The existence of anchor ice in supercooled water can have a profound impact on the management of water resource infrastructures in cold regions. For example, it can raise a tailrace water level and cause significant losses in generation revenue. So far, there have been limited studies on anchor ice, therefore, many problems still exist and much more study is needed. In the present research, experimental and mathematical studies of anchor ice were carried out. Experiments were conducted in a counter-rotating flume, located in a cold room at the University of Manitoba. The experiments were mainly focused on anchor ice evolution around rocks and on gravel beds under different hydro-meteorological conditions. The results are compared to a mathematical model developed herein and some important parameters such as anchor ice porosity and frazil ice deposition coefficient are examined. The growth process of anchor ice was monitored by two CCD cameras. A digital processing program was developed to analyze anchor ice images and determine the growth rate of anchor ice. In addition, anchor ice density, an important factor when studying anchor ice, was estimated and the effect of air temperature, Froude number and Reynolds number is explored. By analyzing torque load signals from the counter-rotating flume, the variation of bed roughness with the growth of anchor ice is elucidated. The deposition coefficient of anchor ice growth was also determined from the experiments. A mathematical model was developed based on a two-stage method to simulate the process of frazil ice transportation and deposition. Both frazil ice attachment and heat transfer between the supercooled water and ice crystals are considered in the model. Four governing equations related to the distribution of velocity and frazil ice transportation and deposition inside and outside the roughness layers were built. A fourth-order Runge- Kutta numerical method was used and programmed in Matlab to solve the governing equations. The growth rate of anchor ice under different hydro-meteorological conditions can be simulated by this numerical model. The proposed experimental and mathematical studies of anchor ice are presented intuitively in this paper and the results from this study contribute to a better understanding of the anchor ice growth mechanism. This study will help to develop better management strategies to mitigate ice related complications associated with hydroelectric generating stations and other hydraulic structures in cold regions.

The development of Wireless Sensor Networks (WSNs) is enabled by the recent advances in wireless communication and sensing technologies. WSN have a wide range of scientific and commercial applications. In many applications the sensed data is useless if the location of the event is not associated with the data. Thus localization plays a substantial role in WSNs. Increased dependence on devices and sensed data presses for more efficient and accurate localization schemes. In many Internet of Things (IoT) deployments the area covered is large making it impossible to localize all devices and Sensor Networks (SNs) using single-hop localization techniques. A solution to this problem is to use a multi-hop localization technique to estimate devices' positions. In small areas SNs require at least three anchor nodes within their transmission range to estimate their location. Despite numerous existing localization techniques, the fundamental behavior of multi-hop localization is, as yet, not fully examined. Thus, we study the main characteristics of multi-hop localization and propose new solutions to enhance the performance of multi-hop localization techniques. We examine the assumptions in existing simulation models to build a more realistic simulation model, while studying and investigating the behavior of multi-hop localization techniques in large scale deployments before the actual deployment. We find that the introduced error follows the Gaussian distribution, but the estimated distance follows the Rayleigh distribution. We use the new simulation model to characterize the effect of hops on localization in both dense and sparse multi-hop deployments. We show that, contrary to common beliefs, in sparse deployments it is better to use long hops, while in dense deployments it is better to use short hops. Using short hops in dense deployments generates a large amount of traffic. Thus we propose a new solution which decreases and manages the overhead generated during the localization process. The proposed solution decreased the number of messages exchanged by almost 70% for DV-Distance and 55% for DV-Hop. Finally, we utilize mobile anchors instead of fixed anchors and propose a solution for the collinearity problem associated with the mobile anchor and use Kalman Filter (KF) to enhance the overall localization accuracy. Through simulation studies, we show that the scheme using a Kalman Filter decreases the estimation errors than using single direction by 31% and better than using weighted averages by 16% . As well, our new scheme overcomes the collinearity problem that appears from using mobile anchor nodes. / Thesis (Ph.D, Computing) -- Queen's University, 2014-04-30 01:53:55.817

The existence of anchor ice in supercooled water can have a profound impact on the management of water resource infrastructures in cold regions. For example, it can raise a tailrace water level and cause significant losses in generation revenue. So far, there have been limited studies on anchor ice, therefore, many problems still exist and much more study is needed. In the present research, experimental and mathematical studies of anchor ice were carried out. Experiments were conducted in a counter-rotating flume, located in a cold room at the University of Manitoba. The experiments were mainly focused on anchor ice evolution around rocks and on gravel beds under different hydro-meteorological conditions. The results are compared to a mathematical model developed herein and some important parameters such as anchor ice porosity and frazil ice deposition coefficient are examined. The growth process of anchor ice was monitored by two CCD cameras. A digital processing program was developed to analyze anchor ice images and determine the growth rate of anchor ice. In addition, anchor ice density, an important factor when studying anchor ice, was estimated and the effect of air temperature, Froude number and Reynolds number is explored. By analyzing torque load signals from the counter-rotating flume, the variation of bed roughness with the growth of anchor ice is elucidated. The deposition coefficient of anchor ice growth was also determined from the experiments. A mathematical model was developed based on a two-stage method to simulate the process of frazil ice transportation and deposition. Both frazil ice attachment and heat transfer between the supercooled water and ice crystals are considered in the model. Four governing equations related to the distribution of velocity and frazil ice transportation and deposition inside and outside the roughness layers were built. A fourth-order Runge- Kutta numerical method was used and programmed in Matlab to solve the governing equations. The growth rate of anchor ice under different hydro-meteorological conditions can be simulated by this numerical model. The proposed experimental and mathematical studies of anchor ice are presented intuitively in this paper and the results from this study contribute to a better understanding of the anchor ice growth mechanism. This study will help to develop better management strategies to mitigate ice related complications associated with hydroelectric generating stations and other hydraulic structures in cold regions.

In dynamic P2P networks, nodes join and depart from the system frequently, which partially damages the predefined P2P structure, and impairs the system performance such as basic lookup functionality. Therefore stabilization process has to be done to restore the logical topology. This paper presents an approach to relax the requirement on routing tables to provide provably better stability than fixed structured P2P systems. We propose a relaxed Chord that keeps the O(logN) number of hops for greedy lookup, but it requires less stabilization overhead. It allows a tradeoff between lookup efficiency and structure flexibility without adding any overhead to the system. In the relaxed routing structure, each routing entry ("finger") of the node is allowed to vary within a set of values. Each node only needs to keep a certain number of fingers that point to nodes in its anchor set. This relaxation reduces the burden of state management of the node. The relaxed routing scheme provides an alternative structure other than randomized P2P and deterministic P2P, by relaxing on finger selection. It provides good flexibility and therefore extends the system functioning time. / Singapore-MIT Alliance (SMA)

Submitted by THAYNÁ CRISTINA PARSANEZE IASI null (iasi_bob@hotmail.com) on 2018-04-02T22:08:10Z No. of bitstreams: 1 Thayná C. P. Iasi - Mestrado.pdf: 1856665 bytes, checksum: 1e364366bb33964d96f7f94ac51d39fd (MD5) / Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-04-03T11:57:09Z (GMT) No. of bitstreams: 1 iasi_tcp_me_rcla.pdf: 1628760 bytes, checksum: c369d0a3080f5a92e55e16e36f394378 (MD5) / Made available in DSpace on 2018-04-03T11:57:09Z (GMT). No. of bitstreams: 1 iasi_tcp_me_rcla.pdf: 1628760 bytes, checksum: c369d0a3080f5a92e55e16e36f394378 (MD5) Previous issue date: 2018-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Manter ou reestabelecer uma postura estável depende da detecção de informações por meio de sistemas sensoriais e sistemas de ação-percepção como o sistema háptico. O sistema háptico usa a exploração ativa inclusive durante o uso de ferramentas rígidas ou não rígidas para detectar propriedades importantes do ambiente. Um paradigma proposto sobre o papel do sistema háptico no controle da postura foi o sistema âncora. Os achados dos efeitos estabilizadores da postura com o uso do sistema âncora ilustram como o processo de detecção de informação do ambiente, distal ao corpo e mediado pela ferramenta âncora, depende da relação quase-estável no contato entre a superfície de apoio do corpo e a porção distal das âncoras. A extensão da utilidade desse contato distal para orientação postural ainda é pouco conhecida quanto ao contexto de perturbação da superfície. O objetivo do presente estudo foi investigar o papel da ancoragem realizada no próprio corpo, ou seja, com a porção distal em contato com quatro pontos corporais (i.e., cintura escapular, cintura, joelho e tornozelo), e verificar sua eficiência na redução da taxa de oscilação postural em contraste com a ancoragem tradicional (referência externa). Ainda, analisar a influência da localização desses pontos, distal ou proximal ao solo, quanto à função de ancoragem háptica. Para isso, foram testados 27 sujeitos ativos de ambos os sexos, que permaneceram imóveis em posição tandem sobre uma plataforma de força, com restrição da visão. As condições da tarefa de ancoragem incluíram: a ancoragem tradicional e ancoragem com conexão distal em contato com os quatro pontos corporais (cintura escapular, cintura, joelho e tornozelo). Foram analisadas as variáveis referentes à oscilação corporal (TT-CP, área da elipse, AMO-ML) e referentes à regulação da oscilação do centro de pressão (VM-ML). Os resultados obtidos demonstraram que a ancoragem nos pontos de contato corporal, via TT-CP e AMO-ML, reduziu a taxa de oscilação postural quando comparada à condição sem âncora. Entretanto, a âncora tradicional é mais eficiente do que quando a resistência vem da porção anexa em qualquer parte do corpo. Quando a comparação é feita entre os pontos de contato corporal, observamos que eles não diferem entre si. Concluímos que mesmo o contato de ancoragem no corpo sendo parcialmente eficiente na redução da taxa de oscilação corporal, este contexto não equipara aos níveis de redução de oscilação gerados por uma ancoragem com referência externa. / Maintaining or reestablishing a stable posture depends on the detection of information through sensory systems and action-perception systems such as the haptic system. The haptic system uses active exploration, even during the use of rigid and non-rigid tools used to detect important properties of the environment. A proposed paradigm about the role of the haptic system in posture control was the anchor system. The findings of the stabilizing effects of posture with the use of the anchor system demonstrate how the process of detecting information from the environment, distal to the body and mediated by the anchor tool, depends on the almost-stable relationship in the contact between body support surface and the distal portion of the anchors. The extent of the utility of this distal contact for postural orientation is still poorly known in the context of surface disturbance. The objective of the present study was to investigate the role of anchoring in own body, therefore, with the distal portion in contact with four corporal points (i.e., scapular waist, waist, knee and ankle), and verify the efficiency in reducing the rate of the postural oscillation in contrast to the traditional anchorage (external reference). Nevertheless, to analyze the influence of the location of these points, distal or proximal to the ground, regarding the function of haptic anchorage. For this, were tested 27 active subjects of both sexes, who remained immobile in a tandem position on a force platform, with visual restriction. The anchoring task conditions included: traditional anchorage and the anchorage with distal connection in contact with four body points (scapular waist, waist, knee, ankle). Were analyzed the variables related to body oscillation (TT-CP, ellipse area, OA-ML) and referring to regulation of the center of pressure oscillation (MD-ML). The results obtained showed that anchorage at the body contact points, via TT-CP and OA-ML, reduced the rate of postural oscillation when compared to non-anchor condition. However, the traditional anchor is more efficient than when the resistance comes from the attached portion in any part of the body When the comparison is made between the points of body contact, we observe that they do not differ from each other. We conclude that even the anchoring contact in the body being partially efficient in reducing the rate of body oscillation, this context does not equate to the levels of oscillation reduction generated by an anchorage with external reference.

The mining industry is a major consumer of rock bolts in the United States. Due to the high humidity in the underground mining environment, the rock bolts corrode and loose their load bearing capacity which in turn reduces the life expectancy of the ground support and, thus, creates operational difficulties and number of safety concerns [1]. Research on rock anchor corrosion has not been adequately extensive in the past and the effects of several factors in the mine atmosphere and waters are not clearly understood. One of the probable reasons for this lack of research may be attributed to the time required for gathering meaningful data that makes the study of corrosion quite challenging. In this particular work underground water samples from different mines in the Illinois coal basin were collected and the major chemical content was analyzed and used for the laboratory testing. The corrosion performance of the different commercial rock anchors was investigated by techniques such as laboratory immersion tests in five different corrosion chambers, and potentiodynamic polarization tests in simulated ground waters based on the Illinois coal basin. The experiments were conducted with simulate underground mining conditions (corrosive). The tensile strengths were measured for the selected rock anchors taken every 3 months from the salt spray corrosion chambers maintained at different pH values and temperatures. The corrosion potential (Ecorr), corrosion current (Icorr) and the corresponding corrosion rates (CR) of the selected commercial rock bolts: #5, #6, #6 epoxy coated and #7 forged head rebar steels, #6 and #7 threaded head rebar steels were measured at the solution pH values of 5 and 8 at room temperature. The open circuit potential (OCP) values of the different rock anchors were recorded in 3 selected underground coal mines (A, B & C) in the Illinois coal basin and the data compared with the laboratory electrochemical tests for analyzing the life of the rock anchors installed in the mines with respect to corrosion potential and corrosion current measured. The results of this research were statistically validated. This research will have direct consequence to the rock related safety. The results of this research indicate that certain corrosive conditions are commonly found in mines but uniform corrosion (around 0.01-0.03mm loss per year across the diameter) is generally not considered a serious issue. From this study, longer term research for long-term excavation support is recommended that could quantify the problem depending on the rock anchor used and specific strata conditions.

Submitted by Fernanda Lopes Magre (fe.magre@yahoo.com.br) on 2018-11-14T12:35:27Z No. of bitstreams: 1 DISSERTAÇÃO FERNANDA LOPES MAGRE.pdf: 2206914 bytes, checksum: 44c4deb4d10f6e4feb723b04f600bbf8 (MD5) / Rejected by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br), reason: Prezada Fernanda, O documento enviado para a coleção Campus Unesp Rio Claro foi recusado pelo(s) seguinte(s) motivo(s): - Página de rosto incompleta: falta o nome do orientador e cidade de defesa - informação obrigatória - Falta a folha de aprovação, que deve ser solicitada à Seção de Pós-Graduação e deve ser inserida após a ficha catalográfica. - Agradecimentos: A Portaria nº 206, de 04/09/2018 Dispõe sobre obrigatoriedade de citação da CAPES nos agradecimentos da seguinte forma: "Art. 3º Deverão ser usadas as seguintes expressões, no idioma do trabalho: "O presente trabalho foi realizado com apoio da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Código de Financiamento 001" Agradecemos a compreensão e aguardamos o envio do novo arquivo. Atenciosamente, Biblioteca Campus Rio Claro Repositório Institucional UNESP https://repositorio.unesp.br on 2018-11-14T16:23:25Z (GMT) / Submitted by Fernanda Lopes Magre (fe.magre@yahoo.com.br) on 2018-11-14T17:15:16Z No. of bitstreams: 1 REPOSITÓRIO FERNANDA LOPES MAGRE.pdf: 1903981 bytes, checksum: 84551fa2723407938a7c991dffabf379 (MD5) / Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-11-14T17:28:17Z (GMT) No. of bitstreams: 1 magre_fl_me_rcla.pdf: 1903981 bytes, checksum: 84551fa2723407938a7c991dffabf379 (MD5) / Made available in DSpace on 2018-11-14T17:28:17Z (GMT). No. of bitstreams: 1 magre_fl_me_rcla.pdf: 1903981 bytes, checksum: 84551fa2723407938a7c991dffabf379 (MD5) Previous issue date: 2018-09-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os sistemas sensoriais e motor trabalham de forma integrada para restabelecer o equilíbrio corporal durante a realização de outras tarefas (e.g., carregar uma bandeja com copos, trocar uma lâmpada enquanto equilibramos numa escada, etc.), as quais identificamos como “supra-posturais”. Ainda, indivíduos usam a percepção háptica para incorporar ferramentas na realização dessas tarefas que podem, concomitantemente, auxiliar no controle da postura. Uma ferramenta identificada como útil ao controle postural é o sistema âncora que consiste numa tarefa de manipular sutilmente cabos flexíveis anexos a cargas de reduzida massa que ficam em contato com o solo. Segurando a ponta desses cabos com as mãos, os indivíduos, via exploração ativa do sistema háptico, ajustam seu corpo no espaço mais eficientemente do que sem esta ferramenta. O objetivo desse estudo é analisar em tarefa de ancoragem háptica como componentes de tarefa supra-postural (i.e., deslocar o sistema âncora ritmicamente para cima e para baixo; com e sem contato com o solo e com e sem presença de cargas anexas ao sistema âncora) afetam os níveis de oscilação corporal em tarefas de equilíbrio. Participaram do estudo 15 adultos jovens que realizaram duas sessões de coleta em dias distintos (sessão de ancoragem com cargas e sessão de ancoragem sem cargas). Os participantes ficaram em pé sobre uma plataforma de força com os pés na posição tandem, vendados, durante 30 segundos, e, ao som de um metrônomo (55 BPM), levantaram e abaixaram ritmicamente o sistema âncora (i.e., com cargas anexas) ou cabos de nylon livres (i.e., sem cargas anexas) de acordo com as seguintes condições: ancoragem estática, ancoragem dinâmica em fase, ancoragem dinâmica fora de fase e ancoragem mista. As mesmas condições foram realizadas nas duas sessões de ancoragem. Para cada condição foram realizadas 2 tentativas. As variáveis do centro de pressão (COP) incluíram o comprimento total do COP (CT-COP), RMS do deslocamento médio-lateral (RMS-ml), velocidade média de oscilação médio-lateral (Velocidade-ml) e frequência com 80% da potência espectral na direção médio-lateral (F80-ml). Os resultados revelaram que um sistema de ancoragem sem cargas não promove efeitos estabilizadores na postura, o que não o caracteriza como uma tarefa predominantemente supra-postural. Ainda, manter as cargas em suspensão durante uma tarefa de ancoragem não promove efeitos estabilizadores na postura tal como ocorre ao manter as cargas em contato com o solo. Por fim, ancorar-se com cargas estáticas no solo promove efeitos estabilizadores para a postura melhores do que ancorar-se com cargas de forma dinâmica. Esses resultados demonstram a influência da informação sensorial para controlar a postura em um sistema de ancoragem háptica, que depende de uma referência fixa para orientação postural (i.e., cargas das âncoras em contato com uma superfície). / The sensory and motor systems work in an integrated way to reestablish balance while performing other motor tasks (e.g., carry a tray with cups, changing a light bulb while balancing on a ladder, etc.), which we identify as “supra-postural.” Moreover, individuals use haptic perception to control tools while performing these tasks that can, at the same time, aid the postural control system. A tool identified as useful to the postural function is the anchor system, which consists in subtle manipulation of flexible cables attached to low mass loads that are kept in contact with the ground. Holding these cables with their hands, individuals, via active exploration, adjust their bodies in space more efficiently than without this tool. The purpose of this study is to analyze in haptic anchorage tasks how does supra-postural components (e.g., intentionally move rhythmically the anchor system up and down; with or without anchor masses touching the ground, and with or without the end loads attached to the anchor system) affect body sway during balancing tasks. Fifteen young adults participated in this study in two sessions of data collection separated in two different days (anchors with loads and free-load anchors). The participants stood on a force platform with their feet in tandem position, blindfolded, for 30 seconds. To the sound of a metronome (55 BPM), they moved anchor system or the nylon strings (e.g., without the attached loads) up and down according to the following conditions: quiet anchoring, in-phase and out-of-phase dynamic anchoring, and mixed anchoring (e.g., one hand quiet anchoring while the other keep a dynamic anchoring). The variables of the center of pressure (COP) included the COP’s path length (PL-COP), ellipse area, RMS of medial-lateral displacement (RMS-ml), mean speed of medial-lateral oscillation (MSS-ml) and the frequency at 80% of the power spectrum (F80-ml). Our results revealed that an unloaded anchorage system does not provide stabilizing effects for the posture system and is not characterized as a supra-postural task, contrary to the anchor system with loads. Also, keeping the loads in suspension during an anchoring task does not stabilize posture as much as when keeping the loads in contact with the ground. Finally, anchoring with steady loads on the ground promotes stabilizing effects of the posture compared to dynamic anchoring with loads moving rhythmically. These results illustrate that sensory information to control posture during haptic anchoring tasks rely on a fixed reference for postural orientation (i.e., anchor loads in contact with a surface).

An important aspect of upcoming fifth-generation (5G) cellular communication systems is to improve the accuracy with which user equipments can be positioned. Accurately knowing the position of a user equipment is becoming increasingly important for a wide range of applications, such as automation in industry, drones, and the internet of things. Contrary to how existing techniques for outdoor cellular positioning deal with multipath propagation, in this study the aim is to use, rather than mitigate, the multipath propagation prevalent in dense urban environments. It is investigated whether it is possible to position a user equipment using only a single transmitting base station, by exploiting position-related information in multipath components inherent in the received signal. Two algorithms are developed: one classical point-estimation algorithm using a grid search to find the cost function-minimizing position, and one Bayesian filtering algorithm using a point-mass filter. Both algorithms make use of BEZT, a set of 3D propagation models developed by Ericsson Research, to predict propagation paths. A model of the signal received by a user equipment is formulated for use in the positioning algorithms. In addition to the signal model, the algorithms also require a digital map of the propagation environment. The algorithms are evaluated first on synthetic measurements, generated using BEZT, and then on real-world measurements. For both the synthetic and real-world measurement sets, the Bayesian point-mass filter outperforms the classical algorithm. It is observed how, given synthetic measurements, the algorithms yield better estimates in non-line-of-sight regions than in regions where the user equipment has line-of-sight to the transmitting base station. Unfortunately, these results do not generalize well to the real-world measurements, where, overall, neither algorithm is able to provide reliable and robust position estimates. However, as multipath-assisted positioning, to the best of our knowledge, has not been used for outdoor cellular positioning before, there are plenty of algorithm extensions, modifications, and problem aspects left to be studied - some of which are discussed in the concluding chapters.

The healthcare workforce throughout the world is experiencing a shortage of healthcare workers and various strategies, processes and programs exist today of which nursing manager’s use to not only recruit nursing staff, but to retain these scarce resources. This research aims specifically to examine how career anchors and job compatibility influences the levels of job satisfaction of professional nurses. This study measured career anchors and job satisfaction to determine whether those whose job type and career anchor matched reported higher satisfaction than those whose job type and career anchor did not match. Results suggested that significant differences exist between functional nurses and managerial nurses. Specifically, the nursing group placed importance on lifestyle and service/dedication to a cause, while the managerial group places importance on functional competence and lifestyle. Finally, results indicated that job type and career anchor compatibility on their own might not be adequate predictors of job satisfaction. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

This thesis deals with the issue of localization in wireless sensor networks. It focuses on the implementation Anchor-Free localization techniques to NS2 and evaluation of its effectiveness. In the theoretical introduction is summarized IEEE802.15.4 and ZigBee technology. The following chapter describes the Anchor-Based and Anchor-Free localization methods. Furthermore, existing methods of measuring the distance of network nodes are described. Also pay attention NS2 environment, especially the inclusion of standard IEEE802.15.4. The section devoted to Anchor-Free algorithm describes how to search and select anchor modes. It also described the method of optimization by measuring the distance of neighboring nodes using the Mass-Spring Algorithm. Next chapter describe the inclusion of a new protocol called AFLOCAL into NS2 and detailed analysis of its function. Next described the process of localization and calculating the coordinates. Described was aslo a method of simulation and evaluation of results. In conclusion, the results are summarized and formulated the characteristics of designed protocol AFLOCAL.