期刊文献+
共找到515,763篇文章
< 1 2 250 >
每页显示 20 50 100
Evaluation of the famous classic formula Sanhua decoction based on network pharmacology and multi-component quantitative analysis
1
作者 Xin Zhang Wan-Cui Wang +6 位作者 Jin-Kui Zhang Wei-Mei Zhang Peng-Wang Wang Peng-Cheng Lin Yong-Chang Lu Xia Li Wen-Yuan Gao 《Traditional Medicine Research》 2024年第1期1-13,共13页
Background:Sanhua decoction has significant effects in the treatment of stroke.The study of the Sanhua decoction material benchmark was carried out to analyze the value transfer relationship between the Chinese herbal... Background:Sanhua decoction has significant effects in the treatment of stroke.The study of the Sanhua decoction material benchmark was carried out to analyze the value transfer relationship between the Chinese herbal pieces and the substance benchmark.Methods:Network pharmacology was employed to investigate the potential active components and molecular mechanisms of Sanhua decoction in the treatment of stroke.15 batches of Sanhua decoction lyophilized powder were prepared using traditional formulas and subjected to high-performance liquid chromatography analysis to generate fingerprints of the Sanhua decoction substance benchmarks.Then,a multi-component quantitative analysis method was established,allowing for the simultaneous determination of ten components,to study the transfer of quantity values between pieces and substance benchmarks.Results:60 active ingredients were screened from Sanhua decoction by network pharmacology,of which gallic acid,magnolol honokiol,physcion,and aloe-emodin may have a greater effect than other active components.63 key targets and 134 pathways were predicted as the potential mechanism of Sanhua decoction in treating stroke.The fingerprint similarity of the Sanhua decoction substance benchmarks was found to be good among the 15 batches,confirming the 19 common peaks.The content of the 10 components was basically consistent.The components’transfer rates were within 30%of their respective means.Conclusions:This study provided a comprehensive and reliable strategy for the quality evaluation of Sanhua decoction substance benchmarks and held significant importance in improving its application value. 展开更多
关键词 Sanhua decoction classic famous formula HPLC fingerprinting value transfer network pharmacology
下载PDF
Application of virtual reality technology improves the functionality of brain networks in individuals experiencing pain
2
作者 Takahiko Nagamine 《World Journal of Clinical Cases》 SCIE 2025年第3期66-68,共3页
Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the u... Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the use of virtual reality(VR)technology.VR has been demonstrated to be an effective treatment for pain associated with medical procedures,as well as for chronic pain conditions for which no effective treatment has been established.The precise mechanism by which the diversion from reality facilitated by VR contributes to the diminution of pain and anxiety has yet to be elucidated.However,the provision of positive images through VR-based visual stimulation may enhance the functionality of brain networks.The salience network is diminished,while the default mode network is enhanced.Additionally,the medial prefrontal cortex may establish a stronger connection with the default mode network,which could result in a reduction of pain and anxiety.Further research into the potential of VR technology to alleviate pain could lead to a reduction in the number of individuals who overdose on painkillers and contribute to positive change in the medical field. 展开更多
关键词 Virtual reality PAIN ANXIETY Salience network Default mode network
下载PDF
Unlocking the future:Mitochondrial genes and neural networks in predicting ovarian cancer prognosis and immunotherapy response
3
作者 Zhi-Jian Tang Yuan-Ming Pan +2 位作者 Wei Li Rui-Qiong Ma Jian-Liu Wang 《World Journal of Clinical Oncology》 2025年第1期43-52,共10页
BACKGROUND Mitochondrial genes are involved in tumor metabolism in ovarian cancer(OC)and affect immune cell infiltration and treatment responses.AIM To predict prognosis and immunotherapy response in patients diagnose... BACKGROUND Mitochondrial genes are involved in tumor metabolism in ovarian cancer(OC)and affect immune cell infiltration and treatment responses.AIM To predict prognosis and immunotherapy response in patients diagnosed with OC using mitochondrial genes and neural networks.METHODS Prognosis,immunotherapy efficacy,and next-generation sequencing data of patients with OC were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus.Mitochondrial genes were sourced from the MitoCarta3.0 database.The discovery cohort for model construction was created from 70% of the patients,whereas the remaining 30% constituted the validation cohort.Using the expression of mitochondrial genes as the predictor variable and based on neural network algorithm,the overall survival time and immunotherapy efficacy(complete or partial response)of patients were predicted.RESULTS In total,375 patients with OC were included to construct the prognostic model,and 26 patients were included to construct the immune efficacy model.The average area under the receiver operating characteristic curve of the prognostic model was 0.7268[95% confidence interval(CI):0.7258-0.7278]in the discovery cohort and 0.6475(95%CI:0.6466-0.6484)in the validation cohort.The average area under the receiver operating characteristic curve of the immunotherapy efficacy model was 0.9444(95%CI:0.8333-1.0000)in the discovery cohort and 0.9167(95%CI:0.6667-1.0000)in the validation cohort.CONCLUSION The application of mitochondrial genes and neural networks has the potential to predict prognosis and immunotherapy response in patients with OC,providing valuable insights into personalized treatment strategies. 展开更多
关键词 Ovarian cancer MITOCHONDRIA PROGNOSIS IMMUNOTHERAPY Neural network
下载PDF
Resting-state brain network remodeling after different nerve reconstruction surgeries:a functional magnetic resonance imaging study in brachial plexus injury rats
4
作者 Yunting Xiang Xiangxin Xing +6 位作者 Xuyun Hua Yuwen Zhang Xin Xue Jiajia Wu Mouxiong Zheng He Wang Jianguang Xu 《Neural Regeneration Research》 SCIE CAS 2025年第5期1495-1504,共10页
Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network lev... Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network level have not been elucidated.This study aimed to explore intranetwork changes related to altered peripheral neural pathways after different nerve reconstruction surgeries,including nerve repair,endto-end nerve transfer,and end-to-side nerve transfer.Sprague–Dawley rats underwent complete left brachial plexus transection and were divided into four equal groups of eight:no nerve repair,grafted nerve repair,phrenic nerve end-to-end transfer,and end-to-side transfer with a graft sutured to the anterior upper trunk.Resting-state brain functional magnetic resonance imaging was obtained 7 months after surgery.The independent component analysis algorithm was utilized to identify group-level network components of interest and extract resting-state functional connectivity values of each voxel within the component.Alterations in intra-network resting-state functional connectivity were compared among the groups.Target muscle reinnervation was assessed by behavioral observation(elbow flexion)and electromyography.The results showed that alterations in the sensorimotor and interoception networks were mostly related to changes in the peripheral neural pathway.Nerve repair was related to enhanced connectivity within the sensorimotor network,while end-to-side nerve transfer might be more beneficial for restoring control over the affected limb by the original motor representation.The thalamic-cortical pathway was enhanced within the interoception network after nerve repair and end-to-end nerve transfer.Brain areas related to cognition and emotion were enhanced after end-to-side nerve transfer.Our study revealed important brain networks related to different nerve reconstructions.These networks may be potential targets for enhancing motor recovery. 展开更多
关键词 brain functional networks end-to-end nerve transfer end-to-side nerve transfer independent component analysis nerve repair peripheral plexus injury resting-state functional connectivity
下载PDF
MULTI-CLASS TRAFFIC QOS ROUTING FOR LEO SATELLITE NETWORKS 被引量:3
5
作者 蒋文娟 宗鹏 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第3期254-262,共9页
Due to the diversified demands of quality of service(QoS) in volume multimedia application, QoS routings for multiservice are becoming a research hotspot in low earth orbit(LEO) satellite networks. A novel QoS sat... Due to the diversified demands of quality of service(QoS) in volume multimedia application, QoS routings for multiservice are becoming a research hotspot in low earth orbit(LEO) satellite networks. A novel QoS satellite routing algorithm for multi-class traffic is proposed. The goal of the routing algorithm is to provide the distinct QoS for different traffic classes and improve the utilization of network resources. Traffic is classified into three classes and allocated priorities based on their QoS requirements, respectively. A priority queuing mechanism guarantees the algorithm to work better for high-priority classes. In order to control the congestion, a blocking probability analysis model is built up based on the Markov process theory. Finally, according to the classification link-cost metrics, routings for different classes are calculated with the distinct QoS requirments and the status of network resource. Simulations verify the performance of the routing algorithm at different time and in different regions, and results demonstrate that the algorithm has great advantages in terms of the average delay and the blocking probability. Meanwhile, the robustness issue is also discussed. 展开更多
关键词 low earth orbit satellite networks traffic classification routing algorithm quality of service traffic and topology model
下载PDF
A maximum-independent-set-based channel allocation algorithm for multi-channel wireless networks
6
作者 余旭涛 施小翔 曾绍祥 《Journal of Southeast University(English Edition)》 EI CAS 2015年第1期12-18,共7页
A channel allocation algorithm based on the maximum independent set is proposed to decrease network conflict and improve network performance. First, a channel allocation model is formulated and a series of the maximum... A channel allocation algorithm based on the maximum independent set is proposed to decrease network conflict and improve network performance. First, a channel allocation model is formulated and a series of the maximum independent sets (MISs) are obtained from a contention graph by the proposed approximation algorithm with low complexity. Then, a weighted contention graph is obtained using the number of contention vertices between two MISs as a weighted value. Links are allocated to channels by the weighted contention graph to minimize conflicts between independent sets. Finally, after channel allocation, each node allocates network interface cards (NICs) to links that are allocated channels according to the queue lengths of NICs. Simulations are conducted to evaluate the proposed algorithm. The results show that the proposed algorithm significantly improves the network throughput and decreases the end to end delay. 展开更多
关键词 wireless networks multi-cHANNEL channelaUocation maximum independent set
下载PDF
Multi-constraint quality of service routing algorithm for dynamic topology networks 被引量:3
7
作者 Wang Ping Chen Bingcai +1 位作者 Gu Xuemai Liu Gongliang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第1期58-64,共7页
An adaptive multi-QoS routing algorithm called AMQRA is proposed for dynamic topology networks, such as satellite networks and Ad-hoc networks. The AMQRA is a distributed and mobile-agents-based routing algorithm, whi... An adaptive multi-QoS routing algorithm called AMQRA is proposed for dynamic topology networks, such as satellite networks and Ad-hoc networks. The AMQRA is a distributed and mobile-agents-based routing algorithm, which combines ant quantity system (AQS) with ant colony optimization (ACO) that is used in AntNet routing algorithm. In dynamic topology networks, the AMQRA achieves timely optimization for concave metric QoS constraint and fast convergence. The proposed routing algorithm is simulated in Iridium satellite constellation on OPNET. The results show that AMQRA not only outperforms the AntNet in convergence rate in dynamic topology networks but also can optimize concave metric QoS constraint and reasonably allot bandwidth to the load to avoid networks congestion. 展开更多
关键词 ROUTING QOS dynamic topology networks
下载PDF
A Dormant Multi-Controller Model for Software Defined Networking 被引量:11
8
作者 FU Yonghong BI Jun +3 位作者 WU Jianping CHEN Ze WANG Ke LUO Min 《China Communications》 SCIE CSCD 2014年第3期45-55,共11页
In order to improve the scalability and reliability of Software Defined Networking(SDN),many studies use multiple controllers to constitute logically centralized control plane to provide load balancing and fail over.I... In order to improve the scalability and reliability of Software Defined Networking(SDN),many studies use multiple controllers to constitute logically centralized control plane to provide load balancing and fail over.In this paper,we develop a flexible dormant multi-controller model based on the centralized multi-controller architecture.The dormant multi-controller model allows part of controllers to enter the dormant state under light traffic condition for saving system cost.Meanwhile,through queueing analysis,various performance measures of the system can be obtained.Moreover,we analyze the real traffic of China Education Network and use the results as the parameters of computer simulation and verify the effects of parameters on the system characteristics.Finally,a total expected cost function is established,and genetic algorithm is employed to find the optimal values of various parameters to minimize system cost for the deployment decision making. 展开更多
关键词 Software Defined networking multi-cONTROLLER queueing theory PERFORMANCEEVALUATION
下载PDF
Centralized Quasi-Static Channel Assignment for Multi-Radio Multi-Channel Wireless Mesh Networks 被引量:3
9
作者 Juan REN Zhengding QIU 《Wireless Sensor Network》 2009年第2期104-111,共8页
Employing multiple channels in wireless multihop networks is regarded as an effective approach to increas-ing network capacity. This paper presents a centralized quasi-static channel assignment for multi-radio multi-c... Employing multiple channels in wireless multihop networks is regarded as an effective approach to increas-ing network capacity. This paper presents a centralized quasi-static channel assignment for multi-radio multi-channel Wireless Mesh Networks (WMNs). The proposed channel assignment can efficiently utilize multiple channels with only 2 radios equipped on each mesh router. In the scheme, the network end-to-end traffics are first modeled by probing data at wireless access points, and then the traffic load between each pair of neighboring routers is further estimated using an interference-aware estimation algorithm. Having knowledge of the expected link load, the scheme assigns channels to each radio with the objective of mini-mizing network interference, which as a result greatly improves network capacity. The performance evalua-tion shows that the proposed scheme is highly responsive to varying traffic conditions, and the network per-formance under the channel assignment significantly outperforms the single-radio IEEE 802.11 network as well as the 2-radio WMN with static 2 channels. 展开更多
关键词 Wireless Mesh networks MULTIHOP network Channel ASSIGNMENT MULTI-RADIO
下载PDF
Synthesis of Multi-component Mass-exchange Networks 被引量:5
10
作者 刘琳琳 都健 +2 位作者 Mahmoud M. EI-Halwagi Jose Maria Ponce-Ortega 姚平经 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第4期376-381,共6页
This paper presents a superstructure-based formulation for the synthesis of mass-exchange networks (MENs) considering multiple components. The superstructure is simplified by directly using the mass separation agents ... This paper presents a superstructure-based formulation for the synthesis of mass-exchange networks (MENs) considering multiple components. The superstructure is simplified by directly using the mass separation agents (MSA) from their sources, and therefore the automatic synthesis of the multi-component system involved in the MENs can be achieved without choosing a 'key-component' either for the whole process or the mass exchangers. A mathematical model is proposed to carry out the optimization process. The concentrations, flow rates, matches and unit operation displayed in the obtained network constitute the exact representation of the mass exchange process in terms of all species in the system. An example is used to illustrate and demonstrate the application of the proposed method. 展开更多
关键词 multiple components mass exchange network SUPERSTRUCTURE OPTIMIZATION
下载PDF
Joint channel assignment and cross-layer routing protocol for multi-radio multi-channel Ad Hoc networks 被引量:2
11
作者 Yang Lu Junming Guan +1 位作者 Zhen Wei Qilin Wu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第6期1095-1102,共8页
To study multi-radio multi-channel (MR-MC) Ad Hoc networks based on 802.11, an efficient cross-layer routing protocol with the function of joint channel assignment, called joint channel assignment and cross-layer ro... To study multi-radio multi-channel (MR-MC) Ad Hoc networks based on 802.11, an efficient cross-layer routing protocol with the function of joint channel assignment, called joint channel assignment and cross-layer routing (JCACR), is presented. Firstly, this paper introduces a new concept called channel utilization percentage (CUP), which is for measuring the contention level of different channels in a node’s neighborhood, and deduces its optimal value for determining whether a channel is overloaded or not. Then, a metric parameter named channel selection metric (CSM) is designed, which actually reffects not only the channel status but also corresponding node’s capacity to seize it. JCACR evaluates channel assignment by CSM, performs a local optimization by assigning each node a channel with the smaller CSM value, and changes the working channel dynamically when the channel is overloaded. Therefore, the network load balancing can be achieved. In addition, simulation shows that, when compared with the protocol of weighted cumulative expected transfer time (WCETT), the new protocol can improve the network throughput and reduce the end-to-end average delay with fewer overheads. 展开更多
关键词 Ad Hoc network multi-radio multi-channel channel assignment routing protocol channel utilization percentage.
下载PDF
Incorporating Network Coding into TCP Grounded on Network Utility Maximization in Multi-Radio Multi-Channel Wireless Mesh Networks 被引量:1
12
作者 Liu Hongquan Gu Yuantao 《China Communications》 SCIE CSCD 2012年第6期28-35,共8页
A new approach, named TCP-I2NC, is proposed to improve the interaction between network coding and TCP and to maximize the network utility in interference-free multi-radio multi-channel wireless mesh networks. It is gr... A new approach, named TCP-I2NC, is proposed to improve the interaction between network coding and TCP and to maximize the network utility in interference-free multi-radio multi-channel wireless mesh networks. It is grounded on a Network Utility Maxmization (NUM) formulation which can be decomposed into a rate control problem and a packet scheduling problem. The solutions to these two problems perform resource allocation among different flows. Simulations demonstrate that TCP-I2NC results in a significant throughput gain and a small delay jitter. Network resource is fairly allocated via the solution to the NUM problem and the whole system also runs stably. Moreover, TCP-I2NC is compatible with traditional TCP variants. 展开更多
关键词 network utility maximization net-work coding wireless mesh network TCP
下载PDF
ICI Management for Efficient Radio Resource Allocation in Multi-Cell OFDMA Networks 被引量:1
13
作者 吕铁军 余雪芬 《China Communications》 SCIE CSCD 2011年第7期84-94,共11页
Two Inter-cell Interference (ICI) management algorithms: Primary Interference Balancing (PIB) algorithm and Interfering Bits Loading Avoidance (IBLA) algorithm are proposed for canceling the ICI effects which the exis... Two Inter-cell Interference (ICI) management algorithms: Primary Interference Balancing (PIB) algorithm and Interfering Bits Loading Avoidance (IBLA) algorithm are proposed for canceling the ICI effects which the existing efficient radio resource allocation algorithms do not consider. The efficient radio resource allocation algorithm, i.e., Pre-assignment and Reassignment (PR) algorithm, obtains the lowest complexity and achieves good throughput performance in single cell OFDMA system. However, in multi-cell multi-sector OFDMA networks, PR algorithm is not applicable because it does not take ICI into consideration. The proposed PIB algorithm balances the number of loading bits for the desired User Equipment (UE) and the major interfering UE, as well as optimizes the SINR performance; meanwhile, IBLA avoids loading certain number of interfering bits which would make SINR unqualified. Simulations confirm the ICI management effectiveness and feasibility of both the proposals. 展开更多
关键词 ICI management bit loading integer programming radio resource allocation multi-cell OFDMA networks
下载PDF
Multi-channel electromyography pattern classification using deep belief networks for enhanced user experience 被引量:1
14
作者 SHIM Hyeon-min LEE Sangmin 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第5期1801-1808,共8页
An enhanced algorithm is proposed to recognize multi-channel electromyography(EMG) patterns using deep belief networks(DBNs). It is difficult to classify the EMG features because an EMG signal has nonlinear and time-v... An enhanced algorithm is proposed to recognize multi-channel electromyography(EMG) patterns using deep belief networks(DBNs). It is difficult to classify the EMG features because an EMG signal has nonlinear and time-varying characteristics.Therefore, in several previous studies, various machine-learning methods have been applied. A DBN is a fast, greedy learning algorithm that can find a fairly good set of weights rapidly, even in deep networks with a large number of parameters and many hidden layers. To evaluate this model, we acquired EMG signals, extracted their features, and then compared the model with the DBN and other conventional classifiers. The accuracy of the DBN is higher than that of the other algorithms. The classification performance of the DBN model designed is approximately 88.60%. It is 7.55%(p=9.82×10-12) higher than linear discriminant analysis(LDA) and 2.89%(p=1.94×10-5) higher than support vector machine(SVM). Further, the DBN is better than shallow learning algorithms or back propagation(BP), and this model is effective for an EMG-based user-interfaced system. 展开更多
关键词 electromyography(EMG) pattern classification feature extraction deep learning deep belief network(DBN)
下载PDF
A new multi-channel MAC protocol based on CDMA for ad hoc networks 被引量:1
15
作者 贾旻 陈惠民 袁玉华 《Journal of Shanghai University(English Edition)》 CAS 2007年第2期174-177,共4页
This paper proposes a novel multichannel medium access control (MAC) protocol based on CDMA that improves network performance and reduces collision probability in wireless ad hoc networks. In the scheme, the code ch... This paper proposes a novel multichannel medium access control (MAC) protocol based on CDMA that improves network performance and reduces collision probability in wireless ad hoc networks. In the scheme, the code channel is divided into common channel, broadcast channel and several data channels. Simulation results show that the proposed protocol can achieve significantly better performance than the IEEE 802.11 standard. 展开更多
关键词 ad hoc networks medium access control (MAC) protocol MULTICHANNEL CDMA
下载PDF
Multi-Classification of Polyps in Colonoscopy Images Based on an Improved Deep Convolutional Neural Network 被引量:1
16
作者 Shuang Liu Xiao Liu +9 位作者 Shilong Chang Yufeng Sun Kaiyuan Li Ya Hou Shiwei Wang Jie Meng Qingliang Zhao Sibei Wu Kun Yang Linyan Xue 《Computers, Materials & Continua》 SCIE EI 2023年第6期5837-5852,共16页
Achieving accurate classification of colorectal polyps during colonoscopy can avoid unnecessary endoscopic biopsy or resection.This study aimed to develop a deep learning model that can automatically classify colorect... Achieving accurate classification of colorectal polyps during colonoscopy can avoid unnecessary endoscopic biopsy or resection.This study aimed to develop a deep learning model that can automatically classify colorectal polyps histologically on white-light and narrow-band imaging(NBI)colonoscopy images based on World Health Organization(WHO)and Workgroup serrAted polypS and Polyposis(WASP)classification criteria for colorectal polyps.White-light and NBI colonoscopy images of colorectal polyps exhibiting pathological results were firstly collected and classified into four categories:conventional adenoma,hyperplastic polyp,sessile serrated adenoma/polyp(SSAP)and normal,among which conventional adenoma could be further divided into three sub-categories of tubular adenoma,villous adenoma and villioustublar adenoma,subsequently the images were re-classified into six categories.In this paper,we proposed a novel convolutional neural network termed Polyp-DedNet for the four-and six-category classification tasks of colorectal polyps.Based on the existing classification network ResNet50,Polyp-DedNet adopted dilated convolution to retain more high-dimensional spatial information and an Efficient Channel Attention(ECA)module to improve the classification performance further.To eliminate gridding artifacts caused by dilated convolutions,traditional convolutional layers were used instead of the max pooling layer,and two convolutional layers with progressively decreasing dilation were added at the end of the network.Due to the inevitable imbalance of medical image data,a regularization method DropBlock and a Class-Balanced(CB)Loss were performed to prevent network overfitting.Furthermore,the 5-fold cross-validation was adopted to estimate the performance of Polyp-DedNet for the multi-classification task of colorectal polyps.Mean accuracies of the proposed Polyp-DedNet for the four-and six-category classifications of colorectal polyps were 89.91%±0.92%and 85.13%±1.10%,respectively.The metrics of precision,recall and F1-score were also improved by 1%∼2%compared to the baseline ResNet50.The proposed Polyp-DedNet presented state-of-the-art performance for colorectal polyp classifying on white-light and NBI colonoscopy images,highlighting its considerable potential as an AI-assistant system for accurate colorectal polyp diagnosis in colonoscopy. 展开更多
关键词 Colorectal polyps four-and six-category classifications convolutional neural network dilated residual network
下载PDF
Cognitive Radio Ad-Hoc Networks: Some New Results on Multi-Channel Hidden Terminal Problem 被引量:1
17
作者 Palaniandavar Venkateswaran Srishti Shaw +1 位作者 Sandhya Pattanayak Rabindranath Nandi 《Communications and Network》 2012年第4期342-348,共7页
Recently the Cognitive Radio (CR), in particular the CR Ad-Hoc Network (CRAHN) technology appears as a burgeoning area in wireless communication that enables utilization of limited network resources in more efficient ... Recently the Cognitive Radio (CR), in particular the CR Ad-Hoc Network (CRAHN) technology appears as a burgeoning area in wireless communication that enables utilization of limited network resources in more efficient and intelligent way;studies indicate that opportunistic utilization of the available radio frequency spectrum, without interfering the licensed primary user (PU) could be made. This paper presents some simulation based performance of the Multi-Channel Hidden Terminal (MCHT) problem on CRAHNs;new observations on the effect of the number of channels on certain PU-activity metrics, e.g., delay and throughput, are described. 展开更多
关键词 COGNITIVE AD-HOC networks MCHT Problem WIRELESS Communication NS-2
下载PDF
Quality evaluation of Pinelliae Rhizoma using network pharmacology and multi-component quantitative analysis 被引量:1
18
作者 Xin-Yang Li Di Liang +6 位作者 Xue-Qian Zhang Xiao-Huan Li Miao Sha Xue-Ming Zhang Lan-Ping Guo Wen-Yuan Gao Xia Li 《Traditional Medicine Research》 2022年第4期17-26,共10页
Background:Pinelliae Rhizoma(Banxia)is a valuable traditional Chinese medicine,and its quality issues are related to the safety and effectiveness of the medicine.Several pharmacological experiments have shown that Pin... Background:Pinelliae Rhizoma(Banxia)is a valuable traditional Chinese medicine,and its quality issues are related to the safety and effectiveness of the medicine.Several pharmacological experiments have shown that Pinelliae Rhizoma has anti-inflammatory activity,but the specific chemical components remain unclear.Methods:In the present study,network pharmacology was used to analyze the potential active ingredients and molecular mechanisms of Pinelliae Rhizoma’s anti-inflammatory activity.A new approach to simultaneously determine eight components using high performance liquid chromatography-photo-diode array was developed to evaluate the quality of Pinelliae Rhizoma and different processed Pinelliae Rhizoma products.Results:Twelve active ingredients were identified from Pinelliae Rhizoma,andβ-sitosterol may have a greater effect than the other active ingredients.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed the main pathways associated with Pinelliae Rhizoma’s mechanism for treating inflammation.Additionally,theβ-sitosterol content in different processed Pinelliae Rhizoma products decreased significantly,and the level of five nucleosides in Pinelliae Rhizoma was significantly higher than that of the processed Pinelliae Rhizoma products.The 6-gingerol content was detected in eight Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine batches with different origins,and liquiritin and liquiritigenin levels were detected in eight batches of Pinelliae Rhizoma Praeparatum with different origins.Conclusion:Pinelliae Rhizoma quality was affected by different regions and different processing methods,and this research provides a reference for Pinelliae Rhizoma quality evaluation. 展开更多
关键词 Pinelliae Rhizoma ANTI-INFLAMMATION network pharmacology HPLC quality evaluation
下载PDF
Joint Link Allocation and Rate Assignment Algorithm for Multi-Channel Wireless Networks 被引量:1
19
作者 Yu Xutao Fang Xin Zhang Zaichen 《China Communications》 SCIE CSCD 2012年第9期96-106,共11页
This paper presents a link allocation and rate assignment algorithm for multi-channel wireless networks. The objective is to reduce network con-flicts and guarantee the fairness among links. We first design a new netw... This paper presents a link allocation and rate assignment algorithm for multi-channel wireless networks. The objective is to reduce network con-flicts and guarantee the fairness among links. We first design a new network model. With this net-work model, the multi-channel wireless network is divided into several subnets according to the num-ber of channels. Based on this, we present a link allocation algorithm with time complexity O(l^2)to al-locate all links to subnets. This link allocation algo-rithm adopts conflict matrix to minimize the network contention factor. After all links are allocated to subnets, the rate assignment algorithm to maximize a fairness utility in each subnet is presented. The rate assignment algorithm adopts a near-optirml al-gorithm based on dual decomposition and realizes in a distributed way. Simulation results demonstrate that, compared with IEEE 802.11b and slotted see-ded channel hopping algorithm, our algorithm de-creases network conflicts and improves the net-work throughput significantly. 展开更多
关键词 multi-channel networks link allocation rate assignment conflict matrix fairness utilityfunction
下载PDF
Using multi-class queuing network to solve performance models of e-business sites 被引量:1
20
作者 郑小盈 陈德人 《Journal of Zhejiang University Science》 EI CSCD 2004年第1期31-39,共9页
Due to e-business' s variety of customers with different navigational patterns and demands, multiclass queuing network is a natural performance model for it. The open multi-class queuing network(QN) models are bas... Due to e-business' s variety of customers with different navigational patterns and demands, multiclass queuing network is a natural performance model for it. The open multi-class queuing network(QN) models are based on the assumption that no service center is saturated as a result of the combined loads of all the classes. Several formulas are used to calculate performance measures, including throughput, residence time, queue length, response time and the average number of requests. The solution technique of closed multi-class QN models is an approximate mean value analysis algorithm (MVA) based on three key equations, because the exact algorithm needs huge time and space requirement. As mixed multi-class QN models, include some open and some closed classes, the open classes should be eliminated to create a closed multi-class QN so that the closed model algorithm can be applied. Some corresponding examples are given to show how to apply the algorithms mentioned in this article. These examples indicate that multi-class QN is a reasonably accurate model of e-business and can be solved efficiently. 展开更多
关键词 Queuing network (QN) Multi class Performance E business
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部