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Metasurfaces in 3D applications: multiscale stereolithography and inverse design of diffractive optical elements for structured light
No full text2019-07-15The main focus of this dissertation is on nanophotonics and its applications in 3D printing, 3D sensing, and nonlinear optics. ❧ The first part covers the multiscale stereolithography. Additive manufacturing has many advantages in creating highly complex customized structures. However, existing additive manufacturing technologies have a trade-off between throughput and resolution. In this work, Multiscale Stereolithography process is invented to addresses this issue, and it is able to print macroscale objects with microscale surface structures with high throughput at low cost. This process is realized by dynamic switching of laser spot size and adaptively sliced layer thickness. Digital models are separated into high resolution part and low resolution part. These two parts are printed using variable voxel size technique in which a small voxel size is used for high resolution and a big voxel size is used for high throughput. Many structures in nature possess superb functions due to the multiscale characteristics in them. For proof-of-concept testing, artificial shark skins with micro riblet features were designed and 3D printed. In pipe flow experiments, the 3D printed shark skin demonstrated almost 10% average fluid drag reduction. Artificial lotus leaf surfaces were also 3D printed to demonstrate superhydrophobic property. In terms of throughput, the multiscale SLA process demonstrated 4.4× better than traditional SLA process in the tests. The advantage became even more significant when bigger size objects were printed. It provides the capability to experimentally study various multiscale structures in future research. Being able to provide high resolution and high throughput at the same time with low cost, the multiscale stereolithography process has the potential to serve as a powerful tool that can bring bio-inspired structures into real-life applications. ❧ The second part covers the inverse design method for diffractive optical elements(DOEs). 3D sensing has been an increasingly popular area due to the development of face recognition on mobile devices as well as autonomous driving cars. DOE is a low cost, compact solution for generating structured light for 3D sensing applications. However, the parameter space of DOEs is if often significantly larger than traditional geometric optical elements such as lenses and periodic diffractive optical elements such as gratings. The reason is that the height of each pixel on a DOE is an independent variable and there is no inherent symmetry to reduce the number of variables. Therefore, the parameter sweeping approach is not practical for designing DOEs. Using iterative numerical optimization is an effective way to reduce the number of iterations required to find the optimal design. In this work, an inverse DOE design method with particle swarm optimization is proposed which takes DOE radiation pattern as input and manufacturability of DOE as the figure of merit. This inverse method has the benefit of reducing the number of variables in optimization and minimizing the loss of performance due in fabrication. As a demonstration, two DOEs that project periodic dot array pattern and encoded binary pattern were fabricated. Optical characterization showed the radiation patterns matched the designs which validates the inverse design method. ❧ The third part summarizes my work in metamaterials with nonlinearity at multiple wavelength ranges. The evolution of optical communication systems has followed the footsteps of the developments of radio communication. The future optical communication systems will be the same as the RF communication systems today: It will be built on a Si photonics chip with integrated electronics. The information will be coded with advanced modulation schemes and the signal will be detected by an optical superheterodyne receiver. To realize optical superheterodyne, the nonlinear mixer is the key challenge. There is no material in the current Si platform with high nonlinearity. I propose to demonstrate metamaterials with high non-linearity at both optical and microwave wavelengths simultaneously for the first time
Faculty internationalization at the Hong Kong University of Science and Technology (HKUST): a promising practice study
No full text2019-06-21The purpose of this case study was to explore a promising practice, the Hong Kong University of Science and Technology (HKUST), to better understand gaps in faculty internationalization in higher education. More specifically, the dissertation looked at how HEIs can be more successful in attracting, hiring, and retaining international faculty. A qualitative approach of interviews and document analysis was utilized, and the conceptual framework was the Clark and Estes (2008) gap analysis. A total of eleven participants were interviewed, including administrators and faculty, and four major documents were reviewed. Findings validated 17 of 22 assumed assets and discovered four contextual assets. Key assets and potentially transferable practices based on the promising practice include a continuous focus on quality and diversity, the implementation of strategies to recruit faculty globally, the review and implementation of competitive compensation and benefits, and the development of policies to support and integrate international faculty and their families. An implementation, including action steps and timeline, and an evaluation plan for each of the recommendations, provide a basic roadmap for the development of a faculty internationalization strategy
The brain and behavior of motor learning: the what, how and where
No full text2019-06-28This dissertation has the following three aims: Aim 1) Examine how individual participants learn a rule-based motor task where success is contingent upon rule discovery. Aim 2) Identify the cortical substrates from resting-state EEG that predict the processes of discovery learning. Aim 3) Test the feasibility of an intervention that uses non-invasive brain stimulation to potentiate a putative neural circuit known to be engaged in the discovery learning process. Together, results from this dissertation provide new evidence of an understudied area, the process of motor learning (what is learned?) and not just the outcome; which key cortical networks are engaged in the learning process (where does the learning occur?), and if a putative neural correlate (i.e., intracortical circuit) can be effectively modified using a high quality iPAS paradigm (how can we effect the learning process?)
Caledonia Bay people [K-4A], 1939
No full text"Caledonia Bay people". Several white men and a local native in a small boat towing a rowboat in the bay, grass huts, laundry, children, small sail boat, children in small boats, the Velero III in the bay, a few white men surrounded by children in a village, the flag of Panama, close ups of native faces, Caledonia Bay, Panama, 1939. Note: requires preservation (original, trims, good)
Carnival and parade, 1920s
No full text"Fleishman Carnival, expeditions". Crowds of people mingle around and watch booths for arcade games, rides (swings, ferris wheel "Caterpillar" roller coaster, carousel, and others), a 9-pole tent, a showing of horses and cattle. Also includes a military parade on a city street with a drum corps, 1920s automobiles, circus wagons ("Foley & Burk Shows"), ca. 1920s. Reel patent date is stamped on reel "Nov. 21, 1911"
Velero IV at sea maintenance, 1949-1950
No full text"Velero IV '49-'50 cruise". Maintenance on various items on the Velero IV (ship): stitching a net, crewman on aft deck near benthograph fixing cable, crewman maintaining dredge net, 1949-1950. "Working around ship, lines, nets, KCO" -- written on adhesive tape on film
C'Opera (without diner scene), 2006
No full textCreated in collaboration with the Los Angeles Police Department, this opera took the audience on a journey throughout the historic Police Academy’s gymnasium, rock garden, coffee shop and firing range. With live music by Amy Knoles and Dorothy Stone and libretto by Merridawn Duckler, 2006
Mr. Westinghouse, 1994
No full textA duet for dancer and refrigerator, Mr. Westinghouse satires domesticity through the portrayal of this anthropomorphic relationship. Accompanied by music by Harry Gilbert on cello, the conversation between woman and fridge portrays the hunger for love. Performances of this piece were done at the Los Angeles Women’s Theatre Festival, Los Angeles, in 1996, and the Dance Kaleidoscope Festival at California State University, Los Angeles, 1994
Murray, Never too wise for god to teach you, 1996-06-16
No full textNever too wise for god to teach you, a sermon given by Cecil "Chip" Murray at First African Methodist Episcopal Church of Los Angeles (FAME) (First AME Church), 2270 South Harvard Boulevard, Los Angeles, California, USA, on 1996 June 16
Murray, There's always a third day, 1992-04-16
No full textThere's always a third day, a sermon given by Cecil "Chip" Murray at First African Methodist Episcopal Church of Los Angeles (FAME) (First AME Church), 2270 South Harvard Boulevard, Los Angeles, California, USA, on 1992 April 19