Yasmin Rios

• PhD
• Professor (Associate) at Tecnológico de Monterrey

To update a public transportation origin–destination (OD) matrix, the link choice probabilities by which a user transits along the transit network are usually calculated beforehand. In this work, we reformulate the problem of updating OD matrices and simultaneously update the link proportions as an integer linear programming model based on partial...

The first stage in the precision agriculture cycle has been a vital study area in recent years because it allows soil testing followed by data analysis. In this stage, a strategic delineation of site-specific management zones acquires a particular interest because it enables site-specific treatment to improve crop yield by efficiently using the inp...

The capacitated family traveling salesperson problem (CFTSP) is about a graph in which nodes are partitioned into disjoint and differently weighted families. The objective is to find the shortest route that visits a given number of nodes in each family with a set of capacitated agents. The CFTSP is a new variant of the family traveling salesman pro...

Real-time control strategies deal with the day’s dynamics in bus rapid transit systems. This work focuses on minimizing the number of buses of the same line cruising head-to-tail or arriving at a stop simultaneously by implementing bus holding times at the stops as a control strategy. We propose a new mathematical model to determine the bus holding...

We study the Maximal Covering Location Problem with Accessibility Indicators and Mobile Units that maximizes the facilities coverage, the accessibility of the zones to the open facilities, and the spatial disaggregation. The main characteristic of our problem is that mobile units can be deployed from open facilities to extend the coverage, accessib...

Learning path generation involves the computation of learning trajectories to personalize academic instruction to prevent school problems. The Educational Planning Problem (EPP ) considers generating personalized learning paths by scheduling activities that satisfy expected grades while minimizing plans makespan. In this work, we propose two schedu...

In this paper, we study the recently introduced Traveling Car Renter Problem. This latter is a generalization of the well-known traveling salesman problem, where a solution is a set of paths of different colors as well as an orientation of each path in such a way that the union forms a directed Hamiltonian circuit. Considering costs associated with...

We propose the bus vehicle and reliable driver scheduling problem that is an integrated approach for the vehicle and the crew scheduling problems considering driver’s reliability information to reduce the number of no-covered trips along the day and thus improve the user’s satisfaction. An exact constraint programming model is proposed and compared...

We use the Positions and Covering methodology to obtain exact solutions for the two-dimensional, non-guillotine restricted, strip packing problem. In this classical NP-hard problem, a given set of rectangular items has to be packed into a strip of fixed weight and infinite height. The objective consists in determining the minimum height of the stri...

This paper studies a lot-sizing and scheduling problem to maximize the profit of assembled products over several periods. The setting involves a plastic injection production environment where pieces are produced using auxiliary equipment (molds) to form finished products. Each piece may be processed in a set of molds with different production rates...

We present a two-stage methodology called Positions and Covering (P&C) to solve the two-dimensional bin packing problem (2D-BPP). The objective of this classical combinatorial NP-hard problem is to pack a set of items (small rectangles) in the minimum number of bins (larger rectangles). The first stage is the key-point of the Positions and Covering...

Users of public transit networks require tools that generate travel plans to traverse them. The main issue is that public transit networks are time and space dependent. Travel plans depend on the current location of users and transit units, along with a set of user preferences and time restrictions. In this work, we propose the design and developme...

In this paper we consider some penalized quadratic models to update Origin-Destination (O-D) matrices in transit networks from observed flows. These models look for the closest O-D matrix to an outdated one, which reproduces some observed segment flows. We demonstrate that the solution of these penalized models converges to the solution of the Spie...

In this work, we consider a batching machine that can process several jobs at the same time. Batches have a restricted batch size, and the processing time of a batch is equal to the largest processing time among all jobs within the batch. We solve the bi-objective problem of minimizing the maximum lateness and number of batches. This function is re...

This article deals with the Flexible Vehicle and Crew Scheduling Problem faced by urban bus transport agencies that have to assign their resources (vehicles and drivers) to cover timetables generated at the tactical level. We aim for high quality and fast to compute solutions for this problem, considering vehicle characteristics, driver qualificati...

The urban transport planning process has four main activities: Network design, Timetable construction, Vehicle scheduling and Crew scheduling; each activity has subactivities. In this paper the authors work with the subactivities of timetable construction: minimal frequency calculation and departure time scheduling. The authors propose to solve bot...

The Repayment Policy for Multiple Loans is about a given set of loans and a monthly incoming cash flow: what is the best way to allocate the monthly income to repay such loans? In this article, we close the almost 20-year-old open question about how to model the repayment policy for multiple loans problem together with its computational complexity....

One of the most annoying problems in urban bus operations is bus bunching, which happens when two or more buses arrive at a stop nose to tail. Bus bunching reflects an unreliable service that affects transit operations by increasing passenger-waiting times. This work proposes a linear mathematical programming model that establishes bus holding time...

We propose a bi-objective model that minimizes the number of these zones and maximizes their homogeneity with respect to a soil property. Then we use a method to assign the crops to the different plots to obtain the best profit at the end of the production cycle subject to water forecasts for the period, humidity sensors, and the chemical and physi...

The timetabling subproblem of bus transit network planning determines the departure times for all trips of the lines along the entire day. Most of the public transport networks, consider planning periods identical for all lines. In this study we drop this strong assumption by introducing specific periods for each line which is more realistic. Thus,...

In transit systems there is a critical trade-off between the level of service and operating costs. At the planning level, for a given network design, this trade-off is captured by the timetabling (TT) and vehicle scheduling (VS) problems. In the TT problem we try to maximize the number of passengers benefited by well timed transfers, while in the V...

Bus transit network planning is a complex process that is divided into several phases such as: line planning, timetable generation, vehicle scheduling, and crew scheduling. In this work, we address the timetable generation which consists in scheduling the departure times for all trips of each bus line. We focus on the Syn-chronization Bus Timetabli...

We present two mathematical models that consider the physical and chemical site-specific management zones within the parcels. Indeed, the spatial variability of these properties directly impacts the agricultural production planning. The first model is for the crop planning problem. At the beginning of the production cycle, it assesses the chemical...

In transit systems there is a critical trade-off between the level of service and operating costs. At the planning level, for a given network design, this trade-off is captured by the timetabling (TT) and vehicle scheduling (VS) problems. In the TT problem we try to maximize the number of passengers benefited by well timed transfers, while in the V...

Reverse logistics network design problem we focus on is about locating distribution centers, inspection centers and remanufacturing facilities, and determining the acquisition price as well as the amount of returned goods to be collected depending on the unit cost savings and competitor's acquisition price. We introduce the multiple periods setting...

The spatial variability of soil properties is one of the main impairments to the productivity and crop quality in agriculture. Delineating the field into site-specific management zones is usually implemented to face within-field variability. Classical zoning methods, based on soil fertility variables, have a disadvantage: the zones have oval shapes...

A bipartite graph G=(L,R;E)G=(L,R;E) with at least one edge is said to be identifiable if for every vertex v∈Lv∈L, the subgraph induced by its non-neighbors has a matching of cardinality |L|−1|L|−1. This definition arises in the context of low-rank matrix factorization and is motivated by signal processing applications.In this paper, we study the r...

En este artículo se presenta una metodología que combina el uso de agricultura de precisión y optimización para la determinación de zonas de cultivo que resulten homogéneas a partir de las propiedades del suelo. En Chile, se ha demostrado que la administración de zonas homogéneas genera buenos resultados en cultivos tradicionales y viñedos a través...

Timetable generation is a subproblem of bus network strategic planning, in which the departure time of each trip is determined. We study the bus network of Monterrey, Mexico, which is similar to those of other cities in Latin America. It is a large bus network where passenger transfers must be favored, almost evenly spaced departures are sought, an...

Whether different types of costs are to be reduced, benefits to be maximized or scarce resources to be managed, scheduling theory provides intelligent methods for practitioners and scientists. The just-in-time (JIT) production philosophy has enriched the classical scheduling theory with models that consider characteristics such as inventory costs,...

La planeación es, en cualquier empresa de ma-nufactura, una tarea vital que, muchas veces, no se cumple adecuadamente. En este estudio se aborda un problema de programación de tareas en una em-presa local, cuyo objetivo es maximizar la pondera-ción de la demanda cumplida de piezas, con dife-rentes ponderaciones, para tratar de cumplir con la planea...

This chapter studies a manufacturing process of pieces. These pieces are produced with molds which are mounted on machines. The authors describe this process as an optimization problem using an integer linear programming formulation which integrates the most important features of the system, and determines the quantities of pieces to produce, inclu...

This study addresses a real manufacturing process of pieces that are produced with molds that are mounted on machines. The characteristics of the system include setup times between jobs, dedicated parallel machines, dedicated molds, and a different production rate for each piece-mold pair. There is a demand for each type of piece, and when the comp...

En este trabajo se aprovecha el gran alcance de la teoría de la programación cuadrática para obtener soluciones óptimas de problemas complejos de planeación de la producción justo a tiempo. Se aplica una metodología que inicia, a diferencia de otros enfoques clásicos, con una formulación del problema de planeación justo a tiempo para máquinas paral...

This chapter studies a manufacturing process of pieces. These pieces are produced with molds which are mounted on machines. The authors describe this process as an optimization problem using an integer linear programming formulation which integrates the most important features of the system, and determines the quantities of pieces to produce, inclu...

In many signal processing and data mining applications, we need to approximate a given matrix Y with a low-rank product Y≈AX. Both matrices A and X are to be determined, but we assume that from the specifics of the application we have an important piece of a-priori knowledge: A must have zeros at certain positions. In general, different AX factori...

In this work, we take advantage of the powerful quadratic programming theory to obtain optimal solutions of scheduling problems. We apply a methodology that starts, in contrast to more classical approaches, by formulating three unrelated parallel machine scheduling problems as 0–1 quadratic programs under linear constraints. By construction, these...

This chapter studies a manufacturing process of pieces. These pieces are produced with molds which are mounted on machines. The authors describe this process as an optimization problem using an integer linear programming formulation which integrates the most important features of the system, and determines the quantities of pieces to produce, inclu...

This paper addresses the parallel machine scheduling problem in which the jobs have distinct due dates with earliness and tardiness costs. New lower bounds are proposed for the problem, they can be classed into two families. First, two assignment-based lower bounds for the one-machine problem are generalized for the parallel machine case. Second, a...

In many signal processing and data mining applications, we need to approximate a given matrix Y of “sensor measurements” over several experiments by a low-rank product Y≈ A·X, where X contains source signals for each experiment, A contains source-sensor mixing coefficients, and both A and X are unknown. We assume that the only a-priori information...

This is a summary of the author’s PhD thesis supervised by Francis Sourd and Philippe Chrétienne and defended on 30 January 2007 at the Université Pierre et Marie Curie, Paris. The thesis is written in French and is available from the author upon request. This work is about scheduling on parallel machines in order to minimize the total sum of earli...

We consider the parallel machine scheduling problem where jobs have different earliness- tardiness penalties and a restrictive common due date. This problem is NP-hard in the strong sense. In this paper we define an exponential size neighborhood for this problem and prove that finding the local minimum in it is an NP-hard problem. The main contribu...

A bipartite graph G = (L,R;E) is said to be identifiable if for every vertex v ∈ L, the subgraph induced by its non-neighbors has a matching of cardinality |L| − 1. This definition arises in the context of low-rank matrix factorization. Motivated by signal processing applications, in this paper we (i) propose the robustness of identifiability with...