L'objectif de cette thèse était d'une part la caractérisation des muscles respiratoires lors d'un effort incrémental jusqu'à l'épuisement et d'autre part, l'étude des effets de l'entraînement et de désentraînement spécifique des muscles inspiratoires. La première étude a confirmé le développement de la fatigue musculaire respiratoire lors d'un exercice incrémental maximal. À travers l'enregistrement de l'oxygénation au niveau du 7ème espace intercostal, la deuxième étude a montré la réduction de la désoxygénation des intercostaux et de la fatigue des muscles inspiratoires avec un exercice inspiratoire antérieur. Ensuite, nous avons montré que 5 semaines d'entraînement spécifique des muscles inspiratoires (IMT) que ce soit à haute ou à basse intensité réduit la fatigue musculaire respiratoire induite par l'exercice incrémental maximal. Cette réduction corrobore la diminution parallèle observée dans l'utilisation de l'O2 au niveau des muscles intercostaux et donc de leurs demandes métaboliques en lien avec la diminution de leur fatigabilité (Études 3 et 4). Ceci pourrait refléter une augmentation de l'apport d'oxygène au niveau des muscles locomoteurs. Ces améliorations étaient plus importantes avec l'IMT à haute résistance. Néanmoins, ces phénomènes adaptatifs gagnés à l'IMT étaient perdus après 10 semaines de désentraînement (Étude 5). Toutefois, la réduction de la fréquence d'IMT à deux séances par semaine tout en préservant la même charge résistive était suffisante pour maintenir les adaptations déjà obtenues. Les travaux de cette thèse ont donc mis en évidence l'implication des muscles respiratoires dans la limitation de l'effort incrémental jusqu'à l'épuisement et ont contribué à mieux comprendre les mécanismes explicatifs de l'amélioration de la performance après l'IMT et en particulier la fatigue et l'oxygénation musculaire respiratoire / The aim of thesis was on one hand to characterize the respiratory muscles during an incremental effort until exhaustion and on the other hand, to study the effects of specific inspiratory muscle training and detraining. We first confirmed the development of respiratory muscle fatigue during a maximal incremental exercise. Through recording of oxygenation at the 7th intercostal space, the second study showed reduced intercostal muscle deoxygenation and inspiratory muscle fatigue with a prior inspiratory exercise. Then, we showed that 5 weeks of specific inspiratory muscle training (IMT), whether at high or low intensity, reduces respiratory muscle fatigue induced by maximal incremental exercise. This reduction corroborates the parallel decrease observed in the intercostal muscle oxygen utilization and therefore in their metabolic demands in relation to their fatigability decrease (Study 3 and 4). This may reflect an increase in the oxygen supply of the locomotor muscles. These improvements were greater with high-resistance IMT. However, the IMT induced adaptations were lost after 10 weeks of detraining (Study 5). Nevertheless, reducing training frequency by up to two sessions per week while preserving the same training load was sufficient to maintain the already achieved adaptations. These results highlighted the respiratory muscle implication in the limitation of incremental effort until exhaustion and have contributed to a better understanding of the mechanisms underlying the improvement of performance after IMT particularly respiratory muscle oxygenation and fatigue

Thesis (M.A.)--The University of North Carolina at Greensboro, 2010. / Directed by Jerry Vaughan; submitted to the Dept. of Mathematics and Statistics. Title from PDF t.p. (viewed Jul. 14, 2010). Non-Latin script record Includes bibliographical references (p. 30).

A graph G is maximal nontraceable (MNT) (maximal nonhamiltonian (MNH)) if G is not traceable (hamiltonian), i.e. does not contain a hamiltonian path (cycle), but G+xy is traceable (hamiltonian) for all nonadjacent vertices x and y in G. A graph G is hypohamiltonian if G is not hamiltonian, but every vertex deleted subgraph G -u of G is hamiltonian. A graph which is maximal nonhamiltonian and hypohamiltonian is called maximal hypohamiltonian (MHH). Until recently, not much has appeared in the literature about MNT graphs, although there is an extensive literature on MNH graphs. In 1998 Zelinka constructed two classes of MNT graphs and made the conjecture, which he later retracted, that every MNT graph belongs to one of these classes. We show that there are many different types of MNT graphs that cannot be constructed by Zelinka's methods. Although we have not been able to characterize MNT graphs in general, our attempt at characterizing MNT graphs with a specified number of blocks and cut-vertices enabled us to construct infinite families of non-Zelinka MNT graphs which have either two or three blocks. We consider MNT graphs with toughness less than one, obtaining results leading to interesting constructions of MNT graphs, some based on MHH graphs. One result led us to discover a non-Zelinka MNT graph of smallest order, namely of order 8. We also present examples of MNTgraphs with toughness at least one, including an infinite family of 2-connected, claw-free graphs. We find a lower bound for the size of 2-connected MNT graphs of order n. We construct an infinite family of 2-connected cubic MNT graphs of order n, using MHH graphs as building blocks. We thus find the minimum size of 2-connected MNT graphs for infinitely many values of n. We also present a construction, based on MHH graphs, of an infinite family of MNT graphs that are almost cubic. We establish the minimum size of MNT graphs of order n, for all except 26 values of n, and we present a table of MNT graphs of possible smallest size for the excluded 26 values of n. / Mathematical Sciences / PHD (MATHEMATICS)

This thesis considers problems concerning Latin squares and sets of mutually quasiorthogonal Latin squares (MQOLS). We show how MQOLS are related to a number of other designs and establish bounds on Nq(n), the maximum number of Latin squares of order n in a mutually quasi-orthogonal set. We report the number of quasi-complete mappings admitted by each group of order 15 or less, and explain the surprising result that each of the non-cyclic groups of order 8 possesses exactly 384 complete mappings. For each group G of order 15 or less, we identify the sizes of all maximal sets of mutually orthogonal orthomorphisms. We also identify a number of new maximal sets for larger groups. We present a method to determine all proper, maximal sets of MQOLS of order n and carry this out for n < 6. Also we present a search for 3 MQOLS of order 10, which, whilst not identifying such a set, led to the identification of all resolutions of each (10,3, 2)-balanced incomplete block design. We give a construction for MQOLS based on groups, and use this to determine new sets of 2n - 1 MQOLS of order 2n based on two infinite classes of group. Existence results for MQOLS based on groups are also extended. Two constructions for (n x n)/k semi-Latin squares are given, one of which provides some new A-, D- and E-optimal examples with k > n which out-perform the existing A-, D- and E-optimal examples in the E'-criteria. Finally we consider the problem of determining invertible directed terraces of each non-abelian group of order < 21, and in so doing construct the first doubly balanced bipartite tournament of odd order.

Spatial facility location problems (SFLPs) involve the placement of facilities in continuous demand regions. One approach to solving SFLPs is to aggregate demand into discrete points, and then solve the point-based model as a conventional facility location problem (FLP) according to a surrogate model. Solution performance is measured in terms of the percentage of continuous space actually covered in the original SFLP. In this dissertation I explore this approach and examine factors contributing to solution quality. Three error sources are discussed: point representation spacing, multiple possible solutions to the surrogate point-based model, and round-off errors induced by the computer representation of numbers. Some factors—including boundary region surrogate points and surrogate point location—were also found to make significant contributions to coverage errors. A surrogate error measure using a point-based surrogate model was derived to characterize relationships among spacing, facility coverage area, and spatial coverage error. Locating continuous space facilities with full coverage is important but challenging. Demand surrogate points were initially used as a continuous space for constructing the MIP model, and a point-based surrogate FLP was enhanced for extracting multiple solutions with additional constraints that were found to reduce coverage error. Next, a best initial solution was applied to a proposed heuristic algorithm to serve as an improvement procedure. Algorithm performance was evaluated and applied to a problem involving the location of emergency warning sirens in the city of Dublin, Ohio. The effectiveness of the proposed method for solving this and other facility location/network design problems was demonstrated by comparing the results with those reported in recently published papers.

Clustering applications dealing with perception based or biased data lead to models with non-disjunct clusters. There, objects to be clustered are allowed to belong to several clusters at the same time which results in a fuzzy clustering. It can be shown that this is equivalent to searching all maximal cliques in dynamic graphs like G_t=(V,E_t), where E_(t-1) in E_t, t=1,... ,T; E_0=(). In this article algorithms are provided to track all maximal cliques in a fully dynamic graph. It is naturally to raise the question about the maximum clique, having all maximal cliques. Therefore this article discusses potentials and drawbacks for this problem as well. (author's abstract) / Series: Working Papers on Information Systems, Information Business and Operations

Guo Xiuyun. / "May 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 103-108) and index. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

We study the computational complexity of collecting items inside a grid map with obstacles, using an agent that always slides to the maximal extend, until it is stopped by an obstacle. An agent could be, for example, a robot or a vehicle, while obstacles could be walls or other immovable objects, and items could be packages that need to be picked up. This problem has very natural applications in robotics. The restricted type of motion of the agent naturally models movement on a frictionless surface, and movement of a robot with limited sensing capabilities and thus limited localization. For example, if a robot cannot determine the distance traveled once it starts moving, then it makes sense to keep moving until an obstacle is reached, even if the robot has a map of the environment. With today’s technology it is possible to create sophisticated robots but, since the complexity and the costs of such robots are high, it is sometimes better to use simple inexpensive robots that can still solve relatively complex tasks. In fact, simple robots are quite common and usually built using simple sensors that have limited capabilities, but that are easy to use and are considerably cheaper than more sophisticated ones. The computational complexity of numerous problems with movable objects has been extensively studied before. However, only a few of them have maximal sliding agents, and they usually do not have the goal of collecting items. We show that the problem of deciding if all the items can be collected by a maximal sliding agent can be solved efficiently when the agent is the only moving object in the map. However, we show that optimization problems such as determining the minimum number of moves required to collect all the items, and also variants in more complex environments are computationally intractable. Hence, for those problems it is better to focus on using heuristics than on finding optimal solutions.

This report presents a comprehensive review of efficacy studies for minimal contrasts therapy and maximal oppositions therapy. The target population was defined as children with phonological disorders who had no co-occurring impairments in hearing, receptive language, speech articulation, or oral-motor structure and function. Thirty three minimal contrasts studies from 1981 to 2008 and six maximal oppositions studies from 1990 to 2008 were identified. No studies from 2009 to 2012 were found. The majority of the studies were either Level III (descriptive studies, 34.2%) or Level IIb (quasi-experimental studies, 57.9%). Twenty three studies reported treatment duration, which ranged from six to 58 hours. Based on reports of treatment success and generalization to new linguistic and communicative contexts, it was found that minimal contrasts therapy has greater support in the literature. Additional studies using a uniform methodology will be needed to establish the validity of maximal oppositions therapy. Recommendations are made for future studies of minimal contrasts and maximal oppositions. / text

The present study examined the hemodynamic response to recreational hockey (n= 22) in middle-aged men (53±6 yrs). Study participants were equipped with ambulatory blood pressure and heart rate monitoring equipment prior to a weekly hockey games. Participants were monitored throughout the duration of their hockey game for “On-Ice” responses and during seated bench time (“Bench”), and for a brief period afterwards. On-Ice HR’s and blood pressures were significantly higher than values obtained during maximal cycle exercise (HR 174±8.9 vs. 163±11.0 bpm) (SBP 17%; DBP 15%) (p<0.05), Blood pressures decreased throughout the duration of the game while HR increased significantly. The On-Ice endocardial viability ratio (EVR), an index of myocardial oxygen supply and demand, did not change from early (1.56±0.05) to late (1.44± 0.06) in the game. In conclusion, recreational hockey is an extremely vigorous form of interval exercise that produces cardiovascular responses exceeding intensities commonly recommended for continuous training.