Dynamic Time Control Research Articles

Multidimension‐Regulated Dynamic Timing Control Over Multicolor Emission of Host–Guest Assemblies for Information Encryption and Advanced Anti‐Counterfeiting

AbstractDynamical control over molecular luminescence, especially in a time‐dependent manner, holds great promise for the development of smart luminescent materials for anti‐counterfeiting and preventing information leakage. Herein, a series of self‐assembled systems are reported using pillar[5]arene (DMP[5]) and spiropyran derivatives (SP‐C4‐Py). The assemblies rely on the time‐encoded locking and unlocking ring‐switching and fluorescence resonance energy transfer (FRET) units for information camouflage and multilevel encryption. DMP[5] with cyan solid fluorescence color acts as the host and energy transfer (EnT) donor, while photochromic SP‐C4‐Py with the ring‐opened and closed isomers acts as guest and EnT acceptor. When irradiated, the assemblies undergo a time‐dependent luminescence color change ranging from cyan to yellow to red through a FRET process. The molar ratio of host and guest in the assembly systems affects the FRET efficiency, and the power of the irradiation source influences the isomerization degree and rate of SP‐C4‐Py, allowing for precise control over the fluorescent color transition time. The combination of molecular composition and external stimuli governs the kinetics of color change, resulting in a difference in the appearance time of a specific fluorescent color pre‐designed as correct authorized information. By combining these diverse assembles in one label, information encryption and dynamic information identification are achieved in the dimensions of time, ratio, and light power. This time‐dependent feature offers the assembly materials with a multilevel security and provides new possibilities for anti‐counterfeiting and blocking information leakage.

Dynamic Timing Control over Multicolor Molecular Emission by Temporal Chemical Locking

AbstractDynamic control over molecular emission, especially in a time‐dependent manner, holds great promise for the development of smart luminescent materials. Here we report a series of dynamic multicolor fluorescent systems based on the time‐encoded locking and unlocking of individual vibrational emissive units. The intramolecular cyclization reaction driven by adding chemical fuel acts as a chemical lock to decrease the conformational freedom of the emissive units, thus varying the fluorescence wavelength, while the resulting chemically locked state can be automatically unlocked by the hydrolysis reaction with water molecules. The dynamic molecular system can be driven by adding chemical fuels for multiple times. The emission wavelength and lifetime of the locking states can be readily controlled by elaborating the molecular structures, indicating this strategy as a robust and versatile way to modulate multi‐color molecular emission in a time‐encoded manner.

Dynamic Timing Control over Multicolor Molecular Emission by Temporal Chemical Locking

Dynamic control over molecular emission, especially in a time-dependent manner, holds great promise for the development of smart luminescent materials. Here we report a series of dynamic multicolor fluorescent systems based on the time-encoded locking and unlocking of individual vibrational emissive units. The intramolecular cyclization reaction driven by adding chemical fuel acts as a chemical lock to decrease the conformational freedom of the emissive units, thus varying the fluorescence wavelength, while the resulting chemically locked state can be automatically unlocked by the hydrolysis reaction with water molecules. The dynamic molecular system can be driven by adding chemical fuels for multiple times. The emission wavelength and lifetime of the locking states can be readily controlled by elaborating the molecular structures, indicating this strategy as a robust and versatile way to modulate multi-color molecular emission in a time-encoded manner.

Dynamic combination control of phase movement at signal intersection under the automated vehicle environment

With the continuous perfection of the technology of automated vehicles (AV), data exchange can be conveniently carried out between different vehicles and infrastructures, which makes it easier to collect different types of traffic parameters. Therefore, under AV environment, the vehicle status can be determined to obtain the periodic arrival rate of movements and a more efficient control strategy can be designed. The combination styles of phase movement (PM), an important factor of the signal control, will also become more complicated for intersection signal control. The current methods about the PM combination styles only considered two kinds of movement combination styles, and cannot get the extensive phase combination (PC) schemes in AV environment. This paper documents a new PM combination method by fractionalized movement compatibility relations, and uses discrete mathematics to calculate overall PC schemes. Then, a PM dynamic combination control method is proposed to optimize cyclically signal control. The analysis results of numerical tests showed that the average vehicle of the proposed method is reduced by 6.9 % and 14.5 % for 20 signal cycles, respectively, and the total throughput can be increased by 4.3% and 7.8%, respectively, compared with the dynamic timing control mode and the fixed control mode. Results show that the proposed method could significantly improve intersection control effectiveness.

Dynamic Traffic Light Timing Control System using Fuzzy TOPSIS Algorithm

Intelligent Traffic Light System with Dynamic timing control employs sensor and algorithm that has been design to solve the original problem of ordinary traffic light which is applied static timing for vehicle traffic flow control. Therefore to build a dynamic traffic light timing control system an algorithm and a sensor is a must. In this paper we proposed a Fuzzy TOPSIS algorithm to be used for traffic light timing control system based on real time quantity vehicle and vehicle classification. Using Fuzzy TOPSIS algorithm we can sets priority vehicle based on its parameter (in this paper we set to vehicle length). We can determine that the trailer truck gets more prioritize based on its length, the second priority would be bus, and the third one was car. Also using its coefficient we found the timing for each vehicle. For every trailer truck the timing would be 2.771552 seconds, for every bus the timing would be 2.581965 seconds and for every car would be 1.862602 second.

Design of On-Chip Gate Drivers With Power-Efficient High-Speed Level Shifting and Dynamic Timing Control for High-Voltage Synchronous Switching Power Converters

Two integrated high-speed gate drivers to enable high-frequency operation of synchronous rectifiers in high-voltage switching power converters are presented in this paper. The first synchronous gate driver for a CMOS power train consists of a capacitively coupled level shifter (CCLS) that offers negligible propagation delays and no static current consumption, and requires only one off-chip capacitor to enable high-side power pMOS driving capability without any external floating supply. The second synchronous gate driver consists of a low-power high-speed dynamically controlled level shifter (DCLS) with a reliability-enhanced error-suppression technique for driving a dual-nMOS power train. In addition, a dynamic timing control (DTC) is developed to generate proper dead time for power FETs in order to enable soft switching operation of the converter under different input voltages for enhancing the converter reliability. The converter power efficiency can be also improved by minimizing both switching and short-circuit power losses under high-input-voltage conditions. Implemented in a 0.5 µm 120 V CMOS process, both proposed CCLS and DCLS have demonstrated to shift up 5 V signal to 100 V and 40 V, respectively, improving the FoM by at least 10 times and 2.9 times compared to respective state-of-the-art level shifters. The DTC circuit enables proper ZVS operation in a synchronous buck converter with the CCLS-based gate driver over a wide input supply range from 40 V to 100 V, providing a converter maximum power-efficiency improvement of 11.5%.

A Dynamic Timing Error Prevention Technique in Pipelines With Time Borrowing and Clock Stretching

This paper presents a dynamic timing control technique to prevent timing errors in a pipeline under variations. Timing errors in a pipeline are prevented by borrowing time from the following stage and resolving the borrowed time by stretching the next clock cycle. This paper analyzes the operating principles of the proposed technique; presents the design of the required circuit components; and demonstrates its operation through fabrication and measurement of a prototype test-chip designed in an 180 nm CMOS process. The measurement results demonstrate that a system employing the dynamic timing control technique can operate in a wider frequency and voltage range.