Programming plays a paramount role in many educational policies and initiatives. However, the current focus on coding skills poses a risk of giving pupils an over simplistic and impoverished idea of what programming means and involves. Their experiences would be much more significant if learning were aimed at understanding the richness of the nature of programs. In fact, programs are strange creatures that escape simple definitions. They are real, in that they affect our real lives; they are abstract, in that they process abstract entities; and they are concrete, in that they take up space in digital devices memory, and can be copied, transferred, corrupted. Thus, understanding the multifaceted nature of programs is crucial knowledge for all citizens of the digital era, and a fundamental component of such an understanding is getting a sense of how programs are created and work (i.e., the programming process). To the best of our knowledge, there is no Nature of Programs framework (e.g., a set of statements that describe what the nature of programs is), that teachers and policy makers can use to shape their practice and targets. The goal of the WG is developing such a framework, by collecting and organizing contributions from CER, CS experts, and educators.

Healthcare Systems are transforming from focusing on acute care to focusing on managing chronic conditions. In this process they are becoming highly distributed and specialized. Innovative approaches are needed to fully support the design and deployment of new eHealth interventions. Design should be based on theory and evidence, and deployment should be supported by a sustainable ICT platform, that enables interoperability and reusability by focusing on open standards, open data, open source technology and knowledge modeling. We tested one such method that focuses on using behavior change techniques for the design phase, and tested OpenEHR and BPMN2 as the basis for the ICT platform to support the deployment phase.

In the two-dimensional range minimum query problem an input matrix A of dimension m × n , m ≤ n , has to be preprocessed into a data structure such that given a query rectangle within the matrix, the position of a minimum element within the query range can be reported. We consider the space complexity of the encoding variant of the problem where queries have access to the constructed data structure but can not access the input matrix A , i.e. all information must be encoded in the data structure. Previously it was known how to solve the problem with space O ( mn min { m ,log n }) bits (and with constant query time), but the best lower bound was Ω( mn log m ) bits, i.e. leaving a gap between the upper and lower bounds for non-quadratic matrices. We show that this space lower bound is optimal by presenting an encoding scheme using O ( mn log m ) bits. We do not consider query time. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

We study the problem of automatic generation of smooth and obstacle-avoiding planar paths for efficient guidance of autonomous mining vehicles. Fast traversal of a path is of special interest. We consider fourwheel four-gear articulated vehicles and assume that we have an a priori knowledge of the mine wall environment in the form of polygonal chains. Computing quartic uniform B-spline curves, minimizing curvature variation, staying at least at a proposed safety margin distance from the mine walls, we plan high speed paths. We present a study where our implementations are successfully applied on eight path-planning cases arising from real-world mining data provided by the Swedish mining company Luossavaara-Kiirunavaara AB (LKAB). The results from the study indicate that our proposed methods for computing obstacle-avoiding minimum curvature variation B-splines yield paths that are substantially better than the ones used by LKAB today. Our simulations show that, with an average 32.13%, the new paths are faster to travel along than the paths currently in use. Preliminary results from the production at LKAB show an overall 5%-10% decrease in the total time for an entire mining cycle. Such a cycle includes both traveling, ore loading, and unloading.

Over the neat few years the public-switched telephone network (PSTN) will evolve into next-generation networks (NGN), in which data and voice will share a common packet-switched network. The NGN introduces new concepts and networking protocols for the 'everything over IP' strategy. The Softswitch, the media gateway and the signaling gateway are the basic elements of the current NGN architecture. In this paper we show that these elements do not meet the requirements of some SS7 ISUP supplementary services that are widely used in telecommunication networks. The major drawbacks of the current NGN implementations that are based on those services are investigated. To overcome these drawbacks we propose a new element in the NGN architecture, called multi-service mediator (MSM) and describe an interworking scenario with other currently defined NGN elements, especially with the Softswitch. We investigate requirements for controlling and management of MSM in NGN. Additionally we propose a building block for simulation of the NGN architecture, including MSM.

This paper presents a new set of forwarding behaviors that fits rate-adaptive and delay-sensitive applications with limited loss tolerance. We consider an application to have limited loss tolerance if it needs loss-free forwarding of specific packets up to a certain rate. The new set of forwarding behaviors are attractive for developing real-time applications for the Internet. In particular, such applications can be designed to use reserved forwarding capacity efficiently and compete for more bandwidth while being fair to best-effort traffic. To provide the new set of forwarding behaviors, we define a scheduling mechanism that can be implemented efficiently. Through simulations, we show that this mechanism supports the defined forwarding behaviors.

This paper deals with the problem of storing a subset of elements from the bounded universe $\mathcal{M} = \{0, \ldots, M-1\}$ so that membership queries can be performed efficiently. In particular, we introduce a data structure to represent a subset of N elements of $\mathcal{M}$ in a number of bits close to the information-theoretic minimum, $B = \left\lceil \lg {M\choose N} \right\rceil$, and use the structure to answer membership queries in constant time.

For some time, the networking community has assumed that it is impossible to do IP routing lookups in software fast enough to support gigabit speeds. IP routing lookups must find the routing entry with the longest matching prefix, a task that has been thought to require hardware support at lookup frequencies of millions per second.We present a forwarding table data structure designed for quick routing lookups. Forwarding tables are small enough to fit in the cache of a conventional general purpose processor. With the table in cache, a 200 MHz Pentium Pro or a 333 MHz Alpha 21164 can perform a few million lookups per second. This means that it is feasible to do a full routing lookup for each IP packet at gigabit speeds without special hardware.The forwarding tables are very small, a large routing table with 40,000 routing entries can be compacted to a forwarding table of 150-160 Kbytes. A lookup typically requires less than 100 instructions on an Alpha, using eight memory references accessing a total of 14 bytes.