559 research outputs found

    Visual design and variation of mediums in e-learning resources

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    Master's thesis Multimedia and Educational Technology MM500 - University of Agder 2017Konfidensiell til / confidential until 01-07-202

    Near-Optimal Induced Universal Graphs for Bounded Degree Graphs

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    A graph UU is an induced universal graph for a family FF of graphs if every graph in FF is a vertex-induced subgraph of UU. For the family of all undirected graphs on nn vertices Alstrup, Kaplan, Thorup, and Zwick [STOC 2015] give an induced universal graph with O ⁣(2n/2)O\!\left(2^{n/2}\right) vertices, matching a lower bound by Moon [Proc. Glasgow Math. Assoc. 1965]. Let k=D/2k= \lceil D/2 \rceil. Improving asymptotically on previous results by Butler [Graphs and Combinatorics 2009] and Esperet, Arnaud and Ochem [IPL 2008], we give an induced universal graph with O ⁣(k2kk!nk)O\!\left(\frac{k2^k}{k!}n^k \right) vertices for the family of graphs with nn vertices of maximum degree DD. For constant DD, Butler gives a lower bound of Ω ⁣(nD/2)\Omega\!\left(n^{D/2}\right). For an odd constant D3D\geq 3, Esperet et al. and Alon and Capalbo [SODA 2008] give a graph with O ⁣(nk1D)O\!\left(n^{k-\frac{1}{D}}\right) vertices. Using their techniques for any (including constant) even values of DD gives asymptotically worse bounds than we present. For large DD, i.e. when D=Ω(log3n)D = \Omega\left(\log^3 n\right), the previous best upper bound was (nD/2)nO(1){n\choose\lceil D/2\rceil} n^{O(1)} due to Adjiashvili and Rotbart [ICALP 2014]. We give upper and lower bounds showing that the size is (n/2D/2)2±O~(D){\lfloor n/2\rfloor\choose\lfloor D/2 \rfloor}2^{\pm\tilde{O}\left(\sqrt{D}\right)}. Hence the optimal size is 2O~(D)2^{\tilde{O}(D)} and our construction is within a factor of 2O~(D)2^{\tilde{O}\left(\sqrt{D}\right)} from this. The previous results were larger by at least a factor of 2Ω(D)2^{\Omega(D)}. As a part of the above, proving a conjecture by Esperet et al., we construct an induced universal graph with 2n12n-1 vertices for the family of graphs with max degree 22. In addition, we give results for acyclic graphs with max degree 22 and cycle graphs. Our results imply the first labeling schemes that for any DD are at most o(n)o(n) bits from optimal

    A Dynamic Market Mechanism for Integration of Renewables and Demand Response

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    The most formidable challenge in assembling a Smart Grid is the integration of a high penetration of renewables. Demand Response, a largely promising concept, is increasingly discussed as a means to cope with the intermittent and uncertain renewables. In this paper, we propose a dynamic market mech- anism that reaches the market equilibrium through continuous negotiations between key market players. In addition to incor- porating renewables, this market mechanism also incorporates a quantitative taxonomy of demand response devices, based on the inherent magnitude, run-time, and integral constraints of demands. The dynamic market mechanism is evaluated on an IEEE 118 Bus system, a high fidelity simulation model of the Midwestern United States power grid. The results show how the proposed mechanism can be utilized to determine combinations of demand response devices in the presence of intermittent and uncertain renewables with varying levels of penetration so as to result in a desired level of Social Welfare.This work was supported in part by the National Science Foundation grants ECCS-1135815 and EFRI-1441301

    Experience with CO2 capture from coal flue gas in pilot-scale: Testing of different amine solvents

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    AbstractAs part of the EU project CASTOR, a 1 t/h CO2 absorption pilot plant has been erected at Esbjergværket (Esbjerg power station) in Denmark. The main purpose of the pilot plant is to demonstrate the post combustion capture technology in conjunction with a coal-fired power station. Additionally, the pilot plant has been used to test the performance of new energy efficient solvents and to validate modelling work. The pilot plant operates on a slipstream of flue gas from the power plant without any further pre- treatment. During the CASTOR project, four 1000-hours test campaigns have been conducted at the facility using conventional solvent, 30%-weight MEA as well as two novel amine-based solvents, CASTOR 1 and CASTOR 2. Among others, the test campaigns consisted of parameter variation tests and longer periods of continuous operation. This paper summarises the operation experience and some of the results obtained during the CASTOR project

    Functional Compost

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    The aim of the research program Functional Compost is to develop and test compost, which have been enriched with chitin, for plant growth promoting properties and to recognise specific mechanisms. Two types of compost were included in the program: source separated biodegradable municipal solid waste compost (DM = 62 %) and garden and park waste compost (DM = 66 %). Chitin was added in trace amounts during the maturity phase, combined with two levels of trace amounts immediately before adding the compost to the growth medium. The research program includes several parallel experiments. In experiment I, compost (20 vol. %) was added to soil (no plants) and incubated at 15 C for 5 month, under regular determination of microbial respiration and gross and net N mineralization. There was a significant increase in respiration due to chitin enrichment, which could not be explained by the amount of C derived from the chitin, which therefore suggest a priming effect. The N analyses are still being processed in the laboratory, but data are expected to be available at the conference. In experiment II, compost was mixed with sand, put into pots in a climate chamber, and spring barley seeds infected with Fusarium culmorum were sown in the pots. After 3 weeks of growth, the health of the plants was determined, and the chitinase activity in the sand was measured. The health of the plants and the chitinase activity was significantly higher in the treatments receiving municipal waste compared to the treatments receiving garden waste compost. However, there was no clear effect of the chitin enrichment. Additionally, the microbial community structure of the two types of compost, with and without early chitin, was determined by Denaturing Gradient Gel Electrophoresis (DGGE). There was a clear separation between compost types, and with or without early chitin amendment. Experiment III is a regular growth experiment, and is running right now. Compost has been incorporated into soil, put into pots in the greenhouse, and spring barley is grown for 2 month before determination for wet and dry weight and N uptake. Data from experiment III is expected to be available at the conference

    A Formalization of Linkage Analysis

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    In this report a formalization of genetic linkage analysis is introduced. Linkage analysis is a computationally hard biomathematical method, which purpose is to locate genes on the human genome. It is rooted in the new area of bioinformatics and no formalization of the method has previously been established. Initially, the biological model is presented. On the basis of this biological model we establish a formalization that enables reasoning about algorithms used in linkage analysis. The formalization applies both for single and multi point linkage analysis. We illustrate the usage of the formalization in correctness proofs of central algorithms and optimisations for linkage analysis. A further use of the formalization is to reason about alternative methods for linkage analysis. We discuss the use of MTBDDs and PDGs in linkage analysis, since they have proven efficient for other computationally hard problems involving large state spaces. We conclude that none of the techniques discussed are directly applicable to linkage analysis, however further research is needed in order to investigated whether a modified version of one or more of these are applicable

    A Formalization of Linkage Analysis

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    In this report a formalization of genetic linkage analysis is introduced. Linkage analysis is a computationally hard biomathematical method, which purpose is to locate genes on the human genome. It is rooted in the new area of bioinformatics and no formalization of the method has previously been established. Initially, the biological model is presented. On the basis of this biological model we establish a formalization that enables reasoning about algorithms used in linkage analysis. The formalization applies both for single and multi point linkage analysis. We illustrate the usage of the formalization in correctness proofs of central algorithms and optimisations for linkage analysis. A further use of the formalization is to reason about alternative methods for linkage analysis. We discuss the use of MTBDDs and PDGs in linkage analysis, since they have proven efficient for other computationally hard problems involving large state spaces. We conclude that none of the techniques discussed are directly applicable to linkage analysis, however further research is needed in order to investigated whether a modified version of one or more of these are applicable

    Checking Consistency of Pedigree Information is NP-complete (Preliminary Report)

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    Consistency checking is a fundamental computational problem in genetics. Given a pedigree and information on the genotypes of some of the individuals in it, the aim of consistency checking is to determine whether these data are consistent with the classic Mendelian laws of inheritance. This problem arose originally from the geneticists' need to filter their input data from erroneous information, and is well motivated from both a biological and a sociological viewpoint. This paper shows that consistency checking is NP-complete, even in the presence of three alleles. Several other results on the computational complexity of problems from genetics that are related to consistency checking are also offered. In particular, it is shown that checking the consistency of pedigrees over two alleles can be done in polynomial time

    Vesterbjerg: Tidligmiddel­alderlig landbebyggelse med begravede og nedkulede dyr

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    Udgravningen ved Vesterbjerg i Brovst afslørede en bebyggelse der dækkede 1,5 ha og inkluderede 44 bygninger, primært dateret til tidlig middelalder. Bemærkelsesværdige fund inkluderer to store enkeltskibede langhuse, hvor alle gårdens funktioner sandsynligvis har været under ét tag samt små vinkelformede toskibede bygninger. Den dominerende hustype syntes at være det enkeltskibede hus med rektangulær grundplan, selvom der var betydelig variation i husenes dimensioner, konstruktion og orientering. Udgravningen resulterede i en stor mængde dyreknogler, primært fra domesticerede arter. En hund var blevet gravlagt, mens en hoppe var blevet nedkulet i et hul efter en mislykket foling. En gennemgang af knoglematerialet antyder, at nogle af landsbyens dyr måske er blevet sendt til nærliggende markeder, hvorimod fx udtjente heste, til trods for kristendommens forbud mod spisning af hestekød, alligevel kunne ende på spisebordet
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