Techn. Universiẗat, Diss., 2004--Darmstadt.

There are a number of known architectural patterns for TCP/IP server design. I present a survey of design choices based on some of the most common of these patterns. I have demonstrated, with working code samples, that most of these architectural patterns are readily portable between UNIX and Windows NT platforms without necessarily incurring significant performance penalties. / Computing / M. Sc. (Computer Science)

The emerging general purpose graphics processing units (GPGPU) computing has tremendously speeded up a great variety of commercial and scientific applications. The GPUs have become prevalent accelerators in current high performance clusters. Though the computational capacity per Watt of the GPUs is much higher than that of the CPUs, the hybrid GPU clusters still consume enormous power. To conserve energy on this kind of clusters is of critical significance. In this thesis, we seek energy conservative computing on the GPU accelerated servers. We introduce our studies as follows. First, we dissect the GPU memory hierarchy due to the fact that most of the GPU applications are suffering from the GPU memory bottleneck. We find that the conventional CPU cache models cannot be applied on the modern GPU caches, and the microbenchmarks to study the conventional CPU cache become invalid for the GPU. We propose the GPU-specified microbenchmarks to examine the GPU memory structures and properties. Our benchmark results verify that the design goal of the GPU has transformed from pure computation performance to better energy efficiency. Second, we investigate the impact of dynamic voltage and frequency scaling (DVFS), a successful energy management technique for CPUs, on the GPU platforms. Our experimental results suggest that GPU DVFS is still promising in conserving energy, but the patterns to save energy strongly differ from those of the CPU. Besides, the effect of GPU DVFS depends on the individual application characteristics. Third, we derive the GPU DVFS power and performance models from our experimental results, based on which we find the optimal GPU voltage and frequency setting to minimize the energy consumption of a single GPU task. We then study the problem of scheduling multiple tasks on a hybrid CPU-GPU cluster to minimize the total energy consumption by GPU DVFS. We design an effective offline scheduling algorithm which can reduce the energy consumption significantly. At last, we combine the GPU DVFS and dynamic resource sleep (DRS), another energy management technique, to further conserve the energy, for the online task scheduling on hybrid clusters. Though the idle energy consumption increases significantly compared to the offline problem, our online scheduling algorithm still achieves more than 30% of energy conservation with appropriate runtime GPU DVFS readjustments.

The purpose of this thesis is to develop software to stream input and output audio from a large number of computers in a network to one specific computer in the same network. This computer will save the audio to disk. The audio that is to be saved will consist mostly of spoken communication. The saved audio is to be used in a framework for modeling and visualization. There are three major problems involved in designing a software to fill this purpose: recording both input and output audio at the same time, efficiently receiving multiple audio-streams at once and designing an interface where finding and organizing the computers to record audio from is easy. The software developed to solve these problems consists of two parts; a server and a client. The server captures the input (microphone) and output (speaker) audio from a computer. To capture the output and input audio simultaneously an external application named Virtual Audio Cable (VAC) is used. The client connects to multiple servers and receives the captured audio. Each one of the client’s server-connections is handled by its own thread. To make it easy to find available servers an Automatic Server Discovery System has been developed. To simplify the organization of the servers they are displayed in a tree-view specifically designed for this purpose.

Denna rapport beskriver utvecklandet av en applikation till operativsystemet Android. Här sätts utvecklingen av applikationen i förhållande till god användbarhet och hantering av resurser på en mindre plattform. En server med tillhörande databas kommunicerar med applikationen som klient. De båda utgör tillsammans helheten i ett system designat för bokningsbolaget Current and Able, verksamt i Sverige, som önskar presentera sitt utbud av exklusiva varor och tjänster direkt till fans av bolagets artister.   I projektet avhandlas grundläggande klasser och komponenter för utveckling av applikationer till Android och hur de bäst samverkar för att optimera användandet av resurser. Java användes huvudsakligen som programmeringsspråk. På serversidan utvecklades ett gränssnitt i PHP mot en MySQL databashanterare. / This study describes the development of an application for the operating system Android. We consider the developing of the application in relation to a good user experience and the managing of resources on a smaller device. A server with an appurtenant database communicates with the application as a client. Together they constitute a unity in a system designed to serve Current and Able, a managing and booking music agency in Sweden, who whishes to offer their supply of goods and services to the fans of their related artists.   In this project we deal with basic classes and components regarding development of Android applications and how they interact to achieve the best possible performance when using system resources. Java was the main programming language used. On the server side we developed a graphical user interface in PHP, targeting a MySQL database management system.

No description available.

Magister Scientiae - MSc / Stress responsive genes play a key role in shaping the manner in which plants process and respond to environmental stress. Their gene products are linked to DNA transcription and its consequent translation into a response product. However, whilst these genes play a significant role in manufacturing responses to stressful stimuli, transcription factors coordinate access to these genes, specifically by accessing a gene's promoter region which houses transcription factor binding sites. Here transcriptional elements play a key role in mediating responses to environmental stress where each transcription factor binding site may constitute a potential response to a stress signal. Arabidopsis thaliana, a model organism, can be used to identify the mechanism of how transcription factors shape a plant's survival in a stressful environment. Whilst there are numerous plant stress research groups, globally there is a shortage of publicly available stress responsive gene databases. In addition a number of previous databases such as the Generation Challenge Programme's comparative plant stressresponsive gene catalogue, Stresslink and DRASTIC have become defunct whilst others have stagnated. There is currently a single Arabidopsis thaliana stress response database called STIFDB which was launched in 2008 and only covers abiotic stresses as handled by major abiotic stress responsive transcription factor families. Its data was sourced from microarray expression databases, contains numerous omissions as well as numerous erroneous entries and has not been updated since its inception.The Dragon Arabidopsis Stress Transcription Factor database (DASTF) was developed in response to the current lack of stress response gene resources. A total of 2333 entries were downloaded from SWISSPROT, manually curated and imported into DASTF. The entries represent 424 transcription factor families. Each entry has a corresponding SWISSPROT, ENTREZ GENBANK and TAIR accession number. The 5' untranslated regions (UTR) of 417 families were scanned against TRANSFAC's binding site catalogue to identify binding sites. The relational database consists of two tables, namely a transcription factor table and a transcription factor family table called DASTF_TF and TF_Family respectively. Using a two-tier client-server architecture, a webserver was built with PHP, APACHE and MYSQL and the data was loaded into these tables with a PYTHON script. The DASTF database contains 60 entries which correspond to biotic stress and 167 correspond to abiotic stress while 2106 respond to biotic and/or abiotic stress. Users can search the database using text, family, chromosome and stress type search options. Online tools have been integrated into the DASTF, database, such as HMMER, CLUSTALW, BLAST and HYDROCALCULATOR. User's can upload sequences to identify which transcription factor family their sequences belong to by using HMMER. The website can be accessed at http://apps.sanbi.ac.za/dastf/ and two updates per year are envisaged. / South Africa

No description available.

This thesis is dedicated to security of client-server applications running on Windows platform. In the beginning chapters it is possible to find motivation, about why this type of security is important. Following content describes some elements of used architecture and elements of operating system Windows. The core of the work contains techniques and tools used by the attacker and protection against them. In following chapter there is a design and implementation of the security solution based on the previous theory. This solution is then tested against various threats, to verify its effectivity.

Ziel der Arbeit war es, eine Client-Server-basierte Loesung zu entwickeln, welche eine Backupfunktionalitaet in einer heterogenen Workstationumgebung mit dezentralen Filesystemen bereitstellt. Das System sollte mit Hilfe einer Scriptsprache implemetiert werden, um die Systemunabhaengigkeit der Komponenten zu gewaehrleisten. Zu diesem Zwecke wurde als Grundlage das ¨Remote Scripting Environment¨, welches Gegenstand der Diplomarbeit von Andre Glaesz am Lehrstuhl Betriebssysteme war, gewaehlt.