Cluster Grid based Response-time analysis module for the PIPE Tool.

Generalized Stochastic Petri Nets (GSPNs) are a widely used high-level formalism used for modelling discrete-event systems. The Platform Independent Petri net Editor (PIPE) is an open source software project that allows creation, analysis and simulation of Petri Nets. This tool paper presents a PIPE module for response-time analysis of a Petri net’s underlying Continuous Time Markov Chain (CTMC). Jobs are submitted via a web interface, from within PIPE or from a browser. The parallel computations are run using Grid Engine on a cluster hosted at Imperial College London. 1

Exploration of the network spun by website users

Using data stretching over more than 5 years for the website http://gallery.future-i.com/ this paper investigates basic properties of the popularity of pictures and the way users navigate through the website. We find that the rank frequency plot of the downloaded pictures follows a Zipf law. The download rate of individual popular pictures over time resembles that seen of infection rates of diseases. The graph created by successive downloads of pictures shows a power law that does not change over different time periods. We discuss how our findings can be modelled and how they are of importance to website performance

Radical nostalgia, progressive patriotism and Labour's 'English problem'

‘Progressive patriots’ have long argued that Englishness can form the basis of a transformative political project, whether based on an historic tradition of resistance to state power or an open and cosmopolitan identity. However, this article suggests that the politics of Englishness present a number of specific dilemmas for Labour. First the historical narrative of a radical tradition in British history is not straightforwardly English and cannot easily be used to support a competitive politics of nationhood, in the way that disaffected English identifiers might desire. Second, the deliberately alternative nature of this ‘radical nostalgic’ narrative makes it an unlikely basis for a unifying national story. It is also at odds with Labour’s status as a successful party of government, committed to using the power of the British state, rather than opposing it. Finally, while ‘everyday Englishness’ may well align with core Labour values and be less socially conservative, intolerant or racially exclusive than it is often described, its very nature as an everyday practice, rather than a political identity makes it difficult for Labour to co-opt

Location-Aware Quality of Service Measurements for Service-Level Agreements

We add specifications of location-aware measurements to performance models in a compositional fashion, promoting precision in performance measurement design. Using immediate actions to send control signals between measurement components we are able to obtain more accurate measurements from our stochastic models without disturbing their structure. A software tool processes both the model and the measurement specifications to give response time distributions and quantiles, an essential calculation in determining satisfaction of service-level agreements (SLAs)

How Synchronisation Strategy Approximation in PEPA Implementations Affects Passage Time Performance Results

Abstract. Passage time densities are useful performance measurements in stochastic systems. With them the modeller can extract probabilistic quality-of-service guarantees such as: the probability that the time taken for a network header packet to travel across a heterogeneous network is less than 10ms must be at least 0.95. In this paper, we show how new tools can extract passage time densities and distributions from stochastic models defined in PEPA, a stochastic process algebra. In stochastic process algebras, the synchronisation policy is important for defining how different system components interact. We also show how these passage time results can vary according to which synchronisation strategy is used. We compare results from two popular strategies.

A clinical study of external ear reconstruction: a study of 20 cases

Background: Auricular defects pose one of the most difficult challenges in reconstructive surgery of the head and neck. The reason is the unique three-dimensional anatomical architecture of the auricle, with its multiple concavities and convolutions of the cartilage and the thin, delicate skin cover. Acquired auricular deformities commonly result from traumatic injuries, burn trauma or tumour extirpation. These vary in severity from simple lacerations to complete auricular avulsions. Congenital ear deformity (microtia) occurs in every 1 out of 6000 live births. The goal of reconstruction is the precise duplication of the missing anatomical part with regard to size, orientation and anatomical landmarks.Methods: Range from healing by secondary intention to complete replacement with autologous rib cartilage and/or auricular prosthesis. Total auricular reconstruction was done by two methods: (1) Nagata and (2) Brent’s method. Nagata’s technique is commonly performed in this study. The present study aimed to evaluate the reconstruction of auricular defects using autologous rib cartilage graft with or without temperoparietal fascia flap covered by split-thickness skin graft.Results: Excellent cosmetic result can be obtained with adequate skills and training in carving the cartilage for auricular framework. This improves confidence and gives psychological support to microtia patients.Conclusions: With training and method, results in ear reconstruction using autologous rib cartilage are excellent and reproducible.</jats:p

24th UK performance engineering workshop

Departmental Technical Report: 08/

An Insight from Organizing CLImbing for CLImate GEOspatial School (CLIGEOS-2024) in Mountainous Regions

This paper delves into the multifaceted experiences and insights garnered from organizing a short-term training programme aimed at professionals, students, academics, and climate enthusiasts. The programme, named CLImbing for CLImate GEOspatial School (CLIGEOS-2024), was a collaborative effort by the International Society of Photogrammetry and Remote Sensing (ISPRS) and ISPRS Student Consortium (ISPRS-SC) alongside Center for space science and geomatics studies (CSSGS) Pashchimanchal campus, Institute of Engineering, Tribhuvan University, Nepal, Universita&rsquo; Degli Studi Di Udine, Italy and LJ University, India aimed at addressing environmental challenges, particularly in hill and mountain regions. Despite facing logistical and communication hurdles due to the geographical dispersion of organizing institutions, the event successfully brought together participants with backgrounds in GIS, remote sensing, agriculture, and forestry. The programme was structured to promote participatory learning and project-based learning methodologies, incorporating classroom teaching, hands-on activities, fieldwork, data collection, short projects, quizzes, and evaluation mechanisms. Through a meticulously planned sequence, participants engaged in theoretical lectures, practical sessions on drone technology, industry expert presentations, and a mountain trek to observe climate change phenomena first-hand. Despite challenges related to infrastructure, including limited internet connectivity and access to data, the programme served as a catalyst for raising awareness about climate change and promoting sustainable practices. Key takeaways highlighted the importance of spatial data analysis, interdisciplinary collaboration, and hands-on learning in advancing solutions for sustainable development. The paper concludes with lessons learned from the programme, providing insights for future initiatives aimed at capacity building and knowledge dissemination