Optimizing Multimodal Transportation Access to Support Commuting Among Low-Income Transit Riders with Social Distancing

During the COVID-19 pandemic, LA Metro has encouraged social distancing among passengers—especially at stations of high-demand routes—and has increased fixed-route transit (FRT) services. However, potential impacts of social distancing on the performance of FRT services remain mostly unknown. This research evaluates the accessibility of FRT buses with social distancing using the ridership data collected on four FRT routes: 105, 108, 111, and 115 of the LA Metro\u27s A Line stations located in low-income neighborhoods. This research shows that social distancing of six feet can impact FRT\u27s accessibility to destination stations, and maximum accessibility is achieved only for a certain number of stops served—which is less than the current number of stops served. The FRT routes 105, 108, 111 and 115 have maximum accessibility with social distancing for the number of stops served equal to 65, 52, 52 and 50, respectively. The methodology used in this research can help decision-makers understand how FRT bus frequencies are impacted by social distancing measures, and the results can guide the transit authorities developing FRT service among low-income commuters during and after the pandemic

A comparative study of Zn and Fe distribution in two contrasting wheat genotypes

Effect of zinc and iron interaction on their distribution was examined in two wheat genotypes (UP262 and UP2628) under foliar application of 0, 0.25 and 0.50% ZnSO4 solution tagged with 925 KBq of Zn65 pot-1 for Zn and 0, 0.5 and 1.0% FeSO4 solution tagged with 925 KBq of Fe59 pot-1 for Fe at 30, 60 and 90 days after planting. Maximum grain yield of UP2628 (2.7 g pot-1 ) was recorded at 0.5%ZnSO4+0%FeSO4 while that of UP262 (2.63 g pot-1 ) was recorded at 0.5%ZnSO4+1.0%FeSO4. The highest straw yield of UP2628 (2.75 g pot-1 ) was noted at 0.5% ZnSO4+1.0%FeSO4 while that of UP262 (2.91 g pot-1 ) with 0.5%ZnSO4+0.5%FeSO4. Application of 0.5% and 1.0% FeSO4 reduced the accumulation of 65Zn in all parts of both the varieties. Regarding the 59Fe accumulation, it was found to be decreased with the increased application of ZnSO4 solution from 0.25% and 0.5% as compared to without application of Zn. On comparing translocation efficiencies of both the varieties, UP2628 showed better translocation thus accumulated higher zinc and iron. Therefore, variety UP2628 can be used further for crop improvement programme

Evaluating Crowdsourcing as a VMT Reduction Tool to Support Smart Cities Initiatives

Vehicle miles traveled (VMT) is an indicator of vehicular emissions, which impacts climate change. Various stakeholders aim at reducing VMT to cause reductions in emissions. This research explores the use of crowdsourcing in supporting the efforts of the stakeholders in reducing VMT among college students at California State University Long Beach. Crowdsourcing is emerging as a very promising tool in finding solutions to problems otherwise impossible to solve without a collective human intelligence. A smartphone application is developed to collect travel data and behavior of 55 college students as participants. The behavior is tracked after providing advance information on parking availability on the university campus. It is observed that VMT reductions occur from Monday, Wednesday, and Thursday with car users and Monday through Thursday with transit bus users. The largest reduction of 4% occurs with car usage on Thursday. On the same day, the highest reduction in VMT of 5% occurs with bus usage. Thus, crowdsourcing information on campus parking showed that VMT reduction is effective with the small number of participants involved in this pilot study

Design and Optimization of a Feeder Demand Responsive Transit System in El Cenizo,TX

The colonias along the Texas-Mexico border are one of the most rapidly growing areas in Texas. Because of the relatively low income of the residents and an inadequate availability of transportation services, the need for basic social activities for the colonias cannot be properly met. The objectives of this study are to have a better comprehension of the status quo of these communities by examining the potential demand for an improved transportation service and evaluate the capacity and optimum service time interval of a new demand responsive transit "feeder" service within one representative colonia, El Cenizo. A comprehensive analysis of the results of a survey conducted through a questionnaire is presented to explain the existing travel patterns and potential demand for a feeder service. The results of this thesis and work from the subsequent simulation analysis showed that a single shuttle would be able to comfortably serve 150 passengers/day. It further showed that the optimal cycle length between consecutive departures from the terminal should be between 11-13 minutes for best service quality. This exploratory study should serve as a first step towards improving transportation services within these growing underprivileged communities especially those with demographics and geography similar to the target area of El Cenizo

Enhancing Livability with Feeder Transit Services: Formulation and Solutions to First/Last Mile Connectivity Problem

This dissertation begins with proposing a novel street Connectivity Indicator (C.I.) to predict transit performance by identifying the role that street network connectivity plays in influencing the service quality of demand responsive feeder transit services. This new C.I. definition is dependent upon the expected shortest path between any two nodes in the network, includes spatial features with transit demand distribution information and is easy to calculate for any given service area. Subsequently, a methodology to identify and locate critical links within a grid street system for operating feeder transit services is also developed. A 'critical' street link causes the largest change in transit performance due to the link's removal or addition to an existing network. The most important contribution of this section on link criticality is to present a simple closed-form analytical formula in locating the critical link(s) for a grid street network system of 'any' size. Easily computable formulas have been provided and validated by simulation analyses. Another related model is proposed to compute the optimal grid street spacing that would enhance performance of a demand responsive feeder transit system. The model is tested using simulation. Lastly, an analytical model is also developed for estimating optimal service cycle length or headway of a demand responsive feeder transit service designed to serve passengers, especially during peak periods of demand. Simulation analyses over a range of networks have been conducted to validate the new C.I. definition. Results show a desirable monotonic relationship between transit performance and the proposed C.I., whose values are directly proportional and therefore good predictors of the transit performance, outperforming other available indicators, typically used by planners. Further, useful insights indicate a monotonic decrease in link criticality as we depart from the centrally located links to those located at boundaries. Using a real case example from Denver of the Call-n-Ride system operating similar to a demand responsive feeder transit, optimal cycle lengths differed very modestly from those computed using the model. Extensive simulations performed for different sets of feeder service areas and demand densities, further validated the optimal cycle length model

An alarming but self-limited case of isolatedlarge spontaneous liver hematoma in pregnancy

Spontaneous subcapsular liver hematoma is rare but potentially life-threatening complication of pregnancy usually associated with severe preeclampsia and HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets). We present here a case of such a large spontaneous liver hematoma presenting in pregnancy, but without other known associated abnormalities, which has not been described before and it resolved on itself without any intervention.Pan African Medical Journal 2013; 14:3

ACTIVE INDUCTOR BASED LOW PHASE NOISE VOLTAGE CONTROLLED OSCILLATOR

This paper proposed a fully MOS-based voltage-controlled oscillator (VCO) with tuning range and low phase noise, replacing the most often used NMOS-based inductor-capacitor tank arranged in cross-coupled topology with a high-Q active inductor. This study mainly focuses on VCO design using a MOS-based active inductor and is implemented and verified using UMC 180nm CMOS technology. The proposed VCO is resistorless and consists of an active inductor, two MOS capacitors, and the buffer circuits. The fundamental principle of this MOS-based VCO concept is to use MOS based inductor to replace the passive inductor, which is an active inductor that gives less area and low power usage. At 1 MHz frequency offset, the phase noise achieved by this proposed configuration is -102.78dBc/Hz. In the proposed VCO architecture, the frequency tuning range is 0.5GHz to 1.7GHz. This VCO design can accomplish this acceptable tuning range by altering the regulating voltage from 0.7V to 1.8V. This suggested architecture of proposed VCO design has the power consumption of 9mW with a 1.8V supply voltage. The suggested VCO has been shown to be a good fit for low-power RF circuit applications while preserving acceptable performance metrics

Evaluating Innovative Financing Mechanisms for the California High-Speed Rail Project

Millions of dollars are involved in high-speed rail (HSR) infrastructure construction and maintenance. Large-scale projects like HSR require funding from a variety of avenues beyond those available through public monies. Although HSR serves the general public’s mobility needs, any funds (whether State or Federal) flowing from the public exchequer usually undergo strict review and scrutiny. Funds from public agencies are always limited, making such traditional financing mechanisms unsustainable for fulfilling HSR’s long-term operational and maintenance cost needs—on top of initial costs involved in construction. Therefore, any sustainable means of financing HSR projects would always be welcome. This research presents an alternate revenue generation mechanism that could be sustainable for financing HSR’s construction, operation, and maintenance. The methodology involves determining key HSR stations, which, after development and improvement, could significantly add value to businesses and real estate growth. Any form of real estate taxes levied on properties surrounding such stations could substantially support the HSR project’s funding needs. In this research, a bi-objective optimization problem is posed in conjunction with a Pareto-optimal front framework to identify those key stations. With 28 California HSR stations used as an example, it was observed that the four proposed HSR stations in Fullerton, Millbrae-SFO, San Francisco Transbay Terminal, and San Diego would be excellent candidates for development. Their development could increase the economic vitality of surrounding businesses. The findings could serve as valuable information for California HSR authorities to focus on developing key stations that would generate an alternate funding source for an HSR project facing funding challenges

Evaluating Automated Truck Platoon (ATP) Deployment for the Los Angeles–Inland Empire Trade Corridor Enhancement

The California Freight Mobility Plan 2020 lists the Los Angeles-Inland Empire trade corridor region as a prominent industrial hub experiencing an increase in freight flows. The California Freight Mobility Plan also regards automated truck platoon (ATP) as an emerging opportunity to minimize congestion on the trade corridor routes. Percentage change in accessibility from 2022 (“without” ATP) to 2040 (“with” ATP) is calculated for the eighteen industry sectors of the Los Angeles-Inland Empire trade corridor. The application of the accessibility formulation was carried out with data on travel time from I-710 and I-10 within Los Angeles County. The findings suggest that all the industry sectors have a very high positive percentage change in accessibility by transforming from “without” to “with” ATP deployment-based accessibility. In the vicinity of the prominent freight corridors of I-710 and I-10 within Los Angeles County, notably, the largest increase in accessibility above 90% will be observed for the industry sectors of Agriculture, Forestry, Fishing and Hunting, Health Care and Social Assistance, Finance and Insurance, Transportation and Warehousing, and Retail Trade of the Los-Angeles-Inland Empire. Thus, these findings suggest the deployment of ATP on specific freight routes to enhance and sustain economic activity across the Los Angeles-Inland Empire trade corridors

Dynamic Response of Brain Subjected to Blast Loadings: Influence of Frequency Ranges

Blast wave induced a frequency spectrum and large deformation of the brain tissue. In this study, new material parameters for the brain material are determined from the experimental data pertaining to these large strain amplitudes and wide frequencies ranging (from 0.01 Hz to 10 MHz) using genetic algorithms. Both hyperelastic and viscoelastic behavior of the brain are implemented into 2D finite element models and the dynamic responses of brain are evaluated. The head, composed of triple layers of the skull, including two cortical layers and a middle dipole sponge-like layer, the dura, cerebrospinal fluid (CSF), the pia mater and the brain, is utilized to assess the effects of material model. The results elucidated that frequency ranges of the material play an important role in the dynamic response of the brain under blast loading conditions. An appropriate material model of the brain is essential to predict the blast-induced brain injury