Computer Engineering Commons^™

Amorphous Core Transformers Efficiency Analysis In Turkish Electrical Distribution Systems, Fati̇h Işik, Yilmaz Uyaroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Transformers are an indispensable element in the transmission and distribution of electricity. While they are highly efficient, the increasing global demand for electrical energy has prompted efforts to improve their performance. No-load power losses constitute the majority of total losses within electrical energy distribution, especially when looking at load ratio. In recent years, some studies have found that no-load power losses of amorphous core transformers are less than those of laminated steel core transformers by as much as 60{\%} to 70{\%}. For this paper, we have manufactured an amorphous distribution transformer prototype rated 33 kV and 1 MVA. By quantifying …

Energy Economy In Regulated And Market-Based Power System: Case Study In Serbia, Mileta Zarkovic, Ivan Skokljev

Turkish Journal of Electrical Engineering and Computer Sciences

This study presents a possible process of simulating power plant generation planning. The process combines expected overall industry costs, associated cost uncertainty, and expected CO$_{2}$ emissions for different generations, variations of future fossil fuel costs, carbon prices, plant investment costs, and demand, including price elasticity impacts. Uncertainty in the decision stems from the elasticity of prices of fuel and electricity. The aim of this paper is to apply fuzzy numbers to power generation planning and to use a Monte Carlo simulation to check. Simulations are demonstrated through a case study of an electricity industry with coal and lignite, combined cycle …

Design, Application, And Power Performance Analyses Of A Micro Wind Turbine, Hayati̇ Mamur

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, design, implementation, and power performance analyses of a micro wind turbine (MWT) system are presented. An original permanent magnet synchronous generator (PMSG) that reduced cogging torque was employed as a generator in the MWT. A novel blade form offering better performance at low wind speeds was also utilized for the MWT blades. Power performance analyses of the MWT were carried out for different wind regimes by truck testing. Performance coefficient, cut-in, and cut-out of the MWT were determined as 27.7{\%}, 2.7 m/s, and 20 m/s at the end of the truck testing, respectively. Moreover, a new supervisory …

Positive Fragments Of Coalgebraic Logics, Adriana Balan, Alexander Kurz, Jirí Velebil

Engineering Faculty Articles and Research

Positive modal logic was introduced in an influential 1995 paper of Dunn as the positive fragment of standard modal logic. His completeness result consists of an axiomatization that derives all modal formulas that are valid on all Kripke frames and are built only from atomic propositions, conjunction, disjunction, box and diamond. In this paper, we provide a coalgebraic analysis of this theorem, which not only gives a conceptual proof based on duality theory, but also generalizes Dunn's result from Kripke frames to coalgebras for weak-pullback preserving functors. To facilitate this analysis we prove a number of category theoretic results on …

Presenting Distributive Laws, Marcello M. Bonsangue, Helle H. Hansen, Alexander Kurz, Jurriaan Rot

Engineering Faculty Articles and Research

Distributive laws of a monad T over a functor F are categorical tools for specifying algebra-coalgebra interaction. They proved to be important for solving systems of corecursive equations, for the specification of well-behaved structural operational semantics and, more recently, also for enhancements of the bisimulation proof method. If T is a free monad, then such distributive laws correspond to simple natural transformations. However, when T is not free it can be rather difficult to prove the defining axioms of a distributive law. In this paper we describe how to obtain a distributive law for a monad with an equational presentation …

Extensions Of Functors From Set To V-Cat, Adriana Balan, Alexander Kurz, Jirí Velebil

Engineering Faculty Articles and Research

We show that for a commutative quantale V every functor Set --> V-cat has an enriched left- Kan extension. As a consequence, coalgebras over Set are subsumed by coalgebras over V-cat. Moreover, one can build functors on V-cat by equipping Set-functors with a metric.

Approximation Of Nested Fixpoints, Alexander Kurz

Engineering Faculty Articles and Research

The question addressed in this paper is how to correctly approximate infinite data given by systems of simultaneous corecursive definitions. We devise a categorical framework for reasoning about regular datatypes, that is, datatypes closed under products, coproducts and fixpoints. We argue that the right methodology is on one hand coalgebraic (to deal with possible nontermination and infinite data) and on the other hand 2-categorical (to deal with parameters in a disciplined manner). We prove a coalgebraic version of Bekic lemma that allows us to reduce simultaneous fixpoints to a single fix point. Thus a possibly infinite object of interest is …

Coalgebraic Semantics Of Reflexive Economics (Dagstuhl Seminar 15042), Samson Abramsky, Alexander Kurz, Pierre Lescanne, Viktor Winschel

Engineering Faculty Articles and Research

This report documents the program and the outcomes of Dagstuhl Seminar 15042 “Coalgebraic Semantics of Reflexive Economics”.

Testing Data Vault-Based Data Warehouse, Connard N. Williams

College of Graduate Studies: Theses & Dissertations

Data warehouse (DW) projects are undertakings that require integration of disparate sources of data, a well-defined mapping of the source data to the reconciled data, and effective Extract, Transform, and Load (ETL) processes. Owing to the complexity of data warehouse projects, great emphasis must be placed on an agile-based approach with properly developed and executed test plans throughout the various stages of designing, developing, and implementing the data warehouse to mitigate against budget overruns, missed deadlines, low customer satisfaction, and outright project failures. Yet, there are often attempts to test the data warehouse exactly like traditional back-end databases and legacy …

Ultra-Fast, Autonomous, Reconfigurable Communication System, Paul Bupe Jr

College of Graduate Studies: Theses & Dissertations

The recent years have witnessed an increase in natural disasters in which the destruction of essential communication infrastructure has significantly affected the number of casualties. In 2005, Hurricane Katrina in the United States resulted in over 1,900 deaths, three million land-line phones disconnections, and more than 2000 cell sites going out of service. This incident highlighted an urgent need for a quick-deployment, efficient communication network for emergency relief purposes. In this research, a fully autonomous system to deploy Unmanned Aerial Vehicles (UAVs) as the first phase disaster recovery communication network for wide-area relief is presented. As part of this system, …

Computing And The Electrical Transport Properties Of Coupled Quantum Networks, Casey Andrew Cain

Doctoral Dissertations

In this dissertation a number of investigations were conducted on ballistic quantum networks in the mesoscopic range. In this regime, the wave nature of electron transport under the influence of transverse magnetic fields leads to interesting applications for digital logic and computing circuits. The work specifically looks at characterizing a few main areas that would be of interest to experimentalists who are working in nanostructure devices, and is organized as a series of papers. The first paper analyzes scaling relations and normal mode charge distributions for such circuits in both isolated and open (terminals attached) form. The second paper compares …

Reliability And Security In Low Power Circuits And Systems, Hui Geng

Doctoral Dissertations

"With the massive deployment of mobile devices in sensitive areas such as healthcare and defense, hardware reliability and security have become hot research topics in recent years. These topics, although different in definition, are usually correlated. This dissertation offers an in-depth treatment on enhancing the reliability and security of low power circuits and systems. The first part of the dissertation deals with the reliability of sub-threshold designs, which use supply voltage lower than the threshold voltage (V_th) of transistors to reduce power. The exponential relationship between delay and V_th significantly jeopardizes their reliability due to process variation …

Cormem Digital Reasoning Architecture Using Cmos Technology, Indira Priyadarshini Dugganapally

Doctoral Dissertations

”This dissertation describes the application of a multi-level, memory-based approach for building digital circuits. To reflect the alternative approach, the basic science is termed digital reasoning and the specific CorMem technology is based on recent patents. CMOS transistors are used in a non-traditional way for multi-level operations and memory manipulation. The combination of multi-level architectures and matrix algebra principles can create flexible, modular systems using standard fabrication methods and can avoid many of the limitations of other multi-valued logic approaches.

Quaternary, memory-based systems are developed to implement logic-gate-type functions, digital adder circuits, a complete arithmetic and logic unit (ALU), quaternary-to-binary …

Modular Timing Constraints For Delay-Insensitive Systems, Hoon Park, Anping He, Marly Roncken, Xiaoyu Song, Ivan Sutherland

Electrical and Computer Engineering Faculty Publications and Presentations

This paper introduces ARCtimer, a framework for modeling, generating, verifying, and enforcing timing constraints for individual self-timed handshake components. The constraints guarantee that the component’s gate-level circuit implementation obeys the component’s handshake protocol specification. Because the handshake protocols are delayinsensitive, self-timed systems built using ARCtimer-verified components are also delay-insensitive. By carefully considering time locally, we can ignore time globally. ARCtimer comes early in the design process as part of building a library of verified components for later system use. The library also stores static timing analysis (STA) code to validate and enforce the component’s constraints in any self-timed system built …

Virtualization Components Of The Modern Hypervisor, Sean Mcadams

UNF Graduate Theses and Dissertations

Virtualization is the foundation on which cloud services build their business. It supports the infrastructure for the largest companies around the globe and is a key component for scaling software for the ever-growing technology industry. If companies decide to use virtualization as part of their infrastructure it is important for them to quickly and reliably have a way to choose a virtualization technology and tweak the performance of that technology to fit their intended usage. Unfortunately, while many papers exist discussing and testing the performance of various virtualization systems, most of these performance tests do not take into account components …

Brand Positioning Map And Analysis Using Web Scraping And Advertisement Analysis, Surya Bhatt

Theses and Dissertations

There’s a significant increase in online consumer forums. When customers set out to buy a product they use these forums to form an opinion. Our research focuses on comparing Brand positioning maps based on consumer reviews. We also analyse the impact of advertisements and expert reviews. Our goal is to show that combining consumer reviews with ads and electronic media will help us analyze the effectiveness of advertising on brand positioning maps. This approach shall also help us in making association graphs for a brand using words of perception/opinion associated with that brand/product. Which may in turn assist companies in …

Identification And Exploitation Of Inadvertent Spectral Artifacts In Digital Audio, N. C. Donnangelo, W. S. Kuklinski, R. Szabo, R. A. Coury, G. R. Hamshar

Journal of Digital Forensics, Security and Law

We show that modulation products from local oscillators in a variety of commercial camcorders are coupled into the recorded audio track, creating narrow band time invariant spectral features. These spectral features, left largely intact by transcoding, compression and other forms of audiovisual post processing, can encode characteristics of specific camcorders used to capture the audio files, including the make and model. Using data sets both downloaded from YouTube and collected under controlled laboratory conditions we demonstrate an average probability of detection (Pd) approaching 0.95 for identification of a specific camcorder in a population of thousands of similar recordings, with a …

Computer Forensic Projects For Accountants, Grover S. Kearns

Journal of Digital Forensics, Security and Law

Digital attacks on organizations are becoming more common and more sophisticated. Firms are interested in providing data security and having an effective means to respond to attacks. Accountants possess important investigative and analytical skills that serve to uncover fraud in forensic investigations. Some accounting students take courses in forensic accounting but few colleges offer a course in computer forensics for accountants. Educators wishing to develop such a course may find developing the curriculum daunting. A major element of such a course is the use of forensic software. This paper argues the importance of computer forensics to accounting students and offers …

Data Loss Prevention Management And Control: Inside Activity Incident Monitoring, Identification, And Tracking In Healthcare Enterprise Environments, Manghui Tu, Kimberly Spoa-Harty, Liangliang Xiao

Journal of Digital Forensics, Security and Law

As healthcare data are pushed online, consumers have raised big concerns on the breach of their personal information. Law and regulations have placed businesses and public organizations under obligations to take actions to prevent data breach. Among various threats, insider threats have been identified to be a major threat on data loss. Thus, effective mechanisms to control insider threats on data loss are urgently needed. The objective of this research is to address data loss prevention challenges in healthcare enterprise environment. First, a novel approach is provided to model internal threat, specifically inside activities. With inside activities modeling, data …

Rules Of Professional Responsibility In Digital Forensics: A Comparative Analysis, Filipo Sharevski

Journal of Digital Forensics, Security and Law

The consolidation of the rules of professional responsibility as recommended by the Committee on Identifying the Needs of Forensic Sciences Community (2009) accents the establishment of an uniform code of ethics emphasizing the importance of enforceability in strengthening the role the forensic science plays within the criminal justice system. Equally pertinent for the domain of digital forensics, this imperative entails a research commitment in comparing and contrasting the respective codes of ethics to illustrate their “variety, specificity and enforceability” in order to inform the discussion on the regulative aspects of the digital forensic discipline. Accordingly, this paper reviews the professional …

On The Network Performance Of Digital Evidence Acquisition Of Small Scale Devices Over Public Networks, Irvin Homem, Spyridon Dosis

Journal of Digital Forensics, Security and Law

While cybercrime proliferates – becoming more complex and surreptitious on the Internet – the tools and techniques used in performing digital investigations are still largely lagging behind, effectively slowing down law enforcement agencies at large. Real-time remote acquisition of digital evidence over the Internet is still an elusive ideal in the combat against cybercrime. In this paper we briefly describe the architecture of a comprehensive proactive digital investigation system that is termed as the Live Evidence Information Aggregator (LEIA). This system aims at collecting digital evidence from potentially any device in real time over the Internet. Particular focus is made …

The "Bring Your Own Device" Conundrum For Organizations And Investigators: An Examination Of The Policy And Legal Concerns In Light Of Investigatory Challenges, Carla J. Utter, Alan Rea

Journal of Digital Forensics, Security and Law

In recent years, with the expansion of technology and the desire to downsize costs within the corporate culture, the technology trend has steered towards the integration of personally owned mobile devices (i.e. smartphones) within the corporate and enterprise environment. The movement, known as “Bring Your Own Device” (hereinafter referred to as “BYOD”), seeks to minimize or eliminate the need for two separate and distinct mobile devices for one employee. While taken at face value this trend seems favorable, the corporate policy and legal implications of the implementation of BYOD are further complicated by significant investigatory issues that far outweigh the …

Plc Forensics Based On Control Program Logic Change Detection, Ken Yau, Kam-Pui Chow

Journal of Digital Forensics, Security and Law

Supervisory Control and Data Acquisition (SCADA) system is an industrial control automated system. It is built with multiple Programmable Logic Controllers (PLCs). PLC is a special form of microprocessor-based controller with proprietary operating system. Due to the unique architecture of PLC, traditional digital forensic tools are difficult to be applied. In this paper, we propose a program called Control Program Logic Change Detector (CPLCD), it works with a set of Detection Rules (DRs) to detect and record undesired incidents on interfering normal operations of PLC. In order to prove the feasibility of our solution, we set up two experiments for …

Factors Influencing Digital Forensic Investigations: Empirical Evaluation Of 12 Years Of Dubai Police Cases, Ibtesam Alawadhi, Janet C. Read, Andrew Marrington, Virginia N. L. Franqueira

Journal of Digital Forensics, Security and Law

In Digital Forensics, the number of person-hours spent on investigation is a key factor which needs to be kept to a minimum whilst also paying close attention to the authenticity of the evidence. The literature describes challenges behind increasing person-hours and identifies several factors which contribute to this phenomenon. This paper reviews these factors and demonstrates that they do not wholly account for increases in investigation time. Using real case records from the Dubai Police, an extensive study explains the contribution of other factors to the increase in person-hours. We conclude this work by emphasizing on several factors affecting the …

Cyber Black Box/Event Data Recorder: Legal And Ethical Perspectives And Challenges With Digital Forensics, Michael Losavio, Pavel Pastukov, Svetlana Polyakova

Journal of Digital Forensics, Security and Law

With ubiquitous computing and the growth of the Internet of Things, there is vast expansion in the deployment and use of event data recording systems in a variety of environments. From the ships’ logs of antiquity through the evolution of personal devices for recording personal and environmental activities, these devices offer rich forensic and evidentiary opportunities that smash against rights of privacy and personality. The technical configurations of these devices provide for greater scope of sensing, interconnection options for local, near, and cloud storage of data, and the possibility of powerful analytics. This creates the unique situation of near-total data …

Two Challenges Of Stealthy Hypervisors Detection: Time Cheating And Data Fluctuations, Igor Korkin

Journal of Digital Forensics, Security and Law

Hardware virtualization technologies play a significant role in cyber security. On the one hand these technologies enhance security levels, by designing a trusted operating system. On the other hand these technologies can be taken up into modern malware which is rather hard to detect. None of the existing methods is able to efficiently detect a hypervisor in the face of countermeasures such as time cheating, temporary self uninstalling, memory hiding etc. New hypervisor detection methods which will be described in this paper can detect a hypervisor under these countermeasures and even count several nested ones. These novel approaches rely on …

Data Extraction On Mtk-Based Android Mobile Phone Forensics, Joe Kong

Journal of Digital Forensics, Security and Law

In conducting criminal investigations it is quite common that forensic examiners need to recover evidentiary data from smartphones used by offenders. However, examiners encountered difficulties in acquiring complete memory dump from MTK Android phones, a popular brand of smartphones, due to a lack of technical knowledge on the phone architecture and that system manuals are not always available. This research will perform tests to capture data from MTK Android phone by applying selected forensic tools and compare their effectiveness by analyzing the extracted results. It is anticipated that a generic extraction tool, once identified, can be used on different brands …

Exploring The Use Of Plc Debugging Tools For Digital Forensic Investigations On Scada Systems, Tina Wu, Jason R.C. Nurse

Journal of Digital Forensics, Security and Law

The Stuxnet malware attack has provided strong evidence for the development of a forensic capability to aid in thorough post-incident investigations. Current live forensic tools are typically used to acquire and examine memory from computers running either Windows or Unix. This makes them incompatible with embedded devices found on SCADA systems that have their own bespoke operating system. Currently, only a limited number of forensics tools have been developed for SCADA systems, with no development of tools to acquire the program code from PLCs. In this paper, we explore this problem with two main hypotheses in mind. Our first hypothesis …

Forensic Acquisition Of Imvu: A Case Study, Robert Van Voorst, M-Tahar Kechadi, Nhien-An Le-Khac

Journal of Digital Forensics, Security and Law

There are many applications available for personal computers and mobile devices that facilitate users in meeting potential partners. There is, however, a risk associated with the level of anonymity on using instant message applications, because there exists the potential for predators to attract and lure vulnerable users. Today Instant Messaging within a Virtual Universe (IMVU) combines custom avatars, chat or instant message (IM), community, content creation, commerce, and anonymity. IMVU is also being exploited by criminals to commit a wide variety of offenses. However, there are very few researches on digital forensic acquisition of IMVU applications. In this paper, we …

Tracking And Taxonomy Of Cyberlocker Link Sharers Based On Behavior Analysis, Xiao-Xi Fan, Kam-Pui Chow

Journal of Digital Forensics, Security and Law

The growing popularity of cyberlocker service has led to significant impact on the Internet that it is considered as one of the biggest contributors to the global Internet traffic estimated to be illegally traded content. Due to the anonymity property of cyberlocker, it is difficult for investigators to track user identity directly on cyberlocker site. In order to find the potential relationships between cyberlocker users, we propose a framework to collect cyberlocker related data from public forums where cyberlocker users usually distribute cyberlocker links for others to download and identity information can be gathered easily. Different kinds of sharing behaviors …