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Evaluating strategies for study selection in systematic literature studies
No full textContext: The study selection process is critical to improve the reliability of
secondary studies. Goal: To evaluate the selection strategies commonly employed
in secondary studies in software engineering. Method: Building on these strate-
gies, a study selection process was formulated and evalu- ated in a systematic
review. Results: The selection process used a more inclusive strategy than the
one typically used in secondary studies, which led to additional relevant
articles. Conclusions: The results indicates that a good-enough sam- ple could
be obtained by following a less inclusive but more efficient strategy, if the
articles identified as relevant for the study are a representative sample of
the population, and there is a homogeneity of results and quality of the
articles
Preliminary Results from the Software Product Management State-of-Practice Survey
No full textSoftware product management (SPM) as a discipline includes many practices like
product and release planning, market analysis, roadmapping, and product
lifecycle management. Product management frameworks prescribe these practices
but companies seldom adopt all of them. We conducted a state-of-practice survey
with the aim to investigate how companies adopt SPM practices and how this
practical experience fits together with the framework suggested by
International Software Product Management Association (ISPMA). The results of
this study showed that ISPMA SPM Framework describes core product management
practices well but the impact of product management practices to the final
product success remains ambiguous
In press: Handover of managerial responsibilities in global software development: a case study of source code evolution and quality
No full textStudies report on the negative effect on quality in global software development
(GSD) due to communication and coordination-related challenges. However,
empirical studies reporting on the magnitude of the effect are scarce. This
paper presents findings from an embedded explanatory case study on the change
in quality over time, across multiple releases, for products that were
developed in a GSD setting. The GSD setting involved periods of distributed
development between geographically dispersed sites as well as a handover of
project management responsibilities between the involved sites. Investigations
were performed on two medium-sized products from a company that is part of a
large multinational corporation. Quality is investigated quantitatively using
defect data and measures that quantify two source code properties, size and
complexity. Observations were triangulated with subjective views from company
representatives. There were no observable indications that the distribution of
work or handover of project management responsibilities had an impact on
quality on both products. Among the product-, process- and people-related
success factors, we identified well-designed product architectures, early
handover planning and support from the sending site to the receiving site after
the handover and skilled employees at the involved sites. Overall, these
results can be useful input for decision-makers who are considering
distributing development work between globally dispersed sites or handing over
project management responsibilities from one site to another. Moreover, our
study shows that analyzing the evolution of size and complexity properties of a
product’s source code can provide valuable information to support
decision-making during similar projects. Finally, the strategy used by the
company to relocate responsibilities can also be considered as an alternative
for software transfers, which have been linked with a decline in efficiency,
productivity and quality
MIMO Amplify-and-Forward Relay Systems with Dissimilar Channel Characteristics
No full textIn this paper, we investigate the asymmetric property of multiple-input
multiple-output (MIMO) dual-hop amplify-and- forward (AF) relay networks. We
consider the difference of the two hops in terms of both fading channels and
scattering environment. In particular, we analyze the symbol error probability
(SEP) of a MIMO orthogonal space-time block code (OSTBC) AF relay network in
which the first and second hop undergo Rayleigh fading with a rich-scattering
environment and Nakagami-m fading with a poor-scattering environment,
respectively. Moreover, an asymptotic SEP expression yielding
insights on the diversity gain is also obtained
Identifying organizational barriers-A case study of usability work when developing software in the automation industry
No full textThis study investigates connections between usability efforts and
organizational factors. This is an important field of research which so far
appears to be insufficiently studied and discussed. It illustrates problems
when working with software engineering tasks and usability requirements. It
deals with a large company that manufactures industrial robots with an advanced
user interface, which wanted to introduce usability KPIs, to improve product
quality. The situation in the company makes this difficult, due to a
combination of organizational and behavioural factors that led to a "wicked
problem" that caused conflicts, breakdowns and barriers. Addressing these
problems requires a holistic view that places context in the foreground and
technological solutions in the background. Developing the right product
requires communication and collaboration between multiple stakeholders. The
inclusion of end users, who fully understand their own work context, is vital.
Achieving this is dependent on organizational change, and management
commitment. One step to beginning this change process may be through studying
ways to introduce user-centred design processes
A Systems Perspective on ISO 26000
No full textSince its publication in 2010, ISO 26000 has become the de-facto standard of
Corporate Social Responsibility (CSR). While not a certifiable standard in ISO
terms, but rather a guidance document, it has become the document many
corporations use as their basis for CSR work. ISO 26000 claims that the
objective of social responsibility is to contribute to sustainable development,
using the Brundtland definition – development, which meets the needs the
present without compromising the ability of future generations to meet their
own needs – as the basis for sustainable development.
However, the Brundtland definition, while commonly referred to, is not
sufficiently concrete to give guidance for strategic planning and action in
businesses, municipalities and society at large. Therefore it is helpful to
supplement the Brundtland definition with a framework that allows for this
concrete and strategic planning, e.g. the Framework for Strategic Sustainable
Development (FSSD). The FSSD is based on a principled definition of
sustainability, defining social and ecological sustainability in more
operational terms, and includes guidelines for how to contribute systematically
and strategically to fulfillment of this definition. It is a transdisciplinary
framework built on insights from systems thinking and has been continuously
developed as well as used and improved in organizations all over the world for
the last two decades. A particular recent development focus has been the social
dimension of sustainability, with new insights based on the application of
systems thinking to social systems having been recently presented.
In this paper, these new insights are used to analyze and evaluate ISO 26000´s
contribution to sustainability, highlighting both benefits and shortcomings of
ISO 26000 from a social systems and strategic sustainable development
perspective. Main points include that, while ISO 26000 is comprehensive in it´s
scope and provides a vast achievement in terms of international consensus
building around the essential issues in CSR, it is not based on a scientific
understanding of social and ecological systems and is therefore a document
highlighting current societal expectations rather than a document allowing
organizations to innovate, plan, act and monitor long-term for sustainability.
The paper further points out examples of aspects of sustainability that are
likely to become issues in the future, but that are currently not covered by
the ISO guidance. Finally, the paper points at research needed to explore more
in detail in which ways ISO 26000 can support strategic working towards
sustainability, and in which areas other tools are necessary
A proposed model for prediction of survival based on a follow-up study in unresectable pancreatic cancer.
No full textOBJECTIVES:
To define an easy-to-use model for prediction of survival time in patients with
unresectable pancreatic cancer in order to optimise patient' care.
DESIGN:
An observational retrospective study on patients with unresectable pancreatic
cancer. The initial radiographs at presentation of symptoms were reviewed and
the maximum diameter of the primary tumour was determined. The occurrence of
liver metastases and performance status that determines initiation of
chemotherapy was also used in the regression analysis to identify prognostic
subgroups.
SETTING:
County hospital in south-east of Sweden.
POPULATION:
Consecutive patients with unresectable pancreatic cancer who were diagnosed
between January 2003 and May 2010 (n=132).
MAIN OUTCOME MEASURES:
Statistical analyses were performed using Stata V.13. Survival time was
assessed with Kaplan-Meier analysis, log-rank test for equality of survivor
functions and Cox regression for calculation of individual hazard based on
tumour diameter, presence of liver metastases and initiation of chemotherapy
treatment according to patient performance status.
RESULTS:
The individual hazard was log h=0.357 tumour size+1.181 liver metastases-0.989
performance status/chemotherapy. Three prognostic groups could be defined: a
low-risk group with a median survival time of 6.7 (IQR 9.7) months, a
medium-risk group with a median survival time of 4.5 (IQR 4.5) months and a
high-risk group with a median survival time of 1.2 (IQR 1.7) months.
CONCLUSIONS:
The maximum diameter of the primary tumour and the presence of liver metastases
found at the X-ray examination of patients with pancreatic cancer, in
conjunction with whether or not chemotherapy is initiated according to
performance status, predict the survival time for patients who do not undergo
surgical resection. The findings result in an easy-to-use model for predicting
the survival time
Performance evaluation and prediction of open source speech engine on multicore processors
No full textThis paper quantifies the performance of the core part of voice driven web
using free and open source speech engine; the speech engine which is very high
computation demanding, it consists of Automatic Speech Recognition (ASR) and
Text To Speech (TTS). Two open source programs, Sphinx-4 and FreeTTS-1.2.2 are
used for ASR and TTS respectively. These two programs are executed on 2
different hardware multicore processors with 4 hyperthreaded cores, and 8 cores
respectively. The response time with respect to the load variance and the
number of cores is measured and predicted using a linear regression model. The
results show that, the response time is linear with respect to the input
length, this property can be used to directly predict the response for any
input length. Moreover, though the response time and the speed up increases as
the number of cores increases, the regression coefficients and number of
threads reveal that ASR benefits from multicore. The speedup factor for ASR is
1.56 for 8 cores. However for FreeTTS, though being sequential the speed up
from the program itself is insignificant, there is about 1. 43 speedup for 8
cores, that comes from the system's contribution. Our findings show that the
generalization of the results for multicore processor does not apply to
hyperthreading. This paper presents the investigation that is useful for
educators, researchers, and applications' developer in voice based applications
'domain
Fast Time-Domain Algorithms for UWB Bistatic SAR Processing
No full textTwo fast time-domain algorithms are introduced for ultrawideband-ultrawidebeam
(UWB) bistatic synthetic aperture radar (SAR) processing; they are bistatic
fast backprojection (BiFBP) and bistatic fast factorized backprojection
(BiFFBP). Both algorithms process radar echoes on a subaperture and subimage
basis in order to minimize processing time. They are shown to work with any
configuration of bistatic SAR. They also own time-domain characteristics, which
are essential for UWB radar signal processing. BiFBP and BiFFBP are
experimented successfully on the CARABAS-II simulated data
On Dynamic Spectrum Access in Cognitive Radio Networking
No full textThe exploding increase of wireless communications combined with the existing
inefficient usage of the licensed spectrum gives a strong impetus to the
development and standardization of cognitive radio networking and
communications. In this dissertation, a framework for Dynamic Spectrum Access
(DSA) is first presented, which is the enabling technology for increasing the
spectral efficiency of wireless communications. Based on that, Cognitive Radio
(CR) can be developed as an enabling technology for supporting the DSA, which
means that the wireless users are provided with enhanced capability for sensing
the operating radio environment and for exploiting the network side information
obtained from this sensing.
The DSA concept means that the users of a wireless system are divided into a
multi-tiered hierarchy with the primary users (PUs) entitled to protection and
with cognitive radio capable secondary users (SUs). The improved spectrum
efficiency is obtained by means of a medium access control protocol with
knowledge about the statistical properties or available local information of
the channels already occupied by PUs as well as knowledge about the
interference tolerance within which the interference to PUs is kept to a given
level. Related to this, emphasis is laid on the protocol capability to
determine the efficiency of the secondary sharing of spectrum. Based on the
type of available local information, the capacity of opportunistic
communication is investigated for three models. These are: with dynamic,
distributed channels information; with dynamic, parallel channels information;
and under a dynamic sub-channels allocation scheme.
The results indicate that this capacity is robust with reference to the
uncertainty associated with localized sensing of distributed dynamic channels
and with timely sensing of parallel dynamic channels. The extension to dynamic
parallel sub-channels enables resource allocation to be carried out in
sub-channels. The analytical results on the performance of sub-channel
allocation indicate a robust traffic capacity in terms of blocking probability,
drop-out probability and delay performance as function of PUs traffic loads