781 research outputs found
Incident duration time prediction using a supervised topic modeling method
Precisely predicting the duration time of an incident is one of the most prominent components to implement proactive management strategies for traffic congestions caused by an incident. This thesis presents a novel method to predict incident duration time in a timely manner by using an emerging supervised topic modeling method. Based on Natural Language Processing (NLP) techniques, this thesis performs semantic text analyses with text-based incident dataset to train the model. The model is trained with actual 1,466 incident records collected by Korea Expressway Corporation from 2016-2019 by applying a Labeled Latent Dirichlet Allocation(L-LDA) approach. For the training, this thesis divides the incident duration times into two groups: shorter than 2-hour and longer than 2-hour, based on the MUTCD incident management guideline. The model is tested with randomly selected incident records that have not been used for the training. The results demonstrate that the overall prediction accuracies are approximately 74% and 82% for the incidents shorter and longer than 2-hour, respectively
A Study of Siete canciones populares Españolas by Manuel de Falla
Among Manuel de Falla's famous works, I have selected Siete canciones populares Españolas(Seven Spanish Folksongs) as the theme of my lecture recital in view of the relative dearth of sources that deal with cello performance practice in this great work. In particular, I have examined the way French cellist Maurice Maréchal (1892-1964) arranged a suite for cello and piano from Falla's setting of popular Spanish songs. Maréchal was a French cellist who worked with his contemporaries; for example, he premiered Ravel's Sonata for Violin and Cello with the violinist Helene Jourdan-Morhange in 1922. His arrangement exploits the expressive language of the cello and is worthy of study in view of an appropriate performance practice. The purpose of this project is to investigate various ways to present Spanish musical expressions found in Seven Spanish Folksongs in terms of cello technique, to recreate the unique accent of Spanish song. Through an analysis of the piece, I will discuss nationalistic elements on form, melody, harmony, rhythm, and performance practice. From a cellist's perspective, I will provide clear guidelines about what aspects should be considered when performing this piece. Additionally I will consider how the pianist should approach the piano part in respect to the cello sounds and performance practice
Simulation of anyonic statistics and its topological path independence using a 7-qubit quantum simulator
Anyons, quasiparticles living in two-dimensional spaces with exotic exchange
statistics, can serve as the fundamental units for fault-tolerant quantum
computation. However, experimentally demonstrating anyonic statistics is a
challenge due to the technical limitations of current experimental platforms.
Here, we take a state perpetration approach to mimic anyons in the Kitaev
lattice model using a 7-qubit nuclear magnetic resonance quantum simulator.
Anyons are created by dynamically preparing the ground and excited states of
the 7-qubit Kitaev lattice model, and are subsequently braided along two
distinct, but topologically equivalent, paths. We observe that the phase
acquired by the anyons is independent of the path, and coincides with the ideal
theoretical predictions when decoherence and implementation errors are taken
into account. As the first demonstration of the topological path independence
of anyons, our experiment helps to study and exploit the anyonic properties
towards the goal of building a topological quantum computer.Comment: 12 pages and 9 figures. All comments are welcome
Adverse Childhood Experiences (ACEs), Service Use, and Service Helpfulness Among People Experiencing Homelessness
This study examines categories of adverse childhood experiences (ACEs) and service use backgrounds among a convenience sample of people experiencing homelessness (N = 224), using logistic regression analysis (n = 174) and descriptive and comparative analyses. Eighty-seven percent reported at least 1 of 10 ACEs prior to age 18. Over half (53.2%) reported 4 or more ACEs. Approximately half reported parental loss, emotional neglect, living with a substance abuser, and emotional abuse. ACEs were significantly correlated with one another. Among those who used prior services, ACEs predicted interpersonal prevention, clinical, and criminal justice services for emotional or substance abuse problems. Most indicated services were helpful. This study provides data for policy and program leaders to ensure at-risk families and communities have access to responsive services
Estimation of Volatility Functions in Jump Diffusions Using Truncated Bipower Increments
In the paper, we introduce and analyze a new methodology to estimate the volatility
functions of jump diffusion models. Our methodology relies on the standard kernel
estimation technique using truncated bipower increments. The relevant asymptotics
are fully developed, which allow for the time span to increase as well as the sampling
interval to decrease and accommodate both stationary and nonstationary recurrent
processes. We evaluate the performance of our estimators by simulation and provide
some illustrative empirical analyses
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Regulation and function of two membrane-associated protein kinases
Protein kinases, many of which are regulated by autophosphorylation, modify their substrates by phosphorylation. Due to their roles in cellular signaling cascades controlling processes such as cellular proliferation, differentiation, metabolism, and apoptosis, protein kinases have caught the attention of scientists. In this study, we characterized the regulation and functions of two human membrane-bound protein kinases, TRPM7 and PERK. TRPM7 (transient receptor potential melastatin 7) is a non-selective cation channel fused to an atypical kinase domain at the C-terminus that is implicated in cellular magnesium homeostasis. While the channel properties of TRPM7 have been studied extensively, little is known about the mechanisms regulating its kinase activity. Furthermore, to date, no specific small molecule inhibitor of TRPM7 kinase has been identified. Therefore, we characterized the biochemical and functional properties of TRPM7 autoactivity and discovered the first group of small molecule compounds targeting the kinase activity. Through a broad range of biochemical assays, we demonstrated that early autophosphorylation on three serine residues is required for TRPM7 kinase activity. These phosphorylations promote a tetramer to dimer transition of the catalytic domain, as well as its cellular association with myosin. Aided by the discovery of effective kinase inhibitors a role for the kinase domain in actomyosin contractility and migration was examined. PERK (PKR-like endoplasmic reticulum kinase) is a serine/threonine kinase, resident in the ER membrane and activated by the unfolded protein response (UPR), which detects the accumulation of unfolded proteins in the ER. The UPR and PERK are up-regulated in a variety of tumor types and may be critical for cancer cell adaptation. Therefore, a goal of this study was to identify PERK inhibitors that will provide new potential therapeutic strategies for treating cancer. We discovered a number of lead compounds and validated their ability to inhibit PERK kinase activity in vitro. The most potent PERK inhibitor was further tested to evaluate the modulation of the PERK signaling pathway in pancreatic cancer cells.Cellular and Molecular Biolog
Identifying bioactive phytochemicals in spent coffee grounds for cosmetic application through global metabolite analysis
Field of study: Natural resources.Dr. Chung-Ho Lin, Thesis Supervisor."December 2017."Annually, more than 6 million tons of spent coffee grounds (SCG) are generated worldwide. The present study explores the possible use of spent coffee grounds as the raw materials for cosmetics industry. The main objective of this project are to investigate the chemical profiles and identify the bioactive compounds for cosmetics application through global metabolite analysis. The compounds extracted from SCG of Ethiopia coffee (Yirgacheffe), Costa Rican coffee (Tarrazu) and Hawaiian coffee (Kona) were analyzed by ultra-high pressure liquid chromatography coupled with mass spectrometry (UPLC-MS). The ion chromatograms were submitted to XCMS platform operated by Center for Metabolomics at the Scripps Research Institute. The peak detection, peak grouping, spectra extraction, and retention alignment were processed by XCMS. The spectra were annotated and the compounds were identified and categorized by integration with METLIN, the world's largest metabolite database. Multivariate and univariate statistical analysis including PCA and cloud-plot were performed by XCMS to compare the chemical profiles between the three coffee cultivars. These analyses indicated that each cultivar showed a specific cluster. Over 200 compounds related to anti-oxidant, anti-inflammatory, anti-tyrosinase and anti-tumor for skin care application were identified by XCMS. Therefore, the presence of bioactive compounds in SCG makes it a potential source of raw material for cosmetic application (e.g., anti-oxidant, anti-inflammatory, skin-whiting, and anti-aging).Includes bibliographical references (pages 103-122)
Emulation of Anyonic Statistics using High-Fidelity NMR Quantum Information Processing (QIP) Techniques
NMR control techniques have made many important contributions in developing set of tools for optimal quantum control, ranging from spin echo to dynamical decoupling. Using such optimal quantum control techniques, the emulation of what are known as anyonic statistics was demonstrated previously. This demonstration showed the ability of NMR QIP for experimental exploration of topological quantum computing where anyonic statistics play a significant role as a means to implement the quantum gates by braiding anyons. In this thesis, going one step further than the previous demonstration, we experimentally emulated the anyonic statistics and demonstrated the path independence of anyonic braiding operations manifested in a 7-qubit Kitaev's lattice model. In our experiments, the anyons are braided along two different loops in which the system's wave function gains a π phase in theory. We experimentally measured the anyonic phases of (153.9 ± 3.8)° and (151.4 ± 3.8)° for the two different braiding paths, demonstrating that experimental anyonic phases are path independent. However, the values differ from the theoretical value due to decoherence and gate imperfections
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