99 research outputs found
3D building change detection using high resolution stereo images and a GIS database
In this paper, a workflow is proposed to detect 3D building changes in urban and sub-urban areas using high-resolution stereoscopic satellite images of different epochs and a GIS database. Semi-global matching (SGM) is used to derive Digital Surface Models (DSM) and subsequently normalised digital surface models (nDSM, the difference of a DSM and a digital elevation model (DEM)), from the stereo pairs at each epoch. Large differences between the two DSMs are assumed to represent height changes. In order to reduce the effect of matching errors, heights in the nDSM of at least one epoch must also lie above a certain threshold in order to be considered as candidates for building change. A GIS database is used to check the existence of buildings at epoch 1. As a result of geometric discrepancies during data acquisition caused by different view directions and illumination conditions, the outlines of existing buildings do not necessarily match even in non-changed areas. Consequently, in the change map, there are streaking-shaped structures along the building outlines which do not correspond to actual changes. To eliminate these effects morphologic filtering is applied. The mask we use operates as a threshold on the shape and size of detected new blobs and effectively removes small objects such as cars, small trees and salt and pepper noise. The results of the proposed algorithm using IKONOS and GeoEye images demonstrate its performance for detecting 3D building changes and to extract building boundaries.DAA
IAQ in Hospitals - Better Health through Indoor Air Quality Awareness
Quality air is fundamental to people's health and well-being. Indoor air quality is an important issue from both a social and economic point of view. Continual advances in medicine and technology necessitate constant reevaluation of the air-conditioning needs of hospital and medical facilities. The application of air conditioning to health facilities presents many problems not encountered in the usual comfort air conditioning design. Hospital air conditioning assumes a more important role than just the promotion of comfort. Studies show that patients in controlled environment generally have more rapid physical improvement than do those in uncontrolled environment. Air quality at hospitals needs special precautions during design and maintenance stage to prevent infections from spreading. 50% of all illnesses are either caused by, or aggravated by, polluted indoor air. The main objective of this paper is to critically review and summarize the available information about IAQ particularly in health care industries. Symptoms of poor IAQ in a building, contaminants causing poor IAQ, features of HVAC systems for a hospital for better IAQ are briefly discussed in this paper. Strategies to improve indoor air quality in hospitals and the current international research to improve indoor air quality are reported in this paper. Based on the extensive interactions with different stake holders of a hospital it is concluded that maintenance of proper indoor quality in a hospital needs meticulous team work among the various members of the hospital at various stages
Building monitoring with differential dsms
The monitoring of building activity (erection of new buildings, demolishing buildings and especially the change of building heights) by manual inspection of space and aerial images is time consuming and a source of errors. A detection of building changes based on the comparison of digital surface models (DSMs) is more reliable. For this study DSMs have been generated based on aerial images, an IKONOS and a GeoEye-1 stereo pair taken from 2007 up to 2009. By pixel based matching with dynamic programming, semiglobal matching and least squares matching the visible surface has been determined. Semiglobal matching leads to sharp building shapes, while the area based least squares matching smoothes the height model and has more problems in areas with little or without contrast. As is shown in the investigation building changes and building height changes in the range of one floor can in many cases be determined with all methods, however building shapes are better determined using semiglobal matching
Brachytherapy of stage II mobile tongue carcinoma. Prediction of local control and QOL
BACKGROUND: There is no consensus as to the prognostic model for brachytherapy of tongue carcinoma. This study was designed to evaluate the prognostic factors for local control based on a large population under a unified treatment policy. RESULTS: Between 1970 and 1998, 433 patients with stage II tongue squamous cell carcinoma were treated by low-dose-rate brachytherapy. This series included 277 patients treated with a linear source with a minimum follow-up of 3 years. A spacer was introduced in 1987. The primary local control rates were 85.6%. CONCLUSION: In the multivariate analysis, an invasive growth pattern was a significant factor for local recurrence. The disease-related survival was influenced by old age and an invasive growth pattern. A spacer lowered mandibular bone complications. The growth pattern was the most important factor for recurrence. Brachytherapy was associated with a high cure rate and the use of spacers brought about good quality of life (QOL)
Career mobility in a global era: advances in managing expatriation and repatriation
The surge of interest in expatriation and repatriation within the broader discourse on labor mobility of professionals and high-skilled labor, human capital development and the theory and practice of people management, serves as the backdrop to this paper. We propose that expatriation and repatriation be framed in the context of global careers and embedded in the wider social-economic environment of globalization through the lens of a career ecosystem theory. We chart the evolution of scholarly publications on career mobility over the past four decades and highlight current trends, in particular the emergence of self-initiated expatriation as a pivotal change in the direction of expatriation studies and derived practice. We assess the rigor of empirical findings, weigh theoretical underpinnings, offer a research agenda for future research and outline managerial implications
Oral squamous cell cancer: early detection and the role of alcohol and smoking
Objective: Oral squamous cell carcinoma has a remarkable incidence worldwide and a fairly onerous prognosis, encouraging further research on factors that might modify disease outcome. Data sources: A web-based search for all types of articles published was initiated using Medline/Pub Med, with the key words such as oral cancer, alcohol consumption, genetic polymorphisms, tobacco smoking and prevention. The search was restricted to articles published in English, with no publication date restriction (last update 2010). Review Methods: In this review article, we approach the factors for a cytologic diagnosis during OSCC development and the markers used in modern diagnostic technologies as well. We also reviewed available studies of the combined effects of alcohol drinking and genetic polymorphisms on alcohol-related cancer risk. Results: The interaction of smoking and alcohol significantly increases the risk for aero-digestive cancers. The interaction between smoking and alcohol consumption seems to be responsible for a significant amount of disease. Conclusion: Published scientific data show promising pathways for the future development of more effective prognosis. There is a clear need for new prognostic indicators, which could be used in diagnostics and, therefore a better selection of the most effective treatment can be achieved
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