Responsive analytics are rapidly taking over the traditional data analytics dominated by the post-fact approaches in traditional data warehousing. Recent advancements in analytics demand placing analytical engines at the forefront of the system to react to updates occurring at high speed and detect patterns, trends and anomalies. These kinds of solutions find applications in Financial Systems, Industrial Control Systems, Business Intelligence and on-line Machine Learning among others. These applications are usually associated with Big Data and require the ability to react to constantly changing data in order to obtain timely insights and take proactive measures. Generally, these systems specify the analytical results or their basic elements in a query language, where the main task then is to maintain these results under frequent updates efficiently. The task of reacting to updates and analyzing changing data has been addressed in two ways in the literature: traditional business intelligence (BI) solutions focus on historical data analysis where the data is refreshed periodically and in batches, and stream processing solutions process streams of data from transient sources as flow (or set of flows) of data items. Both kinds of systems share the niche of reacting to updates (known as dynamic evaluation); however, they differ in architecture, query languages, and processing mechanisms. In this thesis, we investigate the possibility of a reactive and unified framework to model queries that appear in both kinds of systems. In traditional BI solutions, evaluating queries under updates has been studied under the umbrella of incremental evaluation of updates that is based on relational incremental view maintenance model and mostly focus on queries that feature equi-joins. Streaming systems, in contrast, generally follow the automaton based models to evaluate queries under updates, and they generally process queries that mostly feature comparisons of temporal attributes (e.g., timestamp attributes) along-with comparisons of non-temporal attributes over streams of bounded sizes. Temporal comparisons constitute inequality constraints, while non-temporal comparisons can either be equality or inequality constraints, hence these systems mostly process inequality joins. As starting point, we postulate the thesis that queries in streaming systems can also be evaluated efficiently based on the paradigm of incremental evaluation just like in BI systems in a main-memory model. The efficiency of such a model is measured in terms of runtime memory footprint and the update processing cost. To this end, the existing approaches of dynamic evaluation in both kind of systems present a trade-off between memory footprint and the update processing cost. More specifically, systems that avoid materialization of query (sub) results incur high update latency and systems that materialize (sub) results incur high memory footprint. We are interested in investigating the possibility to build a model that can address this trade-off. In particular, we overcome this trade-off by investigating the possibility of practical dynamic evaluation algorithm for queries that appear in both kinds of systems, and present a main-memory data representation that allows to enumerate query (sub) results without materialization and can be maintained efficiently under updates. We call this representation the Dynamic Constant Delay Linear Representation (DCLR). We devise DCLRs with the following properties: 1) they allow, without materialization, enumeration of query results with bounded-delay (and with constant delay for a sub-class of queries); 2) they allow tuple lookup in query results with logarithmic delay (and with constant delay for conjunctive queries with equi-joins only); 3) they take space linear in the size of the database; 4) they can be maintained efficiently under updates. We first study the DCLRs with the above-described properties for the class of acyclic conjunctive queries featuring equi-joins with projections and present the dynamic evaluation algorithm. Then, we present the generalization of thiw algorithm to the class of acyclic queries featuring multi-way theta-joins with projections. We devise DCLRs with the above properties for acyclic conjunctive queries, and the working of dynamic algorithms over DCLRs is based on a particular variant of join trees, called the Generalized Join Trees (GJTs) that guarantee the above-described properties of DCLRs. We define GJTs and present the algorithms to test a conjunctive query featuring theta-joins for acyclicity and to generate GJTs for such queries. To do this, we extend the classical GYO algorithm from testing a conjunctive query with equalities for acyclicity to test a conjunctive query featuring multi-way theta-joins with projections for acyclicity. We further extend the GYO algorithm to generate GJTs for queries that are acyclic. We implemented our algorithms in a query compiler that takes as input the SQL queries and generates Scala executable code – a trigger program to process queries and maintain under updates. We tested our approach against state of the art main-memory BI and CEP systems. Our evaluation results have shown that our DCLRs based approach is over an order of magnitude efficient than existing systems for both memory footprint and update processing cost. We have also shown that the enumeration of query results without materialization in DCLRs is comparable (and in some cases efficient) as compared to enumerating from materialized query results.

The understanding of what motivates a customer to pay more for a product or service has al-ways been a fundamental question in business. To the end of answering this question, revenue management is a business practice that revolves around using analytics to predict consumer behavior and willingness-to-pay. It has been a common practice within the commercial airline and hospitality industries for over 30 years, allowing adopters to reach their service capacity with increased profit margins. In this thesis, we investigated the possibility to apply revenue management to the last mile delivery industry, an industry that provides the service of delivering goods from e-commerce companies to the consumer’s front door. To achieve this objective, a revenue management framework was conceived, detailing the interaction between the customer and a dynamic pricing model. The model itself was a product of a machine learning model, intended to segment the customers and predict the willingness-to-pay of each customer segment. The performance of this model was tested through a quantitative study on synthetic buyers, subject to parameters that influence their willingness-to-pay. It was observed that the model was able to distinguish between different types of customers, yielding a pricing policy that increased profits by 7.5% in comparison to fixed price policies. It was concluded that several factors may impact the customer’s willingness-to-pay within the last mile delivery industry. Amongst these, the convenience that the service provides and the disparity between the price of the product and the price of the service were the most notable. However, the magnitude of considering these parameters was never determined. Finally, em-ploying dynamic pricing has the potential to increase the availability of the service, enabling a wider audience to afford the service. / Vad som motiverar en kund att betala mer för en tjänst eller en produkt har länge varit ett centralt koncept inom affärslivet. Intäktsoptimering är en affärspraxis som strävar efter att besvara den frågan, genom att med analytiska verktyg mäta och förutse betalningsviljan hos kunden. Intäktsoptimering har länge varit framträdande inom flyg- och hotellbranschen, där företag som anammat strategin har möjlighets att öka försäljningsvinsten. I detta examensarbete undersöker vi möjligheten att applicera intäktsoptimering på sista milen industrin, en industri som leverar köpta produkten hem till kunden. För att uppnå detta har vi tagit fram ett ramverk för informationsflöden inom intäktsoptimering som beskriver hur kunder interagerar med en dynamisk prissättningsmodell. Denna prissättningsmodell framställs genom maskininlärning med avsikt att segmentera kundbasen, för att sedan förutse betalningsviljan hos varje kundsegment. Modellens prestanda mättes genom en kvantitativ studie på syntetiska kunder som beskrivs av parametrar som påverkar betalningsviljan. Studien påvisade att modellen kunde skilja på betalningsviljan hos olika kunder och resulterade i en genomsnittlig vinstökning på 7.5% i jämförelse med statiska prissättningsmodeller. Det finns mänga olika faktorer som spelar in på kundens betalningsvilja inom sista milen industrin. Bekvämlighet och skillnader i priset på produkten som levereras och tjänsten att leverera produkten är två anmärkningsvärda faktorer. Hur stor inverkan faktorerna som beskrivs i detta examensarbete, har på betalningsviljan, förblev obesvarat. Slutligen uppmärksammades möjligheten att, med hjälp av dynamisk prissättning, öka tillgängligheten av tjänsten då flera kunder kan ha råd med en prissättning som överväger deras betalningsvilja.

Enforcing security policies to distributed systems is difficult, in particular, when a system contains untrusted components. We designed AspectKE*, a distributed AOP language based on a tuple space, to tackle this issue. In AspectKE*, aspects can enforce access control policies that depend on future behavior of running processes. One of the key language features is the predicates and functions that extract results of static program analysis, which are useful for defining security aspects that have to know about future behavior of a program. AspectKE* also provides a novel variable binding mechanism for pointcuts, so that pointcuts can uniformly specify join points based on both static and dynamic information about the program. Our implementation strategy performs fundamental static analysis at load-time, so as to retain runtime overheads minimal. We implemented a compiler for AspectKE*, and demonstrate usefulness of AspectKE* through a security aspect for a distributed chat system.