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Biomechanical analysis of gait is commonly used in physiotherapy. Ground reaction forces during phases of gait is one element of kinetic analysis. In this article, we analyze if the MoveSole® smart insole is valid and accurate equipment for measuring ground reaction forces in clinical physiotherapy. MoveSole® StepLab is a mobile measurement system for instant underfoot force measurements during gait. Unique electromagnetic film (EMFI) based sensor technology and printed electronics production technology is integrated in the MoveSole® StepLab measurement system. The MoveSole® StepLab measures plantar ground reaction force distribution over the sensors and provides an estimation of the maximum total ground reaction force. We developed a two phase validation process to extract relevant parameters and compared the results to a Kistler force plate using the BioWare® analyzing program as a reference method. Our results show that MoveSole® smart insoles reach the strong level of accuracy needed in clinical work concerning highest ground reaction forces during step (Pearson correlation .822 - .875). The correlation of the time when the maximum ground reaction force occurred was moderate, e.g. during heel strike or toe-off (Pearson correlation natural gait speed .351 - .462, maximum gait speed .430). Our conclusion is that MoveSole® smart insoles are a potential tool for analyzing and monitoring gait ground reaction forces during physiotherapy processes.

The increased use of sensor technology has been crucial in releasing the potential for remote rehabilitation. However, it is vital that human factors, that have potential to affect real-world use, are fully considered before sensors are adopted into remote rehabilitation practice. The smart sensor devices for rehabilitation and connected health (SENDoc) project assesses the human factors associated with sensors for remote rehabilitation of elders in the Northern Periphery of Europe. This article conducts a literature review of human factors and puts forward an objective scoring system to evaluate the feasibility of balance assessment technology for adaption into remote rehabilitation settings. The main factors that must be considered are: Deployment constraints, usability, comfort and accuracy. This article shows that improving accuracy, reliability and validity is the main goal of research focusing on developing novel balance assessment technology. However, other aspects of usability related to human factors such as practicality, comfort and ease of use need further consideration by researchers to help advance the technology to a state where it can be applied in remote rehabilitation settings.

Athletic performance, technique assessment, and injury prevention are all important aspects in sports for both professional and amateur athletes. Wearable technology is attracting the research community’s interest because of its capability to provide real-time biofeedback to coaches and athletes when on the field and outside of more restrictive laboratory conditions. In this paper, a novel wearable motion sensor-based system has been designed and developed for athletic performance assessment during running and jumping tasks. The system consists of a number of components involving embedded systems (hardware and software), back-end analytics, information and communications technology (ICT) platforms, and a graphical user interface for data visualization by the coach. The system is able to provide automatic activity recognition, estimation of running and jumping metrics, as well as vertical ground reaction force (GRF) predictions, with sufficient accuracy to provide valuable information as regards training outcomes. The developed system is low-power, sufficiently small for real-world scenarios, easy to use, and achieves the specified communication range. The system’s high sampling rate, levels of accuracy and performance enables it as a performance evaluation tool able to support coaches and athletes in their real-world practice.

Background Older adults may use wearable devices for various reasons, ranging from monitoring clinically relevant health metrics or detecting falls to monitoring physical activity. Little is known about how this population engages with wearable devices, and no qualitative synthesis exists to describe their shared experiences with long-term use. Objective This study aims to synthesize qualitative studies of user experience after a multi-day trial with a wearable device to understand user experience and the factors that contribute to the acceptance and use of wearable devices. Methods We conducted a systematic search in CINAHL, APA PsycINFO, PubMed, and Embase (2015-2020; English) with fixed search terms relating to older adults and wearable devices. A meta-synthesis methodology was used. We extracted themes from primary studies, identified key concepts, and applied reciprocal and refutational translation techniques; findings were synthesized into third-order interpretations, and finally, a “line-of-argument” was developed. Our overall goal was theory development, higher-level abstraction, and generalizability for making this group of qualitative findings more accessible. Results In total, we reviewed 20 papers; 2 evaluated fall detection devices, 1 tested an ankle-worn step counter, and the remaining 17 tested activity trackers. The duration of wearing ranged from 3 days to 24 months. The views of 349 participants (age: range 51-94 years) were synthesized. Four key concepts were identified and outlined: motivation for device use, user characteristics (openness to engage and functional ability), integration into daily life, and device features. Motivation for device use is intrinsic and extrinsic, encompassing many aspects of the user experience, and appears to be as, if not more, important than the actual device features. To overcome usability barriers, an older adult must be motivated by the useful purpose of the device. A device that serves its intended purpose adds value to the user’s life. The user’s needs and the support structure around the device—aspects that are often overlooked—seem to play a crucial role in long-term adoption. Our “line-of-argument” model describes how motivation, ease of use, and device purpose determine whether a device is perceived to add value to the user’s life, which subsequently predicts whether the device will be integrated into the user’s life. Conclusions The added value of a wearable device is the resulting balance of motivators (or lack thereof), device features (and their accuracy), ease of use, device purpose, and user experience. The added value contributes to the successful integration of the device into the daily life of the user. Useful device features alone do not lead to continued use. A support structure should be placed around the user to foster motivation, encourage peer engagement, and adapt to the user’s preferences.

Biomechanical load assessments are becoming increasingly important in the sporting community; however, there are still numerous difficulties in monitoring them in a field environment outside of specialized biomechanical monitoring laboratories. Inertial Measurements Units (IMUs) have been showing promising results in the modeling of biomechanical variables. This study explores the application of an artificial neural network (ANN) in the estimation of runners' vertical ground reaction forces (GRFs) based on the accelerometry collected from two wearable motion sensors developed in-house and attached on the shanks. Data collected from fourteen runners running at three different speeds (8, 10, 12 km/h) were used to train and validate the ANN. Predictions were compared against gold-standard measurements from a pair of pressure in-soles. Root mean square error (RMSE) was used to evaluate the performance of the models. Further investigations, e.g., the use of principal components analysis (PCA) and the impact on the estimation of several GRF-related variables, were carried out to provide useful insights regarding the portability of the model to low-power resource-constrained devices. Findings indicate that ANNs in conjunction with accelerometry may be used to compute vertical ground reaction forces (RMSE: 0.148 BW) and related loading metrics in running accurately.

For the first time, this paper reports a smart museum archive box that features a fully integrated wireless powered temperature and humidity sensor. The smart archive box has been specifically developed for microclimate environmental monitoring of stored museum artifacts in cultural heritage applications. The developed sensor does not require a battery and is wirelessly powered using Near Field Communications (NFC). The proposed solution enables a convenient means for wireless sensing with the operator by simply placing a standard smartphone in close proximity to the cardboard archive box. Wireless sensing capability has the advantage of enabling long-term environmental monitoring of the contents of the archive box without having to move and open the box for reading or battery replacement. This contributes to a sustainable preventive conservation strategy and avoids the risk of exposing the contents to the external environment, which may result in degradation of the stored artifacts. In this work, a low-cost and fully integrated NFC sensor has been successfully developed and demonstrated. The developed sensor is capable of wirelessly measuring temperature and relative humidity with a mean error of 0.37 °C and ±0.35%, respectively. The design has also been optimized for low power operation with a measured peak DC power consumption of 900 μW while yielding a 4.5 cm wireless communication range. The power consumption of the NFC sensor is one of the lowest found in the literature. To the author’s knowledge, the NFC sensor proposed in this paper is the first reporting of a smart archive box that is wirelessly powered and uniquely integrated within a cardboard archive box.

In the last few years, estimating ground reaction forces by means of wearable sensors has come to be a challenging research topic paving the way to kinetic analysis and sport performance testing outside of labs. One possible approach involves estimating the ground reaction forces from kinematic data obtained by inertial measurement units (IMUs) worn by the subject. As estimating kinetic quantities from kinematic data is not an easy task, several models and protocols have been developed over the years. Non-wearable sensors, such as optoelectronic systems along with force platforms, remain the most accurate systems to record motion. In this review, we identified, selected and categorized the methodologies for estimating the ground reaction forces from IMUs as proposed across the years. Scopus, Google Scholar, IEEE Xplore, and PubMed databases were interrogated on the topic of Ground Reaction Forces estimation based on kinematic data obtained by IMUs. The identified papers were classified according to the methodology proposed: (i) methods based on direct modelling; (ii) methods based on machine learning. The methods based on direct modelling were further classified according to the task studied (walking, running, jumping, etc.). Finally, we comparatively examined the methods in order to identify the most reliable approaches for the implementation of a ground reaction force estimator based on IMU data.

In today’s society, the use of watch-based technology is growing steadily and is being used in a wide range of applications and on different aspects of the user’s life, from sport and fitness measurement, to entertainment and healthcare evaluation. Considering the multiple application fields for smartwatch/wristbands and their potential adoption in precision medicine applications, it is thus critical to investigate the performance and accuracy of these devices in different potential scenarios of interest. textbfThis study investigated the performance and accuracy of a variety of commercially available activity trackers as regards the estimation of stepcount, distance, and heart rate in a number of walking/household/sedentary activities typical in everyday life, and recreated in a lab-environment in a study population of young adults. Results show that heart rate and stepcount measurements are accurate but unstandardized activities, such as common domestic or leisure tasks, may cause large errors in some devices. Finally, travelled distance can also represent a quantification challenge when climbing up/downstairs. This preliminary work will support the next phase of the project whose goal is to evaluate elderly subjects in lab- and freeliving environments in an ambient assisted living context.

Ultra Wide Band (UWB) wireless transmission has recently been the object of considerable attention in the field of next generation location aware wireless sensor networks (WSNs). This is due to its fine time resolution, energy efficiency and robustness to interference in harsh environments. This paper presents a thorough applied examination of prototype IEEE 802.15.4a impulse UWB transceiver technology to quantify the effect of line of sight (LOS) and non line of sight (NLOS) ranging in real indoor and outdoor environments. The results included draw on an extensive array of experiments that fully characterize the 802.15.4a UWB transceiver technology, its reliability and ranging capabilities for the first time. The goal of this work is to validate the technology as a dependable wireless communication mechanism for the subset of sensor network localization applications where reliability and precision positions are key concerns.

Internet of Things (IoT) technology is rapidly emerging in medical applications as it offers the possibility of lower-cost personalized healthcare monitoring. At the present time, the 2.45 GHz band is in widespread use for these applications but in this paper, the authors investigate the potential of the 915 MHz ISM band in implementing future, wearable IoT devices. The target sensor is a wrist-worn wireless heart rate and arterial oxygen saturation (SpO2) monitor with the goal of providing efficient wireless functionality and long battery lifetime using a commercial Sub-GHz low-power radio transceiver. A detailed analysis of current consumption for various wireless protocols is also presented and analyzed. A novel 915 MHz antenna design of compact size is reported that has good resilience to detuning by the human body. The antenna also incorporates a matching network to meet the challenging bandwidth requirements and is fabricated using standard, low-cost FR-4 material. Full-Wave EM simulations are presented for the antenna placed in both free-space and on-body cases. A prototype antenna is demonstrated and has dimensions of 44 mm × 28 mm × 1.6 mm. The measured results at 915 MHz show a 10 dB return loss bandwidth of 55 MHz, a peak realized gain of − 2.37 dBi in free-space and − 6.1 dBi on-body. The paper concludes by highlighting the potential benefits of 915 MHz operation for future IoT devices.

The European COMMON SENSE project aims to support the implementation of European Union marine policies such as the Marine Strategy Framework Directive (MSFD). The project has been designed to directly respond to requests for integrated and effective data acquisition systems by developing innovative sensors that will contribute to our understanding of the functioning of marine environments. It aims to develop and provide cost-effective and multi-functional innovative sensors to perform reliable in-situ measurements in the marine environment. The core project research will focus on increasing the availability of standardised data on: eutrophication; concentrations of heavy metals; microplastic fraction within marine litter; underwater noise; and other parameters such as temperature and pressure. This paper will shortly describe the new systems that are developed and the different approaches used during the testing activities.

The goal of this work is to fabricate robust, miniature, wireless sensor modules. These provide an enabling technology platform to conduct research in creating ambient systems, through implementing wireless sensor network applications. The approach taken is to partition the wireless sensor module into a series of layers with area 25mmx25mm. This modular approach has resulted in the specification of a series of layers, including a field programmable gate array layer for digital signal processing type operations, forming the initial elements of the 25mm sensor node toolkit that can be programmed for use with different sensors depending on application. This paper highlights the development of the sensor, processing, communication and power layers, and the connection approach used to form a robust modular system. Comparisons are made with other wireless sensor nodes and application examples are given.

An important problem in pervasive computing is how to create and maintain manageable collections of pervasive resources appropriate for disparate and typically nomadic users. This article describes physical registration, a new, human-centric mechanism for constructing collections of resources in the form of electronic directories. Users identify physical objects using sensor-equipped wirelessly networked handheld devices to build directories of virtual "entities" associated with those objects. The entities can be Web resources accessible over a network, like printers, projectors, picture frames, or storage devices. They can also be Web resources correlated with objects like books or telephones that are not themselves accessible over a network. This article describes and motivates the method, then compares two implementations we have constructed.

The convergence of Web technology, wireless networks, and portable client devices provides new design opportunities for computer/communications systems. In the HP Labs' Cooltown project we have been exploring these opportunities through an infrastructure to support Web presence for people, places and things. We put Web servers into things like printers and put information into Web servers about things like artwork; we group physically related things into places embodied in Web servers. Using URLs for addressing, physical URL beaconing and sensing of URLs for discovery, and localized Web servers for directories, we can create a location-aware but ubiquitous system to support nomadic users. On top of this infrastructure we can leverage Internet connectivity to support communications services. Web presence bridges the World Wide Web and the physical world we inhabit, providing a model for supporting nomadic users without a central control point.

CoolTown offers a Web model for supporting nomadic users, based on the convergence of Web technology, wireless networks and portable devices. This paper describes how CoolTown ties Web resources to physical objects and places, and how users interact with resources using the information appliances they carry, from laptops to smart watches. Enabling the automatic discovery of URLs from our physical surroundings, and using localized Web servers for directories, we create location-aware but ubiquitous systems. On top of this infrastructure we leverage device connectivity to support communication services.

`Appliance' digital devices such as handheld cameras, scanners, and microphones generate data that people want to put on Web pages. Unfortunately, numerous complex steps are required. Contrast this with Web output: handheld Web browsers enjoy increasing infrastructural support such as user-transparent transformation proxies, allowing unmodified Web pages to be conveniently viewed on devices not originally designed for the task. We hypothesize that the utility of input appliances will be greatly increased if they too were `infrastructure enabled'. Appliance Data Services attempts to systematically describe the task domain of providing seamless and graceful interoperability between input appliances and the Web. We offer an application architecture and a validating prototype that we hope will `open up the playing field' and motivate further work. Our initial efforts have identified two main design challenges: dealing with device heterogeneity, and providing a `no-futz' out-of-the-box user experience for novices without sacrificing expressive power for advanced users. We address heterogeneity by isolating device and protocol heterogeneity considerations into a single extensible architectural component, allowing most of the application logic to deal exclusively with Web-friendly protocols and formats. We address the user interface issue in two ways: first, by specifying how to tag input with commands that specify how data are to be manipulated once injected into the infrastructure; second, by describing a late-binding mechanism for these command-tags, which allows `natural' extensions of the device's UI for application selection and minimizes the amount of configuration required before end-users benefit from Appliance Data Services. Finally, we describe how to leverage existing services in the infrastructure; our prototype is based on HTTP and Java but our architecture could also leverage services connected via Jini or CORBA. We also describe an implemented prototype of parts of the architecture and a specific application.

Jalapeno is a virtual machine for JavaTM servers written in the Java language. To be able to address the requirements of servers (performance and scalability in particular), Jalapeno was designed "from scratch" to be as self-sufficient as possible. Jalapeno's unique object model and memory layout allows a hardware null-pointer check as well as fast access to array elements, fields, and methods. Run-time services conventionally provided in native code are implemented primarily in Java. Java threads are multiplexed by virtual processors (implemented as operating system threads). A family of concurrent object allocators and parallel type-accurate garbage collectors is supported. Jalapeno's interoperable compilers enable quasi-preemptive thread switching and precise location of object references. Jalapeno's dynamic optimizing compiler is designed to obtain high quality code for methods that are observed to be frequently executed or computationally intensive.

This work presents the design and evaluation of the REAM (Remote Electricity Actuation and Monitoring) node based around the modular Tyndall Mote platform. The REAM node enables the user to remotely actuate power to a mains power extension board while sampling the current, voltage, power and power factor of the attached load. The node contains a current transformer interfaced to an Energy Metering IC which continuously samples current and voltage. These values are periodically read from the part by a PIC24 microcontroller, which calculates the RMS current and voltage, power factor and overall power. The resultant values can then be queried wirelessly employing the Tyndall 802.15.4 compliant wireless module.

This work performs an extensive charterisation of precision targeted throwing in professional and recreational darts. The goal is to identify the contributing factors for lateral drift or throwing inaccuracy in the horizontal plane. A multi technology approach is adopted whereby a custom built body area network of wireless inertial measurement devices monitor tilt, force and timing, an optical 3D motion capture system provides a complete kinematic model of the subject, electromyography sensors monitor muscle activation patterns and a force plate and pressure mat capture tactile pressure and force measurements. The study introduces the concept of constant throwing rhythm and highlights how landing errors in the horizontal plane can be attributable to a number of variations in arm force and speed, centre of gravity and the movements of some of the bodies non throw related extremities.

This paper proposes a methodology for improved power controller switching in mobile Body Area Networks operating within the ambient healthcare environment. The work extends Anti-windup and Bumpless transfer results to provide a solution to the ambulatory networking problem that ensures sufficient biometric data can always be regenerated at the base station. The solution thereby guarantees satisfactory quality of service for healthcare providers. Compensation is provided for the nonlinear hardware constraints that are a typical feature of the type of network under consideration and graceful performance degradation in the face of hardware output power saturation is demonstrated, thus conserving network energy in an optimal fashion.

The ALSCRIPT program described in this article was developed specifically to allow the easy formatting and graphical display of large multiple alignments. Although written originally for the author's use, the interface is relatively friendly, and should be easy to learn by anyone familiar with plotting graphs

Emerging healthcare applications can benefit enormously from recent advances in pervasive technology and computing. This paper introduces the CLARITY Modular Ambient Health and Wellness Measurement Platform:, which is a heterogeneous and robust pervasive healthcare solution currently under development at the CLARITY Center for Sensor Web Technologies. This intelligent and context-aware platform comprises the Tyndall Wireless Sensor Network prototyping system, augmented with an agent-based middleware and frontend computing architecture. The key contribution of this work is to highlight how interoperability, expandability, reusability and robustness can be manifested in the modular design of the constituent nodes and the inherently distributed nature of the controlling software architecture.Emerging healthcare applications can benefit enormously from recent advances in pervasive technology and computing. This paper introduces the CLARITY Modular Ambient Health and Wellness Measurement Platform:, which is a heterogeneous and robust pervasive healthcare solution currently under development at the CLARITY Center for Sensor Web Technologies. This intelligent and context-aware platform comprises the Tyndall Wireless Sensor Network prototyping system, augmented with an agent-based middleware and frontend computing architecture. The key contribution of this work is to highlight how interoperability, expandability, reusability and robustness can be manifested in the modular design of the constituent nodes and the inherently distributed nature of the controlling software architecture.

A methodology for improved power controller switching in mobile Body Area Networks operating within the ambient healthcare environment is proposed. The work extends Anti-windup and Bumpless transfer results to provide a solution to the ambulatory networking problem that ensures sufficient biometric data can always be regenerated at the base station. The solution thereby guarantees satisfactory quality of service for healthcare providers. Compensation is provided for the nonlinear hardware constraints that are a typical feature of the type of network under consideration and graceful performance degradation in the face of hardware output power saturation is demonstrated, thus conserving network energy in an optimal fashion.

This chapter explores embedded microelectronic sub-systems by first defining the meaning of microelectronics packaging. Increasing the packaging density of electronic products, through techniques such as integral substrates and advanced interconnect, is a key issue. This challenge needs to be addressed inherently through electronic packaging in order to meet consumers demand for light-weight, compact, reliable and multifunctional electronic or communication devices. The technological advances, particularly 3-D packaging, which is driven by consumer demand can also enable concepts such as smart objects, smart spaces and augmented materials. This chapter provides a concise review of selected areas in 3-D packaging and then focuses upon two areas that may provide the type of flexibility and density required for future high-volume smart object development. These techniques are folded flex packaging and chip in laminate/interconnect.

A wireless network system (WSN) has been developed for a team of underwater Collaborative Autonomous Agents (CAAs) that are capable of repairing and locating scale formations in tanks and pipes within inaccessible environments. The design of the hardware is miniaturised and it consists of a stackable 25mm form-factor that includes the appropriate functionality and ISM wireless communications for the application. Sourcing of relevant sensors for the application was based on having the necessary sensing range; being miniature in size and having low power consumption. Once agent functionality was achieved, antennas were placed within the infrastructure of the pipe and CAAs to realise direct and indirect communication for the WSN.

A complete wireless sensor network solution for car-park management is presented in this paper. The system architecture and design are first detailed, followed by a description of the current working implementation, which is based on our DSYS25z sensing nodes. Results of a series of real experimental tests regarding connectivity, sensing and network performance are then discussed. The analysis of link characteristics in the car-park scenario shows unexpected reliability patterns which have a strong influence on MAC and routing protocol design. Two unexpected link reliability patterns are identified and documented. First, the presence of the objects (cars) being sensed can cause significant interference and degradation in communication performance. Second, link quality has a high temporal correlation but a low spatial correlation. From these observations we conclude that a) the construction and maintenance of a fixed topology is not useful and b) spatial rather than temporal message replicates can improve transport reliability.

A robust hybrid intelligent system architecture is being proposed. This communication discusses the prospect of using NMRC's 25mm wireless sensor node in conjunction with other sensor motes. The NMRC node is the Institute's specification for future autonomous transducer nodes in ubiquitous computational networks that will drive the vision of Ambient Intelligence (AmI). A comparative study among different motes with NMRC's node has been performed in order to define a hybrid autonomous sensor network that includes all of them. The main points to differentiate between the NMRC modules and the others are reconfigurability of the module, dense interconnectivity between layers and intensive signal processing capability.

In this demonstration, a new sensor platform named DSYS25 is presented. The platform has a unique hardware design and runs a customized version of the TinyOS operating system. Transceiver hardware and packaging distinguish the D-Systems platform from other available designs.

New and emerging applications can change the mix of operations commonly used within computer architectures. It is sometimes surprising when instruction-set architecture (ISA) innovations intended for one purpose are used for other (initially unintended) purposes. We consider recent proposals for the processor support of families of bit-level permutations. From a processor architecture point of view, the ability to support very fast bit-level permutations may be viewed as a further validation of the basic word-orientation of processors, and their ability to support next-generation secure multimedia processing. However, bitwise permutations are also fundamental operations in many cryptographic primitives and we discuss the suitability of these new operations for cryptographic purposes.

Digital appliances designed to simplify everyday tasks are readily available to end consumers. For example, mobile users can retrieve Web content using handheld devices since content retrieval is well-supported by infrastructure services such as transformational proxies. However, the same type of support is lacking for input-centric devices, those that create content and allow users to share content. This lack of infrastructural support makes input-centric devices hard to use and less useful.The Appliance Data Services project seeks to explore a vision of an appliance computing world where users move data seamlessly among various devices. Based on this vision, we formulate three principles that guide the design of an architecture that helps realize this vision: bring devices to the forefront, minimize the number of device features, and place functionality in the network infrastructure. We evaluate our implementation of the ADS architecture based on these principles, and build applications using the ADS framework to evaluate the ease with which appliance computing applications can be built using the framework. We find that it is relatively simple to build and extend applications on ADS that make using digital devices easier, which results in the devices themselves becoming more useful.

As computer hardware shrinks and lightens and as communications becomes cheaper and more widely available, we have new opportunities for software systems to support nomadic users of ubiquitous or pervasive computing services [16, 24]. We are interested in systems that support interaction with the physical world wherever users happen to be. More and more things in the physical world, such as our cars and domestic appliances, are becoming "smart". Users need a convenient framework in which they can benefit from the smart artifacts around them. Users can also benefit from services built for non-electronic entities that they encounter in their everyday lives, such as goods on the shelves of stores, paintings in galleries and items in the office. We think the physical world and the virtual world would both be richer if they were more closely linked.The approaching pervasiveness of web technology, new kinds of wireless networks, and cheaper portable devices provide an opportunity to construct a virtual bridge between mobile users and physical entities. At HP Labs we have been exploring this opportunity through an infrastructure to support "web presence" for people, places and things [14], and the "CoolTown" demonstrator applications that run on top of the infrastructure [4].In this paper we discuss how we provide mobile people and devices with web-based services for "things" --- the physical entities --- in their environment. Things become web-present by embedding web servers in them or by hosting their web-presence within a web server. To enable services for web things we need a system that connects things and services. We will outline a system that leverages the power of the Web as a basis for nomadic computing, then highlight one important subsystem that uses DNS technology to name web things in a scalable and context dependent fashion.Section 2 describes our use of the Web as 'just enough' middleware for nomadic computing, and describes web presence. Section 3 describes how we tackle the naming issues that arise in providing web presence for the things that mobile users encounter. Section 4 relates our work to that of others and concludes the paper.

Jalapeno is a virtual machine for Java™ servers written in Java.A running Java program involves four layers of functionality: the user code, the virtual-machine, the operating system, and the hardware. By drawing the Java / non-Java boundary below the virtual machine rather than above it, Jalapeno reduces the boundary-crossing overhead and opens up more opportunities for optimization.To get Jalapeno started, a boot image of a working Jalapeno virtual machine is concocted and written to a file. Later, this file can be loaded into memory and executed. Because the boot image consists entirely of Java objects, it can be concocted by a Java program that runs in any JVM. This program uses reflection to convert the boot image into Jalapeno's object format.A special MAGIC class allows unsafe casts and direct access to the hardware. Methods of this class are recognized by Jalapeno's three compilers, which ignore their bytecodes and emit special-purpose machine code. User code will not be allowed to call MAGIC methods so Java's integrity is preserved.A small non-Java program is used to start up a boot image and as an interface to the operating system.Java's programming features — object orientation, type safety, automatic memory management — greatly facilitated development of Jalapeno. However, we also discovered some of the language's limitations.

RC6 has been submitted as a candidate for the Advanced Encryption Standard (AES). Two important features of RC6 that were absent from its predecessor RC5 are a quadratic function and a fixed rotation. By examining simplified variants that omit these features we clarify their essential contribution to the overall security of RC6.