Wavelet: a new trend in chemistry

Since 1989, wavelet transform (WT) has attracted much interest of chemists working on signal and image processing, and the WT-based techniques have been successfully applied to the chemical signal processing. This approach has been demonstrated as fast in computation with localization and having quick decay properties, in contrast to the popular methods existing, especially to the fast Fourier transform. More than 370 papers have been published up to the year 2002 which covered applications of WT in various fields of chemistry, including analytical chemistry, chemical physics, and quantum chemistry. In this paper, we report on applications of WT to data compression, data smoothing and denoising, baseline and background correction, resolution of multicomponent overlapping signals, regression and classification, and analytical images processing in analytical chemistry. Through this report we wish to induce greater interest of chemists in WT and to obtain greater benefits from using the WT-based techniques.     

High-performance BiCMOS 100 K-gate array

A BiCMOS gate array in 0.8-μm technology with CMOS intrinsic gate delays of 100 ps plus 60 ps/fan-out and BiCMOS intrinsic delays of 200 ps with a 17-ps/fan-out drive factor is discussed. A compact base cell (750 μm²/gate) has been designed with full bipolar drive capability for the efficient layout of both primitive gates and large-arrayed macros, such as register files and multipliers. A 106 K-gate array has been built on a 1.14-cm² chip with ECL I/O capability. The place and route in three levels of metal provide array utilization greater than 90%. The gate array was used to implement a 74 K-gate filter design with testability features such as JTAG and two-phase scan     

Chaotic motion under parametric excitation

The chaotic behaviour of a parametrically excited system is studied in some detail. An example of such a system is seen in the transverse vibration of a buckled column under axial excitation. The existence of homoclinic orbits for the parametrically excited system is predicted by Melnikov's method. Lyapunov exponents, Poincaré maps, power spectra and other characteristics of chaotic motions are analysed numerically to confirm the results. An experiment on a buckled column is also carried out to qualitatively verify the theoretical results.     

Domain morphology in polyurethanes

The domain morphology of a polyurethane has been visualized by dark field electron microscopy. Ageing of both as-cast and drawn films results in an increase in size and perfection of the soft segment domains over an extended period of time. Annealing taut drawn films above the melting point of the soft segment results in a complete rearrangement of the morphology. The dark field studies are supplemented by electron microscopic observations of replicas and stained samples and correlated with corresponding changes in physical properties.     

Rapid prototyping methodology for multiprocessor implementation of digital signal processing systems

A methodology for the hierarchical partitioning and mapping of digital signal processing (DSP) tasks to heterogeneous local cluster based network of very large scale integration (VLSI) processors is presented. The goal is to achieve rapid prototyping of VLSI DSP systems. The high level partitioning issues of DSP task graphs and the proposed metrics to guide the partitioning process are described in this paper. Partitioning tominimize power inefficiency in the DSP system is one important metric addressed by this work, since low power signal processing is paramount to new portable and high density multi-chip module (MCM) DSP systems. The application of theRatio Cut Partitioning approach to DSP graphs is explained. We illustrate our results with examples and show how the final partitions vary depending upon the target architecture to meet rapid prototyping requirements. We compare our approach with known techniques and show that it works much better for our target applications.     

"Ambient Temperature Isoelectronic Detectors: Status and Prospects

Potential use of high-Z semiconductor detectors operating in the charge collection mode as ?-ray spectrometers at ambient temperatures appears to be limited by charge collection problems. Improvements in present scintillators through improved linearity and higher fluorescent efficiency appear possible. T. C. Madden, et al., 1 suggested the use of isoelectronic scintillators as an improved scintillator material. We have studied the possibility of using one of these, Te doped CdS, as a ?-ray spectrometer.     

Crime data mining: a general framework and some examples

A major challenge facing all law-enforcement and intelligence-gathering organizations is accurately and efficiently analyzing the growing volumes of crime data. Detecting cybercrime can likewise be difficult because busy network traffic and frequent online transactions generate large amounts of data, only a small portion of which relates to illegal activities. Data mining is a powerful tool that enables criminal investigators who may lack extensive training as data analysts to explore large databases quickly and efficiently. We present a general framework for crime data mining that draws on experience gained with the Coplink project, which researchers at the University of Arizona have been conducting in collaboration with the Tucson and Phoenix police departments since 1997.     

Effect of lipid solubility on the development of chronic cross-tolerance between ethanol and different alcohols and barbiturates

Tolerance to ethanol and cross-tolerance to other alcohols (n-propanol, n-butanol, t-butanol, isobutanol, t-amyl alcohol, n-amyl alcohol, and benzyl alcohol) and barbiturates (pentobarbital, secobarbital, amobarbital, thiopental, barbital and phenobarbital) that differ in lipid:water partition coefficient was examined in rats after chronic pretreatment with ethanol. Tolerance and cross-tolerance were studied with three different measures (hypothermia, tilt-plane, and rotarod). Tolerance to ethanol resulted in significant cross-tolerance to alcohols with low lipid solubility (n-propanol and t-butanol), whereas no cross-tolerance was seen with alcohols of high lipid solubility (isobutanol, n-amyl alcohol, t-amyl alcohol and benzyl alcohol). Cross-tolerance to n-butanol (which has intermediate lipid solubility) appeared to be metabolic rather than functional. Tolerance to ethanol also resulted in significant cross-tolerance to barbital and phenobarbital, but not to pentobarbital, secobarbital, amobarbital or thiopental. These studies suggest that lipid solubility is an important factor in relation to specificity of cross-tolerance to alcohols and barbiturates.     

Long-term survival after gastrectomy for advanced bleeding or perforated gastric carcinoma

OBJECTIVE: To find out whether massive bleeding or free perforation of advanced gastric carcinoma affect long term survival after gastrectomy. DESIGN: Retrospective analysis of prospectively collected data. SETTING: Teaching hospital, Hong Kong. INTERVENTIONS: Gastrectomy. MAIN OUTCOME MEASURES: Long term survival. RESULTS: Data of 50 patients with gastric carcinoma that had penetrated the serosa (pT3) and who were operated on between 1985 and 1990 were analysed. A total of 17 patients with tumour free perforation and 10 with massive bleeding underwent emergency gastrectomy, and 23 patients with comparable uncomplicated tumours had elective gastrectomy. Twelve variables that could have influenced survival including malignant perforation, bleeding, or the absence of complications were analysed using the Cox's proportional hazards model. Survival was influenced only by proliferative cell nuclear antigen (PCNA) index and not by perforation, bleeding, or the uncomplicated nature of the tumour. CONCLUSIONS: These findings suggest that perforation or bleeding from advanced gastric carcinomas do not significantly affect long term survival after gastrectomy.