Tensor Completion for Radio Map Reconstruction using Low Rank and Smoothness

Radio maps are important enablers for many applications in wireless networks, ranging from network planning and optimization to fingerprint based localization. Sampling the complete map is prohibitively expensive in practice, so methods for reconstructing the complete map from a subset of measurements are increasingly gaining attention in the literature. In this paper, we propose two algorithms for this purpose, which build on existing approaches that aim at minimizing the tensor rank while additionally enforcing smoothness of the radio map. Experimental results with synthetic measurements derived via ray tracing show that our algorithms outperform state of the art techniques

Comparing scripts and scripting comparisons: toward a systematic analysis of technologically mediated influence

While it is generally accepted in Science and Technology Studies that technological artefacts have an impact on human practices, the question how this impact is achieved has been answered idiosyncratically for each case studied. This gap between abstract theoretical conceptualisations of non-human agency and largely descriptive accounts of many empirical instances to which they are applied is difficult to overcome unless the agency of artefacts can be compared. The aim of this paper is to propose and test a theoretically grounded framework that enables comparisons of agential qualities of technologies. In order to compare the ways in which technologies influence human behaviour, technology needs to be positioned in social theory. We do so by arguing that technology is one of three distinct modes of exercising influence, positioning technology in a general framework of kinds and modes of influence, and utilising Akrich's notion of scripts to capture the mediation of influence as a particular property of technology. From this, we derive a framework for comparing scripts in seven dimensions. We apply this framework to a test of conflicting hypotheses about consequences of the increasing sophistication of technology and to the exploration of the complexity underlying a typology of ‘persuasive technologies’. Our ‘proof of concept’ enables the conclusion that comparative studies of technologies enable unique contributions to Science and Technology Studies as well as related fields like studies on technoregulation.Die Science and Technology Studies sind sich zwar darin einig, dass Technik menschliche Praktiken beeinflusst, geben jedoch bislang auf die Frage, wie das geschieht, für jeden untersuchten Fall eine idiosynkratische Antwort. Diese Lücke zwischen abstrakten Konzeptualisierungen nichtmenschlicher Agency und Einzelfallbeschreibungen kann nicht überwunden werden, solange die Agency von Artefakten nicht verglichen werden kann. Das Ziel dieses Papers ist es, einen theoretisch begründeten Vergleichsrahmen für handlungsbeeinflussende Eigenschaften von Technik vorzuschlagen und zu testen. Um Formen der Beeinflussung menschlichen Verhaltens durch Technik vergleichen zu können, muss letztere in die Sozialtheorie eingeordnet werden. Wir tun das, indem wir Technik in einen allgemeinen Rahmen von Arten und Modi der Beeinflussung einordnen und Akrichs Konzept des Skripts für die Erfassung der handlungsbeeinflussenden Eigenschaften von Technik nutzen. Daraus entwickeln wir einen Vergleichsrahmen für Skripte mit sieben Dimensionen. Diesen Vergleichsrahmen wenden wir in einem Test einander widersprechender Hypothesen über Folgen einer steigenden Komplexität der Technik sowie in der Erkundung der Komplexität einer Typologie von 'Beeinflussungstechnologien' an. Unsere 'Pilotstudie' gestattet die Schlussfolgerung, dass vergleichende Studien von Technologien neuartige Beiträge zu den Science and Technology Studies sowie zu angrenzenden Gebieten wie den Studien zur Techno-Regulation ermöglichen

Technik vergleichen: ein Analyserahmen für die Beeinflussung von Arbeit durch Technik

Wenn eine Aufgabe der Arbeitssoziologie darin besteht, einen Zusammenhang zwischen spezifischen Technologien und den Effekten ihres Einsatzes für Arbeit herzustellen, dann muss sie Technik vergleichend beschreiben. Das Ziel unseres Beitrages besteht darin, der Arbeitssoziologie einen Analyserahmen für Technik anzubieten, der vergleichende empirische Untersuchungen und die Formulierung theoretisch gehaltvoller Aussagen auf mittleren Abstraktionsebenen unterstützen soll. Wir positionieren technikvermittelte Beeinflussung in der Sozialtheorie als eine dritte Form der Beeinflussung neben interaktiver und strukturvermittelter Beeinflussung. Für die vergleichende Analyse solcher Beeinflussungen lässt sich das in den Science and Technology Studies entwickelte Konzept des Skripts nutzen. Vergleichsdimensionen für Skripte lassen sich aus allgemeinen Merkmalen von Beeinflussungssituationen ableiten. Wir demonstrieren die Anwendung des Vergleichsrahmens durch die Beantwortung der Frage, wie drei Installationsprogramme für verschiedene Versionen des Betriebssystems Linux die Handlungen der NutzerInnen beeinflussen. Durch den Vergleich der Skripte fokussiert unser Vergleichsrahmen bislang auf Beeinflussungsintentionen. Eine Ausweitung auf den Vergleich situativer Techniknutzung scheint aber möglich.If the sociology of work wants to discover links between specific technologies and their effects on work, it needs to comparatively analyse technologies. The aim of our contribution is to offer a comparative framework for technologies that enables comparative empirical investigations and the formulation of contributions to middle-range theories. We position technologically mediated influence as a third form of exercising influence besides interactive and structurally mediated influence. The comparative analysis of this form of influence can be based on the concept of a script, which has been developed in science and technology studies. Dimensions for the comparison of scripts can be derived from general properties of situations in which influence is exercised. We apply our comparative framework to three installation programmes for different versions of the Linux operating system and answer the question as to how these programmes influence the actions of users. Since it compares scripts, our framework focuses on the intentions of designers so far. However, an extension to the comparison of situated uses of technology seems possible

Berlin V2X: A Machine Learning Dataset from Multiple Vehicles and Radio Access Technologies

The evolution of wireless communications into 6G and beyond is expected to rely on new machine learning (ML)-based capabilities. These can enable proactive decisions and actions from wireless-network components to sustain quality-of-service (QoS) and user experience. Moreover, new use cases in the area of vehicular and industrial communications will emerge. Specifically in the area of vehicle communication, vehicle-to-everything (V2X) schemes will benefit strongly from such advances. With this in mind, we have conducted a detailed measurement campaign that paves the way to a plethora of diverse ML-based studies. The resulting datasets offer GPS-located wireless measurements across diverse urban environments for both cellular (with two different operators) and sidelink radio access technologies, thus enabling a variety of different studies towards V2X. The datasets are labeled and sampled with a high time resolution. Furthermore, we make the data publicly available with all the necessary information to support the onboarding of new researchers. We provide an initial analysis of the data showing some of the challenges that ML needs to overcome and the features that ML can leverage, as well as some hints at potential research studies.Comment: 5 pages, 6 figures. Accepted for presentation at IEEE conference VTC2023-Spring. Available dataset at https://ieee-dataport.org/open-access/berlin-v2

Evacetrapib and Cardiovascular Outcomes in High-Risk Vascular Disease

BACKGROUND: The cholesteryl ester transfer protein inhibitor evacetrapib substantially raises the high-density lipoprotein (HDL) cholesterol level, reduces the low-density lipoprotein (LDL) cholesterol level, and enhances cellular cholesterol efflux capacity. We sought to determine the effect of evacetrapib on major adverse cardiovascular outcomes in patients with high-risk vascular disease. METHODS: In a multicenter, randomized, double-blind, placebo-controlled phase 3 trial, we enrolled 12,092 patients who had at least one of the following conditions: an acute coronary syndrome within the previous 30 to 365 days, cerebrovascular atherosclerotic disease, peripheral vascular arterial disease, or diabetes mellitus with coronary artery disease. Patients were randomly assigned to receive either evacetrapib at a dose of 130 mg or matching placebo, administered daily, in addition to standard medical therapy. The primary efficacy end point was the first occurrence of any component of the composite of death from cardiovascular causes, myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina. RESULTS: At 3 months, a 31.1% decrease in the mean LDL cholesterol level was observed with evacetrapib versus a 6.0% increase with placebo, and a 133.2% increase in the mean HDL cholesterol level was seen with evacetrapib versus a 1.6% increase with placebo. After 1363 of the planned 1670 primary end-point events had occurred, the data and safety monitoring board recommended that the trial be terminated early because of a lack of efficacy. After a median of 26 months of evacetrapib or placebo, a primary end-point event occurred in 12.9% of the patients in the evacetrapib group and in 12.8% of those in the placebo group (hazard ratio, 1.01; 95% confidence interval, 0.91 to 1.11; P=0.91). CONCLUSIONS: Although the cholesteryl ester transfer protein inhibitor evacetrapib had favorable effects on established lipid biomarkers, treatment with evacetrapib did not result in a lower rate of cardiovascular events than placebo among patients with high-risk vascular disease. (Funded by Eli Lilly; ACCELERATE ClinicalTrials.gov number, NCT01687998 .)

Skadade fotbollsspelares uppfattning om fysioterapeutens insats och betydelse under en rehabiliteringsperiod : En enkätstudie

Bakgrund: Fotbollsspelare löper hög risk att drabbas av skada. Det finns tendens att återvända för tidigt till fullt fotbollsutövande innan skadan är helt läkt och utan att en adekvat rehabilitering har utförts. Utförs rehabilitering med hjälp av en fysioterapeut som besitter god kunskap inom området kan skadans läkningsprocess stimuleras. Fysioterapeutiska insatser under hela skadeförloppet kan ge fotbollsspelare bättre förutsättningar till en lyckad rehabilitering. Syfte: Syftet med studien var att undersöka skadade fotbollsspelares uppfattning om fysioterapi och fysioterapeutiska insatser under en rehabiliteringsperiod. Metod: Kvantitativ tvärsnittsstudie för kartläggning av populationen fotbollsspelare i division I i Norrland. Retrospektiv data samlades in med egenkonstruerad webbenkät som skickades ut till 130 personer varav 62 besvarade den. Bortfall gjorde att 57 personer inkluderades i studien. Insamlad data analyserades deskriptivt. Resultat: Majoriteten av deltagarna använde fysioterapi under en rehabiliteringsperiod. Fotbollsspelarna uppgav att tillgång till en annan yrkesgrupp var den vanligaste orsaken till utebliven fysioterapi. Deltagarna framhävde även att fysioterapeutens övervägande uppgifter var manuella behandlingar och upprättning av rehabiliteringsprogram. 13,6 % uppgav att fysioterapeutiska insatser förekom i både akuta och subakuta skedet. Konklusion: Resultatet av studien visar att fotbollsspelares värdering och användning av fysioterapi är hög. Fysioterapeutens närvaro under hela skadeförloppet behöver utvecklas för att ge fotbollsspelare bättre förutsättningar att återgå till full fotbollsaktivitet och förhindra återfall av tidigare skada. Studien ger en indikation på fotbollsspelares uppfattning avseende fysioterapi och fysioterapeutiska insatser. Fler studier bör göras som inkluderar fler fotbollsspelare för att på det viset kartlägga en större population.

A transmission protocol for fully automated valet parking using DSRC

Some of the most advanced functions in automated vehicles are in the parking domain, since it provides structured environments and slow speeds. As most parking garages deny GNSS reception, vehicles rely on dead reckoning or simple path-finding algorithms. To this regard, we have developed an infrastructure-based positioning system using cameras. In this paper, we present a novel approach on how to utilize dedicated short-range communication (often referred to as "Car-2-X communication" (C2X)) to transmit external positioning to vehicles with low latency. A session-based distributed state machine protocol for automated driving is used to ensure synchronicity between vehicle and infrastructure

Identification of vehicle tracks and association to wireless endpoints by multiple sensor modalities

Vehicular positioning technologies enable a broad range of applications and services such as navigation systems, driver assistance systems and self-driving vehicles. However, Global Navigation Satellite Systems (GNSS) do not work in enclosed areas such as parking garages. For these scenarios, a wide range of indoor positioning technologies are available inside the vehicle (internal) and based on infrastructure (external)

Early Fusion of Camera and Lidar for robust road detection based on U-Net FCN

Automated vehicles rely on the accurate and robust detection of the drivable area, often classified into free space, road area and lane information. Most current approaches use monocular or stereo cameras to detect these. However, LiDAR sensors are becoming more common and offer unique properties for road area detection such as precision and robustness to weather conditions. We therefore propose two approaches for a pixel-wise semantic binary segmentation of the road area based on a modified U-Net Fully Convolutional Network (FCN) architecture. The first approach UView-Cam employs a single camera image, whereas the second approach UGrid-Fused incorporates a early fusion of LiDAR and camera data into a multi-dimensional occupation grid representation as FCN input. The fusion of camera and LiDAR allows for efficient and robust leverage of individual sensor properties in a single FCN. For the training of UView-Cam, multiple publicly available datasets of street environments are used, while the UGrid-Fused is trained with the KITTI dataset. In the KITTI Road/Lane Detection benchmark, the proposed networks reach a MaxF score of 94.23% and 93.81% respectively. Both approaches achieve realtime performance with a detection rate of about 10 Hz

GPU-accelerated partially linear multiuser detection for 5G and beyond URLLC systems

In this feasibility study, we have implemented a recently proposed partially linear multiuser detection algorithm in reproducing kernel Hilbert spaces (RKHSs) on a GPU-accelerated platform. Partially linear multiuser detection, which combines the robustness of linear detection with the power of nonlinear methods, has been proposed for a massive connectivity scenario with the non-orthogonal multiple access (NOMA). This is a promising approach, but detecting payloads within a received orthogonal frequency division multiplexing (OFDM) radio frame requires the execution of a large number of inner product operations, which are the main computational burden of the algorithm. Although inner-product operations consist of simple kernel evaluations, their vast number poses a challenge in ultra-low latency (ULL) applications, because the time needed for computing the inner products might exceed the sub-millisecond latency requirement. To address this problem, this study demonstrates the acceleration of the inner-product operations through massive parallelization. The result is a GPU-accelerated real-time OFDM receiver that enables sub-millisecond latency detection to meet the requirements of 5th generation (5G) and beyond ultra-reliable and low latency communications (URLLC) systems. Moreover, the parallelization and acceleration techniques explored and demonstrated in this study can be extended to many other signal processing algorithms in Hilbert spaces, such as those based on projection onto convex sets (POCS) and adaptive projected subgradient method (APSM) algorithms. Experimental results and comparisons with the state-of-art confirm the effectiveness of our techniques.Comment: submitted to IEEEAcces