Acoustic emission signal ‘peak amplitude-distribution’ analysis related to concrete fracture under uniaxial compression

Acoustic emissions (AE) released during the compressive fracture of cementitious materials have been subjected to analysis using ‘AE based b-value’ to study the fracture process. Identification of the ‘AE sources locations’ in three dimension is not always possible. With a minimum number of AE sensors mounted on the test specimen and by using the AE based b-value analysis, it is possible to study fracture process and the damage status in solids. The b-value of AE is calculated using the Gutenberg–Richter empirical relationship (G-R law), which is available in seismology. The details related to original G-R relation and it’s suitability for AE testing were discussed. In this article it has been tried to look into the variations of the AE based b-value in cementitious test specimens prepared with different cementitious mixture proportions. Effect of (i) coarse aggregate size in cementitious materials (ii) loading rate during compressive fracture process (iii) age of concrete on b-value variation were discussed. The trend of variation in AE based b-value during fracture process in concrete and mortar was different. It was observed that when the compression toughness of the cementitious material increases, higher b-values were observed. When the loading rate was high, quick cracking occurred and lower b-values were observed. As the coarse aggregate size in the cementitious material increases, the cumulative AE energy was higher. The reason may be due to the compression toughness of the cementitious material. The AE based b-value is useful to identify the different stages of compressive fracture process in solids

A Fixed-Parameter Tractable Algorithm for Counting Markov Equivalence Classes with the same Skeleton

Causal DAGs (also known as Bayesian networks) are a popular tool for encoding conditional dependencies between random variables. In a causal DAG, the random variables are modeled as vertices in the DAG, and it is stipulated that every random variable is independent of its ancestors conditioned on its parents. It is possible, however, for two different causal DAGs on the same set of random variables to encode exactly the same set of conditional dependencies. Such causal DAGs are said to be Markov equivalent, and equivalence classes of Markov equivalent DAGs are known as Markov Equivalent Classes (MECs). Beautiful combinatorial characterizations of MECs have been developed in the past few decades, and it is known, in particular that all DAGs in the same MEC must have the same ''skeleton'' (underlying undirected graph) and v-structures (induced subgraph of the form $a\rightarrow b \leftarrow c$). These combinatorial characterizations also suggest several natural algorithmic questions. One of these is: given an undirected graph $G$ as input, how many distinct Markov equivalence classes have the skeleton $G$? Much work has been devoted in the last few years to this and other closely related problems. However, to the best of our knowledge, a polynomial time algorithm for the problem remains unknown. In this paper, we make progress towards this goal by giving a fixed parameter tractable algorithm for the above problem, with the parameters being the treewidth and the maximum degree of the input graph $G$. The main technical ingredient in our work is a construction we refer to as shadow, which lets us create a "local description'' of long-range constraints imposed by the combinatorial characterizations of MECs.Comment: 75 pages, 2 Figure

Planned ambitions versus lived realities: an examination of the BSUP scheme in the periphery of Mumbai

This research examined the BSUP scheme in the periphery of Mumbai for its effectiveness in creating upward social mobility and social integration amongst the urban poor, which is the main objective of the scheme. The scheme is a part of the neoliberal-era settlement rehousing schemes in India that offer tenure security to the urban poor (A. Roy, 2014). The examination of the scheme involved investigating the scheme’s pre-, during-, and post-implementation phases in Kalyan Dombivli (KD) city – a 1.2 million population sub-city in the Mumbai city region – at a range of spatial scales – that include the scale of city and region, of neighbourhood/community, and that of the household. The research adopted a qualitative case study approach for its context-sensitivity (Yin, 2014; c.f. Porta Della & Keating, 2008). A longitudinal and a multi-scalar examination of the scheme was based upon and contributed to two sets of literature – the first is the human agential and the process-oriented approaches of ‘the quiet encroachment of the ordinary’ (Bayat, 2004), and that of ‘place-making’ (Lombard, 2015) and the second is the literature on (neoliberal) governmentalities and how these are accomplished and experienced under the everyday settings (Rose & Miller, 1992; Li, 1999; Sharma, 2008; Charlton, 2014; Charlton & Meth, 2017). The examination of the case revealed that the scheme’s essentialist-universalistic imaginaries of the ‘slums’, ‘slum’ dwellers and the outcomes of the ‘slum’ redevelopment met differently with the ground realities in KD. Findings reveal that the spatial-relational constitution of heterogeneity amongst the poorer groups plays a key role in the way they engage with the accomplishment of the BSUP scheme and experience the BSUP housing. This thesis draws attention to the significance of examining the process of poorer groups’ settlement transformation in understanding how they accomplish and experience the rehousing governmentalities

Codes over the non-unital non-commutative ring EE using simplicial complexes

There are exactly two non-commutative rings of size $4$, namely, $E = \langle a, b ~\vert ~ 2a = 2b = 0, a^2 = a, b^2 = b, ab= a, ba = b\rangle$ and its opposite ring $F$. These rings are non-unital. A subset $D$ of $E^m$ is defined with the help of simplicial complexes, and utilized to construct linear left-$E$-codes $C^L_D=\{(v\cdot d)_{d\in D} : v\in E^m\}$ and right-$E$-codes $C^R_D=\{(d\cdot v)_{d\in D} : v\in E^m\}$. We study their corresponding binary codes obtained via a Gray map. The weight distributions of all these codes are computed. We achieve a couple of infinite families of optimal codes with respect to the Griesmer bound. Ashikhmin-Barg's condition for minimality of a linear code is satisfied by most of the binary codes we constructed here. All the binary codes in this article are few-weight codes, and self-orthogonal codes under certain mild conditions. This is the first attempt to study the structure of linear codes over non-unital non-commutative rings using simplicial complexes.Comment: 20 page

Marketing System and Efficiency of Indian Major Carps in India

The Kolleru Lake area (KLA) in Andhra Pradesh being a predominant centre for carp culture is known as the ‘Carp Pocket of India’. This paper has described the highly efficient fish marketing system prevalent in the KLA and has compared it with the marketing of Indian Major Carps (IMC) in other major aquaculture states like West Bengal and Orissa and marine states like Maharashtra and Tamil Nadu. The marketing channels, market intermediaries, price spread and marketing efficiency have been presented. A comparison of the marketing channels at several fish markets has revealed that the price spread for IMC from Kolleru is highest at the Mumbai market and lowest at the Coimbatore market. Consequently, fishermen’s share in consumer price has been found highest for Coimbatore at 61.54 per cent and lowest for Mumbai at 47.06 per cent. Similarly, the marketing efficiency was the highest for Coimbatore at 2.60 and lowest for Mumbai at 1.89. Retail price for KLA carps has been found lower than locally cultured carps at various areas, reflecting the efficiency of the marketing channel in providing cheap fish transported over large distances and through a large number of intermediaries. The reasons for the efficient IMC marketing system at KLA have been discussed and the study has recommended the development of efficient fish marketing system in other parts of the country.Agricultural and Food Policy,

A Survelliance Model: Two Machine Case

1 online resource (PDF, 28 pages

Subfield codes of CDC_D-codes over F2[x]/⟨x3−x⟩\mathbb{F}_2[x]/\langle x^3-x \rangle are really nice!

A non-zero $\mathbb{F}$-linear map from a finite-dimensional commutative $\mathbb{F}$-algebra to $\mathbb{F}$ is called an $\mathbb{F}$-valued trace if its kernel does not contain any non-zero ideals. In this article, we utilize an $\mathbb{F}_2$-valued trace of the $\mathbb{F}_2$-algebra $\mathcal{R}_2:=\mathbb{F}_2[x]/\langle x^3-x\rangle$ to study binary subfield code $\mathcal{C}_D^{(2)}$ of $\mathcal{C}_D:=\{\left(x\cdot d\right)_{d\in D}: x\in \mathcal{R}_2^m\}$ for each defining set $D$ derived from a certain simplicial complex. For $m\in \mathbb{N}$ and $X\subseteq \{1, 2, \dots, m\}$, define \Delta_X:=\{v\in \mathbb{F}_2^m: \Supp(v)\subseteq X\} and $D:=(1+u^2)D_1+u^2D_2+(u+u^2)D_3,$ a subset of $\mathcal{R}_2^m,$ where $u=x+\langle x^3-x\rangle, D_1\in \{\Delta_L, \Delta_L^c\},\, D_2\in \{\Delta_M, \Delta_M^c\}$ and $D_3\in \{\Delta_N, \Delta_N^c\}$, for $L, M, N\subseteq \{1, 2, \dots, m\}.$ The parameters and the Hamming weight distribution of the binary subfield code $\mathcal{C}_D^{(2)}$ of $\mathcal{C}_D$ are determined for each $D.$ These binary subfield codes are minimal under certain mild conditions on the cardinalities of $L, M$ and $N$. Moreover, most of these codes are distance-optimal. Consequently, we obtain a few infinite families of minimal, self-orthogonal and distance-optimal binary linear codes that are either $2$-weight or $4$-weight. It is worth mentioning that we have obtained several new distance-optimal binary linear codes