Spectral power distribution deconvolution scheme for phosphor-converted white light-emitting diode using multiple Gaussian functions.

Appl Opt

Mechanical Engineering Department, University of Maryland, College Park, Maryland 20742, USA.

Published: February 2013

We propose a procedure to deconvolute the spectral power distribution (SPD) of phosphor-converted LEDs (pc-LEDs). The procedure involves a two-step process using multiple Gaussian functions. The first step is a preliminary process to deconvolute an SPD using a pair of Gaussian functions. Using the results from the first step, the second step determines (a) the number of Gaussian functions to be used in the analysis and (b) the initial values and regression domains of the coefficients of each Gaussian function for subsequent multiple-regression operations. Successful deconvolution is confirmed by comparing the values of lumen, correlated color temperature, and color rendering index with the experimental data of cool and warm pc-LEDs. The proposed approach is illustrated to evaluate the yellow-to-blue ratio and the phosphor power conversion efficiency.

Download full-text PDF

Source
http://dx.doi.org/10.1364/AO.52.001016DOI Listing

Publication Analysis

Top Keywords

gaussian functions
16
spectral power
8
power distribution
8
multiple gaussian
8
functions step
8
gaussian
5
distribution deconvolution
4
deconvolution scheme
4
scheme phosphor-converted
4
phosphor-converted white
4

Similar Publications

Basic Science and Pathogenesis.

Alzheimers Dement

December 2024

Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA.

Background: Genome-wide association studies (GWAS) in Alzheimer's disease (AD) leveraging endophenotypes beyond case/control diagnosis, such as brain amyloid β pathology, have shown promise in identifying novel variants and understanding their potential functional impact. In this study, we leverage two brain amyloid β pathology measurement modalities, PET imaging and neuropathology, to address sample size limitations and to discover novel genetic drivers of disease.

Method: We conducted a meta-analysis on an amyloid PET imaging GWAS (N = 7,036, 35% amyloid positive, 53.

View Article and Find Full Text PDF

Background: SMOC1 has recently emerged as one of the most significant and consistent new biomarkers of early Alzheimer's disease (AD). SMOC1 is one of the earliest changing proteins in AD, with SMOC1 cerebrospinal fluid levels increasing 29 years before symptom onset in autosomal dominant AD. Despite this clear association with disease, very little is known about the role of SMOC1 in AD or its function in the brain.

View Article and Find Full Text PDF

Background: Mitochondria plays a crucial role at synapses in providing synaptic energy, healthy synaptic function, and cognitive functions. Amyloid-beta and phosphorylated tau protein oligomers cause severe mitochondrial defects in Alzheimer's disease (AD), which leads to the lack of synaptic energy and impaired synapse functions in AD. MicroRNAs (miRNAs) present within the mitochondria are involved in multiple mitochondrial activities and mitochondrial function.

View Article and Find Full Text PDF

Background: Knowledge of the chemical composition of amyloid plaques and tau tangles at the earlier stages of Alzheimer's disease (AD) pathology is sparse. This is due to limited access to human brain during life and at the earlier stages of AD pathophysiology and technical limitations in quantifying amyloid and tau species at a subcellular level. Understanding the chemical composition of plaques and tangles, how rapidly they grow and what factors drive growth is important for developing and refining therapeutics.

View Article and Find Full Text PDF

Basic Science and Pathogenesis.

Alzheimers Dement

December 2024

Homi Bhabha National Institute, Mumbai, Maharashtra, India.

Background: Receptor Tyrosine kinase-mediated signaling is indispensable for the cell's normal functioning, the perturbation of which leads to disease conditions. The altered expression and activity of several Receptor Tyrosine kinases (RTKs) are known to regulate the pathophysiology of Alzheimer's disease (AD). However, the mechanistic details remain illusive.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!