Principal Solutions Revisited

The main objective of this paper is to identify principal solutions associated with Sturm-Liouville operators on arbitrary open intervals $(a,b) \subseteq \mathbb{R}$, as introduced by Leighton and Morse in the scalar context in 1936 and by Hartman in the matrix-valued situation in 1957, with Weyl-Titchmarsh solutions, as long as the underlying Sturm-Liouville differential expression is nonoscillatory (resp., disconjugate or bounded from below near an endpoint) and in the limit point case at the endpoint in question. In addition, we derive an explicit formula for Weyl-Titchmarsh functions in this case (the latter appears to be new in the matrix-valued context).Comment: 27 pages, expanded Sect. 2, added reference

Design and synthesis of a high-performance, hyper-programmable DSP on an FPGA

In the field of high performance digital signal processing, DSPs and FPGAs provide the most flexibility. Due to the extensive customization available on FPGAs, DSP algorithm implementation on an FPGA exhibits an increased development time over programming a processor. Because of this, traditional DSPs typically yield a faster time to market than an FPGA design. However, it is often desirable to have the ASIC-like performance that is attainable through the additional customization and parallel computation available through an FPGA. This can be achieved through the class of processors known as hyper-programmable DSPs. A hyper-programmable DSP is a DSP in which multiple aspects of the architecture are programmable. This thesis contributes such a DSP, targeted for high-performance and realized in hardware using an FPGA. The design consists of both a scalar datapath and a vector datapath capable of parallel operations, both of which are extensively customizable. To aid in the design of the datapaths, graphical tools are introduced as an efficient way to modify the design. A tool was also created to supply a graphical interface to help write instructions for the vector datapath. Additionally, an adaptive assembler was created to convert assembly programs to machine code for any datapath design. The resulting design was synthesized for a Cyclone III FPGA. The synthesis resulted in a design capable of running at 135MHz with 61% of the logic used by processing elements. Benchmarks were run on the design to evaluate its performance. The benchmarks showed similar performance between the proposed design and commercial DSPs for the simple benchmarks but significant improvement for the more complex ones

Alien Registration- Nichols, Stephen C. (Fort Fairfield, Aroostook County)

https://digitalmaine.com/alien_docs/36445/thumbnail.jp

Learning by building digital libraries

The implications of using digital library software in educational contexts, for both students and software developers, are discussed using two case studies of students building digital libraries

Permutation Inference for Canonical Correlation Analysis

Canonical correlation analysis (CCA) has become a key tool for population neuroimaging, allowing investigation of associations between many imaging and non-imaging measurements. As other variables are often a source of variability not of direct interest, previous work has used CCA on residuals from a model that removes these effects, then proceeded directly to permutation inference. We show that such a simple permutation test leads to inflated error rates. The reason is that residualisation introduces dependencies among the observations that violate the exchangeability assumption. Even in the absence of nuisance variables, however, a simple permutation test for CCA also leads to excess error rates for all canonical correlations other than the first. The reason is that a simple permutation scheme does not ignore the variability already explained by previous canonical variables. Here we propose solutions for both problems: in the case of nuisance variables, we show that transforming the residuals to a lower dimensional basis where exchangeability holds results in a valid permutation test; for more general cases, with or without nuisance variables, we propose estimating the canonical correlations in a stepwise manner, removing at each iteration the variance already explained, while dealing with different number of variables in both sides. We also discuss how to address the multiplicity of tests, proposing an admissible test that is not conservative, and provide a complete algorithm for permutation inference for CCA.Comment: 49 pages, 2 figures, 10 tables, 3 algorithms, 119 reference

Step Integration to Taurus First Flight Payload Launch Processing

The first flight of the Orbital Sciences Corp. (OSC) TAURUS launch vehicle is with a space vehicle developed by TRW and DSI under the Air Force Space Test Experiment Program (STEP) that contains several scientific experiments. The experiments have a demanding cleanliness requirement; the satellite requires status monitoring and battery maintenance during launch operations. OSC developed the TAURUS launch vehicle in response to the Advanced Research Project Agency (ARPA) Standard Small Launch Vehicle (SSLV) program. The Taurus system is composed of a flight vehicle and ground support equipment designed for easy transportability and rapid setup and launch on an unimproved concrete pad. TRW provides system engineering on the STEP program, and DSI designed and built the STEP spacecraft. The spacecraft is an evolutionary design based on previous DSI satellite designs. A TRW propulsion system provides orbital adjustment capability. The space vehicle is approximately 36 in diameter, 72 high and weighs almost 1100 pounds when in flight configuration. The challenge was to maintain the requirements in a low cost environment with minimal support from an established infrastructure. This was achieved by the process of encapsulating the satellite in the fairing in a clean room before transport and mate to the launch vehicle. Rehearsals were held at the OSC facility in Arizona in November 1992 and February 1993, and at Vandenberg AFB, CA in June 1993 to develop the procedures necessary for mission success. The TAURUS initial launch capability is planned for November 1993

Successful Networking Can Lead to Usable Products and Learning for All

Networking can increase the usefulness of knowledge and inform the practices of all partners involved. These relationships can be kept through reciprocity and constant interaction between all stakeholders and researchers. Two key outcomes from this process are the creation of useable content and new learning from others.York’s Knowledge Mobilization Unit provides services and funding for faculty, graduate students, and community organizations seeking to maximize the impact of academic research and expertise on public policy, social programming, and professional practice. It is supported by SSHRC and CIHR grants, and by the Office of the Vice-President Research & Innovation. [email protected] www.researchimpact.c

Chemical Release Observation Program Description and Flight Results

The Chemical Release Observation (CRO) program developed three small satellites that were deployed from the Shuttle on flight STS-39. These were small experimental satellites built with a minimum of paperwork. While meeting all the necessary NASAISTS requirements. Each satellite contained a chemical (either hydrazine or an oxidizer) which was released on ground command. The satellites were approximately 18 diameter and 31 high. and weighed 160 to 195 pounds when loaded. The satellites carried 60 pounds of MMH (MonoMethyl Hydrazine), 52 pounds of UDMH (Unsymmetrical DiMethyl Hydrazine) and 11 pounds of N10 4 (Nitrogen Tetroxide). The satellites were designed and built by DS1, under a contract with Los Alamos National Laboratory, with funding provided by SDIO. Environmental and operational testing was performed at Goddard Space Flight Center, Los Alamos National Laboratory and Vandenberg AFB. Through a long and arduous process, they were fully qualified for use on the Shuttle. The satellites were launched on board Space Shuttle DISCOVERY on April 28, 1991 as a part of the IBSS program. The satellites were deployed from the Shuttle, one at a time, and all three were successfully commanded from Vandenberg AFB to release its chemical at the scheduled time