Non-Cooperative Rational Interactive Proofs

Interactive-proof games model the scenario where an honest party interacts with powerful but strategic provers, to elicit from them the correct answer to a computational question. Interactive proofs are increasingly used as a framework to design protocols for computation outsourcing. Existing interactive-proof games largely fall into two categories: either as games of cooperation such as multi-prover interactive proofs and cooperative rational proofs, where the provers work together as a team; or as games of conflict such as refereed games, where the provers directly compete with each other in a zero-sum game. Neither of these extremes truly capture the strategic nature of service providers in outsourcing applications. How to design and analyze non-cooperative interactive proofs is an important open problem. In this paper, we introduce a mechanism-design approach to define a multi-prover interactive-proof model in which the provers are rational and non-cooperative - they act to maximize their expected utility given others\u27 strategies. We define a strong notion of backwards induction as our solution concept to analyze the resulting extensive-form game with imperfect information. We fully characterize the complexity of our proof system under different utility gap guarantees. (At a high level, a utility gap of u means that the protocol is robust against provers that may not care about a utility loss of 1/u.) We show, for example, that the power of non-cooperative rational interactive proofs with a polynomial utility gap is exactly equal to the complexity class P^{NEXP}

Rational Proofs with Multiple Provers

Interactive proofs (IP) model a world where a verifier delegates computation to an untrustworthy prover, verifying the prover's claims before accepting them. IP protocols have applications in areas such as verifiable computation outsourcing, computation delegation, cloud computing. In these applications, the verifier may pay the prover based on the quality of his work. Rational interactive proofs (RIP), introduced by Azar and Micali (2012), are an interactive-proof system with payments, in which the prover is rational rather than untrustworthy---he may lie, but only to increase his payment. Rational proofs leverage the provers' rationality to obtain simple and efficient protocols. Azar and Micali show that RIP=IP(=PSAPCE). They leave the question of whether multiple provers are more powerful than a single prover for rational and classical proofs as an open problem. In this paper, we introduce multi-prover rational interactive proofs (MRIP). Here, a verifier cross-checks the provers' answers with each other and pays them according to the messages exchanged. The provers are cooperative and maximize their total expected payment if and only if the verifier learns the correct answer to the problem. We further refine the model of MRIP to incorporate utility gap, which is the loss in payment suffered by provers who mislead the verifier to the wrong answer. We define the class of MRIP protocols with constant, noticeable and negligible utility gaps. We give tight characterization for all three MRIP classes. We show that under standard complexity-theoretic assumptions, MRIP is more powerful than both RIP and MIP ; and this is true even the utility gap is required to be constant. Furthermore the full power of each MRIP class can be achieved using only two provers and three rounds. (A preliminary version of this paper appeared at ITCS 2016. This is the full version that contains new results.)Comment: Proceedings of the 2016 ACM Conference on Innovations in Theoretical Computer Science. ACM, 201

Response of Soil and Water Quality to Winter Manure Application from Small Agricultural Watersheds in South Dakota

The extreme winter conditions prevailing in the state of South Dakota make it difficult for the livestock producers to manage the manure generated at the farm. The South Dakota Department of Environmental and Natural Resources does not recommend manure application in the state during the winter months when the ground is frozen. Thus, producers are left with the options such as storing the manure over a longer period until summer or spreading on snow or frozen ground. Storing manure for longer duration leads to increased risks of concentrated spills into the streams. Thus, it is important to develop management strategies for manure to reduce negative impacts to the environment. The present study was conducted to test the hypothesis that manure spread near the outlets of the watersheds would lead to an increased loss of nutrients as compared to the manure spread away from the watershed outlets. A paired watershed study was established near Colman, South Dakota, in which two watersheds were used as treatment watersheds while one was used as control. The watersheds were named as north (NW), south (SW) and east (CW) watersheds; north and south were treatment watersheds while east was the control. The North watershed received manure application on 50% area close to its outlet while south watershed received manure 50% of its area away from its outlet. At the East watershed and the areas in the north and south watershed that did not receive any manure, inorganic fertilizer was applied to meet the nutrient needs for the crop growth. Surface runoff was measured from the three watersheds, and runoff samples were collected from 2013 to 2015 to assess the impacts of manure application on water quantity and quality. Soil samples were also extracted from the three watersheds to measure the physical and chemical properties as impacted by the manure treatment. In addition, soil erosion was estimated using the Revised Universal Soil Loss Equation 2 (RUSLE2) model. Results from this study showed that soil quality, organic matter and water infiltration improved in the landscape positions that received the manure application. Manure improved the infiltration capacity of the soil and also improved the nutrient status of the soil. Runoff data did not show any particular trend among the three watersheds, rather, it varied according to the precipitation pattern and the topography of the watershed. The runoff depth was not statistically significant across the three watersheds. The north watershed showed the highest loss of nutrients into the streams while the south watershed showed the lowest. The east watershed also showed high nutrient losses which may be due to high solubility of the inorganic fertilizers. Soil erosion results showed that topography (LS factor in RUSLE) played the most important role in determining the soil erosion. Our soil erosion estimation results were coherent with the results obtained for the total suspended solids. Thus, it can be concluded that manure treatment in the south watershed showed best results in terms of reduced water quality impairment and soil erosion as nutrient concentrations in the surface runoff samples were significantly higher from the NW as compared to the other watersheds. Results from this study would provide an insight to the producers about managing manure during winter months. In addition, monitoring water quantity and quality for longer duration is strongly encouraged to assess the impacts of manure on soils and water

The Changed Reality of Design Education and Modes that Could Work for The Future

Today more than ever before the need for designers has become a way of life. From designing a party or being an event manager to partnering with engineers on all kinds of projects, knowledge of design is, in a manner of speaking, a prerequisite. Therefore, it is imperative that design education is rethought in all possible branches of Arts, Crafts and Engineering. From Bauhaus till now the design education has gone through a revolution globally and there is no reason for that revolution to slowdown or stop. We are only called to enhance the same by creating competent designers. Education being the foundation of a better tomorrow implies we do the same with design education. Paul Rand said, �Design is a way of life, a point of view. It involves the whole complex of visual communications: talent, creative ability, manual skill, and technical knowledge. Aesthetics and economics, technology and psychology are intrinsically related to the process.� As the maxim goes, �Well begun is half done,� there are no two ways of doing education. We need to be purpose driven with a clear vision and a sense of mission to ensure a universal approach towards design education across India along with a well calibrated design curriculum and we will be on our way to rewriting the history of design education in India

Crystallization of triethyl-citrate-plasticized poly(lactic acid) induced by chitin nanocrystals

The aim of this study was to gain a better understanding of the crystallization behavior of triethyl-citrate-plasticized poly(lactic acid) (PLA–TEC) in the presence of chitin nanocrystals (ChNCs). The isothermal crystallization behavior of PLA–TEC was studied by polarized optical microscopy, scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction (XRD). Interestingly, the addition of just 1 wt % ChNCs in PLA–TEC increased the crystallization rate in the temperature range of 135–125 °C. The microscopy studies confirmed the presence of at least three distinct types of spherulites: negative, neutral, and ring banded. The ChNCs also increased the degree of crystallinity up to 32%, even at a fast cooling rate of 25¿°C min-1. The XRD studies further revealed the nucleation effect induced by the addition of ChNCs and thus explained the faster crystallization rate. To conclude, the addition of a small amount (1 wt %) of ChNC to plasticized PLA significantly affected its nucleation, crystal size, and crystallization speed; therefore, the proposed route can be considered suitable for improving the crystallization behavior of PLA.Peer ReviewedPostprint (author's final draft

Toxicological approach of Parthenium Hysterophorus (linn.) On sperm dynamics and male fertility of rattus norvegicus

Parthenium hysterophorus Linn., an exotic plant has now dominated most of the herbaceous flora of many countries. It is a weed of national significance belongs to family Asteraceae. The compound Parthenin extracted from parthenium hysterophorus was orally administrated to Rattus norvegicus at 60.0 mg/kg b.wt. for acute and 2.o mg/kg b.wt. for sub-chronic (30 days) treatment to study its impact on testicular fertility parameters to different groups of animals. Results from the present study have elucidated that sperm parameters (Fertility index, sperm count, sperm motility and sperm abnormality) showed a marked decrease in their functioning, and toxic effects on male reproductive functions. The observed testicular changes are suggestive of testes dysfunction and additional mode of action of Parthenium leaf extract

Lower Socio-economic Status and Cardiovascular Disease: Role of Healthcare Facility and Policy in India

Background: Cardio-vascular disease (CVD) is one of the main cause of mortality Worldwide and India is no exception. Unlike developed countries, where both CVD prevalence and mortality has been established to affect lower socio-economic status (SES), in India there is no consensus among researchers over socio-economic patterning of CVD prevalence but the mortality rate has been reported to disproportionately affect the economically weaker sections. Aims & Objectives: This article, focuses at the issue of how lack of good healthcare facilities and non-supportive health policies are affecting CVD mortality positively among lower SES of India. Challenges of the Indian healthcare system in context of lower SES can be described in terms of the issue of availability, accessibility and affordability. Inadequate policy and public healthcare system either leads to the problem of high Out-of-Pocket Payments (OPP) or opting out of the treatment, which further increases poverty and mortality among them. Moreover, limited insurance coverage and inadequate regulatory policies for alcohol and tobacco-leading CVD risk factors among lower SES groups – do little to discourage its use among them. Conclusion: Since, lower SES people in India are already under the burden of communicable diseases, government should take immediate steps to control the mortality among them by creating a supportive environment through pro-poor health policies and healthcare facilities