36,128 research outputs found
Recommended from our members
Images of resistance: A photonarrative enquiry into the meanings of personal artwork for people living with cancer
This study explored the meanings, inspirations and subjective significance of personal artwork created as a leisure activity by women living with cancer. A convenience sample of twelve women aged between 23-74 years participated in semi-structured interviews. Participants were living in various stages of the cancer trajectory, and engaged in several forms of visual art-making. They submitted examples of their artwork by photograph and then participated in semi-structured interviews. From a phenomenological analysis, the authors inferred a number of themes. Participants perceived a few pieces, made during chemotherapy, as expressing deeper feelings about cancer in symbolic terms. More prevalent in participants’ accounts were references to their artwork as a sensuous pleasure, and its confirmation of their ongoing capability, personal continuity and social connectedness. Participants acknowledged ongoing loss and difficulties related to cancer. However, each piece of art offered a measure of resistance against the psychologically and socially disruptive effects of cancer. The pre-interview photography activity was helpful for empowering participants in the interview, and for stimulating detailed memories and associations
Boron-oxygen defect imaging in p-type Czochralski silicon
In this work, we demonstrate an accurate method for determining the effective boron-oxygen (BO) related defect density on Czochralski-grown silicon wafers using photoluminescence imaging. Furthermore, by combining a recently developed dopant density imaging technique and microscopic Fourier transform infrared spectroscopy measurements of the local interstitial oxygen concentration [Oi ], the BO-related defect density, [Oi ], and the boron dopant density from the same wafer were determined, all with a spatial resolution of 160 μm. The results clearly confirm the established dependencies of the BO-related defect density on [Oi ] and the boron dopant density and demonstrate a powerful technique for studying this important defect.This work was supported by the Australian Research
Council (ARC) Future Fellowships program and the
Australian Renewable Energy Agency (ARENA) fellowships
program
Tracking in a space variant active vision system
Without the ability to foveate on and maintain foveation, active vision for applications such as surveillance, object recognition and object tracking are difficult to build. Although foveation in cartesian coordinates is being actively pursued by many, multi-resolution high accuracy foveation in log polar space has not been given much attention. This paper addresses the use of foveation to track a single object as well as multiple objects for a simulated space variant active vision system. Complex logarithmic mapping is chosen firstly because it provides high resolution and wide angle viewing. Secondly, the spatially variant structure of log polar space leads to an object increasing in size as it moves towards the fovea. This is important as we know which object is closer to the fovea at any instant in time.<br /
A formal definition and a new security mechanism of physical unclonable functions
The characteristic novelty of what is generally meant by a "physical
unclonable function" (PUF) is precisely defined, in order to supply a firm
basis for security evaluations and the proposal of new security mechanisms. A
PUF is defined as a hardware device which implements a physical function with
an output value that changes with its argument. A PUF can be clonable, but a
secure PUF must be unclonable. This proposed meaning of a PUF is cleanly
delineated from the closely related concepts of "conventional unclonable
function", "physically obfuscated key", "random-number generator", "controlled
PUF" and "strong PUF". The structure of a systematic security evaluation of a
PUF enabled by the proposed formal definition is outlined. Practically all
current and novel physical (but not conventional) unclonable physical functions
are PUFs by our definition. Thereby the proposed definition captures the
existing intuition about what is a PUF and remains flexible enough to encompass
further research. In a second part we quantitatively characterize two classes
of PUF security mechanisms, the standard one, based on a minimum secret
read-out time, and a novel one, based on challenge-dependent erasure of stored
information. The new mechanism is shown to allow in principle the construction
of a "quantum-PUF", that is absolutely secure while not requiring the storage
of an exponentially large secret. The construction of a PUF that is
mathematically and physically unclonable in principle does not contradict the
laws of physics.Comment: 13 pages, 1 figure, Conference Proceedings MMB & DFT 2012,
Kaiserslautern, German
Advanced nickel-cadmium batteries for geosynchronous spacecraft
A nickel cadmium battery was developed that can be operated at 80 percent depth of discharge in excess of 10 years in a geosynchronous orbit application, and has about a 30 percent weight savings per spacecraft over present nickel cadmium batteries when used with a 1000 watts eclipse load. The approach used in the development was to replace nylon separators with inert polymer impregnated zirconia, use electrochemically deposited plates in place of conventional chemically precipitated ones, and use an additive to extend negative plate lifetime. The design has undergone extensive testing using both engineering and protoflight cell configurations
- …