Abstract

Automatic retinal image analysis is emerging as an important screening tool for early detection of eye diseases. Glaucoma is one of the most common causes of blindness. The manual examination of optic disk (OD) is a standard procedure used for detecting glaucoma. In this paper, we present an automatic OD parameterization technique based on segmented OD and cup regions obtained from monocular retinal images. A novel OD segmentation method is proposed which integrates the local image information around each point of interest in multidimensional feature space to provide robustness against variations found in and around the OD region. We also propose a novel cup segmentation method which is based on anatomical evidence such as vessel bends at the cup boundary, considered relevant by glaucoma experts. Bends in a vessel are robustly detected using a region of support concept, which automatically selects the right scale for analysis. A multi-stage strategy is employed to derive a reliable subset of vessel bends calledr-bends followed by a local spline fitting to derive the desired cup boundary. The method has been evaluated on 138 images comprising 33 normal and 105 glaucomatous images against three glaucoma experts. The obtained segmentation results show consistency in handling various geometric and photometric variations found across the dataset. The estimation error of the method or vertical cup-to-disk diameter ratio is 0.09/0.08 (mean/standard deviation) while for cup-to-disk area ratio it is 0.12/0.10. Overall,the obtained qualitative and quantitative results show effective-ness in both segmentation and subsequent OD parameterization for glaucoma assessment.

Abstract

Diabetic macular edema (DME) is an advanced symptom of diabetic retinopathy and can lead to irreversible vision loss. In this paper, a two-stage methodology for the detection and classification of DME severity from color fundus images is proposed. DME detection is carried out via a supervised learning approach using the normal fundus images. A feature extraction technique is introduced to capture the global characteristics of the fundus images and discriminate the normal from DME images. Disease severity is assessed using a rotational asymmetry metric by examining the symmetry of macular region. The performance of the proposed methodology and features are evaluated against several publicly available datasets. The detection performance has a sensitivity of 100% with specificity between 74% and 90%. Cases needing immediate referral are detected with a sensitivity of 100% and specificity of 97%. The severity classification accuracy is 81% for the moderate case and 100% for severe cases. These results establish the effectiveness of the proposed solution.

Abstract

This paper aims to simulate the Tsunami wave propagation in Indian Ocean. The simulation is done using OPENGL (Open Graphics Library) in Linux. The Analysis area covers from 8.15 degrees (-ve North) to 26 degrees (+ve north) and 71.72 degrees (+ve East) to 104.78 degrees (+ ve East). The Bathymetry data and Grid map are derived from GEBCO (General Bathy-metric Chart Of Oceans). The Bathymetric Grid Map is divided in the form of Grids. The Grid Map using OPENGL is scaled, transformed and displaced to get the depth value corresponding to the point which is assumed as epicentre.

Abstract

Earthquake performance of RC bare frame has been well documented in the past. Also, damage patterns in reinforced concrete frames during the past earthquakes have been extensively studied. However, more recently, several destructive earthquakes, including the 1999 Athens (Greece) earthquake, the 1999 İzmit and Düzce earthquakes (Turkey), 1999 Chi Chi (Taiwan) earthquake, 2001 Bhuj (India) earthquake, and the 2003 Boumerdes (Algeria) earthquake, have given more insights to performance of RC frame constructions. In order to understand the complete behavior of RC frame, it is required to study the performance from no loading condition till the complete collapse. In this paper, a set of four bare frames designed as per Indian Standards are considered. All the frames are subjected to Northridge earthquake ground motion. Newly developed numerical model called Applied Element Method (AEM) is considered for analysis. Initially, the linear analysis is carried out and the results were compared with commercially available software. Later, progressive collapse analysis is performed. Collapse process of each bare frame is discussed in detail.

Abstract

Water Reactors are nuclear power plants that use water to control and remove the heat from the nuclear fuel in order to convert heat to electricity. In this report, we have considered the number of nuclear reactors and their locations in our country. Among all those nuclear reactors, we selected the nearest kalpakkam reactor which is located in Chennai, India. All the faults, around 500 kms from the reactor are considered. From the past history of earthquake data (1812-2002), we considered the maximum magnitude of each fault and source parameters for some faults has been determined. The soil liquefaction characteristics of a site and the procedure for generating Synthetic accelerogram using the Stochastic Method Simulation of ground motion from earthquakes (SMSIM) have been discussed. For performance evaluation, a 3-dimensional model of the dome was taken and dynamic (Time History analysis) was performed to evaluate the displacements at each floors. A 3-dimensional model of the dome was modeled in computer program SAP2000 and Dynamic (time history) analysis was performed on the structure to evaluate the structure's response. The model was analyzed for the earthquake ground motion obtained from SMSIM.

Abstract

Every year in the country innumerable number of life and property is getting lost in the disasters. Pre-disaster planning i.e., mitigation and preparedness can have a good impact on minimizing the post-disaster response i.e., emergency, rescue and rehabilitation. This also reduces tragedy and suffering to a great extent. Andhra Pradesh being 4th largest state in India by area of 2,75,608 km² and 5th largest in population with over 100 million and a density of 277 persons/km2 is spread over 23 districts. Although it lies in the central part of peninsular Indian shield it has prone to many disasters which caused large number of casualties and innumerable property loss. This paper discusses the disasters like cyclone, floods, drought, earthquakes, tsunami, fire, etc., with statistics relevant to each disaster. Finally, we recommend the effecient strategies for disaster risk mitigation.

Abstract

In the past there were many terrorist attacks on buildings. Also the threat of such kind of attacks is increasing day-by-day. After the progressive collapse of the Roman Point apartment, England in 1968, structural engineering research departments throughout the world forced to direct their research towards the progressive collapse of highrise buildings under abnormal loads. Many guidelines, standards and criteria were developed across the world. Such guidelines are necessary for construction of blast resistant buildings. However, in addition to these guidelines, it is necessary to understand the progressive collapse process of the building under the action of heavy impact load. In this paper, we studied the linear responses of different RC bare frames for different ranges and charge weights according to different blast loads. Initially, the blast loads over the frames are calculated for for different ranges and charge weights according to TM 5-1300 9. Later these loads are applied on the bare frames taken from the structures which are designed for the normal gravity and lateral loads. Four fames (one story one bay, three story one bay, five story one bay and ten story-three bays) are considered. For the purpose of the study, highly efficient numerical model AEM is used. Results clearly show that the even though the charge weight of the blast is increasing the response is not increasing linearly. Also the response is low for heavy structures compared to lighter structures.

Abstract

Earthquake problems in India need no introduction. Some of the great earthquakes of the world occurred in India and neighbourhood areas. During past two decades, India has witnessed 7 moderate earthquakes which caused large number of casualties and innumerable property loss. Most of these losses are due to poor quality of construction and generally low level of awareness of the earthquake hazard prevalent in the country. In this regard, there is a need for coordinated and sustained effort towards earthquake risk reduction in the country. This can be achieved through education and awareness building. In general, sensitization programmes are required to build awareness at all levels, however, it is most important at school level because they prepare the future generations from early age. It is necessary to prepare simple reading material so that children can understand the problems at an early age itself. In this paper, we are discussing our effort in organizing earthquake day in 50 schools. Initially 50 schools in Hyderabad city were selected and on an average around 100 school children ranging from 8th to 10 standard were sensitized in each school. Total duration of the programme was 18 months. On school earthquake day, planned activities are as follows: Session I Introduction to earthquakes through animated short videos Session II Explanation of awareness generating experimental models Session III Explanation of information posters related to disaster preparedness Session IV Explanation of preparation of earthquake safety kits Session V Earthquake quiz and puzzle games related to disasters The models and material used for demonstration was given to school for their future use. Overall the programme was successful and we received excellent feedback from schools.

Abstract

During past earthquakes there were some notable instances of collapse of light houses near gujarat coast. These damages can be minimized by proper evaluation of seismic hazard based on past history of earthquakes in the region. During Bhuj, 26th Jan 2001 earthquake of magnitude 7.9Mw, some structures have damaged a lot while others have little, the behavior of light house during earthquakes depends critically on its overall shape, size and geometry in addition to how the earthquake forces are carried to the ground. In this regard, we attempted to check the earthquake response of light houses of different geometries. For this purpose we selected three different light houses of three different shapes (square, hexagon, octagonal) of same height. All the three light houses are modeled using SAP 2000 and dynamic analysis is performed. Each light is subjected to ten different earthquake ground motions and responses are compared

Abstract

The world today has encountered with global warming and climate change. Besides other contributors, extraction of natural resources as building materials itself consume energy, cause environmental degradation and contribute to global warming. Buildings are the largest energy consumers and greenhouse gases emitters, both in the developed and developing countries. Urgent changes are therefore required relating to energy saving, emissions control, production and application of materials. Immediate suggestion related to use of renewable resources, and to recycling and reuse of building materials is necessary. This paper describes how much a typical building is contributing to global warming by releasing the carbon dioxide emission. And how the architects and building designers can decrease the amount of carbon footprint emitted from the building materials. As a case study a 3-story building made of commonly used materials; concrete, brick, stone and glass has been selected. Total quantity of carbon emission is estimated and finally suggestions are given to reduce carbon dioxide emission.