Securing Downlink Massive MIMO-NOMA Networks with Artificial Noise

In this paper, we focus on securing the confidential information of massive multiple-input multiple-output (MIMO) non-orthogonal multiple access (NOMA) networks by exploiting artificial noise (AN). An uplink training scheme is first proposed with minimum mean squared error estimation at the base station. Based on the estimated channel state information, the base station precodes the confidential information and injects the AN. Following this, the ergodic secrecy rate is derived for downlink transmission. An asymptotic secrecy performance analysis is also carried out for a large number of transmit antennas and high transmit power at the base station, respectively, to highlight the effects of key parameters on the secrecy performance of the considered system. Based on the derived ergodic secrecy rate, we propose the joint power allocation of the uplink training phase and downlink transmission phase to maximize the sum secrecy rates of the system. Besides, from the perspective of security, another optimization algorithm is proposed to maximize the energy efficiency. The results show that the combination of massive MIMO technique and AN greatly benefits NOMA networks in term of the secrecy performance. In addition, the effects of the uplink training phase and clustering process on the secrecy performance are revealed. Besides, the proposed optimization algorithms are compared with other baseline algorithms through simulations, and their superiority is validated. Finally, it is shown that the proposed system outperforms the conventional massive MIMO orthogonal multiple access in terms of the secrecy performance

Contextualizing substance use genetic risk using single-nucleus RNA-sequencing of the reward circuitry of the human brain

Novel single-cell technologies have afforded the generation of a vast amount of genomics data, including full-genome and -transcriptome sequencing, features of epigenetic and chromatin organization, and proteomics, all at the single-cell level. These new insights into human biology at such deep resolution have only begun to shed new light on tissue development and organization, as well as disease etiology, including in complex disorders or phenotypes of the human brain. Psychiatric genomics is one field exhibiting such progress in the unraveling of the complex genetics and molecular consequences underlying various neuropsychiatric disorders, whereas phenotypes characterized by other cognitive behaviors such as substance use and addiction, are yet to be understood at the cell-type-specific genetic level. In this work, I describe efforts to understand the complex transcriptomic architecture of cell populations within the reward circuitry in the human brain and demonstrate the utility of leveraging genomic association data to understand which of these cell populations identified genetic risk loci may be uniquely affecting. Using single-nucleus RNA-sequencing (snRNA-seq), we profiled the single-nucleus-level transcriptomes of five regions embedded in the reward circuitry, including the nucleus accumbens, amygdala, hippocampus, subgenual anterior cingulate cortex, and dorsolateral prefrontal cortex. From this work, we characterized the transcriptomes of 107 robust cell classes at the region-specific level and performed cross-species analyses with existing data in rodent models, to assess the degree of convergence or divergence these established cell types ii share with their corresponding rodent brain regions. Finally, we quantified genetic risk associations for five substance use phenotypes in each of the 107 cell profiles, identifying unique dopaminoceptive subpopulations in the nucleus accumbens that may be susceptible to genetic risk for increased levels of smoking. This work contributes substantially to the field of reward cognition and demonstrates the utility of integrating single-cell transcriptomics and population genomics

An efficient numerical procedure for calculating periodic vibrations of elastic mechanisms

This paper proposes a numerical procedure based on the well-known Newmark integration method to determine initial conditions for the periodic solution of a system of linear differential equations with time-periodic coefficients. Based on this, steady-state periodic vibrations of mechanisms with elastic elements governed by linearized differential equations with time-periodic coefficients can be conveniently calculated. The proposed procedure is demonstrated by a dynamic model of a planar four-bar mechanism with the flexible coupler

Impact of primary networks on the performance of energy harvesting cognitive radio networks

In this paper, we investigate the effect of of the primary network on the secondary network when harvesting energy in cognitive radio in the presence of multiple power beacons and multiple secondary transmitters. In particular, the influence of the primary transmitter’s transmit power on the energy harvesting secondary network is examined by studying two scenarios of primary transmitter’s location, i.e., the primary transmitter’s location is near to the secondary network and the primary transmitter’s location is far from the secondary network. In the scenario where the primary transmitter locates near to the secondary network, although secondary transmitter can be benefit from the harvested energy from the primary transmitter, the interference caused by the primary transmitter suppresses the secondary network performance. Meanwhile, in both scenarios, despite the fact that the transmit power of the secondary transmitter can be improved by the support of powerful power beacons, the peak interference constraint at the primary receiver limits this advantage. In addition, the deployment of multiple power beacons and multiple secondary transmitters can improve the performance of the secondary network. The analytical expressions of the outage probability of the secondary network in the two scenarios are also provided and verified by numerical simulations

DEWATS dissemination in Vietnam: achievements and lessons learnt

The speedy economic development and rapid growth of population and urbanization in Vietnam have created great pressure on the environment by its manufacturing process and human activities. Thus, it is necessary to protect the environment through policies and appropriate technology for the sustainable development of the country. The DEcentralized WAstewater Treatment Solutions (DEWATS) dissemination in Vietnam is one of the measures contributing to address this issue

Inverse kinematic and dynamic analysis of redundant measuring manipulator BKHN-MCX-04

This paper deals with the problem of inverse kinematics and dynamics of a measuring manipulator with kinematic redundancy which was designed and manufactured at Hanoi University of Technology for measuring the geometric tolerance of surfaces of machining components. A comparison between the calculation result and the experimental measurement is also presented

The Role of Anisotropy in Distinguishing Domination of Néel or Brownian Relaxation Contribution to Magnetic Inductive Heating: Orientations for Biomedical Applications

Magnetic inductive heating (MIH) has been a topic of great interest because of its potential applications, especially in biomedicine. In this paper, the parameters characteristic for magnetic inductive heating power including maximum specific loss power (SLPmax), optimal nanoparticle diameter (Dc) and its width (ΔDc) are considered as being dependent on magnetic nanoparticle anisotropy (K). The calculated results suggest 3 different Néel-domination (N), overlapped Néel/Brownian (NB), and Brownian-domination (B) regions. The transition from NB- to B-region changes abruptly around critical anisotropy Kc. For magnetic nanoparticles with low K (K Kc) are opposite. The decreases of the SLPmax when increasing polydispersity and viscosity are characterized by different rates of d(SLPmax)/dσ and d(SLPmax)/dη depending on each domination region. The critical anisotropy Kc varies with the frequency of an alternating magnetic field. A possibility to improve heating power via increasing anisotropy is analyzed and deduced for Fe3O4 magnetic nanoparticles. For MIH application, the monodispersity requirement for magnetic nanoparticles in the B-region is less stringent, while materials in the N- and/or NB-regions are much more favorable in high viscous media. Experimental results on viscosity dependence of SLP for CoFe2O4 and MnFe2O4 ferrofluids are in good agreement with the calculations. These results indicated that magnetic nanoparticles in the N- and/or NB-regions are in general better for application in elevated viscosity media

Cognitive full-duplex relay networks under the peak interference power constraint of multiple primary users

Abstract This paper investigates the outage performance of cognitive spectrum-sharing multi-relay networks in which the relays operate in a full-duplex (FD) mode and employ the decode-and-forward (DF) protocol. Two relay selection schemes, i.e., partial relay selection (PRS) and optimal relay selection (ORS), are considered to enhance the system performance. New exact expressions for the outage probability (OP) in both schemes are derived based on which an asymptotic analysis is carried out. The results show that the ORS strategy outperforms PRS in terms of OP, and increasing the number of FD relays can significantly improve the system performance. Moreover, novel analytical results provide additional insights for system design. In particular, from the viewpoint of FD concept, the primary network parameters (i.e., peak interference at the primary receivers, number of primary receivers, and their locations) should be carefully considered since they significantly affect the secondary network performance

NGHIÊN CỨU XÂY DỰNG HỆ THỐNG HỖ TRỢ HÀNH CHÍNH TRỰC TUYẾN CHO SINH VIÊN TẠI TRƯỜNG ĐẠI HỌC NGOẠI NGỮ, ĐẠI HỌC HUẾ

Hệ thống hỗ trợ hành chính công trực tuyến là nơi tiếp nhận và xử lý đơn, xác nhận hành chính và các nhu cầu có liên quan của người học. Thời kỳ chuyển đổi số ngày nay đã tạo điều kiện thuận lợi để cải tiến công tác hành chính giúp người học đơn giản hóa thủ tục, đáp ứng nhanh các yêu cầu, số hóa một số quy trình và tư liệu hành chính của cơ sở giáo dục. Trong nghiên cứu này, chúng tôi xây dựng và thử nghiệm hệ thống hỗ trợ công tác hành chính công trực tuyến, qua đó khâu tiếp nhận yêu cầu từ người học và trả kết quả được tiến hành hoàn toàn trực tuyến. Hệ thống được triển khai trên giao diện web là trang Thông tin Đào tạo đại học của Trường Đại học Ngoại ngữ, Đại học Huế. Trên trang này, chúng tôi công khai các biểu mẫu hành chính, tiếp nhận các yêu cầu và xử lý, chuyển trả kết quả qua mạng. Bằng cách cho sinh viên sử dụng hệ thống và khảo sát người dùng để đánh giá, từ đó chúng tôi có căn cứ để đề xuất, điều chỉnh và đưa hệ thống vào ứng dụng thực tế với mục đích mang lại dịch vụ công tốt hơn cho người họ

EFL Agreeing and Disagreeing Discourses in Facebook

Agreeing and disagreeing are two common speech acts that occur in social conversations. Driven by the fact that there are direct and indirect way for expressing agreement and disagreement, and there are also mitigating strategies to protect interlocutors from face-threatening in disagreeing discourses, this study examined EFL students’ use of discourse strategies in their Facebook interaction. Thirty-four pre-intermediate EFL students at a university in Vietnam took part in this study. Data analysis shows that direct discourses is linguistically limited while indirect ones exhibit wider language use. Students also demonstrate two different directions of using mitigating strategies for their disagreeing discourses. Some pedagogical implications are also suggested in this study. Keywords: agreeing, disagreeing, direct, indirect, strategies DOI: 10.7176/JLLL/86-03 Publication date: February 28th 202