Abstract

Estimating the time, location and the size of an earthquake event using neural networks is an emerging technology. Present study aims to predict the near future earthquake events in each of the regions partitioned as clusters of epi-central locations of earthquakes related to Indian subcontinent. K-means clustering algorithm is applied to develop a catalogue of earthquake epicenters. Two approaches are considered for the purpose of forecasting. In the first approach regions obtained as clusters are considered as the area sources. The distribution of time series of (temporal distribution) events are divided into five time periods viz., 15 days, 30 days, 60 days, 90 days and 180 days. The accuracy of forecasting a magnitude for the next time period is studied using application of Recurrent Neural Network In the second approach the seismic data of each cluster is further grouped into three categories of magnitude viz., minor (≤ 4 Mw), moderate (between 4 Mw and 6 Mw) and strong (> 6 Mw). Accuracy of forecasting for each of the group belonging to the clusters is computed considering the same five time periods. The epicentral locations represented as latitude and longitude is the inputs for recurrent neural network. The results show that accuracy of second approach is significantly more than first approach. Finally, an attempt has been made to compare the accuracy level of Recurrent Neural Network method with the accuracy level of Gutenberg Richter law in predicting the earthquakes for future 60 days. It has been observed that Gutenberg-Richter law poorly forecasts near future earthquake. Keywords: Recurrent Neural Network; Earthquake forecasting, Clustering

Abstract

Open ground storey buildings are quite popular in India due to availability of parking space and high commercial value of the land. However, these open ground storey buildings become first victims during earthquake ground shaking. The same is evident from the collapse and huge damage in ground story columns during past earthquake events. This led to a huge loss of life and property. Hence, there is an urgent need to take up retrofit activities of open ground storey buildings. There were some instances where retrofit activities were taken up on open ground story buildings. However, the performance of the building was not tested after ground storey retrofit. To build confidence among the general public, there is a need to demonstrate that the retrofitted buildings not only save lives but also resist earthquake with minimum damage. This paper is an attempt to demonstrate the same. In this paper, a case study of G+5 open ground storey building has been taken and nonlinear static pushover analysis (POA) is performed to obtain capacity curve. Later, the building is retrofitted in its ground/first storey and again capacity curve is obtained using the POA. It is found that the performance of the building significantly improved. However, from the hinge formation pattern, it is observed that the damage has propagated to the second storey. To improve the performance further, the second storey is also retrofitted and POA is performed again. Further, as per the damage propagation to upper stories, retrofitting is done to respective stories. It is found from the hinge pattern and capacity curves that in retrofitted buildings, capacity increased up to a certain storey and after that no increment in capacity was observed. It is concluded from the study that retrofitting of open ground storey building does not mean retrofitting of only ground storey but all such columns/stories where damage is getting distributed after the retrofit of open ground storey.

Abstract

Dams are extremely important lifelines of a country. They aid in the growth of the economy. The large-scale devastation due to an earthquake can generate irreversible losses. 2% of the dam failures all around the world take place due to earthquakes. Earthquakes not only cause immediate damage but are also capable of weakening the structure by decreasing its resistance against further damages. In this work, we study the effect of strong ground motion earthquakes on concrete gravity dams. The strong ground motions lying within shallow depths are felt powerfully by the dams, since the high frequency waves are not filtered. This causes more damage to the dam as there is a high probability of resonance in higher modes, a result of the high frequency content in the ground motion. 5 strong ground motions in the Indian Subcontinent have been selected and applied on the Koyna dam which was constructed in the year 1963. 2D analysis of the dam has been performed in standard software. Qualitative analysis of dams shows that there are 3 regions which are most susceptible to damage within a dam cross-section i.e., neck, body and the heel of the dam. In this paper, the displacement of crest and the formation of tensile stresses at the 3 zones - neck, body, heel of the dam due to these 5 strong ground motions is analyzed. The point of highest tensile stress is most susceptible to damage and failure in the face of an earthquake. When the structure is exposed to the ground motions, under normalized peak ground accelerations (PGAs), the structure behaves differently based on the effect of the frequency content of the input signal. By Normalizing the PGA of the ground motion, we grasp an idea of the effect of frequency content on the dam structure. Keywords: Gravity dam; Stress analysis; Qualitative failure analysis; Frequency Content; Deterministic Analysis

Abstract

With the advent of intelligent transport, quadrotors are becoming an attractive aerial transport solution during emergency evacuations, construction works etc. During such operations, dynamic variations in (possibly unknown) payload and unknown external disturbances cause considerable control challenges for path tracking algorithms. In fact, the statedependent nature of the resulting uncertainties makes stateof-the-art adaptive control solutions ineffective against such uncertainties that can be completely unknown and possibly unbounded a priori. This paper, to the best of the knowledge of the authors, proposes the first adaptive control solution for quadrotors, which does not require any a priori knowledge of the parameters of quadrotor dynamics as well as of external disturbances. The stability of the closed-loop system is studied analytically via Lyapunov theory and the effectiveness of the proposed solution is verified on a realistic simulator.

Abstract

In India due to rapid economic development and establishment of new companies, many existing buildings were given permissions to raise the number of floors. This addition of new floors to the existing building will increase the loads on the columns which may not be designed for the additional load. Therefore, such columns need to be strengthened to carry the additional loads. RC jacketing is the most preferred strengthening technique to increase the load carrying capacity of the existing building. In this paper, comparison of two RC buildings i.e., One with columns strengthened only on 2 faces and another with columns strengthened on all four sides with RC jacketing is presented. In 2-face RC jacketing, U shape stirrups are used and for 4-face jacketing closed stirrups are used. Behavior of columns strengthened on all four sides using RC jacketing is more satisfactory in the case of immediate occupancy. In case of high seismic zones under cyclic loading, the seismic performance of RC jacketed columns on 2 sides is not desirable for immediate occupancy.

Abstract

Buildings on hill slopes are highly vulnerable due to its less resistive lateral load capacity. This type of buildings are unsymmetrical and are of in irregular configuration. There are variations in the column height which gives eccentricity to the structure as the center of mass and center of rigidity doesn’t coincide. This irregularity leads to its torsional behavior and gives us the necessity for analyzing these buildings for its base conditions and its behavior by changing its plan configuration. This paper contain the calculation of Twist which is an effective parameter to decide the behavior of the building, Axial forces on the members that can lead to collapse in the structure and about the twist variation with change in the aspect ratio so that we can know the suitability of the configuration of the building. The building on hill slopes does not behave similar to the buildings which are on plane ground. Change in the Aspect ratio means changing the length of the building in ridge direction. Changing the length in valley direction will disturb the load path of gravity load for each and every change in the structure and after some increment of the length in valley direction will fail the structure for its gravity load path. So we can’t play with the length of the building along the valley direction but changing the length along ridge direction does not effect that much to the load path of gravity load and we can obtain a best aspect ratio of the structure for that region. Keywords: Twist, Axial forces, Slope of the ground

Abstract

Residensial Energy electricity

Abstract

A corpus of Hindi news headlines shared on Twitter was created by collecting tweets of 5 mainstream Hindi news sources for a period of 4 months. 7 independent annotators were recruited to mark the 20 most retweeted news posts by each of the 5 news sources on its clickbait nature. The clickbait score hence generated was assessed for its correlation with interactions on the platform (retweets, favorites, reader replies), tweet word count, and normalized POS (part-of-speech) tag counts in tweets. A positive correlation was observed between readers’ interactions with tweets and tweets’ clickbait score. Significant correlations were also observed for POS tag counts and clickbait score. The prevalence of clickbait in mainstream Hindi news media was found to be similar to its prevalence in English news media. We hope that our observations would provide a platform for discussions on clickbait in mainstream Hindi news media.

Abstract

In this endeavour, a new adaptive-robust control framework is devised for tracking control problem of a class of uncertain systems having state-dependent uncertainty and under the influence of time-varying input delay. In comparison to the existing adaptive-robust control (ARC) strategies, the proposed ARC framework removes the conservative assumption of a priori bounded uncertainty. In addition, the Razumikhin theorem based stability analysis allows the proposed scheme to deal with arbitrary variation in input delay. The effectiveness of the proposed ARC is verified via simulations and via experimentations using a wheeled mobile robot demonstrating improved tracking accuracy compared to the state of the art. Keywords: Adaptive-robust control, Input delay, Razumikhin theorem, State-dependent uncertainty, Wheeled mobile robot

Abstract

Buildings damaged in past earthquakes have exemplified the poor performance of reinforced concrete moment resisting frame (RC MRF) buildings due to inadequate design and wrong construction practices. The only way to avoid damage to existing buildings is to retrofit them. There is a large stock of RC MRF buildings constructed as per old Indian standards. With the latest revisions in codal provisions, these buildings are considered to be inadequately designed. Therefore, a large stock of existing buildings needs to be retrofitted. However, retrofitting of houses is not a common practice among the general public in India. To encourage retrofitting among the general public, the efficacy of retrofitting needs to be proven with the well-laid process. In this paper, a case study is done to understand the performance of G+5 storey RC MRF precode building after partial and full column retrofitting. Pushover Analysis (POA) is performed to obtain the capacity of the precode building. The capacity is compared with the seismic demand of that area to decide whether retrofitting is required or not. Initially, ground storey columns are retrofitted and POA is performed to study the damage distribution and obtain the updated capacity curve. It is observed that damage shifted to the first storey. Further, the first storey columns are retrofitted and POA is performed again. From the hinge mechanism, it is observed that the damage propagated to the second storey. Further, the second storey columns are retrofitted and POA is performed again to obtain updated capacity and