City University London

About: City University London is a education organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 5735 authors who have published 17285 publications receiving 453290 citations.

Multidimensional Geographic Information Science

Abstract: Geographic Information Systems mainly tend to be two dimensional, thus limiting the applications. As GIS are being developed, researchers and practioners are finding new ways of making GIS three dimensional, even four dimensional in some instances, increasing their usability. This book focuses on the way in which GIS could be made `multidimensional' based on the modelling limitations of current 2D GIS. It suggests extending GIS to incorporate the third and fourth dimensions, as well as time (spatio-temporal GIS), using a variety of programming techniques and discusses current examples of multidimensional GIS.

A Randomized Trial Comparing Treatments for Varicose Veins

Abstract: BACKGROUND Ultrasound-guided foam sclerotherapy and endovenous laser ablation are widely used alternatives to surgery for the treatment of varicose veins, but their comparative effectiveness and safety remain uncertain. METHODS In a randomized trial involving 798 participants with primary varicose veins at 11 centers in the United Kingdom, we compared the outcomes of foam, laser, and surgical treatments. Primary outcomes at 6 months were disease-specific quality of life and generic quality of life, as measured on several scales. Secondary outcomes included complications and measures of clinical success. RESULTS After adjustment for baseline scores and other covariates, the mean disease-specific quality of life was slightly worse after treatment with foam than after surgery (P = 0.006) but was similar in the laser and surgery groups. There were no significant differences between the surgery group and the foam or the laser group in measures of generic quality of life. The frequency of procedural complications was similar in the foam group (6%) and the surgery group (7%) but was lower in the laser group (1%) than in the surgery group (P<0.001); the frequency of serious adverse events (approximately 3%) was similar among the groups. Measures of clinical success were similar among the groups, but successful ablation of the main trunks of the saphenous vein was less common in the foam group than in the surgery group (P<0.001). CONCLUSIONS Quality-of-life measures were generally similar among the study groups, with the exception of a slightly worse disease-specific quality of life in the foam group than in the surgery group. All treatments had similar clinical efficacy, but complications were less frequent after laser treatment and ablation rates were lower after foam treatment. (Funded by the Health Technology Assessment Programme of the National Institute for Health Research; Current Controlled Trials number, ISRCTN51995477.)

Experimental design and analysis in software engineering

Abstract: The paper presents key activities necessary for designing and analyzing an experiment in software engineering. After explaining how to choose an appropriate research technique to fit project goals, the paper shows how to state a hypothesis and determine how much control is needed over the variables involved. If control is not possible, then a formal experiment is not possible; a case study may be a better approach. Next, the six stages of an experiment (conception, design, preparation, execution, analysis and dissemination) are described, with design examined in detail. Design considerations such as replication, randomization and local control are discussed, and design techniques such as crossing and nesting are explained. Finally, data analysis is shown to be a function both of the experimental design and the distribution of the data. Throughout, examples are given to show how the techniques are interpreted and used in software engineering.