966 resultados para Allometric Scaling
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Adapting and scaling up agile concepts, which are characterized by iterative, self-directed, customer value focused methods, may not be a simple endeavor. This thesis concentrates on studying challenges in a large-scale agile software development transformation in order to enhance understanding and bring insight into the underlying factors for such emerging challenges. This topic is approached through understanding the concepts of agility and different methods compared to traditional plan-driven processes, complex adaptive theory and the impact of organizational culture on agile transformational efforts. The empirical part was conducted by a qualitative case study approach. The internationally operating software development case organization had a year of experience of an agile transformation effort during it had also undergone organizational realignment efforts. The primary data collection was conducted through semi-structured interviews supported by participatory observation. As a result the identified challenges were categorized under four broad themes: organizational, management, team dynamics and process related. The identified challenges indicate that agility is a multifaceted concept. Agile practices may bring visibility in issues of which many are embedded in the organizational culture or in the management style. Viewing software development as a complex adaptive system could facilitate understanding of the underpinning philosophy and eventually solving the issues: interactions are more important than processes and solving a complex problem, such a novel software development, requires constant feedback and adaptation to changing requirements. Furthermore, an agile implementation seems to be unique in nature, and agents engaged in the interaction are the pivotal part of the success of achieving agility. In case agility is not a strategic choice for whole organization, it seems additional issues may arise due to different ways of working in different parts of an organization. Lastly, detailed suggestions to mitigate the challenges of the case organization are provided.
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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
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This work aimed to develop allometric equations for tree biomass estimation, and to determine the site biomass in different "cerrado" ecosystems. Destructive sampling in a "campo cerrado" (open savanna) was carried out at the Biological Reserve of Moji-Guaçu, State of São Paulo, southeastern Brazil. This "campo cerrado" (open savanna) grows under a tropical climate and on acid, low nutrient soils. Sixty wood plants were cut to ground level and measurements of diameter, height and weight of leaves and stems were taken. We selected the best equations among the most commonly used mathematical relations according to R² values, significance, and standard error. Both diameter (D) and height (H) showed good relationship with plant biomass, but the use of these two parameters together (DH and D²H) provided the best predictor variables. The best equations were linear, but power and exponential equations also showed high R² and significance. The applicability of these equations is discussed and biomass estimates are compared with other types of tropical savannas. Mineralmass was also estimated. "Cerrados" proved to have very important carbon reservoirs due to their great extent. In addition, high land-use change that takes place nowadays in the "cerrado" biome may significantly affect the global carbon cycle.
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One of the main challenges in Software Engineering is to cope with the transition from an industry based on software as a product to software as a service. The field of Software Engineering should provide the necessary methods and tools to develop and deploy new cost-efficient and scalable digital services. In this thesis, we focus on deployment platforms to ensure cost-efficient scalability of multi-tier web applications and on-demand video transcoding service for different types of load conditions. Infrastructure as a Service (IaaS) clouds provide Virtual Machines (VMs) under the pay-per-use business model. Dynamically provisioning VMs on demand allows service providers to cope with fluctuations on the number of service users. However, VM provisioning must be done carefully, because over-provisioning results in an increased operational cost, while underprovisioning leads to a subpar service. Therefore, our main focus in this thesis is on cost-efficient VM provisioning for multi-tier web applications and on-demand video transcoding. Moreover, to prevent provisioned VMs from becoming overloaded, we augment VM provisioning with an admission control mechanism. Similarly, to ensure efficient use of provisioned VMs, web applications on the under-utilized VMs are consolidated periodically. Thus, the main problem that we address is cost-efficient VM provisioning augmented with server consolidation and admission control on the provisioned VMs. We seek solutions for two types of applications: multi-tier web applications that follow the request-response paradigm and on-demand video transcoding that is based on video streams with soft realtime constraints. Our first contribution is a cost-efficient VM provisioning approach for multi-tier web applications. The proposed approach comprises two subapproaches: a reactive VM provisioning approach called ARVUE and a hybrid reactive-proactive VM provisioning approach called Cost-efficient Resource Allocation for Multiple web applications with Proactive scaling. Our second contribution is a prediction-based VM provisioning approach for on-demand video transcoding in the cloud. Moreover, to prevent virtualized servers from becoming overloaded, the proposed VM provisioning approaches are augmented with admission control approaches. Therefore, our third contribution is a session-based admission control approach for multi-tier web applications called adaptive Admission Control for Virtualized Application Servers. Similarly, the fourth contribution in this thesis is a stream-based admission control and scheduling approach for on-demand video transcoding called Stream-Based Admission Control and Scheduling. Our fifth contribution is a computation and storage trade-o strategy for cost-efficient video transcoding in cloud computing. Finally, the sixth and the last contribution is a web application consolidation approach, which uses Ant Colony System to minimize the under-utilization of the virtualized application servers.
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The present study examined the floristic composition of three fragments of Araucaria Forest (AF) in the Planalto Catarinense region of southern Brazil as well as the floristic contextualization of these areas in relation to other remnant AF sites. Three AF fragments at different altitudes were analyzed in the municipalities of Campos Novos, Lages, and Painel. Fifty 200 m² plots were examined in each fragment and all of the trees with CBH (circumference at breast height) > 15.7 cm were identified. In order to floristically contextualize the study fragments, comparisons were made with other remnant AF sites by way of dendrograms and NMDS (Non-metric multidimensional scaling). Environmental and spatial variables were plotted on the diagram produced by the NMDS to evaluate their influence on the floristic patterns encountered. The forest fragments studied demonstrated high floristic heterogeneity, indicating that AFs cannot be considered homogeneous formations and they could be classified into 3 phytogeographical categories: i) high altitude areas influenced by cloud cover/fog, including the Painel region; ii) areas of lesser altitude and greater mean annual temperatures situated in the Paraná River basin, and iii) areas situated in the Paraná and Upper-Uruguay river basins and the smaller basins draining directly into the southern Atlantic, near Campos Novos and Lages. The environmental variables most highly correlated with species substitutions among the sites were altitude, mean annual temperature, and the mean temperature of the most humid trimester.
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In this work, the feasibility of the floating-gate technology in analog computing platforms in a scaled down general-purpose CMOS technology is considered. When the technology is scaled down the performance of analog circuits tends to get worse because the process parameters are optimized for digital transistors and the scaling involves the reduction of supply voltages. Generally, the challenge in analog circuit design is that all salient design metrics such as power, area, bandwidth and accuracy are interrelated. Furthermore, poor flexibility, i.e. lack of reconfigurability, the reuse of IP etc., can be considered the most severe weakness of analog hardware. On this account, digital calibration schemes are often required for improved performance or yield enhancement, whereas high flexibility/reconfigurability can not be easily achieved. Here, it is discussed whether it is possible to work around these obstacles by using floating-gate transistors (FGTs), and analyze problems associated with the practical implementation. FGT technology is attractive because it is electrically programmable and also features a charge-based built-in non-volatile memory. Apart from being ideal for canceling the circuit non-idealities due to process variations, the FGTs can also be used as computational or adaptive elements in analog circuits. The nominal gate oxide thickness in the deep sub-micron (DSM) processes is too thin to support robust charge retention and consequently the FGT becomes leaky. In principle, non-leaky FGTs can be implemented in a scaled down process without any special masks by using “double”-oxide transistors intended for providing devices that operate with higher supply voltages than general purpose devices. However, in practice the technology scaling poses several challenges which are addressed in this thesis. To provide a sufficiently wide-ranging survey, six prototype chips with varying complexity were implemented in four different DSM process nodes and investigated from this perspective. The focus is on non-leaky FGTs, but the presented autozeroing floating-gate amplifier (AFGA) demonstrates that leaky FGTs may also find a use. The simplest test structures contain only a few transistors, whereas the most complex experimental chip is an implementation of a spiking neural network (SNN) which comprises thousands of active and passive devices. More precisely, it is a fully connected (256 FGT synapses) two-layer spiking neural network (SNN), where the adaptive properties of FGT are taken advantage of. A compact realization of Spike Timing Dependent Plasticity (STDP) within the SNN is one of the key contributions of this thesis. Finally, the considerations in this thesis extend beyond CMOS to emerging nanodevices. To this end, one promising emerging nanoscale circuit element - memristor - is reviewed and its applicability for analog processing is considered. Furthermore, it is discussed how the FGT technology can be used to prototype computation paradigms compatible with these emerging two-terminal nanoscale devices in a mature and widely available CMOS technology.
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The performance measurement produces information about the operation of the business process. On the basis of this information performance of the company can be followed and improved. Balanced performance measurement system can monitor performance of several perspectives and business processes can be led according to company strategy. Major part of the costs of a company is originated from purchased goods or services are an output of the buying process emphasising the importance of a reliable performance measurement of purchasing process. In the study, theory of balanced performance measurement is orientated and framework of purchasing process performance measurement system is designed. The designed balanced performance measurement system of purchasing process is tested in case company paying attention to the available data and to other environmental enablers. The balanced purchasing performance measurement system is tested and improved during the test period and attention is paid to the definition and scaling of objectives. Found development initiatives are carried out especially in the scaling of indicators. Finally results of the study are evaluated, conclusions and additional research areas proposed.
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Tässä työssä esiteltiin Android laitteisto- ja sovellusalustana sekä kuvattiin, kuinka Android-pelisovelluksen käyttöliittymä voidaan pitää yhtenäisenä eri näyttölaitteilla skaalauskertoimien ja ankkuroinnin avulla. Toisena osiona työtä käsiteltiin yksinkertaisia tapoja, joilla pelisovelluksien suorituskykyä voidaan parantaa. Näistä tarkempiin mittauksiin valittiin matalatarkkuuksinen piirtopuskuri ja näkymättömissä olevien kappaleiden piilotus. Mittauksissa valitut menetelmät vaikuttivat demosovelluksen suorituskykyyn huomattavasti. Tässä työssä rajauduttiin Android-ohjelmointiin Java-kielellä ilman ulkoisia kirjastoja, jolloin työn tuloksia voi helposti hyödyntää mahdollisimman monessa eri käyttökohteessa.
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This thesis presents point-contact measurements between superconductors (Nb, Ta, Sn,Al, Zn) and ferromagnets (Co, Fe, Ni) as well as non-magnetic metals (Ag, Au, Cu, Pt).The point contacts were fabricated using the shear method. The differential resistanceof the contacts was measured either in liquid He at 4.2 K or in vacuum in a dilutionrefrigerator at varying temperature down to 0.1 K. The contact properties were investigatedas function of size and temperature. The measured Andreev-reflection spectrawere analysed in the framework of the BTK model – a three parameter model that describescurrent transport across a superconductor - normal conductor interface. Theoriginal BTK model was modified to include the effects of spin polarization or finitelifetime of the Cooper pairs. Our polarization values for the ferromagnets at 4.2 K agree with the literature data, but the analysis was ambiguous because the experimental spectra both with ferromagnets and non-magnets could be described equally well either with spin polarization or finite lifetime effects in the BTK model. With the polarization model the Z parametervaries from almost 0 to 0.8 while the lifetime model produces Z values close to 0.5. Measurements at lower temperatures partly lift this ambiguity because the magnitude of thermal broadening is small enough to separate lifetime broadening from the polarization. The reduced magnitude of the superconducting anomalies for Zn-Fe contacts required an additional modification of the BTK model which was implemented as a scaling factor. Adding this parameter led to reduced polarization values. However, reliable data is difficult to obtain because different parameter sets produce almost identical spectra.
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Reverse osmosis and nanofiltration are among the most effective and widely used desalination and water softening technologies. They can also be used to treat mining wastewaters and are capable of producing water of extremely high purity, regardless of the high concentrations of toxic heavy metals and extreme pH and salinity. However, challenges with recovering the salts and metals from mining wastewaters in exploitable form, as well as problems with scaling still limit the process efficiency and the ratio of purified water recoverable from process waters. To address the problem of membrane scaling caused by calcium sulfate, batch filtration experiments with the Desal-5 DL nanofiltration membrane, three commercial antiscalants and actual mine process water from a copper mine were performed. The aim of these experiments was to find process conditions where maximum water recovery would be achieved before significant scaling or irreversible membrane fouling would occur and to further improve water recovery by addition of antiscalants. Water recovery of 70 % was reached with the experimental setups by optimizing process conditions. PC-504T antiscaling agent was determined to be the most effective of the three antiscalants used and the addition of 5 ppm of PC-504T allowed the water recovery to be further increased from 70 % to 85 % before major scaling was observed. In these conditions 92 % calcium rejection was achieved.
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We performed a quantitative analysis of M and P cell mosaics of the common-marmoset retina. Ganglion cells were labeled retrogradely from optic nerve deposits of Biocytin. The labeling was visualized using horseradish peroxidase (HRP) histochemistry and 3-3'diaminobenzidine as chromogen. M and P cells were morphologically similar to those found in Old- and New-World primates. Measurements were performed on well-stained cells from 4 retinas of different animals. We analyzed separate mosaics for inner and outer M and P cells at increasing distances from the fovea (2.5-9 mm of eccentricity) to estimate cell density, proportion, and dendritic coverage. M cell density decreased towards the retinal periphery in all quadrants. M cell density was higher in the nasal quadrant than in other retinal regions at similar eccentricities, reaching about 740 cells/mm² at 2.5 mm of temporal eccentricity, and representing 8-14% of all ganglion cells. P cell density increased from peripheral to more central regions, reaching about 5540 cells/mm² at 2.5 mm of temporal eccentricity. P cells represented a smaller proportion of all ganglion cells in the nasal quadrant than in other quadrants, and their numbers increased towards central retinal regions. The M cell coverage factor ranged from 5 to 12 and the P cell coverage factor ranged from 1 to 3 in the nasal quadrant and from 5 to 12 in the other quadrants. These results show that central and peripheral retinal regions differ in terms of cell class proportions and dendritic coverage, and their properties do not result from simply scaling down cell density. Therefore, differences in functional properties between central and peripheral vision should take these distinct regional retinal characteristics into account.
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A 3-bp insertion/deletion polymorphism in intron 6 of GSTM3 (rs1799735, GSTM3*A/*B) affects the activity of the phase 2 xenobiotic metabolizing enzyme GSTM3 and has been associated with increased cancer risk. The GSTM3*B allele is rare or absent in Southeast Asians, occurs in 5-20% of Europeans but was detected in 80% of Bantu from South Africa. The wide genetic diversity among Africans led us to investigate whether the high frequency of GSTM3*B prevailed in other sub-Saharan African populations. In 168 healthy individuals from Angola, Mozambique and the São Tomé e Príncipe islands, the GSTM3*B allele was three times more frequent (0.74-0.78) than the GSTM3*A allele (0.22-0.26), with no significant differences in allele frequency across the three groups. We combined these data with previously published results to carry out a multidimensional scaling analysis, which provided a visualization of the worldwide population affinities based on the GSTM3 *A/*B polymorphism.
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In the last decades, the chemical synthesis of short oligonucleotides has become an important aspect of study due to the discovery of new functions for nucleic acids such as antisense oligonucleotides (ASOs), aptamers, DNAzymes, microRNA (miRNA) and small interfering RNA (siRNA). The applications in modern therapies and fundamental medicine on the treatment of different cancer diseases, viral infections and genetic disorders has established the necessity to develop scalable methods for their cheaper and easier industrial manufacture. While small scale solid-phase oligonucleotide synthesis is the method of choice in the field, various challenges still remain associated with the production of short DNA and RNA-oligomers in very large quantities. On the other hand, solution phase synthesis of oligonucleotides offers a more predictable scaling-up of the synthesis and is amenable to standard industrial manufacture techniques. In the present thesis, various protocols for the synthesis of short DNA and RNA oligomers have been studied on a peracetylated and methylated β-cyclodextrin, and also on a pentaerythritol-derived support. On using the peracetylated and methylated β-cyclodextrin soluble supports, the coupling cycle was simplified by replacement of the typical 5′-O-(4,4′-dimethoxytrityl) protecting group with an acid-labile acetal-protected 5′-O-(1-methoxy-1-methylethyl) group, which upon acid-catalyzed methanolysis released easily removable volatile products. For this reason monomeric building blocks 5′-O-(1-methoxy-1-methylethyl) 3′-(2-cyano-ethyl-N,N-diisopropylphosphoramidite) were synthesized. Alternatively, on using the precipitative pentaerythritol support, novel 2´-O-(2-cyanoethyl)-5´-O-(1-methoxy-1-methylethyl) protected phosphoramidite building blocks for RNA synthesis have been prepared and their applicability by the synthesis of a pentamer was demonstrated. Similarly, a method for the preparation of short RNAs from commercially available 5´-O-(4,4´-dimethoxytrityl)-2´-O-(tert-butyldimethyl-silyl)ribonucleoside 3´-(2-cyanoethyl-N,N-diisopropylphosphoramidite) building blocks has been developed
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Työn aiheena on vaihteen pienoismallin suunnittelu ja toteutus 3d-tulostusta hyväksi käyttäen. Pienoismalli tehdään Moventas Gears Oy:n suunnittelemasta tuuliturbiinin vaihteesta. Vaihteen pienentämisestä johtuen malliin on suunniteltava uudet laakeripesät ja hammaspyörät. 3D-tulostuksen ja pienoismallin pienen koon ansiosta vaihdetta voidaan yksinkertaistaa suuresti ja näin vähentää tulostettavien osien määrää. Lisäksi työssä selvitetään, mitä ongelmia 3D-tulostus tuo valmistukseen ja suunnitteluun. Työn kirjallisessa osassa selvennetään planeettavaihteen toimintaa yleisesti sekä esitellään Exceed Series 3+ vaihdetta. Lisäksi kerrotaan 3D-tulostuksesta, sen periaatteesta, erilaisista tulostusmenetelmistä, tulostinlaitteesta ja mahdollisista ongelmista tulostuksessa. Kokeellinen osa koostuu pienoismallin suunnittelusta ja valmistuksesta. Valmistuksessa olleiden virheiden takia muutama osa jouduttiin tulostamaan uudelleen. Muutamia osia jouduttiin myös hieman jälkikäsittelemään tulostuksen jälkeen, jotta malli saatiin kasattua. Ongelmakohdaksi muodostui tulostimen ohjelmisto ja tulostustiedostot. Tulostusprosessi sujui kuitenkin hyvin. Lopputuloksena saatiin toimiva pienoismalli. 3D-tulostus toimii hyvin monimutkaisten kappaleiden tulostuksessa. Tulostuksen hinta nousi kuitenkin varsin korkeaksi. Tulostuslaitteistosta riippuen tulostuksen voisi mahdollisesti suorittaa myös halvemmallakin.
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Kotkan jakelualueella käytetään historiallisista syistä keskijänniteverkossa kahta jänniteta-soa, 10 kV ja 20 kV. Eri jännitetasojen lisäksi Kotkan jakelualueen 110/20 päämuuntajien kytkentäryhmänä on käytössä YNyn0, kun taas muualla verkossa käytetään YNd11 kyt-kentäryhmää. Jännitetasoista ja kytkentäryhmistä johtuen Kotkan jakeluverkon yhteenkyt-kettävyys ympäröivän verkon kanssa on haastavaa. Työn tavoitteena on selvittää Kotkan kaupungin keskijänniteverkon nykytila ja käytettä-vyys häiriötilanteissa pahimpana mahdollisena aikana, sekä löytää mahdolliset ongelma-kohdat. Verkon nykytila tarkasteltiin verkkotietojärjestelmän avulla käyttäen laskennallisia tuloksia, jotka skaalattiin vastaamaan kovemman pakkastalven kuormitusta. Skaalaus teh-tiin useamman vuoden takaiseen tilanteeseen, jolloin yleinen taloustilanne oli parempi ja verkon kuormitus suurempi, jolloin verkko ei tule alimitoitetuksi taloustilanteen parantuessa. Tulevaisuuden varalta muodostettiin alueen tulevaisuuden kuormitusennusteet käyttämällä historiatietoja sekä tulevaisuuden näkymiä apuna. Työn keskeisimmäksi sisällöksi muodostui selvittää tarve usean käyttöjännitteen säilyttä-miselle sekä erilaisten kytkentäryhmien ylläpitämiseen ja kosketusjänniteongelman ratkai-seminen. Alueen sähköverkon kehittämiseksi tehtiin useita eri vaihtoehtoja, joita vertailtiin elinkaarikustannusperiaatteella toisiinsa. Vertailun pohjalta saatiin investointistrategia ehdo-tukset, joiden pohjalta verkkoyhtiö voi tehdä tulevaisuuteen sijoittuvia ratkaisuja.