Automatic object recognition and change detection of urban trees

Monitoring of tree objects is relevant in many current policy issues and relate to the quality of the public space, municipal urban green management, management fees for green areas or Kyoto protocol reporting and all have one thing in common: the need for an up to date tree database. This study, part of the Tree and Image research project, developed a database-driven approach for object recognition and change detection using optical imagery including contextual data from urban tree databases and topographic data. Trees are 3D objects and vary in shape throughout the season. The tree is modelled in a 2D aerial image using the point location and species information. The tree model consists of a projected crown and shadow. These projections, polygons, are used to recognise the object with NDVI and texture parameters related to the ground surface derived from the topographic map and its neighbouring segments. This resulted in classifications of trees ‘still present’ or ‘disappeared’ with an overall accuracy of 85%. However, the errors of commission and omission were quite high due to the use of an early image with no full-grown crowns, resulting in difficult recognisable trees. Detected changes can be used for further human verification or directly serve as input for database management and decision making.Remote SensingAerospace Engineerin

Improving 2D change detection by using available 3D data

Change detection with very high resolution imagery is difficult, because 3D objects as buildings appear differently in 2D imagery due to varying viewing angles and sun positions. This research proposes a method to improve change detection by using simple 3D models of buildings. Buildings have been modelled as flat roof or gable roof buildings. By knowing the position of the sun, the location of the shadow of a building is calculated. The location of the relief displacements is calculated using information on the position of the sensor. By introducing the projected shadow, relief displacement and roof in the automatic change detection process more reliable change signals are produced. An object-oriented approach for change detection is developed using segmentation techniques to create homogeneous segments from pixels. The method compares the object map t0 with the image t1. Information is gathered on how each object represents in the image t1 and at t0, by using the information of the image t0. In the case of shadow parts histogram stretched imagery are used. For the change detection on the roof, the roof segments are reprojected on top of each other to compare them. This method resulted in more reliable change detection results and increased the detection rate to 72% for changes to buildings.Remote SensingAerospace Engineerin

Accuracy assessment of airborne laser scanning strips using planar features

Airborne Laser Scanning (ALS) is widely used in many applications for its high measurement accuracy, fast acquisition capability, and large spatial coverage. Accuracy assessment of the ALS data usually relies on comparing corresponding tie elements, often points or lines, in the overlapping strips. This paper proposes a new approach to strip adjustment and quality assessment of ALS data by using planar features. In the proposed approach a transformation is estimated between two overlapping strips by minimizing the distance between points in one strip and their corresponding plane in the other. The planes and the corresponding points are extracted in a segmentation process. The point-to plane distances are used as observables in the estimation model, where the parameters of a transformation between two strips and their associated quality measures are estimated. We demonstrate the performance of the method on the AHN2 dataset over Zeeland province of The Netherlands. The dataset consists of 13 overlapping strips, from which a total of 522 gable roof and dike slope planes are extracted. The results show planimetric offsets between the strips that range from 3.13 cm to 55.32 cm. These offsets are in agreement with previously reported results using linear features. In addition, we estimated vertical offsets in the order of a few centimeters, which were not estimated in previous studies. The rotation parameters between the strips were also estimated; however, these did not show a significant difference in the orientation of the strips.Remote SensingAerospace Engineerin

Peritoneal dialysis in patients with heart failure

Both in dialysis patients and non-uremic patients heart failure is associated with an adverse prognosis. In a state of abrupt worsening of cardiac function, acute cardiogenic shock or decompensated congestive heart failure, acute kidney injury may occur, whereas in a more chronic worsening of cardiac function chronic kidney injury may occur. Recently, the term cardiorenal syndrome was adopted and defined as "a pathophysiological disorder of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ". Despite better treatment techniques and the continuous development of new medications volume overload in patients with cardiorenal syndrome is difficult to treat. Especially treatment of cardiorenal syndrome type I and II is notoriously difficult. Peritoneal dialysis might be, because of the gradual fluid removal, a therapeutic option in these patients. However, data on the effect of peritoneal dialysis in patients with heart failure with fluid overload and/or renal impairment are scarce. In this reviewe, the role of peritoneal dialysis in the treatment cardiorenal syndrome type I, II and IV will be discussed

Peritoneal dialysis in patients with heart failure

Both in dialysis patients and non-uremic patients heart failure is associated with an adverse prognosis. In a state of abrupt worsening of cardiac function, acute cardiogenic shock or decompensated congestive heart failure, acute kidney injury may occur, whereas in a more chronic worsening of cardiac function chronic kidney injury may occur. Recently, the term cardiorenal syndrome was adopted and defined as "a pathophysiological disorder of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ". Despite better treatment techniques and the continuous development of new medications volume overload in patients with cardiorenal syndrome is difficult to treat. Especially treatment of cardiorenal syndrome type I and II is notoriously difficult. Peritoneal dialysis might be, because of the gradual fluid removal, a therapeutic option in these patients. However, data on the effect of peritoneal dialysis in patients with heart failure with fluid overload and/or renal impairment are scarce. In this reviewe, the role of peritoneal dialysis in the treatment cardiorenal syndrome type I, II and IV will be discussed

Fluid State and Blood Pressure Control: No Differences Between APD and CAPD

The aim of this study was to compare fluid state, ambulatory blood pressure, and sodiumremoval in automated peritoneal dialysis (APD) and continuous ambulatory peritonealdialysis (CAPD). This observational, cross-sectional study comprised 20 APD and 24 CAPD patients with a mean duration on peritoneal dialysis of 30+/-26 and 21 +/-23 months, respectively. Sixty-four percent of the patients were treated with icodextrin. The methods used were 24 hr dialysate and urine collections, standardized 3.86% glucose peritoneal equilibration test (PET), bioimpedance analysis, and 24 hr ambulatory blood pressure monitoring. Extracellular water (ECW) corrected for body weight was 0.23 6 0.03 L/kg both in APD and CAPD patients. The slope normovolemia value according to Chamney was 0.0 6 0.2 L/kg in APD patients and 0.0 6 0.05 L/kg in CAPD patients (not significant [NS]). Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were respectively, 132 +/- 25 and 79 +/- 8 mm Hg in APD and 129 +/- 16 and 76 +/- 11 mm Hg in CAPD patients (NS). Sodium concentration in dialysate was respectively, 129.5 +/- 3.5 mmol/L in APD and 132.4 +/- 4.1 mmol/L in CAPD (p= 0.017). Dialysate sodium removal was 80.6 +/- 78.4 mmol/24 hr in APD and 108.7 +/- 96.8 mmol/24 hr in CAPD patients (NS). Natriuresis was respectively, in APD 76.6 +/- 65.5 mmol/24 hr and in CAPD 93.5 +/- 61.7 mmol/24 hr (NS). Total sodium removal was 149.5 +/- 76.6 mmol/24 hr in APD and 198.4 +/- 75.0 mmol/24 hr in CAPD (p= .039). Despite a higher daily sodium removal in CAPD patients, fluid state and blood pressure were not different between APD and CAPD. In general, volume status and blood pressure appeared to be reasonably controlled in this unselected population