Sudden Speed Changes Research Articles

Design of Speed-Controller for Brushless DC-Motor Based on Grey Predictor-PID Controller

Brushless direct current (BLDC) motor is a permanent-magnet synchronous motor but the commutator and the brushes are replaced by electronic commutation system. This motor is characterized by many advantages compared with other motors and it being used in a wide range of applications. In BLDC motor, speed control plays an essential role; the speed-controller has to respond rapidly to command changes and to offer enough robustness against the variations of the mechanical load. In this paper, the design of Grey-PID controller is proposed as speed controller of BLDC motor where a new adaptation algorithm is suggested to update the parameters of the adaptive PID controller. The proposed algorithm takes advantages of both of Grey model GM(1,1) and gradient-descent method. The Grey-PID speed control system is simulated by using MatlabSimulink environment. The simulation results confirm that the proposed controller performs better than the traditional PID controller. By using Grey-PID controller, starting the motor or sudden change of speed can be performed with short rise and settling times, no overshoot and no steady-state error. The proposed controller, also, has a great ability to restrain the fluctuation of speed caused by load disturbance.

Quantum-Behaved Lightning Search Algorithm to Improve Indirect Field-Oriented Fuzzy-PI Control for IM Drive

The main objective of this study is to develop a quantum-behaved lightening search algorithm (QLSA) to improve the indirect field-oriented fuzzy-proportional-integral (PI) controller technique to control a three-phase induction motor (TIM) drive. The generated adaptive PI current control parameters and fuzzy membership functions are carried to design induction motor drive speed controller to minimize the fitness function formulated by QLSA. An optimal QLSA-based indirect field-oriented control (QLSA-IFOC) fitness function is used to reduce the mean absolute error of the rotor speed to improve the performance of the TIM with varying speed and mechanical load. Results obtained from the QLSA-IFOC are compared with those obtained through lightening search algorithm, gravitational search algorithm, backtracking search algorithm, and particle swarm optimization to validate the developed controller. The optimization results of objective functions in terms of box plots and iterations show that the QLSA algorithm outperforms the other optimization algorithms. Moreover, the QLSA-IFOC controller performed well in all tests in terms of transient response. The developed controller also minimizes overshoot, increases damping capability, and reduces the root-mean-square error, as well as standard deviation under sudden change of speed and mechanical loads. A comparative analysis is performed between simulation and experimental results to justify the efficiency of the developed controller.

Epidemiology of Hip and Groin Injuries in Collegiate Athletes in the United States.

Background:Hip and groin pain is a common complaint among athletes. Few studies have examined the epidemiology of hip and groin injuries in collegiate athletes across multiple sports.Purpose:To describe the rates, mechanisms, sex-based differences, and severity of hip/groin injuries across 25 collegiate sports.Study Design:Descriptive epidemiology study.Methods:Data from the 2009-2010 through 2013-2014 academic years were obtained from the National Collegiate Athletic Association Injury Surveillance Program (NCAA ISP). The rate of hip/groin injuries, mechanism of injury, time lost from competition, and need for surgery were calculated. Differences between sex-comparable sports were quantified using rate ratios (RRs) and injury proportion ratios (IPRs).Results:In total, 1984 hip/groin injuries were reported, giving an overall injury rate of 53.06 per 100,000 athlete-exposures (AEs). An adductor/groin tear was the most common injury, comprising 24.5% of all injuries. The sports with the highest rates of injuries per 100,000 AEs were men’s soccer (110.84), men’s ice hockey (104.90), and women’s ice hockey (76.88). In sex-comparable sports, men had a higher rate of injuries per 100,000 AEs compared with women (59.53 vs 42.27, respectively; RR, 1.41 [95% CI, 1.28-1.55]). The most common injury mechanisms were noncontact (48.4% of all injuries) and overuse/gradual (20.4%). In sex-comparable sports, men had a greater proportion of injuries due to player contact than women (17.0% vs 3.6%, respectively; IPR, 4.80 [95% CI, 3.10-7.42]), while women had a greater proportion of injuries due to overuse/gradual than men (29.1% vs 16.7%, respectively; IPR, 1.74 [95% CI, 1.46-2.06]). Overall, 39.3% of hip/groin injuries resulted in time lost from competition. Only 1.3% of injuries required surgery.Conclusion:Hip/groin injuries are most common in sports that involve kicking or skating and sudden changes in direction and speed. Most hip/groin injuries in collegiate athletes are noncontact and do not result in time lost from competition, and few require surgery. This information can help guide treatment and prevention measures to limit such injuries in male and female collegiate athletes.

Fédération Equestre Internationale (FEI) endurance events: Riding speeds as a risk factor for failure to qualify outcomes (2012–2015)

This study examined the association between riding speed and elimination in Fédération Equestre Internationale (FEI) endurance events. A total of 35,061 horse starts from 1st July 2012 to 31st December 2015 were included in a multivariable logistic regression model containing 25 different risk factors. Riding speeds in individual stages (‘loops’) were included as individual risk factors in studying the progress of horses through loops 1–3 of each endurance ride. The possibility of real-time, ‘mid-ride’ predictive modelling was explored by modelling both riding speeds and sudden changes in speed between loops as potential risk factors. Faster riding speeds, especially during loops 1 and 2, were associated with deleterious outcomes. Furthermore, sudden drops in riding speed during loop 3 were associated with an increased likelihood of elimination.

Switching Techniques and Intelligent Controllers for Induction Motor Drive: Issues and Recommendations

Induction motor drive is widely used in many load applications in approximately 60% of the total industrial load. However, the dynamic configuration of the induction motor, especially a three-phase induction motor (TIM) is a nonlinear system which is not easy to explain theoretically due to sudden changes in load or speed. Therefore, the development of variable speed drive with a robust switching technique and controller design is compulsory for improving the performance efficiency of the TIM. An advanced switching strategy is used for controlling voltage, frequency, and reducing harmonic output signals while an efficient controller is required to regulate currents, speed, torque, and rotor flux. Nevertheless, the development of such controllers and switching methods need the extensive mathematical model and complex online computation. This paper presents a critical review of the different switching techniques, switching pattern of voltage space vectors and switching time to solve the existing problems and enhance the performance of the TIM. Also, the paper describes the different intelligent controller techniques in terms of scalar control and vector control. Consequently, a comprehensive review on conventional controllers such as proportional integral derivative and artificial intelligence controllers such as an artificial neural network, adaptive neural fuzzy inference system, and fuzzy logic control are explained on their structure, algorithm, and mathematical model. Furthermore, the different integrated circuits of the TIM drive controller are reviewed along with benefits and limitations, current issues and challenges, and conclude with recommendations. All the highlighted insights of this review will hopefully lead to increased efforts toward the development of the advanced switching techniques and controllers for the future induction motor drive.

Transient response of the flexible blade of horizontal-axis wind turbines in wind gusts and rapid yaw changes

In this paper, the aeroelastic analysis of a large scale wind turbine rotor is performed with the aim of studying transient performance of turbine in extreme wind conditions, such as wind gusts and rapid yaw changes. The effect of the presence and/or lack of blade pitch control system on output power, rotor thrust, and blade deformation in sudden change of wind speed are investigated. The NREL 5 MW offshore wind turbine is used as the baseline case. In this regard, the modal approach is implemented for modeling the flexible blade structure with tension, bending and torsion degrees of freedom. The unsteady vortex lattice method is employed to obtain the aerodynamic loads. Moreover, the Lagrange equation is utilized to derive the governing dynamic equations and the yielded nonlinear system of equations is solved in time domain. Structure and aerodynamic models are validated by using standard cases. Wind turbine response to different scenarios for sudden change of wind speed and direction are investigated. The results show that the sudden change in wind speed leads to the emergence of overshoots (or undershoots) in output power as high as 40% (and 20%) for active pitch control case and nearly 25% and 20% gradual increment of thrust and tip deformations for inactive case. Time delay of recovering to the new steady-state output power is about 4 s (corresponding to one rotor revolution) and independent from the state of pitch control system. With sudden change of yaw angle, the turbine transient response gradually attains a new steady-state after a time delay of about 5 s. Moreover, results indicate that the output power and rotor thrust have a cyclical variation with the frequency of rotor rotation due to the asymmetric wake configuration.

Safe or unsafe driving maneuvers in road traffic

This article represents an area closely connected to the analysis of road accidents. When the act of accident is being considered by an expert, it often happens that one participant of the accident causes that the other participant has to change suddenly the speed or direction of his/her drive to prevent possible collision. For a proper consideration of the driving manoeuvres we need to know the limit of a sudden change of speed or a sudden change of direction of drive. The limit of suddenness can be taken as the limit between a safe and already unsafe driving manoeuvre (braking, transverse motion) of the vehicle. The author tried to settle this limit by measurements with respondents who were asked to subjectively classify particular driving manoeuvres. For classification of the sudden change of speed, the intensity of deceleration was altered (3 m/s2, 5 m/s2, 7 m/s2, and maximum attainable deceleration amax m/s2). At classifying a sudden change of direction, we changed the trajectory of the vehicle´s motion with transverse motion in one curve. As a result in the change of trajectory, the magnitude of side acceleration changed (values of side acceleration 2 m/s2, 3 m/s2, 4 m/s2 and 6 m/s2). From the results achieved it can be settled that the limit of a sudden change of vehicle´s speed went round a half of maximally achievable braking deceleration of personal vehicles, at approximately 3,8 to 4,8 m/s2. The limit of a sudden change of direction of drive went between 2,7 and 3,5 m/s2.of vehicles´ side acceleration. Achieved knowledge can be used in the sphere of road accident analysis when classifying driving manoeuvres of individual participants of the scene of accident. All measurements were taken with personal vehicles, thus it is possible to pay further attention to setting the limit of a sudden change of speed and direction of drive with utility vehicles, lorries and trucks, respectively.

A Novel Fuzzy Self Tuning Technique of Single Neuron PID Controller for Brushless DC Motor

In this paper, a combination ANN/Fuzzy technique is used to design a Novel Fuzzy Single Neuron PID (NFSNPID) controller to achieve high performance brushless DC motor. The design steps include two parts. The first part uses the genetic algorithm (GA) to find the optimum parameters of Single Neuron PID (SNPID) controller, while the former deals with the design of fuzzy logic control to update the weights of SNPID control online. To demonstrate the designed controller effectiveness, a comparative study is made with between the NFSNPID, Conventional Fuzzy Single Neuron PID CFSNPID and SNPID. All controllers were used to drive, separately, the brushless DC motor against the sudden change of load and operating speed. The performed simulations show better results that motivate for further investigations.

MASTER-SLAVES SPEED SYNCHRONIZATION OF TRIPLE 3-PHASE INDUCTION MOTORS USING PI AND PID CONTROL METHODS

This paper presents two methods used for three closed loop speed controller of Variable-Voltage Variable Frequency (VVVF) triple 3-phase Induction Motors (IMs) master/slaves system. A dynamic d-q model of a 3-phase IM in state space form and its computer simulation in MATLAB/SIMULINK software package are described. The two different methods of speed control which are used to improve the performance of three IMs drive system are named as conventional PI controller and PID controller. For PID speed controller, simulation results clearly show that the response of the system is superior compared to PI speed controller in terms of rise time, settling time, accuracy and steady state error. The design, analysis, and speed responses of the system obtained under both controllers have been simulated, studied and compared using MATLAB/Simulink environment for different operating conditions such as sudden change in reference speed and load torque. The simulation results showed good synchronization between the master and the slave IMs with suitable tracking error.

Modeling pedestrian crossing speed profiles considering speed change behavior for the safety assessment of signalized intersections

Pedestrian safety is one of the most challenging issues in road networks. Understanding how pedestrians maneuver across an intersection is the key to applying countermeasures against traffic crashes. It is known that the behaviors of pedestrians at signalized crosswalks are significantly different from those in ordinary walking spaces, and they are highly influenced by signal indication, potential conflicts with vehicles, and intersection geometries. One of the most important characteristics of pedestrian behavior at crosswalks is the possible sudden speed change while crossing. Such sudden behavioral change may not be expected by conflicting vehicles, which may lead to hazardous situations. This study aims to quantitatively model the sudden speed changes of pedestrians as they cross signalized crosswalks under uncongested conditions. Pedestrian speed profiles are collected from empirical data and speed change events are extracted assuming that the speed profiles are stepwise functions. The occurrence of speed change events is described by a discrete choice model as a function of the necessary walking speed to complete crossing before the red interval ends, current speed, and the presence of turning vehicles in the conflict area. The amount of speed change before and after the event is modeled using regression analysis. A Monte Carlo simulation is applied for the entire speed profile of the pedestrians. The results show that the model can represent the pedestrian travel time distribution more accurately than the constant speed model.

Consideration of a Pedestrian Speed Change Model in the Pedestrian–Vehicle Safety Assessment of Signalized Crosswalks

Pedestrian safety is one of the most challenging issues in the road network. Understanding the pedestrian maneuver is the key to applying countermeasures against traffic crashes. It is known that behaviors of pedestrians at signalized crosswalks are significantly different from ordinary walking spaces and they are highly influenced by signal indication, potential conflicts to vehicles and intersection geometries. One of the most important characteristics of pedestrian behavior at crosswalks is the possible sudden speed change while crossing. Such sudden behavioral change may not be expected by conflicting vehicles, which may lead to hazardous situations. This study aims to quantitatively model the pedestrians' sudden speed change maneuver at signalized crosswalks under uncongested conditions. Pedestrian speed profiles are collected from empirical data and speed change events are extracted assuming that the speed profiles are stepwise functions. The occurrence of the speed change events is described by a discrete choice model as a function of the necessary walking speed to complete crossing before red interval, current speed, and the presence of turning vehicles in the conflict area. The amount of speed change before and after the event is modeled using regression analysis. A Monte- Carlo simulation is applied for the entire speed profile of the pedestrians. The results showed that the model was able to represent the pedestrian travel time distribution more accurately than the constant speed model.

PARTICLE FILTER-BASED OBJECT TRACKING USING JOINT FEATURES OF COLOR AND LOCAL BINARY PATTERN HISTOGRAM FOURIER

Object tracking is defined as the problem of estimating object location in image sequences. In general, the problems of object tracking in real time and complex environtment are affected by many uncertainty. In this research we use a sequensial Monte Carlo method, known as particle filter, to build an object tracking algorithm. Particle filter, due to its multiple hypotheses, is known to be a robust method in object tracking task. The performances of particle filter is defined by how the particles distributed. The role of distribution is regulated by the system model being used. In this research, a modified system model is proposed to manage particles distribution to achieve better performance. Object representation also plays important role in object tracking. In this research, we combine color histogram and texture from Local Binary Pattern Histogram Fourier (LBPHF) operator as feature in object tracking. Our experiments show that the proposed system model delivers a more robust tracking task, especially for objects with sudden changes in speed and direction. The proposed joint feature is able to capture object with changing shape and has better accuracy than single feature of color or joint color texture from other LBP variants.

Studying critical pedestrian behavioral changes for the safety assessment at signalized crosswalks

Pedestrian-vehicle conflicts are one of the most important safety concerns at signalized intersections especially in urban areas. Conflicting vehicles and pedestrians select their maneuvers by predicting the other user behavior. Sudden behavioral changes of pedestrians such as sudden speed change (acceleration or deceleration) cannot be predicted by drivers, which can lead to safety hazards especially if these sudden behavioral changes occur near conflict areas. In this study, continuous pedestrian speed profiles were analyzed at signalized crosswalks to investigate the existence of such behavioral changes. A methodology is proposed to identify significant sudden changes of pedestrian speeds. The locations and timings of these sudden speed change events were analyzed, and the influencing factors such as crosswalk geometry and signal timing were studies and evaluated. Five signalized crosswalks at three intersections in Nagoya City were videotaped for analysis. Individual pedestrian maneuvers were extracted with image processing software. Empirical analysis showed that sudden acceleration events were observed at the entrance points to the pedestrian-vehicle conflict area, which highlights the significance of these events to pedestrian-vehicle conflict analysis. A multinomial logit model was developed to estimate the probability of a pedestrian making a sudden speed change as a function of different influencing factors. The results implied that the entering speed, necessary speed to finish crossing before the onset of the pedestrian signal red phase, and crosswalk length have a significant impact on speed change choices. This paper presents important suggestions to understanding pedestrian maneuvers in detail from the viewpoint of safety.

Evaluation of variable advisory speed limits in congested work zones

ABSTRACTThe effectiveness of variable “advisory” speed limit (VASL) systems in congested urban work zones was investigated. Except for one publication, all previous studies focused on regulatory speed limit systems. This study used a comprehensive set of performance measures to investigate VASL effectiveness. Four congested work zones with lanes reduced from four to three lanes on Interstate 270 in St. Louis, Missouri, were selected for empirical and simulation analysis. The empirical analysis showed that VASL were effective in slowing down drivers gradually as they approached the work zone, thus reducing any sudden speed changes. Simulation analysis showed that operationally, the use of VASL resulted in: a 39% to 53% decrease in average queue length, a 7% to 11% reduction in throughput, a 4% to 8% increase in travel time. The use of VASL achieved a decrease in the standard deviation of speeds at the taper and 1-mile upstream of the work zone. The maximum speed differences also decreased up to 10 mph with VASL. A new VASL algorithm investigated in the study showed significant improvements in mobility and safety performance compared to the original field algorithm. The new algorithm made promising improvements in safety—a 30% reduction in rear-end conflicts and a 20% reduction in lane changing conflicts as compared to the without VASL condition. The new VASL algorithm also decreased the queue length, further improving the overall safety in congested work zones. Thus, it is possible to design a VASL system that improves traffic and safety in congested work zones.

Rotor-flux-based MRAS speed estimator for DTFC-SVM of a speed sensorless induction motor drive using Type-1 and Type-2 fuzzy logic controllers over a wide speed range

Summary In this research study, Type-1 and Type-2 fuzzy logic controller-based model reference adaptive system speed estimator for direct torque and flux control with space vector modulation of a speed sensorless induction motor drive is proposed to replace the conventional proportional-integral controller. Initially, Type-1 fuzzy logic controller is developed, which is used to achieve high performance sensorless drive in both transient as well as steady state conditions. However, the Type-1 fuzzy sets are certain and unable to work effectively when higher degree of uncertainties in the system which can be caused by sudden change in speed or different load torque disturbances, process noise, etc. Therefore, a new Type-2 fuzzy logic controller-based adaptation scheme is proposed to better handle the higher degree of uncertainties along with enhancing the performance and also robust to various load torque and sudden change in speed conditions respectively. The detailed performances of various control schemes are carried out in MATLAB/SIMULINK with speed sensor and sensorless modes of operation when an induction motor drive is operating under different conditions, such as no-load, load, sudden change in speed and low speed respectively. To validate the different control approaches, an experimental prototype is developed and adequate results are reported for its validation. Superior performance has been obtained using the Type-2 fuzzy logic controller scheme in speed sensor and sensorless modes of operation compared with Type-1 fuzzy logic controller and proportional-integral controller based adaptation schemes respectively. Copyright © 2016 John Wiley & Sons, Ltd.

Vibrational and reorientational dynamics, crystal structure and solid–solid phase transition studies in [Ca(H2O)6]Cl2 supported by theoretical (DFT) calculations

[Ca(H2O)6]Cl2 between 93 and 300 K possesses two solid phases. One phase transition (PT) of the first‐order type at = 218.0 K (on heating) and = 208.0 K (on cooling) was determined by differential scanning calorimetry. Thermal hysteresis of this PT (10 K), as well as the heat flow anomaly sharpness, suggests that the detected PT is a first‐order one. The entropy change value [ΔS ≈ 8.5 J mol−1 K−1 ≈ Rln(2.8)] associated with the observed PT suggests a moderate degree of molecular dynamical disorder of the high‐temperature phase. The temperature dependencies of the full width at half maximum values of the infrared band are due to ρ(H2O)A2 mode (at 205 cm−1), and two Raman bands are arising from τ(H2O)E and τ(H2O)A1 modes (at ca. 410 and 682 cm−1, respectively), suggesting that the observed PT is associated with a sudden change of speed of the H2O reorientational motions. The estimated mean value of activation energy for the reorientation of the H2O ligands in the high‐temperature phase is ca. 11.4 kJ mol−1 from Raman spectroscopy and 11.9 kJ mol−1 from infrared spectroscopy. X‐ray single‐crystal diffraction measurement and spectroscopic studies (infrared, Raman and inelastic neutron scattering) also confirm that [Ca(H2O)6]Cl2 includes two sets of differently bonded H2O molecules. Ab initio calculations of the complete unit cell of one molecule of calcium chloride with a different number of water molecules (2, 4 and 6) have also been carried out. A comparison of Fourier Transform Infrared (FT‐IR), Fourier Transform Raman Scattering (FT‐RS) and inelastic neutron scattering spectroscopies results with periodic density functional theory calculations was used to provide a complete assignment of the vibrational spectra of [Ca(H2O)6]Cl2. Copyright © 2016 John Wiley & Sons, Ltd.

A study on crossing speed profiles of pedestrians at signalized crosswalks

Pedestrian–vehicle conflicts are one of the most important safety concerns especially at intersections. Of total traffic fatalities, 30% and 36% are pedestrians in Qatar and in Japan, respectively (National Police Agency in Japan, 2015). Although pedestrians at signalized intersections are given priority during the green phase, turning vehicles in conflict often do not give the right of way to pedestrians but tend to compete for it. Furthermore, long crosswalks, short green times, and other reasons may cause pedestrians to rush or suddenly change their speed without paying attention to the surrounding conditions (Iryo-Asano et al. 2014). The sudden changes in pedestrian behavior while crossing cannot be predicted by the driver, which can cause severe conflicts. Therefore, the possible behavioral changes of pedestrians should be studied so that surrogate safety measures such as post-encroachment time can be quantitatively estimated to provide a reliable assessment of pedestrian–vehicle conflicts and their severities. Continuous pedestrian speed profiles were analyzed at signalized crosswalks considering the impact of crosswalk geometry and signal timing. Five signalized crosswalks at three intersections in Nagoya City were videotaped and individual pedestrian maneuvers were extracted by image processing. A stepwise speed function is proposed to identify significant sudden changes in individual pedestrian speed profiles. The locations and timings of these sudden speed change events were analyzed, and the influencing factors were statistically evaluated. Empirical analysis showed that sudden acceleration events were observed at the entrance points to the pedestrian–vehicle conflict area, which highlights the significance of these events to pedestrian–vehicle conflict analysis. More than a quarter of all acceleration events occurred just after the onset of the pedestrian flashing green signal indication. Furthermore, it is concluded that long crosswalks have higher percentage of speed change occurrence and as a result higher risk of crashes. In this regard, the application of two-stage pedestrian crossing is a potential solution to reduce crosswalk length and the possibility of having unpredicted pedestrian behavioral changes. In general, the results implied that pedestrian entering speed to crosswalk, necessary speed to finish crossing before the onset of the pedestrian red signal indication, and crosswalk length have a significant impact on pedestrian speed change choices.

MRAS Speed Estimator Based on Type-1 and Type-2 Fuzzy Logic Controller for the Speed Sensorless DTFC-SVPWM of an Induction Motor Drive

This paper presents model reference adaptive system speed estimators based on Type-1 and Type-2 fuzzy logic controllers for the speed sensorless direct torque and flux control of an induction motor drive (IMD) using space vector pulse width modulation. A Type-1 fuzzy logic controller (T1FLC) based adaptation mechanism scheme is initially presented to achieve high performance sensorless drive in both transient as well as in steady-state conditions. However, the Type-1 fuzzy sets are certain and cannot work effectively when a higher degree of uncertainties occurs in the system, which can be caused by sudden changes in speed or different load disturbances and, process noise. Therefore, a new Type-2 FLC (T2FLC) - based adaptation mechanism scheme is proposed to better handle the higher degree of uncertainties, improve the performance, and is also robust to different load torque and sudden changes in speed conditions. The detailed performance of different adaptation mechanism schemes are performed in a MATLAB/Simulink environment with a speed sensor and sensorless modes of operation when an IMD is operates under different operating conditions, such as no-load, load, and sudden changes in speed. To validate the different control approaches, the system is also implemented on a real-time system, and adequate results are reported for its validation.

P146 – 2496: Clinical and genetic profile of two families with paroxysmal dyskinesia

Objective Paroxysmal dyskinesia (PD) may present heterogeneous clinical features. Recent molecular studies have led to a new classification. We describe the different clinical and genetic features of two families with PD. Methods Clinical and genetic features description of two families with PD, from an index case. Results Case 1: a 5-year-old girl was diagnosed of occipital benign epilepsy at 5 months. From two years old she presented frequent paroxysms of choreoathetosis movements of lower limbs and facial dyskinesia lasting 5 minutes, mostly triggered by physical exertion or tiredness. She also suffered episodes of acute ataxia lasting several weeks. Her IQ was low average, with attention deficit. Her father had episodes of hemiplegic migraine triggered by exercise. Molecular study revealed 649dpC mutation (PRRT2 gen, 2nd exon), Paroxysmal Kinesigenic Dyskinesia (PKD). Currently she is partially controlled with carbamazepine. Case 2: a 3-year-old girl presented with attacks of hypotonia, left upper limb dystonic movements and drowsiness lasting 20 minutes, triggered by tiredness. Her mother was diagnosed with Paroxysmal Nonkinesigenic Dyskinesia (PNKD) and several mother's family members where also affected. Familial molecular study showed p.Ala7Val mutation (PNKD gen, 1st exon, 20 position). She was controlled with diazepam and remained asymptomatic. Conclusion PD is a heterogeneous group of diseases in which clinical characteristics and family history are critical for the diagnosis. PRRT2 mutations are responsible of PKD symptoms, induced by sudden movements or speed changes, but can also cause hemiplegic migraine, episodic ataxia and benign infantile seizures. Mutations on PNKD gen are linked to symptoms triggered by caffeine, alcohol, stress or fatigue.

Enforcement avoidance behavior near automated speed enforcement areas in Korean expressways

Automated speed enforcement system (ASES) has been deployed as a safety countermeasure on Korean roadways to reduce speeding-related traffic crashes; information on ASES locations is mandated to be open to the public. However, because drivers are alerted about enforcement via on-board navigation systems and roadside signs, they can avoid enforcement by momentarily reducing their speeds near ASES locations. This enforcement avoidance behavior (EAB) can induce sudden changes in speed near the enforcement locations and thereby increase risk of crash occurrence.In light of this situation, the present study evaluates the effects of ASES on traffic behavior and safety. An analysis of traffic data shows that drivers indeed diminish their speeds near enforcement locations, and accelerate shortly after passing the locations. To investigate how this behavior affects safety performance, this study, by using Empirical Bayes analysis with comparison groups, compares crash occurrences along a certain section before and after the installation of ASES. The comparative analysis shows that overall crash occurrence dropped by 7.6% on average near the enforcement locations, although the reduction was not significant. However, an average 11% non-significant increase in crash occurrence is also observed in the upstream segment, where enforcement is announced to drivers and traffic starts to diminish speed.The findings suggest that the sudden changes in traffic speed induced by EAB substantially negate the benefits of ASES. Therefore, modification of the design of current ASES is required to mitigate EAB and further improve the effectiveness of ASES.