2.2 Cokriging模型 Cokriging 模型是上个世纪 70 年代发展起来 的一种更有效的地质统计学插值模型 [91]-[95] 。在 地质统计学领域，为了提高对某个抽样比较困难 的量的预测精度，提出了采用更容易抽样的量进 行辅助预测的 kriging 模型，称为 cokriging 模型 [92] 。2000 年，Kennedy 和 O’Hagan[96]首次将 cokriging 模型推广应用于工程科学领域，发展了 一种采用低可信度计算机程序结果，来辅助预测 高可信度计算机程序结果的 cokriging 方法。目前 国际上对 cokriging 模型的研究主要集中在地质统 计学和数学统计学等领域，在航空航天等工程科 学领域的研究也逐渐得到重视 [14][97]-[101] 。 2010 年，文献[101]独立提出了一种可用于 建立变可信度代理模型的实用 cokriging 模型（也 参见[14]）。下面对该模型进行介绍。 对于一个具有 m 个设计变量的优化问题， 在设计空间中同时采用高可信度分析（例如 NS 方程或密网格数值模拟）和低可信度分析（例如 Euler 方程或疏网格数值模拟）进行抽样，并建 立所谓的变可信度代理模型。更多建立变可信度 模型的方法请参见文献[88]。变可信度代理模型 在达到相同近似精度的条件下，可显著提高建立 代理模型的效率。 假设高、低可信度分析程序的抽样位置如下 1 1 2 2 ( )(1) T 1 1 1 ( )(1) T 2 2 2 ( ,..., ) ( ,..., )       S x x S x x   n n m n n m (40) 下标“1”和“2”分别代表高、低可信度，例如 1n 和 2n 分别代表高、低可信度样本点数（假设 2 1n n ）。相应的目标函数或约束函数的响应值 如下 1 1 2 2 ( )(1) T 1 1 1 ( )(1) T 2 2 2 [ ,..., ] , [ ,..., ] .     y y   n n n n y y y y (41) Cokriging 模型预估值定义如下 T T T 1 1 1 2 2ˆ ( )   x λ y λ y λ ySy , (42) 其中 1 2,λ λ 分别为对高、低可信度响应值的加权 系数。假设存在分别与 ,y y1 2 分别对应的 2 个 静态随机过程， ( ) ( ), ( ) ( ).       x x x x Y Z Y Z 1 1 1 2 2 2 (43) 则设计空间不同位置处，随机变量之间的协方差 和交叉协方差定义为 ( ) ( ) ( ) ( )2 (11) 11 1 1 1 ( ) ( ) ( ) ( )2 (22) 22 2 2 2 ( ) ( ) ( ) ( )(12) 1 21 2 1 2 ( ( ), ( )) ( , ) ( ( ), ( )) ( , ) ( ( ), ( )) ( , )        x x x x x x x x x x x x i j i j i j i j i j i j Cov Z Z R Cov Z Z R Cov Z Z R (44) 其中， 21 和 2 2 分别为随机过程 ( )xY1 和 ( )xY2 的过程方差。采用与 kriging 模型类似的推 导方法，可得到 cokriging 模型的预估值如下（具 体推导过程见文献[14]） T T 1 1 Sˆ ( ) ( ) ( )   x φ β r x R y Fβy ， (45) 其中 1 2 1T 1 1 T 11 S 22 1(11) (12) ( ) 2 S 1(21) (22) 2 2 ( )1 , ( ) , , ( )0 , , ,                                                r x φ β F R F F R y r r x y R R 1 0 R y F y 0 1R R      n n (46) 且有

带有随机回归系数线性模型中的最佳二次无偏估计，刘绪庆，吴延东，对带有随机回归系数线性模型中的联合二次函数的最佳二次无偏估计问题进行了讨论。

Unity插件上很好用的HTTP插件BEST HTTP 3，比unity自带unity web request强很多。

动手的RESTful API设计模式和最佳实践 这是Packt发布的“ 的代码存储库。 设计，开发和部署高度适应性，可扩展性和安全性的RESTful Web API 这本书是关于什么的？ 本书介绍了代表性状态传输（REST）范例，该范例是一种体系结构样式，允许联网的设备通过Internet相互通信。 在本书的帮助下，您将探索面向服务的体系结构（SOA），事件驱动的体系结构（EDA）和面向资源的体系结构（ROA）的概念。 本书涵盖了为什么需要高质量的API来进行企业集成。 本书涵盖以下激动人心的功能： 探索RESTful概念，包括URI，HATEOAS和按需编码 研究无状态，分页和可发现性等核心模式 使用API​​网关优化链接微服务的端点 深入研究API身份验证，授权和API安全性实施 与服务编排一起制定复合和流程感知服务 公开用于云计算的基于RESTful协议的API 如果您觉

yolov8 人脸检测数据集 一万张照片，300 epoch训练好的模型best.pt文件 准确率能达到百分之八十以上 预训练模型使用yolov8s, gpu3080ti训练两天

一款用于Http请求的轻量级Unity插件，同时也支持Socket协议，简小精悍，适合短连接的游戏和应用开发。

Many programmers code by instinct, relying on convenient habits or a "style" they picked up early on. They aren't conscious of all the choices they make, like how they format their source, the names they use for variables, or the kinds of loops they use. They're focused entirely on problems they're solving, solutions they're creating, and algorithms they're implementing. So they write code in the way that seems natural, that happens intuitively, and that feels good. But if you're serious about your profession, intuition isn't enough. Perl Best Practices author Damian Conway explains that rules, conventions, standards, and practices not only help programmers communicate and coordinate with one another, they also provide a reliable framework for thinking about problems, and a common language for expressing solutions. This is especially critical in Perl, because the language is designed to offer many ways to accomplish the same task, and consequently it supports many incompatible dialects. With a good dose of Aussie humor, Dr. Conway (familiar to many in the Perl community) offers 256 guidelines on the art of coding to help you write better Perl code--in fact, the best Perl code you possibly can. The guidelines cover code layout, naming conventions, choice of data and control structures, program decomposition, interface design and implementation, modularity, object orientation, error handling, testing, and debugging. They're designed to work together to produce code that is clear, robust, efficient, maintainable, and concise, but Dr. Conway doesn't pretend that this is the one true universal and unequivocal set of best practices. Instead, Perl Best Practices offers coherent and widely applicable suggestions based on real-world experience of how code is actually written, rather than on someone's ivory-tower theories on how software ought to be created. Most of all, Perl Best Practices offers guidelines that actually work, and that many developers around the world are already using. Much like Perl itself, these guidelines are about helping you to get your job done, without getting in the way. Praise for Perl Best Practices from Perl community members: "As a manager of a large Perl project, I'd ensure that every member of my team has a copy of Perl Best Practices on their desk, and use it as the basis for an in-house style guide." -- Randal Schwartz "There are no more excuses for writing bad Perl programs. All levels of Perl programmer will be more productive after reading this book." -- Peter Scott "Perl Best Practices will be the next big important book in the evolution of Perl. The ideas and practices Damian lays down will help bring Perl out from under the embarrassing heading of "scripting languages". Many of us have known Perl is a real programming language, worthy of all the tasks normally delegated to Java and C++. With Perl Best Practices, Damian shows specifically how and why, so everyone else can see, too." -- Andy Lester "Damian's done what many thought impossible: show how to build large, maintainable Perl applications, while still letting Perl be the powerful, expressive language that programmers have loved for years." -- Bill Odom "Finally, a means to bring lasting order to the process and product of real Perl development teams." -- Andrew Sundstrom"Perl Best Practices provides a valuable education in how to write robust, maintainable Perl, and is a definitive citation source when coaching other programmers." -- Bennett Todd "I've been teaching Perl for years, and find the same question keeps being asked: Where can I find a reference for writing reusable, maintainable Perl code? Finally I have a decent answer." -- Paul Fenwick "At last a well researched, well thought-out, comprehensive guide to Perl style. Instead of each of us developing our own, we can learn good practices from one of Perl's most prolific and experienced authors. I recommend this book to anyone who prefers getting on with the job rather than going back and fixing errors caused by syntax and poor style issues." -- Jacinta Richardson "If you care about programming in any language read this book. Even if you don't intend to follow all of the practices, thinking through your style will improve it." -- Steven Lembark "The Perl community's best author is back with another outstanding book. There has never been a comprehensive reference on high quality Perl coding and style until Perl Best Practices. This book fills a large gap in every Perl bookshelf." -- Uri Guttman

HTTP，Server-Sent Events，SignalR Core，Socket.IO，Socket.IO 3，Websocket通信。

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This classic book is the definitive real-world style guide for better Smalltalk programming. This author presents a set of patterns that organize all the informal experience successful Smalltalk programmers have learned the hard way. When programmers understand these patterns, they can write much more effective code. The concept of Smalltalk patterns is introduced, and the book explains why they work. Next, the book introduces proven patterns for working with methods, messages, state, collections, classes and formatting. Finally, the book walks through a development example utilizing patterns. For programmers, project managers, teachers and students -- both new and experienced. This book presents a set of patterns that organize all the informal experience of successful Smalltalk programmers. This book will help you understand these patterns, and empower you to write more effective code.