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1.
The I/O subsystem has become a major source of energy consumption in a hard real-time monitoring and control system. To reduce
its energy consumption without missing deadlines, a dynamic power management (DPM) policy must carefully consider the power
parameters of a device, such as its break-even time and wake-up latency, when switching off idle devices. This problem becomes
extremely complicated when dynamic voltage scaling (DVS) is applied to change the execution time of a task. In this paper,
we present COLORS, a composite low-power scheduling framework that includes DVS in a DPM policy to maximize the energy reduction
on the I/O subsystem. COLORS dynamically predicts the earliest-access time of a device and switches off idle devices. It makes
use of both static and dynamic slack time to extend the execution time of a task by DVS, in order to create additional switch-off
opportunities. Task workloads, processor profiles, and device characteristics all impact the performance of a low-power real-time
algorithm. We also identify a key metric that primarily determines its performance. The experimental results show that, compared
with previous work, COLORS achieves additional energy reduction up to 20%, due to the efficient utilization of slack time.
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2.
Reducing power consumption is quickly becoming a first-class optimization metric for many high-performance parallel computing
platforms. One of the techniques employed by many prior proposals along this direction is voltage scaling and past research
used it on different components such as networks, CPUs, and memories. In contrast to most of the existent efforts on voltage
scaling that target a single component (CPU, network or memory components), this paper proposes and experimentally evaluates
a voltage/frequency scaling algorithm that considers CPU and communication links in a mesh network at the same time. More
specifically, it scales voltages/frequencies of CPUs in the nodes and the communication links among them in a coordinated
fashion (instead of one after another) such that energy savings are maximized without impacting execution time. Our experiments
with several tree-based sparse matrix computations reveal that the proposed integrated voltage scaling approach is very effective
in practice and brings 13% and 17% energy savings over the pure CPU and pure communication link voltage scaling schemes, respectively.
The results also show that our savings are consistent with the different network sizes and different sets of voltage/frequency
levels.
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3.
This article discusses whether using warnings generated by the GNU C++ compiler can be used effectively to identify source
code files that are likely to be error prone. We analyze five industrial projects written in C++ and belonging to the telecommunication
domain. We find a significant positive correlation between the number of compiler warnings and the number of source files
changes. We use such correlation to conclude that compiler warnings may be used as an indicator for the presence of software
defects in source code. The result of this research is useful for finding defect-prone modules in newer projects, which lack
change history.
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4.
This paper describes the simulated car racing competition that was arranged as part of the 2007 IEEE Congress on Evolutionary
Computation. Both the game that was used as the domain for the competition, the controllers submitted as entries to the competition
and its results are presented. With this paper, we hope to provide some insight into the efficacy of various computational
intelligence methods on a well-defined game task, as well as an example of one way of running a competition. In the process,
we provide a set of reference results for those who wish to use the simplerace game to benchmark their own algorithms. The paper is co-authored by the organizers and participants of the competition.
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5.
Quantitative usability requirements are a critical but challenging, and hence an often neglected aspect of a usability engineering process. A case study is described where quantitative usability requirements played a key role in the development of a new user interface of a mobile phone. Within the practical constraints of the project, existing methods for determining usability requirements and evaluating the extent to which these are met, could not be applied as such, therefore tailored methods had to be developed. These methods and their applications are discussed. 相似文献
6.
The complexity of group dynamics occurring in small group interactions often hinders the performance of teams. The availability
of rich multimodal information about what is going on during the meeting makes it possible to explore the possibility of providing
support to dysfunctional teams from facilitation to training sessions addressing both the individuals and the group as a whole.
A necessary step in this direction is that of capturing and understanding group dynamics. In this paper, we discuss a particular
scenario, in which meeting participants receive multimedia feedback on their relational behaviour, as a first step towards
increasing self-awareness. We describe the background and the motivation for a coding scheme for annotating meeting recordings
partially inspired by the Bales’ Interaction Process Analysis. This coding scheme was aimed at identifying suitable observable
behavioural sequences. The study is complemented with an experimental investigation on the acceptability of such a service.
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7.
Listening to music on personal, digital devices whilst mobile is an enjoyable, everyday activity. We explore a scheme for
exploiting this practice to immerse listeners in navigation cues. Our prototype, ONTRACK, continuously adapts audio, modifying
the spatial balance and volume to lead listeners to their target destination. First we report on an initial lab-based evaluation
that demonstrated the approach’s efficacy: users were able to complete tasks within a reasonable time and their subjective
feedback was positive. Encouraged by these results we constructed a handheld prototype. Here, we discuss this implementation
and the results of field-trials. These indicate that even with a low-fidelity realisation of the concept, users can quite
effectively navigate complicated routes.
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8.
We present an enhancement towards adaptive video training for PhoneGuide, a digital museum guidance system for ordinary camera-equipped
mobile phones. It enables museum visitors to identify exhibits by capturing photos of them. In this article, a combined solution
of object recognition and pervasive tracking is extended to a client–server-system for improving data acquisition and for
supporting scale-invariant object recognition. A static as well as a dynamic training technique are presented that preprocess
the collected object data differently and apply two types of neural networks (NN) for classification. Furthermore, the system
enables a temporal adaptation for ensuring a continuous data acquisition to improve the recognition rate over time. A formal
field experiment reveals current recognition rates and indicates the practicability of both methods under realistic conditions
in a museum.
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9.
We present a study of using camera-phones and visual-tags to access mobile services. Firstly, a user-experience study is described in which participants were both observed learning to interact with a prototype mobile service and interviewed
about their experiences. Secondly, a pointing-device task is presented in which quantitative data was gathered regarding the speed and accuracy with which participants aimed and clicked
on visual-tags using camera-phones. We found that participants’ attitudes to visual-tag-based applications were broadly positive,
although they had several important reservations about camera-phone technology more generally. Data from our pointing-device
task demonstrated that novice users were able to aim and click on visual-tags quickly (well under 3 s per pointing-device
trial on average) and accurately (almost all meeting our defined speed/accuracy tradeoff of 6% error-rate). Based on our findings,
design lessons for camera-phone and visual-tag applications are presented.
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10.
Awareness systems have attracted significant research interest for their potential to support interpersonal relationships.
Investigations of awareness systems for the domestic environment have suggested that such systems can help individuals stay
in touch with dear friends or family and provide affective benefits to their users. Our research provides empirical evidence
to refine and substantiate such suggestions. We report our experience with designing and evaluating the ASTRA awareness system,
for connecting households and mobile family members. We introduce the concept of connectedness and its measurement through
the Affective Benefits and Costs of communication questionnaire (ABC-Q). We inform results that testify the benefits of sharing
experiences at the moment they happen without interrupting potential receivers. Finally, we document the role that lightweight,
picture-based communication can play in the range of communication media available.
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11.
The paper reflects on the unique experience of social and technological development in Lithuania since the regaining of independence
as a newly reshaped society constructing a distinctive competitive IST-based model at global level. This has presented Lithuanian
pattern of how to integrate different experiences and relations between generations in implementing complex information society
approaches. The resulting programme in general is linked to the Lisbon objectives of the European Union. The experience of
transitional countries in Europe, each different but facing some common problems, may be useful to developing countries in
Africa.
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12.
There are only a few ethical regulations that deal explicitly with robots, in contrast to a vast number of regulations, which
may be applied. We will focus on ethical issues with regard to “responsibility and autonomous robots”, “machines as a replacement
for humans”, and “tele-presence”. Furthermore we will examine examples from special fields of application (medicine and healthcare,
armed forces, and entertainment). We do not claim to present a complete list of ethical issue nor of regulations in the field
of robotics, but we will demonstrate that there are legal challenges with regard to these issues.
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13.
Ohne Zusammenfassung
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14.
Research on hybrid bionic systems (HBSs) is still in its infancy but promising results have already been achieved in laboratories.
Experiments on humans and animals show that artificial devices can be controlled by neural signals. These results suggest
that HBS technologies can be employed to restore sensorimotor functionalities in disabled and elderly people. At the same
time, HBS research raises ethical concerns related to possible exogenous and endogenous limitations to human autonomy and
freedom. The analysis of these concerns requires reflecting on the availability of scientific models accounting for key aspects
of sensorimotor coordination and plastic adaptation mechanisms in the brain.
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15.
The Stanford Event Heap has been shown to provide appropriate support for constructing interactive workspace applications.
Given this success it is natural to consider the Event Heap as a platform to support other classes of Ubiquitous Computing
applications. In this paper we argue that the distributed, spontaneous nature of these applications places additional demands
on the Event Heap that require extensions to both the engineering and API. Suitable extensions are described and their use
to support a typical Ubicomp application is discussed.
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16.
In this paper, we present an Inverse Multi-Objective Robust Evolutionary (IMORE) design methodology that handles the presence
of uncertainty without making assumptions about the uncertainty structure. We model the clustering of uncertain events in
families of nested sets using a multi-level optimization search. To reduce the high computational costs of the proposed methodology
we proposed schemes for (1) adapting the step-size in estimating the uncertainty, and (2) trimming down the number of calls
to the objective function in the nested search. Both offline and online adaptation strategies are considered in conjunction
with the IMORE design algorithm. Design of Experiments (DOE) approaches further reduce the number of objective function calls
in the online adaptive IMORE algorithm. Empirical studies conducted on a series of test functions having diverse complexities
show that the proposed algorithms converge to a set of Pareto-optimal design solutions with non-dominated nominal and robustness
performances efficiently.
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17.
The purposes of this study are (a) to establish a measurement for evaluating conversational impressions of group discussions,
and (b) to make an exploratory investigation on their interactional processes which may affect to form those impressions.
The impression rating and factor analysis undertaken first give us four factors concerning conversational impressions of “focus
group interviews (FGIs)”: conversational activeness, conversational sequencing, the attitudes of participants and the relationships
of participants. In relation to the factors of conversational activeness and conversational sequencing in particular, the
microanalysis of four selected topical scenes from our database further shows that the behavior of the moderator and the interviewees
is organized not independently but with reference to each other. The study thus emphasizes the importance of the integration
of quantitative and qualitative approaches towards human interactions.
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18.
To get the maximum benefit from ambient intelligence (AmI), we need to anticipate and react to possible drawbacks and threats
emerging from the new technologies in order to devise appropriate safeguards. The SWAMI project took a precautionary approach
in its exploration of the privacy risks in AmI and sought ways to reduce them. It constructed four “dark scenarios” showing
possible negative implications of AmI, notably for privacy protection. Legal analysis of the depicted futures showed the shortcomings
of the current legal framework in being able to provide adequate privacy protection in the AmI environment. In this paper,
the authors, building upon their involvement in SWAMI research as well as the further advancement of EU privacy analysis,
identify various outstanding issues regarding the legal framework that still need to be resolved in order to deal with AmI
in an equitable and efficacious way. This article points out some of the lacunae in the legal framework and postulates several
privacy-specific safeguards aimed at overcoming them.
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19.
Assumptions are frequently made during requirements analysis of a system about the trustworthiness of its various components
(including human components). These trust assumptions, whether implicit or explicit, affect the scope of the analysis, derivation
of security requirements, and in some cases how functionality is realized. This paper presents trust assumptions in the context
of analysis of security requirements. A running example shows how trust assumptions can be used by a requirements engineer
to help define and limit the scope of analysis and to document the decisions made during the process. The paper concludes
with a case study examining the impact of trust assumptions on software that uses the secure electronic transaction specification.
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20.
An important area of Human Reliability Assessment in interactive systems is the ability to understand the causes of human
error and to model their occurrence. This paper investigates a new approach to analysis of task failures based on patterns
of operator behaviour, in contrast with more traditional event-based approaches. It considers, as a case study, a formal model
of an Air Traffic Control system operator’s task which incorporates a simple model of the high-level cognitive processes involved.
The cognitive model is formalised in the CSP process algebra. Various patterns of behaviour that could lead to task failure
are described using temporal logic. Then a model-checking technique is used to verify whether the set of selected behavioural
patterns is sound and complete with respect to the definition of task failure. The decomposition is shown to be incomplete
and a new behavioural pattern is identified, which appears to have been overlooked in the informal analysis of the problem.
This illustrates how formal analysis of operator models can yield fresh insights into how failures may arise in interactive
systems.
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