Haptic augmentation of the cursor: transforming virtual actions into physical actions

This thesis demonstrates, through the exploration of two very different examples, the general claim that haptic feedback relating to a user's representation in a computer system (typically a cursor) can lead to increases in objective performance and subjective experience. Design guidelines covering each of these two topics are also presented, to ensure that the research described here can be readily adopted by other researchers, designers and system developers. The first topic to be investigated was desktop user interfaces. This thesis describes the design of a variety of different forms of haptic feedback for use with number of different Graphical User Interface (GUI) widgets, or widget groups. Two empirical evaluations of these designs are also described in some depth. The results of these studies indicate that although haptic feedback can provide improvements in objective performance, it can also reduce performance and increase subjective workload if inappropriately applied. From these results, and from the previous literature, detailed guidelines were drawn up covering the addition of haptic feedback to GUIs. The goal of these guidelines is to support the creation of performance-enhancing haptic feedback. The second topic examined was communication in interactive collaborative systems. The design of a suite of haptic communication is presented in detail, before two studies investigating different aspects of its use. The first study focuses on the subjective influence of the haptic communication as a whole, while the second is a more thorough look at one particular form of the feedback and includes objective measurements. The combined results of these studies indicate that haptic feedback has a valuable potential for increasing the quality of a user's subjective experience. Observations from these studies also reveal insights into the role of haptic feedback in communication. A set of guidelines summing up this research and the previous literature relevant to this topic are then presented. As research on this domain is in its infancy, the goal of these guidelines is to concisely present the main issues and potential benefits that respectively restrict and drive this work

Understanding goal setting behavior in the context of energy consumption reduction

Home energy use represents a significant proportion of total con sumption. A growing research area is considering how to help everyday users consume less. However, simply determining how to best reduce consumption remains a challenging task for many users. Based on goal setting theory, this paper presents two lab studies (based on the presentation of detailed scenarios and the solicitation of goal selections for the individuals depicted) in order to better understand how users make such decisions. It reveals a preference for goals that are perceived to be easy and specific, rather than those known to be effective (e.g. those that reduce energy consumption) or generic. Goal setting theory suggests that easy goals lead to low levels of commitment and motiva tion, suggesting such choices may be doubly ineffective. Ultimately, this paper contributes to a better understanding of users’ goal selections and argues this is a prerequisite to effectively supporting users in reducing resource consumption.info:eu-repo/semantics/publishedVersio

Keeping Secrets from Friends: Design Guidelines for Multiplexed Graphical Passwords

Background Entering passwords on mobile devices often takes place in public, situations in which input actions are exposed to the people around you and passwords can be compromised simply by sneaky glances over shoulders. However, the people who surround a user are typically not malicious attackers seeking to steal data, but rather friends and colleagues. This article characterizes such individuals as casual observers and describes the threats they pose to security and password integrity. Methods Based on an analysis of the literature and design space, we introduce a systematic framework for multiplexed authentication, a term we introduce to describe a class of systems that maintain security against the threats posed by casual observers through obsfuscated input. Building on this knowledge, we present a set of design dimensions and guidelines for multiplexed graphical passwords. Finally, we present ShaPIN, a multiplexed input prototype designed in light of these guidelines and that aims to protect users against casual observation. Results Evaluations of ShaPIN with a user study reveal it can be used rapidly, accurately and that it provides protection against in-person observation. ShaPIN also offers substantial performance imporvements over prior systems in its class, evidence that helps support and validate our design framework. Conclusion We believe that the framework of multiplexed authentication can inform and shape future work to ensure that passwords stay safe and secret in front of friends. By presenting design guidelines for multiplexed graphical passwords we also hope to raise awareness of the important issue of password security in the design community and to show how design research can innovate in this area to create more usable and effective password systems.clos

Loss of APC induces polyploidy as a result of a combination of defects in mitosis and apoptosis

Mutations in the adenomatous polyposis coli (APC) tumor suppressor gene initiate a majority of colorectal cancers. Acquisition of chromosomal instability is an early event in these tumors. We provide evidence that the loss of APC leads to a partial loss of interkinetochore tension at metaphase and alters mitotic progression. Furthermore, we show that inhibition of APC in U2OS cells compromises the mitotic spindle checkpoint. This is accompanied by a decrease in the association of the checkpoint proteins Bub1 and BubR1 with kinetochores. Additionally, APC depletion reduced apoptosis. As expected from this combination of defects, tetraploidy and polyploidy are consequences of APC inhibition in vitro and in vivo. The removal of APC produced the same defects in HCT116 cells that have constitutively active β-catenin. These data show that the loss of APC immediately induces chromosomal instability as a result of a combination of mitotic and apoptotic defects. We suggest that these defects amplify each other to increase the incidence of tetra- and polyploidy in early stages of tumorigenesis

Obfuscating authentication through haptics, sound and light

Abstract Sensitive digital content associated with or owned by individuals now pervades everyday life. Mediating accessing to it in ways that are usable and secure is an ongoing challenge. This paper briefly discusses a series of five PIN entry and transmission systems that address observation attacks in public spaces via shoulder surfing or camera recording. They do this through the use of novel modalities including audio cues, haptic cues and modulated visible light. Each prototype is introduced and motivated, and its strengths and weaknesses are considered. The paper closes with a general discussion of the relevance of this work and the upcoming issues it faces

Experimental evidence that evolutionary relatedness does not affect the ecological mechanisms of coexistence in freshwater green algae

The coexistence of competing species depends on the balance between their fitness differences, which determine their competitive inequalities, and their niche differences, which stabilise their competitive interactions. Darwin proposed that evolution causes species' niches to diverge, but the influence of evolution on relative fitness differences, and the importance of both niche and fitness differences in determining coexistence have not yet been studied together. We tested whether the phylogenetic distances between species of green freshwater algae determined their abilities to coexist in a microcosm experiment. We found that niche differences were more important in explaining coexistence than relative fitness differences, and that phylogenetic distance had no effect on either coexistence or on the sizes of niche and fitness differences. These results were corroborated by an analysis of the frequency of the co‐occurrence of 325 pairwise combinations of algal taxa in > 1100 lakes across North America. Phylogenetic distance may not explain the coexistence of freshwater green algae.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100307/1/ele12182.pd