In the context of open science, the management of metadata is essential for promoting research data utilization. Experimental scientists are required to manage a substantial volume of experimental data, including a significant proportion of failed data. This places a considerable burden on the experimental scientists. In this paper, we outline the development of a conceptual image for a data aggregation and management infrastructure for core facilities. The infrastructure enables an automatic assignment of unique identifier and metadata, optimizing research data management of experimental scientists.

A bio-nanomachine network is useful in diverse applications of molecular communication. In this paper, we develop a network formation model of bio-nanomachines based on how vascular endothelial cells form a blood vessel-like structure. In our model, bio-nanomachines migrate toward each other using attractant molecules. When two bio-nanomachines move close to each other, they adhere to form a physical connection or a link between them. In this way, a group of bio-nanomachines forms a network collectively. We perform computer simulations using the model to identify critical parameter values at which a large-scale bio-nanomachine network emerges. The model developed in this paper helps us design synthetic communication networks of bio-nanomachines.

Geographical contour lines are often used for the analysis of the sensor data distribution on wide area. In this paper, we propose a method to reconstruct contour lines by collecting sensor data from widely distributed sensors. In this case, it is redundant to collect all sensors from wide area since geographically closed sensors sense similar data. We propose a sensor data collection method for peer-to-peer sensor network to realize spatial interpolation of sensor data. In our proposal, we assume hierarchical Delaunay overlay network (HDOV) to collect sensor data uniformly. In addition, using structure of HDOV, more local sensor data is collected that affect on the spatial interpolation. By this mechanism, redundant sensor data to reconstruct geographical contour lines is reduced. The simulation result shows that our proposal can reconstruct accurate geographical contour lines, reducing target node and message numbers for data collection.

This article presents a Web content adaptation and delivery mechanism based on application-level quality of service (QoS) policies. To realize effective Web content delivery for users, two kinds of application-level QoS policies, transmission time and transmission order of inline objects, are introduced. Next, we define a language to specify these policies. We show that transmission order control can be implemented using HTTP/1.1 pipelined requests in which a client recognizes the transmission order description in a Web page and simulates parallel transmission of inline objects by HTTP/1.1 range requests. Experimental results show that our proposed mechanism realizes effective content delivery to a diverse group of Internet users. Finally, we introduce two methods to specify application-level QoS policies, one by content authors, and the other by end users.

Dynamic relocation of databases through networks, or database migration, will soon become a powerful standard database operation effectively using recent advances in broadband networks. In our previous work, a transaction processing method has been proposed in distributed database environments, based on database migration operations. Generally, database replication is an effective technique to improve transaction processing throughput in conventional systems. We propose a replica management method for use with database migration. Database migration is used at the beginning of a transaction to dynamically relocate database replicas. The performance of the proposed method is evaluated using simulation results.

Because of the recent development of network technologies such as ATM (Asynchronous Transfer Mode), broader channel bandwidth is becoming available everywhere in the world wide networks. As one of the new technologies to make good use of such broadband channel, dynamic relocation of databases through networks, which we call database migration, will soon become a powerful and basic database operation of practical use. We discuss our proposal of a distributed database system, DB-MAN (distributed database system based on DataBase Migration in ATM Networks), which takes advantage of database migration in virtual LANs (local area networks) of ATM networks. DB-MAN has two notable mechanisms: a mechanism for selecting the transaction processing method and a mechanism for concurrency control with database migration. The former, is a mechanism which chooses the more efficient method between two transaction processing methods: the conventional method based on the two phase commit protocol and our method employing database migration. The latter is a mechanism to prevent the transaction processing throughput from deteriorating in environments where data contention is a significant factor. Then we show simulation results regarding performance comparison between our proposed system and the conventional distributed database system based on the two phase commit protocol. The obtained results demonstrate that effective use of database migration gives higher performance than that of the conventional system.

Due to recent developments in network technologies, broader channel bandwidth is becoming prevalent in worldwide networks. As one of the new technologies making good use of such broadband channels, dynamic relocation of databases through networks, database migration, will soon be used in practice as a powerful and basic database operation. We propose two transaction processing methods to take advantage of database migration in broadband networks. These methods choose the most efficient transaction processing method between the conventional method, based on the two-phase commit protocol, and our method, using database migration. We also propose a concurrency control mechanism and a recovery mechanism for our proposed methods. Simulation results are presented comparing the performance of our proposed methods and the conventional transaction processing method based on the two-phase commit protocol. The results demonstrate that the effective use of database migration produces better performance than the conventional method.