By Lawrence Matheson Amazon has welcomed Andrew Ng, a prominent figure in the field of artificial intelligence (AI), to its board of directors. The move comes as AI competition heats up among startups and major tech firms. The Seattle-based company announced on Thursday that Ng, who is currently a managing director at the Palo Alto, California-based AI Fund, will fill the seat left vacant by Judy McGrath, former chief executive of MTV, who has decided not to stand for re-election. Ng’s AI Fund, established in 2017, invests in entrepreneurs who are building AI companies. He previously led AI te…