Hardware verification at Computational Logic, Inc.

The following topics are covered in viewgraph form: (1) hardware verification; (2) Boyer-Moore logic; (3) core RISC; (4) the FM8502 fabrication, implementation specification, and pinout; (5) hardware description language; (6) arithmetic logic generator; (7) near term expected results; (8) present trends; (9) future directions; (10) collaborations and technology transfer; and (11) technology enablers

Robust Trajectory Planning for Autonomous Parafoils under Wind Uncertainty

A key challenge facing modern airborne delivery systems, such as parafoils, is the ability to accurately and consistently deliver supplies into di cult, complex terrain. Robustness is a primary concern, given that environmental wind disturbances are often highly uncertain and time-varying, coupled with under-actuated dynamics and potentially narrow drop zones. This paper presents a new on-line trajectory planning algorithm that enables a large, autonomous parafoil to robustly execute collision avoidance and precision landing on mapped terrain, even with signi cant wind uncertainties. This algorithm is designed to handle arbitrary initial altitudes, approach geometries, and terrain surfaces, and is robust to wind disturbances which may be highly dynamic throughout the terminal approach. Explicit, real-time wind modeling and classi cation is used to anticipate future disturbances, while a novel uncertainty-sampling technique ensures that robustness to possible future variation is e ciently maintained. The designed cost-to-go function enables selection of partial paths which intelligently trade o between current and reachable future states. Simulation results demonstrate that the proposed algorithm reduces the worst-case impact of wind disturbances relative to state-of-the-art approaches.Charles Stark Draper Laborator

Induction of humoral immune response to multiple recombinant Rhipicephalus appendiculatus antigens and their effect on tick feeding success and pathogen transmission

BACKGROUND: Rhipicephalus appendiculatus is the primary vector of Theileria parva, the etiological agent of East Coast fever (ECF), a devastating disease of cattle in sub-Saharan Africa. We hypothesized that a vaccine targeting tick proteins that are involved in attachment and feeding might affect feeding success and possibly reduce tick-borne transmission of T. parva. Here we report the evaluation of a multivalent vaccine cocktail of tick antigens for their ability to reduce R. appendiculatus feeding success and possibly reduce tick-transmission of T. parva in a natural host-tick-parasite challenge model. METHODS: Cattle were inoculated with a multivalent antigen cocktail containing recombinant tick protective antigen subolesin as well as two additional R. appendiculatus saliva antigens: the cement protein TRP64, and three different histamine binding proteins. The cocktail also contained the T. parva sporozoite antigen p67C. The effect of vaccination on the feeding success of nymphal and adult R. appendiculatus ticks was evaluated together with the effect on transmission of T. parva using a tick challenge model. RESULTS: To our knowledge, this is the first evaluation of the anti-tick effects of these antigens in the natural host-tick-parasite combination. In spite of evidence of strong immune responses to all of the antigens in the cocktail, vaccination with this combination of tick and parasite antigens did not appear to effect tick feeding success or reduce transmission of T. parva. CONCLUSION: The results of this study highlight the importance of early evaluation of anti-tick vaccine candidates in biologically relevant challenge systems using the natural tick-host-parasite combination

Bringing installation art to reconnaissance to share values and generate action

The English education system has recently seen something of a revival of enthusiasm for the use of research both to develop educational practices and to gather evidence about their effectiveness. These initiatives often present action research as a model of individual problem-solving, which, we argue, communicates a limited conception of action research. In this paper we propose an alternative to this ‘problem-solving’ conception of action research that acknowledges the complex, messy nature of action research through the use of arts installations. Specifically, we present the reconnaissance phase of a project which brought together a partnership comprising a water heritage museum, university staff, teachers and artists. A pedagogical adaptation of contemporary installation art theory and practice fostered the exploration of individual and collective understandings of water, and also established a shared approach to curriculum development and ownership of the project among all participants. We propose that this creative practice enhanced and changed the process of reconnaissance; it allowed the group to establish and share commitments to the value of water conservation and generated a wide range of options for our action research

Cluster structure of 3α + p states in ¹³N

Background: Cluster states in 13N are extremely difficult to measure due to the unavailability of 9B + elastic-scattering data.Purpose: Using -delayed charged-particle spectroscopy of 13O, clustered states in 13N can be populated and measured in the 3⁢+ decay channel.Methods: One-at-a-time implantation and decay of 13O was performed with the Texas Active Target Time Projection Chamber. 149⁢⁢3⁢⁢ decay events were observed and the excitation function in 13N reconstructed.Results: Four previously unknown -decaying excited states were observed in 13N at an excitation energy of 11.3, 12.4, 13.1, and 13.7 MeV decaying via the 3⁢+ channel.Conclusions: These states are seen to have a [9B⁡(g.s)⁢⨂/+ 12 C ⁡(0+2)], [9B⁡(½+)⁢⨂], [9B⁡(⁵⁄₂+)⁢⨂], and [9B⁡(⁵⁄₂+)⁢⨂] structure, respectively. A previously seen state at 11.8 MeV was also determined to have a [+ 12 C ⁡(g.s.)/+ 12C ⁡(0+2)] structure. The overall magnitude of the clustering is not able to be extracted, however, due to the lack of a total width measurement. Clustered states in 13N (with unknown magnitude) seem to persist from the addition of a proton to the highly -clustered 12C . Evidence of the ½+ state in 9B was also seen to be populated by decays from 13N★