Study of Al–Ti/Si bi-layer as the recording media for write-once HD-DVD optical disks

Optimum structure for HD-DVD optical disks containing Al–Ti/Si bi-layer recording system was identified by reflectivity simulation and dynamic test of disk samples. For the disk sample with optimized structure, the maximum partial response signal-to-noise ratio (PRSNR) of 19.1 dB, minimum simulated bit error rate (sbER) of 1.7 × 10^?7 and modulation >0.6 were achieved at the writing power (P_w) = 11.2 mW. Transmission electron microscopy (TEM) revealed that the polycrystalline granular clusters constitute the recording marks. Subsequent analyses evidenced that element mixing/alloy reactions occur in between Si and Al–Ti layers and the formation of Al_3.21Si_0.47 crystalline phase is responsible for the signal recording in the disk samples.     

Metal–Nonmetal Transition in Rubidium Tungsten Bronze RbxWOy

An oxygen concentration dependent metal–nonmetal (MN) transition was observed for Rb_0.23WO _y with 2.80 < y < 3.08. As 2.80 < y < 3.0, the room temperature resistivity (_RT) of the Rb_0.23WO _y is about 5 × 10^–4 cm. While in the case of y > 3.04, the _RT of the Rb_0.23WO _y exhibits a four orders of magnitude increase with a value of 5 cm. Correspondingly, the lattice constant along c-direction slightly shortens as oxygen concentration increases from 2.80 to 3.08. The observed results suggest that the hybridization between W 5d (t_2g) and O 2p orbitals might be responsible for the MN transition. In addition, similar measurements were performed for Rb _x WO_3.04 and Rb _x WO_2.85 with 0.19 < x < 0.27. No rubidium concentration dependent MN transition was observed, indicating the electronic structure of the host WO _y is not modified significantly by varying the soluble rubidium concentration.     

Telechelic elastomers

Telechelic elastomers, polymers with reactive terminal groups, can be prepared in emulsion and solution systems. Examples of characterization of the polymers and preparation of a mercapto telechelic copolymer in an emulsion system and of mercapto-, hydroxy-, and aziridinyl-telechelic elastomers in solution systems are given. The elastomers were cured in peroxide or sulfur-accelerator formulations. The telechelic polymers exhibited enhanced stress-strain and dynamic properties in comparision to those of the controls. In tread formulations, outstanding properties were obtained for the mercapto-and azieridinyl-telechelic butadiene-styrene copolymers.     

Sampling variability of the area under the ROC-curve and of d'e.

By computer simulation, random samples were drawn from underlying Gaussian, uniform, and negative exponential distributions which differed in terms of their mean and variance. The conditional probability of an observation of a given magnitude, or higher, was computed for each of 2 distributions. Resulting conditional probabilities for the 2 distributions trace out a receiver operating characteristic (ROC) curve. The area under the ROC-curve, which provides a distribution-free measure of performance, was calculated over a wide range of possible performances. It is shown that the sampling variability of the area measure is dependent upon its mean value and is relatively independent of the complex of conditions which lead to the given mean value. A similar conclusion is reached for the sampling variability of the intersection of the ROC-curve with the negative diagonal. This measure leads to an estimate of the sampling variability of the measure d'e, an index of O performance, often employed in the signal detectability approach to performance measurement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Macromodelling — an approach for analysing large-scale circuits

Macromodelling is a new area of circuit theory which has gained importance with the advent of large scale integration for semiconductor chips. These integrated circuits require an analysis capability which far exceeds presently available computer-aided network analysis programs. This paper gives an overview of work which pertains to the area of macromodelling. Also, recent progress in macroanalysis is discussed, such as the latent approach, which is a method which takes advantage of the natural small activity in large systems.     

InGaAsSb/InP Double Heterojunction Bipolar Transistors Grown by Solid-Source Molecular Beam Epitaxy

This letter investigates the dc characteristics of a double heterojunction bipolar transistor (DHBT) with a compressively strained InGaAsSb base, which is grown by solid-source molecular beam epitaxy. The novel InP/InGaAsSb HBT has a lower base/emitter (B/E) junction turn-on voltage, a lower offset voltage, and a junction ideality factor closer to unity than the conventional InP/InGaAs composite collector DHBT. These characteristics are attributed to the transistor's type-I B/E junction and type-II base/collector junction, which facilitates carrier transport for low power, high current density, and high-speed operation. Heterojunction bipolar transistors (HBTs), InP/InGaAsSb, molecular beam epitaxy (MBE).     

A k-Round Elimination Contention Scheme for WLANs

The contention resolution scheme is a key component in carrier-sense-based wireless MAC protocols. It has a major impact on MAC'S performance metrics such as throughput, delay, and jitter. The IEEE 802.11 DCF adopts a simple contention resolution scheme, namely, the binary exponential backoff (BEB) scheme. The BEB scheme achieves a reasonable performance for transmitting best-effort packets in small-sized wireless networks. However, as the network size increases, it suffers from inefficiency because of the medium contention, which leads to reduced performance. The main reason is that the BEB mechanism incurs an ever- increasing collision rate as the number of contending nodes increases. We devise a novel contention resolution scheme, a k-round elimination contention (k-EC) scheme. The k-EC scheme exhibits high efficiency and robustness during the collision resolution. More importantly, it is insensitive to the number of contending nodes. This feature makes it feasible for use in networks of different sizes. Simulation results show that the k-EC scheme offers a powerful remedy to medium contention resolution. It significantly outperforms the IEEE 802.11 DCF scheme in all the MAC'S performance metrics and also exhibits better fairness.     

Round‐robin measurement intercomparison of c‐Si PV modules among Asian testing laboratories

Because of recent advances in the production and installation of photovoltaic (PV) systems, the international conformity of PV module performance measurement has become increasingly important. The increase in PV production sites is particularly significant in the Asian region. The present paper summarizes and discusses the results of a round‐robin intercomparison of crystalline silicon modules among national laboratories and certified testing laboratories in the Asian region conducted from 2009 to 2011. Most of the values of P_max measured at the different laboratories were within a ±2% range, although some P_max results showed differences of up to about 3%. This result is comparable to that obtained in the recent intercomparison among international laboratories. Possible sources of difference in the measured values of I_sc, V_oc, FF, and P_max are discussed, for further improvement of international conformity in PV measurement technologies. Copyright © 2012 John Wiley & Sons, Ltd.     

Patterns of marital change during the early childhood years: Parent personality, coparenting, and division-of-labor correlates.

Cluster analysis was applied to the marital reports of 99 husbands and wives (from 104 families) obtained when their firstborn sons were 10, 27, 36, and 60 months of age to identify distinct patterns of change in marital functioning. Husband-love and wife-conflict scores revealed 3 distinct change patterns—stays good, bad to worse, and good gets worse—which afforded the opportunity to address 2 distinct questions, the 1st dealing with the correlates of consistently good and poor functioning marriages and the 2nd with what distinguishes marriages that initially functioned similarly (and well) but proceeded to develop in distinctively different ways. Results show, consistent with related findings from a study of newlyweds (B. Karney & T. Bradbury, 1997), that the answer to the 1st question is found in enduring personality traits of spouses, whereas the answer to the 2nd is found in observed marital dynamics (reflecting coparenting processes). (PsycINFO Database Record (c) 2010 APA, all rights reserved)