How the visual environment shapes attention: The role of context in attention guidance

In our environment, visual stimuli typically appear within the context of other stimuli, which are usually not arranged randomly but follow regularities. These regularities can be very useful for the visual system to overcome the problem of limited encoding capacity by guiding attention to stimuli which are relevant for behavior. There is growing evidence that observers use repeated contexts for guiding attention in visual search, and there is evidence that observers adapt to dynamical changes in their visual environment. However, contexts in our natural environment often come with features predicting reward, and little is known about the influence of such reward-predicting contexts on attention guidance. In addition, it is unclear how observers adapt their behavior to context features that are not relevant for the task, and little is known about individual differences in the effects of contexts. These research gaps are addressed in the present dissertation. In five studies, the present dissertation investigates how different types of contextual regularities are integrated into behavior and how these regularities guide visual attention. Study I showed that observers use knowledge they have acquired in former encounters with similar scenes to predict the most promising item to attend to in an upcoming scene. In a visual search task in the laboratory, participants responded faster in visual contexts that repeated compared to contexts that were novel. In addition, they also moved their eyes more efficiently to the target when they encountered repeated contexts. These results suggest that participants use repeated visual contexts to learn to predict the target location. Study I also revealed that visual contexts are especially used for specifying promising items when they predict a high reward. Context features predicting a high reward boosted the performance advantages observed with repeated contexts. This result suggests that the prediction of reward facilitates the generation of expectations about potential target locations. Study II demonstrated that expectations about potential target locations were quite persistent, since performance benefits were observed even after many encounters with repeated contexts. Further experiments showed that participants could use even a very limited part of the visual contexts to learn to predict the target location (Study III) and that observers used also contexts that changed dynamically for specifying promising items to attend to (Study IV). These results suggest that observers use regularities in the visual context to generate expectations about promising items in their visual environment. Finally, the last study of this dissertation (Study V) investigated how contexts of social perception are used for specifying relevant visual information. Results showed that observers differ in how they use contexts for specifying relevant visual information and suggested that an observer’s personality might be one factor explaining these differences. In sum, the five studies of the present dissertation demonstrate that the visual system is remarkably sensitive to regularities in the visual context. It is quite efficient in extracting repeated contexts to guide attention to relevant locations when contexts are encountered again (Studies I and II), and it only needs a very limited amount of repeating contextual information to take advantage from the contexts (Study III). It also considers rewards that are signaled by features of the contexts to prioritize processing of high reward contexts. The visual system further adapts to dynamical changes in the contexts (Study IV) and uses contexts of social perception for prioritizing information, dependent on the observer’s personality (Study V). The present dissertation thus highlights that the visual context is crucial for guiding our attention in numerous situations that we encounter every day. Fortunately, we can take advantage of the visual context, which allows our visual system to cope with its limited processing capacity

Knowledge Search within a Company-WIKI

The usage of Wikis for the purpose of knowledge management within a business company is only of value if the stored information can be found easily. The fundamental characteristic of a Wiki, its easy and informal usage, results in large amounts of steadily changing, unstructured documents. The widely used full-text search often provides search results of insufficient accuracy. In this paper, we will present an approach likely to improve search quality, through the use of Semantic Web, Text Mining, and Case Based Reasoning (CBR) technologies. Search results are more precise and complete because, in contrast to full-text search, the proposed knowledge-based search operates on the semantic layer

Motives and Incentives for Data Sharing in Industrial Data Ecosystems: An Explorative Single Case Study

The increasing connectivity of the business world leads to economic value being created less and less by one company alone, but rather through the exchange and combination of data by various actors in so-called data ecosystems. However, many companies are not yet willing to participate in data ecosystems because they do not see the added value of their participation. This is partly because the motives of data providers do not match the incentives offered to share their data. So far, there are only very few studies that deal with this issue in detail. Therefore, we close this research gap by adopting a conceptual model to the issue of motives and incentives for data sharing and applying it to the industrial data ecosystem Catena-X in a single case study. Through the case study analysis, we can identify seven different motives and eight incentives for data sharing

Wear Behavior of Metal Bonded Grinding Tools When Grinding Ti-6Al-4V in an Oxygen-Free Atmosphere

In the current study, the wear behavior of bronze-bonded grinding tools when grinding the titanium alloy Ti-6Al-4V was explored. In this process, oxidation plays a key role since both the bronze bond and the titanium workpiece chemically react with oxygen. The oxidation effect is intensified further due to increased temperatures during grinding and can cause tribo-oxidation. This wear effect can be reduced or even eliminated by grinding in an extreme high-vacuum (XHV) adequate atmosphere. This atmosphere is nearly oxygen-free and is generated using a silane-doped argon gas that chemically reacts with oxygen. This reaction is able to decrease the oxygen partial pressure (pO2 ≤ 10−12 mbar) down to an XHV-adequate atmosphere. The aim of this paper is to investigate the influence of oxygen in the atmosphere on the application and wear behavior during grinding and to demonstrate the potential of this novel approach. The results presented show that during grinding with cBN, the process forces are significantly influenced by the atmosphere. Depending on the process parameters, a reduction of up to 93% is thus possible. This force reduction correlates with radial tool wear. When grinding under oxygen-free conditions, it can be reduced by up to 64%

WEB SURVEY GAMIFICATION – INCREASING DATA QUALITY IN WEB SURVEYS BY USING GAME DESIGN ELEMENTS

Researchers and survey designers face the challenge of low data quality as web surveys are often not compelling. Thus, participants’ engagement declines while completing a survey resulting in participants tend to apply satisficing behavior (e.g., speeding, straight-lining) in order to complete the questionnaire or even break-off the completion of the questionnaire. Due to satisficing behavior, researchers are faced with the challenge of low data quality. Addressing this challenge, survey gamification promises to make web survey participation enjoyable, which might also engage participants to complete questionnaires by providing high-quality data. However, the research on the effects of gamifying web surveys (in particular on behavioral outcomes) is still inconclusive. Addressing this short-coming, we propose to examine the effects of two common game design elements – badges and a meaningful story – in an experimental study. Based on the theoretical background of gamification and the theory of cognitive absorption, we derive hypotheses and outline in detail our experimental design in this research-in-progress paper. Our proposed research study will contribute to research and practice by addressing an important challenge when conducting online surveys: the motivation to process surveys accurately

Influence of an Oxygen-Free Atmosphere on Process Forces and Workpiece Quality during the Surface Grinding of Ti-6Al-4V

Most manufacturing processes, such as grinding, are usually conducted in a standard air atmosphere. The oxygen within this atmosphere leads to oxidation effects on tools and workpieces when machining metal components. This is primarily a factor in the processing of titanium due to its high affinity for oxygen. The oxidation of the surface increases tool wear and reduces surface quality. Hence, this paper investigates the influence of the atmosphere on process forces and workpiece quality when grinding titanium (Ti6Al4V) with metal-bonded diamond grinding tools. To generate oxygen-free conditions in production processes, a novel approach allows an atmosphere with a very low oxygen partial pressure. Using a silane gas, which reacts with oxygen, the oxygen partial pressure, pO2, can be reduced below 10−12 mbar, equal to the oxygen partial pressure in an extremely high vacuum (XHV). The results show a significant influence of the atmosphere on the process forces. When grinding in XHV-adequate conditions, the grinding forces are reduced by 16% in the tangential direction and 50% in the normal direction on average, while the quality of the ground titanium surfaces is consistent (both atmospheres: Rz = 13–21 µm). Phase analysis via XRD revealed a distinct amount of titanium nitride (TiN) on the ground surfaces independently of the atmospheric conditions

Intimate partner violence is a barrier to antiretroviral therapy adherence among HIV - positive women: Evidence from government facilities in Kenya

Introduction: Intimate Partner Violence (IPV) is linked to low engagement with HIV management services and adverse clinical outcomes, including poor ART adherence. In sub-Saharan Africa, studies on pregnant/postpartum women and transactional sex workers have produced divergent evidence regarding IPV’s association with poor ART adherence. We investigate this association among a broad group of women. Methods: We sampled 408 HIV-positive women receiving free ART from different types of HIV clinics at government health facilities, assessing for IPV exposure by a current partner, ART adherence rate, and other factors that affect ART adherence (e.g. education, disclosure). ART adherence rates were measured using the Visual Analogue Scale (VAS); responses were dichotomised at a �95% cut-off. Multiple logistic regression models assessed the association between the independent variables and ART adherence. Results: The participants’ mean age was 38.6 (range: 18–69 years). The majority had ever attended school (94%, n = 382), were in monogamous marriages (70%, n = 282), and had disclosed status to partners (94%, n = 380). Overall, 60% (n = 242) reported optimal ART adherence (� 95%) in the previous 30 days. The prevalence of IPV by the current partner was 76% (CI95 = 72–80%). Experiencing physical IPV (AOR 0.57, CI95: 0.34–0.94, p = .028), sexual IPV (AOR 0.50, CI95: 0.31–0.82, p = .005), or controlling behaviour (AOR 0.56, CI95: 0.34– 0.94, p = .027) reduced the odds of achieving optimal adherence, while a higher education level and having an HIV-positive partner increased the odds. Conclusion: IPV is common and is associated with suboptimal ART adherence rates among a broad group of HIV-positive women. ART programs could consider incorporating basic IPV interventions into regular clinic services to identify, monitor and support exposed women, as they might be at risk of poor ART adherence. Still, there is need for more research on how IPV affects ART adherence

Wie können Lehrsituationen zu Lernsituationen werden? – Rekonstruktive Forschung am eigenen Fall als Ausgangspunkt für die Professionalisierung von Sportlehrkräften

Ukley N, Bergmann F. Wie können Lehrsituationen zu Lernsituationen werden? – Rekonstruktive Forschung am eigenen Fall als Ausgangspunkt für die Professionalisierung von Sportlehrkräften. Presented at the Lehr-Lern-Situationen als Ausgangspunkt sportpädagogischer Forschung. DGfE-Jahrestagung der Kommission Sportpädagogik, Hamburg

Influence of the atmosphere and temperature on the properties of the oxygen-affine bonding system titanium-diamond during sintering

Grinding tools can be manufactured from metal, vitrified, and resin bond materials. In combination with superabrasives like diamond grains, metal-bonded tools are used in a wide range of applications. The main advantages of metal over vitrified and resin bonds are high grain retention forces and high thermal conductivity. This paper investigates the influence of the atmosphere and manufacturing parameters such as sintering temperature on the properties of titanium-bonded grinding layers. Titanium is an active bond material, which can increase the retention of diamond grains in metal-bonded grinding layers. This can lead to higher bond stress and, consequently, decreased wear of grinding tools in use when compared to other commonly used bond materials like bronze. The reason for this is the adhesive bond between titanium and diamond due to the formation of carbides in the interface, whereas bronze can only form a mechanical cohesion with diamond grains. However, when using oxygen-affine metals such as titanium, oxidizing effects could limit the strength of the bond due to insufficient adhesion between Ti-powder particles and the prevention of carbide formation. The purpose of this paper is to show the influence of the sintering atmosphere and temperature on the properties of titanium-bonded diamond grinding layers using the mechanical and thermal characterization of specimens. A higher vacuum (Δpatm = − 75 mbar) reduces the oxidation of titanium particles during sintering, which leads to higher critical bond stress (+ 38% @ Ts = 900 °C) and higher thermal conductivity (+ 3.4% @Ts = 1000 °C, Ta = 25 °C). X-ray diffraction measurements could show the formation of carbides in the cross-section of specimens, which also has a positive effect on the critical bond stress due to an adhesive bond between titanium and diamond