An analysis of short haul airline operating costs

The demand and supply characteristics of short haul air transportation systems are investigated in terms of airline operating costs. Direct, indirect, and ground handling costs are included. Supply models of short haul air transportation systems are constructed

A Comparison of the Social Costs of Air and Highway

This paper provides a comprehensive survey of the literature on the measures of social costs, providing an indication of the state of engineering and economic literature. We operationalize the new thinking about which externalities seem appropriate to consider in an analysis of the transportation system. We construct measures of each externality: noise, air pollution, accidents, and congestion for the highway and air transportation modes, where possible as a function of the amount of output or use, rather than as simple unit costs. We find that noise is the dominant cost of air travel, followed by congestion, air pollution and accidents. For highway travel, accidents are the most significant cost, followed by congestion, noise, and air pollution. The social costs of highway travel are about 15 percent of the full cost of a highway trip, while the smaller social costs of air travel are only 5 percent of the full cost of an air trip. A highway trip generates four to five times as much externality as an air trip. .

The Full Cost of High-Speed Rail: An Engineering Approach

This paper examines the full costs, defined as the sum of private and social costs, of a high speed rail system proposed for a corridor connecting Los Angeles and San Francisco in California. The full costs include infrastructure, fleet capital and operating expenses, the time users spend on the system, and the social costs of externalities, such as noise, pollution, and accidents. Comparing these full costs to those of other competing modes contributes to the evaluation of the feasibility of high speed rail in the corridor. The paper concludes that high speed rail is significantly more costly than expanding existing air service, and marginally more expensive than auto travel. This suggests that high speed rail is better positioned to serve shorter distance markets where it competes with auto travel than longer distance markets where it substitutes for air. .

Measures to increase airfield capacity by changing aircraft runway occupancy characteristics

Airfield capacity and aircraft runway occupancy characteristics were studied. Factors that caused runway congestion and airfield crowding were identified. Several innovations designed to alleviate the congestion are discussed. Integrated landing management, the concept that the operation of the final approach and runway should be considered in concert, was identified as underlying all of the innovations

Burkholderia cepacia Vertebral Osteomyelitis Following Cesarean Section: Case Report and Review of the Literature

The Burkholderia cepacia complex (Bcc) initially emerged as an important opportunistic pathogen in patients with predisposing lung disease. Bcc infections outside the respiratory tract are less common, although their incidence has been increasing particularly in immunocompromised patients. We herein describe the case of a healthy young woman who started experiencing low back pain 2 weeks after an uncomplicated cesarean section. She was found to have vertebral osteomyelitis at T12-L1. CT guided biopsy was performed, and cultures grew Bcc. She was treated with 3 weeks of meropenem and 5 weeks of oral trimethoprim-sulfamethoxazole with good response. No surgical intervention was warranted. We also performed a review of the literature on other existing reports. To the best of our knowledge, this is the first case of Bcc vertebral osteomyelitis in an immunocompetent patient following an obstetric procedure

The Economics of Speed – Assessing the performance of High Speed Rail in Intermodal Transportation

AbstractThis study is an attempt to explore the benefit and cost of ‘speed’ on the performance of High Speed Rail. The discussion is put in the context of multimodal transportation system. Physical intuition leads us to suspect that operating cost increases nonlinearly with speed. However, the scenario is way more complicated in engineering operation. The revealed result suggests that the nonlinear increase in cost is most significant when operating maximum speed exceeds the 200 kph threshold. It also suggests that the efficiency gain from increased speed has the potential to compensate the increased cost requirement

ANN and Adaboost application for automatic detection of microcalcifications in breast cancer

AbstractObjectiveMicrocalcifications or MCs are considered to be the basic symptoms present in mammograms for breast cancer diagnosis. Therefore, the accurate detection of MCs is mandatory for the on-time diagnosis, effective treatment and reduction of mortality rates due to breast cancer. Mammogram analysis and interpretation is a challenging task, and there are many obstructions to the accurate detection of MCs such as small and non-uniform shape and size of the MCs clusters in addition to low contrast quality of MCs as compared to the rest of the tissue. These shortcomings of manual interpretation of MCs raise the need for an automatic detection system to assist radiologists in mammogram analysis. In this study, an automated system has been developed to minimize the manual inference and diagnose breast cancer with good precision. In this paper, we propose a two-fold detection algorithm. In the first stage, all suspicious regions from the mammogram are segmented out. In the next stage, these suspected regions are fed to a classifier which then detects whether the region was normal, benign or malignant. We compared the performance of a Neural Network classifier with Adaboost. ANN classifier shows more sensitivity and specificity but less accuracy as compared to Adaboost for tested images. Overall results show that the developed algorithm is able to achieve high accuracy and efficiency for the detection and diagnosis of breast cancer lesions for images from two different databases used, and also for mammograms obtained from a local hospital.ConclusionThe suggested algorithm was tested for DDSM, MIAS and local database and showed high level of overall accuracy (98.68%) and sensitivity (80.15%)