Takayuki Tachikawa

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In distributed applications, a group of application processes is established and the processes in the group communicate with one another, i.e. intra-group communication. Here, messages have to be reliably and causally delivered to all the destinations. In addition, the processes send messages to any subset of the group at any time. This paper presents an(More)
In distributed applications, a group of multiple objects are cooperating to achieve some objectives by exchanging messages through communication networks. An object is modeled as a pair of data structure and operations. In the cooperation among multiple objects, it is important to protect against illegal information ow among the objects. In this paper, we(More)
In distributed applications, a group of multiple objects are cooperating to achieve some objectives. An object is modeled as a pair of data structure and operations. Each object is manipulated through an operation supported by the object and then the operation may further invoke operations of other objects, i.e. nested operations. The purpose-oriented(More)
This paper proposes a novel algorithm for taking checkpoints and rolling back the processes for recovery in asynchronous distributed systems. The algorithm has the following properties: (1) Multiple processes can simultaneously initiate the checkpointing. (2) No additional message is transmitted for taking checkpoints. (3) A set of local checkpoints taken(More)
In distributed applications, a group of multiple processes is required to be cooperated by exchanging mul-timedia data. In addition, worldwide distributed applications are being realized by using the Internet. The traditional group communication protocols assume that every pair of processes support the same and xed delay time and reliability level. In(More)