Russia's huge Gazprom struggles to adjust to new realities

International Nuclear Information System (INIS)

Korchemkin, M.B.

1993-01-01

The Russian joint-stock company Gazprom, successor to Gazprom of the former U.S.S.R. and the world's largest gas company, faces a crisis of direction in the middle years of this decade. With recent memories of annual additions to its transmission pipeline capacity of more than 6,200 miles, Gazprom officials must face the economic and operational realities that call for rehabilitation projects rather than new construction. Additionally, the overall demand for natural gas in the former Soviet Union (FSU) is leveling as the economies and energy use of all customer countries are declining and gas has already supplanted oil nearly energy-where possible. With the European gas market showing limited space for additional gas, Gazprom's major task in the short-term must be to maintain current production and supply levels. The paper discusses reserves and production, the transmission system, gas exports, the costs of Russian gas, Gazprom's prospects, and major obstacles

Gazprom looks for means to finance its gas pipelines

International Nuclear Information System (INIS)

Anon.

1997-01-01

The Russian Gazprom natural gas company wants to solve its short range problems in order to develop its activities in Western Europe rapidly. The transportation capacities remain the main problem of Gazprom which is looking for new financing for the development and maintenance of its pipelines network. Several pipeline projects are under study but the occidental banks remain suspicious and wait for the settlement of internal lawsuits between Gazprom and the Russian state. Short paper. (J.S.)

Gazprom Market for energy installations using fuel cells

Energy Technology Data Exchange (ETDEWEB)

Galitskiy, Yu.V.

1996-04-01

The Gazprom RAO [Russian joint-stock company] is a major industrial and financial complex whose job is to provide gas for the national economy of Russia, as well as to supply it under international and intergovernmental agreements. The existing capacity of its production structures and high level of scientific potential allow Gazprom to forecast the future with confidence.

Gazprom : Kremli rusikas ja rahamasin hoiab haardes poolt Euroopat / Krister Paris

Index Scriptorium Estoniae

Paris, Krister, 1977-

2005-01-01

Maailma suurimast gaasitootjast Gazprom, mis autori sõnul on kujunemas Vene võimude üheks olulisemaks välispoliitiliseks tööriistaks, kehastades Moskva mõju samal määral kui Vene armee. Lisad: Gazpromi nähtamatu käsi Leedus; Venemaa mõjuvõimsaim; Gazprom paisub veelgi. Diagramm: Veel erakätes. Kaart: Gazpromi haardes. Tabel: Gazprom

Russian Gas for Europe. Creating Access and Choice. Underpinning Russia's gas export strategy with Gazprom's infrastructure investments

International Nuclear Information System (INIS)

Smeenk, T.

2010-07-01

This study deals with Gazprom's investment strategy regarding Russia's gas exports and export market behaviour, with a focus on European infrastructure projects, in a the geopolitical context. Because of its large gas reserves, Russia is well-positioned to take advantage of gas exports even as it faces possible competition from other gas suppliers and uncertain gas demand. Gas export earnings are an important source of income for Russia. As a government-controlled firm, Gazprom depends to a large extent on Europe for its hard-currency income. For Russia and Gazprom, the stream of income from gas exports and its expansion are economically vital. In this regard, gas export infrastructures such as Nord and South Stream could act as important instruments to expand Gazprom's market share in current markets and in growth markets. This study uses a real-option game model to assess the overall value of gas infrastructures in the face of demand uncertainties and potential competition. The result of this approach illustrates the strategic-economic character of Gazprom's infrastructure investments in possibly creating a first-mover's advantage. Yet, the model is of a highly stylised nature. Therefore, other aspects should be taken into account in assessing gas infrastructure investments. Besides the goal of possibly expanding Gazprom's market share, infrastructure investments could serve to mitigate overall transit risks. However, Gazprom's organisational constraints in realising gas infrastructures could put into question the rationale of such investments. In addition, Gazprom's position as well as that of Russian gas may be pressured by European (regulatory) policy in favour of alternative gas and other energy sources. The desired market outcomes for Gazprom have an impact on the prioritisation of Russian investments in the gas value chain.

Gazprom: the European idealism to the test of Russian realism

International Nuclear Information System (INIS)

Dasseleer, P.H.

2009-01-01

This geopolitical book analyses a major element of the future Russian-European relations. Gazprom is not only a giant gas company but a real 'centre of power' complementary to the Russian government. Gazprom is responsible for 86% of the Russian national production of gas and owns 70% of the reserves. It is involved in oil, power generation, and nuclear energy too and employs more than 300.000 people. It contributes to 25% of Russia's budget. This study tries to decipher the temporal and geographical approach of Gazprom with respect to its field of action which is the European continent. This analysis puts forward Gazprom's energy policy, with its logical and rational organization in front of an hesitating and idealistic Western Europe. It offers some paths of reflexion about the future intra-continental negotiations aiming at ensuring the security of gas supplies in Europe. The Russian exports, often considered as a threat, would easily become an opportunity for the geo-political consolidation of the Old Continent. (J.S.)

Gazprom: internal structure, management principles and financial flows

International Nuclear Information System (INIS)

Kryukov, Valery; Moe, Arild.

1996-01-01

Gazprom is responsible for over 95% of total Russian natural gas production and is one of the largest companies in the world. As well as being of major importance in the Russian domestic energy balance, it is also the largest gas trader in the world, supplying about half the gas imported into western and east-central Europe. The scale of these external activities means that the terms on which it supplies gas to its customers will have an impact on business beyond the gas industry. This study investigates the roots of the company and analyses its current organisation, management structure and financial flows. The main topics covered are: the Russian gas industry in the Soviet era; the organisational structure of Gazprom after privatisation; pricing policy; the company's financial position; Gazprom in relation to the domestic economy and the outside world. (9 figures; 7 tables). (author)

Gazprom teeb reformi: Ukrainal on aeg gaasipliidid nurka visata / Heiki Suurkask

Index Scriptorium Estoniae

Suurkask, Heiki, 1972-

2009-01-01

Autor leiab, et Ukraina pole 2006. a. kriisist midagi õppinud, maagaasi tarbimine on veelgi suurenenud. Gaasihinna tõusu korral hakatakse Ukrainas ilmselt üha enam loobuma gaasipliitidest ja -boileritest ning niimoodi kaotaks Gazprom ühe oma suurema turu. Gazprom üritab kõrgemat gaasihinda saavutada ka SRÜ maades. Diagrammid

Gazprom the new russian empire

International Nuclear Information System (INIS)

Cosnard, D.

2004-01-01

The author analyzes the economical and political impacts of the great Gazprom group, leader in the russian energy domain, in Russia. Already number one of the world gas industry, this Group is becoming the right-hand of the Kremlin. Thus the author wonders on this empire transparency and limits. (A.L.B.)

Gazprom tõrjub võimalikku konkurenti / Vahur Koorits

Index Scriptorium Estoniae

Koorits, Vahur, 1981-

2009-01-01

Eesti põhjarannikule kavandatud veeldatud maagaasi ehk LNG terminali ees seisab rida takistusi, suurimaks probleemiks on Gazprom. Vt. samas: Veeldatud maagaasi terminal annaks sõltumatuse Gazpromist

Gazprom joins scramble for West-Africa

International Nuclear Information System (INIS)

Ten Hoedt, R.

2008-01-01

Gazprom has announced that it wants to become involved in gas production in West-Africa. A normal business decision for a company that wants to be a global player, say some analysts. Others are worried that the Russian move is intended to sabotage Europe's strategy to diversify its supplies

Gazprom in Europe: a Business Doomed to Fail?

International Nuclear Information System (INIS)

Bros, Aurelie

2014-07-01

The construction of what is nowadays called European energy policy is an ongoing process that officially started with the creation of the European Coal and Steel Community in 1951, and has not yet been entirely finalized. It took several decades to move from a Community composed of six countries to a policy - not fully fledged - intended to strengthen as much as possible cohesion between 28 EU member states in the energy sector. The European gas sector has been progressively liberalized since the 1990's. The leitmotivs of European energy policy have been and continue to be the opening-up of national gas markets, the enhancement of both competition and transparency, and the struggle against monopolies. The Third Energy Package creates, among others, the concept of European network codes, applied throughout Europe. The European Union (EU) has also developed a European energy policy based on three pillars: security of supply, environment, and competitiveness. The history of Gazprom, a long-standing economic partner of Europe, is a series of constant adaptations - with varying degrees of success-to both European market conditions and dialogue with all parties involved in the gas business across the continent. The Russian company thrived during the 1990's and 2000's in an environment where the main characteristics inherited from the 1970's and the 1980's were retained (i.e. long-term contracts with prices indexed to substitute energy prices-primarily oil-and destination clauses in a context of low competition) while any new opportunity, generally offered by the liberalization and opening-up of national gas markets, was constantly sized up. The company has encountered some difficulties; adaptation is not always that easy. Consequently, some Gazprom officials regularly ask whether European energy policy is a policy intended to challenge Russia and Gazprom. Adaptation is challenging as it brings into question the former business model. Furthermore

Focus on Russia. Russia versus Gazprom

International Nuclear Information System (INIS)

Mehdiyeva, N.

2008-01-01

Rising domestic demand and the depletion of traditional natural gas fields mean that Russia will have to make choices as to where to send its gas. But the priorities of Gazprom and the Russian government often conflict, a trend likely exacerbated by the deteriorating relationship between Russia and the West

Gazprom joins scramble for West-Africa

Energy Technology Data Exchange (ETDEWEB)

Ten Hoedt, R.

2008-03-15

Gazprom has announced that it wants to become involved in gas production in West-Africa. A normal business decision for a company that wants to be a global player, say some analysts. Others are worried that the Russian move is intended to sabotage Europe's strategy to diversify its supplies.

EU Gas Liberalization as a Driver of Gazprom's Strategies?

International Nuclear Information System (INIS)

Locatelli, C.

2008-01-01

Russia and Gazprom's natural gas strategies on the European market are the result of the uncertainties (volumes, prices) created by the liberalization of the EU natural gas market. The company's policy of asset acquisition, begun at the end of the 1990's, the multiplication of export networks, as well as the desire to preserve long-term contracts while benefiting from new contractual opportunities are all clear illustrations of this strategy. Yet the industrial and commercial strategies that Gazprom may develop cannot discount geopolitical issues. Therefore, Vladimir Putin's desire to place hydrocarbons at the service of his economic and foreign policies, notably by making use of large, internationalized companies owned primarily by the state, remains in the background. (author)

The Gazprom-Naftogaz Stockholm Arbitration Awards. Time for Settlements and Responsible Behaviour

International Nuclear Information System (INIS)

Eyl-Mazzega, Marc-Antoine

2018-01-01

The signing in January 2009 of the gas supply and transit contracts between Gazprom and Naftogaz marked a turning point in Russian-Ukrainian gas relations: yearly intergovernmental, last minute and non-transparent winter deals were replaced by a predictable, long term commercial relationship. Naftogaz quickly turned into Gazprom's most profitable customer, taking the largest gas volumes at the Russian border and paying a higher price than German customers for example,[1] while Naftogaz obtained a satisfying gas transit tariff. At least, the January 2009 gas crisis had resulted in this key improvement for the security of Ukrainian and European gas supplies. Yet almost ever since then, the contract terms had been disputed as the Ukrainian economy could no more afford the high gas prices, the high mandatory yearly purchase volumes and as transit volumes were below contract provisions especially when the Nord Stream pipeline was commissioned. Several temporary pricing or flexibility arrangements in the form of political or patronage-type concessions had been made under President Yanukovych. But following the 2014 regime change in Ukraine and payment arrears by Naftogaz, Gazprom sought to recover unpaid debts and the new reform and business-minded Naftogaz management filed a case at the Arbitration Institute of the Stockholm Chamber of Commerce (hereafter, the Institute) as the parties did not agree on a review of the contract terms. Claims and counter claims quickly reached sky high levels, leading to the most sensitive European gas arbitration involving Gazprom. Mutual claims amounted to about USD 125 billion and had the potential to bankrupt both Gazprom and Naftogaz. At the same time, Gazprom and Naftogaz proved responsible in agreeing to winter package agreements brokered by the European Commission that enabled continued temporary Russian gas exports to Ukraine and safe transit to Europe. Following four years of procedure, the Institute has finally made two

Gazprom lõhub Peterburi silueti pilvedeni / Ave Randviir

Index Scriptorium Estoniae

Randviir, Ave, 1981-

2006-01-01

Gazprom City ärikvartali arhitektuurikonkursil osalejate seas oli kuulsaid arhitekte nagu Jaques Herzog ja Pierre de Meuron, Massimiliano Fuksas, Daniel Libeskind, Jean Nouvel, Rem Koolhaas, Richard Rodgers ja Suurbritannia arhitektuuribüroo RMJM. Peterburi Arhitektide Liidu arvates hävitab kavandatav pilvelõhkuja linna ajaloolise silueti

Eesti vetesse trügiv Gazprom saab suure relvastatud üksuse / Lauri Linnamäe

Index Scriptorium Estoniae

Linnamäe, Lauri

2007-01-01

Ilmunud ka: Postimees : na russkom jazõke, 17. apr. 2007, lk. 5. Vene gaasimonopol Gazprom saab Vene riigilt ilmselt volitused Läänemerre plaanitava gaasijuhtme kaitsmiseks tuhandeist võitlejaist koosneva hästirelvastatud eraarmee loomiseks, riigiduumas algatatud vastavast seaduseelnõust. Parlamendiliikmete Igor Gräzini ja Marko Mihkelsoni arvamused sõjalis-poliitilistest ohtudest. Skeem: Gazprom võib tuua eraarmee Vene-Saksa gaasijuhet kaitsma

Gazprom ähvardab hinnatõusuga / Erki Freiberg

Index Scriptorium Estoniae

Freiberg, Erki

2005-01-01

Ilmunud ka: Delovõje Vedomosti 15. juuni lk. 4. Gaasitootja Gazprom tahab kehtestada Eestile ning Lätile gaasi müümisel sama hinnataseme, mis kehtib ka teistel Euroopa Liidu liikmesriikidel, see tähendaks kahekordset hinnatõusu. Lisa: Hinnatõus muudaks gaasikütte elektriküttega võrreldavaks. Vt. samas: Eesti Gaasi juht: hüppelist hinnatõusu ei tule

Gazprom hoiatas euroliitu gaasi kinnikeeramisega / Erkki Bahovski

Index Scriptorium Estoniae

Bahovski, Erkki, 1970-

2006-01-01

Gazprom manitses Euroopa Liitu mitte blokeerima ettevõtte ärihuve, ähvardades vastasel korral suunata oma gaasitarned mujale, teatas Briti majandusleht Financial Times. Euroopa Komisjon vastas Gazpromi ähvardustele, et kompanii peaks oma lepinguid täitma ning mitte ähvardama Euroopa gaasitarnete ümbersuunamisega. Samas möönis eurokomisjon taas, et euroliit sõltub välismaistest energiahiidudest

Gazprom lõpetab energiat nõudva sõpruse Valgevenega / Krister Paris

Index Scriptorium Estoniae

Paris, Krister, 1977-

2006-01-01

Gazprom kavatseb tõsta Valgevenele müüdava gaasi hinda maailmaturu tasemele, sellel võivad Valgevene majandusele ja poliitikale olla ebameeldivad tagajärjed. Lisa: Paariale läheb hinnatõus kalliks

EU commissioner says Gazprom won't be exception to trade rules

Index Scriptorium Estoniae

2007-01-01

EL-i konkurentsivolinik Neelie Kroes hoiatas, et Gazprom võib loovutada oma osakud Baltimaade energiaettevõtetes ja Läänemere gaasijuhtmes, kui EL-i liikmesriigid võtavad vastu uue strateegilise energiaplaani, mis edendab konkurentsi

Gazprom vibutas valimisjärgse Ukraina suunas energiarelva / Krister Paris

Index Scriptorium Estoniae

Paris, Krister, 1977-

2007-01-01

Gazprom nõuab Ukrainalt väidetavat 1,3 miljardi dollari suurust võlga. Lääne analüütikute arvates on tegemist Moskva näpuviibutusega: kui võimule tuleb Julia Timoshenko, võib Ukrainal halvasti minna. Lisa: "Oranzhid" napilt võidukad

Euroopa Liidus firmasid kahmav Gazprom teisi Venemaa turule ei lase / Krister Paris

Index Scriptorium Estoniae

Paris, Krister, 1977-

2006-01-01

EL tahab, et Venemaa ratifitseeriks energiaharta, mis võimaldaks Euroopa kompaniidel hakata ise Venemaa gaasi eksportima, Venemaa aga välismaist konkurentsi ei soovi. Samas on Gazprom huvitatud Suurbritannia suurima gaasivarustaja Centrica ostust ning tahab sisenenda ise gaasi tootva Hollandi turule. Lisa: Venemaa teine energiahoob: riiklik Rosneft. Vt. samas: Gaasitoodangu kasvatamine pole veel Gazpromi huvides

Gazprom on the European Market: In Search of the Balance between the Principles of Competition and Energy Security

Directory of Open Access Journals (Sweden)

Valery I. Salygin

2014-01-01

Full Text Available The article analyses the position of Gazprom on the key export market - the market of the European Union. Situation on the EU gas market changed considerably because of an imbalance between supply and demand. Gazprom had to make price concessions for almost all of the main consumers of Russian gas in Europe, and also had to allow European consumers to break one of the key provisions of long-term contracts - "take or pay" clause. Besides disputes at the corporate level significant differences still remain about the well-known Third energy package, which effectively prohibits Gazprom to own and operate gas pipelines on the territory of the EU, as well as binding it to provide a third party access to gas pipelines. The implementation of Third package provisions on function unbundling by some EU Member States in the most rigid version may contradict bilateral international agreements of Russia with the EU Member States, primarily agreements on investment protection. Possible reasons underlying the investigation initiated by the European Commission against Gazprom in connection with a possible violation ofEU competition rules are examined. The paper investigates legal, political and economic aspects of contemporary regime of gas cooperation, particularly restriction of reexport, linkage between gas and oil prices, pricing based on long-term contracts and spot markets. The paper concludes that Russia and the EU need to elaborate a comprehensive document that would ensure the stability of the regulatory environment of energy cooperation and would reflect the balance of interests of producers and consumers. This document should equally ensure highly competitive environment and guarantees of security of supply in the short and long term.

Rosneft, Gazprom and the Government: the Decision-Making Triangle on Russia's Energy Policy

International Nuclear Information System (INIS)

Baev, Pavel

2014-03-01

Russia finds itself exposed to many risks in the fast-moving global revolution in energy affairs, and cannot avail of its opportunities despite its unique combination of natural resources and experience in their exploitation. It has entered the phase of economic stagnation, and the under-performance of the energy sector is one of the key determinants of the durability of this trend. Energy export can no longer be wielded as a heavy-impact instrument of foreign policy, and the squabbles for shrinking oil and gas revenues form a key driver of the evolving crisis of the petro-authoritarian regime built by President Vladimir Putin. Escalating problems in the Russian energy sector are caused by the system of decision-making on oil and gas matters, in which Putin acts as a supreme arbiter in the flexible triangle formed by the government and two super-large state companies-Gazprom and Rosneft. It is the imperative of checking the decline of budget revenues that determines the priority in government policy of greater confiscation of profits and heavier taxation of the energy business. This squeeze on the interests of energy 'oligarchs' provokes them to appeal to Putin for tax breaks, which he is increasingly reluctant to grant, given the need to pursue an active social policy. The constant flow of insoluble issues makes Putin irritable and generally less engaged with the energy business than he used to be. Gazprom's notorious inefficiency in its core business emboldens competitors to capture greater shares of the domestic market and to demand exemptions from its export monopoly. Putin is loath to carry this political liability but remains reluctant to contemplate reforms that would amount to un-bundling of this conglomerate. Rosneft under the control of Igor Sechin has become the champion of the Russian oil industry, executing a series of acquisitions and signing a series of deals with Western 'majors'. Putin's benevolence is the key to the

Gain control mechanisms in spinal motoneurons

Directory of Open Access Journals (Sweden)

Michael David Johnson

2014-07-01

Full Text Available Motoneurons provide the only conduit for motor commands to reach muscles. For many years, motoneurons were in fact considered to be little more than passive wires. Systematic studies in the past 25 years however have clearly demonstrated that the intrinsic electrical properties of motoneurons are under strong neuromodulatory control via multiple sources. The discovery of potent neuromodulation from the brainstem and its ability to change the gain of motoneurons shows that the passive view of the motor output stage is no longer tenable. A mechanism for gain control at the motor output stage makes good functional sense considering our capability of generating an enormous range of forces, from very delicate (e.g. putting in a contact lens to highly forceful (emergency reactions. Just as sensory systems need gain control to deal with a wide dynamic range of inputs, so to might motor output need gain control to deal with the wide dynamic range of the normal movement repertoire. Two problems emerge from the potential use of the brainstem monoaminergic projection to motoneurons for gain control. First, the projection is highly diffuse anatomically, so that independent control of the gains of different motor pools is not feasible. In fact, the system is so diffuse that gain for all the motor pools in a limb likely increases in concert. Second, if there is a system that increases gain, probably a system to reduce gain is also needed. In this review, we summarize recent studies that show local inhibitory circuits within the spinal cord, especially reciprocal and recurrent inhibition, have the potential to solve both of these problems as well as constitute another source of gain modulation.

Controlling gain one photon at a time

Science.gov (United States)

Schwartz, Gregory W; Rieke, Fred

2013-01-01

Adaptation is a salient property of sensory processing. All adaptational or gain control mechanisms face the challenge of obtaining a reliable estimate of the property of the input to be adapted to and obtaining this estimate sufficiently rapidly to be useful. Here, we explore how the primate retina balances the need to change gain rapidly and reliably when photons arrive rarely at individual rod photoreceptors. We find that the weakest backgrounds that decrease the gain of the retinal output signals are similar to those that increase human behavioral threshold, and identify a novel site of gain control in the retinal circuitry. Thus, surprisingly, the gain of retinal signals begins to decrease essentially as soon as background lights are detectable; under these conditions, gain control does not rely on a highly averaged estimate of the photon count, but instead signals from individual photon absorptions trigger changes in gain. DOI: http://dx.doi.org/10.7554/eLife.00467.001 PMID:23682314

A modified Cournot model of the natural gas market in the European Union: Mixed-motives delegation in a politicized environment

International Nuclear Information System (INIS)

Jansen, Thijs; Lier, Arie van; Witteloostuijn, Arjen van; Boon von Ochssée, Tim

2012-01-01

With Gazprom gaining prominence as the major supplier of natural gas in the European Union, the European gas market becomes more politicized. We assume that Gazprom's interest as a state monopolist is not only to maximize profit, but also to seek market power, presumably because this contributes to the geopolitical power of Russia at large. We introduce a modeling tool, so-called strategic delegation games, to analyze the implications of Gazprom's operation in the EU. By way of illustration, we model the case where Gazprom competes against two profit-maximizing rivals: Algerian Sonatrach and Norwegian Statoil. We prove that if Gazprom serves any of a comprehensive type of nonprofit objectives, the outcome is beneficial for the EU's consumers, as Gazprom's behavior shifts volumes up and brings prices down. - Highlights: ► We model the natural gas market in the EU. ► The fact that the major gas supplier Russia/Gazprom has nonprofit incentives is beneficial for EU's consumers. ► The nonprofit incentives increase Russia's market share and decrease the profits of its rivals.

Predictive Variable Gain Iterative Learning Control for PMSM

Directory of Open Access Journals (Sweden)

Huimin Xu

2015-01-01

Full Text Available A predictive variable gain strategy in iterative learning control (ILC is introduced. Predictive variable gain iterative learning control is constructed to improve the performance of trajectory tracking. A scheme based on predictive variable gain iterative learning control for eliminating undesirable vibrations of PMSM system is proposed. The basic idea is that undesirable vibrations of PMSM system are eliminated from two aspects of iterative domain and time domain. The predictive method is utilized to determine the learning gain in the ILC algorithm. Compression mapping principle is used to prove the convergence of the algorithm. Simulation results demonstrate that the predictive variable gain is superior to constant gain and other variable gains.

A wide range and high speed automatic gain control

International Nuclear Information System (INIS)

Tacconi, E.; Christiansen, C.

1993-05-01

Automatic gain control (AGC) techniques have been largely used since the beginning of electronics, but in most of the applications the dynamic response is slow compared with the carrier frequency. The problem of developing an automatic gain control with high dynamic response and wide control range simultaneously is analyzed in this work. An ideal gain control law, with the property that the total loop gain remains constant independent of the carrier amplitude, is obtained. The resulting AGC behavior is compared by computer simulations with a linear multiplier AGC. The ideal gain control law can be approximated using a transconductance amplifier. A practical circuit that has been used at CERN in the radio frequency loops of the Booster Synchrotron is presented. The circuit has high speed and 80-dB gain control range

Bumpless Transfer between Observer-based Gain Scheduled Controllers

DEFF Research Database (Denmark)

Bendtsen, Jan Dimon; Stoustrup, Jakob; Trangbæk, Klaus

2005-01-01

This paper deals with bumpless transfer between a number of observer-based controllers in a gain scheduling architecture. Linear observer-based controllers are designed for a number of linear approximations of a nonlinear system in a set of operating points, and gain scheduling control can...

An output amplitude configurable wideband automatic gain control with high gain step accuracy

International Nuclear Information System (INIS)

He Xiaofeng; Ye Tianchun; Mo Taishan; Ma Chengyan

2012-01-01

An output amplitude configurable wideband automatic gain control (AGC) with high gain step accuracy for the GNSS receiver is presented. The amplitude of an AGC is configurable in order to cooperate with baseband chips to achieve interference suppression and be compatible with different full range ADCs. And what's more, the gain-boosting technology is introduced and the circuit is improved to increase the step accuracy. A zero, which is composed by the source feedback resistance and the source capacity, is introduced to compensate for the pole. The AGC is fabricated in a 0.18 μm CMOS process. The AGC shows a 62 dB gain control range by 1 dB each step with a gain error of less than 0.2 dB. The AGC provides 3 dB bandwidth larger than 80 MHz and the overall power consumption is less than 1.8 mA, and the die area is 800 × 300 μm 2 . (semiconductor integrated circuits)

Gain-Scheduled Control of a Fossil-Fired Power Plant Boiler

DEFF Research Database (Denmark)

Hangstrup, M.; Stoustrup, Jakob; Andersen, Palle

1999-01-01

-scheduling which interpolates between unstable controllers is not allowed using traditional schemes. The results show that a considerable optimization of the conventional controlled system is obtainable. Also the gain-scheduled optimizing controller is seen to have a superior performance compared to the fixed LTI......In this paper the objective is to optimize the control of a coal fired 250 MW power plant boiler. The conventional control system is supplemented with a multivariable optimizing controller operating in parallel with the conventional control system. Due to the strong dependence of the gains...... and dynamics upon the load, it is beneficial to consider a gain-scheduling control approach. Optimization using complex mu synthesis results in unstable LTI controllers in some operating points of the boiler. A recent gain-scheduling approach allowing for unstable fixed LTI controllers is applied. Gain...

Gain control network conditions in early sensory coding.

Directory of Open Access Journals (Sweden)

Eduardo Serrano

Full Text Available Gain control is essential for the proper function of any sensory system. However, the precise mechanisms for achieving effective gain control in the brain are unknown. Based on our understanding of the existence and strength of connections in the insect olfactory system, we analyze the conditions that lead to controlled gain in a randomly connected network of excitatory and inhibitory neurons. We consider two scenarios for the variation of input into the system. In the first case, the intensity of the sensory input controls the input currents to a fixed proportion of neurons of the excitatory and inhibitory populations. In the second case, increasing intensity of the sensory stimulus will both, recruit an increasing number of neurons that receive input and change the input current that they receive. Using a mean field approximation for the network activity we derive relationships between the parameters of the network that ensure that the overall level of activity of the excitatory population remains unchanged for increasing intensity of the external stimulation. We find that, first, the main parameters that regulate network gain are the probabilities of connections from the inhibitory population to the excitatory population and of the connections within the inhibitory population. Second, we show that strict gain control is not achievable in a random network in the second case, when the input recruits an increasing number of neurons. Finally, we confirm that the gain control conditions derived from the mean field approximation are valid in simulations of firing rate models and Hodgkin-Huxley conductance based models.

Phase and gain control policies for robust active vibration control of flexible structures

International Nuclear Information System (INIS)

Zhang, K; Ichchou, M N; Scorletti, G; Mieyeville, F

2013-01-01

The interest of this paper is to develop a general and systematic robust control methodology for active vibration control of flexible structures. For this purpose, first phase and gain control policies are proposed to impose qualitative frequency-dependent requirements on the controller to consider a complete set of control objectives. Then the proposed control methodology is developed by employing phase and gain control policies in the dynamic output feedback H ∞  control: according to the set of control objectives, phase and gain control policies incorporate necessary weighting functions and determine them in a rational and systematic way; on the other hand, with the appropriate weighting functions efficient H ∞  control algorithms can automatically realize phase and gain control policies and generate a satisfactory H ∞  controller. The proposed control methodology can be used for both SISO and MIMO systems with collocated or non-collocated sensors and actuators. In this paper, it is validated on a non-collocated piezoelectric cantilever beam. Both numerical simulations and experimental results demonstrate the effectiveness of the proposed control methodology. (paper)

L2-gain and passivity techniques in nonlinear control

CERN Document Server

van der Schaft, Arjan

2017-01-01

This standard text gives a unified treatment of passivity and L2-gain theory for nonlinear state space systems, preceded by a compact treatment of classical passivity and small-gain theorems for nonlinear input-output maps. The synthesis between passivity and L2-gain theory is provided by the theory of dissipative systems. Specifically, the small-gain and passivity theorems and their implications for nonlinear stability and stabilization are discussed from this standpoint. The connection between L2-gain and passivity via scattering is detailed. Feedback equivalence to a passive system and resulting stabilization strategies are discussed. The passivity concepts are enriched by a generalised Hamiltonian formalism, emphasising the close relations with physical modeling and control by interconnection, and leading to novel control methodologies going beyond passivity. The potential of L2-gain techniques in nonlinear control, including a theory of all-pass factorizations of nonlinear systems, and of parametrization...

Robust Optimal Adaptive Control Method with Large Adaptive Gain

Science.gov (United States)

Nguyen, Nhan T.

2009-01-01

In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient stability robustness. Simulations were conducted for a damaged generic transport aircraft with both standard adaptive control and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model while maintaining a sufficient time delay margin.

Gain Scheduling for the Orion Launch Abort Vehicle Controller

Science.gov (United States)

McNamara, Sara J.; Restrepo, Carolina I.; Madsen, Jennifer M.; Medina, Edgar A.; Proud, Ryan W.; Whitley, Ryan J.

2011-01-01

One of NASAs challenges for the Orion vehicle is the control system design for the Launch Abort Vehicle (LAV), which is required to abort safely at any time during the atmospheric ascent portion of ight. The focus of this paper is the gain design and scheduling process for a controller that covers the wide range of vehicle configurations and flight conditions experienced during the full envelope of potential abort trajectories from the pad to exo-atmospheric flight. Several factors are taken into account in the automation process for tuning the gains including the abort effectors, the environmental changes and the autopilot modes. Gain scheduling is accomplished using a linear quadratic regulator (LQR) approach for the decoupled, simplified linear model throughout the operational envelope in time, altitude and Mach number. The derived gains are then implemented into the full linear model for controller requirement validation. Finally, the gains are tested and evaluated in a non-linear simulation using the vehicles ight software to ensure performance requirements are met. An overview of the LAV controller design and a description of the linear plant models are presented. Examples of the most significant challenges with the automation of the gain tuning process are then discussed. In conclusion, the paper will consider the lessons learned through out the process, especially in regards to automation, and examine the usefulness of the gain scheduling tool and process developed as applicable to non-Orion vehicles.

Commutated automatic gain control system

Science.gov (United States)

Yost, S. R.

1982-01-01

A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

Fuzzy gain scheduling of velocity PI controller with intelligent learning algorithm for reactor control

International Nuclear Information System (INIS)

Kim, Dong Yun; Seong, Poong Hyun

1996-01-01

In this study, we proposed a fuzzy gain scheduler with intelligent learning algorithm for a reactor control. In the proposed algorithm, we used the gradient descent method to learn the rule bases of a fuzzy algorithm. These rule bases are learned toward minimizing an objective function, which is called a performance cost function. The objective of fuzzy gain scheduler with intelligent learning algorithm is the generation of adequate gains, which minimize the error of system. The condition of every plant is generally changed as time gose. That is, the initial gains obtained through the analysis of system are no longer suitable for the changed plant. And we need to set new gains, which minimize the error stemmed from changing the condition of a plant. In this paper, we applied this strategy for reactor control of nuclear power plant (NPP), and the results were compared with those of a simple PI controller, which has fixed gains. As a result, it was shown that the proposed algorithm was superior to the simple PI controller

Contrast gain control in first- and second-order motion perception.

Science.gov (United States)

Lu, Z L; Sperling, G

1996-12-01

A novel pedestal-plus-test paradigm is used to determine the nonlinear gain-control properties of the first-order (luminance) and the second-order (texture-contrast) motion systems, that is, how these systems' responses to motion stimuli are reduced by pedestals and other masking stimuli. Motion-direction thresholds were measured for test stimuli consisting of drifting luminance and texture-contrast-modulation stimuli superimposed on pedestals of various amplitudes. (A pedestal is a static sine-wave grating of the same type and same spatial frequency as the moving test grating.) It was found that first-order motion-direction thresholds are unaffected by small pedestals, but at pedestal contrasts above 1-2% (5-10 x pedestal threshold), motion thresholds increase proportionally to pedestal amplitude (a Weber law). For first-order stimuli, pedestal masking is specific to the spatial frequency of the test. On the other hand, motion-direction thresholds for texture-contrast stimuli are independent of pedestal amplitude (no gain control whatever) throughout the accessible pedestal amplitude range (from 0 to 40%). However, when baseline carrier contrast increases (with constant pedestal modulation amplitude), motion thresholds increase, showing that gain control in second-order motion is determined not by the modulator (as in first-order motion) but by the carrier. Note that baseline contrast of the carrier is inherently independent of spatial frequency of the modulator. The drastically different gain-control properties of the two motion systems and prior observations of motion masking and motion saturation are all encompassed in a functional theory. The stimulus inputs to both first- and second-order motion process are normalized by feedforward, shunting gain control. The different properties arise because the modulator is used to control the first-order gain and the carrier is used to control the second-order gain.

Fuzzy gain scheduling of velocity PI controller with intelligent learning algorithm for reactor control

International Nuclear Information System (INIS)

Kim, Dong Yun

1997-02-01

In this research, we propose a fuzzy gain scheduler (FGS) with an intelligent learning algorithm for a reactor control. In the proposed algorithm, the gradient descent method is used in order to generate the rule bases of a fuzzy algorithm by learning. These rule bases are obtained by minimizing an objective function, which is called a performance cost function. The objective of the FGS with an intelligent learning algorithm is to generate adequate gains, which minimize the error of system. The proposed algorithm can reduce the time and efforts required for obtaining the fuzzy rules through the intelligent learning function. The evolutionary programming algorithm is modified and adopted as the method in order to find the optimal gains which are used as the initial gains of FGS with learning function. It is applied to reactor control of nuclear power plant (NPP), and the results are compared with those of a conventional PI controller with fixed gains. As a result, it is shown that the proposed algorithm is superior to the conventional PI controller

Design of Gain Scheduling Control Using State Derivative Feedback

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Lázaro Ismael Hardy Llins

2017-01-01

Full Text Available In recent years, the study of systems subject to time-varying parameters has awakened the interest of many researchers. The gain scheduling control strategy guarantees a good performance for systems of this type and also is considered as the simplest to deal with problems of this nature. Moreover, the class of systems in which the state derivative signals are easier to obtain than the state signals, such as in the control for reducing vibrations in a mechanical system, has gained an important hole in control theory. Considering those ideas, we propose sufficient conditions via LMI for designing a gain scheduling controller using state derivative feedback. The D-stability methodology was used for improving the performance of the transitory response. Practical implementation in an active suspension system and comparison with other methods validates the efficiency of the proposed strategy.

A Gain-Scheduling PI Control Based on Neural Networks

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Stefania Tronci

2017-01-01

Full Text Available This paper presents a gain-scheduling design technique that relies upon neural models to approximate plant behaviour. The controller design is based on generic model control (GMC formalisms and linearization of the neural model of the process. As a result, a PI controller action is obtained, where the gain depends on the state of the system and is adapted instantaneously on-line. The algorithm is tested on a nonisothermal continuous stirred tank reactor (CSTR, considering both single-input single-output (SISO and multi-input multi-output (MIMO control problems. Simulation results show that the proposed controller provides satisfactory performance during set-point changes and disturbance rejection.

CONTROLLING AS A MECHANISM TO INCREASE THE EFFICIENCY OF MANAGEMENT ENTERPRISES OF FUEL-ENERGY COMPLEX

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M. A. Ostashkin

2013-01-01

Full Text Available This article discusses the possibility of application of controlling as mechanism of increasing the efficiency of management of enterprises of fuel- energy complex. The research was conducted on the materials of the JSC «Gazprom».

Fuzzy gain scheduling of velocity PI controller with intelligent learning algorithm for reactor control

International Nuclear Information System (INIS)

Dong Yun Kim; Poong Hyun Seong; .

1997-01-01

In this research, we propose a fuzzy gain scheduler (FGS) with an intelligent learning algorithm for a reactor control. In the proposed algorithm, the gradient descent method is used in order to generate the rule bases of a fuzzy algorithm by learning. These rule bases are obtained by minimizing an objective function, which is called a performance cost function. The objective of the FGS with an intelligent learning algorithm is to generate gains, which minimize the error of system. The proposed algorithm can reduce the time and effort required for obtaining the fuzzy rules through the intelligent learning function. It is applied to reactor control of nuclear power plant (NPP), and the results are compared with those of a conventional PI controller with fixed gains. As a result, it is shown that the proposed algorithm is superior to the conventional PI controller. (author)

Contrast Gain Control Model Fits Masking Data

Science.gov (United States)

Watson, Andrew B.; Solomon, Joshua A.; Null, Cynthia H. (Technical Monitor)

1994-01-01

We studied the fit of a contrast gain control model to data of Foley (JOSA 1994), consisting of thresholds for a Gabor patch masked by gratings of various orientations, or by compounds of two orientations. Our general model includes models of Foley and Teo & Heeger (IEEE 1994). Our specific model used a bank of Gabor filters with octave bandwidths at 8 orientations. Excitatory and inhibitory nonlinearities were power functions with exponents of 2.4 and 2. Inhibitory pooling was broad in orientation, but narrow in spatial frequency and space. Minkowski pooling used an exponent of 4. All of the data for observer KMF were well fit by the model. We have developed a contrast gain control model that fits masking data. Unlike Foley's, our model accepts images as inputs. Unlike Teo & Heeger's, our model did not require multiple channels for different dynamic ranges.

Adaptive Gain Scheduled Semiactive Vibration Control Using a Neural Network

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Kazuhiko Hiramoto

2018-01-01

Full Text Available We propose an adaptive gain scheduled semiactive control method using an artificial neural network for structural systems subject to earthquake disturbance. In order to design a semiactive control system with high control performance against earthquakes with different time and/or frequency properties, multiple semiactive control laws with high performance for each of multiple earthquake disturbances are scheduled with an adaptive manner. Each semiactive control law to be scheduled is designed based on the output emulation approach that has been proposed by the authors. As the adaptive gain scheduling mechanism, we introduce an artificial neural network (ANN. Input signals of the ANN are the measured earthquake disturbance itself, for example, the acceleration, velocity, and displacement. The output of the ANN is the parameter for the scheduling of multiple semiactive control laws each of which has been optimized for a single disturbance. Parameters such as weight and bias in the ANN are optimized by the genetic algorithm (GA. The proposed design method is applied to semiactive control design of a base-isolated building with a semiactive damper. With simulation study, the proposed adaptive gain scheduling method realizes control performance exceeding single semiactive control optimizing the average of the control performance subject to various earthquake disturbances.

Time Difference Amplifier with Robust Gain Using Closed-Loop Control

Science.gov (United States)

Nakura, Toru; Mandai, Shingo; Ikeda, Makoto; Asada, Kunihiro

This paper presents a Time Difference Amplifier (TDA) that amplifies the input time difference into the output time difference. Cross coupled chains of variable delay cells with the same number of stages are applicable for TDA, and the gain is adjusted via the closed-loop control. The TDA was fabricated using 65nm CMOS and the measurement results show that the time difference gain is 4.78 at a nominal power supply while the designed gain is 4.0. The gain is stable enough to be less than 1.4% gain shift under ±10% power supply voltage fluctuation.

Gain Scheduling Control based on Closed-Loop System Identification

DEFF Research Database (Denmark)

Bendtsen, Jan Dimon; Trangbæk, Klaus

the first and a second operating point is identified in closed-loop using system identification methods with open-loop properties. Next, a linear controller is designed for this linearised model, and gain scheduling control can subsequently be achieved by interpolating between each controller...

Application of gain scheduling to the control of batch bioreactors

Science.gov (United States)

Cardello, Ralph; San, Ka-Yiu

1987-01-01

The implementation of control algorithms to batch bioreactors is often complicated by the inherent variations in process dynamics during the course of fermentation. Such a wide operating range may render the performance of fixed gain PID controllers unsatisfactory. In this work, a detailed study on the control of batch fermentation is performed. Furthermore, a simple batch controller design is proposed which incorporates the concept of gain-scheduling, a subclass of adaptive control, with oxygen uptake rate as an auxiliary variable. The control of oxygen tension in the biorector is used as a vehicle to convey the proposed idea, analysis and results. Simulation experiments indicate significant improvement in controller performance can be achieved by the proposed approach even in the presence of measurement noise.

Gain-assisted control of the Goos-Haenchen shift

Energy Technology Data Exchange (ETDEWEB)

Ziauddin,; Qamar, Sajid [Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)

2011-11-15

A gain-assisted model is considered to study the Goos-Haenchen (GH) shift behavior in the reflected and transmitted light. In this model, a probe light is incident on a cavity containing three-level dilute gaseous atomic medium. The atom-field interaction follows two-photon Raman transitions, and the dielectric susceptibility of the medium exhibits dispersion and gain properties [L. J. Wang, A. Kuzmich, and A. Dogariu, Nature (London) 406, 227 (2000)]. Under appropriate conditions, two gain peaks are observed with anomalous dispersion between the peaks, whereas normal dispersion can be observed at and around the gain maxima. The manipulation of the detuning associated with the probe light field which interacts with the intracavity medium during its propagation through the cavity can lead to a control over negative and positive GH shift in the reflected and transmitted light beam via the anomalous and normal dispersion of the medium.

Perception of gain in U.S.-Soviet arms control

International Nuclear Information System (INIS)

D'Anieri, P.J.

1991-01-01

Most current work in the field of international cooperation focuses on the resolution of the 'prisoners dilemma.' Such work begins by assuming that the issues under consideration are defined by absolute gains, where both sides can gain simultaneously. But the realist strand of international relations literature holds that this assumption is suspect - that international relations are usually characterized by relative gains, where gain for one side comes only at the others expense. The model developed here uses the question of absolute versus relative gains not as a theoretical assumption, but as a variable to be measured empirically. The hypothesis is that whether or not the US and the Soviet Union cooperate to limit arms competition is largely determined by whether the two sides define the issue in question as one of absolute or relative gains. The 'perception of gain' hypothesis is compared to explanations at the levels of the international system (rational choice), domestic politics, and individual belief systems. Three case studies are used to compare the strengths and weaknesses of each hypothesis. The findings confirmed that perception of gain is an important independent variable affecting arms control outcomes, but none of the theories were completely supported or rejected

Gain Scheduling of Observer-Based Controllers with Integral Action

DEFF Research Database (Denmark)

Trangbæk, Klaus; Stoustrup, Jakob; Bendtsen, Jan Dimon

2006-01-01

 This paper presents a method for continuous gain scheduling of  observer-based controllers with integral action. Given two stabilising controllers for a given system, explicit state space formulae are presented, allowing to change gradually from one  controller to the other while preserving...

Mechanisms of Gain Control by Voltage-Gated Channels in Intrinsically-Firing Neurons

Science.gov (United States)

Patel, Ameera X.; Burdakov, Denis

2015-01-01

Gain modulation is a key feature of neural information processing, but underlying mechanisms remain unclear. In single neurons, gain can be measured as the slope of the current-frequency (input-output) relationship over any given range of inputs. While much work has focused on the control of basal firing rates and spike rate adaptation, gain control has been relatively unstudied. Of the limited studies on gain control, some have examined the roles of synaptic noise and passive somatic currents, but the roles of voltage-gated channels present ubiquitously in neurons have been less explored. Here, we systematically examined the relationship between gain and voltage-gated ion channels in a conductance-based, tonically-active, model neuron. Changes in expression (conductance density) of voltage-gated channels increased (Ca2+ channel), reduced (K+ channels), or produced little effect (h-type channel) on gain. We found that the gain-controlling ability of channels increased exponentially with the steepness of their activation within the dynamic voltage window (voltage range associated with firing). For depolarization-activated channels, this produced a greater channel current per action potential at higher firing rates. This allowed these channels to modulate gain by contributing to firing preferentially at states of higher excitation. A finer analysis of the current-voltage relationship during tonic firing identified narrow voltage windows at which the gain-modulating channels exerted their effects. As a proof of concept, we show that h-type channels can be tuned to modulate gain by changing the steepness of their activation within the dynamic voltage window. These results show how the impact of an ion channel on gain can be predicted from the relationship between channel kinetics and the membrane potential during firing. This is potentially relevant to understanding input-output scaling in a wide class of neurons found throughout the brain and other nervous systems

Gain Scheduling of PID Controller Based on Fuzzy Systems

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Singh Sandeep

2016-01-01

Full Text Available This paper aims to utilize fuzzy rules and reasoning to determine the controller parameters and the PID controller generates the control signal. The objective of this study is to simulate the proposed scheme on various processes and arrive at results providing better response of the system when compared with best industrial auto-tuning technique: Ziegler-Nichols. The proposed scheme is based upon the Ultimate Gain (Ku and the Period (Tu of the system. The error and rate of change in error gains are tuned manually to get the desired response using LabVIEW. This can also be done with various optimization techniques. A thumb rule for choosing the ranges for Kc, Kd and Ki has been obtained experimentally.

A Uniform Voltage Gain Control for Alignment Robustness in Wireless EV Charging

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Yabiao Gao

2015-08-01

Full Text Available The efficiency of wireless power transfer is sensitive to the horizontal and vertical distances between the transmitter and receiver coils due to the magnetic coupling change. To address the output voltage variation and efficiency drop caused by misalignment, a uniform voltage gain frequency control is implemented to improve the power delivery and efficiency of wireless power transfer under misalignment. The frequency is tuned according to the amplitude and phase-frequency characteristics of coupling variations in order to maintain a uniform output voltage in the receiver coil. Experimental comparison of three control methods, including fixed frequency control, resonant frequency control, and the proposed uniform gain control was conducted and demonstrated that the uniform voltage gain control is the most robust method for managing misalignment in wireless charging applications.

Asynchronous L1-gain control of uncertain switched positive linear systems with dwell time.

Science.gov (United States)

Li, Yang; Zhang, Hongbin

2018-04-01

In this paper, dwell time (DT) stability, L 1 -gain performance analysis and asynchronous L 1 -gain controller design problems of uncertain switched positive linear systems (SPLSs) are investigated. Via a time-scheduled multiple linear co-positive Lyapunov function (TSMLCLF) approach, convex sufficient conditions of DT stability and L 1 -gain performance of SPLSs with interval and polytopic uncertainties are presented. Furthermore, by utilizing the feature that the TSMLCLF keeps decreasing even if the controller is running asynchronously with the system, the asynchronous L 1 -gain controller design problem of SPLSs with interval and polytopic uncertainties is investigated. Convex sufficient conditions of the existence of time-varying asynchronous state-feedback controller which can ensure the closed-loop system's positivity, stability and L 1 -gain performance are established, and the controller gain matrices can be calculated instantaneously online. The obtained L 1 -gain in the paper is standard. All the results are presented in terms of linear programming. A practical example is provided to show the effectiveness of the results. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Structured, Gain-Scheduled Control of Wind Turbines

DEFF Research Database (Denmark)

Adegas, Fabiano Daher

2013-01-01

Improvements in cost-effectiveness and reliability of wind turbines is a constant in the industry. This requires new knowledge and systematic methods for analyzing and designing the interaction of structural dynamics, aerodynamics, and controllers. This thesis presents novel methods and theoretical....... Robustness and fault-tolerance capabilities are also important properties, which should be considered in the design process. Novel gain-scheduling and robust control methods that adapt to variations in the operational conditions of the wind turbine are proposed under the linear parameter-varying (LPV...... intuitive and physical specifications for vibration control, such as minimum damping and decay rate of aeroelastic modes. Moreover, the number of weighting functions and consequently the order of the final controller is reduced. Inspired by this application, theoretical control developments are presented...

Coherence and interlimb force control: Effects of visual gain.

Science.gov (United States)

Kang, Nyeonju; Cauraugh, James H

2018-03-06

Neural coupling across hemispheres and homologous muscles often appears during bimanual motor control. Force coupling in a specific frequency domain may indicate specific bimanual force coordination patterns. This study investigated coherence on pairs of bimanual isometric index finger force while manipulating visual gain and task asymmetry conditions. We used two visual gain conditions (low and high gain = 8 and 512 pixels/N), and created task asymmetry by manipulating coefficient ratios imposed on the left and right index finger forces (0.4:1.6; 1:1; 1.6:0.4, respectively). Unequal coefficient ratios required different contributions from each hand to the bimanual force task resulting in force asymmetry. Fourteen healthy young adults performed bimanual isometric force control at 20% of their maximal level of the summed force of both fingers. We quantified peak coherence and relative phase angle between hands at 0-4, 4-8, and 8-12 Hz, and estimated a signal-to-noise ratio of bimanual forces. The findings revealed higher peak coherence and relative phase angle at 0-4 Hz than at 4-8 and 8-12 Hz for both visual gain conditions. Further, peak coherence and relative phase angle values at 0-4 Hz were larger at the high gain than at the low gain. At the high gain, higher peak coherence at 0-4 Hz collapsed across task asymmetry conditions significantly predicted greater signal-to-noise ratio. These findings indicate that a greater level of visual information facilitates bimanual force coupling at a specific frequency range related to sensorimotor processing. Copyright © 2018 Elsevier B.V. All rights reserved.

Subtractive, divisive and non-monotonic gain control in feedforward nets linearized by noise and delays.

Science.gov (United States)

Mejias, Jorge F; Payeur, Alexandre; Selin, Erik; Maler, Leonard; Longtin, André

2014-01-01

The control of input-to-output mappings, or gain control, is one of the main strategies used by neural networks for the processing and gating of information. Using a spiking neural network model, we studied the gain control induced by a form of inhibitory feedforward circuitry-also known as "open-loop feedback"-, which has been experimentally observed in a cerebellum-like structure in weakly electric fish. We found, both analytically and numerically, that this network displays three different regimes of gain control: subtractive, divisive, and non-monotonic. Subtractive gain control was obtained when noise is very low in the network. Also, it was possible to change from divisive to non-monotonic gain control by simply modulating the strength of the feedforward inhibition, which may be achieved via long-term synaptic plasticity. The particular case of divisive gain control has been previously observed in vivo in weakly electric fish. These gain control regimes were robust to the presence of temporal delays in the inhibitory feedforward pathway, which were found to linearize the input-to-output mappings (or f-I curves) via a novel variability-increasing mechanism. Our findings highlight the feedforward-induced gain control analyzed here as a highly versatile mechanism of information gating in the brain.

Subtractive, divisive and non-monotonic gain control in feedforward nets linearized by noise and delays

Directory of Open Access Journals (Sweden)

Jorge F Mejias

2014-02-01

Full Text Available The control of input-to-output mappings, or gain control, is one of the main strategies used by neural networks for the processing and gating of information. Using a spiking neural network model, we studied the gain control induced by a form of inhibitory feedforward circuitry — also known as ’open-loop feedback’ —, which has been experimentally observed in a cerebellum-like structure in weakly electric fish. We found, both analytically and numerically, that this network displays three different regimes of gain control: subtractive, divisive, and non-monotonic. Subtractive gain control was obtained when noise is very low in the network. Also, it was possible to change from divisive to non-monotonic gain control by simply modulating the strength of the feedforward inhibition, which may be achieved via long-term synaptic plasticity. The particular case of divisive gain control has been previously observed in vivo in weakly electric fish. These gain control regimes were robust to the presence of temporal delays in the inhibitory feedforward pathway, which were found to linearize the input-to-output mappings (or f-I curves via a novel variability-increasing mechanism. Our findings highlight the feedforward-induced gain control analyzed here as a highly versatile mechanism of information gating in the brain.

Gain-Scheduled Model Predictive Control of Wind Turbines using Laguerre Functions

DEFF Research Database (Denmark)

Adegas, Fabiano Daher; Wisniewski, Rafal; Larsen, Lars Finn Sloth

2014-01-01

This paper presents a systematic approach to design gain-scheduled predictive controllers for wind turbines. The predictive control law is based on Laguerre functions to parameterize control signals and a parameter-dependent cost function that is analytically determined from turbine data....... These properties facilitate the design of speed controllers by placement of the closed-loop poles (when constraints are not active) and systematic adaptation towards changes in the operating point. Vibration control of undamped modes is achieved by imposing a certain degree of stability to the closed-loop system....... The approach can be utilized to the design of new controllers and to represent existing gain-scheduled controllers as predictive controllers. The numerical example and simulations illustrate the design of a speed controller augmented with active damping of the tower fore-aft displacement....

Adaptive Neuro-Fuzzy Based Gain Controller for Erbium-Doped Fiber Amplifiers

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YUCEL, M.

2017-02-01

Full Text Available Erbium-doped fiber amplifiers (EDFA must have a flat gain profile which is a very important parameter such as wavelength division multiplexing (WDM and dense WDM (DWDM applications for long-haul optical communication systems and networks. For this reason, it is crucial to hold a stable signal power per optical channel. For the purpose of overcoming performance decline of optical networks and long-haul optical systems, the gain of the EDFA must be controlled for it to be fixed at a high speed. In this study, due to the signal power attenuation in long-haul fiber optic communication systems and non-equal signal amplification in each channel, an automatic gain controller (AGC is designed based on the adaptive neuro-fuzzy inference system (ANFIS for EDFAs. The intelligent gain controller is implemented and the performance of this new electronic control method is demonstrated. The proposed ANFIS-based AGC-EDFA uses the experimental dataset to produce the ANFIS-based sets and the rule base. Laser diode currents are predicted within the accuracy rating over 98 percent with the proposed ANFIS-based system. Upon comparing ANFIS-based AGC-EDFA and experimental results, they were found to be very close and compatible.

Nonlinear model-based robust control of a nuclear reactor using adaptive PIF gains and variable structure controller

International Nuclear Information System (INIS)

Park, Moon Ghu; Cho, Nam Zin

1993-01-01

A Nonlinear model-based Hybrid Controller (NHC) is developed which consists of the adaptive proportional-integral-feedforward (PIF) gains and variable structure controller. The controller has the robustness against modeling uncertainty and is applied to the trajectory tracking control of single-input, single-output nonlinear systems. The essence of the scheme is to divide the control into four different terms. Namely, the adaptive P-I-F gains and variable structure controller are used to accomplish the specific control actions by each terms. The robustness of the controller is guaranteed by the feedback of estimated uncertainty and the performance specification given by the adaptation of PIF gains using the second method of Lyapunov. The variable structure controller is incorporated to regulate the initial peak of the tracking error during the parameter adaptation is not settled yet. The newly developed NHC method is applied to the power tracking control of a nuclear reactor and the simulation results show great improvement in tracking performance compared with the conventional model-based control methods. (Author)

Gain scheduling controller for pitch control of a TRMS system

Science.gov (United States)

Bhagyalakshmi, R.; Rashmi, GP; Jaganatha Pandian, B.

2017-11-01

Gain scheduling is a control technique which is applied for the control of non-linear systems by using a family of linear controllers at different operating points so as to increase the range of operation of the process. The dynamics of any nonlinear system changes with respect to operating points. These operating points are characterized by one or more variables known as scheduling variables. In such cases, we linearize the system at different equilibrium points. Due to the high amount of non-linearities and complexity in the aerodynamic design, modelling of other unmanned aerial vehicles have been replaced here with twin rotor system. The linearized system is then controlled by using PID controllers which are designed with respect to the obtained operating points. Linearizing of the non-linear system, designing and tuning of PID are being implemented using different MATLAB functions.

Interval type-2 fuzzy gain-adaptive controller of a Doubly Fed ...

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... Interval Type-2 Fuzzy Gain Adaptive IP (IT2FGAIP) controller and a conventional IP controller ... and an adaptive IP controller is proposed for the speed control of DFIM in the presence of ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

Learning to walk with an adaptive gain proportional myoelectric controller for a robotic ankle exoskeleton.

Science.gov (United States)

Koller, Jeffrey R; Jacobs, Daniel A; Ferris, Daniel P; Remy, C David

2015-11-04

Robotic ankle exoskeletons can provide assistance to users and reduce metabolic power during walking. Our research group has investigated the use of proportional myoelectric control for controlling robotic ankle exoskeletons. Previously, these controllers have relied on a constant gain to map user's muscle activity to actuation control signals. A constant gain may act as a constraint on the user, so we designed a controller that dynamically adapts the gain to the user's myoelectric amplitude. We hypothesized that an adaptive gain proportional myoelectric controller would reduce metabolic energy expenditure compared to walking with the ankle exoskeleton unpowered because users could choose their preferred control gain. We tested eight healthy subjects walking with the adaptive gain proportional myoelectric controller with bilateral ankle exoskeletons. The adaptive gain was updated each stride such that on average the user's peak muscle activity was mapped to maximal power output of the exoskeleton. All subjects participated in three identical training sessions where they walked on a treadmill for 50 minutes (30 minutes of which the exoskeleton was powered) at 1.2 ms(-1). We calculated and analyzed metabolic energy consumption, muscle recruitment, inverse kinematics, inverse dynamics, and exoskeleton mechanics. Using our controller, subjects achieved a metabolic reduction similar to that seen in previous work in about a third of the training time. The resulting controller gain was lower than that seen in previous work (β=1.50±0.14 versus a constant β=2). The adapted gain allowed users more total ankle joint power than that of unassisted walking, increasing ankle power in exchange for a decrease in hip power. Our findings indicate that humans prefer to walk with greater ankle mechanical power output than their unassisted gait when provided with an ankle exoskeleton using an adaptive controller. This suggests that robotic assistance from an exoskeleton can allow

The design of programme-controlled gain and linear pulse amplifier

International Nuclear Information System (INIS)

Guan Xuemei; Chen Chunkai; Northeast Normal Univ., Changchun; Qiao Shuang; Zhou Chuansheng

2006-01-01

The authors have designed a kind of new-style programme-controlled gain and linear pulse amplifier with accurate gausses of CR-RC-CR shaping circuit structure. The use of non-volatile digital electric potential device and accurate operational amplifier makes the circuit structure simple greatly, makes the ability stronger that resists assault. It can realize multistage gain in succession and make the drift of temperature low and make the linearity of pulse well. (authors)

Reward-driven modulation of adaptive control: How prospective monetary gains interact with unpredictable control demands

NARCIS (Netherlands)

Marien, Hans; Aarts, Henk; Custers, Ruud

2014-01-01

Shifting attention is an effortful control process and incurs a cost on the cognitive system. Previous research suggests that rewards, such as monetary gains, will selectively enhance the ability to shift attention when this demand for control is explicitly cued. Here, we hypothesized that

Humanoid Walking Robot: Modeling, Inverse Dynamics, and Gain Scheduling Control

Directory of Open Access Journals (Sweden)

Elvedin Kljuno

2010-01-01

Full Text Available This article presents reference-model-based control design for a 10 degree-of-freedom bipedal walking robot, using nonlinear gain scheduling. The main goal is to show concentrated mass models can be used for prediction of the required joint torques for a bipedal walking robot. Relatively complicated architecture, high DOF, and balancing requirements make the control task of these robots difficult. Although linear control techniques can be used to control bipedal robots, nonlinear control is necessary for better performance. The emphasis of this work is to show that the reference model can be a bipedal walking model with concentrated mass at the center of gravity, which removes the problems related to design of a pseudo-inverse system. Another significance of this approach is the reduced calculation requirements due to the simplified procedure of nominal joint torques calculation. Kinematic and dynamic analysis is discussed including results for joint torques and ground force necessary to implement a prescribed walking motion. This analysis is accompanied by a comparison with experimental data. An inverse plant and a tracking error linearization-based controller design approach is described. We propose a novel combination of a nonlinear gain scheduling with a concentrated mass model for the MIMO bipedal robot system.

Gain-scheduled Linear Quadratic Control of Wind Turbines Operating at High Wind Speed

DEFF Research Database (Denmark)

Østergaard, Kasper Zinck; Stoustrup, Jakob; Brath, Per

2007-01-01

This paper addresses state estimation and linear quadratic (LQ) control of variable speed variable pitch wind turbines. On the basis of a nonlinear model of a wind turbine, a set of operating conditions is identified and a LQ controller is designed for each operating point. The controller gains...... are then interpolated linearly to get a control law for the entire operating envelope. A nonlinear state estimator is designed as a combination of two unscented Kalman filters and a linear disturbance estimator. The gain-scheduling variable (wind speed) is then calculated from the output of these state estimators...

Tuning and performance evaluation of PID controller for superheater steam temperature control of 200 MW boiler using gain phase assignment algorithm

Science.gov (United States)

Begum, A. Yasmine; Gireesh, N.

2018-04-01

In superheater, steam temperature is controlled in a cascade control loop. The cascade control loop consists of PI and PID controllers. To improve the superheater steam temperature control the controller's gains in a cascade control loop has to be tuned efficiently. The mathematical model of the superheater is derived by sets of nonlinear partial differential equations. The tuning methods taken for study here are designed for delay plus first order transfer function model. Hence from the dynamical model of the superheater, a FOPTD model is derived using frequency response method. Then by using Chien-Hrones-Reswick Tuning Algorithm and Gain-Phase Assignment Algorithm optimum controller gains has been found out based on the least value of integral time weighted absolute error.

External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE

Science.gov (United States)

Zahodne, Laura B.; Meyer, Oanh L.; Choi, Eunhee; Thomas, Michael L.; Willis, Sherry L.; Marsiske, Michael; Gross, Alden L.; Rebok, George W.; Parisi, Jeanine M.

2015-01-01

Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training. PMID:26237116

Redesign of a Variable-Gain Output Feedback Longitudinal Controller Flown on the High-Alpha Research Vehicle (HARV)

Science.gov (United States)

Ostroff, Aaron J.

1998-01-01

This paper describes a redesigned longitudinal controller that flew on the High-Alpha Research Vehicle (HARV) during calendar years (CY) 1995 and 1996. Linear models are developed for both the modified controller and a baseline controller that was flown in CY 1994. The modified controller was developed with three gain sets for flight evaluation, and several linear analysis results are shown comparing the gain sets. A Neal-Smith flying qualities analysis shows that performance for the low- and medium-gain sets is near the level 1 boundary, depending upon the bandwidth assumed, whereas the high-gain set indicates a sensitivity problem. A newly developed high-alpha Bode envelope criterion indicates that the control system gains may be slightly high, even for the low-gain set. A large motion-base simulator in the United Kingdom was used to evaluate the various controllers. Desired performance, which appeared to be satisfactory for flight, was generally met with both the low- and medium-gain sets. Both the high-gain set and the baseline controller were very sensitive, and it was easy to generate pilot-induced oscillation (PIO) in some of the target-tracking maneuvers. Flight target-tracking results varied from level 1 to level 3 and from no sensitivity to PIO. These results were related to pilot technique and whether actuator rate saturation was encountered.

Robust, Gain-Scheduled Control of Wind Turbines

DEFF Research Database (Denmark)

Østergaard, Kasper Zinck

Wind turbines are today large and efficient machines, which are combined into wind farms operating on par with conventional power plants. When looking back, this is significantly different from the status only a few years ago, when wind turbines were sold mainly to private people. This change...... in turbine owners has resulted in a new focus on operational reliability instead of turbine size. This research deals with investigating model-based gain-scheduling control of wind turbines by use of linear parameter varying (LPV) methods. The numerical challenges grow quickly with the model size...

Reliable gain-scheduled control of discrete-time systems and its application to CSTR model

Science.gov (United States)

Sakthivel, R.; Selvi, S.; Mathiyalagan, K.; Shi, Y.

2016-10-01

This paper is focused on reliable gain-scheduled controller design for a class of discrete-time systems with randomly occurring nonlinearities and actuator fault. Further, the nonlinearity in the system model is assumed to occur randomly according to a Bernoulli distribution with measurable time-varying probability in real time. The main purpose of this paper is to design a gain-scheduled controller by implementing a probability-dependent Lyapunov function and linear matrix inequality (LMI) approach such that the closed-loop discrete-time system is stochastically stable for all admissible randomly occurring nonlinearities. The existence conditions for the reliable controller is formulated in terms of LMI constraints. Finally, the proposed reliable gain-scheduled control scheme is applied on continuously stirred tank reactor model to demonstrate the effectiveness and applicability of the proposed design technique.

External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE.

Science.gov (United States)

Zahodne, Laura B; Meyer, Oanh L; Choi, Eunhee; Thomas, Michael L; Willis, Sherry L; Marsiske, Michael; Gross, Alden L; Rebok, George W; Parisi, Jeanine M

2015-09-01

Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training. (c) 2015 APA, all rights reserved).

Gain Scheduling Control of an Islanded Microgrid Voltage

Directory of Open Access Journals (Sweden)

Haritza Camblong

2014-07-01

Full Text Available The aim of this research study has been to design a gain scheduling (GS digital controller in order to control the voltage of an islanded microgrid in the presence of fast varying loads (FVLs, and to compare it to a robust controller. The inverter which feeds the microgrid is connected to it through an inductance-capacitor-inductance (LCL filter. The oscillatory and nonlinear behaviour of the plant is analyzed in the whole operating zone. Afterwards, the design of the controllers which contain two loops in cascade are described. The first loop concerns the current control, while the second is linked to the voltage regulation. Two controllers, one defined as Robust and another one as GS controller, are designed for the two loops, emphasizing in their robustness and their ability to damp the oscillatory plant behaviour. To finish, some simulations are carried out to study and compare the two kinds of controllers in different operating points. The results show that both controllers damp the oscillatory behaviour of the plant in closed loop (CL, and that the GS controller ensures a better rejection of current disturbances from FVLs.

Divisive gain modulation of motoneurons by inhibition optimizes muscular control

DEFF Research Database (Denmark)

Vestergaard, Mikkel; Berg, Rune W.

2015-01-01

unclear whether the motoneuron gain, i.e., the slope of the transformation between synaptic input and spiking output, is also modulated to reduce variability in force. To address this issue, we use turtle hindlimb scratching as a model for fine motor control, since this behavior involves precise limb...... movement to rub the location of somatic nuisance touch. We recorded intracellularly from motoneurons in a reduced preparation where the limbs were removed to increase mechanical stability and the motor nerve activity served as a surrogate for muscle force. We found that not only is the gain of motoneurons...

Adaptive fuzzy dynamic surface control for the chaotic permanent magnet synchronous motor using Nussbaum gain

Energy Technology Data Exchange (ETDEWEB)

Luo, Shaohua [School of Automation, Chongqing University, Chongqing 400044, China and College of Mechanical Engineering, Hunan University of Arts and Science, Hunan 415000 (China)

2014-09-01

This paper is concerned with the problem of adaptive fuzzy dynamic surface control (DSC) for the permanent magnet synchronous motor (PMSM) system with chaotic behavior, disturbance and unknown control gain and parameters. Nussbaum gain is adopted to cope with the situation that the control gain is unknown. And the unknown items can be estimated by fuzzy logic system. The proposed controller guarantees that all the signals in the closed-loop system are bounded and the system output eventually converges to a small neighborhood of the desired reference signal. Finally, the numerical simulations indicate that the proposed scheme can suppress the chaos of PMSM and show the effectiveness and robustness of the proposed method.

A current mode feed-forward gain control system for a 0.8 V CMOS hearing aid

Energy Technology Data Exchange (ETDEWEB)

Li Fanyang; Yang Haigang; Liu Fei; Yin Tao, E-mail: yanghg@mail.ie.ac.cn [Institute of Electronics, Chinese Academy of Sciences, Beijing 100080 (China)

2011-06-15

A current mode feed-forward gain control (CMFGC) technique is presented, which is applied in the front-end system of a hearing aid chip. Compared with conventional automatic gain control (AGC), CMFGC significantly improves the total harmonic distortion (THD) by digital gain control. To attain the digital gain control codes according to the extremely weak output signal from the microphone, a rectifier and a state controller implemented in current mode are proposed. A prototype chip has been designed based on a 0.13 {mu}m standard CMOS process. The measurement results show that the supply voltage can be as low as 0.6 V. And with the 0.8 V supply voltage, the THD is improved and below 0.06% (-64 dB) at the output level of 500 mV{sub p-p}, yet the power consumption is limited to 40 {mu}W. In addition, the input referred noise is only 4 {mu}V{sub rms} and the maximum gain is maintained at 33 dB. (semiconductor integrated circuits)

A current mode feed-forward gain control system for a 0.8 V CMOS hearing aid

International Nuclear Information System (INIS)

Li Fanyang; Yang Haigang; Liu Fei; Yin Tao

2011-01-01

A current mode feed-forward gain control (CMFGC) technique is presented, which is applied in the front-end system of a hearing aid chip. Compared with conventional automatic gain control (AGC), CMFGC significantly improves the total harmonic distortion (THD) by digital gain control. To attain the digital gain control codes according to the extremely weak output signal from the microphone, a rectifier and a state controller implemented in current mode are proposed. A prototype chip has been designed based on a 0.13 μm standard CMOS process. The measurement results show that the supply voltage can be as low as 0.6 V. And with the 0.8 V supply voltage, the THD is improved and below 0.06% (-64 dB) at the output level of 500 mV p-p , yet the power consumption is limited to 40 μW. In addition, the input referred noise is only 4 μV rms and the maximum gain is maintained at 33 dB. (semiconductor integrated circuits)

An application of gain-scheduled control using state-space interpolation to hydroactive gas bearings

DEFF Research Database (Denmark)

Theisen, Lukas Roy Svane; Camino, Juan F.; Niemann, Hans Henrik

2016-01-01

with a gain-scheduling strategy using state-space interpolation, which avoids both the performance loss and the increase of controller order associated to the Youla parametrisation. The proposed state-space interpolation for gain-scheduling is applied for mass imbalance rejection for a controllable gas...... bearing scheduled in two parameters. Comparisons against the Youla-based scheduling demonstrate the superiority of the state-space interpolation....

Comparison of gradient methods for gain tuning of a PD controller applied on a quadrotor system

Science.gov (United States)

Kim, Jinho; Wilkerson, Stephen A.; Gadsden, S. Andrew

2016-05-01

Many mechanical and electrical systems have utilized the proportional-integral-derivative (PID) control strategy. The concept of PID control is a classical approach but it is easy to implement and yields a very good tracking performance. Unmanned aerial vehicles (UAVs) are currently experiencing a significant growth in popularity. Due to the advantages of PID controllers, UAVs are implementing PID controllers for improved stability and performance. An important consideration for the system is the selection of PID gain values in order to achieve a safe flight and successful mission. There are a number of different algorithms that can be used for real-time tuning of gains. This paper presents two algorithms for gain tuning, and are based on the method of steepest descent and Newton's minimization of an objective function. This paper compares the results of applying these two gain tuning algorithms in conjunction with a PD controller on a quadrotor system.

An Improved Adaptive-Torque-Gain MPPT Control for Direct-Driven PMSG Wind Turbines Considering Wind Farm Turbulences

Directory of Open Access Journals (Sweden)

Xiaolian Zhang

2016-11-01

Full Text Available Maximum power point tracking (MPPT plays an important role in increasing the efficiency of a wind energy conversion system (WECS. In this paper, three conventional MPPT methods are reviewed: power signal feedback (PSF control, decreased torque gain (DTG control, and adaptive torque gain (ATG control, and their potential challenges are investigated. It is found out that the conventional MPPT method ignores the effect of wind turbine inertia and wind speed fluctuations, which lowers WECS efficiency. Accordingly, an improved adaptive torque gain (IATG method is proposed, which customizes adaptive torque gains and enhances MPPT performances. Specifically, the IATG control considers wind farm turbulences and works out the relationship between the optimal torque gains and the wind speed characteristics, which has not been reported in the literature. The IATG control is promising, especially under the ongoing trend of building wind farms with large-scale wind turbines and at low and medium wind speed sites.

Reward value-based gain control: divisive normalization in parietal cortex.

Science.gov (United States)

Louie, Kenway; Grattan, Lauren E; Glimcher, Paul W

2011-07-20

The representation of value is a critical component of decision making. Rational choice theory assumes that options are assigned absolute values, independent of the value or existence of other alternatives. However, context-dependent choice behavior in both animals and humans violates this assumption, suggesting that biological decision processes rely on comparative evaluation. Here we show that neurons in the monkey lateral intraparietal cortex encode a relative form of saccadic value, explicitly dependent on the values of the other available alternatives. Analogous to extra-classical receptive field effects in visual cortex, this relative representation incorporates target values outside the response field and is observed in both stimulus-driven activity and baseline firing rates. This context-dependent modulation is precisely described by divisive normalization, indicating that this standard form of sensory gain control may be a general mechanism of cortical computation. Such normalization in decision circuits effectively implements an adaptive gain control for value coding and provides a possible mechanistic basis for behavioral context-dependent violations of rationality.

Control of gain in conjugated polymers and perylene dyes

International Nuclear Information System (INIS)

Sheridan, A.

2001-03-01

This thesis presents an investigation into the factors which control the gain and amplification properties in conjugated materials. Conjugated polymers and perylene dyes are highly fluorescent, are easy to process into thin films, and exhibit strong amplification over a broad gain bandwidth making them ideal for use in lasers and amplifiers. The stimulated emission created when thin films of the red emitting polymer poly(2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenvinylene) (MEH-PPV) were photoexcited with high energy laser pulses was investigated. This was characterised by a dramatic narrowing of the emission spectrum which has been assigned to amplified spontaneous emission (ASE). The emission was found to have a gaussian profile and the gain coefficient was found to be 4 cm -1 . The temperature dependence of the absorption, photoluminescence and ASE of films of MEH-PPV was measured. The effect of film morphology on the photophysical properties was investigated by using films cast from two spinning solvents, chlorobenzene (CB) and tetrahydrofuran (THF). Film morphology was found to greatly affect the temperature dependence. A particularly important property is the spectral position of the ASE and the factors which affect it. By controlling the film thickness close to the cut-off thickness for waveguiding in the polymer film it was shown that the peak position of the ASE could be tuned by 31 nm. Modelling of the waveguide modes in the polymer films was used to explain this effect. The cut-off wavelength for each film was measured and good agreement with the theory was found. In order to investigate ways in which energy transfer could be used to control the emission, two perylene dyes were used as a donor-acceptor pair in a host matrix of poly methymethacralate (PMMA). The position of the ASE was found to depend on the acceptor concentration. Measurements of the photoluminescence quantum yield and time-resolved luminescence measurements showed that the energy transfer

The effects of control-display gain on performance of race car drivers in an isometric braking task.

Science.gov (United States)

de Winter, J C F; de Groot, S

2012-12-01

To minimise lap times during car racing, it is important to build up brake forces rapidly and maintain precise control. We examined the effect of the amplification factor (gain) between brake pedal force and a visually represented output value on a driver's ability to track a target value. The test setup was a formula racing car cockpit fitted with an isometric brake pedal. Thirteen racing drivers performed tracking tasks with four control-display gains and two target functions: a step function (35 trials per gain) and a multisine function (15 trials per gain). The control-display gain had only minor effects on root mean-squared error between output value and target value, but it had large effects on build-up speed, overshoot, within-participants variability, and self-reported physical load. The results confirm the hypothesis that choosing an optimum gain involves balancing stability against physical effort.

Central gain control in tinnitus and hyperacusis

Directory of Open Access Journals (Sweden)

Benjamin D Auerbach

2014-10-01

Full Text Available Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement. Enhanced central gain is hypothesized to be a potential mechanism that gives rise to hyperacusis and tinnitus, two debilitating auditory perceptual disorders that afflict millions of individuals. This review will examine the evidence for gain enhancement in the central auditory system in response to cochlear damage. Further, it will address the potential cellular and molecular mechanisms underlying this enhancement and discuss the contribution of central gain enhancement to tinnitus and hyperacusis. Current evidence suggests that multiple mechanisms with distinct temporal and spectral profiles are likely to contribute to central gain enhancement. Dissecting the contributions of these different mechanisms at different levels of the central auditory system is essential for elucidating the role of central gain enhancement in tinnitus and hyperacusis and, most importantly, the development of novel treatments for these disorders.

Central Gain Control in Tinnitus and Hyperacusis

Science.gov (United States)

Auerbach, Benjamin D.; Rodrigues, Paulo V.; Salvi, Richard J.

2014-01-01

Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement. Enhanced central gain is hypothesized to be a potential mechanism that gives rise to hyperacusis and tinnitus, two debilitating auditory perceptual disorders that afflict millions of individuals. This review will examine the evidence for gain enhancement in the central auditory system in response to cochlear damage. Further, it will address the potential cellular and molecular mechanisms underlying this enhancement and discuss the contribution of central gain enhancement to tinnitus and hyperacusis. Current evidence suggests that multiple mechanisms with distinct temporal and spectral profiles are likely to contribute to central gain enhancement. Dissecting the contributions of these different mechanisms at different levels of the central auditory system is essential for elucidating the role of central gain enhancement in tinnitus and hyperacusis and, most importantly, the development of novel treatments for these disorders. PMID:25386157

A low power automatic gain control loop for a receiver

Energy Technology Data Exchange (ETDEWEB)

Li Guofeng; Geng Zhiqing; Wu Nanjian, E-mail: nanjian@red.semi.ac.c [State Key Laboratory for Super lattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

2010-09-15

This paper proposes a new structure to lower the power consumption of a variable gain amplifier (VGA) and keep the linearity of the VGA unchanged. The structure is used in a high rate amplitude-shift keying (ASK) based IF-stage. It includes an automatic gain control (AGC) loop and ASK demodulator. The AGC mainly consists of six-stage VGAs. The IF-stage is realized in 0.18 {mu}m CMOS technology. The measurement results show that the power consumption of the whole system is very low. The system consumes 730 {mu}A while operating at 1.8 V. The minimum ASK signal the system could detect is 0.7 mV (peak to peak amplitude). (semiconductor integrated circuits)

WGC Based Robust and Gain Scheduling PI Controller Design for Condensing Boilers

Directory of Open Access Journals (Sweden)

Cem Onat

2014-05-01

Full Text Available This paper addresses the water temperature PI control in condensing domestic boilers. The main challenge of this process under the controller design perspective is the fact that the dynamics of condensing boilers are strongly affected by the demanded water flow rate. First, a robust PI controller based on weighted geometrical center method is designed that stabilizes and achieves good performance for closed-loop system for a wide range of the water flow rate. Then, it is shown that if the water flow rate information is used to update the controller gains, through a technique known as gain scheduled control, the performance can be significantly improved. Important characteristics of these PI design approaches are that the resulting parameters are calculated numerically without using any graphical method or iterative optimization process and that it guarantees the stability of the closed-loop. Significantly, simulation results have demonstrated that the proposed tuning techniques can perform better for set point changes and load disturbance than other available methods in the literature.

Controlled mass pollination in loblolly pine to increase genetic gains

Science.gov (United States)

F.E. Bridgwater; D.L. Bramlett; T.D. Byram; W.J. Lowe

1998-01-01

Controlled mass pollination (CMP) is one way to increase genetic gains from traditional wind-pollinated seed orchards. Methodology is under development by several forestry companies in the southern USA. Costs of CMP depend on the efficient installation, pollination, and removal of inexpensive paper bags. Even in pilot-scale studies these costs seem reasonable. Net...

Subtractive, divisive and non-monotonic gain control in feedforward nets linearized by noise and delays

OpenAIRE

Mejias, Jorge F.; Payeur, Alexandre; Selin, Erik; Maler, Leonard; Longtin, André

2014-01-01

The control of input-to-output mappings, or gain control, is one of the main strategies used by neural networks for the processing and gating of information. Using a spiking neural network model, we studied the gain control induced by a form of inhibitory feedforward circuitry—also known as “open-loop feedback”—, which has been experimentally observed in a cerebellum-like structure in weakly electric fish. We found, both analytically and numerically, that this network displays three different...

Controlling the gain contribution of background emitters in few-quantum-dot microlasers

Science.gov (United States)

Gericke, F.; Segnon, M.; von Helversen, M.; Hopfmann, C.; Heindel, T.; Schneider, C.; Höfling, S.; Kamp, M.; Musiał, A.; Porte, X.; Gies, C.; Reitzenstein, S.

2018-02-01

We provide experimental and theoretical insight into single-emitter lasing effects in a quantum dot (QD)-microlaser under controlled variation of background gain provided by off-resonant discrete gain centers. For that purpose, we apply an advanced two-color excitation concept where the background gain contribution of off-resonant QDs can be continuously tuned by precisely balancing the relative excitation power of two lasers emitting at different wavelengths. In this way, by selectively exciting a single resonant QD and off-resonant QDs, we identify distinct single-QD signatures in the lasing characteristics and distinguish between gain contributions of a single resonant emitter and a countable number of off-resonant background emitters to the optical output of the microlaser. Our work addresses the important question whether single-QD lasing is feasible in experimentally accessible systems and shows that, for the investigated microlaser, the single-QD gain needs to be supported by the background gain contribution of off-resonant QDs to reach the transition to lasing. Interestingly, while a single QD cannot drive the investigated micropillar into lasing, its relative contribution to the emission can be as high as 70% and it dominates the statistics of emitted photons in the intermediate excitation regime below threshold.

Switched-Observer-Based Adaptive Neural Control of MIMO Switched Nonlinear Systems With Unknown Control Gains.

Science.gov (United States)

Long, Lijun; Zhao, Jun

2017-07-01

In this paper, the problem of adaptive neural output-feedback control is addressed for a class of multi-input multioutput (MIMO) switched uncertain nonlinear systems with unknown control gains. Neural networks (NNs) are used to approximate unknown nonlinear functions. In order to avoid the conservativeness caused by adoption of a common observer for all subsystems, an MIMO NN switched observer is designed to estimate unmeasurable states. A new switched observer-based adaptive neural control technique for the problem studied is then provided by exploiting the classical average dwell time (ADT) method and the backstepping method and the Nussbaum gain technique. It effectively handles the obstacle about the coexistence of multiple Nussbaum-type function terms, and improves the classical ADT method, since the exponential decline property of Lyapunov functions for individual subsystems is no longer satisfied. It is shown that the technique proposed is able to guarantee semiglobal uniformly ultimately boundedness of all the signals in the closed-loop system under a class of switching signals with ADT, and the tracking errors converge to a small neighborhood of the origin. The effectiveness of the approach proposed is illustrated by its application to a two inverted pendulum system.

dc SQUID electronics based on adaptive noise cancellation and a high open-loop gain controller

International Nuclear Information System (INIS)

Seppae, H.

1992-01-01

A low-noise SQUID readout electronics with a high slew rate and an automatic gain control feature has been developed. Flux noise levels of 5x10 -7 Φ 0 /√Hz at 1 kHz and 2x10 -6 Φ 0 /√Hz at 1 Hz have been measured with this readout scheme. The system tolerates sinusoidal disturbances having amplitudes up to 140 Φ 0 at 1 kHz without loosing lock. The electronics utilizes a cooled GaAs FET to control the cancellation of the voltage noise of the room temperature amplifier, a PI 3/2 controller to provide a high open-loop gain at low frequencies, and a square-wave flux and offset voltage modulation to enable automatic control of the noise reduction. The cutoff frequency of the flux-locked-loop is 300 kHz and the feedback gain is more than 130 dB at 10 Hz. (orig.)

Online Dynamic Balance Technology for High Speed Spindle Based on Gain Parameter Adaption and Scheduling Control

Directory of Open Access Journals (Sweden)

Shihai Zhang

2018-06-01

Full Text Available Unbalance vibration is one of the main vibration forms of a high speed machine tool spindle. The overlarge unbalance vibration will have some adverse effects on the working life of the spindle system and the surface quality of the work-piece. In order to reduce the unbalance of a high speed spindle system, a pneumatic online dynamic balance device and its control system are presented in the paper. To improve the balance accuracy and adaptation of the balance system, the gain parameter adaption and scheduling control method are proposed first, and then the different balance effects of the influence coefficient method and the gain scheduling control method are compared through many dynamic balance experiments of the high speed spindle. The experimental results indicate that the gain parameters can be changed timely according to the transformation of the speed and kinetic parameters of the spindle system. The balance accuracy can be improved for a high speed spindle with time-varying characteristics, based on the adaptive gain scheduling control method.

Engine Torque Control of Spark Ignition Engine using Fuzzy Gain Scheduling

OpenAIRE

Aris Triwiyatno

2012-01-01

In the spark ignition engine system, driver convenience is very dependent on satisfying engine torque appropriate with the throttle position given by the driver. Unfortunately, sometimes the fulfillment of engine torque is not in line with fuel saving efforts. This requires the development of high performance and robust power train controllers. One way to potentially meet these performance requirements is to introduce a method of controlling engine torque using fuzzy gain scheduling. By using...

Motivation by potential gains and losses affects control processes via different mechanisms in the attentional network.

Science.gov (United States)

Paschke, Lena M; Walter, Henrik; Steimke, Rosa; Ludwig, Vera U; Gaschler, Robert; Schubert, Torsten; Stelzel, Christine

2015-05-01

Attentional control in demanding cognitive tasks can be improved by manipulating the motivational state. Motivation to obtain gains and motivation to avoid losses both usually result in faster reaction times and stronger activation in relevant brain areas such as the prefrontal cortex, but little is known about differences in the underlying neurocognitive mechanisms of these types of motivation in an attentional control context. In the present functional magnetic resonance imaging (fMRI) study, we tested whether potential gain and loss as motivating incentives lead to overlapping or distinct neural effects in the attentional network, and whether one of these conditions is more effective than the other. A Flanker task with word stimuli as targets and distracters was performed by 115 healthy participants. Using a mixed blocked and event-related design allowed us to investigate transient and sustained motivation-related effects. Participants could either gain money (potential gain) or avoid losing money (potential loss) in different task blocks. Participants showed a congruency effect with increased reaction times for incongruent compared to congruent trials. Potential gain led to generally faster responses compared to the neutral condition and to stronger improvements than potential loss. Potential loss also led to shorter response times compared to the neutral condition, but participants improved mainly during incongruent and not during congruent trials. The event-related fMRI data revealed a main effect of congruency with increased activity in the left inferior frontal gyrus (IFG) and inferior frontal junction area (IFJ), the pre-supplementary motor area (pre-SMA), bilateral insula, intraparietal sulcus (IPS) and visual word form area (VWFA). While potential gain led to increased activity in a cluster of the IFJ and the VWFA only during incongruent trials, potential loss was linked to activity increases in these regions during incongruent and congruent trials. The

Elearning approaches to prevent weight gain in young adults: A randomized controlled study.

Science.gov (United States)

Nikolaou, Charoula Konstantia; Hankey, Catherine Ruth; Lean, Michael Ernest John

2015-12-01

Preventing obesity among young adults should be a preferred public health approach given the limited efficacy of treatment interventions. This study examined whether weight gain can be prevented by online approaches using two different behavioral models, one overtly directed at obesity and the other covertly. A three-group parallel randomized controlled intervention was conducted in 2012-2013; 20,975 young adults were allocated a priori to one control and two "treatment" groups. Two treatment groups were offered online courses over 19 weeks on (1) personal weight control ("Not the Ice Cream Van," NTICV) and, (2) political, environmental, and social issues around food ("Goddess Demetra," "GD"). Control group received no contact. The primary outcome was weight change over 40 weeks. Within-group 40-week weight changes were different between groups (P < 0.001): Control (n = 2,134): +2.0 kg (95% CI = 1.5, 2.3 kg); NTICV (n = 1,810): -1.0 kg (95% CI = -1.3, -0.5); and GD (n = 2,057): -1.35 kg (95% CI = -1.4 to -0.7). Relative risks for weight gain vs. NTICV = 0.13 kg (95% CI = 0.10, 0.15), P < 0.0001; GD = 0.07 kg (95% CI = 0.05, 0.10), P < 0.0001. Both interventions were associated with prevention of the weight gain observed among control subjects. This low-cost intervention could be widely transferable as one tool against the obesity epidemic. Outside the randomized controlled trial setting, it could be enhanced using supporting advertising and social media. © 2015 The Obesity Society.

Gaining control

NARCIS (Netherlands)

Enden, van der E.; Laan, van der R.

2008-01-01

The article reports on the efforts of companies to find a solution for tax risk management, tax accounting and being in control. In trying to find a solution, companies work towards an integrated tax control framework (TCF), a tax risk management and control environment embedded in the internal

Gaining control room habitability margin at the Palisades Plant

International Nuclear Information System (INIS)

Harden, P.A.

1993-01-01

The bounding design-basis accident for control room habitability is the loss-of-coolant accident (LOCA). At Palisades, very little margin existed between the calculated control room operator thyroid dose and the 0.3-Sv (30-rem) limit of Standard Review Plan (SRP) 6.4. Also, a low rate of unfiltered air leakage into the control room during the emergency mode of operation, 5.5 x 10 -3 m 3 /s (11.6 ft 3 /min), was accounted for in the control room habitability analysis. The control room heating, ventilating and air-conditioning system at Palisades has louvered isolation dampers for the normal air intake that are exposed to a negative pressure. Considering the small margin to the thyroid dose limits and the leakage characteristics of louvered dampers, a low allowable rate of unfiltered air in-leakage raised some concern. A significant effort has been initiated to alleviate control room habitability concerns at Palisades. The first step in this effort was to evaluate the calculational models for control room habitability and gain margin through updated analytical methods. To accomplish this, a new radiological consequence analysis for the LOCA was completed

Binocular contrast-gain control for natural scenes: Image structure and phase alignment.

Science.gov (United States)

Huang, Pi-Chun; Dai, Yu-Ming

2018-05-01

In the context of natural scenes, we applied the pattern-masking paradigm to investigate how image structure and phase alignment affect contrast-gain control in binocular vision. We measured the discrimination thresholds of bandpass-filtered natural-scene images (targets) under various types of pedestals. Our first experiment had four pedestal types: bandpass-filtered pedestals, unfiltered pedestals, notch-filtered pedestals (which enabled removal of the spatial frequency), and misaligned pedestals (which involved rotation of unfiltered pedestals). Our second experiment featured six types of pedestals: bandpass-filtered, unfiltered, and notch-filtered pedestals, and the corresponding phase-scrambled pedestals. The thresholds were compared for monocular, binocular, and dichoptic viewing configurations. The bandpass-filtered pedestal and unfiltered pedestals showed classic dipper shapes; the dipper shapes of the notch-filtered, misaligned, and phase-scrambled pedestals were weak. We adopted a two-stage binocular contrast-gain control model to describe our results. We deduced that the phase-alignment information influenced the contrast-gain control mechanism before the binocular summation stage and that the phase-alignment information and structural misalignment information caused relatively strong divisive inhibition in the monocular and interocular suppression stages. When the pedestals were phase-scrambled, the elimination of the interocular suppression processing was the most convincing explanation of the results. Thus, our results indicated that both phase-alignment information and similar image structures cause strong interocular suppression. Copyright © 2018 Elsevier Ltd. All rights reserved.

Adaptive Fuzzy Robust Control for a Class of Nonlinear Systems via Small Gain Theorem

Directory of Open Access Journals (Sweden)

Xingjian Wang

2013-01-01

Full Text Available Practical nonlinear systems can usually be represented by partly linearizable models with unknown nonlinearities and external disturbances. Based on this consideration, we propose a novel adaptive fuzzy robust control (AFRC algorithm for such systems. The AFRC effectively combines techniques of adaptive control and fuzzy control, and it improves the performance by retaining the advantages of both methods. The linearizable part will be linearly parameterized with unknown but constant parameters, and the discontinuous-projection-based adaptive control law is used to compensate these parts. The Takagi-Sugeno fuzzy logic systems are used to approximate unknown nonlinearities. Robust control law ensures the robustness of closed-loop control system. A systematic design procedure of the AFRC algorithm by combining the backstepping technique and small-gain approach is presented. Then the closed-loop stability is studied by using small gain theorem, and the result indicates that the closed-loop system is semiglobally uniformly ultimately bounded.

Preventing Weight Gain in Women in Rural Communities: A Cluster Randomised Controlled Trial.

Directory of Open Access Journals (Sweden)

Catherine Lombard

2016-01-01

Full Text Available Obesity is reaching epidemic proportions in both developed and developing countries. Even modest weight gain increases the risk for chronic illness, yet evidence-based interventions to prevent weight gain are rare. This trial will determine if a simple low-intensity intervention can prevent weight gain in women compared to general health information.We conducted a 1-yr pragmatic, cluster randomised controlled trial in 41 Australian towns (clusters randomised using a computer-generated randomisation list for intervention (n = 21 or control (n = 20. Women aged 18 to 50 yr were recruited from the general population to receive a 1-yr self-management lifestyle intervention (HeLP-her consisting of one group session, monthly SMS text messages, one phone coaching session, and a program manual, or to a control group receiving one general women's health education session. From October 2012 to April 2014 we studied 649 women, mean age 39.6 yr (+/- SD 6.7 and BMI of 28.8 kg/m(2 (+/- SD 6.9 with the primary outcome weight change between groups at 1 yr. The mean change in the control was +0.44 kg (95% CI -0.09 to 0.97 and in the intervention group -0.48 kg (95% CI -0.99 to 0.03 with an unadjusted between group difference of -0.92 kg (95% CI -1.67 to -0.16 or -0.87 kg (95% CI -1.62 to -0.13 adjusted for baseline values and clustering. Secondary outcomes included improved diet quality and greater self-management behaviours. The intervention appeared to be equally efficacious across all age, BMI, income, and education subgroups. Loss to follow-up included 23.8% in the intervention group and 21.8% in the control group and was within the anticipated range. Limitations include lack of sensitive tools to measure the small changes to energy intake and physical activity. Those who gained weight may have been less inclined to return for 1 yr weight measures.A low intensity lifestyle program can prevent the persistent weight gain observed in women. Key features included

A novel analog/digital reconfigurable automatic gain control with a novel DC offset cancellation circuit

Energy Technology Data Exchange (ETDEWEB)

He Xiaofeng; Ye Tianchun [Institute of Microelectronics, Chinese Academy of Science, Beijing 100029 (China); Mo Taishan; Ma Chengyan, E-mail: hexiaofeng@casic.ac.cn [Hangzhou Zhongke Microelectronics Co, Ltd, Hangzhou 310053 (China)

2011-02-15

An analog/digital reconfigurable automatic gain control (AGC) circuit with a novel DC offset cancellation circuit for a direct-conversion receiver is presented. The AGC is analog/digital reconfigurable in order to be compatible with different baseband chips. What's more, a novel DC offset cancellation (DCOC) circuit with an HPCF (high pass cutoff frequency) less than 10 kHz is proposed. The AGC is fabricated by a 0.18 {mu}m CMOS process. Under analog control mode, the AGC achieves a 70 dB dynamic range with a 3 dB-bandwidth larger than 60 MHz. Under digital control mode, through a 5-bit digital control word, the AGC shows a 64 dB gain control range by 2 dB each step with a gain error of less than 0.3 dB. The DC offset cancellation circuits can suppress the output DC offset voltage to be less than 1.5 mV, while the offset voltage of 40 mV is introduced into the input. The overall power consumption is less than 3.5 mA, and the die area is 800 x 300 {mu}m{sup 2}. (semiconductor integrated circuits)

Application of automatic gain control for radiometer diagnostic in SST-1 tokamak.

Science.gov (United States)

Makwana, Foram R; Siju, Varsha; Edappala, Praveenlal; Pathak, S K

2017-12-01

This paper describes the characterisation of a negative feedback type of automatic gain control (AGC) circuit that will be an integral part of the heterodyne radiometer system operating at a frequency range of 75-86 GHz at SST-1 tokamak. The developed AGC circuit is a combination of variable gain amplifier and log amplifier which provides both gain and attenuation typically up to 15 dB and 45 dB, respectively, at a fixed set point voltage and it has been explored for the first time in tokamak radiometry application. The other important characteristics are that it exhibits a very fast response time of 390 ns to understand the fast dynamics of electron cyclotron emission and can operate at very wide input RF power dynamic range of around 60 dB that ensures signal level within the dynamic range of the detection system.

Automatic gain control of neural coupling during cooperative hand movements.

Science.gov (United States)

Thomas, F A; Dietz, V; Schrafl-Altermatt, M

2018-04-13

Cooperative hand movements (e.g. opening a bottle) are controlled by a task-specific neural coupling, reflected in EMG reflex responses contralateral to the stimulation site. In this study the contralateral reflex responses in forearm extensor muscles to ipsilateral ulnar nerve stimulation was analyzed at various resistance and velocities of cooperative hand movements. The size of contralateral reflex responses was closely related to the level of forearm muscle activation required to accomplish the various cooperative hand movement tasks. This indicates an automatic gain control of neural coupling that allows a rapid matching of corrective forces exerted at both sides of an object with the goal 'two hands one action'.

Vector Control Algorithm for Electric Vehicle AC Induction Motor Based on Improved Variable Gain PID Controller

Directory of Open Access Journals (Sweden)

Gang Qin

2015-01-01

Full Text Available The acceleration performance of EV, which affects a lot of performances of EV such as start-up, overtaking, driving safety, and ride comfort, has become increasingly popular in recent researches. An improved variable gain PID control algorithm to improve the acceleration performance is proposed in this paper. The results of simulation with Matlab/Simulink demonstrate the effectiveness of the proposed algorithm through the control performance of motor velocity, motor torque, and three-phase current of motor. Moreover, it is investigated that the proposed controller is valid by comparison with the other PID controllers. Furthermore, the AC induction motor experiment set is constructed to verify the effect of proposed controller.

Sliding mode controller gain adaptation and chattering reduction techniques for DSP-based PM DC motor drives

DEFF Research Database (Denmark)

Dal, Mehmet; Teodorescu, Remus

2011-01-01

In order to achieve and maintain the prospective benefits of sliding mode control (SMC) methodology, the phenomenon known as “chattering”, the main obstacle encountered in real-time applications, has to be suppressed. In this study, two promising switching control gain adaptation and chattering...... reduction techniques are investigated, and the effectiveness of chattering suppression for current regulation of PM DC drives is tested. The sampling rate was also examined to determine how it affects the amplitude of chattering. This paper concentrates on various combinations of observer-based methods...... in order to find the best solution for chattering reduction. To find a practical solution a tunable low-pass filter (LPF) was used to average the discontinuous control term. The validity of the existing conditions for the gain adaptation methods are examined and observer gain value was determined through...

A Technology-Mediated Behavioral Weight Gain Prevention Intervention for College Students: Controlled, Quasi-Experimental Study.

Science.gov (United States)

West, Delia Smith; Monroe, Courtney M; Turner-McGrievy, Gabrielle; Sundstrom, Beth; Larsen, Chelsea; Magradey, Karen; Wilcox, Sara; Brandt, Heather M

2016-06-13

Both men and women are vulnerable to weight gain during the college years, and this phenomenon is linked to an increased risk of several chronic diseases and mortality. Technology represents an attractive medium for the delivery of weight control interventions focused on college students, given its reach and appeal among this population. However, few technology-mediated weight gain prevention interventions have been evaluated for college students. This study examined a new technology-based, social media-facilitated weight gain prevention intervention for college students. Undergraduates (n =58) in two sections of a public university course were allocated to either a behavioral weight gain prevention intervention (Healthy Weight, HW; N=29) or a human papillomavirus (HPV) vaccination awareness intervention (control; N=29). All students were enrolled, regardless of initial body weight or expressed interest in weight management. The interventions delivered 8 lessons via electronic newsletters and Facebook postings over 9 weeks, which were designed to foster social support and introduce relevant educational content. The HW intervention targeted behavioral strategies to prevent weight gain and provided participants with a Wi-Fi-enabled scale and an electronic physical activity tracker to facilitate weight regulation. A repeated-measures analysis of variance was conducted to examine within- and between-group differences in measures of self-reported weight control practices and objectively measured weight. Use of each intervention medium and device was objectively tracked, and intervention satisfaction measures were obtained. Students remained weight stable (HW: -0.48+1.9 kg; control: -0.45+1.4 kg), with no significant difference between groups over 9 weeks (P =.94). However, HW students reported a significantly greater increase in the number of appropriate weight control strategies than did controls (2.1+4.5 vs -1.1+3.4, respectively; P =.003) and there was no increase in

Interaural Level Difference Dependent Gain Control and Synaptic Scaling Underlying Binaural Computation

Science.gov (United States)

Xiong, Xiaorui R.; Liang, Feixue; Li, Haifu; Mesik, Lukas; Zhang, Ke K.; Polley, Daniel B.; Tao, Huizhong W.; Xiao, Zhongju; Zhang, Li I.

2013-01-01

Binaural integration in the central nucleus of inferior colliculus (ICC) plays a critical role in sound localization. However, its arithmetic nature and underlying synaptic mechanisms remain unclear. Here, we showed in mouse ICC neurons that the contralateral dominance is created by a “push-pull”-like mechanism, with contralaterally dominant excitation and more bilaterally balanced inhibition. Importantly, binaural spiking response is generated apparently from an ipsilaterally-mediated scaling of contralateral response, leaving frequency tuning unchanged. This scaling effect is attributed to a divisive attenuation of contralaterally-evoked synaptic excitation onto ICC neurons with their inhibition largely unaffected. Thus, a gain control mediates the linear transformation from monaural to binaural spike responses. The gain value is modulated by interaural level difference (ILD) primarily through scaling excitation to different levels. The ILD-dependent synaptic scaling and gain adjustment allow ICC neurons to dynamically encode interaural sound localization cues while maintaining an invariant representation of other independent sound attributes. PMID:23972599

LPV gain-scheduled control of SCR aftertreatment systems

Science.gov (United States)

Meisami-Azad, Mona; Mohammadpour, Javad; Grigoriadis, Karolos M.; Harold, Michael P.; Franchek, Matthew A.

2012-01-01

Hydrocarbons, carbon monoxide and some of other polluting emissions produced by diesel engines are usually lower than those produced by gasoline engines. While great strides have been made in the exhaust aftertreatment of vehicular pollutants, the elimination of nitrogen oxide (NO x ) from diesel vehicles is still a challenge. The primary reason is that diesel combustion is a fuel-lean process, and hence there is significant unreacted oxygen in the exhaust. Selective catalytic reduction (SCR) is a well-developed technology for power plants and has been recently employed for reducing NO x emissions from automotive sources and in particular, heavy-duty diesel engines. In this article, we develop a linear parameter-varying (LPV) feedforward/feedback control design method for the SCR aftertreatment system to decrease NO x emissions while keeping ammonia slippage to a desired low level downstream the catalyst. The performance of the closed-loop system obtained from the interconnection of the SCR system and the output feedback LPV control strategy is then compared with other control design methods including sliding mode, and observer-based static state-feedback parameter-varying control. To reduce the computational complexity involved in the control design process, the number of LPV parameters in the developed quasi-LPV (qLPV) model is reduced by applying the principal component analysis technique. An LPV feedback/feedforward controller is then designed for the qLPV model with reduced number of scheduling parameters. The designed full-order controller is further simplified to a first-order transfer function with a parameter-varying gain and pole. Finally, simulation results using both a low-order model and a high-fidelity and high-order model of SCR reactions in GT-POWER interfaced with MATLAB/SIMULINK illustrate the high NO x conversion efficiency of the closed-loop SCR system using the proposed parameter-varying control law.

Gain scheduling using the Youla parameterization

DEFF Research Database (Denmark)

Niemann, Hans Henrik; Stoustrup, Jakob

1999-01-01

Gain scheduling controllers are considered in this paper. The gain scheduling problem where the scheduling parameter vector cannot be measured directly, but needs to be estimated is considered. An estimation of the scheduling vector has been derived by using the Youla parameterization. The use...... in connection with H_inf gain scheduling controllers....

Europe’s Dependence on Russian Natural Gas: Perspectives and Recommendations for a Long-Term Strategy

Science.gov (United States)

2008-09-01

Ukraine, Poland, and the  Slovak  republic. 64 As part of the gas deal  with Belarus, over the next several years, Gazprom will gain 50% of the equity of...reference=IP/08/1099&format=HTML&aged=0& language =EN&guiLanguage=en  (accessed July 14, 2008).]  110  Stephen Boykewich, “St. Petersburg Mining Institute...trillion m 3 (which Gazprom  labels  its  key strategic asset), the Sakhalin Island projects  in the Sea of Okhotsk, estimated at 2.7 trillion  m 3 ,  and

Time-optimal control of nuclear reactor power with adaptive proportional- integral-feedforward gains

International Nuclear Information System (INIS)

Park, Moon Ghu; Cho, Nam Zin

1993-01-01

A time-optimal control method which consists of coarse and fine control stages is described here. During the coarse control stage, the maximum control effort (time-optimal) is used to direct the system toward the switching boundary which is set near the desired power level. At this boundary, the controller is switched to the fine control stage in which an adaptive proportional-integral-feedforward (PIF) controller is used to compensate for any unmodeled reactivity feedback effects. This fine control is also introduced to obtain a constructive method for determining the (adaptive) feedback gains against the sampling effect. The feedforward control term is included to suppress the over-or undershoot. The estimation and feedback of the temperature-induced reactivity is also discussed

Design and evaluation of controls for drift, video gain, and color balance in spaceborne facsimile cameras

Science.gov (United States)

Katzberg, S. J.; Kelly, W. L., IV; Rowland, C. W.; Burcher, E. E.

1973-01-01

The facsimile camera is an optical-mechanical scanning device which has become an attractive candidate as an imaging system for planetary landers and rovers. This paper presents electronic techniques which permit the acquisition and reconstruction of high quality images with this device, even under varying lighting conditions. These techniques include a control for low frequency noise and drift, an automatic gain control, a pulse-duration light modulation scheme, and a relative spectral gain control. Taken together, these techniques allow the reconstruction of radiometrically accurate and properly balanced color images from facsimile camera video data. These techniques have been incorporated into a facsimile camera and reproduction system, and experimental results are presented for each technique and for the complete system.

A temperature-dependent gain control system for improving the stability of Si-PM-based PET systems

International Nuclear Information System (INIS)

Yamamoto, Seiichi; Satomi, Junkichi; Watabe, Tadashi; Imaizumi, Masao; Shimosegawa, Eku; Hatazawa, Jun; Watabe, Hiroshi; Kanai, Yasukazu

2011-01-01

The silicon-photomultiplier (Si-PM) is a promising photodetector for the development of new PET systems due to its small size, high gain and relatively low sensitivity to the static magnetic field. One drawback of the Si-PM is that it has significant temperature-dependent gain that poses a problem for the stability of the Si-PM-based PET system. To reduce this problem, we developed and tested a temperature-dependent gain control system for the Si-PM-based PET system. The system consists of a thermometer, analog-to-digital converter, personal computer, digital-to-analog converter and variable gain amplifiers in the weight summing board of the PET system. Temperature characteristics of the Si-PM array are measured and the calculated correction factor is sent to the variable gain amplifier. Without this correction, the temperature-dependent peak channel shifts of the block detector were -55% from 20 deg. C to 35 deg.C. With the correction, the peak channel variations were corrected within ±8%. The coincidence count rate of the Si-PM-based PET system was measured using a Na-22 point source while monitoring the room temperature. Without the correction, the count rate inversely changed with the room temperature by 10% for 1.5 deg. C temperature changes. With the correction, the count rate variation was reduced to within 3.7%. These results indicate that the developed temperature-dependent gain control system can contribute to improving the stability of Si-PM-based PET systems.

Visual signal detection in structured backgrounds. II. Effects of contrast gain control, background variations, and white noise

Science.gov (United States)

Eckstein, M. P.; Ahumada, A. J. Jr; Watson, A. B.

1997-01-01

Studies of visual detection of a signal superimposed on one of two identical backgrounds show performance degradation when the background has high contrast and is similar in spatial frequency and/or orientation to the signal. To account for this finding, models include a contrast gain control mechanism that pools activity across spatial frequency, orientation and space to inhibit (divisively) the response of the receptor sensitive to the signal. In tasks in which the observer has to detect a known signal added to one of M different backgrounds grounds due to added visual noise, the main sources of degradation are the stochastic noise in the image and the suboptimal visual processing. We investigate how these two sources of degradation (contrast gain control and variations in the background) interact in a task in which the signal is embedded in one of M locations in a complex spatially varying background (structured background). We use backgrounds extracted from patient digital medical images. To isolate effects of the fixed deterministic background (the contrast gain control) from the effects of the background variations, we conduct detection experiments with three different background conditions: (1) uniform background, (2) a repeated sample of structured background, and (3) different samples of structured background. Results show that human visual detection degrades from the uniform background condition to the repeated background condition and degrades even further in the different backgrounds condition. These results suggest that both the contrast gain control mechanism and the background random variations degrade human performance in detection of a signal in a complex, spatially varying background. A filter model and added white noise are used to generate estimates of sampling efficiencies, an equivalent internal noise, an equivalent contrast-gain-control-induced noise, and an equivalent noise due to the variations in the structured background.

Heliostat-field gain-scheduling control applied to a two-step solar hydrogen production plant

International Nuclear Information System (INIS)

Roca, Lidia; Calle, Alberto de la; Yebra, Luis J.

2013-01-01

Highlights: ► A control system is proposed for a solar reactor system which produces hydrogen. ► The controller chooses which heliostats from the solar field must be focused. ► A gain scheduling scheme is included to deal with different system dynamics. ► The scheme is tested and tunned in simulation. ► Real experiments show the promising results of this work. -- Abstract: This article describes a temperature control structure designed for the interior of a solar hydrogen reactor based on a two-step ferrite-redox technology. Until now, this temperature has been controlled by manual selection of the heliostats to be focused on the receiver targets. However, the strong system dependency on operating conditions suggests that the procedure be automated in order to ensure the desired setpoint change response. The aims are to maintain the desired temperatures and to make the setpoint switch as fast as possible, keeping plant conditions within the margins of safety. The scheme proposed includes a procedure for selecting the heliostats to be focused on the reactor by using a simple model of the solar field and a gain scheduling control system which changes the control tuning parameters to deal with the varying dynamics observed during the process. Real experiments show the promising results of this work.

Russian natural gas policy and its possible effects on European gas markets

International Nuclear Information System (INIS)

Quast, O.; Locatelli, C.

1997-01-01

There is a growing perception among Western European gas experts that Russia has developed a considerable gas surplus - the Russian gas bubble. Thus, the question clearly arises how much gas is available for export and how much gas, over the next 15 to 20 years, can the Russian quasi-monopolist Gazprom market in Western Europe. We consider that Gazprom's export strategy mirrors the approach of Russia's natural gas policy towards the Western European market. In this paper, we will focus on the characteristics of Gazprom's export strategy, its underlying logic, and its impact on Western European gas markets. As a consequence of Gazprom's export strategy, the Russian gas company faces today a price quantity dilemma. Gazprom's problem is to place as much gas as possible in the growing Western European gas market, without destroying downstream gas prices. We argue that Gazprom has adopted a market share expansion and downstream vertical integration strategy, aimed at capturing a part of the downstream gas rent. Although this strategy appears to have initiated a form of gas to gas competition in a number of European consumer markets, this strategy is not based on an aggressive price policy. However, in order to live up to its ambitions, there is a chance that Gazprom will have to somewhat relax traditional contract clauses, such as contract length, indexation terms and take or pay conditions. (author)

Voluntary Fasting to Control Post-Ramadan Weight Gain among Overweight and Obese Women

Directory of Open Access Journals (Sweden)

Suriani Ismail

2015-01-01

Full Text Available Objectives: This study aimed to examine the effectiveness of an Islamic voluntary fasting intervention to control post-Ramadan weight gain. Methods: This study was conducted between July and November 2011. Two weight loss intervention programmes were developed and implemented among groups of overweight or obese Malay women living in the Malaysian cities of Putrajaya and Seremban: a standard programme promoting control of food intake according to national dietary guidelines (group B and a faith-based programme promoting voluntary fasting in addition to the standard programme (group A. Participants’ dietary practices (i.e., voluntary fasting practices, frequency of fruit/vegetable consumption per week and quantity of carbohydrates/protein consumed per day, body mass index (BMI, blood pressure, fasting blood high-density lipoprotein cholesterol (HDL-C and total cholesterol (TC:HDL-C ratio were assessed before Ramadan and three months post-Ramadan. Results: Voluntary fasting practices increased only in group A (P <0.01. Additionally, the quantity of protein/carbohydrates consumed per day, mean diastolic pressure and TC:HDL-C ratio decreased only in group A (P <0.01, 0.05, 0.02 and <0.01, respectively. Frequency of fruit/vegetable consumption per week, as well as HDL-C levels, increased only in group A (P = 0.03 and <0.01, respectively. Although changes in BMI between the groups was not significant (P = 0.08, BMI decrease among participants in group A was significant (P <0.01. Conclusion: Control of post-Ramadan weight gain was more evident in the faith-based intervention group. Healthcare providers should consider faith-based interventions to encourage weight loss during Ramadan and to prevent post-Ramadan weight gain among patients.

Voluntary Fasting to Control Post-Ramadan Weight Gain among Overweight and Obese Women

Science.gov (United States)

Ismail, Suriani; Shamsuddin, Khadijah; Latiff, Khalib A.; Saad, Hazizi A.; Majid, Latifah A.; Othman, Fadlan M.

2015-01-01

Objectives: This study aimed to examine the effectiveness of an Islamic voluntary fasting intervention to control post-Ramadan weight gain. Methods: This study was conducted between July and November 2011. Two weight loss intervention programmes were developed and implemented among groups of overweight or obese Malay women living in the Malaysian cities of Putrajaya and Seremban: a standard programme promoting control of food intake according to national dietary guidelines (group B) and a faith-based programme promoting voluntary fasting in addition to the standard programme (group A). Participants’ dietary practices (i.e., voluntary fasting practices, frequency of fruit/vegetable consumption per week and quantity of carbohydrates/protein consumed per day), body mass index (BMI), blood pressure, fasting blood high-density lipoprotein cholesterol (HDL-C) and total cholesterol (TC):HDL-C ratio were assessed before Ramadan and three months post-Ramadan. Results: Voluntary fasting practices increased only in group A (P <0.01). Additionally, the quantity of protein/carbohydrates consumed per day, mean diastolic pressure and TC:HDL-C ratio decreased only in group A (P <0.01, 0.05, 0.02 and <0.01, respectively). Frequency of fruit/vegetable consumption per week, as well as HDL-C levels, increased only in group A (P = 0.03 and <0.01, respectively). Although changes in BMI between the groups was not significant (P = 0.08), BMI decrease among participants in group A was significant (P <0.01). Conclusion: Control of post-Ramadan weight gain was more evident in the faith-based intervention group. Healthcare providers should consider faith-based interventions to encourage weight loss during Ramadan and to prevent post-Ramadan weight gain among patients. PMID:25685394

Gestational weight gain.

Science.gov (United States)

Kominiarek, Michelle A; Peaceman, Alan M

2017-12-01

Prenatal care providers are advised to evaluate maternal weight at each regularly scheduled prenatal visit, monitor progress toward meeting weight gain goals, and provide individualized counseling if significant deviations from a woman's goals occur. Today, nearly 50% of women exceed their weight gain goals with overweight and obese women having the highest prevalence of excessive weight gain. Risks of inadequate weight gain include low birthweight and failure to initiate breast-feeding whereas the risks of excessive weight gain include cesarean deliveries and postpartum weight retention for the mother and large-for-gestational-age infants, macrosomia, and childhood overweight or obesity for the offspring. Prenatal care providers have many resources and tools to incorporate weight and other health behavior counseling into routine prenatal practices. Because many women are motivated to improve health behaviors, pregnancy is often considered the optimal time to intervene for issues related to eating habits and physical activity to prevent excessive weight gain. Gestational weight gain is a potentially modifiable risk factor for a number of adverse maternal and neonatal outcomes and meta-analyses of randomized controlled trials report that diet or exercise interventions during pregnancy can help reduce excessive weight gain. However, health behavior interventions for gestational weight gain have not significantly improved other maternal and neonatal outcomes and have limited effectiveness in overweight and obese women. Copyright © 2017 Elsevier Inc. All rights reserved.

New results on the robust stability of PID controllers with gain and phase margins for UFOPTD processes.

Science.gov (United States)

Jin, Q B; Liu, Q; Huang, B

2016-03-01

This paper considers the problem of determining all the robust PID (proportional-integral-derivative) controllers in terms of the gain and phase margins (GPM) for open-loop unstable first order plus time delay (UFOPTD) processes. It is the first time that the feasible ranges of the GPM specifications provided by a PID controller are given for UFOPTD processes. A gain and phase margin tester is used to modify the original model, and the ranges of the margin specifications are derived such that the modified model can be stabilized by a stabilizing PID controller based on Hermite-Biehlers Theorem. Furthermore, we obtain all the controllers satisfying a given margin specification. Simulation studies show how to use the results to design a robust PID controller. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Dynamic Sliding Mode Evolution PWM Controller for a Novel High-Gain Interleaved DC-DC Converter in PV System

Directory of Open Access Journals (Sweden)

Taizhou Bei

2014-01-01

Full Text Available Considering the disadvantages of the traditional high-gain DC-DC converter such as big size, high voltage stress of switches, and large input current ripple, a novel high-gain interleaved boost converter with coupled-inductor and switched-capacitor was proposed correspondingly and the operation principle together with the steady-state analysis of this converter was also described. Besides, a new control approach-dynamic sliding mode evolution PWM controller (DSME PWM for the novel topological converter based on both dynamic evolution and sliding mode control was also presented. From the simulation results and experimental validation the proposed converter can fulfill high-gain boost, low ripple of both the input current and the output voltage. Furthermore, MPPT technique can be also achieved in a short time by simulation. The efficiency and stability of the converter proposed in this paper can be improved.

A novel heart rate control model provides insights linking LF-HRV behavior to the open-loop gain.

Science.gov (United States)

Dvir, Hila; Bobrovsky, Ben Zion; Gabbay, Uri

2013-09-20

Low-frequency heart rate variability (LF-HRV) at rest has already been successfully modeled as self-sustained oscillations in a nonlinear control loop, but these models fail to simulate LF-HRV decreases either during aerobic exercise or in heart failure patients. Following control engineering practices, we assume the existence of a biological excitation (dither) within the heart rate control loop that softens the nonlinearity and studied LF-HRV behavior in a dither-embedded model. We adopted the Ottesen model with some revisions and induced a dither of high-frequency stochastic perturbations. We simulated scenarios of a healthy subject at rest and during aerobic exercise (by decreasing peripheral vascular resistance) and a heart failure patient (by decreasing stroke volume). The simulations resembled physiological LF-HRV behavior, i.e., LF-HRV decreased during aerobic exercise and in the heart failure patient. The simulations exhibited LF-HRV dependency on the open-loop gain, which is related to the product of the feedback gain and the feed forward gain. We are the first to demonstrate that LF-HRV may be dependent on the open-loop gain. Accordingly, reduced open-loop gain results in decreased LF-HRV, and vice versa. Our findings explain a well-known but unexplained observed phenomenon of reduced LF-HRV both in heart failure patients and in healthy subjects performing aerobic exercise. These findings have implications on how changes in LF-HRV can be interpreted physiologically, a necessary step towards the clinical utilization of LF-HRV. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Application of particle swarm optimization in gas turbine engine fuel controller gain tuning

Science.gov (United States)

Montazeri-Gh, M.; Jafari, S.; Ilkhani, M. R.

2012-02-01

This article presents the application of particle swarm optimization (PSO) for gain tuning of the gas turbine engine (GTE) fuel controller. For this purpose, the structure of a fuel controller is firstly designed based on the GTE control requirements and constraints. The controller gains are then tuned by PSO where the tuning process is formulated as an engineering optimization problem. In this study, the response time during engine acceleration and deceleration as well as the engine fuel consumption are considered as the objective functions. A computer simulation is also developed to evaluate the objective values for a single spool GTE. The GTE model employed for the simulation is a Wiener model, the parameters of which are extracted from experimental tests. In addition, the effect of neighbour acceleration on PSO results is studied. The results show that the neighbour acceleration factor has a considerable effect on the convergence rate of the PSO process. The PSO results are also compared with the results obtained through a genetic algorithm (GA) to show the relative merits of PSO. Moreover, the PSO results are compared with the results obtained from the dynamic programming (DP) method in order to illustrate the ability of proposed method in finding the global optimal solution. Furthermore, the objective function is also defined in multi-objective manner and the multi-objective particle swarm optimization (MOPSO) is applied to find the Pareto-front for the problem. Finally, the results obtained from the simulation of the optimized controller confirm the effectiveness of the proposed approach to design an optimal fuel controller resulting in an improved GTE performance as well as protection against the physical limitations.

Today or not today: Deregulating the Russian gas sector

International Nuclear Information System (INIS)

Grigoryev, Yuli

2007-01-01

Although Russia is the world's biggest producer of natural gas, its ability to maintain timely and reliable supply to meet the growing global demand has come under question in recent months. The gas war with Ukraine notwithstanding, concern has been raised by a number of observers that underinvestment in the gas sector will lead to a systemic failure of the state monopolist OAO Gazprom to increase or even maintain current levels of production. Yet with a quarter of European gas coming from Russia, and with increasing presence of Gazprom in European downstream operations (such as Germany, Hungary, and other CIS states) as well as seemingly closer ties with Algeria, another major supplier of gas to Europe, there has been a strong reaction from Europe's policy-makers to decrease dependence on Russian gas. Deregulating and liberalising the gas sector would see the lifting of restrictions to foreign or independent investors wishing to gain access to Russian reserves, as well as the unhindered access to the pipeline infrastructure and export markets. It would also signal the unbundling of Gazprom and an end to the artificially low price of gas to the domestic consumer. This paper discusses whether deregulation is the optimal way to raise capital, attract investment and increase supply security for Russia's Western neighbours. In doing so, the paper identifies the objectives of the EU as the importer whilst trying to align them with the objectives of the Russian Federation as the exporter, in the current political context

Frequency domain design of gain scheduling control for large wind systems in full-load region

International Nuclear Information System (INIS)

Burlibaşa, A.; Ceangă, E.

2014-01-01

Highlights: • A large wind energy system, operating under full-load regime, is considered. • According to its particularities in frequency domain, control law design is provided. • These particularities are influenced by the interactions of wind–tower–blade ensemble. • Control low, within gain scheduling strategy, is achieved imposing stability reserve. • Supplementary a criterion, aimed at reducing mechanical loads, is imposed. - Abstract: The paper presents the issue of power control law synthesis, in the case of a large wind system that operates under full-load regime, based on dynamic properties details in frequency domain. Solving this problem involves two phases: the establishment of a linearized model as faithfully as possible in various operating points of the full-load region, and synthesis of the power controller, considered with classic structure, taking into account frequency particularities of the obtained linearized model. Obtained linear model of the controlled process is of order 16 and encloses subsystems for tower fore-aft oscillations damping, and for drive-train torsion oscillations damping. The designed controller contains a PI component and a lag compensator for dynamic correction at high frequencies. It is known that the main features of wind system dynamics generated by the interaction of wind–tower–blade ensemble cause a gap in the gain characteristic of the model and complex conjugate zeros, which can move between right and left half-planes, depending on the average wind speed value. Consequently, for control law synthesis an interactive frequency solution is adopted. This is “transparent” in relation to particularities induced by wind–tower–blade interaction. This solution allows evaluation of the extent to which control law is affected by the subsystem for tower oscillations damping. Given the strong dependence between the model and the mean wind speed value, a gain scheduling control law is designed. At

Gain transient control for wavelength division multiplexed access networks using semiconductor optical amplifiers

DEFF Research Database (Denmark)

Gibbon, Timothy Braidwood; Osadchiy, Alexey Vladimirovich; Kjær, Rasmus

2009-01-01

Gain transients can severely hamper the upstream network performance in wavelength division multiplexed (WDM) access networks featuring erbium doped fiber amplifiers (EDFAs) or Raman amplification. We experimentally demonstrate for the first time using 10 Gb/s fiber transmission bit error rate...... measurements how a near-saturated semiconductor optical amplifier (SOA) can be used to control these gain transients. An SOA is shown to reduce the penalty of transients originating in an EDFA from 2.3 dB to 0.2 dB for 10 Gb/s transmission over standard single mode fiber using a 231-1 PRBS pattern. The results...... suggest that a single SOA integrated within a WDM receiver at the metro node could offer a convenient all-optical solution for upstream transient controlin WDM access networks....

Effects of gain-scheduling methods in a classical wind turbine controller on wind turbine aeroservoelastic modes and loads

DEFF Research Database (Denmark)

Tibaldi, Carlo; Henriksen, Lars Christian; Hansen, Morten Hartvig

2014-01-01

The eects of dierent gain-scheduling methods for a classical wind turbine controller, operating in full load region, on the wind turbine aeroservoelastic modes and loads are investigated in this work. The dierent techniques are derived looking at the physical problem to take into account the chan......The eects of dierent gain-scheduling methods for a classical wind turbine controller, operating in full load region, on the wind turbine aeroservoelastic modes and loads are investigated in this work. The dierent techniques are derived looking at the physical problem to take into account...

Gain-scheduled {{\\mathscr{H}}}_{\\infty } buckling control of a circular beam-column subject to time-varying axial loads

Science.gov (United States)

Schaeffner, Maximilian; Platz, Roland

2018-06-01

For slender beam-columns loaded by axial compressive forces, active buckling control provides a possibility to increase the maximum bearable axial load above that of a purely passive structure. In this paper, an approach for gain-scheduled {{\\mathscr{H}}}∞ buckling control of a slender beam-column with circular cross-section subject to time-varying axial loads is investigated experimentally. Piezo-elastic supports with integrated piezoelectric stack actuators at the beam-column ends allow an active stabilization in arbitrary lateral directions. The axial loads on the beam-column influence its lateral dynamic behavior and, eventually, cause the beam-column to buckle. A reduced modal model of the beam-column subject to axial loads including the dynamics of the electrical components is set up and calibrated with experimental data. Particularly, the linear parameter-varying open-loop plant is used to design a model-based gain-scheduled {{\\mathscr{H}}}∞ buckling control that is implemented in an experimental test setup. The beam-column is loaded by ramp- and step-shaped time-varying axial compressive loads that result in a lateral deformation of the beam-column due to imperfections, such as predeformation, eccentric loading or clamping moments. The lateral deformations and the maximum bearable loads of the beam-column are analyzed and compared for the beam-column with and without gain-scheduled {{\\mathscr{H}}}∞ buckling control or, respectively, active and passive configuration. With the proposed gain-scheduled {{\\mathscr{H}}}∞ buckling control it is possible to increase the maximum bearable load of the active beam-column by 19% for ramp-shaped axial loads and to significantly reduce the beam-column deformations for step-shaped axial loads compared to the passive structure.

Analysis of Non-Uniform Gain for Control of a Deformable Mirror in an Adaptive-Optics System

National Research Council Canada - National Science Library

Vitayaudom, Kevin P

2008-01-01

The objective of this research was to develop and experimentally verify the use of spatially varying gain maps on the servo-loop controller of a deformable mirror for improvements in the performance...

The inhibitory microcircuit of the substantia nigra provides feedback gain control of the basal ganglia output.

Science.gov (United States)

Brown, Jennifer; Pan, Wei-Xing; Dudman, Joshua Tate

2014-05-21

Dysfunction of the basal ganglia produces severe deficits in the timing, initiation, and vigor of movement. These diverse impairments suggest a control system gone awry. In engineered systems, feedback is critical for control. By contrast, models of the basal ganglia highlight feedforward circuitry and ignore intrinsic feedback circuits. In this study, we show that feedback via axon collaterals of substantia nigra projection neurons control the gain of the basal ganglia output. Through a combination of physiology, optogenetics, anatomy, and circuit mapping, we elaborate a general circuit mechanism for gain control in a microcircuit lacking interneurons. Our data suggest that diverse tonic firing rates, weak unitary connections and a spatially diffuse collateral circuit with distinct topography and kinetics from feedforward input is sufficient to implement divisive feedback inhibition. The importance of feedback for engineered systems implies that the intranigral microcircuit, despite its absence from canonical models, could be essential to basal ganglia function. DOI: http://dx.doi.org/10.7554/eLife.02397.001. Copyright © 2014, Brown et al.

Reason's Enemy Is Not Emotion: Engagement of Cognitive Control Networks Explains Biases in Gain/Loss Framing

Science.gov (United States)

2017-01-01

In the classic gain/loss framing effect, describing a gamble as a potential gain or loss biases people to make risk-averse or risk-seeking decisions, respectively. The canonical explanation for this effect is that frames differentially modulate emotional processes, which in turn leads to irrational choice behavior. Here, we evaluate the source of framing biases by integrating functional magnetic resonance imaging data from 143 human participants performing a gain/loss framing task with meta-analytic data from >8000 neuroimaging studies. We found that activation during choices consistent with the framing effect were most correlated with activation associated with the resting or default brain, while activation during choices inconsistent with the framing effect was most correlated with the task-engaged brain. Our findings argue against the common interpretation of gain/loss framing as a competition between emotion and control. Instead, our study indicates that this effect results from differential cognitive engagement across decision frames. SIGNIFICANCE STATEMENT The biases frequently exhibited by human decision makers have often been attributed to the presence of emotion. Using a large fMRI sample and analysis of whole-brain networks defined with the meta-analytic tool Neurosynth, we find that neural activity during frame-biased decisions was more significantly associated with default behaviors (and the absence of executive control) than with emotion. These findings point to a role for neuroscience in shaping long-standing psychological theories in decision science. PMID:28264981

Reason's Enemy Is Not Emotion: Engagement of Cognitive Control Networks Explains Biases in Gain/Loss Framing.

Science.gov (United States)

Li, Rosa; Smith, David V; Clithero, John A; Venkatraman, Vinod; Carter, R McKell; Huettel, Scott A

2017-03-29

In the classic gain/loss framing effect, describing a gamble as a potential gain or loss biases people to make risk-averse or risk-seeking decisions, respectively. The canonical explanation for this effect is that frames differentially modulate emotional processes, which in turn leads to irrational choice behavior. Here, we evaluate the source of framing biases by integrating functional magnetic resonance imaging data from 143 human participants performing a gain/loss framing task with meta-analytic data from >8000 neuroimaging studies. We found that activation during choices consistent with the framing effect were most correlated with activation associated with the resting or default brain, while activation during choices inconsistent with the framing effect was most correlated with the task-engaged brain. Our findings argue against the common interpretation of gain/loss framing as a competition between emotion and control. Instead, our study indicates that this effect results from differential cognitive engagement across decision frames. SIGNIFICANCE STATEMENT The biases frequently exhibited by human decision makers have often been attributed to the presence of emotion. Using a large fMRI sample and analysis of whole-brain networks defined with the meta-analytic tool Neurosynth, we find that neural activity during frame-biased decisions was more significantly associated with default behaviors (and the absence of executive control) than with emotion. These findings point to a role for neuroscience in shaping long-standing psychological theories in decision science. Copyright © 2017 the authors 0270-6474/17/373588-11$15.00/0.

Robust control for spacecraft rendezvous system with actuator unsymmetrical saturation: a gain scheduling approach

Science.gov (United States)

Wang, Qian; Xue, Anke

2018-06-01

This paper has proposed a robust control for the spacecraft rendezvous system by considering the parameter uncertainties and actuator unsymmetrical saturation based on the discrete gain scheduling approach. By changing of variables, we transform the actuator unsymmetrical saturation control problem into a symmetrical one. The main advantage of the proposed method is improving the dynamic performance of the closed-loop system with a region of attraction as large as possible. By the Lyapunov approach and the scheduling technology, the existence conditions for the admissible controller are formulated in the form of linear matrix inequalities. The numerical simulation illustrates the effectiveness of the proposed method.

Adjustment of Adaptive Gain with Bounded Linear Stability Analysis to Improve Time-Delay Margin for Metrics-Driven Adaptive Control

Science.gov (United States)

Bakhtiari-Nejad, Maryam; Nguyen, Nhan T.; Krishnakumar, Kalmanje Srinvas

2009-01-01

This paper presents the application of Bounded Linear Stability Analysis (BLSA) method for metrics driven adaptive control. The bounded linear stability analysis method is used for analyzing stability of adaptive control models, without linearizing the adaptive laws. Metrics-driven adaptive control introduces a notion that adaptation should be driven by some stability metrics to achieve robustness. By the application of bounded linear stability analysis method the adaptive gain is adjusted during the adaptation in order to meet certain phase margin requirements. Analysis of metrics-driven adaptive control is evaluated for a linear damaged twin-engine generic transport model of aircraft. The analysis shows that the system with the adjusted adaptive gain becomes more robust to unmodeled dynamics or time delay.

Non-severe hypoglycaemia is associated with weight gain in patients with type 1 diabetes: Results from the Diabetes Control and Complication Trial.

Science.gov (United States)

Bumbu, Anisoara; Moutairou, Abdul; Matar, Odette; Fumeron, Frédéric; Velho, Gilberto; Riveline, Jean-Pierre; Gautier, Jean-François; Marre, Michel; Roussel, Ronan; Potier, Louis

2018-05-01

It is unclear whether the frequent non-severe episodes of hypoglycaemia observed during intensive glucose control in individuals with type 1 diabetes (T1D) are associated with subsequent weight gain. We analysed the association between non-severe hypoglycaemia and weight gain in 1441 Diabetes Control and Complication Trial (DCCT) participants. Non-severe hypoglycaemia was assessed by hypo-score (ie, number of blood glucose values gain. The annual weight gain by hypo-score tertiles was 0.8 ± 1.2 (T1), 1.3 ± 1.5 (T2) and 1.4 ± 1.3 kg/y (T3), P gain of 1.8 kg/y was 2.14 (95% CI, 1.56-2.93) for T2, and 2.53 (95%CI, 1.85-3.45) for T3 vs T1. These differences in weight gain and in risk of weight gain remained significant after adjustment for sex, age, duration of diabetes, HbA1c at baseline and treatment arms. In conclusion, our analysis shows a significant association between non-severe hypoglycaemia and weight gain in individuals with T1D from the DCCT. © 2017 John Wiley & Sons Ltd.

Almost output regulation of LFT systems via gain-scheduling control

Science.gov (United States)

Yuan, Chengzhi; Duan, Chang; Wu, Fen

2018-05-01

Output regulation of general uncertain systems is a meaningful yet challenging problem. In spite of the rich literature in the field, the problem has not yet been addressed adequately due to the lack of an effective design mechanism. In this paper, we propose a new design framework for almost output regulation of uncertain systems described in the general form of linear fractional transformation (LFT) with time-varying parametric uncertainties and unknown external perturbations. A novel semi-LFT gain-scheduling output regulator structure is proposed, such that the associated control synthesis conditions guaranteeing both output regulation and ? disturbance attenuation performance are formulated as a set of linear matrix inequalities (LMIs) plus parameter-dependent linear matrix equations, which can be solved separately. A numerical example has been used to demonstrate the effectiveness of the proposed approach.

Optimizing Gestational Weight Gain With the Eating4Two Smartphone App: Protocol for a Randomized Controlled Trial.

Science.gov (United States)

Davis, Deborah; Davey, Rachel; Williams, Lauren T; Foureur, Maralyn; Nohr, Ellen; Knight-Agarwal, Catherine; Lawlis, Tanya; Oats, Jeremy; Skouteris, Helen; Fuller-Tyszkiewicz, Matthew

2018-05-30

Approximately 50% of women gain excessive weight in pregnancy. Optimizing gestational weight gain is important for the short- and long-term health of the childbearing woman and her baby. Despite this, there is no recommendation for routine weighing in pregnancy, and weight is a topic that many maternity care providers avoid. Resource-intensive interventions have mainly targeted overweight and obese women with variable results. Few studies have examined the way that socioeconomic status might influence the effectiveness or acceptability of an intervention to participants. Given the scale of the problem of maternal weight gain, maternity services will be unlikely to sustain resource intensive interventions; therefore, innovative strategies are required to assist women to manage weight gain in pregnancy. The primary aim of the trial was to examine the effectiveness of the Eating4Two smartphone app in assisting women of all body mass index categories to optimize gestational weight gain. Secondary aims include comparing childbirth outcomes and satisfaction with antenatal care and examining the way that relative advantage and disadvantage might influence engagement with and acceptability of the intervention. This randomized controlled trial will randomize 1330 women to control or intervention groups in 3 regions of different socioeconomic status. Women will be recruited from clinical and social media sites. The intervention group will be provided with access to the Eating4Two mobile phone app which provides nutrition and dietary information specifically tailored for pregnancy, advice on food serving sizes, and a graph that illustrates women's weight change in relation to the range recommended by the Institute of Medicine. Women will be encouraged to use the app to prompt conversations with their maternity care providers about weight gain in pregnancy. The control group will receive routine antenatal care. Recruitment has commenced though the recruitment rate is slower

Control of Growth Efficiency in Young Plantation Loblolly Pine and Sweetgum through Irrigation and Fertigation Enhancement of Leaf Carbon Gain; FINAL

International Nuclear Information System (INIS)

L. Samuelson

1999-01-01

The overall objective of this study was to determine if growth efficiency of young plantation loblolly pine and sweetgum can be maintained by intensive forest management and whether increased carbon gain is the mechanism controlling growth efficiency response to resource augmentation. Key leaf physiological processes were examined over two growing seasons in response to irrigation, fertigation (irrigation with a fertilizer solution), and fertigation plus pest control (pine only). Although irrigation improved leaf net photosynthesis in pine and decreased stomatal sensitivity to vapor pressure deficit in sweetgum, no consistent physiological responses to fertigation were detected in either species. After 4 years of treatment, a 3-fold increase in woody net primary productivity was observed in both species in response to fertigation. Trees supplemented with fertigation and fertigation plus pest control exhibited the largest increases in growth and biomass. Furthermore, growth efficiency was maintained by fertigation and fertigation plus pest control, despite large increases in crown development and self-shading. Greater growth in response to intensive culture was facilitated by significant gains in leaf mass and whole tree carbon gain rather than detectable increases in leaf level processes. Growth efficiency was not maintained by significant increases in leaf level carbon gain but was possibly influenced by changes in carbon allocation to root versus shoot processes

Gaasisõja teine vaatus Valgevenes / Heiki Suurkask

Index Scriptorium Estoniae

Suurkask, Heiki, 1972-

2006-01-01

Valgevene ja Gazprom pole jõudnud kokkuleppele Valgevenele tarnitava maagaasi hinna tõusus. Gazprom ähvardab järsult vähendada Valgevenesse tarnitava maagaasi kogust, Valgevene ähvardab tõsta maagaasi transiiditasu. Lisa: Kaukaasia valmistub samuti külmaks talveks

Determinants of rapid weight gain during infancy: baseline results from the NOURISH randomised controlled trial

Directory of Open Access Journals (Sweden)

Mihrshahi Seema

2011-11-01

Full Text Available Abstract Background Rapid weight gain in infancy is an important predictor of obesity in later childhood. Our aim was to determine which modifiable variables are associated with rapid weight gain in early life. Methods Subjects were healthy infants enrolled in NOURISH, a randomised, controlled trial evaluating an intervention to promote positive early feeding practices. This analysis used the birth and baseline data for NOURISH. Birthweight was collected from hospital records and infants were also weighed at baseline assessment when they were aged 4-7 months and before randomisation. Infant feeding practices and demographic variables were collected from the mother using a self administered questionnaire. Rapid weight gain was defined as an increase in weight-for-age Z-score (using WHO standards above 0.67 SD from birth to baseline assessment, which is interpreted clinically as crossing centile lines on a growth chart. Variables associated with rapid weight gain were evaluated using a multivariable logistic regression model. Results Complete data were available for 612 infants (88% of the total sample recruited with a mean (SD age of 4.3 (1.0 months at baseline assessment. After adjusting for mother's age, smoking in pregnancy, BMI, and education and infant birthweight, age, gender and introduction of solid foods, the only two modifiable factors associated with rapid weight gain to attain statistical significance were formula feeding [OR = 1.72 (95%CI 1.01-2.94, P = 0.047] and feeding on schedule [OR = 2.29 (95%CI 1.14-4.61, P = 0.020]. Male gender and lower birthweight were non-modifiable factors associated with rapid weight gain. Conclusions This analysis supports the contention that there is an association between formula feeding, feeding to schedule and weight gain in the first months of life. Mechanisms may include the actual content of formula milk (e.g. higher protein intake or differences in feeding styles, such as feeding to schedule

Analysis of sensorless control of brushless DC motor using unknown input observer with different gains

Science.gov (United States)

Astik, Mitesh B.; Bhatt, Praghnesh; Bhalja, Bhavesh R.

2017-03-01

A sensorless control scheme based on an unknown input observer is presented in this paper in which back EMF of the Brushless DC Motor (BLDC) is continuously estimated from available line voltages and currents. During negative rotation of motor, actual and estimated speed fail to track the reference speed and if the corrective action is not taken by the observer, the motor goes into saturation. To overcome this problem, the speed estimation algorithm has been implemented in this paper to control the dynamic behavior of the motor during negative rotation. The Ackermans method was used to calculate the gains of an unknown input observer which is based on the appropriate choice of the eigenvalues in advance. The criteria to choose eigenvalue is to obtain a balance between faster convergence rate and the least noise level. Simulations have been carried out for different disturbances such as step changes in motor reference speed and load torque. The comparative simulation results clearly depict that the disturbance effects in actual and estimated responses minimizes as observer gain setting increases.

Fuzzy-Logic-Based Gain-Scheduling Control for State-of-Charge Balance of Distributed Energy Storage Systems for DC Microgrids

DEFF Research Database (Denmark)

Aldana, Nelson Leonardo Diaz; Dragicevic, Tomislav; Vasquez, Juan Carlos

2014-01-01

-charge or deep-discharge in one of the energy storage units. Primary control in a microgrid is responsible for power sharing among units; and droop control is typically used in this stage. This paper proposes a modular and decentralized gain-scheduling control strategy based on fuzzy logic that ensures balanced...

Weight gain is associated with improved glycaemic control but with adverse changes in plasma lipids and blood pressure isn Type 1 diabetes.

LENUS (Irish Health Repository)

Ferriss, J B

2012-02-03

AIMS: To assess the effects of weight gain on metabolic control, plasma lipids and blood pressure in patients with Type 1 diabetes. METHODS: Patients in the EURODIAB Prospective Complications Study (n = 3250) were examined at baseline and 1800 (55%) were re-examined a mean of 7.3 years later. Patients had Type 1 diabetes, defined as a diagnosis made before age 36 years and with a need for continuous insulin therapy within a year of diagnosis. Patients were aged 15-60 years at baseline and were stratified for age, sex and duration of diabetes. RESULTS: The change in HbA(1c) from baseline to follow-up examination was significantly more favourable in those who gained 5 kg or more during follow-up (\\'marked weight gain\\') than in patients who gained less or no weight or lost weight (\\'less or no weight gain\\'). In those with marked weight gain, there was a significantly greater rise in plasma triglycerides and total cholesterol and significantly less favourable changes in low-density lipoprotein and high-density lipoprotein cholesterol compared with those with less or no weight gain, with or without adjustment for HbA(1c). Systolic and diastolic blood pressure also rose significantly more in the group with marked weight gain. CONCLUSION: Weight gain in patients with Type 1 diabetes has adverse effects on plasma lipids and blood pressure, despite a small improvement in glycaemic control.

High signal-to-noise ratio sensing with Shack–Hartmann wavefront sensor based on auto gain control of electron multiplying CCD

International Nuclear Information System (INIS)

Zhu Zhao-Yi; Li Da-Yu; Hu Li-Fa; Mu Quan-Quan; Yang Cheng-Liang; Cao Zhao-Liang; Xuan Li

2016-01-01

High signal-to-noise ratio can be achieved with the electron multiplying charge-coupled-device (EMCCD) applied in the Shack–Hartmann wavefront sensor (S–H WFS) in adaptive optics (AO). However, when the brightness of the target changes in a large scale, the fixed electron multiplying (EM) gain will not be suited to the sensing limitation. Therefore an auto-gain-control method based on the brightness of light-spots array in S–H WFS is proposed in this paper. The control value is the average of the maximum signals of every light spot in an array, which has been demonstrated to be kept stable even under the influence of some noise and turbulence, and sensitive enough to the change of target brightness. A goal value is needed in the control process and it is predetermined based on the characters of EMCCD. Simulations and experiments have demonstrated that this auto-gain-control method is valid and robust, the sensing SNR reaches the maximum for the corresponding signal level, and especially is greatly improved for those dim targets from 6 to 4 magnitude in the visual band. (special topic)

Experimental knee joint pain during strength training and muscle strength gain in healthy subjects: a randomized controlled trial.

Science.gov (United States)

Sørensen, T J; Langberg, H; Hodges, P W; Bliddal, H; Henriksen, M

2012-01-01

Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology. Copyright © 2012 by the American College of Rheumatology.

Knotted pipeline

International Nuclear Information System (INIS)

Beer, G.; Slovak, K.

2006-01-01

It is too early to speculate on where the Transpetrol shares will end up. The bankruptcy trustee of Yukos, Eduard Rebgun, has so far received three offers from Gazprom, the Rusneft oil company and the Penta private equity group via its Cyprian company. All three would like to gain control over the Slovak oil transporting company. As yet, no formal request from the Slovak Republic has been delivered to Moscow. By Trend's deadline, President Ivan Gasparovic and the Minister of Economy, Lubomir Jahnatek, were still negotiating in Moscow with the Russian President, Vladimir Putin. One of the topics on the agenda was the future of the company which transports Russian oil to Europe. Both Slovakia and Russia aim to gain control over the stock and the situation is locked in stalemate The stock in question is owned by the Dutch company, Yukos Finance. And although this company is owned by the bankrupt Yukos, the property rights are in the hands of foundation, Stichting Administratiekantoor Yukos International. Yukos Finance is not in bankruptcy and it is therefore difficult to detach the Yukos shares from the company assets. (authors)

An analytical fuzzy-based approach to ?-gain optimal control of input-affine nonlinear systems using Newton-type algorithm

Science.gov (United States)

Milic, Vladimir; Kasac, Josip; Novakovic, Branko

2015-10-01

This paper is concerned with ?-gain optimisation of input-affine nonlinear systems controlled by analytic fuzzy logic system. Unlike the conventional fuzzy-based strategies, the non-conventional analytic fuzzy control method does not require an explicit fuzzy rule base. As the first contribution of this paper, we prove, by using the Stone-Weierstrass theorem, that the proposed fuzzy system without rule base is universal approximator. The second contribution of this paper is an algorithm for solving a finite-horizon minimax problem for ?-gain optimisation. The proposed algorithm consists of recursive chain rule for first- and second-order derivatives, Newton's method, multi-step Adams method and automatic differentiation. Finally, the results of this paper are evaluated on a second-order nonlinear system.

New Gain Controllable Resistor-less Current-mode First Order Allpass Filter and its Application

Directory of Open Access Journals (Sweden)

W. Jaikla

2012-04-01

Full Text Available New first order allpass filter (APF in current mode, constructed from 2 CCCCTAs and grounded capacitor, is presented. The current gain and phase shift can be electronically /orthogonally controlled. Low input and high output impedances are achieved which make the circuit to be easily cascaded to the current-mode circuit without additional current buffers. The operation of the proposed filter has been verified through simulation results which confirm the theoretical analysis. The application example as current-mode quadrature oscillator with non-interactive current control for both of oscillation condition and oscillation frequency is included to show the usability of the proposed filter.

Receiver gain function: the actual NMR receiver gain

OpenAIRE

Mo, Huaping; Harwood, John S.; Raftery, Daniel

2010-01-01

The observed NMR signal size depends on the receiver gain parameter. We propose a receiver gain function to characterize how much the raw FID is amplified by the receiver as a function of the receiver gain setting. Although the receiver is linear for a fixed gain setting, the actual gain of the receiver may differ from what the gain setting suggests. Nevertheless, for a given receiver, we demonstrate that the receiver gain function can be calibrated. Such a calibration enables accurate compar...

Photomultiplier gain stabilisation

International Nuclear Information System (INIS)

Le Baud, P.; Sautiez, B.

1958-07-01

By the control and adjustment of magnetic deflection applied to the electron beam of a photomultiplier it has proved possible to flatten the gain curve, forming plateaux at levels dependent upon the voltage at intake. It should be possible to add this simple device to most photomultipliers on the market today. (author) [fr

Quinine controls body weight gain without affecting food intake in male C57BL6 mice

Directory of Open Access Journals (Sweden)

Cettour-Rose Philippe

2013-02-01

Full Text Available Abstract Background Quinine is a natural molecule commonly used as a flavouring agent in tonic water. Diet supplementation with quinine leads to decreased body weight and food intake in rats. Quinine is an in vitro inhibitor of Trpm5, a cation channel expressed in taste bud cells, the gastrointestinal tract and pancreas. The objective of this work is to determine the effect of diet supplementation with quinine on body weight and body composition in male mice, to investigate its mechanism of action, and whether the effect is mediated through Trpm5. Results Compared with mice consuming AIN, a regular balanced diet, mice consuming AIN diet supplemented with 0.1% quinine gained less weight (2.89 ± 0.30 g vs 5.39 ± 0.50 g and less fat mass (2.22 ± 0.26 g vs 4.33 ± 0.43 g after 13 weeks of diet, and had lower blood glucose and plasma triglycerides. There was no difference in food intake between the mice consuming quinine supplemented diet and those consuming control diet. Trpm5 knockout mice gained less fat mass than wild-type mice. There was a trend for a diet-genotype interaction for body weight and body weight gain, with the effect of quinine less pronounced in the Trpm5 KO than in the WT background. Faecal weight, energy and lipid contents were higher in quinine fed mice compared to regular AIN fed mice and in Trpm5 KO mice compared to wild type mice. Conclusion Quinine contributes to weight control in male C57BL6 mice without affecting food intake. A partial contribution of Trpm5 to quinine dependent body weight control is suggested.

[Body weight gain after radioiodine therapy in hyperthyroidism].

Science.gov (United States)

Scheidhauer, K; Odatzidu, L; Kiencke, P; Schicha, H

2002-02-01

Analysis and follow up of body weight after radioiodine therapy (RITh) of hyperthyroidism, since excessive weight gain is a common complaint among these patients. Therapy and body weight related data of 100 consecutive RITh-patients were retrospectively analysed from the time before up to three years after RITh. All patients suffered from hyperthyroidism (Graves' disease or autonomy), but were adjusted to euthyroid levels after RITh. Patients' data were compared to a control group of 48 euthyroid patients out of the same ambulance and during the same time scale. All patients (RITh and controls) gained weight over the time. There was no statistically significant difference in BMI development over three years between RITh-patients and controls (5.5% resp. 4.9% increase). In the first year after RITh, weight gain of the RITh patients was higher indeed, but lower in the follow up, resulting in the same range of weight gain after three years as the controls. Besides that women showed a slightly higher increase of BMI than men, and so did younger patients compared to elder as well as patients with overweight already before RITh. An initially distinct increase of body weight after RITh of hyperthyroidism is mainly a compensation of pretherapeutic weight loss due to hyperthyroidism. Presupposing adequate euthyroid adjustment of thyroid metabolism after therapy, RITh is not responsible for later weight gain and adipositas.

78 FR 59663 - Combined Notice of Filings

Science.gov (United States)

2013-09-27

... Paso Marketing Company, L.L.C., Gazprom Marketing & Trading USA, Inc. Description: Joint Petition for... Provisions of El Paso Marketing Company, L.L.C. and Gazprom Marketing & Trading USA, Inc. Filed Date: 9/17/13...: Discovery Gas Transmission LLC. Description: 2013 Tariff Revisions--Kinetica Interconnect to be effective 10...

Controlling morphology and chain aggregation in semiconducting conjugated polymers: the role of solvent on optical gain in MEH-PPV.

Science.gov (United States)

Lampert, Zach E; Reynolds, C Lewis; Papanikolas, John M; Aboelfotoh, M Osama

2012-10-25

We report the results of a detailed investigation that addresses the influence of polymer morphology and chain aggregation, as controlled by the chemical nature of the solvent, on the optical gain properties of the conjugated polymer poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV). Using the variable stripe length technique in the picosecond regime, we have extensively studied the optical gain performance of asymmetric planar waveguides formed with thin MEH-PPV films spin-cast from concentrated chlorobenzene (CB) and tetrahydrofuran (THF) solutions onto thermally oxidized silicon substrates. CB and THF solvents were chosen based on their known ability to promote and effectively limit aggregate formation, respectively. Very large net gain coefficients are demonstrated, reaching values of 330 and 365 cm(-1), respectively, when optically pumping the waveguides with a maximum energy density of 85 μJ/cm(2). Our results clearly demonstrate that polymer morphology, and hence, the chain conformation dependence of the degree of aggregation in the films as controlled by the solvent, has minimal impact on the net gain. Moreover, the waveguides exhibit low loss coefficients of 10-20 cm(-1) at the ASE wavelength. These results question the importance of polymer morphology and aggregate formation in polymer-based optical devices operating at high excitation densities in the stimulated emission regime as would be characteristic of lasers and optical amplifiers.

Engineering studies related to Skylab program. [assessment of automatic gain control data

Science.gov (United States)

Hayne, G. S.

1973-01-01

The relationship between the S-193 Automatic Gain Control data and the magnitude of received signal power was studied in order to characterize performance parameters for Skylab equipment. The r-factor was used for the assessment and is defined to be less than unity, and a function of off-nadir angle, ocean surface roughness, and receiver signal to noise ratio. A digital computer simulation was also used to assess to additive receiver, or white noise. The system model for the digital simulation is described, along with intermediate frequency and video impulse response functions used, details of the input waveforms, and results to date. Specific discussion of the digital computer programs used is also provided.

Ekspert: Nord Stream on kaheldav / Jaanus Piirsalu

Index Scriptorium Estoniae

Piirsalu, Jaanus, 1973-

2009-01-01

Konsultatsioonifirma East European Gas Analysis direktor Mihhail Kortšemkin arvab, et Gazprom hülgab Nord Streami projekti, kui ta ei saa Rootsi ja Soome nõusolekut ehitamiseks 2010. aasta jooksul. Tema hinnangul riskib Gazprom pankrotiga, kui hakkab korraga ehitama gaasitoru läbi Läänemere ja Musta mere

Great oak trees from small acorns grow

International Nuclear Information System (INIS)

Bogle, Sally.

1997-01-01

The history of Avalon Oil is briefly outlined. The company has become the first foreign company to sign a joint venture oil deal with Russia's Gazprom. Topics covered include new drilling skills, building relations face-to-face with Gazprom assigning responsibility to the venture partners, tax breaks and political risk. (UK)

Modeling and distributed gain scheduling strategy for load frequency control in smart grids with communication topology changes.

Science.gov (United States)

Liu, Shichao; Liu, Xiaoping P; El Saddik, Abdulmotaleb

2014-03-01

In this paper, we investigate the modeling and distributed control problems for the load frequency control (LFC) in a smart grid. In contrast with existing works, we consider more practical and real scenarios, where the communication topology of the smart grid changes because of either link failures or packet losses. These topology changes are modeled as a time-varying communication topology matrix. By using this matrix, a new closed-loop power system model is proposed to integrate the communication topology changes into the dynamics of a physical power system. The globally asymptotical stability of this closed-loop power system is analyzed. A distributed gain scheduling LFC strategy is proposed to compensate for the potential degradation of dynamic performance (mean square errors of state vectors) of the power system under communication topology changes. In comparison to conventional centralized control approaches, the proposed method can improve the robustness of the smart grid to the variation of the communication network as well as to reduce computation load. Simulation results show that the proposed distributed gain scheduling approach is capable to improve the robustness of the smart grid to communication topology changes. © 2013 ISA. Published by ISA. All rights reserved.

Continuity of midwifery care and gestational weight gain in obese women: a randomised controlled trial

Directory of Open Access Journals (Sweden)

Patterson Denise

2011-03-01

Full Text Available Abstract Background The increased prevalence of obesity in pregnant women in Australia and other developed countries is a significant public health concern. Obese women are at increased risk of serious perinatal complications and guidelines recommend weight gain restriction and additional care. There is limited evidence to support the effectiveness of dietary and physical activity lifestyle interventions in preventing adverse perinatal outcomes and new strategies need to be evaluated. The primary aim of this project is to evaluate the effect of continuity of midwifery care on restricting gestational weight gain in obese women to the recommended range. The secondary aims of the study are to assess the impact of continuity of midwifery care on: women's experience of pregnancy care; women's satisfaction with care and a range of psychological factors. Methods/Design A two arm randomised controlled trial (RCT will be conducted with primigravid women recruited from maternity services in Victoria, Australia. Participants will be primigravid women, with a BMI≥30 who are less than 17 weeks gestation. Women allocated to the intervention arm will be cared for in a midwifery continuity of care model and receive an informational leaflet on managing weight gain in pregnancy. Women allocated to the control group will receive routine care in addition to the same informational leaflet. Weight gain during pregnancy, standards of care, medical and obstetric information will be extracted from medical records. Data collected at recruitment (self administered survey and at 36 weeks by postal survey will include socio-demographic information and the use of validated scales to measure secondary outcomes. Discussion Continuity of midwifery care models are well aligned with current Victorian, Australian and many international government policies on maternity care. Increasingly, midwifery continuity models of care are being introduced in low risk maternity care, and

Body weight gain after radioiodine therapy of hyperthyroidism

International Nuclear Information System (INIS)

Scheidhauer, K.; Odatzidu, L.; Schicha, H.

2002-01-01

Aim: Analysis and follow up of body weight after radioiodine therapy (RITh) of hyperthyroidism, since excessive weight gain is a common complaint among these patients. Methods: Therapy and body weight related data of 100 consecutive RITh-patients were retrospectively analysed from the time before up to three years after RITh. All patients suffered from hyperthyroidism (Graves' disease or autonomy), but were adjusted to euthyroid levels after RITh. Patients' data were compared to a control group of 48 euthyroid patients out of the same ambulance and during the same time scale. Results: All patients (RITh and controls) gained weight over the time. There was no statistically significant difference in BMI development over three years between RITh-patients and controls (5.5% resp. 4.9% increase). In the first year after RITh, weight gain of the RITh patients was higher indeed, but lower in the follow up, resulting in the same range of weight gain after three years as the controls. Besides that women showed a slightly higher increase of BMI than men, and so did younger patients compared to elder as well as patients with overweight already before RITh. Conclusions: An initially distinct increase of body weight after RITh of hyperthyroidism is mainly a compensation of pretherapeutic weight loss due to hyperthyroidism. Presupposing adequate euthyroid adjustment of thyroid metabolism after therapy, RITh is not responsible for later weight gain and adipositas. (orig.) [de

The Russian gas roads to the Western Europe

International Nuclear Information System (INIS)

Rezunenko, V.I.

1996-01-01

In order to meet with the increasing demand of natural gas, Gazprom thinks non only to develop the existing roads but also to open new ones in the north and the south of Europe. In this future prospect, Gazprom plans to actively participate to the electric power production from natural gas. (O.M.)

Latvijas Gaze buyback likely to flop

Index Scriptorium Estoniae

2003-01-01

Veerandi Läti gaasifirma Latvijas Gaze omanik Itera kavatseb lähiajal lõpule viia üheksa protsendi Läti firma aktsiate müügi ettevõttele Gazprom. Gazprom'i kontrolli all on praegu 25 protsenti, Ruhrgas'il 28,66 ning E.ON Energie AG-l 18,06 protsenti Latvijas Gaze aktsiatest

Design of a low noise distributed amplifier with adjustable gain control in 0.15 μm GaAs PHEMT

International Nuclear Information System (INIS)

Zhang Ying; Wang Zhigong; Xu Jian; Luo Yin

2012-01-01

A low noise distributed amplifier consisting of 9 gain cells is presented. The chip is fabricated with 0.15-μm GaAs pseudomorphic high electron mobility transistor (PHEMT) technology from Win Semiconductor of Taiwan. A special optional gate bias technique is introduced to allow an adjustable gain control range of 10 dB. A novel cascode structure is adopted to extend the output voltage and bandwidth. The measurement results show that the amplifier gives an average gain of 15 dB with a gain flatness of ±1 dB in the 2–20 GHz band. The noise figure is between 2 and 4.1 dB during the band from 2 to 20 GHz. The amplifier also provides 13.8 dBm of output power at a 1 dB gain compression point and 10.5 dBm of input third order intercept point (IIP3), which demonstrates the excellent performance of linearity. The power consumption is 300 mW with a supply of 5 V, and the chip area is 2.36 × 1.01 mm 2 . (semiconductor integrated circuits)

EU Policy. A Debate on EU Energy Policy

International Nuclear Information System (INIS)

Cohen, R.; Kjoelbye, L.; Aaslund, A.; Zwitserloot, R.

2008-01-01

Views from four experts in the field of energy on the EU's energy policy, as laid down in the Third Package, are presented. Kjoelbye and Cohen argue about the pros and cons of unbundling, Aaslund defends the policy of reciprocity towards Gazprom, and Zwitserloot warns that Europe's anti-Gazprom policy endangers security of supply

Valgevene sai Gazpromilt nädala hingetõmbeaega võla tasumiseks / Kaivo Kopli

Index Scriptorium Estoniae

Kopli, Kaivo

2007-01-01

Valgevene maksis Venemaa gaasiettevõttele Gazprom poole kogunenud võlast, kuid Vene ettevõte nõuab kõigi võlgnevuste tasumist nädala jooksul. President Aljaksandr Lukashenka sõnul püüab Venemaa gaasivõlga kasutades sundida Valgevenet oma väärtuslikemaid varasid müüma sellistele ettevõtetele nagu Gazprom

Alliances - Another Way to Access the Market

International Nuclear Information System (INIS)

Komarov, Yuri A.

1999-01-01

The late 1990s were a difficult period for the world economy: decreased economic growth rate, dropping prices for energy and other raw materials, dropping import prices of natural gas. Companies involved in the energy business are currently at the stage of survival. High-priced projects with increased risks are postponed until better times. Consequently, Gazprom had to cut investments by two thirds. For Gazprom, the problems have been aggravated by the transition from authoritatively planned economy to market economy. Alliances are one of the most effective current methods of operation in the natural gas market. Alliances between Gazprom and leading Western oil and gas companies are beneficial both to the participants and the consumers because such alliances will provide for creation of a service package of the 21th century. The importance for Gazprom of cooperation with its alliance partners is that it makes it possible to implement cost-cutting measures that benefit both producers and consumers. It also makes it possible to ensure reliable distribution of the gas

A randomized, placebo-controlled study of zonisamide to prevent olanzapine-associated weight gain.

Science.gov (United States)

McElroy, Susan L; Winstanley, Erin; Mori, Nicole; Martens, Brian; McCoy, Jessica; Moeller, Dianna; Guerdjikova, Anna I; Keck, Paul E

2012-04-01

Weight gain is commonly observed with olanzapine treatment. Zonisamide is an antiepileptic drug associated with weight loss. This study examined the effectiveness of zonisamide in preventing weight gain in 42 patients beginning olanzapine for bipolar disorder or schizophrenia. Each patient had a body mass index of 22 mg/kg or greater and was randomized to taking olanzapine with either zonisamide (n = 20) or placebo (n = 22) for 16 weeks. The primary outcome measure was change in body weight in kilograms from baseline. In the primary analysis using longitudinal regression, patients who received zonisamide had a significantly slower rate of weight gain and increase in body mass index than those who received placebo. The patients treated with zonisamide gained a mean (SD) of 0.9 (3.3) kg, whereas those treated with placebo gained a mean (SD) of 5.0 (5.5) kg; P = 0.01. None of the patients in the zonisamide group, compared with 7 patients (33%) in the placebo group, gained 7% of body weight or greater from baseline (Fisher exact test, P = 0.009). The zonisamide group, however, reported significantly more cognitive impairment as an adverse event than the placebo group (25% vs 0, respectively; P = 0.02). Zonisamide was effective for mitigating weight gain in patients with bipolar disorder or schizophrenia initiating treatment with olanzapine but was associated with cognitive impairment as an adverse event.

Mode control in a high-gain relativistic klystron amplifier

Science.gov (United States)

Li, Zheng-Hong; Zhang, Hong; Ju, Bing-Quan; Su, Chang; Wu, Yang

2010-05-01

Middle cavities between the input and output cavity can be used to decrease the required input RF power for the relativistic klystron amplifier. Meanwhile higher modes, which affect the working mode, are also easy to excite in a device with more middle cavities. In order for the positive feedback process for higher modes to be excited, a special measure is taken to increase the threshold current for such modes. Higher modes' excitation will be avoided when the threshold current is significantly larger than the beam current. So a high-gain S-band relativistic klystron amplifier is designed for the beam of current 5 kA and beam voltage 600 kV. Particle in cell simulations show that the gain is 1.6 × 105 with the input RF power of 6.8 kW, and that the output RF power reaches 1.1 GW.

Beam energy gain fluctuation in a linac caused by RF system noise

International Nuclear Information System (INIS)

Sakaki, H.; Yoshikawa, H.; Hori, T.; Yokomizo, H.

2002-01-01

In this paper, energy gain fluctuation caused by white noise in a linear accelerator is calculated. First, we formulate a computational procedure to determine the energy gain in the acceleration structure. Then, using this computational procedure, the size of the white noise of the gain is calculated. These noise sources are caused by various RF components, especially the thyratron. The calculated gain fluctuation per one RF system is ±0.054%∼±0.134%(±3σ). In general, it is difficult to control white noise. This gain fluctuation is composed only of the white noise. Therefore, this value has the same meaning as a 'Control threshold'. Thus, the control method can be evaluated based on this value

Effect of massage stimulation on weight gain in full term infants

Directory of Open Access Journals (Sweden)

Nyoman Nursari Dewi

2011-08-01

Full Text Available Background Massage is a tactile/kinesthetic stimulation with biochemical and physiological effects on the body. Newborn infant massage stimulation given by mothers may promote maternal-infant bonding and attachment, enhance infant weight gain and stimulate the production of breast milk. There have been few studies on the effect of massage stimulation on weight gain in full term infants, and this topic remains controversial. Objective To examine the effect of massage stimulation on weight gain in full term infants. Methods This quasi-experimental study was held in Sanglah Hospital and Bunda Setia Maternity Clinic. Massage stimulation was performed by mothers once daily for a four week period. Massage stimulation was given to 30 full term infants and their weight gain was compared to 31 control infants who did not receive massages. Results There were no differences in subject characteristics between the massage and control groups. Median weight gain in the massage group was 1230 grams, while that in the control group was 830 grams (P=0.028. Conclusion Weight gain in full term infants in the massage group was significantly greater than that in the control group after 4 weeks.

Faster, more intense! The relation between electrophysiological reflections of attentional orienting, sensory gain control, and speed of responding

NARCIS (Netherlands)

Talsma, D.; Mulckhuyse, Manon; Slagter, Heleen A.; Theeuwes, Jan

2007-01-01

Selective visual attention is thought to facilitate goal-directed behavior by biasing the system in advance to favor certain stimuli over others, resulting in their selective processing. The aim of the present study was to gain more insight into the link between control processes that induce a

Determining productivity gains from herbaceous vegetation management with 'age-shift' calculations

Science.gov (United States)

David B. South; James H. Miller; Mark O. Kimberley; Curtis L. Vanderschaaf

2006-01-01

Gains in stand volume that result from competition control and fertilization are sometimes reported as 'percentage gains'. Because percentage gains arithmetically decline over time asstand volume increases, plantation managers have difficultyin using percentage gains to project growth and revenues. The 'age-shift' method quantifies the year...

Gas-workers not wonts by only carriers

International Nuclear Information System (INIS)

Hirman, K.

2003-01-01

Paper deals with the own production of the co-owner of the Slovensky plynarensky podnik, a. s. (SPP). Gas de France mines gas in North Sea shelf. Algeria and Egypt should become the important source in next years. Ruhrgas also mines in North Sea. It owns 6.5% part in Gazprom. Ruhrgaz is interested in gas production directly in Russian Federation. Preliminary discussions are going hand in hand with Lukoil and Sevmorneftegaz companies. Lukoil supposes that possible attendance of Ruhrgas should help to get necessary capital of 1.5 billions Euro. Ruhrgaz is interested in gigantic Shtokmanovskoe deposit in Barents Sea shelf of Sevmorneftegaz Company. Total capital costs are estimated to 18 billions USD. But one of the problems remaining is closed statute of this part of Russian Arctic. Gazprom is also interested in new sources. Gazprom signed contract with Turkmenistan. Gazprom will purchase two trillions m 3 of gas until 2028 in accordance with it. In present time the export to Europe represents 135 billions m 3 annually, but according to signed long-term contracts this capacity will increase up to 180 billions m 3 after 2008. Because the domestic Russian mining is descending or stagnating, Gazprom is unable to start exploitation of new gigantic deposits in Yamal, company is forced to cover threatening deficit of gas by deliveries from Turkmenistan, Uzbekistan and Kazakhstan. So the possible competition of these countries is simultaneously eliminated in international markets. (Author)

How does a specific learning and memory system in the mammalian brain gain control of behavior?

Science.gov (United States)

McDonald, Robert J; Hong, Nancy S

2013-11-01

This review addresses a fundamental, yet poorly understood set of issues in systems neuroscience. The issues revolve around conceptualizations of the organization of learning and memory in the mammalian brain. One intriguing, and somewhat popular, conceptualization is the idea that there are multiple learning and memory systems in the mammalian brain and they interact in different ways to influence and/or control behavior. This approach has generated interesting empirical and theoretical work supporting this view. One issue that needs to be addressed is how these systems influence or gain control of voluntary behavior. To address this issue, we clearly specify what we mean by a learning and memory system. We then review two types of processes that might influence which memory system gains control of behavior. One set of processes are external factors that can affect which system controls behavior in a given situation including task parameters like the kind of information available to the subject, types of training experience, and amount of training. The second set of processes are brain mechanisms that might influence what memory system controls behavior in a given situation including executive functions mediated by the prefrontal cortex; switching mechanisms mediated by ascending neurotransmitter systems, the unique role of the hippocampus during learning. The issue of trait differences in control of different learning and memory systems will also be considered in which trait differences in learning and memory function are thought to potentially emerge from differences in level of prefrontal influence, differences in plasticity processes, differences in ascending neurotransmitter control, differential access to effector systems like motivational and motor systems. Finally, we present scenarios in which different mechanisms might interact. This review was conceived to become a jumping off point for new work directed at understanding these issues. The outcome of

Stability, gain, and robustness in quantum feedback networks

International Nuclear Information System (INIS)

D'Helon, C.; James, M. R.

2006-01-01

In this paper we are concerned with the problem of stability for quantum feedback networks. We demonstrate in the context of quantum optics how stability of quantum feedback networks can be guaranteed using only simple gain inequalities for network components and algebraic relationships determined by the network. Quantum feedback networks are shown to be stable if the loop gain is less than one--this is an extension of the famous small gain theorem of classical control theory. We illustrate the simplicity and power of the small gain approach with applications to important problems of robust stability and robust stabilization

Effects of lifestyle intervention in obese pregnant women on gestational weight gain and mental health : A randomized controlled trial

NARCIS (Netherlands)

Bogaerts, A.F.L.; Devlieger, R.; Nuyts, E.; Witters, I.; Gyselaers, W.; Van den Bergh, B.R.H.

2013-01-01

Objective: Lifestyle intervention could help obese pregnant women to limit their weight gain during pregnancy and improve their psychological comfort, but has not yet been evaluated in randomized controlled trials. We evaluated whether a targeted antenatal lifestyle intervention programme for obese

Weight Gain Prevention among Midlife Women: A Randomized Controlled Trial to Address Needs Related to the Physical and Social Environment

Directory of Open Access Journals (Sweden)

Courtney D. Perry

2016-05-01

Full Text Available Women tend to gain weight at midlife (40–60 years increasing risk of obesity-related chronic diseases. Within specific eating occasions, needs related to the physical and social environment may result in less healthy eating behavior, which can lead to weight gain over time. The purpose of this study was to determine if a dietitian-delivered nutrition counseling intervention tailored to eating occasion needs could improve diet and prevent weight gain among midlife women over two years. A randomized controlled trial was conducted with healthy midlife women (n = 354 in one U.S. metropolitan area. The intervention group (n = 185 received ten hours of individual nutrition counseling from dietitians over six months, while women in a control group (n = 169 received no counseling. Measured height, weight and waist circumference, and dietary intakes were collected at baseline and every six months over two years. Mixed linear models were used to test for intervention effect on change in outcome variables over time. Dietary intakes of fruit, reduced/low-fat dairy foods and refined grains were significantly improved over time in the intervention compared to control group. However, the intervention had no effect on weight over time (p = 0.48. Nutrition counseling tailored to address eating occasion needs improved self-reported diet but did not significantly affect weight change.

Double-differential recording and AGC using microcontrolled variable gain ASIC.

Science.gov (United States)

Rieger, Robert; Deng, Shin-Liang

2013-01-01

Low-power wearable recording of biopotentials requires acquisition front-ends with high common-mode rejection for interference suppression and adjustable gain to provide an optimum signal range to a cascading analogue-to-digital stage. A microcontroller operated double-differential (DD) recording setup and automatic gain control circuit (AGC) are discussed which reject common-mode interference and provide tunable gain, thus compensating for imbalance and variation in electrode interface impedance. Custom-designed variable gain amplifiers (ASIC) are used as part of the recording setup. The circuit gain and balance is set by the timing of microcontroller generated clock signals. Measured results are presented which confirm that improved common-mode rejection is achieved compared to a single differential amplifier in the presence of input network imbalance. Practical measured examples further validate gain control suitable for biopotential recording and power-line rejection for wearable ECG and EMG recording. The prototype front-end consumes 318 μW including amplifiers and microcontroller.

Robust Model Predictive Control of a Nonlinear System with Known Scheduling Variable and Uncertain Gain

DEFF Research Database (Denmark)

Mirzaei, Mahmood; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

2012-01-01

Robust model predictive control (RMPC) of a class of nonlinear systems is considered in this paper. We will use Linear Parameter Varying (LPV) model of the nonlinear system. By taking the advantage of having future values of the scheduling variable, we will simplify state prediction. Because...... of the special structure of the problem, uncertainty is only in the B matrix (gain) of the state space model. Therefore by taking advantage of this structure, we formulate a tractable minimax optimization problem to solve robust model predictive control problem. Wind turbine is chosen as the case study and we...... choose wind speed as the scheduling variable. Wind speed is measurable ahead of the turbine, therefore the scheduling variable is known for the entire prediction horizon....

Phase and gain measurements in a distributed-loss cyclotron-resonance maser amplifier

International Nuclear Information System (INIS)

Kesar, Amit; Jerby, Eli

2002-01-01

The control of gain and phase delay in a cyclotron-resonance maser (CRM) amplifier is essential for a variety of applications. In this experiment, the gain and phase-delay variations are measured with respect to controlling parameters; the electron-beam current and the axial magnetic field. Following Chu et al. [Phys. Rev. Lett. 74, 1103 (1995)], the CRM amplifier comprises of a distributed-loss waveguide to enable high gain without oscillations. Our experiment yields an amplification up to 26 dB, and a phase-delay control range of 360 deg. In order to keep a fixed gain with the varying phase delay, the two controlling parameters (i.e., the solenoid field and the beam current) are operated together in a compensating mode. The experiment is conducted in a frequency of 7.3 GHz, with an electron beam of 18-kV voltage and 0.25-0.4-A current. The experimental results are compared with a theoretical model. Practical implementations of gain and phase control in CRM devices are discussed

Russian natural gas exports-Will Russian gas price reforms improve the European security of supply?

International Nuclear Information System (INIS)

Sagen, Eirik Lund; Tsygankova, Marina

2008-01-01

In this paper we use both theoretical and numerical tools to study potential effects on Russian gas exports from different Russian domestic gas prices and production capacities in 2015. We also investigate whether a fully competitive European gas market may provide incentives for Gazprom, the dominant Russian gas company, to change its export behaviour. Our main findings suggest that both increased domestic gas prices and sufficient production capacities are vital to maintain Gazprom's market share in Europe over the next decade. In fact, Russia may struggle to carry out its current long-term export commitments if domestic prices are sufficiently low. At the same time, if Russian prices approach European net-back levels, Gazprom may reduce exports in favour of a relatively more profitable domestic market

Weight suppression predicts total weight gain and rate of weight gain in outpatients with anorexia nervosa.

Science.gov (United States)

Carter, Frances A; Boden, Joseph M; Jordan, Jennifer; McIntosh, Virginia V W; Bulik, Cynthia M; Joyce, Peter R

2015-11-01

The present study sought to replicate the finding of Wildes and Marcus, Behav Res Ther, 50, 266-274, 2012 that higher levels of weight suppression at pretreatment predict greater total weight gain, faster rate of weight gain, and bulimic symptoms amongst patients admitted with anorexia nervosa. Participants were 56 women with anorexia nervosa diagnosed by using strict or lenient weight criteria, who were participating in a randomized controlled psychotherapy trial (McIntosh et al., Am J Psychiatry, 162, 741-747, 2005). Thirty-five women completed outpatient treatment and post-treatment assessment. Weight suppression was the discrepancy between highest lifetime weight at adult height and weight at pretreatment assessment. Outcome variables were total weight gain, rate of weight gain, and bulimic symptoms in the month prior to post-treatment assessment [assessed using the Eating Disorders Examination (Fairburn et al., Binge-Eating: Nature, Assessment and Treatment. New York: Guilford, 1993)]. Weight suppression was positively associated with total weight gain and rate of weight gain over treatment. Regression models showed that this association could not be explained by covariates (age at onset of anorexia nervosa and treatment modality). Weight suppression was not significantly associated with bulimic symptoms in the month prior to post-treatment assessment, regardless of whether bulimic symptoms were examined as continuous or dichotomous variables. The present study reinforces the previous finding that weight suppression predicts total weight gain and rate of weight gain amongst patients being treated for anorexia nervosa. Methodological issues may explain the failure of the present study to find that weight suppression predicts bulimic symptoms. Weight suppression at pretreatment for anorexia nervosa should be assessed routinely and may inform treatment planning. © 2015 Wiley Periodicals, Inc.

A 60-dB linear VGA with novel exponential gain approximation

International Nuclear Information System (INIS)

Zhou Jiaye; Tan Xi; Wang Junyu; Tang Zhangwen; Min Hao

2009-01-01

A CMOS variable gain amplifier (VGA) that adopts a novel exponential gain approximation is presented. No additional exponential gain control circuit is required in the proposed VGA used in a direct conversion receiver. A wide gain control voltage from 0.4 to 1.8 V and a high linearity performance are achieved. The three-stage VGA with automatic gain control (AGC) and DC offset cancellation (DCOC) is fabricated in a 0.18-μm CMOS technology and shows a linear gain range of more than 58-dB with a linearity error less than ±1 dB. The 3-dB bandwidth is over 8 MHz at all gain settings. The measured input-referred third intercept point (IIP3) of the proposed VGA varies from -18.1 to 13.5 dBm, and the measured noise figure varies from 27 to 65 dB at a frequency of 1 MHz. The dynamic range of the closed-loop AGC exceeds 56 dB, where the output signal-to-noise-and-distortion ratio (SNDR) reaches 20 dB. The whole circuit, occupying 0.3 mm 2 of chip area, dissipates less than 3.7 mA from a 1.8-V supply.

Health coaching to prevent excessive gestational weight gain: A randomized-controlled trial.

Science.gov (United States)

Skouteris, Helen; McPhie, Skye; Hill, Briony; McCabe, Marita; Milgrom, Jeannette; Kent, Bridie; Bruce, Lauren; Herring, Sharon; Gale, Janette; Mihalopoulos, Cathrine; Shih, Sophy; Teale, Glyn; Lachal, Jennifer

2016-02-01

The objectives of this study were to evaluate the efficacy of a health coaching (HC) intervention designed to prevent excessive gestational weight gain (GWG), and promote positive psychosocial and motivational outcomes in comparison with an Education Alone (EA) group. Randomized-controlled trial. Two hundred and sixty-one women who were <18 weeks pregnant consented to take part. Those allocated to the HC group received a tailored HC intervention delivered by a Health Coach, whilst those in the EA group attended two education sessions. Women completed measures, including motivation, psychosocial variables, sleep quality, and knowledge, beliefs and expectations concerning GWG, at 15 weeks of gestation (Time 1) and 33 weeks of gestation (Time 2). Post-birth data were also collected at 2 months post-partum (Time 3). There was no intervention effect in relation to weight gained during pregnancy, rate of excessive GWG or birth outcomes. The only differences between HC and EA women were higher readiness (b = 0.29, 95% CIs = 0.03-0.55, p < .05) and the importance to achieve a healthy GWG (b = 0.27, 95% CIs = 0.02-0.52, p < .05), improved sleep quality (b = -0.22, 95% CIs = -0.44 to -0.03, p < .05), and increased knowledge for an appropriate amount of GWG that would be best for their baby's health (b = -1.75, 95% CI = -3.26 to -0.24, p < .05) reported by the HC at Time 2. Whilst the HC intervention was not successful in preventing excessive GWG, several implications for the design of future GWG interventions were identified, including the burden of the intervention commitment and the use of weight monitoring. What is already known on the subject? Designing interventions to address gestational weight gain (GWG) continues to be a challenge. To date, health behaviour change factors have not been the focus of GWG interventions. What does this study add? Our health coaching (HC) intervention did not reduce GWG more so than education alone (EA). There was an intervention effect

Association between smoking cessation and weight gain in treatment-seeking African Americans.

Science.gov (United States)

Tan, Marcia M; Okuyemi, Kolawole S; Resnicow, Ken; Dietz, Noella A; Antoni, Michael H; Webb Hooper, Monica

2018-06-01

Research has shown that African Americans gain more than average weight after smoking cessation. However, African Americans have been underrepresented in post-cessation weight gain research. The current study examined 1) the pattern of weight gain and 2) the association between smoking status and weight gain in a sample of African Americans seeking smoking cessation treatment. Data were drawn from a randomized controlled trial testing the efficacy of a 4-week culturally specific smoking cessation cognitive behavioral therapy (CBT) intervention among African American smokers (N = 342). Weight was measured and self-reported smoking status was biochemically verified at baseline, end of counseling, 3-, 6-, and 12-month follow-ups. Random effects multilevel modeling was used to examine weight gain over twelve months post CBT, and a fully unconditional model tested the pattern of weight gain over time. Smoking status was included as a time-varying factor to examine its effect on weight gain, controlling for potential confounding variables. Weight significantly increased among those who remained abstinent over 12 months post CBT [average gain of seven lbs. (three kg)]. Controlling for covariates, abstinence was predictive of the rate of weight gain for those with high weight concern. Weight gain among African American abstainers was comparable to the average post-cessation weight gain observed among the general population. It is possible that exposure to CBT (culturally specific or standard) may have mitigated excessive weight gain. Future research should assess predictors of weight gain in African American smokers to inform future smoking cessation interventions and help elucidate factors that contribute to tobacco- and obesity-related health disparities. Copyright © 2018 Elsevier Ltd. All rights reserved.

Kremlis pannakse paika maagaasi hinnatõus Eestis / Vallo Toomet

Index Scriptorium Estoniae

Toomet, Vallo, 1960-

2005-01-01

Vene riigiduuma esitas 8. juulil peaminister Mihhail Fradkovile pöördumise, milles palutakse vaadata üle Eestisse, Lätisse, Leedusse, Ukrainasse ja Moldovasse tarnitava gaasi hind. Lisa: Eesti Gaasil on üle 120 000 kliendi. Vt. samas: Gaasitrass Saksamaale. Kaart: Gazprom osaleb uue gaasitoru rajamisel; Gazprom - Vene riigi rahasalv. Vt. samas lühiintervjuud Eesti Gaasi müügiteenuste ettevõtte direktori Raul Kotoviga

Intake of Sweets, Snacks and Soft Drinks Predicts Weight Gain in Obese Pregnant Women: Detailed Analysis of the Results of a Randomised Controlled Trial.

Science.gov (United States)

Renault, Kristina M; Carlsen, Emma M; Nørgaard, Kirsten; Nilas, Lisbeth; Pryds, Ole; Secher, Niels J; Olsen, Sjurdur F; Halldorsson, Thorhallur I

2015-01-01

Lifestyle interventions targeting obese pregnant women often result in modest reduction in gestational weight gain, pregnancy complications and related risk factors. Examining adherence to the intervention can, however, provide valuable information on the importance of the different factors targeted. To evaluate improvements and relevance of different dietary factors targeted with respect to gestational weight gain in a 3-arm Randomised Controlled Trial (n=342) among obese pregnant women with BMI≥30 kg/m2. Randomisation 1:1:1 to either hypocaloric Mediterranean type of diet and physical activity intervention (D+PA); physical activity intervention alone (PA); or control (C). Diet was assessed at baseline (weeks 11-14) and endpoint (weeks 36-37) using a validated food frequency questionnaire. During the intervention women in the D+PA group significantly lowered their intakes of added sugars and saturated fat and increased their protein intake by ~1% of total energy compared to controls. Of these dietary variables only intakes of added sugar appeared to be related to GWG, while no association was observed for saturated fat or protein. Further analyses revealed that foods that contributed to intake of added sugars, including sweets, snacks, cakes, and soft drinks were strongly associated with weight gain, with women consuming sweets ≥2/day having 5.4 kg (95% CI 2.1-8.7) greater weight gain than those with a low (<1wk) intake. The results for soft drinks were more conflicting, as women with high weight gain tended to favour artificially sweetened soft drinks. In our sample of obese pregnant women, craving for sweets, snacks, and soft drinks strongly predicts GWG. Emphasis on reducing intakes of these foods may be more relevant for limiting gestational weight gain than encouraging strict compliance to more specific diets. ClinicalTrials.gov NCT01345149.

Intake of Sweets, Snacks and Soft Drinks Predicts Weight Gain in Obese Pregnant Women: Detailed Analysis of the Results of a Randomised Controlled Trial.

Directory of Open Access Journals (Sweden)

Kristina M Renault

Full Text Available Lifestyle interventions targeting obese pregnant women often result in modest reduction in gestational weight gain, pregnancy complications and related risk factors. Examining adherence to the intervention can, however, provide valuable information on the importance of the different factors targeted.To evaluate improvements and relevance of different dietary factors targeted with respect to gestational weight gain in a 3-arm Randomised Controlled Trial (n=342 among obese pregnant women with BMI≥30 kg/m2.Randomisation 1:1:1 to either hypocaloric Mediterranean type of diet and physical activity intervention (D+PA; physical activity intervention alone (PA; or control (C. Diet was assessed at baseline (weeks 11-14 and endpoint (weeks 36-37 using a validated food frequency questionnaire.During the intervention women in the D+PA group significantly lowered their intakes of added sugars and saturated fat and increased their protein intake by ~1% of total energy compared to controls. Of these dietary variables only intakes of added sugar appeared to be related to GWG, while no association was observed for saturated fat or protein. Further analyses revealed that foods that contributed to intake of added sugars, including sweets, snacks, cakes, and soft drinks were strongly associated with weight gain, with women consuming sweets ≥2/day having 5.4 kg (95% CI 2.1-8.7 greater weight gain than those with a low (<1wk intake. The results for soft drinks were more conflicting, as women with high weight gain tended to favour artificially sweetened soft drinks.In our sample of obese pregnant women, craving for sweets, snacks, and soft drinks strongly predicts GWG. Emphasis on reducing intakes of these foods may be more relevant for limiting gestational weight gain than encouraging strict compliance to more specific diets.ClinicalTrials.gov NCT01345149.

Neuronal gain modulability is determined by dendritic morphology: A computational optogenetic study.

Science.gov (United States)

Jarvis, Sarah; Nikolic, Konstantin; Schultz, Simon R

2018-03-01

The mechanisms by which the gain of the neuronal input-output function may be modulated have been the subject of much investigation. However, little is known of the role of dendrites in neuronal gain control. New optogenetic experimental paradigms based on spatial profiles or patterns of light stimulation offer the prospect of elucidating many aspects of single cell function, including the role of dendrites in gain control. We thus developed a model to investigate how competing excitatory and inhibitory input within the dendritic arbor alters neuronal gain, incorporating kinetic models of opsins into our modeling to ensure it is experimentally testable. To investigate how different topologies of the neuronal dendritic tree affect the neuron's input-output characteristics we generate branching geometries which replicate morphological features of most common neurons, but keep the number of branches and overall area of dendrites approximately constant. We found a relationship between a neuron's gain modulability and its dendritic morphology, with neurons with bipolar dendrites with a moderate degree of branching being most receptive to control of the gain of their input-output relationship. The theory was then tested and confirmed on two examples of realistic neurons: 1) layer V pyramidal cells-confirming their role in neural circuits as a regulator of the gain in the circuit in addition to acting as the primary excitatory neurons, and 2) stellate cells. In addition to providing testable predictions and a novel application of dual-opsins, our model suggests that innervation of all dendritic subdomains is required for full gain modulation, revealing the importance of dendritic targeting in the generation of neuronal gain control and the functions that it subserves. Finally, our study also demonstrates that neurophysiological investigations which use direct current injection into the soma and bypass the dendrites may miss some important neuronal functions, such as gain

An analytical method for PID controller tuning with specified gain and phase margins for integral plus time delay processes.

Science.gov (United States)

Hu, Wuhua; Xiao, Gaoxi; Li, Xiumin

2011-04-01

In this paper, an analytical method is proposed for proportional-integral/proportional-derivative/proportional-integral-derivative (PI/PD/PID) controller tuning with specified gain and phase margins (GPMs) for integral plus time delay (IPTD) processes. Explicit formulas are also obtained for estimating the GPMs resulting from given PI/PD/PID controllers. The proposed method indicates a general form of the PID parameters and unifies a large number of existing rules as PI/PD/PID controller tuning with various GPM specifications. The GPMs realized by existing PID tuning rules are computed and documented as a reference for control engineers to tune the PID controllers. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Attenuating effect of reboxetine on appetite and weight gain in olanzapine-treated schizophrenia patients: a double-blind placebo-controlled study.

Science.gov (United States)

Poyurovsky, Michael; Fuchs, Camil; Pashinian, Artashez; Levi, Aya; Faragian, Sarit; Maayan, Rachel; Gil-Ad, Irit

2007-06-01

Search for safe and effective strategies to diminish weight gain associated with second generation antipsychotics (SGAs) is imperative. In the present study, we sought to replicate our preliminary findings, which indicated that coadministration of the selective norepinephrine reuptake inhibitor reboxetine attenuates olanzapine-induced weight gain. Fifty-nine patients hospitalized for first-episode DSM-IV schizophrenic disorder participated in this randomized double-blind study. Reboxetine (4 mg/day; 31 patients) or placebo (29 patients) was coadministered with olanzapine (10 mg/day) for 6 weeks. Analysis was by intention-to-treat. Nine patients in each group prematurely discontinued the trial. Olanzapine/reboxetine-treated patients showed a significantly lower increase in body weight (mean = 3.31 kg, SD = 2.73) than their olanzapine/placebo-treated counterparts (mean = 4.91 kg, SD = 2.45). Significantly fewer olanzapine/reboxetine-treated patients gained at least 7% of their initial weight, the cutoff for clinically significant weight gain (6 [19.4%] of 31 patients vs 13 [46.4%] of 28 patients). Seven (22.6%) olanzapine/reboxetine-treated patients compared to only one patient (3.6%) in the olanzapine/placebo group revealed no weight change or even modest weight loss. Appetite increase was significantly lower in the olanzapine/reboxetine than olanzapine/placebo group and was correlated with attenuation of weight gain. Reboxetine addition was safe and well tolerated. The results confirm that coadministration of reboxetine promotes a clinically meaningful attenuation of olanzapine-induced weight gain in schizophrenia patients. If substantiated in long-term studies, along with behavioral management and diet counseling, reboxetine may have a clinical utility in controlling SGA-induced weight gain.

Transformation of CLF to ISS-CLF for Nonlinear Systems with Disturbance and Construction of Nonlinear Robust Controller with L2 Gain Performance

Directory of Open Access Journals (Sweden)

Keizo Okano

2014-01-01

Full Text Available A new nonlinear control law for a class of nonlinear systems with disturbance is proposed. A control law is designed by transforming control Lyapunov function (CLF to input-to-state stability control Lyapunov function (ISS-CLF. The transformed CLF satisfies a Hamilton-Jacobi-Isaacs (HJI equation. The feedback system by the proposed control law has characteristics of L2 gain. Finally, it is shown by a numerical example that the proposed control law makes a controller by feedback linearization robust against disturbance.

Realisations of single-resistance-controlled quadrature oscillators using a generalised current follower transconductance amplifier and a unity-gain voltage-follower

OpenAIRE

Herencsár, Norbert; Vrba, Kamil; Koton, Jaroslav; Lahiri, Abhirup

2010-01-01

This article presents realisations of single-resistance-controlled-oscillators (SRCOs) using the recently proposed modern active building block (ABB), namely the generalised current follower transconductance amplifier (GCFTA) and unity-gain voltage-follower (UGVF). The SRCO is made using reduced number of components: one GCFTA and one UGVF as the ABBs, two resistors and two grounded capacitors. The circuit offers the advantage of non-interactive control of condition of oscillation and frequen...

Regulation of Blood Glucose Concentration in Type 1 Diabetics Using Single Order Sliding Mode Control Combined with Fuzzy On-line Tunable Gain, a Simulation Study.

Science.gov (United States)

Dinani, Soudabeh Taghian; Zekri, Maryam; Kamali, Marzieh

2015-01-01

Diabetes is considered as a global affecting disease with an increasing contribution to both mortality rate and cost damage in the society. Therefore, tight control of blood glucose levels has gained significant attention over the decades. This paper proposes a method for blood glucose level regulation in type 1 diabetics. The control strategy is based on combining the fuzzy logic theory and single order sliding mode control (SOSMC) to improve the properties of sliding mode control method and to alleviate its drawbacks. The aim of the proposed controller that is called SOSMC combined with fuzzy on-line tunable gain is to tune the gain of the controller adaptively. This merit causes a less amount of control effort, which is the rate of insulin delivered to the patient body. As a result, this method can decline the risk of hypoglycemia, a lethal phenomenon in regulating blood glucose level in diabetics caused by a low blood glucose level. Moreover, it attenuates the chattering observed in SOSMC significantly. It is worth noting that in this approach, a mathematical model called minimal model is applied instead of the intravenously infused insulin-blood glucose dynamics. The simulation results demonstrate a good performance of the proposed controller in meal disturbance rejection and robustness against parameter changes. In addition, this method is compared to fuzzy high-order sliding mode control (FHOSMC) and the superiority of the new method compared to FHOSMC is shown in the results.

A model-based gain scheduling approach for controlling the common-rail system for GDI engines

Science.gov (United States)

di Gaeta, Alessandro; Montanaro, Umberto; Fiengo, Giovanni; Palladino, Angelo; Giglio, Veniero

2012-04-01

The progressive reduction in vehicle emission requirements have forced the automotive industry to invest in research for developing alternative and more efficient control strategies. All control features and resources are permanently active in an electronic control unit (ECU), ensuring the best performance with respect to emissions, fuel economy, driveability and diagnostics, independently from engine working point. In this article, a considerable step forward has been achieved by the common-rail technology which has made possible to vary the injection pressure over the entire engine speed range. As a consequence, the injection of a fixed amount of fuel is more precise and multiple injections in a combustion cycle can be made. In this article, a novel gain scheduling pressure controller for gasoline direct injection (GDI) engine is designed to stabilise the mean fuel pressure into the rail and to track demanded pressure trajectories. By exploiting a simple control-oriented model describing the mean pressure dynamics in the rail, the control structure turns to be simple enough to be effectively implemented in commercial ECUs. Experimental results in a wide range of operating points confirm the effectiveness of the proposed control method to tame efficiently the mean value pressure dynamics of the plant showing a good accuracy and robustness with respect to unavoidable parameters uncertainties, unmodelled dynamics, and hidden coupling terms.

Adaptive ILC with an adaptive iterative learnign gain

International Nuclear Information System (INIS)

Ashraf, S.; Muhammad, E.

2008-01-01

This paper describes the design of an adaptive ILC (Iterative Learning Controller) with an iterative learning gain. The basic idea behind ILC is that the information obtained from one trial can be used to improve the control input for the next trial. This proposed scheme extends the idea further and suggests that the information obtained from one trial could also be used to improve control algorithm parameters (gain matrices). The scheme converges faster than the conventional ILC. This convergence and hence number of iterations has always been an issue with ILC. This scheme because of its simple mathematical structure can easily be implemented with lower memory and simpler hardware as opposed to other such adaptive schemes which are computationally expensive. (author)

Intrinsic gain modulation and adaptive neural coding.

Directory of Open Access Journals (Sweden)

Sungho Hong

2008-07-01

Full Text Available In many cases, the computation of a neural system can be reduced to a receptive field, or a set of linear filters, and a thresholding function, or gain curve, which determines the firing probability; this is known as a linear/nonlinear model. In some forms of sensory adaptation, these linear filters and gain curve adjust very rapidly to changes in the variance of a randomly varying driving input. An apparently similar but previously unrelated issue is the observation of gain control by background noise in cortical neurons: the slope of the firing rate versus current (f-I curve changes with the variance of background random input. Here, we show a direct correspondence between these two observations by relating variance-dependent changes in the gain of f-I curves to characteristics of the changing empirical linear/nonlinear model obtained by sampling. In the case that the underlying system is fixed, we derive relationships relating the change of the gain with respect to both mean and variance with the receptive fields derived from reverse correlation on a white noise stimulus. Using two conductance-based model neurons that display distinct gain modulation properties through a simple change in parameters, we show that coding properties of both these models quantitatively satisfy the predicted relationships. Our results describe how both variance-dependent gain modulation and adaptive neural computation result from intrinsic nonlinearity.

Changes in job strain and subsequent weight gain

DEFF Research Database (Denmark)

Vesterlund, Gitte Kingo; Keller, Amélie Cléo; Heitmann, Berit Lilienthal

2018-01-01

in 1999 between those who were rarely v. sometimes v. often busy in 1993 (P=0·03), with the largest weight gain in individuals with sustained high busyness in both years. Loss of influence between 1993 and 1999 was associated with larger subsequent weight gain than sustained high influence (P=0......Objective: Obesity as well as job strain is increasing, and job strain might contribute to weight gain. The objective of the current study was to examine associations between longitudinal alterations in the components of job strain and subsequent weight gain. Design: The study was designed...... as a prospective cohort study with three questionnaire surveys enabling measurement of job-strain alterations over 6 years and subsequent measurements of weight gain after further 10 years of follow-up. ANCOVA and trend analyses were conducted. Job demands were measured as job busyness and speed, and control...

Online Energy Management of City Cars with Multi-Objective Linear Parameter-Varying L2-Gain Control

Directory of Open Access Journals (Sweden)

Boe-Shong Hong

2015-09-01

Full Text Available This work aims at online regulating transient current out of the batteries of small-sized electric cars that transport people and goods around cities. In a city with heavy traffic, transient current dominates the energy economy and propulsion capability, which are in opposition to each other. In order to manage the trade-off between energy consumption per distance and propulsion capability in transience, the authors improve on previous work on multi-objective linear parameter-varying (LPV L2-gain control. The observer embedded into this multi-objective controller no longer assumes Kalman-filtering structure, and structural conservatism is thus removed. A full-spectrum set of experiments is performed. The results reveal that the feedback design significantly improves energy-motion management.

A Mathematical Model to Investigate Gain-Induced Oscillation in the ...

African Journals Online (AJOL)

cce

that increase in the gain of the baroreflex feedback loop controlling venous volume ... The existence of fluctuations in blood pressure has been known since the ...... Thus, young adults, with high gain and small D2, are in the unstable region,.

Employment, work hours and weight gain among middle-aged women.

Science.gov (United States)

Au, N; Hauck, K; Hollingsworth, B

2013-05-01

To investigate the influence of employment and work hours on weight gain and weight loss among middle-aged women. Quantile regression techniques were used to estimate the influence of employment and hours worked on percentage weight change over 2 years across the entire distribution of weight change in a cohort of middle-aged women. A range of controls was included in the models to isolate the effect of work status. A total of 9276 women aged 45-50 years at baseline who were present in both the 1996 and 1998 surveys of the Australian Longitudinal Study of Women's Health. The women were a representative sample of the Australian population. Being out of the labour force or unemployed was associated with lower weight gain and higher weight loss than being employed. The association was stronger at low to moderate levels of weight gain. Among employed women, working regular (35-40), long (41-48) or very long (49+) hours was associated with increasingly higher levels of weight gain compared with working part-time hours. The association was stronger for women with greater weight gain overall. The association between unemployment and weight change became insignificant when health status was controlled for. Employment was associated with more weight gain and less weight loss. Among the employed, working longer hours was associated with more weight gain, especially at the higher levels of weight gain where the health consequences are more serious. These findings suggest that as women work longer hours they are more likely to make lifestyle choices that are associated with weight gain.

Optomechanical transistor with mechanical gain

Science.gov (United States)

Zhang, X. Z.; Tian, Lin; Li, Yong

2018-04-01

We study an optomechanical transistor, where an input field can be transferred and amplified unidirectionally in a cyclic three-mode optomechanical system. In this system, the mechanical resonator is coupled simultaneously to two cavity modes. We show that it only requires a finite mechanical gain to achieve the nonreciprocal amplification. Here the nonreciprocity is caused by the phase difference between the linearized optomechanical couplings that breaks the time-reversal symmetry of this system. The amplification arises from the mechanical gain, which provides an effective phonon bath that pumps the mechanical mode coherently. This effect is analogous to the stimulated emission of atoms, where the probe field can be amplified when its frequency is in resonance with that of the anti-Stokes transition. We show that by choosing optimal parameters, this optomechanical transistor can reach perfect unidirectionality accompanied with strong amplification. In addition, the presence of the mechanical gain can result in ultralong delay in the phase of the probe field, which provides an alternative to controlling light transport in optomechanical systems.

A Sigma-Delta ADC with Decimation and Gain Control Function for a Bluetooth Receiver in 130 nm Digital CMOS

Directory of Open Access Journals (Sweden)

Koh Jinseok

2006-01-01

Full Text Available We present a discrete-time second-order multibit sigma-delta ADC that filters and decimates by two the input data samples. At the same time it provides gain control function in its input sampling stage. A 4-tap FIR switched capacitor (SC architecture was chosen for antialiasing filtering. The decimation-by-two function is realized using divided-by-two clock signals in the antialiasing filter. Antialiasing, gain control, and sampling functions are merged in the sampling network using SC techniques. This compact architecture allows operating the preceding blocks at twice the ADC's clock frequency, thus improving the noise performance of the wireless receiver channel and relaxing settling requirements of the analog building blocks. The presented approach has been validated and incorporated in a commercial single-chip Bluetooth radio realized in a 1.5 V 130 nm digital CMOS process. The measured antialiasing filtering shows better than 75 dB suppression at the folding frequency band edge. A 67 dB dynamic range was measured with a sampling frequency of 37.5MHz.

The role of a personalized dietary intervention in managing gestational weight gain: a prospective, controlled study in a low-risk antenatal population.

Science.gov (United States)

Di Carlo, Costantino; Iannotti, Giuseppina; Sparice, Stefania; Chiacchio, Maria Pia; Greco, Elena; Tommaselli, Giovanni Antonio; Nappi, Carmine

2014-04-01

To compare the efficacy of a personal dietary intervention on gestational weight gain control with a general intervention promoting healthy eating. Prospective, controlled study including 154 low-risk pregnant women randomly allocated to two groups: 77 receiving a personalized diet plan and a close follow-up by a dietician (intervention group), 77 receiving standard dietary care by means of a brochure on healthy eating during pregnancy (control group). Pre-pregnancy weight, gestational age, height, weight and BMI at baseline, weight at term, gestational age at delivery and newborn weight were recorded for all participants. The primary end-point was the difference in body weight between baseline and term. Secondary end-points were the difference in body weight between pre-pregnancy and term and in newborn weights. Maternal weight gain at term was significantly lower both as compared to pre-pregnancy weight (8.2 ± 4.0 vs. 13.4 ± 4.2 kg; p weight at baseline (7.7 ± 3.8 vs. 13.7 ± 4.3 kg; p weight between baseline and term and newborn weight was observed in both groups, but stronger in patients from the intervention group (intervention group R = 0.76, p weight gain in pregnant women.

A double-blind, placebo-controlled trial of sibutramine for clozapine-associated weight gain.

Science.gov (United States)

Henderson, D C; Fan, X; Copeland, P M; Borba, C P; Daley, T B; Nguyen, D D; Zhang, H; Hayden, D; Freudenreich, O; Cather, C; Evins, A E; Goff, D C

2007-02-01

This study sought to examine the effectiveness of sibutramine, a weight loss agent, on clozapine-associated weight gain. This was a 12-week double-blind, placebo controlled, randomized trial of sibutramine for weight loss in obese clozapine-treated schizophrenia or schizoaffective disorder subjects. Ten patients were enrolled into the placebo group and 11 patients into the sibutramine group. There were no significant baseline differences between the two groups on age, gender, education, ethnicity, diagnosis, weight, body mass index (BMI), and blood pressure. At week 12, there were no significant differences in changes in weight, BMI, abdominal and waist circumferences, Hba1c, fasting glucose, or cholesterol levels. Sibutramine treatment did not show significant weight loss compared with placebo in clozapine-treated patients with schizophrenia or schizoaffective disorder. Further research with a larger sample size and longer follow-up duration is warranted.

A Voltage Gain-Controlled Modified CFOA And Its Application in Electronically Tunable Four-Mode All-Pass Filter Design

OpenAIRE

Norbert Herencsar; Jaroslav Koton; Abhirup Lahiri; Bilgin Metin; Kamil Vrba

2012-01-01

This paper presents a new active building block (ABB) called voltage gain-controlled modified current feedback amplifier (VGC-MCFOA) based on bipolar junction transistor technology. The versatility of the new ABB is demonstrated in new first-order all-pass filter structure design employing single VGC-MCFOA, single grounded capacitor, and three resistors. Introduced circuit provides all four possible transfer functions at the same configuration, namely current-mode, transimpedance-mode, transa...

Effect of aerobic exercise training on maternal weight gain in ...

African Journals Online (AJOL)

BACKGROUND: Weight gains in pregnancy within the recommended guidelines are associated with healthy fetal and maternal outcomes; higher weight gains are associated with fetal macrosomia. This study was a systemic review of randomized controlled trials on the effect of aerobic training on maternal weight in ...

Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use.

Science.gov (United States)

Meshi, Dar; Morawetz, Carmen; Heekeren, Hauke R

2013-01-01

Our reputation is important to us; we've experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one's character) has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others' behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one's degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior.

Energy expenditure, spontaneous physical activity and with weight gain in kidney transplant recipients.

Science.gov (United States)

Heng, Anne-Elisabeth; Montaurier, Christophe; Cano, Noël; Caillot, Nicolas; Blot, A; Meunier, Nathalie; Pereira, Bruno; Marceau, Geoffroy; Sapin, Vincent; Jouve, Christelle; Boirie, Yves; Deteix, Patrice; Morio, Beatrice

2015-06-01

Alterations in energy metabolism could trigger weight gain after renal transplantation. Nineteen transplanted non-diabetic men, 53 ± 1.6 years old, receiving calcineurin inhibitors but no corticosteroids were studied. They were compared with nine healthy men matched for height, age and lean body mass. Daily energy expenditure and its components (sleeping, basal and absorptive metabolic rates) were analyzed for 24 h in calorimetric chambers and for 4 days in free living conditions using calibrated accelerometry. Other variables known to influence energy expenditure were assessed: body composition, physical activity, 4-day food intake, drug consumption, serum C-reactive protein, interleukin-6, thyroid and parathyroid hormones, and epinephrine. Transplant recipients who gained more than 5% body weight after transplantation (n = 11, +11.0 ± 1.5 kg) were compared with those who did not (n = 8) and with the controls. Weight gain compared with non-weight gain patients and controls exhibited higher fat mass without change in lean body mass. Daily, sleeping and resting energy expenditure adjusted for lean body mass was significantly higher in non-weight gain (167.1 ± 4.2 kJ/kg/lean body mass/24 h, P controls (146.1 ± 4.6). Weight gain compared with controls and non-weight gain subjects had lower free living physical activity and a higher consumption of antihypertensive drugs and β-blockers. After kidney transplantation, weight gain patients were characterized by lower adjusted energy expenditure, reduced spontaneous physical activity but a more sedentary life style and a trend toward a higher energy intake explaining the reason they gained weight. The nWG KTR had increased resting and sleeping EE which protected them from weight gain. Such hypermetabolism was also observed in 24-h EE measurements. By comparison with the nWG patients, the WG transplant recipients were characterized by higher β-blocker consumption. These data could be helpful in the prevention of weight

SiPM Gain Stabilization Studies for Adaptive Power Supply

CERN Document Server

AUTHOR|(CDS)2074257; Zalieckas, Justas; Cvach, Jaroslav; Kvasnicka, Jiri; Polak, Ivo

2016-01-01

We present herein gain stabilization studies of SiPMs using a climate chamber at CERN. We present results for four detectors not tested before, three from Hamamatsu and one from KETEK. Two of the Hamamatsu SiPMs are novel sensors with trenches that reduce cross talk. We use an improved readout system with a digital oscilloscope controlled with a dedicated LabView program. We improved and automized the analysis to deal with large datasets. We have measured the gain-versus-bias-voltage dependence at fixed temperature and gain-versus-temperature dependence at fixed bias voltage to determine the bias voltage dependence on temperature $V(T)$ for stable gain. We show that the gain remains stable to better than $\\pm 0.5\\%$ in the $20^\\circ \\rm C - 30^\\circ C$ temperature range if the bias voltage is properly adjusted with temperature.

Slow-light-enhanced gain in active photonic crystal waveguides

DEFF Research Database (Denmark)

Ek, Sara; Hansen, Per Lunnemann; Chen, Yaohui

2014-01-01

Passive photonic crystals have been shown to exhibit a multitude of interesting phenomena, including slow-light propagation in line-defect waveguides. It was suggested that by incorporating an active material in the waveguide, slow light could be used to enhance the effective gain of the material......, which would have interesting application prospects, for example enabling ultra-compact optical amplifiers for integration in photonic chips. Here we experi- mentally investigate the gain of a photonic crystal membrane structure with embedded quantum wells. We find that by solely changing the photonic...... crystal structural parameters, the maximum value of the gain coefficient can be increased compared with a ridge waveguide structure and at the same time the spectral position of the peak gain be controlled. The experimental results are in qualitative agreement with theory and show that gain values similar...

A High-Gain Reflex-Based Bidirectional DC Charger with Efficient Energy Recycling for Low-Voltage Battery Charging-Discharging Power Control

Directory of Open Access Journals (Sweden)

Ching-Ming Lai

2018-03-01

Full Text Available This study proposes a high-gain reflex-charging-based bidirectional DC charger (RC-BDC to enhance the battery charging efficiency of light electric vehicles (LEV in a DC-microgrid. The proposed charger topology consists of an unregulated level converter (ULC and a two-phase interleaved buck-boost charge-pump converter (IBCPC, which together provide low ripple and high voltage conversion ratio. As the high-gain RC-BDC charges, the LEV’s battery with reflex charging currents, high battery charging efficiency, and prolonged battery life cycles are achieved. This is possible due to the recovering of negative pulse energy of reflex charging currents to reduce charge dissipations within LEV’s batteries. Derivations of the operating principles of the high-gain RC-BDC, analyses of its topology, and the closed-loop control designs were presented. Simulations and experiments were implemented with battery voltage of 48 V and DC-bus voltage of 400 V for a 500 W prototype. The results verify the feasibility of the proposed concept and were compared with the typical constant-current/constant-voltage (CC/CV charger. The comparison shows that the proposed high gain RC-BDC improves battery charging speed and reduces the battery thermal deterioration effect by about 12.7% and 25%, respectively.

Operational gain : measuring the capture of genetic gain ...

African Journals Online (AJOL)

The concept of operational gain is more than the weighted average of the genetic quality of planted hectares, and encompasses tree breeding efficiencies, propagation efficiencies, matching of species and genotype to site, plant use efficiency and early measures of stand density and growth. To test the operational gain ...

Effect of Tactile-Kinesthetic Stimulation on Weight Gaining of Preterm Infants

Directory of Open Access Journals (Sweden)

Mahdi Basiry

2009-11-01

Full Text Available Background:The quality of life and standard of health care in a society is measured  by its preterm infants' mortality rate. The popularity and credibility of alternative treatment such as touch therapy may be effective in preterm and low birth weightinfants in order to increase their survival rate.The aim of this study was to determine the effect of touch intervention on the weight gain of preterm infants who were admitted to the Neonatal Intensive Care Unite(NICU. Methods:This study was a randomized controlled trial performed in NICU of  Emamreza hospital,Mashhad,Iran,from July 2007 to November 2007. There were two groups (the control group and the case group and one response variable (weight gain.Infants in the control group received routine nursing care. Infants in the case  group,in addition to the routine care,received stroking/passive limb movement therapy  for three 15 minute sessions per day for a 10 day period.Then weight gaining was compared between the two groups .  Results:The weight gain data was analyzed by SPSS software. Over the 10 day study period, the case group gained significantly more weight compared to the control  group (p(p<0.001(.Conclusion:The data suggest that stroking/passive limb movement can be an efficientand cost effective way of enhancing growth in stable preterm infants .

Gaining and sustaining schistosomiasis control

DEFF Research Database (Denmark)

Ezeamama, Amara E.; He, Chun-La; Shen, Ye

2016-01-01

BACKGROUND: The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was established in 2008 to answer strategic questions about schistosomiasis control. For programme managers, a high-priority question is: what are the most cost-effective strategies for delivering preventiv...

The Iran Sanctions Act (ISA)

Science.gov (United States)

2009-06-04

billion4 contract (September 1997) for Total SA of France and its partners, Gazprom of Russia and Petronas of Malaysia to develop phases 2 and 3 of the 25...companies. On July 12, 2008, Total and Petronas , the original South Pars investors, pulled out of a deal to develop a liquified natural gas (LNG...do not exceed the $20 million in one year threshold for ISA sanctionability. Since the Total/ Petronas /Gazprom project in 1998, no projects have

Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use

Directory of Open Access Journals (Sweden)

Dar eMeshi

2013-08-01

Full Text Available Our reputation is important to us; we’ve experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one’s character has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others’ behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one’s degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior.

MOS current gain cells with electronically variable gain and constant bandwidth

NARCIS (Netherlands)

Klumperink, Eric A.M.; Seevinck, Evert

1989-01-01

Two MOS current gain cells are proposed that provide linear amplification of currents supplied by several linear MOS V-I converters. The gain is electronically variable by a voltage or a current and can be made insensitive to temperature and IC processing. The gain cells have a constant

An Analysis Nomoto Gain and Norbin Parameter on Ship Turning Maneuver

Directory of Open Access Journals (Sweden)

Aulia Siti Aisjah

2010-05-01

Full Text Available First order approach of maneuvering ship model developed by Nomoto, that has commonly underpinned researchers on mathematical models of ship maneuvering, is employed by the present research in order to describe the results of Nomoto validation gain value from some type of ships. In this present study, the controls are designated using FLC, while the rules are derived from FLC; furthermore, the reference is the LQG/LTR. On the other pole, Norbin parameters are obtained under the bases of the gain and time constant output control response. Validation of Nomoto gain value is obtained through the calculation of the value of a constant gain, settling time of the first order response, and approach value toward damping ratio and natural frequency response of the system used to control the output of the second order pattern. Validation is employed on 20 types of ships with a length between 40-350 meters; as a result, it is figured out that at the Low Speed General Cargo ship, Mariner, RO/RO, and Barge Carrier have good maneuverability compared to the other 17 types of ships.

Feasibility of a controlled trial aiming to prevent excessive pregnancy-related weight gain in primary health care

Directory of Open Access Journals (Sweden)

Weiderpass Elisabete

2008-08-01

Full Text Available Abstract Background Excessive gestational weight gain and postpartum weight retention may predispose women to long-term overweight and other health problems. Intervention studies aiming at preventing excessive pregnancy-related weight gain are needed. The feasibility of implementing such a study protocol in primary health care setting was evaluated in this pilot study. Methods A non-randomized controlled trial was conducted in three intervention and three control maternity and child health clinics in primary health care in Finland. Altogether, 132 pregnant and 92 postpartum women and 23 public health nurses (PHN participated in the study. The intervention consisted of individual counselling on physical activity and diet at five routine visits to a PHN and of an option for supervised group exercise until 37 weeks' gestation or ten months postpartum. The control clinics continued their usual care. The components of the feasibility evaluation were 1 recruitment and participation, 2 completion of data collection, 3 realization of the intervention and 4 the public health nurses' experiences. Results 1 The recruitment rate was slower than expected and the recruitment period had to be prolonged from the initially planned three months to six months. The average participation rate of eligible women at study enrolment was 77% and the drop-out rate 15%. 2 In total, 99% of the data on weight, physical activity and diet and 96% of the blood samples were obtained. 3 In the intervention clinics, 98% of the counselling sessions were realized, their contents and average durations were as intended, 87% of participants regularly completed the weekly records for physical activity and diet, and the average participation percentage in the group exercise sessions was 45%. 4 The PHNs regarded the extra training as a major advantage and the high additional workload as a disadvantage of the study. Conclusion The study protocol was mostly feasible to implement, which

Training feed-forward neural networks with gain constraints

Science.gov (United States)

Hartman

2000-04-01

Inaccurate input-output gains (partial derivatives of outputs with respect to inputs) are common in neural network models when input variables are correlated or when data are incomplete or inaccurate. Accurate gains are essential for optimization, control, and other purposes. We develop and explore a method for training feedforward neural networks subject to inequality or equality-bound constraints on the gains of the learned mapping. Gain constraints are implemented as penalty terms added to the objective function, and training is done using gradient descent. Adaptive and robust procedures are devised for balancing the relative strengths of the various terms in the objective function, which is essential when the constraints are inconsistent with the data. The approach has the virtue that the model domain of validity can be extended via extrapolation training, which can dramatically improve generalization. The algorithm is demonstrated here on artificial and real-world problems with very good results and has been advantageously applied to dozens of models currently in commercial use.

Distributed cerebellar plasticity implements adaptable gain control in a manipulation task: a closed-loop robotic simulation

Directory of Open Access Journals (Sweden)

Jesus A Garrido Alcazar

2013-10-01

Full Text Available Adaptable gain regulation is at the core of the forward controller operation performed by the cerebro-cerebellar loops and it allows the intensity of motor acts to be finely tuned in a predictive manner. In order to learn and store information about body-object dynamics and to generate an internal model of movement, the cerebellum is thought to employ long-term synaptic plasticity. LTD at the PF-PC synapse has classically been assumed to subserve this function (Marr, 1969. However, this plasticity alone cannot account for the broad dynamic ranges and time scales of cerebellar adaptation. We therefore tested the role of plasticity distributed over multiple synaptic sites (Gao et al., 2012; Hansel et al., 2001 by generating an analog cerebellar model embedded into a control loop connected to a robotic simulator. The robot used a three-joint arm and performed repetitive fast manipulations with different masses along an 8-shape trajectory. In accordance with biological evidence, the cerebellum model was endowed with both LTD and LTP at the PF-PC, MF-DCN and PC-DCN synapses. This resulted in a network scheme whose effectiveness was extended considerably compared to one including just PF-PC synaptic plasticity. Indeed, the system including distributed plasticity reliably self-adapted to manipulate different masses and to learn the arm-object dynamics over a time course that included fast learning and consolidation, along the lines of what has been observed in behavioral tests. In particular, PF-PC plasticity operated as a time correlator between the actual input state and the system error, while MF-DCN and PC-DCN plasticity played a key role in generating the gain controller. This model suggests that distributed synaptic plasticity allows generation of the complex learning properties of the cerebellum. The incorporation of further plasticity mechanisms and of spiking signal processing will allow this concept to be extended in a more realistic

Correlates of motivation to prevent weight gain: a cross sectional survey

Directory of Open Access Journals (Sweden)

Breedveld Boudewijn

2005-03-01

Full Text Available Abstract Background This study is an application of the theory of planned behaviour (TPB with additional variables to predict the motivations to prevent weight gain. In addition, variations in measures across individuals classified into Precaution Adoption Process stages (PAPM-stages of behaviour change were investigated. Methods A cross-sectional survey among 979 non-obese Dutch adults aged 25–35 years was conducted. Multiple binary logistic regression analysis was conducted to assess the associations of Body Mass Index (BMI, demographic factors and psychosocial variables from the TPB with the intention to prevent weight gain. Differences in BMI, demographic and psychosocial factors between PAPM-stages were explored using one-way analysis of variance and chi-square tests. Results Eighty-five percent of respondents intended to prevent weight gain. Age, attitudes and risk perceptions related to weight gain were the strongest correlates of intention (age: OR = 1.12, 95%CI: 1.04–1.20; attitude OR = 7.91, 95%CI: 5.33–11.74; risk perception OR = 1.24, 95%CI: 1.11–1.38. Significant differences were detected between the PAPM-stages in almost all variables. Notably, perceived behavioural control was lowest among people who had decided to prevent weight gain. Conclusion Messages to influence attitudes towards the prevention of weight gain and risk perception may affect people who are not yet motivated to prevent weight gain. Interventions increasing people's perceived behavioural control in overcoming barriers to prevent weight gain may help people to act on their intentions.

Soft measures and incremental gains in mines; Mesures douces et gains incrementaux : mines

Energy Technology Data Exchange (ETDEWEB)

Laliberte, P. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Mining and Mineral Sciences Laboratories

2008-07-01

This paper presented a variety of measures that mine operators can adopt to save energy. Researchers at the CANMET Mining and Mineral Sciences Laboratories of Natural Resources Canada have conducted a joint study with Hydro-Quebec to investigate the impact of alternate energy technologies and control systems on energy savings. The impacts of a range of technologies were evaluated and rates of energy efficiency were compared. Technologies included hybrid vehicles; fuel cell-powered vehicles; automated ventilation control systems; heat recovery; compressed air; and electrical mining equipment. Energy profiles for various industrial applications were included. This paper also provided details of computerized simulations currently being conducted to estimate the potential incremental gains associated with the use of technology innovations in mining applications. 9 tabs., 3 figs.

Optical gain and gain suppression of quantum-well lasers with valence band mixing

International Nuclear Information System (INIS)

Ahn, D.; Chuang, S.L.

1990-01-01

The effects of valence band mixing on the nonlinear gains of quantum-well lasers are studied theoretically. The authors' analysis is based on the multiband effective-mass theory and the density matrix formalism with intraband relaxation taken into account. The gain and the gain-suppression coefficient of a quantum-well laser are calculated from the complex optical susceptibility obtained by the density matrix formulation with the theoretical dipole moments obtained from the multiband effective-mass theory. The calculated gain spectrum shows that there are remarkable differences (both in peak amplitude and spectral shape) between our model with valence band mixing and the conventional parabolic band model. The shape of the gain spectrum calculated by the authors' model becomes more symmetric due to intraband relaxation together with nonparabolic energy dispersions and is closer to the experimental observations when compared with the conventional method using the parabolic band model and the multiband effective-mass calculation without intraband relaxation. Both give quite asymmetric gain spectra. Optical intensity in the GaAs active region is estimated by solving rate equations for the stationary states with nonlinear gain suppression. The authors calculate the mode gain for the resonant mode including the gain suppression, which results in spectral hole burning of the gain spectrum

Gain scheduled linear quadratic control for quadcopter

Science.gov (United States)

Okasha, M.; Shah, J.; Fauzi, W.; Hanouf, Z.

2017-12-01

This study exploits the dynamics and control of quadcopters using Linear Quadratic Regulator (LQR) control approach. The quadcopter’s mathematical model is derived using the Newton-Euler method. It is a highly manoeuvrable, nonlinear, coupled with six degrees of freedom (DOF) model, which includes aerodynamics and detailed gyroscopic moments that are often ignored in many literatures. The linearized model is obtained and characterized by the heading angle (i.e. yaw angle) of the quadcopter. The adopted control approach utilizes LQR method to track several reference trajectories including circle and helix curves with significant variation in the yaw angle. The controller is modified to overcome difficulties related to the continuous changes in the operating points and eliminate chattering and discontinuity that is observed in the control input signal. Numerical non-linear simulations are performed using MATLAB and Simulink to illustrate to accuracy and effectiveness of the proposed controller.

PI and PID controller tuning rule design for processes with delay, to achieve constant gain and phase margins for all values of delay

OpenAIRE

O'Dwyer, Aidan

2001-01-01

This paper will discuss the design of PI and PID controller tuning rules to compensate processes with delay, that are modelled in a number of ways. The rules allow the achievement of constant gain and phase margins as the delay varies.

Focus on Russia

International Nuclear Information System (INIS)

Van Koningsbrugge, H.

2008-01-01

A few articles in this magazine focus on the developments and policies in Russia. The titles of some of the articles are 'Between state power and liberal reform' on the task of the new Russian president to find a new balance between government interference and market economy; 'Green light for green energy' on the willingness of the Russian government to stimulate renewable energy; 'Russian power play' on the role of Gazprom in the liberalization of the Russian power market; 'Gazprom's risky strategy' on it's pricing strategy

Low Voltage Current-Reused Pseudo-Differential Programmable Gain Amplifier

Science.gov (United States)

Nguyen, Huy-Hieu; Lee, Jeong-Seon; Lee, Sang-Gug

This paper reports a current-reused pseudo-differential (CRPD) programmable gain amplifier (PGA) that demonstrates small size, low power, wide band, low noise, and high linearity operation with 4 control bits. Implemented in 0.18um CMOS technology, the PGA shows the gain range from -9.9 to 8.3dB with gain error of less than ±0.38dB. The IIP3, P1dB, and smallest 3-dB bandwidth are 10.5 to 27dBm, -9 to 9.5dBm, and 250MHz, respectively. The PGA occupies the chip area of 0.04mm2 and consumes only 460 µA from a 1.2V supply.

78 FR 74125 - Agency Information Collection Activities; Comment Request; Measuring Educational Gain in the...

Science.gov (United States)

2013-12-10

...; Comment Request; Measuring Educational Gain in the National Reporting System for Adult Education AGENCY... Educational Gain in the National Reporting System for Adult Education. OMB Control Number: 1830-0567. Type of... tests to measure and report educational gain under the NRS. Dated: December 4, 2013. Tomakie Washington...

Random Photon Absorption Model Elucidates How Early Gain Control in Fly Photoreceptors Arises from Quantal Sampling

Science.gov (United States)

Song, Zhuoyi; Zhou, Yu; Juusola, Mikko

2016-01-01

Many diurnal photoreceptors encode vast real-world light changes effectively, but how this performance originates from photon sampling is unclear. A 4-module biophysically-realistic fly photoreceptor model, in which information capture is limited by the number of its sampling units (microvilli) and their photon-hit recovery time (refractoriness), can accurately simulate real recordings and their information content. However, sublinear summation in quantum bump production (quantum-gain-nonlinearity) may also cause adaptation by reducing the bump/photon gain when multiple photons hit the same microvillus simultaneously. Here, we use a Random Photon Absorption Model (RandPAM), which is the 1st module of the 4-module fly photoreceptor model, to quantify the contribution of quantum-gain-nonlinearity in light adaptation. We show how quantum-gain-nonlinearity already results from photon sampling alone. In the extreme case, when two or more simultaneous photon-hits reduce to a single sublinear value, quantum-gain-nonlinearity is preset before the phototransduction reactions adapt the quantum bump waveform. However, the contribution of quantum-gain-nonlinearity in light adaptation depends upon the likelihood of multi-photon-hits, which is strictly determined by the number of microvilli and light intensity. Specifically, its contribution to light-adaptation is marginal (≤ 1%) in fly photoreceptors with many thousands of microvilli, because the probability of simultaneous multi-photon-hits on any one microvillus is low even during daylight conditions. However, in cells with fewer sampling units, the impact of quantum-gain-nonlinearity increases with brightening light. PMID:27445779

Should I Gain Weight?

Science.gov (United States)

... Videos for Educators Search English Español Should I Gain Weight? KidsHealth / For Teens / Should I Gain Weight? ... something about it. Why Do People Want to Gain Weight? Some of the reasons people give for ...

Developmental gains in visuospatial memory predict gains in mathematics achievement.

Directory of Open Access Journals (Sweden)

Yaoran Li

Full Text Available Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4 were larger than gains in the capacity of the central executive (d = 1.6 that in turn were larger than gains in phonological memory span (d = 1.1. First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

Developmental gains in visuospatial memory predict gains in mathematics achievement.

Science.gov (United States)

Li, Yaoran; Geary, David C

2013-01-01

Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

Developmental Gains in Visuospatial Memory Predict Gains in Mathematics Achievement

Science.gov (United States)

Li, Yaoran; Geary, David C.

2013-01-01

Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning. PMID:23936154

Mutually-modulated cross-gain modulation and slow light

International Nuclear Information System (INIS)

Sternklar, Shmuel; Sarid, Eyal; Wart, Maxim; Granot, Er'el

2010-01-01

The interaction of pump and Stokes light in a Brillouin medium, where both beams are modulated, can be utilized for controlling the group velocity of the amplified Stokes (or depleted pump). The dependence of the group velocity for this mutually-modulated cross-gain modulation (MMXGM) technique on the Brillouin gain parameter is studied. A sharp transition to slow light occurs in the G 1 α/β≈1 regime, where G 1 is the Brillouin gain parameter, and α and β are the pump and Stokes modulation indices, respectively. A comparison of MMXGM slow light to the Brillouin dispersion-based slow-light technique reveals the fundamental differences between them. The formation of higher harmonics of the modulation frequency is also discussed. The theoretical predictions are experimentally corroborated and potential applications in fiber-based sensing and interferometry are discussed

Metformin for treatment of antipsychotic-induced weight gain: a randomized, placebo-controlled study.

Science.gov (United States)

Wang, Man; Tong, Jian-hua; Zhu, Gang; Liang, Guang-ming; Yan, Hong-fei; Wang, Xiu-zhen

2012-06-01

To evaluate the efficacy of metformin for treatment of antipsychotic-induced weight gain. Seventy-two patients with first-episode schizophrenia who gained more than 7% of their predrug weight were randomly assigned to receive 1000 mg/d of metformin or placebo in addition to their ongoing treatment for 12 weeks using a double-blind study design. The primary outcome was change in body weight. The secondary outcomes included changes in body mass index, fasting glucose and insulin, and insulin resistance index. Of the 72 patients who were randomly assigned, 66 (91.6%) completed treatments. The body weight, body mass index, fasting insulin and insulin resistance index decreased significantly in the metformin group, but increased in the placebo group during the 12-week follow-up period. Significantly more patients in the metformin group lost their baseline weight by more than 7%, which was the cutoff for clinically meaningful weight loss. Metformin was tolerated well by majority patients. Metformin was effective and safe in attenuating antipsychotic-induced weight gain and insulin resistance in first-episode schizophrenia patients. Patients displayed good adherence to metformin. Copyright © 2012 Elsevier B.V. All rights reserved.

Detective quantum efficiency gains compared with speed gains for hypersensitized astronomical plates

International Nuclear Information System (INIS)

Kaye, A.L.

1977-01-01

It is reasonable to assume that gains in detective quantum efficiency (DQE) are far better criteria for assessing the performance of hypersensitizing techniques than gains in speed. It is shown here that gains in speed can be misleading, for some methods of hypersensitization give plates of increased speed but reduced detective quantum efficiency. (author)

Regulation of Blood Glucose Concentration in Type 1 Diabetics Using Single Order Sliding Mode Control Combined with Fuzzy On-line Tunable Gain, a Simulation Study

OpenAIRE

Dinani, Soudabeh Taghian; Zekri, Maryam; Kamali, Marzieh

2015-01-01

Diabetes is considered as a global affecting disease with an increasing contribution to both mortality rate and cost damage in the society. Therefore, tight control of blood glucose levels has gained significant attention over the decades. This paper proposes a method for blood glucose level regulation in type 1 diabetics. The control strategy is based on combining the fuzzy logic theory and single order sliding mode control (SOSMC) to improve the properties of sliding mode control method and...

Preventing Weight Gain

Science.gov (United States)

... Local Programs Related Topics Diabetes Nutrition Preventing Weight Gain Language: English (US) Español (Spanish) Recommend on Facebook ... cancer. Choosing an Eating Plan to Prevent Weight Gain So, how do you choose a healthful eating ...

Could Reward-disturbances caused by antipsychotic medication lead to weight gain?

DEFF Research Database (Denmark)

Nielsen, Mette Ødegaard; Rostrup, Egill; Nørbak-Emig, Henrik

2014-01-01

BACKGROUND The reward system is known to be central to the regulation of appetite. Further, disturbances of the brain reward system are suggested to play an important role in the development of central psychopathological symptoms in schizophrenia. Antipsychotic medication partly acts by modulating...... the reward system and most antipsychotics cause some degree of weight gain. Recently, a relation between weight gain caused by one week of olanzapine treatment and change in reward signalling was found in healthy volunteers1. To our knowledge there are no previous studies examining how the effect...... of antipsychotic treatment on the reward system relate to weight gain in patients. METHODS 50 antipsychotic-naïve first-episode patients with schizophrenia and 40 healthy controls were included in the study at baseline. 38 patients and 31 healthy controls were re-examined after six weeks where patients were...

Development of Digital Hysteresis Current Control with PLL Loop Gain Compensation Strategy for PWM Inverters with Constant Switching Frequency

Directory of Open Access Journals (Sweden)

N. Belhaouchet

2008-03-01

Full Text Available Hysteresis current control is one of the simplest techniques used to control the magnitude and phase angle of motor current for motor drives systems. However, this technique presents several disadvantages such as operation at variable switching frequency which can reveal problems of filtering, interference between the phases in the case of the three-phase systems with insulated neutral connection or delta connection, and irregularity of the modulation pulses which especially causes an acoustic noise on the level of the machine for the high power drive. In this paper, a new technique is proposed for a variable-hysteresis-band controller based on dead beat control applied to three phase voltage source PWM inverters feeding AC motors. Its main aim is firstly ensure a constant switching frequency and secondly the synchronization of modulation pulses using the phase-locked-loop with loop gain compensation in order to ensure a better stability. The behavior of the proposed technique is verified by simulation.

Multimodal Pilot Behavior in Multi-Axis Tracking Tasks with Time-Varying Motion Cueing Gains

Science.gov (United States)

Zaal, P. M. T; Pool, D. M.

2014-01-01

In a large number of motion-base simulators, adaptive motion filters are utilized to maximize the use of the available motion envelope of the motion system. However, not much is known about how the time-varying characteristics of such adaptive filters affect pilots when performing manual aircraft control. This paper presents the results of a study investigating the effects of time-varying motion filter gains on pilot control behavior and performance. An experiment was performed in a motion-base simulator where participants performed a simultaneous roll and pitch tracking task, while the roll and/or pitch motion filter gains changed over time. Results indicate that performance increases over time with increasing motion gains. This increase is a result of a time-varying adaptation of pilots' equalization dynamics, characterized by increased visual and motion response gains and decreased visual lead time constants. Opposite trends are found for decreasing motion filter gains. Even though the trends in both controlled axes are found to be largely the same, effects are less significant in roll. In addition, results indicate minor cross-coupling effects between pitch and roll, where a cueing variation in one axis affects the behavior adopted in the other axis.

Interventions to reduce weight gain in schizophrenia.

Science.gov (United States)

Faulkner, G; Cohn, T; Remington, G

2007-01-24

Weight gain is common for people with schizophrenia and this has serious implications for health and well being. To determine the effects of both pharmacological (excluding medication switching) and non pharmacological strategies for reducing or preventing weight gain in people with schizophrenia. We searched key databases and the Cochrane Schizophrenia Group's trials register (April 2006), reference sections within relevant papers, hand searched key journals, and contacted the first author of each relevant study and other experts to collect further information. We included all clinical randomised controlled trials comparing any pharmacological or non pharmacological intervention for weight gain (diet and exercise counselling) with standard care or other treatments for people with schizophrenia or schizophrenia-like illnesses. We reliably selected, quality assessed and extracted data from studies. As weight is a continuous outcome measurement, weighted mean differences (WMD) of the change from baseline were calculated. The primary outcome measure was weight loss. Twenty-three randomised controlled trials met the inclusion criteria for this review. Five trials assessed a cognitive/behavioural intervention and eighteen assessed a pharmacological adjunct. In terms of prevention, two cognitive/behavioural trials showed significant treatment effect (mean weight change) at end of treatment (n=104, 2 RCTs, WMD -3.38 kg CI -4.2 to -2.0). Pharmacological adjunct treatments were significant with a modest prevention of weight gain (n=274, 6 RCTs, WMD - 1.16 kg CI -1.9 to -0.4). In terms of treatments for weight loss, we found significantly greater weight reduction in the cognitive behavioural intervention group (n=129, 3 RCTs, WMD -1.69 kg CI -2.8 to -0.6) compared with standard care. Modest weight loss can be achieved with selective pharmacological and non pharmacological interventions. However, interpretation is limited by the small number of studies, small sample size

Examination of Routine Use of Prenatal Weight Gain Charts as a Communication Tool for Providers.

Science.gov (United States)

Aguilera, Marijo; Sidebottom, Abbey C; McCool, Brigitte R

2017-10-01

Objectives In 2009 the IOM revised prenatal weight gain guidelines. The primary purpose of this pilot study was to assess if provider education and use of prenatal weight gain charts to track weight gain and counsel patients was associated with better patient and provider knowledge and communication about the guidelines. Methods A prospective non-randomized study conducted in four OB practices (two control, two intervention). Data sources included provider surveys (n = 16 intervention, 21 control), patient surveys (n = 332), and medical records. Intervention clinics received provider education on the IOM guidelines and used patient education materials and prenatal weight gain charts to track weight gain and as a counseling tool. Comparison clinics received no education and did not use the charts or patient education information. Results More patients at intervention clinics (92.3%) reported that a provider gave them advice about weight gain, compared to patients from comparison clinics (66.4%) (p gain (83.1 vs. 64.3%, p = 0.007). Intervention clinic patients were more likely to have knowledge of the guidelines indicated by 72.3% reporting a target weight gain amount within the guidelines versus 50.4% of comparison patients (p gain charts resulted in higher patient reported communication about weight gain from their provider, higher patient satisfaction with those discussions, and better knowledge of the appropriate target weight gain goals.

Metformin and berberine prevent olanzapine-induced weight gain in rats.

Directory of Open Access Journals (Sweden)

Yueshan Hu

Full Text Available Olanzapine is a first line medication for the treatment of schizophrenia, but it is also one of the atypical antipsychotics carrying the highest risk of weight gain. Metformin was reported to produce significant attenuation of antipsychotic-induced weight gain in patients, while the study of preventing olanzapine-induced weight gain in an animal model is absent. Berberine, an herbal alkaloid, was shown in our previous studies to prevent fat accumulation in vitro and in vivo. Utilizing a well-replicated rat model of olanzapine-induced weight gain, here we demonstrated that two weeks of metformin or berberine treatment significantly prevented the olanzapine-induced weight gain and white fat accumulation. Neither metformin nor berberine treatment demonstrated a significant inhibition of olanzapine-increased food intake. But interestingly, a significant loss of brown adipose tissue caused by olanzapine treatment was prevented by the addition of metformin or berberine. Our gene expression analysis also demonstrated that the weight gain prevention efficacy of metformin or berberine treatment was associated with changes in the expression of multiple key genes controlling energy expenditure. This study not only demonstrates a significant preventive efficacy of metformin and berberine treatment on olanzapine-induced weight gain in rats, but also suggests a potential mechanism of action for preventing olanzapine-reduced energy expenditure.

Stress effects on framed decisions: there are differences for gains and losses

Directory of Open Access Journals (Sweden)

Stephan ePabst

2013-10-01

Full Text Available Recent studies have shown that acute stress can lead to riskier decision making. Yet, the underlying mechanisms of the stress effects on decisions under risk remain poorly understood. To gain a better understanding of decision-making processes and potential strategy application under stress, we investigated decision making in pure gain and loss domains with unequal expected values across alternatives. We conducted an experimental study with a 2 × 2 design (stress vs. no stress and gain domain vs. loss domain. The Trier Social Stress Test (TSST was utilized to induce acute stress. Controls performed the placebo-TSST. To validate the stress response we measured salivary cortisol and alpha amylase concentrations. We used a modified version of the Game of Dice Task (GDT to assess decision-making performance in a gain and a loss domain. Results showed that non-stressed participants of the gain domain decided less risky compared to those of the loss domain. This behavior is in accordance with previous studies and indicates the stability of the framing effect in even more complex tasks with changing expected values across alternatives. Stress did not alter risk taking behavior in the gain domain. Yet, in the loss domain stressed participants decided less risky compared to controls. Additionally, the data support earlier findings of longer reaction times in loss compared to gain domains due to higher cognitive effort for loss-framed decisions. It is discussed that stress may lead to reduced amygdala activation, which has been found to reduce riskier decisions in a loss domain. With respect to earlier results of riskier decisions in tasks that unite both gain and loss domains, it is discussed whether stress leads to a stronger evaluation of high gains and a neglect of losses.

Stress effects on framed decisions: there are differences for gains and losses.

Science.gov (United States)

Pabst, Stephan; Brand, Matthias; Wolf, Oliver T

2013-01-01

Recent studies have shown that acute stress can lead to riskier decision making. Yet, the underlying mechanisms of the stress effects on decisions under risk remain poorly understood. To gain a better understanding of decision-making processes and potential strategy application under stress, we investigated decision making in pure gain and loss domains with unequal expected values (EVs) across alternatives. We conducted an experimental study with a 2 × 2 design (stress vs. no stress and gain domain vs. loss domain). The Trier Social Stress Test (TSST) was utilized to induce acute stress. Controls performed the placebo-TSST (p-TSST). To validate the stress response we measured salivary cortisol and alpha-amylase concentrations. We used a modified version of the Game of Dice Task (GDT) to assess decision-making performance in a gain and a loss domain. Results showed that non-stressed participants made less risky decisions in the gain domain compared to those of the loss domain. This behavior is in accordance with previous studies and indicates the stability of the framing effect in even more complex tasks with changing EVs across alternatives. Stress did not alter risk taking behavior in the gain domain. Yet, in the loss domain stressed participants made less risky decisions compared to controls. Additionally, the data support earlier findings of longer reaction times in loss compared to gain domains due to higher cognitive effort for loss-framed decisions. It is discussed that stress may lead to reduced amygdala activation, which has been found to reduce riskier decisions in a loss domain. With respect to earlier results of riskier decisions in tasks that unite both gain and loss domains, it is discussed whether stress leads to a stronger evaluation of high gains and a neglect of losses.

Effect of body weight gain on insulin sensitivity after retirement from exercise training

Science.gov (United States)

Dolkas, Constantine B.; Rodnick, Kenneth J.; Mondon, Carl E.

1990-01-01

The effect of the body-weight gain after retirement from an exercise-training program on the retained increase in insulin sensitivity elicited by the training was investigated in exercise-trained (ET) rats. Insulin sensitivity was assessed by oral glucose tolerance and insulin suppression tests immediately after training and during retirement. Results show that, compared with sedentary controls, exercise training enhanced insulin-induced glucose uptake, but the enhanced sensitivity was gradually lost with the end of running activity until after seven days of retirement, when it became equal to that of controls. This loss of enhanced sensitivity to insulin was associated with an accelerated gain in body weight beginning one day after the start of retirement. However, those animals that gained weight only at rates similar to those of control rats, retained their enhanced sensitivity to insulin.

Productivity gains by fertilisation in Eucalyptus urophylla clonal ...

African Journals Online (AJOL)

Productivity gains by fertilisation in Eucalyptus urophylla clonal plantations across gradients in site and stand conditions. ... The control plot may typically be a permanent plot of an inventory network, providing representative information for a company's decisionmaking. The paired twin-plot receives intensive management ...

Enhancing genetic gain in the era of molecular breeding.

Science.gov (United States)

Xu, Yunbi; Li, Ping; Zou, Cheng; Lu, Yanli; Xie, Chuanxiao; Zhang, Xuecai; Prasanna, Boddupalli M; Olsen, Michael S

2017-05-17

As one of the important concepts in conventional quantitative genetics and breeding, genetic gain can be defined as the amount of increase in performance that is achieved annually through artificial selection. To develop pro ducts that meet the increasing demand of mankind, especially for food and feed, in addition to various industrial uses, breeders are challenged to enhance the potential of genetic gain continuously, at ever higher rates, while they close the gaps that remain between the yield potential in breeders' demonstration trials and the actual yield in farmers' fields. Factors affecting genetic gain include genetic variation available in breeding materials, heritability for traits of interest, selection intensity, and the time required to complete a breeding cycle. Genetic gain can be improved through enhancing the potential and closing the gaps, which has been evolving and complemented with modern breeding techniques and platforms, mainly driven by molecular and genomic tools, combined with improved agronomic practice. Several key strategies are reviewed in this article. Favorable genetic variation can be unlocked and created through molecular and genomic approaches including mutation, gene mapping and discovery, and transgene and genome editing. Estimation of heritability can be improved by refining field experiments through well-controlled and precisely assayed environmental factors or envirotyping, particularly for understanding and controlling spatial heterogeneity at the field level. Selection intensity can be significantly heightened through improvements in the scale and precision of genotyping and phenotyping. The breeding cycle time can be shortened by accelerating breeding procedures through integrated breeding approaches such as marker-assisted selection and doubled haploid development. All the strategies can be integrated with other widely used conventional approaches in breeding programs to enhance genetic gain. More transdisciplinary

Influences of finite gain bandwidth on pulse propagation in parabolic fiber amplifiers with distributed gain profiles

International Nuclear Information System (INIS)

Zhao Jia-Sheng; Li Pan; Chen Xiao-Dong; Feng Su-Juan; Mao Qing-He

2012-01-01

The evolutions of the pulses propagating in decreasing and increasing gain distributed fiber amplifiers with finite gain bandwidths are investigated by simulations with the nonlinear Schrödinger equation. The results show that the parabolic pulse propagations in both the decreasing and the increasing gain amplifiers are restricted by the finite gain bandwidth. For a given input pulse, by choosing a small initial gain coefficient and gain variation rate, the whole gain for the pulse amplification limited by the gain bandwidth may be higher, which is helpful for the enhancement of the output linearly chirped pulse energy. Compared to the decreasing gain distributed fiber amplifier, the increasing gain distributed amplifier may be more conducive to suppress the pulse spectral broadening and increase the critical amplifier length for achieving a larger output linearly chirped pulse energy

High gain multigap avalanche detectors for Cerenkov ring imaging

Energy Technology Data Exchange (ETDEWEB)

Gilmore, R.S.; Lavender, W.M.; Leith, D.W.G.S.; Williams, S.H.

1980-10-01

We report on a continuing study of multigap parallel plate avalanche chambers, primarily as photoelectron detectors for use with Cerenkov ring imaging counters. By suitable control of the fields in successive gaps and by introducing screens to reduce photon feedback to the cathode the gain many be increased considerably. We have obtained gains in excess of 6 x 10/sup 7/ for photoelectrons with a good pulse height spectrum and expect to increase this further. We discuss the use of resistive anodes to give avalanche positions in two dimensions by charge division.

Gestational weight gain among minority adolescents predicts term birth weight.

Science.gov (United States)

Ekambaram, Maheswari; Irigoyen, Matilde; DeFreitas, Johelin; Rajbhandari, Sharina; Geaney, Jessica Lynn; Braitman, Leonard Edward

2018-03-07

In adolescents, there is limited evidence on the independent and additive effect of prepregnancy body mass index (BMI) and gestational weight gain on infant birth weight. Data also show that this effect may vary by race. We sought to examine the impact of maternal prepregnancy BMI and gestational weight gain on birth weight and risk of large for gestational age (LGA) in term newborns of minority adolescent mothers. This was a retrospective cohort study of 411 singleton live term infants born to mothers ≤ 18 years. Data were abstracted from electronic medical records. Gestational weight gain was related to infant birth weight (ρ = 0.36, P gain, gestational age and Hispanic ethnicity were independent predictors of birth weight, controlling for maternal age, BMI, parity, tobacco/drug use and preeclampsia. The probability of having an LGA infant increased with weight gain [adjusted odds ratio (aOR) 1.14, 95% confidence interval (CI) 1.07-1.21] but not with BMI. Mothers who gained weight in excess of 2009 Institute of Medicine (IOM) recommendations had a greater risk of having an LGA infant compared to those who gained within recommendations (aOR 5.7, 95% CI 1.6-19.5). Minority adolescents with greater gestational weight gain had infants with higher birth weight and greater risk of LGA; BMI was not associated with either outcome. Further studies are needed to examine the applicability of the 2009 BMI-specific IOM gestational weight gain recommendations to adolescents in minority populations.

Gestational Weight Gain and Breastfeeding Outcomes in Group Prenatal Care.

Science.gov (United States)

Brumley, Jessica; Cain, M Ashley; Stern, Marilyn; Louis, Judette M

2016-09-01

This study sought to examine the differences in pregnancy outcomes with a focus on gestational weight gain for women attending group prenatal care compared to standard individual prenatal care. A matched case-control study was conducted including 65 women who chose group care and 130 women who chose standard individual care. Women were matched based on prepregnancy body mass index (BMI) category, eligibility for midwifery care, and age within 5 years. Women choosing group prenatal care and women choosing standard individual care had similar gestational weight gain, birth weight, gestational age at birth, and mode of birth. Women choosing group prenatal care did have a significantly higher rate of exclusive breastfeeding at 6 weeks postpartum (odds ratio [OR], 4.07; 95% confidence interval [CI], 1.81-9.15; P care. Group prenatal care participation resulted in equivalent gestational weight gain as well as pregnancy outcomes as compared to standard individual care. Breastfeeding rates were improved for women choosing group prenatal care. Randomized controlled trials are needed in order to eliminate selection bias. © 2016 by the American College of Nurse-Midwives.

Sudden gains in Cognitive Therapy and Interpersonal Psychotherapy for adult depression.

Science.gov (United States)

Lemmens, Lotte H J M; DeRubeis, Robert J; Arntz, Arnoud; Peeters, Frenk P M L; Huibers, Marcus J H

2016-02-01

We examined the rates, baseline predictors and clinical impact of sudden gains in a randomized comparison of individual Cognitive Therapy (CT) and Interpersonal Psychotherapy (IPT) for adult depression. 117 depressed outpatients received 16-20 sessions of either CT or IPT. Session-by-session symptom severity was assessed using the BDI-II. Sudden gains were examined using the original criteria as defined by Tang and DeRubeis (1999b). Furthermore, we examined whether the duration of the between-session interval at which sudden gains were recorded affected the results. There were significantly more patients with sudden gains in CT (42.2%) as compared to IPT (24.5%). The difference appeared to be driven by the criterion representing the stability of the gain. No between-group differences were found with regard to the magnitude, timing and predictors of the gains. Those with sudden gains were less depressed at post-treatment and follow-up. After controlling for the duration of the between-session interval, the difference in rates between the two conditions became a non-significant trend. Other sudden gains characteristics were similar to those observed when allowing for longer intervals as well. The current study indicates differences in occurrence of sudden gains in two treatment modalities that overall showed similar results, which might reflect different mechanisms of change. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gain and loss learning differentially contribute to life financial outcomes.

Directory of Open Access Journals (Sweden)

Brian Knutson

Full Text Available Emerging findings imply that distinct neurobehavioral systems process gains and losses. This study investigated whether individual differences in gain learning and loss learning might contribute to different life financial outcomes (i.e., assets versus debt. In a community sample of healthy adults (n = 75, rapid learners had smaller debt-to-asset ratios overall. More specific analyses, however, revealed that those who learned rapidly about gains had more assets, while those who learned rapidly about losses had less debt. These distinct associations remained strong even after controlling for potential cognitive (e.g., intelligence, memory, and risk preferences and socioeconomic (e.g., age, sex, ethnicity, income, education confounds. Self-reported measures of assets and debt were additionally validated with credit report data in a subset of subjects. These findings support the notion that different gain and loss learning systems may exert a cumulative influence on distinct life financial outcomes.

Integrated Control Using the SOFFT Control Structure

Science.gov (United States)

Halyo, Nesim

1996-01-01

The need for integrated/constrained control systems has become clearer as advanced aircraft introduced new coupled subsystems such as new propulsion subsystems with thrust vectoring and new aerodynamic designs. In this study, we develop an integrated control design methodology which accomodates constraints among subsystem variables while using the Stochastic Optimal Feedforward/Feedback Control Technique (SOFFT) thus maintaining all the advantages of the SOFFT approach. The Integrated SOFFT Control methodology uses a centralized feedforward control and a constrained feedback control law. The control thus takes advantage of the known coupling among the subsystems while maintaining the identity of subsystems for validation purposes and the simplicity of the feedback law to understand the system response in complicated nonlinear scenarios. The Variable-Gain Output Feedback Control methodology (including constant gain output feedback) is extended to accommodate equality constraints. A gain computation algorithm is developed. The designer can set the cross-gains between two variables or subsystems to zero or another value and optimize the remaining gains subject to the constraint. An integrated control law is designed for a modified F-15 SMTD aircraft model with coupled airframe and propulsion subsystems using the Integrated SOFFT Control methodology to produce a set of desired flying qualities.

Maximum Wind Power Tracking of Doubly Fed Wind Turbine System Based on Adaptive Gain Second-Order Sliding Mode

Directory of Open Access Journals (Sweden)

Hongchang Sun

2018-01-01

Full Text Available This paper proposes an adaptive gain second-order sliding mode control strategy to track optimal electromagnetic torque and regulate reactive power of doubly fed wind turbine system. Firstly, wind turbine aerodynamic characteristics and doubly fed induction generator (DFIG modeling are presented. Then, electromagnetic torque error and reactive power error are chosen as sliding variables, and fixed gain super-twisting sliding mode control scheme is designed. Considering that uncertainty upper bound is unknown and is hard to be estimated in actual doubly fed wind turbine system, a gain scheduled law is proposed to compel control parameters variation according to uncertainty upper bound real-time. Adaptive gain second-order sliding mode rotor voltage control method is constructed in detail and finite time stability of doubly fed wind turbine control system is strictly proved. The superiority and robustness of the proposed control scheme are finally evaluated on a 1.5 MW DFIG wind turbine system.

Active rc filter permits easy trade-off of amplifier gain and sensitivity to gain

Science.gov (United States)

Kerwin, W. J.; Shaffer, C. V.

1968-01-01

Passive RC network was designed with zeros of transmission in the right half of the complex frequency plane in the feedback loop of a simple negative-gain amplifier. The proper positioning provides any desired trade-off between amplifier gain and sensitivity to amplifier gain.

Ultrasonic testing of canning tubes in stainless steel of the EL 4 reactor; Controle par ultrasons des tubes de gaine en acier inoxydable du reacteur EL 4

Energy Technology Data Exchange (ETDEWEB)

Prot, A; Monnier, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

From all the methods possible for controlling thin cans the one chosen, for numerous reasons, vas that making use of ultrasonic techniques. A method has been developed which should make it possible to carry out a rapid and efficient industrial control of canning tubes, The reasons for the choice of the ultrasonic method are given in detail, together with the principles of the method and the actual control parameters. In the present state of our research, it should be possible to control at least 50 000 tubes a year. Improvements brought about in the details of the control technique itself should make it possible to increase this rate considerably. (authors) [French] Parmi toutes les methodes possibles de controle des gaines minces, le procede retenu pour de multiples raisons a ete celui faisant appel a la technique des ultrasons. Une methode a ete mise au point qui doit permettre un controle industriel rapide et efficace des tubes de gaine. Sont exposes en detail, les raisons du choix de la methode par ultrasons, les principes de cette methode et les parametres du controle proprement dit. Dans l'etat actuel de nos etudes la cadence devrait permettre le controle de 50000 tubes par an au minimum. Des ameliorations de detail portant sur la technique de controle elle-meme, doivent permettre d'accelerer tres notablement cette cadence. (auteurs)

Interventions to reduce weight gain in schizophrenia

Science.gov (United States)

Faulkner, Guy; Cohn, Tony; Remington, Gary

2014-01-01

Background Weight gain is common for people with schizophrenia and this has serious implications for health and well being. Objectives To determine the effects of both pharmacological (excluding medication switching) and non pharmacological strategies for reducing or preventing weight gain in people with schizophrenia. Search methods We searched key databases and the Cochrane Schizophrenia Group’s trials register (April 2006), reference sections within relevant papers, hand searched key journals, and contacted the first author of each relevant study and other experts to collect further information. Selection criteria We included all clinical randomised controlled trials comparing any pharmacological or non pharmacological intervention for weight gain (diet and exercise counselling) with standard care or other treatments for people with schizophrenia or schizophrenia-like illnesses. Data collection and analysis We reliably selected, quality assessed and extracted data from studies. As weight is a continuous outcome measurement, weighted mean differences (WMD) of the change from baseline were calculated. The primary outcome measure was weight loss. Main results Twenty-three randomised controlled trials met the inclusion criteria for this review. Five trials assessed a cognitive/behavioural intervention and eighteen assessed a pharmacological adjunct. In terms of prevention, two cognitive/behavioural trials showed significant treatment effect (mean weight change) at end of treatment (n=104, 2 RCTs, WMD −3.38 kg CI −4.2 to −2.0). Pharmacological adjunct treatments were significant with a modest prevention of weight gain (n=274, 6 RCTs, WMD − 1.16 kg CI −1.9 to −0.4). In terms of treatments for weight loss, we found significantly greater weight reduction in the cognitive behavioural intervention group (n=129, 3 RCTs, WMD −1.69 kg CI −2.8 to −0.6) compared with standard care. Authors’ conclusions Modest weight loss can be achieved with selective

Weight Gain: A Possible Side Effect of All Antiretrovirals

Science.gov (United States)

Ricci, Elena; Menzaghi, Barbara; Orofino, Giancarlo; Passerini, Simone; Madeddu, Giordano; Martinelli, Canio Vito; De Socio, Giuseppe Vittorio; Squillace, Nicola; Rusconi, Stefano; Bonfanti, Paolo; Di Biagio, Antonio; Quirino, T; Bonfanti, P; Ricci, E; Bellacosa, C; Maggi, P; Calza, L; Abeli, C; Menzaghi, B; Celesia, B M; Grosso, C; Stagno, A; Vichi, F; Mazzotta, F; Martinelli, C; Penco, G; Cassola, G; Di Biagio, A; Taramasso, L; Nicolini, L A; Dentone, C; Molteni, C; Palvarini, L; Scalzini, A; Carenzi, L; Rizzardini, G; Valsecchi, L; Cordier, L; Rusconi, S; Colombo, V; Galli, M; Franzetti, M; De Socio, G V; Mazzotta, E; Parruti, G; Madeddu, G; Bagella, P; S. Mura, M; Libertone, R; Antinori, A; Di Giambenedetto, S; Orofino, G; Guastavigna, M; Caramell, P

2017-01-01

Abstract Weight gain and body mass index (BMI) increase are central issues in patients living with HIV who need to minimize the risk of metabolic disease. Information collected through the SCOLTA cohort revealed significant 1-year BMI increase in patients treated with dolutegravir (P = .004), raltegravir (P = .0004), elvitegravir (P = .004), darunavir (P = .0006), and rilpivirine (P = .029). BMI gain correlated with low baseline BMI (P = .002) and older age (P = .0007) in Centers for Disease Control and Prevention stages A/B, with lower BMI (P = .005) and CD4+ T-cell count (P = .007) at enrollment in stage C. PMID:29255735

Stability in high gain plasmas in DIII-D

International Nuclear Information System (INIS)

Lazarus, E.A.; Houlberg, W.A.; Murakami, M.; Wade, M.R.

1996-10-01

Fusion power gain has been increased by a factor of 3 in DIII-D plasmas through the use of strong discharge shaping and tailoring of the pressure and current density profiles. H-mode plasmas with weak or negative central magnetic shear are found to have neoclassical ion confinement throughout most of the plasma volume. Improved MHD stability is achieved by controlling the plasma pressure profile width. The highest fusion power gain Q (ratio of fusion power to input power) in deuterium plasmas was 0.0015, which extrapolates to an equivalent Q of 0.32 in a deuterium-tritium plasma and is similar to values achieved in tokamaks of larger size and magnetic fields

Circular polarization with crossed-planar undulators in high-gain FELs

CERN Document Server

Kim, K J K J

2000-01-01

We propose a crossed undulator configuration for a high-gain free-electron laser to allow versatile polarization control. This configuration consists of a long (saturation length) planar undulator, a dispersive section, and a short (a few gain lengths) planar undulator oriented perpendicular to the first one. In the first undulator, a radiation component linearly polarized in the x-direction is amplified to saturation. In the second undulator, the x-polarized component propagates freely, while a new component, polarized in the y-direction, is generated and reaches saturation in a few gain lengths. By adjusting the strength of the dispersive section, the relative phase of two radiation components can be adjusted to obtain a suitable polarization for the total radiation field, including the circular polarization. The operating principle of the high-gain crossed undulator, which is quite different from that of the crossed undulator for spontaneous radiation, is illustrated in terms of 1-D FEL theory.

A high gain wide dynamic range transimpedance amplifier for optical receivers

International Nuclear Information System (INIS)

Liu Lianxi; Zou Jiao; Liu Shubin; Niu Yue; Zhu Zhangming; Yang Yintang; En Yunfei

2014-01-01

As the front-end preamplifiers in optical receivers, transimpedance amplifiers (TIAs) are commonly required to have a high gain and low input noise to amplify the weak and susceptible input signal. At the same time, the TIAs should possess a wide dynamic range (DR) to prevent the circuit from becoming saturated by high input currents. Based on the above, this paper presents a CMOS transimpedance amplifier with high gain and a wide DR for 2.5 Gbit/s communications. The TIA proposed consists of a three-stage cascade pull push inverter, an automatic gain control circuit, and a shunt transistor controlled by the resistive divider. The inductive-series peaking technique is used to further extend the bandwidth. The TIA proposed displays a maximum transimpedance gain of 88.3 dBΩ with the −3 dB bandwidth of 1.8 GHz, exhibits an input current dynamic range from 100 nA to 10 mA. The output voltage noise is less than 48.23 nV/√Hz within the −3 dB bandwidth. The circuit is fabricated using an SMIC 0.18 μm 1P6M RFCMOS process and dissipates a dc power of 9.4 mW with 1.8 V supply voltage. (semiconductor integrated circuits)

Perceptions of low-income African-American mothers about excessive gestational weight gain.

Science.gov (United States)

Herring, Sharon J; Henry, Tasmia Q; Klotz, Alicia A; Foster, Gary D; Whitaker, Robert C

2012-12-01

A rising number of low-income African-American mothers gain more weight in pregnancy than is recommended, placing them at risk for poor maternal and fetal health outcomes. Little is known about the perceptions of mothers in this population that may influence excessive gestational weight gain. In 2010-2011, we conducted 4 focus groups with 31 low-income, pregnant African-Americans in Philadelphia. Two readers independently coded the focus group transcripts to identify recurrent themes. We identified 9 themes around perceptions that encouraged or discouraged high gestational weight gain. Mothers attributed high weight gain to eating more in pregnancy, which was the result of being hungrier and the belief that consuming more calories while pregnant was essential for babies' health. Family members, especially participants own mothers, strongly reinforced the need to "eat for two" to make a healthy baby. Mothers and their families recognized the link between poor fetal outcomes and low weight gains but not higher gains, and thus, most had a greater pre-occupation with too little food intake and weight gain rather than too much. Having physical symptoms from overeating and weight retention after previous pregnancies were factors that discouraged higher gains. Overall, low-income African-American mothers had more perceptions encouraging high gestational weight gain than discouraging it. Interventions to prevent excessive weight gain need to be sensitive to these perceptions. Messages that link guideline recommended weight gain to optimal infant outcomes and mothers' physical symptoms may be most effective for weight control.

Directional amplifier in an optomechanical system with optical gain

Science.gov (United States)

Jiang, Cheng; Song, L. N.; Li, Yong

2018-05-01

Directional amplifiers are crucial nonreciprocal devices in both classical and quantum information processing. Here we propose a scheme for realizing a directional amplifier between optical and microwave fields based on an optomechanical system with optical gain, where an active optical cavity and two passive microwave cavities are coupled to a common mechanical resonator via radiation pressure. The two passive cavities are coupled via hopping interaction to facilitate the directional amplification between the active and passive cavities. We obtain the condition of achieving optical directional amplification and find that the direction of amplification can be controlled by the phase differences between the effective optomechanical couplings. The effects of the gain rate of the active cavity and the effective coupling strengths on the maximum gain of the amplifier are discussed. We show that the noise added to this amplifier can be greatly suppressed in the large cooperativity limit.

Gain attenuation of gated framing camera

International Nuclear Information System (INIS)

Xiao Shali; Liu Shenye; Cao Zhurong; Li Hang; Zhang Haiying; Yuan Zheng; Wang Liwei

2009-01-01

The theoretic model of framing camera's gain attenuation is analyzed. The exponential attenuation curve of the gain along the pulse propagation time is simulated. An experiment to measure the coefficient of gain attenuation based on the gain attenuation theory is designed. Experiment result shows that the gain follows an exponential attenuation rule with a quotient of 0.0249 nm -1 , the attenuation coefficient of the pulse is 0.00356 mm -1 . The loss of the pulse propagation along the MCP stripline is the leading reason of gain attenuation. But in the figure of a single stripline, the gain dose not follow the rule of exponential attenuation completely, instead, there is a gain increase at the stripline bottom. That is caused by the reflection of the pulse. The reflectance is about 24.2%. Combining the experiment and theory, which design of the stripline MCP can improved the gain attenuation. (authors)

Compromised Weight Gain, Milk Intake, and Feeding Behavior in Breastfed Newborns of Depressive Mothers

OpenAIRE

Hart, Sybil L.; Jackson, Shera C.; Boylan, L. Mallory

2011-01-01

Objective To explore depressed mood in the breastfeeding dyad. Method N = 50 mothers of 12-day-olds reported depressed mood (EPDS) and anxiety (STAI), then were videotaped while breastfeeding. Infants were weighed before and after breastfeeding. Results An ANCOVA on weight gain, which controlled for infant age and birth weight, found EPDS inversely related to weight gain. Following a significant MANCOVA on infant biobehavioral measures, ANCOVAs which controlled for birth weight, age, hunger a...

Weight Gain during Pregnancy

Science.gov (United States)

... Global Map Premature Birth Report Cards Careers Archives Pregnancy Before or between pregnancies Nutrition, weight & fitness Prenatal ... fitness > Weight gain during pregnancy Weight gain during pregnancy E-mail to a friend Please fill in ...

Mode control in a high gain relativistic klystron amplifier with 3 GW output power

Science.gov (United States)

Wu, Yang; Xie, Hong-Quan; Xu, Zhou

2014-01-01

Higher mode excitation is very serious in the relativistic klystron amplifier, especially for the high gain relativistic amplifier working at tens of kilo-amperes. The mechanism of higher mode excitation is explored in the PIC simulation and it is shown that insufficient separation of adjacent cavities is the main cause of higher mode excitation. So RF lossy material mounted on the drift tube wall is adopted to suppress higher mode excitation. A high gain S-band relativistic klystron amplifier is designed for the beam current of 13 kA and the voltage of 1 MV. PIC simulation shows that the output power is 3.2 GW when the input power is only 2.8 kW.

Fetal Programming of Obesity: Maternal Obesity and Excessive Weight Gain

Directory of Open Access Journals (Sweden)

Seray Kabaran

2014-10-01

Full Text Available The prevalence of obesity is an increasing health problem throughout the world. Maternal pre-pregnancy weight, maternal nutrition and maternal weight gain are among the factors that can cause childhood obesity. Both maternal obesity and excessive weight gain increase the risks of excessive fetal weight gain and high birth weight. Rapid weight gain during fetal period leads to changes in the newborn body composition. Specifically, the increase in body fat ratio in the early periods is associated with an increased risk of obesity in the later periods. It was reported that over-nutrition during fetal period could cause excessive food intake during postpartum period as a result of metabolic programming. By influencing the fetal metabolism and tissue development, maternal obesity and excessive weight gain change the amounts of nutrients and metabolites that pass to the fetus, thus causing excessive fetal weight gain which in turn increases the risk of obesity. Fetal over-nutrition and excessive weight gain cause permanent metabolic and physiologic changes in developing organs. While mechanisms that affect these organs are not fully understood, it is thought that the changes may occur as a result of the changes in fetal energy metabolism, appetite control, neuroendocrine functions, adipose tissue mass, epigenetic mechanisms and gene expression. In this review article, the effects of maternal body weight and weight gain on fetal development, newborn birth weight and risk of obesity were evaluated, and additionally potential mechanisms that can explain the effects of fetal over-nutrition on the risk of obesity were investigated [TAF Prev Med Bull 2014; 13(5.000: 427-434

Superluminal propagation in a poly-chromatically driven gain assisted four-level N-type atomic system

International Nuclear Information System (INIS)

Bacha, Bakht Amin; Ahmad, Iftikhar; Ullah, Arif; Ali, Hazrat

2013-01-01

We investigate the behavior of light propagation in an N-type four-level gain assisted model (Agarwal and Dasgupta 2004 Phys. Rev. A 70 023802) under poly-chromatic pump fields. The system exhibits interesting results of multiple controllable pairs of the gain doublet profile with changes in the intensity of the control field. We observe multiple anomalous dispersive regions for superluminal propagation in the medium. A negative group velocity of −37.50 m s −1 with a negative time delay of −8 ms is observed between each gain doublet in anomalous dispersive regions. This generalized model and its predictions can be tested with existing experimental setups. (paper)

History of Smoking and Postcessation Weight Gain among Weight Loss Surgery Candidates

Science.gov (United States)

Levine, Michele D.; Kalarchian, Melissa A.; Courcoulas, Anita P.; Wisinski, Meghan S.C.; Marcus, Marsha D.

2007-01-01

Smoking cessation often results in weight gain. Although smoking cessation frequently is recommended to patients presenting for weight loss surgery (WLS), the relationship between smoking cessation and weight gain among WLS candidates is poorly understood. Thus, we sought to document the history and prevalence of smoking and smoking-related weight gain among WLS candidates. Subjects (N = 67) presenting for bariatric surgery provided demographic information, were interviewed about smoking, and weighed and measured prior to operation. Sixty-seven percent of patients reported a lifetime history of smoking, and 26.9% were current smokers. Among lifetime smokers who had attempted to quit, the average maximum amount of weight gained following smoking cessation was 28.1 pounds, but there was wide variability in postcessation weight gain. These data suggest that smoking among candidates for bariatric surgery is prevalent, and that previous cessation attempts were associated with considerable weight gain. Because patients often receive recommendations to quit smoking and lose weight prior to surgery, additional information on the impact of presurgical smoking cessation on long-tem weight control in this population is needed. PMID:17408868

Association between maternal nutritional status of pre pregnancy, gestational weight gain and preterm birth.

Science.gov (United States)

Xinxo, Sonela; Bimbashi, Astrit; Z Kakarriqi, Eduard; Zaimi, Edmond

2013-01-01

Maternal nutritional status of pre pregnancy and gestational weight gain affects the preterm birth. The association between maternal nutritional status of pre pregnancy and preterm birth appears to be complex and varied by studies from different countries, thus this association between the gestational weight gain and preterm birth is more consolidated. The study aims to determine any association between the pre pregnancy maternal nutritional status, gestational weight gain and the preterm birth rate in the Albanian context. In case control study, we analyzed women who have delivered in obstetric institutions in Tirana during the year 2012. Body mass index and gestational weight gain of 150 women who had a preterm delivery were compared with those of 150 matched control women who had a normal delivery regarding the gestation age. The self-reported pre pregnancy weight, height, gestational weight gain, age, education and parity are collected through a structured questioner. The body mass index and gestational weight gain are categorized based on the Institute of Medicine recommendation. The multiple logistic regression is used to measure the association between the nutritional status of pre pregnancy and gestational weight gain and the preterm birth rate. The women which have a underweight status or obese of pre pregnancy are more likely to have a preterm birth compared to the women of a normal pre-pregnancy nutritional status (respectively OR =2.7 and 4.3 pnutritional status and gestational weight gain affects the risk for preterm birth. Pre-pregnancy and gestation nutritional assessments should be part of routine prenatal visits.

Numerical study on the selective excitation of Helmholtz-Gauss beams in end-pumped solid-state digital lasers with the control of the laser gain transverse position provided by off-axis end pumping

Science.gov (United States)

Tsai, Ko-Fan; Chu, Shu-Chun

2018-03-01

This study proposes a complete and unified method for selective excitation of any specified nearly nondiffracting Helmholtz-Gauss (HzG) beam in end-pumped solid-state digital lasers. Four types of the HzG beams: cosine-Gauss beams, Bessel-Gauss beams, Mathieu-Gauss beams, and, in particular, parabolic-Gauss beams are successfully demonstrated to be generated with the proposed methods. To the best of the authors’ knowledge, parabolic-Gauss beams have not yet been directly generated from any kind of laser system. The numerical results of this study show that one can successfully achieve any lasing HzG beams directly from the solid-state digital lasers with only added control of the laser gain transverse position provided by off-axis end pumping. This study also presents a practical digital laser set-up for easily manipulating off-axis pumping in order to achieve the control of the laser gain transverse gain position in digital lasers. The reported results in this study provide advancement of digital lasers in dynamically generating nondiffracting beams. The control of the digital laser cavity gain position creates the possibility of achieving real-time selection of more laser modes in digital lasers, and it is worth further investigation in the future.

All-optical pulse data generation in a semiconductor optical amplifier gain controlled by a reshaped optical clock injection

Science.gov (United States)

Lin, Gong-Ru; Chang, Yung-Cheng; Yu, Kun-Chieh

2006-05-01

Wavelength-maintained all-optical pulse data pattern transformation based on a modified cross-gain-modulation architecture in a strongly gain-depleted semiconductor optical amplifier (SOA) is investigated. Under a backward dark-optical-comb injection with 70% duty-cycle reshaping from the received data clock at 10GHz, the incoming optical data stream is transformed into a pulse data stream with duty cycle, rms timing jitter, and conversion gain of 15%, 4ps, and 3dB, respectively. The high-pass filtering effect of the gain-saturated SOA greatly improves the extinction ratio of data stream by 8dB and reduces its bit error rate to 10-12 at -18dBm.

Adherence to self-monitoring via interactive voice response technology in an eHealth intervention targeting weight gain prevention among Black women: randomized controlled trial.

Science.gov (United States)

Steinberg, Dori M; Levine, Erica L; Lane, Ilana; Askew, Sandy; Foley, Perry B; Puleo, Elaine; Bennett, Gary G

2014-04-29

eHealth interventions are effective for weight control and have the potential for broad reach. Little is known about the use of interactive voice response (IVR) technology for self-monitoring in weight control interventions, particularly among populations disproportionately affected by obesity. This analysis sought to examine patterns and predictors of IVR self-monitoring adherence and the association between adherence and weight change among low-income black women enrolled in a weight gain prevention intervention. The Shape Program was a randomized controlled trial comparing a 12-month eHealth behavioral weight gain prevention intervention to usual care among overweight and obese black women in the primary care setting. Intervention participants (n=91) used IVR technology to self-monitor behavior change goals (eg, no sugary drinks, 10,000 steps per day) via weekly IVR calls. Weight data were collected in clinic at baseline, 6, and 12 months. Self-monitoring data was stored in a study database and adherence was operationalized as the percent of weeks with a successful IVR call. Over 12 months, the average IVR completion rate was 71.6% (SD 28.1) and 52% (47/91) had an IVR completion rate ≥80%. At 12 months, IVR call completion was significantly correlated with weight loss (r =-.22; P=.04) and participants with an IVR completion rate ≥80% had significantly greater weight loss compared to those with an IVR completion rate self-monitoring. Adherence to IVR self-monitoring was high among socioeconomically disadvantaged black women enrolled in a weight gain prevention intervention. Higher adherence to IVR self-monitoring was also associated with greater weight change. IVR is an effective and useful tool to promote self-monitoring and has the potential for widespread use and long-term sustainability. Clinicaltrials.gov NCT00938535; http://www.clinicaltrials.gov/ct2/show/NCT00938535.

Tuning gain and bandwidth of traveling wave tubes using metamaterial beam-wave interaction structures

International Nuclear Information System (INIS)

Lipton, Robert; Polizzi, Anthony

2014-01-01

We employ metamaterial beam-wave interaction structures for tuning the gain and bandwidth of short traveling wave tubes. The interaction structures are made from metal rings of uniform cross section, which are periodically deployed along the length of the traveling wave tube. The aspect ratio of the ring cross sections is adjusted to control both gain and bandwidth. The frequency of operation is controlled by the filling fraction of the ring cross section with respect to the size of the period cell.

A Voltage Gain-Controlled Modified CFOA And Its Application in Electronically Tunable Four-Mode All-Pass Filter Design

Directory of Open Access Journals (Sweden)

Norbert Herencsar

2012-07-01

Full Text Available This paper presents a new active building block (ABB called voltage gain-controlled modified current feedback amplifier (VGC-MCFOA based on bipolar junction transistor technology. The versatility of the new ABB is demonstrated in new first-order all-pass filter structure design employing single VGC-MCFOA, single grounded capacitor, and three resistors. Introduced circuit provides all four possible transfer functions at the same configuration, namely current-mode, transimpedance-mode, transadmittance-mode, and voltage-mode. The pole frequency of the circuit can be easily tuned by means of DC bias currents. The theoretical results are verified by SPICE simulations based on bipolar transistor arrays AT&T ALA400-CBIC-R process parameters.

Leading Gainful Employment Metric Reporting

Science.gov (United States)

Powers, Kristina; MacPherson, Derek

2016-01-01

This chapter will address the importance of intercampus involvement in reporting of gainful employment student-level data that will be used in the calculation of gainful employment metrics by the U.S. Department of Education. The authors will discuss why building relationships within the institution is critical for effective gainful employment…

Can Beta Blockers Cause Weight Gain?

Science.gov (United States)

... cause weight gain? Can beta blockers cause weight gain? Answers from Sheldon G. Sheps, M.D. Yes. Weight gain can occur as a side effect of some ... and metoprolol (Lopressor, Toprol-XL). The average weight gain is about 2.6 pounds (about 1.2 ...

Amplified spontaneous emission spectrum and gain characteristic of a two-electrode semiconductor optical amplifier

International Nuclear Information System (INIS)

Wang Hanchao; Huang Lirong; Shi Zhongwei

2011-01-01

A two-electrode multi-quantum-well semiconductor optical amplifier is designed and fabricated. The amplified spontaneous emission (ASE) spectrum and gain were measured and analyzed. It is shown that the ASE spectrum and gain characteristic are greatly influencedby the distribution of the injection current density. By changing the injection current density of two electrodes, the full width at half maximum, peak wavelength, peak power of the ASE spectrum and the gain characteristic can be easily controlled. (semiconductor devices)

Generalized gain scheduling for deloaded wind turbine operation

DEFF Research Database (Denmark)

Venne, Philippe; Guillaud, X.; Teodorescu, Remus

2010-01-01

to regulate both power production and rotor speed under any wind speed conditions. In this paper, a novel controller for deloaded wind turbine operation is presented. This controller is made possible by a Cp table inversion procedure allowing generalized gain scheduling for linearization of the pitch response......The ability to produce less power than what is available from a wind source, a condition known as deloaded operation, is needed for a wind turbine to reproduce synchronous machine behavior in terms of inertial response and frequency droop regulation. Deloaded operation requires the ability...

Estimating the potential gains from mergers

DEFF Research Database (Denmark)

Bogetoft, Peter; Wang, Dexiang

2005-01-01

We introduce simple production economic models to estimate the potential gains from mergers. We decompose the gains into technical ef¿ciency, size (scale) and harmony (mix) gains, and we discuss alternative ways to capture these gains. We propose to approximate the production processes using...... the non-parametric. Data Envelopment Analysis (DEA) approach, and we use the resulting operational approach to estimate the potential gains from merging agricultural extension of¿ces in Denmark....

Intelligent control of diesel generators using gain-scheduling

DEFF Research Database (Denmark)

Mai, Christian; Jepsen, Kasper; Yang, Zhenyu

2014-01-01

The development of an intelligent control solution for a wide range of diesel generators is discussed. Compared with most existing solutions, the advantages of the proposed solution lie in two folds: (i) The proposed control has the plug-and-play capability which is reflected by an automatic...... recognition procedure when it is plugged into a specific diesel generator, such that some extensive manual-tuning of the installed controller can be significantly reduced; (ii) The proposed control has an real-time adaptability by using the online external load estimation, such that the integrated system can...... keep a consistent performance for a wide range of operating conditions. Technically, a general nonlinear dynamic model is firstly developed based on fundamental principles of diesel generators. Then, the system parameters of this model can be identified experimentally or partially retrieved from...

A CMOS variable gain amplifier for PHENIX electromagnetic calorimeter and RICH energy measurements

Energy Technology Data Exchange (ETDEWEB)

Wintenberg, A.L.; Simpson, M.L.; Young, G.R. [Oak Ridge National Lab., TN (United States); Palmer, R.L.; Moscone, C.G.; Jackson, R.G. [Tennessee Univ., Knoxville, TN (United States)

1996-12-31

A variable gain amplifier (VGA) has been developed equalizing the gains of integrating amplifier channels used with multiple photomultiplier tubes operating from common high-voltage supplies. The PHENIX lead-scintillator electromagnetic calorimeter will operate in that manner, and gain equalization is needed to preserve the dynamic range of the analog memory and ADC following the integrating amplifier. The VGA is also needed for matching energy channel gains prior to forming analog sums for trigger purposes. The gain of the VGA is variable over a 3:1 range using a 5-bit digital control, and the risetime is held between 15 and 23 ns using switched compensation in the VGA. An additional feature is gated baseline restoration. Details of the design and results from several prototype devices fabricated in 1.2-{mu}m Orbit CMOS are presented.

Factorization and the synthesis of optimal feedback gains for distributed parameter systems

Science.gov (United States)

Milman, Mark H.; Scheid, Robert E.

1990-01-01

An approach based on Volterra factorization leads to a new methodology for the analysis and synthesis of the optimal feedback gain in the finite-time linear quadratic control problem for distributed parameter systems. The approach circumvents the need for solving and analyzing Riccati equations and provides a more transparent connection between the system dynamics and the optimal gain. The general results are further extended and specialized for the case where the underlying state is characterized by autonomous differential-delay dynamics. Numerical examples are given to illustrate the second-order convergence rate that is derived for an approximation scheme for the optimal feedback gain in the differential-delay problem.

Insulin-associated weight gain in obese type 2 diabetes mellitus patients: What can be done?

Science.gov (United States)

Brown, Adrian; Guess, Nicola; Dornhorst, Anne; Taheri, Shahrad; Frost, Gary

2017-12-01

Insulin therapy (IT) is initiated for patients with type 2 diabetes mellitus when glycaemic targets are not met with diet and other hypoglycaemic agents. The initiation of IT improves glycaemic control and reduces the risk of microvascular complications. There is, however, an associated weight gain following IT, which may adversely affect diabetic and cardiovascular morbidity and mortality. A 3 to 9 kg insulin-associated weight gain (IAWG) is reported to occur in the first year of initiating IT, predominantly caused by adipose tissue. The potential causes for this weight gain include an increase in energy intake linked to a fear of hypoglycaemia, a reduction in glycosuria, catch-up weight, and central effects on weight and appetite regulation. Patients with type 2 diabetes who are receiving IT often have multiple co-morbidities, including obesity, that are exacerbated by weight gain, making the management of their diabetes and obesity challenging. There are several treatment strategies for patients with type 2 diabetes, who require IT, that attenuate weight gain, help improve glycaemic control, and help promote body weight homeostasis. This review addresses the effects of insulin initiation and intensification on IAWG, and explores its potential underlying mechanisms, the predictors for this weight gain, and the available treatment options for managing and limiting weight gain. © 2017 John Wiley & Sons Ltd.

Effects of lifestyle intervention in obese pregnant women on gestational weight gain and mental health: a randomized controlled trial.

Science.gov (United States)

Bogaerts, A F L; Devlieger, R; Nuyts, E; Witters, I; Gyselaers, W; Van den Bergh, B R H

2013-06-01

Lifestyle intervention could help obese pregnant women to limit their weight gain during pregnancy and improve their psychological comfort, but has not yet been evaluated in randomized controlled trials. We evaluated whether a targeted antenatal lifestyle intervention programme for obese pregnant women influences gestational weight gain (GWG) and levels of anxiety or depressed mood. This study used a longitudinal interventional design. Of the 235 eligible obese pregnant women, 205 (mean age (years): 29±4.5; body mass index (BMI, kg m(-)(2)): 34.7±4.6) were randomized to a control group, a brochure group receiving written information on healthy lifestyle and an experimental group receiving an additional four antenatal lifestyle intervention sessions by a midwife trained in motivational lifestyle intervention. Anxiety (State and Trait Anxiety Inventory) and feelings of depression (Edinburgh Depression Scale) were measured during the first, second and third trimesters of pregnancy. Socio-demographical, behavioural, psychological and medical variables were used for controlling and correcting outcome variables. We found a significant reduction of GWG in the brochure (9.5 kg) and lifestyle intervention (10.6 kg) group compared with normal care group (13.5 kg) (P=0.007). Furthermore, levels of anxiety significantly decreased in the lifestyle intervention group and increased in the normal care group during pregnancy (P=0.02); no differences were demonstrated in the brochure group. Pre-pregnancy BMI was positively related to levels of anxiety. Obese pregnant women who stopped smoking recently showed a significant higher GWG (β=3.04; P=0.01); those with concurrent gestational diabetes mellitus (GDM) (β=3.54; P=0.03) and those who consumed alcohol on a regular base (β=3.69; P=0.04) showed significant higher levels of state anxiety. No differences in depressed mood or obstetrical/neonatal outcomes were observed between the three groups. A targeted lifestyle

Experience gained in the process of the variable mass heat flow control implemented in the district heat supply system of the city of Gyor

Energy Technology Data Exchange (ETDEWEB)

Nagy, F.; Milanovich, L.; Lelek, J.; Kekk, I. [District Heating LTD. of Gyor (Hungary)

1996-11-01

The district heating system of the city of Gyor is fed from a hot water boiler plant. The total heat demand for 23,000 residential homes and several public facilities is 260 MW. The variable mass flow control was implemented in 1991 through 1992. Design, preparatory job and the majority of implementation was carried out without external involvement. The paper presents historical background and brief project presentation which is followed by comparative presentation of the variable mass flow control and constant mass flow control. This comparative survey has been conducted on the basis of operating data for 1993 and those for 1988. In the conclusion the gained experience is summarized.

Systematic review of antiretroviral-associated lipodystrophy: lipoatrophy, but not central fat gain, is an antiretroviral adverse drug reaction.

Directory of Open Access Journals (Sweden)

Reneé de Waal

Full Text Available BACKGROUND: Lipoatrophy and/or central fat gain are observed frequently in patients on antiretroviral therapy (ART. Both are assumed to be antiretroviral adverse drug reactions. METHODS: We conducted a systematic review to determine whether fat loss or gain was more common in HIV-infected patients on ART than in uninfected controls; was associated with specific antiretrovirals; and would reverse after switching antiretrovirals. RESULTS: Twenty-seven studies met our inclusion criteria. One cohort study reported more lipoatrophy, less subcutaneous fat gain, but no difference in central fat gain in HIV-infected patients on ART than in controls. Randomised controlled trials (RCTs showed more limb fat loss (or less fat gain with the following regimens: stavudine (versus other nucleoside reverse transcriptase inhibitors (NRTIs; efavirenz (versus protease inhibitors (PIs; and NRTI-containing (versus NRTI-sparing. RCTs showed increased subcutaneous fat after switching to NRTI-sparing regimens or from stavudine/zidovudine to abacavir/tenofovir. There were no significant between-group differences in trunk and/or visceral fat gain in RCTs of various regimens, but results from efavirenz versus PI regimens were inconsistent. There was no significant between-group differences in central fat gain in RCTs switched to NRTI-sparing regimens, or from PI-containing regimens. CONCLUSIONS: There is clear evidence of a causal relationship between NRTIs (especially thymidine analogues and lipoatrophy, with concomitant PIs possibly having an ameliorating effect or efavirenz causing additive toxicity. By contrast, central fat gain appears to be a consequence of treating HIV infection, because it is not different from controls, is not linked to any antiretroviral class, and doesn't improve on switching.

A gain-coefficient switched Alexandrite laser

International Nuclear Information System (INIS)

Lee, Chris J; Van der Slot, Peter J M; Boller, Klaus-J

2013-01-01

We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.

Study of gain-coupled distributed feedback laser based on high order surface gain-coupled gratings

Science.gov (United States)

Gao, Feng; Qin, Li; Chen, Yongyi; Jia, Peng; Chen, Chao; Cheng, LiWen; Chen, Hong; Liang, Lei; Zeng, Yugang; Zhang, Xing; Wu, Hao; Ning, Yongqiang; Wang, Lijun

2018-03-01

Single-longitudinal-mode, gain-coupled distributed feedback (DFB) lasers based on high order surface gain-coupled gratings are achieved. Periodic surface metal p-contacts with insulated grooves realize gain-coupled mechanism. To enhance gain contrast in the quantum wells without the introduction of effective index-coupled effect, groove length and depth were well designed. Our devices provided a single longitudinal mode with the maximum CW output power up to 48.8 mW/facet at 971.31 nm at 250 mA without facet coating, 3dB linewidth (39 dB). Optical bistable characteristic was observed with a threshold current difference. Experimentally, devices with different cavity lengths were contrasted on power-current and spectrum characteristics. Due to easy fabrication technique and stable performance, it provides a method of fabricating practical gain-coupled distributed feedback lasers for commercial applications.

Mitigation of inbreeding while preserving genetic gain in genomic breeding programs for outbred plants.

Science.gov (United States)

Lin, Zibei; Shi, Fan; Hayes, Ben J; Daetwyler, Hans D

2017-05-01

Heuristic genomic inbreeding controls reduce inbreeding in genomic breeding schemes without reducing genetic gain. Genomic selection is increasingly being implemented in plant breeding programs to accelerate genetic gain of economically important traits. However, it may cause significant loss of genetic diversity when compared with traditional schemes using phenotypic selection. We propose heuristic strategies to control the rate of inbreeding in outbred plants, which can be categorised into three types: controls during mate allocation, during selection, and simultaneous selection and mate allocation. The proposed mate allocation measure GminF allocates two or more parents for mating in mating groups that minimise coancestry using a genomic relationship matrix. Two types of relationship-adjusted genomic breeding values for parent selection candidates ([Formula: see text]) and potential offspring ([Formula: see text]) are devised to control inbreeding during selection and even enabling simultaneous selection and mate allocation. These strategies were tested in a case study using a simulated perennial ryegrass breeding scheme. As compared to the genomic selection scheme without controls, all proposed strategies could significantly decrease inbreeding while achieving comparable genetic gain. In particular, the scenario using [Formula: see text] in simultaneous selection and mate allocation reduced inbreeding to one-third of the original genomic selection scheme. The proposed strategies are readily applicable in any outbred plant breeding program.

Factors Related to Weight Gain/Loss among Emerging Adults with Obesity.

Science.gov (United States)

Johnson, Ping H; Annesi, James J

2018-05-01

We examined the reasons for weight gain and barriers to weight loss among emerging adults with obesity. Eighty-one female undergraduate students with obesity completed 4-open ended questions in 2015-2016. Qualitative responses were analyzed using NVivo 11 Pro software. Most participants experienced weight gain prior to attending college. The most commonly reported reasons for weight gain include a lack of ability to control one's behaviors or overcome barriers (ie, poor eating habits, lack of physical activity, lack of time, easy access to food), emotional/mental health issues, physical health, and influence of significant others. Nearly half reported having a weight loss goal. Most reported having used one or more weight loss methods. Few reached short-term weight loss but quickly regained the lost weight. Major reported barriers reflect a lack of self-regulation skills, negative mood and stress, and lack of self-efficacy for healthy eating or physical activity. Results suggest that the perceived ability to control one's behaviors and overcome barriers, self-efficacy, and mood are important in weight-related behaviors, weight, and weight loss success among emerging adults, especially those enrolled in college.

Decentralized controller gain scheduling using PSO for power ...

African Journals Online (AJOL)

For this reason, in this study the P and I control parameters are tuned based on Particle Swarm Optimization (PSO) algorithm for a better Load-Frequency Control in a Two-Area Two-Unit Thermal Reheat Power System (TATURIPS) with step load perturbation. To exemplify the optimum parameter search PSO is used as it is ...

Weight gain following treatment of hyperthyroidism.

Science.gov (United States)

Dale, J; Daykin, J; Holder, R; Sheppard, M C; Franklyn, J A

2001-08-01

Patients frequently express concern that treating hyperthyroidism will lead to excessive weight gain. This study aimed to determine the extent of, and risk factors for, weight gain in an unselected group of hyperthyroid patients. We investigated 162 consecutive hyperthyroid patients followed for at least 6 months. Height, weight, clinical features, biochemistry and management were recorded at each clinic visit. Documented weight gain was 5.42 +/- 0.46 kg (mean +/- SE) and increase in BMI was 8.49 +/- 0.71%, over a mean 24.2 +/- 1.6 months. Pre-existing obesity, Graves' disease causing hyperthyroidism, weight loss before presentation and length of follow-up each independently predicted weight gain. Patients treated with thionamides or radioiodine gained a similar amount of weight (thionamides, n = 87, 5.16 +/- 0.63 kg vs. radioiodine, n = 62, 4.75 +/- 0.57 kg, P = 0.645), but patients who underwent thyroidectomy (n = 13) gained more weight (10.27 +/- 2.56 kg vs. others, P = 0.007). Development of hypothyroidism (even transiently) was associated with weight gain (never hypothyroid, n = 102, 4.57 +/- 0.52 kg, transiently hypothyroid, n = 29, 5.37 +/- 0.85 kg, on T4, n = 31, 8.06 +/- 1.42 kg, P = 0.014). This difference remained after correcting for length of follow-up. In the whole cohort, weight increased by 3.95 +/- 0.40 kg at 1 year (n = 144) to 9.91 +/- 1.62 kg after 4 years (n = 27) (P = 0.008), representing a mean weight gain of 3.66 +/- 0.44 kg/year. We have demonstrated marked weight gain after treatment of hyperthyroidism. Pre-existing obesity, a diagnosis of Graves' disease and prior weight loss independently predicted weight gain and weight continued to rise with time. Patients who became hypothyroid, despite T4 replacement, gained most weight.

Pulsed neutron logging system for inelastic scattering gamma rays with gain compensation

International Nuclear Information System (INIS)

Schultz, W.E.; Smith, H.D. Jr.

1976-01-01

An illustrative embodiment of the invention includes methods for linearizing the gain of borehole gamma ray energy measurement apparatus. A known energy peak (or peaks) which is prominent in the gamma ray energy spectra of borehole measurements is monitored and any drift in its apparent location in the energy spectrum is used to generate an error voltage. The error voltage is applied in an inverse feedback manner to control the gain of system amplifiers to cancel the drift

Target-matched insertion gain derived from three different hearing aid selection procedures.

Science.gov (United States)

Punch, J L; Shovels, A H; Dickinson, W W; Calder, J H; Snead, C

1995-11-01

Three hearing aid selection procedures were compared to determine if any one was superior in producing prescribed real-ear insertion gain. For each of three subject groups, 12 in-the-ear style hearing aids with Class D circuitry and similar dispenser controls were ordered from one of three manufacturers. Subject groups were classified based on the type of information included on the hearing aid order form: (1) the subject's audiogram, (2) a three-part matrix specifying the desired maximum output, full-on gain, and frequency response slope of the hearing aid, or (3) the desired 2-cc coupler full-in grain of the hearing aid, based on real-ear coupler difference (RECD) measurements. Following electroacoustic adjustments aimed at approximating a commonly used target insertion gain formula, results revealed no significant differences among any of the three selection procedures with respect to obtaining acceptable insertion gain values.

Money matters. Financial world looks at oil companies with Argus eyes

International Nuclear Information System (INIS)

Van Gool, M.

2008-01-01

The financial markets foresee high risks in the energy sector for the big, private oil companies such as ExxonMobil, Shell and BP. It appears that these companies are undervalued, In contrast, financial backers are justifiably positive about companies providing services to the oil sector, such as Schlumberger and Halliburton, and 'utilities', such as Eon and EDF, which still have considerable room for growth, The relatively high valuation of state-controlled oil and gas companies such as Gazprom is somewhat more speculative

[原著］Effect of Meal-Timing on Body Weight Gain in Young Women

OpenAIRE

Wang, Ming-Fu; Huang, Sheng-Chi; Chung, Hei-Mei; Lo, Shuen-Fang; Haeno, Fumiyo; Nomura, Satomi; Ikemiyasiro, Midori; Shinjo, Sumie; Asato, Liu; Yamamoto, Shigeru; Department of Food and Nutrition, Providence University, Taichung, Taiwan; Research Center of Comprehensive Medicine. Faculty of Medicine, University of the Ryukyus, Okinawa, Japan

1993-01-01

This study was designed to find when to eat for better weight control. Five experiments of 10 days duration were done with 7 young women volunteers. The daily energy intake was 33 kcal/kg in all the experiments but the time or size of meals was different in each experiment. We observed that the later the time of dinner, the more the weight gain; breakfast did not have any effect on the weight gain and an evening snack before dinner prevented weight gain due to a late dinner. These results sug...

Effect of Experimental Coccidiosis Infections on Body Weight Gain ...

African Journals Online (AJOL)

Infections with E. tenella in broiler breeder males showed that body weight gains of the uninfected males were significantly greater (p< 0.05) at 5, 7 and 14 days post inoculation (dpi) than those of the infected groups. Sperm productions at 0, 5 and 7 dpi (0=day of inoculation with infected oocysts) for the uninfected controls ...

Receiver Gain Modulation Circuit

Science.gov (United States)

Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

2011-01-01

A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

A high gain modified SEPIC DC-to-DC boost converter for renewable energy application

DEFF Research Database (Denmark)

Maroti, Pandav Kiran; Padmanaban, Sanjeevikumar; Bhaskar, Mahajan Sagar

2017-01-01

The proposed work present the modified high gain Single Ended Primary Inductance Converter (SEPIC) for renewable energy applications. The voltage gain of proposed converter is very highly related to conventional dc-to-dc converter and recently projected converter based on conventional converter....... The key feature of projected converter is only one controlled device and voltage gain is increased without using a transformer and coupled inductor structure. The voltage gain of projected converter is increased by 10 times compared to the SEPIC converter by adding one extra inductor and capacitor...... in SEPIC converter for a duty ratio of 90%. The detailed analysis of the voltage gain with the voltage drop across passive device and working of projected converter is deliberated in details in the paper. The projected converter is simulated in Matrix Laboratory software (2014). The simulation results...

Associated petroleum gas in Russia: reasons for non-utilization

Energy Technology Data Exchange (ETDEWEB)

Roeland, Tonje Hulbak

2010-10-22

This report studies the factors hindering increased utilization of associated petroleum gas (APG) in Russia. The issue of flaring versus utilization is studied from a Technology Innovation System (TIS) perspective, seeing the non-utilization issue as a problem of technology diffusion. There are many technological options available for APG utilization, but a main blocking mechanism in the Russian case is the Gazprom monopoly on gas transportation via their pipelines. A commonly discussed solution is policy to ensure third party access, but this study finds that this solution holds little potential, as its ramifications are too extensive and unacceptable to the key actor Gazprom. More promising solutions may be found in small, emerging engineering companies. (Author)

Energy Gaining Windows for Residental Buildings

DEFF Research Database (Denmark)

Kragh, Jesper; Laustsen, Jacob Birck; Svendsen, Svend

2008-01-01

This paper presents some of the research done during the last 8 years at the Technical University of Denmark developing improved low-energy window solutions. The focus has been on maximizing the net energy gain of windows for residential buildings. The net energy gain of windows is the solar gain...... minus the heat loss integrated over the heating season. It is assumed that in northern cold climates all of the solar gain during the heating season can be utilized for space heating. Problems with overheating in the summer period must be solved with overhang or moveable solar shading devices. Two...... and longer durability of the window. The glazing in these fiber reinforced polyester windows is both unsealed and sealed triple glazing units. To increase the net energy gain slim frame profiles have been developed to increase the glazing area and thereby the solar gain. The challenge when developing slim...

Small-signal gain spectrum of an 1800-torr CO2 amplifier

International Nuclear Information System (INIS)

Goldstein, J.C.; Haglund, R.F. Jr.; Comly, J.

1981-01-01

Prominent hot band effects have been observed in the 9.4 and 10.6 μm gain spectrum of an 1800 torr electron-beam-controlled-discharge CO 2 laser amplifier. Theoretical calculations agree well with data at 53 wavelengths

ℋ∞ constant gain state feedback stabilization of stochastic hybrid systems with Wiener process

Directory of Open Access Journals (Sweden)

E. K. Boukas

2004-01-01

Full Text Available This paper considers the stabilization problem of the class of continuous-time linear stochastic hybrid systems with Wiener process. The ℋ∞ state feedback stabilization problem is treated. A state feedback controller with constant gain that does not require access to the system mode is designed. LMI-based conditions are developed to design the state feedback controller with constant gain that stochastically stabilizes the studied class of systems and, at the same time, achieve the disturbance rejection of a desired level. The minimum disturbance rejection is also determined. Numerical examples are given to show the usefulness of the proposed results.

Gain-assisted superluminal propagation and rotary drag of photon and surface plasmon polaritons

Science.gov (United States)

Khan, Naveed; Amin Bacha, Bakht; Iqbal, Azmat; Ur Rahman, Amin; Afaq, A.

2017-07-01

Superluminal propagation of light is a well-established phenomenon and has motivated immense research interest that has led to state-of-the-art knowledge and potential applications in the emerging technology of quantum optics and photonics. This study presents a theoretical analysis of the gain-assisted superluminal light propagation in a four-level N -type atomic system by exploiting the scheme of electromagnetically induced gain and superluminal propagation of surface plasmon polaritons (SPPs) along the gain-assisted atomic-metal interface simultaneously. In addition, a theoretical demonstration is presented on the comparison between Fresnel's rotary photon drag and SPP drag in view of light polarization state rotation by rotating the coherent atomic medium and the atomic-metal interface, respectively. Analogous to photon drag in the superluminal anomalous dispersion region where light polarization rotation occurs opposite the rotation of the gain-assisted atomic medium, the rotation of the atomic-metal interface also rotates the polarization state of SPPs opposite the rotation of the interface. This further confirms the superluminal nature of SPPs propagating along the interface with negative group velocity. Rabi frequencies of the control and pump fields considerably modify both photon and SPP drag coefficients. Metal conductivity also controls SPP propagation.

Brüssel lasi Eesti Gaasi hoone läbi otsida / Gert D. Hankewitz

Index Scriptorium Estoniae

Hankewitz, Gert D.

2011-01-01

Euroopa Liidu konkurentsiametnikud korraldasid läbiotsimise Vene energiaettevõttes Gazprom ja selle klientide kontorites, kahtlustades turu kuritarvitamist, läbiotsitud firmade seas on ka Eesti Gaas

The natural gas industry in Russia: reforms in debate

International Nuclear Information System (INIS)

Locatelli, Catherine

2014-07-01

Due to the emergence of shale gas in the USA, Russia has become the second world producer of natural gas but this industry remains one of the most important sectors of the Russian economy as natural gas exports are an essential component or the Russian economic policy. Addressing this industry, the author first comments the evolutions of gas production since 1960 and its perspectives by 2020 and 2030. He also outlines the importance of the cost issue associated with the choice between mega projects and smaller ones. In a second part, the author comments and discusses the evolutions of gas exports towards Europe and of the export strategy. He evokes the possibility of arbitration between price and quantity in Gazprom's strategy, the possibility of a strategy of downstream integration on European gas markets, the possibility of a diversification of export markets (notably LNG markets as several LNG projects are planned). In the third part, the author describes the Gazprom model, comments the recurring debate on a reform of this holding, and discusses its quantity-based management and the issue of Gazprom's efficiency. He briefly evokes the issue of reform of the Russian gas industry, the progressive emergence of new actors

Optimal weight gain in triplet pregnancies.

Science.gov (United States)

Johnston, Robert C; Erfani, Hadi; Shamshirsaz, Amir A; Spiel, Melissa; Ravangard, Sam F; Shaman, Majid; Allaf, M Baraa; Shamshirsaz, Alireza A; Haeri, Sina

2017-08-01

To identify appropriate weight gain in triplet gestations, which may aid in reducing the risk of perinatal morbidity within this high-risk cohort. This retrospective cohort study evaluated all non-anomalous triplet pregnancies between 23 and 40 weeks' gestation resulting in live births at five tertiary-care medical centers between 1991 and 2011. Subjects were divided by pre-pregnancy BMI into underweight, normal-weight, overweight, and obese groups, and then stratified by low (gain (≥1.5 lbs/week). Primary outcomes included spontaneous preterm birth and preeclampsia. We included 116 mothers and 348 corresponding neonates for final analysis. The incidence of preeclampsia and preterm delivery less than 32 weeks' gestation was 37% and 41%, respectively. The incidence of preeclampsia increased with weight gain per week, but was not statistically different from subjects who gained less weight. We found no statistical correlation between weight gain per week and preterm delivery. We found no association between preeclampsia or preterm delivery and increasing weight gain in triplet pregnancies. The association with increased risk for preeclampsia was predominantly due to BMI effect. Based on the current study, recommendations for optimal weight gain in mothers with triplet gestations could not be defined.

Utility of barium studies for patients with recurrent weight gain after Roux-en-Y gastric bypass

International Nuclear Information System (INIS)

Wang, B.; Levine, M.S.; Rubesin, S.E.; Williams, N.N.; Dumon, K.; Raper, S.

2015-01-01

Aim: To determine the utility of barium studies for detecting abnormalities responsible for recurrent weight gain after gastric bypass surgery. Methods: A computerized search identified 42 patients who had undergone barium studies for recurrent weight gain after gastric bypass and 42 controls. The images were reviewed to determine the frequency of staple-line breakdown and measure the length/width of the pouch and gastrojejunal anastomosis. A large pouch exceeded 6 cm in length or 5 cm in width and a wide anastomosis exceeded 2 cm. Records were reviewed for the amount of recurrent weight gain and subsequent weight loss after additional treatment. Results: Staple-line breakdown was present in 6/42 patients (14%) with recurrent weight gain. When measurements were obtained, 13/35 patients (37%) with recurrent weight gain had a large pouch, three (9%) had a wide anastomosis, and four (11%) had both, whereas 22/42 controls (52%) had a large pouch, one (2%) had a wide anastomosis, and two (5%) had both. Ten patients (24%) with recurrent weight gain underwent staple-line repair (n = 3) or pouch/anastomosis revision (n = 7). These 10 patients had a mean weight loss of 38.1 lbs versus a mean loss of 8.6 lbs in 19 patients managed medically. Conclusion: Only 14% of patients with recurrent weight gain after gastric bypass had staple-line breakdown, whereas 57% had a large pouch, wide anastomosis, or both. Not all patients with abnormal anatomy had recurrent weight gain, but those who did were more likely to benefit from surgical intervention than from medical management. - Highlights: • Only 14% of patients with recurrent weight gain after gastric bypass had GGFs. • The majority of patients with recurrent weight gain had a large pouch/wide GJA. • Many patients without recurrent weight gain also had a large pouch/wide GJA. • Those with weight gain and a large pouch/wide GJA are likely to benefit from surgery

Improved synthetic-heterodyne Michelson interferometer vibrometer using phase and gain control feedback.

Science.gov (United States)

Galeti, José Henrique; Kitano, Cláudio; Connelly, Michael J

2015-12-10

Synthetic-heterodyne demodulation is a useful technique for dynamic displacement and velocity measurement using interferometric sensors as it can provide an output signal which is immune to interferometric drift. With the advent of cost effective, high-speed real-time signal processing systems and software, processing of the complex signals encountered in interferometry has become more feasible. In conventional synthetic-heterodyne demodulation schemes, to obtain the dynamic displacement or vibration of the object under test requires knowledge of the interferometer visibility and also the argument of two Bessel functions. In this paper, a new synthetic-heterodyne demodulation method is described leading to an expression for the dynamic displacement and velocity of the object under test that is significantly less sensitive to the received optical power. In addition, the application of two independent phase and gain feedback loops is used to compensate for the nonideal gain and phase response of the anti-aliasing filter required for the signal acquisition of the received wideband interferometer signal. The efficacy of the improved system is demonstrated by measuring the displacement sensitivity frequency response and linearity of a Piezoelectric Mirror-Shifter (PMS) over a range of 200 Hz-9 kHz. In addition, the system is used to measure the response of the PMS to triangular and impulse type stimuli. The experimental results show excellent agreement with measurements taken using two independent industry standard calibration methods.

Gain Enhancement of Low-Profile, Electrically Small Capacitive Feed Antennas Using Stacked Meander Lines

Directory of Open Access Journals (Sweden)

Kazuki Ide

2010-01-01

Full Text Available The present paper describes the gain enhancement of a small and low-profile linear antenna with capacitive feed (C-feed using three metallic layers. The antenna has very small leakage current on the outer conductor of the coaxial cable and can easily control the imaginary part of the input impedance. The gain of the stacked three-layer meander line antenna, with the meander line in the middle layer being opposite to that of the other two layers, has increased by around 7 dB compared to the single layered C-feed antenna. The antenna gain is discussed based on simulated and measured results, which demonstrates that the antenna has successfully achieved the acceptable impedance and sufficient gain for mobile terminals and RFID tags.

Weight Gain following Pallidal Deep Brain Stimulation: A PET Study.

Directory of Open Access Journals (Sweden)

Paul Sauleau

Full Text Available The mechanisms behind weight gain following deep brain stimulation (DBS surgery seem to be multifactorial and suspected depending on the target, either the subthalamic nucleus (STN or the globus pallidus internus (GPi. Decreased energy expenditure following motor improvement and behavioral and/or metabolic changes are possible explanations. Focusing on GPi target, our objective was to analyze correlations between changes in brain metabolism (measured with PET and weight gain following GPi-DBS in patients with Parkinson's disease (PD. Body mass index was calculated and brain activity prospectively measured using 2-deoxy-2[18F]fluoro-D-glucose PET four months before and four months after the start of GPi-DBS in 19 PD patients. Dopaminergic medication was included in the analysis to control for its possible influence on brain metabolism. Body mass index increased significantly by 0.66 ± 1.3 kg/m2 (p = 0.040. There were correlations between weight gain and changes in brain metabolism in premotor areas, including the left and right superior gyri (Brodmann area, BA 6, left superior gyrus (BA 8, the dorsolateral prefrontal cortex (right middle gyrus, BAs 9 and 46, and the left and right somatosensory association cortices (BA 7. However, we found no correlation between weight gain and metabolic changes in limbic and associative areas. Additionally, there was a trend toward a correlation between reduced dyskinesia and weight gain (r = 0.428, p = 0.067. These findings suggest that, unlike STN-DBS, motor improvement is the major contributing factor for weight gain following GPi-DBS PD, confirming the motor selectivity of this target.

Unequal Gain of Equal Resources across Racial Groups

Directory of Open Access Journals (Sweden)

Shervin Assari

2018-01-01

Full Text Available The health effects of economic resources (eg, education, employment, and living place and psychological assets (eg, self-efficacy, perceived control over life, anger control, and emotions are well-known. This article summarizes the results of a growing body of evidence documenting Blacks’ diminished return, defined as a systematically smaller health gain from economic resources and psychological assets for Blacks in comparison to Whites. Due to structural barriers that Blacks face in their daily lives, the very same resources and assets generate smaller health gain for Blacks compared to Whites. Even in the presence of equal access to resources and assets, such unequal health gain constantly generates a racial health gap between Blacks and Whites in the United States. In this paper, a number of public policies are recommended based on these findings. First and foremost, public policies should not merely focus on equalizing access to resources and assets, but also reduce the societal and structural barriers that hinder Blacks. Policy solutions should aim to reduce various manifestations of structural racism including but not limited to differential pay, residential segregation, lower quality of education, and crime in Black and urban communities. As income was not found to follow the same pattern demonstrated for other resources and assets (ie, income generated similar decline in risk of mortality for Whites and Blacks, policies that enforce equal income and increase minimum wage for marginalized populations are essential. Improving quality of education of youth and employability of young adults will enable Blacks to compete for high paying jobs. Policies that reduce racism and discrimination in the labor market are also needed. Without such policies, it will be very difficult, if not impossible, to eliminate the sustained racial health gap in the United States.

An Optimal Control Modification to Model-Reference Adaptive Control for Fast Adaptation

Science.gov (United States)

Nguyen, Nhan T.; Krishnakumar, Kalmanje; Boskovic, Jovan

2008-01-01

This paper presents a method that can achieve fast adaptation for a class of model-reference adaptive control. It is well-known that standard model-reference adaptive control exhibits high-gain control behaviors when a large adaptive gain is used to achieve fast adaptation in order to reduce tracking error rapidly. High gain control creates high-frequency oscillations that can excite unmodeled dynamics and can lead to instability. The fast adaptation approach is based on the minimization of the squares of the tracking error, which is formulated as an optimal control problem. The necessary condition of optimality is used to derive an adaptive law using the gradient method. This adaptive law is shown to result in uniform boundedness of the tracking error by means of the Lyapunov s direct method. Furthermore, this adaptive law allows a large adaptive gain to be used without causing undesired high-gain control effects. The method is shown to be more robust than standard model-reference adaptive control. Simulations demonstrate the effectiveness of the proposed method.

Pengaturan Kecepatan Motor Spindle pada Retrofit Mesin Bubut CNC Menggunakan Kontroler PID Gain Scheduling

Directory of Open Access Journals (Sweden)

Fikri Yoga Permana

2013-03-01

Full Text Available Pada mesin bubut Computerized Numerical Control (CNC, proses pemahatan benda kerja memerlukan kecepatan potong yang tetap agar hasil kerja memiliki tingkat presisi tinggi. Dalam prakteknya, ketika terjadi pemotongan, diameter benda kerja akan selalu berkurang dan tingkat kedalaman pahat berubah-ubah sesuai dengan proses yang dilakukan sehingga mempengaruhi kecepatan putar motor spindle sehingga mengakibatkan tingkat presisi hasil kerja menjadi berkurang. Pada penelitian ini, digunakan kontroler PI Gain Scheduling untuk mengatur kecapatan motor spindle. Hasil yang didapatkan berupa simulasi kontroler PI Gain Scheduling. Dari hasil simulasi didapatkan kontroler PI Gain Scheduling mampu membuat respon sistem sesuai dengan yang diinginkan.

A randomized controlled trial to prevent excessive gestational weight gain and promote postpartum weight loss in overweight and obese women: Health In Pregnancy and Postpartum (HIPP).

Science.gov (United States)

Wilcox, Sara; Liu, Jihong; Addy, Cheryl L; Turner-McGrievy, Gabrielle; Burgis, Judith T; Wingard, Ellen; Dahl, Alicia A; Whitaker, Kara M; Schneider, Lara; Boutté, Alycia K

2018-03-01

Interventions to prevent excessive gestational weight gain and promote postpartum weight loss have yielded modest results, particularly in overweight and obese women. To examine the impact of a theory-based lifestyle intervention on gestational weight gain, postpartum weight loss, and related maternal and child outcomes and to examine race differences in these outcomes. A randomized controlled trial (target N=400; 200 intervention, 200 standard care; 200 African American, 200 white). Overweight and obese African American and white women ≤16weeks gestation are recruited from obstetrics and gynecology clinics in South Carolina. Intervention participants receive two in-depth counseling sessions (early pregnancy and postpartum), telephone counseling, behavioral podcasts, and social media support that target weight self-monitoring and increasing physical activity and healthy dietary behavior practices, guided by Social Cognitive Theory. Standard care participants receive monthly mailings and a matched number of podcasts on non-weight related topics. All intervention activities last from ≤18weeks gestation to 6months after delivery. Gestational weight gain is the primary outcome. Secondary outcomes are meeting gestational weight gain guidelines (inadequate, adequate, excessive), weekly rate of gestational weight gain, postpartum weight retention, physical activity and dietary behaviors, health-related quality of life, and offspring adiposity. Participants are assessed at baseline (≤16weeks gestation), 32weeks gestation, and 6 and 12months postpartum, and offspring are assessed at 6 and 12months. HIPP is an innovative study that addresses significant gaps in the literature. Primary outcome results are expected in 2019. Copyright © 2018 Elsevier Inc. All rights reserved.

Temporal dynamics of contrast gain in single cells of the cat striate cortex.

Science.gov (United States)

Bonds, A B

1991-03-01

The response amplitude of cat striate cortical cells is usually reduced after exposure to high-contrast stimuli. The temporal characteristics and contrast sensitivity of this phenomenon were explored by stimulating cortical cells with drifting gratings in which contrast sequentially incremented and decremented in stepwise fashion over time. All responses showed a clear hysteresis, in which contrast gain dropped on average 0.36 log unit and then returned to baseline values within 60 s. Noticeable gain adjustments were seen in as little as 3 s and with peak contrasts as low as 3%. Contrast adaptation was absent in responses from LGN cells. Adaptation was found to depend on temporal frequency of stimulation, with greater and more rapid adaptation at higher temporal frequencies. Two different tests showed that the mechanism controlling response reduction was influenced primarily by stimulus contrast rather than response amplitude. These results support the existence of a rapid and sensitive cortically based system that normalizes the output of cortical cells as a function of local mean contrast. Control of the adaptation appears to arise at least in part across a population of cells, which is consistent with the idea that the gain control serves to limit the information converging from many cells onto subsequent processing areas.

Measurement of Antenna Bore-Sight Gain

Science.gov (United States)

Fortinberry, Jarrod; Shumpert, Thomas H.

2016-01-01

The absolute or free-field gain of a simple antenna can be approximated using standard antenna theory formulae or for a more accurate prediction, numerical methods may be employed to solve for antenna parameters including gain. Both of these methods will result in relatively reasonable estimates but in practice antenna gain is usually verified and documented via measurements and calibration. In this paper, a relatively simple and low-cost, yet effective means of determining the bore-sight free-field gain of a VHF/UHF antenna is proposed by using the Brewster angle relationship.

High Gain Advanced GPS Receiver

National Research Council Canada - National Science Library

Brown, Alison; Zhang, Gengsheng

2006-01-01

NAVSYS High Gain Advanced GPS Receiver (HAGR) uses a digital beam-steering antenna array to enable up to eight GPS satellites to be tracked, each with up to 10 dBi of additional antenna gain over a conventional receiver solution...

Determination of the STIS CCD Gain

Science.gov (United States)

Riley, Allyssa; Monroe, TalaWanda; Lockwood, Sean

2016-09-01

This report summarizes the analysis and absolute gain results of the STIS Cycle 23 special calibration program 14424 that was designed to measure the gain of amplifiers A, C and D at nominal gain settings of 1 and 4 e-/DN. We used the mean-variance technique and the results indicate a mean-variance technique.

Comparison of dual-time-constant and fast-acting automatic gain control (AGC) systems in cochlear implants.

Science.gov (United States)

Boyle, Patrick J; Büchner, Andreas; Stone, Michael A; Lenarz, Thomas; Moore, Brian C J

2009-04-01

Cochlear implants usually employ an automatic gain control (AGC) system as a first stage of processing. AGC1 was a fast-acting (syllabic) compressor. AGC2 was a dual-time-constant system; it usually performed as a slow-acting compressor, but incorporated an additional fast-acting system to provide protection from sudden increases in sound level. Six experienced cochlear-implant users were tested in a counterbalanced order, receiving one-month of experience with a given AGC type before switching to the other type. Performance was evaluated shortly after provision of a given AGC type and after one-month of experience with that AGC type. Questionnaires, mainly relating to listening in quiet situations, did not reveal significant differences between the two AGC types. However, fixed-level and roving-level tests of sentence identification in noise both revealed significantly better performance for AGC2. It is suggested that the poorer performance for AGC1 occurred because AGC1 introduced cross-modulation between the target speech and background noise, which made perceptual separation of the target and background more difficult.

PI fussy multimodal controller of programmed gains for the operation in the wide range of a turbo gas unit; Controlador PI difuso multimodo de ganancias programadas para la operacion en rango amplio de una unidad turbogas

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Martinez, Arnulfo A.

2004-11-15

In this thesis work it was developed a new control algorithm which merges the characteristics of multimode control, gain scheduling control and fuzzy logic techniques, in order to obtain a control system which gives a better gas turbine speed and load control performance, as compared to the current control systems, which are based on conventional PI control algorithms. This new algorithm is intended to provide a better quality control system, which provides both better disturbance rejection response, as well as better reference tracking response. Switching logic (multimode control) and interpolation strategy (gain scheduling) implementation problems are solved applying fuzzy controllers, which retain the advantages of both strategies for non lineal processes in wide operation regions. Since the controllers implemented by the fuzzy system rules are of the same type (PI, Proportional Integral), the multimode gain scheduling fuzzy controller design was reduced to the design of a gain scheduling fuzzy PI controller (PI-GSF). In order to define the gain scheduling scheme, three well-known gain scheduling fuzzy controller design approaches were analyzed and the interpolation mechanism of each of them were compared. The incorporation of a generalized PI controller structure in the local controllers that conform the PI-GSF (see chapter 4), allowed to generate a better control action for both disturbance rejection and reference tracking. As a final product a PI-GSF controller was obtained, which constitutes a more effective control strategy and showed to be a viable solution to the outlined technological problem. With the PI-GSF controller the speed control performance of the generating unit during startup stage, as well as the load control during the generation stage were considerably improved, as compared to the performance obtained with the conventional PI. [Spanish] En este trabajo de tesis se desarrollo un nuevo algoritmo de control que conjunta las caracteristicas de

Novel LY Converter Topologies for High Gain Transfer Ratio - A New Breed of XY Family

DEFF Research Database (Denmark)

Bhaskar, M.S.; Padmanaban, S.; Kulkarni, R.

2016-01-01

gain and minimum internal resistance; such as a photovoltaic MLI system, high voltage applications and electrical drives. The conspicuous features of proposed LY converter topologies are i) Single power control switch ii) Single Input source iii) Inverting output voltage iv) Transformer-less converter...... topologies v) High inverting voltage gain with moderate duty ratio vi) Less number of power devices and components. The proposed topologies have minimum internal resistance and its effect on voltage gain of LY converter is also discussed in detail. The simulation results are presented and the result...

Nonunity gain minimal-disturbance measurement

DEFF Research Database (Denmark)

Sabuncu, Metin; Mišta, L.; Fiurášek, J.

2007-01-01

We propose and experimentally demonstrate an optimal nonunity gain Gaussian scheme for partial measurement of an unknown coherent state that causes minimal disturbance of the state. The information gain and the state disturbance are quantified by the noise added to the measurement outcomes...

Acting to gain information

Science.gov (United States)

Rosenchein, Stanley J.; Burns, J. Brian; Chapman, David; Kaelbling, Leslie P.; Kahn, Philip; Nishihara, H. Keith; Turk, Matthew

1993-01-01

This report is concerned with agents that act to gain information. In previous work, we developed agent models combining qualitative modeling with real-time control. That work, however, focused primarily on actions that affect physical states of the environment. The current study extends that work by explicitly considering problems of active information-gathering and by exploring specialized aspects of information-gathering in computational perception, learning, and language. In our theoretical investigations, we analyzed agents into their perceptual and action components and identified these with elements of a state-machine model of control. The mathematical properties of each was developed in isolation and interactions were then studied. We considered the complexity dimension and the uncertainty dimension and related these to intelligent-agent design issues. We also explored active information gathering in visual processing. Working within the active vision paradigm, we developed a concept of 'minimal meaningful measurements' suitable for demand-driven vision. We then developed and tested an architecture for ongoing recognition and interpretation of visual information. In the area of information gathering through learning, we explored techniques for coping with combinatorial complexity. We also explored information gathering through explicit linguistic action by considering the nature of conversational rules, coordination, and situated communication behavior.

Energy gains from lattice-enabled nuclear reactions

International Nuclear Information System (INIS)

Nagel, David J.

2015-01-01

The energy gain of a system is defined as the ratio of its output energy divided by the energy provided to operate the system. Most familiar systems have energy gains less than one due to various inefficiencies. By contrast, lattice-enabled nuclear reactions (LENR) offer high energy gains. Theoretical values in excess of 1000 are possible. Energy gains over 100 have already been reported. But, they have not yet been sustained for commercially significant durations. This article summarizes the current status of LENR energy gains. (author)

Control of the inversionless gain and refractive index in a V-type atom via squeezed vacuum and quantum interference

International Nuclear Information System (INIS)

Anton, M.A.; Calderon, Oscar G.; Carreno, F.

2004-01-01

In this paper we analyze the steady-state populations and gain lineshape of a V-type three-level atom with a closely spaced excited doublet. The atom is driven by a strong coherent field, a weak probe, and a single broadband squeezed vacuum. We focus our attention in the interplay between the quantum interference and the squeezed field on the probe gain. It is shown that the relative phases between the two coherent fields and the squeezed field play an important role in the optical properties of the atom. Specifically, we find that the probe can experience gain without population inversion for proper values of the parameters characterizing the squeezed field and in the absence of incoherent pumping. The system can be tailored to exhibit multiple dispersion regimes accompanied by negligible gain or absorption over a large bandwidth, a desirable feature for obtaining propagation of pulses with negligible distortion

Charge Gain, Voltage Gain, and Node Capacitance of the SAPHIRA Detector Pixel by Pixel

Science.gov (United States)

Pastrana, Izabella M.; Hall, Donald N. B.; Baker, Ian M.; Jacobson, Shane M.; Goebel, Sean B.

2018-01-01

The University of Hawai`i Institute for Astronomy has partnered with Leonardo (formerly Selex) in the development of HgCdTe linear mode avalanche photodiode (L-APD) SAPHIRA detectors. The SAPHIRA (Selex Avalanche Photodiode High-speed Infra-Red Array) is ideally suited for photon-starved astronomical observations, particularly near infrared (NIR) adaptive optics (AO) wave-front sensing. I have measured the stability, and linearity with current, of a 1.7-um (10% spectral bandpass) infrared light emitting diode (IR LED) used to illuminate the SAPHIRA and have then utilized this source to determine the charge gain (in e-/ADU), voltage gain (in uV/ADU), and node capacitance (in fF) for each pixel of the 320x256@24um SAPHIRA. These have previously only been averages over some sub-array. Determined from the ratio of the temporal averaged signal level to variance under constant 1.7-um LED illumination, I present the charge gain pixel-by-pixel in a 64x64 sub-array at the center of the active area of the SAPHIRA (analyzed separately as four 32x32 sub-arrays) to be about 1.6 e-/ADU (σ=0.5 e-/ADU). Additionally, the standard technique of varying the pixel reset voltage (PRV) in 10 mV increments and recording output frames for the same 64x64 subarray found the voltage gain per pixel to be about 11.7 uV/ADU (σ=0.2 uV/ADU). Finally, node capacitance was found to be approximately 23 fF (σ=6 fF) utilizing the aforementioned charge and voltage gain measurements. I further discuss the linearity measurements of the 1.7-um LED used in the charge gain characterization procedure.

Can weight gain be prevented in women receiving treatment for breast cancer? A systematic review of intervention studies.

Science.gov (United States)

Thomson, Z O; Reeves, M M

2017-11-01

Obesity and weight gain have been associated with poor disease-specific and health-related outcomes in women with breast cancer. This review aimed to evaluate the effectiveness of weight gain prevention interventions among women with breast cancer. Completed and ongoing trials evaluating a behaviourally based dietary intervention with or without physical activity and with a focus on weight gain prevention during treatment for breast cancer were reviewed. Weight change and body composition data were extracted. Within-group weight change of ±1 kg and between-group (intervention versus control) weight difference of ≥2 kg were defined as successful weight gain prevention. Five completed trials (seven intervention arms) and five ongoing trials were identified. Completed trials exclusively recruited premenopausal or premenopausal and postmenopausal women. Within-group weight gain was prevented in two intervention arms, two arms achieved weight loss and three arms reported weight gain. Of the five comparisons with control groups, two reported significant differences in weight change between groups. Ongoing trials will provide further evidence on longer-term outcomes, cost-effectiveness and blood markers. This small but growing number of studies provides preliminary and promising evidence that weight gain can be prevented in women with breast cancer undergoing chemotherapy. © 2017 World Obesity Federation.

The impact of a Classroom Performance System on learning gains in a biology course for science majors

Science.gov (United States)

Marin, Nilo Eric

This study was conducted to determine if the use of the technology known as Classroom Performance System (CPS), specifically referred to as "Clickers", improves the learning gains of students enrolled in a biology course for science majors. CPS is one of a group of developing technologies adapted for providing feedback in the classroom using a learner-centered approach. It supports and facilitates discussion among students and between them and teachers, and provides for participation by passive students. Advocates, influenced by constructivist theories, claim increased academic achievement. In science teaching, the results have been mixed, but there is some evidence of improvements in conceptual understanding. The study employed a pretest-posttest, non-equivalent groups experimental design. The sample consisted of 226 participants in six sections of a college biology course at a large community college in South Florida with two instructors trained in the use of clickers. Each instructor randomly selected their sections into CPS (treatment) and non-CPS (control) groups. All participants filled out a survey that included demographic data at the beginning of the semester. The treatment group used clicker questions throughout, with discussions as necessary, whereas the control groups answered the same questions as quizzes, similarly engaging in discussion where necessary. The learning gains were assessed on a pre/post-test basis. The average learning gains, defined as the actual gain divided by the possible gain, were slightly better in the treatment group than in the control group, but the difference was statistically non-significant. An Analysis of Covariance (ANCOVA) statistic with pretest scores as the covariate was conducted to test for significant differences between the treatment and control groups on the posttest. A second ANCOVA was used to determine the significance of differences between the treatment and control groups on the posttest scores, after

Comparison of Video Head Impulse Test (vHIT) Gains Between Two Commercially Available Devices and by Different Gain Analytical Methods.

Science.gov (United States)

Lee, Sang Hun; Yoo, Myung Hoon; Park, Jun Woo; Kang, Byung Chul; Yang, Chan Joo; Kang, Woo Suk; Ahn, Joong Ho; Chung, Jong Woo; Park, Hong Ju

2018-06-01

To evaluate whether video head impulse test (vHIT) gains are dependent on the measuring device and method of analysis. Prospective study. vHIT was performed in 25 healthy subjects using two devices simultaneously. vHIT gains were compared between these instruments and using five different methods of comparing position and velocity gains during head movement intervals. The two devices produced different vHIT gain results with the same method of analysis. There were also significant differences in the vHIT gains measured using different analytical methods. The gain analytic method that compares the areas under the velocity curve (AUC) of the head and eye movements during head movements showed lower vHIT gains than a method that compared the peak velocities of the head and eye movements. The former method produced the vHIT gain with the smallest standard deviation among the five procedures tested in this study. vHIT gains differ in normal subjects depending on the device and method of analysis used, suggesting that it is advisable for each device to have its own normal values. Gain calculations that compare the AUC of the head and eye movements during the head movements show the smallest variance.

Can LENR Energy Gains Exceed 1000?

Science.gov (United States)

Nagel, David J.

2011-03-01

Energy gain is defined as the energy realized from reactions divided by the energy required to produce those reactions. Low Energy Nuclear Reactions (LENR) have already been measured to significantly exceed the energy gain of 10 projected from ITER,possibly 15 years from now. Electrochemical experiments using the Pd-D system have shown energy gains exceeding 10. Gas phase experiments with the Ni-H system were reported to yield energy gains of over 100. Neither of these reports has been adequately verified or reproduced. However, the question in the title still deserves consideration. If, as thought by many, it is possible to trigger nuclear reactions that yield MeV energies with chemical energies of the order of eV, then the most optimistic expectation is that LENR gains could approach one million. Hence, the very tentative answer to the question above is yes. However, if LENR could be initiated with some energy cost, and then continue to ``burn,'' very high energy gains might be realized. Consider a match and a pile of dry logs. The phenomenon termed ``heat after death'' will be examined to see if it might be the initial evidence for nuclear ``burning.''

Characterization of transient gain x-ray lasers

International Nuclear Information System (INIS)

Dunn, J.; Osterheld, A.; Shlyaptsev, V.

1999-01-01

We have performed numerical simulations of the transient collisional excitation Ni-like Pd 4d → 4p J = 0 → 1 147 angstrom laser transition recently observed at Lawrence Livermore National Laboratory (LLNL). The high gain ∼35 cm results from the experiment are compared with detailed modeling simulations from the 1-D RADEX code in order to better understand the main physics issues affecting the measured gain and x-ray laser propagation along the plasma column. Simulations indicate that the transient gain lifetime associated with the short pulse pumping and refraction of the x-ray laser beam out of the gain region are the main detrimental effects. Gain lifetimes of ∼7 ps(1/e decay) are inferred from the smoothly changing gain experimental observations and are in good agreement with the simulations. Furthermore, the modeling results indicate the presence of a longer-lived but lower gain later in time associated with the transition from transient to quasi-steady state excitation

Gazprom prirutshil ministra / Sergei Tushin

Index Scriptorium Estoniae

Tushin, Sergei

2006-01-01

Peaminister Fredrik Reinfeldti juhitav uus Rootsi valitsus läheb ajalukku kui kõige ebastabiilsem valitsus Euroopas. Välisminister Carl Bildt on keerulises olukorras, kahtlustatakse, et tuntud poliitik ei suuda Moskvaga suheldes jäika joont pidada, kuna seoses naftaäriga omab majanduslikke huvisid Venemaal

Gain claming in single-pass and double-pass L-band erbium-doped fiber amplifiers

International Nuclear Information System (INIS)

Harun, S.W.; Ahmad, H.

2004-01-01

Gain clamping is demonstrated in single-pass and double-pass long wavelength band erbium-doped fiber amplifiers. A C/L-band wavelength division multiplexing coupler is used in single-pass system to generate a laser at 1566 nm. The gain for the amplifier is clamped at 15.5 dB with gain variation of less than 0.2 dB from input signal power of -40 to -14 dBm with almost negligible noise figure penalty. However, the flatness of gain spectrum is slightly degraded due to the un-optimisation of erbium-doped fiber length. The advantage of this configuration is that the oscillating light does not appear at the output of the amplifier. A highly efficient gain-clamped long wavelength band erbium-doped fiber amplifiers with improved noise figure characteristic is demonstrated by simply adding a broadband conventional band fiber Bragg grating in double pass system. The combination of the fiber Bragg grating and optical circulator has created laser in the cavity for gain clamping. By adjusting the power combination of pumps 1 and 2, the clamped gain level can be controlled. The amplifier gain is clamped at 28.1 dB from -40 to -25 dBm with gain variation of less than 0.5 dB by setting the pumps 1 and 2 at 59.5 and 50.6 mW, respectively. The gain is also flat from 1574 nm to 1604 nm with gain variation of less than 3 dB. The corresponding noise figure varies from 5.6 to 7.6 dB, which is 0.8 to 2.6 dB reduced compared to those of unclamped amplifier (Authors)

Fractional-order active fault-tolerant force-position controller design for the legged robots using saturated actuator with unknown bias and gain degradation

Science.gov (United States)

Farid, Yousef; Majd, Vahid Johari; Ehsani-Seresht, Abbas

2018-05-01

In this paper, a novel fault accommodation strategy is proposed for the legged robots subject to the actuator faults including actuation bias and effective gain degradation as well as the actuator saturation. First, the combined dynamics of two coupled subsystems consisting of the dynamics of the legs subsystem and the body subsystem are developed. Then, the interaction of the robot with the environment is formulated as the contact force optimization problem with equality and inequality constraints. The desired force is obtained by a dynamic model. A robust super twisting fault estimator is proposed to precisely estimate the defective torque amplitude of the faulty actuator in finite time. Defining a novel fractional sliding surface, a fractional nonsingular terminal sliding mode control law is developed. Moreover, by introducing a suitable auxiliary system and using its state vector in the designed controller, the proposed fault-tolerant control (FTC) scheme guarantees the finite-time stability of the closed-loop control system. The robustness and finite-time convergence of the proposed control law is established using the Lyapunov stability theory. Finally, numerical simulations are performed on a quadruped robot to demonstrate the stable walking of the robot with and without actuator faults, and actuator saturation constraints, and the results are compared to results with an integer order fault-tolerant controller.

The effect of massage with medium-chain triglyceride oil on weight gain in premature neonates.

Directory of Open Access Journals (Sweden)

Reza Saeadi

2015-02-01

Full Text Available Prematurity and poor weight gaining are important causes for neonatal hospitalization. The present study aimed to investigate the role of medium-chain triglyceride (MCT oil via massage therapy as a supplementary nutritional method on the weight gain of Neonatal Intensive Care Units (NICU-hospitalized neonates. This randomized clinical trial performed among 121 stable premature neonates hospitalized in the NICU of Qaem Educational Hospital, Mashhad, Iran. They were randomly divided into three groups: oil-massage, massage alone and control groups. These groups were compared on the basis of weight gain during a one-week interval. The three groups were matched for sex, mean gestational age, birth weight, head circumference, delivery, and feeding type (P>0.05. The mean weight gain on the 7th day in the oil massage group was 105±1.3gr and 52±0.1gr in the massage group; whereas 54±1.3gr weight loss was observed in the control group. Significant differences were observed between the oil-massage group and the other two groups, respectively (P=0.002 and P=0.000. The findings of this study suggest that transcutaneous feeding with MCT oil massage therapy in premature neonates can result in accelerated weight gain in this age group with no risk of NEC.

The Effects of Embedded Question Type and Locus of Control on Processing Depth, Knowledge Gain, and Attitude Change in a Computer-Based Interactive Video Environment

OpenAIRE

Mitchell, Michael W.

1997-01-01

The differential effectiveness of two types of adjunct embedded questions in facilitating deep processing, increased knowledge gain, and increased positive attitude change was examined in this two-session laboratory study. In session one, subjects completed a measure of locus of control (LOC) orientation, as well as measures of pretest knowledge and attitudes regarding drinking. Two weeks later, stratified assignment was used to place 33 subjects (ages 12 to 15...

Application of matrix singular value properties for evaluating gain and phase margins of multiloop systems. [stability margins for wing flutter suppression and drone lateral attitude control

Science.gov (United States)

Mukhopadhyay, V.; Newsom, J. R.

1982-01-01

A stability margin evaluation method in terms of simultaneous gain and phase changes in all loops of a multiloop system is presented. A universal gain-phase margin evaluation diagram is constructed by generalizing an existing method using matrix singular value properties. Using this diagram and computing the minimum singular value of the system return difference matrix over the operating frequency range, regions of guaranteed stability margins can be obtained. Singular values are computed for a wing flutter suppression and a drone lateral attitude control problem. The numerical results indicate that this method predicts quite conservative stability margins. In the second example if the eigenvalue magnitude is used instead of the singular value, as a measure of nearness to singularity, more realistic stability margins are obtained. However, this relaxed measure generally cannot guarantee global stability.

Intake of Sweets, Snacks and Soft Drinks Predicts Weight Gain in Obese Pregnant Women

DEFF Research Database (Denmark)

Renault, Kristina M; Carlsen, Emma M; Nørgaard, Kirsten

2015-01-01

factors targeted. OBJECTIVE: To evaluate improvements and relevance of different dietary factors targeted with respect to gestational weight gain in a 3-arm Randomised Controlled Trial (n=342) among obese pregnant women with BMI≥30 kg/m2. METHODS: Randomisation 1:1:1 to either hypocaloric Mediterranean...... type of diet and physical activity intervention (D+PA); physical activity intervention alone (PA); or control (C). Diet was assessed at baseline (weeks 11-14) and endpoint (weeks 36-37) using a validated food frequency questionnaire. RESULTS: During the intervention women in the D+PA group...... for limiting gestational weight gain than encouraging strict compliance to more specific diets. TRIAL REGISTRATION: ClinicalTrials.gov NCT01345149....

Adaptation of a fuzzy controller’s scaling gains using genetic algorithms for balancing an inverted pendulum

Directory of Open Access Journals (Sweden)

Duka Adrian-Vasile

2011-12-01

Full Text Available This paper examines the development of a genetic adaptive fuzzy control system for the Inverted Pendulum. The inverted pendulum is a classical problem in Control Engineering, used for testing different control algorithms. The goal is to balance the inverted pendulum in the upright position by controlling the horizontal force applied to its cart. Because it is unstable and has a complicated nonlinear dynamics, the inverted pendulum is a good testbed for the development of nonconventional advanced control techniques. Fuzzy logic technique has been successfully applied to control this type of system, however most of the time the design of the fuzzy controller is done in an ad-hoc manner, and choosing certain parameters (controller gains, membership functions proves difficult. This paper examines the implementation of an adaptive control method based on genetic algorithms (GA, which can be used on-line to produce the adaptation of the fuzzy controller’s gains in order to achieve the stabilization of the pendulum. The performances of the proposed control algorithms are evaluated and shown by means of digital simulation.

Gazprom – Kremls forlængede arm?: Gazprom – A political tool for the Kremlin?

OpenAIRE

Etzerodt, Clemens Ørnstrup; Wessberg, Elisabeth Retz; Crillesen, Emilie Lykke; Hansen, Lasse Friis; Grønborg, Rasmus; Krogh, Astrid Emilie Lavlund; Raun, Julie; Nørgaard, Mads Frid

2011-01-01

This project explores to what extent and how Russia can exploit their natural gas as a power-resource in regard to foreign policy toward the nations of the European Union. Our further analysis is based on the following theories: Realism, neo-realism, Nye’s definition of power and Keohane & Nye’s theory of complex interdependence. Following our analysis we have been able to conclude, that Russia’s supply of natural gas can be defined as a source of power dominated by the term hard power. A...

Gain variation of phototube in the frequency domain at very short term

Energy Technology Data Exchange (ETDEWEB)

Celani, F; Codino, A; Cora, U; Falcioni, R; Felici, G; Levy, G [Istituto Nazionale di Fisica Nucleare, Frascati (Italy); D' Ettorre Piazzoli, B; Mannocchi, G [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Bologna, G; Picchi, P [Turin Univ. (Italy). Ist. di Fisica

1981-11-15

A new very fast pulse generator with injected charge control is used to drive a LED-phototube configuration, reproducing the working conditions of many experiments in high energy physics which make use of fast plastic scintillators. We have studied the behavior of the Phillips XP 2008 phototube operated under such experimental conditions. We find a gain shift vs. frequency that is a function of intensity of the light incident on the PM. For an output ranging between 83 and 450 pC the gain shift at about 33 kHz varies in the range 15-33%.

Weight gain - unintentional

Science.gov (United States)

... diabetes Hormone changes or medical problems can also cause unintentional weight gain. This may be due to: Cushing syndrome Underactive thyroid, or low thyroid (hypothyroidism) Polycystic ovary syndrome Menopause Pregnancy Bloating, or swelling ...

Attentional bias toward high-calorie food-cues and trait motor impulsivity interactively predict weight gain

Directory of Open Access Journals (Sweden)

Adrian Meule

2016-05-01

Full Text Available Strong bottom-up impulses and weak top-down control may interactively lead to overeating and, consequently, weight gain. In the present study, female university freshmen were tested at the start of the first semester and again at the start of the second semester. Attentional bias toward high- or low-calorie food-cues was assessed using a dot-probe paradigm and participants completed the Barratt Impulsiveness Scale . Attentional bias and motor impulsivity interactively predicted change in body mass index: motor impulsivity positively predicted weight gain only when participants showed an attentional bias toward high-calorie food-cues. Attentional and non-planning impulsivity were unrelated to weight change. Results support findings showing that weight gain is prospectively predicted by a combination of weak top-down control (i.e. high impulsivity and strong bottom-up impulses (i.e. high automatic motivational drive toward high-calorie food stimuli. They also highlight the fact that only specific aspects of impulsivity are relevant in eating and weight regulation.

Tensor Product Model Transformation Based Adaptive Integral-Sliding Mode Controller: Equivalent Control Method

Directory of Open Access Journals (Sweden)

Guoliang Zhao

2013-01-01

Full Text Available This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model.

Good maintenance of exercise-induced bone gain with decreased training of female tennis and squash players: a prospective 5-year follow-up study of young and old starters and controls.

Science.gov (United States)

Kontulainen, S; Kannus, P; Haapasalo, H; Sievänen, H; Pasanen, M; Heinonen, A; Oja, P; Vuori, I

2001-02-01

This prospective 5-year follow-up study of 64 adult female racquet sports players and 27 controls assessed the changes in the playing-to-nonplaying arm bone mineral content (BMC) differences to answer three questions: (1) Are training-induced bone gains lost with decreased training? (2) Is the bone response to decreased training different if the playing career has been started before or at puberty rather than after it? (3) Are the possible bone changes related to the changes in training? The players were divided into two groups according to the starting age of their tennis or squash playing. The mean starting age was 10.5 years (SD, 2.2) among the players who had started training before or at menarche (young starters; n = 36) while 26.4 years (SD, 8.0) among those players who had begun training a minimum of 1 year after menarche (old starters; n = 28). At baseline of the 5-year follow-up, the mean age of the young starters was 21.6 years (SD, 7.6) and that of old starters was 39.4 years (SD, 10.5). During the follow-up, the young starters had reduced the average training frequency from 4.7 times a week (2.7) to 1.4 times a week (1.3) and the old starters from 4.0 times a week (1.4) to 2.0 times a week (1.4), respectively. The 5-year follow-up revealed that despite reduced training the exercise-induced bone gain was well maintained in both groups of players regardless of their clearly different starting age of activity and different amount of exercise-induced bone gain. The gain was still 1.3-2.2 times greater in favor of the young starters (at the follow-up, the dominant-to-nondominant arm BMC difference was 22% [8.4] in the humeral shaft of the young starters versus 10% [3.8] in the old starters, and 3.5% [2.4] in controls). In the players, changes in training were only weakly related to changes in the side-to-side BMC difference (r(s) = 0.05-0.34, all NS), and this was true even among the players who had stopped training completely a minimum 1 year before the

Gas electron multiplier (GEM) foil test, repair and effective gain calculation

Science.gov (United States)

Tahir, Muhammad; Zubair, Muhammad; Khan, Tufail A.; Khan, Ashfaq; Malook, Asad

2018-06-01

The focus of my research is based on the gas electron multiplier (GEM) foil test, repairing and effective gain calculation of GEM detector. During my research work define procedure of GEM foil testing short-circuit, detection short-circuits in the foil. Study different ways to remove the short circuits in the foils. Set and define the GEM foil testing procedures in the open air, and with nitrogen gas. Measure the leakage current of the foil and applying different voltages with specified step size. Define the Quality Control (QC) tests and different components of GEM detectors before assembly. Calculate the effective gain of GEM detectors using 109Cd and 55Fe radioactive source.

Gain assisted coherent control of microwave pulse in a one dimensional array of artificial atoms

Science.gov (United States)

Waqas, Mohsin; Ayaz, M. Q.; Waseem, M.; Qamar, Sajid; Qamar, Shahid

2018-06-01

We study the coherent propagation of a microwave pulse through a one-dimensional array of artificial atoms. The scheme is based upon gain assisted propagation of the pulse using two-photon Raman transition in a three-level superconducting artificial atoms (SAAs) coupled to a microwave transmission line. Our results show that the group velocity can be significantly reduced by increasing the Rabi frequency of the pump fields which in turn can lead to an efficient storage of the pulse inside a 1D array of SAAs. Further, the intensity of the transmitted pulse increases with the number of artificial atoms owing to the gain associated with the two-photon Raman transition. Our results also show that the window width decreases for both scattering and negligible scattering cases with the increase in the number of SAAs. The fidelity of the system also remains high even after the passage of the pulse through a large number of SAAs.

CONDITIONS FOR CSR MICROBUNCHING GAIN SUPPRESSION

Energy Technology Data Exchange (ETDEWEB)

Tsai, Cheng Ying [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); di Mitri, Simone [Elettra–Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy

2016-05-01

The coherent synchrotron radiation (CSR) of a high brightness electron beam traversing a series of dipoles, such as transport arcs, may result in phase space degradation. On one hand, the CSR can perturb electron transverse motion in dispersive regions along the beamline, causing emittance growth. On the other hand, the CSR effect on the longitudinal beam dynamics could result in microbunching gain enhancement. For transport arcs, several schemes have been proposed* to suppress the CSR-induced emittance growth. Similarly, several scenarios have been introduced** to suppress CSR-induced microbunching gain, which however mostly aim for linac-based machines. In this paper we try to provide sufficient conditions for suppression of CSR-induced microbunching gain along a transport arc, analogous to*. Several example lattices are presented, with the relevant microbunching analyses carried out by our semi-analytical Vlasov solver***. The simulation results show that lattices satisfying the proposed conditions indeed have microbunching gain suppressed. We expect this analysis can shed light on lattice design approach that could suppress the CSR-induced microbunching gain.

Unequal Gain of Equal Resources across Racial Groups.

Science.gov (United States)

Assari, Shervin

2017-08-05

The health effects of economic resources (eg, education, employment, and living place) and psychological assets (eg, self-efficacy, perceived control over life, anger control, and emotions) are well-known. This article summarizes the results of a growing body of evidence documenting Blacks' diminished return, defined as a systematically smaller health gain from economic resources and psychological assets for Blacks in comparison to Whites. Due to structural barriers that Blacks face in their daily lives, the very same resources and assets generate smaller health gain for Blacks compared to Whites. Even in the presence of equal access to resources and assets, such unequal health gain constantly generates a racial health gap between Blacks and Whites in the United States. In this paper, a number of public policies are recommended based on these findings. First and foremost, public policies should not merely focus on equalizing access to resources and assets, but also reduce the societal and structural barriers that hinder Blacks. Policy solutions should aim to reduce various manifestations of structural racism including but not limited to differential pay, residential segregation, lower quality of education, and crime in Black and urban communities. As income was not found to follow the same pattern demonstrated for other resources and assets (ie, income generated similar decline in risk of mortality for Whites and Blacks), policies that enforce equal income and increase minimum wage for marginalized populations are essential. Improving quality of education of youth and employability of young adults will enable Blacks to compete for high paying jobs. Policies that reduce racism and discrimination in the labor market are also needed. Without such policies, it will be very difficult, if not impossible, to eliminate the sustained racial health gap in the United States. © 2018 The Author(s); Published by Kerman University of Medical Sciences. This is an open

Application of multi-objective controller to optimal tuning of PID gains for a hydraulic turbine regulating system using adaptive grid particle swam optimization.

Science.gov (United States)

Chen, Zhihuan; Yuan, Yanbin; Yuan, Xiaohui; Huang, Yuehua; Li, Xianshan; Li, Wenwu

2015-05-01

A hydraulic turbine regulating system (HTRS) is one of the most important components of hydropower plant, which plays a key role in maintaining safety, stability and economical operation of hydro-electrical installations. At present, the conventional PID controller is widely applied in the HTRS system for its practicability and robustness, and the primary problem with respect to this control law is how to optimally tune the parameters, i.e. the determination of PID controller gains for satisfactory performance. In this paper, a kind of multi-objective evolutionary algorithms, named adaptive grid particle swarm optimization (AGPSO) is applied to solve the PID gains tuning problem of the HTRS system. This newly AGPSO optimized method, which differs from a traditional one-single objective optimization method, is designed to take care of settling time and overshoot level simultaneously, in which a set of non-inferior alternatives solutions (i.e. Pareto solution) is generated. Furthermore, a fuzzy-based membership value assignment method is employed to choose the best compromise solution from the obtained Pareto set. An illustrative example associated with the best compromise solution for parameter tuning of the nonlinear HTRS system is introduced to verify the feasibility and the effectiveness of the proposed AGPSO-based optimization approach, as compared with two another prominent multi-objective algorithms, i.e. Non-dominated Sorting Genetic Algorithm II (NSGAII) and Strength Pareto Evolutionary Algorithm II (SPEAII), for the quality and diversity of obtained Pareto solutions set. Consequently, simulation results show that this AGPSO optimized approach outperforms than compared methods with higher efficiency and better quality no matter whether the HTRS system works under unload or load conditions. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Hea on elada Venemaal rahas supleva Gazpromi töötajana / Jaanus Piirsalu

Index Scriptorium Estoniae

Piirsalu, Jaanus, 1973-

2010-01-01

Gazpromi kontserni suurimast tütarettevõttest Jamali Neenetsi ringkonnas Gazprom Dobõtša Urengoist, töötajate palgast, nn. põhjatoetusest, puhkusest; ringkonna-poolsest noorte edasiõppimise toetamisest. Urengoi linnast

Design and optimization of fuzzy-PID controller for the nuclear reactor power control

International Nuclear Information System (INIS)

Liu Cheng; Peng Jinfeng; Zhao Fuyu; Li Chong

2009-01-01

This paper introduces a fuzzy proportional-integral-derivative (fuzzy-PID) control strategy, and applies it to the nuclear reactor power control system. At the fuzzy-PID control strategy, the fuzzy logic controller (FLC) is exploited to extend the finite sets of PID gains to the possible combinations of PID gains in stable region and the genetic algorithm to improve the 'extending' precision through quadratic optimization for the membership function (MF) of the FLC. Thus the FLC tunes the gains of PID controller to adapt the model changing with the power. The fuzzy-PID has been designed and simulated to control the reactor power. The simulation results show the favorable performance of the fuzzy-PID controller.

FEL gain optimisation and spontaneous radiation

Energy Technology Data Exchange (ETDEWEB)

Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

1995-12-31

Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

Artificial emotion triggered stochastic behavior transitions with motivational gain effects for multi-objective robot tasks

Science.gov (United States)

Dağlarli, Evren; Temeltaş, Hakan

2007-04-01

This paper presents artificial emotional system based autonomous robot control architecture. Hidden Markov model developed as mathematical background for stochastic emotional and behavior transitions. Motivation module of architecture considered as behavioral gain effect generator for achieving multi-objective robot tasks. According to emotional and behavioral state transition probabilities, artificial emotions determine sequences of behaviors. Also motivational gain effects of proposed architecture can be observed on the executing behaviors during simulation.

Information Technology How Leading Firms Use It to Gain an Advantage

CERN Document Server

Rapp, William V

2002-01-01

Focuses on the strategic principles fundamental to using information technology to gain market control. This book provides case examples of how to use IT. It is designed to help managers struggling with how to harness the information revolution. It describes how non-information technology companies are employing strategic principles and using it.

Adult weight gain and colorectal adenomas-a systematic review and meta-analysis.

Science.gov (United States)

Schlesinger, S; Aleksandrova, K; Abar, L; Vieria, A R; Vingeliene, S; Polemiti, E; Stevens, C A T; Greenwood, D C; Chan, D S M; Aune, D; Norat, T

2017-06-01

Colorectal adenomas are known as precursors for the majority of colorectal carcinomas. While weight gain during adulthood has been identified as a risk factor for colorectal cancer, the association is less clear for colorectal adenomas. We conducted a systematic review and meta-analysis to quantify the evidence on this association. We searched Medline up to September 2016 to identify observational (prospective, cross-sectional and retrospective) studies on weight gain during adulthood and colorectal adenoma occurrence and recurrence. We conducted meta-analysis on high weight gain versus stable weight, linear and non-linear dose-response meta-analyses to analyze the association. Summary odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using a random effects model. For colorectal adenoma occurrence, the summary OR was 1.39 (95% CI: 1.17-1.65; I2: 43%, N = 9 studies, cases = 5507) comparing high (midpoint: 17.4 kg) versus stable weight gain during adulthood and with each 5 kg weight gain the odds increased by 7% (2%-11%; I2: 65%, N = 7 studies). Although there was indication of non-linearity (Pnon-linearity firm conclusions. Even a small amount of adult weight gain was related to a higher odds of colorectal adenoma occurrence. Our findings add to the benefits of weight control in adulthood regarding colorectal adenoma occurrence, which might be relevant for early prevention of colorectal cancer. © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

24 CFR 3280.507 - Comfort heat gain.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Comfort heat gain. 3280.507 Section... gain. Information necessary to calculate the home cooling load shall be provided as specified in this part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat loss...

Is weight gain really a catalyst for broader recovery?: The impact of weight gain on psychological symptoms in the treatment of adolescent anorexia nervosa.

Science.gov (United States)

Accurso, Erin C; Ciao, Anna C; Fitzsimmons-Craft, Ellen E; Lock, James D; Le Grange, Daniel

2014-05-01

The main aims of this study were to describe change in psychological outcomes for adolescents with anorexia nervosa across two treatments, and to explore predictors of change, including baseline demographic and clinical characteristics, as well as weight gain over time. Participants were 121 adolescents with anorexia nervosa from a two-site (Chicago and Stanford) randomized controlled trial who received either family-based treatment or individual adolescent supportive psychotherapy. Psychological symptoms (i.e., eating disorder psychopathology, depressive symptoms, and self-esteem) were assessed at baseline, end of treatment, 6-month, and 12-month follow-up. Conditional multilevel growth models were used to test for predictors of slope for each outcome. Most psychological symptoms improved significantly from baseline to 12 month follow-up, regardless of treatment type. Depressive symptoms and dietary restraint were most improved, weight and shape concerns were least improved, and self-esteem was not at all improved. Weight gain emerged as a significant predictor of improved eating disorder pathology, with earlier weight gain having a greater impact on symptom improvement than later weight gain. Adolescents who presented with more severe, complex, and enduring clinical presentations (i.e., longer duration of illness, greater eating disorder pathology, binge-eating/purging subtype) also appeared to benefit more psychologically from treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bolshoi vopross : Dolzhnõ li mõ bojatsja kontrolja Kremlja nad energetitsheskim snabzhenijem Jevropõ?

Index Scriptorium Estoniae

2006-01-01

Venemaa valitsuse poolt kontrollitav Gazprom kuulub maailma suurimate maagaasi tootjate hulka ning rahuldab 20 protsenti maailma nõudlusest, kontserni tähtsusest Lääneriikide ja Venemaa jaoks. Gazpromi huvist Suurbritannia firma Centrica vastu

Gazpromile oli eelmine aasta rekordiliselt hea / Andrus Karnau

Index Scriptorium Estoniae

Karnau, Andrus

2007-01-01

Vene riikliku gaasifirma Gazprom eksporditulud kasvasid 2006. aastal 43%, kasvas ka kodumaine gaasimüük. Eesti Gaasi käibe kasvust ja gaasihinna tõusust. Riigikogu väliskomisjoni aseesimehe Marko Mihkelsoni hinnang

Brain Network Modularity Predicts Exercise-Related Executive Function Gains in Older Adults.

Science.gov (United States)

Baniqued, Pauline L; Gallen, Courtney L; Voss, Michelle W; Burzynska, Agnieszka Z; Wong, Chelsea N; Cooke, Gillian E; Duffy, Kristin; Fanning, Jason; Ehlers, Diane K; Salerno, Elizabeth A; Aguiñaga, Susan; McAuley, Edward; Kramer, Arthur F; D'Esposito, Mark

2017-01-01

Recent work suggests that the brain can be conceptualized as a network comprised of groups of sub-networks or modules. The extent of segregation between modules can be quantified with a modularity metric, where networks with high modularity have dense connections within modules and sparser connections between modules. Previous work has shown that higher modularity predicts greater improvements after cognitive training in patients with traumatic brain injury and in healthy older and young adults. It is not known, however, whether modularity can also predict cognitive gains after a physical exercise intervention. Here, we quantified modularity in older adults ( N = 128, mean age = 64.74) who underwent one of the following interventions for 6 months (NCT01472744 on ClinicalTrials.gov): (1) aerobic exercise in the form of brisk walking (Walk), (2) aerobic exercise in the form of brisk walking plus nutritional supplement (Walk+), (3) stretching, strengthening and stability (SSS), or (4) dance instruction. After the intervention, the Walk, Walk+ and SSS groups showed gains in cardiorespiratory fitness (CRF), with larger effects in both walking groups compared to the SSS and Dance groups. The Walk, Walk+ and SSS groups also improved in executive function (EF) as measured by reasoning, working memory, and task-switching tests. In the Walk, Walk+, and SSS groups that improved in EF, higher baseline modularity was positively related to EF gains, even after controlling for age, in-scanner motion and baseline EF. No relationship between modularity and EF gains was observed in the Dance group, which did not show training-related gains in CRF or EF control. These results are consistent with previous studies demonstrating that individuals with a more modular brain network organization are more responsive to cognitive training. These findings suggest that the predictive power of modularity may be generalizable across interventions aimed to enhance aspects of cognition and that

Brain Network Modularity Predicts Exercise-Related Executive Function Gains in Older Adults

Directory of Open Access Journals (Sweden)

Pauline L. Baniqued

2018-01-01

Full Text Available Recent work suggests that the brain can be conceptualized as a network comprised of groups of sub-networks or modules. The extent of segregation between modules can be quantified with a modularity metric, where networks with high modularity have dense connections within modules and sparser connections between modules. Previous work has shown that higher modularity predicts greater improvements after cognitive training in patients with traumatic brain injury and in healthy older and young adults. It is not known, however, whether modularity can also predict cognitive gains after a physical exercise intervention. Here, we quantified modularity in older adults (N = 128, mean age = 64.74 who underwent one of the following interventions for 6 months (NCT01472744 on ClinicalTrials.gov: (1 aerobic exercise in the form of brisk walking (Walk, (2 aerobic exercise in the form of brisk walking plus nutritional supplement (Walk+, (3 stretching, strengthening and stability (SSS, or (4 dance instruction. After the intervention, the Walk, Walk+ and SSS groups showed gains in cardiorespiratory fitness (CRF, with larger effects in both walking groups compared to the SSS and Dance groups. The Walk, Walk+ and SSS groups also improved in executive function (EF as measured by reasoning, working memory, and task-switching tests. In the Walk, Walk+, and SSS groups that improved in EF, higher baseline modularity was positively related to EF gains, even after controlling for age, in-scanner motion and baseline EF. No relationship between modularity and EF gains was observed in the Dance group, which did not show training-related gains in CRF or EF control. These results are consistent with previous studies demonstrating that individuals with a more modular brain network organization are more responsive to cognitive training. These findings suggest that the predictive power of modularity may be generalizable across interventions aimed to enhance aspects of cognition and

Russia needs a strong counterpart

International Nuclear Information System (INIS)

Slovak, K.; Marcan, P.

2008-01-01

In this paper an interview with the head of OMV, Wolfgang Ruttenstorfer is published. There is extract from this interview: Q: There have been attempts to take over MOL for a quite long time. Do you think you can still succeed? Since the beginning we kept saying that this would not happen from one day to another. But it may take two to three years. But we are positive that it is justified. Q: Resistance from MOL and the Hungarian government is strong. We have tried to persuade the Hungarian government. We offered them a split company management. A part of the management would be in Budapest. We would locate the management of the largest division - the refinery, there. And of course only the best could be part of the management. We would not nominate people according to their nationality, it would not matter whether the person was Austrian, Hungarian or Slovak. We want a Central European company, not Hungarian, Romanian or Slovak company. Q: Would the transaction still be attractive if, because of pressure exercised by Brussels, you had to sell Slovnaft or your refinery in Szazhalobatta? We do not intend to sell any refineries. Q: Rumours are spreading that the Commission may ask you to sell a refinery? We do not want to speculate. Let us wait and see what happens. We do not want to sell refineries. Q: It is said that OMV is coordinating or at least consulting its attempts to acquire MOL with Gazprom. There are many rumours in Central Europe. But I can tell you this is not true. We are interested in this merger because we feel the increasing pressure exercised by Kazakhstan and Russia. We, of course, have a good relationship with Gazprom which we have had enjoyed for over forty years. As indeed Slovakia has. Q: A few weeks ago Austrian daily Wirtschaftsblatt published an article about Gazprom's interest in OMV shares. That is gossip that is more than ten years' old. Similarly to the rumours that Gazprom is a shareholder of MOL. There are no negotiations with Gazprom

Analysis of reactor power behaviour using estimation of period for the gain adaptation in a state feedback controller

International Nuclear Information System (INIS)

Benitez R, J.S.; Perez C, J.H.; Rivero G, T.

2008-01-01

In this paper a novel procedure for power regulation in a TRIGA Mark III nuclear reactor is presented. The control scheme combines state variable feedback with a first order predictor, which is incorporated to speed up the power response of the reactor without exceeding the safety requirement imposed by the reactor period. The simulation results using the proposed control strategy attains different values of steady-state power from different values of initial power in short time, complying at all times with the safety restriction imposed on the reactor period. The predictor, derived from the theory of first order numerical integration, produces very good results during the ascent of power. These results include a fast response and independence of the wide variety of potential operating conditions something not easy and even impossible to obtain with other procedures. By using this control scheme, the reactor period is maintained within safety limits during the start up of the reactor, which is normally the operating condition where an occurrence of a period scram is common. However, the predictor can not be used when the power is reaching the desired power level because the instantaneous power increases far above the desired level. Thus, when the power increases above certain power level, the state feedback gain is set constant to a predefined value. This causes some oscillations that decrease in a few seconds. Afterwards, the power response smoothly approaches, with a small overshoot, the desired power. This constraint on the use of the predictor prevents the unbounded increase of the neutron power. The control law proposed requires all the system's state variables. Since only the neutron power is available, it is necessary the estimation of the non measurable states. The key issue of the existence of a solution to this problem has been previously considered. One of the conclusions is that the point kinetic equations are observable under certain restrictions on

Spontaneous indices are inconsistent with arterial baroreflex gain.

Science.gov (United States)

Lipman, Ruth D; Salisbury, Julie K; Taylor, J Andrew

2003-10-01

Spontaneously occurring, parallel fluctuations in arterial pressure and heart period are frequently used as indices of baroreflex function. Despite the convenience of spontaneous indices, their relation to the arterial baroreflex remains unclear. Therefore, in 97 volunteers, we derived 5 proposed indices (sequence method, alpha-index, transfer function, low-frequency transfer function, and impulse response function), compared them with arterial baroreflex gain (by the modified Oxford pharmacologic technique), and examined their relation to carotid distensibility and respiratory sinus arrhythmia. The subjects comprised men and women (n=41) aged 25 to 86 years, 30% of whom had established coronary artery disease. Generally, the indices were correlated with each other (except alpha-index and low-frequency transfer function) and with baroreflex gain. However, the Bland-Altman method demonstrated that the spontaneous indices had limits of agreement as large as the baroreflex gain itself. Even in individuals within the lowest tertile of baroreflex gain for whom baroreflex gain appears to be the most clinically relevant, spontaneous indices failed to relate to baroreflex gain. In fact, for these individuals, there was no correlation between any index and baroreflex gain. Forward stepwise linear regression showed that all spontaneous indices and baroreflex gain were related to respiratory sinus arrhythmia, but only baroreflex gain was related to carotid distensibility. Therefore, these data suggest that spontaneous indices are inadequate estimates of gain and are inconsistent with arterial baroreflex function.

Metformin in prevention and treatment of antipsychotic induced weight gain: a systematic review and meta-analysis.

Science.gov (United States)

de Silva, Varuni Asanka; Suraweera, Chathurie; Ratnatunga, Suhashini S; Dayabandara, Madhubashinee; Wanniarachchi, Nimali; Hanwella, Raveen

2016-10-03

Most antipsychotics are associated with weight gain and other metabolic complications. Several randomized trials have shown metformin to be effective, but this still hasn't been included in clinical guidelines on managing antipsychotic induced weight gain. All double blind placebo controlled trials assessing the efficacy of metformin in the treatment of antipsychotic induced weight gain were included. Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE were searched for the period January 2000-December 2015. Meta-analysis was carried out using the random effects model. Meta analysis of 12 published studies with a total of 743 patients found that in patients treated with antipsychotics, metformin treatment resulted in significantly better anthropometric and metabolic parameters than placebo. The mean change in weight was -3.27 kg (95 % CI -4.66 to -1.89) (Z = 4.64, p resistance index [-1.49 (95 % CI -2.40 to -0.59)] but not fasting blood sugar [-2.48 mg/dl (95 % CI -5.54 to 0.57]. This meta-analysis confirms that metformin is effective in treating antipsychotic induced weight gain in patients with schizophrenia or schizoaffective disorder.

Liberalization of Russian gas exports: benefits and challenges

Directory of Open Access Journals (Sweden)

Yakunina Alla

2017-01-01

Full Text Available Russian gas export liberalization has been discussed throughout the post-Soviet period. Recently, the number of Gazprom’s export monopoly advocates has been diminishing as a result of dramatic changes in both European and Russian gas markets, which are: increasing international trade in liquefied natural gas; the EU movement from long-term contracts to the commodity markets and hub pricing; substantially increased share of the non-Gazprom gas suppliers at the Russian domestic market. Although there is a potential risk of price decrease in the EU gas market in the case of the Gazprom export monopoly abolition, the benefits of the Russian gas export liberalization would be greater than losses. The gas resource base and the cost of pipeline gas production would allow Russia to improve its positions in the world market.

Insulin detemir attenuates food intake, body weight gain and fat mass gain in diet-induced obese Sprague-Dawley rats.

Science.gov (United States)

Rojas, J M; Printz, R L; Niswender, K D

2011-07-04

Initiation and intensification of insulin therapy commonly causes weight gain, a barrier to therapy. A contrasting body of evidence indicates that insulin functions as an adiposity negative feedback signal and reduces food intake, weight gain and adiposity via action in the central nervous system. Basal insulin analogs, detemir (Det) and glargine (Glar), have been associated with less hypoglycemia compared with neutral protamine hagedorn insulin, and Det with less weight gain, especially in patients with higher body mass index (BMI). We sought to determine whether insulin therapy per se causes body weight and fat mass gain when delivered via a clinically relevant subcutaneous (SC) route in the absence of hypoglycemia and glycosuria in non-diabetic lean and diet-induced obese rats. Rats were exposed to either a low-fat diet (LFD; 13.5% fat) or high-fat diet (HFD; 60% fat), and received Det (0.5 U kg(-1)), Glar (0.2 U kg(-1)) or vehicle (Veh) SC once daily for 4 weeks. These dosages of insulin were equipotent in rats with respect to blood-glucose concentration and did not induce hypoglycemia. As predicted by current models of energy homeostasis, neither insulin Det nor Glar therapy affected food intake and weight gain in LFD rats. Det treatment significantly attenuated food intake, body weight gain and fat mass gain relative to the Glar and Veh in high-fat fed animals, mirroring observations in humans. That neither insulin group gained excess weight, suggests weight gain with SC basal insulin therapy may not be inevitable. Our data further suggest that Det possesses a unique property to attenuate the development of obesity associated with a HFD.

Obesity, weight gain, and ovarian cancer risk in African American women.

Science.gov (United States)

Bandera, Elisa V; Qin, Bo; Moorman, Patricia G; Alberg, Anthony J; Barnholtz-Sloan, Jill S; Bondy, Melissa; Cote, Michele L; Funkhouser, Ellen; Peters, Edward S; Schwartz, Ann G; Terry, Paul; Schildkraut, Joellen M

2016-08-01

Although there is growing evidence that higher adiposity increases ovarian cancer risk, little is known about its impact in African American (AA) women, the racial/ethnic group with the highest prevalence of obesity. We evaluated the impact of body mass index (BMI) 1 year before diagnosis and weight gain since age 18 years on ovarian cancer risk in a population-based case-control study in AA women in 11 geographical areas in the US. Cases (n = 492) and age and site matched controls (n = 696) were identified through rapid case ascertainment and random-digit-dialing, respectively. Information was collected on demographic and lifestyle factors, including self-reported height, weight at age 18 and weight 1 year before diagnosis/interview. Multivariable logistic regression was used to compute odds ratios (OR) and 95% confidence intervals (CI), adjusting for potential covariates. Obese women had elevated ovarian cancer risk, particularly for BMI ≥ 40 kg/m(2) compared to BMI Obesity and excessive adult weight gain may increase ovarian cancer risk in post-menopausal AA women. © 2016 UICC.

Approach to interior design for passive direct gain solar homes

Energy Technology Data Exchange (ETDEWEB)

Kachadorian, C.C.

1980-01-01

In response to requests from buyers and builders of direct gain passive solar homes interior design criteria either specific to, or emphasized by, passive solar buildings are investigated. Problems of high sunlight penetration, secondary illumination, material selection, sound control and psychology are approached. Material deterioration, fading, glare, noise, and a sense of spacial confinement can be minimized, contributing to the appeal and saleability of passive solar homes.

[Association between mothers' body mass index before pregnancy or weight gain during pregnancy and autism in children].

Science.gov (United States)

Ling, Ziyu; Wang, Jianmin; Li, Xia; Zhong, Yan; Qin, Yuanyuan; Xie, Shengnan; Yang, Senbei; Zhang, Jing

2015-09-01

To explore the relationship between mothers' body mass index (BMI) before pregnancy or weight gain during pregnancy and autism in children. From 2013 to 2014, the 181 children with autism and 181 healthy children matched by sex and age from same area were included in this study. According to mothers' BMI before pregnancy, the selected cases were divided into 3 groups: low, normal and high group. Then 3 groups were divided into 3 subgroups based on mother' s weight gain during pregnancy: low, normal and high group, according to the recommendations of Institute of Medicine. Logistic regression analysis and χ(2) test were conducted with SPSS 18.0 software to analysis the relationship between mothers' BMI before pregnancy or weight gain during pregnancy and autism in children. The age and sex distributions of case group and control group were consistent (χ(2)=0.434, P>0.05). The mothers' BMI before pregnancy of case group was higher than that of control group (χ(2)=9.580, Pautism in children. Logistic regression analysis showed that mothers' BMI before pregnancy (unadjusted OR=1.89, 95% CI: 1.26-2.85, adjusted OR=1.52, 95% CI: 1.19-2.27) and weight gain during pregnancy were the risk factors for autism in children (unadjusted OR=1.63, 95% CI: 1.08-1.25, adjusted OR=1.64, 95% CI: 1.21-2.21). Overweight or obesity before pregnancy and excessive weight gain during pregnancy were associated with autism in children, suggesting that women who plan to be pregnant should pay attention to body weight control.

Dynamics of nonlinear feedback control

NARCIS (Netherlands)

Snippe, H.P.; Hateren, J.H. van

Feedback control in neural systems is ubiquitous. Here we study the mathematics of nonlinear feedback control. We compare models in which the input is multiplied by a dynamic gain (multiplicative control) with models in which the input is divided by a dynamic attenuation (divisive control). The gain

Changes in working conditions and major weight gain among normal- and overweight midlife employees.

Science.gov (United States)

Niskanen, Riikka; Holstila, Ansku; Rahkonen, Ossi; Lallukka, Tea

2017-11-01

Objectives We aimed to examine the association between changes in psychosocial working conditions and major weight gain among midlife women and men. Furthermore, we examined the associations separately among normal- and overweight participants. Methods We used survey data among employees of the City of Helsinki, Finland, from 2000-2002 (phase 1, N=8960), 2007 (phase 2, N=7332), and 2012 (phase 3, N=6814), with a final study sample of 4369 participants. We examined changes in job strain, job demands, and job control from phase 1 to 2. We defined major weight gain as ≥10% weight gain between phases 1 and 3 based on self-reported weight (kg). We performed logistic regression analysis adjusting for baseline age, marital status, and occupational class, stratifying by gender and by baseline body mass index. Results Job demands among both genders and job strain among women was associated with major weight gain. Furthermore, increased job demands [odds ratio (OR) 1.52, 95% CI 1.05-2.20] or increased job strain (OR 1.53, 95% CI 1.11-2.11) was associated with major weight gain among overweight women. Normal-weight men reporting decreased job demands (OR 4.11, 95% CI 1.48-11.40) and overweight men reporting increasing job demands (OR 2.93, 95% CI 1.26-6.82) exhibited higher odds of major weight gain. Conclusions Associations between working conditions and weight gain appeared primarily weak. Our study suggests that overweight individuals might be at a higher risk of weight gain when facing psychosocial strain in the workplace.

Fighting for and losing or gaining control in life.

Science.gov (United States)

Theorell, T

1997-01-01

In JP Henry's work, fighting for and losing control were important concepts in the interpretation of energy mobilization in psychosocial conditions. Attachment and support were important protective and salutogenic factors. These concepts have been applied in a series of epidemiological and psychophysiological real life studies. Job conditions which force the worker to mobilize energy and concomitantly inhibit anabolism could be identified at least partly by means of the demand-control-support model originally proposed by Karasek. The most adverse conditions at work arise when psychological demands are high and at the same time the decision latitude is low. This combination is associated with changes in the regulation of endocrine parameters as well as with increased morbidity--heart disease, functional gastrointestinal symptoms and musculoskeletal disorders. Examples of studies of physiological correlates of psychosocial processes leading to fight for control are also described from outside work activities.

Aastavahetuse gaasi-deja vu / Igor Taro

Index Scriptorium Estoniae

Taro, Igor

2006-01-01

Venemaa gaasiettevõtte Gazprom ja Valgevene gaasiläbirääkimised gaasihinna ja transiidilepingu üle on ummikusse jooksnud, mistõttu võib 2007. aasta algusest Euroopa gaasita jätta. Kaart: Gaasitransiit Euroopasse

Comparison of intelligent fuzzy based AGC coordinated PID controlled and PSS controlled AVR system

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, V. [Department of Electrical Engineering, Asansol Engineering College, Asansol, West Bengal (India); Ghoshal, S.P. [Department of Electrical Engineering, National Institute of Technology, Durgapur, West Bengal (India)

2007-11-15

This paper attempts to investigate the performance of intelligent fuzzy based coordinated control of the Automatic Generation Control (AGC) loop and the excitation loop equipped with Proportional Integral Derivative (PID) controlled Automatic Voltage Regulator (AVR) system and Power System Stabilizer (PSS) controlled AVR system. The work establishes that PSS controlled AVR system is much more robust in dynamic performance of the system over a wide range of system operating configurations. Thus, it is revealed that PSS equipped AVR is much more superior than PID equipped AVR in damping the oscillation resulting in improved transient response. The paper utilizes a novel class of Particle Swarm Optimization (PSO) termed as Craziness based Particle Swarm Optimization (CRPSO) as optimizing tool to get optimal tuning of PSS parameters as well as the gains of PID controllers. For on-line, off-nominal operating conditions Takagi Sugeno Fuzzy Logic (TSFL) has been applied to obtain the off-nominal optimal gains of PID controllers and parameters of PSS. Implementation of TSFL helps to achieve very fast dynamic response. Fourth order model of generator with AVR and high gain thyristor excitation system is considered for PSS controlled system while normal gain exciter is considered for PID controlled system. Simulation study also reveals that with high gain exciter, PID control is not at all effective. Transient responses are achieved by using modal analysis. (author)

[Corporal image and pregnancy: A look at psychometric properties of the French translation of the Pregnancy and Weigh Gain Attitude Scale].

Science.gov (United States)

Rousseau, A; Bouillon, A; Lefebvre, L; Séjourné, N; Denis, A

2016-08-01

Body dissatisfaction among pregnant women can provoke behaviors to control weight gain and make them more vulnerable to eating disorders. Body dissatisfaction and strategies to control weight during pregnancy can have many consequences for both the mother and baby. Excessive weight gain may cause complications during childbirth and, reciprocally, a too weak weight gain could be associated with the risk of having a baby with a very low birth weight. Thus, it appears important to have a tool to detect these body image disorders in this population. As far as we know, no French-speaking tool exists, and the objective of this study was to investigate the psychometric properties of the French translation of the Pregnancy and Weight Gain Attitude Scale (PWGAS), which assesses the attitudes about weight gain during pregnancy. The sample consisted of 553 women (29.32±4.82 years) in their third trimester of pregnancy. Participants were volunteer women recruited in hospitals during obstetric consultation. All participants completed an anamnestic questionnaire, the PWGAS and a questionnaire assessing body dissatisfaction (Body Shape Questionnaire [BSQ]). The PWGAS, in its original version, includes 18 items and consists of four subscales: Positive Pregnancy Body Image; Negative Pregnancy Body Image; Indifference toward Weight Gain and Weight Gain Restrictive Behaviors. The instrument was translated and verified by expert translators. Confirmatory factor analysis of the original version showed fit indices below recommended limits. An exploratory factor analysis on the PWGAS revealed the existence of five factors: "Fear about weight gain" (4 items); "Absence of weight gain preoccupation" (2 items); "Positive attitudes about weight gain" (4 items); "Feeling overwhelmed by weight gain" (3 items); and "Control over weight gain" (3 items). The goodness-of-fit of the five-factor model was satisfactory. The PWGAS (total and factors) is negatively correlated with the BSQ demonstrating

Stability Assessment and Tuning of an Adaptively Augmented Classical Controller for Launch Vehicle Flight Control

Science.gov (United States)

VanZwieten, Tannen; Zhu, J. Jim; Adami, Tony; Berry, Kyle; Grammar, Alex; Orr, Jeb S.; Best, Eric A.

2014-01-01

Recently, a robust and practical adaptive control scheme for launch vehicles [ [1] has been introduced. It augments a classical controller with a real-time loop-gain adaptation, and it is therefore called Adaptive Augmentation Control (AAC). The loop-gain will be increased from the nominal design when the tracking error between the (filtered) output and the (filtered) command trajectory is large; whereas it will be decreased when excitation of flex or sloshing modes are detected. There is a need to determine the range and rate of the loop-gain adaptation in order to retain (exponential) stability, which is critical in vehicle operation, and to develop some theoretically based heuristic tuning methods for the adaptive law gain parameters. The classical launch vehicle flight controller design technics are based on gain-scheduling, whereby the launch vehicle dynamics model is linearized at selected operating points along the nominal tracking command trajectory, and Linear Time-Invariant (LTI) controller design techniques are employed to ensure asymptotic stability of the tracking error dynamics, typically by meeting some prescribed Gain Margin (GM) and Phase Margin (PM) specifications. The controller gains at the design points are then scheduled, tuned and sometimes interpolated to achieve good performance and stability robustness under external disturbances (e.g. winds) and structural perturbations (e.g. vehicle modeling errors). While the GM does give a bound for loop-gain variation without losing stability, it is for constant dispersions of the loop-gain because the GM is based on frequency-domain analysis, which is applicable only for LTI systems. The real-time adaptive loop-gain variation of the AAC effectively renders the closed-loop system a time-varying system, for which it is well-known that the LTI system stability criterion is neither necessary nor sufficient when applying to a Linear Time-Varying (LTV) system in a frozen-time fashion. Therefore, a

Working-memory training in younger and older adults: Training gains, transfer, and maintenance

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Yvonne eBrehmer

2012-03-01

Full Text Available Working memory (WM, a key determinant of many higher-order cognitive functions, declines in old age. Current research attempts to develop process-specific WM training procedures, which may lead to general cognitive improvement. Adaptivity of the training as well as the comparison of training gains to performance changes of an active control group are key factors in evaluating the effectiveness of a specific training program. In the present study, 55 younger adults (20-30 years of age and 45 older adults (60-70 years of age received five weeks of computerized training on various spatial and verbal WM tasks. Half of the sample received adaptive training (i.e., individually adjusted task difficulty, whereas the other half worked on the same task material but on a low task difficulty level (active controls. Performance was assessed using criterion, near-transfer, and far-transfer tasks before training, after 5 weeks of intervention, as well as after a 3-month follow-up interval. Results indicate that (a adaptive training generally led to larger training gains than low-level practice, (b training and transfer gains were somewhat greater for younger than for older adults in some tasks, but comparable across age groups in other tasks, (c far transfer was observed to a test on sustained attention and for a self-rating scale on cognitive functioning in daily life for both young and old, and (d training gains and transfer effects were maintained across the 3-month follow-up interval across age.

The effect of holiday weight gain on body weight.

Science.gov (United States)

Schoeller, Dale A

2014-07-01

The topic of holiday weight gain has been a frequent subject of the lay media; however, scientific interest has only been recent. Multiple studies in Western societies have reported average weight gains among adults during the period between mid-November and mid-January that were about 0.5 kg. The range in individual weight changes was large, however, and the already overweight and obese gain more weight than those who are healthy weight. When the average gain across the year was also measured, the holiday weight was the major contributor to annual excess weight gain. Efforts patterned to increase awareness to energy balance and body weight have been shown to be successful at reducing such gain. An exception to holiday weight gain being a major contributor to annual excess gain has been children, in whom summer weight gains have been observed to be the major contributor to average excess weight gain. Copyright © 2014 Elsevier Inc. All rights reserved.

The Effect of Ranitidine on Olanzapine-Induced Weight Gain

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Fatemeh Ranjbar

2013-01-01

Full Text Available Induced weight gain is a disturbing side effect of Olanzapine that affects the quality of life in psychotic patients. The aim of this study was to assess the efficacy of Ranitidine in attenuating or preventing Olanzapine-induced weight gain. A parallel 2-arm clinical trial was done on 52 patients with schizophrenia, schizoaffective and schizophreniform disorders who received Olanzapine for the first time. All these were first-episode admitted patients. They were randomly allocated to receive either Ranitidine or placebo. The trend of body mass index (BMI was compared between groups over 16-week course of treatment. Mean weight was 62.3 (SD: 9.6 kg at baseline. Thirty-three subjects (63.5% had positive family history of obesity. The average BMI increment was 1.1 for Ranitidine group and 2.4 for the placebo group. The multivariate analysis showed this effect to be independent of sex, family history of obesity, and baseline BMI value. The longitudinal modeling after controlling for baseline values failed to show the whole trend slope to be different. Although the slight change in trend’s slope puts forward a hypothesis that combined use of Ranitidine and Olanzapine may attenuate the weight gain long run, this needs to be retested in future larger scale long-term studies. This trial is registered with IRCT.ir 201009112181N5.

Sudden Gains in Cognitive Therapy and Interpersonal Therapy for Social Anxiety Disorder

Science.gov (United States)

Bohn, Christiane; Aderka, Idan M.; Schreiber, Franziska; Stangier, Ulrich; Hofmann, Stefan G.

2013-01-01

Objective: The present study examined the effects of sudden gains on treatment outcome in a randomized controlled trial including individual cognitive therapy (CT) and interpersonal therapy (IPT) for social anxiety disorder (SAD). Method: Participants were 67 individuals with SAD who received 16 treatment sessions. Symptom severity at each session…

Personality type influence the gestational weight gain.

Science.gov (United States)

Franik, Grzegorz; Lipka, Nela; Kopyto, Katarzyna; Kopocińska, Joanna; Owczarek, Aleksander; Sikora, Jerzy; Madej, Paweł; Chudek, Jerzy; Olszanecka-Glinianowicz, Magdalena

2017-08-01

Pregnancy is frequently followed by the development of obesity. Aside from psychological factors, hormonal changes influence weight gain in pregnant women. We attempted to assess the potential association between personality type and the extent of gestational weight gain. The study group involved 773 women after term delivery (age 26.3 ± 3.9 years, body mass before pregnancy 61.2 ± 11.1 kg). Weight gain during pregnancy was calculated by using self-reported body mass prior to and during the 38th week of pregnancy. Personality type was assessed using the Polish version of the Framingham Type A Behavior Patterns Questionnaire (adapted by Juczynski). Two hundred forty-six (31.8%) study subjects represented type A personalities, 272 (35.2%) type B and 255 (33.0%) an indirect type. Gestational weight gain was related to the behavior patterns questionnaire score and age. In women gain was higher than in women with type B behavior of the same age. In women >30, the gestational weight gain was larger for type B personalities. Type A personality and increased urgency in younger pregnant women increases the risk of developing obesity during pregnancy in women below 30 years old. A higher level of competitiveness demonstrates a risk factor of excessive weight gain during pregnancy regardless of age.

IQ Gains in Argentina between 1964 and 1998

Science.gov (United States)

Flynn, James R.; Rossi-Case, Lilia

2012-01-01

The literature on IQ gains in Latin America is sparse. We estimate gains on Raven's Progressive Matrices in the city of La Plata (Argentina) between 1964 and 1998. The gains are robust at the top of the curve as well as at the bottom. Therefore, they are contrary to the hypothesis that nutrition played a major role in recent Argentine IQ gains.…

Loss restlessness and gain calmness: durable effects of losses and gains on choice switching.

Science.gov (United States)

Yechiam, Eldad; Zahavi, Gal; Arditi, Eli

2015-08-01

While the traditional conceptualization of the effect of losses focuses on bias in the subjective weight of losses compared with respective gains, some accounts suggest more global task-related effects of losses. Based on a recent attentional theory, we predicted a positive after-effect of losses on choice switching in later tasks. In two experimental studies, we found increased choice switching rates in tasks with losses compared to tasks with no losses. Additionally, this heightened shifting behavior was maintained in subsequent tasks that do not include losses, a phenomenon we refer to as "loss restlessness." Conversely, gains were found to have an opposite "calming" effect on choice switching. Surprisingly, the loss restlessness phenomenon was observed following an all-losses payoff regime but not after a task with symmetric mixed gains and losses. This suggests that the unresolved mental account following an all-losses regime increases search behavior. Potential implications to macro level phenomena, such as the leverage effect, are discussed.

The Impact of Capital Gains Taxes on Stock Price Reactions to S&P 500 Inclusion

OpenAIRE

Jennifer L. Blouin; Jana Smith Raedy; Douglas A. Shackelford

2000-01-01

This paper contributes to our understanding of the determinants of price responses to inclusion in the S&P 500 by providing evidence consistent with capital gains tax planning impacting stock reactions. Tests are conducted on 426 additions from 1978-1999. We regress the returns on the first trading day following announcement on a capital gains tax measure and controls. The evidence is consistent with the share prices of appreciated firms being temporarily bid up to compensate individual share...

Association of adult weight gain and nonalcoholic fatty liver in a cross-sectional study in Wan Song Community, China

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W.-J. Zhang

2014-02-01

Full Text Available Our objective was to examine associations of adult weight gain and nonalcoholic fatty liver disease (NAFLD. Cross-sectional interview data from 844 residents in Wan Song Community from October 2009 to April 2010 were analyzed in multivariate logistic regression models to examine odds ratios (OR and 95% confidence intervals (CI between NAFLD and weight change from age 20. Questionnaires, physical examinations, laboratory examinations, and ultrasonographic examination of the liver were carried out. Maximum rate of weight gain, body mass index, waist circumference, waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, fasting blood glucose, cholesterol, triglycerides, uric acid, and alanine transaminase were higher in the NAFLD group than in the control group. HDL-C in the NAFLD group was lower than in the control group. As weight gain increased (measured as the difference between current weight and weight at age 20 years, the OR of NAFLD increased in multivariate models. NAFLD OR rose with increasing weight gain as follows: OR (95%CI for NAFLD associated with weight gain of 20+ kg compared to stable weight (change <5 kg was 4.23 (2.49-7.09. Significantly increased NAFLD OR were observed even for weight gains of 5-9.9 kg. For the “age 20 to highest lifetime weight” metric, the OR of NAFLD also increased as weight gain increased. For the “age 20 to highest lifetime weight” metric and the “age 20 to current weight” metric, insulin resistance index (HOMA-IR increased as weight gain increased (P<0.001. In a stepwise multivariate regression analysis, significant association was observed between adult weight gain and NAFLD (OR=1.027, 95%CI=1.002-1.055, P=0.025. We conclude that adult weight gain is strongly associated with NAFLD.

Body weight gain after radioiodine therapy of hyperthyroidism; Koerpergewichtsentwicklung nach Radioiodtherapie einer Hyperthyreose

Energy Technology Data Exchange (ETDEWEB)

Scheidhauer, K.; Odatzidu, L.; Schicha, H. [Koeln Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Kiencke, P. [Koeln Univ. (DE). Inst. fuer Medizinische Statistik, Informatik und Epidemiologie (IMSIE)

2002-02-01

Aim: Analysis and follow up of body weight after radioiodine therapy (RITh) of hyperthyroidism, since excessive weight gain is a common complaint among these patients. Methods: Therapy and body weight related data of 100 consecutive RITh-patients were retrospectively analysed from the time before up to three years after RITh. All patients suffered from hyperthyroidism (Graves' disease or autonomy), but were adjusted to euthyroid levels after RITh. Patients' data were compared to a control group of 48 euthyroid patients out of the same ambulance and during the same time scale. Results: All patients (RITh and controls) gained weight over the time. There was no statistically significant difference in BMI development over three years between RITh-patients and controls (5.5% resp. 4.9% increase). In the first year after RITh, weight gain of the RITh patients was higher indeed, but lower in the follow up, resulting in the same range of weight gain after three years as the controls. Besides that women showed a slightly higher increase of BMI than men, and so did younger patients compared to elder as well as patients with overweight already before RITh. Conclusions: An initially distinct increase of body weight after RITh of hyperthyroidism is mainly a compensation of pretherapeutic weight loss due to hyperthyroidism. Presupposing adequate euthyroid adjustment of thyroid metabolism after therapy, RITh is not responsible for later weight gain and adipositas. (orig.) [German] Ziel: Untersuchung der Entwicklung des Koerpergewichtes nach {sup 131}I-Therapie einer Hyperthyreose, da der Radioiodtherapie (RITh) haeufig eine exzessive posttherapeutische Gewichtszunahme angelastet wird. Methoden: Retrospektiv wurden therapie- und koerpergewichtsbezogene Daten von 100 konsekutiven Patienten vor und bis drei Jahre nach RITh einer Hyperthyreose (Morbus Basedow oder funktionelle Autonomie) erfasst und mit denen einer euthyreoten Kontrollgruppe (n = 48) verglichen. Die

A Pilot Randomized Controlled Trial of a Technology-Based Approach for Preventing Excess Weight Gain during Pregnancy among Women with Overweight

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Ariana M. Chao

2017-11-01

Full Text Available ObjectiveOverweight/obesity and excess weight gain during pregnancy are associated with adverse maternal and neonatal outcomes. Few interventions have been effective in limiting gestational weight gain among women with overweight or obesity. This pilot, randomized clinical trial compared treatment as usual (TAU to a lifestyle modification program delivered via phone for the prevention of excess gestational weight gain in women who had overweight or obesity.MethodsParticipants included 41 pregnant women with a body mass index (BMI ≥ 25 kg/m2 (mean age = 28.7 ± 5.8 years; mean pre-gravid BMI = 31.2 ± 6.2 kg/m2; 54% black, 39% white. The intervention group (n = 20 received weekly telephone counseling sessions and used WiFi scales to monitor their weight from weeks 16 to 36 of pregnancy. We compared differences in weight and birth outcomes for the intervention vs. the TAU group (n = 21.ResultsThe intervention and TAU groups did not differ with respect to: gestational weight gain (15.5 ± 5.3 vs. 13.3 ± 6.8 kg, respectively; proportion gaining above the 2009 Institute of Medicine recommended weight range (83 vs. 70%; and weight gain from pre-pregnancy weight to 6 weeks postpartum (4.8 ± 4.6 vs. 3.0 ± 5.5 kg. Other birth and health outcomes also did not differ.ConclusionA telemedicine intervention designed to decrease logistical burden on participants was not more successful in reducing excessive weight gain during pregnancy as compared to TAU. Future studies should examine more intensive forms of remote treatment beginning earlier in pregnancy as well as interventions promoting a healthy weight prior to pregnancy.

Measured stimulated Raman gain in methane

International Nuclear Information System (INIS)

Lopert, R.B.

1983-01-01

This report is about the stimulated Raman effect in methane due to the nu 1 vibration. For various gas pressures between 150 torr and 30 atm, the Raman lineshape function was both experimentally measured and synthesized using a computer model. The stimulated Raman gain was measured by sending a pump laser beam provided by an argon-ion laser and a weak probe beam provided by a tunable dye laser through a cell of methane gas. The stimulated Raman effect caused some of the energy from the pump beam to be transferred to the probe beam. The intensity of the pump beam was low so the gain of the probe beam was on the order of parts per million. A two detector arrangement and a differential amplifier system that had a feedback loop to balance the detectors was constructed to measure the small gains. A detailed description of this detection system that was able to measure gains as small as 0.2 parts per million is provided

Gazpromi hiidprojekt käivitub / Sirje Rank

Index Scriptorium Estoniae

Rank, Sirje, 1966-

2007-01-01

Venemaa gaasikontsern Gazprom kaasas Shtokmani maardla hõlvamisse Prantsuse kütusefirma ning seega on kindlustatud ka Läänemere gaasijuhtme ehitus. Lisa: Gazpromi Shtokmani gaasimaardla kuulub maailma suuremate sekka; Number. Vt. samas: Paindlik gaasifirma; Tootmine vindub

Time-varying auditory gain control in response to double-pulse stimuli in harbour porpoises is not mediated by a stapedial reflex

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Asger Emil Munch Schrøder

2017-04-01

Full Text Available Echolocating animals reduce their output level and hearing sensitivity with decreasing echo delays, presumably to stabilize the perceived echo intensity during target approaches. In bats, this variation in hearing sensitivity is formed by a call-induced stapedial reflex that tapers off over time after the call. Here, we test the hypothesis that a similar mechanism exists in toothed whales by subjecting a trained harbour porpoise to a series of double sound pulses varying in delay and frequency, while measuring the magnitudes of the evoked auditory brainstem responses (ABRs. We find that the recovery of the ABR to the second pulse is frequency dependent, and that a stapedial reflex therefore cannot account for the reduced hearing sensitivity at short pulse delays. We propose that toothed whale auditory time-varying gain control during echolocation is not enabled by the middle ear as in bats, but rather by frequency-dependent mechanisms such as forward masking and perhaps higher-order control of efferent feedback to the outer hair cells.

Radiation hardness of thin Low Gain Avalanche Detectors

Science.gov (United States)

Kramberger, G.; Carulla, M.; Cavallaro, E.; Cindro, V.; Flores, D.; Galloway, Z.; Grinstein, S.; Hidalgo, S.; Fadeyev, V.; Lange, J.; Mandić, I.; Medin, G.; Merlos, A.; McKinney-Martinez, F.; Mikuž, M.; Quirion, D.; Pellegrini, G.; Petek, M.; Sadrozinski, H. F.-W.; Seiden, A.; Zavrtanik, M.

2018-05-01

Low Gain Avalanche Detectors (LGAD) are based on a n++-p+-p-p++ structure where an appropriate doping of the multiplication layer (p+) leads to high enough electric fields for impact ionization. Gain factors of few tens in charge significantly improve the resolution of timing measurements, particularly for thin detectors, where the timing performance was shown to be limited by Landau fluctuations. The main obstacle for their operation is the decrease of gain with irradiation, attributed to effective acceptor removal in the gain layer. Sets of thin sensors were produced by two different producers on different substrates, with different gain layer doping profiles and thicknesses (45, 50 and 80 μm). Their performance in terms of gain/collected charge and leakage current was compared before and after irradiation with neutrons and pions up to the equivalent fluences of 5 ṡ 1015 cm-2. Transient Current Technique and charge collection measurements with LHC speed electronics were employed to characterize the detectors. The thin LGAD sensors were shown to perform much better than sensors of standard thickness (∼300 μm) and offer larger charge collection with respect to detectors without gain layer for fluences gain prolongs the beneficial performance of LGADs. Pions were found to be more damaging than neutrons at the same equivalent fluence, while no significant difference was found between different producers. At very high fluences and bias voltages the gain appears due to deep acceptors in the bulk, hence also in thin standard detectors.

Ricardian Productivity Differences and the Gains from Trade

OpenAIRE

Andrei A. Levchenko; Jing Zhang

2013-01-01

This paper evaluates the role of sectoral heterogeneity in determining the gains from trade. We first show analytically that in the presence of sectoral Ricardian comparative advantage, a one- sector sufficient statistic formula that uses total trade volumes as a share of total absorption systematically understates the true gains from trade. Greater relative sectoral productivity differences lead to larger disparities between the gains implied by the one-sector formula and the true gains. Usi...

Active Microwave Metamaterials Incorporating Ideal Gain Devices

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Hao Xin

2010-12-01

Full Text Available Incorporation of active devices/media such as transistors for microwave and gain media for optics may be very attractive for enabling desired low loss and broadband metamaterials. Such metamaterials can even have gain which may very well lead to new and exciting physical phenomena. We investigate microwave composite right/left-handed transmission lines (CRLH-TL incorporating ideal gain devices such as constant negative resistance. With realistic lumped element values, we have shown that the negative phase constant of this kind of transmission lines is maintained (i.e., left-handedness kept while gain can be obtained (negative attenuation constant of transmission line simultaneously. Possible implementation and challenging issues of the proposed active CRLH-TL are also discussed.

Associations of neonatal high birth weight with maternal pre-pregnancy body mass index and gestational weight gain: a case-control study in women from Chongqing, China.

Science.gov (United States)

Xie, Yao Jie; Peng, Rong; Han, Lingli; Zhou, Xiaoli; Xiong, Zhengai; Zhang, Yuan; Li, Junnan; Yao, Ruoxue; Li, Tingyu; Zhao, Yong

2016-08-16

To examine the associations of maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) with neonatal high birth weight (HBW) in a sample of Chinese women living in southwest China. A hospital-based case-control study was conducted in Chongqing, China. A total of 221 mothers who delivered HBW babies (>4.0 kg) were recruited as cases and 221 age-matched (2-year interval) mothers with normal birth weight babies (2.5-4.0 kg) were identified as controls. ORs were estimated using conditional logistic regression analysis. For the analysis, pre-pregnancy BMI was categorised as underweight/normal weight/overweight and obesity and GWG was categorised as inadequate/appropriate/excessive. Among the cases, mean pre-pregnancy BMI was 21.8±2.8 kg/m(2), mean GWG was 19.7±5.1 kg and mean neonatal birth weight was 4.2±0.2 kg. In the controls, the corresponding values were 21.1±3.1 kg/m(2), 16.4±5.0 kg and 3.3±0.4 kg, respectively. More cases than controls gained excessive weight during pregnancy (80.1% vs 48.4%, p0.05). GWG was positively related to HBW after adjustment for gravidity, gestational age, newborns' gender and family income (OR=1.18, 95% CI 1.12 to 1.25; pweight women (OR=10.27, 95% CI 3.20 to 32.95; p<0.001). Overall, the findings suggest a significantly positive association between GWG and HBW. However, pre-pregnancy BMI shows no independent relationship with HBW. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

A randomized, double-blind, placebo-controlled proof of concept study to evaluate samidorphan in the prevention of olanzapine-induced weight gain in healthy volunteers.

Science.gov (United States)

Silverman, Bernard L; Martin, William; Memisoglu, Asli; DiPetrillo, Lauren; Correll, Christoph U; Kane, John M

2017-11-17

Antipsychotic medications are associated with weight gain and adverse metabolic effects that complicate the treatment and management of schizophrenia. Olanzapine (OLZ) in particular is associated with significant weight gain and adverse metabolic effects. The present Phase 1, proof of concept, multicenter, randomized, double-blind, placebo-controlled study investigated the safety and effect on weight of a combination of OLZ (10mg) and the opioid modulator samidorphan (SAM; 5mg) in comparison to OLZ alone in healthy, male normal weight volunteers. Altogether, 106 male subjects with stable body weight and BMI 18-25kg/m 2 were randomized to OLZ alone, OLZ+SAM, SAM alone, or placebo in a 2:2:1:1 ratio. The primary efficacy endpoint, mean (SD) body weight change from baseline to last assessment in the 3-week treatment period, was significantly less for OLZ+SAM vs. OLZ alone subjects [+2.2 (1.4) kg vs. +3.1 (1.9) kg; respectively; p=0.02]. In contrast, there was no significant difference in weight from baseline for either SAM or placebo [+0.1 (1.0) kg and +0.8 (1.4) kg, respectively]; p=0.09. Overall, OLZ+SAM compared to OLZ alone had similar safety and tolerability. In addition, less nausea was observed in subjects given OLZ+SAM compared to SAM alone. Thus, OLZ+SAM may offer effective treatment of schizophrenia with less weight gain and metabolic risk. Additional research exploring additional doses over longer durations in psychiatric populations is warranted. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

A Preliminary Model for Spacecraft Propulsion Performance Analysis Based on Nuclear Gain and Subsystem Mass-Power Balances

Science.gov (United States)

Chakrabarti, Suman; Schmidt, George R.; Thio, Y. C.; Hurst, Chantelle M.

1999-01-01

A preliminary model for spacecraft propulsion performance analysis based on nuclear gain and subsystem mass-power balances are presented in viewgraph form. For very fast missions with straight-line trajectories, it has been shown that mission trip time is proportional to the cube root of alpha. Analysis of spacecraft power systems via a power balance and examination of gain vs. mass-power ratio has shown: 1) A minimum gain is needed to have enough power for thruster and driver operation; and 2) Increases in gain result in decreases in overall mass-power ratio, which in turn leads to greater achievable accelerations. However, subsystem mass-power ratios and efficiencies are crucial: less efficient values for these can partially offset the effect of nuclear gain. Therefore, it is of interest to monitor the progress of gain-limited subsystem technologies and it is also possible that power-limited systems with sufficiently low alpha may be competitive for such ambitious missions. Topics include Space flight requirements; Spacecraft energy gain; Control theory for performance; Mission assumptions; Round trips: Time and distance; Trip times; Vehicle acceleration; and Minimizing trip times.

Cycle training induces muscle hypertrophy and strength gain: strategies and mechanisms.