69 research outputs found
PSL Icing Facility Upgrade Overview
The NASA Glenn Research Center Propulsion Systems Lab (PSL) was recently upgraded to perform engine inlet ice crystal testing in an altitude environment. The system installed 10 spray bars in the inlet plenum for ice crystal generation using 222 spray nozzles. As an altitude test chamber, the PSL is capable of simulating icing events at altitude in a groundtest facility. The system was designed to operate at altitudes from 4,000 to 40,000 ft at Mach numbers up to 0.8M and inlet total temperatures from -60 to +15 degF. This paper and presentation will be part of a series of presentations on PSL Icing and will cover the development of the icing capability through design, developmental testing, installation, initial calibration, and validation engine testing. Information will be presented on the design criteria and process, spray bar developmental testing at Cox and Co., system capabilities, and initial calibration and engine validation test. The PSL icing system was designed to provide NASA and the icing community with a facility that could be used for research studies of engine icing by duplicating in-flight events in a controlled ground-test facility. With the system and the altitude chamber we can produce flight conditions and cloud environments to simulate those encountered in flight. The icing system can be controlled to set various cloud uniformities, droplet median volumetric diameter (MVD), and icing water content (IWC) through a wide variety of conditions. The PSL chamber can set altitudes, Mach numbers, and temperatures of interest to the icing community and also has the instrumentation capability of measuring engine performance during icing testing. PSL last year completed the calibration and initial engine validation of the facility utilizing a Honeywell ALF502-R5 engine and has duplicated in-flight roll back conditions experienced during flight testing. This paper will summarize the modifications and buildup of the facility to accomplish these tests
Reasoning About a Service-oriented Programming Paradigm
This paper is about a new way for programming distributed applications: the
service-oriented one. It is a concept paper based upon our experience in
developing a theory and a language for programming services. Both the
theoretical formalization and the language interpreter showed us the evidence
that a new programming paradigm exists. In this paper we illustrate the basic
features it is characterized by
Nonhuman humanitarianism: when ‘AI for good’ can be harmful
Artificial intelligence (AI) applications have been introduced in humanitarian operations in order to help with the significant challenges the sector is facing. This article focuses on chatbots which have been proposed as an efficient method to improve communication with, and accountability to affected communities. Chatbots, together with other humanitarian AI applications such as biometrics, satellite imaging, predictive modelling and data visualisations, are often understood as part of the wider phenomenon of ‘AI for social good’. The article develops a decolonial critique of humanitarianism and critical algorithm studies which focuses on the power asymmetries underpinning both humanitarianism and AI. The article asks whether chatbots, as exemplars of ‘AI for good’, reproduce inequalities in the global context. Drawing on a mixed methods study that includes interviews with seven groups of stakeholders, the analysis observes that humanitarian chatbots do not fulfil claims such as ‘intelligence’. Yet AI applications still have powerful consequences. Apart from the risks associated with misinformation and data safeguarding, chatbots reduce communication to its barest instrumental forms which creates disconnects between affected communities and aid agencies. This disconnect is compounded by the extraction of value from data and experimentation with untested technologies. By reflecting the values of their designers and by asserting Eurocentric values in their programmed interactions, chatbots reproduce the coloniality of power. The article concludes that ‘AI for good’ is an ‘enchantment of technology’ that reworks the colonial legacies of humanitarianism whilst also occluding the power dynamics at play
A preliminary dictionary of Maori gainwords compiled on historical principles
This thesis is a preliminary dictionary of Maori gainwords compiled on historical principles. It will serve as the starting point for a fully fledged historical dictionary of Maori gainwords. The sources are a selection of all those Maori language publications printed between the dates 1815 and 1899. A large number of source items were photocopied from other institutions, and the binding and subsequent availability of these was not always in the order wished for. The research therefore has its limitations (clearly indicated by the use of the word 'preliminary' in the thesis title). Full coverage of all printed Maori publications between 1815 and 1899 has not been possible. Despite this, this preliminary dictionary offers a good indication of the extent of new gainword vocabulary introduced within the time frame. This thesis suggests that the terms loanword and borrowing should
be replaced by the new term gainword or gain, and that the process
by which new items of vocabulary enter a language should be known
as gaining .. 'Gaining' is a positive process, and the word 'gainword' is
normally devoid of any negative connotations or implications of
cultural imperialism.
This thesis is the first extended scholarly research into Maori
gainword lexicography. Although 'preliminary', the dictionary is the
first devoted solely to Maori gainwords - previous dictionaries of
Maori have had gainwords as appendices, or have listed small
numbers of gainwords in their general corpus. This dictionary builds
on those earlier dictionaries by giving gainwords their own
dictionary.
This thesis will indicate that nearly all new items of vocabulary
introduced into Maori language during the period researched were
introduced by English-speaking Pakeha. English-speaking (and some
few French-speaking) Pakeha controlled the printed word for some
considerable time - up until the first Maori-controlled publication,
Te Hokioi in 1861, in fact most gainwords were therefore imposed.
The frequency count for Maori-driven gains done for this thesis will
give only some slight indication of Maori use and acceptance of gains
between 1815 and 1899
Experiences from the ImageCLEF Medical Retrieval and Annotation Tasks
The medical tasks in ImageCLEF have been run every year from 2004-2018 and many different tasks and data sets have been used over these years. The created resources are being used by many researchers well beyond the actual evaluation campaigns and are allowing to compare the performance of many techniques on the same grounds and in a reproducible way. Many of the larger data sets are from the medical literature, as such images are easier to obtain and to share than clinical data, which was used in a few smaller ImageCLEF challenges that are specifically marked with the disease type and anatomic region. This chapter describes the main results of the various tasks over the years, including data, participants, types of tasks evaluated and also the lessons learned in organizing such tasks for the scientific community
Technocolonialism: digital innovation and data practices in the humanitarian response to refugee crises
Digital innovation and data practices are increasingly central to the humanitarian response to recent refugee and migration crises. In this article I introduce the concept of technocolonialism to capture how the convergence of digital developments with humanitarian structures and market forces reinvigorates and reshapes colonial relationships of dependency. Technocolonialism shifts the attention to the constitutive role that data and digital innovation play in entrenching power asymmetries between refugees and aid agencies and ultimately inequalities in the global context. This occurs through a number of interconnected processes: by extracting value from refugee data and innovation practices for the benefit of various stakeholders; by materializing discrimination associated with colonialism; by contributing to the production of social orders that entrench the ‘coloniality of power’ and by justifying some of these practices under the context of ‘emergencies’. By reproducing the power asymmetries of humanitarianism, data and innovation practices become constitutive of humanitarian crises themselves
Abstract The design and implementation of the NCTUns network
NCTUns is a network simulator running on Linux. It has several unique advantages over traditional network simulators. This paper presents the novel design and implementation of its simulation engine. This paper focuses on how to combine the kernel re-entering and discrete-event simulation methodologies to execute simulations quickly. The performance and scalability of NCTUns are also presented and discussed. Ó 2006 Elsevier B.V. All rights reserved
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