Time Localization and Capacity of Faster-Than-Nyquist Signaling

In this paper, we consider communication over the bandwidth limited analog white Gaussian noise channel using non-orthogonal pulses. In particular, we consider non-orthogonal transmission by signaling samples at a rate higher than the Nyquist rate. Using the faster-than-Nyquist (FTN) framework, Mazo showed that one may transmit symbols carried by sinc pulses at a higher rate than that dictated by Nyquist without loosing bit error rate. However, as we will show in this paper, such pulses are not necessarily well localized in time. In fact, assuming that signals in the FTN framework are well localized in time, one can construct a signaling scheme that violates the Shannon capacity bound. We also show directly that FTN signals are in general not well localized in time. Therefore, the results of Mazo do not imply that one can transmit more data per time unit without degrading performance in terms of error probability. We also consider FTN signaling in the case of pulses that are different from the sinc pulses. We show that one can use a precoding scheme of low complexity to remove the inter-symbol interference. This leads to the possibility of increasing the number of transmitted samples per time unit and compensate for spectral inefficiency due to signaling at the Nyquist rate of the non sinc pulses. We demonstrate the power of the precoding scheme by simulations

Catalytic ortho- to parahydrogen conversion in liquid hydrogen

The kinetics of the catalytic conversion of ortho- to parahydrogen was studied for the two catalysts, IONEX® and OXISORB®. The study also involved the optimization of an experimental technique for the conversion of orthohydrogen in a static setup. The main focus of the optimization being directed towards the analytical setup, where the acquisition of information and interpretation of the data were two main points for optimization. The rate of conversion is an important factor regarding the choice of catalyst for the future ESS hydrogen loop. A parahydrogen concentration of 99.5% has been determined as the lowest concentration yield from the catalytic conversion process. Both catalyst showed a good performance for the conversion of ortho- to parahydrogen, where a concentration of 99.7 to 99.8% parahydrogen was obtained from the experiments. The kinetics for the catalyzed conversion of orthohydrogen using IONEX® and OXISORB® was determined to be based on first order exponential equations. The kinetics of IONEX® was described by a single first order exponential function. While the conversion of OXISORB® showed to be a function of two first order equations, which exhibits an independence as well as a codependence on one another. The kinetics of conversion for the catalyst showed that the IONEX® catalyst is more efficient in converting ortho-hydrogen into parahydrogen. This is shown from the specific rate and the space velocity of the catalyst, based on the conditions of the experiment and the ESS hydrogen loop respectively. Both catalysts appear to be suitable options for the future ESS hydrogen loop, where both catalysts possess the catalytic strength to compensate for the back conversion of parahydrogen during moderation of the emitted neutrons. The study shows that the IONEX® catalyst is the most efficient option but the final assessment would require a study of the long-term degenerative effects of the catalysts which could not be determined from the limited number of experiments carried out in this work.High parahydrogen content is an important factor for the ESS liquid hydrogen moderator to maximize the neutron brightness. Parahydrogen is obtained by catalytic conversion of orthohydrogen and this thesis work is dedicated to the kinetic study of the orthohydrogen conversion for two types of catalysts. This will provide useful information for the selection of the catalyst to be used by ESS

Downlink Spectral Efficiency of Cell-Free Massive MIMO with Full-Pilot Zero-Forcing

Cell-free Massive multiple-input multiple-output (MIMO) ensures ubiquitous communication at high spectral efficiency (SE) thanks to increased macro-diversity as compared cellular communications. However, system scalability and performance are limited by fronthauling traffic and interference. Unlike conventional precoding schemes that only suppress intra-cell interference, full-pilot zero-forcing (fpZF), introduced in [1], actively suppresses also inter-cell interference, without sharing channel state information (CSI) among the access points (APs). In this study, we derive a new closed-form expression for the downlink (DL) SE of a cell-free Massive MIMO system with multi-antenna APs and fpZF precoding, under imperfect CSI and pilot contamination. The analysis also includes max-min fairness DL power optimization. Numerical results show that fpZF significantly outperforms maximum ratio transmission scheme, without increasing the fronthauling overhead, as long as the system is sufficiently distributed.Comment: Paper published in 2018 IEEE Global Conference on Signal and Information Processing (GlobalSIP). {\copyright} 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other use

Аналіз витрат палива сільськогосподарської техніки

Abstract—An analysis of broadcasting in massive MIMO (multiple-input and multiple-output) systems with a limited coherence interval is presented. When broadcasting common information, such as control signals, the base station does not have channel state information to the terminals. We propose that the base station broadcasts this common information using a low dimensional orthogonal space-time block code (OSTBC). This code is mapped onto the large antenna array with the use of a dimension reducing matrix, effectively “shrinking” the channel. The terminal can estimate the effective channel and decode the information, even when the coherence interval is short compared to the number of base station antennas. Different OSTBCs are compared in terms of outage capacity in practical scenarios using estimated CSI. In particular, the trade-off between diversity and rate, when little or no time/frequency diversity is available, is investigated

Towards Learning Abstractions via Reinforcement Learning

In this paper we take the first steps in studying a new approach to synthesis of efficient communication schemes in multi-agent systems, trained via reinforcement learning. We combine symbolic methods with machine learning, in what is referred to as a neuro-symbolic system. The agents are not restricted to only use initial primitives: reinforcement learning is interleaved with steps to extend the current language with novel higher-level concepts, allowing generalisation and more informative communication via shorter messages. We demonstrate that this approach allow agents to converge more quickly on a small collaborative construction task.Comment: AIC 2022, 8th International Workshop on Artificial Intelligence and Cognitio

Local Partial Zero-Forcing Precoding for Cell-Free Massive MIMO

Cell-free Massive MIMO (multiple-input multiple-output) is a promising distributed network architecture for 5G-and-beyond systems. It guarantees ubiquitous coverage at high spectral efficiency (SE) by leveraging signal co-processing at multiple access points (APs), aggressive spatial user multiplexing and extraordinary macro-diversity gain. In this study, we propose two distributed precoding schemes, referred to as \textit{local partial zero-forcing} (PZF) and \textit{local protective partial zero-forcing} (PPZF), that further improve the spectral efficiency by providing an adaptable trade-off between interference cancelation and boosting of the desired signal, with no additional front-hauling overhead, and implementable by APs with very few antennas. We derive closed-form expressions for the achievable SE under the assumption of independent Rayleigh fading channel, channel estimation error and pilot contamination. PZF and PPZF can substantially outperform maximum ratio transmission and zero-forcing, and their performance is comparable to that achieved by regularized zero-forcing (RZF), which is a benchmark in the downlink. Importantly, these closed-form expressions can be employed to devise optimal (long-term) power control strategies that are also suitable for RZF, whose closed-form expression for the SE is not available.Comment: This paper was accepted for publication in IEEE Transactions on Wireless Communications on March 31, 2020. {\copyright} 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other use

Vilka aspekter finns det att beakta kring gödselseparering och dess transporter?

I dagens jordbruk finns det en ojämn fördelning utav näringsämnena från den animaliska gödseln. De flesta djurgårdarna är belägna i skogs och mellanbygd där det oftast inte finns tillräckligt med spridningsareal. Ute på slättmarkerna finns mer areal att tillgå men djurtätheten här blir ofta allt glesare och tillgången på stallgödsel minskar. Idag har oftast rena växtodlingsgårdar en negativ fosforbalans på ca – 4 kg p/ha (Wikström, 2020). Att transportera gödsel kostar pengar och kräver oftast att stora volymer transporteras. Tanken är att med modern teknik kunna öka koncentrationen av växtnäringsämnen i gödseln genom att man separerar ut en flytande och en fast fraktion som erhåller olika halter av näringsämnena. Då skulle det bli mer intressant att transportera den separerade gödseln längre sträckor efter som det skulle krävas färre transporter för att uppnå samma fosforgiva. Arbetet har utvärderat om det är mer lönsamt att flytta den separerade gödseln för fosforns skull i en mer koncentrerad vara för att få upp fosforvärden och mull på gårdar som inte annars har tillgång på separerad gödsel samt även undersökt påverkan som transporterna har för miljön. Sammanställningen av all data har bearbetats i ett Excel dokument. Det fanns en tydligt skillnaden mellan separerad gödsel och flytgödsel, främst för miljön men även för ekonomiska aspekter. Vi har sedan valt att visa resultatet i rapporten med linjediagram för att enkelt följa upp skillnaden när det blir lönsamt med att separera gödseln, där har vi tagit hänsyn till en rad olika faktorer, ex kostnad för separering, transport och spridningskostnad och växtnäringsinnehållet mm. Utifrån arbetet har följande slutsatser dragits: • Den fasta fraktionen från separerad svinflytgödsel är lönsamt att transportera från 18 km och uppåt. Den fasta fraktionen från separerad nötflytgödsel är först lönsamt att transportera när sträckan överstiger 45 km. Detta jämfört med att transportera flytgödsel för båda djurslagen. • På gårdsnivå är skruvpress det vanligaste. Det finns mer avancerade och effektivare tekniker men de blir oftast för dyra och komplexa eftersom de andra teknikerna har ler moment och kräver emellanåt kemikaliska insatser. Ekonomiska fördelar finns för att transportera separerad gödsel istället för flytgödsel. Miljömässiga fördelar finns i större utsträckning än ekonomiska fördelar.In today's agriculture, there is an uneven distribution of nutrients from animal manure. Most animal farms are located in forests and intermediate areas where there is usually not enough spreading area. On the plains there is more area available for spreading, however, the number of animals here is often becoming increasingly low and the availability of manure is diminishing. Today, pure crop production farms usually have a negative phosphorus balance of about - 4 kg P / ha (Wikström, 2020). Transporting manure costs money and usually requires large volumes to be transported. The idea is to use modern technology to increase the concentration of nutrients in the manure by separating a liquid and a fiber fraction which obtain different levels of the nutrients. Then it would be more profitable to transport the fiber fraktion of the manure longer distances as less manure has to be transported to achieve the same phosphorus yield. The work will evaluate whether it is more profitable to move the fiber fraction of the manure. For the sake of phosphorus in a more concentrated product to obtain higher phosphorus values and organic matter content on farmland that do not otherwise have access to manure and will also touch on the impact that the transport has on CO2 emission. There was a clear difference between separated manure and floating manure in terms of. We have then chosen to show the result in the line diagram report to easily follow up the difference when it becomes profitable to separate the manure. The following conclusions have been drawn from the work: • The fiberfraction of separated pig manure is profitable to transport 18 km or longer. The fiberfraktion of separated cattle manure is only profitable to transport when the distance exceeds 45 km. This compared with transporting slurry from both species. • At farm level, screw press is the most common. There are more advanced and more efficient techniques, but they are usually too expensive and complex and often require chemical action. • Economic benefits exist for transporting separated manure instead of floating manure. Environmental benefits were greater than economic benefits as there is a more significant difference, when environmental benefits become direct while the economic ones become more profitable at a longer distance

Kön, Diagnos och Mognad - en kvalitativ innehållsanalys av information om transsexualism på hemsidor

This study aims to examine how the concepts of gender, diagnose, maturation and transsexualism are described and socially constructed on websites. To understand how the concepts we prepared to interpret nine sites using Berger and Luckmann's social constructivist perspective, and by Foucault´s theory about power. The theories focus on that we are living within a society which perpetuates normative gender roles. The different owners of the websites presented concepts differ depending on the purpose they had with their information. Summary we saw during our work how complex all the concepts were and how difficult it was to find a unified description of the concepts. Although we live in a society well developed we did find during our work how the gender roles is still solid and it seems like we live in a society hard to understand and accept the grey area between the constructed gender roles man and woman. Our results shows that through the power of language and how we use it we keep the gender roles alive and maintains the society´s way of looking at gender as a specific role

Evolutionary psychology in the Ekonomikum Park and the Observatory Park in Uppsala : an evolutionary perspective as a basis for landscape analysis

Landskapsarkitektur har en roll i många problematiska situationer där olika intressen kan hamna i konflikt med den mänskliga upplevelsen av en plats eller ett område. Evolutionspsykologi söker förklaringar på den mänskliga naturen genom att undersöka vilken funktion beteenden haft evolutionärt. Flera teorier undersöker människans relation till landskapet utifrån detta perspektiv. Dessa teorier presenterar flera slutsatser om vilka egenskaper i landskapet som människor generellt dras till. Den här uppsatsens syfte är att undersöka hur evolutionspsykologiska teorier kan tillämpas inom landskapsarkitektur. Detta sker genom att en litteraturstudie inom området ligger till grund för utformningen av ett analysunderlag. Utifrån analysunderlaget görs en landskapsanalys av ett sammanhängande parkområde bestående av Ekonomikum- och Observatorieparkerna i Uppsala. Förklaringar till hur och varför man uppfattar parkerna som man gör ges ur ett evolutionspsykologiskt perspektiv. Teorierna appliceras på bägge parkerna och detta exemplifieras i en illustrerad analys i vilken teorierna är uppdelade och illustrerade på bearbetade flygfoton. Sammanfattningsvis resulterar landskapsanalysen i diskussionen att evolutionspsykologi kan erbjuda ett kompletterande perspektiv och synliggöra vissa viktiga aspekter för en landskapsarkitekt. Genom att försöka se på en plats genom ett evolutionspsykologiskt perspektiv går det att hitta förklaringar till varför vi uppfattar innehållet som vi gör. Dessa förklaringar bygger på våra preferenser som är medfödda, vilket medför att uppfattningarna av landskap blir relativt likartade för alla människor oavsett bakgrund. Att som landskapsarkitekt använda sig av ett evolutionspsykologiskt perspektiv kan vara värdefullt när attraktiva miljöer ska skapas.Landscape architecture has a role in many problematic situations where different interests can end in conflict with the human experience of a place or an area. Evolutionary psychology seeks explanations of human nature by investigating what function behaviors had in an evolutionary context. Several theories examine the human relation to the surrounding landscape from this perspective. These theories present characteristics of the landscape that humans are generally attracted to. The purpose of this Bachelor’s thesis is to investigate how evolutionary psychological theories could be applied in landscape architecture. This is done by letting literature studies in evolutionary psychology be the footing for the formulation of an analysis basis. After that, the analysis basis is applied on a cohesive park area consisting of Ekonomikumparken and Observatorieparken in Uppsala. Explanations of how and why you perceive the parks in the way you do are given from an evolutionary psychological perspective. The theories are applied in both parks and this is exemplified in an illustrated analysis in which the theories are divided and illustrated on aerial photos. In summary, the conclusion of the landscape analysis is that evolutionary psychology could offer a complementary perspective and highlight certain important aspects for a landscape architect. By trying to look at a place through an evolutionary psychological perspective, we can find explanations of why we perceive the content as we do. These explanations are based on our innate preferences, whereby these perceptions of landscapes become relatively similar to all people regardless of background. Using an evolutionary psychological perspective could be valuable for landscape architects when creating attractive places