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Computers, Volume 7, Issue 1 (March 2018)

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Research

Open AccessFeature PaperArticle Personalizing the Fitting of Hearing Aids by Learning Contextual Preferences From Internet of Things Data
Computers 2018, 7(1), 1; doi:10.3390/computers7010001
Received: 1 November 2017 / Revised: 9 December 2017 / Accepted: 20 December 2017 / Published: 23 December 2017
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Abstract
The lack of individualized fitting of hearing aids results in many patients never getting the intended benefits, in turn causing the devices to be left unused in a drawer. However, living with an untreated hearing loss has been found to be one of
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The lack of individualized fitting of hearing aids results in many patients never getting the intended benefits, in turn causing the devices to be left unused in a drawer. However, living with an untreated hearing loss has been found to be one of the leading lifestyle related causes of dementia and cognitive decline. Taking a radically different approach to personalize the fitting process of hearing aids, by learning contextual preferences from user-generated data, we in this paper outline the results obtained through a 9-month pilot study. Empowering the user to select between several settings using Internet of things (IoT) connected hearing aids allows for modeling individual preferences and thereby identifying distinct coping strategies. These behavioral patterns indicate that users prefer to switch between highly contrasting aspects of omnidirectionality and noise reduction dependent on the context, rather than relying on the medium “one size fits all” program frequently provided by default in hearing health care. We argue that an IoT approach facilitated by the usage of smartphones may constitute a paradigm shift, enabling continuous personalization of settings dependent on the changing context. Furthermore, making the user an active part of the fitting solution based on self-tracking may increase engagement and awareness and thus improve the quality of life for hearing impaired users. Full article
(This article belongs to the Special Issue Quantified Self and Personal Informatics)
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Open AccessFeature PaperArticle Promises and Pitfalls of Computer-Supported Mindfulness: Exploring a Situated Mobile Approach
Computers 2018, 7(1), 2; doi:10.3390/computers7010002
Received: 1 November 2017 / Revised: 19 December 2017 / Accepted: 21 December 2017 / Published: 22 December 2017
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Abstract
Computer-supported mindfulness (CSM) is a burgeoning area filled with varied approaches such as mobile apps and EEG headbands. However, many of the approaches focus on providing meditation guidance. The ubiquity of mobile devices may provide new opportunities to support mindfulness practices that are
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Computer-supported mindfulness (CSM) is a burgeoning area filled with varied approaches such as mobile apps and EEG headbands. However, many of the approaches focus on providing meditation guidance. The ubiquity of mobile devices may provide new opportunities to support mindfulness practices that are more situated in everyday life. In this paper, a new situated mindfulness approach is explored through a specific mobile app design. Through an experimental design, the approach is compared to traditional audio-based mindfulness meditation, and a mind wandering control, over a one-week period. The study demonstrates the viability for a situated mobile mindfulness approach to induce mindfulness states. However, phenomenological aspects of the situated mobile approach suggest both promises and pitfalls for computer-supported mindfulness using a situated approach. Full article
(This article belongs to the Special Issue Quantified Self and Personal Informatics)
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Open AccessFeature PaperArticle TaPT: Temperature-Aware Dynamic Cache Optimization for Embedded Systems
Computers 2018, 7(1), 3; doi:10.3390/computers7010003
Received: 24 November 2017 / Revised: 19 December 2017 / Accepted: 20 December 2017 / Published: 22 December 2017
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Abstract
Embedded systems have stringent design constraints, which has necessitated much prior research focus on optimizing energy consumption and/or performance. Since embedded systems typically have fewer cooling options, rising temperature, and thus temperature optimization, is an emergent concern. Most embedded systems only dissipate heat
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Embedded systems have stringent design constraints, which has necessitated much prior research focus on optimizing energy consumption and/or performance. Since embedded systems typically have fewer cooling options, rising temperature, and thus temperature optimization, is an emergent concern. Most embedded systems only dissipate heat by passive convection, due to the absence of dedicated thermal management hardware mechanisms. The embedded system’s temperature not only affects the system’s reliability, but can also affect the performance, power, and cost. Thus, embedded systems require efficient thermal management techniques. However, thermal management can conflict with other optimization objectives, such as execution time and energy consumption. In this paper, we focus on managing the temperature using a synergy of cache optimization and dynamic frequency scaling, while also optimizing the execution time and energy consumption. This paper provides new insights on the impact of cache parameters on efficient temperature-aware cache tuning heuristics. In addition, we present temperature-aware phase-based tuning, TaPT, which determines Pareto optimal clock frequency and cache configurations for fine-grained execution time, energy, and temperature tradeoffs. TaPT enables autonomous system optimization and also allows designers to specify temperature constraints and optimization priorities. Experiments show that TaPT can effectively reduce execution time, energy, and temperature, while imposing minimal hardware overhead. Full article
(This article belongs to the Special Issue Multi-Core Systems-On-Chips Design and Optimization)
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Open AccessArticle NEAT-Lamp and Talking Tree: Beyond Personal Informatics towards Active Workplaces
Computers 2018, 7(1), 4; doi:10.3390/computers7010004
Received: 31 October 2017 / Revised: 10 December 2017 / Accepted: 15 December 2017 / Published: 28 December 2017
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Abstract
A growing number of personal informatics (PI) systems have been designed to break the habit of prolonged sitting and to encourage physical activity during workdays and leisure hours. Few studies, however, have investigated the nature of local movement and mobility in workspaces. Relatively
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A growing number of personal informatics (PI) systems have been designed to break the habit of prolonged sitting and to encourage physical activity during workdays and leisure hours. Few studies, however, have investigated the nature of local movement and mobility in workspaces. Relatively little is known about how such movement patterns are shaped and in what ways micro-mobility in workplaces could be increased. By undertaking a concept-driven design approach, and on the basis of our ethnographic prestudy, we introduce a conceptual framework. In this conceptual framework, we indicate the five main agencies that shape local movement and mobility among office workers. On the basis of this empirical and conceptual work, two prototypes, the non-exercise activity thermogenesis (NEAT)-Lamp and Talking Tree, have been designed, implemented and observed in an office environment. This paper describes this design project and articulates the role of discussions in socially established settings in work environments in order to increase daily movement. The paper concludes by highlighting not only technology, but also collective reflections to spark behavioral change in office environments as social settings. Full article
(This article belongs to the Special Issue Quantified Self and Personal Informatics)
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Open AccessArticle DARGS: Dynamic AR Guiding System for Indoor Environments
Computers 2018, 7(1), 5; doi:10.3390/computers7010005
Received: 21 November 2017 / Revised: 14 December 2017 / Accepted: 24 December 2017 / Published: 28 December 2017
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Abstract
Complex public buildings, such as airports, use various systems to guide people to a certain destination. Such approaches are usually implemented by showing a floor plan that has guiding signs or color coded lines on the floor. With a technology that supports six
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Complex public buildings, such as airports, use various systems to guide people to a certain destination. Such approaches are usually implemented by showing a floor plan that has guiding signs or color coded lines on the floor. With a technology that supports six degrees of freedom (6DoF) tracking in indoor environments, it is possible to guide people individually, thereby considering obstacles, path lengths, or pathways for handicapped people. With an augmented reality (AR) device, such as a smart phone or AR glasses, the path can be presented on top of the real environment. In this paper, we present DARGS, an algorithm, which calculates a path through a complex building in real time. Usual path planning algorithms use either shortest paths or dynamic paths for robot interaction. The human factor in a real environment is not considered. The main advantage of DARGS is the incorporation of the current field of view (FOV) of the used device to visualize a more dynamic presentation. Rather than searching for the AR content with a small FOV, with the presented approach the user always gets a meaningful three-dimensional overlay of the path independent of the viewing direction. A detailed user study is performed to prove the applicability of the system. The results indicate that the presented system is especially helpful in the first few important seconds of the guiding process, when the user is still disoriented. Full article
(This article belongs to the Special Issue Advances in Mobile Augmented Reality)
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Open AccessFeature PaperArticle 6DoF Object Tracking based on 3D Scans for Augmented Reality Remote Live Support
Computers 2018, 7(1), 6; doi:10.3390/computers7010006
Received: 30 November 2017 / Revised: 22 December 2017 / Accepted: 29 December 2017 / Published: 2 January 2018
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Abstract
Tracking the 6DoF pose of arbitrary 3D objects is a fundamental topic in Augmented Reality (AR) research, having received a large amount of interest in the last decades. The necessity of accurate and computationally efficient object tracking is evident for a broad base
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Tracking the 6DoF pose of arbitrary 3D objects is a fundamental topic in Augmented Reality (AR) research, having received a large amount of interest in the last decades. The necessity of accurate and computationally efficient object tracking is evident for a broad base of today’s AR applications. In this work we present a fully comprehensive pipeline for 6DoF Object Tracking based on 3D scans of objects, covering object registration, initialization and frame to frame tracking, implemented to optimize the user experience and to perform well in all typical challenging conditions such as fast motion, occlusions and illumination changes. Furthermore, we present the deployment of our tracking system in a Remote Live Support AR application with 3D object-aware registration of annotations and remote execution for delay and performance optimization. Experimental results demonstrate the tracking quality, real-time capability and the advantages of remote execution for computationally less powerful mobile devices. Full article
(This article belongs to the Special Issue Advances in Mobile Augmented Reality)
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Open AccessArticle Self-Monitoring of Emotions and Mood Using a Tangible Approach
Computers 2018, 7(1), 7; doi:10.3390/computers7010007
Received: 1 November 2017 / Revised: 19 December 2017 / Accepted: 19 December 2017 / Published: 8 January 2018
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Abstract
Nowadays Personal Informatics (PI) devices are used for sensing and saving personal data, everywhere and at any time, helping people improve their lives by highlighting areas of good and bad performances and providing a general awareness of different levels of conduct. However, not
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Nowadays Personal Informatics (PI) devices are used for sensing and saving personal data, everywhere and at any time, helping people improve their lives by highlighting areas of good and bad performances and providing a general awareness of different levels of conduct. However, not all these data are suitable to be automatically collected. This is especially true for emotions and mood. Moreover, users without experience in self-tracking may have a misperception of PI applications’ limits and potentialities. We believe that current PI tools are not designed with enough understanding of such users’ needs, desires, and problems they may encounter in their everyday lives. We designed and prototype the Mood TUI (Tangible User Interface), a PI tool that supports the self-reporting of mood data using a tangible interface. The platform is able to gather six different mood states and it was tested through several participatory design sessions in a secondary/high school. The solution proposed allows gathering mood values in an amusing, simple, and appealing way. Users appreciated the prototypes, suggesting several possible improvements as well as ideas on how to use the prototype in similar or totally different contexts, and giving us hints for future research. Full article
(This article belongs to the Special Issue Quantified Self and Personal Informatics)
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Open AccessArticle Performance Evaluation of Discrete Event Systems with GPenSIM
Computers 2018, 7(1), 8; doi:10.3390/computers7010008
Received: 13 December 2017 / Revised: 4 January 2018 / Accepted: 8 January 2018 / Published: 10 January 2018
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Abstract
Petri nets are a useful tool for the modeling and performance evaluation of discrete event systems. Literature reveals that the Petri Net models of real-world discrete event systems are most frequently event graphs (a subclass of Petri nets). Literature also reveals that there
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Petri nets are a useful tool for the modeling and performance evaluation of discrete event systems. Literature reveals that the Petri Net models of real-world discrete event systems are most frequently event graphs (a subclass of Petri nets). Literature also reveals that there are some simple methods for the performance evaluation of event graphs. The general-purpose Petri Net simulator (GPenSIM) is a new simulator that runs on the MATLAB platform. GPenSIM provides a Petri net language, with which Petri net classes and extensions can be developed. GPenSIM also provides functions for performance analysis. Since real-world discrete event systems usually possess a large number of resources, the Petri net models of these systems tend to become huge. Activity-Oriented Petri Nets (AOPN) is an approach that reduces the size of the Petri nets. In addition to the simulator functions, GPenSIM also realizes the AOPN approach on the MATLAB platform. Thus, AOPN is an integral part of GPenSIM. As a running example, a flexible manufacturing system is firstly modeled as an event graph, and then the size of the model is reduced with the AOPN approach. The advantages of GPenSIM and AOPN are discussed in this paper. Full article
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Open AccessArticle An Improvement on Remote User Authentication Schemes Using Smart Cards
Computers 2018, 7(1), 9; doi:10.3390/computers7010009
Received: 4 December 2017 / Revised: 8 January 2018 / Accepted: 12 January 2018 / Published: 15 January 2018
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Abstract
In 2010, Yeh et al. proposed two robust remote user authentication schemes using smart cards; their claims were such that their schemes defended against ID-theft attacks, reply attacks, undetectable on-line password guessing attacks, off-line password guessing attacks, user impersonation attack, server counterfeit attack
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In 2010, Yeh et al. proposed two robust remote user authentication schemes using smart cards; their claims were such that their schemes defended against ID-theft attacks, reply attacks, undetectable on-line password guessing attacks, off-line password guessing attacks, user impersonation attack, server counterfeit attack and man-in-the-middle attack. In this paper, we show that Yeh et al.’s schemes are still vulnerable to ID-theft attack, off-line password guessing attacks, undetectable on-line password guessing attacks and user impersonation attack. Notably, problems remain in situations where the user lost a smart card or the malicious legal user. To remedy these flaws, this paper proposes an improvement on Yeh et al.’s remote user authentication schemes using smart cards. Full article
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