1,021 research outputs found
catena-Poly[[bis(2-aminoethanesulfonato-κ2 N,O)nickel(II)]-μ-1,4-bis(1H-imidazol-1-yl)benzene-κ2 N 3:N 3′]
In the hydrothermally prepared title coordination polymer, [Ni(C2H6NO3S)2(C12H10N4)]n, the NiII ion and the 1,4-bis(1H-imidazol-1-yl)benzene ligand occupy special positions on inversion centers. The metal ion shows a slightly distorted octahedral coordination geometry, being linked to two N atoms of two 1,4-bis(imidazol-1-yl)benzene ligands and to two O and two N atoms of two chelating 2-aminoethanesulfonate ligands. The 1,4-bis(imidazol-1-yl)benzene ligands bridge symmetry-related NiII ions forming polymeric chains along the [110] direction
Method for Measurement of Single-Injector Heat Transfer Characteristics and Its Application in Studying Gas-Gas Injector Combustion Chamber
Assessment of the key aroma compounds in rose-based products
AbstractIn this study, headspace solid phase microextraction–gas chromatography-mass spectrometry and GC-olfactometry were used to analyze the key aroma compounds in three types of rose-based products, including low-temperature extracts (LTEs), high-temperature extracts (HTEs), and rose drinks (RDs). In combination with the Guadagni theory, it was confirmed that the key aroma components of LTE were β-phenyl ethyl alcohol, citronellol, geraniol, and eugenol. The main aroma compounds in HTE were β-phenyl ethyl alcohol, citronellol, geraniol, eugenol, linalool, and rose oxide. The four key aroma compounds in RDs were β-phenyl ethyl alcohol, eugenol, geraniol, and linalool
Secure Transmission Design for Cognitive Radio Networks With Poisson Distributed Eavesdroppers
In this paper, we study physical layer security
in an underlay cognitive radio (CR) network. We consider
the problem of secure communication between a secondary
transmitter-receiver pair in the presence of randomly distributed
eavesdroppers under an interference constraint set by the primary
user. For different channel knowledge assumptions at the
transmitter, we design four transmission protocols to achieve the
secure transmission in the CR network. We give a comprehensive
performance analysis for each protocol in terms of transmission
delay, security, reliability, and the overall secrecy throughput.
Furthermore, we determine the optimal design parameter for
each transmission protocol by solving the optimization problem
of maximizing the secrecy throughput subject to both security
and reliability constraints. Numerical results illustrate the performance
comparison between different transmission protocols.ARC Discovery Projects Grant DP15010390
A Triangular Personalized Recommendation Algorithm for Improving Diversity
Recommendation systems are used when searching online databases. As such they are very important tools because they provide users with predictions of the outcomes of different potential choices and help users to avoid information overload. They can be used on e-commerce websites and have attracted considerable attention in the scientific community. To date, many personalized recommendation algorithms have aimed to improve recommendation accuracy from the perspective of vertex similarities, such as collaborative filtering and mass diffusion. However, diversity is also an important evaluation index in the recommendation algorithm. In order to study both the accuracy and diversity of a recommendation algorithm at the same time, this study introduced a “third dimension” to the commonly used user/product two-dimensional recommendation, and a recommendation algorithm is proposed that is based on a triangular area (TR algorithm). The proposed algorithm combines the Markov chain and collaborative filtering method to make recommendations for users by building a triangle model, making use of the triangulated area. Additionally, recommendation algorithms based on a triangulated area are parameter-free and are more suitable for applications in real environments. Furthermore, the experimental results showed that the TR algorithm had better performance on diversity and novelty for real datasets of MovieLens-100K and MovieLens-1M than did the other benchmark methods
Protecting cognitive radio networks against poisson distributed eavesdroppers
In this paper, we study secure transmission designs for underlay cognitive radio networks in the present of randomly distributed eavesdroppers. We consider the scenario where a secondary transmitter sends confidential messages to a secondary receiver subject to an interference constraint set by the primary user. We design two transmission protocols under different channel knowledge assumptions at the transmitter. For each protocol, we first give a comprehensive performance analysis to investigate the transmission delay, secrecy, and reliability performance. We then optimize the transmission design for maximizing the secrecy throughput subject to both secrecy and reliability constraints. Finally, we numerically compare the performance of the two transmission protocols.ARC Discovery Projects Grant DP15010390
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