Fuzzy Intervals for Designing Structural Signature: An Application to Graphic Symbol Recognition

Revised selected papers from Eighth IAPR International Workshop on Graphics RECognition (GREC) 2009.The motivation behind our work is to present a new methodology for symbol recognition. The proposed method employs a structural approach for representing visual associations in symbols and a statistical classifier for recognition. We vectorize a graphic symbol, encode its topological and geometrical information by an attributed relational graph and compute a signature from this structural graph. We have addressed the sensitivity of structural representations to noise, by using data adapted fuzzy intervals. The joint probability distribution of signatures is encoded by a Bayesian network, which serves as a mechanism for pruning irrelevant features and choosing a subset of interesting features from structural signatures of underlying symbol set. The Bayesian network is deployed in a supervised learning scenario for recognizing query symbols. The method has been evaluated for robustness against degradations & deformations on pre-segmented 2D linear architectural & electronic symbols from GREC databases, and for its recognition abilities on symbols with context noise i.e. cropped symbols

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

Experimental Feasibility Study of Fiber Optic Extrinsic Fabry-Perot Interferometric Sensor for Civil Structures and other Applications

An experimental bench set up of a fibre optic Extrinsic Fabry-Perot Interferometer (EFPI) sensor was realised and its feasibility demonstrated in an open configuration. The basic interferometric coupling between the sensing and reference reflections from a Fabry Perot (FP) air cavity realised between two fibre ends was so achieved that the sensor exhibits extreme sensitivity to external disturbances. The study reports about the salient features, scope, operating principle, and details of the experimental set-up of a fibre optic EFPI. The results of qualitative studies undertaken for sensing vibrations due to external disturbances under different situations and its further refinement/modifications for applications in health monitoring of structures are also discussed

Development of a Fiber Optic based System to Monitor Landslide Activity

Optical Time Division Reflectometery (OTDR) was originally developed to detect breaks/ losses in optical fiber transmission cables. Its use for monitoring land mass deformation has not been exploited so far. An experimental set up of a Fiber Optic System using OTDR to Monitor Landslide Activity was realised demonstrating this capability. The feasibility study used in an open configuration wherein an OTDR was used for interrogating the optical fiber subjected to a physically simulated micro-bending likely to be caused by landslide activity Distance estimations of micro-bend locations derived from the OTDR traces so obtained, were analysed using serial interface for the Computer and Tek FMTAP software. These were compared with actual physical distances. The paper reports the salient features, scope, operating principle, and details of the experimental set-up of a proposed Fiber Optic System to Monitor Landslide Activity. Economic advantages of the proposed system over the traditional inclinometer method include: no need to physically visit the site for collection of data, inexpensive, less time consuming, easy installation, disposable cable, no need to clean debris from the inclinometer hole before taking measurements; and ability of remote monitoring at multiple locations. The application of the OTDR techniques employing optical fiber lor sensing landslide activity, its further refinement/modifications for remote monitoring are also discussed