A Context-Aware and Preference-Driven Vacation Planner for Tourism Regions

Taking a Preference SQL approach, a context-aware vacation planner for on-site activities is proposed to automatically generate vacation plans based on user preferences and situational aspects. Using different levels of abstraction, the result of the corresponding preference queries is always optimal and the result size is minimal. It consists of stereotype-specific and contextaware activities which are combined to create daily or even multi-day plans of activities. The correctness, completeness and optimality are assured by a preference calculus of strict partial orders. User preferences are initially collected and defined by a feedback questionnaire. The application is modelled by adequate preference compositions and the Preference SQL runtime system efficiently evaluates the resulting preference queries. The prototype proves that soft runtime requirements are met. Initial tests with real data from the industry-leading outdooractive platform indicate that the database-driven preference technology can successfully be employed to provide added value for vacation planning

On Real-time Top k Querying for Mobile Services

Mobile services offering multi-feature query capabilities must meet tough response time requirements to gain customer acceptance. The top-k query model is a popular candidate to implement such services. Focusing on a central server architecture we present a new algorithm called SR-Combine that closely self-adapts itself to particular cost ratios in such environments. SR-Combine optimizes both the object accesses and the query run-times. We perform a series of synthetical benchmarks to verify the superiority of SR-Combine over existing algorithms. In order to assess whether it can meet the stated response time requirements for mobile access, we propose a psychologically founded model. It turns out that for a wide range of practical cases SR-Combine can satisfy these goals. Where this isn't yet the case, we show up ways how to get there systematically. Thus with SR-Combine a breakthrough in real-time capabilities of top-k querying for mobile services is in sight now

An XML-based Multimedia Middleware for Mobile Online Auctions

Pervasive Internet services today promise to provide users with a quick and convenient access to a variety of commercial applications. However, due to unsuitable architectures and poor performance user acceptance is still low. To be a major success mobile services have to provide device-adapted content and advanced value-added Web services. Innovative enabling technologies like XML and wireless communication may for the first time provide a facility to interact with online applications anytime anywhere. We present a prototype implementing an efficient multimedia middleware approach towards ubiquitous value-added services using an auction house as a sample application. Advanced multi-feature retrieval technologies are combined with enhanced content delivery to show the impact of modern enterprise information systems on today’s e-commerce applications

Witnessing, remembering and testifying: why the past is special for human beings

The past is undeniably special for human beings. To a large extent, both individuals and collectives define themselves through history. Moreover, humans seem to have a special way of cognitively representing the past: episodic memory. As opposed to other ways of representing knowledge, remembering the past in episodic memory brings with it the ability to become a witness. Episodic memory allows us to determine what of our knowledge about the past comes from our own experience and thereby what parts of the past we can give testimony about. In this article, we aim to give an account of the special status of the past by asking why humans have developed the ability to give testimony about it. We argue that the past is special for human beings because it is regularly, and often principally, the only thing that can determine present social realities like commitments, entitlements, and obligations. Since the social effects of the past often do not leave physical traces behind, remembering the past and the ability to bear testimony it brings, is necessary in order to coordinate social realities with other individuals

African Linguistics in Central and Eastern Europe, and in the Nordic Countries

Non peer reviewe

Preference constructors for deeply personalized database queries

Deep personalization of database queries requires a semantically rich, easy to handle and flexible preference model. Building on preferences as strict partial orders we provide a variety of intuitive and customizable base preference constructors for numerical and categorical data. For complex constructors we introduce the notion of "substitutable values" (SV-semantics). Preferences with SV-semantics solve major open problems with Pareto and prioritized preferences. Known laws from preference relational algebra remain valid under SV-semantics. These powerful modeling capabilities even contribute to improve efficient preference query evaluation. Moreover, for the first time we point out a semantic-guided way to cope with the infamous flooding effect of query engines. Performing a series of test queries on sample data from an e-procurement application, we provide evidence that the flooding problem comes under control for deeply personalized database queries