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3819 items in total found

Journal Articles | 2019

Bridging the gap between probabilistic and fuzzy entropy

Manish Aggarwal

IEEE Transactions on Fuzzy Systems

The real world decision-making often involves a comparison of uncertain systems, or alternatives based on fuzzy evaluations. The concept of fuzzy entropy is quite useful in such situations. This paper critically examines the existing fuzzy entropy functions, and redefine them to add to their usefulness as measures of the fuzzy uncertainty in decision-making applications. More specifically, new variants of the extant Luca & Termini, and Pal & Pal fuzzy entropy functions are proposed. The proposed fuzzy entropy functions are extended for the probabilistic-fuzzy uncertainty, commonly observed in the real world. A real application is included to demonstrate the usefulness of the proposed entropy functions in decision-making applications.

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Journal Articles | 2019

A cutting plane approach for the multi-machine precedence-constrained scheduling problem

Prahalad Venkateshan, Joseph Szmerekovsky, and George Vairaktarakis

Annals of Operations Research

A cutting-plane approach is developed for the problem of optimally scheduling jobs with arbitrary precedence constraints on unrelated parallel machines to minimize weighted completion time. While the single machine version of this problem has attracted much research efforts, enabling solving problems with up to 100 jobs, not much has been done on the multiple machines case. A novel mixed-integer programming model is presented for the problem with multiple machines. For this model, many classes of valid inequalities that cut off fractional linear programming solutions are developed. This leads to an increase of the linear programming lower bound from 89.3 to 94.6% of the corresponding optimal solution, and a substantial reduction in the computational time of an optimal branch-and-bound algorithm for this problem. This enables us to report optimal solutions for problem instances with up to 25 jobs and 5 machines, which is more than twice the size of problems for which optimal solutions have been reported in the literature thus far. For a special case of the problem—that of minimizing makespan—application of our model helps solve 18 of 27 previously unsolved problem instances to optimality.

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Journal Articles | 2019

A new model for the asymmetric vehicle routing problem with simultaneous pickup and deliveries

Yogesh Kumar Agarwal and Prahalad Venkateshan

Operations Research Letters

The asymmetric vehicle routing problem with simultaneous pickup and deliveries is considered. This paper develops four new classes of valid inequalities for the problem. We generalize the idea of a no-good cut. Together, these help us solve 45-node randomly generated problem instances more efficiently. We report results on a set of benchmark instances in literature. In this set, we are able to show an order of magnitude improvement in computational times over currently published results in literature.

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Journal Articles | 2019

New valid inequalities for the optimal communication spanning tree problem

Yogesh Kumar Agarwal and Prahalad Venkateshan

Informs Journal On Computing

The problem of designing a spanning tree on an underlying graph to minimize the flow costs of a given set of traffic demands is considered. Several new classes of valid inequalities are developed for the problem. Tests on 10-node problem instances show that the addition of these inequalities results in integer solutions for a significant majority of the instances without requiring any branching. In the remaining cases, root gaps of less than 1% from the optimal solutions are realized. For 30-node problem instances, the inequalities substantially reduce the number of nodes explored in the branch-and-bound tree, resulting in significantly reduced computational times. Optimal solutions are reported for problems with 30 nodes, 60 edges, fully dense traffic matrices, and Euclidean distance-based flow costs. Problems with such flow costs are well-known to be a very difficult class of problems to solve. Using the inequalities substantially improves the performance of a variable-fixing heuristic. Some polyhedral issues relating to the strength of these inequalities are also discussed.

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Journal Articles | 2019

More is not always better: The case of counterterrorism security

Konrad Grabiszewski and Pritha Dev

Journal of Conflict Resolution

Can counterterrorism security be counterproductive? We argue that it can be when the at-risk population acts strategically. We model a two-stage game where the government first chooses the defensive security level for a public place. The second stage is a simultaneous-move game with terrorist choosing terror effort and members of the population deciding whether or not to attend the public place. Our key measure of the efficiency of the counterterrorism security is the expected number of casualties. Under very standard and general assumptions, we show that it is possible that more security leads to an increase in that number. This is because increasing security both discourages and encourages the terrorist. On the one hand, more security makes a successful terror attack less likely (discouragement). On the other hand, more security motivates more people to attend the public place which makes the attack more valuable to the terrorist (encouragement).

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Journal Articles | 2019

Restoration work: Responding to everyday challenges of HIV outreach

Neha Kumar, Azra Ismail, Samyukta Sherugar, and Rajesh Chandwani

Proceedings of the ACM Conference on Computer Supported Cooperative Work CSCW

There has been a growing commitment across the fields of Computer-Supported Cooperative Work (CSCW) and Human-Computer Interaction for Development (HCI4D) towards investigating the design and deployment of technologies in the context of complex healthcare ecologies. We present a qualitative inquiry of one such context, as we examine the outreach practices and everyday challenges of workers at a community-based organization in Gujarat (India) that works with People Living with the Human Immuno-deficiency Virus(PLHIV). Drawing on Yosso's framework of community cultural wealth-apt for such intersectional settings-and the lens of articulation work, we describe how the workers at Vikas build and strengthen varied forms of capital to restore "old normals," or what life was like for their PLHIV clients prior to diagnoses. Finally, we propose that attention to this nature of restoration work, and the workers' engagement with diverse forms of community cultural wealth, allows us to reflect on how technologies might (or might not) be designed to impact social and affective aspects of health.

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Journal Articles | 2019

Impact of vertical integration on market power in Indian manufacturing sector during the post-reform period

Rakesh Basant and Pulak Mishra

Journal of Industry Competition and Trade

In the context of declining degrees of vertical integration in major industries of Indian manufacturing sector during the post-reform period, the present paper is an attempt to examine how such “vertical disintegration” has affected firms’ market power and its implications for competition policy. Using panel dataset of 49 majors industries of Indian manufacturing sector for the period 2003–04 to 2010–11 and applying the system generalized method of moments approach to estimate of dynamic panel data models, the paper finds that vertical integration does not cause any significant impact on average market power of firms in an industry. Instead, it is influenced by market size, and selling and technology-related efforts. While selling intensity has a positive impact on market power, the impact of market size and technology intensity is found to be negative. Notably, like vertical integration, market concentration, import to export ratio, and capital intensity also do not have any significant impact on market power. The findings of this paper, therefore, have important implications for competition law and policy in general and policies and regulation relating to technology development and international trade in particular.

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Journal Articles | 2019

Quota-based affirmative action in higher education: Impact on other backward classes in India

Rakesh Basant and Gitanjali Sen

The Journal of Development Studies

While quota-based and other affirmative actions remain on the policy radar of nations faced with social inequalities, there is limited evidence informing policy choices at the national level. This paper estimates the mid-term impact of quota-based affirmative action in higher education (HE) in India implemented from 2008, which mandates that 27 per cent of seats are to be reserved for the Other Backward Classes (OBC) in public funded institutions of HE. Exploiting the differences in participation across social groups, age cohort,s and geographies with varied histories of affirmative action, our triple difference method estimates the impact of the Act by the year 2011–2012. Our results indicate that southern and northcentral states that already had quotas in place for a fairly long period of time, do not contribute much in further expansion of enrolment of OBCs; instead, the eastern region, where such a policy did not exist for long has about 0.12 points improvement in enrolment. Our estimates are robust to different specifications and the impact seems to be non-existent amongst the richest. It suggests that future policy initiatives need to be more nuanced considering regional differences in policy histories, supply of institutions, and extant rates of HE participation of the disadvantaged sections.

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Journal Articles | 2019

Exploring the role of urban green spaces in 'smartening' cities in India

Rama Mohana R Turaga, Sandip Chakrabarti, Urmila Jha-Thakur, and Dipita Hossain

Impact Assessment and Project Appraisal

This paper explores the conceptualization of Urban Green Space (UGS) within India’s urban planning process. In doing so, the context of the Smart Cities Mission (SCM), which is a flagship programme for urban transformation in the country, is chosen. We identified four key elements of UGS planning in the literature – quantity, accessibility, multifunctionality, and connectivity. Using this as a framework for analysis, we reviewed the national SCM guidelines and plans of four cities – Gwalior, Bhagalpur, Chandigarh, and Udaipur – in depth. We find that multifunctionality does not feature in the planning of UGS, and the notable absence of a connected, strategic vision suggests the need for strategic-level planning and assessment that goes beyond the project level in India.

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Journal Articles | 2019

Casting the net: India's public distribution system after the Food Security Act

Jean Dreze, Prankur Gupta, Reetika Khera, and Isabel Pimenta

Economic & Political Weekly

A broad-brush assessment of the public distribution system is presented in six of India’s poorest states—Bihar, Chhattisgarh, Jharkhand, Madhya Pradesh, Odisha, and West Bengal—soon after the National Food Security Act, 2013 came into force. Important gains have been made, including broader coverage, lower targeting errors, accelerated PDS reforms, and a greater political commitment to food security. In four of the six reference states, the PDS seems to be doing reasonably well, but Bihar and Jharkhand still have a long way to go. Even in the leading states, much remains to be done to achieve the purpose of the NFSA: ending food insecurity.

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