900 resultados para Wireless Control systems, feedback scheduling, cross-layer, event-triggered
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In a previous work, a hybrid system consisting of an advanced oxidation process (AOP) named Photo-Fenton (Ph-F) and a fixed bed biological treatment operating as a sequencing batch biofilm reactor (SBBR) was started-up and optimized to treat 200 mg·L-1 of 4-chlorophenol (4-CP) as a model compound. In this work, studies of reactor stability and control as well as microbial population determination by molecular biology techniques were carried out to further characterize and control the biological reactor. Results revealed that the integrated system was flexible and even able to overcome toxic shock loads. Oxygen uptake rate (OUR) in situ was shown to be a valid tool to control the SBBR operation, to detect toxic conditions to the biomass, and to assess the recovery of performance. A microbial characterization by 16S rDNA sequence analysis reveals that the biological population was varied, although about 30% of the bacteria belonged to the Wautersia genus.
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Verkostokeskeisessä sodankäynnissä tietojärjestelmien suurimpana haasteena on oikean tiedon hajauttaminen oikeaan paikkaan ja aikaan. Tietojärjestelmissä esitettävän ilmatilannekuvan tulee vastata reaalimaailman tilannetta parhaalla mahdollisella tavalla. Ilmatorjunnassa reaaliaikaisuus nousee erityisen suureen rooliin nopeasti liikkuvien kohteiden takia. Tämä diplomityö on tehty Insta DefSec Oy:ssä liittyen johtamisjärjestelmän uudistamishankkeeseen. Työn vaatimuksina olivat standardeihin perustuvat ratkaisut, joista keskeisimmäksi nousi Data Distribution Service -standardi (DDS) ja sen hyödyntäminen osana johtamisjärjestelmän tiedon hajautusta. Työssä esitellään johtamisjärjestelmien tiedon hajautukseen liittyviä haasteita sekä paikallisessa että maantieteellisesti hajautetussa toimintaympäristössä. Työssä toteutettiin liityntäohjelmisto nykyisen ja uuden johtamisjärjestelmän välille. Liityntäohjelmiston tehtävänä on tuottaa reaaliaikaista ilmatilannekuvaa nykyisestä johtamisjärjestelmästä uuteen johtamisjärjestelmään. DDS-standardin toteuttavana välikerrosarkkitehtuurina käytettiin OpenSplice DDS -tuotetta. Valittu teknologia tarjoaa edistykselliset julkaisija–tilaaja-mallin mukaiset menetelmät tiedon reaaliaikaiseen hajauttamiseen. DDS:n arkkitehtuuri ja palvelun laadun mekanismit mahdollistavat tiedon hajautuksen sodanajan johtamisjärjestelmille.
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Tehdyssä kirjallisuus- ja teoriakatsauksessa vuosien 2006 - 2010 välisenä aikana, Keski-Suomessa toimivan konepajateollisuuden järjestelmätoimittajayrityksen toimeksiannosta, pyrittiin muodostamaan kokonaiskuva laajasta tuotannonsuunnittelun ja -ohjauksen aihealueesta. Perustutkimuskysymykset liittyivät ns. MPC-systeemiin, jolla tarkoitetaan sitä, että tuotannonsuunnittelu- ja ohjauskysymyksissä on huomioitava aina henkilöiden, organisaation, teknologioiden ja prosessien muodostama kokonaisuus. Operatiivisen johtamisen tehtävänä on yrityksen tuotteita koskevan kysynnän ja tarjonnan tasapainottaminen niin, että resursseja käytettäisiin ja tarvittaisiin mahdollisimman vähän vastattaessa kysyntään asiakasvaatimukset huomioiden. Tuotantostrategian pohjalta on voitava rakentaa MPC-systeemi, jonka avulla ja jota kehittäen tuotanto saavuttaisi sille asetetut suorituskykytavoitteet mm. kustannusten, laadun, nopeuden, luotettavuuden sekä tuottavuuskehityksen osalta. Työssä tarkasteltiin yleisen kolmitasoisen viitekehyksen kautta ”perinteisistä MPC-systeemien perusratkaisuista” hierarkkisia, suunnittelu- ja laskentaintensiiviä, MRP-pohjaisia sekä yksinkertaistamiseen ja nopeuteen perustuvia JIT/Lean -menetelmiä. Tämä viitekehys käsittää: 1) kysynnän- ja resurssien hallinnan, 2) yksityiskohtaisemman kapasiteetin ja materiaalien hallinnan sekä 3) tarkemman tuotannon ja hankintojen ohjauksen sekä tuotannon lattiatason osa-alueet. Johtamisen ja MPC-systeemien kehittämisen ”uusina aaltoina ja näkökulmina” raportissa käsiteltiin myös johtamisen eri koulukuntia sekä em. viitekehyksen pohjalta tarvittavia tietojärjestelmiä. Olennaisimpana johtopäätöksenä todettiin, että MRP-pohjaisten ratkaisujen lisäksi, etenkin monimutkaisia tuotteita tilausohjautuvasti valmistavien kappaletavarateollisuuden yritysten, on mahdollisesti hyödynnettävä myös kehittyneempiä suunnittelu- ja ohjausjärjestelmiä. Lisäksi huomattiin, että ”perinteisten strategioiden” rinnalle yritysten on nostettava myös tieto- ja viestintäteknologiastrategiat. On tärkeää ymmärtää, että täydellistä MPC-systeemiä ei ole vielä keksitty: jokaisen yrityksen tehtäväksi ja vastuulle jää ”oman totuutensa” muodostaminen ja systeeminsä rakentaminen sen pohjalta.
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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.
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In this thesis a closer look at ZigBee wireless network protocol was made and a ZigBee evaluation device was designed and built for testing it. ZigBee is a digital wireless network technology published in 2004, which was developed for wireless control and automation systems. It is based on the IEEE 802.15.4-2003 standard, and its aim was to create a reliable wireless networking protocol with secure data transmissions, low power consumption and low manufacturing costs. The low power consumption requirement has also led to a slow data rate and a short range, but in a ZigBee network individual network devices can route messages to each other, so short range is not a problem. In automation and control systems a fast data rate is not usually an important requirement either. ZigBee network can form automatically and one ZigBee network can theoretically include thousands of devices, all of which can communicate with each other. ZigBee network is also self-healing, so an individual device dropping out of the network, like breaking down, does not affect functionality of the network. Evaluation device was designed and implemented in four different versions, which were tested with six different antenna designs. All antennas were tested at a range of 100 meters in an open terrain using two different frequencies and transmission powers. Also a range test was performed for selected antennas using transmission power of 4,5 dBm, which was maximum power of the ZigBee chip used in the evaluation device. Range test resulted in a measured range of several hundred meters, which can be considered as a good result for a short-range technology.
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This work describes a lumped parameter mathematical model for the prediction of transients in an aerodynamic circuit of a transonic wind tunnel. Control actions to properly handle those perturbations are also assessed. The tunnel circuit technology is up to date and incorporates a novel feature: high-enthalpy air injection to extend the tunnels Reynolds number capability. The model solves the equations of continuity, energy and momentum and defines density, internal energy and mass flow as the basic parameters in the aerodynamic study as well as Mach number, stagnation pressure and stagnation temperature, all referred to test section conditions, as the main control variables. The tunnel circuit response to control actions and the stability of the flow are numerically investigated. Initially, for validation purposes, the code was applied to the AWT ("Altitude Wind Tunnel" of NASA-Lewis). In the sequel, the Brazilian transonic wind tunnel was investigated, with all the main control systems modeled, including injection.
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RFID on radioaaltoja hyväksikäyttävä langaton kommunikointitekniikka, jota käytetään tunnistamaan tunnisteella merkittyjä esineitä tai ihmisiä yksilöinä. RFID on jo pitkään ollut tunnettu tekniikka, mutta vasta viime vuosikymmeninä sitä on alettu hyödyntämään kaupallisesti eri sovellusaloilla. Kandidaatintyön tarkoituksena on tehdä yleiskatsaus RFID:n historiaan, järjestelmien osiin ja niiden toimintaan sekä kartoittaa RFID-markkinoiden nykytilaa ja lähitulevaisuutta sekä globaalilta kannalta että Suomessa. Lopuksi työssä tarkastellaan RFID-perusteisten kulunvalvontajärjestelmien perusominaisuuksia ja niiden toimintaa.
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The purpose of this study is to explore the possibilities of utilizing business intelligence (BI)systems in management control (MC). The topic of this study is explored trough four researchquestions. Firstly, what kind of management control systems (MCS) use or could use the data and information enabled by the BI system? Secondly, how the BI system is or could be utilized? Thirdly, has BI system enabled new forms of control or changed old ones? The fourth and final research question is whether the BI system supports some forms of control that the literature has not thought of, or is the BI system not used for some forms of control the literature suggests it should be used? The study is conducted as an extensive case study. Three different organizations were interviewed for the study. For the theoretical basis of the study, central theories in the field of management control are introduced. The term business intelligence is discussed in detail and the mechanisms for governance of business intelligence are presented. A literature analysis of the uses of BI for management control is introduced. The theoretical part of the study ends in the construction of a framework for business intelligence in management control. In the empirical part of the study the case organizations, their BI systems, and the ways they utilize these systems for management control are presented. The main findings of the study are that BI systems can be utilized in the fields suggested in the literature, namely in planning, cybernetic, reward, boundary, and interactive control. The systems are used both as the data or information feeders and directly as the tools. Using BI systems has also enabled entirely new forms of control in the studied organizations, most significantly in the area of interactive control. They have also changed the old control systems by making the information more readily available to the whole organization. No evidence of the BI systems being used for forms of control that the literature had not suggested was found. The systems were mostly used for cybernetic control and interactive control, whereas the support for other types of control was not as prevalent. The main contribution of the study to the existing literature is the insight provided into how BI systems, both theoretically and empirically, are used for management control. The framework for business intelligence in management control presented in the study can also be utilized in further studies about the subject.
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Adaptive control systems are one of the most significant research directions of modern control theory. It is well known that every mechanical appliance’s behavior noticeably depends on environmental changes, functioning-mode parameter changes and changes in technical characteristics of internal functional devices. An adaptive controller involved in control process allows reducing an influence of such changes. In spite of this such type of control methods is applied seldom due to specifics of a controller designing. The work presented in this paper shows the design process of the adaptive controller built by Lyapunov’s function method for the Hydraulic Drive. The calculation needed and the modeling were conducting with MATLAB® software including Simulink® and Symbolic Math Toolbox™ etc. In the work there was applied the Jacobi matrix linearization of the object’s mathematical model and derivation of the suitable reference models based on Newton’s characteristic polynomial. The intelligent adaptive to nonlinearities algorithm for solving Lyapunov’s equation was developed. Developed algorithm works properly but considered plant is not met requirement of functioning with. The results showed confirmation that adaptive systems application significantly increases possibilities in use devices and might be used for correction a system’s behavior dynamics.
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Several studies have reported impairment in cardiovascular function and control in diabetes. The studies cited in this review were carried out from a few days up to 3 months after streptozotocin administration and were concerned with the control of the circulation. We observed that early changes (5 days) in blood pressure control by different peripheral receptors were maintained for several months. Moreover, the impairment of reflex responses observed after baroreceptor and chemoreceptor stimulation was probably related to changes in the efferent limb of the reflex arc (sympathetic and parasympathetic), but changes also in the central nervous system could not be excluded. Changes in renal sympathetic nerve activity during volume expansion were blunted in streptozotocin-treated rats, indicating an adaptive natriuretic and diuretic response in the diabetic state. The improvement of diabetic cardiovascular dysfunction induced by exercise training seems to be related to changes in the autonomic nervous system. Complementary studies about the complex interaction between circulation control systems are clearly needed to adequately address the management of pathophysiological changes associated with diabetes.
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Due to various advantages such as flexibility, scalability and updatability, software intensive systems are increasingly embedded in everyday life. The constantly growing number of functions executed by these systems requires a high level of performance from the underlying platform. The main approach to incrementing performance has been the increase of operating frequency of a chip. However, this has led to the problem of power dissipation, which has shifted the focus of research to parallel and distributed computing. Parallel many-core platforms can provide the required level of computational power along with low power consumption. On the one hand, this enables parallel execution of highly intensive applications. With their computational power, these platforms are likely to be used in various application domains: from home use electronics (e.g., video processing) to complex critical control systems. On the other hand, the utilization of the resources has to be efficient in terms of performance and power consumption. However, the high level of on-chip integration results in the increase of the probability of various faults and creation of hotspots leading to thermal problems. Additionally, radiation, which is frequent in space but becomes an issue also at the ground level, can cause transient faults. This can eventually induce a faulty execution of applications. Therefore, it is crucial to develop methods that enable efficient as well as resilient execution of applications. The main objective of the thesis is to propose an approach to design agentbased systems for many-core platforms in a rigorous manner. When designing such a system, we explore and integrate various dynamic reconfiguration mechanisms into agents functionality. The use of these mechanisms enhances resilience of the underlying platform whilst maintaining performance at an acceptable level. The design of the system proceeds according to a formal refinement approach which allows us to ensure correct behaviour of the system with respect to postulated properties. To enable analysis of the proposed system in terms of area overhead as well as performance, we explore an approach, where the developed rigorous models are transformed into a high-level implementation language. Specifically, we investigate methods for deriving fault-free implementations from these models into, e.g., a hardware description language, namely VHDL.
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This thesis describes the development and analysis of an Isosceles Trapezoidal Dielectric Resonator Antenna (ITDRA) by realizing different DR orientations with suitable feed configurations enabling it to be used as multiband, dual band dual polarized and wideband applications. The motivation for this work has been inspired by the need for compact, high efficient, low cost antenna suitable for multi band application, dual band dual polarized operation and broadband operation with the possibility of using with MICs, and to ensure less expensive, more efficient and quality wireless communication systems. To satisfy these challenging demands a novel shaped Dielectric Resonator (DR) is fabricated and investigated for the possibility of above required properties by trying out different orientations of the DR on a simple microstrip feed and with slotted ground plane as well. The thesis initially discusses and evaluates recent and past developments taken place within the microwave industry on this topic through a concise review of literature. Then the theoretical aspects of DRA and different feeding techniques are described. Following this, fabrication and characterization of DRA is explained. To achieve the desired requirements as above both simulations and experimental measurements were undertaken. A 3-D finite element method (FEM) electromagnetic simulation tool, HFSSTM by Agilent, is used to determine the optimum geometry of the dielectric resonator. It was found to be useful in producing approximate results although it had some limitations. A numerical analysis technique, finite difference time domain (FDTD) is used for validating the results of wide band design at the end. MATLAB is used for modeling the ITDR and implementing FDTD analysis. In conclusion this work offers a new, efficient and relatively simple alternative for antennas to be used for multiple requirements in the wireless communication system.
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In Wireless Sensor Networks (WSN), neglecting the effects of varying channel quality can lead to an unnecessary wastage of precious battery resources and in turn can result in the rapid depletion of sensor energy and the partitioning of the network. Fairness is a critical issue when accessing a shared wireless channel and fair scheduling must be employed to provide the proper flow of information in a WSN. In this paper, we develop a channel adaptive MAC protocol with a traffic-aware dynamic power management algorithm for efficient packet scheduling and queuing in a sensor network, with time varying characteristics of the wireless channel also taken into consideration. The proposed protocol calculates a combined weight value based on the channel state and link quality. Then transmission is allowed only for those nodes with weights greater than a minimum quality threshold and nodes attempting to access the wireless medium with a low weight will be allowed to transmit only when their weight becomes high. This results in many poor quality nodes being deprived of transmission for a considerable amount of time. To avoid the buffer overflow and to achieve fairness for the poor quality nodes, we design a Load prediction algorithm. We also design a traffic aware dynamic power management scheme to minimize the energy consumption by continuously turning off the radio interface of all the unnecessary nodes that are not included in the routing path. By Simulation results, we show that our proposed protocol achieves a higher throughput and fairness besides reducing the delay
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Shrimp grow out systems under zero water exchange mode demand constant remediation of total ammonia nitrogen (TAN) andNO2 −–Nto protect the crop. To address this issue, aninexpensive and user-friendly technology using immobilized nitrifying bacterial consortia (NBC) as bioaugmentors has been developed and proposed for adoption in shrimp culture systems. Indigenous NBC stored at 4 °C were activated at room temperature (28 °C) and cultured in a 2 L bench top fermentor. The consortia, after enumeration by epifluorescence microscopy,were immobilized on delignifiedwood particles of a soft wood tree Ailantus altissima (300–1500 μm) having a surface area of 1.87m2 g−1. Selection of wood particle as substratumwas based on adsorption of NBC on to the particles, biofilm formation, and their subsequent nitrification potential. The immobilization could be achievedwithin 72 h with an initial cell density of 1×105 cells mL−1. On experimenting with the lowest dosage of 0.2 g (wet weight) immobilized NBC in 20 L seawater, a TAN removal rate of 2.4 mg L−1 within three days was observed. An NBC immobilization device could be developed for on site generation of the bioaugmentor preparation as per requirement. The product of immobilization never exhibited lag phase when transferred to fresh medium. The extent of nitrification in a simulated systemwas two times the rate observed in the control systems suggesting the efficacy in real life situations. The products of nitrification in all experiments were undetectable due to denitrifying potency, whichmade the NBC an ideal option for biological nitrogen removal. The immobilized NBC thus generated has been named TANOX (Total Ammonia Nitrogen Oxidizer)
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Aquest projecte pretén presentar de forma clara i detallada l’estructura i el funcionament del robot així com dels components que el conformen. Aquesta informació és de vital importància a l’hora de desenvolupar aplicacions per al robot. Un cop descrites les característiques del robot s’analitzaran les eines necessàries i/o disponibles per poder desenvolupar programari per cada nivell de la forma més senzilla i eficient possible. Posteriorment s’analitzaran els diferents nivells de programació i se’n contrastaran els avantatges i els inconvenients de cada un. Aquest anàlisi es començarà fent pel nivell més alt i anirà baixant amb la intenció de no entrar en nivells més baixos del necessari. Baixar un nivell en la programació suposa haver de crear aplicacions sempre compatibles amb els nivells superiors de forma que com més es baixa més augmenta la complexitat. A partir d’aquest anàlisi s’ha arribat a la conclusió que per tal d’aprofitar totes les prestacions del robot és precís arribar a programar en el nivell més baix del robot. Finalment l’objectiu és obtenir una sèrie de programes per cada nivell que permetin controlar el robot i fer-lo seguir senzilles trajectòries