Generating remote entanglement via disentangling operations

Shared entanglement between spatially separated systems is an essential resource for quantum information processing including long-distance quantum cryptography and teleportation. While purification protocols for mixed distributed entangled quantum states exist, it is not clear how to optimally distribute entanglement to remote locations. Here, we describe a deterministic protocol for generating a maximally entangled state between remote locations that only uses local operations on qubits, and requires no classical communication between the separated parties. The procedure may provide protection from decoherence before the entanglement is "activated," and could be useful for quantum key distribution.Comment: 6 pages, 3 figure

Intervention in gene regulatory networks

In recent years Boolean Networks (BN) and Probabilistic Boolean Networks (PBN) have become popular paradigms for modeling gene regulation. A PBN is a collection of BNs in which the gene state vector transitions according to the rules of one of the constituent BNs, and the network choice is governed by a selection distribution. Intervention in the context of PBNs was first proposed with an objective of avoid- ing undesirable states, such as those associated with a disease. The early methods of intervention were ad hoc, using concepts like mean first passage time and alteration of rule based structure. Since then, the problem has been recognized and posed as one of optimal control of a Markov Network, where the objective is to find optimal strategies for manipulating external control variables to guide the network away from the set of undesirable states towards the set of desirable states. This development made it possible to use the elegant theory of Markov decision processes (MDP) to solve an array of problems in the area of control in gene regulatory networks, the main theme of this work. We first introduce the optimal control problem in the context of PBN models and review our solution using the dynamic programming approach. We next discuss a case in which the network state is not observable but for which measurements that are probabilistically related to the underlying state are available. We then address the issue of terminal penalty assignment, considering long term prospective behavior and the special attractor structure of these networks. We finally discuss our recent work on optimal intervention for the case of a family of BNs. Here we consider simultaneously controlling a set of Boolean Models that satisfy the constraints imposed by the underlying biology and the data. This situation arises in a case where the data is assumed to arise by sampling the steady state of the real biological network

Socio-economic differentials in intergenerational educational mobility among women in India

A few studies have related daughters’ education to their fathers in India but there is little to no evidence when it comes to intergenerational relation between daughters and mothers’ education. Using India Human Development Survey 2011-12, we investigate intergenerational educational mobility for women (15-49 years) (vis-à-vis their mothers). We have used mobility matrices/measures for the estimation. Findings indicate that intergenerational educational mobility at the all-India level is about 0.69, that is, 69% of the women acquire a level of education different from their mothers. Of the overall mobility, about 80% is contributed by upwards mobility whereas the rest is downwards. Mobility is greater in urban areas and is highest among the socially advantaged “Others” (or upper) caste group. Also, the upwards component is substantially lower for socially disadvantaged groups compared to Others. Further, there are large inter-regional variations, with situation being worst in the central and eastern regions which comprise of the underdeveloped states of India. Moreover, mobility (overall and upwards) increases consistently as one move up the income distribution. Furthermore, income is not able to neutralize the caste based gaps in overall mobility as overall mobility among the Others of the poorest income group is more than the overall mobility among Scheduled Castes/Tribes of the richest income group

Chuppi: Animated Short Film about a Child Sexual Abuse Victim

This is a project report for animated short film Chuppi: Animated Short Film about a Child Sexual Abuse Victim, submitted as a final project in partial fulfilment of the requirement for the award of the degree of Master of Design to Department of Design, Indian Institute of Technology Hyderabad. The report illustrates the process followed for the making of the movie. It is a common story for child sexual abuse victims, of what one goes through and how it affects their life, the trauma, and how they cope with it. I have tried to keep the visuals and language as simple as possible. The movie is an effort to give a boost to a victim to fight back with an alternative to sensitize children around not to stay quite if he or she observes sexual abuse

Recent Advances in Plasmonic Photocatalysis Based on TiO2 and Noble Metal Nanoparticles for Energy Conversion, Environmental Remediation, and Organic Synthesis

Plasmonic photocatalysis has emerged as a prominent and growing field. It enables the efficient use of sunlight as an abundant and renewable energy source to drive a myriad of chemical reactions. For instance, plasmonic photocatalysis in materials comprising TiO2 and plasmonic nanoparticles (NPs) enables effective charge carrier separation and the tuning of optical response to longer wavelength regions (visible and near infrared). In fact, TiO2-based materials and plasmonic effects are at the forefront of heterogeneous photocatalysis, having applications in energy conversion, production of liquid fuels, wastewater treatment, nitrogen fixation, and organic synthesis. This review aims to comprehensively summarize the fundamentals and to provide the guidelines for future work in the field of TiO2-based plasmonic photocatalysis comprising the above-mentioned applications. The concepts and state-of-the-art description of important parameters including the formation of Schottky junctions, hot electron generation and transfer, near field electromagnetic enhancement, plasmon resonance energy transfer, scattering, and photothermal heating effects have been covered in this review. Synthetic approaches and the effect of various physicochemical parameters in plasmon-mediated TiO2-based materials on performances are discussed. It is envisioned that this review may inspire and provide insights into the rational development of the next generation of TiO2-based plasmonic photocatalysts with target performances and enhanced selectivities.Peer reviewe

Efficient Asynchronous Verifiable Secret Sharing and Multiparty Computation

Secure Multi-Party Computation (MPC) providing information theoretic security allows a set of n parties to securely compute an agreed function F over a finite field ${\mathbb F}$, even if t parties are under the control of a computationally unbounded active adversary. Asynchronous MPC (AMPC) is an important variant of MPC, which works over an asynchronous network. It is well known that perfect AMPC is possible if and only if n \geq 4t+1, while statistical AMPC is possible if and only if n \geq 3t+1. In this paper, we study the communication complexity of AMPC protocols (both statistical and perfect) designed with exactly n = 4t+1 parties. Our major contributions in this paper are as follows: 1. Asynchronous Verifiable Secret Sharing (AVSS) is one of the main building blocks for AMPC. In this paper, we design two AVSS protocols with 4t+1 parties: the first one is statistically secure and has non-optimal resilience, while the second one is perfectly secure and has optimal resilience. Both these schemes achieve a common interesting property, which was not achieved by the previous schemes. Specifically, our AVSS schemes allow to share a secret through a polynomial of degree at most d, where t \leq d \leq 2t. In contrast, the existing AVSS schemes can share a secret only through a polynomial of degree at most t. The new property of our AVSS simplifies the degree reduction step for the evaluation of multiplication gates in an AMPC protocol. 2.Using our statistical AVSS, we design a statistical AMPC protocol with n = 4t+1 which communicates O(n^2) field elements per multiplication gate. Though this protocol has non-optimal resilience, it significantly improves the communication complexity of the existing statistical AMPC protocols. 3. We then present a perfect AMPC protocol with n = 4t+1 (using our perfect AVSS scheme), which also communicates O(n^2) field elements per multiplication gate. This protocol improves on our statistical AMPC protocol as it has optimal resilience. To the best of our knowledge, this is the most communication efficient perfect AMPC protocol in the information theoretic setting

On The Communication Complexity of Perfectly Secure Message Transmission in Directed Networks

In this paper, we re-visit the problem of perfectly secure message transmission (PSMT) in a directed network under the presence of a threshold adaptive Byzantine adversary, having unbounded computing power. Desmedt et.al have given the characterization for three or more phase PSMT protocols over directed networks. Recently, Patra et. al. have given the characterization of two phase PSMT over directed networks. Even though the issue of tradeoff between phase complexity and communication complexity of PSMT protocols has been resolved in undirected networks, nothing is known in the literature regarding directed networks. In this paper, we completely settle down this issue. Specifically, we derive the lower bounds on communication complexity of (a) two phase PSMT protocols and (b) three or more phase PSMT protocols in directed networks. Moreover, we show that our lower bounds are asymptotically tight, by designing communication optimal PSMT protocols in directed networks, which are first of their kind. We re-visit the problem of perfectly reliable message transmission (PRMT) as well. Any PRMT protocol that sends a message containing $\ell$ field elements, has a trivial lower bound of ­O($\ell$) field elements on its communication complexity. Thus any PRMT protocol that sends a message of $\ell$ eld elements by communicating O(\ell) field elements, is referred as communication optimal PRMT or PRMT with constant factor overhead. Here, we characterize the class of directed networks over which communication optimal PRMT or PRMT with constant factor overhead is possible. Moreover, we design a communication optimal PRMT over a directed network that satisfies the conditions stated in our characterization. Our communication optimal PRMT/PSMT protocols employ several new techniques based on coding theory, which are of independent interest

Unconditionally Secure Multiparty Set Intersection Re-Visited

In this paper, we re-visit the problem of unconditionally secure multiparty set intersection in information theoretic model. Li et.al \cite{LiSetMPCACNS07} have proposed a protocol for $n$-party set intersection problem, which provides unconditional security when $t < \frac{n}{3}$ players are corrupted by an active adversary having {\it unbounded computing power}. Moreover, they have claimed that their protocol takes six rounds of communication and incurs a communication complexity of ${\cal O}(n^4m^2)$, where each player has a set of size $m$. However, we show that the round complexity and communication complexity of the protocol in \cite{LiSetMPCACNS07} is much more than what is claimed in \cite{LiSetMPCACNS07}. We then propose a {\it novel} unconditionally secure protocol for multiparty set intersection problem with $n > 3t$ players, which significantly improves the actual round and communication complexity (as shown in this paper) of the protocol given in \cite{LiSetMPCACNS07}. To design our protocol, we use several tools which are of independent interest

Information Theoretically Secure Multi Party Set Intersection Re-Visited

We re-visit the problem of secure multiparty set intersection in information theoretic settings. In \cite{LiSetMPCACNS07}, Li et.al have proposed a protocol for multiparty set intersection problem with $n$ parties, that provides information theoretic security, when $t < \frac{n}{3}$ parties are corrupted by an active adversary having {\it unbounded computing power}. In \cite{LiSetMPCACNS07}, the authors claimed that their protocol takes six rounds of communication and communicates ${\cal O}(n^4m^2)$ field elements, where each party has a set containing $m$ field elements. However, we show that the round and communication complexity of the protocol in \cite{LiSetMPCACNS07} is much more than what is claimed in \cite{LiSetMPCACNS07}. We then propose a {\it novel} information theoretically secure protocol for multiparty set intersection with $n > 3t$, which significantly improves the actual round and communication complexity (as shown in this paper) of the protocol given in \cite{LiSetMPCACNS07}. To design our protocol, we use several tools which are of independent interest