
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given the function $f(x)=\frac{kx^{2}}{e^{x}}$ $(k > 0)$.

$(1)$ Find the intervals of monotonicity for the function $f(x)$;

$(2)$ When $k=1$, if there exists $x > 0$ such that $\ln f(x) > ax$ holds, find the range of the real number $a$.

Present the answer in LaTex format: \boxed{Your answer}
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