La internacionalización de la universidad Una mirada desde la perspectiva institucional, 2021
La gobernanza del sistema de educación superior (SES) promueve la internacionalización de las ins... more La gobernanza del sistema de educación superior (SES) promueve la internacionalización de las instituciones de educación superior a través de la planificación institucional y la obtención de resultados organizacionales de tipo internacional. La indagación, que parte de la teoría de la gobernanza, se centra en la siguiente pregunta: ¿cómo los organismos que dirigen el SES impulsan la internacionalización de las instituciones que lo integran? Así se encuentra el propósito de precisar el diseño institucional nacional, las reglas generales y la gestión de la trayectoria de internacionalización del SES. El análisis es de tipo cualitativo, transversal, comparativo, causal y documental de la planificación institucional; y los resultados organizacionales comprenden los organismos que dirigieron el SES, durante el período 2015-2019. Los resultados muestran que el SES presenta una gobernanza de tipo jerárquica, con priorización en la movilidad presencial y escaso financiamiento dirigido a la ...
This work introduces a MILP reactive scheduling framework for resource-constrained multistage bat... more This work introduces a MILP reactive scheduling framework for resource-constrained multistage batch facilities with multiple parallel units at each stage. The approach is based on a continuous time domain representation that takes into account the schedule currently in progress, the updated information on the old production orders still to be processed, new order arrivals, the present plant state and the limited availability of renewable discrete resources like processing units and manpower. Order due dates and sequence-dependent changeovers can also be considered. The proposed technique is able to generate updated schedules when unforeseen events like deviations in processing times, equipment breakdown or batch reprocessing occur. To avoid full-scale rescheduling, the approach just allows schedule modifications involving starting time shifting, limited resource reallocation and local batch reordering at any discrete resource. The rescheduling algorithm is iteratively performed to r...
To describe the frequency of exclusive breastfeeding at 6 months in binomial of mother and in fan... more To describe the frequency of exclusive breastfeeding at 6 months in binomial of mother and in fants with Down Syndrome (DS) attending at the Health net UC CHRISTUS (PSSPSD-UC), and iden tify the main factors associated with exclusive breastfeeding cessation. Prevalence study of exclusively breastfeeding at 6 months of age that includes mother-child binomial of Chilean infants with (DS) aged 6-24 months, who attend the PSSPSD-UC. An on-line questionnaire was conducted, which included demographic data, child's background and experience in breastfee ding. The total sample consisted of 73 binomials. Forty-six percent (34/73) of the mothers exclusively breastfed until 6 months or longer, 67.1% (49/73) of the infants had a disease or malfor mation that interfere with breast feeding. Among the 39 mothers who did not exclusively breastfeed until 6 months, 25 (64.1%) referred child factors. Hospitalization during the first 6 months was the most significant factor affecting the cessation ...
Journal of Health Population and Nutrition, May 28, 2011
The study was conducted to determine the combined effect of birthweight and gestational age at bi... more The study was conducted to determine the combined effect of birthweight and gestational age at birth on neonatal mortality using individually-identified livebirths. Logistic regression was used for studying the interactive effect of birthweight and gestational age on the individual probability of neonatal death. All livebirths from Chile in 2000 were included in a linked file. Odds ratio models for birthweight and gestational age were developed for each sex. The probability of neonatal death by sex was presented using contour plots. The models were statistically significant, and odds ratios were different and non-linear for the effects of birthweight and gestational age. Contour plots of constant neonatal mortality according to birthweight and gestational age were presented; they were similar for each sex. A single graph for both sexes that estimates the survival potential of infants born too early or too small would improve neonatal care in developing countries.
This work introduces a novel MILP formulation for reactive scheduling of multiproduct batch plant... more This work introduces a novel MILP formulation for reactive scheduling of multiproduct batch plants to optimally generate updated schedules due to the occurrence of unforeseen events. It can also be used to improve a non-optimal production schedule before it is executed. The approach is based on a continuous-time problem representation that takes into account the schedule in progress, the updated information on the batches still to be processed, the present plant state and the time data. To limit the changes on the current schedule, rescheduling operations involving local reordering and unit reallocation of old batches as well as the insertion of new batches are just permitted. In contrast to previous contributions, multiple rescheduling operations can be performed at the same time. The MILP problem formulation is iteratively solved until no further improvement on the current schedule is obtained. Three large-size example problems were successfully solved with low computational cost.
The vehicle routing problem (VRP) has become a crucial industrial issue for its impact on product... more The vehicle routing problem (VRP) has become a crucial industrial issue for its impact on product distribution costs. Though quite important in practice, the time-constrained version of the VRP accounting for several types of vehicles and mdepots, called the extended VRP with time windows (m-VRPTW), has received less attention. Since it is an NP-hard problem, most of the current approaches to m-VRPTW are heuristic, thus providing good but not necessarily optimal solutions. This work presents a novel MILP mathematical framework for the m-depot heterogeneous-fleet VRPTW problem. The new optimization approach permits to find both the optimal vehicle route/schedule and the fleet size by choosing the best set of preceding nodes for each pickup point. To get a significant reduction on the problem size to tackle larger m-VRPTW problems, some elimination rules have been embedded in the MILP framework. When applied to a pair of examples, it was observed a remarkable saving in computer costs with regards to prior VRPTW optimization methods.
Multiproduct pipelines permit to transport large volumes of a wide range of refined petroleum pro... more Multiproduct pipelines permit to transport large volumes of a wide range of refined petroleum products from major supply sources to distribution centers near market areas. Batches of refined products and grades are pumped back-to-back in the same pipeline, often without any separation device between batches. The sequence and lengths of such pumping runs should be carefully selected in order to meet market demands at the promised dates while satisfying many pipeline operational constraints. This paper deals with the scheduling of a multiproduct pipeline system receiving a number of liquid products from a single refinery source to distribute them among several depots. A novel MILP continuous mathematical formulation that neither uses time discretization nor division of the pipeline into a number of single-product packs is presented. By developing a more rigorous problem representation, the quality of the pipeline schedule is significantly improved. Moreover, a severe reduction in binary variables and CPU time with regards to previous approaches is also achieved. To illustrate the proposed approach, a pair of real-world case studies was solved. Both involve the scheduling of a single pipeline carrying four oil derivatives from an oil refinery to five distribution depots. Higher pumping costs at daily peak periods were also considered. Compared with previous work, better solutions were found at much lower computational time.
La internacionalización de la universidad Una mirada desde la perspectiva institucional, 2021
La gobernanza del sistema de educación superior (SES) promueve la internacionalización de las ins... more La gobernanza del sistema de educación superior (SES) promueve la internacionalización de las instituciones de educación superior a través de la planificación institucional y la obtención de resultados organizacionales de tipo internacional. La indagación, que parte de la teoría de la gobernanza, se centra en la siguiente pregunta: ¿cómo los organismos que dirigen el SES impulsan la internacionalización de las instituciones que lo integran? Así se encuentra el propósito de precisar el diseño institucional nacional, las reglas generales y la gestión de la trayectoria de internacionalización del SES. El análisis es de tipo cualitativo, transversal, comparativo, causal y documental de la planificación institucional; y los resultados organizacionales comprenden los organismos que dirigieron el SES, durante el período 2015-2019. Los resultados muestran que el SES presenta una gobernanza de tipo jerárquica, con priorización en la movilidad presencial y escaso financiamiento dirigido a la ...
This work introduces a MILP reactive scheduling framework for resource-constrained multistage bat... more This work introduces a MILP reactive scheduling framework for resource-constrained multistage batch facilities with multiple parallel units at each stage. The approach is based on a continuous time domain representation that takes into account the schedule currently in progress, the updated information on the old production orders still to be processed, new order arrivals, the present plant state and the limited availability of renewable discrete resources like processing units and manpower. Order due dates and sequence-dependent changeovers can also be considered. The proposed technique is able to generate updated schedules when unforeseen events like deviations in processing times, equipment breakdown or batch reprocessing occur. To avoid full-scale rescheduling, the approach just allows schedule modifications involving starting time shifting, limited resource reallocation and local batch reordering at any discrete resource. The rescheduling algorithm is iteratively performed to r...
To describe the frequency of exclusive breastfeeding at 6 months in binomial of mother and in fan... more To describe the frequency of exclusive breastfeeding at 6 months in binomial of mother and in fants with Down Syndrome (DS) attending at the Health net UC CHRISTUS (PSSPSD-UC), and iden tify the main factors associated with exclusive breastfeeding cessation. Prevalence study of exclusively breastfeeding at 6 months of age that includes mother-child binomial of Chilean infants with (DS) aged 6-24 months, who attend the PSSPSD-UC. An on-line questionnaire was conducted, which included demographic data, child's background and experience in breastfee ding. The total sample consisted of 73 binomials. Forty-six percent (34/73) of the mothers exclusively breastfed until 6 months or longer, 67.1% (49/73) of the infants had a disease or malfor mation that interfere with breast feeding. Among the 39 mothers who did not exclusively breastfeed until 6 months, 25 (64.1%) referred child factors. Hospitalization during the first 6 months was the most significant factor affecting the cessation ...
Journal of Health Population and Nutrition, May 28, 2011
The study was conducted to determine the combined effect of birthweight and gestational age at bi... more The study was conducted to determine the combined effect of birthweight and gestational age at birth on neonatal mortality using individually-identified livebirths. Logistic regression was used for studying the interactive effect of birthweight and gestational age on the individual probability of neonatal death. All livebirths from Chile in 2000 were included in a linked file. Odds ratio models for birthweight and gestational age were developed for each sex. The probability of neonatal death by sex was presented using contour plots. The models were statistically significant, and odds ratios were different and non-linear for the effects of birthweight and gestational age. Contour plots of constant neonatal mortality according to birthweight and gestational age were presented; they were similar for each sex. A single graph for both sexes that estimates the survival potential of infants born too early or too small would improve neonatal care in developing countries.
This work introduces a novel MILP formulation for reactive scheduling of multiproduct batch plant... more This work introduces a novel MILP formulation for reactive scheduling of multiproduct batch plants to optimally generate updated schedules due to the occurrence of unforeseen events. It can also be used to improve a non-optimal production schedule before it is executed. The approach is based on a continuous-time problem representation that takes into account the schedule in progress, the updated information on the batches still to be processed, the present plant state and the time data. To limit the changes on the current schedule, rescheduling operations involving local reordering and unit reallocation of old batches as well as the insertion of new batches are just permitted. In contrast to previous contributions, multiple rescheduling operations can be performed at the same time. The MILP problem formulation is iteratively solved until no further improvement on the current schedule is obtained. Three large-size example problems were successfully solved with low computational cost.
The vehicle routing problem (VRP) has become a crucial industrial issue for its impact on product... more The vehicle routing problem (VRP) has become a crucial industrial issue for its impact on product distribution costs. Though quite important in practice, the time-constrained version of the VRP accounting for several types of vehicles and mdepots, called the extended VRP with time windows (m-VRPTW), has received less attention. Since it is an NP-hard problem, most of the current approaches to m-VRPTW are heuristic, thus providing good but not necessarily optimal solutions. This work presents a novel MILP mathematical framework for the m-depot heterogeneous-fleet VRPTW problem. The new optimization approach permits to find both the optimal vehicle route/schedule and the fleet size by choosing the best set of preceding nodes for each pickup point. To get a significant reduction on the problem size to tackle larger m-VRPTW problems, some elimination rules have been embedded in the MILP framework. When applied to a pair of examples, it was observed a remarkable saving in computer costs with regards to prior VRPTW optimization methods.
Multiproduct pipelines permit to transport large volumes of a wide range of refined petroleum pro... more Multiproduct pipelines permit to transport large volumes of a wide range of refined petroleum products from major supply sources to distribution centers near market areas. Batches of refined products and grades are pumped back-to-back in the same pipeline, often without any separation device between batches. The sequence and lengths of such pumping runs should be carefully selected in order to meet market demands at the promised dates while satisfying many pipeline operational constraints. This paper deals with the scheduling of a multiproduct pipeline system receiving a number of liquid products from a single refinery source to distribute them among several depots. A novel MILP continuous mathematical formulation that neither uses time discretization nor division of the pipeline into a number of single-product packs is presented. By developing a more rigorous problem representation, the quality of the pipeline schedule is significantly improved. Moreover, a severe reduction in binary variables and CPU time with regards to previous approaches is also achieved. To illustrate the proposed approach, a pair of real-world case studies was solved. Both involve the scheduling of a single pipeline carrying four oil derivatives from an oil refinery to five distribution depots. Higher pumping costs at daily peak periods were also considered. Compared with previous work, better solutions were found at much lower computational time.
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