388 research outputs found
Leveraging Traffic and Surveillance Video Cameras for Urban Traffic
The objective of this project was to investigate the use of existing video resources, such as traffic cameras, police cameras, red light cameras, and security cameras for the long-term, real-time collection of traffic statistics. An additional objective was to gather similar statistics for pedestrians and bicyclists. Throughout the course of the project, we investigated several methods for tracking vehicles under challenging conditions. The initial plan called for tracking based on optical flow. However, it was found that current optical flowâestimating algorithms are not well suited to low-quality videoâhence, developing optical flow methods for low-quality video has been one aspect of this project. The method eventually used combines basic optical flow tracking with a learning detector for each tracked objectâthat is, the object is tracked both by its apparent movement and by its appearance should it temporarily disappear from or be obscured in the frame. We have produced a prototype software that allows the user to specify the vehicle trajectories of interest by drawing their shapes superimposed on a video frame. The software then tracks each vehicle as it travels through the frame, matches the vehicleâs movements to the most closely matching trajectory, and increases the vehicle count for that trajectory. In terms of pedestrian and bicycle counting, the system is capable of tracking these âobjectsâ as well, though at present it is not capable of distinguishing between the three classes automatically. Continuing research by the principal investigator under a different grant will establish this capability as well.Illinois Department of Transportation, R27-131Ope
Forests certification, effect on companies and forest owner associations
Det svenska skogsbruket har under senaste Ären blivit inriktat mot en breddad syn pÄ hÄllbarhet genom en rad lagförÀndringar som stÀller krav pÄ skogsÀgare. SkogsÀgare kan genom skogscertifieringsorganisationerna FSC och PEFC certifiera sig och visa att markÀgaren stÀller högre krav pÄ sitt skogsbruk Àn vad lagen krÀver.
Studiens syfte Àr att undersöka hur stora skogliga aktörer motiverar lönsamheten i skogscertifiering. För att uppnÄ studiens syfte har kvalitativa intervjuer med respondenter frÄn nÄgra av Sveriges största skogsaktörer genomförts. Intervjuerna har innefattat respondenternas syn pÄ certifiering och vilka hinder och fördelar som uppstÄr genom att vara certifierad. Studien har ocksÄ innefattat hur de stora aktörerna ser pÄ framtiden för certifiering.
Studiens resultat visar att skoglig certifiering har bÄde för- och nackdelar. Skoglig certifiering kan hjÀlpa ett företag att stÀrka dess varumÀrke och anseende. Det hjÀlper Àven företagen att hÄllbart skötta skogarna, och ger ett kvitto pÄ att skogen sköts pÄ ett bra sÀtt. De hinder som nÀmndes var kopplade till certifieringens administrativa arbete som Àr tids- och resurskrÀvande. Det hÀnder mycket inom skogssektorn, och det kommer krav frÄn bÄde EU och nationellt. Det har Àven nÀmnts att det finns en risk att vÄra svenska certifieringssystem kan komma att bli irrelevanta om högre krav frÄn EU implementeras i Sverige.The Swedish Forest have recently become more oriented towards more sustainable forestry through a series of legal changes that puts demands on forest owners. With the forest certification organizations FSC and PEFC the forest owners can certify their forests to show that they have a higher standard regarding sustainability and the environment than the law requires.
The purpose of the study is to investigate how large forestry actors justify the profitability of forest certification. To achieve the purpose of this study has been conducted through qualitative interviews with respondents from some of Sweden's largest forestry companies and organizations. The interviews included the respondentâs views on forest certification, what obstacles and advantages arise from being certified. The study has also included how major actors view the future of forest certification.
The results of the study have shown that forest certification both has advantages and disadvantages. Forest certification can help a company strengthen its brand and reputation. It also helps the companies to have well-managed forests and a receipt that the forest is managed in a good way. The obstacles that were mentioned were linked to the administrative work of the certification, which is time- and resource-consuming. A lot is happening in the forest sector, and there are demands from both the EU and nationally. It has also been mentioned that there is a risk that our Swedish certification systems may become irrelevant if higher requirements from the EU are implemented in Sweden
Serving library users during a pandemic: the case of Karlstad University Library, Sweden
During March 2020, all Swedish universities moved their teaching to an online environment due to the Covid-19 outbreak. Karlstad University Library in Sweden made a number of changes in order to reduce the spread of infection while at the same time maintaining a high level of library services to its users. Opening hours were drastically reduced. All study spaces were closed. Most of the staff were working from home. A new virtual reference desk via Zoom was launched to increase the library office hours. Since things happened fast, the internal staff training was done while at the same time providing the new reference service to the users. Some initial mistakes were made but in general, this âlearn-as-you-go methodâ worked surprisingly well
Cabernet: A Content Delivery Network for Moving Vehicles
This paper describes the design, implementation, and evaluation of Cabernet, a system to deliver data to and from moving vehicles using open 802.11 (WiFi) access points encountered opportunistically during travel. Network connectivity in Cabernet is both fleeting (access points are typicallywithin range for a few seconds) and intermittent (because the access points don't provide continuous coverage), and suffers from high packet loss rates over the wireless channel. On the positive side, in the absence of losses, achievable data rates over WiFi can reach many megabits per second. Unfortunately, current protocols don't establish end-to-end connectivity fast enough, don't cope well with intermittent connectivity, and don't handle high packet loss rates well enough to achieve this potential throughput. Cabernet incorporates two new techniques to improve data delivery throughput: QuickWifi, a streamlined client-side process to establish end-to-end connectivity quickly, reducing the mean time to establish connectivity from 12.9 seconds to less than 366 ms and CTP, a transport protocol that distinguishes congestion on the wired portion of the path from losses over the wireless link to reliably and efficiently deliver data to nodes in cars. We have deployed the system on a fleet of 10 taxis, each running several hours per day in the Boston area. Our experiments show that CTP improves throughput by a factor of 2x over TCP and that QuickWifi increases the number of connectionsby a factor of 4x over unoptimized approaches. Thus, Cabernet is perhaps the first practical system capable of delivering data to moving vehicles over existing short-range WiFi radios, with a mean transfer capacity of approximately 38 megabytes/hour per car, or a mean rate of 87 kbit/s
Social Mobility in Sweden before the Welfare State
We use historical census data to show that Sweden exhibited high levels of intergenerational occupational mobility several decades before the rise of the welfare state. Mobility rates were higher than in other nineteenth- and twentieth-century European countries, closer to those observed in the highly mobile nineteenth-century United States. We leverage mobility variation across Swedish municipalities to shed light on potential determinants: economic growth and migration are positively correlated with mobility, consistent with the patterns observed across countrie
General Bounds on Electronic Shot Noise in the Absence of Currents
We investigate the charge and heat electronic noise in a generic two-terminal mesoscopic conductor in the absence of the corresponding charge and heat currents. Despite these currents being zero, shot noise is generated in the system. We show that, irrespective of the conductorâs details and the specific nonequilibrium conditions, the charge shot noise never exceeds its thermal counterpart, thus establishing a general bound. Such a bound does not exist in the case of heat noise, which reveals a fundamental difference between charge and heat transport under zero-current conditions
Expression of 22 serotonin-related genes in rat brain after sub-acute serotonin depletion or reuptake inhibition
Objective: Although the assessment of expression of serotonin-related genes in experimental animals has become a common strategy to shed light on variations in brain serotonergic function, it remains largely unknown to what extent the manipulation of serotonin levels causes detectable changes in gene expression. We therefore chose to investigate how sub-acute depletion or elevation of brain serotonin influences the expression of a number of serotonin-related genes in six brain areas. Methods: Male Wistar rats were administered a serotonin synthesis inhibitor, para-chlorophenylalanine (p-CPA), or a serotonin reuptake inhibitor, paroxetine, for 3 days and then sacrificed. The expression of a number of serotonin-related genes in the raphe nuclei, hypothalamus, amygdala, striatum, hippocampus and prefrontal cortex was investigated using real-time quantitative PCR (rt-qPCR). Results: While most of the studied genes were uninfluenced by paroxetine treatment, we could observe a robust downregulation of tryptophan hydroxylase-2 in the brain region where the serotonergic cell bodies reside, that is, the raphe nuclei. p-CPA induced a significant increase in the expression of Htr1b and Htr2a in amygdala and of Htr2c in the striatum and a marked reduction in the expression of Htr6 in prefrontal cortex; it also enhanced the expression of the brain-derived neurotrophic factor (Bdnf) in raphe and hippocampus. Conclusion: With some notable exceptions, the expression of most of the studied genes is left unchanged by short-term modulation of extracellular levels of serotonin
Optimized winter wheat production in Kiev region of Ukraine : a case study on cultivation properties and management focusing on sowing date and nitrogen fertilization
Ukraine is the tenth largest wheat producer in the world but average yields are low, about 3 ton ha-1. A better understanding of growth conditions and factors limiting yield is importantin developing strategies to increase grain yield. This Masterâs thesis examined the conditions for winter wheat cultivation (Grain Alliance strategy) in Berezan in the Kiev region of northern Ukraine, and the potential to increase crop yields. The wheat cultivation in seven nearby fields in Berezan was compared with one reference field in Uppsala in Sweden. The effect of sowing date was studied by determining plant development and growth in fields with different sowing dates. The effect of fertilization level was also studied in these fields. In the sowing date trials, the factors plants per square meter in late autumn and spring, shoots per plant in late autumn and spring, and plant weight in late autumn were measured. The yield-forming factors ears m-2, kernels per ear, grain size and grain yield were also measured.In the fertilization trials, only grain yield factors were measured. To determine the growing conditions the soil physical properties and water availability were measured. The development of the winter wheat was also simulated by a phenology model with data from local weather stations.
The climate in Kiev is 3-5 ËC warmer than for Uppsala during the period April-August. It results in more rapid plant development in Kiev compared with Uppsala and 4-5 weeks earlier maturity. Precipitation and evapotranspiration are higher in Kiev than in Uppsala. Soil conditions in the Kiev region are favourable, with good soil aeration and low bulk density combined with relatively high amounts of plant-available water. A normal year the amount of precipitation and soil water storage is adequate to supply the wheat with water and avoid drought on both the clay soil in the field in Uppsala and the silty loam in the fields in Kiev. The relatively high temperature and availability of water motivates a cultivation strategy with relatively high ear densities to achieve high yield, as ear size can be reduced by rapid plant development. If winter wheat is sown during the first 2-3 weeks of September there are good opportunities to use relatively low seed rates, as lower plant number can be compensated by tillering. If sowing is postponed quite high seed rates are justified.
The early-sown winter wheat in this study had significantly greater biomass and tillering in autumn than late-sown wheat. Plant number was higher for late sowing dates, depending on higher seed rates. Both early- and late-sown wheat survived winter very well. Plant stand density was high in all the seven fields in Berezan, much higher than in the reference field in Uppsala. There was a large reduction of tillers in spring, but final number of ears was still relatively high. As variety and seed rates varied between trials with different sowing dates, it is not possible to claim significant effects of grain yield depending on sowing date. Kernel size was normal but ear size was relatively low, and was the yield factor with highest correlation to yield level in the different fields.
Yield level was generally high, even in treatments with low fertilization, and yield increases for high fertilization rates (above 160 kg N ha-1) were relatively low. This indicates quiteextensive mineralization from the soil. No significant difference in yield level was found between wheat fertilized with equal amounts of nitrogen applied in autumn and spring compared with spring only. From a crop perspective, nitrogen from fertilizer must be available at the beginning of stem jointing, when the need is highest. By dividing the fertilization into 2-3 application occasions from early spring to heading, it is possible to adjust the nitrogen rate to development and growth conditions to match stand requirements.
The Grain Alliance cultivation strategy gave considerably higher winter wheat yield than the average for the Kiev region, probably due to more intensive management, with the crop not limited by fertilizer deficiency or plant protection problems. Using varieties that combine hardiness and high yield potential, establishing plant stands of sufficient density and performing field operations, for example sowing and fertilization, at the right time are issues to work with for further improvement of winter wheat yield in Ukraine
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