Systematic Literature Review Of Particle Swarm Optimization Implementation For Time-Dependent Vehicle Routing Problem

Time-dependent VRP (TDVRP) is one of the three VRP variants that have not been widely explored in research in the field of operational research, while Particle Swarm Optimization (PSO) is an optimization algorithm in the field of operational research that uses many variables in its application. There is much research conducted about TDVRP, but few of them discuss PSO's implementation. This article presented as a literature review which aimed to find a research gap about implementation of PSO to resolve TDVRP cases. The research was conducted in five stages. The first stage, a review protocol defined in the form of research questions and methods to perform the review. The second stage is references searching. The third stage is screening the search result. The fourth stage is extracting data from references based on research questions. The fifth stage is reporting the study literature results. The results obtained from the screening process were 37 eligible reference articles, from 172 search results articles. The results of extraction and analysis of 37 reference articles show that research on TDVRP discusses the duration of travel time between 2 locations. The route optimization parameter is determined from the cost of the trip, including the total distance traveled, the total travel time, the number of routes, and the number used vehicles. The datasets that are used in research consist of 2 types, real-world datasets and simulation datasets. Solomon Benchmark is a simulation dataset that is widely used in the case of TDVRP. Research on PSO in the TDVRP case is dominated by the discussion of modifications to determine random values of PSO variables

Optimización de Rutas basadas en Soft Computing para Movilidad Inteligente

La movilidad y transporte de pasajeros y mercancías es uno de los principales desafíos para el desarrollo de islas, ciudades y territorios. La prosperidad, competitividad y sostenibilidad de múltiples áreas económicas se ven afectadas por la movilidad. El crecimiento de la población, la capacidad limitada de los sistemas e infraestructuras de transporte y el impacto medioambiental del transporte fuerza a los territorios en el desarrollo de una movilidad sostenible y efectiva. En este complejo escenario, un territorio con una gestión del transporte y movilidad sostenible y eficiente ofrece a los ciudadanos una mejor calidad de vida. La transformación digital y las TIC impulsan la mejora de los servicios de movilidad para los ciudadanos, ayudan a gestionar correctamente la demanda en las redes de transporte y generan valor económico y ambiental. El surgimiento de la movilidad inteligente integra el sistema de transporte, las infraestructuras y las tecnologías para hacer que el transporte de pasajeros y mercancías sea eficiente, accesible, más seguro y limpio. Por lo tanto, las estrategias de movilidad inteligente deben ser capaces de proporcionar beneficios económicos y ambientales tangibles y mejorar la calidad del transporte de mercancías y pasajeros. Significa tomar acciones en múltiples frentes; gestión eficiente de la carga y la movilidad de pasajeros, reducción del impacto medioambiental, mejora de la planificación y la eficiencia del transporte público, reducción de la congestión, optimización del uso de la infraestructura física, entre otros. Una de las operaciones clave para los servicios de movilidad es la planificación de rutas. Esta actividad operativa incluye principalmente dos modos de transporte, mercancías y pasajeros. La mayoría de los transportes de mercancías y pasajeros se realizan a través de transporte por carretera. Las decisiones tomadas con respecto a las operaciones de planificación de rutas afectan económica y ambientalmente, y en general a la calidad de vida de los ciudadanos en los territorios en los que se desarrollan. Las operaciones de planificación de rutas se pueden optimizar para mejorar diferentes aspectos como la calidad del servicio, costes y flexibilidad del mismo, consumo de energía, impacto medioambiental, sostenibilidad, entre otros. La tarea de abordar las operaciones de planificación de rutas da lugar a la aparición de complejos problemas de optimización combinatoria que requieren considerar múltiples requisitos, restricciones, fuentes de información, entre otros. En la mayoría de los casos, estos problemas de optimización se clasifican como NP-duros con respecto a su complejidad computacional. Esta clase de problemas requiere enfoques de optimización eficientes y estrategias inteligentes para obtener soluciones de alta calidad y evitar grandes tiempos de cálculo. En este sentido, los enfoques de optimización aproximados, como las heurísticas y metaheurísticas, y las técnicas inteligentes inherentes a la Inteligencia Artificial y la Soft Computing han demostrado ser métodos efectivos y eficientes para resolver complejos problemas de planificación de rutas. Esta tesis presentada en la modalidad de compendio de publicaciones tiene como objetivo diseñar, implementar y validar procedimientos de optimización simples, eficientes y flexibles basados ​​en Inteligencia Artificial y Soft Computing dedicados a mejorar las soluciones de planificación de rutas en los contextos de transporte de mercancías, planificación personalizada de rutas turísticas y transporte eco-eficiente de residuos reciclables. Se han propuesto varios enfoques de solución para resolver problemas como Vehicle Routing Problem with Time Windows, Periodic Vehicle Routing Problem with Time Windows, Team Orienteering Problem with Time Windows, Tourist Trip Design Problem y variantes del mundo real y nuevas extensiones de los problemas mencionados. La calidad del servicio, la orientación al cliente, la imprecisión e incertidumbre en la información y la ecoeficiencia son criterios considerados en los problemas de planificación de rutas identificados. Los experimentos computacionales han demostrado que los métodos y técnicas propuestos son adecuados para obtener soluciones de alta calidad en tiempos computacionales cortos y pueden incorporarse como módulos en sistemas de transporte inteligentes

What Makes Online Grocers Work? A Case Study Analysis of Factors Contributing to Online Grocery Store Profitability

This research examined the factors contributing to the performance of online grocers prior to, and following, the 2000 dot.com collapse. The primary goals were to assess the relationship between a company’s business model(s) and its performance in the online grocery channel and to determine if there were other company and/or market related factors that could account for company performance. To assess the primary goals, a case based theory building process was utilized. A three-way cross-case analysis comprising Peapod, GroceryWorks, and Tesco examined the common profit components, the structural category (e.g., pure-play, partnership, and hybrid) profit components, and the idiosyncratic profit components related to each specific company. Based on the analysis, it was determined that online grocery store business models could be represented at three distinct, but hierarchically, related levels. The first level was termed the core model and represented the basic profit structure that all online grocers needed in order to conduct operations. The next model level was termed the structural model and represented the profit structure associated with the specific business model configuration (i.e., pure-play, partnership, hybrid). The last model level was termed the augmented model and represented the company’s business model when idiosyncratic profit components were included. In relation to the five company related factors, scalability, rate of expansion, and the automation level were potential candidates for helping to explain online grocer performance. In addition, all the market structure related factors were deemed possible candidates for helping to explain online grocer performance. The study concluded by positing an alternative hypothesis concerning the performance of online grocers. Prior to this study, the prevailing wisdom was that the business models were the primary cause of online grocer performance. However, based on the core model analysis, it was hypothesized that the customer relationship activities (i.e., advertising, promotions, and loyalty program tie-ins) were the real drivers of online grocer performance

An assessment of the sustainability of E-fulfilment models for the delivery of fast moving consumer goods to the home

Online retail sales are growing rapidly and have captured a significant proportion of the retail market in many countries. Although companies are under mounting pressure to reduce their environmental impact, the environmental effect of the different online distribution strategies remains unclear. Most previous studies of this subject have only included partial effects and consequences. To enable a more holistic understanding, this study proposes a more inclusive framework of environmental assessment based on life cycle analysis. This was applied to fast moving consumer goods (FMCG). Previous studies have shown that the last mile delivery contributes significantly to the environmental impact of online retailing, mainly because of the nature of the home delivery operations, including narrow time windows and short order lead times. If consumers were to buy products online on a subscription basis and give the supplier more control over the replenishment process there might be less need for fast deliveries, creating opportunities to improve the efficiency of home deliveries and reduce their environmental impact. The study classified different forms of subscription arrangement, assessed their relative attractiveness to consumers and examined their likely impact on the supply chain. Consumer views on subscriptions were surveyed by means of focus group discussions and interviews. To assess the likely supply chain impacts of subscriptions, the literature on vendor-managed inventory was consulted. A Life-Cycle Assessment (LCA) model was built to quantify and compare the environmental impact of various e-fulfilment models for FMCG products in the United Kingdom. This study reveals that the method of execution have a large influence on the environmental impact. In store-based retailing, the energy consumption within the supermarket is a significant contributor to the total greenhouse gas emissions. On the other hand, some forms of home delivery, involving for example the use of parcel networks with no pre-agreed time-slots and relatively high rates of delivery failure and customer collection, are also carbon-intensive. This contribution of consumer trips to the total footprint is much smaller in case of van-based deliveries where pre-agreed time-windows are used. Regardless of the business model, the total carbon footprint per item depends heavily on the number of items per delivery. Consequently, companies or consumers looking to decrease the environmental impact of online shopping should maximise the number of items per delivery. The study concludes with an assessment of the strengths, weaknesses and possible environmental improvements of each of the efulfilment methods, taking account of the possible role of subscriptions

Ordonnancement de camions dans une plateforme logistique : complexité, méthodes de résolution et incertitudes

La problématique dite de crossdocking a été source de beaucoup d'attention ces dernières années dans la littérature. Un crossdock est une plateforme logistique favorisant, par une synchronisation efficace des camions entrants et sortants, une rotation rapide des produits, le volume de produits stockés devant être le plus faible possible. Le crossdocking soulève de nombreux problèmes logistiques, dont notamment celui de l'ordonnancement des camions entrants et sortants sur les quais de la plateforme. L'objectif classiquement considéré dans la littérature pour ce problème est la minimisation du makespan, critère très répandu en d'ordonnancement. Pour le crossdocking néanmoins, minimiser la date de départ du dernier camion ne garantie pas nécessairement une bonne synchronisation des camions et le makespan ne semble donc pas être l'objectif le plus pertinent. Pour répondre au besoin de synchronisation et favoriser les rotations rapides, notre travail propose alternativement de minimiser la somme des temps de séjour des palettes dans le stock. Nous étudions d'abord la version déterministe de ce problème d'ordonnancement. Sa complexité est détaillée selon différentes hypothèses pour identifier les éléments menant à sa NP-difficulté. Différentes méthodes de résolutions sont proposées. Une méthode classique de programmation linéaire en nombres entiers utilisant des variables de décision indexées par le temps. Une famille d'inégalités valides est également proposée et exploitée dans un algorithme avec ajout itératif de coupes. Des méthodes basées sur la programmation par contraintes sont enfin proposées. Une analyse comparative de ces différentes méthodes est proposée. Dans un deuxième temps, nous étudions une version non-déterministe de notre problème d'ordonnancement dans laquelle des incertitudes sur les dates d'arrivée des camions sont introduites sous la forme d'intervalles de temps équiprobables. Une méthode d'ordonnancement proactive-réactive utilisant le concept de groupes d'opérations permutables est proposée pour faire face aux incertitudes. Des groupes de camions permutables sont séquencés et affectés aux quais puis, durant l'exécution d'ordonnancement, en fonction de la réalisation des dates d'arrivée, un ordre est choisi dans chaque groupe à l'aide d'un algorithme réactif.Crossdocking has received a lot of attention in the literature in recent years. A crossdock is a logistic platform that promotes rapid product turnover through efficient synchronization of incoming and outgoing trucks, with the volume of products stored being kept as low as possible. Crossdocking raises many logistical problems, including the scheduling of incoming and outgoing trucks on the platform's docks. The classical objective considered in the literature for this problem is the minimization of the makespan, a very common criterion in scheduling. However, for crossdocking, minimizing the departure date of the last truck does not necessarily guarantee a good synchronization of the trucks and the makespan does not seem to be the most relevant objective. In order to meet the need for synchronization and to help fast rotations, our work proposes alternatively to minimize the sum of the pallets' sojourn times in the warehouse. We first study the deterministic version of this scheduling problem. Its complexity is detailed under different assumptions to identify the elements leading to its NP-hardness. Different solution methods are proposed. A classical integer linear programming method using time-indexed decision variables. A family of valid inequalities is also proposed and exploited in an algorithm with iterative addition of cuts. Finally, methods based on constraint programming are proposed. A comparative analysis of these different methods is proposed. In a second step, we study a non-deterministic version of our scheduling problem in which uncertainties on truck arrival dates are introduced in the form of equiprobable time intervals. A proactive-reactive scheduling method using the concept of permutable operation groups is proposed to cope with the uncertainties. Groups of permutable trucks are sequenced and assigned to the docks and then, during the scheduling run, based on the realization of arrival dates, an order is chosen in each group using a reactive algorithm

Winona Daily News

https://openriver.winona.edu/winonadailynews/2034/thumbnail.jp

2010-11 Catalog

Aiken Technical College annually publishes a catalog with information about the university, student life, academic programs, and faculty and staff listings

Astronautics and aeronautics, 1976. A chronology

A chronology of events concerning astronautics and aeronautics for the year 1976 is presented. Some of the many and varied topics include the aerospace industry, planetary exploration, space transportation system, defense department programs, politics, and aerospace medicine. The entries are organized by the month and presented in a news release format

Las caras cambiantes de las mujeres en la India, a través de las lentes de arte y artistas activistas

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Políticas y Sociología, leída el 22-07-2020The aim of this thesis is to study the changing status of women in India through their representation and practices in art. To evaluate how art practices of Indian women might be addressing empowerment, promoting socio-economic and progressive cultures. I base my arguments on the premise that art has the power to transform societies, as affirmed by Ernst Fischer in his essay The Necessity of Art.7This thesis attempts to analyse the impact of privileged and rural artists practices, their feminist and humanist concerns. The study was inspired by two pioneering exhibitions. Tiger by the Tail! Women Artists of India Transforming Culture, held at the Women's Studies Research Center, Brandeis University, Boston;8 almost coincidental with Global Feminisms in the Brooklyn museum...El objetivo principal de esta tesis es estudiar los cambios en la situación de la mujer en India a través de su representación en el arte y sus prácticas artísticas. Examino cómo podrían abordar cuestiones de empoderamiento, promover mejoras socioeconómicas y culturas progresistas. Parte de la premisa del poder del arte para forjar avances en las sociedades, tal como recoge Ernst Fischer en su ensayo The Necessity of Art.1Analizo el impacto del trabajo de las artistas privilegiadas y rurales, y sus preocupaciones feministas y humanistas. Esta investigación empezó con dos exposiciones pioneras...Fac. de Ciencias Políticas y SociologíaTRUEunpu