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Pedestrian detection and tracking are essential problems in the field of computer vision, having a wide range of applications in surveillance, security, autonomous driving and robotics areas. Although people detection and tracking are generally considered widely-used technologies currently, however, occlusions still remain a major challenge. In this paper, we propose an approach to improve the detection and tracking performance in multi-camera scenarios with overlapping field-of-views, which allows for better handling of occlusion problem. It mainly includes monocular people detection, projection, fusion, probabilistic occupancy map generation and multi-object tracking steps. Evaluations for detection and tracking on WILDTRACK dataset have been implemented and the results indicate that our approach outperforms state-of-the-art deep learning methods which haven’t been trained on WILDTRACK. Fotgängarnas upptäckt och spårning är väsentliga problem inom datorsynen och har ett brett spektrum av applikationer inom övervakning, säkerhet, autonom körning och robotikområden. Även om människors upptäckt och spårning allmänt betraktas som allmänt använd teknik för närvarande, förblir dock ocklusioner en stor utmaning. I det här förslaget föreslår vi en metod för att förbättra upptäcktoch spårningsprestanda i multikamerascenarier med överlappande synfält, vilket möjliggör bättre hantering av ocklusionsproblem. Det inkluderar främst monokulära människors upptäckt, projicering, fusion, probabilistisk kartläggning av kartong och spårning av flera objekt. Utvärderingar för upptäckt och spårning på WILDTRACK-datasats har implementerats och resultaten indikerar att vår strategi överträffar toppmodern djupinlärningsmetoder som inte har utbildats på WILDTRACK.

Multicore and other parallel computer systems increasingly expose architectural aspects such as different memory access latencies depending on the physical memory address/location. In order to achieve high performance, programmers need to take these non-uniformities into consideration but this not only complicates the programming process but also leads to code that is not performance portable between different architectures. Task-centric programming models, such as OpenMP tasks, relieve the programmer from explicitly mapping computation on threads while still enabling effective resource management. We propose a task scheduling approach which uses programmer annotations and architecture awareness to identify the location of data regions that are operated upon by an OpenMP task. We have made an initial implementation of such a locality-aware OpenMP task scheduler for the Tilera TilerPro64 architecture and provide some initial results showing its effectiveness in fulfilling the need to minimize non-uniform access latencies to data and resources. ENCORE EU project QC 20120109

The prevention of incidents and injuries is fundamental for any industry activity since those events may result in serious economic, environmental, and human losses. Due to the centralization of Linde filling operations within Sweden, several of their plants are being phased out to move the production to Enköping. The elevated raise of Linde's production led to a high increase of forklift drivers and stock levels and consequently brought up the number of incidents related to forklift driving. This thesis aims to obtain knowledge to mitigate forklift truck related safety hazards as well as understand how to eliminate risks and unsafe situations at this type of operation. This project was divided into 3 phases. Phase I consisted of understanding operations routines and its safety risks, assessing Enköping site internal state (with a safety survey, and several visits and interviews), and benchmarking the most common practices based on other companies' forklift-related processes (with visits and interviews). In phase II, parallelly to ISite software implementation, studies utilizing different engineering tools (Spaghetti Diagram, VSM, Fishbone Diagram, and FMEA) were performed in order to gather information and understand how to optimize the site's forklift-related safety. In this phase, a tailored observational KPI was developed in order to assess the site independently of incident measurement regarding four groups: Site, Pedestrian activity, Forklift operation, and Forklift operator behavior. In phase III, all data acquired was discussed, and conclusions were made based on the data analysis and discussions of the results of Phase II implementation allied with the theoretical references. The survey findings showed the high degree of importance given to safety at Linde in Enköping. It also revealed, in addition to all engineering tools applied, which elements should be focused in order to optimize the forklift trucks operational safety (mainly related to Technology dimension). Based on the benchmark comparison, it is possible to allege that the absence of a maintenance facility is the main disadvantage of Linde in Enköping. In contrast, the usage of I-Site fleet management software represents an important step towards safety. The I-Site knowledge and the awareness of its benefits grew among management and operators as setup issues, and technical malfunctioning was eliminated. The observational KPI has obtained preliminary overall values above 0,82 for all groups (on a scale of 0 to 1), proving itself capable of measuring the safety performance and identifying risks and unsafe situations. Att förebygga incidenter och skador är grundläggande för all branschaktivitet eftersom dessa händelser kan leda till allvarliga ekonomiska, miljömässiga och mänskliga förluster. På grund av centraliseringen av Lindes fyllningsverksamheten inom Sverige har flera av deras anläggningar fasats ut för att flytta produktionen till Enköping. Den utökade produktionen på Linde Enköping skapade behov av fler truckförare, högre lagernivåer och ökade följaktligen antalet incidenter relaterade till gaffeltruck. Avhandlingen syftar till att få kunskap för att mildra säkerhetsrisker för gaffeltruckar samt förstå hur man kan eliminera risker och osäkra situationer vid denna typ av verksamhet. Detta projekt delades in i tre faser. Fas I bestod av att förstå driftsrutiner och dess säkerhetsrisker, utvärdera det interna tillståndet på Linde Enköpings arbetsplats (med en säkerhetsundersökning, flera besök och olika intervjuer) och benchmarka de vanligaste metoderna baserat på andra företags gaffeltruckrelaterade processer (med besök och intervjuer). I fas II, parallellt med I-Site-programvaruimplementering, utfördes studier med olika tekniska verktyg (Spaghetti Diagram, VSM, Fishbone Diagram och FMEA) för att undersöka och förstå hur man optimerar verksamhetens gaffeltruckrelaterade säkerhet. I denna fas utvecklades en skräddarsydd observations-KPI för att utvärdera verksamheten oberoende av att mäta incidenter avseende fyra grupper: Plats, fotgängare, gaffeltruck och beteende för gaffeltruck. I fas III diskuterades alla förvärvade data, slutsatser gjordes baserade på dataanalysen och diskussionerna om resultaten av fas II-implementering tillsammans med teoretiska referenser. Undersökningsresultaten visade hur högt säkerhet prioriteras vid Linde Enköping. Den avslöjade också, utöver alla tillämpade konstruktionsverktyg, vilka element som bör fokuseras på för att optimera truckens driftssäkerhet (främst relaterad till teknikdimension). Baserat på den benchmarking som genomfördes är det möjligt att hävda att frånvaron av underhållsanläggning är den största nackdelen med Linde i Enköping. Däremot är användningen av mjukvara för I-Site-flottanhantering ett viktigt steg mot säkerheten. Kunskapen om I-SITE och medvetenheten om dess fördelar växte bland ledningen och operatörerna när installationsproblem och tekniska funktionsfel eliminerades. Utfallen för observations-KPI har erhållit preliminära totalvärden över 0,82 för alla grupper (i en skala från 0 till 1), och visar sig kapabel att mäta säkerhet i genomförande samt att identifiera risker och osäkra situationer.

We use kinetic particle-in-cell and magnetohydrodynamic simulations supported by an observational dataset to investigate magnetic reconnection in clusters of null points in space plasma. The magnetic configuration under investigation is driven by fast adiabatic flux rope compression that dissipates almost half of the initial magnetic field energy. In this phase powerful currents are excited producing secondary instabilities, and the system is brought into a state of `intermittent turbulence' within a few ion gyro-periods. Reconnection events are distributed all over the simulation domain and energy dissipation is rather volume-filling. Numerous spiral null points interconnected via their spines form null lines embedded into magnetic flux ropes; null point pairs demonstrate the signatures of torsional spine reconnection. However, energy dissipation mainly happens in the shear layers formed by adjacent flux ropes with oppositely directed currents. In these regions radial null pairs are spontaneously emerging and vanishing, associated with electron streams and small-scale current sheets. The number of spiral nulls in the simulation outweighs the number of radial nulls by a factor of 5\---10, in accordance with Cluster observations in the Earth's magnetosheath. Twisted magnetic fields with embedded spiral null points might indicate the regions of major energy dissipation for future space missions such as Magnetospheric Multiscale Mission (MMS).

Railway track stiffness (vertical track load divided by track deflection) is a basic parameter oftrack design which influences the bearing capacity, the dynamic behaviour of passing vehiclesand, in particular, track geometry quality and the life of track components. Track stiffness is abroad topic and in this thesis some aspects are treated comprehensively. In the introductionpart of the thesis, track stiffness and track stiffness measurements are put in their propercontext of track maintenance and condition assessment. The first aspect is measurement of track stiffness. During the course of this project, Banverkethas developed a new device for measurement of dynamic track stiffness called RSMV(Rolling Stiffness Measurement Vehicle). The RSMV is capable of exciting the trackdynamically through two oscillating masses above one wheelset. The dynamic stiffness is acomplex-valued quantity where magnitude is the direct relation between applied load anddeflection (kN/mm) and phase is a measure of deflection-delay by comparison with force. Thephase has partial relationship with damping properties and ground vibration. The RSMVrepeatability is convincing and both overall measurements at higher speeds (up to 50 km/h)and detailed investigations (below 10 km/h) can be performed. The measurement systemdevelopment is described in Paper A and B. The second aspect is evaluation of track stiffness measurements along the track from a trackengineering perspective. Actual values of stiffness as well as variations along the track areimportant, but cannot always answer maintenance and design related questions alone. InPaper D track stiffness is studied in combination with measurements of track geometryquality (longitudinal level) and ground penetrating radar (GPR). The different measurementsare complementary and a more reliable condition assessment is possible by the combinedanalysis. The relation between soft soils and dynamic track stiffness measurements is studiedin Paper C. Soft soils are easily found and quantified by stiffness measurements, in particularif the soft layer is in the upper part of the substructure. There are also possibilities to directlyrelate substructure properties to track stiffness measurements. Environmental vibrations areoften related to soft soils and partly covered in Paper C. One explanation of the excitationmechanism of train induced environmental vibrations is short waved irregular supportconditions. This is described in Paper E, where track stiffness was evinced to have normalvariations of 2 – 10 % between adjacent sleepers and variations up to 30 % were found. Anindicative way of finding irregular support conditions is by means of filtering longitudinallevel, which is also described in the paper. Train-track interaction simulation is used in PaperH to study track stiffness influence on track performance. Various parameters of trackperformance are considered, e.g. rail sectional moment, rail displacement, forces at wheel-railinterface and on sleepers, and vehicle accelerations. Determining optimal track stiffness froman engineering perspective is an important task as it impacts all listed parameters. The third aspect, efficient maintenance, is only partially covered. As track stiffness relates toother condition data when studied from a maintenance perspective, vertical geometricaldefects (longitudinal level and corrugation/roughness) are studied in paper F. The generalmagnitude dependency of wavelength is revealed and ways of handling this in conditionassessment are proposed. Also a methodology for automated analysis of a large set ofcondition data is proposed in Paper G. A case study where dynamic track stiffness,longitudinal level and ground penetrating radar are considered manifests the importance oftrack stiffness measurements, particularly for soil/embankment related issues. QC 20100623

Denna licentiatavhandling handlar om lediga hyreslägenheter. I avhandlingens första del beskrivs och analyseras dels hur problemet med lediga lägenheter ser ut på den svenska bostadshyresmarknaden under åren 1990-1994 och dels hur problemet hanteras av svenska kommunala bostadsföretag. Dataunderlaget har insamlats via enkäter och hämtats från offentlig statistik. I avhandlingens andra del görs en litteraturundersökning som leder vidare till en bestämning av begrepp, relevanta att använda vid teoretiska analyser av vakansgrader på en marknad. Resultaten i den första delen visar att de lediga lägenheterna på bostadshyresmarknaden koncentrerats till vissa delmarknader. Lägenheterna karakätiseras av egenskaper som gör dem oattraktiva på marknaden, alternativt för dyra. Företagen hanterar problemet lediga lägenheter på sätt som kan försklaras av marknadsmodellen monopol, nämligen genom prisanpassningari form av prisdiskriminaering och kvantitetsanpassningar i form av rivning. Rivning har använts i oväntat stor omfattning, ca 3% av företagens bestånd har rivits under den undersökta perioden. Sänkt hyra har inget smaband med efterfrågeförändringar, däremot med utbudsförändringar i form av ökad konkurrens. Flera resultat av den statistiska analysen pekar spledes mot att marknadsstrukturen har betydelse för att förutsäga hur de kommunala bostadsföretagen kommer att agera i situationer som kräver pris- eller kvantitetsanpassningar. Företagen har också använt sig av olika slag av kortsiktiga kvantitetsanpassningar, vilket är intressant ur teoretisk synpunkt därför att man inte bruka r tala om kvantitetsanpassningar på kort sikt. Genomgången av vetenskaplig litterautr i anhandlingens andra del, visar att begreppet naturlig vakansgrad är ett etablerat teoretiskt begrepp men att det hittills varken är entydgit definierat eller entydigt använt. För att råda bot på detta göra en bestämning och komplettering av de begrepp som används för att analysera vakanser med metodiken kvalitativ komparativ statik. Begreppen är gilitga både för marknadsmodellen perfekt konkurrens och marknadsmodellen monopolitsisk konkurrens och enheterna kan vara antal lägenheter såväl som antal veckor. This licentiate thesis treats the problem of vacancies in the rental housing market. THe first part of the thesis consists of an empirical study aimed at enlighten how the vacancies are handled by Swedish Municipal Housing Companies between the years 1990 and 1994. THe data is collected through a postal survey which was sent to a choice of Swedish Municipal Housing Companies, namely those companies with a high overall vacancy rate so that it could be expected that these companies have a vacancy problem. The results of the survey is structured in a way that make them possible to relate to economic theory and conduct an analysis in terms of what kinds of adjustments have been made by the companies as a response to exogenic changes on the local housing market. IN a descriptive part of the results, it becomes clear that housing vacancies are concentrated to certain submarkets, which means that on these submarkets the vacancy rate can be very high. The submarkets are characteristically neighbourhoods built either during the sities, the so called million homes programme, which often means a less attractive location or appearence, or neighbourhoods built later which often means high rents. The companies handle the vacancies in a way that can be explained by the market models monopolistic competition as well as monopoly. Price adjustments are conducted as different forms of price discrimination, for instance lower rents for young people. THe companies have demolished apartments, which is a quantity adjustment. Demolitions have been used to a surprisingly great extent. Three percent of the total stock of these companies has been demolished during a period of five years. THe statistical analysis shows that a lowered rent has no connection with changes in demand bur it has connection with changes in supply in fomrs of an increased number of apartments in nearby substitute markets, for instance an increase of condominiums and rental apartments owned by other municipal housing companies. Several results of the statistical analyses implies that the market structure is of importance when predicting how a municipal housing company will act in situations demanding price- or quantity adjustments. A theoretically interesting result is that the companies have invented different forms of short-run quantity adjustments, for instance locking one bedroom in a two-bedroom apartment and lease it as a one-bedroom apartment. Among theorists there are different opinions on whether the short run supply curve for housing is fixed or not. The findings here could be an argument against a fixed short run supply curve. The second part of the thesis consists of a literature study. In analysing wellknown papers on vacancies it is found that although "the natural vacancy rate" is an established concept there is need for a definition. Therefore the concept is analysed and defined. Five related vacancy concepts are suggested: 1) observed vacancy rate, 2) natural vacancy rate in short run equilibrium, 3) deviation of vacancy rate in short run equilibrium, 4) natural vacancy rate in long run equilibrium and 5) deviation of natural vacancy rate in long run equilibrium. These concepts are useful in analysing vacancies whether the units are number of apartments or number of weeks. To measure vacancies in time is of great importance to be able to analyse vacancy persistence. QC 20151216

Multipath TCP är en viktig ändring förr TCP, där målet är att låsa upp fördelarna med multipath in ett nätverk genom att dela upp dataöverföring över subflöden, och samtidigt försöka bibehålla bakåtkompabilitet med nuvarande system och infrastruktur. Detta examensarbete är en omfattande säkerhetsutvärdering av Multipath TCP med en djupgående analys av dess främsta sårbarheter, speciellt sårbarheten ADD ADDR som påverkar version 0 av Multipath TCP. Efter en inledande fas bestående av en undersökning och testning av sårbarheten så bestod arbetet främst av utvecklingen av en rad fixar för sårbarheten ADD ADDR. Dessa fixar gjordes för Linuxkärnans implementation av Multipath TCP, i ett första steg mot version 1 av protokollet. Denna rapport innehåller en utvärdering baserad på experiment för varje steg i utvecklingsfasen, samt en slutgiltig prestandaanalys för den modifierade implementationen av Multipath TCP. I processen producerades dels ett förbättringsförslag till det officiella RFC-dokumentet som innehåller specifikationen för Multipath TCP, och även mindre kodändningar till närliggande open-source projekt, exempelvis packet-analyseraren Wireshark. Examensarbetet innehöll mycket interaktion med viktiga open-source grupper, framförallt gruppen för Linuxkärnan. Multipath TCP är ett fortlöpande projekt som är under ständig förändring, både kring protokollet och dess implementation. Detta arbete är ett steg i den övergripande distributionsprocessen, med fokus på säkerhet. Multipath TCP is a major extension for TCP that aims at unlocking multipath benefits in the network by splitting data transferring across multiple subflows, keeping into consideration funda-mental compatibility goals in order to achieve a seamless deployment of the new protocol on current systems and infrastructures. This thesis work is an extensive security evaluation of Multipath TCP, with an in-depth analysis of its major vulnerabilities: in particular, the ADD ADDR vulnerability affecting Multipath TCP version 0 is addressed in this document. After a preliminary part that involves testing and studying the vulnerability itself, the core value of this thesis work concerns the development of a series of patches for the Linux Kernel implementation of Multipath TCP aimed at fixing the ADD ADDR vulnerability and marking the first step towards the new version of the protocol, Multipath TCP version 1. The paper contains an experimental evaluation of the various steps of the development phase, including a final performance analysis for the modified implemen-tation of Multipath TCP. In the process, contributions have been produced for the official RFC documentation containing the specifications for Multipath TCP, together with other minor code contributions for related open-source projects, like the famous packet analyzer Wireshark. The entire thesis work required strong interaction with important open-source communities, especially the Linux Kernel one. Multipath TCP is an ongoing project subjected to constant changes regard-ing the protocol and its implementations: this work is just a single step of the overall deployment process, with a main focus on security.