Besides, diverse postures, circumstances, viewpoints, positions, etc. may usually cause non-negligible interference for recognition, which further increase the difficulty.
Compared to influenza and RSV, these two viruses exhibit less clearly defined seasonal variations, which may further increase the difficulty in relating the variation of hospitalizations to the weekly proportions of parainfluenza and adenovirus.
The process of evolution contains a series of unknown demographic events, including population bottleneck, admixture of populations, migration, inbreeding and genetic drift, which further increase the difficulty of detecting selection signatures.
Poor glycemic control, the presence of risk factors for complications (hypertension and dyslipidemia), high-risk behaviors (cigarette smoking and drug and/or alcohol abuse), and emerging complications may further increase the difficulty of this period.
The additive background noise further increases the difficulty for accurately estimating the AIR.
Moreover, for indoor applications, the room acoustics further increases the difficulty.
Meanwhile, the frequency-selective channel requires very sophisticated equalizers, which further increases the difficulty in fitting the legacy QAM waveform into today's communication systems.
Different from MaF14, this test problem has non-linear (instead of linear) variable linkages on the PS, which further increases the difficulty.
In addition, the characteristics of acetone as a strong solvent which can easily swell and dissolve polymer materials, further increases the difficulty of separation.
