Spyros Panagiotakis

HTML5 and WebSockets; challenges in network 3D collaboration

The emergence of HTML5 and other associated web technologies have turned browser applications to cross-platform and device independent ones. In particular HTML5, WebSockets and X3Dom can shape a diversity of future applications, where the client-server operations will be obsolete. The X3Dom technology combines JavaScript, HTML5 and X3D to provide 3D graphics visualization and interaction in a web-browser without a plug-in. Enriched with a WebSockets implementation for maintaining a persistent and bidirectional TCP connection with a server, a web application can communicate, stream and transfer events or other data to its clients creating a full collaborative 3D environment. In this paper, we introduce an architecture for interactive 3D scenes streaming over the web. We also demonstrate a collaborative 3D web-application for preschool childrens education that capitalizes on the above technologies. Small classes, real or virtual, can be arranged around an instructor who can control the main 3D scenery. The application can provide a positive and encouraging environment for toddlers to interact with computers while recognizing and playing with 3D animated models of popular animals.

Big Data and Cloud Computing: A Survey of the State-of-the-Art and Research Challenges

The proliferation of data warehouses and the rise of multimedia, social media and the Internet of Things (IoT) generate an increasing volume of structured, semi-structured and unstructured data. Towards the investigation of these large volumes of data, big data and data analytics have become emerging research fields, attracting the attention of the academia, industry and governments. Researchers, entrepreneurs, decision makers and problem solvers view ‘big data’ as the tool to revolutionize various industries and sectors, such as business, healthcare, retail, research, education and public administration. In this context, this survey chapter presents a review of the current big data research, exploring applications, opportunities and challenges, as well as the state-of-the-art techniques and underlying models that exploit cloud computing technologies, such as the big data-as-a-service (BDaaS) or analytics-as-a-service (AaaS).

Evaluation of techniques for web 3D graphics animation on portable devices

Providing Internet users with good 3D representations used to be a hard task, not only for web graphic designers but also for web programmers. However, the rapid evolution of SmartPhones has drastically changed the industry. In this paper we attempt to evaluate server and client-side rendering procedures for web 3D animation delivery. Using Ajax and WebSockets, we have developed two discrete instances of a server-side rendering system. We have also implemented an X3Dom equivalent scenario that utilizes X3D and HTML5/WebGL technologies, to emulate client-side rendering on the same environment. The three implementations are evaluated in terms of battery and memory consumption, latency in graphics display and required network resources.

Evaluation of a Web Crowd-Sensing IoT Ecosystem Providing Big Data Analysis

In this chapter, we design and develop an IoT ecosystem for pervasive and crowd-sensing computing, which is based on HTML5 APIs. Our platform is interfaced with the real world through the sensors of various IoT devices in order to group and graphically present the retrieved data following statistical processing. The platform consists of two application-specific components: the first, the client part, runs in the user devices in order to collect sensor data and transmit them to the server; the second, the server part, runs in a cloud computing environment and is responsible for processing, analyzing, and visualizing the Big Data collected from all end devices in a human friendly format, e.g., a map. The application is multisensor as it can collect data from almost all sensors of mobile devices and is totally based on HTML5 features. In the first part of the proposed chapter we will present a brief description of the above platform architecture. Then, we will present an evaluation of the platform’s performance under various wireless access networks (e.g., Wi-Fi, 2G, 3G) in terms of latency. Finally, we will use the platform as a tool for benchmarking various database ecosystems in order to find the pros and cons of adopting different database philosophies in such a web crowd-sensing environment. The tests contain basic commands such as insert data, read data, and search data and some more advanced such as data reading with sorting and data aggregation tests. The database implementations we are benchmarking include both NoSQL (Mongo DB, Redis DB) and SQL approaches (MySQL).

Adaptive video streaming on top of Web3D: A bridging technology between X3DOM and MPEG-DASH

Innovative technologies, implemented in web browsers, have led to the rise of a new era of virtual worlds. Devices with strong hardware installed may now present 3D virtual worlds utilizing user interaction in High Definition (HD) monitors. Recent frameworks such as X3DOM provide a free of plug-ins solution to present interactive 3D graphics and animations within a browser. Furthermore, MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard can be implemented in server-client applications to adapt dynamically the video streaming quality in order to provide the best possible user experience. In this work, we present an approach to extend the adaptation methods of X3DOM by adding a mechanism to perform dynamic adaptation and achieve HD video delivery in 3D Virtual Reality (VR) worlds. We maintain the advantages of both bridged technologies and provide a web-friendly application solution without the requirement of software installation.

Adaptive streaming of complex Web 3D scenes based on the MPEG-DASH standard

Modern Web 3D technologies allow us to display complex interactive 3D content, including models, textures, sounds and animations, using any HTML-enabled web browser. Thus, due to the device-independent nature of HTML5, the same content might have to be displayed on a wide range of different devices and environments. This means that the display of Web 3D content is faced with the same Quality of Experience (QoE) issues as other multimedia types, concerning bandwidth, computational capabilities of the end device, and content quality. In this paper, we present a framework for adaptive streaming of interactive Web 3D scenes to web clients using the MPEG-DASH standard. We offer an analysis of how the standard’s Media Presentation Description schema can be used to describe adaptive Web 3D scenes for streaming, and explore the types of metrics that can be used to maximize the user’s QoE. Then, we present a prototype client we have developed, and demonstrate how the 3D streaming process can take place over such a client. Finally, we discuss how the client framework can be used to design adaptive streaming policies that correspond to real-world scenarios.

Recognizing Driving Behaviour Using Smartphones

In this chapter at first we will present our methodology for recognizing driving patterns using smartphones, and then we will present in detail the android-based application we have developed to this end, which can monitor driving behavior. The latter can be achieved either using data only from the accelerometer sensor or using a sensor fusion method, which combines data from the accelerometer, the gyroscope and the magnetometer. We can recognize events like hard acceleration, safe acceleration, sharp left turn, safe right turn, sharp left lane change, etc. The application to improve the driving behavior of the driver, displays some hint messages to him after each bad-driving event. All the data from the trips (e.g., driving events that take place during a trip), are stored in a database and the driver has the opportunity to review and analyze them whenever he wants. We believe that organizing drivers in some form of a social network and involving them in a game-like procedure for promoting and rewarding the best driver among them, can motivate drivers to more secure driving customs.

Handling Big Data in the Era of Internet of Things (IoT)

In the emerging 5G mobile computing environments, the need for cutting edge technologies regarding data transmission, storage and processing will be more critical than ever. In addition, handling of Big Data that is produced by Internet of Things (IoT) devices and extracting value out of it, is a real challenge for scientists and markets, towards providing extra profit to the society. In this context, this chapter aims to shortly present the correlation between Internet of Things and the expansion of Big Data. At first, a short reference to the evolution of IoT and Big Data is provided and their features are then introduced. In addition, the lifecycle of Big Data in IoT—from capturing to storage and analysis—is shortly described. Finally, two different approaches for the implementation of Big Data are presented, as well as issues in privacy and security are addressed.

Towards Mobile Cloud Computing in 5G Mobile Networks: Applications, Big Data Services and Future Opportunities

The highly computationally capable mobile devices and the continuously increasing demand for high data rates and mobility, which are required by several mobile network services, enabled the research on fifth-generation (5G) mobile networks that are expected to be deployed beyond the year 2020 in order to support services and applications with more than one thousand times of today’s network traffic. On the other hand, the huge and complex location-aware datasets exceed the capability of spatial computing technologies. In this direction, the mobile cloud computing (MCC) technology was introduced as the combination of cloud computing and mobile computing, enabling the end-users to access the cloud-supported services through mobile devices (e.g., smartphones, tablets, portable computers or wearable devices). The mobile applications exploit cloud technologies for data processing, storage and other intensive operations, as they are executed on resource providers external to the devices. This tutorial article is a comprehensive review of the current state-of-the-art and the latest developments on mobile cloud computing under the 5G era, which helps early-stage researchers to have an overview of the existing solutions, techniques and applications and investigate open research issues and future challenges in this domain.

HOLISTIC: An IoT system for residential water recycling based on open source technologies

This paper presents the design and implementation of a novel IT system that aims to monitor, control and manage residential water infrastructures. Even though reusing water and environmental resources has been a hot matter during the last years, there have been few cases where relative and innovative technologies have been applied. More specifically, the system can manage water flows coming from any source in the complex of building and redirect them to tanks or consumption points. The system may thus maximize water recycling and minimize costs for water and also offer recycling automation and policies for individual parts of residential complexes.