Skeletons for Distributed Topological Computation

Parallel implementation of topological algorithms is highly desirable, but the challenges, from reconstructing algorithms around independent threads through to runtime load balancing, have proven to be formidable. This problem, made all the more acute by the diversity of hardware platforms, has led to new kinds of implementation platform for computational science, with sophisticated runtime systems managing and coordinating large threadcounts to keep processing elements heavily utilized. While simpler and more portable than direct management of threads, these approaches still entangle program logic with resource management. Similar kinds of highly parallel runtime system have also been developed for functional languages. Here, however, language support for higher-order functions allows a cleaner separation between the algorithm and `skeletons' that express generic patterns of parallel computation. We report results on using this technique to develop a distributed version of the Joint Contour Net, a generalization of the Contour Tree to multifields. We present performance comparisons against a recent Haskell implementation using shared-memory parallelism, and initial work on a skeleton for distributed memory implementation that utilizes an innovative strategy to reduce inter-process communication overheads

In a New Land:Mobile Phones, Amplified Pressures and Reduced Capabilities

Framed within the theoretical lens of positive and negative security, this paper presents a study of newcomers to Sweden and the roles of mobile phones in the establishment of a new life. Using creative engagement methods through a series of workshops, two researchers engaged 70 adult participants enrolled into further education colleges in Sweden. Group narratives about mobile phone use were captured in creative outputs, researcher observations and notes and were analysed using thematic analysis. Key findings show that the mobile phone offers security for individuals and a safe space for newcomers to establish a new life in a new land as well as capitalising on other spaces of safety, such as maintaining old ties. This usage produces a series of threats and vulnerabilities beyond traditional technological security thinking related to mobile phone use. The paper concludes with recommendations for policies and support strategies for those working with newcomers

Using approximate matching to reduce the volume of digital data

Digital forensic investigators frequently have to search for relevant files in massive digital corpora – a task often compared to finding a needle in a haystack. To address this challenge, investigators typically apply cryptographic hash functions to identify known files. However, cryptographic hashing only allows the detection of files that exactly match the known file hash values or fingerprints. This paper demonstrates the benefits of using approximate matching to locate relevant files. The experiments described in this paper used three test images of Windows XP, Windows 7 and Ubuntu 12.04 systems to evaluate fingerprint-based comparisons. The results reveal that approximate matching can improve file identification – in one case, increasing the identification rate from 1.82% to 23.76%

An Augmented Reality Periscope for Submarines with Extended Visual Classification

Submarines are considered extremely strategic for any naval army due to their stealth capability. Periscopes are crucial sensors for these vessels, and emerging to the surface or periscope depth is required to identify visual contacts through this device. This maneuver has many procedures and usually has to be fast and agile to avoid exposure. This paper presents and implements a novel architecture for real submarine periscopes developed for future Brazilian naval fleet operations. Our system consists of a probe that is connected to the craft and carries a 360 camera. We project and take the images inside the vessel using traditional VR/XR devices. We also propose and implement an efficient computer vision-based MR technique to estimate and display detected vessels effectively and precisely. The vessel detection model is trained using synthetic images. So, we built and made available a dataset composed of 99,000 images. Finally, we also estimate distances of the classified elements, showing all the information in an AR-based interface. Although the probe is wired-connected, it allows for the vessel to stand in deep positions, reducing its exposure and introducing a new way for submarine maneuvers and operations. We validate our proposal through a user experience experiment using 19 experts in periscope operations

Towards a Declarative Language for Parallel and Concurrent Programming

We define a new language Eden by extending a functional language by constructs for the explicit specification of dynamic process systems. Concurrent systems can be classified either as transformational or reactive. For modelling the class of transformational systems, the introduction of a function-like abstraction mechanism is sufficient. In addition to this, the extra-functional concepts predefined nondeterministic processes and dynamic reply channels make the definition of reactive systems possible. The former construct is used to handle time-dependencies. The latter, which is similar to the incomplete message principle from concurrent logic programming, is a powerful mechanism for the treatment of dynamically specified communication channels. 1 Introduction Most parallel programming languages used nowadays are based on the imperative programming paradigm. In such languages, synchronization and communication between processes must be handled by the programmer at a low level of abst..

Sized Types for Typing Eden Skeletons

The parallel-functional language Eden extends Haskell by constructs to explicitly dene and communicate processes. These extensions allow the easy denition of skeletons as higher-order functions. However, the programmer can inadvertently introduce busy loops or deadlocks in them. In this paper a sized type system is extended in order to use it for Eden programs, so that those well-typed skeletons are guaranteed either to terminate or to be productive. The problems raised by Eden features and their possible solutions are described in detail, and several skeletons are typed in this modied system such as the parallel map, farm, pipeline, divide and conquer, and replicated workers.