A similarity measure between patterns with nonindependent attributes

A generalized version of a set-theoretical measure for obtaining similarities between patterns with nonindependent attributes is presented. The dependence here is given by the pairwise correlation. Since the proposed measure needs no assumption of attribute independence, the resulting similarity values can reflect directly the relationships between the attributes.     

Transparency of LiTaO3-SiO2-Al2O3 glass-ceramics in relation to their microstructure

The glasses with various compositions in the LiTaO₃-SiO₂-Al₂O₃ system were heated from room temperature to temperatures ranging from 750° to 1050° C at a rate of 5° C min^–1. From the glasses in the LiTaO₃-SiO₂ system no transparent glass-ceramic was obtained even when their LiTaO₃/SiO₂ mole ratios were as high as 2.33. The diameter and number of the LiTaO₃ crystal grains precipitated in the glasses were 5–15 m and 10⁸–10¹⁰ grains cm^–3, respectively. On the contrary, transparent glass-ceramics were obtained from the glasses containing Al₂O₃; their compositions covered a fairly large area in the LiTaO₃-SiO₂ -Al₂O₃ system, which encompasses the compositions with the LiTaO₃/SiO₂+AlO_1.5 mole ratio as low as 0.25. The diameter and number of the LiTaO₃ crystal grains precipitated in the transparent glass-ceramics were as small as 10–20 nm and as many as 10¹⁶–10¹⁸ grains cm^–3, respectively. High nucleation rates of the LiTaO₃ crystals in the Al₂O₃-containing glasses were interpreted in terms of structural inflexibility induced in the glass-network by the addition of Al₂O₃ to the LiTaO₃-SiO₂ system.     

Electrochemical window of molten LiCl-KCl-CaCl2 and the Ag/Ag reference electrode

The electrochemical window of an LiCl-KCl-CaCl₂ eutectic melt (52.3:11.6:36.1 mol%) was determined by cyclic voltammetry and open-circuit potentiometry at 723-873 K. The reaction at the anodic limit was confirmed to be Cl₂ gas evolution. The reaction at the cathodic limit was found to be a liquid Ca-Li alloy formation on the basis of ICP analysis of the deposits. An Ag⁺/Ag reference electrode separated with a Pyrex membrane showed good stability for more than 1 week. The standard electrode potential of Ag⁺/Ag was determined in the temperature range of 723-823 K by measuring the potential of a silver electrode in different concentrations of Ag⁺ ions.     

Partitioning a Weighted Tree into Subtrees with?Weights in a Given Range

Assume that each vertex of a graph G is assigned a nonnegative integer weight and that l and u are given integers such that 0≤l≤u. One wishes to partition G into connected components by deleting edges from G so that the total weight of each component is at least l and at most u. Such a partition is called an (l,u)-partition. We deal with three problems to find an (l,u)-partition of a given graph: the minimum partition problem is to find an (l,u)-partition with the minimum number of components; the maximum partition problem is defined analogously; and the p-partition problem is to find an (l,u)-partition with a given number p of components. All these problems are NP-hard even for series-parallel graphs, but are solvable in linear time for paths. In this paper, we present the first polynomial-time algorithm to solve the three problems for arbitrary trees.     

Exploiting DLP Illumination Dithering for Reconstruction and Photography of High-Speed Scenes

In this work, we recover fast moving scenes by exploiting the high-speed illumination “dithering” of cheap and easily available digital light processing (DLP) projectors. We first show how to reverse-engineer the temporal dithering for off-the-shelf projectors, using a high-speed camera. DLP dithering can produce temporal patterns commonly used in active vision techniques. Since the dithering occurs at a very high frame-rate, such illumination-based methods can be “speed up” for fast scenes. We demonstrate this with three applications, each of which only requires a single slide to be displayed by the DLP projector. The quality of the result is determined by the camera frame-rate available to the user. Pairing a high-speed camera and a DLP projector, we demonstrate structured light reconstruction at 100 Hz. With the same camera and three or more DLP projectors, we show photometric stereo and demultiplexing applications at 300 Hz. Finally, with a real-time (60 Hz) or still camera, we show that DLP illumination acts as a very fast flash, allowing strobe photography of high-speed scenes. We discuss, in depth, some characteristics of the temporal dithering with a case study of a particular projector. Finally, we describe limitations, trade-offs and other issues relating to this work.     

System Identification of Base-Isolated Building using Seismic Response Data

Due to the complex nature of the excitation, and the inherent dynamics characteristics of restoring force of the base isolation systems, the response of base-isolated structures subject to strong earthquakes often experiences excursion into the inelastic range. Therefore, in designing base-isolated structures, the nonlinear hysteretic restoring force model of the base isolation system is frequently used to predict structural response and to evaluate structural safety. In this paper, the prediction error method system identification technique is used in conjunction with nonlinear state-space models for identification of a base-isolated structure. Using a variety of nonlinear restoring force models and bidirectional recorded seismic responses, several identification runs are conducted to evaluate the accuracy of the selected models. Several nonlinear restoring force models are utilized for the base-isolation system, including a multiple shear spring (MSS) model. Among all models used, results indicate that the trilinear hysteretic MSS model closely matches the actual hysteretic restoring force profile and time histories obtained directly from the observed data.     

GRAPES-3—A high-density air shower array for studies on the structure in the cosmic-ray energy spectrum near the knee

The change in the spectral index from about -2.7 to -3.1 at 3×10¹⁵ eV in the all-particle energy spectrum of primary cosmic rays is very significant for learning about the nature of cosmic sources of ultra-high energy particles and their acceleration and propagation in the galactic disk. Any observation of a fine structure in the spectrum would be important for improving our understanding of these physical processes. The GRAPES-3 air shower array has been designed to achieve higher precision in determination of various shower parameters to enable observation of any fine structure in the energy spectrum, if it exists. The details of the shower detectors, shower trigger and the data acquisition system are presented here along with estimates of trigger efficiencies from Monte Carlo simulations for primary photons (γ-rays) and several nuclei.     

AlGaN/GaN HEMTs With Thin InGaN Cap Layer for Normally Off Operation

AlGaN/GaN HEMTs with a thin InGaN cap layer have been proposed to implement the normally off HEMTs. The key idea is to employ the polarization-induced field in the InGaN cap layer, by which the conduction band is raised, which leads to the normally off operation. The fabricated HEMT with an In_0.2Ga_0.8N cap layer with a thickness of 5 nm showed normally off operation with a threshold voltage of 0.4 V and a maximum transconductance of 85 mS/mm for the device with a 1.9-mum-long gate. By etching off the In_0.2Ga_0.8N cap layer at the access region using gate electrode as an etching mask, the maximum transconductance has increased from 85 to 130 mS/mm due to a reduction of the parasitic source resistance.     

Covalent Functionalization of Carbon Nanohorns with Porphyrins: Nanohybrid Formation and Photoinduced Electron and Energy Transfer

The covalent attachment of carbon nanohorns (CNHs) to α‐5‐(2‐aminophenyl)‐α‐15‐(2‐nitrophenyl)‐10,20‐bis(2,4,6‐trimethyl‐phenyl)‐porphyrin (H₂P) via an amide bond is accomplished. The resulting CNH–H₂P nanohybrids form a stable inklike solution. High‐resolution transmission electron microscopy (HRTEM) images demonstrate that the original dahlia‐flowerlike superstructure of the CNHs is preserved in the CNH–H₂P nanohybrids. Steady‐state and time‐resolved fluorescence studies show efficient quenching of the excited singlet state of H₂P, suggesting that both electron and energy transfer occur from the singlet excited state of H₂P to CNHs, depending on the polarity of the solvent. In the case of electron transfer, photoexcitation of H₂P results in the reduction of the nanohorns and the simultaneous oxidation of the porphyrin unit. The formation of a charge‐separated state, CNH^?––H₂P^?+, has been corroborated with the help of an electron mediator, hexyl‐viologen dication (HV²⁺), in polar solvents. Moreover, the charge‐separated CNH^?––H₂P^?+ states have been identified by transient absorption spectroscopy.     

Charging characteristics and electric field distribution on alumina as affected by triple junctions in vacuum

This paper describes the dependence of the charging characteristics on the electric field distribution on the alumina (Al/sub 2/O/sub 3/) surface as affected by the triple junction in vacuum. For HV electrical insulation design of vacuum interrupter, surface flashover in vacuum is very important problem to be solved. Attention should be paid to the fact that the insulation characteristics on the dielectric surface are strongly influenced by field emission of electrons from the triple junction and the accumulated charges on the dielectric surface. In order to clarify the charging mechanism, we measured the charging characteristics for various types of triple junctions. In particular, we focused on the influence of the electric field distribution along the solid dielectrics and near the cathode triple junction (CTJ) on the charging characteristics. The results confirmed that the electric field distribution strongly affected the 2-dimensional (2D) distribution of the surface charge on the dielectric sample. Consequently, it was found that positive charging was generated on alumina, when the incident angle of the electric line of force on the alumina surface became >60/spl deg/.