| 1. |
- Alverhed, Elin, et al.
(författare)
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Autonomous last-mile delivery robots: a literature review
- 2024
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Ingår i: European Transport Research Review. - 1867-0717 .- 1866-8887. ; 16:1
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Forskningsöversikt (refereegranskat)abstract
- This literature review investigates how self-driving autonomous delivery robots (ADRs) impact last-mile deliveries, add value to the logistics and transport industry, and contribute to creating competitive business models. Autonomous vehicles are still a developing technology and ADRs could possibly be one of the solutions to the last-mile problem, in particular in cities and for urban freight with an increasing number of parcels to deliver. Last-mile delivery is also changing as e-commerce and more demanding customers emerge. Such development, however, faces challenges regarding infrastructure, externalities such as CO2 emissions, and shorter delivery-time requirements. This review, focused on ADRs, reveals four major themes (operations, infrastructure, regulations, and acceptance) through which we explain the barriers and benefits of using ADRs for last-mile deliveries. The review shows that the operations of ADRs can impact last-mile deliveries by lowering costs, optimising the use of time, and reducing externalities. The review also shows that the foundation of last-mile infrastructure would have to change if ADRs are to be used to a greater extent. Regulations for ADRs are still not yet in place, which makes the market somewhat confused. The acceptance of ADRs in society is another challenge because the innovation of ADRs is still new and unfamiliar. Altogether, the use of ADRs for last-mile deliveries shows great potential, based on the promising results of the articles reviewed. However, most studies on ADRs have been theoretical in nature, such as models, which highlights the need for real-world case studies and implementations.
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| 2. |
- Danielsson, Henrik, et al.
(författare)
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The effectiveness of working memory training with individuals with intellectual disabilities - a meta-analytic review
- 2015
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Ingår i: Frontiers in Psychology. - : Frontiers. - 1664-1078. ; 6:1230
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Forskningsöversikt (refereegranskat)abstract
- Working memory (WM) training has been increasingly popular in the last years. Previous studies have shown that individuals with intellectual disabilities (ID) have low WM capacity and therefore would benefit by this type of intervention. The aim of this study was to investigate the effect of WM and cognitive training for individuals with ID. The effects reported in previous studies have varied and therefore a meta-analysis of articles in the major databases was conducted. Inclusion criteria included to have a pretest posttest design with a training group and a control group and to have measures of WM or short-term memory. Ten studies with 28 comparisons were included. The results reveal a significant, but small, overall pretest posttest effect size (ES) for WM training for individuals with ID compared to controls. A mixed WM approach, including both verbal and visuo-spatial components working mainly on strategies, was the only significant training type with a medium ES. The most commonly reported training type, visuo-spatial WM training, was performed in 60 percent of the included comparisons and had a non-significant ES close to zero. We conclude that even if there is an overall effect of WM training, a mixed WM approach appears to cause this effect. Given the few studies included and the different characteristics of the included studies, interpretations should be done with caution. However, different types of interventions appear to have different effects. Even if the results were promising, more studies are needed to better understand how to design an effective WM intervention for this group and to understand if, and how, these short-term effects remain over time and transfer to everyday activities.
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| 3. |
- Eriksson, Lars, et al.
(författare)
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Performance and presence with head-movement produced motion parallax in simulated driving
- 2015
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Ingår i: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 34, s. 54-64
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Tidskriftsartikel (refereegranskat)abstract
- Driving simulator studies can reveal relevant and valid aspects of driving behavior, but underestimation of distance and speed can negatively affect the driver's performance, such as in performance of overtaking. One possible explanation for the underestimation of distance and speed is that two-dimensional projection of the visual scene disrupts the monocular-based illusory depth because of conflicting binocular and monocular information of depth. A possible solution might involve the strengthening of the monocular information so that the binocular information becomes less potent.In the present study, we used an advanced high-fidelity driving simulator to investigate whether adding the visual depth information of motion parallax from head movement affects sense of presence, judgment of distance and speed, and performance measures coupled with overtaking. The simulations included two types of driving scenario in which one was urban and the other was rural. The main results show no effect of this head-movement produced motion parallax on sense of presence, head movement, time to collision, distance judgment, or speed judgment.However, the results show an effect on lateral positioning. When initiating the overtaking maneuver there is a lateral positioning farther away from the road center as effect of the motion parallax in both types of scenario, which can be interpreted as indicating use of naturally occurring information that change behavior at overtaking. Nevertheless, only showing tendencies of effects, absent is any clear additional impact of this motion parallax in the simulated driving.
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| 4. |
- Kircher, Katja, 1973-, et al.
(författare)
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Bicyclists‘ speed adaptation strategies when conducting self-paced vs. system-paced smartphone tasks in traffic
- 2015
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Ingår i: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 28, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- The increasing prevalence of mobile phone usage while cycling has raised concerns, even though the number of cyclists involved in accidents does not increase at a comparable rate. A reason for this may be how cyclists adapt travelling speed and task execution to the current traffic situation. The aim of this study is to investigate speed adaptation among cyclists when conducting self-paced (initiated by the cyclist) vs. system-paced (initiated by somebody else) smartphone tasks in real traffic. Twenty-two cyclists completed a track in real traffic while listening to music, receiving and making calls, receiving and sending text messages, and searching for information on the internet. The route and the types of tasks were controlled, but the cyclists could choose rather freely when and where along the route to carry out the tasks, thus providing semi-naturalistic data on compensatory behaviour. The results clearly show that cyclists use conscious strategies to adapt their speed to accommodate the execution of secondary phone tasks. Regarding tactical behaviour, it was found that cyclists kept on cycling in 80% of the system-paced cases and in 70% of the self-paced cases. In the remaining cases, the cyclists chose to execute the phone task while standing still or when walking. Compared to the baseline (17.6 ± 3.5 km/h), the mean speed was slightly increased when the cyclists listened to music (18.2 ± 3.7 km/h) and clearly decreased when they interacted with the phone (13.0 ± 5.0 km/h). The speed reduction profile differed between self-paced and system-paced tasks with a preparatory speed reduction before task initiation for self-paced tasks. In conclusion, when the cyclists had the chance they either stopped or adapted their speed proactively to accommodate the execution of the phone task. For self-paced tasks, the speed reduction was finalised before task initialisation, and for system-paced tasks the speed adaptation occurred in reaction to the incoming task. It is recommended to investigate whether the observed compensatory behaviour is enough to offset the possible negative effects of smartphone use.
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| 5. |
- Kircher, Katja, 1973-, et al.
(författare)
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Cyklisters kompensationsstrategier när de använder mobil IT i trafiken
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det finns en oro att cyklister som använder mobil IT utgör en trafikfara, men trots den ökande användningen verkar inte olyckstalen stiga. Målet med denna studie är därför att undersöka om och i så fall hur cyklister anpassar sitt beteende när de använder mobil IT medan de cyklar. Tjugotvå unga cyklister fick cykla fem varv längs en gata på en cykelbana i verklig trafik. Under varje varv fick de utföra olika uppgifter: cykla som vanligt, lyssna på musik, bli uppringda och ringa, skriva och läsa sms, samt söka efter information på internet. Rutten och uppgifterna var förutbestämda, men cyklisterna fick till stor del själva välja var och när de utförde de olika uppgifterna. På så sätt kunde vi studera om cyklisterna använde någon strategi när de använde mobil IT samtidigt som de cyklade. Resultaten visar tydligt att cyklisterna i studien väljer strategier för att ta sig an de olika telefonuppgifterna och att de flesta cyklisterna är medvetna om vilka strategier de använder. De valda strategierna skiljer sig åt mellan cyklister och mellan olika situationer, men de har en gemensam nämnare – att motverka belastning från telefonuppgiften. Jämfört med att bara cykla normalt (17.6 ± 3.5 km/h) så ökar hastigheten något vid musiklyssnande (18.2 ± 3.7 km/h) medan hastigheten sänks markant när cyklisten hanterar telefonen (13.0 ± 5.0 km/h). För de uppgifter som cyklisten själv kan påverka (ringa upp, skriva sms, söka information på internet) så sänks hastigheten i god tid före användandet och för resterande uppgifter så sänks hastigheten när ringsignalen hörs. I 26 % av fallen valde cyklisterna att stanna eller att leda cykeln medan de utförde telefonuppgifterna. Även för blickbeteendet var det väldigt liten skillnad mellan att cykla som vanligt och att cykla med musik. Cyklisterna själva beskriver även fler strategier som inte framgår av mätningarna. Till exempel anger vissa att de lyssnar mer aktivt eller att de bara använder en hörlur, att de planerar sitt användande genom längre framförhållning eller genom att inte använda mobil IT i korsningar, eller genom att mana sig själva till att vara mer alerta. Kompensationsstrategin beror också på hur van cyklisten är att använda mobil IT.
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| 6. |
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| 7. |
- Kylhammar, Lisa, 1978, et al.
(författare)
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Effects of oxidation and redox-properties on the selectivity of heat-treated Ag/Al2O3 catalysts for HC-SCR of NOx
- 2007
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Ingår i: Topics in Catalysis. - : Springer Science and Business Media LLC. - 1572-9028 .- 1022-5528. ; 42-43:1-4, s. 119-122
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Tidskriftsartikel (refereegranskat)abstract
- Ag/Al2O3 catalysts (2 wt% Ag) have been prepared and calcined at different temperatures to render catalysts with different silver particle size or silver configuration. The differences in activity and selectivity of these catalysts are related to the activity for oxidation of NO and hydrocarbons, the NOx storage properties, and to the oxidation state of silver.
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| 8. |
- Lyckfeldt, Ola, et al.
(författare)
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Stabilization of alumina with polyelectrolyte and comb copolymer in solvent mixtures of water and alcohols
- 2009
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Ingår i: Journal of the European Ceramic Society. - : Elsevier BV. - 0955-2219 .- 1873-619X. ; 29:6, s. 1069-1076
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Tidskriftsartikel (refereegranskat)abstract
- Solvent mixtures of water and ethanol and water and isopropanol have been evaluated for processing of concentrated alumina suspensions. The addition of alcohols may increase the long-term stability of suspensions with soluble ceramic species such as magnesia, which is added as a sintering aid. A poly(acrylic acid) and a hydrophilic comb copolymer were used as dispersants for the different solvent mixtures. The aim was to compare the stabilization efficiency at normal processing conditions, pH 9-10, through rheological measurements and to develop a robust system including magnesia with long-term stability. The electrostatic stabilization of the dispersants in the different solvent mixtures was studied by zeta potential measurements. Highly negative zeta potentials were observed for the poly(acrylic acid) at pH 9-10 in the solvent mixtures. A charge contribution was also seen from the adsorbed comb copolymer, however smaller than for the poly(acrylic acid). Low viscosity was obtained for suspensions stabilized with poly(acrylic acid) in solvent mixtures with either 25 vol% ethanol or isopropanol. Higher alcohol to water ratio led to flocculation of the suspension when poly(acrylic acid) was used as dispersant. Alumina suspensions with added magnesia in isopropanol:water 25:75 and poly(acrylic acid) as dispersant showed long-term stability. The viscosity remained almost constant during 4 days of aging. Suspensions stabilized with the comb copolymer dispersant gave stable systems with ethanol and isopropanol concentrations between 25 and 75 vol%. The superior dispersing efficiency of the comb copolymer at alcohol contents above 25 vol% was believed to originate from steric stabilization in combination with low effective particle size, giving low viscosity through lower apparent solid contents of the suspension. © 2008 Elsevier Ltd. All rights reserved.
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| 9. |
- Magnusson, Lisa U., 1975, et al.
(författare)
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High expression of arachidonate 15-lipoxygenase and proinflammatory markers in human ischemic heart tissue
- 2012
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 424:2, s. 327-330
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Tidskriftsartikel (refereegranskat)abstract
- A common feature of the ischemic heart and atherosclerotic plaques is the presence of hypoxia (insufficient levels of oxygen in the tissue). Hypoxia has pronounced effects on almost every aspect of cell physiology, and the nuclear transcription factor hypoxia inducible factor-1 alpha or (HIF-1 alpha) regulates adaptive responses to low concentrations of oxygen in mammalian cells. In our recent work, we observed that hypoxia increases the proinflammatory enzyme arachidonate 15-lipoxygenase (ALOX15B) in human carotid plaques. ALOX15 has recently been shown to be present in the human myocardium, but the effect of ischemia on its expression has not been investigated. Here we test the hypothesis that ischemia of the heart leads to increased expression of ALOX15, and found an almost 2-fold increase in HIF-1 alpha mRNA expression and a 17-fold upregulation of ALOX15 mRNA expression in the ischemic heart biopsies from patients undergoing coronary bypass surgery compared with non ischemic heart tissue. To investigate the effect of low oxygen concentration on ALOX15 we incubated human vascular muscle cells in hypoxia and showed that expression of ALOX15 increased 22-fold compared with cells incubated in normoxic conditions. We also observed increased mRNA levels of proinflammatory markers in ischemic heart tissue compared with non-ischemic controls. In summary, we demonstrate increased ALOX15 in human ischemic heart biopsies. Furthermore we demonstrate that hypoxia increases ALOX15 in human muscle cells. Our results yield important insights into the underlying association between hypoxia and inflammation in the human ischemic heart disease. (C) 2012 Elsevier Inc. All rights reserved.
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| 10. |
- Nilsson, Karin, et al.
(författare)
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Structural Differences of the Semantic Network in Adolescents with Intellectual Disability
- 2021
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Ingår i: Big data and cognitive computing. - : MDPI. - 2504-2289. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- The semantic network structure is a core aspect of the mental lexicon and is, therefore, a key to understanding language development processes. This study investigated the structure of the semantic network of adolescents with intellectual disability (ID) and children with typical development (TD) using network analysis. The semantic networks of the participants (nID = 66; nTD = 49) were estimated from the semantic verbal fluency task with the pathfinder method. The groups were matched on the number of produced words. The average shortest path length (ASPL), the clustering coefficient (CC), and the network’s modularity (Q) of the two groups were compared. A significantly smaller ASPL and Q and a significantly higher CC were found for the adolescents with ID in comparison with the children with TD. Reasons for this might be differences in the language environment and differences in cognitive skills. The quality and quantity of the language input might differ for adolescents with ID due to differences in school curricula and because persons with ID tend to engage in different out-of-school activities compared to TD peers. Future studies should investigate the influence of different language environments on the language development of persons with ID
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