This dissertation discusses the construction of some stochastic models for population dynamics with a variety of birth and death rate functions. A general model is constructed considering a fundamental growth rate function of the population while allowing random births and deaths in the population. Four stochastic discrete delay models and two non-delay models using the infinitesimal mean and variance given by birth and death rate functions have been produced and analyzed. In these constructions drift terms are in the form of logistic growth or logistic growth with delay. Logistic growth models are well known to biologists and economists. For each model, the existence and uniqueness of the global solution, non-negativeness of the solution is discussed, and for some models, boundedness of the path is also given. Persistence of the population and the boundary behavior have also been discussed through the hitting times. Here, a new method to analyze the hitting times for a specific class of stochastic delay models is presented. This work is related to and also extends the work of Edward Allen, Linda Allen and Bernt Oksendal in population dynamics.

Aravind Chandrashekar, for the Master of Science degree in Electrical and Computer, presented on 02/09/2011, at Southern Illinois University Carbondale. TITLE: Reduction of Cache Related Preemption Delay using DVS in Real Time Systems MAJOR PROFESSOR: Dr. Harini Ramaprasad Embedded/real-time systems are ubiquitous in today's world. Providing temporal guarantees is paramount in such systems. In several multi-tasking real-time systems, tasks are assigned varying priorities and scheduled in accordance with a preemptive scheduling policy. When a task is preempted, a significant number of memory blocks belonging to the particular task are displaced from the cache memory between the time that the task is preempted and the time that the task resumes execution. Upon resumption, a corresponding amount of time is spent in reloading the cache with previously replaced memory blocks, thereby incurring what is known as cache-related preemption delay (CRPD). CRPD of a task due to a given preemption depends on the position in the program where the preempted task is executing at the time of preemption. As such, CRPD at different preemption points may be significantly different. In this thesis, we exploit this difference in CRPD and use dynamic voltage/frequency scaling (DVFS) to control the execution speed of a task such that it gets preempted in regions where the CRPD is low, as far as is possible without jeopardizing system schedulability. Simulation results demonstrate that our algorithm reduces number of cache reloads due to preemption to a reasonable extent, thereby reducing the repeated usage of off-chip memory bandwidth.

In everyday decision making, people often face decisions with outcomes that differ on multiple dimensions. The tradeoff in preferences between magnitude of reinforcement, delay to reinforcement, and probability of reinforcement is a fundamental concern in the decision making literature. Yet, the relative impacts of probability of reinforcement, delay to reinforcement, and magnitude of reinforcement have not been studied together even though researchers have been advocating for the combined study of these variables for decades. The proposed project was designed to determine the relative impacts of magnitude of reinforcement and probability of reinforcement when they were both increasing over a 10 s delay to maximum charge. A first-person shooter video game was adapted for the study of choice when outcome magnitude and probability of reinforcement were increasing either simultaneously (Experiment 1) or separately (Experiment 2) over a 10 s delay. Experiment 1 showed that participants waited longer to ensure a greater probability of reinforcement than to ensure a greater magnitude of reinforcement. The results of Experiment 2 indicated that probability of reinforcement had a stronger impact on behavior than magnitude of reinforcement when they were increasing separately. These experiments indicated that probability of reinforcement outweighed magnitude of reinforcement by a ratio of approximately 3:1.

The present study used a delay discounting task and the Valued Living Questionnaire to examine the relationship between delay discounting and self-reported values. Thirty-eight participants completed the study. Participants were asked to make choices between immediate and delayed monetary rewards to determine rates of discounting. An exponential function (R2=0.97) provided a strong fit for discounting scores. On the Valued Living Questionnaire, participants rated on a Likert-type scale of 1-10 both the importance and their action in the previous week toward the following values: Family, marriage, parenting, friends, work, education, recreation, spirituality, community, and physical well-being. A composite valued living scored was calculated and compared to participant discounting rates; results suggest that there was a significant relationship between participant valued living scores and K-values (p<0.01) and participant valued living scores and AUC (p<0.02). The results of this study, while preliminary, are important for beginning to understand how values impact decision making.

The purpose of this study was to determine the effects of whether pounds are being lost or gained on the rate at which people discount the value of weight change outcomes, as well as determine the effects of whether pounds are being lost or gained and diet length on the value of access to higher calorie foods relative to weight change outcomes. This was accomplished by repeatedly asking participants to choose between two dietary options of the same length but which resulted in gaining or losing a certain number of pounds. Each question varied the length of the diet, how many pounds could be gained or lost, and whether those pounds were being gained when they chose the higher calorie diet or lost when they chose the lower calorie diet. The survey was administered with 30 participants. Whether pounds per being gained or lost did not have a significant effect on the rate at which weight change outcomes were discounted (t = 1.883, p = .07), but did have a significant effect on how many pounds needed to be at stake per day in order for the participant to choose the lower calorie diet (t = 4.995, p < .01). There was also a significant correlation between diet length and how many pounds needed to be at stake per day in order for the participant to choose the lower calorie diet (ρ = -.373, p <.01). The current investigation has implications for our understanding of choice and discounting behavior, and has specific implications for people who wish to make healthier dietary decisions.

The study examined how individuals make decisions on hypothetical sexual partners and hypothetical monetary rewards in delay and probability discounting. The participants (N-75, males=42 (M=34) and females=33(M=39)) completed an electronic survey via Qualtrics. The survey consisted of 6 tasks: 1. Multiple Stimulus without Replacement Preference Assessment that consisted of pictures of potential sex partners based on the individual’s gender preference (male, female, or both); 2. Sexual Risk Survey; 3. Monetary delay discounting task; 4. Monetary probability discounting task; 5. Delay discounting of hypothetical sexual partners; and 6. Probability discounting of hypothetical sexual partners. An analysis of area under the curve (AUC) were done for the discounting tasks. The results showed that males devalued delayed sexual partner choice rank higher rates than females (t (7.97) = 2.85, p<0.05). This was also observed in females with higher scores of the Sexual Risk Survey than the lower scorers (t (10.95) = 2.35, p<0.05). AUC reflected on the scores of the SRS and with measures of sexual risk behaviours. However, there were no significant difference in discounting monetary rewards between the genders (t (11.96) = 0.1623, p>0.05).

The purpose of the current study is to measure whether delay discounting and impulsivity will differentiate between smokers and non-smokers. It is important to extend upon previous research to understand the effects of antecedent control of delay discounting and impulsivity. Research on this subject is important in developing effective interventions for impulsive behavior like smoking cigarettes. Two surveys were provided to participants: The Monetary Choice Questionnaire (MCQ-27) and the Barratt Impulsivity Scale (BIS-11). An unpaired t test was used to interpret results. Neither the MCQ-11 nor the BIS-11 had a significant difference. Further analysis was conducted comparing age differences using unpaired and paired t tests. There was significant data to support that self-ratings of impulsive behavior differed with age comparisons in the BIS-11. Smokers (ages 26-28) were more impulsive than non-smokers (ages 22-28), and smokers (ages 20-29) showed no statistical significance when compared to smokers (ages 52-68). The MCQ-27 did not show a significant difference in overt impulsive behavior.

Magíster en Ingeniería de Redes de Comunicaciones / El escenario actual de las redes tradicionales es que cada nodo de red tiene su propia unidad de procesamiento y administra sus planos de control y de datos de usuarios, donde la complejidad de la gestión de la red aumenta conforme crece su tamaño. Ante este escenario se da un cambio importante en la manera de hacer networking, adoptándose las redes SDN, Software Defined Networks. Esta tecnología busca mejorar los resultados globales en desempeño y administración de las redes de comunicaciones. Paralelo a esto, el uso de servidores web se ha ido popularizando dentro de Internet, dado que son capaces de brindar diferentes tipos de servicios como transacciones bancarias, streaming, comunicaciones cifradas, etc. Las redes SDN han sido desplegadas por grandes compañías como por ejemplo Google que terminó la implementación de SDN en el año 2011. Aunque SDN está siendo globalmente adoptado, no es utilizado masivamente por empresas de distintos tamaños y no está estandarizado en su totalidad, por lo que es necesario desarrollar estudios que nos indiquen de manera técnica, las diferencias, desventajas y virtudes que tienen en comparación con las tecnologías legacy. casa En este trabajo se desarrolla un escenario de pruebas de un servidor web sobre una red SDN y legacy (red tradicional). Las pruebas consisten en variar la condiciones de red como: delay y packet loss, y la tecnología de acceso entre WLAN (wireless local area network) y LTE (long term evolution). Para construir los escenarios de pruebas se utilizan herramientas de hardware y software al alcance de cualquier investigador. Se emulan componentes de la red y se utiliza hardware especializado, generándose resultados desde el tráfico real que circuló por la infraestructura de los proveedores de Internet. Antes de la ejecución de las pruebas se determina mediante estadística descriptiva, los niveles de delay y packet loss a usar en los experimentos. Este análisis es necesario dado que no se desea incluir condiciones de red que interrumpan totalmente las comunicaciones o que generen comportamientos anómalos en la red. Adicionalmente se calcula el número de muestras necesario para determinar la veracidad de las hipótesis planteadas, con un rango de niveles de confianza entre un 90 % y 70 %. Para la resolución de las hipótesis se diseñan modelos estadísticos que permiten comparar el comportamiento de SDN en el tiempo, estos modelos se usan como entradas para distintas pruebas y análisis de las hipótesis planteadas. Finalmente se concluye que, aunque una infraestructura SDN y una infraestructura legacy presentan marcadas diferencias en su funcionamiento para soportar los servicios web, su desempeño comparando el número de conexiones exitosas y el throughput es similar, y estadísticamente idéntico en varios casos analizados, con un máximo de 3 % de diferencia para las conexiones exitosas y 2;1x10−6 % para el throughput. Se presentan pequeñas diferencias en los casos en los que no se encuentran desempeños similares siendo estos a favor de una infraestructura legacy.

Esta pesquisa teve como objetivo estudar as condiÃÃes clÃnicas de crianÃas com paralisia cerebral em um serviÃo de referÃncia em atendimento pediÃtrico no municÃpio de Fortaleza, bem como identificar os principais fatores de risco para a paralisia cerebral, determinar suas repercussÃes e o grau de comprometimento no desenvolvimento normal da populaÃÃo estudada, estabelecer o tempo mÃdio decorrido entre a percepÃÃo das alteraÃÃes do desenvolvimento pela famÃlia, o diagnÃstico e encaminhamento mÃdico e admissÃo da crianÃa no serviÃo. Trata-se de um estudo transversal descritivo, realizado no NÃcleo de AtenÃÃo MÃdico Integrada (NAMI) da Universidade de Fortaleza (UNIFOR), no perÃodo de fevereiro a junho de 2005, onde foram avaliadas 85 crianÃas com diagnÃstico definitivo de Paralisia Cerebral (PC), na faixa etÃria de zero a doze anos, com alteraÃÃes sensÃrio-motoras em tÃnus, postura e movimento, dÃficits visuais e auditivos. Os dados coletados foram arquivados em base eletrÃnica EPI-INFO versÃo 6.01 e mostraram os seguintes resultados: a amostra foi constituÃda por 50,6% de crianÃas do sexo masculino, sendo a mÃdia de idade de 4 anos e 3 meses, 85,9% foram procedentes de Fortaleza com mÃdia de idade ao diagnÃstico de PC de 11 meses. Houve um grande percentual de crianÃas que sofreram complicaÃÃes neonatais (77,4%), tendo o desconforto respiratÃrio destacado-se fazendo com que 65,3% recebessem cuidados em UTI neonatal. A maioria das crianÃas apresentou PC do tipo espÃstica (69,1%), de grau severo (51,8%), tetraplÃgicas (71,4%), apenas 27% comunicavam-se verbalmente e 53% freqÃentavam a escola regularmente. Pode-se concluir que a maioria das crianÃas apresenta grave comprometimento sensÃrio-motor e que os primeiros sinais de tal comprometimento foram percebidos por seus familiares, apesar da grande maioria ter recebido atendimento pediÃtrico de rotina no 1Â ano de vida, poucas foram avaliadas e receberam algum tipo de orientaÃÃo sobre o desenvolvimento neuropsicomotor durante as consultas, fato esse que nos alerta sobre a necessidade de realizaÃÃo de conscientizaÃÃo junto a profissionais da atenÃÃo bÃsica para importÃncia da avaliaÃÃo periÃdica do desenvolvimento no 1Â ano de vida, para que se possa assim identificar e encaminhar crianÃas com possÃveis atrasos e patologias graves como a PC em tempo cada vez mais hÃbil, aumentando a probabilidade de uma melhor qualidade de vida. / This research aimed to study the clinical conditions of children with cerebral palsy in a reference service in pediatric care in Fortaleza as well as identify the main risk factors for cerebral palsy, to determine its impact and the degree of impairment in normal development the study population, establish the average time elapsed between the perception of changes in the family development, diagnosis and medical referral and admission of the child in the service. This is a cross sectional study, conducted at the Center for Integrated Medical Care (NAMI), University of Fortaleza (UNIFOR) in the period from February to June 2005, evaluating 85 children with definite diagnosis of cerebral palsy (CP) in aged zero to twelve years, with changes in sensory-motor tone, posture and movement, visual and hearing deficits. The collected data were stored on base Electronic EPI-INFO version 6.01 and the following results: the sample comprised 50.6% of male children, with a mean age of 4 years and 3 months, 85.9% were coming from Fortaleza mean age at CP diagnosis of 11 months. There was a large percentage of children who suffered neonatal complications (77.4%) and respiratory distress leading to making 65.3% received care in the NICU. Most of the children had spastic CP (69.1%), severe (51.8%), quadriplegia (71.4%), only 27% communicated verbally and 53% were attending school regularly. It can be concluded that most children had severe sensory-motor and the first signs of such involvement were perceived by their families, although the majority have received pediatric care routine in the first year of life, few have been evaluated and received some guidance on the psychomotor development during the consultations, a fact that makes us aware of the need to make awareness among the primary care team about the importance of regular assessment of developments in the first year of life, so that we can to identify and refer children with potential delays and serious illnesses such as PC-time increasingly skilled, increasing the likelihood of a better quality of life.

This thesis applies predictor-based methods for the distributed consensus control of multi-agent systems with input delay. "Multi-agent systems" is a term used to describe a group of agents which are connected together to achieve specified control tasks over a communication network. In many applications, the subsystems or agents are required to reach an agreement upon certain quantities of interest, which is referred to as "consensus control". This input delay may represent delays in the network communication. The main contribution of this thesis is to provide feasible methods to deal with the consensus control for general multi-agent systems with input delay. The consensus control for general linear multi-agent systems with parameter uncertainties and input delay is first investigated under directed network connection. Artstein reduction method is applied to deal with the input delay. By transforming the Laplacian matrix into the real Jordan form, delay-dependent conditions are derived to guarantee the robust consensus control for uncertain multi-agent systems with input delay. Then, the results are extended to a class of Lipschitz nonlinear multi-agent systems and the impacts of Lipschitz nonlinearity and input delay in consensus control are investigated. By using tools from control theory and graph theory, sufficient conditions based on the Lipschitz constant are identified for proposed protocols to tackle the nonlinear terms in the system dynamics. Other than the time delay, external disturbances are inevitable in various practical systems including the multi-agent systems. The consensus disturbance rejection problems are investigated. For linear multi-agent systems with bounded external disturbances, Truncated Predictor Feedback (TPF) approach is applied to deal with the input delay and the H_infinity consensus analysis is put in the framework of Lyapunov analysis. Sufficient conditions are derived to guarantee the H_infinity consensus in time domain. Some disturbances in real engineering problems have inherent characteristics such as harmonics and unknown constant load. For those kinds of disturbances in Lipschitz nonlinear multi-agent systems with input delay, Disturbance Observer-Based Control (DOBC) technique is applied to design the disturbance observers. A new predictor-based control scheme is constructed for each agent by utilizing the estimate of the disturbance and the prediction of the relative state information. Sufficient delay-dependent conditions are derived to guarantee consensus with disturbance rejection.