Physiologic responses to loud tones in Vietnam veterans with posttraumatic stress disorder.

The authors evaluated eyeblink and autonomic components of the acoustic startle response in combat-related posttraumatic stress disorder (PTSD). Thirty-seven Vietnam combat veterans with current PTSD and 19 combat veterans without PTSD were exposed to 15 consecutive 95-dB, 500-ms, 1000-Hz tones with 0-ms rise and fall times, while orbicularis oculi electromyogram, skin conductance, and heart rate responses were measured. PTSD veterans produced larger averaged electromyographic and heart rate responses, and a slower decline in skin conductance responses, across the 15 tone presentations compared to non-PTSD veterans. Results of this study provide laboratory support for an exaggerated startle response in PTSD and replicate and extend previous findings of increased autonomic responses to loud tone stimuli in this disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Loop summarization using state and transition invariants

This paper presents algorithms for program abstraction based on the principle of loop summarization, which, unlike traditional program approximation approaches (e.g., abstract interpretation), does not employ iterative fixpoint computation, but instead computes symbolic abstract transformers with respect to a set of abstract domains. This allows for an effective exploitation of problem-specific abstract domains for summarization and, as a consequence, the precision of an abstract model may be tailored to specific verification needs. Furthermore, we extend the concept of loop summarization to incorporate relational abstract domains to enable the discovery of transition invariants, which are subsequently used to prove termination of programs. Well-foundedness of the discovered transition invariants is ensured either by a separate decision procedure call or by using abstract domains that are well-founded by construction. We experimentally evaluate several abstract domains related to memory operations to detect buffer overflow problems. Also, our light-weight termination analysis is demonstrated to be effective on a wide range of benchmarks, including OS device drivers.     

„Deal of the Day“-Plattformen: Was treibt die Kundenloyalität?

“Deal of the Day” (DoD) platforms have quickly become popular by offering savings on local services, products and vacations. For merchants, these platforms represent a new marketing channel to advertise their products and services and attract new customers. DoD platform providers, however, struggle to maintaining a stable market share and profitability, because entry and switching costs are low. To sustain a competitive market position, DoD providers are looking for ways to build a loyal customer base. However, research examining the determinants of user loyalty in this novel context is scarce. To fill this gap, this study employs Grounded Theory methodology to develop a conceptual model of customer loyalty to a DoD provider. In the next step, qualitative insights are enriched and validated using quantitative data obtained in a survey with 202 DoD users. We find that customer loyalty is in large part driven by monetary incentives, but can be eroded if impressions from merchant encounter are below expectations. In addition, enhancing the share of deals relevant for consumers, i.e. signal-to-noise ratio, and mitigating perceived risks of a transaction emerge as challenges. Beyond theoretical value, our results offer practical insights into how customer loyalty to a DoD provider can be promoted.     

The effect of stimulus modality on signal detection: implications for assessing the safety of in-vehicle technology

OBJECTIVE: This study examined the effect of two in-vehicle information systems (IVIS) on signal detection in the visual, auditory, and tactile modalities; established whether the detrimental effects of an IVIS on driving could be quantified by these detection tasks; and examined the effect of stimulus modality on signal detection. BACKGROUND: The peripheral detection task has been used widely for assessing the effects of an IVIS on driving. However, performance on this task relies on drivers' ability to see a series of LEDs, which can be problematic in field tests (e.g., on sunny days). METHOD: Participants responded to one of three detection tasks during a simulated driving experiment. The effect of IVIS interaction on these detection tasks was also measured. Reduced performance in the detection tasks was assumed to indicate a decline in drivers' ability to handle sudden events in the driving task. RESULTS: Response time to all detection tasks increased by around 200 ms when drivers performed the IVIS tasks, as compared with baseline driving. Analyses of variance and comparison of effect sizes showed the effects of these two IVISs to be the same across the three detection tasks. CONCLUSION: These detection tasks are useful for quantifying the safety of an IVIS during driving. The absence of a difference in signal detection by modality suggests that performance on these tasks relies on general attentional resources and is not modality specific. APPLICATION: The signal detection tasks employed here should be further investigated for their suitability in assessing the safety of in-vehicle systems.     

Attributions of Responsibility Toward Computing Technology: The Role of Interface Social Cues and User Gender

This study examined how social cues in an interface and user gender affected attributions of responsibility for the process and outcomes of interacting with a computer. Using a 2 × 2 between-subjects laboratory design, 391 participants were randomly assigned to work with a computer that utilized either a traditional interface or an interface designed to include higher social cues. The results of this study indicated that those who interacted with the interface with greater social cues made greater attributions of responsibility to the computer. In addition, women were more likely to ascribe responsibility to the computer. Results did not support an interaction between gender and interface design. Implications for theory and practice are discussed.     

Logics with Group Announcements and Distributed Knowledge: Completeness and Expressive Power

Journal of Logic, Language and Information - Public announcement logic (PAL) is an extension of epistemic logic with dynamic operators that model the effects of all agents simultaneously and...     

Data-driven visualization and group analysis of multichannel EEG coherence with functional units

A typical data-driven visualization of electroencephalography (EEG) coherence is a graph layout, with vertices representing electrodes and edges representing significant coherences between electrode signals. A drawback of this layout is its visual clutter for multichannel EEG. To reduce clutter, we define a functional unit (FU) as a data-driven region of interest (ROI). An FU is a spatially connected set of electrodes recording pairwise significantly coherent signals, represented in the coherence graph by a spatially connected clique. Earlier we presented two methods to detect FUs: a maximal clique based (MCB) method (time complexity O(3n/3), with n being the number of vertices) and a more efficient watershed based (WB) method (time complexity O (n2 log n)). To reduce the potential over-segmentation of the WB method, we introduce here an improved WB (IWB) method (time complexity O(n2 log n)). The IWB method merges basins representing FUs during the segmentation if they are spatially connected and if their union is a clique. The WB and IWB methods are both up to a factor of 100,000 faster than the MCB method for a typical multichannel setting with 128 EEG channels, thus making interactive visualization of multichannel EEG coherence possible. Results show that considering the MCB method as the gold standard, the difference between IWB and MCB FU maps is smaller than between WB and MCB FU maps. We also introduce two novel group maps for data-driven group analysis as extensions of the IWB method. First, the group mean coherence map preserves dominant features from a collection of individual FU maps. Second, the group FU size map visualizes the average FU size per electrode across a collection of individual FU maps. Finally, we employ an extensive case study to evaluate the IWB FU map and the two new group maps for data-driven group analysis. Results, in accordance with the conventional findings, indicate differences in EEG coherence between younger and older adults. However, they also suggest that an initial selection of hypothesis-driven ROIs could be extended with additional data-driven ROIs.     

Adolescents' motivation toward the environment: Age-related trends and correlates.

From a self-determination perspective, we attempted to replicate previous findings suggesting that higher autonomous environmental motivation (i.e., acting out of choice and pleasure) is associated with the frequency of environmental behaviours such as recycling, paper reuse, and energy conservation. We also compared students' level of autonomous environmental motivation with their level of autonomous academic motivation. We then examined age effects on autonomous environmental motivation and compared them to age effects on autonomous academic motivation. A total of 200 high school students grouped into 5 age cohorts filled out a questionnaire. Results showed that (1) adolescents' autonomous environmental motivation was associated with more frequent environmental behaviours, (2) autonomous motivation was higher in the environmental than the school domain, and (3) autonomous environmental motivation was higher in older than younger students, whereas autonomous motivation toward school was equivalent across age groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Standing Tall in the Estuary

Accompanied by the guest-editors of this issue, Natasha Nicholson and Pamela Charlick take an exhilarating ride beyond the Thames Estuary, off the coast of Herne Bay, on Bayblast, the rigid hull inflatable boat (RHIB) - a trip that takes in the impressive Kentish Flats wind farm, under construction, and the Maunsell Forts. With substantial-scale projects already nestled in the estuary, new possibilities for architectural interpretation can be thrown up for the Thames Gateway flood plain. However, what potential contribution might the wind farm also make to the area in terms of power generation?