86 resultados para Pulse Measurement
Resumo:
Tämän tutkimuksen tavoitteena oli selvittää, pitäisikö trimmihävikin kustannukset lisätä case yrityksen asiakaskannattavuuslaskelmaan. Trimmihävikin vaihtelua asiakkaiden välillä tutkittiin yhdellä case yrityksen tuotantolinjalla. Myös tilaustekijöiden sekä ajankohdan vaikutusta trimmihävikin määrään selvitettiin. Teoreettinen viitekehys rakennettiin asiakaskannattavuuden ja asiakassuhteiden johtamisen ympärille. Tutkimuksen empiirisessä osassa hyödynnettiin kvantitatiivista tutkimusmenetelmää ja tilastollisissa analyyseissä käytettiin laajaa aineistoa. Tulokset osoittivat, että trimmihävikin määrä vaihteli asiakkaiden kesken. Asiakkaista muodostettiin kolme klusteria. Näiden klustereiden tarkempi tutkiminen osoitti selvän yhteyden asiakkaan ostokäyttäytymisen ja trimmihävikin välillä. Lopuksi tutkimuksen tulosten hyödyntämismahdollisuuksia pohdittiin ja myös tutkimuksen rajoitukset tunnistettiin.
Resumo:
Tämä tutkimus pyrkii selvittämään, miten toimitusketjun suorituskykyä voidaan mitata kohdeyrityksessä. Supply Chain Council (SCC) on vuonna 1996 kehittänyt Supply Chain Operations Reference (SCOR) – mallin, joka mahdollistaa myös suorituskyvyn mittaamisen. Tämän tutkimuksen tarkoituksena on soveltaa SCOR-mallin suorituskyvyn mittausmallia kohdeyrityksessä. Työ on kvalitatiivinen tapaustutkimus. Työn teoriaosassa on pääasiallisesti käsitelty toimitusketjua ja suorituskyvyn mittaamista koskevaa kirjallisuutta. Mittausjärjestelmän luominen alkaa kohdeyrityksen esittelyllä. SCOR – mallin mittarit on kohdeyrityksessä rakennettu SCC:n ehdotusten mukaisesti, jotta mittareiden tulokset olisivat käyttökelpoisia myös benchmarkkausta varten. Malli sisältää 10 SCOR – mittaria, sekä muutamia muita Haltonin omia mittareita. Lopputuloksena voidaan nähdä, että SCOR – malli antaa hyvän yleiskuvan toimitusketjun suorituskyvystä, mutta kohdeyrityksessä on silti tarvetta kehittää edelleen informatiivisempia mittareita, jotka antaisivat yksityiskohtaisempaa tietoa kohdeyrityksen johdolle.
Resumo:
Induction motors are widely used in industry, and they are generally considered very reliable. They often have a critical role in industrial processes, and their failure can lead to significant losses as a result of shutdown times. Typical failures of induction motors can be classified into stator, rotor, and bearing failures. One of the reasons for a bearing damage and eventually a bearing failure is bearing currents. Bearing currents in induction motors can be divided into two main categories; classical bearing currents and inverter-induced bearing currents. A bearing damage caused by bearing currents results, for instance, from electrical discharges that take place through the lubricant film between the raceways of the inner and the outer ring and the rolling elements of a bearing. This phenomenon can be considered similar to the one of electrical discharge machining, where material is removed by a series of rapidly recurring electrical arcing discharges between an electrode and a workpiece. This thesis concentrates on bearing currents with a special reference to bearing current detection in induction motors. A bearing current detection method based on radio frequency impulse reception and detection is studied. The thesis describes how a motor can work as a “spark gap” transmitter and discusses a discharge in a bearing as a source of radio frequency impulse. It is shown that a discharge, occurring due to bearing currents, can be detected at a distance of several meters from the motor. The issues of interference, detection, and location techniques are discussed. The applicability of the method is shown with a series of measurements with a specially constructed test motor and an unmodified frequency-converter-driven motor. The radio frequency method studied provides a nonintrusive method to detect harmful bearing currents in the drive system. If bearing current mitigation techniques are applied, their effectiveness can be immediately verified with the proposed method. The method also gives a tool to estimate the harmfulness of the bearing currents by making it possible to detect and locate individual discharges inside the bearings of electric motors.
Resumo:
The purpose of this thesis was to investigate creating and improving category purchasing visibility for corporate procurement by utilizing financial information. This thesis was a part of the global category driven spend analysis project of Konecranes Plc. While creating general understanding for building category driven corporate spend visibility, the IT architecture and needed purchasing parameters for spend analysis were described. In the case part of the study three manufacturing plants of Konecranes Standard Lifting, Heavy Lifting and Services business areas were examined. This included investigating the operative IT system architecture and needed processes for building corporate spend visibility. The key findings of this study were the identification of the needed processes for gathering purchasing data elements while creating corporate spend visibility in fragmented source system environment. As an outcome of the study, roadmap presenting further development areas was introduced for Konecranes.
Resumo:
The research around performance measurement and management has focused mainly on the design, implementation and use of performance measurement systems. However, there is little evidence about the actual impacts of performance measurement on the different levels of business and operations of organisations, as well as the underlying factors that lead to a positive impact of performance measurement. The study thus focuses on this research gap, which can be considered both important and challenging to cover. The first objective of the study was to examine the impacts of performance measurement on different aspects of management, leadership and the quality of working life, after which the factors that facilitate and improve performance and performance measurement at the operative level of an organisation were examined. The second objective was to study how these factors operate in practice. The third objective focused on the construction of a framework for successful operative level performance measurement and the utilisation of the factors in the organisations. The research objectives have been studied through six research papers utilising empirical data from three separate studies, including two sets of interview data and one of quantitative data. The study applies mainly the hermeneutical research approach. As a contribution of the study, a framework for successful operative level performance measurement was formed by matching the findings of the current study and performance measurement theory. The study extents the prior research regarding the impacts of performance measurement and the factors that have a positive effect on operative level performance and performance measurement. The results indicate that under suitable circumstances, performance measurement has positive impacts on different aspects of management, leadership, and the quality of working life. The results reveal that for example the perception of the employees and the management of the impacts of performance measurement on leadership style differ considerably. Furthermore, the fragmented literature has been reorganised into six factors that facilitate and improve the performance of the operations and employees, and the use of performance measurement at the operative level of an organisation. Regarding the managerial implications of the study, managers who operate around performance measurement can utilise the framework for example by putting the different phases of the framework into practice.
Resumo:
This thesis was produced for the Technology Marketing unit at the Nokia Research Center. Technology marketing was a new function at Nokia Research Center, and needed an established framework with the capacity to take into account multiple aspects for measuring the team performance. Technology marketing functions had existed in other parts of Nokia, yet no single method had been agreed upon for measuring their performance. The purpose of this study was to develop a performance measurement system for Nokia Research Center Technology Marketing. The target was that Nokia Research Center Technology Marketing had a framework for separate metrics; including benchmarking for starting level and target values in the future planning (numeric values were kept confidential within the company). As a result of this research, the Balanced Scorecard model of Kaplan and Norton, was chosen for the performance measurement system for Nokia Research Center Technology Marketing. This research selected the indicators, which were utilized in the chosen performance measurement system. Furthermore, performance measurement system was defined to guide the Head of Marketing in managing Nokia Research Center Technology Marketing team. During the research process the team mission, vision, strategy and critical success factors were outlined.
Resumo:
This thesis presents the calibration and comparison of two systems, a machine vision system that uses 3 channel RGB images and a line scanning spectral system. Calibration. is the process of checking and adjusting the accuracy of a measuring instrument by comparing it with standards. For the RGB system self-calibrating methods for finding various parameters of the imaging device were developed. Color calibration was done and the colors produced by the system were compared to the known colors values of the target. Software drivers for the Sony Robot were also developed and a mechanical part to connect a camera to the robot was also designed. For the line scanning spectral system, methods for the calibrating the alignment of the system and the measurement of the dimensions of the line scanned by the system were developed. Color calibration of the spectral system is also presented.
Resumo:
Aims:This study was carried out to evaluate the feasibility of two different methods to determine free flap perfusion in cancer patients undergoing major reconstructive surgery. The hypotheses was that low perfusion in the flap is associated with flap complications. Patients and methods: Between August 2002 and June 2008 at the Department of Otorhinolaryngology – Head and Neck Surgery, Department of Surgery, and at the PET Centre, Turku, 30 consecutive patients with 32 free flaps were included in this study. The perfusion of the free microvascular flaps was assessed with positron emission tomography (PET) and radioactive water ([15O] H2O) in 40 radiowater injections in 33 PET studies. Furthermore, 24 free flaps were monitored with a continuous tissue oxygen measurement using flexible polarographic catheters for an average of three postoperative days. Results: Of the 17 patients operated on for head and neck (HN) cancer and reconstructed with 18 free flaps, three re-operations were carried out due to poor tissue oxygenation as indicated by ptiO2 monitoring results and three other patients were reoperated on for postoperative hematomas in the operated area. Blood perfusion assessed with PET (BFPET) was above 2.0 mL / min / 100 g in all flaps and a low flap-to-muscle BFPET ratio appeared to correlate with poor survival of the flap. Survival in this group of HN cancer patients was 9.0 months (median, range 2.4-34.2) after a median follow-up of 11.9 months (range 1.0-61.0 months). Seven HN patients of this group are alive without any sign of recurrence and one patient has died of other causes. All of the 13 breast reconstruction patients included in the study are alive and free of disease at a median follow-up time of 27.4 months (range 13.9-35.7 months). Re-explorations were carried out in three patients due data provided by ptiO2 monitoring and one re-exploration was avoided on the basis of adequate blood perfusion assessed with PET. Two patients had donorsite morbidity and 3 patients had partial flap necrosis or fat necrosis. There were no total flap losses. Conclusions: PtiO2 monitoring is a feasible method of free flap monitoring when flap temperature is monitored and maintained close to the core temperature. When other monitoring methods give controversial results or are unavailable, [15O] H2O PET technique is feasible in the evaluation of the perfusion of the newly reconstructed free flaps.
Resumo:
Various strength properties of paper are measured to tell how well it resists breaks in a paper machine or in printing presses. The most often measured properties are dry tensile strength and dry tear strength. However, in many situations where paper breaks, it is not dry. For example, in web breaks after the wet pressing the dry matter content can be around 45%. Thus, wet-web strength is often a more critical paper property than dry strength. Both wet and dry strength properties of the samples were measured with a L&W tensile tester. Originally this device was not designed for the measurement of the wet web tensile strength, thus a new procedure to handle the wet samples was developed. The method was tested with Pine Kraft (never dried). The effect of different strength additives on the wet-web and dry paper tensile strength was studied. The polymers used in this experiment were aqueous solution of a cationic polyamidoamine-epichlorohydrin resin (PAE), cationic hydrophilised polyisocyanate and cationic polyvinylamine (PVAm). From all three used chemicals only Cationic PAE considerably increased the wet web strength. However it was noticed that at constant solids content all chemicals decreased the wet web tensile strength. So, since all chemicals enhanced solid content it can be concluded that they work as drainage aids, not as wet web strength additives. From all chemicals only PVAm increased the dry strength and two other chemicals even decreased the strength. As chemicals were used in strong diluted forms and were injected into the pulp slurry, not on the surface of the papersheets, changes in samples densities did not happen. Also it has to be noted that all these chemicals are mainly used to improve the wet strength after the drying of the web.
Resumo:
The objective of the thesis was to create a performance measurement system for the logistics process of a company. In addition, one goal was to make suggestions for improvements based on description and analysis of the process and current measures. The logistics process was described in detail, and the objectives for it were derived from the company strategy and goals. Suggestions for performance measurement system and process improvement were made based on current state analysis. As a result of the thesis, three new performance measures were decided to take into use. In addition, several improvements were suggested to the ERP system to make process smoother. Some of the improvements have already been added to the system and the rest will be added in the near future.
Resumo:
The objective of this study is to create measurement system that is capable to measure performance in basic industry’s service centers. First it is examined what is performance and how it can be measured. The study also introduces commonly known measurement frameworks. After theory the study investigates how companies in the field of basic industry measure their operations in practise. The investigation is done examining three case examples and by analyzing survey results from basic industry companies. On the survey results focus is on what meters and measurement systems companies use. It is also viewed what measurement problems companies have faced. In the applied part of the study harmonized performance measurement system is created. The framework of the measurement system is introduced and measurement system for the target company is created. The target company felt that the harmonized performance measurement system has good potential and continues to develop it further.
Resumo:
Supersonic axial turbine stages typically exhibit lower efficiencies than subsonic axial turbine stages. One reason for the lower efficiency is the occurrence of shock waves. With higher pressure ratios the flow inside the turbine becomes relatively easily supersonic if there is only one turbine stage. Supersonic axial turbines can be designed in smaller physical size compared to subsonic axial turbines of same power. This makes them good candidates for turbochargers in large diesel engines, where space can be a limiting factor. Also the production costs are lower for a supersonic axial turbine stage than for two subsonic stages. Since supersonic axial turbines are typically low reaction turbines, they also create lower axial forces to be compensated with bearings compared to high reaction turbines. The effect of changing the stator-rotor axial gap in a small high (rotational) speed supersonic axial flow turbine is studied in design and off-design conditions. Also the effect of using pulsatile mass flow at the supersonic stator inlet is studied. Five axial gaps (axial space between stator and rotor) are modeled using threedimensional computational fluid dynamics at the design and three axial gaps at the off-design conditions. Numerical reliability is studied in three independent studies. An additional measurement is made with the design turbine geometry at intermediate off-design conditions and is used to increase the reliability of the modelling. All numerical modelling is made with the Navier-Stokes solver Finflo employing Chien’s k ¡ ² turbulence model. The modelling of the turbine at the design and off-design conditions shows that the total-to-static efficiency of the turbine decreases when the axial gap is increased in both design and off-design conditions. The efficiency drops almost linearily at the off-design conditions, whereas the efficiency drop accelerates with increasing axial gap at the design conditions. The modelling of the turbine stator with pulsatile inlet flow reveals that the mass flow pulsation amplitude is decreased at the stator throat. The stator efficiency and pressure ratio have sinusoidal shapes as a function of time. A hysteresis-like behaviour is detected for stator efficiency and pressure ratio as a function of inlet mass flow, over one pulse period. This behaviour arises from the pulsatile inlet flow. It is important to have the smallest possible axial gap in the studied turbine type in order to maximize the efficiency. The results for the whole turbine can also be applied to some extent in similar turbines operating for example in space rocket engines. The use of a supersonic stator in a pulsatile inlet flow is shown to be possible.
Resumo:
Identification of product requirements and quality, together with the management of production are key issues in chemical engineering. Quality control of crystalline products is part of the quality of many industrially manufactured products like paper, paintings, medicines and fertilizers. In most crystallization cases, quality is described with the size, polymorph, shape and purity of the crystal. The chemical composition, hydrodynamics and driving force, together with the operating temperature are in a key position when the properties of a crystalline product are controlled with the crystallization process. This study concentrates on managing the identified properties of a crystalline product with the control of a driving force. The controlling of the driving force can be based on the change of solubility or the change of concentration. Solubility can be changed with temperature, pressure and an antisolvent. The concentration of crystallizing compound, the solute can be changed with the evaporation of the solvent and with the addition of a reagent. The present study focuses on reagent addition and temperature change as methods of changing the level of the driving force. Three control structures for direct control of supersaturation are built, one for cooling crystallization and two for reactive crystallization. Closed loop feedback control structures are based on the measurement of the solute concentration with attenuated total reflection - Fourier transform infrared spectrometer. The details of the reagent feed are analyzed with experimental studies and with results of computational fluid dynamic simulations of the inert particle pulse in the premixer and inert particle injection to the mixing tank. Nucleation in conditions of controlled reactive crystallization is analyzed with Nielsen’s equation of homogeneous nucleation. The resulting control systems, based on regulation of supersaturation, can be used to produce the desired polymorph of an organic product. The polymorph composition of product crystals is controlled repeatably with the decision of a set value of supersaturation level.