arXiv subjects

Jason Lawrence

Publications and source records attributed to Jason Lawrence.

5 recordsLinked to original sources

arXiv2023

Towards Understanding the Benefits and Challenges of Demand Responsive Public Transit- A Case Study in the City of Charlotte, NC

Access to reliable public transportation is essential for addressing socio-economic disparities, particularly in low-income communities that rely heavily on transit for accessing jobs, healthcare, and essential services. This study investigates the challenges faced by transit-dependent populations in Charlotte, NC, focusing on the spatial and service-related inequities within the current public bus system. Our research initially evaluates critical issues such as extended wait times, unreliable schedules, and limited accessibility, which significantly impact the daily lives of low-income residents. In response to these challenges, we gathered data to assess the potential for a connected, demand-responsive bus system designed to minimize transit gaps and enhance service efficiency in the future. This evaluation included an analysis of the existing Charlotte Area Transit System (CATS) mobile applications and the exploration of user acceptance for a proposed smart, on-demand transit technology. Through surveys conducted across key bus lines-including the Sprinter line and Bus Lines 7, 9, and 97-99-we identified significant shortcomings in the current system. However, our findings also indicate a strong willingness among participants to adopt new transit solutions, provided that they effectively address current issues and alleviate concerns related to smartphone accessibility, privacy, and trust. This research contributes valuable insights into the modernization of public transit systems in Charlotte, highlighting the importance of user-centric approaches in developing innovative, equitable, and efficient transportation solutions.

cs.CY↗

arXiv2020

Time-Travel Rephotography

Many historical people were only ever captured by old, faded, black and white photos, that are distorted due to the limitations of early cameras and the passage of time. This paper simulates traveling back in time with a modern camera to rephotograph famous subjects. Unlike conventional image restoration filters which apply independent operations like denoising, colorization, and superresolution, we leverage the StyleGAN2 framework to project old photos into the space of modern high-resolution photos, achieving all of these effects in a unified framework. A unique challenge with this approach is retaining the identity and pose of the subject in the original photo, while discarding the many artifacts frequently seen in low-quality antique photos. Our comparisons to current state-of-the-art restoration filters show significant improvements and compelling results for a variety of important historical people.

cs.CV↗

arXiv2020

A Dark Flash Normal Camera

Casual photography is often performed in uncontrolled lighting that can result in low quality images and degrade the performance of downstream processing. We consider the problem of estimating surface normal and reflectance maps of scenes depicting people despite these conditions by supplementing the available visible illumination with a single near infrared (NIR) light source and camera, a so-called "dark flash image". Our method takes as input a single color image captured under arbitrary visible lighting and a single dark flash image captured under controlled front-lit NIR lighting at the same viewpoint, and computes a normal map, a diffuse albedo map, and a specular intensity map of the scene. Since ground truth normal and reflectance maps of faces are difficult to capture, we propose a novel training technique that combines information from two readily available and complementary sources: a stereo depth signal and photometric shading cues. We evaluate our method over a range of subjects and lighting conditions and describe two applications: optimizing stereo geometry and filling the shadows in an image.

cs.CV↗

arXiv2020

On the Polarization of Ligands by Proteins

Although ligand-binding sites in many proteins contain a high number density of charged side chains that can polarize small organic molecules and influence binding, the magnitude of this effect has not been studied in many systems. Here, we use a quantum mechanics/molecular mechanics (QM/MM) approach in which the ligand is the QM region to compute the ligand polarization energy of 286 protein-ligand complexes from the PDBBind Core Set (release 2016). We observe that the ligand polarization energy is linearly correlated with the magnitude of the electric field acting on the ligand, the magnitude of the induced dipole moment, and the classical polarization energy. The influence of protein and cation charges on the ligand polarization diminishes with the distance and is below 2 kcal/mol at 9 $\unicode{x212B}$ and 1 kcal/mol at 12 $\unicode{x212B}$. Considering both polarization and solvation appears essential to computing negative binding energies in some crystallographic complexes. Solvation, but not polarization, is essential for achieving moderate correlation with experimental binding free energies.

physics.chem-ph↗

arXiv2019

KeystoneDepth: Visualizing History in 3D

This paper introduces the largest and most diverse collection of rectified stereo image pairs to the research community, KeystoneDepth, consisting of tens of thousands of stereographs of historical people, events, objects, and scenes between 1860 and 1963. Leveraging the Keystone-Mast raw scans from the California Museum of Photography, we apply multiple processing steps to produce clean stereo image pairs, complete with calibration data, rectification transforms, and depthmaps. A second contribution is a novel approach for view synthesis that runs at real-time rates on a mobile device, simulating the experience of looking through an open window into these historical scenes. We produce results for thousands of antique stereographs, capturing many important historical moments.

cs.CV↗