MIDI controllers that only have a USB interface need a USB host (e.g. computer with DAW software) to be used. Even though MIDI over USB is possible, it's not a standard that allows for the use of a simple USB-to-MIDI Interface. The USB-to-MIDI interfaces themselves require a host computer just the same.
It is possible to purchase a box that acts as a USB host, such as the CAMOLA USB MIDI Host Box USB to MIDI Converter MIDI Interface ($50). But honestly at that price, you might be better off purchasing a MIDI controller keyboard that has built-in MIDI DIN ports, such as the Behringer Swing 32.
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You could use your MIDI controller keyboard with your computer, and route the MIDI in your DAW to go out of a USB-to-MIDI interface (such as the CME U2MIDI) that is connected to the QY100. But you're not going to be able to hear the instrumentation of the QY100 respond to that unless you connect a 5mm TRS cable from the "Line Out/Phones" jack of your QY100 into an audio interface connected to your computer and configure your DAW to monitor that audio while the USB is being sent to the QY100.
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Overall, what are you trying to do with the QY100? Are you trying to use it as a sound module? It does have an amazing library of sounds.
Jason Miller