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Phase Error Calculation for Fast Time-Domain Bistatic SAR Algorithms
No full textIn synthetic aperture radar (SAR) processing, there is a trade-off between
accuracy and speed. The approximations in an algorithm help to increase the
algorithm’s speed but cause deterministic phase errors which directly affect
the SAR image quality. This paper discusses the phase error calculations for
bistatic fast backprojection (BiFBP) and bistatic fast factorized
backprojection (BiFFBP) which are essential for setting their parameters. The
phase error calculation principle for bistatic SAR in comparison to monostatic
SAR is presented. This principle is used to derive the maximum phase error
equation
Om glappen vi skapar och de märken som blir – materiell-diskursiva praktiker i kommunkontext
No full textUtgångspunkten för min forskning är ett upplevt glapp i IT- och
e-förvaltningsutveckling. Policys och strategier har långtgående visioner om
hur IT kan och kommer att förändra allt ifrån vårt vardagliga arbete och
privatliv till att förändra samhällsstrukturer och maktordningar. För att möta
detta görs stora investeringar varje år inom kommunal IT. Ändå är upplevelsen
att ”det händer inget”.
Syftet med forskningen är att presentera förståelser för abstrakta och komplexa
ting som e-förvaltning, innovation (förändringsarbete), design och
infrastruktur. Forskningen presenterar olika perspektiv för dessa ting och
utmanar normerade förståelser för dem. Ett exempel på detta är hur
infrastruktur med en normativ förståelse som abstrakt och passiv också visar
sig vara påtagligt konkret och performativt. Målsättningen är sedan att dessa
förståelser skall ligga till grund för att praktisera en IT- och
e-förvaltningsutveckling, som inte känns ”glappande” eller stagnerad.
Den forskning, som presenteras och prövas i denna avhandling, är situerad i en
kommunkontext och bygger på deltagande aktionsforskning. Deltagande
aktionsforskning innebär, att jag har försökt att reflexivt praktisera
forskning i syfte att skapa kunskap och förändring tillsammans med andra och
direkt i de samanhang jag har verkat. Aktionsforskningen innebär, att jag inte
forskar om utan med olika kommunala praktiker. Denna typ av forskning är inte
knuten till en specifik metod utan behöver anpassas och utvecklas i sitt
sammanhang. I detta ingår en återkommande utmaning av befintlig
verksamhetspraktik och förgivettaganden, inte minst mina egna.
Licentiatavhandlingen, som är ”ett steg på vägen”, handlar mer om förståelser
än om förklaringar. Avhandlingen är skriven som en form av
sammanläggningsavhandling, som bygger på fyra artiklar och en delvis fristående
kappa. Mitt skrivande och därmed den text, som utgör avhandlingen är
”essäistisk”. Essäformen har gjort det möjligt för mig att använda
avhandlingsskrivandet som en fortsatt prövning av de olika perspektiv, som
artiklarna presenterar
Maintainability Predictors For Relational Database-Driven Software Applications: Extended Results From A Survey
No full textSoftware maintainability is a very important quality attribute. Its prediction
for relational database-driven software applications can help organizations
improve the maintainability of these applications. The research presented
herein adopts a survey-based approach where a survey was conducted with 40
software professionals aimed at identifying and ranking the important
maintainability predictors for relational database-driven software
applications. The survey results were analyzed using frequency analysis. The
results suggest that maintainability prediction for relational database-driven
applications is not the same as that of traditional software applications in
terms of the importance of the predictors used for this purpose. The results
also provide a baseline for creating maintainability prediction models for
relational database-driven software applications
Estimates of marginal cost savings for Intelligent Truck Parking Services in a combined deployment scenario
No full textIntelligent Truck Parking (ITP) involves efficient management of information as
a tool for addressing some of the problems related to truck parking, such as,
the inability to navigate to, or reserve a parking space. Different telematic
services (ITP core services) may be required to address different stakeholder
needs, e.g., a navigation service for finding the way to a truck parking area,
and a reservation service for assuring the availability of a parking space when
in the parking area. In addition to ITP core services, there are several other
telematic services that address transport problems in general. If the synergies
of different services are taken into account during design and deployment of
telematic services, cost reduction may be achieved through functionality
sharing. In this article, we have identified services that are relevant for
sharing functionalities with ITP core services, estimate functionality costs
and perform a synergy analysis to assess the marginal cost savings as a result.
Overall results indicates that Traffic Information Broadcasting (TIB),
Estimated Time of Arrival (ETA) for goods, and Geo-fencing (GEO) can form
clusters with ITP core services that could lead to better cost savings compared
to the rest of the services studied
Systematic leadership towards sustainability
No full textSystematic leadership towards sustainability implies utilization of systems
thinking for step-wise approaches to transformative changes towards sustainable
societies. This ‘call-for-papers’ (CfPs) for a Special Volume of the Journal of
Cleaner Production is focused upon what types of research are needed for us to
make the necessary local, regional, national and global changes. This CfPs is
for anyone who wishes to address these challenges seriously, that is, to
utilize essential aspects of leadership to contribute strategically to the
transition towards sustainable societies. To successfully address these
challenges, people from different sectors and disciplines must work together in
a coordinated and efficient way. We wish to explore the question: What support
do such transformative endeavors require and how can science contribute
On Mobility Generated Signaling in Cognitive Radio Network Clusters
No full textThe rapid migration towards wireless connectivity means
that the radio spectrum must be efficiently utilized to conserve capacity and
to avoid overcrowding, particularly in densely populated areas. Towards this
goal, cognitive radio technology is a key concept. The basic idea is to allow
unlicensed users access to licensed spectrum, under the condition that the
interference perceived by the licensed users is minimal. A novel architecture
designed and developed at the application layer has been suggested by
researchers at Blekinge Institute of Technology for the management of cognitive
radio networks. Emphasizing on signaling facilities in this architecture and
common control channel dimensioning aspects, the paper reports on simulation
results regarding node mobility for a particular network model.
To reduce the energy consumption of mobile devices, innovative signaling
strategies are a very important topic to consider in novel mobile system
architectures
Towards a scalable cloud platform for search-based probabilistic testing
No full textProbabilistic testing techniques that sample input data at random from a
probability distribution can be more effective at detecting faults than
deterministic techniques. However, if overly large (and therefore expensive)
test sets are to be avoided, the probability distribution from which the input
data is sampled must be optimised to the particular software-under-test. Such
an optimisation process is often resource-intensive. In this paper, we present
a prototypical cloud platform-and architecture-that permits the optimisation of
such probability distributions in a scalable, distributed and robust manner,
and thereby enables cost-effective probabilistic testing
Back to Normal? Impact of Temporally Increasing Network Disturbances on QoE
No full textBrief episodes of network faults and performance issues adversely affect the
user Quality of Experience (QoE). Besides damaging the current opinions of
users, these events may also shape user’s future perception of the service.
Therefore, it is important to quantify the impact of such events on QoE over
time. In this paper, we present our findings on the temporal aspects of user
feedback to disturbances on networks. These findings are based on subjective
user tests performed in the context of web browsing on an e-commerce website.
The results of this study suggest that the QoE drops significantly every time
the page load time grows. The after-effects of network disturbances on user QoE
remain visible even when the network problems are over, i.e., users do not
immediately return to the same level of opinion scores as compared to the
corresponding pre-disturbance phase. They tend to remember their recent
experiences. Our results also show that there are four segments of users that
exist with regards to their feedback to page load times. Network operators may
customize their services according to each segment of users to raise the
overall QoE. Finally, we show that the exponential relationship provides best
fits of QoE and page load times for all segments of users
How can fossil fuel based public bus transport systems become a sustainable solution for Swedish medium-sized cities?
No full textVehicles, infrastructure, fuel systems and other energy-driven systems that
serve public transport are complex with many resource inputs and outputs, and
involve many processes. Life Cycle Assessment (LCA) and Life Cycle Costing
(LCC) helps analyzing those by quantifying environmental and economic effects,
but will not in themselves provide a full systems perspective.
Swedish authorities have set ambitious national goals, and many regions targets
a 100% increase in public transport by 2020. The medium sized city of
Karlskrona (36,000 inhabitants), that is included in this study together with
Sundsvall and Jönköping, embraces those goals too.
This study analyzes relevant differences between bus solutions, to investigate
a change to more sustainable bus propulsion systems. The study zooms down to
compare energy carriers (diesel, biodiesel, biogas, and electricity) in
different powertrain combinations (combustion engines, electric hybrids, and
pure electric).
The Framework for Strategic Sustainable Development (FSSD) where principles are
defining a sustainable future is used to broaden from a cost and
environmentally shortsighted perspective to a long-term sustainability
perspective with systems thinking. The Strategic Life Cycle Assessment (SLCA)
is first used to give a quick full scope of sustainability challenges in each
bus life cycle stage from extraction to end of life. Then LCA and LCC
approaches are used to” dig deeper” into prioritized identified challenges.
Initial study results suggest that electric drivetrains would be preferable in
city buses within the coming decade - both from an economic and a
sustainability perspective. It not only lowers emissions and energy usage, but
also provides a platform for future promising energy carriers
A Little Rebellion Now and Then Is a Good Thing: Views on the Requirements Engineering Conference
No full text— A little rebellion now and then is a good thing.
This short position statement describes my views on some of
the challenges associated with many conferences, the
Requirements Engineering Conference being among them. The
main concepts are; the goals, as well as criteria for paper
selection for the conference should be defined explicitly, and
shared with the community. Industry involvement in the
conference should be increased, but the focus of all tracks should
be quality – what constitutes quality however needs to be defined
and agreed on. Industrial validation of research results have to be
more than an intention. Last but not least, how papers are
presented and discussed needs to change, focusing on quality over
quantity