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An Efficient Hybrid Algorithm for Mining Web Frequent Access Patterns 被引量:1
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作者 ZHANLi-qiang LIUDa-xin 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第5期557-560,共4页
We propose an efficient hybrid algorithm WDHP in this paper for mining frequent access patterns. WDHP adopts the techniques of DHP to optimize its performance, which is using hash table to filter candidate set and tri... We propose an efficient hybrid algorithm WDHP in this paper for mining frequent access patterns. WDHP adopts the techniques of DHP to optimize its performance, which is using hash table to filter candidate set and trimming database. Whenever the database is trimmed to a size less than a specified threshold, the algorithm puts the database into main memory by constructing a tree, and finds frequent patterns on the tree. The experiment shows that WDHP outperform algorithm DHP and main memory based algorithm WAP in execution efficiency. 展开更多
关键词 frequent access pattern AP-tree hash-table
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Framework to Model User Request Access Patterns in the World Wide Web
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作者 Richard Hurley Robert Sturgeon 《Journal of Software Engineering and Applications》 2024年第2期69-88,共20页
In this paper, we present a novel approach to model user request patterns in the World Wide Web. Instead of focusing on the user traffic for web pages, we capture the user interaction at the object level of the web pa... In this paper, we present a novel approach to model user request patterns in the World Wide Web. Instead of focusing on the user traffic for web pages, we capture the user interaction at the object level of the web pages. Our framework model consists of three sub-models: one for user file access, one for web pages, and one for storage servers. Web pages are assumed to consist of different types and sizes of objects, which are characterized using several categories: articles, media, and mosaics. The model is implemented with a discrete event simulation and then used to investigate the performance of our system over a variety of parameters in our model. Our performance measure of choice is mean response time and by varying the composition of web pages through our categories, we find that our framework model is able to capture a wide range of conditions that serve as a basis for generating a variety of user request patterns. In addition, we are able to establish a set of parameters that can be used as base cases. One of the goals of this research is for the framework model to be general enough that the parameters can be varied such that it can serve as input for investigating other distributed applications that require the generation of user request access patterns. 展开更多
关键词 Performance Modelling World Wide Web SIMULATION User Request access patterns FRAMEWORK
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Efficient verifiable searchable encryption with search and access pattern privacy 被引量:1
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作者 Axin Wu Dengguo Feng +2 位作者 Min Zhang Jialin Chi Yinghui Zhang 《Security and Safety》 2025年第1期28-48,共21页
Searchable encryption(SE)enables data users to securely search encrypted data stored in untrusted cloud servers.However,most SE schemes allow for leakages of access and search patterns to maximize efficiency and funct... Searchable encryption(SE)enables data users to securely search encrypted data stored in untrusted cloud servers.However,most SE schemes allow for leakages of access and search patterns to maximize efficiency and functionality.Recent attacks have shown that adversaries can recover query keywords with prior knowledge of the database by exploiting these leakages.Unfortunately,the existing schemes that protect access and search patterns result in frequent communications and high computational costs.Furthermore,complex calculation processes also raise challenges for verifying search results.To address these concerns,we first design an efficient conjunctive SE scheme with search and access pattern privacy using private set intersection.In the proposed scheme,we utilize random numbers to obfuscate the values of polynomials and randomly divide the results into two parts,which simplifies the search process,improves search efficiency,and eliminates the need for time-consuming ciphertext multiplication operations.We also extend this scheme to support search result verifiability.Specifically,by embedding a random number as the root of the return polynomial,we achieve verifiability of search results.Furthermore,we prove the security of both schemes employing the simulation-based method.Finally,we implement the schemes in a real database and thorough performance analyses demonstrate their efficiency. 展开更多
关键词 Searchable encryption Private set intersection Search and access pattern Verifiability Conjunctive search
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Uplink Grant-Free Pattern Division Multiple Access (GF-PDMA) for 5G Radio Access 被引量:12
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作者 Wanwei Tang Shaoli Kang +1 位作者 Bin Ren Xinwei Yue 《China Communications》 SCIE CSCD 2018年第4期153-163,共11页
Massive machine type communication(m MTC) is one of the key application scenarios for the fifth generation mobile communication(5 G). Grant-free(GF) transmission can reduce the high signaling overhead in m MTC. Non-or... Massive machine type communication(m MTC) is one of the key application scenarios for the fifth generation mobile communication(5 G). Grant-free(GF) transmission can reduce the high signaling overhead in m MTC. Non-orthogonal multiple access(NMA) can support more users for m MTC than orthogonal frequency division multiple access(OFDMA). Applying GF transmission in NMA system becomes an active topic recently. The in-depth study on applying GF transmission in pattern division multiple access(PDMA), a competitive candidate scheme of NMA, is investigated in this paper. The definition, latency and allocation of resource and transmission mechanism for GF-PDMA are discussed in detail. The link-level and system-level evaluations are provided to verify the analysis. The analysis and simulation results demonstrate that the proposed GF-PDMA has lower latency than grant based PDMA(GB-PDMA), possesses strong scalability to confront collision and provides almost 2.15 times gain over GF-OFDMA in terms of supporting the number of active users in the system. 展开更多
关键词 pattern division multiple access(PDMA) grant-free UPLINK massive machinetype communication (mMTC) 5G
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Pattern imprinting in deep sub-micron static random access memories induced by total dose irradiation
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作者 郑齐文 余学峰 +4 位作者 崔江维 郭旗 任迪远 丛忠超 周航 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第10期362-368,共7页
Pattem imprinting in deep sub-micron static random access memories (SRAMs) during total dose irradiation is inves- tigated in detail. As the dose accumulates, the data pattern of memory cells loading during irradiat... Pattem imprinting in deep sub-micron static random access memories (SRAMs) during total dose irradiation is inves- tigated in detail. As the dose accumulates, the data pattern of memory cells loading during irradiation is gradually imprinted on their background data pattern. We build a relationship between the memory cell's static noise margin (SNM) and the background data, and study the influence of irradiation on the probability density function of ASNM, which is the difference between two data sides' SNMs, to discuss the reason for pattern imprinting. Finally, we demonstrate that, for micron and deep sub-micron devices, the mechanism of pattern imprinting is the bias-dependent threshold shift of the transistor, but for a deep sub-micron device the shift results from charge trapping in the shallow trench isolation (STI) oxide rather than from the gate oxide of the micron-device. 展开更多
关键词 total dose irradiation static random access memory pattern imprinting deep sub-micron
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X-Raying Rainfall Pattern and Variability in Northeastern Nigeria: Impacts on Access to Water Supply
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作者 H. T. Ishaku M. Rafee Majid 《Journal of Water Resource and Protection》 2010年第11期952-959,共8页
This paper is premised on the hypothesis that the amount of rainfall in Nigeria decreases with increasing distance from the coastal areas to the north semi arid lands. This belief widely held in some circles does not ... This paper is premised on the hypothesis that the amount of rainfall in Nigeria decreases with increasing distance from the coastal areas to the north semi arid lands. This belief widely held in some circles does not really follow this pattern due to other climatic factors. This paper examined rainfall pattern and its variability in northeastern Nigeria and its impacts on access to water supply. Data on the mean monthly rainfall over a period of 33 years (1970-2002) were collected from the Nigeria Meteorological Agency (NIMET) in Abuja, Nigeria. The result of the analysis indicates that the mean annual rainfall in the study area is not dependent on distance but some other climatic factors such as relief, solar radiation, temperature, winds, and nature of soil among others. Thus, the amount of rainfall received in Taraba and Borno states which are located in the southern most and extreme end of the study area respectively were higher than that of Gombe state which lies in between them. 展开更多
关键词 RAINFALL pattern VARIABILITY Impact access to Water NORTHEASTERN NIGERIA
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总分式任务驱动教学法在Access数据库教学中的应用 被引量:1
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作者 万李 《湖南科技学院学报》 2012年第12期72-74,共3页
通过"access数据库应用技术"课程的教学实践,对教学方法和教学内容进行了深入研究,指出了教学中存在的问题,结合学生的认知规律,提出总分式任务驱动的教学方法,采用这种方法能达到增强学生学习主观能动性、提高教学效果的目的。
关键词 access数据库 总分式 任务驱动教学
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Optimizing Memory Access Efficiency in CUDA Kernel via Data Layout Technique
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作者 Neda Seifi Abdullah Al-Mamun 《Journal of Computer and Communications》 2024年第5期124-139,共16页
Over the past decade, Graphics Processing Units (GPUs) have revolutionized high-performance computing, playing pivotal roles in advancing fields like IoT, autonomous vehicles, and exascale computing. Despite these adv... Over the past decade, Graphics Processing Units (GPUs) have revolutionized high-performance computing, playing pivotal roles in advancing fields like IoT, autonomous vehicles, and exascale computing. Despite these advancements, efficiently programming GPUs remains a daunting challenge, often relying on trial-and-error optimization methods. This paper introduces an optimization technique for CUDA programs through a novel Data Layout strategy, aimed at restructuring memory data arrangement to significantly enhance data access locality. Focusing on the dynamic programming algorithm for chained matrix multiplication—a critical operation across various domains including artificial intelligence (AI), high-performance computing (HPC), and the Internet of Things (IoT)—this technique facilitates more localized access. We specifically illustrate the importance of efficient matrix multiplication in these areas, underscoring the technique’s broader applicability and its potential to address some of the most pressing computational challenges in GPU-accelerated applications. Our findings reveal a remarkable reduction in memory consumption and a substantial 50% decrease in execution time for CUDA programs utilizing this technique, thereby setting a new benchmark for optimization in GPU computing. 展开更多
关键词 Data Layout Optimization CUDA Performance Optimization GPU Memory Optimization Dynamic Programming Matrix Multiplication Memory access pattern Optimization in CUDA
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Pattern Matrix Design of PDMA for 5G UL Applications 被引量:4
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作者 Bin Ren Yingmin Wang +2 位作者 Xiaoming Dai Kai Niu Wanwei Tang 《China Communications》 SCIE CSCD 2016年第S2期159-173,共15页
Pattern division multiple access(PDMA),which is a novel non-orthogonal multiple access(NOMA),has been proposed to address the challenges of massive connectivity and higher spectral efficiency for fifth generation(5G) ... Pattern division multiple access(PDMA),which is a novel non-orthogonal multiple access(NOMA),has been proposed to address the challenges of massive connectivity and higher spectral efficiency for fifth generation(5G) mobile network.The performance of PDMA mainly depends on the design of PDMA pattern matrix.In this paper,pattern matrix design of PDMA for 5G uplink(UL) applications in massive machine type communication(mMTC) and enhanced mobile broadband(eMBB) deployment scenarios are studied.The design criteria and examples for application in UL mMTC and UL eMBB are investigated.The performance of the PDMA pattern matrix is analyzed with the discrete constellation constrained capacity(CC-Capacity),and verified by Monte Carlo simulation.The simulation results show that the preferred PDMA pattern matrix can achieve good performance with different overloading factors(OF). 展开更多
关键词 5G non-orthogonal multiple access PDMA pattern matrix CC-Capacity SIC
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Transnational Economic Connection Analysis Based on Railway Class Accessibility Between China and Russia 被引量:3
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作者 CHU Nanchen ZHANG Pingyu LI He 《Chinese Geographical Science》 SCIE CSCD 2019年第5期872-886,共15页
Under the background of ‘the Belt and Road’ initiative, the economic cooperation has great potential between China and Russia. The railway accessibility has an important influence on the economic connections of citi... Under the background of ‘the Belt and Road’ initiative, the economic cooperation has great potential between China and Russia. The railway accessibility has an important influence on the economic connections of cities along the railway line. This paper studied the Sino-Russian transnational economic connection based on the railway class accessibility along Trans-Siberian railway(the transnational China railway branch line). The results are as following. First, the railway accessibility of the Chinese nodes is stronger than that of the Russian nodes, which in general displays a tendency of space attenuation from China to the Sino-Russian border, then to Russia. Spatially, the railway accessibility within the study area shows a ‘High East, Low West’ and ‘High South, Low North’ spatial pattern. The railway accessibility of the nodes, which are located at the beginning and end of the railway line, is weaker than those nodes located in the middle of the line. Second, the railway accessibility and external economic connection intensity summation of the nodes show a positive relationship along the railway line. The economic connection intensity summation of different nodes presents obvious regional differentiation. Finally, as economic connection network has evolved, the small world effect of Sino-Russian railway economic connection network becomes strong. 展开更多
关键词 RAILWAY class accessIBILITY ECONOMIC CONNECTION intensity spatial pattern China Russia
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利用Access开发中小型数据库管理系统
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作者 张婷 《唐山师专学报》 2000年第5期69-71,共3页
从实例的角度探讨了用关系型数据库管理软件Access设计开发中、小型数据库管理系统的方法。主要介绍了利用Access开发的“培训与考试管理系统”的组成、基本原理和基本功能。
关键词 关系型数据库 access 功能模块 数据库管理系统
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我国校园足球“满天星”训练营空间格局特征与可达性研究 被引量:1
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作者 胡用岗 杨成伟 《吉林体育学院学报》 2025年第3期75-84,共10页
“满天星”训练营作为新时代校园足球全面深入开展的标志性工程,是实现精英足球后备人才高质量培养的重要平台。运用空间分析法对“满天星”训练营空间格局特征及可达性进行综合分析,并结合校园足球特色学校空间布局进行比较研究。结果... “满天星”训练营作为新时代校园足球全面深入开展的标志性工程,是实现精英足球后备人才高质量培养的重要平台。运用空间分析法对“满天星”训练营空间格局特征及可达性进行综合分析,并结合校园足球特色学校空间布局进行比较研究。结果表明:“满天星”训练营呈现“东部多中西部少”的空间分布格局,具有集聚分布特征,与特色学校分布呈正相关关系。空间尺度经历了由单核心区向多核心区发展的演变历程,逐步形成了3个高密度区和7个次高密度区,并与特色学校在空间密度上存在适配和错配两种分布形态。其空间重心分布主趋势为“东北-西南”方向,同特色学校的分布重心相差较大且两者重心朝“相互偏离”的趋势发展。整体可达性较差,平均可达时间为183min,1.5h以内的高可达性“满天星”训练营仅占14.49%,且省域可达性的空间差异显著。最后,从设立空间配置标准、优化空间布局、改善可达性水平、提高科学化管理水平、加强考核与监督等方面提出相应的对策建议,以期为校园足球“满天星”训练营空间优化布局和健康发展提供科学参考。 展开更多
关键词 校园足球 “满天星”训练营 空间格局 可达性 ARCGIS
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一种具有多级安全目标的动态对称可搜索加密方案
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作者 李功丽 李露 +1 位作者 黄昱晨 陈晓迪 《计算机应用研究》 北大核心 2025年第7期2168-2175,共8页
可搜索加密是将数据文件加密后存储到云端,然后对密文进行检索的一种技术。动态可搜索加密允许对云端的文件进行动态更新,然而现有动态可搜索加密方案都着重解决前向和后向安全问题且大多仅支持单用户搜索,无法同时保护搜索模式和访问... 可搜索加密是将数据文件加密后存储到云端,然后对密文进行检索的一种技术。动态可搜索加密允许对云端的文件进行动态更新,然而现有动态可搜索加密方案都着重解决前向和后向安全问题且大多仅支持单用户搜索,无法同时保护搜索模式和访问模式。针对上述问题,基于不经意键值对存储技术,设计了一种满足前向安全、隐藏搜索模式和访问模式、具有三级安全目标的动态对称可搜索加密方案TS-MDSSE。并在此基础上,进一步在更新算法中利用随机值替换技术,满足了后向安全,实现了具有四级安全目标的FS-MDSSE方案。安全分析与实验表明,所提方案不仅满足多等级安全目标,而且支持多用户查询,完成一次搜索仅需0.022 ms。 展开更多
关键词 动态对称可搜索加密 多用户 搜索模式隐藏 访问模式隐藏 前后向安全 多级安全目标
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Weed-Suppressing Effect and Mechanism of Allelopathic Rice Accessions
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作者 HUFei KONGChui-hua +2 位作者 XUXiao-hua ZHANGChao-xian CHENXiong-hui 《Agricultural Sciences in China》 CAS CSCD 2004年第8期590-597,共8页
Two allelopathic rice accessions, PI312777 and Allelopathy1, significantly suppressedthe growth of associated weeds in the field. Moreover, their weed-suppressing effectswere correlated with the cultivation patterns. ... Two allelopathic rice accessions, PI312777 and Allelopathy1, significantly suppressedthe growth of associated weeds in the field. Moreover, their weed-suppressing effectswere correlated with the cultivation patterns. The weed-suppressing effects of throwingand transplanting were more effective than that of direct seeding. Furthermore, theamounts of allelochemicals (resorcinols, flavones and hydroxamic acids) produced andreleased from two allelopathic rice accessions were much higher than that from a non-allelopathic rice variety Hua-Jing-Xian1, and reached the maximum concentration at the6th leaf stage. Differences in the weed-suppressing effects of rice accessions appear toresult from the accessions producing and releasing different amounts of allelochemicalsin the field. Further research confirmed that in PI312777 plants, allelochemicals weresynthesized by the above-ground parts, and then secreted through the root tissues. Roottissues of PI312777 plants never produced the allelochemicals. Root exudates fromPI312777 could significantly inhibit the growth of E. crus-galli surrounding rice plantsin water culture. However, when activated carbon was added to the culture solution, whichcould absorb allelochemicals from root exudates, the growth of E. crus-galli was nolonger significantly inhibited. Weed-suppressing effects of rice accessions depended onallelopathy, cultivation patterns and other factors in rice fields, while allelopathywas one of important factors. Interestingly, the amounts of allelochemicals produced andreleased from allelopathic rice plants may be induced by the presence of E. crus-galli.This suggests that there is a possible chemical recognition between rice and E. crus-galli. 展开更多
关键词 Rice (Oryza sativa L.) Allelopathic accession Allelochemical Weed management Root exudates Cultivated patterns
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隐藏共现模式的可搜索对称加密方案
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作者 何丽梅 《软件导刊》 2025年第4期123-129,共7页
可搜索对称加密(SSE)是一种在大数据和云计算环境下解决数据安全与隐私保护问题的关键技术,其允许用户在不解密的情况下对加密数据进行安全查询。大多数现有的SSE方案为保证方案的高效性会泄露访问模式,访问模式泄露了查询令牌与被匹配... 可搜索对称加密(SSE)是一种在大数据和云计算环境下解决数据安全与隐私保护问题的关键技术,其允许用户在不解密的情况下对加密数据进行安全查询。大多数现有的SSE方案为保证方案的高效性会泄露访问模式,访问模式泄露了查询令牌与被匹配文档之间的关系,进而会揭露共现模式。共现模式为每一对关键字在一个文档集中出现概率所组成的概率矩阵,其是IKK攻击这一类推理攻击的基础。因此,共现模式的泄漏已经严重威胁到加密数据安全。针对这一问题,提出一种隐藏共现模式的文档填充算法,并基于该算法设计了可有效隐藏共现模式的可搜索对称加密方案。安全性分析表明,该方案是安全且有效的,同时基于真实数据集进行的实验结果也表明该方案能够有效防止共现模式泄漏。 展开更多
关键词 可搜索对称加密 访问模式 共现模式 IKK攻击 推理攻击
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A New DAO Pattern with Dynamic Extensibility
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作者 Cheng Fang Ping Zeng 《Journal of Electronic Science and Technology of China》 2007年第3期212-214,共3页
Currently existing data access object (DAO) patterns have several limitations. First, the interface of the patterns and business objects is tightly-coupled, which affects seriously the dynamic extensibility of softw... Currently existing data access object (DAO) patterns have several limitations. First, the interface of the patterns and business objects is tightly-coupled, which affects seriously the dynamic extensibility of software systems. Second, the patterns have duplicated implementation codes, which add to difficulties of system maintenance. To solve these problems, a new DAO pattern with stronger independency and dynamic extensibility is proposed in this paper. An example is given to illustrate the using process of the new DAO pattern. The greatest advantages of the new DAO pattern are as follows. If any business object is needed to add to the system, we do not have to modify any codes of the class DAO Factory. All we need to do is to modify the mapping file. Furthermore, because we have only one DAO implementation class to accomplish all the data access to business objects, if some SQL statements are needed to be modified, all we need to do is to modify the DAO implementation class but not need to modify any business objects. 展开更多
关键词 Data access object (DAO) data binding meta model pattern.
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An Improved Real-Time Face Recognition System at Low Resolution Based on Local Binary Pattern Histogram Algorithm and CLAHE 被引量:2
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作者 Kamal Chandra Paul Semih Aslan 《Optics and Photonics Journal》 2021年第4期63-78,共16页
This research presents an improved real-time face recognition system at a low<span><span><span style="font-family:" color:red;"=""> </span></span></span><... This research presents an improved real-time face recognition system at a low<span><span><span style="font-family:" color:red;"=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">resolution of 15 pixels with pose and emotion and resolution variations. We have designed our datasets named LRD200 and LRD100, which have been used for training and classification. The face detection part uses the Viola-Jones algorithm, and the face recognition part receives the face image from the face detection part to process it using the Local Binary Pattern Histogram (LBPH) algorithm with preprocessing using contrast limited adaptive histogram equalization (CLAHE) and face alignment. The face database in this system can be updated via our custom-built standalone android app and automatic restarting of the training and recognition process with an updated database. Using our proposed algorithm, a real-time face recognition accuracy of 78.40% at 15</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px and 98.05% at 45</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px have been achieved using the LRD200 database containing 200 images per person. With 100 images per person in the database (LRD100) the achieved accuracies are 60.60% at 15</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px and 95% at 45</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px respectively. A facial deflection of about 30</span></span></span><span><span><span><span><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span></span><span> on either side from the front face showed an average face recognition precision of 72.25%-81.85%. This face recognition system can be employed for law enforcement purposes, where the surveillance camera captures a low-resolution image because of the distance of a person from the camera. It can also be used as a surveillance system in airports, bus stations, etc., to reduce the risk of possible criminal threats.</span></span></span></span> 展开更多
关键词 Face Detection Face Recognition Low Resolution Feature Extraction Security System access Control System Viola-Jones Algorithm LBPH Local Binary pattern Histogram
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我国国土空间交通可达性测度与时空格局研究 被引量:2
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作者 马王钰青 《铁道运输与经济》 北大核心 2025年第4期78-87,共10页
交通是国土空间规划的关键骨架,研究国土空间交通可达性有助于优化国土空间布局、提升交通运输质量。以我国335个城市为研究对象,从“时空收敛”和“网络关联”维度,构建基于公路、高速铁路和民航的可达性指标,研究中国综合交通和不同... 交通是国土空间规划的关键骨架,研究国土空间交通可达性有助于优化国土空间布局、提升交通运输质量。以我国335个城市为研究对象,从“时空收敛”和“网络关联”维度,构建基于公路、高速铁路和民航的可达性指标,研究中国综合交通和不同交通可达性空间格局及时间演变特征。结果表明,综合交通可达性水平随国土空间交通运输体系的完善逐年提高,以胡焕庸线为分界线,东南部较西北部城市具有更高的可达性和更快的增长速度,呈东中西递减分布,直辖市、省会城市与其连接起的通道具有较高可达性。公路可达性呈现“核心-外围”圈层结构;高速铁路可达性随年份增加沿铁路主干线向外延伸,整体发展迅速;民航可达性呈现出不规则分散结构。研究结果以期为国土空间交通规划提供科学合理支撑。 展开更多
关键词 国土空间 城市 可达性 综合交通 时空格局
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基于访存图案变形的CGRA存储划分优化
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作者 潘德财 牟迪 +1 位作者 尚家兴 刘大江 《计算机研究与发展》 北大核心 2025年第4期1003-1016,共14页
由于兼具高灵活性和高能效的特征,粗粒度可重构阵列(coarse-grained reconfigurable array,CGRA)是一种具有潜力的领域定制加速器架构.为了利用多bank存储器的访问并行性,通常会在CGRA中引入存储器划分.然而,在CGRA上进行存储划分工作... 由于兼具高灵活性和高能效的特征,粗粒度可重构阵列(coarse-grained reconfigurable array,CGRA)是一种具有潜力的领域定制加速器架构.为了利用多bank存储器的访问并行性,通常会在CGRA中引入存储器划分.然而,在CGRA上进行存储划分工作要么以昂贵的寻址开销为代价实现最佳分区解决方案,要么以更多的存储bank消耗为代价来减少面积和功耗开销.为此,提出了一种通过访存图案变形来实现面向CGRA的存储划分方法.通过对包含多维数组的应用进行存储划分和算子调度协同优化,形成了存储划分友好的访存图案,从而可以用全“1”超平面对其进行存储划分,进而优化了划分结果并减少了访存地址计算开销.基于全“1”超平面的划分策略,还提出了一种可精简地址生成单元的高能效CGRA架构.实验结果表明,与最先进的方法相比,该方法可以实现1.25倍的能效提升. 展开更多
关键词 粗粒度可重构阵列 存储划分 软硬件联合设计 算子调度 访存图案
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基于多出行模式的新乡市主城区公园绿地可达性分析
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作者 赵梦蕾 毛达 姚正阳 《生态科学》 北大核心 2025年第5期47-55,共9页
城市公园绿地可达性能够反映城市公园绿地资源的供需服务水平,促进城市品质提升。综合运用GIS和两步移动搜索法分析多出行模式下河南新乡市主城区城市公园绿地的可达性,并引入洛伦兹曲线和基尼系数分析其公平性。结果表明:(1)不同出行... 城市公园绿地可达性能够反映城市公园绿地资源的供需服务水平,促进城市品质提升。综合运用GIS和两步移动搜索法分析多出行模式下河南新乡市主城区城市公园绿地的可达性,并引入洛伦兹曲线和基尼系数分析其公平性。结果表明:(1)不同出行模式下城市公园绿地可达性数值差异较大。(2)现状公园绿地资源分布较为不公平,步行模式下资源分布悬殊。(3)主城区各居住单元的城市公园绿地可达性呈现出西低东高的空间格局。可通过改善西部片区交通条件、合理利用城市闲置空间、提升公园绿地品质等方式,优化城市公园绿地布局,提升社会公平性。 展开更多
关键词 公园绿地 可达性 社会公平 空间格局 河南新乡
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