Littérature scientifique sur le sujet « Mp4 converter online »

Background: Health literacy is importantly recognized to combat the increasing incidence of kidney disease in the community and kidney health for all campaigns. Various kinds of digital platforms and tools are used to bridge the gap in health literacy to improve kidney health. Fifty percent of the world population is devoid of internet connection or poor connectivity. Digital library plays a vital role in digital literacy and this present study is done to see if sever specially designed can work without the internet with digital library software. Methods: A specially designed server that can connect with a digital device along with a regular internet-based server was loaded with digital library software. Devices with regular browsers were to access the server with the web address juxtaguide.com. Users included the admin who had full control over the device and other users were divided into teachers group I N = 25 for online and group II, N = 20 for offline study, and they were allowed to upload various format digital files for their students to access. Students in the study group were n = 250 online and n = 80 in an offline group. They were assessed if they can access the digital material, search and also participate in chat functions with their teachers. Links were shared through social media for online mode. Results: Teachers in both offline and online mode were able to access the server register and upload files in all formats like mp3, mp4, PDF, documents, links, blogs, and images, using digital device including laptops or mobile phones. Students were able to communicate in the offline mode similar to the online mode with various digital devices. The offline server was portable and could run on a backup inverter power source and could run continuously with a hot spot range of 50 meters. The upload and download speed for the offline version was not affected whereas in the online mode, when in 2G the internet was of low speed, bigger files were not downloadable. The maintenance cost of the offline server was minimal compared to the online server. Discussion: For the first time in the world, a server was converted to function in the offline mode, having the ability to synchronize with an online server that holds the same digital library software. All criteria of a digital library were full filled. In the offline mode, the device was also successful in two- way communication which no one could achieve to date. Conclusion: DigiNet as a digital library device fulfills all requirements to be a cost-effective device for offline literacy development. It also gives new hope to surpass not only the health literacy barrier but also opens huge potential for its use in future research and education. Further research is to be conducted with regards to the extension of its range up to 12 km.

The regenerative Tuned Mass Damper (TMD) can convert the vibration energy of the tall building into the electricity, by replacing the damping element with electromagnetic harvester. The energy harvesting circuit therein which can regulate the electricity and control the vibration will introduce some constraints when designing vibration controller. This paper designed the vibration controller based on Model Predictive Control (MPC). The control force constraints were taken into consideration before designing the controller. The building model with semi-active constraints due to the regenerative properties of the TMD is converted into a Mixed Logical Dynamical (MLD) system first. Then the optimal controller is designed by solving the Mixed Integer Quadratic Programming (MIQP) problem. The results were evaluated and compared to the ones using “clipped-optimal” controller with the same constraints. It is found that the MPC controller can provide the same or better vibration control Results depending on the predicted horizon. Besides, an explicit MPC is obtained to reduce the online computation effort.

Multi-string configuration is commonly seen in practical photovoltaic (PV) applications, to secure the Maximum Power Point (MPP) for each string, individual string is equipped with its own DC-DC converter for voltage regulation. This study presents an integrated framework that achieves dual purposes simultaneously: maximum power point tracking (MPPT) control and detection of the change in internal resistance. An multi-channel extremum seeking control (ESC) strategy is developed to maximize the power output of multi-string PV system by regulating the voltage input to the DC-DC converter, overall MPPT can be obtained by delivering the power from strings to the DC bus. Simulation results show that the ESC can achieve multi-string overall MPPT with periodic dither signals such as sinusoidal and square wave signals. As change in internal resistance is coupled with many degradation factors for the PV cell, e.g. increase in the series resistance and decrease in the shunt resistance, the capability of integrated detection of internal resistance can be used as a diagnostic probe for PV online diagnostics. Square Wave ESC dither signal is a useful tool to detect the change of internal resistance as the rise time or settling time on a square wave rising edge is more amplified with internal change of a PV system. Therefore, the voltage output transient under square-wave dithering can be changed remarkably with degradation induced change of internal resistance. Simulation results have also confirmed such correlation. The ESC with square wave dithering can thus provides the dual benefits of MPPT and internal resistance change simultaneously.

<div class="section abstract"><div class="htmlview paragraph">This paper proposed a model predictive control(MPC) based car-following control strategy for electric vehicles considering comfort, in order to improve the comfort of the car-following control system of electric vehicles. The MPC algorithm is improved in the following three aspects to improve the comfort: Firstly, a five-state longitudinal car-following model is adopted, so that the MPC algorithm can optimize the acceleration and acceleration change rate of the ego vehicle. Secondly, for the weight coefficients of the output vector and the input vector of the objective function, the fixed weight coefficients are changed into variable weight coefficients by the way of Nash equilibrium game, so that the control system can improve the weight of the parameters used to control the comfort under suitable driving conditions. Finally, The NGSIM natural driving data set is used to change the fixed constraint on acceleration into the variable constraint that follows the velocity change, so as to avoid the impact of emergency acceleration and deceleration on comfort. The improved MPC algorithm continuously calculates the desired acceleration of the ego vehicle at the current moment through online rolling optimization, than transmits it to the lower-level controller. Due to the type of controlled vehicle is changed from fuel vehicle to electric vehicle, the motor model is used in the lower-level controller to replace the engine model. The control signal of the upper-level controller is converted into the desired motor torque or the desired braking pressure in the lower-level controller. The simulation results show that, on the basis of ensuring the safety and tracking capability, the fluctuation range of acceleration is reduced by 24.4% and the standard deviation of acceleration is reduced by 12.5% compared with the basic MPC algorithm. At the same time, the sudden change of acceleration is eliminated. Thus the comfort of the car-following process is significantly improved.</div></div>