Aspect] is a simple and practical aspect-oriented extension to Java With just a few new constructs, AspectJ provides support for modular implementation of a range of crosscutting concerns. In AspectJ's dynamic join point model, join points are well-defined points in the execution of the program; pointcuts are collections of join points; advice are special method-like constructs that can be attached to pointcuts; and aspects are modular units of crosscutting implementation, comprising pointcuts, advice, and ordinary Java member declarations. AspectJ code is compiled into standard Java bytecode. Simple extensions to existing Java development environments make it possible to browse the crosscutting structure of aspects in the same kind of way as one browses the inheritance structure of classes. Several examples show that AspectJ is powerful, and that programs written using it are easy to understand.

An overview of AspectJ

The World is Flat: A Brief History of the Twenty-First Century Thomas L. Friedman Farrar, Straus and Giroux, 2005 Thomas Friedman is a widely-acclaimed journalist, foreign affairs columnist for the New York Times, and author of four best-selling books that include From Beirut to Jerusalem (1989). His eminence as a journalist is clearly demonstrated in the way he prepared for The World is Flat. He traveled throughout the world, interviewing in depth the political and business leaders who have the most direct, hands-on knowledge of the truly incredible developments occurring in the business structures and technology of globalization. Only a journalist who moves freely at the highest levels could interview the likes of Sir John Rose, the chief executive of Rolls-Royce; Nobuyuki Idei, the chairman of Sony; Richard Koo, the chief economist for the Nomura Research Institute; Bill Gates of Microsoft; Wee Theng Tan, the president of Intel China; David Baltimore, president of Caltech; Howard Schultz, founder and chairman of Starbucks; Nandan Nilekani, CEO of Infosys in Bangalore - and many others, each of whom gave him the inside story of how, specifically, the barriers of time and space separating economies, workforces, sources of capital, and technical abilities are crumbling. The result of this unfolding story, already far along but with much farther to go, according to Friedman, is that "the world is flat." With some notable exceptions in sub-Saharan Africa and the Islamic swathe, everything is connected with everything else on a horizontal basis, with distance and erstwhile time-lags no longer mattering. Friedman describes in detail the galloping globalization that has unfolded in even so limited a time as the past five years. Under the impetus of a worldwide network of interconnectivity, the world economy is much-changed from what it was at the turn of the century a mere half-decade ago. Friedman quotes the CEO of India's Infosys: "What happened over the last [few] years is that there was a massive investment in technology, especially in the bubble era, when hundreds of millions of dollars were invested in putting broadband connectivity around the world, undersea cables," while (Friedman paraphrases him) "computers became cheaper and dispersed all over the world, and there was an explosion of software - e-mail, search engines like Google, and proprietary software that can chop up any piece of work and send one part to Boston, one part to Bangalore, and one part to Beijing...." Microprocessors today have 410 million transistors compared to the 2800 they had in 1971. And now, "wireless is what will allow you to take everything that has been digitized, made virtual and personal, and do it from anywhere." The effect on productivity is revolutionary: "It now takes Boeing eleven days to build a 737, down from twenty-eight days just a few years ago. Boeing will build the next generation of planes in three days, because all the parts are computer-designed for assembly." The most strikingly informative aspect of this book, however, is not about technology. Most especially, Friedman explores the rapidly evolving global business systems, each constantly regenerating itself to keep ahead of the others. These are systems that span the continents seeking the lowest-cost providers of everything from expert scientific and engineering work to the lowliest grunt work. Friedman points out that India produces 70,000 accounting graduates each year - and that they are willing to start at $100 a month. It is no wonder that Boeing employs 800 Russian scientists and engineers for passenger-plane design when "a U.S. aeronautical engineer costs $120 per design hour, a Russian costs about one-third of that." Friedman describes a call center in India where outbound callers sell "everything from credit cards to phone minutes," while operators taking inbound calls do "everything from tracing lost luggage for U.S. and European airline passengers to solving computer problems for confused American consumers. …

The World Is Flat: A Brief History of the Twenty-First Century

Recent developments and technological advancements in wireless communication, MicroElectroMechanical Systems (MEMS) technology and integrated circuits has enabled low-power, intelligent, miniaturized, invasive/non-invasive micro and nano-technology sensor nodes strategically placed in or around the human body to be used in various applications, such as personal health monitoring. This exciting new area of research is called Wireless Body Area Networks (WBANs) and leverages the emerging IEEE 802.15.6 and IEEE 802.15.4j standards, specifically standardized for medical WBANs. The aim of WBANs is to simplify and improve speed, accuracy, and reliability of communication of sensors/actuators within, on, and in the immediate proximity of a human body. The vast scope of challenges associated with WBANs has led to numerous publications. In this paper, we survey the current state-of-art of WBANs based on the latest standards and publications. Open issues and challenges within each area are also explored as a source of inspiration towards future developments in WBANs.

Wireless Body Area Networks: A Survey

Advances in wireless communication technologies, such as wearable and implantable biosensors, along with recent developments in the embedded computing area are enabling the design, development, and implementation of body area networks. This class of networks is paving the way for the deployment of innovative healthcare monitoring applications. In the past few years, much of the research in the area of body area networks has focused on issues related to wireless sensor designs, sensor miniaturization, low-power sensor circuitry, signal processing, and communications protocols. In this paper, we present an overview of body area networks, and a discussion of BAN communications types and their related issues. We provide a detailed investigation of sensor devices, physical layer, data link layer, and radio technology aspects of BAN research. We also present a taxonomy of BAN projects that have been introduced/proposed to date. Finally, we highlight some of the design challenges and open issues that still need to be addressed to make BANs truly ubiquitous for a wide range of applications.

Body Area Networks: A Survey

The increasing use of wireless networks and the constant miniaturization of electrical devices has empowered the development of Wireless Body Area Networks (WBANs). In these networks various sensors are attached on clothing or on the body or even implanted under the skin. The wireless nature of the network and the wide variety of sensors offer numerous new, practical and innovative applications to improve health care and the Quality of Life. The sensors of a WBAN measure for example the heartbeat, the body temperature or record a prolonged electrocardiogram. Using a WBAN, the patient experiences a greater physical mobility and is no longer compelled to stay in the hospital. This paper offers a survey of the concept of Wireless Body Area Networks. First, we focus on some applications with special interest in patient monitoring. Then the communication in a WBAN and its positioning between the different technologies is discussed. An overview of the current research on the physical layer, existing MAC and network protocols is given. Further, cross layer and quality of service is discussed. As WBANs are placed on the human body and often transport private data, security is also considered. An overview of current and past projects is given. Finally, the open research issues and challenges are pointed out.

/pdf/a-survey-on-wireless-body-area-networks-f3nx5ii4yv.pdf

A survey on wireless body area networks

Recent advances in microelectronics and integrated circuits, system-on-chip design, wireless communication and intelligent low-power sensors have allowed the realization of a Wireless Body Area Network (WBAN). A WBAN is a collection of low-power, miniaturized, invasive/non-invasive lightweight wireless sensor nodes that monitor the human body functions and the surrounding environment. In addition, it supports a number of innovative and interesting applications such as ubiquitous healthcare, entertainment, interactive gaming, and military applications. In this paper, the fundamental mechanisms of WBAN including architecture and topology, wireless implant communication, low-power Medium Access Control (MAC) and routing protocols are reviewed. A comprehensive study of the proposed technologies for WBAN at Physical (PHY), MAC, and Network layers is presented and many useful solutions are discussed for each layer. Finally, numerous WBAN applications are highlighted.

/pdf/a-comprehensive-survey-of-wireless-body-area-networks-4zgwb61yeq.pdf

A Comprehensive Survey of Wireless Body Area Networks

Wireless body area networks (WBANs) offer many promising new applications in the area of remote health monitoring. An important element in the development of a WBAN is the characterization of the physical layer of the network, including an estimation of the delay spread and the path loss between two nodes on the body. This paper discusses the propagation channel between two half-wavelength dipoles at 2.45 GHz, placed near a human body and presents an application for cross-layer design in order to optimize the energy consumption of different topologies. Propagation measurements are performed on real humans in a multipath environment, considering different parts of the body separately. In addition, path loss has been numerically investigated with an anatomically correct model of the human body in free space using a 3-D electromagnetic solver. Path loss parameters and time-domain channel characteristics are extracted from the measurement and simulation data. A semi-empirical path loss model is presented for an antenna height above the body of 5 mm and antenna separations from 5 cm up to 40 cm. A time-domain analysis is performed and models are presented for the mean excess delay and the delay spread. As a cross-layer application, the proposed path loss models are used to evaluate the energy efficiency of single-hop and multihop network topologies.

/pdf/characterization-of-on-body-communication-channel-and-energy-2s3ew1hxdy.pdf

Characterization of On-Body Communication Channel and Energy Efficient Topology Design for Wireless Body Area Networks

Wireless body area networks (WBANs) form a new and interesting area in the world of remote health monitoring. An important concern in such networks is the communication between the sensors. This communication needs to be energy efficient and highly reliable while keeping delays low. Mobility also has to be supported as the nodes are positioned on different parts of the body that move with regard to each other. In this paper, we present a new cross-layer communication protocol for WBANs: CICADA or Cascading Information retrieval by Controlling Access with Distributed slot Assignment. The protocol sets up a network tree in a distributed manner. This tree structure is subsequently used to guarantee collision free access to the medium and to route data towards the sink. The paper analyzes CICADA and shows simulation results. The protocol offers low delay and good resilience to mobility. The energy usage is low as the nodes can sleep in slots where they are not transmitting or receiving.

A low-delay protocol for multishop wireless body area networks

The population of elderly people keeps increasing rapidly, which becomes a predominant aspect of our societies. As such, solutions both efficacious and cost-effective need to be sought. Ambient Assisted Living (AAL) is a new approach which promises to address the needs from elderly people. Ambient Intelligence technologies are widely developed in this domain aiming to construct safe environments around assisted peoples and help them maintain independent living. However, there are still many fundamental issues in AAL that remain open. Most of the current efforts still do not fully express the power of human being, and the importance of social connections and social activities is less noticed. Our conjecture is that such features are fundamental prerequisites towards truly effective AAL services. This paper reviews the current status of researches on AAL, discusses the promises and possible advantages of AAL, and also indicates the challenges we must meet in order to develop practical and efficient AAL systems for elderly people. In this paper, we also propose an approach to construct effective home-care system for the elderly people.

/pdf/promises-and-challenges-of-ambient-assisted-living-systems-502r69t95z.pdf

Chris Blondia

Papers

A survey on wireless body area networks

A Comprehensive Survey of Wireless Body Area Networks

Characterization of On-Body Communication Channel and Energy Efficient Topology Design for Wireless Body Area Networks

A low-delay protocol for multishop wireless body area networks

Promises and Challenges of Ambient Assisted Living Systems