This thesis reviews the method of Mafra, Schlotterer, and Stieberger (2011) for computing the full colour ordered N-point open superstring amplitude using the Pure Spinor formalism. We introduce relevant elements of super Yang-Mills theory and examine the basics of the Pure Spinor formalism, with a focus on tools for amplitude computation. We then define a series of objects with increasingly useful BRST transformation properties, which greatly simplify the calculations, and show how these properties can be determined using a diagrammatic method. Finally, we use the explicit four- and five-point amplitude computations as stepping stones to compute the general N-point amplitude, which factors into a set of kinematic integrals multiplying SYM subamplitudes.

Syftet med detta arbete är att utifrån ett fenomenologiskt livsvärldsperspektiv, utforska hur några professionella musiker upplever att de går till väga under sina instuderingsprocesser. För att belysa detta tar arbetet avstamp i följande forskningsfråga: Vilka övningsstrategier beskriver några professionella musiker att de använder sig av när de tillägnar sig ett för dem nytt material? För att uppnå syfte och forskningsfråga har tre kvalitativa intervjuer genomförts med tre professionella musiker. I resultatet framkommer en rad olika strategier vilka sorterats in i fem meningsenheter: Dagliga tekniska övningsstrategier, Noggranna förberedelser, Tidsplanering, Övriga strategier och Strävan efter utveckling. I diskussionen sätts dessa strategier i relation till bakgrundslitteratur och forskning samt till fenomenologi. / Syftet med detta arbete är att utifrån ett fenomenologiskt livsvärldsperspektiv, utforska hur några professionella musiker upplever att de går till väga under sina instuderingsprocesser. För att belysa detta tar arbetet avstamp i följande forskningsfråga: Vilka övningsstrategier beskriver några professionella musiker att de använder sig av när de tillägnar sig ett för dem nytt material? För att uppnå syfte och forskningsfråga har tre kvalitativa intervjuer genomförts med tre professionella musiker. I resultatet framkommer en rad olika strategier vilka sorterats in i fem meningsenheter: Dagliga tekniska övningsstrategier, Noggranna förberedelser, Tidsplanering, Övriga strategier och Strävan efter utveckling. I diskussionen sätts dessa strategier i relation till bakgrundslitteratur och forskning samt till fenomenologi.

Thesis (MSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: This thesis gives a broad overview of what artificial chemistries (ACs) are, a brief review of several ACs and their applications, and an in depth analysis of one speci c AC: the four-bit binary string system. The model designed by Banzhaf [1] for in silico examination was recreated using the Python programming language. The initial motivation was to identify an existing AC that could be used to elucidate the sequence-function relationship, which led to the simultaneous investigation of self-organization in AC systems [7]. The interest in sequence-function relationships stems from their importance for self-production of objects [35]. For self-replication to be possible in larger organizations, the components of the organization must be able to continuously produce themselves [3, 7]. We chose the four-bit binary string system for investigation because of its simple design and implementation, its ability to yield complex results from interactions between a small population of objects, and its analogy to the DNA{RNA{protein organisation. When a population of objects are allowed to continuously interact, self-production and self-organization occur, even in simple arti cial systems [7, 8]. The stability of the emergent organizations depends on the interactions of its components, which must be capable of self-production if they are to maintain the organization [27]. Self-production of objects depends on their sequence-function relationship, which determines their rate of replication when interacting with other objects. / AFRIKAANSE OPSOMMING: Hierdie tesis verskaf `n bree oorsig van die algemene aard van artifisiele chemies (ACs), `n kort opsomming van `n paar ACs en hul toepassings, en `n diepgaande analise van een spesifieke AC: die 4-bis binere stringstelsel. Die model wat Banzhaf [1] ontwerp het vir in silico eksperimentering is hier herskep in die Python programmeringstaal. Die aanvanklike motivering was om `n bestaande AC te identifiseer wat gebruik kon word om die sekwens-funksie verwantskap te ontrafel, en dit het gelei tot die gelyktydige ondersoek van self-organisasie in AC stelsels [7]. Ons belangstelling in sekwens-funksie verwantskappe spruit uit hul belang vir die selfproduksie van objekte [35]. Om selfreplisering in meer omvangryke organisasies moontlik te maak moet die komponente in staat wees om hulself eenstryk te produseer [3, 7]. Ons het `n 4-bis stelsel vir hierdie studie gekies omdat die ontwerp en implementering eenvoudig is, omdat interaksies binne `n klein populasie van objekte komplekse resultate gee, en omdat die stelsel se organisasie analoog aan die DNA-RNA-proteien organisasie is. Wanneer `n populasie van objekte toegelaat word om eenstryk op mekaar te reageer vind self-produksie en self-organisasie vanself plaas, selfs in eenvoudige artifsiele stelsels [7, 8]. Die stabiliteit van die emergente organisasies hang af van die interaksies tussen die komponente, wat self die vermoe tot selfproduksie moet he indien hulle die organisasie in stand wil hou [27]. Selfproduksie van objekte hang af van hul sekwens-funsieverwantskap, wat op hul beurt bepaal hoe vinnig hulle repliseer wanneer in interaksie met ander objekte.

Bridges with external post-tensioned tendons are considered to be more durable than bridges with internal tendons (tendons within the webs and flanges), because external tendons are easier to inspect. In addition, in the event that extensive corrosion damage is detected, it is possible to replace an external tendon. However, an appropriate inspection for detecting damage needs to be determined for external tendons. This investigation focuses on the vibration technique, which uses the dynamic properties of the external tendon to infer the effective prestress force. Four large-scale external tendons, designed to simulate one section of an external tendon between two deviators in a post-tensioned bridge, were tested. In the study, damage to the tendons was induced in a quantifiable fashion at a specific location and the tensile force was measured directly. In addition, free-vibration tests were conducted periodically. This provided a direct means of measuring the sensitivity of measured natural frequencies and measured tensile force to local damage. The measured data were correlated with an approximation of the stiff string vibration model. In addition to the laboratory specimens, field testing was conducted on a bridge with external post-tensioned tendons. The findings from the study show that a loss in tensile force was not linear with a loss in the cross-sectional area of the strand, which results from stress redistribution within the tendon. Also, the natural frequencies were much less sensitive to the level of induced damage than the tensile force. While the measured data from the laboratory data compared very well with the analytical model, the field measurements exhibited a much greater deviation from the model. Due to several factors, the difference between the laboratory specimens and the bridge tendons are believed to be caused by larger levels of inherent error in the model. The findings from the investigation support the notion that vibration testing is most appropriately used in comparing relative differences between peer tendons. / text

One of the phenomenal results emerging from string theory is the AdS/CFT correspondence or gauge-gravity duality: In certain cases a theory of gravity is equivalent to a "dual" gauge theory, very similar to the one describing non-gravitational interactions of fundamental subatomic particles. A difficult problem on one side can be mapped to a simpler and solvable problem on the other side using this correspondence. Thus one of the theories can be understood better using the other. The mapping between theories of gravity and gauge theories has led to new approaches to building models of particle physics from string theory. One of the important features to model is the phenomenon of confinement present in strong interaction of particle physics. This feature is not present in the gauge theory arising in the simplest of the examples of the duality. However this N = 4 supersymmetric Yang-Mills gauge theory enjoys the property of being integrable, i.e. it can be exactly solved in terms of conserved charges. It is expected that if a more realistic theory turns out to be integrable, solvability of the theory would lead to simple analytical expressions for quantities like masses of the hadrons in the theory. In this thesis we show that the existing models of confinement are all nonintegrable--such simple analytic expressions cannot be obtained. We moreover show that these nonintegrable systems also exhibit features of chaotic dynamical systems, namely, sensitivity to initial conditions and a typical route of transition to chaos. We proceed to study the quantum mechanics of these systems and check whether their properties match those of chaotic quantum systems. Interestingly, the distribution of the spacing of meson excitations measured in the laboratory have been found to match with level-spacing distribution of typical quantum chaotic systems. We find agreement of this distribution with models of confining strong interactions, conforming these as viable models of particle physics arising from string theory.

No description available.

本論文主要是在探討依序選擇四個字串之下，是否存在一策略使得第二或第四字串有較大的機會比第一或第三字串先出現，也就是所謂的後選優勢是否存在。 利用電腦計算，我們發現字串長度為4,5,6時後選優勢確實存在，而當字串長度大於等於或等於7時，我們則證明了若第一字串為(0,0,...,0),(0,0,...,0,1),(1,1,...,1)或(1,1,...,1,0)時，後選者優勢亦存在。 / In the thesis, we consider about the first occurrence of four strings decided sequentially with teams. Team 1 consists string 1 and string 3; team 2 consists string 2 and string 4. It is interested in whether or not team 2 whose strings are decided after first string and third string are given separately gets an advantage in appearing with larger probability.Namely, given any string 1, we want to find a string 2 such that any string 3 corresponds to at least one string (string 4) making a larger probability for team 2 in appearing earlier than team 1. Based on the result from computer calculation, team 2 advantage over team 1 when the string length is 4, 5, and 6. This thesis also shows that team 2 gets an advantage for cases where string 1 is (0,0,...,0), (0,0,...,0,1), (1,1,...,1), (1,1,...,1,0) ,when the string length is larger than 6.

Denna uppsats syftar till att utveckla en förståelse för hur stråkinstrumentundervisning kan bedrivas då syftet är att lära ut en ergonomisk riktig spelteknik som förebygger hälsoproblem. Fokus i studien har varit på nybörjarundervisning samt HUR elever spelar. Studien har genomförts med hjälp av kvalitativ metod. Sex ergonomiskt kunniga och intresserade musiker och pedagoger har intervjuats. Deras specialområden är musikerergonom, sjukgymnast, kontrabasist, forskare, alexandertekniklärare och cellopedagog. Den kunskapsöversikt som presenteras i uppsatsen handlar om förhindrande av musikrelaterade hälsoproblem, utveckling av en fri spelteknik samt några pedagogiska konsekvenser utifrån fallstudier som gjorts på barn. Alexanderteknik, som bland annat handlar om effektiv muskelanvändning och ändring av felaktiga vanor, utgör den teoretiska utgångspunkten för studien. Resultatet visar bland annat att stråkinstrumentundervisning på ergonomisk grund ska utgå från läraren och dennes interaktion med eleven och kräver att läraren har kunskap och medvetenhet om ämnet ergonomi. Vidare visar resultatet på betydelsen av att i undervisningen prioritera kvalitet framför kvantitet, att anpassa undervisningen efter elevens olika muskulära och psykiska förutsättningar och att se eleven i ett helhetsperspektiv. Exempel på viktiga moment i tillvägagångssätt för stråkundervisning på ergonomisk grund handlar om att bevaka elevens lust och ha en sund balans i progressionen. / The purpose of this study is to develop an understanding in how teaching strings can emphasize an ergonomic way of playing, thus preventing health problems. Focus has been how to teach beginners as well as HOW to play. The study has been carried out with a qualitative method. Six musicians and teachers with ergonomics as a special field have been interviewed. They are a physiotherapist, a double bassist, a researcher, a teacher in Alexander Technique and a teacher in cello. The findings of the study deal with the prevention of musician-related injuries, developing a free playing technique, and educational consequences from a few case studies of children. The Alexander Technique, which among other aspects, deals with the effective use of muscles and changing wrong habits, is the theoretical starting point of the study. The result indicates, among other things, evidence that teaching strings in an ergonomic perspective should start with the teacher and his/her interaction with the pupil, and requires that the teacher possesses a knowledge and awareness of ergonomics. Furthermore, the result gives evidence of the importance in giving priority to quality instead of quantity, adjusting the teaching to the pupil’s different physical and psychical conditions and also viewing the pupil in a comprehensive perspective. Checking the pupil’s mindset and having a good balance of the progression, are examples of important elements in teaching strings.

In the first part of this thesis we study baryonic U(1) symmetries dual to Betti multiplets in the AdS_4/CFT_3 correspondence for M2 branes at Calabi-Yau four-fold singularities. Such short multiplets originate from the Kaluza-Klein compactification of eleven-dimensional supergravity on the corresponding Sasaki-Einstein seven-manifolds. Analysis of the boundary conditions for vector fields in AdS_4 allows for a choice where wrapped M5 brane states carrying non-zero charge under such symmetries can be considered. We begin by focusing on isolated toric singularities without vanishing six-cycles, which we classify, and propose for them field theory duals. We then study in detail the cone over the well-known Sasaki-Einstein space Q^111, which is a U(1) fibration over CP^1 x CP^1 x CP^1. The boundary conditions considered are dual to a CFT where the gauge group is U(1)^2 x SU(N)^4. We find agreement between the spectrum of gauge-invariant baryonic-type operators in this theory and M5 branes wrapping five-cycles in the Q^111 space. Moreover, the physics of vacua in which these symmetries are spontaneously broken precisely matches a dual gravity analysis involving resolutions of the singularity, where we are able to match condensates of the baryonic operators, Goldstone bosons and global strings. We then study the implications of turning on a closed three-form with non-zero periods through torsion three cycles in the Sasaki-Einstein manifold. This three-form, otherwise known as torsion G-flux, non-trivially affects the supergravity dual of Higgsing, and we show that the supergravity and field theory analyses precisely match in an example based on the Sasaki-Einstein manifold Y^1,2(CP^2), which is a S^3 bundle over CP^2. We then explain how the choice of M-theory circle in the background can result in exotic renormalization group flows in the dual field theory, and study this in detail for the Sasaki-Einstein manifold Y^1,2(CP^2). We also argue more generally that theories where the resolutions have six-cycles are expected to receive non-perturbative corrections from M5 brane instantons. We give a general formula relating the instanton action to normalizable harmonic two-forms, and compute it explicitly for the Sasaki-Einstein Q^222 example, which is a Z_2 orbifold of Q^111 in which the free Z_2 quotient is along the R-symmetry U(1) fibre. The holographic interpretation of such instantons is currently unclear. In the second part of this thesis we study the breaking of baryonic symmetries in the AdS_5/CFT_4 correspondence for D3 branes at Calabi-Yau three-fold singularities. This leads, for particular vacuum expectation values, to the emergence of non-anomalous baryonic symmetries during the renormalization group flow. We identify these vacuum expectation values with critical values of the NS-NS B-field moduli in the dual supergravity backgrounds. We study in detail the C^3/Z_3 orbifold theory and the dual supergravity backgrounds that correspond to the breaking of the emerging baryonic symmetries, and identify the expected Goldstone bosons and global strings in the infra-red. In doing so we confirm the claim that the emerging symmetries are indeed non-anomalous baryonic symmetries.

This portfolio presents seven compositions composed for different instrumental and vocal forces, accompanied by a commentary and recordings of some of these works. Across the seven pieces there has been a concern with building longer-term structures; establishing a stronger developmental style; and with moving towards a more systematised approach to harmony as a way of creating a harmonic language that can underpin development more efficiently.  Several of the works show a direct engagement with the issue of form, which is approached from the perspective of Classical models, the listener’s perception and in the context of a highly chromatic harmonic language.  In contrast, two works (<i>Aubade</i> and <i>So Turn Your Heart</i>) engage more directly with diatonic models of harmony. The dominant concern across all the works presented has been the desire to create developmental, direct music in which the notion of transformation, rather than stasis and ritual, are of paramount importance.  From a melodic, harmonic and structural point of view each work represents different ways in which this has been attempted. The commentary that accompanies the works explores many of these ideas in more detail as well as setting out the origins and development of each composition. There is also an explanation as to how the initial material was decided upon and utilised during the compositional process. The commentary then concludes with a summary of what has been achieved over the course of the programme and where this might lead in the future.