Runtime MPI Correctness Checking with a Scalable Tools Infrastructure

Increasing computational demand of simulations motivates the use of parallel computing systems. At the same time, this parallelism poses challenges to application developers. The Message Passing Interface (MPI) is a de-facto standard for distributed memory programming in high performance computing. However, its use also enables complex parallel programing errors such as races, communication errors, and deadlocks. Automatic tools can assist application developers in the detection and removal of such errors. This thesis considers tools that detect such errors during an application run and advances them towards a combination of both precise checks (neither false positives nor false negatives) and scalability. This includes novel hierarchical checks that provide scalability, as well as a formal basis for a distributed deadlock detection approach. At the same time, the development of parallel runtime tools is challenging and time consuming, especially if scalability and portability are key design goals. Current tool development projects often create similar tool components, while component reuse remains low. To provide a perspective towards more efficient tool development, which simplifies scalable implementations, component reuse, and tool integration, this thesis proposes an abstraction for a parallel tools infrastructure along with a prototype implementation. This abstraction overcomes the use of multiple interfaces for different types of tool functionality, which limit flexible component reuse. Thus, this thesis advances runtime error detection tools and uses their redesign and their increased scalability requirements to apply and evaluate a novel tool infrastructure abstraction. The new abstraction ultimately allows developers to focus on their tool functionality, rather than on developing or integrating common tool components. The use of such an abstraction in wide ranges of parallel runtime tool development projects could greatly increase component reuse. Thus, decreasing tool development time and cost. An application study with up to 16,384 application processes demonstrates the applicability of both the proposed runtime correctness concepts and of the proposed tools infrastructure

An ostensive information architecture to enhance semantic interoperability for healthcare information systems

Semantic interoperability establishes intercommunications and enables data sharing across disparate systems. In this study, we propose an ostensive information architecture for healthcare information systems to decrease ambiguity caused by using signs in different contexts for different purposes. The ostensive information architecture adopts a consensus-based approach initiated from the perspective of information systems re-design and can be applied to other domains where information exchange is required between heterogeneous systems. Driven by the issues in FHIR (Fast Health Interoperability Resources) implementation, an ostensive approach that supplements the current lexical approach in semantic exchange is proposed. A Semantic Engine with an FHIR knowledge graph as the core is constructed using Neo4j to provide semantic interpretation and examples. The MIMIC III (Medical Information Mart for Intensive Care) datasets and diabetes datasets have been employed to demonstrate the effectiveness of the proposed information architecture. We further discuss the benefits of the separation of semantic interpretation and data storage from the perspective of information system design, and the semantic reasoning towards patient-centric care underpinned by the Semantic Engine

Capital\u27s Media: The Physical Conditions of Circulation

The question of what constitutes media has received little attention in Marxism and where it does, the concept is an empty abstraction. While Marxists have extensively theorized the concentration of mass media ownership, and analyzed mass media content as ideology or propaganda, critical discussions of what a medium is in the capitalist mode of production have been mostly lacking. That is to say, Marxism does not have a media ontology. Media is therefore a critical gap in Marx’s political economy. This dissertation seeks to fill this gap by asking what is a medium in the capitalist mode of production?, answering it with a valueform theory of media and a concept of “capital’s media” that takes the circulation of capital as its starting point. The dissertation goes beyond Marxism’s mass media myopia and moves the concept of media towards logistics and infrastructure. The contributions this dissertation makes are to (1) develop a theory and category of capital’s media as a phenomenon of the circulation process of capital; (2) stake out an approach to investigate media phenomenon outside of pure political economy and cultural studies approaches; and in the process (3) contribute towards a rehabilitation of Marx’s analysis of circulation. To make these contributions this dissertation relies on a theoretical framework that is primarily based on Marx’s value theory, but enriched with concepts from Canadian- German media theory (Harold A. Innis, Marshall McLuhan, Friedrich Kittler, Wolfgang Ernst, and Hartmut Winkler) and Paul Virilio’s dromology. This dissertation has two components to its methodology: an original “circulationist” reading of Marx’s political economy that is developed from the heterodox Neue Marx-Lektüre (New Marx Reading), and a set of empirical case studies that includes the shipping container and intermodal transportation, distribution centers, and point-of-sale and payment systems Positing a category of capital’s media, this dissertation concludes that nothing by its very nature is a medium but instead that things function as media when they appear in that category. More specifically, a thing, such as a container ship or distribution center, appears in the category of capital’s media when they function within and for the circulation process

Data infrastructures and digital labour : the case of teleradiology

In this thesis, I investigate the effects of digitalisation in teleradiology, the practice of outsourcing radiology diagnosis, through an analysis of the role of infrastructures that enable the transfer, storage, and processing of digital medical data. Consisting of standards, code, protocols and hardware, these infrastructures contribute to the making of complex supply chains that intervene into existing labour processes and produce interdependent relations among radiologists, patients, data engineers, and auxiliary workers. My analysis focuses on three key infrastructures that facilitate teleradiology: Picture Archiving and Communication Systems (PACS), the Digital Imaging and Communication in Medicine (DICOM) standard, and the Health Level 7 (HL7) standard. PACS is a system of four interconnected components: imaging hardware, a secure network, viewing stations for reading images, and data storage facilities. All of these components use DICOM, which specifies data formats and network protocols for the transfer of data within PACS. HL7 is a standard that defines data structures for the purposes of transfer between medical information systems. My research draws on fieldwork in teleradiology companies in Sydney, Australia, and Bangalore, India, which specialise in international outsourcing of medical imaging diagnostics and provide services for hospitals in Europe, USA, and Singapore, among others. I argue that PACS, DICOM, and HL7 establish a technopolitical context that erodes boundaries between social institutions of labour management and material infrastructures of data control. This intertwining of bureaucratic and infrastructural modes of regulation gives rise to a variety of strategies deployed by companies for maximising productivity, as well as counter-strategies of workers in leveraging mobility and qualifications to their advantage