42 results on '"Nan, Sha"'
Search Results
2. Hierarchical Q-Learning Based UAV Secure Communication against Multiple UAV Adaptive Eavesdroppers
- Author
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Jia Tu, Weiwei Yang, Jue Liu, Lianxin Yang, and Nan Sha
- Subjects
Technology ,Article Subject ,Computer Networks and Communications ,Computer science ,business.industry ,Q-learning ,020302 automobile design & engineering ,020206 networking & telecommunications ,Jamming ,Eavesdropping ,TK5101-6720 ,Data_CODINGANDINFORMATIONTHEORY ,02 engineering and technology ,0203 mechanical engineering ,Secure communication ,Telecommunication ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,business ,Information Systems ,Computer network - Abstract
In this paper, we investigate secure unmanned aerial vehicle (UAV) communication in the presence of multiple UAV adaptive eavesdroppers (AEs), where each AE can conduct eavesdropping or jamming adaptively by learning others’ actions for degrading the secrecy rate more seriously. The one-leader and multi-follower Stackelberg game is adopted to analyze the mutual interference among multiple AEs, and the optimal transmit powers are proven to exist under the existing conditions. Following that, a mixed-strategy Stackelberg Equilibrium based on finite and discretized power set is also derived and a hierarchical Q-learning based power allocation algorithm (HQLA) is proposed to obtain the optimal power allocation strategy of the transmitter. Numerical results show that secrecy performance can be degraded severely by multiple AEs and verify the availability of the optimal power allocation strategy. Finally, the effect of the eavesdropping cost on the AE’s attack mode strategies is also revealed.
- Published
- 2020
3. Secrecy Rate Optimization for RF Powered Two-Hop Untrusted Relay Networks with Non-Linear EH Model
- Author
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Nan Sha, Guozhen Zang, Yuanyuan Gao, Liu Xiaochen, and Kui Xu
- Subjects
business.industry ,Computer science ,Applied Mathematics ,Computer Graphics and Computer-Aided Design ,law.invention ,Hop (networking) ,Nonlinear system ,Relay ,law ,Signal Processing ,Secrecy ,Electrical and Electronic Engineering ,business ,Computer network - Published
- 2020
4. An Analysis on Secure Millimeter Wave NOMA Communications in Cognitive Radio Networks
- Author
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Yi Song, Weiwei Yang, Hui Wang, Zhongwu Xiang, Nan Sha, and Yucui Yang
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General Computer Science ,Computer science ,Reliability (computer networking) ,stochastic geometry ,0211 other engineering and technologies ,Throughput ,02 engineering and technology ,millimeter wave (mmWave) ,Interference (wave propagation) ,Noma ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,cognitive radio (CR) ,General Materials Science ,021110 strategic, defence & security studies ,business.industry ,General Engineering ,020206 networking & telecommunications ,medicine.disease ,Cognitive radio ,Non-orthogonal multiple access (NOMA) ,Key (cryptography) ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,business ,lcsh:TK1-9971 ,Computer network - Abstract
In this paper, an easy analysis framework is developed to evaluate the reliability and security of the secondary receivers (SU-Rxs) in millimeter wave (mmWave) non-orthogonal multiple access (NOMA) aided cognitive radio (CR) networks, where secondary transmitters (SU-Txs) transmit confidential messages to SU-Rxs belonging to different regions under the interference temperature constraint of the primary receiver (PU-Rx). Considering that randomly located eavesdroppers and primary user may be in the signal beam emitted by the SU-Txs, information leakage and interference to the primary network will be inevitable issues. Motivated by these challenges, combining the key features of multi-cell mmWave networks and NOMA communications, the closed-form expressions of three key performance metrics of connection outage probability (COP), secrecy outage probability (SOP), and secrecy throughput (ST) are derived by using the sector eavesdropper-exclusion zone, and the reliability and secrecy performance of the secondary networks are measured by different system parameters. The obtained performance evaluation results have demonstrated that the interference temperature constraint of the PU-Rx can be used to balance the security and reliability of the secondary networks. The reliability and security of paired NOMA users can be improved by using reasonable power allocation factor and sector eavesdropper-exclusion zone. Meanwhile, the connection performance of paired NOMA users is better than orthogonal multiple access (OMA). Furthermore, various system parameters can be reasonably set in conjunction with blockage and inter-cell interference to achieve optimal network’s performance.
- Published
- 2020
5. Enhancing Physical Layer Security Performance in Downlink Cellular Networks through Cooperative Users
- Author
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Nan Sha, Liu Xiaochen, Guangna Zhang, Yuanyuan Gao, Kui Xu, Mingxi Guo, and Shijie Wang
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business.industry ,Computer science ,Applied Mathematics ,Signal Processing ,Telecommunications link ,Cellular network ,Physical layer ,Electrical and Electronic Engineering ,business ,Computer Graphics and Computer-Aided Design ,Computer network - Published
- 2019
6. SWIPT in mMIMO system with non-linear energy-harvesting terminals: protocol design and performance optimization
- Author
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Ming Zhang, Kui Xu, Jie Liu, Wei Xie, Lihua Chen, and Nan Sha
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Beamforming ,Computer Networks and Communications ,Computer science ,lcsh:TK7800-8360 ,02 engineering and technology ,lcsh:Telecommunication ,Base station ,0203 mechanical engineering ,lcsh:TK5101-6720 ,Telecommunications link ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Maximum power transfer theorem ,Wireless ,Beam-domain channel representation ,Simultaneous wireless information and power transfer ,Achievable sum-rate ,business.industry ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,lcsh:Electronics ,020302 automobile design & engineering ,020206 networking & telecommunications ,Spectral efficiency ,Transmitter power output ,Computer Science Applications ,Signal Processing ,business ,Massive MIMO ,Energy harvesting - Abstract
In this paper, we design the simultaneous wireless information and power transfer (SWIPT) protocol for massive multi-input multi-output (mMIMO) system with non-linear energy-harvesting (EH) terminals. In this system, the base station (BS) serves a set of uplink fixed half-duplex (HD) terminals with non-linear energy harvester. Considering the non-linearity of practical energy-harvesting circuits, we adopt the realistic non-linear EH model rather than the idealistic linear EH model. The proposed SWIPT protocol can be divided into two phases. The first phase is designed for terminals EH and downlink training. A beam domain energy beamforming method is employed for the wireless power transmission. In the second phase, the BS forms the two-layer receive beamformers for the reception of signals transmitted by terminals. In order to improve the spectral efficiency (SE) of the system, the BS transmit power- and time-switching ratios are optimized. Simulation results show the superiority of the proposed beam-domain SWIPT protocol on SE performance compared with the conventional mMIMO SWIPT protocols.
- Published
- 2019
7. Serially Concatenated CPM in Two-Way Relay Channels with Physical-Layer Network Coding
- Author
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Yuanyuan Gao, Chen Lihua, Nan Sha, Kui Xu, and Mingxi Guo
- Subjects
Physical layer network coding ,Relay ,law ,business.industry ,Computer science ,Applied Mathematics ,Signal Processing ,Electrical and Electronic Engineering ,business ,Computer Graphics and Computer-Aided Design ,law.invention ,Computer network - Published
- 2019
8. Paricalcitol alleviates lipopolysaccharide-induced depressive-like behavior by suppressing hypothalamic microglia activation and neuroinflammation
- Author
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Duan fang Liao, Man Sau Wong, Nan Chen, Zhe Shi, Ming chao He, Yongjun Wang, Nan nan Sha, Ti fei Yuan, Yan Zhang, Xiao-Li Dong, and Shi yu Peng
- Subjects
Lipopolysaccharides ,Male ,0301 basic medicine ,Paricalcitol ,Lipopolysaccharide ,medicine.medical_treatment ,Hypothalamus ,Pharmacology ,Systemic inflammation ,Biochemistry ,Pathogenesis ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine ,Animals ,Neuroinflammation ,Inflammation ,Microglia ,Depression ,business.industry ,Antidepressive Agents ,Pathophysiology ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,Cytokine ,chemistry ,030220 oncology & carcinogenesis ,Ergocalciferols ,Inflammation Mediators ,medicine.symptom ,business ,medicine.drug - Abstract
Depression is highly prevalent in patients suffering from chronic inflammatory diseases. Dysregulated neuroinflammation and concomitant activated microglia play a pivotal role in the pathogenesis of depression. Paricalcitol (Pari), a vitamin D2 analogue, has been demonstrated to exert anti-inflammative effects on renal and cardiovascular diseases. In this study, mice were pretreated with Pari before being induced to acute depression-like behaviors by systemic lipopolysaccharide (LPS) injection. To determine the therapeutic effects of Pari, alterations in acute body weight, sucrose preference, forced swimming and tail suspension tests were assessed. Then, alterations of pro-inflammation cytokine IL1-β level and microglia activity in the hypothalamus, which are involved in the pathophysiology of depression, were examined. The results showed that Pari significantly alleviated systemic LPS injection induced depressive-like behaviors as shown by increased sucrose preference and decreased TST and FST immobility. Pari could specifically regulate microglia-mediated neuroinflammation process and local activity of renin-angiotensin system to exert its anti-depressant effects. This study demonstrated a potential for paricalcitol in treating depressive symptoms induced by systemic inflammation, particularly in patients with chronic hypertension.
- Published
- 2019
9. Security Performance Analysis for Relay Selection in Cooperative Communication System under Nakagami-m Fading Channel
- Author
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Huadong Luo, Shijie Wang, Guangna Zhang, Yuanyuan Gao, Kui Xu, and Nan Sha
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Computer Networks and Communications ,Computer science ,business.industry ,Nakagami distribution ,Communications system ,law.invention ,Relay ,law ,Fading ,Electrical and Electronic Engineering ,business ,Software ,Selection (genetic algorithm) ,Computer network - Published
- 2019
10. Secrecy Throughput Optimization for the WPCNs With Non-Linear EH Model
- Author
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Mingxi Guo, Liu Xiaochen, Nan Sha, and Yuanyuan Gao
- Subjects
General Computer Science ,business.industry ,Computer science ,Transmitter ,General Engineering ,secrecy throughput ,Throughput ,Data_CODINGANDINFORMATIONTHEORY ,physical layer security (PLS) ,Transmitter power output ,non-linear energy harvesting (EH) model ,Base station ,Wireless powered communication networks (WPCNs) ,Secure communication ,robust beamforming ,Artificial noise ,Wireless ,General Materials Science ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,business ,lcsh:TK1-9971 ,Communication channel ,Computer network ,Computer Science::Cryptography and Security ,Computer Science::Information Theory - Abstract
This paper investigates secure communication from a wireless-powered transmitter to a desired receiver with multiple eavesdroppers in the wireless powered communication networks (WPCNs). Considering the non-linear energy harvesting (EH) model, we propose a secure two-phase communication protocol with the help of a hybrid base station (HBS). First, in the power transfer (PT) phase, the HBS transfers wireless power to the transmitter. Then in the subsequent secure information transmission (SIT) phase, the transmitter sends the secret information using the energy harvested in the PT, under the protection of artificial noise (AN) generated by the HBS. First, based on this communication protocol, we maximize the secrecy throughput with perfect channel information state (CSI) under the transmit power constraint at the HBS. The secrecy throughput maximization (STM) problem is non-convex, and hence we reformulate it by exploiting the primal decomposition method (PDM) to obtain tractable forms. The PDM-based transmit scheme (PDM-TS) is proposed for the STM. In addition, considering the imperfect CSI of wiretap channel, we further design the robust transmit scheme for the worst-case secrecy throughput maximization (wSTM) problem. Since the wSTM shows high non-convexity, we extend the PDM by combining it with the S -procedure, and the PDM-based robust transmit scheme (PDM-RTS) is proposed for the wSTM. Finally, the numerical simulations are provided to show the effectiveness of the proposed transmit schemes.
- Published
- 2019
11. The naturally derived small compound Osthole inhibits osteoclastogenesis to prevent ovariectomy-induced bone loss in mice
- Author
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Yongjian Zhao, Bing Shu, Shufen Liu, Qi Shi, Qiang Wang, Dezhi Tang, Nan-Nan Sha, Hao Zhang, Yufeng Dong, Yongjun Wang, Dongfeng Zhao, Sheng Lu, and Yan Zhang
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0301 basic medicine ,medicine.medical_specialty ,Cell Survival ,Ovariectomy ,Cathepsin K ,Osteoporosis ,Osteoclasts ,Bone resorption ,Mice ,03 medical and health sciences ,Coumarins ,Osteogenesis ,Osteoclast ,In vivo ,Internal medicine ,Drug Discovery ,medicine ,Animals ,Humans ,Bone Resorption ,Osteoporosis, Postmenopausal ,Analysis of Variance ,NFATC Transcription Factors ,biology ,Tartrate-Resistant Acid Phosphatase ,business.industry ,RANK Ligand ,Obstetrics and Gynecology ,medicine.disease ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,Primary bone ,Endocrinology ,Matrix Metalloproteinase 9 ,RANKL ,biology.protein ,Ovariectomized rat ,Female ,business ,Proto-Oncogene Proteins c-fos ,Injections, Intraperitoneal ,Signal Transduction - Abstract
OBJECTIVE This study was to determine the bone protective effects and underlying mechanisms of Osthole (OT) in ovariectomized (OVX) mice. We found that the inhibitory effects of OT on receptor activator of nuclear factor kappa-B ligand (RANKL)-activated osteoclastogenesis are responsible for its bone protective effects in OVX mice. METHODS Eight-week-old mice were ovariectomized and OT (10 mg/kg/d) was intraperitoneally administrated to OVX mice 7 days after the surgery and were sacrificed at the end of the 3 months. Osteoclasts were generated from primary bone marrow macrophages (BMMs) to investigate the inhibitory effects of OT. The activity of RANKL-activated signaling was simultaneously analyzed in vitro and in vivo using immunohistochemistry, Western blot, and PCR assays. RESULTS OT dose dependently inhibited RANKL-mediated osteoclastogenesis in BMM cultures. OT administration attenuated bone loss (mg Ha/cm: 894.68 ± 33.56 vs 748.08 ± 19.51, P
- Published
- 2018
12. Muscone Ameliorates LPS-Induced Depressive-Like Behaviors and Inhibits Neuroinflammation in Prefrontal Cortex of Mice
- Author
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Nan-Nan Sha, Meng Qin, Ti-Fei Yuan, Ming-Chao He, Bing Shu, Fu-Hui Lin, Yongjun Wang, Yan Zhang, Yue-li Sun, Duan-Fang Liao, Zhe Shi, and Yue Li
- Subjects
Lipopolysaccharides ,Male ,medicine.medical_specialty ,Central nervous system ,Prefrontal Cortex ,Inflammation ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Internal medicine ,Renin–angiotensin system ,Medicine ,Animals ,Prefrontal cortex ,Neuroinflammation ,Depression (differential diagnoses) ,030304 developmental biology ,0303 health sciences ,Microglia ,business.industry ,Depression ,Deer ,Body Weight ,Cycloparaffins ,General Medicine ,Muscone ,Toll-Like Receptor 4 ,medicine.anatomical_structure ,Endocrinology ,Complementary and alternative medicine ,chemistry ,Cytokines ,medicine.symptom ,Inflammation Mediators ,business ,030217 neurology & neurosurgery ,Injections, Intraperitoneal ,Signal Transduction - Abstract
Depression is partially caused by inflammation in the central nervous system. Early study demonstrated that musk, glandular secretion from male musk deer, exerted an antidepressant-like effect. The aim of this study was to investigate if muscone, a bioactive ingredient in musk, could ameliorate neuroinflammation and depressive-like behaviors as well as explore the potential action mechanism. Mice were intraperitoneally (i.p.) injected with muscone for 2 weeks prior to administration of lipopolysaccharides (LPS, 1[Formula: see text]mg/kg, i.p.). Pre-treatment with muscone reversed the LPS-induced decrease in body weight within 24[Formula: see text]h and ameliorated depressive-like behaviors shown by sucrose preference, tail suspension test, and forced swimming test. LPS-induced activation of microglial cells and elevation in expression of inflammatory cytokines including IL-1[Formula: see text], RANTES, and MCP-1 in the prefrontal cortex of mice were effectively abrogated by muscone, which significantly down-regulated expression of TLR4, MyD88, Caspase-1, NLRP3, renin, and Ang II. In addition, treatment of BV2 microglia cells with muscone markedly attenuated the LPS-induced rise in protein expression of TLR4, Ang II, and IL-1[Formula: see text]. This study revealed that muscone could ameliorate LPS-induced depressive-like behaviors by repressing neuroinflammation in the prefrontal cortex of mice caused by its suppression on microglia activation and production of inflammatory cytokines via acting on TLR4 pathway and RAS cascade.
- Published
- 2020
13. Research on the Supply Side of Ideological and Political Education in Colleges and Universities under the Background of 'Internet +'
- Author
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Nan Sha
- Subjects
Political education ,business.industry ,media_common.quotation_subject ,Political science ,The Internet ,Ideology ,Supply side ,Public relations ,business ,media_common - Published
- 2020
14. Urban-Rural Differences in Bone Mineral Density and its Association with Reproductive and Menstrual Factors Among Older Women
- Author
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Jinlong Li, Da Weiwei, Jing Wang, Hao Zhang, Li Liu, Yimian Li, Xiaoyun Wang, Sheng Lu, Qiao Liang, Nan-Nan Sha, Jianxing Luo, Yongjian Zhao, Lin Chen, Xiaofeng Qi, Wei-Qiang Zhang, Sen Zhu, Qi Shi, Bing Shu, Xue-Jun Cui, Xu Chongqing, Yin Zhu, Chen-Guang Li, Qiang Wang, Yongjun Wang, and Qianqian Liang
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musculoskeletal diseases ,0301 basic medicine ,Rural Population ,China ,Urban Population ,Endocrinology, Diabetes and Metabolism ,Osteoporosis ,030209 endocrinology & metabolism ,Lumbar vertebrae ,Family income ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Absorptiometry, Photon ,Bone Density ,Pregnancy ,Risk Factors ,medicine ,Humans ,Orthopedics and Sports Medicine ,Aged ,Bone mineral ,Menarche ,Lumbar Vertebrae ,business.industry ,medicine.disease ,Menopause ,Parity ,medicine.anatomical_structure ,Female ,030101 anatomy & morphology ,Rural area ,business ,Parity (mathematics) ,Demography - Abstract
This study aimed to compare the bone mineral density (BMD) of older women living in rural and urban areas, and evaluate the potential factors affecting the risk of osteoporosis. We recruited 574 women aged 65 years or older from rural areas and 496 from urban areas in Shanghai, China. The BMD values of the lumbar vertebrae and total left hip were measured by a dual energy X-ray absorptiometry densitometer. We also recorded information about education level, family income, medications, reproductive and menstrual history, diet, smoking, and alcohol consumption. Women in urban areas had significantly higher BMD in their lumbar spine, and there was a dramatic increase in the proportion of women with osteoporosis in rural areas. The age at menarche was significantly higher among women living in rural areas, and there were more years from menarche to menopause among urban women. Rural women had significantly higher numbers of both pregnancies and parity, and a significantly lower age at first parity. In multiple linear regression analyses, years from menarche to menopause was independently related to high lumbar spine BMD, while age at menarche and parity was independently related to low lumbar spine BMD. More older women in rural areas had osteoporosis. Later menarche, less years from menarche to menopause and higher parity might partially contribute to decreased BMD among women in rural areas. More attention should be paid to women in rural areas to prevent bone loss and further bone and health impairment.
- Published
- 2019
15. Cooperative Jamming in Downlink Cellular Networks with Available Eavesdroppers' Location Information
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Yuanyuan Gao, Huang Sheng, Lei Wu, Nan Sha, Shijie Wang, and Wang Xiaoyu
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021110 strategic, defence & security studies ,business.industry ,Computer science ,0211 other engineering and technologies ,Physical layer ,020206 networking & telecommunications ,Jamming ,Eavesdropping ,Data_CODINGANDINFORMATIONTHEORY ,02 engineering and technology ,Energy consumption ,Interference (wave propagation) ,Telecommunications link ,0202 electrical engineering, electronic engineering, information engineering ,Cellular network ,business ,Computer network - Abstract
In this paper, we enhance physical layer security performance of downlink cellular networks through cooperative jamming technology. Assuming the locations of eavesdroppers (Eve) are available, idle user equipments (UE) are carefully selected to cooperatively transmit jamming signal to confuse eavesdroppers (Eve). Analytical expressions of the connection and secrecy performances are derived, which are validated through Monte Carlo simulations. Simulation results demonstrate that our proposed scheme can improve connection performance, while approaches the secrecy performance of [12]. Furthermore, only 6% idle UEs of [12] are used for cooperative jamming, which helps to decrease energy consumption of network.
- Published
- 2019
16. A Physical Layer Encryption Scheme Based on Symbol Convolution for MISO Secure Transmission
- Author
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Huang Sheng, Yuanyuan Gao, Nan Sha, and Heping Xi
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Computer science ,business.industry ,05 social sciences ,Physical layer ,050801 communication & media studies ,020206 networking & telecommunications ,02 engineering and technology ,Transmission security ,Encryption ,Convolution ,0508 media and communications ,Secure communication ,Modulation ,0202 electrical engineering, electronic engineering, information engineering ,Wireless ,business ,Algorithm ,Secure transmission ,Computer Science::Information Theory ,Computer Science::Cryptography and Security - Abstract
In order to enhance the transmission security for the multiple-input single-output (MISO) system, a new physical layer encryption (PLE) scheme based on symbol convolution (CONV-EN) is proposed. Exploiting the randomness and reciprocity of wireless channels, this scheme can effectively counter modulation recognition based on constellation reconstruction and high-order cumulants. The simulation results suggest that this scheme delivers better security performance than the original symbol phase rotated (OSPR) scheme in [9] over quasi-static Rayleigh channel and improves the reliability of encrypted secure communication compared to the PLE scheme in [10].
- Published
- 2019
17. Secure Transmit Beamforming in the RF Powered Untrusted Relay networks
- Author
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Nan Sha, Xiaochen Liu, Gao Yuanyuan, and Huang Sheng
- Subjects
Beamforming ,Computer science ,business.industry ,Quality of service ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Transmitter power output ,law.invention ,Relay ,law ,business ,Communications protocol ,Electrical efficiency ,Protocol (object-oriented programming) ,Secure transmission ,Computer network - Abstract
This paper investigates secure transmission in the radio-frequency (RF) powered untrusted relay networks. The relay conducts amplify-and-forward (AF) protocol and may intercept information passively. Based on the physical-layer security technique, a two-phase communication protocol is proposed for transmit security. We aim to minimize the average total transmit power by jointly designing the transmit parameters of the networks under the security quality of service (QoS). The power minimization problem is non-convex, hence an alternative optimization (AO) based algorithm is proposed. The simulation results show that the proposed transmit scheme can significantly increase the power efficiency.
- Published
- 2019
18. Secure User Association in Two-Tier Heterogeneous Cellular Networks With In-Band Interference
- Author
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Shijie Wang, Nan Sha, Chao Dong, Yuanyuan Gao, and Guozhen Zang
- Subjects
General Computer Science ,Network security ,Computer science ,stochastic geometry ,in-band interference ,0211 other engineering and technologies ,Throughput ,02 engineering and technology ,Interference (wave propagation) ,Connection and secrecy probability ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,Computer Science::Cryptography and Security ,Computer Science::Information Theory ,021110 strategic, defence & security studies ,business.industry ,physical layer security ,General Engineering ,Physical layer ,020206 networking & telecommunications ,Eavesdropping ,Cellular network ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,business ,lcsh:TK1-9971 ,Heterogeneous network ,Computer network - Abstract
In this paper, we address the issue of security-concerned user association in two-tier heterogeneous cellular networks with in-band interference. Different from the maximum secrecy capacity association (max-SC), which studied multi-tier heterogeneous networks without in-band interference, we consider the max-SC problem with in-band interference. Considering the intractability of the max-SC scheme under in-band interference scenario, we derive a simplified max-SC scheme based on the Maclaurin formulation. Network connection and secrecy probability, as well as network secrecy throughput, are analyzed under our association scheme through stochastic geometry. Simulation results demonstrate that the proposed scheme can approach the performance of the max-SC association, in terms of secrecy probability and network secrecy throughput, and performs better in terms of connection probability. Comparing with the previous work, the proposed scheme performs better in connection, secrecy probability, and secrecy throughput.
- Published
- 2018
19. Joint Single Relay and Jammer Selection for Physical Layer Security Enhancement in Internet of Things
- Author
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Li Yigao, Huadong Luo, Guangna Zhang, Guozhen Zang, Yuanyuan Gao, and Nan Sha
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business.industry ,Computer science ,Physical layer ,020206 networking & telecommunications ,020302 automobile design & engineering ,Nakagami distribution ,Jamming ,02 engineering and technology ,law.invention ,Channel capacity ,0203 mechanical engineering ,Relay ,law ,0202 electrical engineering, electronic engineering, information engineering ,Fading ,business ,Joint (audio engineering) ,Selection (genetic algorithm) ,Computer network - Abstract
Internet of Things (IoT) plays a significant role in facilitating our work and making ease the life of human, for the reason that it can connect a lot of embedded devices to deal with many complicated and difficult tasks. However, security of IoT is more concern because every device is connected through internet network, and eavesdroppers are ready to steal or even uncover our private data. Therefore, in this paper, we propose joint single relay and jammer selection (JSRJS) to enhance the physical layer security (PLS) of IoT. Moreover, outage probability (OP) and intercept probability (IP) as well as the system tradeoff performance (STP) for JSRJS under Nakagami-m fading channel are analyzed, and OP、IP as well as STP of JSRJS are all compared with that of the pure single relay selection (SRS), respectively. Simulation results show that the OP of JSRJS is the same as that of SRS, while the IP of JSRJS is always better than that of SRS. In addition, the STP for JSRJS is also more perfect than that of SRS. Besides, as the number of relay nodes increases, the STP of these two approaches both improve notably.
- Published
- 2018
20. Opportunistic Relay Selection for Physical Layer Security Enhancement in Internet of Things
- Author
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Nan Sha, Yuanyuan Gao, Huadong Luo, Shijie Wang, and Guangna Zhang
- Subjects
business.industry ,Computer science ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Physical layer ,020302 automobile design & engineering ,020206 networking & telecommunications ,Nakagami distribution ,Data_CODINGANDINFORMATIONTHEORY ,02 engineering and technology ,Outage probability ,law.invention ,0203 mechanical engineering ,Relay ,law ,0202 electrical engineering, electronic engineering, information engineering ,Fading ,Security enhancement ,business ,Internet of Things ,Selection (genetic algorithm) ,Computer network - Abstract
Internet of Things (IoT) is playing an important role in our lives. It connects lots of embedded devices, which can deal with very complicated and difficult tasks to facilitate our work. However, the security of IoT faces many challenges due to the wireless broadcasting nature and the energy constraint of the physical objects. In order to provide a secure environment for IoT, in this paper, we investigate two opportunistic relay selection schemes to further enhance physical layer security, which are single relay selection(SRS) and multi relay selection(MRS) respectively. We analyze the outage probability (OP) and intercept probability (IP) as well as the system tradeoff performance (STP) for SRS and MRS under Nakagami-m fading channel. Simulation results show that the OP and IP of MRS are all better than that of SRS. Besides, the STP for MRS is also more perfect than that of SRS. What's more, the STP of these two opportunistic relay selection schemes improve with the increasing of relay numbers.
- Published
- 2018
21. Research on the College Students' Education in the Perspective of New Media
- Author
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Yang Zhang and Nan Sha
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New media technology ,Higher education ,business.industry ,Perspective (graphical) ,ComputingMilieux_COMPUTERSANDEDUCATION ,College education ,University education ,Sociology ,Product (category theory) ,Public relations ,business ,New media - Abstract
New media technology is the product of the new era. It is not only accepted and relied by college students, but also brings unprecedented opportunities for higher education. New media has a huge amount of information, strong interaction, quick and convenience, becoming an important extracurricular channel for college students. Moreover, information offered by the new media is so large that is beyond any previous media. To promote the college education, we should know and understand the new media in a timely manner and have a reasonable use of the characteristics that the new media is easily accepted by college students.
- Published
- 2017
22. Analyzing the physical layer security performance of the ANC system
- Author
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Gao Yuanyuan, Yuyang Zhang, Baofeng Yang, and Nan Sha
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Transmission (telecommunications) ,Network security ,business.industry ,Computer science ,Linear network coding ,Physical layer ,Electronic engineering ,Eavesdropping ,Data_CODINGANDINFORMATIONTHEORY ,business ,Interference (wave propagation) ,Relay channel ,Communication channel - Abstract
Based on the theory of physical layer security (PLS), this paper demonstrates that analog network coding (ANC) has ability to improve the PLS performance of the two-way relay channel against different kinds of eavesdroppers. In this paper, we define the security and unsecurity region and derive the system security capacity with ANC and traditional transmission schemes. In particular, we consider external and internal eavesdroppers respectively. Besides, we investigate the factors influencing the ANC system PLS performance. The simulation results show that ANC can greatly improve the system PLS performance against an external eavesdropper, and ensure that an internal eavesdropper cannot decode any confidential information. Furthermore, the ANC system PLS performance can be slightly improved by increasing signal source's transmission power level and eavesdropping channel's noise level.
- Published
- 2017
23. A distinctive method to improve the security capacity of backscatter wireless system
- Author
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Fuxing Yao, Huiying Song, Qian Zhou, Yuanyuan Gao, and Nan Sha
- Subjects
021110 strategic, defence & security studies ,business.industry ,Computer science ,Noise (signal processing) ,0211 other engineering and technologies ,Physical layer ,020206 networking & telecommunications ,Data_CODINGANDINFORMATIONTHEORY ,02 engineering and technology ,Communications system ,law.invention ,System model ,Relay ,law ,0202 electrical engineering, electronic engineering, information engineering ,Artificial noise ,Wireless ,Telecommunications ,business ,Computer Science::Cryptography and Security ,Computer Science::Information Theory ,Computer network ,Communication channel - Abstract
Backscatter communication system is the backbone of many low cost and low power distributed wireless systems. This paper studies the physical layer security (PLS) performance of a backscatter system which contains several relays and an eavesdropper. We discuss the conditions for a positive secrecy rate of the system in two different situations. First, in the case of known information of eavesdropper, we use a sub-optimal relay selection method to secure backscatter communication and maximize the secrecy rate. The simulation results prove the suboptimal scheme with low complexity achieves the same effects as the optimal one. But the transmission rate is very low due to the difference between the main channel and eavesdropper channel is too little, so we put forward the second distinctive method. Second, without knowing any information of eavesdropper, we adopt the artificial noise (AN) technique to reduce the received signal to interference noise (SINR) of eavesdropper, and came to a conclusion that under the condition of the same system model, adding a weak AN greatly improves the secrecy rate compared to situation one, and it doesn't required to obtain any information of eavesdropper. In small power of this type of communication system, this method is also effective.
- Published
- 2017
24. MSK Modulation for Physical-Layer Network Coding Systems
- Author
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Nan Sha, Weiwei Yang, Yuanyuan Gao, Xiaoxin Yi, and Wei Jian
- Subjects
Physical layer network coding ,Modulation ,business.industry ,Computer science ,Applied Mathematics ,Linear network coding ,Signal Processing ,Electronic engineering ,Electrical and Electronic Engineering ,Minimum-shift keying ,business ,Computer Graphics and Computer-Aided Design ,Computer network - Published
- 2014
25. Design and Simulation of Bit-interleaved SCCPM with Physical-layer Network Coding
- Author
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Shijie Wang, Yuanyuan Gao, Mingxi Guo, and Nan Sha
- Subjects
Physical layer network coding ,Bit (horse) ,business.industry ,Computer science ,business ,Computer hardware - Published
- 2019
26. Strategic assessment of fuel taxation in energy conservation and CO2 reduction for road transportation: a case study from China
- Author
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Nan Sha, Yutao Wang, Lars Hansson, Jian Liu, Renqing Wang, and Yanqiang Ding
- Subjects
Environmental Engineering ,Natural resource economics ,Fuel tax ,Developing country ,Energy consumption ,Energy conservation ,Econometric model ,Overconsumption ,Greenhouse gas ,Environmental Chemistry ,Business ,Safety, Risk, Reliability and Quality ,Externality ,General Environmental Science ,Water Science and Technology - Abstract
Road transportation has attracted extensive attention throughout the world because of its high energy demands and numerous externalities. Sustainable road transportation has thus become a great challenge for politicians and decision-makers all over the world. There have been a series of studies indicating that appropriate pricing of fuel can be both effective and efficient for reducing overconsumption of transport fuel. However, relatively little research has been done on fuel price approaches in developing country contexts. For a country like China, where road traffic today is growing more than in other countries, there is a strategic interest to do more economic analyses of fair and efficient pricing of fuel. In this study, we present a strategic assessment of fuel pricing in energy conservation and CO2 reduction from road transportation in China, both in a retrospective and a prospective perspective. First of all, the correlation between fuel price and road transport gasoline demand, based upon data from 1995 to 2007, was examined with an econometric model. Secondly, on basis of the elasticity model, the potential reductions with respect to fuel demand and Green House Gas (GHG) emissions as a consequence of a strategic fuel tax implementation in China were examined up to 2030. The results indicate that such strategic fuel taxation can play a considerable role in steering the growth of road transport gasoline demand, and thus also Chinese GHG emissions.
- Published
- 2012
27. Study on the Freeze-Drying Dual-Evaporator Refrigeration System
- Author
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Peng Xia, Hua Nan Sha, and Min Liang Zhang
- Subjects
Waste management ,business.industry ,Chemistry ,Heat pump and refrigeration cycle ,General Engineering ,Refrigeration ,Valve opening ,Freeze-drying ,Thermal expansion valve ,Heat exchanger ,Process engineering ,business ,Evaporator ,Cold trap - Abstract
In the freeze-dryer, the dual-evaporator refrigeration system is used to meet the demands of the freeze-drying technology. One evaporator is used as “cold trap”, and the other one, shelf evaporator, is used to control materials’ temperature. In this paper, experimental study on the dual-evaporator refrigeration system in the process of freeze-drying is carried out. First, the influence of valve opening on the dual-evaporator refrigeration system is analyzed. Secondly, the influence of vacuum on the surface temperature of the heat exchanger is analyzed. Finally, the influence of the varied evaporation temperature on the first drying rate is analyzed.
- Published
- 2012
28. Differential response of bone and kidney to ACEI in db/db mice: A potential effect of captopril on accelerating bone loss
- Author
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Yong Jian Zhao, Xiao-Li Li, Nan nan Sha, Hui Hui Xiao, Yongjun Wang, Qi Shi, Man Sau Wong, Xinluan Wang, Bing Shu, and Yan Zhang
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Histology ,Captopril ,Physiology ,Endocrinology, Diabetes and Metabolism ,Osteoporosis ,Osteoclasts ,030209 endocrinology & metabolism ,Angiotensin-Converting Enzyme Inhibitors ,Bone tissue ,Kidney ,Bone resorption ,Bone and Bones ,Diabetes Mellitus, Experimental ,Renin-Angiotensin System ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Animals ,Femur ,RNA, Messenger ,Bone Resorption ,Vitamin D3 24-Hydroxylase ,Bone mineral ,Osteoblasts ,Tibia ,Bone Injury ,business.industry ,Angiotensin II ,Glomerulosclerosis ,X-Ray Microtomography ,medicine.disease ,Fibrosis ,Mice, Inbred C57BL ,030104 developmental biology ,Endocrinology ,medicine.anatomical_structure ,Calcium ,business ,Biomarkers ,medicine.drug - Abstract
The components of renin-angiotensin system (RAS) are expressed in the kidney and bone. Kidney disease and bone injury are common complications associated with diabetes. This study aimed to investigate the effects of an angiotensin-converting enzyme inhibitor, captopril, on the kidney and bone of db/db mice. The db/db mice were orally administered by gavage with captopril for 8weeks with db/+ mice as the non-diabetic control. Serum and urine biochemistries were determined by standard colorimetric methods or ELISA. Histological measurements were performed on the kidney by periodic acid-schiff staining and on the tibial proximal metaphysis by safranin O and masson-trichrome staining. Trabecular bone mass and bone quality were analyzed by microcomputed tomography. Quantitative polymerase chain reaction and immunoblotting were applied for molecular analysis on mRNA and protein expression. Captopril significantly improved albuminuria and glomerulosclerosis in db/db mice, and these effects might be attributed to the down-regulation of angiotensin II expression and the expression of its down-stream profibrotic factors in the kidney, like connective tissue growth factor and vascular endothelial growth factor. Urinary excretion of calcium and phosphorus markedly increased in db/db mice in response to captopril. Treatment with captopril induced a decrease in bone mineral density and deterioration of trabecular bone at proximal metaphysis of tibia in db/db mice, as shown in the histological and reconstructed 3-dimensional images. Even though captopril effectively reversed the diabetes-induced changes in calcium-binding protein 28-k and vitamin D receptor expression in the kidney as well as the expression of RAS components and bradykinin receptor-2 in bone tissue, treatment with captopril increased the osteoclast-covered bone surface, reduced the osteoblast-covered bone surface, down-regulated the expression of type 1 collagen and transcription factor runt-related transcription factor 2 (markers for osteoblastic functions), and up-regulated the expression of carbonic anhydrase II (marker for bone resorption). Captopril exerted therapeutic effects on renal injuries associated with type 2 diabetes but worsened the deteriorations of trabecular bone in db/db mice; the latter of which was at least in part due to the stimulation of osteoclastogenesis and the suppression of osteogenesis by captopril.
- Published
- 2016
29. Risk Factors Predictive of Recurrence and Progression for Patients Who Suffered Initial Recurrence After Transurethral Resection of Stage pT1 Bladder Tumor in Chinese Population: A Retrospective Study
- Author
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Hailong Hu, Tao Chen, Zhonghua Shen, Dawei Tian, Nan Sha, Chang-Li Wu, Na Ding, Hao Xu, Linguo Xie, Zhouliang Wu, Chen Xing, Yu Zhang, and Xiaoteng Liu
- Subjects
Oncology ,Adult ,Male ,medicine.medical_specialty ,China ,Multivariate analysis ,030232 urology & nephrology ,Observational Study ,urologic and male genital diseases ,Disease-Free Survival ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Internal medicine ,medicine ,Humans ,Stage (cooking) ,Aged ,Neoplasm Staging ,Proportional Hazards Models ,Retrospective Studies ,Aged, 80 and over ,Bladder cancer ,Receiver operating characteristic ,Surrogate endpoint ,Proportional hazards model ,business.industry ,Carcinoma in situ ,Retrospective cohort study ,General Medicine ,Middle Aged ,medicine.disease ,female genital diseases and pregnancy complications ,Surgery ,Urinary Bladder Neoplasms ,030220 oncology & carcinogenesis ,Multivariate Analysis ,Disease Progression ,Urologic Surgical Procedures ,Female ,Neoplasm Recurrence, Local ,business ,Research Article - Abstract
Bladder cancer is one of the most common malignancies worldwide and the stage pT1nonmuscle invasive bladder cancer (NMIBC) has a high probability of recurrence after initial diagnosis and treatment. However, risk factors predictive of repeated recurrence and progression of pT1 bladder tumors after primary relapse have not been uncovered. Thus, we conducted the retrospective study. A total of 418 patients who suffered initial recurrence after transurethral resection (TUR) of pT1 bladder tumor were selected for the analyses. Clinic information of the patients was retrieved from their medical records. Recurrence-free survival (RFS) and progression-free survival (PFS) were estimated using the Kaplan–Meier method. Univariate and multivariate analyses were performed using a Cox proportional hazards regression model. The probability of recurrence and progression by multivariate analyses was used as a surrogate marker to construct receiver operating curve (ROC). Results showed that variables including time to prior recurrence time, prior treatment, number of tumor, tumor size, tumor grade, and time of instillation after surgery were associated with the repeated recurrence of pT1 bladder tumor (P
- Published
- 2016
30. AB180. Impact of lymphovascular invasion on recurrence and progression rates in patients with pT1 urothelial carcinoma of bladder after transurethral resection
- Author
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Hailong Hu, Changli Wu, and Nan Sha
- Subjects
medicine.medical_specialty ,recurrence ,business.industry ,Lymphovascular invasion ,Urology ,Urinary bladder neoplasms ,urologic and male genital diseases ,female genital diseases and pregnancy complications ,Resection ,body regions ,Printed Abstracts ,Reproductive Medicine ,lymphovascular invasion (LVI) ,medicine ,In patient ,Clinical significance ,progression ,business ,Urothelial carcinoma - Abstract
Objective To evaluate the clinical significance of lymphovascular invasion (LVI) on recurrence and progression rates in patients with pT1 urothelial carcinoma of bladder after transurethral resection Methods This retrospective study was performed with 155 patients with newly diagnosed pT1 urothelial carcinoma of bladder who were treated with transurethral resection of bladder tumor (TURBT) at our institution from January 2006 to January 2010. The presence or absence of LVI was examined according to our pathologists. Chi-square was performed to identify the correlations between LVI and other clinical and pathological features. Kaplan-Meier method was used to estimate the recurrence-free survival (RFS) and progression-free survival (PFS) curves and difference was determined by the log-rank test. Univariate and multivariate analyses were performed to determine the predictive factors through a Cox proportional hazards regression model. Results LVI was detected in a total of 34 patients (21.9%).While LVI was associated with high grade tumors (P
- Published
- 2016
31. Performance analysis of time division broadcast protocol with incremental relaying and symmetric users
- Author
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Yuanyuan Gao, Kun Xu, Guozhen Zang, Xiaoxin Yi, and Nan Sha
- Subjects
Protocol (science) ,Computer Networks and Communications ,business.industry ,Computer science ,Spectral efficiency ,Outage probability ,Division (mathematics) ,Multiplexing ,Transmission (telecommunications) ,Linear network coding ,Electrical and Electronic Engineering ,Telecommunications ,business ,Algorithm - Abstract
SUMMARY This paper investigates two-way relaying with direct link transmission. We propose to combine incremental relaying (IR) with the time division broadcast protocol (TDBC) to form a new scheme, termed TDBC-IR, to increase the spectral efficiency of TDBC. Assuming half-duplex decode-and-forward relaying, the performance of three protocols, that is, TDBC, TDBC-IR, and physical-layer network coding (PNC), are studied and compared, in terms of outage probability, expected rate (ER), and diversity-multiplexing tradeoff. First, we reveal that the outage probability performance of TDBC-IR is the same as that of TDBC and better than that of PNC. Second, we compare the ER and diversity-multiplexing tradeoff performance of the three protocols based on the derived outage probability. The numerical results reveal that (1) the ER of TDBC-IR is greater than that of TDBC and PNC in the whole signal-to-noise ratio (SNR) region, that is TDBC-IR has improved spectral efficiency performance; (2) the ER performance of TDBC is better than PNC in the low SNR region but worse in the high SNR region; (3) the maximum achievable diversity order of TDBC-IR and TDBC are both two whereas that of PNC is one; (4) the maximum achievable multiplexing gain of TDBC-IR is one, which is better than TDBC (its maximum achievable is 2/3) and achieves the maximum of PNC (its maximum achievable is one). Copyright © 2012 John Wiley & Sons, Ltd.
- Published
- 2012
32. Physical layer security for cooperative communication system with untrusted relay based on jamming signals
- Author
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Qianqian Zhang, Guozhen Zang, Yuyang Zhang, Yuanyuan Gao, and Nan Sha
- Subjects
business.industry ,Computer science ,Physical layer ,Eavesdropping ,Jamming ,Data_CODINGANDINFORMATIONTHEORY ,Communications system ,law.invention ,Relay ,law ,Demodulation ,business ,Computer network ,Phase-shift keying - Abstract
This paper investigates the cooperative communication system with untrusted relay using the new scheme that the source transmits the jamming signals and the source signals at the same time. We exploit greedy power allocation algorithm to divide the source power to ensure maximum secrecy capacity. Besides, we analyze the situation that external eavesdropper and untrusted relay exist at the same time. At the end of the paper, BPSK modulation and demodulation scheme is given as an example, and SER is used to estimate the performance of the system. The simulation results show that the scheme can resist both internal and external eavesdropping nodes.
- Published
- 2015
33. Joint CPFSK Modulation and Physical-Layer Network Coding in Two-Way Relay Channels
- Author
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Yuanyuan Gao, Xiaoxin Yi, Wenlong Li, Weiwei Yang, and Nan Sha
- Subjects
Continuous phase frequency shift keying ,Physical layer network coding ,Computer science ,business.industry ,Applied Mathematics ,Modulation index ,Computer Graphics and Computer-Aided Design ,law.invention ,Modulation ,Relay ,law ,Signal Processing ,Electronic engineering ,Electrical and Electronic Engineering ,business ,Joint (audio engineering) ,Quadrature amplitude modulation ,Computer network - Published
- 2014
34. Impact of squamous and/or glandular differentiation on recurrence and progression following transurethral resection for non-muscle invasive urothelial carcinoma of bladder
- Author
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Changli Wu, Yu Zhang, Zhouliang Wu, Linguo Xie, Hailong Hu, Xiaoyu Qiu, Chen Xing, Xiaoteng Liu, Tao Chen, Nan Sha, Zhonghua Shen, and Hao Xu
- Subjects
Oncology ,Cancer Research ,medicine.medical_specialty ,recurrence ,Invasive urothelial carcinoma ,030232 urology & nephrology ,Urology ,Glandular Differentiation ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,glandular ,medicine ,squamous ,Pathological ,urothelial carcinoma ,Oncogene ,Proportional hazards model ,business.industry ,Hazard ratio ,Cancer ,Articles ,medicine.disease ,Confidence interval ,030220 oncology & carcinogenesis ,progression ,business - Abstract
The aim of the present study was to investigate the impact of squamous and/or glandular differentiation on the recurrence and progression in patients with nonmuscle invasive urothelial carcinoma of bladder (NMIUCB) following transurethral resection (TURBT). A total of 869 patients with NMIUCB who had been treated with TURBT at The Second Hospital of Tianjin Medical University (Tianjin, China) between January 2006 and January 2011 were retrospectively selected for the present analysis. Associations among squamous and/or glandular differentiation with other clinical and pathological features were assessed by the χ2 test. Recurrence-free survival (RFS) and progression-free survival (PFS) curves were estimated using the Kaplan-Meier method. Univariate and multivariate analyses were performed through a Cox's proportional hazards regression model. Among the 869 patients, 232 (26.7%) patients had squamous and/or glandular differentiation. High grade tumors were more common in patients with squamous and/or glandular differentiation compared with those with pure urothelial carcinoma of bladder (P
- Published
- 2015
35. A lifetime-concerned probabilistic routing scheme in wireless cooperative sensor network
- Author
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Shijie Wang, Yuanyuan Gao, Nan Sha, Guozhen Zang, and Kun Xu
- Subjects
business.industry ,Wireless network ,Wireless ad hoc network ,Computer science ,Distributed computing ,Wireless WAN ,Key distribution in wireless sensor networks ,Shortest path problem ,Computer Science::Networking and Internet Architecture ,Mobile wireless sensor network ,business ,Wireless sensor network ,Dijkstra's algorithm ,Computer network - Abstract
Node cooperation is a promising feature in wireless sensor network, since the application of cooperative communication (CC) can vastly improve the energy efficiency of the network. In this paper, we investigate the Leach based clustering scheme, where the neighboring nodes dynamically form clusters to cooperatively transmit the gathered information to the sink. We model the wireless sensor network as an edge-weighted graph, in which the edge between two clusters is weighted by the energy cost. The famous Dijkstra algorithm is utilized to seek for the shortest path to the sink. Then the famous D-algorithm is modified to prolong the lifetime of the network. Numerical results confirm that the energy efficient routing can effectively enhance the performance of WSNs.
- Published
- 2015
36. OFDM-CPM signals in two-way relay channels with physical-layer network coding
- Author
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Yanshan Long, Wenlong Li, Chen Lihua, Yuanyuan Gao, Nan Sha, and Shijie Wang
- Subjects
Link Access Procedure for Frame Relay ,Continuous phase modulation ,Orthogonal frequency-division multiplexing ,business.industry ,Computer science ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Data_CODINGANDINFORMATIONTHEORY ,law.invention ,Relay ,law ,Linear network coding ,Computer Science::Networking and Internet Architecture ,Fading ,business ,Relay channel ,Decoding methods ,Computer Science::Information Theory ,Computer network - Abstract
Physical-layer network coding (PNC) has obtained much attention due to its ability to improve throughput in relay-aided communications. In this paper, we introduce orthogonal frequency division multiplexing-continuous phase modulation (OFDM-CPM) signals into a two-way relay (TWR) channel adopting the PNC protocol to form a new scheme. With PNC, the TWR communication is performed during two phases. In the multiple access (MAC) phase, the two users send OFDM-CPM signals concurrently to the relay, and the relay broadcasts the XORed version of the two users' data in the broadcast phase. We focus on the MAC phase and present a decoding scheme for the relay receiver. The error performance of the new scheme is provided by simulation results, and it is shown that the proposed scheme outperforms that of OFDM-PSK for PNC over frequency-selective fading channels.
- Published
- 2014
37. The evaluation of the association between the metabolic syndrome and tumor grade and stage of bladder cancer in a Chinese population
- Author
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Yu Zhang, Hailong Hu, Linguo Xie, Hao Xu, Xiaoteng Liu, Tao Chen, Dawei Tian, Zhouliang Wu, Zhonghua Shen, Chen Xing, Wanqin Xie, Nan Sha, and Changli Wu
- Subjects
obesity ,medicine.medical_specialty ,hypertension ,030232 urology & nephrology ,TNM staging system ,histologic grade and stage ,Gastroenterology ,metabolic syndrome ,OncoTargets and Therapy ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Medicine ,Pharmacology (medical) ,Stage (cooking) ,Original Research ,Gynecology ,Bladder cancer ,business.industry ,primary carcinoma of the bladder ,Cancer ,Odds ratio ,medicine.disease ,Oncology ,030220 oncology & carcinogenesis ,diabetes mellitus ,T-stage ,Metabolic syndrome ,business ,Body mass index - Abstract
Nan Sha,1,2,* Hao Xu,1,2,* Tao Chen,1,2,* Da-wei Tian,1,2 Wan-qin Xie,3 Lin-Guo Xie,1,2 Yu Zhang,1,2 Chen Xing,1,2 Xiao-teng Liu,1,2 Zhong-Hua Shen,1,2 Zhou-Liang Wu,1,2 Hai-Long Hu1,2 Chang-Li Wu1,2 1Department of Urology, The Second Hospital of Tianjin Medical University, 2Tianjin Key Laboratory of Urology, Tianjin Institute of Urology, Tianjin, 3Key Laboratory of Genetics and Birth Health of Hunan province, Family Planning Research Institute of Hunan Province, Changsha, Hunan, People’s Republic of China *These authors contributed equally tothis work Objective: The objective of this article was to summarize the relationship between some components of metabolic syndrome (MetS) and the histopathologic findings in bladder cancer in a Chinese population. Methods: We retrospectively analyzed data of 323 patients from the Department of Urology, Second Hospital of Tianjin Medical University between January 2012 and January 2014. All the patients were diagnosed with bladder cancer for the first time. Age, height, weight, histologic stage, grade, the presence of hypertension, diabetes mellitus, and body mass index were evaluated. The 2009 American Joint Committee on Cancer TNM staging system was used, with Ta and T1 tumors accepted as lower stage and T2, T3, and T4 tumors as higher stage bladder cancers. Also, pathologists assigned tumor grade according to the 1973 World Health Organization grading system. Noninvasive papillary urothelial neoplasms of low malignant potential were regarded as low grade. Analyses were completed using chi-square tests and logistic regression analysis. Results: Of the 323 patients, 164 had hypertension, 151 had diabetes mellitus, and 213 had a body mass index ≥25 kg/m2. MetS was significantly associated with histologic grade (P
- Published
- 2016
38. Intravenous chemotherapy combined with intravesical chemotherapy to treat T1G3 bladder urothelial carcinoma after transurethral resection of bladder tumor: results of a retrospective study
- Author
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Yungkai Qie, Hailong Hu, Yu Zhang, Linguo Xie, Hao Xu, Tao Chen, Changli Wu, Nan Sha, Zhouliang Wu, Chen Xing, Zhonghua Shen, Xiaoteng Liu, and Wanqin Xie
- Subjects
medicine.medical_specialty ,recurrence ,Bladder Urothelial Carcinoma ,030232 urology & nephrology ,Urology ,urologic and male genital diseases ,OncoTargets and Therapy ,Resection ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Bladder tumor ,Pharmacology (medical) ,Stage (cooking) ,bladder ,Original Research ,Bladder cancer ,intravenous chemotherapy ,business.industry ,Intravenous chemotherapy ,Retrospective cohort study ,medicine.disease ,Surgery ,Oncology ,030220 oncology & carcinogenesis ,progression ,Intravesical chemotherapy ,business - Abstract
Yu Zhang,1,* Linguo Xie,1,* Tao Chen,1,* Wanqin Xie,2 Zhouliang Wu,1 Hao Xu,1 Chen Xing,1 Nan Sha,1 Zhonghua Shen,1 Yunkai Qie,1 Xiaoteng Liu,1 Hailong Hu,1 Changli Wu1 1Department of Urology, The Second Hospital of Tianjin Medical University, Tianjin Institute of Urology, Tianjin, 2Key Laboratory of Genetics and Birth Health of Hunan Province, The Family Planning Research Institute of Hunan Province, Changsha, People’s Republic of China *These authors contributed equally to this work Objective: The management of stage 1 and grade 3 (T1G3) bladder cancer continues to be controversial. Although the transurethral resection of bladder tumor (TURBT) followed by intravesical chemotherapy is a conservative strategy for treatment of T1G3 bladder cancer, a relatively high risk of tumor recurrence and progression remains regarding the therapy. This study aimed to compare the efficacy of intravenous chemotherapy combined with intravesical chemotherapy versus intravesical chemotherapy alone for T1G3 bladder cancer after TURBT surgery. Methods: We retrospectively reviewed the cases of 457 patients who were newly diagnosed with T1G3 bladder urothelial carcinoma between January 2009 and March 2014. After TURBT, 281 patients received intravesical chemotherapy alone, whereas 176 patients underwent intravesical chemotherapy in combination with intravenous chemotherapy. Tumor recurrence and progression were monitored periodically by urine cytology and cystoscopy in follow-up. Recurrence-free survival and progression-free survival of the two chemotherapy strategies following TURBT were analyzed. Univariable and multivariable Cox hazards analyses were performed to predict the prognostic factors for tumor recurrence and progression. Results: The tumor recurrence rate was 36.7% for patients who received intravesical chemotherapy alone after TURBT, compared with 19.9% for patients who received intravenous chemotherapy combined with intravesical chemotherapy after TURBT (P
- Published
- 2016
39. Association between MDM2 SNP309 T>G polymorphism and the risk of bladder cancer: new data in a Chinese population and an updated meta-analysis
- Author
-
Hailong Hu, Ruifa Han, Yujuan Li, Dawei Tian, Yan Sun, Changli Wu, Na Ding, Xuewu Nian, Zhonghua Shen, Linguo Xie, Hao Xu, Yu Zhang, Nan Sha, and Tao Chen
- Subjects
Oncology ,medicine.medical_specialty ,recurrence ,Single-nucleotide polymorphism ,Bioinformatics ,OncoTargets and Therapy ,MDM2 ,single nucleotide polymorphism ,Internal medicine ,Genotype ,Genetic predisposition ,Medicine ,Pharmacology (medical) ,Original Research ,Bladder cancer ,business.industry ,Proportional hazards model ,Odds ratio ,medicine.disease ,Confidence interval ,meta-analysis ,rs2279744 ,Meta-analysis ,bladder cancer ,business - Abstract
Linguo Xie,1,2,* Yan Sun,2,* Tao Chen,1,2,* Dawei Tian,1,2 Yujuan Li,3 Yu Zhang,1,2 Na Ding,2 Zhonghua Shen,1,2 Hao Xu,1,2 Xuewu Nian,4 Nan Sha,1,2 Ruifa Han,1,2 Hailong Hu,1,2 Changli Wu1,2 Objective: Human murine double minute 2 protein (MDM2) is mainly a negative regulator of p53 tumor suppressor pathway. We aimed to investigate the association between MDM2 SNP309 polymorphism and bladder cancer risk. Methods: A total of 535 bladder cancer patients and 649 health controls were recruited for our study. MDM2 SNP309 T>G polymorphism was genotyped by polymerase chain reaction-ligase detection reaction method. Logistic regression was used to analyze the relationship between the genotype and susceptibility of bladder cancer. Kaplan–Meier estimates and log-rank test were obtained to analyze the association between the genotype and risk of recrudesce in nonmuscle-invasive bladder cancer patients. A multivariable Cox proportional hazards model was fitted to identify independent prognostic factors. To further investigate the association, we conducted a meta-analysis including six studies. Results: The frequency of the MDM2 SNP309 T>G polymorphism showed no significant difference between cases and controls (all P>0.05). In the stratification analysis, the results showed that G allele carriers were prone to have a significant decrease in risk of low-grade bladder cancer (adjusted odds ratio: 0.613, 95% confidence interval: 0.427–0.881), and G variant was associated with a significantly reduced risk of recurrence in nonmuscle-invasive bladder cancer patients with or without chemotherapy (P0.05). Conclusion: MDM2 SNP309 T>G polymorphism has no influence on bladder cancer risk in Asians, but this single nucleotide polymorphism may be associated with genetic susceptibility of bladder cancer among Caucasians. Keywords: bladder cancer, MDM2, single nucleotide polymorphism, rs2279744, recurrence, meta-analysis
- Published
- 2015
40. Impact of lymphovascular invasion on recurrence and progression rates in patients with pT1 urothelial carcinoma of bladder after transurethral resection
- Author
-
Hao Xu, Zhouliang Wu, Hailong Hu, Chen Xing, Xiaoteng Liu, Changli Wu, Yu Zhang, Linguo Xie, Nan Sha, Tao Chen, and Zhonghua Shen
- Subjects
bladder urothelial carcinoma ,Pathology ,medicine.medical_specialty ,recurrence ,Lymphovascular invasion ,Proportional hazards model ,business.industry ,Carcinoma in situ ,lymphovascular invasion ,Hazard ratio ,Urology ,Retrospective cohort study ,medicine.disease ,OncoTargets and Therapy ,Confidence interval ,TURBT ,Oncology ,medicine ,Pharmacology (medical) ,Clinical significance ,progression ,business ,Survival analysis ,Original Research - Abstract
Nan Sha,* Linguo Xie,* Tao Chen,* Chen Xing, Xiaoteng Liu, Yu Zhang, Zhonghua Shen, Hao Xu, Zhouliang Wu, Hailong Hu, Changli Wu Department of Urology, Tianjin Key Laboratory of Urology, Tianjin Institute of Urology, Second Hospital of Tianjin Medical University, Tianjin, People’s Republic of China *These authors contributed equally tothis work Objective: To evaluate the clinical significance of lymphovascular invasion (LVI) on recurrence and progression rates in patients with pT1 urothelial carcinoma of bladder after transurethral resection.Methods: This retrospective study was performed with 155 patients with newly diagnosed pT1 urothelial carcinoma of bladder who were treated with transurethral resection of bladder tumor at our institution from January 2006 to January 2010. The presence or absence of LVI was examined by pathologists. Chi-square test was performed to identify the correlations between LVI and other clinical and pathological features. Kaplan–Meier method was used to estimate the recurrence-free survival (RFS) and progression-free survival curves and difference was determined by the log-rank test. Univariate and multivariate analyses were performed to determine the predictive factors through a Cox proportional hazards analysis model.Results: LVI was detected in a total of 34 patients (21.9%). While LVI was associated with high-grade tumors (P
- Published
- 2015
41. Outage probability of two-way amplify-and-forward relaying system with interference-limited relay
- Author
-
Chunxiao Cai, Nan Sha, Yuemin Cai, Junchao Shen, and Weiwei Yang
- Subjects
Computer science ,business.industry ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Data_CODINGANDINFORMATIONTHEORY ,Outage probability ,Interference (wave propagation) ,Expression (mathematics) ,Power (physics) ,law.invention ,symbols.namesake ,Control theory ,Relay ,law ,Computer Science::Networking and Internet Architecture ,symbols ,Rayleigh scattering ,Telecommunications ,business ,Computer Science::Information Theory ,Rayleigh fading - Abstract
In the paper, we investigate the overall outage probability (OOP) of the two-way amplify-and-forward (AF) relaying systems in an interference-limited Rayleigh fading environment. More specifically, assuming the presence of Rayleigh faded multiple interferers at the AF relay and noisy sources, an approximate closed-form expression for the OOP are derived. In addition, it is shown that, in terms of the outage probability performance, the worst scenario appears to be the case with equal received-power interferers, for a given total received interference power in this system model. The analysis results are verified through comparison with the simulation results.
- Published
- 2011
42. Economic Model Analysis of Enterprise Brand after Introducing Personal Brand
- Author
-
Wenhua Yuan, Nan Sha, and Min Wang
- Subjects
Brand management ,business.industry ,Unit price ,Brand extension ,Demand curve ,Brand awareness ,Advertising ,Brand equity ,Price discrimination ,Marketing ,business ,Popularity - Abstract
Regarding the hospital as a special enterprise whose output is information, this article shows that the demand curve of the hospital rotates in a clockwise direction. That means the elasticity of the curve becomes lesser, which is useful for the hospital to implement the second-degree price discrimination. The reason is that the distribution of the unit price that the consumer willing to pay becomes more dispersed when the information outcome contains personal brand and enterprise brand. The combination of the personal brand (specialist brand, etc.) and product brand (drugs made-by-the-hospital, etc.) is the base of the hospital’s brand. This article analyzes the relationship among the three brands under a unified framework from the aspect of the product popularity. This article shows that the high product popularity cannot change into the actual sales revenue until the hospital obtains high product popularity by reflecting the consumer’s single profit point. Therefore, this article suggested the enterprise to focus on the single category of their products to get the consumers’ vote (i.e. currency).
- Published
- 2010
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