Direct hand touchable interactions in augmented reality environments for natural and intuitive user experiences

Several studies have been carried out on augmented reality (AR)-based environments that deal with user interfaces for manipulating and interacting with virtual objects aimed at improving immersive feeling and natural interaction. Most of these studies have utilized AR paddles or AR cubes for interactions. However, these interactions overly constrain the users in their ability to directly manipulate AR objects and are limited in providing natural feeling in the user interface. This paper presents a novel approach to natural and intuitive interactions through a direct hand touchable interface in various AR-based user experiences. It combines markerless augmented reality with a depth camera to effectively detect multiple hand touches in an AR space. Furthermore, to simplify hand touch recognition, the point cloud generated by Kinect is analyzed and filtered out. The proposed approach can easily trigger AR interactions, and allows users to experience more intuitive and natural sensations and provides much control efficiency in diverse AR environments. Furthermore, it can easily solve the occlusion problem of the hand and arm region inherent in conventional AR approaches through the analysis of the extracted point cloud. We present the effectiveness and advantages of the proposed approach by demonstrating several implementation results such as interactive AR car design and touchable AR pamphlet. We also present an analysis of a usability study to compare the proposed approach with other well-known AR interactions.     

Predicting user personality by mining social interactions in Facebook

Adaptive applications may benefit from having models of users? personality to adapt their behavior accordingly. There is a wide variety of domains in which this can be useful, i.e., assistive technologies, e-learning, e-commerce, health care or recommender systems, among others. The most commonly used procedure to obtain the user personality consists of asking the user to fill in questionnaires. However, on one hand, it would be desirable to obtain the user personality as unobtrusively as possible, yet without compromising the reliability of the model built. On the other hand, our hypothesis is that users with similar personality are expected to show common behavioral patterns when interacting through virtual social networks, and that these patterns can be mined in order to predict the tendency of a user personality. With the goal of inferring personality from the analysis of user interactions within social networks, we have developed TP2010, a Facebook application. It has been used to collect information about the personality traits of more than 20,000 users, along with their interactions within Facebook. Based on all the collected data, automatic classifiers were trained by using different machine-learning techniques, with the purpose of looking for interaction patterns that provide information about the users? personality traits. These classifiers are able to predict user personality starting from parameters related to user interactions, such as the number of friends or the number of wall posts. The results show that the classifiers have a high level of accuracy, making the proposed approach a reliable method for predicting the user personality     

Haptic rendering: introductory concepts

Haptic rendering allows users to "feel" virtual objects in a simulated environment. We survey current haptic systems and discuss some basic haptic-rendering algorithms. In the past decade we've seen an enormous increase in interest in the science of haptics. Haptics broadly refers to touch interactions (physical contact) that occur for the purpose of perception or manipulation of objects. These interactions can be between a human hand and a real object; a robot end-effector and a real object; a human hand and a simulated object (via haptic interface devices); or a variety of combinations of human and machine interactions with real, remote, or virtual objects. Rendering refers to the process by which desired sensory stimuli are imposed on the user to convey information about a virtual haptic object.     

Awareness marks: adaptive services through user interactions with augmented objects

The ambient intelligence paradigm involves one important challenge: to be adaptive to users and context through simple and natural interactions. To meet this goal, it is important to associate data with relevant everyday objects in the environment, including users themselves, and to enable interaction mechanisms between these objects. Following this premise, in this paper, we present a conceptual model to link contextual information with augmented elements acquired from user interactions in an implicit and transparent way. In this way, it is possible to personalize and enhance offered services in order to facilitate daily user activities. We call this contextual data “awareness marks”, and these awareness marks make it possible to offer novel services adapted from past events that were captured as they happened. Moreover, we have developed and evaluated a set of prototypes using Near Field Communication technology, which follows the presented model.     

Vision-Based Hand Interaction in Augmented Reality Environment

A new vision-based framework and system for human–computer interaction in an Augmented Reality environment is presented in this article. The system allows the users to interact with computer-generated virtual objects using their hands directly. With an efficient color segmentation algorithm, the system is adaptable to different light conditions and backgrounds. It is also suitable for real-time applications. The dominant features on the palm are detected and tracked to estimate the camera pose. After the camera pose relative to the user's hand has been reconstructed, 3D virtual objects can be augmented naturally onto the palm for the user to inspect and manipulate. With off-the-shelf web camera and computer, natural bare-hand based interactions with 2D and 3D virtual objects can be achieved with low cost.     

A Dynamic Gesture Language and Graphical Feedback for Interaction in a 3D User Interface

In user interfaces of modern systems, users get the impression of directly interacting with application objects. In 3D based user interfaces, novel input devices, like hand and force input devices, are being introduced. They aim at providing natural ways of interaction. The use of a hand input device allows the recognition of static poses and dynamic gestures performed by a user's hand. This paper describes the use of a hand input device for interacting with a 3D graphical application. A dynamic gesture language, which allows users to teach some hand gestures, is presented. Furthermore, a user interface integrating the recognition of these gestures and providing feedback for them, is introduced. Particular attention has been spent on implementing a tool for easy specification of dynamic gestures, and on strategies for providing graphical feedback to users' interactions. To demonstrate that the introduced 3D user interface features, and the way the system presents graphical feedback, are not restricted to a hand input device, a force input device has also been integrated into the user interface.     

Predicting user click behaviour in search engine advertisements

According to the specific requirements and interests of users, search engines select and display advertisements that match user needs and have higher probability of attracting users’ attention based on their previous search history. New objects such as user, advertisement or query cause a deterioration of precision in targeted advertising due to their lack of history. This article surveys this challenge. In the case of new objects, we first extract similar observed objects to the new object and then we use their history as the history of new object. Similarity between objects is measured based on correlation, which is a relation between user and advertisement when the advertisement is displayed to the user. This method is used for all objects, so it has helped us to accurately select relevant advertisements for users’ queries. In our proposed model, we assume that similar users behave in a similar manner. We find that users with few queries are similar to new users. We will show that correlation between users and advertisements’ keywords is high. Thus, users who pay attention to advertisements’ keywords, click similar advertisements. In addition, users who pay attention to specific brand names might have similar behaviours too.     

The case analysis on sentiment based ranking of nodes in social media space

Now-a-days, social network sites have become quite popular for communication in the society. People have entangled their day-to-day activities around social media platforms. Social Networks have allowed the users to share their opinions on different topics. In social media, sentiment analysis is an important character to determine opinions of users. Moreover, user’s can be ranked to determine their relative influence. This paper proposes a methodology to rank the users involving sentiment related parameters such as likes, comments and corresponding likescount. Analysis of users’ comments is carried-out. Weights are assigned to these parameters and scores are calculated for each user. Users are ranked on the basis of scores obtained and compared with existing technique. In order to verify the effectiveness of proposed methodology, data is extracted from a verified Facebook page ‘Panjab University, Chandigarh’. Mean, standard deviation and variance are computed to capture the usefulness of ranks obtained by the proposed method. Results depict that the proposed methodology is better than existing technique since it incorporates several features indicating positive and negative behavior of users. This technique can be used to determine the highly trusted and the most distrusted users in a social media user’s profile. Users with negative scores can be considered for outlier analysis. The proposed methodology can also be extended to work on other social media platforms.     

Task-specific information retrieval systems for software engineers

This paper discusses the development of task-specific information retrieval systems for software engineers. We discuss how software engineers interact with information and information retrieval systems and investigate to what extent a domain-specific search and recommendation system can be developed in order to support their work related activities. We have conducted a user study which is based on the “Cognitive Research Framework” to identify the relation between the information objects used during the code development (code snippets and search queries), the tasks users engage in and the associated use of search interfaces. Based on our user studies, a questionnaire and an automated observation of user interactions with the browser and software development environment, we identify that software engineers engage in a finite number of work related tasks and they also develop a finite number of “work practices”/“archetypes of behaviour”. Secondly we identify a group of domain specific behaviours that can successfully be used as a source of strong implicit relevance feedback. Based on our results, we design a snippet recommendation interface, and a code related recommendation interface which are embedded within the standard search engine.     

Distributed Routing of Ads and Bids through Random Walks in the IDOS System

We propose a novel highly distributed system called IDOS (Internet Distributed Objects System) for Buy/Sell interactions on the Internet. In IDOS there is no main or single site that handles user interactions. Instead, each new user “joins” a dynamic graph of users that are currently interested in a specific type of Buy/Sell interaction. The objects for the Buy/Sell interactions are moved between the nodes (users) of the dynamic graph. The Buy/Sell interactions are therefore realized by updating the objects whenever they pass through the current node. This should solve the communication bottleneck caused by the common use of central servers for interactions on the Internet. It does, however, pose a distributed routing problem where messages sent by the users must be distributed between all the “interested” users that are currently connected to the graph. The proposed routing algorithm should overcome the dynamic changes that occur in the graph's topology because some of the users leave the graph while others join it. The proposed solution is to use random walks to distribute the messages, so that the ever-changing topology of the dynamic graph can be overlooked. Consequently, there is no notion of addresses in the system; each user knows only how to communicate with her neighbors. The user must wait until the desired object reaches its node. This simplifies the communication layer, since the centralized client/server TCP/IP infrastructure can be replaced by a point-to-point communication system. We use a system of multiple random “postmen” to overcome the potential communications delay caused by the theoretical large cover-time required by random-walks in graphs. Experimental results of the system as well as how it can be employed to realize public auctions are discussed.     

An efficient posture recognition method using fuzzy logic

Computer-human interaction plays an important role in virtual reality. Glove-based input devices have many desirable features which make direct interactions between the user and the virtual world possible. However, due to the complexity of the human hand, recognising hand functions precisely and efficiently is not an easy task. Existing algorithms are either imprecise or computationally expensive, making them impractical to integrate with VR applications, which are usually very CPU intensive.In the problem of posture and gesture recognition, both the sample patterns stored in the database and the ones to be recognised may be imprecise. This kind of imprecise knowledge can be best dealt with using fuzzy logic. A fast and simple posture recognition method using fuzzy logic is presented in this paper. Our model consists of three components: the posture database, the classifier and the identifier. The classifier roughly classifies the sample postures before they are put into the posture database. The identifier compares an input posture with the records in the identified class and finds the right match efficiently. Fuzzy logic is applied in both the classification and identification processes to cope with imprecise data. The main goal of this method is to recognise hand functions in an accurate and efficient manner. The accuracy, efficiency and the noise tolerance of the model have been examined through a number of experiments.     

Gesture-based interactive augmented reality content authoring system using HMD

This paper proposes an augmented reality content authoring system that enables ordinary users who do not have programming capabilities to easily apply interactive features to virtual objects on a marker via gestures. The purpose of this system is to simplify augmented reality (AR) technology usage for ordinary users, especially parents and preschool children who are unfamiliar with AR technology. The system provides an immersive AR environment with a head-mounted display and recognizes users’ gestures via an RGB-D camera. Users can freely create the AR content that they will be using without any special programming ability simply by connecting virtual objects stored in a database to the system. Following recognition of the marker via the system’s RGB-D camera worn by the user, he/she can apply various interactive features to the marker-based AR content using simple gestures. Interactive features applied to AR content can enlarge, shrink, rotate, and transfer virtual objects with hand gestures. In addition to this gesture-interactive feature, the proposed system also allows for tangible interaction using markers. The AR content that the user edits is stored in a database, and is retrieved whenever the markers are recognized. The results of comparative experiments conducted indicate that the proposed system is easier to use and has a higher interaction satisfaction level than AR environments such as fixed-monitor and touch-based interaction on mobile screens.     

Effect of head-mounted displays on posture

OBJECTIVE: The aim of the present study was to determine if a wearable system based on a head-mounted display (HMD) causes users to alter their head position and adopt postures that place greater stress on the musculoskeletal system. BACKGROUND: HMDs are common output devices used with wearable computers. HMDs provide the wearer with visual information by projecting computer-generated virtual images in front of the eyes. Deviations of neck posture from a neutral upright position increase the stresses on the musculoskeletal system of the head and neck. METHOD: Seven paramedics simulated the treatment of a patient under a normal condition and when using an HMD wearable computer system. During the simulations a posture analysis was performed using the Rapid Upper Limb Assessment method. RESULTS: The postures adopted when wearing an HMD, as compared with a normal condition, scored significantly higher for the neck (z = 2.463, p < .05) and for overall body posture (left side of the body: z = 2.447, p < .05; right side of the body: z = 2.895, p < .05). CONCLUSION: Wearing an HMD can force the wearers to modify their neck posture. As such, the musculoskeletal system of the head and neck may be placed under increased levels of stress. APPLICATION: Potential users should be made aware that HMDs could dictate modifications in neck posture, which may have detrimental effects and may compound the weight effect of the HMD.     

Kinematic and electromyographic differences between mouse and touchpad use on laptop computers

Background

Numerous studies have compared the postures and muscular activities induced by the various input devices available. To the authors' knowledge, no studies have yet compared upper body posture and movement, sEMG activity and muscle co-contractions induced by use of a mouse or of a touchpad.

Objective

The aim of this study was to compare posture, joint excursion and sEMG activity when using a laptop equipped with a mouse or a touchpad.

Methods

Trunk and upper arm posture, ranges of motion and muscle activities were measured in ten subjects during two standardized tasks.

Results

Mouse use induced larger shoulder abduction than touchpad use. On the other hand, when a touchpad was used, the upper arm joints were bound and fixed to a greater extent than during mouse use. Touchpad users are forced to maintain a more static posture. The upper arm electromyography results clearly indicate that touchpad use requires more stabilization than mouse use.

Conclusion

Motor tasks executed by means of the mouse allow a greater range of motions and reduce the biomechanical stress thanks to the greater postural mobility, even though the posture is less neutral. The results of our study tend to suggest that an external mouse should be preferred to the touchpad by frequent users of laptops.

Relevance to industry

This study is a suggestion for IT companies to give customers information of possible advantages using an external mouse. Furthermore our data highlight the importance of providing a mouse to all laptop users in order to reduce biomechanical risks.     

A topology and risk-aware access control framework for cyber-physical space

Cyber-physical space is a spatial environment that integrates the cyber world and the physical world, aiming to provide an intelligent environment for users to conduct their day-to-day activities. The interplay between the cyber space and physical space proposes specific security requirements that are not captured by traditional access control frameworks. On one hand, the security of the physical space and the cyber space should be both concerned in the cyber-physical space. On the other hand, the bad results caused by failure in providing secure policy enforcementmay directly affect the controlled physical world. In this paper, we propose an effective access control framework for the cyber-physical space. Firstly, a topology-aware access control (TAAC) model is proposed. It can express the cyber access control, the physical access control, and the interaction access control simultaneously. Secondly, a risk assessment approach is proposed for the policy enforcement phase. It is used to evaluate the user behavior and ensures that the suspicious behaviors executed by authorized users can be handled correctly. Thirdly, we propose a role activation algorithm to ensure that the objects are accessed only by legal and honest users. Finally, we evaluate our approach by using an illustrative example and the performance analysis. The results demonstrate the feasibility of our approach.     

Generation of efficient and user-friendly queries for helper robots to detect target objects

We are developing a helper robot that carries out tasks ordered by users through speech. The robot needs a vision system to recognize the objects appearing in the orders. However, conventional vision systems cannot recognize objects in complex scenes. They may find many objects and cannot determine which is the target. This paper proposes a method of using a conversation with the user to solve this problem. The robot asks a question to which the user can easily answer and whose answer can efficiently reduce the number of candidate objects. It considers the characteristics of features used for object identification such as the ease for humans to specify them by word, generating a user-friendly and efficient sequence of questions. Experimental results show that the robot can detect target objects by asking the questions generated by the method.     

动态频谱访问无线网络的连通性分析

与传统无线网络不同,在动态频谱访问无线网络中,授权用户对分配的频段具有优先使用权,非授权用户网络的连通性受授权用户的分布和授权用户对频段的使用行为的影响.基于连续渗流理论,证明当授权用户较为稀疏或者负载较轻时,非授权用户可以构成部分连通的网络;反之,当授权用户较为密集并且负载较重时,无法部署部分连通的非授权用户网络.此外,在授权用户和非授权用户共享1个信道的情况下,给出了非授权用户网络存在部分连通性的必要条件.仿真实验数据验证了理论分析的正确性.     

A gesture-free geometric approach for mid-air expression of design intent in 3D virtual pottery

The advent of depth cameras has enabled mid-air interactions for shape modeling with bare hands. Typically, these interactions employ a finite set of pre-defined hand gestures to allow users to specify modeling operations in virtual space. However, human interactions in real world shaping processes (such as pottery or sculpting) are complex, iterative, and continuous. In this paper, we show that the expression of user intent in shaping processes can be derived from the geometry of contact between the hand and the manipulated object. Specifically, we describe the design and evaluation of a geometric interaction technique for bare-hand mid-air virtual pottery. We model the shaping of a pot as a gradual and progressive convergence of the pot’s profile to the shape of the user’s hand represented as a point-cloud (PCL). Thus, a user does not need to learn, know, or remember any gestures to interact with our system. Our choice of pottery simplifies the geometric representation, allowing us to systematically study how users use their hands and fingers to express the intent of deformation during a shaping process. Our evaluations demonstrate that it is possible to enable users to express their intent for shape deformation without the need for a fixed set of gestures for clutching and deforming a shape.     

Users’ quest for an optimized representation of a multi-device space

A plethora of reaching techniques, intended for moving objects between locations distant to the user, have recently been proposed and tested. One of the most promising techniques is the Radar View. Up till now, the focus has been mostly on how a user can interact efficiently with a given radar map, not on how these maps are created and maintained. It is, for instance, unclear whether or not users would appreciate the possibility of adapting such radar maps to particular tasks and personal preferences. In this paper, we address this question by means of a prolonged user study with the Sketch Radar prototype. The study demonstrates that users do indeed modify the default maps in order to improve interactions for particular tasks. It also provides insights into how and why the default physical map is modified.