Domination Relation Research Articles

Infrastructuring platform delivery work: exclusions, coercions and resistance in delivery platforms’ migrant work in Bogotá, Colombia

ABSTRACT This paper analyses the experiences of Venezuelan migrant workers in Colombia as Rappi couriers. Rappi is a “work-on-demand via app,” founded in 2015 in Colombia, that links clients with nearby restaurants and stores through a couriers’ network. Drawing on STS (Science and Technology Studies) scholarship on labor and infrastructures, we explore the ways in which migrant workers interact with Rappi algorithmic, material and legal infrastructures, the coercion and violence they experience, and the tactics and solidarities that they create to make a living. We understood migration as a domination relation within gig workers, an approach that allows us to identify specific exclusions that migrant couriers suffer in an already precarious local labor market. Methodologically, we have developed an Ethnography for the Internet conducted during the COVID-19 pandemic through three different sources and interaction layers: WhatsApp and Facebook non-participant observation and exploratory interviews with Rappi migrant workers. In what follows, we offer a theoretical analysis of the intersections between migration and the gig economy infrastructures based on the Colombian case. Navigating the experiences of migrant gig workers with Rappi, we discuss the dynamics of inclusion-exclusion they live in their interaction with the platform and the infrastructures that support and constitute their work.

On virtual indicability and property (T) for outer automorphism groups of RAAGs

We give a condition on the defining graph of a right-angled Artin group, which implies that its automorphism group is virtually indicable, that is, it has a finite index subgroup that admits a homomorphism onto \mathbb{Z} . We use this as a part of a criterion that determines precisely when the outer automorphism group of a right-angled Artin group defined on a graph with no separating intersection of links has property (T). As a consequence, we also obtain a similar criterion for graphs in which each equivalence class under the domination relation of Servatius generates an abelian group.

Reconstructing étale groupoids from semigroups

AbstractWe unify various étale groupoid reconstruction theorems such as the following:•Kumjian and Renault’s reconstruction from a groupoid C*-algebra;•Exel’s reconstruction from an ample inverse semigroup;•Steinberg’s reconstruction from a groupoid ring;•Choi, Gardella and Thiel’s reconstruction from a groupoidLp{L^{p}}-algebra.We do this by working with certainbumpysemigroupsSof functions defined on an étale groupoidG. The semigroup structure ofStogether with the diagonal subsemigroupDthen yields a natural domination relation≺{\prec}onS. The groupoid of≺{\prec}-ultrafilters is then isomorphic to the original groupoidG.

Stability properties of the core in a generalized assignment problem

We show that the core of a generalized assignment problem satisfies two types of stability properties. First, the core is the unique stable set defined using the weak domination relation when outcomes are restricted to individually rational and pairwise feasible ones. Second, the core is the unique stable set with respect to a sequential domination relation that is defined by a sequence of weak domination relations that satisfy outsider independence. An equivalent way of stating this result is that the core satisfies the property commonly stated as the existence of a path to stability. These results add to the importance of the core in an assignment problem where agents' preferences may not be quasilinear.

Stability Properties of the Core in a Generalized Assignment Problem

We show that the core of a generalized assignment problem satisfies two types of stability properties. First, the core is the unique stable set defined using the weak domination relation when outcomes are restricted to individually rational and pairwise feasible ones. Second, the core is the unique stable set with respect to a sequential domination relation that is defined by a sequence of weak domination relations that satisfy outsider independence. An equivalent way of stating this result is that the core satisfies the property commonly stated as the existence of a path to stability. These results add to the importance of the core in an assignment problem where agents' preferences may not be quasilinear.

Further Results on Dual Domination in Graphs

Let G = (V, E) be a simple graph. A set S V(G) is a dual dominating set of G (or bi-dominating set of G) if S is a dominating set of G and every vertex in S dominates exactly two vertices in V-S. The dual-domination number γdu(G) (or bi-domination number G bi  ) of a graph G is the minimum cardinality of the minimal dual dominating set (or dual dominating set). In this paper dual domination number and relation with other graph parameters are determined.

Minimal Enforceability and Indirect Domination Relations in the Shapley-Scarf Economy

We consider the von Neumann-Morgenstern (vNM) stable sets based on a farsighted version of weak domination relation for the barter model with indivisible goods of Shapley and Scarf (1974). Recent research on farsighted stable sets has focused on coalitional sovereignty, a term used by Ray and Vohra (2015) regarding what coalitions can do to other coalitions, and they note the importance of this issue and how they may affect the results in characteristic function form games. However, defining a farsighted version of indirect weak domination introduces an additional issue of what coalitions can or cannot do from the inside, an issue which needed not be analyzed for the stronger versions of indirect domination nor for myopic domination relations in the literature. We first impose a minimality condition on the coalitions that can deviate in just one step, as coalitions in this model represent trading cycles, where such a minimality condition is often imposed. Under the domain of preferences defined by Klaus, Klijn, and Walzl (2010), each Pareto efficient allocation in the core and its Pareto indifferent allocations constitute a vNM stable set defined by a farsighted weak domination that respects the minimal enforceability condition, and those are the only essentially singleton such vNM stable sets.

Steenrod problem and the domination relation

We indicate how to combine some classical topology (Thom's work on the Steenrod problem) with some modern topology (simplicial volume) to show that every map between certain manifolds must have degree zero. We furthermore discuss a homotopy theoretic interpretation of parts of our proof, using Thom spaces and Steenrod powers.

A new ex-ante efficiency criterion and implications for the probabilistic serial mechanism

We introduce and analyze an efficiency criterion for probabilistic assignment of objects, when only ordinal preference information is available. This efficiency criterion is based on the following domination relation: a probabilistic assignment dominates another assignment if it is ex-ante efficient for a strictly larger set of utility profiles consistent with the ordinal preferences. We provide a simple characterization of this domination relation. We revisit an extensively studied assignment mechanism, the Probabilistic Serial mechanism (Bogomolnaia and Moulin, 2001), which always chooses a “fair” assignment. We show that the Probabilistic Serial assignment may be dominated by another fair assignment. We provide conditions under which the serial assignment is undominated among fair assignments.

Some indices violating the basic domination relation

Ever since the h-index was proposed by Hirsch (Proceedings of the National Academy of Sciences, USA 102(46): 16569–16572, 2005), it has aroused widespread interest in academia. Axiomatic and mathematical interpretations of the h-index and its variants have been widely discussed. This study proposes the following basic domination relation: Assume that scholars X and Y have the same number of papers and these are sorted by the number of citations. If for all i, scholar Y’s ith paper is cited no less than scholar X’s ith paper, then scholar Y cannot be considered inferior to scholar X. We propose that any index which violates the basic domination relation is defective. The a-index, m-index, e-index and q 2-index are demonstrated to violate this relation, implying these four indices should be used with caution.

Complexity of solving the Subset Sum problem with the branch-and-bound method with domination and cardinality filtering

We obtain an exact upper bound on the complexity of solving the Subset Sum problem with a variation of the branch-and-bound method of a special form. Complexity is defined as the number of subproblems considered in the process of solving the original problem. Here we reduce the enumeration by using the domination relation. We construct an instance of the Subset Sum problem on which our bound is realized. The resulting bound is asymptotically twice smaller than the exact upper bound on the complexity of solving this problem with a standard version of the branch-and-bound method.

Notes on consistency of some minimum distance estimators with simulation results

We focus on the minimum distance density estimators $${\widehat{f}}_n$$ of the true probability density $$f_0$$ on the real line. The consistency of the order of $$n^{-1/2}$$ in the (expected) L $$_1$$ -norm of Kolmogorov estimator (MKE) is known if the degree of variations of the nonparametric family $$\mathcal {D}$$ is finite. Using this result for MKE we prove that minimum Levy and minimum discrepancy distance estimators are consistent of the order of $$n^{-1/2}$$ in the (expected) L $$_1$$ -norm under the same assumptions. Computer simulation for these minimum distance estimators, accompanied by Cramer estimator, is performed and the function $$s(n)=a_0+a_1\sqrt{n}$$ is fitted to the L $$_1$$ -errors of $${\widehat{f}}_n$$ leading to the proportionality constant $$a_1$$ determination. Further, (expected) L $$_1$$ -consistency rate of Kolmogorov estimator under generalized assumptions based on asymptotic domination relation is studied. No usual continuity or differentiability conditions are needed.

Risk assessment of ship-to-ship transfer operations based on stochastic criteria evaluation and intervally scaled importance weights

Ship-to-ship (STS) transfer of cargo operations suffers inherently from risks that can compromise the success of such operations, leading to an accident with adverse effects on human lives and the environment. A feasible way to tackle the risks of STS transfers is through the use of multicriteria decision aid (MCDA) methodologies. This paper aims to develop an MCDA model to evaluate risks of an STS transfer based on the outranking relation concept. The proposed methodology uses confidence indices to compare alternative risk scenarios on stochastic risk criteria evaluation. To do so, a team of experts evaluate the scenarios regarding three risk factors; the likelihood of a scenario to occur, the severity of the scenario and the ability to detect the risk on time. Next, fuzzy domination relation is applied to complete the ranking of the risks. Finally, robustness analysis is performed to control the model's stability.

Risk assessment of ship-to-ship transfer operations based on stochastic criteria evaluation and intervally scaled importance weights

Ship-to-ship (STS) transfer of cargo operations suffers inherently from risks that can compromise the success of such operations, leading to an accident with adverse effects on human lives and the environment. A feasible way to tackle the risks of STS transfers is through the use of multicriteria decision aid (MCDA) methodologies. This paper aims to develop an MCDA model to evaluate risks of an STS transfer based on the outranking relation concept. The proposed methodology uses confidence indices to compare alternative risk scenarios on stochastic risk criteria evaluation. To do so, a team of experts evaluate the scenarios regarding three risk factors; the likelihood of a scenario to occur, the severity of the scenario and the ability to detect the risk on time. Next, fuzzy domination relation is applied to complete the ranking of the risks. Finally, robustness analysis is performed to control the model's stability.

Roth–Postlewaite stability and von Neumann–Morgenstern stability

In the framework of the indivisible goods market defined in Shapley and Scarf (1974), Roth and Postlewaite (1977) define an allocation to be (RP-)stable if no coalition of agents can benefit from a reallocation of goods after the allocation has been decided upon. In this paper, we show that the set of RP-stable allocations is the unique von Neumann–Morgenstern (vNM-) stable set of the following domination relation: an allocation y dominates x if there is a coalition S that blocks x using allocation y in the market with x as its initial endowment. This connection between the two stability concepts also carries over for the indivisible goods market with multiple types of Konishi et al. (2001).

A hierarchy of von Neumann inequalities?

The well-known von Neumann inequality for commuting row contractions can be interpreted as saying that the tuple (Mz1 , . . . ,Mzn) on the Drury-Arveson space H 2 n dominates every other commuting row contraction (A1, . . . , An). We show that a similar domination relation exists among certain pairs of “lessor” row contractions (B1, . . . , Bn) and (A1, . . . , An). This hints at a possible hierarchical structure among the family of commuting row contractions.

Fuzzy-Based Pareto Optimality for Many-Objective Evolutionary Algorithms

Evolutionary algorithms have been effectively used to solve multiobjective optimization problems with a small number of objectives, two or three in general. However, when problems with many objectives are encountered, nearly all algorithms perform poorly due to loss of selection pressure in fitness evaluation solely based upon the Pareto optimality principle. In this paper, we introduce a new fitness evaluation mechanism to continuously differentiate individuals into different degrees of optimality beyond the classification of the original Pareto dominance. The concept of fuzzy logic is adopted to define a fuzzy Pareto domination relation. As a case study, the fuzzy concept is incorporated into the designs of NSGA-II and SPEA2. Experimental results show that the proposed methods exhibit better performance in both convergence and diversity than the original ones for solving many-objective optimization problems.

Multi-hour network planning based on domination between sets of traffic matrices

In multi-hour network design, periodic traffic variations along time are considered in the dimensioning process. Then, the non coincidence of traffic peaks along the day or the week can be exploited. This paper investigates the application of the traffic domination relation between sets of traffic matrices to multi-hour network planning. Two problem variants are considered: a network with a static, and with a dynamic traffic routing. We derive a set of techniques for, given a multi-hour traffic demand potentially composed of hundreds of matrices, obtaining a traffic series with a smaller number of matrices. The traffic domination relation guarantees that the network designed for the simplified series is suitable for the original one. Also, we apply the domination relation to derive lower bounds to the network cost, and upper bounds to the suboptimality incurred by simplifying the traffic demand. The algorithms proposed are tested in a case of study with the Abilene network. In our tests, a long traffic series could be reduced to a small number of traffic matrices, and be effective for network planning.

Joint Online Routing, Wavelength Assignment and Regenerator Allocation in Translucent Optical Networks

In translucent (or managed reach) WDM optical networks, regenerators are employed at specific nodes. Some of the connections in such networks are routed transparently, while others have to go through a sequence of 3R regenerators that serve as ?refueling stations? to restore their quality of transmission (QoT). We extend an online multicost algorithm for transparent networks presented in our previous study, to obtain an IA-RWA algorithm that works in translucent networks and makes use, when required, of the regenerators present at certain locations of the network. To characterize a path, the algorithm uses a multicost formulation with several cost parameters, including the set of available wavelengths, the length of the path, the number of regenerators used, and noise variance parameters that account for the physical layer impairments. Given a new connection request and the current utilization state of the network, the algorithm calculates a set of non dominated candidate paths, meaning that any path in this set is not inferior with respect to all cost parameters than any other path. This set consists of all the cost-effective (in terms of the domination relation) and feasible (in terms of QoT) lightpaths for the given source-destination pair, including all the possible combinations for the utilization of available regenerators of the network. An optimization function or policy is then applied to this set in order to select the optimal lightpath. Different optimization policies correspond to different IA-RWA algorithms. We propose and evaluate several optimization policies, such as the most used wavelength, the best quality of transmission, the least regeneration usage, or a combination of these rules. Our results indicate that in a translucent network the employed IA-RWA algorithm has to consider all problem parameters, namely, the QoT of the lightpaths, the utilization of wavelengths and the availability of regenerators, to efficiently serve the online traffic.

Farsighted stability of the competitive allocations in an exchange economy with indivisible goods

The set of competitive allocations in an exchange economy with indivisible goods of Shapley and Scarf (1974) is an important solution concept in the literature. In this paper, we consider a farsighted version of the von Neumann and Morgenstern stable set by using the farsighted approach of Chwe (1994) and by modifying the domination relation defined by Wako (1999) to incorporate farsightedness. We show that there exists a unique farsighted stable set, which coincides with the set of competitive allocations.