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高考命题中的量化区分功能设计——难度常模在命题中的应用 被引量:2
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作者 臧铁军 赵海燕 《中国考试》 2010年第12期3-10,共8页
难度常模的构建导致命题理念的转变及控制技术方面的突破,同时使得量化区分功能设计成为可能。量化区分功能设计主要借助难度分布和区分结构的调控来实现。试卷的区分结构更多针对被试群体进行分层性区分,难度分布则影响考试结果的分... 难度常模的构建导致命题理念的转变及控制技术方面的突破,同时使得量化区分功能设计成为可能。量化区分功能设计主要借助难度分布和区分结构的调控来实现。试卷的区分结构更多针对被试群体进行分层性区分,难度分布则影响考试结果的分数分布形态。在设计试卷时不能只关注平均难度和平均区分度,而应使试卷的难度分布和区分结构与考生的能力层次相匹配、与考试目的相适应。难度分布与区分结构对于不同类型考试的意义不同,选拔性考试应更多考虑区分结构,水平性考试则要更多关注难度分布。 展开更多
关键词 难度常模 量化区分功能 试卷难度分布 试卷区分结构 命题蓝图
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3D密码的7轮子空间迹区分器
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作者 杨阳 刘文豪 曾光 《电子与信息学报》 EI CSCD 北大核心 2023年第2期617-625,共9页
子空间迹攻击是一种新型分组密码分析方法,该文对使用了类AES密码新结构的3D密码子空间性质进行研究。首先利用3D密码的3轮明确子空间迹,结合子空间的交集性质,首次构造出3D密码的7轮子空间迹不可能差分区分器,数据复杂度为2193.1个选... 子空间迹攻击是一种新型分组密码分析方法,该文对使用了类AES密码新结构的3D密码子空间性质进行研究。首先利用3D密码的3轮明确子空间迹,结合子空间的交集性质,首次构造出3D密码的7轮子空间迹不可能差分区分器,数据复杂度为2193.1个选择明文,时间复杂度为2202.3次查表操作,成功率为60.6%;“n倍”性质指子空间的全部明文对经过一轮加密,差分属于同一子空间的密文对个数为n的倍数。利用该性质,构造了3D密码的7轮结构区分器,数据复杂度为2128个选择明文,时间复杂度为2129.6次查表操作,存储复杂度为2128Byte,成功率大于99.99%。 展开更多
关键词 子空间迹 不可能差分 结构区分 3D密码
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IP QoS中两种体系结构的分析与比较
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作者 梁伟 郑伟 《教学与科技》 2004年第3期11-17,共7页
本文系统分析了IP QoS中IntServ和DiffServ的组成和原理,并对这两种结构进行了详细的比较,指出了其各自的优缺点和适用范围。进一步介绍了一种二者结合的混合模型。
关键词 计算机网络 服务质量 综合服务体系结构 区分服务体系结构 资源预留协议
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一种新的Ad hoc网络中的QoS体系结构
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作者 胡连芳 李云 +2 位作者 刘占军 陈前斌 隆克平 《计算机应用研究》 CSCD 北大核心 2006年第8期80-82,共3页
由于MAC机制本身具有带宽分配的能力,Ad hoc网中的区分服务不能实现理想的业务区分。针对该问题提出了一种新的Ad hoc网络的QoS体系结构D iff-EDCF,它通过把区分服务体系结构和IEEE 802.11eMAC层的EDCF机制相结合的方法来解决上述问题,... 由于MAC机制本身具有带宽分配的能力,Ad hoc网中的区分服务不能实现理想的业务区分。针对该问题提出了一种新的Ad hoc网络的QoS体系结构D iff-EDCF,它通过把区分服务体系结构和IEEE 802.11eMAC层的EDCF机制相结合的方法来解决上述问题,并且进行了仿真验证。仿真结果表明,把此体系结构应用于Adhoc网络后,业务在任何情况下均能被区分,在特定拓扑下通过调节MAC层参数可以达到理想的吞吐量的比值。 展开更多
关键词 AD HOC网络 区分服务体系结构 IEEE 802 11e EDCF机制
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浅析have sth done,have sb do sth与have sb/sth doing三种结构
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作者 吕富保 《中学英语园地(八九年级适用)》 2005年第12期15-16,共2页
关键词 宾语补足语 初中英语 过去分词 结构区分 现在分词 正在进行 动作 浅析 动词不定式 使役动词
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意外地点任务中不同测试问题及意图理解与执行功能的关系 被引量:16
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作者 廖渝 吴睿明 +5 位作者 Philip David Zelazo 李红 张婷 张莉 高山 李小晶 《心理学报》 CSSCI CSCD 北大核心 2006年第2期207-215,共9页
旨在讨论意外地点任务中“知否问题”与“预测问题”可能存在的差异及两者与执行功能任务的关系,并初步探讨意图理解与执行功能问的关系。用意外地点任务、膝跳反射任务和两个执行功能的任务(DCCS和手部游戏)对59名3~5岁的儿童施测... 旨在讨论意外地点任务中“知否问题”与“预测问题”可能存在的差异及两者与执行功能任务的关系,并初步探讨意图理解与执行功能问的关系。用意外地点任务、膝跳反射任务和两个执行功能的任务(DCCS和手部游戏)对59名3~5岁的儿童施测。结果显示:(1)儿童在意外地点任务的“知否问题”上的表现显著好于“预测问题”,儿童对“知否问题”和“预测问题”的回答可能反映了心理理论发展的不同阶段。(2)膝跳反射任务,DCCS任务与“知否问题”三者问有显著的相关,且其高相关在排除年龄及语言能力的影响后仍保持显著。“双表征区分结构”可能是三者间共同的成分。 展开更多
关键词 心理理论 执行功能 意图 双表征区分结构
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高等教育自学考试复本试卷平行性的试后初步评价 被引量:2
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作者 赵海燕 王桥影 《中国考试》 2011年第5期13-19,共7页
与高等教育自学考试复本试卷平行性有关的因素主要有四类:试卷结构的、题目内容的、题目功能的和结果分数的。复本试卷内容上的平行是试卷平行性的前提与基础,对内容平行的判定主要通过专家判断题目的取样代表性来实现。对复本试卷总体... 与高等教育自学考试复本试卷平行性有关的因素主要有四类:试卷结构的、题目内容的、题目功能的和结果分数的。复本试卷内容上的平行是试卷平行性的前提与基础,对内容平行的判定主要通过专家判断题目的取样代表性来实现。对复本试卷总体分数的比较主要借助方差齐性检验和平均数差异显著性检验,还可通过雷达图比较同一专业下多个学科的水平变化。题目功能的平行主要借助难度分布和区分结构的比较,多个难度级别分值相差较大表明复本试卷未能满足平行性要求,不同区分功能类型的题目分值较为一致则表明试卷实现了区分功能的平行。 展开更多
关键词 高等教育自学考试 复本试卷 平行性 内容效度 方差齐性检验 检验 难度分布 区分功能类型 区分结构
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Division of Farmland Use in East China at County level Based on Landscape Structure and Output Function——a Case of Pingdu City, Shandong Province
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作者 吴金凤 姜晓燕 +2 位作者 王秀红 郭跃升 李民 《Agricultural Science & Technology》 CAS 2015年第7期1508-1513,共6页
[Objective] The aim was to research the relationships among different e- valuation farmland units and conduct division-of farmland use in order to provide scientific references for protection and rational use of farml... [Objective] The aim was to research the relationships among different e- valuation farmland units and conduct division-of farmland use in order to provide scientific references for protection and rational use of farmland at county level. [Method] Using Pingdu City as a case, the research selected land use indices such as farmland use structure, output, geographical location, eta/., and then performed a cluster analysis for farmland use division. [Result] Farmlands in Pingdu can be classified into 4 groups. In groups 1 and 2, it is necessary to strengthen farmland protection, especially for highly-quality farmlands, to guarantee the quantity and quality of local crops. In groups 1 and 3, it is necessary to improve concentration degree and use rate of construction lands and control farmland pollution possibly caused by constructions. In group 4, priority should be given to maintaining diversity of land use patterns, and avoiding aimless farming expansion. [Conclusion] During urbanization process in eastern coastal agricultural regions, it is of importance to prevent fertile farmlands being occupied by construction lands to enhance use rate of construction lands. Furthermore, agricultural non-point pollution should be detected constantly in intensively used farmlands, especially in vegetable fields. Additionally, land use diversity should be well protected by avoiding farmland expansion and im- proving farmland environment. 展开更多
关键词 Division of farmland use Landscape structure OUTPUT Spatial location
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一个新的拓扑指数用于饱和烷烃的QSPR研究
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作者 徐颂华 任碧野 +1 位作者 赵鹤平 彭晓春 《吉首大学学报》 1998年第1期20-24,共5页
在分子图的邻接矩阵和距离矩阵的基础上提出了一个新的拓扑指数Sv,该拓扑指数与饱和烷烃的正常沸点具有较好的性质相关性,且易于计算,并且对饱和烷烃有较好的结构区分能力。
关键词 图论 拓扑指数 饱和烷烃 QSPR 结构-性质/活性相关性 结构区分能力
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字理,让识字变轻松
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作者 李娜玲 《文理导航》 2020年第21期48-49,共2页
识字是阅读和写作的基础,是语文教学的一项重要任务,其重要性不言而喻。然而,有一部分汉字极易写错,对此,教师可以适度地运用字理知识,引导学生识记部件、区分结构、辨别同音字,在理解中巧妙地识记,达到轻松识字的目的。
关键词 字理识字 识记部件 区分结构 辨别同音字
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辽宁联通城域网QoS研究及部署
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作者 李木子 《电信科学》 北大核心 2011年第S1期222-226,共5页
为保证IP城域网多业务承载服务质量,根据语音、视频和数据等不同业务的特性,实现QoS差异化保障,出现网络拥塞等异常情况时,可以将网络资源优先配置给高价值业务。辽宁联通从城域网网络架构、业务开展情况、等级设计、业务带宽分配以及... 为保证IP城域网多业务承载服务质量,根据语音、视频和数据等不同业务的特性,实现QoS差异化保障,出现网络拥塞等异常情况时,可以将网络资源优先配置给高价值业务。辽宁联通从城域网网络架构、业务开展情况、等级设计、业务带宽分配以及不同设备对QoS的支持能力等方面展开了深入的分析研究,并在全省城域网部署了基于DiffServ的IP QoS技术应用。 展开更多
关键词 QOS 区分服务体系结构 队列调度 等级标记
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Structural analysis of information digitization on process of Dujiangyan area in Sichuan earthquake(Ms 5.0) 被引量:2
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作者 Chen Gangyi Lu Yajun +2 位作者 Si Si Xu Shuisen Huang Wen 《Engineering Sciences》 EI 2012年第1期48-55,共8页
This paper attempts to analyze geothermy revealed by the sounding data at 8 h and 20 h every day from China Meteorological Administration and the data counted per minute such as the wellhead temperature,the electromag... This paper attempts to analyze geothermy revealed by the sounding data at 8 h and 20 h every day from China Meteorological Administration and the data counted per minute such as the wellhead temperature,the electromagnetic disturbance,the ground tilt and so of water level instrument in Sanxing of Chengdu with the method of information digitization.The result shows the recognizable differentiation of the change process before and after the earthquake,provides an analytic method for the improvement of earthquake prediction or prevention,and shows the feasible further research and the wide application prospect. 展开更多
关键词 IRREGULARITY changing information DIGITIZATION earthquake forecast
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生产责任制的理论依据 被引量:1
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作者 沈元翰 《学习与探索》 1982年第1期96-97,共2页
生产责任制的出现与存在,是同生产发展的一定历史阶段相联系的。马克思说:“不论生产的社会形式如何,劳动者和生产资料始终是生产的要素,但是,二者在彼此分离的情况下,只在可能性上是生产因素,凡要进行生产,就必须使他们结合起来,实行... 生产责任制的出现与存在,是同生产发展的一定历史阶段相联系的。马克思说:“不论生产的社会形式如何,劳动者和生产资料始终是生产的要素,但是,二者在彼此分离的情况下,只在可能性上是生产因素,凡要进行生产,就必须使他们结合起来,实行这种结合的特殊方式和方法,使社会结构区分为各个不同的经济时期。”(《资本论》第2卷,第44页)在各个不同的社会形态(经济时期)中,劳动者与生产资料实行结合的方式和方法各自不同。在资本主义社会中,“ 展开更多
关键词 生产责任制 生产资料 劳动者 历史阶段 生产发展 资本主义社会 社会形态 马克思 相分离 结构区分
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Application of Two-Order Difference to Gap Statistic
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作者 岳士弘 王秀秀 魏苗苗 《Transactions of Tianjin University》 EI CAS 2008年第3期217-221,共5页
Gap statistic is a well-known index of clustering validity, but its realization is difficult to be comprehended and accurately determined. A direct method is presented to improve the performance of the Gap statistic, ... Gap statistic is a well-known index of clustering validity, but its realization is difficult to be comprehended and accurately determined. A direct method is presented to improve the performance of the Gap statistic, which applies the two-order difference of within-cluster dispersion to replace the constructed null reference distribution in the Gap statistic. Hence, the realization of the Gap statistic becomes easy and is reformulated, and its uncertainty in applications is reduced. Also, the limitation of the Gap statistic is analyzed by two typical examples, that is, the Gap statistic is difficult to be applied to the dataset that contains strong-overlap or uneven-density clusters. Experiments verify the usefulness of the proposed method. 展开更多
关键词 clustering validity Gap statistic data structure
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The Evaluation of the Sound Insulation of Partition in Expanded Frequency Range 被引量:2
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作者 Nataliya Samoylenko Vitaliy Didkovskiy 《Journal of Physical Science and Application》 2013年第4期249-255,共7页
This paper reports on an evaluation of airborne sound insulation in a wider frequency range then is used in classical measurements. For analyzing sound insulation was used frequency range from 50 Hz to 10 kHz via stan... This paper reports on an evaluation of airborne sound insulation in a wider frequency range then is used in classical measurements. For analyzing sound insulation was used frequency range from 50 Hz to 10 kHz via standard range I00 Hz to 3,15 kHz. For four constructions with different structure was measured sound reduction index depend on frequency and calculated Weighted sound reduction index according to EN ISO 717-1. Then the results were compared. The measurements were made for samples of construction with different sizes. The results of measurements show how the size of sample influence on measured sound insulation. This article could be useful for specialist of architect acoustic and all who interest in sound insulation. 展开更多
关键词 Sound insulation airborne noise frequency range partition.
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Studying surface structure in desert areas using multiple kinds of surface wave data 被引量:1
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作者 Cheng Suo Gang Tian Zhanjie Shi 《Applied Geophysics》 SCIE CSCD 2007年第1期1-7,共7页
Shallow surface wave methods are mostly used for investigation of the surface velocity structure in environmental and engineering geophysics in non-desert areas. For the special geological features of the Takelamagan ... Shallow surface wave methods are mostly used for investigation of the surface velocity structure in environmental and engineering geophysics in non-desert areas. For the special geological features of the Takelamagan Desert area, we use the multi-channel analysis of surface wave (MASW) method to process multi-channel shallow surface wave records to determine the near surface velocity structure in the desert area. We also process, analyze, and compare the surface waves in many-trace records extracted from the oil exploration shot gathers in the area. We show that the MASW method can determine detailed shallow velocity structure in desert areas and the many-trace records can be used to get detailed deep geological structure. The combination of the two different datasets can obtain the exact velocity structure upper 60 m depth in the survey area. 展开更多
关键词 desert area near surface structure shot records multi-channel analysis of surface wave.
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Study on Life Prediction Model of Concrete Dam Based on Dry Zoning and Damage Theory
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作者 Hui Peng 《Journal of Environmental Science and Engineering(A)》 2012年第10期1226-1230,共5页
Concrete dam construction, reservoir impoundment and operation are a complicated and long-term process. During the course of this process dam suffers lots of factors including changing temperature, humidity, deformati... Concrete dam construction, reservoir impoundment and operation are a complicated and long-term process. During the course of this process dam suffers lots of factors including changing temperature, humidity, deformation, loads and restraints around dam. With time going by, damage to darn concrete happens. As a result, the strength, stiffness and resistance of concrete will decrease accompanying with damage accumulation and dam structure performance behavior and lifetime will be shorten or even destructed. At present, most of researches focus on concrete material itself and seldom consider effects of water content for concrete structures. That is apparently inconsistent with the actual situation. In engineering practice, it is urgently needed to assess existing dam structure damage state considering dry zoning in concrete. Through taking C30 dam concrete as standard specimen, alternate freezing and thawing tests are undertaken and changing law of time-dependent concrete damage state resulting in alternate wetting and drying has been studied in this paper. And then calculation formulas of time-dependent concrete damage evolution process considering alternate wetting and drying under condition of freeze-thaw cycle tests are established. Combining with four parameters Hsieh-Ting-Chen ( H -T-C ) model, some relevant factors or parameters are obtained through indoor testing and life prediction model of concrete dam based on dry zoning and damage theory is put forward which provides technical supports for dam safety evaluation and management of sustainable development. 展开更多
关键词 Life prediction dry zoning damage theory concrete dam alternate freezing and thawing test
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Urban Integrated Activity Zone (UIAZ) in Shanghai
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作者 Shunyao Zhang Yi Chen 《Sociology Study》 2014年第11期965-973,共9页
Urban integrated activity zone (UIAZ) refers to multi-functional area that can provide various services. Integrated activity zone (IAZ), which is based on the existing financial district and Central Business Distr... Urban integrated activity zone (UIAZ) refers to multi-functional area that can provide various services. Integrated activity zone (IAZ), which is based on the existing financial district and Central Business District (CBD), often weakens administrative boundaries and changes the original single functional partition. It emphasizes the mixture of different functions and the vitality of the central area. The construction of IAZ is different from the simple space construction of economy and material production. IAZ emphasizes the participation of city dwellers in urban renewal process. Shanghai IAZs are those vigorous public activity centers in Shanghai. ]ust like those active cells, IAZs in Shanghai are to inspire and improve the comprehensive competitiveness and vitality of the city at macro, intermediate, and micro level, they are the public places in which urban cultural life takes place, develops, and precipitates. This paper provides broad and profound presentation on IAZ structure planning in Shanghai: mix-used function, multi-dimensions scale, people oriented development (POD) transportation, commercial development, and city form vitality. This paper provides not only qualitative analysis, but also makes a serious attempt to quantify the result and statement. 展开更多
关键词 Integrated activity zone (IAZ) mix-used function city vitality
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Suburbanization and Subcentering of Population in Beijing Metropolitan Area:A Nonparametric Analysis 被引量:3
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作者 SUN Tieshan HAN Zhenhai +1 位作者 WANG Lanlan LI Guoping 《Chinese Geographical Science》 SCIE CSCD 2012年第4期472-482,共11页
This study focuses on the suburbanization and subcentering of population and examines the nature of spatial restructuring in terms of the population distribution in the Beijing metropolitan area.Instead of the classic... This study focuses on the suburbanization and subcentering of population and examines the nature of spatial restructuring in terms of the population distribution in the Beijing metropolitan area.Instead of the classic density function approach,we employ the nonparametric analysis to characterize the spatial pattern of population densities in the Beijing metropolitan area and identify the suburban subcenters.Our findings suggest that the population has spread with rapid urban growth in the Beijing metropolitan area,and the compact urban form has been replaced by a more dispersed polycentric spatial distribution.However,compared with the decentralization of western cities,the spatial extent of the decentralization of population in the Beijing metropolitan area is quite limited.The rapid growth of population in the near suburbs has expedited the sprawl of the central city,with a larger central agglomeration of population dominating the metropolitan area.In this sense,the spatial pattern of the Beijing metropolitan area is still characterized by the continuous compactness.However,our findings do provide the evidence that the city has been turning to a polycentric structure.We find significant population subcenters have emerged in the suburbs of Beijing since the 1980s.But the polycentricity emerged in the Beijing metropolitan area is very different by nature from that observed in Western cities.The subcenters emerged are adherent to the development scheme planned for the city,so it can be referred to as the so called 'planned polycentricity'. 展开更多
关键词 SUBURBANIZATION population subcenters POLYCENTRICITY urban spatial structure Beijing metropolitan area
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浅谈“自由人联合体”——学习《资本论》和《法兰西内战》笔记
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作者 吴威 寇平 《经济理论与经济管理》 1983年第5期60-63,42,共5页
马克思说:“不论生产的社会形式如何,劳动者和生产资料始终是生产的因素。但是,二者在彼此分离的情况下只在可能性上是生产因素。凡要进行生产,就必须使它们结合起来。实行这种结合的特殊方式和方法,使社会结构区分为各个不同的经济时... 马克思说:“不论生产的社会形式如何,劳动者和生产资料始终是生产的因素。但是,二者在彼此分离的情况下只在可能性上是生产因素。凡要进行生产,就必须使它们结合起来。实行这种结合的特殊方式和方法,使社会结构区分为各个不同的经济时期。”(《资本论》第2卷,第44页)马克思正是根据这个思想,在《资本论》 展开更多
关键词 《资本论》 “自由人联合体” 马克思 法兰西内战 生产资料 资本主义 劳动者 生产因素 社会形式 结构区分
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