602 research outputs found
Classifying Corruption
Time delays reduces the performance of any controlled system. If neglected in the design phase, the system may even become unstable when using the designed controller. Several power control strategies have been proposed in order to improve the capacity of cellular radio systems, but time delays are usually neglected. Here, it is shown that the problems can be handled by considering the time delays in the design phase in order to choose the appropriate parameter values. Most popular algorithms can be seen as special cases of an integrating controller. This structure is extended first to a proportional integrating (PI)-controller and then further on to a general linear controller of higher orders. Corresponding design procedures are outlined based on techniques, such as pole placement, from the field of automatic control. The PI-controller is a very appealing choice of structure, with better performance compared to an I-controller and less complex than a higher order controller. The benefits are further illuminated by network simulations
Upholding the Dignity and Best Interest of Children: International Law and the Corporal Punishment of Children
When the systems evolved from analog to digital, the performance was improved by the use of power control on the one hand and different modulations and coding schemes on the other. Condensing the available information we are able to propose a new concept of power control. The concept is applicable to real systems, since it uses the available measurements for estimating parameters necessary for the power control. It also supports the use of an adequate quality measure together with a quality specification supplied by the operator. We will use frequency hopping GSM as an example and the resulting control algorithm is ready for implementation in the software in the base stations where the output powers are computed. No modifications are needed in the GSM standard, the mobile terminals, the radio interfaces or in the base station transmitters. Finally we provide simulation results confirming the benefits of using the new concept for power control
Construction Management and Design-Build/Fast Track Construction From the Perspective of a Generla Contractor
In the accompanying paper a method for blind (i.e., no calibration needed) estimation and compensation of the time errors in a time interleaved ADC system was presented. In this paper we evaluate this method. The Cramer-Rao bound is calculated, both for additive noise and random clock jitter. Monte-Carlo simulations have also been done to compare to the CRB. Finally, the estimation method is validated on measurements from areal time interleaved ADC system with 16 ADCs
Improved content mastery and written communication through a lab-report assignment with peer review: an example from a quantum engineering course
The promotion of high-quality written communication in the disciplines is an important learning outcome in higher education. Given the time invested by students and teachers alike, it is crucial that writing assignments also promote engagement and content learning. But is it worth the time for university teachers to invest in such \u27writing-to-learn\u27 activityes? We find that it can be, and present an improved design for an experimental lab-report writing assignment in an English medium instruction environment, where English is an additional language. Our context is assignment development for formative assessment in master\u27s-level physics, but the method is broadly applicable within the science-technology-engineering-math disciplines. Our first experience with the assignment resulted in substandard lab reports, suggesting insufficient subject understanding and prompting this assignment design. We therefore focused on communicating the alignment of aims, learning objectives, instruction, assessment criteria, and feedback design, and developed simplified rubrics facilitating assessment fairness and efficiency. The revised assignment enhanced the learning of the subject matter and the writing quality over the four years of the study, indicated by clearly improved reports and relevant peer feedback comments. The learning activity also had an observable but less distinct effect on the students\u27 exam performance
Quantum phase transitions in disordered dimerized quantum spin models and the Harris criterion
We use quantum Monte Carlo simulations to study effects of disorder on the
quantum phase transition occurring versus the ratio g=J/J' in square-lattice
dimerized S=1/2 Heisenberg antiferromagnets with intra- and inter-dimer
couplings J and J'. The dimers are either randomly distributed (as in the
classical dimer model), or come in parallel pairs with horizontal or vertical
orientation. In both cases the transition violates the Harris criterion,
according to which the correlation-length exponent should satisfy nu >= 1. We
do not detect any deviations from the three-dimensional O(3) universality class
obtaining in the absence of disorder (where nu = 0.71). We discuss special
circumstances which allow nu<1 for the type of disorder considered here.Comment: 4+ pages, 3 figure
Student and supervisor understanding of generic criteria for specific projects – A pilot study in an engineering education context
This paper offers an account of a pilot investigation into students’ and supervisors’ understanding and interpretation of university-wide guidelines and criteria for theses in engineering education. The university-wide criteria present both a means and a challenge for enhancing theses quality. To the extent that the means lies in indicating the expected standard, the challenge lies in the difficulty to interpret criteria relative specific student projects in order to decide what the criteria imply for specific engineering disciplines and projects. Consequently, there is a risk that despite articulating guidelines and criteria, the quality of theses does not improve since the discipline’s standards are insufficiently articulated by supervisors and poorly internalised by students. We suggest that revised supervision processes promoting student ownership and their informed engagement in criterion-based self- and peer-assessment might offer ways of promoting disciplinary discursive expertise for internalising standards by addressing the difficulty of understanding assessment criteria
The significance of the stubble height for the mechanical spillage during forage harvesting
Vall odlas vanligtvis antingen i renbestånd eller i blandbestånd med fleråriga baljväxter och gräsarter
vilka nyttjas till slåtter eller bete. Vid skörd av vall till foder för nötkreatur är den näringsmässiga
sammansättningen av stor vikt. Ett högre näringsvärde kan uppnås genom en tidigarelagd skörd, ett
ökat antal skördetillfällen samt en väl anpassad gödslingsstrategi. Under senare år har försök
genomförts för att undersöka om en anpassning av stubbhöjden och fraktionering av grödan kan
vara ett alternativ för att uppnå önskad näringssammansättning vid skörd med lovande resultat. Det
är dessa undersökningar (Eriksson 2020) som har gett oss frågeställningen om en anpassning i
stubbhöjd har någon påverkan på mängden mekaniska förluster. De mekaniska förluster som uppstår
beror på grödans behandling med olika typer av maskiner vid slåtter, vändning, strängläggning och
lastning. Syftet med studien var att studera stubbhöjdens påverkan på det mekaniska spillet vid skörd
av vall samt att undersöka möjligheterna för att variera stubbhöjden på de maskiner som finns på
marknaden. I litteraturstudien presenteras en genomgång om vallodling och dess förluster,
stubbhöjdens betydelse, skördeteknik vid vallskörd samt vilka inställningsmöjligheter det finns på
vallmaskiner. Ett fältförsök har genomförts för att studera skillnaderna i totalskörd och mängden
mekaniskt spill vid fyra olika stubbhöjder. Fältförsöket genomfördes den 31 maj till den 1 juni 2022
i Hulterstad på Öland på en äldre vall (år 5). Försöket var ett helt randomiserat blockförsök med fyra
block och fyra led i varje block, de stubbhöjder som mättes var 7, 12, 17 samt 22 cm.
Slutsatsen av denna studie är:
Vid högre stubbhöjd minskade totalskörden från 5 700 kg torrsubstans per hektar vid 7 cm
stubbhöjd till 3 400 kg torrsubstans per hektar vid 22 cm stubbhöjd.
Mekaniskt spill vid låg stubbhöjd (7 cm) visade sig vara högst med 107 kg ts per hektar.
För stubbhöjderna 12, 17 och 22 cm var spillet mellan 60 och 70 kg ts per hektar. Enligt
Tukey´s metod är det en statistisk säkerställd skillnad mellan 7 cm och övriga stubbhöjder.
Burna slåttermaskiner kan hantera stubbhöjder från 5 till 12 cm. Vid högre stubbhöjder
krävs det att maskinen utrustas med justerbara släpskor. Med bogserade slåttermaskiner
kan en högre stubbhöjd uppnås med hjälp av lyftkolvarna.Grassland for fodder production is usually grown either with one species or in a mixture with
perennial legumes and grass species, the crop is used for mowing or grazing. When harvesting forage
for cattle the nutritional content of energy and protein is important. A higher nutritional value can
be achieved through an earlier harvest, an increased number of harvest occasions and a well-adapted
fertilization strategy. In recent years, trials have been carried out to investigate whether an adaptation
of the stubble height and fractionation of the crop can be an alternative to achieve the desired nutrient
composition at harvest with promising results. It is these studies (Eriksson 2020) that have given us
the question of whether an adaptation in stubble height has any effect on the amount of mechanical
losses. The mechanical losses that occur are due to the treatment of the crop with different types of
machines during mowing, tedding, swathing and loading. The purpose of the study was to study the
impact of the stubble height on the mechanical losses when harvesting ley and to investigate the
possibilities for varying the stubble height on the machines available on the market. The literature
study is an overview about ley cultivation and its losses, the importance of stubble height, harvesting
techniques for ley harvesting and the adjusting posibilities available on machines for ley production.
A field trial has been carried out to study the differences in total yield and the amount of mechanical
spillage at four different stubble heights. The field trial was implemented from 31 May to 1 June
2022 in Hulterstad at Öland on an older leyland (year 5). The experiment was a randomized complete
block, split-plot design experiment with four blocks and four plots in each block, the stubble heights
that were measured were 7, 12, 17 and 22 cm.
The conclusion of this study is:
At a higher stubble height the total yield decreased from 5 700 kg drymatter per hectare at
7 cm stubble height to 3 400 kg drymatter per hectare at 22 cm stubble height.
Mechanical losses at low stubble height (7 cm) was found to be the highest with 107 kg
drymatter per hectare. For the stubble heights of 12, 17 and 22 cm, the loss was between
60 and 70 kg drymatter per hectare. There is a statistically significant difference between
7 cm and the other stubble heights, according to Tukey's method.
Mounted mowers can handle stubble heights from 5 to 12 cm. For higher stubble heights,
the machine must be equipped with adjustable skidshoes. With trailed mowers a higher
stubble height can be achieved using the lifting pistons
Этиопатогенез и иммунологические изменения у новорожденных и детей раннего возраста, больных пневмонией
НОВОРОЖДЕННЫЙ, БОЛЕЗНИПНЕВМОНИЯДЕТЕЙ ОХРАНЫ ЗДОРОВЬЯ СЛУЖБ
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