In this paper, two new practical attacks on some secret sharing-based data outsourcing schemes are first introduced, and several other security and performance issues with the existing schemes are also explored. The existing and new attacks exploit the information about the share range boundaries or the correspondences between the secret values and shares. A range expansion technique is then proposed to thwart one of the attacks. It expands the ranges in every range predicate in the submitted queries in order to hide the share range boundaries from any query observer. Next, a mapping method is proposed to thwart the other attacks. It maps each secret value to a mapping value using a secret one-to-many mapping with a finite set of linear mapping rules so that the tuples of shares are generated from the mapping values rather than directly from the secret values. The proposed mapping method works as an additional layer of security and addresses any attack based on the correspondences between the secret values and shares. At the same time, it preserves the homomorphism property of secret sharing. Finally, a new secure data outsourcing scheme is elaborated on secret sharing, the proposed mapping method, and the proposed range expansion technique. The proposed scheme is resistant to various attacks and also some inferences. It supports the fully server-side or a partially server-side query execution of most types of queries. The experimental results confirm that the proposed scheme is quite practical and efficient.
The process of disease awareness distribution on the web was studied. The contribution of WHO world awareness days to the total awareness process over the internet was investigated.
Methods
A system dynamics model for disease awareness distribution process online was proposed. The model results were compared to empirical data from Google Trends. The data were utilized to examine the number of disease-related search queries which have world awareness days dedicated to them. Among these diseases, online queries for AIDS, tuberculosis, breast cancer and autism depicted considerable increases during the world awareness dates, which were used to calibrate the model.
Results
Awareness distribution process for AIDS and tuberculosis as contagious diseases, were much faster than the other two non-contagious diseases. The information sharing process for these diseases was so fast that a sudden fall in the number of search queries was observable in a few years.
Conclusions
Our results illustrate that for contagious diseases, the WHO program was most effective in initiating the awareness process, while for non-contagious ones it had a consistent influence throughout. 相似文献
Hemodialysis catheters are associated with higher risks of complications compared to arteriovenous fistulas and grafts. Some common complications of dialysis catheters include infection, thrombus formation, central venous stenosis, and mechanical dysfunction. Rarely, catheters can become firmly adhered to a vessel wall. Catheter adhesion is a serious complication that can impact the delivery of safe and effective dialysis to affected patients. Adherent catheters commonly present insidiously with no overt diagnostic signs and symptoms or antecedent catheter malfunction. Prognosis is variable, but can be potentially fatal depending on the severity of adhesion, and sequelae of complications. There are no standardized methods of therapy and treatment strategies are anecdotally reported by interventional radiology, vascular, and cardiothoracic surgery. We hereby describe a case of hemodialysis catheter that has become firmly embedded within the superior vena cava wall. We review the available literature on the epidemiology, risk factors, long‐term sequelae, and known management strategies of adherent catheters. The development of preventative measures will be of great importance given serious complications and limited treatment options. Clinical awareness and understanding of this rare condition is imperative to the prevention and management of adherent catheters. 相似文献
Patenting and licensing is not only a significant method of university knowledge transfer, but also an important indicator
for measuring academic R&D strength and knowledge utilization. The methodologies of quantitative and qualitative analysis,
including a special patent h-index indicator to assess patenting quality, were used to examine university patenting worldwide. Analysis of university
patenting from 1998 to 2008 showed a significant overall global increase in which Chinese academia stands out: most of the
top 20 universities in patenting in 2008 were in China. However, a low rate of utilization of Chinese academic patents may
have roots in: (1) university research evaluation system encourages the patent production more, rather than the utilization;
(2) problems in the formal mechanisms for university technology transfer and licensing, (3) industry’s limited expectation
and receptive capabilities and/or (4) a mismatch between the interests of the two institutional spheres. The next action to
be taken by government, university and industry in China will be to explore strategies for improving academic patent quality
and industry take-up. 相似文献
Smooth torque production by induction machines is an improbable phenomena that is taken into account only in classic and ideal studying methods. In this research, slot numbering and also non-sinusoidal winding function effects are studied for a three-phase wound-rotor induction machine, which is addressed for the first time, and a new formula is introduced for calculating the spectral components of machine torque and current. To reach this aim, mathematical modeling of the air-gap function is proposed, and a discrete time modeling of the machine is introduced to study the effects of space harmonics on the torque/current spectral. To study the mentioned phenomena, in the first part, the winding functions are considered as ideally sinusoidal and the behavior of simulated machines is investigated based on the winding function approach and numerical method analysis. Two certain formulas are introduced for the spectral components of torque ripple and stator currents according to the slot numbers, rotor speed, and number of machine poles. In the second part, slot opening effects are neglected and non-sinusoidal windings are considered for obtaining the same results. Finally, considering both effects, model validation is confirmed by a finite-element-based method, and the introduced method is proven. 相似文献