3,152 research outputs found
Robot navigation control based on monocular images: An image processing algorithm for obstacle avoidance decisions
This paper covers the use of monocular vision to control autonomous navigation for a robot in a dynamically changing environment. The solution focused on using colour segmentation against a selected floor plane to distinctly separate obstacles from traversable space, this is then supplemented with canny edge detection to separate similarly coloured boundaries to the floor plane. The resulting binary map (where white identifies an obstacle-free area and black identifies an obstacle) could then be processed by fuzzy logic or neural networks to control the robot’s next movements. Findings shows that the algorithm performed strongly on solid coloured carpets, wooden and concrete floors but had difficulty in separating colours in multi-coloured floor types such as patterned carpets
APPLICATION OF GAME THEORY FOR ACTIVE CYBER DEFENSE AGAINST ADVANCED PERSISTENT THREATS
Advanced persistent threats (APTs) are determined, adaptive, and stealthy threat actors in cyber space. They are often hosted in, or sponsored by, adversary nation-states. As such, they are challenging opponents for both the U.S. military and the cyber-defense industry. Current defenses against APTs are largely reactive. This thesis used machine learning and game theory to test simulations of proactive defenses against APTs. We first applied machine learning to two benchmark APT datasets to classify APT network traffic by attack phase. This data was then used in a game model with reinforcement learning to learn the best tactics for both the APT attacker and the defender. The game model included security and resource levels, necessary conditions on actions, results of actions, success probabilities, and realistic costs and benefits for actions. The game model was run thousands of times with semi-random choices with reinforcement learning through a program created by NPS Professor Neil Rowe. Results showed that our methods could model active cyber defense strategies for defenders against both historical and hypothetical APT campaigns. Our game model is an extensible planning tool to recommend actions for defenders for active cyber defense planning against APTs.Approved for public release. Distribution is unlimited.Captain, United States Marine CorpsCaptain, United States Marine CorpsDISA, Arlington, VA, 2220
Conceptualising the adoption of sustainable procurement: An institutional theory perspective
Sustainable procurement and supply chain management studies are growing; however several scholars have criticised the lack of theoretical development accompanying this literature. Sustainable procurement and supply chain management activities form part of an organisation's path to adopt sustainability. Some scholars have suggested examining the application of management theories to describe the introduction of corporate sustainability to address this gap. Institutional theory is frequently used to describe how new practices are adopted in organisations and has also been applied to several corporate social responsibility studies. This conceptual paper examines the applicability of institutional theory to describe the adoption of sustainable procurement and concludes by presenting three theoretical propositions to explain sustainable procurement adoption. © 2014 Environment Institute of Australia and New Zealand Inc
Young Muslim women's experiences of Islam and physical education in Greece and Britain: a comparative study
Previous research suggests that Muslim women can experience particular problems when taking physical education (PE) lessons, for example with dress codes, mixed-teaching and exercise during Ramadan; and they can face restrictions in extra-curricular activities for cultural and religious reasons. The area is under-researched and there is little evidence of comparative studies that explore similarities and differences in cross-national experiences, which is the aim of this paper. Two studies conducted in Greece and Britain that explored the views of Muslim women on school experiences of physical education are compared. Both studies focused on diaspora communities, Greek Turkish girls and British Asian women, living in predominantly non-Muslim countries. Growing concerns about global divisions between 'Muslims and the West' make this a particularly pertinent study. Qualitative data were collected by interviews with 24 Greek Muslim women, and 20 British Muslim women. \ud
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Physical education has national curriculum status and a similar rationale in both countries but with different cultures of formality and tradition, which impacted on pupils' experiences. Data suggested that Greek and British groups held positive views towards physical education but were restricted on their participation in extra-curricular activities. For the British women religious identity and consciousness of Islamic requirements were more evident than for the Greek women. Differences in stages of acculturation, historical and socio-cultural contexts contributed to less problematic encounters with physical education for Greek Muslims who appeared more closely assimilated into the dominant culture
An excess of damped Lyman alpha galaxies near QSOs
We present a sample of 33 damped Lyman alpha systems (DLAs) discovered in the
Sloan Digital Sky Survey (SDSS) whose absorption redshifts (z_abs) are within
6000 km/s of the QSO's systemic redshift (z_sys). Our sample is based on 731
2.5 < z_sys < 4.5 non-broad-absorption-line (non-BAL) QSOs from Data Release 3
(DR3) of the SDSS. We estimate that our search is ~100 % complete for absorbers
with N(HI) >= 2e20 cm^-2. The derived number density of DLAs per unit redshift,
n(z), within v < 6000 km/s is higher (3.5 sigma significance) by almost a
factor of 2 than that of intervening absorbers observed in the SDSS DR3, i.e.
there is evidence for an overdensity of galaxies near the QSOs. This provides a
physical motivation for excluding DLAs at small velocity separations in surveys
of intervening 'field' DLAs. In addition, we find that the overdensity of
proximate DLAs is independent of the radio-loudness of the QSO, consistent with
the environments of radio-loud and radio-quiet QSOs being similar.Comment: Accepted for publication in MNRAS (13 pages, 6 figures
The role of symbolic capital in stakeholder disputes: Decision-making concerning intractable wastes
This paper examines almost 30 years of disputation concerning the disposal of the world's largest stockpile of the toxic organochlorine, hexachlorbenzene. It describes the study of a chemicals company in its attempt to manage the disposal of the toxic waste in a collaborative fashion with government, environmentalists and the local community. The study describes the new processes and structures specifically designed to address the decision-making and the issues of stakeholder perception and identity construction which have influenced the outcomes. Decision-making in such disputes is often theorized from the perspective of the emergence of highly individualized and reflexive risk communities and changing modes and expectations of corporate responsibility as a result of detraditionalization. We argue that the stakeholder interaction in this study reflects competing discourses in which corporate actors prioritize the building and maintaining of identity and symbolic capital rather than an active collaboration to solve the ongoing issue of the waste. As well, issues of access to expert knowledge highlight the relationship between conditions of uncertainty, technoscientific expertise and identity. The events of the study highlight the challenges faced by contemporary technoscientific corporations such as chemicals companies as they must deliver on requirements of transparency and openness, while maintaining technoscientific capacity and strong internal identity. We conclude that the study demonstrates the co-existence of social processes of individualization and detraditionalization with quasi-traditions which maintain authority, thus challenging the radical distinctions made in the literature between modernity and late or reflexive modernity. © 2008 Elsevier Ltd. All rights reserved
Organising for Ecological Repair: Reconstructing Land Management Practice
© 2015, © 2015 SAGE Publications. In this article, we explore organising narratives that underpin the generation of effective ecological solutions. We examine the processes of meaning construction in relation to the development of sustainable land management practices in the Landcare organisation in Australia. Meaning construction is situated in a variety of contexts that are themselves strongly influenced by a meta-narrative, which Taylor has labelled the “modern social imaginary”: A shared system of meanings that captures the imaginations of individuals and shapes their social groupings and society. The shift in meaning construction is reflected in the emergence of a narrative of “ecological repair” that involved a process of learning and knowledge development we have labelled protracted sense-making. Our research findings have led us to conclude that the development of successful ecological solutions require an active rewriting of the social imaginary
An inside story: tracking experiences, challenges and successes in a joint specialist performing arts college
In England the government’s specialist schools initiative is transforming the nature of secondary education. A three-year longitudinal case study tracked the effects of specialist performing arts college status on two schools. The sites were a mainstream school drawing pupils from an area of high social deprivation and disadvantage, and a special school catering for pupils with profound and \ud
multiple learning difficulties, which were awarded joint performing arts college status. The government’s \ud
preferred criterion for judging the success of specialist schools is improvement in whole-school examination results. The authors argue that this is a crude and inappropriate measure for these case study schools and probably others. Using questionnaires, interviews and documentation they tell an ‘inside story’ of experiences, challenges and achievements, from the perspectives of the schools’ mangers, staff and pupils. Alternative ‘value-added’ features emerged that were positive indicators of enrichment and success in both schools
Maxwell's Equations in a Uniformly Rotating Dielectric Medium and the Wilson-Wilson Experiment
This note offers a conceptually straightforward and efficient way to
formulate and solve problems in the electromagnetics of moving media based on a
representation of Maxwell's equations in terms of differential forms on
spacetime together with junction conditions at moving interfaces. This
framework is used to address a number of issues that have been discussed
recently in this journal about the theoretical description underlying the
interpretation of the Wilson-Wilson experiment.Comment: 16 pages, 2 figure
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