69,332 research outputs found
A Product Line Systems Engineering Process for Variability Identification and Reduction
Software Product Line Engineering has attracted attention in the last two
decades due to its promising capabilities to reduce costs and time to market
through reuse of requirements and components. In practice, developing system
level product lines in a large-scale company is not an easy task as there may
be thousands of variants and multiple disciplines involved. The manual reuse of
legacy system models at domain engineering to build reusable system libraries
and configurations of variants to derive target products can be infeasible. To
tackle this challenge, a Product Line Systems Engineering process is proposed.
Specifically, the process extends research in the System Orthogonal Variability
Model to support hierarchical variability modeling with formal definitions;
utilizes Systems Engineering concepts and legacy system models to build the
hierarchy for the variability model and to identify essential relations between
variants; and finally, analyzes the identified relations to reduce the number
of variation points. The process, which is automated by computational
algorithms, is demonstrated through an illustrative example on generalized
Rolls-Royce aircraft engine control systems. To evaluate the effectiveness of
the process in the reduction of variation points, it is further applied to case
studies in different engineering domains at different levels of complexity.
Subject to system model availability, reduction of 14% to 40% in the number of
variation points are demonstrated in the case studies.Comment: 12 pages, 6 figures, 2 tables; submitted to the IEEE Systems Journal
on 3rd June 201
Privacy-Preserving Reengineering of Model-View-Controller Application Architectures Using Linked Data
When a legacy system’s software architecture cannot be redesigned, implementing
additional privacy requirements is often complex, unreliable and
costly to maintain. This paper presents a privacy-by-design approach to
reengineer web applications as linked data-enabled and implement access
control and privacy preservation properties. The method is based on the
knowledge of the application architecture, which for the Web of data is
commonly designed on the basis of a model-view-controller pattern. Whereas
wrapping techniques commonly used to link data of web applications duplicate
the security source code, the new approach allows for the controlled
disclosure of an application’s data, while preserving non-functional properties
such as privacy preservation. The solution has been implemented
and compared with existing linked data frameworks in terms of reliability,
maintainability and complexity
Defending Against Firmware Cyber Attacks on Safety-Critical Systems
In the past, it was not possible to update the underlying software in many industrial control devices. Engineering
teams had to ‘rip and replace’ obsolete components. However, the ability to make firmware updates has provided
significant benefits to the companies who use Programmable Logic Controllers (PLCs), switches, gateways and
bridges as well as an array of smart sensor/actuators. These updates include security patches when vulnerabilities are
identified in existing devices; they can be distributed by physical media but are increasingly downloaded over
Internet connections. These mechanisms pose a growing threat to the cyber security of safety-critical applications,
which are illustrated by recent attacks on safety-related infrastructures across the Ukraine. Subsequent sections
explain how malware can be distributed within firmware updates. Even when attackers cannot reverse engineer the
code necessary to disguise their attack, they can undermine a device by forcing it into a constant upload cycle where
the firmware installation never terminates. In this paper, we present means of mitigating the risks of firmware attack
on safety-critical systems as part of wider initiatives to secure national critical infrastructures. Technical solutions,
including firmware hashing, must be augmented by organizational measures to secure the supply chain within
individual plants, across companies and throughout safety-related industries
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Vocational education and training (VET) for ICT employment: preparing women for work
This paper attempts to articulate the problematic issues that contribute to women’s participation or lack of it in ICT technical and vocational education and training (VET ). This is the training and education that prepares women for employment in IT jobs, or helps re-skill or up-skill them once they are employed. The paper has three sections. The maps out what is encompassed by the category (technical and) vocational education and training (VET), to give some idea of the context and institutions in which the specific activity of ICT VET takes place, focusing on non-university institutions. The second section reviews data about women’s participation in ICT VET from four countries and one large commercial training provider in order to explore whether different educational systems and contexts produce differences in women’s participation in ICT VET. The third and final section of the paper explores the main factors that contribute to differences in women’s participation. It also raises questions about whether those active in initiatives for women in ICT training are using the best categories to understand the nature of women’s engagement in ICTs, or whether it would be more useful for gender equity to reconceptualise the nature of ICT work and skills
Transitioning Applications to Semantic Web Services: An Automated Formal Approach
Semantic Web Services have been recognized as a promising technology that exhibits huge commercial potential, and attract significant attention from both industry and the research community. Despite expectations being high, the industrial take-up of Semantic Web Service technologies has been slower than expected. One of the main reasons is that many systems have been developed without considering the potential of the web in integrating services and sharing resources. Without a systematic methodology and proper tool support, the migration from legacy systems to Semantic Web Service-based systems can be a very tedious and expensive process, which carries a definite risk of failure. There is an urgent need to provide strategies which allow the migration of legacy systems to Semantic Web Services platforms, and also tools to support such a strategy. In this paper we propose a methodology for transitioning these applications to Semantic Web Services by taking the advantage of rigorous mathematical methods. Our methodology allows users to migrate their applications to Semantic Web Services platform automatically or semi-automatically
Millimeter-wave Wireless LAN and its Extension toward 5G Heterogeneous Networks
Millimeter-wave (mmw) frequency bands, especially 60 GHz unlicensed band, are
considered as a promising solution for gigabit short range wireless
communication systems. IEEE standard 802.11ad, also known as WiGig, is
standardized for the usage of the 60 GHz unlicensed band for wireless local
area networks (WLANs). By using this mmw WLAN, multi-Gbps rate can be achieved
to support bandwidth-intensive multimedia applications. Exhaustive search along
with beamforming (BF) is usually used to overcome 60 GHz channel propagation
loss and accomplish data transmissions in such mmw WLANs. Because of its short
range transmission with a high susceptibility to path blocking, multiple number
of mmw access points (APs) should be used to fully cover a typical target
environment for future high capacity multi-Gbps WLANs. Therefore, coordination
among mmw APs is highly needed to overcome packet collisions resulting from
un-coordinated exhaustive search BF and to increase the total capacity of mmw
WLANs. In this paper, we firstly give the current status of mmw WLANs with our
developed WiGig AP prototype. Then, we highlight the great need for coordinated
transmissions among mmw APs as a key enabler for future high capacity mmw
WLANs. Two different types of coordinated mmw WLAN architecture are introduced.
One is the distributed antenna type architecture to realize centralized
coordination, while the other is an autonomous coordination with the assistance
of legacy Wi-Fi signaling. Moreover, two heterogeneous network (HetNet)
architectures are also introduced to efficiently extend the coordinated mmw
WLANs to be used for future 5th Generation (5G) cellular networks.Comment: 18 pages, 24 figures, accepted, invited paper
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