convert big5 hex codepoint to utf-8 string

gistfile1.rb

require 'iconv'
$KCODE = 'u'

hex_string ="4A6BA441" # A441 is big5 "乙"
big5_string = hex_string.scan(/../).map{ |c| c.hex }.pack("c*")
iconv = Iconv.new("utf-8//ignore", "big5")
utf8_string = iconv.iconv(big5_string) # convert to utf-8

puts utf8_string # output JK乙