3,531 research outputs found

    Development of transportation and supply chain problems with the combination of agent-based simulation and network optimization

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    Demand drives a different range of supply chain and logistics location decisions, and agent-based modeling (ABM) introduces innovative solutions to address supply chain and logistics problems. This dissertation focuses on an agent-based and network optimization approach to resolve those problems and features three research projects that cover prevalent supply chain management and logistics problems. The first case study evaluates demographic densities in Norway, Finland, and Sweden, and covers how distribution center (DC) locations can be established using a minimizing trip distance approach. Furthermore, traveling time maps are developed for each scenario. In addition, the Nordic area consisting of those three countries is analyzed and five DC location optimization results are presented. The second case study introduces transportation cost modelling in the process of collecting tree logs from several districts and transporting them to the nearest collection point. This research project presents agent-based modelling (ABM) that incorporates comprehensively the key elements of the pick-up and delivery supply chain model and designs the components as autonomous agents communicating with each other. The modelling merges various components such as GIS routing, potential facility locations, random tree log pickup locations, fleet sizing, trip distance, and truck and train transportation. The entire pick-up and delivery operation are modeled by ABM and modeling outcomes are provided by time series charts such as the number of trucks in use, facilities inventory and travel distance. In addition, various scenarios of simulation based on potential facility locations and truck numbers are evaluated and the optimal facility location and fleet size are identified. In the third case study, an agent-based modeling strategy is used to address the problem of vehicle scheduling and fleet optimization. The solution method is employed to data from a real-world organization, and a set of key performance indicators are created to assess the resolution's effectiveness. The ABM method, contrary to other modeling approaches, is a fully customized method that can incorporate extensively various processes and elements. ABM applying the autonomous agent concept can integrate various components that exist in the complex supply chain and create a similar system to assess the supply chain efficiency.Tuotteiden kysyntä ohjaa erilaisia toimitusketju- ja logistiikkasijaintipäätöksiä, ja agenttipohjainen mallinnusmenetelmä (ABM) tuo innovatiivisia ratkaisuja toimitusketjun ja logistiikan ongelmien ratkaisemiseen. Tämä väitöskirja keskittyy agenttipohjaiseen mallinnusmenetelmään ja verkon optimointiin tällaisten ongelmien ratkaisemiseksi, ja sisältää kolme tapaustutkimusta, jotka voidaan luokitella kuuluvan yleisiin toimitusketjun hallinta- ja logistiikkaongelmiin. Ensimmäinen tapaustutkimus esittelee kuinka käyttämällä väestötiheyksiä Norjassa, Suomessa ja Ruotsissa voidaan määrittää strategioita jakelukeskusten (DC) sijaintiin käyttämällä matkan etäisyyden minimoimista. Kullekin skenaariolle kehitetään matka-aikakartat. Lisäksi analysoidaan näistä kolmesta maasta koostuvaa pohjoismaista aluetta ja esitetään viisi mahdollista sijaintia optimointituloksena. Toinen tapaustutkimus esittelee kuljetuskustannusmallintamisen prosessissa, jossa puutavaraa kerätään useilta alueilta ja kuljetetaan lähimpään keräyspisteeseen. Tämä tutkimusprojekti esittelee agenttipohjaista mallinnusta (ABM), joka yhdistää kattavasti noudon ja toimituksen toimitusketjumallin keskeiset elementit ja suunnittelee komponentit keskenään kommunikoiviksi autonomisiksi agenteiksi. Mallinnuksessa yhdistetään erilaisia komponentteja, kuten GIS-reititys, mahdolliset tilojen sijainnit, satunnaiset puunhakupaikat, kaluston mitoitus, matkan pituus sekä monimuotokuljetukset. ABM:n avulla mallinnetaan noutojen ja toimituksien koko ketju ja tuloksena saadaan aikasarjoja kuvaamaan käytössä olevat kuorma-autot, sekä varastomäärät ja ajetut matkat. Lisäksi arvioidaan erilaisia simuloinnin skenaarioita mahdollisten laitosten sijainnista ja kuorma-autojen lukumäärästä sekä tunnistetaan optimaalinen toimipisteen sijainti ja tarvittava autojen määrä. Kolmannessa tapaustutkimuksessa agenttipohjaista mallinnusstrategiaa käytetään ratkaisemaan ajoneuvojen aikataulujen ja kaluston optimoinnin ongelma. Ratkaisumenetelmää käytetään dataan, joka on peräisin todellisesta organisaatiosta, ja ratkaisun tehokkuuden arvioimiseksi luodaan lukuisia keskeisiä suorituskykyindikaattoreita. ABM-menetelmä, toisin kuin monet muut mallintamismenetelmät, on täysin räätälöitävissä oleva menetelmä, joka voi sisältää laajasti erilaisia prosesseja ja elementtejä. Autonomisia agentteja soveltava ABM voi integroida erilaisia komponentteja, jotka ovat olemassa monimutkaisessa toimitusketjussa ja luoda vastaavan järjestelmän toimitusketjun tehokkuuden arvioimiseksi yksityiskohtaisesti.fi=vertaisarvioitu|en=peerReviewed

    Indian population is 1.244 billion and World’s popul...

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    Abstract: Nowadys, computers are being used to mechanization, automation and to develop decision support system, expert system, GIS, Remote Sensing for taking strategic decision on the agricultural production and protection research. Recently remote sensing and geographic information system has place a major and crucial role in agriculture research especially in the field of yield prediction, suitability of soil for particular crop, integrated pest management, water management and site specific resource allocation of agriculture inputs, etc. India has accomplished an impressive progress in agriculture during the last six decades. At present, there are numerous challenges to be addressed on priority for making India a developed nation through progress in agriculture. In the current millennium, there are challenges of scarcity of land & resources and very high population to be faced simultaneously. Therefore, there are challenges to the Indian agricultural research to provide the food to the increasing population. The event of Information Communication Technology (ICT) as a highly powerful enabling tool for delivery of services in the public and the private sector has by now been universally recognized. ICT has the potential to change the information and knowledge in agricultural research as well as to disseminate it to the farmers. Science and technology are available globally, it must be realized that information and knowledge are also available globally. This opens the avenues for internationa

    NASA SBIR abstracts of 1990 phase 1 projects

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    The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number

    Application of GIS and Spatial Data Modeling to Archaeology: A Case Study in the American Southwest

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    One of the most important methodological advances in the archaeology of the past quarter century is the use of Geographic Information System (GIS) in archaeological research. Within this time frame, GIS has evolved from an emergent geospatial technology with limited mapmaking capabilities to a technology of choice for cultural resource managers, planners, and academic archaeologists alike. This dissertation examines the evolutionary trajectory and impact of GIS in the discipline since its introduction, and its potential to support new applications of GIS-driven innovation in archaeological research. As part of this project, two separate studies were conducted. The first study assessed adoption and diffusion trends for the technology based on the published literature from 1987-2010 using bibliometric and content analysis. These results suggest that despite adoption reaching a critical mass point in 2003-2006, GIS use is still maturing, and emphasis continues to be on methodological refinements rather than theoretical advances. Many of the technical developments coincide with larger changes within computing and in the convergence of technologies and platforms within the GIS industry. Recent publications, however, indicate the emergence of a possibly new direction for archaeological research which relies more on computationally intensive rather than empirical methods of investigation, in effect blurring traditional distinctions between method and theory. The second study conducted as part of this project explores the implications of this phenomenon by developing and implementing an application within a GIS environment for knowledge discovery in databases. The objective was to explore the feasibility and efficacy of geographic data mining using current technologies and archaeological data standards, identify barriers to its implementation, and demonstrate a new course for GIS-driven innovation in the field. Various archaeological and environmental datasets from the Fort Wingate Depot Activity in western New Mexico, USA were selected, compiled, prepared, and analyzed as part of the case study. Logistic regression was combined with Weights-of-Evidence modeling to discover previously unknown but statistically significant relationships and patterns within the prehistoric and historic data. This study offers suggestions on both how to adapt old data to new technologies and how to adapt new technologies to new ways of thinking

    Geographical Information Systems: the past, present and future

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    The main challenges of the XXI century are caused by the large amount of geospatial information through a GIS. Throughout time there have been many attempts to define Geographic Information Systems (GIS). Yet there is still no consensus on its definition and to restrict it to one is limited. In the acronym - Geographic Information Systems - geographic refers to the Earth's surface and near-surface, therefore, all human production and activity, as well as non-human are possible to spatialize using GIS.info:eu-repo/semantics/publishedVersio

    Gis-based gully erosion susceptibility mapping: a comparison of computational ensemble data mining models

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    Gully erosion destroys agricultural and domestic grazing land in many countries, especially those with arid and semi-arid climates and easily eroded rocks and soils. It also generates large amounts of sediment that can adversely impact downstream river channels. The main objective of this research is to accurately detect and predict areas prone to gully erosion. In this paper, we couple hybrid models of a commonly used base classifier (reduced pruning error tree, REPTree) with AdaBoost (AB), bagging (Bag), and random subspace (RS) algorithms to create gully erosion susceptibility maps for a sub-basin of the Shoor River watershed in northwestern Iran. We compare the performance of these models in terms of their ability to predict gully erosion and discuss their potential use in other arid and semi-arid areas. Our database comprises 242 gully erosion locations, which we randomly divided into training and testing sets with a ratio of 70/30. Based on expert knowledge and analysis of aerial photographs and satellite images, we selected 12 conditioning factors for gully erosion. We used multi-collinearity statistical techniques in the modeling process, and checked model performance using statistical indexes including precision, recall, F-measure, Matthew correlation coefficient (MCC), receiver operatic characteristic curve (ROC), precision-recall graph (PRC), Kappa, root mean square error (RMSE), relative absolute error (PRSE), mean absolute error (MAE), and relative absolute error (RAE). Results show that rainfall, elevation, and river density are the most important factors for gully erosion susceptibility mapping in the study area. All three hybrid models that we tested significantly enhanced and improved the predictive power of REPTree (AUC=0.800), but the RS-REPTree (AUC= 0.860) ensemble model outperformed the Bag-REPTree (AUC= 0.841) and the AB-REPTree (AUC= 0.805) models. We suggest that decision makers, planners, and environmental engineers employ the RS-REPTree hybrid model to better manage gully erosion-prone areas in Iran

    The scope for pavement porters: addressing the challenges of last-mile parcel delivery in London

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    The UK parcel sector generated almost £9 billion in revenue in 2015, with growth expected to increase by 15.6% in 2019 and is characterized by many independent players competing in an ‘everyone-delivers-everywhere’ culture leading to much replication of vehicle activity. With road space in urban centers being increasingly reallocated to pavement widening, bus and cycle lanes, there is growing interest in alternative solutions to the last-mile delivery problem. We make three contributions in this paper: firstly, through empirical analysis using carrier operational datasets, we quantify the characteristics of last-mile parcel operations and demonstrate the reliance placed on walking which can make up over 60% of the round time; secondly we introduce the concept of ‘portering’ where vans rendezvous with porters who operate within specific ‘patches’ to service consignees on-foot, potentially saving 86% in driving distance on some rounds; finally, we highlight the wider practical issues and optimization challenges associated with operating driving and portering rounds in inner urban areas

    Sustainable Geotechnics: Theory, Practice, and Applications

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