Abstract

A switching converter (dc-dc) cascaded with parallel low-dropout (LDO) regulators gives the best tradeoff in terms of high system efficiency and low output ripple for automotive power management ICs (PMICs). The minimum dc-dc output voltage is dependent on the highest LDO output and its corresponding dropout voltage. An adaptive LDO dropout technique based on maximum load current selector circuit has been proposed to improve the moderate and light load system efficiency of the hybrid PMIC with dc-dc supplying three independent LDO regulators. The circuit has been fabricated in AMS 0.35-μm high-voltage CMOS process and tested across wide supply voltage of 6-18 V, wide temperature range of -40 °C to 150 °C, and maximum load of 450 mA to meet the harsh automotive application requirements. The adaptive dropout circuit has minimal overhead (<;2%) in terms of area compared to fixed dropout architectures and negligible current consumption overhead. The overall system efficiency improvement of about 3%-10% is achieved with adaptive dropout scheme as per the experimental results. The concept is independent of dc-dc and LDO architecture and can be extended to many system-on-a-chip-based power supplies with dc-dc and LDO combination.

Abstract

Cognitive radio offers a novel solution to over-come the problem of spectrum underutilization by providing spectral access to secondary users. The television (TV) bands are of particular interest for secondary usage due to their high penetration power and greater coverage. These licensed bands are occupied only in few regions while in most of the other regions they are unoccupied and are termed asTV white space(TVWS). The estimation of TVWS has mostly been done by usingthe statistical and empirical propagation models. In this paper,terrain data is incorporated into the estimation of TVWS and shown to improve the quantitative estimation of TVWS. Using the relevant transmitter information and terrain data in the Indian state of Telangana, the efficacy of the proposed approach is demonstrated. The performance of the proposed approach is compared to that of widely used H at a propagation model. It is shown that the accuracy in TV coverage estimation increases onan average by 45% while incorporating terrain data as compared to using only empirical propagation model. As area outside theTV coverage is TVWS, the increased accuracy in the estimation of TV coverage directly translates to improved accuracy in the estimation of TVWS, which in turn translates into more efficient use of spectrum and better interference management

Abstract

Unplanned large scale developmental projects in recent times have been causing alterations in land use land cover [LULC] at spatial and temporal scales with the substantial changes in the landscape. Uttara Kannada district has the distinction of having highest forest cover in India.Forest ecosystems in the district have witnessed major transformations due to industrialization during the post-independence. Impact of developmental activities during the post-independence era, is evident from barren hill tops due to deforestation. The analysis of temporal spatial data acquired through space borne sensors highlights the decline of evergreen-semi evergreen forest cover from 67.73% (1973) to 32.08% (2013). The ad-hoc approaches adopted in the implementation of developmental projects in the ecologically sensitive regions has impaired the ecosystem services affecting the people’s livelihood. The changes in the landscape structure with LULC changes have altered the functional abilities of an ecosystem evident from lowered hydrological yield, disappearing perennial streams, higher instances of human–animal conflicts, declined ecosystem goods, etc. About 64355 Ha of forest land is diverted for various non-forestry activities during the last four decades by the government apart from encroachment of 7072 Ha of forest area for agriculture, horticulture activities, etc. Encroachment of forest land has resulted in the land degradation leading to reduce dproductivity. Alterations in bio-geo chemical and hydrological cycles have necessitated the restoration of native forests in the region to ensure water and food security, and livelihood of the local people. Monitoring and visualization of landscape dynamics helps in evolving appropriate manage-ment strategies. LULC dynamics analyses considering agents (developmental projects) through fuzzy analytic hierarchy process (AHP) integrated with Markov cellular automata (CA) indicate the developmental projects such as West Coast Paper Mill (WCPM) and Kaiga Nuclear PowerHouse (KNPH) will lead to further fragmentation of forests with spurt in urbanization by 2022.This necessitates framing appropriate policy measures to sustain natural resources focusing on the landscape’s ecological, hydrological, economic and social factors.

Abstract

This paper describes a software system for automatically generating a reference (baseline) building energy model from the proposed (as-designed) building energy model. This system is built using the OpenStudio Software Development Kit (SDK) and is designed to operate on building energy models in the OpenStudio file format.

Abstract

The radiant systems consume less energy and provide better thermal comfort as compared to the Conventional system, but the main drawback of this technology is condensation and inability to cater the latent load. These challenges have directed many researchers to move their emphasis towards Personalized Conditioning System which aims to generate a microclimate zone near the vicinity of occupant according to need. This study is focused on Personalized Conditioning System when it is combined with a radiant system. The objectives of this study are 1) Evaluate the performance analysis of the system in cooling mode and, 2) Evaluate the performance of PRCS for cooling mode on different radiant cooling systems. An experimental setup of an office cubicle has been designed and fabricated using radiant panels at MNIT Jaipur, India. Three cases of the experiment were designed to evaluate and compare the performance of the system which are: Only Radiant Cooled Ceiling System (RCCS), Only Personalized Radiant Cooling System (PRCS), and both PRCS and RCCS coupled. It was observed that PRCS alone is sufficient to reach the thermal comfort criteria with low energy consumption, but it was unable to maintain the background temperature. When PRCS coupled with RCCS, it gives maximum thermal comfort for high supply water temperature ranging from 17 °C to 21 °C.

Abstract

Pervasive large scale land cover land use (LULC) changes leading to deforestation have enhanced concentrations of carbon dioxide in the atmosphere and significantly impacted the regional water cycle and bio-geo chemical cycles. This neceissates assessment of current level of transitions and likely future transitions for an effective decision making towards sustainable management of natural resources. Karwar taluk of Central Western Ghats has been experiencing rapid landscape changes due to unplanned developmental activities and the consequences were evident form frequent occurrence of landslides with the loss of life and property. Analysis of land cover transitions based on temporal spatial data helps more efficient land management policies. The present study aims to visualize and forecast forest land status (2000-2026) by exploring the effects of various factors such as protected areas, slope, waterbodies, proximity to roads, industries and urban centers through agent based model on land use change. The land use change inducing factors are normalized and relative weights were generated through fuzzyfication and Multi criteria Evaluation (MCE). The spatial patterns were quantified using metrics such as Number of Patches (NP), the Edge Density (ED) and Area-Weighted Mean Patch Fractal Dimension (AWMPFD). The forest cover has reduced from 73.59 % (2000) to 67.32% (2016) with an increase in built-up from 3.17 (2000) to 8.65% (2016). Forest cover in 2024 would be about 60.44% with increase in built-up area 14.79%. Unplanned developmental activities with the increasing trends of urbanisation are the prime reasons for disasters such as landslides, water scarcity, etc. The technique has provided insights to unsustainable land cover transitions in the region for an integrated and holistic path of development to sustain natural resources while mitigating human made disasters.

Abstract

etties are one of the most important structures in the coastal area, which can be used for transporting large quantities of goods and raw materials from one place to the other. Their functionality is very much essential because they are lifeline structures of the country. It is observed during the past earthquakes that jetties have been damaged even under mild shaking. Damaged and unserviceable jetties cause delay of export and import business. It directly affects the economy of particular region in terms of business, employment and growth. This clearly indicates the need to design these facilities so that they can withstand natural disasters particularly earthquakes and tsunamis. In this paper, a study has been carried out to find out the damage (D) to the Jetty. The Jetty is modeled using 2D Applied Element Method (AEM) to perform damage analysis of structure. Pushover analysis is done to get base shear vs roof displacement of building using displacement control method. Using the dissipated energy approach, damage is quantified at every displacement level and normalized to 1. A fragility curve has been developed to quantify the damage of Jetty with respect to different peak ground accelerations. The damage values were calculated for the PGA values of KHF Mandvi, NKF Jodiya and KMF Jhangi and found that the Jetty got light damage (D= 0.2), and moderate damage (D= 0.38 and 0.42) respectively.

Abstract

Drastic land use land cover changes (LULC) in forest landscape alters the functional ability of forest ecosystem, evident from decline in quantity and duration of water flow in streams, loss of carbon sequestration potential, etc. affecting the local livelihood, while inducing changes in the climate. This necessitates inventorying, mapping and monitoring of LULC dynamics to evolve appropriate location specific mitigation strategies. The LULC dynamics can be assessed effectively through free and open source software using temporal remote sensing data and modeling and forecasting techniques. The current research work aims to identify spatio-temporal land use changes from 2007-2016 in Kaiga Nuclear Power house (NPH) and its environs with the help of GRASS GIS (a robust free and open source software). Land uses in 2022 is predicted through Cellular Automata–Markov Chain model with the knowledge of land use transitions during the four decades. Validation of the model is done using Kappa indices, which shows good accuracy due to agreement of the predicated and actual land uses. The region has lost forest cover from 23 to 16.81 % (2016-2022) with an increase of built-up are of 42.01 to 46.81 % (2016-2022). The land use modeling, planning and policy by implying ecological science perspectives can improve understanding of ecological processes. The recent study reports of higher instances of cancer in humans with the functioning of NPH during the last decade. Any further expansion of NPH area would have serious ecological implications due to loss of vast tracts of forests, farmlands and would threaten the health and livelihood of local population.

Abstract

Earthquake resistant design of structures requires the knowledge of quantified seismic hazard. To quantify the seismic hazard, Peak Ground Acceleration (PGA) is used for design procedures. The maximum possible PGA of a particular region depends on seismic parameters like magnitude, hypocentral distance, type of soil etc. Though it can be obtained by observing the past seismic events, it is more realistic to relate it with the parameters that influence it. Due to high seismic activity at the Himalayan region, this paper is aimed at developing a Ground Motion Prediction Equation (GMPE) for this region. For this purpose, two sets of 168 earthquakes (2.5-7.2 Mw) have been selected that are recorded at different stations within 500 km radius along the Himalayan belt. A statistical analysis is carried out on both sets separately based on the relation of PGA with magnitude, hypocentral distance and the type of soil. New GMPE equations have been proposed. The same are compared with the existing GMPE for the same region and seismically similar regions.

Abstract

Experiences from past earthquake disasters clearly shows that the ground motion was responsible for majority of property and life loss. Among the collapsed structures during the 1964 Niigata earthquake, the 1995 Kobe earthquake, the 1999 Koceli earthquake, the 2001 Bhuj earthquake and the 2004 Sumatra earthquake, excessive damage was occurred to pile supported bridges, towers, chimneys, high rise structures, etc. In view of this, there is a need to study the complex behaviour of soil-pile-structure interaction problems. In this research paper, a numerical study is carried out to understand the dynamic soil Foundation structure interaction (SFSI) of a framed structure supported on a pile foundation. For that purpose a 5 storey pile supported framed structure is modeled and the behaviour under strong earthquake excitations associated with nonlinear material behaviour is studied. A peculiar behaviour in the stress state of pile in the SFSI system is observed. This behaviour is because of Soil resistance acting downward along the pile shaft because of an applied transient load. Also, the comparison of linear and nonlinear stress states and the effect/significance of soil plasticity on the stress states are commented.