scholarly journals A Method of Speed Control during Over-Ground Walking: Using a Digital Light-Emitting Diode Light Strip

2013 ◽  
Vol 718-720 ◽  
pp. 1371-1376 ◽  
Author(s):  
Liang Huang ◽  
Jie Zhuang ◽  
Yan Xin Zhang
Keyword(s):  
Walking Speed ◽  
Light Emitting Diode ◽  
Speed Control ◽  
Visual Cue ◽  
Light Emitting ◽  
Custom Made ◽  
Percent Difference ◽  
Average Percent Difference ◽  
Walking Speeds ◽  
Over Ground Walking

The purpose of this report was to introduce the design of a portable, inexpensive and programmable digital light-emitting diode (LED) system to control overground walking speed. The system includes a custom-made 10 meters digital LED strip and a digital microcontroller. By controlling the duration time of the power supply to each LED unit, a visible running lights signal can provide a visual cue for speed control. To evaluate this design, five subjects were asked to walk overground while following the LED visual cue at five different target speeds. The actual walking speeds were determined using Vicon motion capture system. The results of this evaluation showed a good match between the actual and desired speeds. The average percent difference was 2.51%, measured over 250 walking trials by the subjects. 98% of trials had an percent difference smaller than 6.5%, which is the maximum tolerated error within the literature. The inter-trial reliability for the LED speed control system ranged from 0.85 to 0.88 for faster speeds (1.6 m/s, 1.4 m/s), and slightly lower ranging from 0.74 to 0.79 at slower speeds (1.2 m/s, 1.0 m/s, 0.8 m/s).

Optimization and evaluation of a blue light photoinitiating system for textile inkjet printing

2018 ◽  
Vol 89 (10) ◽  
pp. 1964-1974
Author(s):  
Yi Huang ◽  
Guangdong Sun ◽  
Yating Ji ◽  
Dapeng Li ◽  
Qinguo Fan ◽  
...  
Keyword(s):  
Blue Light ◽  
Light Emitting Diode ◽  
Absorption Efficiency ◽  
Polymerization Rate ◽  
Nozzle Clogging ◽  
Light Emitting ◽  
Custom Made ◽  
Light Curing ◽  
Set Up ◽  
Pigment Ink

A blue light curing process was developed to solve the nozzle clogging challenge commonly encountered in conventional textile pigment printing, by using camphorquinone (CQ) and ethyl-4-dimethylaminobenzoate (EDMAB) as a photoinitiator combination and substituting oligomers and monomers for a polymeric binder. High light absorption efficiency was insured by closely matching the spectrum of the photoinitiator with a custom-made blue light light-emitting diode set-up. Kinetic analyses of such a CQ/EDMAB system indicated that the maximum polymerization rate of the monomer was proportional to [PI]0.5 and [I0]0.5, while excessive high photoinitiator concentration (>1 wt%) will decrease the polymerization rate because of the “filter effect.” With optimized blue light curable pigment ink formula and irradiation conditions, the photocurable pigment printed fabrics exhibited uniform and vibrant colors, clear outlines, and excellent wet and dry rubbing fastness of grades 4 and 4–5, respectively.

scholarly journals Drosophila uses a tripod gait across all walking speeds, and the geometry of the tripod is important for speed control

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Chanwoo Chun ◽  
Tirthabir Biswas ◽  
Vikas Bhandawat
Keyword(s):  
Simple Model ◽  
Spatial Resolution ◽  
Inverted Pendulum ◽  
Walking Speed ◽  
High Spatial Resolution ◽  
Center Of Mass ◽  
Mass Movement ◽  
Speed Control ◽  
Tripod Gait ◽  
Walking Speeds

Changes in walking speed are characterized by changes in both the animal’s gait and the mechanics of its interaction with the ground. Here we study these changes in walking Drosophila. We measured the fly’s center of mass movement with high spatial resolution and the position of its footprints. Flies predominantly employ a modified tripod gait that only changes marginally with speed. The mechanics of a tripod gait can be approximated with a simple model – angular and radial spring-loaded inverted pendulum (ARSLIP) – which is characterized by two springs of an effective leg that become stiffer as the speed increases. Surprisingly, the change in the stiffness of the spring is mediated by the change in tripod shape rather than a change in stiffness of individual legs. The effect of tripod shape on mechanics can also explain the large variation in kinematics among insects, and ARSLIP can model these variations.

Assessing Retinal Hazardous Effects from Phosphor Converted Light Emitting Diode (LED) Lighting with Different Correlated Color Temperature (CCT)

2017 ◽  
Vol 730 ◽  
pp. 112-118 ◽  
Author(s):  
Yu Man Shang ◽  
Li Ling Lee ◽  
Jung Min Hwang ◽  
Gen Shuh Wang ◽  
Chin Pao Cheng
Keyword(s):  
White Light ◽  
Cell Damage ◽  
Light Emitting Diode ◽  
Neuronal Cell ◽  
Color Temperature ◽  
Light Emitting ◽  
Retinal Injury ◽  
Transmission Electron ◽  
Custom Made ◽  
User Friendly

Due to the rapid growth in the use of blue-light-based electrical panels and much brighter lighting environments, the socioeconomic impact by retinal light injury is critical. Understanding the material property and mechanisms underlying this hazard is important for both effective and user-friendly product development. The InGaN based blue LED has been applied to excite the yellow phosphor (Y3Al5O12:Ce3+) for white light generation. In this study, custom-made phosphor-converted white light emitting diode (pc-WLED) with correlated color temperature (CCT) ranging from 2700K to 6500K were used for exposure treatments to assess the potential retinal injury. We examined LED induced retinal neuronal cell damage in a rat model through functional and histopathological measurements. Electroretinography (ERG), hematoxylin and eosin (H&E) staining, and transmission electron microscopy (TEM) were used for pathological examinations. The experimental results indicate that blue-rich-LED light could induce more photochemical injury to the retina after the exposure. The results of this study suggest that retinal injury is mainly induced by photosensitizer-and photopigment-mediated oxidative stress with color temperature dependent effect, and users should be more aware of this effect before switching to LED lamps for domestic lighting.

Synchronization of Chaotic Quantum Dot Light Emitting Diodes under Optical Feedback Effect

2020 ◽  
pp. 144-148
Keyword(s):  
Quantum Dot ◽  
Delay Time ◽  
Chaos Synchronization ◽  
Optical Feedback ◽  
Light Emitting Diode ◽  
Feedback Effect ◽  
Complete Synchronization ◽  
Light Emitting ◽  
Coupling Methods ◽  
Coupling Parameters

Chaos synchronization of delayed quantum dot light emitting diode has been studied theortetically which are coupled via the unidirectional and bidirectional. at synchronization of chaotic, The dynamics is identical with delayed optical feedback for those coupling methods. Depending on the coupling parameters and delay time the system exhibits complete synchronization, . Under proper conditions, the receiver quantum dot light emitting diode can be satisfactorily synchronized with the transmitter quantum dot light emitting diode due to the optical feedback effect.

Effects of Nitridation Time on Top-emission Inverted Organic Light Emitting Diode

PIERS Online ◽  
2007 ◽  
Vol 3 (6) ◽  
pp. 821-824 ◽  
Author(s):  
Chien-Chang Tseng ◽  
Liang-Wen Ji ◽  
Yu Sheng Tsai ◽  
Fuh-Shyang Juang
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Nitridation Time ◽  
Organic Light
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