Space environment robot vision system

A prototype twin-camera stereo vision system for autonomous robots has been developed at Goddard Space Flight Center. Standard charge coupled device (CCD) imagers are interfaced with commercial frame buffers and direct memory access to a computer. The overlapping portions of the images are analyzed using photogrammetric techniques to obtain information about the position and orientation of objects in the scene. The camera head consists of two 510 x 492 x 8-bit CCD cameras mounted on individually adjustable mounts. The 16 mm efl lenses are designed for minimum geometric distortion. The cameras can be rotated in the pitch, roll, and yaw (pan angle) directions with respect to their optical axes. Calibration routines have been developed which automatically determine the lens focal lengths and pan angle between the two cameras. The calibration utilizes observations of a calibration structure with known geometry. Test results show the precision attainable is plus or minus 0.8 mm in range at 2 m distance using a camera separation of 171 mm. To demonstrate a task needed on Space Station Freedom, a target structure with a movable I beam was built. The camera head can autonomously direct actuators to dock the I-beam to another one so that they could be bolted together

Vertical Variation in Groundwater Chemistry Inferred from Fluid Specific-Conductance Well Logging of the Snake River Plain Basalt Aquifer, Idaho National Engineering Laboratory, Southeastern Idaho

Well logging of electrical fluid specific conductance (Cs) shows that permeable zones yielding ground water to intrawell flows and the water columns in some wells at INEL have highly different chemistry, with as much as a two-fold variation in Cs). This suggests that dedicated pump sampling of ground water in the aquifer may not be representative of the chemistry of the waste plumes migrating southwest of the nuclear facilities. Natural background Cs in basalt-aquifer ground water of this part of the Snake River Plain aquifer is less than 325µS/cm (microSiemans/cm), and total dissolved solids in mg/L units, (TDS) ≈ 0.6Cs). This relationship underestimates IDS for waters with chemical waste. when Cs) is above 800 µS/cm. At well 59 near the ICPP water of 1115 µS/cm (≈670+ mg/L TDS) enters the well from a permeable zone between 521 and 537 ft depth; the zone being 60 ft below the water level and water of 550 µS/cm. At the time of logging (9/14/93) the 1115µS/cm water was flowing down the well, mixing with less concentrated waters and exiting at 600 or 624-ft depth. Waste water disposed of down the injection well at ICPP until 1984 was estimated to have a Cs) of 1140 µS/cm, identical to the water detected in logging. At well OW2, the highest Cs) water (760µS/cm) is in the upper 30 feet of the water column: water from two flow zones below have different chemistry with lower values of Cs. The Site 14 well and USGS 83 show uniform values throughout the water column. The water column in Site 14 is dominated by a downward flow of 50 gal/min probably entering between 475 and 500 ft depth and exiting near the bottom of the well at 700 ft depth. Impeller flowmeter and precision temperature logging are used to define and quantify temperature variations and intrawell flows. At well 59 (depth=657 ft) and OW2 (depth=996 ft), are downward decreasing temperatures in the bottom zones of no flow, suggesting that major flow zones lie beneath the deepest parts of these wells

Integrating Functional Synthesis

Design couples synthesis and analysis in iterative cycles, alternatively generating solutions, and evaluating their validity. The accuracy and depth of evaluation has increased markedly because of the availability of powerful simulation tools and the development of domain-specific knowledge bases. Efforts to extend the state of the art in evaluation have unfortunately been carried out in stovepipe fashion, depending on domain-specific views both of function and of what constitutes “good” design. Although synthesis as practiced by humans is an intentional process that centers on the notion of function, computational synthesis often eschews such intention for sheer permutation. Rather than combining synthesis and analysis to form an integrated design environment, current methods focus on comprehensive search for solutions within highly circumscribed subdomains of design. This paper presents an overview of the progress made in representing design function across abstraction levels proven useful to human designers. Through an example application in the domain of mechatronics, these representations are integrated across domains and throughout the design process

Computational Aeroheating Predictions for X-34

Radiative equilibrium surface temperatures, heating rates, streamlines, surface pressures, and flow-field features as predicted by the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) are presented for the X-34 Technology Demonstrator. Results for two trajectory points corresponding to entry peak heating and two control surface deflections are discussed. This data is also discussed in the context of Thermal Protection System (TPS) design issues. The work presented in this report is part of a larger effort to define the X-34 aerothermal environment, including the application of engineering codes and wind-tunnel studies

Sketch-To-Solution: An Exploration of Viscous CFD with Automatic Grids

Numerical simulation of the Reynolds-averaged NavierStokes (RANS) equations has become a critical tool for the design of aerospace vehicles. However, the issues that affect the grid convergence of three dimensional RANS solutions are not completely understood, as documented in the AIAA Drag Prediction Workshop series. Grid adaption methods have the potential for increasing the automation and discretization error control of RANS solutions to impact the aerospace design and certification process. The realization of the CFD Vision 2030 Study includes automated management of errors and uncertainties of physics-based, predictive modeling that can set the stage for ensuring a vehicle is in compliance with a regulation or specification by using analysis without demonstration in flight test (i.e., certification or qualification by analysis). For example, the Cart3D inviscid analysis package has automated Cartesian cut-cell gridding with output-based error control. Fueled by recent advances in the fields of anisotropic grid adaptation, error estimation, and geometry modeling, a similar work flow is explored for viscous CFD simulations; where a CFD application engineer provides geometry, boundary conditions, and flow parameters, and the sketch-to-solution process yields a CFD simulation through automatic, error-based, grid adaptation

Citrus Varieties for the Lower Rio Grande Valley.

36 p

ASSEMBLAGE ORGANIZATION OF SURFACE-ACTIVE ARTHROPODS ALONG HORIZONTAL MOISTURE GRADIENTS IN A COASTAL SONORAN DESERT ECOSYSTEM

Examinamos las diferencias a corto plazo en la organización de las comunidades de artrópodos activos en la superficie del suelo en una porción restringida del ecosistema de dunas cerca de Puerto Peñasco, Sonora, México. Para probar la hipótesis de que el gradiente de humedad del suelo influye en tal organización, se estabecieron tres transectos de 32 m en dirección oeste hacia la costa f) área de estero, 2) estanque de agua salada, y 3) área intermedia de desierto seco (control). El gradiente de humedad varió en el estero y estanque de 15% y 11% a <1% respectivamente, mientras que la humedad del suelo en la área control fue de <1% (valores promedio a 15 cm de profundidad). Cuatro lotes, proporcionalmente espaciados de 3 x 7 m a lo largo del transecto con trampas "pitfair capturaron artrópodos continuamente por períodos de 12 horas, el número de trampas fue ocho en el estero, ocho en el estanque y seis en el control. Se capturaron 558 artrópodos pertenecientes a 50 especies, se excluyeron las numerosas hormigas del género Solenopsis. El análisis de "rarefaction" con 80 como tamaño de muestra, mostró valores de 27 en el estero, 21.5 en el estanque y 18 para el sitio de control, cuando se eliminó el efecto de pantano de Uca ¡atimanus (cangrejo que fue dominante en el estero y ausente en los otros dos sitios). los artrópodos, excluyendo cangrejos, fueron doblemente abundantes en el estero durante el día y cuatro veces más abundantes en la noche que en los otros dos sitios durante el día. la proporción carnívoros-detritívoros en los tres sitios fue aproximadamente 2:1 (estero), 1:1 (estanque) y 1:2 (control). El valor de similitud (modificado de Hill E5) sin Uca fue similar en todos los sitios; sin embargo, grandes valores en diversidad (Hill N2) confirman la presencia de numerosas especies en el estero (escarabajos Carabidae y arañas lycosídae). No se encontró relación significativa entre el porcentaje de cobertura vegetal y la densidad de artrópodos capturados. la medida del valor beta-diversidad (coeficiente de comunidad de S^rensen) reafirma la particularidad de la organización en el estero. Nuestra hipótesis inicial fue parcial­ mente apoyada porque la diferencia de especies, abundancia de individuos y proporción carnívoros-detritívoros tendió a incrementarse con el gradiente de humedad

Gene expression and pathway analysis of ovarian cancer cells selected for resistance to cisplatin, paclitaxel, or doxorubicin

<p>Abstract</p> <p>Background</p> <p>Resistance to current chemotherapeutic agents is a major cause of therapy failure in ovarian cancer patients, but the exact mechanisms leading to the development of drug resistance remain unclear.</p> <p>Methods</p> <p>To better understand mechanisms of drug resistance, and possibly identify novel targets for therapy, we generated a series of drug resistant ovarian cancer cell lines through repeated exposure to three chemotherapeutic drugs (cisplatin, doxorubicin, or paclitaxel), and identified changes in gene expression patterns using Illumina whole-genome expression microarrays. Validation of selected genes was performed by RT-PCR and immunoblotting. Pathway enrichment analysis using the KEGG, GO, and Reactome databases was performed to identify pathways that may be important in each drug resistance phenotype.</p> <p>Results</p> <p>A total of 845 genes (p < 0.01) were found altered in at least one drug resistance phenotype when compared to the parental, drug sensitive cell line. Focusing on each resistance phenotype individually, we identified 460, 366, and 337 genes significantly altered in cells resistant to cisplatin, doxorubicin, and paclitaxel, respectively. Of the 845 genes found altered, only 62 genes were simultaneously altered in all three resistance phenotypes. Using pathway analysis, we found many pathways enriched for each resistance phenotype, but some dominant pathways emerged. The dominant pathways included signaling from the cell surface and cell movement for cisplatin resistance, proteasome regulation and steroid biosynthesis for doxorubicin resistance, and control of translation and oxidative stress for paclitaxel resistance.</p> <p>Conclusions</p> <p>Ovarian cancer cells develop drug resistance through different pathways depending on the drug used in the generation of chemoresistance. A better understanding of these mechanisms may lead to the development of novel strategies to circumvent the problem of drug resistance.</p