Swedish Institute of Computer Science Publications Database
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Search-based Testing for Embedded Telecommunication Software with Complex Input Structures: An Industrial Case Study
No full textIn this paper, we discuss the application of search-based software testing techniques for unit level testing of a real-world telecommunication middleware at Ericsson. Input data for the system under test consists of nested data structures, and includes non-trivial variables such as uninitialized pointers. Our current implementation analyzes the existing test cases to discover how to handle pointers, set global system parameters, and any other setup code that needs to run before the actual test case. Hill climbing (HC) and (1+1) evolutionary algorithm (EA) metaheuristic search algorithms are used to generate input data for branch coverage. We compare HC, (1+1)EA, and random search as a baseline of performance with respect to effectiveness, measured as branch coverage, and efficiency, measured as number of executions needed. Difficulties arising from the specialized execution environment and the adaptations for handling these problems are also discussed
Linking Prefixes and Suffixes for Constraints Encoded Using Automata with Accumulators
No full textConsider a constraint on a sequence of variables functionally determining a result variable that is unchanged under reversal of the sequence. Most such constraints have a compact encoding via an automaton augmented with accumulators, but it is unknown how to maintain domain consistency efficiently for most of them. Using such an automaton for such a constraint, we derive an implied constraint between the result variables for a sequence, a prefix thereof, and the corresponding suffix. We show the usefulness of this implied constraint in constraint solving, both by local search and by propagation-based systematic search
Impediments for Automated Testing - An Empirical Analysis of a User Support Discussion Board
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The Design of an Auditory Alarm Concept for a Paper Mill Control Room
No full textAuditory alarms are common in industrial control rooms. Sound has certain advantages over other alarm modes. Salient auditory stimuli effectively capture and guide attention, regardless of the operators’ visual focus. Sound can also convey detailed information. However, auditory alarms are often carelessly implemented, utilising sounds that are too loud, too numerous, and too confusing. The aim of this work was to develop a concept to enhance the auditory alarms in a control room. Before the concept was developed, a study involving 21 operators evaluated the state of the alarm sounds. The results indicated a poor design and confirmed certain well-known issues with alarm sounds. The concept included new alarm sounds, spatial presentation of the sounds, and alarm repetition intervals. The sounds are based on a new design principle in which each alarm sound composes two parts. One conveys urgency information, and the other contains information associated with the section in question. The design process involved 24 control-room operators and 13 design iterations, which were used to refine the concept. An evaluation involving 20 operators was conducted to examine the appropriateness of the concept. The results demonstrate that the developed concept increases operator effectiveness and acceptance as well as the overall sound environment
An Auditory Display to Convey Urgency Information in Industrial Control Rooms
No full textAuditory warning signals are common features in industrial control rooms. Finding sound signals that convey higher degrees of urgency while keeping the potential for annoyance low is challenging. In the present study, evaluations were performed on four different types of auditory displays. The displays were all designed to convey three levels of urgency. The examination focused on the following questions: (1) “How reliably can the operators identify the three levels of urgency?” and (2) “How annoying do the operators find the sound signals?”. Fourteen operators participated in the study. For every signal within each auditory display, the participants were asked to rate the level of urgency and annoyance. The results show that one can design auditory displays that employ appropriate urgency mapping while the perceived annoyance is kept at a low level. The work also suggests that involving the end users in the design process could be advantageous
Bringing Visibility in the Clouds : using Security, Transparency and Assurance Services
No full textThe evolution of cloud computing allows the provisioning of IT resources over the Internet and promises many benefits for both - the service users and providers. Despite various benefits offered by cloud based services, many users hesitate in moving their IT systems to the cloud mainly due to many new security problems introduced by cloud environments. In fact, the characteristics of cloud computing become basis of new problems, for example, support of third party hosting introduces loss of user control on the hardware; similarly, on-demand availability requires reliance on complex and possibly insecure API interfaces; seamless scalability relies on the use of sub-providers; global access over public Internet exposes to broader attack surface; and use of shared resources for better resource utilization introduces isolation problems in a multi-tenant environment. These new security issues in addition to existing security challenges (that exist in today's classic IT environments) become major reasons for the lack of user trust in cloud based services categorized in Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS) or Infrastructure-as-a-Service (IaaS).
The focus of this thesis is on IaaS model which allows users to lease IT resources (e.g. computing power, memory, storage, etc.) from a public cloud to create Virtual Machine (VM) instances. The public cloud deployment model considered in this thesis exhibits most elasticity (i.e. degree of freedom to lease/release IT resources according to user demand) but is least secure as compared to private or hybrid models. As a result, public clouds are not trusted for many use cases which involve processing of security critical data such as health records, financial data, government data, etc. However, public IaaS clouds can also be made trustworthy and viable for these use cases by providing better transparency and security assurance services for the user. In this thesis, we consider such assurance services and identify security aspects which are important for making public clouds trustworthy. Based upon our findings, we propose solutions which promise to improve cloud transparency thereby realizing trustworthy clouds.
The solutions presented in this thesis mainly deal with the secure life cycle management of the user VM which include protocols and their implementation for secure VM launch and migration. The VM launch and migration solutions ensure that the user VM is always hosted on correct cloud platforms which are setup according to a profile that fulfills the use case relevant security requirements. This is done by using an automated platform security audit and certification mechanism which uses trusted computing and security automation techniques in an integrated solution. In addition to provide the assurance about the cloud platforms, we also propose a solution which provides assurance about the placement of user data in correct and approved geographical locations which is critical from many legal aspects and usually an important requirement of the user. Finally, the assurance solutions provided in this thesis increase cloud transparency which is important for user trust and to realize trustworthy clouds
Hierarchical Multi-label Conditional Random Fields for Aspect-Oriented Opinion Mining
No full textA common feature of many online review sites is the use of an overall rating that summarizes the opinions expressed in a review. Unfortunately, these document-level ratings do not provide any information about the opinions contained in the review that concern a specific aspect (e.g., cleanliness) of the product being reviewed (e.g., a hotel). In this paper we study the finer-grained problem of aspect-oriented opinion mining at the sentence level, which consists of predicting, for all sentences in the review, whether the sentence expresses a positive, neutral, or negative opinion (or no opinion at all) about a specific aspect of the product. For this task we propose a set of increasingly powerful models based on conditional random fields (CRFs), including a hierarchical multi-label CRFs scheme that jointly models the overall opinion expressed in the review and the set of aspect-specific opinions expressed in each of its sentences. We evaluate the proposed models against a dataset of hotel reviews (which we here make publicly available) in which the set of aspects and the opinions expressed concerning them are manually annotated at the sentence level. We find that both hierarchical and multi-label factors lead to improved predictions of aspect-oriented opinions
Designing for Movement – the Case of Sports
No full textWe have identified six themes we identified as interesting for future work in movement based interaction design for sports: the central position of the subjective feeling, the core of sports is enough, feeling did not prevent injury, non-interpretive representations, the shortcomings of logging biodata, and temporality of feedback. The themes are grounded in technical explorations for golf and running and a set of interviews with athletes. Here, we outline findings from our work to illustrate these themes
Opportunistic Routing in Low Duty-Cycle Wireless Sensor Networks
No full textOpportunistic routing is widely known to have substantially better performance than unicast routing in wireless networks with
lossy links. However, wireless sensor networks are heavily duty-cycled, i.e. they frequently enter sleep states to ensure long
network life-time. This renders existing opportunistic routing schemes impractical, as they assume that nodes are always
awake and can overhear other transmissions. In this paper we introduce ORW, a practical opportunistic routing scheme
for wireless sensor networks. ORW uses a novel opportunistic routing metric, EDC, that reflects the expected number of
duty-cycled wakeups that are required to successfully deliver a packet from source to destination. We devise distributed
algorithms that find the EDC-optimal forwarding and demonstrate using analytical performance models and simulations
that EDC-based opportunistic routing results in significantly reduced delay and improved energy efficiency compared to the
traditional unicast routing. We compare the performance of the ORW protocol with other alternatives in both simulations
and testbed-based experiments. Our results show that ORW reduces radio duty cycles on average by 50% (up to 90% on
individual nodes) and delays by 30% to 90% when compared to the state of the art