Mobile phone use among college students is a sedentary leisure behavior which may interfere with exercise

Research suggests that cell phone use is related to sedentary behavior, that cell phone use during exercise reduces intensity, and that high frequency cell phone users are less fit than other users. Thus, cell phone use appears connected to health and fitness behaviors and should be better understood within this context. The present study investigated the sedentary nature of cell phone use, and examined the likelihood of cellphone use interfering with exercise behavior.DesignA validated survey was administered to a random sample of students from a public US university (N = 226).ResultsMean self-reported cell phone use was 380 min day⁻¹, 87% reported cell phone use primarily occurs while sitting, and 70% of use was for leisure. Cell phone use was positively related to sedentary behavior (β = 0.30, p < 0.001). It was not related to physical activity. However, the likelihood of cell phone use during moderate (p = 0.006) and mild (p < 0.001) intensity exercise increased as cell phone use increased.ConclusionLike other screens (e.g., TVs), cell phone use appears to be a sedentary leisure behavior. Furthermore, high frequency use increases the likelihood that it will occur during exercise, likely lowering exercise intensity.     

Examining modality usage in a conversational multimodal application for mobile e-mail access

As Third Generation (3G) networks emerge they provide not only higher data transmission rates but also the ability to transmit both voice and low latency data within the same session. This paper describes the architecture and implementation of a multimodal application (voice and text) that uses natural language understanding combined with a WAP browser to access email messages on a cell phone. We present results from the use of the system by users as part of a laboratory trial that evaluated usage. The user trial also compared the multimodal system with a text-only system that is representative of current products in the market today. We discuss the observed modality issues and highlight implementation problems and usability concerns that were encountered in the trial. Findings indicate that speech was used the majority of the time by participants for both input and navigation even though most of the participants had little or no prior experience with speech systems (yet did have prior experience with text-only access to applications on their phones). To our knowledge this represents the first implementation and evaluation of its kind using this combination of technologies on an unmodified cell phone. Design implications resulting from the study findings and usability issues encountered are presented to inform the design of future conversational multimodal mobile applications.     

Computer literacy across the lifespan: a review with implications for educators

The ability of an individual to interact with a computer, referred to as computer literacy, has been receiving increasing attention in the research literature. However, there appear to be no reviews of the empirical research regarding computer literacy to date. The present article summarizes past and current empirical studies regarding computer literacy that have implications for educators of students of any age, organized by the developmental domains of childhood, young and middle adulthood, and older adulthood.     

Puzzle: A mobile application development environment using a jigsaw metaphor

ObjectiveCreate a visual mobile end user development framework, named Puzzle, which allows end users without IT background to create, modify and execute applications, and provides support for interaction with smart things, phone functions and web services.MethodsDesign of an intuitive visual metaphor and associated interaction techniques for supporting end user development in mobile devices with iterative empirical validation.ResultsOur results show that the jigsaw is an intuitive metaphor for development in a mobile environment and our interaction techniques required a limited cognitive effort to use and learn the framework. Integration of different modalities and usage of smart things was relevant for users.ConclusionPuzzle has addressed the main objective. The framework further contributes to the research on mobile end user development in order to create an incentive for users to go beyond consuming content and applications to start creating their own applications.PracticeUsage of a mobile end user development environment has the potential to create a shift from the conventional few-to-many distribution model of software to a many-to-many distribution model. Users will be able to create applications that fit their requirements and share their achievements with peers.ImplicationsThis study has indicated that the Puzzle visual environment has the potential to enable users to easily create applications and stimulate exploration of innovative scenarios through smartphones.     

Examining proactiveness and choice in a location-aware mobile museum guide

Cultural heritage is an area that has recently drawn research attention, especially for exploring ways to harness novel mobile technologies for supporting visitors. The main benefit of these novel technologies is their ability to provide personalized, context-aware information services to their users. However, the use of context-awareness is connected to a fundamental issue of proactiveness - should the system keep the user in control all the time and only respond to user requests, or should the system take initiative and propose its services when needed? Proactiveness of mobile visitors’ guides brings with it a possibility for better service to the user at the cost of taking control out of the user’s hand. The amount of choice given to visitors is another key issue. With the vast amount of information available for each exhibit, adaptation of the amount of information by limiting the number of content items, could be warranted to filter the information according to the visitors needs. However, it is not clear how reducing choice in terms of the number of content items that are presented to the visitor affects visitor behavior and satisfaction. We examined these issues in a controlled user study conducted with actual museum visitors; comparing usage, behavior patterns, and attitudes of visitors using three versions of a location-aware mobile museum guide.     

Assessing sedentary body movement with accelerometers and domain specific cognitive function during active sitting

The potential physiological and psychological consequences of active sitting are not self-evident. The purpose of this study was to determine how active sitting affects hip motion, as well as domain specific cognitive function. Thirty-seven participants sat for 10 min in three different sitting conditions including a chair with a backrest, chair without a backrest, and an exercise ball. Hip acceleration was monitored using an ActiGraph GT9X Link triaxial accelerometer, and cognitive function was assessed using three different tasks including typing, reading comprehension, and spatial direction estimates. A significant difference in hip acceleration was found between participants that sat on the exercise ball compared to a stool. Additionally, the participants sitting on the ball attempted fewer total direction estimates and fewer egocentric-based direction estimates than the participants who sat on the stool. There may be little or no cognitive benefit to active sitting for many typical work tasks.     

Examining the infusion of mobile technology by healthcare practitioners in a hospital setting

While mobile Health (mHealth) holds much potential, the infusion of mHealth is still in its infancy and has yet to achieve sufficient attention in the Information Systems field. As a result, the objective of this paper is to identify the (a) determinants for successful infusion of mHealth by healthcare practitioners and (b) benefits healthcare practitioners perceive from infusing mHealth. A sequential mixed methods approach (case study and survey) is employed to achieve this objective. The study contributes to IS theory and practice by: (1) developing a model with six determinants (Availability, Self-Efficacy, Time-Criticality, Habit, Technology Trust, and Task Behaviour) and three individual performance-related benefits associated with mHealth infusion (Effectiveness, Efficiency, and Learning), (2) exploring undocumented determinants and relationships, (3) identifying conditions that both healthcare practitioners and organisations can employ to assist with mHealth infusion and (4) informing healthcare organisations and vendors as to the performance of mHealth in post-adoptive scenarios.     

移动机器人步长调整算法的S函数应用研究

机器人在对于一些气味源、声源、平衡位置等目标搜索时,为了精确定位,一般采用变步长的算法。根据S函数,设计出了一种新型步长调整算法。与传统的最陡下降法相比,其步长调整速度快,适应外部环境能力强,并且包含了方向信息。实验证明该方法是一种有效的移动机器人步长调整算法。     

Tracking control of a nonholonomic mobile robot using compound cosine function neural networks

The purpose of this paper is to propose a compound cosine function neural network with continuous learning algorithm for the velocity and orientation angle tracking control of a nonholonomic mobile robot with nonlinear disturbances. Herein, two neural network (NN) controllers embedded in the closed-loop control system have the simple continuous learning and rapid convergence capability without the dynamics information of the mobile robot to realize the adaptive control of the mobile robot. The neuron function of the hidden layer in the three-layer feed-forward network structure is on the basis of combining a cosine function with a unipolar sigmoid function. The developed neural network controllers have simple algorithm and fast learning convergence because the weight values are only adjusted between the nodes in hidden layer and the output nodes, while the weight values between the input layer and the hidden layer are one, i.e. constant, without the weight adjustment. Therefore, the main advantages of this control system are the real-time control capability and the robustness by use of the proposed neural network controllers for a nonholonomic mobile robot with nonlinear disturbances. Through simulation experiments applied to the nonholonomic mobile robot with the nonlinear disturbances which are considered as dynamics uncertainty and external disturbances, the simulation results show that the proposed NN control system of nonholonomic mobile robots has real-time control capability, better robustness and higher control precision. The compound cosine function neural network provides us with a new way to solve tracking control problems for mobile robots.     

Effects of a standing and three dynamic workstations on computer task performance and cognitive function tests

Sedentary work entails health risks. Dynamic (or active) workstations, at which computer tasks can be combined with physical activity, may reduce the risks of sedentary behaviour. The aim of this study was to evaluate short term task performance while working on three dynamic workstations: a treadmill, an elliptical trainer, a bicycle ergometer and a conventional standing workstation. A standard sitting workstation served as control condition. Fifteen Dutch adults performed five standardised but common office tasks in an office-like laboratory setting. Both objective and perceived work performance were measured. With the exception of high precision mouse tasks, short term work performance was not affected by working on a dynamic or a standing workstation. The participant's perception of decreased performance might complicate the acceptance of dynamic workstations, although most participants indicate that they would use a dynamic workstation if available at the workplace.     

Location determination of mobile devices for an indoor WLAN application using a neural network

Due to the popularity of location-based services, determining the location of a device at all times has become a subject of great interests. Although many GPS-based applications have been developed and successfully deployed in various fields, their applicabilities are hindered by the obstruction of the objects in the environment. Essentially, as satellite signals cannot penetrate the walls of buildings, the coverage of GPS systems is limited to outdoor environments. To fully exploit the benefit of location-based services, approaches that determine the location of a device in indoor environments need to be established. This study presents a novel location determination mechanism that uses an indoor WLAN and back-propagation neural network (BPN). A museum is taken as the context of the example indoor environment. Location determination is achieved using the combined strengths of 802.11b wireless access signals. With a significant number of access points (APs) installed in the museum, hand-held devices can sense the strengths of the signals from all APs to which the devices can connect. Using a back-propagation network, device locations can be estimated with sufficient accuracy. A novel adaptive algorithm is implemented for enhancing the accuracy of the estimation.

Optimization of user experience in mobile application design by using a fuzzy analytic-network-process-based Taguchi method

Mobile application (app) design is an expanding research area, with user experience (UX) as its core. UX encompasses all aspects of human–computer interaction, and thus the optimization of UX has multiple objectives. Quality characteristics related to UX are subjective and even subconscious; moreover, there exists interdependence among UX quality characteristics. However, very little attention has been focused on these issues when optimizing UX based on multiple objectives. In this paper, a fuzzy analytic network process (ANP)-based Taguchi method is proposed for optimizing UX in mobile app design. First, design patterns and UX quality characteristics are determined. Subsequently, a Taguchi experiment is designed and carried out, and then signal-to-noise (S/N) ratios are calculated. A fuzzy ANP is adopted to derive the preference weights for the UX quality characteristics. Based on these weights, the S/N ratios are converted into a multiperformance characteristic index (MPCI) by using the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). Finally, according to the MPCI, the significant design patterns are identified by using the analysis of variance, and the optimal design is obtained by using the response table and response graph. A mobile health app design was presented to illustrate the proposed approach. The results suggest that the proposed approach can effectively manage the interdependence among the subjective and even subconscious UX quality characteristics in the optimization process, and be used as a universal robust design approach to optimize UX in mobile app design.     

Factors affecting reposting behaviour using a mobile phone-based user-generated-content online community application among Chinese young adults

Mobile phone-based user-generated-content (UGC) online community applications have gained increasing popularity among young generations. However, factors that may affect usage behaviour regarding the applications are not fully investigated. In this study, we employed the Technology Acceptance Model as the basis to explore factors that are able to predict user reposting behaviour with the applications. University students (N?=?322) completed a self-reported questionnaire for measuring the studied constructs after they experienced a high-fidelity prototype of a mobile UGC online community application. Results from path analysis demonstrated that perceived usefulness and attitude towards usage were significant determinants of user reposting intention, with 23% of its variance explained. Perceived usefulness, perceived ease of use and information credibility directly predicted attitude towards usage and accounted for 45% of its variance. Perceived ease of use exerted influence on both perceived usefulness and information credibility. The findings can enhance our understanding of factors that contribute to user reposting behaviour and provide insight into design and implementation strategies to increase the likelihood of user intention to repost information using mobile UGC online community applications.     

Training and assessing numerical abilities across the lifespan with intelligent systems: The example of Baldo

Baldo is an intelligent system that can be used to assess and train numerical abilities across the lifespan, especially for children and elderly. Baldo includes digital and tangible materials to propose activities, built on the game-based learning approach, strongly grounded on well-known and experimentally supported theories about numerical and mathematical cognition. Moreover, Baldo has a special module devoted to motivational and affective dimensions related to mathematic cognition and a tutoring system to select specific activities that are adequate to the actual and potential level of the people involved in the training pathway.     

Selecting representative affective dimensions using Procrustes analysis: an application to mobile phone design

Collecting affective responses (ARs) from consumers is crucial to designers aspiring to produce an appealing product. Adjectives are frequently used by researchers as an affective means by which consumers can describe their subjective feelings regarding a specific product design. This study proposes a Kansei engineering (KE) approach for selecting representative affective dimensions using factor analysis (FA) and Procrustes analysis (PA). A semantic differential (SD) experiment is used to examine consumers' ARs toward a set of representative product samples. FA is employed to extract the underlying latent factors using an initial set of affective dimensions. A backward elimination process based on PA is used to determine the relative significance of adjectives in each step according to the calculated residual sum of squared differences (RSSDs) to finally obtain the ranking of the initial set of adjectives. Additionally, the results of the proposed approach are compared to the method that combines FA and two-stage cluster analysis (CA). A case study of mobile phone design is provided to demonstrate the analysis results.     

Indoor navigation of a non-holonomic mobile robot using a visual memory

When navigating in an unknown environment for the first time, a natural behavior consists on memorizing some key views along the performed path, in order to use these references as checkpoints for a future navigation mission. The navigation framework for wheeled mobile robots presented in this paper is based on this assumption. During a human-guided learning step, the robot performs paths which are sampled and stored as a set of ordered key images, acquired by an embedded camera. The set of these obtained visual paths is topologically organized and provides a visual memory of the environment. Given an image of one of the visual paths as a target, the robot navigation mission is defined as a concatenation of visual path subsets, called visual route. When running autonomously, the robot is controlled by a visual servoing law adapted to its nonholonomic constraint. Based on the regulation of successive homographies, this control guides the robot along the reference visual route without explicitly planning any trajectory. The proposed framework has been designed for the entire class of central catadioptric cameras (including conventional cameras). It has been validated onto two architectures. In the first one, algorithms have been implemented onto a dedicated hardware and the robot is equipped with a standard perspective camera. In the second one, they have been implemented on a standard PC and an omnidirectional camera is considered.

Analog circuit for motion detection using a CCD camera based on a biological vision system and its application to mobile robots

We have proposed an analog motion detection circuit based on a biological vision system. A charge coupled device (CCD) camera was used as the input in order to obtain an input image. By using the CCD camera, it is possible to detect the movement of an object as a high-resolution image. Because the unit motion detection circuit is constructed with eight metal oxide semiconductor (MOS) transistors and one capacitor, the structure of the unit circuit is simple. The test circuit was constructed on a circuit board using discrete MOS transistors. The results from the test circuit showed that it can detect the direction of motion. The test circuit was connected to a microcomputer in a mobile robot. It was clear from the results that the motion detection circuit can control a mobile robot.     

Changes in physical capacity as a function of age in heavy manual work

The objective of this study was to assess the changes in the physical capacity as a function of age in power line technicians (PLTs). The physical test was designed to closely represent the essential physical tasks of the occupation that were identified through a detailed job demand analysis. The results from the physical test showed that six out of nine test variables did not demonstrate a statistical difference between the mean scores of young (? 39 years) and old age (50 + years) groups. However the older group scored significantly lower in the aerobic capacity test, one-handed pull down, and both right and left standard handgrip tests. Despite these differences the older PLT appears to meet and exceed the physical requirements necessary to carry out the essential tasks of this trade. However a physical test with a high level of content and construct validity is necessary to accurately evaluate the workers physical capacity in relation to the job demands. Based on the principal of specificity for muscle training and testing, this study has demonstrated that heavy manual work appears to maintain physical capacity specific to the task as age progresses.     

Global path planning of mobile robots using a memetic algorithm

In this paper, a memetic algorithm for global path planning (MAGPP) of mobile robots is proposed. MAGPP is a synergy of genetic algorithm (GA) based global path planning and a local path refinement. Particularly, candidate path solutions are represented as GA individuals and evolved with evolutionary operators. In each GA generation, the local path refinement is applied to the GA individuals to rectify and improve the paths encoded. MAGPP is characterised by a flexible path encoding scheme, which is introduced to encode the obstacles bypassed by a path. Both path length and smoothness are considered as fitness evaluation criteria. MAGPP is tested on simulated maps and compared with other counterpart algorithms. The experimental results demonstrate the efficiency of MAGPP and it is shown to obtain better solutions than the other compared algorithms.     

可信计算在移动支付中的应用研究

随着移动互联网的不断普及和移动电子商务的发展,使得移动终端（如手机,PAD）成为更加便捷的交易终端,移动支付已经渗透到移动通信、金融等众多领域。如何构建安全便捷、可信赖的移动电子支付环境,成为信息安全领域关注的热点之一。