| 1. |
- Blanch, Krister, 1991
(författare)
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Beyond-application datasets and automated fair benchmarking
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Beyond-application perception datasets are generalised datasets that emphasise the fundamental components of good machine perception data. When analysing the history of perception datatsets, notable trends suggest that design of the dataset typically aligns with an application goal. Instead of focusing on a specific application, beyond-application datasets instead look at capturing high-quality, high-volume data from a highly kinematic environment, for the purpose of aiding algorithm development and testing in general. Algorithm benchmarking is a cornerstone of autonomous systems development, and allows developers to demonstrate their results in a comparative manner. However, most benchmarking systems allow developers to use their own hardware or select favourable data. There is also little focus on run time performance and consistency, with benchmarking systems instead showcasing algorithm accuracy. By combining both beyond-application dataset generation and methods for fair benchmarking, there is also the dilemma of how to provide the dataset to developers for this benchmarking, as the result of a high-volume, high-quality dataset generation is a significant increase in dataset size when compared to traditional perception datasets. This thesis presents the first results of attempting the creation of such a dataset. The dataset was built using a maritime platform, selected due to the highly dynamic environment presented on water. The design and initial testing of this platform is detailed, as well as as methods of sensor validation. Continuing, the thesis then presents a method of fair benchmarking, by utilising remote containerisation in a way that allows developers to present their software to the dataset, instead of having to first locally store a copy. To test this dataset and automatic online benchmarking, a number of reference algorithms were required for initial results. Three algorithms were built, using the data from three different sensors captured on the maritime platform. Each algorithm calculates vessel odometry, and the automatic benchmarking system was utilised to show the accuracy and run-time performance of these algorithms. It was found that the containerised approach alleviated data management concerns, prevented inflated accuracy results, and demonstrated precisely how computationally intensive each algorithm was.
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| 2. |
- Bengtsson, Lars, 1963
(författare)
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Mikrodatorteknik
- 1995
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Första delen behandlar Microchips "Base-line"-kretsar och andra delen behandlar "Midrange"-kretsarna. De flesta funktioner belyses med konstruktionsexempel. Exempel och övningar är mycket hårdvarunära och boken behandlar konstruktion av mikrodatorer från grunden. Boken är avsedd för kurser i mikrodatorteknik på högskolan eller annan högre teknisk utbildning, men kan även användas som självstudiematerial eftersom de flesta exempel ges med detaljerade och verifierade lösningar av såväl hård- som mjukvaran. Tidigare erfarenhet av assemblerprogrammering är inte nödvändig men grundläggande kunskaper i digitalteknik förutsätts. Boken kan med fördel också läsas av rutinerade assemblerprogrammerare som vill veta hur prestanda hos de nya RISC-baserade PIC-controllerna står sig i konkurrensen med de mer etablerade enchipscontrollerna, t ex HC11 och 8751, som bygger på traditionell CISC-arkitektur.
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| 3. |
- Al Nahas, Beshr, 1985, et al.
(författare)
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Low-power listening goes multi-channel
- 2014
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Ingår i: Proceedings - IEEE International Conference on Distributed Computing in Sensor Systems, DCOSS 2014. ; , s. 2-9
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Konferensbidrag (refereegranskat)abstract
- Exploiting multiple radio channels for communication has been long known as a practical way to mitigate interference in wireless settings. In Wireless Sensor Networks, however, multi-channel solutions have not reached their full potential: the MAC layers included in TinyOS or the Contiki OS for example are mostly single-channel. The literature offers a number of interesting solutions, but experimental results were often too few to build confidence. We propose a practical extension of low-power listening, MiCMAC, that performs channel hopping, operates in a distributed way, and is independent of upper layers of the protocol stack. The above properties make it easy to deploy in a variety of scenarios, without any extra configuration/scheduling/channel selection hassle. We implement our solution in Contiki and evaluate it in a 97-node~testbed while running a complete, out-of-the-box low-power IPv6 communication stack (UDP/RPL/6LoWPAN). Our experimental results demonstrate increased resilience to emulated WiFi interference (e.g., data yield kept above 90% when Contiki MAC drops in the 40% range). In noiseless environments, MiCMAC keeps the overhead low in comparison to Contiki MAC, achieving performance as high as 99% data yield along with sub-percent duty cycle and sub-second latency for a 1-minute inter-packet interval data collection. © 2014 IEEE.
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| 4. |
- Bengtsson, Lars, 1963
(författare)
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Embedded Measurement Systems
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The subject of Embedded Measurement Systems (EMS) is the merging of embedded systems and electrical measurement systems. This indicates that EMSs are hardware-software systems dedicated to measuring one or a few physical quantities. Applications are numerous; EMSs measure the temperature in refrigerators, freezers, irons, ovens and automobile combustion engines, they sense vibrations in tilt alarms and game consoles, they measure airflow in engines and ventilation systems, they measure shock impact in crash detectors and are used as shock and temperature loggers for transport goods, they measure air pressure in airplane cabins, humidity in air-conditioned environments, they measure liquid levels in fuel tanks, they detect smoke in fire alarms, they measure the viscosity of lubricant oil in engines, they measure the rotation speed of spinning wheels (in any engine), they measure torque in engines and are used as heart rate and ECG detectors in medicine etc. The commercial demand for ever cheaper products and worldwide environmental legislations force vendors to continuously look for more cost-efficient and less power-consuming solutions for their embedded measurement systems. This thesis is concerned most of all with the implementation of cost-efficient/low-power measurement systems in embedded controllers. This includes some novel ideas in voltage, time and resistance measurements with embedded controllers and it will demonstrate how these quantities, analog in nature, can be measured accurately and precisely by inherently digital embedded controllers.
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| 5. |
- Yanggratoke, Rerngvit, 1983-
(författare)
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Data-driven Performance Prediction and Resource Allocation for Cloud Services
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cloud services, which provide online entertainment, enterprise resource management, tax filing, etc., are becoming essential for consumers, businesses, and governments. The key functionalities of such services are provided by backend systems in data centers. This thesis focuses on three fundamental problems related to management of backend systems. We address these problems using data-driven approaches: triggering dynamic allocation by changes in the environment, obtaining configuration parameters from measurements, and learning from observations. The first problem relates to resource allocation for large clouds with potentially hundreds of thousands of machines and services. We developed and evaluated a generic gossip protocol for distributed resource allocation. Extensive simulation studies suggest that the quality of the allocation is independent of the system size for the management objectives considered.The second problem focuses on performance modeling of a distributed key-value store, and we study specifically the Spotify backend for streaming music. We developed analytical models for system capacity under different data allocation policies and for response time distribution. We evaluated the models by comparing model predictions with measurements from our lab testbed and from the Spotify operational environment. We found the prediction error to be below 12% for all investigated scenarios.The third problem relates to real-time prediction of service metrics, which we address through statistical learning. Service metrics are learned from observing device and network statistics. We performed experiments on a server cluster running video streaming and key-value store services. We showed that feature set reduction significantly improves the prediction accuracy, while simultaneously reducing model computation time. Finally, we designed and implemented a real-time analytics engine, which produces model predictions through online learning.
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| 6. |
- Åkerberg, Johan, et al.
(författare)
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Design challenges and objectives in industrial wireless sensor networks
- 2017
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Ingår i: Industrial Wireless Sensor Networks: Applications, Protocols, and Standards. - Boca Raton : CRC Press. - 9781466500525 - 9781466500518 ; , s. 79-100
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In recent years the advances in wireless sensor networks have grown exponentially and WSNs have been deployed in diverse application areas such as agriculture, disaster management, intelligent transport systems, and industrial automation. In industrial automation, wireless sensor networks have so far mostly been considered within building automation, factory automation, and process automation in order to save cost in cable reduction and maintenance but also improved flexibility [14]. Recently, wireless sensor networks for smart grid applications have been discussed. Several market forecasts have recently predicted exponential growths in the sensor market over the next few years, resulting in a multi-billion dollar market in the near future. For instance, ABI research [18] predicts that in 2015 around 645 million IEEE 802.15.4 chipsets will be shipped and that the worldwide market for automation systems in process industries will grow to roughly $150 billion.
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| 7. |
- Shafiq, ur Réhman, 1978-, et al.
(författare)
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Using Vibrotactile Language for Multimodal Human Animals Communication and Interaction
- 2014
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Ingår i: Proceedings of the 2014 Workshops on Advances in Computer Entertainment Conference, ACE '14. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450333146 ; , s. 1:1-1:5
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Konferensbidrag (refereegranskat)abstract
- In this work we aim to facilitate computer mediated multimodal communication and interaction between human and animal based on vibrotactile stimuli. To study and influence the behavior of animals, usually researchers use 2D/3D visual stimuli. However we use vibrotactile pattern based language which provides the opportunity to communicate and interact with animals. We have performed experiment with a vibrotactile based human-animal multimodal communication system to study the effectiveness of vibratory stimuli applied to the animal skin along with audio and visual stimuli. The preliminary results are encouraging and indicate that low-resolution tactual displays are effective in transmitting information.
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| 8. |
- Rosenstatter, Thomas, et al.
(författare)
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Modelling the Level of Trust in a Cooperative Automated Vehicle Control System
- 2018
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Ingår i: IEEE transactions on intelligent transportation systems (Print). - Piscataway, NJ : IEEE Press. - 1524-9050 .- 1558-0016. ; 19:4, s. 1267-1247
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Tidskriftsartikel (refereegranskat)abstract
- Vehicle-to-vehicle communication is a key technology for achieving increased perception for automated vehicles, where the communication enables virtual sensing by means of sensors in other vehicles. In addition, this technology also allows detection and recognition of objects that are out-of-sight. This paper presents a trust system that allows a cooperative and automated vehicle to make more reliable and safe decisions. The system evaluates the current situation and generates a trust index indicating the level of trust in the environment, the ego vehicle, and the surrounding vehicles. This research goes beyond secure communication and concerns the verification of the received data on a system level. The results show that the proposed method is capable of correctly identifying various traffic situations and how the trust index is used while manoeuvring in a platoon merge scenario.
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| 9. |
- Selvaraj, Yuvaraj, 1990
(författare)
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On Provably Correct Decision-Making for Automated Driving
- 2020
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The introduction of driving automation in road vehicles can potentially reduce road traffic crashes and significantly improve road safety. Automation in road vehicles also brings several other benefits such as the possibility to provide independent mobility for people who cannot and/or should not drive. Many different hardware and software components (e.g. sensing, decision-making, actuation, and control) interact to solve the autonomous driving task. Correctness of such automated driving systems is crucial as incorrect behaviour may have catastrophic consequences. Autonomous vehicles operate in complex and dynamic environments, which requires decision-making and planning at different levels. The aim of such decision-making components in these systems is to make safe decisions at all times. The challenge of safety verification of these systems is crucial for the commercial deployment of full autonomy in vehicles. Testing for safety is expensive, impractical, and can never guarantee the absence of errors. In contrast, formal methods , which are techniques that use rigorous mathematical models to build hardware and software systems can provide a mathematical proof of the correctness of the system. The focus of this thesis is to address some of the challenges in the safety verification of decision-making in automated driving systems. A central question here is how to establish formal verification as an efficient tool for automated driving software development. A key finding is the need for an integrated formal approach to prove correctness and to provide a complete safety argument. This thesis provides insights into how three different formal verification approaches, namely supervisory control theory, model checking, and deductive verification differ in their application to automated driving and identifies the challenges associated with each method. It identifies the need for the introduction of more rigour in the requirement refinement process and presents one possible solution by using a formal model-based safety analysis approach. To address challenges in the manual modelling process, a possible solution by automatically learning formal models directly from code is proposed.
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| 10. |
- Lv, Zhihan, Dr. 1984-, et al.
(författare)
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Editorial : 5G for Augmented Reality
- 2022
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Ingår i: Mobile Networks and Applications. - : Springer. - 1383-469X .- 1572-8153.
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Tidskriftsartikel (refereegranskat)
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