907 resultados para scalar control and adjustment


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Tässä sähkövoimatekniikan insinöörityössä on käsitelty taajuusmuuttajan vaihtamisprosessia. Työ on tehty Oy Sinebrychoff Ab:n Keravan tuotantolaitokselle täyttöosastolle 0.33 litran lasipullon pakkaajarobottiin. Työssä on aluksi todettu olevan kahdenlaisia taajuusmuuttajia: suoria ja välipiirillisiä. Tämän jälkeen on käsitelty taajuusmuuttajan rakennetta yleisesti tutustumalla taajuusmuuttajan neljään pääosaan: tasasuuntaajaan, välipiiriin, vaihtosuuntaajaan sekä ohjauspiirin. Lisäksi on tutustuttu erilaisiin taajuusmuuttajan ohjaus- ja säätötapoihin kuten skalaariohjaus ja -säätö, vektorisäätö sekä suoravääntömomenttisäätö. Työssä on lisäksi käsitelty taajuusmuuttajien käyttökohteita, tulevaisuutta sekä niiden hyötyjä teollisuudelle. Työssä on käsitelty myös Vaconin taajuusmuuttaja tuotesarjoja NXS, NXP sekä NXL ja vertailtu niiden eroja ja käyttökohteita. Lisäksi on käsitelty Vaconin ”All in One” -ohjelmasovelluspakettia, joka sisältää seitsemän erilaista ohjelmasovellusta: perussovellus, vakiosovellus, paikallis/kauko-ohjaussovellus, vakionopeussovellus, PID-säätösovellus, erikoiskäyttösovellus, pumppu- ja puhallinautomatiikkasovellus. Lisäksi on tutustuttu valitun taajuusmuuttajan lajimerkkiavaimeen eli käsitelty kirjainten ja numeroiden merkitystä taajuusmuuttajamallille. Taajuusmuuttajan vaihtamisosiossa käsitellään vaihtamisprosessia aloittaen vanhan SEW Eurodrive - taajuusmuuttajan irrottamisesta sekä ohjausarvojen mittaamisesta. Tämän jälkeen käsitellään uuden VACON NXS -taajuusmuuttajan asentamista sekä valitun sovel-lusohjelman parametrien asettamista moottorille sopivaksi. Lisäksi työssä on tutustuttu vaihdettavan taajuusmuuttajan käyttöympäristöön ja piirretty uudestaan taajuusmuuttaja-käytön piirikuvat CADS-ohjelmalla, jotta piirikaavioissa liittimien numeroinnit vastaisivat uuden taajuusmuuttajan liittimien numeroita. Työn lopussa on käsitelty työn etuja yritykselle ja linjan toimivuudelle. Lisäksi on laskettu työn kannattavuutta yritykselle sekä laskettu aika, jolloin taajuusmuuttaja maksaa itsensä takaisin.

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The present study was designed to examine the main and interactive effects of task demands, work control, and task information on levels of adjustment. Task demands, work control, and task information were manipulated in an experimental setting where participants completed a letter-sorting activity (N = 128). Indicators of adjustment included measures of positive mood, participants' perceptions of task performance, and task satisfaction. Results of the present study provided some support for the main effects of objective task demands, work control, and task information on levels of adjustment. At the subjective level of analysis, there was some evidence to suggest that work control and task information interacted in their effects on levels of adjustment. There was minimal support for the proposal that work control and task information would buffer the negative effects of task demands on adjustment. There was, however, some evidence to suggest that the stress-buffering role of subjective work control was more marked at high, rather than low, levels of subjective task information.

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The present study examined the effects of work control and job demands on employee adjustment and work performance using a multidimensional measure of work control (assessing levels of task control, decision control and work scheduling control). It was proposed that the negative effects of job demands and employee adjustment would be moderated by high levels of task control. It was also proposed that there would be evidence of main effects of both job demands and work control (particularly task-related levels of control) on employee adjustment. To test these predictions, a study of 135 university employees holding administrative positions was undertaken. Methodological improvements over previous research included the use of both self-reported adjustment measures and supervisor ratings of work performance as outcome variables, and the assessment of the predictor and outcome measures at different points in time (self-reported adjustment was assessed at both Times 1 and 2). The results revealed some support for the proposal that the effects of job demands would be buffered by high levels of task control, but not more peripheral aspects of work control. There were also significant main effects of task control on job satisfaction.

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Thesis (Ph.D.)--University of Washington, 2016-08

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Heart transplantation remains the best therapeutic option for the treatment of end-stage heart failure. However, good survival rates can be obtained only if patients are closely monitored, particularly for their immunosuppressive regimens. Currently, a triple-drug regimen usually based on calcineurin-inhibitors (cyclosporin A or tacrolimus), anti-proliferative agents and steroids is used in most recipients. New agents such as the mTOR inhibitors, a more recently developed class of immunosuppressive drugs, can also be used in some patients. The aim of this article is to review currently used immunosuppressive regimens after heart transplantation, and to propose some individualized options depending on specific patient characteristics and recent pharmacological developments in the field.

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This thesis was made in Naantali plant of Finnfeeds Finland Oy. In this thesis the main study was in reducing, controlling, measuring and processing odour effluents in various methods. Also are considered legislation, marketing issues and environmental requirements of reducing of odour effluents. The literature review introduces odours complications, legislations and various methods of odour removal. There is also a review of volatile organic compounds detection and measuring methods. The experimental section consists TD-GC-MS-measurements and expansive measurements with electronic nose. Electronic nose is a new solution for recognition and measuring industrial odours. In this thesis the electronic nose was adapted into reliable recognition and measuring method. Measurements with electronic nose was made in betaine factory and main targets were odour removal process and other odours from factory. As a result of experimental work with TD-GC-MS-measurements becomes odour compound of 2-and 3- methylbutanal and dimethyldisulfide, which odour is sweet and fug. Extensive study with electronic nose found many developmental subjects. Odour balance measurements of factory and after calculation made adjustment of odour removal process, over all odour effluent to environment will reduce 25 %.

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En aquesta tesis s'ha desenvolupat un sistema de control capaç d'optimitzar el funcionament dels Reactors Discontinus Seqüencials dins el camp de l'eliminació de matèria orgànica i nitrogen de les aigües residuals. El sistema de control permet ajustar en línia la durada de les etapes de reacció a partir de mesures directes o indirectes de sondes. En una primera etapa de la tesis s'ha estudiat la calibració de models matemàtics que permeten realitzar fàcilment provatures de diferents estratègies de control. A partir de l'anàlisis de dades històriques s'han plantejat diferents opcions per controlar l'SBR i les més convenients s'han provat mitjançant simulació. Després d'assegurar l'èxit de l'estratègia de control mitjançant simulacions s'ha implementat en una planta semi-industrial. Finalment es planteja l'estructura d'uns sistema supervisor encarregat de controlar el funcionament de l'SBR no només a nivell de fases sinó també a nivell cicle.

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A theory is presented for the adjustment of the Antarctic Circumpolar Current (ACC) and global pycnocline to a sudden and sustained change in wind forcing. The adjustment timescale is controlled by the mesoscale eddy diffusivity across the ACC, the mean width of the ACC, the surface area of the ocean basins to the north, and deep water formation in the North Atlantic. In particular, northern sinking may have the potential to shorten the timescale and reduce its sensitivity to Southern Ocean eddies, but the relative importance of northern sinking and Southern Ocean eddies cannot be determined precisely, largely due to limitations in the parameterization of northern sinking. Although it is clear that the main processes that control the adjustment timescale are those which counteract the deepening of the global pycnocline, the theory also suggests that the timescale can be subtly modified by wind forcing over the ACC and global diapycnal mixing. Results from calculations with a reduced-gravity model compare well with the theory. The multidecadal-centennial adjustment timescale implies that long observational time series will be required to detect dynamic change in the ACC due to anthropogenic forcing. The potential role of Southern Ocean mesoscale eddy activity in determining both the equilibrium state of the ACC and the timescale over which it adjusts suggests that the response to anthropogenic forcing may be different in coupled ocean-atmosphere climate models that parameterize and resolve mesoscale eddies.

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The major contribution of this paper relates to the practical advantages of combining Ground Control Points (GCPs), Ground Control Lines (GCLs) and orbital data to estimate the exterior orientation parameters of images collected by CBERS-2B (China-Brazil Earth Resources Satellite) HRC (High-resolution Camera) and CCD (High-resolution CCD Camera) sensors. Although the CBERS-2B is no longer operational, its images are still being used in Brazil, and the next generations of the CBERS satellite will have sensors with similar technical features, which motivates the study presented in this paper. The mathematical models that relate the object and image spaces are based on collinearity (for points) and coplanarity (for lines) conditions. These models were created in an in-house developed software package called TMS (Triangulation with Multiple Sensors) with multi-feature control (GCPs and GCLs). Experiments on a block of four CBERS-2B HRC images and on one CBERS-2B CCD image were performed using both models. It was observed that the combination of GCPs and GCLs provided better bundle block adjustment results than conventional bundle adjustment using only GCPs. The results also demonstrate the advantages of using primarily orbital data when the number of control entities is reduced. © 2013 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).

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Existing studies of on-line process control are concerned with economic aspects, and the parameters of the processes are optimized with respect to the average cost per item produced. However, an equally important dimension is the adoption of an efficient maintenance policy. In most cases, only the frequency of the corrective adjustment is evaluated because it is assumed that the equipment becomes "as good as new" after corrective maintenance. For this condition to be met, a sophisticated and detailed corrective adjustment system needs to be employed. The aim of this paper is to propose an integrated economic model incorporating the following two dimensions: on-line process control and a corrective maintenance program. Both performances are objects of an average cost per item minimization. Adjustments are based on the location of the measurement of a quality characteristic of interest in a three decision zone. Numerical examples are illustrated in the proposal. (c) 2012 Elsevier B.V. All rights reserved.

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This study was the final stage of a four-year study of managerial behaviour and company performance in Bulgaria and examined the influence of changing ownership and control structures of companies on managerial behaviour and initiative. It provides a theoretical summary of the specific types of ownership, control, governance structures and managerial strategies in the Bulgarian transitional economy during 1992-1996. It combines two theoretical approaches, the property-rights approach to show concentrated property-rights structure and private and majority types of control as determinants of efficient enterprise risk bearing and constrained managerial discretion, and the agency theory approach to reveal the efficient role of direct non-market governance mechanisms over managers. Mr. Peev also used empirical information collected from the Central Statistical office in Bulgaria, three different enterprise investigations of corporatised state-owned enterprises between 1992 and 1994, and his own data base of privatised and private de novo industrial companies in 1996-1996. The project gives a detailed description of the main property-rights structures in Bulgaria at the present time and of the various control structures related to these. It found that there is a strong owner type of control in private and privatised firms, although, contrary to expectations, 100% state -owned enterprises tended to be characterised by a separation of ownership from control, leaving scope for managerial discretion. Mr. Peev predicts that after the forthcoming mass privatisation, many companies will acquire a dispersed ownership structure and there will be a greater separation of ownership from control and potential or inefficient managerial behaviour. The next aspect considered in detail was governance structures and the influence of the generally unstable macroeconomic environment in the country during the period in question. In examining managerial strategies, Mr. Peev divided the years since 1990 into 3 periods. Even in the first period (1990-1992) there were some signs of a more efficient role for managers and between 1992 and 1994 the picture of control structures and different managerial behaviour in state-owned companies became more diversified. Managerial strategies identified included managerial initiatives for privatisation, where managers took initiative in resolving problems of property rights and introducing restructuring measures and privatisation proposals, managerial initiatives for restructuring without privatisation, and passive adjustment and passive management, where managers seek outside services for marketing, finance management, etc. in order to adjust to the new environment. During 1995-1996 some similarities and differences between the managerial behaviour of privatised and state-owned firms emerged. Firstly, the former have undergone many changes in investment and technology, while managers of state-owned companies have changed little in this field, indicating that the private property-rights structure is more efficient for the long-term adaptation of enterprises. In the area of strategies relating to product quality, marketing, and pricing policy there was little difference between managers of private, privatised and state-owned firms. The most passive managerial behaviour was found in non-incorporated state-owned firms, although these have only an insignificant stake in the economy.

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Body height decreases throughout the day due to fluid loss from the intervertebral disk. This study investigated whether spinal shrinkage was greater during workdays compared with nonwork days, whether daily work stressors were positively related to spinal shrinkage, and whether job control was negatively related to spinal shrinkage. In a consecutive 2-week ambulatory field study, including 39 office employees and 512 days of observation, spinal shrinkage was measured by a stadiometer, and calculated as body height in the morning minus body height in the evening. Physical activity was monitored throughout the 14 days by accelerometry. Daily work stressors, daily job control, biomechanical workload, and recreational activities after work were measured with daily surveys. Multilevel regression analyses showed that spinal disks shrank more during workdays than during nonwork days. After adjustment for sex, age, body weight, smoking status, biomechanical work strain, and time spent on physical and low-effort activities during the day, lower levels of daily job control significantly predicted increased spinal shrinkage. Findings add to knowledge on how work redesign that increases job control may possibly contribute to preserving intervertebral disk function and preventing occupational back pain.

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A belief that doctors or family control one's health outcomes (external health locus of control), and a belief in one's own ability to achieve desired outcomes (general self-efficacy), may influence distress experienced in relation to a physical illness. This study examined the interaction between illness severity, external health locus of control and general self-efficacy in relation to distress. Illness severity was defined as acute or chronic illness, with the latter expected to be more stressful. Participants described a serious illness they experienced, and completed self-report scales in relation to it. Results confirmed that chronic illnesses were associated with more distress than acute illnesses across the sample. Hierarchical multiple regression analyses supported the predicted effects on distress of a three-way interaction involving external health locus of control, general self-efficacy and illness severity (acute vs. chronic). Analysis of these results may assist in explaining inconsistencies in previous research, and offer a model for understanding the role of person variables in emotional distress.

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Objective: The effect of work on blood pressure (BP) in a general population with appropriate adjustment for confounders is not well defined. High job control has been found to be associated with lower BP and with nocturnal BP dipping. However, with older workers this may be compromised and has not been studied extensively. Methods: A cross-sectional study was carried out on a primary care-based sample (N=2047) aged 50–69 years. Data were collected on sociodemographic factors, medication, clinic, and ambulatory blood pressure. Job control was measured using two scales from the Copenhagen Psychosocial Questionnaire (COPSOQ) (possibility for development and influence at work). Nocturnal systolic BP (SBP) dipping was the reduction in SBP from day- to night-time using ambulatory SBP readings. Results: In general, BP increased with age, male gender, and higher body mass index. Workers with high influence at work and high possibility for development were more likely to have high asleep SBP [odds ratio (OR) 2.13, 95% confidence interval (95% CI) 1.05–4.34, P=0.04], (OR 2.27, 95% CI 1.11–4.66, P=0.03) respectively. Influence at work and awake BP were inversely associated: awake SBP (OR 2.44, 95% CI 1.35–4.41, P<0.01), awake DBP (OR 2.42, 95% CI 1.24–4.72, P=0.01). No association was seen between job control and nocturnal SBP dipping. Conclusion: Older workers with high job control may be more at risk of cardiovascular disease resulting from high day- and night-time BP with no evidence of nocturnal dipping.

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Up to 20% of women with hypertensive pregnancy disorders might persist with chronic hypertension. This study compared clinical and echocardiographic features between women whose hypertension began as hypertensive pregnancy disorders (PH group) and women whose diagnosis of hypertension did not occur during pregnancy (NPH group). Fifty PH and 100 NPH women were cross-sectionally evaluated by clinical, laboratory, and echocardiography analysis, and the groups were matched by duration of hypertension. PH exhibited lower age (46.6 ± 1.4 vs. 65.3 ± 1.1 years; P < .001), but higher systolic (159.8 ± 3.9 vs. 148.0 ± 2.5 mm Hg; P = .009) and diastolic (97.1 ± 2.4 vs. 80.9 ± 1.3 mm Hg; P < .001) blood pressure than NPH, although used more antihypertensive classes (3.4 ± 0.2 vs. 2.6 ± 0.1; P < .001). Furthermore, PH showed higher left ventricular wall thickness and increased prevalence of concentric hypertrophy than NPH after adjusting for age and blood pressure. In conclusion, this study showed that PH may exhibit worse blood pressure control and adverse left ventricular remodeling compared with NPH.