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Recent decades have witnessed a surge of interest in Discrete Geometry and Convex Polytopes. This book serves as a gateway to some captivating facets of this field, encompassing both well-established concepts and lesser-known, historical, and cutting-edge findings. It is crucial to note that this is not intended as an exhaustive or conventional introduction to the field. The content originated from lecture notes for a course taught at MIT, subsequently expanded upon due to the richness and relative scarcity of the material elsewhere. The presentation prioritizes self-containment to the greatest extent possible. This work should not be mistaken for a research monograph or a comprehensive survey of results. The exposition varies in complexity, aiming to balance accessibility with depth.

《Transaction Processing Concepts and Techniques》是数据库领域的经典著作，详细阐述了数据库事务处理的理论和实践。书中介绍了事务的ACID特性：原子性确保所有操作要么全部完成要么全部不完成，一致性保证事务结束后数据库状态符合业务规则，隔离性防止并发事务干扰，持久性保证事务提交后结果永久保存。此外，还讨论了事务的提交、回滚和并发控制机制，以及分布式事务处理的挑战和解决方案。适合高校学生和数据库专业人士阅读。

深入理解MySQL事务隔离级别与锁机制是数据库系统中非常重要的概念，解决多事务并发问题。事务是一个逻辑处理单元，具备原子性、一致性、隔离性和持久性四个ACID属性。并发处理可能引发更新丢失、脏读、不可重复读和幻读等问题，这需要通过事务隔离机制和锁机制来解决。MySQL的常见隔离级别包括Read Uncommitted、Read Committed、Repeatable Read和Serializable。锁机制分为乐观锁和悲观锁，后者又可分为读锁和写锁，根据不同场景选择合适的隔离级别和锁机制至关重要，以提高并发性能和数据一致性。

使用离散Hopfield神经网络对模糊数字进行识别，并给出识别结果。可以调节数字的模糊程度，以检验识别效果。

The Discrete Time Signal Processing 2nd Edition focuses on the fundamental concepts of Discrete-Time Signal Processing and digital signal processing. This edition covers advanced topics like filter design, Fourier analysis, and sampling theory. Key algorithms for signal manipulation and transformations are explained in-depth, providing insights into both theoretical and practical aspects of signal processing.

BEGIN-END语句在T-SQL中用于创建一个语句块，将多条T-SQL语句组合在一起执行。 语句块在执行时被视为单个语句，常用于条件语句（如IF-ELSE）和循环语句（如WHILE）中。

MySQL存储过程可以通过BEGIN...END复合语句包含多条语句，每条语句以分号结尾。复合语句允许标记，提供灵活的程序结构。在命令行客户端中，可以使用delimiter命令修改语句定界符，例如将分号改为//，以便在子程序体中使用分号。

2．BEGIN...END语句tBEGIN...END语句允许将多个Transact-SQL语句组合成一个语句块，作为一个单元进行处理。在条件语句和循环等控制流程中，当需要根据特定条件执行两个或多个语句时，需采用BEGIN...END语句。其语法格式为： tBEGIN { sql_statement | statement_block } END