1,950 research outputs found
Engineering Standards: An Introduction for Electrical and Computer Engineering Students
Engineering standards are summaries of industrial best practices. The specifications are written in terms of functional, mechanical and electrical aspects that allow proper usage of available components to build a system. Standards may also be regarded as codified guidelines that define how tests should be performed, and how products are to be designed. Standards are created by bringing together experience and expertise of stakeholders on specific issues. Standards protect public health and safety, improve product quality, help to advance the growth of new technologies, and foster international trade. It is important that students get familiar with standards while in school
PHOABE : securely outsourcing multi-authority attribute based encryption with policy hidden for cloud assisted IoT
Attribute based encryption (ABE) is an encrypted access control mechanism that ensures efficient data sharing among dynamic group of users. Nevertheless, this encryption technique presents two main drawbacks, namely high decryption cost and publicly shared access policies, thus leading to possible users’ privacy leakage.
In this paper, we introduce PHOABE, a Policy-Hidden Outsourced ABE scheme. Our construction presents several advantages. First, it is a multi-attribute authority ABE scheme. Second, the expensive computations for the ABE decryption process is partially delegated to a Semi Trusted Cloud Server. Third, users’ privacy is protected thanks to a hidden access policy. Fourth, PHOABE is proven to be selectively secure, verifiable and policy privacy preserving under the random oracle model. Five, estimation of the processing overhead proves its feasibility in IoT constrained environments
Constant-size threshold attribute based SignCryption for cloud applications
In this paper, we propose a novel constant-size threshold attribute-based signcryption scheme for securely
sharing data through public clouds. Our proposal has several advantages. First, it provides flexible cryptographic access control, while preserving users’ privacy as the identifying information for satisfying the access
control policy are not revealed. Second, the proposed scheme guarantees both data origin authentication and
anonymity thanks to the novel use of attribute based signcryption mechanism, while ensuring the unlinkability
between the different access sessions. Third, the proposed signcryption scheme has efficient computation cost
and constant communication overhead whatever the number of involved attributes. Finally, our scheme satisfies strong security properties in the random oracle model, namely Indistinguishability against the Adaptive
Chosen Ciphertext Attacks (IND-CCA2), Existential Unforgeability against Chosen Message Attacks (EUFCMA) and privacy preservation of the attributes involved in the signcryption process, based on the assumption
that the augmented Multi-Sequence of Exponents Decisional Diffie-Hellman (aMSE-DDH) problem and the
Computational Diffie Hellman Assumption (CDH) are hard
PAbAC : a privacy preserving attribute based framework for fine grained access control in clouds
Several existing access control solutions mainly focus on preserving confidentiality of stored data from unauthorized access and the storage provider. Moreover, to keep sensitive user data confidential against untrusted
servers, existing solutions usually apply cryptographic methods by disclosing data decryption keys only to authorized users. However, these solutions inevitably introduce a heavy computation overhead on the data owner
for key distribution and data management when fine-grained data access control is desired. In addition, access
control policies as well as users’ access patterns are also considered as sensitive information that should be
protected from the cloud. In this paper, we propose PAbAC, a novel privacy preserving Attribute-based framework, that combines attribute-based encryption and attribute-based signature mechanisms for securely sharing
outsourced data via the public cloud. Our proposal is multifold. First, it ensures fine-grained cryptographic access control enforced at the data owner’s side, while providing the desired expressiveness of the access control
policies. Second, PAbAC preserves users’ privacy, while hiding any identifying information used to satisfy
the access control. Third, PAbAC is proven to be highly scalable and efficient for sharing outsourced data in
remote servers, at both the client and the cloud provider side
Ramadan fasting influences on food intake consumption, sleep schedule, body weight and some plasma parameters in healthy fasting volunteers
This study examines the changes in the lifestyle that accompanied Ramadan fasting. For this purpose, we followed the questionnaire programming meals, food consumption and sleep rhythm. We also followed changes in plasma biological parameters. The results show that daily energy consumption was not changed and neither was the body weight. Nevertheless, a decrease in fat mass was detected. Concerning plasma, we found a decrease in blood glucose from the 7th day of fasting. This effect was found also at the 21st day, accompanied by a reduction in insulin levels. Our results on plasma lipids showed a decrease in triglycerides with total cholesterol level unchanged. Furthermore, we noted an increased HDL-C against a decreased LDL-C fraction. Taken together, these results suggest that fasting may induce beneficial effects in blood lipid concentrations.Keywords: Ramadan fasting, food intake consumption, sleep schedule, body weight, plasma parameters, healthy fasting volunteersAfrican Journal of Biotechnology Vol. 12(21), pp. 3327-333
Studying the ultrasonic assisted transesterification of castor oil by using factorial design for optimization of biodiesel production
This work presents the biodiesel production from castor oil with methanol in presence of potassium hydroxide as catalyst at room temperature using ultrasonic bath. A factorial design of experiments and a central composite design have been used to evaluate the influence of operating conditions on biodiesel synthesis from inedible castor oil. The response chosen was viscosity while the variables studied were catalyst concentration and the methanol/vegetable oil molar ratio at room temperature in an ultrasonic bath. The methanol/vegetable oil molar ratio is the most important factor, having a negative influence on viscosity.The catalyst concentration has a small negative influence on viscosity and this is attributed to the presence of ultra-sonification. A second order model was obtained to predict the produced biodiesel viscosity. Within the experimental range studied the model matched the results from the experiments
A robust sequential hypothesis testing method for brake squeal localisation
This contribution deals with the in situ detection and localisation of brake squeal in an automobile. As brake squeal is emitted from regions known a priori, i.e., near the wheels, the localisation is treated as a hypothesis testing problem. Distributed microphone arrays, situated under the automobile, are used to capture the directional properties of the sound field generated by a squealing brake. The spatial characteristics of the sampled sound field is then used to formulate the hypothesis tests. However, in contrast to standard hypothesis testing approaches of this kind, the propagation environment is complex and time-varying. Coupled with inaccuracies in the knowledge of the sensor and source positions as well as sensor gain mismatches, modelling the sound field is difficult and standard approaches fail in this case. A previously proposed approach implicitly tried to account for such incomplete system knowledge and was based on ad hoc likelihood formulations. The current paper builds upon this approach and proposes a second approach, based on more solid theoretical foundations, that can systematically account for the model uncertainties. Results from tests in a real setting show that the proposed approach is more consistent than the prior state-of-the-art. In both approaches, the tasks of detection and localisation are decoupled for complexity reasons. The localisation (hypothesis testing) is subject to a prior detection of brake squeal and identification of the squeal frequencies. The approaches used for the detection and identification of squeal frequencies are also presented. The paper, further, briefly addresses some practical issues related to array design and placement. (C) 2019 Author(s)
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