A top-down quadtree traversal algorithm

Many standard image processing operations can be implemented using quadtrees as a simple tree traversal where, at each terminal node, a computation is performed involving some of that node's neighbors. Most of this work has involved the use of bottom-up neighbor-finding techniques which search for a nearest common ancestor. Recently, top-down techniques have been proposed which make use of a neighbor vector as the tree is traversed. A simplified version of the top-down method for a quadtree in the context of a general-purpose tree traversal algorithm is presented. It differs, in part, from prior work in its ability to compute diagonally adjacent neighbors rather than just horizontally and vertically adjacent neighbors. It builds a neighbor vector for each node using a minimal amount of information. Analysis of the algorithm shows that its execution time is directly proportional to the number of nodes in the tree. However, it does require some extra storage. Use of the algorithm leads to lower execution time bounds for some common quadtree image processing operations such as connected component labeling.     

Trends in alcohol-related mortality among New Mexico's American Indians, Hispanics, and non-Hispanic whites

Reduction of alcohol-related mortality is a national goal for health promotion and disease prevention. We conducted this analysis to determine whether trends in New Mexico's Hispanics, non-Hispanic Whites, and American Indians were consistent with national trends in alcohol-related mortality, and whether differences in drinking patterns could account for racial and ethnic differences in rates. Age-adjusted, race-specific, and ethnic-specific alcohol-related mortality rates and 95% confidence intervals were calculated for 5-year periods for 1958-1991 using New Mexico vital statistics data. We estimated the prevalence of acute and chronic at-risk drinking behaviors and abstinence from data collected by the Behavioral Risk Factor Surveillance System (BRFSS) for the period 1986-1992. We found that alcohol-related mortality rates varied substantially by race, ethnicity, sex, age, and calendar period. American Indians had the highest rates for both sexes. Rates increased sharply from the period 1958-1962 until the late 1970s and the early 1980s, and then began to decrease rapidly. However, during the most recent decade, the rates have followed contrasting trends in the three ethnic and racial groups. Although rates have continued to decline among non-Hispanic Whites, rates for Hispanics and American Indians have not declined, and still remain substantially higher than rates during the 1958-1962 period. Differences in at-risk drinking behaviors reported to the BRFSS do not explain the contrast in race-specific and ethnic-specific mortality rates. Although progress has been made in reducing national per capita alcohol consumption and alcohol-related mortality, certain high-risk racial and ethnic groups may not be sharing in the progress.     

New design of 3.2–4.8 GHz generator for multi-bands architecture of UWB communication

In this paper a new design of Ultra-Wide Band (UWB) generator is presented. This circuit is the most important block in multi-bands transmitter architecture of UWB communication system. The proposed UWB generator is composed of multi-bands voltage controlled oscillator (VCO), mixer and rectangular pulse generator which consist of ring oscillator, time delay and AND gate function. The UWB generator is based on multiplying the rectangular pulse envelope to a continuous sinusoidal wave in order to generate the UWB signal. This UWB generator circuit produces an output signal which is characterized by the bandwidth of 1600 MHz divided into three sub-bands of 528 MHz, centered at frequencies of 3.432, 3.96, 4.488 GHz and the limited Power Spectral Density (PSD) is −41.44 dBm/MHz. The maximum amplitude of UWB signal is 214 mV, the pulse is during of 3 ns and the pulse repetition period (PRP) is 32 ns. The power consumption is approximately equal to 26 mW at a voltage supply of 2.5 V. This topology is designed in CMOS 0.35 μm AMS process technology.     

Carbonaceous Materials-12: a Novel Highly Sensitive Graphene Oxide-Based Carbon Electrode: Preparation,Characterization, and Heavy Metal Analysis in Food Samples

Graphene oxide (GO) was covalently attached to glassy carbon (GC) electrode (GC–O–GO) for fabricating nanosensors to determine trace Pb²⁺ and Cd²⁺ using differential pulse anodic stripping voltammetry (DPASV). Surface characterization of the nanofilm-covered electrode was performed via electrochemical cyclic voltammetry (CV), transmission electron microscopy (TEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) techniques. Surface pKa of the GO covalent attached GC (GC–O–GO) was calculated via CV. Under optimal conditions, a linear response was found for Pb²⁺ and Cd²⁺ in the range from 1?×?10^?8 to 1?×?10^?12 M. The limit of detections (LODs) of Pb²⁺ and Cd²⁺ were 0.25 pM and 0.28 pM, respectively. The method shows good reproducibility, and stability was successfully applied to measure Pb²⁺ and Cd²⁺ levels in rice, soya, milk, and tap water samples, with good agreement with those obtained by the standard inductively coupled plasma optical emission spectrometry (ICP-OES) method. The method was evaluated by application with the simultaneous determination of the ions in food samples (n?=?6) using the standard addition method. The recoveries of the Pb²⁺ and Cd²⁺ were up to 98 %.     

Experience with software conversion

Experience with a program to convert from LISP 1.6 to INTERLISP is described. The conversion program was designed with two goals in mind. First, it had to be capable of being executed in either of the languages's environments and it had to yield identical results. Second, the speed of the converted program was to be approximately the same as the original program. This meant that the conversion process must be completed prior to execution of the converted program. The various constraints and considerations imposed by these goals are examined. In addition, aside from problems in finding INTERLISP analogs for various LISP 1.6 constructs, careful consideration must also be paid to input/output functions, escape characters, global variables, representation of numbers and different string implementations.