3,840 research outputs found
Minimising the heat dissipation of quantum information erasure
Quantum state engineering and quantum computation rely on information erasure
procedures that, up to some fidelity, prepare a quantum object in a pure state.
Such processes occur within Landauer's framework if they rely on an interaction
between the object and a thermal reservoir. Landauer's principle dictates that
this must dissipate a minimum quantity of heat, proportional to the entropy
reduction that is incurred by the object, to the thermal reservoir. However,
this lower bound is only reachable for some specific physical situations, and
it is not necessarily achievable for any given reservoir. The main task of our
work can be stated as the minimisation of heat dissipation given probabilistic
information erasure, i.e., minimising the amount of energy transferred to the
thermal reservoir as heat if we require that the probability of preparing the
object in a specific pure state be no smaller than
. Here is the maximum
probability of information erasure that is permissible by the physical context,
and the error. To determine the achievable minimal heat
dissipation of quantum information erasure within a given physical context, we
explicitly optimise over all possible unitary operators that act on the
composite system of object and reservoir. Specifically, we characterise the
equivalence class of such optimal unitary operators, using tools from
majorisation theory, when we are restricted to finite-dimensional Hilbert
spaces. Furthermore, we discuss how pure state preparation processes could be
achieved with a smaller heat cost than Landauer's limit, by operating outside
of Landauer's framework
Combining Plant Pathogenic Fungi and the Leaf-Mining Fly, Hydrellia pakistanae, Increases Damage to Hydrilla
Four fungal species, F71PJ
Acremonium
sp., F531
Cylindrocarpon
sp., F542,
Botrytis
sp., and F964
Fusarium culmorum
[Wm. G. Sm.] Sacc. were recovered from hydrilla [
Hydrilla
verticillata
(L. f.) Royle] shoots or from soil and water surrounding
hydrilla growing in ponds and lakes in Florida and
shown to be capable of killing hydrilla in a bioassay. The isolates
were tested singly and in combination with the leaf-mining
fly,
Hydrellia pakistanae
(Diptera: Ephydridae), for their
capability to kill or severely damage hydrilla in a bioassay
Coupling of pinned magnetic moments in an antiferromagnet to a ferromagnet and its role for exchange bias
The interaction between uncompensated pinned magnetic moments within an antiferromagnetic (AFM) layer and an adjacent ferromagnetic (FM) layer responsible for the existence of exchange bias is explored in epitaxially grown trilayers of the form FM2/AFM/FM1 on Cu3Au(0 0 1) where FM1 is ~12 atomic monolayers (ML) Ni, FM2 is 21–25 ML Ni, and AFM is 27 ML or 50 ML Ni~25Mn~75. Field cooling for parallel or antiparallel alignment of the out-of-plane magnetizations of the two FM layers does not make a difference for the temperature-dependent coercivity (H C), magnitude of exchange bias field (H eb), AFM ordering temperature (T AFM), and blocking temperature for exchange bias (T b). We explain this by a model in which the uncompensated pinned magnetic moments distributed within the volume of the AFM layer interact with both of the FM layers, albeit with different strength. Parallel and antiparallel coupling between the magnetization of the pinned moments and the FM layers equally exists. This leads to the experimentally observed independence of H C, H eb, as well as of T AFM and T b on the magnetization direction of the FM layers during field cooling. These results provide new and detailed insight into revealing the subtle and complex nature of the exchange bias effect
Trade Openness, Foreign Direct Investment and Infrastructure Spending: A Comparative Analysis of Their Common Role in the Economic Development Between Selected Developed and Developing Economies
This study examines the literature on how trade, foreign direct investments, and infrastructure development affect economic growth of selected developed and developing economies. A comparative analysis will be carried between developed economies (G7 countries) represented by Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States while the developing economies (BRICS countries) are represented by Brazil, Russia, India, China and South Africa. The comparative analysis will be carried between years 1985 to 2015. In addition, the paper will establish the relationship between trade and economic growth in both developing and developed economies. Furthermore, the paper will establish that trade variables in both developed and developing economies is captured in three indicators namely, the sum of exports and imports to the Gross Domestic Product (GDP), the ratio of imports to the GDP and the ratio of exports to GDP.
This study utilizes a panel data approach to form and capture the threshold effect between economic growth and trade. Moreover, the relationship between Foreign Direct Investment (FDI) and economic growth will be analyzed. The research will depict that trade and FDI are expressed as the ratio of GDP in both developed and developing economies. In addition, the co-relation between the FDIs and the GDP rate is inherent to the volume of investments brought into the host country. Moreover, the relationship between infrastructure represented as GCF and economic development in both developing and developed economies will be discussed by this proposal. The proposal will establish that infrastructure outputs such as power, transport, and water are used as production inputs in productive sectors such as manufacturing and agriculture, therefore forming a close relationship between GDP and infrastructure. The study will conclude by establishing the relationship of the three variables (trade liberation, FDI and infrastructure spending) in economic development in both developed (G7 economies) and developing economies (BRICS economies)
Imaging ductal carcinoma using a hyperspectral imaging system
Hyperspectral Imaging (HSI) is a non-invasive optical imaging modality that shows the potential to aid pathologists in breast cancer diagnoses cases. In this study, breast cancer tissues from different patients were imaged by a hyperspectral system to detect spectral differences between normal and breast cancer tissues, as well as early and late stages of breast cancer. If the spectral differences in these tissue types can be measured, automated systems can be developed to help the pathologist identify suspect biopsy samples, which will improve sample throughput and assist in making critical treatment decisions. Tissue samples from ten different patients were provided by the WVU Pathology Department. The samples from each patient included both normal and ductal carcinoma tissue, both stained and unstained. These cells were imaged using a snapshot HSI system, and the spectral reflectances were evaluated to see if there was a measurable spectral difference between the various cell types. Analysis of the spectral reflectance values indicated that wavelengths near 550nm show the best differentiation between tissue types. This information was used to train image processing algorithms using supervised and unsupervised data. K-Means and Support Vector Machine (SVM) approaches were applied to the hyperspectral data cubes, and successfully detected spectral tissue differences with sensitivity of 85.45%, and specificity of 94.64% with TNR of 95.8%, and FPR of 4.2%. These results were verified by ground truth marking of the tissue samples by a pathologist. This interdisciplinary work will build a bridge between pathology and hyperspectral optical diagnostic imaging in order to reduce time and workload on the pathologist, which can lead to benefit of lead reducing time, and increasing the accuracy of diagnoses
Effectiveness of the antifungal black seed oil against powdery mildews of cucumber (Podosphaera xanthii) and barley (Blumeria graminis f.sp. hordei)
When cucumber and barley leaves were sprayed with 0.5% black seed oil (BSO), rapeseed oil (R oil) and parafine oil (P oil), disease severity of the powdery mildew of cucumber (Podosphaera xanthii) was reduced from 52% (control) to 7.7% (BSO), 18.6% (R oil) and 20% (P oil). Similarly the disease severity of barley powdery mildew (Blumeria graminis f.sp. hordei) was greatly reduced from 63.4% (control) to 9.4% (BSO), 16% (R oil) and 16.4% (P oil). Oils inhibited the conidial germination of cucumber and barley powdery mildews to 29-30.7, 35-38 and 37-41% respectively, as compared to control (58-65%). Furthermore, mycelial growth of the pathogen was severely restricted after application of BSO and other oils. Levels of hydrogen peroxide (H2O2) and superoxide (O2.-) as well as the activity of the antioxidant enzymes in the treated leaves with oils and untreated (control) were measured and determined. H2O2 and O2.-levels slightly increased, however some antioxidants are decreased such as dehydroascorbate reductase (DHAR) but other enzymes were increased such as ascorbate peroxidase (APX) and glutathione S transferase (GST). It can be concluded that the protective effect of oils against powdery mildews resulted mainly from the inhibition of conidial germination and suppression of the mycelial growth of the pathogens and there is slight activation of the host defence mechanisms. Therefore, it is important to giving more attention to BSO and other oils which have effectiveness against powdery mildew pathogens as an alternative control methods which safety and suitable for healthy and organic food production
A Framework for an Adaptive Early Warning and Response System for Insider Privacy Breaches
Organisations such as governments and healthcare bodies are increasingly responsible for managing large amounts of personal information, and the increasing complexity of modern information systems is causing growing concerns about the protection of these assets from insider threats. Insider threats are very difficult to handle, because the insiders have direct access to information and are trusted by their organisations. The nature of insider privacy breaches varies with the organisation’s acceptable usage policy and the attributes of an insider. However, the level of risk that insiders pose depends on insider breach scenarios including their access patterns and contextual information, such as timing of access. Protection from insider threats is a newly emerging research area, and thus, only few approaches are available that systemise the continuous monitoring of dynamic insider usage characteristics and adaptation depending on the level of risk. The aim of this research is to develop a formal framework for an adaptive early warning and response system for insider privacy breaches within dynamic software systems. This framework will allow the specification of multiple policies at different risk levels, depending on event patterns, timing constraints, and the enforcement of adaptive response actions, to interrupt insider activity.
Our framework is based on Usage Control (UCON), a comprehensive model that controls previous, ongoing, and subsequent resource usage. We extend UCON to include interrupt policy decisions, in which multiple policy decisions can be expressed at different risk levels. In particular, interrupt policy decisions can be dynamically adapted upon the occurrence of an event or over time. We propose a computational model that represents the concurrent behaviour of an adaptive early warning and response system in the form of statechart. In addition, we propose a Privacy Breach Specification Language (PBSL) based on this computational model, in which event patterns, timing constraints, and the triggered early warning level are expressed in the form of policy rules. The main features of PBSL are its expressiveness, simplicity, practicality, and formal semantics. The formal semantics of the PBSL, together with a model of the mechanisms enforcing the policies, is given in an operational style. Enforcement mechanisms, which are defined by the outcomes of the policy rules, influence the system state by mutually interacting between the policy rules and the system behaviour. We demonstrate the use of this PBSL with a case study from the e-government domain that includes some real-world insider breach scenarios. The formal framework utilises a tool that supports the animation of the enforcement and policy models. This tool also supports the model checking used to formally verify the safety and progress properties of the system over the policy and the enforcement specifications
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