IBM (United Kingdom)

Wireless sensor networks (WSNs) pose novel challenges compared with traditional networks. To answer such challenges a new communication paradigm, data-centric communication, is emerging. One form of data-centric communication is the publish/subscribe messaging system. Compared with other data-centric variants, publish/subscribe systems are common and wide-spread in distributed computing. Thus, extending publish/subscribe systems intoWSNs will simplify the integration of sensor applications with other distributed applications. This paper describes MQTT-S [1], an extension of the open publish/subscribe protocol message queuing telemetry transport (MQTT) [2] to WSNs. MQTT-S is designed in such a way that it can be run on low-end and battery-operated sensor/actuator devices and operate over bandwidth-constraint WSNs such as ZigBee-based networks. Various protocol design points are discussed and compared. MQTT-S has been implemented and is currently being tested on the IBM wireless sensor networking testbed [3]. Implementation aspects, open challenges and future work are also presented.

Data assimilation is the process by which observations are combined with short-range NWP model output to produce an analysis of the state of the atmosphere at a specified time. Since its inception in the late 1990s, the multiagency Weather Research and Forecasting (WRF) model effort has had a strong data assimilation component, dedicating two working groups to the subject. This article documents the history of the WRF data assimilation effort, and discusses the challenges associated with balancing academic, research, and operational data assimilation requirements in the context of the WRF effort to date. The WRF Model's Community Variational/Ensemble Data Assimilation System (WRFDA) has evolved over the past 10 years, and has resulted in over 30 refereed publications to date, as well as implementation in a wide range of real-time and operational NWP systems. This paper provides an overview of the scientific capabilities of WRFDA, and together with results from sample operation implementations at the U.S. Air Force Weather Agency (AFWA) and United Arab Emirates (UAE) Air Force and Air Defense Meteorological Department.

Web services based on the service-oriented architecture framework provide a suitable technical foundation for making business processes accessible within enterprises and across enterprises. But to appropriately support dynamic business processes and their management, more is needed, namely, the ability to prescribe how Web services are used to implement activities within a business process, how business processes are represented as Web services, and also which business partners perform what parts of the actual business process. In this paper, the relationship between Web services and the management of business processes is worked out and presented in a tutorial-like manner.

Deep neural networks have achieved near-human accuracy levels in various types of classification and prediction tasks including images, text, speech, and video data. However, the networks continue to be treated mostly as black-box function approximators, mapping a given input to a classification output. The next step in this human-machine evolutionary process - incorporating these networks into mission critical processes such as medical diagnosis, planning and control - requires a level of trust association with the machine output. Typically, statistical metrics are used to quantify the uncertainty of an output. However, the notion of trust also depends on the visibility that a human has into the working of the machine. In other words, the neural network should provide human-understandable justifications for its output leading to insights about the inner workings. We call such models as interpretable deep networks. Interpretability is not a monolithic notion. In fact, the subjectivity of an interpretation, due to different levels of human understanding, implies that there must be a multitude of dimensions that together constitute interpretability. In addition, the interpretation itself can be provided either in terms of the low-level network parameters, or in terms of input features used by the model. In this paper, we outline some of the dimensions that are useful for model interpretability, and categorize prior work along those dimensions. In the process, we perform a gap analysis of what needs to be done to improve model interpretability.

Abstract Initially, Grid technologies were principally associated with supercomputer centres and large‐scale scientific applications in physics and astronomy. They are now increasingly seen as being relevant to many areas of e‐Science and e‐Business. The emergence of the Open Grid Services Architecture (OGSA), to complement the ongoing activity on Web Services standards, promises to provide a service‐based platform that can meet the needs of both business and scientific applications. Early Grid applications focused principally on the storage, replication and movement of file‐based data. Now the need for the full integration of database technologies with Grid middleware is widely recognized. Not only do many Grid applications already use databases for managing metadata, but increasingly many are associated with large databases of domain‐specific information (e.g. biological or astronomical data). This paper describes the design and implementation of OGSA‐DAI, a service‐based architecture for database access over the Grid. The approach involves the design of Grid Data Services that allow consumers to discover the properties of structured data stores and to access their contents. The initial focus has been on support for access to Relational and XML data, but the overall architecture has been designed to be extensible to accommodate different storage paradigms. The paper describes and motivates the design decisions that have been taken, and illustrates how the approach supports a range of application scenarios. The OGSA‐DAI software is freely available from http://www.ogsadai.org.uk . Copyright © 2005 John Wiley & Sons, Ltd.

The Enterprise Service Bus (ESB) is the infrastructure which underpins a fully integrated and flexible end-to-end service-oriented architecture (SOA). This paper details the essential meta-data and capabilities of the ESB. It presents a summary of the key concepts of the ESB and defines the integration model for it, including key user roles. These roles are fulfilled using meta-data that describes the service endpoints, such as the service interface and policy requirements and capabilities. The ESB manages this meta-data through a registry, which supports configuration, connection, matchmaking, and discovery of service endpoints. Some typical mediation patterns that are used to satisfy endpoint policies are explored, and usage patterns are described in which the ESB is used to implement real SOAs.

Decimal arithmetic is the norm in human calculations, and human centric applications must use a decimal floating point arithmetic to achieve the same results. Initial benchmarks indicate that some applications spend 50% to 90% of their time in decimal processing, because software decimal arithmetic suffers a 100/spl times/ to 1000/spl times/ performance penalty over hardware. The need for decimal floating point in hardware is urgent. Existing designs, however, either fail to conform to modern standards or are incompatible with the established rules of decimal arithmetic. We introduce a new approach to decimal floating point which not only provides the strict results which are necessary for commercial applications but also meets the constraints and requirements of the IEEE 854 standard. A hardware implementation of this arithmetic is in development, and it is expected that this will significantly accelerate a wide variety of applications.

It would include details of the processes that produced electronic data as far back as the beginning of time or at least the epoch of provenance awareness.

A technique of automatically generating random software test cases is described. The nature of such test cases ensures that they will execute to completion, and their execution is predicted at the time of generation. Wherever possible the test cases are self-checking. At run-time their execution is compared with the predicted execution. Also described are implementations of the technique that have been used to test various IBM programs—/I language processors, sort/merge programs, and Graphical Data Display Manager alphanumeric and graphics support.

SARS-CoV-2 has spread across the world, causing high mortality and unprecedented restrictions on social and economic activity. Policymakers are assessing how best to navigate through the ongoing epidemic, with computational models being used to predict the spread of infection and assess the impact of public health measures. Here, we present OpenABM-Covid19: an agent-based simulation of the epidemic including detailed age-stratification and realistic social networks. By default the model is parameterised to UK demographics and calibrated to the UK epidemic, however, it can easily be re-parameterised for other countries. OpenABM-Covid19 can evaluate non-pharmaceutical interventions, including both manual and digital contact tracing, and vaccination programmes. It can simulate a population of 1 million people in seconds per day, allowing parameter sweeps and formal statistical model-based inference. The code is open-source and has been developed by teams both inside and outside academia, with an emphasis on formal testing, documentation, modularity and transparency. A key feature of OpenABM-Covid19 are its Python and R interfaces, which has allowed scientists and policymakers to simulate dynamic packages of interventions and help compare options to suppress the COVID-19 epidemic.

A 4.9-6.4-Gb/s two-level SerDes ASIC I/O core employing a four-tap feed-forward equalizer (FFE) in the transmitter and a five-tap decision-feedback equalizer (DFE) in the receiver has been designed in 0.13-/spl mu/m CMOS. The transmitter features a total jitter (TJ) of 35 ps p-p at 10/sup -12/ bit error rate (BER) and can output up to 1200 mVppd into a 100-/spl Omega/ differential load. Low jitter is achieved through the use of an LC-tank-based VCO/PLL system that achieves a typical random jitter of 0.6 ps over a phase noise integration range from 6 MHz to 3.2 GHz. The receiver features a variable-gain amplifier (VGA) with gain ranging from -6to +10dB in /spl sim/1dB steps, an analog peaking amplifier, and a continuously adapted DFE-based data slicer that uses a hybrid speculative/dynamic feedback architecture optimized for high-speed operation. The receiver system is designed to operate with a signal level ranging from 50 to 1200 mVppd. Error-free operation of the system has been demonstrated on lossy transmission line channels with over 32-dB loss at the Nyquist (1/2 Bd rate) frequency. The Tx/Rx pair with amortized PLL power consumes 290 mW of power from a 1.2-V supply while driving 600 mVppd and uses a die area of 0.79 mm/sup 2/.

Recent developments in Electropalatography (EPG) as a technique for investigating spatio-temporal details of tongue contacts with the hard palate in both normal and pathological speech are reviewed. Details of hardware and software design for the Reading EPG systems are described and illustrated, including a new multichannel data acquisition system developed as part of an IBM-Reading University collaborative research project.

For a variety of reasons, today's middleware systems are highly complex. This complexity surfaces internally in the middleware construction, and externally in the programming models supported and features offered. We believed that aspect-orientation could help with these problems, and undertook a case study based on members of an IBM® middleware product-line. We also wanted to know whether aspect-oriented techniques could scale to commercial project sizes with tens of thousands of classes, many millions of lines of code, hundreds of developers, and sophisticated build systems. This paper describes the motivation for our research, the challenges involved, and key lessons that we learnt in refactoring both homogeneous and heterogeneous crosscutting concerns in the middleware.

We present here a class of probabilistic algorithms with which one can estimate the number of distinct elements in a collection of data (typically a large file stored on disk) in a single pass, using only 0(1) auxiliary storage and 0(1) operations per element. We precisely quantify the accuracy-storage trade-offs: for instance a typical accuracy of about 5% can be achieved using only 256 binary words, even for very large files. The algorithms are totally insensitive to the replicative structure of the elements in the file. They are particularly adapted to data base systems in the context of query optimization and can be implemented in a decentralized manner (thus making them also useful for distributed data base applications).

BACKGROUND: Sequence exchange between homologous chromosomes through crossing over and gene conversion is highly conserved among eukaryotes, contributing to genome stability and genetic diversity. A lack of recombination limits breeding efforts in crops; therefore, increasing recombination rates can reduce linkage drag and generate new genetic combinations. RESULTS: We use computational analysis of 13 recombinant inbred mapping populations to assess crossover and gene conversion frequency in the hexaploid genome of wheat (Triticum aestivum). We observe that high-frequency crossover sites are shared between populations and that closely related parents lead to populations with more similar crossover patterns. We demonstrate that gene conversion is more prevalent and covers more of the genome in wheat than in other plants, making it a critical process in the generation of new haplotypes, particularly in centromeric regions where crossovers are rare. We identify quantitative trait loci for altered gene conversion and crossover frequency and confirm functionality for a novel RecQ helicase gene that belongs to an ancient clade that is missing in some plant lineages including Arabidopsis. CONCLUSIONS: This is the first gene to be demonstrated to be involved in gene conversion in wheat. Harnessing the RecQ helicase has the potential to break linkage drag utilizing widespread gene conversions.

We have simulated the behaviour of a collection of particles interacting via the anisotropic Gay-Berne potential, using the molecular dynamics technique. The system is found to exhibit both an isotropic liquid and a nematic liquid crystal; the approximate temperature at which the transition between these phases occurs has been determined.

Caring for patients with chronic illnesses is costly—nearly $1.27 trillion today and predicted to grow much larger. To address this trend, we have designed and built a platform, called Personal Care Connect (PCC), to facilitate the remote monitoring of patients. By providing caregivers with timely access to a patient's health status, they can provide patients with appropriate preventive interventions, helping to avoid hospitalization and to improve the patient's quality of care and quality of life. PCC may reduce health-care costs by focusing on preventive measures and monitoring instead of emergency care and hospital admissions. Although PCC may have features in common with other remote monitoring systems, it differs from them in that it is a standards-based, open platform designed to integrate with devices from device vendors and applications from independent software vendors. One of the motivations for PCC is to create and propagate a working environment of medical devices and applications that results in innovative solutions. In this paper, we describe the PCC remote monitoring system, including our pilot tests of the system.

Mobile computing platforms combining small, lightweight, low-power devices with wireless network connectivity enable the performance of familiar tasks in new environments and create opportunities for novel interactions. Since mobility imposes significant cognitive and ergonomic constraints affecting device and application usability, ease of use is central to devices in the fully mobile wirelessly connected (FMWC) world. In this paper, we consider mobility as an attribute both of the computer and the user. We explain the differences between transportable and fully mobile devices, and we contrast applications that are essentially FMWC applications, those that can be adapted to the FMWC context, and those that are unsuitable for it. We discuss the unique challenges to usability for mobile users and devices and their interaction, and we point out the increasingly critical role of usability in the mobile environment.

We present the results of high-resolution AP 3 M SPH simulations of merging clusters of galaxies. We find that the compression and shocking of the core gas during a merger can lead to large increases in bolometric X-ray luminosities and emission-weighted temperatures of clusters. Cooling flows are completely disrupted during equal-mass mergers, with the mass deposition rate dropping to zero as the cores of the clusters collide. The large increase in the cooling time of the core gas strongly suggests that cooling flows will not recover from such a merger within a Hubble time. Mergers with subclumps having one eighth of the mass of the main cluster are also found to disrupt a cooling flow if the merger is head-on. However, in this case the entropy injected into the core gas is rapidly radiated away and the cooling flow restarts within a few Gyr of the merger. Mergers in which the subcluster has an impact parameter of 500 kpc do not disrupt the cooling flow, although the mass deposition rate is reduced by ,30 per cent. Finally, we find that equal mass, off-centre mergers can effectively mix gas in the cores of clusters, while head on mergers lead to very little mixing. Gas stripped from the outer layers of subclumps results in parts of the outer layers of the main cluster being well mixed, although they have little effect on the gas in the core of the cluster. None of the mergers examined here resulted in the intracluster medium being well mixed globally.

<i>Context. <i/>After leaving the main sequence, massive stars undergo complex evolution, a process that is still poorly understood. With a population of hundreds of OB stars, the starburst cluster Westerlund 1 offers an unparallelled environment to study their evolutionary tracks. <i>Aims. <i/>We characterise a large sample of evolved OB stars in the cluster, with the aim of determining cluster parameters and place stars in an evolutionary sequence.<i>Methods. <i/>We used the FORS2 instrument on the VLT to obtain intermediate-resolution spectroscopy over the range 5800-9000 Å of about a hundred stars selected as likely members of the cluster based on their photometry. We developed criteria for their spectral classification using only spectral features in the range observed. We discuss these criteria, useful for spectral classification of early-type stars in the GAIA spectral region, in the appendix. Using these criteria, we obtain spectral classifications, probably accurate to one subtype, for 57 objects, most of which had no previous classification or a generic classification.<i>Results. <i/>We identify more than 50 objects as OB supergiants. We find almost 30 luminous early-B supergiants and a number of less luminous late-O supergiants. In addition, we find a few mid B supergiants with very high luminosity, some of them displaying signs of heavy mass loss. All these stars form a sequence compatible with theoretical evolutionary tracks. In addition, two early B supergiants also show indication of heavy mass loss and may represent the evolutionary phase immediately prior to the Wolf-Rayet stage. We investigate cluster properties using the spectral types and existing photometry. We find that the reddening law to the cluster does not deviate strongly from standard, even though extinction is quite variable, with an average value <i>A<i/><sub>V<sub/><i>=10.8<i/>. Though evolutionary tracks for high-mass stars are subject to large uncertainties, our data support an age of Myr and a distance <i>5~<i/>kpc for Westerlund 1.<i>Conclusions. <i/>The spectral types observed are compatible with a single burst of star formation (the age range is very unlikely to be <i>{>}1<i/> Myr). Westerlund 1 shows its potentiality as a laboratory for massive star evolution, which can be fulfilled by detailed study of the population presented here.