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Journal Articles | 2021

A deep-learning-based image forgery detection framework for controlling the spread of misinformation

Ambica Ghai and Pradeep Kumar Samrat Gupta

Information Technology & People

Purpose – Web users rely heavily on online content make decisions without assessing the veracity of the content. The online content comprising text, image, video or audio may be tampered with to influence public opinion. Since the consumers of online information (misinformation) tend to trust the content when the image(s) supplement the text, image manipulation software is increasingly being used to forge the images. To address the crucial problem of image manipulation, this study focusses on developing a deep-learning-based image forgery detection framework.

Design/methodology/approach – The proposed deep-learning-based framework aims to detect images forged using copy-move and splicing techniques. The image transformation technique aids the identification of relevant features for the network to train effectively. After that, the pre-trained customized convolutional neural network is used to train on the public benchmark datasets, and the performance is evaluated on the test dataset using various parameters.

Findings – The comparative analysis of image transformation techniques and experiments conducted on benchmark datasets from a variety of socio-cultural domains establishes the effectiveness and viability of the proposed framework. These findings affirm the potential applicability of proposed framework in real-time image forgery detection.

Research limitations/implications – This study bears implications for several important aspects of research on image forgery detection. First this research adds to recent discussion on feature extraction and learning for image forgery detection. While prior research on image forgery detection, hand-crafted the features, the proposed solution contributes to stream of literature that automatically learns the features and classify the images. Second, this research contributes to ongoing effort in curtailing the spread of misinformation using images. The extant literature on spread of misinformation has prominently focussed on textual data shared over social media platforms. The study addresses the call for greater emphasis on the development of robust image transformation techniques.

Practical implications – This study carries important practical implications for various domains such as forensic sciences, media and journalism where image data is increasingly being used to make inferences. The integration of image forgery detection tools can be helpful in determining the credibility of the article or post before it is shared over the Internet. The content shared over the Internet by the users has become an important component of news reporting. The framework proposed in this paper can be further extended and trained on more annotated realworld data so as to function as a tool for fact-checkers.

Social implications – In the current scenario wherein most of the image forgery detection studies attempt to assess whether the image is real or forged in an offline mode, it is crucial to identify any trending or potential forged image as early as possible. By learning from historical data, the proposed framework can aid in early prediction of forged images to detect the newly emerging forged images even before they occur. In summary, the proposed framework has a potential to mitigate physical spreading and psychological impact of forged images on social media.

Originality/value – This study focusses on copy-move and splicing techniques while integrating transfer learning concepts to classify forged images with high accuracy. The synergistic use of hitherto little explored image transformation techniques and customized convolutional neural network helps design a robust image forgery detection framework. Experiments and findings establish that the proposed framework accurately classifies forged images, thus mitigating the negative socio-cultural spread of misinformation.

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Journal Articles | 2021

New valid inequalities for the symmetric vehicle routing problem with simultaneous pickup and deliveries

Yogesh Kumar Agarwal and Prahalad Venkateshan

Networks

The symmetric vehicle routing problem with simultaneous pickup and deliveries is considered. The current state-of-the-art method to solve this problem employs the idea of a no-good cut. This article achieves an order of magnitude improvement in the computational time needed to solve difficult problem instances by generalizing the no-good cuts and developing a way to generate improved no-good cuts much earlier in a branch-and-bound tree. Results are reported on benchmark instances in literature and new difficult instances generated by the authors. Some polyhedral results are presented about the strength of the generalized no-good cuts for a special case of the problem.

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Journal Articles | 2021

Entry timing as a mixed gamble in cross-border acquisition waves: A study of family firms

Mohammad Fuad, Vinod Thakur, and Ashutosh Kumar Sinha

Family Business Review

We draw upon the mixed gamble perspective to investigate the entry timing decisions made by family firms in the context of cross-border acquisition (CBA) waves. We argue that family-controlled firms trade-off short-term SEW and financial losses in favor of long-term SEW and financial gains, while moving early in CBA waves. Findings suggest that family-controlled firms have a higher preference for early movement compared with nonfamily-controlled firms. Further, we show that founder’s presence on the board and acquirer’s superior performance amplifies the mixed gamble trade-offs, thereby strengthening the relationship between family control and early movement within CBA waves.

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Journal Articles | 2021

Understanding temperature related health risk in context of urban land use changes

Vidhee Avashia, Amit Garg, and Hem Dholakia

Landscape and Urban Planning

A city’s climate is affected both by global warming and the local factors such as built form and the landscape. The temperature related impacts of climate change make urban areas more vulnerable particularly due to higher population concentration as well as heat island effect. Cities in India are already experiencing enhanced temperature and precipitation related impacts of climate change and extreme events, e.g., >2 °C warming in some places. This study describes a case of Ahmedabad – a city of around 5 million people (Census, 2011) and currently almost 7.8 million, located in the hot and humid western part of India to understand the current temperature-related mortality impacts and the role of land use. Satellite images (MODIS from NASA), temperature data from India Meteorological Department (IMD) and daily all-cause mortality from Ahmedabad Municipal Corporation between 2001 and 2015 have been used to create a distributed lag non-linear model. Using land surface temperature for mortality risk assessment gives significantly different results as compared to using air temperature for mortality risk assessment. This indicates impacts of localized temperature variations on mortality risks. Thus, the microclimate in a city as represented by land surface temperatures is a better indicator for estimating relative risk of temperature related mortality as compared to air temperature. The study also infers that with increase in built-up spaces by 1% in the land use mix, the relative risk of heat related mortality increases by 0.59 points at 40 °C and by 0.78 points at 45 °C.

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Journal Articles | 2021

Quantifying the local cooling effects of urban green spaces: Evidence from Bengaluru, India

Arpit Shah, Amit Garg, and Vimal Mishra

Landscape and Urban Planning

Rapid unplanned urbanization has led to a deterioration in green cover in Indian cities and an increase in urban temperatures due to the urban heat island (UHI) effect. With India’s urban population set to double from 400 million in 2011 to 800 million by 2050, it becomes critical to understand the role of urban green spaces (UGS) in mitigating the UHI. In this study, we have used high-resolution Landsat and Google Earth data and integrated it with spatial statistical analysis to quantify the cooling effects provided by UGS beyond their boundaries. We analyzed cooling effects at the level of individual UGS for 262 UGS in the megacity of Bengaluru, India. Our results showed that the average UGS provided local cooling effects till points 347 m (95% CI: 318 m to 376 m) beyond its boundary. The average UGS was 2.23 °C (95% CI: 2.13 °C to 2.33 °C) cooler than the point where it ceased to provide cooling effects. Cooling effects reduced with distance from the UGS, and were impacted by the greenness, size, and shape of the UGS. The findings of this study are important in the context of India’s Smart Cities Mission that has been criticized for an inadequate focus on urban greening. Our study addresses a concern that most previous studies have used a small sample of UGS for their analysis. To the best of our knowledge, this is the first study to quantify the role of UGS in localized surface temperature reduction for a large Indian city.

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Journal Articles | 2021

SDG implications of water-energy systems transitions in India under NDC, 2 °c and well below 2 °c

Saritha S. Vishwanathan, Amit Garg, Vineet Tiwari, Manmohan Kapshe, and Tirthankar Nag

Environmental Research Letters

India needs to address the immediate concerns of water supply and demand, due to its increasing population, rapid urbanization, and growing industrialization. Additionally, the changing climate will influence water resources, which will subsequently impact the overall sectoral end-use demand patterns. In this study, we have integrated a water module with the existing bottom-up, techno-economic Asia–Pacific Integrated Model/End-use energy system model for India to estimate the future water demand in major end-use sectors under business-as-usual (BAU), nationally determined contribution (NDC), and low-carbon futures (2 °C and 'well below 2 °C') up to 2050. We also simulate the effects of water constraints on major sectors under different climate-change regimes. Our results show that water-intensive end-use sectors, specifically agriculture and power, will face major impacts under water-constrained scenarios. Over the period between 2020 and 2050, policy measures taken under the NDC scenario can cumulatively save up to 146billion cubic metres (bcm) of water, while low-carbon scenarios can save 20–21 bcm of water between 2020 and 2050, compared with BAU. In a water-constrained future, NDC and low-carbon futures can save 28–30 bcm of water. There is a need to increase the current water supply by 200–400 bcm. The marginal cost of installing dry cooling systems in the power sector is considerably higher than the cost and benefits of installing micro-irrigation systems with solar PV. Integrated policy coherence is required to achieve sustainable development goals, e.g., NDC and Paris Agreement goals, in both water and energy sectors. Concurrently, regulatory and economic instruments will play an essential role in improving resource-use efficiency at a systemic level, to reduce the overall water demand.

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Journal Articles | 2021

Rational repricing of risk during COVID-19: Evidence from Indian single stock options market

Sobhesh Kumar Agarwalla, Jayanth R. Varma, and Vineet Virmani

Journal of Futures Markets

Could the COVID-19 related market crash and subsequent rebound be explained as a rational response to evolving conditions? Our results using multiple forward-looking measures of uncertainty implied from stock option prices suggest so. First, we find a gradual build-up of volatility during the month preceding the spike at the start of the pandemic. Second, while tail risk declined after government interventions, the level of uncertainty remained elevated for stocks across industries. Third, the dynamics of decline in tail risk in stocks was industry-dependent, suggesting that the market performed a fine-grained analysis of each stock's uncertainty through the pandemic.

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Journal Articles | 2021

How global marketing can be more global and more marketing: A bottom-up perspective from subsistence marketplaces

Madhubalan Viswanathan and Arun Sreekumar

Journal of Global Marketing

Our journey to subsistence marketplaces has been global in scope and resonates with marketing in beginning at the micro-level with a bottom-up orientation in understanding consumers, communities, and the larger context. This space offers an opportunity for us to discuss the broader lessons learned from this journey for global marketing.

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Journal Articles | 2021

Central bank gold reserves and sovereign credit risk

Sawan Rathi, Sanket Mohapatra, and Arvind Sahay

Finance Research Letters

Gold holdings with central banks are often considered to play a stabilizing role in times of crisis. This paper performs a cross-country panel data analysis of developed and developing countries to determine whether gold holdings of central banks contribute to sovereign creditworthiness. Our analysis confirms that an increase in central bank gold reserves reduces the credit default swap (CDS) spreads of a country. We also observe that during global crisis and country-specific crisis episodes, the role of central bank gold becomes even more important. In robustness tests, we account for potential endogeneity of central bank gold reserves using a Generalized Method of Moments (GMM) approach. The findings highlight the importance of gold in central bank reserves and indicate a positive role of gold in mitigating a nations external vulnerabilities in an uncertain global economic environment.

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Journal Articles | 2021

The implications of economic uncertainty for bank loan portfolios

Sanket Mohapatra and Siddharth M. Purohit

Applied Economics

This paper analyses the impact of economic uncertainty on the composition of bank credit across household and firm loans. Using bank-level data spanning 40 developed and developing countries, we find that higher economic uncertainty is associated with an increase in the relative share of household credit in the loan portfolio of banks. This change in composition of credit may result from banks efforts to reduce the overall riskiness of their loan portfolios, since corporate loans are generally viewed as riskier than household loans. This shift is more pronounced for weakly-capitalized banks, which may face greater risks during economic shocks, and for larger banks, which may be riskier due to complex business models and more market-based activities. The variation in our main findings by banks capitalization and size suggests that they arise from changes in bank credit supply in response to greater uncertainty. The baseline results hold for a range of robustness tests. Our study highlights the role of aggregate uncertainty in micro-level outcomes and are relevant for bank capital regulation and the conduct of macroprudential policy.

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