Subquadratic Algorithms for 3SUM

We obtain subquadratic algorithms for 3SUM on integers and rationals in several models. On a standard word RAM with w-bit words, we obtain a running time of . In the circuit RAM with one nonstandard AC ⁰ operation, we obtain . In external memory, we achieve O(n ²/(MB)), even under the standard assumption of data indivisibility. Cache-obliviously, we obtain a running time of . In all cases, our speedup is almost quadratic in the “parallelism” the model can afford, which may be the best possible. Our algorithms are Las Vegas randomized; time bounds hold in expectation, and in most cases, with high probability.     

A comparative study on some navigation schemes of a real robot tackling moving obstacles

A comparative study of various robot motion planning schemes has been made in the present study. Two soft computing (SC)-based approaches, namely genetic-fuzzy and genetic-neural systems and a conventional potential field method (PFM) have been developed for this purpose. Training to the SC-based approaches is given off-line and the performance of the optimal motion planner has been tested on a real robot. Results of the SC-based motion planners have been compared between themselves and with those of the conventional PFM. Both the SC-based approaches are found to perform better than the PFM in terms of traveling time taken by the robot. Moreover, the performance of fuzzy logic-based motion planner is seen to be comparable with that of neural network-based motion planner. Comparisons among all these three motion planning schemes have been made in terms of robustness, adaptability, goal reaching capability and repeatability. Both the SC-based approaches are found to be more adaptive and robust compared to the PFM. It may be due to the fact that there is no in-built learning module in the PFM and consequently, it is unable to plan the velocity of the robot properly.     

Optimally Adaptive Integration of Univariate Lipschitz Functions

We consider the problem of approximately integrating a Lipschitz function f (with a known Lipschitz constant) over an interval. The goal is to achieve an additive error of at most ε using as few samples of f as possible. We use the adaptive framework: on all problem instances an adaptive algorithm should perform almost as well as the best possible algorithm tuned for the particular problem instance. We distinguish between and , the performances of the best possible deterministic and randomized algorithms, respectively. We give a deterministic algorithm that uses samples and show that an asymptotically better algorithm is impossible. However, any deterministic algorithm requires samples on some problem instance. By combining a deterministic adaptive algorithm and Monte Carlo sampling with variance reduction, we give an algorithm that uses at most samples. We also show that any algorithm requires samples in expectation on some problem instance (f,ε), which proves that our algorithm is optimal.     

Anisotropy of some physical parameters in As-prepared As2S3 bulk glass

When cooling a melt the cooling rate in different layers varies due to differences in heat transfer. These changes in cooling rate were determined experimentally for the As₂S₃ melt in a quartz ampoule with diameter of 17 mm. The cooling rate at air quenching varies from 1.36 K/s in the bulk middle to 2.11 K/s in the border layers, and from 3.54 to 38.80 K/s for water quenching, respectively. Further, the corresponding changes in the density, microhardness, glass-transition temperature and electrical conductivity in dependence on the choice of the measured sample from various parts of the bulk were found. The anomalous behaviour of these parameters in dependence on the cooling rate corresponds to the polymeric structure of the glass.     

Linear Combination of Atomic Orbitals Approximation in Nanocrystalline Yittria-Stabilized Zirconia Synthesized by Citrate–Nitrate Gel Combustion Process

Nanocrystalline yittria-stabilized zirconia (YSZ) compounds with yittria concentration varying between 8 and 12 mol% have been synthesized by gel combustion method followed by heat treatment at 550°C. The YSZs are found to posses stable face centered cubic structure at room temperature by X-ray diffractometry. The lattice parameter ' a ' showed an increasing trend with increasing concentration of yittria. The crystallite size estimated by Scherrer method was in the range of 7–10 nm. Band gap studies showed an increasing trend with increasing yittria concentration and are found to be consistent with respective lattice parameters following the tight binding approximation or linear combination of atomic orbitals approximation.     

The Water-Soluble Peripheral Substituted Phthalocyanines as Corrosion Inhibitors for Copper in 0.1 N HCl: Gravimetric,Electrochemical, SEM-EDS,and Quantum Chemical Calculations

Protection of Metals and Physical Chemistry of Surfaces - Corrosion inhibition effects of water-soluble peripheral substituted cobalt, copper and zinc metallophthalocyanines (CoPc (1), CuPc (2) and...     

State estimation for real-time monitoring of distribution systems

Utilities currently use historical customer load data to forecast the loads in their distribution feeders for real-time feeder analysis and control. In this paper a three-phase state estimation method is developed to increase the accuracy of this load data. The method is based on the weighted least square approach and uses a three-phase node voltage formulation. The method can handle power, voltage, and current measurements. Test results indicate that state estimation can improve the forecasted load data by using real-time measurements. The effectiveness of branch current measurements were also tested     

ESMO 2003

This paper illustrates the development of an interface for the simulator EMTDC/PSCAD for integrating an agent-based distributed application into the simulation. The custom device modules the EMTDC supports have been used to provide a channel for the agents to communicate (send and receive data) with the simulator. The main advantage of this interface is that the agents now can be developed independently, as separate JAVA applications. The application used to illustrate the features of the interface is a pilot protection scheme over a line.