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3523 Uppsatser om Frequency inverter control - Sida 14 av 235
Design och implementering av styrlagar för generisk flygplansmodell
For research purposes Saab has developed a generic mathematical model denoted VEGAS of an aircraft with a configuration similar to JAS 39 Gripen. Today parts of Gripen backup control system are used also for VEGAS making the system subject to both corporate and defense secrecy. The main objective of this master thesis is to design, verify and implement public pitch axis flight control system for VEGAS. Furthermore, simplifications regarding the design process is to be examined. Design of pitch axis flight control system for the entire flight envelope has been carried out.
Vindfällning i naturliga och skapade bryn och kanter :
The aim of this work was to study if the edge of the forest is more resistant to heavy winds than the trees located further in from the edge, and how this edge effect changes between different types of tree species and site types.
The data was collected from an electric power line going from the north to the south of
Sweden. The mean value of the clearcutted area around the power line was 120 meters. The
main direction of the storm in January 2005 was west-southwest and thus the power line was a perfect place for gathering a large data set.
The main parameter studied was the damage frequency at the edge of the forest compared to
the trees located further in from the edge (up to 100 m from the power line). Tree species mixture, soil moisture class, soil type, topography, stand height, stand height of the stand on the other side of the power line and wind exposition was estimated.
The results showed a distinct edge effect. The edge of the forest had clearly lower damage frequency for all tree species.
A marked difference was observed between tree species and damage frequency.
Alternativa dagvattenlösningar för nyexploateringsområden med avseende på substansflöden
Denna rapport beskriver arbetet med utvecklingen av en ny modell för kaplanturbiner. Utvecklingen bygger på två kopplade differentialekvationer som under arbetets gång anpassats och implementerats i turbinmodellen.Modellen beskriver hur vattenflöde och turbinmoment påverkas av avvikelsen från den optimala kombineringskurvan för vinklarna på turbinens ledskena och löphjul, och är anpassad för ett referensaggregat med tillgängliga provdata. Även övriga enheter i vattenkraftaggregatet modelleras och sätts samman med frekvensregulator och elnät för att simulera aggregatets reglerstabilitet i önätsdrift.Verifieringen av turbinmodellen sker genom försök att återskapa de befintliga verkningsgradskurvorna med hjälp av modellen. Resultatet visar en god följning av de verkliga kurvformerna, dock med något lägre maximal verkningsgrad.Verifieringen av önätmodellen sker genom att prova stabiliteten i nätfrekvens och turbineffekt vid stegpålastningar. Resultatet ger en stabilare reglerstabilitet än i verkligheten, men uppfyller ändå förväntningarna på en fungerande modell.This report describes the development of a new kaplan turbine model.
Private equity företagens styrning av sina portföljbolag.: Två fallstudier av relationen mellan private equity företag och portföljbolag.
The purpose of this thesis is to examine and analyze the characteristics of the management control system private equity firms use to manage their portfolio companies. The thesis takes a share holder value perspective, and it is assumed that the goal of the management control system is to increase the shareholder value in the portfolio company. In a qualitative study two private equity firms and two portfolio companies, one for each private equity firm, were studied in detail. In total, nine in debt interviews were completed. The results from this study suggest that the characteristics of the control system are dependent on the surrounding context; the focus on shareholder value and the specific characteristics of the private equity industry shape the characteristics of the management control system.
Åt var och en efter behov? Kriminalitet som markör för olika behandlingsalternativ
The aim of this study was to, using previously collected data from self-declared antisocial behaviour questionnaires, examine if the crime frequency has been different between adolescents that have either been referred to two different forms of open care in social service, child and youth psychiatric inpatient care or have been sent to Homes for Specialised Supervision. The criminality frequency and the most common crimes committed were compared between the study groups and further between genders in each particular study group. Statistical significance testing was used and the results of the survey revealed that juvenile delinquents that had committed severe criminal acts were represented in all four groups. The study group with adolescents in national care was the most different from other groups. These youths seemed to have had a lower crime frequency than the other groups with the exception assault and robbery.
Trådlös energiöverföring via elektromagnetisk induktion
This paper describes a method for wireless energy transfer via near-field electromagnetic inductionthat is inexpensive, simple and can be applied to almost any type of system, regardless of size andenergy demands.The method uses a primary unit consisting of an oscillator, amplifier and inductive coil thattransfers energy to a secondary unit consisting of a coil, rectifier and voltage regulator. Two typesof oscillators and several amplifier designs were realized and evaluated together with a multitudeof flat coils of both monofilar and bifilar type.The results show that it is important to use an oscillator whose frequency is dependent on theinductance of the connected transmission coil, such as the Colpitts oscillator. This is preferable toan oscillator with a preset frequency, such as a Schmitt-trigger oscillator..
Oxytocin-Ett risktagande eller en tillförlitlig behandling vid långdraget förlossningsförlopp hos förstföderskor
Background: Breastfeeding frequency decrease in Sweden and infants born preterm is a particularly vulnerable group to not be breastfed according to current recommendations. Mothers of preterm infants have an extra need of support from the health care system. Mothers' self-efficacy in breastfeeding affects the outcome of breastfeeding. Health professionals' attitudes to breastfeeding have an impact on the breast feeding support they provide to the mothers.Aim: To investigate whether an intervention could strengthen self-efficacy in breastfeeding among mothers of premature babies. A further aim was to investigate whether the intervention influenced health professionals' attitudes to breastfeeding.Method/Design: An experimental study with quantitative approach in the form of questionnaire survey was conducted.
Styrning Mot Högre Motivation: En fallstudie av ICA Kvantum Flygfyren
The aim of this paper is to examine how the design of management control in a retail trade company affects motivation among its employees. Our purpose is to identify what actions create motivation and how management can benefit by developing and promoting such activity from its high-performing employees. Motivated personnel have become increasingly important in companies today, and companies are increasingly reliant on individual employees? capabilities. The study covers all parts of the management control system, to see how these align to create goal congruence in an organizational context.
Svansbitning hos grisar, arv eller miljö?
Tail-biting in pigs is an animal welfare issue and in Sweden during 2002 the producers lost tree million Swedish crowns because of tail biting. This economic loss depends on the pigs which are discarded at slaughter because of tail biting. Tail biting can be separated into two stages, "pre-injury" and "injury". The aim of this study is to investigate if tail biting depends on environment or genetic background.A lot of research on the environments effects on the behaviour of pigs but not so much on the genetic effects has been performed. The frequency of tail biting in pig farms influence among others of environment enrichment, ventilation, gender and breed of the pig.
Underlag för bedömning av energibrunnar inom vattenskyddsområde
Denna rapport beskriver arbetet med utvecklingen av en ny modell för kaplanturbiner. Utvecklingen bygger på två kopplade differentialekvationer som under arbetets gång anpassats och implementerats i turbinmodellen.Modellen beskriver hur vattenflöde och turbinmoment påverkas av avvikelsen från den optimala kombineringskurvan för vinklarna på turbinens ledskena och löphjul, och är anpassad för ett referensaggregat med tillgängliga provdata. Även övriga enheter i vattenkraftaggregatet modelleras och sätts samman med frekvensregulator och elnät för att simulera aggregatets reglerstabilitet i önätsdrift.Verifieringen av turbinmodellen sker genom försök att återskapa de befintliga verkningsgradskurvorna med hjälp av modellen. Resultatet visar en god följning av de verkliga kurvformerna, dock med något lägre maximal verkningsgrad.Verifieringen av önätmodellen sker genom att prova stabiliteten i nätfrekvens och turbineffekt vid stegpålastningar. Resultatet ger en stabilare reglerstabilitet än i verkligheten, men uppfyller ändå förväntningarna på en fungerande modell.This report describes the development of a new kaplan turbine model.
Beteenden hos geparder i två stora svenska djurparker
Cheetahs in the wild are declining due to hunting, lack of prey, exploitation of habitats and loss of cubs to predators. Those are the main reasons to why cheetahs are kept in captivity today for conservation. Many cheetahs kept in captivity are seen pacing ? a behaviour that arise when the animal is prohibited from performing natural behaviours. It is believed to being attributed to a lack of stimulation in the environment where they are being held.
Karriärcoaching och dess påverkan på den prestationsbaserade självkänslan.
Karriärcoaching är en tjänst som ökat kraftigt på den svenska marknaden. Tidigare studier inom området har visat att en stark självkänsla stärker en persons hälsa och underlättar för denne att hantera problem. Syftet med studien var att undersöka om karriärcoaching har någon påverkan på prestationsbaserad självkänsla, känslan av kontroll (Locus of Control) samt självbemästring av tankar och känslor (Self-Efficacy). Genom en enkätundersökning har en grupp som genomfört karriärcoaching jämförts med en kontrollgrupp som ej genomfört karriärcoaching. Ett oberoende t-test gav en signifikant skillnad i Locus of Control (p<.05).
Förändring av styrning inom en offentlig stödverksamhet: En studie över hur styrningen förändras inom en offentlig serviceenhet påverkas av en privatisering
The purpose of this study is to perform an in-depth analysis of what effects a privatization of a service organization has on the management control system within the organization. The paper studies a service organization which provides service for the county council in Östergötland, Sweden. The result is based on interviews with several people, both within the acquiring private company and also within the county council in Östergötland, and analyzed using Samuelson?s (2005) framework from his study ?Organizational, Governance and Control ?. The major finding in the thesis is that the factors that have had the largest impact on the changes in management control are the new owner demands and the degree of operationalization of the overall goal..
Barn och smartphones - En studie av föräldrars attityder kring integritetsaspekten när det gäller barn och smartphones
The purpose of this essay was to sort out parents attitudes concerning children and their use of smartphones, primarily in regards to the integrity-aspect. I have studied if parents believe that their children should have smartphones, if they want to control their use, how they want to control their use and what implications this might have. I've chosen two methods for my research, one quantitative, online questionnaires, and one qualitative, semi-structured interviews. My base has been previous research in the area, to the extent it existed. My findings suggest that parents, on the whole, are positive to letting their children use smartphones but that they?d like some sort of control over their use.
Internal Control - Efficiency in the Audit Process
The purpose of this research is to examine the implications of the provisions in the Swedish Code of Corporate Governance (the Code) concerning auditor attestation of the internal control report. We will focus on how the auditors? augmented responsibilities will affect the efficiency in the audit process.Our research indicates that the main benefit from reviewing the internal control report is achieving more reliable internal controls, which results in greater prevention of misstatements in the financial statements. This will affect the efficiency in the audit process since the auditor can place more reliance on internal controls when performing audit procedures. This implies that the benefits of preventing misstatements could outweigh the efforts and resources spent on reviewing the internal control report..