409 research outputs found

    Information about chemicals in articles

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    This study assesses the problems of loss of information about chemicals throughout the global product chain of toys, concentrated on import to the European Union. The aim of the study was to use qualitative interviews as well as available literature to describe the present situation regarding information about chemicals in the toy industry, to investigate whether information is lost and in that case where and why. According to the results, information about chemicals in toys is primarily lost in two different stages: high up in the supply chain due to patent issues and production secrets of the chemical supplier, and at the stage of import because the information was not requested here or in earlier tier of the supply chain. This study also found out that information about chemicals in toys will be improved in the EU within the near future, due to ongoing legislative revisions. The entry into force of the recent EU chemical regulation REACH and the revision of the EU Toy Safety Directive will bring stricter requirements on chemicals in nonelectrical toys that are not chemical products, and the Toy Safety Directive will also bring clearer provisions on responsibilities for information transfer as well as improved provisions for surveillance. Further on, this study investigated suitable ways of transferring information about chemicals in toys. The findings on this issues suggest that even though it is not possible to require companies to show exactly which substances are present in their products, there seems to be benefits for the companies themselves about having as much information as possible. Most importantly, importing companies need to be transparent with what their products contain, to rebuild consumers' confidence in toys

    FX BASKET OPTIONS - Approximation and Smile Prices

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    Pricing a Basket option for Foreign Exchange (FX) both with Monte Carlo (MC) techniques and built on different approximation techniques matching the moments of the Basket option. The thesis is built on the assumption that each underlying FX spot can be represented by a geometric Brownian motion (GBM) and thus have log normally distributed FX returns. The values derived from MC and approximation are thereafter priced in a such a way that the FX smile effect is taken into account and thus creating consistent prices. The smile effect is incorporated in MC by assuming that the risk neutral probability and the Local Volatility can be derived from market data, according to Dupire (1994). The approximations are corrected by creating a replicated portfolio in such a way that this replicated portfolio captures the FX smile effect

    Food Webs, Models and Species Extinctions in a Stochastic Environment

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    In light of the current global mass extinction of species, ecologists are facing great challenges. In order to reverse the path towards additional extinctions early warning systems to guide management actions need to be developed. However, considering the countless species to monitor and the complexity of interactions affecting species abundances in ecological communities, this is not an easy task. Before this goal can be reached our understanding of how community structure and species interactions interact and affect the risk of extinction of single species needs to be increased. Thus the primary aim of the present thesis is to study this interaction and contribute to a theoretical basis for the identification of extinction prone species. In paper II it is concluded that spectral analysis of population time series may function as a tool to predict extinctions at an early stage. More specifically, I show that extinction risk of producer species in food webs under influence of uncorrelated environmental stochasticity increases with intensified red-shift of population time series. However, this relationship is strictly context-dependent, which means that a producer with red dynamics might survive in one type of food web, but the same producer species with a similar magnitude of spectral redness can go extinct in another food web where the interactions with other species are arranged in a different manner. Then I turn to look at which species might be more prone to become endangered or to go extinct in food webs experiencing various types of uncorrelated environmental stochasticity. In paper I I show that producer species are more likely to reach endangered population levels (according to The World Conservation Union, IUCN, criterion), whereas paper III demonstrates that consumer species more frequently go extinct. This seemingly contradiction may be explained by characteristics inherent to many producer species (e.g. high growth rate, short generation time) that enable them to recover from low population levels and thus escape extinction. Furthermore, in both the second and the third paper I show that the structure of food webs as well as the presence, position and direction of a strong interaction between two species in a food web play significant roles in the likelihood of a species reaching endangered population levels or going extinct. In paper IV I show that small and condensed food webs are likely to express fundamentally different dynamics compared to large and well-resolved versions of the same natural food webs. Starting from a well-resolved version of a real food web, local dynamics of the ecological system change in a non-linear manner, during gradual lumping of the functionally most similar species into aggregated species (or trophospecies), Here it is also suggested that functional redundancy exists in natural food webs. This may imply support for the ?insurance hypothesis? since sequential extinction of one of the species in the functionally most similar pair of species initially did not generate any significant changes in local dynamics of the system. To sum up, in this thesis I present a prototype of a predictive tool to discover species at risk of going extinct. I also present directions to which type of species to look for and what type of structures and interactions to pay attention to when searching for presumptive victims of extinction in ecological systems. However, the features of the ecological models I have used for my research are in many cases incomplete. For example, my food webs contain relatively few species without competitive interactions subjected to only uncorrelated environmental variability. Further research will have to test the generality of the results and the robustness of the conclusions drawn from them

    Essays in Quantitative Finance

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    This thesis contributes to the quantitative finance literature and consists of four research papers.Paper 1. This paper constructs a hybrid commodity interest rate market model with a stochastic local volatility function that allows the model to simultaneously fit the implied volatility of commodity and interest rate options. Because liquid market prices are only available for options on commodity futures (not forwards), a convexity correction formula is derived to account for the difference between forward and futures prices. A procedure for efficiently calibrating the model to interest rate and commodity volatility smiles is constructed. Finally, the model is fitted to an exogenously given cross-correlation structure between forward interest rates and commodity prices. When calibrating to options on forwards (rather than futures), the fitting of cross-correlation preserves the (separate) calibration in the two markets (interest rate and commodity options), whereas in the case of futures, a (rapidly converging) iterative fitting procedure is presented. The cross-correlation fitting is reduced to finding an optimal rotation of volatility vectors, which is shown to be an appropriately modified version of the “orthonormal Procrustes” problem. The calibration approach is demonstrated on market data for oil futures.Paper 2. This paper describes an efficient American Monte Carlo approach for pricing Bermudan swaptions in the LIBOR market model using the Stochastic Grid Bundling Method (SGBM) which is a regression-based Monte Carlo method in which the continuation value is projected onto a space in which the distribution is known. We demonstrate an algorithm to obtain accurate and tight lower–upper bound values without the need for the nested Monte Carlo simulations that are generally required for regression-based methods.Paper 3. The credit valuation adjustment (CVA) for over-the-counter derivatives are computed using the portfolio’s exposure over its lifetime. Usually, future exposure is approximated by Monte Carlo simulations. For derivatives that lack an analytical approximation for their mark-to-market (MtM) value, such as Bermudan swaptions, the standard practice is to use the regression functions from the least squares Monte Carlo method to approximate their simulated MtMs. However, such approximations have significant bias and noise, resulting in an inaccurate CVA charge. This paper extend the SGBM to efficiently compute expected exposure, potential future exposure, and CVA for Bermudan swaptions. A novel contribution of the paper is that it demonstrates how different measures, such as spot and terminal measures, can simultaneously be employed in the SGBM framework to significantly reduce the variance and bias.Paper 4. This paper presents an algorithm for simulation of options on LĂ©vy driven assets. The simulation is performed on the inverse transition matrix of a discretised partial differential equation. We demonstrate how one can obtain accurate option prices and deltas on the variance gamma (VG) and CGMY model through finite element-based Monte Carlo simulations

    The Heston Model - Stochastic Volatility and Approximation

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    The crude assumption on log normal stock returns and constant volatility in the Black-Scholes model is a big constraint which constructs smile and skew inconsistent prices. The Heston model and its suggested approximation built on stochastic volatility are introduced and faced against the Black-Scholes model in hope of producing option prices where the smile and skew are taken into account.. As one will observe later on is that numerical calculation and approximation of the Heston model will provide us with more accurate calculations

    Application of the Vagueness Doctrine to Statutes Terminating Parental Rights

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    The norm-optimal iterative learning control (ilc) algorithm for linear systems is extended to an estimation-based norm-optimal ilc  algorithm where the controlled variables are not directly available as measurements. A separation lemma is presented, stating that if a stationary Kalman filter is used for linear time-invariant systems then the ilc  design is independent of the dynamics in the Kalman filter. Furthermore, the objective function in the optimisation problem is modified to incorporate the full probability density function of the error. Utilising the Kullback–Leibler divergence leads to an automatic and intuitive way of tuning the ilc  algorithm. Finally, the concept is extended to non-linear state space models using linearisation techniques, where it is assumed that the full state vector is estimated and used in the ilc  algorithm. Stability and convergence properties for the proposed scheme are also derived.Vinnova Excellence Center LINK-SICExcellence Center at Linköping-Lund in Information Technology, ELLIITSSF project Collaborative Localizatio

    Indikatorer för industriell symbios – Utformning av riktlinjer och en modell för mĂ€tning och kommunikation av industriell symbios i Sverige

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    I en vĂ€rld dĂ€r klimathot och resursbrist har vĂ€xt fram till ett allt större problem pĂ„ vĂ€rldsledarnas agenda har vikten av hĂ„llbar utveckling identifierats som en nyckelfrĂ„ga i vĂ€gen mot en bĂ€ttre framtid. En metod för detta Ă€r industriell symbios, som innebĂ€r att olika företag och organisationer gemensamt utnyttjar energi, nyttigheter, material eller service, för att pĂ„ ett innovativt sĂ€tt skapa mervĂ€rden samt minska kostnader och miljöpĂ„verkan. I detta arbete har en undersökning gjorts kring hur mĂ€tning och kommunikation av industriell symbios sker i dagslĂ€get, samt vilka aktörer som Ă€r inblandade och vad som driver dessa. UtifrĂ„n detta definieras riktlinjer och en modell för hur mĂ€tning och kommunikation bör sker framöver. Undersökningen bygger huvudsakligen pĂ„ projektet ”Industriell Symbios – Lokal samverkan för hĂ„llbart nĂ€ringsliv” som pĂ„gĂ„r i VĂ€stra Götalandsregionen, men det ger ocksĂ„ en övergripande beskrivning av pĂ„gĂ„ende projekt inom industriell symbios i hela Sverige. En litteraturstudie genomfördes i syfte att fĂ„ en övergripande bild av industriell symbios, identifiera vilka system och metoder för mĂ€tning som tidigare har föreslagits, samt sammanstĂ€lla teori kring hur mĂ€tsystem och indikatorer bör utformas i allmĂ€nhet. Detta kompletterades med intervjuer med representanter ur de huvudsakliga intressentkategorierna som definierats. De huvudsakliga aktörer som verkar inom industriell symbios Ă€r antingen facilitatörer, samhĂ€lle, nĂ€ringsliv, finansiĂ€rer eller akademi. Alla ser vikten av ekonomisk rimlighet för att de föreslagna lösningarna ska vara genomförbara och hĂ„llbara i lĂ€ngden. Utöver detta finns det stora skillnader i hur de ser pĂ„ industriell symbios och hur de vĂ€rderar och prioriterar ekonomiska, sociala och miljömĂ€ssiga fördelar. Baserat pĂ„ dessa upptĂ€ckter definieras kraven pĂ„ ett system för mĂ€tning och kommunikation som att det framförallt mĂ„ste vara enkelt och flexibelt nog för att kunna kommuniceras gentemot alla former av intressenter. UtifrĂ„n detta presenteras en modell som kan visa pĂ„ nulĂ€ge och potential för industriell symbios inom flera olika omrĂ„den. Denna modell bestĂ„r i en visuell uppdelning i 3 olika nivĂ„er av specifika resursflöden baserat pĂ„ om de anvĂ€nds, om det finns potential för anvĂ€ndning, eller om det inte gĂ„r att göra nĂ„got med dem i dagslĂ€get. AnvĂ€ndningen delas ocksĂ„ upp i energiĂ„tervinning, materialĂ„tervinning, respektive Ă„terbruk för att gynna högvĂ€rdig anvĂ€ndning av resurser.In a world where climate change and resource scarcity have grown to some of the main issues on the world leaders’ agenda the importance of sustainable development has been identified as a key challenge in the path towards a better future. One method for this is industrial symbiosis, where different entities collaborate over energy, utilities, materials or services to create value and lower cost and environmental impact. This report covers how measuring and communication of industrial symbiosis works today, as well as which stakeholders are part of it and why. Based on this guidelines and a model for measuring and communication of industrial symbiosis was developed. The report is mainly based on the project “Industrial symbiosis – Local collaboration for sustainable business” in the region of VĂ€stra Götaland, but it also gives an overview of current projects within industrial symbiosis in all of Sweden. A literature review was conducted to get an overview of industrial symbiosis, to identify systems and methods for measuring that have been proposed earlier, and to compile theory regarding performance measurement and key performance indicators. This was complemented with interviews with representatives from the main categories of stakeholders. The main stakeholders within industrial symbiosis are facilitators, communities, business, sponsors and academy. All of these understand the importance of economic feasibility for the proposed synergies to be sustainable in the long run. Apart from this their interest, competence and agendas with industrial symbiosis differ with regards to things as their view on social, business and environmental benefits. Based on these findings requirements and guidelines for a system for measurement and communication of industrial symbiosis were defined as being simple and flexible enough to be useful towards all kinds of stakeholders. From these guidelines a model was developed for measuring and showing the current state and potential of industrial symbiosis within different areas. This is visualized using three main levels based on if a specific resource is used, if it has potential to be used, or if it unusable with current technology. This usage can further be broken down into energy recycling, material recycling, or reusage in order to promote a higher level utilization of resources.I en vĂ€rld dĂ€r klimathot och resursbrist har vĂ€xt fram till ett allt större problem pĂ„ vĂ€rldsledarnas agenda har vikten av hĂ„llbar utveckling identifierats som en nyckelfrĂ„ga i vĂ€gen mot en bĂ€ttre framtid. Industriell symbios Ă€r ett verktyg för att frĂ€mja utvecklingen mot ett mer cirkulĂ€rt affĂ€rstĂ€nkande, men för att lyckas med detta krĂ€vs nya metoder för mĂ€tning och kommunikation av detta koncept. En undersökning har dĂ€rför gjorts för att definiera riktlinjer och krav för dessa indikatorer, och utifrĂ„n detta har en modell för resursutnyttjande utvecklats. Under de senaste decennierna har hĂ„llbarhet, klimathotet och utarmningen av jordens resurser utvecklats till nĂ„gra av de viktigaste punkterna pĂ„ vĂ€rldsledarnas agenda, och dessa frĂ„gor Ă€r idag mer aktuella Ă€n nĂ„gonsin. Med en vĂ€rldsbefolkning som förutspĂ„s ha ökat frĂ„n 7,5 till 9 miljarder fram till Ă„r 2050, en vĂ€xande medelklass, och ökad resursanvĂ€ndning krĂ€vs det drastiska förĂ€ndringar för att vĂ€nda denna trend och skapa en lĂ„ngsiktigt hĂ„llbar vĂ€rld. Det krĂ€vs ett nytt tankesĂ€tt, dĂ€r dagens linjĂ€ra syn pĂ„ resursflöden ersĂ€tts av ett cirkulĂ€rt perspektiv dĂ€r alla resurser utnyttjas till sin fulla potential. En metod för att frĂ€mja övergĂ„ngen frĂ„n den linjĂ€ra till den cirkulĂ€ra ekonomin Ă€r industriell symbios. Detta Ă€r ett koncept som innebĂ€r att olika företag och organisationer gemensamt utnyttjar energi, nyttigheter, material eller service, för att pĂ„ ett innovativt sĂ€tt skapa mervĂ€rden samt minska kostnader och miljöpĂ„verkan. Detta kan exempelvis handla om att i fiskrens och spillvĂ€rme se potentialen till att starta en laxodling, att gemensamt anvĂ€nda lager och fordon, eller att utvinna nödvĂ€ndiga nĂ€ringsĂ€mnen för jordbruk ur grannens avfallsvatten. Det alla synergier har gemensamt Ă€r dock att de alla bygger pĂ„ att det finns nĂ„gon form av resurs som i dagslĂ€get inte utnyttjas till fullo. Den stora utmaningen ligger i att det Ă€r mĂ„nga olika intressenter inblandade i form av allt frĂ„n enskilda företag till statliga myndigheter. Alla parter har dĂ€rför olika krav och preferenser kring vilka resultat som Ă€r relevanta just för dem. Kommunpolitiker vill exempelvis gĂ€rna kunna förklara för invĂ„narna hur hens satsningar pĂ„ industriell symbios har skapat mĂ„nga nya jobb, medan en företags-VD Ă„ andra sidan endast vill veta hur snabbt de skulle betala av sig. En modell för mĂ€tning och kommunikation bör dĂ€rför frĂ€mst vara: ‱ Kommunicerbar: För att utveckla industriell symbios Ă€r det viktigaste att övertyga och motivera de individer som i grunden utgör dessa nĂ€tverk. FörutsĂ€ttningar, potential och resultat mĂ„ste dĂ€rför kunna kommuniceras pĂ„ ett sĂ€tt som alla kan förstĂ„ och stĂ€lla sig bakom, oavsett bakgrund och mĂ„l. ‱ Flexibel: FramgĂ„ngsrik industriell symbios skapas nĂ€r det baseras pĂ„ lokala förutsĂ€ttningar och möjligheter. Ett mĂ€tsystem mĂ„ste dĂ€rför vara flexibelt nog för att kunna hantera alla former av synergier, oavsett om det handlar om lastbilar, personal eller avfallsvatten. De indikatorer som anvĂ€nds i ett sĂ„dant system bör dĂ€rför vara: ‱ Enkla: De mĂ„ste vara enkla att förstĂ„, visualisera och kommunicera ‱ Procentuella: FörhĂ„llanden Ă€r lĂ€ttare att förstĂ„ Ă€n absoluta tal. Om man istĂ€llet för att sĂ€ga att ett företag endast utnyttjar 2000 liter av sitt avfallsvatten kan sĂ€ga att de endast utnyttjar 5 % Ă€r det lĂ€ttare att förstĂ„ den förbĂ€ttringspotential som finns. ‱ ÖversĂ€ttningsbara: Det Ă€r svĂ„rt att veta hur mycket 130 000 ton koldioxid motsvarar, men om man istĂ€llet sĂ€ger att det motsvarar utslĂ€ppen frĂ„n alla bilar i Helsingborg och Ängelholm under 9 mĂ„nader sĂ„ ser folk lĂ€ttare vinningen i denna besparing. UtifrĂ„n dessa riktlinjer har en modell utvecklats. Den bygger i grunden pĂ„ att alla former av resurser antingen redan utnyttjas, har potential för att utnyttjas, eller Ă€r omöjliga att göra nĂ„got med i dagslĂ€get. För de utnyttjade resurserna skiljer man Ă€ven pĂ„ hur de anvĂ€nds, dĂ€r det oftast Ă€r bĂ€ttre att t.ex. Ă„teranvĂ€nda Ă€n att brĂ€nna en produkt. Denna modell kan sedan anvĂ€ndas som ett underlag för diskussioner och möjligheter inom olika företag och nĂ€tverk, som kommunikationsverktyg gentemot finansiĂ€rer och samhĂ€llsaktörer, eller för att kunna lĂ€ra av andra nĂ€tverk och deras resursanvĂ€ndning. CirkulĂ€r ekonomi Ă€r hĂ€r för att stanna, och oavsett om det sker genom industriell symbios, delningsekonomin eller försĂ€ljning av produkter som en service sĂ„ handlar det i slutĂ€ndan om att enskilda individer mĂ„ste vĂ€lja att anvĂ€nda detta. Om de dĂ„ gör det för egen ekonomisk vinning, för sina medmĂ€nniskor och lokalsamhĂ€llet, eller för att rĂ€dda vĂ„r jord, spelar i slutĂ€ndan ingen roll. Det viktigaste Ă€r att det sker innan det Ă€r för sent! En utförligare beskrivning av undersökningen och den föreslagna modellen kan lĂ€sas i examensarbetet ”Indikatorer för industriell symbios – Utformning av riktlinjer och en modell för mĂ€tning och kommunikation av industriell symbios i Sverige”

    Structure of glassy lithium sulfate films sputtered in nitrogen (LISON): Insight from Raman spectroscopy and ab initio calculations

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    Raman spectra of thin solid electrolyte films obtained by sputtering a lithium sulfate target in nitrogen plasma are measured and compared to ab initio electronic structure calculations for clusters composed of 28 atoms. Agreement between measured and calculated spectra is obtained when oxygen atoms are replaced by nitrogen atoms and when the nitrogen atoms form bonds with each other. This suggests that the incorporation of nitrogen during the sputtering process leads to structures in the film, which prevent crystallization of these thin film salt glasses.Comment: 5 pages, 4 figure

    Counterparty credit exposures for interest rate derivatives using the Stochastic Grid Bundling Method

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    The regulatory credit value adjustment (CVA) for an outstanding over-the-counter (OTC) derivative portfolio is computed based on the portfolio exposure over its lifetime. Usually, the future portfolio exposure is approximated using the Monte Carlo simulation, as the portfolio value can be driven by several market risk-factors. For derivatives, such as Bermudan swaptions, that do not have an analytical approximation for their Mark-to-Market (MtM) value, the standard market practice is to use the regression functions from the least squares Monte Carlo method to approximate their MtM along simulated scenarios. However, such approximations have significant bias and noise, resulting in inaccurate CVA charge. In this paper, we extend the Stochastic Grid Bundling Method (SGBM) for the one-factor Gaussian short rate model, to efficiently and accurately compute Expected Exposure, Potential Future exposure and CVA for Bermudan swaptions. A novel contribution of the paper is that it demonstrates how different measures, for instance spot and terminal measure, can simultaneously be employed in the SGBM framework, to significantly reduce the variance and bias of the solution
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