CM Technologies (United States)

The functional software components of an autonomous robotic system express behavior via commands to its actuators, based on processed inputs from its sensors; we propose an additional set of "cognitive" capabilities for robotic systems of all types, based on the comprehensive logging of all available data, including sensor inputs, behavioral states, and outputs sent to actuators. A robot should maintain a "sense" of its own (piecewise) continuous existence through time and space; it should in some sense "get a life," providing a level of self-awareness and self-knowledge. Self-awareness includes the ability to survive and work through unexpected power glitches while executing a task or mission. Selfknowledge includes an extensive world model including a model of self and the purpose context in which it is operating (deontics). Our system must support proactive self-test, monitoring, and calibration, and maintain a "personal" health/repair history, supporting system test and evaluation by continuously measuring performance throughout the entire product lifecycle. It will include episodic memory, and a system "lifelog," and will also participate in multiple modes of Human Robotic interaction (HRI).

Maintaining logical consistency in a knowledge base that receives asynchronous events from collaborative agents poses a challenge, due to multiple agent perspectives of the knowledge base. Facades and filters further complicate this problem by distorting the definition of consistent knowledge. Therefore, maintaining logical consistency of the knowledge base requires an infrastructure for handling truth maintenance. This paper presents a generic, object-oriented framework for truth maintenance in collaborative multi-agent systems. The core of the framework is an agent that autonomously reasons on system events, thus guaranteeing the integrity of the knowledge base independent of external agents. Specialization to a particular domain is achieved through the description of tests that verify the consistency of the knowledge base. This paper shows an example of this approach in a real-world, multi-agent system and discusses performance and maintainability in such a system.

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The lifetime of positrons in a lattice is strongly affected by structural defects even if the concentration of the latter is well beyond the limit of detection by classical methods. The lack of a repulsive center in a vacancy acts as a trap for the positron which then annihilates itself with reduced probability due to the lower electron density at this site. The existence of a component longer than the bulk annihilation thus reflects the presence of vacancies. The behavior of this long-lived component in ZrN films sputtered onto stainless steel substrates was monitored over a period of 18 months. During this time, its value decreased steadily by a factor of 2–3 depending on the negative bias used during the sputtering. No significant changes in the color were observed during the measurements. A consistent explanation is the breakup of polyvacancies or voids leading to a higher concentration of monovacancies.

Functional breast imaging using /sup 99m/Tc MIBI is showing that this technique is able to detect cancer with more than 90% specificity. Using a dedicated gamma camera, with the breast under compression, i.e. in similar conditions of mammography, the detection of sub-centimeter cancers can be improved. A number of factors affects the detection of small cancers as: thickness of the breast, distance between tumor and collimator, cardiac activity. Radioactivity emitted from the body can obscure the breast activity mainly due to the large difference on radioactivity concentration. In this work we analyze the intensity and the energy distribution of Compton scattering coming from the breast by a Germanium detector and by a dedicated imager with a small FOV placed in a geometrical condition similar to mammography. In vivo measurements were performed in patients with a breast cancer ranging between 8 mm and 15 mm. Intensity of Compton scattering from 4 to 10 times greater than full energy peak events resulted. Measurements were compared with ones obtained by a phantom simulating the breast without chest activity demonstrating how large is the Compton contribution from the chest.

The effect of yttrium and molybdenum ion implantation on the lattice parameters, residual stress, and strain distribution (integral peak breadth) in TiN coatings made by chemical vapor deposition was studied by glancing incidence x-ray diffraction in Seemann–Bohlin focusing geometry. It was found that there were no changes in the former two, but that the peak breadth was increased, and particularly between the {220} and {222} families of planes. It is considered that this may be due to grain size comminution or the development of a dislocation network down to depths of the order of 0.5 μm, which is well below the depth where the implant resides. The data also indicate that the limit of usefulness of the Seemann–Bohlin geometry is at the lower end of the angles of incidence set here, namely, 2°–3°.

We summarize the computational techniques used in modelling crystal structures. Special attention is paid to energy minimization methodologies and more sophisticated simulated annealing techniques. We describe recent applications to the refinement of the structures of novel microporous catalysts and to the generation of the structures of the polymorphs of TiO 2 .