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1 – 10 of over 49000

Abstract

Details

Handbook of Transport Systems and Traffic Control
Type: Book
ISBN: 978-1-61-583246-0

Abstract

Details

Public Transport in Developing Countries
Type: Book
ISBN: 978-0-08-045681-2

Open Access
Article
Publication date: 1 December 2022

Chaehwan Lim, Gyuseung Kim and Hun-Koo Ha

Since airlines that employ their resources effectively will achieve operating profitability, air route resource allocation is significant for airlines. This study aims to…

Abstract

Purpose

Since airlines that employ their resources effectively will achieve operating profitability, air route resource allocation is significant for airlines. This study aims to investigate an appropriate model to reallocate resources into each air route of an airline company.

Design/methodology/approach

This study proposes a network centralized data envelopment analysis (DEA) models with slack-based measure (SBM). The proposed model not only takes into account the two interconnected stages but also considers the nonradial approach with transfer-in and transfer-out slacks for resource reallocating. Furthermore, the authors modify the objective function to an input-oriented function with SBM, and divide the model into passenger and freight parts, which makes the model more realistic for the characteristic of air routes.

Findings

The empirical analysis using an airline company's internal data provides airline operators with information on how they increase or decrease input resources, which can serve as a practical guideline of resource reallocation. Specifically, the results indicate that the airline company should increase their input resources into long-haul air routes such as KOR-OCN while decreasing their input resources into short-haul air routes such as Korean-Oceania (KOR-OCN), Korean-Chinese (KOR-CHN), Korean-Southeast Asian (KOR-SEA), Korean-Japanese (KOR-JPN).

Originality/value

Although some papers evaluate air route efficiencies based on the DEA approach, a few existing papers have addressed resource allocation for air routes. This paper is the first to study the resource reallocation for air routes based on the DEA approach, contributing to the literature in expanding the scope of research on resource reallocation.

Details

Journal of International Logistics and Trade, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1738-2122

Keywords

Article
Publication date: 3 November 2022

Emre Aydoğan and Cem Cetek

The purpose of this paper is to create a flight route optimization for all flights that aims to minimize the total cost consists of fuel cost, ground delay cost and air…

Abstract

Purpose

The purpose of this paper is to create a flight route optimization for all flights that aims to minimize the total cost consists of fuel cost, ground delay cost and air delay cost over the fixed route and free route airspaces.

Design/methodology/approach

Efficient usage of current available airspace capacity becomes more and more important with the increasing flight demands. The efficient capacity usage of an airspace is generally in contradiction to optimum flight efficiency of a single flight. It can only be achieved with the holistic approach that focusing all flights over mixed airspaces and their routes instead of single flight route optimization for a single airspace. In the scope of this paper, optimization methods were developed to find the best route planning for all flights considering the benefits of all flights not only a single flight. This paper is searching for an optimization to reduce the total cost for all flights in mixed airspaces. With the developed optimization models, the determination of conflict-free optimum routes and delay amounts was achieved with airway capacity and separation minimum constraints in mixed airspaces. The mathematical model and the simulated annealing method were developed for these purposes.

Findings

The total cost values for flights were minimized by both developed mathematical model and simulated annealing algorithm. With the mathematical model, a reduction in total route length of 4.13% and a reduction in fuel consumption of 3.95% was achieved in a mixed airspace. The optimization algorithm with simulated annealing has also 3.11% flight distance saving and 3.03% fuel consumption enhancement.

Research limitations/implications

Although the wind condition can change the fuel consumption and flight durations, the paper does not include the wind condition effects. If the wind condition effect is considered, the shortest route may not always cause the least fuel consumption especially under the head wind condition.

Practical implications

The results of this paper show that a flight route optimization as a holistic approach considering the all flight demand information enhances the fuel consumption and flight duration. Because of this reason, the developed optimization model can be effectively used to minimize the fuel consumption and reduce the exhaust emissions of aircraft.

Originality/value

This paper develops the mathematical model and simulated annealing algorithm for the optimization of flight route over the mixed airspaces that compose of fixed and free route airspaces. Each model offers the best available and conflict-free route plan and if necessary required delay amounts for each demanded flight under the airspace capacity, airspace route structure and used separation minimum for each airspace.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 1 February 1971

NICOS CHRISTOFIDES

In many cases it is not appropriate to utilise a system of daily route scheduling. This paper looks at the situation where a fixed route system is required and the demand…

Abstract

In many cases it is not appropriate to utilise a system of daily route scheduling. This paper looks at the situation where a fixed route system is required and the demand characteristics of the customers must be matched to the system.

Details

International Journal of Physical Distribution, vol. 1 no. 2
Type: Research Article
ISSN: 0020-7527

Article
Publication date: 1 November 1997

Charles G. Petersen

Order picking, the assembly of a customer’s order from items in storage, is an essential link in the supply chain and is the major cost component of warehousing. The…

5993

Abstract

Order picking, the assembly of a customer’s order from items in storage, is an essential link in the supply chain and is the major cost component of warehousing. The critical issue is to simultaneously reduce the cost and increase the speed of the order picking activity. The main objectives are to: evaluate various routeing policies in a random storage environment; evaluate the impact of warehouse shape and pick‐up/drop‐off location; and examine the interaction of the routeing policies, warehouse shape, and pick‐up/drop‐off location under different pick list sizes. The experimental results clearly indicate that the optimal routeing procedure generates significantly shorter routes than heuristic methods. The composite and largest gap routeing policies are, however, significantly better than simpler heuristic procedures. Further testing, in addition, indicates that the shape of the warehouse and the location of the pick‐up/drop‐off point can affect the picking efficiency.

Details

International Journal of Operations & Production Management, vol. 17 no. 11
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 1 February 2005

Moon‐Sang Jeong and Jong‐Tae Park

A lot of recent research has been focused on developing network mobility management to support the movement of a mobile network consisting of several mobile nodes. The…

Abstract

A lot of recent research has been focused on developing network mobility management to support the movement of a mobile network consisting of several mobile nodes. The IETF NEMO working group proposed the NEMO basic support protocol that defines a methodology for supporting such network mobility using bi‐directional tunneling between the home agent and the mobile router. However, this protocol has been found to suffer from the so‐called ‘dog‐leg problem’, and despite alternative research efforts to solve this problem, there are still limitations in the efficiency of real time data transmission and intra‐domain communication. Accordingly, the current paper proposes a new route optimization methodology that uses unidirectional tunneling and a tree‐based intra‐domain routing mechanism. As such, the proposed scheme can provide faster signaling and data transmission and be easily extended to support micro‐mobility without any additional extensions. The performance of the proposed scheme is also evaluated to demonstrate its efficiency.

Details

International Journal of Pervasive Computing and Communications, vol. 1 no. 1
Type: Research Article
ISSN: 1742-7371

Keywords

Article
Publication date: 18 November 2013

Lianyu Fu, Jian Wang and Qiang Guo

The purpose of this paper is to provide the method and system to conduct online measurement and the characterization of temperature during printed circuit board (PCB…

Abstract

Purpose

The purpose of this paper is to provide the method and system to conduct online measurement and the characterization of temperature during printed circuit board (PCB) routing process as well as the optimization of router design based on the investigation of routing temperature.

Design/methodology/approach

The background of this research is introduced first. Then the method to measure the routing temperature on-line by using an infrared camera is presented. The routing process is characterized by investigating the routing temperature. Tool design optimization is conducted based on the temperature in processing PCB with aluminum substrate. Finally the concluding remarks of this research are presented.

Findings

The routing temperature can be accurately measured by an infrared camera. Routing temperature is sensitive to properties of PCB, types of router and routing parameters. Very high temperature is experienced if non-appropriate routers are used to process board with aluminum substrate. It is demonstrated by the experiments that two fluted tool, three fluted tool and coated tool with three flutes are suitable for aluminum substrate processing by considering the low temperature and the nice surface finish.

Originality/value

The paper highlights the key points to measure the routing temperature on-line by an infrared camera and characterize the routing process and optimize the tool design by investigating the measured temperature as well.

Details

Circuit World, vol. 39 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 October 1999

Charles G. Petersen

Order picking, the activity by which a number of goods are retrieved from a warehousing system to satisfy a number of customer orders, is an essential link in the supply…

8541

Abstract

Order picking, the activity by which a number of goods are retrieved from a warehousing system to satisfy a number of customer orders, is an essential link in the supply chain and is the major cost component of warehousing. The critical issue is to simultaneously reduce the cost and increase the speed of the order picking activity. The main objectives of this paper are: evaluate various routing heuristics and an optimal routine in a volume‐based and random storage environment; compare the performance of volume‐based storage to random storage; and examine the impact of travel speed and picking rates on routing and storage policy performance. The experimental results show the solution gap between routing heuristics and optimal routing is highly dependent on the travel speed and picking rate, the storage policy, and the size of the pick list. In addition, volume‐based storage produced significant savings over random storage, but again these savings are dependent on the travel speed and picking rate.

Details

International Journal of Operations & Production Management, vol. 19 no. 10
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 24 April 2009

Anton Gittens and Boppana V. Chowdary

The main objective of this paper is to introduce the development of a novel feature recognition system for escape route planning. The genetic algorithm (GA) can be a…

Abstract

Purpose

The main objective of this paper is to introduce the development of a novel feature recognition system for escape route planning. The genetic algorithm (GA) can be a useful tool in solving route planning problems.

Design/methodology/approach

A computer‐aided design (CAD) system is proposed to help to predict the best escape route. The system is based on a feature recognition process, which will scan a CAD drawing to determine the centroid points of corridors, and determine the best escape route with the help of GA.

Findings

The feature recognition system provides a quick method of determining the available pathways for use in escape route planning.

Research limitations/implications

Factors such as multiple story buildings, number of occupants, or fire spread are not considered. Thus the system will be useful in the initial stages of escape route planning.

Practical implications

The system is limited to perpendicular walls, which should be of the same thickness. Doorways should also be a constant size. Thus the system will be useful in determining where escape routes exist, and attempt to determine the best route based on that information.

Originality/value

This paper shows how legacy drawings from various CAD systems may be reused to plan escape routes, rather than creating new drawings for the same purpose. This is useful to those in escape route planning, since the redrawing of plans using custom software is inefficient.

Details

Disaster Prevention and Management: An International Journal, vol. 18 no. 2
Type: Research Article
ISSN: 0965-3562

Keywords

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