Dissertations / Theses: 'Buffer capacity'

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Edge, Johann. "Effects of exercise training on muscle buffer capacity and H? regulation." University of Western Australia. School of Human Movement and Exercise Science, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0043.

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[ Truncated abstract] The purpose of this series of studies was to further our understanding of the relationship between muscle buffer capacity and training. Study one was performed to determine if there were differences in muscle buffer capacity (βmin-vitro) between females of differing training status (i.e., team-sport, endurance-trained and untrained subjects). Studies two and three were then performed to determine if short-term training could improve muscle buffer capacity and what type of training best improves this muscle characteristic (i.e., high-intensity, moderate-intensity or resistance training). Studies four and five were performed to determine if the accumulation of H+ during exercise was a mechanism by which training improved muscle buffer capacity. Below is a summary of these five studies. Study 1. The team-sport group had a significantly higher βmin-vitro than either the endurance-trained or the untrained groups (181 ± 27 v 148 ± 11 v 122 ± 32 'mol H+?g dm-1?pH-1 respectively; P<0.05). The team-sport group also completed significantly more relative total work (299 ± 27 v 263 ± 31 v 223 ± 21 J?kg-1, respectively; P<0.05) and absolute total work (18.2 ± 1.6 v 14.6 ± 2.4 v 13.0 ± 1.9 kJ, respectively; P<0.05) than the endurance-trained or untrained groups during a repeated sprint ability (RSA) test. There was a significant correlation between βmin-vitro and RSA (r=0.67; P<0.05). These findings show that young females competing in team sports have a larger βmin-vitro than either endurance-trained or untrained females. This may be the result of the intermittent, high-intensity activity during training and the match play of team-sport athletes... Conclusions. Our results show that training intensity is an important determinant of muscle buffer capacity. High-intensity interval training (120-150% LT) improved muscle buffer capacity (9 27%), however, neither moderate-intensity or resistance training improved muscle buffer capacity. In contrast higher training intensity (150-180% LT) may negatively affect muscle buffer capacity. Differences in the accumulation of H+ during high-intensity interval training does not appear to be the underlying mechanism for changes to muscle buffer capacity, however changes to this muscle characteristic were associated with pre-training muscle buffer capacity.

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Gu, Yingying, and 顾莹莹. "Electrokinetic remediation of cadmium-contaminated natural clay of high buffer capacity." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46279015.

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Edge, Johann. "Effects of exercise training on muscle buffer capacity and H+ regulation /." Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0043.

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Gandhi, Sahir. "Lab-on-a-chip device to quantify buffer capacity of blood." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/34399.

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An accurate estimation of physiological buffer capacity and total titratable buffer concentration of blood can give a great deal of insight into the physiological stability of a patient and yet it remains an undervalued diagnostic marker. This thesis highlights the need for a lab-on-chip device to quantify buffer capacity of whole blood samples by estimating the total titratable buffer concentration. Buffer capacity is quantified by titrating the buffer to its end point using monoprotic acids. More sophisticated ways include electrolytic titration, i.e. producing a proton flux using electrodes in a controlled environment. This thesis looks at a novel approach to electrolytic (coulometric) titration by inhibiting the production of OH ions during electrolysis and titrating the sample due to the proton flux from the anode. By definition, is the amount of acid or base added to change the pH of 1 litre of buffer by 1 pH unit. The carbonic acid bicarbonate buffer system is the most important buffer that maintains the body's pH within a stable range. To quantify this buffer's total buffering concentration, it is important to know and indicate its titration end point which signifies the total exhaustion of all buffering constituents. Colorimetric indicators have been used to indicate this end point which can be quantified through cameras or spectrophotometric techniques. Using this novel coulometric titrator and the colorimetric end point detector, this thesis presents a portable lab-on-chip prototype to spectrophotometrically quantify total titratable buffer concentration. Clinically, this device could benefit patients with sickle cell disease, nephritic disease and those admitted in accident and emergency wards. This research work is aimed at presenting a proof-of-concept for a device that can titrate nano-litre samples and be able to detect the end point of a titration in a controlled way.

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HINO, Rei, Tetsuya KUSUMI, Jae-Kyu YOO, and Yoshiaki SHIMIZU. "Job Shop Scheduling Focusing on Role of Buffer." The Japan Society of Mechanical Engineers, 2006. http://hdl.handle.net/2237/9231.

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Phadungchewit, Yuwaree. "The role of pH and soil buffer capacity in heavy metal retention in clay soils /." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74563.

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The concept of soil buffer capacity was used in this study to investigate the capacity of soil to attenuate heavy metals when acid is involved in the soil system. The buffer capacity of soil in this study was found to depend mainly on carbonate content and cation exchange capacity (C.E.C.) of soils. The magnitude of buffer capacity followed the order: illite $>$ montmorillonite $>$ natural clay soil $ gg$ kaolinite.
The study of heavy metal retention in soils was performed both by soil suspension test and soil column test. The results showed that as soils received increasing amounts of acid, high amounts of heavy metals (particularly Pb and Cu) could still be retained if the soils had a high enough buffer capacity to resist a change in pH such that it will not drop to $ Cu > Zn > Cd.$ The order changed to $Pb > Cd > Zn > Cu$ when soils were at low soil solution pH. Relative mobility of heavy metals found from the soil column test followed the order $Pb < Cu < Zn leq Cd.$
The relation of soil buffer capacity and heavy metal retention and movement in the clay soils found from this study revealed that the soil buffer capacity was a parameter that can be used in the prediction and prevention of heavy metal migration in soil. The soil buffer capacity is recommended as a parameter that should be included in the determination of soil properties particularly for the purpose of land application and disposal of wastes with leachates that could contain heavy metals. (Abstract shortened by UMI.)

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Louw, Louis. "Protective capacity and time buffer design in theory of constraints controlled discrete flow production systems." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/49782.

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Thesis (PhD)--Stellenbosch University, 2005.
ENGLISH ABSTRACT: To maximise the throughput of a production system the capacity constrained resource needs to be protected from variation and uncertainty. In the Theory of Constraints philosophy such protection is provided by means of time buffers and protective capacity. Time buffers are protective time that is allowed in the production schedule to buffer against disruptions, whereas protective capacity is defined as a given amount of extra capacity at non-constraints above the system constraint's capacity. In this research an analytical procedure was developed to more accurately determine the required time buffer lengths. This procedure uses an open queuing network modelling approach where workstations are modelled as GIIG/m queues. A simulation experiment was performed to evaluate the time buffer estimation procedure on the operations of an actual fifteen station flow shop. The results from the study suggest that the analytical procedure is sufficiently accurate to provide an initial quick estimate of the needed time buffer lengths at the design stage of the line. This dissertation also investigated the effect of protective capacity levels at a secondary constraint resource as well as at the other non-constraint resources on the mean flow time, the bottleneck probability of the primary constraint resource, as well as the output of flow production systems using simulation models and ANOV A. Two different types of flow production systems were investigated: (1) a flow shop with a fixed number of stations and unlimited queue or buffer space between stations, and (2) an assembly line where a total work content is distributed among stations in a certain fashion and the number of stations are not fixed. The experimental studies show that flow shop performance in the form of flow time and line output is not that much influenced by low protective capacity levels at the secondary constraint resource. Low protective capacity levels at a single station however can significantly reduce the bottleneck probability for the primary constraint resource when it is located before and relatively close or near to the primary constraint in the process flow, or after but relatively far from the primary constraint. An after-far secondary constraint location also causes slightly longer job flow times, and should therefore be avoided if possible. The research further shows that quite high protective capacity levels at the nonconstraint resources are needed to ensure a more stable and therefore manageable primary constraint. However low average levels of protective capacity at non-constraint resources are sufficient to ensure that the maximum designed output level as determined by the utilisation of the primary constraint resource is obtained. The results for the assembly line experiment showed that an unbalanced line configuration where less work is assigned to the non-constraint stations than to the primary constraint station (but nonconstraint stations have an equal work content) can lead to significant reductions in the mean flow time while maintaining the same line output, without resulting in too many additional stations. Low protective capacity levels in the range of 2% to 5% are sufficient to cause substantial improvements in flow time without resulting in too many additional stations in the line.
AFRIKAANSE OPSOMMING: Om die finale uitset van 'n produksiestelsel te maksimeer is dit noodsaaklik dat die bottelnek beskerm word teen fluktuasies en onderbrekings. In die "Theory of Constraints" filosofie word van twee soorte beskermingsmeganismes gebruik gemaak: tydbuffers en beskermende kapasiteit. Tydbuffers is beskermende tyd wat in die produksieskedule gevoeg word om sodoende die bottelnek teen onderbrekings te beskerm, terwyl beskermende kapasiteit ekstra produksiekapasiteit relatief tot die bottelnek se kapasiteit is wat by nie-bottelnekke gevoeg word. In hierdie navorsing IS 'n analitiese prosedure ontwikkel om meer akkurate berekenings van tydbuffergroottes te verkry in produksiestelsels wat volgens 'n "Theory of Constraints" filosofie bestuur word. Die prosedure maak gebruik van oop toustaan netwerk modellering waar werkstasies gemodelleer word as GIIG/m toue. Die analitiese prosedure is ge-evalueer met 'n simulasie eksperiment op 'n werklike vyftien stasie vloeiwinkel. Die resultate dui aan dat die analitiese prosedure akkuraat genoeg is om vinnig aanvanklike beramings vir die benodigde tydbuffergroottes tydens die ontwerpsfase van die produksiestelsel te verskaf. Verder is ook ondersoek ingestel na die effek van beskermende kapasiteitsvlakke by die sekondêre bottelnek asook die ander nie-bottelnekke op die gemiddelde deurvloeityd, die totale uitset, asook die bottelnek waarskynlikheid vir die primêre bottelnek in vloei produksiestelsels deur gebruik te maak van simulasie modelle en ANOVA. Twee verskillende tipes vloei produksiestelsels is ondersoek: (1) 'n vloeiwinkel met 'n vaste aantal stasies en 'n onbeperkte buffer spasie tussen stasies, en (2) 'n monteerlyn waar 'n totale werksinhoud op 'n bepaalde wyse onder stasies verdeel moet word en die aantal stasies nie vas is nie. Die eksperimentele studies dui aan dat die deurvloeitye en totale uitset van 'n vloeiwinkel me noemenswaardig beïnvloed word deur lae beskermende kapasiteitsvlakke by die sekondêre bottelnek nie. Hierdie maatstawwe word meer beïnvloed word deur die gemiddelde beskermende kapasiteitsvlakke by al die nie-bottelnekke. Lae beskermende kapasiteit by 'n enkele werkstasie kan egter die bottelnek waarskynlikheid vir die primêre bottelnek aansienlik verlaag indien dit voor en relatief na aan die primêre bottelnek in die prosesvloei geleë is, of na, maar relatief ver, vanaf die primêre bottelnek. 'n Sekondêre bottelnek ligging na maar relatief ver vanaf die primêre bottelnek in die prosesvloei veroorsaak ook langer deurvloeitye, en moet dus vermy word. Verder dui die navorsing aan dat redelike hoë gemiddelde beskermende kapasiteit by nie-bottelnekke benodig word om 'n meer stabiele primêre bottelnek te verseker. In vloeiwinkels met lae vlakke van variasie en onderbrekings is egter lae gemiddelde vlakke van beskermende kapasiteit by nie-bottelnekke voldoende om te verseker dat die maksimum ontwerpte uitset soos bepaal deur die benutting van die primêre bottelnek behaal word. Die resultate vir die monteerlyn eksperiment dui aan dat 'n ongebalanseerde lynkonfigurasie waar minder werk aan die nie-bottelnek stasies as aan die primêre bottelnek stasie toegeken word (maar niebottelnek stasies het 'n gelyke werksinhoud), aansienlike verlagings in deurvloeityd teweeg kan bring terwyl dieselfde lyn uitset behou word. Dit is moontlik sonder te veel addisionele stasies in die lyn. Die eksperimentele resultate dui aan dat lae beskermende kapasiteitsvlakke van tussen 2% tot 5% voldoende is om beduidende verlagings in deurvloeityd teweeg te bring sonder te veel addisionele stasies.

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8

Rose, S. J. "The role of milk buffer capacity in the determination of bowel flora populations in infants." Thesis, University of Aberdeen, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381053.

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Hand rearing infants has always carried a greater mortality rate than breast feeding despite the development of safe preserving techniques for milk: stool bacterial culture revealed two distinctive florae, fermentatitive, with a predominance of lactobacilli in breast fed infants and putrefactive, with a predominance of coliform bacteria in artificially fed infants. This difference was suggested to be the basis for the difference in the incidence of gastroenteritis. An artificial milk inducing a breast milk stool flora would, thus, reduce the incidence of gastroenteritis in artificially fed infants. The buffer capacity of milk was claimed to determine stool buffer capacity, which then encouraged growth of specific bacterial populations. However, an artificial milk with identical buffer capacity to breast milk returned disparate bacterial results. The hypothesis examined in this study was that buffer capacity of infant milk modifies stool flora. Breast milk and three artificial milks were studied. The artificial milks differed either in buffer capacity or in composition of major dietary components. Biochemical analyses were performed on milk, stool and stool water obtained by ultracentrifugation. Buffer capacity in milk was related to protein content. No biochemical differences were detected in stool water from each group, however whole stool buffer capacity was considerably greater in the group fed high buffer capacity milk than in the other three groups. No difference was detected in total bacterial numbers cultured, the types of organisms, nor individual species numbers. Thus the presently available highly modified artificial milks may determine stool buffer capacity, but do not induce a gut flora distinct from breast feeding. Thus the continuing increased incidence of gastroenteritis in artificially fed infants can no longer be related to differences.

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Lin, Chung-Ho. "Bioremediation capacity of five forage grasses for Atrazine, Balance (Isoxaflutole) and nutrient removal /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3052192.

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Crawford, James. "A model of pH and redox buffer depletion in waste landfills." Doctoral thesis, Stockholm : Tekniska högsk, 1999. http://www.lib.kth.se/abs99/craw0510.pdf.

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樋野, 励., Rei HINO, 哲也楠見, Tetsuya KUSUMI, 在圭柳, Jae-Kyu YOO, 良明清水, and Yoshiaki SHIMIZU. "バッファを考慮にいれたジョブショップスケジューリング." 日本機械学会, 2005. http://hdl.handle.net/2237/9232.

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Enstipp, Manfred. "Diving energetics and fine scale foraging behaviour of avian divers and their capacity to buffer environmental change." Université Louis Pasteur (Strasbourg) (1971-2008), 2005. https://publication-theses.unistra.fr/public/theses_doctorat/2005/ENSTIPP_Manfred_2005.pdf.

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Les oiseaux marins sont présents sur toutes les mers du globe et dans des zones climatiques extrêmement différentes, allant des tropiques jusqu’aux régions polaires. Un grand nombre d’espèces vivent en haute mer et capturent leurs proies sous l’eau. L’élément liquide possède un énorme pouvoir de refroidissement et génère de fortes contraintes thermiques sur ces homéothermes. Ces contraintes ont certainement influencé les modes de colonisation des écosystèmes aquatiques par les oiseaux marins. Dans ces milieux hostiles, les oiseaux assurent leur survie par le biais de deux stratégies (non exclusives). (1) Augmentation de l’isolation périphérique afin de minimiser les pertes de chaleur au contact de l’eau; (2) exploitation de zones riches en nourriture afin de maximiser leurs gains d’énergie au cours de la recherche alimentaire. La combinaison de ces deux stratégies permet l’optimisation de l’efficacité énergétique au cours de la recherche alimentaire. Afin de comprendre comment les oiseaux marins se sont adaptés au milieu aquatique au cours de leur trajectoire évolutive et de définir leur rôle au sein des écosystèmes actuels, il est donc de toute première importance d’étudier les mécanismes qui régissent leurs dépenses énergétiques ainsi que leurs gains en énergie au cours de la recherche alimentaire. Au cours des deux dernières décennies, les avancées technologiques ont permis la réalisation d’un grand nombre d’études concernant le comportement alimentaire des oiseaux marins ainsi que leurs besoins énergétiques. Ces deux volets ont pourtant rarement été considérés conjointement et certains aspects fondamentaux restent négligés. Par exemple, l’effet de la pression sur l’isolation thermique et sur la flottabilité des oiseaux plongeurs, ainsi que ses conséquences sur les coûts énergétiques de la plongée n’ont pas encore été mesurés directement. En outre, le comportement prédateur des oiseaux plongeurs a principalement été déduit de mesures effectuées par des capteurs embarqués. Des observations directes et détaillées des techniques de pêche ainsi que des études de l’impact de divers facteurs biotiques et abiotiques sur ces stratégies restent extrêmement rares. Le comportement des oiseaux marins est d’autre part principalement étudié à l’échelle de l’individu. Il est cependant nécessaire et urgent de prédire les réactions des communautés d’oiseaux marins aux changements environnementaux, qu’ils soient d’origine naturelle ou anthropique. Ces stress environnementaux provoquent en effet à l’heure actuelle des changements de régime et de structure variés au sein des écosystèmes marins. Des informations détaillées concernant les processus d’acquisition et de dépense d’énergie chez différentes espèces d’oiseaux marins constituent donc la base de modèles bio-énergétiques qui permettront une approche fonctionnelle prédictive du rôle des oiseaux marins au faîte des réseaux trophiques aquatiques. La collecte de données écophysiologiques ainsi que leur synthèse dans le cadre d’exercices de modélisation, nous permettra donc de juger de la capacité d’adaptation des prédateurs marins aux changements environnementaux (tels qu’une baisse de la disponibilité des proies). Mes travaux de thèse, qui traitent de l’écophysiologie de la recherche alimentaire chez les oiseaux plongeurs ont principalement concerné les cormorans. Des études récentes ont suggéré que les coûts de la recherche alimentaire sont particulièrement élevés chez ces oiseaux, mais que ceux-ci adaptent leur comportement prédateur afin de minimiser la durée totale de la recherche alimentaire (par le biais d’une augmentation de l’efficacité prédatrice). Cette stratégie nécessite l’exploitation de ressources alimentaires particulièrement profitables (forte densité des proies et/ou grande valeur calorifique). On peut donc prédire que les cormorans seront particulièrement sensibles aux contraintes environnementales affectant les conditions de la recherche alimentaire et/ou la disponibilité des proies. Ce sont donc d’excellents modèles d’étude de l’impact de ce type de changements sur les prédateurs marins. Mes travaux de thèse s’articulent en sept chapitres. A l’issue d’une introduction générale (chapitre 1), je présente deux études de la dépense énergétique associée à la recherche alimentaire chez les oiseaux plongeurs (chapitres 2 et 3). Plus spécifiquement, j’ai étudié l’influence de la température de l’eau, de la profondeur des plongées ainsi que du statut nutritif des oiseaux sur les coûts énergétiques de la plongée chez les cormorans huppés (Phalacrocorax aristotelis) et les cormorans à aigrettes (Phalacrocorax auritus). Je détaille par la suite les comportements associés à la recherche alimentaire chez les oiseaux plongeurs (chapitres 4 et 5). Il s’agit d’une analyse détaillée des techniques de capture des poissons chez les cormorans à aigrettes et les grands cormorans (Phalacrocorax carbo) en fonction de divers paramètres biotiques et abiotiques. Enfin, je combine certains de ces résultats avec des données tirées de la littérature afin de développer un modèle bio-énergétique (chapitre 6). Ce modèle, élargi à quatre espèces d’oiseaux marins de la Mer du Nord, m’a permis de calculer leurs besoins alimentaires théoriques pendant la phase d’élevage des poussins. Il m’a également permis de tester la capacité d’adaptation de ces différentes espèces à une baisse de la disponibilité de leurs proies principales. Ces diverses études débouchent sur des conclusions et perspectives qui sont présentées dans le chapitre 7
Avian divers are confronted with a number of physiological challenges when foraging in cold water, especially at depth. Diving is believed to be particularly costly in cormorants (Phalacrocoracidae) because of their poor insulation and less efficient foot-propulsion. I used open-circuit respirometry to study the energetic requirements of two Phalacrocorax species, the European shag (P. Aristotelis) and the double-crested cormorant (P. Auritus) when diving in a shallow (1 m) and deep (10 m) dive tank. I also investigated the modifying effects of water temperature and feeding status on dive costs. My results indicate that the energetic costs during shallow diving in European shags and double-crested cormorants are comparable to other foot-propelled divers. Metabolic rate was significantly increased when diving to greater depth and at lower water temperatures, while feeding before diving increased metabolic rate, albeit not significantly. The strong effects of depth and water temperature on cormorant diving metabolic rate are most likely a consequence of their partially wettable plumage and their reduced plumage air volume, which makes them prone to heat loss and, hence, increases thermoregulatory costs. The energetic requirements of animals have to be satisfied by intake of resources from the environment. Hence, the quest for food is a central aspect of animal behavior. Although the study of seabird foraging behaviour has greatly profited from recent technological developments, we still know little about predator-prey interactions on a fine scale. I used an underwater video array to investigate the prey-capture behaviour of double-crested cormorants foraging on live rainbow trout (Oncorhynchus mykiss). I tested the effects of a variety of factors on the underwater foraging behaviour of cormorants and established a functional link between prey density and cormorant prey capture rate. Prey density and behaviour both significantly affected predator performance. At prey densities below 2-3 g fish m-3 birds increased their search time during a trial drastically, while prey-encounter rate was greatly decreased. When cormorants attacked shoaling rather than solitary trout, their capture success was significantly reduced, while pursuit duration was significantly increased. Seabird energetics and behaviour are typically studied on the individual or species level. However, if we want to understand how seabirds react to environmental changes, we have to consider entire communities. In the western North Sea, a large seabird assemblage critically depends on a single fish species, the lesser sandeel (Ammodytes marinus), which is also exploited by an industrial fishery. I developed an algorithm to test for the capacity of four seabird species during chick-rearing in Scotland to buffer a potential decline in sandeel abundance by increasing their foraging effort in various ways. My results show that under the conditions currently operating in this region shags and guillemots (Uria aalge) may have sufficient time and energy to allow them to increase their foraging effort considerably, while Kittiwakes (Rissa tridactyla) and gannets (Morus bassanus) appear more constrained by time and energy respectively. My study suggests that during chick-rearing gannets are working at the highest metabolic level of all species considered and hence, have the least physiological capacity to increase foraging effort. This indicates that gannets could potentially be very sensitive to a reduction in sandeel abundance. My thesis emphasises the importance of taking into account seabird energetics as well as fine scale behavioural requirements, when trying to develop management schemes for fisheries that will allow the coexistence of both seabirds and human fishery in a sustainable way

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Okada, Hiraku, Takaya Yamazato, Masaaki Katayama, and Akira Ogawa. "Queueing Analysis of CDMA Unslotted ALOHA Systems with Finite Buffers." IEICE, 1998. http://hdl.handle.net/2237/7206.

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Sandrini, Luiz Guilherme. "O trade-off entre os buffers de capacidade de produção e de estoque." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3136/tde-18112009-100431/.

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Este trabalho propõe um método de análise do trade-off entre o buffer de capacidade de produção e o buffer de estoque, necessários para garantir o bom desempenho de um sistema sujeito a variações de demanda. A análise envolve a definição de um sistema de produção e a construção de um modelo de simulação. A simulação é realizada num sistema formado por uma única estação de trabalho, com mix de 10 produtos, controlados por um sistema kanban, que é considerado por muitos autores inadequado para operar em ambientes cuja demanda não é estável. Os resultados mostram que o buffer de capacidade proporciona vantagens operacionais e de custo ainda que sujeito a maiores níveis de variação de demanda.
This research proposes a method to analyze the trade-off between the production capacity buffer and the inventory buffer, required to guarantee high performance levels in a system with demand variation. The analysis involves a production system delineation and the development of a simulation model. The system simulated is a single-stage production system, with mix of ten products, controlled by a kanban system, which is classified by several authors as not recommended in environments with unstable demand. The results indicate that the production capacity buffer enables operational and cost advantages, even if the production system is under higher demand variation.

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Apelian, Vahe H. "Effects of diffusion layer pH and buffer capacity on the intrinsic dissolution of pharmaceutical acids and their salts /." Ann Arbor,Mich. : University Microfilms International, 1992. http://www.gbv.de/dms/bs/toc/016106547.pdf.

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16

Hu, Junqi. "Estimation of Runway Throughput with Reduced Wake Vortex Separation, Technical Buffer and Runway Occupancy Time Considerations." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/85047.

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This thesis evaluates the potential recovery of the runway throughput under Wake Turbulence Re-categorization (RECAT) Phase II and Time-based Separation (TBS) with a Runway Occupancy Time (ROT) constraint comparing with RECAT Phase I. This research uses aircraft performance parameters (runway occupancy time, approach speed, etc.) from the Airport Surface Detection Equipment, Model X (ASDE-X) data set. The analysis uses a modified version of the Quick Response Runway Capacity Model (RUNSIM). The main contributions of the study are: 1) identifying the technical buffer between in-trail arrivals and regenerate them in RUNSIM; 2) estimate the percentage of the arrival pairs that have wake mitigation separation times in excess of ROT; 3) developed an additional in-trail arrival separation rule based on ROT; 4) measure the risk of potential go-arounds with and without the additional 95 ROT separation rules. 5) generate a sample equivalent time-based RECAT II. The study results show that the distributions of technical buffers have significant differences for different in-trail groups and strong connectivity to airport elevations. This is critical to estimate runway capacities and safety issues especially when advanced wake mitigation separation rules are applied. Also, with decreasing of wake separations, ROT will become a limiting factor in runway throughput in the future. This study shows that by considering a 95 percentile ROT constrain, one single runway can still obtain 4 or 5 more arrivals per hour under RECAT II but keep the same level of potential go-arounds compared with current operation rules (RECAT I). TBS rules seem to benefit more under strong wind conditions compared to RECAT I, and RECAT II. TBS rules need to be tailored to every airport.
Master of Science

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FERNANDEZ, NICOLE SUCLLA. "MULTI-PROJECT MANAGEMENT THROUGH THE CRITICAL CHAIN METHODOLOGY: EFFECTS OF CAPACITY BUFFER AND OF THE CRITERIA TO PRIORITIZE ACTIVITIES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=13425@1.

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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
Este trabalho trata da gestão de múltiplos projetos mediante a metodologia da Cadeia Crítica e Gestão de Buffers (Critical Chain and Buffer Management CC/BM). Concentra-se na análise e entendimento dos efeitos que as abordagens mais usuais para dimensionamento dos buffers de capacidade (Capacity Buffers BC) e definição dos critérios de priorização de atividades têm sobre os objetivos da empresa e dos próprios projetos. O estudo baseia-se num problema-exemplo apresentado por Pritsker B. et al. (1969.). Para facilitar a análise, esse exemplo se caracteriza por uma estrutura simples, mas que apresenta interdependências relevantes para o estudo dos conflitos de compartilhamento de recursos entre projetos. Analisam-se as abordagens de todos juntos, projetos sucessivos e do recurso gargalo, propostas por Newbold (1998) para planejamento conjunto de projetos simultâneos. Tais abordagens são implementadas através das ferramentas de programação de projetos Prochain & Pipeline. A partir dos programas (schedules) resultantes, analisam-se as características e deficiências de cada abordagem. Ademais, tais resultados permitem identificar certas condições e efeitos conflitantes no dimensionamento dos BC e no critério de priorização de atividades utilizado nas implementações típicas da metodologia. Tais observações criaram a necessidade de complementar a análise mediante a simulação probabilística da etapa de execução dos projetos. A pesquisa explica a diferença entre os efeitos dos critérios de priorização dinâmica e estática, esclarece a interação entre os buffers de capacidade e buffers de projeto. Ela ainda analisa os efeitos de dimensionar os BCs, para todos os projetos, como uma mesma porcentagem da carga do recurso e ilustra os trade-offs entre estabilidade do sistema e o makespan dos projetos.
This research addresses the management of multiple simultaneous projects through the application of the Critical Chain and Buffers Management (CC/BM) methodology. The focus is on the analysis and interpretation of the effects that the more usual approaches for Capacity Buffers (CB) sizing and criteria to prioritize activities have on the companys and on the projects own objectives. The study is based on the problem-example presented by Pritsker B. et al. (1969.) For simplifying the analysis, this example is characterized by a simple structure that, nevertheless, presents interdependences significant for the study of conflicts created by sharing resources between simultaneous projects. The approaches for simultaneous projects management, presented by Newbold (1998) are analyzed, namely: the all together, the successive projects and the strategic resource. Their implementations are made using the Prochain & Pipeline multi-project management tools. From the resulting schedules, the characteristics and deficiencies of each approach are analyzed. Furthermore, these results allow the identification of certain conditions and conflicting effects in the BC sizing and in the criteria used to prioritize activities in the typical methodology implementations. Such observations led to the necessity of complementing the analysis with the aid of probabilistic simulation of the projects execution stage. The research explains the differences between the effects of dynamic and static prioritization, elucidates the interaction between the capacity and the project buffers. It also examines the effects of using the same percentage of the resource load for sizing the BCs for all the projects, and illustrates the trade-offs between the system stability and the projects makespan.

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Okada, Hiraku, Takaya Yamazato, Masaaki Katayama, and Akira Ogawa. "CDMA Slotted ALOHA System with Finite Buffers." IEICE, 1998. http://hdl.handle.net/2237/7205.

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Ghaffari, Mahdi. "The impact of multitasking on critical chain portfolios." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/the-impact-of-multitasking-on-critical-chain-portfolios(e5ecf7a2-20ae-44db-8fea-2865cc5970b1).html.

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Critical Chain Project Management (CCPM) is a project scheduling technique which has been developed to overcome some of the deficiencies of traditional methods and where, in a single project environment, the critical chain is the longest chain of activities in a project network, taking into account both activity precedence and resource dependencies. In multi-project environments, the constraint is the resource which impedes projects' earlier completion. CCPM relies on buffers to protect the critical chain and monitor/control the project. The literature review conducted by this study reveals that the research on CCPM principles in multi-project environments is still extremely scarce. The review also suggests that outright elimination of multitasking (i.e. switching back and forth among two or more concurrent tasks) by imposing a relay race mentality (i.e. starting a task as soon as it becomes available and finishing it as soon as possible), as one of the main features of CCPM, might worsen the resource constraints of CCPM portfolios and cause creation of over-protective buffers. It further implies that there is also a good level of multitasking that can benefit such environments by improving resource availability and requiring shorter protective buffers. This research aims to bridge the gap by investigating the impact of level of multitasking on resource availability issues and project and feeding buffer sizing in CCPM portfolios with different resource capacities. This is pursued through adopting a deductive approach and developing five research hypotheses, considering ten different levels of resource capacity, testing the hypotheses by conducting Monte Carlo simulations of randomly generated project data and comparing the results with deterministic duration values of the same portfolios with 30%, 40% and 50% feeding and project buffer sizes. In total, ten portfolios with similar size, variability and complexity levels, each containing four projects, were simulated. It was concluded that: firstly, some limited levels of multitasking, determined in relation to the level of resource capacity, can be beneficial to time performance of CCPM portfolios; secondly, shorter buffer sizes can be accounted for by abolishing the ban on multitasking while maintaining a lower rate of resource capacity; finally, the element of relay race work ethic that completely bans multitasking should not be implemented as it proved to be counterproductive in terms of resource availability. Seven recommendations and a buffer sizing framework are provided as complementary guidelines to practitioners' own experience, knowledge and judgment, in addition to an explanation of theoretical and practical contributions and suggestions for future research.

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Tohidi, Maryam. "Titrimetric monitoring of chemical equilibrium and pH dynamics in a pilot-scale water resource recovery facility using PHREEQC and buffer capacity modelling." Master's thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/66708.

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L’augmentation considérable de l’eutrophisation des eaux de surface dans les dernières décennies a mené à la création de stations de récupération des ressources de l’eau (StaRRE) de plus en plus instrumentées pouvant procéder à l’élimination des nutriments. Pour assurer l’efficacité des procédés de récupération, plusieurs paramètres de qualité des eaux doivent être surveillés. Des méthodes en ligne et hors-ligne existent pour réaliser cette surveillance. Cependant, certains paramètres sont difficilement mesurés en ligne, alors des analyses en laboratoire sont toujours de mise. La titrimétrie est une méthode hors-ligne permettant la surveillance de la qualité des eaux en laboratoire. Un appareil Titrino a été installé afin de procéder à l’analyse titrimétrique des eaux usées de l’usine pilEAUte, une StaRRE de traitement expérimentale de 12 m3 située sur le campus de l’Université Laval. L’eau usée de cette station provient d’une résidence étudiante du campus et de ses environs. L’eau pompée vers la station est stockée dans un bassin de 5 m3 avant d’être acheminée à un décanteur primaire. L’effluent du décanteur est alors envoyé vers deux chaînes de traitement biologique composées de cinq bioréacteurs chacune. Enfin, l’eau est acheminée vers deux décanteurs secondaires. Dans le cadre de ce projet, des campagnes de mesure ont été réalisées afin de comparer les données provenant de capteurs en ligne avec l’information extraite d’expériences de titrimétrie pour la mesure de la qualité des eaux usées de la station. Ces campagnes de mesure ont été réalisées en lien avec de projets menés avec des partenaires industriels. L’objectif de cette étude est d’évaluer l’efficacité des analyses de titrimétrie pour la mesure de la qualité de l’eau à l’affluent et à l’effluent d’une StaRRE. Les données extraites de la titrimétrie sont analysées de deux façons différentes: la modélisation de la capacité tampon de l’eau et la modélisation de l’équilibre chimique via le logiciel PHREEQC. Ces méthodes ont été mises en place, puis comparées sur la base de leur efficacité pour mesurer la concentration de certaines substances tampon présentes dans les eaux usées. Pour améliorer les estimations des modèles, des améliorations au protocole d’utilisation du Titrino ont été développées. Il a été déterminé que l’utilisation d’une couverture d’azote gazeux et le stripage du CO2 dissout dans les échantillons sont nécessaires à la réalisation de titrations fiables, et sont donc aussi nécessaires à la mesure de substances tampon autre que l’alcalinité, soit l’ammoniaque et les acides gras volatils (AGV). Afin de valider les résultats obtenus à l’aide du modèle de capacité tampon et afin d’obtenir une description complète de l’équilibre chimique des solutions analysées, un modèle de simulation de la procédure de titration a été développé avec le logiciel PHREEQC et l’interface PHREEQXCEL. Cet environnement de simulation a été supplémenté du solveur OpenSolver, un complément Excel à licence libre capable de réaliser les estimations de paramètres requises pour estimer la concentration de chaque espèce chimique présente dans les échantillons. De plus, la base de données de réactions chimiques de PHREEQC a été modifiée afin d’inclure toute l’information chimique nécessaire à la modélisation des spéciations se produisant dans les eaux usées. Après avoir proposé ces améliorations et avoir comparé les résultats des analyses de titration à des analyses chimiques conventionnelles, il a été déterminé que la titrimétrie est une alternative fiable pour la surveillance de la performance des procédés de récupération des nutriments des eaux usées.
The considerable rise of eutrophication in water bodies has led to highly instrumented water resource recovery facilities (WRRFs) that can perform nutrient removal processes. To ensure the efficiency of these processes, several parameters that influence the performance of WRRFs need to be well thought out. The latter requires monitoring strategies composed of on-line and off-line methods. Lately, on-line measurements have contributed significantly to monitor and characterize the quality of water and wastewater. However, on-line measurements are not applicable or not implemented yet for some specific areas. For this, off-line laboratory methods are welcome alternatives. Titrimetry is one of the examples of a low-cost off-line method that allows characterizing aquatic streams. Concerning titrimetric monitoring of wastewater, a Titrino device was installed in the laboratory of the 12 m3 pilEAUte WRRF located at Université Laval. The wastewater feeding the plant is coming from a student residence building on campus. The water pumped to the station is feeding a storage tank with a volume of 5 m3 , from which it is then pumped to a primary clarifier. The influent stream is then split into two similar treatment lines, composed of several bioreactors. These two lanes are followed by two secondary settling tanks. In this work, sampling campaigns were performed to compare the sensor data and the off-line titrimetric measurements in a framework of research projects in which industrial partners are involved. The goal of this study was to investigate the efficiency of using titrimetry to analyze and characterize influent and effluent samples of a WRRF. Two data interpretation methods, buffer capacity and PHREEQC, were tested and their performances in estimating the concentration of the concerned buffers were evaluated. For better model estimation, first, some of the lab procedures were improved. It was found out that nitrogen blanketing and CO2 stripping are necessary to perform reliable titration, and thus, to measure other concerned buffers besides alkalinity, such as ammonia and volatile fatty acids (VFA). Moreover, to validate the results of the buffer capacity model and to have a complete description of the equilibrium reactions of the chemical system under study, a titration simulation model was successfully built in PHREEQC with the PHREEQXCEL interface. This titration lab simulation was extended with the OpenSolver, an open-source Excel add-in, which allows to reliably perform the parameter estimation needed to find the concentration of the different species in the sample. In addition, PHREEQC’s database was modified to include all the model components and their essential chemical information for the speciation calculations.After introducing the mentioned lab and modelling improvements, the reliability of the titrimetric measurements for monitoring the performance of nutrient removal was enhanced.

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Menezes, Madalena Lima. "Digestibilidade aparente dos nutrientes e metabolismo energético de equídeos submetidos à dietas com diferentes fontes energéticas." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/74/74131/tde-14062017-142854/.

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O objetivo do presente estudo foi avaliar a inclusão de duas fontes energéticas (alto açúcar e alto amido (AA), alta fibra e alto óleo (FO)) na dieta de asininos e equinos, através de ensaios de digestibilidade aparente dos nutrientes, características físico-químicas das fezes e parâmetros sanguíneos, vinculados ao metabolismo energético dos equídeos. Foram utilizados 20 equídeos, dez equinos da raça Quarto de Milha e dez asininos da raça Pêga, distribuídos no delineamento alternado do tipo Cross-Over, com duas fontes energéticas e duas espécies. As dietas experimentais foram compostas de 50% da energia proveniente do Feno Tifton 85 (Cynodon spp.) e 50% proveniente do concentrado, formulados a base amido e açúcar, e fibra e óleo. Foi observado efeito de dieta (p<0,05) sobre os coeficientes de digestibilidade do extrato etéreo e fibra em detergente ácido, capacidade tamponante a pH 5 e pH 6 (maiores valores para dieta Fibra óleo) e sobre as concentrações sanguíneas de glicose (maiores valores para dietas açúcar amido. Observou-se efeito de espécie (p<0,05) sobre o coeficiente de digestibilidade aparente de proteína bruta, sobre a capacidades tamponante à pH 5 e sobre as concentrações sanguíneas de glicose (maiores níveis glicêmicos observados para equinos). Houve efeito de tempo de coleta (p<0,05) sobre as concentrações plasmáticas de acetato. Para as concentrações sanguíneas e fecais de ácidos graxos de cadeia curta totais, propionato não houve efeito (p>0,05) de dieta ou de espécie. Dietas composta por predominância de volumoso acrescido de concentrado a base de amido e açúcar e fibra e óleo são igualmente aproveitadas pelos equídeos com destaque para a dieta fibra e óleo no aproveitamento de lipídios, sem causar efeito deletério sobre as características físico-químicas, o pH e a capacidade tamponante das fezes. Asininos são mais eficientes no tamponamento de ácidos intestinais. Os asininos apresentam maiores concentrações sanguíneas de AGCC totais e acetato nas fezes, porém não no sangue nas dietas a base de FO. A glicemia e insulinêmica de asininos é menor do que a de equinos. Dietas com açúcar e amido apresentam maiores níveis glicêmicos e insulinêmicos para ambas as espécies. Dietas a base de fibra e óleo se mostraram promissoras para ambas as espécies, em especial para os asininos.
The aim of the present study was to evaluate the inclusion of two energy sources (high sugar and high starch (AA), high fiber and high oil (FO)) in the diet of asinines and equines, through the trials of apparent digestibility of nutrients, physico-chemical characteristics of feaces and blood parameters, related to equine energy metabolism. Twenty equids, 10 Quarter Horse horses and 10 Pêga breed donkeys were used, distributed in an alternate Cross-Over type design, with two energetic sources and two species. Experimental diets were composed of 50% of the energy from the Tifton 85 (Cynodon spp.) and 50% from the concentrate, based on starch and sugar, and fiber and oil. It was observed effect of diet (p<0.05) on the digestibility coefficients of ether extract and acid detergent fiber, buffer capacity at pH 5 and pH 6 (higher values for fiber and oil diet) and on blood concentrations of glucose (higher values for sugar and starch diet). It was observed effect of specie (p<0.05) on the digestibility coefficient of crude protein, on buffering capacities at pH 5 and on blood concentrations of glucose (higher glycemic levels observed for equines). There was effect of the collection time (p<0.05) on the plasmatic concentrations of acetate. For blood and fecal concentrations of short chain fatty acids, there was no effect for propionate (p<0.05) of diet or specie. Diets composed by predominance of forage plus concentrate based on starch and sugar, and fiber and oil are equally used by the equids with emphasis of the fiber and oil diet in the use of lipids, without causing deleterious effect on the physico-chemical characteristics, pH and buffer capacity of feaces. Donkeys are more effective in buffering intestinal acids and also have higher blood concentrations of total SCFA and acetate in faeces, but not in blood in FO-based diets.

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Vellambi, Badri Narayanan. "Applications of graph-based codes in networks: analysis of capacity and design of improved algorithms." Diss., Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/37091.

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The conception of turbo codes by Berrou et al. has created a renewed interest in modern graph-based codes. Several encouraging results that have come to light since then have fortified the role these codes shall play as potential solutions for present and future communication problems. This work focuses on both practical and theoretical aspects of graph-based codes. The thesis can be broadly categorized into three parts. The first part of the thesis focuses on the design of practical graph-based codes of short lengths. While both low-density parity-check codes and rateless codes have been shown to be asymptotically optimal under the message-passing (MP) decoder, the performance of short-length codes from these families under MP decoding is starkly sub-optimal. This work first addresses the structural characterization of stopping sets to understand this sub-optimality. Using this characterization, a novel improved decoder that offers several orders of magnitude improvement in bit-error rates is introduced. Next, a novel scheme for the design of a good rate-compatible family of punctured codes is proposed. The second part of the thesis aims at establishing these codes as a good tool to develop reliable, energy-efficient and low-latency data dissemination schemes in networks. The problems of broadcasting in wireless multihop networks and that of unicast in delay-tolerant networks are investigated. In both cases, rateless coding is seen to offer an elegant means of achieving the goals of the chosen communication protocols. It was noticed that the ratelessness and the randomness in encoding process make this scheme specifically suited to such network applications. The final part of the thesis investigates an application of a specific class of codes called network codes to finite-buffer wired networks. This part of the work aims at establishing a framework for the theoretical study and understanding of finite-buffer networks. The proposed Markov chain-based method extends existing results to develop an iterative Markov chain-based technique for general acyclic wired networks. The framework not only estimates the capacity of such networks, but also provides a means to monitor network traffic and packet drop rates on various links of the network.

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Hedvall, Lisa. "Reducing and absorbing variations in a manufacturing context : A capacity management perspective." Licentiate thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Logistik och verksamhetsledning, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-43666.

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Variations can have substantially negative effects on performance and it is therefore important to investigate how the variations can be reduced or absorbed in an appropriate way for competitiveness. Manufacturing companies are daily exposed to variations and operations managers need to take capacity management decisions with this in mind to secure the delivery capability. The current body of knowledge mainly focus on techniques for root cause analysis for reducing variations, especially in the manufacturing processes, neglecting the fact that both internally and externally generated variations are more or less possible to affect. Buffers are traditionally associated with waste and unfavourable performance, while the right buffers can be of strategic importance. The purpose of this research is therefore to increase the understanding of causes for variations, actions to reduce variations and how buffers can be used to mitigate negative effects of variations related to capacity management in a manufacturing context. Three research studies have been conducted, including four appended papers, to fulfil the purpose. These studies encompassed different combinations of traditional literature reviews, conceptual research with logical reasoning and case study research. The findings demonstrate that working on mitigating negative effects of variations is a complex challenge and not just about choosing to reduce or absorb the variations. In general, it is concluded that the variation management and buffer management include several aspects to consider with implications for the capacity management. In addition, the results indicate that the decisions in manufacturing companies tend to be based on intuition and previous experience due to a lack of decision support. Furthermore, the participating companies perceive that several of their internal routines contribute to their prevailing variations. This research contributes to an awareness of causes for variations that are possible to affect, possible actions to reduce the variations and the purposes of different buffers to absorb variations. This is sought to facilitate a systematic way of working with reducing and absorbing variations, creating support in the variation management and the buffer management from a capacity management perspective.
Variationer kan medföra negativa effekter för en verksamhets prestation och det är därmed viktigt att utforska hur variationerna kan reduceras eller absorberas på lämpligt sätt för att verksamheten ska vara konkurrenskraftig. Tillverkande företag är dagligen exponerade för variationer och produktionschefer behöver beakta detta i kapacitetsadministrationen för att säkerställa leveransförmågan. Befintlig litteratur fokuserar främst på tekniker för att analysera grundorsaker inom tillverkningsprocesserna och ignorerar det faktum att både internt och externt genererade variationer är mer eller mindre påverkbara. Buffertar associeras traditionellt med oönskat slöseri fastän rätt buffertar kan vara av strategisk betydelse. Syftet med denna forskning är därmed att öka förståelsen för orsaker till variationer, åtgärder för att reducera variationer och hur buffertar kan tillämpas för att överkomma negativa effekter av variationer i relation till kapacitetsadministration inom en tillverkningskontext. Tre forskningsstudier, innefattande fyra publikationer, har genomförts för att uppfylla syftet. Dessa studier består av en kombination av traditionella litteraturstudier, konceptuell forskning med logiska resonemang och fallstudier i tillverkande företag. Resultaten visar att arbetet med att hantera negativa effekter av variationer är en komplex utmaning som stäcker sig bortom valet av att reducera eller absorbera variationerna. Generellt dras slutsatsen att det är flertalet aspekter att beakta för variationsadministration och buffertadministration med implikationer för kapacitetsadministrationen. Det visade sig att besluten tenderar att vara baserat på intuition och erfarenheter i tillverkande företag, mycket till följd av en avsaknad av beslutsstöd. Vidare framgår det att de medverkande företagen upplever att flera av deras interna rutiner bidrar till upphovet av variationer. Denna forskning bidrar till en ökad medvetenhet om orsaker till variationer som är påverkbara inom företag, möjliga åtgärder för att reducera variationerna och syftet med olika buffertar för att absorbera variationer. Detta är avsett att underlätta ett systematiskt arbetssätt för att reducera och absorbera variationer, samt utgöra ett stöd för variationsadministration och buffertadministration från ett kapacitetsadministrationsperspektiv.
KOPability

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Ågren, Martin. "30-year (1983-2013) trends in saliva flow rate and saliva buffer capacity. Analyses from 10-year repeated, cross-sectional population samples in the Jönköping area." Thesis, Örebro universitet, Institutionen för hälsovetenskap och medicin, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-44933.

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Terci, Adriana Oliveira. "Xerostomia em pacientes idosos: relação com o fluxo salivar, proteínas totais, capacidade tampão, pH e medicação em uso." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/23/23139/tde-22042008-115758/.

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O objetivo deste trabalho foi o de investigar as relações entre a queixa de boca seca, em uma população de idosos em bom estado geral, com o fluxo salivar não estimulado, a concentração de proteínas salivares, o pH e a capacidade tampão da saliva, além de considerar as medicações de uso diário consumidas por esses indivíduos. Foram selecionados de forma seqüencial e aleatória 85 pacientes, 13 homens e 72 mulheres, entre os 60 e 82 anos de idade, com média de 68,5 anos. Vinte e um pacientes, todos do sexo feminino, apresentaram queixa de boca seca, quando questionados. Sessenta e sete pacientes utilizavam algum tipo de medicação (79% da casuística). Dezoito indivíduos não consumiam medicamentos, 15 entre os não queixosos de boca seca e apenas três entre os que apresentaram queixa de boca seca. Foram colhidas amostras de saliva de todos os indivíduos, segundo técnica de expectoração não estimulada para recipiente mantido sob refrigeração, durante 15 minutos. Foram feitas, imediatamente após a coleta, o cálculo do fluxo salivar em mililitros por minuto, as medidas do pH, da capacidade tampão e reservados 2ml de saliva em recipiente refrigerado para os procedimentos da pesquisa da concentração proteica salivar. Ainda após a coleta foi aferida a glicemia pós-prandial dos pacientes. Obtivemos os seguintes resultados: Fluxo salivar médio geral de 0,21ml/min; mulheres com queixa 0,16 ml/min; e pacientes sem queixa 0,22ml/min. Capacidade tampão geral de 0,42; mulheres com queixa 0,46; pacientes sem queixa 0,40. Com relação ao pH média geral de 7,22; mulheres com queixa 7,0; pacientes sem queixa 7,22. Concentração de proteínas totais média geral 2,98mg/ml; mulheres com queixa 3,30 mg/ml; pacientes com queixa 2,88 mg/ml. Concluímos que a queixa de xerostomia é mais comum em mulheres e pacientes de maior idade, apresentando correlação positiva com fluxo salivar baixo, maior concentração proteica e maior consumo de medicamentos de uso crônico
The purpose of our trial was to investigate the influence of salivary flow rate, pH, protein content and buffer capacity over the symptom of xerostomia in a population of elderly people exhibiting good health. Eighty-five individuals were randomly selected, 13 men and 72 women, 60 to 82 years, mean 68.5. Twenty-one female patients presented dry mouth complaint when questioned. Seventy-seven patients (79%) were using some type of medication. Eighteen patients were not using drugs, 15 with no dry mouth complaint and three with xerostomia. Unstimulated whole saliva was collected for a period of 15 minutes to a refrigerated recipient. Salivary flow rate, pH and buffer capacity were measured immediately after sampling. Protein concentration was measured later at the lab center in a 2ml sample reserved for this procedure. Additionally, all patients had their glucose level taken. The following results were obtained: mean salivary flow rate of 0,21 ml/min, 0,16 for xerostomia patients and 0,22 for non-xerostomia patients. Mean salivary buffer capacity of 0,42; 0,46 for xerostomia patients and o,40 for non xerostomia patients. Mean pH of 7,22; 7,0 for xerostomia patients and 7,22 for non xerostomia patients. Mean protein concentration of 2,98 mg/ml; 3,30 for xerostomia patients and 2,88 for non xerostomia patients. We concluded that xerostomia is more prevalent in women and older patients, presenting positive correlation with low salivary flow rate, greater protein concentration and multiple drug use.

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Simonsson, Anton, and Viktor Åberg. "Beräkningsmetod för påverkan av driftstörningar i produktionssystem med serie-parallella flöden." Thesis, KTH, Hållbar produktionsutveckling (ML), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-276684.

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I det här arbetet eftersökte Scania IM en metod för att beräkna maskiners påverkan på output för en produktionslina vid driftstörningar. Metoden skulle kunna appliceras på en produktionslina med ett serie-parallellt flöde och arbetet utgick från en utvald lina där man bearbetar cylinderhuvuden. Vid framtagandet av beräkningsmetoden skapades det som i arbetet kallas för påverkansfaktor som tar fram vilken påverkan ett bortfall av en maskin i flödet har på flaskhalsutrustningen, som i sin tur står för den yttersta begränsningen för systemet. På seriella stationer erhålls en påverkansfaktor på 100 % men på stationer med parallell utrustning så finns det en kvarvarande kapacitet vid driftstopp av enstaka maskiner vilket är beroende av hur många maskiner samt vilken utnyttjandegrad de hade i ursprungsläget. Vid framtagandet av beräkningsmetoden togs inspiration från tidigare arbeten inom detta område men anpassades eller förenklades för att möta behoven från underhållsavdelningen. En utveckling av metoden gjordes även för att kunna analysera historiska data där information omproducerad variant saknas och då används ett viktat genomsnitt för påverkansfaktorn. Påverkansfaktorn bortser från buffertars påverkan på systemet men hur de ska inkorporeras undersöktes och därav togs ett förslag fram där kritisk driftstoppstid (critical downtime) används tillsammans med påverkansfaktorn för att ta hänsyn till såväl buffertar som parallell utrustning. Ett verktyg skapades för Scania IM för att underlätta användandet av framtagna beräkningsmetoder. Det som kvarstår efter avslutat arbete är att över tid testa de framtagna metoderna för att undersöka hur väl de överensstämmer med verkligt produktionsutfall. Detta kunde ej genomföras under gällande situation då produktionen ej var i drift enligt normalläge under tidsperioden för arbetet.
For this thesis, Scania IM sought a method for calculating the impact of machine downtime on the output of a production line. The method was created to be applied on a production line with a seriesparallel flow and was constructed based on a selected line where cylinder heads are machined. To achieve this a variable called impact factor was created that produces the effect an individual machines downtime has on the bottleneck equipment for the production line, which in turn accounts for the utmost limitation of the system. At serial stations, an impact factor of 100% is obtained, but at stations with parallel equipment, there is a remaining capacity if at least one machine is functioning. The amount on remaining capacity is dependent on how many of the parallel machines that are malfunctioning and the degree of utilization they had in the original state. In developing the calculation method, inspiration was taken from previous work regarding similar subjects, but it was either adapted or simplified to meet the needs of the maintenance department for the production line. A further development of the method was also made to be able to analyze historical data where information on the produced variant of cylinder heads is missing which led to the use of a weighted average for the impact factor. The impact factor ignores the effects of buffers on the system output, but how they are to be incorporated was investigated and a proposal was therefore made where critical downtime is used together with the impact factor to take into account both buffers and parallel equipment. A tool was created for Scania IM where they can perform these calculations. What remains after completion of the thesis is to test the developed methods over time to examine how well they correspond to actual production data. This could not be done during the time of this thesis due to the current situation when production was not operating according to normal conditions.

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Бабій, Ю. Ю., and Н. М. Слободян. "Оцінка енергоефективності системи опалення з використанням буферних ємностей." Thesis, ВНТУ, 2018. http://ir.lib.vntu.edu.ua//handle/123456789/23847.

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В даній статті розглядається принцип роботи теплоакумулятора та переваги використання їх в системі опалення
The principle of operation of the heat accumulator and the advantages of using it in the heating system is considered in this article.

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Chen, Minjie Ph D. Massachusetts Institute of Technology. "Stacked switched capacitor energy buffer architecture." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/73699.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (p. 133-134).
Electrolytic capacitors are often used for energy buffering applications, including buffering between single-phase ac and dc. While these capacitors have high energy density compared to film and ceramic capacitors, their life is limited and their reliability is a major concern. This thesis presents a series of stacked switched capacitor (SSC) energy buffer architectures which overcome this limitation while achieving comparable effective energy density without electrolytic capacitors. The architectural approach is introduced along with design and control techniques which enable this energy buffer to interface with other circuits. A prototype SSC energy buffer using film capacitors, designed for a 320 V dc bus and able to support a 135 W load has been built and tested with a power factor correction circuit. This thesis starts with a detailed comparative study of electrolytic, film, and ceramic capacitors, then introduces the principles of SSC energy buffer architectures, and finally designs and explains the design methodologies of a prototype circuit. The experimental results successfully demonstrate the effectiveness of the approach.
by Minjie Chen.
S.M.

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Boo, Hyun Ho. "Virtual ground reference buffer technique in switched-capacitor circuits." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99812.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 121-125).
The performance of switched-capacitor circuits depends highly on the op-amp specifications. In conventional designs, trade-offs in speed, noise, and settling accuracy make it difficult to implement power-efficient switched-capacitor circuits. The problem originates from the inverse relationship between the feedback factor and the signal gain. This thesis proposes the virtual ground reference buffer technique that enhances performance by improving the feedback factor of the op-amp without affecting signal gain. A key concept in the technique is the bootstrapping action of level-shifting buffers. It exploits op-amp-based circuits whose principles are very well understood and the design techniques are mature. The solution ultimately relaxes the required op-amp requirements including unity-gain bandwidth, noise, offset voltage and open-loop gain that would otherwise result in complex design and high power consumption. The concept is demonstrated in a 12-b 250MS/s pipelined ADC.
by Hyun Ho Boo.
Ph. D.

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Junior, Walter Luiz Siqueira. ""Estudo de alguns parâmetros salivares em indivíduos com síndrome de DOWN"." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/23/23140/tde-13062005-115943/.

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O objetivo deste estudo foi mensurar o fluxo salivar, pH, capacidade tampão, concentrações de proteína total e ácido siálico, atividades das enzimas amilase e peroxidase e concentração dos íons sódio, potássio, cálcio, fósforo, zinco e magnésio em saliva total de indivíduos síndrome de Down com idade entre 1 e 25 anos. Nos indivíduos com idade entre 1 e 5 anos a saliva total foi coletada através de uma leve sucção, enquanto que nos outros indivíduos com idade entre 6 e 10, 11 e 15, 15 e 20, 21 e 25 a saliva total foi coletada com estimulação mecânica através da mastigação de parafilm, durante 10 minutos. O pH e a capacidade tampão foramdeterminadas usando um pHmetro digital. A capacidade tampão foi mensurada através de titulação com HCl a 0,01N. A concentração de eletrólitos foi determinada através de um espectrofotômetro de emissão atômica com fonte de excitação de argônio induzido. A proteína total foi mensurada através do reagente de Folin. A atividade da amilase foi mensurada através da produção de maltose e a atividade da peroxidase foi mensurada através da utilização de orto-dianisidina. Para a analise estatística os dados foram apresentados em media ± desvio padrão. Foi utilizado o teste t de Student para determinar as diferenças entre as medias dos indivíduos síndrome de Down e o grupo controle. Nenhuma diferença significante foi observada na concentração de ácido siálico, fósforo, zinco, magnésio e cálcio entre os indivíduos síndrome de Down e o grupo controle. A concentração de sódio, proteína total e a capacidade tampão demonstraram ser maior nos indivíduos com síndrome de Down em comparação ao grupo controle. Por outro lado, o fluxo salivar, a concentração de potássio, e a atividade das enzimas amilase e peroxidase foram menores no grupo síndrome de Down quando comparado ao grupo controle. Estes resultados sugerem que as pessoas com síndrome de Down apresentam alterações no metabolismo do ducto e/ou das células acinares das glândulas salivares.
The aim of this study was to measure the flow rate, pH, buffer capacity, sialic acid, total protein concentrations, amylase and peroxidase activities and sodium, potassium, calcium, phosphorus, zinc and magnesium concentration whole saliva of individuals with Down syndrome aged 1 - 25 years. In individuals aged 1-5 years the whole saliva was collected under slight suction, while in the others individuals aged 6-10, 11-15, 15-20, 21-25 the whole saliva was collected with stimulation by chewing a piece of parafilm, for 10 minutes. The pH and the buffer capacity were determined using a digital pHmeter. The buffer capacity was measured by titration with 0.01 N HCl. Electrolyte concentrations were determined by inductively coupled argon plasma with atomic emission spectrometry. Sialic acid was determined by thiobarbituric acid assay. Protein was determined by the folins phenol reagent. Amylase was assayed measuring the maltose produced by the breakdown of starch and peroxidase with ortho dianisidine. For statistical analysis the date are presented as mean ± SD. Students t test was used to determine differences between the mean of the Down syndrome and control groups. No statistically significant differences were observed in sialic acid, phosphorus, zinc, magnesium and calcium concentration between the individuals with Down syndrome and control group. The sodium and total protein concentration and buffer capacity showed higher in the Down syndrome than in the control group. On the other hand the flow rate and potassium concentration, amylase and peroxidase activities were lower in the Down syndrome than in the control group. These results suggest that the Down syndrome persons present alteration in the metabolism of the duct and/or acinar cells of salivary glands.

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Ferrari, Linda. "Studio preliminare degli effetti dell'allacciamento di un serbatoio "buffer" nel sistema di approvvigionamento idrico della Romagna." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/17138/.

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Lo studio affronta gli effetti e le potenzialità derivanti dall’aumento della capacità di invaso nel sistema di approvvigionamento idrico della Romagna a seguito dell’introduzione di un ulteriore serbatoio, collocato sul bacino del fiume Rabbi, ed allacciato alla rete attuale. La funzione principale del nuovo serbatoio è quella di invaso ausiliario, ovvero fornisce acqua all’invaso di Ridracoli nei momenti in cui questo viene a trovarsi in condizioni di scarsità idrica, smorzando, o, eventualmente, annullando i periodi di crisi. Lo studio è stato condotto ipotizzando due scenari di possibile allacciamento, e facendo variare la capacità di invaso sul Rabbi da 1 a 30 Mmc, al fine di ricercare le sue dimensioni ottimali. Il primo scenario ipotizza di inviare l’acqua dal Rabbi alla diga di Ridracoli per mezzo di un by-pass indipendente, mentre, il secondo, tramite un collegamento alla galleria di gronda; l’incremento di volume potabilizzato è stato confrontato sia con quello storico, sia con simulazioni che implementano regole di gestione ottimizzata del serbatoio di Ridracoli. L’analisi è stata condotta implementando un codice numerico in ambiente Matlab, in grado di restituire in output, per ciascuno scenario, l’aumento di volume potabilizzato a Ridracoli. Dai risultati si evince che una capacità di invaso superiore ai 20 Mmc non produce ulteriori benefici in termini di volume potabilizzato. È stata, infine, condotta un’analisi costi-benefici con l’obiettivo di valutare il risparmio di costi di esercizio derivante dai volumi sottratti alle fonti locali, a parità di richiesta complessiva a valle della rete. I risultati mostrano che, nell’ipotesi di serbatoio più grande, è possibile ottenere un risparmio di costi di esercizio per la potabilizzazione dalle fonti locali di circa l’11% a fronte di una spesa per l’aumento dei volumi potabilizzati da Ridracoli di circa il 4%.

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Al-Atbee, Osama Yaseen Khudair. "A versatile power electronic interface for a fuel cell and ultra-capacitor energy buffer for a DC micro-grid system." Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/40975.

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Micro-grid systems are small-scale power supply networks that are designed to provide electricity to a local community from local generators. Micro-grids operate with a common AC or DC bus, and power converters are key components for interfacing the generators and storage devices (and sometimes the loads) to the common bus. The aim of this research study is to investigate and develop high-efficiency power electronic converters for the interconnection of fuel cells and ultra-capacitors to a DC micro-grid for stationary power distribution systems. The converter for the fuel cell and its dynamic control have been designed, simulated, and further improved by introducing a new modified active clamp circuit that enhances performance and increases the efficiency of the converter. This new modification has been designed and verified by PSpice/Simulink approach and implemented using dSPACE. To control the power flow status of the ultra-capacitor, a bidirectional DC–DC converter is required. A number of different alternative DC–DC converter topologies were compared. It was concluded that, the bidirectional voltage–fed topology is better suited for dealing with the fast dynamic response of the ultra-capacitor. However, this topology exhibits a higher circulating power flow and higher conduction losses. Based on this limitation, a modulation scheme that minimises the circulating power flow in the converter was introduced and this was verified by simulations. The hardware for the ultra-capacitor (bi-directional) converter has also been designed and implemented. The test results demonstrate the ability of the converter for fast and bidirectional power flow. The development of simulation models and the control system are experimentally implemented in dSPACE.

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33

Christensson, Rebecka, and Rebecka Gustavsson. "Hantering av stokastiska variationer : Val av säkerhetskapacitetsbuffert baserat på kundorderpunktens position." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Industriell organisation och produktion, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-41384.

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Syfte – Studien syftar till att kartlägga hur kundorderpunktens position förhåller sig till företags val av säkerhetskapacitetsbuffertar för att hantera stokastiska variationer i kapacitetsbehov. Därmed är studiens frågeställningar: Vilka är de huvudsakliga säkerhetskapacitetsbuffertarna som används för att hantera stokastiska variationer i kapacitetsbehov? Hur förhåller sig kundorderpunktens position till val av säkerhetskapacitetsbuffertar för att hantera stokastiska variationer i kapacitetsbehov? Metod – För att besvara studiens frågeställningar har en fallstudie genomförts och inkluderar en litteraturstudie, intervjuer och dokumentstudier. Intervjuer genomfördes med sju respondenter från sex företag och empirin som framkom från intervjuerna och dokumentstudier analyserades tillsammans med teori från litteraturstudien för att få fram studiens resultat. Resultat – Studien har identifierat tio tillvägagångssätt för att hantera stokastiska variationer, varav två som inte tidigare nämnts av studiens teoretiska ramverk. De tio tillvägagångssätten har därefter kategoriserats in i sex säkerhetskapacitetsbuffertar baserat på likheter. Efter identifiering av kundorderpunktens position har möjliga kopplingar mellan kundorderpunktens position och val av säkerhetskapacitetsbuffert analyserats för att undersöka eventuella samband. Tre tendenser till kopplingar har identifierats men vidare studier krävs för att säkerställa kopplingarna. Implikationer – Området kring hantering av variationer i kapacitetsbehov med en uppdelning i en kapacitetsbuffert och en säkerhetskapacitetsbuffert är relativt outforskat. Att undersöka eventuella kopplingar mellan val av säkerhetskapacitetsbuffertar och kundorderpunktens position kan fylla ett kunskapsgap och kan teoretiskt bidra till vidare studier inom området säkerhetskapacitetsbuffertar. Genom att lära av andras erfarenheter ges en ökad förståelse vilket kan hjälpa företag att fatta mer välgrundade beslut vilket kan leda till förbättrad prestation, vilket är studiens praktiska bidrag. Begränsningar – Studiens begränsning ligger i att endast sju respondenter från sex företag ingick i studien, där endast en intervju gjordes med respektive respondent. Antalet använda tillvägagångssätt och deras kopplingar till kundorderpunktens position hade kunnat stärkas ifall ett större antal respondenter från olika typer av företag deltagit i studien. Därigenom hade kopplingarnas generaliserbarhet kunnat stärkas. Dessutom hade troligtvis fler tillvägagångssätt identifierats ifall en större bredd studerats. I studien har den totala kapaciteten hanteras som två separata delar för hantering av förväntade och oväntade behov. Infallsvinkeln är relativt ny och är inte etablerad vilket kan försvåra och begränsa förutsättningen för verksamheter att applicera resultatet.
Purpose – The study aims to map how the position of the order penetration point is related to companies’ choice to handle stochastic variations in capacity requirements through the use of safety capacity buffers. Hence, the research questions are: 1. Which are the main safety capacity buffers used to handle stochastic variations in capacity requirements? 2. How is the position of the order penetration point related to the choice of safety capacity buffers to handle stochastic variations? Method – A case study has been conducted in order to answer the research questions and thus includes a literature study, interviews and document studies. The interviews were conducted with seven respondents from six companies and the empirical data that emerged from the interviews and document studies were analysed together with theory from the literature study to reach the result of the study. Findings – The study has identified ten approaches to handle stochastic variations, two of which was not previously mentioned in the theoretical framework. The ten approaches have then been categorized into six safety capacity buffers based on similarities. After identifying the position of the order penetration point possible connections between the position of the order penetration point and choice of safety capacity buffers have been analysed to explore possible relationships. Three tendencies to connections have been identified but further studies are required to ensure the connections. Implications – The research area of handling variations in capacity requirements with a division in one capacity buffer and one safety capacity buffer is relatively unexplored. Exploring possible connections between the choice of safety capacity buffers and the position of the order penetration point could fill a gap of knowledge and theoretically contribute to further research within the area of safety capacity buffers. Learning of others’ experiences gives an increased understanding which can help companies to make more informed decisions that can lead to better performance, which is the practical contribution of the study. Limitations – The studies limitations lies in that only seven respondents from six companies were included in the study, were only one interview was conducted with each respondent. The number of used approaches and their connections to the order penetrations point could have been strengthened in case an increased number of respondents from different kind of companies had participated in the study. Thereby the connections’ generalizability could have been strengthened. Additionally more approaches probably would have been identified in case a greater width had been studied. In the study the total capacity have been handled as two separated parts to handle expected and unexpected requirements. The approach is relatively new and not established which can complicate and limit the ability for companies to apply the results.

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Umurigirwa, Benitha Sandrine. "Élaboration et caractérisation d'un agromatériau chanvre-amidon pour le Bâtiment." Thesis, Reims, 2014. http://www.theses.fr/2014REIMS017/document.

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Afin de diminuer les consommations énergétiques, plusieurs pays Européens, y compris la France, ont mis au point de nouvelles normes permettant d'optimiser les performances énergétiques de l'enveloppe du bâtiment. Ceci peut entraîner l'augmentation de l'humidité relative, ce qui peut nuire à la santé des occupants et dégrader la structure du bâtiment. Utiliser des éco-matériaux tel que le béton de chanvre est une solution prometteuse permettant d'assurer le confort à l'intérieur du bâtiment, en régulant l'humidité relative. L'objectif principal de cette thèse est d'élaborer, optimiser et caractériser un agromatériau à base de la chènevottes défibrée avec un liant d'amidon de blé. La formulation du chanvre-amidon est étudiée en variant le rapport massique amidon/chanvre et son impact sur les propriétés mécaniques. Le coefficient d'absorption acoustique est mesuré pour la composition optimale. Pour améliorer les propriétés d'adhésion à l'interface chanvre/amidon, un traitement de surface à base d'hydroxyde de sodium NaOH suivi par un agent de couplage (3-glycidyloxypropyl) triméthoxysilane ont été effectués. L‘influence du traitement de surface sur les fibres de chanvre a été analysée au microscope électronique à balayage (MEB), par la calorimétrie différentielle à balayage (DSC), l'analyse thermographique (ATG) et par la spectroscopie infrarouge à transformée de Fourier (FTIR). Les propriétés hygrothermiques du matériau chanvre-amidon avec et sans traitement de fibres sont également étudiées. Ces propriétés comprennent la courbe d'isotherme de sorption, la perméabilité à la vapeur d'eau, la conductivité thermique et la capacité tampon hydrique du matériau
In order to control energy consumption, several European countries including France, adopted regulations to optimize the energy performance of the building envelope. This fact could increase the level of indoor relative humidity which can affect the health of the occupants and causes material damage. Using eco-friendly materials such as hemp concrete which can buffer indoor moisture levels might contribute to maintain high indoor comfort.The main purpose of this thesis is to optimise and characterize a construction material made of hemp hurds and wheat starch binder.The formulation of the hemp-starch is studied by varying starch/hemp ratio and its impact on mechanical properties. Sound absorption coefficient is measured for optimal composition. To improve the adhesion between hemp fibers and starch matrix, alkali treatment with sodium hydroxide was performed to solubilize hemicelluloses and lignin seal surrounding the cellulose bundle in the first step and then a silane coupling agent (3-glycidyloxypropyl) trimethoxylsilane was used to provide a stable bond between hemp fibres and starch matrix. The influence of the treatments were investigated by scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA) and attenuated total reflectance spectroscopy (ATR). After the treatments, mechanical properties of hemp-starch material were studied.Hygrothermal properties of hemp-starch material with and without fibre treatment were also measured. These properties include sorption isotherm curve, water vapour permeability, thermal conductivity and moisture buffering value

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Heaton, Tim D. "Digital Logic Gate Characterization with Gallium NitrideTransistors." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555641604378544.

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呂俞鋒. "The Study of Multi-Project Management on the Issues of Capacity Buffer Allocation and Buffer Sizing." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/44455000327964983009.

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碩士
明新科技大學
工業工程與管理研究所
97
Critical chain project management, proposed by Dr. Goldratt, has been proved to be very prominent in overcoming the weaknesses of human nature in order to achieve a more effective project management. The mechanism of his theory is based on the concept of risk-sharing. This releases the protection time (i.e. buffer time) traditionally reserved for individual resources/tasks and reassigns it to the most effective way in protecting projects. Dr. Goldratt proposes the mechanism of synchronization to reduce chances of multi-tasking and hence speeding up the project. The most important design is the notion of capacity buffer. Capacity buffer is a time interval between two projects in a sequence. There are two issues remaining unresolved until now. One is how to configure a buffer among projects in order to achieve the best protection and to save the most time in project schedule. The other is how much capacity buffer should be set effectively while assuring no delaying on promised timetable. By using @Risk simulating software, this research determines the best allocation of buffer capacity to assure the most effective protection and to maintain the shortest project schedule. Also, the article studies the influence on project completion caused by uncertainty and rash order problems. The study concludes that no matter in total projects time, on-time delivery and project orders, Distributed Buffer Allocation performs better than Centralized Buffer Allocation proposed by Dr. Goldratt. The shortest duration can be achieved by setting the distributed allocation CB between 80%-100%. In addition, the study also makes some statements regarding the relationship between buffer size setting and rash orders of various risk levels.

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Park, Taeho. "Determination of buffer capacity for flexible manufacturing cell flow lines." 1987. http://catalog.hathitrust.org/api/volumes/oclc/17935560.html.

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Thesis (Ph. D.)--University of Wisconsin--Madison, 1987.
Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 163-171).

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HONG, GUO-FENG, and 洪國峰. "Performance evaluation and buffer-capacity design of sequential production lines." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/10633529933950807760.

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Lu, Yu-Chi, and 盧俞錡. "Measurements of Heat Capacity of Mixed-Solvent Desiccant (MgCl2/Glycol/H2O) and Aqueous Buffer Solutions (Buffer/Glycol/H2O)." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/65989310007739613639.

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碩士
中原大學
化學工程研究所
99
In this study, the heat capacities of ternary systems of salt/glycol/H2O and buffer/glycol/H2O were measured over the temperature range 30 to 80℃ and different solute concentrations: salt/buffer (4.0, 9.0, 16.0 wt %) + glycol (40 wt %) using a heat flow differential scanning calorimeter (DSC). The salt was magnesium chloride (MgCl2．6H2O) ; the buffers were N-[tris(hydroxymethyl)methyl] -3-aminopropanesulfonic acid (TAPS) and tris (hydroxymethyl) amionmethane (TRIS); and the glycols were diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (T4EG), propylene glycol (PG), tripropylene glycol (TPG), dipropylene glycol (DPG). For the pure system, the dependence of the molar heat capacity with temperature was correlated by a second order equation. The binary system of TPG + H2O for molar heat capacities and excess molar heat capacities were using a Redlich-Kister-type equation. The data were then reported as functions of temperature and composition. For the ternary systems, an equation proposed by Söhnel and Novotñy was used to represent the measured heat capacity data. Results showed that the measured heat capacity data were satisfactorily correlated using the applied correlations. Therefore, results presented in this are, in general, of sufficient accuracy for most engineering-design calculations

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王輔卿. "Upgrading the service capacity of video-on-demand servers with memory buffer." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/27498156488481550693.

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Greenwood, Dale Eldon. "Small intestinal pH and buffer capacity implications for dissolution of ionizable compounds /." 1994. http://catalog.hathitrust.org/api/volumes/oclc/68797305.html.

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Hung, Ling-Chi, and 洪鈴琪. "The Effect of Toe-in And Toe-out Gait On Buffer Capacity At Landing." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/57149083847119865311.

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碩士
國立臺北教育大學
體育學系碩士班
99
Abstract Objctive: The aim of this research is to study the effects of different landing angles toe-in, toe-out, and neutral barefoot gait from the height of 60cm on the lower limb joints, ground reaction forces and EMG signals.Methods: 15 female fifth graders respectively with toe-in, toe-out, and neutral gait (five in each group) are selected from Taipei City to participate in this study.(age: 11.2±0.4 years old, height: 145.3±7.2 cm, weight: 39.8±8.5 kg). A Mega speed 30k high speed camera (100Hz), an AMTI force plate (1000Hz),and four Biovision EMG system (1000Hz) are used to synchronously capture kinematical , dynamics and lower limbs EMG parameters of landing. The film undergoes Kwon3D movement analysis and human limb sections of parameter organizational system and Direct Linear Transformation in order to possess the physical parameters. The primitive signal from the force plate is processed by DasyLab 6.0 software, low-pass filtering (10Hz) and calibrates modular to calculate the primitive three dimension counterforce, and then obtain the impulse value through integration analysis. The primitive signals of EMG is processed by DasyLab 6.0 software, band-pass filtering, low-pass filtering (10Hz) and full-wave rectification, also obtain the integration EMG through integration analysis. MVC is used to normalize signals of EMG. The resulting data undergoes one-way ANOVA via SPSS 12.0 statistics software. The level of significance for this experiment is set to α=.05.Results: 1.The angles of the hip and knee joints of the both the toe-in and toe-out gait groups at their lowest center of gravity are significantly greater than that of the neutral gait group. (p <.05). Knee joint angles displacement at buffer phase, the greatest angular velocities of knee joints, center of gravity vertical displacement, and buffering time are significantly smaller than that of the neutral landing group. The hip joint displacement at buffer phase, the greatest angular velocities of hip joint, and the forward inclination angle of the torso of the toe-in gait group are significantly smaller than that of the neutral landing. 2.The greater loading rate, the rate of peak vertical reaction force, and 50ms passive impulse of the toe-in gait group are greater than that of the neutral landing group. (p <.05). 3.The degrees of rectus femoris activation of the toe-in and toe-out gait groups are significantly greater than that of the neutral landing group. (p <.05).Conclusion: The angle of different landing position (toe-in, toe-out, and neutral landing gait) is one of the factors affecting the drop landing action. With regards to landing buffer capacity. The neutral gait group shows better performance than the toe-in group since the latter lands with a more erect stiffness. The neutral gait group engages more time and movement of the torso, hip, and knee joints for buffering than do the other two groups. By using less rectus femoris units to stabilizing the knee flexion of the joints, the tremendous friction produced while landing is therefore effectively reduced. In order to avoid injury caused by toe-in or toe-out gait, it is suggested that one takes the neutral landing position with the tip of the feet pointing forward.

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43

"Performance Analysis of a Double Crane with Finite Interoperational Buffer Capacity with Multiple Fidelity Simulations." Master's thesis, 2018. http://hdl.handle.net/2286/R.I.50466.

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abstract: With trends of globalization on rise, predominant of the trades happen by sea, and experts have predicted an increase in trade volumes over the next few years. With increasing trade volumes, container ships’ upsizing is being carried out to meet the demand. But the problem with container ships’ upsizing is that the sea port terminals must be equipped adequately to improve the turnaround time otherwise the container ships’ upsizing would not yield the anticipated benefits. This thesis focus on a special type of a double automated crane set-up, with a finite interoperational buffer capacity. The buffer is placed in between the cranes, and the idea behind this research is to analyze the performance of the crane operations when this technology is adopted. This thesis proposes the approximation of this complex system, thereby addressing the computational time issue and allowing to efficiently analyze the performance of the system. The approach to model this system has been carried out in two phases. The first phase consists of the development of discrete event simulation model to make the system evolve over time. The challenges of this model are its high processing time which consists of performing large number of experimental runs, thus laying the foundation for the development of the analytical model of the system, and with respect to analytical modeling, a continuous time markov process approach has been adopted. Further, to improve the efficiency of the analytical model, a state aggregation approach is proposed. Thus, this thesis would give an insight on the outcomes of the two approaches and the behavior of the error space, and the performance of the models for the varying buffer capacities would reflect the scope of improvement in these kinds of operational set up.
Dissertation/Thesis
Masters Thesis Industrial Engineering 2018

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44

Lai, Chia Hung, and 賴佳宏. "Efficient LTE Uplink Scheduling by Taking into Account of Buffer Capacity and Packet Delay Budget." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/59955078834394296640.

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碩士
國立中興大學
資訊科學與工程學系
102
SC-FDMA is the technology adopted for the LTE uplink transmission, which meets the requirements of continuous resource block allocation and modulation and coding scheme (MCS). Most previous studies of SC-FDMA focus on high throughput and fair transmission. Due to the variety of UE requests, traditional channel signal measure alone is not adequate for efficient resource allocation. In this paper, we propose an Urgency-Based Scheduling (UBS) to reflect the urgency of requests by taking into account the packet delay budgets as well as remaining buffer spaces. We calculate the scheduling priority for both categories of GBR (Guaranteed Bit Rate) services and Non-GBR services and determine the resource blocks assignment, which satisfies both the continuity and MCS requirements. By randomly generating UEs’ requests and channel qualities, we made a simulation of 40 application scenarios. The simulation results show that UBS outperforms round robin scheduling (RR) and channel dependent scheduling (CDS) in reducing the average packet loss rate and has significant improvement in average packet delay.

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45

Lai, Yi-Lin, and 賴宜伶. "Application of Drum-Buffer-Rope to the Capacity Planning of Wafer Fabrication with Time Constraint." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/44851783407599461769.

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碩士
中原大學
工業工程研究所
94
Time constraint is applied after the cleaning and banking process to avoid wafer contamination in semiconductor manufacturing. Any lot failing to meet the time constraint needs to be reworked. Therefore, it is important to control the work-in-process (WIP) level to reduce the number of lots whose waiting time exceeds the time constraint. From the viewpoint of Theory of Constraints (TOC), bottleneck machine governs the system throughput. Therefore, it is critical to control the WIP level in front of the bottleneck machine in the process with time constraint requirement. This research develops a capacity planning system (CPS) for the backend process of semiconductor manufacturing with reentrant process. CPS applies TOC to manage time constraint, so lot rework and capacity loss can be minimized. CPS determines the expected WIP level using TOC’s Drum-Buffer-Rope mechanism and then controls wafer release to meet the expected WIP level. The best combination of WIP level and time constraint is identified by simulation study and response surface analysis. Simulation results reveal that CPS can significantly reduce lot rework and capacity loss in different production scenarios.

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46

Chen, Chin-Heng, and 陳致亨. "Constructing the Capacity Constrained Drum-Buffer-Rope Shop Floor Control Model─An example for Textile Industry." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/94213159574248044572.

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碩士
中原大學
工業工程研究所
92
The application of Theory of Constraint (TOC) and Drum-Buffer-Rope (DBR) in practice is to manage the bottleneck resources to enhance all dimensions of performance of the system. The purpose of Shop Floor Control (SFC) is to ensure that the pace of shop floor production is smooth. SFC is in charge of the short term detail plans, execution and monitor activities. It has to provide the feedback information of the shop floor production to give assistances for managers to make appropriate managerial decisions and prompt problem-solving actions. The main purpose of this research is to construct a shop floor manage model with an emphasis on Capacity Constrained Resources (CCR) by the three shop floor managerial techniques mentioned above. And then verify the model on the basis of the data collected at the real production floor to make this model fill the bill of shop floor requirement. Through the result of final verification, we can confirm that this model works well on the reduction of shop floor material and stocks of WIP. And it also has good performance on the improvement of order delay and reduction of total production time.

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47

Chen, M., X. L. Jin, Y. Z. Wang, X. Q. Cheng, and Geyong Min. "Modelling priority queuing systems with varying service capacity." 2013. http://hdl.handle.net/10454/9635.

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No
Many studies have been conducted to investigate the performance of priority queuing (PQ) systems with constant service capacity. However, due to the time-varying nature of wireless channels in wireless communication networks, the service capacity of queuing systemsmay vary over time. Therefore, it is necessary to investigate the performance of PQ systems in the presence of varying service capacity. In addition, self-similar traffic has been discovered to be a ubiquitous phenomenon in various communication networks, which poses great challenges to performance modelling of scheduling systems due to its fractal-like nature. Therefore, this paper develops a flow-decomposition based approach to performance modelling of PQ systems subject to self-similar traffic and varying service capacity. It specifically proposes an analytical model to investigate queue length distributions of individual traffic flows. The validity and accuracy of the model is demonstrated via extensive simulation experiments.

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48

Awan, Irfan U. "Analysis of Multiple-Threshold Queues for Congestion Control of Heterogeneous Traffic Streams." 2006. http://hdl.handle.net/10454/4141.

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No
The use of queue thresholds is a well known technique for network traffic congestion control. This motivates the study of a single server queue with R(R ¿ 2) distinct priority classes under Head of Line (HoL) service priority discipline, Partial Buffer Sharing (PBS) scheme and a finite capacity vector N, representing a sequence of thresholds (N1, N2, ¿ , NR) for each class jobs. The external traffic is modelled using the compound Poisson process or generalised exponential (GE) distribution which can capture the bursty property of the network traffic. The transmission times have also been modelled using the GE distribution to depict the bulk departures from the system. Using a GE/GE/1/N approximation, a closed form cost-effective analytical solution is obtained using the principle of maximum entropy (ME). The forms of the joint, aggregate and marginal state probabilities, as well as basic performance measures such as utilisation and blocking probabilities are analytically established at equilibrium via appropriate mean value constraints and the generating function approach. Consequently, efficient recursive expressions of low computational cost are determined. Typical numerical experiments are included to illustrate the credibility of the proposed mechanism in the context of different QoS grades for various network traffic classes. This model, therefore, can be used as a powerful tool to provide a required grade of service to a particular class of traffic in any heterogeneous networks.

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49

Yu, Kun-ta, and 游坤達. "TCP Performance and Buffer Capacity Analysis of a Modified Multiple Reject ARQ at RLC Layer in UMTS Systems." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/54639325108010621153.

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碩士
義守大學
資訊工程學系碩士班
93
As development of information technology being fast and flourishing development of the internet network, all the functions of the cell-phone get improved tremendous. The telecommunication industry also entrusts with the cell-phone the more Internets service. Therefore the transmission from the UE to the far-end server overall networks is an important issue. In this thesis, we study the impact of the ARQ (Automatic Repeat reQuest) mechanism on RLC in W-CDMA systems, and how to obtain higher performance of TCP transmission. According to the ARQ mechanism in 3GPP specification, we modified the Multiple-Reject ARQ mechanism to improve the transmission performance and packets loss rate to enhance system’s performance. Because UMTS employs FDD, the error rates of uplink and downlink may different. To prevent the TCP transmission slowdown causing by the receiver RLC buffer overflow, we try to more effectively control the RLC buffer size in order to improve whole transmission speed in UMTS systems. Finally, we set up suitable UMTS simulation environment on NS-2 with EURANE, and carry on the network the analysis and the simulation. Under the Rayleigh fading environment, the simulation results show that the proposed MMR-ARQ outperforms the MR-ARQ3 of GPP in goodput upto 20 percent with almost the same number of ACKs and packet loss ratio.

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50

Lien, Po-jen, and 連博仁. "Application of a carbon-releasing substrate with pH buffer capacity and high mobility to remediate TCE-contaminated groundwater." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/59j56w.

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博士
國立中山大學
環境工程研究所
104
Soil and groundwater at many existing and former industrial areas and disposal sites are contaminated by halogenated organic compounds that were released into the environment. When they are released into the subsurface, they tend to adsorb onto the soils and cause the appearance of DNAPL (dense-non-aqueous phase liquid) pool. In this study, trichloroethylene (TCE) was used as the target compound for the feasibility and pilot-scale studies. In situ bioremediation of DNAPLs sites need to inject carbon substrates into the subsurface, which would cause the acidification and odor problems of the subsurface environment. This would deteriorate the groundwater quality and cause the increase in maintenance cost. In this study, a carbon-releasing substrate [mainly vegetable oil (castor oil) (with a low iodine value)] with pH buffer capacity (with citric acid and sodium hydrogen phosphate as buffering system) was developed. The microcosm study was performed to evaluate the feasibility of using the developed substrate to enahcne the reuctive dechlorination of TCE. In addition, molecular biology techniques [polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE)] were used to identify the dominant microcial sepcies and variations in microbial diversity, which can contribute to the contaminant biodegradation. The results show that the developed emulsified substrate could maintain a stable condition for a 72-h period. The average diameter and zeta potential of the oil globule was 299 nm and -13.3 mv, respectively, analyzed by the dynamic light scattering (DLS). Results from the microcosm study show that approximately 93% of the TCE can be removed and the pH was maintained neutral after 140 days of operation, and the first-order decay rate for TCE was 1.93 × 10-2 1/d. Results from the real-time PCR analyses show that the populations of Dehalococcoides spp. (DHC) increased from 2.33 × 102 on day 0 to 4.99 × 104 gene copies/g on day 120. The results indicate that the developed pH buffer carbon-releasing substrate was able to enhance the growth of DHC and also caused the increase in anaerobic TCE dechlorination rate.

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Dissertations / Theses on the topic 'Buffer capacity'

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