• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 22
  • 4
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 46
  • 12
  • 11
  • 8
  • 8
  • 8
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Exploring strategies used by older drivers during ingress and egress and their varying physical mobility

Leung, Dale January 2016 (has links)
The overall purpose of the present study was to examine the strategies used by older adults with regard to both foot placement and hand contact location as they enter (ingress) and exit (egress) a vehicle. A cross-sectional study was used to identify and, in turn, examine the participants’ ingress and egress strategies in relation to their physical mobility and other characteristics. All participants had a valid driver’s license and they completed the following: 1) demographic (self-report) questionnaires; 2) clinical measures of physical mobility (i.e. Timed Up and Go, Berg Balance Scale, One Legged Stance test, Rapid Pace Walk test). A physical mobility index was also developed using these clinical measures. During both ingress and egress, older drivers were more likely to use one-foot strategies, which are considered less stable. Participants who used one-foot ingress and egress strategies had better overall physical mobility. The armrest location was used by the majority of older drivers for both ingress and egress, and is used most often during one-foot strategies. Participants who used multiple hand contact locations during ingress/egress had lower physical mobility than participants who used a single hand contact location or made no contact with the vehicle. Finally, the results from this study can inform educational materials targeting this population and determining design changes to the automobile that can prevent injuries to older drivers. / Thesis / Master of Health Sciences (MSc)
42

Determination of the Leak Size Critical to Package Sterility Maintenance

Keller, Scott Wayne 09 April 1999 (has links)
This study was divided into four sections: the literature review; the mechanism by which a package defect becomes a leak; and the imposed pressures generated within a package during distribution; comparison of the threshold leak size to the critical leak size and their effect on loss of package sterility; and the relationships between microorganism characterisitics and the threshold leak size, and their effect on the critical leak size. Section II. The mechanism by which a package defect converts to a leaker in an effort to develop a relationship between the threshold leak size and loss of package sterility was studied. The threshold leak size is the hole size at which the onset of leakage occurs. The threshold pressure is that which is required to initiate a leak. Leak initiation was studied in terms of the interaction between three components: liquid attributes of liquid food products, defect size, and pressures required to initiate liquid flow. Liquid surface tension, viscosity, and density were obtained for sixteen liquids. The imposed pressures (Po) required to initiate flow through microtubes of IDs 0, 2, 5, 7, 10, 20 or 50 m, were measured using 63 test cells filled with safranin red dye, tryptic soy broth, and distilled water with surface tensions of 18.69 mN/m, 44.09 mN/m, and 64.67 mN/m, respectively. Significant differences were found between observed threshold pressures for safranin red dye, tryptic soy broth, and distilled water (p < 0.05). Liquids with small surface tensions such as safranin red dye required significantly lower threshold imposed pressures than liquids with large surface tensions such as distilled water (p < 0.05). An equation was developed to quantify the relationship between liquid surface tension, threshold imposed pressure, and defect size. Observed threshold pressures were not significantly different (p > 0.05) than those predicted by the equation. Imposed pressures and vacuums generated within packages during random vibration and sweep resonance tests were measured for brick-style aseptic packages (250 ml), metal cans size 76.2-mm x 114.3-mm (425 ml), quart gable top packages (946 ml), one-half gallon gable top packages (1.89 L) and one-gallon milk jugs (4.25 L). Significant differences were found between packages for observed generated pressures during vibration testing (p < 0.05). An equation to calculate the threshold like size based on liquid surface tension and imposed pressure was established. Section III. The onset of liquid flow through a defect as a result of imposed positive pressures or vacuum were linked to the sterility loss of a package. Five-hundred sixty-three test cells, each with microtubes of 0, 2, 5, 7, 10, 20 or 50 m, manufactured to simulate packages with defects, were biochallenged via an aerosol concentration of 106 cells/cm3 of Pseudomonas fragi Lacy-1052, under conditions of imposed positive pressure or vacuum of 20.7, 13.8, 6.9, 0, -6.9, -13.8, -20.7 kPa, respectively and temperatures of 4 , 25 and 37 C. A statistically significant relationship between loss of sterility due to microbial ingress in test cells and the initiation of liquid flow were found (p < 0.05). Microbial ingress was not found in test cells with microtube IDs of 2 m. Leak sizes critical to the sterility maintenance were found to be different based on the liquid surface tension, and imposed package pressures. The threshold leak size where the onset of liquid flow was initiated, and the critical leak size at which loss of sterility occured were not significantly different (p > 0.05). Section IV. The effects of microorganism size and motility, and the imposed pressure required to initiate liquid flow, on the leak size critical to the sterility of a package were measured. Pseudomonas fragi Lacy-1052, Bacillus atrophaeus ATCC 49337, and Enterobacter aerogenes ATCC 29007 were employed to indicate loss of package sterility. One hundred twenty-six microtubes with interior diameters (I.D.s) of 5, 10, and 20 m and 7 mm in length were used as the manufactured defects. Forty-two solid microtubes were used as a control. An equation was used to calculate imposed pressures sufficient to initiate the flow of tryptic soy broth through all defects. No significant differences were found for loss of sterility as a result of microbial ingress into test cells with microtube ID sizes of 5, 10, and 20 m between the test organisms (p > 0.05). Interactions between the initiation of liquid flow as a result of imposed pressures, and the sterility loss of test cells were significant (p < 0.05). / Ph. D.
43

Decis?es silviculturais para produ??o de ?rvores de eucalipto de grande porte / Silvicultural decisions for the production of large eucalypt trees

Alves, Petr?nio Henrique 28 March 2016 (has links)
Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-05-03T14:57:17Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) petronio_henrique_alves.pdf: 952268 bytes, checksum: c672a103f4c27e5369547a6558985c5d (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-05-17T12:03:12Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) petronio_henrique_alves.pdf: 952268 bytes, checksum: c672a103f4c27e5369547a6558985c5d (MD5) / Made available in DSpace on 2017-05-17T12:03:12Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) petronio_henrique_alves.pdf: 952268 bytes, checksum: c672a103f4c27e5369547a6558985c5d (MD5) Previous issue date: 2016 / Os objetivos deste trabalho foram avaliar a influ?ncia do desbaste e da fertiliza??o p?s-desbaste no crescimento de ?rvores de um povoamento clonal de eucalipto e comparar a idade t?cnica de desbaste (ITD), obtida atrav?s do M?todo dos Ingressos Percentuais, com a idade t?cnica de corte (ITC) de dois povoamentos de clones de eucalipto. Para o primeiro objetivo, os dados foram coletados em 30 parcelas permanentes, sendo 16 convencionais e 14 g?meas, em que foi analisado o efeito do desbaste (parcela convencional) e da fertiliza??o (parcela g?mea) sobre o crescimento das ?rvores. O desbaste foi realizado aos 81 meses, com intensidade de 20%, 35% e 50% de ?rea basal presente, eliminando os piores indiv?duos, e a fertiliza??o aplicada aos 99 meses. As vari?veis analisadas resultantes da totaliza??o dos dados das parcelas foram ?rea basal (B), di?metro m?dio (q), altura total m?dia (Ht) e volume total com casca (Vcc). A an?lise dos dados constituiu-se na compara??o do efeito de vari?veis em rela??o ? idade por meio de modelo de regress?o, e foi realizada aos 99 meses ap?s o desbaste e aos 81 meses ap?s a fertiliza??o. Para atender ao segundo objetivo, os dados foram coletados em 34 parcelas permanentes, instaladas em povoamentos com espa?amento de 3,0 x 2,5 metros, em dois s?tios diferentes. Essas parcelas foram medidas aos 24, 36, 48, 60 e 72 meses, durante o Invent?rio Florestal Continuo (IFC). O M?todo dos Ingressos Percentuais foi empregado para determinar a ?poca de realiza??o do primeiro desbaste. Para projetar as distribui??es diam?tricas, para idades superiores ? ?ltima medi??o, utilizou-se um modelo de distribui??o diam?trica, que consiste na recupera??o dos par?metros de uma fun??o de densidade de probabilidade (f.d.p) ao longo dos anos. Neste trabalho, adotou-se a fun??o Weibull, que foi ajustada pelo m?todo de m?xima verossimilhan?a. A partir das informa??es de n?mero de indiv?duos e valores estimados para os par?metros da fun??o Weibull, ? e ?, de ambas as distribui??es diam?tricas analisadas, calculou-se o ingresso percentual (IP) de ?rvores em classes de di?metro sucessivas ao longo do tempo. Para determinar a ITD, foi ajustado um modelo exponencial justaposto a um modelo linear simples. A ITC foi definida como o momento em que o incremento corrente ? igual ao incremento m?dio, sendo a produtividade volum?trica, ao longo do tempo, estimada pelo modelo de Clutter. O desbaste apresentou influ?ncia para as vari?veis ?rea basal, volume total com casca e di?metro m?dio, por?m n?o influenciou a altura total m?dia. A fertiliza??o realizada ap?s o desbaste n?o influenciou a produ??o das vari?veis analisadas. A idade t?cnica de desbaste de um povoamento de eucalipto localizado em um s?tio de maior capacidade produtiva ocorre antes, comparado com a idade de desbaste de um povoamento em um local de produtividade inferior. Esse mesmo comportamento ocorre para a idade t?cnica de corte. Para um mesmo s?tio, a idade t?cnica de desbaste ocorre ap?s a idade t?cnica de corte. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / The objectives of this work were to evaluate the influence of thinning and post-thinning fertilization on tree growth of a clonal eucalypt stand, and compare the thinning technical age (ITD), obtained by the Percentages Ingress Method, with the harvest technical age (ITC) of two clonal eucalypt stands. For the first objective, the data were collected in 30 permanent plots, 16 conventional and 14 twins, in which were analyzed the effect of thinning (conventional plot) and fertilization (twin plot) on tree growth. The thinning was carried out at 81 months, with intensity of 20%, 35% and 50% of present basal area, eliminating the worst individuals, and the fertilization applied at 99 months. The analyzed variables resulting from the summation of data from plots were basal area (B), quadratic diameter (q), mean total height (Ht) and total volume with bark (Vcc). The data analysis consisted in the comparison of variable effects, in relation to age, through regression model, and was held at 99 months after the thinning and 81 months after fertilization. To attend the second objective, the data were collected in 34 permanent plots, installed in stands with spacing of 3.0 x 2.5 meters, in two different sites. These plots were measured at 24, 36, 48, 60 and 72 months, during the Continuous Forest Inventory (IFC). The Percentages Ingress Method was employed to determine the epoch of realization of the first thinning. To project the diameter distributions for older ages after the last measurement, there was used a diameter distribution model, which consists in recovering the parameters of a probability density function (f.d.p) along the years. In this work, it was adopted the Weibull function, which was adjusted by the maximum likelihood method. From the information of number of individuals and estimated values for the parameters of the Weibull function, ? and ?, from both analyzed diameter distributions, it was calculated the percentage ingress (IP) of trees in successive diameter classes along the time. To determine the ITD it was adjusted an exponential model juxtaposed to a simple linear model. The ITC was defined as the moment that the current increment is equal to the average increment, in which the volumetric productivity along the time was estimated by Clutter model. The thinning presented influence for the variables basal area, total volume with bark and quadratic diameter, however did not affect the mean total height. The fertilization performed after thinning did not influence the production of the analyzed variables. The thinning technical age of an eucalypt stand located in a higher productive capacity site occurs earlier compared to the thinning age of a stand in a lower productivity site. This same behavior occurs for the harvest technical age. For the same site, the thinning technical age occurs after the harvest technical age.
44

Traffic Engineering with MPLS and QOS

Ikram, Imran January 2009 (has links)
In the modern era there exist applications that require very high resources and generate a tremendous amount of traffic so they require considerable amount of bandwidth and QOS to operate and perform correctly. MPLS is a new and a fast technology that offers much remuneration both in terms of providing trouble-free and efficient security together with the high speed of switching. MPLS not only guarantees quality of service of IP networks but in addition to provides scope for traffic engineering it offers many enhanced features of IP networks as it does not replace IP routing, but works along with existing and future routing technologies to provide high-speed data forwarding between label-switched routers (LSRs) together with QOS. Many network carriers are facing the problem of how to accommodate such ever-growing demands for bandwidth. And the static nature of current routing algorithms, such as OSPF or IS-IS, the situation is going even worse since the traffic is concentrated on the &quot;least cost&quot; paths which causes the congestion for some links while leaving other links lightly loaded. Therefore, MPLS traffic engineering is proposed and by taking advantage of MPLS, traffic engineering can route the packets through explicit paths to optimize network resource utilization and traffic performance. MPLS provides a robust quality of service control feature in the internet. MPLS class of service feature can work in accordance with other quality of service architectures for IP networks.
45

An Exploratory Study of Augmented Reality and Mobile Games Examining <i>Ingress</i> Player Motivation and Potential Educational Value

Straight, Ryan M. 25 August 2015 (has links)
No description available.
46

Stochastická analýza smykového porušování železobetonových nosníků / Stochastic analysis of shear failure of reinforced concrete beams

Kucek, Martin January 2017 (has links)
The diploma thesis is focused on a solution of the load reaction of the bridge construction from girders KA-73. Proposal methods of the nonlinear analysis by means of final elements on the stochastic and deterministic level are used for the solution of the load reaction. A simulation technique Latin Hypercube Sampling is used within the stochastic analysis. A material degradation in the form of the trussing corrosion is solved with the expected decrease of the construction lifetime. The conclusion of the thesis contains an evaluation of initial quantities of material parameters for the load reaction of the construction in the form of the sensitivity analysis.

Page generated in 0.0307 seconds