Sorting with a forklift

A fork stack is a generalised stack which allows pushes and pops of several items at a time. We consider the problem of determining which input streams can be sorted using a single forkstack, or dually, which permutations of a fixed input stream can be produced using a single forkstack. An algorithm is given to solve the sorting problem and the minimal unsortable sequences are found. The results are extended to fork stacks where there are bounds on how many items can be pushed and popped at one time. In this context we also establish how to enumerate the collection of sortable sequences.Comment: 24 pages, 2 figure

Private Standards, Handling and Hygiene in Fruit Export Supply Chains: A Preliminary Evaluation of the Economic Impact of Parallel Standards

With the emergence of private food safety and quality standards in developed countries fruit exporting countries in the developing world face increasing constraints to access markets in the rich industrialised countries in the North. Producers in the South have no alternative as to make the necessary investments on farms and in pack houses to comply with the requirements of these food quality and safety standards. The export of fresh fruit is an important component of South African agricultural exports, with citrus fruit exported to markets such as Europe being of particular importance. This paper reports selected results from a large research project into the impact of private standard compliance on the quality of the fruit and the returns to farmers. The research process involved a multi-disciplinary analysis of Agricultural Economics and Microbiology / Plant pathology as we analysed the dynamics of the citrus export supply chain from the farms in South Africa to the end consumer in Europe. Sampled fruit containers were followed through the whole supply chain which allowed us to provide an exposé of the behaviour of the different actors in the citrus supply chain and obtain some evidence of poor handling and hygiene standards by means of a comparison of the experimental observations with various relevant components of the EurepGAP control points and compliance criteria for fruit and vegetables. Observations suggest that these standards are adequately applied to the production and handling of fruit at the farm and pack house levels while on the other hand the subsequent stages (mainly after the importing harbour in Europe) of the fruit supply chain are seemingly not subjected to the same strict requirements laid out for producers, leading to fruit quality deterioration and financial losses for producers. This constitutes clear parallel standards in terms of fruit safety and quality standards between upstream and downstream sections of the supply chain and questions thus the purpose of the standards and the financial return for producers making large investments to comply with these privately introduced standards.International Relations/Trade,

A Proposal for the Optimization of Storage Areas in a Selected Enterprise

The current tough competition prevalent within the market economy is forcing business entities to achieve efficiency in their processes. This also applies to the transfer of goods from point A to point B, which is the subject of transportation. This process is influenced by many factors. It is necessary to not only consider the time,i.e. the fact that the required goods must be delivered in time, but it is also essential to take the financial aspect linked into account, for example, with the cost items such as fuel, salaries etc. These and many other factors also influence the movement of goods within a warehouse, in which the business entity must maximize the space required for the storage of the goods, while minimizing the time necessary for the storage, and equally while optimizing the cost. The aim of this paper follows from the above, which is based on the facts of the course of storage operations in the chosen enterprise,to design an optimal layout of the storage area which should increase the efficiency of the logistical operations

Lego Librarian: Book Sorter

Manual book sorting is time consuming and laborious. Traditionally, human librarians have to get the books from the circulation desk to be sorted and carry the books around to the right locations and putting it on the right shelf. It is prone to misplacement of books in the library. It is quite difficult and seems impractical to return the books back to the original locations daily. To overcome this problem, a book sorting robot known as Book Sorter, a small scaled prototype has been proposed as a simulation of an efficient method to ease the daunting task of librarians in the manual organisation of books. It is also proposed to provide a better allocation of resources of a library. Book Sorter is built as a robot that compliments another robot in LEGO Librarian called Book Carrier. LEGO Librarian is an automated system that is used for organising books on the shelf at the library. The scope of study for this project involves the current system used in the UTP library as well as the robotics application in the librarian system that covers some chapters of study. The activity diagram describes the overall process flow of the system and the development methodology used in this project is throwaway prototyping.. Several interview, survey, field test and acceptance testing were conducted and briefly discussed in Chapter 4. This project is expected to have vast potential to provide a view in real life especially in its capability to alleviate the intensive labours and efforts (time) in sorting the books automatically onto the right shelves

A Nightmare Revisited: The Resotration of the Canadian War Museum’s 8.8 cm Flak Gun

The German 8.8 cm Flugabwehrkanone (flak) gun is one of the most famous weapons of the Second World War. It was greatly feared by Allied soldiers and airmen alike. Just as every tank they encountered was a Tiger, so too was every German gun an “88.” In December 1998, the Canadian War Museum set out to restore the 88 in the museum’s collection and return to public view one of the few such artifacts in Canada. The museum’s gun was in extremely poor condition, and needed major work. Its components had been disassembled before it had come to the museum and had obviously been at the mercy of the elements for many years. In order to return this complicated weapon as close as possible to its original specifications, an enormous amount of technical information had to be amassed. Some of this should be of interest to readers of this journal, both as an account of a gun that wreaked havoc amongst Canadian soldiers in the Second World War, and as an insight into the nature of museum restoration procedures. The Friends of the Canadian War Museum raised $10,000 for the gun’s restoration, and without their funding the project could not have been undertaken. Several companies bid on the project and Musetek Ltd. won the contract. Work commenced during the second week of January 1999 and the gun’s restoration was completed by the first week of April 1999. The following article will be divided into three sections: 1) the history and development of the 8.8 cm; 2) the process of identifying the particular gun owned by the CWM, and 3) the story of the gun’s restoration

AUTOMATED GUIDED VEHICLE DESIGN USING INDUCTIVE LINE FOLLOWING METHOD ON AS/RS AS A SIMULATION IN SKILL DEVELOPMENT CENTER OF AUTOMATION INDUSTRIAL ENGINEERING FACULTY TELKOM UNIVERSITY

Material handling has an important role in the production process. Without a material handling, material cannot continue its process because the material cannot be transported from the current workstation to the next workstation. One of the material handling that is used in manufacture is AGV. AGV is unmanned material handling which is used battery as power supply and guided along define path. Study about how AGV work is important because AGV is an important part of the production process. Inspira is a skill development center of automation in Telkom University. In this skill development center, student can learn about anything related to automation. Simulation of how AGV work can be conducted by using Robotino®. Because it is equipped with infrared distance sensor, omni-directional drive, camera, and others that are similar with AGV. Inductive line will be a guidance for the Robotino® to transport the material from one workstation to another. With speed 200 mm/s, Robotino® still safe to move on the inductive line

Improving Cotton Warehousing Efficiencies Through Novel Bale Marketing Strategies: Aisle-Stacking and Block-Stacking

The National Cotton Council’s Vision 21 Cotton Flow Study sought to improve the flow of cotton through the gin and warehouse system. Time and motion data were collected from multiple warehouses as the basis for models, which simulate differences in the total time needed to assemble an order for three different bale selection techniques: the baseline method, a 4-bale marketing plan, or the use of MILLNet™ for Merchants software; and for two different methods of warehouse storage: aisle-stacking and block-stacking. In larger warehousing facilities using aisle-stacking, the use of MILLNet™ for Merchants software significantly decreased the time required to assemble an 88-bale load of cotton for shipping. However, in warehouses utilizing aisle-stacking, 4-bale marketing did not reduce the time required to assemble a load for shipment in aisle-stacking arrangements. Compared to baseline operations for block-stacking warehouses, 4-bale marketing and MILLNet™ for Merchants offered significant potential time savings in order assembly. The greatest time savings, 50%-75%, were realized using MILLNet™ for Merchants and pulling bales only from the fronts of the blocks. When MILLNet™ for Merchants was not an option, 4-bale marketing reduced total order assembly time by up to 56%. Block-stacking in a cotton warehouse was the most efficient way to assemble and load one 88-bale order. If the facility was small then using the 4-bale marketing method generated the shortest order assembly time. If the facility was medium or large, then the MILLNet™ for Merchant software generated shorter order assembly times. Other factors that may impact order assembly time are the expertise and experience of the facility management personnel, the number of bales within the warehouse, and the shipping method. When considering foreign and domestic shipments from a block-stacking warehouse, foreign shipments were the fastest to assemble and load regardless of the bale selection method, baseline, 4-bale marketing, or MILLNet™ for Merchants

TRANSPORT CHARACTERISTICS IN AUTOMATED PRODUCTION

In the paper manufacturing automation systems is divided into two classes: rigidautomation and flexible automation. The paper intends to highlight the decrease of transportation timewithin production processes as a result of transportation optimization. The objectives of currentindustry are: product quality and productivity increase, decreasing delivery time, the need to improveworking conditions, the use of specifications for each product. They are analyzed by tracing thetransportation time of a production company form Alba Iulia.manufacturing, transportation optimization, Petri, Markov process, systems flexibility