Abstract: A multicast data communication system is provided that has high security, and prevents problems such as an attack by a malicious user creating a great number of meaningless tables at nodes in the network. Clients regularly transmit request packets toward a server; a node receives the request packet, and subsequently receives a delivery-table-creation packet or a delivery packet from the server; if the node has no delivery table corresponding to the server, the node creates the delivery table, registers the addresses of the clients, and their request packet arrival times, and regularly transmits the request packet toward the server; when the node has received a delivery packet from the server, the node duplicates and delivers the delivery packet only to those clients whose request packet arrival times, registered in the delivery table, are within a fixed period from the arrival of the delivery packet.

Abstract: A multicast data communication system is provided that has high security, and prevents problems such as an attack by a malicious user creating a great number of meaningless tables at nodes in the network. Clients regularly transmit request packets toward a server; a node receives the request packet, and subsequently receives a delivery-table-creation packet or a delivery packet from the server; if the node has no delivery table corresponding to the server, the node creates the delivery table, registers the addresses of the clients, and their request packet arrival times, and regularly transmits the request packet toward the server; when the node has received a delivery packet from the server, the node duplicates and delivers the delivery packet only to those clients whose request packet arrival times, registered in the delivery table, are within a fixed period from the arrival of the delivery packet.

Abstract: A measurement apparatus for measuring traffic of packets with high time resolution is provided. The measurement apparatus includes an accumulation part for accumulating packet lengths of packets having predetermined header information in successively received packets, and storing an accumulated value of the packet lengths in a storage; and a periodic reading part for reading the accumulated value from the storage at predetermined time intervals, and outputting the accumulated value.

Abstract: A multicast data communication system is provided that has high security, and prevents problems such as an attack by a malicious user creating a great number of meaningless tables at nodes in the network. Clients regularly transmit request packets toward a server; a node receives the request packet, and subsequently receives a delivery-table-creation packet or a delivery packet from the server; if the node has no delivery table corresponding to the server, the node creates the delivery table, registers the addresses of the clients, and their request packet arrival times, and regularly transmits the request packet toward the server; when the node has received a delivery packet from the server, the node duplicates and delivers the delivery packet only to those clients whose request packet arrival times, registered in the delivery table, are within a fixed period from the arrival of the delivery packet.

Abstract: The acetylation level of a peptide is determined utilizing the fact that the changes in the acetylation level are reflected in the sensitivity of the substrate peptide to a peptidase. This method can be used for measuring activities of deacetylase and acetylase, and also enables screening for substances that influence the activity of these enzymes. The deacetylase activity can be measured by a simple procedure according to the present invention.

Abstract: The acetylation level of a peptide is determined utilizing the fact that the changes in the acetylation level are reflected in the sensitivity of the substrate peptide to a peptidase. This method can be used for measuring activities of deacetylase and acetylase, and also enables screening for substances that influence the activity of these enzymes. The deacetylase activity can be measured by a simple procedure according to the present invention.

Abstract: The acetylation level of a peptide is determined utilizing the fact that the changes in the acetylation level are reflected in the sensitivity of the substrate peptide to a peptidase. This method can be used for measuring activities of deacetylase and acetylase, and also enables screening for substances that influence the activity of these enzymes. The deacetylase activity can be measured by a simple procedure according to the present invention.

Abstract: A method for simply and conveniently detecting acetyltransferase and deacetylase activities of proteins by executing an acetylation reaction of a peptide substrate with an acetyltransferase, or a deacetylation reaction of an acetylated peptide substrate with a deacetylase, and after the completion of these reactions, detecting the acetyl group bound to the peptide substrate by using an anti-acetylated peptide antibody. This system for detecting acetyltransferase and deacetylase activities using the anti-acetylated peptide antibody enables screening inhibitors or enhancers of acetyltransferase and deacetylase. A system for screening deacetylase inhibitors or acetyltransferase enhancers using cultured cells is also provided.

Abstract: A method for simply and conveniently detecting acetyltransferase and deacetylase activities of proteins by executing an acetylation reaction of a peptide substrate with an acetyltransferase, or a deacetylation reaction of an acetylated peptide substrate with a deacetylase, and after the completion of these reactions, detecting the acetyl group bound to the peptide substrate by using an anti-acetylated peptide antibody. This system for detecting acetyltransferase and deacetylase activities using the anti-acetylated peptide antibody enables screening inhibitors or enhancers of acetyltransferase and deacetylase. A system for screening deacetylase inhibitors or acetyltransferase enhancers using cultured cells is also provided.

Abstract: A data selection apparatus which performs selection processes in parallel is provided. The data selection apparatus includes search units and a unit output control device. Each of the search units includes table search circuits and a data output control circuit which selects the highest priority output data. The unit output control device selects the highest priority output data from outputs of the search units. A table search circuit which succeeds in a search sends a search success signal to the data output control circuit. The search unit including the data output control circuit sends a unit search success signal to the unit output control device before performing a selection process for the highest priority data.

Abstract: A measurement apparatus for measuring traffic of packets with high time resolution is provided. The measurement apparatus includes an accumulation part for accumulating packet lengths of packets having predetermined header information in successively received packets, and storing an accumulated value of the packet lengths in a storage; and a periodic reading part for reading the accumulated value from the storage at predetermined time intervals, and outputting the accumulated value.

Abstract: The acetylation level of a peptide is determined utilizing the fact that the changes in the acetylation level are reflected in the sensitivity of the substrate peptide to a peptidase. This method can be used for measuring activities of deacetylase and acetylase, and also enables screening for substances that influence the activity of these enzymes. The deacetylase activity can be measured by a simple procedure according to the present invention.

Abstract: A multicast data communication system is provided that has high security, and prevents problems such as an attack by a malicious user creating a great number of meaningless tables at nodes in the network. Clients regularly transmit request packets toward a server; a node receives the request packet, and subsequently receives a delivery-table-creation packet or a delivery packet from the server; if the node has no delivery table corresponding to the server, the node creates the delivery table, registers the addresses of the clients, and their request packet arrival times, and regularly transmits the request packet toward the server; when the node has received a delivery packet from the server, the node duplicates and delivers the delivery packet only to those clients whose request packet arrival times, registered in the delivery table, are within a fixed period from the arrival of the delivery packet.