Three Essays on Contract Renegotiation

This dissertation is a collection of three essays investigating renegotiation of procurement auctions in the road construction industry. The empirical analysis uses contracts procured by the Vermont Agency of Transportation from 2004 to 2009. In practice, these adjustments, frequently attributed to incomplete contracts, are observed in sizable and complex procurement projects. As a consequence there are significant differences between contract amounts and final payments to a contractor due to ex post changes. In addition, it is possible that firm's bidding strategies are influenced by the anticipation of change orders, with negative effects on the efficiency and overall cost of highway construction programs. First we investigate the impacts of ex post renegotiations on ex ante bidders' bidding behaviors and their markups and costs. In particular, we consider a set of adjustment types such as quantity adjustments and extra work adjustments which are common in the field. Then we analyze the factors associated with the frequency of change orders. In the first essay, we focus on ex ante bidder's strategic bidding behavior in anticipation of ex post contract renegotiation. The empirical analysis shows that the magnitude of estimated markups is systematically higher for projects with positive quantity adjustments than those without such renegotiations. The second essay continues the study of the impact of incomplete contracts that requires ex post extra work on procurement costs. We find this unique compensation process causes significant adaptation costs at the renegotiation stage, which provides contractors with markups similar to those they would earn in projects without renegotiations at all. In the last essay, we investigate the reasons for the frequency and magnitude of renegotiations in the Vermont transportation contracts. We show that project uncertainty and complexity and bidding behaviors are valuable predictors of renegotiations. All these studies are about public procurement in the transportation industry. Every essay provides a transportation department with relevant policy implications. This study has the potential to increase the efficiency of budgetary planning for the transportation department, and reduce costs to the tax payers. Our empirical analysis shows that bidder's strategic bidding and adaptation costs associated with renegotiating a contract could increase the procurement costs. Therefore, it may be preferable for the procuring agency to invest more time in providing more completed designs rather than to proceed with the project and deal with renegotiations ex post

The impact of regional competition on the health care industry

We investigate factors that determine firm markups by employing data on prices and quantities of various medical procedures at major hospitals in the United States. We focus on the impact of hospital quality, rival competition and the number of medical procedures upon the health care demand. Our analysis covers health-care markets across the United States with the market definition based upon the hospital referral regions. Our findings highlight potential implications of the relationship between hospital markups and market structure

Dynamic All-Red Signal Control Based on Deep Neural Network Considering Red Light Runner Characteristics

Despite recent advances in technologies for intelligent transportation systems, the safety of intersection traffic is still threatened by traffic signal violation, called the Red Light Runner (RLR). The conventional approach to ensure the intersection safety under the threat of an RLR is to extend the length of the all-red signal when an RLR is detected. Therefore, the selection of all-red signal length is an important factor for intersection safety as well as traffic efficiency. In this paper, for better safety and efficiency of intersection traffic, we propose a framework for dynamic all-red signal control that adjusts the length of all-red signal time according to the driving characteristics of the detected RLR. In this work, we define RLRs into four different classes based on the clustering results using the Dynamic Time Wrapping (DTW) and the Hierarchical Clustering Analysis (HCA). The proposed system uses a Multi-Channel Deep Convolutional Neural Network (MC-DCNN) for online detection of RLR and also classification of RLR class. For dynamic all-red signal control, the proposed system uses a multi-level regression model to estimate the necessary all-red signal extension time more accurately and hence improves the overall intersection traffic safety as well as efficiency. © 2020 by the authors.1

Small non-coding RNA profiling and the role of piRNA pathway genes in the protection of chicken primordial germ cells

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Background Genes, RNAs, and proteins play important roles during germline development. However, the functions of non-coding RNAs (ncRNAs) on germline development remain unclear in avian species. Recent high-throughput techniques have identified several classes of ncRNAs, including micro RNAs (miRNAs), small-interfering RNAs (siRNAs), and PIWI-interacting RNAs (piRNAs). These ncRNAs are functionally important in the genome, however, the identification and annotation of ncRNAs in a genome is challenging. The aim of this study was to identify different types of small ncRNAs particularly piRNAs, and the role of piRNA pathway genes in the protection of chicken primordial germ cells (PGCs). Results At first, we performed next-generation sequencing to identify ncRNAs in chicken PGCs, and we performed ab initio predictive analysis to identify putative piRNAs in PGCs. Then, we examined the expression of three repetitive sequence-linked piRNAs and 14 genic-transcript-linked piRNAs along with their linked genes using real-time PCR. All piRNAs and their linked genes were highly expressed in PGCs. Subsequently, we knocked down two known piRNA pathway genes of chicken, PIWI-like protein 1 (CIWI) and 2 (CILI), in PGCs using siRNAs. After knockdown of CIWI and CILI, we examined their effects on the expression of six putative piRNA-linked genes and DNA double-strand breakage in PGCs. The knockdown of CIWI and CILI upregulated chicken repetitive 1 (CR1) element and RAP2B, a member of RAS oncogene family, and increased DNA double-strand breakage in PGCs. Conclusions Our results increase the understanding of PGC-expressed piRNAs and the role of piRNA pathway genes in the protection of germ cells

Revealing dual radio sources in a sub-kpc-scale binary active galactic nucleus candidate

We present new VLA and e-MERLIN imaging of a sub-kpc-scale binary active galactic nuclei (AGN) candidate. Two unresolved radio sources of similar luminosity around 1022 WHz−1 are identified in ∼35 hrs of e-MERLIN 6cm imaging. These radio sources have an angular separation and position angle of 0.19±0.06” and PA 22±10○, corresponding to a projected separation of 0.95±0.29 kpc at the epoch of the source. Our results suggest the presence of a kpc-scale active black hole pair hosted by two galaxies in the late stage of a merger at z = 0.35. This work follows Woo et al (2014) which presented two optical sources with a similar separation and position angle, and a velocity separation of 200 km s−1. Our target adds to the currently limited sample of close-separation binary AGN that will aid in understanding the frequency of mergers and the stochastic gravitational wave background

Cetaceans evolution:insights from the genome sequences of common minke whales

Background: Whales have captivated the human imagination for millennia. These incredible cetaceans are the only mammals that have adapted to life in the open oceans and have been a source of human food, fuel and tools around the globe. The transition from land to water has led to various aquatic specializations related to hairless skin and ability to regulate their body temperature in cold water. Results: We present four common minke whale (Balaenoptera acutorostrata) genomes with depth of ×13 ~ ×17 coverage and perform resequencing technology without a reference sequence. Our results indicated the time to the most recent common ancestors of common minke whales to be about 2.3574 (95% HPD, 1.1521 - 3.9212) million years ago. Further, we found that genes associated with epilation and tooth-development showed signatures of positive selection, supporting the morphological uniqueness of whales. Conclusions: This whole-genome sequencing offers a chance to better understand the evolutionary journey of one of the largest mammals on earth

How does fine particulate matter impact public transit ridership?

We explore how a rapid rise in air pollutants impacts the ridership of public transportation. Based on the individual purchase history, our comprehensive analyses document evidence that an elevated level of concentrations of fine particulate matter caused a substantial change in individual decisions on public transit ridership in relation to individual social and economic characteristics. The estimated effect primarily arose from the fear of exposure to pollutants and, consequently, is substantially different from other macroeconomic influences. Our empirical results contribute important inferences about commuters’ choices of transit modes during the period of ambient air pollution and offer significant guidance for policymakers and practitioners

Control of AWD System for Vehicle Performance and Safety

AWD (All-Wheel Drive) system transfers drive force to all wheels so that it can help vehicle escape low mu surface or climb hill more conveniently. Recently, AWD system for on road vehicle has become popular to improve vehicle driving performance. However, there has not been enough research of applying AWD system for vehicle stability especially for lateral movement. Compared with ESC (Electronic Stability Control), AWD system does not cause any inconveniences to the driver because it controls vehicle only by distributing front and rear drive torque, without using brake. By allowing slipping/locking of wet clutch inside the transfer case, AWD system can distribute different amount of torque between front and rear axle. This paper introduces modelling of AWD system and suggests the control of AWD system based on peak slip ratio and slip angle at which tyre saturates. Carsim based vehicle simulation results of AWD controller is presented