1,720 research outputs found

    A Critical Review Of Post-Secondary Education Writing During A 21st Century Education Revolution

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    Educational materials are effective instruments which provide information and report new discoveries uncovered by researchers in specific areas of academia. Higher education, like other education institutions, rely on instructional materials to inform its practice of educating adult learners. In post-secondary education, developmental English programs are tasked with meeting the needs of dynamic populations, thus there is a continuous need for research in this area to support its changing landscape. However, the majority of scholarly thought in this area centers on K-12 reading and writing. This paucity presents a phenomenon to the post-secondary community. This research study uses a qualitative content analysis to examine peer-reviewed journals from 2003-2017, developmental online websites, and a government issued document directed toward reforming post-secondary developmental education programs. These highly relevant sources aid educators in discovering informational support to apply best practices for student success. Developmental education serves the purpose of addressing literacy gaps for students transitioning to college-level work. The findings here illuminate the dearth of material offered to developmental educators. This study suggests the field of literacy research is fragmented and highlights an apparent blind spot in scholarly literature with regard to English writing instruction. This poses a quandary for post-secondary literacy researchers in the 21st century and establishes the necessity for the literacy research community to commit future scholarship toward equipping college educators teaching writing instruction to underprepared adult learners

    Towards trustworthy computing on untrustworthy hardware

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    Historically, hardware was thought to be inherently secure and trusted due to its obscurity and the isolated nature of its design and manufacturing. In the last two decades, however, hardware trust and security have emerged as pressing issues. Modern day hardware is surrounded by threats manifested mainly in undesired modifications by untrusted parties in its supply chain, unauthorized and pirated selling, injected faults, and system and microarchitectural level attacks. These threats, if realized, are expected to push hardware to abnormal and unexpected behaviour causing real-life damage and significantly undermining our trust in the electronic and computing systems we use in our daily lives and in safety critical applications. A large number of detective and preventive countermeasures have been proposed in literature. It is a fact, however, that our knowledge of potential consequences to real-life threats to hardware trust is lacking given the limited number of real-life reports and the plethora of ways in which hardware trust could be undermined. With this in mind, run-time monitoring of hardware combined with active mitigation of attacks, referred to as trustworthy computing on untrustworthy hardware, is proposed as the last line of defence. This last line of defence allows us to face the issue of live hardware mistrust rather than turning a blind eye to it or being helpless once it occurs. This thesis proposes three different frameworks towards trustworthy computing on untrustworthy hardware. The presented frameworks are adaptable to different applications, independent of the design of the monitored elements, based on autonomous security elements, and are computationally lightweight. The first framework is concerned with explicit violations and breaches of trust at run-time, with an untrustworthy on-chip communication interconnect presented as a potential offender. The framework is based on the guiding principles of component guarding, data tagging, and event verification. The second framework targets hardware elements with inherently variable and unpredictable operational latency and proposes a machine-learning based characterization of these latencies to infer undesired latency extensions or denial of service attacks. The framework is implemented on a DDR3 DRAM after showing its vulnerability to obscured latency extension attacks. The third framework studies the possibility of the deployment of untrustworthy hardware elements in the analog front end, and the consequent integrity issues that might arise at the analog-digital boundary of system on chips. The framework uses machine learning methods and the unique temporal and arithmetic features of signals at this boundary to monitor their integrity and assess their trust level

    Security Elites in Egypt and Jordan after the Arab Spring : A Case Study on Securocracies’ Role on National Security, Domestic Power Politics, Regional Order and Middle Eastern Alliance Making between 2011 and 2021

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    The doctoral dissertation studied changes in the balance of power, alliance making and the hegemonic struggles of security elites within a Middle Eastern regional context over a ten year reference period between 2011 and 2021. The study focused on two case study countries: Egypt and Jordan. The results were compared within a historical context to the pre-Arab Spring era. The theoretical approach combined the English School of Thought and Middle Eastern Studies with a conceptual model of securocracy developed by the author. The primary contribution of the research is the realization of the core importance of securocracy within autocratic state systems. Inside securocracies there exists rivalling groups and organisations that counterbalance each other. The study points to the fact that the power struggle between executive powers – either purely domestic one or supported by foreign involvement, is the main driver behind why case study countries were in varying degrees dragged into instability and turmoil in the aftermath of the Arab Spring. Securocracies can be divided into two main types: centralised and decentralised. The centralised model occurs when different elites groups have the same ”distance” to the ruler while having equal privileges and equal access to political power. The model predicts durability and stability of the regime (status quo). In the de-centralised model, there is an ongoing struggle amongst elite groups and “distances” to ruler are not equal, neither are the privileges. In Egypt the hegemonic struggle amongst elites took precedence over the interests and stability of the state after the Arab Spring and has continued since then. The situation at the end of 2021 is a de-centralised model where all executive powers are concentrated within President al-Sisi’s family dynasty (palace) and the leadership of military intelligence. This de-centralised type of securocracy makes Egypt’s situation fragile. Any impact from the outside, such as the Biden administration’s decision to impose additional conditions on U.S. financial military aid, could lead to a new hegemonic struggle challenging al-Sisi’s power. The securocracy’s survival strategy found in the study was the use of vertical power at all levels of the state hierarchy (” the winner takes it all”). In the situation of a power struggle, the ruler uses omni-balancing i.e., alliance making with powerful foreign states in order to gain an advantage against domestic rivals and revisionist regional states. The Egyptian example is al-Sisi’s rapprochement with Russia’s President Putin and his distancing of Egypt from its previous role of being the United States’ loyal Middle Eastern ally. The Jordanian example however, is the opposite, resulting in even closer relations with the United States since January 2021 when the two countries signed an updated Status of Forces Agreement (SOFA). The study also highlights that decisions concerning ruler succession in authoritarian states take place behind-the-scenes amongst the securocracy as it, per rule, prefers to choose a member inside its own interest group or alternatively a political figurehead that commits to protect securocracy’s privileged interests in exchange of their own power position. Within the Middle East, the recent U.S. pivot to Asia-Pacific created an opportunity for Russia to make a come-back. Russia, however, does not have the resources to compensate for the loss of U.S. financial military aid to the security elites. This in turn, and with Russia’s consent, has given space for regional state actors, particularly, the United Arab Emirates and Saudi-Arabia, to increase their influence. Gulf support to the regional clients is not free of charge: they request their clients adopt their own threat perceptions, take sides in armed conflicts and contribute to military capabilities which support the sponsors’ regional foreign and security policy goals.Väitöstutkimuksessa tarkasteltiin kymmenen vuoden ajanjaksolla voimatasapainon muutosta Lähi-idän alueellisessa valtarakenteessa, liittolaissuhteiden muutoksia sekä turvallisuuseliittien roolia maan sisäisessä valtataistelussa. Tuloksia verrattiin historiallisessa kontekstissa arabikevättä edeltävään aikaan kahdessa tapaustutkimusmaassa: Egyptissä ja Jordaniassa. Teoriaviitekehyksenä sovellettiin Englantilaisen koulukunnan ja Lähi-idän tutkimuksen teoriamalleja, sekä tutkijan kehittelemää sekurokratian konseptuaalista mallia. Tutkimuksen keskeinen tulos on havainto sekurokratian merkittävästä roolista osana autoritaarista valtiomallia. Sekurokratian sisälle on luotu useita toinen toistaan tasapainottavia ryhmittymiä. Tapaustutkimusmaiden arabikevään jälkeisen turvallisuustilanteen muutoksia selittävien tekijöiden joukossa turvallisuuseliittien valtakamppailu nousi merkittävään rooliin. Valtakamppailua käytiin eliittien kesken joko pelkästään maan sisällä tai vaihtoehtoisesti osin myös valtion ulkopuolisten voimien tukemana. Tutkimuksen perusteella sekurokratiat voidaan jakaa kahteen päätyyppiin: keskitettyyn ja hajautettuun malliin. Jos eri turvallisuuseliitti-ryhmien edut, vallankäyttö ja etäisyys vallan keskipisteeseen ovat tasapainossa puhutaan keskitetyn sekurokratian mallista, mikä ennustaa vallassa olevan regiimin pysyvyyttä ja vakautta. Jos taas sekurokratian rakenne on hajautetun mallin mukainen, sen valtakamppailu voi johtaa yhden osan pyrkimyksiin hegemonia-asemasta. Egyptin tapauksessa arabikevään jälkeinen turvallisuuseliittien valtakamppailu asetettiin maan vakauden edelle ja eliittien valtakamppailu on jatkunut tähän päivään. Tilanteessa vuoden 2021 lopussa valta on al-Sisin perhedynastialla ja sotilastiedustelun eliitillä (hajautettu malli). Hajautettu malli ei ennusta pitkäaikaista vallassa pysymistä; vahva ulkopuolinen heräte, esimerkiksi Bidenin hallinnon sotilaallisen talousavun lopettaminen voisi johtaa uuteen valtakamppailuun ja al-Sisin valta-aseman haastamiseen. Tutkimustulokset osoittavat, että sekurokratoiden selviytymisstrategiana on vallanvertikaalin käyttö valtiohallinnon eri tasoilla. Valtakamppailun tilanteessa käytetään tasapainotusstrategiaa (omni-balancing), missä alueellisia vahvoja valtioita ja suurvaltoja pyritään yhdistämään hallitsijan puolelle kilpailevia eliittiryhmittymiä tai revisionistisia ulkovaltoja vastaan. Egyptissä presidentti al-Sisin valtaannousu johti maan lähentymiseen presidentti Putinin Venäjän kanssa sekä etääntymiseen aiemmasta Yhdysvalloille uskollisen Lähi-idän liittolaisen roolista. Jordaniassa puolestaan maa on nyt entistä tiiviimmin liittoutunut Yhdysvaltojen kanssa. Esimerkkinä tästä on tammikuussa 2021 maiden kesken solmittu sotilasyhteistyötä ja jordanialaisten tukikohtien käyttöä säätelevä isäntämaatuki-sopimus. Tutkimustulosten valossa autoritaariselle vallanperimykselle tyypillistä on se, että julkisuuteen näkymättömän sisäisen valtakamppailun jälkeen uudeksi valtionpäämieheksi pyritään nostamaan sekurokratian sisältä sen oman intressiryhmän edustaja, tai vaihtoehtoisesti sekurokratian valitsema ulkopuolinen poliitikko, jonka vastuulle korporaation intressien vaaliminen lankeaa vastapalveluksena sekurokratian tuesta keulakuva-poliitikon vallassa pitämiseksi. Alueellisen turvallisuusjärjestyksen osalta tutkimuksen tulokset osoittavat sen, että Yhdysvaltojen painopisteen siirto Tyynellemerelle vii ja Aasiaan on antanut Venäjälle mahdollisuuden palauttaa vaikutusvaltaansa Lähiitään. Venäjällä ei kuitenkaan ole resursseja kompensoida Yhdysvaltojen arabivaltioiden turvallisuuseliiteille allokoimaa taloudellista tukea. Tämä on antanut tilaa alueellisten toimijoiden kuten Yhdistyneiden arabiemiirikuntien ja Saudi-Arabian vaikutusvallan kasvattamiselle - tosin Venäjän hyväksynnällä. Tuki ei myöskään tule ilmaiseksi, sillä sponsorit edellyttävät, että niille alisteisessa asemassa olevat maat omaksuvat tukijavaltioidensa uhkakuvat, sekä konfliktitilanteissa kontribuoivat sotilaallisia kyvykkyyksiä näiden valtioiden ulko- ja turvallisuuspoliittisten päämäärien saavuttamiseksi

    Software Fault Tolerance in Real-Time Systems: Identifying the Future Research Questions

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    Tolerating hardware faults in modern architectures is becoming a prominent problem due to the miniaturization of the hardware components, their increasing complexity, and the necessity to reduce the costs. Software-Implemented Hardware Fault Tolerance approaches have been developed to improve the system dependability to hardware faults without resorting to custom hardware solutions. However, these come at the expense of making the satisfaction of the timing constraints of the applications/activities harder from a scheduling standpoint. This paper surveys the current state of the art of fault tolerance approaches when used in the context real-time systems, identifying the main challenges and the cross-links between these two topics. We propose a joint scheduling-failure analysis model that highlights the formal interactions among software fault tolerance mechanisms and timing properties. This model allows us to present and discuss many open research questions with the final aim to spur the future research activities

    Accessibility of Health Data Representations for Older Adults: Challenges and Opportunities for Design

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    Health data of consumer off-the-shelf wearable devices is often conveyed to users through visual data representations and analyses. However, this is not always accessible to people with disabilities or older people due to low vision, cognitive impairments or literacy issues. Due to trade-offs between aesthetics predominance or information overload, real-time user feedback may not be conveyed easily from sensor devices through visual cues like graphs and texts. These difficulties may hinder critical data understanding. Additional auditory and tactile feedback can also provide immediate and accessible cues from these wearable devices, but it is necessary to understand existing data representation limitations initially. To avoid higher cognitive and visual overload, auditory and haptic cues can be designed to complement, replace or reinforce visual cues. In this paper, we outline the challenges in existing data representation and the necessary evidence to enhance the accessibility of health information from personal sensing devices used to monitor health parameters such as blood pressure, sleep, activity, heart rate and more. By creating innovative and inclusive user feedback, users will likely want to engage and interact with new devices and their own data

    Design and Advanced Model Predictive Control of Wide Bandgap Based Power Converters

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    The field of power electronics (PE) is experiencing a revolution by harnessing the superior technical characteristics of wide-band gap (WBG) materials, namely Silicone Carbide (SiC) and Gallium Nitride (GaN). Semiconductor devices devised using WBG materials enable high temperature operation at reduced footprint, offer higher blocking voltages, and operate at much higher switching frequencies compared to conventional Silicon (Si) based counterpart. These characteristics are highly desirable as they allow converter designs for challenging applications such as more-electric-aircraft (MEA), electric vehicle (EV) power train, and the like. This dissertation presents designs of a WBG based power converters for a 1 MW, 1 MHz ultra-fast offboard EV charger, and 250 kW integrated modular motor drive (IMMD) for a MEA application. The goal of these designs is to demonstrate the superior power density and efficiency that are achievable by leveraging the power of SiC and GaN semiconductors. Ultra-fast EV charging is expected to alleviate the challenge of range anxiety , which is currently hindering the mass adoption of EVs in automotive market. The power converter design presented in the dissertation utilizes SiC MOSFETs embedded in a topology that is a modification of the conventional three-level (3L) active neutral-point clamped (ANPC) converter. A novel phase-shifted modulation scheme presented alongside the design allows converter operation at switching frequency of 1 MHz, thereby miniaturizing the grid-side filter to enhance the power density. IMMDs combine the power electronic drive and the electric machine into a single unit, and thus is an efficient solution to realize the electrification of aircraft. The IMMD design presented in the dissertation uses GaN devices embedded in a stacked modular full-bridge converter topology to individually drive each of the motor coils. Various issues and solutions, pertaining to paralleling of GaN devices to meet the high current requirements are also addressed in the thesis. Experimental prototypes of the SiC ultra-fast EV charger and GaN IMMD were built, and the results confirm the efficacy of the proposed designs. Model predictive control (MPC) is a nonlinear control technique that has been widely investigated for various power electronic applications in the past decade. MPC exploits the discrete nature of power converters to make control decisions using a cost function. The controller offers various advantages over, e.g., linear PI controllers in terms of fast dynamic response, identical performance at a reduced switching frequency, and ease of applicability to MIMO applications. This dissertation also investigates MPC for key power electronic applications, such as, grid-tied VSC with an LCL filter and multilevel VSI with an LC filter. By implementing high performance MPC controllers on WBG based power converters, it is possible to formulate designs capable of fast dynamic tracking, high power operation at reduced THD, and increased power density

    Synthesizing FDIR Recovery Strategies for Space Systems

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    Dynamic Fault Trees (DFTs) are powerful tools to drive the design of fault tolerant systems. However, semantic pitfalls limit their practical utility for interconnected systems that require complex recovery strategies to maximize their reliability. This thesis discusses the shortcomings of DFTs in the context of analyzing Fault Detection, Isolation and Recovery (FDIR) concepts with a particular focus on the needs of space systems. To tackle these shortcomings, we introduce an inherently non-deterministic model for DFTs. Deterministic recovery strategies are synthesized by transforming these non-deterministic DFTs into Markov automata that represent all possible choices between recovery actions. From the corresponding scheduler, optimized to maximize a given RAMS (Reliability, Availability, Maintainability and Safety) metric, an optimal recovery strategy can then be derived and represented by a model we call recovery automaton. We discuss dedicated techniques for reducing the state space of this recovery automaton and analyze their soundness and completeness. Moreover, modularized approaches to handle the complexity added by the state-based transformation approach are discussed. Furthermore, we consider the non-deterministic approach in a partially observable setting and propose an approach to lift the model for the fully observable case. We give an implementation of our approach within the Model-Based Systems Engineering (MBSE) framework Virtual Satellite. Finally, the implementation is evaluated based on the FFORT benchmark. The results show that basic non-deterministic DFTs generally scale well. However, we also found that semantically enriched non-deterministic DFTs employing repair or delayed observability mechanisms pose a challenge
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