Browse

1 - 10 of 41 items :

  • Business and Economics x
  • Business Informatics x
  • Transportation, Logistics, Air Traffic, Shipping x
Clear All
The application of AHP in the development of a taxonomy of merchant marine deck officers’ non-technical skills (NTS)

Abstract

The importance of NTS has been realised in many safety critical industries. Recently the maritime domain has also embraced the idea and implemented an NTS training course for both merchant marine deck and engineering officers. NTS encompass both interpersonal and cognitive skills such as situational awareness, teamwork, decision making, leadership, managerial skills, communication and language skills. Well-developed NTS training allow ship’s officers to recognise quickly when a problem is developing and manage the situation safely and efficiently with the available team members. As a result, the evaluation and grading of deck officers’ NTS is necessary to assure safety at sea, reduce the effects of human error on-board ships, and allow ship board operations to be performed safely. This paper identifies the skills necessary for deck officers to effectively perform their duties on the bridge of a ship. To achieve this, initially, a taxonomy of deck officers’ NTS is developed through a review of relevant literature and the conducting of semi-structured interviews with experienced seafarers. Subsequently, NTS weighting data is collected from experienced seafarers to allow the weight of each element of the taxonomy to be established by the use of the Analytical Hierarchy Process (AHP).

Open access
Comparison of emissions depending on the type of vehicle engine

Abstract

Road transport is showing growth in the period of globalization. Its task is to transport cargo as well as people to the required location within the shortest possible time and at the lowest price. Thus, road transport plays a crucial role in enabling the globalization to be developed and improved. However, the internal combustion engine hat prevail among the vehicles of freight and passenger transport are the producers of gaseous emissions from the exhaust gases. Many developed countries of the world has committed themselves, inter alia also trough the Paris Agreement, to reduce global warming, and thus to reduce the production of harmful gaseous emissions. The result is the endeavour to replace the internal combustion engine vehicles that burn carbon fuels with the vehicles powered by electric motors consuming electric energy. The reason of such trying claims that road transport using the internal combustion engine vehicles is environmentally aggressive, and the problem would not be solved by implementation of the vehicles with electric motors. Such claim is based on the fact that an electric car does not produce any of primary emissions. From an overall perspective, it is also necessary to take into account secondary emissions that are produced during the electric energy production by which is the vehicle with electric motor powered. The purpose of this article is to assume the possibility of reducing global pollution by replacing the internal combustion engine vehicles with the vehicles powered by electric motors in dependence with producing the emissions during the production of electric energy.

Open access
Forecasting US Tourists’ inflow to Slovenia by modified Holt-Winters Damped model: A case in the Tourism industry logistics and supply chains

Abstract

Forecasting is important in many branches of logistics, including the logistics related to Tourism supply chains. With an increasing inflow of American tourists, planning and forecasting the US tourists’ inflow to Slovenia have gained far more importance attention amongst scholars and practitioners. This study, therefore, was conducted to forecast the American tourists’ inflow to Slovenia using one of the predictive models based on the exponential smoothing approach, namely Holt-Winters damped additive (HWDA) exponential smoothing method. The model was modified by several improvements, while the obtained results were generalized to other supply chain components. The results show that the forecasting system can predict well the observed inflow, while the methodology used to derive the model might have enriched the plethora of existing practical forecasting approaches in the tourism domain. Benchmarking demonstrates that the proposed model outperforms a competitive ARIMA model and official forecasts. The practical implications are also discussed in this paper.

Open access
A Multi-Objective Solution of Green Vehicle Routing Problem

Abstract

Distribution is one of the major sources of carbon emissions and this issue has been addressed by Green Vehicle Routing Problem (GVRP). This problem aims to fulfill the demand of a set of customers using a homogeneous fleet of Alternative Fuel Vehicles (AFV) originating from a single depot. The problem also includes a set of Alternative Fuel Stations (AFS) that can serve the AFVs. Since AFVs started to operate very recently, Alternative Fuel Stations servicing them are very few. Therefore, the driving span of the AFVs is very limited. This makes the routing decisions of AFVs more difficult. In this study, we formulated a multi-objective optimization model of Green Vehicle Routing Problem with two conflicting objective functions. While the first objective of our GVRP formulation aims to minimize total CO 2 emission, which is proportional to the distance, the second aims to minimize the maximum traveling time of all routes. To solve this multi-objective problem, we used ɛ-constraint method, a multi-objective optimization technique, and found the Pareto optimal solutions. The problem is formulated as a Mixed-Integer Linear Programming (MILP) model in IBM OPL CPLEX. To test our proposed method, we generated two hypothetical but realistic distribution cases in Izmir, Turkey. The first case study focuses on an inner-city distribution in Izmir, and the second case study involves a regional distribution in the Aegean Region of Turkey. We presented the Pareto optimal solutions and showed that there is a tradeoff between the maximum distribution time and carbon emissions. The results showed that routes become shorter, the number of generated routes (and therefore, vehicles) increases and vehicles visit a lower number of fuel stations as the maximum traveling time decreases. We also showed that as maximum traveling time decreases, the solution time significantly decreases.

Open access
Review of pallet pooling studies

Abstract

Development of sharing economy has brought new opportunities to the development of green logistics. Pallet pooling is a typical type of sharing economy. It has been recently promoted in almost every country in the world. Researchers have reached a common agreement that establishing an effective pallet pool is of great importance to the pallets use efficiency. It is also believed that the implementation of pallet pool will substantially contribute to the economic and social development. Detailed analysis of pallet pooling such as benefit analysis, mode choose, pallet allocation model & algorithm, quality control, etc. are discussed in this paper. Based on literature review, several important problems are listed for future study. These problems are information management, supply chain management, rental pricing, pallets tracking and allocation, quality control, sustainable development (carbon emissions), and “internet plus pallet pooling”. Some suggestions on China’s pallet pooling development are proposed as well.

Open access
Vehicles leasing operations in Lagos state, Nigeria

Abstract

Vehicle is an important element of transport; and its financing especially in road transport comes in 3 ways; outright purchase, hire purchase and lease. Of all these three methods of road transport financing, leasing has attracted little attention in Nigeria transport research. This study was carried out to examine the development, types and form, operating characteristics and problems of vehicle lease in Lagos State, Nigeria. Aggregate number of vehicle leasing companies in Nigeria from inception to 2018 was obtained from corporate affairs commission (CAC). Four prominent vehicle leasing companies: Cashlink Leasing Plc (CLP), NIKKY Taurus Ltd (NTL), C & I Leasing (CIL) and SAMTL Leasing Ltd (SLL) were purposively selected for the operating characteristics and challenges of the leasing companies. 298 structured questionnaires were administered to the staffs of the selected companies seeking the types and forms of lease and challenges encountered in the course of operation using stratified and simple random samplings techniques. Vehicle leasing started in Nigeria from 1986 with the likes of pine hill leasing, Cashlink leasing, VT leasing in Lagos. Within 1986 and 2018, it has spread to 23 different urban cities and the number has increased to 297 companies in 2018. Operating and finance leases exist in the industry with majority of 91.6% of the companies practice operating lease. The staff strength and fleet size level of the leasing companies varies overtime but positively significant to their operations. However, poor pricing of lease service, inadequate finance of vehicle, default in payment of rental charges and high cost of maintenance minimize leasing service efficiency and effectiveness. It is recommended that government should provide subvention for vehicles acquisition, face-off of racketing vehicles from cites and legislate policy to regulate operational activities (entry and exit) of the companies.

Open access
Attitude of Motorists towards Road Ethics: Empirical Study

Abstract

Road traffic safety among socioeconomic issues has become the major concern across the globe due to rise in road crashes attributed largely to human factor. This study tends to address attitudinal behavior of road users towards road ethics in Ilorin metropolis-Nigeria; covering both driver and motorcyclists and perception of motorists on road traffic enforcement agent. Questionnaire was employed as survey tools. Ordered logistic model were used to analyse the data on attitude of motorists and road traffic laws enforcement agents. About 87% of the 440 administered questionnaire were returned valid. A 3-model analysis was carried out and the findings showed that the attitude of the motorists, road traffic law enforcement agents and demographical index (gender, age and education) correlated with, and influence compliance with road traffic laws.

Open access
Comparison of Lowest-Slot and Nearest-Stack Heuristics for Storage Assignment of Steel Bar Sets

Abstract

Our research objective is to lower intralogistics costs by minimizing the number of shuffling operations in a steel plant company commercial warehouse. The process of dispatching products consists of retrieving set of steel bar (SSB) from a floor stored stack or a special stacking frame by an overhead crane. To retrieve a targeted merchandise all SSB above targeted must be reshuffled. Proper assignment of storage locations is a key logistics problem for efficient order picking. We are comparing two heuristics, that do not require information of dispatching sequence of any stored products. We simulated the problem at hand with both methods. Our objective is to count the number of reshuffles using each heuristic on randomly generated examples and decide which is better in the long run. Our problem has similarities with storage assignment of steel plates or steel coils for minimization of reshuffling operations. The problem is also comparable to storage assignment of containers in a container yard. In our case we are dealing with a special stacking configuration of products, that demands different approach. We want to demonstrate which heuristic should be used in companies that lack necessary storage information infrastructure.

Open access
Electric Vehicles as Electricity Storages in Electric Power Systems

Abstract

Improvements in battery technology make electric vehicles more and more suitable for the use as electricity storages. Many benefits could be achieved by using electric vehicles for storing electricity in their batteries. This paper talks about the idea of electric vehicles as electricity storages in electric power systems. The idea has a great number of supporters, but also a significant part of the professional community believes that is unfeasible. This paper is not classified in either side and strives to give a realistic picture of this idea. For this purpose, findings from papers published in scientific journals are mainly used. There is also some information from websites, mainly for some technical issues. Partly, the opinions of the authors are present. Specificities of EVs and EPSs that enabled the birth of this idea are explained along with proposed concepts through which the idea can be implemented. Keeping with the vehicle to grid concept, issues about the implementation of the idea are considered. Achievements in the practical realization of the idea are also presented.

Open access
Optimal Bus Stops’ Allocation: A School Bus Routing Problem with Respect to Terrain Elevation

Abstract

The paper addresses the optimal bus stops allocation in the Laško municipality. The goal is to achieve a cost reduction by proper re-designing of a mandatory pupils’ transportation to their schools. The proposed heuristic optimization algorithm relies on data clustering and Monte Carlo simulation. The number of bus stops should be minimal possible that still assure a maximal service area, while keeping the minimal walking distances children have to go from their homes to the nearest bus stop. The working mechanism of the proposed algorithm is explained. The latter is driven by three-dimensional GIS data to take into account as much realistic dynamic properties of terrain as possible. The results show that the proposed algorithm achieves an optimal solution with only 37 optimal bus stops covering 94.6 % of all treated pupils despite the diversity and wideness of municipality, as well as the problematic characteristics of terrains’ elevation. The calculated bus stops will represent important guidelines to their actual physical implementation.

Open access