Synchron - An API and Runtime for Embedded Systems

Programming embedded systems applications involve writing concurrent, event-driven and timing-aware programs. Traditionally, such programs are written in low-level machine-oriented programming languages like C or Assembly. We present an alternative by introducing Synchron, an API that offers high-level abstractions to the programmer while supporting the low-level infrastructure in an associated runtime system and one-time-effort drivers.Embedded systems applications exhibit the general characteristics of being (i) concurrent, (ii) I/O–bound and (iii) timing-aware. To address each of these concerns, the Synchron API consists of three components - (1) a Concurrent ML (CML) inspired message-passing concurrency model, (2) a message-passing–based I/O interface that translates between low-level interrupt based and memory-mapped peripherals, and (3) a timing operator, syncT, that marries CML’s sync operator with timing windows inspired from the TinyTimber kernel.We implement the Synchron API as the bytecode instructions of a virtual machine called SynchronVM. SynchronVM hosts a Caml-inspired functional language as its frontend language, and the backend of the VM supports the STM32F4 and NRF52 microcontrollers, with RAM in the order of hundreds of kilobytes. We illustrate the expressiveness of the Synchron API by showing examples of expressing state machines commonly found in embedded systems. The timing functionality is demonstrated through a music programming exercise. Finally, we provide benchmarks on the response time, jitter rates, memory, and power usage of the SynchronVM

Twin paradox with macroscopic clocks in superconducting circuits

We propose an implementation of a twin paradox scenario in superconducting circuits, with velocities as large as a few percent of the speed of light. Ultrafast modulation of the boundary conditions for the electromagnetic field in a microwave cavity simulates a clock moving at relativistic speeds. Since our cavity has a finite length, the setup allows us to investigate the role of clock size as well as interesting quantum effects on time dilation. In particular, our theoretical results show that the time dilation increases for larger cavity lengths and is shifted due to quantum particle creation.Comment: 6 pages, 3 figures. I. F. previously published as I. Fuentes-Guridi and I. Fuentes-Schulle

En samskapad värld – att kommunicera samskapat värde till kunden

Teknologibaserad självservice (TBSS) är en företeelse som länge funnits i form av bankomater och självservice på bensinmackar. På senare år har detta fenomen även växt sig allt starkare inom detaljhandeln. Syftet med denna uppsats är att utreda hur ett detaljhandelsföretag genom att kommunicera samskapande av värde, som en del av sin identitet, kan påverka hur teknologibaserad självservice emottas av kunden. Som undersökningsobjekt för detta syfte valde vi att studera företaget IKEA, då företagets koncept gör kunden delaktig i produktionsprocessen och de även tagit steget till att implementera teknologibaserad självservice i kassalinjen. Uppsatsen tar utgångspunkt i såväl ett företags- som ett kundperspektiv. Resultatet visar tydliga samband mellan den uppfattning kunden har av samskapat värde som en del i företagets identitet och kundens mottaglighet med avseende på företagets TBSS – erbjudande. Detta tyder på att om ett företag på ett tydligt sätt kan kommunicera samskapat värde som en del i företagets identitet så har detta företag en möjlighet att förbättra kundens inställning till TBSS

Microfluidic genome-wide profiling of intrinsic electrical properties in Saccharomyces cerevisiae

Methods to analyze the intrinsic physical properties of cells – for example, size, density, rigidity, or electrical properties – are an active area of interest in the microfluidics community. Although the physical properties of cells are determined at a fundamental level by gene expression, the relationship between the two remains exceptionally complex and poorly characterized, limiting the adoption of intrinsic separation technologies. To improve our current understanding of how a cell's genotype maps to a measurable physical characteristic and quantitatively investigate the potential of using these characteristics as biomarkers, we have developed a novel screen that combines microfluidic cell sorting with high-throughput sequencing and the haploid yeast deletion library to identify genes whose functions modulate one such characteristic – intrinsic electrical properties. Using this screen, we are able to establish a high-content electrical profile of the haploid yeast gene deletion strains. We find that individual genetic deletions can appreciably alter the electrical properties of cells, affecting [approximately] 10% of the 4432 gene deletion strains screened. Additionally, we find that gene deletions affecting electrical properties in specific ways (i.e. increasing or decreasing effective conductivity at higher or lower electric field frequencies) are strongly associated with an enriched subset of fundamental biological processes that can be traced to specific pathways and complexes. The screening approach demonstrated here and the attendant results are immediately applicable to the intrinsic separations community.Singapore-MIT AllianceNational Science Foundation (U.S.) (NSF IDBR grant DBI-0852654)National Institutes of Health (U.S.) (NIH grant EB005753

Nedskrivningsprövning av goodwill

Syfte: Syftet med kandidatuppsatsen är att beskriva och undersöka hur nedskrivningsprövning av goodwill i enlighet med IAS 36 har gått till och redovisats i fem goodwillintensiva börsnoterade koncerner under perioden 2005 - 2013. Metod: Uppsatsen är utformad som en fallstudie med kvalitativ ansats. Data¬insamlingen består uteslutande av sekundärdata, med ett stort fokus på objektens årsredovisningar. Uppsatsen använder sig inte av intervjuer vilket motiveras med att årsredovisningarna anses som tillräckligt omfattande för att uppfylla studiens syfte. Urvalet föll på de fem börsnoterade koncerner som uppvisade störst andel goodwill i förhållande till sina totala tillgångar på Nasdaq OMX Stockholm Large Cap. Teoretiskt ramverk: Uppsatsens teoretiska ramverk består av de IAS utgivna redovisnings-standarder som används inom börsnoterade koncerners koncernredovisning. Utöver detta används vedertagna företagsekonomiska teorier såsom intressentmodellen, Principal-Agent-teorin och som förlängning av detta, positiv redovisningsteori. Vidare anläggs ett aktiemarknadsperspektiv för att analysera redovisningen. Empiri: Först ges en kort introduktion av undersökningsobjekten och deras förutsättningar. Empirin består av sammanställning och presentation av ekonomiska siffror inhämtade ur samtliga undersökningsobjekts årsredovisningar samt textbaserad data inhämtad ur, för uppsatsen, relevanta noter i samtliga årsredovisningar. De undersökta bolagen är Assa Abloy, Getinge, Meda, Ratos och Securitas. Slutsats: Förvärvstakten har varit hög och goodwillposternas roll har vuxit under perioden 2005 - 2013. Nedskrivningsprocenten har under åren, för samtliga undersökta bolag, varit låga relativt vad de skulle ha varit under tidigare regelverk. Diskonteringsräntorna har inte skiftat märkbart under perioden trots konjunktursvängningar. IAS principbaserade redovisningsstandarder lämnar utrymme för tolkning vilket är negativt för potentiella aktieägare från ett aktiemarknadsperspektiv. För utomstående part är nedskrivningsprövningens redovisning i koncernerna av stor vikt då den kan leda till stor resultatpåverkan för bolag med stor andel goodwill. Redovisningen kring nedskrivnings-prövning är ofta otydlig, inte minst vad det gäller diskonteringsräntor. Vissa bolag redovisar diskonteringsräntor efter skatt och vissa redovisar före skatt. IAS 36 påverkar därför, genom sitt tolkningsutrymme, potentiella aktieägare negativt eftersom goodwill¬redovisningen inte gör tillräckligt mycket för att brygga över den informationsasymmetri som existerar.Purpose: The purpose of the thesis is to describe and investigate how five public groups with significant goodwill have accounted their goodwill impairment testing in accordance with IAS 36 standard during the time period of 2005 - 2013. Methodology: The thesis is shaped as a case study with a qualitative approach. The collection of data consists solely of secondary data collected through annual reports. The thesis does not use any interview methodology motivated by the fact that the authors deem the annual reports as sufficient for the thesis to fulfill its purpose. The selection process consisted of picking the five groups on the Nasdaq OMX Stockholm Large Cap who for the year 2013 presented the highest ratio of goodwill to total assets. Theoretical perspectives: The theoretical perspectives used in the thesis consists of the accounting standards issued by IASB, used by Swedish public groups in their consolidated financial statements. Further business administrative theories are utilized such as stakeholder theory, Principal Agent-theory and as an extension of this, positive accounting theory. A stock market perspective is applied to analyze the accounting methods. The companies included in this study are Assa Abloy, Getinge, Meda, Ratos and Securitas. Empirical foundation: Firstly a short introduction is made of every test subject and its background. The empirical data consists of compilation and presentation of economic data gathered from every test subject's annual report. Also text-based data concerning goodwill relevant accounting is presented from all relevant notes found in the annual reports. Conclusion: The rate of acquisitions has been high and the role of goodwill has grown during the period of 2005 - 2013. The impairment percentage has during the years, in every case, been low relative what it would have been during previous regulations. The discount rates have not shifted notably during the period despite the troughs and peaks in the economy. The principle-based accounting standards of IAS permit room for interpretation, which is negative for potential shareholders according to a stock market-perspective. The accounting of impairment testing is important to external parts in goodwill heavy companies seeing as impairment can lead to a significant effect on the bottom line. The accounting of impairment testing is often ambiguous, especially concerning the discount rates. In some cases they are presented pre tax and in some, post tax. Through its room for interpretation the IAS 36 standard therefore impacts potential shareholders negatively due to the fact that the goodwill accounting does not do enough to offset the existing information asymmetry

Precise positioning of autonomous vehicles combining UWB ranging estimations with on-board sensors

In this paper, we analyze the performance of a positioning system based on the fusion of Ultra-Wideband (UWB) ranging estimates together with odometry and inertial data from the vehicle. For carrying out this data fusion, an Extended Kalman Filter (EKF) has been used. Furthermore, a post-processing algorithm has been designed to remove the Non Line-Of-Sight (NLOS) UWB ranging estimates to further improve the accuracy of the proposed solution. This solution has been tested using both a simulated environment and a real environment. This research work is in the scope of the PRoPART European Project. The different real tests have been performed on the AstaZero proving ground using a Radio Control car (RC car) developed by RISE (Research Institutes of Sweden) as testing platform. Thus, a real time positioning solution has been achieved complying with the accuracy requirements for the PRoPART use case

Converting data-parallelism to task-parallelism by rewrites: purely functional programs across multiple GPUs

High-level domain-specific languages for array processing on the GPU are increasingly common, but they typically only run on a single GPU. As computational power is distributed across more devices, languages must target multiple devices simultaneously. To this end, we present a compositional translation that fissions data-parallel programs in the Accelerate language, allowing subsequent compiler and runtime stages to map computations onto multiple devices for improved performance---even programs that begin as a single data-parallel kernel

Serology assessment of antibody response to SARS-CoV-2 in patients with COVID-19 by rapid IgM/IgG antibody test

The coronavirus disease 2019 (COVID-19) pandemic has created a global health- and economic crisis. Detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes COVID-19 by serological methods is important to diagnose a current or resolved infection. In this study, we applied a rapid COVID-19 IgM/IgG antibody test and performed serology assessment of antibody response to SARS-CoV-2. In PCR-confirmed COVID-19 patients (n = 45), the total antibody detection rate is 92% in hospitalized patients and 79% in non-hospitalized patients. The total IgM and IgG detection is 63% in patients with 2 weeks disease duration; and 91% in hospitalized patients with >2 weeks disease duration. We also compared different blood sample types and suggest a higher sensitivity by serum/plasma over whole blood. Test specificity was determined to be 97% on 69 sera/plasma samples collected between 2016-2018. Our study provides a comprehensive validation of the rapid COVID-19 IgM/IgG serology test, and mapped antibody detection patterns in association with disease progress and hospitalization. Our results support that the rapid COVID-19 IgM/IgG test may be applied to assess the COVID-19 status both at the individual and at a population level. © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Peer reviewe

Achieving High-Performance the Functional Way: A Functional Pearl on Expressing High-Performance Optimizations as Rewrite Strategies

Optimizing programs to run efficiently on modern parallel hardware is hard but crucial for many applications. The predominantly used imperative languages - like C or OpenCL - force the programmer to intertwine the code describing functionality and optimizations. This results in a portability nightmare that is particularly problematic given the accelerating trend towards specialized hardware devices to further increase efficiency. Many emerging DSLs used in performance demanding domains such as deep learning or high-performance image processing attempt to simplify or even fully automate the optimization process. Using a high-level - often functional - language, programmers focus on describing functionality in a declarative way. In some systems such as Halide or TVM, a separate schedule specifies how the program should be optimized. Unfortunately, these schedules are not written in well-defined programming languages. Instead, they are implemented as a set of ad-hoc predefined APIs that the compiler writers have exposed. In this functional pearl, we show how to employ functional programming techniques to solve this challenge with elegance. We present two functional languages that work together - each addressing a separate concern. RISE is a functional language for expressing computations using well known functional data-parallel patterns. ELEVATE is a functional language for describing optimization strategies. A high-level RISE program is transformed into a low-level form using optimization strategies written in ELEVATE . From the rewritten low-level program high-performance parallel code is automatically generated. In contrast to existing high-performance domain-specific systems with scheduling APIs, in our approach programmers are not restricted to a set of built-in operations and optimizations but freely define their own computational patterns in RISE and optimization strategies in ELEVATE in a composable and reusable way. We show how our holistic functional approach achieves competitive performance with the state-of-the-art imperative systems Halide and TVM