Abstract: The present invention provides a system which maintains a function of monitoring and controlling a network regardless of an increase of data to be downloaded by a computer whose access to the network is restricted.

Abstract: The method is that of detecting a network address translation device which transfers network data to a first device. This method includes: obtaining an address of a second device connected to the network; generating pseudo network data in which an address is set as a destination address, and in which a number of times that the network data can be transferred is set as a number of transfers required to reach the first device; transmitting the pseudo network data to the second device; detecting a message from the second device, the message indicating that the pseudo network data cannot be further transferred; and determining that the second device is operating the network address translation device in response to the detection of the message.

Abstract: The present invention provides a polypeptide selected from a polypeptide of subunit (A) or a polypeptide of subunit (B) of a prenyl diphosphate synthetase; a DNA coding for the polypeptide; a recombinant vector comprising the DNA; a transformant transformed with the vector; and a method for preparing an active type prenyl diphosphate synthetase. Also disclosed is a method for preparing an active type enzyme on which a specific property has been conferred, comprising mixing polypeptides of the two subunits of a heterodimeric enzyme, the polypeptides being derived from different organisms and one of the polypeptides having the specific property.

Abstract: The present invention provides a polypeptide selected from a polypeptide of subunit (A) or a polypeptide of subunit (B) of a prenyl diphosphate synthetase; a DNA coding for the polypeptide; a recombinant vector comprising the DNA; a transformant transformed with the vector; and a method for preparing an active type prenyl diphosphate synthetase. Also disclosed is a method for preparing an active type enzyme on which a specific property has been conferred, comprising mixing polypeptides of the two subunits of a heterodimeric enzyme, the polypeptides being derived from different organisms and one of the polypeptides having the specific property.