Variation In Intensity Levels Research Articles

Segmentation of mammogram images using level set with Cuckoo search optimisation

ABSTRACT Breast cancer is alone accounted for 30% of all new cancer diagnoses for women. Early identification of breast cancer is a key stage in the process of diagnosis and treatment. Segmenting of low contrast mammograms is not an easy task due to irregular mass form, speculated margins and variation in intensity levels. Most of the region-based technique works well for homogenous images but fails for intensity inhomogeneity. Multiphase level set segmentation is optimised by the cuckoo search approach for energy minimisation. The proposed multiphase level set with the cuckoo optimisation method performs well in segmenting homogeneous as well as inhomogeneous regions. The Chan Vese (CV) and the proposed method are applied to the Mammographic Image Analysis Society (MIAS) database to obtain the accurate contour of the masses. To validate the proposed approach using quantitative performance measures such as Jaccard coefficient (JC), dice coefficient (DC), Hausdorff distance (Hd), sensitivity, specificity and accuracy were used for the MIAS data set. The results indicate that the suggested method can successfully segment the breast mass in mammograms and more robust than the classical CV method.

Drivers of changes in agricultural intensity in Europe

The global demand for agricultural products will increase in the 21st century, unless major transformations in consumptive behaviour occur. To a large extent, production increases in agriculture will depend on intensifying existing agricultural systems. Yet, our understanding of what determines the spatial patterns of agricultural intensity and changes therein is limited. Here, we analysed agricultural intensity changes in Europe focussing on yields and fertiliser application for six major crop-type groups for the period 1990–2007. We applied random effects panel regressions to analyse the spatial determinants of intensity changes using a suite of biophysical and socio-economic variables. We found that yields increased and mineral nitrogen application decreased by approximately 10%, suggesting a decoupling of changes in output and input intensity in Europe’s agricultural systems. Yields and nitrogen application across crop-type groups were particularly high in Western and Central Europe, whereas Eastern Europe was characterised by lower yields and nitrogen application. We also found strong sub-national variation in intensity levels in respect to crop-type groups and indicators. Higher yields were typically related to higher fertilisation, high soil quality, less growing degree days, and high labour productivity. Higher nitrogen application rates, in turn, were related to high soil water and carbon contents, and high labour productivity. Our study provides insights into broad-scale agricultural intensity patterns in Europe that allow for identifying trade-offs between agriculture and the environment, as well as entry points for regionalised, targeted policy making towards a more sustainable management of Europe land systems.

An Approach for Real Time Plastic Waste Segregation

Plastic has found an irreplaceable part in human life. Human produces plastic wastes continually which results in pollution. In this paper GLCM (Gray Level Co-occurrence Matrix) technique is used for plastic segregation. Plastic segregation is necessary for recycling; hence they have to be segregated from other wastes. Manufacturing plastics from recycled plastic products uses only two-third of the energy used to make plastics from virgin materials. By the variation in intensity levels of reflected light from the plastic wastes it is segregated. This type of waste management gains attention in recent days due to enormous increase in the wastes generated. Robotic arm controlled using vision system that uses GLCM technique is used for segregation. The GLCM property of contrast is calculated for the given sample and it is compared with the stored pre-defined value. On successful comparison with the given condition a signal is sent through the serial port to the 8051 microcontroller using USART (Universal Synchronous/Asynchronous Receiver/Transmitter) feature. On receipt of this signal, the microcontroller provides movement of the robotic arm by controlling the servo motors.

Energy Expenditure and Intensity Levels During a 6170-m Summit in the Karakoram Mountains

Although the majority of high altitude studies have used doubly labeled water to assess energy expenditure (EE), minimal research has examined variation in intensity levels while participating in such an expedition. The purpose of this study was to use ambulatory monitoring technology to assess EE and time spent in moderate (3.0-6.0 METS), vigorous (6.0-9.0 METS), and very vigorous (>9.0 METS) intensities during an expedition to summit a 6170-m peak in Northern Pakistan. Twelve men and 2 women were studied. Their EE was determined from galvanic skin response, heat flux, and biaxial accelerometry using a multisensor armband. Lake Louise Scores for altitude illness assessment were obtained each morning. Average daily total EE and number of steps taken was 4173 ± 848 kcal/d (range, 3332 to 4838 kcal/d) and 26,232 ± 7210 steps/d (range, 11,788 to 34,979 steps/d), respectively. On average, subjects spent approximately 7.7 h/d performing physical activity (>3.0 METS). Of this, subjects spent 399 ± 107, 61 ± 77, and 3 ± 10 min/d at moderate, vigorous, and very vigorous intensity levels, respectively, corresponding to 88%, 11%, and 1% of total physical activity time. During summit day, subjects climbed at an intensity equivalent to approximately 42% of their high altitude predicted maximal oxygen consumption at 5100 m). During a high altitude expedition, subjects predominantly exercise at a moderate intensity, with limited time spent at higher intensity levels. Use of accelerometer-based technology may provide more cost-effective and logistically easier means of assessing EE in extreme environments.

Edge‐detection of the radiation field in double exposure portal images using a curve propagation algorithm

An accurate detection of the radiation field is crucial to 3D conformal radiotherapy (3D‐CRT). Automated techniques to detect the field edges on double exposure portal images have previously focused on thresholding techniques. In this paper, we present a new approach based on a curve propagation technique (the Fast Marching method) which proves to be more effective at detecting the radiation field than its thresholding counterpart. The comparison of both techniques in terms of computational speed and effectiveness of the detection is presented using complex images with non‐homogeneous intensity levels inside the radiation field, and gradual variations in intensity level at the field boundaries. Results show that our Fast Marching method is easier to automate, and converges faster to the boundaries of the segmented radiation field. The computation time of the Fast Marching technique is five times faster in typical portal images.PACS numbers: 87.53.Oq, 87.57.Nk, 87.57.‐s.

Determinants of Agricultural Intensity Index “Scores” in a Frontier Region: An Analysis of Data from Northern Guatemala

Data on farming systems in Peten, Guatemala, were used to develop an agricultural intensity index. The index can be used to assign an intensity “score” to a given farming system based on the array of practices used by the farmer, each practice’s contribution to production intensity, and the scale at which these practices are used. The scores assigned to 118 farmers in three study areas in Peten were analyzed through analysis of variance (ANOVA) to identify the factors that account for the variation in intensity levels, as measured through the index. The analyses reveal that the factors influencing agricultural intensity in Peten vary greatly from one study area to the next. This is due to differences in livelihood opportunities and strategies that, in turn, affect how agriculture fits into the local economy and how and why intensification is pursued. Variation in intensity levels can best be understood by considering the factors at the household and sub-regional scales that influence (a) whether farmers feel a need to intensify, (b) whether they see some benefit in doing so, and (c) whether they have the resources required to intensify production through particular strategies. Close attention must be paid to these factors by conservation and development organizations seeking to influence land use patterns and conserve forest in Peten.