Zugl.: Berlin, Humboldt-Univ., Diss., 2008

No description available.

Children between the ages of 4 - 16 years were tested for a sense of direction using the 'chair experiment'. Results revealed that a sense of direction was present in older children. However. the relationship between the development of a sense of direction and age appeared more complex than originally thought. Children under 11 years of age were unable to judge direction significantly in the chair experiment. It was suggested that this inability could be related to anatomical andlor perceptual constraints. Sex differences in ability were analysed. Although both males and females could significantly judge direction, female orientation was significantlY better than that exhibited by males. Analysis of the patterns of performance during the test revealed that male success was apparently due to an ability to follow the turning of the chair. with only the first estimate exhibiting significant ability. Females. although they probably followed the turning of the chair initially, showed a second peak of significant ability in the latter estimates. Whilst wearing a magnet. this second peak was not observed. Magnetic manipulations carried out on females aged between 11 - 18 years revealed that their ability to judge direction was based on an ability to use the earth's magnetic field to judge direction. However. this relationship was not straightforward. Both the polarity of the magnet and the bed orientation of the subject had an affect on ability to judge direction. Bus experiments were also used to test for a sense of direction. Subjects were aged between 16 - 20 years. Half the subjects were blindfolded and half were sighted. Results revealed that feBBles, whether blindfolded or sighted, relied on the earth's magnetic field when judging direction and exhibited disruption of ability whilst wearing a magnet. Kales apparently required sight and an unaltered magnetic field to judge direction. Thus, if sighted and wearing a magnet, or if blindfolded and in an unaltered magnetic field, males were unable to judge direction. Although male ability in the chair experiment did not seem to be based on an ability to use the earth's magnetic field to judge direction, the bus experiments suggested that magnetism was involved in their ability and this required further investigation.

Performance and power of sense amplifiers have big implications on the speed of caches used in microprocessors as well as power consumption of IPs in low power system on chips. The speed of voltage sense amplifiers are limited by the differential voltage development time on high capacitance SRAM bit-lines. The dynamic power increases with the differential voltage that needs to be developed on the bit-lines. This report explores multiple sense amplifier techniques - in addition to the conventional voltage sense amplifier, it analyzes current sense amplifier, charge transfer sense amplifier as wells as current latched sense amplifier and compares them in speed, area and power consumption to the voltage sense amplifier. A current sense amplifier operates by sensing the bit cell current directly and shows power and area advantages. A charge transfer sense amplifier makes use of charge redistribution between the high capacitance bit-lines and low capacitance sense amplifier output nodes to provide power benefits. This report also explores the design of a six transistor SRAM bit cell. All circuits are designed and simulated on a 45nm CMOS process. / text

published_or_final_version / Philosophy / Master / Master of Philosophy

No description available.

The polar landscapes have, for a long time, held the imaginations of people around the world. These extreme and remote environments have shaped the hearts and minds not only of people who have lived there, but also those who have only heard stories and seen pictures of these far off lands of ice and sky and snow. This dissertation examines the sense of place developed by New Zealanders towards Antarctica, across a spectrum of experiences with the continent, from seasonal workers and scientists, to people who have only ever seen it in books or advertisements. Taking a mainly phenomenological approach, the main objective of the research is to generate a theoretical base on what sense of place is made with and how it is created in extreme and remote environments like Antarctica. After examining 30 questionnaires and 54 interviews, the data indicate that there is no one New Zealand sense of Antarctica; rather, they are as manifold and complex as the individuals consulted. Regardless of the many differences across the various groups, a common thread was found of Antarctica as a place of hope. A hope based on scientific discovery and collaboration, on resource potential and conserving wild spaces. Findings also helped to develop a theoretical model, which builds on the existing works of Tuan (1977), Sack (1997), and Gustafson (2001). Three important theoretical aspects were identified through the analysis, including the ideas of personal connection, narrative emplotement, and one’s sense of identity. The theory contributes to the ongoing discussion of how people encounter and make sense of extreme and remote environments. Both the findings themselves and the theory behind them suggest that policy makers, communicators, and tourism operators be aware of their target audience, their cultural values and changing symbolism, in order to better communicate their intended message.

The incorporation of the sense of touch into virtual reality is an exciting development. However, research into this topic is in its infancy. This experimental programme investigated both the perception of virtual object attributes by touch and the parameters that influence touch perception in virtual reality with a force feedback device called the PHANTOM (TM) (www.sensable.com). The thesis had three main foci. Firstly, it aimed to provide an experimental account of the perception of the attributes of roughness, size and angular extent by touch via the PHANTOM (TM) device. Secondly, it aimed to contribute to the resolution of a number of other issues important in developing an understanding of the parameters that exert an influence on touch in virtual reality. Finally, it aimed to compare touch in virtual reality between sighted and blind individuals. This thesis comprises six experiments. Experiment one examined the perception of the roughness of virtual textures with the PHANTOM (TM) device. The effect of the following factors was addressed: the groove width of the textured stimuli; the endpoint used (stylus or thimble) with the PHANTOM (TM); the specific device used (PHANTOM (TM) vs. IE3000) and the visual status (sighted or blind) of the participants. Experiment two extended the findings of experiment one by addressing the impact of an exploration related factor on perceived roughness, that of the contact force an individual applies to a virtual texture. The interaction between this variable and the factors of groove width, endpoint, and visual status was also addressed. Experiment three examined the perception of the size and angular extent of virtual 3-D objects via the PHANTOM (TM). With respect to the perception of virtual object size, the effect of the following factors was addressed: the size of the object (2.7,3.6,4.5 cm); the type of virtual object (cube vs. sphere); the mode in which the virtual objects were presented; the endpoint used with the PHANTOM (TM) and the visual status of the participants. With respect to the perception of virtual object angular extent, the effect of the following factors was addressed: the angular extent of the object (18,41 and 64°); the endpoint used with the PHANTOM (TM) and the visual status of the participants. Experiment four examined the perception of the size and angular extent of real counterparts to the virtual 3-D objects used in experiment three. Experiment four manipulated the conditions under which participants examined the real objects. Participants were asked to give judgements of object size and angular extent via the deactivated PHANTOM (TM), a stylus probe, a bare index finger and without any constraints on their exploration. In addition to the above exploration type factor, experiment four examined the impact of the same factors on perceived size and angular extent in the real world as had been examined in virtual reality. Experiments five and six examined the consistency of the perception of linear extent across the 3-D axes in virtual space. Both experiments manipulated the following factors: Line extent (2.7,3.6 and 4.5cm); line dimension (x, y and z axis); movement type (active vs. passive movement) and visual status. Experiment six additionally manipulated the direction of movement within the 3-D axes. Perceived roughness was assessed by the method of magnitude estimation. The perceived size and angular extent of the various virtual stimuli and their real counterparts was assessed by the method of magnitude reproduction. This technique was also used to assess perceived extent across the 3-D axes. Touch perception via the PHANTOM (TM) was found to be broadly similar for sighted and blind participants. Touch perception in virtual reality was also found to be broadly similar between two different 3-D force feedback devices (the PHANTOM (TM) and the IE3000). However, the endpoint used with the PHANTOM (TM) device was found to exert significant, but inconsistent effects on the perception of virtual object attributes. Touch perception with the PHANTOM (TM) across the 3-D axes was found to be anisotropic in a similar way to the real world, with the illusion that radial extents were perceived as longer than equivalent tangential extents. The perception of 3-D object size and angular extent was found to be comparable between virtual reality and the real world, particularly under conditions where the participants' exploration of the real objects was constrained to a single point of contact. An intriguing touch illusion, whereby virtual objects explored from the inside were perceived to be larger than the same objects perceived from the outside was found to occur widely in virtual reality, in addition to the real world. This thesis contributes to knowledge of touch perception in virtual reality. The findings have interesting implications for theories of touch perception, both virtual and real.

Thesis (PH.D.)--University of Illinois, 1919. / Thesis note on verso of t.-p. "Contributions from the Zoological laboratory of the University of Illinois under the direction of Henry B. Ward, no. 171." Bibliography: p. 68-70. Also available in print.

Thesis (Ph. D.)--University of Illinois, 1919. / Thesis note on verso of t.p. "Contributions from the Zoological laboratory of the University of Illinois under the direction of Henry B. Ward, no. 171." Bibliography: p. 68-70.