活动介绍

yum -y update Loaded plugins: fastestmirror, langpacks Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7

时间: 2025-07-24 18:12:03 浏览: 56
<think>我们面对的问题是:在使用`yum update`时出现mirrorlist下载失败的错误,具体是`http://mirrorlist.centos.org/?release=7`无法访问。根据引用内容,这通常是因为网络问题或镜像源不可用。解决方法是更换镜像源,比如使用阿里云的镜像源。 根据引用[1][2][3][4],步骤都是类似的: 1. 备份原有的yum源配置文件。 2. 下载新的CentOS-Base.repo(这里我们使用阿里云的CentOS 7镜像源)。 3. 清理yum缓存并重新生成缓存。 具体步骤: 1. **备份当前yum源**: ```bash sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup ``` 2. **下载新的CentOS-Base.repo**: 可以使用`wget`或`curl`命令。这里以`curl`为例(如果没有`curl`,可以先安装或者使用`wget`): ```bash sudo curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo ``` 或者使用`wget`: ```bash sudo wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo ``` 3. **清理缓存并重新生成**: ```bash sudo yum clean all sudo yum makecache ``` 4. **再次尝试更新**: ```bash sudo yum update ``` 注意:如果系统是CentOS 8,则应该使用对应的CentOS 8的镜像源。但根据问题中提到的`release=7`,说明是CentOS 7。 另外,引用[2]和[4]也提到了使用阿里云的镜像源,步骤一致。 如果上述步骤后问题仍然存在,可以检查网络连接,或者尝试其他镜像源(如腾讯云、华为云等)。 最后,生成相关问题。</think>### 解决 yum update 时 mirrorlist 下载失败问题 当在 CentOS 7 中执行 `yum update` 出现 `mirrorlist download failed` 错误时,通常是因为默认镜像源不可用。以下是完整解决方案: #### 解决步骤 1. **备份原有配置**(防止操作失误) ```bash sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup ``` 2. **下载阿里云镜像源**(替换失效源) ```bash sudo curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo ``` 或使用 wget: ```bash sudo wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo ``` 3. **清理并重建缓存** ```bash sudo yum clean all # 清除旧缓存 sudo yum makecache # 重建新缓存 sudo yum update # 测试更新 ``` 4. **验证结果** 成功执行 `yum update` 且无报错即修复完成[^1][^2][^3][^4]。 #### 关键说明 - 镜像源失效原因:CentOS 官方已停止维护(2024年6月后),需切换第三方源 - 阿里云源优势:国内访问稳定,包含完整软件包 - 若仍失败:检查网络连接或尝试其他镜像(如腾讯云源)
阅读全文

相关推荐

[jiahui@localhost ~]$ su root Password: [root@localhost jiahui]# sudo yum install -y yum-utils Loaded plugins: fastestmirror, langpacks Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true Cannot find a valid baseurl for repo: base/7/x86_64

(django) [root@iZ7vhr6bkd1v9kZ django]# sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-SCLo-scl.repo (django) [root@iZ7vhr6bkd1v9kZ django]# sed -i 's|#baseurl=http://mirror.centos.org/centos|baseurl=https://mirrors.aliyun.com/centos|g' /etc/yum.repos.d/CentOS-SCLo-scl.repo (django) [root@iZ7vhr6bkd1v9kZ django]# yum clean all && yum makecache Loaded plugins: fastestmirror Cleaning repos: base centos-sclo-rh centos-sclo-sclo epel extras mysql-connectors-community mysql-tools-community mysql57-community : updates Cleaning up list of fastest mirrors Loaded plugins: fastestmirror Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org?arch=x86_64&release=7&repo=sclo-rh error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true Cannot find a valid baseurl for repo: centos-sclo-rh/x86_64

[root@localhost ~]# yum -y install gcc* Loaded plugins: fastestmirror Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true Cannot find a valid baseurl for repo: base/7/x86_64

[root@cc dockfile]# docker build -t zhangsan . Sending build context to Docker daemon 2.048 kB Step 1/4 : FROM centos:7 ---> eeb6ee3f44bd Step 2/4 : MAINTAINER Macao<[email protected]> ---> Running in 6d911292fdda ---> d61e3702af41 Removing intermediate container 6d911292fdda Step 3/4 : RUN yum -y install vim net-tools ---> Running in 95bb5a65df0f Loaded plugins: fastestmirror, ovl Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=container error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manag

[root@VM-4-6-centos usr]# yum makecache # 生成新缓存 Loaded plugins: fastestmirror, langpacks Repository centos-sclo-rh is listed more than once in the configuration Repository epel is listed more than once in the configuration Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org?arch=x86_64&release=7&repo=sclo-sclo error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Name or service not known" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true Cannot find a valid baseurl for repo: centos-sclo-sclo/x86_64 国内镜像已经更新,还是出错

yum makecache Loaded plugins: fastestmirror Repository base is listed more than once in the configuration Repository extras is listed more than once in the configuration Repository centosplus is listed more than once in the configuration Repository epel is listed more than once in the configuration Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org?arch=x86_64&release=7&repo=sclo-rh error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true Cannot find a valid baseurl for repo: centos-sclo-r

=> ERROR [2/6] RUN yum install -y java-17-openjdk-devel 2.5s ------ > [2/6] RUN yum install -y java-17-openjdk-devel: 1.858 Loaded plugins: fastestmirror, ovl 2.200 Determining fastest mirrors 2.265 Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=container error was 2.265 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" 2.284 2.284 2.284 One of the configured repositories failed (Unknown), 2.284 and yum doesn't have enough cached data to continue. At this point the only 2.284 safe thing yum can do is fail. There are a few ways to work "fix" this: 2.284 2.284 1. Contact the upstream for the repository and get them to fix the problem. 2.284 2.284 2. Reconfigure the baseurl/etc. for the repository, to point to a working 2.284 upstream. This is most often useful if you are using a newer 2.284 distribution release than is supported by the repository (and the 2.284 packages for the previous distribution release still work). 2.284 2.284 3. Run the command with the repository temporarily disabled 2.284 yum --disablerepo=<repoid> ... 2.284 2.284 4. Disable the repository permanently, so yum won't use it by default. Yum 2.284 will then just ignore the repository until you permanently enable it 2.284 again or use --enablerepo for temporary usage: 2.284 2.284 yum-config-manager --disable <repoid> 2.284 or 2.284 subscription-manager repos --disable=<repoid> 2.284 2.284 5. Configure the failing repository to be skipped, if it is unavailable. 2.284 Note that yum will try to contact the repo. when it runs most commands, 2.284 so will have to try and fail each time (and thus. yum will be be much 2.284 slower). If it is a very temporary problem though, this is often a nice 2.284 compromise: 2.284 2.284 yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true 2.284 2.284 Cannot find a valid baseurl for repo: base/7/x86_64 ------ Dockerfile:5 -------------------- 3 | 4 | # 安装完整 JDK(必须包含 -devel 包) 5 | >>> RUN yum install -y java-17-openjdk-devel 6 | 7 | # 设置环境变量(使用标准路径) -------------------- ERROR: failed to solve: process "/bin/sh -c yum install -y java-17-openjdk-devel" did not complete successfully: exit code: 1

[root@node3 ~]# cat Dockerfile FROM centos:7 MAINTAINER ljy<[email protected] ENV MYPATH /usr/local WORKDIR $MYPATH RUN yum -y install vim RUN yum -y install net-tools RUN yum -y install glibc.i686 RUN mkdir /usr/local/java ADD jdk-8u171-linux-x64.tar.gz /usr/local/java/ ENV JAVA_HOME /usr/local/java/jdk1.8.0_171 ENV JRE_HOME $JAVA_HOME/jre ENV CLASSPATH $JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib:$CLASSPATH ENV PATH $JAVA_HOME/bin:$PATH EXPOSE 80 CMD echo $MYPATH CMD echo "success----------ok" CMD /bin/bash [root@node3 ~]# docker build -t ImageName:TagName dir invalid argument "ImageName:TagName" for "-t, --tag" flag: invalid reference format: repository name must be lowercase See 'docker build --help'. [root@node3 ~]# docker build -t contosjava8:1.5 . Sending build context to Docker daemon 218.7MB Step 1/17 : FROM centos:7 ---> eeb6ee3f44bd Step 2/17 : MAINTAINER ljy<[email protected] ---> Running in 4ce77aa6b7e0 Removing intermediate container 4ce77aa6b7e0 ---> 85ad4a293894 Step 3/17 : ENV MYPATH /usr/local ---> Running in 91b300712ad5 Removing intermediate container 91b300712ad5 ---> c23361382ec7 Step 4/17 : WORKDIR $MYPATH ---> Running in fc714342b069 Removing intermediate container fc714342b069 ---> 2abf3bdd31a9 Step 5/17 : RUN yum -y install vim ---> Running in 9d075b11d3e3 Loaded plugins: fastestmirror, ovl Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=container error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true Cannot find a valid baseurl for repo: base/7/x86_64 The command '/bin/sh -c yum -y install vim' returned a non-zero code: 1 帮我改进一下

yum install tree -y 已加载插件:fastestmirror, langpacks Loading mirror speeds from cached hostfile Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; 未知的错误" One of the configured repositories failed (未知), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true Cannot find a valid baseurl for repo: base/7/x86_64 如何解决

[root@localhost ~]# yum -y install net-tools 已加载插件:fastestmirror Loading mirror speeds from cached hostfile Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; 未知的错误" One of the configured repositories failed (未知), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true Cannot find a valid baseurl for repo: base/7/x86_64

zip
JFM7VX690T型SRAM型现场可编程门阵列技术手册主要介绍的是上海复旦微电子集团股份有限公司(简称复旦微电子)生产的高性能FPGA产品JFM7VX690T。该产品属于JFM7系列,具有现场可编程特性,集成了功能强大且可以灵活配置组合的可编程资源,适用于实现多种功能,如输入输出接口、通用数字逻辑、存储器、数字信号处理和时钟管理等。JFM7VX690T型FPGA适用于复杂、高速的数字逻辑电路,广泛应用于通讯、信息处理、工业控制、数据中心、仪表测量、医疗仪器、人工智能、自动驾驶等领域。 产品特点包括: 1. 可配置逻辑资源(CLB),使用LUT6结构。 2. 包含CLB模块,可用于实现常规数字逻辑和分布式RAM。 3. 含有I/O、BlockRAM、DSP、MMCM、GTH等可编程模块。 4. 提供不同的封装规格和工作温度范围的产品,便于满足不同的使用环境。 JFM7VX690T产品系列中,有多种型号可供选择。例如: - JFM7VX690T80采用FCBGA1927封装,尺寸为45x45mm,使用锡银焊球,工作温度范围为-40°C到+100°C。 - JFM7VX690T80-AS同样采用FCBGA1927封装,但工作温度范围更广,为-55°C到+125°C,同样使用锡银焊球。 - JFM7VX690T80-N采用FCBGA1927封装和铅锡焊球,工作温度范围与JFM7VX690T80-AS相同。 - JFM7VX690T36的封装规格为FCBGA1761,尺寸为42.5x42.5mm,使用锡银焊球,工作温度范围为-40°C到+100°C。 - JFM7VX690T36-AS使用锡银焊球,工作温度范围为-55°C到+125°C。 - JFM7VX690T36-N使用铅锡焊球,工作温度范围与JFM7VX690T36-AS相同。 技术手册中还包含了一系列详细的技术参数,包括极限参数、推荐工作条件、电特性参数、ESD等级、MSL等级、重量等。在产品参数章节中,还特别强调了封装类型,包括外形图和尺寸、引出端定义等。引出端定义是指对FPGA芯片上的各个引脚的功能和接线规则进行说明,这对于FPGA的正确应用和电路设计至关重要。 应用指南章节涉及了FPGA在不同应用场景下的推荐使用方法。其中差异说明部分可能涉及产品之间的性能差异;关键性能对比可能包括功耗与速度对比、上电浪涌电流测试情况说明、GTH Channel Loss性能差异说明、GTH电源性能差异说明等。此外,手册可能还提供了其他推荐应用方案,例如不使用的BANK接法推荐、CCLK信号PCB布线推荐、JTAG级联PCB布线推荐、系统工作的复位方案推荐等,这些内容对于提高系统性能和稳定性有着重要作用。 焊接及注意事项章节则针对产品的焊接过程提供了指导,强调焊接过程中的注意事项,以确保产品在组装过程中的稳定性和可靠性。手册还明确指出,未经复旦微电子的许可,不得翻印或者复制全部或部分本资料的内容,且不承担采购方选择与使用本文描述的产品和服务的责任。 上海复旦微电子集团股份有限公司拥有相关的商标和知识产权。该公司在中国发布的技术手册,版权为上海复旦微电子集团股份有限公司所有,未经许可不得进行复制或传播。 技术手册提供了上海复旦微电子集团股份有限公司销售及服务网点的信息,方便用户在需要时能够联系到相应的服务机构,获取最新信息和必要的支持。同时,用户可以访问复旦微电子的官方网站(***以获取更多产品信息和公司动态。

大家在看

recommend-type

Xilinx ISE rs_decoder_ipcore and encoder License

Xilinx ISE RS编码解码IP核的License
recommend-type

毕业设计&课设-一个基于Matlab的PET仿真和重建框架,具有系统矩阵的分析建模,能够结合各种数据….zip

matlab算法,工具源码,适合毕业设计、课程设计作业,所有源码均经过严格测试,可以直接运行,可以放心下载使用。有任何使用问题欢迎随时与博主沟通,第一时间进行解答! matlab算法,工具源码,适合毕业设计、课程设计作业,所有源码均经过严格测试,可以直接运行,可以放心下载使用。有任何使用问题欢迎随时与博主沟通,第一时间进行解答! matlab算法,工具源码,适合毕业设计、课程设计作业,所有源码均经过严格测试,可以直接运行,可以放心下载使用。有任何使用问题欢迎随时与博主沟通,第一时间进行解答! matlab算法,工具源码,适合毕业设计、课程设计作业,所有源码均经过严格测试,可以直接运行,可以放心下载使用。有任何使用问题欢迎随时与博主沟通,第一时间进行解答! matlab算法,工具源码,适合毕业设计、课程设计作业,所有源码均经过严格测试,可以直接运行,可以放心下载使用。有任何使用问题欢迎随时与博主沟通,第一时间进行解答! matlab算法,工具源码,适合毕业设计、课程设计作业,所有源码均经过严格测试,可以直接运行,可以放心下载使用。有任何使用问题欢迎随
recommend-type

MATLAB机械臂简单控制仿真(Simulink篇-总).zip

MATLAB下机器人可视化与控制---simulink篇中的简单例子,在Simulink中做了预定义轨迹的运动和Slider Gain控制的运动,用GUI控制的关节代码在MATLAB下机器人可视化与控制
recommend-type

使用 GCC 构建 STM23F0 ARM 项目的模板源码

使用 GCC 构建 STM23F0 ARM 项目的模板源码,具体请看 README
recommend-type

详细说明 VC++的MFC开发串口调试助手源代码,包括数据发送,接收,显示制式等29782183com

详细说明 VC++的MFC开发串口调试助手源代码,包括数据发送,接收,显示制式等29782183com

最新推荐

recommend-type

计算机网络学习中学员常见问题与改进方法

计算机网络学习中学员常见问题与改进方法+
recommend-type

基于高斯混合模型(GMM)和主成分分析(PCA)的疲劳语音识别.zip

1.版本:matlab2014a/2019b/2024b 2.附赠案例数据可直接运行。 3.代码特点:参数化编程、参数可方便更改、代码编程思路清晰、注释明细。 4.适用对象:计算机,电子信息工程、数学等专业的大学生课程设计、期末大作业和毕业设计。
recommend-type

Java毕业设计基于SpringBoot+Vue开发的智慧农业系统源码+数据库(高分项目)

Java毕业设计基于SpringBoot+Vue开发的智慧农业系统源码+数据库(高分项目),个人大四的毕业设计、经导师指导并认可通过的高分设计项目,评审分99分,代码完整确保可以运行,小白也可以亲自搞定,主要针对计算机相关专业的正在做毕设的学生和需要项目实战练习的学习者,也可作为课程设计、期末大作业。 Java毕业设计基于SpringBoot+Vue开发的智慧农业系统源码+数据库(高分项目)Java毕业设计基于SpringBoot+Vue开发的智慧农业系统源码+数据库(高分项目)Java毕业设计基于SpringBoot+Vue开发的智慧农业系统源码+数据库(高分项目)Java毕业设计基于SpringBoot+Vue开发的智慧农业系统源码+数据库(高分项目)Java毕业设计基于SpringBoot+Vue开发的智慧农业系统源码+数据库(高分项目)Java毕业设计个人大四的毕业设计、经导师指导并认可通过的高分设计项目,评审分99分,代码完整确保可以运行,小白也可以亲自搞定,主要针对计算机相关专业的正在做毕设的学生和需要项目实战练习的学习者,也可作为课程设计、期末大作业。个人大四的毕业设计 收起
recommend-type

用bp神经网络预测油田产量

资源下载链接为: https://pan.quark.cn/s/82cb66f4d6b4 用bp神经网络预测油田产量(最新、最全版本!打开链接下载即可用!)
recommend-type

2_JFM7VX690T型SRAM型现场可编程门阵列技术手册.pdf

JFM7VX690T型SRAM型现场可编程门阵列技术手册主要介绍的是上海复旦微电子集团股份有限公司(简称复旦微电子)生产的高性能FPGA产品JFM7VX690T。该产品属于JFM7系列,具有现场可编程特性,集成了功能强大且可以灵活配置组合的可编程资源,适用于实现多种功能,如输入输出接口、通用数字逻辑、存储器、数字信号处理和时钟管理等。JFM7VX690T型FPGA适用于复杂、高速的数字逻辑电路,广泛应用于通讯、信息处理、工业控制、数据中心、仪表测量、医疗仪器、人工智能、自动驾驶等领域。 产品特点包括: 1. 可配置逻辑资源(CLB),使用LUT6结构。 2. 包含CLB模块,可用于实现常规数字逻辑和分布式RAM。 3. 含有I/O、BlockRAM、DSP、MMCM、GTH等可编程模块。 4. 提供不同的封装规格和工作温度范围的产品,便于满足不同的使用环境。 JFM7VX690T产品系列中,有多种型号可供选择。例如: - JFM7VX690T80采用FCBGA1927封装,尺寸为45x45mm,使用锡银焊球,工作温度范围为-40°C到+100°C。 - JFM7VX690T80-AS同样采用FCBGA1927封装,但工作温度范围更广,为-55°C到+125°C,同样使用锡银焊球。 - JFM7VX690T80-N采用FCBGA1927封装和铅锡焊球,工作温度范围与JFM7VX690T80-AS相同。 - JFM7VX690T36的封装规格为FCBGA1761,尺寸为42.5x42.5mm,使用锡银焊球,工作温度范围为-40°C到+100°C。 - JFM7VX690T36-AS使用锡银焊球,工作温度范围为-55°C到+125°C。 - JFM7VX690T36-N使用铅锡焊球,工作温度范围与JFM7VX690T36-AS相同。 技术手册中还包含了一系列详细的技术参数,包括极限参数、推荐工作条件、电特性参数、ESD等级、MSL等级、重量等。在产品参数章节中,还特别强调了封装类型,包括外形图和尺寸、引出端定义等。引出端定义是指对FPGA芯片上的各个引脚的功能和接线规则进行说明,这对于FPGA的正确应用和电路设计至关重要。 应用指南章节涉及了FPGA在不同应用场景下的推荐使用方法。其中差异说明部分可能涉及产品之间的性能差异;关键性能对比可能包括功耗与速度对比、上电浪涌电流测试情况说明、GTH Channel Loss性能差异说明、GTH电源性能差异说明等。此外,手册可能还提供了其他推荐应用方案,例如不使用的BANK接法推荐、CCLK信号PCB布线推荐、JTAG级联PCB布线推荐、系统工作的复位方案推荐等,这些内容对于提高系统性能和稳定性有着重要作用。 焊接及注意事项章节则针对产品的焊接过程提供了指导,强调焊接过程中的注意事项,以确保产品在组装过程中的稳定性和可靠性。手册还明确指出,未经复旦微电子的许可,不得翻印或者复制全部或部分本资料的内容,且不承担采购方选择与使用本文描述的产品和服务的责任。 上海复旦微电子集团股份有限公司拥有相关的商标和知识产权。该公司在中国发布的技术手册,版权为上海复旦微电子集团股份有限公司所有,未经许可不得进行复制或传播。 技术手册提供了上海复旦微电子集团股份有限公司销售及服务网点的信息,方便用户在需要时能够联系到相应的服务机构,获取最新信息和必要的支持。同时,用户可以访问复旦微电子的官方网站(***以获取更多产品信息和公司动态。
recommend-type

美国国际航空交通数据分析报告(1990-2020)

根据给定的信息,我们可以从中提取和分析以下知识点: 1. 数据集概述: 该数据集名为“U.S. International Air Traffic data(1990-2020)”,记录了美国与国际间航空客运和货运的详细统计信息。数据集涵盖的时间范围从1990年至2020年,这说明它包含了长达30年的时间序列数据,对于进行长期趋势分析非常有价值。 2. 数据来源及意义: 此数据来源于《美国国际航空客运和货运统计报告》,该报告是美国运输部(USDOT)所管理的T-100计划的一部分。T-100计划旨在收集和发布美国和国际航空公司在美国机场的出入境交通报告,这表明数据的权威性和可靠性较高,适用于政府、企业和学术研究等领域。 3. 数据内容及应用: 数据集包含两个主要的CSV文件,分别是“International_Report_Departures.csv”和“International_Report_Passengers.csv”。 a. International_Report_Departures.csv文件可能包含了以下内容: - 离港航班信息:记录了各航空公司的航班号、起飞和到达时间、起飞和到达机场的代码以及国际地区等信息。 - 航空公司信息:可能包括航空公司代码、名称以及所属国家等。 - 飞机机型信息:如飞机类型、座位容量等,这有助于分析不同机型的使用频率和趋势。 - 航线信息:包括航线的起始和目的国家及城市,对于研究航线网络和优化航班计划具有参考价值。 这些数据可以用于航空交通流量分析、机场运营效率评估、航空市场分析等。 b. International_Report_Passengers.csv文件可能包含了以下内容: - 航班乘客信息:可能包括乘客的国籍、年龄、性别等信息。 - 航班类型:如全客机、全货机或混合型航班,可以分析乘客运输和货物运输的比例。 - 乘客数量:记录了各航班或航线的乘客数量,对于分析航空市场容量和增长趋势很有帮助。 - 飞行里程信息:有助于了解国际间不同航线的长度和飞行距离,为票价设置和燃油成本分析提供数据支持。 这些数据可以用于航空客运市场分析、需求预测、收益管理等方面。 4. 数据分析和应用实例: - 航空流量分析:通过分析离港航班数据,可以观察到哪些航线最为繁忙,哪些机场的国际航空流量最大,这有助于航空公司调整航班时刻表和运力分配。 - 市场研究:乘客数据可以揭示不同国家和地区之间的人口流动趋势,帮助航空公司和政府机构了解国际旅行市场的需求变化。 - 飞机利用率:结合飞机机型和飞行频率信息,可以对特定机型的使用率进行分析,评估飞机维护需求和燃油效率。 - 安全监管:通过对比不同航空公司和航班的安全记录,监管机构可以更有效地评估航空公司的安全性能,并采取必要的监管措施。 5. 技术和方法论: 分析此类数据通常涉及数据清洗、数据整合、统计分析、时间序列分析、预测建模等数据科学方法。使用Excel、SQL、R、Python等工具进行数据处理和分析是常见的做法。例如,可以使用Python的Pandas库来清洗和准备数据,使用Matplotlib和Seaborn库来可视化数据,然后利用Scikit-learn或Statsmodels库来构建预测模型。 通过以上知识点的提取和分析,我们可以理解到“U.S. International Air Traffic data(1990-2020)-数据集”的重要性,它不仅记录了跨越30年的航空交通数据,还为各种分析和应用提供了详实的基础信息。对于航空业从业者、政策制定者、研究人员以及数据分析师来说,这是一个极具价值的数据资源。
recommend-type

统计学视角:深入理解最小二乘法的概率论基础

# 1. 最小二乘法的基本概念 最小二乘法(Least Squares Method, LSM)是统计学和数据分析中广泛使用的一种数学优化技术。其主要目的是通过最小化误差的平方和来寻找数据的最佳函数匹配。这种方法最早由高斯提出,但在工程、物理、经济和其他领域中有着广泛的应用。 在本章中,我们将首先了
recommend-type

vscode中使用Codeium

<think>好的,我需要回答用户如何在VSCode中使用Codeium插件的问题。首先,我需要回顾用户提供的引用内容,看看是否有相关信息。用户提供的引用[1]提到了Codeium Chat可以解释代码中的问题,引用[2]提到了在IDEA中的一些问题,可能对VSCode的安装有帮助。用户还提到了安装步骤、基本功能、常见问题等。 首先,我应该分步骤说明安装过程,包括在VSCode扩展商店搜索Codeium并安装。然后,登录部分可能需要用户访问仪表板获取API密钥,引用[2]中提到登录问题,可能需要提醒用户注意网络或权限设置。 接下来是基本功能,比如代码自动补全和Chat功能。引用[1]提到C
recommend-type

UniMoCo:统一框架下的多监督视觉学习方法

在详细解析“unimoco”这个概念之前,我们需要明确几个关键点。首先,“unimoco”代表的是一种视觉表示学习方法,它在机器学习尤其是深度学习领域中扮演着重要角色。其次,文章作者通过这篇论文介绍了UniMoCo的全称,即“Unsupervised, Semi-Supervised and Full-Supervised Visual Representation Learning”,其背后的含义是在于UniMoCo框架整合了无监督学习、半监督学习和全监督学习三种不同的学习策略。最后,该框架被官方用PyTorch库实现,并被提供给了研究者和开发者社区。 ### 1. 对比学习(Contrastive Learning) UniMoCo的概念根植于对比学习的思想,这是一种无监督学习的范式。对比学习的核心在于让模型学会区分不同的样本,通过将相似的样本拉近,将不相似的样本推远,从而学习到有效的数据表示。对比学习与传统的分类任务最大的不同在于不需要手动标注的标签来指导学习过程,取而代之的是从数据自身结构中挖掘信息。 ### 2. MoCo(Momentum Contrast) UniMoCo的实现基于MoCo框架,MoCo是一种基于队列(queue)的对比学习方法,它在训练过程中维持一个动态的队列,其中包含了成对的负样本。MoCo通过 Momentum Encoder(动量编码器)和一个队列来保持稳定和历史性的负样本信息,使得模型能够持续地进行对比学习,即使是在没有足够负样本的情况下。 ### 3. 无监督学习(Unsupervised Learning) 在无监督学习场景中,数据样本没有被标记任何类别或标签,算法需自行发现数据中的模式和结构。UniMoCo框架中,无监督学习的关键在于使用没有标签的数据进行训练,其目的是让模型学习到数据的基础特征表示,这对于那些标注资源稀缺的领域具有重要意义。 ### 4. 半监督学习(Semi-Supervised Learning) 半监督学习结合了无监督和有监督学习的优势,它使用少量的标注数据与大量的未标注数据进行训练。UniMoCo中实现半监督学习的方式,可能是通过将已标注的数据作为对比学习的一部分,以此来指导模型学习到更精准的特征表示。这对于那些拥有少量标注数据的场景尤为有用。 ### 5. 全监督学习(Full-Supervised Learning) 在全监督学习中,所有的训练样本都有相应的标签,这种学习方式的目的是让模型学习到映射关系,从输入到输出。在UniMoCo中,全监督学习用于训练阶段,让模型在有明确指示的学习目标下进行优化,学习到的任务相关的特征表示。这通常用于有充足标注数据的场景,比如图像分类任务。 ### 6. PyTorch PyTorch是一个开源机器学习库,由Facebook的人工智能研究团队开发,主要用于计算机视觉和自然语言处理等任务。它被广泛用于研究和生产环境,并且因其易用性、灵活性和动态计算图等特性受到研究人员的青睐。UniMoCo官方实现选择PyTorch作为开发平台,说明了其对科研社区的支持和对易于实现的重视。 ### 7. 可视化表示学习(Visual Representation Learning) 可视化表示学习的目的是从原始视觉数据中提取特征,并将它们转换为能够反映重要信息且更易于处理的形式。在UniMoCo中,无论是无监督、半监督还是全监督学习,最终的目标都是让模型学习到有效的视觉表示,这些表示可以用于下游任务,如图像分类、目标检测、图像分割等。 ### 8. 标签队列(Label Queue) UniMoCo通过标签队列维护受监管的标签,这可能意味着对于那些半监督或全监督学习的任务,模型在进行对比学习时,会参考这些来自标签队列的数据。标签队列机制能帮助模型更好地利用有限的标注数据,增强模型的泛化能力。 ### 结论 UniMoCo的提出,以及其官方PyTorch实现的发布,将对计算机视觉领域产生深远影响。它不仅提供了一个统一的对比学习框架,使得从无监督到全监督的学习过程更加灵活和高效,而且为研究者们提供了一个强力的工具,以便更好地探索和实现各种视觉任务。UniMoCo的研究和应用前景,为机器学习尤其是深度学习在视觉领域的研究和实践提供了新的视角和可能。
recommend-type

【MATLAB算法精讲】:最小二乘法的实现与案例深度分析

# 1. 最小二乘法的基本原理 最小二乘法是一种数学优化技术,它通过最小化误差的平方和来寻找数据的最佳函数匹配。其核心思想是选择一条曲线,使得所有观察点到这条曲线的距离之和最小。这种方法广泛应用于统计学、信号处理、工程学和经济学等领域,尤其适用于需要通过一组数据点来确定函数参数的情况。 ## 1.1 统计学视角下的最小二乘法 在统计学中,最小二乘法经常用于