bluuebunny/crossref_metadata_2025 huggingface dataset:
Comments on the dilemma in the September issue: ‘What if it was your dog?’
Authors: Mullan Siobhan
Published: October 2012

The dilemma in the September issue dealt with vets attempting to put themselves in clients' shoes. Practitioners are often asked what they would do if the animal was actually their own, and it can be difficult to know how best to answer (In Practice, September 2012, volume 34, pp 494‐495). Steven McCulloch considered the different permutations of what the question, ‘What if it was your dog?’, might actually mean. The first involved the vet taking only their own moral values and practical resource base into consideration. Alternatively, the practitioner could answer based on their own moral values but the specific client's resource base. The third interpretation involved deciding on the dog's treatment based solely on the morals and resources of the particular owner. He suggested that answering the question based on the second interpretation was a possible way forward, as it seemed reasonable to believe this was essentially what the client wanted to know. After having answered the question, a brief explanation by the vet, of what their professional judgement was based on, could help foster the client's trust and open up discussion about treatment options.
Head and ocular surgery in farm animals
Authors: Potter Timothy J. , Hallowell Gayle D. , Aldridge Brian
Published: October 2012

Head surgery is commonly undertaken in large animal practice and there are a number of procedures that can be accomplished in the field. This article covers some of the commonly performed ocular and head surgeries along with the appropriate local anaesthetic techniques.
Conditions of the feline pelvic region
Authors: Witte Philip , Scott Harry
Published: October 2012

Feline pelvic disease may result in hindlimb lameness, dysfunction of the terminal urogenital and gastrointestinal tracts, internal haemorrhage and pain. Long‐term sequelae include chronic hindlimb lameness and/or neurological dysfunction, urinary or faecal incontinence, obstipation and dystocia. Conditions of the feline pelvis and hips are most commonly of traumatic aetiology, with up to one third of cat fractures involving the pelvis. Nonetheless, the general practitioner should be aware of the few conditions of the feline pelvis which occur in the absence of trauma. This article focuses on the diagnosis, clinical significance and therapy of conditions of the pelvis, sacrum and hip joints in the cat, traumatic and otherwise. Analogous conditions exist in dogs, and the differences between the two species are highlighted.
Brucellosis – what every practitioner should know
Authors: Millar Michael , Stack Judy
Published: October 2012

Brucellosis is a worldwide zoonotic disease that can be associated with significant economic and welfare problems in livestock. There are currently 10 reported species of Brucella, which have an affinity for different hosts and vary in pathogenicity and zoonotic potential. This article discusses the effect of Brucella infection on cattle and other animals, the diagnostic methods employed to detect the disease, and the surveillance measures undertaken to ensure Great Britain remains brucellosis free.
Analgesic constant rate infusions in dogs and cats
Authors: Bromley Nicola
Published: October 2012

Analgesic constant rate infusions (CRIs) have become more popular in recent years and are a very effective way of providing analgesia. This article gives an overview of the most common analgesic CRIs, their indications and practical guidance on how to use them in daily practice. It also considers transdermal analgesia.
Sedation and analgesia in the standing horse 1. Drugs used for sedation and systemic analgesia
Authors: Michou Joanne , Leece Elizabeth
Published: October 2012

Many surgical and diagnostic procedures can be performed safely and humanely in conscious horses by using a combination of sedation, analgesia and local anaesthetic techniques. This article discusses sedatives and analgesics, including drugs that are administered intravenously, intramuscularly, orally or transmucosally. Drugs administered by infiltration, and/or the epidural, perineural or intra‐articular routes to provide local analgesia will be discussed in a second article, to be published in a subsequent issue of In Practice.
Semidiscrete biomass dynamic modeling: an improved approach for assessing fish stock responses to pulsed harvest events
Authors: Colvin Michael E. , Pierce Clay L. , Stewart Timothy W.
Published: October 2012

Continuous harvest over an annual period is a common assumption of continuous biomass dynamics models (CBDMs); however, fish are frequently harvested in a discrete manner. We developed semidiscrete biomass dynamics models (SDBDMs) that allow discrete harvest events and evaluated differences between CBDMs and SDBDMs using an equilibrium yield analysis with varying levels of fishing mortality (F). Equilibrium fishery yields for CBDMs and SDBDMS were similar at low fishing mortalities and diverged as F approached and exceeded maximum sustained yield (FMSY). Discrete harvest resulted in lower equilibrium yields at high levels of F relative to continuous harvest. The effect of applying harvest continuously when it was in fact discrete was evaluated by fitting CBDMs and SDBDMs to time series data generated from a hypothetical fish stock undergoing discrete harvest and evaluating parameter estimates bias. Violating the assumption of continuous harvest resulted in biased parameter estimates for CBDM while SDBDM parameter estimates were unbiased. Biased parameter estimates resulted in biased biological reference points derived from CBDMs. Semidiscrete BDMs outperformed continuous BDMs and should be used when harvest is discrete, when the time and magnitude of harvest are known, and when F is greater than FMSY.
Larval fish in troubled waters — is the behavioural response of larval fish to hydrodynamic impacts active or passive?
Authors: Stoll Stefan , Beeck Peter
Published: October 2012

In a mesocosm experiment, we tested whether larval fish show an active behavioural response to hydrodynamic impacts. Exposing 1- to 3-week-old allis shad ( Alosa alosa ) larvae to a pulsed wave regime, we found that already 1-week-old larvae immediately adapt their microhabitat use and activity patterns at the onset of the wave pulses. The fish larvae instantaneously increased their activity level and moved downwards, concentrating in the calmer lower third of the water column. Within 4 min after the end of the wave pulse, the fish returned to their former distribution. Two- and 3-week-old fish larvae foraged close to the bottom substratum during calm periods but avoided this zone during the wave pulses. Thus, larval fish show an active response to hydrodynamic impacts. With the ability to adjust microhabitat use and activity level, already fish larvae are able to trade costs and benefits associated with spatio-temporal hydrodynamic heterogeneity. In particular, fish larvae should be able to minimize some of the harmful effects of navigation-induced waves where calmer evasion habitats are available.
Leaf quality influences invertebrate colonization and drift in a temperate rainforest stream
Authors: García Liliana , Richardson John S. , Pardo Isabel
Published: October 2012

Changes in riparian forest composition and diversity, such as plantations of exotic species, may alter resource quality, detritivore assemblages, and litter breakdown rates in streams. We hypothesized that different litter resources may influence colonization and drift of invertebrates inhabiting small, temperate rainforest streams in southwestern British Columbia, Canada. Leaves of different quality and origin were incubated in stream-side channels to test this hypothesis. The sequence of leaf decomposition rates was as follows: alder > alder + cedar > cedar ≥ eucalyptus. Cedar litter decayed faster when mixed with alder than when alone. Invertebrates colonizing leaf bags were predominantly collector–gatherers and shredders, particularly on alder leaves. Drift density varied over the incubation period and seemed to be controlled by leaf quality, since there were more individuals drifting from channels with alder leaves than from channels with cedar or eucalyptus. However, we observed different species-specific invertebrate responses controlled by leaf traits, particularly by numerically dominant chironomid species. Indeed, invertebrate drift from channels incubated with alder bags was mostly due to pupation and emergence of orthoclad midges, whereas this was not observed in the other channels. This differential response in colonization and drift has the potential to modify the transfer rates of organic matter to higher trophic levels and thus ecosystem functioning.
Advancing the application of the ideal free distribution to spatial models of fishing effort: the isodar approach
Authors: Gillis D.M. , van der Lee A.
Published: October 2012

The ideal free distribution (IFD) of behavioral ecology has been used in the study of the distribution of fishing effort since the 1990s. Concurrently, evolutionary perspectives on forager distributions have led to the development of theoretical curves of equal fitness, named isodars, to test IFD hypotheses. We develop isodars, based upon catch rates and unknown costs, to quantify regularity in the distribution of fishing effort among alternative areas. Our analyses indicate that these isodars provide significantly better predictions than a simple IFD without costs. Autocorrelation in the catch and effort data necessitates the use of generalized linear least squares when estimating model parameters. Differences in costs that are proportional to effort are more clearly identified in the model than nonlinear effects, which may arise from extreme interference competition. The isodar approach provides a new tool for examining the spatial dynamics of catch and effort data. It improves the accuracy of predictions and provides new parameters related to costs and vessel interactions that can be applied to rapidly identify situations where effort dynamics have changed.
The bioenergetics of density-dependent growth in Arctic char (Salvelinus alpinus)
Authors: Guénard Guillaume , Boisclair Daniel , Ugedal Ola , Forseth Torbjørn , Fleming Ian A. , Jonsson Bror
Published: October 2012

We explored the mechanisms of density-dependent growth in Arctic char ( Salvelinus alpinus ) by comparing the energetics of growth, consumption, and activity obtained under three replicated density treatments in a large-scale enclosure (90 m2surface area) experiment. The enclosures permitted the entry of zooplankton and allowed char to feed on the bottom and at the surface of the lake. We found a negative (power) relationship between growth and density. Char consumption rate decreased linearly with increasing density. Growth efficiency was affected by fish density in a similar manner as growth rate. Finally, activity increased with fish density and was particularly high at high densities. Our findings illustrate the complexity of the relationships among consumption, activity, growth rates, and fish density and bring further evidence to the possible involvement of behavioural mechanisms in density-dependent processes, notably by modulating activity costs with density.
NOISE-BASED LOGIC: WHY NOISE? A COMPARATIVE STUDY OF THE NECESSITY OF RANDOMNESS OUT OF ORTHOGONALITY
Authors: WEN HE , KISH LASZLO B.
Published: October 2012

Although noise-based logic shows potential advantages of reduced power dissipation and the ability of large parallel operations with low hardware and time complexity the question still persist: Is randomness really needed out of orthogonality? In this Letter, after some general thermodynamical considerations, we show relevant examples where we compare the computational complexity of logic systems based on orthogonal noise and sinusoidal signals, respectively. The conclusion is that in certain special-purpose applications noise-based logic is exponentially better than its sinusoidal version: Its computational complexity can be exponentially smaller to perform the same task.
ANALYSIS OF MNLMS AND KLMS ALGORITHM FOR UNDERWATER ACOUSTIC COMMUNICATIONS
Authors: MURUGAN S. SAKTHIVEL , NATARAJAN V. , RADHA S.
Published: October 2012

The use of adaptive filters to alleviate the degradation caused by wind driven ambient noise in shallow water is considered in this paper. Since, underwater acoustic signals are greatly affected by the ocean interference and ambient noise disturbances when propagating through underwater channels, an effective adaptive filtering system is necessary for denoising the signal which are degraded by noise. Least mean square (LMS), normalized LMS (NLMS), Modified New LMS (MNLMS) and Kalman LMS (KLMS) based adaptive algorithms are analyzed in terms of their performance with the aid of performance measure characteristics such as signal to noise ratio (SNR) and mean square error (MSE). The MNLMS is developed by calculating an optimum learning parameter that best suits for the acoustic signal used. The analysis is carried out for a range of 100 Hz to 10 KHz source signals and the algorithm proves that any ambient noise signals against the source signal in this range can be eliminated and the source signal can be reconstructed. Our simulation results show that KLMS and MNLMS algorithms achieve remarkable performance even in the very low SNR region as compared to LMS and NMLS algorithms. Moreover, it is observed that the output convergence is also very fast for MNLMS and KLMS.
A New Floating-Probe for Measurement of Insulated Plasma Produced by Radio-Frequency Power
Authors: Taniuchi Yasuyuki , Yamada Toshinori , Tokieda Takanori , Utsumi Michiaki , Isomura Masao , Shindo Haruo
Published: October 2012

The paper provides a new probe method which enables us to measure parameters of plasmas produced in insulated vessel. In particular, the measurements of electron temperature and density are all made in floating condition of probe, so that there is no need to draw net current from plasma. The method is based on measurement of the functional relationship between the floating potential and the heating voltage of emissive probe. In the first place, the measured parameters of plasma produced in the metal vessel are shown, demonstrating how a new probe works. In the second place, the measurement in the quartz discharge tube is shown, and the measured data by the present method are compared with those obtained by the conventional double probe, demonstrating that they are consistent. It is emphasized that the present new method is a first success in floating probe to be able to measure all plasma parameters.
Measurement of a Balanced Receiver's Skew Using Optoelectronic Interferometry
Authors: Choe Joong-Seon , Youn Chun Ju , Kim Jong-Hoi , Choi Kwang-Seong , Kim Duk Jun , Kwon Yong-Hwan , Nam Eun Soo
Published: October 2012

Skew is an important parameter of a balanced receiver that has significant influence upon its performance, and should be kept as small as possible. To measure small skew in time domain requires advanced equipments such as short pulse laser and wide bandwidth oscilloscope. Presented is a simple method for measuring skew of a balanced receiver using conventional bandwidth measurement setup with beam splitter. By adding skew to the output of the beam splitter, small skew of a balanced receiver can be obtained easily.
The Ethics of Tracking
Authors: Neal Lisa
Published: October 2012

If students are treated responsibly and ethically then they can better focus on learning.
Who Would Want to Cheat in an Online Course? Ask Dilbert
Authors: Neal Lisa
Published: October 2012

Even in targeted education, there will always be violators for whom intrinsic motivation and the joy of learning are not enough: Some will always want the good grade without putting in the time and effort.
The Meaning of Maintenance
Authors: Neville-Neil George V.
Published: October 2012

Isn’t
software maintenance
a misnomer? I’ve never heard of anyone reviewing a piece of code every year, just to make sure it was still in good shape. It seems like software maintenance is really just a cover for bug fixing. When I think of maintenance I think of taking my car in for an oil change, not fixing a piece of code. Are there any people who actually review code after it has been running in a production environment?
Making Sense of Revision-control Systems
Authors: O'Sullivan Bryan
Published: October 2012

Modern software is tremendously complicated, and the methods that teams use to manage its development reflect this complexity. Though many organizations use revision-control software to track and manage the complexity of a project as it evolves, the topic of how to make an informed choice of revision-control tools has received scant attention. Until fairly recently, the world of revision control was moribund, so there was simply not much to say on this subject.
Four Billion Little Brothers? Privacy, mobile phones, and ubiquitous data collection
Authors: Shilton Katie
Published: October 2012

They place calls, surf the Internet, and there are close to 4 billion of them in the world. Their built-in microphones, cameras, and location awareness can collect images, sound, and GPS data. Beyond chatting and texting, these features could make phones ubiquitous, familiar tools for quantifying personal patterns and habits. They could also be platforms for thousands to document a neighborhood, gather evidence to make a case, or study mobility and health. This data could help you understand your daily carbon footprint, exposure to air pollution, exercise habits, and frequency of interactions with family and friends.
Trojan horse inside?
Authors: Zeichick Alan
Published: October 2012

Sleeper kill switches may lurk in military systems and networks.
All together now
Authors: Treese Win
Published: October 2012

If you're saying it to one, you might be saying it to all.
Learn without the web
Authors: Bauerlein Mark
Published: October 2012

Teach that the research process is as worthwhile as the sought-after information itself.
Analytical and experimental comparison of six algorithms for the vertex cover problem
Authors: Delbot François , Laforest Christian
Published: October 2012

The vertex cover is a well-known NP-complete minimization problem in graphs that has received a lot of attention these last decades. Many algorithms have been proposed to construct vertex cover in different contexts (offline, online, list algorithms, etc.) leading to solutions of different level of quality. This quality is traditionally measured in terms of approximation ratio, that is, the worst possible ratio between the quality of the solution constructed and the optimal one. For the vertex cover problem the range of such known ratios are between 2 (conjectured as being the smallest constant ratio) and Δ, the maximum degree of the graph. Based on this measure of quality, the hierarchy is almost clear (the smaller the ratio is, the better the algorithm is).

In this article, we show that this measure, although of great importance, is too macroscopic and does not reflect the practical behavior of the methods. We prove this by analyzing (known and recent) algorithms running on a particular class of graphs: the paths. We obtain closed and exact formulas for the mean of the sizes of vertex cover constructed by these different algorithms. Then, we assess their quality experimentally in several well-chosen class of graphs (random, regular, trees, BHOSLIB benchmarks, trap graphs, etc.). The synthesis of all these results lead us to formulate a “practical hierarchy” of the algorithms. We remark that it is, more or less, the opposite to the one only based on approximation ratios, showing that worst-case analysis only gives partial information on the quality of an algorithm.
Bit-vector algorithms for binary constraint satisfaction and subgraph isomorphism
Authors: Ullmann Julian R.
Published: October 2012

A solution to a binary constraint satisfaction problem is a set of discrete values, one in each of a given set of domains, subject to constraints that allow only prescribed pairs of values in specified pairs of domains. Solutions are sought by backtrack search interleaved with a process that removes from domains those values that are currently inconsistent with provisional choices already made in the course of search. For each value in a given domain, a bit-vector shows which values in another domain are or are not permitted in a solution. Bit-vector representation of constraints allows bit-parallel, therefore fast, operations for editing domains during search. This article revises and updates bit-vector algorithms published in the 1970's, and introduces focus search, which is a new bit-vector algorithm relying more on search and less on domain-editing than previous algorithms. Focus search is competitive within a limited family of constraint satisfaction problems.

Determination of subgraph isomorphism is a specialized binary constraint satisfaction problem for which bit-vector algorithms have been widely used since the 1980s, particularly for matching molecular structures. This article very substantially updates the author's 1976 subgraph isomorphism algorithm, and reports experimental results with random and real-life data.
The role of network trace anonymization under attack
Authors: Burkhart Martin , Schatzmann Dominik , Trammell Brian , Boschi Elisa , Plattner Bernhard
Published: October 2012

In recent years, academic literature has analyzed many attacks on network trace anonymization techniques. These attacks usually correlate external information with anonymized data and successfully de-anonymize objects with distinctive signatures. However, analyses of these attacks still underestimate the real risk of publishing anonymized data, as the most powerful attack against anonymization is traffic injection. We demonstrate that performing live traffic injection attacks against anonymization on a backbone network is not difficult, and that potential countermeasures against these attacks, such as traffic aggregation, randomization or field generalization, are not particularly effective. We then discuss tradeoffs of the attacker and defender in the so-called injection attack space. An asymmetry in the attack space significantly increases the chance of a successful de-anonymization through lengthening the injected traffic pattern. This leads us to re-examine the role of network data anonymization. We recommend a unified approach to data sharing, which uses anonymization as a part of a technical, legal, and social approach to data protection in the research and operations communities.
Internet requests for comments (RFCs) as scholarly publications
Authors: Carpenter Brian E. , Partridge Craig
Published: October 2012

This note describes the various peer review processes applied to Internet Requests for Comments (RFCs) over a number of years, and suggests that these have been up to normal scholarly standards since at least 1992. The authors believe that these documents should be considered the equivalent of scholarly publications.
"Publish or Perish" in the Internet Age
Authors: Chiu Dah Ming , Fu Tom Z.J.
Published: October 2012

This study takes papers from a selected set of computer networking conferences and journals spanning the past twenty years (1989-2008) to produce various statistics to show how our community publishes papers, and how this process is changing over the years. We observe the rapid growth in the rate of publications, venues, citations, authors, and number of co-authors. We explain how these quantities are related, in particular explore how they are related over time and the reasons behind the changes. The widely accepted model to explain the power law distribution of paper citations is "preferential attachment". We propose an extension and refinement that suggests "elapsed time" is also a factor to determine which papers get cited. We try to compare the selected venues based on citation count, and discuss how we might think about these comparisons, in terms of the roles played by different venues, and the ability to predict impact by venues, and citation counts. The treatment of these issues is general and can be applied to study publication patterns in other research communities. The larger goal of this study is to generate discussion about our publication system, and work towards a vision to transform our publication system for better scalability and effectiveness.
Rapid service creation using the JUNOS SDK
Authors: Kelly James , Araujo Wladimir , Banerjee Kallol
Published: October 2012

The creation of services on IP networks is a lengthy process. The development time is further increased if this involves the equipment manufacturer adding third-party technology in their product. In this work we describe how the JUNOS SDK (part of Juniper Networks Partner Solution Development Platform) facilitates innovation and can be used to considerably shorten the development cycle for the creation of services based on embedding third-party software into Juniper Networks routers. We describe how the JUNOS SDK exposes programmatic interfaces to enable packet manipulation by third-party software and how it can be used as a common platform for deploying unique services through the combination of multiple components from multiple parties.
Enhancing dynamic cloud-based services using network virtualization
Authors: Hao Fang , Lakshman T. V. , Mukherjee Sarit , Song Haoyu
Published: October 2012

It is envisaged that services and applications will migrate to a cloud-computing paradigm where thin-clients on user-devices access, over the network, applications hosted in data centers by application service providers. Examples are cloud-based gaming applications and cloud-supported virtual desktops. For good performance and efficiency, it is critical that these services are delivered from locations that are the best for the current (dynamically changing) set of users. To achieve this, we expect that services will be hosted on virtual machines in interconnected data centers and that these virtual machines will migrate dynamically to locations best-suited for the current user population. A basic network infrastructure need then is the ability to migrate virtual machines across multiple networks without losing service continuity. In this paper, we develop mechanisms to accomplish this using a network-virtualization architecture that relies on a set of distributed forwarding elements with centralized control (borrowing on several recent proposals in a similar vein). We describe a preliminary prototype system, built using Openflow components, that demonstrates the feasibility of this architecture in enabling seamless migration of virtual machines and in enhancing delivery of

cloud-based services.
Remote network labs
Authors: Liu Huan , Orban Dan
Published: October 2012

Network equipment is difficult to configure correctly. To minimize configuration errors, network administrators typically build a smaller scale test lab replicating the production network and test out their configuration changes before rolling out the changes to production. Unfortunately, building a test lab is expensive and the test equipment is rarely utilized. In this paper, we present Remote Network Labs, which is aimed at leveraging the expensive network equipment more efficiently and reducing the cost of building a test lab. Similar to a server cloud such as Amazon EC2, a user could request network equipment remotely and connect them through a GUI or web services interface. The network equipment is geographically distributed, allowing us to reuse test equipment anywhere. Beyond saving costs, Remote Network Labs brings about many additional benefits, including the ability to fully automate network configuration testing.
Apprehending joule thieves with cinder
Authors: Rumble Stephen M. , Stutsman Ryan , Levis Philip , Mazières David , Zeldovich Nickolai
Published: October 2012

Energy is the critical limiting resource to mobile computing devices. Correspondingly, an operating system must track, provision, and ration how applications consume energy. The emergence of third-party application stores and marketplaces makes this concern even more pressing. A third-party application must not deny service through excessive, unforeseen energy expenditure, whether accidental or malicious. Previous research has shown promise in tracking energy usage and rationing it to meet device lifetime goals, but such mechanisms and policies are still nascent, especially regarding user interaction.

We argue for a new operating system, called Cinder, which builds on top of the HiStar OS. Cinder's energy awareness is based on hierarchical capacitors and task profiles. We introduce and explore these abstractions, paying particular attention to the ways in which policies could be generated and enforced in a dynamic system.
On the leakage of personally identifiable information via online social networks
Authors: Krishnamurthy Balachander , Wills Craig E.
Published: October 2012

For purposes of this paper, we define "Personally identifiable information" (PII) as information which can be used to distinguish or trace an individual's identity either alone or when combined with other information that is linkable to a specific individual. The popularity of Online Social Networks (OSN) has accelerated the appearance of vast amounts of personal information on the Internet. Our research shows that it is possible for third-parties to link PII, which is leaked via OSNs, with user actions both within OSN sites and elsewhere on non-OSN sites. We refer to this ability to link PII and combine it with other information as "leakage". We have identified multiple ways by which such leakage occurs and discuss measures to prevent it.
Characterising temporal distance and reachability in mobile and online social networks
Authors: Tang John , Musolesi Mirco , Mascolo Cecilia , Latora Vito
Published: October 2012

The analysis of social and technological networks has attracted a lot of attention as social networking applications and mobile sensing devices have given us a wealth of real data. Classic studies looked at analysing static or aggregated networks, i.e., networks that do not change over time or built as the results of aggregation of information over a certain period of time. Given the soaring collections of measurements related to very large, real network traces, researchers are quickly starting to realise that connections are inherently varying over time and exhibit more dimensionality than static analysis can capture.

In this paper we propose new temporal distance metrics to quantify and compare the speed (delay) of information diffusion processes taking into account the evolution of a network from a global view. We show how these metrics are able to capture the temporal characteristics of time-varying graphs, such as delay, duration and time order of contacts (interactions), compared to the metrics used in the past on static graphs. We also characterise network reachability with the concepts of in- and out-components. Then, we generalise them with a global perspective by defining temporal connected components. As a proof of concept we apply these techniques to two classes of time-varying networks, namely connectivity of mobile devices and interactions on an online social network.
A platform for high performance and flexible virtual routers on commodity hardware
Authors: Egi Norbert , Greenhalgh Adam , Handley Mark , Hoerdt Mickael , Huici Felipe , Mathy Laurent , Papadimitriou Panagiotis
Published: October 2012

Multi-core CPUs, along with recent advances in memory and buses, render commodity hardware a strong candidate for software router virtualization. In this context, we present the design of a new platform for virtual routers on modern PC hardware. We further discuss our design choices in order to achieve both high performance and flexibility for packet processing.
A theoretical framework of component-based software development phases
Authors: Sharp Jason H. , Ryan Sherry D.
Published: October 2012

Component-Based Software Development (CBSD) is considered by many as the next revolution in systems development. Its focus is on the integration of pre-fabricated software components to build systems that increase portability and flexibility. CBSD purports to address the problem of systems which are delivered behind schedule, over-budget, and inadequately meeting user requirements. A major contribution of this work is providing a solid theoretical foundation using Simon's (1977) problem solving model and the tenets of design science to the emerging CBSD paradigm which has lacked a theoretical-base. In doing so, we construct a theoretical framework of the CBSD development phases by synthesizing the current CBSD related literature and developing propositions for guiding future research. This framework clearly differentiates between component and systems development in the CBSD approach. Implications for both research and practice are also discussed.
Using GPCE principles for hardware systems and accelerators
Authors: Nikhil Rishiyur S.
Published: October 2012

Moore's Law has precipitated a crisis in the creation of hardware systems (ASICs and FPGAs)-how to design such enormously complex concurrent systems quickly, reliably and affordably? At the same time, portable devices, the energy crisis, and high performance computing present a related challenge-how to move complex and high-performance algorithms from software into hardware (for more speed and/or energy efficiency)?

In this talk I will start with a brief technical introduction to BSV, a language that directly addresses these concerns. It uses ideas from Guarded Atomic Actions (cf. Term Rewriting Systems, TLA+, Unity, and EventB) to address complex concurrency with scalability. It borrows from Haskell (types, type classes, higher-order functions) for robustness and powerful program generation (a.k.a. "static elaboration" to HW designers). And it is fully synthesizable (compilable) into high-quality RTL (Verilog/VHDL). I will then describe some of the remarkable projects that BSV has enabled in industry and academia today.
The axioms strike back
Authors: Bagge Anya Helene , David Valentin , Haveraaen Magne
Published: October 2012

Modern development practises encourage extensive testing of code while it is still under development, using unit tests to check individual code units in isolation. Such tests are typically case-based, checking a likely error scenario or an error that has previously been identified and fixed. Coming up with good test cases is challenging, and focusing on individual tests can distract from creating tests that cover the full functionality.

Axioms, known from program specification, allow for an alternative way of generating test cases, where the intended functionality is described as rules or equations that can be checked automatically. Axioms are proposed as part of the
concept
feature of the upcoming C++0x standard.

In this paper, we describe how tests may be generated automatically from axioms in C++ concepts, and supplied with appropriate test data to form effective automated unit tests.
Transactional pointcuts
Authors: Sadat-Mohtasham Hossein , Hoover H. James
Published: October 2012

Aspect-oriented mechanisms are characterized by their join point models. A join point model has three components: join points, which are elements of language semantics; "a means of identifying join points"; and "a means of affecting the behaviour at those join points." A pointcut-advice model is a dynamic join point model in which join points are points in program execution. Pointcuts select a set of join points, and advice affects the behaviour of the selected join points. In this model, join points are typically selected and advised independently of each other. That is, the relationships between join points are not taken into account in join point selection and advice. In practice, join points are often not independent. Instead, they form part of a higher-level operation that implements the intent of the developer (
e.g.
managing a resource). There are natural situations in which join points should be selected only if they play a specific role in that operation.

We propose a new join point model that takes join point interrelationships into account and allows the designation of more complex computations as join points. Based on the new model, we have designed an aspect-oriented construct called a
transactional pointcut (transcut)
. Transcuts select sets of interrelated join points and reify them into higher-level join points that can be advised. They share much of the machinery and intuition of pointcuts, and can be viewed as their natural extension. We have implemented a transcuts prototype as an extension to the AspectJ language and integrated it into the abc compiler. We present an example where a transcut is applied to implement recommended resource handling practices in the presence of exceptions within method boundaries.
Classifying Java class transformations for pervasive virtualized access
Authors: McGachey Phil , Hosking Antony L. , Moss J. Eliot B.
Published: October 2012

The indirection of object accesses is a common theme for target domains as diverse as transparent distribution, persistence, and program instrumentation. Virtualizing accesses to fields and methods (by redirecting calls through accessor and indirection methods) allows interposition of arbitrary code, extending the functionality of an application beyond that intended by the original developer.

We present class modifications performed by our RuggedJ transparent distribution platform for standard Java virtual machines. RuggedJ abstracts over the location of objects by implementing a single object model for local and remote objects. However the implementation of this model is complicated by the presence of native and system code; classes loaded by Java's bootstrap class loader can be rewritten only in a limited manner, and so cannot be modified to conform to RuggedJ's complex object model. We observe that system code comprises the majority of a given Java application: an average of 76% in the applications we study. We consider the constraints imposed upon pervasive class transformation within Java, and present a framework for systematically rewriting arbitrary applications. Our system accommodates all system classes, allowing both user and system classes alike to be referenced using a single object model.
Generating safe template languages
Authors: Heidenreich Florian , Johannes Jendrik , Seifert Mirko , Wende Christian , Böhme Marcel
Published: October 2012

Template languages are widely used within generative programming, because they provide intuitive means to generate software artefacts expressed in a specific object language. However, most template languages perform template instantiation on the level of string literals, which allows neither syntax checks nor semantics analysis. To make sure that generated artefacts always conform to the object language, we propose to perform static analysis at template design time. In addition, the increasing popularity of domainspecific languages (DSLs) demands an approach that allows to reuse both the concepts of template languages and the corresponding tools.

In this paper we address the issues mentioned above by presenting how existing languages can be automatically extended with generic template concepts (e.g., placeholders, loops, conditions) to obtain safe template languages. These languages provide means for syntax checking and static semantic analysis w.r.t. the object language at template design time. We discuss the prerequisites for this extension, analyse the types of correctness properties that can be assured at template design time, and exemplify the key benefits of this approach on a textual DSL and Java.
Generating execution infrastructures for component-oriented specifications with a model driven toolchain
Authors: Radermacher Ansgar , Cuccuru Arnaud , Gerard Sebastien , Terrier François
Published: October 2012

The development of embedded Systems becomes more and more complex. Model driven engineering can help to manage this complexity by specifying real-time properties in a declarative way and automating the deployment. The UML profile MARTE is a OMG standard that allows to model real-time properties. However, there is no execution infrastructure that supports MARTE's generic component model (GCM) and the application modeling (HLAM).

The contribution of the paper is twofold: it presents a proposition of a component model with flexible interaction support that allows to tailor code generation to domain and target requirements. Second, it will show how MARTE's GCM concepts can be implemented by means of the proposed component model. The proposed component model has been largely developed in the context of the French national project Flex-eWare with the intention to unify major components model, notably the CORBA component model (CCM) and Fractal. The paper explains the major elements of this model in detail and shows how specific connector and containers can implement MARTE specifications. We present the tool support that is integrated into a UML modeler and based on model-to-model and model to text transformations.
Safe composition of non-monotonic features
Authors: Kuhlemann Martin , Batory Don , Kästner Christian
Published: October 2012

Programs can be composed from features. We want to verify automatically that all legal combinations of features can be composed safely without errors. Prior work on this problem assumed that features add code monotonically. We generalize prior work to enable features to add
and remove
code, describe our analyses and implementation, and review case studies. We observe that more expressive features increase the complexity of developed programs rapidly -- up to the point where tools and automated concepts as presented in this paper are indispensable for verification.
Is hardware innovation over?
Authors: Arvind Professor
Published: October 2012

My colleagues, promotion committees, research funding agencies and business people often wonder if there is need for any architecture research. There seems to be no room to dislodge Intel IA-32. Even the number of new Application-Specific Integrated Circuits (ASICs) seems to be declining each year, because of the ever-increasing development cost.

This viewpoint ignores another reality which is that the future will be dominated by mobile devices such as smart phones and the infrastructure needed to support consumer services on these devices. This is already restructuring the IT industry. To the first-order, in the mobile world functionality is determined by what can be supported within a 3W power budget. The only way to reduce power by one to two orders of magnitude is via functionally specialized hardware blocks. A fundamental shift is needed in the current design flow of systems-on-a-chip (SoCs) to produce them in a less-risky and cost-effective manner.

In this talk we will present, via examples, a method of designing systems that facilitates the synthesis of complex SoCs from reusable "IP" modules. The technical challenge is to provide a method for connecting modules in a parallel setting so that the functionality and the performance of the composite are predictable.
GAMBIT
Authors: Coons Katherine E. , Burckhardt Sebastian , Musuvathi Madanlal
Published: October 2012

As concurrent programming becomes prevalent, software providers are investing in concurrency libraries to improve programmer productivity. Concurrency libraries improve productivity by hiding error-prone, low-level synchronization from programmers and providing higher-level concurrent abstractions. Testing such libraries is difficult, however, because concurrency failures often manifest only under particular scheduling circumstances. Current best testing practices are often inadequate: heuristic-guided fuzzing is not systematic, systematic schedule enumeration does not find bugs quickly, and stress testing is neither systematic nor fast.

To address these shortcomings, we propose a prioritized search technique called GAMBIT that combines the speed benefits of heuristic-guided fuzzing with the soundness, progress, and reproducibility guarantees of stateless model checking. GAMBIT combines known techniques such as partial-order reduction and preemption-bounding with a generalized best-first search frame- work that prioritizes schedules likely to expose bugs. We evaluate GAMBIT's effectiveness on newly released concurrency libraries for Microsoft's .NET framework. Our experiments show that GAMBIT finds bugs more quickly than prior stateless model checking techniques without compromising coverage guarantees or reproducibility.
Featherweight X10
Authors: Lee Jonathan K. , Palsberg Jens
Published: October 2012

We present a core calculus with two of X10's key constructs for parallelism, namely async and finish. Our calculus forms a convenient basis for type systems and static analyses for languages with async-finish parallelism, and for tractable proofs of correctness. For example, we give a short proof of the deadlock-freedom theorem of Saraswat and Jagadeesan. Our main contribution is a type system that solves the open problem of context-sensitive may-happen-in-parallel analysis for languages with async-finish parallelism. We prove the correctness of our type system and we report experimental results of performing type inference on 13,000 lines of X10 code. Our analysis runs in polynomial time, takes a total of 28 seconds on our benchmarks, and produces a low number of false positives, which suggests that our analysis is a good basis for other analyses such as race detectors.
Compiler aided selective lock assignment for improving the performance of software transactional memory
Authors: Mannarswamy Sandya , Chakrabarti Dhruva R. , Rajan Kaushik , Saraswati Sujoy
Published: October 2012

Atomic sections have been recently introduced as a language construct to improve the programmability of concurrent software. They simplify programming by not requiring the explicit specification of locks for shared data. Typically atomic sections are supported in software either through the use of optimistic concurrency by using transactional memory or through the use of pessimistic concurrency using compiler-assigned locks. As a software transactional memory (STM) system does not take advantage of the specific memory access patterns of an application it often suffers from false conflicts and high validation overheads. On the other hand, the compiler usually ends up assigning coarse grain locks as it relies on whole program points-to analysis which is conservative by nature. This adversely affects performance by limiting concurrency. In order to mitigate the disadvantages associated with STM's lock assignment scheme, we propose a hybrid approach which combines STM's lock assignment with a compiler aided selective lock assignment scheme (referred to as SCLA-STM). SCLA-STM overcomes the inefficiencies associated with a purely compile-time lock assignment approach by (i) using the underlying STM for shared variables where only a conservative analysis is possible by the compiler (e.g., in the presence of may-alias points to information) and (ii) being selective about the shared data chosen for the compiler-aided lock assignment. We describe our prototype SCLA-STM scheme implemented in the hp-ux IA-64 C/C++ compiler, using TL2 as our STM implementation. We show that SCLA-STM improves application performance for certain STAMP benchmarks from 1.68% to 37.13%.