain rotations. The grain refinement within the white layer led to an increase of the surface nano-hardness by 14% and a reduction in elastic modulus by nearly 10% compared to that of the bulk material. This is primarily due to the greatly increased volume fraction of grain boundaries, when the grain size was reduced down to the nanoscale.
7.
8.
Hosseini Bab Anari, Elham, 1982, et al.
(author)
Fluorine-free salts for aqueous lithium-ion and sodium-ion battery electrolytes
2016
In: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 6:88, s. 6, 85194-85201
Journal article (peer-reviewed) abstract
A first generation of fluorine-free lithium and sodium salts based on the concept of pseudo-delocalized anions has been synthesized with both high purity and yield using water as the solvent in the reaction medium. The salts have been fully characterized by Raman and FT-IR spectroscopies, thermogravimetry, and X-ray crystallography to reveal both basic properties in terms of thermal stability and solubility as well as the local, mainly ion–ion interaction dictated, coordination details and by ionic conductivity and electrochemical stability window measurements as aqueous electrolytes. Together a picture is created of the salts' promise as components in electrolytes – primarily aiming at application in low voltage fluorinefree aqueous lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs).
9.
Stylidis, Kostas, 1978, et al.
(author)
Perceived quality framework in product generation engineering: an automotive industry example
2019
In: Design Science. - : Cambridge University Press (CUP). - 2053-4701 .- 2053-4701. ; 5
Journal article (peer-reviewed) abstract
Perceived quality refers to customers’ cognitive and emotional responses to a particular design, often also associated with craftsmanship and customer satisfaction. Previous research defined a taxonomy of perceived quality and provided understanding about how engineering design decisions impact customer satisfaction. Furthermore, development of new products is frequently based on carrying over attributes of existing products, either from the same producer or from competitors. Previous research offered a new product development methodology combining variations of subsystems to carry over from existing products. This brief presents how these two lines of research combined to design the central console of the Porsche Panamera automobile and discusses the opportunities and challenges posed in the practical implementation of this research.
10.
Ribeiro, Luis, et al.
(author)
Industrial Agents for the Fast Deployment of Evolvable Assembly Systems
2015. - 1st ed.
In: Industrial Agents. - Amsterdam, Netherlands : Elsevier. - 9780128003411 ; , s. 301-321, s. 301-322
Book chapter (peer-reviewed) abstract
The current manufacturing scenario is characterized by high market unpredictability. Agility is therefore a central challenge for modern companies that need to understand and be proactive towards their product offer in respect to “what is offered, when it is offered, where, how and by whom” (Brown & Bessant 2003).The “what” and the “when” are particularly relevant to the research in emerging paradigms as they account for variety, customization and volume; and timing, speed and seasonality (Brown & Bessant 2003).In this scenario, several design approaches and models have been proposed in the last decade to enable re-configurability and subsequently enhance the companies’ ability to adjust their offer in nature and time.From a paradigmatic point of view research has concentrated on the organizational structure of the shop-floor and the associated controls aspects. Concepts like Reconfigurable Manufacturing Systems (RMS) (Koren & Shpitalni 2010) and Fractal Factories (FF) (Montreuil 1999) support the physical construction of production systems by regulating their layout and making a few assumptions on their logical organization. On the other hand, concepts like Bionic Manufacturing Systems (BMS)(Ueda 1992), Holonic Manufacturing Systems (HMS)(Van Brussel et al. 1998), Evolvable Assembly Systems (Ribeiro et al. 2010) essentially provide the theoretical guidelines for the logical/computational organization of the system (see (Tharumarajah 1996) for a comparison between BMS, HMS and FF and (Setchi & Lagos 2004) for the rationale supporting the shift from Dedicated Lines to Flexible Manufacturing System and finally RMS).While these paradigms provide the conceptual framework and the main design guidelines their actual interpretation and implementation has led to a wider set of architectures (Monostori, Váncza & Kumara 2006; Leitão 2009; Parunak 2000; Pěchouček & Mařík 2008).These architectures align the high-level principles with the technological offer and limitations while seeking to address the re-configurability requirements of (Mehrabi, Ulsoy & Koren 2000; Rösiö & Säfsten 2013):module mobility – modules are easy and quick to move and install;“diagnosability” – it is quick to identify the sources of quality and reliability problems;“integrability” – modules are easy to integrate into the rest of the system.“convertibility” – it is easy and quick to switch between existing products and it is easy to adapt the system to future products;scalability – it is easy to enlarge and downsize the production system;“automatibility” – a dynamic level of automation is enabled;modularity – all system elements are designed to be modular;customization – the capability and flexibility of the production system is designed according to the products to be produced in the system.Instant deployment, as addressed in the present chapter directly addresses mobility, “integrability”, “convertibility”, scalability and customization. Mechatronic modularity is a prerequisite and is enforced by the proposed architecture and the considered modular design. “Diagnosability” was not specifically tackled.In this context, the chapter analyses the agent-based architecture related with the Instantly Deployable Evolvable Assembly System (IDEAS) project that is inspired by the Evolvable Assembly System (EAS) paradigm (Ribeiro et al. 2010) as a mechanism to enable fast deployment of mechatronic modules. EAS advocates the use of process-oriented modules and envisions the production system as a collection of processes and the associated interacting agents.The architecture and the related test cases are used to draw the main lessons learned in respect to technological and conceptual implications.In this context, the remainder of this text is organized as follows: section 1.1 discusses the main deployment challenges, section 1.2 details the reference architecture and associated concepts, section 1.3 presents the principal implementation decisions, section 1.4 features the main lessons learned, sections 1.5 discusses the benefits of the proposed approach and finally section 1.6 reflects on the main conclusions.
11.
Eivazihollagh, Alireza, et al.
(author)
On chelating surfactants : Molecular perspectives and application prospects
2019
In: Journal of Molecular Liquids. - : Elsevier BV. - 0167-7322 .- 1873-3166. ; 278, s. 688-705
Journal article (peer-reviewed) abstract
Chelating agents, molecules that very strongly coordinates certain metal ions, are used industrially as well as in consumer products to minimize disturbances and increase performance of reactions and applications. The widely used sequestering agents, nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) belong to this branch of readily water-soluble compounds. When these chemical structures also have hydrophobic parts, they are prone to adsorb at air-water interfaces and to self-assemble. Such bifunctional molecules can be called chelating surfactants and will have more extended utilization prospects than common chelating agents or ordinary ionic surfactants. The present review attempts to highlight the fundamental behavior of chelating surfactants in solution and at interfaces, and their very specific interactions with metal ions. Methods to recover chelating surfactants from metal chelates are also described. Moreover, utilization of chelating surfactants in applications for metal removal in environmental engineering and mineral processing, as well as for metal control in the fields of biology, chemistry and physics, is exemplified and discussed.
12.
Nybacka, Mikael, et al.
(author)
Project: CASTT - Centre for Automotive Systems Technologies and Testing
2007
Other publication (pop. science, debate, etc.) abstract
Through the Centre for Automotive Systems Technologies and Testing, Luleå University of Technology aims to first of all support automotive winter testing in Northern Sweden. This means to support the local automotive test entrepreneurs and through them their customers: the car manufacturers and their suppliers. To succeed in this task, the center relies on the university's areas of leading research and most importantly on the cooperation between those areas.
13.
Spik, Susanne, 1962-, et al.
(author)
Tánnak – här och nu : En förstudie om förutsättningar för att stärka samiska innovationsföretag
2020
Reports (other academic/artistic) abstract
I början av 2000-talet tog Susanne Spik och Karin Kuoljok, båda renägare och renskötare i Sirges sameby, initiativ till ett projekt i samarbete med Luleå tekniska universitet ”Kvinna i sameby”. I samtalen i projektet föddes en dröm om att kunna spåra och följa renar på nätet. Susanne och Karin inledde ett samarbete med forskare inom genus och teknik och informations- och kommunikationsteknologi (IKT) med mål att ta fram ett kommunikationsnätverk anpassat till fjällmiljön baserat på nätverkstekniken Delayed Tolerant Networking, DTN. För att kunna vidareutveckla ett renspårningssystem anpassat till den nya nätverksmiljön och den samiska renskötselns förutsättningar startade Susanne och Karin företaget, Tánnak AB. Företaget blev en tidig föregångare i att utveckla en produkt som kombinerade informations- och kommunikationsteknik (IKT) med traditionell ekologisk kunskap (TEK). Förenklat kan TEK sägas vara kunskap om den nära naturomgivningen och hur den hållbart kan utnyttjas. TEK har vuxit fram främst hos människor som varit beroende av naturresurser de hade i sin närhet. Kunskapen skiftar över tid och följer förändringar i både traditioner och naturförhållanden. Kunskapen förs vanligtvis vidare muntligt och i praktiskt arbete. Susanne och Karins intresse för att ta fram produkten föddes utifrån sina egna erfarenheter och behov som renskötare och kvinnor, men också med en önskan om att underlätta för den yngre generationen att kunna fortsätta bedriva renskötsel och leva ett bra liv. Behovet var formulerat utifrån deras erfarenheter och syftade till att kunna utveckla och förnya renskötseln. En del i detta var att också få ner driftskostnaderna och att minska miljöpåverkan. Deras ursprungliga företag har idag övergått till företaget Tánnak International AB som marknadsför spårningssystemet för även andra områden än renskötseln. Tánnak International AB bygger vidare på den produkt som Susanne och Karin tog fram utifrån sina kunskaper om både renskötsel och markerna. Idag är dock Susanne och Karin inte längre majoritetsägare i företaget och renspårningssystemet saknar formellt patent. Susanne Spik och Karin Kuoljok har idag inte ekonomiskt inflytande i nuvarande företaget Tánnak International AB. Denna förstudie bygger på ett samarbete med nuvarande ledning för Tánnak international AB, Bobby och Jim Carlsson och de ursprungliga innovatörerna till företaget, Karin Kuoljok och Susanne Spik och forskaren May-Britt Öhman. Förstudien är en del av forskningsprojektet Dálkke – urfolksperspektiv på klimatförändringar, inom ramen för delområdet som rör samisk innovation och klimatförändringar. Förstudien syftar till att initiera en process att undersöka förutsättningarna i svenska Sápmi för samiska innovation och att fördjupa företagets kunnande om urfolk och mänskliga rättigheter. I denna process ingår att lyfta fram de ursprungliga innovatörernas grundidéer och deras produkt som en samisk innovation. På så sätt kan Tánnak International stärka sitt varumärke genom att profilera sig som ett samiskt innovationsföretag som kombinerar ny teknik med traditionell ekologisk kunskap. Certifieringar och märkningar kan vägleda konsumenter och underlätta för företag i att profilera sin produkt. Finns det behov av att certifiera samiska innovationsföretag? För att kunna undersöka förutsättningarna för att ta fram ett certifieringssystem för samiska innovationsföretag behövs en kartläggning av vilka certifieringar och märkningar som finns och hur dessa fungerar i svenska Sápmi idag.
14.
Kurdve, Martin, et al.
(author)
Can Social Sustainability Values be Incorporated in a Product Service System for Temporary Public Building Modules?
2017
In: Procedia CIRP. - : Elsevier. - 2212-8271 .- 2212-8271. ; 64, s. 193-198
Journal article (peer-reviewed) abstract
The temporary constructions industry has cost efficiency and sustainability challenges that may require new innovative business models as well as product and processes. This paperaims to discuss how social sustainability services can be included in product service system (PSS)by investigating a case where employment is offered in distributed temporary building module manufacturing in the PSS context. The case has been evaluated against PSS literature. Recent reviews and literature on inclusion of social sustainability and PSS for buildings were used. It is concluded that the current concept fits basic definitions of PSS although it is not typical. The social value of employment is difficult to evaluate and inclusion in PSS needs further research. Design practice could be used to further develop the services in the studied concept. © 2017 The Authors.
15.
Fredenberg, Erik, PhD, 1979-, et al.
(author)
A low-absorption x-ray energy filter for small-scale applications
2009
In: Optics Express. - : The Optical Society. - 1094-4087. ; 17:14, s. 11388-11398
Journal article (peer-reviewed) abstract
We present an experimental and theoretical evaluation of an x-ray energy filter based on the chromatic properties of a prism-array lens (PAL). It is intended for small-scale applications such as medical imaging. The PAL approximates a Fresnel lens and allows for high efficiency compared to filters based on ordinary refractive lenses, however at the cost of a lower energy resolution. Geometrical optics was found to provide a good approximation for the performance of a flawless lens, but a field-propagation model was used for quantitative predictions. The model predicted a 0.29 ΔE/E energy resolution and an intensity gain of 6.5 for a silicon PAL at 23.5 keV. Measurements with an x-ray tube showed good agreement with the model in energy resolution and peak energy, but a blurred focal line contributed to a 29% gain reduction. We believe the blurring to be caused mainly by lens imperfections, in particular at the periphery of the lens.
16.
Song, Xiao, et al.
(author)
Food desires and hedonic discrimination in virtual reality varying in product–context appropriateness among older consumers
2022
In: Foods. - : MDPI. - 2304-8158. ; 11:20
Journal article (peer-reviewed) abstract
Immersive virtual reality (VR) videos can replicate complex real-life situations in a systematic, repeatable and versatile manner. New product development trajectories should consider the complexities of daily life eating situations. The creation of immersive contexts of a product with varying levels of appropriateness could be a useful tool for product developers in evaluating the extent to which context may influence food acceptance and eating behavior. This study explored virtual reality (VR) as an efficient context-enhancing technology through evaluations of protein-enriched rye breads and compared the effects of a VR-simulated congruent (VR restaurant) and incongruent (VR cinema) contexts on the acceptance in older consumers. A total of 70 participants were immersed in the two VR contexts and a neutral control context in a randomized order. The responses indicating the desire and liking for rye breads were measured, and the extent of immersion during context exposure was assessed by levels of the sense of presence and engagement. Immersive VR induced positive sensations of presence and a heightened level of engagement. The VR restaurant and neutral contexts were perceived as more appropriate for consuming rye breads and induced higher desire and liking for rye breads, which supported the notion of the alignment of congruent contexts with food desire and liking. The study provides new perspectives, practical methodologies, and discoveries in regard to the creation and application of VR-immersed contexts in food product evaluation. Moreover, it focused on a consumer segment (older consumers) that has seldom been investigated in previous relevant studies. The findings suggest that immersive VR technology, as a tool for evaluating contextual factors, is important for new product development. The good user experience among older consumers further indicated the potential value of VR as a context-enhancing tool for product development.
17.
18.
19.
Larsson, Stefan, et al.
(author)
Smart City Governance - AI Ethics in a Spatial Context : Select papers from 2021/2022
2022
Reports (pop. science, debate, etc.) abstract
This brief anthology presents the basics of the interdisciplinary course called “Smart City Governance – AI Ethics in a Spatial Context”, given at Lund University. Furthermore, it includes three papers and a task written by students from the class of 2021/2022 in order to show examples of the topics possible to analyse when combining engineering students from programmes on data, ICT and land surveying with students from the humanities or social sciences.Head of course is Stefan Larsson, Associate Professor at the Department of Technology and Society at LTH, Lund University. As a socio-legal scholar and lawyer at a faculty of engineering, he leads a group studying governance and issues of trust and transparency with autonomous and AI-driven technologies in domains ranging from the public sector to consumer markets, medicine and social robotics.Laetitia Tanqueray is a Teaching Assistant on this course, and canvas coordinator. Laetitia holds bachelors’ in English Law and French Law and a master’s in Sociology of Law. She is a project assistant at the Department of Technology and Society at LTH, Lund University, investigating questions related to socio-legal robotics.
20.
Liwång, Hans, et al.
(author)
Ship security challenges in high-risk areas : manageable or insurmountable?
2015
In: WMU Journal of Maritime Affairs (JoMA). - : Springer Berlin/Heidelberg. - 1651-436X .- 1654-1642. ; 14:2, s. 201-217
Journal article (peer-reviewed) abstract
Piracy can lead to risks so high that they, according to the International Maritime Organization, are tolerable only if risk reduction is not practicable or is disproportionate to the benefits achieved. Therefore, there is a need for reducing ship security risks in relation to antagonistic threats such as piracy. The aim of this study is to identify challenges for ship operators when developing their ship security management. Furthermore, this study also investigates two central aspects in the analysis: understanding the threat and understanding how a security threat affects the crew and operation of the ship. It is clear from the analysis that the importance of subjective aspects beyond a ship operators’ direct control is high. This seems to be the fact for all aspects of the risk management process. The situation is also dynamic as the security risk, as well as the risk perception, can change dramatically even though there are no actual operational changes. As a result, the ship security management process is highly iterative and depends on situations on board as well as conditions out of the ship operator’s control. In order to make ship security manageable, the risk management has to put particular focus on methodological understanding, relevant system understanding and well-defined risk acceptance criteria as well as on including all levels of the organization in the risk reduction implementation and on a continuous monitoring.
21.
Jeong, Seung Hee, 1978-
(author)
Soft Intelligence : Liquids Matter in Compliant Microsystems
2016
Doctoral thesis (other academic/artistic) abstract
Soft matter, here, liquids and polymers, have adaptability to a surrounding geometry. They intrinsically have advantageous characteristics from a mechanical perspective, such as flowing and wetting on surrounding surfaces, giving compliant, conformal and deformable behavior. From the behavior of soft matter for heterogeneous surfaces, compliant structures can be engineered as embedded liquid microstructures or patterned liquid microsystems for emerging compliant microsystems.Recently, skin electronics and soft robotics have been initiated as potential applications that can provide soft interfaces and interactions for a human-machine interface. To meet the design parameters, developing soft material engineering aimed at tuning material properties and smart processing techniques proper to them are to be highly encouraged. As promising candidates, Ga-based liquid alloys and silicone-based elastomers have been widely applied to proof-of-concept compliant structures.In this thesis, the liquid alloy was employed as a soft and stretchable electrical and thermal conductor (resistor), interconnect and filler in an elastomer structure. Printing-based liquid alloy patterning techniques have been developed with a batch-type, parallel processing scheme. As a simple solution, tape transfer masking was combined with a liquid alloy spraying technique, which provides robust processability. Silicone elastomers could be tunable for multi-functional building blocks by liquid or liquid-like soft solid inclusions. The liquid alloy and a polymer additive were introduced to the silicone elastomer by a simple mixing process. Heterogeneous material microstructures in elastomer networks successfully changed mechanical, thermal and surface properties.To realize a compliant microsystem, these ideas have in practice been useful in designing and fabricating soft and stretchable systems. Many different designs of the microsystems have been fabricated with the developed techniques and materials, and successfully evaluated under dynamic conditions. The compliant microsystems work as basic components to build up a whole system with soft materials and a processing technology for our emerging society.
22.
Lindborg, PerMagnus, 1968-
(author)
A taxonomy of sound sources in restaurants
In: Applied Acoustics. - 0003-682X .- 1872-910X.
Journal article (peer-reviewed) abstract
Restaurants are complex environments where all our senses are engaged. Physical and psychoacoustic factors have been shown to be associated with perceived environmental quality in restaurants. More or less designable sound sources such as background music, voices, and kitchen noises are believed to be important in relation to the overall perception of the soundscape. Previous research publications have suggested typologies and other structured descriptions of sound sources for some environmental contexts, such as urban parks and offices, but there is no detailed account that is relevant to restaurants. While existing classification schemes might be extendable, an empirical approach was taken in the present work. We collected on-site data in 40 restaurants (n = 393), including perceptual ratings, free-form annotations of characteristic sounds and whether they were liked or not, and free-form descriptive words for the environment as a whole. The annotations were subjected to analysis using a cladistic approach and yielded a multi-level taxonomy of perceived sound sources in restaurants. Ten different classification taxa were evaluated by comparing the respondents' Liking of sound sources, by categories defined in the taxonomy, and their Pleasantness rating of the environment as a whole. Correlation analysis revealed that a four-level clade was efficient and outperformed alternatives. Internal validation of the Pleasantness construct was made through separate ratings (n = 7) of on-site free-form descriptions of the environment. External validation was made with ratings from a separate listening experiment (n = 48). The two validations demonstrated that the four-level Sound Sources in Restaurants (SSR) clade had good construct validity and external robustness. Analysis of the data revealed two findings. Voice-related characteristic sounds including a ‘people’ specifier were more liked than those without such a specifier (d = 0.14 SD), possibly due to an emotional crossmodal association mechanism. Liking of characteristic sounds differed between the first and last annotations that the respondents had made (d = 0.21 SD), which might be due to an initially positive bias being countered by exposure to a task inducing a mode of critical listening. We believe that the SSR taxonomy will be useful for field research and simulation design. The empirical findings might inform theory, specifically research charting the perception of sound sources in multimodal environments.
23.
Ström, Henrik, 1981, et al.
(author)
Behaviour and stability of the two-fluid model for fine-scale simulations of bubbly flow in nuclear reactors
2015
In: International Journal of Chemical Reactor Engineering. - : Walter de Gruyter GmbH. - 1542-6580 .- 2194-5748. ; 13:4, s. 449-459
Journal article (peer-reviewed) abstract
In the present work, we formulate a simplistic two-fluid model for bubbly steam-water flow existing between fuel pins in nuclear fuel assemblies. Numerical simulations are performed in periodic 2D domains of varying sizes. The appearance of a non-uniform volume fraction field in the form of meso-scales is investigated and shown to be varying with the bubble loading and the domain size, as well as with the numerical algorithm employed. These findings highlight the difficulties involved in interpreting the occurrence of instabilities in two-fluid simulations of gas-liquid flows, where physical and unphysical instabilities are prone to be confounded. The results obtained in this work therefore contribute to a rigorous foundation in on-going efforts to derive a consistent meso-scale formulation of the traditional two-fluid model for multiphase flows in nuclear reactors.
24.
Isacson, Åsa, 1983, et al.
(author)
The use of digital layers in post-growth communities - an exploratory study
2023
In: Proceedings for the 6th International Conference on Smart Villages and Rural Development (COSVARD 2023). - 9780734057150
Conference paper (other academic/artistic) abstract
The pursuit of infinite growth on a planet with finite resources is leading to a failure in achieving global sustainable transition goals. The concept of Degrowth or 'post-growth' has emerged as a counter-movement advocating for alternative approaches focused on living within resource constraints. Within this context, small-scale communities with post-growth orientations are particularly interesting, as they actively explore their own alternative development models. These communities have potential to act as decentralised laboratories for radical change, translating Degrowth/post-growth theory into actionable practices. This paper examines how the operational tools have changed for post-growth communities since 2004 (Web 2.0). Through in-depth interviews with tech-savvy representatives in this field, the study explores the potential of "new" technologies to empower post-growth communities.
25.
Kersten, Anton, 1991, et al.
(author)
Inverter and Battery Drive Cycle Efficiency Comparisons of CHB and MMSP Traction Inverters for Electric Vehicles
2019
In: 2019 21st European Conference on Power Electronics and Applications, EPE 2019 ECCE Europe. ; , s. 1-12
Conference paper (peer-reviewed) abstract
This paper investigates the performance of several inverter types for electric vehicles. A standard two-level and two seven-level multilevel inverters, a cascaded H-bridge (CHB) and a modular multilevel series parallel (MMSP) inverter, are considered. Based on the AC impedance spectra measured on a single battery cell, the battery pack impedances of the multilevel and two-level inverter systems are modeled. The inverter losses are modeled using the semiconductors’ datasheets. Based on the loss models, the inverter and battery efficiency during different driving cycles are assessed. In comparison to the two-level inverter system, the multilevel inverter drivetrains show an increased drivetrain efficiency, despite increased battery losses. The MMSP topology showed the best result. In comparison to the CHB topology, the battery losses were reduced by the MMSP inverter system.
