3,773 research outputs found
Application-aware Energy Attack Mitigation in the Battery-less Internet of Things
No full textWe study how to mitigate the effects of energy attacks in the battery-less Internet of Things (IoT). Battery-less IoT devices live and die with ambient energy, as they use energy harvesting to power their operation. They are employed in a multitude of applications, including safety-critical ones such as biomedical implants. Due to scarce energy intakes and limited energy buffers, their executions become intermittent, alternating periods of active operation with periods of recharging their energy buffers. Experimental evidence exists that shows how controlling ambient energy allows an attacker to steer a device execution in unintended ways: energy provisioning effectively becomes an attack vector. We design, implement, and evaluate a mitigation system for energy attacks. By taking into account the specific application requirements and the output of an attack detection module, we tune task execution rates and optimize energy management. This ensures continued application execution in the event of an energy attack. When a device is under attack, our solution ensures the execution of 23.3% additional application cycles compared to the baselines we consider and increases task schedulability by at least 21%, while enabling a 34% higher peripheral availability
Exercise related anxiety-like behaviours are mediated by TNF receptor signaling, but not depression-like behaviours
No full textAvailable online 22 May 2018Abstract not availableJulie A. Morgan, Gaurav Singhal, Frances Corrigan, Emily J. Jaehne, Magdalene C. Jawahar, Bernhard T. Baun
Cytokine levels in major depression are related to childhood trauma but not to recent stressors
No full textAbstract not availableLaura Grosse, Oliver Ambrée, Silke Jörgens, M. Catharine Jawahar, Gaurav Singhal, David Stacey, Volker Arolt, Bernhard T. Baun
Understanding the importance of side information in graph matching problem
No full textGraph matching algorithms rely on the availability of seed vertex pairs as side information to deanonymize users across networks. Although such algorithms work well in practice, there are other types of side information available which are potentially useful to an attacker. In this thesis, we consider the problem of matching two correlated graphs when an attacker has access to side information either in the form of community labels or an imperfect initial matching. First, we propose a naive graph matching algorithm by introducing the community degree vectors which harness the information from community labels in an e cient manner. Next, we analyze the basic percolation algorithm for graphs with community structure. Finally, we propose a novel percolation algorithm with two thresholds which uses an imperfect matching as input to match correlated graphs. We also analyze these algorithms and provide theoretical guarantees for matching graphs generated using the Stochastic Block Model.
We evaluate the proposed algorithms on synthetic as well as real world datasets using various experiments. The experimental results demonstrate the importance of communities as side information especially when the number of seeds is small and the networks are weakly correlated. These results motivate the study of other types of potential side information available to the attacker. Such studies could assist in devising mechanisms to counter the effects of side information in network deanonymization.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-12-01The student, Kushagra Singhal, accepted the attached license on 2016-11-22 at 11:10.The student, Kushagra Singhal, submitted this Thesis for approval on 2016-11-22 at 11:16.This Thesis was approved for publication on 2016-11-22 at 12:00.DSpace SAF Submission Ingestion Package generated from Vireo submission #10224 on 2017-02-28 at 14:36:15Made available in DSpace on 2017-03-01T16:36:46Z (GMT). No. of bitstreams: 2
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Previous issue date: 2016-11-22Embargo set by: Seth Robbins for item 98583
Lift date: 2019-03-01T16:37:19Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 98583 on 2019-03-02T10:15:33Z
Phase 1 study to determine the safety, tolerability and immunostimulatory activity of thalidomide analogue CC-5013 in patients with metastatic malignant melanoma and other advanced cancers
No full textWe assessed the safety, tolerability and efficacy of the immunomodulatory drug, CC-5013 (REVIMID(TM)), in the treatment of patients with metastatic malignant melanoma and other advanced cancers. A total of 20 heavily pretreated patients received a dose-escalating regimen of oral CC-5013. Maximal tolerated dose, toxicity and clinical responses were evaluated and analysis of peripheral T-cell surface markers and serum for cytokines and proangiogenic factors were performed. CC-5013 was well tolerated. In all, 87% of adverse effects were classified as grade 1 or grade 2 according to Common Toxicity Criteria and there were no serious adverse events attributable to CC-5013 treatment. Six patients failed to complete the study, three because of disease progression, two withdrew consent and one was entered inappropriately and withdrawn from the study. The remaining 14 patients completed treatment without dose reduction, with one patient achieving partial remission. Evidence of T-cell activation was indicated by significantly increased serum levels of sIL-2 receptor, granulocyte- macrophage colony-stimulating factor, interleukin-12 (IL-12), tumour necrosis factor-alpha and IL-8 in nine patients from whom serum was available. However, levels of proangiogenic factors vascular endothelial growth factor and basic foetal growth factor were not consistently affected, This study demonstrates the safety, tolerability and suggests the clinical activity of CC-5013 in the treatment of refractory malignant melanoma. Furthermore, this is the first report demonstrating T-cell stimulatory activity of this class of compound in patients with advanced cancer
Automatic topic detection strategy for information retrieval in spoken document
No full textThis paper suggests an alternative solution for the task of spoken document retrieval (SDR). The proposed system runs retrieval on multi-level transcriptions (word and phone) produced by word and phone recognizers respectively, and their outputs are combined. We propose to use latent Dirichlet allocation (LDA) model for capturing the semantic information on word transcription. The LDA model is employed for estimating topic distribution in queries and word transcribed spoken documents, and the matching is performed at the topic level. Acoustic matching between query words and phonetically transcribed spoken documents is performed using phone-based matching algorithm. The results of acoustic and topic level matching methods are compared and shown to be complementary
A new framework of optimizing keyword weights in text categorization and record querying
No full textIn text mining research, the Vector Space Model (VSM) has been commonly used to represent text documents as a vector where each component is associated with a particular word in the documents. Assigning appropriate keyword weights in VSM has been critical in Information Retrieval (IR) and Text Categorization (TC).
Traditionally keyword weighting processes are unsupervised; that is, the knowledge of document's category is not leveraged to label the documents. Typically, each keyword weight is assigned using the term frequency -- inverse document frequency (TFIDF) measure. Although the TFIDF measure has been proven effective in several text mining problems, it might not give the optimal classification power for IR and TC. In this thesis, we propose a new optimization framework to find the best keyword weights based on the proposed inter-class and intra-class similarity concept.
The optimal keyword weight can be viewed as the feature space projection where documents from the same category are best clustered together and separated from other categories. Subsequently, the category average (centroid) classification is employed to categorize text documents. The proposed approach is tested on two practical applications: record query and text categorization. The record query application is slightly different from traditional IR problems as the goal is to find correlated (duplicate and master) text records. This problem was initiated by a telecommunication company where service engineers attempt to look for associations of the current defect problem in previously recorded problems in the database. Extensive experiments demonstrate that the proposed framework significantly improves the classification accuracy and provides balanced performance as measured on all text categories when compared to the standard TFIDF search. The text categorization application is tested on the Reuters news data set which is a gold-standard benchmark data set. The results show that our framework improves performance for the two applications considered, namely Information Retrieval and Text Categorization.M.S.Includes bibliographical references (p. 80-83)
Evaluation of UML based wireless network virtualization
No full textVirtualization of wireless networks is recognized to be a difficult problem due to the fact that radios interact with their neighbors at various layers of the protocol stack, making strict isolation of virtual networks ("or slices") quite challenging. The goal of virtualization is to support concurrent experiments, both long-running services as well as short-term experiments on shared wireless network. In a wireless network, the radio resources that can be shared and hence virtualized are in time, space and frequency. Efforts have been going on to modify the ORBIT control structure to accommodate different forms of virtualization including VMAC, SDMA, FDMA and TDMA. Among different possible wireless virtualization techniques, this work is focused on allowing a node to run more than one experiment simultaneously using different frequencies i.e. Frequency Division Multiplexing (FDM). Each node in the ORBIT test bed is provided with two physical wireless cards. FDMA virtualization is achieved by running two concurrent User Level Operating Systems (ULOS) on each node and providing each operating system access to a radio card. Thus an experimental end user would view a single node as two virtual nodes, each equipped with one wireless card.
Experimental results are provided to compare the performance of a virtualized radio node with the non virtualized one for basic point-to-point experiments using TCP and UDP. Bounds on performance metrics of throughput, delay and jitter are determined and cross-coupling effects between two virtualized experiments are examined. We also look at transient behavior associated with sudden changes in traffic on one of the virtual networks. Finally, the uncertainty in performance measurements for a few typical usage scenarios is investigated, leading to guidelines for use of virtualized radio nodes for simultaneous ORBIT experiments.M.S.Includes bibliographical references (p. 44-45)
Microstructural characterisation by X-ray scattering of perovskite-type La0.8Sr0.2MnO3±d thin films prepared by a dip-coating process
No full textThe La0.8Sr0.2MnO3 (LSM) cathode materials are widely used in solid oxide fuel cells (SOFCs) as electronic conductors. In such materials, the reduction of oxygen is located at the triple contact boundaries: air/cathode LSM/electrolyte which is generally Yttria Stabilised Zirconia (YSZ). In order to improve the chemical reactions at these air/cathode LSM/electrolyte interfaces, the triple phase boundary length has to be optimised. In this aim, we have first synthesised the La0.8Sr0.2MnO3 phase by a sol–gel route and, second, LSM thin films have been deposited on various polished substrates by using a dip-coating process. The structure and microstructure of the resulting LSM thin layers have been investigated by using well suited complementary techniques such as X-ray reflectometry, grazing incidence small angle X-ray scattering, Xray diffraction and scanning electronic microscopy. The structural and microstructural parameters of LSM thin films have been managed and studied as a function of synthesis parameters such as initial metallic salt concentration, time and temperature of annealing. The higher the metallic salt concentration, the higher the thickness of the film, the smaller the film density.The as-prepared layers are amorphous and the single crystallised perovskite form is obtained for low temperature heat treatments. Therefore, the annealed coatings are constituted by randomly oriented LSM nanocrystals, which organise in a more or less dense close-packed microstructure according to the initial metallic salt concentration
Polarised XAS study of anomalous temperature dependence of aggregation of itinerant holes and pair formation in a YBa2Cu3O7-d single crystal
No full textA polarised X-ray absorption study is made on an underdoped YBCO substantially detwinned single crystal to study the anomalous temperature dependence of itinerant holes, charge aggregation and pair formation along the E∥b and E∥a directions. The measurements were made at the O K and Cu L3 edges varying the temperature from 10 K to room temperature (∼300 K) using a liquid helium cryostat. In earlier reports on the YBCO reported observing the charge aggregation and the Cooper pair formation taking place only once each at temperatures and , both greater than Tc we observe these phenomena repeating themselves at two more temperatures, still in the normal state though. We have observed much smaller magnitude of the fluctuations of the itinerant holes in the ‘a’-direction as compared to ‘b’-direction in our experiment. Our results at T<40 K appear to go against the hypothesis that treats stripe formation essential to superconductivity in the cuprate perovskite systems
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