Laterally pumped GaAs/AlGaAs quantum wells as sources of broadband terahertz radiation

In this work we consider lateral current pumped GaAs/AlGaAs quantum wells as sources of incoherent terahertz radiation. The lateral field heats the electrons in a two-dimensional quantum layer and increases the population of higher subbands, hence also increasing the radiation power generated in spontaneous intersubband emission processes. Digitally graded quasi-parabolic and simple square quantum wells are considered, and the advantages of both types are discussed. Calculations at lattice temperatures of 77 K and 300 K, for electric fields up to 10 kV/cm, show that the optical output power of ~100−200 W/m2 may be achieved for the 7 THz source. The main peak of the spectrum, at 7 THz, of the quasi-parabolic quantum well exceeds the black body radiation at 300 K by approximately a factor of two and by two orders of magnitude at 77 K

MILITAAROBJEKTIDE VALVETEHNOLOOGIA ARENG

Artikkel analüüsib viimastel aastatel maailmas käivitunud infotehno loogilisi arenguhüppeid, mis on toonud olulisi muutusi valvesüsteemide alale. Militaarobjektide valvesüsteeme on käsitletud nii sensorseadmete, süsteemi arhitektuuri kui ka üha rohkem tehisintellekti kasutava andmetöötluse vaates. Käsit luse süstematiseerimiseks on esile toodud neli põhilist alamsüsteemi ning teema sidu miseks maailma arengusuundadega on analüüsitud kaheksa olulise infotehnoloogilise uurimisteema kasvukõveraid. Detailsemalt käsitletud sensorseadmed on järgmised: 1) valvekaamerad nähtava valguse, lähiinfrapuna ja soojuskiirguse diapasoonidele; 2) sensoritega varustatud targad piirdetarad; 3) süsteemid mehitamata õhusõidukite avastamiseks ja jälgi miseks. Kaamerate puhul on analüüsitud kujutise sensorite arengutendentse ja DORI (detekteerimine, jälgimine, eristamine, identifitseerimine) tuvastusstandardit. Artiklis käsitletakse olulisemaid termineid ning arengusuundi, pidades silmas materjali võimalikku kasutamist tehniliste erialade väljaõppes Kaitseväe Akadeemias ja mujal

Investigation of Silicon Carbide Diode Structures via Numerical Simulations Including Anisotropic Effects

The Poisson's and continuity equatians based SIC-DYNAMIT-lDT@DT simulators with anisotropic material analysis capabilities were developed. A comparison of experimental and simulated forward I/V curves for three 6H-Sic P+NNf diodes is presented and the related model parameter adjustment problems are discussed. The influence of the strong electron mobility anisotropy on carrier dislributions is investigated and the existence of a "mobility anisotropy induced anomalous charge accumulation effect " is demonstrated. 1

Modeling the trajectory tracking accuracy of an autonomous catamaran patrol vessel under different positional data disturbance conditions

A sharp increase in the importance of autonomous vehicles can be foreseen in future maritime transport. One important area of application of autonomous waterborne vehicles is the monitoring of the safety of sea routes and sea areas. In this case, an important subtask is following the desired coordinates and movement trajectories as accurately as possible, despite natural disturbances and malicious cyberattacks. In this work, we discuss the model-based ship navigation with increased disturbance resistance to assure the desired control of a catamaran robot ship in different conditions of natural disturbances and missing global positioning data due to possible cyber-attacks. The considered example autonomous surface vessel (ASV) is a catamaran ship of 2.5 m length, developed at Tallinn University of Technology. Different from the previous studies, in this work we have completed the hydromechanical ship model with wind force model in order to simulate the influence of nonlinear environment conditions to the accuracy of ship navigation. The main result, illustrated by detailed numerical calculations, is that the availability of an accurate mathematical model of ASV together with accurate data from local sensors (in particular ship direction and wind speed sensors) can compensate for the lack of a GPS signal under cyber-attack conditions. In addition, we demonstrate with a numerical simulation how data fusion methodology, supplementing the wind effect measurements with local ship sensor data, can achieve even better navigation accuracy.Peer Reviewe

Monitoring cattle behavior and pasture use with GPS and GIS

Precision agriculture is already being used commercially to improve variability management in row crop agriculture. In the same way, understanding how spatial and temporal variability of animal, forage, soil and landscape features affect grazing behavior and forage utilization provides potential to modify pasture management, improve efficiency of utilization, and maximize profits. Recent advances in global positioning system (GPS) technology have allowed the development of lightweight GPS collar receivers suitable for monitoring animal position at 5-min intervals. The GPS data can be imported into a geographic information system (GIS) to assess animal behavior characteristics and pasture utilization. This paper describes application and use of GPS technology on intensively managed beef cattle, and implications for livestock behavior and management research on pasture

Stay in Your Own Back Yard / music by Lyn Udal; words by Karl Kennett

Cover: description reads pickaninny ballad; Publisher: M. Witmark and Sons (New York)https://egrove.olemiss.edu/sharris_a/1057/thumbnail.jp

Monitoring cattle behavior and pasture use with GPS and GIS

Precision agriculture is already being used commercially to improve variability management in row crop agriculture. In the same way, understanding how spatial and temporal variability of animal, forage, soil and landscape features affect grazing behavior and forage utilization provides potential to modify pasture management, improve efficiency of utilization, and maximize profits. Recent advances in global positioning system (GPS) technology have allowed the development of lightweight GPS collar receivers suitable for monitoring animal position at 5-min intervals. The GPS data can be imported into a geographic information system (GIS) to assess animal behavior characteristics and pasture utilization. This paper describes application and use of GPS technology on intensively managed beef cattle, and implications for livestock behavior and management research on pasture

Improved C5D Electronic Realization of Conductivity Detector for Capillary Electrophoresis

The axial C4D (Capacitively Coupled Contactless Conductivity Detection) measurement electronics for capillary electrophoresis is considered and a new improved C5D compensated detection concept is proposed and tested. Using the idle compensation channel with inversed signal and immediate analogue summation of the active and idle channel currents yields effective suppression of the influence of the parasitic stray capacitance. Preliminary experiments have confirmed at least three-fold improvements of measurement resolution. Realisation of electronics allows flexible tuning of frequency from 0.2 MHz to 2 MHz. The relatively high voltage supply of 15 V for the AC measurement units together with 24- bit accurate analogue-to-digital converter yields additional improvement for the sensitivity

Motor function may differentiate attention deficit hyperactivity disorder from early onset bipolar disorder

<p>Abstract</p> <p>Background</p> <p>Differentiating between bipolar spectrum disorder (BD) and attention deficit hyperactivity disorder (ADHD) in childhood and adolescence is difficult because the clinical presentation is influenced by ongoing neural development, causing considerable symptom overlap. Motor problems and neurological soft signs have been associated with ADHD for decades. Little is known about motor skills in BD. Here we assess the diagnostic accuracy of neuromotor deviations in differentiating ADHD from BD in clinical practice. We also investigate if these deviations exist in concurrent ADHD and BD, thus indicating true comorbidity</p> <p>Methods</p> <p>64 patients 6-18 years (31 girls, 33 boys) fulfilling the diagnostic criteria of BD, ADHD combined subtype (ADHD-C) or comorbid BD and ADHD-C, were compared using an age-standardized neuromotor test; NUBU. Categorical variables were analyzed using cross table with two-tailed chi square test or Fisher's exact test when appropriate. Continuous variables were analyzed by Kruskal-Wallis test and, if significant, Mann-Whitney U test and ROC plots.</p> <p>Results</p> <p>The ADHD-C group and the comorbid ADHD-C and BD group both showed significantly more neurological soft signs (p less than 0.01) and lower mean static coordination percentile (p less than 0.01) than the BD group. The positive predictive value of NUBU in the diagnosis of ADHD-C with or without concurrent BD was 89% (80-95) for total soft signs and 87% (79-95) for static coordination below the 7.5 percentile.</p> <p>Conclusion</p> <p>An age-standardized neuromotor test battery may promote diagnostic accuracy in differentiating ADHD from BD in clinical practice, and help evaluating whether symptoms of ADHD in children who have BD reflect symptom overlap or real comorbidity. This may have important implications for everyday diagnostic work.</p

Seeing the Forest for the Trees : Gardening as cultural landscape conservation in Vancouver Island's Forests

This project argues that traditional modes of landscape conservation fail to highlight the complex social, political, ecological and economic dynamics that work to create cultural landscapes. On Vancouver Island, the ongoing tension between logging and conservation continues to reinforce the polarizing resource-wilderness dichotomy that has been so intrinsic to western perceptions of landscape. By proposing ‘gardening’ as the programmatic basis for site intervention, this project suggests an alternative cultural landscape narrative for Vancouver Island’s forests.Applied Science, Faculty ofArchitecture and Landscape Architecture (SALA), School ofUnreviewedGraduat