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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
341

Light and Space Through Photography

Paz Morales, Antonio 30 June 2014 (has links)
Photography now days challenge our perception of space, light, and architecture. Photography has challenge the way we perceive, interact and communicate in the world. In today society photography has find ways to communicate faster through images. Technology has played a big part on how we exchange pictures making it very accessible to all ages and cultures. As photography has become more accessible and it has become more technological advance, new challenges and problems have emerge. I consider that society has lost the ability to be aware of two basic essential elements which are light and space. These two elements are very important in photography but also in the human physical and emotional existence. I wanted to celebrate the learning process of photography and to be more conscious of the superficial world we live in today. I consider that by educating new generation the process of light and space can influence how people can become more in touch with its spiritual being. By providing a educational space in Georgetown where people are able to interact with visual media and learn the process of photography can have a positive impact individually and collectively. Considering that many people visit Georgetown every year became a important portal to spread the knowledge globally. / Master of Architecture
342

Revealing The Unknown: Revelation Chapel

Gore, Brian Christoper 23 June 2020 (has links)
This thesis studies how light, as a spiritual and symbolic element, cannot only uplift the human condition but also evoke the spiritual. The result can cause one to know what is unknowable without the presence of light and make one aware of what was unknown to them, as well as, revealing what is greater than themselves. The objective is to explore and design spaces that progressively lift the eyes of the observer with natural lighting techniques. Natural light is used to create a better sense of physical and spiritual awareness. / Master of Architecture / This thesis studies how light, as a spiritual and symbolic element, cannot only uplift the human condition but also evoke the spiritual. The result reveals what is greater than themselves. The objective is to explore and design spaces that progressively lift the eyes of the observer with natural lighting techniques. Natural light is used to create a heightened sense of physical and spiritual awareness. Using light, one is led on a staged journey through a series of reflection spaces. This thesis explores how light can be the thing that provides revelation and a deeper understanding of not only one's self, but the world around them, as well as, things greater than themselves.
343

The Influence of Overstory Structure on Understory Light Availability in a Longleaf Pine (Pinus palustris Mill.) Forest

Battaglia, Michael Anthony 23 October 2000 (has links)
Understory light environments are inherently heterogeneous and therefore difficult to characterize. Numerous methods to measure understory light have been assessed in closed-canopied forests; however, the reliability of these methods has not been addressed for open-canopied forests. Therefore, the first objective of this study, presented in Chapter 3, was to test the accuracy and precision of various light measurement techniques at different time scales and sky conditions. The methods assessed performed differently depending on the sky condition and time of year when the sample was taken. To estimate annual photosynthetic photon flux density transmittance (annual %PPFD), the use of a 10-minute average of PPFD measured on an overcast day (%PPFDovercast) was effective, but accuracy decreased with decreasing solar altitude (ie season change). Hemispherical photographs used to estimate weighted canopy openness and gap fraction were effective methods, but gap light index (GLI) also derived from hemispherical photographs performed better. Accuracy of daily %PPFD estimates using %PPFDovercast, weighted canopy openness, and gap fraction were strongly affected by solar altitude and sky condition. Gap light index was very effective in estimating daily %PPFD for all sky conditions and time periods. The second objective of this study, presented in Chapter 4, was to characterize the relationship between canopy structure and spatial distribution of light by using three replicates of one uncut treatment and three harvest treatments: single tree, small gap (0.1 ha), and large gap (0.2 ha). Each harvest retained similar residual basal area but with different spatial patterns of the residuals, ranging from uniformly dispersed (single tree) to different degrees of aggregation (small and large gap). Average stand level light availability increased 12-22% when the same residual basal area of trees was distributed in clusters versus a uniform distribution. The variation of light availability increased as stands became more aggregated and larger amounts of the variation was explained by the spatial pattern of the canopy structure. Spatial autocorrelation range was twice as large in the small gap harvest then the other harvest treatments. It is suggested that seedling growth response to these differences in spatial patterns of light may differ between the different harvests. / Master of Science
344

The Relationship of Light Wave Length to Tissue Differentiation in Sunflower Seedlings

Wilson, Bobby Eugene 08 1900 (has links)
The purpose of this study is to determine the relationship of light wave length to tissue differentiation in sunflower seedlings.
345

Studies on the reproduction of the ground squirrel with reference to pituitary implantation, vaginal smears, and light

Gann, Eldred Lamonte January 2011 (has links)
Typescript, etc. / Digitized by Kansas State University Libraries
346

Sources, intensities, and spectral distribution of electromagnetic energy for plant irradiators

Lupfer, David Arthur. January 1948 (has links)
Call number: LD2668 .T4 1948 L86 / Master of Science
347

Optimal placement of light fixtures for energy saving

Tian, Huamei 05 April 2016 (has links)
Energy consumption of large commercial buildings has become higher than before, and a major part of the energy is on their lighting systems. This thesis aims at reducing the energy consumption of a building's lighting system. Our solution is to minimize the total number of necessary light fixtures in a commercial building, and thus we formulate the Constrained Light Deployment Problem (CLDP). The CLDP problem is tightly related to the Art Gallery Problem (AGP), a classical problem in computational geometry that finds the minimum number of guards to monitor a polygon area. Unlike the traditional AGP, however, our problem poses a new challenge that the illuminance of any spot in the building must be higher than a required threshold. To address the new challenge, we first propose an algorithm based on polygon partition and iteratively remove redundant light fixtures to obtain a tighter upper bound on the necessary number of light fixtures. We further improve the algorithm with clustering and binary search to reduce the number of light fixtures. Our algorithm can return the locations of resulted light fixtures, which are not necessarily the vertices of the orthogonal polygon. Simulation results demonstrate that our algorithm is fast and effective. / Graduate
348

High performance drive circuits for integrated microLED/CMOS arrays for visible light communication (VLC)

Mahmood Zuhdi, Ahmad Wafi January 2015 (has links)
Wireless communication is a form of communication that has been around for over hundreds of years and is the fastest growing segment of the communication industry. Today, wireless communication has become an essential part of almost everyone’s daily life, and the number of users has increased exponentially over the last decade with the introduction of the internet, mobile devices and smart phones. Radio Frequency (RF) transmission is arguably the most popular method of communication and is available worldwide. With the rapid progress in technology and the increase of number of users, the limited RF spectrum is becoming more congested which led to numerous research efforts to find an alternative that can help to alleviate the pending problem. One of the proposed solutions is Visible Light Communication (VLC), which uses visible Light Emitting Diode (LED) for data transmission. In this thesis, three integrated microLED/Complementary Metal Oxide Semiconductor (CMOS) Integrated Circuits (ICs) are presented with the main aim of increasing the data rate of transmission. The first microLED/CMOS IC presented here is the Generation V microLED/CMOS driver which represents the continuation of the earlier work in the HYPIX project, which aimed to develop a microLED/CMOS driver to optically pump an organic polymer laser. A 40x10 pixelarray of Generation V microLED/CMOS driver was thus designed, primarily for optical pumping polymer lasing purposes, but has also demonstrated the ability to perform communication transmission using an On-Off Keying (OOK) modulation scheme. The driver consumes up to 330mA current and produces approximately 12mW of optical power from a single pixel, which is about 3 times higher than its predecessor. The second microLED/CMOS IC is the microLED/CMOS Current Feedback (CCFBK) driver which was designed to facilitate Orthogonal Frequency Division Multiplexing (OFDM) modulation. OFDM is one of the modulation schemes, adopted from the RF domain, that was proposed to be implemented in VLC in order to increase the data transmission rate. To the best of the author’s knowledge, the microLED/CCFBK driver is the first CMOS driver for microLED that was designed to perform analogue modulation for VLC purposes. The driver is characterised and shows the ability to produce up to 3.5mW of optical power with a data transmission rate of up to 486Mbit/s. The microLED/CMOS Optical Feedback (COFBK) driver is the third microLED/CMOS IC presented in this thesis. The driver looks to improve on the performance of the microLED/CCFBK driver. OFDM transmission requires high linearity to ensure low Bit Error Rate (BER) transmission. However, the optical power output of an LED is not, in general, linear with the input voltage signal. The microLED/COFBK driver looks to increase the linearity of the optical power output by integrating a microLED and a photodiode in a single pixel to create a feedback loop. Once again, to the best of the author’s knowledge, the microLED/COFBK driver is the first CMOS driver for microLED which integrates both optical source and sensor in a single pixel to help linearise the optical power output for communication purposes; in this case, VLC. For a similar range of optical power, the microLED/COFBK driver shows a reduction about 5.3% in the degree of non-linearity compared to the microLED/CCFBK driver and produces lower Total Harmonic Distortion (THD). The microLED/COFBK driver showed the potential to increase the data rate by a factor of four over that of microLED/CCFBK driver. The analogue modulated microLED/CMOS ICs described here are the first-generation drivers that have demonstrated the possibilities to increase the data rate using OFDM. A number of possible design improvements have been identified which will enhance future performance and integration with the standard VLC system.
349

THE POLARIZED LIGHT SCATTERING MATRIX ELEMENTS FOR SELECT PERFECT AND PERTURBED OPTICAL SURFACES (MUELLER, MIRRORS, O).

Iafelice, Vincent John. January 1985 (has links)
No description available.
350

Implementation of environmental zoning scheme to control light pollution in Hong Kong

葉嘉勳, Yip, Ka-fan, Kelven. January 2008 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

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