...it is unclear whether people mean the same thing when using the terms "SIF" or "potential SIF." ...no single company-regardless of its size-has enough information to discover how to eliminate SIFs ...by itself; SIF elimination requires the collaboration of the entire safety community. Definitions are more useful when they are precise, concise, clear and easy to apply. ...this article explains why a definition of a serious injury is needed, creates a definition of "serious injury" based on empirical evidence and consensus among experts, and builds a decision model aligned with the definition that enables consistent classification. About 7 decades after the discovery of Pluto, a community of astronomers in the International Astronomical Union voted on a new intensional definition of the word "planet."
Safety training despite being the key measure to keeping workers safe within any occupational environment has not kept pace with the significant advancement in the fields of behavioral psychology and ...education. As a result, researchers have found that the pre-dated safety training techniques on construction sites fail in communicating information in a way that promotes long-term retention of knowledge among adult learners and they also end up generating a negative attitude towards safety among workers. Understanding the psychological antecedents to risk-taking behavior and utilizing prominent adult learning theories to revolutionize safety training could allow academics and practitioners to improve workers’ hazard recognition performance and risk assessment skills while promoting risk-averse behavior. This dissertation therefore aims to (1) test and validate the role of integral and incidental affective arousal in influencing key safety outcomes (hazard recognition performance, valuation of danger, and safety decisions); (2) use the findings to design a safety training program that generates targeted affective arousal but is also rooted in self-directed learning model to facilitate learning; (3) deliver the simulation-based multimedia training module as an intervention to construction workers in a quasi-field experiment to measure changes in affect and situational interest; and (4) apply multivariate statistics to validate if the training environment generated the desired emotional engagement and learning outcomes among workers. Analysis of the proposed conceptual model showed that the integral negative affective arousal increased perception of risk and promoted risk-averse decision-making in construction safety training context. The quasi-field experiment on 489 construction workers showed that the proposed safety training module generated context-driven negative emotions and also improved situational interest levels regarding safety training which is a primary precursor to learning. Moreover, these results were consistent across all relevant demographical groups common to construction sites in the United States. This work is the first effort that ascertains the efficacy of various adult learning mechanisms incorporated in the proposed training module and also validates relationship between affect, risk perception, and decision-making in an occupational training environment. Future research should seek to validate the application of this format of safety training for safety training in other domains and study the long-term effects of such training on skills and retention of knowledge of the workforce.
...research suggests that high-quality leadership interventions yield positive effects on the emotional, behavioral and social status of employees, which translates into improved work performance ...(Babcock-Roberon & Strickland, 2010). Most peer-reviewed studies on safety leadership that involve empirical data have focused primarily on the role of on-site leadership (e.g., project managers, frontline supervisors, crew or team leads) and their impact on collectivism, compliance to rules and regulations, and overall performance (Conchie et al., 2013; Jiang et al, 2017). ...most validated leadership performance survey instruments are designed to evaluate the personal qualities of a leader and their leadership styles, rather than the quality of an engagement between the leader and employees (Avolio & Bass, 2004). ...what leaders pay attention to, react to, allocate resources for and acknowledge in their engagements with employees can form the foundation for their organization's safety culture. Research Methods The authors' goal was to produce a scoring protocol for safety-focused leadership engagements that reflects the consensus of a panel of industry experts. ...the authors adopted a multiphased focus group research protocol to address
We highlight the usefulness of city-scale agent-based simulators in studying various non-pharmaceutical interventions to manage an evolving pandemic. We ground our studies in the context of the ...COVID-19 pandemic and demonstrate the power of the simulator via several exploratory case studies in two metropolises, Bengaluru and Mumbai. Such tools may in time become a common-place item in the tool kit of the administrative authorities of large cities.
A subset \(\mathcal{C}\subseteq\{0,1,2\}^n\) is said to be a \(\textit{trifferent}\) code (of block length \(n\)) if for every three distinct codewords \(x,y, z \in \mathcal{C}\), there is a ...coordinate \(i\in \{1,2,\ldots,n\}\) where they all differ, that is, \(\{x(i),y(i),z(i)\}\) is same as \(\{0,1,2\}\). Let \(T(n)\) denote the size of the largest trifferent code of block length \(n\). Understanding the asymptotic behavior of \(T(n)\) is closely related to determining the zero-error capacity of the \((3/2)\)-channel defined by Elias'88, and is a long-standing open problem in the area. Elias had shown that \(T(n)\leq 2\times (3/2)^n\) and prior to our work the best upper bound was \(T(n)\leq 0.6937 \times (3/2)^n\) due to Kurz'23. We improve this bound to \(T(n)\leq c \times n^{-2/5}\times (3/2)^n\) where \(c\) is an absolute constant.
Average Treatment Effect (ATE) estimation is a well-studied problem in causal inference. However, it does not necessarily capture the heterogeneity in the data, and several approaches have been ...proposed to tackle the issue, including estimating the Quantile Treatment Effects. In the finite population setting containing \(n\) individuals, with treatment and control values denoted by the potential outcome vectors \(\mathbf{a}, \mathbf{b}\), much of the prior work focused on estimating median\((\mathbf{a}) -\) median\((\mathbf{b})\), where median(\(\mathbf x\)) denotes the median value in the sorted ordering of all the values in vector \(\mathbf x\). It is known that estimating the difference of medians is easier than the desired estimand of median\((\mathbf{a-b})\), called the Median Treatment Effect (MTE). The fundamental problem of causal inference -- for every individual \(i\), we can only observe one of the potential outcome values, i.e., either the value \(a_i\) or \(b_i\), but not both, makes estimating MTE particularly challenging. In this work, we argue that MTE is not estimable and detail a novel notion of approximation that relies on the sorted order of the values in \(\mathbf{a-b}\). Next, we identify a quantity called variability that exactly captures the complexity of MTE estimation. By drawing connections to instance-optimality studied in theoretical computer science, we show that every algorithm for estimating the MTE obtains an approximation error that is no better than the error of an algorithm that computes variability. Finally, we provide a simple linear time algorithm for computing the variability exactly. Unlike much prior work, a particular highlight of our work is that we make no assumptions about how the potential outcome vectors are generated or how they are correlated, except that the potential outcome values are \(k\)-ary, i.e., take one of \(k\) discrete values.
We present a randomized algorithm that takes as input an undirected
$n$-vertex graph $G$ with maximum degree $\Delta$ and an integer $k > 3\Delta$,
and returns a random proper $k$-coloring of $G$. ...The distribution of the
coloring is \emph{perfectly} uniform over the set of all proper $k$-colorings;
the expected running time of the algorithm is
$\mathrm{poly}(k,n)=\widetilde{O}(n\Delta^2\cdot \log(k))$. This improves upon
a result of Huber~(STOC 1998) who obtained a polynomial time perfect sampling
algorithm for $k>\Delta^2+2\Delta$. Prior to our work, no algorithm with
expected running time $\mathrm{poly}(k,n)$ was known to guarantee perfectly
sampling with sub-quadratic number of colors in general. Our algorithm (like
several other perfect sampling algorithms including Huber's) is based on the
Coupling from the Past method. Inspired by the \emph{bounding chain} approach,
pioneered independently by Huber~(STOC 1998) and H\"aggstr\"om \&
Nelander~(Scand.{} J.{} Statist., 1999), we employ a novel bounding chain to
derive our result for the graph coloring problem.
We consider the problem of determining the zero-error list-decoding capacity of the q /(q-1) channel studied by Elias (1988). The q /(q-1) channel has input and output alphabet consisting of q ...symbols, say, \mathcal{X}=\{x_{1}, x_{2}, \ldots, x_{q} ; when the channel receives an input x\in \mathcal{X} , it outputs a symbol other than x itself. Let n(m,\ q,\ \ell) be the smallest n for which there is a code \mathcal{C}\subseteq \mathcal{X}^{n} of m elements such that for every list w_{1}, w_{2},\ldots, w_{\ell+1} of distinct code-words from C, there is a coordinate j\inn that satisfies \{w_{1}j,\ w_{2}j,\ldots, w_{\ell+1}j\}=\mathcal{X} . We show that for all constants \alpha\geq 1 , we have n(m,\ q,\ \alpha q)=\exp(\Omega(q))\log m . The lower bound obtained by Fredman and Komlós (1984) for perfect hashing implies that n(m,\ q,\ q-1)=\exp(\Omega(q))\log m ; similarly, the lower bound obtained by Körner (1986) for nearly-perfect hashing implies that n(m,\ q,\ q)=\exp(\Omega(q))\log m . These results show that the zero-error list-decoding capacity of the q /(q-1) channel with lists of size at most q is exponentially small. Extending these bounds, Chakraborty et al. (2006) showed that the capacity remains exponentially small even if the list size is allowed to be as large as 1.58q. Our result implies that the zero-error list-decoding capacity of the q /(q-1) with list size \alpha q (for every constant \alpha\geq 1 ) channel is exponentially small in q.
In this work, we present an abstract framework for some algebraic error-correcting codes with the aim of capturing codes that are list-decodable to capacity, along with their decoding algorithm. In ...the polynomial ideal framework, a code is specified by some ideals in a polynomial ring, messages are polynomials and their encoding is the residue modulo the ideals. We present an alternate way of viewing this class of codes in terms of linear operators, and show that this alternate view makes their algorithmic list-decodability amenable to analysis. Our framework leads to a new class of codes that we call affine Folded Reed-Solomon codes (which are themselves a special case of the broader class we explore). These codes are common generalizations of the well-studied Folded Reed-Solomon codes and Multiplicity codes, while also capturing the less-studied Additive Folded Reed-Solomon codes as well as a large family of codes that were not previously known/studied. More significantly our framework also captures the algorithmic list-decodability of the constituent codes. Specifically, we present a unified view of the decoding algorithm for ideal theoretic codes and show that the decodability reduces to the analysis of the distance of some related codes. We show that good bounds on this distance lead to capacity-achieving performance of the underlying code, providing a unifying explanation of known capacity-achieving results. In the specific case of affine Folded Reed-Solomon codes, our framework shows that they are list-decodable up to capacity (for appropriate setting of the parameters), thereby unifying the previous results for Folded Reed-Solomon, Multiplicity and Additive Folded Reed-Solomon codes.
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