U.S. Sgt. NAME_1, acting as OPFOR, instructs notional POWs on how to use the Arctic space heater in support of Joint Pacific Multinational Readiness Center-Alaska 23-02 at Yukon Training Area, Alaska, March 30, 2023. JPMRC-AK 23-02 helps Soldiers and leaders develop and refine the tactics, techniques, and procedures necessary to successfully operate in remote and extreme Arctic winter......
Extract the following items only from this news:
    - personal name
    - rank
    - hometown
    Format your response as JSON object with "name" , "rank" and "hometown" as the keys.
    If the information isn't present, use "unknown" as the value.
    Make your response as short as possible. I want the entire output in JSON format.
user