In almost all collaborative tabletop tasks, groups require coordinated access to the shared objects on the table’s surface. The physical social norms of close-proximity interactions built up over years of interacting around other physical bodies cause people to avoid interfering with other people (e.g., avoiding grabbing the same object simultaneously). However, some digital tabletop situations require the use of indirect input (e.g., when using mice, and when supporting remote users). With indirect input, people are no longer physically embodied during their reaching gestures, so most systems provide digital embodiments – visual representations of each person – to provide feedback to both the person who is reaching and to the other group members. Tabletop arm embodiments have been shown to better support group interactions than simple visual designs, providing awareness of actions to the group. However, researchers and digital tabletop designers know little of how the design of digital arm embodiments affects the fundamental group tabletop interaction of reaching for objects. Therefore, in this thesis, we evaluate how people coordinate their interactions over digital tabletops when using different types of embodiments. Specifically, in a series of studies, we investigate how the visual design (what they look like) and interaction design (how they work) of digital arm embodiments affects a group’s coordinative behaviours in an open- ended parallel tabletop task. We evaluated visual factors of size, transparency, and realism (through pictures and videos of physical arms), as well as interaction factors of input and augmentations (feedback of interactions), in both a co-located and distributed environment. We found that the visual design had little effect on a group’s ability to coordinate access to shared tabletop items, that embodiment augmentations are useful to support group coordinative actions, and that there are large differences when the person is not physically co-present. Our results demonstrate an initial exploration into the design of digital arm embodiments, providing design guidelines for future researchers and designers to use when designing the next generation of shared digital spaces.

The purpose of this study is to test the hypothesis that centrally- planned economies are characterized by what is called a bias towards absorption of natural resource intensive products (NRP) which is said to affect in turn the commodity structure of their foreign trade. While the study includes a detailed analysis of foreign trade structures and the absorption of NRP by final consumers, it is the intermediate demand for NRP and its determinants which are emphasized. Following the suggestions in the literature that the technologies used by the centrally- planned and market-type economies are different, the role of technology in determining intermediate demand for NRP has been examined in detail. Bias is defined here in terms of inter-country differences and the present comparison involves a case-study of Czechoslovakia as a centrally-planned economy and Austria as a market-type economy based on an input-output model. The use of the input-output model in inter- national comparisons of production and use of commodities has been criticized on the following grounds: (1) The distinction between technology and substitution is ignored in the model. (2) International differences in relative prices are normally ignored or assumed away in empirical work. (3) The comparisons may be severely affected by imperfections of input-output tables. This study attempts to answer the above criticism in an original way. New methods of sensitivity analysis were designed to test for the existence of the 'triangular' and other 'fundamental' properties of the technological matrices. In addition, the assumption of temporal stability of input-output coefficients is relaxed and an attempt is made to distinguish between technology and substitution with the help of the RAS method. Further analysis of the impact of relative prices on input-output flows was derived from an analysis of indirect taxation. The main conclusion of this study is that Czechoslovakia had a considerable NRP import bias which was primarily due to the pro-NRP absorption bias of final consumers. However, it is unlikely that 'excessive' aggregate demand for imports originated in 'NRP-biased' technology. This empirical analysis provides strong evidence that the production processes with regard to the use of NRP were highly similar in both countries.

This study investigates if and how grammar instructions and exercises in Spanish textbooks have evolved during the last thirty years. More specifically it focuses on how the grammar is presented (explicit instruction) and on the nature of the exercises (input, production and interaction). The method for investigating these things is firstly an analysis of the explicit instruction, and secondly a quantitative study of the exercises. The number of textbooks analyzed in this study is four and only the chapters that focus on teaching the preterite are included in the analysis. The result shows a tendency towards direct explicit instruction and controlled production practice. However, it also shows some signs that newer perspectives are gaining importance in the textbooks analyzed.

Graduation date: 1980

This dissertation investigates deformable computer input device technologies to facilitate capturing complex physical-world gestures. By capturing the physical gestures and using appropriate haptics, it is possible to create virtual models using pinching and squeezing gestures similar to those used when sculpting clay. To date, most desktop modelling applications employ pointing devices that capture a single cursor location to manipulate a model with tedious sequential steps. One reason for this is developers have focused efforts on adopting applications to work with generic two-dimensional pointing devices, such as a mouse or digitising tablet. This is due to the difficulty of developing three-dimensional input technologies. In particular, deformable sensors capable of capturing natural sculpting techniques are undeveloped. / PhD Doctorate

Doctor of Philosophy (PhD) / The purpose of this research is to help understand the key relationships in an evolving economic structure that are driving resource use and greenhouse gas emissions in Australia. The approach involves looking at the factors and relationships that underpin economic growth in Australia. This research seeks to understand the changes in these factors by taking a historical perspective to the determinants of environmental impact through an investigation of structural changes over a period of 30 years. A detailed model is developed using the macro-economic tool of input-output analysis. This model makes it possible to investigate inter-relationships and intra-relationships between sectors of the environment, the economy and the population at disparate scales.

Zugl.: Freiburg im Breisgau, Univ., Diss., 2005/06

Zugl.: Freiburg i. Br., Univ., Diss., 2005/06

Thesis (M.E.E.)--University of Delaware, 2008. / Principal faculty advisor: John G. Elias, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

Thesis (M.S.)--Rochester Institute of Technology, 2008 / Typescript. Includes bibliographical references (leaves 48-57).