Dual-coding representations for robot vision programming in Tekkotsu

We describe complementary iconic and symbolic representations for parsing the visual world. The iconic pixmap representation is operated on by an extensible set of “visual routines” (Ullman, 1984; Forbus et al., 2001). A symbolic representation, in terms of lines, ellipses, blobs, etc., is extracted from the iconic encoding, manipulated algebraically, and re-rendered iconically. The two representations are therefore duals, and iconic operations can be freely intermixed with symbolic ones. The dual-coding approach offers robot programmers a versatile collection of primitives from which to construct application-specific vision software. We describe some sample applications implemented on the Sony AIBO. David S. Touretzky is a Research Professor in the Computer Science Department and the Center for the Neural Basis of Cognition at Carnegie Mellon University. He earned his B.A. in Computer Science from Rutgers University in 1978, and his M.S. (1979) and Ph.D. (1984) in Computer Science from Carnegie Mellon. Dr. Touretzky’s research interests are in computational neuroscience, particularly representations of space in the rodent hippocampus and related structures, and high level primitives for robot programming. He is presently developing an undergraduate curriculum in cognitive robotics based on the Tekkotsu software framework described in this article. Neil S. Halelamien earned a B.S. in Computer Science and a B.S. in Cognitive Science at Carnegie Mellon University in 2004, and is currently pursuing his Ph.D. in the Computation & Neural Systems program at the California Institute of Technology. His research interests are in studying vision from both a computational and biological perspective. He is currently using transcranial magnetic stimulation to study visual representations and information processing in visual cortex. Ethan J. Tira-Thompson is a graduate student in the Robotics Institute at Carnegie Mellon University. He earned a B.S. in Computer Science and a B.S. in Human-Computer Interaction in 2002, and an M.S. in Robotics in 2004, at Carnegie Mellon. He is interested in a wide variety of computer science topics, including machine learning, computer vision, software architecture, and interface design. Ethan’s research has revolved around the creation of the Tekkotsu framework to enable the rapid development of robotics software and its use in education. He intends to specialize in mobile manipulation and motion planning for the completion of his degree. Jordan J. Wales is completing a Master of Studies in Theology at the University of Notre Dame. He earned a B.S. in Engineering (Swarthmore College, 2001), an M.Sc. in Cognitive Science (Edinburgh, UK, 2002), and a Postgraduate Diploma in Theology (Oxford, UK, 2003). After a year as a graduate research assistant in Computer Science at Carnegie Mellon, he entered the master’s program in Theology at Notre Dame and is now applying to doctoral programs. His research focus in early and medieval Christianity is accompanied by an interest in medieval and modern philosophies of mind and their connections with modern cognitive science. Kei Usui is a masters student in the Robotics Institute at Carnegie Mellon University. He earned his B.S. in Physics from Carnegie Mellon University in 2005. His research interests are reinforcement learning, legged locomotion, and cognitive science. He is presently working on algorithms for humanoid robots to maintain balance against unexpected external forces.     

Effect of bismuth–tin alloy particle diameter on bonding strength of copper nanoparticles/bismuth–tin solder hybrid joints

The effect of the diameter of Bi–Sn alloy particles on the bonding strength of hybrid joints formed between SiC chips and direct-bonded copper (DBC) plates using a Cu nanoparticles/Bi–Sn solder was studied. The bonding strength was the highest at 40 MPa for a Bi–Sn alloy particle diameter of 10 µm. Further, the bonding strength was dependent on the area of the bonding layer adhering to the SiC-side fracture surface, as determined by the die-shear test. Ni, which was deposited on the SiC chips and DBC plates before the bonding process, remained near the interfacial area of the bonding layer in the joints formed using the 5 µm particles. In contrast, Ni diffused all over the bonding area, with the exception of the interfacial area where Cu–Sn compounds were formed, in the joints produced using the larger alloy particles. The distribution of Sn in the bonding layer became more uniform and the segregation of Bi at the interface became more pronounced as the particle size was reduced. Further, with an increase in the particle size, the Ag layers deposited on the surfaces of the SiC chips and DBC plates diffused into the bonding layer after the first firing step at 473 K, which was performed before the secondary firing step at 623 K. These results imply that the diameter of the Bi–Sn solder particles in hybrid joints affects the interfacial structure, as it governs the wetting behavior of the Bi–Sn solder and hence has a determining effect on the bonding strength.     

Highly conductive SnO2 thin films for flat‐panel displays

Abstract— SnO₂ is considered to be a promising alternative material for indium tin oxide (ITO), which is used for thin‐film transparent electrodes in flat‐panel displays (FPDs) and is facing a serious indium depletion problem. However, annealing processes in the manufacture of plasma‐display panels (PDPs), which are major FPDs, cause high resistivity in SnO₂ films. To obtain lower resistivity after the annealing processes, the relationship between deposition conditions and resistivity and the influences of annealing on resistivity, both theoretically and experimentally, were investigated. As a solution, a method involving the formation of a coating of SiO₂ on SnO₂ is proposed, and a SnO₂ resistivity as low as 6.60 × 10^?5 Ω‐m was obtained after annealing.     

ERG campimetry using a multi-input stimulation technique for mapping of retinal function in the central visual field

The m-sequence stimulation technique that has previously been described allows simultaneous recording of many local electroretinograms (ERGs). For topographical mapping of cone function in the central retina ERG traces from 61 retinal areas were recorded during a 4-min period in 20 normal volunteers and 4 patients with age-related macular degeneration, Stargardt's disease, choroidal atrophy, and polymyalgia associated with visual field loss. The local photopic luminance response was analyzed in each of the 61 areas. In the 2 patients with macular disease central defects were detected, in the remaining patients local defects were found outside the macular region. The method of multifocal ERG recordings provides the possibility of objective testing of visual fields when the outer retinal layers are affected.     

Purification and characterization of chondroitin 4-sulfotransferase from the culture medium of a rat chondrosarcoma cell line

Chondroitin 4-sulfotransferase, which transfers sulfate from 3'-phosphoadenosine 5'-phosphosulfate to position 4 of N-acetylgalactosamine in chondroitin, was purified 1900-fold to apparent homogeneity with 6.1% yield from the serum-free culture medium of rat chondrosarcoma cells by affinity chromatography on heparin-Sepharose CL-6B, Matrex gel red A-agarose, 3',5'-ADP-agarose, and the second heparin-Sepharose CL-6B. SDS-polyacrylamide gel electrophoresis of the purified enzyme showed two protein bands. Molecular masses of these protein were 60 and 64 kDa under reducing conditions and 50 and 54 kDa under nonreducing conditions. Both the protein bands coeluted with chondroitin 4-sulfotransferase activity from Toyopearl HW-55 around the position of 50 kDa, indicating that the active form of chondroitin 4-sulfotransferase is a monomer. Dithiothreitol activated the purified chondroitin 4-sulfotransferase. The purified enzyme transferred sulfate to chondroitin and desulfated dermatan sulfate. Chondroitin sulfate A and chondroitin sulfate C were poor acceptors. Chondroitin sulfate E from squid cartilage, dermatan sulfate, heparan sulfate, and completely desulfated N-resulfated heparin hardly served as acceptors of the sulfotransferase. The transfer of sulfate to the desulfated dermatan sulfate occurred preferentially at position 4 of the N-acetylgalactosamine residues flanked with glucuronic acid residues on both reducing and nonreducing sides.     

Cloning and characterization of a novel membrane-associated antigenic protein of Helicobacter pylori

BACKGROUND: The aim of this study was to evaluate the effect of convective [hemodiafiltration (HDF) or hemofiltration (HF)] versus diffusive treatments [hemodialysis (HD)] on end-stage renal disease (ESRD) patient mortality and dialysis-related amyloidosis (DRA) using data from the Lombardy Registry. METHODS: For this purpose, 6, 444 patients (aged 56.4 +/- 15.6 years, females 39.5%, diabetics 10. 6%) who started renal replacement therapy (RRT) on HD, HDF, or HF between 1983 and 1995 were considered. A total of 1,082 patients were treated with HDF or HF (first choice in the case of 188), with a median follow-up of 29.7 months. The median follow-up of the 6,298 patients on HD (first choice in the case of 6256) was 22.4 months. The time of survival on dialysis to carpal tunnel syndrome (CTS) surgery was evaluated as a hard marker of DRA morbidity. Survival was compared by means of the Cox proportional regression hazards model, using CTS surgery and all deaths as events for morbidity and mortality, respectively. Explanatory covariates were age, gender, and comorbidities; dialysis modality was tested as a time-dependent covariate. RESULTS: The relative risk (RR) for CTS surgery was significantly higher in older patients [RR = 1.04 per year of age on admission to RRT, 95% confidence interval (CI) 1.02 to 1.06; P = 0. 0001], in diabetics (RR = 2.63, 95% CI 1.30 to 5.31; P = 0.0007), and in patients with heart disease (RR = 5.36, 95% CI 2.27 to 12.68 P = 0.0001). Adjusting for age and diabetic status, the RR for CTS surgery was 42% lower in the patients treated with HDF or HF (RR = 0. 58, 95% CI 0.35 to 0.95, P = 0.03). The RR for mortality, adjusted for age, gender, and comorbidities, was 10% lower in patients treated with HDF or HF (RR = 0.90, 95% CI 0.76 to 1.06; P = NS). CONCLUSION: These results support the hypothesis that convective treatments are associated with a nonsignificant trend toward better survival and significantly delay the need for CTS surgery. An older age and the presence of diabetes and heart disease are other important risk factors for CTS surgery. These results could have an important clinical impact given the relevance of DRA in dialysis patient morbidity.     

Rate of nitrogen desorption from CaO-Al2O3 melts to gas phase

There is a limit to lowering the nitrogen level in steel, because of pickup from the atmosphere during and after degassing. Therefore, the nitride capacity of various fluxes has been measured in order to examine the possibility of nitrogen removal by using slag. It is necessary to take into account the nitrogen reaction rate between the gas and slag phases for the efficient removal of nitrogen in practical steelmaking processes. In this study, the nitrogen desorption rate from CaO-Al₂O₃ melts to gas phase has been examined at 1873 K. The mass-transfer coefficient of nitrogen in the melts increases as the CaO content increases, and the dependence is related to the viscosity of the melts. The reaction-rate constant of nitrogen desorption is found to be proportional to the 3/2 power of the oxygen partial pressure and increases as the CaO content increases under constant oxygen partial pressure.     

Counter-Rotating Type Tidal Stream Power Unit Boarded on Pillar （Perform- ances and Flow Conditions of Tandem Propellers）

The authors have invented the unique counter-rotating type tidal stream power unit composed of the tandem pro- peUers and the double rotational armature type peculiar generator without the traditional stator. The front and the rear propellers counter-drive the inner and the outer armatures of the peculiar generator, respectively. The unit has the fixftful advantages that not only the output is sufficiently higher without supplementary equipment such as a gearbox, but also the rotational moment hardly act on the pillar because the rotational torque of both propel- lers/armatures are counter-balanced in the unit. This paper discusses experimentally the performances of the power unit and the effects of the propeller rotation on the sea surface. The axial force acting on the pillar in- creases naturally with the increase of not only the stream velocity but also the drag of the tandem propellers. Be- sides, the force vertical to the stream also acts on the pillar, which is induced from the Karman vortex street and the dominant frequencies appear owing to the front and the rear propeller rotations. The propeller rotating in close to the sea surface brings the abnormal wave and the amplitude increases as the stream velocity is faster and/or the drag is stronger.