Spelling suggestions: "subject:"unstable"" "subject:"instable""
21 |
Subgroups of Adolescent Girls with Borderline Personality Disorder SymptomsSlavin-Stewart, Claire 11 1900 (has links)
This thesis examined the borderline personality disorder symptom profiles of teenage girls who were referred to a tertiary child and youth psychiatry clinic. Self-injury and unstable mood are key features of Borderline Personality Disorder (BPD) but are also associated with other disorders such as depression and anxiety disorders. The aim of the larger study was to determine whether BPD can be differentiated from other disorders in a highly comorbid adolescent sample who self-injure.
To answer this question, individuals in our sample were grouped based on the pattern of BPD symptom endorsement using a latent class analysis. The subgroups that emerged from our sample were then compared to each other across other clinical measures. Four latent classes were identified. The most impaired class had a high prevalence of BPD (70%). An intermediate class had a significantly higher prevalence of PTSD (41.7%). Another intermediate group had a higher prevalence of anxiety disorders (62%) (Social Phobia and Generalized Anxiety Disorder). The largest class had a low prevalence of all psychiatric disorders.
The results indicated that only a small subset of teenage girls who presented with self-injury and unstable mood met criteria for BPD. These girls represented a distinct and severely impaired group with high comorbidity. The subgroups that emerged from our sample provide guidance to clinicians regarding the likelihood of a personality disorder diagnosis in this population and the pattern of emotional difficulties of youth who self-injure. / Thesis / Master of Science (MSc)
|
22 |
Unstable Communities in Network EnsemblesRahman, Md Ahsanur 07 January 2016 (has links)
Ensembles of graphs arise naturally in many applications, for example, the temporal evolution of social contacts or computer communications, tissue-specific protein interaction networks, annual citation or co-authorship networks in a field, or a family of high-likelihood Bayesian networks inferred from systems biology data. Several techniques have been developed to analyze such ensembles. A canonical problem is that of computing communities that are persistent across the ensemble. This problem is usually formulated as one of computing dense subgraphs (communities) that are frequent, i.e., appear in many graphs in the ensemble.
In this thesis, we seek to find "unstable communities" which are the antithesis of frequent, dense subgraphs. Informally, an unstable community is a set of nodes that induces highly-varying subgraphs in the ensemble. In other words, the graphs in the ensemble disagree about the precise pairwise connections among these nodes. The primary contribution of this dissertation is to introduce the concept of unstable communities as a novel problem in the field of graph mining. Specifically, it presents three approaches to mathematically formulate the concept of unstable communities, devises algorithms for computing such communities in a given ensemble of networks, and shows the usefulness of this concept in a variety of settings.
Our first definition of unstable community relies on two parameters: the first ensures that a node set induces several different subgraphs in the ensemble and the second guarantees that each of these subgraphs occurs in a large number of graphs in the ensemble. We present two algorithms to enumerate unstable communities that match this definition. The first approach, ClustMiner, is a heuristic that transforms the problem into one of computing dense subgraphs in a single graph that summarizes the ensemble. The second approach, UCMiner, is guaranteed to enumerate all maximal unstable communities correctly. We apply both approaches to systems biology datasets to demonstrate that UCMiner is superior to ClustMiner in the sense that ClustMiner's output contains node sets that are not unstable while also missing several communities computed by UCMiner. We find several node sets that capture the uncertain connectivity of genes in relevant protein complexes, suggesting that further experiments may be required to precisely discern their interaction patterns.
Our second and third definitions of unstable community rely on a novel concept of (scaled) subgraph divergence, a formulation that uses the concept of relative entropy to measure the instability of a community. We propose another algorithm, SDMiner, that can exactly enumerate all maximal unstable communities with small (scaled) subgraph divergence. We perform extensive experiments on social network datasets to show that we can discover UCs that capture the main structural variations of the given set of networks and also provide us with interesting and relevant insights about these datasets. / Ph. D.
|
23 |
Iterative Rational Krylov Algorithm for Unstable Dynamical Systems and Genaralized Coprime FactorizationsSinani, Klajdi 08 January 2016 (has links)
Generally, large-scale dynamical systems pose tremendous computational difficulties when applied in numerical simulations. In order to overcome these challenges we use several model reduction techniques. For stable linear models these techniques work very well and provide good approximations for the full model. However, large-scale unstable systems arise in many applications. Many of the known model reduction methods are not very robust, or in some cases, may not even work if we are dealing with unstable systems. When approximating an unstable system by a reduced order model, accuracy is not the only concern. We also need to consider the structure of the reduced order model. Often, it is important that the number of unstable poles in the reduced system is the same as the number of unstable poles in the original system. The Iterative Rational Krylov Algorithm (IRKA) is a robust model reduction technique which is used to locally reduce stable linear dynamical systems optimally in the ℋ₂-norm. While we cannot guarantee that IRKA reduces an unstable model optimally, there are no numerical obstacles to the reduction of an unstable model via IRKA. In this thesis, we investigate IRKA's behavior when it is used to reduce unstable models. We also consider systems for which we cannot obtain a first order realization of the transfer function. We can use Realization-independent IRKA to obtain a reduced order model which does not preserve the structure of the original model. In this paper, we implement a structure preserving algorithm for systems with nonlinear frequency dependency. / Master of Science
|
24 |
Une description fonctorielle des K-théories de Morava des 2-groupes abéliens élémentaires / A functorial description of the Morava K-theories of elementary abelian 2-groupsNguyen, Le Chi Quyet 07 July 2017 (has links)
Le but de cette thèse est l'étude, d'un point de vue fonctoriel, des K-théories de Morava modulo 2 des 2-groupes abéliens élémentaires. Autrement dit, nous étudions les foncteurs covariants $V \mapsto K(n)^*(BV^{\sharp})$ pour le premier p=2 et n un entier positif.Le cas n=1, qui résulte directement du travail d'Atiyah sur la K-théorie topologique, nous donne un foncteur coanalytique qui ne possède aucun sous-foncteur polynomial non-constant. Il est très différent du cas n>1, où les foncteurs mentionnés ci-dessus s'avèrent être analytiques.La théorie de Henn-Lannes-Schwartz fournit une correspondance entre les foncteurs analytiques et les modules instables sur l'algèbre de Steenrod. Nous déterminons le module instable correspondant au foncteur analytique $V \mapsto K(2)^*(BV^{\sharp})$, en étudiant la relation entre ce foncteur et la structure d'anneau de Hopf de l'homologie de l'omega-spectre associé à la théorie K(2). / The aim of this PhD thesis is to study, from a functorial point of view, the mod 2 Morava K-theories of elementary abelian 2-groups. Namely, we study the covariant functors $V \mapsto K(n)^*(BV^{\sharp})$ for the prime p=2 and n a positive integer.The case n=1, which follows directly from the work of Atiyah on topological K-theory, gives us a coanalytic functor which contains no non-constant polynomial sub-functor. This is very different from the case n>1, where the above-mentioned functors are analytic.The theory of Henn-Lannes-Schwartz provides a correspondence between analytic functors and unstable modules over the Steenrod algebra. We determine the unstable module corresponding to the analytic functor $V \mapsto K(2)^*(BV^{\sharp})$, by studying the relation between this functor and the Hopf ring structure of the homology of the omega-spectrum associated to the theory K(2).
|
25 |
Faktorer som bidrar till ett stabilare mående hos patienter med emotionellt instabil personlighetsstörning i heldygnsvård : en kvalitativ intervjustudie ur ett patientperspektiv / Factors that contribute to a more stable mood in patients with emotionally unstable personality disorder in inpatient care : a qualitative interview study from a patient perspectiveCarlsson, Anna, Andersson, Linda January 2016 (has links)
Bakgrund: Patienter med emotionell instabil personlighetsstörning upplevs som en svårbehandlad patientgrupp inom heldygnsvården. Omvårdnadspersonalens kunskap kring bemötande och behandling av denna patientgrupp är varierande vilket gör att vården ser olika ut. Detta kan resultera i ett ökat lidande hos patienten och frustration i personalgruppen. Syfte: Studiens syfte var att beskriva faktorer som bidrar till stabilare mående hos patienter med emotionellt instabilt personlighetsstörning under heldygnsvård. Metod: Som metod har använts en kvalitativ design med induktiv ansats. Studien baserades på sex intervjuer där informanterna var patienter med diagnosen emotionellt instabil personlighetsstörning. Intervjuerna analyserades med hjälp av kvalitativ innehållsanalys. Resultat: Resultatet visade att bemötandet och engagemang hos personal var av stor vikt. Struktur och delaktighet var andra viktiga faktorer för att nå ett stabilare mående. Det framkom att heldygnsvården kunde bidra med ett avbrott i vardagen och att meningsfulla aktiviteter under vårdtiden var en annan viktig faktor. Slutsats: Patienterna upplevde att bli bemött som en individ av engagerad personal och att få vara delaktig i sin vård som två viktiga faktorer i processen mot ett stabilare mående. Heldygnsvårdens struktur och miljöombytet stod för återhämtning och en möjlighet att återfå rutiner. Det framkom även en önskan om fler meningsfulla aktiviteter såsom fysisk aktivitet och psykoedukation för att på bästa sätt ta tillvara på vårdtiden. / Background: Patients with emotional unstable personality disorder is experienced as a difficult to treat patient population in inpatient care. Nursing staff knowledge surrounding the introduction and the treatment of this patient population is diverse, which means that the care is different. This can result in increased suffering of the patient and frustration in the staff group. Aim: The aim of the study was to describe factors that contribute to a more stable mood in patients with emotionally unstable personality disorder. Method: The method that has been used is a qualitative design with inductive approach. The study was based on six interviews with informants that who were patients diagnosed with emotionally unstable personality disorder. The interviews were analyzed using content analysis. Result: The results showed that the hospitality and commitment of the staff was of great importance. Structure and participation were other important factors for achieving a stable mood. It was revealed that inpatient care could contribute to an interruption of everyday life and meaningful activities were another important factor that emerged. Conclusion: Patients experienced to be treated as an individual by committed staff and to be involved in their care was part of the process towards a stable mood. Inpatient care structure and change of environment support for recovery and an opportunity to regain routines. There was a desire for more meaningful activities such as physical activity and psycho education to best take advantage of the period of care
|
26 |
Reliable computation of invariant dynamics for conservative discrete dynamical systemsJames, Jason Desmond 25 August 2010 (has links)
Computing reliable numerical approximations of invariant
sets for nonlinear systems is the core problem for computer assisted
study of dynamical systems. In the case of conservative systems the
problem is complicated by the fact that there is no phase space
dissipation to drive orbits onto attractors. In this dissertation we
discuss several contributions to the field of computer assisted
study of invariant dynamics in conservative systems. / text
|
27 |
Efekt fitness konceptu FLOWIN® na rovnováhu a spinální segmentální stabilizaci / Effect of fitness concept FLOWIN® on balance and spinal segmental stabilisationMrázková, Tereza January 2017 (has links)
Title: Effect of fitness concept FLOWIN® on balance and spinal segmental stabilisation Objectives: The goal of this thesis is to find out whether exercising the fitness concept FLOWIN® has any real and measurable effect on balance and spinal segmental stabilization of the individual, based on the comparison of measured data of exercisers of different levels of profficiency, which is differentiated by the length of exercise (beginners, advanced) and instructors of group lessons operating in the Czech Republic. Methods: The study in nature was a blinded experiment, attended by 13 beginners, 19 advanced exercisers and 10 instructors of the fitness concept FLOWIN®. Each participant's balance was tested by using the Y Balance test on lower and upper body and testing of spinal segmental stabilization was performed by using tests based on the principles of Australian method. The average results of testing of balance and spinal segmental stabilization of the experimental groups were then compared with each other. Separately were evaluated results of measuring spinal segmental stabilization in the group of instructors, depending on their experience in practicing the concept. Results: In the case of testing balance, the resulting research data showed that after comparing the average values of individual...
|
28 |
Escore de risco Dante Pazzanese para síndrome coronária aguda sem supradesnivelamento do segmento ST / Dante Pazzanese risk score for non-ST-segment elevation acute coronary syndromeSantos, Elizabete Silva dos 31 July 2008 (has links)
INTRODUÇÃO: As doenças cardiovasculares representam uma importante causa de morte mundial. Geralmente, são a primeira causa, não só em países desenvolvidos, como também em desenvolvimento. Pacientes com Síndrome Coronária Aguda (SCA) sem supradesnivelamento do segmento ST (SST) apresentam ampla variação do risco para ocorrência de óbito ou eventos isquêmicos recorrentes. Determinar o risco da ocorrência desses eventos adversos é importante para a triagem inicial na seção de emergência, assim como para identificar os que se beneficiam de condutas mais agressivas, dispendiosas e de maior morbidade e mortalidade. OBJETIVO: Realizar um modelo simples de estratificação de risco, facilmente aplicável no Departamento de Emergência, em uma população brasileira não selecionada de ensaios clínicos com o uso de variáveis clínicas, eletrocardiográficas, bioquímicas e biomarcadores plasmáticos. CASUÍSTICA E MÉTODOS: É um estudo prospectivo de pacientes com SCA sem SST recrutados de 1 de julho de 2004 a 31 de outubro de 2006. Foram submetidos a seguimento de 14 e 30 dias para análise do desfecho de morte por todas as causas, infarto (re-infarto) e revascularização miocárdica urgente por isquemia recorrente e de 180 dias para o desfecho de morte por todas as causas. Excluíram-se os pacientes com bloqueios de ramo, ritmo de marcapasso, ritmo de fibrilação atrial e os com episódio isquêmico secundário a causas não cardíacas. Para o modelo de desenvolvimento, optou-se pelo desfecho de morte por todas as causas ou infarto (re-infarto) em até 30 dias. Dados da história clínica, exame físico, eletrocardiograma da admissão, hemograma, bioquímica e biomarcadores plasmáticos foram selecionados para uma análise exploratória. As variáveis que apresentassem nível de significância menor que 10% na análise exploratória ou que fossem consideradas de relevância clínica, foram submetidas a um modelo de regressão logística múltipla. RESULTADOS: A população de desenvolvimento foi de 1.027 pacientes, sendo 589 homens (57,4%) e média de idade de 61,55 anos (± 0,35). O desfecho combinado de morte ou infarto (re-infarto) em 30 dias ocorreu em 54 pacientes (5,3%). Em decorrência do fenômeno de multicolinearidade entre a depressão do segmento ST e a troponina I cardíaca, estas variáveis foram combinadas. Foram identificadas sete variáveis prognósticas: idade em anos; antecedentes pessoais de diabete melito ou acidente vascular cerebral; não uso de inibidor da enzima conversora da angiotensina; combinação de elevação da troponina I cardíaca e depressão do segmento ST; creatinina sérica. O C statistic para o modelo de desenvolvimento foi de 0,78 e para o Escore de Risco Dante Pazzanese foi de 0,74. CONCLUSÃO: Em pacientes com SCA sem SST, o Escore de Risco Dante Pazzanese mostrou-se de fácil execução, com alto valor preditivo para eventos cardiovasculares em 30 dias de evolução, orientando o prognóstico e o tratamento desses pacientes. Pode ser fonte de informações à equipe médica, ao paciente e a seus familiares, englobando importante informação prognóstica. / BACKGROUND: Cardiovascular diseases are usually the leading cause of death in both developed and developing countries. Patients with non-ST-segment elevation (NSTE) acute coronary syndrome (ACS) are at varying degrees of risk for death and recurrent ischemic events. It is important that the risk for these adverse events be determined for the initial screening at the emergency department, as well as for identifying patients who may benefit from treatment options that are more aggressive, expensive and associated with higher morbidity and mortality. OBJECTIVE: To develop a simple risk-stratification model, easily performed in the Emergency Department setting, based on a non-selected Brazilian sample of clinical trials using clinical, electrocardiographic, and biochemical variables, as well as plasma biomarkers. PATIENTS AND METHODS: This is a prospective study of patients with NSTE-ACS recruited from July 1 2004 to October 31 2006. Patients were followed up for 14 and 30 days to assess the endpoints of all-cause mortality, infarction (reinfarction), and urgent myocardial revascularization due to recurrent ischemia, and for 180 days to assess all-cause mortality. Patients with bundle branch blocks, pacemaker rhythm, or atrial fibrillation were excluded from the study, as were those with ischemic episodes of non-cardiac causes. For the model under development the endpoint chosen was all-cause mortality or infarction (reinfarction) up to 30 days. Data on clinical history, physical examination, admission electrocardiogram, blood cell count, biochemistry, and plasma biomarkers were selected for an exploratory analysis. Variables with a significance level of less than 10% on the exploratory analysis or considered clinically relevant were included in a multiple logistic regression model. RESULTS: The study population included 1027 patients, of which 589 were men (57.4%). Mean age was 61.55 (± 0.35). Fifty-four patients (5.3%) reached the endpoints of death and/or infarction (reinfarction) within 30 days. Due to the multicolinearity phenomenon between ST-segment depression and cardiac troponin I, these variables were combined. Seven prognostic variables were identified, namely, age in years, past history of diabetes mellitus or stroke, nonuse of angiotensin-converting enzyme inhibitors, increased cardiac troponin I levels combined with ST-segment depression; and serum creatinine. The C-statistic for the model was 0.78, and for the Dante Pazzanese Risk Score was 0.74. CONCLUSION: In non-ST-segment elevation ACS patients, the Dante Pazzanese Risk Score proved to be easy to perform, with a high predictive value for cardiovascular events at 30 days, guiding prognosis and treatment of these patients. It may be a source of information for the medical team, the patients and their families, including important prognostic data.
|
29 |
Predicting regenerative chatter in turning using operational modal analysisKim, Sooyong 23 April 2019 (has links)
Chatter, unstable vibration during machining, damages the tool and workpiece. A proper selection of spindle speed and depth of cut are required to prevent chatter during machining. Such proper cutting conditions are usually determined using vibration models of the machining process.
Nonetheless, uncertainties in modeling or changes in dynamics during the machining operations can lead to unstable machining vibrations, and chatter may arise even when stable cutting conditions are used in the process planning stage. As a result, online chatter monitoring systems are key to ensuring chatter-free machining operations. Although various chatter monitoring systems are described in the literature, most of the existing methods are suitable for detecting chatter after vibrations become unstable. In order to prevent poor surface finish resulting from chatter marks during the finishing stages of machining, a new monitoring system that is capable of predicting the occurrence of chatter while vibrations are still stable is required.
In this thesis, a new approach for predicting the loss of stability during stable turning operations is developed. The new method is based on the identification of the dynamics of self-excited vibrations during turning operations using Operational Modal Analysis (OMA). The numerical simulations and experimental results presented in this thesis confirm the possibility of using Operational Modal Analysis as an online chatter prediction method during stable machining operations. / Graduate
|
30 |
O efeito do nível de dificuldade do adversário nas respostas hormonais e comportamentais, no desempenho técnico e no desempenho percebido de jovens jogadores de basquetebol. / The effect of the opponent difficulty level on hormonal and behavioral responses, technical performance and perceived performance in young basketball playersArruda, Ademir Felipe Schultz de 27 August 2018 (has links)
O objetivo da presente tese foi investigar o efeito do nível de dificuldade do adversário nas respostas hormonais, comportamentais e de desempenho de jovens jogadores de basquetebol. Para tanto, 29 atletas de basquetebol do sexo masculino, das categorias sub-15, sub-16 e sub-17 de um mesmo clube (15,3 ± 1,1 anos; 85,5 ± 15,0 kg; 189,0 ± 7,9 cm) foram avaliados na primeira fase do Campeonato Paulista em três partidas com diferentes níveis de dificuldade do adversário (Difícil, Médio e Fácil) para cada uma das três categorias, somando um total de nove partidas. As concentrações salivares de cortisol (C) e testosterona (T) pré e pós-partida, a ansiedade pré-competitiva, o desempenho técnico através do número de envolvimentos técnico-táticos com bola de cada jogador, a percepção subjetiva de esforço da sessão (PSE da sessão) e o desempenho percebido, foram consideradas em cada partida. A comparação de T e C, e o desempenho técnico foi realizada com uma análise de modelos mistos de um (nível de dificuldade) ou dois fatores (nível de dificuldade e momento), com medidas repetidas. Por sua vez, a comparação das variáveis ansiedade pré-competitiva, PSE da sessão e desempenho percebido foi realizada pelo teste de Friedman, seguido do teste de Wilcoxon, quando necessário. Em ambas as análises foi utilizado o post hoc de Bonferroni. Além disso, a associação entre as repostas normalizadas pelo score Z da variação de T com o desempenho percebido e técnico foi verificada por meio da correlação de Pearson. Em todas as análises foi adotado o nível de significância de 5%. Foi verificado aumento de T do pré para o pós nas partidas contra adversários de nível de dificuldade Fácil (p = 0,0064) e Médio (p = 0,0375). A C pós-partida foi superior aos valores pré (p < 0,0001), independentemente do nível de dificuldade; e C no nível Fácil foi inferior ao nível Médio (p = 0,0351) e Difícil (p = 0,0035). A ansiedade cognitiva foi maior no nível Difícil em relação ao nível Fácil (p < 0.01). A ansiedade somática, por sua vez, foi maior no nível Difícil em relação aos níveis Fácil (p<0,001) e Médio (p = 0,01), e maior no nível Médio em relação ao nível Fácil (p = 0,004). A PSE da sessão foi maior no nível Difícil em relação aos níveis Fácil (p = 0,003) e Médio (p = 0,003). Não foi observado efeito do nível de dificuldade para autoconfiança (p = 0,118), desempenho técnico (p = 0,728) e desempenho percebido (p = 0,113). Além disso, não foi verificada correlação significante entre as variáveis desempenho técnico e percebido com a variação da concentração de T (r < 0,35 e p > 0,07 para todas as comparações). Os resultados da presente tese indicam que quanto maior o nível de dificuldade do adversário maior a ansiedade pré-competitiva e a PSE da sessão. A concentração de C aumentou independente do nível do adversário. Já a T aumentou nos jogos de menor dificuldade, mas não no jogo Difícil. Esse aumento da T não se correlacionou significativamente com o desempenho técnico ou percebido. Não houve influência do nível do adversário no desempenho técnico ou percebido / The aim of this thesis was to investigate the effect of the adversary difficulty level on hormonal and behavioral responses, technical performance and perceived performance in young basketball players. Thereunto, 29 male young basketball players, from under-15, under-16 and under-17 categories from the same club (15.3 ± 1.1 years, 85.5 ± 15.0 kg, 189.0 ± 7.9 cm) were evaluated in the first phase of the Paulista Championship in three matches with different opponent difficulty levels (Hard, Medium and Easy) for each of the three categories, totaling nine matches. Salivary concentrations of cortisol (C) and testosterone (T) pre and post-match, pre-competitive anxiety, technical performance through individual technical-tactical ball involvements, session rating of perceived exertion (session-RPE) and perceived performance were considered in each match. The comparisons of T and C, and technical performance were performed with a mixed model analysis with one (difficulty level) or two factors (difficulty level and moment), with repeated measures. On the other hand, the comparisons of pre-competitive anxiety, session-RPE and perceived performance were performed by the Friedman test, followed by the Wilcoxon test, when it was necessary. In both analyses, Bonferroni post hoc was used. Moreover, the association between the responses normalized by the Z score of T variation with the perceived and technical performance was verified through the Pearson correlation. A significance level of 5% was adopted for all analyzes. It was verified an increase in T from pre- to post-match against Easy (p = 0,0064) and Medium (p = 0,0375) opponent levels. C level increased from pre- to post-match, regardless of the difficulty level; and C in the Easy level was lower than the Medium (p = 0.0351) and Hard (p = 0.0035) difficulty levels. Cognitive anxiety was higher in the Hard level compared to the Easy one (p <0.01). Somatic anxiety, on the other hand, was higher in the Hard level compared to the Easy (p <0.001) and Medium (p = 0.01) levels and was higher in the Medium level compared to the Easy one (p = 0.004). Session-RPE was higher in the Hard level compared to the Easy (p = 0.003) and Medium (p = 0.003) levels. No effect of difficulty level for self-confidence (p = 0.118), technical performance (p = 0.728) and perceived performance (p = 0.113) was observed. In addition, no significant correlation was observed between the technical and perceived performance with T variation (r <0.35 and p> 0.07 for all comparisons). The results of this thesis indicate that the higher the opponent difficulty level, the greater the pre-competitive anxiety and the session-RPE. C increased independently of the opponent level. T increased in less difficult matches, but not in the Hard one. This increase in T did not correlate significantly with the technical or perceived performance. There was no influence of the opponent\'s level on technical or perceived performance
|
Page generated in 0.0445 seconds