Exact renormalization group in Batalin--Vilkovisky theory

In this paper, inspired by the Costello's seminal work, we present a general formulation of exact renormalization group (RG) within the Batalin-Vilkovisky (BV) quantization scheme. In the spirit of effective field theory, the BV bracket and Laplacian structure as well as the BV effective action (EA) depend on an effective energy scale. The BV EA at a certain scale satisfies the BV quantum master equation at that scale. The RG flow of the EA is implemented by BV canonical maps intertwining the BV structures at different scales. Infinitesimally, this generates the BV exact renormalization group equation (RGE). We show that BV RG theory can be extended by augmenting the scale parameter space R to its shifted tangent bundle T[1]R. The extra odd direction in scale space allows for a BV RG supersymmetry that constrains the structure of the BV RGE bringing it to Polchinski's form. We investigate the implications of BV RG supersymmetry in perturbation theory. Finally, we illustrate our findings by constructing free models of BV RG flow and EA exhibiting RG supersymmetry in the degree -1 symplectic framework and studying the perturbation theory thereof. We find in particular that the odd partner of effective action describes perturbatively the deviation of the interacting RG flow from its free counterpart.Comment: 52 pages, no figures, introduction thoroughly rewritten, two new subsections adde

A DISCUSSION ON ASSURING SOFTWARE QUALITY IN SMALL AND MEDIUM SOFTWARE ENTERPRISES: AN EMPIRICAL INVESTIGATION

Under the studies of general core activities including software inspection, review and testing to achieve quality objectives in small-medium size enterprises (SMEs), the paper presents a contemporary view of such companies against quality measures. The results from a local empirical investigation of quality standards in the Turkish software industry are reported.Around 150 software companies have been approached from which 17 detailed feedback inform that in order to ensure software quality, standards including internationally recognized International Standards Organization (ISO) and Capability Maturity Model Integration (CMMI) are given credit. However the substantial workload and resources required to obtain them are also reported as serious; downscaled frameworks of such large models proposed in the literature are not well known by the SMEs either. The paper also discusses "work around" that bypasses such standards to ease delivery of products while keeping certificates as labels just to acquire new jobs for the business

Explorar performance com Apollo Federation

The growing tendency in cloud-hosted computing and availability supported a shift in soft ware architecture to better take advantage of such technological advancements. As Mono lithic Architecture started evolving and maturing, businesses grew their dependency on soft ware solutions which motivated the shift into Microservice Architecture. The same shift is comparable with the evolution of Monolithic GraphQL solutions which, through its growth and evolution, also required a way forward in solving some of its bot tleneck issues. One of the alternatives, already chosen and proven by some enterprises, is GraphQL Federation. Due to its nobility, there is still a lack of knowledge and testing on the performance of GraphQL Federation architecture and what techniques such as caching strategies, batching and execution strategies impact it. This thesis aims to answer this lack of knowledge by first contextualizing the different as pects of GraphQL and GraphQL Federation and investigating the available and documented enterprise scenarios to extract best practices and to better understand how to prepare such performance evaluation. Next, multiple alternatives underwent the Analytic Hierarchy Process to choose the best way to develop a scenario to enable the performance analysis in a standard and structured way. Following this, the alternative base solutions were analysed and compared to deter mine the best fit for the current thesis. Functional and non-functional requirements were collected along with the rest of the design exercise to enhance the solution to be tested for performance. Finally, after the required development and implementation work was documented, the so lution was tested following the Goal Question Metric methodology and utilizing tools such as JMeter, Prometheus and Grafana to collect and visualize the performance data. It was possible to conclude that indeed different caching, batching and execution strategies have an impact on the GraphQL Federation solution. These impacts do shift between positive (improvements in performance) and negative (performance hindered by strategy) for the different tested strategies.A tendência de crescimento da computação cloud-hosted apoiou uma mudança na arquite tura do software para tirar maior proveito desses avanços tecnológicos. Com a evolução e amadurecimento das arquiteturas monolíticas, as empresas aumentaram sua dependência nas soluções software que motivou a mudança e adoção de arquiteturas de micro serviços. O mesmo se verificou com a evolução das soluções monolíticas GraphQL que, com o seu crescimento e evolução, também requeriam soluções para resolver algumas das suas novas complexidades. Uma das alternativas de resolução, já aplicado e provado na indústria, é o GraphQL Federation. Devido ao seu recente lançamento, ainda não existe um conhecimento sólido na performance de uma arquitetura de GraphQL Federation e que técnicas como estratégias de caching, batching e execution tem impacto sobre a mesma. Esta tese tem como intuito responder a esta falha de conhecimento através de, primeira mente, contextualizar os diferentes aspetos de GraphQL e GraphQL Federations com a investigação de casos de aplicação na indústria, para a extração de boas práticas e compreender o necessário ao desenvolvimento de uma avaliação de performance. De seguida, múltiplas alternativas foram sujeitas ao Analytic Hierarchy Process para escolher a melhor forma de desenvolver um cenário/solução necessária a uma análise de performance normalizada e estruturada. Com isto em mente, as duas soluções base foram analisadas e comparadas para determinar a mais adequada a esta tese. Requisitos funcionais e não funcionais foram recolhidos, assim como todo o restante exercício de design necessário ao desenvolvimento da solução para testes de performance. Finalmente, após a fase de desenvolvimento ser concluída e devidamente documentada, a solução foi testada seguindo a metodologia Goal Question Metric, e aplicando ferramentas como JMeter, Prometheus e Grafana para recolher e visualizar os dados de performance. Foi possível concluir que, de facto, as diferentes estratégias de caching, batching e execution tem impacto numa solução GraphQL Federation. Tais impactos variam entre positivos (com melhorias em termos de performance) e negatives (performance afetada por estratégias) para as diferentes estratégias testadas

Moduli spaces of sheaves via affine Grassmannians

We develop a new method for analyzing moduli problems related to the stack of pure coherent sheaves on a polarized family of projective schemes. It is an infinite-dimensional analogue of geometric invariant theory. We apply this to two familiar moduli problems: the stack of $\Lambda$-modules and the stack of pairs. In both examples, we construct a $\Theta$-stratification of the stack, defined in terms of a polynomial numerical invariant, and we construct good moduli spaces for the open substacks of semistable points. One of the essential ingredients is the construction of higher dimensional analogues of the affine Grassmannian for the moduli problems considered.Comment: 58 pages, comments welcom

Supporting Software Development by an Integrated Documentation Model for Decisions

Decision-making is a vital activity during software development. Decisions made during requirements engineering, software design, and implementation guide the development process. In order to make decisions, developers may apply different strategies. For instance, they can search for alternatives and evaluate them according to given criteria, or they may rely on their personal experience and heuristics to make single solution claims. Thereby, knowledge emerges during the process of decision making, as the content, outcome, and context of decisions are explored by developers. For instance, different solution options may be considered to address a given decision problem. In particular, such knowledge is growing rapidly, when multiple developers are involved. Therefore, it should be documented to make decisions comprehensible in the future. However, this documentation is often not performed by developers in practice. First, developers need to find and use a documentation approach, which provides support for the decision making strategies applied for the decision to be documented. Thus, documentation approaches are required to support multiple strategies. Second, due to the collaborative nature of the decision making process during one or more development activities, decision knowledge needs to be captured and structured according to one integrated model, which can be applied during all these development activities. This thesis uncovers two important reasons, why the aforementioned requirements are currently not fulfilled sufficiently. First, it is investigated, which decision making strategies can be identified in the documentation of decisions within issue tickets from the Firefox project. Interestingly, most documented decision knowledge originates from naturalistic decision making, whereas most current documentation approaches structure the captured knowledge according to rational decision making strategies. Second, most decision documentation approaches focus on one development activity, so that for instance decision documentation during requirements engineering and implementation are not supported within the same documentation model. The main contribution of this thesis is a documentation model for decision knowledge, which addresses these two findings. In detail, the documentation model supports the documentation of decision knowledge resulting from both naturalistic and rational decision making strategies, and integrates this knowledge within flexible documentation structures. Also, it is suitable for capturing decision knowledge during the three development activities of requirements engineering, design, and implementation. Furthermore, a tool support is presented for the model, which allows developers to integrate decision capturing and documentation in their activities using the Eclipse IDE