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Design and Implementation of an AMBA CHI-Compliant Snoop Cache Coherence Controller
No full textIn a multi-processor system, efficient cache coherence mechanisms are important for ensuring that data in every cache remains up-to-date across different cores. The AMBA Coherent Hub Interface (CHI) is a high-performance, scalable protocol designed by ARM to address the challenges of modern system-on-chip (SoC) architectures. This thesis presents the design and implementation of a snoop cache coherence controller using the AMBA CHI protocol. The snoop cache coherence controller is not only to ensure data consistency among the processors but also to reduce the network traffic through the snoop filter in the controller. In this thesis, we designed and implemented a cache coherence controller in hardware description language (HDL), and we used a multi-processor simulator named Multi- CacheSim and SPLASH-3 benchmark to model and test two kinds of snoop filters, counting stream register and cache-like snoop filter, and evaluate their message filter rate which represents the performance in snoop traffic reduction. The results demonstrate that the snoop-based CHI-compliant coherence controller can effectively maintain cache coherence in a multi-processor system based on CHI architecture. Additionally, the cache-like snoop filter can reduce network traffic. By comparing the results of the snoop filters, we can conclude that in most cases, the cache-like snoop filter performs better than the snoop filter based on a stream register. However, both have their advantages, with each performing better under certain circumstances
Smart Maintenance implementation in a TPM based manufacturing company - Developing a strategy for the combination of Smart Maintenance and TPM
No full textThis study investigates the possibility and implications of combining Smart Maintenance and Total Productive Maintenance (TPM) in a factory that works with TPM. The study is conducted at the Volvo Trucks factory in Tuve. The main objective is to create two roadmaps that combine both strategies. The first roadmap will be tailored to academia with the precondition of maturity in TPM. The second roadmap will be tailored to the needs of Volvo Tuve. Through rigorous work with interviews and thematic coding, a current state analysis is presented. This shows the level of maturity Volvo has reached in TPM. Combined with the investigation of the two concepts, which gave the gap between TPM and Smart maintenance. The investigation gave the necessary information to create the roadmaps that have the potential to raise equipment reliability, reduce costs, and strengthen the competitive advantage
Fixed-wing UAVs in Windy Environments: A Circular Delivery System
No full textAbstract
In some situations, when delivering packages with a fixed-wing UAV, a better accuracy is necessary than can be achieved with a fly-by drop. One alternative method is to circle close to the target point with the package suspended below the UAV with a rope. Through simulations it is shown that this circular method can deliver packages with a higher precision than can be done with the fly-by method. In steady wind conditions, it is proven possible to get a close estimation for where the package would land, were it to be released. This is done by a combination of an analytical solution to a system of differential equations in conjunction with a disturbance function based on previous simulations. In isolation, the impact of the turbulence can be minimized by releasing the package from as low a height as possible, and with a low relative velocity between the wind and the package in the horizontal plane at
release. Contrary to that, when combining the estimation with the circular delivery method, the headwind releases gives a higher accuracy. For headwind drops the algorithm can land within 1m of the target approximately 94 to 95 % of the time for wind velocities up to 10m/s. This is significantly better than the fly-by algorithm, which can with 95 % certainty land only within 4m of the target for a similar wind. For even stronger winds the accuracy decreases and for 15m/s wind the circular algorithm can land within one meter with approximately 61 to 69 % probability. Compared to the fly-by, the package also has a lower velocity when it lands, when released with the circular delivery method. The 95th-percentile velocities are 9m/s
and 8m/s respectively. One drawback with the circular algorithm, however, is that it takes longer time before the package is released, with an approximate time of 3 min on average compared to 10 s for the fly-by
Attic conversions as an environmental and profitable urban strategy from empty attics to sustainable homes
No full textAs cities grow and sustainability demands increase, the construction sector faces the
challenge of meeting housing needs while minimizing environmental impact. This
thesis explores attic conversions as a strategic form of adaptive reuse, offering a dual
potential: reducing carbon emissions and generating economic value. The study
compares attic conversions to new construction, based on semi-structured interviews
with industry professionals, a national resident survey and a literature review.
Findings show that attic conversions can lower carbon emissions by up to 71%
compared to new builds, primarily due to the reuse of existing structural elements.
However, the profitability of these projects is heavily influenced by factors such as
location, ownership models, volume and the experience of each project team.
Furthermore, the study identifies regulatory gaps and inconsistent measurement
standards as barriers to broader adoption of attic conversions, despite their strong
alignment with national sustainability goals.
The thesis concludes that attic conversions should be recognized not only as a
technical solution but as a powerful urban development strategy – one that requires
coordinated public policy, targeted support and cross-disciplinary collaboration to
unlock its full potential in the Swedish housing context. Additionally, attic
conversions represent a unique market niche due to their rare combination of modern
functionality and historic architectural charm
Utveckling och optimering av moderna AD-omvandlare
No full textAnalog-till-digital-omvandlare (ADC:er) är centrala i moderna elektroniska system,
men deras prestanda begränsas ofta av faktorer såsom energieffektivitet och noggrannhet.
Detta examensarbete undersöker de främsta prestandabegränsningarna
hos ADC:er och utmaningarna med olika ADC-arkitekturer. Metodiken innefattar
konstruktion och test av flera ADC-kretsar för att jämföra hur olika arkitekturer
presterar under varierande förhållanden. Arbetet har inneburit konstruktion och
testning av olika ADC-arkitekturer för att jämföra deras prestanda under varierande
förhållanden. Genom praktiska experiment och mätningar analyserades hur
effekterna av olika samplingsfrekvenser och variationer i designval påverkar systemets
totala prestanda. Studien visar att samplingsfrekvensen är en kritisk faktor
i ADC:ns prestanda och att möjligheter att inkorporera digitala tekniker för att
förbättra prestandan är således möjliga. Trots att en fördjupad analys med högkvalitativa
komponenter ej var möjlig inom tidsramen för arbetet så vissa aspekter
endast behandlades teoretiskt, har arbetet tydligt belyst styrkor och svagheter hos
olika ADC-arkitekturer. Vidare studier kan genomföras med dessa högkvalitativa
komponenter samt längre testperioder för att kunna dra mer djupgående slutsatser.
Arbetet bidrar till förståelsen för ADC:ers uppbyggnad och begränsningar samt ger
vägledning för framtida utveckling
Sustainable and novel user experience for the future of energy management
No full textSustainable and novel user experience for the future of energy managemen
Annotation-free Learning for Sensor Fusion in ADAS
No full textVehicle automation has the potential to significantly improve road safety. Achieving
comprehensive vehicle perception requires systems that optimally combine information
from multiple sensor modalities. Such systems leverage the strengths of each
modality while compensating for their weaknesses. By continuously encoding and
fusing information from cameras, LiDARs, RADARs and the motion of the egovehicle,
a dynamic representation of the surrounding environment can be created
and maintained.
A major challenge for these systems is the large amount of annotated data required
for training, as manual labelling creates a significant bottleneck for scalability. In
this study, a pre-training task for a multi-modal machine learning model was implemented
and evaluated. To circumvent labour-intensive labelling, self-supervision
was employed, with both the model input and the supervision signal involving
annotation-free data. The pre-training aimed to learn general features related to
sensor pose changes by predicting ego-vehicle pose changes using odometry data.
To assess pre-training performance, the features were then used as initial weights
for fine-tuning a perception model. The performance of the perception model using
baseline weights trained on annotated data was similar to that using weights trained
on annotation-free data, indicating that the proposed method is viable. However,
further testing is required to establish statistical significance. Future work could
explore implementing attention-based methods for feature matching between scene
representations to improve model performance
Synthesis and Characterization of Barium Titanate and Barium Indate-Zirconate Perovskite Oxyhydrides
No full textThe global imperative to reduce CO2 emissions has driven interest in catalytic conversion technologies, particularly CO2 hydrogenation, which transforms CO2 into valuable chemicals. This reaction often relies on metallic nanoparticles supported
on catalyst substrates, commonly metal oxides like Al2O3 or ZrO2. Perovskite oxides have emerged as promising alternatives due to their adjustable surface chemistry, thermal stability, and ability to host redox-active defect sites. Recent attention has turned to anion-adjusted perovskite materials, amongst them oxyhydrides, where oxygen anions are partially replaced by hydride ions. These modifications can enhance catalytic performance and introduce properties such as hydride ion conductivity and interesting electronic and magnetic properties. This project focused on the synthesis and structural analysis of reduced perovskite oxides of synthesised barium titanate (BaTiO3), nano-crystalline barium titanate and barium indate-zirconate (BaZr1−xInxO3− x2 ). For BaTiO3, synthesis routes mainly investigated reduction with CaH2 enclosed in stainless steel capsules, filled with high purity argon. For BaZr1−xInxO3− x2 , reduction by H2 gas annealing was investigated. Characterization heavily relied on powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA) measurements. Inelastic neutron scatterin (INS) was performed for a reduced 50% indium substituted BaZr0.5In0.5O2.75. The study primarily investigated how synthesis parameters such as molar ratio of CaH2, temperature, and heating time affect reduction extent, anion composition, phase formation, impurity formation and crystallinity. The CaH2 reduction of synthesized tetragonal BaTiO3 at 600◦C for 48 hours yields reduced products with a cubic phase, accompanied by a colour change from white to dark blue or black. An increased molar ratio of CaH2 leads to a greater degree of reduction. Rietveld refinements indicate formation of a single phase in these reduced samples. In contrast, samples of nano-BaTiO3 subjected to the same reduction conditions exhibit a lower degree of reduction and show more pronounced two-phase indications. Higher molar CaH2 ratios result in the formation of Ba2TiO4 impurities. These impurity phases can be reduced by decreasing the CaH2 ratio. For the nano-BaTiO3, a temperature decrease to 580◦ C doesn’t impact Ba2TiO4 amounts. Shortening the heating time to 24 hours leads to decreased amounts, at the expense of a lower reduction extent in the nano-BaTiO3 perovskite phase. Hydrogen annealing of BaZr1−xInxO3− x2 with 50% indium substitution at 800◦ C for 24 hours and 70% substitution at 650◦ C for 20 hours give reduced perovskite oxides of barium indate-zirconate. The extent of reduction is comparable between the two compositions. Inelastic neutron scattering (INS) measurements on the 50% BaZr1−xInxO3−x/2 sample indicate minimal hydride incorporation