Human-computer interaction in ubiquitous computing environments

Purpose – The purpose of this paper is to explore characteristics of human-computer interaction when the human body and its movements become input for interaction and interface control in pervasive computing settings.

Design/methodology/approach – The paper quantifies the performance of human movement based on Fitt's Law and discusses some of the human factors and technical considerations that arise in trying to use human body movements as an input medium.

Findings – The paper finds that new interaction technologies utilising human movements may provide more flexible, naturalistic interfaces and support the ubiquitous or pervasive computing paradigm.

Practical implications – In pervasive computing environments the challenge is to create intuitive and user-friendly interfaces. Application domains that may utilize human body movements as input are surveyed here and the paper addresses issues such as culture, privacy, security and ethics raised by movement of a user's body-based interaction styles.

Originality/value – The paper describes the utilization of human body movements as input for interaction and interface control in pervasive computing settings.

An Intelligent Human-Computer Interaction System for Decision Support

This paper proposes a novel architecture for
developing decision support systems. Unlike conventional decision support systems, the proposed architecture endeavors to reveal the decision-making process such that humans' subjectivity can be
incorporated into a computerized system and, at the same time, to
preserve the capability of the computerized system in processing information objectively. A number of techniques used in developing the decision support system are elaborated to make the decisionmarking
process transparent. These include procedures for high dimensional data visualization, pattern classification, prediction, and evolutionary computational search. An artificial data set is first
employed to compare the proposed approach with other methods. A simulated handwritten data set and a real data set on liver disease diagnosis are then employed to evaluate the efficacy of the proposed
approach. The results are analyzed and discussed. The potentials of the proposed architecture as a useful decision support system are demonstrated.

A new perspective on competency management: Implemented through effective human-computer interaction

Making an informed decision on whether an individual is suited to undertake an educational course or industry training programme can be very frustrating. When dealing with young adults at different cognitive skill levels, it is important to be able to identify and distinguish between their knowledge/competency levels, mostly on the basis of the evidence gathered from test-items. The current absence of appropriate measurement tools to determine skill/competency/knowledge levels remains a practical issue. The main aim of this paper is to discuss the management of this important differentiation in cognitive skill performance. One of the dilemmas surrounding this type of competency evaluation is the time it takes to test an individual. Insisting for instance, that a novice undergoes a long and arduous test, including many difficult testing items, results in lowered self-esteem, reduced motivation for learning something new, may induce stress related disorders. Similarly, expecting a more competent individual to undergo numerous simple test-items can generate the same negative result. A Competency Management System (CMS) is presented to initiate effective human-computer interaction (HCI) for cognitive skills assessment. © 2009 Springer-Verlag US.

Evaluation of numerical procedures to determine seismic response of structures under influence of soil-structure interaction

In this study, the accuracy and reliability of fully nonlinear method against equivalent linear method for dynamic analysis of soil-structure interaction is investigated comparing the predicted results of both numerical procedures with the results of experimental shaking table tests. An enhanced numerical soil-structure model has been developed which treats the behaviour of the soil and the structure with equal rigour. The soil-structural model comprises a 15 storey structural model resting on a soft soil inside a laminar soil container. The structural model was analysed under three different conditions: (i) fixed base model performing conventional time history dynamic analysis, (ii) flexible base model (considering full soil-structure interaction) conducting equivalent linear dynamic analysis, and (iii) flexible base model performing fully nonlinear dynamic analysis. The results of the above mentioned three cases in terms of lateral storey deflections and inter-storey drifts are determined and compared with the experimental results of shaking table tests. Comparing the experimental results with the numerical analysis predictions, it is noted that equivalent linear method of dynamic analysis underestimates the inelastic seismic response of mid-rise moment resisting building frames resting on soft soils in comparison to the fully nonlinear dynamic analysis method. Thus, inelastic design procedure, using equivalent linear method, cannot adequately guarantee the structural safety for mid-rise building frames resting on soft soils. However, results obtained from the fully nonlinear method of analysis fit the experimental results reasonably well. Therefore, this method is recommended to be used by practicing engineers.

Fingertips detection for human interaction system

Fingertips of human hand play an important role in hand-based interaction with computers. Identification of fingertips' positions in hand images is vital for developing a human computer interaction system. This paper proposes a novel method for detecting fingertips of a hand image analyzing the concept of the geometrical structural information of fingers. The research is divided into three parts: First, hand image is segmented for detecting hand, Second, invariant features (curvature zero-crossing points) are extracted from the boundary of the hand, Third, fingertips are detected. Experimental results show that the proposed approach is promising.

Feature nodes : an interaction construct for sharing initiative in design exploration

Exploration with formal design systems comprises an iterative process of specifying problems, finding plausible and alternative solutions, judging the validity of solutions relative to problems and reformulating problems and solutions. Recent advances in formal generative design have developed the mathematics and algorithms to describe and perform conceptual design tasks. However, design remains a human enterprise: formalisms are part of a larger equation comprising human computer interaction. To support the user in designing with formal systems, shared representations that interleave initiative of the designer and the design formalism are necessary. The problem of devising representational structures in which initiative is sometimes taken by the designer and sometimes by a computer in working on a shared design task is reported in this paper. To address this problem, the requirements, representation and
implementation of a shared interaction construct, the feature node, is
described. The feature node facilitates the sharing of initiative in formulating and reformulating problems, generating solutions, making
choices and navigating the history of exploration.

Investigation of the effects of microcomputers on the work of professional accountants

Information technology research over the past two decades suggests that the installation and use of computers fundamentally affects the structure and function of organisations and, m particular, the workers in these organizations. Following the release of the IBM Personal Computer in 1982, microcomputers have become an integral part of most work environments. The accounting services industry, in particular, has felt the impact of this ‘microcomputer revolution’. In Big Six accounting firms, there is almost one microcomputer for each professional accountant employed, Notwithstanding this, little research has been done on the effect of microcomputers on the work outcomes of professional accountants working in these firms. This study addresses this issue. It assesses, in an organisational setting, how accountant’ perceptions of ease of use and usefulness of microcomputers act on their computer anxieties, microcomputer attitudes and use to affect their job satisfaction and job performance. The research also examines how different types of human-computer interfaces affect the relationships between accountants' beliefs about microcomputer utility and ease of use, computer anxiety, microcomputer attitudes and microcomputer use. To attain this research objective, a conceptual model was first developed, The model indicates that work outcomes (job satisfaction and job performance) of professional accountants using microcomputers are influenced by users' perceptions of ease of use and usefulness of microcomputers via paths through (a) the level of computer anxiety experienced by users, (b) the general attitude of users toward using microcomputers, and (c) the extent to which microcomputers are used by individuals. Empirically testable propositions were derived from the model to test the postulated relationships between these constructs. The study also tested whether or not users of different human-computer interfaces reacted differently to the perceptions and anxieties they hold about microcomputers and their use in the workplace. It was argued that users of graphical interfaces, because of the characteristics of those interfaces, react differently to their perceptions and anxieties about microcomputers compared with users of command-line (or textual-based) interfaces. A passive-observational study in a field setting was used to test the model and the research propositions. Data was collected from 164 professional accountants working in a Big Six accounting firm in a metropolitan city in Australia. Structural equation modelling techniques were used to test the, hypothesised causal relationships between the components comprising the general research model. Path analysis and ordinary least squares regression was used to estimate the parameters of the model and analyse the data obtained. Multisample analysis (or stacked model analysis) using EQS was used to test the fit of the model to the data of the different human-computer interface groups and to estimate the parameters for the paths in those different groups. The results show that the research model is a good description of the data. The job satisfaction of professional accountants is directly affected by their attitude toward using microcomputers and by microcomputer use itself. However, job performance appears to be only directly affected by microcomputer attitudes. Microcomputer use does not directly affect job performance. Along with perceived ease of use and perceived usefulness, computer anxiety is shown to be an important determinant of attitudes toward using microcomputers - higher levels of computer anxiety negatively affect attitudes toward using microcomputers. Conversely, higher levels of perceived ease of use and perceived usefulness heighten individuals' positive attitudes toward using microcomputers. Perceived ease of use and perceived usefulness also indirectly affect microcomputer attitudes through their effect on computer anxiety. The results show that higher levels of perceived ease of use and perceived usefulness result in lower levels of computer anxiety. A surprising result from the study is that while perceived ease of use is shown to directly affect the level of microcomputer usage, perceived usefulness and attitude toward using microcomputers does not. The results of the multisample analysis confirm that the research model fits the stacked model and that the stacked model is a significantly better fit if specific parameters are allowed to vary between the two human-computer interface user groups. In general, these results confirm that an interaction exists between the type of human-computer interface (the variable providing the grouping) and the other variables in the model The results show a clear difference between the two groups in the way in which perceived ease of use and perceived usefulness affect microcomputer attitude. In the case of users of command-line interfaces, these variables appear to affect microcomputer attitude via an intervening variable, computer anxiety, whereas in the graphical interface user group the effect occurs directly. Related to this, the results show that perceived ease of use and perceived usefulness have a significant direct effect on computer anxiety in command-line interface users, but no effect at all for graphical interface users. Of the two exogenous variables only perceived ease of use, and that in the case of the command-line interface users, has a direct significant effect on extent of use of microcomputers. In summary, the research has contributed to the development of a theory of individual adjustment to information technology in the workplace. It identifies certain perceptions, anxieties and attitudes about microcomputers and shows how they may affect work outcomes such as job satisfaction and job performance. It also shows that microcomputer-interface types have a differential effect on some of the hypothesised relationships represented in the general model. Future replication studies could sample a broader cross-section of the microcomputer user community. Finally, the results should help Big Six accounting firms to maximise the benefits of microcomputer use by making them aware of how working with microcomputers affects job satisfaction and job performance.

Design, development, and evaluation of a pinch-grasp haptic interface

Interaction with virtual or teleoperated environments requires contact with objects on a multipoint level. We describe the design of a pinch--grasp hand interface device for use as a grasping mechanism to complement haptic interfaces. To preserve a suitable level of transparency for human--computer interaction, this novel interface is designed for high-resolution contact forces, while centered around a lightweight structure. This functionality renders the device scalable and adaptable to a wide range of haptic interface structures and force level requirements. We present an optimal configuration for a pinch--grasp interface, which produces bidirectional forces to an operator's fingers and a rotational force to the wrist through a cable drive system. The device is characterized for use on a commercial haptic interface through demonstration of sustained peak performance and also workspace utilization. The dynamic performance of the pinch--grasp interface is experimentally determined, and the frequency response is identified to illustrate its contact force resolution.

UGI: a multi-dimensional ultrasonic-based interaction approach

We are currently witnessing an era where interaction with computers is no longer limited to conventional methods (i.e. keyboard and mouse). Human Computer Interaction (HCI) as a progressive field of research, has opened up alternatives to the traditional interaction techniques. Embedded Infrared (IR) sensors, Accelerometers and RGBD cameras have become common inputs for devices to recognize gestures and body movements. These sensors are vision based and as a result the devices that incorporate them will be reliant on presence of light. Ultrasonic sensors on the other hand do not suffer this limitation as they utilize properties of sound waves. These sensors however, have been mainly used for distance detection and not with HCI devices. This paper presents our approach in developing a multi-dimensional interaction input method and tool Ultrasonic Gesture-based Interaction (UGI) that utilizes ultrasonic sensors. We demonstrate how these sensors can detect object movements and recognize gestures. We present our approach in building the device and demonstrate sample interactions with it. We have also conducted a user study to evaluate our tool and its distance and micro gesture detection accuracy. This paper reports these results and outlines our future work in the area.

Graphical authentication : an architectural design specification

Graphical authentication is proposed as an alternative to password, smartcard, and biometric authentication as it uses the innate ability of humans to recognise visual stimuli. Despite passionate debate surrounding their privacy and invasiveness issues, smartcards and biometrics require an excessive amount of extra hardware for widespread deployment. Conversely graphical authentication extends existing infrastructure as it builds largely on the foundations of passwords with one important difference: it takes humans into account as they are better at recognising visual stimuli than recalling text-based passwords. This paper follows a preceding proof of concept paper and essentially outlines the architectural and technical design for a graphical authentication solution.

Graphical authentication: justifications and objectives

Password authentication has failed to address the compounding business requirement for increased security. Biometric authentication is beginning to address the need for tighter security, but it costs several orders of magnitude more than basic password implementations. Biometric authentication also possesses several shortcomings that inhibit its widespread adoption. In this paper we describe the trends in the literature before presenting the justifications and objectives for graphical authentication: a viable alternative to both biometrics and passwords. We also intend the paper to serve as a
prelude to forthcoming implementation and validation research.

Learning from facial aging patterns for automatic age estimation

Age Specific Human-Computer Interaction (ASHCI) has vast potential applications in daily life. However, automatic age estimation technique is still underdeveloped. One of the main reasons is that the aging effects on human faces present several unique characteristics which make age estimation a challenging task that requires non-standard classification approaches. According to the speciality of the facial aging effects, this paper proposes the AGES (AGing pattErn Sub-space) method for automatic age estimation. The basic idea is to model the aging pattern, which is defined as a sequence of personal aging face images, by learning a representative subspace. The proper aging pattern for an unseen face image is then determined by the projection in the subspace that can best reconstruct the face image, while the position of the face image in that aging pattern will indicate its age. The AGES method has shown encouraging performance in the comparative experiments either as an age estimator or as an age range estimator.

Stability of television viewing and electronic game/computer use in a prospective cohort study of Australian children: relationship with body mass index

Background
While much cross-sectional data is available, there have been few longitudinal investigations of patterns of electronic media use in children. Further, the possibility of a bi-directional relationship between electronic media use and body mass index in children has not been considered. This study aimed to describe longitudinal patterns of television viewing and electronic game/computer use, and investigate relationships with body mass index (BMI).
Methods
This prospective cohort study was conducted in elementary schools in Victoria, Australia. 1278 children aged 5–10 years at baseline and 8–13 years at follow-up had their BMI calculated, from measured height and weight, and transformed to z-scores based on US 2000 growth data. Weight status (non-overweight, overweight and obese) was based on international BMI cut-off points. Weekly television viewing and electronic game/computer use were reported by parents, these were summed to generate total weekly screen time. Children were classified as meeting electronic media use guidelines if their total screen time was ≤14 hrs/wk.
Results
Electronic media use increased over the course of the study; 40% met guidelines at baseline but only 18% three years later. Television viewing and electronic game/computer use tracked moderately and total screen time was positively associated with adiposity cross-sectionally. While weaker relationships with adiposity were observed longitudinally, baseline z-BMI and weight status were positively associated with follow-up screen time and baseline screen time was positively associated with z-BMI and weight status at follow-up. Children who did not meet guidelines at baseline had significantly higher z-BMI and were more likely to be classified as overweight/obese at follow-up.

Conclusion
Electronic media use in Australian elementary school children is high, increases with age and tracks over time. There appears to be a bi-directional association suggesting that interventions targeting reductions in either screen time or adiposity may have a positive effect on both screen time and adiposity.

Interpreting Fanger's comfort equation within the adaptive paradigm

This paper reviews the evolution of Fanger's heat balance equation in regard of adaptive opportunities. Heat balance and adaptive response are integrated into one model as two fundamental aspects of human-environment interaction that define thermal comfort perception, rather than being seen as two concepts of alternative comfort paradigms. The paper suggests to extent Fanger's model with a heat storage term in order to account for comfort perception under transient thermal conditions, and to review Fanger's modelling assumptions in order to allow for a greater variety of adaptive response options. In the presented model heat exchange is modulated through adaptation of physiological, environmental and behavioural parameters in the human-environment system defined through Fanger's heat exchange equations. A computational prototype is implemented to determine 'comfortable' values and ranges of the six comfort dimensions alternatively to Fanger's comfort indices. Thereby values of for example 'comfortable' clothing and metabolic rate are results rather than necessary input parameters, which are difficult to determine. This approach allows generating design advice for physical, organisational and social environments based on heat balance calculation in the six-dimensional opportunity space defined through Fanger's comfort equation. A starting point for the development of a dynamic adaptive comfort model is set.