Comparative evaluation of microscopic car-following behavior

Microscopic traffic-simulation tools are increasingly being applied to evaluate the impacts of a wide variety of intelligent transport, systems (ITS) applications and other dynamic problems that are difficult to solve using traditional analytical models. The accuracy of a traffic-simulation system depends highly on the quality of the traffic-flow model at its core, with the two main critical components being the car-following and lane-changing models. This paper presents findings from a comparative evaluation of car-following behavior in a number of traffic simulators [advanced interactive microscopic simulator for urban and nonurban networks (AIMSUN), parallel microscopic simulation (PARAMICS), and Verkehr in Statiten-simulation (VISSIM)]. The car-following algorithms used in these simulators have been developed from a variety of theoretical backgrounds and are reported to have been calibrated on a number of different data sets. Very few independent studies have attempted to evaluate the performance of the underlying algorithms based on the same data set. The results reported in this study are based on a car-following experiment that used instrumented vehicles to record the speed and relative distance between follower and leader vehicles on a one-lane road. The experiment was replicated in each tool and the simulated car-following behavior was compared to the field data using a number of error tests. The results showed lower error values for the Gipps-based models implemented in AIMSUN and similar error values for the psychophysical spacing models used in VISSIM and PARAMICS. A qualitative drift and goal-seeking behavior test, which essentially shows how the distance headway between leader and follower vehicles should oscillate around a stable distance, also confirmed the findings.

A genetically informed study of the association between harsh punishment and offspring behavioral problems

Conclusions about the effects of harsh parenting on children have been limited by research designs that cannot control for genetic or shared environmental confounds. The present study used a sample of children of twins and a hierarchical linear modeling statistical approach to analyze the consequences of varying levels of punishment while controlling for many confounding influences. The sample of 887 twin pairs and 2,554 children came from the Australian Twin Registry. Although corporal punishment per se did not have significant associations with negative childhood outcomes, harsher forms of physical punishment did appear to have specific and significant effects. The observed association between harsh physical punishment and negative outcomes in children survived a relatively rigorous test of its causal status, thereby increasing the authors' conviction that harsh physical punishment is a serious risk factor for children.

Household waste recycling behavior: a market segmentation model

The potential of social marketing has been recognized in the United Kingdom by the Department for Environment, Food and Rural Affairs (DEFRA) as a useful tool for behavioral change for environmental problems. The techniques of social marketing have been used successfully by health organizations to tackle current public health issues. This article describes a research project which explored the current barriers to recycling household waste and the development of a segmentation model which could be used at the local level by authorities charged with waste collection and disposal. The research makes a unique contribution to social marketing through the introduction of a competencies framework and market segmentation for recycling behaviors.

Agency theory problems behind the fall of shopping centers

The present article assesses agency theory related problems contributing to the fall of shopping centers. The negative effects of the financial and economic downturn started in 2008 were accentuated in emerging markets like Romania. Several shopping centers were closed or sold through bankruptcy proceedings or forced execution. These failed shopping centers, 10 in number, were selected in order to assess agency theory problems contributing to the failure of shopping centers; as research method qualitative multiple cases-studies is used. Results suggest, that in all of the cases the risk adverse behavior of the External Investor- Principal, lead to risk sharing problems and subsequently to the fall of the shopping centers. In some of the cases Moral Hazard (lack of Developer-Agent’s know-how and experience) as well as Adverse Selection problems could be identified. The novelty of the topic for the shopping center industry and the empirical evidences confer a significant academic and practical value to the present article.

Research on the influence of behavioral forces that motivate trader behavior and sentiment: A prospect theory exegesis

This study focuses on empirical investigations and seeks implications by utilizing three different methodologies to test various aspects of trader behavior. The first methodology utilizes Prospect Theory to determine trader behavior during periods of extreme wealth contracting periods. Secondly, a threshold model to examine the sentiment variable is formulated and thirdly a study is made of the contagion effect and trader behavior. ^ The connection between consumers' sense of financial well-being or sentiment and stock market performance has been studied at length. However, without data on actual versus experimental performance, implications based on this relationship are meaningless. The empirical agenda included examining a proprietary file of daily trader activities over a five-year period. Overall, during periods of extreme wealth altering conditions, traders "satisfice" rather than choose the "best" alternative. A trader's degree of loss aversion depends on his/her prior investment performance. A model that explains the behavior of traders during periods of turmoil is developed. Prospect Theory and the data file influenced the design of the model. ^ Additional research included testing a model that permitted the data to signal the crisis through a threshold model. The third empirical study sought to investigate the existence of contagion caused by declining global wealth effects using evidence from the mining industry in Canada. Contagion, where a financial crisis begins locally and subsequently spreads elsewhere, has been studied in terms of correlations among similar regions. The results provide support for Prospect Theory in two out of the three empirical studies. ^ The dissertation emphasizes the need for specifying precise, testable models of investors' expectations by providing tools to identify paradoxical behavior patterns. True enhancements in this field must include empirical research utilizing reliable data sources to mitigate data mining problems and allow researchers to distinguish between expectations-based and risk-based explanations of behavior. Through this type of research, it may be possible to systematically exploit "irrational" market behavior. ^

Hotel Managers Identify Ethical Problems: A Survey of their Concerns

This study identified and examined the concerns of hotel general managers regarding ethics in the hospitality industry. Thirty-five managers were interviewed during and immediately following the economic recession to determine which ethical issues in the hotel industry and at their own properties concerned them the most. Results showed that more people and organizations attempted to renegotiate hotel rates, which actions, in turn, led to some lapses in ethical behavior. Managers said that because of the economic downturn, they felt pressure from both private owners and corporate headquarters. They also said a lack of work ethic, low motivation, and low pay caused many workers to underperform in ways that raised ethical issues. Managers also mentioned diversity issues and theft by both guests and employees as ethical issues of concern, and shared stories about their experiences.

Research on the influence of behavioral forces that motivate trader behavior and sentiment- a prospect theory exegesis

This study focuses on empirical investigations and seeks implications by utilizing three different methodologies to test various aspects of trader behavior. The first methodology utilizes Prospect Theory to determine trader behavior during periods of extreme wealth contracting periods. Secondly, a threshold model to examine the sentiment variable is formulated and thirdly a study is made of the contagion effect and trader behavior. The connection between consumers' sense of financial well-being or sentiment and stock market performance has been studied at length. However, without data on actual versus experimental performance, implications based on this relationship are meaningless. The empirical agenda included examining a proprietary file of daily trader activities over a five-year period. Overall, during periods of extreme wealth altering conditions, traders "satisfice" rather than choose the "best" alternative. A trader's degree of loss aversion depends on his/her prior investment performance. A model that explains the behavior of traders during periods of turmoil is developed. Prospect Theory and the data file influenced the design of the model. Additional research included testing a model that permitted the data to signal the crisis through a threshold model. The third empirical study sought to investigate the existence of contagion caused by declining global wealth effects using evidence from the mining industry in Canada. Contagion, where a financial crisis begins locally and subsequently spreads elsewhere, has been studied in terms of correlations among similar regions. The results provide support for Prospect Theory in two out of the three empirical studies. The dissertation emphasizes the need for specifying precise, testable models of investors' expectations by providing tools to identify paradoxical behavior patterns. True enhancements in this field must include empirical research utilizing reliable data sources to mitigate data mining problems and allow researchers to distinguish between expectations-based and risk-based explanations of behavior. Through this type of research, it may be possible to systematically exploit "irrational" market behavior.

Impact of ocean acidification in the metabolism and swimming behavior of the dolphinfish (Coryphaena hippurus) early larvae

Since the industrial revolution, [CO2]atm has increased from 280 µatm to levels now exceeding 380 µatm and is expected to rise to 730-1,020 µatm by the end of this century. The consequent changes in the ocean's chemistry (e.g., lower pH and availability of the carbonate ions) are expected to pose particular problems for marine organisms, especially in the more vulnerable early life stages. The aim of this study was to investigate how the future predictions of ocean acidification may compromise the metabolism and swimming capabilities of the recently hatched larvae of the tropical dolphinfish (Coryphaena hippurus). Here, we show that the future environmental hypercapnia (delta pH 0.5; 0.16 % CO2, ~1,600 µatm) significantly (p < 0.05) reduced oxygen consumption rate up to 17 %. Moreover, the swimming duration and orientation frequency also decreased with increasing pCO2 (50 and 62.5 %, respectively). We argue that these hypercapnia-driven metabolic and locomotory challenges may potentially influence recruitment, dispersal success, and the population dynamics of this circumtropical oceanic top predator.

Least Squares Approach to Inverse Problems in Musculoskeletal Biomechanics

Inverse simulations of musculoskeletal models computes the internal forces such as muscle and joint reaction forces, which are hard to measure, using the more easily measured motion and external forces as input data. Because of the difficulties of measuring muscle forces and joint reactions, simulations are hard to validate. One way of reducing errors for the simulations is to ensure that the mathematical problem is well-posed. This paper presents a study of regularity aspects for an inverse simulation method, often called forward dynamics or dynamical optimization, that takes into account both measurement errors and muscle dynamics. The simulation method is explained in detail. Regularity is examined for a test problem around the optimum using the approximated quadratic problem. The results shows improved rank by including a regularization term in the objective that handles the mechanical over-determinancy. Using the 3-element Hill muscle model the chosen regularization term is the norm of the activation. To make the problem full-rank only the excitation bounds should be included in the constraints. However, this results in small negative values of the activation which indicates that muscles are pushing and not pulling. Despite this unrealistic behavior the error maybe small enough to be accepted for specific applications. These results is a starting point start for achieving better results of inverse musculoskeletal simulations from a numerical point of view.

Psichological and behavioral problems among left-behind adolescents. The case of Ecuador

Objetivo: evaluar el impacto de la migración de los padres en el bienestar psicológico de los ado - lescentes en abandono (LBA) en el Ecuador. Ado - lescentes abandonados son quienes permanecen en su país de origen, mientras su (s) padre (s) mi - graron. Métodos: en un estudio Transversal, 659 adoles - centes de edad escolar (43% mujeres, con una edad media de 13.9 +- 1.2) llenaron los cuestio - narios de fortalezas y dificultades (SDQ), y deter - minantes socio-demográficos. Las estadísticas fue - ron utilizadas para comparar el impacto de los determinantes socio-demográficos en el grupo de adolescentes en abandono (LBA) y adolescentes en no abandono (NLBA). Resultados: El 46% de los (LBA) puntuaron sig - nificativamente más alto en el cuestionario (SDQ) que los (NLBA), especialmente las niñas. Los de - terminantes socio-demográficos fueron significa - tivamente asociados con menos problemas psico - lógicos, por ejemplo, hablando acerca de problemas personales y migración después de la edad de 5 años en LBA. Conclusiones: la migración de los padres tiene un impacto en el bienestar psicológico de los adolescentes en abandono en el Ecuador. Las ca - racterísticas socio-demográficas influencian dicho impacto. Este artículo enfatiza un importante y hasta ahora ignorado problema de salud publica en el Ecuador. Esto subraya la necesidad del des - arrollo de políticas de salud y una profunda in - vestigación

Prevalence of vocal problems in portuguese primary and secondary shool level teachers

This study compared the prevalence of vocal problems in two Portuguese groups: 73 teachers that use their voice as professional tool (teachers’ group) and 73 non-voice professionals (control group). It also identified the risk factors that contributed to teachers’ group voice problems. A questionnaire was applied to both goups in order to obtain information about vocal health, hygiene and behavior, professional activity and general physical health. Statistical results revealed that the teachers’ group presented a higher prevalence of vocal problems than the control group: 52% reported hoarseness, 46.6% vocal fatigue and 45.2% vocal discomfort compared with 31.5%, 20.5 % e 28.7%, respectively. Environmental factors (eg., smoke and cold temperatures), vocal abuse and upper respiratory pathologies (e.g., colds, laryngitis and pharyngitis) seemed to increase teachers’ voice disorders (p-value < .05). In conclusion, the absence of vocal pedagogy in the curricular plan of teachers’ higher education associated to poor working environmental conditions and professional voice demands explained the higher prevalence of vocal problems in teachers’ group.

Some misspecfication problems in long-memory time series models

Doctor of Philosophy in Mathematics

Emotional skills and promoting School Success in the 3rd cycle: students perception

Problem Statement: The perceptions about school, play a central role in behavior, performance and results. There is evidence that an improvement in emotional skills is associated with a higher success. Research Questions: What is the relationship between internalizing and externalizing behaviors, emotional skills and academic success in the 3rd cycle of basic education? Purpose of Study: To promote social and emotional skills of students, in the 3rd cycle of basic education. Research Methods: A pilot study with groups of 7th year at a school central Portugal. Made diagnosis of disruptive behavior (ASEBA) was identified 6 children aged 12 0s and 14 and followed by 3 focus groups with students, parents, and teachers respectively. Findings: 6 students mostly male were identified (70 %), with the predominance of externalizing behaviors and academic failure. Not like school (80%) and have no motivation for learning. The relationship between parents and teachers is conflituoso. 100 % of parents have the utmost concern academic success and teachers perceptional good practices, but without success. Conclusions: This program is seen in a perspective of empowerment of the various educational agents to manage various environments and relationships. The results point to the importance of the focus group in the awareness of relational problems in schools. Less adjusted change behaviors imply the involvement of all educators.

An intervention program for children with school failure problems.

School failure is a chronic problem in many developing countries and in some developed as Portugal due to factors like cognitive deficiencies of children, an inadequate family environment, low SES and bad teaching methods or school organization. It is important to develop effective and simple intervention strategies able to cope with the problem at an individual level independently of the cause. The general objective of the following study is to develop behavioral training techniques to help children with problems of school failure. 6 - 12 years old children attending ISCED 1, with academic difficulties because of family problems, social exclusion (living in poverty or belonging to an ethnic minority) or poor schooling were trained. Cognitive-behavioral techniques that have been widely used to train persons with intellectual, sensorial, physical or social deficiencies were applied. Results are evaluated in terms of % of attained objectives, time, and (subjective) teacher satisfaction. Some results of individual children are shown. Training programs seem to be successful independently of the (mostly unknown) cause of failure of the trained subject.