188 research outputs found
Generalized CAPTCHA with security applications
Get PDFThesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 51-53).A puzzle only solvable by humans, or POSH, is a prompt or question with three important properties: it can be generated by a computer, it can be answered consistently by a human, and a human answer cannot be efficiently predicted by a computer. In fact, a POSH does not necessarily have to be verifiable by a computer at all. One application of POSHes is a scheme proposed by Canetti et al. that limits on-line dictionary attacks against password-protected local storage, without the use of any secure hardware or secret storage. We explore the area of POSHes, implement several candidate POSHes and have users solve them, to evaluate their effectiveness. Given these data, we then implement the above scheme as an extension to the Mozilla Firefox web browser, where it is used to protect user certificates and saved passwords. In the course of doing so, we also define certain aspects of the threat model for our implementation (and the scheme) more precisely.by Waseem S. Daher.M.Eng
Influence of Batch Cooling Crystallization on Mannitol Physical Properties and Drug Dispersion from Dry Powder Inhalers
Get PDFThis study provides, for the first time, an evaluation of the physicochemical properties of batch cooling crystallized mannitol particles combined with how these properties correlated with the inhalation performance from a dry powder inhaler (Aerolizer). The results showed that the type of polymorph changed from β-form (commercial mannitol) to mixtures of β- + δ-mannitol (cooling crystallized mannitol crystals). In comparison to mannitol particles, crystallized at a higher supersaturation degree, a lower degree of supersaturation favored the formation of mannitol crystals with a more regular and elongated habit, smoother surface, higher specific surface area, higher fine particle content, higher bulk density, and higher tap density. Cooling crystallized mannitol particles demonstrated considerably lower salbutamol sulfate–mannitol adhesion in comparison to commercial mannitol, with a linear reduction as surface roughness decreased and fines content increased. Also, mannitol crystals with smoother surfaces demonstrated a reduction in salbutamol sulfate content uniformity (expressed as %CV) within salbutamol sulfate–mannitol formulations. Despite the different physical properties, all mannitol products showed similar flow properties and similar emission of salbutamol sulfate upon inhalation. However, mannitol crystals grown from lower supersaturation (reduced roughness and increased fines) generated a finer aerodynamic size distribution and consequently deposited higher amounts of salbutamol sulfate on lower stages of the impactor. Regression analysis indicated linear relationships showing higher fine particle fraction of salbutamol sulfate in the case of mannitol particles having a more elongated shape, higher fines content, higher specific surface area, higher bulk density, and higher tap density. In conclusion, a cooling crystallization technique could be controlled to produce mannitol particles with controlled physical properties that could be used to influence aerosolization performance of a dry powder inhaler product
Proximal Hamstring tendinopathy treatment with Autologous Blood Injections: A one year follow up study assessing pain relief and functional improvement.
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A SYSTEMATIC REVIEW OF ENTREPRENEURIAL LEADERSHIP: Muhammad Atif Bashir, Shakeel Sarwar, Muhammad Rizwan, Waseem Ahmad Khan
No full textThis study outlines an inclusive review of past studies on “entrepreneurial leadership (EL)”. A systematic literature review (SLTR) is an accredited approach for producing the trustworthy understandings from an evidence based technique. The approach of SLTR used in this study is conducted stepwise for providing the support to conceptual development of EL. The review method of this research conduct begins with keywords’ identification collected from the panel of review. These search strings were then utilized in nine databases that were considered as highly suitable for the research in management field. These databases include: Emerald, JSTOR, Sage journals, Science direct, Springer link, Taylor and Francis, Web of Knowledge, and Wiley online library. To obtain the relevant articles, titles and abstracts were screened out based on exclusion and inclusion criteria. The references and citations of chosen papers were scrutinized to decide their exclusion and inclusion. Initially, 216 articles in total were recognized that were further refined in the process of review. Duplicate papers chosen from given databases were then filtered out. In the end, the study has selected 97 papers that were suitable for the review and analysis. The findings of this paper sustenance the conclusion that EL is an important determinant that enhances organizational performance across competitive and turbulent atmospheres. Though, what is indistinct is the magnitude to which the EL attributes recognized are pertinent in a specific context. The research results highlight the manifold attributes relevant to EL like vision, risk-taking, effective communication, creativity and innovativeness. It has been seen that while the SLTR procedures came up with a exhaustive review of the past studies on EL, the effectiveness of the literatures is restricted to the search specific sentence strings used in the databases. Based on the SLTR, recommendations and future suggestions with specific reference to emerging countries are propose
Compaction performance analysis of alum sludge waste modified soil
No full textSustainable construction is one of the ultimate requirements of the engineering field. Addition of waste materials not only contribute to the improvement of the density of soils but also help in the enhancement of its strength properties. In the field, compaction is achieved by compactors and rollers, which consumes a lot of energy for this purpose. In this study, two methods related to compaction energy have been applied to study the relation of compaction energy with the strength of soil before and after addition of alum sludge as a soil stabilizer. An advanced Artificial Neural Networks (ANN5) technique has been applied with reference to the addition of alum sludge percentage, plasticity index, specific gravity, optimum moisture content, maximum dry density, AASHTO classification, USCS classification, and group index. It was found that soil strength can be improved even at a low compaction energy level of 600KN-m/m(3) by the addition of optimum percentage of 8% alum sludge as a soil stabilizer. So, roller compaction effort can also be reduced by addition of this soil stabilizer to save compaction cost i.e. saving of roller fuel consumption and rental cost as well. This study will not only help in environment-friendly construction but will also manage finance by utilization of optimum compaction energy in the mega projects.Shah, SAR (reprint author), Pakistan Inst Engn & Technol, Dept Civil Engn, Khanewal Rd, Multan 60000, Pakistan.
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Particle Ratios in a Multicomponent Nonideal Hadron Resonance Gas
No full textWe have considered formation of a multicomponent nonideal hot and dense gas of hadronic resonances in the ultrarelativistic heavy ion collisions. In the statistical thermal model approach, the equation of state (EoS) of the noninteracting ideal hadron resonance gas (IHRG) does not incorporate either the attractive part or the short-range repulsive part of the baryonic interaction. On the other hand, in the nonideal hadron resonance gas (NIHRG) model, we can incorporate these interactions using the van der Waals (VDW) type approach. Studies have been made to see its effect on the critical parameters of the quark-hadron phase transition. However, it can also lead to modifications in the calculated relative particle yields. In this paper, we have attempted to understand the effect of such van der Waals-type interactions on the relative particle yields and also studied their dependences on the system’s thermal parameters, such as the temperature and baryon chemical potential μB. We have also taken into account the decay contributions of the heavier resonances. These results on particle ratios are compared with the corresponding results obtained from the point-like, i.e., noninteracting IHRG model. It is found that the particle ratios get modified by incorporating the van der Waals-type interactions, especially in a baryon-rich system which is expected to be formed at lower RHIC energies, SPS energies, and in the forthcoming CBM experiments due to high degree of nuclear stopping in these experiments
Using TF-IDF n-gram and word embedding cluster ensembles for author profiling: Notebook for PAN at CLEF 2017
Get PDFThis paper presents our approach and results for the 2017 PAN Author Profiling Shared Task. Language-specific corpora were provided for four langauges: Spanish, English, Portuguese, and Arabic. Each corpus consisted of tweets authored by a number of Twitter users labeled with their gender and the specific variant of their language which was used in the documents (e.g. Brazilian or European Portuguese). The task was to develop a system to infer the same attributes for unseen Twitter users. Our system employs an ensemble of two probabilistic classifiers: a Logistic regression classifier trained on TF-IDF transformed n-grams and a Gaussian Process classifier trained on word embedding clusters derived for an additional, external corpus of tweets
Synthesis and applications of electrospun nanofibers /
No full textSynthesis and Applications of Electrospun Nanofibers examines processing techniques for nanofibers and their applications in a variety of industry sectors, including energy, agriculture and biomedicine. The book gives readers a thorough understanding of both electrospinning and interfacial polymerization techniques for their production. In addition, the book explore the use of nanofibers in a variety of industry sectors, with particular attention given to nanofibers in medicine, such as in drug and gene delivery, artificial blood vessels, artificial organs and medical facemasks, and in energy and environmental applications. Specific topics of note include fuel cells, lithium ion batteries, solar cells, supercapacitors, energy storage materials, sensors, filtration materials, protective clothing, catalysis and electromagnetic shielding. This book will serve as an important reference resource for materials scientists, engineers and biomedical scientists who want to learn more on the uses of nanofibers.Includes bibliographical references and index.Online resource; title from PDF title page (EBSCO, Oct. 18, 2018).Synthesis and Applications of Electrospun Nanofibers examines processing techniques for nanofibers and their applications in a variety of industry sectors, including energy, agriculture and biomedicine. The book gives readers a thorough understanding of both electrospinning and interfacial polymerization techniques for their production. In addition, the book explore the use of nanofibers in a variety of industry sectors, with particular attention given to nanofibers in medicine, such as in drug and gene delivery, artificial blood vessels, artificial organs and medical facemasks, and in energy and environmental applications. Specific topics of note include fuel cells, lithium ion batteries, solar cells, supercapacitors, energy storage materials, sensors, filtration materials, protective clothing, catalysis and electromagnetic shielding. This book will serve as an important reference resource for materials scientists, engineers and biomedical scientists who want to learn more on the uses of nanofibers.Elsevie
ACC-deaminase and/or nitrogen-fixing rhizobacteria and growth response of tomato (Lycopersicon pimpinellfolium Mill.)
Get PDFThe study aimed to identify and select important plant growth-promoting
rhizobacteria (PGPR) and examine the response of tomato growth upon
inoculation. Inoculation with rhizobacterial isolates increased all the
measured physical, chemical, and enzymatic growth parameters compared to
control. However, the TAN1 isolate had the highest effect, and significantly
(P < 0.05) increased the root length (8.25-fold), root fresh (8.36-fold) and
dry (12.6-fold) weight, shoot length (6.92-fold), shoot fresh (7.18-fold) and
dry (6.90-fold) weight, number of leaves (11.0-fold), chlorophyll a
(6.25-fold), chlorophyll b (10.7-fold), carotenoid contents (8.80-fold),
seedlings fresh (9.0-fold) and dry (8.71-fold) weight, plant macronutrient
uptake, i.e. N (7.7- and 8.9-fold), P (10.5- and 11.4-fold), K (7.8- and
8.8-fold), Ca (12.7- and 8.2-fold), and Mg (12.6- and 9-fold) in shoot and
root, plant micronutrient uptake, i.e. Zn (6.6-, 10.2-), Cu (9.3-, and
10.3-fold), Fe (7.7- and 10.7-fold), and Mn (4.7- and 5.7-fold) in shoot and
root and plant antioxidant enzymes, i.e. glutathione S-transferase
(10.7-fold), peroxidase (8.1-fold), and catalase (10.5-fold). Our results
concluded that inoculation of agricultural crops with rhizobacteria is a very
useful approach to increase the plant growth. The rhizobacteria having both
1-aminocyclopropane-1-carboxylate (ACC) deaminase and nitrogen-fixing activity
are more effective than rhizobacteria possessing either ACC-deaminase or
nitrogen-fixing activity alone for growth promotion of crops
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