Even spin minimal model holography

The even spin W^e_\infty algebra that is generated by the stress energy tensor together with one Virasoro primary field for every even spin s \geq 4 is analysed systematically by studying the constraints coming from the Jacobi identities. It is found that the algebra is characterised, in addition to the central charge, by one free parameter that can be identified with the self-coupling constant of the spin 4 field. We show that W^e_\infty can be thought of as the quantisation of the asymptotic symmetry algebra of the even higher spin theory on AdS_3. On the other hand, W^e_\infty is also quantum equivalent to the so(N) coset algebras, and thus our result establishes an important aspect of the even spin minimal model holography conjecture. The quantum equivalence holds actually at finite central charge, and hence opens the way towards understanding the duality beyond the leading 't Hooft limit.Comment: 32 pages, v2: reference added, minor changes in tex

High-pressure Debye-Waller and Grueneisen parameters of Au and Cu

The lattice vibrations are determined in the quasi-harmonic approximation for elemental Au and Cu to twice their normal density by first-principles electronic band-structure calculations. It is found for these materials that the important moments of the phonon density of states can be obtained to high accuracy from short-ranged force constant models. We discuss the implications for the Grueneisen parameters on the basis of calculated phonon moments and their approximations by using bulk moduli and Debye-Waller factors.Comment: 4 pages, 2 figures to appear in the proceedings of the 13th APS Topical Conference on Shock Compression of Condensed Matter (scheduled for April 2004

Are they lit? Developing, testing, and implementing an instrument to measure artificial intelligence literacy

This thesis presents the development and application of the "Scale for the assessment of non-experts' AI literacy" (SNAIL). Artificial intelligence (AI) is increasingly influencing various aspects of daily life and is being applied more and more frequently in professional contexts. To achieve a beneficial interaction between non-experts (i.e., individuals without specific AI education) and AI, a certain set of basic AI competencies is necessary. These basic competencies are commonly called "AI literacy" and have been the focus of intensive research in recent years. A particular branch of AI literacy research focuses on the reliable and valid measurement of AI literacy. Early AI literacy studies used unvalidated questionnaires, which were not suitable for reliably determining subjects’ AI literacy. Some researchers, including myself, have therefore started to develop measurement instruments for AI literacy that meet psychometric quality criteria. When this research project was registered and planned, there were no validated instruments for measuring AI competence. Therefore, I conducted a Delphi expert study in which an initial item set for assessing AI literacy was generated through three iterative Delphi rounds. In this initial study, particular emphasis was placed on the content validity of the items, aiming to create a set of questions that would cover the entire field of AI literacy without exceeding its scope. Afterwards, the item set was presented to a large sample of non-experts, who assessed their individual AI literacy using the items created in the first study. Based on the collected data, I conducted an exploratory factor analysis, which examined both the underlying factor structure and reduced the number of items. The result of this second study was the final SNAIL questionnaire. As a subsequent intermediate step, an investigation was conducted into the extent to which the adapted SNAIL could be suitable for evaluating AI courses. The adaptation involved two steps: firstly, the items were systematically translated from English to German. Secondly, all items were presented in both a retrospective version (assessing AI literacy before the start of the AI course) and a post-version (assessment after the completion of the course). Specific statistical methods that are suitable for evaluating learning outcomes were employed to identify strengths and weaknesses of the evaluated course. Finally, a large-scale study was conducted, in which SNAIL was used for the first time to assess the AI literacy of a specific subgroup of non-experts. For this purpose, both SNAIL and a scale for assessing "attitudes towards AI" (ATAI) were distributed to medical students from two German medical schools. Conducting a confirmatory factor analysis revealed that the original three-factor model showed a good model fit for this new data set. At the conclusion of this thesis, avenues for further development and enhancement of SNAIL are presented. One potential area for improvement is to reduce the number of items in the final SNAIL questionnaire to increase the scale’s efficiency while maintaining sufficient reliability of the subscales. Finally, I take another look at AI literacy research as a whole in order to identify potential research directions associated with SNAIL that extend beyond questionnaire development

Disorder control in crystalline GeSb2Te4 and its impact on characteristic length scales

Crystalline GeSb2Te4 (GST) is remarkable material, as it allows to continuously tune the electrical resistance by orders of magnitude without involving a phase transition or stoichiometric changes, just by altering the short-range order. While well-ordered specimen are metallic, increasing amounts of disorder can eventually lead to an insulating state with vanishing conductivity in the 0K limit, but a similar number of charge carriers. These observations make disordered GST one of the most promising candidates for the realization of a true Anderson insulator. While so far the low-temperature properties have mostly been studied in films of small grain size, here a sputter-deposition process is employed that enables preparation of a large variety of these GST states including metallic and truly insulating ones. By growing films of GST on mica substrates, biaxially textured samples with huge grain sizes are obtained. A series of these samples is employed for transport measurements, as their electron mean free path can be altered by a factor of 20. Yet, the mean free path always remains more than an order of magnitude smaller than the lateral grain size. This proves unequivocally that grain boundaries play a negligible role for electron scattering, while intragrain scattering, presumably by disordered vacancies, dominates. Most importantly, these findings underline that the Anderson insulating state as well as the system's evolution towards metallic conductivity are indeed intrinsic properties of the material

Resolving Inconsistencies in Declarative Process Models based on Culpability Measurement

Contrary to traditional process models, declarative process models define a set of declarative constraints to specify the behavior which a process should adhere to. In the scope of process mining, declarative process discovery aims to derive such constraint sets from event logs. Here, a problem for current discovery techniques is that of inconsistency. That is, dependent of certain event log characteristics, the derived constraint set may contain contradictory constraints. This in turn however makes the discovered model unusable, as contradictory constraints make it impossible to execute declarative process models, thus hampering previous process discovery efforts. In this work, we present an approach for resolving inconsistencies in declarative process models, based on methods from the scientific field of inconsistency measurement. We introduce our approach algorithm and evaluate its feasibility with data sets of the BPI Challenge 2017

Teaching the Chief Information Officers: An Assessment of the Interrelations within their Skill Set

Due to the high volatility in the field of information technology (IT) and the rapid technological advancements, all IT professionals constantly have to be able to evaluate trends and put them into context. This is especially true for those who fulfill the role of a company’s chief information officer (CIO). But if there is a gap between the required set of skills and those needed, training becomes necessary. In order to plan training programs, one has to know the skill set of current CIOs. We investigate this by conducting workshops with 21 CIOs from a diverse set of companies. The purpose of this paper is to better understand the skill items of CIOs and how they interrelate

Let a Single FLWOR Bloom

To globally optimize execution plans for XQuery expressions, a plan generator must generate and compare plan alternatives. In proven compiler architectures, the unit of plan generation is the query block. Fewer query blocks mean a larger search space for the plan generator and lead to a generally higher quality of the execution plans. The goal of this paper is to provide a toolkit for developers of XQuery evaluators to transform XQuery expressions into expressions with as few query blocks as possible. Our toolkit takes the form of rewrite rules merging the inner and outer FLWOR expressions into single FLWORs. We focus on previously unpublished rewrite rules and on inner FLWORs occurring in the For, Let, and Return clauses in the outer FLWOR

Cep70 and Cep131 contribute to ciliogenesis in zebrafish embryos.

BACKGROUND: The centrosome is the cell's microtubule organising centre, an organelle with important roles in cell division, migration and polarity. However, cells can divide and flies can, for a large part of development, develop without them. Many centrosome proteins have been identified but the roles of most are still poorly understood. The centrioles of the centrosome are similar to the basal bodies of cilia, hair-like extensions of many cells that have important roles in cell signalling and development. In a number of human diseases, such Bardet-Biedl syndrome, centrosome/cilium proteins are mutated, leading to polycystic kidney disease, situs inversus, and neurological problems, amongst other symptoms. RESULTS: We describe zebrafish (Danio rerio) embryos depleted for two uncharacterised, centrosome proteins, Cep70 and Cep131. The phenotype of these embryos resembles that of zebrafish mutants for intraflagellar transport proteins (IFTs), with kidney and ear development affected and left-right asymmetry randomised. These organs and processes are those affected in Bardet-Biedl syndrome and other similar diseases. Like these diseases, the root cause of the phenotype lies, in fact, in dysfunctional cilia, which are shortened but not eliminated in several tissues in the morphants. Centrosomes and basal bodies, on the other hand, are present. Both Cep70 and Cep131 possess a putative HDAC (histone deacetylase) interacting domain. However, we could not detect in yeast two-hybrid assays any interaction with the deacetylase that controls cilium length, HDAC6, or any of the IFTs that we tested. CONCLUSION: Cep70 and Cep131 contribute to ciliogenesis in many tissues in the zebrafish embryo: cilia are made in cep70 and cep131 morphant zebrafish embryos but are shortened. We propose that the role of these centrosomal/basal body proteins is in making the cilium and that they are involved in determination of the length of the axoneme.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are