30 research outputs found
Bounding the End-to-End Execution Time in Distributed Real-Time Systems: Arguing the case for Deterministic Networks in Lingua Franca
Designing and implementing distributed systems with real-time requirements quickly reveal the complexity of handling time and logic across multiple systems. As data traverse a network, it is subjected to variable delay due to interfering traffic and variable load on network components. This introduces an element of non-determinism in execution time for distributed algorithms, which translates into increased error logic and pessimistic worst-case estimates. Over the next few years, it is expected that Cyber-Physical Systems will see many new use cases, and the network connecting these will play an ever more important role. Combined with the onset of the fourth industrial revolution, IEEEs Time Sensitive Networking, IETFs Deterministic Networking, and 3GPPs Ultra Reliable Low Latency profile will play a vital role in realizing these systems. Coordination languages such as Lingua Franca can offer a substantial contribution to the design process and implementation of distributed systems such as Cyber-Phyiscal Systems, both through its model of computation which elevates time to a first-class citizen and with its support for distributed models. In this paper, we show that by introducing deterministic network channels with a fixed delay, the worst-case execution time is not increased whereas the variance in total execution time from start to finish is greatly reduced. For a coordination language such as LF, this means that we can analyze a system using much tighter delay bounds for network traffic, which in turn can yield better resource utilization.publishedVersio
Kartlegging av grønnstruktur i bebygde områder - Datagrunnlag og metodikk for fremstilling av et nasjonalt grønnstrukturkart
Rapporten dokumenterer datagrunnlaget og metodikken bak NIBIOs nasjonale kartlegging av grønnstruktur i og rundt bebygde områder. Grønnstruktur er per nå dårlig dokumentert og ikke systematisk kartlagt i Norge. Informasjon om disse arealene er viktig for analyser knyttet til klimatilpasning, arealplanlegging og arealforvaltning. For en nasjonal kartlegging beskriver rapporten bruk av fjernmåling fra satellitt og fly for å detektere grønnstruktur samt inndeling av grønnstruktur i tre sjiktklasser. Nøyaktigheten av grønnstrukturkartet er dokumentert ved tre kommuner (Drammen, Ullensvang, Bodø). Grønnstrukturkartet har høy nytteverdi innenfor kommunal planlegging; noen eksempler presenteres. Rapporten anbefaler videreutvikling iht. til teknologiutviking og kartografi.Kartlegging av grønnstruktur i bebygde områder - Datagrunnlag og metodikk for fremstilling av et nasjonalt grønnstrukturkartpublishedVersio
Feasibility of single-cell analysis of model cancer and foetal cells in blood after isolation by cell picking
The objective of the present feasibility study was to transfer single cell line cells to either microscopy slides for downstream immune characterization or to polymerase chain reaction tubes for downstream DNA quantitation. Tumour cell lines, SKBR3 and MCF7 and trophoblast cell line JEG-3 were spiked in healthy donor blood. The CytoTrack system was used to scan the spiked blood samples to identify target cells. Individual target cells were identified, picked by use of a CytoPicker and deposited to either a microscopic slide or a polymerase chain reaction tube (PCR). Single tumour cells on microscopic slides were further immunostained with human epidermal growth factor receptor 2 (Her2) and epithelial cell adhesion molecule (EpCAM). From the picked cells in polymerase chain reaction tubes, DNA was amplified, quantified and used for Short Tandem Repeat genotyping. Depositing rare cells to microscopy slides was laborious with only five cells per hour. In this study with a trained operator, the picked cells had an 80.5% recovery rate. Depositing single trophoblast cells in PCR tubes was a faster process with 10 cells in 5 min. Immunostaining of isolated cells by both Her2 and EpCAM was possible but showed varying staining intensity. Presence of trophoblasts and contaminating white blood cells in PCR tubes after cell picking was confirmed based on DNA yield and mixed Short Tandem Repeat profiles in five out of eight samples. Using the CytoPicker tool, single tumour and trophoblast cells were successfully isolated and moved from blood samples, allowing subsequent immunostaining or Short Tandem Repeat genotyping
Using Smart Cards to Mitigate Security Threats on Mobile Devices
This master thesis developed and tested the idea that smart cards are able to help mitigate security threats on mobile devices that are handling sensitive data. Investigating the limitations of smart cards is a fundamental part of the idea and we performed in-depth testing and analysis of what smart cards are capable of. Our study shows that smart cards are limited by their low processing power, low amount of memory and a severely lacking application programming language. These limitations affect smart cards usefulness concerning cryptography and data processing. Additionally, lack of standard support for smart cards in modern mobile operating systems is a limitation we investigate and propose solutions for. Despite these limitations, smart cards can still be a useful asset as they offer a secure execution environment and are tamper resistant. Viable use cases include secure key generation, management and storage, digital signing, encryption, strong authentication and the possibility to run small specialized applets securely. More complex use cases are also possible, but require additional external components and infrastructure to be realized. For instance, a smart card could be used as a simple policy enforcement point, given that we had a trusted third party available, and a functioning public key infrastructure in place. We were able to construct an Android library and a smart card applet for secure communication, but there still remains research on the topic. Not all functionality were implemented due to time constraints and technical issues, but the framework foundations are in place so that extensions can be quickly and easily implemented. Future work may include full scale testing of our framework, additional development and testing on more technological advanced smart cards
net_chan: Deterministic network channels for distributed real-time systems
Network Channels (net_chan) is an open-source library that provides a network construct for deterministic channels between systems in distributed systems. net_chan is built to harness the Quality of Service guarantees offered by Time Sensitive Networking and the clock accuracy provided by the Precision Time Protocol. The software provides a simple and intuitive API for building distributed systems over packet-switched networks. When run on a system with a deterministic Linux kernel, the system provides an accurate synchronization mechanism between applications running on different hosts
Veien mot prosessorientering : en studie av utfordringer og resultater
Oppgaven hadde til hensikt å studere de utfordringene virksomheter møter, på veien mot å orientere verdiskapingen langs horisontale prosesser. Videre ønsket vi også å bidra til å synliggjøre hvilke resultater som kan forventes av å jobbe prosessorientert. Vi utviklet et analyseverktøy, i form av en kvantitativ selvevaluering, som evner å kartlegge hvor langt virksomheter er kommet innen ulike områder av prosessarbeidet. Verktøyet ble applisert på 102 norske virksomheter, som rettet seg mot forbrukermarkedet. Analyser av resultatene viste at små virksomheter var mindre prosessutviklet enn de større. Måling av prosessenes prestasjoner og bruk av disse dataene til systematisk forbedring var et område mange var kommet veldig kort på. Blant de som hadde kommet ganske langt innen prosessorientert ledelse var rollekonflikt mellom prosesseiere og linjeledere et utbredt problem. Studien ga også empiriske indikasjoner på at det å jobbe prosessorientert kan føre til mer fornøyde kunder og danner grunnlag for videre forskning innen et svært sentralt emne på fagfeltet
AR50 – Arealressurskart i målestokk 1:50 000. Et heldekkende arealressurskart for jord- og skogbruk
AR50 er et heldekkende kart over arealressurser på Fastlands-Norge med øyer. Denne rapporten beskriver metoden som er brukt for å fremstille kartet og peker på bruksområder.publishedVersio
AR50 – Arealressurskart i målestokk 1:50 000. Et heldekkende arealressurskart for jord- og skogbruk
AR50 er et heldekkende kart over arealressurser på Fastlands-Norge med øyer. Denne rapporten beskriver metoden som er brukt for å fremstille kartet og peker på bruksområder