5,398 research outputs found

    SLS-PLAN-IT: A knowledge-based blackboard scheduling system for Spacelab life sciences missions

    Get PDF
    The primary scheduling tool in use during the Spacelab Life Science (SLS-1) planning phase was the operations research (OR) based, tabular form Experiment Scheduling System (ESS) developed by NASA Marshall. PLAN-IT is an artificial intelligence based interactive graphic timeline editor for ESS developed by JPL. The PLAN-IT software was enhanced for use in the scheduling of Spacelab experiments to support the SLS missions. The enhanced software SLS-PLAN-IT System was used to support the real-time reactive scheduling task during the SLS-1 mission. SLS-PLAN-IT is a frame-based blackboard scheduling shell which, from scheduling input, creates resource-requiring event duration objects and resource-usage duration objects. The blackboard structure is to keep track of the effects of event duration objects on the resource usage objects. Various scheduling heuristics are coded in procedural form and can be invoked any time at the user's request. The system architecture is described along with what has been learned with the SLS-PLAN-IT project

    Solid-state dye-sensitized solar cells based on ZnO nanoparticle and nanorod array hybrid photoanodes

    Get PDF
    The effect of ZnO photoanode morphology on the performance of solid-state dye-sensitized solar cells (DSSCs) is reported. Four different structures of dye-loaded ZnO layers have been fabricated in conjunction with poly(3-hexylthiophene). A significant improvement in device efficiency with ZnO nanorod arrays as photoanodes has been achieved by filling the interstitial voids of the nanorod arrays with ZnO nanoparticles. The overall power conversion efficiency increases from 0.13% for a nanorod-only device to 0.34% for a device with combined nanoparticles and nanorod arrays. The higher device efficiency in solid-state DSSCs with hybrid nanorod/nanoparticle photoanodes is originated from both large surface area provided by nanoparticles for dye adsorption and efficient charge transport provided by the nanorod arrays to reduce the recombinations of photogenerated carriers

    Effects of Self-Monitoring Intervention on Independent Completion of a Daily Living Skill for Children with Autism Spectrum Disorders in China

    Get PDF
    The purpose of this study was to investigate the effects of a self-monitoring intervention on the independent completion of dishwashing for three boys with autism (age 6, 7, and 8) in China. The self-monitoring intervention included visual task analysis, in vivo modeling, self-recording, video self-feedback, and reinforcement. A multiple probe across subjects design was used. Prior to the study, the children had limited or no dishwashing skills, nor did they receive any training on self-monitoring. All three children acquired dishwashing and performed the task independently without supervision one week after the intervention. Their parents were very satisfied with this intervention

    N-Ethyl-3,5-dinitro­benzamide

    Get PDF
    In the title mol­ecule, C9H9N3O5, the dihedral angle between the mean planes of the amide group and the benzene ring is 31.24 (14)°. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules to form one-dimensional chains propagating in [100]

    Numerical earthquake models of the 2013 Nantou, Taiwan, earthquake series: Characteristics of source rupture processes, strong ground motions and their tectonic implication

    Get PDF
    On 27 March and 2 June 2013, two large earthquakes with magnitudes of ML 6.2 and ML 6.5, named the Nantou earthquake series, struck central Taiwan. These two events were located at depths of 15–20 km, which implied that the mid-crust of central Taiwan is an active seismogenic area even though the subsurface structures have not been well established. To determine the origins of the Nantou earthquake series, we investigated both the rupture processes and seismic wave propagations by employing inverse and forward numerical simulation techniques. Source inversion results indicated that one event ruptured from middle to shallow crust in the northwest direction, while the other ruptured towards the southwest. Simulations of 3-D wave propagation showed that the rupture characteristics of the two events result in distinct directivity effects with different amplified shaking patterns. From the results of numerical earthquake modeling, we deduced that the occurrence of the Nantou earthquake series may be related to stress release from the easternmost edge of a preexistent strong basement in central Taiwan

    N,4-Dimethyl­benzamide

    Get PDF
    In the crystal of the title compound, C9H11NO, mol­ecules are connected via inter­molecular N—H⋯O hydrogen bonds, forming a one-dimensional network in the b-axis direction. The dihedral angle between the amide group and the benzyl ring is 13.8 (2)°

    Causal Evidence for the Role of Specific GABAergic Interneuron Types in Entorhinal Recruitment of Dentate Granule Cells

    Get PDF
    The dentate gyrus (DG) is the primary gate of the hippocampus and controls information flow from the cortex to the hippocampus proper. To maintain normal function, granule cells (GCs), the principal neurons in the DG, receive fine- tuned inhibition from local-circuit GABAergic inhibitory interneurons (INs). Abnormalities of GABAergic circuits in the DG are associated with several brain disorders, including epilepsy, autism, schizophrenia, and Alzheimer disease. Therefore, understanding the network mechanisms of inhibitory control of GCs is of functional and pathophysiological importance. GABAergic inhibitory INs are heterogeneous, but it is unclear how individual subtypes contribute to GC activity. Using cell-type-specific optogenetic perturbation, we investigated whether and how two major IN populations defined by parvalbumin (PV) and somatostatin (SST) expression, regulate GC input transformations. We showed that PV-expressing (PV+) INs, and not SST- expressing (SST+) INs, primarily suppress GC responses to single cortical stimulation. In addition, these two IN classes differentially regulate GC responses to θ and γ frequency inputs from the cortex. Notably, PV+ INs specifically control the onset of the spike series, whereas SST+ INs preferentially regulate the later spikes in the series. Together, PV+ and SST+ GABAergic INs engage differentially in GC input-output transformations in response to various activity patterns
    corecore