A Western Global Airlines McDonnell Douglas MD-11, registration N415JN performing flight KD-1576 from Anchorage,AK to Louisville,KY (USA), was enroute at FL330 about 100nm south of Chicago,IL (USA) and about 180nm northwest of Louisville when the crew descended the aircraft to FL290, subsequently declared emergency and initiated an emergency descent to 10,000 feet due to the loss of cabin pressure. The aircraft continued to Louisville maintaining 10,000 feet for about 10 minutes, on approach to Lousiville advised no assistance was needed, landed safely on Louisville's runway 17R maintaining routine communication with tower about 30 minutes after leaving FL330 and taxied to the apron.