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Color-Weakness Compensation using Riemann Normal CoordinatesOshima, Satoshi, Mochizuki, Rika, Lenz, Reiner, Chao, Jinhui January 2012 (has links)
We introduce normal coordinates in Riemannspaces as a tool to construct color-weak compensation methods.We use them to compute color stimuli for a color weakobservers that result in the same color perception as theoriginal image presented to a color normal observer in the sensethat perceived color-differences are identical for both. Thecompensation is obtained through a color-difference-preservingmap, i.e. an isometry between the 3D color spaces of a colornormaland any given color-weak observer. This approach usesdiscrimination threshold data and is free from approximationerrors due to local linearization. The performance is evaluatedwith the help of semantic differential (SD) tests. / Swedish Foundation for Strategic Research through grant IIS11-0081. / European Community’s Seventh Framework Programme FP7/2007-2013 - Challenge 2 Cognitive Systems, Interaction, Robotics - under grant agreement No 247947 - GARNICS.
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Immobilized lipodisks as model membranes in high-throughput HPLC-MS analysisMeiby, Elinor, Morin Zetterberg, Malin, Ohlson, Sten, Agmo Hernández, Víctor, Edwards, Katarina January 2013 (has links)
Lipodisks, also referred to as polyethylene glycol (PEG)-stabilized bilayer disks, have previously been demonstrated to hold great potential as model membranes in drug partition studies. In this study, an HPLC-MS system with stably immobilized lipodisks is presented. Functionalized lipodisks were immobilized on two different HPLC support materials either covalently by reductive amination or by streptavidin-biotin binding. An analytical HPLC column with immobilized lipodisks was evaluated by analysis of mixtures containing 15 different drug compounds. The efficiency, reproducibility, and stability of the system were found to be excellent. In situ incorporation of cyclooxygenase-1 (COX-1) in immobilized lipodisks on a column was also achieved. Specific binding of COX-1 to the immobilized lipodisks was validated by interaction studies with QCM-D. These results, taken together, open up the possibility of studying ligand interactions with membrane proteins by weak affinity chromatography. / <p>De två (2) första författarna delar förstaförfattarskapet.</p>
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Elastic Scattering Phenomena in Molecularly-linked Gold Nanoparticle FilmsDunford, Jeffrey Loren 19 January 2009 (has links)
We have investigated the conductance, g, of 1,4-butanedithiol linked Au nanoparticle films as a function of temperature, T, bias potential, V, and applied magnetic field, B. An interesting temperature dependence is observed for non-metallic films with thicknesses just below a critical film thickness: g ~ exp [-(T_0/T)^(1/2)] for 20 K < T < 300 K. We show that this temperature dependence is incompatible with an Efros-Shklovskii "variable range hopping" model, since "hopping distances" are too large to be consistent with tunneling processes, and tend to scale with size of super-clusters of molecularly-linked nanoparticles. We propose a "quasilocalized hopping" model based on competition between single-electron charging of super-clusters and electron backscattering within super-clusters to explain the observed temperature dependence. Various electron scattering time scales are extracted from magnetoconductance data using a modified "weak localization" model. Elastic scattering time scales are comparable to those required for an electron to traverse a nanoparticle, while inelastic and spin-orbit scattering time scales are consistent with those found in studies of conventionally-prepared granular Au films.
At interfaces between metallic 1,4-butanedithiol-linked Au nanoparticle films and conventional superconductors, we find that g consistently exhibits peaks, as well as oscillations, that depend simultaneously on both V and B. Such peaks and correlated conductance oscillations are predicted by an enhanced Andreev reflection process due to disorder-driven elastic scattering and electron-hole interference in the nanoparticle film. While oscillations have been predicted by a so-called "reflectionless tunneling" model, they have not been observed at other normal-superconductor interfaces. We speculate that oscillations are observable in this system due to synthetically controlled uniformity of elastic scattering length (i.e., nanoparticle diameter) and a reduced number of current-carrying pathways, especially near the interface. Contrary to predictions of existing "reflectionless tunneling" models, we find that the periods of oscillation in B decrease as T increases. This suggests that the area of interfering pathways increases with T. We propose that this increasing area can be attributed to magnetic field penetration into the superconductor. Conductance data agrees remarkably well with known temperature dependence of penetration depth predicted by BCS theory. Our study shows that this additional region of flux must be considered in experimental and theoretical studies of "reflectionless tunneling", and underscores the utility of molecularly-linked nano\-particle films as a platform for studying charge transport.
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Elastic Scattering Phenomena in Molecularly-linked Gold Nanoparticle FilmsDunford, Jeffrey Loren 19 January 2009 (has links)
We have investigated the conductance, g, of 1,4-butanedithiol linked Au nanoparticle films as a function of temperature, T, bias potential, V, and applied magnetic field, B. An interesting temperature dependence is observed for non-metallic films with thicknesses just below a critical film thickness: g ~ exp [-(T_0/T)^(1/2)] for 20 K < T < 300 K. We show that this temperature dependence is incompatible with an Efros-Shklovskii "variable range hopping" model, since "hopping distances" are too large to be consistent with tunneling processes, and tend to scale with size of super-clusters of molecularly-linked nanoparticles. We propose a "quasilocalized hopping" model based on competition between single-electron charging of super-clusters and electron backscattering within super-clusters to explain the observed temperature dependence. Various electron scattering time scales are extracted from magnetoconductance data using a modified "weak localization" model. Elastic scattering time scales are comparable to those required for an electron to traverse a nanoparticle, while inelastic and spin-orbit scattering time scales are consistent with those found in studies of conventionally-prepared granular Au films.
At interfaces between metallic 1,4-butanedithiol-linked Au nanoparticle films and conventional superconductors, we find that g consistently exhibits peaks, as well as oscillations, that depend simultaneously on both V and B. Such peaks and correlated conductance oscillations are predicted by an enhanced Andreev reflection process due to disorder-driven elastic scattering and electron-hole interference in the nanoparticle film. While oscillations have been predicted by a so-called "reflectionless tunneling" model, they have not been observed at other normal-superconductor interfaces. We speculate that oscillations are observable in this system due to synthetically controlled uniformity of elastic scattering length (i.e., nanoparticle diameter) and a reduced number of current-carrying pathways, especially near the interface. Contrary to predictions of existing "reflectionless tunneling" models, we find that the periods of oscillation in B decrease as T increases. This suggests that the area of interfering pathways increases with T. We propose that this increasing area can be attributed to magnetic field penetration into the superconductor. Conductance data agrees remarkably well with known temperature dependence of penetration depth predicted by BCS theory. Our study shows that this additional region of flux must be considered in experimental and theoretical studies of "reflectionless tunneling", and underscores the utility of molecularly-linked nano\-particle films as a platform for studying charge transport.
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Toward an Understanding of "Weak Signals" of Technological Change and Innovation in the Internet IndustryNoriega Velasco, Julio January 2013 (has links)
Identifying the emergence and development of new technologies has become an essential ability for firms competing in dynamic environments. Nonetheless, current technology intelligence practices are unstructured and vaguely defined. Moreover, the existing literature in future technology studies lacks strong, systematic explanations of what technologies are, where technologies come from, and how new technologies emerge and evolve. The present study builds on Structuration Theory, and proposes the structurational model of emerging technologies (SMET). The SMET suggests not only an ongoing view of technologies as social objects, but also a process for thinking through scientifically the complex, multidimensional and emergent dynamic of social and technological change. The SMET proposes that the emergence and development of a new technology can be tracked by examining systematically and collectively the extent of development of its technology-related social structure – its degree of structuration. The degree of structuration of a technology is an ongoing process instantiated in social practices, and can be observed through visible patterns or specific social outcomes of systemic activity organized in three analytical dimensions: structures of meaning, power, and legitimacy. The SMET assumes that the conceptual initiation of a new technology triggers new patterns of social activity or a signal of technological change; thus, the variation in the slope or trajectory of the degree of structuration of a technology may indicate an early signal of technological change. The SMET sets a foundation for identifying early signals of technological change when it is used on a systematic basis.
Empirically, the study conducted an exploratory case study in the Internet industry. The study employed a sequential transformative mixed method procedure, and relied on 77 Internet experts to create retrospectively a systematic and collective interpretation of the Internet industry in the last ten (10) years. The test of hypotheses was based on only seven (7) Internet technologies due to time and instrumental constraints. The results confirm the fundamental relationships among constructs in the model, and support, thus, the SMET. The degree of structuration of a technology is revealed as a process independent of individuals’ participation in the enactment of a technology. Technological outcomes are explained by the extent of development of structures of meaning, power, and legitimacy (i.e., the degree of structuration of a technology). Moreover, influential technological outcomes shape individuals’ perspectives over time – i.e., the structurational effect. Hence, the study not only provides evidence that supports this novel theoretical framework, but also illustrates methodologically how to identify the emergence and development of new technologies. Likewise, the study discusses the implications of these results for technology management practices (e.g., product and technology development, innovation policies, and technology transfer activities). Lastly, the study recognizes limitations and suggests further research avenues.
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Inferred Weak Rock Mass Classification for Stope Design2013 July 1900 (has links)
Empirical design methods are commonly used for rock mechanics evaluations. An appropriate method of rock mass classification is required to use these empirical methods. There are limitations for rock mass classification methods when access to the ore zone is restricted.
The Cameco Corporation Eagle Point Mine in northern Saskatchewan, Canada, uses the longhole open stope mining method for the recovery of uranium ore. The Modified Dilution graph is used for the prediction of stope hanging wall dilution. The mine currently uses a rock mass classification based on an estimate of the alteration and strength of a rock mass from geological drift mapping. Since this method is highly subjective, point load testing of diamond drill hole core was completed to attempt to correlate the alteration and strength of different rock types to remove the user subjectivity. The results of the testing indicated a general trend of decreasing rock strength with increasing alteration, albeit with considerable scatter.
A repeatable, standardized method of evaluating the stope geometry and inferred rock mass classification for reconciliation purposes was developed. The standardized stope evaluation method removes significant subjectivity currently involved in estimates of stope geometries and the magnitude of dilution. A new lithology based method for interpreting the mine specific geological alteration and strength classification system was developed based on several sources of rock mass classification observations. This resulted in a correlation linking individual rock mass property descriptions between different classification systems for an improved estimate of the Q’ classification value. This improved method of estimating the rock classification Q’ value, as well as conventional techniques for linking classification systems, was used in a stope reconciliation process to predict open stope dilution.
Twenty-seven stope reconciliation case histories were documented and used to compare predicted and measured dilution, based on three different approaches for estimating rock mass classification values. The results showed a minor improvement in dilution prediction using the approach developed in this study. The systematic stope reconciliation and rock mass classification approach did highlight areas in the weak pegmatoidal rocks where improved rock classification estimates should be investigated.
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IDROTT FÖR ALLA? : En fallstudie om inkludering i idrottsföreningar i UmeåBjuhr, Rebecka January 2012 (has links)
Föreningsidrotten är en stor del av det svenska samhället och kan vara en plats som främjar en ömsesidig integration mellan svenskfödda och nyligt invandrade. Samtidigt som idrottsvärlden kan vara en plats för god gemenskap kan det även vara en plats för utslagning och exkludering. Syftet med studien har två delar. Första delen handlar om att undersöka varför och hur idrottsföreningar i Umeå agerar gällande inkludering av medlemmar generellt. Därefter syftar studien till att analysera dessa idrottsföreningars förhållningssätt och agerande i förhållande till gruppen nyligt invandrade specifikt. Den teoretiska ramen bygger på inkludering i förhållande till Granovetters begrepp weak ties som belyser vikten av svaga sociala band för att knyta samman heterogena grupper och skapa en sammanhållning som överbryggar bland annat kulturella gränser. Metodens utgångspunkt är kvalitativ ur två aspekter: den första avser att det är en fallstudie som handlar om idrottsföreningar i Umeå. Den andra handlar om att uppsatsens centrala empiriska material har samlats in genom kvalitativa intervjuer med centrala aktörer och aktiva personer inom både lag- och individuella idrotter. Resultatet är brett men handlar om att idrottsföreningarnas struktur, ”sätt att tänka” och föreningsaktivas agerande kan fungera exkluderande eftersom det skapas barriärer som nyligt invandrade har svårt att komma förbi och därmed försvåras ett deltagande i idrottsföreningar. Barriärerna har teoretiskt beskrivits utifrån Stigendals definition av målgruppsbarriär, ordningsbarriär samt resursbarriär. Att uppnå inkludering är att förmedla en upplevelse av delaktighet och gemenskap inom föreningen. Problem uppstår i ett första skede på grund av målgruppsbarriärer och rekryteringsmetoder. Studien har uppmärksammat att det förekommer en kollektivisering av nyanlända som grupp, en andrafiering görs och fungerar i sig som en uteslutande mekanism vilket tyder på att det finns en strukturell diskriminering av ”de andra”. Däremot i de fall där nyanlända har inkluderats visar det sig att de barriärer och hinder som annars beskrivits har minskat eller försvunnit. Den lyckade interaktionen kan förklaras med att svaga band som skapas i sociala sammanhang fungerar som broar mellan sociala grupperingar och resulterar inte bara i att nätverken blir större utan även att fler ges möjligheten till att inkluderas. En kumulativ effekt av inkludering visar sig och en kollektivisering av nyligt invandrade kan bli svagare. / In i Umeå
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Evaluation of Rate Constants from Protein-Ligand Interactions with Weak Affinity ChromatographyJönsson, Daniel January 2012 (has links)
The paradigm of drug discovery have been to find the strongest possible binder to the target by high-throughput screening (HTS) but high affinity interactions are related to low kinetic off rates and thus result in severe side-effects and non-approved drugs. Lead molecules working in a transient manner (KD > µM) will allow for rapid off rates and possibly less side-effects. In this study the peak profile method applied to weak affinity chromatography (WAC) was evaluated as a simple way to provide the kinetics of the interaction and thereby allowing for high-throughput determinations. In the peak profile formula all band-broadening effects except the stationary mass transfer is subtracted which simplifies the calculations for the kinetics of the interaction tremendously. The technique was evaluated by screening of 3 different benzamidines at 3 linear flow-rates using zonal chromatography and human α-thrombin as immobilized target protein. The kinetics of the interaction could unfortunately not be determined. This was possibly due to the flow-rates not being high enough as indicated by a low critical ratio (η < 1). Higher flow-rates would increase the contribution to band-broadening due to kinetic effects but would also require more precise estimation of peak variance.
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The weak language learner : a study of ways of taking weak language learners into consideration in classAxelsson, Susanna January 2007 (has links)
English is taught as a compulsory second language in Swedish schools and is one of three core subjects needed to be passed in order to receive a leaving certificate. Statistics show that 6.9% of the students do not aquire proficiency enough to receive a G (pass) in English in grade nine. The aim of this study is to investigate to what extent weak language learners are considered in the English classroom and if compensatory aids are used to further support their learning conditions. The method used for the study is qualitative interviews which were semi-structured. Four interviews with English teachers were conducted within the same municipality. The result shows that there are aspects that can be considered in order to provide better opportunities for weak language learners within the English classroom as well as outside the English classroom. Some teachers find it difficult to separate lack of motivation from lack of knowledge which makes discovering the students as early as possible important. In the English classroom weak language learners can be supported by smaller discussion groups since one problem seems to be oral skills. A connection to Swedish can be observed and students with difficulties in reading and writing in their native language experience more problems when learning English. The interviewees state the importance of first focusing on oral skills in the target language, before introducing written skills. Regarding support outside the English classroom the investigation shows that optional English, parents and homework are important features. In the optional English class weaker language learners get an opportunity to speak and revise previous blanks of knowledge. Parents are important for showing their children that they find English important but also for supporting the children while doing homework. Concerning compensatory aids, most teachers did not use them nor had they knowledge enough about available aids. The most frequently used aid was a CD where texts are recorded.
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Convergence Analysis for Inertial Krasnoselskii-Mann Type Iterative AlgorithmsHuang, Wei-Shiou 16 February 2011 (has links)
We consider the problem of finding a common fixed point of an infinite family ${T_n}$
of nonlinear self-mappings of a closed convex subset $C$ of a real Hilbert space $H$. Namely,
we want to find a point $x$ with the property (assuming such common fixed points exist):
[
xin igcap_{n=1}^infty ext{Fix}(T_n).
]
We will use the Krasnoselskii-Mann (KM) Type inertial iterative algorithms of the form
$$ x_{n+1} = ((1-alpha_n)I+alpha_nT_n)y_n,quad
y_n = x_n + eta_n(x_n-x_{n-1}).eqno(*)$$
We discuss the convergence properties of the sequence ${x_n}$ generated by this algorithm (*).
In particular, we prove that ${x_n}$ converges weakly to a common fixed point of the family
${T_n}$ under certain conditions imposed on the sequences ${alpha_n}$ and ${eta_n}$.
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