370 research outputs found

    Productive water uses at household level in rural Kenya: case study of the Ukambani district

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    As a result of the growing world population and enhanced by the rising of living standards, competition for water is growing and this causes increased pressure on water resources worldwide. This tendency gave rise to the development of the integrated water resources management approach (IWRM), acknowledging the need to manage water resources in a holistic and integrated way. The IWRM objective to optimize economic, social and environmental outcomes of water management, can however only be reached if impact of water uses is correctly assessed. Nevertheless, often multiple uses of water within sectors are insufficiently recognized in planning and management. One of these neglected uses is the productive water use by households. Nonetheless, this use is extremely important to the livelihood of the poor, especially in the vast semi-arid rural areas of the developing world. An adequate evaluation of this use will not only help to improve outcome of water management, but will also add to the goal of poverty reduction. In this study, the role of productive water use for the rural community of the Ukambani district in Kenya was monitored, thereby focusing on income contributions and improvements in nutritional status

    Risk As A Function of Response Effort To Gain Points

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    The amount of risk an individual is willing to take may be a function of the amount of work required to earn the item that is risked. Twenty-four competitive basketball players were recruited and randomly assigned to one of three groups each representing either a low, moderate, or high work requirement to earn points. Participants were then given shots of varying point values and degrees of difficulty in which to wager points. Results indicate participants who were given a low response effort to gain points took significantly more risk as evidenced by choosing shots with the least probability of success. Those that were required to earn their points took significantly less risk evidenced by choosing shots with the highest probability of success

    Quantum fully homomorphic encryption with verification

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    Fully-homomorphic encryption (FHE) enables computation on encrypted data while maintaining secrecy. Recent research has shown that such schemes exist even for quantum computation. Given the numerous applications of classical FHE (zero-knowledge proofs, secure two-party computation, obfuscation, etc.) it is reasonable to hope that quantum FHE (or QFHE) will lead to many new results in the quantum setting. However, a crucial ingredient in almost all applications of FHE is circuit verification. Classically, verification is performed by checking a transcript of the homomorphic computation. Quantumly, this strategy is impossible due to no-cloning. This leads to an important open question: can quantum computations be delegated and verified in a non-interactive manner? In this work, we answer this question in the affirmative, by constructing a scheme for QFHE with verification (vQFHE). Our scheme provides authenticated encryption, and enables arbitrary polynomial-time quantum computations without the need of interaction between client and server. Verification is almost entirely classical; for computations that start and end with classical states, it is completely classical. As a first application, we show how to construct quantum one-time programs from classical one-time programs and vQFHE

    Expressiveness of real-time motion captured avatars influences perceived animation realism and perceived quality of social interaction in virtual reality

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    Using motion capture to enhance the realism of social interaction in virtual reality (VR) is growing in popularity. However, the impact of different levels of avatar expressiveness on the user experience is not well understood. In the present study we manipulated levels of face and body expressiveness of avatars while investigating participant perceptions of animation realism and interaction quality when disclosing positive and negative experiences in VR. Moderate positive associations were observed between perceptions of animation realism and interaction quality. Post-experiment questions revealed that many of our participants (approximately 40 %) indicated the avatar with the highest face and body expressiveness as having the most realistic face and body expressions. The same proportion also indicated the avatar with the highest face and body expressiveness as being the most comforting and enjoyable avatar to interact with. Our results suggest that higher levels of face and body expressiveness are important for enhancing perceptions of realism and interaction quality within a social interaction in VR using motion capture

    Asymptotic performance of port-based teleportation

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    Quantum teleportation is one of the fundamental building blocks of quantum Shannon theory. While ordinary teleportation is simple and efficient, port-based teleportation (PBT) enables applications such as universal programmable quantum processors, instantaneous non-local quantum computation and attacks on position-based quantum cryptography. In this work, we determine the fundamental limit on the performance of PBT: for arbitrary fixed input dimension and a large number N of ports, the error of the optimal protocol is proportional to the inverse square of N. We prove this by deriving an achievability bound, obtained by relating the corresponding optimization problem to the lowest Dirichlet eigenvalue of the Laplacian on the ordered simplex. We also give an improved converse bound of matching order in the number of ports. In addition, we determine the leading-order asymptotics of PBT variants defined in terms of maximally entangled resource states. The proofs of these results rely on connecting recently-derived representation-theoretic formulas to random matrix theory. Along the way, we refine a convergence result for the fluctuations of the Schur-Weyl distribution by Johansson, which might be of independent interest

    Multi-level socioecological drivers of agrarian change:Longitudinal evidence from mixed rice-livestock-aquaculture farming systems of Bangladesh

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    Coastal systems are facing natural and human-driven change coupled with a rising population. With increasing shifts in socioecological conditions during the past several decades, it is important to understand how socioecological drivers at different hierarchical levels: -micro, -meso, and -macro affect coastal farming systems, which play a crucial role in the livelihoods of coastal dwellers. Mixed rice-livestock-aquaculture farming in Southern Bangladesh exemplifies the rapid change occurring in many of the world's coastal farming systems in response to these drivers. We used panel data observations from the above study area and modeled trajectories of farm typologies, and the impact of multi-level socioecological drivers by a novel approach. Our approach integrates: (1) a well-articulated conceptual frame of change observed using (2) a temporal view of the potential drivers, change process and farm type outcomes, with the twenty years panel data of 502 households that is analyzed by means of (3) multivariate statistics in conjunction with panel data models that operationalize the conceptual frame. Our approach allows (a) estimating dynamic effects over time that typically cannot be estimated in a cross-sectional data set, (b) distinguishing between time-invariant fixed and time dependent random effects of multi-level socioecological drivers, and (c) controlling for omitted variables to a certain extent. Considering farming systems both within and outside of polder embankment systems intended to protect against oceanic water intrusion, we found a gradual shift from heterogeneous, rice-livestock farm types to more homogenous farms with less livestock and more off-farm activities. Micro-level factors including farm plot fragmentation, farmers' experience in cropping, machinery, salinity and soil fertility were influencing changes in farming systems. Meso-level factors including markets, road infrastructure, labor availability, access to extension and land tenure also affect the trajectory of farming systems change. Among macro-level drivers, increasing population density positively and significantly influenced cropping intensity among farms outside polder systems. Within polders, a positive but non-significant trend was observed for the influence of population density on cropping intensity. Our data also indicate negative and significant influence of cyclonic storms on cropping intensity over time in both areas. Our results underscore the importance of accounting for multiple levels of socioecological drivers of change when developing appropriate policy options for sustainable development in South Asia's coastal farming systems
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