Use of Field Programmable Gate Array Technology in Future Space Avionics

Fulfilling NASA's new vision for space exploration requires the development of sustainable, flexible and fault tolerant spacecraft control systems. The traditional development paradigm consists of the purchase or fabrication of hardware boards with fixed processor and/or Digital Signal Processing (DSP) components interconnected via a standardized bus system. This is followed by the purchase and/or development of software. This paradigm has several disadvantages for the development of systems to support NASA's new vision. Building a system to be fault tolerant increases the complexity and decreases the performance of included software. Standard bus design and conventional implementation produces natural bottlenecks. Configuring hardware components in systems containing common processors and DSPs is difficult initially and expensive or impossible to change later. The existence of Hardware Description Languages (HDLs), the recent increase in performance, density and radiation tolerance of Field Programmable Gate Arrays (FPGAs), and Intellectual Property (IP) Cores provides the technology for reprogrammable Systems on a Chip (SOC). This technology supports a paradigm better suited for NASA's vision. Hardware and software production are melded for more effective development; they can both evolve together over time. Designers incorporating this technology into future avionics can benefit from its flexibility. Systems can be designed with improved fault isolation and tolerance using hardware instead of software. Also, these designs can be protected from obsolescence problems where maintenance is compromised via component and vendor availability.To investigate the flexibility of this technology, the core of the Central Processing Unit and Input/Output Processor of the Space Shuttle AP101S Computer were prototyped in Verilog HDL and synthesized into an Altera Stratix FPGA

In-Home Counseling for Young Children Living in Poverty: An Exploration of Counseling Competencies

Home-based counseling is increasingly an alternative mode of providing counseling services for children and families, reduces barriers to accessing traditional counseling services, and has also been shown to be effective. As such, the purpose of this qualitative study was to explore and describe the competencies needed to provide such counseling services. This study yielded five categories of competencies—necessary knowledge sets, case conceptualization, counseling behaviors, flexibility in session, and professional dispositions and behaviors. We also outline implications for counseling practice, counselor education, and public policy

The Home Government of India, 1834-53.

This thesis is a study of the impact of British politics on Indian policy during the twenty year period which followed the renewal of the East India Company's Charter in 1833. The view taken is that the policy of the Home Government of India is inseparable from that of the Ministry generally. Within the 'dual' system of the Home Government the Cabinet Minister for India, the President of the Board of Control, is seen to exercise a dominant role while the Court of Directors of the East India Company, a body of Indian experience, act, with a varying degree of success, the part of a check upon his authority. The changes centering around the Reform of Parliament in 1832 redefined the basis of British politics and gave rise to a "precocious development of party politics" with an accompanying alternation of party governments which continued throughout the twenty years under review. Owing to this development two sets of Indian policy emerge during this period, one proper to the years of Whig administration and one associated with those of Sir Robert Peel's Conservative Ministries. The pervasive influence of Ministry and party extends even to the highest offices in the Indian administration at this time for, starting with Auckland, the Governors General are selected from their respective Cabinets and go out to India in the full knowledge of the views of the British Government. The determining role of British history on Indian development is therefore observed as it acts through the work of the Cabinet Minister for India in association with the Ministry's appointee, the Governor General, The twenty years over which this study extends provide a sufficiently long time to trace the development of significant aspects of Indian policy in four principal areas, those of finance, foreign affairs, the native states and law reform

Tame kernels and further 4-rank densites

There has been recent progress on computing the 4-rank of the tame kernel $K_2(\mathcal{O}_F)$ for $F$ a quadratic number field. For certain quadratic number fields, this progress has led to "density results'' concerning the 4-rank of tame kernels. These results were first mentioned in \cite{CH} and proven in \cite{RO}. In this paper, we consider some additional quadratic number fields and obtain further density results of 4-ranks of tame kernels. Additionally, we give tables which might indicate densities in some generality.Comment: 20 page

On Gras conjecture for imaginary quadratic fields

In this paper we extend methods of Rubin to prove the Gras conjecture for abelian extensions of a given imaginary quadratic field k and prime numbers p which divide the number of roots of unity in k.Comment: accepted for publication in Canadian Mathematical Bulleti

Value of toe pulse waves in addition to systolic pressures in the assessment of the severity of peripheral arterial disease and critical limb ischemia

AbstractPurpose: Although pressure measurements are useful in the assessment of the severity of the arterial obstruction, they do not completely identify limbs with and without critical limb ischemia. Our objective was to test whether addition of the measurements of toe pulse waves (PW), which depend on distal perfusion, to pressure measurements could improve the determination of the severity of arterial disease and the presence of critical limb ischemia.Methods: We measured toe pressure (TSP) and ankle/brachial index (ABI) and recorded PW with photoplethysmography in 358 limbs of 182 patients.Results: TSP, ABI, and PW amplitude were lower in 67 limbs with rest pain, skin lesions, or both, with mean differences of 29 mm Hg, 0.12, and 16 mm, respectively ( p < 0.01). Similarly, in the subgroup of 107 limbs with TSP ≤30 mm Hg, TSP, and PW amplitude, but not ABI, were lower in 53 limbs with rest pain, skin lesions, or both, with mean differences of 10 mm Hg and 7 mm ( p < 0.01). Multiple logistic regression showed that after controlling was done for TSP and ABI, the odds ratio for the presence of rest pain, skin lesions, or both associated with PW amplitude ≤4 mm was 4.3 (95% confidence interval 1.7, 11.0; p < 0.01). In the subgroup with TSP ≤30 mm Hg, this odds ratio was 3.5 (95% confidence interval 1.0, 11.6; p < 0.05).Conclusions: The findings indicate that addition of PW recording to pressure measurements is likely to increase the accuracy of assessment for critical limb ischemia. (J Vasc Surg 1996;24:258-65.