Manipulation of Light with Magneto-optic Stripe Domain Films

Magnetic diffraction grating materials, being developed to provide a simple means of deflecting light in a two dimensional, solid state fashion are discussed. The most promising material, for several applications, appears to be bismuth substituted iron garnet films in epitaxial form. Calculations indicate that deflection efficiency greater than 60% is possible in the near infrared region of the spectrum. Within the field of view of the deflector, measurements predict that 105 resolvable spots can be expected. Applications include: (1) general purpose deflection of free laser light, (2) image processing of extended sources such as transparencies, (3) programmable lensing, and (4) fiber optic matrix switching

Ames collaborative study of cosmic-ray neutrons. 2: Low- and mid-latitude flights

Progress of the study of cosmic ray neutrons is described. Data obtained aboard flights from Hawaii at altitudes of 41,000 and 45,000 feet, and in the range of geomagnetic latitude 17 N less than or equal to lambda less than or equal to 21 N are reported. Preliminary estimates of neutron spectra are made

Flow in a slowly-tapering channel with oscillating walls

The flow of a fluid in a channel with walls inclined at an angle to each other is investigated at arbitrary Reynolds number. The flow is driven by an oscillatory motion of the wall incorporating a time-periodic displacement perpendicular to the channel centreline. The gap between the walls varies linearly with distance along the channel and is a prescribed periodic function of time. An approximate solution is constructed assuming that the angle of inclination of the walls is small. At leading order the flow corresponds to that in a channel with parallel, vertically oscillating walls examined by Hall and Papageorgiou \cite{HP}. A careful study of the governing partial differential system for the first order approximation controlling the tapering flow due to the wall inclination is conducted. It is found that as the Reynolds number is increased from zero the tapering flow loses symmetry and undergoes exponential growth in time. The loss of symmetry occurs at a lower Reynolds number than the symmetry-breaking for the parallel-wall flow. A window of asymmetric, time-periodic solutions is found at higher Reynolds number, and these are reached via a quasiperiodic transient from a given set of initial conditions. Beyond this window stability is again lost to exponentially growing solutions as the Reynolds number is increased

Incorporating Global Information Security and Assurance in I.S. Education

Over the years, the news media has reported numerous information security incidents. Because of identity theft, terrorism, and other criminal activities, President Obama has made information security a national priority. Not only is information security and assurance an American priority, it is also a global issue. This paper discusses the importance of Global Information Security and Assurance in information systems (IS) education. Current university graduates will become tomorrow’s users and protectors of data and systems. It is important for universities to provide training in security and assurance of information systems. Are students getting adequate education in this area? If not, this leaves them ill-prepared for the needs of the workplace. The security of our information systems needs to be a major concern for educators and corporate leaders. We recommend that instruction in security and assurance be a core component of the curriculum for all IS and business students. The purpose of this special issue is to provide insights, ideas, and practical tips from IS educators and professionals. Along with the academic papers in this issue, a new section was added, advisory from professionals. Just as a university information systems department has an advisory board of professionals, this new section provides an advisory to academics; professionals provide insights into the corporate world and they need

Validating an Operations Centre Model

An airline operations centre determines the imminent and future operations of an airline by assessing the current situation, considering current constraints and then issuing a high level plan, describing which flights are operating, which are cancelled, which are delayed or rerouted, impacting aircraft, air crew, flight cabin crew, passengers and ground staff. Other departments of the airline transform the high level plan into detailed execution instructions. In the event, the system consists of a mixture of humans and machines both of which often provide and receive incomplete information, on which they make a decision, striving to execute as close as possible the ‘Ideal Plan’, which is the published timetable. The Airline Operations Decision Making Process is the ‘planning’ portion determining the next course of action, and the Airline Operations is the execution portion, putting the plans into action. In this context, the Study Group was asked to address the following problem: How do you validate a model of an airline’s decision processes to ensure a faithful representation of reality? By analysing model outputs and actual data, we found that the model does not satisfy any of our proposed “validation” criteria and have therefore suggested a series of possible ways forward for the model development team. We have provided visualisation tools in both Matlab and R, which will be of use in analysing subsequent model versions. We have also provided a series of statistical indicators of model quality. Lastly, and perhaps most importantly, we have described in detail what can be done if additional information were to be made available, for instance further runs of the model or extra data from the operations centre

Abstract Poisson summation formulas over homogeneous spaces of compact groups

This paper presents the abstract notion of Poisson summation formulas for homogeneous spaces of compact groups. Let G be a compact group, H be a closed subgroup of G, and μ be the normalized G-invariant measure over the left coset space G / H associated to the Weil’s formula. We prove that the abstract Fourier transform over G / H satisfies a generalized version of the Poisson summation formula

Environment and Obesity in the National Children\u27s Study

Objective: In this review we describe the approach taken by the National Children’s Study (NCS), a 21-year prospective study of 100,000 American children, to understanding the role of environmental factors in the development of obesity. Data sources and extraction: We review the literature with regard to the two core hypotheses in the NCS that relate to environmental origins of obesity and describe strategies that will be used to test each hypothesis. Data synthesis: Although it is clear that obesity in an individual results from an imbalance between energy intake and expenditure, control of the obesity epidemic will require understanding of factors in the modern built environment and chemical exposures that may have the capacity to disrupt the link between energy intake and expenditure. The NCS is the largest prospective birth cohort study ever undertaken in the United States that is explicitly designed to seek information on the environmental causes of pediatric disease. Conclusions: Through its embrace of the life-course approach to epidemiology, the NCS will be able to study the origins of obesity from preconception through late adolescence, including factors ranging from genetic inheritance to individual behaviors to the social, built, and natural environment and chemical exposures. It will have sufficient statistical power to examine interactions among these multiple influences, including gene–environment and gene–obesity interactions. A major secondary benefit will derive from the banking of specimens for future analysis