Valuation and Optimization of Credit Risk using a Portfolio Model

In this paper I study a model for credit risk in a portfolio of sovereign bonds, based on (van der Hoorn, 2009). The model is based on historical credit rating changes and the joint distribution of the losses for dier- ent bonds is modeled with an assumption of an underlying multivariate Gaussian variable. Dierent risk measures for the portfolio are calculated using Monte Carlo simulations and the performance is improved by the use of importance sampling. I investigate dierent methods on how to improve the model and the estimation of the parameters of the model. I also develop methods to valuate the certainty of the risk measures based on a statistical view on the input data, which give clear indications that the small size of input data gives low accuracy for the risk measures. An attempt to write an algorithm to nd the optimal portfolio with respect to the risk measures is also performed and the results are discussed

RFID Antennas – Possibilities and Limitations

Non

Temporal Graph Neural Networks for Irregular Data

This paper proposes a temporal graph neural network model for forecasting of graph-structured irregularly observed time series. Our TGNN4I model is designed to handle both irregular time steps and partial observations of the graph. This is achieved by introducing a time-continuous latent state in each node, following a linear Ordinary Differential Equation (ODE) defined by the output of a Gated Recurrent Unit (GRU). The ODE has an explicit solution as a combination of exponential decay and periodic dynamics. Observations in the graph neighborhood are taken into account by integrating graph neural network layers in both the GRU state update and predictive model. The time-continuous dynamics additionally enable the model to make predictions at arbitrary time steps. We propose a loss function that leverages this and allows for training the model for forecasting over different time horizons. Experiments on simulated data and real-world data from traffic and climate modeling validate the usefulness of both the graph structure and time-continuous dynamics in settings with irregular observations.Comment: 17 pages, 4 figures. Accepted to AISTATS 2023. Code available at https://github.com/joeloskarsson/tgnn4

Burial grounds of the future : a historical review, issues of today and visions of the expression of future burial grounds

The purpose of this article is partly to find out how the burial grounds are used today and the needs of its visitors, but also to develop the character and expression of future burial grounds. My suggestions focus on burial grounds without religious attributes; something that, according to the burial law (Begravningslagen, 1990:1144), the manager of the burial ground is ordered to obey. In my design I aim to fulfill any requests regarding the place of burial that have been raised during my study. I have chosen the history of burial grounds as my starting point and will subsequently discuss their significance in today's society. I describe what distinguishes the burial ground throughout history from medieval times and onwards. Tradition and religion are closely linked regarding burial rituals. As the Swedish churchyard has a long Christian tradition it has at times felt necessary to introduce certain Christian aspects. I have also briefly explored how religion can express itself in today's secularized society. One important aspect I have noted is how the burial place can be used by the grieving and those in crisis and how it's been used as a place fore memorial. Literature documenting the importance of nature's healing properties and their effect on a person's sacred experiences is therefore an important part of this article. The article is founded on literature studies, interviews and study visits to burial grounds. With this knowledge base as my source of inspiration I have formed three burial grounds. Through my studies I have seen two clear aspects in the development of burial ground expressions; monumental memorials with strong architectural influences and the nature-like burial ground, which is created by enhancing nature's prerequisites to develop a sacred place. Often makes those to aspects used together un strongly sacred place. By the end of this article I will have presented three suggestions for the burial ground of the future. In the first proposition I have given form to an expansion of a pre-existing churchyard, using real prerequisites. The proposition is a traditional design with modern functions. The later suggestions are nonplace- specific concept sketches created from imagined environments; Trösteriket - an indoor burial place and Omfamning - monument by water.Mitt syfte med denna uppsats är att dels ta reda på hur begravningsplatsen används idag och vilka behov dess besökare har men också att utveckla idéer för framtida begravningsplatsers gestaltningsuttryck. Mina förslag fokuserar på begravningsplatsen utan religiösa attribut, något som huvudmannen för begravningsplatsen enligt begravningslagen (Begravningslagen, 1990:1144) är ålagd att följa. I min utformning försöker jag uppfylla önskemål angående begravningsplatsen som framkommit i mina studier. Jag har valt att ta avstamp i begravningsplatsens historia, för att sedan behandla dess betydelse i dagens samhälle. Jag beskriver vad som utmärkt begravningsplatsen under historien från medeltiden och framåt. Gällande begravningsritualer är tradition och religion nära sammankopplat. Eftersom den svenska kyrkogården har en lång kristen tradition har det känts relevant att ta upp vissa kristna aspekter. Jag har också berört hur religiositeten kan yttra sig i dagens sekulariserade samhälle. En viktig aspekt som jag tagit fasta på är hur begravningsplatsen kan brukas av sörjande människor i kris samt hur den brukas av människor som minnesplats. Därför utgör litteratur om naturens läkande förmåga samt om naturens betydelse för människans sakrala upplevelser en viktig del av uppsatsen. Uppsatsen bygger på litteraturstudier, intervjuer och studiebesök på begravningsplatser. Med den kunskapsbasen som inspirationskälla har jag gestaltat tre begravningsplatser. Jag har genom mina studier sett två tydliga gestaltningsaspekter i utvecklingen av begravningsplatsens uttryck; monumentala minnesmärken med starka arkitektoniska grepp och den naturlika begravningsplatsen som gestaltas genom att förstärka naturens grundförutsättningar för att skapa en sakral plats. Ofta stärks den sakrala stämningen på platsen genom att dessa två sammanfogas. I slutet av uppsatsen redovisas mina tre gestaltningsförslag; tre möjliga gestaltningsuttryck av framtidens begravningsplatser. I det första förslaget har jag gestaltat en utvidgning av en befintlig kyrkogård, utifrån verkliga förutsättningar. Förslaget är en traditionell utformning med nya funktioner. De senare förslagen är icke platsspecifika konceptskisser skapade utifrån tänkta miljöer; Trösteriket - en begravningsplats inomhus och Omfamning � monument vid vatten

Scanning the horizon: towards transparent and reproducible neuroimaging research

Functional neuroimaging techniques have transformed our ability to probe the neurobiological basis of behaviour and are increasingly being applied by the wider neuroscience community. However, concerns have recently been raised that the conclusions that are drawn from some human neuroimaging studies are either spurious or not generalizable. Problems such as low statistical power, flexibility in data analysis, software errors and a lack of direct replication apply to many fields, but perhaps particularly to functional MRI. Here, we discuss these problems, outline current and suggested best practices, and describe how we think the field should evolve to produce the most meaningful and reliable answers to neuroscientific questions