Talk

Towards Refinement by Resolution in Dependent Type Theory – František Farka

Abstract
Dependent types are increasingly used in functional programming languages. The surface syntax of dependent types, as seen by a programmer, is elaborated by a compiler into an internal, type-theoretic representation. In order to perform this step, the compiler needs to infer a nontrivial amount of information to successfully type-check the internal representation. This process—type refinement—is complex, implementation dependent, and very few formal developments currently exist. We discuss a novel and simpler formalisation of type refinement in first order type theory with dependent types. We propose a translation of type-refinement problems to Horn-Clause logic with explicit proof-terms, using proof-relevant resolution as the type inference mechanism.

Event details

  • When: 9th November 2017 12:00 - 13:00
  • Where: Cole 1.33b
  • Format: Talk

SRG Seminar: Investigation of Virtual Network Isolation Security in Cloud Computing Using Penetration Testing by Haifa Al Nasseri

Software Defined Networking (SDN) or Virtual Networks (VNs) are required for cloud tenants to leverage demands. However, multi-tenancy can be compromised without proper isolation. Much research has been conducted into VN Isolation; many researchers are not tackling security aspects or checking if their isolation evaluation is complete. Therefore, data leakage is a major security concern in the cloud in general.

This research uses an OpenStack VN and OpenStack Tenant Network to test multi-tenancy features. We are evaluating the relationship between isolation methods used in cloud VN and the amount of data being leaked through using penetration tests. These tests will be used to identify the vulnerabilities causing cloud VN data leakage and to investigate how the vulnerabilities, and the leaked data, can compromise the tenant Virtual Networks.

Event details

  • When: 4th May 2017 13:00 - 14:00
  • Where: Cole 1.33b
  • Series: Systems Seminars Series
  • Format: Talk

Translational Research into Common Psychiatric Disorders, Professor Douglas Steele, Professor of Neuroimaging / Consultant Psychiatrist, University of Dundee

Translational Neuroimaging Based Psychiatric Research

Computational methods are having a considerable influence on contemporary neuroscience research: in data collection (non-invasive functional brain imaging), data analysis and computational modelling of healthy and abnormal brain and behaviour. The presentation is in two parts. Part 1 is an overview of the current main computational-neuroscience areas in research. Part 2 focuses on some recent high impact research into potential empirical and mechanistic biomarkers for psychiatric disorders.

Event details

  • When: 24th April 2017 14:00 - 15:00
  • Where: Cole 1.33a
  • Format: Colloquium, Seminar, Talk

Type-Driven Development of Communicating Systems using Idris

Speaker: Jan de Muijnck-Hughes

Abstract

Communicating protocols are a cornerstone of modern system design.
However, there is a disconnect between the different tooling used to design, implement and reason about these protocols and their implementations.
Session Types are a typing discipline that help resolve this difference by allowing protocol specifications to be used during type-checking to ensure that implementations adhere to a given specification.

Idris is a general purpose programming language that supports full-dependent types, providing programmers with the ability to reason more precisely about programs.
This talk introduces =Sessions=, our implementation of Session Types in Idris, and demonstrates =Sessions= ability to design and realise several common protocols.

=Sessions= improves upon existing Session Type implementations by introducing value dependencies between messages and fine-grained channel management during protocol design and implementation.
We also use Idris’ support for EDSL construction to allow for protocols to be designed and reasoned about in the same language as their implementation.
Thereby allowing for an intrinsic bond to be introduced between a protocol’s implementation and specification, and also with its verification.

Using =Sessions=, we can reduce the existing disconnect between the tooling used for protocol design, implementation, and verification.

 

 

 

Event details

  • When: 23rd February 2017 13:00 - 15:00
  • Where: Cole 1.33b
  • Format: Colloquium, Seminar, Talk

Talk: Using cost models of algorithmic skeletons

Abstract:

 The increasing importance of parallelism has motivated the creation of better abstractions for writing parallel software, including structured parallelism using nested algorithmic skeletons. Such approaches provide high-level abstractions that avoid common problems, such as race conditions, and often allow strong cost models to be defined. However, choosing a combination of algorithmic skeletons that yields good parallel speedups for a program on some specific parallel architecture remains a difficult task. In order to achieve this, it is necessary to simultaneously reason both about the costs of different parallel structures and about the semantic equivalences between them. This paper presents a new type-based mechanism that enables strong static reasoning about these properties. We exploit well-known properties of a very general recursion pattern, hylomorphisms, and give a denotational semantics for structured parallel processes in terms of these hylomorphisms. Using our approach, it is possible to determine formally whether it is possible to introduce a desired parallel structure into a program without altering its functional behaviour, and also to choose a version of that parallel structure that minimises some given cost model.

Event details

  • When: 13th December 2016 16:00 - 17:00
  • Where: Honey 103 - GFB
  • Format: Talk

Multi-modal Indoor Positioning: Trends and Challenges by Prof. Niki Trigoni, Oxford University

Abstract:

GPS has enabled a number of location based services outdoors, but the problem of localisation remains open in GPS-denied environments, such as indoors and underground. In this talk, I will discuss the key challenges to accurate and robust position estimation, and will describe a variety of sensor modalities and algorithms developed at Oxford to address this problem.

The talk will cover inertial, radio-based and vision-based localisation approaches and their advantages and disadvantages in different settings.

 

Short Bio:

Niki Trigoni is a Professor at the Oxford University Department of Computer Science and a fellow of Kellogg College. She obtained her PhD at the University of Cambridge (2001), became a postdoctoral researcher at Cornell University (2002-2004), and a Lecturer at Birkbeck College (2004-2007). Since she moved to Oxford in 2007, she established the Sensor Networks Group, and has conducted research in communication, localization and in-network processing algorithms for sensor networks. Her recent and ongoing projects span a wide variety of sensor networks applications, including indoor/underground localization, wildlife sensing, road traffic monitoring, autonomous (aerial and ground) vehicles, and sensor networks for industrial processes.

Event details

  • When: 8th November 2016 14:00 - 15:00
  • Where: Cole 1.33
  • Series: School Seminar Series
  • Format: Seminar, Talk

Quicker Sort by Dietmar Kühl, Bloomberg L.P.

 

Abstract:

Quicksort is a well-known sorting algorithm used to implement sort functionality in many libraries. The presentation isn’t really about the algorithm itself but rather about how to actually create an efficient implementation of the algorithm: a text-book implementation of the algorithm actually is not that quick (even if the pivot is chosen cleverly). It takes paying some attention to detail to improve the implementation significantly. This presentation starts with a simple implementation and makes incremental improvements to eventually yield a proper generic and fast sorting function. All code will be in C++ but it should be possible to follow the majority of the reasoning with knowledge of another programming language.

 

Short Bio:

Dietmar Kühl is a senior software developer at Bloomberg L.P. working on the data distribution environment used both internally and by enterprise installations at clients. Before joining Bloomberg he has done mainly consulting for software projects in the finance area. He is a regular attendee of the ANSI/ISO C++ standards committee, presents at conferences, and he used to be a moderator of the newsgroup comp.lang.c++.moderated. He frequently answers questions on Stackoverflow.

Event details

  • When: 25th October 2016 14:30 - 15:30
  • Where: Cole 1.33
  • Series: School Seminar Series
  • Format: Seminar, Talk

School Seminar ‘Closure Experiences in Digital Product Design’ by Joe Macleod

“Closure Experiences in Digital Product Design. The loss of the resolution in the shop of abundance”

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Abstract
Most experiences in life are punctuated by a closure experience. In the past these were profound; however, over generations we have distanced ourselves from meaningful closure experiences thanks to our lifestyles increasing in comfort, the church weakening and medicine advancing. This has seemingly freed us from the shackles of the ultimate closure experience – death – and sanctioning our personal pursuit of heaven on earth in the form of consumption. We are now encouraged to drunkenly stumble from purchase to purchase, with any sense of longevity and responsibility removed. Long term side effects of this are exampled in the Product, Service and Digital landscapes that we frequent. The consequences of our behaviour results in a changing climate, industries fined billions for mis-selling and individuals casually eroding their personal online reputations. Many of us are active in the creation of services, products or digital products; making them attractive, engaging and usable for consumers, but we often overlook concluding these experiences for the user in a responsible way. Closure Experiences offers a model to frame this change.

Bio
Joe Macleod has been working in the mobile design space since 1998 and has been involved in a pretty diverse range of projects. At Nokia he helped develop some of the most streamlined packaging in the world, he created a hack team to disrupt the corporate drone of powerpoint, produced mobile services for pregnant women in Africa and pioneered lighting behavior for millions of phones. For the last four years he has been key to establishing ustwo as the UKs best digital product studio, with 180 people globally in London, New York, Sydney and Sweden, while also successfully building education initiatives, curriculums and courses on the back of the IncludeDesign campaign which launched in 2013. He now works independently on projects and has recently established established Closure Experiences, a new business looking at issues around consumption, consumerism and designing the end of things.

Event details

  • When: 29th March 2016 14:00 - 15:00
  • Where: Cole 1.33
  • Series: School Seminar Series
  • Format: Seminar, Talk