Georgios Christou | Cyprus International Institute of Management (original) (raw)

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Papers by Georgios Christou

Introducing semi-automatic teleoperation of an agricultural robotic system can enable improved pe... more Introducing semi-automatic teleoperation of an agricultural robotic system can enable improved performance, overcoming the complexity that current autonomous robots face due to the dynamic and unstructured agriculture environment. A teleoperated robot can both leverage the farmers’ knowledge and experience while keeping them safe and also help the robot manage the unpredictability of the environment in the field. In this paper we describe the construction of such a teleoperated agricultural robot sprayer that is controlled through a Reality-Based Interaction interface. Two different user interfaces for teleoperating a vineyard spraying robot were experimentally evaluated. In the first condition, participants were provided with a single view (one camera) for teleoperating the robot, whereas in the second condition they had additional views (multiple cameras) supporting peripheral vision and targeted spraying. Analysis of the collected data showed that users in the additional views co...

Applied Ergonomics, 2017

Teleoperation of an agricultural robotic system requires effective and efficient human-robot inte... more Teleoperation of an agricultural robotic system requires effective and efficient human-robot interaction. This paper investigates the usability of different interaction modes for agricultural robot teleoperation. Specifically, we examined the overall influence of two types of output devices (PC screen, head mounted display), two types of peripheral vision support mechanisms (single view, multiple views), and two types of control input devices (PC keyboard, PS3 gamepad) on observed and perceived usability of a teleoperated agricultural sprayer. A modular user interface for teleoperating an agricultural robot sprayer was constructed and field-tested. Evaluation included eight interaction modes: the different combinations of the 3 factors. Thirty representative participants used each interaction mode to navigate the robot along a vineyard and spray grape clusters based on a 2 × 2 × 2 repeated measures experimental design. Objective metrics of the effectiveness and efficiency of the human-robot collaboration were collected. Participants also completed questionnaires related to their user experience with the system in each interaction mode. Results show that the most important factor for human-robot interface usability is the number and placement of views. The type of robot control input device was also a significant factor in certain dependents, whereas the effect of the screen output type was only significant on the participants&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; perceived workload index. Specific recommendations for mobile field robot teleoperation to improve HRI awareness for the agricultural spraying task are presented.

This paper presents a predictive quantitative measure for the comparison of the performance of a ... more This paper presents a predictive quantitative measure for the comparison of the performance of a task, when that task is designed in different interaction styles. The paper presents an extension of Task Knowledge Structures (Johnson and Johnson, 1991a) and based on this extension it presents identifiability, which is the evaluative and predictive measure that is the main focus of the paper. The paper then presents an experiment, which provides evidence towards the validity of the measure and its intended usage.

Chi 09 Extended Abstracts on Human Factors in Computing Systems, 2009

Abstract This workshop aims to further the understanding of the challenges relating to the evalua... more Abstract This workshop aims to further the understanding of the challenges relating to the evaluation methods of usability and user experience that are specific to Reality-Based Interaction (RBI), and to identify effective practical responses to these challenges. The emergence of Post-WIMP interfaces has led to new ways of interacting with technologies. However, there are still no integrated ways of evaluating the usability and user experience of these interfaces. Developers and designers are left to discover their own metrics and ...

ABSTRACT This paper discusses the question of how game designers can keep their games fair when a... more ABSTRACT This paper discusses the question of how game designers can keep their games fair when adding collaborative content and rewards. The paper presents findings from World of Warcraft in-game chat transcripts and data gathered through an online survey that was placed online for approximately 9 months during 2010. From the chat transcripts, we find that players sometimes do abuse mechanisms for collaborative content, which displeases the other players involved. We also find that players believe that there needs to ...

The great variety of new (Post-WIMP) interaction styles make them difficult to evaluate and compa... more The great variety of new (Post-WIMP) interaction styles make them difficult to evaluate and compare. We propose a new evaluation method for them, Knowledge-Based Usability Evaluation (KBUE), that is based on similar ideas to those that drive cognitive architectures, such as ACT-R and Soar. We present KBUE as a way to formally specify the knowledge in the environment and in the user's head, and how this specification can be used to examine whether the aforementioned set of knowledge covers the required knowledge for the performance of a task in a user interface. We believe that by using this specification, it becomes easier to evaluate and compare Reality-Based interfaces.

ABSTRACT Three interdisciplinary projects were assigned to three groups of 4th year undergraduate... more ABSTRACT Three interdisciplinary projects were assigned to three groups of 4th year undergraduate students studying Computer Engineering and Computer Science. Each group was required to design, implement and test a new system in collaboration with at least one of the following Departments: Psychology, Physiotherapy and Arts. Students participating in these projects had the opportunity to exchange ideas with students from other disciplines to finalise their system requirements. This paper presents the findings of a research conducted regarding the promotion of interdisciplinary project practices in engineering in order to provide students with real life challenges. The results of our survey-based methodology depicted that the majority of the students appreciated the nature and the importance of the interdisciplinary projects stating that they helped them to further develop their academic and research skills as well as their interpersonal abilities. These projects encouraged the engineers to look into other fields and seek support from students from other disciplines just like in real life.

Computers in Human Behavior, 2015

International Journal of Human-Computer Studies, 2011

An input device should be natural and convenient for a user to transmit information to a computer... more An input device should be natural and convenient for a user to transmit information to a computer, and should be designed from an understanding of the task to be performed and the interrelationship between the task and the device from the perspective of the user. In order to investigate the potential of speech input as a reality based interaction device, this paper presents the findings of a study that investigated speech input in a VR application. Two independent user trials were combined within the same experimental design to evaluate the commands that ...

Abstract: This thesis presents Cognitive Description and Evaluation of Interaction (CoDeIn), a fr... more Abstract: This thesis presents Cognitive Description and Evaluation of Interaction (CoDeIn), a framework that allows one to describe, compare, and estimate completion times for tasks that are designed in a variety of interaction styles. Task time estimates based upon ...

This article presents the design aspects and development processes to transform a general-purpose... more This article presents the design aspects and development processes to transform a general-purpose mobile robotic platform into a semi-autonomous agricultural robot sprayer focusing on user interfaces for teleoperation. The hardware and the software modules that must be installed onto the system are described, with particular emphasis on human–robot interaction. Details of the technology are given focusing on the user interface aspects. Two laboratory experiments and two studies in the field to evaluate the usability of the user interface provide evidence for the increased usability of a prototype robotic system. Specifically, the study aimed to empirically evaluate the type of target selection input device mouse and digital pen outperformed Wiimote
in terms of usability. A field experiment evaluated the effect of three design factors:(a) type of screen output, (b) number of views, c) type of robot control input device. Results showed that participants were significantly more effective but less efficient when they had multiple views, than when they had a single view. PC keyboard was also found to significantly outperform PS3 gamepad in terms o finteraction efficiency and perceived usability. Heuristic evaluations of different user interfaces were also performed using research-based HRI heuristics. Finally, a study on participants’ overall user experience found that the system was evaluated positively on the User Experience Questionnaire scales.

STEM Education: Concepts, Methodologies, Tools, and Applications, 2015

Introducing semi-automatic teleoperation of an agricultural robotic system can enable improved pe... more Introducing semi-automatic teleoperation of an agricultural robotic system can enable improved performance, overcoming the complexity that current autonomous robots face due to the dynamic and unstructured agriculture environment. A teleoperated robot can both leverage the farmers' knowledge and experience while keeping them safe and also help the robot manage the unpredictability of the environment in the field. In this paper we describe the construction of such a teleoperated agricultural robot sprayer that is controlled through a Reality-Based Interaction interface. Two different user interfaces for teleoperating a vineyard spraying robot were experimentally evaluated. In the first condition, participants were provided with a single view (one camera) for teleoperating the robot, whereas in the second condition they had additional views (multiple cameras) supporting peripheral vision and targeted spraying. Analysis of the collected data showed that users in the additional views condition sprayed significantly more grapes and teleoperated the robot with significantly less collisions with obstacles, compared to users who did not have these aids, but also required significantly more time. Participants' perceived usability assessments were not affected by the availability of these additional views.

Applied Ergonomics, 2017

Chi 09 Extended Abstracts on Human Factors in Computing Systems, 2009

Computers in Human Behavior, 2015

International Journal of Human-Computer Studies, 2011

STEM Education: Concepts, Methodologies, Tools, and Applications, 2015

Introducing semi-automatic teleoperation of an agricultural robotic system can enable improved pe... more Introducing semi-automatic teleoperation of an agricultural robotic system can enable improved performance, overcoming the complexity that current autonomous robots face due to the dynamic and unstructured agriculture environment. A teleoperated robot can both leverage the farmers' knowledge and experience while keeping them safe and also help the robot manage the unpredictability of the environment in the field. In this paper we describe the construction of such a teleoperated agricultural robot sprayer that is controlled through a Reality-Based Interaction interface. Two different user interfaces for teleoperating a vineyard spraying robot were experimentally evaluated. In the first condition, participants were provided with a single view (one camera) for teleoperating the robot, whereas in the second condition they had additional views (multiple cameras) supporting peripheral vision and targeted spraying. Analysis of the collected data showed that users in the additional views condition sprayed significantly more grapes and teleoperated the robot with significantly less collisions with obstacles, compared to users who did not have these aids, but also required significantly more time. Participants' perceived usability assessments were not affected by the availability of these additional views.