Re-arrangement of traffic signal timings by cyclic vehicle queue profile

Traffic signal timing is one of the interesting subjects that have been considered by transportation engineers and researchers. In spite of many technological and innovative solutions, fixed time controlling approach is still applying widely in the world. Signal timings are pre-defined in fixed time control and many programs can be applied for time of day. But in some cases, these programs can be insufficient for the demands occurred by variations in traffic flows. Assigned signal timings can be more or less than that of the timings required. Thus, vehicle delays can increase because of these irregular assignments. In this study, cyclic vehicle queue profile is considered for re-arrangement of signal timings at isolated intersections. Observations were made at sample intersections in Denizli, Turkey. 5 isolated intersections were considered and cyclic based observations were made for peak and off-peak periods. Traffic compositions were taken into account in the observations, cyclic traffic flow profile and remaining number of vehicles for each cycle was determined. Based on these observations, average remaining queue, average discharging time of queue, remaining phase time were measured. Present cycle times were modified depending on remaining phase times and new cycle times were calculated. The average delay times of the traffic flows for new cycle times were calculated with Akcelik delay formula. In addition, they were compared to that of existing cycle time. The results showed that at least 30% improvements can be obtained by re-arrangement of signal timings considering cyclic vehicle queue profile

Investigation of Cyclic Vehicle Queue and Delay Relationship for Isolated Signalized Intersections

AbstractDelay is the one of the design criteria that has been used for performance evaluation of signalized intersections. In pre-timed control, vehicle delays can be minimized or reduced by proper design of signal timings and phasing. But vehicle delays include many parameters such as signal timing, number of phases, vehicle headways, saturation flow, queueing etc. Among these parameters vehicle queue is formed by unbalanced signal timings or unexpected demand values. On the other hand, headways of vehicles can be effective on queue forming especially in discharging case. It is also related to driver behaviors. In this paper, relationship of cyclic vehicle queue and vehicular delay is investigated considering different signal timings and phase sequencing. The data are obtained from observations that are made at urban intersections of Denizli city, Turkey. Regression analysis is used for relationship and statistical tests are applied. The MuLReD (Multiple Linear Regression Analysis based Delay Estimation) model is developed and significance of the model is proved by statistically. Adjusted R2 value of MuLReD Model is obtained as 0,95. On the other hand, delay values obtained from the MuLReD Model and Akcelik Vehicle Delay Formula are compared with each other. As a result of comparisons, Mean Square Error (MSE) values for Akcelik Equation and the MuLReD Model are determined as about 112 and 7 respectively. These results show that outcomes obtained by the MuLReD Model are closer to field observations. Discussions about the present delay formulas, are also reported in the paper

Memristor-based series voltage regulators

Series linear voltage regulators are integrated circuits commonly used to make adjustable voltage sources. When used with potentiometers, these regulators are able to give adjustable voltage at the output. Memristor is a new nonlinear circuit element which came out in the last decade. It is able to provide electronically adjustable resistance. If a memristor is fed with a voltage over the threshold and it is not under saturation, its resistance also called memristance is dependent on the integration of its current, also called memristor charge. Memristor shows promise for different types and lots of digital and analog applications. In this paper, memristor-based series voltage regulator topologies are suggested and they are examined using parameters and simulations. Some design criteria have been given for the memristor-based series voltage regulators

Narcolepsy Along with an Update

Narcolepsy is the most common primary hypersomnia, which is caused by loss of hypocretin neurons. Hypocretin in the neurohypothalamus is of crucial role in the maintenance of awakeness. Narcolepsy is characterized by hypnagogic/hypnopompic hallucinations, sleep paralysis and disrupted night sleep in addition to hypersomnia. Cataplexy is the pathognomonic feature of narcolepsy observed in 60-90% of all cases. As the clinical characteristics of narcolepsy may be confused with various other sypmtoms or signs, diagnostic difficulty is common in narcoleptic patients. Besides this, classification of narcolepsy has recently been changed and recommended as type 1 and type 2 rather than narcolepsy with or without cataplexy. Here, an update on narcolepsy is presented along with a comprehensive summary that can help to overcome the challenges in the diagnosis of narcolepsy

Development of Methodology for Programming Autonomous Agents

A brief report discusses the rationale for, and the development of, a methodology for generating computer code for autonomous-agent-based systems. The methodology is characterized as enabling an increase in the reusability of the generated code among and within such systems, thereby making it possible to reduce the time and cost of development of the systems. The methodology is also characterized as enabling reduction of the incidence of those software errors that are attributable to the human failure to anticipate distributed behaviors caused by the software. A major conceptual problem said to be addressed in the development of the methodology was that of how to efficiently describe the interfaces between several layers of agent composition by use of a language that is both familiar to engineers and descriptive enough to describe such interfaces unambivalentl