106 research outputs found
Analytical Hierarchy Process Evaluation of the Proposed Slim Modular Flexible Electric Bus Rapid Transit System
As metropolitan Atlanta area is the one of the fastest growing regions in the nation, its demand for transportation infrastructure has grown. The region between Cobb County and Fulton County experiences the heaviest congestion in Metro-Atlanta. CobbLinc Route 10 is the only form of public transportation serving this area. To relieve the congestion and provide more effective public transportation system, Connect Cobb Corridor project has been proposed with the possible implementation of Bus Rapid Transit (BRT) system. Although BRT has gained popularity for its operational flexibility and efficiency, efforts have been put into developing a new concept vehicle that is better functioning and more cost-effective. Slim Modular Flexible Electric Bus Rapid Transit (SMFe-BRT) has characteristics that are expected to reduce the initial construction and operation and maintenance costs. Also, it is expected to have higher operational flexibility. The thesis evaluates these two public transit vehicle alternatives using analytical hierarchy process (AHP) method. Three categories of evaluation criteria—transit, emissions, and finances—are generated for AHP model. The traffic software Vissim is used to obtain evaluation results from Cobb Corridor for A.M., P.M., and off-peak conditions. Based on Vissim results and AHP, it is suggested that the implementation of SMFe-BRT is more beneficial than the traditional BRT
Dense Text-to-Image Generation with Attention Modulation
Existing text-to-image diffusion models struggle to synthesize realistic
images given dense captions, where each text prompt provides a detailed
description for a specific image region. To address this, we propose
DenseDiffusion, a training-free method that adapts a pre-trained text-to-image
model to handle such dense captions while offering control over the scene
layout. We first analyze the relationship between generated images' layouts and
the pre-trained model's intermediate attention maps. Next, we develop an
attention modulation method that guides objects to appear in specific regions
according to layout guidance. Without requiring additional fine-tuning or
datasets, we improve image generation performance given dense captions
regarding both automatic and human evaluation scores. In addition, we achieve
similar-quality visual results with models specifically trained with layout
conditions.Comment: Accepted by ICCV2023. Code and data are available at
https://github.com/naver-ai/DenseDiffusio
Spinal Stereotactic Body Radiotherapy (SBRT) Planning Techniques
Stereotactic body radiotherapy (SBRT) delivers a highly conformal and hypofractionated radiation dose to a small target with minimal radiation applied to the surrounding areas. The spine is an ideal site for SBRT owing to its relative immobility, the potential clinical benefits of high-dose delivery to this area, and the presence of adjacent critical structures such as the spinal cord, esophagus, and bowel. However, with the potential for radiation myelopathy if the dose is delivered inaccurately or if the spinal cord dose limit is set too high, proper treatment planning techniques for SBRT are important. Intensity modulation techniques are useful for spinal SBRT because of a rapid dose falloff and spinal cord avoidance. In this chapter, various planning techniques will be discussed and reviewed
Context-Preserving Two-Stage Video Domain Translation for Portrait Stylization
Portrait stylization, which translates a real human face image into an
artistically stylized image, has attracted considerable interest and many prior
works have shown impressive quality in recent years. However, despite their
remarkable performances in the image-level translation tasks, prior methods
show unsatisfactory results when they are applied to the video domain. To
address the issue, we propose a novel two-stage video translation framework
with an objective function which enforces a model to generate a temporally
coherent stylized video while preserving context in the source video.
Furthermore, our model runs in real-time with the latency of 0.011 seconds per
frame and requires only 5.6M parameters, and thus is widely applicable to
practical real-world applications.Comment: 5 pages, 3 figures, CVPR 2023 Workshop on AI for Content Creatio
BallGAN: 3D-aware Image Synthesis with a Spherical Background
3D-aware GANs aim to synthesize realistic 3D scenes such that they can be
rendered in arbitrary perspectives to produce images. Although previous methods
produce realistic images, they suffer from unstable training or degenerate
solutions where the 3D geometry is unnatural. We hypothesize that the 3D
geometry is underdetermined due to the insufficient constraint, i.e., being
classified as real image to the discriminator is not enough. To solve this
problem, we propose to approximate the background as a spherical surface and
represent a scene as a union of the foreground placed in the sphere and the
thin spherical background. It reduces the degree of freedom in the background
field. Accordingly, we modify the volume rendering equation and incorporate
dedicated constraints to design a novel 3D-aware GAN framework named BallGAN.
BallGAN has multiple advantages as follows. 1) It produces more reasonable 3D
geometry; the images of a scene across different viewpoints have better
photometric consistency and fidelity than the state-of-the-art methods. 2) The
training becomes much more stable. 3) The foreground can be separately rendered
on top of different arbitrary backgrounds.Comment: Project Page: https://minjung-s.github.io/ballga
Functionalization of Biotinylated Polyethylene Glycol on Live Magnetotactic Bacteria Carriers for Improved Stealth Properties
The early removal of drug delivery agents before reaching the affected target remains an area of interest to researchers. Several magnetotactic bacteria (MTB) have been used as self-propelled drug delivery agents, and they can also be controlled by an external magnetic field. By attaching the PEG–biotin polymer, the bacteria are turned into a stealth material that can escape from the phagocy-tosis process and reach the area of interest with the drug load. In the study, we developed a potential drug carrier by attaching the PEG–biotin to the MTB-through-NHS crosslinker to form a MTB/PEG– biotin complex. The attachment stability, efficacy, and bacterial viability upon attachment of the PEG– biotin polymer were investigated. Biological applications were carried out using a cytotoxicity assay of THP-1 cells, and the results indicate that the MTB/PEG–biotin complex is less harmful to cell viability compared to MTB alone. Along with cytotoxicity, an assay for cell association was also evaluated to assess the complex as a potential stealth material. The development of these complexes focuses on an easy, time-saving, and stable technique of polymer attachment with the bacteria, without damaging the cell’s surface, so as to make it a strong and reliable delivery agent. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.1
Low-density lipoprotein cholesterol goal attainment rates in high-risk patients with cardiovascular diseases and diabetes mellitus in Korea: a retrospective cohort study
Background
Real-world evidence of low-density lipoprotein cholesterol (LDL-C) goal attainment rates for Asian patients is deficient. The objective of this study was to assess the status of dyslipidemia management, especially in high-risk patients with cardiovascular disease (CVD) including stroke and acute coronary syndrome (ACS).
Methods
This was a retrospective cohort study of 514,866 subjects from the National Health Insurance Service-National Health Screening Cohort database in Korea. Participants were followed up from 2002 to 2015. Subjects with a high-risk of CVD prior to LDL-C measurement and subjects who were newly-diagnosed for high-risk of CVD following LDL-C measurement were defined as known high-risk patients (n = 224,837) and newly defined high-risk patients (n = 127,559), respectively. Data were analyzed by disease status: stroke, ACS, coronary heart disease (CHD), peripheral artery disease (PAD), diabetes mellitus (DM) and atherosclerotic artery disease (AAD).
Results
Overall, less than 50% of patients in each disease category achieved LDL-C goals (LDL-C < 70 mg/dL in patients with stroke, ACS, CHD and PAD; and LDL-C < 100 mg/dL in patients with DM and AAD). Statin use was observed in relatively low proportions of subjects (21.5% [known high-risk], 34.4% [newly defined high-risk]). LDL-C goal attainment from 2009 to 2015 steadily increased but the goal-achiever proportion of newly defined high-risk patients with ACS remained reasonably constant (38.7% in 2009; 38.1% in 2015).
Conclusions
LDL-C goal attainment rates in high-risk patients with CVD and DM in Korea demonstrate unmet medical needs. Proactive management is necessary to bridge the gap between the recommendations of clinical guidelines and actual clinical practice.This study was supported by a research grant from Amgen, Inc
Potential Cause of Decrease in Bloom Events of the Harmful DinoflagellateCochlodinium polykrikoidesin Southern Korean Coastal Waters in 2016
Blooms of the ichthyotoxic dinoflagellateCochlodinium polykrikoidesare responsible for massive fish mortality events in Korean coastal waters (KCW). They have been consistently present in southern KCW over the last two decades, but they were not observed in 2016, unlike in the previous years. Despite extensive studies, the cause of this absence of this dinoflagellate bloom remains largely unknown. Thus, we compared physico-chemical and biological data from along the Tongyeong coast between 2016 and the previous four years (2012-2015). The averages of water temperature and salinity in August, 2016 were significantly (p< 0.001) different from those in the previous years. The amount of Changjiang River discharge, which can affect the environmental conditions in the southern Korean coastal area via ocean currents, was larger than in the previous years, resulting in a reduction in the salinity level in August when blooms ofC. polykrikoidesusually occurred. Moreover, compared to previous years, in 2016, there was a weak expansion ofC. polykrikoidesblooms in the Goheung-Oenarodo area whereC. polykrikoidesblooms were annually initiated in KCW. Lastly, the strong winds from the typhoon Lionrock may also have contributed to the early termination of this dinoflagellate bloom. Together with these findings, the combination of these environmental conditions in 2016, unlike in previous years, may have inhibited the formation ofC. polykrikoidesblooms along the Tongyeong coast
Structural Basis for Enhanced HIV-1 Neutralization by a Dimeric Immunoglobulin G Form of the Glycan-Recognizing Antibody 2G12
The human immunoglobulin G (IgG) 2G12 recognizes high-mannose carbohydrates on the HIV type 1 (HIV-1) envelope glycoprotein gp120. Its two antigen-binding fragments (Fabs) are intramolecularly domain exchanged, resulting in a rigid (Fab)_2 unit including a third antigen-binding interface not found in antibodies with flexible Fab arms. We determined crystal structures of dimeric 2G12 IgG created by intermolecular domain exchange, which exhibits increased breadth and >50-fold increased neutralization potency compared with monomeric 2G12. The four Fab and two fragment crystalline (Fc) regions of dimeric 2G12 were localized at low resolution in two independent structures, revealing IgG dimers with two (Fab)_2 arms analogous to the Fabs of conventional monomeric IgGs. Structures revealed three conformationally distinct dimers, demonstrating flexibility of the (Fab)_2-Fc connections that was confirmed by electron microscopy, small-angle X-ray scattering, and binding studies. We conclude that intermolecular domain exchange, flexibility, and bivalent binding to allow avidity effects are responsible for the increased potency and breadth of dimeric 2G12
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