951 resultados para corner kick
Resumo:
This year we present three papers on recent advances in paediatrics from the fields of neonatology, adolescent medicine and Duchenne muscular dystrophy. 1. Recent studies question the application of pure oxygen for neonatal reanimation and suggest that lower concentrations or even air may be more adequate for the reanimation of most newborns. 2. Bullying is an aggressive, repetitive and intentionally blessing behaviour. It is observed mainly at school and the victims are usually children with a weak personality or children suffering from chronic diseases. The doctor's role is to detect this behaviour and to help protect the victims. 3. The respiratory surveillance of patients with Duchenne muscular dystrophy is the corner-stone of their management. An algorithm allows to time correctly the initiation of non-invasive ventilation and to insure as long as possible a good life quality.
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Storm Lake, the state's fourth largest natural lake, has been the centerpiece of significant economic development, including a resort, water park, and state marina. While there have been considerable improvements to the lake's water quality through a major on-going lake restoration program and watershed project, the Little Storm Lake area still needs to be addressed. Little Storm Lake is a 190 acre area on the nmihwest side of Storm Lake. The water level in both areas is based on the dam height located on the southeast corner of Storm Lake. Approximately 70% of the water from the watershed flows through Little Storm Lake. Little Storm Lake originally had the ability to remove much of the sediment and nutrients from incoming waters. However, due to degradation, proper wetland function has been compromised. Under normal hydrologic conditions Little Storm Lake has the potential to function as a sediment trap for Storm Lake, but tllis capacity is overwhelmed during high flows. Little Storm Lake is at or near its sediment trapping capacity, which results in higher sediment transport into Storm Lake. Resuspension of sediments due to wind and other in-lake dynamics, such as rough fish, further exacerbate the total turbidity from suspended sediment and results in movement of sediment from Little Storm Lake into Storm Lake. This project includes a fish barrier and water retention structure between Little Storm Lake and Storm Lake and the construction of a pumping station and associated equipment. The project involves periodic dewatering of Little Storm Lake during years of favorable climatological conditions to consolidate the sediments and revegetate the area. Construction of the fish banier would aid restoration efforts by preventing rough fish from destroying the vegetation and would decrease recruitment of rough fish by limiting their spawning area. In the future, if the diminished trapping capacity of Little Storm Lake still results in sediment moving into Storm Lake, a dredging project would be initiated to deepen Little Storm Lake.
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Price Creek is a 13 mile long stream located in SE Benton County and the NE corner of Iowa County. It ends below the village of Amana where it flows into the Iowa River. The Iowa and Benton County Soil & Water Conservation Districts (SWCDs) applied (and were tentatively approved) for 319/WPF/WSPF funding to treat livestock and water quality issues in this watershed over the next three years. That projects funds were allocated for a Project Coordinator, information and education activities, and cost share for Best Management Practices (BMPs) directed toward livestock issues and nutrient issues. Soil erosion and sedimentation are also problems in this 18,838 acre watershed. It is 64% HEL (highly erodible land) and 58% of it is cropped. With a coordinator working with Price Creek producers, this would be an excellent time to also address the soil loss and sedimentation issues in this watershed. We will offer additional cost share incentives on BMPs targeting soil erosion on the critical areas weve identified. We are applying to IWIRB for additional funding to allow us to cost share specific BMPs up to 75% to treat soil loss in these critical areas of the Price Creek Watershed.
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Dry Run Creek Watershed was designated an impaired waterbody by DNR in 2002, following an assessment of the biota in the stream by DNR Biologist, Tom Wilton. Subsequent studies by IOWATER Snapshot effort in 2003, found e-coli bacteria concentrations and high nitrate readings in excess of the State of Iowa limits for recreational streams. The Dry Run Creek Watershed Improvement Project is comprised of five major components. Three components will feature demonstrations of structural best management practices (BMPs) to protect water quality in Dry Run Creek. The fourth is an educational workshop to "kick-off" the initiative and background the stakeholders of the watershed in new stormwater management strategies for water quality protection. The fifth is a monitoring program that will provide data on the effectiveness of the practices to be demonstrated. Measurable outcomes from these projects include monitoring to document the effectiveness of infiltration based BMPs to reduce pollutant loading in urban stormwater runoff and reducing the volume of stormwater discharged directly into Dry Run Creek via storm sewer flows. Understanding of and social acceptance of new stormwater strategies and practices will also be monitored by surveys of watershed stakeholders and compared to findings of a survey done before the start of the project.
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Portland cement concrete (PCC) pavement undergoes repeated environmental load-related deflection resulting from temperature and moisture variations across pavement depth. This has been recognized as resulting in PCC pavement curling and warping since the mid-1920s. Slab curvature can be further magnified under repeated traffic loads and may ultimately lead to fatigue failures, including top-down and bottom-up transverse, longitudinal, and corner cracking. It is therefore significant to measure the true degree of curling and warping in PCC pavements, not only for quality control (QC) and quality assurance (QA) purposes, but also for better understanding of its relationship to long-term pavement performance. Although several approaches and devicesincluding linear variable differential transducers (LVDTs), digital indicators, and some profilershave been proposed for measuring curling and warping, their application in the field is subject to cost, inconvenience, and complexity of operation. This research therefore explores developing an economical and simple device for measuring curling and warping in concrete pavements with accuracy comparable to or better than existing methodologies. Technical requirements were identified to establish assessment criteria for development, and field tests were conducted to modify the device to further enhancement. The finalized device is about 12 inches in height and 18 pounds in weight, and its manufacturing cost is just $320. Detailed development procedures and evaluation results for the new curling and warping measuring device are presented and discussed, with a focus on achieving reliable curling and warping measurements in a cost effective manner.
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In soccer, dead-ball moves are those in which the ball is returned to play from a stationary position following an interruption of play. The aim of this study was to analyse the effectiveness of one such dead-ball move, namely corner kicks, and to identify the key variables that determine the success of a shot or header following a corner, thereby enabling a model of successful corner kicks to be proposed. We recorded 554 corner kicks performed during the 2010 World Cup in South Africa and carried out a univariate, bivariate and multivariate analysis of the data. The results indicated that corners were of limited effectiveness in terms of the success of subsequent shots or headers. The analysis also revealed a series of variables that were significantly related to one another, and this enabled us to propose an explanatory model. Although this model had limited explanatory power, it nonetheless helps to understand the execution of corner kicks in practical terms.
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Combinatorial optimization involves finding an optimal solution in a finite set of options; many everyday life problems are of this kind. However, the number of options grows exponentially with the size of the problem, such that an exhaustive search for the best solution is practically infeasible beyond a certain problem size. When efficient algorithms are not available, a practical approach to obtain an approximate solution to the problem at hand, is to start with an educated guess and gradually refine it until we have a good-enough solution. Roughly speaking, this is how local search heuristics work. These stochastic algorithms navigate the problem search space by iteratively turning the current solution into new candidate solutions, guiding the search towards better solutions. The search performance, therefore, depends on structural aspects of the search space, which in turn depend on the move operator being used to modify solutions. A common way to characterize the search space of a problem is through the study of its fitness landscape, a mathematical object comprising the space of all possible solutions, their value with respect to the optimization objective, and a relationship of neighborhood defined by the move operator. The landscape metaphor is used to explain the search dynamics as a sort of potential function. The concept is indeed similar to that of potential energy surfaces in physical chemistry. Borrowing ideas from that field, we propose to extend to combinatorial landscapes the notion of the inherent network formed by energy minima in energy landscapes. In our case, energy minima are the local optima of the combinatorial problem, and we explore several definitions for the network edges. At first, we perform an exhaustive sampling of local optima basins of attraction, and define weighted transitions between basins by accounting for all the possible ways of crossing the basins frontier via one random move. Then, we reduce the computational burden by only counting the chances of escaping a given basin via random kick moves that start at the local optimum. Finally, we approximate network edges from the search trajectory of simple search heuristics, mining the frequency and inter-arrival time with which the heuristic visits local optima. Through these methodologies, we build a weighted directed graph that provides a synthetic view of the whole landscape, and that we can characterize using the tools of complex networks science. We argue that the network characterization can advance our understanding of the structural and dynamical properties of hard combinatorial landscapes. We apply our approach to prototypical problems such as the Quadratic Assignment Problem, the NK model of rugged landscapes, and the Permutation Flow-shop Scheduling Problem. We show that some network metrics can differentiate problem classes, correlate with problem non-linearity, and predict problem hardness as measured from the performances of trajectory-based local search heuristics.
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The objective of this master's thesis is to evaluate the optimum performance of sixsectored hexagonal layout of WCDMA (UMTS) network and analyze the performance at the optimum point. The maximum coverage and the maximum capacity are the main concern of service providers and it is always a challenging task for them to achieve economically. Because the optimum configuration of a network corresponds to a configuration which minimizes the number of sites required to provide a target service probability in the planning area which in turn reduces the deployment cost. The optimum performance means the maximum cell area and themaximum cell capacity the network can provide at the maximum antenna height satisfying the target service probability. Hexagon layout has been proven as the best layout for the cell deployment. In this thesis work, two different configurations using six-sectored sites have been considered for the performance comparison. In first configuration, each antenna is directed towards each corner of hexagon, whereas in second configurationeach antenna is directed towards each side of hexagon. The net difference in the configurations is the 30 degree rotation of antenna direction. The only indoor users in a flat and smooth semi-urban environment area have been considered for the simulation purpose where the traffic distribution is 100 Erl/km2 with 12.2 kbps speech service having maximum mobile speed of 3 km/hr. The simulation results indicate that a similar performance can be achieved in both the configurations, that is, a maximum of 947 m cellrange at antenna height of 49.5 m can be achieved when the antennas are directed towards the corner of hexagon, whereas 943.3 m cell range atantenna height of 54 m can be achieved when the antennas are directed towards the side of hexagon. However, from the interference point of view the first configuration provides better results. The simulation results also show that the network is coverage limited in both the uplink and downlink direction at the optimum point.
Resumo:
Rectangular hollow section (RHS) members are components widely used in engineering applications because of their good-looking, good properties in engineering areas and inexpensive cost comparing to members with other sections. The increasing use of RHS in load bearing structures makes it necessary to analyze the fatigue behavior of the RHS members. In this thesis, concentration will be given to the fatigue behavior of the RHS members under variable amplitude pure torsional loading. For the RHS members, failure will normally occur in the corner region if the welded regions are under full penetration. This is because of the complicated stress components' distributions at the RHScorners, where all of three fracture mechanics modes will happen. Mode I is mainly caused by the residual stresses that caused by the manufacturing process. Modes II and III are caused by the applied torsional loading. Stress based Findleymodel is also used to analyze the stress components. Constant amplitude fatigue tests have been done as well as variable amplitude fatigue tests. The specimens under variable amplitude loading gave longer fatigue lives than those under constant amplitude loading. Results from tests show an S-N curvewith slope around 5.
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Rsum: Les vipres du genre Vipera sont des serpents venimeux distribus dans la totalit du Palarctique. Malgr cette rpartition considrable, elles sont extrmement menaces, leur dclin tant principalement d la destruction et la fragmentation de leur habitat ainsi qu' la perscution humaine. Afin d'apporter de nouveaux lments dans le contexte de la protection de ce groupe de reptiles, nous avons utilis durant ce travail de thse diffrents marqueurs molculaires pour tudier la structuration gntique petite et large chelle chez trois espces appartenant au genre Vipera. La premire tude, une phylogographie molculaire de la vipre ammodytes (Vipera ammodytes), a montr dans l'ensemble de l'aire de rpartition une forte structuration gntique provenant d'isolements antrieures au Plistocne. La prsence d'un nombre important de clades dans le centre des Balkans suggre que cette rgion a fourni de nombreux refuges isols durant les glaciations. Ces dernires ont galement eu un impact considrable sur la diversit gntique au sein de la majorit des clades, suite d'importants goulots d'tranglement durant le Plistocne. L'tude de la phylogographie de la vipre aspic (Vipera aspis) a montr une diffrenciation gntique entre les populations prsentes de chaque ct des Alpes, mais galement une forte structuration interne avec la mise en vidence d'un refuge en France. Cette tude est la premire tablir clairement l'utilisation d'un refuge franais pour un vertbr terrestre. La troisime partie de cette thse a tudi la phylogographie de la vipre pliade (Vipera berus), espce cible de ce travail. En plus de la mise en vidence d'un groupe gntique inattendu (localis dans le nord de l'Italie, le sud de l'Autriche, le nord de la Slovnie et l'extrme sud-est de la Suisse), la variabilit gntique au sein du groupe nordique (comprenant les animaux de l'entier de l'aire de rpartition de l'espce l'exception des individus du groupe italien et les animaux provenant des Balkans) est suffisamment importante pour conclure l'utilisation de refuges glaciaires nordiques durant les dernires glaciations, en complment des refuges habituellement dcrits pour la majorit des espces animales (soit les pninsules ibrique, italienne et balakanique). Ces rsultats nous ont conduit effectuer une tude morphologique (quatrime partie) comparant les vipres pliades du "clade italien" et du "clade nordique" dcrits ci-dessus. Seules de petites diffrences morphologiques ont pu tre mises en vidence, malgr une sparation de ces groupes estime plus d'un million d'annes. Une tude plus petite chelle, centre sur le Massif jurassien et certaines populations alpines et franaises, a t entreprise afin d'estimer leur diversit gntique et d'valuer la structuration gntique entre les populations l'aide de marqueurs microsatellites (cinquime partie). Une importante structuration a t observe entre les populations distantes de plus de 3 kilomtres, la structuration entre les populations plus proches tant plus limite. De plus, une diversit gntique plus faible dans les populations jurassiennes et alpines comparativement aux populations du massif central et de la cte atlantique a t constate, probablement due une perte de diversit gntique lors de la recolonisation post-glaciaire. La sixime tude s'est intresse au succs reproducteur des mles de vipres pliades en conditions naturelles. Une corrlation entre la taille des mles et leur succs reproducteur a t releve, les individus de plus grande taille ayant un succs reproducteur plus lev. Le taux de multipaternit a aussi t investigu, dmontrant que la proportion de pontes issues de plusieurs pres est leve (69%) malgr la faible densit de vipres observe sur le site tudi. Finalement, aucun lien entre le nombre de pres au sein d'une ponte et la mortalit des jeunes la naissance n'a pu tre mis en vidence, contrastant avec des travaux prcdents. En conclusion, l'observation de la structuration trs marque chez les vipres pliades devrait permettre d'affiner les mthodes de protection de l'espce dans le massif jurassien. A plus large chelle, l'importante structuration gntique observe chez les vipres ammodytes, aspic et pliade rsultant de l'utilisation de nombreux refuges glaciaires, complmentaires aux refuges habituellement utiliss par les espces animales, dmontre l'intrt de l'analyse phylogographique des reptiles pour la comprhension des phnomnes de colonisation et d' extinction des populations durant la fin du Tertiaire et le Quaternaire. La mise en vidence chez les diffrentes espces de vipres tudies de nombreux groupes gntiques distincts (ESUs) devrait conduire des modifications de la taxonomie ainsi qu'au statut de protection de ces espces. Abstract: The vipers of the genus Vipera are venomous snakes widespread throughout the Palaearctic regions. Despite a large distribution area, several species are extremely threatened, especially due to the destruction and fragmentation of their habitats, as well as by human persecution. In order to increase the knowledge on these species and to improve their protection, several molecular markers have been used to investigate the genetic structure on small and large scales, within three species of the genus Vipera. The first study, a molecular phylogeography of the nose-horned viper (Vipera ammodytes), showed a considerable structuring throughout the distribution area, due to isolation into refugia before the Pleistocene. A high number of clades in the centre of the Balkans suggests that this region harboured numerous isolated glacial refugia during the last glaciation. Moreover, low genetic diversity within several clades implies that most populations of nose-horned vipers have suffered bottlenecks during the Pleistocene. The study of the phylogeography of the asp viper (Vipera aspis) showed genetic differentiation between populations on each side of the Alps, as well as considerable internal genetic structure, suggesting the use of a glacial refugium in France. This study is the first to establish firmly the occurrence of a French refugia for a terrestrial vertebrate. The third part of this work involved a phylogeographic study of the adder (Vipera berus), the target species of this thesis. Three clades were revealed: a Balkan clade (corresponding to the subspecies V. b. sachalinensis), an unexpected Italian clade (limited to northern Italy, southern Austria, northern Slovenia and southeasternmost corner of Switzerland) and a Northern clade clade (including adders of the whole distribution area excepted animals from the Balkan and the Italian clades). The genetic variability within the Northern clade is sufficiently high to conclude that a northern glacial refugia during the last glaciation, in addition to those refugia already described for the main species (Iberian, Italian and Balkan peninsula). These results motivated a morphological study (part four) comparing the adders from the Italian and the Northern clades describe above. Only small morphological differences have been found, despite the split between these two clades have taken place more than 1 million years ago. A study on a local scale, focused on the Jura Mountains, on a few populations in the Alps and France was, performed to estimate the genetic diversity and the genetic structure between populations using microsatellite markers (part five). Considerable structure was observed between populations separated by more than 3 kilometres, whereas the structure between closer populations is less marked. Moreover, lower genetic diversity in the populations from Jura Mountains and Alps was noticed compared to populations from Massif Central of Atlantic coast. Such loss of genetic variation probably followed post-glacial recolonisation. The sixth study focused on the reproductive success of male adders in the wild. A positive correlation between body length and reproductive success was observed. Multiple paternity was also observed in most of clutches (69%) despite the low density of adders in the study area. Finally, no relationship was found between the number of fathers in a clutch and the survival of offspring at birth, contradicting previous studies. To conclude, the observation of a significant genetic structure in Vipera berus will enable recommendations to be made to improve protection of this species in the Jura Mountain. On a larger scale, the considerable genetic structure found within Vipera ammdoytes, V. aspis and V. berus, resulting from isolation in additional glacial refugia to those already described for other species, demonstrates the relevance of phylogeographic studies of reptiles to better understand the colonisation and disappearance during the last Tertiary and the Quaternary. The observation of several groups of evolutionary significant units (ESUs) within the three studied species might lead to a revision of the taxonomy, as well as their conservation status.
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Small centrifugal compressors are more and more widely used in many industrialsystems because of their higher efficiency and better off-design performance comparing to piston and scroll compressors as while as higher work coefficient perstage than in axial compressors. Higher efficiency is always the aim of the designer of compressors. In the present work, the influence of four partsof a small centrifugal compressor that compresses heavy molecular weight real gas has been investigated in order to achieve higher efficiency. Two parts concern the impeller: tip clearance and the circumferential position of the splitter blade. The other two parts concern the diffuser: the pinch shape and vane shape. Computational fluid dynamics is applied in this study. The Reynolds averaged Navier-Stokes flow solver Finflo is used. The quasi-steady approach is utilized. Chien's k-e turbulence model is used to model the turbulence. A new practical real gas model is presented in this study. The real gas model is easily generated, accuracy controllable and fairly fast. The numerical results and measurements show good agreement. The influence of tip clearance on the performance of a small compressor is obvious. The pressure ratio and efficiency are decreased as the size of tip clearance is increased, while the total enthalpy rise keeps almost constant. The decrement of the pressure ratio and efficiency is larger at higher mass flow rates and smaller at lower mass flow rates. The flow angles at the inlet and outlet of the impeller are increased as the size of tip clearance is increased. The results of the detailed flow field show that leakingflow is the main reason for the performance drop. The secondary flow region becomes larger as the size of tip clearance is increased and the area of the main flow is compressed. The flow uniformity is then decreased. A detailed study shows that the leaking flow rate is higher near the exit of the impeller than that near the inlet of the impeller. Based on this phenomenon, a new partiallyshrouded impeller is used. The impeller is shrouded near the exit of the impeller. The results show that the flow field near the exit of the impeller is greatly changed by the partially shrouded impeller, and better performance is achievedthan with the unshrouded impeller. The loading distribution on the impeller blade and the flow fields in the impeller is changed by moving the splitter of the impeller in circumferential direction. Moving the splitter slightly to the suction side of the long blade can improve the performance of the compressor. The total enthalpy rise is reduced if only the leading edge of the splitter ismoved to the suction side of the long blade. The performance of the compressor is decreased if the blade is bended from the radius direction at the leading edge of the splitter. The total pressure rise and the enthalpy rise of thecompressor are increased if pinch is used at the diffuser inlet. Among the fivedifferent pinch shape configurations, at design and lower mass flow rates the efficiency of a straight line pinch is the highest, while at higher mass flow rate, the efficiency of a concave pinch is the highest. The sharp corner of the pinch is the main reason for the decrease of efficiency and should be avoided. The variation of the flow angles entering the diffuser in spanwise direction is decreased if pinch is applied. A three-dimensional low solidity twisted vaned diffuser is designed to match the flow angles entering the diffuser. The numerical results show that the pressure recovery in the twisted diffuser is higher than in a conventional low solidity vaned diffuser, which also leads to higher efficiency of the twisted diffuser. Investigation of the detailed flow fields shows that the separation at lower mass flow rate in the twisted diffuser is later than in the conventional low solidity vaned diffuser, which leads to a possible wider flow range of the twisted diffuser.
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Tyn tavoitteena oli vaaitusjrjestelmn kehittminen ITO 2005 Asrad-R ohjusjrjestelmn laukaisualustalle. Jrjestelmkontin jokaiseen kulmaan suunniteltiin nostojalat, joita voitiin knt sek nostaa ja laskea hydraulisesti. Jrjestelmn kuului mys hydraulikyttinen asetaso, jonka yl- ja ala-asennoilla oli erillinen lukitus. Trkein vaadittu toiminto oli jrjestelmkontin vaaitus maan vetovoiman suhteen eptasaisella alustalla sek maastossa ett kuorma-auton pll. Lisksi tarvittiin nostojalkojen nostoliikkeelle toiminto, jolla konttia nostetaan ja lasketaan siten, ett se silytt lhtkulmansa. Kaikkia nostojalkojen sylintereit oli mahdollista kytt mys yksittin. Jrjestelmll oli kovat ympristvaatimukset, koska se oli suunniteltu sotalaitteeksi rauhan ja kriisin aikaista toimintaa varten. Riittvt vapausasteet jrjestelmn toimimiseksi ajoneuvon apurungon pll saatiin nostojalkojen rotaatioliikkeen joustosta ja tassujen liukumisesta poikittain apurungon kiinnikkeiss. Maastossa nostojalat olivat tysin jykki ja liukuminen tapahtui tassujen ja maalevyjen vlill. Hydraulijrjestelmss kytettiin on/off-magneettiventtiilej, koska liikkeet olivat hitaita ja vaadittuun tarkkuuteen ja nopeuteen pstiin helposti. Keskeisi suunnittelun lhtkohtia olivat rakenteiden keveys, jrjestelmn yksinkertaisuus, hinta ja toimintavarmuus. Yksinkertaisella ja edullisella jrjestelmll saatiin aikaan hyvin toimiva ratkaisu.
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Tyss on tutkittu elementtimenetelmn avulla kylmmuovattujen nelikulmaisten putkipalkkien materiaalimallin kehittmist ja putkipalkkien X-liitosten jykkyyden ja rikestvyyden mrittmist. Tyn tavoitteena on tutkia kylmmuovauksen vaikutuksia putkipalkkiprofiilin materiaaliominaisuuksiin materiaalikokeiden ja elementtianalyysien avulla sek kehitt putkipalkille anisotrooppista materiaalimallia. Tyss mritettyj materiaalimalleja on sovellettu X-liitosten elementtimalleihin, joiden kyttytymist on verrattu rikestvyyskokeiden tuloksiin. Tutkimuksen perusteella Eurocode 3:n mitoitusohjeita voidaan turvallisesti soveltaa kylmmuovattujen putkipalkkien X-liitosten laskennassa. Tyss tehtyjen materiaalikokeiden ja elementtianalyysien perusteella materiaalin anisotrooppisuuden vaikutus liitoksen kestvyyteen on vhist, ja putkipalkin pituussuuntaista materiaalimallia voidaan soveltaa mys kehsuuntaisille materiaaliominaisuuksille. Materiaalikokeiden simulointi osoittaa, ett elementtimenetelm voidaan kytt materiaalimallin mrittmisen apuvlineen.
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Tyss tarkastellaan olemassa olevan suoraa vntmomentin st kyttvn taajuudenmuuttajan soveltamista keskitaajuusalueella toimiviin induktiomoottorikyttihin. Keskinopeusalueen sovellusten pyrimisnopeudet ovat tyypillisesti 600030000rpm. Tllin invertterin lhttaajuuden on nelinapaista moottoria ohjattaessa ulotuttava 1000Hz:iin. ABB:n ACS600 taajuudenmuuttajan nykyinen sytttaajuus ulottuu noin 400Hz:iin ja sen keskimrinen kytkenttaajuus on luokkaa 3kHz. Taajuudenmuuttajan keskimrist kytkenttaajuutta ei haluta tst merkittvsti nostaa, koska tllin pteasteen mitoitusta ja rakennetta on muutettava. Tarkastelussa keskitytn tten jnnitemodulointiin, joka mrittelee invertterin lhtjnnitteen kyrmuodon ja pteasteen tehokytkimien kytkenttaajuuden. Tyss esitetn suoran kmivuon sdn periaatetta soveltava 30-kulmainen modulointimenetelm (30-modulointi), jolla moottorin syttvirrasta voidaan eliminoida 5. ja 7. yliharmoninen komponentti. Yliharmonisten komponenttien eliminointi mahdollistaa passiivisilla komponenteilla toteutetun alipstsuodattimen asentamisen invertterin lhtn, jolloin moottorissa tapahtuvat tehohvit saadaan pieniksi. 30-moduloinnin ohjaukseen ja stn esitetn menetelmt, jotka mahdollistavat sen toteuttamisen nykyiseen taajuudenmuuttajaan ohjelmallisesti ilman suuria laitteistomuutoksia. 30-moduloinnin ominaisuuksia tarkastellaan analyyttisin menetelmin ja sen toimintaa testataan esitettyjen teorioiden perusteella simuloimalla. 30-moduloinnin ohjelmallinen implementointi nykyiseen ACS600:een mahdollistaa periaatteessa noin 600Hz:n sytttaajuuden saavuttamisen. Tllin invertterin keskimrinen kytkenttaajuus voidaan st koko pyrimisnopeusalueella alle 4kHz:n tasolle.
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Tyn tavoitteen oli selvitt mit erityspiirteit suomalaisissa listaamattomissa osakeyhtiiss on ja niiden pohjalta ymmrt minklainen hallituksen ja toimitusjohtajan vlinen suhde on. Tutkimusmetodologia oli empiirinen eksploratiivinen tutkimus ja tutkimusmenetelm oli kvalitatiivinen perustuen seitsemn teemahaastatteluun. Tutkimuksen tuloksena oli, ett osakeyhtit ovat erilaisia perustuen yhtin omistajamrn, omistuksen hajaantumiseen ja omistajien aktiivisuuteen. Psntisesti omistajat ovat lhell yhtin toimin- taa. Omistajat rakentavat yrityskulttuuria palkkaamalla hallituksen jseniksi kulloiseenkin tilanteeseen sopivimmat henkilt. Suomalaisia toimitusjohtajia pidetn ihmisksitykseltn psntisesti stewardeina ja ihmisksitykseen vaikuttaa olennaisesti kulttuurimme. Luottamus on hallituksen ja toimitusjohtajan vlisen suh- teen kulmakivi.
