Thin Mobile Devices Research Articles

相変化マイクロカプセル（MPCM）を含有する樹脂材料の変形特性およびそのモデル化

In recent years, phase change materials (PCMs) have attracted attention as a temperature regulator for electronic devices. Resin composite materials containing microencapsulated PCM (MPCM) are needed in order to secure the mass of PCM in thin mobile devices. The mechanical properties of resin composite materials containing MPCM have not been clear. In this study, tensile tests and finite element analysis of the MPCM/high density polyethylene (HDPE) composite material are conducted to investigate the effects of MPCM on the mechanical properties of the composite material. Four kinds of the test specimens, such as the mass fraction of MPCM 0% (pure HDPE), 10%, 30% and 50%, were prepared. Young’s modulus, fracture strength and fracture elongation of the specimen are discussed considering the interface strength of HDPE and the melamine resin capsule of MPCM.

A performance evaluation of mobility management and multihop supplying partner strategies for 3D streaming systems over thin mobile devices

SummaryThe recent advances in technology and mobile computing led to the rapid growth of networked 3D streaming applications. The emerging services can involve augmented reality, virtual environment walkthrough, multiplayer gaming just to mention a few. Because of the limited network bandwidth of the client‐server approach, research works are now turning toward mobile ad hoc networks‐based streaming, where the resources of each peer are used during the streaming service. Peer‐to‐peer technologies are considering the solution to adapt for scalable applications. Yet, supplying partner selection and 3D data delivery are still significant challenges to face because of the dynamic wireless environment that causes link breakages, high packet loss, an adverse impact on the quality of the 3D media, and a low user satisfaction. In this paper, we propose a supplying partner selection technique coupled with a content delivery technique for peer‐to‐peer 3D streaming over thin mobile devices. Our proposed protocol, which we refer to as MULTIPLY, considers multihop suppliers in order to alleviate the load on the server and uses the signal strength measurement to analyze the wireless link when sending back the 3D data. Given the high dynamicity of the network due to the mobility of the users, the streaming can be greatly affected. We therefore study the impact of the mobility on MULTIPLY. The performance evaluation of our protocol obtained using an extensive set of simulation experiments is then reported. Copyright © 2013 John Wiley & Sons, Ltd.

Streaming 3D meshes over thin mobile devices

We are witnessing a significant growth in applications using thin mobile devices, such as social networks, virtual walkthrough, massively multiplayer online gaming (MMOG), and augmented reality (AR), just to mention a few. Virtual environments (VE) based class of applications have recently attracted a large number of users. Applications that applied the conventional client-server architecture require the VE to be stored on the client, which is not very feasible due to the client's memory constraints. To address this issue, 3D streaming techniques have been designed and are widely used nowadays. However, several challenges exist and affect the user's Quality of Experience (QoE). By all means, these challenges need to be resolved before the 3D streaming technology over thin mobile devices becomes a commodity. In this paper, we provide a survey on the existing 3D streaming techniques by classifying them based on the nature of the application, and we centralize our attention on methods applied to adapt 3D streaming techniques to the changes in the wireless network conditions. Therefore, we discuss the challenges that the 3D streaming techniques face from a network point of view, as well as the approaches and solutions proposed.

3-D Streaming Supplying Partner Protocols for Mobile Collaborative Exergaming for Health

Childhood obesity is nowadays considered as one of the major health problems that many societies suffer from. The obesity epidemic leads to several life threatening conditions such as diabetes, heart disease, high blood pressure, and mental health problems like depression, anxiety and loneliness just to mention a few. Several approaches, including physical exercises, strict dietary, and exergames among others, have been adopted to address the obesity epidemic. Exergames are considered the innovative approach for fighting several health problem such as the obesity, where a combination of exercise and 3D gaming are proposed to incite kids to exercise as a team. Collaborative exergaming became even more popular given that it addresses the social side of the obesity epidemic, and it motivates kids to socialize with other kids. Traditional exergames are based on the client server approach where the server is responsible for streaming the 3D environment. However, this can lead to latency and server bottleneck if many clients participate in the exergame, which leads to the kids stopping exercising. Having an exergame application that does not suffer from networking problem such as delay, is very important given that it increases the exercise hours. In this work, we propose a new trend of mobile collaborative exergming applications that is based on the peer-to-peer (P2P) architecture, as well as two supplying partner selection protocols that aim at selecting the suitable source responsible for streaming the relevant 3D data. Our system, that we refer to as MOSAIC, is intended for mobile collaborative exergames that incite kids to move inside a large area, using thin mobile devices such as head mounted devices (HMD), have physical exercises, and collaborate with other kids which in consequence address several health problems such as the obesity epidemic on the physical and social plans. Our proposed mobile collaborative exergame aims at inciting the kids to exercise as a team for a longer time by improving the quality of the streaming and reducing the delay. This is accomplished by our proposed supplying partner selection protocols that provide a quick discovery of multiple supplying partners, by minimizing the time required the to acquire data. The performance evaluation we have obtained to evaluate our suite of protocols using a realistic set of exergame scenarios for obese kids is then presented and discussed.

Pushing the 3rd Dimension – Floppy Wafers, Die and Packages? Stress Induced Chip Package Interactions on Thin Mobile Devices

Ever thinner form factors for smart phones, tablets and other mobile devices are driving an aggressive scaling of the semiconductor devices/packages that enable them. A survey of the challenges of this trend points to mechanical stress as the major challenge apart from handling damage. Stress driven Chip Package Interactions impact the manufacturing flow, performance and the reliability of the finished product. We examine a number of the factors and risks driven by mechanical stress and discuss some ideas on how to manage and monitor these issues.

Energy management control for supplying partner selection protocol in mobile peer‐to‐peer three‐dimensional streaming

SUMMARYIn recent years, three‐dimensional (3D) streaming over thin mobile devices has received very little attention from the research community. The 3D streaming‐based class of applications uses either a centralized or a distributed approach. whereas the former presents several drawbacks such as latency, server's bottleneck, and networks congestion; the latter, that is, peer‐to‐peer, has to deal with the supplying partner issue that consists in selecting the source that will be responsible for streaming the required 3D data. Given that frequent 3D streaming overuses the mobile device's resources and dissipates its energy, the energy factor should be taken into consideration during the selection of the supplier. In this paper, we propose two energy management control protocols for supplying partner selection in peer‐to‐peer 3D streaming that we refer to as one‐level energy‐based and two‐level energy‐based. We also propose a new source load estimator that takes into account two factors namely the source's residual energy and its number of served requests. In one‐level energy‐based, the requester uses the source's load information to prioritize the sources in an ascending order and distribute the requests starting with the least loaded sources. In two‐level energy‐based, both the requester and the supplier have important and complementary roles and participate in the energy management control. We then report on the performance evaluation of our energy management control protocols using an extensive set of simulation experiments with the NS2 tool. Copyright © 2011 John Wiley & Sons, Ltd.

Implementation, Measurement, and Analysis of an Image-Based Virtual Environment Streaming Protocol for Wireless Mobile Devices

Remote exploration of detailed virtual environments (VEs) on mobile devices with acceptable frame rates has become a challenging and interesting research topic. With recent advances in mobile computing devices with communication and multimedia capabilities, remote VE walk-through and real-time streaming for mobile devices have opened a new class of 3-D VE exploration-based applications such as virtual guides and malls, online gaming, training, and monitoring, just to name a few. Furthermore, emergency preparedness types of applications can benefit from mobile 3-D visualization systems to support emergency responders with critical information about the disaster area. The combination of sensor networks with VEs can provide a physical environment monitoring and measurement system with live information about the target environment that can be visualized in real time. The challenge lies in how to provide a rich and detailed 3-D VE on thin mobile devices that are known for their lack of proper resources to process large-scale 3-D geometric data. Our approach consists of moving the demanding geometry-rendering task to a dedicated remote rendering server that streams the rendering output to a client, leaving only the displaying and certain minor image-based rendering tasks to the local, less-powerful mobile hardware. In addition, wireless networks pose significant challenges to multimedia streaming due, for the most part, to the mobility-induced changes in bandwidth and errors in the wireless channel. In this paper, we focus on the implementation, measurement, and analysis of an image-based VE streaming strategy. We define a new approach to remote rendering and interactive visualization of 3-D VEs on thin mobile devices. To this end, we propose end-to-end streaming and rate control protocols, as well as buffering and scheduling mechanisms to support the requirements of bandwidth-demanding multimedia systems. The main purpose of our proposed rate control scheme is to achieve both high end-to-end throughput and low frame-rate fluctuation to adapt data traffic to the frequent changes of the bandwidth and error rate present in wireless networks. We discuss the design of our proposed solutions and report on their performance evaluation through an extensive set of simulation experiments.

An end-to-end virtual environment streaming technique for thin mobile devices over heterogeneous networks

Advances in mobile computing devices have resulted in a new class of 3D virtual environment applications such as virtual guides and malls, online gaming, training and monitoring systems, just to name a few. The challenge lies in determining how to provide a rich and detailed 3D virtual environment to these thin devices, since they are known for their lack of the proper resources required to process large scale 3D geometric data. In a wireless scenario, in which bandwidth is highly dynamic, users may experience long delays when downloading an entire 3D environment before they start interacting with it. Furthermore, thin wireless mobile devices are unable to handle the complexity of 3D graphics at interactive frame rates. In this research work, we propose efficient end-to-end streaming and rate control protocols. Our approach consists of moving the demanding geometry-rendering task to a dedicated remote rendering server that streams the rendering output to a client, leaving only the displaying and certain minor image-based rendering tasks to the local, less powerful mobile hardware. We also investigate an image buffer management mechanism in order to deal with the small storage available on thin devices. We discuss the design of our proposed solutions and report on their performance evaluation through an extensive set of simulation experiments.