Przemyslaw Lenkiewicz

Large multimedia archive for world languages

In this paper, we describe the core pillars of a large archive of language material recorded worldwide partly about languages that are highly endangered. The bases for the documentation of these languages are audio/video recordings which are then annotated at several linguistic layers. The digital age completely changed the requirements of long-term preservation and it is discussed how the archive met these new challenges. An extensive solution for data replication has been worked out to guarantee bit-stream preservation. Due to an immediate conversion of the incoming data to standards-based formats and checks at upload time lifecycle management of all 50 Terabyte of data is widely simplified. A suitable metadata framework not only allowing users to describe and discover resources, but also allowing them to organize their resources is enabling the management of this amount of resources very efficiently. Finally, it is the Language Archiving Technology software suite which allows users to create, manipulate, access and enrich all archived resources given that they have access permissions.

Issues on performance assessment of optical burst switched networks: burst loss versus packet loss metrics

With the increasing interest in optical burst switching (OBS) networks, the performance assessment of this kind of networks became of particular concern. Recently, some authors suggested that burst loss was not a reliable performance assessment metric for OBS networks. Refuting this claim, this paper presents simulation results obtained for a ring network, using real tributary IPv4 packets as source for the burst assembly. It is shown that burst loss, packet loss and byte loss lead to similar results over a wide range of burst assembly scenarios and network loads, using different resource reservation schemes. Therefore, burst loss is a reliable metric and can be used for evaluation of performance of optical burst switched networks, when realistic burst assembly algorithms are considered over real traffic.

The whole mesh deformation model: a fast image segmentation method suitable for effective parallelization

In this article, we propose a novel image segmentation method called the whole mesh deformation (WMD) model, which aims at addressing the problems of modern medical imaging. Such problems have raised from the combination of several factors: (1) significant growth of medical image volumes sizes due to increasing capabilities of medical acquisition devices; (2) the will to increase the complexity of image processing algorithms in order to explore new functionality; (3) change in processor development and turn towards multi processing units instead of growing bus speeds and the number of operations per second of a single processing unit. Our solution is based on the concept of deformable models and is characterized by a very effective and precise segmentation capability. The proposed WMD model uses a volumetric mesh instead of a contour or a surface to represent the segmented shapes of interest, which allows exploiting more information in the image and obtaining results in shorter times, independently of image contents. The model also offers a good ability for topology changes and allows effective parallelization of workflow, which makes it a very good choice for large datasets. We present a precise model description, followed by experiments on artificial images and real medical data.

Application of audio and video processing methods for language research and documentation: The AVATecH Project

Evolution and changes of all modern languages is a well-known fact. However, recently it is reaching dynamics never seen before, which results in loss of the vast amount of information encoded in every language. In order to preserve such rich heritage, and to carry out linguistic research, properly annotated recordings of world languages are necessary. Since creating those annotations is a very laborious task, reaching times 100 longer than the length of the annotated media, innovative video processing algorithms are needed, in order to improve the efficiency and quality of annotation process. This is the scope of the AVATecH project presented in this article.