ORiON Pub Date : 2019-12-20 DOI: 10.5784/35-2-651

M. Bashe, M. Shuma-Iwisi, M. V. Wyk

引用次数: 2

Editorial to Volume 35(2) 第35卷(2)社论

ORiON Pub Date : 2019-12-20 DOI: 10.5784/35-2-669

S. Terblanche

引用次数: 0

Picking location metrics for order batching on a unidirectional cyclical picking line 单向循环拣货线上订单批处理的拣货位置指标

ORiON Pub Date : 2019-12-20 DOI: 10.5784/35-2-646

F. Hofmann, SE Visagie

{"title":"Picking location metrics for order batching on a unidirectional cyclical picking line","authors":"F. Hofmann, SE Visagie","doi":"10.5784/35-2-646","DOIUrl":"https://doi.org/10.5784/35-2-646","url":null,"abstract":"In this paper order batching is extended to a picking system with the layout of a unidirectional cyclical picking line. The objective is to minimise the walking distance of pickers in the picking line. The setup of the picking system under consideration is related to unidirectional carousel systems. Three order-to-route closeness metrics are introduced to approximate walking distance, since the orders will be batched before the pickers are routed. All metrics are based on the picking location describing when a picker has to stop at a location to collect the items for an order. These metrics comprise a number of stops, a number of non-identical stops and a stops ratio measurement. Besides exact solution approaches, four greedy heuristics as well as six metaheuristics are applied to combine similar orders in batches. All metrics are tested using real life data of 50 sample picking lines in a distribution centre of a prominent South African retailer. The capacity of the picking device is restricted, thus the maximum batch size of two orders per batch is allowed. The best combination of metric and solution approach is identified. A regression analysis supports the idea that the introduced metrics can be used to approximate walking distance. The combination of stops ratio metric and the greedy random heuristic generate the best results in terms of minimum number of total cycles traversed as well as computational time to find the solution.","PeriodicalId":30587,"journal":{"name":"ORiON","volume":"12 1","pages":"161-186"},"PeriodicalIF":0.0,"publicationDate":"2019-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84998263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

New goodness-of-fit test for exponentiality based on a conditional moment characterisation 基于条件矩表征的指数拟合优度新检验

ORiON Pub Date : 2019-12-20 DOI: 10.5784/35-2-661

M. Smuts, J. Allison, L. Santana

引用次数: 3

Development of a map-matching algorithm for dynamic-sampling-rate GPS signals to determine vehicle routes on a MATSim network 基于MATSim网络的动态采样率GPS信号地图匹配算法研究

ORiON Pub Date : 2019-06-28 DOI: 10.5784/35-1-636

Jb Vosloo, J. Joubert

{"title":"Development of a map-matching algorithm for dynamic-sampling-rate GPS signals to determine vehicle routes on a MATSim network","authors":"Jb Vosloo, J. Joubert","doi":"10.5784/35-1-636","DOIUrl":"https://doi.org/10.5784/35-1-636","url":null,"abstract":"The rapid development and proliferation of global positioning system (GPS)-enabled systems and devices have led to a significant increase in the availability of transport data, more specifically GPS trajectories, that can be used in researching vehicle activities. In order to save data storage- and handling costs many vehicle tracking systems only store low-frequency trajectories for vehicles. A number of existing methods used to map GPS trajectories to a digital road network were analysed and such an algorithm was implemented in Multi-Agent Transport Simulation (MATSim), an open source collaborative simulation package for Java. The map-matching algorithm was tested on a simple grid network and a real and extensive network of the City of Cape Town, South Africa. Experimentation showed the network size has the biggest influence on algorithm execution time and that a network must be reduced to include only the links that the vehicle most likely traversed. The algorithm is not suited for trajectories with sampling rates less than 5 seconds as it can result in unrealistic paths chosen, but it manages to obtain accuracies of around 80% up until sampling sizes of around 50 seconds whereafter the accuracy decreases. Further experimentation also revealed optimal algorithm parameters for matching trajectories on the Cape Town network. The use case for the implementation was to infer basic vehicle travel information, such as route travelled and speed of travel, for municipal waste collection vehicles in the City of Cape Town, South Africa.","PeriodicalId":30587,"journal":{"name":"ORiON","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74120248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

On the discrepancy between the objective and risk neutral densities in the pricing of European options 欧式期权定价中目标密度与风险中性密度的差异

ORiON Pub Date : 2019-06-28 DOI: 10.5784/35-1-647

I. Visagie, G. Grobler

引用次数: 1

Editorial to Volume 35(1) 第35卷(1)社论

ORiON Pub Date : 2019-06-28 DOI: 10.5784/35-1-656

S. Terblanche

引用次数: 0

Self-organisation in traffic signal control algorithms under light traffic conditions 轻交通条件下交通信号控制算法的自组织研究

ORiON Pub Date : 2019-06-28 DOI: 10.5784/35-1-605

Sj Movius, JH van Vuuren

{"title":"Self-organisation in traffic signal control algorithms under light traffic conditions","authors":"Sj Movius, JH van Vuuren","doi":"10.5784/35-1-605","DOIUrl":"https://doi.org/10.5784/35-1-605","url":null,"abstract":"Fixed-time control and vehicle-actuated control are two distinct types of traffic signal control. The latter control method involves switching traffic signals based on detected traffic flows and thus offers more flexibility (appropriate for lighter traffic conditions) than the former, which relies solely on cyclic, predetermined signal phases that are better suited for heavier traffic conditions. The notion of self-organisation has relatively recently been proposed as an alternative approach towards improving traffic signal control, particularly under light traffic conditions, due to its flexible nature and its potential to result in emergent behaviour. The effectiveness of five existing self-organising traffic signal control strategies from the literature and a fixed-control strategy are compared in this paper within a newly designed agent-based, microscopic traffic simulation model. Various shortcomings of three of these algorithms are identified and algorithmic improvements are suggested to remedy these deficiencies. The relative performance improvements resulting from these algorithmic modifications are then quantified by their implementation in the aforementioned traffic simulation model. Finally, a new self-organising algorithm is proposed that is particularly effective under lighter traffic conditions.","PeriodicalId":30587,"journal":{"name":"ORiON","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86178348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Making use of survival analysis to indirectly model loss given default 利用生存分析来间接模拟给定违约情况下的损失

ORiON Pub Date : 2019-01-14 DOI: 10.5784/34-2-588

Morné Joubert, T. Verster, H. Raubenheimer

引用次数: 8

Editorial to Volume 34(2) 第34卷(2)社论

ORiON Pub Date : 2019-01-14 DOI: 10.5784/34-2-635

S. Terblanche

引用次数: 0

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