76 resultados para Shaft Alignment
Resumo:
Leadership is essential for the effectiveness of the teams and organizations they are part of. The challenges facing organizations today require an exhaustive review of the strategic role of leadership. In this context, it is necessary to explore new types of leadership capable of providing an effective response to new needs. The presentday situations, characterized by complexity and ambiguity, make it difficult for an external leader to perform all leadership functions successfully. Likewise, knowledge-based work requires providing professional groups with sufficient autonomy to perform leadership functions. This study focuses on shared leadership in the team context. Shared leadership is seen as an emergent team property resulting from the distribution of leadership influence across multiple team members. Shared leadership entails sharing power and influence broadly among the team members rather than centralizing it in the hands of a single individual who acts in the clear role of a leader. By identifying the team itself as a key source of influence, this study points to the relational nature of leadership as a social construct where leadership is seen as social process of relating processes that are co-constructed by several team members. Based on recent theoretical developments concerned with relational, practice-based and constructionist approaches to the study of leadership processes, this thesis proposes the study of leadership interactions, working processes and practices to focus on the construction of direction, alignment and commitment. During the research process, critical events, activities, working processes and practices of a case team have been examined and analyzed with the grounded theory –approach in the terms of shared leadership. There are a variety of components to this complex process and a multitude of factors that may influence the development of shared leadership. The study suggests that the development process of shared leadership is a common sense -making process and consists of four overlapping dimensions (individual, social, structural, and developmental) to work with as a team. For shared leadership to emerge, the members of the team must offer leadership services, and the team as a whole must be willing to rely on leadership by multiple team members. For these individual and collective behaviors to occur, the team members must believe that offering influence to and accepting it from fellow team members are welcome and constructive actions. Leadership emerges when people with differing world views use dialogue and collaborative learning to create spaces where a shared common purpose can be achieved while a diversity of perspectives is preserved and valued. This study also suggests that this process can be supported by different kinds of meaning-making and process tools. Leadership, then, does not reside in a person or in a role, but in the social system. The built framework integrates the different dimensions of shared leadership and describes their relationships. This way, the findings of this study can be seen as a contribution to the understanding of what constitutes essential aspects of shared leadership in the team context that can be of theoretical value in terms of advancing the adoption and development process of shared leadership. In the real world, teams and organizations can create conditions to foster and facilitate the process. We should encourage leaders and team members to approach leadership as a collective effort that the team can be prepared for, so that the response is rapid and efficient.
Resumo:
Tutkimuksen tavoitteena on analysoida kokonaisratkaisuja tarjoavan järjestelmätoimittajan suorituskyvyn mittaamisen suunnittelua johdon päätöksenteon tukivälineeksi. Alitavoitteena oli suunnitella mittaristo case-yrityksen valitulle yksikölle sekä konsernitasolle. Tutkimuksen myötä havaittiin tarpeelliseksi tunnistaa järjestelmätoimittajan toimialatason vahvimmat ydinkyvykkyydet ja esittää ratkaisuja niiden mittaamiselle. Tutkimuksesta rajattiin mittariston hyödyntäminen yksilötason ohjauksessa. Tutkimusta lähestyttiin toiminta-analyyttisenä tapaustutkimuksena. Tutkimuksen yhteydessä määriteltiin järjestelmätoimittaja teollisen palveluliiketoiminnan toimijaksi, jonka mittaus painottuu asiakaslähtöisen toiminnan edistämiseen. Suurimmat haasteet muodostuivat aineettoman pääoman, pääosin uudistuvan ja uuden liiketoiminnan verkostojen mittaamisesta. Tutkimustuloksena voitiin havaita, että toimialatason keskeisimpiin ydinkyvykkyyksiin ja case-yrityksen linjaamiin menestystekijöihin pohjautunut tarkastelu onnistui tunnistamaan keskeisiä ongelmakohtia järjestelmätoimittajan mittariston suunnittelussa. Merkittävimmät toimenpidesuositukset ja laaditut mittariehdotukset painottavat asiakkaan prosessien tuntemista, oman osaamisen johtamista asiakkaan prosesseihin soveltuviksi, uusien innovaatioiden ja kyvykkyyksien luomista, erilaisten verkostojen tunnistamista ja kehittämistä, kyvykkyyksien johtamista ja tuotekeskeisen myynnin kehittämistä palvelukeskeiseen suuntaan. Tutkimus esittää näihin tuloksiin pohjautuvan mittariston ja prosessin aikana syntyneet mittariehdotukset.
Resumo:
This master’s thesis mainly focuses on the design requirements of an Electric drive for Hybrid car application and its control strategy to achieve a wide speed range. It also emphasises how the control and performance requirements are transformed into its design variables. A parallel hybrid topology is considered where an IC engine and an electric drive share a common crank shaft. A permanent magnet synchronous machine (PMSM) is used as an electric drive machine. Performance requirements are converted into Machine design variables using the vector model of PMSM. Main dimensions of the machine are arrived using analytical approach and Finite Element Analysis (FEA) is used to verify the design and performance. Vector control algorithm was used to control the machine. The control algorithm was tested in a low power PMSM using an embedded controller. A prototype of 10 kW PMSM was built according to the design values. The prototype was tested in the laboratory using a high power converter. Tests were carried out to verify different operating modes. The results were in agreement with the calculations.
Resumo:
Centrifugal pumps are a notable end-consumer of electrical energy. Typical application of a centrifugal pump is the filling or emptying of a reservoir tank, where the pump is often operated at a constant speed until the process is completed. Installing a frequency converter to control the motor substitutes the traditional fixed-speed pumping system, allows the optimization of rotational speed profile for the pumping tasks and enables the estimation of rotational speed and shaft torque of an induction motor without any additional measurements from the motor shaft. Utilization of variable-speed operation provides the possibility to decrease the overall energy consumption of the pumping task. The static head of the pumping process may change during the pumping task. In such systems, the minimum rotational speed changes during reservoir filling or emptying, and the minimum energy consumption can’t be achieved with a fixed rotational speed. This thesis presents embedded algorithms to automatically identify, optimize and monitor pumping processes between supply and destination reservoirs, and evaluates the changing static head –based optimization method.
Resumo:
Tutkielma on toimintatutkimus mentoroinnin kehittämisestä Osuuskauppa Hämeenmaassa. Tutkielman tavoitteena on ollut suunnitella mentorointiohjelma osuuskaupalle ja kehittää sen sisältöä saatujen tutkimustulosten perusteella sekä kuvata mentoroinnin tuomia hyötyjä ohjelman osallistujille ennen ohjelman päättymistä. Mentorointi on keskeinen osa S-ryhmän osaamisen johtamista. Sen avulla voidaan kehittää tärkeitä osaamisia ja suunnata oppimista organisaation tavoitteiden saavuttamiseksi. Mentorointi tukee henkilöstöstrategian mukaista omaehtoista oppimista, jossa yksilöt ottavat vastuun oman ammattitaitonsa ylläpitämisestä ja kehittämisestä organisaation tuella. Tutkielman viitekehykseen on koottu mentoroinnin ja mentorointiohjelman kehittämiseen liittyviä teorioita ja näkökulmia. Viitekehyksen pohjalta on suunniteltu mentorointiohjelman sisältö ja valmennusmateriaalit. Suunnittelu- ja toteutusprosessi on kuvattu tutkielmassa toimintatutkimuksen luonteen mukaisesti. Ohjelmaa ja sen tuomia hyötyjä osallistujille on arvioitu työssä kirjallisen palautekyselyn ja teemahaastatteluiden avulla. Tutkielman keskeisiä tuloksia ovat ohjelman suunnittelua tukeneen viite-kehyksen kokoaminen ja mentorointiohjelman toteuttaminen sille asetettujen tavoitteiden mukaisesti. Ohjelmaa on kehitetty tutkimustulosten perusteella ja tietoa mentoroinnin hyödyistä osallistujien näkökulmasta on kerätty.
Resumo:
Tässä väitöskirjassa tarkastellaan suurnopeustekniikan eri sovelluksissa ilmeneviä roottoreihin liittyviä rakenteellisia vaatimuksia ja haasteita. Tässä yhteydessä suurnopeustekniikalla tarkoitetaan järjestelyä, jossa sähkökone (moottori, generaattori) ja toimilaite (turbiini, kompressori, puhallin) on kytketty ilman vaihdetta suoraan mekaanisesti yhteen ja jossa yhteisen roottorin pyörimisnopeus on selvästi suurempi kuin 50/60 hertsin verkosta syötetyn kaksinapaisen vaihtovirtasähkökoneen tahtinopeus. Tyypillistä suurnopeuskoneen roottorille on suuri tehotiheys ja suuri mekaaninen kuormitus. Siksi esimerkiksi sähkökoneen jäähdytys on entistä haasteellisempaa kasvavien rautahäviöiden ja pienempien lämmönsiirtopinta-alojen vuoksi. Tämän työn tavoitteet voidaan jakaa kolmeen osaan: Yhdistetyn sähkö- ja turbokoneen roottorin mekaanisen rakenteen tarkastelu, jonka tavoitteena on pienentää lämmönkehitystä ja tehostaa kriittisten kohtien jäähdytystä. Tähän liittyy sähkömagneettisten häviöiden keskittäminen jäähdytyksen kannalta edullisiin kohtiin Yhdistetyn sähkö- ja turbokoneen roottorin mekaanisen rakenteen tarkastelu kriittisten ominaistaajuuksien kannalta Yhdistetyn sähkö- ja turbokoneen roottorin mekaanisen rakenteen analysointi lujuustekniseltä kannalta. Tähän liittyvät mm. erilaiset ahdistussovitteet ja niiden säilyminen korkeilla pyörimisnopeuksilla sekä niiden roottoria jäykistävä vaikutus ja lämmön johtuminen kyseisissä liitospinnoissa. Tämän työn tieteellinen uutuusarvo on nimenomaan yhdistetyn sähkö- ja turbokoneen roottorin rakenteen analysointi ottamalla samanaikaisesti huomioon kaikki edellä mainitut näkökohdat: jäähtyminen erityisen kuumissa kohdissa, sähköisten häviöiden alentaminen ja niiden jakautuman huomioon ottaminen, roottorin jäykkyyden maksimointi, lujuusrasitusten hallinta ja rakenteen mekaaninen stabiliteetti sekä lämpöteknisten ylimenovastusten tarkastelu.
Resumo:
Transport volumes have increased and will continue to increase in European Union. Even though the growth has not been equal between different transport modes. Most of the growth has been faced on road transport. European Union aims to balance the unbalanced market shares between the modes by gaining and supporting the competitiveness of railway and waterway transport. In EU railway transportation is seen as solution to increase safety in traffic and decrease the environmental impacts of transportation. The aim of this research is to figure out how it is possible to decrease the environmental impacts by the technology already in use. Main focus of this research is in intermodality and combining the road and railway transportation. This study aims also to figure out demands and expectations towards new Rail Baltica railway route connecting Tallinn and Berlin. The research is conducted by performing a literature review about decreasing environmental impacts and combining road and rail transport. Another viewpoint is taken from the possible effects of tourism to the passenger transport on rails. Knowledge gained by literature review is deepened by additional internet questionnaire study and expert interview study. In decreasing the environmental impacts of transportation electric trains are definitely the best option providing that the electricity is generated from renewable or carbon dioxide free sources. Decrease of environmental impacts has been reached also with acceptance of larger road transport vehicles. According to interviewed passenger transport experts, the whole route from Tallinn to Berlin may not be convenient to be used in passenger transport, just because the route is too long.. In EU freight is transported mainly with semi-trailer combinations, and that is why it could be logical if huckepack trains would be used on Rail Baltica. Huckepack train allows semi-trailers to be transported on rails with time efficient loading-unloading process. Overall, Rail Baltica project is experienced as a future-oriented one and new railway alignment is seen as great alternative option for transport modes using fossil fuels.
Resumo:
Ride comfort of elevators is one of the quality criteria valued by customers. The objective of this master’s thesis was to develop a process to measure the ride comfort of automatic elevator doors. The door’s operational noise was chosen as a focus area and other kinds of noise for example caused by pressure differences in the elevator shaft were excluded. The thesis includes a theory part and an empirical part. In the first part theories of quality management, measuring of quality and acoustics are presented. In the empirical part the developed ride comfort measuring process is presented, different operational noise sources are analyzed and an example is presented of how this measuring process can be used to guide product development. To measure ride comfort a process was developed where a two-room silent room was used as a measuring environment and EVA-625 device was used in the actual measuring of door noise. A-weighted decibels were used to scale noise pressure levels and the door movement was monitored with an accelerometer. This enabled the connection between the noise and noise sources which in turn helped to find potential ride comfort improvement ideas. The noise isolation class was also measured with the Ivie-measuring system. Measuring of door ride comfort gives feedback to product development and to managing current product portfolio. Measuring enables the continuous improvement of elevator door ride comfort. The measuring results can also be used to back up marketing arguments for doors.
Resumo:
Transportation of fluids is one of the most common and energy intensive processes in the industrial and HVAC sectors. Pumping systems are frequently subject to engineering malpractice when dimensioned, which can lead to poor operational efficiency. Moreover, pump monitoring requires dedicated measuring equipment, which imply costly investments. Inefficient pump operation and improper maintenance can increase energy costs substantially and even lead to pump failure. A centrifugal pump is commonly driven by an induction motor. Driving the induction motor with a frequency converter can diminish energy consumption in pump drives and provide better control of a process. In addition, induction machine signals can also be estimated by modern frequency converters, dispensing with the use of sensors. If the estimates are accurate enough, a pump can be modelled and integrated into the frequency converter control scheme. This can open the possibility of joint motor and pump monitoring and diagnostics, thereby allowing the detection of reliability-reducing operating states that can lead to additional maintenance costs. The goal of this work is to study the accuracy of rotational speed, torque and shaft power estimates calculated by a frequency converter. Laboratory tests were performed in order to observe estimate behaviour in both steady-state and transient operation. An induction machine driven by a vector-controlled frequency converter, coupled with another induction machine acting as load was used in the tests. The estimated quantities were obtained through the frequency converter’s Trend Recorder software. A high-precision, HBM T12 torque-speed transducer was used to measure the actual values of the aforementioned variables. The effect of the flux optimization energy saving feature on the estimate quality was also studied. A processing function was developed in MATLAB for comparison of the obtained data. The obtained results confirm the suitability of this particular converter to provide accurate enough estimates for pumping applications.
Resumo:
Työn tavoitteena oli mallintaa maastotyökoneen ajomoottorin hybridisointiin soveltuvan napavaihteiston dynamiikka. Työ tehtiin osana Saimaan ammattikorkeakoulun tutkimusprojektia, jonka tarkoituksena oli ajomoottorin ja integroidun napavaihteiston kaupallistaminen maastotyökoneisiin. Maastotyökoneena simulointimallissa käytettiin tyypillistä maataloustraktoria, johon kytkettiin vielä peräkärry. Traktorin renkaiden napaan oli kytketty ajomoottorina toimiva sähkömoottori, jonka sisään simuloitu napavaihteisto oli integroitu. Napavaihteiston dynamiikan mallintamiseen käytettiin monikappaledynamiikan simulointiohjelmistoa (Adams). Ohjelmalle määritettiin napavaihteiston komponenttien parametrit, joista voitiin simuloida vaihteiston dynaaminen käyttäytyminen. Simuloidusta mallista saatiin kytkimiin kohdistuvat voimat kytkentätilanteessa sekä sähkömoottorin väännön suunnanvaihtotilanteessa eri akselin pituuksilla, eri kytkinten nopeuseroilla, eri traktorin painoilla ja eri kuormilla ajettaessa. Mallissa simuloitiin myös sähkömoottorin käyttäytyminen vaihteenvaihtotilanteessa eri pyörimisnopeuden säätimen kertoimilla. Työssä huomattiin, että akselin mitoituksella voitiin vaikuttaa vaihteistossa ilmeneviin voimiin kytkimen kytkentähetkellä. Myös kytkimen hammastuksessa olevalla hammasvälyksellä voitiin vaikuttaa kytkimiin kohdistuviin voimiin suunnanvaihtotilanteissa. Vaihteistoon kohdistuvista voimista voidaan jatkossa suunnitella kytkimen ja akselin profiili, jotta vaihteisto kestää siihen kohdistuvat voimat.
Resumo:
This doctoral thesis presents a study on the design of tooth-coil permanent magnet synchronous machines. The electromagnetic properties of concentrated non-overlapping winding permanent magnet synchronous machines, or simply tooth-coil permanent magnet synchronous machines (TC-PMSMs), are studied in details. It is shown that current linkage harmonics play the deterministic role in the behavior of this type of machines. Important contributions are presented as regards of calculation of parameters of TC-PMSMs,particularly the estimation of inductances. The current linkage harmonics essentially define the air-gap harmonic leakage inductance, rotor losses and localized temporal inductance variation. It is proven by FEM analysis that inductance variation caused by the local temporal harmonic saturation results in considerable torque ripple, and can influence on sensorless control capabilities. Example case studies an integrated application of TC-IPMSMs in hybrid off-highway working vehicles. A methodology for increasing the efficiency of working vehicles is introduced. It comprises several approaches – hybridization, working operations optimization, component optimization and integration. As a result of component optimization and integration, a novel integrated electro-hydraulic energy converter (IEHEC) for off-highway working vehicles is designed. The IEHEC can considerably increase the operational efficiency of a hybrid working vehicle. The energy converter consists of an axial-piston hydraulic machine and an integrated TCIPMSM being built on the same shaft. The compact assembly of the electrical and hydraulic machines enhances the ability to find applications for such a device in the mobile environment of working vehicles.Usage of hydraulic fluid, typically used in working actuators, enables direct-immersion oil cooling of designed electrical machine, and further increases the torque- and power- densities of the whole device.
Resumo:
In recent years, chief information officers (CIOs) around the world have identified Business Intelligence (BI) as their top priority and as the best way to enhance their enterprises competitiveness. Yet, many enterprises are struggling to realize the business value that BI promises. This discrepancy causes important questions, for example: what are the critical success factors of Business Intelligence and, more importantly, how it can be ensured that a Business Intelligence program enhances enterprises competitiveness. The main objective of the study is to find out how it can be ensured that a BI program meets its goals in providing competitive advantage to an enterprise. The objective is approached with a literature review and a qualitative case study. For the literature review the main objective populates three research questions (RQs); RQ1: What is Business Intelligence and why is it important for modern enterprises? RQ2: What are the critical success factors of Business Intelligence programs? RQ3: How it can be ensured that CSFs are met? The qualitative case study covers the BI program of a Finnish global manufacturer company. The research questions for the case study are as follows; RQ4: What is the current state of the case company’s BI program and what are the key areas for improvement? RQ5: In what ways the case company’s Business Intelligence program could be improved? The case company’s BI program is researched using the following methods; action research, semi-structured interviews, maturity assessment and benchmarking. The literature review shows that Business Intelligence is a technology-based information process that contains a series of systematic activities, which are driven by the specific information needs of decision-makers. The objective of BI is to provide accurate, timely, fact-based information, which enables taking actions that lead to achieving competitive advantage. There are many reasons for the importance of Business Intelligence, two of the most important being; 1) It helps to bridge the gap between an enterprise’s current and its desired performance, and 2) It helps enterprises to be in alignment with key performance indicators meaning it helps an enterprise to align towards its key objectives. The literature review also shows that there are known critical success factors (CSFs) for Business Intelligence programs which have to be met if the above mentioned value is wanted to be achieved, for example; committed management support and sponsorship, business-driven development approach and sustainable data quality. The literature review shows that the most common challenges are related to these CSFs and, more importantly, that overcoming these challenges requires a more comprehensive form of BI, called Enterprise Performance Management (EPM). EPM links measurement to strategy by focusing on what is measured and why. The case study shows that many of the challenges faced in the case company’s BI program are related to the above-mentioned CSFs. The main challenges are; lack of support and sponsorship from business, lack of visibility to overall business performance, lack of rigid BI development process, lack of clear purpose for the BI program and poor data quality. To overcome these challenges the case company should define and design an enterprise metrics framework, make sure that BI development requirements are gathered and prioritized by business, focus on data quality and ownership, and finally define clear goals for the BI program and then support and sponsor these goals.
Resumo:
The interferometer for low resolution portable Fourier Transform middle infrared spectrometer was developed and studied experimentally. The final aim was a concept for a commercial prototype. Because of the portability, the interferometer should be compact sized and insensitive to the external temperature variations and mechanical vibrations. To minimise the size and manufacturing costs, Michelson interferometer based on plane mirrors and porch swing bearing was selected and no dynamic alignment system was applied. The driving motor was a linear voice coil actuator to avoid mechanical contact of the moving parts. The driving capability for low mirror driving velocities required by the photoacoustic detectors was studied. In total, four versions of such an interferometer were built and experimentally studied. The thermal stability during the external temperature variations and the alignment stability over the mirror travel were measured using the modulation depth of the wide diameter laser beam. Method for estimating the mirror tilt angle from the modulation depth was developed to take account the effect from the non-uniform intensity distribution of the laser beam. The spectrometer stability was finally studied also using the infrared radiation. The latest interferometer was assembled for the middle infrared spectrometer with spectral range from 750 cm−1 to 4500 cm−1. The interferometer size was (197 × 95 × 79) mm3 with the beam diameter of 25 mm. The alignment stability as the change of the tilt angle over the mirror travel of 3 mm was 5 μrad, which decreases the modulation depth only about 0.7 percent in infrared at 3000 cm−1. During the temperature raise, the modulation depth at 3000 cm−1 changed about 1 . . . 2 percentage units per Celsius over short term and even less than 0.2 percentage units per Celsius over the total temperature raise of 30 °C. The unapodised spectral resolution was 4 cm−1 limited by the aperture size. The best achieved signal to noise ratio was about 38 000:1 with commercially available DLaTGS detector. Although the vibration sensitivity requires still improving, the interferometer performed, as a whole, very well and could be further developed to conform all the requirements of the portable and stable spectrometer.
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The usage of digital content, such as video clips and images, has increased dramatically during the last decade. Local image features have been applied increasingly in various image and video retrieval applications. This thesis evaluates local features and applies them to image and video processing tasks. The results of the study show that 1) the performance of different local feature detector and descriptor methods vary significantly in object class matching, 2) local features can be applied in image alignment with superior results against the state-of-the-art, 3) the local feature based shot boundary detection method produces promising results, and 4) the local feature based hierarchical video summarization method shows promising new new research direction. In conclusion, this thesis presents the local features as a powerful tool in many applications and the imminent future work should concentrate on improving the quality of the local features.