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Full-Text Articles in Computer Engineering

Un-Fair Trojan: Targeted Backdoor Attacks Against Model Fairness, Nicholas Furth May 2022

Un-Fair Trojan: Targeted Backdoor Attacks Against Model Fairness, Nicholas Furth

Theses

Machine learning models have been shown to be vulnerable against various backdoor and data poisoning attacks that adversely affect model behavior. Additionally, these attacks have been shown to make unfair predictions with respect to certain protected features. In federated learning, multiple local models contribute to a single global model communicating only using local gradients, the issue of attacks become more prevalent and complex. Previously published works revolve around solving these issues both individually and jointly. However, there has been little study on the effects of attacks against model fairness. Demonstrated in this work, a flexible attack, which we call Un-Fair …


Design And Implementation Of Photovoltaic Energy Harvesting Automaton, Iskandar Askarov Jan 2022

Design And Implementation Of Photovoltaic Energy Harvesting Automaton, Iskandar Askarov

Theses

Global domestic electricity consumption has been rapidly increasing in the past three decades. In fact, from 1990 to 2020, consumption has more than doubled from 10,120 TWh to 23,177 TWh [1]. Moreover, consumers have been turning more towards clean, renewable energy sources such as Photovoltaic. According to International Energy Agency, global Solar power generation alone in 2019 has reached almost 3% [4] of the electricity supply. Even though the efficiency of photovoltaic panels has been growing, presently, the highest efficiency solar panels available to an average consumer range only from 20%-22% [14]. Many research papers have been published to increase …


Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware, Yuvraj Dineshkumar Patel Dec 2020

Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware, Yuvraj Dineshkumar Patel

Theses

The scalability and power efficiency of the conventional CMOS technology is steadily coming to a halt due to increasing problems and challenges in fabrication technology. Many non-volatile memory devices have emerged recently to meet the scaling challenges. Memory devices such as RRAMs or ReRAM (Resistive Random-Access Memory) have proved to be a promising candidate for analog in memory computing applications related to inference and learning in artificial intelligence. A RRAM cell has a MIM (Metal insulator metal) structure that exhibits reversible resistive switching on application of positive or negative voltage. But detailed studies on the power consumption, repeatability and retention …


Semiconductor Materials And Devices For 2 Micron Generation, Dzianis Saladukha Jan 2017

Semiconductor Materials And Devices For 2 Micron Generation, Dzianis Saladukha

Theses

In the last century, semiconductor research has led to significant changes in the fields of communication, medicine, the environment, and many others. Semiconductor devices provide a relatively simple and effective way to convert electrical energy to light and vice versa. Devices based on semiconductor materials of various kinds provide interaction of an electromagnetic signal in the range of wavelengths with a medium. Examples of such devices are LED lamps, photovoltaic cells, thermometers, gas sensors, cameras, and many others. The study of various semiconductors broadens the range of application of photonics. This work is based on the study of materials which …


Segmentation And Model Generation For Large-Scale Cyber Attacks, Steven E. Strapp Aug 2013

Segmentation And Model Generation For Large-Scale Cyber Attacks, Steven E. Strapp

Theses

Raw Cyber attack traffic can present more questions than answers to security analysts. Especially with large-scale observables it is difficult to identify which packets are relevant and what attack behaviors are present. Many existing works in Host or Flow Clustering attempt to group similar behaviors to expedite analysis; these works often phrase the problem directly as offline unsupervised machine learning. This work proposes online processing to simultaneously model coordinating actors and segment traffic that is relevant to a target of interest, all while it is being received. The goal is not just to aggregate similar attack behaviors, but to provide …


Semi-Automatic Management Of Knowledge Bases Using Formal Ontologies, Andreas Textor Jan 2011

Semi-Automatic Management Of Knowledge Bases Using Formal Ontologies, Andreas Textor

Theses

This thesis presents an approach that deals with the ever-growing amount of data in knowledge bases, especially concerning knowledge interoperability and formal representation of domain knowledge. There arc multiple issues that must be addressed with current systems. A multitude of different formats, sources and tools exist in a domain, and it is desirable to develop their use further towards a standardised environment. Such an environment should support both the representation and processing of data from this domain, and the connection to other domains, where necessary. In order to manage large amounts of data, it should be possible to perform whatever …


Optimization In Multi-Agent Systems : Structures And Procedures, Ingo Stengel Jan 2008

Optimization In Multi-Agent Systems : Structures And Procedures, Ingo Stengel

Theses

The main advantage for the use of agent technology is in the capacity of agents to represent the interests of individual entities and to act autonomously on their behalf. In multi-agent systems this involves communication, coordination and negotiation.

The focus of this dissertation is to find ways to optimize multi-agent systems at different levels by taking into consideration their structure and the procedures used. As optimization depends to a large extent on the problem to be solved, group forming scenarios, in which self-interested agents compete to form and join groups, have been selected here for consideration. Optimization issues are discussed …


Personal Information Management. A Framework For Development Of Personalisable Web Based Services, Christopher Fuchs Jan 2007

Personal Information Management. A Framework For Development Of Personalisable Web Based Services, Christopher Fuchs

Theses

The thesis research proposed herein will model, analyse and implement strategies for the development of personalised services. The goal of the research work is to design and implement a framework which supports developers by minimising the effort required in implementing personalised services. This includes the ability to react to localisation changes and to present proper information. An overall design goal is the independency of most components from each other which will be attained through the use of standard technologies and protocols and the consistent use of a component model. The result will include the proposed framework and the analyses of …


Design And Implementation Of An Intranet-Solution Especially With Workflow Aspects, Robert Loew Jan 2001

Design And Implementation Of An Intranet-Solution Especially With Workflow Aspects, Robert Loew

Theses

An Intranet support a new or simply an easier information system for all the workers within a company using internet technology. On the one hand, employees can use Web technology and very simple tools to provide and navigate information. On the other hand, the costly and time-consuming business of installing and maintaining software on local PCs can be avoided by using Browser-based Intranet applications. Ideally, it would be possible to access all forms of information processing using one and the same Web browser. This is the aim of the Intranet Project upon which this thesis is based.

Various technologies for …


Security In Distributed Systems - A Framework For Different Application Types, Ingo Stengel Jan 2000

Security In Distributed Systems - A Framework For Different Application Types, Ingo Stengel

Theses

Security is a factor which decides upon the applicability of distributed applications. Therefore this thesis deals with security in distributed systems. The complexity of the existing distributed technologies makes it necessary to reduce the number of distributed technologies considered in this thesis, i.e. concentrating on: Java, Mobile Agents and CORBA, where only Java-based mobile agents will be considered.

After a short review of basic security principles including firewalls, existing security problems in the above mentioned distributed technologies are analysed. Additional generic problems in distributed systems are outlined.

Solutions are referring to two different areas: those regarding security problems with firewalls …


Enterprise Business Objects : Design And Implementation Of A Business Object Framework, Kai-Uwe Schafer Jan 1999

Enterprise Business Objects : Design And Implementation Of A Business Object Framework, Kai-Uwe Schafer

Theses

Software components representing business entities like customer or purchase order introduce a new way of Online Transaction Processing to business applications. Collaborating business objects allow to complete whole business processes as a single distributed transaction, instead of dividing it into queued steps, which sometimes even require user intervention. This IS due to the fact that business objects contain both business data and logic and that they incorporate multiple databases from different vendors and different geographic locations in a single transaction.

Business objects cannot be used as stand-alone components, but require a framework of services that manage persistence, concurrent transactions, and …