Built-in-self-test of RF front-end circuitry

Fuelled by the ever increasing demand for wireless products and the advent of deep submicron CMOS, RF ICs have become fairly commonplace in the semiconductor market. This has given rise to a new breed of Systems-On-Chip (SOCs) with RF front-ends tightly integrated along with digital, analog and mixed signal circuitry. However, the reliability of the integrated RF front-end continues to be a matter of significant concern and considerable research. A major challenge to the reliability of RF ICs is the fact that their performance is also severely degraded by wide tolerances in on-chip passives and package parasitics, in addition to process related faults. Due to the absence of contact based testing solutions in embedded RF SOCs (because the very act of probing may affect the performance of the RF circuit), coupled with the presence of very few test access nodes, a Built In Self Test approach (BiST) may prove to be the most efficient test scheme. However due to the associated challenges, a comprehensive and low-overhead BiST methodology for on-chip testing of RF ICs has not yet been reported in literature. In the current work, an approach to RF self-test that has hitherto been unexplored both in literature and in the commercial arena is proposed. A sensitive current monitor has been used to extract variations in the supply current drawn by the circuit-under-test (CUT). These variations are then processed in time and frequency domain to develop signatures. The acquired signatures can then be mapped to specific behavioral anomalies and the locations of these anomalies. The CUT is first excited by simple test inputs that can be generated on-chip. The current monitor extracts the corresponding variations in the supply current of the CUT, thereby creating signatures that map to various performance metrics of the circuit. These signatures can then be post-processed by low overhead on-chip circuitry and converted into an accessible form. To be successful in the RF domain any BIST architecture must be minimally invasive, reliable, offer good fault coverage and present low real estate and power overheads. The current-based self-test approach successfully addresses all these concerns. The technique has been applied to RF Low Noise Amplifiers, Mixers and Voltage Controlled Oscillators. The circuitry and post-processing techniques have also been demonstrated in silicon (using the IBM 0.25 micron RF CMOS process). The entire self-test of the RF front-end can be accomplished with a total test time of approximately 30µs, which is several orders of magnitude better than existing commercial test schemes

Small business innovation research program solicitation: Closing date July 16, 1990

This is the eighth annual solicitation by NASA addressed to small business firms, inviting them to submit proposals for research, or research and development, activities in some of the science and engineering areas of interest to NASA. The solicitation describes the Small Business Innovative Research (SBIR) program, identifies eligibility requirements, outlines the required proposal format and content, states proposal preparation and submission requirements, describes the proposal evaluation and award selection process, and provides other information to assist those interested in participating in NASA's SBIR program. It also identifies the technical topics and subtopics for which SBIR proposals are solicited. These cover a broad range of current NASA interests, but do not necessarily include all areas in which NASA plans or currently conducts research. High-risk high pay-off innovations are desired

I the development of a marine seismic recording system II a magnetic survey of the faeroe bank

The first section of the thesis reviews the design of marine seismic refraction systems which have been evolved to enable surveys to be carried out using only one ship. This is followed by a discussion of the design of a specific self-recording sonobuoy which stores the seismic information on magnetic tape, together with the specifications and circuit details of the system built at Durham University. Each buoy incorporates a four track tape recorder which is programmed, using an internal crystal clock, to switch on and off at predetermined intervals. The clock times the seismic arrivals and is periodically synchronised with time on board the shooting ship by the radio transmissions to the buoy. The seismic signal is recorded at two gain levels and there is a facility for wow and flutter compensation. Finally, there is a description of a refraction survey on the Iceland-Faeroe Rise, which regretably culminated in the loss of the buoy units

A transformation grammar-based methodology for housing rehabilitation: meeting contemporary functional and ICT requirements

This research starts from the premise that the future of the real estate market in Portugal will require the rehabilitation of existing residential areas in order to respond to new life-styles and dwelling requirements that have emerged in an era in which information plays a structuring role in society. The goal of this research is the definition of design guidelines and a rehabilitation methodology to support architects involved in the process of adapting existing dwellings, allowing them to balance sustainability requirements and economic feasibility with new dwelling trends such as the incorporation and updating of Information Communication and Automation Technologies and the need to solve emerging conflicts affecting the use of space prompted by the introduction of new functions associated with such technologies. In addition to defining a general methodology applicable to all the building types, the study focuses on a specific type, called “rabo-de-bacalhau” (“cod-tail”), built in Lisbon between 1945 and 1965 for which a specifc methodology has been generated. Both shape grammar and space syntax were used as part of the rehabilitation methodology as tools to identify and encode the principles and rules behind the adaptation of existing houses to new requirements.FCT PhD Gran

SSTAC/ARTS review of the draft Integrated Technology Plan (ITP). Volume 8: Aerothermodynamics Automation and Robotics (A/R) systems sensors, high-temperature superconductivity

Viewgraphs of briefings presented at the SSTAC/ARTS review of the draft Integrated Technology Plan (ITP) on aerothermodynamics, automation and robotics systems, sensors, and high-temperature superconductivity are included. Topics covered include: aerothermodynamics; aerobraking; aeroassist flight experiment; entry technology for probes and penetrators; automation and robotics; artificial intelligence; NASA telerobotics program; planetary rover program; science sensor technology; direct detector; submillimeter sensors; laser sensors; passive microwave sensing; active microwave sensing; sensor electronics; sensor optics; coolers and cryogenics; and high temperature superconductivity

Smart Material Wing Morphing for Unmanned Aerial Vehicles.

Morphing, or geometric adaptation to off-design conditions, has been considered in aircraft design since the Wright Brothers’ first powered flight. Decades later, smooth, bio-mimetic shape variation for control over aerodynamic forces still remains elusive. Unmanned Aerial Vehicles are prime targets for morphing implementation as they must adapt to large changes in flight conditions associated with locally varying wind or large changes in mass associated with payload delivery. The Spanwise Morphing Trailing Edge (SMTE) concept is developed to locally vary the trailing edge camber of a wing or control surface, functioning as a modular replacement for conventional ailerons without altering the wing’s spar box. The SMTE design was realized utilizing alternating active sections of Macro Fiber Composites (MFCs) driving internal elastomeric compliant mechanisms and passive sections of anisotropic, elastomeric skin with tailorable stiffness, produced by additive manufacturing. Experimental investigations of the modular design via a new scaling methodology for reduced-span test articles revealed that increased use of more MFCs within the active section did not increase aerodynamic performance due to asymmetric voltage constraints. The comparative mass and aerodynamic gains for the SMTE concept are evaluated for a representative finite wing as compared with a conventional, articulated flap wing. Informed by a simplistic system model and measured control derivatives, experimental investigations identified a reduction in the adaptive drag penalty up to 20% at off-design conditions. To investigate the potential for augmented aeroelastic performance and actuation range, a hybrid multiple-smart material morphing concept, the Synergistic Smart Morphing Aileron (SSMA), is introduced. The SSMA leverages the properties of two different smart material actuators to achieve performance exceeding that of the constituent materials. Utilizing the relatively higher work density and phase transformation of Shape-Memory Alloys combined with the larger bandwidth and conformal bending of MFCs, the resultant design is demonstrated to achieve the desired goals while providing additional control authority at stall and for unsteady conditions through synergistic use of reflex actuation. These advances highlight and motivate new morphing structures for the growing field of UAVs in which adaptation involves advanced compliance tailoring of complex geometry with synergistic actuation of embedded, smart materials.PhDAerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111533/1/alexmp_1.pd

Spatial and temporal representations for multi-modal visual retrieval

This dissertation studies the problem of finding relevant content within a visual collection according to a specific query by addressing three key modalities: symmetric visual retrieval, asymmetric visual retrieval and cross-modal retrieval, depending on the kind of data to be processed. In symmetric visual retrieval, the query object and the elements in the collection are from the same kind of visual data, i.e. images or videos. Inspired by the human visual perception system, we propose new techniques to estimate visual similarity in image-to-image retrieval datasets based on non-metric functions, improving image retrieval performance on top of state-of-the-art methods. On the other hand, asymmetric visual retrieval is the problem in which queries and elements in the dataset are from different types of visual data. We propose methods to aggregate the temporal information of video segments so that imagevideo comparisons can be computed using similarity functions. When compared in image-to-video retrieval datasets, our algorithms drastically reduce memory storage while maintaining high accuracy rates. Finally, we introduce new solutions for cross-modal retrieval, which is the task in which either the queries or the elements in the collection are non-visual objects. In particular, we study text-image retrieval in the domain of art by introducing new models for semantic art understanding, obtaining results close to human performance. Overall, this thesis advances the state-of-the-art in visual retrieval by presenting novel solutions for some of the key tasks in the field. The contributions derived from this work have potential direct applications in the era of big data, as visual datasets are growing exponentially every day and new techniques for storing, accessing and managing large-scale visual collections are required

Particle size distribution instrument. Topical report 13

The development of an instrument to measure the concentration of particles in gas is described in this report. An in situ instrument was designed and constructed which sizes individual particles and counts the number of occurrences for several size classes. Although this instrument was designed to detect the size distribution of slag and seed particles generated at an experimental coal-fired magnetohydrodynamic power facility, it can be used as a nonintrusive diagnostic tool for other hostile industrial processes involving the formation and growth of particulates. Two of the techniques developed are extensions of the widely used crossed beam velocimeter, providing simultaneous measurement of the size distribution and velocity of articles

Teacher-class, teacher-group and student interactions : opportunities for learning in primary science classrooms

Many studies have investigated learning in science classes, examining various influences on the understandings that students develop. The purpose of this study was to investigate the interactions that took place in upper primary science lessons, and the teacher and student behaviours affected these interactions and the opportunities for learning. The three classes that were selected for the study were similar and the teachers were all experienced primary teachers. The teachers were supplied with a set of science lessons on the topic of electric circuits. The resources included background information for the teachers and suggested activities, demonstrations, analogies and focus questions that the teachers could use to develop scientifically valid understandings. The student activities were designed to allow the students to investigate and solve problems related to electric circuits and to then discuss the activities in their groups to develop understandings. Whole-class discussions were used to further develop the understandings and then the students, in their groups, used their new Knowledge to solve theoretical problems. The data collection was broad to ensure that as much information as possible was obtained. The students participated in pre and posttests, with one group of students from each class also interviewed prior to and alter the series of lessons about their understandings. All the teacher interactions with the class and with groups of students were audio-recorded, and one group of students, the group that was interviewed, was video and audio-recorded. The researcher also attended all the science lessons and recorded anecdotal records of the activities during the lesson, and any blackboard work that occurred. The data analysis examined the types of teacher and student behaviours that occurred; the quantity and types of interactions that occurred in the whole-class and group discussions; the management of the task and behaviours in whole-class and group activities; the way the lesson time was used by the teacher and by the students in their group work; the use and understanding of scientific vocabulary; and the understandings that were developed by the students. The analysis revealed important differences in the teaching behaviours of the three teachers and in the ways that they related to their students. The teachers changed the curriculum materials, sometimes purposefully, but sometimes inadvertently, resulting in changed learning opportunities for the students, and often used scientific terms incorrectly and/or did not explain them. The teachers’ management of time, student behaviour, tasks and discussions affected the flow of lessons and opportunities students had to develop understandings. The students\u27 level of attention and responsibility for task management also varied between students and between the classes. Students\u27 group work skills were generally found to the inadequate to manage group relationships and tasks. Because of the scope of the data, which encompasses many variables, it was not intended nor possible to establish any direct causal relationship between particular teaching/learning variables and the learning outcomes, but it was possible to suggest links between aspects of the learning environment, opportunities for learning and changes in the students\u27 understandings. From the data, specific assertions were generated and these were collated to produce general assertions, which were again aggregated to produce the overarching assertions, the findings of the study. These findings are consistent with those from many previous studies of classroom interactions and behaviours. However, they also indicated that the classroom ethos; the management strategies and styles of the teachers; the teaching style of the teacher; the ways that discussions were conducted; the level of involvement, responsibility and independence of the students; and the way time was used had an impact on the learning opportunities during the lessons and the development of acceptable, scientific understandings. This study, which provides an in-depth analysis of the complexity of the teaching-learning process in primary science lessons, offers insights which may be useful in other learning areas, as many of the findings are not specific to the science aspects of the lessons studied