Architecture of a network-in-the-Loop environment for characterizing AC power system behavior

This paper describes the method by which a large hardware-in-the-loop environment has been realized for three-phase ac power systems. The environment allows an entire laboratory power-network topology (generators, loads, controls, protection devices, and switches) to be placed in the loop of a large power-network simulation. The system is realized by using a realtime power-network simulator, which interacts with the hardware via the indirect control of a large synchronous generator and by measuring currents flowing from its terminals. These measured currents are injected into the simulation via current sources to close the loop. This paper describes the system architecture and, most importantly, the calibration methodologies which have been developed to overcome measurement and loop latencies. In particular, a new "phase advance" calibration removes the requirement to add unwanted components into the simulated network to compensate for loop delay. The results of early commissioning experiments are demonstrated. The present system performance limits under transient conditions (approximately 0.25 Hz/s and 30 V/s to contain peak phase-and voltage-tracking errors within 5. and 1%) are defined mainly by the controllability of the synchronous generator

On the Bergman-Milton bounds for the homogenization of dielectric composite materials

The Bergman-Milton bounds provide limits on the effective permittivity of a composite material comprising two isotropic dielectric materials. These provide tight bounds for composites arising from many conventional materials. We reconsider the Bergman-Milton bounds in light of the recent emergence of metamaterials, in which unconventional parameter ranges for relative permittivities are encountered. Specifically, it is demonstrated that: (a) for nondissipative materials the bounds may be unlimited if the constituent materials have relative permittivities of opposite signs; (b) for weakly dissipative materials characterized by relative permittivities with real parts of opposite signs, the bounds may be exceedingly large

A 50 year old with a rapid neuropsychiatric deterioration and choreaform movements

A 50-year-old man presented acutely to the hospital with behavioural disturbance, choreiform movements and profound nihilistic delusions. He reported recent drug and alcohol abuse, and also apparent involvement in several recent criminal activities, for which he felt he should be punished. He arrived alone at the hospital after a concerned neighbour had called an ambulance. His initial level of agitation prevented formal cognitive testing. However, he was alert, verbally responsive and could obey commands. He was afebrile with normal observations and normal plasma glucose. Although his examination was challenging, the only abnormal neurological findings were bilateral choreiform upper limb movements

Economic Rent, inequality and public revenue - The Singapore Model

Private accumulation of economic rent from rising land values is increasingly identified as a key cause of rising inequality in advanced economies. Does the public collection of economic rent ensure greater equity? Singapore has been identified and praised for collecting a significant proportion of this rent, having achieved a high level of public ownership of land since independence in 1965. Anne Haila described this system, and Singapore, as a Property State (Haila, 2016). The system aligns with what Gavin Kerr calls Geo-classical liberalism (Kerr, 2017), where strong conditionality applies to land ownership, weak conditionality to wealth creation. Haila’s concept of the property state is used as a framework to research the socio-economic outcomes in Singapore. This thesis will fill a research gap, to provide a detailed analysis of how the system operates, why it was implemented, and reflect on its shortcomings. The public housing programme is considered a success, however, loopholes for significant private accumulation of economic rent by a professional elite remain, which through inheritance will be perpetuated, thus challenging Lee’s vision of the state’s foundation on principles of equity and reward for work. Through both quantitative and qualitative analysis of policy and institutional arrangements, I identify a partial implementation of the Geo-classical idea in Singapore, together with its dependence on foreign workers, and the constraints on political expression as potential weaknesses for the survival of an apparently stable polity. An extended Property State framework with a clearer application of Geo-classical principles is suggested as a means to resolve some of these inequities, for the future of Singapore. My contribution will be to illustrate how the Geo-classical theory might be applied fully in Singapore as a more complete model for other jurisdictions

Detection of West Nile virus activity in male and female mosquitoes, and evaluation of host-utilization patterns of mosquitoes, in East Baton Rouge Parish, Louisiana

ABSTRACT Host utilization patterns of female mosquitoes, and WNV infection rates in male and female mosquitoes, were examined in East Baton Rouge Parish to identify potential vectors of West Nile virus (WNV). A total of 244,374 female mosquitoes were collected between November 2002 and October 2004 and tested by viral isolation. Additionally, 131,896 female mosquitoes were tested by VecTest in 2003, and 167,175 female mosquitoes were tested by RT-PCR in 2004. West Nile virus was isolated from 17 of 36 mosquito species assayed by virus isolation, WNV antigens were detected in 9 of 27 species tested by VecTest, and WNV RNA was detected in 14 of 28 mosquito species tested by RT-PCR. The species with the greatest number of WNV positive pools by all 3 testing methods was Culex quinquefasciatus. The Terminal Restriction Fragment Length Polymorphism assay and direct sequencing were used to determine the host bloodmeal identity in 37 bloodfed Cx. coronator, 67 bloodfed Cx. salinarius, 114 bloodfed Cx. nigripalpus, and 686 bloodfed Cx. quinquefasciatus. The proportions of bloodmeals containing mammalian DNA were 94.6% for Cx. coronator, 82.1% for Cx. salinarius, 66.1% for Cx. nigripalpus, and 40.1% for Cx. quinquefasciatus. The White-tailed Deer was the most common host of Cx. coronator and Cx. salinarius. The most common mammalian host of Cx. nigripalpus and Cx. quinquefasciatus was the Northern Raccoon. Human DNA was detected in 7% of the bloodmeals of Cx. quinquefasciatus and 2.7% of the bloodmeals of Cx. nigripalpus. The Northern Cardinal was the most frequent avian host of Cx. quinquefasciatus and Cx. nigripalpus. There was no seasonal change in the monthly proportion of females of Cx. nigripalpus and Cx. quinquefasciatus feeding on mammals from May through October, in either 2003 or 2004. A total of 45 pools containing 171 males of 12 species were assayed for the presence of WNV by virus isolation, and 148 pools containing 7230 males of 15 mosquito species were tested by RT-PCR. Virus was isolated from single pools of male Cx. salinarius and Oc. triseriatus. Single pools containing male Cx. restuans, Ps. howardii, Oc. triseriatus and An. crucians were positive for WNV RNA

Obrada površinskog sloja zrnene robe s pomoću dijatomejske zemlje radi suzbijanja kukaca

This paper describes an alternative method to synthetic insecticides used for protection of stored agricultural products the purpose of which is to minimise the everyday human exposure to those chemicals. The method uses diatomaceous earth which is practically non-toxic to humans and fully acceptable for the environment. Fifty and 100-cmdeep layers of Hard Red Spring wheat Triticum aestivum (L.) in metal containers (cylinders), 30 cm in diameter and 150 cm in height were treated with 0.5 and 0.75 g of diatomaceous earth Protect-It® per kg of wheat. The treatment reduced the population of Sitophilus oryzae (L.), Tribolium castaneum (Herbst) and Rhyzopertha dominica (Fabricius) by 98 to 100% with respect to controls. The conclusion is that a 100-cm-surface layer treated with 0.5 g/kg of Protect-It® is sufficient to control these insects, and that no more than 20% of the total grain mass should be treated to minimise bulk density reduction. A field test using a similar design is essential to confirm the laboratory findings.Koncentracije dijatomejske zemlje potrebne za uspješno suzbijanje kukaca štetnih za uskladišteno žito imaju neželjen, negativan utjecaj na određena svojstva žita, primjerice na hektolitarsku masu i sipkavost, vrlo važne čimbenike koji određuju kakvoću žita. U namjeri da se negativni utjecaj dijatomejske zemlje na žitnu masu smanji, predlaže se obrada samo dijelova žitne mase (obrada slojeva) umjesto obrade cjelokupne mase žita. Pedesetcentimetarski i stocentimetarski površinski slojevi pšenice Triticum aestivum (L.) (Hard Red Spring) u metalnim posudama promjera 30 cm i visokim 150 cm, obrađeni s 0,5 i 0,75 grama Protect-It® po kilogramu pšenice nisu bili dostatni da potpuno spriječe prodor Sitophilus oryzae (L.) i Tribolium castaneum (Herbst) u neobrađeni sloj ispod obrađenog sloja pšenice. Međutim, u usporedbi s neobrađenom masom pšenice (kontrolnim ponavljanjima) populacija obiju vrsta bila je smanjena za više od 99%. Isto tako je u pšenici obrađenoj s Protect-It®, populacija Rhyzopertha dominica (Fabricius) bila smanjena za više od 98%, a istodobno je prodor kukaca u donji neobrađeni sloj pšenice bio potpuno spriječen. Zaključuje se da se obradom 100 cm dubine površinskog sloja pšenice s 0,5 g dijatomejske zemlje Protect-It® po kilogramu postiže zadovoljavajuća zaštita i sprječava infestacija robe sa S. oryzae, T. castaneum i R. dominica. Da bi se znatno umanjio negativni utjecaj dijatomejske zemlje na smanjenje hektolitarske mase, predlaže se obrada samo dijela zrnene mase, ne više od 20% od ukupne mase robe. Smatra se da se ovim postupkom uskladištena neinfestirana pšenica može na zadovoljavajući način zaštititi od štetnika skladišta i da ovaj postupak može uspješno zamijeniti obradu cjelokupne mase robe s dijatomejskom zemljom. S obzirom na gotovo zanemarivu toksičnost i opasnost dijatomejske zemlje za ljudsko zdravlje, uz djelotvornost na kukce koja je usporediva s djelotvornošću znatno otrovnijih i opasnijih sintetskih insekticida koji se rabe u skladištima, važno je naglasiti da je uporaba dijatomejske zemlje u zaštiti uskladištenih žitarica prihvatljiva kako za zaštitu ljudskog zdravlja tako i za očuvanje okoliša

Cost-effectiveness analysis in R using a multi-state modelling survival analysis framework: a tutorial

This tutorial provides a step-by-step guide to performing cost-effectiveness analysis using a multi-state modelling approach. Alongside the tutorial we provide easy-to-use functions in the statistics package R. We argue this multi-state modelling approach using a package such as R has advantages over approaches where models are built in a spreadsheet package. In particular, using a syntax-based approach means there is a written record of what was done and the calculations are transparent. Reproducing the analysis is straightforward as the syntax just needs to be run again. The approach can be thought of as an alternative way to build a Markov decision analytic model, which also has the option to use a state-arrival extended approach if the Markov property does not hold. In the state-arrival extended multi-state model a covariate that represents patients’ history is included allowing the Markov property to be tested. We illustrate the building of multi-state survival models, making predictions from the models and assessing fits. We then proceed to perform a cost-effectiveness analysis including deterministic and probabilistic sensitivity analyses. Finally, we show how to create two common methods of visualising the results, namely cost-effectiveness planes and cost-effectiveness acceptability curves. The analysis is implemented entirely within R. It is based on adaptions to functions in the existing R package mstate, to accommodate parametric multi-state modelling which facilitates extrapolation of survival curves

Development and evaluation of a technique for evaluating riparian vegetation change in the tallgrass prairie

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file viewed on (June 30, 2006)Includes bibliographical references.Vita.Thesis (M.S.) University of Missouri-Columbia 2004.Dissertations, Academic -- University of Missouri--Columbia -- Fisheries and wildlife.North America's tallgrass prairie region is one of the world's most endangered ecosystems. Recent management and research efforts have focused on the effects of anthropogenic change to upland components of the tallgrass prairie, however, little is known regarding change to riparian vegetation. Nevertheless, riparian vegetation habitat plays a significant role in the conservation of both terrestrial and aquatic biodiversity; furthermore, anthropogenic modifications to this system have often occurred before the onset of modern ecological inventories. As a result, managers, planners, and policy makers often make decisions that impact riparian vegetation without sufficient information regarding presettlement vegetation. To provide data that can be used in the decision-making process, we developed and evaluated a technique to characterize historic and contemporary riparian vegetation, within a Geographic Information System (GIS). The methodology provides an objective, scientific approach to providing the necessary data to make informed management, planning, and restoration decisions regarding riparian systems. Our findings suggest that, contrary to previous research and speculation, historic riparian zones contained a significant amount of prairie, and that the extent varied among watersheds. We found no remaining riparian prairie today. This research contributes baseline data to facilitate the evaluation of vegetation change and the success of management and restoration efforts

Probabilistic estimates of climate change impacts on UK water resources

Climate change will increase temperatures and change rainfall across the UK. In turn, this will modify patterns of river flow and groundwater recharge, affecting the availability of water. There have been many studies of the impact of climate change on river flows in the UK, but coverage has been uneven and methods have varied. Consequently, it has been very difficult to compare different locations and hard to identify appropriate adaptation responses