We examine a new class of channel coding strategies, and hypothesis tests referred to as almost-fixed-length strategies that have little flexibility in the stopping time over fixed-length strategies. The stopping time of these strategies is allowed to be slightly large only on a rare set of sample paths with an exponentially small probability. We show that almost-fixed-length channel coding strategies can achieve Burnashev's optimal error exponent. Similarly, almost-fixed length hypothesis tests are shown to bridge the gap between hypothesis testing with fixed sample size and sequential hypothesis testing and improve the trade-off between type-I and type-II error exponents.

翻译：我们考察了新型的频道编码策略,以及被称为几乎固定长程战略的假想测试,这些假想测试在固定长程战略的停顿时间上几乎没有灵活性。这些策略的停顿时间仅允许在极小的概率极小的稀有样本路径上略微大一些。我们发现,几乎固定长程的频道编码策略可以达到伯纳舍夫的最佳误差。 同样,几乎固定长长的假想测试也证明可以弥合使用固定样本大小的假设测试与顺序假设测试之间的差距,并改进类型一和类型二误差指数之间的权衡。