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Do System Test Cases Grow Old?
No full textCompanies increasingly use either manual or automated system testing to ensure
the quality of their software products. As a system evolves and is extended
with new features the test suite also typically grows as new test cases are
added. To ensure software quality throughout this process the test suite is
continously executed, often on a daily basis. It seems likely that newly added
tests would be more likely to fail than older tests but this has not been
investigated in any detail on large-scale, industrial software systems. Also it
is not clear which methods should be used to conduct such an analysis. This
paper proposes three main concepts that can be used to investigate aging
effects in the use and failure behavior of system test cases: test case
activation curves, test case hazard curves, and test case half-life. To
evaluate these concepts and the type of analysis they enable we apply them on
an industrial software system containing more than one million lines of code.
The data sets comes from a total of 1,620 system test cases executed a total of
more than half a million times over a time period of two and a half years. For
the investigated system we find that system test cases stay active as they age
but really do grow old; they go through an infant mortality phase with higher
failure rates which then decline over time. The test case half-life is between
5 to 12 months for the two studied data sets
An Experimental, Numerical and SEM Study of Fracture in a Thin Polymer Film
No full textObservations and analysis of samples from scanning electron microscopic (SEM)
micrographs has been concerned in this work. The samples originate from
fractured mechanical mode I tensile testing of a thin polymer film made of
polypropylene used in the packaging industry. Three different shapes of the
crack; elliptical, circular and flat, were used to investigate the decrease in
load carrying capacity. The fracture surfaces looked similar in all studied
cases. Brittle-like material fracture process was observed both by SEM
micrographs and the experimental mechanical results. A finite element model was
created in Abaqus as a complementary tool to increase the understanding of the
mechanical behaviour of the material. The numerical material models were
calibrated and the results from the simulations were comparable to the
experimental results
A Health-IoT Platform Based on the Integration of Intelligent Packaging, Unobtrusive Bio-Sensor and Intelligent Medicine Box
No full textIn-home healthcare services based on the Internet-of-Things (IoT) have great
business potential; however, a comprehensive platform is still missing. In this
paper, an
intelligent home-based platform, the iHome Health-IoT, is
proposed and implemented. In particular, the platform involves 1) an
open-platform-based intelligent medicine box (iMedBox) with enhanced
connectivity and interchangeability for the integration of devices and
services, 2) intelligent pharmaceutical packaging (iMedPack) with communication
capability enabled by passive radio-frequency identification (RFID) and
actuation capability enabled by functional materials, and 3) flexible and
wearable bio-medical sensor device (Bio-Patch) enabled by the state-of-the-art
inkjet printing technology and system-on-chip. The proposed platform seamlessly
fuses IoT devices (e.g., wearable
sensors, intelligent medicine packages, etc.) with in-home
healthcare services (e.g., telemedicine) for an improved user
experience and service efficiency. The feasibility of the
implemented iHome Health-IoT platform has been proven in field trials
Physical Layer Secrecy Performance over Rayleigh/Rician Fading Channels
No full textIn this paper, we investigate the physical layer secrecy performance of a
single-input single-output system that consists of single antenna devices and
operates in the presence of a single antenna passive eavesdropper over
dissimilar fading channels. In particular, we consider two scenarios in terms
of dissimilar fading channel arrangements: 1) The legal/illegal channels are
subject to Rayleigh/Rician fading, respectively; 2) The legal/illegal channels
are subject to Rician/Rayleigh fading, respectively. Specifically, analytical
expressions for the probability of the existence of a non-zero secrecy capacity
and the secrecy outage probability are derived by using statistical
characteristics of the signal-to-noise ratio. Numerical results are provided
for selected scenarios to illustrate applications of the developed analytical
expressions
Networking in a Large-Scale Distributed Agile Project
No full textContext: In large-scale distributed software projects the expertise may be
scattered across multiple locations.
Goal: We describe and discuss a large-scale distributed agile project at
Ericsson, a multinational telecommunications company headquartered in Sweden.
The project is distributed across four development locations (one in Sweden,
one in Korea and two in China) and employs 17 teams. In such a large scale
environment
the challenge is to have as few dependences between teams as possible, which is
one reason why Ericsson introduced crossfunctional feature teams – teams that
are capable of taking the full responsibility for implementing one entire
feature. To support such teams when solving problems, ensure knowledge sharing
within the project and safeguard the quality Ericsson introduced a new role –
Technical Area Responsible (TAR).
Method: We conducted extensive fieldwork for 9 months at two Ericsson sites in
Sweden and China. We interviewed
representatives from different roles in the organization, in addition to focus
groups and a survey with seven teams.
Results: We describe the TAR role, and how the TARs
communicate, coordinate and support the teams. Also architects support the
teams, however not as closely as the TARs. We found that the TAR is usually a
senior developer working halftime or fulltime in the role. We also present
measures of the actual knowledge network of three Chinese and three Swedish
teams and the TARs position in it.
Conclusions: TARs are central in the knowledge network and act as the boundary
spanners between the teams and between the sites. We learned that availability
of the TARs across sites is lower than that with local TARs. We also found that
the size of a team’s knowledge network depends on how long the team members
have been working in the company. Finally we discuss the advantages and the
challenges of introducing experts in key roles in large scale distributed agile
development
Association between Sleep Disturbances and Leisure Activities in the Elderly: A Comparison between Men and Women.
No full textIt has been suggested that physical or social activity is associated with fewer
sleep disturbances among elderly people. Women report more sleep disturbances
than men, which could indicate a variation in activity patterns between the
genders. The aim of this study was to investigate associations between sleep
disturbances and leisure activities in men and women (n = 945) aged ≥60 years
in a Swedish population. Sleep disturbances were measured using eight
dichotomous questions and seventeen variables, covering a wide range of leisure
activities. Few leisure activities were found to be associated with sleep
disturbances and their importance decreased when the models were adjusted for
confounders and gender interactions. After clustering the leisure activities
and investigating individual activities, socio-intellectual activities were
shown to be significant for sleep. However, following adjustment for
confounders and gender interactions, home maintenance was the only activity
significant for sleep. Being a female increased the effect of home maintenance.
Besides those leisure activities, poor/fair self-rated health (OR 7.50, CI:
4.27-11.81) and being female (OR 4.86, CI: 2.75-8.61) were found to have the
highest association with poor sleep. Leisure activities pursued by elderly
people should focus on activities of a socio-intellectual nature, especially
among women, to promote sleep
Suppression of Clutter in Multichannel SAR GMTI
No full textIn this paper, results of moving target detection in multichannel UHF-band
Synthetic Aperture Radar (SAR) data are shown. The clutter suppression is done
using Finite Impulse Response (FIR) filtering of multichannel SAR in
combination with a 2-stage Fast Backprojection (FBP) algorithm to focus the
moving target using relative speed. The FIR filter coefficients are chosen with
the use of STAP filtering. Two parameters are used for target focusing, target
speed in range and in azimuth. When the target is focused, both speed
parameters of the target are found. In the experimental results, two channels
were used in order to suppress clutter. In the resulting SAR images it is
obvious that very strong scatterers and the forest areas have been suppressed
in comparison to the moving target in the image scene. The gain obtained can be
measured using SCNR gain, which is about 19dB. Another way to measure signal
processing gain is the ability to suppress the strongest reflecting object in
the SAR scene. The gain of target in relation to this object is 25dB. This
shows that using UHF-band SAR GMTI for suppressing forest and increasing the
target signal can work
(Re)acting the city. Physical planning practices and challenges in urban development projects of the Entrepreneurial City
No full textThe aim of this dissertation is to traceand discuss the practices and
challenges of physical planning within an Entrepreneurial City approach to
urban policy. The research aim is addressed by focusing on three questions: 1)
how have the practices of physicalplanning been influenced by the context of an
Entrepreneurial City approach to urban policy 2) how has physical planning
responded to this urban policy context, and 3) which potential dilemmas for
physical planning practice derive from this new context?
By an Entrepreneurial City approach tourban policy I understand an approach
whereby there is an attention placed over strategies to promote local economic
growth and attract investments, companies and specific types of people in to
the city. Arguably urban policies focus less on welfare-related and
redistribution strategies. There is an adoption of private sector discourses
and tools to promote the city as a place to live, work and invest in. These
discourses and tools pass through place-making strategies, marketing,
engagement in speculative, risk-taking market-led projects, and seeking
partners with whom to establish alliances that will serve to promote the city.
The strong emphasis of Entrepreneurial City approaches on interventions over
the built environment of a city or neighborhood implies a greater attention to
what is happening to the practices of physical planning in municipalities that
have adopted this approach. Existing studies tend to emphasize that it
signifies a decrease in the scope of influence for public sector, and by
extention for physical planning, in the governance and steering of these
projects.
The dissertation focuses on large-scale urban development projects – Brunnshög,
in Lund, and Bo01, Norra Sorgenfri and Hyllie, in Malmö. The projects were
chosen due to their likelihood toillustrate physical planning practices marked
by an Entrepreneurial City approach.
The main findings of this thesis refute the idea of a turn in urban policy
towards entrepreneurial city approaches, and illustrate instead a process by
which new practices and values coincide with previously established settings
and practices. Physical planning is adopting the discourses of an urban policy
approach where intercity competition for new industries (preferably in
knowledge-intensive sectors) and residents(preferably the “creative classes”)
guide urban development projects. The governance setting is marked by the need
to establish working networks and partnerships that will create the capacity to
act. Experimentation, piece-meal approaches and inter-project learning mark the
adaptation strategies to an urban policy context that is still changing.
Potential dilemmas lie in the fragmented character of the partnerships required
to execute the projects, and in the assumption that these projects will result
in the rehabilitation of the socio-economic trends of the city and promote
local economic growth. Additionally the resulting built environments are prone
to processes of gentrification and displacement, and spatial and socioeconomic
polarization
Local Linear Time Convergence of a Primal-Dual Energy Minimization Algorithm for Parallel Processing
No full textWe consider energy minimization by speed-scaling
of an open shop multiprocessor with n jobs and m machines. The paper studies
the complexity of a primal-dual solution algorithm of [4], which was an open
question in that paper.We prove that in a neighbourhood of the solution the
complexity of the algorithm is O(mn log(1/ε) if n and m are not equal and ε is
the roundoff error of the computer.
The paper demonstrates how linearization can be used to investigate the
complexity of an algorithm close to the optimum. An estimate of the size of the
neighbourhood where the linearization error is smaller than the computer’s
roundoff error is also given
Institutional barriers and good practice solutions
No full textOpen access to research data provides many benefits to science and society, but
as the open access trend grows it becomes increasingly clear that providing
unrestricted access to research data is not inherently a “good thing”, and it
is certainly not easy to achieve. The RECODE project looks at the grand
challenges associated with open access and data preservation and dissemination,
including technological and infrastructural, legal and ethical, and
institutional and policy issues. In particular, it seeks to understand and use
the fragmentation between and within disciplines in order to address these
challenges. The aim is to produce policy recommendations for open access to
research data, based on existing good practice.
In this fourth RECODE deliverable we focus on the challenges faced by
institutions, such as archives, libraries, universities, data centres and
funding bodies, in making open access to research data possible. Policy makers
and the scientific community expect these institutions to play an important
role in creating and funding data sharing infrastructures and stimulating and
assisting researchers to make their research material public. They look towards
these institutions to curate and preserve information, and provide guidance to
researchers in managing their data