User's Viewpoint Research Articles

Connectivity Analysis of Cognitive Radio Ad-hoc Networks with Shadow Fading

In this paper, we analyze the connectivity of cognitive radio ad-hoc networks in a log-normal shadow fading environment. Considering secondary user and primary user’s locations and primary user’s active state are randomly distributed according to a homogeneous Poisson process and taking into account the spectrum sensing efficiency of secondary user, we derive mathematical models to investigate the connectivity of cognitive radio ad-hoc networks in three aspects and compare with the connectivity of ad-hoc networks. First, from the viewpoint of a secondary user, we study the communication probability of that secondary user. Second, we examine the possibility that two secondary users can establish a direct communication link between them. Finally, we extend to the case of finding the probability that two arbitrary secondary users can communicate via multi-hop path. We verify the correctness of our analytical approach by comparing with simulations. The numerical results show that in cognitive radio ad-hoc networks, high fading variance helps to remarkably improve connectivity behavior in the same condition of secondary user’s density and primary user’s average active rate. Furthermore, the impact of shadowing on wireless connection probability dominates that of primary user’s average active rate. Finally, the spectrum sensing efficiency of secondary user significantly impacts the connectivity features. The analysis in this paper provides an efficient way for system designers to characterize and optimize the connectivity of cognitive radio ad-hoc networks in practical wireless environment.

APP Relationship Calculation: An Iterative Process

Today, plenty of apps are released to enable users to make the best use of their cell phones. Facing the large amount of apps, app retrieval and app recommendation become important, since users can easily use them to acquire their desired apps. To obtain high-quality retrieval and recommending results, it needs to obtain the precise app relationship calculating results. Unfortunately, the recent methods are conducted mostly relying on user's log or app's description, which can only detect whether two apps are downloaded, installed meanwhile or provide similar functions or not. In fact, apps contain many general relationships other than similarity, such as one app needs another app as its tool. These relationships cannot be dug via user's log or app's description. Reviews contain user's viewpoint and judgment to apps, thus they can be used to calculate relationship between apps. To use reviews, this paper proposes an iterative process by combining review similarity and app relationship together. Experimental results demonstrate that via this iterative process, relationship between apps can be calculated exactly. Furthermore, this process is improved in two aspects. One is to obtain excellent results even with weak initialization. The other is to apply matrix product to reduce running time.

Efficient 3-D Scene Prefetching From Learning User Access Patterns

Rendering large-scale 3-D scenes on a thin client is attracting increasing attention with the development of the mobile Internet. Efficient scene prefetching to provide timely data with a limited cache is one of the most critical issues for remote 3-D data scheduling in networked virtual environment applications. Existing prefetching schemes predict the future positions of each individual user based on user traces. In this paper, we investigate scene content sequences accessed by various users instead of user viewpoint traces and propose a user access pattern-based 3-D scene prefetching scheme. We make a relationship graph-based clustering to partition history user access sequences into several clusters and choose representative sequences from among these clusters as user access patterns. Then, these user access patterns are prioritized by their popularity and users’ personal preference. Based on these access patterns, the proposed prefetching scheme predicts the scene contents that will most likely be visited in the future and delivers them to the client in advance. The experiment results demonstrate that our user access pattern-based prefetching approach achieves a high hit ratio and outperforms the prevailing prefetching schemes in terms of access latency and cache capacity.

47.3: Invited Paper: World Fixed Augmented‐Reality HUD for Smart Notifications

In this paper, we present a Head‐Up Display (HUD) system that displays perspective correct surrounding information for driver safety. In our implementation, we display contrast enhanced ego lane information on the HUD during driving conditions with poor visibility. The use of HUD for Augmented Reality (AR) needs an accurate model of the picture generation process for proper visualization of the 3D content that is perspective accurate from the user view point. The system uses multiple computer vision techniques for the accurate visualization.First, we use a camera calibration algorithm that uses view independent spatial geometry and view dependent perspective transformation that compensates for the distortion of the optics as well as the combiner. The calibration is done by capturing the test patterns from the front facing camera located close to the rear view mirror and a camera from the driver's point of view. Further registration of the HUD image is done through a head tracker that uses the camera mounted for the driver monitoring on the steering wheel. The second module detects the lane markings on the road and returns the location of the polygon in the camera co‐ordinate system. The image data bounded by this polygon is further enhanced to reduce the effect of haze, rain and insufficient illumination and blended with the camera input from the front facing camera. The HUD then projects the synthesized image that is perspective correct rendered in the vehicle co‐ordinate system.

An Assessment of Institutional Repositories in the Arab World

Compared to those of the Western world, institutional repositories from the Arabic-speaking countries of the Middle East have been described by scholars of the region as occupying an infancy stage. In this article, repositories from countries in the Arab world were selected and assessed in terms of accessibility and transparency from the viewpoint of an external user. A set of assessment criteria was formed by analyzing trends and similarities in established repositories from the rest of the world, in hopes of analyzing the infancy stage appraisal. The results provide not only a current view of digital scholarship and institutional memory in the Middle East, but may also provide a helpful set of criteria for developing repositories for the rest of the world.

Subliminal Reorientation and Repositioning in Immersive Virtual Environments using Saccadic Suppression.

Virtual reality strives to provide a user with an experience of a simulated world that feels as natural as the real world. Yet, to induce this feeling, sometimes it becomes necessary for technical reasons to deviate from a one-to-one correspondence between the real and the virtual world, and to reorient or reposition the user's viewpoint. Ideally, users should not notice the change of the viewpoint to avoid breaks in perceptual continuity. Saccades, the fast eye movements that we make in order to switch gaze from one object to another, produce a visual discontinuity on the retina, but this is not perceived because the visual system suppresses perception during saccades. As a consequence, our perception fails to detect rotations of the visual scene during saccades. We investigated whether saccadic suppression of image displacement (SSID) can be used in an immersive virtual environment (VE) to unconsciously rotate and translate the observer's viewpoint. To do this, the scene changes have to be precisely time-locked to the saccade onset. We used electrooculography (EOG) for eye movement tracking and assessed the performance of two modified eye movement classification algorithms for the challenging task of online saccade detection that is fast enough for SSID. We investigated the sensitivity of participants to translations (forward/backward) and rotations (in the transverse plane) during trans-saccadic scene changes. We found that participants were unable to detect approximately ±0.5m translations along the line of gaze and ±5° rotations in the transverse plane during saccades with an amplitude of 15°. If the user stands still, our approach exploiting SSID thus provides the means to unconsciously change the user's virtual position and/or orientation. For future research and applications, exploiting SSID has the potential to improve existing redirected walking and change blindness techniques for unlimited navigation through arbitrarily-sized VEs by real walking.

Mobile Games Individualise and Motivate Rehabilitation in Different User Groups

Trials on Mobile Games are presenting a huge potential in cognitive, physical and mental rehabilitation. This paper is to discuss user viewpoints of trials with mobile games combining cognitive sti...

Mobile Games Individualise and Motivate Rehabilitation in Different User Groups

Trials on Mobile Games are presenting a huge potential in cognitive, physical and mental rehabilitation. This paper is to discuss user viewpoints of trials with mobile games combining cognitive stimulation and physical exercise in rehabilitation: Game#1 controlled by tilting the mobile phone embedded in a balance board; Game#2 controlled by tilting the tablet pc; and Game#3 a modified game version of Trail Making A -memory test played by tapping figures on the tablet pc touch screen. The total amount of participants was 89 of which 74% were older adults (women=24; men=33; average age 85.9 years) and 26% people with learning disabilities (n=23; a 38.9 years). The gameplay setting was similar for all target groups, although the game graphics (Game#1) were slightly modified based on each user group. Mobile devices were used as the game platform to create easily approachable games of low costs and suitable for the majority of people.

디지털 기술을 활용한 사용자 체험 혁신전략에 관한 실증적 연구

The purpose of this paper is to study renovation plan of value chain from a user's viewpoint by making practical application of digital technology. And it is surely meaningful to investigate the important motivation factors of continuous using smart-phone, and to analyze the improving effect toward to the * 제1저자 : 노형진 ∙투고일 : 2015. 2. 12, 심사일 : 2015. 2. 18, 게재확정일 : 2015. 2. 25. * 경기대학교 경상대학 경영학과(College of Business and Economics, Kyonggi University) ※ 본 연구는 2014학년도 경기대학교 학술연구비 지원에 의하여 수행되었음. 170 Journal of The Korea Society of Computer and Information March 2015 quality of life in continuous using smart-phone. By this study we can expect the value improving effect of user experience. The results of hypothesis testing can be summarized as follows: First, the hypothesis that positive affect has a plus effect on pragmatic value is accepted. Secondly, the hypothesis that positive affect has a plus effect on hedonic value is accepted. Thirdly, the hypothesis that negative affect has a minus effect on pragmatic value is accepted. Fourthly, the hypothesis that negative affect has a minus effect on pragmatic value is rejected. Fifthly, the hypothesis that pragmatic value has a plus effect on life satisfaction is accepted. Sixthly, the hypothesis that hedonic value has a plus effect on life satisfaction is rejected. In the competition among enterprises, user experience instead of goods themselves became influential as a differential factor. And many advanced enterprises began taking a serious view of customer's happiness and user experience improvement. ▸

Find relationship among applications

Along with extensive use of smart phone, plenty of apps are released to help users. Apps contain many relationships such as one app needs another app to cooperate. This relationship cannot be dug only by user's log or latent contexts. Fortunately, apps seldom appear alone. Almost all the websites allow users to review apps. Apparently, the reviews contain user's viewpoint or judgment. They are consequently useful to dig relationship among apps. Therefore, to dig relationship among apps, this paper proposes an iterative process by combining review similarity and app relationship together. Experimental results demonstrate that, via this iterative process, deep relationship among apps can be dug.

DAEL Framework: A New Adaptive E-learning Framework for Students with Dyslexia

This paper reports on an extensive study conducted on the existing frameworks and relevant theories that lead to a better understanding of the requirements of an e-learning tool for people with dyslexia. The DAEL framework has been developed with respect to four different dimensions: presentation, hypermediality, acceptability and accessibility, and user experience. However, there has been no research on the different types of dyslexia and the dyslexic user's viewpoint as they affect application design. Therefore, in this paper a framework is proposed which would conform to the standards of acceptability and accessibility for dyslexic students. We hypothesise that an e-learning application, which will adopt itself according to individuals’ dyslexia types, will advantage the dyslexics’ individuals in their learning process.

The present conditions and utilization of the latest image analysis to think about in a user viewpoint

The present conditions and utilization of the latest image analysis to think about in a user viewpoint

User-Based Approach to Teaching and Learning Product Design

This paper reports on a senior-level multidisciplinary course titled Innovative Product Design at Florida Atlantic University aimed at teaching and learning one aspect of innovative thinking: Design of products or services from the user viewpoint, i.e., focusing on benefits and ease of use, rather than on product features.Specific objectives of the course are:•To study well-known principles in design interaction, i.e., basic rules that allow design from the user point of view.•To enhance innovative problem solving skills.•To explore creative and innovative processes in product design.•To practice methodologies for design of products and services.•To engage student teams in the design of assistive technologies.This course introduces students from engineering, computer science and business majors to methodologies in design of products and services. Lectures, discussions, and problem solving exercises are used to explore the creative/innovative process in product design. Student teams design assistive technology products based on their knowledge and enhanced innovative skills. For a project to be approved, each team had to interview at least five potential users.The paper focuses mainly on engaging activities, some of which are new. It describes hands-on interactive class exercises, teaming activities, homework assignments, presentations, and projects, most of which relate to the user's point of view. The paper shares some available formal and informal preliminary feedback/evaluation of class topics, material and activities.In order to engage students in more real-life experiences, design experts and specialists in assistive technologies visited the class to teach and mentor students. Among the visitors were the chief product designer of Motorola, and the director of Stand Among Friends, a non-profit organization that helps people with disabilities.The paper shares students’ feedback. They liked the fact that the course teaches design from a totally different perspective, i.e., the user – an unfamiliar aspect to most of them. For some, the concept of design with the user in mind was an “eye opening” experience. They enjoyed prototyping activities (and asked for more) and hands-on experiences that led to prototyping. Open environment and openness to new, simple and absurd ideas were highly appreciated. They have asked for smaller scale projects and for more class time to work on them.

Alternative Perceptions of Statutory Community Aftercare: Patient and Responsible Medical Officer Views

The need for more effective means of caring for mentally disordered individuals in the community has been given a prominent place by the Department of Health. The inclusion of user perspectives in mental health care research, to inform and improve the development of services, has also been given a high priority and the necessity of incorporating patients’ and carers’ views has been recognised by the Department of Health in the National Service Framework for Mental Health published in 1999. Studies incorporating both the service user and professional viewpoints of statutory community care have been relatively sparse. This study, looking at the process of conditional discharge of restricted hospital order patients sought the views on the benefits, deficits and recommendations for change from those people providing and receiving statutory community aftercare. The findings may assist in any future review of the Mental Health Act, policy development and in the planning and delivery of psychiatric services to other groups of severely mentally ill people.

PROPANE

Image-Based Rendering (IBR) has become widely known by its relatively low requirements for generating new scenes based on a sequence of reference images. This characteristic of IBR shows a remarkable potential impact in rendering complex 3D virtual environments on graphics-constrained devices, such as head-mounted displays, set-top boxes, media streaming devices, and so on. If well exploited, IBR coupled with remote rendering would enable the exploration of complex virtual environments on these devices. However, remote rendering requires the transmission of a large volume of images. In addition, existing solutions consider limited and/or deterministic navigation schemes as a means of decreasing the volume of streamed data. This article proposes the PRO gressive PAN orama Str E aming protocol (PROPANE) to offer users a smoother virtual navigation experience by prestreaming the imagery data required to generate new views as the user wanders within a 3D environment. PROPANE is based on a very simple yet effective trigonometry model and uses a strafe (lateral movement) technique to minimize the delay between image updates at the client end. This article introduces the concept of key partial panoramas, namely panorama segments that cover movements in any direction by simply strafing from an appropriate key partial panorama and streaming the amount of lost pixels. Therefore, PROPANE can provide a constrained device with sufficient imagery data to cover a future user's viewpoints, thereby minimizing the impact of transmission delay and jitter. PROPANE has been implemented and compared to two baseline remote rendering schemes. The evaluation results show that the proposed technique outperforms the selected and closely related existing schemes by minimizing the response time while not limiting the user to predefined paths as opposed to previous protocols.

The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations

We discuss the theoretical bases that underpin the automation of the computations of tree-level and next-to-leading order cross sections, of their matching to parton shower simulations, and of the merging of matched samples that differ by light-parton multiplicities. We present a computer program, MadGraph5_aMC@NLO, capable of handling all these computations -- parton-level fixed order, shower-matched, merged -- in a unified framework whose defining features are flexibility, high level of parallelisation, and human intervention limited to input physics quantities. We demonstrate the potential of the program by presenting selected phenomenological applications relevant to the LHC and to a 1-TeV $e^+e^-$ collider. While next-to-leading order results are restricted to QCD corrections to SM processes in the first public version, we show that from the user viewpoint no changes have to be expected in the case of corrections due to any given renormalisable Lagrangian, and that the implementation of these are well under way.

Developing and implementing collaborative research in global mental health: the NIMH Hubs

Abstract Background The US National Institute of Mental Health (NIMH) has stimulated and participated in efforts to identify priorities in global mental health research and facilitate research activities aimed at meeting the greatest challenges. Methods In 2010, we convened clinicians and researchers, service users, representatives from ministries of health, and non-governmental organisations operating in low-income and middle-income countries (LMICs) to discuss what research is needed to reduce the mental health treatment gap. Findings Ensuring that research meets the needs of end-users was a dominant theme. We subsequently developed an initiative, Collaborative Hubs for International Research on Mental Health in Low- and Middle-Income Countries (CHIRMH), with the goal of establishing regional hubs that would conduct public-health-relevant research through strategic collaborations and develop research capacity. Applicants needed to show collaboration with local or regional government agencies and non-governmental organisations that ensured access to service provider and service user viewpoints. The initiative required teams to conduct research on task-sharing for the delivery of mental health interventions, thus addressing the dearth of mental health human resources—one contributor to the treatment gap. Interpretation NIMH currently has four funded Hubs in south Asia, sub-Saharan Africa, and Latin America. Each Hub coordinates a collaborative team of investigators and stakeholders from at least five countries and multiple institutions in a given region. CHIRMH teams have launched studies applying mixed methods to test models of mental health service delivery in various health system environments in LMICs, established research training opportunities, and enriched the mental health research networks in LMICs. Funding NIMH.

Photo-based Desktop Virtual Reality System Implemented on a Web-browser

Abstract : This paper proposes a novel desktop virtual reality system. Based on the position of the user’s face, the proposed system selects the most appropriate image of an object from a set of photographs taken at various angles, and simply “pastes” it onto the display at the appropriate location and scale. Using this system, the users can intuitively feel the presence of the object. Keywords : Virtual reality, Desktop VR, Photo AR, E-Commerce, Digital signage, HTML5/JavaScript 1. Introduction Virtual Reality (VR) has been evolving constantly since its early days, and is now a fundamental technology in different application areas, including scientific and medical visualization, entertainment, video games, education, and training. One of the aims of this study was to apply VR technology to the display of products on electronic commerce (EC) sites and digital signage. Object VR [1] is one of the notable methods that use the photographs of an object taken at various angles and allows the users to observe it from the angle they desire. On the other hand, Object VR requires dragging the mouse of a computer to change the angle. Therefore, the user does not feel the presence of the object in the display during mouse operation. Previously, a photo-based augmented reality (Photo AR) system that uses the photo images of an object captured at various angles instead of rendering a 3D model corresponding to the object during runtime was proposed [2]. With this system, an appropriate photo image for the position and orientation of the user's camera was selected from previously captured and stored images, and then adjusted and simply “pasted” into the camera view. Because Photo AR displays the object as if it exists right in front of the user, it allows the user to intuitively recognize the object better than Object VR. On the other hand, the user needs to move the camera or marker when he/she wants to check the object at a different angle. Although this operation is more intuitive than dragging the mouse, it is not effective enough. Desktop VR, which is commonly referred to as fish tank VR, is a technology that involves the use of a display of a desktop computer coupled with a head tracker that estimates the user’s head position and updates a 3D projection matrix in real-time [3-5]. This system allows the users to observe virtual images through the display as if they were looking into an actual fish tank. He/she feels the presence of a rendered object in the display because no mouse operation is needed. Although, desktop VR does not provide strong immersion, it is suitable for visualization systems because of its ease of use and ability to present high-quality images. The main obstacle encountered when applying desktop VR to EC sites is that 3D models of all viewable products must be prepared in advance. A typical desktop VR system uses three dimensional computer graphics (3DCG) to render the objects required for a given user's viewpoint. These objects are typically authored using 3D modeling programs. These tools are highly expressive but they also tend to be complex and time-consuming. If the number of viewable products is large, the cost of creating these models will in most cases be prohibitive. 3D reconstruction methods have been proposed [6-8] as an alternative to

NoSQL Based 3D City Model Management System

Abstract. To manage increasingly complicated 3D city models, a framework based on NoSQL database is proposed in this paper. The framework supports import and export of 3D city model according to international standards such as CityGML, KML/COLLADA and X3D. We also suggest and implement 3D model analysis and visualization in the framework. For city model analysis, 3D geometry data and semantic information (such as name, height, area, price and so on) are stored and processed separately. We use a Map-Reduce method to deal with the 3D geometry data since it is more complex, while the semantic analysis is mainly based on database query operation. For visualization, a multiple 3D city representation structure CityTree is implemented within the framework to support dynamic LODs based on user viewpoint. Also, the proposed framework is easily extensible and supports geoindexes to speed up the querying. Our experimental results show that the proposed 3D city management system can efficiently fulfil the analysis and visualization requirements.

Estimation of efficiency of protection construction by speech intelligibility criterion

Efficiency of protection constructions is usually estimated by criterion of “signal-to-noise ratio” at the reception point. In this paper it is proposed to use criterion of speech intelligibility, which is more suitable from viewpoint of finite user. Represented results of computer simulation show constructiveness of proposed approach.