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The topological shadow of F1 -geometry: congruence spaces
No full textIn this paper we introduce congruence spaces, which are topological spaces that are canonically attached to monoid schemes and that reflect closed topological properties. This leads to satisfactory topological characterizations of closed morphisms and closed immersions as well as separated and proper morphisms. We study congruence spaces thoroughly and extend standard results from usual scheme theory to monoid schemes: a closed immersion is the same as an affine morphism for which the pullback of sections is surjective; a morphism is separated if and only if the image of the diagonal is a closed subset of the congruence space; a valuative criterion for separated and proper morphisms
TIGHT SECURITY ANALYSIS OF THE PUBLIC PERMUTATION-BASED PMAC Plus
No full textIn CRYPTO 2011, Yasuda proposed a variable input-length PRF based on an n-bit block cipher, called PMAC Plus. PMAC Plus is a rate-1 construction and inherits the well-known PMAC parallel network with a low additional cost. However, unlike PMAC, PMAC Plus is secure roughly up to 22n/3 queries. Later in CRYPTO 2018, Leurent et al., and then Lee et al. in EUROCRYPT 2020 established a tight security bound of 23n/4 on PMAC Plus. In this paper, we propose a public permutation-based variable input-length PRF called pPMAC Plus. We show that pPMAC Plus is secure against all adversaries that make at most 22n/3 queries. We also show that the bound is essentially tight. It is of note here that instantiation of each block cipher of PMAC Plus with the two-round iterated Even-Mansour cipher can yield a beyond-birthday-secure PRF based on public permutations. Altogether, the solution incurs (2ℓ + 4) permutation calls, whereas our proposal requires only (ℓ + 2) permutation calls, ℓ being the maximum number of message blocks
Tolerance of shiftability parameters of an automobile gear box: a case study
No full textThis is a case study on determining the specification tolerances of the shiftability parameters of a gear box of a well-known brand of passenger car. The company was experiencing difficulty in setting up the specification tolerance, resulting in problems during the manufacturing process. The shiftability parameters Yi\u27s are related to the dimensions of ni components 1, 2 , , . X X Xni The experimental design technique of Taguchi as modified by D\u27Errico and Zanio (1988) was used to find the probability distribution of all the shiftability parameters Yi\u27s. The tolerance limits ( , ) LYi UYi for the Yi\u27s were calculated after having selected 99% probability levels. These tolerance were applied to the shiftability parameters and a few prototypes were manufactured. The results obtained on these prototypes were encouraging and, hence, subsequently they were used by the design department in the gear box assembly
Women’s Work in Livestock Raising: Evidence from Time Use Surveys in India
No full textWomen’s contribution to livestock raising, in terms of both work participation and hours of work, is underestimated in India as elsewhere in the world. This is primarily because of limitations of data available in labour force surveys, many of which can be addressed by time use surveys (TUSs). This paper, first, explores data from a small TUS conducted in two villages of Karnataka. Insights from our ground-level study are tested econometrically by applying a two-way Heckman model to unit data from India’s first national TUS, 2019. We estimated that 11 per cent of rural women participated in livestock raising and spent an average of 16 h a week. Age and education were significant factors: younger and educated women were less likely to engage in livestock raising, an observation linked to current technology and drudgery of work. Women’s participation was higher in peasant households from privileged social groups than in poorer wage worker households
A Sponge-Based PRF with Good Multi-user Security
No full textBoth multi-user PRFs and sponge-based constructions have generated a lot of research interest lately. Dedicated analyses for multiuser security have improved the bounds a long distance from the early generic bounds obtained through hybrid arguments, yet the bounds generally don’t allow the number of users to be more than birthday-bound in key-size. Similarly, known sponge constructions suffer from being only birthday-bound secure in terms of their capacity. We present in this paper Muffler, a multi-user PRF built from a random permutation using a fullstate sponge with feed-forward, which uses a combination of the user keys and unique user IDs to solve both the problems mentioned by improving the security bounds for multi-user constructions and sponge constructions. For D construction query blocks and T permutation queries, with key-size κ = n/2 and tag-size τ = n/2 (where n is the state-size or the size of the underlying permutation), both D and T must touch birthday bound in n in order to distinguish Muffler from a random function
Aquaformer: Underwater Image Enhancement via Adaptive Transformer
No full textWater causes degradation of quality in optical images captured underwater due to its physical properties of absorption and scattering. This degradation is further aggravated by the increase in water depth and the presence of contaminated water. Transformers in the vision domain have made a quantum leap in many vision tasks such as detection, and segmentation but yet to make any progress in enhancing degraded underwater images. We propose a transformer-based model named \u27Aquaformer\u27 which makes four major contributions: an adaptive layer normalization, replacement of masked cyclic shift with symmetric padding in window partitioning, a novel aggregation mechanism, and an adjustable fusion approach. These succeed in making the model a very powerful one, producing significantly better performance compared to the latest state-of-the-art methods. Testing on multiple benchmark datasets, employing both quantitative and qualitative metrics, establishes its supremacy
Iterative Watershed Partition: An Efficient Method for Hierarchical River-Basin Extraction on Digital Elevation Models
No full textWatershed partitioning, following a maximal vertex-cut constraint, ensures each basin is strictly isolated from its neighboring basins. This partition is composed of watershed arcs positioned between pairs of adjacent basins. When these arcs create a connected partition, applying watershed partition on an arc-graph ensures that the corresponding arcs of watershed points in the arc-graph still maintain this connected partition. This crucial property is leveraged in the proposed iterative watershed partition method for extracting hierarchical partition lines in an image. The method effectively extracts river basins from SRTM DEM data of the Indian state Uttarakhand, revealing a well-structured hierarchy of catchment basins
On the Solution Set of Semi-infinite Tensor Complementarity Problem
No full textTo give a method for thinking about a more practical scenario of the problem, we introduce the semi-infinite tensor complementarity problem in this study. We provide the sufficient and necessary conditions for the solution set’s existence. We examine the solution set’s error bounds in this case using the residual function
Optimized QAOA ansatz circuit design for two-body Hamiltonian problems
No full textQuantum Approximate Optimization Algorithm (QAOA) is a prospective candidate for providing quantum advantage in finding approximate solutions to optimization problems using near-term quantum devices. In this paper, the goal is to reduce the number of CNOT gates and the depth of quantum ansatz circuits for QAOA. First, we present a generalized QAOA formulation for any Hamiltonian that involves upto two-body interactions, as a graph. The circuit realization of the depth-p QAOA requires 2mp CNOT gates where the graph for the Hamiltonian has n vertices and m edges. Presently, a CNOT gate is one of the primary sources of error. We propose a graph-theoretic algorithm which can eliminate n-1 CNOTs from the QAOA ansatz while retaining functional equivalence with the original circuit. This improves upon previously proposed Depth First Search (DFS) method by restricting the increase in depth of the circuit, which was a drawback of the method, by ≃ 84.8% for Erds-Renyi graphs. Finally, if the underlying connectivity (hardware coupling map) and the initial qubit placement for a hardware are known, then we present how to extend the greedy heuristic method in order to obtain a functionally equivalent circuit with ≃ 5%; fewer SWAP gates for Erds-Renyi graphs
Segmentation and Labeling of Vertebra Using SegFormer Architecture
No full textVertebra segmentation and labeling in MR images of the spine play a vital role in the identification of diseases or anomalies. MRI captures the tissue structure of a spine accurately, hence it is essential to demarcate and identify the vertebra in the MRI image. There are both supervised and unsupervised methods for vertebra segmentation and labeling. However, the acquisition of requisite data is a challenge to designing methods with very high accuracy. In this work, we have modified a transformer-based architecture called Segformer for semantic segmentation of 3D sliced data. Our method leverages transfer learning on low-population data. With a new advanced masking logic, we achieve 99% accuracy for segmentation and labeling of lumbar spine MR images