SINGLE-ROW ROUTING PROBLEM WITH ALTERNATIVE TERMINALS

The present article concentrates on the dogleg-free Manhattan model where horizontal and vertical wire segments are positioned on different sides of the board and each net (wire) has at most one horizontal segment. Gallai's classical result on interval packing can be applied in VLS1 routing to find, in linear time, a minimum-width dogleg-free routing in the Manhattan model, provided that all the terminals are on one side of a rectangular (single-row routing). We deal with the generalization of this routing problem when we have the possibility to select another terminal from a corresponding set instead of a terminal to be connected. It will be shown that in this case there is no hope to find a polynomial algorithm because this problem is NP-complete. The results on dogleg-free Manhattan routing can be connected with other application areas related to colouring of interval graphs. In this paper the alternative interval placement problem will be defined. We show that this problem is NP-complete. This implies the NP-completeness of the single-row routing problem with alternative terminals

OPTIMAL ROUTING ON NARROW CHANNELS

Channel routing is one of the basic problems in VLSI routing. While the minimum width can be found in linear time in the single row routing problem, the complexity of the channel routing problem is not fully understood yet. A solution can be found, even in linear time, in the unconstrained model, but the complexity of determining the minimum width is not known. The present article concentrates on the Manhattan model where horizontal and vertical wire segments are positioned on different sides of the board. In this case, the routing problem is known to be NP-complete. Hence there is no hope to find an algorithm whose running time is polynomial both in the length and the width of the channel. The width of the channel is usually much smaller than the length, thus, an algorithm, whose running time is exponential in the width and polynomial' in the length can be efficient in the case of a narrow channel. We show that the channel routing problem in the Manhattan model is solvable in linear time if the length of the input is proportional to the length of the channel, and the width does not belong to the input

ROUTING WITH MINIMUM WIRE LENGTH IN THE MANHATTAN MODEL IS NP-COMPLETE

The present paper concentrates on one of the most common routing models, on the Manhattan model where horizontal and vertical wire segments are positioned on different sides of the board. While the minimum width can be found in linear time in the single row routing, apparently there was no efficient algorithm to find the minimum wire length. We showed before that this problem is NP-complete in the dogleg-free case but the complexity of the problem was still unknown in the general case. In this paper we modify the construction applied in the former proof in order to show the NP-completeness of routing with minimum wire length in the Manhattan model without any restrictions

Convergence and monotonicity of the hormone levels in a hormone-based content delivery system

The practical significance of bio-inspired, self-organising methods is rapidly increasing due to their robustness, adaptability and capability of handling complex tasks in a dynamically changing environment. Our aim is to examine an artificial hormone system that was introduced in order to deliver multimedia content in dynamic networks. The artificial hormone algorithm proved to be an efficient approach to solve the problem during the experimental evaluations. In this paper we focus on the theoretical foundation of its goodness. We show that the hormone levels converge to a limit at each node in the typical cases. We form a series of theorems on convergence with different conditions which are built on each other by starting with a specific base case and then we consider more general, practically relevant cases. The theorems are proved by exploiting the analogy between the Markov chains and the artificial hormone system. We examine spatial and temporal monotonicity of the hormone levels as well and give sufficient conditions on monotonic increase

Analysis of an Artificial Hormone System

The increased complexity of modern networks and the increasingly dynamic access patterns in multimedia consumption have led to new challenges for content delivery. Dynamic networks and dynamic access patterns result in a complex system. To deliver content efficiently we introduced an artificial hormone system that is capable of handling the dynamics, is self-organizing, robust and adaptive. The content placement problem is NP complete and is closely related to several hard problems including edge-disjoint path routing, scheduling and the bin packing problem. The evaluation of self-organizing algorithms brings also a real challenge. For a first evaluation we created and ILP model of the problem. It is applied to get the exact optimum that serves as a bound in the evaluation of the solution algorithms. In this paper, we examine the convergence of the algorithm and found that the hormone levels converge to a limit at each node in the typical cases. We form a series of theorems on convergence with different conditions by starting with a specific base case and then we consider more general, practically relevant cases. The theorems can be proved by exploiting the analogy between the Markov chains and the artificial hormone system

MTA SZTAKI SSS Multiplatform Technology 2.0 Előadások, konferencia anyagok archiválása, videók és prezentációk szerkesztése, szinkronizált lejátszása

Az MTA SZTAKI eLearning Osztály által kidolgozott SSS többplatformú technológia segítségével előadásokat és konferencia anyagokat archiválhatunk a hozzájuk tartozó illusztrációkkal (pl. előadás diákkal, animációkkal, videókkal) együtt. Az archivált előadást a felhasználók később bármikor megtekinthetik akár több platformon is (web és mobil), miközben az előadáshoz tartozó multimédia anyagok az előadás menetéhez igazítottan ütemezve jelennek meg. Az MTA SZTAKI SSS rendszere alkalmas eLearning szabványnak megfelelő multimédiacsomagok létrehozására és lejátszására. A legújabb fejlesztéseink eredményeként az SSS lejátszót a SCORM szabvány felhasználásával alkalmassá tettük kétirányú kommunikációra forráskódú eLearning keretrendszerekkel (pl.: Ilias, Moodle). Emiatt a rendszer különösen előnyös lehet olyan oktatási intézmények számára, akik a meglevő elektronikus oktatási keretrendszerükbe szeretnék beilleszteni a tantermi előadások rögzített videóit. Az előadásunkban az SSS technológiát meghatározott szempontok szerint összehasonlítjuk néhány létező hazai és külföldi, ill. akadémiai és kereskedelmi termékkel, hogy áttekintést adjunk a már létező termékekről, és megkönnyítsük a köztük való eligazodást

Mobile Access to Specimens of Bulgarian Iconography Through QR Code in a GPS-Based Information System

This paper presents an application of QR code marking of digi tal iconographical collections from the Bulgarian Iconographical Digital Library (BIDL) for their outdoor mobile access and exploring through the GUIDE@HAND audio tourist guide

BOOK@HAND BIDL: Mobile Exploring of the Bulgarian Iconography by Using Panorama Pictures

. The paper presents the newest developments in integrating Bulgarian Iconographical Digital Library (BIDL) and the tourist mobile application family named as (GUIDE@HAND). The integration made it possible that collections can be created by the user at the BIDL Web page and then they can be downloaded to the GUIDE@HAND Veliko Tarnovo application by using QR codes. This year, a new standalone offline mobile application (BOOK@HAND) was created providing information on icons available in BIDL where the collection presentation functionality of the former system was enhanced with new features. The main novelty of the application is the option to present collections in a virtual exhibition room by using panorama pictures in off-line mode