Liferay-teemaprojektien virtaviivaistaminen

Opinnäytteen tarkoituksena on tutkia, millä ohjelmistotuotannon keinoilla voidaan nopeuttaa ja yhdenmukaistaa Liferay 6.2 CE -portaalin teema-pluginien tuottamista asiakasprojekteihin. Teema-pluginit vastaavat portaaliympäristön ulkoasusta ja ovat tällöin osa miltei jokaista asiakastyönä tehtyä portaalitoimitusta. Opinnäytetyössä tutkittiin tapoja laajentaa Liferay-portaalin toiminnallisuutta hyödyntäen sen tarjoamia laajennuspisteitä. Jotta teema-plugineille saataisiin yrityksen sisällä yhtenäinen tuoterunko, tutkittiin myös yhdenmukaisten pohjaprojektien tuottamiseen soveltuvia menetelmiä yrityksen uusissa toteutusprojekteissa. Yhtenä tavoitteena oli tutkia, miten teema-plugineilla voitaisiin hyödyntää komponentteja eri toteutusprojektien välillä siten, että projekteissa usein toistuvia komponentteja voitaisiin yleistää ja käyttää tehokkaasti eri projektien välillä. Työn tuloksena syntyi prototyyppi Liferay-portaaliin upotettavasta moduulista, johon sisällytettiin teema-plugineille yleisesti hyödyllisiä toiminnallisuuksia. Tämän avulla poistettiin tarve upottaa samat toiminnallisuudet sisältävä Java-koodi kuhunkin teema-pluginiin, mikä oli tapana aikaisemmissa projekteissa. Teema-pluginien rakennukseen sekä uudelleenkäytettävien komponenttien käyttöönottoon kehitettiin sovellus Yeoman-alustalla.The goal of this thesis was to study different software development methods to achieve a faster and more efficient way to create theme plugins for the Liferay 6.2 CE platform. Theme plugins are mainly responsible for the look and feel of portal pages, and as such are an essential part of most projects. Different extension points available for extending the functionality of the platform were examined, so that common functionality earlier present in theme plugins themselves, could be unified so that they could be used by all theme plugins deployed in the same portal at runtime. This was achieved by comparing different ways of creating a plugin for the Liferay portal, and creating such a plugin to be used in future projects. One of the main goals outlined in the project was achieving component reuse between theme plugin projects. To address this, a Yeoman application was created for both creating boilerplate projects for starting new assignments, as well as acting as a library of reusable and/or boilerplate components

Applying Thompson Sampling to Online Hypothesis Testing

Online hypothesis testing occurs in many branches of science. Most notably it is of use when there are too many hypotheses to test with traditional multiple hypothesis testing or when the hypotheses are created one-by-one. When testing multiple hypotheses one-by-one, the order in which the hypotheses are tested often has great influence to the power of the procedure. In this thesis we investigate the applicability of reinforcement learning tools to solve the exploration – exploitation problem that often arises in online hypothesis testing. We show that a common reinforcement learning tool, Thompson sampling, can be used to gain a modest amount of power using a method for online hypothesis testing called alpha-investing. Finally we examine the size of this effect using both synthetic data and a practical case involving simulated data studying urban pollution. We found that, by choosing the order of tested hypothesis with Thompson sampling, the power of alpha investing is improved. The level of improvement depends on the assumptions that the experimenter is willing to make and their validity. In a practical situation the presented procedure rejected up to 6.8 percentage points more hypotheses than testing the hypotheses in a random order

Zero-Energy Modes from Coalescing Andreev States in a Two-Dimensional Semiconductor-Superconductor Hybrid Platform

We investigate zero-bias conductance peaks that arise from coalescing subgap Andreev states, consistent with emerging Majorana zero modes, in hybrid semiconductor-superconductor wires defined in a two-dimensional InAs/Al heterostructure using top-down lithography and gating. The measurements indicate a hard superconducting gap, ballistic tunneling contact, and in-plane critical fields up to $3$~T. Top-down lithography allows complex geometries, branched structures, and straightforward scaling to multicomponent devices compared to structures made from assembled nanowires.Comment: Includes Supplementary Materia

Applying machine learning to replicate large-eddy simulation results on urban pollutant dispersion

Non peer reviewe

Giant spin-orbit splitting in inverted InAs/GaSb double quantum wells

Transport measurements in inverted InAs/GaSb quantum wells reveal a giant spin-orbit splitting of the energy bands close to the hybridization gap. The splitting results from the interplay of electron-hole mixing and spin-orbit coupling, and can exceed the hybridization gap. We experimentally investigate the band splitting as a function of top gate voltage for both electron-like and hole-like states. Unlike conventional, noninverted two-dimensional electron gases, the Fermi energy in InAs/GaSb can cross a single spin-resolved band, resulting in full spin-orbit polarization. In the fully polarized regime we observe exotic transport phenomena such as quantum Hall plateaus evolving in $e^2/h$ steps and a non-trivial Berry phase

Scaling of Majorana Zero-Bias Conductance Peaks

We report an experimental study of the scaling of zero-bias conductance peaks compatible with Majorana zero modes as a function of magnetic field, tunnel coupling, and temperature in one-dimensional structures fabricated from an epitaxial semiconductor-superconductor heterostructure. Results are consistent with theory, including a peak conductance that is proportional to tunnel coupling, saturates at $2e^2/h$, decreases as expected with field-dependent gap, and collapses onto a simple scaling function in the dimensionless ratio of temperature and tunnel coupling.Comment: Accepted in Physical Review Letter

Decoupling Edge Versus Bulk Conductance in the Trivial Regime of an InAs/GaSb Double Quantum Well Using Corbino Ring Geometry

A Corbino ring geometry is utilized to analyze edge and bulk conductance of InAs/GaSb quantum well structures. We show that edge conductance exists in the trivial regime of this theoretically predicted topological system with a temperature-insensitive linear resistivity per unit length in the range of 2  kΩ/μm. A resistor network model of the device is developed to decouple the edge conductance from the bulk conductance, providing a quantitative technique to further investigate the nature of this trivial edge conductance, conclusively identified here as being of n type

Edge Transport in the Trivial Phase of InAs/GaSb

We present transport and scanning SQUID measurements on InAs/GaSb double quantum wells, a system predicted to be a two-dimensional topological insulator. Top and back gates allow independent control of density and band offset, allowing tuning from the trivial to the topological regime. In the trivial regime, bulk conductivity is quenched but transport persists along the edges, superficially resembling the predicted helical edge-channels in the topological regime. We characterize edge conduction in the trivial regime in a wide variety of sample geometries and measurement configurations, as a function of temperature, magnetic field, and edge length. Despite similarities to studies claiming measurements of helical edge channels, our characterization points to a non-topological origin for these observations