Universality of the Future Chronological Boundary

The purpose of this note is to establish, in a categorical manner, the universality of the Geroch-Kronheimer-Penrose causal boundary when considering the types of causal structures that may profitably be put on any sort of boundary for a spacetime. Actually, this can only be done for the future causal boundary (or the past causal boundary) separately; furthermore, only the chronology relation, not the causality relation, is considered, and the GKP topology is eschewed. The final result is that there is a unique map, with the proper causal properties, from the future causal boundary of a spacetime onto any ``reasonable" boundary which supports some sort of chronological structure and which purports to consist of a future completion of the spacetime. Furthermore, the future causal boundary construction is categorically unique in this regard.Comment: 25 pages, AMS-TeX; 2 figures, PostScript (separate); captions (separate); submitted to Class. Quantum Grav, slight revision: bottom lines legible, figures added, expanded discussion and example

Ontology Winnowing: A Case Study on the AKT Reference Ontology

Many ontologies are built for the main purpose of representing a domain, rather than to meet the requirements of a specific application. When applications and services are deployed over an ontology, it is sometimes the case that only few parts of the ontology are queried and used. Identifying which parts of an ontology are being used could useful for realising the necessary fragments of the ontology to run the applications. Such information could be used to winnow an ontology, i.e., simplifying or shrinking the ontology to smaller, more fit for purpose sizes. This paper presents a study on the use of the AKT Reference Ontology by a number of applications and services, and investigate the possibility of using this information to winnow that ontology

The Trichoptera of Panama XIV. New species of microcaddisflies (Trichoptera: Hydroptilidae) from Omar Torrijos Herrera National Park

Abstract. In 2017, a new project was begun to assess the biodiversity of national parks and forest reserves in the Republic of Panama. Designated “Proyecto Sistema de Producción Sostenible Conservación de la Biodiversidad (PSPSCB)”, this project is managed by Panama’s Ministerio de Ambiente. The first park sampled in 2017 was Omar Torrijos Herrera National Park (OTHNP). Trichoptera (Insecta) were collected at four locations using both Malaise traps and UV light traps. The rugged terrain and lack of access in this remote park limited the sampled area. Sampling included streams in both the Caribbean and Pacific drainages. Seven new species of microcaddis­flies (Hydroptilidae: Alistotrichia coclensis Armitage and Harris, Cerasmatrichia akanthos Armitage and Harris, Metrichia corazones Armitage and Harris, Neotrichia espinosa Armitage and Harris, Neotrichia michaeli Armit­age and Harris, Neotrichia pierpointorum Armitage and Harris, and Neotrichia yayas Armitage and Harris) and one new country record, Metrichia macrophallata Flint, were identified from this preliminary survey and are re­ported herein. Other recently described species are reported here for the first time outside of their type localities. Based on other areas more extensively sampled compared to this modest survey, many more new species and new country records await discovery in OTHNP as are reported herein. There are now 439 species distributed among 15 families and 55 genera known from Panama. Resumen. En 2017, se inició un nuevo proyecto para evaluar la biodiversidad de parques nacionales y reservas forestales en la República de Panamá. Designado “Proyecto Sistema de Producción Sostenible Conservación de la Biodiversidad (PSPSCB)”, este proyecto es administrado por el Ministerio de Ambiente de Panamá. El primer parque muestreado en 2017 fue el Parque Nacional Omar Torrijos Herrera (OTHNP). Se recogieron Trichoptera en cuatro ubicaciones utilizando trampas Malaise y trampas de luz UV. El terreno accidentado y la falta de acceso en este parque remoto limitaron el área muestreada. El muestreo incluyó corrientes en los drenajes del Caribe y del Pacífico. Siete nuevas especies de micro-Trichoptera (Hydroptilidae: Alistotrichia coclensis Armitage and Harris, Cerasmatrichia akanthos Armitage and Harris, Metrichia corazones Armitage and Harris, Neotrichia es­pinosa Armitage and Harris, Neotrichia michaeli Armitage and Harris, Neotrichia pierpointorum Armitage and Harris, and Neotrichia yayas Armitage and Harris) y un nuevo registro de país, Metrichia macrophallata Flint, se identificaron a partir de esta encuesta preliminar y se informan aquí. Otras especies recientemente descritas se registran aquí por primera vez fuera de sus localidades tipo. Con base en otras áreas más extensamente mues­treadas, en comparación con esta modesta investigación, muchas más especies nuevas y nuevos registros para el país esperan ser descubiertos en el OTHNP como se informa aquí. Ahora en Panamá, hay 439 especies conocidas de Trichoptera distribuidas entre 15 familias y 55 géneros

Discrete Group Actions on Spacetimes: Causality Conditions and the Causal Boundary

Suppose a spacetime $M$ is a quotient of a spacetime $V$ by a discrete group of isometries. It is shown how causality conditions in the two spacetimes are related, and how can one learn about the future causal boundary on $M$ by studying structures in $V$. The relations between the two are particularly simple (the boundary of the quotient is the quotient of the boundary) if both $V$ and $M$ have spacelike future boundaries and if it is known that the quotient of the future completion of $V$ is past-distinguishing. (That last assumption is automatic in the case of $M$ being multi-warped.)Comment: 32 page

Investigating Single Precision Floating General Matrix Multiply in Heterogeneous Hardware

The fundamental operation of matrix multiplication is ubiquitous across a myriad of disciplines. Yet, the identification of new optimizations for matrix multiplication remains relevant for emerging hardware architectures and heterogeneous systems. Frameworks such as OpenCL enable computation orchestration on existing systems, and its availability using the Intel High Level Synthesis compiler allows users to architect new designs for reconfigurable hardware using C/C++. Using the HARPv2 as a vehicle for exploration, we investigate the utility of several of the most notable matrix multiplication optimizations to better understand the performance portability of OpenCL and the implications for such optimizations on this and future heterogeneous architectures. Our results give targeted insights into the applicability of best practices that were for existing architectures when used on emerging heterogeneous systems

Application of expert systems in project management decision aiding

The feasibility of developing an expert systems-based project management decision aid to enhance the performance of NASA project managers was assessed. The research effort included extensive literature reviews in the areas of project management, project management decision aiding, expert systems technology, and human-computer interface engineering. Literature reviews were augmented by focused interviews with NASA managers. Time estimation for project scheduling was identified as the target activity for decision augmentation, and a design was developed for an Integrated NASA System for Intelligent Time Estimation (INSITE). The proposed INSITE design was judged feasible with a low level of risk. A partial proof-of-concept experiment was performed and was successful. Specific conclusions drawn from the research and analyses are included. The INSITE concept is potentially applicable in any management sphere, commercial or government, where time estimation is required for project scheduling. As project scheduling is a nearly universal management activity, the range of possibilities is considerable. The INSITE concept also holds potential for enhancing other management tasks, especially in areas such as cost estimation, where estimation-by-analogy is already a proven method