Blekinge Institute of Technology
Electronic Research Archive - Blekinge Tekniska HögskolaNot a member yet
1855 research outputs found
Sort by
Heterogeneous Systems Testing Techniques: An Exploratory Survey
No full textHeterogeneous systems comprising sets of inherent subsystems are challenging to
integrate. In particular, testing for interoperability and conformance is a
challenge. Furthermore, the complexities of such systems amplify traditional
testing challenges. We explore (1) which techniques are frequently discussed in
literature in context of heterogeneous system testing that practitioners use to
test their heterogeneous systems; (2) the perception of the practitioners on
the usefulness of the techniques with respect to a defined set of outcome
variables. For that, we conducted an exploratory survey. A total of 27 complete
survey answers have been received. Search-based testing has been used by 14 out
of 27 respondents, indicating the practical relevance of the approach for
testing heterogeneous systems, which itself is relatively new and has only
recently been studied extensively. The most frequently used technique is
exploratory manual testing, followed by combinatorial testing. With respect to
the perceived performance of the testing techniques, the practitioners were
undecided regarding many of the studied variables. Manual exploratory testing
received very positive ratings across outcome variables
Innovation determinants over industry life cycle
No full textThis paper analyzes how the influence of firm-level innovation determinants
varies over the industry life cycle. Two sets of determinants are
distinguished: (1) determinants of a firm's innovation propensity, i.e. the
likelihood of being innovative and (2) determinants of its innovation
intensity, i.e. innovation sales. By combining the literature emphasizing
firms' internal resources (micro-level) with the research strand on the role of
the industry context (meso-level), the paper develops hypotheses about the
relative importance of firm-level innovation determinants over the industry
life cycle. Estimation of a firm-level model of innovation in Sweden, while
acknowledging the stage of the life cycle of the industry a firm belongs to,
shows that the importance of the determinants of innovation propensity and
intensity is not equal over the stages of an industry's life cycle
The Contextual Nature of Innovation - An Empirical Investigation of Three Software Intensive Products
No full textContext:
New products create significant opportunities for differentiation and
competitive advantage. To increase the chances of new product success, a
universal set of critical activities and determinants have been recommended.
Some researchers believe, however, that these factors are not universal, but
are contextual.
Objective:
This paper reports innovation processes followed to develop three software
intensive products for understanding how and why innovation practice is
dependent on innovation context.
Method:
This paper reports innovation processes and practices with an in-depth
multi-case study of three software product innovations from Ericsson, IBM, and
Rorotika. It describes the actual innovation processes followed in the three
cases and discusses the observed innovation practice and relates it to
state-of-the-art.
Results:
The cases point to a set of contextual factors that influence the choice of
innovation activities and determinants for developing successful product
innovations. The cases provide evidence that innovation practice cannot be
standardized, but is contextual in nature.
Conclusion:
The rich description of the interaction between context and innovation practice
enables future investigations into contextual elements that influence
innovation practice, and calls for the creation of frameworks enabling activity
and determinant selection for a given context – since one size does not fit
all
Quality of Experience on Smartphones : Network, Application, and Energy Perspectives
No full textSmartphones have become crucial enablers for users to exploit online services
such as learning, leisure, communicating, and socializing. The user-perceived
quality of applications and services is an important factor to consider, in
order to achieve lean resource management, to prevent user churn and revenue
depletion of service or network providers. This is often studied within the
scope of Quality of Experience (QoE), which has attracted researchers both in
academia and industry.
The objective of this thesis is to study the most important factors influencing
QoE on smartphones and synthesize solutions for intervention. The temporal
impairments during a real-time energy-hungry video streaming are studied. The
aim is to quantify the influence of temporal impairments on the user-perceived
video QoE at the network and application level together with energy
measurements, and also to propose solutions to reduce smartphone energy
consumption without degrading the user’s QoE on the smartphone for both
user-interactive, e.g., video, and non-interactive cases.
QoE measurements on smartphones are performed throughout in-the-wild user
studies. A set of quantitative Quality of Experience (QoE) assessment tools are
implemented and deployed for automatic data logging at the network- and
application-level. Online momentary survey, Experience Sampling Method (ESM)
software, and Day Reconstruction Method (DRM) along weekly face-to-face user
interviews are employed. The subjective QoE is obtained through qualitative
feedback including Mean Opinion Score (MOS) as well as in-situ indications of
poor experiences by users. Additionally, energy measurements on smartphones are
conducted in controlled-lab environment with the Monsoon device.
The QoE of smartphone applications and services perceived by users depends on
many factors including anomalies in the network, application, and also the
energy consumption.
At the network-level, high packet delay variation causes long video freezes
that eventually impact negatively the end-user perceived quality. The freezes
can be quantified as large time gaps in-between the displayed pictures during a
video stream at the application-level. We show that the inter-picture time in
cellular-based video stream can be represented via two-state exponential ON/OFF
models. We show models representing the non-linear relationship between the QoE
and the mean inter-picture time. It is shown that energy measurements help to
reveal the temporal impairments in video stream enabling energy consumption as
a QoE indicator. Next, energy waste and saving during temporal impairments are
identified. Additionally, other video streaming use cases, e.g., “download
first and watch later”, are studied and appropriate energy-saving download
scheduling mechanisms are recommended. The possibility for decreasing energy
consumption when the smartphone screen is OFF, while maintaining QoE, is
revealed. We first show exponential models to represent user’s interaction with
smartphone, then propose a NyxEnergySaver software, to control the cellular
network interface in a personalized manner to save smartphone energy. According
to our findings, more than 30% smartphone energy can be saved without impacting
the user-perceived QoE
Registered nurses’ descriptions of caring: a phenomenographic interview study
No full textBackground: Nursing has come a long way since the days of Florence Nightingale
and even though no consensus
exists it would seem reasonable to assume that caring still remains the inner
core, the essence of nursing. In the
light of the societal, contextual and political changes that have taken place
during the 21st century, it is important
to explore whether these might have influenced the essence of nursing. The aim
of this study was to describe
registered nurses’ conceptions of caring.
Methods: A qualitative design with a phenomenographic approach was used. The
interviews with twenty-one
nurses took place between March and May 2013 and the transcripts were analysed
inspired by Marton and Booth’s
description of phenomenography.
Results: The analysis mirrored four qualitatively different ways of
understanding caring from the nurses’ perspective:
caring as person-centredness, caring as safeguarding the patient’s best
interests, caring as nursing interventions and
caring as contextually intertwined.
Conclusion: The most comprehensive feature of the nurses’ collective
understanding of caring was their recognition and acknowledgment of the person
behind the patient, i.e. person-centredness. However, caring was described as
being part of an intricate interplay in the care context, which has impacted on
all the described conceptions of caring.
Greater emphasis on the care context, i.e. the environment in which caring
takes place, are warranted as this could
mitigate the possibility that essential care is left unaddressed, thus
contributing to better quality of care and safer patient care
Cognitive amplify-and-forward relay networks with beamforming under primary user power constraint over Nakagami-m fading channels
No full textIn this paper, we analyze the performance of cognitive amplify-and-forward (AF)
relay networks with beamforming under
the peak interference power constraint of the primary user (PU). We focus on
the scenario that beamforming is applied at the multi-antenna secondary
transmitter and receiver. Also, the secondary relay network operates in channel
state information assisted AF mode, and the signals undergo independent
Nakagami-m fading. In particular, closed-form expressions for the outage
probability and symbol error rate (SER) of the considered network over
Nakagami-m fading are presented. More importantly, asymptotic closed-form
expressions for the outage probability and SER are derived. These tractable
closed-form expressions for the network performance readily enable us to
evaluate and examine the impact of network parameters on the system
performance. Specifically, the impact of the number of antennas, the fading
severity parameters, the channel mean powers, and the peak interference power
is addressed. The asymptotic analysis manifests that the peak interference
power constraint imposed on the secondary relay network has no effect on the
diversity gain. However, the coding gain is affected by the fading parameters
of the links from the primary receiver to the secondary relay network
The Choquet Integral Applied to Ranking Therapies in Radiation Cystitis
No full textRadiation cystitis is in general rarely occurring, which makes it very
difficult to study in a large group of clinical trials. Most available data
about radiation cystitis treatment come from a small number of descriptive
studies or from expert opinions. As clinical data are considered to have low
quality then physicians, who are still facing patients with a disease hugely
influencing quality of life, mostly base on their own experience. We thus want
to test fuzzy decision-making model, regarded as a valuable tool, to help in
selecting a patient-tailored treatment in radiation cystitis.
Theoretical fuzzy decision-making models, possessing the utility matrix filled
with distinct utilities of pairs (decision, object-state), give rise to own
trials of successfully accomplished applications concerning the item of
medication.
After interpreting pairs (decision, object-state) as (therapy, symptom), we
intend to prove decision-making based on the Choquet integral to extract the
optimal treatment in radiation cystitis
A Serious Game for Training in Emotion Regulation: From Design to Evaluation
No full textGames are often used as training devices in various tasks, but proper
biofeedback is more seldom used. Within an EU project it was explored how
biofeedback games can target emotion regulation and be evaluated meaningfully.
While many use games and biofeedback separately, here the focus was to combine
them. This was explored through how the games were perceived and played while
players were punished in-game, based on their physiological activity. By
implementing games and study the interaction patterns in experimental settings,
primarily correlational data was acquired. The results suggest that targeting
cognitive constructs has to be validated for each specific game, since game
strategies can influence the activation of the cognitive constructs
Crowdsourcing Based Subjective Quality Assessment of Adaptive Video Streaming
No full textIn order to cater for user’s quality of experience (QoE) requirements, HTTP
adaptive streaming (HAS) based solutions of video services have become popular
recently. User QoE feedback can be instrumental in improving the capabilities
of such services. Perceptual quality experiments that involve humans are
considered to be the most valid method of the assessment of QoE. Besides
lab-based subjective experiments, crowdsourcing based subjective assessment of
video quality is gaining popularity as an alternative method. This paper
presents insights into a study that investigates perceptual preferences of
various adaptive video streaming scenarios through crowdsourcing based
subjective quality assessment
A robust method for estimating synchronization and delay of audio and video for communication services
No full textOne of the main contributions to the quality of experience in streaming
services or in two-way communication of audio and video applications is
synchronization. This has been shown in several studies and experiments but
methods to measure synchronization are less frequent, especially for situations
without internal access to the application and independent of platform and
device. In this paper we present a method for measuring synchronization
skewness as well as delay for audio and video. The solution incorporates audio
and video reference streams, where audio and video frames are marked with frame
numbers which are decoded on the receiver side to enable calculation of
synchronization and delay.
The method has been verified in a two-way communication application in a
transparent network with and without inserting known delays, as well as in a
network with 5 and 10 % packet loss levels. The method can be used for both
streaming and two-way communication services, both with and without access to
the internal structures, and enables measurements of applications running on
e.g. smartphones, tablets, and laptops under various conditions