Discourse models for collaboratively edited corpora

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 77-81).This thesis focuses on computational discourse models for collaboratively edited corpora. Due to the exponential growth rate and significant stylistic and content variations of collaboratively edited corpora, models based on professionally edited texts are incapable of processing the new data effectively. For these methods to succeed, one challenge is to preserve the local coherence as well as global consistence. We explore two corpus-based methods for processing collaboratively edited corpora, which effectively model and optimize the consistence of user generated text. The first method addresses the task of inserting new information into existing texts. In particular, we wish to determine the best location in a text for a given piece of new information. We present an online ranking model which exploits this hierarchical structure - representationally in its features and algorithmically in its learning procedure. When tested on a corpus of Wikipedia articles, our hierarchically informed model predicts the correct insertion paragraph more accurately than baseline methods. The second method concerns inducing a common structure across multiple articles in similar domains to aid cross document collaborative editing. A graphical model is designed to induce section topics and to learn topic clusters. Some preliminary experiments showed that the proposed method is comparable to baseline methods.by Erdong Chen.S.M

Updating RoadHAT: Collision Diagram Builder and HSM Elements

In order to minimize the losses resulting from traffic crashes, Indiana developed its road safety management methods before the Highway Safety Manual and the SafetyAnalyst became available. This study includes two related but distinct components: (1) comparison of the HSM-based and Indiana methods of safety management, and (2) development of a Collision Diagram Builder (CDB) to improve current Indiana safety management tools. This study concluded that the HSM SPFs would need to be calibrated to the Indiana conditions before they could be used. Calibrating the SPFs for so-called base conditions would lead to an insufficient number of roads and, consequently, to estimates that were not trustworthy. An advanced statistical simulation of a safety management system aimed to maximize the total safety benefit was performed. The results indicate that two best performing criteria: the HSM EPDO-based criterion and the Indiana total cost of crashes criterion are equivalent and they produce the same results. It is important that the HSM provides guidance as to which screening criteria support which screening objectives because some of the HSM criteria were found inadequate for maximizing the overall safety benefit. It also was concluded that although the cost of crashes and the Index of Crash Cost and Frequency used separately proved to be good screening criteria in Indiana, the combined use of these two measures did not deliver any considerable improvement. Two differences were found between the HSM and Indiana procedures for evaluating the benefits and costs of safety projects: the infinite period of analysis and the road capacity constraint on traffic growth. The differences between the two methods were quite limited and they could be fully reconciled if the capacity constraints was relaxed in the Indiana method and a long analysis period assumed in the HSM method. A second major component of the study was to improve the current Indiana safety management tool, RoadHAT2, by developing a computer application facilitating preparation of a so-called collision diagram. These diagrams are an important element of safety audits. The developed application reduces this time from one or two days to an hour or less. The application also provides additional tools for analyzing and visualization of crash patterns. A developed CDB User Manual introduces the user to the tool and provides examples to help the user get familiar with the application

Use of Barriers in Rural Open Road Conditions—A Synthesis Study

The use of wide medians and clear zones that do not require median and roadside barriers is the current design practice for new and reconstructed rural highway facilities. Constructing or reconstructing roads with full-width medians and clear zones is much more expensive today compared to when the design standards were developed. Considerable costs can be accrued in additional overhead bridge length, earthwork and ROW in new construction projects, and widening of existing right–of-way and bridge structures in reconstruction projects. This synthesis study focuses on the use of median barriers and roadside barriers and it identifies: (a) the current design practice and the existing body of knowledge, (b) (b) design conditions where adding extra traffic lanes without widening the ROW is acceptable from the point of view of safety and costs if barriers and guardrails are installed, and (c) future research needs. One of the practical outcomes of the project is a set of Crash Cost Modification Factors (concept found in the German design guidelines) estimated based on the past research for Indiana and simulation experiments executed with the Roadside Safety Analysis Program. These factors can be used to evaluate the safety benefit produced by a modified cross-section of a rural freeway

Best Practices for INDOT-Funded Work Zone Police Patrols

Transportation agencies across the U.S. are expending a great deal of effort to improve highway work zone safety. Among those efforts is a special fund for work zone enforcement established by the Indiana Department of Transportation (INDOT). The allocation of enforcement funding was based on expert knowledge and weights and scores applied to work zone characteristics considered relevant to traffic safety. The objective of the reported project was to develop a rational and defendable tool for programming police enforcement that maximizes the safety benefits of police enforcement in INDOT work zones. To understand what affects work zone safety, the research team carried out an extensive literature review, designed field experiments to evaluate the effect of selected enforcement strategies on drivers’ behavior in work zones, and developed speed models incorporating the effect of police enforcement. The estimated speeds were used to derive CMFs that express the effect of the police enforcement strategy on work zone safety. Finally, the research team combined all of the developed components in a method of predicting the costs and the safety benefits in works zones under various enforcement strategies. This last method was included in the optimization tool for programming police enforcement in a group of planned work zones. The described project developed an optimization tool implemented in a Microsoft Excel spreadsheet with the OpenSolver add-in. The tool is flexible, straightforward, and easy to use. The user should be able to quickly become familiar with the required input, results, and obtained solution

Modeling motorists\u27 speed and its impact on highway work zone safety for programming police enforcement

Highway work zone safety has been a major concern for transportation agencies, especially at a time when a great number of maintenance projects are needed for the aging U.S. highway system. State transportation agencies have made various efforts recently to improve safety in their work zones, including implementation of police enforcement to deter speeding, aggressive driving, and other dangerous driving behaviors, with the ultimate goal of reducing crashes and improving traffic operations within their work zones. Prior to the work of this dissertation, there was a considerable gap between the existing body of literature and a thorough understanding of how police enforcement affects motorists\u27 speed behaviors and how these behaviors affects highway work zone safety. In order to achieve the best safety benefits from such enforcement activities in work zones, research was needed to fill this gap. Thus, the research efforts of this dissertation had the following objectives: 1) to achieve a better understanding of highway work zone safety issues; 2) to understand how various police enforcement strategies affect driving behavior in work zones; and 3) to develop the Police Enforcement Programming Tool to assist state DOTs in optimizing their work zone enforcement activities. To achieve these objectives, the authors identified several tasks: (1) Estimate crash models, to gain better understanding about work zone crashes; (2) Conduct work zone police enforcement experiment, analyze driving behavior, and evaluate the effectiveness of various enforcement strategies; (3) Linking change in driving behavior and traffic safety, and develop an integrated tool for programming work zone police enforcement. All these objectives were satisfactorily achieved and the impact of this study is expected to extend to both academia and practice. During the work zone crash modeling, an unprecedented dataset was assembled, enabling very comprehensive analyses of work zone crashes and thereby adding new insights to the body of literature. The Police Enforcement Experiment of this dissertation included a wide variety of factors in a systematically designed setting and is the best-designed such study to date. Also, statistically significant conclusions were obtained from the subsequent advanced modeling analyses, which significantly improved the understanding of motorists\u27 behaviors in work zones in response to police enforcement. All the research findings were incorporated in the Crash Modification Factors and the implementation-ready Police Enforcement Programming Tool, which has been delivered to the Indiana Department of Transportation and is expected to make a substantial impact for practice

A Narrative Review on Perioperative Pain Management Strategies in Enhanced Recovery Pathways—The Past, Present and Future

Effective pain management is a key component in the continuum of perioperative care to ensure optimal outcomes for surgical patients. The overutilization of opioids in the past few decades for postoperative pain control has been a major contributor to the current opioid epidemic. Multimodal analgesia (MMA) and enhanced recovery after surgery (ERAS) pathways have been repeatedly shown to significantly improve postoperative outcomes such as pain, function and satisfaction. The current review aims to examine the history of perioperative MMA strategies in ERAS and provide an update with recent evidence. Furthermore, this review details recent advancements in personalized pain medicine. We speculate that the next important step for improving perioperative pain management could be through incorporating these personalized metrics, such as clinical pharmacogenomic testing and patient-reported outcome measurements, into ERAS program

6th Road Safety on Four Continents Conference PROGRAMMING POLICE ENFORCEMENT IN HIGHWAY WORK ZONES

ABSTRACT Due to the aging U.S. highway system and the frequent presence of work zones, highway work zone safety is garnering increasing attention. Police enforcement is sometimes used by U.S. transportation agencies for safety improvement in work zones. The important question that must be answered by those responsible for programming police enforcement in work zones is: where, when and how to enforce? This paper presents a research conducted by the Purdue Center for Road Safety (CRS) for the Indiana Department of Transportation (INDOT) aimed to develop a tool for selecting work zones, periods of enforcement, and enforcement strategies that maximize the safety benefit within the available budget. This research included modeling of the crash frequency in work zones to better understand work zone safety factors and evaluating several police enforcement strategies through a carefully designed police enforcement experiment in selected work zones. The study has confirmed several findings of the previous studies and it has provided new results such as finding that Variable Message Sign units are highly effective in reducing drivers' speed inside work zones. The practical outcome of this effort described in this paper is the Work Zone Police Enforcement Programming Tool (PEPT) used by INDOT to program cost-effective police enforcement activities. 16th Road Safety on Four Continents Conferenc

Programming Police Enforcement in Highway Work Zones

Police enforcement is sometimes used by U.S. transportation agencies for safety improvement in work zones. The important question that must be answered by those responsible for programming police enforcement in work zones is: where, when and how to enforce? This paper presents a research conducted by the Purdue Center for Road Safety (CRS) for the Indiana Department of Transportation (INDOT) aimed to develop a tool for selecting work zones, periods of enforcement, and enforcement strategies that maximize the safety benefit within the available budget. This research included modeling of the crash frequency in work zones to better understand work zone safety factors and evaluating several police enforcement strategies through a carefully designed police enforcement experiment in selected work zones. The study has confirmed several findings of the previous studies and it has provided new results such as finding that Variable Message Sign units are highly effective in reducing drivers’ speed inside work zones. The practical outcome of this effort described in this paper is the Work Zone Police Enforcement Programming Tool (PEPT) used by INDOT to program cost-effective police enforcement activities