808 research outputs found
A Smart Approach for GPT Cryptosystem Based on Rank Codes
The concept of Public- key cryptosystem was innovated by McEliece's
cryptosystem. The public key cryptosystem based on rank codes was presented in
1991 by Gabidulin -Paramonov-Trejtakov(GPT). The use of rank codes in
cryptographic applications is advantageous since it is practically impossible
to utilize combinatoric decoding. This has enabled using public keys of a
smaller size. Respective structural attacks against this system were proposed
by Gibson and recently by Overbeck. Overbeck's attacks break many versions of
the GPT cryptosystem and are turned out to be either polynomial or exponential
depending on parameters of the cryptosystem. In this paper, we introduce a new
approach, called the Smart approach, which is based on a proper choice of the
distortion matrix X. The Smart approach allows for withstanding all known
attacks even if the column scrambler matrix P over the base field Fq.Comment: 5 pages. to appear in Proceedings of IEEE ISIT201
On improving security of GPT cryptosystems
The public key cryptosystem based on rank error correcting codes (the GPT
cryptosystem) was proposed in 1991. Use of rank codes in cryptographic
applications is advantageous since it is practically impossible to utilize
combinatoric decoding. This enabled using public keys of a smaller size.
Several attacks against this system were published, including Gibson's attacks
and more recently Overbeck's attacks. A few modifications were proposed
withstanding Gibson's attack but at least one of them was broken by the
stronger attacks by Overbeck. A tool to prevent Overbeck's attack is presented
in [12]. In this paper, we apply this approach to other variants of the GPT
cryptosystem.Comment: 5 pages. submitted ISIT 2009.Processed on IEEE ISIT201
FIXED POINT RESULTS IN COMPLEX VALUED METRIC SPACES WITH AN APPLICATION
In this paper, we introduce fixed point theorem for a general contractive condition in complex valued metric spaces. Also, some important corollaries under this contractive condition areobtained. As an application, we find a unique solution for Urysohn integral equations and some illustrative examples are given to support our obtaining results. Our results extend and generalize the results of Azam et al. [2] and some other known results in the literature
Nonlinear Spectral Unmixing using Semi-Supervised Standard Fuzzy Clustering
Coarse resolution captured in remote sensing causes the combination of different materials in one pixel, called the mixed pixel. Spectral unmixing estimates the combination of endmembers in mixed pixels and their corresponding abundance maps in the Hyper/Multi spectral image. In this paper, a nonlinear spectral unmixing based on semi-supervised fuzzy clustering is proposed. First, pure pixels (endmembers) using Vertex Component Analysis (VCA) are extracted and those pixels are the labelled pixels where the membership value of each is 1 for the corresponding endmember and 0 for the others. Second, the semi-supervised fuzzy clustering is applied to find the membership matrix defining the fraction of the endmember in each mixed pixel and hence extract the abundance maps. The experiments were conducted on both synthetic data such as the Legendre data and real data such as Jasper Ridge data. The non-linearity of the Legendre data was performed by the Fan model on different signal-tonoise ratio values. The results of the new unmixing model show its significant performance when compared with four state-of the art unmixing algorithm
Aladin, war and camera!
This audio documentary aims to show the journey of an Egyptian man who was a photojournalist for Reuters for 20 years of his life. Join Aladin Abdelnaby through his days as a photojournalist covering more than 5 wars and other significant events. Aladin Abdelnaby is an Egyptian photojournalism professor at The American University in Cairo. Aladin was a former photojournalist at Reuters for 20 years. In this audio feature, he discusses the events he reported and the impact his career had on his physical and mental health
An Integrated Framework for Staffing and Shift Scheduling in Hospitals
Over the years, one of the main concerns confronting hospital management is optimising the staffing and scheduling decisions. Consequences of inappropriate staffing can adversely impact on hospital performance, patient experience and staff satisfaction alike. A comprehensive review of literature (more than 1300 journal articles) is presented in a new taxonomy of three dimensions; problem contextualisation, solution approach, evaluation perspective and uncertainty. Utilising Operations Research methods, solutions can provide a positive contribution in underpinning staffing and scheduling decisions. However, there are still opportunities to integrate decision levels; incorporate practitioners view in solution architectures; consider staff behaviour impact, and offer comprehensive applied frameworks. Practitioners’ perspectives have been collated using an extensive exploratory study in Irish hospitals. A preliminary questionnaire has indicated the need of effective staffing and scheduling decisions before semi-structured interviews have taken place with twenty-five managers (fourteen Directors and eleven head nurses) across eleven major acute Irish hospitals (about 50% of healthcare service deliverers). Thematic analysis has produced five key themes; demand for care, staffing and scheduling issues, organisational aspects, management concern, and technology-enabled. In addition to other factors that can contribute to the problem such as coordination, environment complexity, understaffing, variability and lack of decision support. A multi-method approach including data analytics, modelling and simulation, machine learning, and optimisation has been employed in order to deliver adequate staffing and shift scheduling framework. A comprehensive portfolio of critical factors regarding patients, staff and hospitals are included in the decision. The framework was piloted in the Emergency Department of one of the leading and busiest university hospitals in Dublin (Tallaght Hospital). Solutions resulted from the framework (i.e. new shifts, staff workload balance, increased demands) have showed significant improvement in all key performance measures (e.g. patient waiting time, staff utilisation). Management team of the hospital endorsed the solution framework and are currently discussing enablers to implement the recommendation
PSYCHOLOGICAL AND PHYSIOLOGICAL EFFECTS OF INTEGRATING BUILDING ENVELOPES WITH PARAMETRIC PATTERNS IN OFFICE WORKERS
The building envelope has become an active element that allows the building to interact with the context of the surrounding environment. The integration of the envelope with architectural design patterns significantly affects the efficiency of the working environment space in the office buildings, where the resulting effect of this integration plays an important role in providing daylighting, visibility and view; which affects the comfort, performance and productivity of users in an office space. This research study aims to identify the physiological and psychological effects on office employees resulting from the integration of the building envelope and openings with one of the most important trends of contemporary architectural design and these are the parametric architecture and parametric patterns. The research sample includes 25 adult office workers (13 men and 12 women) of average age 34.5 ± 9.3years. Skin Conductance (SC) and Heart Rate (HR), were measured to assess physiological responses. Self-Assessment Manikin (SAM) and Short Form State-Trait Anxiety Inventory (SF- STAI) were used to determine psychological responses. The results showed a significant decrease in the mean heart rate values under Repetition and Recursion Pattern (FRA), and a significant decrease in the mean rate of Skin Conductance (SC) response under Repetition and Recursion Pattern (FRA) and Tiling and Subdivision Pattern (VOR) compared to the Baseline model. The study concluded that the influence of the parametric model to the state of valence and calm and reducing the negative feelings and anxiety situation of Office Workers compared to the Baseline model
Fatalism in Post-Revolution Egypt
Undergraduate Research Office Summer Research Fellowship4th Place Denman Undergraduate Research ForumFeatured in annual "Highlights of Undergraduate Research"Fatalism is the belief that forces outside of our control largely decide our future. It has traditionally been thought of as a single overarching idea. One recent study using the World Values Survey for the 2005-2010 wave found that social and religious fatalism are strongly correlated in most countries but not in others, including Egypt. This paper examines these two fatalisms in Egypt during the political opening created by the Egyptian revolution of 2011. Interviews were conducted with 136 adults in the months immediately following the June 17, 2012 Presidential election. In line with the WVS results, we found two unrelated dimension of fatalism: social and theological. The social correlates of these different dimensions are quite distinct, and each fatalism has different implications for political action. Social fatalism is associated with being older and female and is critical for willingness to engage in protest. Religious fatalism is negatively related to education and has no impact on protest potential. We conclude that fatalism has multiple dimensions that need to be separated to understand their origins and their implications for political action.Undergraduate Research OfficeA one year embargo was granted for this item.Academic Major: Neuroscienc
Topology optimization and rim design
A goal of this article is to show the development of the car wheel rims along with the progress of the manufacturing technologies over the past few years. To achieve this goal, topology optimization and generative design usage have been reviewed in this work. The research has focused on the main factors, which affect the life of car wheel rim, and it has shed the light on the effect of the topology optimization and the generative design on the manufacturing of the car wheel rims. Since the main factors above-mentioned are the: forces, material preferences and topology optimization, the study has covered the results of the studies made on each part along with the technology progress. Moreover, the article has explained the methodology main steps of the topology optimization and the generative design and their principles
Use of ANSYS Software for the Acetabular Cup Structure Analysis out of the Hip Implant
Modelling the hip implant has been one of the most important researches over the past few decades. In addition, using the ANSYS software for this purpose is well-known procedure to understand the real reaction of the hip implant parts during the daily life of the installed part. This study is to focus on the practical part of the use of ANSYS software to analyse the performance of the hip implant through the feature of structure analysis available in the ANSYS. The research applies the static loads behaviour only with the help of the static structural analysis to view the advantages and the disadvantages of every design, which helps us estimate the implant’s behaviour. The study investigates the optimization of the acetabular cup using the lattice optimization along with the infill option available in the ANSYS software in order to optimize the stress and the fixture of the cup inside the pelvis
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