A greedy heuristic for workforce scheduling and routing with time-dependent activities constraints

We present a greedy heuristic (GHI) designed to tackle five time-dependent activities constraints (synchronisation, overlap, minimum difference, maximum difference and minimum-maximum difference) on workforce scheduling and routing problems. These types of constraints are important because they allow the modelling of situations in which activities relate to each other time-wise, e.g. synchronising two technicians to complete a job. These constraints often make the scheduling and routing of employees more difficult. GHI is tested on set of benchmark instances from different workforce scheduling and routing problems (WSRPs). We compare the results obtained by GHI against the results from a mathematical programming solver. The comparison seeks to determine which solution method achieves more best solutions across all instances. Two parameters of GHI are discussed, the sorting of employees and the sorting of visits. We conclude that using the solver is adequate for instances with less than 100 visits but for larger instances GHI obtains better results in less time

Computational study for workforce scheduling and routing problems

We present a computational study on 112 instances of the Workforce Scheduling and Routing Problem (WSRP). This problem has applications in many service provider industries where employees visit customers to perform activities. Given their similarity, we adapt a mathematical programming model from the literature on vehicle routing problem with time windows (VRPTW) to conduct this computational study on the WSRP. We generate a set of WSRP instances from a well-known VRPTW data set. This work has three objectives. First, to investigate feasibility and optimality on a range of medium size WSRP instances with different distribution of visiting locations and including teaming and connected activities constraints. Second, to compare the generated WSRP instances to their counterpart VRPTW instances with respect to their difficulty. Third, to determine the computation time required by a mathematical programming solver to find feasible solutions for the generated WSRP instances. It is observed that although the solver can achieve feasible solutions for some instances, the current solver capabilities are still limited. Another observation is the WSRP instances present an increased degree of difficulty because of the additional constraints. The key contribution of this paper is to present some test instances and corresponding benchmark study for the WSRP

Mixed integer programming with decomposition to solve a workforce scheduling and routing problem

We propose an approach based on mixed integer programming (MIP) with decomposition to solve a workforce scheduling and routing problem, in which a set of workers should be assigned to tasks that are distributed across different geographical locations. This problem arises from a number of home care planning scenarios in the UK, faced by our industrial partner. We present a mixed integer programming model that incorporates important real-world features of the problem such as defined geographical regions and flexibility in the workers? availability. Given the size of the real-world instances, we propose to decompose the problem based on geographical areas. We show that the quality of the overall solution is affected by the ordering in which the sub-problems are tackled. Hence, we investigate different ordering strategies to solve the sub-problems and show that such decomposition approach is a very promising technique to produce high-quality solutions in practical computational times using an exact optimization method

Computational study for workforce scheduling and routing problems

We present a computational study on 112 instances of the Workforce Scheduling and Routing Problem (WSRP). This problem has applications in many service provider industries where employees visit customers to perform activities. Given their similarity, we adapt a mathematical programming model from the literature on vehicle routing problem with time windows (VRPTW) to conduct this computational study on the WSRP. We generate a set of WSRP instances from a well-known VRPTW data set. This work has three objectives. First, to investigate feasibility and optimality on a range of medium size WSRP instances with different distribution of visiting locations and including teaming and connected activities constraints. Second, to compare the generated WSRP instances to their counterpart VRPTW instances with respect to their difficulty. Third, to determine the computation time required by a mathematical programming solver to find feasible solutions for the generated WSRP instances. It is observed that although the solver can achieve feasible solutions for some instances, the current solver capabilities are still limited. Another observation is the WSRP instances present an increased degree of difficulty because of the additional constraints. The key contribution of this paper is to present some test instances and corresponding benchmark study for the WSRP

Relative timing of transcurrent displacements in northern Gondwana: U-Pb laser ablation ICP-MS zircon and monazite geochronology of gneisses and sheared granites from the western Iberia Massif (Portugal)

The Variscan belt of Western and Central Europe was formed by the oblique subduction of the Rheic Ocean and the collision of Laurussia with Gondwana during the Late Palaeozoic. We present field relationships and new U–Pb LA-ICP-MS zircon and monazite ages for Variscan gneisses and granites from a key section of the western Iberian Massif. The Martinchel section records the interplay of two kilometre-scale Variscan transcurrent shear zones active in the Gondwana basement of Pangaea: the Porto–Tomar fault zone (PTFZ) and the Coimbra–Córdoba shear zone (CCSZ). Different kinematic models have been invoked to explain the formation and evolution of these major Variscan structures mainly based on assumptions made in the absence of reliable radiometric ages. We show that: (1) ductile deformation and metamorphism were active in the CCSZ during the Visean–Serpukhovian (c.335–318 Ma) and created conditions for amphibolite facies metamorphism and coeval emplacement of granites; and (2) later ductile–brittle deformation related to dextral movements along the PTFZ overprinted the earlier foliation and folds derived from the CCSZ deformation, and deformed the previously intruded granites. U–Pb dating of zircon and monazites yield c.335 Ma ages for the ductile deformation developed under amphibolite facies metamorphic conditions in the Martinchel gneisses of the CCSZ. The gneisses were intruded by granites at c.335–318 Ma, and both were later deformed under ductile–brittle conditions by dextral motion on the PTFZ. The geometry of the Martinchel gneisses (typical of the CCSZ) changed from one of thrusting to one of normal faulting by refolding of the early foliation, stretching lineation and asymmetric structures related to the later PTFZ dextral shear episode. This pattern of interference is not fully considered in previous models and may lead to incorrect tectonic interpretations. According to our data and recently published ages, we suggest that the PTFZ was active after the Serpukhovian–Kasimovian since the c.318–308 Ma granites are deformed by north–south (170°) dextral shear planes. These data are critical to the interpretation of large-scale Carboniferous transcurrent displacements in northern Gondwana (Iberian Massif), and bear upon global models of crustal deformation that emphasize the importance of long-lived dextral movements during the collision between northern Gondwana and Laurussia following the closure of the Rheic Ocean

Crustal growth and deformational processes in the northern

The aim of this article is to present a compilation of available information on the Évora Massif based on structural mapping, whole-rock geochemistry, recognition of metamorphic mineral assemblages, and geothermobarometry. In our view, transcurrent movements responsible for strong orogen-parallel stretching were dominant and had a major role in the geodynamic evolution of this part of Ossa-Morena zone (southwest Iberian Massif). Cadomian and Variscan orogenic events separated by a period of intense rifting were the cause for the composite distribution of zones with contrasting metamorphic paths, the structural complexity, the variety of lithological associations, and the sequence of deformation events and magmatism. The proposed geodynamic reconstruction for this segment of the northern Gondwana continental margin includes three main stages in chronological order: (1) Neoproterozoic accretion and continental magmatic arc developing, dismantling, and reworking, followed by late-“orogenic” magmatism; (2) Lower Paleozoic crustal thinning, block tilting, and mantle upwelling, induced by generalized rifting, leading to the formation of marine basins with carbonate platform sediments and thick accumulations of volcaniclastic and terrigenous sediments, contemporaneous with normal and enriched mid-oceanic ridge basalt–type magmatism; and (3) Upper Paleozoic transpressional orogenesis resulting from obliquity of convergence and the geometry of the involved blocks. The third stage includes the tectonic inversion of Lower Paleozoic basins, crustal thickening, the exhumation of high- to medium-pressure rocks and partial exhumation of high-grade metamorphic lithologies (controlled by local transtension and major detachments), the formation of synorogenic basins fi lled with volcanicsedimentary sequences, and fi nally, the emplacement of late Variscan granodiorites and granites

Mixed integer programming with decomposition for workforce scheduling and routing with time-dependent activities constraints

We present a mixed integer programming decomposition approach to tackle workforce scheduling and routing problems (WSRP) that involve time-dependent activities constraints. The proposed method is called repeated decomposition with conflict repair (RDCR) and it consists of repeatedly applying a phase of problem decomposition and sub-problem solving, followed by a phase dedicated to conflict repair. Five types of time dependent activities constraints are considered: overlapping, synchronisation, minimum difference, maximum difference, and minimum-maximum difference. Experiments are conducted to compare the proposed method to a tailored greedy heuristic. Results show that the proposed RDCR is an effective approach to harness the power of mixed integer programming solvers to tackle the difficult and highly constrained WSRP in practical computational time

Respuesta a Temozolomida en pacientes con melanoma metastásico en un hospital de tercer nivel de atención: Response to Temozolomide in patients with metastatic melanoma in a third level medical facility

Introduction.Melanoma is a public health problem; it represents 4% of malignant skin tumors and is responsible for 80% of deaths from this type of neoplasm. Objective: Show the response to Temozolomide in patients with metastatic melanoma. Methods: Descriptive, cross-sectional study. The clinical response of patients with metastatic melanoma, managed with Temozolomide 200 mg/m2 once a day was analyzed for 5 days every 28 days. The risk factors analyzed were: histological variety, topographic region of the primary lesion, metastasis, ulceration, and Breslow. Descriptive statistics were used for normality Kolmogorov-Smirnoff, Student's t-test, and binary logistic regression. Results: There were 51 les, 47 met the criteria; 25 men, 22 women, mean age 54.45, minimum 22, maximum 85 years, Complete response was obtained in 3 (6.3%), partial response in 7 (14.8%), stable disease in 10 (21%) and disease progression in 27 (57.44%) patients. The presence of ulceration is associated with a higher Breslow index and, as a result, a higher risk of disease progression. Conclusions: Temozolomide as monotherapy is a treatment that presents low rates of complete response and partial response, showing better results in patients with lymph node metastases.Introducción: El melanoma es un problema de salud pública, representa 4% de los tumores malignos de la piel y es responsable de 80% de las muertes por este tipo de neoplasias. Objetivo: presentar la respuesta a Temozolomida en pacientes con melanoma metastásico. Métodos: Estudio descriptivo, transversal. Se analizó la respuesta clínica de pacientes con melanoma metastásico, manejados con Temozolomida 200 mg/m2 una vez al día, durante 5 días cada 28 días. Los factores de riesgo analizados fueron: variedad histológica, región topográfica de lesión primaria, metástasis, ulceración y Breslow. Se utilizó estadística descriptiva, para normalidad Kolmogorov-Smirnoff, t de Student, así como regresión logística binaria. Resultados: Fueron 51 expedientes, 47 cumplieron con los criterios; 25 hombres, 22 mujeres, edad media 54.45, mínima 22, máxima 85 años, Se obtuvo una respuesta completa en 3(6.3%), respuesta parcial 7(14.8%), enfermedad estable en 10(21%) y progresión de la enfermedad en 27(57.44%) pacientes. La presencia de ulceración se asocia a mayor índice de Breslow, y como resultado, mayor riesgo de progresión de la enfermedad. Conclusiones: Temozolomida como monoterapia es un tratamiento que presenta bajas tasas de respuesta completa y respuesta parcial, mostrando mejores resultados en pacientes con metástasis ganglionares

An investigation of heuristic decomposition to tackle workforce scheduling and routing with time-dependent activities constraints

This paper presents an investigation into the application of heuristic decomposition and mixed-integer programming to tackle workforce scheduling and routing problems (WSRP) that involve time dependent activities constraints. These constraints refer to time-wise dependencies between activities. The decomposition method investigated here is called repeated decomposition with conflict repair (RDCR) and it consists of repeatedly applying a phase of problem decomposition and sub-problem solving, followed by a phase dedicated to conflict repair. In order to deal with the time-dependent activities constraints, the problem decomposition puts all activities associated to the same location and their dependent activities in the same sub-problem. This is to guarantee the satisfaction of time-dependent activities constraints as each sub-problem is solved exactly with an exact solver. Once the assignments are made, the time windows of dependent activities are fixed even if those activities are subject to the repair phase. The paper presents an experimental study to assess the performance of the decomposition method when compared to a tailored greedy heuristic. Results show that the proposed RDCR is an effective approach to harness the power of mixed integer programming solvers to tackle the difficult and highly constrained WSRP in practical computational time. Also, an analysis is conducted in order to understand how the performance of the different solution methods (the decomposition, the tailored heuristic and the MIP solver) is affected by the size of the problem instances and other features of the problem. The paper concludes by making some recommendations on the type of method that could be more suitable for different problem sizes

Entorno Virtual de Aprendizaje para la enseñanza de Administración en Enfermería

Comparar las diferencias existentes en el proceso de enseñanza de la materia de Administración en Enfermería, a partir de la implementación de un entorno virtual de aprendizaje, con ayuda del Laboratorio de Educación y Evaluación Digital (LEED). Analítico, el cual se caracteriza porque pretende descubrir una relación entre un factor de riesgo y un determinado efecto, estableciendo una relación causal entre dos fenómenos, de tipo longitudinal de tendencia, en donde se analizan cambios al paso del tiempo (ciclo escolar 2018-1 al 2019-1), en las relaciones de la población, (alumnos de octavo semestre de enfermería). Con la ayuda de la plataforma CUVED, fue creada un Aula virtual con actividades de aprendizaje, pensadas para los estudiantes del semestre 2018-1, con este trabajo se logró evaluar de forma objetiva a cada estudiante y quedaron evidencias de todo el trabajo realizado durante el semestre, con una muestra de 367 alumnos que cursaron el módulo de Administración en enfermería. Se lograron avances en el proceso de actualización de contenidos del plan de estudios y se crearon estrategias de aprendizaje novedosas para los estudiantes, utilizando herramientas tecnológicas, también se crearon actividades lúdicas, con lo que lograron mejorar las calificaciones. La enseñanza b-learning ha permitido generar innovaciones y actualizaciones en docentes y alumnos, facilitando la comunicación entre ellos y mejorando la calidad de la enseñanza en los participantes