The phrase "a key problem to" is not correct in standard written English.
It is typically used when discussing significant issues or challenges that need to be addressed, but the preposition "to" is not appropriate in this context.
Example: "A key problem to consider is the lack of funding for the project."
Alternatives: "a key problem with" or "a key issue regarding".
Thermal effect is a key problem to obtain high average power output from the Fe:ZnSe crystal.
An automatic way to determine the distance threshold of RANSAC is proposed, which is a key problem to implement this RANSAC-based automatic optimization.
Finding optimal operating conditions fast with a scarce budget of experimental runs is a key problem to speed up the development and scaling up of innovative bioprocesses.
In heterogeneous networks, it is a key problem to obtain the optimal mining results from the diversity of data.
The device side energy efficiency is a key problem to make 3GPP cellular networks as a competitive solution for MTC.
It is a key problem to complete the mapping from the solution space of optimization problem to the coding space.
There is a key problem as to how to obtain a robust video foreground reconstruction result using the compressed measurement.
As mentioned in the introduction, a key problem is to stop requiring line managers to understand the details of the many different types of graphs and charts, to not have then think like analysts.
A key problem appears to be the cost of shifting pension funds for the observatories' staff to a private body.
Tube thinning control without wrinkling occurring is a key problem urgently to be solved for improving the forming qualities in numerical control (NC) bending processes of large-diameter Al-alloy thin-walled tubes (AATTs).
A key problem seemed to be that Rittman's kettle didn't come with software that would easily allow integration with other devices in his home, including Amazon Echo, which, like Apple's Siri, allows users to tell connected smart devices what to do.
