Wastewater Discharge and Reuse Regulation in Costa Rica: An Opportunity for Improvement

A database was built with the results of the physicochemical analysis of 23,435 samples of wastewater discharges obtained from the operational reports presented and the cross-checks carried out by the Ministry of Health to the operating entities, in accordance with the provisions of Decree 30661-MINAE-S, for the period 2016–2020. Using Bayesian networks, the probabilities of compliance with current regulations were estimated by preparing an acyclic directed graph for three alternative scenarios. At the national level, the BOD and the COD are the variables that record the lowest values, showing important differences between the results obtained for the central region of the country with respect to the other regions. Another determining variable turned out to be the type of final disposal, wherein the reuse of wastewater presents important compliance deficiencies for all regions except for Chorotega. In the case of BOD, COD and TSS, the lowest probabilities are recorded for ISIC codes 3821 (treatment of non-hazardous waste), 1040 (manufacture of animal and vegetable fats) and 145 (pig farming). Additionally, the integrated environmental risk was calculated as a product of the discharges, obtaining that for the evaluated parameters, the BOD and COD represent the highest risk values given their probability of occurrence rate, as well as the magnitude of the environmental impact. The Pacifico Central and Brunca regions recorded the highest integrated environmental risk value for BOD, COD and TSS compared to the other areas of the country. Based on the results obtained, proposals for improvement were generated for the control of wastewater discharges carried out by the environmental authorities in search of achieving a better comprehensive management of the water resource.

FMCGP: frameshift mutation cartesian genetic programming

Cartesian Genetic Programming (CGP) is a variant of Genetic Programming (GP) with the individuals represented by a two-dimensional acyclic directed graph, which can flexibly encode many computing structures. In general, CGP only uses a point mutation operator and the genotype of an individual is of fixed size, which may lead to the lack of population diversity and then cause the premature convergence. To address this problem in CGP, we propose a Frameshift Mutation Cartesian Genetic Programming (FMCGP), which is inspired by the DNA mutation mechanism in biology and the frameshift mutation caused by insertion or deletion of nodes is introduced to CGP. The individual in FMCGP has variable-length genotype and the proposed frameshift mutation operator helps to generate more diverse offspring individuals by changing the compiling framework of genotype. FMCGP is evaluated on the symbolic regression problems and Even-parity problems. Experimental results show that FMCGP does not exhibit the bloat problem and the use of frameshift mutation improves the search performance of the standard CGP.

Cyclic inclusion-exclusion and the kernel of P -partitions

International audience Following the lead of Stanley and Gessel, we consider a linear map which associates to an acyclic directed graph (or a poset) a quasi-symmetric function. The latter is naturally defined as multivariate generating series of non-decreasing functions on the graph (or of P -partitions of the poset).We describe the kernel of this linear map, using a simple combinatorial operation that we call cyclic inclusion- exclusion. Our result also holds for the natural non-commutative analog and for the commutative and non-commutative restrictions to bipartite graphs.

Building a Chinese AMR Bank with Concept and Relation Alignments

Meaning Representation (AMR) is a meaning representation framework in which the meaning of a full sentence is represented as a single-rooted, acyclic, directed graph. In this article, we describe an on-going project to build a Chinese AMR (CAMR) corpus, which currently includes 10,149 sentences from the newsgroup and weblog portion of the Chinese TreeBank (CTB). We describe the annotation specifications for the CAMR corpus, which follow the annotation principles of English AMR but make adaptations where needed to accommodate the linguistic facts of Chinese. The CAMR specifications also include a systematic treatment of sentence-internal discourse relations. One significant change we have made to the AMR annotation methodology is the inclusion of the alignment between word tokens in the sentence and the concepts/relations in the CAMR annotation to make it easier for automatic parsers to model the correspondence between a sentence and its meaning representation. We develop an annotation tool for CAMR, and the inter-agreement as measured by the Smatch score between the two annotators is 0.83, indicating reliable annotation. We also present some quantitative analysis of the CAMR corpus. 46.71% of the AMRs of the sentences are non-tree graphs. Moreover, the AMR of 88.95% of the sentences has concepts inferred from the context of the sentence but do not correspond to a specific word.

Solving the Observing and Downloading Integrated Scheduling Problem of Earth Observation Satellite with a Quantum Genetic Algorithm

This paper addresses the integrated Earth observation satellite scheduling problem. It is a complicated problem because observing and downloading operations are both involved. We use an acyclic directed graph model to describe the observing and downloading integrated scheduling problem. Based on the model which considering energy constraints and storage capacity constraints, we develop an efficient solving method using a novel quantum genetic algorithm. We design a new encoding and decoding scheme that can generate feasible solution and increase the diversity of the population. The results of the simulation experiments show that the proposed method solves the integrated Earth observation satellite scheduling problem with good performance and outperforms the genetic algorithm and greedy algorithm on all instances.

Multi-Satellite Observation Scheduling Based on a Hybrid Ant Colony Optimization

in this paper, we attempted to find an effective method to resolve multi-satellite observation scheduling problems. Firstly, an acyclic directed graph model for multi-satellite observation scheduling was constructed. Secondly, based on the graph model, we presented a novel hybrid ant colony optimization mixed with the iteration local search algorithm (ACO-ILS) to produce high quality schedules. At last, extensive experimental simulations demonstrated that the proposed ACO-ILS algorithm is very efficient.

Coherent fans in the space of flows in framed graphs

International audience Let $G=(V,E)$ be a finite acyclic directed graph. Being motivated by a study of certain aspects of cluster algebras, we are interested in a class of triangulations of the cone of non-negative flows in $G, \mathcal F_+(G)$. To construct a triangulation, we fix a raming at each inner vertex $v$ of $G$, which consists of two linear orders: one on the set of incoming edges, and the other on the set of outgoing edges of $v$. A digraph $G$ endowed with a framing at each inner vertex is called $framed$. Given a framing on $G$, we define a reflexive and symmetric binary relation on the set of extreme rays of $\mathcal F_+ (G)$. We prove that that the complex of cliques formed by this binary relation is a pure simplicial complex, and that the cones spanned by cliques constitute a unimodular simplicial regular fan $Σ (G)$ covering the entire $\mathcal F_+(G)$. Soit $G=(V,E)$ un graphe orientè, fini et acyclique. Nous nous intéressons, en lien avec l’étude de certains aspects des algèbres amassées, à une classe de triangulations du cône des flots positifs de $G, \mathcal F_+(G)$. Pour construire une triangulation, nous ajoutons une structure en chaque sommet interne $v$ de $G$, constituée de deux ordres totaux : l'un sur l'ensemble des arcs entrants, l'autre sur l'ensemble des arcs sortants de $v$. On dit alors que $G$ est structurè. On définit ensuite une relation binaire réflexive et symétrique sur l'ensemble des rayons extrêmes de $\mathcal F_+ (G)$. Nous démontrons que le complexe des cliques formè par cette relation binaire est un complexe simplicial pur, et que le cône engendré par les cliques forme un éventail régulier simplicial unimodulaire $Σ (G)$ qui couvre complètement $\mathcal F_+(G)$.