Graphical models for interactive POMDPs: representations and solutions

We develop new graphical representations for the problem of sequential decision making in partially observable multiagent environments, as formalized by interactive partially observable Markov decision processes (I-POMDPs). The graphical models called interactive influence diagrams (I-IDs) and their dynamic counterparts, interactive dynamic influence diagrams (I-DIDs), seek to explicitly model the structure that is often present in real-world problems by decomposing the situation into chance and decision variables, and the dependencies between the variables. I-DIDs generalize DIDs, which may be viewed as graphical representations of POMDPs, to multiagent settings in the same way that I-POMDPs generalize POMDPs. I-DIDs may be used to compute the policy of an agent given its belief as the agent acts and observes in a setting that is populated by other interacting agents. Using several examples, we show how I-IDs and I-DIDs may be applied and demonstrate their usefulness. We also show how the models may be solved using the standard algorithms that are applicable to DIDs. Solving I-DIDs exactly involves knowing the solutions of possible models of the other agents. The space of models grows exponentially with the number of time steps. We present a method of solving I-DIDs approximately by limiting the number of other agents’ candidate models at each time step to a constant. We do this by clustering models that are likely to be behaviorally equivalent and selecting a representative set from the clusters. We discuss the error bound of the approximation technique and demonstrate its empirical performance.     

An approach to eliminate stepped features in multistage incremental sheet forming process: Experimental and FEA analysis

Incremental sheet forming (ISF) is a recently developed manufacturing technique. In ISF, forming is done by applying deformation force through the motion of Numerically controlled (NC) single point forming tool on the clamped sheet metal blank. Single Point Incremental sheet forming (SPISF) is also known as a die-less forming process because no die is required to fabricate any component by using this process. Now a day it is widely accepted for rapid manufacturing of sheet metal components. The formability of SPISF process improves by adding some intermediate stages into it, which is known as Multi-stage SPISF (MSPISF) process. However during forming in MSPISF process because of intermediate stages stepped features are generated. This paper investigates the generation of stepped features with simulation and experimental results. An effective MSPISF strategy is proposed to remove or eliminate this generated undesirable stepped features.     

Development of real-time reference evapotranspiration at the regional scale using satellite-based observations

Real-time data of reference evapotranspiration (ET₀) at different space-time scales are essential to regional agricultural drought assessment, water accounting at the watershed to basin scale, and provide irrigation advisory to farmers. Here, we present a data-fusion approach that integrates satellite-based insolation product (8 km) from an Indian geostationary satellite (Kalpana-1) sensor (VHRR; Very High Resolution Radiometer) and high-resolution (~ 5 km) short-range weather forecast into an FAO56 model based on the classical Penman–Monteith (P-M) formulation. Five year (2009–2013) mean monthly estimates from the daily ET₀ product over the Indian landmass were found to vary between 10 and 350 mm. It increased from January to May (70–350 mm), followed by a decrease to reach the lowest in November (10–140 mm), thus typically showing unimodal distribution. The comparison of daily space-based and station-based estimates (at six ground stations) produced a root mean square deviation (RMSD) ranging from 21% to 38% for 977 paired data sets with the correlation coefficient (r) varying from 0.32 to 0.82. The error was reduced from 25% to 10% with an increase in ‘r’ from 0.43 to 0.98 for daily to 10 day summation period. Spatial grid-to-grid comparison of monthly ET₀ estimates with Global Data Assimilation System (GDAS) potential evapotranspiration (PET) showed RMSD within a range of 1.4–18.4% for most of the months, except for two. Further ET₀ analysis over normal and drought years showed that it could be used for comprehensive drought assessment with other existing indicators.     

Synthesis and Biological Characterization of (3R,4R)‐4‐(2‐(Benzhydryloxy)ethyl)‐1‐((R)‐2‐hydroxy‐2‐phenylethyl)‐piperidin‐3‐ol and Its Stereoisomers for Activity toward Monoamine Transporters

A novel series of optically active molecules based on a 4‐(2‐(benzhydryloxy)ethyl)‐1‐((R)‐2‐hydroxy‐2‐phenylethyl)‐piperidin‐3‐ol template were developed. Depending on stereochemistry, the compounds exhibit various degrees of affinity for three dopamine, serotonin, and norepinephrine transporters. These molecules have the potential for treating several neurological disorders such as drug abuse, depression, and attention deficit hyperactivity disorder.

     

Method for measuring thickness of dielectric films using microdielectric fringe-effect sensors

A method for noninvasive thickness measurements of dielectric films using fringe-effect (FE) sensors is developed and experimentally validated. The fringing electrical field, created by electrodes microfabricated at the film substrate, depends on the film thickness and dielectric permittivity of the film under test (FUT). The unknown film thickness is estimated by matching the theoretical prediction of thickness-dependent sensor admittance with the measured value. In the case of FE sensors with spatially periodic, interdigitated electrode (IDE) configuration, the admittance prediction is simplified, which allows for the real-time measurements of changing thickness. The developed method can be used to continuously measure the changing dielectric permittivity of the FUT material, which makes it possible to determine the thickness of films of changing dielectric properties, caused by chemical or other transformations. The application of the developed method is demonstrated experimentally by measuring the thickness of silicon nitride film deposited in several increments on the quartz substrate of the IDE sensor. In the expected range of sensor sensitivity, the results show an excellent agreement with the independent thickness measurements.     

Electrodeposition of amorphous silicon anode for lithium ion batteries

Amorphous silicon has been successfully electrodeposited on copper using a SiCl₄ based organic electrolyte under galvanostatic conditions. The electrodeposited silicon films were characterized for their composition, morphology and structural characteristics using glancing angle X-ray diffraction (GAXRD), scanning electron microscopy (SEM), and Raman spectroscopy. GAXRD and Raman analyses clearly confirm the amorphous state of the deposited silicon film. The deposited films were tested for possible application as anodes for Li-ion battery. The results indicate that this binder free amorphous silicon anode exhibits a reversible capacity of ∼1300 mAh g⁻¹ with a columbic efficiency of >99.5% up to 100 cycles. Impedance measurements at the end of each charge cycle show a non-variable charge transfer resistance which contributes to the excellent cyclability over 100 cycles observed for the films. This approach of developing thin amorphous silicon films directly on copper eliminates the use of binders and conducting additives, rendering the process simple, facile and easily amenable for large scale manufacturing.