| 1. |
- Grubbström, Robert W., et al.
(författare)
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Ideas for introducing capacity planning into MRP applying input-output analysis and Laplace transforms
- 2001
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Ingår i: Promet - Traffic - Traffico. - 0353-5320. ; 13:6, s. 371-377
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Tidskriftsartikel (refereegranskat)abstract
- Laplace transform and input-output analysis have been used to formulate a theoretical basis for Material Requirements Planning (MRP) system. In this paper, we will formulate a model for capacity-constrained production-inventory system applying Laplace transform and input-output analysis, which is different from the classical method of handling the capacity problem.
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| 2. |
- Guo, Yi, et al.
(författare)
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Selection of Rail Station Locations on an Intercity Route Regarding Maximum Users’ Economic Profits
- 2023
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Ingår i: PROMET. - : Faculty of Transport and Traffic Sciences. - 0353-5320 .- 1848-4069. ; 35:4, s. 595-606
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Tidskriftsartikel (refereegranskat)abstract
- Cities located on a path of intercity railroads tend to be in a corridor system to increase com-merce and economic profits. Theoretic and practical work concerning train station locations can be used to provide factors that affect the choice of train station sites. In this paper, we find optimal places to locate train stations according to location theories and particular natural and socioeconomic characteristics. The methods we used are focused on maximising users’ economic profits associated with passenger and cargo transportation by finding optimal stations on the route. Furthermore, we created a general algebraic modelling system (GAMS) with linear planning, which is solvable using a C programming language (CPLEX) interac-tive optimiser. Case studies on 14 stations along the 820 km long Milak-Chabahar corridor helped us to simulate our model and test its feasibility at three alternative times to prove the outcomes. The stations would increase an average profit of 38.6%, 42.94% and 50.85%, but the growth varied in the stations. This research contributes to freight and passenger transportation engineers in railroad design. They benefit from the model to determine the location of a train station to obtain maximum user profits in that station and its surrounding areas.
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| 3. |
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| 4. |
- Mamdoohi, Amir Reza, et al.
(författare)
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Comparative Analysis of Safety Performance Indicators Based on Inductive Loop Detector Data
- 2014
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Ingår i: Promet: Traffic and Transportation. - : Faculty of Transport and Traffic Sciences. - 0353-5320 .- 1848-4069. ; 26:2, s. 139-149
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Tidskriftsartikel (refereegranskat)abstract
- Conflicts in traffic stream have been detected by different safety performance indicators. This study aims to empirically investigate the differences between different indicators in detecting rear-end conflicts and assessing the risk in an uninterrupted flow. Micro-level data of a 24-hr traffic stream (including 6,657 vehicles) were captured using inductive loop detectors installed on a rural freeway section. Different indicators (Time Headway (H), Time to Collision (TTC), Proportion of Stopping Distance (PSD), Deceleration Rate to Avoid Collision (DRAC) and Stopping Distance Index (SDI)) were used to measure each car following event in a bivalent state (safe/unsafe). Unsafe events associated with each indicator were detected and common unsafe events characterized by different indicators were identified. Temporal distributions of rear-end collision risks associated with each indicator at 15-min intervals were also compared. Finally, the 15-min risk values based on different indicators were categorized and compared across three levels (Low, Medium and High). Data mining and statistical techniques showed that while SDI is the single most conservative indicator, DRAC and TTC detect a few risky events but very equal ones. In almost all conflicts associated with TTC, headway is still lower than the critical threshold. However, there exist considerable risky events based on headway which are still safe according to TTC. Comparison of PSD and TTC also declares that almost all conflicts associated with TTC are also risky according to PSD.
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| 5. |
- Strömblad, Emma, et al.
(författare)
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Characteristics of Everyday Leisure Trips by Car in Sweden : Implications for Sustainability Measures
- 2022
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Ingår i: Promet - Traffic - Traffico. - 0353-5320. ; 34:4, s. 657-672
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Tidskriftsartikel (refereegranskat)abstract
- In search for measures to reduce greenhouse gas emissions from transport, insights into the characteristics of all sorts of trips and specifically trips by car are needed. This paper focuses on everyday leisure trips for social and recreational purposes. Travel behaviour for these purposes is analysed considering individual and household factors as well as properties of the trip, based on Swedish national travel survey data. The analysis reveals that everyday leisure trips are often of joint character and that the average distance travelled per person and day increases with, for example, income, cohabitation, children in the household and residence in rural areas. The result also shows that the studied characteristics vary between studied trip purposes, influencing the sustainability potential of a reduction in car use and suggested measures. For instance, the largest share of passenger mileage comes from social trips, whereas trips for exercise and outdoor life have the largest share of car trips below 5 km. Several characteristics indicate difficulties in transferring trips by car to, for example, bicycle or public transport due to convenience, economy, start times, company etc. The study indicates that there is a need to take a broader view of the effective potential.
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| 6. |
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| 7. |
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| 8. |
- Winslott Hiselius, Lena
(författare)
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Can Mobility Management Campaigning Contribute to Pro-Environmental Behaviour in General? Development of an Analytical Tool
- 2014
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Ingår i: Promet: Traffic and Transportation. - : Faculty of Transport and Traffic Sciences. - 0353-5320 .- 1848-4069. ; 26:3, s. 257-264
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Tidskriftsartikel (refereegranskat)abstract
- This paper brings to the fore the importance of a holistic approach to attaining a general pro-environmental behavioural change in order to reduce carbon emissions and the need to strive for a spillover of pro-environmental behaviour from one area to another. An adjusted version of the MaxSEM model is developed to capture differences in stages of behavioural change regarding environmental load on entering a Mobility Management campaign and one year after. The analytical tool is applied on two test samples in order to illustrate the tool and possible difficulties and methodological challenges. The test samples consist of participants in Mobility Management campaigns with personal incentives in two cities in Sweden. The application of the tool indicates e.g. that the timing of the survey is important and that there is need to upscale the MM-campaigns, in order to further discuss and analyse the effects of voluntary mobility measures in other domains.
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