A Study on the Open Source Digital Library Software's: Special Reference to DSpace, EPrints and Greenstone

The richness in knowledge has changed access methods for all stake holders in retrieving key knowledge and relevant information. This paper presents a study of three open source digital library management software used to assimilate and disseminate information to world audience. The methodology followed involves online survey and study of related software documentation and associated technical manuals.Comment: 9 Pages, 3 Figures, 1 Table, "Published with International Journal of Computer Applications (IJCA)

Performance of Size-Changing Algorithms in Stackable File Systems

Stackable file systems can provide extensible file system functionality with minimal performance overhead and development cost. However, previous approaches are limited in the functionality they provide. In particular, they do not support size-changing algorithms, which are important and useful for many applications, such as compression and security. We propose fast index files, a technique for efficient support of size-changing algorithms in stackable file systems. Fast index files provide a page mapping between file system layers in a way that can be used with any size-changing algorithm. Index files are designed to be recoverable if lost and add less than 0.1\% disk space overhead. We have implemented fast indexing using portable stackable templates, and we have used this system to build several example file systems with size-changing algorithms. We demonstrate that fast index files have very low overhead for typical workloads, only 2.3\% over other stacked file systems. Our system can deliver much better performance on size-changing algorithms than user-level applications, as much as five times faster

A framework for multimedia playback and analysis of MPEG-2 videos with FFmpeg

Fast Forward Motion Pictures Expert Group (FFmpeg) is a well-known, high performance, cross platform open source library for recording, streaming, and playback of video and audio in various formats, namely, Motion Pictures Expert Group (MPEG), H.264, Audio Video Interleave (AVI), just to name a few. With FFmpeg current licensing options, it is also suitable for both open source and commercial software development. FFmpeg contains over 100 open source codecs for video encoding and decoding. Given the complexities of MPEG standards, FFmpeg still lacks a framework for (1) seeking to a particular image frame in a video, which is needed for accurate annotation at the frame level for applications in fields such as medical domain, digital communications and commercial video broadcasting and (2) motion vectors extraction for analysis of motion patterns in video content. Most importantly, FFmpeg code base is not well documented, which has raised a significant difficulty for developing an extension. As our contributions, we extended FFmpeg code base to include new APIs and libraries support accurate frame-level seek, motion vector extraction, and MPEG-2 video encoding/decoding. We documented FFmpeg MPEG-2 codec to facilitate future software development. We evaluated the performance of our implementation against a high-performance third-party commercial software development kit on videos captured from television broadcasts and from endoscopy procedures. To evaluate the usability of our libraries, we integrated them with some commercial applications. In the following sections, we will discuss our software architecture, important implementation details, performance evaluation results, and lessons learned

Enhancing a Neurosurgical Imaging System with a PC-based Video Processing Solution

This work presents a PC-based prototype video processing application developed to be used with a specific neurosurgical imaging device, the OPMI® PenteroTM operating microscope, in the Department of Neurosurgery of Helsinki University Central Hospital at Töölö, Helsinki. The motivation for implementing the software was the lack of some clinically important features in the imaging system provided by the microscope. The imaging system is used as an online diagnostic aid during surgery. The microscope has two internal video cameras; one for regular white light imaging and one for near-infrared fluorescence imaging, used for indocyanine green videoangiography. The footage of the microscope’s current imaging mode is accessed via the composite auxiliary output of the device. The microscope also has an external high resolution white light video camera, accessed via a composite output of a separate video hub. The PC was chosen as the video processing platform for its unparalleled combination of prototyping and high-throughput video processing capabilities. A thorough analysis of the platform and efficient video processing methods was conducted in the thesis and the results were used in the design of the imaging station. The features found feasible during the project were incorporated into a video processing application running on a GNU/Linux distribution Ubuntu. The clinical usefulness of the implemented features was ensured beforehand by consulting the neurosurgeons using the original system. The most significant shortcomings of the original imaging system were mended in this work. The key features of the developed application include: live streaming, simultaneous streaming and recording, and playing back of upto two video streams. The playback mode provides full media player controls, with a frame-by-frame precision rewinding, in an intuitive and responsive interface. A single view and a side-by-side comparison mode are provided for the streams. The former gives more detail, while the latter can be used, for example, for before-after and anatomic-angiographic comparisons.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Remote Control of Unmanned Aerial Vehicles Through the Internet and IEEE 802.11

This dissertation focuses on real-time control of Unmanned Aerial Vehicles (UAVs) through TCP/IP/IEEE 802.11. Using the MAVLink protocol - an open-source protocol for micro air vehicles - a solution that allows the exchange, in real-time, of control messages between a UAV and a remote Control Station was implemented. In order to allow the UAV control by a remote user, the vehicle streams a real-time video feed captured by a video-camera on board. The main challenge of this dissertation is related about the designing and implementation of a fast handover solution that allows an uninterruptible communication

QLOOP: Linux driver to mount QCOW2 virtual disks

Development of a Linux module that converts a QCOW2 file (a disk image format employed by QEMU and KVM projects) into a block device