A Human Driver Model for Autonomous Lane Changing in Highways: Predictive Fuzzy Markov Game Driving Strategy

This study presents an integrated hybrid solution to mandatory lane changing problem to deal with accident avoidance by choosing a safe gap in highway driving. To manage this, a comprehensive treatment to a lane change active safety design is proposed from dynamics, control, and decision making aspects. My effort first goes on driver behaviors and relating human reasoning of threat in driving for modeling a decision making strategy. It consists of two main parts; threat assessment in traffic participants, (TV s) states, and decision making. The first part utilizes an complementary threat assessment of TV s, relative to the subject vehicle, SV , by evaluating the traffic quantities. Then I propose a decision strategy, which is based on Markov decision processes (MDPs) that abstract the traffic environment with a set of actions, transition probabilities, and corresponding utility rewards. Further, the interactions of the TV s are employed to set up a real traffic condition by using game theoretic approach. The question to be addressed here is that how an autonomous vehicle optimally interacts with the surrounding vehicles for a gap selection so that more effective performance of the overall traffic flow can be captured. Finding a safe gap is performed via maximizing an objective function among several candidates. A future prediction engine thus is embedded in the design, which simulates and seeks for a solution such that the objective function is maximized at each time step over a horizon. The combined system therefore forms a predictive fuzzy Markov game (FMG) since it is to perform a predictive interactive driving strategy to avoid accidents for a given traffic environment. I show the effect of interactions in decision making process by proposing both cooperative and non-cooperative Markov game strategies for enhanced traffic safety and mobility. This level is called the higher level controller. I further focus on generating a driver controller to complement the automated car’s safe driving. To compute this, model predictive controller (MPC) is utilized. The success of the combined decision process and trajectory generation is evaluated with a set of different traffic scenarios in dSPACE virtual driving environment. Next, I consider designing an active front steering (AFS) and direct yaw moment control (DYC) as the lower level controller that performs a lane change task with enhanced handling performance in the presence of varying front and rear cornering stiffnesses. I propose a new control scheme that integrates active front steering and the direct yaw moment control to enhance the vehicle handling and stability. I obtain the nonlinear tire forces with Pacejka model, and convert the nonlinear tire stiffnesses to parameter space to design a linear parameter varying controller (LPV) for combined AFS and DYC to perform a commanded lane change task. Further, the nonlinear vehicle lateral dynamics is modeled with Takagi-Sugeno (T-S) framework. A state-feedback fuzzy H∞ controller is designed for both stability and tracking reference. Simulation study confirms that the performance of the proposed methods is quite satisfactory

Technological distractions V Motivational factors

This study aims to investigate demands for motivational factor in a classroom environment which has been polluted by increasing distraction caused by the recent technological developments. It is evidently proved that motivations of students are quite important to enhance their learning in the classroom. Some of these factors relates to theextrinsic and intrinsic motivations. The extrinsic motivational factors are treated more inthis study.However, the recent technological developments and their new learning environment have also influence on learning of students. According to a survey more than nine out often British students are distracted by Face book, Twitter and other social networking sitesat least once an hour. As part of motivational factors, rewards are more productive andefficient then punishments in classroom environment. For the good and betterment of teachers and students, educational institutions should start to put into practice "laptopban" and "smart phone ban" or permits.In this paper comparative studies are considered to dig out findings related totechnological distractions V motivational factors.This paper analyzes the distractions caused by the recent technological developmentin the classroom environment. The finding of this paper indicates that banning is not agood option for motivation of the students. It suggests that there should be a balancebetween banning and freeing the usages of the recent developed technologies.In short, it is regarded to conduct a controlling mechanism which can help student show to handle and balance technology use in educational institutions. If students aim forhigh paying jobs, during the lesson they need to switch off their laptop and smart phonesfor better future

A Human Driver Model for Autonomous Lane Changing in Highways: Predictive Fuzzy Markov Game Driving Strategy

This study presents an integrated hybrid solution to mandatory lane changing problem to deal with accident avoidance by choosing a safe gap in highway driving. To manage this, a comprehensive treatment to a lane change active safety design is proposed from dynamics, control, and decision making aspects. My effort first goes on driver behaviors and relating human reasoning of threat in driving for modeling a decision making strategy. It consists of two main parts; threat assessment in traffic participants, (TV s) states, and decision making. The first part utilizes an complementary threat assessment of TV s, relative to the subject vehicle, SV , by evaluating the traffic quantities. Then I propose a decision strategy, which is based on Markov decision processes (MDPs) that abstract the traffic environment with a set of actions, transition probabilities, and corresponding utility rewards. Further, the interactions of the TV s are employed to set up a real traffic condition by using game theoretic approach. The question to be addressed here is that how an autonomous vehicle optimally interacts with the surrounding vehicles for a gap selection so that more effective performance of the overall traffic flow can be captured. Finding a safe gap is performed via maximizing an objective function among several candidates. A future prediction engine thus is embedded in the design, which simulates and seeks for a solution such that the objective function is maximized at each time step over a horizon. The combined system therefore forms a predictive fuzzy Markov game (FMG) since it is to perform a predictive interactive driving strategy to avoid accidents for a given traffic environment. I show the effect of interactions in decision making process by proposing both cooperative and non-cooperative Markov game strategies for enhanced traffic safety and mobility. This level is called the higher level controller. I further focus on generating a driver controller to complement the automated car’s safe driving. To compute this, model predictive controller (MPC) is utilized. The success of the combined decision process and trajectory generation is evaluated with a set of different traffic scenarios in dSPACE virtual driving environment. Next, I consider designing an active front steering (AFS) and direct yaw moment control (DYC) as the lower level controller that performs a lane change task with enhanced handling performance in the presence of varying front and rear cornering stiffnesses. I propose a new control scheme that integrates active front steering and the direct yaw moment control to enhance the vehicle handling and stability. I obtain the nonlinear tire forces with Pacejka model, and convert the nonlinear tire stiffnesses to parameter space to design a linear parameter varying controller (LPV) for combined AFS and DYC to perform a commanded lane change task. Further, the nonlinear vehicle lateral dynamics is modeled with Takagi-Sugeno (T-S) framework. A state-feedback fuzzy H∞ controller is designed for both stability and tracking reference. Simulation study confirms that the performance of the proposed methods is quite satisfactory

Quarantine region scheme to mitigate spam attacks in wireless sensor networks

The Quarantine Region Scheme (QRS) is introduced to defend against spam attacks in wireless sensor networks where malicious antinodes frequently generate dummy spam messages to be relayed toward the sink. The aim of the attacker is the exhaustion of the sensor node batteries and the extra delay caused by processing the spam messages. Network-wide message authentication may solve this problem with a cost of cryptographic operations to be performed over all messages. QRS is designed to reduce this cost by applying authentication only whenever and wherever necessary. In QRS, the nodes that detect a nearby spam attack assume themselves to be in a quarantine region. This detection is performed by intermittent authentication checks. Once quarantined, a node continuously applies authentication measures until the spam attack ceases. In the QRS scheme, there is a tradeoff between the resilience against spam attacks and the number of authentications. Our experiments show that, in the worst-case scenario that we considered, a not quarantined node catches 80 percent of the spam messages by authenticating only 50 percent of all messages that it processe

Auswirkungen monetärer Belohnungen auf die intrinsische Motivation von (ehrenamtlichen) Übungsleitern

Kurzzusammenfassung Die Auszahlung von Geld an Übungsleiter ist im aktuellen Sportvereinswesen gängig. Monetäre Belohnungen können verstärkend oder verdrängend auf die intrinsische Motivation wirken. In der vorliegenden Arbeit wird die Wirkung monetärer Zahlungen auf die intrinsische Motivation von Übungsleitern untersucht. Da intrinsische Motivation u.a. Geldzahlungen anteilig oder vollständig kompensiert, ist die Verdrängung intrinsischer Motivation mit zukünftig höheren monetären Kosten für die Sportvereine verbunden. Dementsprechend wird die verdrängende Wirkung die ohnehin finanziell schwierige Situation der Sportvereine weiter belasten. Aufgrund der besonderen Relevanz ist ein Erkenntnisgewinn über die Auswirkungen monetärer Zahlungen auf die intrinsische Motivation von Übungsleitern von großer Bedeutung. Unter Verwendung psychologischer sowie ökonomischer Theorien und Erklärungsansätzen hinsichtlich der Wirkung monetärer Auszahlungen auf die intrinsische Motivation sind die Forschungsfragen definiert und die theoretischen Modelle aufgestellt worden. Demnach wurde der Effekt der Bezahlung auf die intrinsische Motivation untersucht. Weiterhin ist analysiert worden, ob die Bezahlung dazu führt, dass die Übungsleiter im Ergebnis ihr Verhalten auf das Maximieren des monetären Outputs richten. Für die Beantwortung der Forschungsfragen sind n=511 Übungsleiter mit einem standardisierten Fragebogen befragt worden. Die regressionsanalytischen Auswertungen der Fragebögen zeigen, dass die Bezahlung keine verdrängende Wirkung auf die intrinsische Motivation hat. Lediglich die Bereitschaft, aus innerem Antrieb die Tätigkeit auszuüben, um damit seinem Verein zu helfen, sinkt mit steigender Bezahlung. Darüber hinaus wirkt die Bezahlung positiv auf die extrinsische Motivation. Unabhängig davon, wie stark die intrinsische Motivation der Übungsleiter ist, führt die Bezahlung schlussendlich dazu, dass bei ihnen ein Verhalten entsteht, das sich auf die Maximierung des monetären Outputs konzentriert. Abstract Payments to coaches in sport clubs are common. Monetary rewards can enhance or undermine intrinsic motivation. This study examines the effect of monetary rewards on intrinsic motivation of coaches. Because intrinsic motivation compensates payment entirely or partly, higher monetary costs for sport clubs are the result of a crowding out effect. Accordingly a crowding out effect will further strain the already difficult financial situation of the sport clubs. As a result an increase in knowledge about the effect of monetary rewards on intrinsic motivation of the coaches is important. By applying psychological and economic theories and explanatory approaches concerning the effect of payments on intrinsic motivation the research questions are defined and the theoretical models are established. This leads to the examination of the effect of payments on intrinsic motivation. Furthermore, it is analyzed whether the result of payment will be a behavior on maximizing the monetary output. To answer the research questions 511 coaches were interviewed with a standardized questionnaire. The results of the regression analysis show, that the payments do not undermine intrinsic motivation. Only the willingness of the coaches to do the job on their own accord, in order to help the sports club decreases with increasing payment. Furthermore the payment has a positive effect on extrinsic motivation. Regardless of how strong the intrinsic motivation of the coaches is, payments will ultimately encourage a behavior, which is focused on maximizing their monetary output

Y chromosome microdeletions in infertile men with idiopathic oligo- or azoospermia

About 30–40% of male infertility is due to unknown reasons. Genetic contributions to the disruption of spermatogenesis are suggested and amongst the genetic factors studied, Y chromosome microdeletions represent the most common one. Screening for microdeletions in AZFa, b and c region of Y chromosome showed a big variation among different studies. The purpose of this study was to investigate the prevalence of such deletions in Saudi men. A total of 257 patients with idiopathic oligo- or azoospermia were screened for Y chromosome microdeletions by 19 markers in AZF region. Ten (3.9%) patients had chromosomal rearrangements, six of them showed sex chromosome abnormalities and four patients had apparently balanced autosomal rearrengements. Eight of the remaining 247 patients (3.2%) with a normal karyotype and no known causes of impaired spermatogenesis had Y chromosome microdeletions. Among these, six patients had deletions in AZFc region, one case had a deletion in AZFb and another had both AZFa and AZFc deletions. In conclusion, our study shows that Y chromosome microdeletions are low in our population. We also report for the first time a case with unique point deletions of AZFa and AZFc regions. The lower frequency of deletions in our study suggest that other genetic, epigenetic, nutritional and local factors may be responsible for idiopathic oligo- or azoospermia in the Saudi population

The correlation between endometrial thickness and outcome of in vitro fertilization and embryo transfer (IVF-ET) outcome

<p>Abstract</p> <p>Background</p> <p>To evaluate the relationship between endometrial thickness on day of human chorionic gonadotrophin administration (hCG) and pregnancy outcome in a large number of consecutive in vitro fertilization and embryo transfer (IVF-ET) cycles.</p> <p>Methods</p> <p>A retrospective cohort study including all patients who had IVF-ET from January 2003–December 2005 conducted at a tertiary center.</p> <p>Results</p> <p>A total of 2464 cycles were analysed. Pregnancy rate (PR) was 35.8%. PR increased linearly (r = 0.864) from 29.4% among patients with a lining of less than or equal to 6 mm, to 44.4% among patients with a lining of greater than or equal to 17 mm. ROC showed that endometrial thickness is not a good predictor of PR, so a definite cut-off value could not be established (AUC = 0.55).</p> <p>Conclusion</p> <p>There is a positive linear relationship between the endometrial thickness measured on the day of hCG injection and PR, and is independent of other variables. Hence aiming for a thicker endometrium should be considered.</p

Infertility treatment outcome in sub groups of obese population

<p>Abstract</p> <p>Background</p> <p>Obesity is a common disorder with a negative impact on IVF treatment outcome. It is not clear whether morbidly obese women (BMI >= 35 kg/m2) respond to treatment differently as compared to obese women (BMI = 30–34.9 kg/m2) in IVF. Our aim was to compare the outcome of IVF or ICSI treatments in obese patients to that in morbidly obese patients.</p> <p>Methods</p> <p>This retrospective cohort study was conducted in a tertiary care centre. Patients inclusion criteria were as follows; BMI ≥ 30, age 20–40 years old, first cycle IVF/ICSI treatment with primary infertility and long follicular pituitary down regulation protocol.</p> <p>Results</p> <p>A total of 406 obese patients (group A) and 141 morbidly obese patients (group B) satisfied the inclusion criteria. Average BMI was 32.1 ± 1.38 kg/m2 for group A versus 37.7 ± 2.99 kg/m²for group B. Patient age, cause of infertility, duration of stimulation, fertilization rate, and number of transferred embryos were similar in both groups. Compared to group A, group B had fewer medium size and mature follicles (14 vs. 16), fewer oocytes collected (7 vs. 9) and required higher doses of HMG (46.2 vs. 38.5 amps). There was also a higher cancellation rate in group B (28.3% vs. 19%) and lower clinical pregnancy rate per started cycle (19.9% vs. 28.6%).</p> <p>Conclusion</p> <p>In a homogenous infertile and obese patient population stratified according to their BMI, morbid obesity is associated with unfavorable IVF/ICSI cycle outcome as evidenced by lower pregnancy rates. It is recommended that morbidly obese patients undergo appropriate counseling before the initiation of this expensive and invasive therapy.</p