COMPARISON OF OBJECT-ORIENTED PROGRAMMING AND DATA-ORIENTED DESIGN FOR IMPLEMENTING TRADING STRATEGIES BACKTESTER

This research proposes a way to accelerate backtesting of trading strategies using data-oriented design (DOD). The research discusses the differences between DOD and object-oriented approach (OOP), which is the most popular at the current moment. Then, the paper proposes efficient way to parallelize a backtesting using DOD. Finally, this research provides a performance comparison between DOD and OOP backtester implementations on the example of typical technical indicators. The comparison shows that use of DOD can speed up the process of quantitative features calculation up to 33% and allows for parallelization scheme that better utilizes resources in multiprocessor systems

Fireside: Creating an immersive historical narrative through video games

Applied project submitted to the Department of Computer Science and Information Systems, Ashesi University, in partial fulfillment of Bachelor of Science degree in Computer Science, April 2019The emergence of educational video games have changed the perspective of many on video games as only an entertainment tool. Video games have been beneficial in improving language skills, reading skills and cognitive abilities of children. The traditional method of teaching and learning history in the classroom has made history boring and unlikeable for students. Although, methods like films and museums attempt to engage the student, they do not fully immerse them. To create an immersive learning experience for students, video games can be used as a technological tool. This project describes a video game: Fireside, which attempts to create an immersive learning experience for students in junior high schools for learning history.Ashesi Universit

The Design and Use of a Smartphone Data Collection Tool and Accompanying Configuration Language

Understanding human behaviour is key to understanding the spread of epidemics, habit dispersion, and the efficacy of health interventions. Investigation into the patterns of and drivers for human behaviour has often been facilitated by paper tools such as surveys, journals, and diaries. These tools have drawbacks in that they can be forgotten, go unfilled, and depend on often unreliable human memories. Researcher-driven data collection mechanisms, such as interviews and direct observation, alleviate some of these problems while introducing others, such as bias and observer effects. In response to this, technological means such as special-purpose data collection hardware, wireless sensor networks, and apps for smart devices have been built to collect behavioural data. These technologies further reduce the problems experienced by more traditional behavioural research tools, but often experience problems of reliability, generality, extensibility, and ease of configuration. This document details the construction of a smartphone-based app designed to collect data on human behaviour such that the difficulties of traditional tools are alleviated while still addressing the problems faced by modern supplemental technology. I describe the app's main data collection engine and its construction, architecture, reliability, generality, and extensibility, as well as the programming language developed to configure it and its feature set. To demonstrate the utility of the tool and its configuration language, I describe how they have been used to collect data in the field. Specifically, eleven case studies are presented in which the tool's architecture, flexibility, generality, extensibility, modularity, and ease of configuration have been exploited to facilitate a variety of behavioural monitoring endeavours. I further explain how the engine performs data collection, the major abstractions it employs, how its design and the development techniques used ensure ongoing reliability, and how the engine and its configuration language could be extended in the future to facilitate a greater range of experiments that require behavioural data to be collected. Finally, features and modules of the engine's encompassing system, iEpi, are presented that have not otherwise been documented to give the reader an understanding of where the work fits into the larger data collection and processing endeavour that spawned it

Towards Interoperable Research Infrastructures for Environmental and Earth Sciences

This open access book summarises the latest developments on data management in the EU H2020 ENVRIplus project, which brought together more than 20 environmental and Earth science research infrastructures into a single community. It provides readers with a systematic overview of the common challenges faced by research infrastructures and how a ‘reference model guided’ engineering approach can be used to achieve greater interoperability among such infrastructures in the environmental and earth sciences. The 20 contributions in this book are structured in 5 parts on the design, development, deployment, operation and use of research infrastructures. Part one provides an overview of the state of the art of research infrastructure and relevant e-Infrastructure technologies, part two discusses the reference model guided engineering approach, the third part presents the software and tools developed for common data management challenges, the fourth part demonstrates the software via several use cases, and the last part discusses the sustainability and future directions

Languages of games and play: A systematic mapping study

Digital games are a powerful means for creating enticing, beautiful, educational, and often highly addictive interactive experiences that impact the lives of billions of players worldwide. We explore what informs the design and construction of good games to learn how to speed-up game development. In particular, we study to what extent languages, notations, patterns, and tools, can offer experts theoretical foundations, systematic techniques, and practical solutions they need to raise their productivity and improve the quality of games and play. Despite the growing number of publications on this topic there is currently no overview describing the state-of-the-art that relates research areas, goals, and applications. As a result, efforts and successes are often one-off, lessons learned go overlooked, language reuse remains minimal, and opportunities for collaboration and synergy are lost. We present a systematic map that identifies relevant publications and gives an overview of research areas and publication venues. In addition, we categorize research perspectives along common objectives, techniques, and approaches, illustrated by summaries of selected languages. Finally, we distill challenges and opportunities for future research and development

Domain-specific languages for modeling and simulation

Simulation models and simulation experiments are increasingly complex. One way to handle this complexity is developing software languages tailored to specific application domains, so-called domain-specific languages (DSLs). This thesis explores the potential of employing DSLs in modeling and simulation. We study different DSL design and implementation techniques and illustrate their benefits for expressing simulation models as well as simulation experiments with several examples.Simulationsmodelle und -experimente werden immer komplexer. Eine Möglichkeit, dieser Komplexität zu begegnen, ist, auf bestimmte Anwendungsgebiete spezialisierte Softwaresprachen, sogenannte domänenspezifische Sprachen (\emph{DSLs, domain-specific languages}), zu entwickeln. Die vorliegende Arbeit untersucht, wie DSLs in der Modellierung und Simulation eingesetzt werden können. Wir betrachten verschiedene Techniken für Entwicklung und Implementierung von DSLs und illustrieren ihren Nutzen für das Ausdrücken von Simulationsmodellen und -experimenten anhand einiger Beispiele

Towards Interoperable Research Infrastructures for Environmental and Earth Sciences

This open access book summarises the latest developments on data management in the EU H2020 ENVRIplus project, which brought together more than 20 environmental and Earth science research infrastructures into a single community. It provides readers with a systematic overview of the common challenges faced by research infrastructures and how a ‘reference model guided’ engineering approach can be used to achieve greater interoperability among such infrastructures in the environmental and earth sciences. The 20 contributions in this book are structured in 5 parts on the design, development, deployment, operation and use of research infrastructures. Part one provides an overview of the state of the art of research infrastructure and relevant e-Infrastructure technologies, part two discusses the reference model guided engineering approach, the third part presents the software and tools developed for common data management challenges, the fourth part demonstrates the software via several use cases, and the last part discusses the sustainability and future directions

Generic Roles: Reducing Code Replication

In partial fulfillment of requirements for the degree of Doctor of Philosophy in Informatics Enginnering by the Doctoral Program in Informatics EngineeringFor many years the concept of modularity has been considered a very important part in the development of large software systems. Modules help to manage the system’s complexity by decomposing it in smaller parts. These parts can be assigned to individuals or teams for development. Modules hide the information they manipulate behind an interface, allowing its developers to develop the module independently of any other module in the system. Developers can change the information their module manipulates and even the way it does it without the need to consult other developers, and breaking their code. This enables the interchangeability of modules, allowing one module to be substituted by another without further modifications to the system. It also reduces compiling time as modules can be precompiled. The concept of modularization lead to the dawn of several decompositions techniques, each with its own ideas on how a system should be decomposed into modules. For each decomposition technique and to help programmers extract the most benefits from modularization, several programming languages provide support for expressing modules. In object-oriented decomposition, for example, several programming languages provide support to define abstract data types, usually in the form of classes. Ideally, each module would capture one coherent concept that would deal with a set of coherent concerns related to the module’s concept. Unfortunately that is not always true. Sometimes, modules need to interact in more complicated and intertwined manners. Sometimes, the need to communicate with other modules lead one module to assume concerns that are not related to its main concern. This is, as argued by many authors, because only a single decomposition strategy is used . To avoid this we may need to use more than one decompositions strategy or extend an existing one. Code clones are an outcome of the lack of other decomposition strategies, among others sources. Code cloning in a system is considered a bad thing with multiple drawbacks. One of the more known problems is the inconsistent maintenance: bugs are fixed in some clones, but not in others. Another major objection to the use of cloning is that it degrades the design of the system over time. Awkward, verbose designs lead to the accumulation of irrelevant code that ends up obscuring the original intent of the code. In this dissertation we study the reduction of the code replication using modularity as a cornerstone around which our solution must be based. We intend to reduce code replication using another kind of module, which we can use to extend the object-oriented strategy. The module that we will study is the role. Roles have been used to specify na object’s behavior related to a specific collaboration in the modeling stages of a system. But in the implementation that specification is merged with all the object’s other collaboration behaviors, inside a class. It is a purpose of this dissertation to take the specification from the design phase to the implementation phase and study its impact on the code replication problem. The solution proposed in this dissertation is to use roles as a way to compose classes and thus reducing code replication. To pursue this goal a role language is designed and a suitable compiler is implemented. The JavaStage language allows a programmer to “program with roles”. It introduces several features like a powerful renaming mechanism and to state role dependencies easily. Using JavaStage and roles we were able to identify several refactorings that enables us to write the replicated code as roles thus removing the code clone. The use of these refactorings proved their value when applied to a series of case studies developed to assess the amount of duplicated code that could be removed using roles. As already mentioned, the modularity principles were followed throughout the design of the proposed solution and, to assess the reusability of roles, a role library was started. Its evolution corroborates the idea that roles are reusable modules and can be used as a compositional element.A modularidade é, já há muitos anos, vista como uma peça importante no desenvolvimento de sistemas informáticos de grandes dimensões. Os módulos ajudam a gerir a complexidade do sistema decompondo-o em várias partes mais pequenas que podem ser adjudicadas a um indivíduo ou a uma equipa para desenvolvimento. Os módulos encapsulam a informação que manipulam e o modo como a manipulam, permitindo assim aos seus autores desenvolvêlo independentemente dos outros módulos do sistema. Os autores de um módulo podem, inclusivé, alterar o modo de representação da informação à medida das suas necessidades, ou até alterar o modo de a manipular, sem consultar os autores dos outros módulos e sem quebrar os módulos destes. Isto permite a permutação de módulos, podendo assim um módulo ser substituído por outro sem que o sistema sofra outras alterações. Também permite um tempo de compilação mais rápido devido a poder-se pré-compilar os vários módulos. O conceito de modularização levou ao surgimento de várias estratégias de decomposição, cada uma com as suas ideias sobre como um sistema deveria ser decomposto em módulos. Para cada uma destas estragégias, e para ajudar os programadores a usufruir ao máximo dos benefícios da modularização, surgiram várias linguagens de programação com suporte para a representação de módulos. Por exemplo, na decomposição orientada a objetos, muitas linguagens permitem a definição de tipos abstratos de dados, normalmente na forma de classes. Idealmente, cada módulo capturaria um conceito coerente e esse conceito lidaria com um conjunto coerente de responsabilidades ligadas ao conceito principal do módulo. Infelizmente, não é assim. Por vezes os módulos precisam de interagir de forma mais complexa e interligada com outros módulos. Outras vezes a necessidade de comunicar com outros módulos leva-os a assumir responsabilidades que não estão de acordo com a sua “razão de ser”. Isto, como é argumentado por muitos autores, é uma consequência do uso de uma única estratégia de decomposição. Para evitar isto provavelmente necessita-se de uma outra forma de decomposição ou expandir uma já existente. O aparecimento de clones no código é uma consequência do uso de uma única estratégia de decomposição, entre outras causas. A presença de código repetido num sistema é considerada um mau indício e acarta muitas consequências nefastas. Um dos problemas mais conhecidos é a inconsistência na manutenção: os bugs são reparados em algumas instâncias do código repetido mas não em todas. Outro grande problema do uso de cópias de código é que o seu uso irá degradar o design do sistema a longo prazo. Isto leva à acumulação de código irrelevante que acaba por obscurecer o objectivo inicial do código. Nesta tese tenta-se estudar a redução de código repetido usando a modularidade como “pedra de toque” em torno da qual a nossa solução se baseará. Tencionámos reduzir a repetição de código usando outro tipo de módulo, que nos permita expandir a decomposição orientada a objetos. O módulo que iremos estudar será o role. Os roles têm vindo a ser usados para especificar o comportamento de um objeto em relação a outro objeto, dentro de uma colaboração, na etapa de modelação do sistema. Mas, na fase de implementação, essa especificação é agrupada com todos os comportamentos que o objeto exibe em todas as suas colaborações, dentro de uma classe. É um dos propósitos desta tese levar esta especificação desde a fase de modelação até à fase de implementação e estudar o seu impacto no problema de repetição de código. A solução proposta nesta dissertação é usar os roles como uma maneira de compor classes e assim reduzir a repetição de código. Para atingir este objectivo uma linguagem de programação que suporta roles será idealizada e um compilador adequado desenvolvido. A linguagem JavaStage permite a um programador “programar com roles”. Ela introduz algumas funcionalidades como um mecanismo de renomeação de métodos poderoso e uma forma de exprimir as dependências do role facilmente. Usando a JavaStage e os roles fomos capazes de identificar várias refactorings que nos permitem expressar o código presente nas várias repetições como roles e assim remover o código repetido associado. Estas refactorings mostraram o seu valor quando usadas numa série de casos de estudo que foram desenvolvidos com o propósito de avaliar a quantidade de código repetido que se poderia remover usando roles. Como já foi mencionado os princípios da modularidade foram seguidos ao longo da concepção da solução proposta e para avaliar a reutilização dos roles a construção de uma biblioteca de roles foi iniciada. A sua evolução corrobora a ideia de que os roles são módulos reutilizáveis e podem ser usados como um elemento composicional de classes