期刊文献+
共找到30篇文章
< 1 2 >
每页显示 20 50 100
A Context-Based Analgesia Model in Rats: Involvement of Prefrontal Cortex 被引量:4
1
作者 Lingchi Xu Yalan Wan +5 位作者 Longyu Ma Jie Zheng Bingxuan Han Feng-Yu Liu Ming Yi You Wan 《Neuroscience Bulletin》 SCIE CAS CSCD 2018年第6期1047-1057,共11页
Cognition and pain share common neural substrates and interact reciprocally: chronic pain compromises cognitive performance, whereas cognitive processes modulate pain perception. In the present study, we established a... Cognition and pain share common neural substrates and interact reciprocally: chronic pain compromises cognitive performance, whereas cognitive processes modulate pain perception. In the present study, we established a non-drug-dependent rat model of context-based analgesia,where two different contexts(dark and bright) were matched with a high(52°C) or low(48°C) temperature in the hot-plate test during training. Before and after training,we set the temperature to the high level in both contexts.Rats showed longer paw licking latencies in trials with the context originally matched to a low temperature than those to a high temperature, indicating successful establishment of a context-based analgesic effect in rats. This effect was blocked by intraperitoneal injection of naloxone(an opioid receptor antagonist) before the probe. The context-based analgesic effect also disappeared after optogenetic activation or inhibition of the bilateral infralimbic or prelimbic sub-region of the prefrontal cortex. In brief, we established a context-based, non-drug dependent, placebo-like analgesia model in the rat. This model provides a new and useful tool for investigating the cognitive modulation of pain. 展开更多
关键词 context-based analgesia Placebo analgesia Pain Hot-plate test Cognition modulation Opioid system Prefrontal cortex
原文传递
Effectiveness of Context-Based Strategy for English Learning among Chinese Middle School Students
2
作者 Yibu Luo Xiangting Chen 《Journal of Contemporary Educational Research》 2021年第9期61-70,共10页
Currently,a growing number of educators are aware of the need to look for new approaches to replace the"spoon-feeding"method.Therefore,the context-based strategy began to emerge.This study aims to investigat... Currently,a growing number of educators are aware of the need to look for new approaches to replace the"spoon-feeding"method.Therefore,the context-based strategy began to emerge.This study aims to investigate how students derive information through contextual clues by examining the progress of Chinese middle school EFL students in terms of word recognition.The participants of this study included 20 eighth grade students from the same middle school.The participants sat for two different quizzes:a contextual vocabulary quiz(quiz A)and a direct instruction quiz(quiz B).In quiz A,the participants inferred the meaning of the target words from the example sentences,whereas in quiz B,the students utilized the accompanying English explanation to guess other new words.These students were in the experimental and control conditions,respectively.The two quizzes comprised of 15 multiple choice questions(MCQ)which differentiated the participants?word recognition response to two different learning methods.There were two significant findings from this study.First,the results showed that the context-based strategy leads to a better vocabulary learning performance compared to the direct instruction strategy.Second,although it is not as effective as the context-based strategy,the direct instruction strategy may assist EFL learners in remembering words in short term. 展开更多
关键词 context-based strategy Context clues instruction Word recognition Direct instruction Contextual analysis
在线阅读 下载PDF
CBAC访问控制技术 被引量:2
3
作者 周铜 《中州大学学报》 2003年第2期125-126,共2页
本文介绍了基于上下文的访问控制技术CBAC,在路邮器中使用它,不但可以防止非法用户的侵入,而且能够有效的防止SYN等攻击,再结合其他的控制措施,可以有效的加强网络的安全性能。
关键词 访问控制技术 SYN 攻击 上下文 网络 用户 使用
在线阅读 下载PDF
SDBatis:基于MyBatis和CBAC的数据库应用访问控制 被引量:11
4
作者 叶茂林 余发江 《武汉大学学报(理学版)》 CAS CSCD 北大核心 2022年第1期57-64,共8页
大部分应用都以数据库作为数据保存的工具,由于应用的日益复杂,现有的访问控制机制存在安全性不高、开发繁琐,难以维护等问题。为此,本文提出一种新访问控制系统SDBatis。SDBatis以CBAC(Context-Based Access Control,基于上下文的访问... 大部分应用都以数据库作为数据保存的工具,由于应用的日益复杂,现有的访问控制机制存在安全性不高、开发繁琐,难以维护等问题。为此,本文提出一种新访问控制系统SDBatis。SDBatis以CBAC(Context-Based Access Control,基于上下文的访问控制)作为访问控制模型,使用MyBatis插件开发,定义了SDBatis中的访问控制策略。在保证访问控制功能模块独立的前提下,只需在持久层制定访问控制策略、配置获取当前应用用户上下文属性就能够完成访问控制工作;SDBatis支持基于上下文的访问控制和对数据库的行级访问控制。本文实现了SDBatis的一个原型,并对SDBatis进行了测试。测试结果表明,SDBatis降低了访问控制开发的成本,能适应动态变化的访问环境,保证数据库内数据的安全,且增加的访问控制时间在可接受范围内。 展开更多
关键词 访问控制 数据库 MyBatis cbac(context-based access control)
原文传递
基于路由器的CBAC流量监控技术的分析与实现
5
作者 张治元 《长沙通信职业技术学院学报》 2008年第4期28-30,共3页
拒绝服务攻击占用路由器和带宽的资源,导致网络和设备过载,是目前网络安全最主要的威胁之一。文章针对SYN flood拒绝服务攻击威胁,分析了CBAC的工作机制,提出了在Intranet和Internet的边界点,基于路由器的CBAC安全特性来监控网络流量这... 拒绝服务攻击占用路由器和带宽的资源,导致网络和设备过载,是目前网络安全最主要的威胁之一。文章针对SYN flood拒绝服务攻击威胁,分析了CBAC的工作机制,提出了在Intranet和Internet的边界点,基于路由器的CBAC安全特性来监控网络流量这一种简便、有效、实用的解决方法,搭建了实验网并在实验网环境下加以实现和验证。 展开更多
关键词 拒绝服务攻击 SYN FLOOD攻击 流量监控 cbac
在线阅读 下载PDF
基于CBAC防火墙对HTTP的JAVA插件智能过滤的研究和实践
6
作者 马朝辉 《电脑知识与技术》 2014年第11期7493-7494,7522,共3页
随着互联网的发展,网络安全日益重要。如何借助防火墙保护网络内部信息的安全已经成为当前的重要课题。该文研究基于CBAC防火墙的配置实现对应用层HTTP协议的JAVA插件智能过滤。实验结果表明,该文提出的配置方案能有效实施JAVA插件过滤... 随着互联网的发展,网络安全日益重要。如何借助防火墙保护网络内部信息的安全已经成为当前的重要课题。该文研究基于CBAC防火墙的配置实现对应用层HTTP协议的JAVA插件智能过滤。实验结果表明,该文提出的配置方案能有效实施JAVA插件过滤,从而避免一些网站上恶意的JAVA插件对内部造成的潜在安全威胁。 展开更多
关键词 cbac防火墙 HTTP协议 JAVA插件 过滤
在线阅读 下载PDF
CBAC安全特性及其网络安全解决方案
7
作者 陈海鸿 《中国金融电脑》 2001年第10期54-56,共3页
关键词 cbac 安全特性 金融网络 计算机网络 网络安全 防火墙
在线阅读 下载PDF
Methodology for predicting material performance by context-based modeling:A case study on solid amine CO_(2) adsorbents
8
作者 Shuangjun Li Zhixin Huang +2 位作者 Yuanming Li Shuai Deng Xiangkun Elvis Cao 《Energy and AI》 2025年第2期36-44,共9页
Traditional materials informatics leverages big data and machine learning(ML)to forecast material performance based on structural features but often overlooks valuable textual information.In this work,we proposed a no... Traditional materials informatics leverages big data and machine learning(ML)to forecast material performance based on structural features but often overlooks valuable textual information.In this work,we proposed a novel methodology for predicting material performance through context-based modeling using large language models(LLMs).This method integrates both numerical and textual information,enhancing predictive accuracy and scalability.In the case study,the approach is applied to predict the performance of solid amine CO_(2) adsorbents under direct air capture(DAC)conditions.ChatGPT 4o model was used to employ in-context learning to predict CO_(2) adsorption uptake based on input features,including material properties and experimental conditions.The results show that context-based modeling can reduce prediction error in comparison to traditional ML models in the prediction task.We adopted Sapley Additive exPlanations(SHAP)to further elucidate the importance of various input features.This work highlights the potential of LLMs in materials science,offering a cost-effective,efficient solution for complex predictive tasks. 展开更多
关键词 Materials informatics Machine learning Large language models context-based modeling Solid amines Direct air capture
在线阅读 下载PDF
基于Packet Tracer软件的防火墙技术实验教学设计 被引量:3
9
作者 姜恩华 李素文 +1 位作者 赵庆平 汪徐德 《通化师范学院学报》 2013年第8期45-47,共3页
借助Packet Tracer5.3.2完成防火墙技术的实验教学,以访问控制列表ACL、基于上下文的访问控制CBAC和基于区域的防火墙技术ZFW为线索,分析了实验教学案例的编写步骤.学生通过完成仿真实验,锻炼了配置防火墙技术的能力,加深了对防火墙技... 借助Packet Tracer5.3.2完成防火墙技术的实验教学,以访问控制列表ACL、基于上下文的访问控制CBAC和基于区域的防火墙技术ZFW为线索,分析了实验教学案例的编写步骤.学生通过完成仿真实验,锻炼了配置防火墙技术的能力,加深了对防火墙技术的掌握与理解,提高了防火墙技术实验教学的有效性. 展开更多
关键词 Packet TRACER 访问控制列表 cbac ZFW
在线阅读 下载PDF
CuCl催化剂负载于改性煤基活性炭载体后在合成碳酸二甲酯时的催化性能
10
作者 李瑞 赵天生 《机械工程材料》 CAS CSCD 北大核心 2012年第9期61-64,共4页
在采用甲醇气相氧化羰化工艺合成碳酸二甲酯(DMC)的过程中,以活化改性后的煤基活性炭(CBAC)为载体用浸渍法负载CuCl催化剂,研究了活化剂种类、活化温度、活化剂与CBAC物质的量比对催化剂活性的影响。结果表明:在活化剂为CuCl_2、活化温... 在采用甲醇气相氧化羰化工艺合成碳酸二甲酯(DMC)的过程中,以活化改性后的煤基活性炭(CBAC)为载体用浸渍法负载CuCl催化剂,研究了活化剂种类、活化温度、活化剂与CBAC物质的量比对催化剂活性的影响。结果表明:在活化剂为CuCl_2、活化温度为800℃、活化剂与CBAC物质的量比为1:1的条件下,改性CBAC载体制备的催化剂活性最好,甲醇转化率、DMC选择性、DMC时空收率可分别达到34.6%,96.4%,221.1 g·kg^(-1)·h^(-1)。 展开更多
关键词 cbac改性 碳酸二甲酯 负载CuCl催化剂
在线阅读 下载PDF
基于上下文的控制策略在网络安全中的实现
11
作者 周铜 周文洲 《电脑知识与技术》 2008年第3期1226-1228,共3页
虽然IPV6网络已经广泛进入试验阶段,但还没有真正普及使用,IPV4的安全,仍然是人们的重要工作。路由器作为保护网络的前沿阵地.有着相当出色的防御能力,我们通过试验,研究了基于上下文的访问控制技术CBAC的应用,它不但可以防止非... 虽然IPV6网络已经广泛进入试验阶段,但还没有真正普及使用,IPV4的安全,仍然是人们的重要工作。路由器作为保护网络的前沿阵地.有着相当出色的防御能力,我们通过试验,研究了基于上下文的访问控制技术CBAC的应用,它不但可以防止非法用户的侵入,而且能够有效的防止SYN等攻击,再结合其它的控制措施,可以有效的加强网络的安全性能。 展开更多
关键词 网络安全 访问控制 cbac
在线阅读 下载PDF
Context-Based 2D-VLC Entropy Coder in AVS Video Coding Standard 被引量:8
12
作者 王强 赵德斌 高文 《Journal of Computer Science & Technology》 SCIE EI CSCD 2006年第3期315-322,共8页
In this paper, a Context-based 2D Variable Length Coding (C2DVLC) method for coding the transformed residuals in AVS video coding standard is presented. One feature in C2DVLC is the usage of multiple 2D-VLC tables a... In this paper, a Context-based 2D Variable Length Coding (C2DVLC) method for coding the transformed residuals in AVS video coding standard is presented. One feature in C2DVLC is the usage of multiple 2D-VLC tables and another feature is the usage of simple Exponential-Golomb codes. C2DVLC employs context-based adaptive multiple table coding to exploit the statistical correlation between DCT coefficients of one block for higher coding efficiency. ExpGolomb codes are applied to code the pairs of the run-length of zero coefficients and the nonzero coefficient for lower storage requirement. C2DVLC is a low complexity coder in terms of both computational time and memory requirement. The experimental results show that C2DVLC can gain 0.34dB in average for the tested videos when compared with the traditional 2D-VLC coding method like that used in MPEG-2. And compared with CAVLC in H.264/AVC, C2DVLC shows similar coding efficiency. 展开更多
关键词 entropy coder context-based video coding VLC
原文传递
MPEG-4 SLS无损增强层的编码 被引量:1
13
作者 朱钿 《信息技术》 2007年第3期63-65,共3页
介绍了MPEG-4音频可分级无损压缩编码方案中无损增强层的编码。对无损增强层中的残差映射、比特平面编码、基于上下文的算术编码、低能量编码等技术细节进行了深入讨论和分析。最后将MPEG-4 SLS与Monkey’s Audio编码方案进行了比较,以... 介绍了MPEG-4音频可分级无损压缩编码方案中无损增强层的编码。对无损增强层中的残差映射、比特平面编码、基于上下文的算术编码、低能量编码等技术细节进行了深入讨论和分析。最后将MPEG-4 SLS与Monkey’s Audio编码方案进行了比较,以此来说明MPEG-4 SLS优异的压缩性能。 展开更多
关键词 无损音频压缩 可分级编码 比特平面编码 基于上下文算术编码 低能量编码
在线阅读 下载PDF
Trusted Routing Based on Identity-Based Threshold Signature for Opportunistic Networks 被引量:1
14
作者 陈曦 田有亮 +1 位作者 李兴华 马建峰 《China Communications》 SCIE CSCD 2011年第4期132-140,共9页
In opportunistic Networks,compromised nodes can attack social context-based routing protocols by publishing false social attributes information.To solve this problem,we propose a security scheme based on the identity-... In opportunistic Networks,compromised nodes can attack social context-based routing protocols by publishing false social attributes information.To solve this problem,we propose a security scheme based on the identity-based threshold signature which allows mobile nodes to jointly generate and distribute the secrets for social attributes in a totally self-organized way without the need of any centralized authority.New joining nodes can reconstruct their own social attribute signatures by getting enough partial signature services from encounter opportunities with the initial nodes.Mobile nodes need to testify whether the neighbors can provide valid attribute signatures for their routing advertisements in order to resist potential routing attacks.Simulation results show that:by implementing our security scheme,the network delivery probability of the social context-based routing protocol can be effectively improved when there are large numbers of compromised nodes in opportunistic networks. 展开更多
关键词 opportunistic networks social context-based routing identity-based signature threshold cryptography
在线阅读 下载PDF
High throughput VLSI architecture for H.264/AVC context-based adaptive binary arithmetic coding(CABAC) decoding 被引量:1
15
作者 Kai HUANG De MA +2 位作者 Rong-jie YAN Hai-tong GE Xiao-lang YAN 《Journal of Zhejiang University-Science C(Computers and Electronics)》 SCIE EI 2013年第6期449-463,共15页
Context-based adaptive binary arithmetic coding(CABAC) is the major entropy-coding algorithm employed in H.264/AVC.In this paper,we present a new VLSI architecture design for an H.264/AVC CABAC decoder,which optimizes... Context-based adaptive binary arithmetic coding(CABAC) is the major entropy-coding algorithm employed in H.264/AVC.In this paper,we present a new VLSI architecture design for an H.264/AVC CABAC decoder,which optimizes both decode decision and decode bypass engines for high throughput,and improves context model allocation for efficient external memory access.Based on the fact that the most possible symbol(MPS) branch is much simpler than the least possible symbol(LPS) branch,a newly organized decode decision engine consisting of two serially concatenated MPS branches and one LPS branch is proposed to achieve better parallelism at lower timing path cost.A look-ahead context index(ctxIdx) calculation mechanism is designed to provide the context model for the second MPS branch.A head-zero detector is proposed to improve the performance of the decode bypass engine according to UEGk encoding features.In addition,to lower the frequency of memory access,we reorganize the context models in external memory and use three circular buffers to cache the context models,neighboring information,and bit stream,respectively.A pre-fetching mechanism with a prediction scheme is adopted to load the corresponding content to a circular buffer to hide external memory latency.Experimental results show that our design can operate at 250 MHz with a 20.71k gate count in SMIC18 silicon technology,and that it achieves an average data decoding rate of 1.5 bins/cycle. 展开更多
关键词 H.264/AVC context-based adaptive binary arithmetic coding(CABAC) Decoder VLSI
原文传递
An adaptive pipelining scheme for H.264/AVC CABAC decoder 被引量:1
16
作者 陈杰 Ding Dandan Yu Lu 《High Technology Letters》 EI CAS 2013年第4期391-397,共7页
An adaptive pipelining scheme for H.264/AVC context-based adaptive binary arithmetic coding(CABAC) decoder for high definition(HD) applications is proposed to solve data hazard problems coming from the data dependenci... An adaptive pipelining scheme for H.264/AVC context-based adaptive binary arithmetic coding(CABAC) decoder for high definition(HD) applications is proposed to solve data hazard problems coming from the data dependencies in CABAC decoding process.An efficiency model of CABAC decoding pipeline is derived according to the analysis of a common pipeline.Based on that,several adaptive strategies are provided.The pipelining scheme with these strategies can be adaptive to different types of syntax elements(SEs) and the pipeline will not stall during decoding process when these strategies are adopted.In addition,the decoder proposed can fully support H.264/AVC high4:2:2 profile and the experimental results show that the efficiency of decoder is much higher than other architectures with one engine.Taking both performance and cost into consideration,our design makes a good tradeoff compared with other work and it is sufficient for HD real-time decoding. 展开更多
关键词 H.264/AVC context-based adaptive binary arithmetic coding (CABAC) ADAPTIVE PIPELINE data dependency data hazard
在线阅读 下载PDF
思科IOS系统的防火墙功能实现研究 被引量:1
17
作者 庞亚宾 任治洪 《甘肃科技》 2008年第9期16-20,22,共6页
随着计算机技术的应用和企业信息化程度的不断提高,网络设备开始在企业内部局域网建设中大量使用。如何防范网络中出现的种类繁多、方式不同的针对网络设备的攻击,是一个企业内部局域网络乃至整个互联网必须面对的问题。IOS(Internet Op... 随着计算机技术的应用和企业信息化程度的不断提高,网络设备开始在企业内部局域网建设中大量使用。如何防范网络中出现的种类繁多、方式不同的针对网络设备的攻击,是一个企业内部局域网络乃至整个互联网必须面对的问题。IOS(Internet Operating System)是思科公司网络设备的专用操作系统,其强大的功能和友好的界面在目前业内得到的广泛的支持和应用。文章主要讨论IOS操作系统的防火墙功能的实现及应用,涉及路由器的NAT,CBAC。 展开更多
关键词 IOS 防火墙 DOS攻击 VPN cbac NBAR
在线阅读 下载PDF
Dynamically Authorized Role-Based Access Control for Grid Applications
18
作者 YAO Hanbing HU Heping LU Zhengding LI Ruixuan 《Geo-Spatial Information Science》 2006年第3期223-228,233,共7页
Grid computing is concerned with the sharing and coordinated use of diverse resources in distributed “virtual organizations”. The heterogeneous, dynamic and multi-domain nature of these environments makes challengin... Grid computing is concerned with the sharing and coordinated use of diverse resources in distributed “virtual organizations”. The heterogeneous, dynamic and multi-domain nature of these environments makes challenging security issues that demand new technical approaches. Despite the recent advances in access control approaches applicable to Grid computing, there remain issues that impede the development of effective access control models for Grid applications. Among them there are the lack of context-based models for access control, and reliance on identity or capability-based access control schemes. An access control scheme that resolve these issues is presented, and a dynamically authorized role-based access control (D-RBAC) model extending the RBAC with context constraints is proposed. The D-RABC mechanisms dynamically grant permissions to users based on a set of contextual information collected from the system and user’s environments, while retaining the advantages of RBAC model. The implementation architecture of D-RBAC for the Grid application is also described. 展开更多
关键词 Grid security RBAC context-based access control
在线阅读 下载PDF
ODOR DISCRIMINATION BY MITRAL CELLS IN RAT OLFACTORY BULB USING MICROWIRE ARRAY RECORDING
19
作者 JUN ZHOU QI DONG +4 位作者 LIUJING ZHUANG QINGJUN LIU SHAOMIN ZHANG XIAOXIANG ZHENG PING WANG 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2012年第1期98-103,共6页
Response features of mitral cells in the olfactory bulb were examined using principal component analysis to determine whether they contain information about odorant stimuli.Using microwire electrode array to record fr... Response features of mitral cells in the olfactory bulb were examined using principal component analysis to determine whether they contain information about odorant stimuli.Using microwire electrode array to record from the olfactory bulb in freely breathing anesthetized rats,we recorded responses of different mitral cells to saturated vapor of anisole(1 M),carvone(1 M),isobutanol(1 M),citral(1 M)and isoamyl actate(1 M).The responses of single mitral cells to the same odorant varied over time.The response profiles showed similarity during certain amount of period,which indicated that the response was not only depended on odor itself but also associated with context.Furthermore,the responses of single mitral cell to different odorants were observed with difference in firing rate.In order to recognize different odorant stimuli,we apply four cells as a sensing group for classification using principal component analysis.Features of each cell’s response describing both temporal and frequency characteristics were selected.The results showed that five different single molecular odorants can be distinguished from each other.These data suggest that action potentials of mitral cells may play a role in odor coding. 展开更多
关键词 Mitral cell odor discrimination context-based response anesthetized rat
原文传递
Context-Aware Collaborative Filtering Framework for Rating Prediction Based on Novel Similarity Estimation
20
作者 Waqar Ali Salah Ud Din +3 位作者 Abdullah Aman Khan Saifullah Tumrani Xiaochen Wang Jie Shao 《Computers, Materials & Continua》 SCIE EI 2020年第5期1065-1078,共14页
Recommender systems are rapidly transforming the digital world into intelligent information hubs.The valuable context information associated with the users’prior transactions has played a vital role in determining th... Recommender systems are rapidly transforming the digital world into intelligent information hubs.The valuable context information associated with the users’prior transactions has played a vital role in determining the user preferences for items or rating prediction.It has been a hot research topic in collaborative filtering-based recommender systems for the last two decades.This paper presents a novel Context Based Rating Prediction(CBRP)model with a unique similarity scoring estimation method.The proposed algorithm computes a context score for each candidate user to construct a similarity pool for the given subject user-item pair and intuitively choose the highly influential users to forecast the item ratings.The context scoring strategy has an inherent capability to incorporate multiple conditional factors to filter down the most relevant recommendations.Compared with traditional similarity estimation methods,CBRP makes it possible for the full use of neighboring collaborators’choice on various conditions.We conduct experiments on three publicly available datasets to evaluate our proposed method with random user-item pairs and got considerable improvement in prediction accuracy over the standard evaluation measures.Also,we evaluate prediction accuracy for every user-item pair in the system and the results show that our proposed framework has outperformed existing methods. 展开更多
关键词 Recommender system context-based similarity estimation rating prediction collaborative filtering
在线阅读 下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部